diff --git a/fs/btrfs/Kconfig b/fs/btrfs/Kconfig
index 23537bc..38651fa 100644
--- a/fs/btrfs/Kconfig
+++ b/fs/btrfs/Kconfig
@@ -2,6 +2,8 @@
 
 config BTRFS_FS
 	tristate "Btrfs filesystem support"
+	select CRYPTO
+	select CRYPTO_CRC32C
 	select LIBCRC32C
 	select ZLIB_INFLATE
 	select ZLIB_DEFLATE
diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
index ca693dd..82200db 100644
--- a/fs/btrfs/Makefile
+++ b/fs/btrfs/Makefile
@@ -10,7 +10,8 @@
 	   export.o tree-log.o free-space-cache.o zlib.o lzo.o zstd.o \
 	   compression.o delayed-ref.o relocation.o delayed-inode.o scrub.o \
 	   reada.o backref.o ulist.o qgroup.o send.o dev-replace.o raid56.o \
-	   uuid-tree.o props.o free-space-tree.o tree-checker.o
+	   uuid-tree.o props.o free-space-tree.o tree-checker.o space-info.o \
+	   block-rsv.o delalloc-space.o block-group.o
 
 btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o
 btrfs-$(CONFIG_BTRFS_FS_CHECK_INTEGRITY) += check-integrity.o
diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c
index 3b66c95..a0af1b9 100644
--- a/fs/btrfs/acl.c
+++ b/fs/btrfs/acl.c
@@ -9,6 +9,7 @@
 #include <linux/posix_acl_xattr.h>
 #include <linux/posix_acl.h>
 #include <linux/sched.h>
+#include <linux/sched/mm.h>
 #include <linux/slab.h>
 
 #include "ctree.h"
@@ -72,8 +73,16 @@
 	}
 
 	if (acl) {
+		unsigned int nofs_flag;
+
 		size = posix_acl_xattr_size(acl->a_count);
+		/*
+		 * We're holding a transaction handle, so use a NOFS memory
+		 * allocation context to avoid deadlock if reclaim happens.
+		 */
+		nofs_flag = memalloc_nofs_save();
 		value = kmalloc(size, GFP_KERNEL);
+		memalloc_nofs_restore(nofs_flag);
 		if (!value) {
 			ret = -ENOMEM;
 			goto out;
@@ -84,7 +93,11 @@
 			goto out;
 	}
 
-	ret = btrfs_setxattr(trans, inode, name, value, size, 0);
+	if (trans)
+		ret = btrfs_setxattr(trans, inode, name, value, size, 0);
+	else
+		ret = btrfs_setxattr_trans(inode, name, value, size, 0);
+
 out:
 	kfree(value);
 
diff --git a/fs/btrfs/async-thread.c b/fs/btrfs/async-thread.c
index d522494..2e9e13f 100644
--- a/fs/btrfs/async-thread.c
+++ b/fs/btrfs/async-thread.c
@@ -12,9 +12,11 @@
 #include "async-thread.h"
 #include "ctree.h"
 
-#define WORK_DONE_BIT 0
-#define WORK_ORDER_DONE_BIT 1
-#define WORK_HIGH_PRIO_BIT 2
+enum {
+	WORK_DONE_BIT,
+	WORK_ORDER_DONE_BIT,
+	WORK_HIGH_PRIO_BIT,
+};
 
 #define NO_THRESHOLD (-1)
 #define DFT_THRESHOLD (32)
@@ -139,13 +141,11 @@
 	}
 
 	if (flags & WQ_HIGHPRI)
-		ret->normal_wq = alloc_workqueue("%s-%s-high", flags,
-						 ret->current_active, "btrfs",
-						 name);
+		ret->normal_wq = alloc_workqueue("btrfs-%s-high", flags,
+						 ret->current_active, name);
 	else
-		ret->normal_wq = alloc_workqueue("%s-%s", flags,
-						 ret->current_active, "btrfs",
-						 name);
+		ret->normal_wq = alloc_workqueue("btrfs-%s", flags,
+						 ret->current_active, name);
 	if (!ret->normal_wq) {
 		kfree(ret);
 		return NULL;
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index ae750b1..e5d8531 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -112,11 +112,11 @@
 }
 
 struct preftree {
-	struct rb_root root;
+	struct rb_root_cached root;
 	unsigned int count;
 };
 
-#define PREFTREE_INIT	{ .root = RB_ROOT, .count = 0 }
+#define PREFTREE_INIT	{ .root = RB_ROOT_CACHED, .count = 0 }
 
 struct preftrees {
 	struct preftree direct;    /* BTRFS_SHARED_[DATA|BLOCK]_REF_KEY */
@@ -225,14 +225,15 @@
 			      struct prelim_ref *newref,
 			      struct share_check *sc)
 {
-	struct rb_root *root;
+	struct rb_root_cached *root;
 	struct rb_node **p;
 	struct rb_node *parent = NULL;
 	struct prelim_ref *ref;
 	int result;
+	bool leftmost = true;
 
 	root = &preftree->root;
-	p = &root->rb_node;
+	p = &root->rb_root.rb_node;
 
 	while (*p) {
 		parent = *p;
@@ -242,6 +243,7 @@
 			p = &(*p)->rb_left;
 		} else if (result > 0) {
 			p = &(*p)->rb_right;
+			leftmost = false;
 		} else {
 			/* Identical refs, merge them and free @newref */
 			struct extent_inode_elem *eie = ref->inode_list;
@@ -272,7 +274,7 @@
 	preftree->count++;
 	trace_btrfs_prelim_ref_insert(fs_info, newref, NULL, preftree->count);
 	rb_link_node(&newref->rbnode, parent, p);
-	rb_insert_color(&newref->rbnode, root);
+	rb_insert_color_cached(&newref->rbnode, root, leftmost);
 }
 
 /*
@@ -283,11 +285,11 @@
 {
 	struct prelim_ref *ref, *next_ref;
 
-	rbtree_postorder_for_each_entry_safe(ref, next_ref, &preftree->root,
-					     rbnode)
+	rbtree_postorder_for_each_entry_safe(ref, next_ref,
+					     &preftree->root.rb_root, rbnode)
 		free_pref(ref);
 
-	preftree->root = RB_ROOT;
+	preftree->root = RB_ROOT_CACHED;
 	preftree->count = 0;
 }
 
@@ -589,7 +591,7 @@
 }
 
 /*
- * We maintain three seperate rbtrees: one for direct refs, one for
+ * We maintain three separate rbtrees: one for direct refs, one for
  * indirect refs which have a key, and one for indirect refs which do not
  * have a key. Each tree does merge on insertion.
  *
@@ -627,7 +629,7 @@
 	 * freeing the entire indirect tree when we're done.  In some test
 	 * cases, the tree can grow quite large (~200k objects).
 	 */
-	while ((rnode = rb_first(&preftrees->indirect.root))) {
+	while ((rnode = rb_first_cached(&preftrees->indirect.root))) {
 		struct prelim_ref *ref;
 
 		ref = rb_entry(rnode, struct prelim_ref, rbnode);
@@ -637,7 +639,7 @@
 			goto out;
 		}
 
-		rb_erase(&ref->rbnode, &preftrees->indirect.root);
+		rb_erase_cached(&ref->rbnode, &preftrees->indirect.root);
 		preftrees->indirect.count--;
 
 		if (ref->count == 0) {
@@ -693,7 +695,7 @@
 		}
 
 		/*
-		 * Now it's a direct ref, put it in the the direct tree. We must
+		 * Now it's a direct ref, put it in the direct tree. We must
 		 * do this last because the ref could be merged/freed here.
 		 */
 		prelim_ref_insert(fs_info, &preftrees->direct, ref, NULL);
@@ -710,16 +712,16 @@
  * read tree blocks and add keys where required.
  */
 static int add_missing_keys(struct btrfs_fs_info *fs_info,
-			    struct preftrees *preftrees)
+			    struct preftrees *preftrees, bool lock)
 {
 	struct prelim_ref *ref;
 	struct extent_buffer *eb;
 	struct preftree *tree = &preftrees->indirect_missing_keys;
 	struct rb_node *node;
 
-	while ((node = rb_first(&tree->root))) {
+	while ((node = rb_first_cached(&tree->root))) {
 		ref = rb_entry(node, struct prelim_ref, rbnode);
-		rb_erase(node, &tree->root);
+		rb_erase_cached(node, &tree->root);
 
 		BUG_ON(ref->parent);	/* should not be a direct ref */
 		BUG_ON(ref->key_for_search.type);
@@ -735,12 +737,14 @@
 			free_extent_buffer(eb);
 			return -EIO;
 		}
-		btrfs_tree_read_lock(eb);
+		if (lock)
+			btrfs_tree_read_lock(eb);
 		if (btrfs_header_level(eb) == 0)
 			btrfs_item_key_to_cpu(eb, &ref->key_for_search, 0);
 		else
 			btrfs_node_key_to_cpu(eb, &ref->key_for_search, 0);
-		btrfs_tree_read_unlock(eb);
+		if (lock)
+			btrfs_tree_read_unlock(eb);
 		free_extent_buffer(eb);
 		prelim_ref_insert(fs_info, &preftrees->indirect, ref, NULL);
 		cond_resched();
@@ -769,7 +773,7 @@
 		btrfs_disk_key_to_cpu(&tmp_op_key, &extent_op->key);
 
 	spin_lock(&head->lock);
-	for (n = rb_first(&head->ref_tree); n; n = rb_next(n)) {
+	for (n = rb_first_cached(&head->ref_tree); n; n = rb_next(n)) {
 		node = rb_entry(n, struct btrfs_delayed_ref_node,
 				ref_node);
 		if (node->seq > seq)
@@ -787,7 +791,7 @@
 			count = node->ref_mod * -1;
 			break;
 		default:
-			BUG_ON(1);
+			BUG();
 		}
 		*total_refs += count;
 		switch (node->type) {
@@ -1225,18 +1229,18 @@
 
 	btrfs_release_path(path);
 
-	ret = add_missing_keys(fs_info, &preftrees);
+	ret = add_missing_keys(fs_info, &preftrees, path->skip_locking == 0);
 	if (ret)
 		goto out;
 
-	WARN_ON(!RB_EMPTY_ROOT(&preftrees.indirect_missing_keys.root));
+	WARN_ON(!RB_EMPTY_ROOT(&preftrees.indirect_missing_keys.root.rb_root));
 
 	ret = resolve_indirect_refs(fs_info, path, time_seq, &preftrees,
 				    extent_item_pos, total_refs, sc, ignore_offset);
 	if (ret)
 		goto out;
 
-	WARN_ON(!RB_EMPTY_ROOT(&preftrees.indirect.root));
+	WARN_ON(!RB_EMPTY_ROOT(&preftrees.indirect.root.rb_root));
 
 	/*
 	 * This walks the tree of merged and resolved refs. Tree blocks are
@@ -1245,7 +1249,7 @@
 	 *
 	 * We release the entire tree in one go before returning.
 	 */
-	node = rb_first(&preftrees.direct.root);
+	node = rb_first_cached(&preftrees.direct.root);
 	while (node) {
 		ref = rb_entry(node, struct prelim_ref, rbnode);
 		node = rb_next(&ref->rbnode);
@@ -1286,11 +1290,15 @@
 					ret = -EIO;
 					goto out;
 				}
-				btrfs_tree_read_lock(eb);
-				btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
+
+				if (!path->skip_locking) {
+					btrfs_tree_read_lock(eb);
+					btrfs_set_lock_blocking_read(eb);
+				}
 				ret = find_extent_in_eb(eb, bytenr,
 							*extent_item_pos, &eie, ignore_offset);
-				btrfs_tree_read_unlock_blocking(eb);
+				if (!path->skip_locking)
+					btrfs_tree_read_unlock_blocking(eb);
 				free_extent_buffer(eb);
 				if (ret < 0)
 					goto out;
@@ -1452,37 +1460,35 @@
  * callers (such as fiemap) which want to know whether the extent is
  * shared but do not need a ref count.
  *
- * This attempts to allocate a transaction in order to account for
- * delayed refs, but continues on even when the alloc fails.
+ * This attempts to attach to the running transaction in order to account for
+ * delayed refs, but continues on even when no running transaction exists.
  *
  * Return: 0 if extent is not shared, 1 if it is shared, < 0 on error.
  */
-int btrfs_check_shared(struct btrfs_root *root, u64 inum, u64 bytenr)
+int btrfs_check_shared(struct btrfs_root *root, u64 inum, u64 bytenr,
+		struct ulist *roots, struct ulist *tmp)
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_trans_handle *trans;
-	struct ulist *tmp = NULL;
-	struct ulist *roots = NULL;
 	struct ulist_iterator uiter;
 	struct ulist_node *node;
 	struct seq_list elem = SEQ_LIST_INIT(elem);
 	int ret = 0;
 	struct share_check shared = {
-		.root_objectid = root->objectid,
+		.root_objectid = root->root_key.objectid,
 		.inum = inum,
 		.share_count = 0,
 	};
 
-	tmp = ulist_alloc(GFP_NOFS);
-	roots = ulist_alloc(GFP_NOFS);
-	if (!tmp || !roots) {
-		ulist_free(tmp);
-		ulist_free(roots);
-		return -ENOMEM;
-	}
+	ulist_init(roots);
+	ulist_init(tmp);
 
-	trans = btrfs_join_transaction(root);
+	trans = btrfs_join_transaction_nostart(root);
 	if (IS_ERR(trans)) {
+		if (PTR_ERR(trans) != -ENOENT && PTR_ERR(trans) != -EROFS) {
+			ret = PTR_ERR(trans);
+			goto out;
+		}
 		trans = NULL;
 		down_read(&fs_info->commit_root_sem);
 	} else {
@@ -1515,8 +1521,9 @@
 	} else {
 		up_read(&fs_info->commit_root_sem);
 	}
-	ulist_free(tmp);
-	ulist_free(roots);
+out:
+	ulist_release(roots);
+	ulist_release(tmp);
 	return ret;
 }
 
@@ -1648,7 +1655,7 @@
 		/* make sure we can use eb after releasing the path */
 		if (eb != eb_in) {
 			if (!path->skip_locking)
-				btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
+				btrfs_set_lock_blocking_read(eb);
 			path->nodes[0] = NULL;
 			path->locks[0] = 0;
 		}
@@ -1739,7 +1746,7 @@
 		else if (flags & BTRFS_EXTENT_FLAG_DATA)
 			*flags_ret = BTRFS_EXTENT_FLAG_DATA;
 		else
-			BUG_ON(1);
+			BUG();
 		return 0;
 	}
 
@@ -1904,14 +1911,20 @@
 			extent_item_objectid);
 
 	if (!search_commit_root) {
-		trans = btrfs_join_transaction(fs_info->extent_root);
-		if (IS_ERR(trans))
-			return PTR_ERR(trans);
-		btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem);
-	} else {
-		down_read(&fs_info->commit_root_sem);
+		trans = btrfs_attach_transaction(fs_info->extent_root);
+		if (IS_ERR(trans)) {
+			if (PTR_ERR(trans) != -ENOENT &&
+			    PTR_ERR(trans) != -EROFS)
+				return PTR_ERR(trans);
+			trans = NULL;
+		}
 	}
 
+	if (trans)
+		btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem);
+	else
+		down_read(&fs_info->commit_root_sem);
+
 	ret = btrfs_find_all_leafs(trans, fs_info, extent_item_objectid,
 				   tree_mod_seq_elem.seq, &refs,
 				   &extent_item_pos, ignore_offset);
@@ -1943,7 +1956,7 @@
 
 	free_leaf_list(refs);
 out:
-	if (!search_commit_root) {
+	if (trans) {
 		btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem);
 		btrfs_end_transaction(trans);
 	} else {
@@ -2018,9 +2031,6 @@
 			ret = -ENOMEM;
 			break;
 		}
-		extent_buffer_get(eb);
-		btrfs_tree_read_lock(eb);
-		btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
 		btrfs_release_path(path);
 
 		item = btrfs_item_nr(slot);
@@ -2031,7 +2041,8 @@
 			/* path must be released before calling iterate()! */
 			btrfs_debug(fs_root->fs_info,
 				"following ref at offset %u for inode %llu in tree %llu",
-				cur, found_key.objectid, fs_root->objectid);
+				cur, found_key.objectid,
+				fs_root->root_key.objectid);
 			ret = iterate(parent, name_len,
 				      (unsigned long)(iref + 1), eb, ctx);
 			if (ret)
@@ -2039,7 +2050,6 @@
 			len = sizeof(*iref) + name_len;
 			iref = (struct btrfs_inode_ref *)((char *)iref + len);
 		}
-		btrfs_tree_read_unlock_blocking(eb);
 		free_extent_buffer(eb);
 	}
 
@@ -2080,10 +2090,6 @@
 			ret = -ENOMEM;
 			break;
 		}
-		extent_buffer_get(eb);
-
-		btrfs_tree_read_lock(eb);
-		btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
 		btrfs_release_path(path);
 
 		item_size = btrfs_item_size_nr(eb, slot);
@@ -2104,7 +2110,6 @@
 			cur_offset += btrfs_inode_extref_name_len(eb, extref);
 			cur_offset += sizeof(*extref);
 		}
-		btrfs_tree_read_unlock_blocking(eb);
 		free_extent_buffer(eb);
 
 		offset++;
diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h
index 54d5898..777f61d 100644
--- a/fs/btrfs/backref.h
+++ b/fs/btrfs/backref.h
@@ -57,7 +57,8 @@
 			  u64 start_off, struct btrfs_path *path,
 			  struct btrfs_inode_extref **ret_extref,
 			  u64 *found_off);
-int btrfs_check_shared(struct btrfs_root *root, u64 inum, u64 bytenr);
+int btrfs_check_shared(struct btrfs_root *root, u64 inum, u64 bytenr,
+		struct ulist *roots, struct ulist *tmp_ulist);
 
 int __init btrfs_prelim_ref_init(void);
 void __cold btrfs_prelim_ref_exit(void);
diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
new file mode 100644
index 0000000..670700c
--- /dev/null
+++ b/fs/btrfs/block-group.c
@@ -0,0 +1,3174 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "misc.h"
+#include "ctree.h"
+#include "block-group.h"
+#include "space-info.h"
+#include "disk-io.h"
+#include "free-space-cache.h"
+#include "free-space-tree.h"
+#include "disk-io.h"
+#include "volumes.h"
+#include "transaction.h"
+#include "ref-verify.h"
+#include "sysfs.h"
+#include "tree-log.h"
+#include "delalloc-space.h"
+
+/*
+ * Return target flags in extended format or 0 if restripe for this chunk_type
+ * is not in progress
+ *
+ * Should be called with balance_lock held
+ */
+static u64 get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags)
+{
+	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
+	u64 target = 0;
+
+	if (!bctl)
+		return 0;
+
+	if (flags & BTRFS_BLOCK_GROUP_DATA &&
+	    bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) {
+		target = BTRFS_BLOCK_GROUP_DATA | bctl->data.target;
+	} else if (flags & BTRFS_BLOCK_GROUP_SYSTEM &&
+		   bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
+		target = BTRFS_BLOCK_GROUP_SYSTEM | bctl->sys.target;
+	} else if (flags & BTRFS_BLOCK_GROUP_METADATA &&
+		   bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) {
+		target = BTRFS_BLOCK_GROUP_METADATA | bctl->meta.target;
+	}
+
+	return target;
+}
+
+/*
+ * @flags: available profiles in extended format (see ctree.h)
+ *
+ * Return reduced profile in chunk format.  If profile changing is in progress
+ * (either running or paused) picks the target profile (if it's already
+ * available), otherwise falls back to plain reducing.
+ */
+static u64 btrfs_reduce_alloc_profile(struct btrfs_fs_info *fs_info, u64 flags)
+{
+	u64 num_devices = fs_info->fs_devices->rw_devices;
+	u64 target;
+	u64 raid_type;
+	u64 allowed = 0;
+
+	/*
+	 * See if restripe for this chunk_type is in progress, if so try to
+	 * reduce to the target profile
+	 */
+	spin_lock(&fs_info->balance_lock);
+	target = get_restripe_target(fs_info, flags);
+	if (target) {
+		/* Pick target profile only if it's already available */
+		if ((flags & target) & BTRFS_EXTENDED_PROFILE_MASK) {
+			spin_unlock(&fs_info->balance_lock);
+			return extended_to_chunk(target);
+		}
+	}
+	spin_unlock(&fs_info->balance_lock);
+
+	/* First, mask out the RAID levels which aren't possible */
+	for (raid_type = 0; raid_type < BTRFS_NR_RAID_TYPES; raid_type++) {
+		if (num_devices >= btrfs_raid_array[raid_type].devs_min)
+			allowed |= btrfs_raid_array[raid_type].bg_flag;
+	}
+	allowed &= flags;
+
+	if (allowed & BTRFS_BLOCK_GROUP_RAID6)
+		allowed = BTRFS_BLOCK_GROUP_RAID6;
+	else if (allowed & BTRFS_BLOCK_GROUP_RAID5)
+		allowed = BTRFS_BLOCK_GROUP_RAID5;
+	else if (allowed & BTRFS_BLOCK_GROUP_RAID10)
+		allowed = BTRFS_BLOCK_GROUP_RAID10;
+	else if (allowed & BTRFS_BLOCK_GROUP_RAID1)
+		allowed = BTRFS_BLOCK_GROUP_RAID1;
+	else if (allowed & BTRFS_BLOCK_GROUP_RAID0)
+		allowed = BTRFS_BLOCK_GROUP_RAID0;
+
+	flags &= ~BTRFS_BLOCK_GROUP_PROFILE_MASK;
+
+	return extended_to_chunk(flags | allowed);
+}
+
+static u64 get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags)
+{
+	unsigned seq;
+	u64 flags;
+
+	do {
+		flags = orig_flags;
+		seq = read_seqbegin(&fs_info->profiles_lock);
+
+		if (flags & BTRFS_BLOCK_GROUP_DATA)
+			flags |= fs_info->avail_data_alloc_bits;
+		else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
+			flags |= fs_info->avail_system_alloc_bits;
+		else if (flags & BTRFS_BLOCK_GROUP_METADATA)
+			flags |= fs_info->avail_metadata_alloc_bits;
+	} while (read_seqretry(&fs_info->profiles_lock, seq));
+
+	return btrfs_reduce_alloc_profile(fs_info, flags);
+}
+
+u64 btrfs_get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags)
+{
+	return get_alloc_profile(fs_info, orig_flags);
+}
+
+void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
+{
+	atomic_inc(&cache->count);
+}
+
+void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
+{
+	if (atomic_dec_and_test(&cache->count)) {
+		WARN_ON(cache->pinned > 0);
+		WARN_ON(cache->reserved > 0);
+
+		/*
+		 * If not empty, someone is still holding mutex of
+		 * full_stripe_lock, which can only be released by caller.
+		 * And it will definitely cause use-after-free when caller
+		 * tries to release full stripe lock.
+		 *
+		 * No better way to resolve, but only to warn.
+		 */
+		WARN_ON(!RB_EMPTY_ROOT(&cache->full_stripe_locks_root.root));
+		kfree(cache->free_space_ctl);
+		kfree(cache);
+	}
+}
+
+/*
+ * This adds the block group to the fs_info rb tree for the block group cache
+ */
+static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
+				struct btrfs_block_group_cache *block_group)
+{
+	struct rb_node **p;
+	struct rb_node *parent = NULL;
+	struct btrfs_block_group_cache *cache;
+
+	spin_lock(&info->block_group_cache_lock);
+	p = &info->block_group_cache_tree.rb_node;
+
+	while (*p) {
+		parent = *p;
+		cache = rb_entry(parent, struct btrfs_block_group_cache,
+				 cache_node);
+		if (block_group->key.objectid < cache->key.objectid) {
+			p = &(*p)->rb_left;
+		} else if (block_group->key.objectid > cache->key.objectid) {
+			p = &(*p)->rb_right;
+		} else {
+			spin_unlock(&info->block_group_cache_lock);
+			return -EEXIST;
+		}
+	}
+
+	rb_link_node(&block_group->cache_node, parent, p);
+	rb_insert_color(&block_group->cache_node,
+			&info->block_group_cache_tree);
+
+	if (info->first_logical_byte > block_group->key.objectid)
+		info->first_logical_byte = block_group->key.objectid;
+
+	spin_unlock(&info->block_group_cache_lock);
+
+	return 0;
+}
+
+/*
+ * This will return the block group at or after bytenr if contains is 0, else
+ * it will return the block group that contains the bytenr
+ */
+static struct btrfs_block_group_cache *block_group_cache_tree_search(
+		struct btrfs_fs_info *info, u64 bytenr, int contains)
+{
+	struct btrfs_block_group_cache *cache, *ret = NULL;
+	struct rb_node *n;
+	u64 end, start;
+
+	spin_lock(&info->block_group_cache_lock);
+	n = info->block_group_cache_tree.rb_node;
+
+	while (n) {
+		cache = rb_entry(n, struct btrfs_block_group_cache,
+				 cache_node);
+		end = cache->key.objectid + cache->key.offset - 1;
+		start = cache->key.objectid;
+
+		if (bytenr < start) {
+			if (!contains && (!ret || start < ret->key.objectid))
+				ret = cache;
+			n = n->rb_left;
+		} else if (bytenr > start) {
+			if (contains && bytenr <= end) {
+				ret = cache;
+				break;
+			}
+			n = n->rb_right;
+		} else {
+			ret = cache;
+			break;
+		}
+	}
+	if (ret) {
+		btrfs_get_block_group(ret);
+		if (bytenr == 0 && info->first_logical_byte > ret->key.objectid)
+			info->first_logical_byte = ret->key.objectid;
+	}
+	spin_unlock(&info->block_group_cache_lock);
+
+	return ret;
+}
+
+/*
+ * Return the block group that starts at or after bytenr
+ */
+struct btrfs_block_group_cache *btrfs_lookup_first_block_group(
+		struct btrfs_fs_info *info, u64 bytenr)
+{
+	return block_group_cache_tree_search(info, bytenr, 0);
+}
+
+/*
+ * Return the block group that contains the given bytenr
+ */
+struct btrfs_block_group_cache *btrfs_lookup_block_group(
+		struct btrfs_fs_info *info, u64 bytenr)
+{
+	return block_group_cache_tree_search(info, bytenr, 1);
+}
+
+struct btrfs_block_group_cache *btrfs_next_block_group(
+		struct btrfs_block_group_cache *cache)
+{
+	struct btrfs_fs_info *fs_info = cache->fs_info;
+	struct rb_node *node;
+
+	spin_lock(&fs_info->block_group_cache_lock);
+
+	/* If our block group was removed, we need a full search. */
+	if (RB_EMPTY_NODE(&cache->cache_node)) {
+		const u64 next_bytenr = cache->key.objectid + cache->key.offset;
+
+		spin_unlock(&fs_info->block_group_cache_lock);
+		btrfs_put_block_group(cache);
+		cache = btrfs_lookup_first_block_group(fs_info, next_bytenr); return cache;
+	}
+	node = rb_next(&cache->cache_node);
+	btrfs_put_block_group(cache);
+	if (node) {
+		cache = rb_entry(node, struct btrfs_block_group_cache,
+				 cache_node);
+		btrfs_get_block_group(cache);
+	} else
+		cache = NULL;
+	spin_unlock(&fs_info->block_group_cache_lock);
+	return cache;
+}
+
+bool btrfs_inc_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr)
+{
+	struct btrfs_block_group_cache *bg;
+	bool ret = true;
+
+	bg = btrfs_lookup_block_group(fs_info, bytenr);
+	if (!bg)
+		return false;
+
+	spin_lock(&bg->lock);
+	if (bg->ro)
+		ret = false;
+	else
+		atomic_inc(&bg->nocow_writers);
+	spin_unlock(&bg->lock);
+
+	/* No put on block group, done by btrfs_dec_nocow_writers */
+	if (!ret)
+		btrfs_put_block_group(bg);
+
+	return ret;
+}
+
+void btrfs_dec_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr)
+{
+	struct btrfs_block_group_cache *bg;
+
+	bg = btrfs_lookup_block_group(fs_info, bytenr);
+	ASSERT(bg);
+	if (atomic_dec_and_test(&bg->nocow_writers))
+		wake_up_var(&bg->nocow_writers);
+	/*
+	 * Once for our lookup and once for the lookup done by a previous call
+	 * to btrfs_inc_nocow_writers()
+	 */
+	btrfs_put_block_group(bg);
+	btrfs_put_block_group(bg);
+}
+
+void btrfs_wait_nocow_writers(struct btrfs_block_group_cache *bg)
+{
+	wait_var_event(&bg->nocow_writers, !atomic_read(&bg->nocow_writers));
+}
+
+void btrfs_dec_block_group_reservations(struct btrfs_fs_info *fs_info,
+					const u64 start)
+{
+	struct btrfs_block_group_cache *bg;
+
+	bg = btrfs_lookup_block_group(fs_info, start);
+	ASSERT(bg);
+	if (atomic_dec_and_test(&bg->reservations))
+		wake_up_var(&bg->reservations);
+	btrfs_put_block_group(bg);
+}
+
+void btrfs_wait_block_group_reservations(struct btrfs_block_group_cache *bg)
+{
+	struct btrfs_space_info *space_info = bg->space_info;
+
+	ASSERT(bg->ro);
+
+	if (!(bg->flags & BTRFS_BLOCK_GROUP_DATA))
+		return;
+
+	/*
+	 * Our block group is read only but before we set it to read only,
+	 * some task might have had allocated an extent from it already, but it
+	 * has not yet created a respective ordered extent (and added it to a
+	 * root's list of ordered extents).
+	 * Therefore wait for any task currently allocating extents, since the
+	 * block group's reservations counter is incremented while a read lock
+	 * on the groups' semaphore is held and decremented after releasing
+	 * the read access on that semaphore and creating the ordered extent.
+	 */
+	down_write(&space_info->groups_sem);
+	up_write(&space_info->groups_sem);
+
+	wait_var_event(&bg->reservations, !atomic_read(&bg->reservations));
+}
+
+struct btrfs_caching_control *btrfs_get_caching_control(
+		struct btrfs_block_group_cache *cache)
+{
+	struct btrfs_caching_control *ctl;
+
+	spin_lock(&cache->lock);
+	if (!cache->caching_ctl) {
+		spin_unlock(&cache->lock);
+		return NULL;
+	}
+
+	ctl = cache->caching_ctl;
+	refcount_inc(&ctl->count);
+	spin_unlock(&cache->lock);
+	return ctl;
+}
+
+void btrfs_put_caching_control(struct btrfs_caching_control *ctl)
+{
+	if (refcount_dec_and_test(&ctl->count))
+		kfree(ctl);
+}
+
+/*
+ * When we wait for progress in the block group caching, its because our
+ * allocation attempt failed at least once.  So, we must sleep and let some
+ * progress happen before we try again.
+ *
+ * This function will sleep at least once waiting for new free space to show
+ * up, and then it will check the block group free space numbers for our min
+ * num_bytes.  Another option is to have it go ahead and look in the rbtree for
+ * a free extent of a given size, but this is a good start.
+ *
+ * Callers of this must check if cache->cached == BTRFS_CACHE_ERROR before using
+ * any of the information in this block group.
+ */
+void btrfs_wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
+					   u64 num_bytes)
+{
+	struct btrfs_caching_control *caching_ctl;
+
+	caching_ctl = btrfs_get_caching_control(cache);
+	if (!caching_ctl)
+		return;
+
+	wait_event(caching_ctl->wait, btrfs_block_group_cache_done(cache) ||
+		   (cache->free_space_ctl->free_space >= num_bytes));
+
+	btrfs_put_caching_control(caching_ctl);
+}
+
+int btrfs_wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
+{
+	struct btrfs_caching_control *caching_ctl;
+	int ret = 0;
+
+	caching_ctl = btrfs_get_caching_control(cache);
+	if (!caching_ctl)
+		return (cache->cached == BTRFS_CACHE_ERROR) ? -EIO : 0;
+
+	wait_event(caching_ctl->wait, btrfs_block_group_cache_done(cache));
+	if (cache->cached == BTRFS_CACHE_ERROR)
+		ret = -EIO;
+	btrfs_put_caching_control(caching_ctl);
+	return ret;
+}
+
+#ifdef CONFIG_BTRFS_DEBUG
+static void fragment_free_space(struct btrfs_block_group_cache *block_group)
+{
+	struct btrfs_fs_info *fs_info = block_group->fs_info;
+	u64 start = block_group->key.objectid;
+	u64 len = block_group->key.offset;
+	u64 chunk = block_group->flags & BTRFS_BLOCK_GROUP_METADATA ?
+		fs_info->nodesize : fs_info->sectorsize;
+	u64 step = chunk << 1;
+
+	while (len > chunk) {
+		btrfs_remove_free_space(block_group, start, chunk);
+		start += step;
+		if (len < step)
+			len = 0;
+		else
+			len -= step;
+	}
+}
+#endif
+
+/*
+ * This is only called by btrfs_cache_block_group, since we could have freed
+ * extents we need to check the pinned_extents for any extents that can't be
+ * used yet since their free space will be released as soon as the transaction
+ * commits.
+ */
+u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
+		       u64 start, u64 end)
+{
+	struct btrfs_fs_info *info = block_group->fs_info;
+	u64 extent_start, extent_end, size, total_added = 0;
+	int ret;
+
+	while (start < end) {
+		ret = find_first_extent_bit(info->pinned_extents, start,
+					    &extent_start, &extent_end,
+					    EXTENT_DIRTY | EXTENT_UPTODATE,
+					    NULL);
+		if (ret)
+			break;
+
+		if (extent_start <= start) {
+			start = extent_end + 1;
+		} else if (extent_start > start && extent_start < end) {
+			size = extent_start - start;
+			total_added += size;
+			ret = btrfs_add_free_space(block_group, start,
+						   size);
+			BUG_ON(ret); /* -ENOMEM or logic error */
+			start = extent_end + 1;
+		} else {
+			break;
+		}
+	}
+
+	if (start < end) {
+		size = end - start;
+		total_added += size;
+		ret = btrfs_add_free_space(block_group, start, size);
+		BUG_ON(ret); /* -ENOMEM or logic error */
+	}
+
+	return total_added;
+}
+
+static int load_extent_tree_free(struct btrfs_caching_control *caching_ctl)
+{
+	struct btrfs_block_group_cache *block_group = caching_ctl->block_group;
+	struct btrfs_fs_info *fs_info = block_group->fs_info;
+	struct btrfs_root *extent_root = fs_info->extent_root;
+	struct btrfs_path *path;
+	struct extent_buffer *leaf;
+	struct btrfs_key key;
+	u64 total_found = 0;
+	u64 last = 0;
+	u32 nritems;
+	int ret;
+	bool wakeup = true;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
+
+#ifdef CONFIG_BTRFS_DEBUG
+	/*
+	 * If we're fragmenting we don't want to make anybody think we can
+	 * allocate from this block group until we've had a chance to fragment
+	 * the free space.
+	 */
+	if (btrfs_should_fragment_free_space(block_group))
+		wakeup = false;
+#endif
+	/*
+	 * We don't want to deadlock with somebody trying to allocate a new
+	 * extent for the extent root while also trying to search the extent
+	 * root to add free space.  So we skip locking and search the commit
+	 * root, since its read-only
+	 */
+	path->skip_locking = 1;
+	path->search_commit_root = 1;
+	path->reada = READA_FORWARD;
+
+	key.objectid = last;
+	key.offset = 0;
+	key.type = BTRFS_EXTENT_ITEM_KEY;
+
+next:
+	ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
+	if (ret < 0)
+		goto out;
+
+	leaf = path->nodes[0];
+	nritems = btrfs_header_nritems(leaf);
+
+	while (1) {
+		if (btrfs_fs_closing(fs_info) > 1) {
+			last = (u64)-1;
+			break;
+		}
+
+		if (path->slots[0] < nritems) {
+			btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+		} else {
+			ret = btrfs_find_next_key(extent_root, path, &key, 0, 0);
+			if (ret)
+				break;
+
+			if (need_resched() ||
+			    rwsem_is_contended(&fs_info->commit_root_sem)) {
+				if (wakeup)
+					caching_ctl->progress = last;
+				btrfs_release_path(path);
+				up_read(&fs_info->commit_root_sem);
+				mutex_unlock(&caching_ctl->mutex);
+				cond_resched();
+				mutex_lock(&caching_ctl->mutex);
+				down_read(&fs_info->commit_root_sem);
+				goto next;
+			}
+
+			ret = btrfs_next_leaf(extent_root, path);
+			if (ret < 0)
+				goto out;
+			if (ret)
+				break;
+			leaf = path->nodes[0];
+			nritems = btrfs_header_nritems(leaf);
+			continue;
+		}
+
+		if (key.objectid < last) {
+			key.objectid = last;
+			key.offset = 0;
+			key.type = BTRFS_EXTENT_ITEM_KEY;
+
+			if (wakeup)
+				caching_ctl->progress = last;
+			btrfs_release_path(path);
+			goto next;
+		}
+
+		if (key.objectid < block_group->key.objectid) {
+			path->slots[0]++;
+			continue;
+		}
+
+		if (key.objectid >= block_group->key.objectid +
+		    block_group->key.offset)
+			break;
+
+		if (key.type == BTRFS_EXTENT_ITEM_KEY ||
+		    key.type == BTRFS_METADATA_ITEM_KEY) {
+			total_found += add_new_free_space(block_group, last,
+							  key.objectid);
+			if (key.type == BTRFS_METADATA_ITEM_KEY)
+				last = key.objectid +
+					fs_info->nodesize;
+			else
+				last = key.objectid + key.offset;
+
+			if (total_found > CACHING_CTL_WAKE_UP) {
+				total_found = 0;
+				if (wakeup)
+					wake_up(&caching_ctl->wait);
+			}
+		}
+		path->slots[0]++;
+	}
+	ret = 0;
+
+	total_found += add_new_free_space(block_group, last,
+					  block_group->key.objectid +
+					  block_group->key.offset);
+	caching_ctl->progress = (u64)-1;
+
+out:
+	btrfs_free_path(path);
+	return ret;
+}
+
+static noinline void caching_thread(struct btrfs_work *work)
+{
+	struct btrfs_block_group_cache *block_group;
+	struct btrfs_fs_info *fs_info;
+	struct btrfs_caching_control *caching_ctl;
+	int ret;
+
+	caching_ctl = container_of(work, struct btrfs_caching_control, work);
+	block_group = caching_ctl->block_group;
+	fs_info = block_group->fs_info;
+
+	mutex_lock(&caching_ctl->mutex);
+	down_read(&fs_info->commit_root_sem);
+
+	if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE))
+		ret = load_free_space_tree(caching_ctl);
+	else
+		ret = load_extent_tree_free(caching_ctl);
+
+	spin_lock(&block_group->lock);
+	block_group->caching_ctl = NULL;
+	block_group->cached = ret ? BTRFS_CACHE_ERROR : BTRFS_CACHE_FINISHED;
+	spin_unlock(&block_group->lock);
+
+#ifdef CONFIG_BTRFS_DEBUG
+	if (btrfs_should_fragment_free_space(block_group)) {
+		u64 bytes_used;
+
+		spin_lock(&block_group->space_info->lock);
+		spin_lock(&block_group->lock);
+		bytes_used = block_group->key.offset -
+			btrfs_block_group_used(&block_group->item);
+		block_group->space_info->bytes_used += bytes_used >> 1;
+		spin_unlock(&block_group->lock);
+		spin_unlock(&block_group->space_info->lock);
+		fragment_free_space(block_group);
+	}
+#endif
+
+	caching_ctl->progress = (u64)-1;
+
+	up_read(&fs_info->commit_root_sem);
+	btrfs_free_excluded_extents(block_group);
+	mutex_unlock(&caching_ctl->mutex);
+
+	wake_up(&caching_ctl->wait);
+
+	btrfs_put_caching_control(caching_ctl);
+	btrfs_put_block_group(block_group);
+}
+
+int btrfs_cache_block_group(struct btrfs_block_group_cache *cache,
+			    int load_cache_only)
+{
+	DEFINE_WAIT(wait);
+	struct btrfs_fs_info *fs_info = cache->fs_info;
+	struct btrfs_caching_control *caching_ctl;
+	int ret = 0;
+
+	caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS);
+	if (!caching_ctl)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&caching_ctl->list);
+	mutex_init(&caching_ctl->mutex);
+	init_waitqueue_head(&caching_ctl->wait);
+	caching_ctl->block_group = cache;
+	caching_ctl->progress = cache->key.objectid;
+	refcount_set(&caching_ctl->count, 1);
+	btrfs_init_work(&caching_ctl->work, btrfs_cache_helper,
+			caching_thread, NULL, NULL);
+
+	spin_lock(&cache->lock);
+	/*
+	 * This should be a rare occasion, but this could happen I think in the
+	 * case where one thread starts to load the space cache info, and then
+	 * some other thread starts a transaction commit which tries to do an
+	 * allocation while the other thread is still loading the space cache
+	 * info.  The previous loop should have kept us from choosing this block
+	 * group, but if we've moved to the state where we will wait on caching
+	 * block groups we need to first check if we're doing a fast load here,
+	 * so we can wait for it to finish, otherwise we could end up allocating
+	 * from a block group who's cache gets evicted for one reason or
+	 * another.
+	 */
+	while (cache->cached == BTRFS_CACHE_FAST) {
+		struct btrfs_caching_control *ctl;
+
+		ctl = cache->caching_ctl;
+		refcount_inc(&ctl->count);
+		prepare_to_wait(&ctl->wait, &wait, TASK_UNINTERRUPTIBLE);
+		spin_unlock(&cache->lock);
+
+		schedule();
+
+		finish_wait(&ctl->wait, &wait);
+		btrfs_put_caching_control(ctl);
+		spin_lock(&cache->lock);
+	}
+
+	if (cache->cached != BTRFS_CACHE_NO) {
+		spin_unlock(&cache->lock);
+		kfree(caching_ctl);
+		return 0;
+	}
+	WARN_ON(cache->caching_ctl);
+	cache->caching_ctl = caching_ctl;
+	cache->cached = BTRFS_CACHE_FAST;
+	spin_unlock(&cache->lock);
+
+	if (btrfs_test_opt(fs_info, SPACE_CACHE)) {
+		mutex_lock(&caching_ctl->mutex);
+		ret = load_free_space_cache(cache);
+
+		spin_lock(&cache->lock);
+		if (ret == 1) {
+			cache->caching_ctl = NULL;
+			cache->cached = BTRFS_CACHE_FINISHED;
+			cache->last_byte_to_unpin = (u64)-1;
+			caching_ctl->progress = (u64)-1;
+		} else {
+			if (load_cache_only) {
+				cache->caching_ctl = NULL;
+				cache->cached = BTRFS_CACHE_NO;
+			} else {
+				cache->cached = BTRFS_CACHE_STARTED;
+				cache->has_caching_ctl = 1;
+			}
+		}
+		spin_unlock(&cache->lock);
+#ifdef CONFIG_BTRFS_DEBUG
+		if (ret == 1 &&
+		    btrfs_should_fragment_free_space(cache)) {
+			u64 bytes_used;
+
+			spin_lock(&cache->space_info->lock);
+			spin_lock(&cache->lock);
+			bytes_used = cache->key.offset -
+				btrfs_block_group_used(&cache->item);
+			cache->space_info->bytes_used += bytes_used >> 1;
+			spin_unlock(&cache->lock);
+			spin_unlock(&cache->space_info->lock);
+			fragment_free_space(cache);
+		}
+#endif
+		mutex_unlock(&caching_ctl->mutex);
+
+		wake_up(&caching_ctl->wait);
+		if (ret == 1) {
+			btrfs_put_caching_control(caching_ctl);
+			btrfs_free_excluded_extents(cache);
+			return 0;
+		}
+	} else {
+		/*
+		 * We're either using the free space tree or no caching at all.
+		 * Set cached to the appropriate value and wakeup any waiters.
+		 */
+		spin_lock(&cache->lock);
+		if (load_cache_only) {
+			cache->caching_ctl = NULL;
+			cache->cached = BTRFS_CACHE_NO;
+		} else {
+			cache->cached = BTRFS_CACHE_STARTED;
+			cache->has_caching_ctl = 1;
+		}
+		spin_unlock(&cache->lock);
+		wake_up(&caching_ctl->wait);
+	}
+
+	if (load_cache_only) {
+		btrfs_put_caching_control(caching_ctl);
+		return 0;
+	}
+
+	down_write(&fs_info->commit_root_sem);
+	refcount_inc(&caching_ctl->count);
+	list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups);
+	up_write(&fs_info->commit_root_sem);
+
+	btrfs_get_block_group(cache);
+
+	btrfs_queue_work(fs_info->caching_workers, &caching_ctl->work);
+
+	return ret;
+}
+
+static void clear_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
+{
+	u64 extra_flags = chunk_to_extended(flags) &
+				BTRFS_EXTENDED_PROFILE_MASK;
+
+	write_seqlock(&fs_info->profiles_lock);
+	if (flags & BTRFS_BLOCK_GROUP_DATA)
+		fs_info->avail_data_alloc_bits &= ~extra_flags;
+	if (flags & BTRFS_BLOCK_GROUP_METADATA)
+		fs_info->avail_metadata_alloc_bits &= ~extra_flags;
+	if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
+		fs_info->avail_system_alloc_bits &= ~extra_flags;
+	write_sequnlock(&fs_info->profiles_lock);
+}
+
+/*
+ * Clear incompat bits for the following feature(s):
+ *
+ * - RAID56 - in case there's neither RAID5 nor RAID6 profile block group
+ *            in the whole filesystem
+ */
+static void clear_incompat_bg_bits(struct btrfs_fs_info *fs_info, u64 flags)
+{
+	if (flags & BTRFS_BLOCK_GROUP_RAID56_MASK) {
+		struct list_head *head = &fs_info->space_info;
+		struct btrfs_space_info *sinfo;
+
+		list_for_each_entry_rcu(sinfo, head, list) {
+			bool found = false;
+
+			down_read(&sinfo->groups_sem);
+			if (!list_empty(&sinfo->block_groups[BTRFS_RAID_RAID5]))
+				found = true;
+			if (!list_empty(&sinfo->block_groups[BTRFS_RAID_RAID6]))
+				found = true;
+			up_read(&sinfo->groups_sem);
+
+			if (found)
+				return;
+		}
+		btrfs_clear_fs_incompat(fs_info, RAID56);
+	}
+}
+
+int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
+			     u64 group_start, struct extent_map *em)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_root *root = fs_info->extent_root;
+	struct btrfs_path *path;
+	struct btrfs_block_group_cache *block_group;
+	struct btrfs_free_cluster *cluster;
+	struct btrfs_root *tree_root = fs_info->tree_root;
+	struct btrfs_key key;
+	struct inode *inode;
+	struct kobject *kobj = NULL;
+	int ret;
+	int index;
+	int factor;
+	struct btrfs_caching_control *caching_ctl = NULL;
+	bool remove_em;
+	bool remove_rsv = false;
+
+	block_group = btrfs_lookup_block_group(fs_info, group_start);
+	BUG_ON(!block_group);
+	BUG_ON(!block_group->ro);
+
+	trace_btrfs_remove_block_group(block_group);
+	/*
+	 * Free the reserved super bytes from this block group before
+	 * remove it.
+	 */
+	btrfs_free_excluded_extents(block_group);
+	btrfs_free_ref_tree_range(fs_info, block_group->key.objectid,
+				  block_group->key.offset);
+
+	memcpy(&key, &block_group->key, sizeof(key));
+	index = btrfs_bg_flags_to_raid_index(block_group->flags);
+	factor = btrfs_bg_type_to_factor(block_group->flags);
+
+	/* make sure this block group isn't part of an allocation cluster */
+	cluster = &fs_info->data_alloc_cluster;
+	spin_lock(&cluster->refill_lock);
+	btrfs_return_cluster_to_free_space(block_group, cluster);
+	spin_unlock(&cluster->refill_lock);
+
+	/*
+	 * make sure this block group isn't part of a metadata
+	 * allocation cluster
+	 */
+	cluster = &fs_info->meta_alloc_cluster;
+	spin_lock(&cluster->refill_lock);
+	btrfs_return_cluster_to_free_space(block_group, cluster);
+	spin_unlock(&cluster->refill_lock);
+
+	path = btrfs_alloc_path();
+	if (!path) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	/*
+	 * get the inode first so any iput calls done for the io_list
+	 * aren't the final iput (no unlinks allowed now)
+	 */
+	inode = lookup_free_space_inode(block_group, path);
+
+	mutex_lock(&trans->transaction->cache_write_mutex);
+	/*
+	 * Make sure our free space cache IO is done before removing the
+	 * free space inode
+	 */
+	spin_lock(&trans->transaction->dirty_bgs_lock);
+	if (!list_empty(&block_group->io_list)) {
+		list_del_init(&block_group->io_list);
+
+		WARN_ON(!IS_ERR(inode) && inode != block_group->io_ctl.inode);
+
+		spin_unlock(&trans->transaction->dirty_bgs_lock);
+		btrfs_wait_cache_io(trans, block_group, path);
+		btrfs_put_block_group(block_group);
+		spin_lock(&trans->transaction->dirty_bgs_lock);
+	}
+
+	if (!list_empty(&block_group->dirty_list)) {
+		list_del_init(&block_group->dirty_list);
+		remove_rsv = true;
+		btrfs_put_block_group(block_group);
+	}
+	spin_unlock(&trans->transaction->dirty_bgs_lock);
+	mutex_unlock(&trans->transaction->cache_write_mutex);
+
+	if (!IS_ERR(inode)) {
+		ret = btrfs_orphan_add(trans, BTRFS_I(inode));
+		if (ret) {
+			btrfs_add_delayed_iput(inode);
+			goto out;
+		}
+		clear_nlink(inode);
+		/* One for the block groups ref */
+		spin_lock(&block_group->lock);
+		if (block_group->iref) {
+			block_group->iref = 0;
+			block_group->inode = NULL;
+			spin_unlock(&block_group->lock);
+			iput(inode);
+		} else {
+			spin_unlock(&block_group->lock);
+		}
+		/* One for our lookup ref */
+		btrfs_add_delayed_iput(inode);
+	}
+
+	key.objectid = BTRFS_FREE_SPACE_OBJECTID;
+	key.offset = block_group->key.objectid;
+	key.type = 0;
+
+	ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
+	if (ret < 0)
+		goto out;
+	if (ret > 0)
+		btrfs_release_path(path);
+	if (ret == 0) {
+		ret = btrfs_del_item(trans, tree_root, path);
+		if (ret)
+			goto out;
+		btrfs_release_path(path);
+	}
+
+	spin_lock(&fs_info->block_group_cache_lock);
+	rb_erase(&block_group->cache_node,
+		 &fs_info->block_group_cache_tree);
+	RB_CLEAR_NODE(&block_group->cache_node);
+
+	if (fs_info->first_logical_byte == block_group->key.objectid)
+		fs_info->first_logical_byte = (u64)-1;
+	spin_unlock(&fs_info->block_group_cache_lock);
+
+	down_write(&block_group->space_info->groups_sem);
+	/*
+	 * we must use list_del_init so people can check to see if they
+	 * are still on the list after taking the semaphore
+	 */
+	list_del_init(&block_group->list);
+	if (list_empty(&block_group->space_info->block_groups[index])) {
+		kobj = block_group->space_info->block_group_kobjs[index];
+		block_group->space_info->block_group_kobjs[index] = NULL;
+		clear_avail_alloc_bits(fs_info, block_group->flags);
+	}
+	up_write(&block_group->space_info->groups_sem);
+	clear_incompat_bg_bits(fs_info, block_group->flags);
+	if (kobj) {
+		kobject_del(kobj);
+		kobject_put(kobj);
+	}
+
+	if (block_group->has_caching_ctl)
+		caching_ctl = btrfs_get_caching_control(block_group);
+	if (block_group->cached == BTRFS_CACHE_STARTED)
+		btrfs_wait_block_group_cache_done(block_group);
+	if (block_group->has_caching_ctl) {
+		down_write(&fs_info->commit_root_sem);
+		if (!caching_ctl) {
+			struct btrfs_caching_control *ctl;
+
+			list_for_each_entry(ctl,
+				    &fs_info->caching_block_groups, list)
+				if (ctl->block_group == block_group) {
+					caching_ctl = ctl;
+					refcount_inc(&caching_ctl->count);
+					break;
+				}
+		}
+		if (caching_ctl)
+			list_del_init(&caching_ctl->list);
+		up_write(&fs_info->commit_root_sem);
+		if (caching_ctl) {
+			/* Once for the caching bgs list and once for us. */
+			btrfs_put_caching_control(caching_ctl);
+			btrfs_put_caching_control(caching_ctl);
+		}
+	}
+
+	spin_lock(&trans->transaction->dirty_bgs_lock);
+	WARN_ON(!list_empty(&block_group->dirty_list));
+	WARN_ON(!list_empty(&block_group->io_list));
+	spin_unlock(&trans->transaction->dirty_bgs_lock);
+
+	btrfs_remove_free_space_cache(block_group);
+
+	spin_lock(&block_group->space_info->lock);
+	list_del_init(&block_group->ro_list);
+
+	if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
+		WARN_ON(block_group->space_info->total_bytes
+			< block_group->key.offset);
+		WARN_ON(block_group->space_info->bytes_readonly
+			< block_group->key.offset);
+		WARN_ON(block_group->space_info->disk_total
+			< block_group->key.offset * factor);
+	}
+	block_group->space_info->total_bytes -= block_group->key.offset;
+	block_group->space_info->bytes_readonly -= block_group->key.offset;
+	block_group->space_info->disk_total -= block_group->key.offset * factor;
+
+	spin_unlock(&block_group->space_info->lock);
+
+	memcpy(&key, &block_group->key, sizeof(key));
+
+	mutex_lock(&fs_info->chunk_mutex);
+	spin_lock(&block_group->lock);
+	block_group->removed = 1;
+	/*
+	 * At this point trimming can't start on this block group, because we
+	 * removed the block group from the tree fs_info->block_group_cache_tree
+	 * so no one can't find it anymore and even if someone already got this
+	 * block group before we removed it from the rbtree, they have already
+	 * incremented block_group->trimming - if they didn't, they won't find
+	 * any free space entries because we already removed them all when we
+	 * called btrfs_remove_free_space_cache().
+	 *
+	 * And we must not remove the extent map from the fs_info->mapping_tree
+	 * to prevent the same logical address range and physical device space
+	 * ranges from being reused for a new block group. This is because our
+	 * fs trim operation (btrfs_trim_fs() / btrfs_ioctl_fitrim()) is
+	 * completely transactionless, so while it is trimming a range the
+	 * currently running transaction might finish and a new one start,
+	 * allowing for new block groups to be created that can reuse the same
+	 * physical device locations unless we take this special care.
+	 *
+	 * There may also be an implicit trim operation if the file system
+	 * is mounted with -odiscard. The same protections must remain
+	 * in place until the extents have been discarded completely when
+	 * the transaction commit has completed.
+	 */
+	remove_em = (atomic_read(&block_group->trimming) == 0);
+	spin_unlock(&block_group->lock);
+
+	mutex_unlock(&fs_info->chunk_mutex);
+
+	ret = remove_block_group_free_space(trans, block_group);
+	if (ret)
+		goto out;
+
+	btrfs_put_block_group(block_group);
+	btrfs_put_block_group(block_group);
+
+	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+	if (ret > 0)
+		ret = -EIO;
+	if (ret < 0)
+		goto out;
+
+	ret = btrfs_del_item(trans, root, path);
+	if (ret)
+		goto out;
+
+	if (remove_em) {
+		struct extent_map_tree *em_tree;
+
+		em_tree = &fs_info->mapping_tree;
+		write_lock(&em_tree->lock);
+		remove_extent_mapping(em_tree, em);
+		write_unlock(&em_tree->lock);
+		/* once for the tree */
+		free_extent_map(em);
+	}
+out:
+	if (remove_rsv)
+		btrfs_delayed_refs_rsv_release(fs_info, 1);
+	btrfs_free_path(path);
+	return ret;
+}
+
+struct btrfs_trans_handle *btrfs_start_trans_remove_block_group(
+		struct btrfs_fs_info *fs_info, const u64 chunk_offset)
+{
+	struct extent_map_tree *em_tree = &fs_info->mapping_tree;
+	struct extent_map *em;
+	struct map_lookup *map;
+	unsigned int num_items;
+
+	read_lock(&em_tree->lock);
+	em = lookup_extent_mapping(em_tree, chunk_offset, 1);
+	read_unlock(&em_tree->lock);
+	ASSERT(em && em->start == chunk_offset);
+
+	/*
+	 * We need to reserve 3 + N units from the metadata space info in order
+	 * to remove a block group (done at btrfs_remove_chunk() and at
+	 * btrfs_remove_block_group()), which are used for:
+	 *
+	 * 1 unit for adding the free space inode's orphan (located in the tree
+	 * of tree roots).
+	 * 1 unit for deleting the block group item (located in the extent
+	 * tree).
+	 * 1 unit for deleting the free space item (located in tree of tree
+	 * roots).
+	 * N units for deleting N device extent items corresponding to each
+	 * stripe (located in the device tree).
+	 *
+	 * In order to remove a block group we also need to reserve units in the
+	 * system space info in order to update the chunk tree (update one or
+	 * more device items and remove one chunk item), but this is done at
+	 * btrfs_remove_chunk() through a call to check_system_chunk().
+	 */
+	map = em->map_lookup;
+	num_items = 3 + map->num_stripes;
+	free_extent_map(em);
+
+	return btrfs_start_transaction_fallback_global_rsv(fs_info->extent_root,
+							   num_items, 1);
+}
+
+/*
+ * Mark block group @cache read-only, so later write won't happen to block
+ * group @cache.
+ *
+ * If @force is not set, this function will only mark the block group readonly
+ * if we have enough free space (1M) in other metadata/system block groups.
+ * If @force is not set, this function will mark the block group readonly
+ * without checking free space.
+ *
+ * NOTE: This function doesn't care if other block groups can contain all the
+ * data in this block group. That check should be done by relocation routine,
+ * not this function.
+ */
+static int inc_block_group_ro(struct btrfs_block_group_cache *cache, int force)
+{
+	struct btrfs_space_info *sinfo = cache->space_info;
+	u64 num_bytes;
+	u64 sinfo_used;
+	u64 min_allocable_bytes;
+	int ret = -ENOSPC;
+
+	/*
+	 * We need some metadata space and system metadata space for
+	 * allocating chunks in some corner cases until we force to set
+	 * it to be readonly.
+	 */
+	if ((sinfo->flags &
+	     (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA)) &&
+	    !force)
+		min_allocable_bytes = SZ_1M;
+	else
+		min_allocable_bytes = 0;
+
+	spin_lock(&sinfo->lock);
+	spin_lock(&cache->lock);
+
+	if (cache->ro) {
+		cache->ro++;
+		ret = 0;
+		goto out;
+	}
+
+	num_bytes = cache->key.offset - cache->reserved - cache->pinned -
+		    cache->bytes_super - btrfs_block_group_used(&cache->item);
+	sinfo_used = btrfs_space_info_used(sinfo, true);
+
+	/*
+	 * sinfo_used + num_bytes should always <= sinfo->total_bytes.
+	 *
+	 * Here we make sure if we mark this bg RO, we still have enough
+	 * free space as buffer (if min_allocable_bytes is not 0).
+	 */
+	if (sinfo_used + num_bytes + min_allocable_bytes <=
+	    sinfo->total_bytes) {
+		sinfo->bytes_readonly += num_bytes;
+		cache->ro++;
+		list_add_tail(&cache->ro_list, &sinfo->ro_bgs);
+		ret = 0;
+	}
+out:
+	spin_unlock(&cache->lock);
+	spin_unlock(&sinfo->lock);
+	if (ret == -ENOSPC && btrfs_test_opt(cache->fs_info, ENOSPC_DEBUG)) {
+		btrfs_info(cache->fs_info,
+			"unable to make block group %llu ro",
+			cache->key.objectid);
+		btrfs_info(cache->fs_info,
+			"sinfo_used=%llu bg_num_bytes=%llu min_allocable=%llu",
+			sinfo_used, num_bytes, min_allocable_bytes);
+		btrfs_dump_space_info(cache->fs_info, cache->space_info, 0, 0);
+	}
+	return ret;
+}
+
+/*
+ * Process the unused_bgs list and remove any that don't have any allocated
+ * space inside of them.
+ */
+void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
+{
+	struct btrfs_block_group_cache *block_group;
+	struct btrfs_space_info *space_info;
+	struct btrfs_trans_handle *trans;
+	int ret = 0;
+
+	if (!test_bit(BTRFS_FS_OPEN, &fs_info->flags))
+		return;
+
+	spin_lock(&fs_info->unused_bgs_lock);
+	while (!list_empty(&fs_info->unused_bgs)) {
+		u64 start, end;
+		int trimming;
+
+		block_group = list_first_entry(&fs_info->unused_bgs,
+					       struct btrfs_block_group_cache,
+					       bg_list);
+		list_del_init(&block_group->bg_list);
+
+		space_info = block_group->space_info;
+
+		if (ret || btrfs_mixed_space_info(space_info)) {
+			btrfs_put_block_group(block_group);
+			continue;
+		}
+		spin_unlock(&fs_info->unused_bgs_lock);
+
+		mutex_lock(&fs_info->delete_unused_bgs_mutex);
+
+		/* Don't want to race with allocators so take the groups_sem */
+		down_write(&space_info->groups_sem);
+		spin_lock(&block_group->lock);
+		if (block_group->reserved || block_group->pinned ||
+		    btrfs_block_group_used(&block_group->item) ||
+		    block_group->ro ||
+		    list_is_singular(&block_group->list)) {
+			/*
+			 * We want to bail if we made new allocations or have
+			 * outstanding allocations in this block group.  We do
+			 * the ro check in case balance is currently acting on
+			 * this block group.
+			 */
+			trace_btrfs_skip_unused_block_group(block_group);
+			spin_unlock(&block_group->lock);
+			up_write(&space_info->groups_sem);
+			goto next;
+		}
+		spin_unlock(&block_group->lock);
+
+		/* We don't want to force the issue, only flip if it's ok. */
+		ret = inc_block_group_ro(block_group, 0);
+		up_write(&space_info->groups_sem);
+		if (ret < 0) {
+			ret = 0;
+			goto next;
+		}
+
+		/*
+		 * Want to do this before we do anything else so we can recover
+		 * properly if we fail to join the transaction.
+		 */
+		trans = btrfs_start_trans_remove_block_group(fs_info,
+						     block_group->key.objectid);
+		if (IS_ERR(trans)) {
+			btrfs_dec_block_group_ro(block_group);
+			ret = PTR_ERR(trans);
+			goto next;
+		}
+
+		/*
+		 * We could have pending pinned extents for this block group,
+		 * just delete them, we don't care about them anymore.
+		 */
+		start = block_group->key.objectid;
+		end = start + block_group->key.offset - 1;
+		/*
+		 * Hold the unused_bg_unpin_mutex lock to avoid racing with
+		 * btrfs_finish_extent_commit(). If we are at transaction N,
+		 * another task might be running finish_extent_commit() for the
+		 * previous transaction N - 1, and have seen a range belonging
+		 * to the block group in freed_extents[] before we were able to
+		 * clear the whole block group range from freed_extents[]. This
+		 * means that task can lookup for the block group after we
+		 * unpinned it from freed_extents[] and removed it, leading to
+		 * a BUG_ON() at btrfs_unpin_extent_range().
+		 */
+		mutex_lock(&fs_info->unused_bg_unpin_mutex);
+		ret = clear_extent_bits(&fs_info->freed_extents[0], start, end,
+				  EXTENT_DIRTY);
+		if (ret) {
+			mutex_unlock(&fs_info->unused_bg_unpin_mutex);
+			btrfs_dec_block_group_ro(block_group);
+			goto end_trans;
+		}
+		ret = clear_extent_bits(&fs_info->freed_extents[1], start, end,
+				  EXTENT_DIRTY);
+		if (ret) {
+			mutex_unlock(&fs_info->unused_bg_unpin_mutex);
+			btrfs_dec_block_group_ro(block_group);
+			goto end_trans;
+		}
+		mutex_unlock(&fs_info->unused_bg_unpin_mutex);
+
+		/* Reset pinned so btrfs_put_block_group doesn't complain */
+		spin_lock(&space_info->lock);
+		spin_lock(&block_group->lock);
+
+		btrfs_space_info_update_bytes_pinned(fs_info, space_info,
+						     -block_group->pinned);
+		space_info->bytes_readonly += block_group->pinned;
+		percpu_counter_add_batch(&space_info->total_bytes_pinned,
+				   -block_group->pinned,
+				   BTRFS_TOTAL_BYTES_PINNED_BATCH);
+		block_group->pinned = 0;
+
+		spin_unlock(&block_group->lock);
+		spin_unlock(&space_info->lock);
+
+		/* DISCARD can flip during remount */
+		trimming = btrfs_test_opt(fs_info, DISCARD);
+
+		/* Implicit trim during transaction commit. */
+		if (trimming)
+			btrfs_get_block_group_trimming(block_group);
+
+		/*
+		 * Btrfs_remove_chunk will abort the transaction if things go
+		 * horribly wrong.
+		 */
+		ret = btrfs_remove_chunk(trans, block_group->key.objectid);
+
+		if (ret) {
+			if (trimming)
+				btrfs_put_block_group_trimming(block_group);
+			goto end_trans;
+		}
+
+		/*
+		 * If we're not mounted with -odiscard, we can just forget
+		 * about this block group. Otherwise we'll need to wait
+		 * until transaction commit to do the actual discard.
+		 */
+		if (trimming) {
+			spin_lock(&fs_info->unused_bgs_lock);
+			/*
+			 * A concurrent scrub might have added us to the list
+			 * fs_info->unused_bgs, so use a list_move operation
+			 * to add the block group to the deleted_bgs list.
+			 */
+			list_move(&block_group->bg_list,
+				  &trans->transaction->deleted_bgs);
+			spin_unlock(&fs_info->unused_bgs_lock);
+			btrfs_get_block_group(block_group);
+		}
+end_trans:
+		btrfs_end_transaction(trans);
+next:
+		mutex_unlock(&fs_info->delete_unused_bgs_mutex);
+		btrfs_put_block_group(block_group);
+		spin_lock(&fs_info->unused_bgs_lock);
+	}
+	spin_unlock(&fs_info->unused_bgs_lock);
+}
+
+void btrfs_mark_bg_unused(struct btrfs_block_group_cache *bg)
+{
+	struct btrfs_fs_info *fs_info = bg->fs_info;
+
+	spin_lock(&fs_info->unused_bgs_lock);
+	if (list_empty(&bg->bg_list)) {
+		btrfs_get_block_group(bg);
+		trace_btrfs_add_unused_block_group(bg);
+		list_add_tail(&bg->bg_list, &fs_info->unused_bgs);
+	}
+	spin_unlock(&fs_info->unused_bgs_lock);
+}
+
+static int find_first_block_group(struct btrfs_fs_info *fs_info,
+				  struct btrfs_path *path,
+				  struct btrfs_key *key)
+{
+	struct btrfs_root *root = fs_info->extent_root;
+	int ret = 0;
+	struct btrfs_key found_key;
+	struct extent_buffer *leaf;
+	struct btrfs_block_group_item bg;
+	u64 flags;
+	int slot;
+
+	ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
+	if (ret < 0)
+		goto out;
+
+	while (1) {
+		slot = path->slots[0];
+		leaf = path->nodes[0];
+		if (slot >= btrfs_header_nritems(leaf)) {
+			ret = btrfs_next_leaf(root, path);
+			if (ret == 0)
+				continue;
+			if (ret < 0)
+				goto out;
+			break;
+		}
+		btrfs_item_key_to_cpu(leaf, &found_key, slot);
+
+		if (found_key.objectid >= key->objectid &&
+		    found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
+			struct extent_map_tree *em_tree;
+			struct extent_map *em;
+
+			em_tree = &root->fs_info->mapping_tree;
+			read_lock(&em_tree->lock);
+			em = lookup_extent_mapping(em_tree, found_key.objectid,
+						   found_key.offset);
+			read_unlock(&em_tree->lock);
+			if (!em) {
+				btrfs_err(fs_info,
+			"logical %llu len %llu found bg but no related chunk",
+					  found_key.objectid, found_key.offset);
+				ret = -ENOENT;
+			} else if (em->start != found_key.objectid ||
+				   em->len != found_key.offset) {
+				btrfs_err(fs_info,
+		"block group %llu len %llu mismatch with chunk %llu len %llu",
+					  found_key.objectid, found_key.offset,
+					  em->start, em->len);
+				ret = -EUCLEAN;
+			} else {
+				read_extent_buffer(leaf, &bg,
+					btrfs_item_ptr_offset(leaf, slot),
+					sizeof(bg));
+				flags = btrfs_block_group_flags(&bg) &
+					BTRFS_BLOCK_GROUP_TYPE_MASK;
+
+				if (flags != (em->map_lookup->type &
+					      BTRFS_BLOCK_GROUP_TYPE_MASK)) {
+					btrfs_err(fs_info,
+"block group %llu len %llu type flags 0x%llx mismatch with chunk type flags 0x%llx",
+						found_key.objectid,
+						found_key.offset, flags,
+						(BTRFS_BLOCK_GROUP_TYPE_MASK &
+						 em->map_lookup->type));
+					ret = -EUCLEAN;
+				} else {
+					ret = 0;
+				}
+			}
+			free_extent_map(em);
+			goto out;
+		}
+		path->slots[0]++;
+	}
+out:
+	return ret;
+}
+
+static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
+{
+	u64 extra_flags = chunk_to_extended(flags) &
+				BTRFS_EXTENDED_PROFILE_MASK;
+
+	write_seqlock(&fs_info->profiles_lock);
+	if (flags & BTRFS_BLOCK_GROUP_DATA)
+		fs_info->avail_data_alloc_bits |= extra_flags;
+	if (flags & BTRFS_BLOCK_GROUP_METADATA)
+		fs_info->avail_metadata_alloc_bits |= extra_flags;
+	if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
+		fs_info->avail_system_alloc_bits |= extra_flags;
+	write_sequnlock(&fs_info->profiles_lock);
+}
+
+static int exclude_super_stripes(struct btrfs_block_group_cache *cache)
+{
+	struct btrfs_fs_info *fs_info = cache->fs_info;
+	u64 bytenr;
+	u64 *logical;
+	int stripe_len;
+	int i, nr, ret;
+
+	if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) {
+		stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid;
+		cache->bytes_super += stripe_len;
+		ret = btrfs_add_excluded_extent(fs_info, cache->key.objectid,
+						stripe_len);
+		if (ret)
+			return ret;
+	}
+
+	for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
+		bytenr = btrfs_sb_offset(i);
+		ret = btrfs_rmap_block(fs_info, cache->key.objectid,
+				       bytenr, &logical, &nr, &stripe_len);
+		if (ret)
+			return ret;
+
+		while (nr--) {
+			u64 start, len;
+
+			if (logical[nr] > cache->key.objectid +
+			    cache->key.offset)
+				continue;
+
+			if (logical[nr] + stripe_len <= cache->key.objectid)
+				continue;
+
+			start = logical[nr];
+			if (start < cache->key.objectid) {
+				start = cache->key.objectid;
+				len = (logical[nr] + stripe_len) - start;
+			} else {
+				len = min_t(u64, stripe_len,
+					    cache->key.objectid +
+					    cache->key.offset - start);
+			}
+
+			cache->bytes_super += len;
+			ret = btrfs_add_excluded_extent(fs_info, start, len);
+			if (ret) {
+				kfree(logical);
+				return ret;
+			}
+		}
+
+		kfree(logical);
+	}
+	return 0;
+}
+
+static void link_block_group(struct btrfs_block_group_cache *cache)
+{
+	struct btrfs_space_info *space_info = cache->space_info;
+	int index = btrfs_bg_flags_to_raid_index(cache->flags);
+	bool first = false;
+
+	down_write(&space_info->groups_sem);
+	if (list_empty(&space_info->block_groups[index]))
+		first = true;
+	list_add_tail(&cache->list, &space_info->block_groups[index]);
+	up_write(&space_info->groups_sem);
+
+	if (first)
+		btrfs_sysfs_add_block_group_type(cache);
+}
+
+static struct btrfs_block_group_cache *btrfs_create_block_group_cache(
+		struct btrfs_fs_info *fs_info, u64 start, u64 size)
+{
+	struct btrfs_block_group_cache *cache;
+
+	cache = kzalloc(sizeof(*cache), GFP_NOFS);
+	if (!cache)
+		return NULL;
+
+	cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl),
+					GFP_NOFS);
+	if (!cache->free_space_ctl) {
+		kfree(cache);
+		return NULL;
+	}
+
+	cache->key.objectid = start;
+	cache->key.offset = size;
+	cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
+
+	cache->fs_info = fs_info;
+	cache->full_stripe_len = btrfs_full_stripe_len(fs_info, start);
+	set_free_space_tree_thresholds(cache);
+
+	atomic_set(&cache->count, 1);
+	spin_lock_init(&cache->lock);
+	init_rwsem(&cache->data_rwsem);
+	INIT_LIST_HEAD(&cache->list);
+	INIT_LIST_HEAD(&cache->cluster_list);
+	INIT_LIST_HEAD(&cache->bg_list);
+	INIT_LIST_HEAD(&cache->ro_list);
+	INIT_LIST_HEAD(&cache->dirty_list);
+	INIT_LIST_HEAD(&cache->io_list);
+	btrfs_init_free_space_ctl(cache);
+	atomic_set(&cache->trimming, 0);
+	mutex_init(&cache->free_space_lock);
+	btrfs_init_full_stripe_locks_tree(&cache->full_stripe_locks_root);
+
+	return cache;
+}
+
+/*
+ * Iterate all chunks and verify that each of them has the corresponding block
+ * group
+ */
+static int check_chunk_block_group_mappings(struct btrfs_fs_info *fs_info)
+{
+	struct extent_map_tree *map_tree = &fs_info->mapping_tree;
+	struct extent_map *em;
+	struct btrfs_block_group_cache *bg;
+	u64 start = 0;
+	int ret = 0;
+
+	while (1) {
+		read_lock(&map_tree->lock);
+		/*
+		 * lookup_extent_mapping will return the first extent map
+		 * intersecting the range, so setting @len to 1 is enough to
+		 * get the first chunk.
+		 */
+		em = lookup_extent_mapping(map_tree, start, 1);
+		read_unlock(&map_tree->lock);
+		if (!em)
+			break;
+
+		bg = btrfs_lookup_block_group(fs_info, em->start);
+		if (!bg) {
+			btrfs_err(fs_info,
+	"chunk start=%llu len=%llu doesn't have corresponding block group",
+				     em->start, em->len);
+			ret = -EUCLEAN;
+			free_extent_map(em);
+			break;
+		}
+		if (bg->key.objectid != em->start ||
+		    bg->key.offset != em->len ||
+		    (bg->flags & BTRFS_BLOCK_GROUP_TYPE_MASK) !=
+		    (em->map_lookup->type & BTRFS_BLOCK_GROUP_TYPE_MASK)) {
+			btrfs_err(fs_info,
+"chunk start=%llu len=%llu flags=0x%llx doesn't match block group start=%llu len=%llu flags=0x%llx",
+				em->start, em->len,
+				em->map_lookup->type & BTRFS_BLOCK_GROUP_TYPE_MASK,
+				bg->key.objectid, bg->key.offset,
+				bg->flags & BTRFS_BLOCK_GROUP_TYPE_MASK);
+			ret = -EUCLEAN;
+			free_extent_map(em);
+			btrfs_put_block_group(bg);
+			break;
+		}
+		start = em->start + em->len;
+		free_extent_map(em);
+		btrfs_put_block_group(bg);
+	}
+	return ret;
+}
+
+int btrfs_read_block_groups(struct btrfs_fs_info *info)
+{
+	struct btrfs_path *path;
+	int ret;
+	struct btrfs_block_group_cache *cache;
+	struct btrfs_space_info *space_info;
+	struct btrfs_key key;
+	struct btrfs_key found_key;
+	struct extent_buffer *leaf;
+	int need_clear = 0;
+	u64 cache_gen;
+	u64 feature;
+	int mixed;
+
+	feature = btrfs_super_incompat_flags(info->super_copy);
+	mixed = !!(feature & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS);
+
+	key.objectid = 0;
+	key.offset = 0;
+	key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+	path->reada = READA_FORWARD;
+
+	cache_gen = btrfs_super_cache_generation(info->super_copy);
+	if (btrfs_test_opt(info, SPACE_CACHE) &&
+	    btrfs_super_generation(info->super_copy) != cache_gen)
+		need_clear = 1;
+	if (btrfs_test_opt(info, CLEAR_CACHE))
+		need_clear = 1;
+
+	while (1) {
+		ret = find_first_block_group(info, path, &key);
+		if (ret > 0)
+			break;
+		if (ret != 0)
+			goto error;
+
+		leaf = path->nodes[0];
+		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+
+		cache = btrfs_create_block_group_cache(info, found_key.objectid,
+						       found_key.offset);
+		if (!cache) {
+			ret = -ENOMEM;
+			goto error;
+		}
+
+		if (need_clear) {
+			/*
+			 * When we mount with old space cache, we need to
+			 * set BTRFS_DC_CLEAR and set dirty flag.
+			 *
+			 * a) Setting 'BTRFS_DC_CLEAR' makes sure that we
+			 *    truncate the old free space cache inode and
+			 *    setup a new one.
+			 * b) Setting 'dirty flag' makes sure that we flush
+			 *    the new space cache info onto disk.
+			 */
+			if (btrfs_test_opt(info, SPACE_CACHE))
+				cache->disk_cache_state = BTRFS_DC_CLEAR;
+		}
+
+		read_extent_buffer(leaf, &cache->item,
+				   btrfs_item_ptr_offset(leaf, path->slots[0]),
+				   sizeof(cache->item));
+		cache->flags = btrfs_block_group_flags(&cache->item);
+		if (!mixed &&
+		    ((cache->flags & BTRFS_BLOCK_GROUP_METADATA) &&
+		    (cache->flags & BTRFS_BLOCK_GROUP_DATA))) {
+			btrfs_err(info,
+"bg %llu is a mixed block group but filesystem hasn't enabled mixed block groups",
+				  cache->key.objectid);
+			btrfs_put_block_group(cache);
+			ret = -EINVAL;
+			goto error;
+		}
+
+		key.objectid = found_key.objectid + found_key.offset;
+		btrfs_release_path(path);
+
+		/*
+		 * We need to exclude the super stripes now so that the space
+		 * info has super bytes accounted for, otherwise we'll think
+		 * we have more space than we actually do.
+		 */
+		ret = exclude_super_stripes(cache);
+		if (ret) {
+			/*
+			 * We may have excluded something, so call this just in
+			 * case.
+			 */
+			btrfs_free_excluded_extents(cache);
+			btrfs_put_block_group(cache);
+			goto error;
+		}
+
+		/*
+		 * Check for two cases, either we are full, and therefore
+		 * don't need to bother with the caching work since we won't
+		 * find any space, or we are empty, and we can just add all
+		 * the space in and be done with it.  This saves us _a_lot_ of
+		 * time, particularly in the full case.
+		 */
+		if (found_key.offset == btrfs_block_group_used(&cache->item)) {
+			cache->last_byte_to_unpin = (u64)-1;
+			cache->cached = BTRFS_CACHE_FINISHED;
+			btrfs_free_excluded_extents(cache);
+		} else if (btrfs_block_group_used(&cache->item) == 0) {
+			cache->last_byte_to_unpin = (u64)-1;
+			cache->cached = BTRFS_CACHE_FINISHED;
+			add_new_free_space(cache, found_key.objectid,
+					   found_key.objectid +
+					   found_key.offset);
+			btrfs_free_excluded_extents(cache);
+		}
+
+		ret = btrfs_add_block_group_cache(info, cache);
+		if (ret) {
+			btrfs_remove_free_space_cache(cache);
+			btrfs_put_block_group(cache);
+			goto error;
+		}
+
+		trace_btrfs_add_block_group(info, cache, 0);
+		btrfs_update_space_info(info, cache->flags, found_key.offset,
+					btrfs_block_group_used(&cache->item),
+					cache->bytes_super, &space_info);
+
+		cache->space_info = space_info;
+
+		link_block_group(cache);
+
+		set_avail_alloc_bits(info, cache->flags);
+		if (btrfs_chunk_readonly(info, cache->key.objectid)) {
+			inc_block_group_ro(cache, 1);
+		} else if (btrfs_block_group_used(&cache->item) == 0) {
+			ASSERT(list_empty(&cache->bg_list));
+			btrfs_mark_bg_unused(cache);
+		}
+	}
+
+	list_for_each_entry_rcu(space_info, &info->space_info, list) {
+		if (!(btrfs_get_alloc_profile(info, space_info->flags) &
+		      (BTRFS_BLOCK_GROUP_RAID10 |
+		       BTRFS_BLOCK_GROUP_RAID1_MASK |
+		       BTRFS_BLOCK_GROUP_RAID56_MASK |
+		       BTRFS_BLOCK_GROUP_DUP)))
+			continue;
+		/*
+		 * Avoid allocating from un-mirrored block group if there are
+		 * mirrored block groups.
+		 */
+		list_for_each_entry(cache,
+				&space_info->block_groups[BTRFS_RAID_RAID0],
+				list)
+			inc_block_group_ro(cache, 1);
+		list_for_each_entry(cache,
+				&space_info->block_groups[BTRFS_RAID_SINGLE],
+				list)
+			inc_block_group_ro(cache, 1);
+	}
+
+	btrfs_init_global_block_rsv(info);
+	ret = check_chunk_block_group_mappings(info);
+error:
+	btrfs_free_path(path);
+	return ret;
+}
+
+void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_block_group_cache *block_group;
+	struct btrfs_root *extent_root = fs_info->extent_root;
+	struct btrfs_block_group_item item;
+	struct btrfs_key key;
+	int ret = 0;
+
+	if (!trans->can_flush_pending_bgs)
+		return;
+
+	while (!list_empty(&trans->new_bgs)) {
+		block_group = list_first_entry(&trans->new_bgs,
+					       struct btrfs_block_group_cache,
+					       bg_list);
+		if (ret)
+			goto next;
+
+		spin_lock(&block_group->lock);
+		memcpy(&item, &block_group->item, sizeof(item));
+		memcpy(&key, &block_group->key, sizeof(key));
+		spin_unlock(&block_group->lock);
+
+		ret = btrfs_insert_item(trans, extent_root, &key, &item,
+					sizeof(item));
+		if (ret)
+			btrfs_abort_transaction(trans, ret);
+		ret = btrfs_finish_chunk_alloc(trans, key.objectid, key.offset);
+		if (ret)
+			btrfs_abort_transaction(trans, ret);
+		add_block_group_free_space(trans, block_group);
+		/* Already aborted the transaction if it failed. */
+next:
+		btrfs_delayed_refs_rsv_release(fs_info, 1);
+		list_del_init(&block_group->bg_list);
+	}
+	btrfs_trans_release_chunk_metadata(trans);
+}
+
+int btrfs_make_block_group(struct btrfs_trans_handle *trans, u64 bytes_used,
+			   u64 type, u64 chunk_offset, u64 size)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_block_group_cache *cache;
+	int ret;
+
+	btrfs_set_log_full_commit(trans);
+
+	cache = btrfs_create_block_group_cache(fs_info, chunk_offset, size);
+	if (!cache)
+		return -ENOMEM;
+
+	btrfs_set_block_group_used(&cache->item, bytes_used);
+	btrfs_set_block_group_chunk_objectid(&cache->item,
+					     BTRFS_FIRST_CHUNK_TREE_OBJECTID);
+	btrfs_set_block_group_flags(&cache->item, type);
+
+	cache->flags = type;
+	cache->last_byte_to_unpin = (u64)-1;
+	cache->cached = BTRFS_CACHE_FINISHED;
+	cache->needs_free_space = 1;
+	ret = exclude_super_stripes(cache);
+	if (ret) {
+		/* We may have excluded something, so call this just in case */
+		btrfs_free_excluded_extents(cache);
+		btrfs_put_block_group(cache);
+		return ret;
+	}
+
+	add_new_free_space(cache, chunk_offset, chunk_offset + size);
+
+	btrfs_free_excluded_extents(cache);
+
+#ifdef CONFIG_BTRFS_DEBUG
+	if (btrfs_should_fragment_free_space(cache)) {
+		u64 new_bytes_used = size - bytes_used;
+
+		bytes_used += new_bytes_used >> 1;
+		fragment_free_space(cache);
+	}
+#endif
+	/*
+	 * Ensure the corresponding space_info object is created and
+	 * assigned to our block group. We want our bg to be added to the rbtree
+	 * with its ->space_info set.
+	 */
+	cache->space_info = btrfs_find_space_info(fs_info, cache->flags);
+	ASSERT(cache->space_info);
+
+	ret = btrfs_add_block_group_cache(fs_info, cache);
+	if (ret) {
+		btrfs_remove_free_space_cache(cache);
+		btrfs_put_block_group(cache);
+		return ret;
+	}
+
+	/*
+	 * Now that our block group has its ->space_info set and is inserted in
+	 * the rbtree, update the space info's counters.
+	 */
+	trace_btrfs_add_block_group(fs_info, cache, 1);
+	btrfs_update_space_info(fs_info, cache->flags, size, bytes_used,
+				cache->bytes_super, &cache->space_info);
+	btrfs_update_global_block_rsv(fs_info);
+
+	link_block_group(cache);
+
+	list_add_tail(&cache->bg_list, &trans->new_bgs);
+	trans->delayed_ref_updates++;
+	btrfs_update_delayed_refs_rsv(trans);
+
+	set_avail_alloc_bits(fs_info, type);
+	return 0;
+}
+
+static u64 update_block_group_flags(struct btrfs_fs_info *fs_info, u64 flags)
+{
+	u64 num_devices;
+	u64 stripped;
+
+	/*
+	 * if restripe for this chunk_type is on pick target profile and
+	 * return, otherwise do the usual balance
+	 */
+	stripped = get_restripe_target(fs_info, flags);
+	if (stripped)
+		return extended_to_chunk(stripped);
+
+	num_devices = fs_info->fs_devices->rw_devices;
+
+	stripped = BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID56_MASK |
+		BTRFS_BLOCK_GROUP_RAID1_MASK | BTRFS_BLOCK_GROUP_RAID10;
+
+	if (num_devices == 1) {
+		stripped |= BTRFS_BLOCK_GROUP_DUP;
+		stripped = flags & ~stripped;
+
+		/* turn raid0 into single device chunks */
+		if (flags & BTRFS_BLOCK_GROUP_RAID0)
+			return stripped;
+
+		/* turn mirroring into duplication */
+		if (flags & (BTRFS_BLOCK_GROUP_RAID1_MASK |
+			     BTRFS_BLOCK_GROUP_RAID10))
+			return stripped | BTRFS_BLOCK_GROUP_DUP;
+	} else {
+		/* they already had raid on here, just return */
+		if (flags & stripped)
+			return flags;
+
+		stripped |= BTRFS_BLOCK_GROUP_DUP;
+		stripped = flags & ~stripped;
+
+		/* switch duplicated blocks with raid1 */
+		if (flags & BTRFS_BLOCK_GROUP_DUP)
+			return stripped | BTRFS_BLOCK_GROUP_RAID1;
+
+		/* this is drive concat, leave it alone */
+	}
+
+	return flags;
+}
+
+int btrfs_inc_block_group_ro(struct btrfs_block_group_cache *cache)
+
+{
+	struct btrfs_fs_info *fs_info = cache->fs_info;
+	struct btrfs_trans_handle *trans;
+	u64 alloc_flags;
+	int ret;
+
+again:
+	trans = btrfs_join_transaction(fs_info->extent_root);
+	if (IS_ERR(trans))
+		return PTR_ERR(trans);
+
+	/*
+	 * we're not allowed to set block groups readonly after the dirty
+	 * block groups cache has started writing.  If it already started,
+	 * back off and let this transaction commit
+	 */
+	mutex_lock(&fs_info->ro_block_group_mutex);
+	if (test_bit(BTRFS_TRANS_DIRTY_BG_RUN, &trans->transaction->flags)) {
+		u64 transid = trans->transid;
+
+		mutex_unlock(&fs_info->ro_block_group_mutex);
+		btrfs_end_transaction(trans);
+
+		ret = btrfs_wait_for_commit(fs_info, transid);
+		if (ret)
+			return ret;
+		goto again;
+	}
+
+	/*
+	 * if we are changing raid levels, try to allocate a corresponding
+	 * block group with the new raid level.
+	 */
+	alloc_flags = update_block_group_flags(fs_info, cache->flags);
+	if (alloc_flags != cache->flags) {
+		ret = btrfs_chunk_alloc(trans, alloc_flags, CHUNK_ALLOC_FORCE);
+		/*
+		 * ENOSPC is allowed here, we may have enough space
+		 * already allocated at the new raid level to
+		 * carry on
+		 */
+		if (ret == -ENOSPC)
+			ret = 0;
+		if (ret < 0)
+			goto out;
+	}
+
+	ret = inc_block_group_ro(cache, 0);
+	if (!ret)
+		goto out;
+	alloc_flags = btrfs_get_alloc_profile(fs_info, cache->space_info->flags);
+	ret = btrfs_chunk_alloc(trans, alloc_flags, CHUNK_ALLOC_FORCE);
+	if (ret < 0)
+		goto out;
+	ret = inc_block_group_ro(cache, 0);
+out:
+	if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
+		alloc_flags = update_block_group_flags(fs_info, cache->flags);
+		mutex_lock(&fs_info->chunk_mutex);
+		check_system_chunk(trans, alloc_flags);
+		mutex_unlock(&fs_info->chunk_mutex);
+	}
+	mutex_unlock(&fs_info->ro_block_group_mutex);
+
+	btrfs_end_transaction(trans);
+	return ret;
+}
+
+void btrfs_dec_block_group_ro(struct btrfs_block_group_cache *cache)
+{
+	struct btrfs_space_info *sinfo = cache->space_info;
+	u64 num_bytes;
+
+	BUG_ON(!cache->ro);
+
+	spin_lock(&sinfo->lock);
+	spin_lock(&cache->lock);
+	if (!--cache->ro) {
+		num_bytes = cache->key.offset - cache->reserved -
+			    cache->pinned - cache->bytes_super -
+			    btrfs_block_group_used(&cache->item);
+		sinfo->bytes_readonly -= num_bytes;
+		list_del_init(&cache->ro_list);
+	}
+	spin_unlock(&cache->lock);
+	spin_unlock(&sinfo->lock);
+}
+
+static int write_one_cache_group(struct btrfs_trans_handle *trans,
+				 struct btrfs_path *path,
+				 struct btrfs_block_group_cache *cache)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	int ret;
+	struct btrfs_root *extent_root = fs_info->extent_root;
+	unsigned long bi;
+	struct extent_buffer *leaf;
+
+	ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
+	if (ret) {
+		if (ret > 0)
+			ret = -ENOENT;
+		goto fail;
+	}
+
+	leaf = path->nodes[0];
+	bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
+	write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
+	btrfs_mark_buffer_dirty(leaf);
+fail:
+	btrfs_release_path(path);
+	return ret;
+
+}
+
+static int cache_save_setup(struct btrfs_block_group_cache *block_group,
+			    struct btrfs_trans_handle *trans,
+			    struct btrfs_path *path)
+{
+	struct btrfs_fs_info *fs_info = block_group->fs_info;
+	struct btrfs_root *root = fs_info->tree_root;
+	struct inode *inode = NULL;
+	struct extent_changeset *data_reserved = NULL;
+	u64 alloc_hint = 0;
+	int dcs = BTRFS_DC_ERROR;
+	u64 num_pages = 0;
+	int retries = 0;
+	int ret = 0;
+
+	/*
+	 * If this block group is smaller than 100 megs don't bother caching the
+	 * block group.
+	 */
+	if (block_group->key.offset < (100 * SZ_1M)) {
+		spin_lock(&block_group->lock);
+		block_group->disk_cache_state = BTRFS_DC_WRITTEN;
+		spin_unlock(&block_group->lock);
+		return 0;
+	}
+
+	if (trans->aborted)
+		return 0;
+again:
+	inode = lookup_free_space_inode(block_group, path);
+	if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) {
+		ret = PTR_ERR(inode);
+		btrfs_release_path(path);
+		goto out;
+	}
+
+	if (IS_ERR(inode)) {
+		BUG_ON(retries);
+		retries++;
+
+		if (block_group->ro)
+			goto out_free;
+
+		ret = create_free_space_inode(trans, block_group, path);
+		if (ret)
+			goto out_free;
+		goto again;
+	}
+
+	/*
+	 * We want to set the generation to 0, that way if anything goes wrong
+	 * from here on out we know not to trust this cache when we load up next
+	 * time.
+	 */
+	BTRFS_I(inode)->generation = 0;
+	ret = btrfs_update_inode(trans, root, inode);
+	if (ret) {
+		/*
+		 * So theoretically we could recover from this, simply set the
+		 * super cache generation to 0 so we know to invalidate the
+		 * cache, but then we'd have to keep track of the block groups
+		 * that fail this way so we know we _have_ to reset this cache
+		 * before the next commit or risk reading stale cache.  So to
+		 * limit our exposure to horrible edge cases lets just abort the
+		 * transaction, this only happens in really bad situations
+		 * anyway.
+		 */
+		btrfs_abort_transaction(trans, ret);
+		goto out_put;
+	}
+	WARN_ON(ret);
+
+	/* We've already setup this transaction, go ahead and exit */
+	if (block_group->cache_generation == trans->transid &&
+	    i_size_read(inode)) {
+		dcs = BTRFS_DC_SETUP;
+		goto out_put;
+	}
+
+	if (i_size_read(inode) > 0) {
+		ret = btrfs_check_trunc_cache_free_space(fs_info,
+					&fs_info->global_block_rsv);
+		if (ret)
+			goto out_put;
+
+		ret = btrfs_truncate_free_space_cache(trans, NULL, inode);
+		if (ret)
+			goto out_put;
+	}
+
+	spin_lock(&block_group->lock);
+	if (block_group->cached != BTRFS_CACHE_FINISHED ||
+	    !btrfs_test_opt(fs_info, SPACE_CACHE)) {
+		/*
+		 * don't bother trying to write stuff out _if_
+		 * a) we're not cached,
+		 * b) we're with nospace_cache mount option,
+		 * c) we're with v2 space_cache (FREE_SPACE_TREE).
+		 */
+		dcs = BTRFS_DC_WRITTEN;
+		spin_unlock(&block_group->lock);
+		goto out_put;
+	}
+	spin_unlock(&block_group->lock);
+
+	/*
+	 * We hit an ENOSPC when setting up the cache in this transaction, just
+	 * skip doing the setup, we've already cleared the cache so we're safe.
+	 */
+	if (test_bit(BTRFS_TRANS_CACHE_ENOSPC, &trans->transaction->flags)) {
+		ret = -ENOSPC;
+		goto out_put;
+	}
+
+	/*
+	 * Try to preallocate enough space based on how big the block group is.
+	 * Keep in mind this has to include any pinned space which could end up
+	 * taking up quite a bit since it's not folded into the other space
+	 * cache.
+	 */
+	num_pages = div_u64(block_group->key.offset, SZ_256M);
+	if (!num_pages)
+		num_pages = 1;
+
+	num_pages *= 16;
+	num_pages *= PAGE_SIZE;
+
+	ret = btrfs_check_data_free_space(inode, &data_reserved, 0, num_pages);
+	if (ret)
+		goto out_put;
+
+	ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, num_pages,
+					      num_pages, num_pages,
+					      &alloc_hint);
+	/*
+	 * Our cache requires contiguous chunks so that we don't modify a bunch
+	 * of metadata or split extents when writing the cache out, which means
+	 * we can enospc if we are heavily fragmented in addition to just normal
+	 * out of space conditions.  So if we hit this just skip setting up any
+	 * other block groups for this transaction, maybe we'll unpin enough
+	 * space the next time around.
+	 */
+	if (!ret)
+		dcs = BTRFS_DC_SETUP;
+	else if (ret == -ENOSPC)
+		set_bit(BTRFS_TRANS_CACHE_ENOSPC, &trans->transaction->flags);
+
+out_put:
+	iput(inode);
+out_free:
+	btrfs_release_path(path);
+out:
+	spin_lock(&block_group->lock);
+	if (!ret && dcs == BTRFS_DC_SETUP)
+		block_group->cache_generation = trans->transid;
+	block_group->disk_cache_state = dcs;
+	spin_unlock(&block_group->lock);
+
+	extent_changeset_free(data_reserved);
+	return ret;
+}
+
+int btrfs_setup_space_cache(struct btrfs_trans_handle *trans)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_block_group_cache *cache, *tmp;
+	struct btrfs_transaction *cur_trans = trans->transaction;
+	struct btrfs_path *path;
+
+	if (list_empty(&cur_trans->dirty_bgs) ||
+	    !btrfs_test_opt(fs_info, SPACE_CACHE))
+		return 0;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	/* Could add new block groups, use _safe just in case */
+	list_for_each_entry_safe(cache, tmp, &cur_trans->dirty_bgs,
+				 dirty_list) {
+		if (cache->disk_cache_state == BTRFS_DC_CLEAR)
+			cache_save_setup(cache, trans, path);
+	}
+
+	btrfs_free_path(path);
+	return 0;
+}
+
+/*
+ * Transaction commit does final block group cache writeback during a critical
+ * section where nothing is allowed to change the FS.  This is required in
+ * order for the cache to actually match the block group, but can introduce a
+ * lot of latency into the commit.
+ *
+ * So, btrfs_start_dirty_block_groups is here to kick off block group cache IO.
+ * There's a chance we'll have to redo some of it if the block group changes
+ * again during the commit, but it greatly reduces the commit latency by
+ * getting rid of the easy block groups while we're still allowing others to
+ * join the commit.
+ */
+int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_block_group_cache *cache;
+	struct btrfs_transaction *cur_trans = trans->transaction;
+	int ret = 0;
+	int should_put;
+	struct btrfs_path *path = NULL;
+	LIST_HEAD(dirty);
+	struct list_head *io = &cur_trans->io_bgs;
+	int num_started = 0;
+	int loops = 0;
+
+	spin_lock(&cur_trans->dirty_bgs_lock);
+	if (list_empty(&cur_trans->dirty_bgs)) {
+		spin_unlock(&cur_trans->dirty_bgs_lock);
+		return 0;
+	}
+	list_splice_init(&cur_trans->dirty_bgs, &dirty);
+	spin_unlock(&cur_trans->dirty_bgs_lock);
+
+again:
+	/* Make sure all the block groups on our dirty list actually exist */
+	btrfs_create_pending_block_groups(trans);
+
+	if (!path) {
+		path = btrfs_alloc_path();
+		if (!path)
+			return -ENOMEM;
+	}
+
+	/*
+	 * cache_write_mutex is here only to save us from balance or automatic
+	 * removal of empty block groups deleting this block group while we are
+	 * writing out the cache
+	 */
+	mutex_lock(&trans->transaction->cache_write_mutex);
+	while (!list_empty(&dirty)) {
+		bool drop_reserve = true;
+
+		cache = list_first_entry(&dirty,
+					 struct btrfs_block_group_cache,
+					 dirty_list);
+		/*
+		 * This can happen if something re-dirties a block group that
+		 * is already under IO.  Just wait for it to finish and then do
+		 * it all again
+		 */
+		if (!list_empty(&cache->io_list)) {
+			list_del_init(&cache->io_list);
+			btrfs_wait_cache_io(trans, cache, path);
+			btrfs_put_block_group(cache);
+		}
+
+
+		/*
+		 * btrfs_wait_cache_io uses the cache->dirty_list to decide if
+		 * it should update the cache_state.  Don't delete until after
+		 * we wait.
+		 *
+		 * Since we're not running in the commit critical section
+		 * we need the dirty_bgs_lock to protect from update_block_group
+		 */
+		spin_lock(&cur_trans->dirty_bgs_lock);
+		list_del_init(&cache->dirty_list);
+		spin_unlock(&cur_trans->dirty_bgs_lock);
+
+		should_put = 1;
+
+		cache_save_setup(cache, trans, path);
+
+		if (cache->disk_cache_state == BTRFS_DC_SETUP) {
+			cache->io_ctl.inode = NULL;
+			ret = btrfs_write_out_cache(trans, cache, path);
+			if (ret == 0 && cache->io_ctl.inode) {
+				num_started++;
+				should_put = 0;
+
+				/*
+				 * The cache_write_mutex is protecting the
+				 * io_list, also refer to the definition of
+				 * btrfs_transaction::io_bgs for more details
+				 */
+				list_add_tail(&cache->io_list, io);
+			} else {
+				/*
+				 * If we failed to write the cache, the
+				 * generation will be bad and life goes on
+				 */
+				ret = 0;
+			}
+		}
+		if (!ret) {
+			ret = write_one_cache_group(trans, path, cache);
+			/*
+			 * Our block group might still be attached to the list
+			 * of new block groups in the transaction handle of some
+			 * other task (struct btrfs_trans_handle->new_bgs). This
+			 * means its block group item isn't yet in the extent
+			 * tree. If this happens ignore the error, as we will
+			 * try again later in the critical section of the
+			 * transaction commit.
+			 */
+			if (ret == -ENOENT) {
+				ret = 0;
+				spin_lock(&cur_trans->dirty_bgs_lock);
+				if (list_empty(&cache->dirty_list)) {
+					list_add_tail(&cache->dirty_list,
+						      &cur_trans->dirty_bgs);
+					btrfs_get_block_group(cache);
+					drop_reserve = false;
+				}
+				spin_unlock(&cur_trans->dirty_bgs_lock);
+			} else if (ret) {
+				btrfs_abort_transaction(trans, ret);
+			}
+		}
+
+		/* If it's not on the io list, we need to put the block group */
+		if (should_put)
+			btrfs_put_block_group(cache);
+		if (drop_reserve)
+			btrfs_delayed_refs_rsv_release(fs_info, 1);
+
+		if (ret)
+			break;
+
+		/*
+		 * Avoid blocking other tasks for too long. It might even save
+		 * us from writing caches for block groups that are going to be
+		 * removed.
+		 */
+		mutex_unlock(&trans->transaction->cache_write_mutex);
+		mutex_lock(&trans->transaction->cache_write_mutex);
+	}
+	mutex_unlock(&trans->transaction->cache_write_mutex);
+
+	/*
+	 * Go through delayed refs for all the stuff we've just kicked off
+	 * and then loop back (just once)
+	 */
+	ret = btrfs_run_delayed_refs(trans, 0);
+	if (!ret && loops == 0) {
+		loops++;
+		spin_lock(&cur_trans->dirty_bgs_lock);
+		list_splice_init(&cur_trans->dirty_bgs, &dirty);
+		/*
+		 * dirty_bgs_lock protects us from concurrent block group
+		 * deletes too (not just cache_write_mutex).
+		 */
+		if (!list_empty(&dirty)) {
+			spin_unlock(&cur_trans->dirty_bgs_lock);
+			goto again;
+		}
+		spin_unlock(&cur_trans->dirty_bgs_lock);
+	} else if (ret < 0) {
+		btrfs_cleanup_dirty_bgs(cur_trans, fs_info);
+	}
+
+	btrfs_free_path(path);
+	return ret;
+}
+
+int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_block_group_cache *cache;
+	struct btrfs_transaction *cur_trans = trans->transaction;
+	int ret = 0;
+	int should_put;
+	struct btrfs_path *path;
+	struct list_head *io = &cur_trans->io_bgs;
+	int num_started = 0;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	/*
+	 * Even though we are in the critical section of the transaction commit,
+	 * we can still have concurrent tasks adding elements to this
+	 * transaction's list of dirty block groups. These tasks correspond to
+	 * endio free space workers started when writeback finishes for a
+	 * space cache, which run inode.c:btrfs_finish_ordered_io(), and can
+	 * allocate new block groups as a result of COWing nodes of the root
+	 * tree when updating the free space inode. The writeback for the space
+	 * caches is triggered by an earlier call to
+	 * btrfs_start_dirty_block_groups() and iterations of the following
+	 * loop.
+	 * Also we want to do the cache_save_setup first and then run the
+	 * delayed refs to make sure we have the best chance at doing this all
+	 * in one shot.
+	 */
+	spin_lock(&cur_trans->dirty_bgs_lock);
+	while (!list_empty(&cur_trans->dirty_bgs)) {
+		cache = list_first_entry(&cur_trans->dirty_bgs,
+					 struct btrfs_block_group_cache,
+					 dirty_list);
+
+		/*
+		 * This can happen if cache_save_setup re-dirties a block group
+		 * that is already under IO.  Just wait for it to finish and
+		 * then do it all again
+		 */
+		if (!list_empty(&cache->io_list)) {
+			spin_unlock(&cur_trans->dirty_bgs_lock);
+			list_del_init(&cache->io_list);
+			btrfs_wait_cache_io(trans, cache, path);
+			btrfs_put_block_group(cache);
+			spin_lock(&cur_trans->dirty_bgs_lock);
+		}
+
+		/*
+		 * Don't remove from the dirty list until after we've waited on
+		 * any pending IO
+		 */
+		list_del_init(&cache->dirty_list);
+		spin_unlock(&cur_trans->dirty_bgs_lock);
+		should_put = 1;
+
+		cache_save_setup(cache, trans, path);
+
+		if (!ret)
+			ret = btrfs_run_delayed_refs(trans,
+						     (unsigned long) -1);
+
+		if (!ret && cache->disk_cache_state == BTRFS_DC_SETUP) {
+			cache->io_ctl.inode = NULL;
+			ret = btrfs_write_out_cache(trans, cache, path);
+			if (ret == 0 && cache->io_ctl.inode) {
+				num_started++;
+				should_put = 0;
+				list_add_tail(&cache->io_list, io);
+			} else {
+				/*
+				 * If we failed to write the cache, the
+				 * generation will be bad and life goes on
+				 */
+				ret = 0;
+			}
+		}
+		if (!ret) {
+			ret = write_one_cache_group(trans, path, cache);
+			/*
+			 * One of the free space endio workers might have
+			 * created a new block group while updating a free space
+			 * cache's inode (at inode.c:btrfs_finish_ordered_io())
+			 * and hasn't released its transaction handle yet, in
+			 * which case the new block group is still attached to
+			 * its transaction handle and its creation has not
+			 * finished yet (no block group item in the extent tree
+			 * yet, etc). If this is the case, wait for all free
+			 * space endio workers to finish and retry. This is a
+			 * a very rare case so no need for a more efficient and
+			 * complex approach.
+			 */
+			if (ret == -ENOENT) {
+				wait_event(cur_trans->writer_wait,
+				   atomic_read(&cur_trans->num_writers) == 1);
+				ret = write_one_cache_group(trans, path, cache);
+			}
+			if (ret)
+				btrfs_abort_transaction(trans, ret);
+		}
+
+		/* If its not on the io list, we need to put the block group */
+		if (should_put)
+			btrfs_put_block_group(cache);
+		btrfs_delayed_refs_rsv_release(fs_info, 1);
+		spin_lock(&cur_trans->dirty_bgs_lock);
+	}
+	spin_unlock(&cur_trans->dirty_bgs_lock);
+
+	/*
+	 * Refer to the definition of io_bgs member for details why it's safe
+	 * to use it without any locking
+	 */
+	while (!list_empty(io)) {
+		cache = list_first_entry(io, struct btrfs_block_group_cache,
+					 io_list);
+		list_del_init(&cache->io_list);
+		btrfs_wait_cache_io(trans, cache, path);
+		btrfs_put_block_group(cache);
+	}
+
+	btrfs_free_path(path);
+	return ret;
+}
+
+int btrfs_update_block_group(struct btrfs_trans_handle *trans,
+			     u64 bytenr, u64 num_bytes, int alloc)
+{
+	struct btrfs_fs_info *info = trans->fs_info;
+	struct btrfs_block_group_cache *cache = NULL;
+	u64 total = num_bytes;
+	u64 old_val;
+	u64 byte_in_group;
+	int factor;
+	int ret = 0;
+
+	/* Block accounting for super block */
+	spin_lock(&info->delalloc_root_lock);
+	old_val = btrfs_super_bytes_used(info->super_copy);
+	if (alloc)
+		old_val += num_bytes;
+	else
+		old_val -= num_bytes;
+	btrfs_set_super_bytes_used(info->super_copy, old_val);
+	spin_unlock(&info->delalloc_root_lock);
+
+	while (total) {
+		cache = btrfs_lookup_block_group(info, bytenr);
+		if (!cache) {
+			ret = -ENOENT;
+			break;
+		}
+		factor = btrfs_bg_type_to_factor(cache->flags);
+
+		/*
+		 * If this block group has free space cache written out, we
+		 * need to make sure to load it if we are removing space.  This
+		 * is because we need the unpinning stage to actually add the
+		 * space back to the block group, otherwise we will leak space.
+		 */
+		if (!alloc && cache->cached == BTRFS_CACHE_NO)
+			btrfs_cache_block_group(cache, 1);
+
+		byte_in_group = bytenr - cache->key.objectid;
+		WARN_ON(byte_in_group > cache->key.offset);
+
+		spin_lock(&cache->space_info->lock);
+		spin_lock(&cache->lock);
+
+		if (btrfs_test_opt(info, SPACE_CACHE) &&
+		    cache->disk_cache_state < BTRFS_DC_CLEAR)
+			cache->disk_cache_state = BTRFS_DC_CLEAR;
+
+		old_val = btrfs_block_group_used(&cache->item);
+		num_bytes = min(total, cache->key.offset - byte_in_group);
+		if (alloc) {
+			old_val += num_bytes;
+			btrfs_set_block_group_used(&cache->item, old_val);
+			cache->reserved -= num_bytes;
+			cache->space_info->bytes_reserved -= num_bytes;
+			cache->space_info->bytes_used += num_bytes;
+			cache->space_info->disk_used += num_bytes * factor;
+			spin_unlock(&cache->lock);
+			spin_unlock(&cache->space_info->lock);
+		} else {
+			old_val -= num_bytes;
+			btrfs_set_block_group_used(&cache->item, old_val);
+			cache->pinned += num_bytes;
+			btrfs_space_info_update_bytes_pinned(info,
+					cache->space_info, num_bytes);
+			cache->space_info->bytes_used -= num_bytes;
+			cache->space_info->disk_used -= num_bytes * factor;
+			spin_unlock(&cache->lock);
+			spin_unlock(&cache->space_info->lock);
+
+			percpu_counter_add_batch(
+					&cache->space_info->total_bytes_pinned,
+					num_bytes,
+					BTRFS_TOTAL_BYTES_PINNED_BATCH);
+			set_extent_dirty(info->pinned_extents,
+					 bytenr, bytenr + num_bytes - 1,
+					 GFP_NOFS | __GFP_NOFAIL);
+		}
+
+		spin_lock(&trans->transaction->dirty_bgs_lock);
+		if (list_empty(&cache->dirty_list)) {
+			list_add_tail(&cache->dirty_list,
+				      &trans->transaction->dirty_bgs);
+			trans->delayed_ref_updates++;
+			btrfs_get_block_group(cache);
+		}
+		spin_unlock(&trans->transaction->dirty_bgs_lock);
+
+		/*
+		 * No longer have used bytes in this block group, queue it for
+		 * deletion. We do this after adding the block group to the
+		 * dirty list to avoid races between cleaner kthread and space
+		 * cache writeout.
+		 */
+		if (!alloc && old_val == 0)
+			btrfs_mark_bg_unused(cache);
+
+		btrfs_put_block_group(cache);
+		total -= num_bytes;
+		bytenr += num_bytes;
+	}
+
+	/* Modified block groups are accounted for in the delayed_refs_rsv. */
+	btrfs_update_delayed_refs_rsv(trans);
+	return ret;
+}
+
+/**
+ * btrfs_add_reserved_bytes - update the block_group and space info counters
+ * @cache:	The cache we are manipulating
+ * @ram_bytes:  The number of bytes of file content, and will be same to
+ *              @num_bytes except for the compress path.
+ * @num_bytes:	The number of bytes in question
+ * @delalloc:   The blocks are allocated for the delalloc write
+ *
+ * This is called by the allocator when it reserves space. If this is a
+ * reservation and the block group has become read only we cannot make the
+ * reservation and return -EAGAIN, otherwise this function always succeeds.
+ */
+int btrfs_add_reserved_bytes(struct btrfs_block_group_cache *cache,
+			     u64 ram_bytes, u64 num_bytes, int delalloc)
+{
+	struct btrfs_space_info *space_info = cache->space_info;
+	int ret = 0;
+
+	spin_lock(&space_info->lock);
+	spin_lock(&cache->lock);
+	if (cache->ro) {
+		ret = -EAGAIN;
+	} else {
+		cache->reserved += num_bytes;
+		space_info->bytes_reserved += num_bytes;
+		trace_btrfs_space_reservation(cache->fs_info, "space_info",
+					      space_info->flags, num_bytes, 1);
+		btrfs_space_info_update_bytes_may_use(cache->fs_info,
+						      space_info, -ram_bytes);
+		if (delalloc)
+			cache->delalloc_bytes += num_bytes;
+	}
+	spin_unlock(&cache->lock);
+	spin_unlock(&space_info->lock);
+	return ret;
+}
+
+/**
+ * btrfs_free_reserved_bytes - update the block_group and space info counters
+ * @cache:      The cache we are manipulating
+ * @num_bytes:  The number of bytes in question
+ * @delalloc:   The blocks are allocated for the delalloc write
+ *
+ * This is called by somebody who is freeing space that was never actually used
+ * on disk.  For example if you reserve some space for a new leaf in transaction
+ * A and before transaction A commits you free that leaf, you call this with
+ * reserve set to 0 in order to clear the reservation.
+ */
+void btrfs_free_reserved_bytes(struct btrfs_block_group_cache *cache,
+			       u64 num_bytes, int delalloc)
+{
+	struct btrfs_space_info *space_info = cache->space_info;
+
+	spin_lock(&space_info->lock);
+	spin_lock(&cache->lock);
+	if (cache->ro)
+		space_info->bytes_readonly += num_bytes;
+	cache->reserved -= num_bytes;
+	space_info->bytes_reserved -= num_bytes;
+	space_info->max_extent_size = 0;
+
+	if (delalloc)
+		cache->delalloc_bytes -= num_bytes;
+	spin_unlock(&cache->lock);
+	spin_unlock(&space_info->lock);
+}
+
+static void force_metadata_allocation(struct btrfs_fs_info *info)
+{
+	struct list_head *head = &info->space_info;
+	struct btrfs_space_info *found;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(found, head, list) {
+		if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
+			found->force_alloc = CHUNK_ALLOC_FORCE;
+	}
+	rcu_read_unlock();
+}
+
+static int should_alloc_chunk(struct btrfs_fs_info *fs_info,
+			      struct btrfs_space_info *sinfo, int force)
+{
+	u64 bytes_used = btrfs_space_info_used(sinfo, false);
+	u64 thresh;
+
+	if (force == CHUNK_ALLOC_FORCE)
+		return 1;
+
+	/*
+	 * in limited mode, we want to have some free space up to
+	 * about 1% of the FS size.
+	 */
+	if (force == CHUNK_ALLOC_LIMITED) {
+		thresh = btrfs_super_total_bytes(fs_info->super_copy);
+		thresh = max_t(u64, SZ_64M, div_factor_fine(thresh, 1));
+
+		if (sinfo->total_bytes - bytes_used < thresh)
+			return 1;
+	}
+
+	if (bytes_used + SZ_2M < div_factor(sinfo->total_bytes, 8))
+		return 0;
+	return 1;
+}
+
+int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, u64 type)
+{
+	u64 alloc_flags = btrfs_get_alloc_profile(trans->fs_info, type);
+
+	return btrfs_chunk_alloc(trans, alloc_flags, CHUNK_ALLOC_FORCE);
+}
+
+/*
+ * If force is CHUNK_ALLOC_FORCE:
+ *    - return 1 if it successfully allocates a chunk,
+ *    - return errors including -ENOSPC otherwise.
+ * If force is NOT CHUNK_ALLOC_FORCE:
+ *    - return 0 if it doesn't need to allocate a new chunk,
+ *    - return 1 if it successfully allocates a chunk,
+ *    - return errors including -ENOSPC otherwise.
+ */
+int btrfs_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags,
+		      enum btrfs_chunk_alloc_enum force)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_space_info *space_info;
+	bool wait_for_alloc = false;
+	bool should_alloc = false;
+	int ret = 0;
+
+	/* Don't re-enter if we're already allocating a chunk */
+	if (trans->allocating_chunk)
+		return -ENOSPC;
+
+	space_info = btrfs_find_space_info(fs_info, flags);
+	ASSERT(space_info);
+
+	do {
+		spin_lock(&space_info->lock);
+		if (force < space_info->force_alloc)
+			force = space_info->force_alloc;
+		should_alloc = should_alloc_chunk(fs_info, space_info, force);
+		if (space_info->full) {
+			/* No more free physical space */
+			if (should_alloc)
+				ret = -ENOSPC;
+			else
+				ret = 0;
+			spin_unlock(&space_info->lock);
+			return ret;
+		} else if (!should_alloc) {
+			spin_unlock(&space_info->lock);
+			return 0;
+		} else if (space_info->chunk_alloc) {
+			/*
+			 * Someone is already allocating, so we need to block
+			 * until this someone is finished and then loop to
+			 * recheck if we should continue with our allocation
+			 * attempt.
+			 */
+			wait_for_alloc = true;
+			spin_unlock(&space_info->lock);
+			mutex_lock(&fs_info->chunk_mutex);
+			mutex_unlock(&fs_info->chunk_mutex);
+		} else {
+			/* Proceed with allocation */
+			space_info->chunk_alloc = 1;
+			wait_for_alloc = false;
+			spin_unlock(&space_info->lock);
+		}
+
+		cond_resched();
+	} while (wait_for_alloc);
+
+	mutex_lock(&fs_info->chunk_mutex);
+	trans->allocating_chunk = true;
+
+	/*
+	 * If we have mixed data/metadata chunks we want to make sure we keep
+	 * allocating mixed chunks instead of individual chunks.
+	 */
+	if (btrfs_mixed_space_info(space_info))
+		flags |= (BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA);
+
+	/*
+	 * if we're doing a data chunk, go ahead and make sure that
+	 * we keep a reasonable number of metadata chunks allocated in the
+	 * FS as well.
+	 */
+	if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) {
+		fs_info->data_chunk_allocations++;
+		if (!(fs_info->data_chunk_allocations %
+		      fs_info->metadata_ratio))
+			force_metadata_allocation(fs_info);
+	}
+
+	/*
+	 * Check if we have enough space in SYSTEM chunk because we may need
+	 * to update devices.
+	 */
+	check_system_chunk(trans, flags);
+
+	ret = btrfs_alloc_chunk(trans, flags);
+	trans->allocating_chunk = false;
+
+	spin_lock(&space_info->lock);
+	if (ret < 0) {
+		if (ret == -ENOSPC)
+			space_info->full = 1;
+		else
+			goto out;
+	} else {
+		ret = 1;
+		space_info->max_extent_size = 0;
+	}
+
+	space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
+out:
+	space_info->chunk_alloc = 0;
+	spin_unlock(&space_info->lock);
+	mutex_unlock(&fs_info->chunk_mutex);
+	/*
+	 * When we allocate a new chunk we reserve space in the chunk block
+	 * reserve to make sure we can COW nodes/leafs in the chunk tree or
+	 * add new nodes/leafs to it if we end up needing to do it when
+	 * inserting the chunk item and updating device items as part of the
+	 * second phase of chunk allocation, performed by
+	 * btrfs_finish_chunk_alloc(). So make sure we don't accumulate a
+	 * large number of new block groups to create in our transaction
+	 * handle's new_bgs list to avoid exhausting the chunk block reserve
+	 * in extreme cases - like having a single transaction create many new
+	 * block groups when starting to write out the free space caches of all
+	 * the block groups that were made dirty during the lifetime of the
+	 * transaction.
+	 */
+	if (trans->chunk_bytes_reserved >= (u64)SZ_2M)
+		btrfs_create_pending_block_groups(trans);
+
+	return ret;
+}
+
+static u64 get_profile_num_devs(struct btrfs_fs_info *fs_info, u64 type)
+{
+	u64 num_dev;
+
+	num_dev = btrfs_raid_array[btrfs_bg_flags_to_raid_index(type)].devs_max;
+	if (!num_dev)
+		num_dev = fs_info->fs_devices->rw_devices;
+
+	return num_dev;
+}
+
+/*
+ * If @is_allocation is true, reserve space in the system space info necessary
+ * for allocating a chunk, otherwise if it's false, reserve space necessary for
+ * removing a chunk.
+ */
+void check_system_chunk(struct btrfs_trans_handle *trans, u64 type)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_space_info *info;
+	u64 left;
+	u64 thresh;
+	int ret = 0;
+	u64 num_devs;
+
+	/*
+	 * Needed because we can end up allocating a system chunk and for an
+	 * atomic and race free space reservation in the chunk block reserve.
+	 */
+	lockdep_assert_held(&fs_info->chunk_mutex);
+
+	info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
+	spin_lock(&info->lock);
+	left = info->total_bytes - btrfs_space_info_used(info, true);
+	spin_unlock(&info->lock);
+
+	num_devs = get_profile_num_devs(fs_info, type);
+
+	/* num_devs device items to update and 1 chunk item to add or remove */
+	thresh = btrfs_calc_metadata_size(fs_info, num_devs) +
+		btrfs_calc_insert_metadata_size(fs_info, 1);
+
+	if (left < thresh && btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
+		btrfs_info(fs_info, "left=%llu, need=%llu, flags=%llu",
+			   left, thresh, type);
+		btrfs_dump_space_info(fs_info, info, 0, 0);
+	}
+
+	if (left < thresh) {
+		u64 flags = btrfs_system_alloc_profile(fs_info);
+
+		/*
+		 * Ignore failure to create system chunk. We might end up not
+		 * needing it, as we might not need to COW all nodes/leafs from
+		 * the paths we visit in the chunk tree (they were already COWed
+		 * or created in the current transaction for example).
+		 */
+		ret = btrfs_alloc_chunk(trans, flags);
+	}
+
+	if (!ret) {
+		ret = btrfs_block_rsv_add(fs_info->chunk_root,
+					  &fs_info->chunk_block_rsv,
+					  thresh, BTRFS_RESERVE_NO_FLUSH);
+		if (!ret)
+			trans->chunk_bytes_reserved += thresh;
+	}
+}
+
+void btrfs_put_block_group_cache(struct btrfs_fs_info *info)
+{
+	struct btrfs_block_group_cache *block_group;
+	u64 last = 0;
+
+	while (1) {
+		struct inode *inode;
+
+		block_group = btrfs_lookup_first_block_group(info, last);
+		while (block_group) {
+			btrfs_wait_block_group_cache_done(block_group);
+			spin_lock(&block_group->lock);
+			if (block_group->iref)
+				break;
+			spin_unlock(&block_group->lock);
+			block_group = btrfs_next_block_group(block_group);
+		}
+		if (!block_group) {
+			if (last == 0)
+				break;
+			last = 0;
+			continue;
+		}
+
+		inode = block_group->inode;
+		block_group->iref = 0;
+		block_group->inode = NULL;
+		spin_unlock(&block_group->lock);
+		ASSERT(block_group->io_ctl.inode == NULL);
+		iput(inode);
+		last = block_group->key.objectid + block_group->key.offset;
+		btrfs_put_block_group(block_group);
+	}
+}
+
+/*
+ * Must be called only after stopping all workers, since we could have block
+ * group caching kthreads running, and therefore they could race with us if we
+ * freed the block groups before stopping them.
+ */
+int btrfs_free_block_groups(struct btrfs_fs_info *info)
+{
+	struct btrfs_block_group_cache *block_group;
+	struct btrfs_space_info *space_info;
+	struct btrfs_caching_control *caching_ctl;
+	struct rb_node *n;
+
+	down_write(&info->commit_root_sem);
+	while (!list_empty(&info->caching_block_groups)) {
+		caching_ctl = list_entry(info->caching_block_groups.next,
+					 struct btrfs_caching_control, list);
+		list_del(&caching_ctl->list);
+		btrfs_put_caching_control(caching_ctl);
+	}
+	up_write(&info->commit_root_sem);
+
+	spin_lock(&info->unused_bgs_lock);
+	while (!list_empty(&info->unused_bgs)) {
+		block_group = list_first_entry(&info->unused_bgs,
+					       struct btrfs_block_group_cache,
+					       bg_list);
+		list_del_init(&block_group->bg_list);
+		btrfs_put_block_group(block_group);
+	}
+	spin_unlock(&info->unused_bgs_lock);
+
+	spin_lock(&info->block_group_cache_lock);
+	while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
+		block_group = rb_entry(n, struct btrfs_block_group_cache,
+				       cache_node);
+		rb_erase(&block_group->cache_node,
+			 &info->block_group_cache_tree);
+		RB_CLEAR_NODE(&block_group->cache_node);
+		spin_unlock(&info->block_group_cache_lock);
+
+		down_write(&block_group->space_info->groups_sem);
+		list_del(&block_group->list);
+		up_write(&block_group->space_info->groups_sem);
+
+		/*
+		 * We haven't cached this block group, which means we could
+		 * possibly have excluded extents on this block group.
+		 */
+		if (block_group->cached == BTRFS_CACHE_NO ||
+		    block_group->cached == BTRFS_CACHE_ERROR)
+			btrfs_free_excluded_extents(block_group);
+
+		btrfs_remove_free_space_cache(block_group);
+		ASSERT(block_group->cached != BTRFS_CACHE_STARTED);
+		ASSERT(list_empty(&block_group->dirty_list));
+		ASSERT(list_empty(&block_group->io_list));
+		ASSERT(list_empty(&block_group->bg_list));
+		ASSERT(atomic_read(&block_group->count) == 1);
+		btrfs_put_block_group(block_group);
+
+		spin_lock(&info->block_group_cache_lock);
+	}
+	spin_unlock(&info->block_group_cache_lock);
+
+	/*
+	 * Now that all the block groups are freed, go through and free all the
+	 * space_info structs.  This is only called during the final stages of
+	 * unmount, and so we know nobody is using them.  We call
+	 * synchronize_rcu() once before we start, just to be on the safe side.
+	 */
+	synchronize_rcu();
+
+	btrfs_release_global_block_rsv(info);
+
+	while (!list_empty(&info->space_info)) {
+		space_info = list_entry(info->space_info.next,
+					struct btrfs_space_info,
+					list);
+
+		/*
+		 * Do not hide this behind enospc_debug, this is actually
+		 * important and indicates a real bug if this happens.
+		 */
+		if (WARN_ON(space_info->bytes_pinned > 0 ||
+			    space_info->bytes_reserved > 0 ||
+			    space_info->bytes_may_use > 0))
+			btrfs_dump_space_info(info, space_info, 0, 0);
+		list_del(&space_info->list);
+		btrfs_sysfs_remove_space_info(space_info);
+	}
+	return 0;
+}
diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
new file mode 100644
index 0000000..c391800
--- /dev/null
+++ b/fs/btrfs/block-group.h
@@ -0,0 +1,250 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef BTRFS_BLOCK_GROUP_H
+#define BTRFS_BLOCK_GROUP_H
+
+#include "free-space-cache.h"
+
+enum btrfs_disk_cache_state {
+	BTRFS_DC_WRITTEN,
+	BTRFS_DC_ERROR,
+	BTRFS_DC_CLEAR,
+	BTRFS_DC_SETUP,
+};
+
+/*
+ * Control flags for do_chunk_alloc's force field CHUNK_ALLOC_NO_FORCE means to
+ * only allocate a chunk if we really need one.
+ *
+ * CHUNK_ALLOC_LIMITED means to only try and allocate one if we have very few
+ * chunks already allocated.  This is used as part of the clustering code to
+ * help make sure we have a good pool of storage to cluster in, without filling
+ * the FS with empty chunks
+ *
+ * CHUNK_ALLOC_FORCE means it must try to allocate one
+ */
+enum btrfs_chunk_alloc_enum {
+	CHUNK_ALLOC_NO_FORCE,
+	CHUNK_ALLOC_LIMITED,
+	CHUNK_ALLOC_FORCE,
+};
+
+struct btrfs_caching_control {
+	struct list_head list;
+	struct mutex mutex;
+	wait_queue_head_t wait;
+	struct btrfs_work work;
+	struct btrfs_block_group_cache *block_group;
+	u64 progress;
+	refcount_t count;
+};
+
+/* Once caching_thread() finds this much free space, it will wake up waiters. */
+#define CACHING_CTL_WAKE_UP SZ_2M
+
+struct btrfs_block_group_cache {
+	struct btrfs_key key;
+	struct btrfs_block_group_item item;
+	struct btrfs_fs_info *fs_info;
+	struct inode *inode;
+	spinlock_t lock;
+	u64 pinned;
+	u64 reserved;
+	u64 delalloc_bytes;
+	u64 bytes_super;
+	u64 flags;
+	u64 cache_generation;
+
+	/*
+	 * If the free space extent count exceeds this number, convert the block
+	 * group to bitmaps.
+	 */
+	u32 bitmap_high_thresh;
+
+	/*
+	 * If the free space extent count drops below this number, convert the
+	 * block group back to extents.
+	 */
+	u32 bitmap_low_thresh;
+
+	/*
+	 * It is just used for the delayed data space allocation because
+	 * only the data space allocation and the relative metadata update
+	 * can be done cross the transaction.
+	 */
+	struct rw_semaphore data_rwsem;
+
+	/* For raid56, this is a full stripe, without parity */
+	unsigned long full_stripe_len;
+
+	unsigned int ro;
+	unsigned int iref:1;
+	unsigned int has_caching_ctl:1;
+	unsigned int removed:1;
+
+	int disk_cache_state;
+
+	/* Cache tracking stuff */
+	int cached;
+	struct btrfs_caching_control *caching_ctl;
+	u64 last_byte_to_unpin;
+
+	struct btrfs_space_info *space_info;
+
+	/* Free space cache stuff */
+	struct btrfs_free_space_ctl *free_space_ctl;
+
+	/* Block group cache stuff */
+	struct rb_node cache_node;
+
+	/* For block groups in the same raid type */
+	struct list_head list;
+
+	/* Usage count */
+	atomic_t count;
+
+	/*
+	 * List of struct btrfs_free_clusters for this block group.
+	 * Today it will only have one thing on it, but that may change
+	 */
+	struct list_head cluster_list;
+
+	/* For delayed block group creation or deletion of empty block groups */
+	struct list_head bg_list;
+
+	/* For read-only block groups */
+	struct list_head ro_list;
+
+	atomic_t trimming;
+
+	/* For dirty block groups */
+	struct list_head dirty_list;
+	struct list_head io_list;
+
+	struct btrfs_io_ctl io_ctl;
+
+	/*
+	 * Incremented when doing extent allocations and holding a read lock
+	 * on the space_info's groups_sem semaphore.
+	 * Decremented when an ordered extent that represents an IO against this
+	 * block group's range is created (after it's added to its inode's
+	 * root's list of ordered extents) or immediately after the allocation
+	 * if it's a metadata extent or fallocate extent (for these cases we
+	 * don't create ordered extents).
+	 */
+	atomic_t reservations;
+
+	/*
+	 * Incremented while holding the spinlock *lock* by a task checking if
+	 * it can perform a nocow write (incremented if the value for the *ro*
+	 * field is 0). Decremented by such tasks once they create an ordered
+	 * extent or before that if some error happens before reaching that step.
+	 * This is to prevent races between block group relocation and nocow
+	 * writes through direct IO.
+	 */
+	atomic_t nocow_writers;
+
+	/* Lock for free space tree operations. */
+	struct mutex free_space_lock;
+
+	/*
+	 * Does the block group need to be added to the free space tree?
+	 * Protected by free_space_lock.
+	 */
+	int needs_free_space;
+
+	/* Record locked full stripes for RAID5/6 block group */
+	struct btrfs_full_stripe_locks_tree full_stripe_locks_root;
+};
+
+#ifdef CONFIG_BTRFS_DEBUG
+static inline int btrfs_should_fragment_free_space(
+		struct btrfs_block_group_cache *block_group)
+{
+	struct btrfs_fs_info *fs_info = block_group->fs_info;
+
+	return (btrfs_test_opt(fs_info, FRAGMENT_METADATA) &&
+		block_group->flags & BTRFS_BLOCK_GROUP_METADATA) ||
+	       (btrfs_test_opt(fs_info, FRAGMENT_DATA) &&
+		block_group->flags &  BTRFS_BLOCK_GROUP_DATA);
+}
+#endif
+
+struct btrfs_block_group_cache *btrfs_lookup_first_block_group(
+		struct btrfs_fs_info *info, u64 bytenr);
+struct btrfs_block_group_cache *btrfs_lookup_block_group(
+		struct btrfs_fs_info *info, u64 bytenr);
+struct btrfs_block_group_cache *btrfs_next_block_group(
+		struct btrfs_block_group_cache *cache);
+void btrfs_get_block_group(struct btrfs_block_group_cache *cache);
+void btrfs_put_block_group(struct btrfs_block_group_cache *cache);
+void btrfs_dec_block_group_reservations(struct btrfs_fs_info *fs_info,
+					const u64 start);
+void btrfs_wait_block_group_reservations(struct btrfs_block_group_cache *bg);
+bool btrfs_inc_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr);
+void btrfs_dec_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr);
+void btrfs_wait_nocow_writers(struct btrfs_block_group_cache *bg);
+void btrfs_wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
+				           u64 num_bytes);
+int btrfs_wait_block_group_cache_done(struct btrfs_block_group_cache *cache);
+int btrfs_cache_block_group(struct btrfs_block_group_cache *cache,
+			    int load_cache_only);
+void btrfs_put_caching_control(struct btrfs_caching_control *ctl);
+struct btrfs_caching_control *btrfs_get_caching_control(
+		struct btrfs_block_group_cache *cache);
+u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
+		       u64 start, u64 end);
+struct btrfs_trans_handle *btrfs_start_trans_remove_block_group(
+				struct btrfs_fs_info *fs_info,
+				const u64 chunk_offset);
+int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
+			     u64 group_start, struct extent_map *em);
+void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info);
+void btrfs_mark_bg_unused(struct btrfs_block_group_cache *bg);
+int btrfs_read_block_groups(struct btrfs_fs_info *info);
+int btrfs_make_block_group(struct btrfs_trans_handle *trans, u64 bytes_used,
+			   u64 type, u64 chunk_offset, u64 size);
+void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans);
+int btrfs_inc_block_group_ro(struct btrfs_block_group_cache *cache);
+void btrfs_dec_block_group_ro(struct btrfs_block_group_cache *cache);
+int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans);
+int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans);
+int btrfs_setup_space_cache(struct btrfs_trans_handle *trans);
+int btrfs_update_block_group(struct btrfs_trans_handle *trans,
+			     u64 bytenr, u64 num_bytes, int alloc);
+int btrfs_add_reserved_bytes(struct btrfs_block_group_cache *cache,
+			     u64 ram_bytes, u64 num_bytes, int delalloc);
+void btrfs_free_reserved_bytes(struct btrfs_block_group_cache *cache,
+			       u64 num_bytes, int delalloc);
+int btrfs_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags,
+		      enum btrfs_chunk_alloc_enum force);
+int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, u64 type);
+void check_system_chunk(struct btrfs_trans_handle *trans, const u64 type);
+u64 btrfs_get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags);
+void btrfs_put_block_group_cache(struct btrfs_fs_info *info);
+int btrfs_free_block_groups(struct btrfs_fs_info *info);
+
+static inline u64 btrfs_data_alloc_profile(struct btrfs_fs_info *fs_info)
+{
+	return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_DATA);
+}
+
+static inline u64 btrfs_metadata_alloc_profile(struct btrfs_fs_info *fs_info)
+{
+	return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_METADATA);
+}
+
+static inline u64 btrfs_system_alloc_profile(struct btrfs_fs_info *fs_info)
+{
+	return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
+}
+
+static inline int btrfs_block_group_cache_done(
+		struct btrfs_block_group_cache *cache)
+{
+	smp_mb();
+	return cache->cached == BTRFS_CACHE_FINISHED ||
+		cache->cached == BTRFS_CACHE_ERROR;
+}
+
+#endif /* BTRFS_BLOCK_GROUP_H */
diff --git a/fs/btrfs/block-rsv.c b/fs/btrfs/block-rsv.c
new file mode 100644
index 0000000..d07bd41
--- /dev/null
+++ b/fs/btrfs/block-rsv.c
@@ -0,0 +1,437 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "misc.h"
+#include "ctree.h"
+#include "block-rsv.h"
+#include "space-info.h"
+#include "transaction.h"
+
+static u64 block_rsv_release_bytes(struct btrfs_fs_info *fs_info,
+				    struct btrfs_block_rsv *block_rsv,
+				    struct btrfs_block_rsv *dest, u64 num_bytes,
+				    u64 *qgroup_to_release_ret)
+{
+	struct btrfs_space_info *space_info = block_rsv->space_info;
+	u64 qgroup_to_release = 0;
+	u64 ret;
+
+	spin_lock(&block_rsv->lock);
+	if (num_bytes == (u64)-1) {
+		num_bytes = block_rsv->size;
+		qgroup_to_release = block_rsv->qgroup_rsv_size;
+	}
+	block_rsv->size -= num_bytes;
+	if (block_rsv->reserved >= block_rsv->size) {
+		num_bytes = block_rsv->reserved - block_rsv->size;
+		block_rsv->reserved = block_rsv->size;
+		block_rsv->full = 1;
+	} else {
+		num_bytes = 0;
+	}
+	if (block_rsv->qgroup_rsv_reserved >= block_rsv->qgroup_rsv_size) {
+		qgroup_to_release = block_rsv->qgroup_rsv_reserved -
+				    block_rsv->qgroup_rsv_size;
+		block_rsv->qgroup_rsv_reserved = block_rsv->qgroup_rsv_size;
+	} else {
+		qgroup_to_release = 0;
+	}
+	spin_unlock(&block_rsv->lock);
+
+	ret = num_bytes;
+	if (num_bytes > 0) {
+		if (dest) {
+			spin_lock(&dest->lock);
+			if (!dest->full) {
+				u64 bytes_to_add;
+
+				bytes_to_add = dest->size - dest->reserved;
+				bytes_to_add = min(num_bytes, bytes_to_add);
+				dest->reserved += bytes_to_add;
+				if (dest->reserved >= dest->size)
+					dest->full = 1;
+				num_bytes -= bytes_to_add;
+			}
+			spin_unlock(&dest->lock);
+		}
+		if (num_bytes)
+			btrfs_space_info_free_bytes_may_use(fs_info,
+							    space_info,
+							    num_bytes);
+	}
+	if (qgroup_to_release_ret)
+		*qgroup_to_release_ret = qgroup_to_release;
+	return ret;
+}
+
+int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src,
+			    struct btrfs_block_rsv *dst, u64 num_bytes,
+			    bool update_size)
+{
+	int ret;
+
+	ret = btrfs_block_rsv_use_bytes(src, num_bytes);
+	if (ret)
+		return ret;
+
+	btrfs_block_rsv_add_bytes(dst, num_bytes, update_size);
+	return 0;
+}
+
+void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv, unsigned short type)
+{
+	memset(rsv, 0, sizeof(*rsv));
+	spin_lock_init(&rsv->lock);
+	rsv->type = type;
+}
+
+void btrfs_init_metadata_block_rsv(struct btrfs_fs_info *fs_info,
+				   struct btrfs_block_rsv *rsv,
+				   unsigned short type)
+{
+	btrfs_init_block_rsv(rsv, type);
+	rsv->space_info = btrfs_find_space_info(fs_info,
+					    BTRFS_BLOCK_GROUP_METADATA);
+}
+
+struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_fs_info *fs_info,
+					      unsigned short type)
+{
+	struct btrfs_block_rsv *block_rsv;
+
+	block_rsv = kmalloc(sizeof(*block_rsv), GFP_NOFS);
+	if (!block_rsv)
+		return NULL;
+
+	btrfs_init_metadata_block_rsv(fs_info, block_rsv, type);
+	return block_rsv;
+}
+
+void btrfs_free_block_rsv(struct btrfs_fs_info *fs_info,
+			  struct btrfs_block_rsv *rsv)
+{
+	if (!rsv)
+		return;
+	btrfs_block_rsv_release(fs_info, rsv, (u64)-1);
+	kfree(rsv);
+}
+
+int btrfs_block_rsv_add(struct btrfs_root *root,
+			struct btrfs_block_rsv *block_rsv, u64 num_bytes,
+			enum btrfs_reserve_flush_enum flush)
+{
+	int ret;
+
+	if (num_bytes == 0)
+		return 0;
+
+	ret = btrfs_reserve_metadata_bytes(root, block_rsv, num_bytes, flush);
+	if (!ret)
+		btrfs_block_rsv_add_bytes(block_rsv, num_bytes, true);
+
+	return ret;
+}
+
+int btrfs_block_rsv_check(struct btrfs_block_rsv *block_rsv, int min_factor)
+{
+	u64 num_bytes = 0;
+	int ret = -ENOSPC;
+
+	if (!block_rsv)
+		return 0;
+
+	spin_lock(&block_rsv->lock);
+	num_bytes = div_factor(block_rsv->size, min_factor);
+	if (block_rsv->reserved >= num_bytes)
+		ret = 0;
+	spin_unlock(&block_rsv->lock);
+
+	return ret;
+}
+
+int btrfs_block_rsv_refill(struct btrfs_root *root,
+			   struct btrfs_block_rsv *block_rsv, u64 min_reserved,
+			   enum btrfs_reserve_flush_enum flush)
+{
+	u64 num_bytes = 0;
+	int ret = -ENOSPC;
+
+	if (!block_rsv)
+		return 0;
+
+	spin_lock(&block_rsv->lock);
+	num_bytes = min_reserved;
+	if (block_rsv->reserved >= num_bytes)
+		ret = 0;
+	else
+		num_bytes -= block_rsv->reserved;
+	spin_unlock(&block_rsv->lock);
+
+	if (!ret)
+		return 0;
+
+	ret = btrfs_reserve_metadata_bytes(root, block_rsv, num_bytes, flush);
+	if (!ret) {
+		btrfs_block_rsv_add_bytes(block_rsv, num_bytes, false);
+		return 0;
+	}
+
+	return ret;
+}
+
+u64 __btrfs_block_rsv_release(struct btrfs_fs_info *fs_info,
+			      struct btrfs_block_rsv *block_rsv,
+			      u64 num_bytes, u64 *qgroup_to_release)
+{
+	struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
+	struct btrfs_block_rsv *delayed_rsv = &fs_info->delayed_refs_rsv;
+	struct btrfs_block_rsv *target = NULL;
+
+	/*
+	 * If we are the delayed_rsv then push to the global rsv, otherwise dump
+	 * into the delayed rsv if it is not full.
+	 */
+	if (block_rsv == delayed_rsv)
+		target = global_rsv;
+	else if (block_rsv != global_rsv && !delayed_rsv->full)
+		target = delayed_rsv;
+
+	if (target && block_rsv->space_info != target->space_info)
+		target = NULL;
+
+	return block_rsv_release_bytes(fs_info, block_rsv, target, num_bytes,
+				       qgroup_to_release);
+}
+
+int btrfs_block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv, u64 num_bytes)
+{
+	int ret = -ENOSPC;
+
+	spin_lock(&block_rsv->lock);
+	if (block_rsv->reserved >= num_bytes) {
+		block_rsv->reserved -= num_bytes;
+		if (block_rsv->reserved < block_rsv->size)
+			block_rsv->full = 0;
+		ret = 0;
+	}
+	spin_unlock(&block_rsv->lock);
+	return ret;
+}
+
+void btrfs_block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
+			       u64 num_bytes, bool update_size)
+{
+	spin_lock(&block_rsv->lock);
+	block_rsv->reserved += num_bytes;
+	if (update_size)
+		block_rsv->size += num_bytes;
+	else if (block_rsv->reserved >= block_rsv->size)
+		block_rsv->full = 1;
+	spin_unlock(&block_rsv->lock);
+}
+
+int btrfs_cond_migrate_bytes(struct btrfs_fs_info *fs_info,
+			     struct btrfs_block_rsv *dest, u64 num_bytes,
+			     int min_factor)
+{
+	struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
+	u64 min_bytes;
+
+	if (global_rsv->space_info != dest->space_info)
+		return -ENOSPC;
+
+	spin_lock(&global_rsv->lock);
+	min_bytes = div_factor(global_rsv->size, min_factor);
+	if (global_rsv->reserved < min_bytes + num_bytes) {
+		spin_unlock(&global_rsv->lock);
+		return -ENOSPC;
+	}
+	global_rsv->reserved -= num_bytes;
+	if (global_rsv->reserved < global_rsv->size)
+		global_rsv->full = 0;
+	spin_unlock(&global_rsv->lock);
+
+	btrfs_block_rsv_add_bytes(dest, num_bytes, true);
+	return 0;
+}
+
+void btrfs_update_global_block_rsv(struct btrfs_fs_info *fs_info)
+{
+	struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
+	struct btrfs_space_info *sinfo = block_rsv->space_info;
+	u64 num_bytes;
+	unsigned min_items;
+
+	/*
+	 * The global block rsv is based on the size of the extent tree, the
+	 * checksum tree and the root tree.  If the fs is empty we want to set
+	 * it to a minimal amount for safety.
+	 */
+	num_bytes = btrfs_root_used(&fs_info->extent_root->root_item) +
+		btrfs_root_used(&fs_info->csum_root->root_item) +
+		btrfs_root_used(&fs_info->tree_root->root_item);
+
+	/*
+	 * We at a minimum are going to modify the csum root, the tree root, and
+	 * the extent root.
+	 */
+	min_items = 3;
+
+	/*
+	 * But we also want to reserve enough space so we can do the fallback
+	 * global reserve for an unlink, which is an additional 5 items (see the
+	 * comment in __unlink_start_trans for what we're modifying.)
+	 *
+	 * But we also need space for the delayed ref updates from the unlink,
+	 * so its 10, 5 for the actual operation, and 5 for the delayed ref
+	 * updates.
+	 */
+	min_items += 10;
+
+	num_bytes = max_t(u64, num_bytes,
+			  btrfs_calc_insert_metadata_size(fs_info, min_items));
+
+	spin_lock(&sinfo->lock);
+	spin_lock(&block_rsv->lock);
+
+	block_rsv->size = min_t(u64, num_bytes, SZ_512M);
+
+	if (block_rsv->reserved < block_rsv->size) {
+		num_bytes = block_rsv->size - block_rsv->reserved;
+		block_rsv->reserved += num_bytes;
+		btrfs_space_info_update_bytes_may_use(fs_info, sinfo,
+						      num_bytes);
+	} else if (block_rsv->reserved > block_rsv->size) {
+		num_bytes = block_rsv->reserved - block_rsv->size;
+		btrfs_space_info_update_bytes_may_use(fs_info, sinfo,
+						      -num_bytes);
+		block_rsv->reserved = block_rsv->size;
+		btrfs_try_granting_tickets(fs_info, sinfo);
+	}
+
+	if (block_rsv->reserved == block_rsv->size)
+		block_rsv->full = 1;
+	else
+		block_rsv->full = 0;
+
+	spin_unlock(&block_rsv->lock);
+	spin_unlock(&sinfo->lock);
+}
+
+void btrfs_init_global_block_rsv(struct btrfs_fs_info *fs_info)
+{
+	struct btrfs_space_info *space_info;
+
+	space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
+	fs_info->chunk_block_rsv.space_info = space_info;
+
+	space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
+	fs_info->global_block_rsv.space_info = space_info;
+	fs_info->trans_block_rsv.space_info = space_info;
+	fs_info->empty_block_rsv.space_info = space_info;
+	fs_info->delayed_block_rsv.space_info = space_info;
+	fs_info->delayed_refs_rsv.space_info = space_info;
+
+	fs_info->extent_root->block_rsv = &fs_info->delayed_refs_rsv;
+	fs_info->csum_root->block_rsv = &fs_info->delayed_refs_rsv;
+	fs_info->dev_root->block_rsv = &fs_info->global_block_rsv;
+	fs_info->tree_root->block_rsv = &fs_info->global_block_rsv;
+	if (fs_info->quota_root)
+		fs_info->quota_root->block_rsv = &fs_info->global_block_rsv;
+	fs_info->chunk_root->block_rsv = &fs_info->chunk_block_rsv;
+
+	btrfs_update_global_block_rsv(fs_info);
+}
+
+void btrfs_release_global_block_rsv(struct btrfs_fs_info *fs_info)
+{
+	btrfs_block_rsv_release(fs_info, &fs_info->global_block_rsv, (u64)-1);
+	WARN_ON(fs_info->trans_block_rsv.size > 0);
+	WARN_ON(fs_info->trans_block_rsv.reserved > 0);
+	WARN_ON(fs_info->chunk_block_rsv.size > 0);
+	WARN_ON(fs_info->chunk_block_rsv.reserved > 0);
+	WARN_ON(fs_info->delayed_block_rsv.size > 0);
+	WARN_ON(fs_info->delayed_block_rsv.reserved > 0);
+	WARN_ON(fs_info->delayed_refs_rsv.reserved > 0);
+	WARN_ON(fs_info->delayed_refs_rsv.size > 0);
+}
+
+static struct btrfs_block_rsv *get_block_rsv(
+					const struct btrfs_trans_handle *trans,
+					const struct btrfs_root *root)
+{
+	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct btrfs_block_rsv *block_rsv = NULL;
+
+	if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
+	    (root == fs_info->csum_root && trans->adding_csums) ||
+	    (root == fs_info->uuid_root))
+		block_rsv = trans->block_rsv;
+
+	if (!block_rsv)
+		block_rsv = root->block_rsv;
+
+	if (!block_rsv)
+		block_rsv = &fs_info->empty_block_rsv;
+
+	return block_rsv;
+}
+
+struct btrfs_block_rsv *btrfs_use_block_rsv(struct btrfs_trans_handle *trans,
+					    struct btrfs_root *root,
+					    u32 blocksize)
+{
+	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct btrfs_block_rsv *block_rsv;
+	struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
+	int ret;
+	bool global_updated = false;
+
+	block_rsv = get_block_rsv(trans, root);
+
+	if (unlikely(block_rsv->size == 0))
+		goto try_reserve;
+again:
+	ret = btrfs_block_rsv_use_bytes(block_rsv, blocksize);
+	if (!ret)
+		return block_rsv;
+
+	if (block_rsv->failfast)
+		return ERR_PTR(ret);
+
+	if (block_rsv->type == BTRFS_BLOCK_RSV_GLOBAL && !global_updated) {
+		global_updated = true;
+		btrfs_update_global_block_rsv(fs_info);
+		goto again;
+	}
+
+	/*
+	 * The global reserve still exists to save us from ourselves, so don't
+	 * warn_on if we are short on our delayed refs reserve.
+	 */
+	if (block_rsv->type != BTRFS_BLOCK_RSV_DELREFS &&
+	    btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
+		static DEFINE_RATELIMIT_STATE(_rs,
+				DEFAULT_RATELIMIT_INTERVAL * 10,
+				/*DEFAULT_RATELIMIT_BURST*/ 1);
+		if (__ratelimit(&_rs))
+			WARN(1, KERN_DEBUG
+				"BTRFS: block rsv returned %d\n", ret);
+	}
+try_reserve:
+	ret = btrfs_reserve_metadata_bytes(root, block_rsv, blocksize,
+					   BTRFS_RESERVE_NO_FLUSH);
+	if (!ret)
+		return block_rsv;
+	/*
+	 * If we couldn't reserve metadata bytes try and use some from
+	 * the global reserve if its space type is the same as the global
+	 * reservation.
+	 */
+	if (block_rsv->type != BTRFS_BLOCK_RSV_GLOBAL &&
+	    block_rsv->space_info == global_rsv->space_info) {
+		ret = btrfs_block_rsv_use_bytes(global_rsv, blocksize);
+		if (!ret)
+			return global_rsv;
+	}
+	return ERR_PTR(ret);
+}
diff --git a/fs/btrfs/block-rsv.h b/fs/btrfs/block-rsv.h
new file mode 100644
index 0000000..d1428bb
--- /dev/null
+++ b/fs/btrfs/block-rsv.h
@@ -0,0 +1,101 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef BTRFS_BLOCK_RSV_H
+#define BTRFS_BLOCK_RSV_H
+
+struct btrfs_trans_handle;
+enum btrfs_reserve_flush_enum;
+
+/*
+ * Types of block reserves
+ */
+enum {
+	BTRFS_BLOCK_RSV_GLOBAL,
+	BTRFS_BLOCK_RSV_DELALLOC,
+	BTRFS_BLOCK_RSV_TRANS,
+	BTRFS_BLOCK_RSV_CHUNK,
+	BTRFS_BLOCK_RSV_DELOPS,
+	BTRFS_BLOCK_RSV_DELREFS,
+	BTRFS_BLOCK_RSV_EMPTY,
+	BTRFS_BLOCK_RSV_TEMP,
+};
+
+struct btrfs_block_rsv {
+	u64 size;
+	u64 reserved;
+	struct btrfs_space_info *space_info;
+	spinlock_t lock;
+	unsigned short full;
+	unsigned short type;
+	unsigned short failfast;
+
+	/*
+	 * Qgroup equivalent for @size @reserved
+	 *
+	 * Unlike normal @size/@reserved for inode rsv, qgroup doesn't care
+	 * about things like csum size nor how many tree blocks it will need to
+	 * reserve.
+	 *
+	 * Qgroup cares more about net change of the extent usage.
+	 *
+	 * So for one newly inserted file extent, in worst case it will cause
+	 * leaf split and level increase, nodesize for each file extent is
+	 * already too much.
+	 *
+	 * In short, qgroup_size/reserved is the upper limit of possible needed
+	 * qgroup metadata reservation.
+	 */
+	u64 qgroup_rsv_size;
+	u64 qgroup_rsv_reserved;
+};
+
+void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv, unsigned short type);
+struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_fs_info *fs_info,
+					      unsigned short type);
+void btrfs_init_metadata_block_rsv(struct btrfs_fs_info *fs_info,
+				   struct btrfs_block_rsv *rsv,
+				   unsigned short type);
+void btrfs_free_block_rsv(struct btrfs_fs_info *fs_info,
+			  struct btrfs_block_rsv *rsv);
+int btrfs_block_rsv_add(struct btrfs_root *root,
+			struct btrfs_block_rsv *block_rsv, u64 num_bytes,
+			enum btrfs_reserve_flush_enum flush);
+int btrfs_block_rsv_check(struct btrfs_block_rsv *block_rsv, int min_factor);
+int btrfs_block_rsv_refill(struct btrfs_root *root,
+			   struct btrfs_block_rsv *block_rsv, u64 min_reserved,
+			   enum btrfs_reserve_flush_enum flush);
+int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src_rsv,
+			    struct btrfs_block_rsv *dst_rsv, u64 num_bytes,
+			    bool update_size);
+int btrfs_block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv, u64 num_bytes);
+int btrfs_cond_migrate_bytes(struct btrfs_fs_info *fs_info,
+			     struct btrfs_block_rsv *dest, u64 num_bytes,
+			     int min_factor);
+void btrfs_block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
+			       u64 num_bytes, bool update_size);
+u64 __btrfs_block_rsv_release(struct btrfs_fs_info *fs_info,
+			      struct btrfs_block_rsv *block_rsv,
+			      u64 num_bytes, u64 *qgroup_to_release);
+void btrfs_update_global_block_rsv(struct btrfs_fs_info *fs_info);
+void btrfs_init_global_block_rsv(struct btrfs_fs_info *fs_info);
+void btrfs_release_global_block_rsv(struct btrfs_fs_info *fs_info);
+struct btrfs_block_rsv *btrfs_use_block_rsv(struct btrfs_trans_handle *trans,
+					    struct btrfs_root *root,
+					    u32 blocksize);
+
+static inline void btrfs_block_rsv_release(struct btrfs_fs_info *fs_info,
+					   struct btrfs_block_rsv *block_rsv,
+					   u64 num_bytes)
+{
+	__btrfs_block_rsv_release(fs_info, block_rsv, num_bytes, NULL);
+}
+
+static inline void btrfs_unuse_block_rsv(struct btrfs_fs_info *fs_info,
+					 struct btrfs_block_rsv *block_rsv,
+					 u32 blocksize)
+{
+	btrfs_block_rsv_add_bytes(block_rsv, blocksize, false);
+	btrfs_block_rsv_release(fs_info, block_rsv, 0);
+}
+
+#endif /* BTRFS_BLOCK_RSV_H */
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index 1343ac5..f853835 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -20,7 +20,7 @@
  * new data the application may have written before commit.
  */
 enum {
-	BTRFS_INODE_ORDERED_DATA_CLOSE = 0,
+	BTRFS_INODE_ORDERED_DATA_CLOSE,
 	BTRFS_INODE_DUMMY,
 	BTRFS_INODE_IN_DEFRAG,
 	BTRFS_INODE_HAS_ASYNC_EXTENT,
@@ -29,6 +29,7 @@
 	BTRFS_INODE_IN_DELALLOC_LIST,
 	BTRFS_INODE_READDIO_NEED_LOCK,
 	BTRFS_INODE_HAS_PROPS,
+	BTRFS_INODE_SNAPSHOT_FLUSH,
 };
 
 /* in memory btrfs inode */
@@ -196,8 +197,6 @@
 	struct inode vfs_inode;
 };
 
-extern unsigned char btrfs_filetype_table[];
-
 static inline struct btrfs_inode *BTRFS_I(const struct inode *inode)
 {
 	return container_of(inode, struct btrfs_inode, vfs_inode);
@@ -206,7 +205,7 @@
 static inline unsigned long btrfs_inode_hash(u64 objectid,
 					     const struct btrfs_root *root)
 {
-	u64 h = objectid ^ (root->objectid * GOLDEN_RATIO_PRIME);
+	u64 h = objectid ^ (root->root_key.objectid * GOLDEN_RATIO_PRIME);
 
 #if BITS_PER_LONG == 32
 	h = (h >> 32) ^ (h & 0xffffffff);
@@ -253,6 +252,11 @@
 	return false;
 }
 
+static inline bool is_data_inode(struct inode *inode)
+{
+	return btrfs_ino(BTRFS_I(inode)) != BTRFS_BTREE_INODE_OBJECTID;
+}
+
 static inline void btrfs_mod_outstanding_extents(struct btrfs_inode *inode,
 						 int mod)
 {
@@ -333,22 +337,34 @@
 	clear_bit(BTRFS_INODE_READDIO_NEED_LOCK, &inode->runtime_flags);
 }
 
+/* Array of bytes with variable length, hexadecimal format 0x1234 */
+#define CSUM_FMT				"0x%*phN"
+#define CSUM_FMT_VALUE(size, bytes)		size, bytes
+
 static inline void btrfs_print_data_csum_error(struct btrfs_inode *inode,
-		u64 logical_start, u32 csum, u32 csum_expected, int mirror_num)
+		u64 logical_start, u8 *csum, u8 *csum_expected, int mirror_num)
 {
 	struct btrfs_root *root = inode->root;
+	struct btrfs_super_block *sb = root->fs_info->super_copy;
+	const u16 csum_size = btrfs_super_csum_size(sb);
 
 	/* Output minus objectid, which is more meaningful */
-	if (root->objectid >= BTRFS_LAST_FREE_OBJECTID)
+	if (root->root_key.objectid >= BTRFS_LAST_FREE_OBJECTID)
 		btrfs_warn_rl(root->fs_info,
-	"csum failed root %lld ino %lld off %llu csum 0x%08x expected csum 0x%08x mirror %d",
-			root->objectid, btrfs_ino(inode),
-			logical_start, csum, csum_expected, mirror_num);
+"csum failed root %lld ino %lld off %llu csum " CSUM_FMT " expected csum " CSUM_FMT " mirror %d",
+			root->root_key.objectid, btrfs_ino(inode),
+			logical_start,
+			CSUM_FMT_VALUE(csum_size, csum),
+			CSUM_FMT_VALUE(csum_size, csum_expected),
+			mirror_num);
 	else
 		btrfs_warn_rl(root->fs_info,
-	"csum failed root %llu ino %llu off %llu csum 0x%08x expected csum 0x%08x mirror %d",
-			root->objectid, btrfs_ino(inode),
-			logical_start, csum, csum_expected, mirror_num);
+"csum failed root %llu ino %llu off %llu csum " CSUM_FMT " expected csum " CSUM_FMT " mirror %d",
+			root->root_key.objectid, btrfs_ino(inode),
+			logical_start,
+			CSUM_FMT_VALUE(csum_size, csum),
+			CSUM_FMT_VALUE(csum_size, csum_expected),
+			mirror_num);
 }
 
 #endif
diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c
index 833cf3c..0b52ab4 100644
--- a/fs/btrfs/check-integrity.c
+++ b/fs/btrfs/check-integrity.c
@@ -83,7 +83,7 @@
 #include <linux/blkdev.h>
 #include <linux/mm.h>
 #include <linux/string.h>
-#include <linux/crc32c.h>
+#include <crypto/hash.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -940,7 +940,7 @@
 	kfree(sf);
 }
 
-static int btrfsic_process_metablock(
+static noinline_for_stack int btrfsic_process_metablock(
 		struct btrfsic_state *state,
 		struct btrfsic_block *const first_block,
 		struct btrfsic_block_data_ctx *const first_block_ctx,
@@ -1202,24 +1202,24 @@
 	void *dstv, u32 offset, size_t len)
 {
 	size_t cur;
-	size_t offset_in_page;
+	size_t pgoff;
 	char *kaddr;
 	char *dst = (char *)dstv;
-	size_t start_offset = block_ctx->start & ((u64)PAGE_SIZE - 1);
+	size_t start_offset = offset_in_page(block_ctx->start);
 	unsigned long i = (start_offset + offset) >> PAGE_SHIFT;
 
 	WARN_ON(offset + len > block_ctx->len);
-	offset_in_page = (start_offset + offset) & (PAGE_SIZE - 1);
+	pgoff = offset_in_page(start_offset + offset);
 
 	while (len > 0) {
-		cur = min(len, ((size_t)PAGE_SIZE - offset_in_page));
+		cur = min(len, ((size_t)PAGE_SIZE - pgoff));
 		BUG_ON(i >= DIV_ROUND_UP(block_ctx->len, PAGE_SIZE));
 		kaddr = block_ctx->datav[i];
-		memcpy(dst, kaddr + offset_in_page, cur);
+		memcpy(dst, kaddr + pgoff, cur);
 
 		dst += cur;
 		len -= cur;
-		offset_in_page = 0;
+		pgoff = 0;
 		i++;
 	}
 }
@@ -1594,13 +1594,14 @@
 {
 	unsigned int num_pages;
 	unsigned int i;
+	size_t size;
 	u64 dev_bytenr;
 	int ret;
 
 	BUG_ON(block_ctx->datav);
 	BUG_ON(block_ctx->pagev);
 	BUG_ON(block_ctx->mem_to_free);
-	if (block_ctx->dev_bytenr & ((u64)PAGE_SIZE - 1)) {
+	if (!PAGE_ALIGNED(block_ctx->dev_bytenr)) {
 		pr_info("btrfsic: read_block() with unaligned bytenr %llu\n",
 		       block_ctx->dev_bytenr);
 		return -1;
@@ -1608,9 +1609,8 @@
 
 	num_pages = (block_ctx->len + (u64)PAGE_SIZE - 1) >>
 		    PAGE_SHIFT;
-	block_ctx->mem_to_free = kcalloc(sizeof(*block_ctx->datav) +
-						sizeof(*block_ctx->pagev),
-					 num_pages, GFP_NOFS);
+	size = sizeof(*block_ctx->datav) + sizeof(*block_ctx->pagev);
+	block_ctx->mem_to_free = kcalloc(num_pages, size, GFP_NOFS);
 	if (!block_ctx->mem_to_free)
 		return -ENOMEM;
 	block_ctx->datav = block_ctx->mem_to_free;
@@ -1706,13 +1706,14 @@
  * Test whether the disk block contains a tree block (leaf or node)
  * (note that this test fails for the super block)
  */
-static int btrfsic_test_for_metadata(struct btrfsic_state *state,
-				     char **datav, unsigned int num_pages)
+static noinline_for_stack int btrfsic_test_for_metadata(
+		struct btrfsic_state *state,
+		char **datav, unsigned int num_pages)
 {
 	struct btrfs_fs_info *fs_info = state->fs_info;
+	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
 	struct btrfs_header *h;
 	u8 csum[BTRFS_CSUM_SIZE];
-	u32 crc = ~(u32)0;
 	unsigned int i;
 
 	if (num_pages * PAGE_SIZE < state->metablock_size)
@@ -1720,17 +1721,20 @@
 	num_pages = state->metablock_size >> PAGE_SHIFT;
 	h = (struct btrfs_header *)datav[0];
 
-	if (memcmp(h->fsid, fs_info->fsid, BTRFS_FSID_SIZE))
+	if (memcmp(h->fsid, fs_info->fs_devices->fsid, BTRFS_FSID_SIZE))
 		return 1;
 
+	shash->tfm = fs_info->csum_shash;
+	crypto_shash_init(shash);
+
 	for (i = 0; i < num_pages; i++) {
 		u8 *data = i ? datav[i] : (datav[i] + BTRFS_CSUM_SIZE);
 		size_t sublen = i ? PAGE_SIZE :
 				    (PAGE_SIZE - BTRFS_CSUM_SIZE);
 
-		crc = crc32c(crc, data, sublen);
+		crypto_shash_update(shash, data, sublen);
 	}
-	btrfs_csum_final(crc, csum);
+	crypto_shash_final(shash, csum);
 	if (memcmp(csum, h->csum, state->csum_size))
 		return 1;
 
@@ -1778,7 +1782,7 @@
 				return;
 			}
 			is_metadata = 1;
-			BUG_ON(BTRFS_SUPER_INFO_SIZE & (PAGE_SIZE - 1));
+			BUG_ON(!PAGE_ALIGNED(BTRFS_SUPER_INFO_SIZE));
 			processed_len = BTRFS_SUPER_INFO_SIZE;
 			if (state->print_mask &
 			    BTRFSIC_PRINT_MASK_TREE_BEFORE_SB_WRITE) {
@@ -2327,7 +2331,7 @@
 		 * write operations. Therefore it keeps the linkage
 		 * information for a block until a block is
 		 * rewritten. This can temporarily cause incorrect
-		 * and even circular linkage informations. This
+		 * and even circular linkage information. This
 		 * causes no harm unless such blocks are referenced
 		 * by the most recent super block.
 		 */
@@ -2892,12 +2896,12 @@
 	struct list_head *dev_head = &fs_devices->devices;
 	struct btrfs_device *device;
 
-	if (fs_info->nodesize & ((u64)PAGE_SIZE - 1)) {
+	if (!PAGE_ALIGNED(fs_info->nodesize)) {
 		pr_info("btrfsic: cannot handle nodesize %d not being a multiple of PAGE_SIZE %ld!\n",
 		       fs_info->nodesize, PAGE_SIZE);
 		return -1;
 	}
-	if (fs_info->sectorsize & ((u64)PAGE_SIZE - 1)) {
+	if (!PAGE_ALIGNED(fs_info->sectorsize)) {
 		pr_info("btrfsic: cannot handle sectorsize %d not being a multiple of PAGE_SIZE %ld!\n",
 		       fs_info->sectorsize, PAGE_SIZE);
 		return -1;
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 9bfa665..b05b361 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -17,6 +17,8 @@
 #include <linux/slab.h>
 #include <linux/sched/mm.h>
 #include <linux/log2.h>
+#include <crypto/hash.h>
+#include "misc.h"
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -42,6 +44,22 @@
 	return NULL;
 }
 
+bool btrfs_compress_is_valid_type(const char *str, size_t len)
+{
+	int i;
+
+	for (i = 1; i < ARRAY_SIZE(btrfs_compress_types); i++) {
+		size_t comp_len = strlen(btrfs_compress_types[i]);
+
+		if (len < comp_len)
+			continue;
+
+		if (!strncmp(btrfs_compress_types[i], str, comp_len))
+			return true;
+	}
+	return false;
+}
+
 static int btrfs_decompress_bio(struct compressed_bio *cb);
 
 static inline int compressed_bio_size(struct btrfs_fs_info *fs_info,
@@ -57,32 +75,37 @@
 				 struct compressed_bio *cb,
 				 u64 disk_start)
 {
+	struct btrfs_fs_info *fs_info = inode->root->fs_info;
+	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
+	const u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
 	int ret;
 	struct page *page;
 	unsigned long i;
 	char *kaddr;
-	u32 csum;
-	u32 *cb_sum = &cb->sums;
+	u8 csum[BTRFS_CSUM_SIZE];
+	u8 *cb_sum = cb->sums;
 
 	if (inode->flags & BTRFS_INODE_NODATASUM)
 		return 0;
 
+	shash->tfm = fs_info->csum_shash;
+
 	for (i = 0; i < cb->nr_pages; i++) {
 		page = cb->compressed_pages[i];
-		csum = ~(u32)0;
 
+		crypto_shash_init(shash);
 		kaddr = kmap_atomic(page);
-		csum = btrfs_csum_data(kaddr, csum, PAGE_SIZE);
-		btrfs_csum_final(csum, (u8 *)&csum);
+		crypto_shash_update(shash, kaddr, PAGE_SIZE);
 		kunmap_atomic(kaddr);
+		crypto_shash_final(shash, (u8 *)&csum);
 
-		if (csum != *cb_sum) {
-			btrfs_print_data_csum_error(inode, disk_start, csum,
-					*cb_sum, cb->mirror_num);
+		if (memcmp(&csum, cb_sum, csum_size)) {
+			btrfs_print_data_csum_error(inode, disk_start,
+					csum, cb_sum, cb->mirror_num);
 			ret = -EIO;
 			goto fail;
 		}
-		cb_sum++;
+		cb_sum += csum_size;
 
 	}
 	ret = 0;
@@ -160,15 +183,15 @@
 	if (cb->errors) {
 		bio_io_error(cb->orig_bio);
 	} else {
-		int i;
 		struct bio_vec *bvec;
+		struct bvec_iter_all iter_all;
 
 		/*
 		 * we have verified the checksum already, set page
 		 * checked so the end_io handlers know about it
 		 */
 		ASSERT(!bio_flagged(bio, BIO_CLONED));
-		bio_for_each_segment_all(bvec, cb->orig_bio, i)
+		bio_for_each_segment_all(bvec, cb->orig_bio, iter_all)
 			SetPageChecked(bvec->bv_page);
 
 		bio_endio(cb->orig_bio);
@@ -229,7 +252,6 @@
  */
 static void end_compressed_bio_write(struct bio *bio)
 {
-	struct extent_io_tree *tree;
 	struct compressed_bio *cb = bio->bi_private;
 	struct inode *inode;
 	struct page *page;
@@ -248,14 +270,10 @@
 	 * call back into the FS and do all the end_io operations
 	 */
 	inode = cb->inode;
-	tree = &BTRFS_I(inode)->io_tree;
 	cb->compressed_pages[0]->mapping = cb->inode->i_mapping;
-	tree->ops->writepage_end_io_hook(cb->compressed_pages[0],
-					 cb->start,
-					 cb->start + cb->len - 1,
-					 NULL,
-					 bio->bi_status ?
-					 BLK_STS_OK : BLK_STS_NOTSUPP);
+	btrfs_writepage_endio_finish_ordered(cb->compressed_pages[0],
+			cb->start, cb->start + cb->len - 1,
+			bio->bi_status == BLK_STS_OK);
 	cb->compressed_pages[0]->mapping = NULL;
 
 	end_compressed_writeback(inode, cb);
@@ -306,7 +324,7 @@
 	blk_status_t ret;
 	int skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
 
-	WARN_ON(start & ((u64)PAGE_SIZE - 1));
+	WARN_ON(!PAGE_ALIGNED(start));
 	cb = kmalloc(compressed_bio_size(fs_info, compressed_len), GFP_NOFS);
 	if (!cb)
 		return BLK_STS_RESOURCE;
@@ -323,7 +341,8 @@
 
 	bdev = fs_info->fs_devices->latest_bdev;
 
-	bio = btrfs_bio_alloc(bdev, first_byte);
+	bio = btrfs_bio_alloc(first_byte);
+	bio_set_dev(bio, bdev);
 	bio->bi_opf = REQ_OP_WRITE | write_flags;
 	bio->bi_private = cb;
 	bio->bi_end_io = end_compressed_bio_write;
@@ -337,7 +356,8 @@
 		page = compressed_pages[pg_index];
 		page->mapping = inode->i_mapping;
 		if (bio->bi_iter.bi_size)
-			submit = btrfs_merge_bio_hook(page, 0, PAGE_SIZE, bio, 0);
+			submit = btrfs_bio_fits_in_stripe(page, PAGE_SIZE, bio,
+							  0);
 
 		page->mapping = NULL;
 		if (submit || bio_add_page(bio, page, PAGE_SIZE, 0) <
@@ -364,7 +384,8 @@
 				bio_endio(bio);
 			}
 
-			bio = btrfs_bio_alloc(bdev, first_byte);
+			bio = btrfs_bio_alloc(first_byte);
+			bio_set_dev(bio, bdev);
 			bio->bi_opf = REQ_OP_WRITE | write_flags;
 			bio->bi_private = cb;
 			bio->bi_end_io = end_compressed_bio_write;
@@ -437,10 +458,8 @@
 		if (pg_index > end_index)
 			break;
 
-		rcu_read_lock();
-		page = radix_tree_lookup(&mapping->i_pages, pg_index);
-		rcu_read_unlock();
-		if (page && !radix_tree_exceptional_entry(page)) {
+		page = xa_load(&mapping->i_pages, pg_index);
+		if (page && !xa_is_value(page)) {
 			misses++;
 			if (misses > 4)
 				break;
@@ -483,7 +502,7 @@
 
 		if (page->index == end_index) {
 			char *userpage;
-			size_t zero_offset = isize & (PAGE_SIZE - 1);
+			size_t zero_offset = offset_in_page(isize);
 
 			if (zero_offset) {
 				int zeros;
@@ -528,7 +547,6 @@
 				 int mirror_num, unsigned long bio_flags)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
-	struct extent_io_tree *tree;
 	struct extent_map_tree *em_tree;
 	struct compressed_bio *cb;
 	unsigned long compressed_len;
@@ -543,9 +561,9 @@
 	struct extent_map *em;
 	blk_status_t ret = BLK_STS_RESOURCE;
 	int faili = 0;
-	u32 *sums;
+	const u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
+	u8 *sums;
 
-	tree = &BTRFS_I(inode)->io_tree;
 	em_tree = &BTRFS_I(inode)->extent_tree;
 
 	/* we need the actual starting offset of this extent in the file */
@@ -566,7 +584,7 @@
 	cb->errors = 0;
 	cb->inode = inode;
 	cb->mirror_num = mirror_num;
-	sums = &cb->sums;
+	sums = cb->sums;
 
 	cb->start = em->orig_start;
 	em_len = em->len;
@@ -605,7 +623,8 @@
 	/* include any pages we added in add_ra-bio_pages */
 	cb->len = bio->bi_iter.bi_size;
 
-	comp_bio = btrfs_bio_alloc(bdev, cur_disk_byte);
+	comp_bio = btrfs_bio_alloc(cur_disk_byte);
+	bio_set_dev(comp_bio, bdev);
 	comp_bio->bi_opf = REQ_OP_READ;
 	comp_bio->bi_private = cb;
 	comp_bio->bi_end_io = end_compressed_bio_read;
@@ -619,12 +638,14 @@
 		page->index = em_start >> PAGE_SHIFT;
 
 		if (comp_bio->bi_iter.bi_size)
-			submit = btrfs_merge_bio_hook(page, 0, PAGE_SIZE,
-					comp_bio, 0);
+			submit = btrfs_bio_fits_in_stripe(page, PAGE_SIZE,
+							  comp_bio, 0);
 
 		page->mapping = NULL;
 		if (submit || bio_add_page(comp_bio, page, PAGE_SIZE, 0) <
 		    PAGE_SIZE) {
+			unsigned int nr_sectors;
+
 			ret = btrfs_bio_wq_end_io(fs_info, comp_bio,
 						  BTRFS_WQ_ENDIO_DATA);
 			BUG_ON(ret); /* -ENOMEM */
@@ -642,8 +663,10 @@
 							    sums);
 				BUG_ON(ret); /* -ENOMEM */
 			}
-			sums += DIV_ROUND_UP(comp_bio->bi_iter.bi_size,
-					     fs_info->sectorsize);
+
+			nr_sectors = DIV_ROUND_UP(comp_bio->bi_iter.bi_size,
+						  fs_info->sectorsize);
+			sums += csum_size * nr_sectors;
 
 			ret = btrfs_map_bio(fs_info, comp_bio, mirror_num, 0);
 			if (ret) {
@@ -651,7 +674,8 @@
 				bio_endio(comp_bio);
 			}
 
-			comp_bio = btrfs_bio_alloc(bdev, cur_disk_byte);
+			comp_bio = btrfs_bio_alloc(cur_disk_byte);
+			bio_set_dev(comp_bio, bdev);
 			comp_bio->bi_opf = REQ_OP_READ;
 			comp_bio->bi_private = cb;
 			comp_bio->bi_end_io = end_compressed_bio_read;
@@ -738,6 +762,28 @@
 	struct list_head list;
 };
 
+static struct workspace_manager heuristic_wsm;
+
+static void heuristic_init_workspace_manager(void)
+{
+	btrfs_init_workspace_manager(&heuristic_wsm, &btrfs_heuristic_compress);
+}
+
+static void heuristic_cleanup_workspace_manager(void)
+{
+	btrfs_cleanup_workspace_manager(&heuristic_wsm);
+}
+
+static struct list_head *heuristic_get_workspace(unsigned int level)
+{
+	return btrfs_get_workspace(&heuristic_wsm, level);
+}
+
+static void heuristic_put_workspace(struct list_head *ws)
+{
+	btrfs_put_workspace(&heuristic_wsm, ws);
+}
+
 static void free_heuristic_ws(struct list_head *ws)
 {
 	struct heuristic_ws *workspace;
@@ -750,7 +796,7 @@
 	kfree(workspace);
 }
 
-static struct list_head *alloc_heuristic_ws(void)
+static struct list_head *alloc_heuristic_ws(unsigned int level)
 {
 	struct heuristic_ws *ws;
 
@@ -777,65 +823,59 @@
 	return ERR_PTR(-ENOMEM);
 }
 
-struct workspaces_list {
-	struct list_head idle_ws;
-	spinlock_t ws_lock;
-	/* Number of free workspaces */
-	int free_ws;
-	/* Total number of allocated workspaces */
-	atomic_t total_ws;
-	/* Waiters for a free workspace */
-	wait_queue_head_t ws_wait;
+const struct btrfs_compress_op btrfs_heuristic_compress = {
+	.init_workspace_manager = heuristic_init_workspace_manager,
+	.cleanup_workspace_manager = heuristic_cleanup_workspace_manager,
+	.get_workspace = heuristic_get_workspace,
+	.put_workspace = heuristic_put_workspace,
+	.alloc_workspace = alloc_heuristic_ws,
+	.free_workspace = free_heuristic_ws,
 };
 
-static struct workspaces_list btrfs_comp_ws[BTRFS_COMPRESS_TYPES];
-
-static struct workspaces_list btrfs_heuristic_ws;
-
 static const struct btrfs_compress_op * const btrfs_compress_op[] = {
+	/* The heuristic is represented as compression type 0 */
+	&btrfs_heuristic_compress,
 	&btrfs_zlib_compress,
 	&btrfs_lzo_compress,
 	&btrfs_zstd_compress,
 };
 
-void __init btrfs_init_compress(void)
+void btrfs_init_workspace_manager(struct workspace_manager *wsm,
+				  const struct btrfs_compress_op *ops)
 {
 	struct list_head *workspace;
-	int i;
 
-	INIT_LIST_HEAD(&btrfs_heuristic_ws.idle_ws);
-	spin_lock_init(&btrfs_heuristic_ws.ws_lock);
-	atomic_set(&btrfs_heuristic_ws.total_ws, 0);
-	init_waitqueue_head(&btrfs_heuristic_ws.ws_wait);
+	wsm->ops = ops;
 
-	workspace = alloc_heuristic_ws();
+	INIT_LIST_HEAD(&wsm->idle_ws);
+	spin_lock_init(&wsm->ws_lock);
+	atomic_set(&wsm->total_ws, 0);
+	init_waitqueue_head(&wsm->ws_wait);
+
+	/*
+	 * Preallocate one workspace for each compression type so we can
+	 * guarantee forward progress in the worst case
+	 */
+	workspace = wsm->ops->alloc_workspace(0);
 	if (IS_ERR(workspace)) {
 		pr_warn(
-	"BTRFS: cannot preallocate heuristic workspace, will try later\n");
+	"BTRFS: cannot preallocate compression workspace, will try later\n");
 	} else {
-		atomic_set(&btrfs_heuristic_ws.total_ws, 1);
-		btrfs_heuristic_ws.free_ws = 1;
-		list_add(workspace, &btrfs_heuristic_ws.idle_ws);
+		atomic_set(&wsm->total_ws, 1);
+		wsm->free_ws = 1;
+		list_add(workspace, &wsm->idle_ws);
 	}
+}
 
-	for (i = 0; i < BTRFS_COMPRESS_TYPES; i++) {
-		INIT_LIST_HEAD(&btrfs_comp_ws[i].idle_ws);
-		spin_lock_init(&btrfs_comp_ws[i].ws_lock);
-		atomic_set(&btrfs_comp_ws[i].total_ws, 0);
-		init_waitqueue_head(&btrfs_comp_ws[i].ws_wait);
+void btrfs_cleanup_workspace_manager(struct workspace_manager *wsman)
+{
+	struct list_head *ws;
 
-		/*
-		 * Preallocate one workspace for each compression type so
-		 * we can guarantee forward progress in the worst case
-		 */
-		workspace = btrfs_compress_op[i]->alloc_workspace();
-		if (IS_ERR(workspace)) {
-			pr_warn("BTRFS: cannot preallocate compression workspace, will try later\n");
-		} else {
-			atomic_set(&btrfs_comp_ws[i].total_ws, 1);
-			btrfs_comp_ws[i].free_ws = 1;
-			list_add(workspace, &btrfs_comp_ws[i].idle_ws);
-		}
+	while (!list_empty(&wsman->idle_ws)) {
+		ws = wsman->idle_ws.next;
+		list_del(ws);
+		wsman->ops->free_workspace(ws);
+		atomic_dec(&wsman->total_ws);
 	}
 }
 
@@ -845,11 +885,11 @@
  * Preallocation makes a forward progress guarantees and we do not return
  * errors.
  */
-static struct list_head *__find_workspace(int type, bool heuristic)
+struct list_head *btrfs_get_workspace(struct workspace_manager *wsm,
+				      unsigned int level)
 {
 	struct list_head *workspace;
 	int cpus = num_online_cpus();
-	int idx = type - 1;
 	unsigned nofs_flag;
 	struct list_head *idle_ws;
 	spinlock_t *ws_lock;
@@ -857,19 +897,11 @@
 	wait_queue_head_t *ws_wait;
 	int *free_ws;
 
-	if (heuristic) {
-		idle_ws	 = &btrfs_heuristic_ws.idle_ws;
-		ws_lock	 = &btrfs_heuristic_ws.ws_lock;
-		total_ws = &btrfs_heuristic_ws.total_ws;
-		ws_wait	 = &btrfs_heuristic_ws.ws_wait;
-		free_ws	 = &btrfs_heuristic_ws.free_ws;
-	} else {
-		idle_ws	 = &btrfs_comp_ws[idx].idle_ws;
-		ws_lock	 = &btrfs_comp_ws[idx].ws_lock;
-		total_ws = &btrfs_comp_ws[idx].total_ws;
-		ws_wait	 = &btrfs_comp_ws[idx].ws_wait;
-		free_ws	 = &btrfs_comp_ws[idx].free_ws;
-	}
+	idle_ws	 = &wsm->idle_ws;
+	ws_lock	 = &wsm->ws_lock;
+	total_ws = &wsm->total_ws;
+	ws_wait	 = &wsm->ws_wait;
+	free_ws	 = &wsm->free_ws;
 
 again:
 	spin_lock(ws_lock);
@@ -900,10 +932,7 @@
 	 * context of btrfs_compress_bio/btrfs_compress_pages
 	 */
 	nofs_flag = memalloc_nofs_save();
-	if (heuristic)
-		workspace = alloc_heuristic_ws();
-	else
-		workspace = btrfs_compress_op[idx]->alloc_workspace();
+	workspace = wsm->ops->alloc_workspace(level);
 	memalloc_nofs_restore(nofs_flag);
 
 	if (IS_ERR(workspace)) {
@@ -934,85 +963,47 @@
 	return workspace;
 }
 
-static struct list_head *find_workspace(int type)
+static struct list_head *get_workspace(int type, int level)
 {
-	return __find_workspace(type, false);
+	return btrfs_compress_op[type]->get_workspace(level);
 }
 
 /*
  * put a workspace struct back on the list or free it if we have enough
  * idle ones sitting around
  */
-static void __free_workspace(int type, struct list_head *workspace,
-			     bool heuristic)
+void btrfs_put_workspace(struct workspace_manager *wsm, struct list_head *ws)
 {
-	int idx = type - 1;
 	struct list_head *idle_ws;
 	spinlock_t *ws_lock;
 	atomic_t *total_ws;
 	wait_queue_head_t *ws_wait;
 	int *free_ws;
 
-	if (heuristic) {
-		idle_ws	 = &btrfs_heuristic_ws.idle_ws;
-		ws_lock	 = &btrfs_heuristic_ws.ws_lock;
-		total_ws = &btrfs_heuristic_ws.total_ws;
-		ws_wait	 = &btrfs_heuristic_ws.ws_wait;
-		free_ws	 = &btrfs_heuristic_ws.free_ws;
-	} else {
-		idle_ws	 = &btrfs_comp_ws[idx].idle_ws;
-		ws_lock	 = &btrfs_comp_ws[idx].ws_lock;
-		total_ws = &btrfs_comp_ws[idx].total_ws;
-		ws_wait	 = &btrfs_comp_ws[idx].ws_wait;
-		free_ws	 = &btrfs_comp_ws[idx].free_ws;
-	}
+	idle_ws	 = &wsm->idle_ws;
+	ws_lock	 = &wsm->ws_lock;
+	total_ws = &wsm->total_ws;
+	ws_wait	 = &wsm->ws_wait;
+	free_ws	 = &wsm->free_ws;
 
 	spin_lock(ws_lock);
 	if (*free_ws <= num_online_cpus()) {
-		list_add(workspace, idle_ws);
+		list_add(ws, idle_ws);
 		(*free_ws)++;
 		spin_unlock(ws_lock);
 		goto wake;
 	}
 	spin_unlock(ws_lock);
 
-	if (heuristic)
-		free_heuristic_ws(workspace);
-	else
-		btrfs_compress_op[idx]->free_workspace(workspace);
+	wsm->ops->free_workspace(ws);
 	atomic_dec(total_ws);
 wake:
 	cond_wake_up(ws_wait);
 }
 
-static void free_workspace(int type, struct list_head *ws)
+static void put_workspace(int type, struct list_head *ws)
 {
-	return __free_workspace(type, ws, false);
-}
-
-/*
- * cleanup function for module exit
- */
-static void free_workspaces(void)
-{
-	struct list_head *workspace;
-	int i;
-
-	while (!list_empty(&btrfs_heuristic_ws.idle_ws)) {
-		workspace = btrfs_heuristic_ws.idle_ws.next;
-		list_del(workspace);
-		free_heuristic_ws(workspace);
-		atomic_dec(&btrfs_heuristic_ws.total_ws);
-	}
-
-	for (i = 0; i < BTRFS_COMPRESS_TYPES; i++) {
-		while (!list_empty(&btrfs_comp_ws[i].idle_ws)) {
-			workspace = btrfs_comp_ws[i].idle_ws.next;
-			list_del(workspace);
-			btrfs_compress_op[i]->free_workspace(workspace);
-			atomic_dec(&btrfs_comp_ws[i].total_ws);
-		}
-	}
+	return btrfs_compress_op[type]->put_workspace(ws);
 }
 
 /*
@@ -1044,18 +1035,18 @@
 			 unsigned long *total_in,
 			 unsigned long *total_out)
 {
+	int type = btrfs_compress_type(type_level);
+	int level = btrfs_compress_level(type_level);
 	struct list_head *workspace;
 	int ret;
-	int type = type_level & 0xF;
 
-	workspace = find_workspace(type);
-
-	btrfs_compress_op[type - 1]->set_level(workspace, type_level);
-	ret = btrfs_compress_op[type-1]->compress_pages(workspace, mapping,
+	level = btrfs_compress_set_level(type, level);
+	workspace = get_workspace(type, level);
+	ret = btrfs_compress_op[type]->compress_pages(workspace, mapping,
 						      start, pages,
 						      out_pages,
 						      total_in, total_out);
-	free_workspace(type, workspace);
+	put_workspace(type, workspace);
 	return ret;
 }
 
@@ -1079,9 +1070,9 @@
 	int ret;
 	int type = cb->compress_type;
 
-	workspace = find_workspace(type);
-	ret = btrfs_compress_op[type - 1]->decompress_bio(workspace, cb);
-	free_workspace(type, workspace);
+	workspace = get_workspace(type, 0);
+	ret = btrfs_compress_op[type]->decompress_bio(workspace, cb);
+	put_workspace(type, workspace);
 
 	return ret;
 }
@@ -1097,19 +1088,29 @@
 	struct list_head *workspace;
 	int ret;
 
-	workspace = find_workspace(type);
-
-	ret = btrfs_compress_op[type-1]->decompress(workspace, data_in,
+	workspace = get_workspace(type, 0);
+	ret = btrfs_compress_op[type]->decompress(workspace, data_in,
 						  dest_page, start_byte,
 						  srclen, destlen);
+	put_workspace(type, workspace);
 
-	free_workspace(type, workspace);
 	return ret;
 }
 
+void __init btrfs_init_compress(void)
+{
+	int i;
+
+	for (i = 0; i < BTRFS_NR_WORKSPACE_MANAGERS; i++)
+		btrfs_compress_op[i]->init_workspace_manager();
+}
+
 void __cold btrfs_exit_compress(void)
 {
-	free_workspaces();
+	int i;
+
+	for (i = 0; i < BTRFS_NR_WORKSPACE_MANAGERS; i++)
+		btrfs_compress_op[i]->cleanup_workspace_manager();
 }
 
 /*
@@ -1211,7 +1212,7 @@
 /*
  * Shannon Entropy calculation
  *
- * Pure byte distribution analysis fails to determine compressiability of data.
+ * Pure byte distribution analysis fails to determine compressibility of data.
  * Try calculating entropy to estimate the average minimum number of bits
  * needed to encode the sampled data.
  *
@@ -1275,7 +1276,7 @@
 
 /*
  * Use 4 bits as radix base
- * Use 16 u32 counters for calculating new possition in buf array
+ * Use 16 u32 counters for calculating new position in buf array
  *
  * @array     - array that will be sorted
  * @array_buf - buffer array to store sorting results
@@ -1520,7 +1521,7 @@
  */
 int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end)
 {
-	struct list_head *ws_list = __find_workspace(0, true);
+	struct list_head *ws_list = get_workspace(0, 0);
 	struct heuristic_ws *ws;
 	u32 i;
 	u8 byte;
@@ -1589,18 +1590,45 @@
 	}
 
 out:
-	__free_workspace(0, ws_list, true);
+	put_workspace(0, ws_list);
 	return ret;
 }
 
-unsigned int btrfs_compress_str2level(const char *str)
+/*
+ * Convert the compression suffix (eg. after "zlib" starting with ":") to
+ * level, unrecognized string will set the default level
+ */
+unsigned int btrfs_compress_str2level(unsigned int type, const char *str)
 {
-	if (strncmp(str, "zlib", 4) != 0)
+	unsigned int level = 0;
+	int ret;
+
+	if (!type)
 		return 0;
 
-	/* Accepted form: zlib:1 up to zlib:9 and nothing left after the number */
-	if (str[4] == ':' && '1' <= str[5] && str[5] <= '9' && str[6] == 0)
-		return str[5] - '0';
+	if (str[0] == ':') {
+		ret = kstrtouint(str + 1, 10, &level);
+		if (ret)
+			level = 0;
+	}
 
-	return BTRFS_ZLIB_DEFAULT_LEVEL;
+	level = btrfs_compress_set_level(type, level);
+
+	return level;
+}
+
+/*
+ * Adjust @level according to the limits of the compression algorithm or
+ * fallback to default
+ */
+unsigned int btrfs_compress_set_level(int type, unsigned level)
+{
+	const struct btrfs_compress_op *ops = btrfs_compress_op[type];
+
+	if (level == 0)
+		level = ops->default_level;
+	else
+		level = min(level, ops->max_level);
+
+	return level;
 }
diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
index ddda9b8..4cb8be9 100644
--- a/fs/btrfs/compression.h
+++ b/fs/btrfs/compression.h
@@ -61,9 +61,19 @@
 	 * the start of a variable length array of checksums only
 	 * used by reads
 	 */
-	u32 sums;
+	u8 sums[];
 };
 
+static inline unsigned int btrfs_compress_type(unsigned int type_level)
+{
+	return (type_level & 0xF);
+}
+
+static inline unsigned int btrfs_compress_level(unsigned int type_level)
+{
+	return ((type_level & 0xF0) >> 4);
+}
+
 void __init btrfs_init_compress(void);
 void __cold btrfs_exit_compress(void);
 
@@ -87,7 +97,7 @@
 blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 				 int mirror_num, unsigned long bio_flags);
 
-unsigned btrfs_compress_str2level(const char *str);
+unsigned int btrfs_compress_str2level(unsigned int type, const char *str);
 
 enum btrfs_compression_type {
 	BTRFS_COMPRESS_NONE  = 0,
@@ -97,8 +107,35 @@
 	BTRFS_COMPRESS_TYPES = 3,
 };
 
+struct workspace_manager {
+	const struct btrfs_compress_op *ops;
+	struct list_head idle_ws;
+	spinlock_t ws_lock;
+	/* Number of free workspaces */
+	int free_ws;
+	/* Total number of allocated workspaces */
+	atomic_t total_ws;
+	/* Waiters for a free workspace */
+	wait_queue_head_t ws_wait;
+};
+
+void btrfs_init_workspace_manager(struct workspace_manager *wsm,
+				  const struct btrfs_compress_op *ops);
+struct list_head *btrfs_get_workspace(struct workspace_manager *wsm,
+				      unsigned int level);
+void btrfs_put_workspace(struct workspace_manager *wsm, struct list_head *ws);
+void btrfs_cleanup_workspace_manager(struct workspace_manager *wsm);
+
 struct btrfs_compress_op {
-	struct list_head *(*alloc_workspace)(void);
+	void (*init_workspace_manager)(void);
+
+	void (*cleanup_workspace_manager)(void);
+
+	struct list_head *(*get_workspace)(unsigned int level);
+
+	void (*put_workspace)(struct list_head *ws);
+
+	struct list_head *(*alloc_workspace)(unsigned int level);
 
 	void (*free_workspace)(struct list_head *workspace);
 
@@ -119,14 +156,23 @@
 			  unsigned long start_byte,
 			  size_t srclen, size_t destlen);
 
-	void (*set_level)(struct list_head *ws, unsigned int type);
+	/* Maximum level supported by the compression algorithm */
+	unsigned int max_level;
+	unsigned int default_level;
 };
 
+/* The heuristic workspaces are managed via the 0th workspace manager */
+#define BTRFS_NR_WORKSPACE_MANAGERS	(BTRFS_COMPRESS_TYPES + 1)
+
+extern const struct btrfs_compress_op btrfs_heuristic_compress;
 extern const struct btrfs_compress_op btrfs_zlib_compress;
 extern const struct btrfs_compress_op btrfs_lzo_compress;
 extern const struct btrfs_compress_op btrfs_zstd_compress;
 
 const char* btrfs_compress_type2str(enum btrfs_compression_type type);
+bool btrfs_compress_is_valid_type(const char *str, size_t len);
+
+unsigned int btrfs_compress_set_level(int type, unsigned level);
 
 int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end);
 
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 089b46c..e59cde2 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -12,6 +12,8 @@
 #include "transaction.h"
 #include "print-tree.h"
 #include "locking.h"
+#include "volumes.h"
+#include "qgroup.h"
 
 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
 		      *root, struct btrfs_path *path, int level);
@@ -19,16 +21,36 @@
 		      const struct btrfs_key *ins_key, struct btrfs_path *path,
 		      int data_size, int extend);
 static int push_node_left(struct btrfs_trans_handle *trans,
-			  struct btrfs_fs_info *fs_info,
 			  struct extent_buffer *dst,
 			  struct extent_buffer *src, int empty);
 static int balance_node_right(struct btrfs_trans_handle *trans,
-			      struct btrfs_fs_info *fs_info,
 			      struct extent_buffer *dst_buf,
 			      struct extent_buffer *src_buf);
 static void del_ptr(struct btrfs_root *root, struct btrfs_path *path,
 		    int level, int slot);
 
+static const struct btrfs_csums {
+	u16		size;
+	const char	*name;
+} btrfs_csums[] = {
+	[BTRFS_CSUM_TYPE_CRC32] = { .size = 4, .name = "crc32c" },
+};
+
+int btrfs_super_csum_size(const struct btrfs_super_block *s)
+{
+	u16 t = btrfs_super_csum_type(s);
+	/*
+	 * csum type is validated at mount time
+	 */
+	return btrfs_csums[t].size;
+}
+
+const char *btrfs_super_csum_name(u16 csum_type)
+{
+	/* csum type is validated at mount time */
+	return btrfs_csums[csum_type].name;
+}
+
 struct btrfs_path *btrfs_alloc_path(void)
 {
 	return kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS);
@@ -44,48 +66,19 @@
 	for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
 		if (!p->nodes[i] || !p->locks[i])
 			continue;
-		btrfs_set_lock_blocking_rw(p->nodes[i], p->locks[i]);
-		if (p->locks[i] == BTRFS_READ_LOCK)
+		/*
+		 * If we currently have a spinning reader or writer lock this
+		 * will bump the count of blocking holders and drop the
+		 * spinlock.
+		 */
+		if (p->locks[i] == BTRFS_READ_LOCK) {
+			btrfs_set_lock_blocking_read(p->nodes[i]);
 			p->locks[i] = BTRFS_READ_LOCK_BLOCKING;
-		else if (p->locks[i] == BTRFS_WRITE_LOCK)
+		} else if (p->locks[i] == BTRFS_WRITE_LOCK) {
+			btrfs_set_lock_blocking_write(p->nodes[i]);
 			p->locks[i] = BTRFS_WRITE_LOCK_BLOCKING;
-	}
-}
-
-/*
- * reset all the locked nodes in the patch to spinning locks.
- *
- * held is used to keep lockdep happy, when lockdep is enabled
- * we set held to a blocking lock before we go around and
- * retake all the spinlocks in the path.  You can safely use NULL
- * for held
- */
-noinline void btrfs_clear_path_blocking(struct btrfs_path *p,
-					struct extent_buffer *held, int held_rw)
-{
-	int i;
-
-	if (held) {
-		btrfs_set_lock_blocking_rw(held, held_rw);
-		if (held_rw == BTRFS_WRITE_LOCK)
-			held_rw = BTRFS_WRITE_LOCK_BLOCKING;
-		else if (held_rw == BTRFS_READ_LOCK)
-			held_rw = BTRFS_READ_LOCK_BLOCKING;
-	}
-	btrfs_set_path_blocking(p);
-
-	for (i = BTRFS_MAX_LEVEL - 1; i >= 0; i--) {
-		if (p->nodes[i] && p->locks[i]) {
-			btrfs_clear_lock_blocking_rw(p->nodes[i], p->locks[i]);
-			if (p->locks[i] == BTRFS_WRITE_LOCK_BLOCKING)
-				p->locks[i] = BTRFS_WRITE_LOCK;
-			else if (p->locks[i] == BTRFS_READ_LOCK_BLOCKING)
-				p->locks[i] = BTRFS_READ_LOCK;
 		}
 	}
-
-	if (held)
-		btrfs_clear_lock_blocking_rw(held, held_rw);
 }
 
 /* this also releases the path */
@@ -207,7 +200,7 @@
 	spin_lock(&fs_info->trans_lock);
 	if (!test_and_set_bit(BTRFS_ROOT_DIRTY, &root->state)) {
 		/* Want the extent tree to be the last on the list */
-		if (root->objectid == BTRFS_EXTENT_TREE_OBJECTID)
+		if (root->root_key.objectid == BTRFS_EXTENT_TREE_OBJECTID)
 			list_move_tail(&root->dirty_list,
 				       &fs_info->dirty_cowonly_roots);
 		else
@@ -260,7 +253,7 @@
 	else
 		btrfs_set_header_owner(cow, new_root_objectid);
 
-	write_extent_buffer_fsid(cow, fs_info->fsid);
+	write_extent_buffer_fsid(cow, fs_info->fs_devices->metadata_uuid);
 
 	WARN_ON(btrfs_header_generation(buf) > trans->transid);
 	if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID)
@@ -405,8 +398,6 @@
  * The 'start address' is the logical address of the *new* root node
  * for root replace operations, or the logical address of the affected
  * block for all other operations.
- *
- * Note: must be called with write lock for fs_info::tree_mod_log_lock.
  */
 static noinline int
 __tree_mod_log_insert(struct btrfs_fs_info *fs_info, struct tree_mod_elem *tm)
@@ -416,6 +407,8 @@
 	struct rb_node *parent = NULL;
 	struct tree_mod_elem *cur;
 
+	lockdep_assert_held_write(&fs_info->tree_mod_log_lock);
+
 	tm->seq = btrfs_inc_tree_mod_seq(fs_info);
 
 	tm_root = &fs_info->tree_mod_log;
@@ -753,11 +746,11 @@
 	return __tree_mod_log_search(fs_info, start, min_seq, 0);
 }
 
-static noinline int
-tree_mod_log_eb_copy(struct btrfs_fs_info *fs_info, struct extent_buffer *dst,
+static noinline int tree_mod_log_eb_copy(struct extent_buffer *dst,
 		     struct extent_buffer *src, unsigned long dst_offset,
 		     unsigned long src_offset, int nr_items)
 {
+	struct btrfs_fs_info *fs_info = dst->fs_info;
 	int ret = 0;
 	struct tree_mod_elem **tm_list = NULL;
 	struct tree_mod_elem **tm_list_add, **tm_list_rem;
@@ -977,7 +970,7 @@
 		if (new_flags != 0) {
 			int level = btrfs_header_level(buf);
 
-			ret = btrfs_set_disk_extent_flags(trans, fs_info,
+			ret = btrfs_set_disk_extent_flags(trans,
 							  buf->start,
 							  buf->len,
 							  new_flags, level, 0);
@@ -997,12 +990,54 @@
 			if (ret)
 				return ret;
 		}
-		clean_tree_block(fs_info, buf);
+		btrfs_clean_tree_block(buf);
 		*last_ref = 1;
 	}
 	return 0;
 }
 
+static struct extent_buffer *alloc_tree_block_no_bg_flush(
+					  struct btrfs_trans_handle *trans,
+					  struct btrfs_root *root,
+					  u64 parent_start,
+					  const struct btrfs_disk_key *disk_key,
+					  int level,
+					  u64 hint,
+					  u64 empty_size)
+{
+	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct extent_buffer *ret;
+
+	/*
+	 * If we are COWing a node/leaf from the extent, chunk, device or free
+	 * space trees, make sure that we do not finish block group creation of
+	 * pending block groups. We do this to avoid a deadlock.
+	 * COWing can result in allocation of a new chunk, and flushing pending
+	 * block groups (btrfs_create_pending_block_groups()) can be triggered
+	 * when finishing allocation of a new chunk. Creation of a pending block
+	 * group modifies the extent, chunk, device and free space trees,
+	 * therefore we could deadlock with ourselves since we are holding a
+	 * lock on an extent buffer that btrfs_create_pending_block_groups() may
+	 * try to COW later.
+	 * For similar reasons, we also need to delay flushing pending block
+	 * groups when splitting a leaf or node, from one of those trees, since
+	 * we are holding a write lock on it and its parent or when inserting a
+	 * new root node for one of those trees.
+	 */
+	if (root == fs_info->extent_root ||
+	    root == fs_info->chunk_root ||
+	    root == fs_info->dev_root ||
+	    root == fs_info->free_space_root)
+		trans->can_flush_pending_bgs = false;
+
+	ret = btrfs_alloc_tree_block(trans, root, parent_start,
+				     root->root_key.objectid, disk_key, level,
+				     hint, empty_size);
+	trans->can_flush_pending_bgs = true;
+
+	return ret;
+}
+
 /*
  * does the dirty work in cow of a single block.  The parent block (if
  * supplied) is updated to point to the new cow copy.  The new buffer is marked
@@ -1050,26 +1085,8 @@
 	if ((root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && parent)
 		parent_start = parent->start;
 
-	/*
-	 * If we are COWing a node/leaf from the extent, chunk or device trees,
-	 * make sure that we do not finish block group creation of pending block
-	 * groups. We do this to avoid a deadlock.
-	 * COWing can result in allocation of a new chunk, and flushing pending
-	 * block groups (btrfs_create_pending_block_groups()) can be triggered
-	 * when finishing allocation of a new chunk. Creation of a pending block
-	 * group modifies the extent, chunk and device trees, therefore we could
-	 * deadlock with ourselves since we are holding a lock on an extent
-	 * buffer that btrfs_create_pending_block_groups() may try to COW later.
-	 */
-	if (root == fs_info->extent_root ||
-	    root == fs_info->chunk_root ||
-	    root == fs_info->dev_root)
-		trans->can_flush_pending_bgs = false;
-
-	cow = btrfs_alloc_tree_block(trans, root, parent_start,
-			root->root_key.objectid, &disk_key, level,
-			search_start, empty_size);
-	trans->can_flush_pending_bgs = true;
+	cow = alloc_tree_block_no_bg_flush(trans, root, parent_start, &disk_key,
+					   level, search_start, empty_size);
 	if (IS_ERR(cow))
 		return PTR_ERR(cow);
 
@@ -1086,7 +1103,7 @@
 	else
 		btrfs_set_header_owner(cow, root->root_key.objectid);
 
-	write_extent_buffer_fsid(cow, fs_info->fsid);
+	write_extent_buffer_fsid(cow, fs_info->fs_devices->metadata_uuid);
 
 	ret = update_ref_for_cow(trans, root, buf, cow, &last_ref);
 	if (ret) {
@@ -1299,7 +1316,7 @@
 		return eb;
 
 	btrfs_set_path_blocking(path);
-	btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
+	btrfs_set_lock_blocking_read(eb);
 
 	if (tm->op == MOD_LOG_KEY_REMOVE_WHILE_FREEING) {
 		BUG_ON(tm->slot != 0);
@@ -1323,11 +1340,9 @@
 		}
 	}
 
-	btrfs_clear_path_blocking(path, NULL, BTRFS_READ_LOCK);
 	btrfs_tree_read_unlock_blocking(eb);
 	free_extent_buffer(eb);
 
-	extent_buffer_get(eb_rewin);
 	btrfs_tree_read_lock(eb_rewin);
 	__tree_mod_log_rewind(fs_info, eb_rewin, time_seq, tm);
 	WARN_ON(btrfs_header_nritems(eb_rewin) >
@@ -1350,6 +1365,7 @@
 	struct tree_mod_elem *tm;
 	struct extent_buffer *eb = NULL;
 	struct extent_buffer *eb_root;
+	u64 eb_root_owner = 0;
 	struct extent_buffer *old;
 	struct tree_mod_root *old_root = NULL;
 	u64 old_generation = 0;
@@ -1387,11 +1403,12 @@
 			free_extent_buffer(old);
 		}
 	} else if (old_root) {
+		eb_root_owner = btrfs_header_owner(eb_root);
 		btrfs_tree_read_unlock(eb_root);
 		free_extent_buffer(eb_root);
 		eb = alloc_dummy_extent_buffer(fs_info, logical);
 	} else {
-		btrfs_set_lock_blocking_rw(eb_root, BTRFS_READ_LOCK);
+		btrfs_set_lock_blocking_read(eb_root);
 		eb = btrfs_clone_extent_buffer(eb_root);
 		btrfs_tree_read_unlock_blocking(eb_root);
 		free_extent_buffer(eb_root);
@@ -1399,12 +1416,11 @@
 
 	if (!eb)
 		return NULL;
-	extent_buffer_get(eb);
 	btrfs_tree_read_lock(eb);
 	if (old_root) {
 		btrfs_set_header_bytenr(eb, eb->start);
 		btrfs_set_header_backref_rev(eb, BTRFS_MIXED_BACKREF_REV);
-		btrfs_set_header_owner(eb, btrfs_header_owner(eb_root));
+		btrfs_set_header_owner(eb, eb_root_owner);
 		btrfs_set_header_level(eb, old_root->level);
 		btrfs_set_header_generation(eb, old_generation);
 	}
@@ -1452,7 +1468,7 @@
 	 *
 	 * What is forced COW:
 	 *    when we create snapshot during committing the transaction,
-	 *    after we've finished coping src root, we must COW the shared
+	 *    after we've finished copying src root, we must COW the shared
 	 *    block to ensure the metadata consistency.
 	 */
 	if (btrfs_header_generation(buf) == trans->transid &&
@@ -1478,6 +1494,10 @@
 	u64 search_start;
 	int ret;
 
+	if (test_bit(BTRFS_ROOT_DELETING, &root->state))
+		btrfs_err(fs_info,
+			"COW'ing blocks on a fs root that's being dropped");
+
 	if (trans->transaction != fs_info->running_transaction)
 		WARN(1, KERN_CRIT "trans %llu running %llu\n",
 		       trans->transid,
@@ -1496,9 +1516,16 @@
 	search_start = buf->start & ~((u64)SZ_1G - 1);
 
 	if (parent)
-		btrfs_set_lock_blocking(parent);
-	btrfs_set_lock_blocking(buf);
+		btrfs_set_lock_blocking_write(parent);
+	btrfs_set_lock_blocking_write(buf);
 
+	/*
+	 * Before CoWing this block for later modification, check if it's
+	 * the subtree root and do the delayed subtree trace if needed.
+	 *
+	 * Also We don't care about the error, as it's handled internally.
+	 */
+	btrfs_qgroup_trace_subtree_after_cow(trans, root, buf);
 	ret = __btrfs_cow_block(trans, root, buf, parent,
 				 parent_slot, cow_ret, search_start, 0);
 
@@ -1592,7 +1619,7 @@
 	if (parent_nritems <= 1)
 		return 0;
 
-	btrfs_set_lock_blocking(parent);
+	btrfs_set_lock_blocking_write(parent);
 
 	for (i = start_slot; i <= end_slot; i++) {
 		struct btrfs_key first_key;
@@ -1651,7 +1678,7 @@
 			search_start = last_block;
 
 		btrfs_tree_lock(cur);
-		btrfs_set_lock_blocking(cur);
+		btrfs_set_lock_blocking_write(cur);
 		err = __btrfs_cow_block(trans, root, cur, parent, i,
 					&cur, search_start,
 					min(16 * blocksize,
@@ -1787,9 +1814,8 @@
 /* given a node and slot number, this reads the blocks it points to.  The
  * extent buffer is returned with a reference taken (but unlocked).
  */
-static noinline struct extent_buffer *
-read_node_slot(struct btrfs_fs_info *fs_info, struct extent_buffer *parent,
-	       int slot)
+struct extent_buffer *btrfs_read_node_slot(struct extent_buffer *parent,
+					   int slot)
 {
 	int level = btrfs_header_level(parent);
 	struct extent_buffer *eb;
@@ -1801,7 +1827,7 @@
 	BUG_ON(level == 0);
 
 	btrfs_node_key_to_cpu(parent, &first_key, slot);
-	eb = read_tree_block(fs_info, btrfs_node_blockptr(parent, slot),
+	eb = read_tree_block(parent->fs_info, btrfs_node_blockptr(parent, slot),
 			     btrfs_node_ptr_generation(parent, slot),
 			     level - 1, &first_key);
 	if (!IS_ERR(eb) && !extent_buffer_uptodate(eb)) {
@@ -1832,8 +1858,7 @@
 	int orig_slot = path->slots[level];
 	u64 orig_ptr;
 
-	if (level == 0)
-		return 0;
+	ASSERT(level > 0);
 
 	mid = path->nodes[level];
 
@@ -1859,7 +1884,7 @@
 			return 0;
 
 		/* promote the child to a root */
-		child = read_node_slot(fs_info, mid, 0);
+		child = btrfs_read_node_slot(mid, 0);
 		if (IS_ERR(child)) {
 			ret = PTR_ERR(child);
 			btrfs_handle_fs_error(fs_info, ret, NULL);
@@ -1867,7 +1892,7 @@
 		}
 
 		btrfs_tree_lock(child);
-		btrfs_set_lock_blocking(child);
+		btrfs_set_lock_blocking_write(child);
 		ret = btrfs_cow_block(trans, root, child, mid, 0, &child);
 		if (ret) {
 			btrfs_tree_unlock(child);
@@ -1884,7 +1909,7 @@
 
 		path->locks[level] = 0;
 		path->nodes[level] = NULL;
-		clean_tree_block(fs_info, mid);
+		btrfs_clean_tree_block(mid);
 		btrfs_tree_unlock(mid);
 		/* once for the path */
 		free_extent_buffer(mid);
@@ -1899,13 +1924,13 @@
 	    BTRFS_NODEPTRS_PER_BLOCK(fs_info) / 4)
 		return 0;
 
-	left = read_node_slot(fs_info, parent, pslot - 1);
+	left = btrfs_read_node_slot(parent, pslot - 1);
 	if (IS_ERR(left))
 		left = NULL;
 
 	if (left) {
 		btrfs_tree_lock(left);
-		btrfs_set_lock_blocking(left);
+		btrfs_set_lock_blocking_write(left);
 		wret = btrfs_cow_block(trans, root, left,
 				       parent, pslot - 1, &left);
 		if (wret) {
@@ -1914,13 +1939,13 @@
 		}
 	}
 
-	right = read_node_slot(fs_info, parent, pslot + 1);
+	right = btrfs_read_node_slot(parent, pslot + 1);
 	if (IS_ERR(right))
 		right = NULL;
 
 	if (right) {
 		btrfs_tree_lock(right);
-		btrfs_set_lock_blocking(right);
+		btrfs_set_lock_blocking_write(right);
 		wret = btrfs_cow_block(trans, root, right,
 				       parent, pslot + 1, &right);
 		if (wret) {
@@ -1932,7 +1957,7 @@
 	/* first, try to make some room in the middle buffer */
 	if (left) {
 		orig_slot += btrfs_header_nritems(left);
-		wret = push_node_left(trans, fs_info, left, mid, 1);
+		wret = push_node_left(trans, left, mid, 1);
 		if (wret < 0)
 			ret = wret;
 	}
@@ -1941,11 +1966,11 @@
 	 * then try to empty the right most buffer into the middle
 	 */
 	if (right) {
-		wret = push_node_left(trans, fs_info, mid, right, 1);
+		wret = push_node_left(trans, mid, right, 1);
 		if (wret < 0 && wret != -ENOSPC)
 			ret = wret;
 		if (btrfs_header_nritems(right) == 0) {
-			clean_tree_block(fs_info, right);
+			btrfs_clean_tree_block(right);
 			btrfs_tree_unlock(right);
 			del_ptr(root, path, level + 1, pslot + 1);
 			root_sub_used(root, right->len);
@@ -1977,20 +2002,20 @@
 			btrfs_handle_fs_error(fs_info, ret, NULL);
 			goto enospc;
 		}
-		wret = balance_node_right(trans, fs_info, mid, left);
+		wret = balance_node_right(trans, mid, left);
 		if (wret < 0) {
 			ret = wret;
 			goto enospc;
 		}
 		if (wret == 1) {
-			wret = push_node_left(trans, fs_info, left, mid, 1);
+			wret = push_node_left(trans, left, mid, 1);
 			if (wret < 0)
 				ret = wret;
 		}
 		BUG_ON(wret == 1);
 	}
 	if (btrfs_header_nritems(mid) == 0) {
-		clean_tree_block(fs_info, mid);
+		btrfs_clean_tree_block(mid);
 		btrfs_tree_unlock(mid);
 		del_ptr(root, path, level + 1, pslot);
 		root_sub_used(root, mid->len);
@@ -2074,7 +2099,7 @@
 	if (!parent)
 		return 1;
 
-	left = read_node_slot(fs_info, parent, pslot - 1);
+	left = btrfs_read_node_slot(parent, pslot - 1);
 	if (IS_ERR(left))
 		left = NULL;
 
@@ -2083,7 +2108,7 @@
 		u32 left_nr;
 
 		btrfs_tree_lock(left);
-		btrfs_set_lock_blocking(left);
+		btrfs_set_lock_blocking_write(left);
 
 		left_nr = btrfs_header_nritems(left);
 		if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 1) {
@@ -2094,8 +2119,7 @@
 			if (ret)
 				wret = 1;
 			else {
-				wret = push_node_left(trans, fs_info,
-						      left, mid, 0);
+				wret = push_node_left(trans, left, mid, 0);
 			}
 		}
 		if (wret < 0)
@@ -2127,7 +2151,7 @@
 		btrfs_tree_unlock(left);
 		free_extent_buffer(left);
 	}
-	right = read_node_slot(fs_info, parent, pslot + 1);
+	right = btrfs_read_node_slot(parent, pslot + 1);
 	if (IS_ERR(right))
 		right = NULL;
 
@@ -2138,7 +2162,7 @@
 		u32 right_nr;
 
 		btrfs_tree_lock(right);
-		btrfs_set_lock_blocking(right);
+		btrfs_set_lock_blocking_write(right);
 
 		right_nr = btrfs_header_nritems(right);
 		if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 1) {
@@ -2150,8 +2174,7 @@
 			if (ret)
 				wret = 1;
 			else {
-				wret = balance_node_right(trans, fs_info,
-							  right, mid);
+				wret = balance_node_right(trans, right, mid);
 			}
 		}
 		if (wret < 0)
@@ -2412,6 +2435,16 @@
 	if (tmp) {
 		/* first we do an atomic uptodate check */
 		if (btrfs_buffer_uptodate(tmp, gen, 1) > 0) {
+			/*
+			 * Do extra check for first_key, eb can be stale due to
+			 * being cached, read from scrub, or have multiple
+			 * parents (shared tree blocks).
+			 */
+			if (btrfs_verify_level_key(tmp,
+					parent_level - 1, &first_key, gen)) {
+				free_extent_buffer(tmp);
+				return -EUCLEAN;
+			}
 			*eb_ret = tmp;
 			return 0;
 		}
@@ -2500,7 +2533,6 @@
 		btrfs_set_path_blocking(p);
 		reada_for_balance(fs_info, p, level);
 		sret = split_node(trans, root, p, level);
-		btrfs_clear_path_blocking(p, NULL, 0);
 
 		BUG_ON(sret > 0);
 		if (sret) {
@@ -2521,7 +2553,6 @@
 		btrfs_set_path_blocking(p);
 		reada_for_balance(fs_info, p, level);
 		sret = balance_level(trans, root, p, level);
-		btrfs_clear_path_blocking(p, NULL, 0);
 
 		if (sret) {
 			ret = sret;
@@ -2542,26 +2573,6 @@
 	return ret;
 }
 
-static void key_search_validate(struct extent_buffer *b,
-				const struct btrfs_key *key,
-				int level)
-{
-#ifdef CONFIG_BTRFS_ASSERT
-	struct btrfs_disk_key disk_key;
-
-	btrfs_cpu_key_to_disk(&disk_key, key);
-
-	if (level == 0)
-		ASSERT(!memcmp_extent_buffer(b, &disk_key,
-		    offsetof(struct btrfs_leaf, items[0].key),
-		    sizeof(disk_key)));
-	else
-		ASSERT(!memcmp_extent_buffer(b, &disk_key,
-		    offsetof(struct btrfs_node, ptrs[0].key),
-		    sizeof(disk_key)));
-#endif
-}
-
 static int key_search(struct extent_buffer *b, const struct btrfs_key *key,
 		      int level, int *prev_cmp, int *slot)
 {
@@ -2570,7 +2581,6 @@
 		return *prev_cmp;
 	}
 
-	key_search_validate(b, key, level);
 	*slot = 0;
 
 	return 0;
@@ -2624,14 +2634,27 @@
 	root_lock = BTRFS_READ_LOCK;
 
 	if (p->search_commit_root) {
-		/* The commit roots are read only so we always do read locks */
-		if (p->need_commit_sem)
+		/*
+		 * The commit roots are read only so we always do read locks,
+		 * and we always must hold the commit_root_sem when doing
+		 * searches on them, the only exception is send where we don't
+		 * want to block transaction commits for a long time, so
+		 * we need to clone the commit root in order to avoid races
+		 * with transaction commits that create a snapshot of one of
+		 * the roots used by a send operation.
+		 */
+		if (p->need_commit_sem) {
 			down_read(&fs_info->commit_root_sem);
-		b = root->commit_root;
-		extent_buffer_get(b);
-		level = btrfs_header_level(b);
-		if (p->need_commit_sem)
+			b = btrfs_clone_extent_buffer(root->commit_root);
 			up_read(&fs_info->commit_root_sem);
+			if (!b)
+				return ERR_PTR(-ENOMEM);
+
+		} else {
+			b = root->commit_root;
+			extent_buffer_get(b);
+		}
+		level = btrfs_header_level(b);
 		/*
 		 * Ensure that all callers have set skip_locking when
 		 * p->search_commit_root = 1.
@@ -2712,7 +2735,6 @@
 		      const struct btrfs_key *key, struct btrfs_path *p,
 		      int ins_len, int cow)
 {
-	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct extent_buffer *b;
 	int slot;
 	int ret;
@@ -2757,6 +2779,10 @@
 again:
 	prev_cmp = -1;
 	b = btrfs_search_slot_get_root(root, p, write_lock_level);
+	if (IS_ERR(b)) {
+		ret = PTR_ERR(b);
+		goto done;
+	}
 
 	while (b) {
 		level = btrfs_header_level(b);
@@ -2806,7 +2832,10 @@
 		}
 cow_done:
 		p->nodes[level] = b;
-		btrfs_clear_path_blocking(p, NULL, 0);
+		/*
+		 * Leave path with blocking locks to avoid massive
+		 * lock context switch, this is made on purpose.
+		 */
 
 		/*
 		 * we have a lock on b and as long as we aren't changing
@@ -2884,21 +2913,15 @@
 			if (!p->skip_locking) {
 				level = btrfs_header_level(b);
 				if (level <= write_lock_level) {
-					err = btrfs_try_tree_write_lock(b);
-					if (!err) {
+					if (!btrfs_try_tree_write_lock(b)) {
 						btrfs_set_path_blocking(p);
 						btrfs_tree_lock(b);
-						btrfs_clear_path_blocking(p, b,
-								  BTRFS_WRITE_LOCK);
 					}
 					p->locks[level] = BTRFS_WRITE_LOCK;
 				} else {
-					err = btrfs_tree_read_lock_atomic(b);
-					if (!err) {
+					if (!btrfs_tree_read_lock_atomic(b)) {
 						btrfs_set_path_blocking(p);
 						btrfs_tree_read_lock(b);
-						btrfs_clear_path_blocking(p, b,
-								  BTRFS_READ_LOCK);
 					}
 					p->locks[level] = BTRFS_READ_LOCK;
 				}
@@ -2907,7 +2930,7 @@
 		} else {
 			p->slots[level] = slot;
 			if (ins_len > 0 &&
-			    btrfs_leaf_free_space(fs_info, b) < ins_len) {
+			    btrfs_leaf_free_space(b) < ins_len) {
 				if (write_lock_level < 1) {
 					write_lock_level = 1;
 					btrfs_release_path(p);
@@ -2917,7 +2940,6 @@
 				btrfs_set_path_blocking(p);
 				err = split_leaf(trans, root, key,
 						 p, ins_len, ret == 0);
-				btrfs_clear_path_blocking(p, NULL, 0);
 
 				BUG_ON(err > 0);
 				if (err) {
@@ -2927,7 +2949,7 @@
 			}
 			if (!p->search_for_split)
 				unlock_up(p, level, lowest_unlock,
-					  min_write_lock_level, &write_lock_level);
+					  min_write_lock_level, NULL);
 			goto done;
 		}
 	}
@@ -2978,13 +3000,16 @@
 
 again:
 	b = get_old_root(root, time_seq);
+	if (!b) {
+		ret = -EIO;
+		goto done;
+	}
 	level = btrfs_header_level(b);
 	p->locks[level] = BTRFS_READ_LOCK;
 
 	while (b) {
 		level = btrfs_header_level(b);
 		p->nodes[level] = b;
-		btrfs_clear_path_blocking(p, NULL, 0);
 
 		/*
 		 * we have a lock on b and as long as we aren't changing
@@ -3000,6 +3025,8 @@
 		 */
 		prev_cmp = -1;
 		ret = key_search(b, key, level, &prev_cmp, &slot);
+		if (ret < 0)
+			goto done;
 
 		if (level != 0) {
 			int dec = 0;
@@ -3026,12 +3053,9 @@
 			}
 
 			level = btrfs_header_level(b);
-			err = btrfs_tree_read_lock_atomic(b);
-			if (!err) {
+			if (!btrfs_tree_read_lock_atomic(b)) {
 				btrfs_set_path_blocking(p);
 				btrfs_tree_read_lock(b);
-				btrfs_clear_path_blocking(p, b,
-							  BTRFS_READ_LOCK);
 			}
 			b = tree_mod_log_rewind(fs_info, p, b, time_seq);
 			if (!b) {
@@ -3182,11 +3206,31 @@
 	slot = path->slots[0];
 	if (slot > 0) {
 		btrfs_item_key(eb, &disk_key, slot - 1);
-		BUG_ON(comp_keys(&disk_key, new_key) >= 0);
+		if (unlikely(comp_keys(&disk_key, new_key) >= 0)) {
+			btrfs_crit(fs_info,
+		"slot %u key (%llu %u %llu) new key (%llu %u %llu)",
+				   slot, btrfs_disk_key_objectid(&disk_key),
+				   btrfs_disk_key_type(&disk_key),
+				   btrfs_disk_key_offset(&disk_key),
+				   new_key->objectid, new_key->type,
+				   new_key->offset);
+			btrfs_print_leaf(eb);
+			BUG();
+		}
 	}
 	if (slot < btrfs_header_nritems(eb) - 1) {
 		btrfs_item_key(eb, &disk_key, slot + 1);
-		BUG_ON(comp_keys(&disk_key, new_key) <= 0);
+		if (unlikely(comp_keys(&disk_key, new_key) <= 0)) {
+			btrfs_crit(fs_info,
+		"slot %u key (%llu %u %llu) new key (%llu %u %llu)",
+				   slot, btrfs_disk_key_objectid(&disk_key),
+				   btrfs_disk_key_type(&disk_key),
+				   btrfs_disk_key_offset(&disk_key),
+				   new_key->objectid, new_key->type,
+				   new_key->offset);
+			btrfs_print_leaf(eb);
+			BUG();
+		}
 	}
 
 	btrfs_cpu_key_to_disk(&disk_key, new_key);
@@ -3204,10 +3248,10 @@
  * error, and > 0 if there was no room in the left hand block.
  */
 static int push_node_left(struct btrfs_trans_handle *trans,
-			  struct btrfs_fs_info *fs_info,
 			  struct extent_buffer *dst,
 			  struct extent_buffer *src, int empty)
 {
+	struct btrfs_fs_info *fs_info = trans->fs_info;
 	int push_items = 0;
 	int src_nritems;
 	int dst_nritems;
@@ -3240,8 +3284,7 @@
 	} else
 		push_items = min(src_nritems - 8, push_items);
 
-	ret = tree_mod_log_eb_copy(fs_info, dst, src, dst_nritems, 0,
-				   push_items);
+	ret = tree_mod_log_eb_copy(dst, src, dst_nritems, 0, push_items);
 	if (ret) {
 		btrfs_abort_transaction(trans, ret);
 		return ret;
@@ -3279,10 +3322,10 @@
  * this will  only push up to 1/2 the contents of the left node over
  */
 static int balance_node_right(struct btrfs_trans_handle *trans,
-			      struct btrfs_fs_info *fs_info,
 			      struct extent_buffer *dst,
 			      struct extent_buffer *src)
 {
+	struct btrfs_fs_info *fs_info = trans->fs_info;
 	int push_items = 0;
 	int max_push;
 	int src_nritems;
@@ -3316,8 +3359,8 @@
 				      (dst_nritems) *
 				      sizeof(struct btrfs_key_ptr));
 
-	ret = tree_mod_log_eb_copy(fs_info, dst, src, 0,
-				   src_nritems - push_items, push_items);
+	ret = tree_mod_log_eb_copy(dst, src, 0, src_nritems - push_items,
+				   push_items);
 	if (ret) {
 		btrfs_abort_transaction(trans, ret);
 		return ret;
@@ -3364,8 +3407,8 @@
 	else
 		btrfs_node_key(lower, &lower_key, 0);
 
-	c = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid,
-				   &lower_key, level, root->node->start, 0);
+	c = alloc_tree_block_no_bg_flush(trans, root, 0, &lower_key, level,
+					 root->node->start, 0);
 	if (IS_ERR(c))
 		return PTR_ERR(c);
 
@@ -3405,7 +3448,7 @@
  * blocknr is the block the key points to.
  */
 static void insert_ptr(struct btrfs_trans_handle *trans,
-		       struct btrfs_fs_info *fs_info, struct btrfs_path *path,
+		       struct btrfs_path *path,
 		       struct btrfs_disk_key *key, u64 bytenr,
 		       int slot, int level)
 {
@@ -3418,7 +3461,7 @@
 	lower = path->nodes[level];
 	nritems = btrfs_header_nritems(lower);
 	BUG_ON(slot > nritems);
-	BUG_ON(nritems == BTRFS_NODEPTRS_PER_BLOCK(fs_info));
+	BUG_ON(nritems == BTRFS_NODEPTRS_PER_BLOCK(trans->fs_info));
 	if (slot != nritems) {
 		if (level) {
 			ret = tree_mod_log_insert_move(lower, slot + 1, slot,
@@ -3494,15 +3537,15 @@
 	mid = (c_nritems + 1) / 2;
 	btrfs_node_key(c, &disk_key, mid);
 
-	split = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid,
-			&disk_key, level, c->start, 0);
+	split = alloc_tree_block_no_bg_flush(trans, root, 0, &disk_key, level,
+					     c->start, 0);
 	if (IS_ERR(split))
 		return PTR_ERR(split);
 
 	root_add_used(root, fs_info->nodesize);
 	ASSERT(btrfs_header_level(c) == level);
 
-	ret = tree_mod_log_eb_copy(fs_info, split, c, 0, mid, c_nritems - mid);
+	ret = tree_mod_log_eb_copy(split, c, 0, mid, c_nritems - mid);
 	if (ret) {
 		btrfs_abort_transaction(trans, ret);
 		return ret;
@@ -3518,7 +3561,7 @@
 	btrfs_mark_buffer_dirty(c);
 	btrfs_mark_buffer_dirty(split);
 
-	insert_ptr(trans, fs_info, path, &disk_key, split->start,
+	insert_ptr(trans, path, &disk_key, split->start,
 		   path->slots[level + 1] + 1, level + 1);
 
 	if (path->slots[level] >= mid) {
@@ -3550,7 +3593,7 @@
 
 	if (!nr)
 		return 0;
-	btrfs_init_map_token(&token);
+	btrfs_init_map_token(&token, l);
 	start_item = btrfs_item_nr(start);
 	end_item = btrfs_item_nr(end);
 	data_len = btrfs_token_item_offset(l, start_item, &token) +
@@ -3566,9 +3609,9 @@
  * the start of the leaf data.  IOW, how much room
  * the leaf has left for both items and data
  */
-noinline int btrfs_leaf_free_space(struct btrfs_fs_info *fs_info,
-				   struct extent_buffer *leaf)
+noinline int btrfs_leaf_free_space(struct extent_buffer *leaf)
 {
+	struct btrfs_fs_info *fs_info = leaf->fs_info;
 	int nritems = btrfs_header_nritems(leaf);
 	int ret;
 
@@ -3587,13 +3630,13 @@
  * min slot controls the lowest index we're willing to push to the
  * right.  We'll push up to and including min_slot, but no lower
  */
-static noinline int __push_leaf_right(struct btrfs_fs_info *fs_info,
-				      struct btrfs_path *path,
+static noinline int __push_leaf_right(struct btrfs_path *path,
 				      int data_size, int empty,
 				      struct extent_buffer *right,
 				      int free_space, u32 left_nritems,
 				      u32 min_slot)
 {
+	struct btrfs_fs_info *fs_info = right->fs_info;
 	struct extent_buffer *left = path->nodes[0];
 	struct extent_buffer *upper = path->nodes[1];
 	struct btrfs_map_token token;
@@ -3608,8 +3651,6 @@
 	u32 data_end;
 	u32 this_item_size;
 
-	btrfs_init_map_token(&token);
-
 	if (empty)
 		nr = 0;
 	else
@@ -3627,7 +3668,8 @@
 			if (path->slots[0] > i)
 				break;
 			if (path->slots[0] == i) {
-				int space = btrfs_leaf_free_space(fs_info, left);
+				int space = btrfs_leaf_free_space(left);
+
 				if (space + push_space * 2 > free_space)
 					break;
 			}
@@ -3656,10 +3698,10 @@
 	right_nritems = btrfs_header_nritems(right);
 
 	push_space = btrfs_item_end_nr(left, left_nritems - push_items);
-	push_space -= leaf_data_end(fs_info, left);
+	push_space -= leaf_data_end(left);
 
 	/* make room in the right data area */
-	data_end = leaf_data_end(fs_info, right);
+	data_end = leaf_data_end(right);
 	memmove_extent_buffer(right,
 			      BTRFS_LEAF_DATA_OFFSET + data_end - push_space,
 			      BTRFS_LEAF_DATA_OFFSET + data_end,
@@ -3668,7 +3710,7 @@
 	/* copy from the left data area */
 	copy_extent_buffer(right, left, BTRFS_LEAF_DATA_OFFSET +
 		     BTRFS_LEAF_DATA_SIZE(fs_info) - push_space,
-		     BTRFS_LEAF_DATA_OFFSET + leaf_data_end(fs_info, left),
+		     BTRFS_LEAF_DATA_OFFSET + leaf_data_end(left),
 		     push_space);
 
 	memmove_extent_buffer(right, btrfs_item_nr_offset(push_items),
@@ -3681,6 +3723,7 @@
 		   push_items * sizeof(struct btrfs_item));
 
 	/* update the item pointers */
+	btrfs_init_map_token(&token, right);
 	right_nritems += push_items;
 	btrfs_set_header_nritems(right, right_nritems);
 	push_space = BTRFS_LEAF_DATA_SIZE(fs_info);
@@ -3696,7 +3739,7 @@
 	if (left_nritems)
 		btrfs_mark_buffer_dirty(left);
 	else
-		clean_tree_block(fs_info, left);
+		btrfs_clean_tree_block(left);
 
 	btrfs_mark_buffer_dirty(right);
 
@@ -3708,7 +3751,7 @@
 	if (path->slots[0] >= left_nritems) {
 		path->slots[0] -= left_nritems;
 		if (btrfs_header_nritems(path->nodes[0]) == 0)
-			clean_tree_block(fs_info, path->nodes[0]);
+			btrfs_clean_tree_block(path->nodes[0]);
 		btrfs_tree_unlock(path->nodes[0]);
 		free_extent_buffer(path->nodes[0]);
 		path->nodes[0] = right;
@@ -3740,7 +3783,6 @@
 			   int min_data_size, int data_size,
 			   int empty, u32 min_slot)
 {
-	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct extent_buffer *left = path->nodes[0];
 	struct extent_buffer *right;
 	struct extent_buffer *upper;
@@ -3759,7 +3801,7 @@
 
 	btrfs_assert_tree_locked(path->nodes[1]);
 
-	right = read_node_slot(fs_info, upper, slot + 1);
+	right = btrfs_read_node_slot(upper, slot + 1);
 	/*
 	 * slot + 1 is not valid or we fail to read the right node,
 	 * no big deal, just return.
@@ -3768,9 +3810,9 @@
 		return 1;
 
 	btrfs_tree_lock(right);
-	btrfs_set_lock_blocking(right);
+	btrfs_set_lock_blocking_write(right);
 
-	free_space = btrfs_leaf_free_space(fs_info, right);
+	free_space = btrfs_leaf_free_space(right);
 	if (free_space < data_size)
 		goto out_unlock;
 
@@ -3780,7 +3822,7 @@
 	if (ret)
 		goto out_unlock;
 
-	free_space = btrfs_leaf_free_space(fs_info, right);
+	free_space = btrfs_leaf_free_space(right);
 	if (free_space < data_size)
 		goto out_unlock;
 
@@ -3792,7 +3834,7 @@
 		/* Key greater than all keys in the leaf, right neighbor has
 		 * enough room for it and we're not emptying our leaf to delete
 		 * it, therefore use right neighbor to insert the new item and
-		 * no need to touch/dirty our left leaft. */
+		 * no need to touch/dirty our left leaf. */
 		btrfs_tree_unlock(left);
 		free_extent_buffer(left);
 		path->nodes[0] = right;
@@ -3801,7 +3843,7 @@
 		return 0;
 	}
 
-	return __push_leaf_right(fs_info, path, min_data_size, empty,
+	return __push_leaf_right(path, min_data_size, empty,
 				right, free_space, left_nritems, min_slot);
 out_unlock:
 	btrfs_tree_unlock(right);
@@ -3817,12 +3859,12 @@
  * item at 'max_slot' won't be touched.  Use (u32)-1 to make us do all the
  * items
  */
-static noinline int __push_leaf_left(struct btrfs_fs_info *fs_info,
-				     struct btrfs_path *path, int data_size,
+static noinline int __push_leaf_left(struct btrfs_path *path, int data_size,
 				     int empty, struct extent_buffer *left,
 				     int free_space, u32 right_nritems,
 				     u32 max_slot)
 {
+	struct btrfs_fs_info *fs_info = left->fs_info;
 	struct btrfs_disk_key disk_key;
 	struct extent_buffer *right = path->nodes[0];
 	int i;
@@ -3836,8 +3878,6 @@
 	u32 old_left_item_size;
 	struct btrfs_map_token token;
 
-	btrfs_init_map_token(&token);
-
 	if (empty)
 		nr = min(right_nritems, max_slot);
 	else
@@ -3850,7 +3890,8 @@
 			if (path->slots[0] < i)
 				break;
 			if (path->slots[0] == i) {
-				int space = btrfs_leaf_free_space(fs_info, right);
+				int space = btrfs_leaf_free_space(right);
+
 				if (space + push_space * 2 > free_space)
 					break;
 			}
@@ -3883,13 +3924,14 @@
 		     btrfs_item_offset_nr(right, push_items - 1);
 
 	copy_extent_buffer(left, right, BTRFS_LEAF_DATA_OFFSET +
-		     leaf_data_end(fs_info, left) - push_space,
+		     leaf_data_end(left) - push_space,
 		     BTRFS_LEAF_DATA_OFFSET +
 		     btrfs_item_offset_nr(right, push_items - 1),
 		     push_space);
 	old_left_nritems = btrfs_header_nritems(left);
 	BUG_ON(old_left_nritems <= 0);
 
+	btrfs_init_map_token(&token, left);
 	old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1);
 	for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
 		u32 ioff;
@@ -3910,17 +3952,19 @@
 
 	if (push_items < right_nritems) {
 		push_space = btrfs_item_offset_nr(right, push_items - 1) -
-						  leaf_data_end(fs_info, right);
+						  leaf_data_end(right);
 		memmove_extent_buffer(right, BTRFS_LEAF_DATA_OFFSET +
 				      BTRFS_LEAF_DATA_SIZE(fs_info) - push_space,
 				      BTRFS_LEAF_DATA_OFFSET +
-				      leaf_data_end(fs_info, right), push_space);
+				      leaf_data_end(right), push_space);
 
 		memmove_extent_buffer(right, btrfs_item_nr_offset(0),
 			      btrfs_item_nr_offset(push_items),
 			     (btrfs_header_nritems(right) - push_items) *
 			     sizeof(struct btrfs_item));
 	}
+
+	btrfs_init_map_token(&token, right);
 	right_nritems -= push_items;
 	btrfs_set_header_nritems(right, right_nritems);
 	push_space = BTRFS_LEAF_DATA_SIZE(fs_info);
@@ -3936,7 +3980,7 @@
 	if (right_nritems)
 		btrfs_mark_buffer_dirty(right);
 	else
-		clean_tree_block(fs_info, right);
+		btrfs_clean_tree_block(right);
 
 	btrfs_item_key(right, &disk_key, 0);
 	fixup_low_keys(path, &disk_key, 1);
@@ -3973,7 +4017,6 @@
 			  *root, struct btrfs_path *path, int min_data_size,
 			  int data_size, int empty, u32 max_slot)
 {
-	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct extent_buffer *right = path->nodes[0];
 	struct extent_buffer *left;
 	int slot;
@@ -3993,7 +4036,7 @@
 
 	btrfs_assert_tree_locked(path->nodes[1]);
 
-	left = read_node_slot(fs_info, path->nodes[1], slot - 1);
+	left = btrfs_read_node_slot(path->nodes[1], slot - 1);
 	/*
 	 * slot - 1 is not valid or we fail to read the left node,
 	 * no big deal, just return.
@@ -4002,9 +4045,9 @@
 		return 1;
 
 	btrfs_tree_lock(left);
-	btrfs_set_lock_blocking(left);
+	btrfs_set_lock_blocking_write(left);
 
-	free_space = btrfs_leaf_free_space(fs_info, left);
+	free_space = btrfs_leaf_free_space(left);
 	if (free_space < data_size) {
 		ret = 1;
 		goto out;
@@ -4020,13 +4063,13 @@
 		goto out;
 	}
 
-	free_space = btrfs_leaf_free_space(fs_info, left);
+	free_space = btrfs_leaf_free_space(left);
 	if (free_space < data_size) {
 		ret = 1;
 		goto out;
 	}
 
-	return __push_leaf_left(fs_info, path, min_data_size,
+	return __push_leaf_left(path, min_data_size,
 			       empty, left, free_space, right_nritems,
 			       max_slot);
 out:
@@ -4040,23 +4083,21 @@
  * available for the resulting leaf level of the path.
  */
 static noinline void copy_for_split(struct btrfs_trans_handle *trans,
-				    struct btrfs_fs_info *fs_info,
 				    struct btrfs_path *path,
 				    struct extent_buffer *l,
 				    struct extent_buffer *right,
 				    int slot, int mid, int nritems)
 {
+	struct btrfs_fs_info *fs_info = trans->fs_info;
 	int data_copy_size;
 	int rt_data_off;
 	int i;
 	struct btrfs_disk_key disk_key;
 	struct btrfs_map_token token;
 
-	btrfs_init_map_token(&token);
-
 	nritems = nritems - mid;
 	btrfs_set_header_nritems(right, nritems);
-	data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(fs_info, l);
+	data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(l);
 
 	copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
 			   btrfs_item_nr_offset(mid),
@@ -4065,10 +4106,11 @@
 	copy_extent_buffer(right, l,
 		     BTRFS_LEAF_DATA_OFFSET + BTRFS_LEAF_DATA_SIZE(fs_info) -
 		     data_copy_size, BTRFS_LEAF_DATA_OFFSET +
-		     leaf_data_end(fs_info, l), data_copy_size);
+		     leaf_data_end(l), data_copy_size);
 
 	rt_data_off = BTRFS_LEAF_DATA_SIZE(fs_info) - btrfs_item_end_nr(l, mid);
 
+	btrfs_init_map_token(&token, right);
 	for (i = 0; i < nritems; i++) {
 		struct btrfs_item *item = btrfs_item_nr(i);
 		u32 ioff;
@@ -4080,8 +4122,7 @@
 
 	btrfs_set_header_nritems(l, mid);
 	btrfs_item_key(right, &disk_key, 0);
-	insert_ptr(trans, fs_info, path, &disk_key, right->start,
-		   path->slots[1] + 1, 1);
+	insert_ptr(trans, path, &disk_key, right->start, path->slots[1] + 1, 1);
 
 	btrfs_mark_buffer_dirty(right);
 	btrfs_mark_buffer_dirty(l);
@@ -4116,7 +4157,6 @@
 					  struct btrfs_path *path,
 					  int data_size)
 {
-	struct btrfs_fs_info *fs_info = root->fs_info;
 	int ret;
 	int progress = 0;
 	int slot;
@@ -4125,7 +4165,7 @@
 
 	slot = path->slots[0];
 	if (slot < btrfs_header_nritems(path->nodes[0]))
-		space_needed -= btrfs_leaf_free_space(fs_info, path->nodes[0]);
+		space_needed -= btrfs_leaf_free_space(path->nodes[0]);
 
 	/*
 	 * try to push all the items after our slot into the
@@ -4146,14 +4186,14 @@
 	if (path->slots[0] == 0 || path->slots[0] == nritems)
 		return 0;
 
-	if (btrfs_leaf_free_space(fs_info, path->nodes[0]) >= data_size)
+	if (btrfs_leaf_free_space(path->nodes[0]) >= data_size)
 		return 0;
 
 	/* try to push all the items before our slot into the next leaf */
 	slot = path->slots[0];
 	space_needed = data_size;
 	if (slot > 0)
-		space_needed -= btrfs_leaf_free_space(fs_info, path->nodes[0]);
+		space_needed -= btrfs_leaf_free_space(path->nodes[0]);
 	ret = push_leaf_left(trans, root, path, 1, space_needed, 0, slot);
 	if (ret < 0)
 		return ret;
@@ -4202,7 +4242,7 @@
 		int space_needed = data_size;
 
 		if (slot < btrfs_header_nritems(l))
-			space_needed -= btrfs_leaf_free_space(fs_info, l);
+			space_needed -= btrfs_leaf_free_space(l);
 
 		wret = push_leaf_right(trans, root, path, space_needed,
 				       space_needed, 0, 0);
@@ -4211,8 +4251,7 @@
 		if (wret) {
 			space_needed = data_size;
 			if (slot > 0)
-				space_needed -= btrfs_leaf_free_space(fs_info,
-								      l);
+				space_needed -= btrfs_leaf_free_space(l);
 			wret = push_leaf_left(trans, root, path, space_needed,
 					      space_needed, 0, (u32)-1);
 			if (wret < 0)
@@ -4221,7 +4260,7 @@
 		l = path->nodes[0];
 
 		/* did the pushes work? */
-		if (btrfs_leaf_free_space(fs_info, l) >= data_size)
+		if (btrfs_leaf_free_space(l) >= data_size)
 			return 0;
 	}
 
@@ -4279,8 +4318,8 @@
 	else
 		btrfs_item_key(l, &disk_key, mid);
 
-	right = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid,
-			&disk_key, 0, l->start, 0);
+	right = alloc_tree_block_no_bg_flush(trans, root, 0, &disk_key, 0,
+					     l->start, 0);
 	if (IS_ERR(right))
 		return PTR_ERR(right);
 
@@ -4289,7 +4328,7 @@
 	if (split == 0) {
 		if (mid <= slot) {
 			btrfs_set_header_nritems(right, 0);
-			insert_ptr(trans, fs_info, path, &disk_key,
+			insert_ptr(trans, path, &disk_key,
 				   right->start, path->slots[1] + 1, 1);
 			btrfs_tree_unlock(path->nodes[0]);
 			free_extent_buffer(path->nodes[0]);
@@ -4298,7 +4337,7 @@
 			path->slots[1] += 1;
 		} else {
 			btrfs_set_header_nritems(right, 0);
-			insert_ptr(trans, fs_info, path, &disk_key,
+			insert_ptr(trans, path, &disk_key,
 				   right->start, path->slots[1], 1);
 			btrfs_tree_unlock(path->nodes[0]);
 			free_extent_buffer(path->nodes[0]);
@@ -4315,7 +4354,7 @@
 		return ret;
 	}
 
-	copy_for_split(trans, fs_info, path, l, right, slot, mid, nritems);
+	copy_for_split(trans, path, l, right, slot, mid, nritems);
 
 	if (split == 2) {
 		BUG_ON(num_doubles != 0);
@@ -4328,7 +4367,7 @@
 push_for_double:
 	push_for_double_split(trans, root, path, data_size);
 	tried_avoid_double = 1;
-	if (btrfs_leaf_free_space(fs_info, path->nodes[0]) >= data_size)
+	if (btrfs_leaf_free_space(path->nodes[0]) >= data_size)
 		return 0;
 	goto again;
 }
@@ -4337,7 +4376,6 @@
 					 struct btrfs_root *root,
 					 struct btrfs_path *path, int ins_len)
 {
-	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_key key;
 	struct extent_buffer *leaf;
 	struct btrfs_file_extent_item *fi;
@@ -4351,7 +4389,7 @@
 	BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY &&
 	       key.type != BTRFS_EXTENT_CSUM_KEY);
 
-	if (btrfs_leaf_free_space(fs_info, leaf) >= ins_len)
+	if (btrfs_leaf_free_space(leaf) >= ins_len)
 		return 0;
 
 	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
@@ -4378,7 +4416,7 @@
 		goto err;
 
 	/* the leaf has  changed, it now has room.  return now */
-	if (btrfs_leaf_free_space(fs_info, path->nodes[0]) >= ins_len)
+	if (btrfs_leaf_free_space(path->nodes[0]) >= ins_len)
 		goto err;
 
 	if (key.type == BTRFS_EXTENT_DATA_KEY) {
@@ -4401,8 +4439,7 @@
 	return ret;
 }
 
-static noinline int split_item(struct btrfs_fs_info *fs_info,
-			       struct btrfs_path *path,
+static noinline int split_item(struct btrfs_path *path,
 			       const struct btrfs_key *new_key,
 			       unsigned long split_offset)
 {
@@ -4417,7 +4454,7 @@
 	struct btrfs_disk_key disk_key;
 
 	leaf = path->nodes[0];
-	BUG_ON(btrfs_leaf_free_space(fs_info, leaf) < sizeof(struct btrfs_item));
+	BUG_ON(btrfs_leaf_free_space(leaf) < sizeof(struct btrfs_item));
 
 	btrfs_set_path_blocking(path);
 
@@ -4466,7 +4503,7 @@
 			    item_size - split_offset);
 	btrfs_mark_buffer_dirty(leaf);
 
-	BUG_ON(btrfs_leaf_free_space(fs_info, leaf) < 0);
+	BUG_ON(btrfs_leaf_free_space(leaf) < 0);
 	kfree(buf);
 	return 0;
 }
@@ -4498,7 +4535,7 @@
 	if (ret)
 		return ret;
 
-	ret = split_item(root->fs_info, path, new_key, split_offset);
+	ret = split_item(path, new_key, split_offset);
 	return ret;
 }
 
@@ -4544,8 +4581,7 @@
  * off the end of the item or if we shift the item to chop bytes off
  * the front.
  */
-void btrfs_truncate_item(struct btrfs_fs_info *fs_info,
-			 struct btrfs_path *path, u32 new_size, int from_end)
+void btrfs_truncate_item(struct btrfs_path *path, u32 new_size, int from_end)
 {
 	int slot;
 	struct extent_buffer *leaf;
@@ -4558,8 +4594,6 @@
 	int i;
 	struct btrfs_map_token token;
 
-	btrfs_init_map_token(&token);
-
 	leaf = path->nodes[0];
 	slot = path->slots[0];
 
@@ -4568,7 +4602,7 @@
 		return;
 
 	nritems = btrfs_header_nritems(leaf);
-	data_end = leaf_data_end(fs_info, leaf);
+	data_end = leaf_data_end(leaf);
 
 	old_data_start = btrfs_item_offset_nr(leaf, slot);
 
@@ -4581,6 +4615,7 @@
 	 * item0..itemN ... dataN.offset..dataN.size .. data0.size
 	 */
 	/* first correct the data pointers */
+	btrfs_init_map_token(&token, leaf);
 	for (i = slot; i < nritems; i++) {
 		u32 ioff;
 		item = btrfs_item_nr(i);
@@ -4634,7 +4669,7 @@
 	btrfs_set_item_size(leaf, item, new_size);
 	btrfs_mark_buffer_dirty(leaf);
 
-	if (btrfs_leaf_free_space(fs_info, leaf) < 0) {
+	if (btrfs_leaf_free_space(leaf) < 0) {
 		btrfs_print_leaf(leaf);
 		BUG();
 	}
@@ -4643,8 +4678,7 @@
 /*
  * make the item pointed to by the path bigger, data_size is the added size.
  */
-void btrfs_extend_item(struct btrfs_fs_info *fs_info, struct btrfs_path *path,
-		       u32 data_size)
+void btrfs_extend_item(struct btrfs_path *path, u32 data_size)
 {
 	int slot;
 	struct extent_buffer *leaf;
@@ -4656,14 +4690,12 @@
 	int i;
 	struct btrfs_map_token token;
 
-	btrfs_init_map_token(&token);
-
 	leaf = path->nodes[0];
 
 	nritems = btrfs_header_nritems(leaf);
-	data_end = leaf_data_end(fs_info, leaf);
+	data_end = leaf_data_end(leaf);
 
-	if (btrfs_leaf_free_space(fs_info, leaf) < data_size) {
+	if (btrfs_leaf_free_space(leaf) < data_size) {
 		btrfs_print_leaf(leaf);
 		BUG();
 	}
@@ -4673,15 +4705,16 @@
 	BUG_ON(slot < 0);
 	if (slot >= nritems) {
 		btrfs_print_leaf(leaf);
-		btrfs_crit(fs_info, "slot %d too large, nritems %d",
+		btrfs_crit(leaf->fs_info, "slot %d too large, nritems %d",
 			   slot, nritems);
-		BUG_ON(1);
+		BUG();
 	}
 
 	/*
 	 * item0..itemN ... dataN.offset..dataN.size .. data0.size
 	 */
 	/* first correct the data pointers */
+	btrfs_init_map_token(&token, leaf);
 	for (i = slot; i < nritems; i++) {
 		u32 ioff;
 		item = btrfs_item_nr(i);
@@ -4702,7 +4735,7 @@
 	btrfs_set_item_size(leaf, item, old_size + data_size);
 	btrfs_mark_buffer_dirty(leaf);
 
-	if (btrfs_leaf_free_space(fs_info, leaf) < 0) {
+	if (btrfs_leaf_free_space(leaf) < 0) {
 		btrfs_print_leaf(leaf);
 		BUG();
 	}
@@ -4733,21 +4766,20 @@
 	}
 	btrfs_unlock_up_safe(path, 1);
 
-	btrfs_init_map_token(&token);
-
 	leaf = path->nodes[0];
 	slot = path->slots[0];
 
 	nritems = btrfs_header_nritems(leaf);
-	data_end = leaf_data_end(fs_info, leaf);
+	data_end = leaf_data_end(leaf);
 
-	if (btrfs_leaf_free_space(fs_info, leaf) < total_size) {
+	if (btrfs_leaf_free_space(leaf) < total_size) {
 		btrfs_print_leaf(leaf);
 		btrfs_crit(fs_info, "not enough freespace need %u have %d",
-			   total_size, btrfs_leaf_free_space(fs_info, leaf));
+			   total_size, btrfs_leaf_free_space(leaf));
 		BUG();
 	}
 
+	btrfs_init_map_token(&token, leaf);
 	if (slot != nritems) {
 		unsigned int old_data = btrfs_item_end_nr(leaf, slot);
 
@@ -4755,7 +4787,7 @@
 			btrfs_print_leaf(leaf);
 			btrfs_crit(fs_info, "slot %d old_data %d data_end %d",
 				   slot, old_data, data_end);
-			BUG_ON(1);
+			BUG();
 		}
 		/*
 		 * item0..itemN ... dataN.offset..dataN.size .. data0.size
@@ -4795,7 +4827,7 @@
 	btrfs_set_header_nritems(leaf, nritems + nr);
 	btrfs_mark_buffer_dirty(leaf);
 
-	if (btrfs_leaf_free_space(fs_info, leaf) < 0) {
+	if (btrfs_leaf_free_space(leaf) < 0) {
 		btrfs_print_leaf(leaf);
 		BUG();
 	}
@@ -4954,9 +4986,6 @@
 	int wret;
 	int i;
 	u32 nritems;
-	struct btrfs_map_token token;
-
-	btrfs_init_map_token(&token);
 
 	leaf = path->nodes[0];
 	last_off = btrfs_item_offset_nr(leaf, slot + nr - 1);
@@ -4967,13 +4996,15 @@
 	nritems = btrfs_header_nritems(leaf);
 
 	if (slot + nr != nritems) {
-		int data_end = leaf_data_end(fs_info, leaf);
+		int data_end = leaf_data_end(leaf);
+		struct btrfs_map_token token;
 
 		memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET +
 			      data_end + dsize,
 			      BTRFS_LEAF_DATA_OFFSET + data_end,
 			      last_off - data_end);
 
+		btrfs_init_map_token(&token, leaf);
 		for (i = slot + nr; i < nritems; i++) {
 			u32 ioff;
 
@@ -4997,7 +5028,7 @@
 			btrfs_set_header_level(leaf, 0);
 		} else {
 			btrfs_set_path_blocking(path);
-			clean_tree_block(fs_info, leaf);
+			btrfs_clean_tree_block(leaf);
 			btrfs_del_leaf(trans, root, path, leaf);
 		}
 	} else {
@@ -5127,7 +5158,6 @@
 			 struct btrfs_path *path,
 			 u64 min_trans)
 {
-	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct extent_buffer *cur;
 	struct btrfs_key found_key;
 	int slot;
@@ -5153,6 +5183,10 @@
 		nritems = btrfs_header_nritems(cur);
 		level = btrfs_header_level(cur);
 		sret = btrfs_bin_search(cur, min_key, level, &slot);
+		if (sret < 0) {
+			ret = sret;
+			goto out;
+		}
 
 		/* at the lowest level, we're done, setup the path and exit */
 		if (level == path->lowest_level) {
@@ -5204,7 +5238,7 @@
 			goto out;
 		}
 		btrfs_set_path_blocking(path);
-		cur = read_node_slot(fs_info, cur, slot);
+		cur = btrfs_read_node_slot(cur, slot);
 		if (IS_ERR(cur)) {
 			ret = PTR_ERR(cur);
 			goto out;
@@ -5215,7 +5249,6 @@
 		path->locks[level - 1] = BTRFS_READ_LOCK;
 		path->nodes[level - 1] = cur;
 		unlock_up(path, level, 1, 0, NULL);
-		btrfs_clear_path_blocking(path, NULL, 0);
 	}
 out:
 	path->keep_locks = keep_locks;
@@ -5227,373 +5260,6 @@
 	return ret;
 }
 
-static int tree_move_down(struct btrfs_fs_info *fs_info,
-			   struct btrfs_path *path,
-			   int *level)
-{
-	struct extent_buffer *eb;
-
-	BUG_ON(*level == 0);
-	eb = read_node_slot(fs_info, path->nodes[*level], path->slots[*level]);
-	if (IS_ERR(eb))
-		return PTR_ERR(eb);
-
-	path->nodes[*level - 1] = eb;
-	path->slots[*level - 1] = 0;
-	(*level)--;
-	return 0;
-}
-
-static int tree_move_next_or_upnext(struct btrfs_path *path,
-				    int *level, int root_level)
-{
-	int ret = 0;
-	int nritems;
-	nritems = btrfs_header_nritems(path->nodes[*level]);
-
-	path->slots[*level]++;
-
-	while (path->slots[*level] >= nritems) {
-		if (*level == root_level)
-			return -1;
-
-		/* move upnext */
-		path->slots[*level] = 0;
-		free_extent_buffer(path->nodes[*level]);
-		path->nodes[*level] = NULL;
-		(*level)++;
-		path->slots[*level]++;
-
-		nritems = btrfs_header_nritems(path->nodes[*level]);
-		ret = 1;
-	}
-	return ret;
-}
-
-/*
- * Returns 1 if it had to move up and next. 0 is returned if it moved only next
- * or down.
- */
-static int tree_advance(struct btrfs_fs_info *fs_info,
-			struct btrfs_path *path,
-			int *level, int root_level,
-			int allow_down,
-			struct btrfs_key *key)
-{
-	int ret;
-
-	if (*level == 0 || !allow_down) {
-		ret = tree_move_next_or_upnext(path, level, root_level);
-	} else {
-		ret = tree_move_down(fs_info, path, level);
-	}
-	if (ret >= 0) {
-		if (*level == 0)
-			btrfs_item_key_to_cpu(path->nodes[*level], key,
-					path->slots[*level]);
-		else
-			btrfs_node_key_to_cpu(path->nodes[*level], key,
-					path->slots[*level]);
-	}
-	return ret;
-}
-
-static int tree_compare_item(struct btrfs_path *left_path,
-			     struct btrfs_path *right_path,
-			     char *tmp_buf)
-{
-	int cmp;
-	int len1, len2;
-	unsigned long off1, off2;
-
-	len1 = btrfs_item_size_nr(left_path->nodes[0], left_path->slots[0]);
-	len2 = btrfs_item_size_nr(right_path->nodes[0], right_path->slots[0]);
-	if (len1 != len2)
-		return 1;
-
-	off1 = btrfs_item_ptr_offset(left_path->nodes[0], left_path->slots[0]);
-	off2 = btrfs_item_ptr_offset(right_path->nodes[0],
-				right_path->slots[0]);
-
-	read_extent_buffer(left_path->nodes[0], tmp_buf, off1, len1);
-
-	cmp = memcmp_extent_buffer(right_path->nodes[0], tmp_buf, off2, len1);
-	if (cmp)
-		return 1;
-	return 0;
-}
-
-#define ADVANCE 1
-#define ADVANCE_ONLY_NEXT -1
-
-/*
- * This function compares two trees and calls the provided callback for
- * every changed/new/deleted item it finds.
- * If shared tree blocks are encountered, whole subtrees are skipped, making
- * the compare pretty fast on snapshotted subvolumes.
- *
- * This currently works on commit roots only. As commit roots are read only,
- * we don't do any locking. The commit roots are protected with transactions.
- * Transactions are ended and rejoined when a commit is tried in between.
- *
- * This function checks for modifications done to the trees while comparing.
- * If it detects a change, it aborts immediately.
- */
-int btrfs_compare_trees(struct btrfs_root *left_root,
-			struct btrfs_root *right_root,
-			btrfs_changed_cb_t changed_cb, void *ctx)
-{
-	struct btrfs_fs_info *fs_info = left_root->fs_info;
-	int ret;
-	int cmp;
-	struct btrfs_path *left_path = NULL;
-	struct btrfs_path *right_path = NULL;
-	struct btrfs_key left_key;
-	struct btrfs_key right_key;
-	char *tmp_buf = NULL;
-	int left_root_level;
-	int right_root_level;
-	int left_level;
-	int right_level;
-	int left_end_reached;
-	int right_end_reached;
-	int advance_left;
-	int advance_right;
-	u64 left_blockptr;
-	u64 right_blockptr;
-	u64 left_gen;
-	u64 right_gen;
-
-	left_path = btrfs_alloc_path();
-	if (!left_path) {
-		ret = -ENOMEM;
-		goto out;
-	}
-	right_path = btrfs_alloc_path();
-	if (!right_path) {
-		ret = -ENOMEM;
-		goto out;
-	}
-
-	tmp_buf = kvmalloc(fs_info->nodesize, GFP_KERNEL);
-	if (!tmp_buf) {
-		ret = -ENOMEM;
-		goto out;
-	}
-
-	left_path->search_commit_root = 1;
-	left_path->skip_locking = 1;
-	right_path->search_commit_root = 1;
-	right_path->skip_locking = 1;
-
-	/*
-	 * Strategy: Go to the first items of both trees. Then do
-	 *
-	 * If both trees are at level 0
-	 *   Compare keys of current items
-	 *     If left < right treat left item as new, advance left tree
-	 *       and repeat
-	 *     If left > right treat right item as deleted, advance right tree
-	 *       and repeat
-	 *     If left == right do deep compare of items, treat as changed if
-	 *       needed, advance both trees and repeat
-	 * If both trees are at the same level but not at level 0
-	 *   Compare keys of current nodes/leafs
-	 *     If left < right advance left tree and repeat
-	 *     If left > right advance right tree and repeat
-	 *     If left == right compare blockptrs of the next nodes/leafs
-	 *       If they match advance both trees but stay at the same level
-	 *         and repeat
-	 *       If they don't match advance both trees while allowing to go
-	 *         deeper and repeat
-	 * If tree levels are different
-	 *   Advance the tree that needs it and repeat
-	 *
-	 * Advancing a tree means:
-	 *   If we are at level 0, try to go to the next slot. If that's not
-	 *   possible, go one level up and repeat. Stop when we found a level
-	 *   where we could go to the next slot. We may at this point be on a
-	 *   node or a leaf.
-	 *
-	 *   If we are not at level 0 and not on shared tree blocks, go one
-	 *   level deeper.
-	 *
-	 *   If we are not at level 0 and on shared tree blocks, go one slot to
-	 *   the right if possible or go up and right.
-	 */
-
-	down_read(&fs_info->commit_root_sem);
-	left_level = btrfs_header_level(left_root->commit_root);
-	left_root_level = left_level;
-	left_path->nodes[left_level] =
-			btrfs_clone_extent_buffer(left_root->commit_root);
-	if (!left_path->nodes[left_level]) {
-		up_read(&fs_info->commit_root_sem);
-		ret = -ENOMEM;
-		goto out;
-	}
-	extent_buffer_get(left_path->nodes[left_level]);
-
-	right_level = btrfs_header_level(right_root->commit_root);
-	right_root_level = right_level;
-	right_path->nodes[right_level] =
-			btrfs_clone_extent_buffer(right_root->commit_root);
-	if (!right_path->nodes[right_level]) {
-		up_read(&fs_info->commit_root_sem);
-		ret = -ENOMEM;
-		goto out;
-	}
-	extent_buffer_get(right_path->nodes[right_level]);
-	up_read(&fs_info->commit_root_sem);
-
-	if (left_level == 0)
-		btrfs_item_key_to_cpu(left_path->nodes[left_level],
-				&left_key, left_path->slots[left_level]);
-	else
-		btrfs_node_key_to_cpu(left_path->nodes[left_level],
-				&left_key, left_path->slots[left_level]);
-	if (right_level == 0)
-		btrfs_item_key_to_cpu(right_path->nodes[right_level],
-				&right_key, right_path->slots[right_level]);
-	else
-		btrfs_node_key_to_cpu(right_path->nodes[right_level],
-				&right_key, right_path->slots[right_level]);
-
-	left_end_reached = right_end_reached = 0;
-	advance_left = advance_right = 0;
-
-	while (1) {
-		if (advance_left && !left_end_reached) {
-			ret = tree_advance(fs_info, left_path, &left_level,
-					left_root_level,
-					advance_left != ADVANCE_ONLY_NEXT,
-					&left_key);
-			if (ret == -1)
-				left_end_reached = ADVANCE;
-			else if (ret < 0)
-				goto out;
-			advance_left = 0;
-		}
-		if (advance_right && !right_end_reached) {
-			ret = tree_advance(fs_info, right_path, &right_level,
-					right_root_level,
-					advance_right != ADVANCE_ONLY_NEXT,
-					&right_key);
-			if (ret == -1)
-				right_end_reached = ADVANCE;
-			else if (ret < 0)
-				goto out;
-			advance_right = 0;
-		}
-
-		if (left_end_reached && right_end_reached) {
-			ret = 0;
-			goto out;
-		} else if (left_end_reached) {
-			if (right_level == 0) {
-				ret = changed_cb(left_path, right_path,
-						&right_key,
-						BTRFS_COMPARE_TREE_DELETED,
-						ctx);
-				if (ret < 0)
-					goto out;
-			}
-			advance_right = ADVANCE;
-			continue;
-		} else if (right_end_reached) {
-			if (left_level == 0) {
-				ret = changed_cb(left_path, right_path,
-						&left_key,
-						BTRFS_COMPARE_TREE_NEW,
-						ctx);
-				if (ret < 0)
-					goto out;
-			}
-			advance_left = ADVANCE;
-			continue;
-		}
-
-		if (left_level == 0 && right_level == 0) {
-			cmp = btrfs_comp_cpu_keys(&left_key, &right_key);
-			if (cmp < 0) {
-				ret = changed_cb(left_path, right_path,
-						&left_key,
-						BTRFS_COMPARE_TREE_NEW,
-						ctx);
-				if (ret < 0)
-					goto out;
-				advance_left = ADVANCE;
-			} else if (cmp > 0) {
-				ret = changed_cb(left_path, right_path,
-						&right_key,
-						BTRFS_COMPARE_TREE_DELETED,
-						ctx);
-				if (ret < 0)
-					goto out;
-				advance_right = ADVANCE;
-			} else {
-				enum btrfs_compare_tree_result result;
-
-				WARN_ON(!extent_buffer_uptodate(left_path->nodes[0]));
-				ret = tree_compare_item(left_path, right_path,
-							tmp_buf);
-				if (ret)
-					result = BTRFS_COMPARE_TREE_CHANGED;
-				else
-					result = BTRFS_COMPARE_TREE_SAME;
-				ret = changed_cb(left_path, right_path,
-						 &left_key, result, ctx);
-				if (ret < 0)
-					goto out;
-				advance_left = ADVANCE;
-				advance_right = ADVANCE;
-			}
-		} else if (left_level == right_level) {
-			cmp = btrfs_comp_cpu_keys(&left_key, &right_key);
-			if (cmp < 0) {
-				advance_left = ADVANCE;
-			} else if (cmp > 0) {
-				advance_right = ADVANCE;
-			} else {
-				left_blockptr = btrfs_node_blockptr(
-						left_path->nodes[left_level],
-						left_path->slots[left_level]);
-				right_blockptr = btrfs_node_blockptr(
-						right_path->nodes[right_level],
-						right_path->slots[right_level]);
-				left_gen = btrfs_node_ptr_generation(
-						left_path->nodes[left_level],
-						left_path->slots[left_level]);
-				right_gen = btrfs_node_ptr_generation(
-						right_path->nodes[right_level],
-						right_path->slots[right_level]);
-				if (left_blockptr == right_blockptr &&
-				    left_gen == right_gen) {
-					/*
-					 * As we're on a shared block, don't
-					 * allow to go deeper.
-					 */
-					advance_left = ADVANCE_ONLY_NEXT;
-					advance_right = ADVANCE_ONLY_NEXT;
-				} else {
-					advance_left = ADVANCE;
-					advance_right = ADVANCE;
-				}
-			}
-		} else if (left_level < right_level) {
-			advance_right = ADVANCE;
-		} else {
-			advance_left = ADVANCE;
-		}
-	}
-
-out:
-	btrfs_free_path(left_path);
-	btrfs_free_path(right_path);
-	kvfree(tmp_buf);
-	return ret;
-}
-
 /*
  * this is similar to btrfs_next_leaf, but does not try to preserve
  * and fixup the path.  It looks for and returns the next key in the
@@ -5611,7 +5277,7 @@
 	int slot;
 	struct extent_buffer *c;
 
-	WARN_ON(!path->keep_locks);
+	WARN_ON(!path->keep_locks && !path->skip_locking);
 	while (level < BTRFS_MAX_LEVEL) {
 		if (!path->nodes[level])
 			return 1;
@@ -5627,7 +5293,7 @@
 			    !path->nodes[level + 1])
 				return 1;
 
-			if (path->locks[level + 1]) {
+			if (path->locks[level + 1] || path->skip_locking) {
 				level++;
 				continue;
 			}
@@ -5800,8 +5466,6 @@
 			if (!ret) {
 				btrfs_set_path_blocking(path);
 				btrfs_tree_read_lock(next);
-				btrfs_clear_path_blocking(path, next,
-							  BTRFS_READ_LOCK);
 			}
 			next_rw_lock = BTRFS_READ_LOCK;
 		}
@@ -5837,8 +5501,6 @@
 			if (!ret) {
 				btrfs_set_path_blocking(path);
 				btrfs_tree_read_lock(next);
-				btrfs_clear_path_blocking(path, next,
-							  BTRFS_READ_LOCK);
 			}
 			next_rw_lock = BTRFS_READ_LOCK;
 		}
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 2cddfe7..fe2b876 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -16,9 +16,9 @@
 #include <linux/backing-dev.h>
 #include <linux/wait.h>
 #include <linux/slab.h>
-#include <linux/kobject.h>
 #include <trace/events/btrfs.h>
 #include <asm/kmap_types.h>
+#include <asm/unaligned.h>
 #include <linux/pagemap.h>
 #include <linux/btrfs.h>
 #include <linux/btrfs_tree.h>
@@ -31,25 +31,34 @@
 #include "extent_io.h"
 #include "extent_map.h"
 #include "async-thread.h"
+#include "block-rsv.h"
 
 struct btrfs_trans_handle;
 struct btrfs_transaction;
 struct btrfs_pending_snapshot;
+struct btrfs_delayed_ref_root;
+struct btrfs_space_info;
+struct btrfs_block_group_cache;
 extern struct kmem_cache *btrfs_trans_handle_cachep;
 extern struct kmem_cache *btrfs_bit_radix_cachep;
 extern struct kmem_cache *btrfs_path_cachep;
 extern struct kmem_cache *btrfs_free_space_cachep;
+extern struct kmem_cache *btrfs_free_space_bitmap_cachep;
 struct btrfs_ordered_sum;
-
-#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
-#define STATIC noinline
-#else
-#define STATIC static noinline
-#endif
+struct btrfs_ref;
 
 #define BTRFS_MAGIC 0x4D5F53665248425FULL /* ascii _BHRfS_M, no null */
 
-#define BTRFS_MAX_MIRRORS 3
+/*
+ * Maximum number of mirrors that can be available for all profiles counting
+ * the target device of dev-replace as one. During an active device replace
+ * procedure, the target device of the copy operation is a mirror for the
+ * filesystem data as well that can be used to read data in order to repair
+ * read errors on other disks.
+ *
+ * Current value is derived from RAID1 with 2 copies.
+ */
+#define BTRFS_MAX_MIRRORS (2 + 1)
 
 #define BTRFS_MAX_LEVEL 8
 
@@ -74,9 +83,6 @@
  */
 #define BTRFS_LINK_MAX 65535U
 
-/* four bytes for CRC32 */
-static const int btrfs_csum_sizes[] = { 4 };
-
 #define BTRFS_EMPTY_DIR_SIZE 0
 
 /* ioprio of readahead is set to idle */
@@ -103,10 +109,6 @@
 	return div_u64(size + BTRFS_MAX_EXTENT_SIZE - 1, BTRFS_MAX_EXTENT_SIZE);
 }
 
-struct btrfs_mapping_tree {
-	struct extent_map_tree map_tree;
-};
-
 static inline unsigned long btrfs_chunk_item_size(int num_stripes)
 {
 	BUG_ON(num_stripes == 0);
@@ -115,13 +117,26 @@
 }
 
 /*
- * File system states
+ * Runtime (in-memory) states of filesystem
  */
-#define BTRFS_FS_STATE_ERROR		0
-#define BTRFS_FS_STATE_REMOUNTING	1
-#define BTRFS_FS_STATE_TRANS_ABORTED	2
-#define BTRFS_FS_STATE_DEV_REPLACING	3
-#define BTRFS_FS_STATE_DUMMY_FS_INFO	4
+enum {
+	/* Global indicator of serious filesystem errors */
+	BTRFS_FS_STATE_ERROR,
+	/*
+	 * Filesystem is being remounted, allow to skip some operations, like
+	 * defrag
+	 */
+	BTRFS_FS_STATE_REMOUNTING,
+	/* Track if a transaction abort has been reported on this filesystem */
+	BTRFS_FS_STATE_TRANS_ABORTED,
+	/*
+	 * Bio operations should be blocked on this filesystem because a source
+	 * or target device is being destroyed as part of a device replace
+	 */
+	BTRFS_FS_STATE_DEV_REPLACING,
+	/* The btrfs_fs_info created for self-tests */
+	BTRFS_FS_STATE_DUMMY_FS_INFO,
+};
 
 #define BTRFS_BACKREF_REV_MAX		256
 #define BTRFS_BACKREF_REV_SHIFT		56
@@ -201,9 +216,10 @@
  * it currently lacks any block count etc etc
  */
 struct btrfs_super_block {
-	u8 csum[BTRFS_CSUM_SIZE];
 	/* the first 4 fields must match struct btrfs_header */
-	u8 fsid[BTRFS_FSID_SIZE];    /* FS specific uuid */
+	u8 csum[BTRFS_CSUM_SIZE];
+	/* FS specific UUID, visible to user */
+	u8 fsid[BTRFS_FSID_SIZE];
 	__le64 bytenr; /* this block number */
 	__le64 flags;
 
@@ -240,8 +256,11 @@
 	__le64 cache_generation;
 	__le64 uuid_tree_generation;
 
+	/* the UUID written into btree blocks */
+	u8 metadata_uuid[BTRFS_FSID_SIZE];
+
 	/* future expansion */
-	__le64 reserved[30];
+	__le64 reserved[28];
 	u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
 	struct btrfs_root_backup super_roots[BTRFS_NUM_BACKUP_ROOTS];
 } __attribute__ ((__packed__));
@@ -271,7 +290,8 @@
 	 BTRFS_FEATURE_INCOMPAT_RAID56 |		\
 	 BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF |		\
 	 BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA |	\
-	 BTRFS_FEATURE_INCOMPAT_NO_HOLES)
+	 BTRFS_FEATURE_INCOMPAT_NO_HOLES	|	\
+	 BTRFS_FEATURE_INCOMPAT_METADATA_UUID)
 
 #define BTRFS_FEATURE_INCOMPAT_SAFE_SET			\
 	(BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
@@ -322,7 +342,7 @@
  * The slots array records the index of the item or block pointer
  * used while walking the tree.
  */
-enum { READA_NONE = 0, READA_BACK, READA_FORWARD };
+enum { READA_NONE, READA_BACK, READA_FORWARD };
 struct btrfs_path {
 	struct extent_buffer *nodes[BTRFS_MAX_LEVEL];
 	int slots[BTRFS_MAX_LEVEL];
@@ -366,122 +386,12 @@
 	struct btrfs_device *tgtdev;
 
 	struct mutex lock_finishing_cancel_unmount;
-	rwlock_t lock;
-	atomic_t read_locks;
-	atomic_t blocking_readers;
-	wait_queue_head_t read_lock_wq;
+	struct rw_semaphore rwsem;
 
 	struct btrfs_scrub_progress scrub_progress;
-};
 
-/* For raid type sysfs entries */
-struct raid_kobject {
-	u64 flags;
-	struct kobject kobj;
-	struct list_head list;
-};
-
-struct btrfs_space_info {
-	spinlock_t lock;
-
-	u64 total_bytes;	/* total bytes in the space,
-				   this doesn't take mirrors into account */
-	u64 bytes_used;		/* total bytes used,
-				   this doesn't take mirrors into account */
-	u64 bytes_pinned;	/* total bytes pinned, will be freed when the
-				   transaction finishes */
-	u64 bytes_reserved;	/* total bytes the allocator has reserved for
-				   current allocations */
-	u64 bytes_may_use;	/* number of bytes that may be used for
-				   delalloc/allocations */
-	u64 bytes_readonly;	/* total bytes that are read only */
-
-	u64 max_extent_size;	/* This will hold the maximum extent size of
-				   the space info if we had an ENOSPC in the
-				   allocator. */
-
-	unsigned int full:1;	/* indicates that we cannot allocate any more
-				   chunks for this space */
-	unsigned int chunk_alloc:1;	/* set if we are allocating a chunk */
-
-	unsigned int flush:1;		/* set if we are trying to make space */
-
-	unsigned int force_alloc;	/* set if we need to force a chunk
-					   alloc for this space */
-
-	u64 disk_used;		/* total bytes used on disk */
-	u64 disk_total;		/* total bytes on disk, takes mirrors into
-				   account */
-
-	u64 flags;
-
-	/*
-	 * bytes_pinned is kept in line with what is actually pinned, as in
-	 * we've called update_block_group and dropped the bytes_used counter
-	 * and increased the bytes_pinned counter.  However this means that
-	 * bytes_pinned does not reflect the bytes that will be pinned once the
-	 * delayed refs are flushed, so this counter is inc'ed every time we
-	 * call btrfs_free_extent so it is a realtime count of what will be
-	 * freed once the transaction is committed.  It will be zeroed every
-	 * time the transaction commits.
-	 */
-	struct percpu_counter total_bytes_pinned;
-
-	struct list_head list;
-	/* Protected by the spinlock 'lock'. */
-	struct list_head ro_bgs;
-	struct list_head priority_tickets;
-	struct list_head tickets;
-	/*
-	 * tickets_id just indicates the next ticket will be handled, so note
-	 * it's not stored per ticket.
-	 */
-	u64 tickets_id;
-
-	struct rw_semaphore groups_sem;
-	/* for block groups in our same type */
-	struct list_head block_groups[BTRFS_NR_RAID_TYPES];
-	wait_queue_head_t wait;
-
-	struct kobject kobj;
-	struct kobject *block_group_kobjs[BTRFS_NR_RAID_TYPES];
-};
-
-#define	BTRFS_BLOCK_RSV_GLOBAL		1
-#define	BTRFS_BLOCK_RSV_DELALLOC	2
-#define	BTRFS_BLOCK_RSV_TRANS		3
-#define	BTRFS_BLOCK_RSV_CHUNK		4
-#define	BTRFS_BLOCK_RSV_DELOPS		5
-#define	BTRFS_BLOCK_RSV_EMPTY		6
-#define	BTRFS_BLOCK_RSV_TEMP		7
-
-struct btrfs_block_rsv {
-	u64 size;
-	u64 reserved;
-	struct btrfs_space_info *space_info;
-	spinlock_t lock;
-	unsigned short full;
-	unsigned short type;
-	unsigned short failfast;
-
-	/*
-	 * Qgroup equivalent for @size @reserved
-	 *
-	 * Unlike normal @size/@reserved for inode rsv, qgroup doesn't care
-	 * about things like csum size nor how many tree blocks it will need to
-	 * reserve.
-	 *
-	 * Qgroup cares more about net change of the extent usage.
-	 *
-	 * So for one newly inserted file extent, in worst case it will cause
-	 * leaf split and level increase, nodesize for each file extent is
-	 * already too much.
-	 *
-	 * In short, qgroup_size/reserved is the upper limit of possible needed
-	 * qgroup metadata reservation.
-	 */
-	u64 qgroup_rsv_size;
-	u64 qgroup_rsv_reserved;
+	struct percpu_counter bio_counter;
+	wait_queue_head_t replace_wait;
 };
 
 /*
@@ -513,45 +423,11 @@
 };
 
 enum btrfs_caching_type {
-	BTRFS_CACHE_NO		= 0,
-	BTRFS_CACHE_STARTED	= 1,
-	BTRFS_CACHE_FAST	= 2,
-	BTRFS_CACHE_FINISHED	= 3,
-	BTRFS_CACHE_ERROR	= 4,
-};
-
-enum btrfs_disk_cache_state {
-	BTRFS_DC_WRITTEN	= 0,
-	BTRFS_DC_ERROR		= 1,
-	BTRFS_DC_CLEAR		= 2,
-	BTRFS_DC_SETUP		= 3,
-};
-
-struct btrfs_caching_control {
-	struct list_head list;
-	struct mutex mutex;
-	wait_queue_head_t wait;
-	struct btrfs_work work;
-	struct btrfs_block_group_cache *block_group;
-	u64 progress;
-	refcount_t count;
-};
-
-/* Once caching_thread() finds this much free space, it will wake up waiters. */
-#define CACHING_CTL_WAKE_UP SZ_2M
-
-struct btrfs_io_ctl {
-	void *cur, *orig;
-	struct page *page;
-	struct page **pages;
-	struct btrfs_fs_info *fs_info;
-	struct inode *inode;
-	unsigned long size;
-	int index;
-	int num_pages;
-	int entries;
-	int bitmaps;
-	unsigned check_crcs:1;
+	BTRFS_CACHE_NO,
+	BTRFS_CACHE_STARTED,
+	BTRFS_CACHE_FAST,
+	BTRFS_CACHE_FINISHED,
+	BTRFS_CACHE_ERROR,
 };
 
 /*
@@ -562,120 +438,6 @@
 	struct mutex lock;
 };
 
-struct btrfs_block_group_cache {
-	struct btrfs_key key;
-	struct btrfs_block_group_item item;
-	struct btrfs_fs_info *fs_info;
-	struct inode *inode;
-	spinlock_t lock;
-	u64 pinned;
-	u64 reserved;
-	u64 delalloc_bytes;
-	u64 bytes_super;
-	u64 flags;
-	u64 cache_generation;
-
-	/*
-	 * If the free space extent count exceeds this number, convert the block
-	 * group to bitmaps.
-	 */
-	u32 bitmap_high_thresh;
-
-	/*
-	 * If the free space extent count drops below this number, convert the
-	 * block group back to extents.
-	 */
-	u32 bitmap_low_thresh;
-
-	/*
-	 * It is just used for the delayed data space allocation because
-	 * only the data space allocation and the relative metadata update
-	 * can be done cross the transaction.
-	 */
-	struct rw_semaphore data_rwsem;
-
-	/* for raid56, this is a full stripe, without parity */
-	unsigned long full_stripe_len;
-
-	unsigned int ro;
-	unsigned int iref:1;
-	unsigned int has_caching_ctl:1;
-	unsigned int removed:1;
-
-	int disk_cache_state;
-
-	/* cache tracking stuff */
-	int cached;
-	struct btrfs_caching_control *caching_ctl;
-	u64 last_byte_to_unpin;
-
-	struct btrfs_space_info *space_info;
-
-	/* free space cache stuff */
-	struct btrfs_free_space_ctl *free_space_ctl;
-
-	/* block group cache stuff */
-	struct rb_node cache_node;
-
-	/* for block groups in the same raid type */
-	struct list_head list;
-
-	/* usage count */
-	atomic_t count;
-
-	/* List of struct btrfs_free_clusters for this block group.
-	 * Today it will only have one thing on it, but that may change
-	 */
-	struct list_head cluster_list;
-
-	/* For delayed block group creation or deletion of empty block groups */
-	struct list_head bg_list;
-
-	/* For read-only block groups */
-	struct list_head ro_list;
-
-	atomic_t trimming;
-
-	/* For dirty block groups */
-	struct list_head dirty_list;
-	struct list_head io_list;
-
-	struct btrfs_io_ctl io_ctl;
-
-	/*
-	 * Incremented when doing extent allocations and holding a read lock
-	 * on the space_info's groups_sem semaphore.
-	 * Decremented when an ordered extent that represents an IO against this
-	 * block group's range is created (after it's added to its inode's
-	 * root's list of ordered extents) or immediately after the allocation
-	 * if it's a metadata extent or fallocate extent (for these cases we
-	 * don't create ordered extents).
-	 */
-	atomic_t reservations;
-
-	/*
-	 * Incremented while holding the spinlock *lock* by a task checking if
-	 * it can perform a nocow write (incremented if the value for the *ro*
-	 * field is 0). Decremented by such tasks once they create an ordered
-	 * extent or before that if some error happens before reaching that step.
-	 * This is to prevent races between block group relocation and nocow
-	 * writes through direct IO.
-	 */
-	atomic_t nocow_writers;
-
-	/* Lock for free space tree operations. */
-	struct mutex free_space_lock;
-
-	/*
-	 * Does the block group need to be added to the free space tree?
-	 * Protected by free_space_lock.
-	 */
-	int needs_free_space;
-
-	/* Record locked full stripes for RAID5/6 block group */
-	struct btrfs_full_stripe_locks_tree full_stripe_locks_root;
-};
-
 /* delayed seq elem */
 struct seq_list {
 	struct list_head list;
@@ -691,22 +453,6 @@
 	ORPHAN_CLEANUP_DONE	= 2,
 };
 
-/* used by the raid56 code to lock stripes for read/modify/write */
-struct btrfs_stripe_hash {
-	struct list_head hash_list;
-	spinlock_t lock;
-};
-
-/* used by the raid56 code to lock stripes for read/modify/write */
-struct btrfs_stripe_hash_table {
-	struct list_head stripe_cache;
-	spinlock_t cache_lock;
-	int cache_size;
-	struct btrfs_stripe_hash table[];
-};
-
-#define BTRFS_STRIPE_HASH_TABLE_BITS 11
-
 void btrfs_init_async_reclaim_work(struct work_struct *work);
 
 /* fs_info */
@@ -716,41 +462,71 @@
 struct btrfs_balance_control;
 struct btrfs_delayed_root;
 
-#define BTRFS_FS_BARRIER			1
-#define BTRFS_FS_CLOSING_START			2
-#define BTRFS_FS_CLOSING_DONE			3
-#define BTRFS_FS_LOG_RECOVERING			4
-#define BTRFS_FS_OPEN				5
-#define BTRFS_FS_QUOTA_ENABLED			6
-#define BTRFS_FS_UPDATE_UUID_TREE_GEN		9
-#define BTRFS_FS_CREATING_FREE_SPACE_TREE	10
-#define BTRFS_FS_BTREE_ERR			11
-#define BTRFS_FS_LOG1_ERR			12
-#define BTRFS_FS_LOG2_ERR			13
-#define BTRFS_FS_QUOTA_OVERRIDE			14
-/* Used to record internally whether fs has been frozen */
-#define BTRFS_FS_FROZEN				15
-
 /*
- * Indicate that a whole-filesystem exclusive operation is running
- * (device replace, resize, device add/delete, balance)
+ * Block group or device which contains an active swapfile. Used for preventing
+ * unsafe operations while a swapfile is active.
+ *
+ * These are sorted on (ptr, inode) (note that a block group or device can
+ * contain more than one swapfile). We compare the pointer values because we
+ * don't actually care what the object is, we just need a quick check whether
+ * the object exists in the rbtree.
  */
-#define BTRFS_FS_EXCL_OP			16
+struct btrfs_swapfile_pin {
+	struct rb_node node;
+	void *ptr;
+	struct inode *inode;
+	/*
+	 * If true, ptr points to a struct btrfs_block_group_cache. Otherwise,
+	 * ptr points to a struct btrfs_device.
+	 */
+	bool is_block_group;
+};
 
-/*
- * To info transaction_kthread we need an immediate commit so it doesn't
- * need to wait for commit_interval
- */
-#define BTRFS_FS_NEED_ASYNC_COMMIT		17
+bool btrfs_pinned_by_swapfile(struct btrfs_fs_info *fs_info, void *ptr);
 
-/*
- * Indicate that balance has been set up from the ioctl and is in the main
- * phase. The fs_info::balance_ctl is initialized.
- */
-#define BTRFS_FS_BALANCE_RUNNING		18
+enum {
+	BTRFS_FS_BARRIER,
+	BTRFS_FS_CLOSING_START,
+	BTRFS_FS_CLOSING_DONE,
+	BTRFS_FS_LOG_RECOVERING,
+	BTRFS_FS_OPEN,
+	BTRFS_FS_QUOTA_ENABLED,
+	BTRFS_FS_UPDATE_UUID_TREE_GEN,
+	BTRFS_FS_CREATING_FREE_SPACE_TREE,
+	BTRFS_FS_BTREE_ERR,
+	BTRFS_FS_LOG1_ERR,
+	BTRFS_FS_LOG2_ERR,
+	BTRFS_FS_QUOTA_OVERRIDE,
+	/* Used to record internally whether fs has been frozen */
+	BTRFS_FS_FROZEN,
+	/*
+	 * Indicate that a whole-filesystem exclusive operation is running
+	 * (device replace, resize, device add/delete, balance)
+	 */
+	BTRFS_FS_EXCL_OP,
+	/*
+	 * To info transaction_kthread we need an immediate commit so it
+	 * doesn't need to wait for commit_interval
+	 */
+	BTRFS_FS_NEED_ASYNC_COMMIT,
+	/*
+	 * Indicate that balance has been set up from the ioctl and is in the
+	 * main phase. The fs_info::balance_ctl is initialized.
+	 * Set and cleared while holding fs_info::balance_mutex.
+	 */
+	BTRFS_FS_BALANCE_RUNNING,
+
+	/* Indicate that the cleaner thread is awake and doing something. */
+	BTRFS_FS_CLEANER_RUNNING,
+
+	/*
+	 * The checksumming has an optimized version and is considered fast,
+	 * so we don't need to offload checksums to workqueues.
+	 */
+	BTRFS_FS_CSUM_IMPL_FAST,
+};
 
 struct btrfs_fs_info {
-	u8 fsid[BTRFS_FSID_SIZE];
 	u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
 	unsigned long flags;
 	struct btrfs_root *extent_root;
@@ -781,7 +557,7 @@
 	struct extent_io_tree *pinned_extents;
 
 	/* logical->physical extent mapping */
-	struct btrfs_mapping_tree mapping_tree;
+	struct extent_map_tree mapping_tree;
 
 	/*
 	 * block reservation for extent, checksum, root tree and
@@ -794,6 +570,8 @@
 	struct btrfs_block_rsv chunk_block_rsv;
 	/* block reservation for delayed operations */
 	struct btrfs_block_rsv delayed_block_rsv;
+	/* block reservation for delayed refs */
+	struct btrfs_block_rsv delayed_refs_rsv;
 
 	struct btrfs_block_rsv empty_block_rsv;
 
@@ -890,7 +668,8 @@
 
 	spinlock_t delayed_iput_lock;
 	struct list_head delayed_iputs;
-	struct mutex cleaner_delayed_iput_mutex;
+	atomic_t nr_delayed_iputs;
+	wait_queue_head_t delayed_iputs_wait;
 
 	/* this protects tree_mod_seq_list */
 	spinlock_t tree_mod_seq_lock;
@@ -955,21 +734,18 @@
 	struct btrfs_workqueue *fixup_workers;
 	struct btrfs_workqueue *delayed_workers;
 
-	/* the extent workers do delayed refs on the extent allocation tree */
-	struct btrfs_workqueue *extent_workers;
 	struct task_struct *transaction_kthread;
 	struct task_struct *cleaner_kthread;
 	u32 thread_pool_size;
 
 	struct kobject *space_info_kobj;
-	struct list_head pending_raid_kobjs;
-	spinlock_t pending_raid_kobjs_lock; /* uncontended */
 
 	u64 total_pinned;
 
 	/* used to keep from writing metadata until there is a nice batch */
 	struct percpu_counter dirty_metadata_bytes;
 	struct percpu_counter delalloc_bytes;
+	struct percpu_counter dio_bytes;
 	s32 dirty_metadata_batch;
 	s32 delalloc_batch;
 
@@ -1030,10 +806,13 @@
 	atomic_t scrubs_paused;
 	atomic_t scrub_cancel_req;
 	wait_queue_head_t scrub_pause_wait;
-	int scrub_workers_refcnt;
+	/*
+	 * The worker pointers are NULL iff the refcount is 0, ie. scrub is not
+	 * running.
+	 */
+	refcount_t scrub_workers_refcnt;
 	struct btrfs_workqueue *scrub_workers;
 	struct btrfs_workqueue *scrub_wr_completion_workers;
-	struct btrfs_workqueue *scrub_nocow_workers;
 	struct btrfs_workqueue *scrub_parity_workers;
 
 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
@@ -1044,10 +823,7 @@
 
 	/* holds configuration and tracking. Protected by qgroup_lock */
 	struct rb_root qgroup_tree;
-	struct rb_root qgroup_op_tree;
 	spinlock_t qgroup_lock;
-	spinlock_t qgroup_op_lock;
-	atomic_t qgroup_op_seq;
 
 	/*
 	 * used to avoid frequently calling ulist_alloc()/ulist_free()
@@ -1094,9 +870,6 @@
 	/* device replace state */
 	struct btrfs_dev_replace dev_replace;
 
-	struct percpu_counter bio_counter;
-	wait_queue_head_t replace_wait;
-
 	struct semaphore uuid_tree_rescan_sem;
 
 	/* Used to reclaim the metadata space in the background. */
@@ -1107,20 +880,23 @@
 	struct mutex unused_bg_unpin_mutex;
 	struct mutex delete_unused_bgs_mutex;
 
-	/* For btrfs to record security options */
-	struct security_mnt_opts security_opts;
-
-	/*
-	 * Chunks that can't be freed yet (under a trim/discard operation)
-	 * and will be latter freed. Protected by fs_info->chunk_mutex.
-	 */
-	struct list_head pinned_chunks;
-
 	/* Cached block sizes */
 	u32 nodesize;
 	u32 sectorsize;
 	u32 stripesize;
 
+	/* Block groups and devices containing active swapfiles. */
+	spinlock_t swapfile_pins_lock;
+	struct rb_root swapfile_pins;
+
+	struct crypto_shash *csum_shash;
+
+	/*
+	 * Number of send operations in progress.
+	 * Updated while holding fs_info::balance_mutex.
+	 */
+	int send_in_progress;
+
 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
 	spinlock_t ref_verify_lock;
 	struct rb_root block_tree;
@@ -1140,22 +916,44 @@
 /*
  * The state of btrfs root
  */
+enum {
+	/*
+	 * btrfs_record_root_in_trans is a multi-step process, and it can race
+	 * with the balancing code.   But the race is very small, and only the
+	 * first time the root is added to each transaction.  So IN_TRANS_SETUP
+	 * is used to tell us when more checks are required
+	 */
+	BTRFS_ROOT_IN_TRANS_SETUP,
+	BTRFS_ROOT_REF_COWS,
+	BTRFS_ROOT_TRACK_DIRTY,
+	BTRFS_ROOT_IN_RADIX,
+	BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
+	BTRFS_ROOT_DEFRAG_RUNNING,
+	BTRFS_ROOT_FORCE_COW,
+	BTRFS_ROOT_MULTI_LOG_TASKS,
+	BTRFS_ROOT_DIRTY,
+	BTRFS_ROOT_DELETING,
+
+	/*
+	 * Reloc tree is orphan, only kept here for qgroup delayed subtree scan
+	 *
+	 * Set for the subvolume tree owning the reloc tree.
+	 */
+	BTRFS_ROOT_DEAD_RELOC_TREE,
+	/* Mark dead root stored on device whose cleanup needs to be resumed */
+	BTRFS_ROOT_DEAD_TREE,
+};
+
 /*
- * btrfs_record_root_in_trans is a multi-step process,
- * and it can race with the balancing code.   But the
- * race is very small, and only the first time the root
- * is added to each transaction.  So IN_TRANS_SETUP
- * is used to tell us when more checks are required
+ * Record swapped tree blocks of a subvolume tree for delayed subtree trace
+ * code. For detail check comment in fs/btrfs/qgroup.c.
  */
-#define BTRFS_ROOT_IN_TRANS_SETUP	0
-#define BTRFS_ROOT_REF_COWS		1
-#define BTRFS_ROOT_TRACK_DIRTY		2
-#define BTRFS_ROOT_IN_RADIX		3
-#define BTRFS_ROOT_ORPHAN_ITEM_INSERTED	4
-#define BTRFS_ROOT_DEFRAG_RUNNING	5
-#define BTRFS_ROOT_FORCE_COW		6
-#define BTRFS_ROOT_MULTI_LOG_TASKS	7
-#define BTRFS_ROOT_DIRTY		8
+struct btrfs_qgroup_swapped_blocks {
+	spinlock_t lock;
+	/* RM_EMPTY_ROOT() of above blocks[] */
+	bool swapped;
+	struct rb_root blocks[BTRFS_MAX_LEVEL];
+};
 
 /*
  * in ram representation of the tree.  extent_root is used for all allocations
@@ -1202,18 +1000,12 @@
 	int last_log_commit;
 	pid_t log_start_pid;
 
-	u64 objectid;
 	u64 last_trans;
 
 	u32 type;
 
 	u64 highest_objectid;
 
-#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
-	/* only used with CONFIG_BTRFS_FS_RUN_SANITY_TESTS is enabled */
-	u64 alloc_bytenr;
-#endif
-
 	u64 defrag_trans_start;
 	struct btrfs_key defrag_progress;
 	struct btrfs_key defrag_max;
@@ -1274,10 +1066,24 @@
 	u64 nr_ordered_extents;
 
 	/*
+	 * Not empty if this subvolume root has gone through tree block swap
+	 * (relocation)
+	 *
+	 * Will be used by reloc_control::dirty_subvol_roots.
+	 */
+	struct list_head reloc_dirty_list;
+
+	/*
 	 * Number of currently running SEND ioctls to prevent
 	 * manipulation with the read-only status via SUBVOL_SETFLAGS
 	 */
 	int send_in_progress;
+	/*
+	 * Number of currently running deduplication operations that have a
+	 * destination inode belonging to this root. Protected by the lock
+	 * root_item_lock.
+	 */
+	int dedupe_in_progress;
 	struct btrfs_subvolume_writers *subv_writers;
 	atomic_t will_be_snapshotted;
 	atomic_t snapshot_force_cow;
@@ -1286,6 +1092,26 @@
 	spinlock_t qgroup_meta_rsv_lock;
 	u64 qgroup_meta_rsv_pertrans;
 	u64 qgroup_meta_rsv_prealloc;
+
+	/* Number of active swapfiles */
+	atomic_t nr_swapfiles;
+
+	/* Record pairs of swapped blocks for qgroup */
+	struct btrfs_qgroup_swapped_blocks swapped_blocks;
+
+#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
+	u64 alloc_bytenr;
+#endif
+};
+
+struct btrfs_clone_extent_info {
+	u64 disk_offset;
+	u64 disk_len;
+	u64 data_offset;
+	u64 data_len;
+	u64 file_offset;
+	char *extent_buf;
+	u32 item_size;
 };
 
 struct btrfs_file_private {
@@ -1386,19 +1212,6 @@
 	btrfs_clear_opt(fs_info->mount_opt, opt);			\
 }
 
-#ifdef CONFIG_BTRFS_DEBUG
-static inline int
-btrfs_should_fragment_free_space(struct btrfs_block_group_cache *block_group)
-{
-	struct btrfs_fs_info *fs_info = block_group->fs_info;
-
-	return (btrfs_test_opt(fs_info, FRAGMENT_METADATA) &&
-		block_group->flags & BTRFS_BLOCK_GROUP_METADATA) ||
-	       (btrfs_test_opt(fs_info, FRAGMENT_DATA) &&
-		block_group->flags &  BTRFS_BLOCK_GROUP_DATA);
-}
-#endif
-
 /*
  * Requests for changes that need to be done during transaction commit.
  *
@@ -1460,6 +1273,21 @@
 
 #define BTRFS_INODE_ROOT_ITEM_INIT	(1 << 31)
 
+#define BTRFS_INODE_FLAG_MASK						\
+	(BTRFS_INODE_NODATASUM |					\
+	 BTRFS_INODE_NODATACOW |					\
+	 BTRFS_INODE_READONLY |						\
+	 BTRFS_INODE_NOCOMPRESS |					\
+	 BTRFS_INODE_PREALLOC |						\
+	 BTRFS_INODE_SYNC |						\
+	 BTRFS_INODE_IMMUTABLE |					\
+	 BTRFS_INODE_APPEND |						\
+	 BTRFS_INODE_NODUMP |						\
+	 BTRFS_INODE_NOATIME |						\
+	 BTRFS_INODE_DIRSYNC |						\
+	 BTRFS_INODE_COMPRESS |						\
+	 BTRFS_INODE_ROOT_ITEM_INIT)
+
 struct btrfs_map_token {
 	const struct extent_buffer *eb;
 	char *kaddr;
@@ -1469,8 +1297,10 @@
 #define BTRFS_BYTES_TO_BLKS(fs_info, bytes) \
 				((bytes) >> (fs_info)->sb->s_blocksize_bits)
 
-static inline void btrfs_init_map_token (struct btrfs_map_token *token)
+static inline void btrfs_init_map_token(struct btrfs_map_token *token,
+					struct extent_buffer *eb)
 {
+	token->eb = eb;
 	token->kaddr = NULL;
 }
 
@@ -1501,17 +1331,10 @@
 void btrfs_set_token_##bits(struct extent_buffer *eb, const void *ptr,	\
 			    unsigned long off, u##bits val,		\
 			    struct btrfs_map_token *token);		\
-static inline u##bits btrfs_get_##bits(const struct extent_buffer *eb,	\
-				       const void *ptr,			\
-				       unsigned long off)		\
-{									\
-	return btrfs_get_token_##bits(eb, ptr, off, NULL);		\
-}									\
-static inline void btrfs_set_##bits(struct extent_buffer *eb, void *ptr,\
-				    unsigned long off, u##bits val)	\
-{									\
-       btrfs_set_token_##bits(eb, ptr, off, val, NULL);			\
-}
+u##bits btrfs_get_##bits(const struct extent_buffer *eb,		\
+			 const void *ptr, unsigned long off);		\
+void btrfs_set_##bits(struct extent_buffer *eb, void *ptr,		\
+		      unsigned long off, u##bits val);
 
 DECLARE_BTRFS_SETGET_BITS(8)
 DECLARE_BTRFS_SETGET_BITS(16)
@@ -2053,16 +1876,6 @@
 	btrfs_disk_key_to_cpu(key, &disk_key);
 }
 
-static inline u8 btrfs_key_type(const struct btrfs_key *key)
-{
-	return key->type;
-}
-
-static inline void btrfs_set_key_type(struct btrfs_key *key, u8 val)
-{
-	key->type = val;
-}
-
 /* struct btrfs_header */
 BTRFS_SETGET_HEADER_FUNCS(header_bytenr, struct btrfs_header, bytenr, 64);
 BTRFS_SETGET_HEADER_FUNCS(header_generation, struct btrfs_header,
@@ -2083,18 +1896,16 @@
 	return (btrfs_header_flags(eb) & flag) == flag;
 }
 
-static inline int btrfs_set_header_flag(struct extent_buffer *eb, u64 flag)
+static inline void btrfs_set_header_flag(struct extent_buffer *eb, u64 flag)
 {
 	u64 flags = btrfs_header_flags(eb);
 	btrfs_set_header_flags(eb, flags | flag);
-	return (flags & flag) == flag;
 }
 
-static inline int btrfs_clear_header_flag(struct extent_buffer *eb, u64 flag)
+static inline void btrfs_clear_header_flag(struct extent_buffer *eb, u64 flag)
 {
 	u64 flags = btrfs_header_flags(eb);
 	btrfs_set_header_flags(eb, flags & ~flag);
-	return (flags & flag) == flag;
 }
 
 static inline int btrfs_header_backref_rev(const struct extent_buffer *eb)
@@ -2350,28 +2161,20 @@
 BTRFS_SETGET_STACK_FUNCS(super_uuid_tree_generation, struct btrfs_super_block,
 			 uuid_tree_generation, 64);
 
-static inline int btrfs_super_csum_size(const struct btrfs_super_block *s)
-{
-	u16 t = btrfs_super_csum_type(s);
-	/*
-	 * csum type is validated at mount time
-	 */
-	return btrfs_csum_sizes[t];
-}
-
+int btrfs_super_csum_size(const struct btrfs_super_block *s);
+const char *btrfs_super_csum_name(u16 csum_type);
 
 /*
  * The leaf data grows from end-to-front in the node.
  * this returns the address of the start of the last item,
  * which is the stop of the leaf data stack
  */
-static inline unsigned int leaf_data_end(const struct btrfs_fs_info *fs_info,
-					 const struct extent_buffer *leaf)
+static inline unsigned int leaf_data_end(const struct extent_buffer *leaf)
 {
 	u32 nr = btrfs_header_nritems(leaf);
 
 	if (nr == 0)
-		return BTRFS_LEAF_DATA_SIZE(fs_info);
+		return BTRFS_LEAF_DATA_SIZE(leaf->fs_info);
 	return btrfs_item_offset_nr(leaf, nr - 1);
 }
 
@@ -2432,30 +2235,6 @@
 	return btrfs_item_size(eb, e) - BTRFS_FILE_EXTENT_INLINE_DATA_START;
 }
 
-/* btrfs_dev_stats_item */
-static inline u64 btrfs_dev_stats_value(const struct extent_buffer *eb,
-					const struct btrfs_dev_stats_item *ptr,
-					int index)
-{
-	u64 val;
-
-	read_extent_buffer(eb, &val,
-			   offsetof(struct btrfs_dev_stats_item, values) +
-			    ((unsigned long)ptr) + (index * sizeof(u64)),
-			   sizeof(val));
-	return val;
-}
-
-static inline void btrfs_set_dev_stats_value(struct extent_buffer *eb,
-					     struct btrfs_dev_stats_item *ptr,
-					     int index, u64 val)
-{
-	write_extent_buffer(eb, &val,
-			    offsetof(struct btrfs_dev_stats_item, values) +
-			     ((unsigned long)ptr) + (index * sizeof(u64)),
-			    sizeof(val));
-}
-
 /* btrfs_qgroup_status_item */
 BTRFS_SETGET_FUNCS(qgroup_status_generation, struct btrfs_qgroup_status_item,
 		   generation, 64);
@@ -2551,6 +2330,16 @@
 	((unsigned long)(BTRFS_LEAF_DATA_OFFSET + \
 	btrfs_item_offset_nr(leaf, slot)))
 
+static inline u32 btrfs_crc32c(u32 crc, const void *address, unsigned length)
+{
+	return crc32c(crc, address, length);
+}
+
+static inline void btrfs_crc32c_final(u32 crc, u8 *result)
+{
+	put_unaligned_le32(~crc, result);
+}
+
 static inline u64 btrfs_name_hash(const char *name, int len)
 {
        return crc32c((u32)~1, name, len);
@@ -2565,12 +2354,6 @@
        return (u64) crc32c(parent_objectid, name, len);
 }
 
-static inline bool btrfs_mixed_space_info(struct btrfs_space_info *space_info)
-{
-	return ((space_info->flags & BTRFS_BLOCK_GROUP_METADATA) &&
-		(space_info->flags & BTRFS_BLOCK_GROUP_DATA));
-}
-
 static inline gfp_t btrfs_alloc_write_mask(struct address_space *mapping)
 {
 	return mapping_gfp_constraint(mapping, ~__GFP_FS);
@@ -2579,49 +2362,47 @@
 /* extent-tree.c */
 
 enum btrfs_inline_ref_type {
-	BTRFS_REF_TYPE_INVALID =	 0,
-	BTRFS_REF_TYPE_BLOCK =		 1,
-	BTRFS_REF_TYPE_DATA =		 2,
-	BTRFS_REF_TYPE_ANY =		 3,
+	BTRFS_REF_TYPE_INVALID,
+	BTRFS_REF_TYPE_BLOCK,
+	BTRFS_REF_TYPE_DATA,
+	BTRFS_REF_TYPE_ANY,
 };
 
 int btrfs_get_extent_inline_ref_type(const struct extent_buffer *eb,
 				     struct btrfs_extent_inline_ref *iref,
 				     enum btrfs_inline_ref_type is_data);
+u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset);
 
 u64 btrfs_csum_bytes_to_leaves(struct btrfs_fs_info *fs_info, u64 csum_bytes);
 
-static inline u64 btrfs_calc_trans_metadata_size(struct btrfs_fs_info *fs_info,
-						 unsigned num_items)
+/*
+ * Use this if we would be adding new items, as we could split nodes as we cow
+ * down the tree.
+ */
+static inline u64 btrfs_calc_insert_metadata_size(struct btrfs_fs_info *fs_info,
+						  unsigned num_items)
 {
 	return (u64)fs_info->nodesize * BTRFS_MAX_LEVEL * 2 * num_items;
 }
 
 /*
- * Doing a truncate won't result in new nodes or leaves, just what we need for
- * COW.
+ * Doing a truncate or a modification won't result in new nodes or leaves, just
+ * what we need for COW.
  */
-static inline u64 btrfs_calc_trunc_metadata_size(struct btrfs_fs_info *fs_info,
+static inline u64 btrfs_calc_metadata_size(struct btrfs_fs_info *fs_info,
 						 unsigned num_items)
 {
 	return (u64)fs_info->nodesize * BTRFS_MAX_LEVEL * num_items;
 }
 
-int btrfs_should_throttle_delayed_refs(struct btrfs_trans_handle *trans,
-				       struct btrfs_fs_info *fs_info);
-int btrfs_check_space_for_delayed_refs(struct btrfs_trans_handle *trans,
-				       struct btrfs_fs_info *fs_info);
-void btrfs_dec_block_group_reservations(struct btrfs_fs_info *fs_info,
-					 const u64 start);
-void btrfs_wait_block_group_reservations(struct btrfs_block_group_cache *bg);
-bool btrfs_inc_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr);
-void btrfs_dec_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr);
-void btrfs_wait_nocow_writers(struct btrfs_block_group_cache *bg);
-void btrfs_put_block_group(struct btrfs_block_group_cache *cache);
+int btrfs_add_excluded_extent(struct btrfs_fs_info *fs_info,
+			      u64 start, u64 num_bytes);
+void btrfs_free_excluded_extents(struct btrfs_block_group_cache *cache);
 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
 			   unsigned long count);
-int btrfs_async_run_delayed_refs(struct btrfs_fs_info *fs_info,
-				 unsigned long count, u64 transid, int wait);
+void btrfs_cleanup_ref_head_accounting(struct btrfs_fs_info *fs_info,
+				  struct btrfs_delayed_ref_root *delayed_refs,
+				  struct btrfs_delayed_ref_head *head);
 int btrfs_lookup_data_extent(struct btrfs_fs_info *fs_info, u64 start, u64 len);
 int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
 			     struct btrfs_fs_info *fs_info, u64 bytenr,
@@ -2630,15 +2411,9 @@
 		     u64 bytenr, u64 num, int reserved);
 int btrfs_pin_extent_for_log_replay(struct btrfs_fs_info *fs_info,
 				    u64 bytenr, u64 num_bytes);
-int btrfs_exclude_logged_extents(struct btrfs_fs_info *fs_info,
-				 struct extent_buffer *eb);
+int btrfs_exclude_logged_extents(struct extent_buffer *eb);
 int btrfs_cross_ref_exist(struct btrfs_root *root,
 			  u64 objectid, u64 offset, u64 bytenr);
-struct btrfs_block_group_cache *btrfs_lookup_block_group(
-						 struct btrfs_fs_info *info,
-						 u64 bytenr);
-void btrfs_get_block_group(struct btrfs_block_group_cache *cache);
-void btrfs_put_block_group(struct btrfs_block_group_cache *cache);
 struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
 					     struct btrfs_root *root,
 					     u64 parent, u64 root_objectid,
@@ -2664,13 +2439,9 @@
 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 		  struct extent_buffer *buf, int full_backref);
 int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
-				struct btrfs_fs_info *fs_info,
 				u64 bytenr, u64 num_bytes, u64 flags,
 				int level, int is_data);
-int btrfs_free_extent(struct btrfs_trans_handle *trans,
-		      struct btrfs_root *root,
-		      u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid,
-		      u64 owner, u64 offset);
+int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_ref *ref);
 
 int btrfs_free_reserved_extent(struct btrfs_fs_info *fs_info,
 			       u64 start, u64 len, int delalloc);
@@ -2679,35 +2450,11 @@
 void btrfs_prepare_extent_commit(struct btrfs_fs_info *fs_info);
 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans);
 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
-			 struct btrfs_root *root,
-			 u64 bytenr, u64 num_bytes, u64 parent,
-			 u64 root_objectid, u64 owner, u64 offset);
+			 struct btrfs_ref *generic_ref);
 
-int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans);
-int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
-				   struct btrfs_fs_info *fs_info);
-int btrfs_setup_space_cache(struct btrfs_trans_handle *trans,
-			    struct btrfs_fs_info *fs_info);
 int btrfs_extent_readonly(struct btrfs_fs_info *fs_info, u64 bytenr);
-int btrfs_free_block_groups(struct btrfs_fs_info *info);
-int btrfs_read_block_groups(struct btrfs_fs_info *info);
-int btrfs_can_relocate(struct btrfs_fs_info *fs_info, u64 bytenr);
-int btrfs_make_block_group(struct btrfs_trans_handle *trans,
-			   u64 bytes_used, u64 type, u64 chunk_offset,
-			   u64 size);
-void btrfs_add_raid_kobjects(struct btrfs_fs_info *fs_info);
-struct btrfs_trans_handle *btrfs_start_trans_remove_block_group(
-				struct btrfs_fs_info *fs_info,
-				const u64 chunk_offset);
-int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
-			     u64 group_start, struct extent_map *em);
-void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info);
 void btrfs_get_block_group_trimming(struct btrfs_block_group_cache *cache);
 void btrfs_put_block_group_trimming(struct btrfs_block_group_cache *cache);
-void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans);
-u64 btrfs_data_alloc_profile(struct btrfs_fs_info *fs_info);
-u64 btrfs_metadata_alloc_profile(struct btrfs_fs_info *fs_info);
-u64 btrfs_system_alloc_profile(struct btrfs_fs_info *fs_info);
 void btrfs_clear_space_info_full(struct btrfs_fs_info *info);
 
 enum btrfs_reserve_flush_enum {
@@ -2718,75 +2465,36 @@
 	 * case, use FLUSH LIMIT
 	 */
 	BTRFS_RESERVE_FLUSH_LIMIT,
+	BTRFS_RESERVE_FLUSH_EVICT,
 	BTRFS_RESERVE_FLUSH_ALL,
 };
 
 enum btrfs_flush_state {
 	FLUSH_DELAYED_ITEMS_NR	=	1,
 	FLUSH_DELAYED_ITEMS	=	2,
-	FLUSH_DELALLOC		=	3,
-	FLUSH_DELALLOC_WAIT	=	4,
-	ALLOC_CHUNK		=	5,
-	COMMIT_TRANS		=	6,
+	FLUSH_DELAYED_REFS_NR	=	3,
+	FLUSH_DELAYED_REFS	=	4,
+	FLUSH_DELALLOC		=	5,
+	FLUSH_DELALLOC_WAIT	=	6,
+	ALLOC_CHUNK		=	7,
+	ALLOC_CHUNK_FORCE	=	8,
+	RUN_DELAYED_IPUTS	=	9,
+	COMMIT_TRANS		=	10,
 };
 
-int btrfs_alloc_data_chunk_ondemand(struct btrfs_inode *inode, u64 bytes);
-int btrfs_check_data_free_space(struct inode *inode,
-			struct extent_changeset **reserved, u64 start, u64 len);
-void btrfs_free_reserved_data_space(struct inode *inode,
-			struct extent_changeset *reserved, u64 start, u64 len);
-void btrfs_delalloc_release_space(struct inode *inode,
-				  struct extent_changeset *reserved,
-				  u64 start, u64 len, bool qgroup_free);
-void btrfs_free_reserved_data_space_noquota(struct inode *inode, u64 start,
-					    u64 len);
-void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans);
 int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
 				     struct btrfs_block_rsv *rsv,
 				     int nitems, bool use_global_rsv);
 void btrfs_subvolume_release_metadata(struct btrfs_fs_info *fs_info,
 				      struct btrfs_block_rsv *rsv);
-void btrfs_delalloc_release_extents(struct btrfs_inode *inode, u64 num_bytes,
-				    bool qgroup_free);
+void btrfs_delalloc_release_extents(struct btrfs_inode *inode, u64 num_bytes);
 
 int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes);
-void btrfs_delalloc_release_metadata(struct btrfs_inode *inode, u64 num_bytes,
-				     bool qgroup_free);
-int btrfs_delalloc_reserve_space(struct inode *inode,
-			struct extent_changeset **reserved, u64 start, u64 len);
-void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv, unsigned short type);
-struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_fs_info *fs_info,
-					      unsigned short type);
-void btrfs_init_metadata_block_rsv(struct btrfs_fs_info *fs_info,
-				   struct btrfs_block_rsv *rsv,
-				   unsigned short type);
-void btrfs_free_block_rsv(struct btrfs_fs_info *fs_info,
-			  struct btrfs_block_rsv *rsv);
-int btrfs_block_rsv_add(struct btrfs_root *root,
-			struct btrfs_block_rsv *block_rsv, u64 num_bytes,
-			enum btrfs_reserve_flush_enum flush);
-int btrfs_block_rsv_check(struct btrfs_block_rsv *block_rsv, int min_factor);
-int btrfs_block_rsv_refill(struct btrfs_root *root,
-			   struct btrfs_block_rsv *block_rsv, u64 min_reserved,
-			   enum btrfs_reserve_flush_enum flush);
-int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src_rsv,
-			    struct btrfs_block_rsv *dst_rsv, u64 num_bytes,
-			    int update_size);
-int btrfs_cond_migrate_bytes(struct btrfs_fs_info *fs_info,
-			     struct btrfs_block_rsv *dest, u64 num_bytes,
-			     int min_factor);
-void btrfs_block_rsv_release(struct btrfs_fs_info *fs_info,
-			     struct btrfs_block_rsv *block_rsv,
-			     u64 num_bytes);
-int btrfs_inc_block_group_ro(struct btrfs_block_group_cache *cache);
-void btrfs_dec_block_group_ro(struct btrfs_block_group_cache *cache);
-void btrfs_put_block_group_cache(struct btrfs_fs_info *info);
 u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo);
 int btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info,
 				   u64 start, u64 end);
 int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
 			 u64 num_bytes, u64 *actual_bytes);
-int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, u64 type);
 int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range);
 
 int btrfs_init_space_info(struct btrfs_fs_info *fs_info);
@@ -2795,10 +2503,6 @@
 int btrfs_start_write_no_snapshotting(struct btrfs_root *root);
 void btrfs_end_write_no_snapshotting(struct btrfs_root *root);
 void btrfs_wait_for_snapshot_creation(struct btrfs_root *root);
-void check_system_chunk(struct btrfs_trans_handle *trans, const u64 type);
-u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
-		       u64 start, u64 end);
-void btrfs_mark_bg_unused(struct btrfs_block_group_cache *bg);
 
 /* ctree.c */
 int btrfs_bin_search(struct extent_buffer *eb, const struct btrfs_key *key,
@@ -2821,20 +2525,9 @@
 int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key,
 			 struct btrfs_path *path,
 			 u64 min_trans);
-enum btrfs_compare_tree_result {
-	BTRFS_COMPARE_TREE_NEW,
-	BTRFS_COMPARE_TREE_DELETED,
-	BTRFS_COMPARE_TREE_CHANGED,
-	BTRFS_COMPARE_TREE_SAME,
-};
-typedef int (*btrfs_changed_cb_t)(struct btrfs_path *left_path,
-				  struct btrfs_path *right_path,
-				  struct btrfs_key *key,
-				  enum btrfs_compare_tree_result result,
-				  void *ctx);
-int btrfs_compare_trees(struct btrfs_root *left_root,
-			struct btrfs_root *right_root,
-			btrfs_changed_cb_t cb, void *ctx);
+struct extent_buffer *btrfs_read_node_slot(struct extent_buffer *parent,
+					   int slot);
+
 int btrfs_cow_block(struct btrfs_trans_handle *trans,
 		    struct btrfs_root *root, struct extent_buffer *buf,
 		    struct extent_buffer *parent, int parent_slot,
@@ -2845,10 +2538,8 @@
 		      struct extent_buffer **cow_ret, u64 new_root_objectid);
 int btrfs_block_can_be_shared(struct btrfs_root *root,
 			      struct extent_buffer *buf);
-void btrfs_extend_item(struct btrfs_fs_info *fs_info, struct btrfs_path *path,
-		       u32 data_size);
-void btrfs_truncate_item(struct btrfs_fs_info *fs_info,
-			 struct btrfs_path *path, u32 new_size, int from_end);
+void btrfs_extend_item(struct btrfs_path *path, u32 data_size);
+void btrfs_truncate_item(struct btrfs_path *path, u32 new_size, int from_end);
 int btrfs_split_item(struct btrfs_trans_handle *trans,
 		     struct btrfs_root *root,
 		     struct btrfs_path *path,
@@ -2877,8 +2568,6 @@
 struct btrfs_path *btrfs_alloc_path(void);
 void btrfs_free_path(struct btrfs_path *p);
 void btrfs_set_path_blocking(struct btrfs_path *p);
-void btrfs_clear_path_blocking(struct btrfs_path *p,
-			       struct extent_buffer *held, int held_rw);
 void btrfs_unlock_up_safe(struct btrfs_path *p, int level);
 
 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
@@ -2926,8 +2615,7 @@
 {
 	return btrfs_next_old_item(root, p, 0);
 }
-int btrfs_leaf_free_space(struct btrfs_fs_info *fs_info,
-			  struct extent_buffer *leaf);
+int btrfs_leaf_free_space(struct extent_buffer *leaf);
 int __must_check btrfs_drop_snapshot(struct btrfs_root *root,
 				     struct btrfs_block_rsv *block_rsv,
 				     int update_ref, int for_reloc);
@@ -2972,7 +2660,6 @@
 	kfree(fs_info->free_space_root);
 	kfree(fs_info->super_copy);
 	kfree(fs_info->super_for_commit);
-	security_free_mnt_opts(&fs_info->security_opts);
 	kvfree(fs_info);
 }
 
@@ -3021,8 +2708,7 @@
 /* dir-item.c */
 int btrfs_check_dir_item_collision(struct btrfs_root *root, u64 dir,
 			  const char *name, int name_len);
-int btrfs_insert_dir_item(struct btrfs_trans_handle *trans,
-			  struct btrfs_root *root, const char *name,
+int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, const char *name,
 			  int name_len, struct btrfs_inode *dir,
 			  struct btrfs_key *location, u8 type, u64 index);
 struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
@@ -3090,19 +2776,18 @@
 			  u64 inode_objectid, u64 ref_objectid, int ins_len,
 			  int cow);
 
-int btrfs_find_name_in_backref(struct extent_buffer *leaf, int slot,
-			       const char *name,
-			       int name_len, struct btrfs_inode_ref **ref_ret);
-int btrfs_find_name_in_ext_backref(struct extent_buffer *leaf, int slot,
-				   u64 ref_objectid, const char *name,
-				   int name_len,
-				   struct btrfs_inode_extref **extref_ret);
-
+struct btrfs_inode_ref *btrfs_find_name_in_backref(struct extent_buffer *leaf,
+						   int slot, const char *name,
+						   int name_len);
+struct btrfs_inode_extref *btrfs_find_name_in_ext_backref(
+		struct extent_buffer *leaf, int slot, u64 ref_objectid,
+		const char *name, int name_len);
 /* file-item.c */
 struct btrfs_dio_private;
 int btrfs_del_csums(struct btrfs_trans_handle *trans,
 		    struct btrfs_fs_info *fs_info, u64 bytenr, u64 len);
-blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u32 *dst);
+blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
+				   u8 *dst);
 blk_status_t btrfs_lookup_bio_sums_dio(struct inode *inode, struct bio *bio,
 			      u64 logical_offset);
 int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
@@ -3130,8 +2815,7 @@
 
 /* inode.c */
 struct extent_map *btrfs_get_extent_fiemap(struct btrfs_inode *inode,
-		struct page *page, size_t pg_offset, u64 start,
-		u64 len, int create);
+					   u64 start, u64 len);
 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
 			      u64 *orig_start, u64 *orig_block_len,
 			      u64 *ram_bytes);
@@ -3155,18 +2839,25 @@
 			       struct inode *inode, u64 new_size,
 			       u32 min_type);
 
-int btrfs_start_delalloc_inodes(struct btrfs_root *root);
+int btrfs_start_delalloc_snapshot(struct btrfs_root *root);
 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int nr);
 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
 			      unsigned int extra_bits,
-			      struct extent_state **cached_state, int dedupe);
+			      struct extent_state **cached_state);
 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
 			     struct btrfs_root *new_root,
 			     struct btrfs_root *parent_root,
 			     u64 new_dirid);
-int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
-			 size_t size, struct bio *bio,
-			 unsigned long bio_flags);
+ void btrfs_set_delalloc_extent(struct inode *inode, struct extent_state *state,
+			       unsigned *bits);
+void btrfs_clear_delalloc_extent(struct inode *inode,
+				 struct extent_state *state, unsigned *bits);
+void btrfs_merge_delalloc_extent(struct inode *inode, struct extent_state *new,
+				 struct extent_state *other);
+void btrfs_split_delalloc_extent(struct inode *inode,
+				 struct extent_state *orig, u64 split);
+int btrfs_bio_fits_in_stripe(struct page *page, size_t size, struct bio *bio,
+			     unsigned long bio_flags);
 void btrfs_set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end);
 vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf);
 int btrfs_readpage(struct file *file, struct page *page);
@@ -3174,14 +2865,18 @@
 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc);
 struct inode *btrfs_alloc_inode(struct super_block *sb);
 void btrfs_destroy_inode(struct inode *inode);
+void btrfs_free_inode(struct inode *inode);
 int btrfs_drop_inode(struct inode *inode);
 int __init btrfs_init_cachep(void);
 void __cold btrfs_destroy_cachep(void);
+struct inode *btrfs_iget_path(struct super_block *s, struct btrfs_key *location,
+			      struct btrfs_root *root, int *new,
+			      struct btrfs_path *path);
 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
 			 struct btrfs_root *root, int *was_new);
 struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
-		struct page *page, size_t pg_offset,
-		u64 start, u64 end, int create);
+				    struct page *page, size_t pg_offset,
+				    u64 start, u64 end, int create);
 int btrfs_update_inode(struct btrfs_trans_handle *trans,
 			      struct btrfs_root *root,
 			      struct inode *inode);
@@ -3193,6 +2888,7 @@
 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size);
 void btrfs_add_delayed_iput(struct inode *inode);
 void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info);
+int btrfs_wait_on_delayed_iputs(struct btrfs_fs_info *fs_info);
 int btrfs_prealloc_file_range(struct inode *inode, int mode,
 			      u64 start, u64 num_bytes, u64 min_size,
 			      loff_t actual_len, u64 *alloc_hint);
@@ -3200,10 +2896,13 @@
 				    struct btrfs_trans_handle *trans, int mode,
 				    u64 start, u64 num_bytes, u64 min_size,
 				    loff_t actual_len, u64 *alloc_hint);
+int btrfs_run_delalloc_range(struct inode *inode, struct page *locked_page,
+		u64 start, u64 end, int *page_started, unsigned long *nr_written,
+		struct writeback_control *wbc);
+int btrfs_writepage_cow_fixup(struct page *page, u64 start, u64 end);
+void btrfs_writepage_endio_finish_ordered(struct page *page, u64 start,
+					  u64 end, int uptodate);
 extern const struct dentry_operations btrfs_dentry_operations;
-#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
-void btrfs_test_inode_set_ops(struct inode *inode);
-#endif
 
 /* ioctl.c */
 long btrfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
@@ -3218,9 +2917,6 @@
 				struct btrfs_ioctl_space_info *space);
 void btrfs_update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
 			       struct btrfs_ioctl_balance_args *bargs);
-int btrfs_dedupe_file_range(struct file *src_file, loff_t src_loff,
-			    struct file *dst_file, loff_t dst_loff,
-			    u64 olen);
 
 /* file.c */
 int __init btrfs_auto_defrag_init(void);
@@ -3243,6 +2939,10 @@
 int btrfs_drop_extents(struct btrfs_trans_handle *trans,
 		       struct btrfs_root *root, struct inode *inode, u64 start,
 		       u64 end, int drop_cache);
+int btrfs_punch_hole_range(struct inode *inode, struct btrfs_path *path,
+			   const u64 start, const u64 end,
+			   struct btrfs_clone_extent_info *clone_info,
+			   struct btrfs_trans_handle **trans_out);
 int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
 			      struct btrfs_inode *inode, u64 start, u64 end);
 int btrfs_release_file(struct inode *inode, struct file *file);
@@ -3250,19 +2950,14 @@
 		      size_t num_pages, loff_t pos, size_t write_bytes,
 		      struct extent_state **cached);
 int btrfs_fdatawrite_range(struct inode *inode, loff_t start, loff_t end);
-int btrfs_clone_file_range(struct file *file_in, loff_t pos_in,
-			   struct file *file_out, loff_t pos_out, u64 len);
+loff_t btrfs_remap_file_range(struct file *file_in, loff_t pos_in,
+			      struct file *file_out, loff_t pos_out,
+			      loff_t len, unsigned int remap_flags);
 
 /* tree-defrag.c */
 int btrfs_defrag_leaves(struct btrfs_trans_handle *trans,
 			struct btrfs_root *root);
 
-/* sysfs.c */
-int __init btrfs_init_sysfs(void);
-void __cold btrfs_exit_sysfs(void);
-int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info);
-void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info);
-
 /* super.c */
 int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
 			unsigned long new_flags);
@@ -3353,31 +3048,17 @@
 
 #if defined(CONFIG_DYNAMIC_DEBUG)
 #define btrfs_debug(fs_info, fmt, args...)				\
-do {									\
-        DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);         	\
-        if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))  	\
-		btrfs_printk(fs_info, KERN_DEBUG fmt, ##args);		\
-} while (0)
-#define btrfs_debug_in_rcu(fs_info, fmt, args...) 			\
-do {									\
-        DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); 	        \
-        if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT)) 		\
-		btrfs_printk_in_rcu(fs_info, KERN_DEBUG fmt, ##args);	\
-} while (0)
+	_dynamic_func_call_no_desc(fmt, btrfs_printk,			\
+				   fs_info, KERN_DEBUG fmt, ##args)
+#define btrfs_debug_in_rcu(fs_info, fmt, args...)			\
+	_dynamic_func_call_no_desc(fmt, btrfs_printk_in_rcu,		\
+				   fs_info, KERN_DEBUG fmt, ##args)
 #define btrfs_debug_rl_in_rcu(fs_info, fmt, args...)			\
-do {									\
-        DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);         	\
-        if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))  	\
-		btrfs_printk_rl_in_rcu(fs_info, KERN_DEBUG fmt,		\
-				       ##args);\
-} while (0)
-#define btrfs_debug_rl(fs_info, fmt, args...) 				\
-do {									\
-        DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);         	\
-        if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))  	\
-		btrfs_printk_ratelimited(fs_info, KERN_DEBUG fmt,	\
-					 ##args);			\
-} while (0)
+	_dynamic_func_call_no_desc(fmt, btrfs_printk_rl_in_rcu,		\
+				   fs_info, KERN_DEBUG fmt, ##args)
+#define btrfs_debug_rl(fs_info, fmt, args...)				\
+	_dynamic_func_call_no_desc(fmt, btrfs_printk_ratelimited,	\
+				   fs_info, KERN_DEBUG fmt, ##args)
 #elif defined(DEBUG)
 #define btrfs_debug(fs_info, fmt, args...) \
 	btrfs_printk(fs_info, KERN_DEBUG fmt, ##args)
@@ -3428,20 +3109,26 @@
 	rcu_read_unlock();					\
 } while (0)
 
-#ifdef CONFIG_BTRFS_ASSERT
-
 __cold
 static inline void assfail(const char *expr, const char *file, int line)
 {
-	pr_err("assertion failed: %s, file: %s, line: %d\n",
-	       expr, file, line);
-	BUG();
+	if (IS_ENABLED(CONFIG_BTRFS_ASSERT)) {
+		pr_err("assertion failed: %s, in %s:%d\n", expr, file, line);
+		BUG();
+	}
 }
 
 #define ASSERT(expr)	\
 	(likely(expr) ? (void)0 : assfail(#expr, __FILE__, __LINE__))
+
+/*
+ * Use that for functions that are conditionally exported for sanity tests but
+ * otherwise static
+ */
+#ifndef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
+#define EXPORT_FOR_TESTS static
 #else
-#define ASSERT(expr)	((void)0)
+#define EXPORT_FOR_TESTS
 #endif
 
 __cold
@@ -3510,10 +3197,11 @@
 /* compatibility and incompatibility defines */
 
 #define btrfs_set_fs_incompat(__fs_info, opt) \
-	__btrfs_set_fs_incompat((__fs_info), BTRFS_FEATURE_INCOMPAT_##opt)
+	__btrfs_set_fs_incompat((__fs_info), BTRFS_FEATURE_INCOMPAT_##opt, \
+				#opt)
 
 static inline void __btrfs_set_fs_incompat(struct btrfs_fs_info *fs_info,
-					   u64 flag)
+					   u64 flag, const char* name)
 {
 	struct btrfs_super_block *disk_super;
 	u64 features;
@@ -3526,18 +3214,20 @@
 		if (!(features & flag)) {
 			features |= flag;
 			btrfs_set_super_incompat_flags(disk_super, features);
-			btrfs_info(fs_info, "setting %llu feature flag",
-					 flag);
+			btrfs_info(fs_info,
+				"setting incompat feature flag for %s (0x%llx)",
+				name, flag);
 		}
 		spin_unlock(&fs_info->super_lock);
 	}
 }
 
 #define btrfs_clear_fs_incompat(__fs_info, opt) \
-	__btrfs_clear_fs_incompat((__fs_info), BTRFS_FEATURE_INCOMPAT_##opt)
+	__btrfs_clear_fs_incompat((__fs_info), BTRFS_FEATURE_INCOMPAT_##opt, \
+				  #opt)
 
 static inline void __btrfs_clear_fs_incompat(struct btrfs_fs_info *fs_info,
-					     u64 flag)
+					     u64 flag, const char* name)
 {
 	struct btrfs_super_block *disk_super;
 	u64 features;
@@ -3550,8 +3240,9 @@
 		if (features & flag) {
 			features &= ~flag;
 			btrfs_set_super_incompat_flags(disk_super, features);
-			btrfs_info(fs_info, "clearing %llu feature flag",
-					 flag);
+			btrfs_info(fs_info,
+				"clearing incompat feature flag for %s (0x%llx)",
+				name, flag);
 		}
 		spin_unlock(&fs_info->super_lock);
 	}
@@ -3568,10 +3259,11 @@
 }
 
 #define btrfs_set_fs_compat_ro(__fs_info, opt) \
-	__btrfs_set_fs_compat_ro((__fs_info), BTRFS_FEATURE_COMPAT_RO_##opt)
+	__btrfs_set_fs_compat_ro((__fs_info), BTRFS_FEATURE_COMPAT_RO_##opt, \
+				 #opt)
 
 static inline void __btrfs_set_fs_compat_ro(struct btrfs_fs_info *fs_info,
-					    u64 flag)
+					    u64 flag, const char *name)
 {
 	struct btrfs_super_block *disk_super;
 	u64 features;
@@ -3584,18 +3276,20 @@
 		if (!(features & flag)) {
 			features |= flag;
 			btrfs_set_super_compat_ro_flags(disk_super, features);
-			btrfs_info(fs_info, "setting %llu ro feature flag",
-				   flag);
+			btrfs_info(fs_info,
+				"setting compat-ro feature flag for %s (0x%llx)",
+				name, flag);
 		}
 		spin_unlock(&fs_info->super_lock);
 	}
 }
 
 #define btrfs_clear_fs_compat_ro(__fs_info, opt) \
-	__btrfs_clear_fs_compat_ro((__fs_info), BTRFS_FEATURE_COMPAT_RO_##opt)
+	__btrfs_clear_fs_compat_ro((__fs_info), BTRFS_FEATURE_COMPAT_RO_##opt, \
+				   #opt)
 
 static inline void __btrfs_clear_fs_compat_ro(struct btrfs_fs_info *fs_info,
-					      u64 flag)
+					      u64 flag, const char *name)
 {
 	struct btrfs_super_block *disk_super;
 	u64 features;
@@ -3608,8 +3302,9 @@
 		if (features & flag) {
 			features &= ~flag;
 			btrfs_set_super_compat_ro_flags(disk_super, features);
-			btrfs_info(fs_info, "clearing %llu ro feature flag",
-				   flag);
+			btrfs_info(fs_info,
+				"clearing compat-ro feature flag for %s (0x%llx)",
+				name, flag);
 		}
 		spin_unlock(&fs_info->super_lock);
 	}
@@ -3664,8 +3359,7 @@
 void btrfs_scrub_pause(struct btrfs_fs_info *fs_info);
 void btrfs_scrub_continue(struct btrfs_fs_info *fs_info);
 int btrfs_scrub_cancel(struct btrfs_fs_info *info);
-int btrfs_scrub_cancel_dev(struct btrfs_fs_info *info,
-			   struct btrfs_device *dev);
+int btrfs_scrub_cancel_dev(struct btrfs_device *dev);
 int btrfs_scrub_progress(struct btrfs_fs_info *fs_info, u64 devid,
 			 struct btrfs_scrub_progress *progress);
 static inline void btrfs_init_full_stripe_locks_tree(
@@ -3714,41 +3408,22 @@
 	return signal_pending(current);
 }
 
+#define in_range(b, first, len) ((b) >= (first) && (b) < (first) + (len))
+
 /* Sanity test specific functions */
 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
+void btrfs_test_inode_set_ops(struct inode *inode);
 void btrfs_test_destroy_inode(struct inode *inode);
-#endif
 
 static inline int btrfs_is_testing(struct btrfs_fs_info *fs_info)
 {
-#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
-	if (unlikely(test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO,
-			      &fs_info->fs_state)))
-		return 1;
-#endif
+	return test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state);
+}
+#else
+static inline int btrfs_is_testing(struct btrfs_fs_info *fs_info)
+{
 	return 0;
 }
-
-static inline void cond_wake_up(struct wait_queue_head *wq)
-{
-	/*
-	 * This implies a full smp_mb barrier, see comments for
-	 * waitqueue_active why.
-	 */
-	if (wq_has_sleeper(wq))
-		wake_up(wq);
-}
-
-static inline void cond_wake_up_nomb(struct wait_queue_head *wq)
-{
-	/*
-	 * Special case for conditional wakeup where the barrier required for
-	 * waitqueue_active is implied by some of the preceding code. Eg. one
-	 * of such atomic operations (atomic_dec_and_return, ...), or a
-	 * unlock/lock sequence, etc.
-	 */
-	if (waitqueue_active(wq))
-		wake_up(wq);
-}
+#endif
 
 #endif
diff --git a/fs/btrfs/dedupe.h b/fs/btrfs/dedupe.h
deleted file mode 100644
index 90281a7..0000000
--- a/fs/btrfs/dedupe.h
+++ /dev/null
@@ -1,12 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * Copyright (C) 2016 Fujitsu.  All rights reserved.
- */
-
-#ifndef BTRFS_DEDUPE_H
-#define BTRFS_DEDUPE_H
-
-/* later in-band dedupe will expand this struct */
-struct btrfs_dedupe_hash;
-
-#endif
diff --git a/fs/btrfs/delalloc-space.c b/fs/btrfs/delalloc-space.c
new file mode 100644
index 0000000..db9f2c5
--- /dev/null
+++ b/fs/btrfs/delalloc-space.c
@@ -0,0 +1,501 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "ctree.h"
+#include "delalloc-space.h"
+#include "block-rsv.h"
+#include "btrfs_inode.h"
+#include "space-info.h"
+#include "transaction.h"
+#include "qgroup.h"
+#include "block-group.h"
+
+int btrfs_alloc_data_chunk_ondemand(struct btrfs_inode *inode, u64 bytes)
+{
+	struct btrfs_root *root = inode->root;
+	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct btrfs_space_info *data_sinfo = fs_info->data_sinfo;
+	u64 used;
+	int ret = 0;
+	int need_commit = 2;
+	int have_pinned_space;
+
+	/* Make sure bytes are sectorsize aligned */
+	bytes = ALIGN(bytes, fs_info->sectorsize);
+
+	if (btrfs_is_free_space_inode(inode)) {
+		need_commit = 0;
+		ASSERT(current->journal_info);
+	}
+
+again:
+	/* Make sure we have enough space to handle the data first */
+	spin_lock(&data_sinfo->lock);
+	used = btrfs_space_info_used(data_sinfo, true);
+
+	if (used + bytes > data_sinfo->total_bytes) {
+		struct btrfs_trans_handle *trans;
+
+		/*
+		 * If we don't have enough free bytes in this space then we need
+		 * to alloc a new chunk.
+		 */
+		if (!data_sinfo->full) {
+			u64 alloc_target;
+
+			data_sinfo->force_alloc = CHUNK_ALLOC_FORCE;
+			spin_unlock(&data_sinfo->lock);
+
+			alloc_target = btrfs_data_alloc_profile(fs_info);
+			/*
+			 * It is ugly that we don't call nolock join
+			 * transaction for the free space inode case here.
+			 * But it is safe because we only do the data space
+			 * reservation for the free space cache in the
+			 * transaction context, the common join transaction
+			 * just increase the counter of the current transaction
+			 * handler, doesn't try to acquire the trans_lock of
+			 * the fs.
+			 */
+			trans = btrfs_join_transaction(root);
+			if (IS_ERR(trans))
+				return PTR_ERR(trans);
+
+			ret = btrfs_chunk_alloc(trans, alloc_target,
+						CHUNK_ALLOC_NO_FORCE);
+			btrfs_end_transaction(trans);
+			if (ret < 0) {
+				if (ret != -ENOSPC)
+					return ret;
+				else {
+					have_pinned_space = 1;
+					goto commit_trans;
+				}
+			}
+
+			goto again;
+		}
+
+		/*
+		 * If we don't have enough pinned space to deal with this
+		 * allocation, and no removed chunk in current transaction,
+		 * don't bother committing the transaction.
+		 */
+		have_pinned_space = __percpu_counter_compare(
+			&data_sinfo->total_bytes_pinned,
+			used + bytes - data_sinfo->total_bytes,
+			BTRFS_TOTAL_BYTES_PINNED_BATCH);
+		spin_unlock(&data_sinfo->lock);
+
+		/* Commit the current transaction and try again */
+commit_trans:
+		if (need_commit) {
+			need_commit--;
+
+			if (need_commit > 0) {
+				btrfs_start_delalloc_roots(fs_info, -1);
+				btrfs_wait_ordered_roots(fs_info, U64_MAX, 0,
+							 (u64)-1);
+			}
+
+			trans = btrfs_join_transaction(root);
+			if (IS_ERR(trans))
+				return PTR_ERR(trans);
+			if (have_pinned_space >= 0 ||
+			    test_bit(BTRFS_TRANS_HAVE_FREE_BGS,
+				     &trans->transaction->flags) ||
+			    need_commit > 0) {
+				ret = btrfs_commit_transaction(trans);
+				if (ret)
+					return ret;
+				/*
+				 * The cleaner kthread might still be doing iput
+				 * operations. Wait for it to finish so that
+				 * more space is released.  We don't need to
+				 * explicitly run the delayed iputs here because
+				 * the commit_transaction would have woken up
+				 * the cleaner.
+				 */
+				ret = btrfs_wait_on_delayed_iputs(fs_info);
+				if (ret)
+					return ret;
+				goto again;
+			} else {
+				btrfs_end_transaction(trans);
+			}
+		}
+
+		trace_btrfs_space_reservation(fs_info,
+					      "space_info:enospc",
+					      data_sinfo->flags, bytes, 1);
+		return -ENOSPC;
+	}
+	btrfs_space_info_update_bytes_may_use(fs_info, data_sinfo, bytes);
+	spin_unlock(&data_sinfo->lock);
+
+	return 0;
+}
+
+int btrfs_check_data_free_space(struct inode *inode,
+			struct extent_changeset **reserved, u64 start, u64 len)
+{
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	int ret;
+
+	/* align the range */
+	len = round_up(start + len, fs_info->sectorsize) -
+	      round_down(start, fs_info->sectorsize);
+	start = round_down(start, fs_info->sectorsize);
+
+	ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode), len);
+	if (ret < 0)
+		return ret;
+
+	/* Use new btrfs_qgroup_reserve_data to reserve precious data space. */
+	ret = btrfs_qgroup_reserve_data(inode, reserved, start, len);
+	if (ret < 0)
+		btrfs_free_reserved_data_space_noquota(inode, start, len);
+	else
+		ret = 0;
+	return ret;
+}
+
+/*
+ * Called if we need to clear a data reservation for this inode
+ * Normally in a error case.
+ *
+ * This one will *NOT* use accurate qgroup reserved space API, just for case
+ * which we can't sleep and is sure it won't affect qgroup reserved space.
+ * Like clear_bit_hook().
+ */
+void btrfs_free_reserved_data_space_noquota(struct inode *inode, u64 start,
+					    u64 len)
+{
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	struct btrfs_space_info *data_sinfo;
+
+	/* Make sure the range is aligned to sectorsize */
+	len = round_up(start + len, fs_info->sectorsize) -
+	      round_down(start, fs_info->sectorsize);
+	start = round_down(start, fs_info->sectorsize);
+
+	data_sinfo = fs_info->data_sinfo;
+	spin_lock(&data_sinfo->lock);
+	btrfs_space_info_update_bytes_may_use(fs_info, data_sinfo, -len);
+	spin_unlock(&data_sinfo->lock);
+}
+
+/*
+ * Called if we need to clear a data reservation for this inode
+ * Normally in a error case.
+ *
+ * This one will handle the per-inode data rsv map for accurate reserved
+ * space framework.
+ */
+void btrfs_free_reserved_data_space(struct inode *inode,
+			struct extent_changeset *reserved, u64 start, u64 len)
+{
+	struct btrfs_root *root = BTRFS_I(inode)->root;
+
+	/* Make sure the range is aligned to sectorsize */
+	len = round_up(start + len, root->fs_info->sectorsize) -
+	      round_down(start, root->fs_info->sectorsize);
+	start = round_down(start, root->fs_info->sectorsize);
+
+	btrfs_free_reserved_data_space_noquota(inode, start, len);
+	btrfs_qgroup_free_data(inode, reserved, start, len);
+}
+
+/**
+ * btrfs_inode_rsv_release - release any excessive reservation.
+ * @inode - the inode we need to release from.
+ * @qgroup_free - free or convert qgroup meta.
+ *   Unlike normal operation, qgroup meta reservation needs to know if we are
+ *   freeing qgroup reservation or just converting it into per-trans.  Normally
+ *   @qgroup_free is true for error handling, and false for normal release.
+ *
+ * This is the same as btrfs_block_rsv_release, except that it handles the
+ * tracepoint for the reservation.
+ */
+static void btrfs_inode_rsv_release(struct btrfs_inode *inode, bool qgroup_free)
+{
+	struct btrfs_fs_info *fs_info = inode->root->fs_info;
+	struct btrfs_block_rsv *block_rsv = &inode->block_rsv;
+	u64 released = 0;
+	u64 qgroup_to_release = 0;
+
+	/*
+	 * Since we statically set the block_rsv->size we just want to say we
+	 * are releasing 0 bytes, and then we'll just get the reservation over
+	 * the size free'd.
+	 */
+	released = __btrfs_block_rsv_release(fs_info, block_rsv, 0,
+					     &qgroup_to_release);
+	if (released > 0)
+		trace_btrfs_space_reservation(fs_info, "delalloc",
+					      btrfs_ino(inode), released, 0);
+	if (qgroup_free)
+		btrfs_qgroup_free_meta_prealloc(inode->root, qgroup_to_release);
+	else
+		btrfs_qgroup_convert_reserved_meta(inode->root,
+						   qgroup_to_release);
+}
+
+static void btrfs_calculate_inode_block_rsv_size(struct btrfs_fs_info *fs_info,
+						 struct btrfs_inode *inode)
+{
+	struct btrfs_block_rsv *block_rsv = &inode->block_rsv;
+	u64 reserve_size = 0;
+	u64 qgroup_rsv_size = 0;
+	u64 csum_leaves;
+	unsigned outstanding_extents;
+
+	lockdep_assert_held(&inode->lock);
+	outstanding_extents = inode->outstanding_extents;
+
+	/*
+	 * Insert size for the number of outstanding extents, 1 normal size for
+	 * updating the inode.
+	 */
+	if (outstanding_extents) {
+		reserve_size = btrfs_calc_insert_metadata_size(fs_info,
+						outstanding_extents);
+		reserve_size += btrfs_calc_metadata_size(fs_info, 1);
+	}
+	csum_leaves = btrfs_csum_bytes_to_leaves(fs_info,
+						 inode->csum_bytes);
+	reserve_size += btrfs_calc_insert_metadata_size(fs_info,
+							csum_leaves);
+	/*
+	 * For qgroup rsv, the calculation is very simple:
+	 * account one nodesize for each outstanding extent
+	 *
+	 * This is overestimating in most cases.
+	 */
+	qgroup_rsv_size = (u64)outstanding_extents * fs_info->nodesize;
+
+	spin_lock(&block_rsv->lock);
+	block_rsv->size = reserve_size;
+	block_rsv->qgroup_rsv_size = qgroup_rsv_size;
+	spin_unlock(&block_rsv->lock);
+}
+
+static void calc_inode_reservations(struct btrfs_fs_info *fs_info,
+				    u64 num_bytes, u64 *meta_reserve,
+				    u64 *qgroup_reserve)
+{
+	u64 nr_extents = count_max_extents(num_bytes);
+	u64 csum_leaves = btrfs_csum_bytes_to_leaves(fs_info, num_bytes);
+	u64 inode_update = btrfs_calc_metadata_size(fs_info, 1);
+
+	*meta_reserve = btrfs_calc_insert_metadata_size(fs_info,
+						nr_extents + csum_leaves);
+
+	/*
+	 * finish_ordered_io has to update the inode, so add the space required
+	 * for an inode update.
+	 */
+	*meta_reserve += inode_update;
+	*qgroup_reserve = nr_extents * fs_info->nodesize;
+}
+
+int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes)
+{
+	struct btrfs_root *root = inode->root;
+	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct btrfs_block_rsv *block_rsv = &inode->block_rsv;
+	u64 meta_reserve, qgroup_reserve;
+	unsigned nr_extents;
+	enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_FLUSH_ALL;
+	int ret = 0;
+	bool delalloc_lock = true;
+
+	/*
+	 * If we are a free space inode we need to not flush since we will be in
+	 * the middle of a transaction commit.  We also don't need the delalloc
+	 * mutex since we won't race with anybody.  We need this mostly to make
+	 * lockdep shut its filthy mouth.
+	 *
+	 * If we have a transaction open (can happen if we call truncate_block
+	 * from truncate), then we need FLUSH_LIMIT so we don't deadlock.
+	 */
+	if (btrfs_is_free_space_inode(inode)) {
+		flush = BTRFS_RESERVE_NO_FLUSH;
+		delalloc_lock = false;
+	} else {
+		if (current->journal_info)
+			flush = BTRFS_RESERVE_FLUSH_LIMIT;
+
+		if (btrfs_transaction_in_commit(fs_info))
+			schedule_timeout(1);
+	}
+
+	if (delalloc_lock)
+		mutex_lock(&inode->delalloc_mutex);
+
+	num_bytes = ALIGN(num_bytes, fs_info->sectorsize);
+
+	/*
+	 * We always want to do it this way, every other way is wrong and ends
+	 * in tears.  Pre-reserving the amount we are going to add will always
+	 * be the right way, because otherwise if we have enough parallelism we
+	 * could end up with thousands of inodes all holding little bits of
+	 * reservations they were able to make previously and the only way to
+	 * reclaim that space is to ENOSPC out the operations and clear
+	 * everything out and try again, which is bad.  This way we just
+	 * over-reserve slightly, and clean up the mess when we are done.
+	 */
+	calc_inode_reservations(fs_info, num_bytes, &meta_reserve,
+				&qgroup_reserve);
+	ret = btrfs_qgroup_reserve_meta_prealloc(root, qgroup_reserve, true);
+	if (ret)
+		goto out_fail;
+	ret = btrfs_reserve_metadata_bytes(root, block_rsv, meta_reserve, flush);
+	if (ret)
+		goto out_qgroup;
+
+	/*
+	 * Now we need to update our outstanding extents and csum bytes _first_
+	 * and then add the reservation to the block_rsv.  This keeps us from
+	 * racing with an ordered completion or some such that would think it
+	 * needs to free the reservation we just made.
+	 */
+	spin_lock(&inode->lock);
+	nr_extents = count_max_extents(num_bytes);
+	btrfs_mod_outstanding_extents(inode, nr_extents);
+	inode->csum_bytes += num_bytes;
+	btrfs_calculate_inode_block_rsv_size(fs_info, inode);
+	spin_unlock(&inode->lock);
+
+	/* Now we can safely add our space to our block rsv */
+	btrfs_block_rsv_add_bytes(block_rsv, meta_reserve, false);
+	trace_btrfs_space_reservation(root->fs_info, "delalloc",
+				      btrfs_ino(inode), meta_reserve, 1);
+
+	spin_lock(&block_rsv->lock);
+	block_rsv->qgroup_rsv_reserved += qgroup_reserve;
+	spin_unlock(&block_rsv->lock);
+
+	if (delalloc_lock)
+		mutex_unlock(&inode->delalloc_mutex);
+	return 0;
+out_qgroup:
+	btrfs_qgroup_free_meta_prealloc(root, qgroup_reserve);
+out_fail:
+	if (delalloc_lock)
+		mutex_unlock(&inode->delalloc_mutex);
+	return ret;
+}
+
+/**
+ * btrfs_delalloc_release_metadata - release a metadata reservation for an inode
+ * @inode: the inode to release the reservation for.
+ * @num_bytes: the number of bytes we are releasing.
+ * @qgroup_free: free qgroup reservation or convert it to per-trans reservation
+ *
+ * This will release the metadata reservation for an inode.  This can be called
+ * once we complete IO for a given set of bytes to release their metadata
+ * reservations, or on error for the same reason.
+ */
+void btrfs_delalloc_release_metadata(struct btrfs_inode *inode, u64 num_bytes,
+				     bool qgroup_free)
+{
+	struct btrfs_fs_info *fs_info = inode->root->fs_info;
+
+	num_bytes = ALIGN(num_bytes, fs_info->sectorsize);
+	spin_lock(&inode->lock);
+	inode->csum_bytes -= num_bytes;
+	btrfs_calculate_inode_block_rsv_size(fs_info, inode);
+	spin_unlock(&inode->lock);
+
+	if (btrfs_is_testing(fs_info))
+		return;
+
+	btrfs_inode_rsv_release(inode, qgroup_free);
+}
+
+/**
+ * btrfs_delalloc_release_extents - release our outstanding_extents
+ * @inode: the inode to balance the reservation for.
+ * @num_bytes: the number of bytes we originally reserved with
+ *
+ * When we reserve space we increase outstanding_extents for the extents we may
+ * add.  Once we've set the range as delalloc or created our ordered extents we
+ * have outstanding_extents to track the real usage, so we use this to free our
+ * temporarily tracked outstanding_extents.  This _must_ be used in conjunction
+ * with btrfs_delalloc_reserve_metadata.
+ */
+void btrfs_delalloc_release_extents(struct btrfs_inode *inode, u64 num_bytes)
+{
+	struct btrfs_fs_info *fs_info = inode->root->fs_info;
+	unsigned num_extents;
+
+	spin_lock(&inode->lock);
+	num_extents = count_max_extents(num_bytes);
+	btrfs_mod_outstanding_extents(inode, -num_extents);
+	btrfs_calculate_inode_block_rsv_size(fs_info, inode);
+	spin_unlock(&inode->lock);
+
+	if (btrfs_is_testing(fs_info))
+		return;
+
+	btrfs_inode_rsv_release(inode, true);
+}
+
+/**
+ * btrfs_delalloc_reserve_space - reserve data and metadata space for
+ * delalloc
+ * @inode: inode we're writing to
+ * @start: start range we are writing to
+ * @len: how long the range we are writing to
+ * @reserved: mandatory parameter, record actually reserved qgroup ranges of
+ * 	      current reservation.
+ *
+ * This will do the following things
+ *
+ * - reserve space in data space info for num bytes
+ *   and reserve precious corresponding qgroup space
+ *   (Done in check_data_free_space)
+ *
+ * - reserve space for metadata space, based on the number of outstanding
+ *   extents and how much csums will be needed
+ *   also reserve metadata space in a per root over-reserve method.
+ * - add to the inodes->delalloc_bytes
+ * - add it to the fs_info's delalloc inodes list.
+ *   (Above 3 all done in delalloc_reserve_metadata)
+ *
+ * Return 0 for success
+ * Return <0 for error(-ENOSPC or -EQUOT)
+ */
+int btrfs_delalloc_reserve_space(struct inode *inode,
+			struct extent_changeset **reserved, u64 start, u64 len)
+{
+	int ret;
+
+	ret = btrfs_check_data_free_space(inode, reserved, start, len);
+	if (ret < 0)
+		return ret;
+	ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), len);
+	if (ret < 0)
+		btrfs_free_reserved_data_space(inode, *reserved, start, len);
+	return ret;
+}
+
+/**
+ * btrfs_delalloc_release_space - release data and metadata space for delalloc
+ * @inode: inode we're releasing space for
+ * @start: start position of the space already reserved
+ * @len: the len of the space already reserved
+ * @release_bytes: the len of the space we consumed or didn't use
+ *
+ * This function will release the metadata space that was not used and will
+ * decrement ->delalloc_bytes and remove it from the fs_info delalloc_inodes
+ * list if there are no delalloc bytes left.
+ * Also it will handle the qgroup reserved space.
+ */
+void btrfs_delalloc_release_space(struct inode *inode,
+				  struct extent_changeset *reserved,
+				  u64 start, u64 len, bool qgroup_free)
+{
+	btrfs_delalloc_release_metadata(BTRFS_I(inode), len, qgroup_free);
+	btrfs_free_reserved_data_space(inode, reserved, start, len);
+}
diff --git a/fs/btrfs/delalloc-space.h b/fs/btrfs/delalloc-space.h
new file mode 100644
index 0000000..54466fb
--- /dev/null
+++ b/fs/btrfs/delalloc-space.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef BTRFS_DELALLOC_SPACE_H
+#define BTRFS_DELALLOC_SPACE_H
+
+struct extent_changeset;
+
+int btrfs_alloc_data_chunk_ondemand(struct btrfs_inode *inode, u64 bytes);
+int btrfs_check_data_free_space(struct inode *inode,
+			struct extent_changeset **reserved, u64 start, u64 len);
+void btrfs_free_reserved_data_space(struct inode *inode,
+			struct extent_changeset *reserved, u64 start, u64 len);
+void btrfs_delalloc_release_space(struct inode *inode,
+				  struct extent_changeset *reserved,
+				  u64 start, u64 len, bool qgroup_free);
+void btrfs_free_reserved_data_space_noquota(struct inode *inode, u64 start,
+					    u64 len);
+void btrfs_delalloc_release_metadata(struct btrfs_inode *inode, u64 num_bytes,
+				     bool qgroup_free);
+int btrfs_delalloc_reserve_space(struct inode *inode,
+			struct extent_changeset **reserved, u64 start, u64 len);
+
+#endif /* BTRFS_DELALLOC_SPACE_H */
diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
index f51b509..1f7f39b 100644
--- a/fs/btrfs/delayed-inode.c
+++ b/fs/btrfs/delayed-inode.c
@@ -6,6 +6,7 @@
 
 #include <linux/slab.h>
 #include <linux/iversion.h>
+#include "misc.h"
 #include "delayed-inode.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -42,8 +43,8 @@
 	delayed_node->root = root;
 	delayed_node->inode_id = inode_id;
 	refcount_set(&delayed_node->refs, 0);
-	delayed_node->ins_root = RB_ROOT;
-	delayed_node->del_root = RB_ROOT;
+	delayed_node->ins_root = RB_ROOT_CACHED;
+	delayed_node->del_root = RB_ROOT_CACHED;
 	mutex_init(&delayed_node->mutex);
 	INIT_LIST_HEAD(&delayed_node->n_list);
 	INIT_LIST_HEAD(&delayed_node->p_list);
@@ -390,7 +391,7 @@
 					struct btrfs_delayed_node *delayed_node,
 					struct btrfs_key *key)
 {
-	return __btrfs_lookup_delayed_item(&delayed_node->ins_root, key,
+	return __btrfs_lookup_delayed_item(&delayed_node->ins_root.rb_root, key,
 					   NULL, NULL);
 }
 
@@ -400,9 +401,10 @@
 {
 	struct rb_node **p, *node;
 	struct rb_node *parent_node = NULL;
-	struct rb_root *root;
+	struct rb_root_cached *root;
 	struct btrfs_delayed_item *item;
 	int cmp;
+	bool leftmost = true;
 
 	if (action == BTRFS_DELAYED_INSERTION_ITEM)
 		root = &delayed_node->ins_root;
@@ -410,7 +412,7 @@
 		root = &delayed_node->del_root;
 	else
 		BUG();
-	p = &root->rb_node;
+	p = &root->rb_root.rb_node;
 	node = &ins->rb_node;
 
 	while (*p) {
@@ -419,16 +421,18 @@
 				 rb_node);
 
 		cmp = btrfs_comp_cpu_keys(&item->key, &ins->key);
-		if (cmp < 0)
+		if (cmp < 0) {
 			p = &(*p)->rb_right;
-		else if (cmp > 0)
+			leftmost = false;
+		} else if (cmp > 0) {
 			p = &(*p)->rb_left;
-		else
+		} else {
 			return -EEXIST;
+		}
 	}
 
 	rb_link_node(node, parent_node, p);
-	rb_insert_color(node, root);
+	rb_insert_color_cached(node, root, leftmost);
 	ins->delayed_node = delayed_node;
 	ins->ins_or_del = action;
 
@@ -468,9 +472,12 @@
 
 static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item)
 {
-	struct rb_root *root;
+	struct rb_root_cached *root;
 	struct btrfs_delayed_root *delayed_root;
 
+	/* Not associated with any delayed_node */
+	if (!delayed_item->delayed_node)
+		return;
 	delayed_root = delayed_item->delayed_node->root->fs_info->delayed_root;
 
 	BUG_ON(!delayed_root);
@@ -482,7 +489,7 @@
 	else
 		root = &delayed_item->delayed_node->del_root;
 
-	rb_erase(&delayed_item->rb_node, root);
+	rb_erase_cached(&delayed_item->rb_node, root);
 	delayed_item->delayed_node->count--;
 
 	finish_one_item(delayed_root);
@@ -503,7 +510,7 @@
 	struct rb_node *p;
 	struct btrfs_delayed_item *item = NULL;
 
-	p = rb_first(&delayed_node->ins_root);
+	p = rb_first_cached(&delayed_node->ins_root);
 	if (p)
 		item = rb_entry(p, struct btrfs_delayed_item, rb_node);
 
@@ -516,7 +523,7 @@
 	struct rb_node *p;
 	struct btrfs_delayed_item *item = NULL;
 
-	p = rb_first(&delayed_node->del_root);
+	p = rb_first_cached(&delayed_node->del_root);
 	if (p)
 		item = rb_entry(p, struct btrfs_delayed_item, rb_node);
 
@@ -552,14 +559,14 @@
 	src_rsv = trans->block_rsv;
 	dst_rsv = &fs_info->delayed_block_rsv;
 
-	num_bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
+	num_bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
 
 	/*
 	 * Here we migrate space rsv from transaction rsv, since have already
 	 * reserved space when starting a transaction.  So no need to reserve
 	 * qgroup space here.
 	 */
-	ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, 1);
+	ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, true);
 	if (!ret) {
 		trace_btrfs_space_reservation(fs_info, "delayed_item",
 					      item->key.objectid,
@@ -606,7 +613,7 @@
 	src_rsv = trans->block_rsv;
 	dst_rsv = &fs_info->delayed_block_rsv;
 
-	num_bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
+	num_bytes = btrfs_calc_metadata_size(fs_info, 1);
 
 	/*
 	 * btrfs_dirty_inode will update the inode under btrfs_join_transaction
@@ -647,7 +654,7 @@
 		return ret;
 	}
 
-	ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, 1);
+	ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, true);
 	if (!ret) {
 		trace_btrfs_space_reservation(fs_info, "delayed_inode",
 					      btrfs_ino(inode), num_bytes, 1);
@@ -688,7 +695,6 @@
 				    struct btrfs_path *path,
 				    struct btrfs_delayed_item *item)
 {
-	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_delayed_item *curr, *next;
 	int free_space;
 	int total_data_size = 0, total_size = 0;
@@ -705,7 +711,7 @@
 	BUG_ON(!path->nodes[0]);
 
 	leaf = path->nodes[0];
-	free_space = btrfs_leaf_free_space(fs_info, leaf);
+	free_space = btrfs_leaf_free_space(leaf);
 	INIT_LIST_HEAD(&head);
 
 	next = item;
@@ -762,9 +768,6 @@
 		i++;
 	}
 
-	/* reset all the locked nodes in the patch to spinning locks. */
-	btrfs_clear_path_blocking(path, NULL, 0);
-
 	/* insert the keys of the items */
 	setup_items_for_insert(root, path, keys, data_size,
 			       total_data_size, total_size, nitems);
@@ -1462,7 +1465,7 @@
 	if (unlikely(ret)) {
 		btrfs_err(trans->fs_info,
 			  "err add delayed dir index item(name: %.*s) into the insertion tree of the delayed node(root id: %llu, inode id: %llu, errno: %d)",
-			  name_len, name, delayed_node->root->objectid,
+			  name_len, name, delayed_node->root->root_key.objectid,
 			  delayed_node->inode_id, ret);
 		BUG();
 	}
@@ -1526,15 +1529,22 @@
 	 * we have reserved enough space when we start a new transaction,
 	 * so reserving metadata failure is impossible.
 	 */
-	BUG_ON(ret);
+	if (ret < 0) {
+		btrfs_err(trans->fs_info,
+"metadata reservation failed for delayed dir item deltiona, should have been reserved");
+		btrfs_release_delayed_item(item);
+		goto end;
+	}
 
 	mutex_lock(&node->mutex);
 	ret = __btrfs_add_delayed_deletion_item(node, item);
 	if (unlikely(ret)) {
 		btrfs_err(trans->fs_info,
 			  "err add delayed dir index item(index: %llu) into the deletion tree of the delayed node(root id: %llu, inode id: %llu, errno: %d)",
-			  index, node->root->objectid, node->inode_id, ret);
-		BUG();
+			  index, node->root->root_key.objectid,
+			  node->inode_id, ret);
+		btrfs_delayed_item_release_metadata(dir->root, item);
+		btrfs_release_delayed_item(item);
 	}
 	mutex_unlock(&node->mutex);
 end:
@@ -1691,7 +1701,7 @@
 		name = (char *)(di + 1);
 		name_len = btrfs_stack_dir_name_len(di);
 
-		d_type = btrfs_filetype_table[di->type];
+		d_type = fs_ftype_to_dtype(di->type);
 		btrfs_disk_key_to_cpu(&location, &di->location);
 
 		over = !dir_emit(ctx, name, name_len,
diff --git a/fs/btrfs/delayed-inode.h b/fs/btrfs/delayed-inode.h
index 33536cd..74ae226 100644
--- a/fs/btrfs/delayed-inode.h
+++ b/fs/btrfs/delayed-inode.h
@@ -50,8 +50,8 @@
 	 * is waiting to be dealt with by the async worker.
 	 */
 	struct list_head p_list;
-	struct rb_root ins_root;
-	struct rb_root del_root;
+	struct rb_root_cached ins_root;
+	struct rb_root_cached del_root;
 	struct mutex mutex;
 	struct btrfs_inode_item inode_item;
 	refcount_t refs;
diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c
index 62ff545..df3bd88 100644
--- a/fs/btrfs/delayed-ref.c
+++ b/fs/btrfs/delayed-ref.c
@@ -10,6 +10,7 @@
 #include "delayed-ref.h"
 #include "transaction.h"
 #include "qgroup.h"
+#include "space-info.h"
 
 struct kmem_cache *btrfs_delayed_ref_head_cachep;
 struct kmem_cache *btrfs_delayed_tree_ref_cachep;
@@ -24,6 +25,179 @@
  * of hammering updates on the extent allocation tree.
  */
 
+bool btrfs_check_space_for_delayed_refs(struct btrfs_fs_info *fs_info)
+{
+	struct btrfs_block_rsv *delayed_refs_rsv = &fs_info->delayed_refs_rsv;
+	struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
+	bool ret = false;
+	u64 reserved;
+
+	spin_lock(&global_rsv->lock);
+	reserved = global_rsv->reserved;
+	spin_unlock(&global_rsv->lock);
+
+	/*
+	 * Since the global reserve is just kind of magic we don't really want
+	 * to rely on it to save our bacon, so if our size is more than the
+	 * delayed_refs_rsv and the global rsv then it's time to think about
+	 * bailing.
+	 */
+	spin_lock(&delayed_refs_rsv->lock);
+	reserved += delayed_refs_rsv->reserved;
+	if (delayed_refs_rsv->size >= reserved)
+		ret = true;
+	spin_unlock(&delayed_refs_rsv->lock);
+	return ret;
+}
+
+int btrfs_should_throttle_delayed_refs(struct btrfs_trans_handle *trans)
+{
+	u64 num_entries =
+		atomic_read(&trans->transaction->delayed_refs.num_entries);
+	u64 avg_runtime;
+	u64 val;
+
+	smp_mb();
+	avg_runtime = trans->fs_info->avg_delayed_ref_runtime;
+	val = num_entries * avg_runtime;
+	if (val >= NSEC_PER_SEC)
+		return 1;
+	if (val >= NSEC_PER_SEC / 2)
+		return 2;
+
+	return btrfs_check_space_for_delayed_refs(trans->fs_info);
+}
+
+/**
+ * btrfs_delayed_refs_rsv_release - release a ref head's reservation.
+ * @fs_info - the fs_info for our fs.
+ * @nr - the number of items to drop.
+ *
+ * This drops the delayed ref head's count from the delayed refs rsv and frees
+ * any excess reservation we had.
+ */
+void btrfs_delayed_refs_rsv_release(struct btrfs_fs_info *fs_info, int nr)
+{
+	struct btrfs_block_rsv *block_rsv = &fs_info->delayed_refs_rsv;
+	u64 num_bytes = btrfs_calc_insert_metadata_size(fs_info, nr);
+	u64 released = 0;
+
+	released = __btrfs_block_rsv_release(fs_info, block_rsv, num_bytes,
+					     NULL);
+	if (released)
+		trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv",
+					      0, released, 0);
+}
+
+/*
+ * btrfs_update_delayed_refs_rsv - adjust the size of the delayed refs rsv
+ * @trans - the trans that may have generated delayed refs
+ *
+ * This is to be called anytime we may have adjusted trans->delayed_ref_updates,
+ * it'll calculate the additional size and add it to the delayed_refs_rsv.
+ */
+void btrfs_update_delayed_refs_rsv(struct btrfs_trans_handle *trans)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_block_rsv *delayed_rsv = &fs_info->delayed_refs_rsv;
+	u64 num_bytes;
+
+	if (!trans->delayed_ref_updates)
+		return;
+
+	num_bytes = btrfs_calc_insert_metadata_size(fs_info,
+						    trans->delayed_ref_updates);
+	spin_lock(&delayed_rsv->lock);
+	delayed_rsv->size += num_bytes;
+	delayed_rsv->full = 0;
+	spin_unlock(&delayed_rsv->lock);
+	trans->delayed_ref_updates = 0;
+}
+
+/**
+ * btrfs_migrate_to_delayed_refs_rsv - transfer bytes to our delayed refs rsv.
+ * @fs_info - the fs info for our fs.
+ * @src - the source block rsv to transfer from.
+ * @num_bytes - the number of bytes to transfer.
+ *
+ * This transfers up to the num_bytes amount from the src rsv to the
+ * delayed_refs_rsv.  Any extra bytes are returned to the space info.
+ */
+void btrfs_migrate_to_delayed_refs_rsv(struct btrfs_fs_info *fs_info,
+				       struct btrfs_block_rsv *src,
+				       u64 num_bytes)
+{
+	struct btrfs_block_rsv *delayed_refs_rsv = &fs_info->delayed_refs_rsv;
+	u64 to_free = 0;
+
+	spin_lock(&src->lock);
+	src->reserved -= num_bytes;
+	src->size -= num_bytes;
+	spin_unlock(&src->lock);
+
+	spin_lock(&delayed_refs_rsv->lock);
+	if (delayed_refs_rsv->size > delayed_refs_rsv->reserved) {
+		u64 delta = delayed_refs_rsv->size -
+			delayed_refs_rsv->reserved;
+		if (num_bytes > delta) {
+			to_free = num_bytes - delta;
+			num_bytes = delta;
+		}
+	} else {
+		to_free = num_bytes;
+		num_bytes = 0;
+	}
+
+	if (num_bytes)
+		delayed_refs_rsv->reserved += num_bytes;
+	if (delayed_refs_rsv->reserved >= delayed_refs_rsv->size)
+		delayed_refs_rsv->full = 1;
+	spin_unlock(&delayed_refs_rsv->lock);
+
+	if (num_bytes)
+		trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv",
+					      0, num_bytes, 1);
+	if (to_free)
+		btrfs_space_info_free_bytes_may_use(fs_info,
+				delayed_refs_rsv->space_info, to_free);
+}
+
+/**
+ * btrfs_delayed_refs_rsv_refill - refill based on our delayed refs usage.
+ * @fs_info - the fs_info for our fs.
+ * @flush - control how we can flush for this reservation.
+ *
+ * This will refill the delayed block_rsv up to 1 items size worth of space and
+ * will return -ENOSPC if we can't make the reservation.
+ */
+int btrfs_delayed_refs_rsv_refill(struct btrfs_fs_info *fs_info,
+				  enum btrfs_reserve_flush_enum flush)
+{
+	struct btrfs_block_rsv *block_rsv = &fs_info->delayed_refs_rsv;
+	u64 limit = btrfs_calc_insert_metadata_size(fs_info, 1);
+	u64 num_bytes = 0;
+	int ret = -ENOSPC;
+
+	spin_lock(&block_rsv->lock);
+	if (block_rsv->reserved < block_rsv->size) {
+		num_bytes = block_rsv->size - block_rsv->reserved;
+		num_bytes = min(num_bytes, limit);
+	}
+	spin_unlock(&block_rsv->lock);
+
+	if (!num_bytes)
+		return 0;
+
+	ret = btrfs_reserve_metadata_bytes(fs_info->extent_root, block_rsv,
+					   num_bytes, flush);
+	if (ret)
+		return ret;
+	btrfs_block_rsv_add_bytes(block_rsv, num_bytes, 0);
+	trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv",
+				      0, num_bytes, 1);
+	return 0;
+}
+
 /*
  * compare two delayed tree backrefs with same bytenr and type
  */
@@ -101,14 +275,15 @@
 }
 
 /* insert a new ref to head ref rbtree */
-static struct btrfs_delayed_ref_head *htree_insert(struct rb_root *root,
+static struct btrfs_delayed_ref_head *htree_insert(struct rb_root_cached *root,
 						   struct rb_node *node)
 {
-	struct rb_node **p = &root->rb_node;
+	struct rb_node **p = &root->rb_root.rb_node;
 	struct rb_node *parent_node = NULL;
 	struct btrfs_delayed_ref_head *entry;
 	struct btrfs_delayed_ref_head *ins;
 	u64 bytenr;
+	bool leftmost = true;
 
 	ins = rb_entry(node, struct btrfs_delayed_ref_head, href_node);
 	bytenr = ins->bytenr;
@@ -117,26 +292,29 @@
 		entry = rb_entry(parent_node, struct btrfs_delayed_ref_head,
 				 href_node);
 
-		if (bytenr < entry->bytenr)
+		if (bytenr < entry->bytenr) {
 			p = &(*p)->rb_left;
-		else if (bytenr > entry->bytenr)
+		} else if (bytenr > entry->bytenr) {
 			p = &(*p)->rb_right;
-		else
+			leftmost = false;
+		} else {
 			return entry;
+		}
 	}
 
 	rb_link_node(node, parent_node, p);
-	rb_insert_color(node, root);
+	rb_insert_color_cached(node, root, leftmost);
 	return NULL;
 }
 
-static struct btrfs_delayed_ref_node* tree_insert(struct rb_root *root,
+static struct btrfs_delayed_ref_node* tree_insert(struct rb_root_cached *root,
 		struct btrfs_delayed_ref_node *ins)
 {
-	struct rb_node **p = &root->rb_node;
+	struct rb_node **p = &root->rb_root.rb_node;
 	struct rb_node *node = &ins->ref_node;
 	struct rb_node *parent_node = NULL;
 	struct btrfs_delayed_ref_node *entry;
+	bool leftmost = true;
 
 	while (*p) {
 		int comp;
@@ -145,32 +323,49 @@
 		entry = rb_entry(parent_node, struct btrfs_delayed_ref_node,
 				 ref_node);
 		comp = comp_refs(ins, entry, true);
-		if (comp < 0)
+		if (comp < 0) {
 			p = &(*p)->rb_left;
-		else if (comp > 0)
+		} else if (comp > 0) {
 			p = &(*p)->rb_right;
-		else
+			leftmost = false;
+		} else {
 			return entry;
+		}
 	}
 
 	rb_link_node(node, parent_node, p);
-	rb_insert_color(node, root);
+	rb_insert_color_cached(node, root, leftmost);
 	return NULL;
 }
 
-/*
- * find an head entry based on bytenr. This returns the delayed ref
- * head if it was able to find one, or NULL if nothing was in that spot.
- * If return_bigger is given, the next bigger entry is returned if no exact
- * match is found.
- */
-static struct btrfs_delayed_ref_head *
-find_ref_head(struct rb_root *root, u64 bytenr,
-	      int return_bigger)
+static struct btrfs_delayed_ref_head *find_first_ref_head(
+		struct btrfs_delayed_ref_root *dr)
 {
 	struct rb_node *n;
 	struct btrfs_delayed_ref_head *entry;
 
+	n = rb_first_cached(&dr->href_root);
+	if (!n)
+		return NULL;
+
+	entry = rb_entry(n, struct btrfs_delayed_ref_head, href_node);
+
+	return entry;
+}
+
+/*
+ * Find a head entry based on bytenr. This returns the delayed ref head if it
+ * was able to find one, or NULL if nothing was in that spot.  If return_bigger
+ * is given, the next bigger entry is returned if no exact match is found.
+ */
+static struct btrfs_delayed_ref_head *find_ref_head(
+		struct btrfs_delayed_ref_root *dr, u64 bytenr,
+		bool return_bigger)
+{
+	struct rb_root *root = &dr->href_root.rb_root;
+	struct rb_node *n;
+	struct btrfs_delayed_ref_head *entry;
+
 	n = root->rb_node;
 	entry = NULL;
 	while (n) {
@@ -187,22 +382,18 @@
 		if (bytenr > entry->bytenr) {
 			n = rb_next(&entry->href_node);
 			if (!n)
-				n = rb_first(root);
+				return NULL;
 			entry = rb_entry(n, struct btrfs_delayed_ref_head,
 					 href_node);
-			return entry;
 		}
 		return entry;
 	}
 	return NULL;
 }
 
-int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
+int btrfs_delayed_ref_lock(struct btrfs_delayed_ref_root *delayed_refs,
 			   struct btrfs_delayed_ref_head *head)
 {
-	struct btrfs_delayed_ref_root *delayed_refs;
-
-	delayed_refs = &trans->transaction->delayed_refs;
 	lockdep_assert_held(&delayed_refs->lock);
 	if (mutex_trylock(&head->mutex))
 		return 0;
@@ -227,15 +418,13 @@
 				    struct btrfs_delayed_ref_node *ref)
 {
 	lockdep_assert_held(&head->lock);
-	rb_erase(&ref->ref_node, &head->ref_tree);
+	rb_erase_cached(&ref->ref_node, &head->ref_tree);
 	RB_CLEAR_NODE(&ref->ref_node);
 	if (!list_empty(&ref->add_list))
 		list_del(&ref->add_list);
 	ref->in_tree = 0;
 	btrfs_put_delayed_ref(ref);
 	atomic_dec(&delayed_refs->num_entries);
-	if (trans->delayed_ref_updates)
-		trans->delayed_ref_updates--;
 }
 
 static bool merge_ref(struct btrfs_trans_handle *trans,
@@ -296,7 +485,7 @@
 
 	lockdep_assert_held(&head->lock);
 
-	if (RB_EMPTY_ROOT(&head->ref_tree))
+	if (RB_EMPTY_ROOT(&head->ref_tree.rb_root))
 		return;
 
 	/* We don't have too many refs to merge for data. */
@@ -314,7 +503,8 @@
 	spin_unlock(&fs_info->tree_mod_seq_lock);
 
 again:
-	for (node = rb_first(&head->ref_tree); node; node = rb_next(node)) {
+	for (node = rb_first_cached(&head->ref_tree); node;
+	     node = rb_next(node)) {
 		ref = rb_entry(node, struct btrfs_delayed_ref_node, ref_node);
 		if (seq && ref->seq >= seq)
 			continue;
@@ -345,40 +535,29 @@
 	return ret;
 }
 
-struct btrfs_delayed_ref_head *
-btrfs_select_ref_head(struct btrfs_trans_handle *trans)
+struct btrfs_delayed_ref_head *btrfs_select_ref_head(
+		struct btrfs_delayed_ref_root *delayed_refs)
 {
-	struct btrfs_delayed_ref_root *delayed_refs;
 	struct btrfs_delayed_ref_head *head;
-	u64 start;
-	bool loop = false;
-
-	delayed_refs = &trans->transaction->delayed_refs;
 
 again:
-	start = delayed_refs->run_delayed_start;
-	head = find_ref_head(&delayed_refs->href_root, start, 1);
-	if (!head && !loop) {
+	head = find_ref_head(delayed_refs, delayed_refs->run_delayed_start,
+			     true);
+	if (!head && delayed_refs->run_delayed_start != 0) {
 		delayed_refs->run_delayed_start = 0;
-		start = 0;
-		loop = true;
-		head = find_ref_head(&delayed_refs->href_root, start, 1);
-		if (!head)
-			return NULL;
-	} else if (!head && loop) {
-		return NULL;
+		head = find_first_ref_head(delayed_refs);
 	}
+	if (!head)
+		return NULL;
 
 	while (head->processing) {
 		struct rb_node *node;
 
 		node = rb_next(&head->href_node);
 		if (!node) {
-			if (loop)
+			if (delayed_refs->run_delayed_start == 0)
 				return NULL;
 			delayed_refs->run_delayed_start = 0;
-			start = 0;
-			loop = true;
 			goto again;
 		}
 		head = rb_entry(node, struct btrfs_delayed_ref_head,
@@ -393,6 +572,20 @@
 	return head;
 }
 
+void btrfs_delete_ref_head(struct btrfs_delayed_ref_root *delayed_refs,
+			   struct btrfs_delayed_ref_head *head)
+{
+	lockdep_assert_held(&delayed_refs->lock);
+	lockdep_assert_held(&head->lock);
+
+	rb_erase_cached(&head->href_node, &delayed_refs->href_root);
+	RB_CLEAR_NODE(&head->href_node);
+	atomic_dec(&delayed_refs->num_entries);
+	delayed_refs->num_heads--;
+	if (head->processing == 0)
+		delayed_refs->num_heads_ready--;
+}
+
 /*
  * Helper to insert the ref_node to the tail or merge with tail.
  *
@@ -446,7 +639,6 @@
 	if (ref->action == BTRFS_ADD_DELAYED_REF)
 		list_add_tail(&ref->add_list, &href->ref_add_list);
 	atomic_inc(&root->num_entries);
-	trans->delayed_ref_updates++;
 	spin_unlock(&href->lock);
 	return ret;
 }
@@ -455,12 +647,14 @@
  * helper function to update the accounting in the head ref
  * existing and update must have the same bytenr
  */
-static noinline void
-update_existing_head_ref(struct btrfs_delayed_ref_root *delayed_refs,
+static noinline void update_existing_head_ref(struct btrfs_trans_handle *trans,
 			 struct btrfs_delayed_ref_head *existing,
 			 struct btrfs_delayed_ref_head *update,
 			 int *old_ref_mod_ret)
 {
+	struct btrfs_delayed_ref_root *delayed_refs =
+		&trans->transaction->delayed_refs;
+	struct btrfs_fs_info *fs_info = trans->fs_info;
 	int old_ref_mod;
 
 	BUG_ON(existing->is_data != update->is_data);
@@ -518,10 +712,18 @@
 	 * versa we need to make sure to adjust pending_csums accordingly.
 	 */
 	if (existing->is_data) {
-		if (existing->total_ref_mod >= 0 && old_ref_mod < 0)
+		u64 csum_leaves =
+			btrfs_csum_bytes_to_leaves(fs_info,
+						   existing->num_bytes);
+
+		if (existing->total_ref_mod >= 0 && old_ref_mod < 0) {
 			delayed_refs->pending_csums -= existing->num_bytes;
-		if (existing->total_ref_mod < 0 && old_ref_mod >= 0)
+			btrfs_delayed_refs_rsv_release(fs_info, csum_leaves);
+		}
+		if (existing->total_ref_mod < 0 && old_ref_mod >= 0) {
 			delayed_refs->pending_csums += existing->num_bytes;
+			trans->delayed_ref_updates += csum_leaves;
+		}
 	}
 	spin_unlock(&existing->lock);
 }
@@ -569,22 +771,19 @@
 	head_ref->must_insert_reserved = must_insert_reserved;
 	head_ref->is_data = is_data;
 	head_ref->is_system = is_system;
-	head_ref->ref_tree = RB_ROOT;
+	head_ref->ref_tree = RB_ROOT_CACHED;
 	INIT_LIST_HEAD(&head_ref->ref_add_list);
 	RB_CLEAR_NODE(&head_ref->href_node);
 	head_ref->processing = 0;
 	head_ref->total_ref_mod = count_mod;
-	head_ref->qgroup_reserved = 0;
-	head_ref->qgroup_ref_root = 0;
 	spin_lock_init(&head_ref->lock);
 	mutex_init(&head_ref->mutex);
 
 	if (qrecord) {
 		if (ref_root && reserved) {
-			head_ref->qgroup_ref_root = ref_root;
-			head_ref->qgroup_reserved = reserved;
+			qrecord->data_rsv = reserved;
+			qrecord->data_rsv_refroot = ref_root;
 		}
-
 		qrecord->bytenr = bytenr;
 		qrecord->num_bytes = num_bytes;
 		qrecord->old_roots = NULL;
@@ -623,11 +822,7 @@
 	existing = htree_insert(&delayed_refs->href_root,
 				&head_ref->href_node);
 	if (existing) {
-		WARN_ON(qrecord && head_ref->qgroup_ref_root
-			&& head_ref->qgroup_reserved
-			&& existing->qgroup_ref_root
-			&& existing->qgroup_reserved);
-		update_existing_head_ref(delayed_refs, existing, head_ref,
+		update_existing_head_ref(trans, existing, head_ref,
 					 old_ref_mod);
 		/*
 		 * we've updated the existing ref, free the newly
@@ -638,8 +833,12 @@
 	} else {
 		if (old_ref_mod)
 			*old_ref_mod = 0;
-		if (head_ref->is_data && head_ref->ref_mod < 0)
+		if (head_ref->is_data && head_ref->ref_mod < 0) {
 			delayed_refs->pending_csums += head_ref->num_bytes;
+			trans->delayed_ref_updates +=
+				btrfs_csum_bytes_to_leaves(trans->fs_info,
+							   head_ref->num_bytes);
+		}
 		delayed_refs->num_heads++;
 		delayed_refs->num_heads_ready++;
 		atomic_inc(&delayed_refs->num_entries);
@@ -710,8 +909,7 @@
  * transaction commits.
  */
 int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans,
-			       u64 bytenr, u64 num_bytes, u64 parent,
-			       u64 ref_root,  int level, int action,
+			       struct btrfs_ref *generic_ref,
 			       struct btrfs_delayed_extent_op *extent_op,
 			       int *old_ref_mod, int *new_ref_mod)
 {
@@ -721,10 +919,18 @@
 	struct btrfs_delayed_ref_root *delayed_refs;
 	struct btrfs_qgroup_extent_record *record = NULL;
 	int qrecord_inserted;
-	bool is_system = (ref_root == BTRFS_CHUNK_TREE_OBJECTID);
+	bool is_system;
+	int action = generic_ref->action;
+	int level = generic_ref->tree_ref.level;
 	int ret;
+	u64 bytenr = generic_ref->bytenr;
+	u64 num_bytes = generic_ref->len;
+	u64 parent = generic_ref->parent;
 	u8 ref_type;
 
+	is_system = (generic_ref->real_root == BTRFS_CHUNK_TREE_OBJECTID);
+
+	ASSERT(generic_ref->type == BTRFS_REF_METADATA && generic_ref->action);
 	BUG_ON(extent_op && extent_op->is_data);
 	ref = kmem_cache_alloc(btrfs_delayed_tree_ref_cachep, GFP_NOFS);
 	if (!ref)
@@ -737,8 +943,10 @@
 	}
 
 	if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) &&
-	    is_fstree(ref_root)) {
-		record = kmalloc(sizeof(*record), GFP_NOFS);
+	    is_fstree(generic_ref->real_root) &&
+	    is_fstree(generic_ref->tree_ref.root) &&
+	    !generic_ref->skip_qgroup) {
+		record = kzalloc(sizeof(*record), GFP_NOFS);
 		if (!record) {
 			kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
 			kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref);
@@ -752,13 +960,14 @@
 		ref_type = BTRFS_TREE_BLOCK_REF_KEY;
 
 	init_delayed_ref_common(fs_info, &ref->node, bytenr, num_bytes,
-				ref_root, action, ref_type);
-	ref->root = ref_root;
+				generic_ref->tree_ref.root, action, ref_type);
+	ref->root = generic_ref->tree_ref.root;
 	ref->parent = parent;
 	ref->level = level;
 
 	init_delayed_ref_head(head_ref, record, bytenr, num_bytes,
-			      ref_root, 0, action, false, is_system);
+			      generic_ref->tree_ref.root, 0, action, false,
+			      is_system);
 	head_ref->extent_op = extent_op;
 
 	delayed_refs = &trans->transaction->delayed_refs;
@@ -775,6 +984,12 @@
 	ret = insert_delayed_ref(trans, delayed_refs, head_ref, &ref->node);
 	spin_unlock(&delayed_refs->lock);
 
+	/*
+	 * Need to update the delayed_refs_rsv with any changes we may have
+	 * made.
+	 */
+	btrfs_update_delayed_refs_rsv(trans);
+
 	trace_add_delayed_tree_ref(fs_info, &ref->node, ref,
 				   action == BTRFS_ADD_DELAYED_EXTENT ?
 				   BTRFS_ADD_DELAYED_REF : action);
@@ -791,10 +1006,9 @@
  * add a delayed data ref. it's similar to btrfs_add_delayed_tree_ref.
  */
 int btrfs_add_delayed_data_ref(struct btrfs_trans_handle *trans,
-			       u64 bytenr, u64 num_bytes,
-			       u64 parent, u64 ref_root,
-			       u64 owner, u64 offset, u64 reserved, int action,
-			       int *old_ref_mod, int *new_ref_mod)
+			       struct btrfs_ref *generic_ref,
+			       u64 reserved, int *old_ref_mod,
+			       int *new_ref_mod)
 {
 	struct btrfs_fs_info *fs_info = trans->fs_info;
 	struct btrfs_delayed_data_ref *ref;
@@ -802,9 +1016,17 @@
 	struct btrfs_delayed_ref_root *delayed_refs;
 	struct btrfs_qgroup_extent_record *record = NULL;
 	int qrecord_inserted;
+	int action = generic_ref->action;
 	int ret;
+	u64 bytenr = generic_ref->bytenr;
+	u64 num_bytes = generic_ref->len;
+	u64 parent = generic_ref->parent;
+	u64 ref_root = generic_ref->data_ref.ref_root;
+	u64 owner = generic_ref->data_ref.ino;
+	u64 offset = generic_ref->data_ref.offset;
 	u8 ref_type;
 
+	ASSERT(generic_ref->type == BTRFS_REF_DATA && action);
 	ref = kmem_cache_alloc(btrfs_delayed_data_ref_cachep, GFP_NOFS);
 	if (!ref)
 		return -ENOMEM;
@@ -828,8 +1050,10 @@
 	}
 
 	if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) &&
-	    is_fstree(ref_root)) {
-		record = kmalloc(sizeof(*record), GFP_NOFS);
+	    is_fstree(ref_root) &&
+	    is_fstree(generic_ref->real_root) &&
+	    !generic_ref->skip_qgroup) {
+		record = kzalloc(sizeof(*record), GFP_NOFS);
 		if (!record) {
 			kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
 			kmem_cache_free(btrfs_delayed_ref_head_cachep,
@@ -856,6 +1080,12 @@
 	ret = insert_delayed_ref(trans, delayed_refs, head_ref, &ref->node);
 	spin_unlock(&delayed_refs->lock);
 
+	/*
+	 * Need to update the delayed_refs_rsv with any changes we may have
+	 * made.
+	 */
+	btrfs_update_delayed_refs_rsv(trans);
+
 	trace_add_delayed_data_ref(trans->fs_info, &ref->node, ref,
 				   action == BTRFS_ADD_DELAYED_EXTENT ?
 				   BTRFS_ADD_DELAYED_REF : action);
@@ -868,8 +1098,7 @@
 	return 0;
 }
 
-int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
-				struct btrfs_trans_handle *trans,
+int btrfs_add_delayed_extent_op(struct btrfs_trans_handle *trans,
 				u64 bytenr, u64 num_bytes,
 				struct btrfs_delayed_extent_op *extent_op)
 {
@@ -892,18 +1121,25 @@
 			     NULL, NULL, NULL);
 
 	spin_unlock(&delayed_refs->lock);
+
+	/*
+	 * Need to update the delayed_refs_rsv with any changes we may have
+	 * made.
+	 */
+	btrfs_update_delayed_refs_rsv(trans);
 	return 0;
 }
 
 /*
- * this does a simple search for the head node for a given extent.
- * It must be called with the delayed ref spinlock held, and it returns
- * the head node if any where found, or NULL if not.
+ * This does a simple search for the head node for a given extent.  Returns the
+ * head node if found, or NULL if not.
  */
 struct btrfs_delayed_ref_head *
 btrfs_find_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_refs, u64 bytenr)
 {
-	return find_ref_head(&delayed_refs->href_root, bytenr, 0);
+	lockdep_assert_held(&delayed_refs->lock);
+
+	return find_ref_head(delayed_refs, bytenr, false);
 }
 
 void __cold btrfs_delayed_ref_exit(void)
diff --git a/fs/btrfs/delayed-ref.h b/fs/btrfs/delayed-ref.h
index d9f2a4e..1c977e6 100644
--- a/fs/btrfs/delayed-ref.h
+++ b/fs/btrfs/delayed-ref.h
@@ -79,7 +79,7 @@
 	struct mutex mutex;
 
 	spinlock_t lock;
-	struct rb_root ref_tree;
+	struct rb_root_cached ref_tree;
 	/* accumulate add BTRFS_ADD_DELAYED_REF nodes to this ref_add_list. */
 	struct list_head ref_add_list;
 
@@ -103,17 +103,6 @@
 	int ref_mod;
 
 	/*
-	 * For qgroup reserved space freeing.
-	 *
-	 * ref_root and reserved will be recorded after
-	 * BTRFS_ADD_DELAYED_EXTENT is called.
-	 * And will be used to free reserved qgroup space at
-	 * run_delayed_refs() time.
-	 */
-	u64 qgroup_ref_root;
-	u64 qgroup_reserved;
-
-	/*
 	 * when a new extent is allocated, it is just reserved in memory
 	 * The actual extent isn't inserted into the extent allocation tree
 	 * until the delayed ref is processed.  must_insert_reserved is
@@ -148,7 +137,7 @@
 
 struct btrfs_delayed_ref_root {
 	/* head ref rbtree */
-	struct rb_root href_root;
+	struct rb_root_cached href_root;
 
 	/* dirty extent records */
 	struct rb_root dirty_extent_root;
@@ -187,6 +176,83 @@
 	u64 qgroup_to_skip;
 };
 
+enum btrfs_ref_type {
+	BTRFS_REF_NOT_SET,
+	BTRFS_REF_DATA,
+	BTRFS_REF_METADATA,
+	BTRFS_REF_LAST,
+};
+
+struct btrfs_data_ref {
+	/* For EXTENT_DATA_REF */
+
+	/* Root which refers to this data extent */
+	u64 ref_root;
+
+	/* Inode which refers to this data extent */
+	u64 ino;
+
+	/*
+	 * file_offset - extent_offset
+	 *
+	 * file_offset is the key.offset of the EXTENT_DATA key.
+	 * extent_offset is btrfs_file_extent_offset() of the EXTENT_DATA data.
+	 */
+	u64 offset;
+};
+
+struct btrfs_tree_ref {
+	/*
+	 * Level of this tree block
+	 *
+	 * Shared for skinny (TREE_BLOCK_REF) and normal tree ref.
+	 */
+	int level;
+
+	/*
+	 * Root which refers to this tree block.
+	 *
+	 * For TREE_BLOCK_REF (skinny metadata, either inline or keyed)
+	 */
+	u64 root;
+
+	/* For non-skinny metadata, no special member needed */
+};
+
+struct btrfs_ref {
+	enum btrfs_ref_type type;
+	int action;
+
+	/*
+	 * Whether this extent should go through qgroup record.
+	 *
+	 * Normally false, but for certain cases like delayed subtree scan,
+	 * setting this flag can hugely reduce qgroup overhead.
+	 */
+	bool skip_qgroup;
+
+	/*
+	 * Optional. For which root is this modification.
+	 * Mostly used for qgroup optimization.
+	 *
+	 * When unset, data/tree ref init code will populate it.
+	 * In certain cases, we're modifying reference for a different root.
+	 * E.g. COW fs tree blocks for balance.
+	 * In that case, tree_ref::root will be fs tree, but we're doing this
+	 * for reloc tree, then we should set @real_root to reloc tree.
+	 */
+	u64 real_root;
+	u64 bytenr;
+	u64 len;
+
+	/* Bytenr of the parent tree block */
+	u64 parent;
+	union {
+		struct btrfs_data_ref data_ref;
+		struct btrfs_tree_ref tree_ref;
+	};
+};
+
 extern struct kmem_cache *btrfs_delayed_ref_head_cachep;
 extern struct kmem_cache *btrfs_delayed_tree_ref_cachep;
 extern struct kmem_cache *btrfs_delayed_data_ref_cachep;
@@ -195,6 +261,38 @@
 int __init btrfs_delayed_ref_init(void);
 void __cold btrfs_delayed_ref_exit(void);
 
+static inline void btrfs_init_generic_ref(struct btrfs_ref *generic_ref,
+				int action, u64 bytenr, u64 len, u64 parent)
+{
+	generic_ref->action = action;
+	generic_ref->bytenr = bytenr;
+	generic_ref->len = len;
+	generic_ref->parent = parent;
+}
+
+static inline void btrfs_init_tree_ref(struct btrfs_ref *generic_ref,
+				int level, u64 root)
+{
+	/* If @real_root not set, use @root as fallback */
+	if (!generic_ref->real_root)
+		generic_ref->real_root = root;
+	generic_ref->tree_ref.level = level;
+	generic_ref->tree_ref.root = root;
+	generic_ref->type = BTRFS_REF_METADATA;
+}
+
+static inline void btrfs_init_data_ref(struct btrfs_ref *generic_ref,
+				u64 ref_root, u64 ino, u64 offset)
+{
+	/* If @real_root not set, use @root as fallback */
+	if (!generic_ref->real_root)
+		generic_ref->real_root = ref_root;
+	generic_ref->data_ref.ref_root = ref_root;
+	generic_ref->data_ref.ino = ino;
+	generic_ref->data_ref.offset = offset;
+	generic_ref->type = BTRFS_REF_DATA;
+}
+
 static inline struct btrfs_delayed_extent_op *
 btrfs_alloc_delayed_extent_op(void)
 {
@@ -235,17 +333,14 @@
 }
 
 int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans,
-			       u64 bytenr, u64 num_bytes, u64 parent,
-			       u64 ref_root, int level, int action,
+			       struct btrfs_ref *generic_ref,
 			       struct btrfs_delayed_extent_op *extent_op,
 			       int *old_ref_mod, int *new_ref_mod);
 int btrfs_add_delayed_data_ref(struct btrfs_trans_handle *trans,
-			       u64 bytenr, u64 num_bytes,
-			       u64 parent, u64 ref_root,
-			       u64 owner, u64 offset, u64 reserved, int action,
-			       int *old_ref_mod, int *new_ref_mod);
-int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
-				struct btrfs_trans_handle *trans,
+			       struct btrfs_ref *generic_ref,
+			       u64 reserved, int *old_ref_mod,
+			       int *new_ref_mod);
+int btrfs_add_delayed_extent_op(struct btrfs_trans_handle *trans,
 				u64 bytenr, u64 num_bytes,
 				struct btrfs_delayed_extent_op *extent_op);
 void btrfs_merge_delayed_refs(struct btrfs_trans_handle *trans,
@@ -255,19 +350,30 @@
 struct btrfs_delayed_ref_head *
 btrfs_find_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_refs,
 			    u64 bytenr);
-int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
+int btrfs_delayed_ref_lock(struct btrfs_delayed_ref_root *delayed_refs,
 			   struct btrfs_delayed_ref_head *head);
 static inline void btrfs_delayed_ref_unlock(struct btrfs_delayed_ref_head *head)
 {
 	mutex_unlock(&head->mutex);
 }
+void btrfs_delete_ref_head(struct btrfs_delayed_ref_root *delayed_refs,
+			   struct btrfs_delayed_ref_head *head);
 
-
-struct btrfs_delayed_ref_head *
-btrfs_select_ref_head(struct btrfs_trans_handle *trans);
+struct btrfs_delayed_ref_head *btrfs_select_ref_head(
+		struct btrfs_delayed_ref_root *delayed_refs);
 
 int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info, u64 seq);
 
+void btrfs_delayed_refs_rsv_release(struct btrfs_fs_info *fs_info, int nr);
+void btrfs_update_delayed_refs_rsv(struct btrfs_trans_handle *trans);
+int btrfs_delayed_refs_rsv_refill(struct btrfs_fs_info *fs_info,
+				  enum btrfs_reserve_flush_enum flush);
+void btrfs_migrate_to_delayed_refs_rsv(struct btrfs_fs_info *fs_info,
+				       struct btrfs_block_rsv *src,
+				       u64 num_bytes);
+int btrfs_should_throttle_delayed_refs(struct btrfs_trans_handle *trans);
+bool btrfs_check_space_for_delayed_refs(struct btrfs_fs_info *fs_info);
+
 /*
  * helper functions to cast a node into its container
  */
diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index 9814347..4889082 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -9,6 +9,7 @@
 #include <linux/blkdev.h>
 #include <linux/kthread.h>
 #include <linux/math64.h>
+#include "misc.h"
 #include "ctree.h"
 #include "extent_map.h"
 #include "disk-io.h"
@@ -56,10 +57,9 @@
 no_valid_dev_replace_entry_found:
 		ret = 0;
 		dev_replace->replace_state =
-			BTRFS_DEV_REPLACE_ITEM_STATE_NEVER_STARTED;
+			BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED;
 		dev_replace->cont_reading_from_srcdev_mode =
 		    BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS;
-		dev_replace->replace_state = 0;
 		dev_replace->time_started = 0;
 		dev_replace->time_stopped = 0;
 		atomic64_set(&dev_replace->num_write_errors, 0);
@@ -112,11 +112,11 @@
 		break;
 	case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
 	case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
-		dev_replace->srcdev = btrfs_find_device(fs_info, src_devid,
-							NULL, NULL);
-		dev_replace->tgtdev = btrfs_find_device(fs_info,
+		dev_replace->srcdev = btrfs_find_device(fs_info->fs_devices,
+						src_devid, NULL, NULL, true);
+		dev_replace->tgtdev = btrfs_find_device(fs_info->fs_devices,
 							BTRFS_DEV_REPLACE_DEVID,
-							NULL, NULL);
+							NULL, NULL, true);
 		/*
 		 * allow 'btrfs dev replace_cancel' if src/tgt device is
 		 * missing
@@ -202,7 +202,7 @@
 		return PTR_ERR(bdev);
 	}
 
-	filemap_write_and_wait(bdev->bd_inode->i_mapping);
+	sync_blockdev(bdev);
 
 	devices = &fs_info->fs_devices->devices;
 	list_for_each_entry(device, devices, dev_list) {
@@ -238,7 +238,6 @@
 	}
 	rcu_assign_pointer(device->name, name);
 
-	mutex_lock(&fs_info->fs_devices->device_list_mutex);
 	set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
 	device->generation = 0;
 	device->io_width = fs_info->sectorsize;
@@ -257,6 +256,8 @@
 	device->dev_stats_valid = 1;
 	set_blocksize(device->bdev, BTRFS_BDEV_BLOCKSIZE);
 	device->fs_devices = fs_info->fs_devices;
+
+	mutex_lock(&fs_info->fs_devices->device_list_mutex);
 	list_add(&device->dev_list, &fs_info->fs_devices->devices);
 	fs_info->fs_devices->num_devices++;
 	fs_info->fs_devices->open_devices++;
@@ -274,9 +275,9 @@
  * called from commit_transaction. Writes changed device replace state to
  * disk.
  */
-int btrfs_run_dev_replace(struct btrfs_trans_handle *trans,
-			  struct btrfs_fs_info *fs_info)
+int btrfs_run_dev_replace(struct btrfs_trans_handle *trans)
 {
+	struct btrfs_fs_info *fs_info = trans->fs_info;
 	int ret;
 	struct btrfs_root *dev_root = fs_info->dev_root;
 	struct btrfs_path *path;
@@ -285,13 +286,13 @@
 	struct btrfs_dev_replace_item *ptr;
 	struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
 
-	btrfs_dev_replace_read_lock(dev_replace);
+	down_read(&dev_replace->rwsem);
 	if (!dev_replace->is_valid ||
 	    !dev_replace->item_needs_writeback) {
-		btrfs_dev_replace_read_unlock(dev_replace);
+		up_read(&dev_replace->rwsem);
 		return 0;
 	}
-	btrfs_dev_replace_read_unlock(dev_replace);
+	up_read(&dev_replace->rwsem);
 
 	key.objectid = 0;
 	key.type = BTRFS_DEV_REPLACE_KEY;
@@ -349,7 +350,7 @@
 	ptr = btrfs_item_ptr(eb, path->slots[0],
 			     struct btrfs_dev_replace_item);
 
-	btrfs_dev_replace_write_lock(dev_replace);
+	down_write(&dev_replace->rwsem);
 	if (dev_replace->srcdev)
 		btrfs_set_dev_replace_src_devid(eb, ptr,
 			dev_replace->srcdev->devid);
@@ -372,7 +373,7 @@
 	btrfs_set_dev_replace_cursor_right(eb, ptr,
 		dev_replace->cursor_right);
 	dev_replace->item_needs_writeback = 0;
-	btrfs_dev_replace_write_unlock(dev_replace);
+	up_write(&dev_replace->rwsem);
 
 	btrfs_mark_buffer_dirty(eb);
 
@@ -382,14 +383,6 @@
 	return ret;
 }
 
-void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info)
-{
-	struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
-
-	dev_replace->committed_cursor_left =
-		dev_replace->cursor_left_last_write_of_item;
-}
-
 static char* btrfs_dev_name(struct btrfs_device *device)
 {
 	if (!device || test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state))
@@ -398,7 +391,7 @@
 		return rcu_str_deref(device->name);
 }
 
-int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info,
+static int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info,
 		const char *tgtdev_name, u64 srcdevid, const char *srcdev_name,
 		int read_src)
 {
@@ -409,15 +402,17 @@
 	struct btrfs_device *tgt_device = NULL;
 	struct btrfs_device *src_device = NULL;
 
-	ret = btrfs_find_device_by_devspec(fs_info, srcdevid,
-					    srcdev_name, &src_device);
-	if (ret)
-		return ret;
+	src_device = btrfs_find_device_by_devspec(fs_info, srcdevid,
+						  srcdev_name);
+	if (IS_ERR(src_device))
+		return PTR_ERR(src_device);
 
-	ret = btrfs_init_dev_replace_tgtdev(fs_info, tgtdev_name,
-					    src_device, &tgt_device);
-	if (ret)
-		return ret;
+	if (btrfs_pinned_by_swapfile(fs_info, src_device)) {
+		btrfs_warn_in_rcu(fs_info,
+	  "cannot replace device %s (devid %llu) due to active swapfile",
+			btrfs_dev_name(src_device), src_device->devid);
+		return -ETXTBSY;
+	}
 
 	/*
 	 * Here we commit the transaction to make sure commit_total_bytes
@@ -432,7 +427,12 @@
 		return PTR_ERR(trans);
 	}
 
-	btrfs_dev_replace_write_lock(dev_replace);
+	ret = btrfs_init_dev_replace_tgtdev(fs_info, tgtdev_name,
+					    src_device, &tgt_device);
+	if (ret)
+		return ret;
+
+	down_write(&dev_replace->rwsem);
 	switch (dev_replace->replace_state) {
 	case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
 	case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
@@ -442,11 +442,11 @@
 	case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
 		ASSERT(0);
 		ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED;
+		up_write(&dev_replace->rwsem);
 		goto leave;
 	}
 
 	dev_replace->cont_reading_from_srcdev_mode = read_src;
-	WARN_ON(!src_device);
 	dev_replace->srcdev = src_device;
 	dev_replace->tgtdev = tgt_device;
 
@@ -470,7 +470,7 @@
 	dev_replace->item_needs_writeback = 1;
 	atomic64_set(&dev_replace->num_write_errors, 0);
 	atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0);
-	btrfs_dev_replace_write_unlock(dev_replace);
+	up_write(&dev_replace->rwsem);
 
 	ret = btrfs_sysfs_add_device_link(tgt_device->fs_devices, tgt_device);
 	if (ret)
@@ -478,15 +478,16 @@
 
 	btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
 
-	/* force writing the updated state information to disk */
-	trans = btrfs_start_transaction(root, 0);
+	/* Commit dev_replace state and reserve 1 item for it. */
+	trans = btrfs_start_transaction(root, 1);
 	if (IS_ERR(trans)) {
 		ret = PTR_ERR(trans);
-		btrfs_dev_replace_write_lock(dev_replace);
+		down_write(&dev_replace->rwsem);
 		dev_replace->replace_state =
 			BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED;
 		dev_replace->srcdev = NULL;
 		dev_replace->tgtdev = NULL;
+		up_write(&dev_replace->rwsem);
 		goto leave;
 	}
 
@@ -501,14 +502,13 @@
 	ret = btrfs_dev_replace_finishing(fs_info, ret);
 	if (ret == -EINPROGRESS) {
 		ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS;
-	} else {
+	} else if (ret != -ECANCELED) {
 		WARN_ON(ret);
 	}
 
 	return ret;
 
 leave:
-	btrfs_dev_replace_write_unlock(dev_replace);
 	btrfs_destroy_dev_replace_tgtdev(tgt_device);
 	return ret;
 }
@@ -536,8 +536,9 @@
 					args->start.cont_reading_from_srcdev_mode);
 	args->result = ret;
 	/* don't warn if EINPROGRESS, someone else might be running scrub */
-	if (ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS)
-		ret = 0;
+	if (ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS ||
+	    ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR)
+		return 0;
 
 	return ret;
 }
@@ -548,8 +549,8 @@
 static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info)
 {
 	set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state);
-	wait_event(fs_info->replace_wait, !percpu_counter_sum(
-		   &fs_info->bio_counter));
+	wait_event(fs_info->dev_replace.replace_wait, !percpu_counter_sum(
+		   &fs_info->dev_replace.bio_counter));
 }
 
 /*
@@ -558,7 +559,7 @@
 static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info)
 {
 	clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state);
-	wake_up(&fs_info->replace_wait);
+	wake_up(&fs_info->dev_replace.replace_wait);
 }
 
 static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
@@ -575,18 +576,18 @@
 	/* don't allow cancel or unmount to disturb the finishing procedure */
 	mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
 
-	btrfs_dev_replace_read_lock(dev_replace);
+	down_read(&dev_replace->rwsem);
 	/* was the operation canceled, or is it finished? */
 	if (dev_replace->replace_state !=
 	    BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) {
-		btrfs_dev_replace_read_unlock(dev_replace);
+		up_read(&dev_replace->rwsem);
 		mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
 		return 0;
 	}
 
 	tgt_device = dev_replace->tgtdev;
 	src_device = dev_replace->srcdev;
-	btrfs_dev_replace_read_unlock(dev_replace);
+	up_read(&dev_replace->rwsem);
 
 	/*
 	 * flush all outstanding I/O and inode extent mappings before the
@@ -599,18 +600,34 @@
 	}
 	btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
 
-	trans = btrfs_start_transaction(root, 0);
-	if (IS_ERR(trans)) {
-		mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
-		return PTR_ERR(trans);
-	}
-	ret = btrfs_commit_transaction(trans);
-	WARN_ON(ret);
+	/*
+	 * We have to use this loop approach because at this point src_device
+	 * has to be available for transaction commit to complete, yet new
+	 * chunks shouldn't be allocated on the device.
+	 */
+	while (1) {
+		trans = btrfs_start_transaction(root, 0);
+		if (IS_ERR(trans)) {
+			mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
+			return PTR_ERR(trans);
+		}
+		ret = btrfs_commit_transaction(trans);
+		WARN_ON(ret);
 
-	/* keep away write_all_supers() during the finishing procedure */
-	mutex_lock(&fs_info->fs_devices->device_list_mutex);
-	mutex_lock(&fs_info->chunk_mutex);
-	btrfs_dev_replace_write_lock(dev_replace);
+		/* Prevent write_all_supers() during the finishing procedure */
+		mutex_lock(&fs_info->fs_devices->device_list_mutex);
+		/* Prevent new chunks being allocated on the source device */
+		mutex_lock(&fs_info->chunk_mutex);
+
+		if (!list_empty(&src_device->post_commit_list)) {
+			mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+			mutex_unlock(&fs_info->chunk_mutex);
+		} else {
+			break;
+		}
+	}
+
+	down_write(&dev_replace->rwsem);
 	dev_replace->replace_state =
 		scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED
 			  : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED;
@@ -625,12 +642,13 @@
 								src_device,
 								tgt_device);
 	} else {
-		btrfs_err_in_rcu(fs_info,
+		if (scrub_ret != -ECANCELED)
+			btrfs_err_in_rcu(fs_info,
 				 "btrfs_scrub_dev(%s, %llu, %s) failed %d",
 				 btrfs_dev_name(src_device),
 				 src_device->devid,
 				 rcu_str_deref(tgt_device->name), scrub_ret);
-		btrfs_dev_replace_write_unlock(dev_replace);
+		up_write(&dev_replace->rwsem);
 		mutex_unlock(&fs_info->chunk_mutex);
 		mutex_unlock(&fs_info->fs_devices->device_list_mutex);
 		btrfs_rm_dev_replace_blocked(fs_info);
@@ -657,8 +675,6 @@
 	btrfs_device_set_disk_total_bytes(tgt_device,
 					  src_device->disk_total_bytes);
 	btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used);
-	ASSERT(list_empty(&src_device->resized_list));
-	tgt_device->commit_total_bytes = src_device->commit_total_bytes;
 	tgt_device->commit_bytes_used = src_device->bytes_used;
 
 	btrfs_assign_next_active_device(src_device, tgt_device);
@@ -666,8 +682,7 @@
 	list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list);
 	fs_info->fs_devices->rw_devices++;
 
-	btrfs_dev_replace_write_unlock(dev_replace);
-
+	up_write(&dev_replace->rwsem);
 	btrfs_rm_dev_replace_blocked(fs_info);
 
 	btrfs_rm_dev_replace_remove_srcdev(src_device);
@@ -692,7 +707,7 @@
 
 	/* replace the sysfs entry */
 	btrfs_sysfs_rm_device_link(fs_info->fs_devices, src_device);
-	btrfs_rm_dev_replace_free_srcdev(fs_info, src_device);
+	btrfs_rm_dev_replace_free_srcdev(src_device);
 
 	/* write back the superblocks */
 	trans = btrfs_start_transaction(root, 0);
@@ -709,7 +724,7 @@
 						struct btrfs_device *srcdev,
 						struct btrfs_device *tgtdev)
 {
-	struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree;
+	struct extent_map_tree *em_tree = &fs_info->mapping_tree;
 	struct extent_map *em;
 	struct map_lookup *map;
 	u64 start = 0;
@@ -764,7 +779,7 @@
 {
 	struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
 
-	btrfs_dev_replace_read_lock(dev_replace);
+	down_read(&dev_replace->rwsem);
 	/* even if !dev_replace_is_valid, the values are good enough for
 	 * the replace_status ioctl */
 	args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
@@ -776,7 +791,7 @@
 	args->status.num_uncorrectable_read_errors =
 		atomic64_read(&dev_replace->num_uncorrectable_read_errors);
 	args->status.progress_1000 = btrfs_dev_replace_progress(fs_info);
-	btrfs_dev_replace_read_unlock(dev_replace);
+	up_read(&dev_replace->rwsem);
 }
 
 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info)
@@ -793,46 +808,75 @@
 		return -EROFS;
 
 	mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
-	btrfs_dev_replace_write_lock(dev_replace);
+	down_write(&dev_replace->rwsem);
 	switch (dev_replace->replace_state) {
 	case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
 	case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
 	case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
 		result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED;
-		btrfs_dev_replace_write_unlock(dev_replace);
-		goto leave;
+		up_write(&dev_replace->rwsem);
+		break;
 	case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
+		tgt_device = dev_replace->tgtdev;
+		src_device = dev_replace->srcdev;
+		up_write(&dev_replace->rwsem);
+		ret = btrfs_scrub_cancel(fs_info);
+		if (ret < 0) {
+			result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED;
+		} else {
+			result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
+			/*
+			 * btrfs_dev_replace_finishing() will handle the
+			 * cleanup part
+			 */
+			btrfs_info_in_rcu(fs_info,
+				"dev_replace from %s (devid %llu) to %s canceled",
+				btrfs_dev_name(src_device), src_device->devid,
+				btrfs_dev_name(tgt_device));
+		}
+		break;
 	case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
+		/*
+		 * Scrub doing the replace isn't running so we need to do the
+		 * cleanup step of btrfs_dev_replace_finishing() here
+		 */
 		result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
 		tgt_device = dev_replace->tgtdev;
 		src_device = dev_replace->srcdev;
 		dev_replace->tgtdev = NULL;
 		dev_replace->srcdev = NULL;
+		dev_replace->replace_state =
+				BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED;
+		dev_replace->time_stopped = ktime_get_real_seconds();
+		dev_replace->item_needs_writeback = 1;
+
+		up_write(&dev_replace->rwsem);
+
+		/* Scrub for replace must not be running in suspended state */
+		ret = btrfs_scrub_cancel(fs_info);
+		ASSERT(ret != -ENOTCONN);
+
+		trans = btrfs_start_transaction(root, 0);
+		if (IS_ERR(trans)) {
+			mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
+			return PTR_ERR(trans);
+		}
+		ret = btrfs_commit_transaction(trans);
+		WARN_ON(ret);
+
+		btrfs_info_in_rcu(fs_info,
+		"suspended dev_replace from %s (devid %llu) to %s canceled",
+			btrfs_dev_name(src_device), src_device->devid,
+			btrfs_dev_name(tgt_device));
+
+		if (tgt_device)
+			btrfs_destroy_dev_replace_tgtdev(tgt_device);
 		break;
+	default:
+		up_write(&dev_replace->rwsem);
+		result = -EINVAL;
 	}
-	dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED;
-	dev_replace->time_stopped = ktime_get_real_seconds();
-	dev_replace->item_needs_writeback = 1;
-	btrfs_dev_replace_write_unlock(dev_replace);
-	btrfs_scrub_cancel(fs_info);
 
-	trans = btrfs_start_transaction(root, 0);
-	if (IS_ERR(trans)) {
-		mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
-		return PTR_ERR(trans);
-	}
-	ret = btrfs_commit_transaction(trans);
-	WARN_ON(ret);
-
-	btrfs_info_in_rcu(fs_info,
-		"dev_replace from %s (devid %llu) to %s canceled",
-		btrfs_dev_name(src_device), src_device->devid,
-		btrfs_dev_name(tgt_device));
-
-	if (tgt_device)
-		btrfs_destroy_dev_replace_tgtdev(tgt_device);
-
-leave:
 	mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
 	return result;
 }
@@ -842,7 +886,8 @@
 	struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
 
 	mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
-	btrfs_dev_replace_write_lock(dev_replace);
+	down_write(&dev_replace->rwsem);
+
 	switch (dev_replace->replace_state) {
 	case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
 	case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
@@ -858,7 +903,7 @@
 		break;
 	}
 
-	btrfs_dev_replace_write_unlock(dev_replace);
+	up_write(&dev_replace->rwsem);
 	mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
 }
 
@@ -868,12 +913,13 @@
 	struct task_struct *task;
 	struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
 
-	btrfs_dev_replace_write_lock(dev_replace);
+	down_write(&dev_replace->rwsem);
+
 	switch (dev_replace->replace_state) {
 	case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
 	case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
 	case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
-		btrfs_dev_replace_write_unlock(dev_replace);
+		up_write(&dev_replace->rwsem);
 		return 0;
 	case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
 		break;
@@ -887,10 +933,12 @@
 			   "cannot continue dev_replace, tgtdev is missing");
 		btrfs_info(fs_info,
 			   "you may cancel the operation after 'mount -o degraded'");
-		btrfs_dev_replace_write_unlock(dev_replace);
+		dev_replace->replace_state =
+					BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED;
+		up_write(&dev_replace->rwsem);
 		return 0;
 	}
-	btrfs_dev_replace_write_unlock(dev_replace);
+	up_write(&dev_replace->rwsem);
 
 	/*
 	 * This could collide with a paused balance, but the exclusive op logic
@@ -898,6 +946,10 @@
 	 * dev-replace to start anyway.
 	 */
 	if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
+		down_write(&dev_replace->rwsem);
+		dev_replace->replace_state =
+					BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED;
+		up_write(&dev_replace->rwsem);
 		btrfs_info(fs_info,
 		"cannot resume dev-replace, other exclusive operation running");
 		return 0;
@@ -928,7 +980,7 @@
 			      btrfs_device_get_total_bytes(dev_replace->srcdev),
 			      &dev_replace->scrub_progress, 0, 1);
 	ret = btrfs_dev_replace_finishing(fs_info, ret);
-	WARN_ON(ret);
+	WARN_ON(ret && ret != -ECANCELED);
 
 	clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
 	return 0;
@@ -951,7 +1003,7 @@
 		 * something that can happen if the dev_replace
 		 * procedure is suspended by an umount and then
 		 * the tgtdev is missing (or "btrfs dev scan") was
-		 * not called and the the filesystem is remounted
+		 * not called and the filesystem is remounted
 		 * in degraded state. This does not stop the
 		 * dev_replace procedure. It needs to be canceled
 		 * manually if the cancellation is wanted.
@@ -961,81 +1013,27 @@
 	return 1;
 }
 
-void btrfs_dev_replace_read_lock(struct btrfs_dev_replace *dev_replace)
-{
-	read_lock(&dev_replace->lock);
-	atomic_inc(&dev_replace->read_locks);
-}
-
-void btrfs_dev_replace_read_unlock(struct btrfs_dev_replace *dev_replace)
-{
-	ASSERT(atomic_read(&dev_replace->read_locks) > 0);
-	atomic_dec(&dev_replace->read_locks);
-	read_unlock(&dev_replace->lock);
-}
-
-void btrfs_dev_replace_write_lock(struct btrfs_dev_replace *dev_replace)
-{
-again:
-	wait_event(dev_replace->read_lock_wq,
-		   atomic_read(&dev_replace->blocking_readers) == 0);
-	write_lock(&dev_replace->lock);
-	if (atomic_read(&dev_replace->blocking_readers)) {
-		write_unlock(&dev_replace->lock);
-		goto again;
-	}
-}
-
-void btrfs_dev_replace_write_unlock(struct btrfs_dev_replace *dev_replace)
-{
-	ASSERT(atomic_read(&dev_replace->blocking_readers) == 0);
-	write_unlock(&dev_replace->lock);
-}
-
-/* inc blocking cnt and release read lock */
-void btrfs_dev_replace_set_lock_blocking(
-					struct btrfs_dev_replace *dev_replace)
-{
-	/* only set blocking for read lock */
-	ASSERT(atomic_read(&dev_replace->read_locks) > 0);
-	atomic_inc(&dev_replace->blocking_readers);
-	read_unlock(&dev_replace->lock);
-}
-
-/* acquire read lock and dec blocking cnt */
-void btrfs_dev_replace_clear_lock_blocking(
-					struct btrfs_dev_replace *dev_replace)
-{
-	/* only set blocking for read lock */
-	ASSERT(atomic_read(&dev_replace->read_locks) > 0);
-	ASSERT(atomic_read(&dev_replace->blocking_readers) > 0);
-	read_lock(&dev_replace->lock);
-	/* Barrier implied by atomic_dec_and_test */
-	if (atomic_dec_and_test(&dev_replace->blocking_readers))
-		cond_wake_up_nomb(&dev_replace->read_lock_wq);
-}
-
 void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info)
 {
-	percpu_counter_inc(&fs_info->bio_counter);
+	percpu_counter_inc(&fs_info->dev_replace.bio_counter);
 }
 
 void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount)
 {
-	percpu_counter_sub(&fs_info->bio_counter, amount);
-	cond_wake_up_nomb(&fs_info->replace_wait);
+	percpu_counter_sub(&fs_info->dev_replace.bio_counter, amount);
+	cond_wake_up_nomb(&fs_info->dev_replace.replace_wait);
 }
 
 void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info)
 {
 	while (1) {
-		percpu_counter_inc(&fs_info->bio_counter);
+		percpu_counter_inc(&fs_info->dev_replace.bio_counter);
 		if (likely(!test_bit(BTRFS_FS_STATE_DEV_REPLACING,
 				     &fs_info->fs_state)))
 			break;
 
 		btrfs_bio_counter_dec(fs_info);
-		wait_event(fs_info->replace_wait,
+		wait_event(fs_info->dev_replace.replace_wait,
 			   !test_bit(BTRFS_FS_STATE_DEV_REPLACING,
 				     &fs_info->fs_state));
 	}
diff --git a/fs/btrfs/dev-replace.h b/fs/btrfs/dev-replace.h
index b6d4206..78c5d8f 100644
--- a/fs/btrfs/dev-replace.h
+++ b/fs/btrfs/dev-replace.h
@@ -9,31 +9,14 @@
 struct btrfs_ioctl_dev_replace_args;
 
 int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info);
-int btrfs_run_dev_replace(struct btrfs_trans_handle *trans,
-			  struct btrfs_fs_info *fs_info);
-void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info);
+int btrfs_run_dev_replace(struct btrfs_trans_handle *trans);
 int btrfs_dev_replace_by_ioctl(struct btrfs_fs_info *fs_info,
 			    struct btrfs_ioctl_dev_replace_args *args);
-int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info,
-		const char *tgtdev_name, u64 srcdevid, const char *srcdev_name,
-		int read_src);
 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info,
 			      struct btrfs_ioctl_dev_replace_args *args);
 int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info);
 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info);
 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info);
 int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace);
-void btrfs_dev_replace_read_lock(struct btrfs_dev_replace *dev_replace);
-void btrfs_dev_replace_read_unlock(struct btrfs_dev_replace *dev_replace);
-void btrfs_dev_replace_write_lock(struct btrfs_dev_replace *dev_replace);
-void btrfs_dev_replace_write_unlock(struct btrfs_dev_replace *dev_replace);
-void btrfs_dev_replace_set_lock_blocking(struct btrfs_dev_replace *dev_replace);
-void btrfs_dev_replace_clear_lock_blocking(
-					struct btrfs_dev_replace *dev_replace);
-
-static inline void btrfs_dev_replace_stats_inc(atomic64_t *stat_value)
-{
-	atomic64_inc(stat_value);
-}
 
 #endif
diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
index a678b07..863367c 100644
--- a/fs/btrfs/dir-item.c
+++ b/fs/btrfs/dir-item.c
@@ -36,7 +36,7 @@
 		di = btrfs_match_dir_item_name(fs_info, path, name, name_len);
 		if (di)
 			return ERR_PTR(-EEXIST);
-		btrfs_extend_item(fs_info, path, data_size);
+		btrfs_extend_item(path, data_size);
 	} else if (ret < 0)
 		return ERR_PTR(ret);
 	WARN_ON(ret > 0);
@@ -105,13 +105,13 @@
  * to use for the second index (if one is created).
  * Will return 0 or -ENOMEM
  */
-int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
-			  *root, const char *name, int name_len,
-			  struct btrfs_inode *dir, struct btrfs_key *location,
-			  u8 type, u64 index)
+int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, const char *name,
+			  int name_len, struct btrfs_inode *dir,
+			  struct btrfs_key *location, u8 type, u64 index)
 {
 	int ret = 0;
 	int ret2 = 0;
+	struct btrfs_root *root = dir->root;
 	struct btrfs_path *path;
 	struct btrfs_dir_item *dir_item;
 	struct extent_buffer *leaf;
@@ -429,8 +429,7 @@
 		start = btrfs_item_ptr_offset(leaf, path->slots[0]);
 		memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
 			item_len - (ptr + sub_item_len - start));
-		btrfs_truncate_item(root->fs_info, path,
-				    item_len - sub_item_len, 1);
+		btrfs_truncate_item(path, item_len - sub_item_len, 1);
 	}
 	return ret;
 }
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index d4a7f7c..402b61b 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -17,7 +17,9 @@
 #include <linux/semaphore.h>
 #include <linux/error-injection.h>
 #include <linux/crc32c.h>
+#include <linux/sched/mm.h>
 #include <asm/unaligned.h>
+#include <crypto/hash.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -38,10 +40,7 @@
 #include "compression.h"
 #include "tree-checker.h"
 #include "ref-verify.h"
-
-#ifdef CONFIG_X86
-#include <asm/cpufeature.h>
-#endif
+#include "block-group.h"
 
 #define BTRFS_SUPER_FLAG_SUPP	(BTRFS_HEADER_FLAG_WRITTEN |\
 				 BTRFS_HEADER_FLAG_RELOC |\
@@ -125,8 +124,8 @@
  * Different roots are used for different purposes and may nest inside each
  * other and they require separate keysets.  As lockdep keys should be
  * static, assign keysets according to the purpose of the root as indicated
- * by btrfs_root->objectid.  This ensures that all special purpose roots
- * have separate keysets.
+ * by btrfs_root->root_key.objectid.  This ensures that all special purpose
+ * roots have separate keysets.
  *
  * Lock-nesting across peer nodes is always done with the immediate parent
  * node locked thus preventing deadlock.  As lockdep doesn't know this, use
@@ -248,26 +247,15 @@
 	return em;
 }
 
-u32 btrfs_csum_data(const char *data, u32 seed, size_t len)
-{
-	return crc32c(seed, data, len);
-}
-
-void btrfs_csum_final(u32 crc, u8 *result)
-{
-	put_unaligned_le32(~crc, result);
-}
-
 /*
- * compute the csum for a btree block, and either verify it or write it
- * into the csum field of the block.
+ * Compute the csum of a btree block and store the result to provided buffer.
+ *
+ * Returns error if the extent buffer cannot be mapped.
  */
-static int csum_tree_block(struct btrfs_fs_info *fs_info,
-			   struct extent_buffer *buf,
-			   int verify)
+static int csum_tree_block(struct extent_buffer *buf, u8 *result)
 {
-	u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
-	char result[BTRFS_CSUM_SIZE];
+	struct btrfs_fs_info *fs_info = buf->fs_info;
+	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
 	unsigned long len;
 	unsigned long cur_len;
 	unsigned long offset = BTRFS_CSUM_SIZE;
@@ -275,40 +263,31 @@
 	unsigned long map_start;
 	unsigned long map_len;
 	int err;
-	u32 crc = ~(u32)0;
+
+	shash->tfm = fs_info->csum_shash;
+	crypto_shash_init(shash);
 
 	len = buf->len - offset;
+
 	while (len > 0) {
+		/*
+		 * Note: we don't need to check for the err == 1 case here, as
+		 * with the given combination of 'start = BTRFS_CSUM_SIZE (32)'
+		 * and 'min_len = 32' and the currently implemented mapping
+		 * algorithm we cannot cross a page boundary.
+		 */
 		err = map_private_extent_buffer(buf, offset, 32,
 					&kaddr, &map_start, &map_len);
-		if (err)
+		if (WARN_ON(err))
 			return err;
 		cur_len = min(len, map_len - (offset - map_start));
-		crc = btrfs_csum_data(kaddr + offset - map_start,
-				      crc, cur_len);
+		crypto_shash_update(shash, kaddr + offset - map_start, cur_len);
 		len -= cur_len;
 		offset += cur_len;
 	}
 	memset(result, 0, BTRFS_CSUM_SIZE);
 
-	btrfs_csum_final(crc, result);
-
-	if (verify) {
-		if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
-			u32 val;
-			u32 found = 0;
-			memcpy(&found, result, csum_size);
-
-			read_extent_buffer(buf, &val, 0, csum_size);
-			btrfs_warn_rl(fs_info,
-				"%s checksum verify failed on %llu wanted %X found %X level %d",
-				fs_info->sb->s_id, buf->start,
-				val, found, btrfs_header_level(buf));
-			return -EUCLEAN;
-		}
-	} else {
-		write_extent_buffer(buf, result, 0, csum_size);
-	}
+	crypto_shash_final(shash, result);
 
 	return 0;
 }
@@ -335,7 +314,7 @@
 
 	if (need_lock) {
 		btrfs_tree_read_lock(eb);
-		btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
+		btrfs_set_lock_blocking_read(eb);
 	}
 
 	lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
@@ -369,6 +348,16 @@
 	return ret;
 }
 
+static bool btrfs_supported_super_csum(u16 csum_type)
+{
+	switch (csum_type) {
+	case BTRFS_CSUM_TYPE_CRC32:
+		return true;
+	default:
+		return false;
+	}
+}
+
 /*
  * Return 0 if the superblock checksum type matches the checksum value of that
  * algorithm. Pass the raw disk superblock data.
@@ -378,51 +367,42 @@
 {
 	struct btrfs_super_block *disk_sb =
 		(struct btrfs_super_block *)raw_disk_sb;
-	u16 csum_type = btrfs_super_csum_type(disk_sb);
-	int ret = 0;
+	char result[BTRFS_CSUM_SIZE];
+	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
 
-	if (csum_type == BTRFS_CSUM_TYPE_CRC32) {
-		u32 crc = ~(u32)0;
-		char result[sizeof(crc)];
+	shash->tfm = fs_info->csum_shash;
+	crypto_shash_init(shash);
 
-		/*
-		 * The super_block structure does not span the whole
-		 * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space
-		 * is filled with zeros and is included in the checksum.
-		 */
-		crc = btrfs_csum_data(raw_disk_sb + BTRFS_CSUM_SIZE,
-				crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
-		btrfs_csum_final(crc, result);
+	/*
+	 * The super_block structure does not span the whole
+	 * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space is
+	 * filled with zeros and is included in the checksum.
+	 */
+	crypto_shash_update(shash, raw_disk_sb + BTRFS_CSUM_SIZE,
+			    BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
+	crypto_shash_final(shash, result);
 
-		if (memcmp(raw_disk_sb, result, sizeof(result)))
-			ret = 1;
-	}
+	if (memcmp(disk_sb->csum, result, btrfs_super_csum_size(disk_sb)))
+		return 1;
 
-	if (csum_type >= ARRAY_SIZE(btrfs_csum_sizes)) {
-		btrfs_err(fs_info, "unsupported checksum algorithm %u",
-				csum_type);
-		ret = 1;
-	}
-
-	return ret;
+	return 0;
 }
 
-static int verify_level_key(struct btrfs_fs_info *fs_info,
-			    struct extent_buffer *eb, int level,
-			    struct btrfs_key *first_key, u64 parent_transid)
+int btrfs_verify_level_key(struct extent_buffer *eb, int level,
+			   struct btrfs_key *first_key, u64 parent_transid)
 {
+	struct btrfs_fs_info *fs_info = eb->fs_info;
 	int found_level;
 	struct btrfs_key found_key;
 	int ret;
 
 	found_level = btrfs_header_level(eb);
 	if (found_level != level) {
-#ifdef CONFIG_BTRFS_DEBUG
-		WARN_ON(1);
+		WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG),
+		     KERN_ERR "BTRFS: tree level check failed\n");
 		btrfs_err(fs_info,
 "tree level mismatch detected, bytenr=%llu level expected=%u has=%u",
 			  eb->start, level, found_level);
-#endif
 		return -EIO;
 	}
 
@@ -437,15 +417,25 @@
 	 */
 	if (btrfs_header_generation(eb) > fs_info->last_trans_committed)
 		return 0;
+
+	/* We have @first_key, so this @eb must have at least one item */
+	if (btrfs_header_nritems(eb) == 0) {
+		btrfs_err(fs_info,
+		"invalid tree nritems, bytenr=%llu nritems=0 expect >0",
+			  eb->start);
+		WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
+		return -EUCLEAN;
+	}
+
 	if (found_level)
 		btrfs_node_key_to_cpu(eb, &found_key, 0);
 	else
 		btrfs_item_key_to_cpu(eb, &found_key, 0);
 	ret = btrfs_comp_cpu_keys(first_key, &found_key);
 
-#ifdef CONFIG_BTRFS_DEBUG
 	if (ret) {
-		WARN_ON(1);
+		WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG),
+		     KERN_ERR "BTRFS: tree first key check failed\n");
 		btrfs_err(fs_info,
 "tree first key mismatch detected, bytenr=%llu parent_transid=%llu key expected=(%llu,%u,%llu) has=(%llu,%u,%llu)",
 			  eb->start, parent_transid, first_key->objectid,
@@ -453,7 +443,6 @@
 			  found_key.objectid, found_key.type,
 			  found_key.offset);
 	}
-#endif
 	return ret;
 }
 
@@ -465,11 +454,11 @@
  * @level:		expected level, mandatory check
  * @first_key:		expected key of first slot, skip check if NULL
  */
-static int btree_read_extent_buffer_pages(struct btrfs_fs_info *fs_info,
-					  struct extent_buffer *eb,
+static int btree_read_extent_buffer_pages(struct extent_buffer *eb,
 					  u64 parent_transid, int level,
 					  struct btrfs_key *first_key)
 {
+	struct btrfs_fs_info *fs_info = eb->fs_info;
 	struct extent_io_tree *io_tree;
 	int failed = 0;
 	int ret;
@@ -480,14 +469,13 @@
 	io_tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
 	while (1) {
 		clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
-		ret = read_extent_buffer_pages(io_tree, eb, WAIT_COMPLETE,
-					       mirror_num);
+		ret = read_extent_buffer_pages(eb, WAIT_COMPLETE, mirror_num);
 		if (!ret) {
 			if (verify_parent_transid(io_tree, eb,
 						   parent_transid, 0))
 				ret = -EIO;
-			else if (verify_level_key(fs_info, eb, level,
-						  first_key, parent_transid))
+			else if (btrfs_verify_level_key(eb, level,
+						first_key, parent_transid))
 				ret = -EUCLEAN;
 			else
 				break;
@@ -512,7 +500,7 @@
 	}
 
 	if (failed && !ret && failed_mirror)
-		repair_eb_io_failure(fs_info, eb, failed_mirror);
+		btrfs_repair_eb_io_failure(eb, failed_mirror);
 
 	return ret;
 }
@@ -526,7 +514,10 @@
 {
 	u64 start = page_offset(page);
 	u64 found_start;
+	u8 result[BTRFS_CSUM_SIZE];
+	u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
 	struct extent_buffer *eb;
+	int ret;
 
 	eb = (struct extent_buffer *)page->private;
 	if (page != eb->pages[0])
@@ -542,22 +533,51 @@
 	if (WARN_ON(!PageUptodate(page)))
 		return -EUCLEAN;
 
-	ASSERT(memcmp_extent_buffer(eb, fs_info->fsid,
+	ASSERT(memcmp_extent_buffer(eb, fs_info->fs_devices->metadata_uuid,
 			btrfs_header_fsid(), BTRFS_FSID_SIZE) == 0);
 
-	return csum_tree_block(fs_info, eb, 0);
+	if (csum_tree_block(eb, result))
+		return -EINVAL;
+
+	if (btrfs_header_level(eb))
+		ret = btrfs_check_node(eb);
+	else
+		ret = btrfs_check_leaf_full(eb);
+
+	if (ret < 0) {
+		btrfs_err(fs_info,
+		"block=%llu write time tree block corruption detected",
+			  eb->start);
+		return ret;
+	}
+	write_extent_buffer(eb, result, 0, csum_size);
+
+	return 0;
 }
 
-static int check_tree_block_fsid(struct btrfs_fs_info *fs_info,
-				 struct extent_buffer *eb)
+static int check_tree_block_fsid(struct extent_buffer *eb)
 {
+	struct btrfs_fs_info *fs_info = eb->fs_info;
 	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
 	u8 fsid[BTRFS_FSID_SIZE];
 	int ret = 1;
 
 	read_extent_buffer(eb, fsid, btrfs_header_fsid(), BTRFS_FSID_SIZE);
 	while (fs_devices) {
-		if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
+		u8 *metadata_uuid;
+
+		/*
+		 * Checking the incompat flag is only valid for the current
+		 * fs. For seed devices it's forbidden to have their uuid
+		 * changed so reading ->fsid in this case is fine
+		 */
+		if (fs_devices == fs_info->fs_devices &&
+		    btrfs_fs_incompat(fs_info, METADATA_UUID))
+			metadata_uuid = fs_devices->metadata_uuid;
+		else
+			metadata_uuid = fs_devices->fsid;
+
+		if (!memcmp(fsid, metadata_uuid, BTRFS_FSID_SIZE)) {
 			ret = 0;
 			break;
 		}
@@ -575,7 +595,9 @@
 	struct extent_buffer *eb;
 	struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 	struct btrfs_fs_info *fs_info = root->fs_info;
+	u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
 	int ret = 0;
+	u8 result[BTRFS_CSUM_SIZE];
 	int reads_done;
 
 	if (!page->private)
@@ -605,7 +627,7 @@
 		ret = -EIO;
 		goto err;
 	}
-	if (check_tree_block_fsid(fs_info, eb)) {
+	if (check_tree_block_fsid(eb)) {
 		btrfs_err_rl(fs_info, "bad fsid on block %llu",
 			     eb->start);
 		ret = -EIO;
@@ -622,25 +644,44 @@
 	btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb),
 				       eb, found_level);
 
-	ret = csum_tree_block(fs_info, eb, 1);
+	ret = csum_tree_block(eb, result);
 	if (ret)
 		goto err;
 
+	if (memcmp_extent_buffer(eb, result, 0, csum_size)) {
+		u32 val;
+		u32 found = 0;
+
+		memcpy(&found, result, csum_size);
+
+		read_extent_buffer(eb, &val, 0, csum_size);
+		btrfs_warn_rl(fs_info,
+		"%s checksum verify failed on %llu wanted %x found %x level %d",
+			      fs_info->sb->s_id, eb->start,
+			      val, found, btrfs_header_level(eb));
+		ret = -EUCLEAN;
+		goto err;
+	}
+
 	/*
 	 * If this is a leaf block and it is corrupt, set the corrupt bit so
 	 * that we don't try and read the other copies of this block, just
 	 * return -EIO.
 	 */
-	if (found_level == 0 && btrfs_check_leaf_full(fs_info, eb)) {
+	if (found_level == 0 && btrfs_check_leaf_full(eb)) {
 		set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
 		ret = -EIO;
 	}
 
-	if (found_level > 0 && btrfs_check_node(fs_info, eb))
+	if (found_level > 0 && btrfs_check_node(eb))
 		ret = -EIO;
 
 	if (!ret)
 		set_extent_buffer_uptodate(eb);
+	else
+		btrfs_err(fs_info,
+			  "block=%llu read time tree block corruption detected",
+			  eb->start);
 err:
 	if (reads_done &&
 	    test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
@@ -660,19 +701,6 @@
 	return ret;
 }
 
-static int btree_io_failed_hook(struct page *page, int failed_mirror)
-{
-	struct extent_buffer *eb;
-
-	eb = (struct extent_buffer *)page->private;
-	set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
-	eb->read_mirror = failed_mirror;
-	atomic_dec(&eb->io_pages);
-	if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
-		btree_readahead_hook(eb, -EIO);
-	return -EIO;	/* we fixed nothing */
-}
-
 static void end_workqueue_bio(struct bio *bio)
 {
 	struct btrfs_end_io_wq *end_io_wq = bio->bi_private;
@@ -751,11 +779,22 @@
 		async->status = ret;
 }
 
+/*
+ * In order to insert checksums into the metadata in large chunks, we wait
+ * until bio submission time.   All the pages in the bio are checksummed and
+ * sums are attached onto the ordered extent record.
+ *
+ * At IO completion time the csums attached on the ordered extent record are
+ * inserted into the tree.
+ */
 static void run_one_async_done(struct btrfs_work *work)
 {
 	struct async_submit_bio *async;
+	struct inode *inode;
+	blk_status_t ret;
 
 	async = container_of(work, struct  async_submit_bio, work);
+	inode = async->private_data;
 
 	/* If an error occurred we just want to clean up the bio and move on */
 	if (async->status) {
@@ -764,7 +803,12 @@
 		return;
 	}
 
-	btrfs_submit_bio_done(async->private_data, async->bio, async->mirror_num);
+	ret = btrfs_map_bio(btrfs_sb(inode->i_sb), async->bio,
+			async->mirror_num, 1);
+	if (ret) {
+		async->bio->bi_status = ret;
+		bio_endio(async->bio);
+	}
 }
 
 static void run_one_async_free(struct btrfs_work *work)
@@ -809,10 +853,11 @@
 {
 	struct bio_vec *bvec;
 	struct btrfs_root *root;
-	int i, ret = 0;
+	int ret = 0;
+	struct bvec_iter_all iter_all;
 
 	ASSERT(!bio_flagged(bio, BIO_CLONED));
-	bio_for_each_segment_all(bvec, bio, i) {
+	bio_for_each_segment_all(bvec, bio, iter_all) {
 		root = BTRFS_I(bvec->bv_page->mapping->host)->root;
 		ret = csum_dirty_buffer(root->fs_info, bvec->bv_page);
 		if (ret)
@@ -832,24 +877,22 @@
 	return btree_csum_one_bio(bio);
 }
 
-static int check_async_write(struct btrfs_inode *bi)
+static int check_async_write(struct btrfs_fs_info *fs_info,
+			     struct btrfs_inode *bi)
 {
 	if (atomic_read(&bi->sync_writers))
 		return 0;
-#ifdef CONFIG_X86
-	if (static_cpu_has(X86_FEATURE_XMM4_2))
+	if (test_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags))
 		return 0;
-#endif
 	return 1;
 }
 
-static blk_status_t btree_submit_bio_hook(void *private_data, struct bio *bio,
-					  int mirror_num, unsigned long bio_flags,
-					  u64 bio_offset)
+static blk_status_t btree_submit_bio_hook(struct inode *inode, struct bio *bio,
+					  int mirror_num,
+					  unsigned long bio_flags)
 {
-	struct inode *inode = private_data;
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
-	int async = check_async_write(BTRFS_I(inode));
+	int async = check_async_write(fs_info, BTRFS_I(inode));
 	blk_status_t ret;
 
 	if (bio_op(bio) != REQ_OP_WRITE) {
@@ -873,8 +916,7 @@
 		 * checksumming can happen in parallel across all CPUs
 		 */
 		ret = btrfs_wq_submit_bio(fs_info, bio, mirror_num, 0,
-					  bio_offset, private_data,
-					  btree_submit_bio_start);
+					  0, inode, btree_submit_bio_start);
 	}
 
 	if (ret)
@@ -993,46 +1035,17 @@
 void readahead_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr)
 {
 	struct extent_buffer *buf = NULL;
-	struct inode *btree_inode = fs_info->btree_inode;
-
-	buf = btrfs_find_create_tree_block(fs_info, bytenr);
-	if (IS_ERR(buf))
-		return;
-	read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
-				 buf, WAIT_NONE, 0);
-	free_extent_buffer(buf);
-}
-
-int reada_tree_block_flagged(struct btrfs_fs_info *fs_info, u64 bytenr,
-			 int mirror_num, struct extent_buffer **eb)
-{
-	struct extent_buffer *buf = NULL;
-	struct inode *btree_inode = fs_info->btree_inode;
-	struct extent_io_tree *io_tree = &BTRFS_I(btree_inode)->io_tree;
 	int ret;
 
 	buf = btrfs_find_create_tree_block(fs_info, bytenr);
 	if (IS_ERR(buf))
-		return 0;
+		return;
 
-	set_bit(EXTENT_BUFFER_READAHEAD, &buf->bflags);
-
-	ret = read_extent_buffer_pages(io_tree, buf, WAIT_PAGE_LOCK,
-				       mirror_num);
-	if (ret) {
+	ret = read_extent_buffer_pages(buf, WAIT_NONE, 0);
+	if (ret < 0)
+		free_extent_buffer_stale(buf);
+	else
 		free_extent_buffer(buf);
-		return ret;
-	}
-
-	if (test_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags)) {
-		free_extent_buffer(buf);
-		return -EIO;
-	} else if (extent_buffer_uptodate(buf)) {
-		*eb = buf;
-	} else {
-		free_extent_buffer(buf);
-	}
-	return 0;
 }
 
 struct extent_buffer *btrfs_find_create_tree_block(
@@ -1044,19 +1057,6 @@
 	return alloc_extent_buffer(fs_info, bytenr);
 }
 
-
-int btrfs_write_tree_block(struct extent_buffer *buf)
-{
-	return filemap_fdatawrite_range(buf->pages[0]->mapping, buf->start,
-					buf->start + buf->len - 1);
-}
-
-void btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
-{
-	filemap_fdatawait_range(buf->pages[0]->mapping,
-			        buf->start, buf->start + buf->len - 1);
-}
-
 /*
  * Read tree block at logical address @bytenr and do variant basic but critical
  * verification.
@@ -1076,19 +1076,19 @@
 	if (IS_ERR(buf))
 		return buf;
 
-	ret = btree_read_extent_buffer_pages(fs_info, buf, parent_transid,
+	ret = btree_read_extent_buffer_pages(buf, parent_transid,
 					     level, first_key);
 	if (ret) {
-		free_extent_buffer(buf);
+		free_extent_buffer_stale(buf);
 		return ERR_PTR(ret);
 	}
 	return buf;
 
 }
 
-void clean_tree_block(struct btrfs_fs_info *fs_info,
-		      struct extent_buffer *buf)
+void btrfs_clean_tree_block(struct extent_buffer *buf)
 {
+	struct btrfs_fs_info *fs_info = buf->fs_info;
 	if (btrfs_header_generation(buf) ==
 	    fs_info->running_transaction->transid) {
 		btrfs_assert_tree_locked(buf);
@@ -1098,7 +1098,7 @@
 						 -buf->len,
 						 fs_info->dirty_metadata_batch);
 			/* ugh, clear_extent_buffer_dirty needs to lock the page */
-			btrfs_set_lock_blocking(buf);
+			btrfs_set_lock_blocking_write(buf);
 			clear_extent_buffer_dirty(buf);
 		}
 	}
@@ -1139,7 +1139,6 @@
 	root->state = 0;
 	root->orphan_cleanup_state = 0;
 
-	root->objectid = objectid;
 	root->last_trans = 0;
 	root->highest_objectid = 0;
 	root->nr_delalloc_inodes = 0;
@@ -1154,6 +1153,7 @@
 	INIT_LIST_HEAD(&root->delalloc_root);
 	INIT_LIST_HEAD(&root->ordered_extents);
 	INIT_LIST_HEAD(&root->ordered_root);
+	INIT_LIST_HEAD(&root->reloc_dirty_list);
 	INIT_LIST_HEAD(&root->logged_list[0]);
 	INIT_LIST_HEAD(&root->logged_list[1]);
 	spin_lock_init(&root->inode_lock);
@@ -1179,11 +1179,13 @@
 	refcount_set(&root->refs, 1);
 	atomic_set(&root->will_be_snapshotted, 0);
 	atomic_set(&root->snapshot_force_cow, 0);
+	atomic_set(&root->nr_swapfiles, 0);
 	root->log_transid = 0;
 	root->log_transid_committed = -1;
 	root->last_log_commit = 0;
 	if (!dummy)
-		extent_io_tree_init(&root->dirty_log_pages, NULL);
+		extent_io_tree_init(fs_info, &root->dirty_log_pages,
+				    IO_TREE_ROOT_DIRTY_LOG_PAGES, NULL);
 
 	memset(&root->root_key, 0, sizeof(root->root_key));
 	memset(&root->root_item, 0, sizeof(root->root_item));
@@ -1196,6 +1198,7 @@
 	root->anon_dev = 0;
 
 	spin_lock_init(&root->root_item_lock);
+	btrfs_qgroup_init_swapped_blocks(&root->swapped_blocks);
 }
 
 static struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info,
@@ -1229,17 +1232,24 @@
 #endif
 
 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
-				     struct btrfs_fs_info *fs_info,
 				     u64 objectid)
 {
+	struct btrfs_fs_info *fs_info = trans->fs_info;
 	struct extent_buffer *leaf;
 	struct btrfs_root *tree_root = fs_info->tree_root;
 	struct btrfs_root *root;
 	struct btrfs_key key;
+	unsigned int nofs_flag;
 	int ret = 0;
 	uuid_le uuid = NULL_UUID_LE;
 
+	/*
+	 * We're holding a transaction handle, so use a NOFS memory allocation
+	 * context to avoid deadlock if reclaim happens.
+	 */
+	nofs_flag = memalloc_nofs_save();
 	root = btrfs_alloc_root(fs_info, GFP_KERNEL);
+	memalloc_nofs_restore(nofs_flag);
 	if (!root)
 		return ERR_PTR(-ENOMEM);
 
@@ -1660,6 +1670,8 @@
 	while (1) {
 		again = 0;
 
+		set_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags);
+
 		/* Make the cleaner go to sleep early. */
 		if (btrfs_need_cleaner_sleep(fs_info))
 			goto sleep;
@@ -1683,9 +1695,7 @@
 			goto sleep;
 		}
 
-		mutex_lock(&fs_info->cleaner_delayed_iput_mutex);
 		btrfs_run_delayed_iputs(fs_info);
-		mutex_unlock(&fs_info->cleaner_delayed_iput_mutex);
 
 		again = btrfs_clean_one_deleted_snapshot(root);
 		mutex_unlock(&fs_info->cleaner_mutex);
@@ -1706,6 +1716,7 @@
 		 */
 		btrfs_delete_unused_bgs(fs_info);
 sleep:
+		clear_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags);
 		if (kthread_should_park())
 			kthread_parkme();
 		if (kthread_should_stop())
@@ -1997,7 +2008,6 @@
 	btrfs_destroy_workqueue(fs_info->readahead_workers);
 	btrfs_destroy_workqueue(fs_info->flush_workers);
 	btrfs_destroy_workqueue(fs_info->qgroup_rescan_workers);
-	btrfs_destroy_workqueue(fs_info->extent_workers);
 	/*
 	 * Now that all other work queues are destroyed, we can safely destroy
 	 * the queues used for metadata I/O, since tasks from those other work
@@ -2076,7 +2086,7 @@
 	atomic_set(&fs_info->scrubs_paused, 0);
 	atomic_set(&fs_info->scrub_cancel_req, 0);
 	init_waitqueue_head(&fs_info->scrub_pause_wait);
-	fs_info->scrub_workers_refcnt = 0;
+	refcount_set(&fs_info->scrub_workers_refcnt, 0);
 }
 
 static void btrfs_init_balance(struct btrfs_fs_info *fs_info)
@@ -2104,8 +2114,9 @@
 	inode->i_mapping->a_ops = &btree_aops;
 
 	RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
-	extent_io_tree_init(&BTRFS_I(inode)->io_tree, inode);
-	BTRFS_I(inode)->io_tree.track_uptodate = 0;
+	extent_io_tree_init(fs_info, &BTRFS_I(inode)->io_tree,
+			    IO_TREE_INODE_IO, inode);
+	BTRFS_I(inode)->io_tree.track_uptodate = false;
 	extent_map_tree_init(&BTRFS_I(inode)->extent_tree);
 
 	BTRFS_I(inode)->io_tree.ops = &btree_extent_io_ops;
@@ -2119,11 +2130,8 @@
 static void btrfs_init_dev_replace_locks(struct btrfs_fs_info *fs_info)
 {
 	mutex_init(&fs_info->dev_replace.lock_finishing_cancel_unmount);
-	rwlock_init(&fs_info->dev_replace.lock);
-	atomic_set(&fs_info->dev_replace.read_locks, 0);
-	atomic_set(&fs_info->dev_replace.blocking_readers, 0);
-	init_waitqueue_head(&fs_info->replace_wait);
-	init_waitqueue_head(&fs_info->dev_replace.read_lock_wq);
+	init_rwsem(&fs_info->dev_replace.rwsem);
+	init_waitqueue_head(&fs_info->dev_replace.replace_wait);
 }
 
 static void btrfs_init_qgroup(struct btrfs_fs_info *fs_info)
@@ -2131,7 +2139,6 @@
 	spin_lock_init(&fs_info->qgroup_lock);
 	mutex_init(&fs_info->qgroup_ioctl_lock);
 	fs_info->qgroup_tree = RB_ROOT;
-	fs_info->qgroup_op_tree = RB_ROOT;
 	INIT_LIST_HEAD(&fs_info->dirty_qgroups);
 	fs_info->qgroup_seq = 1;
 	fs_info->qgroup_ulist = NULL;
@@ -2206,10 +2213,6 @@
 				      max_active, 2);
 	fs_info->qgroup_rescan_workers =
 		btrfs_alloc_workqueue(fs_info, "qgroup-rescan", flags, 1, 0);
-	fs_info->extent_workers =
-		btrfs_alloc_workqueue(fs_info, "extent-refs", flags,
-				      min_t(u64, fs_devices->num_devices,
-					    max_active), 8);
 
 	if (!(fs_info->workers && fs_info->delalloc_workers &&
 	      fs_info->submit_workers && fs_info->flush_workers &&
@@ -2220,7 +2223,6 @@
 	      fs_info->endio_freespace_worker && fs_info->rmw_workers &&
 	      fs_info->caching_workers && fs_info->readahead_workers &&
 	      fs_info->fixup_workers && fs_info->delayed_workers &&
-	      fs_info->extent_workers &&
 	      fs_info->qgroup_rescan_workers)) {
 		return -ENOMEM;
 	}
@@ -2228,6 +2230,29 @@
 	return 0;
 }
 
+static int btrfs_init_csum_hash(struct btrfs_fs_info *fs_info, u16 csum_type)
+{
+	struct crypto_shash *csum_shash;
+	const char *csum_name = btrfs_super_csum_name(csum_type);
+
+	csum_shash = crypto_alloc_shash(csum_name, 0, 0);
+
+	if (IS_ERR(csum_shash)) {
+		btrfs_err(fs_info, "error allocating %s hash for checksum",
+			  csum_name);
+		return PTR_ERR(csum_shash);
+	}
+
+	fs_info->csum_shash = csum_shash;
+
+	return 0;
+}
+
+static void btrfs_free_csum_hash(struct btrfs_fs_info *fs_info)
+{
+	crypto_free_shash(fs_info->csum_shash);
+}
+
 static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
 			    struct btrfs_fs_devices *fs_devices)
 {
@@ -2444,10 +2469,11 @@
 		ret = -EINVAL;
 	}
 
-	if (memcmp(fs_info->fsid, sb->dev_item.fsid, BTRFS_FSID_SIZE) != 0) {
+	if (memcmp(fs_info->fs_devices->metadata_uuid, sb->dev_item.fsid,
+		   BTRFS_FSID_SIZE) != 0) {
 		btrfs_err(fs_info,
-			   "dev_item UUID does not match fsid: %pU != %pU",
-			   fs_info->fsid, sb->dev_item.fsid);
+			"dev_item UUID does not match metadata fsid: %pU != %pU",
+			fs_info->fs_devices->metadata_uuid, sb->dev_item.fsid);
 		ret = -EINVAL;
 	}
 
@@ -2542,7 +2568,7 @@
 	ret = validate_super(fs_info, sb, -1);
 	if (ret < 0)
 		goto out;
-	if (btrfs_super_csum_type(sb) != BTRFS_CSUM_TYPE_CRC32) {
+	if (!btrfs_supported_super_csum(btrfs_super_csum_type(sb))) {
 		ret = -EUCLEAN;
 		btrfs_err(fs_info, "invalid csum type, has %u want %u",
 			  btrfs_super_csum_type(sb), BTRFS_CSUM_TYPE_CRC32);
@@ -2572,6 +2598,7 @@
 	u32 stripesize;
 	u64 generation;
 	u64 features;
+	u16 csum_type;
 	struct btrfs_key location;
 	struct buffer_head *bh;
 	struct btrfs_super_block *disk_super;
@@ -2598,11 +2625,17 @@
 		goto fail;
 	}
 
-	ret = percpu_counter_init(&fs_info->dirty_metadata_bytes, 0, GFP_KERNEL);
+	ret = percpu_counter_init(&fs_info->dio_bytes, 0, GFP_KERNEL);
 	if (ret) {
 		err = ret;
 		goto fail_srcu;
 	}
+
+	ret = percpu_counter_init(&fs_info->dirty_metadata_bytes, 0, GFP_KERNEL);
+	if (ret) {
+		err = ret;
+		goto fail_dio_bytes;
+	}
 	fs_info->dirty_metadata_batch = PAGE_SIZE *
 					(1 + ilog2(nr_cpu_ids));
 
@@ -2612,7 +2645,8 @@
 		goto fail_dirty_metadata_bytes;
 	}
 
-	ret = percpu_counter_init(&fs_info->bio_counter, 0, GFP_KERNEL);
+	ret = percpu_counter_init(&fs_info->dev_replace.bio_counter, 0,
+			GFP_KERNEL);
 	if (ret) {
 		err = ret;
 		goto fail_delalloc_bytes;
@@ -2625,8 +2659,6 @@
 	INIT_LIST_HEAD(&fs_info->delayed_iputs);
 	INIT_LIST_HEAD(&fs_info->delalloc_roots);
 	INIT_LIST_HEAD(&fs_info->caching_block_groups);
-	INIT_LIST_HEAD(&fs_info->pending_raid_kobjs);
-	spin_lock_init(&fs_info->pending_raid_kobjs_lock);
 	spin_lock_init(&fs_info->delalloc_root_lock);
 	spin_lock_init(&fs_info->trans_lock);
 	spin_lock_init(&fs_info->fs_roots_radix_lock);
@@ -2634,7 +2666,6 @@
 	spin_lock_init(&fs_info->defrag_inodes_lock);
 	spin_lock_init(&fs_info->tree_mod_seq_lock);
 	spin_lock_init(&fs_info->super_lock);
-	spin_lock_init(&fs_info->qgroup_op_lock);
 	spin_lock_init(&fs_info->buffer_lock);
 	spin_lock_init(&fs_info->unused_bgs_lock);
 	rwlock_init(&fs_info->tree_mod_log_lock);
@@ -2642,14 +2673,13 @@
 	mutex_init(&fs_info->delete_unused_bgs_mutex);
 	mutex_init(&fs_info->reloc_mutex);
 	mutex_init(&fs_info->delalloc_root_mutex);
-	mutex_init(&fs_info->cleaner_delayed_iput_mutex);
 	seqlock_init(&fs_info->profiles_lock);
 
 	INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
 	INIT_LIST_HEAD(&fs_info->space_info);
 	INIT_LIST_HEAD(&fs_info->tree_mod_seq_list);
 	INIT_LIST_HEAD(&fs_info->unused_bgs);
-	btrfs_mapping_init(&fs_info->mapping_tree);
+	extent_map_tree_init(&fs_info->mapping_tree);
 	btrfs_init_block_rsv(&fs_info->global_block_rsv,
 			     BTRFS_BLOCK_RSV_GLOBAL);
 	btrfs_init_block_rsv(&fs_info->trans_block_rsv, BTRFS_BLOCK_RSV_TRANS);
@@ -2657,10 +2687,13 @@
 	btrfs_init_block_rsv(&fs_info->empty_block_rsv, BTRFS_BLOCK_RSV_EMPTY);
 	btrfs_init_block_rsv(&fs_info->delayed_block_rsv,
 			     BTRFS_BLOCK_RSV_DELOPS);
+	btrfs_init_block_rsv(&fs_info->delayed_refs_rsv,
+			     BTRFS_BLOCK_RSV_DELREFS);
+
 	atomic_set(&fs_info->async_delalloc_pages, 0);
 	atomic_set(&fs_info->defrag_running, 0);
-	atomic_set(&fs_info->qgroup_op_seq, 0);
 	atomic_set(&fs_info->reada_works_cnt, 0);
+	atomic_set(&fs_info->nr_delayed_iputs, 0);
 	atomic64_set(&fs_info->tree_mod_seq, 0);
 	fs_info->sb = sb;
 	fs_info->max_inline = BTRFS_DEFAULT_MAX_INLINE;
@@ -2712,8 +2745,10 @@
 	fs_info->block_group_cache_tree = RB_ROOT;
 	fs_info->first_logical_byte = (u64)-1;
 
-	extent_io_tree_init(&fs_info->freed_extents[0], NULL);
-	extent_io_tree_init(&fs_info->freed_extents[1], NULL);
+	extent_io_tree_init(fs_info, &fs_info->freed_extents[0],
+			    IO_TREE_FS_INFO_FREED_EXTENTS0, NULL);
+	extent_io_tree_init(fs_info, &fs_info->freed_extents[1],
+			    IO_TREE_FS_INFO_FREED_EXTENTS1, NULL);
 	fs_info->pinned_extents = &fs_info->freed_extents[0];
 	set_bit(BTRFS_FS_BARRIER, &fs_info->flags);
 
@@ -2738,14 +2773,18 @@
 	init_waitqueue_head(&fs_info->transaction_wait);
 	init_waitqueue_head(&fs_info->transaction_blocked_wait);
 	init_waitqueue_head(&fs_info->async_submit_wait);
-
-	INIT_LIST_HEAD(&fs_info->pinned_chunks);
+	init_waitqueue_head(&fs_info->delayed_iputs_wait);
 
 	/* Usable values until the real ones are cached from the superblock */
 	fs_info->nodesize = 4096;
 	fs_info->sectorsize = 4096;
 	fs_info->stripesize = 4096;
 
+	spin_lock_init(&fs_info->swapfile_pins_lock);
+	fs_info->swapfile_pins = RB_ROOT;
+
+	fs_info->send_in_progress = 0;
+
 	ret = btrfs_alloc_stripe_hash_table(fs_info);
 	if (ret) {
 		err = ret;
@@ -2766,6 +2805,25 @@
 	}
 
 	/*
+	 * Verify the type first, if that or the the checksum value are
+	 * corrupted, we'll find out
+	 */
+	csum_type = btrfs_super_csum_type((struct btrfs_super_block *)bh->b_data);
+	if (!btrfs_supported_super_csum(csum_type)) {
+		btrfs_err(fs_info, "unsupported checksum algorithm: %u",
+			  csum_type);
+		err = -EINVAL;
+		brelse(bh);
+		goto fail_alloc;
+	}
+
+	ret = btrfs_init_csum_hash(fs_info, csum_type);
+	if (ret) {
+		err = ret;
+		goto fail_alloc;
+	}
+
+	/*
 	 * We want to check superblock checksum, the type is stored inside.
 	 * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
 	 */
@@ -2773,7 +2831,7 @@
 		btrfs_err(fs_info, "superblock checksum mismatch");
 		err = -EINVAL;
 		brelse(bh);
-		goto fail_alloc;
+		goto fail_csum;
 	}
 
 	/*
@@ -2782,22 +2840,39 @@
 	 * the whole block of INFO_SIZE
 	 */
 	memcpy(fs_info->super_copy, bh->b_data, sizeof(*fs_info->super_copy));
-	memcpy(fs_info->super_for_commit, fs_info->super_copy,
-	       sizeof(*fs_info->super_for_commit));
 	brelse(bh);
 
-	memcpy(fs_info->fsid, fs_info->super_copy->fsid, BTRFS_FSID_SIZE);
+	disk_super = fs_info->super_copy;
+
+	ASSERT(!memcmp(fs_info->fs_devices->fsid, fs_info->super_copy->fsid,
+		       BTRFS_FSID_SIZE));
+
+	if (btrfs_fs_incompat(fs_info, METADATA_UUID)) {
+		ASSERT(!memcmp(fs_info->fs_devices->metadata_uuid,
+				fs_info->super_copy->metadata_uuid,
+				BTRFS_FSID_SIZE));
+	}
+
+	features = btrfs_super_flags(disk_super);
+	if (features & BTRFS_SUPER_FLAG_CHANGING_FSID_V2) {
+		features &= ~BTRFS_SUPER_FLAG_CHANGING_FSID_V2;
+		btrfs_set_super_flags(disk_super, features);
+		btrfs_info(fs_info,
+			"found metadata UUID change in progress flag, clearing");
+	}
+
+	memcpy(fs_info->super_for_commit, fs_info->super_copy,
+	       sizeof(*fs_info->super_for_commit));
 
 	ret = btrfs_validate_mount_super(fs_info);
 	if (ret) {
 		btrfs_err(fs_info, "superblock contains fatal errors");
 		err = -EINVAL;
-		goto fail_alloc;
+		goto fail_csum;
 	}
 
-	disk_super = fs_info->super_copy;
 	if (!btrfs_super_root(disk_super))
-		goto fail_alloc;
+		goto fail_csum;
 
 	/* check FS state, whether FS is broken. */
 	if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_ERROR)
@@ -2819,7 +2894,7 @@
 	ret = btrfs_parse_options(fs_info, options, sb->s_flags);
 	if (ret) {
 		err = ret;
-		goto fail_alloc;
+		goto fail_csum;
 	}
 
 	features = btrfs_super_incompat_flags(disk_super) &
@@ -2829,7 +2904,7 @@
 		    "cannot mount because of unsupported optional features (%llx)",
 		    features);
 		err = -EINVAL;
-		goto fail_alloc;
+		goto fail_csum;
 	}
 
 	features = btrfs_super_incompat_flags(disk_super);
@@ -2873,7 +2948,7 @@
 		btrfs_err(fs_info,
 "unequal nodesize/sectorsize (%u != %u) are not allowed for mixed block groups",
 			nodesize, sectorsize);
-		goto fail_alloc;
+		goto fail_csum;
 	}
 
 	/*
@@ -2889,7 +2964,7 @@
 	"cannot mount read-write because of unsupported optional features (%llx)",
 		       features);
 		err = -EINVAL;
-		goto fail_alloc;
+		goto fail_csum;
 	}
 
 	ret = btrfs_init_workqueues(fs_info, fs_devices);
@@ -2901,13 +2976,13 @@
 	sb->s_bdi->congested_fn = btrfs_congested_fn;
 	sb->s_bdi->congested_data = fs_info;
 	sb->s_bdi->capabilities |= BDI_CAP_CGROUP_WRITEBACK;
-	sb->s_bdi->ra_pages = VM_MAX_READAHEAD * SZ_1K / PAGE_SIZE;
+	sb->s_bdi->ra_pages = VM_READAHEAD_PAGES;
 	sb->s_bdi->ra_pages *= btrfs_super_num_devices(disk_super);
 	sb->s_bdi->ra_pages = max(sb->s_bdi->ra_pages, SZ_4M / PAGE_SIZE);
 
 	sb->s_blocksize = sectorsize;
 	sb->s_blocksize_bits = blksize_bits(sectorsize);
-	memcpy(&sb->s_uuid, fs_info->fsid, BTRFS_FSID_SIZE);
+	memcpy(&sb->s_uuid, fs_info->fs_devices->fsid, BTRFS_FSID_SIZE);
 
 	mutex_lock(&fs_info->chunk_mutex);
 	ret = btrfs_read_sys_array(fs_info);
@@ -3056,7 +3131,7 @@
 
 	if (!sb_rdonly(sb) && !btrfs_check_rw_degradable(fs_info, NULL)) {
 		btrfs_warn(fs_info,
-		"writeable mount is not allowed due to too many missing devices");
+		"writable mount is not allowed due to too many missing devices");
 		goto fail_sysfs;
 	}
 
@@ -3267,17 +3342,21 @@
 fail_sb_buffer:
 	btrfs_stop_all_workers(fs_info);
 	btrfs_free_block_groups(fs_info);
+fail_csum:
+	btrfs_free_csum_hash(fs_info);
 fail_alloc:
 fail_iput:
 	btrfs_mapping_tree_free(&fs_info->mapping_tree);
 
 	iput(fs_info->btree_inode);
 fail_bio_counter:
-	percpu_counter_destroy(&fs_info->bio_counter);
+	percpu_counter_destroy(&fs_info->dev_replace.bio_counter);
 fail_delalloc_bytes:
 	percpu_counter_destroy(&fs_info->delalloc_bytes);
 fail_dirty_metadata_bytes:
 	percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
+fail_dio_bytes:
+	percpu_counter_destroy(&fs_info->dio_bytes);
 fail_srcu:
 	cleanup_srcu_struct(&fs_info->subvol_srcu);
 fail:
@@ -3406,17 +3485,20 @@
 static int write_dev_supers(struct btrfs_device *device,
 			    struct btrfs_super_block *sb, int max_mirrors)
 {
+	struct btrfs_fs_info *fs_info = device->fs_info;
+	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
 	struct buffer_head *bh;
 	int i;
 	int ret;
 	int errors = 0;
-	u32 crc;
 	u64 bytenr;
 	int op_flags;
 
 	if (max_mirrors == 0)
 		max_mirrors = BTRFS_SUPER_MIRROR_MAX;
 
+	shash->tfm = fs_info->csum_shash;
+
 	for (i = 0; i < max_mirrors; i++) {
 		bytenr = btrfs_sb_offset(i);
 		if (bytenr + BTRFS_SUPER_INFO_SIZE >=
@@ -3425,10 +3507,10 @@
 
 		btrfs_set_super_bytenr(sb, bytenr);
 
-		crc = ~(u32)0;
-		crc = btrfs_csum_data((const char *)sb + BTRFS_CSUM_SIZE, crc,
-				      BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
-		btrfs_csum_final(crc, sb->csum);
+		crypto_shash_init(shash);
+		crypto_shash_update(shash, (const char *)sb + BTRFS_CSUM_SIZE,
+				    BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
+		crypto_shash_final(shash, sb->csum);
 
 		/* One reference for us, and we leave it for the caller */
 		bh = __getblk(device->bdev, bytenr / BTRFS_BDEV_BLOCKSIZE,
@@ -3643,7 +3725,7 @@
 
 	if ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 ||
 	    (flags & BTRFS_AVAIL_ALLOC_BIT_SINGLE))
-		min_tolerated = min(min_tolerated,
+		min_tolerated = min_t(int, min_tolerated,
 				    btrfs_raid_array[BTRFS_RAID_SINGLE].
 				    tolerated_failures);
 
@@ -3652,7 +3734,7 @@
 			continue;
 		if (!(flags & btrfs_raid_array[raid_type].bg_flag))
 			continue;
-		min_tolerated = min(min_tolerated,
+		min_tolerated = min_t(int, min_tolerated,
 				    btrfs_raid_array[raid_type].
 				    tolerated_failures);
 	}
@@ -3725,7 +3807,8 @@
 		btrfs_set_stack_device_io_width(dev_item, dev->io_width);
 		btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
 		memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
-		memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_FSID_SIZE);
+		memcpy(dev_item->fsid, dev->fs_devices->metadata_uuid,
+		       BTRFS_FSID_SIZE);
 
 		flags = btrfs_super_flags(sb);
 		btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
@@ -3947,6 +4030,7 @@
 	kthread_stop(fs_info->transaction_kthread);
 	kthread_stop(fs_info->cleaner_kthread);
 
+	ASSERT(list_empty(&fs_info->delayed_iputs));
 	set_bit(BTRFS_FS_CLOSING_DONE, &fs_info->flags);
 
 	btrfs_free_qgroup_config(fs_info);
@@ -3957,6 +4041,10 @@
 		       percpu_counter_sum(&fs_info->delalloc_bytes));
 	}
 
+	if (percpu_counter_sum(&fs_info->dio_bytes))
+		btrfs_info(fs_info, "at unmount dio bytes count %lld",
+			   percpu_counter_sum(&fs_info->dio_bytes));
+
 	btrfs_sysfs_remove_mounted(fs_info);
 	btrfs_sysfs_remove_fsid(fs_info->fs_devices);
 
@@ -3983,25 +4071,18 @@
 		btrfsic_unmount(fs_info->fs_devices);
 #endif
 
-	btrfs_close_devices(fs_info->fs_devices);
 	btrfs_mapping_tree_free(&fs_info->mapping_tree);
+	btrfs_close_devices(fs_info->fs_devices);
 
 	percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
 	percpu_counter_destroy(&fs_info->delalloc_bytes);
-	percpu_counter_destroy(&fs_info->bio_counter);
+	percpu_counter_destroy(&fs_info->dio_bytes);
+	percpu_counter_destroy(&fs_info->dev_replace.bio_counter);
 	cleanup_srcu_struct(&fs_info->subvol_srcu);
 
+	btrfs_free_csum_hash(fs_info);
 	btrfs_free_stripe_hash_table(fs_info);
 	btrfs_free_ref_cache(fs_info);
-
-	while (!list_empty(&fs_info->pinned_chunks)) {
-		struct extent_map *em;
-
-		em = list_first_entry(&fs_info->pinned_chunks,
-				      struct extent_map, list);
-		list_del_init(&em->list);
-		free_extent_map(em);
-	}
 }
 
 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
@@ -4031,7 +4112,7 @@
 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 	/*
 	 * This is a fast path so only do this check if we have sanity tests
-	 * enabled.  Normal people shouldn't be using umapped buffers as dirty
+	 * enabled.  Normal people shouldn't be using unmapped buffers as dirty
 	 * outside of the sanity tests.
 	 */
 	if (unlikely(test_bit(EXTENT_BUFFER_UNMAPPED, &buf->bflags)))
@@ -4055,7 +4136,7 @@
 	 * So here we should only check item pointers, not item data.
 	 */
 	if (btrfs_header_level(buf) == 0 &&
-	    btrfs_check_leaf_relaxed(fs_info, buf)) {
+	    btrfs_check_leaf_relaxed(buf)) {
 		btrfs_print_leaf(buf);
 		ASSERT(0);
 	}
@@ -4098,10 +4179,7 @@
 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid, int level,
 		      struct btrfs_key *first_key)
 {
-	struct btrfs_root *root = BTRFS_I(buf->pages[0]->mapping->host)->root;
-	struct btrfs_fs_info *fs_info = root->fs_info;
-
-	return btree_read_extent_buffer_pages(fs_info, buf, parent_transid,
+	return btree_read_extent_buffer_pages(buf, parent_transid,
 					      level, first_key);
 }
 
@@ -4155,6 +4233,14 @@
 		spin_lock(&fs_info->ordered_root_lock);
 	}
 	spin_unlock(&fs_info->ordered_root_lock);
+
+	/*
+	 * We need this here because if we've been flipped read-only we won't
+	 * get sync() from the umount, so we need to make sure any ordered
+	 * extents that haven't had their dirty pages IO start writeout yet
+	 * actually get run and error out properly.
+	 */
+	btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
 }
 
 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
@@ -4174,29 +4260,22 @@
 		return ret;
 	}
 
-	while ((node = rb_first(&delayed_refs->href_root)) != NULL) {
+	while ((node = rb_first_cached(&delayed_refs->href_root)) != NULL) {
 		struct btrfs_delayed_ref_head *head;
 		struct rb_node *n;
 		bool pin_bytes = false;
 
 		head = rb_entry(node, struct btrfs_delayed_ref_head,
 				href_node);
-		if (!mutex_trylock(&head->mutex)) {
-			refcount_inc(&head->refs);
-			spin_unlock(&delayed_refs->lock);
-
-			mutex_lock(&head->mutex);
-			mutex_unlock(&head->mutex);
-			btrfs_put_delayed_ref_head(head);
-			spin_lock(&delayed_refs->lock);
+		if (btrfs_delayed_ref_lock(delayed_refs, head))
 			continue;
-		}
+
 		spin_lock(&head->lock);
-		while ((n = rb_first(&head->ref_tree)) != NULL) {
+		while ((n = rb_first_cached(&head->ref_tree)) != NULL) {
 			ref = rb_entry(n, struct btrfs_delayed_ref_node,
 				       ref_node);
 			ref->in_tree = 0;
-			rb_erase(&ref->ref_node, &head->ref_tree);
+			rb_erase_cached(&ref->ref_node, &head->ref_tree);
 			RB_CLEAR_NODE(&ref->ref_node);
 			if (!list_empty(&ref->add_list))
 				list_del(&ref->add_list);
@@ -4206,12 +4285,7 @@
 		if (head->must_insert_reserved)
 			pin_bytes = true;
 		btrfs_free_delayed_extent_op(head->extent_op);
-		delayed_refs->num_heads--;
-		if (head->processing == 0)
-			delayed_refs->num_heads_ready--;
-		atomic_dec(&delayed_refs->num_entries);
-		rb_erase(&head->href_node, &delayed_refs->href_root);
-		RB_CLEAR_NODE(&head->href_node);
+		btrfs_delete_ref_head(delayed_refs, head);
 		spin_unlock(&head->lock);
 		spin_unlock(&delayed_refs->lock);
 		mutex_unlock(&head->mutex);
@@ -4219,6 +4293,7 @@
 		if (pin_bytes)
 			btrfs_pin_extent(fs_info, head->bytenr,
 					 head->num_bytes, 1);
+		btrfs_cleanup_ref_head_accounting(fs_info, delayed_refs, head);
 		btrfs_put_delayed_ref_head(head);
 		cond_resched();
 		spin_lock(&delayed_refs->lock);
@@ -4329,6 +4404,8 @@
 	unpin = pinned_extents;
 again:
 	while (1) {
+		struct extent_state *cached_state = NULL;
+
 		/*
 		 * The btrfs_finish_extent_commit() may get the same range as
 		 * ours between find_first_extent_bit and clear_extent_dirty.
@@ -4337,13 +4414,14 @@
 		 */
 		mutex_lock(&fs_info->unused_bg_unpin_mutex);
 		ret = find_first_extent_bit(unpin, 0, &start, &end,
-					    EXTENT_DIRTY, NULL);
+					    EXTENT_DIRTY, &cached_state);
 		if (ret) {
 			mutex_unlock(&fs_info->unused_bg_unpin_mutex);
 			break;
 		}
 
-		clear_extent_dirty(unpin, start, end);
+		clear_extent_dirty(unpin, start, end, &cached_state);
+		free_extent_state(cached_state);
 		btrfs_error_unpin_extent_range(fs_info, start, end);
 		mutex_unlock(&fs_info->unused_bg_unpin_mutex);
 		cond_resched();
@@ -4400,6 +4478,7 @@
 
 		spin_unlock(&cur_trans->dirty_bgs_lock);
 		btrfs_put_block_group(cache);
+		btrfs_delayed_refs_rsv_release(fs_info, 1);
 		spin_lock(&cur_trans->dirty_bgs_lock);
 	}
 	spin_unlock(&cur_trans->dirty_bgs_lock);
@@ -4424,10 +4503,17 @@
 void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans,
 				   struct btrfs_fs_info *fs_info)
 {
+	struct btrfs_device *dev, *tmp;
+
 	btrfs_cleanup_dirty_bgs(cur_trans, fs_info);
 	ASSERT(list_empty(&cur_trans->dirty_bgs));
 	ASSERT(list_empty(&cur_trans->io_bgs));
 
+	list_for_each_entry_safe(dev, tmp, &cur_trans->dev_update_list,
+				 post_commit_list) {
+		list_del_init(&dev->post_commit_list);
+	}
+
 	btrfs_destroy_delayed_refs(cur_trans, fs_info);
 
 	cur_trans->state = TRANS_STATE_COMMIT_START;
@@ -4505,7 +4591,4 @@
 	/* mandatory callbacks */
 	.submit_bio_hook = btree_submit_bio_hook,
 	.readpage_end_io_hook = btree_readpage_end_io_hook,
-	.readpage_io_failed_hook = btree_io_failed_hook,
-
-	/* optional callbacks */
 };
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index 4cccba2..a695810 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -21,11 +21,11 @@
 #define BTRFS_BDEV_BLOCKSIZE	(4096)
 
 enum btrfs_wq_endio_type {
-	BTRFS_WQ_ENDIO_DATA = 0,
-	BTRFS_WQ_ENDIO_METADATA = 1,
-	BTRFS_WQ_ENDIO_FREE_SPACE = 2,
-	BTRFS_WQ_ENDIO_RAID56 = 3,
-	BTRFS_WQ_ENDIO_DIO_REPAIR = 4,
+	BTRFS_WQ_ENDIO_DATA,
+	BTRFS_WQ_ENDIO_METADATA,
+	BTRFS_WQ_ENDIO_FREE_SPACE,
+	BTRFS_WQ_ENDIO_RAID56,
+	BTRFS_WQ_ENDIO_DIO_REPAIR,
 };
 
 static inline u64 btrfs_sb_offset(int mirror)
@@ -39,16 +39,16 @@
 struct btrfs_device;
 struct btrfs_fs_devices;
 
+int btrfs_verify_level_key(struct extent_buffer *eb, int level,
+			   struct btrfs_key *first_key, u64 parent_transid);
 struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
 				      u64 parent_transid, int level,
 				      struct btrfs_key *first_key);
 void readahead_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr);
-int reada_tree_block_flagged(struct btrfs_fs_info *fs_info, u64 bytenr,
-			 int mirror_num, struct extent_buffer **eb);
 struct extent_buffer *btrfs_find_create_tree_block(
 						struct btrfs_fs_info *fs_info,
 						u64 bytenr);
-void clean_tree_block(struct btrfs_fs_info *fs_info, struct extent_buffer *buf);
+void btrfs_clean_tree_block(struct extent_buffer *buf);
 int open_ctree(struct super_block *sb,
 	       struct btrfs_fs_devices *fs_devices,
 	       char *options);
@@ -113,8 +113,6 @@
 			  int atomic);
 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid, int level,
 		      struct btrfs_key *first_key);
-u32 btrfs_csum_data(const char *data, u32 seed, size_t len);
-void btrfs_csum_final(u32 crc, u8 *result);
 blk_status_t btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
 			enum btrfs_wq_endio_type metadata);
 blk_status_t btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
@@ -123,8 +121,6 @@
 			extent_submit_bio_start_t *submit_bio_start);
 blk_status_t btrfs_submit_bio_done(void *private_data, struct bio *bio,
 			  int mirror_num);
-int btrfs_write_tree_block(struct extent_buffer *buf);
-void btrfs_wait_tree_block_writeback(struct extent_buffer *buf);
 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
 			     struct btrfs_fs_info *fs_info);
 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
@@ -134,7 +130,6 @@
 void btrfs_cleanup_one_transaction(struct btrfs_transaction *trans,
 				  struct btrfs_fs_info *fs_info);
 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
-				     struct btrfs_fs_info *fs_info,
 				     u64 objectid);
 int btree_lock_page_hook(struct page *page, void *data,
 				void (*flush_fn)(void *));
diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c
index 1f3755b..ddf28ec 100644
--- a/fs/btrfs/export.c
+++ b/fs/btrfs/export.c
@@ -33,7 +33,7 @@
 	type = FILEID_BTRFS_WITHOUT_PARENT;
 
 	fid->objectid = btrfs_ino(BTRFS_I(inode));
-	fid->root_objectid = BTRFS_I(inode)->root->objectid;
+	fid->root_objectid = BTRFS_I(inode)->root->root_key.objectid;
 	fid->gen = inode->i_generation;
 
 	if (parent) {
@@ -41,7 +41,7 @@
 
 		fid->parent_objectid = BTRFS_I(parent)->location.objectid;
 		fid->parent_gen = parent->i_generation;
-		parent_root_id = BTRFS_I(parent)->root->objectid;
+		parent_root_id = BTRFS_I(parent)->root->root_key.objectid;
 
 		if (parent_root_id != fid->root_objectid) {
 			fid->parent_root_objectid = parent_root_id;
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 51e41e5..49cb26f 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -16,6 +16,7 @@
 #include <linux/percpu_counter.h>
 #include <linux/lockdep.h>
 #include <linux/crc32c.h>
+#include "misc.h"
 #include "tree-log.h"
 #include "disk-io.h"
 #include "print-tree.h"
@@ -24,32 +25,16 @@
 #include "locking.h"
 #include "free-space-cache.h"
 #include "free-space-tree.h"
-#include "math.h"
 #include "sysfs.h"
 #include "qgroup.h"
 #include "ref-verify.h"
+#include "space-info.h"
+#include "block-rsv.h"
+#include "delalloc-space.h"
+#include "block-group.h"
 
 #undef SCRAMBLE_DELAYED_REFS
 
-/*
- * control flags for do_chunk_alloc's force field
- * CHUNK_ALLOC_NO_FORCE means to only allocate a chunk
- * if we really need one.
- *
- * CHUNK_ALLOC_LIMITED means to only try and allocate one
- * if we have very few chunks already allocated.  This is
- * used as part of the clustering code to help make sure
- * we have a good pool of storage to cluster in, without
- * filling the FS with empty chunks
- *
- * CHUNK_ALLOC_FORCE means it must try to allocate one
- *
- */
-enum {
-	CHUNK_ALLOC_NO_FORCE = 0,
-	CHUNK_ALLOC_LIMITED = 1,
-	CHUNK_ALLOC_FORCE = 2,
-};
 
 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
 			       struct btrfs_delayed_ref_node *node, u64 parent,
@@ -66,148 +51,16 @@
 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
 				     struct btrfs_delayed_ref_node *node,
 				     struct btrfs_delayed_extent_op *extent_op);
-static int do_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags,
-			  int force);
 static int find_next_key(struct btrfs_path *path, int level,
 			 struct btrfs_key *key);
-static void dump_space_info(struct btrfs_fs_info *fs_info,
-			    struct btrfs_space_info *info, u64 bytes,
-			    int dump_block_groups);
-static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv,
-			       u64 num_bytes);
-static void space_info_add_new_bytes(struct btrfs_fs_info *fs_info,
-				     struct btrfs_space_info *space_info,
-				     u64 num_bytes);
-static void space_info_add_old_bytes(struct btrfs_fs_info *fs_info,
-				     struct btrfs_space_info *space_info,
-				     u64 num_bytes);
-
-static noinline int
-block_group_cache_done(struct btrfs_block_group_cache *cache)
-{
-	smp_mb();
-	return cache->cached == BTRFS_CACHE_FINISHED ||
-		cache->cached == BTRFS_CACHE_ERROR;
-}
 
 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
 {
 	return (cache->flags & bits) == bits;
 }
 
-void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
-{
-	atomic_inc(&cache->count);
-}
-
-void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
-{
-	if (atomic_dec_and_test(&cache->count)) {
-		WARN_ON(cache->pinned > 0);
-		WARN_ON(cache->reserved > 0);
-
-		/*
-		 * If not empty, someone is still holding mutex of
-		 * full_stripe_lock, which can only be released by caller.
-		 * And it will definitely cause use-after-free when caller
-		 * tries to release full stripe lock.
-		 *
-		 * No better way to resolve, but only to warn.
-		 */
-		WARN_ON(!RB_EMPTY_ROOT(&cache->full_stripe_locks_root.root));
-		kfree(cache->free_space_ctl);
-		kfree(cache);
-	}
-}
-
-/*
- * this adds the block group to the fs_info rb tree for the block group
- * cache
- */
-static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
-				struct btrfs_block_group_cache *block_group)
-{
-	struct rb_node **p;
-	struct rb_node *parent = NULL;
-	struct btrfs_block_group_cache *cache;
-
-	spin_lock(&info->block_group_cache_lock);
-	p = &info->block_group_cache_tree.rb_node;
-
-	while (*p) {
-		parent = *p;
-		cache = rb_entry(parent, struct btrfs_block_group_cache,
-				 cache_node);
-		if (block_group->key.objectid < cache->key.objectid) {
-			p = &(*p)->rb_left;
-		} else if (block_group->key.objectid > cache->key.objectid) {
-			p = &(*p)->rb_right;
-		} else {
-			spin_unlock(&info->block_group_cache_lock);
-			return -EEXIST;
-		}
-	}
-
-	rb_link_node(&block_group->cache_node, parent, p);
-	rb_insert_color(&block_group->cache_node,
-			&info->block_group_cache_tree);
-
-	if (info->first_logical_byte > block_group->key.objectid)
-		info->first_logical_byte = block_group->key.objectid;
-
-	spin_unlock(&info->block_group_cache_lock);
-
-	return 0;
-}
-
-/*
- * This will return the block group at or after bytenr if contains is 0, else
- * it will return the block group that contains the bytenr
- */
-static struct btrfs_block_group_cache *
-block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
-			      int contains)
-{
-	struct btrfs_block_group_cache *cache, *ret = NULL;
-	struct rb_node *n;
-	u64 end, start;
-
-	spin_lock(&info->block_group_cache_lock);
-	n = info->block_group_cache_tree.rb_node;
-
-	while (n) {
-		cache = rb_entry(n, struct btrfs_block_group_cache,
-				 cache_node);
-		end = cache->key.objectid + cache->key.offset - 1;
-		start = cache->key.objectid;
-
-		if (bytenr < start) {
-			if (!contains && (!ret || start < ret->key.objectid))
-				ret = cache;
-			n = n->rb_left;
-		} else if (bytenr > start) {
-			if (contains && bytenr <= end) {
-				ret = cache;
-				break;
-			}
-			n = n->rb_right;
-		} else {
-			ret = cache;
-			break;
-		}
-	}
-	if (ret) {
-		btrfs_get_block_group(ret);
-		if (bytenr == 0 && info->first_logical_byte > ret->key.objectid)
-			info->first_logical_byte = ret->key.objectid;
-	}
-	spin_unlock(&info->block_group_cache_lock);
-
-	return ret;
-}
-
-static int add_excluded_extent(struct btrfs_fs_info *fs_info,
-			       u64 start, u64 num_bytes)
+int btrfs_add_excluded_extent(struct btrfs_fs_info *fs_info,
+			      u64 start, u64 num_bytes)
 {
 	u64 end = start + num_bytes - 1;
 	set_extent_bits(&fs_info->freed_extents[0],
@@ -217,7 +70,7 @@
 	return 0;
 }
 
-static void free_excluded_extents(struct btrfs_block_group_cache *cache)
+void btrfs_free_excluded_extents(struct btrfs_block_group_cache *cache)
 {
 	struct btrfs_fs_info *fs_info = cache->fs_info;
 	u64 start, end;
@@ -231,547 +84,39 @@
 			  start, end, EXTENT_UPTODATE);
 }
 
-static int exclude_super_stripes(struct btrfs_block_group_cache *cache)
+static u64 generic_ref_to_space_flags(struct btrfs_ref *ref)
 {
-	struct btrfs_fs_info *fs_info = cache->fs_info;
-	u64 bytenr;
-	u64 *logical;
-	int stripe_len;
-	int i, nr, ret;
-
-	if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) {
-		stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid;
-		cache->bytes_super += stripe_len;
-		ret = add_excluded_extent(fs_info, cache->key.objectid,
-					  stripe_len);
-		if (ret)
-			return ret;
-	}
-
-	for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
-		bytenr = btrfs_sb_offset(i);
-		ret = btrfs_rmap_block(fs_info, cache->key.objectid,
-				       bytenr, &logical, &nr, &stripe_len);
-		if (ret)
-			return ret;
-
-		while (nr--) {
-			u64 start, len;
-
-			if (logical[nr] > cache->key.objectid +
-			    cache->key.offset)
-				continue;
-
-			if (logical[nr] + stripe_len <= cache->key.objectid)
-				continue;
-
-			start = logical[nr];
-			if (start < cache->key.objectid) {
-				start = cache->key.objectid;
-				len = (logical[nr] + stripe_len) - start;
-			} else {
-				len = min_t(u64, stripe_len,
-					    cache->key.objectid +
-					    cache->key.offset - start);
-			}
-
-			cache->bytes_super += len;
-			ret = add_excluded_extent(fs_info, start, len);
-			if (ret) {
-				kfree(logical);
-				return ret;
-			}
-		}
-
-		kfree(logical);
-	}
-	return 0;
-}
-
-static struct btrfs_caching_control *
-get_caching_control(struct btrfs_block_group_cache *cache)
-{
-	struct btrfs_caching_control *ctl;
-
-	spin_lock(&cache->lock);
-	if (!cache->caching_ctl) {
-		spin_unlock(&cache->lock);
-		return NULL;
-	}
-
-	ctl = cache->caching_ctl;
-	refcount_inc(&ctl->count);
-	spin_unlock(&cache->lock);
-	return ctl;
-}
-
-static void put_caching_control(struct btrfs_caching_control *ctl)
-{
-	if (refcount_dec_and_test(&ctl->count))
-		kfree(ctl);
-}
-
-#ifdef CONFIG_BTRFS_DEBUG
-static void fragment_free_space(struct btrfs_block_group_cache *block_group)
-{
-	struct btrfs_fs_info *fs_info = block_group->fs_info;
-	u64 start = block_group->key.objectid;
-	u64 len = block_group->key.offset;
-	u64 chunk = block_group->flags & BTRFS_BLOCK_GROUP_METADATA ?
-		fs_info->nodesize : fs_info->sectorsize;
-	u64 step = chunk << 1;
-
-	while (len > chunk) {
-		btrfs_remove_free_space(block_group, start, chunk);
-		start += step;
-		if (len < step)
-			len = 0;
+	if (ref->type == BTRFS_REF_METADATA) {
+		if (ref->tree_ref.root == BTRFS_CHUNK_TREE_OBJECTID)
+			return BTRFS_BLOCK_GROUP_SYSTEM;
 		else
-			len -= step;
+			return BTRFS_BLOCK_GROUP_METADATA;
 	}
-}
-#endif
-
-/*
- * this is only called by cache_block_group, since we could have freed extents
- * we need to check the pinned_extents for any extents that can't be used yet
- * since their free space will be released as soon as the transaction commits.
- */
-u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
-		       u64 start, u64 end)
-{
-	struct btrfs_fs_info *info = block_group->fs_info;
-	u64 extent_start, extent_end, size, total_added = 0;
-	int ret;
-
-	while (start < end) {
-		ret = find_first_extent_bit(info->pinned_extents, start,
-					    &extent_start, &extent_end,
-					    EXTENT_DIRTY | EXTENT_UPTODATE,
-					    NULL);
-		if (ret)
-			break;
-
-		if (extent_start <= start) {
-			start = extent_end + 1;
-		} else if (extent_start > start && extent_start < end) {
-			size = extent_start - start;
-			total_added += size;
-			ret = btrfs_add_free_space(block_group, start,
-						   size);
-			BUG_ON(ret); /* -ENOMEM or logic error */
-			start = extent_end + 1;
-		} else {
-			break;
-		}
-	}
-
-	if (start < end) {
-		size = end - start;
-		total_added += size;
-		ret = btrfs_add_free_space(block_group, start, size);
-		BUG_ON(ret); /* -ENOMEM or logic error */
-	}
-
-	return total_added;
+	return BTRFS_BLOCK_GROUP_DATA;
 }
 
-static int load_extent_tree_free(struct btrfs_caching_control *caching_ctl)
-{
-	struct btrfs_block_group_cache *block_group = caching_ctl->block_group;
-	struct btrfs_fs_info *fs_info = block_group->fs_info;
-	struct btrfs_root *extent_root = fs_info->extent_root;
-	struct btrfs_path *path;
-	struct extent_buffer *leaf;
-	struct btrfs_key key;
-	u64 total_found = 0;
-	u64 last = 0;
-	u32 nritems;
-	int ret;
-	bool wakeup = true;
-
-	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOMEM;
-
-	last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
-
-#ifdef CONFIG_BTRFS_DEBUG
-	/*
-	 * If we're fragmenting we don't want to make anybody think we can
-	 * allocate from this block group until we've had a chance to fragment
-	 * the free space.
-	 */
-	if (btrfs_should_fragment_free_space(block_group))
-		wakeup = false;
-#endif
-	/*
-	 * We don't want to deadlock with somebody trying to allocate a new
-	 * extent for the extent root while also trying to search the extent
-	 * root to add free space.  So we skip locking and search the commit
-	 * root, since its read-only
-	 */
-	path->skip_locking = 1;
-	path->search_commit_root = 1;
-	path->reada = READA_FORWARD;
-
-	key.objectid = last;
-	key.offset = 0;
-	key.type = BTRFS_EXTENT_ITEM_KEY;
-
-next:
-	ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
-	if (ret < 0)
-		goto out;
-
-	leaf = path->nodes[0];
-	nritems = btrfs_header_nritems(leaf);
-
-	while (1) {
-		if (btrfs_fs_closing(fs_info) > 1) {
-			last = (u64)-1;
-			break;
-		}
-
-		if (path->slots[0] < nritems) {
-			btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
-		} else {
-			ret = find_next_key(path, 0, &key);
-			if (ret)
-				break;
-
-			if (need_resched() ||
-			    rwsem_is_contended(&fs_info->commit_root_sem)) {
-				if (wakeup)
-					caching_ctl->progress = last;
-				btrfs_release_path(path);
-				up_read(&fs_info->commit_root_sem);
-				mutex_unlock(&caching_ctl->mutex);
-				cond_resched();
-				mutex_lock(&caching_ctl->mutex);
-				down_read(&fs_info->commit_root_sem);
-				goto next;
-			}
-
-			ret = btrfs_next_leaf(extent_root, path);
-			if (ret < 0)
-				goto out;
-			if (ret)
-				break;
-			leaf = path->nodes[0];
-			nritems = btrfs_header_nritems(leaf);
-			continue;
-		}
-
-		if (key.objectid < last) {
-			key.objectid = last;
-			key.offset = 0;
-			key.type = BTRFS_EXTENT_ITEM_KEY;
-
-			if (wakeup)
-				caching_ctl->progress = last;
-			btrfs_release_path(path);
-			goto next;
-		}
-
-		if (key.objectid < block_group->key.objectid) {
-			path->slots[0]++;
-			continue;
-		}
-
-		if (key.objectid >= block_group->key.objectid +
-		    block_group->key.offset)
-			break;
-
-		if (key.type == BTRFS_EXTENT_ITEM_KEY ||
-		    key.type == BTRFS_METADATA_ITEM_KEY) {
-			total_found += add_new_free_space(block_group, last,
-							  key.objectid);
-			if (key.type == BTRFS_METADATA_ITEM_KEY)
-				last = key.objectid +
-					fs_info->nodesize;
-			else
-				last = key.objectid + key.offset;
-
-			if (total_found > CACHING_CTL_WAKE_UP) {
-				total_found = 0;
-				if (wakeup)
-					wake_up(&caching_ctl->wait);
-			}
-		}
-		path->slots[0]++;
-	}
-	ret = 0;
-
-	total_found += add_new_free_space(block_group, last,
-					  block_group->key.objectid +
-					  block_group->key.offset);
-	caching_ctl->progress = (u64)-1;
-
-out:
-	btrfs_free_path(path);
-	return ret;
-}
-
-static noinline void caching_thread(struct btrfs_work *work)
-{
-	struct btrfs_block_group_cache *block_group;
-	struct btrfs_fs_info *fs_info;
-	struct btrfs_caching_control *caching_ctl;
-	int ret;
-
-	caching_ctl = container_of(work, struct btrfs_caching_control, work);
-	block_group = caching_ctl->block_group;
-	fs_info = block_group->fs_info;
-
-	mutex_lock(&caching_ctl->mutex);
-	down_read(&fs_info->commit_root_sem);
-
-	if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE))
-		ret = load_free_space_tree(caching_ctl);
-	else
-		ret = load_extent_tree_free(caching_ctl);
-
-	spin_lock(&block_group->lock);
-	block_group->caching_ctl = NULL;
-	block_group->cached = ret ? BTRFS_CACHE_ERROR : BTRFS_CACHE_FINISHED;
-	spin_unlock(&block_group->lock);
-
-#ifdef CONFIG_BTRFS_DEBUG
-	if (btrfs_should_fragment_free_space(block_group)) {
-		u64 bytes_used;
-
-		spin_lock(&block_group->space_info->lock);
-		spin_lock(&block_group->lock);
-		bytes_used = block_group->key.offset -
-			btrfs_block_group_used(&block_group->item);
-		block_group->space_info->bytes_used += bytes_used >> 1;
-		spin_unlock(&block_group->lock);
-		spin_unlock(&block_group->space_info->lock);
-		fragment_free_space(block_group);
-	}
-#endif
-
-	caching_ctl->progress = (u64)-1;
-
-	up_read(&fs_info->commit_root_sem);
-	free_excluded_extents(block_group);
-	mutex_unlock(&caching_ctl->mutex);
-
-	wake_up(&caching_ctl->wait);
-
-	put_caching_control(caching_ctl);
-	btrfs_put_block_group(block_group);
-}
-
-static int cache_block_group(struct btrfs_block_group_cache *cache,
-			     int load_cache_only)
-{
-	DEFINE_WAIT(wait);
-	struct btrfs_fs_info *fs_info = cache->fs_info;
-	struct btrfs_caching_control *caching_ctl;
-	int ret = 0;
-
-	caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS);
-	if (!caching_ctl)
-		return -ENOMEM;
-
-	INIT_LIST_HEAD(&caching_ctl->list);
-	mutex_init(&caching_ctl->mutex);
-	init_waitqueue_head(&caching_ctl->wait);
-	caching_ctl->block_group = cache;
-	caching_ctl->progress = cache->key.objectid;
-	refcount_set(&caching_ctl->count, 1);
-	btrfs_init_work(&caching_ctl->work, btrfs_cache_helper,
-			caching_thread, NULL, NULL);
-
-	spin_lock(&cache->lock);
-	/*
-	 * This should be a rare occasion, but this could happen I think in the
-	 * case where one thread starts to load the space cache info, and then
-	 * some other thread starts a transaction commit which tries to do an
-	 * allocation while the other thread is still loading the space cache
-	 * info.  The previous loop should have kept us from choosing this block
-	 * group, but if we've moved to the state where we will wait on caching
-	 * block groups we need to first check if we're doing a fast load here,
-	 * so we can wait for it to finish, otherwise we could end up allocating
-	 * from a block group who's cache gets evicted for one reason or
-	 * another.
-	 */
-	while (cache->cached == BTRFS_CACHE_FAST) {
-		struct btrfs_caching_control *ctl;
-
-		ctl = cache->caching_ctl;
-		refcount_inc(&ctl->count);
-		prepare_to_wait(&ctl->wait, &wait, TASK_UNINTERRUPTIBLE);
-		spin_unlock(&cache->lock);
-
-		schedule();
-
-		finish_wait(&ctl->wait, &wait);
-		put_caching_control(ctl);
-		spin_lock(&cache->lock);
-	}
-
-	if (cache->cached != BTRFS_CACHE_NO) {
-		spin_unlock(&cache->lock);
-		kfree(caching_ctl);
-		return 0;
-	}
-	WARN_ON(cache->caching_ctl);
-	cache->caching_ctl = caching_ctl;
-	cache->cached = BTRFS_CACHE_FAST;
-	spin_unlock(&cache->lock);
-
-	if (btrfs_test_opt(fs_info, SPACE_CACHE)) {
-		mutex_lock(&caching_ctl->mutex);
-		ret = load_free_space_cache(fs_info, cache);
-
-		spin_lock(&cache->lock);
-		if (ret == 1) {
-			cache->caching_ctl = NULL;
-			cache->cached = BTRFS_CACHE_FINISHED;
-			cache->last_byte_to_unpin = (u64)-1;
-			caching_ctl->progress = (u64)-1;
-		} else {
-			if (load_cache_only) {
-				cache->caching_ctl = NULL;
-				cache->cached = BTRFS_CACHE_NO;
-			} else {
-				cache->cached = BTRFS_CACHE_STARTED;
-				cache->has_caching_ctl = 1;
-			}
-		}
-		spin_unlock(&cache->lock);
-#ifdef CONFIG_BTRFS_DEBUG
-		if (ret == 1 &&
-		    btrfs_should_fragment_free_space(cache)) {
-			u64 bytes_used;
-
-			spin_lock(&cache->space_info->lock);
-			spin_lock(&cache->lock);
-			bytes_used = cache->key.offset -
-				btrfs_block_group_used(&cache->item);
-			cache->space_info->bytes_used += bytes_used >> 1;
-			spin_unlock(&cache->lock);
-			spin_unlock(&cache->space_info->lock);
-			fragment_free_space(cache);
-		}
-#endif
-		mutex_unlock(&caching_ctl->mutex);
-
-		wake_up(&caching_ctl->wait);
-		if (ret == 1) {
-			put_caching_control(caching_ctl);
-			free_excluded_extents(cache);
-			return 0;
-		}
-	} else {
-		/*
-		 * We're either using the free space tree or no caching at all.
-		 * Set cached to the appropriate value and wakeup any waiters.
-		 */
-		spin_lock(&cache->lock);
-		if (load_cache_only) {
-			cache->caching_ctl = NULL;
-			cache->cached = BTRFS_CACHE_NO;
-		} else {
-			cache->cached = BTRFS_CACHE_STARTED;
-			cache->has_caching_ctl = 1;
-		}
-		spin_unlock(&cache->lock);
-		wake_up(&caching_ctl->wait);
-	}
-
-	if (load_cache_only) {
-		put_caching_control(caching_ctl);
-		return 0;
-	}
-
-	down_write(&fs_info->commit_root_sem);
-	refcount_inc(&caching_ctl->count);
-	list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups);
-	up_write(&fs_info->commit_root_sem);
-
-	btrfs_get_block_group(cache);
-
-	btrfs_queue_work(fs_info->caching_workers, &caching_ctl->work);
-
-	return ret;
-}
-
-/*
- * return the block group that starts at or after bytenr
- */
-static struct btrfs_block_group_cache *
-btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr)
-{
-	return block_group_cache_tree_search(info, bytenr, 0);
-}
-
-/*
- * return the block group that contains the given bytenr
- */
-struct btrfs_block_group_cache *btrfs_lookup_block_group(
-						 struct btrfs_fs_info *info,
-						 u64 bytenr)
-{
-	return block_group_cache_tree_search(info, bytenr, 1);
-}
-
-static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
-						  u64 flags)
-{
-	struct list_head *head = &info->space_info;
-	struct btrfs_space_info *found;
-
-	flags &= BTRFS_BLOCK_GROUP_TYPE_MASK;
-
-	rcu_read_lock();
-	list_for_each_entry_rcu(found, head, list) {
-		if (found->flags & flags) {
-			rcu_read_unlock();
-			return found;
-		}
-	}
-	rcu_read_unlock();
-	return NULL;
-}
-
-static void add_pinned_bytes(struct btrfs_fs_info *fs_info, s64 num_bytes,
-			     bool metadata, u64 root_objectid)
+static void add_pinned_bytes(struct btrfs_fs_info *fs_info,
+			     struct btrfs_ref *ref)
 {
 	struct btrfs_space_info *space_info;
-	u64 flags;
+	u64 flags = generic_ref_to_space_flags(ref);
 
-	if (metadata) {
-		if (root_objectid == BTRFS_CHUNK_TREE_OBJECTID)
-			flags = BTRFS_BLOCK_GROUP_SYSTEM;
-		else
-			flags = BTRFS_BLOCK_GROUP_METADATA;
-	} else {
-		flags = BTRFS_BLOCK_GROUP_DATA;
-	}
-
-	space_info = __find_space_info(fs_info, flags);
+	space_info = btrfs_find_space_info(fs_info, flags);
 	ASSERT(space_info);
-	percpu_counter_add_batch(&space_info->total_bytes_pinned, num_bytes,
+	percpu_counter_add_batch(&space_info->total_bytes_pinned, ref->len,
 		    BTRFS_TOTAL_BYTES_PINNED_BATCH);
 }
 
-/*
- * after adding space to the filesystem, we need to clear the full flags
- * on all the space infos.
- */
-void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
+static void sub_pinned_bytes(struct btrfs_fs_info *fs_info,
+			     struct btrfs_ref *ref)
 {
-	struct list_head *head = &info->space_info;
-	struct btrfs_space_info *found;
+	struct btrfs_space_info *space_info;
+	u64 flags = generic_ref_to_space_flags(ref);
 
-	rcu_read_lock();
-	list_for_each_entry_rcu(found, head, list)
-		found->full = 0;
-	rcu_read_unlock();
+	space_info = btrfs_find_space_info(fs_info, flags);
+	ASSERT(space_info);
+	percpu_counter_add_batch(&space_info->total_bytes_pinned, -ref->len,
+		    BTRFS_TOTAL_BYTES_PINNED_BATCH);
 }
 
 /* simple helper to search for an existing data extent at a given offset */
@@ -1037,7 +382,7 @@
 
 /*
  * is_data == BTRFS_REF_TYPE_BLOCK, tree block type is required,
- * is_data == BTRFS_REF_TYPE_DATA, data type is requried,
+ * is_data == BTRFS_REF_TYPE_DATA, data type is requiried,
  * is_data == BTRFS_REF_TYPE_ANY, either type is OK.
  */
 int btrfs_get_extent_inline_ref_type(const struct extent_buffer *eb,
@@ -1093,18 +438,18 @@
 	return BTRFS_REF_TYPE_INVALID;
 }
 
-static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
+u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
 {
 	u32 high_crc = ~(u32)0;
 	u32 low_crc = ~(u32)0;
 	__le64 lenum;
 
 	lenum = cpu_to_le64(root_objectid);
-	high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
+	high_crc = btrfs_crc32c(high_crc, &lenum, sizeof(lenum));
 	lenum = cpu_to_le64(owner);
-	low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
+	low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
 	lenum = cpu_to_le64(offset);
-	low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
+	low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
 
 	return ((u64)high_crc << 31) ^ (u64)low_crc;
 }
@@ -1686,7 +1031,7 @@
 	type = extent_ref_type(parent, owner);
 	size = btrfs_extent_inline_ref_size(type);
 
-	btrfs_extend_item(fs_info, path, size);
+	btrfs_extend_item(path, size);
 
 	ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
 	refs = btrfs_extent_refs(leaf, ei);
@@ -1761,7 +1106,6 @@
 				  int *last_ref)
 {
 	struct extent_buffer *leaf = path->nodes[0];
-	struct btrfs_fs_info *fs_info = leaf->fs_info;
 	struct btrfs_extent_item *ei;
 	struct btrfs_extent_data_ref *dref = NULL;
 	struct btrfs_shared_data_ref *sref = NULL;
@@ -1816,7 +1160,7 @@
 			memmove_extent_buffer(leaf, ptr, ptr + size,
 					      end - ptr - size);
 		item_size -= size;
-		btrfs_truncate_item(fs_info, path, item_size, 1);
+		btrfs_truncate_item(path, item_size, 1);
 	}
 	btrfs_mark_buffer_dirty(leaf);
 }
@@ -1887,7 +1231,6 @@
 	return ret;
 }
 
-#define in_range(b, first, len)        ((b) >= (first) && (b) < (first) + (len))
 static int btrfs_issue_discard(struct block_device *bdev, u64 start, u64 len,
 			       u64 *discarded_bytes)
 {
@@ -2025,39 +1368,28 @@
 
 /* Can return -ENOMEM */
 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
-			 struct btrfs_root *root,
-			 u64 bytenr, u64 num_bytes, u64 parent,
-			 u64 root_objectid, u64 owner, u64 offset)
+			 struct btrfs_ref *generic_ref)
 {
-	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct btrfs_fs_info *fs_info = trans->fs_info;
 	int old_ref_mod, new_ref_mod;
 	int ret;
 
-	BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID &&
-	       root_objectid == BTRFS_TREE_LOG_OBJECTID);
+	ASSERT(generic_ref->type != BTRFS_REF_NOT_SET &&
+	       generic_ref->action);
+	BUG_ON(generic_ref->type == BTRFS_REF_METADATA &&
+	       generic_ref->tree_ref.root == BTRFS_TREE_LOG_OBJECTID);
 
-	btrfs_ref_tree_mod(root, bytenr, num_bytes, parent, root_objectid,
-			   owner, offset, BTRFS_ADD_DELAYED_REF);
-
-	if (owner < BTRFS_FIRST_FREE_OBJECTID) {
-		ret = btrfs_add_delayed_tree_ref(trans, bytenr,
-						 num_bytes, parent,
-						 root_objectid, (int)owner,
-						 BTRFS_ADD_DELAYED_REF, NULL,
+	if (generic_ref->type == BTRFS_REF_METADATA)
+		ret = btrfs_add_delayed_tree_ref(trans, generic_ref,
+				NULL, &old_ref_mod, &new_ref_mod);
+	else
+		ret = btrfs_add_delayed_data_ref(trans, generic_ref, 0,
 						 &old_ref_mod, &new_ref_mod);
-	} else {
-		ret = btrfs_add_delayed_data_ref(trans, bytenr,
-						 num_bytes, parent,
-						 root_objectid, owner, offset,
-						 0, BTRFS_ADD_DELAYED_REF,
-						 &old_ref_mod, &new_ref_mod);
-	}
 
-	if (ret == 0 && old_ref_mod < 0 && new_ref_mod >= 0) {
-		bool metadata = owner < BTRFS_FIRST_FREE_OBJECTID;
+	btrfs_ref_tree_mod(fs_info, generic_ref);
 
-		add_pinned_bytes(fs_info, -num_bytes, metadata, root_objectid);
-	}
+	if (ret == 0 && old_ref_mod < 0 && new_ref_mod >= 0)
+		sub_pinned_bytes(fs_info, generic_ref);
 
 	return ret;
 }
@@ -2377,7 +1709,7 @@
 {
 	struct btrfs_delayed_ref_node *ref;
 
-	if (RB_EMPTY_ROOT(&head->ref_tree))
+	if (RB_EMPTY_ROOT(&head->ref_tree.rb_root))
 		return NULL;
 
 	/*
@@ -2390,7 +1722,7 @@
 		return list_first_entry(&head->ref_add_list,
 				struct btrfs_delayed_ref_node, add_list);
 
-	ref = rb_entry(rb_first(&head->ref_tree),
+	ref = rb_entry(rb_first_cached(&head->ref_tree),
 		       struct btrfs_delayed_ref_node, ref_node);
 	ASSERT(list_empty(&ref->add_list));
 	return ref;
@@ -2406,25 +1738,77 @@
 	btrfs_delayed_ref_unlock(head);
 }
 
-static int cleanup_extent_op(struct btrfs_trans_handle *trans,
-			     struct btrfs_delayed_ref_head *head)
+static struct btrfs_delayed_extent_op *cleanup_extent_op(
+				struct btrfs_delayed_ref_head *head)
 {
 	struct btrfs_delayed_extent_op *extent_op = head->extent_op;
+
+	if (!extent_op)
+		return NULL;
+
+	if (head->must_insert_reserved) {
+		head->extent_op = NULL;
+		btrfs_free_delayed_extent_op(extent_op);
+		return NULL;
+	}
+	return extent_op;
+}
+
+static int run_and_cleanup_extent_op(struct btrfs_trans_handle *trans,
+				     struct btrfs_delayed_ref_head *head)
+{
+	struct btrfs_delayed_extent_op *extent_op;
 	int ret;
 
+	extent_op = cleanup_extent_op(head);
 	if (!extent_op)
 		return 0;
 	head->extent_op = NULL;
-	if (head->must_insert_reserved) {
-		btrfs_free_delayed_extent_op(extent_op);
-		return 0;
-	}
 	spin_unlock(&head->lock);
 	ret = run_delayed_extent_op(trans, head, extent_op);
 	btrfs_free_delayed_extent_op(extent_op);
 	return ret ? ret : 1;
 }
 
+void btrfs_cleanup_ref_head_accounting(struct btrfs_fs_info *fs_info,
+				  struct btrfs_delayed_ref_root *delayed_refs,
+				  struct btrfs_delayed_ref_head *head)
+{
+	int nr_items = 1;	/* Dropping this ref head update. */
+
+	if (head->total_ref_mod < 0) {
+		struct btrfs_space_info *space_info;
+		u64 flags;
+
+		if (head->is_data)
+			flags = BTRFS_BLOCK_GROUP_DATA;
+		else if (head->is_system)
+			flags = BTRFS_BLOCK_GROUP_SYSTEM;
+		else
+			flags = BTRFS_BLOCK_GROUP_METADATA;
+		space_info = btrfs_find_space_info(fs_info, flags);
+		ASSERT(space_info);
+		percpu_counter_add_batch(&space_info->total_bytes_pinned,
+				   -head->num_bytes,
+				   BTRFS_TOTAL_BYTES_PINNED_BATCH);
+
+		/*
+		 * We had csum deletions accounted for in our delayed refs rsv,
+		 * we need to drop the csum leaves for this update from our
+		 * delayed_refs_rsv.
+		 */
+		if (head->is_data) {
+			spin_lock(&delayed_refs->lock);
+			delayed_refs->pending_csums -= head->num_bytes;
+			spin_unlock(&delayed_refs->lock);
+			nr_items += btrfs_csum_bytes_to_leaves(fs_info,
+				head->num_bytes);
+		}
+	}
+
+	btrfs_delayed_refs_rsv_release(fs_info, nr_items);
+}
+
 static int cleanup_ref_head(struct btrfs_trans_handle *trans,
 			    struct btrfs_delayed_ref_head *head)
 {
@@ -2435,7 +1819,7 @@
 
 	delayed_refs = &trans->transaction->delayed_refs;
 
-	ret = cleanup_extent_op(trans, head);
+	ret = run_and_cleanup_extent_op(trans, head);
 	if (ret < 0) {
 		unselect_delayed_ref_head(delayed_refs, head);
 		btrfs_debug(fs_info, "run_delayed_extent_op returned %d", ret);
@@ -2451,42 +1835,14 @@
 	spin_unlock(&head->lock);
 	spin_lock(&delayed_refs->lock);
 	spin_lock(&head->lock);
-	if (!RB_EMPTY_ROOT(&head->ref_tree) || head->extent_op) {
+	if (!RB_EMPTY_ROOT(&head->ref_tree.rb_root) || head->extent_op) {
 		spin_unlock(&head->lock);
 		spin_unlock(&delayed_refs->lock);
 		return 1;
 	}
-	delayed_refs->num_heads--;
-	rb_erase(&head->href_node, &delayed_refs->href_root);
-	RB_CLEAR_NODE(&head->href_node);
+	btrfs_delete_ref_head(delayed_refs, head);
 	spin_unlock(&head->lock);
 	spin_unlock(&delayed_refs->lock);
-	atomic_dec(&delayed_refs->num_entries);
-
-	trace_run_delayed_ref_head(fs_info, head, 0);
-
-	if (head->total_ref_mod < 0) {
-		struct btrfs_space_info *space_info;
-		u64 flags;
-
-		if (head->is_data)
-			flags = BTRFS_BLOCK_GROUP_DATA;
-		else if (head->is_system)
-			flags = BTRFS_BLOCK_GROUP_SYSTEM;
-		else
-			flags = BTRFS_BLOCK_GROUP_METADATA;
-		space_info = __find_space_info(fs_info, flags);
-		ASSERT(space_info);
-		percpu_counter_add_batch(&space_info->total_bytes_pinned,
-				   -head->num_bytes,
-				   BTRFS_TOTAL_BYTES_PINNED_BATCH);
-
-		if (head->is_data) {
-			spin_lock(&delayed_refs->lock);
-			delayed_refs->pending_csums -= head->num_bytes;
-			spin_unlock(&delayed_refs->lock);
-		}
-	}
 
 	if (head->must_insert_reserved) {
 		btrfs_pin_extent(fs_info, head->bytenr,
@@ -2497,110 +1853,74 @@
 		}
 	}
 
-	/* Also free its reserved qgroup space */
-	btrfs_qgroup_free_delayed_ref(fs_info, head->qgroup_ref_root,
-				      head->qgroup_reserved);
+	btrfs_cleanup_ref_head_accounting(fs_info, delayed_refs, head);
+
+	trace_run_delayed_ref_head(fs_info, head, 0);
 	btrfs_delayed_ref_unlock(head);
 	btrfs_put_delayed_ref_head(head);
 	return 0;
 }
 
-/*
- * Returns 0 on success or if called with an already aborted transaction.
- * Returns -ENOMEM or -EIO on failure and will abort the transaction.
- */
-static noinline int __btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
-					     unsigned long nr)
+static struct btrfs_delayed_ref_head *btrfs_obtain_ref_head(
+					struct btrfs_trans_handle *trans)
+{
+	struct btrfs_delayed_ref_root *delayed_refs =
+		&trans->transaction->delayed_refs;
+	struct btrfs_delayed_ref_head *head = NULL;
+	int ret;
+
+	spin_lock(&delayed_refs->lock);
+	head = btrfs_select_ref_head(delayed_refs);
+	if (!head) {
+		spin_unlock(&delayed_refs->lock);
+		return head;
+	}
+
+	/*
+	 * Grab the lock that says we are going to process all the refs for
+	 * this head
+	 */
+	ret = btrfs_delayed_ref_lock(delayed_refs, head);
+	spin_unlock(&delayed_refs->lock);
+
+	/*
+	 * We may have dropped the spin lock to get the head mutex lock, and
+	 * that might have given someone else time to free the head.  If that's
+	 * true, it has been removed from our list and we can move on.
+	 */
+	if (ret == -EAGAIN)
+		head = ERR_PTR(-EAGAIN);
+
+	return head;
+}
+
+static int btrfs_run_delayed_refs_for_head(struct btrfs_trans_handle *trans,
+				    struct btrfs_delayed_ref_head *locked_ref,
+				    unsigned long *run_refs)
 {
 	struct btrfs_fs_info *fs_info = trans->fs_info;
 	struct btrfs_delayed_ref_root *delayed_refs;
-	struct btrfs_delayed_ref_node *ref;
-	struct btrfs_delayed_ref_head *locked_ref = NULL;
 	struct btrfs_delayed_extent_op *extent_op;
-	ktime_t start = ktime_get();
-	int ret;
-	unsigned long count = 0;
-	unsigned long actual_count = 0;
+	struct btrfs_delayed_ref_node *ref;
 	int must_insert_reserved = 0;
+	int ret;
 
 	delayed_refs = &trans->transaction->delayed_refs;
-	while (1) {
-		if (!locked_ref) {
-			if (count >= nr)
-				break;
 
-			spin_lock(&delayed_refs->lock);
-			locked_ref = btrfs_select_ref_head(trans);
-			if (!locked_ref) {
-				spin_unlock(&delayed_refs->lock);
-				break;
-			}
+	lockdep_assert_held(&locked_ref->mutex);
+	lockdep_assert_held(&locked_ref->lock);
 
-			/* grab the lock that says we are going to process
-			 * all the refs for this head */
-			ret = btrfs_delayed_ref_lock(trans, locked_ref);
-			spin_unlock(&delayed_refs->lock);
-			/*
-			 * we may have dropped the spin lock to get the head
-			 * mutex lock, and that might have given someone else
-			 * time to free the head.  If that's true, it has been
-			 * removed from our list and we can move on.
-			 */
-			if (ret == -EAGAIN) {
-				locked_ref = NULL;
-				count++;
-				continue;
-			}
-		}
-
-		/*
-		 * We need to try and merge add/drops of the same ref since we
-		 * can run into issues with relocate dropping the implicit ref
-		 * and then it being added back again before the drop can
-		 * finish.  If we merged anything we need to re-loop so we can
-		 * get a good ref.
-		 * Or we can get node references of the same type that weren't
-		 * merged when created due to bumps in the tree mod seq, and
-		 * we need to merge them to prevent adding an inline extent
-		 * backref before dropping it (triggering a BUG_ON at
-		 * insert_inline_extent_backref()).
-		 */
-		spin_lock(&locked_ref->lock);
-		btrfs_merge_delayed_refs(trans, delayed_refs, locked_ref);
-
-		ref = select_delayed_ref(locked_ref);
-
-		if (ref && ref->seq &&
+	while ((ref = select_delayed_ref(locked_ref))) {
+		if (ref->seq &&
 		    btrfs_check_delayed_seq(fs_info, ref->seq)) {
 			spin_unlock(&locked_ref->lock);
 			unselect_delayed_ref_head(delayed_refs, locked_ref);
-			locked_ref = NULL;
-			cond_resched();
-			count++;
-			continue;
+			return -EAGAIN;
 		}
 
-		/*
-		 * We're done processing refs in this ref_head, clean everything
-		 * up and move on to the next ref_head.
-		 */
-		if (!ref) {
-			ret = cleanup_ref_head(trans, locked_ref);
-			if (ret > 0 ) {
-				/* We dropped our lock, we need to loop. */
-				ret = 0;
-				continue;
-			} else if (ret) {
-				return ret;
-			}
-			locked_ref = NULL;
-			count++;
-			continue;
-		}
-
-		actual_count++;
+		(*run_refs)++;
 		ref->in_tree = 0;
-		rb_erase(&ref->ref_node, &locked_ref->ref_tree);
+		rb_erase_cached(&ref->ref_node, &locked_ref->ref_tree);
 		RB_CLEAR_NODE(&ref->ref_node);
 		if (!list_empty(&ref->add_list))
 			list_del(&ref->add_list);
@@ -2622,8 +1942,8 @@
 		atomic_dec(&delayed_refs->num_entries);
 
 		/*
-		 * Record the must-insert_reserved flag before we drop the spin
-		 * lock.
+		 * Record the must_insert_reserved flag before we drop the
+		 * spin lock.
 		 */
 		must_insert_reserved = locked_ref->must_insert_reserved;
 		locked_ref->must_insert_reserved = 0;
@@ -2645,10 +1965,90 @@
 		}
 
 		btrfs_put_delayed_ref(ref);
-		count++;
 		cond_resched();
+
+		spin_lock(&locked_ref->lock);
+		btrfs_merge_delayed_refs(trans, delayed_refs, locked_ref);
 	}
 
+	return 0;
+}
+
+/*
+ * Returns 0 on success or if called with an already aborted transaction.
+ * Returns -ENOMEM or -EIO on failure and will abort the transaction.
+ */
+static noinline int __btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
+					     unsigned long nr)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_delayed_ref_root *delayed_refs;
+	struct btrfs_delayed_ref_head *locked_ref = NULL;
+	ktime_t start = ktime_get();
+	int ret;
+	unsigned long count = 0;
+	unsigned long actual_count = 0;
+
+	delayed_refs = &trans->transaction->delayed_refs;
+	do {
+		if (!locked_ref) {
+			locked_ref = btrfs_obtain_ref_head(trans);
+			if (IS_ERR_OR_NULL(locked_ref)) {
+				if (PTR_ERR(locked_ref) == -EAGAIN) {
+					continue;
+				} else {
+					break;
+				}
+			}
+			count++;
+		}
+		/*
+		 * We need to try and merge add/drops of the same ref since we
+		 * can run into issues with relocate dropping the implicit ref
+		 * and then it being added back again before the drop can
+		 * finish.  If we merged anything we need to re-loop so we can
+		 * get a good ref.
+		 * Or we can get node references of the same type that weren't
+		 * merged when created due to bumps in the tree mod seq, and
+		 * we need to merge them to prevent adding an inline extent
+		 * backref before dropping it (triggering a BUG_ON at
+		 * insert_inline_extent_backref()).
+		 */
+		spin_lock(&locked_ref->lock);
+		btrfs_merge_delayed_refs(trans, delayed_refs, locked_ref);
+
+		ret = btrfs_run_delayed_refs_for_head(trans, locked_ref,
+						      &actual_count);
+		if (ret < 0 && ret != -EAGAIN) {
+			/*
+			 * Error, btrfs_run_delayed_refs_for_head already
+			 * unlocked everything so just bail out
+			 */
+			return ret;
+		} else if (!ret) {
+			/*
+			 * Success, perform the usual cleanup of a processed
+			 * head
+			 */
+			ret = cleanup_ref_head(trans, locked_ref);
+			if (ret > 0 ) {
+				/* We dropped our lock, we need to loop. */
+				ret = 0;
+				continue;
+			} else if (ret) {
+				return ret;
+			}
+		}
+
+		/*
+		 * Either success case or btrfs_run_delayed_refs_for_head
+		 * returned -EAGAIN, meaning we need to select another head
+		 */
+
+		locked_ref = NULL;
+		cond_resched();
+	} while ((nr != -1 && count < nr) || locked_ref);
+
 	/*
 	 * We don't want to include ref heads since we can have empty ref heads
 	 * and those will drastically skew our runtime down since we just do
@@ -2748,153 +2148,6 @@
 	return num_csums;
 }
 
-int btrfs_check_space_for_delayed_refs(struct btrfs_trans_handle *trans,
-				       struct btrfs_fs_info *fs_info)
-{
-	struct btrfs_block_rsv *global_rsv;
-	u64 num_heads = trans->transaction->delayed_refs.num_heads_ready;
-	u64 csum_bytes = trans->transaction->delayed_refs.pending_csums;
-	unsigned int num_dirty_bgs = trans->transaction->num_dirty_bgs;
-	u64 num_bytes, num_dirty_bgs_bytes;
-	int ret = 0;
-
-	num_bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
-	num_heads = heads_to_leaves(fs_info, num_heads);
-	if (num_heads > 1)
-		num_bytes += (num_heads - 1) * fs_info->nodesize;
-	num_bytes <<= 1;
-	num_bytes += btrfs_csum_bytes_to_leaves(fs_info, csum_bytes) *
-							fs_info->nodesize;
-	num_dirty_bgs_bytes = btrfs_calc_trans_metadata_size(fs_info,
-							     num_dirty_bgs);
-	global_rsv = &fs_info->global_block_rsv;
-
-	/*
-	 * If we can't allocate any more chunks lets make sure we have _lots_ of
-	 * wiggle room since running delayed refs can create more delayed refs.
-	 */
-	if (global_rsv->space_info->full) {
-		num_dirty_bgs_bytes <<= 1;
-		num_bytes <<= 1;
-	}
-
-	spin_lock(&global_rsv->lock);
-	if (global_rsv->reserved <= num_bytes + num_dirty_bgs_bytes)
-		ret = 1;
-	spin_unlock(&global_rsv->lock);
-	return ret;
-}
-
-int btrfs_should_throttle_delayed_refs(struct btrfs_trans_handle *trans,
-				       struct btrfs_fs_info *fs_info)
-{
-	u64 num_entries =
-		atomic_read(&trans->transaction->delayed_refs.num_entries);
-	u64 avg_runtime;
-	u64 val;
-
-	smp_mb();
-	avg_runtime = fs_info->avg_delayed_ref_runtime;
-	val = num_entries * avg_runtime;
-	if (val >= NSEC_PER_SEC)
-		return 1;
-	if (val >= NSEC_PER_SEC / 2)
-		return 2;
-
-	return btrfs_check_space_for_delayed_refs(trans, fs_info);
-}
-
-struct async_delayed_refs {
-	struct btrfs_root *root;
-	u64 transid;
-	int count;
-	int error;
-	int sync;
-	struct completion wait;
-	struct btrfs_work work;
-};
-
-static inline struct async_delayed_refs *
-to_async_delayed_refs(struct btrfs_work *work)
-{
-	return container_of(work, struct async_delayed_refs, work);
-}
-
-static void delayed_ref_async_start(struct btrfs_work *work)
-{
-	struct async_delayed_refs *async = to_async_delayed_refs(work);
-	struct btrfs_trans_handle *trans;
-	struct btrfs_fs_info *fs_info = async->root->fs_info;
-	int ret;
-
-	/* if the commit is already started, we don't need to wait here */
-	if (btrfs_transaction_blocked(fs_info))
-		goto done;
-
-	trans = btrfs_join_transaction(async->root);
-	if (IS_ERR(trans)) {
-		async->error = PTR_ERR(trans);
-		goto done;
-	}
-
-	/*
-	 * trans->sync means that when we call end_transaction, we won't
-	 * wait on delayed refs
-	 */
-	trans->sync = true;
-
-	/* Don't bother flushing if we got into a different transaction */
-	if (trans->transid > async->transid)
-		goto end;
-
-	ret = btrfs_run_delayed_refs(trans, async->count);
-	if (ret)
-		async->error = ret;
-end:
-	ret = btrfs_end_transaction(trans);
-	if (ret && !async->error)
-		async->error = ret;
-done:
-	if (async->sync)
-		complete(&async->wait);
-	else
-		kfree(async);
-}
-
-int btrfs_async_run_delayed_refs(struct btrfs_fs_info *fs_info,
-				 unsigned long count, u64 transid, int wait)
-{
-	struct async_delayed_refs *async;
-	int ret;
-
-	async = kmalloc(sizeof(*async), GFP_NOFS);
-	if (!async)
-		return -ENOMEM;
-
-	async->root = fs_info->tree_root;
-	async->count = count;
-	async->error = 0;
-	async->transid = transid;
-	if (wait)
-		async->sync = 1;
-	else
-		async->sync = 0;
-	init_completion(&async->wait);
-
-	btrfs_init_work(&async->work, btrfs_extent_refs_helper,
-			delayed_ref_async_start, NULL, NULL);
-
-	btrfs_queue_work(fs_info->extent_workers, &async->work);
-
-	if (wait) {
-		wait_for_completion(&async->wait);
-		ret = async->error;
-		kfree(async);
-		return ret;
-	}
-	return 0;
-}
-
 /*
  * this starts processing the delayed reference count updates and
  * extent insertions we have queued up so far.  count can be
@@ -2937,11 +2190,10 @@
 	}
 
 	if (run_all) {
-		if (!list_empty(&trans->new_bgs))
-			btrfs_create_pending_block_groups(trans);
+		btrfs_create_pending_block_groups(trans);
 
 		spin_lock(&delayed_refs->lock);
-		node = rb_first(&delayed_refs->href_root);
+		node = rb_first_cached(&delayed_refs->href_root);
 		if (!node) {
 			spin_unlock(&delayed_refs->lock);
 			goto out;
@@ -2964,7 +2216,6 @@
 }
 
 int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
-				struct btrfs_fs_info *fs_info,
 				u64 bytenr, u64 num_bytes, u64 flags,
 				int level, int is_data)
 {
@@ -2981,8 +2232,7 @@
 	extent_op->is_data = is_data ? true : false;
 	extent_op->level = level;
 
-	ret = btrfs_add_delayed_extent_op(fs_info, trans, bytenr,
-					  num_bytes, extent_op);
+	ret = btrfs_add_delayed_extent_op(trans, bytenr, num_bytes, extent_op);
 	if (ret)
 		btrfs_free_delayed_extent_op(extent_op);
 	return ret;
@@ -3040,7 +2290,8 @@
 	 * XXX: We should replace this with a proper search function in the
 	 * future.
 	 */
-	for (node = rb_first(&head->ref_tree); node; node = rb_next(node)) {
+	for (node = rb_first_cached(&head->ref_tree); node;
+	     node = rb_next(node)) {
 		ref = rb_entry(node, struct btrfs_delayed_ref_node, ref_node);
 		/* If it's a shared ref we know a cross reference exists */
 		if (ref->type != BTRFS_EXTENT_DATA_REF_KEY) {
@@ -3106,16 +2357,19 @@
 	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
 	ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
 
+	/* If extent item has more than 1 inline ref then it's shared */
 	if (item_size != sizeof(*ei) +
 	    btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY))
 		goto out;
 
+	/* If extent created before last snapshot => it's definitely shared */
 	if (btrfs_extent_generation(leaf, ei) <=
 	    btrfs_root_last_snapshot(&root->root_item))
 		goto out;
 
 	iref = (struct btrfs_extent_inline_ref *)(ei + 1);
 
+	/* If this extent has SHARED_DATA_REF then it's shared */
 	type = btrfs_get_extent_inline_ref_type(leaf, iref, BTRFS_REF_TYPE_DATA);
 	if (type != BTRFS_EXTENT_DATA_REF_KEY)
 		goto out;
@@ -3139,7 +2393,6 @@
 {
 	struct btrfs_path *path;
 	int ret;
-	int ret2;
 
 	path = btrfs_alloc_path();
 	if (!path)
@@ -3151,17 +2404,9 @@
 		if (ret && ret != -ENOENT)
 			goto out;
 
-		ret2 = check_delayed_ref(root, path, objectid,
-					 offset, bytenr);
-	} while (ret2 == -EAGAIN);
+		ret = check_delayed_ref(root, path, objectid, offset, bytenr);
+	} while (ret == -EAGAIN);
 
-	if (ret2 && ret2 != -ENOENT) {
-		ret = ret2;
-		goto out;
-	}
-
-	if (ret != -ENOENT || ret2 != -ENOENT)
-		ret = 0;
 out:
 	btrfs_free_path(path);
 	if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
@@ -3182,13 +2427,12 @@
 	u32 nritems;
 	struct btrfs_key key;
 	struct btrfs_file_extent_item *fi;
+	struct btrfs_ref generic_ref = { 0 };
+	bool for_reloc = btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC);
 	int i;
+	int action;
 	int level;
 	int ret = 0;
-	int (*process_func)(struct btrfs_trans_handle *,
-			    struct btrfs_root *,
-			    u64, u64, u64, u64, u64, u64);
-
 
 	if (btrfs_is_testing(fs_info))
 		return 0;
@@ -3200,15 +2444,14 @@
 	if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state) && level == 0)
 		return 0;
 
-	if (inc)
-		process_func = btrfs_inc_extent_ref;
-	else
-		process_func = btrfs_free_extent;
-
 	if (full_backref)
 		parent = buf->start;
 	else
 		parent = 0;
+	if (inc)
+		action = BTRFS_ADD_DELAYED_REF;
+	else
+		action = BTRFS_DROP_DELAYED_REF;
 
 	for (i = 0; i < nritems; i++) {
 		if (level == 0) {
@@ -3226,16 +2469,30 @@
 
 			num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
 			key.offset -= btrfs_file_extent_offset(buf, fi);
-			ret = process_func(trans, root, bytenr, num_bytes,
-					   parent, ref_root, key.objectid,
-					   key.offset);
+			btrfs_init_generic_ref(&generic_ref, action, bytenr,
+					       num_bytes, parent);
+			generic_ref.real_root = root->root_key.objectid;
+			btrfs_init_data_ref(&generic_ref, ref_root, key.objectid,
+					    key.offset);
+			generic_ref.skip_qgroup = for_reloc;
+			if (inc)
+				ret = btrfs_inc_extent_ref(trans, &generic_ref);
+			else
+				ret = btrfs_free_extent(trans, &generic_ref);
 			if (ret)
 				goto fail;
 		} else {
 			bytenr = btrfs_node_blockptr(buf, i);
 			num_bytes = fs_info->nodesize;
-			ret = process_func(trans, root, bytenr, num_bytes,
-					   parent, ref_root, level - 1, 0);
+			btrfs_init_generic_ref(&generic_ref, action, bytenr,
+					       num_bytes, parent);
+			generic_ref.real_root = root->root_key.objectid;
+			btrfs_init_tree_ref(&generic_ref, level - 1, ref_root);
+			generic_ref.skip_qgroup = for_reloc;
+			if (inc)
+				ret = btrfs_inc_extent_ref(trans, &generic_ref);
+			else
+				ret = btrfs_free_extent(trans, &generic_ref);
 			if (ret)
 				goto fail;
 		}
@@ -3257,552 +2514,6 @@
 	return __btrfs_mod_ref(trans, root, buf, full_backref, 0);
 }
 
-static int write_one_cache_group(struct btrfs_trans_handle *trans,
-				 struct btrfs_fs_info *fs_info,
-				 struct btrfs_path *path,
-				 struct btrfs_block_group_cache *cache)
-{
-	int ret;
-	struct btrfs_root *extent_root = fs_info->extent_root;
-	unsigned long bi;
-	struct extent_buffer *leaf;
-
-	ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
-	if (ret) {
-		if (ret > 0)
-			ret = -ENOENT;
-		goto fail;
-	}
-
-	leaf = path->nodes[0];
-	bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
-	write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
-	btrfs_mark_buffer_dirty(leaf);
-fail:
-	btrfs_release_path(path);
-	return ret;
-
-}
-
-static struct btrfs_block_group_cache *
-next_block_group(struct btrfs_fs_info *fs_info,
-		 struct btrfs_block_group_cache *cache)
-{
-	struct rb_node *node;
-
-	spin_lock(&fs_info->block_group_cache_lock);
-
-	/* If our block group was removed, we need a full search. */
-	if (RB_EMPTY_NODE(&cache->cache_node)) {
-		const u64 next_bytenr = cache->key.objectid + cache->key.offset;
-
-		spin_unlock(&fs_info->block_group_cache_lock);
-		btrfs_put_block_group(cache);
-		cache = btrfs_lookup_first_block_group(fs_info, next_bytenr); return cache;
-	}
-	node = rb_next(&cache->cache_node);
-	btrfs_put_block_group(cache);
-	if (node) {
-		cache = rb_entry(node, struct btrfs_block_group_cache,
-				 cache_node);
-		btrfs_get_block_group(cache);
-	} else
-		cache = NULL;
-	spin_unlock(&fs_info->block_group_cache_lock);
-	return cache;
-}
-
-static int cache_save_setup(struct btrfs_block_group_cache *block_group,
-			    struct btrfs_trans_handle *trans,
-			    struct btrfs_path *path)
-{
-	struct btrfs_fs_info *fs_info = block_group->fs_info;
-	struct btrfs_root *root = fs_info->tree_root;
-	struct inode *inode = NULL;
-	struct extent_changeset *data_reserved = NULL;
-	u64 alloc_hint = 0;
-	int dcs = BTRFS_DC_ERROR;
-	u64 num_pages = 0;
-	int retries = 0;
-	int ret = 0;
-
-	/*
-	 * If this block group is smaller than 100 megs don't bother caching the
-	 * block group.
-	 */
-	if (block_group->key.offset < (100 * SZ_1M)) {
-		spin_lock(&block_group->lock);
-		block_group->disk_cache_state = BTRFS_DC_WRITTEN;
-		spin_unlock(&block_group->lock);
-		return 0;
-	}
-
-	if (trans->aborted)
-		return 0;
-again:
-	inode = lookup_free_space_inode(fs_info, block_group, path);
-	if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) {
-		ret = PTR_ERR(inode);
-		btrfs_release_path(path);
-		goto out;
-	}
-
-	if (IS_ERR(inode)) {
-		BUG_ON(retries);
-		retries++;
-
-		if (block_group->ro)
-			goto out_free;
-
-		ret = create_free_space_inode(fs_info, trans, block_group,
-					      path);
-		if (ret)
-			goto out_free;
-		goto again;
-	}
-
-	/*
-	 * We want to set the generation to 0, that way if anything goes wrong
-	 * from here on out we know not to trust this cache when we load up next
-	 * time.
-	 */
-	BTRFS_I(inode)->generation = 0;
-	ret = btrfs_update_inode(trans, root, inode);
-	if (ret) {
-		/*
-		 * So theoretically we could recover from this, simply set the
-		 * super cache generation to 0 so we know to invalidate the
-		 * cache, but then we'd have to keep track of the block groups
-		 * that fail this way so we know we _have_ to reset this cache
-		 * before the next commit or risk reading stale cache.  So to
-		 * limit our exposure to horrible edge cases lets just abort the
-		 * transaction, this only happens in really bad situations
-		 * anyway.
-		 */
-		btrfs_abort_transaction(trans, ret);
-		goto out_put;
-	}
-	WARN_ON(ret);
-
-	/* We've already setup this transaction, go ahead and exit */
-	if (block_group->cache_generation == trans->transid &&
-	    i_size_read(inode)) {
-		dcs = BTRFS_DC_SETUP;
-		goto out_put;
-	}
-
-	if (i_size_read(inode) > 0) {
-		ret = btrfs_check_trunc_cache_free_space(fs_info,
-					&fs_info->global_block_rsv);
-		if (ret)
-			goto out_put;
-
-		ret = btrfs_truncate_free_space_cache(trans, NULL, inode);
-		if (ret)
-			goto out_put;
-	}
-
-	spin_lock(&block_group->lock);
-	if (block_group->cached != BTRFS_CACHE_FINISHED ||
-	    !btrfs_test_opt(fs_info, SPACE_CACHE)) {
-		/*
-		 * don't bother trying to write stuff out _if_
-		 * a) we're not cached,
-		 * b) we're with nospace_cache mount option,
-		 * c) we're with v2 space_cache (FREE_SPACE_TREE).
-		 */
-		dcs = BTRFS_DC_WRITTEN;
-		spin_unlock(&block_group->lock);
-		goto out_put;
-	}
-	spin_unlock(&block_group->lock);
-
-	/*
-	 * We hit an ENOSPC when setting up the cache in this transaction, just
-	 * skip doing the setup, we've already cleared the cache so we're safe.
-	 */
-	if (test_bit(BTRFS_TRANS_CACHE_ENOSPC, &trans->transaction->flags)) {
-		ret = -ENOSPC;
-		goto out_put;
-	}
-
-	/*
-	 * Try to preallocate enough space based on how big the block group is.
-	 * Keep in mind this has to include any pinned space which could end up
-	 * taking up quite a bit since it's not folded into the other space
-	 * cache.
-	 */
-	num_pages = div_u64(block_group->key.offset, SZ_256M);
-	if (!num_pages)
-		num_pages = 1;
-
-	num_pages *= 16;
-	num_pages *= PAGE_SIZE;
-
-	ret = btrfs_check_data_free_space(inode, &data_reserved, 0, num_pages);
-	if (ret)
-		goto out_put;
-
-	ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, num_pages,
-					      num_pages, num_pages,
-					      &alloc_hint);
-	/*
-	 * Our cache requires contiguous chunks so that we don't modify a bunch
-	 * of metadata or split extents when writing the cache out, which means
-	 * we can enospc if we are heavily fragmented in addition to just normal
-	 * out of space conditions.  So if we hit this just skip setting up any
-	 * other block groups for this transaction, maybe we'll unpin enough
-	 * space the next time around.
-	 */
-	if (!ret)
-		dcs = BTRFS_DC_SETUP;
-	else if (ret == -ENOSPC)
-		set_bit(BTRFS_TRANS_CACHE_ENOSPC, &trans->transaction->flags);
-
-out_put:
-	iput(inode);
-out_free:
-	btrfs_release_path(path);
-out:
-	spin_lock(&block_group->lock);
-	if (!ret && dcs == BTRFS_DC_SETUP)
-		block_group->cache_generation = trans->transid;
-	block_group->disk_cache_state = dcs;
-	spin_unlock(&block_group->lock);
-
-	extent_changeset_free(data_reserved);
-	return ret;
-}
-
-int btrfs_setup_space_cache(struct btrfs_trans_handle *trans,
-			    struct btrfs_fs_info *fs_info)
-{
-	struct btrfs_block_group_cache *cache, *tmp;
-	struct btrfs_transaction *cur_trans = trans->transaction;
-	struct btrfs_path *path;
-
-	if (list_empty(&cur_trans->dirty_bgs) ||
-	    !btrfs_test_opt(fs_info, SPACE_CACHE))
-		return 0;
-
-	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOMEM;
-
-	/* Could add new block groups, use _safe just in case */
-	list_for_each_entry_safe(cache, tmp, &cur_trans->dirty_bgs,
-				 dirty_list) {
-		if (cache->disk_cache_state == BTRFS_DC_CLEAR)
-			cache_save_setup(cache, trans, path);
-	}
-
-	btrfs_free_path(path);
-	return 0;
-}
-
-/*
- * transaction commit does final block group cache writeback during a
- * critical section where nothing is allowed to change the FS.  This is
- * required in order for the cache to actually match the block group,
- * but can introduce a lot of latency into the commit.
- *
- * So, btrfs_start_dirty_block_groups is here to kick off block group
- * cache IO.  There's a chance we'll have to redo some of it if the
- * block group changes again during the commit, but it greatly reduces
- * the commit latency by getting rid of the easy block groups while
- * we're still allowing others to join the commit.
- */
-int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans)
-{
-	struct btrfs_fs_info *fs_info = trans->fs_info;
-	struct btrfs_block_group_cache *cache;
-	struct btrfs_transaction *cur_trans = trans->transaction;
-	int ret = 0;
-	int should_put;
-	struct btrfs_path *path = NULL;
-	LIST_HEAD(dirty);
-	struct list_head *io = &cur_trans->io_bgs;
-	int num_started = 0;
-	int loops = 0;
-
-	spin_lock(&cur_trans->dirty_bgs_lock);
-	if (list_empty(&cur_trans->dirty_bgs)) {
-		spin_unlock(&cur_trans->dirty_bgs_lock);
-		return 0;
-	}
-	list_splice_init(&cur_trans->dirty_bgs, &dirty);
-	spin_unlock(&cur_trans->dirty_bgs_lock);
-
-again:
-	/*
-	 * make sure all the block groups on our dirty list actually
-	 * exist
-	 */
-	btrfs_create_pending_block_groups(trans);
-
-	if (!path) {
-		path = btrfs_alloc_path();
-		if (!path)
-			return -ENOMEM;
-	}
-
-	/*
-	 * cache_write_mutex is here only to save us from balance or automatic
-	 * removal of empty block groups deleting this block group while we are
-	 * writing out the cache
-	 */
-	mutex_lock(&trans->transaction->cache_write_mutex);
-	while (!list_empty(&dirty)) {
-		cache = list_first_entry(&dirty,
-					 struct btrfs_block_group_cache,
-					 dirty_list);
-		/*
-		 * this can happen if something re-dirties a block
-		 * group that is already under IO.  Just wait for it to
-		 * finish and then do it all again
-		 */
-		if (!list_empty(&cache->io_list)) {
-			list_del_init(&cache->io_list);
-			btrfs_wait_cache_io(trans, cache, path);
-			btrfs_put_block_group(cache);
-		}
-
-
-		/*
-		 * btrfs_wait_cache_io uses the cache->dirty_list to decide
-		 * if it should update the cache_state.  Don't delete
-		 * until after we wait.
-		 *
-		 * Since we're not running in the commit critical section
-		 * we need the dirty_bgs_lock to protect from update_block_group
-		 */
-		spin_lock(&cur_trans->dirty_bgs_lock);
-		list_del_init(&cache->dirty_list);
-		spin_unlock(&cur_trans->dirty_bgs_lock);
-
-		should_put = 1;
-
-		cache_save_setup(cache, trans, path);
-
-		if (cache->disk_cache_state == BTRFS_DC_SETUP) {
-			cache->io_ctl.inode = NULL;
-			ret = btrfs_write_out_cache(fs_info, trans,
-						    cache, path);
-			if (ret == 0 && cache->io_ctl.inode) {
-				num_started++;
-				should_put = 0;
-
-				/*
-				 * The cache_write_mutex is protecting the
-				 * io_list, also refer to the definition of
-				 * btrfs_transaction::io_bgs for more details
-				 */
-				list_add_tail(&cache->io_list, io);
-			} else {
-				/*
-				 * if we failed to write the cache, the
-				 * generation will be bad and life goes on
-				 */
-				ret = 0;
-			}
-		}
-		if (!ret) {
-			ret = write_one_cache_group(trans, fs_info,
-						    path, cache);
-			/*
-			 * Our block group might still be attached to the list
-			 * of new block groups in the transaction handle of some
-			 * other task (struct btrfs_trans_handle->new_bgs). This
-			 * means its block group item isn't yet in the extent
-			 * tree. If this happens ignore the error, as we will
-			 * try again later in the critical section of the
-			 * transaction commit.
-			 */
-			if (ret == -ENOENT) {
-				ret = 0;
-				spin_lock(&cur_trans->dirty_bgs_lock);
-				if (list_empty(&cache->dirty_list)) {
-					list_add_tail(&cache->dirty_list,
-						      &cur_trans->dirty_bgs);
-					btrfs_get_block_group(cache);
-				}
-				spin_unlock(&cur_trans->dirty_bgs_lock);
-			} else if (ret) {
-				btrfs_abort_transaction(trans, ret);
-			}
-		}
-
-		/* if its not on the io list, we need to put the block group */
-		if (should_put)
-			btrfs_put_block_group(cache);
-
-		if (ret)
-			break;
-
-		/*
-		 * Avoid blocking other tasks for too long. It might even save
-		 * us from writing caches for block groups that are going to be
-		 * removed.
-		 */
-		mutex_unlock(&trans->transaction->cache_write_mutex);
-		mutex_lock(&trans->transaction->cache_write_mutex);
-	}
-	mutex_unlock(&trans->transaction->cache_write_mutex);
-
-	/*
-	 * go through delayed refs for all the stuff we've just kicked off
-	 * and then loop back (just once)
-	 */
-	ret = btrfs_run_delayed_refs(trans, 0);
-	if (!ret && loops == 0) {
-		loops++;
-		spin_lock(&cur_trans->dirty_bgs_lock);
-		list_splice_init(&cur_trans->dirty_bgs, &dirty);
-		/*
-		 * dirty_bgs_lock protects us from concurrent block group
-		 * deletes too (not just cache_write_mutex).
-		 */
-		if (!list_empty(&dirty)) {
-			spin_unlock(&cur_trans->dirty_bgs_lock);
-			goto again;
-		}
-		spin_unlock(&cur_trans->dirty_bgs_lock);
-	} else if (ret < 0) {
-		btrfs_cleanup_dirty_bgs(cur_trans, fs_info);
-	}
-
-	btrfs_free_path(path);
-	return ret;
-}
-
-int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
-				   struct btrfs_fs_info *fs_info)
-{
-	struct btrfs_block_group_cache *cache;
-	struct btrfs_transaction *cur_trans = trans->transaction;
-	int ret = 0;
-	int should_put;
-	struct btrfs_path *path;
-	struct list_head *io = &cur_trans->io_bgs;
-	int num_started = 0;
-
-	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOMEM;
-
-	/*
-	 * Even though we are in the critical section of the transaction commit,
-	 * we can still have concurrent tasks adding elements to this
-	 * transaction's list of dirty block groups. These tasks correspond to
-	 * endio free space workers started when writeback finishes for a
-	 * space cache, which run inode.c:btrfs_finish_ordered_io(), and can
-	 * allocate new block groups as a result of COWing nodes of the root
-	 * tree when updating the free space inode. The writeback for the space
-	 * caches is triggered by an earlier call to
-	 * btrfs_start_dirty_block_groups() and iterations of the following
-	 * loop.
-	 * Also we want to do the cache_save_setup first and then run the
-	 * delayed refs to make sure we have the best chance at doing this all
-	 * in one shot.
-	 */
-	spin_lock(&cur_trans->dirty_bgs_lock);
-	while (!list_empty(&cur_trans->dirty_bgs)) {
-		cache = list_first_entry(&cur_trans->dirty_bgs,
-					 struct btrfs_block_group_cache,
-					 dirty_list);
-
-		/*
-		 * this can happen if cache_save_setup re-dirties a block
-		 * group that is already under IO.  Just wait for it to
-		 * finish and then do it all again
-		 */
-		if (!list_empty(&cache->io_list)) {
-			spin_unlock(&cur_trans->dirty_bgs_lock);
-			list_del_init(&cache->io_list);
-			btrfs_wait_cache_io(trans, cache, path);
-			btrfs_put_block_group(cache);
-			spin_lock(&cur_trans->dirty_bgs_lock);
-		}
-
-		/*
-		 * don't remove from the dirty list until after we've waited
-		 * on any pending IO
-		 */
-		list_del_init(&cache->dirty_list);
-		spin_unlock(&cur_trans->dirty_bgs_lock);
-		should_put = 1;
-
-		cache_save_setup(cache, trans, path);
-
-		if (!ret)
-			ret = btrfs_run_delayed_refs(trans,
-						     (unsigned long) -1);
-
-		if (!ret && cache->disk_cache_state == BTRFS_DC_SETUP) {
-			cache->io_ctl.inode = NULL;
-			ret = btrfs_write_out_cache(fs_info, trans,
-						    cache, path);
-			if (ret == 0 && cache->io_ctl.inode) {
-				num_started++;
-				should_put = 0;
-				list_add_tail(&cache->io_list, io);
-			} else {
-				/*
-				 * if we failed to write the cache, the
-				 * generation will be bad and life goes on
-				 */
-				ret = 0;
-			}
-		}
-		if (!ret) {
-			ret = write_one_cache_group(trans, fs_info,
-						    path, cache);
-			/*
-			 * One of the free space endio workers might have
-			 * created a new block group while updating a free space
-			 * cache's inode (at inode.c:btrfs_finish_ordered_io())
-			 * and hasn't released its transaction handle yet, in
-			 * which case the new block group is still attached to
-			 * its transaction handle and its creation has not
-			 * finished yet (no block group item in the extent tree
-			 * yet, etc). If this is the case, wait for all free
-			 * space endio workers to finish and retry. This is a
-			 * a very rare case so no need for a more efficient and
-			 * complex approach.
-			 */
-			if (ret == -ENOENT) {
-				wait_event(cur_trans->writer_wait,
-				   atomic_read(&cur_trans->num_writers) == 1);
-				ret = write_one_cache_group(trans, fs_info,
-							    path, cache);
-			}
-			if (ret)
-				btrfs_abort_transaction(trans, ret);
-		}
-
-		/* if its not on the io list, we need to put the block group */
-		if (should_put)
-			btrfs_put_block_group(cache);
-		spin_lock(&cur_trans->dirty_bgs_lock);
-	}
-	spin_unlock(&cur_trans->dirty_bgs_lock);
-
-	/*
-	 * Refer to the definition of io_bgs member for details why it's safe
-	 * to use it without any locking
-	 */
-	while (!list_empty(io)) {
-		cache = list_first_entry(io, struct btrfs_block_group_cache,
-					 io_list);
-		list_del_init(&cache->io_list);
-		btrfs_wait_cache_io(trans, cache, path);
-		btrfs_put_block_group(cache);
-	}
-
-	btrfs_free_path(path);
-	return ret;
-}
-
 int btrfs_extent_readonly(struct btrfs_fs_info *fs_info, u64 bytenr)
 {
 	struct btrfs_block_group_cache *block_group;
@@ -3816,254 +2527,6 @@
 	return readonly;
 }
 
-bool btrfs_inc_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr)
-{
-	struct btrfs_block_group_cache *bg;
-	bool ret = true;
-
-	bg = btrfs_lookup_block_group(fs_info, bytenr);
-	if (!bg)
-		return false;
-
-	spin_lock(&bg->lock);
-	if (bg->ro)
-		ret = false;
-	else
-		atomic_inc(&bg->nocow_writers);
-	spin_unlock(&bg->lock);
-
-	/* no put on block group, done by btrfs_dec_nocow_writers */
-	if (!ret)
-		btrfs_put_block_group(bg);
-
-	return ret;
-
-}
-
-void btrfs_dec_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr)
-{
-	struct btrfs_block_group_cache *bg;
-
-	bg = btrfs_lookup_block_group(fs_info, bytenr);
-	ASSERT(bg);
-	if (atomic_dec_and_test(&bg->nocow_writers))
-		wake_up_var(&bg->nocow_writers);
-	/*
-	 * Once for our lookup and once for the lookup done by a previous call
-	 * to btrfs_inc_nocow_writers()
-	 */
-	btrfs_put_block_group(bg);
-	btrfs_put_block_group(bg);
-}
-
-void btrfs_wait_nocow_writers(struct btrfs_block_group_cache *bg)
-{
-	wait_var_event(&bg->nocow_writers, !atomic_read(&bg->nocow_writers));
-}
-
-static const char *alloc_name(u64 flags)
-{
-	switch (flags) {
-	case BTRFS_BLOCK_GROUP_METADATA|BTRFS_BLOCK_GROUP_DATA:
-		return "mixed";
-	case BTRFS_BLOCK_GROUP_METADATA:
-		return "metadata";
-	case BTRFS_BLOCK_GROUP_DATA:
-		return "data";
-	case BTRFS_BLOCK_GROUP_SYSTEM:
-		return "system";
-	default:
-		WARN_ON(1);
-		return "invalid-combination";
-	};
-}
-
-static int create_space_info(struct btrfs_fs_info *info, u64 flags)
-{
-
-	struct btrfs_space_info *space_info;
-	int i;
-	int ret;
-
-	space_info = kzalloc(sizeof(*space_info), GFP_NOFS);
-	if (!space_info)
-		return -ENOMEM;
-
-	ret = percpu_counter_init(&space_info->total_bytes_pinned, 0,
-				 GFP_KERNEL);
-	if (ret) {
-		kfree(space_info);
-		return ret;
-	}
-
-	for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)
-		INIT_LIST_HEAD(&space_info->block_groups[i]);
-	init_rwsem(&space_info->groups_sem);
-	spin_lock_init(&space_info->lock);
-	space_info->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;
-	space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
-	init_waitqueue_head(&space_info->wait);
-	INIT_LIST_HEAD(&space_info->ro_bgs);
-	INIT_LIST_HEAD(&space_info->tickets);
-	INIT_LIST_HEAD(&space_info->priority_tickets);
-
-	ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
-				    info->space_info_kobj, "%s",
-				    alloc_name(space_info->flags));
-	if (ret) {
-		percpu_counter_destroy(&space_info->total_bytes_pinned);
-		kfree(space_info);
-		return ret;
-	}
-
-	list_add_rcu(&space_info->list, &info->space_info);
-	if (flags & BTRFS_BLOCK_GROUP_DATA)
-		info->data_sinfo = space_info;
-
-	return ret;
-}
-
-static void update_space_info(struct btrfs_fs_info *info, u64 flags,
-			     u64 total_bytes, u64 bytes_used,
-			     u64 bytes_readonly,
-			     struct btrfs_space_info **space_info)
-{
-	struct btrfs_space_info *found;
-	int factor;
-
-	factor = btrfs_bg_type_to_factor(flags);
-
-	found = __find_space_info(info, flags);
-	ASSERT(found);
-	spin_lock(&found->lock);
-	found->total_bytes += total_bytes;
-	found->disk_total += total_bytes * factor;
-	found->bytes_used += bytes_used;
-	found->disk_used += bytes_used * factor;
-	found->bytes_readonly += bytes_readonly;
-	if (total_bytes > 0)
-		found->full = 0;
-	space_info_add_new_bytes(info, found, total_bytes -
-				 bytes_used - bytes_readonly);
-	spin_unlock(&found->lock);
-	*space_info = found;
-}
-
-static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
-{
-	u64 extra_flags = chunk_to_extended(flags) &
-				BTRFS_EXTENDED_PROFILE_MASK;
-
-	write_seqlock(&fs_info->profiles_lock);
-	if (flags & BTRFS_BLOCK_GROUP_DATA)
-		fs_info->avail_data_alloc_bits |= extra_flags;
-	if (flags & BTRFS_BLOCK_GROUP_METADATA)
-		fs_info->avail_metadata_alloc_bits |= extra_flags;
-	if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
-		fs_info->avail_system_alloc_bits |= extra_flags;
-	write_sequnlock(&fs_info->profiles_lock);
-}
-
-/*
- * returns target flags in extended format or 0 if restripe for this
- * chunk_type is not in progress
- *
- * should be called with balance_lock held
- */
-static u64 get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags)
-{
-	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
-	u64 target = 0;
-
-	if (!bctl)
-		return 0;
-
-	if (flags & BTRFS_BLOCK_GROUP_DATA &&
-	    bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) {
-		target = BTRFS_BLOCK_GROUP_DATA | bctl->data.target;
-	} else if (flags & BTRFS_BLOCK_GROUP_SYSTEM &&
-		   bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
-		target = BTRFS_BLOCK_GROUP_SYSTEM | bctl->sys.target;
-	} else if (flags & BTRFS_BLOCK_GROUP_METADATA &&
-		   bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) {
-		target = BTRFS_BLOCK_GROUP_METADATA | bctl->meta.target;
-	}
-
-	return target;
-}
-
-/*
- * @flags: available profiles in extended format (see ctree.h)
- *
- * Returns reduced profile in chunk format.  If profile changing is in
- * progress (either running or paused) picks the target profile (if it's
- * already available), otherwise falls back to plain reducing.
- */
-static u64 btrfs_reduce_alloc_profile(struct btrfs_fs_info *fs_info, u64 flags)
-{
-	u64 num_devices = fs_info->fs_devices->rw_devices;
-	u64 target;
-	u64 raid_type;
-	u64 allowed = 0;
-
-	/*
-	 * see if restripe for this chunk_type is in progress, if so
-	 * try to reduce to the target profile
-	 */
-	spin_lock(&fs_info->balance_lock);
-	target = get_restripe_target(fs_info, flags);
-	if (target) {
-		/* pick target profile only if it's already available */
-		if ((flags & target) & BTRFS_EXTENDED_PROFILE_MASK) {
-			spin_unlock(&fs_info->balance_lock);
-			return extended_to_chunk(target);
-		}
-	}
-	spin_unlock(&fs_info->balance_lock);
-
-	/* First, mask out the RAID levels which aren't possible */
-	for (raid_type = 0; raid_type < BTRFS_NR_RAID_TYPES; raid_type++) {
-		if (num_devices >= btrfs_raid_array[raid_type].devs_min)
-			allowed |= btrfs_raid_array[raid_type].bg_flag;
-	}
-	allowed &= flags;
-
-	if (allowed & BTRFS_BLOCK_GROUP_RAID6)
-		allowed = BTRFS_BLOCK_GROUP_RAID6;
-	else if (allowed & BTRFS_BLOCK_GROUP_RAID5)
-		allowed = BTRFS_BLOCK_GROUP_RAID5;
-	else if (allowed & BTRFS_BLOCK_GROUP_RAID10)
-		allowed = BTRFS_BLOCK_GROUP_RAID10;
-	else if (allowed & BTRFS_BLOCK_GROUP_RAID1)
-		allowed = BTRFS_BLOCK_GROUP_RAID1;
-	else if (allowed & BTRFS_BLOCK_GROUP_RAID0)
-		allowed = BTRFS_BLOCK_GROUP_RAID0;
-
-	flags &= ~BTRFS_BLOCK_GROUP_PROFILE_MASK;
-
-	return extended_to_chunk(flags | allowed);
-}
-
-static u64 get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags)
-{
-	unsigned seq;
-	u64 flags;
-
-	do {
-		flags = orig_flags;
-		seq = read_seqbegin(&fs_info->profiles_lock);
-
-		if (flags & BTRFS_BLOCK_GROUP_DATA)
-			flags |= fs_info->avail_data_alloc_bits;
-		else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
-			flags |= fs_info->avail_system_alloc_bits;
-		else if (flags & BTRFS_BLOCK_GROUP_METADATA)
-			flags |= fs_info->avail_metadata_alloc_bits;
-	} while (read_seqretry(&fs_info->profiles_lock, seq));
-
-	return btrfs_reduce_alloc_profile(fs_info, flags);
-}
-
 static u64 get_alloc_profile_by_root(struct btrfs_root *root, int data)
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
@@ -4077,2089 +2540,10 @@
 	else
 		flags = BTRFS_BLOCK_GROUP_METADATA;
 
-	ret = get_alloc_profile(fs_info, flags);
+	ret = btrfs_get_alloc_profile(fs_info, flags);
 	return ret;
 }
 
-u64 btrfs_data_alloc_profile(struct btrfs_fs_info *fs_info)
-{
-	return get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_DATA);
-}
-
-u64 btrfs_metadata_alloc_profile(struct btrfs_fs_info *fs_info)
-{
-	return get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_METADATA);
-}
-
-u64 btrfs_system_alloc_profile(struct btrfs_fs_info *fs_info)
-{
-	return get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
-}
-
-static u64 btrfs_space_info_used(struct btrfs_space_info *s_info,
-				 bool may_use_included)
-{
-	ASSERT(s_info);
-	return s_info->bytes_used + s_info->bytes_reserved +
-		s_info->bytes_pinned + s_info->bytes_readonly +
-		(may_use_included ? s_info->bytes_may_use : 0);
-}
-
-int btrfs_alloc_data_chunk_ondemand(struct btrfs_inode *inode, u64 bytes)
-{
-	struct btrfs_root *root = inode->root;
-	struct btrfs_fs_info *fs_info = root->fs_info;
-	struct btrfs_space_info *data_sinfo = fs_info->data_sinfo;
-	u64 used;
-	int ret = 0;
-	int need_commit = 2;
-	int have_pinned_space;
-
-	/* make sure bytes are sectorsize aligned */
-	bytes = ALIGN(bytes, fs_info->sectorsize);
-
-	if (btrfs_is_free_space_inode(inode)) {
-		need_commit = 0;
-		ASSERT(current->journal_info);
-	}
-
-again:
-	/* make sure we have enough space to handle the data first */
-	spin_lock(&data_sinfo->lock);
-	used = btrfs_space_info_used(data_sinfo, true);
-
-	if (used + bytes > data_sinfo->total_bytes) {
-		struct btrfs_trans_handle *trans;
-
-		/*
-		 * if we don't have enough free bytes in this space then we need
-		 * to alloc a new chunk.
-		 */
-		if (!data_sinfo->full) {
-			u64 alloc_target;
-
-			data_sinfo->force_alloc = CHUNK_ALLOC_FORCE;
-			spin_unlock(&data_sinfo->lock);
-
-			alloc_target = btrfs_data_alloc_profile(fs_info);
-			/*
-			 * It is ugly that we don't call nolock join
-			 * transaction for the free space inode case here.
-			 * But it is safe because we only do the data space
-			 * reservation for the free space cache in the
-			 * transaction context, the common join transaction
-			 * just increase the counter of the current transaction
-			 * handler, doesn't try to acquire the trans_lock of
-			 * the fs.
-			 */
-			trans = btrfs_join_transaction(root);
-			if (IS_ERR(trans))
-				return PTR_ERR(trans);
-
-			ret = do_chunk_alloc(trans, alloc_target,
-					     CHUNK_ALLOC_NO_FORCE);
-			btrfs_end_transaction(trans);
-			if (ret < 0) {
-				if (ret != -ENOSPC)
-					return ret;
-				else {
-					have_pinned_space = 1;
-					goto commit_trans;
-				}
-			}
-
-			goto again;
-		}
-
-		/*
-		 * If we don't have enough pinned space to deal with this
-		 * allocation, and no removed chunk in current transaction,
-		 * don't bother committing the transaction.
-		 */
-		have_pinned_space = __percpu_counter_compare(
-			&data_sinfo->total_bytes_pinned,
-			used + bytes - data_sinfo->total_bytes,
-			BTRFS_TOTAL_BYTES_PINNED_BATCH);
-		spin_unlock(&data_sinfo->lock);
-
-		/* commit the current transaction and try again */
-commit_trans:
-		if (need_commit) {
-			need_commit--;
-
-			if (need_commit > 0) {
-				btrfs_start_delalloc_roots(fs_info, -1);
-				btrfs_wait_ordered_roots(fs_info, U64_MAX, 0,
-							 (u64)-1);
-			}
-
-			trans = btrfs_join_transaction(root);
-			if (IS_ERR(trans))
-				return PTR_ERR(trans);
-			if (have_pinned_space >= 0 ||
-			    test_bit(BTRFS_TRANS_HAVE_FREE_BGS,
-				     &trans->transaction->flags) ||
-			    need_commit > 0) {
-				ret = btrfs_commit_transaction(trans);
-				if (ret)
-					return ret;
-				/*
-				 * The cleaner kthread might still be doing iput
-				 * operations. Wait for it to finish so that
-				 * more space is released.
-				 */
-				mutex_lock(&fs_info->cleaner_delayed_iput_mutex);
-				mutex_unlock(&fs_info->cleaner_delayed_iput_mutex);
-				goto again;
-			} else {
-				btrfs_end_transaction(trans);
-			}
-		}
-
-		trace_btrfs_space_reservation(fs_info,
-					      "space_info:enospc",
-					      data_sinfo->flags, bytes, 1);
-		return -ENOSPC;
-	}
-	data_sinfo->bytes_may_use += bytes;
-	trace_btrfs_space_reservation(fs_info, "space_info",
-				      data_sinfo->flags, bytes, 1);
-	spin_unlock(&data_sinfo->lock);
-
-	return 0;
-}
-
-int btrfs_check_data_free_space(struct inode *inode,
-			struct extent_changeset **reserved, u64 start, u64 len)
-{
-	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
-	int ret;
-
-	/* align the range */
-	len = round_up(start + len, fs_info->sectorsize) -
-	      round_down(start, fs_info->sectorsize);
-	start = round_down(start, fs_info->sectorsize);
-
-	ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode), len);
-	if (ret < 0)
-		return ret;
-
-	/* Use new btrfs_qgroup_reserve_data to reserve precious data space. */
-	ret = btrfs_qgroup_reserve_data(inode, reserved, start, len);
-	if (ret < 0)
-		btrfs_free_reserved_data_space_noquota(inode, start, len);
-	else
-		ret = 0;
-	return ret;
-}
-
-/*
- * Called if we need to clear a data reservation for this inode
- * Normally in a error case.
- *
- * This one will *NOT* use accurate qgroup reserved space API, just for case
- * which we can't sleep and is sure it won't affect qgroup reserved space.
- * Like clear_bit_hook().
- */
-void btrfs_free_reserved_data_space_noquota(struct inode *inode, u64 start,
-					    u64 len)
-{
-	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
-	struct btrfs_space_info *data_sinfo;
-
-	/* Make sure the range is aligned to sectorsize */
-	len = round_up(start + len, fs_info->sectorsize) -
-	      round_down(start, fs_info->sectorsize);
-	start = round_down(start, fs_info->sectorsize);
-
-	data_sinfo = fs_info->data_sinfo;
-	spin_lock(&data_sinfo->lock);
-	if (WARN_ON(data_sinfo->bytes_may_use < len))
-		data_sinfo->bytes_may_use = 0;
-	else
-		data_sinfo->bytes_may_use -= len;
-	trace_btrfs_space_reservation(fs_info, "space_info",
-				      data_sinfo->flags, len, 0);
-	spin_unlock(&data_sinfo->lock);
-}
-
-/*
- * Called if we need to clear a data reservation for this inode
- * Normally in a error case.
- *
- * This one will handle the per-inode data rsv map for accurate reserved
- * space framework.
- */
-void btrfs_free_reserved_data_space(struct inode *inode,
-			struct extent_changeset *reserved, u64 start, u64 len)
-{
-	struct btrfs_root *root = BTRFS_I(inode)->root;
-
-	/* Make sure the range is aligned to sectorsize */
-	len = round_up(start + len, root->fs_info->sectorsize) -
-	      round_down(start, root->fs_info->sectorsize);
-	start = round_down(start, root->fs_info->sectorsize);
-
-	btrfs_free_reserved_data_space_noquota(inode, start, len);
-	btrfs_qgroup_free_data(inode, reserved, start, len);
-}
-
-static void force_metadata_allocation(struct btrfs_fs_info *info)
-{
-	struct list_head *head = &info->space_info;
-	struct btrfs_space_info *found;
-
-	rcu_read_lock();
-	list_for_each_entry_rcu(found, head, list) {
-		if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
-			found->force_alloc = CHUNK_ALLOC_FORCE;
-	}
-	rcu_read_unlock();
-}
-
-static inline u64 calc_global_rsv_need_space(struct btrfs_block_rsv *global)
-{
-	return (global->size << 1);
-}
-
-static int should_alloc_chunk(struct btrfs_fs_info *fs_info,
-			      struct btrfs_space_info *sinfo, int force)
-{
-	struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
-	u64 bytes_used = btrfs_space_info_used(sinfo, false);
-	u64 thresh;
-
-	if (force == CHUNK_ALLOC_FORCE)
-		return 1;
-
-	/*
-	 * We need to take into account the global rsv because for all intents
-	 * and purposes it's used space.  Don't worry about locking the
-	 * global_rsv, it doesn't change except when the transaction commits.
-	 */
-	if (sinfo->flags & BTRFS_BLOCK_GROUP_METADATA)
-		bytes_used += calc_global_rsv_need_space(global_rsv);
-
-	/*
-	 * in limited mode, we want to have some free space up to
-	 * about 1% of the FS size.
-	 */
-	if (force == CHUNK_ALLOC_LIMITED) {
-		thresh = btrfs_super_total_bytes(fs_info->super_copy);
-		thresh = max_t(u64, SZ_64M, div_factor_fine(thresh, 1));
-
-		if (sinfo->total_bytes - bytes_used < thresh)
-			return 1;
-	}
-
-	if (bytes_used + SZ_2M < div_factor(sinfo->total_bytes, 8))
-		return 0;
-	return 1;
-}
-
-static u64 get_profile_num_devs(struct btrfs_fs_info *fs_info, u64 type)
-{
-	u64 num_dev;
-
-	if (type & (BTRFS_BLOCK_GROUP_RAID10 |
-		    BTRFS_BLOCK_GROUP_RAID0 |
-		    BTRFS_BLOCK_GROUP_RAID5 |
-		    BTRFS_BLOCK_GROUP_RAID6))
-		num_dev = fs_info->fs_devices->rw_devices;
-	else if (type & BTRFS_BLOCK_GROUP_RAID1)
-		num_dev = 2;
-	else
-		num_dev = 1;	/* DUP or single */
-
-	return num_dev;
-}
-
-/*
- * If @is_allocation is true, reserve space in the system space info necessary
- * for allocating a chunk, otherwise if it's false, reserve space necessary for
- * removing a chunk.
- */
-void check_system_chunk(struct btrfs_trans_handle *trans, u64 type)
-{
-	struct btrfs_fs_info *fs_info = trans->fs_info;
-	struct btrfs_space_info *info;
-	u64 left;
-	u64 thresh;
-	int ret = 0;
-	u64 num_devs;
-
-	/*
-	 * Needed because we can end up allocating a system chunk and for an
-	 * atomic and race free space reservation in the chunk block reserve.
-	 */
-	lockdep_assert_held(&fs_info->chunk_mutex);
-
-	info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
-	spin_lock(&info->lock);
-	left = info->total_bytes - btrfs_space_info_used(info, true);
-	spin_unlock(&info->lock);
-
-	num_devs = get_profile_num_devs(fs_info, type);
-
-	/* num_devs device items to update and 1 chunk item to add or remove */
-	thresh = btrfs_calc_trunc_metadata_size(fs_info, num_devs) +
-		btrfs_calc_trans_metadata_size(fs_info, 1);
-
-	if (left < thresh && btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
-		btrfs_info(fs_info, "left=%llu, need=%llu, flags=%llu",
-			   left, thresh, type);
-		dump_space_info(fs_info, info, 0, 0);
-	}
-
-	if (left < thresh) {
-		u64 flags = btrfs_system_alloc_profile(fs_info);
-
-		/*
-		 * Ignore failure to create system chunk. We might end up not
-		 * needing it, as we might not need to COW all nodes/leafs from
-		 * the paths we visit in the chunk tree (they were already COWed
-		 * or created in the current transaction for example).
-		 */
-		ret = btrfs_alloc_chunk(trans, flags);
-	}
-
-	if (!ret) {
-		ret = btrfs_block_rsv_add(fs_info->chunk_root,
-					  &fs_info->chunk_block_rsv,
-					  thresh, BTRFS_RESERVE_NO_FLUSH);
-		if (!ret)
-			trans->chunk_bytes_reserved += thresh;
-	}
-}
-
-/*
- * If force is CHUNK_ALLOC_FORCE:
- *    - return 1 if it successfully allocates a chunk,
- *    - return errors including -ENOSPC otherwise.
- * If force is NOT CHUNK_ALLOC_FORCE:
- *    - return 0 if it doesn't need to allocate a new chunk,
- *    - return 1 if it successfully allocates a chunk,
- *    - return errors including -ENOSPC otherwise.
- */
-static int do_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags,
-			  int force)
-{
-	struct btrfs_fs_info *fs_info = trans->fs_info;
-	struct btrfs_space_info *space_info;
-	bool wait_for_alloc = false;
-	bool should_alloc = false;
-	int ret = 0;
-
-	/* Don't re-enter if we're already allocating a chunk */
-	if (trans->allocating_chunk)
-		return -ENOSPC;
-
-	space_info = __find_space_info(fs_info, flags);
-	ASSERT(space_info);
-
-	do {
-		spin_lock(&space_info->lock);
-		if (force < space_info->force_alloc)
-			force = space_info->force_alloc;
-		should_alloc = should_alloc_chunk(fs_info, space_info, force);
-		if (space_info->full) {
-			/* No more free physical space */
-			if (should_alloc)
-				ret = -ENOSPC;
-			else
-				ret = 0;
-			spin_unlock(&space_info->lock);
-			return ret;
-		} else if (!should_alloc) {
-			spin_unlock(&space_info->lock);
-			return 0;
-		} else if (space_info->chunk_alloc) {
-			/*
-			 * Someone is already allocating, so we need to block
-			 * until this someone is finished and then loop to
-			 * recheck if we should continue with our allocation
-			 * attempt.
-			 */
-			wait_for_alloc = true;
-			spin_unlock(&space_info->lock);
-			mutex_lock(&fs_info->chunk_mutex);
-			mutex_unlock(&fs_info->chunk_mutex);
-		} else {
-			/* Proceed with allocation */
-			space_info->chunk_alloc = 1;
-			wait_for_alloc = false;
-			spin_unlock(&space_info->lock);
-		}
-
-		cond_resched();
-	} while (wait_for_alloc);
-
-	mutex_lock(&fs_info->chunk_mutex);
-	trans->allocating_chunk = true;
-
-	/*
-	 * If we have mixed data/metadata chunks we want to make sure we keep
-	 * allocating mixed chunks instead of individual chunks.
-	 */
-	if (btrfs_mixed_space_info(space_info))
-		flags |= (BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA);
-
-	/*
-	 * if we're doing a data chunk, go ahead and make sure that
-	 * we keep a reasonable number of metadata chunks allocated in the
-	 * FS as well.
-	 */
-	if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) {
-		fs_info->data_chunk_allocations++;
-		if (!(fs_info->data_chunk_allocations %
-		      fs_info->metadata_ratio))
-			force_metadata_allocation(fs_info);
-	}
-
-	/*
-	 * Check if we have enough space in SYSTEM chunk because we may need
-	 * to update devices.
-	 */
-	check_system_chunk(trans, flags);
-
-	ret = btrfs_alloc_chunk(trans, flags);
-	trans->allocating_chunk = false;
-
-	spin_lock(&space_info->lock);
-	if (ret < 0) {
-		if (ret == -ENOSPC)
-			space_info->full = 1;
-		else
-			goto out;
-	} else {
-		ret = 1;
-		space_info->max_extent_size = 0;
-	}
-
-	space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
-out:
-	space_info->chunk_alloc = 0;
-	spin_unlock(&space_info->lock);
-	mutex_unlock(&fs_info->chunk_mutex);
-	/*
-	 * When we allocate a new chunk we reserve space in the chunk block
-	 * reserve to make sure we can COW nodes/leafs in the chunk tree or
-	 * add new nodes/leafs to it if we end up needing to do it when
-	 * inserting the chunk item and updating device items as part of the
-	 * second phase of chunk allocation, performed by
-	 * btrfs_finish_chunk_alloc(). So make sure we don't accumulate a
-	 * large number of new block groups to create in our transaction
-	 * handle's new_bgs list to avoid exhausting the chunk block reserve
-	 * in extreme cases - like having a single transaction create many new
-	 * block groups when starting to write out the free space caches of all
-	 * the block groups that were made dirty during the lifetime of the
-	 * transaction.
-	 */
-	if (trans->chunk_bytes_reserved >= (u64)SZ_2M)
-		btrfs_create_pending_block_groups(trans);
-
-	return ret;
-}
-
-static int can_overcommit(struct btrfs_fs_info *fs_info,
-			  struct btrfs_space_info *space_info, u64 bytes,
-			  enum btrfs_reserve_flush_enum flush,
-			  bool system_chunk)
-{
-	struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
-	u64 profile;
-	u64 space_size;
-	u64 avail;
-	u64 used;
-	int factor;
-
-	/* Don't overcommit when in mixed mode. */
-	if (space_info->flags & BTRFS_BLOCK_GROUP_DATA)
-		return 0;
-
-	if (system_chunk)
-		profile = btrfs_system_alloc_profile(fs_info);
-	else
-		profile = btrfs_metadata_alloc_profile(fs_info);
-
-	used = btrfs_space_info_used(space_info, false);
-
-	/*
-	 * We only want to allow over committing if we have lots of actual space
-	 * free, but if we don't have enough space to handle the global reserve
-	 * space then we could end up having a real enospc problem when trying
-	 * to allocate a chunk or some other such important allocation.
-	 */
-	spin_lock(&global_rsv->lock);
-	space_size = calc_global_rsv_need_space(global_rsv);
-	spin_unlock(&global_rsv->lock);
-	if (used + space_size >= space_info->total_bytes)
-		return 0;
-
-	used += space_info->bytes_may_use;
-
-	avail = atomic64_read(&fs_info->free_chunk_space);
-
-	/*
-	 * If we have dup, raid1 or raid10 then only half of the free
-	 * space is actually useable.  For raid56, the space info used
-	 * doesn't include the parity drive, so we don't have to
-	 * change the math
-	 */
-	factor = btrfs_bg_type_to_factor(profile);
-	avail = div_u64(avail, factor);
-
-	/*
-	 * If we aren't flushing all things, let us overcommit up to
-	 * 1/2th of the space. If we can flush, don't let us overcommit
-	 * too much, let it overcommit up to 1/8 of the space.
-	 */
-	if (flush == BTRFS_RESERVE_FLUSH_ALL)
-		avail >>= 3;
-	else
-		avail >>= 1;
-
-	if (used + bytes < space_info->total_bytes + avail)
-		return 1;
-	return 0;
-}
-
-static void btrfs_writeback_inodes_sb_nr(struct btrfs_fs_info *fs_info,
-					 unsigned long nr_pages, int nr_items)
-{
-	struct super_block *sb = fs_info->sb;
-
-	if (down_read_trylock(&sb->s_umount)) {
-		writeback_inodes_sb_nr(sb, nr_pages, WB_REASON_FS_FREE_SPACE);
-		up_read(&sb->s_umount);
-	} else {
-		/*
-		 * We needn't worry the filesystem going from r/w to r/o though
-		 * we don't acquire ->s_umount mutex, because the filesystem
-		 * should guarantee the delalloc inodes list be empty after
-		 * the filesystem is readonly(all dirty pages are written to
-		 * the disk).
-		 */
-		btrfs_start_delalloc_roots(fs_info, nr_items);
-		if (!current->journal_info)
-			btrfs_wait_ordered_roots(fs_info, nr_items, 0, (u64)-1);
-	}
-}
-
-static inline u64 calc_reclaim_items_nr(struct btrfs_fs_info *fs_info,
-					u64 to_reclaim)
-{
-	u64 bytes;
-	u64 nr;
-
-	bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
-	nr = div64_u64(to_reclaim, bytes);
-	if (!nr)
-		nr = 1;
-	return nr;
-}
-
-#define EXTENT_SIZE_PER_ITEM	SZ_256K
-
-/*
- * shrink metadata reservation for delalloc
- */
-static void shrink_delalloc(struct btrfs_fs_info *fs_info, u64 to_reclaim,
-			    u64 orig, bool wait_ordered)
-{
-	struct btrfs_space_info *space_info;
-	struct btrfs_trans_handle *trans;
-	u64 delalloc_bytes;
-	u64 max_reclaim;
-	u64 items;
-	long time_left;
-	unsigned long nr_pages;
-	int loops;
-
-	/* Calc the number of the pages we need flush for space reservation */
-	items = calc_reclaim_items_nr(fs_info, to_reclaim);
-	to_reclaim = items * EXTENT_SIZE_PER_ITEM;
-
-	trans = (struct btrfs_trans_handle *)current->journal_info;
-	space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
-
-	delalloc_bytes = percpu_counter_sum_positive(
-						&fs_info->delalloc_bytes);
-	if (delalloc_bytes == 0) {
-		if (trans)
-			return;
-		if (wait_ordered)
-			btrfs_wait_ordered_roots(fs_info, items, 0, (u64)-1);
-		return;
-	}
-
-	loops = 0;
-	while (delalloc_bytes && loops < 3) {
-		max_reclaim = min(delalloc_bytes, to_reclaim);
-		nr_pages = max_reclaim >> PAGE_SHIFT;
-		btrfs_writeback_inodes_sb_nr(fs_info, nr_pages, items);
-		/*
-		 * We need to wait for the async pages to actually start before
-		 * we do anything.
-		 */
-		max_reclaim = atomic_read(&fs_info->async_delalloc_pages);
-		if (!max_reclaim)
-			goto skip_async;
-
-		if (max_reclaim <= nr_pages)
-			max_reclaim = 0;
-		else
-			max_reclaim -= nr_pages;
-
-		wait_event(fs_info->async_submit_wait,
-			   atomic_read(&fs_info->async_delalloc_pages) <=
-			   (int)max_reclaim);
-skip_async:
-		spin_lock(&space_info->lock);
-		if (list_empty(&space_info->tickets) &&
-		    list_empty(&space_info->priority_tickets)) {
-			spin_unlock(&space_info->lock);
-			break;
-		}
-		spin_unlock(&space_info->lock);
-
-		loops++;
-		if (wait_ordered && !trans) {
-			btrfs_wait_ordered_roots(fs_info, items, 0, (u64)-1);
-		} else {
-			time_left = schedule_timeout_killable(1);
-			if (time_left)
-				break;
-		}
-		delalloc_bytes = percpu_counter_sum_positive(
-						&fs_info->delalloc_bytes);
-	}
-}
-
-struct reserve_ticket {
-	u64 bytes;
-	int error;
-	struct list_head list;
-	wait_queue_head_t wait;
-};
-
-/**
- * maybe_commit_transaction - possibly commit the transaction if its ok to
- * @root - the root we're allocating for
- * @bytes - the number of bytes we want to reserve
- * @force - force the commit
- *
- * This will check to make sure that committing the transaction will actually
- * get us somewhere and then commit the transaction if it does.  Otherwise it
- * will return -ENOSPC.
- */
-static int may_commit_transaction(struct btrfs_fs_info *fs_info,
-				  struct btrfs_space_info *space_info)
-{
-	struct reserve_ticket *ticket = NULL;
-	struct btrfs_block_rsv *delayed_rsv = &fs_info->delayed_block_rsv;
-	struct btrfs_trans_handle *trans;
-	u64 bytes;
-
-	trans = (struct btrfs_trans_handle *)current->journal_info;
-	if (trans)
-		return -EAGAIN;
-
-	spin_lock(&space_info->lock);
-	if (!list_empty(&space_info->priority_tickets))
-		ticket = list_first_entry(&space_info->priority_tickets,
-					  struct reserve_ticket, list);
-	else if (!list_empty(&space_info->tickets))
-		ticket = list_first_entry(&space_info->tickets,
-					  struct reserve_ticket, list);
-	bytes = (ticket) ? ticket->bytes : 0;
-	spin_unlock(&space_info->lock);
-
-	if (!bytes)
-		return 0;
-
-	/* See if there is enough pinned space to make this reservation */
-	if (__percpu_counter_compare(&space_info->total_bytes_pinned,
-				   bytes,
-				   BTRFS_TOTAL_BYTES_PINNED_BATCH) >= 0)
-		goto commit;
-
-	/*
-	 * See if there is some space in the delayed insertion reservation for
-	 * this reservation.
-	 */
-	if (space_info != delayed_rsv->space_info)
-		return -ENOSPC;
-
-	spin_lock(&delayed_rsv->lock);
-	if (delayed_rsv->size > bytes)
-		bytes = 0;
-	else
-		bytes -= delayed_rsv->size;
-	spin_unlock(&delayed_rsv->lock);
-
-	if (__percpu_counter_compare(&space_info->total_bytes_pinned,
-				   bytes,
-				   BTRFS_TOTAL_BYTES_PINNED_BATCH) < 0) {
-		return -ENOSPC;
-	}
-
-commit:
-	trans = btrfs_join_transaction(fs_info->extent_root);
-	if (IS_ERR(trans))
-		return -ENOSPC;
-
-	return btrfs_commit_transaction(trans);
-}
-
-/*
- * Try to flush some data based on policy set by @state. This is only advisory
- * and may fail for various reasons. The caller is supposed to examine the
- * state of @space_info to detect the outcome.
- */
-static void flush_space(struct btrfs_fs_info *fs_info,
-		       struct btrfs_space_info *space_info, u64 num_bytes,
-		       int state)
-{
-	struct btrfs_root *root = fs_info->extent_root;
-	struct btrfs_trans_handle *trans;
-	int nr;
-	int ret = 0;
-
-	switch (state) {
-	case FLUSH_DELAYED_ITEMS_NR:
-	case FLUSH_DELAYED_ITEMS:
-		if (state == FLUSH_DELAYED_ITEMS_NR)
-			nr = calc_reclaim_items_nr(fs_info, num_bytes) * 2;
-		else
-			nr = -1;
-
-		trans = btrfs_join_transaction(root);
-		if (IS_ERR(trans)) {
-			ret = PTR_ERR(trans);
-			break;
-		}
-		ret = btrfs_run_delayed_items_nr(trans, nr);
-		btrfs_end_transaction(trans);
-		break;
-	case FLUSH_DELALLOC:
-	case FLUSH_DELALLOC_WAIT:
-		shrink_delalloc(fs_info, num_bytes * 2, num_bytes,
-				state == FLUSH_DELALLOC_WAIT);
-		break;
-	case ALLOC_CHUNK:
-		trans = btrfs_join_transaction(root);
-		if (IS_ERR(trans)) {
-			ret = PTR_ERR(trans);
-			break;
-		}
-		ret = do_chunk_alloc(trans,
-				     btrfs_metadata_alloc_profile(fs_info),
-				     CHUNK_ALLOC_NO_FORCE);
-		btrfs_end_transaction(trans);
-		if (ret > 0 || ret == -ENOSPC)
-			ret = 0;
-		break;
-	case COMMIT_TRANS:
-		ret = may_commit_transaction(fs_info, space_info);
-		break;
-	default:
-		ret = -ENOSPC;
-		break;
-	}
-
-	trace_btrfs_flush_space(fs_info, space_info->flags, num_bytes, state,
-				ret);
-	return;
-}
-
-static inline u64
-btrfs_calc_reclaim_metadata_size(struct btrfs_fs_info *fs_info,
-				 struct btrfs_space_info *space_info,
-				 bool system_chunk)
-{
-	struct reserve_ticket *ticket;
-	u64 used;
-	u64 expected;
-	u64 to_reclaim = 0;
-
-	list_for_each_entry(ticket, &space_info->tickets, list)
-		to_reclaim += ticket->bytes;
-	list_for_each_entry(ticket, &space_info->priority_tickets, list)
-		to_reclaim += ticket->bytes;
-	if (to_reclaim)
-		return to_reclaim;
-
-	to_reclaim = min_t(u64, num_online_cpus() * SZ_1M, SZ_16M);
-	if (can_overcommit(fs_info, space_info, to_reclaim,
-			   BTRFS_RESERVE_FLUSH_ALL, system_chunk))
-		return 0;
-
-	used = btrfs_space_info_used(space_info, true);
-
-	if (can_overcommit(fs_info, space_info, SZ_1M,
-			   BTRFS_RESERVE_FLUSH_ALL, system_chunk))
-		expected = div_factor_fine(space_info->total_bytes, 95);
-	else
-		expected = div_factor_fine(space_info->total_bytes, 90);
-
-	if (used > expected)
-		to_reclaim = used - expected;
-	else
-		to_reclaim = 0;
-	to_reclaim = min(to_reclaim, space_info->bytes_may_use +
-				     space_info->bytes_reserved);
-	return to_reclaim;
-}
-
-static inline int need_do_async_reclaim(struct btrfs_fs_info *fs_info,
-					struct btrfs_space_info *space_info,
-					u64 used, bool system_chunk)
-{
-	u64 thresh = div_factor_fine(space_info->total_bytes, 98);
-
-	/* If we're just plain full then async reclaim just slows us down. */
-	if ((space_info->bytes_used + space_info->bytes_reserved) >= thresh)
-		return 0;
-
-	if (!btrfs_calc_reclaim_metadata_size(fs_info, space_info,
-					      system_chunk))
-		return 0;
-
-	return (used >= thresh && !btrfs_fs_closing(fs_info) &&
-		!test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state));
-}
-
-static void wake_all_tickets(struct list_head *head)
-{
-	struct reserve_ticket *ticket;
-
-	while (!list_empty(head)) {
-		ticket = list_first_entry(head, struct reserve_ticket, list);
-		list_del_init(&ticket->list);
-		ticket->error = -ENOSPC;
-		wake_up(&ticket->wait);
-	}
-}
-
-/*
- * This is for normal flushers, we can wait all goddamned day if we want to.  We
- * will loop and continuously try to flush as long as we are making progress.
- * We count progress as clearing off tickets each time we have to loop.
- */
-static void btrfs_async_reclaim_metadata_space(struct work_struct *work)
-{
-	struct btrfs_fs_info *fs_info;
-	struct btrfs_space_info *space_info;
-	u64 to_reclaim;
-	int flush_state;
-	int commit_cycles = 0;
-	u64 last_tickets_id;
-
-	fs_info = container_of(work, struct btrfs_fs_info, async_reclaim_work);
-	space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
-
-	spin_lock(&space_info->lock);
-	to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, space_info,
-						      false);
-	if (!to_reclaim) {
-		space_info->flush = 0;
-		spin_unlock(&space_info->lock);
-		return;
-	}
-	last_tickets_id = space_info->tickets_id;
-	spin_unlock(&space_info->lock);
-
-	flush_state = FLUSH_DELAYED_ITEMS_NR;
-	do {
-		flush_space(fs_info, space_info, to_reclaim, flush_state);
-		spin_lock(&space_info->lock);
-		if (list_empty(&space_info->tickets)) {
-			space_info->flush = 0;
-			spin_unlock(&space_info->lock);
-			return;
-		}
-		to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info,
-							      space_info,
-							      false);
-		if (last_tickets_id == space_info->tickets_id) {
-			flush_state++;
-		} else {
-			last_tickets_id = space_info->tickets_id;
-			flush_state = FLUSH_DELAYED_ITEMS_NR;
-			if (commit_cycles)
-				commit_cycles--;
-		}
-
-		if (flush_state > COMMIT_TRANS) {
-			commit_cycles++;
-			if (commit_cycles > 2) {
-				wake_all_tickets(&space_info->tickets);
-				space_info->flush = 0;
-			} else {
-				flush_state = FLUSH_DELAYED_ITEMS_NR;
-			}
-		}
-		spin_unlock(&space_info->lock);
-	} while (flush_state <= COMMIT_TRANS);
-}
-
-void btrfs_init_async_reclaim_work(struct work_struct *work)
-{
-	INIT_WORK(work, btrfs_async_reclaim_metadata_space);
-}
-
-static void priority_reclaim_metadata_space(struct btrfs_fs_info *fs_info,
-					    struct btrfs_space_info *space_info,
-					    struct reserve_ticket *ticket)
-{
-	u64 to_reclaim;
-	int flush_state = FLUSH_DELAYED_ITEMS_NR;
-
-	spin_lock(&space_info->lock);
-	to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, space_info,
-						      false);
-	if (!to_reclaim) {
-		spin_unlock(&space_info->lock);
-		return;
-	}
-	spin_unlock(&space_info->lock);
-
-	do {
-		flush_space(fs_info, space_info, to_reclaim, flush_state);
-		flush_state++;
-		spin_lock(&space_info->lock);
-		if (ticket->bytes == 0) {
-			spin_unlock(&space_info->lock);
-			return;
-		}
-		spin_unlock(&space_info->lock);
-
-		/*
-		 * Priority flushers can't wait on delalloc without
-		 * deadlocking.
-		 */
-		if (flush_state == FLUSH_DELALLOC ||
-		    flush_state == FLUSH_DELALLOC_WAIT)
-			flush_state = ALLOC_CHUNK;
-	} while (flush_state < COMMIT_TRANS);
-}
-
-static int wait_reserve_ticket(struct btrfs_fs_info *fs_info,
-			       struct btrfs_space_info *space_info,
-			       struct reserve_ticket *ticket, u64 orig_bytes)
-
-{
-	DEFINE_WAIT(wait);
-	int ret = 0;
-
-	spin_lock(&space_info->lock);
-	while (ticket->bytes > 0 && ticket->error == 0) {
-		ret = prepare_to_wait_event(&ticket->wait, &wait, TASK_KILLABLE);
-		if (ret) {
-			ret = -EINTR;
-			break;
-		}
-		spin_unlock(&space_info->lock);
-
-		schedule();
-
-		finish_wait(&ticket->wait, &wait);
-		spin_lock(&space_info->lock);
-	}
-	if (!ret)
-		ret = ticket->error;
-	if (!list_empty(&ticket->list))
-		list_del_init(&ticket->list);
-	if (ticket->bytes && ticket->bytes < orig_bytes) {
-		u64 num_bytes = orig_bytes - ticket->bytes;
-		space_info->bytes_may_use -= num_bytes;
-		trace_btrfs_space_reservation(fs_info, "space_info",
-					      space_info->flags, num_bytes, 0);
-	}
-	spin_unlock(&space_info->lock);
-
-	return ret;
-}
-
-/**
- * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space
- * @root - the root we're allocating for
- * @space_info - the space info we want to allocate from
- * @orig_bytes - the number of bytes we want
- * @flush - whether or not we can flush to make our reservation
- *
- * This will reserve orig_bytes number of bytes from the space info associated
- * with the block_rsv.  If there is not enough space it will make an attempt to
- * flush out space to make room.  It will do this by flushing delalloc if
- * possible or committing the transaction.  If flush is 0 then no attempts to
- * regain reservations will be made and this will fail if there is not enough
- * space already.
- */
-static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info,
-				    struct btrfs_space_info *space_info,
-				    u64 orig_bytes,
-				    enum btrfs_reserve_flush_enum flush,
-				    bool system_chunk)
-{
-	struct reserve_ticket ticket;
-	u64 used;
-	int ret = 0;
-
-	ASSERT(orig_bytes);
-	ASSERT(!current->journal_info || flush != BTRFS_RESERVE_FLUSH_ALL);
-
-	spin_lock(&space_info->lock);
-	ret = -ENOSPC;
-	used = btrfs_space_info_used(space_info, true);
-
-	/*
-	 * If we have enough space then hooray, make our reservation and carry
-	 * on.  If not see if we can overcommit, and if we can, hooray carry on.
-	 * If not things get more complicated.
-	 */
-	if (used + orig_bytes <= space_info->total_bytes) {
-		space_info->bytes_may_use += orig_bytes;
-		trace_btrfs_space_reservation(fs_info, "space_info",
-					      space_info->flags, orig_bytes, 1);
-		ret = 0;
-	} else if (can_overcommit(fs_info, space_info, orig_bytes, flush,
-				  system_chunk)) {
-		space_info->bytes_may_use += orig_bytes;
-		trace_btrfs_space_reservation(fs_info, "space_info",
-					      space_info->flags, orig_bytes, 1);
-		ret = 0;
-	}
-
-	/*
-	 * If we couldn't make a reservation then setup our reservation ticket
-	 * and kick the async worker if it's not already running.
-	 *
-	 * If we are a priority flusher then we just need to add our ticket to
-	 * the list and we will do our own flushing further down.
-	 */
-	if (ret && flush != BTRFS_RESERVE_NO_FLUSH) {
-		ticket.bytes = orig_bytes;
-		ticket.error = 0;
-		init_waitqueue_head(&ticket.wait);
-		if (flush == BTRFS_RESERVE_FLUSH_ALL) {
-			list_add_tail(&ticket.list, &space_info->tickets);
-			if (!space_info->flush) {
-				space_info->flush = 1;
-				trace_btrfs_trigger_flush(fs_info,
-							  space_info->flags,
-							  orig_bytes, flush,
-							  "enospc");
-				queue_work(system_unbound_wq,
-					   &fs_info->async_reclaim_work);
-			}
-		} else {
-			list_add_tail(&ticket.list,
-				      &space_info->priority_tickets);
-		}
-	} else if (!ret && space_info->flags & BTRFS_BLOCK_GROUP_METADATA) {
-		used += orig_bytes;
-		/*
-		 * We will do the space reservation dance during log replay,
-		 * which means we won't have fs_info->fs_root set, so don't do
-		 * the async reclaim as we will panic.
-		 */
-		if (!test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags) &&
-		    need_do_async_reclaim(fs_info, space_info,
-					  used, system_chunk) &&
-		    !work_busy(&fs_info->async_reclaim_work)) {
-			trace_btrfs_trigger_flush(fs_info, space_info->flags,
-						  orig_bytes, flush, "preempt");
-			queue_work(system_unbound_wq,
-				   &fs_info->async_reclaim_work);
-		}
-	}
-	spin_unlock(&space_info->lock);
-	if (!ret || flush == BTRFS_RESERVE_NO_FLUSH)
-		return ret;
-
-	if (flush == BTRFS_RESERVE_FLUSH_ALL)
-		return wait_reserve_ticket(fs_info, space_info, &ticket,
-					   orig_bytes);
-
-	ret = 0;
-	priority_reclaim_metadata_space(fs_info, space_info, &ticket);
-	spin_lock(&space_info->lock);
-	if (ticket.bytes) {
-		if (ticket.bytes < orig_bytes) {
-			u64 num_bytes = orig_bytes - ticket.bytes;
-			space_info->bytes_may_use -= num_bytes;
-			trace_btrfs_space_reservation(fs_info, "space_info",
-						      space_info->flags,
-						      num_bytes, 0);
-
-		}
-		list_del_init(&ticket.list);
-		ret = -ENOSPC;
-	}
-	spin_unlock(&space_info->lock);
-	ASSERT(list_empty(&ticket.list));
-	return ret;
-}
-
-/**
- * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space
- * @root - the root we're allocating for
- * @block_rsv - the block_rsv we're allocating for
- * @orig_bytes - the number of bytes we want
- * @flush - whether or not we can flush to make our reservation
- *
- * This will reserve orgi_bytes number of bytes from the space info associated
- * with the block_rsv.  If there is not enough space it will make an attempt to
- * flush out space to make room.  It will do this by flushing delalloc if
- * possible or committing the transaction.  If flush is 0 then no attempts to
- * regain reservations will be made and this will fail if there is not enough
- * space already.
- */
-static int reserve_metadata_bytes(struct btrfs_root *root,
-				  struct btrfs_block_rsv *block_rsv,
-				  u64 orig_bytes,
-				  enum btrfs_reserve_flush_enum flush)
-{
-	struct btrfs_fs_info *fs_info = root->fs_info;
-	struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
-	int ret;
-	bool system_chunk = (root == fs_info->chunk_root);
-
-	ret = __reserve_metadata_bytes(fs_info, block_rsv->space_info,
-				       orig_bytes, flush, system_chunk);
-	if (ret == -ENOSPC &&
-	    unlikely(root->orphan_cleanup_state == ORPHAN_CLEANUP_STARTED)) {
-		if (block_rsv != global_rsv &&
-		    !block_rsv_use_bytes(global_rsv, orig_bytes))
-			ret = 0;
-	}
-	if (ret == -ENOSPC) {
-		trace_btrfs_space_reservation(fs_info, "space_info:enospc",
-					      block_rsv->space_info->flags,
-					      orig_bytes, 1);
-
-		if (btrfs_test_opt(fs_info, ENOSPC_DEBUG))
-			dump_space_info(fs_info, block_rsv->space_info,
-					orig_bytes, 0);
-	}
-	return ret;
-}
-
-static struct btrfs_block_rsv *get_block_rsv(
-					const struct btrfs_trans_handle *trans,
-					const struct btrfs_root *root)
-{
-	struct btrfs_fs_info *fs_info = root->fs_info;
-	struct btrfs_block_rsv *block_rsv = NULL;
-
-	if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
-	    (root == fs_info->csum_root && trans->adding_csums) ||
-	    (root == fs_info->uuid_root))
-		block_rsv = trans->block_rsv;
-
-	if (!block_rsv)
-		block_rsv = root->block_rsv;
-
-	if (!block_rsv)
-		block_rsv = &fs_info->empty_block_rsv;
-
-	return block_rsv;
-}
-
-static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv,
-			       u64 num_bytes)
-{
-	int ret = -ENOSPC;
-	spin_lock(&block_rsv->lock);
-	if (block_rsv->reserved >= num_bytes) {
-		block_rsv->reserved -= num_bytes;
-		if (block_rsv->reserved < block_rsv->size)
-			block_rsv->full = 0;
-		ret = 0;
-	}
-	spin_unlock(&block_rsv->lock);
-	return ret;
-}
-
-static void block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
-				u64 num_bytes, int update_size)
-{
-	spin_lock(&block_rsv->lock);
-	block_rsv->reserved += num_bytes;
-	if (update_size)
-		block_rsv->size += num_bytes;
-	else if (block_rsv->reserved >= block_rsv->size)
-		block_rsv->full = 1;
-	spin_unlock(&block_rsv->lock);
-}
-
-int btrfs_cond_migrate_bytes(struct btrfs_fs_info *fs_info,
-			     struct btrfs_block_rsv *dest, u64 num_bytes,
-			     int min_factor)
-{
-	struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
-	u64 min_bytes;
-
-	if (global_rsv->space_info != dest->space_info)
-		return -ENOSPC;
-
-	spin_lock(&global_rsv->lock);
-	min_bytes = div_factor(global_rsv->size, min_factor);
-	if (global_rsv->reserved < min_bytes + num_bytes) {
-		spin_unlock(&global_rsv->lock);
-		return -ENOSPC;
-	}
-	global_rsv->reserved -= num_bytes;
-	if (global_rsv->reserved < global_rsv->size)
-		global_rsv->full = 0;
-	spin_unlock(&global_rsv->lock);
-
-	block_rsv_add_bytes(dest, num_bytes, 1);
-	return 0;
-}
-
-/*
- * This is for space we already have accounted in space_info->bytes_may_use, so
- * basically when we're returning space from block_rsv's.
- */
-static void space_info_add_old_bytes(struct btrfs_fs_info *fs_info,
-				     struct btrfs_space_info *space_info,
-				     u64 num_bytes)
-{
-	struct reserve_ticket *ticket;
-	struct list_head *head;
-	u64 used;
-	enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_NO_FLUSH;
-	bool check_overcommit = false;
-
-	spin_lock(&space_info->lock);
-	head = &space_info->priority_tickets;
-
-	/*
-	 * If we are over our limit then we need to check and see if we can
-	 * overcommit, and if we can't then we just need to free up our space
-	 * and not satisfy any requests.
-	 */
-	used = btrfs_space_info_used(space_info, true);
-	if (used - num_bytes >= space_info->total_bytes)
-		check_overcommit = true;
-again:
-	while (!list_empty(head) && num_bytes) {
-		ticket = list_first_entry(head, struct reserve_ticket,
-					  list);
-		/*
-		 * We use 0 bytes because this space is already reserved, so
-		 * adding the ticket space would be a double count.
-		 */
-		if (check_overcommit &&
-		    !can_overcommit(fs_info, space_info, 0, flush, false))
-			break;
-		if (num_bytes >= ticket->bytes) {
-			list_del_init(&ticket->list);
-			num_bytes -= ticket->bytes;
-			ticket->bytes = 0;
-			space_info->tickets_id++;
-			wake_up(&ticket->wait);
-		} else {
-			ticket->bytes -= num_bytes;
-			num_bytes = 0;
-		}
-	}
-
-	if (num_bytes && head == &space_info->priority_tickets) {
-		head = &space_info->tickets;
-		flush = BTRFS_RESERVE_FLUSH_ALL;
-		goto again;
-	}
-	space_info->bytes_may_use -= num_bytes;
-	trace_btrfs_space_reservation(fs_info, "space_info",
-				      space_info->flags, num_bytes, 0);
-	spin_unlock(&space_info->lock);
-}
-
-/*
- * This is for newly allocated space that isn't accounted in
- * space_info->bytes_may_use yet.  So if we allocate a chunk or unpin an extent
- * we use this helper.
- */
-static void space_info_add_new_bytes(struct btrfs_fs_info *fs_info,
-				     struct btrfs_space_info *space_info,
-				     u64 num_bytes)
-{
-	struct reserve_ticket *ticket;
-	struct list_head *head = &space_info->priority_tickets;
-
-again:
-	while (!list_empty(head) && num_bytes) {
-		ticket = list_first_entry(head, struct reserve_ticket,
-					  list);
-		if (num_bytes >= ticket->bytes) {
-			trace_btrfs_space_reservation(fs_info, "space_info",
-						      space_info->flags,
-						      ticket->bytes, 1);
-			list_del_init(&ticket->list);
-			num_bytes -= ticket->bytes;
-			space_info->bytes_may_use += ticket->bytes;
-			ticket->bytes = 0;
-			space_info->tickets_id++;
-			wake_up(&ticket->wait);
-		} else {
-			trace_btrfs_space_reservation(fs_info, "space_info",
-						      space_info->flags,
-						      num_bytes, 1);
-			space_info->bytes_may_use += num_bytes;
-			ticket->bytes -= num_bytes;
-			num_bytes = 0;
-		}
-	}
-
-	if (num_bytes && head == &space_info->priority_tickets) {
-		head = &space_info->tickets;
-		goto again;
-	}
-}
-
-static u64 block_rsv_release_bytes(struct btrfs_fs_info *fs_info,
-				    struct btrfs_block_rsv *block_rsv,
-				    struct btrfs_block_rsv *dest, u64 num_bytes,
-				    u64 *qgroup_to_release_ret)
-{
-	struct btrfs_space_info *space_info = block_rsv->space_info;
-	u64 qgroup_to_release = 0;
-	u64 ret;
-
-	spin_lock(&block_rsv->lock);
-	if (num_bytes == (u64)-1) {
-		num_bytes = block_rsv->size;
-		qgroup_to_release = block_rsv->qgroup_rsv_size;
-	}
-	block_rsv->size -= num_bytes;
-	if (block_rsv->reserved >= block_rsv->size) {
-		num_bytes = block_rsv->reserved - block_rsv->size;
-		block_rsv->reserved = block_rsv->size;
-		block_rsv->full = 1;
-	} else {
-		num_bytes = 0;
-	}
-	if (block_rsv->qgroup_rsv_reserved >= block_rsv->qgroup_rsv_size) {
-		qgroup_to_release = block_rsv->qgroup_rsv_reserved -
-				    block_rsv->qgroup_rsv_size;
-		block_rsv->qgroup_rsv_reserved = block_rsv->qgroup_rsv_size;
-	} else {
-		qgroup_to_release = 0;
-	}
-	spin_unlock(&block_rsv->lock);
-
-	ret = num_bytes;
-	if (num_bytes > 0) {
-		if (dest) {
-			spin_lock(&dest->lock);
-			if (!dest->full) {
-				u64 bytes_to_add;
-
-				bytes_to_add = dest->size - dest->reserved;
-				bytes_to_add = min(num_bytes, bytes_to_add);
-				dest->reserved += bytes_to_add;
-				if (dest->reserved >= dest->size)
-					dest->full = 1;
-				num_bytes -= bytes_to_add;
-			}
-			spin_unlock(&dest->lock);
-		}
-		if (num_bytes)
-			space_info_add_old_bytes(fs_info, space_info,
-						 num_bytes);
-	}
-	if (qgroup_to_release_ret)
-		*qgroup_to_release_ret = qgroup_to_release;
-	return ret;
-}
-
-int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src,
-			    struct btrfs_block_rsv *dst, u64 num_bytes,
-			    int update_size)
-{
-	int ret;
-
-	ret = block_rsv_use_bytes(src, num_bytes);
-	if (ret)
-		return ret;
-
-	block_rsv_add_bytes(dst, num_bytes, update_size);
-	return 0;
-}
-
-void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv, unsigned short type)
-{
-	memset(rsv, 0, sizeof(*rsv));
-	spin_lock_init(&rsv->lock);
-	rsv->type = type;
-}
-
-void btrfs_init_metadata_block_rsv(struct btrfs_fs_info *fs_info,
-				   struct btrfs_block_rsv *rsv,
-				   unsigned short type)
-{
-	btrfs_init_block_rsv(rsv, type);
-	rsv->space_info = __find_space_info(fs_info,
-					    BTRFS_BLOCK_GROUP_METADATA);
-}
-
-struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_fs_info *fs_info,
-					      unsigned short type)
-{
-	struct btrfs_block_rsv *block_rsv;
-
-	block_rsv = kmalloc(sizeof(*block_rsv), GFP_NOFS);
-	if (!block_rsv)
-		return NULL;
-
-	btrfs_init_metadata_block_rsv(fs_info, block_rsv, type);
-	return block_rsv;
-}
-
-void btrfs_free_block_rsv(struct btrfs_fs_info *fs_info,
-			  struct btrfs_block_rsv *rsv)
-{
-	if (!rsv)
-		return;
-	btrfs_block_rsv_release(fs_info, rsv, (u64)-1);
-	kfree(rsv);
-}
-
-int btrfs_block_rsv_add(struct btrfs_root *root,
-			struct btrfs_block_rsv *block_rsv, u64 num_bytes,
-			enum btrfs_reserve_flush_enum flush)
-{
-	int ret;
-
-	if (num_bytes == 0)
-		return 0;
-
-	ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush);
-	if (!ret) {
-		block_rsv_add_bytes(block_rsv, num_bytes, 1);
-		return 0;
-	}
-
-	return ret;
-}
-
-int btrfs_block_rsv_check(struct btrfs_block_rsv *block_rsv, int min_factor)
-{
-	u64 num_bytes = 0;
-	int ret = -ENOSPC;
-
-	if (!block_rsv)
-		return 0;
-
-	spin_lock(&block_rsv->lock);
-	num_bytes = div_factor(block_rsv->size, min_factor);
-	if (block_rsv->reserved >= num_bytes)
-		ret = 0;
-	spin_unlock(&block_rsv->lock);
-
-	return ret;
-}
-
-int btrfs_block_rsv_refill(struct btrfs_root *root,
-			   struct btrfs_block_rsv *block_rsv, u64 min_reserved,
-			   enum btrfs_reserve_flush_enum flush)
-{
-	u64 num_bytes = 0;
-	int ret = -ENOSPC;
-
-	if (!block_rsv)
-		return 0;
-
-	spin_lock(&block_rsv->lock);
-	num_bytes = min_reserved;
-	if (block_rsv->reserved >= num_bytes)
-		ret = 0;
-	else
-		num_bytes -= block_rsv->reserved;
-	spin_unlock(&block_rsv->lock);
-
-	if (!ret)
-		return 0;
-
-	ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush);
-	if (!ret) {
-		block_rsv_add_bytes(block_rsv, num_bytes, 0);
-		return 0;
-	}
-
-	return ret;
-}
-
-/**
- * btrfs_inode_rsv_refill - refill the inode block rsv.
- * @inode - the inode we are refilling.
- * @flush - the flusing restriction.
- *
- * Essentially the same as btrfs_block_rsv_refill, except it uses the
- * block_rsv->size as the minimum size.  We'll either refill the missing amount
- * or return if we already have enough space.  This will also handle the resreve
- * tracepoint for the reserved amount.
- */
-static int btrfs_inode_rsv_refill(struct btrfs_inode *inode,
-				  enum btrfs_reserve_flush_enum flush)
-{
-	struct btrfs_root *root = inode->root;
-	struct btrfs_block_rsv *block_rsv = &inode->block_rsv;
-	u64 num_bytes = 0;
-	u64 qgroup_num_bytes = 0;
-	int ret = -ENOSPC;
-
-	spin_lock(&block_rsv->lock);
-	if (block_rsv->reserved < block_rsv->size)
-		num_bytes = block_rsv->size - block_rsv->reserved;
-	if (block_rsv->qgroup_rsv_reserved < block_rsv->qgroup_rsv_size)
-		qgroup_num_bytes = block_rsv->qgroup_rsv_size -
-				   block_rsv->qgroup_rsv_reserved;
-	spin_unlock(&block_rsv->lock);
-
-	if (num_bytes == 0)
-		return 0;
-
-	ret = btrfs_qgroup_reserve_meta_prealloc(root, qgroup_num_bytes, true);
-	if (ret)
-		return ret;
-	ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush);
-	if (!ret) {
-		block_rsv_add_bytes(block_rsv, num_bytes, 0);
-		trace_btrfs_space_reservation(root->fs_info, "delalloc",
-					      btrfs_ino(inode), num_bytes, 1);
-
-		/* Don't forget to increase qgroup_rsv_reserved */
-		spin_lock(&block_rsv->lock);
-		block_rsv->qgroup_rsv_reserved += qgroup_num_bytes;
-		spin_unlock(&block_rsv->lock);
-	} else
-		btrfs_qgroup_free_meta_prealloc(root, qgroup_num_bytes);
-	return ret;
-}
-
-/**
- * btrfs_inode_rsv_release - release any excessive reservation.
- * @inode - the inode we need to release from.
- * @qgroup_free - free or convert qgroup meta.
- *   Unlike normal operation, qgroup meta reservation needs to know if we are
- *   freeing qgroup reservation or just converting it into per-trans.  Normally
- *   @qgroup_free is true for error handling, and false for normal release.
- *
- * This is the same as btrfs_block_rsv_release, except that it handles the
- * tracepoint for the reservation.
- */
-static void btrfs_inode_rsv_release(struct btrfs_inode *inode, bool qgroup_free)
-{
-	struct btrfs_fs_info *fs_info = inode->root->fs_info;
-	struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
-	struct btrfs_block_rsv *block_rsv = &inode->block_rsv;
-	u64 released = 0;
-	u64 qgroup_to_release = 0;
-
-	/*
-	 * Since we statically set the block_rsv->size we just want to say we
-	 * are releasing 0 bytes, and then we'll just get the reservation over
-	 * the size free'd.
-	 */
-	released = block_rsv_release_bytes(fs_info, block_rsv, global_rsv, 0,
-					   &qgroup_to_release);
-	if (released > 0)
-		trace_btrfs_space_reservation(fs_info, "delalloc",
-					      btrfs_ino(inode), released, 0);
-	if (qgroup_free)
-		btrfs_qgroup_free_meta_prealloc(inode->root, qgroup_to_release);
-	else
-		btrfs_qgroup_convert_reserved_meta(inode->root,
-						   qgroup_to_release);
-}
-
-void btrfs_block_rsv_release(struct btrfs_fs_info *fs_info,
-			     struct btrfs_block_rsv *block_rsv,
-			     u64 num_bytes)
-{
-	struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
-
-	if (global_rsv == block_rsv ||
-	    block_rsv->space_info != global_rsv->space_info)
-		global_rsv = NULL;
-	block_rsv_release_bytes(fs_info, block_rsv, global_rsv, num_bytes, NULL);
-}
-
-static void update_global_block_rsv(struct btrfs_fs_info *fs_info)
-{
-	struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
-	struct btrfs_space_info *sinfo = block_rsv->space_info;
-	u64 num_bytes;
-
-	/*
-	 * The global block rsv is based on the size of the extent tree, the
-	 * checksum tree and the root tree.  If the fs is empty we want to set
-	 * it to a minimal amount for safety.
-	 */
-	num_bytes = btrfs_root_used(&fs_info->extent_root->root_item) +
-		btrfs_root_used(&fs_info->csum_root->root_item) +
-		btrfs_root_used(&fs_info->tree_root->root_item);
-	num_bytes = max_t(u64, num_bytes, SZ_16M);
-
-	spin_lock(&sinfo->lock);
-	spin_lock(&block_rsv->lock);
-
-	block_rsv->size = min_t(u64, num_bytes, SZ_512M);
-
-	if (block_rsv->reserved < block_rsv->size) {
-		num_bytes = btrfs_space_info_used(sinfo, true);
-		if (sinfo->total_bytes > num_bytes) {
-			num_bytes = sinfo->total_bytes - num_bytes;
-			num_bytes = min(num_bytes,
-					block_rsv->size - block_rsv->reserved);
-			block_rsv->reserved += num_bytes;
-			sinfo->bytes_may_use += num_bytes;
-			trace_btrfs_space_reservation(fs_info, "space_info",
-						      sinfo->flags, num_bytes,
-						      1);
-		}
-	} else if (block_rsv->reserved > block_rsv->size) {
-		num_bytes = block_rsv->reserved - block_rsv->size;
-		sinfo->bytes_may_use -= num_bytes;
-		trace_btrfs_space_reservation(fs_info, "space_info",
-				      sinfo->flags, num_bytes, 0);
-		block_rsv->reserved = block_rsv->size;
-	}
-
-	if (block_rsv->reserved == block_rsv->size)
-		block_rsv->full = 1;
-	else
-		block_rsv->full = 0;
-
-	spin_unlock(&block_rsv->lock);
-	spin_unlock(&sinfo->lock);
-}
-
-static void init_global_block_rsv(struct btrfs_fs_info *fs_info)
-{
-	struct btrfs_space_info *space_info;
-
-	space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
-	fs_info->chunk_block_rsv.space_info = space_info;
-
-	space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
-	fs_info->global_block_rsv.space_info = space_info;
-	fs_info->trans_block_rsv.space_info = space_info;
-	fs_info->empty_block_rsv.space_info = space_info;
-	fs_info->delayed_block_rsv.space_info = space_info;
-
-	fs_info->extent_root->block_rsv = &fs_info->global_block_rsv;
-	fs_info->csum_root->block_rsv = &fs_info->global_block_rsv;
-	fs_info->dev_root->block_rsv = &fs_info->global_block_rsv;
-	fs_info->tree_root->block_rsv = &fs_info->global_block_rsv;
-	if (fs_info->quota_root)
-		fs_info->quota_root->block_rsv = &fs_info->global_block_rsv;
-	fs_info->chunk_root->block_rsv = &fs_info->chunk_block_rsv;
-
-	update_global_block_rsv(fs_info);
-}
-
-static void release_global_block_rsv(struct btrfs_fs_info *fs_info)
-{
-	block_rsv_release_bytes(fs_info, &fs_info->global_block_rsv, NULL,
-				(u64)-1, NULL);
-	WARN_ON(fs_info->trans_block_rsv.size > 0);
-	WARN_ON(fs_info->trans_block_rsv.reserved > 0);
-	WARN_ON(fs_info->chunk_block_rsv.size > 0);
-	WARN_ON(fs_info->chunk_block_rsv.reserved > 0);
-	WARN_ON(fs_info->delayed_block_rsv.size > 0);
-	WARN_ON(fs_info->delayed_block_rsv.reserved > 0);
-}
-
-
-/*
- * To be called after all the new block groups attached to the transaction
- * handle have been created (btrfs_create_pending_block_groups()).
- */
-void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans)
-{
-	struct btrfs_fs_info *fs_info = trans->fs_info;
-
-	if (!trans->chunk_bytes_reserved)
-		return;
-
-	WARN_ON_ONCE(!list_empty(&trans->new_bgs));
-
-	block_rsv_release_bytes(fs_info, &fs_info->chunk_block_rsv, NULL,
-				trans->chunk_bytes_reserved, NULL);
-	trans->chunk_bytes_reserved = 0;
-}
-
-/*
- * btrfs_subvolume_reserve_metadata() - reserve space for subvolume operation
- * root: the root of the parent directory
- * rsv: block reservation
- * items: the number of items that we need do reservation
- * use_global_rsv: allow fallback to the global block reservation
- *
- * This function is used to reserve the space for snapshot/subvolume
- * creation and deletion. Those operations are different with the
- * common file/directory operations, they change two fs/file trees
- * and root tree, the number of items that the qgroup reserves is
- * different with the free space reservation. So we can not use
- * the space reservation mechanism in start_transaction().
- */
-int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
-				     struct btrfs_block_rsv *rsv, int items,
-				     bool use_global_rsv)
-{
-	u64 qgroup_num_bytes = 0;
-	u64 num_bytes;
-	int ret;
-	struct btrfs_fs_info *fs_info = root->fs_info;
-	struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
-
-	if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {
-		/* One for parent inode, two for dir entries */
-		qgroup_num_bytes = 3 * fs_info->nodesize;
-		ret = btrfs_qgroup_reserve_meta_prealloc(root,
-				qgroup_num_bytes, true);
-		if (ret)
-			return ret;
-	}
-
-	num_bytes = btrfs_calc_trans_metadata_size(fs_info, items);
-	rsv->space_info = __find_space_info(fs_info,
-					    BTRFS_BLOCK_GROUP_METADATA);
-	ret = btrfs_block_rsv_add(root, rsv, num_bytes,
-				  BTRFS_RESERVE_FLUSH_ALL);
-
-	if (ret == -ENOSPC && use_global_rsv)
-		ret = btrfs_block_rsv_migrate(global_rsv, rsv, num_bytes, 1);
-
-	if (ret && qgroup_num_bytes)
-		btrfs_qgroup_free_meta_prealloc(root, qgroup_num_bytes);
-
-	return ret;
-}
-
-void btrfs_subvolume_release_metadata(struct btrfs_fs_info *fs_info,
-				      struct btrfs_block_rsv *rsv)
-{
-	btrfs_block_rsv_release(fs_info, rsv, (u64)-1);
-}
-
-static void btrfs_calculate_inode_block_rsv_size(struct btrfs_fs_info *fs_info,
-						 struct btrfs_inode *inode)
-{
-	struct btrfs_block_rsv *block_rsv = &inode->block_rsv;
-	u64 reserve_size = 0;
-	u64 qgroup_rsv_size = 0;
-	u64 csum_leaves;
-	unsigned outstanding_extents;
-
-	lockdep_assert_held(&inode->lock);
-	outstanding_extents = inode->outstanding_extents;
-	if (outstanding_extents)
-		reserve_size = btrfs_calc_trans_metadata_size(fs_info,
-						outstanding_extents + 1);
-	csum_leaves = btrfs_csum_bytes_to_leaves(fs_info,
-						 inode->csum_bytes);
-	reserve_size += btrfs_calc_trans_metadata_size(fs_info,
-						       csum_leaves);
-	/*
-	 * For qgroup rsv, the calculation is very simple:
-	 * account one nodesize for each outstanding extent
-	 *
-	 * This is overestimating in most cases.
-	 */
-	qgroup_rsv_size = outstanding_extents * fs_info->nodesize;
-
-	spin_lock(&block_rsv->lock);
-	block_rsv->size = reserve_size;
-	block_rsv->qgroup_rsv_size = qgroup_rsv_size;
-	spin_unlock(&block_rsv->lock);
-}
-
-int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes)
-{
-	struct btrfs_fs_info *fs_info = inode->root->fs_info;
-	unsigned nr_extents;
-	enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_FLUSH_ALL;
-	int ret = 0;
-	bool delalloc_lock = true;
-
-	/* If we are a free space inode we need to not flush since we will be in
-	 * the middle of a transaction commit.  We also don't need the delalloc
-	 * mutex since we won't race with anybody.  We need this mostly to make
-	 * lockdep shut its filthy mouth.
-	 *
-	 * If we have a transaction open (can happen if we call truncate_block
-	 * from truncate), then we need FLUSH_LIMIT so we don't deadlock.
-	 */
-	if (btrfs_is_free_space_inode(inode)) {
-		flush = BTRFS_RESERVE_NO_FLUSH;
-		delalloc_lock = false;
-	} else {
-		if (current->journal_info)
-			flush = BTRFS_RESERVE_FLUSH_LIMIT;
-
-		if (btrfs_transaction_in_commit(fs_info))
-			schedule_timeout(1);
-	}
-
-	if (delalloc_lock)
-		mutex_lock(&inode->delalloc_mutex);
-
-	num_bytes = ALIGN(num_bytes, fs_info->sectorsize);
-
-	/* Add our new extents and calculate the new rsv size. */
-	spin_lock(&inode->lock);
-	nr_extents = count_max_extents(num_bytes);
-	btrfs_mod_outstanding_extents(inode, nr_extents);
-	inode->csum_bytes += num_bytes;
-	btrfs_calculate_inode_block_rsv_size(fs_info, inode);
-	spin_unlock(&inode->lock);
-
-	ret = btrfs_inode_rsv_refill(inode, flush);
-	if (unlikely(ret))
-		goto out_fail;
-
-	if (delalloc_lock)
-		mutex_unlock(&inode->delalloc_mutex);
-	return 0;
-
-out_fail:
-	spin_lock(&inode->lock);
-	nr_extents = count_max_extents(num_bytes);
-	btrfs_mod_outstanding_extents(inode, -nr_extents);
-	inode->csum_bytes -= num_bytes;
-	btrfs_calculate_inode_block_rsv_size(fs_info, inode);
-	spin_unlock(&inode->lock);
-
-	btrfs_inode_rsv_release(inode, true);
-	if (delalloc_lock)
-		mutex_unlock(&inode->delalloc_mutex);
-	return ret;
-}
-
-/**
- * btrfs_delalloc_release_metadata - release a metadata reservation for an inode
- * @inode: the inode to release the reservation for.
- * @num_bytes: the number of bytes we are releasing.
- * @qgroup_free: free qgroup reservation or convert it to per-trans reservation
- *
- * This will release the metadata reservation for an inode.  This can be called
- * once we complete IO for a given set of bytes to release their metadata
- * reservations, or on error for the same reason.
- */
-void btrfs_delalloc_release_metadata(struct btrfs_inode *inode, u64 num_bytes,
-				     bool qgroup_free)
-{
-	struct btrfs_fs_info *fs_info = inode->root->fs_info;
-
-	num_bytes = ALIGN(num_bytes, fs_info->sectorsize);
-	spin_lock(&inode->lock);
-	inode->csum_bytes -= num_bytes;
-	btrfs_calculate_inode_block_rsv_size(fs_info, inode);
-	spin_unlock(&inode->lock);
-
-	if (btrfs_is_testing(fs_info))
-		return;
-
-	btrfs_inode_rsv_release(inode, qgroup_free);
-}
-
-/**
- * btrfs_delalloc_release_extents - release our outstanding_extents
- * @inode: the inode to balance the reservation for.
- * @num_bytes: the number of bytes we originally reserved with
- * @qgroup_free: do we need to free qgroup meta reservation or convert them.
- *
- * When we reserve space we increase outstanding_extents for the extents we may
- * add.  Once we've set the range as delalloc or created our ordered extents we
- * have outstanding_extents to track the real usage, so we use this to free our
- * temporarily tracked outstanding_extents.  This _must_ be used in conjunction
- * with btrfs_delalloc_reserve_metadata.
- */
-void btrfs_delalloc_release_extents(struct btrfs_inode *inode, u64 num_bytes,
-				    bool qgroup_free)
-{
-	struct btrfs_fs_info *fs_info = inode->root->fs_info;
-	unsigned num_extents;
-
-	spin_lock(&inode->lock);
-	num_extents = count_max_extents(num_bytes);
-	btrfs_mod_outstanding_extents(inode, -num_extents);
-	btrfs_calculate_inode_block_rsv_size(fs_info, inode);
-	spin_unlock(&inode->lock);
-
-	if (btrfs_is_testing(fs_info))
-		return;
-
-	btrfs_inode_rsv_release(inode, qgroup_free);
-}
-
-/**
- * btrfs_delalloc_reserve_space - reserve data and metadata space for
- * delalloc
- * @inode: inode we're writing to
- * @start: start range we are writing to
- * @len: how long the range we are writing to
- * @reserved: mandatory parameter, record actually reserved qgroup ranges of
- * 	      current reservation.
- *
- * This will do the following things
- *
- * o reserve space in data space info for num bytes
- *   and reserve precious corresponding qgroup space
- *   (Done in check_data_free_space)
- *
- * o reserve space for metadata space, based on the number of outstanding
- *   extents and how much csums will be needed
- *   also reserve metadata space in a per root over-reserve method.
- * o add to the inodes->delalloc_bytes
- * o add it to the fs_info's delalloc inodes list.
- *   (Above 3 all done in delalloc_reserve_metadata)
- *
- * Return 0 for success
- * Return <0 for error(-ENOSPC or -EQUOT)
- */
-int btrfs_delalloc_reserve_space(struct inode *inode,
-			struct extent_changeset **reserved, u64 start, u64 len)
-{
-	int ret;
-
-	ret = btrfs_check_data_free_space(inode, reserved, start, len);
-	if (ret < 0)
-		return ret;
-	ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), len);
-	if (ret < 0)
-		btrfs_free_reserved_data_space(inode, *reserved, start, len);
-	return ret;
-}
-
-/**
- * btrfs_delalloc_release_space - release data and metadata space for delalloc
- * @inode: inode we're releasing space for
- * @start: start position of the space already reserved
- * @len: the len of the space already reserved
- * @release_bytes: the len of the space we consumed or didn't use
- *
- * This function will release the metadata space that was not used and will
- * decrement ->delalloc_bytes and remove it from the fs_info delalloc_inodes
- * list if there are no delalloc bytes left.
- * Also it will handle the qgroup reserved space.
- */
-void btrfs_delalloc_release_space(struct inode *inode,
-				  struct extent_changeset *reserved,
-				  u64 start, u64 len, bool qgroup_free)
-{
-	btrfs_delalloc_release_metadata(BTRFS_I(inode), len, qgroup_free);
-	btrfs_free_reserved_data_space(inode, reserved, start, len);
-}
-
-static int update_block_group(struct btrfs_trans_handle *trans,
-			      struct btrfs_fs_info *info, u64 bytenr,
-			      u64 num_bytes, int alloc)
-{
-	struct btrfs_block_group_cache *cache = NULL;
-	u64 total = num_bytes;
-	u64 old_val;
-	u64 byte_in_group;
-	int factor;
-
-	/* block accounting for super block */
-	spin_lock(&info->delalloc_root_lock);
-	old_val = btrfs_super_bytes_used(info->super_copy);
-	if (alloc)
-		old_val += num_bytes;
-	else
-		old_val -= num_bytes;
-	btrfs_set_super_bytes_used(info->super_copy, old_val);
-	spin_unlock(&info->delalloc_root_lock);
-
-	while (total) {
-		cache = btrfs_lookup_block_group(info, bytenr);
-		if (!cache)
-			return -ENOENT;
-		factor = btrfs_bg_type_to_factor(cache->flags);
-
-		/*
-		 * If this block group has free space cache written out, we
-		 * need to make sure to load it if we are removing space.  This
-		 * is because we need the unpinning stage to actually add the
-		 * space back to the block group, otherwise we will leak space.
-		 */
-		if (!alloc && cache->cached == BTRFS_CACHE_NO)
-			cache_block_group(cache, 1);
-
-		byte_in_group = bytenr - cache->key.objectid;
-		WARN_ON(byte_in_group > cache->key.offset);
-
-		spin_lock(&cache->space_info->lock);
-		spin_lock(&cache->lock);
-
-		if (btrfs_test_opt(info, SPACE_CACHE) &&
-		    cache->disk_cache_state < BTRFS_DC_CLEAR)
-			cache->disk_cache_state = BTRFS_DC_CLEAR;
-
-		old_val = btrfs_block_group_used(&cache->item);
-		num_bytes = min(total, cache->key.offset - byte_in_group);
-		if (alloc) {
-			old_val += num_bytes;
-			btrfs_set_block_group_used(&cache->item, old_val);
-			cache->reserved -= num_bytes;
-			cache->space_info->bytes_reserved -= num_bytes;
-			cache->space_info->bytes_used += num_bytes;
-			cache->space_info->disk_used += num_bytes * factor;
-			spin_unlock(&cache->lock);
-			spin_unlock(&cache->space_info->lock);
-		} else {
-			old_val -= num_bytes;
-			btrfs_set_block_group_used(&cache->item, old_val);
-			cache->pinned += num_bytes;
-			cache->space_info->bytes_pinned += num_bytes;
-			cache->space_info->bytes_used -= num_bytes;
-			cache->space_info->disk_used -= num_bytes * factor;
-			spin_unlock(&cache->lock);
-			spin_unlock(&cache->space_info->lock);
-
-			trace_btrfs_space_reservation(info, "pinned",
-						      cache->space_info->flags,
-						      num_bytes, 1);
-			percpu_counter_add_batch(&cache->space_info->total_bytes_pinned,
-					   num_bytes,
-					   BTRFS_TOTAL_BYTES_PINNED_BATCH);
-			set_extent_dirty(info->pinned_extents,
-					 bytenr, bytenr + num_bytes - 1,
-					 GFP_NOFS | __GFP_NOFAIL);
-		}
-
-		spin_lock(&trans->transaction->dirty_bgs_lock);
-		if (list_empty(&cache->dirty_list)) {
-			list_add_tail(&cache->dirty_list,
-				      &trans->transaction->dirty_bgs);
-			trans->transaction->num_dirty_bgs++;
-			btrfs_get_block_group(cache);
-		}
-		spin_unlock(&trans->transaction->dirty_bgs_lock);
-
-		/*
-		 * No longer have used bytes in this block group, queue it for
-		 * deletion. We do this after adding the block group to the
-		 * dirty list to avoid races between cleaner kthread and space
-		 * cache writeout.
-		 */
-		if (!alloc && old_val == 0)
-			btrfs_mark_bg_unused(cache);
-
-		btrfs_put_block_group(cache);
-		total -= num_bytes;
-		bytenr += num_bytes;
-	}
-	return 0;
-}
-
 static u64 first_logical_byte(struct btrfs_fs_info *fs_info, u64 search_start)
 {
 	struct btrfs_block_group_cache *cache;
@@ -6182,14 +2566,16 @@
 	return bytenr;
 }
 
-static int pin_down_extent(struct btrfs_fs_info *fs_info,
-			   struct btrfs_block_group_cache *cache,
+static int pin_down_extent(struct btrfs_block_group_cache *cache,
 			   u64 bytenr, u64 num_bytes, int reserved)
 {
+	struct btrfs_fs_info *fs_info = cache->fs_info;
+
 	spin_lock(&cache->space_info->lock);
 	spin_lock(&cache->lock);
 	cache->pinned += num_bytes;
-	cache->space_info->bytes_pinned += num_bytes;
+	btrfs_space_info_update_bytes_pinned(fs_info, cache->space_info,
+					     num_bytes);
 	if (reserved) {
 		cache->reserved -= num_bytes;
 		cache->space_info->bytes_reserved -= num_bytes;
@@ -6197,8 +2583,6 @@
 	spin_unlock(&cache->lock);
 	spin_unlock(&cache->space_info->lock);
 
-	trace_btrfs_space_reservation(fs_info, "pinned",
-				      cache->space_info->flags, num_bytes, 1);
 	percpu_counter_add_batch(&cache->space_info->total_bytes_pinned,
 		    num_bytes, BTRFS_TOTAL_BYTES_PINNED_BATCH);
 	set_extent_dirty(fs_info->pinned_extents, bytenr,
@@ -6217,7 +2601,7 @@
 	cache = btrfs_lookup_block_group(fs_info, bytenr);
 	BUG_ON(!cache); /* Logic error */
 
-	pin_down_extent(fs_info, cache, bytenr, num_bytes, reserved);
+	pin_down_extent(cache, bytenr, num_bytes, reserved);
 
 	btrfs_put_block_group(cache);
 	return 0;
@@ -6242,9 +2626,9 @@
 	 * to one because the slow code to read in the free extents does check
 	 * the pinned extents.
 	 */
-	cache_block_group(cache, 1);
+	btrfs_cache_block_group(cache, 1);
 
-	pin_down_extent(fs_info, cache, bytenr, num_bytes, 0);
+	pin_down_extent(cache, bytenr, num_bytes, 0);
 
 	/* remove us from the free space cache (if we're there at all) */
 	ret = btrfs_remove_free_space(cache, bytenr, num_bytes);
@@ -6263,18 +2647,19 @@
 	if (!block_group)
 		return -EINVAL;
 
-	cache_block_group(block_group, 0);
-	caching_ctl = get_caching_control(block_group);
+	btrfs_cache_block_group(block_group, 0);
+	caching_ctl = btrfs_get_caching_control(block_group);
 
 	if (!caching_ctl) {
 		/* Logic error */
-		BUG_ON(!block_group_cache_done(block_group));
+		BUG_ON(!btrfs_block_group_cache_done(block_group));
 		ret = btrfs_remove_free_space(block_group, start, num_bytes);
 	} else {
 		mutex_lock(&caching_ctl->mutex);
 
 		if (start >= caching_ctl->progress) {
-			ret = add_excluded_extent(fs_info, start, num_bytes);
+			ret = btrfs_add_excluded_extent(fs_info, start,
+							num_bytes);
 		} else if (start + num_bytes <= caching_ctl->progress) {
 			ret = btrfs_remove_free_space(block_group,
 						      start, num_bytes);
@@ -6288,19 +2673,20 @@
 			num_bytes = (start + num_bytes) -
 				caching_ctl->progress;
 			start = caching_ctl->progress;
-			ret = add_excluded_extent(fs_info, start, num_bytes);
+			ret = btrfs_add_excluded_extent(fs_info, start,
+							num_bytes);
 		}
 out_lock:
 		mutex_unlock(&caching_ctl->mutex);
-		put_caching_control(caching_ctl);
+		btrfs_put_caching_control(caching_ctl);
 	}
 	btrfs_put_block_group(block_group);
 	return ret;
 }
 
-int btrfs_exclude_logged_extents(struct btrfs_fs_info *fs_info,
-				 struct extent_buffer *eb)
+int btrfs_exclude_logged_extents(struct extent_buffer *eb)
 {
+	struct btrfs_fs_info *fs_info = eb->fs_info;
 	struct btrfs_file_extent_item *item;
 	struct btrfs_key key;
 	int found_type;
@@ -6336,113 +2722,6 @@
 	atomic_inc(&bg->reservations);
 }
 
-void btrfs_dec_block_group_reservations(struct btrfs_fs_info *fs_info,
-					const u64 start)
-{
-	struct btrfs_block_group_cache *bg;
-
-	bg = btrfs_lookup_block_group(fs_info, start);
-	ASSERT(bg);
-	if (atomic_dec_and_test(&bg->reservations))
-		wake_up_var(&bg->reservations);
-	btrfs_put_block_group(bg);
-}
-
-void btrfs_wait_block_group_reservations(struct btrfs_block_group_cache *bg)
-{
-	struct btrfs_space_info *space_info = bg->space_info;
-
-	ASSERT(bg->ro);
-
-	if (!(bg->flags & BTRFS_BLOCK_GROUP_DATA))
-		return;
-
-	/*
-	 * Our block group is read only but before we set it to read only,
-	 * some task might have had allocated an extent from it already, but it
-	 * has not yet created a respective ordered extent (and added it to a
-	 * root's list of ordered extents).
-	 * Therefore wait for any task currently allocating extents, since the
-	 * block group's reservations counter is incremented while a read lock
-	 * on the groups' semaphore is held and decremented after releasing
-	 * the read access on that semaphore and creating the ordered extent.
-	 */
-	down_write(&space_info->groups_sem);
-	up_write(&space_info->groups_sem);
-
-	wait_var_event(&bg->reservations, !atomic_read(&bg->reservations));
-}
-
-/**
- * btrfs_add_reserved_bytes - update the block_group and space info counters
- * @cache:	The cache we are manipulating
- * @ram_bytes:  The number of bytes of file content, and will be same to
- *              @num_bytes except for the compress path.
- * @num_bytes:	The number of bytes in question
- * @delalloc:   The blocks are allocated for the delalloc write
- *
- * This is called by the allocator when it reserves space. If this is a
- * reservation and the block group has become read only we cannot make the
- * reservation and return -EAGAIN, otherwise this function always succeeds.
- */
-static int btrfs_add_reserved_bytes(struct btrfs_block_group_cache *cache,
-				    u64 ram_bytes, u64 num_bytes, int delalloc)
-{
-	struct btrfs_space_info *space_info = cache->space_info;
-	int ret = 0;
-
-	spin_lock(&space_info->lock);
-	spin_lock(&cache->lock);
-	if (cache->ro) {
-		ret = -EAGAIN;
-	} else {
-		cache->reserved += num_bytes;
-		space_info->bytes_reserved += num_bytes;
-
-		trace_btrfs_space_reservation(cache->fs_info,
-				"space_info", space_info->flags,
-				ram_bytes, 0);
-		space_info->bytes_may_use -= ram_bytes;
-		if (delalloc)
-			cache->delalloc_bytes += num_bytes;
-	}
-	spin_unlock(&cache->lock);
-	spin_unlock(&space_info->lock);
-	return ret;
-}
-
-/**
- * btrfs_free_reserved_bytes - update the block_group and space info counters
- * @cache:      The cache we are manipulating
- * @num_bytes:  The number of bytes in question
- * @delalloc:   The blocks are allocated for the delalloc write
- *
- * This is called by somebody who is freeing space that was never actually used
- * on disk.  For example if you reserve some space for a new leaf in transaction
- * A and before transaction A commits you free that leaf, you call this with
- * reserve set to 0 in order to clear the reservation.
- */
-
-static int btrfs_free_reserved_bytes(struct btrfs_block_group_cache *cache,
-				     u64 num_bytes, int delalloc)
-{
-	struct btrfs_space_info *space_info = cache->space_info;
-	int ret = 0;
-
-	spin_lock(&space_info->lock);
-	spin_lock(&cache->lock);
-	if (cache->ro)
-		space_info->bytes_readonly += num_bytes;
-	cache->reserved -= num_bytes;
-	space_info->bytes_reserved -= num_bytes;
-	space_info->max_extent_size = 0;
-
-	if (delalloc)
-		cache->delalloc_bytes -= num_bytes;
-	spin_unlock(&cache->lock);
-	spin_unlock(&space_info->lock);
-	return ret;
-}
 void btrfs_prepare_extent_commit(struct btrfs_fs_info *fs_info)
 {
 	struct btrfs_caching_control *next;
@@ -6454,10 +2733,10 @@
 	list_for_each_entry_safe(caching_ctl, next,
 				 &fs_info->caching_block_groups, list) {
 		cache = caching_ctl->block_group;
-		if (block_group_cache_done(cache)) {
+		if (btrfs_block_group_cache_done(cache)) {
 			cache->last_byte_to_unpin = (u64)-1;
 			list_del_init(&caching_ctl->list);
-			put_caching_control(caching_ctl);
+			btrfs_put_caching_control(caching_ctl);
 		} else {
 			cache->last_byte_to_unpin = caching_ctl->progress;
 		}
@@ -6470,7 +2749,7 @@
 
 	up_write(&fs_info->commit_root_sem);
 
-	update_global_block_rsv(fs_info);
+	btrfs_update_global_block_rsv(fs_info);
 }
 
 /*
@@ -6560,10 +2839,7 @@
 		spin_lock(&space_info->lock);
 		spin_lock(&cache->lock);
 		cache->pinned -= len;
-		space_info->bytes_pinned -= len;
-
-		trace_btrfs_space_reservation(fs_info, "pinned",
-					      space_info->flags, len, 0);
+		btrfs_space_info_update_bytes_pinned(fs_info, space_info, -len);
 		space_info->max_extent_size = 0;
 		percpu_counter_add_batch(&space_info->total_bytes_pinned,
 			    -len, BTRFS_TOTAL_BYTES_PINNED_BATCH);
@@ -6581,20 +2857,17 @@
 				to_add = min(len, global_rsv->size -
 					     global_rsv->reserved);
 				global_rsv->reserved += to_add;
-				space_info->bytes_may_use += to_add;
+				btrfs_space_info_update_bytes_may_use(fs_info,
+						space_info, to_add);
 				if (global_rsv->reserved >= global_rsv->size)
 					global_rsv->full = 1;
-				trace_btrfs_space_reservation(fs_info,
-							      "space_info",
-							      space_info->flags,
-							      to_add, 1);
 				len -= to_add;
 			}
 			spin_unlock(&global_rsv->lock);
 			/* Add to any tickets we may have */
 			if (len)
-				space_info_add_new_bytes(fs_info, space_info,
-							 len);
+				btrfs_try_granting_tickets(fs_info,
+							   space_info);
 		}
 		spin_unlock(&space_info->lock);
 	}
@@ -6620,9 +2893,11 @@
 		unpin = &fs_info->freed_extents[0];
 
 	while (!trans->aborted) {
+		struct extent_state *cached_state = NULL;
+
 		mutex_lock(&fs_info->unused_bg_unpin_mutex);
 		ret = find_first_extent_bit(unpin, 0, &start, &end,
-					    EXTENT_DIRTY, NULL);
+					    EXTENT_DIRTY, &cached_state);
 		if (ret) {
 			mutex_unlock(&fs_info->unused_bg_unpin_mutex);
 			break;
@@ -6632,9 +2907,10 @@
 			ret = btrfs_discard_extent(fs_info, start,
 						   end + 1 - start, NULL);
 
-		clear_extent_dirty(unpin, start, end);
+		clear_extent_dirty(unpin, start, end, &cached_state);
 		unpin_extent_range(fs_info, start, end, true);
 		mutex_unlock(&fs_info->unused_bg_unpin_mutex);
+		free_extent_state(cached_state);
 		cond_resched();
 	}
 
@@ -6892,7 +3168,7 @@
 			goto out;
 		}
 
-		ret = update_block_group(trans, info, bytenr, num_bytes, 0);
+		ret = btrfs_update_block_group(trans, bytenr, num_bytes, 0);
 		if (ret) {
 			btrfs_abort_transaction(trans, ret);
 			goto out;
@@ -6925,15 +3201,11 @@
 		goto out_delayed_unlock;
 
 	spin_lock(&head->lock);
-	if (!RB_EMPTY_ROOT(&head->ref_tree))
+	if (!RB_EMPTY_ROOT(&head->ref_tree.rb_root))
 		goto out;
 
-	if (head->extent_op) {
-		if (!head->must_insert_reserved)
-			goto out;
-		btrfs_free_delayed_extent_op(head->extent_op);
-		head->extent_op = NULL;
-	}
+	if (cleanup_extent_op(head) != NULL)
+		goto out;
 
 	/*
 	 * waiting for the lock here would deadlock.  If someone else has it
@@ -6942,22 +3214,9 @@
 	if (!mutex_trylock(&head->mutex))
 		goto out;
 
-	/*
-	 * at this point we have a head with no other entries.  Go
-	 * ahead and process it.
-	 */
-	rb_erase(&head->href_node, &delayed_refs->href_root);
-	RB_CLEAR_NODE(&head->href_node);
-	atomic_dec(&delayed_refs->num_entries);
-
-	/*
-	 * we don't take a ref on the node because we're removing it from the
-	 * tree, so we just steal the ref the tree was holding.
-	 */
-	delayed_refs->num_heads--;
-	if (head->processing == 0)
-		delayed_refs->num_heads_ready--;
+	btrfs_delete_ref_head(delayed_refs, head);
 	head->processing = 0;
+
 	spin_unlock(&head->lock);
 	spin_unlock(&delayed_refs->lock);
 
@@ -6965,6 +3224,7 @@
 	if (head->must_insert_reserved)
 		ret = 1;
 
+	btrfs_cleanup_ref_head_accounting(trans->fs_info, delayed_refs, head);
 	mutex_unlock(&head->mutex);
 	btrfs_put_delayed_ref_head(head);
 	return ret;
@@ -6982,21 +3242,20 @@
 			   u64 parent, int last_ref)
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct btrfs_ref generic_ref = { 0 };
 	int pin = 1;
 	int ret;
 
+	btrfs_init_generic_ref(&generic_ref, BTRFS_DROP_DELAYED_REF,
+			       buf->start, buf->len, parent);
+	btrfs_init_tree_ref(&generic_ref, btrfs_header_level(buf),
+			    root->root_key.objectid);
+
 	if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
 		int old_ref_mod, new_ref_mod;
 
-		btrfs_ref_tree_mod(root, buf->start, buf->len, parent,
-				   root->root_key.objectid,
-				   btrfs_header_level(buf), 0,
-				   BTRFS_DROP_DELAYED_REF);
-		ret = btrfs_add_delayed_tree_ref(trans, buf->start,
-						 buf->len, parent,
-						 root->root_key.objectid,
-						 btrfs_header_level(buf),
-						 BTRFS_DROP_DELAYED_REF, NULL,
+		btrfs_ref_tree_mod(fs_info, &generic_ref);
+		ret = btrfs_add_delayed_tree_ref(trans, &generic_ref, NULL,
 						 &old_ref_mod, &new_ref_mod);
 		BUG_ON(ret); /* -ENOMEM */
 		pin = old_ref_mod >= 0 && new_ref_mod < 0;
@@ -7015,8 +3274,7 @@
 		cache = btrfs_lookup_block_group(fs_info, buf->start);
 
 		if (btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
-			pin_down_extent(fs_info, cache, buf->start,
-					buf->len, 1);
+			pin_down_extent(cache, buf->start, buf->len, 1);
 			btrfs_put_block_group(cache);
 			goto out;
 		}
@@ -7030,8 +3288,7 @@
 	}
 out:
 	if (pin)
-		add_pinned_bytes(fs_info, buf->len, true,
-				 root->root_key.objectid);
+		add_pinned_bytes(fs_info, &generic_ref);
 
 	if (last_ref) {
 		/*
@@ -7043,108 +3300,52 @@
 }
 
 /* Can return -ENOMEM */
-int btrfs_free_extent(struct btrfs_trans_handle *trans,
-		      struct btrfs_root *root,
-		      u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid,
-		      u64 owner, u64 offset)
+int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_ref *ref)
 {
-	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct btrfs_fs_info *fs_info = trans->fs_info;
 	int old_ref_mod, new_ref_mod;
 	int ret;
 
 	if (btrfs_is_testing(fs_info))
 		return 0;
 
-	if (root_objectid != BTRFS_TREE_LOG_OBJECTID)
-		btrfs_ref_tree_mod(root, bytenr, num_bytes, parent,
-				   root_objectid, owner, offset,
-				   BTRFS_DROP_DELAYED_REF);
-
 	/*
 	 * tree log blocks never actually go into the extent allocation
 	 * tree, just update pinning info and exit early.
 	 */
-	if (root_objectid == BTRFS_TREE_LOG_OBJECTID) {
-		WARN_ON(owner >= BTRFS_FIRST_FREE_OBJECTID);
+	if ((ref->type == BTRFS_REF_METADATA &&
+	     ref->tree_ref.root == BTRFS_TREE_LOG_OBJECTID) ||
+	    (ref->type == BTRFS_REF_DATA &&
+	     ref->data_ref.ref_root == BTRFS_TREE_LOG_OBJECTID)) {
 		/* unlocks the pinned mutex */
-		btrfs_pin_extent(fs_info, bytenr, num_bytes, 1);
+		btrfs_pin_extent(fs_info, ref->bytenr, ref->len, 1);
 		old_ref_mod = new_ref_mod = 0;
 		ret = 0;
-	} else if (owner < BTRFS_FIRST_FREE_OBJECTID) {
-		ret = btrfs_add_delayed_tree_ref(trans, bytenr,
-						 num_bytes, parent,
-						 root_objectid, (int)owner,
-						 BTRFS_DROP_DELAYED_REF, NULL,
+	} else if (ref->type == BTRFS_REF_METADATA) {
+		ret = btrfs_add_delayed_tree_ref(trans, ref, NULL,
 						 &old_ref_mod, &new_ref_mod);
 	} else {
-		ret = btrfs_add_delayed_data_ref(trans, bytenr,
-						 num_bytes, parent,
-						 root_objectid, owner, offset,
-						 0, BTRFS_DROP_DELAYED_REF,
+		ret = btrfs_add_delayed_data_ref(trans, ref, 0,
 						 &old_ref_mod, &new_ref_mod);
 	}
 
-	if (ret == 0 && old_ref_mod >= 0 && new_ref_mod < 0) {
-		bool metadata = owner < BTRFS_FIRST_FREE_OBJECTID;
+	if (!((ref->type == BTRFS_REF_METADATA &&
+	       ref->tree_ref.root == BTRFS_TREE_LOG_OBJECTID) ||
+	      (ref->type == BTRFS_REF_DATA &&
+	       ref->data_ref.ref_root == BTRFS_TREE_LOG_OBJECTID)))
+		btrfs_ref_tree_mod(fs_info, ref);
 
-		add_pinned_bytes(fs_info, num_bytes, metadata, root_objectid);
-	}
+	if (ret == 0 && old_ref_mod >= 0 && new_ref_mod < 0)
+		add_pinned_bytes(fs_info, ref);
 
 	return ret;
 }
 
-/*
- * when we wait for progress in the block group caching, its because
- * our allocation attempt failed at least once.  So, we must sleep
- * and let some progress happen before we try again.
- *
- * This function will sleep at least once waiting for new free space to
- * show up, and then it will check the block group free space numbers
- * for our min num_bytes.  Another option is to have it go ahead
- * and look in the rbtree for a free extent of a given size, but this
- * is a good start.
- *
- * Callers of this must check if cache->cached == BTRFS_CACHE_ERROR before using
- * any of the information in this block group.
- */
-static noinline void
-wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
-				u64 num_bytes)
-{
-	struct btrfs_caching_control *caching_ctl;
-
-	caching_ctl = get_caching_control(cache);
-	if (!caching_ctl)
-		return;
-
-	wait_event(caching_ctl->wait, block_group_cache_done(cache) ||
-		   (cache->free_space_ctl->free_space >= num_bytes));
-
-	put_caching_control(caching_ctl);
-}
-
-static noinline int
-wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
-{
-	struct btrfs_caching_control *caching_ctl;
-	int ret = 0;
-
-	caching_ctl = get_caching_control(cache);
-	if (!caching_ctl)
-		return (cache->cached == BTRFS_CACHE_ERROR) ? -EIO : 0;
-
-	wait_event(caching_ctl->wait, block_group_cache_done(cache));
-	if (cache->cached == BTRFS_CACHE_ERROR)
-		ret = -EIO;
-	put_caching_control(caching_ctl);
-	return ret;
-}
-
 enum btrfs_loop_type {
-	LOOP_CACHING_NOWAIT = 0,
-	LOOP_CACHING_WAIT = 1,
-	LOOP_ALLOC_CHUNK = 2,
-	LOOP_NO_EMPTY_SIZE = 3,
+	LOOP_CACHING_NOWAIT,
+	LOOP_CACHING_WAIT,
+	LOOP_ALLOC_CHUNK,
+	LOOP_NO_EMPTY_SIZE,
 };
 
 static inline void
@@ -7212,6 +3413,343 @@
 }
 
 /*
+ * Structure used internally for find_free_extent() function.  Wraps needed
+ * parameters.
+ */
+struct find_free_extent_ctl {
+	/* Basic allocation info */
+	u64 ram_bytes;
+	u64 num_bytes;
+	u64 empty_size;
+	u64 flags;
+	int delalloc;
+
+	/* Where to start the search inside the bg */
+	u64 search_start;
+
+	/* For clustered allocation */
+	u64 empty_cluster;
+
+	bool have_caching_bg;
+	bool orig_have_caching_bg;
+
+	/* RAID index, converted from flags */
+	int index;
+
+	/*
+	 * Current loop number, check find_free_extent_update_loop() for details
+	 */
+	int loop;
+
+	/*
+	 * Whether we're refilling a cluster, if true we need to re-search
+	 * current block group but don't try to refill the cluster again.
+	 */
+	bool retry_clustered;
+
+	/*
+	 * Whether we're updating free space cache, if true we need to re-search
+	 * current block group but don't try updating free space cache again.
+	 */
+	bool retry_unclustered;
+
+	/* If current block group is cached */
+	int cached;
+
+	/* Max contiguous hole found */
+	u64 max_extent_size;
+
+	/* Total free space from free space cache, not always contiguous */
+	u64 total_free_space;
+
+	/* Found result */
+	u64 found_offset;
+};
+
+
+/*
+ * Helper function for find_free_extent().
+ *
+ * Return -ENOENT to inform caller that we need fallback to unclustered mode.
+ * Return -EAGAIN to inform caller that we need to re-search this block group
+ * Return >0 to inform caller that we find nothing
+ * Return 0 means we have found a location and set ffe_ctl->found_offset.
+ */
+static int find_free_extent_clustered(struct btrfs_block_group_cache *bg,
+		struct btrfs_free_cluster *last_ptr,
+		struct find_free_extent_ctl *ffe_ctl,
+		struct btrfs_block_group_cache **cluster_bg_ret)
+{
+	struct btrfs_block_group_cache *cluster_bg;
+	u64 aligned_cluster;
+	u64 offset;
+	int ret;
+
+	cluster_bg = btrfs_lock_cluster(bg, last_ptr, ffe_ctl->delalloc);
+	if (!cluster_bg)
+		goto refill_cluster;
+	if (cluster_bg != bg && (cluster_bg->ro ||
+	    !block_group_bits(cluster_bg, ffe_ctl->flags)))
+		goto release_cluster;
+
+	offset = btrfs_alloc_from_cluster(cluster_bg, last_ptr,
+			ffe_ctl->num_bytes, cluster_bg->key.objectid,
+			&ffe_ctl->max_extent_size);
+	if (offset) {
+		/* We have a block, we're done */
+		spin_unlock(&last_ptr->refill_lock);
+		trace_btrfs_reserve_extent_cluster(cluster_bg,
+				ffe_ctl->search_start, ffe_ctl->num_bytes);
+		*cluster_bg_ret = cluster_bg;
+		ffe_ctl->found_offset = offset;
+		return 0;
+	}
+	WARN_ON(last_ptr->block_group != cluster_bg);
+
+release_cluster:
+	/*
+	 * If we are on LOOP_NO_EMPTY_SIZE, we can't set up a new clusters, so
+	 * lets just skip it and let the allocator find whatever block it can
+	 * find. If we reach this point, we will have tried the cluster
+	 * allocator plenty of times and not have found anything, so we are
+	 * likely way too fragmented for the clustering stuff to find anything.
+	 *
+	 * However, if the cluster is taken from the current block group,
+	 * release the cluster first, so that we stand a better chance of
+	 * succeeding in the unclustered allocation.
+	 */
+	if (ffe_ctl->loop >= LOOP_NO_EMPTY_SIZE && cluster_bg != bg) {
+		spin_unlock(&last_ptr->refill_lock);
+		btrfs_release_block_group(cluster_bg, ffe_ctl->delalloc);
+		return -ENOENT;
+	}
+
+	/* This cluster didn't work out, free it and start over */
+	btrfs_return_cluster_to_free_space(NULL, last_ptr);
+
+	if (cluster_bg != bg)
+		btrfs_release_block_group(cluster_bg, ffe_ctl->delalloc);
+
+refill_cluster:
+	if (ffe_ctl->loop >= LOOP_NO_EMPTY_SIZE) {
+		spin_unlock(&last_ptr->refill_lock);
+		return -ENOENT;
+	}
+
+	aligned_cluster = max_t(u64,
+			ffe_ctl->empty_cluster + ffe_ctl->empty_size,
+			bg->full_stripe_len);
+	ret = btrfs_find_space_cluster(bg, last_ptr, ffe_ctl->search_start,
+			ffe_ctl->num_bytes, aligned_cluster);
+	if (ret == 0) {
+		/* Now pull our allocation out of this cluster */
+		offset = btrfs_alloc_from_cluster(bg, last_ptr,
+				ffe_ctl->num_bytes, ffe_ctl->search_start,
+				&ffe_ctl->max_extent_size);
+		if (offset) {
+			/* We found one, proceed */
+			spin_unlock(&last_ptr->refill_lock);
+			trace_btrfs_reserve_extent_cluster(bg,
+					ffe_ctl->search_start,
+					ffe_ctl->num_bytes);
+			ffe_ctl->found_offset = offset;
+			return 0;
+		}
+	} else if (!ffe_ctl->cached && ffe_ctl->loop > LOOP_CACHING_NOWAIT &&
+		   !ffe_ctl->retry_clustered) {
+		spin_unlock(&last_ptr->refill_lock);
+
+		ffe_ctl->retry_clustered = true;
+		btrfs_wait_block_group_cache_progress(bg, ffe_ctl->num_bytes +
+				ffe_ctl->empty_cluster + ffe_ctl->empty_size);
+		return -EAGAIN;
+	}
+	/*
+	 * At this point we either didn't find a cluster or we weren't able to
+	 * allocate a block from our cluster.  Free the cluster we've been
+	 * trying to use, and go to the next block group.
+	 */
+	btrfs_return_cluster_to_free_space(NULL, last_ptr);
+	spin_unlock(&last_ptr->refill_lock);
+	return 1;
+}
+
+/*
+ * Return >0 to inform caller that we find nothing
+ * Return 0 when we found an free extent and set ffe_ctrl->found_offset
+ * Return -EAGAIN to inform caller that we need to re-search this block group
+ */
+static int find_free_extent_unclustered(struct btrfs_block_group_cache *bg,
+		struct btrfs_free_cluster *last_ptr,
+		struct find_free_extent_ctl *ffe_ctl)
+{
+	u64 offset;
+
+	/*
+	 * We are doing an unclustered allocation, set the fragmented flag so
+	 * we don't bother trying to setup a cluster again until we get more
+	 * space.
+	 */
+	if (unlikely(last_ptr)) {
+		spin_lock(&last_ptr->lock);
+		last_ptr->fragmented = 1;
+		spin_unlock(&last_ptr->lock);
+	}
+	if (ffe_ctl->cached) {
+		struct btrfs_free_space_ctl *free_space_ctl;
+
+		free_space_ctl = bg->free_space_ctl;
+		spin_lock(&free_space_ctl->tree_lock);
+		if (free_space_ctl->free_space <
+		    ffe_ctl->num_bytes + ffe_ctl->empty_cluster +
+		    ffe_ctl->empty_size) {
+			ffe_ctl->total_free_space = max_t(u64,
+					ffe_ctl->total_free_space,
+					free_space_ctl->free_space);
+			spin_unlock(&free_space_ctl->tree_lock);
+			return 1;
+		}
+		spin_unlock(&free_space_ctl->tree_lock);
+	}
+
+	offset = btrfs_find_space_for_alloc(bg, ffe_ctl->search_start,
+			ffe_ctl->num_bytes, ffe_ctl->empty_size,
+			&ffe_ctl->max_extent_size);
+
+	/*
+	 * If we didn't find a chunk, and we haven't failed on this block group
+	 * before, and this block group is in the middle of caching and we are
+	 * ok with waiting, then go ahead and wait for progress to be made, and
+	 * set @retry_unclustered to true.
+	 *
+	 * If @retry_unclustered is true then we've already waited on this
+	 * block group once and should move on to the next block group.
+	 */
+	if (!offset && !ffe_ctl->retry_unclustered && !ffe_ctl->cached &&
+	    ffe_ctl->loop > LOOP_CACHING_NOWAIT) {
+		btrfs_wait_block_group_cache_progress(bg, ffe_ctl->num_bytes +
+						      ffe_ctl->empty_size);
+		ffe_ctl->retry_unclustered = true;
+		return -EAGAIN;
+	} else if (!offset) {
+		return 1;
+	}
+	ffe_ctl->found_offset = offset;
+	return 0;
+}
+
+/*
+ * Return >0 means caller needs to re-search for free extent
+ * Return 0 means we have the needed free extent.
+ * Return <0 means we failed to locate any free extent.
+ */
+static int find_free_extent_update_loop(struct btrfs_fs_info *fs_info,
+					struct btrfs_free_cluster *last_ptr,
+					struct btrfs_key *ins,
+					struct find_free_extent_ctl *ffe_ctl,
+					int full_search, bool use_cluster)
+{
+	struct btrfs_root *root = fs_info->extent_root;
+	int ret;
+
+	if ((ffe_ctl->loop == LOOP_CACHING_NOWAIT) &&
+	    ffe_ctl->have_caching_bg && !ffe_ctl->orig_have_caching_bg)
+		ffe_ctl->orig_have_caching_bg = true;
+
+	if (!ins->objectid && ffe_ctl->loop >= LOOP_CACHING_WAIT &&
+	    ffe_ctl->have_caching_bg)
+		return 1;
+
+	if (!ins->objectid && ++(ffe_ctl->index) < BTRFS_NR_RAID_TYPES)
+		return 1;
+
+	if (ins->objectid) {
+		if (!use_cluster && last_ptr) {
+			spin_lock(&last_ptr->lock);
+			last_ptr->window_start = ins->objectid;
+			spin_unlock(&last_ptr->lock);
+		}
+		return 0;
+	}
+
+	/*
+	 * LOOP_CACHING_NOWAIT, search partially cached block groups, kicking
+	 *			caching kthreads as we move along
+	 * LOOP_CACHING_WAIT, search everything, and wait if our bg is caching
+	 * LOOP_ALLOC_CHUNK, force a chunk allocation and try again
+	 * LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try
+	 *		       again
+	 */
+	if (ffe_ctl->loop < LOOP_NO_EMPTY_SIZE) {
+		ffe_ctl->index = 0;
+		if (ffe_ctl->loop == LOOP_CACHING_NOWAIT) {
+			/*
+			 * We want to skip the LOOP_CACHING_WAIT step if we
+			 * don't have any uncached bgs and we've already done a
+			 * full search through.
+			 */
+			if (ffe_ctl->orig_have_caching_bg || !full_search)
+				ffe_ctl->loop = LOOP_CACHING_WAIT;
+			else
+				ffe_ctl->loop = LOOP_ALLOC_CHUNK;
+		} else {
+			ffe_ctl->loop++;
+		}
+
+		if (ffe_ctl->loop == LOOP_ALLOC_CHUNK) {
+			struct btrfs_trans_handle *trans;
+			int exist = 0;
+
+			trans = current->journal_info;
+			if (trans)
+				exist = 1;
+			else
+				trans = btrfs_join_transaction(root);
+
+			if (IS_ERR(trans)) {
+				ret = PTR_ERR(trans);
+				return ret;
+			}
+
+			ret = btrfs_chunk_alloc(trans, ffe_ctl->flags,
+						CHUNK_ALLOC_FORCE);
+
+			/*
+			 * If we can't allocate a new chunk we've already looped
+			 * through at least once, move on to the NO_EMPTY_SIZE
+			 * case.
+			 */
+			if (ret == -ENOSPC)
+				ffe_ctl->loop = LOOP_NO_EMPTY_SIZE;
+
+			/* Do not bail out on ENOSPC since we can do more. */
+			if (ret < 0 && ret != -ENOSPC)
+				btrfs_abort_transaction(trans, ret);
+			else
+				ret = 0;
+			if (!exist)
+				btrfs_end_transaction(trans);
+			if (ret)
+				return ret;
+		}
+
+		if (ffe_ctl->loop == LOOP_NO_EMPTY_SIZE) {
+			/*
+			 * Don't loop again if we already have no empty_size and
+			 * no empty_cluster.
+			 */
+			if (ffe_ctl->empty_size == 0 &&
+			    ffe_ctl->empty_cluster == 0)
+				return -ENOSPC;
+			ffe_ctl->empty_size = 0;
+			ffe_ctl->empty_cluster = 0;
+		}
+		return 1;
+	}
+	return -ENOSPC;
+}
+
+/*
  * walks the btree of allocated extents and find a hole of a given size.
  * The key ins is changed to record the hole:
  * ins->objectid == start position
@@ -7221,6 +3759,20 @@
  *
  * If there is no suitable free space, we will record the max size of
  * the free space extent currently.
+ *
+ * The overall logic and call chain:
+ *
+ * find_free_extent()
+ * |- Iterate through all block groups
+ * |  |- Get a valid block group
+ * |  |- Try to do clustered allocation in that block group
+ * |  |- Try to do unclustered allocation in that block group
+ * |  |- Check if the result is valid
+ * |  |  |- If valid, then exit
+ * |  |- Jump to next block group
+ * |
+ * |- Push harder to find free extents
+ *    |- If not found, re-iterate all block groups
  */
 static noinline int find_free_extent(struct btrfs_fs_info *fs_info,
 				u64 ram_bytes, u64 num_bytes, u64 empty_size,
@@ -7228,31 +3780,35 @@
 				u64 flags, int delalloc)
 {
 	int ret = 0;
-	struct btrfs_root *root = fs_info->extent_root;
 	struct btrfs_free_cluster *last_ptr = NULL;
 	struct btrfs_block_group_cache *block_group = NULL;
-	u64 search_start = 0;
-	u64 max_extent_size = 0;
-	u64 max_free_space = 0;
-	u64 empty_cluster = 0;
+	struct find_free_extent_ctl ffe_ctl = {0};
 	struct btrfs_space_info *space_info;
-	int loop = 0;
-	int index = btrfs_bg_flags_to_raid_index(flags);
-	bool failed_cluster_refill = false;
-	bool failed_alloc = false;
 	bool use_cluster = true;
-	bool have_caching_bg = false;
-	bool orig_have_caching_bg = false;
 	bool full_search = false;
 
 	WARN_ON(num_bytes < fs_info->sectorsize);
+
+	ffe_ctl.ram_bytes = ram_bytes;
+	ffe_ctl.num_bytes = num_bytes;
+	ffe_ctl.empty_size = empty_size;
+	ffe_ctl.flags = flags;
+	ffe_ctl.search_start = 0;
+	ffe_ctl.retry_clustered = false;
+	ffe_ctl.retry_unclustered = false;
+	ffe_ctl.delalloc = delalloc;
+	ffe_ctl.index = btrfs_bg_flags_to_raid_index(flags);
+	ffe_ctl.have_caching_bg = false;
+	ffe_ctl.orig_have_caching_bg = false;
+	ffe_ctl.found_offset = 0;
+
 	ins->type = BTRFS_EXTENT_ITEM_KEY;
 	ins->objectid = 0;
 	ins->offset = 0;
 
 	trace_find_free_extent(fs_info, num_bytes, empty_size, flags);
 
-	space_info = __find_space_info(fs_info, flags);
+	space_info = btrfs_find_space_info(fs_info, flags);
 	if (!space_info) {
 		btrfs_err(fs_info, "No space info for %llu", flags);
 		return -ENOSPC;
@@ -7281,7 +3837,8 @@
 		spin_unlock(&space_info->lock);
 	}
 
-	last_ptr = fetch_cluster_info(fs_info, space_info, &empty_cluster);
+	last_ptr = fetch_cluster_info(fs_info, space_info,
+				      &ffe_ctl.empty_cluster);
 	if (last_ptr) {
 		spin_lock(&last_ptr->lock);
 		if (last_ptr->block_group)
@@ -7298,10 +3855,12 @@
 		spin_unlock(&last_ptr->lock);
 	}
 
-	search_start = max(search_start, first_logical_byte(fs_info, 0));
-	search_start = max(search_start, hint_byte);
-	if (search_start == hint_byte) {
-		block_group = btrfs_lookup_block_group(fs_info, search_start);
+	ffe_ctl.search_start = max(ffe_ctl.search_start,
+				   first_logical_byte(fs_info, 0));
+	ffe_ctl.search_start = max(ffe_ctl.search_start, hint_byte);
+	if (ffe_ctl.search_start == hint_byte) {
+		block_group = btrfs_lookup_block_group(fs_info,
+						       ffe_ctl.search_start);
 		/*
 		 * we don't want to use the block group if it doesn't match our
 		 * allocation bits, or if its not cached.
@@ -7323,7 +3882,7 @@
 				btrfs_put_block_group(block_group);
 				up_read(&space_info->groups_sem);
 			} else {
-				index = btrfs_bg_flags_to_raid_index(
+				ffe_ctl.index = btrfs_bg_flags_to_raid_index(
 						block_group->flags);
 				btrfs_lock_block_group(block_group, delalloc);
 				goto have_block_group;
@@ -7333,21 +3892,19 @@
 		}
 	}
 search:
-	have_caching_bg = false;
-	if (index == 0 || index == btrfs_bg_flags_to_raid_index(flags))
+	ffe_ctl.have_caching_bg = false;
+	if (ffe_ctl.index == btrfs_bg_flags_to_raid_index(flags) ||
+	    ffe_ctl.index == 0)
 		full_search = true;
 	down_read(&space_info->groups_sem);
-	list_for_each_entry(block_group, &space_info->block_groups[index],
-			    list) {
-		u64 offset;
-		int cached;
-
+	list_for_each_entry(block_group,
+			    &space_info->block_groups[ffe_ctl.index], list) {
 		/* If the block group is read-only, we can skip it entirely. */
 		if (unlikely(block_group->ro))
 			continue;
 
 		btrfs_grab_block_group(block_group, delalloc);
-		search_start = block_group->key.objectid;
+		ffe_ctl.search_start = block_group->key.objectid;
 
 		/*
 		 * this can happen if we end up cycling through all the
@@ -7356,9 +3913,8 @@
 		 */
 		if (!block_group_bits(block_group, flags)) {
 			u64 extra = BTRFS_BLOCK_GROUP_DUP |
-				BTRFS_BLOCK_GROUP_RAID1 |
-				BTRFS_BLOCK_GROUP_RAID5 |
-				BTRFS_BLOCK_GROUP_RAID6 |
+				BTRFS_BLOCK_GROUP_RAID1_MASK |
+				BTRFS_BLOCK_GROUP_RAID56_MASK |
 				BTRFS_BLOCK_GROUP_RAID10;
 
 			/*
@@ -7368,13 +3924,21 @@
 			 */
 			if ((flags & extra) && !(block_group->flags & extra))
 				goto loop;
+
+			/*
+			 * This block group has different flags than we want.
+			 * It's possible that we have MIXED_GROUP flag but no
+			 * block group is mixed.  Just skip such block group.
+			 */
+			btrfs_release_block_group(block_group, delalloc);
+			continue;
 		}
 
 have_block_group:
-		cached = block_group_cache_done(block_group);
-		if (unlikely(!cached)) {
-			have_caching_bg = true;
-			ret = cache_block_group(block_group, 0);
+		ffe_ctl.cached = btrfs_block_group_cache_done(block_group);
+		if (unlikely(!ffe_ctl.cached)) {
+			ffe_ctl.have_caching_bg = true;
+			ret = btrfs_cache_block_group(block_group, 0);
 			BUG_ON(ret < 0);
 			ret = 0;
 		}
@@ -7387,365 +3951,96 @@
 		 * lets look there
 		 */
 		if (last_ptr && use_cluster) {
-			struct btrfs_block_group_cache *used_block_group;
-			unsigned long aligned_cluster;
-			/*
-			 * the refill lock keeps out other
-			 * people trying to start a new cluster
-			 */
-			used_block_group = btrfs_lock_cluster(block_group,
-							      last_ptr,
-							      delalloc);
-			if (!used_block_group)
-				goto refill_cluster;
+			struct btrfs_block_group_cache *cluster_bg = NULL;
 
-			if (used_block_group != block_group &&
-			    (used_block_group->ro ||
-			     !block_group_bits(used_block_group, flags)))
-				goto release_cluster;
+			ret = find_free_extent_clustered(block_group, last_ptr,
+							 &ffe_ctl, &cluster_bg);
 
-			offset = btrfs_alloc_from_cluster(used_block_group,
-						last_ptr,
-						num_bytes,
-						used_block_group->key.objectid,
-						&max_extent_size);
-			if (offset) {
-				/* we have a block, we're done */
-				spin_unlock(&last_ptr->refill_lock);
-				trace_btrfs_reserve_extent_cluster(
-						used_block_group,
-						search_start, num_bytes);
-				if (used_block_group != block_group) {
+			if (ret == 0) {
+				if (cluster_bg && cluster_bg != block_group) {
 					btrfs_release_block_group(block_group,
 								  delalloc);
-					block_group = used_block_group;
+					block_group = cluster_bg;
 				}
 				goto checks;
-			}
-
-			WARN_ON(last_ptr->block_group != used_block_group);
-release_cluster:
-			/* If we are on LOOP_NO_EMPTY_SIZE, we can't
-			 * set up a new clusters, so lets just skip it
-			 * and let the allocator find whatever block
-			 * it can find.  If we reach this point, we
-			 * will have tried the cluster allocator
-			 * plenty of times and not have found
-			 * anything, so we are likely way too
-			 * fragmented for the clustering stuff to find
-			 * anything.
-			 *
-			 * However, if the cluster is taken from the
-			 * current block group, release the cluster
-			 * first, so that we stand a better chance of
-			 * succeeding in the unclustered
-			 * allocation.  */
-			if (loop >= LOOP_NO_EMPTY_SIZE &&
-			    used_block_group != block_group) {
-				spin_unlock(&last_ptr->refill_lock);
-				btrfs_release_block_group(used_block_group,
-							  delalloc);
-				goto unclustered_alloc;
-			}
-
-			/*
-			 * this cluster didn't work out, free it and
-			 * start over
-			 */
-			btrfs_return_cluster_to_free_space(NULL, last_ptr);
-
-			if (used_block_group != block_group)
-				btrfs_release_block_group(used_block_group,
-							  delalloc);
-refill_cluster:
-			if (loop >= LOOP_NO_EMPTY_SIZE) {
-				spin_unlock(&last_ptr->refill_lock);
-				goto unclustered_alloc;
-			}
-
-			aligned_cluster = max_t(unsigned long,
-						empty_cluster + empty_size,
-					      block_group->full_stripe_len);
-
-			/* allocate a cluster in this block group */
-			ret = btrfs_find_space_cluster(fs_info, block_group,
-						       last_ptr, search_start,
-						       num_bytes,
-						       aligned_cluster);
-			if (ret == 0) {
-				/*
-				 * now pull our allocation out of this
-				 * cluster
-				 */
-				offset = btrfs_alloc_from_cluster(block_group,
-							last_ptr,
-							num_bytes,
-							search_start,
-							&max_extent_size);
-				if (offset) {
-					/* we found one, proceed */
-					spin_unlock(&last_ptr->refill_lock);
-					trace_btrfs_reserve_extent_cluster(
-						block_group, search_start,
-						num_bytes);
-					goto checks;
-				}
-			} else if (!cached && loop > LOOP_CACHING_NOWAIT
-				   && !failed_cluster_refill) {
-				spin_unlock(&last_ptr->refill_lock);
-
-				failed_cluster_refill = true;
-				wait_block_group_cache_progress(block_group,
-				       num_bytes + empty_cluster + empty_size);
+			} else if (ret == -EAGAIN) {
 				goto have_block_group;
-			}
-
-			/*
-			 * at this point we either didn't find a cluster
-			 * or we weren't able to allocate a block from our
-			 * cluster.  Free the cluster we've been trying
-			 * to use, and go to the next block group
-			 */
-			btrfs_return_cluster_to_free_space(NULL, last_ptr);
-			spin_unlock(&last_ptr->refill_lock);
-			goto loop;
-		}
-
-unclustered_alloc:
-		/*
-		 * We are doing an unclustered alloc, set the fragmented flag so
-		 * we don't bother trying to setup a cluster again until we get
-		 * more space.
-		 */
-		if (unlikely(last_ptr)) {
-			spin_lock(&last_ptr->lock);
-			last_ptr->fragmented = 1;
-			spin_unlock(&last_ptr->lock);
-		}
-		if (cached) {
-			struct btrfs_free_space_ctl *ctl =
-				block_group->free_space_ctl;
-
-			spin_lock(&ctl->tree_lock);
-			if (ctl->free_space <
-			    num_bytes + empty_cluster + empty_size) {
-				max_free_space = max(max_free_space,
-						     ctl->free_space);
-				spin_unlock(&ctl->tree_lock);
+			} else if (ret > 0) {
 				goto loop;
 			}
-			spin_unlock(&ctl->tree_lock);
+			/* ret == -ENOENT case falls through */
 		}
 
-		offset = btrfs_find_space_for_alloc(block_group, search_start,
-						    num_bytes, empty_size,
-						    &max_extent_size);
-		/*
-		 * If we didn't find a chunk, and we haven't failed on this
-		 * block group before, and this block group is in the middle of
-		 * caching and we are ok with waiting, then go ahead and wait
-		 * for progress to be made, and set failed_alloc to true.
-		 *
-		 * If failed_alloc is true then we've already waited on this
-		 * block group once and should move on to the next block group.
-		 */
-		if (!offset && !failed_alloc && !cached &&
-		    loop > LOOP_CACHING_NOWAIT) {
-			wait_block_group_cache_progress(block_group,
-						num_bytes + empty_size);
-			failed_alloc = true;
+		ret = find_free_extent_unclustered(block_group, last_ptr,
+						   &ffe_ctl);
+		if (ret == -EAGAIN)
 			goto have_block_group;
-		} else if (!offset) {
+		else if (ret > 0)
 			goto loop;
-		}
+		/* ret == 0 case falls through */
 checks:
-		search_start = round_up(offset, fs_info->stripesize);
+		ffe_ctl.search_start = round_up(ffe_ctl.found_offset,
+					     fs_info->stripesize);
 
 		/* move on to the next group */
-		if (search_start + num_bytes >
+		if (ffe_ctl.search_start + num_bytes >
 		    block_group->key.objectid + block_group->key.offset) {
-			btrfs_add_free_space(block_group, offset, num_bytes);
+			btrfs_add_free_space(block_group, ffe_ctl.found_offset,
+					     num_bytes);
 			goto loop;
 		}
 
-		if (offset < search_start)
-			btrfs_add_free_space(block_group, offset,
-					     search_start - offset);
+		if (ffe_ctl.found_offset < ffe_ctl.search_start)
+			btrfs_add_free_space(block_group, ffe_ctl.found_offset,
+				ffe_ctl.search_start - ffe_ctl.found_offset);
 
 		ret = btrfs_add_reserved_bytes(block_group, ram_bytes,
 				num_bytes, delalloc);
 		if (ret == -EAGAIN) {
-			btrfs_add_free_space(block_group, offset, num_bytes);
+			btrfs_add_free_space(block_group, ffe_ctl.found_offset,
+					     num_bytes);
 			goto loop;
 		}
 		btrfs_inc_block_group_reservations(block_group);
 
 		/* we are all good, lets return */
-		ins->objectid = search_start;
+		ins->objectid = ffe_ctl.search_start;
 		ins->offset = num_bytes;
 
-		trace_btrfs_reserve_extent(block_group, search_start, num_bytes);
+		trace_btrfs_reserve_extent(block_group, ffe_ctl.search_start,
+					   num_bytes);
 		btrfs_release_block_group(block_group, delalloc);
 		break;
 loop:
-		failed_cluster_refill = false;
-		failed_alloc = false;
+		ffe_ctl.retry_clustered = false;
+		ffe_ctl.retry_unclustered = false;
 		BUG_ON(btrfs_bg_flags_to_raid_index(block_group->flags) !=
-		       index);
+		       ffe_ctl.index);
 		btrfs_release_block_group(block_group, delalloc);
 		cond_resched();
 	}
 	up_read(&space_info->groups_sem);
 
-	if ((loop == LOOP_CACHING_NOWAIT) && have_caching_bg
-		&& !orig_have_caching_bg)
-		orig_have_caching_bg = true;
-
-	if (!ins->objectid && loop >= LOOP_CACHING_WAIT && have_caching_bg)
+	ret = find_free_extent_update_loop(fs_info, last_ptr, ins, &ffe_ctl,
+					   full_search, use_cluster);
+	if (ret > 0)
 		goto search;
 
-	if (!ins->objectid && ++index < BTRFS_NR_RAID_TYPES)
-		goto search;
-
-	/*
-	 * LOOP_CACHING_NOWAIT, search partially cached block groups, kicking
-	 *			caching kthreads as we move along
-	 * LOOP_CACHING_WAIT, search everything, and wait if our bg is caching
-	 * LOOP_ALLOC_CHUNK, force a chunk allocation and try again
-	 * LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try
-	 *			again
-	 */
-	if (!ins->objectid && loop < LOOP_NO_EMPTY_SIZE) {
-		index = 0;
-		if (loop == LOOP_CACHING_NOWAIT) {
-			/*
-			 * We want to skip the LOOP_CACHING_WAIT step if we
-			 * don't have any uncached bgs and we've already done a
-			 * full search through.
-			 */
-			if (orig_have_caching_bg || !full_search)
-				loop = LOOP_CACHING_WAIT;
-			else
-				loop = LOOP_ALLOC_CHUNK;
-		} else {
-			loop++;
-		}
-
-		if (loop == LOOP_ALLOC_CHUNK) {
-			struct btrfs_trans_handle *trans;
-			int exist = 0;
-
-			trans = current->journal_info;
-			if (trans)
-				exist = 1;
-			else
-				trans = btrfs_join_transaction(root);
-
-			if (IS_ERR(trans)) {
-				ret = PTR_ERR(trans);
-				goto out;
-			}
-
-			ret = do_chunk_alloc(trans, flags, CHUNK_ALLOC_FORCE);
-
-			/*
-			 * If we can't allocate a new chunk we've already looped
-			 * through at least once, move on to the NO_EMPTY_SIZE
-			 * case.
-			 */
-			if (ret == -ENOSPC)
-				loop = LOOP_NO_EMPTY_SIZE;
-
-			/*
-			 * Do not bail out on ENOSPC since we
-			 * can do more things.
-			 */
-			if (ret < 0 && ret != -ENOSPC)
-				btrfs_abort_transaction(trans, ret);
-			else
-				ret = 0;
-			if (!exist)
-				btrfs_end_transaction(trans);
-			if (ret)
-				goto out;
-		}
-
-		if (loop == LOOP_NO_EMPTY_SIZE) {
-			/*
-			 * Don't loop again if we already have no empty_size and
-			 * no empty_cluster.
-			 */
-			if (empty_size == 0 &&
-			    empty_cluster == 0) {
-				ret = -ENOSPC;
-				goto out;
-			}
-			empty_size = 0;
-			empty_cluster = 0;
-		}
-
-		goto search;
-	} else if (!ins->objectid) {
-		ret = -ENOSPC;
-	} else if (ins->objectid) {
-		if (!use_cluster && last_ptr) {
-			spin_lock(&last_ptr->lock);
-			last_ptr->window_start = ins->objectid;
-			spin_unlock(&last_ptr->lock);
-		}
-		ret = 0;
-	}
-out:
 	if (ret == -ENOSPC) {
-		if (!max_extent_size)
-			max_extent_size = max_free_space;
+		/*
+		 * Use ffe_ctl->total_free_space as fallback if we can't find
+		 * any contiguous hole.
+		 */
+		if (!ffe_ctl.max_extent_size)
+			ffe_ctl.max_extent_size = ffe_ctl.total_free_space;
 		spin_lock(&space_info->lock);
-		space_info->max_extent_size = max_extent_size;
+		space_info->max_extent_size = ffe_ctl.max_extent_size;
 		spin_unlock(&space_info->lock);
-		ins->offset = max_extent_size;
+		ins->offset = ffe_ctl.max_extent_size;
 	}
 	return ret;
 }
 
-static void dump_space_info(struct btrfs_fs_info *fs_info,
-			    struct btrfs_space_info *info, u64 bytes,
-			    int dump_block_groups)
-{
-	struct btrfs_block_group_cache *cache;
-	int index = 0;
-
-	spin_lock(&info->lock);
-	btrfs_info(fs_info, "space_info %llu has %llu free, is %sfull",
-		   info->flags,
-		   info->total_bytes - btrfs_space_info_used(info, true),
-		   info->full ? "" : "not ");
-	btrfs_info(fs_info,
-		"space_info total=%llu, used=%llu, pinned=%llu, reserved=%llu, may_use=%llu, readonly=%llu",
-		info->total_bytes, info->bytes_used, info->bytes_pinned,
-		info->bytes_reserved, info->bytes_may_use,
-		info->bytes_readonly);
-	spin_unlock(&info->lock);
-
-	if (!dump_block_groups)
-		return;
-
-	down_read(&info->groups_sem);
-again:
-	list_for_each_entry(cache, &info->block_groups[index], list) {
-		spin_lock(&cache->lock);
-		btrfs_info(fs_info,
-			"block group %llu has %llu bytes, %llu used %llu pinned %llu reserved %s",
-			cache->key.objectid, cache->key.offset,
-			btrfs_block_group_used(&cache->item), cache->pinned,
-			cache->reserved, cache->ro ? "[readonly]" : "");
-		btrfs_dump_free_space(cache, bytes);
-		spin_unlock(&cache->lock);
-	}
-	if (++index < BTRFS_NR_RAID_TYPES)
-		goto again;
-	up_read(&info->groups_sem);
-}
-
 /*
  * btrfs_reserve_extent - entry point to the extent allocator. Tries to find a
  *			  hole that is at least as big as @num_bytes.
@@ -7821,12 +4116,13 @@
 		} else if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
 			struct btrfs_space_info *sinfo;
 
-			sinfo = __find_space_info(fs_info, flags);
+			sinfo = btrfs_find_space_info(fs_info, flags);
 			btrfs_err(fs_info,
 				  "allocation failed flags %llu, wanted %llu",
 				  flags, num_bytes);
 			if (sinfo)
-				dump_space_info(fs_info, sinfo, num_bytes, 1);
+				btrfs_dump_space_info(fs_info, sinfo,
+						      num_bytes, 1);
 		}
 	}
 
@@ -7848,7 +4144,7 @@
 	}
 
 	if (pin)
-		pin_down_extent(fs_info, cache, start, len, 1);
+		pin_down_extent(cache, start, len, 1);
 	else {
 		if (btrfs_test_opt(fs_info, DISCARD))
 			ret = btrfs_discard_extent(fs_info, start, len, NULL);
@@ -7937,7 +4233,7 @@
 	if (ret)
 		return ret;
 
-	ret = update_block_group(trans, fs_info, ins->objectid, ins->offset, 1);
+	ret = btrfs_update_block_group(trans, ins->objectid, ins->offset, 1);
 	if (ret) { /* -ENOENT, logic error */
 		btrfs_err(fs_info, "update block group failed for %llu %llu",
 			ins->objectid, ins->offset);
@@ -8027,8 +4323,8 @@
 	if (ret)
 		return ret;
 
-	ret = update_block_group(trans, fs_info, extent_key.objectid,
-				 fs_info->nodesize, 1);
+	ret = btrfs_update_block_group(trans, extent_key.objectid,
+				       fs_info->nodesize, 1);
 	if (ret) { /* -ENOENT, logic error */
 		btrfs_err(fs_info, "update block group failed for %llu %llu",
 			extent_key.objectid, extent_key.offset);
@@ -8045,19 +4341,17 @@
 				     u64 offset, u64 ram_bytes,
 				     struct btrfs_key *ins)
 {
+	struct btrfs_ref generic_ref = { 0 };
 	int ret;
 
 	BUG_ON(root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID);
 
-	btrfs_ref_tree_mod(root, ins->objectid, ins->offset, 0,
-			   root->root_key.objectid, owner, offset,
-			   BTRFS_ADD_DELAYED_EXTENT);
-
-	ret = btrfs_add_delayed_data_ref(trans, ins->objectid,
-					 ins->offset, 0,
-					 root->root_key.objectid, owner,
-					 offset, ram_bytes,
-					 BTRFS_ADD_DELAYED_EXTENT, NULL, NULL);
+	btrfs_init_generic_ref(&generic_ref, BTRFS_ADD_DELAYED_EXTENT,
+			       ins->objectid, ins->offset, 0);
+	btrfs_init_data_ref(&generic_ref, root->root_key.objectid, owner, offset);
+	btrfs_ref_tree_mod(root->fs_info, &generic_ref);
+	ret = btrfs_add_delayed_data_ref(trans, &generic_ref,
+					 ram_bytes, NULL, NULL);
 	return ret;
 }
 
@@ -8130,10 +4424,10 @@
 
 	btrfs_set_buffer_lockdep_class(root->root_key.objectid, buf, level);
 	btrfs_tree_lock(buf);
-	clean_tree_block(fs_info, buf);
+	btrfs_clean_tree_block(buf);
 	clear_bit(EXTENT_BUFFER_STALE, &buf->bflags);
 
-	btrfs_set_lock_blocking(buf);
+	btrfs_set_lock_blocking_write(buf);
 	set_extent_buffer_uptodate(buf);
 
 	memzero_extent_buffer(buf, 0, sizeof(struct btrfs_header));
@@ -8142,13 +4436,13 @@
 	btrfs_set_header_generation(buf, trans->transid);
 	btrfs_set_header_backref_rev(buf, BTRFS_MIXED_BACKREF_REV);
 	btrfs_set_header_owner(buf, owner);
-	write_extent_buffer_fsid(buf, fs_info->fsid);
+	write_extent_buffer_fsid(buf, fs_info->fs_devices->metadata_uuid);
 	write_extent_buffer_chunk_tree_uuid(buf, fs_info->chunk_tree_uuid);
 	if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
 		buf->log_index = root->log_transid % 2;
 		/*
 		 * we allow two log transactions at a time, use different
-		 * EXENT bit to differentiate dirty pages.
+		 * EXTENT bit to differentiate dirty pages.
 		 */
 		if (buf->log_index == 0)
 			set_extent_dirty(&root->dirty_log_pages, buf->start,
@@ -8166,68 +4460,6 @@
 	return buf;
 }
 
-static struct btrfs_block_rsv *
-use_block_rsv(struct btrfs_trans_handle *trans,
-	      struct btrfs_root *root, u32 blocksize)
-{
-	struct btrfs_fs_info *fs_info = root->fs_info;
-	struct btrfs_block_rsv *block_rsv;
-	struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
-	int ret;
-	bool global_updated = false;
-
-	block_rsv = get_block_rsv(trans, root);
-
-	if (unlikely(block_rsv->size == 0))
-		goto try_reserve;
-again:
-	ret = block_rsv_use_bytes(block_rsv, blocksize);
-	if (!ret)
-		return block_rsv;
-
-	if (block_rsv->failfast)
-		return ERR_PTR(ret);
-
-	if (block_rsv->type == BTRFS_BLOCK_RSV_GLOBAL && !global_updated) {
-		global_updated = true;
-		update_global_block_rsv(fs_info);
-		goto again;
-	}
-
-	if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
-		static DEFINE_RATELIMIT_STATE(_rs,
-				DEFAULT_RATELIMIT_INTERVAL * 10,
-				/*DEFAULT_RATELIMIT_BURST*/ 1);
-		if (__ratelimit(&_rs))
-			WARN(1, KERN_DEBUG
-				"BTRFS: block rsv returned %d\n", ret);
-	}
-try_reserve:
-	ret = reserve_metadata_bytes(root, block_rsv, blocksize,
-				     BTRFS_RESERVE_NO_FLUSH);
-	if (!ret)
-		return block_rsv;
-	/*
-	 * If we couldn't reserve metadata bytes try and use some from
-	 * the global reserve if its space type is the same as the global
-	 * reservation.
-	 */
-	if (block_rsv->type != BTRFS_BLOCK_RSV_GLOBAL &&
-	    block_rsv->space_info == global_rsv->space_info) {
-		ret = block_rsv_use_bytes(global_rsv, blocksize);
-		if (!ret)
-			return global_rsv;
-	}
-	return ERR_PTR(ret);
-}
-
-static void unuse_block_rsv(struct btrfs_fs_info *fs_info,
-			    struct btrfs_block_rsv *block_rsv, u32 blocksize)
-{
-	block_rsv_add_bytes(block_rsv, blocksize, 0);
-	block_rsv_release_bytes(fs_info, block_rsv, NULL, 0, NULL);
-}
-
 /*
  * finds a free extent and does all the dirty work required for allocation
  * returns the tree buffer or an ERR_PTR on error.
@@ -8244,6 +4476,7 @@
 	struct btrfs_block_rsv *block_rsv;
 	struct extent_buffer *buf;
 	struct btrfs_delayed_extent_op *extent_op;
+	struct btrfs_ref generic_ref = { 0 };
 	u64 flags = 0;
 	int ret;
 	u32 blocksize = fs_info->nodesize;
@@ -8259,7 +4492,7 @@
 	}
 #endif
 
-	block_rsv = use_block_rsv(trans, root, blocksize);
+	block_rsv = btrfs_use_block_rsv(trans, root, blocksize);
 	if (IS_ERR(block_rsv))
 		return ERR_CAST(block_rsv);
 
@@ -8298,13 +4531,12 @@
 		extent_op->is_data = false;
 		extent_op->level = level;
 
-		btrfs_ref_tree_mod(root, ins.objectid, ins.offset, parent,
-				   root_objectid, level, 0,
-				   BTRFS_ADD_DELAYED_EXTENT);
-		ret = btrfs_add_delayed_tree_ref(trans, ins.objectid,
-						 ins.offset, parent,
-						 root_objectid, level,
-						 BTRFS_ADD_DELAYED_EXTENT,
+		btrfs_init_generic_ref(&generic_ref, BTRFS_ADD_DELAYED_EXTENT,
+				       ins.objectid, ins.offset, parent);
+		generic_ref.real_root = root->root_key.objectid;
+		btrfs_init_tree_ref(&generic_ref, level, root_objectid);
+		btrfs_ref_tree_mod(fs_info, &generic_ref);
+		ret = btrfs_add_delayed_tree_ref(trans, &generic_ref,
 						 extent_op, NULL, NULL);
 		if (ret)
 			goto out_free_delayed;
@@ -8318,7 +4550,7 @@
 out_free_reserved:
 	btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 0);
 out_unuse:
-	unuse_block_rsv(fs_info, block_rsv, blocksize);
+	btrfs_unuse_block_rsv(fs_info, block_rsv, blocksize);
 	return ERR_PTR(ret);
 }
 
@@ -8326,6 +4558,8 @@
 	u64 refs[BTRFS_MAX_LEVEL];
 	u64 flags[BTRFS_MAX_LEVEL];
 	struct btrfs_key update_progress;
+	struct btrfs_key drop_progress;
+	int drop_level;
 	int stage;
 	int level;
 	int shared_level;
@@ -8333,6 +4567,7 @@
 	int keep_locks;
 	int reada_slot;
 	int reada_count;
+	int restarted;
 };
 
 #define DROP_REFERENCE	1
@@ -8477,7 +4712,7 @@
 		BUG_ON(ret); /* -ENOMEM */
 		ret = btrfs_dec_ref(trans, root, eb, 0);
 		BUG_ON(ret); /* -ENOMEM */
-		ret = btrfs_set_disk_extent_flags(trans, fs_info, eb->start,
+		ret = btrfs_set_disk_extent_flags(trans, eb->start,
 						  eb->len, flag,
 						  btrfs_header_level(eb), 0);
 		BUG_ON(ret); /* -ENOMEM */
@@ -8496,6 +4731,33 @@
 }
 
 /*
+ * This is used to verify a ref exists for this root to deal with a bug where we
+ * would have a drop_progress key that hadn't been updated properly.
+ */
+static int check_ref_exists(struct btrfs_trans_handle *trans,
+			    struct btrfs_root *root, u64 bytenr, u64 parent,
+			    int level)
+{
+	struct btrfs_path *path;
+	struct btrfs_extent_inline_ref *iref;
+	int ret;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	ret = lookup_extent_backref(trans, path, &iref, bytenr,
+				    root->fs_info->nodesize, parent,
+				    root->root_key.objectid, level, 0);
+	btrfs_free_path(path);
+	if (ret == -ENOENT)
+		return 0;
+	if (ret < 0)
+		return ret;
+	return 1;
+}
+
+/*
  * helper to process tree block pointer.
  *
  * when wc->stage == DROP_REFERENCE, this function checks
@@ -8517,9 +4779,9 @@
 	u64 bytenr;
 	u64 generation;
 	u64 parent;
-	u32 blocksize;
 	struct btrfs_key key;
 	struct btrfs_key first_key;
+	struct btrfs_ref ref = { 0 };
 	struct extent_buffer *next;
 	int level = wc->level;
 	int reada = 0;
@@ -8542,7 +4804,6 @@
 	bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]);
 	btrfs_node_key_to_cpu(path->nodes[level], &first_key,
 			      path->slots[level]);
-	blocksize = fs_info->nodesize;
 
 	next = find_extent_buffer(fs_info, bytenr);
 	if (!next) {
@@ -8555,7 +4816,7 @@
 		reada = 1;
 	}
 	btrfs_tree_lock(next);
-	btrfs_set_lock_blocking(next);
+	btrfs_set_lock_blocking_write(next);
 
 	ret = btrfs_lookup_extent_info(trans, fs_info, bytenr, level - 1, 1,
 				       &wc->refs[level - 1],
@@ -8615,7 +4876,7 @@
 			return -EIO;
 		}
 		btrfs_tree_lock(next);
-		btrfs_set_lock_blocking(next);
+		btrfs_set_lock_blocking_write(next);
 	}
 
 	level--;
@@ -8651,7 +4912,30 @@
 			parent = 0;
 		}
 
-		if (need_account) {
+		/*
+		 * If we had a drop_progress we need to verify the refs are set
+		 * as expected.  If we find our ref then we know that from here
+		 * on out everything should be correct, and we can clear the
+		 * ->restarted flag.
+		 */
+		if (wc->restarted) {
+			ret = check_ref_exists(trans, root, bytenr, parent,
+					       level - 1);
+			if (ret < 0)
+				goto out_unlock;
+			if (ret == 0)
+				goto no_delete;
+			ret = 0;
+			wc->restarted = 0;
+		}
+
+		/*
+		 * Reloc tree doesn't contribute to qgroup numbers, and we have
+		 * already accounted them at merge time (replace_path),
+		 * thus we could skip expensive subtree trace here.
+		 */
+		if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID &&
+		    need_account) {
 			ret = btrfs_qgroup_trace_subtree(trans, next,
 							 generation, level - 1);
 			if (ret) {
@@ -8660,13 +4944,24 @@
 					     ret);
 			}
 		}
-		ret = btrfs_free_extent(trans, root, bytenr, blocksize,
-					parent, root->root_key.objectid,
-					level - 1, 0);
+
+		/*
+		 * We need to update the next key in our walk control so we can
+		 * update the drop_progress key accordingly.  We don't care if
+		 * find_next_key doesn't find a key because that means we're at
+		 * the end and are going to clean up now.
+		 */
+		wc->drop_level = level;
+		find_next_key(path, level, &wc->drop_progress);
+
+		btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, bytenr,
+				       fs_info->nodesize, parent);
+		btrfs_init_tree_ref(&ref, level - 1, root->root_key.objectid);
+		ret = btrfs_free_extent(trans, &ref);
 		if (ret)
 			goto out_unlock;
 	}
-
+no_delete:
 	*lookup_info = 1;
 	ret = 1;
 
@@ -8721,7 +5016,7 @@
 		if (!path->locks[level]) {
 			BUG_ON(level == 0);
 			btrfs_tree_lock(eb);
-			btrfs_set_lock_blocking(eb);
+			btrfs_set_lock_blocking_write(eb);
 			path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
 
 			ret = btrfs_lookup_extent_info(trans, fs_info,
@@ -8752,21 +5047,23 @@
 			else
 				ret = btrfs_dec_ref(trans, root, eb, 0);
 			BUG_ON(ret); /* -ENOMEM */
-			ret = btrfs_qgroup_trace_leaf_items(trans, eb);
-			if (ret) {
-				btrfs_err_rl(fs_info,
-					     "error %d accounting leaf items. Quota is out of sync, rescan required.",
+			if (is_fstree(root->root_key.objectid)) {
+				ret = btrfs_qgroup_trace_leaf_items(trans, eb);
+				if (ret) {
+					btrfs_err_rl(fs_info,
+	"error %d accounting leaf items, quota is out of sync, rescan required",
 					     ret);
+				}
 			}
 		}
-		/* make block locked assertion in clean_tree_block happy */
+		/* make block locked assertion in btrfs_clean_tree_block happy */
 		if (!path->locks[level] &&
 		    btrfs_header_generation(eb) == trans->transid) {
 			btrfs_tree_lock(eb);
-			btrfs_set_lock_blocking(eb);
+			btrfs_set_lock_blocking_write(eb);
 			path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
 		}
-		clean_tree_block(fs_info, eb);
+		btrfs_clean_tree_block(eb);
 	}
 
 	if (eb == root->node) {
@@ -8890,7 +5187,7 @@
 	int level;
 	bool root_dropped = false;
 
-	btrfs_debug(fs_info, "Drop subvolume %llu", root->objectid);
+	btrfs_debug(fs_info, "Drop subvolume %llu", root->root_key.objectid);
 
 	path = btrfs_alloc_path();
 	if (!path) {
@@ -8911,13 +5208,26 @@
 		goto out_free;
 	}
 
+	err = btrfs_run_delayed_items(trans);
+	if (err)
+		goto out_end_trans;
+
 	if (block_rsv)
 		trans->block_rsv = block_rsv;
 
+	/*
+	 * This will help us catch people modifying the fs tree while we're
+	 * dropping it.  It is unsafe to mess with the fs tree while it's being
+	 * dropped as we unlock the root node and parent nodes as we walk down
+	 * the tree, assuming nothing will change.  If something does change
+	 * then we'll have stale information and drop references to blocks we've
+	 * already dropped.
+	 */
+	set_bit(BTRFS_ROOT_DELETING, &root->state);
 	if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
 		level = btrfs_header_level(root->node);
 		path->nodes[level] = btrfs_lock_root_node(root);
-		btrfs_set_lock_blocking(path->nodes[level]);
+		btrfs_set_lock_blocking_write(path->nodes[level]);
 		path->slots[level] = 0;
 		path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
 		memset(&wc->update_progress, 0,
@@ -8947,7 +5257,7 @@
 		level = btrfs_header_level(root->node);
 		while (1) {
 			btrfs_tree_lock(path->nodes[level]);
-			btrfs_set_lock_blocking(path->nodes[level]);
+			btrfs_set_lock_blocking_write(path->nodes[level]);
 			path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
 
 			ret = btrfs_lookup_extent_info(trans, fs_info,
@@ -8970,6 +5280,7 @@
 		}
 	}
 
+	wc->restarted = test_bit(BTRFS_ROOT_DEAD_TREE, &root->state);
 	wc->level = level;
 	wc->shared_level = -1;
 	wc->stage = DROP_REFERENCE;
@@ -8997,12 +5308,14 @@
 		}
 
 		if (wc->stage == DROP_REFERENCE) {
-			level = wc->level;
-			btrfs_node_key(path->nodes[level],
-				       &root_item->drop_progress,
-				       path->slots[level]);
-			root_item->drop_level = level;
+			wc->drop_level = wc->level;
+			btrfs_node_key_to_cpu(path->nodes[wc->drop_level],
+					      &wc->drop_progress,
+					      path->slots[wc->drop_level]);
 		}
+		btrfs_cpu_key_to_disk(&root_item->drop_progress,
+				      &wc->drop_progress);
+		root_item->drop_level = wc->drop_level;
 
 		BUG_ON(wc->level == 0);
 		if (btrfs_should_end_transaction(trans) ||
@@ -9161,177 +5474,6 @@
 	return ret;
 }
 
-static u64 update_block_group_flags(struct btrfs_fs_info *fs_info, u64 flags)
-{
-	u64 num_devices;
-	u64 stripped;
-
-	/*
-	 * if restripe for this chunk_type is on pick target profile and
-	 * return, otherwise do the usual balance
-	 */
-	stripped = get_restripe_target(fs_info, flags);
-	if (stripped)
-		return extended_to_chunk(stripped);
-
-	num_devices = fs_info->fs_devices->rw_devices;
-
-	stripped = BTRFS_BLOCK_GROUP_RAID0 |
-		BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6 |
-		BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
-
-	if (num_devices == 1) {
-		stripped |= BTRFS_BLOCK_GROUP_DUP;
-		stripped = flags & ~stripped;
-
-		/* turn raid0 into single device chunks */
-		if (flags & BTRFS_BLOCK_GROUP_RAID0)
-			return stripped;
-
-		/* turn mirroring into duplication */
-		if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
-			     BTRFS_BLOCK_GROUP_RAID10))
-			return stripped | BTRFS_BLOCK_GROUP_DUP;
-	} else {
-		/* they already had raid on here, just return */
-		if (flags & stripped)
-			return flags;
-
-		stripped |= BTRFS_BLOCK_GROUP_DUP;
-		stripped = flags & ~stripped;
-
-		/* switch duplicated blocks with raid1 */
-		if (flags & BTRFS_BLOCK_GROUP_DUP)
-			return stripped | BTRFS_BLOCK_GROUP_RAID1;
-
-		/* this is drive concat, leave it alone */
-	}
-
-	return flags;
-}
-
-static int inc_block_group_ro(struct btrfs_block_group_cache *cache, int force)
-{
-	struct btrfs_space_info *sinfo = cache->space_info;
-	u64 num_bytes;
-	u64 min_allocable_bytes;
-	int ret = -ENOSPC;
-
-	/*
-	 * We need some metadata space and system metadata space for
-	 * allocating chunks in some corner cases until we force to set
-	 * it to be readonly.
-	 */
-	if ((sinfo->flags &
-	     (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA)) &&
-	    !force)
-		min_allocable_bytes = SZ_1M;
-	else
-		min_allocable_bytes = 0;
-
-	spin_lock(&sinfo->lock);
-	spin_lock(&cache->lock);
-
-	if (cache->ro) {
-		cache->ro++;
-		ret = 0;
-		goto out;
-	}
-
-	num_bytes = cache->key.offset - cache->reserved - cache->pinned -
-		    cache->bytes_super - btrfs_block_group_used(&cache->item);
-
-	if (btrfs_space_info_used(sinfo, true) + num_bytes +
-	    min_allocable_bytes <= sinfo->total_bytes) {
-		sinfo->bytes_readonly += num_bytes;
-		cache->ro++;
-		list_add_tail(&cache->ro_list, &sinfo->ro_bgs);
-		ret = 0;
-	}
-out:
-	spin_unlock(&cache->lock);
-	spin_unlock(&sinfo->lock);
-	return ret;
-}
-
-int btrfs_inc_block_group_ro(struct btrfs_block_group_cache *cache)
-
-{
-	struct btrfs_fs_info *fs_info = cache->fs_info;
-	struct btrfs_trans_handle *trans;
-	u64 alloc_flags;
-	int ret;
-
-again:
-	trans = btrfs_join_transaction(fs_info->extent_root);
-	if (IS_ERR(trans))
-		return PTR_ERR(trans);
-
-	/*
-	 * we're not allowed to set block groups readonly after the dirty
-	 * block groups cache has started writing.  If it already started,
-	 * back off and let this transaction commit
-	 */
-	mutex_lock(&fs_info->ro_block_group_mutex);
-	if (test_bit(BTRFS_TRANS_DIRTY_BG_RUN, &trans->transaction->flags)) {
-		u64 transid = trans->transid;
-
-		mutex_unlock(&fs_info->ro_block_group_mutex);
-		btrfs_end_transaction(trans);
-
-		ret = btrfs_wait_for_commit(fs_info, transid);
-		if (ret)
-			return ret;
-		goto again;
-	}
-
-	/*
-	 * if we are changing raid levels, try to allocate a corresponding
-	 * block group with the new raid level.
-	 */
-	alloc_flags = update_block_group_flags(fs_info, cache->flags);
-	if (alloc_flags != cache->flags) {
-		ret = do_chunk_alloc(trans, alloc_flags,
-				     CHUNK_ALLOC_FORCE);
-		/*
-		 * ENOSPC is allowed here, we may have enough space
-		 * already allocated at the new raid level to
-		 * carry on
-		 */
-		if (ret == -ENOSPC)
-			ret = 0;
-		if (ret < 0)
-			goto out;
-	}
-
-	ret = inc_block_group_ro(cache, 0);
-	if (!ret)
-		goto out;
-	alloc_flags = get_alloc_profile(fs_info, cache->space_info->flags);
-	ret = do_chunk_alloc(trans, alloc_flags, CHUNK_ALLOC_FORCE);
-	if (ret < 0)
-		goto out;
-	ret = inc_block_group_ro(cache, 0);
-out:
-	if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
-		alloc_flags = update_block_group_flags(fs_info, cache->flags);
-		mutex_lock(&fs_info->chunk_mutex);
-		check_system_chunk(trans, alloc_flags);
-		mutex_unlock(&fs_info->chunk_mutex);
-	}
-	mutex_unlock(&fs_info->ro_block_group_mutex);
-
-	btrfs_end_transaction(trans);
-	return ret;
-}
-
-int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, u64 type)
-{
-	u64 alloc_flags = get_alloc_profile(trans->fs_info, type);
-
-	return do_chunk_alloc(trans, alloc_flags, CHUNK_ALLOC_FORCE);
-}
-
 /*
  * helper to account the unused space of all the readonly block group in the
  * space_info. takes mirrors into account.
@@ -9367,1397 +5509,6 @@
 	return free_bytes;
 }
 
-void btrfs_dec_block_group_ro(struct btrfs_block_group_cache *cache)
-{
-	struct btrfs_space_info *sinfo = cache->space_info;
-	u64 num_bytes;
-
-	BUG_ON(!cache->ro);
-
-	spin_lock(&sinfo->lock);
-	spin_lock(&cache->lock);
-	if (!--cache->ro) {
-		num_bytes = cache->key.offset - cache->reserved -
-			    cache->pinned - cache->bytes_super -
-			    btrfs_block_group_used(&cache->item);
-		sinfo->bytes_readonly -= num_bytes;
-		list_del_init(&cache->ro_list);
-	}
-	spin_unlock(&cache->lock);
-	spin_unlock(&sinfo->lock);
-}
-
-/*
- * checks to see if its even possible to relocate this block group.
- *
- * @return - -1 if it's not a good idea to relocate this block group, 0 if its
- * ok to go ahead and try.
- */
-int btrfs_can_relocate(struct btrfs_fs_info *fs_info, u64 bytenr)
-{
-	struct btrfs_root *root = fs_info->extent_root;
-	struct btrfs_block_group_cache *block_group;
-	struct btrfs_space_info *space_info;
-	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
-	struct btrfs_device *device;
-	struct btrfs_trans_handle *trans;
-	u64 min_free;
-	u64 dev_min = 1;
-	u64 dev_nr = 0;
-	u64 target;
-	int debug;
-	int index;
-	int full = 0;
-	int ret = 0;
-
-	debug = btrfs_test_opt(fs_info, ENOSPC_DEBUG);
-
-	block_group = btrfs_lookup_block_group(fs_info, bytenr);
-
-	/* odd, couldn't find the block group, leave it alone */
-	if (!block_group) {
-		if (debug)
-			btrfs_warn(fs_info,
-				   "can't find block group for bytenr %llu",
-				   bytenr);
-		return -1;
-	}
-
-	min_free = btrfs_block_group_used(&block_group->item);
-
-	/* no bytes used, we're good */
-	if (!min_free)
-		goto out;
-
-	space_info = block_group->space_info;
-	spin_lock(&space_info->lock);
-
-	full = space_info->full;
-
-	/*
-	 * if this is the last block group we have in this space, we can't
-	 * relocate it unless we're able to allocate a new chunk below.
-	 *
-	 * Otherwise, we need to make sure we have room in the space to handle
-	 * all of the extents from this block group.  If we can, we're good
-	 */
-	if ((space_info->total_bytes != block_group->key.offset) &&
-	    (btrfs_space_info_used(space_info, false) + min_free <
-	     space_info->total_bytes)) {
-		spin_unlock(&space_info->lock);
-		goto out;
-	}
-	spin_unlock(&space_info->lock);
-
-	/*
-	 * ok we don't have enough space, but maybe we have free space on our
-	 * devices to allocate new chunks for relocation, so loop through our
-	 * alloc devices and guess if we have enough space.  if this block
-	 * group is going to be restriped, run checks against the target
-	 * profile instead of the current one.
-	 */
-	ret = -1;
-
-	/*
-	 * index:
-	 *      0: raid10
-	 *      1: raid1
-	 *      2: dup
-	 *      3: raid0
-	 *      4: single
-	 */
-	target = get_restripe_target(fs_info, block_group->flags);
-	if (target) {
-		index = btrfs_bg_flags_to_raid_index(extended_to_chunk(target));
-	} else {
-		/*
-		 * this is just a balance, so if we were marked as full
-		 * we know there is no space for a new chunk
-		 */
-		if (full) {
-			if (debug)
-				btrfs_warn(fs_info,
-					   "no space to alloc new chunk for block group %llu",
-					   block_group->key.objectid);
-			goto out;
-		}
-
-		index = btrfs_bg_flags_to_raid_index(block_group->flags);
-	}
-
-	if (index == BTRFS_RAID_RAID10) {
-		dev_min = 4;
-		/* Divide by 2 */
-		min_free >>= 1;
-	} else if (index == BTRFS_RAID_RAID1) {
-		dev_min = 2;
-	} else if (index == BTRFS_RAID_DUP) {
-		/* Multiply by 2 */
-		min_free <<= 1;
-	} else if (index == BTRFS_RAID_RAID0) {
-		dev_min = fs_devices->rw_devices;
-		min_free = div64_u64(min_free, dev_min);
-	}
-
-	/* We need to do this so that we can look at pending chunks */
-	trans = btrfs_join_transaction(root);
-	if (IS_ERR(trans)) {
-		ret = PTR_ERR(trans);
-		goto out;
-	}
-
-	mutex_lock(&fs_info->chunk_mutex);
-	list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
-		u64 dev_offset;
-
-		/*
-		 * check to make sure we can actually find a chunk with enough
-		 * space to fit our block group in.
-		 */
-		if (device->total_bytes > device->bytes_used + min_free &&
-		    !test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
-			ret = find_free_dev_extent(trans, device, min_free,
-						   &dev_offset, NULL);
-			if (!ret)
-				dev_nr++;
-
-			if (dev_nr >= dev_min)
-				break;
-
-			ret = -1;
-		}
-	}
-	if (debug && ret == -1)
-		btrfs_warn(fs_info,
-			   "no space to allocate a new chunk for block group %llu",
-			   block_group->key.objectid);
-	mutex_unlock(&fs_info->chunk_mutex);
-	btrfs_end_transaction(trans);
-out:
-	btrfs_put_block_group(block_group);
-	return ret;
-}
-
-static int find_first_block_group(struct btrfs_fs_info *fs_info,
-				  struct btrfs_path *path,
-				  struct btrfs_key *key)
-{
-	struct btrfs_root *root = fs_info->extent_root;
-	int ret = 0;
-	struct btrfs_key found_key;
-	struct extent_buffer *leaf;
-	struct btrfs_block_group_item bg;
-	u64 flags;
-	int slot;
-
-	ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
-	if (ret < 0)
-		goto out;
-
-	while (1) {
-		slot = path->slots[0];
-		leaf = path->nodes[0];
-		if (slot >= btrfs_header_nritems(leaf)) {
-			ret = btrfs_next_leaf(root, path);
-			if (ret == 0)
-				continue;
-			if (ret < 0)
-				goto out;
-			break;
-		}
-		btrfs_item_key_to_cpu(leaf, &found_key, slot);
-
-		if (found_key.objectid >= key->objectid &&
-		    found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
-			struct extent_map_tree *em_tree;
-			struct extent_map *em;
-
-			em_tree = &root->fs_info->mapping_tree.map_tree;
-			read_lock(&em_tree->lock);
-			em = lookup_extent_mapping(em_tree, found_key.objectid,
-						   found_key.offset);
-			read_unlock(&em_tree->lock);
-			if (!em) {
-				btrfs_err(fs_info,
-			"logical %llu len %llu found bg but no related chunk",
-					  found_key.objectid, found_key.offset);
-				ret = -ENOENT;
-			} else if (em->start != found_key.objectid ||
-				   em->len != found_key.offset) {
-				btrfs_err(fs_info,
-		"block group %llu len %llu mismatch with chunk %llu len %llu",
-					  found_key.objectid, found_key.offset,
-					  em->start, em->len);
-				ret = -EUCLEAN;
-			} else {
-				read_extent_buffer(leaf, &bg,
-					btrfs_item_ptr_offset(leaf, slot),
-					sizeof(bg));
-				flags = btrfs_block_group_flags(&bg) &
-					BTRFS_BLOCK_GROUP_TYPE_MASK;
-
-				if (flags != (em->map_lookup->type &
-					      BTRFS_BLOCK_GROUP_TYPE_MASK)) {
-					btrfs_err(fs_info,
-"block group %llu len %llu type flags 0x%llx mismatch with chunk type flags 0x%llx",
-						found_key.objectid,
-						found_key.offset, flags,
-						(BTRFS_BLOCK_GROUP_TYPE_MASK &
-						 em->map_lookup->type));
-					ret = -EUCLEAN;
-				} else {
-					ret = 0;
-				}
-			}
-			free_extent_map(em);
-			goto out;
-		}
-		path->slots[0]++;
-	}
-out:
-	return ret;
-}
-
-void btrfs_put_block_group_cache(struct btrfs_fs_info *info)
-{
-	struct btrfs_block_group_cache *block_group;
-	u64 last = 0;
-
-	while (1) {
-		struct inode *inode;
-
-		block_group = btrfs_lookup_first_block_group(info, last);
-		while (block_group) {
-			wait_block_group_cache_done(block_group);
-			spin_lock(&block_group->lock);
-			if (block_group->iref)
-				break;
-			spin_unlock(&block_group->lock);
-			block_group = next_block_group(info, block_group);
-		}
-		if (!block_group) {
-			if (last == 0)
-				break;
-			last = 0;
-			continue;
-		}
-
-		inode = block_group->inode;
-		block_group->iref = 0;
-		block_group->inode = NULL;
-		spin_unlock(&block_group->lock);
-		ASSERT(block_group->io_ctl.inode == NULL);
-		iput(inode);
-		last = block_group->key.objectid + block_group->key.offset;
-		btrfs_put_block_group(block_group);
-	}
-}
-
-/*
- * Must be called only after stopping all workers, since we could have block
- * group caching kthreads running, and therefore they could race with us if we
- * freed the block groups before stopping them.
- */
-int btrfs_free_block_groups(struct btrfs_fs_info *info)
-{
-	struct btrfs_block_group_cache *block_group;
-	struct btrfs_space_info *space_info;
-	struct btrfs_caching_control *caching_ctl;
-	struct rb_node *n;
-
-	down_write(&info->commit_root_sem);
-	while (!list_empty(&info->caching_block_groups)) {
-		caching_ctl = list_entry(info->caching_block_groups.next,
-					 struct btrfs_caching_control, list);
-		list_del(&caching_ctl->list);
-		put_caching_control(caching_ctl);
-	}
-	up_write(&info->commit_root_sem);
-
-	spin_lock(&info->unused_bgs_lock);
-	while (!list_empty(&info->unused_bgs)) {
-		block_group = list_first_entry(&info->unused_bgs,
-					       struct btrfs_block_group_cache,
-					       bg_list);
-		list_del_init(&block_group->bg_list);
-		btrfs_put_block_group(block_group);
-	}
-	spin_unlock(&info->unused_bgs_lock);
-
-	spin_lock(&info->block_group_cache_lock);
-	while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
-		block_group = rb_entry(n, struct btrfs_block_group_cache,
-				       cache_node);
-		rb_erase(&block_group->cache_node,
-			 &info->block_group_cache_tree);
-		RB_CLEAR_NODE(&block_group->cache_node);
-		spin_unlock(&info->block_group_cache_lock);
-
-		down_write(&block_group->space_info->groups_sem);
-		list_del(&block_group->list);
-		up_write(&block_group->space_info->groups_sem);
-
-		/*
-		 * We haven't cached this block group, which means we could
-		 * possibly have excluded extents on this block group.
-		 */
-		if (block_group->cached == BTRFS_CACHE_NO ||
-		    block_group->cached == BTRFS_CACHE_ERROR)
-			free_excluded_extents(block_group);
-
-		btrfs_remove_free_space_cache(block_group);
-		ASSERT(block_group->cached != BTRFS_CACHE_STARTED);
-		ASSERT(list_empty(&block_group->dirty_list));
-		ASSERT(list_empty(&block_group->io_list));
-		ASSERT(list_empty(&block_group->bg_list));
-		ASSERT(atomic_read(&block_group->count) == 1);
-		btrfs_put_block_group(block_group);
-
-		spin_lock(&info->block_group_cache_lock);
-	}
-	spin_unlock(&info->block_group_cache_lock);
-
-	/* now that all the block groups are freed, go through and
-	 * free all the space_info structs.  This is only called during
-	 * the final stages of unmount, and so we know nobody is
-	 * using them.  We call synchronize_rcu() once before we start,
-	 * just to be on the safe side.
-	 */
-	synchronize_rcu();
-
-	release_global_block_rsv(info);
-
-	while (!list_empty(&info->space_info)) {
-		int i;
-
-		space_info = list_entry(info->space_info.next,
-					struct btrfs_space_info,
-					list);
-
-		/*
-		 * Do not hide this behind enospc_debug, this is actually
-		 * important and indicates a real bug if this happens.
-		 */
-		if (WARN_ON(space_info->bytes_pinned > 0 ||
-			    space_info->bytes_reserved > 0 ||
-			    space_info->bytes_may_use > 0))
-			dump_space_info(info, space_info, 0, 0);
-		list_del(&space_info->list);
-		for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
-			struct kobject *kobj;
-			kobj = space_info->block_group_kobjs[i];
-			space_info->block_group_kobjs[i] = NULL;
-			if (kobj) {
-				kobject_del(kobj);
-				kobject_put(kobj);
-			}
-		}
-		kobject_del(&space_info->kobj);
-		kobject_put(&space_info->kobj);
-	}
-	return 0;
-}
-
-/* link_block_group will queue up kobjects to add when we're reclaim-safe */
-void btrfs_add_raid_kobjects(struct btrfs_fs_info *fs_info)
-{
-	struct btrfs_space_info *space_info;
-	struct raid_kobject *rkobj;
-	LIST_HEAD(list);
-	int index;
-	int ret = 0;
-
-	spin_lock(&fs_info->pending_raid_kobjs_lock);
-	list_splice_init(&fs_info->pending_raid_kobjs, &list);
-	spin_unlock(&fs_info->pending_raid_kobjs_lock);
-
-	list_for_each_entry(rkobj, &list, list) {
-		space_info = __find_space_info(fs_info, rkobj->flags);
-		index = btrfs_bg_flags_to_raid_index(rkobj->flags);
-
-		ret = kobject_add(&rkobj->kobj, &space_info->kobj,
-				  "%s", get_raid_name(index));
-		if (ret) {
-			kobject_put(&rkobj->kobj);
-			break;
-		}
-	}
-	if (ret)
-		btrfs_warn(fs_info,
-			   "failed to add kobject for block cache, ignoring");
-}
-
-static void link_block_group(struct btrfs_block_group_cache *cache)
-{
-	struct btrfs_space_info *space_info = cache->space_info;
-	struct btrfs_fs_info *fs_info = cache->fs_info;
-	int index = btrfs_bg_flags_to_raid_index(cache->flags);
-	bool first = false;
-
-	down_write(&space_info->groups_sem);
-	if (list_empty(&space_info->block_groups[index]))
-		first = true;
-	list_add_tail(&cache->list, &space_info->block_groups[index]);
-	up_write(&space_info->groups_sem);
-
-	if (first) {
-		struct raid_kobject *rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
-		if (!rkobj) {
-			btrfs_warn(cache->fs_info,
-				"couldn't alloc memory for raid level kobject");
-			return;
-		}
-		rkobj->flags = cache->flags;
-		kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
-
-		spin_lock(&fs_info->pending_raid_kobjs_lock);
-		list_add_tail(&rkobj->list, &fs_info->pending_raid_kobjs);
-		spin_unlock(&fs_info->pending_raid_kobjs_lock);
-		space_info->block_group_kobjs[index] = &rkobj->kobj;
-	}
-}
-
-static struct btrfs_block_group_cache *
-btrfs_create_block_group_cache(struct btrfs_fs_info *fs_info,
-			       u64 start, u64 size)
-{
-	struct btrfs_block_group_cache *cache;
-
-	cache = kzalloc(sizeof(*cache), GFP_NOFS);
-	if (!cache)
-		return NULL;
-
-	cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl),
-					GFP_NOFS);
-	if (!cache->free_space_ctl) {
-		kfree(cache);
-		return NULL;
-	}
-
-	cache->key.objectid = start;
-	cache->key.offset = size;
-	cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
-
-	cache->fs_info = fs_info;
-	cache->full_stripe_len = btrfs_full_stripe_len(fs_info, start);
-	set_free_space_tree_thresholds(cache);
-
-	atomic_set(&cache->count, 1);
-	spin_lock_init(&cache->lock);
-	init_rwsem(&cache->data_rwsem);
-	INIT_LIST_HEAD(&cache->list);
-	INIT_LIST_HEAD(&cache->cluster_list);
-	INIT_LIST_HEAD(&cache->bg_list);
-	INIT_LIST_HEAD(&cache->ro_list);
-	INIT_LIST_HEAD(&cache->dirty_list);
-	INIT_LIST_HEAD(&cache->io_list);
-	btrfs_init_free_space_ctl(cache);
-	atomic_set(&cache->trimming, 0);
-	mutex_init(&cache->free_space_lock);
-	btrfs_init_full_stripe_locks_tree(&cache->full_stripe_locks_root);
-
-	return cache;
-}
-
-
-/*
- * Iterate all chunks and verify that each of them has the corresponding block
- * group
- */
-static int check_chunk_block_group_mappings(struct btrfs_fs_info *fs_info)
-{
-	struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
-	struct extent_map *em;
-	struct btrfs_block_group_cache *bg;
-	u64 start = 0;
-	int ret = 0;
-
-	while (1) {
-		read_lock(&map_tree->map_tree.lock);
-		/*
-		 * lookup_extent_mapping will return the first extent map
-		 * intersecting the range, so setting @len to 1 is enough to
-		 * get the first chunk.
-		 */
-		em = lookup_extent_mapping(&map_tree->map_tree, start, 1);
-		read_unlock(&map_tree->map_tree.lock);
-		if (!em)
-			break;
-
-		bg = btrfs_lookup_block_group(fs_info, em->start);
-		if (!bg) {
-			btrfs_err(fs_info,
-	"chunk start=%llu len=%llu doesn't have corresponding block group",
-				     em->start, em->len);
-			ret = -EUCLEAN;
-			free_extent_map(em);
-			break;
-		}
-		if (bg->key.objectid != em->start ||
-		    bg->key.offset != em->len ||
-		    (bg->flags & BTRFS_BLOCK_GROUP_TYPE_MASK) !=
-		    (em->map_lookup->type & BTRFS_BLOCK_GROUP_TYPE_MASK)) {
-			btrfs_err(fs_info,
-"chunk start=%llu len=%llu flags=0x%llx doesn't match block group start=%llu len=%llu flags=0x%llx",
-				em->start, em->len,
-				em->map_lookup->type & BTRFS_BLOCK_GROUP_TYPE_MASK,
-				bg->key.objectid, bg->key.offset,
-				bg->flags & BTRFS_BLOCK_GROUP_TYPE_MASK);
-			ret = -EUCLEAN;
-			free_extent_map(em);
-			btrfs_put_block_group(bg);
-			break;
-		}
-		start = em->start + em->len;
-		free_extent_map(em);
-		btrfs_put_block_group(bg);
-	}
-	return ret;
-}
-
-int btrfs_read_block_groups(struct btrfs_fs_info *info)
-{
-	struct btrfs_path *path;
-	int ret;
-	struct btrfs_block_group_cache *cache;
-	struct btrfs_space_info *space_info;
-	struct btrfs_key key;
-	struct btrfs_key found_key;
-	struct extent_buffer *leaf;
-	int need_clear = 0;
-	u64 cache_gen;
-	u64 feature;
-	int mixed;
-
-	feature = btrfs_super_incompat_flags(info->super_copy);
-	mixed = !!(feature & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS);
-
-	key.objectid = 0;
-	key.offset = 0;
-	key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
-	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOMEM;
-	path->reada = READA_FORWARD;
-
-	cache_gen = btrfs_super_cache_generation(info->super_copy);
-	if (btrfs_test_opt(info, SPACE_CACHE) &&
-	    btrfs_super_generation(info->super_copy) != cache_gen)
-		need_clear = 1;
-	if (btrfs_test_opt(info, CLEAR_CACHE))
-		need_clear = 1;
-
-	while (1) {
-		ret = find_first_block_group(info, path, &key);
-		if (ret > 0)
-			break;
-		if (ret != 0)
-			goto error;
-
-		leaf = path->nodes[0];
-		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
-
-		cache = btrfs_create_block_group_cache(info, found_key.objectid,
-						       found_key.offset);
-		if (!cache) {
-			ret = -ENOMEM;
-			goto error;
-		}
-
-		if (need_clear) {
-			/*
-			 * When we mount with old space cache, we need to
-			 * set BTRFS_DC_CLEAR and set dirty flag.
-			 *
-			 * a) Setting 'BTRFS_DC_CLEAR' makes sure that we
-			 *    truncate the old free space cache inode and
-			 *    setup a new one.
-			 * b) Setting 'dirty flag' makes sure that we flush
-			 *    the new space cache info onto disk.
-			 */
-			if (btrfs_test_opt(info, SPACE_CACHE))
-				cache->disk_cache_state = BTRFS_DC_CLEAR;
-		}
-
-		read_extent_buffer(leaf, &cache->item,
-				   btrfs_item_ptr_offset(leaf, path->slots[0]),
-				   sizeof(cache->item));
-		cache->flags = btrfs_block_group_flags(&cache->item);
-		if (!mixed &&
-		    ((cache->flags & BTRFS_BLOCK_GROUP_METADATA) &&
-		    (cache->flags & BTRFS_BLOCK_GROUP_DATA))) {
-			btrfs_err(info,
-"bg %llu is a mixed block group but filesystem hasn't enabled mixed block groups",
-				  cache->key.objectid);
-			ret = -EINVAL;
-			goto error;
-		}
-
-		key.objectid = found_key.objectid + found_key.offset;
-		btrfs_release_path(path);
-
-		/*
-		 * We need to exclude the super stripes now so that the space
-		 * info has super bytes accounted for, otherwise we'll think
-		 * we have more space than we actually do.
-		 */
-		ret = exclude_super_stripes(cache);
-		if (ret) {
-			/*
-			 * We may have excluded something, so call this just in
-			 * case.
-			 */
-			free_excluded_extents(cache);
-			btrfs_put_block_group(cache);
-			goto error;
-		}
-
-		/*
-		 * check for two cases, either we are full, and therefore
-		 * don't need to bother with the caching work since we won't
-		 * find any space, or we are empty, and we can just add all
-		 * the space in and be done with it.  This saves us _alot_ of
-		 * time, particularly in the full case.
-		 */
-		if (found_key.offset == btrfs_block_group_used(&cache->item)) {
-			cache->last_byte_to_unpin = (u64)-1;
-			cache->cached = BTRFS_CACHE_FINISHED;
-			free_excluded_extents(cache);
-		} else if (btrfs_block_group_used(&cache->item) == 0) {
-			cache->last_byte_to_unpin = (u64)-1;
-			cache->cached = BTRFS_CACHE_FINISHED;
-			add_new_free_space(cache, found_key.objectid,
-					   found_key.objectid +
-					   found_key.offset);
-			free_excluded_extents(cache);
-		}
-
-		ret = btrfs_add_block_group_cache(info, cache);
-		if (ret) {
-			btrfs_remove_free_space_cache(cache);
-			btrfs_put_block_group(cache);
-			goto error;
-		}
-
-		trace_btrfs_add_block_group(info, cache, 0);
-		update_space_info(info, cache->flags, found_key.offset,
-				  btrfs_block_group_used(&cache->item),
-				  cache->bytes_super, &space_info);
-
-		cache->space_info = space_info;
-
-		link_block_group(cache);
-
-		set_avail_alloc_bits(info, cache->flags);
-		if (btrfs_chunk_readonly(info, cache->key.objectid)) {
-			inc_block_group_ro(cache, 1);
-		} else if (btrfs_block_group_used(&cache->item) == 0) {
-			ASSERT(list_empty(&cache->bg_list));
-			btrfs_mark_bg_unused(cache);
-		}
-	}
-
-	list_for_each_entry_rcu(space_info, &info->space_info, list) {
-		if (!(get_alloc_profile(info, space_info->flags) &
-		      (BTRFS_BLOCK_GROUP_RAID10 |
-		       BTRFS_BLOCK_GROUP_RAID1 |
-		       BTRFS_BLOCK_GROUP_RAID5 |
-		       BTRFS_BLOCK_GROUP_RAID6 |
-		       BTRFS_BLOCK_GROUP_DUP)))
-			continue;
-		/*
-		 * avoid allocating from un-mirrored block group if there are
-		 * mirrored block groups.
-		 */
-		list_for_each_entry(cache,
-				&space_info->block_groups[BTRFS_RAID_RAID0],
-				list)
-			inc_block_group_ro(cache, 1);
-		list_for_each_entry(cache,
-				&space_info->block_groups[BTRFS_RAID_SINGLE],
-				list)
-			inc_block_group_ro(cache, 1);
-	}
-
-	btrfs_add_raid_kobjects(info);
-	init_global_block_rsv(info);
-	ret = check_chunk_block_group_mappings(info);
-error:
-	btrfs_free_path(path);
-	return ret;
-}
-
-void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans)
-{
-	struct btrfs_fs_info *fs_info = trans->fs_info;
-	struct btrfs_block_group_cache *block_group;
-	struct btrfs_root *extent_root = fs_info->extent_root;
-	struct btrfs_block_group_item item;
-	struct btrfs_key key;
-	int ret = 0;
-
-	if (!trans->can_flush_pending_bgs)
-		return;
-
-	while (!list_empty(&trans->new_bgs)) {
-		block_group = list_first_entry(&trans->new_bgs,
-					       struct btrfs_block_group_cache,
-					       bg_list);
-		if (ret)
-			goto next;
-
-		spin_lock(&block_group->lock);
-		memcpy(&item, &block_group->item, sizeof(item));
-		memcpy(&key, &block_group->key, sizeof(key));
-		spin_unlock(&block_group->lock);
-
-		ret = btrfs_insert_item(trans, extent_root, &key, &item,
-					sizeof(item));
-		if (ret)
-			btrfs_abort_transaction(trans, ret);
-		ret = btrfs_finish_chunk_alloc(trans, key.objectid, key.offset);
-		if (ret)
-			btrfs_abort_transaction(trans, ret);
-		add_block_group_free_space(trans, block_group);
-		/* already aborted the transaction if it failed. */
-next:
-		list_del_init(&block_group->bg_list);
-	}
-	btrfs_trans_release_chunk_metadata(trans);
-}
-
-int btrfs_make_block_group(struct btrfs_trans_handle *trans, u64 bytes_used,
-			   u64 type, u64 chunk_offset, u64 size)
-{
-	struct btrfs_fs_info *fs_info = trans->fs_info;
-	struct btrfs_block_group_cache *cache;
-	int ret;
-
-	btrfs_set_log_full_commit(fs_info, trans);
-
-	cache = btrfs_create_block_group_cache(fs_info, chunk_offset, size);
-	if (!cache)
-		return -ENOMEM;
-
-	btrfs_set_block_group_used(&cache->item, bytes_used);
-	btrfs_set_block_group_chunk_objectid(&cache->item,
-					     BTRFS_FIRST_CHUNK_TREE_OBJECTID);
-	btrfs_set_block_group_flags(&cache->item, type);
-
-	cache->flags = type;
-	cache->last_byte_to_unpin = (u64)-1;
-	cache->cached = BTRFS_CACHE_FINISHED;
-	cache->needs_free_space = 1;
-	ret = exclude_super_stripes(cache);
-	if (ret) {
-		/*
-		 * We may have excluded something, so call this just in
-		 * case.
-		 */
-		free_excluded_extents(cache);
-		btrfs_put_block_group(cache);
-		return ret;
-	}
-
-	add_new_free_space(cache, chunk_offset, chunk_offset + size);
-
-	free_excluded_extents(cache);
-
-#ifdef CONFIG_BTRFS_DEBUG
-	if (btrfs_should_fragment_free_space(cache)) {
-		u64 new_bytes_used = size - bytes_used;
-
-		bytes_used += new_bytes_used >> 1;
-		fragment_free_space(cache);
-	}
-#endif
-	/*
-	 * Ensure the corresponding space_info object is created and
-	 * assigned to our block group. We want our bg to be added to the rbtree
-	 * with its ->space_info set.
-	 */
-	cache->space_info = __find_space_info(fs_info, cache->flags);
-	ASSERT(cache->space_info);
-
-	ret = btrfs_add_block_group_cache(fs_info, cache);
-	if (ret) {
-		btrfs_remove_free_space_cache(cache);
-		btrfs_put_block_group(cache);
-		return ret;
-	}
-
-	/*
-	 * Now that our block group has its ->space_info set and is inserted in
-	 * the rbtree, update the space info's counters.
-	 */
-	trace_btrfs_add_block_group(fs_info, cache, 1);
-	update_space_info(fs_info, cache->flags, size, bytes_used,
-				cache->bytes_super, &cache->space_info);
-	update_global_block_rsv(fs_info);
-
-	link_block_group(cache);
-
-	list_add_tail(&cache->bg_list, &trans->new_bgs);
-
-	set_avail_alloc_bits(fs_info, type);
-	return 0;
-}
-
-static void clear_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
-{
-	u64 extra_flags = chunk_to_extended(flags) &
-				BTRFS_EXTENDED_PROFILE_MASK;
-
-	write_seqlock(&fs_info->profiles_lock);
-	if (flags & BTRFS_BLOCK_GROUP_DATA)
-		fs_info->avail_data_alloc_bits &= ~extra_flags;
-	if (flags & BTRFS_BLOCK_GROUP_METADATA)
-		fs_info->avail_metadata_alloc_bits &= ~extra_flags;
-	if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
-		fs_info->avail_system_alloc_bits &= ~extra_flags;
-	write_sequnlock(&fs_info->profiles_lock);
-}
-
-int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
-			     u64 group_start, struct extent_map *em)
-{
-	struct btrfs_fs_info *fs_info = trans->fs_info;
-	struct btrfs_root *root = fs_info->extent_root;
-	struct btrfs_path *path;
-	struct btrfs_block_group_cache *block_group;
-	struct btrfs_free_cluster *cluster;
-	struct btrfs_root *tree_root = fs_info->tree_root;
-	struct btrfs_key key;
-	struct inode *inode;
-	struct kobject *kobj = NULL;
-	int ret;
-	int index;
-	int factor;
-	struct btrfs_caching_control *caching_ctl = NULL;
-	bool remove_em;
-
-	block_group = btrfs_lookup_block_group(fs_info, group_start);
-	BUG_ON(!block_group);
-	BUG_ON(!block_group->ro);
-
-	trace_btrfs_remove_block_group(block_group);
-	/*
-	 * Free the reserved super bytes from this block group before
-	 * remove it.
-	 */
-	free_excluded_extents(block_group);
-	btrfs_free_ref_tree_range(fs_info, block_group->key.objectid,
-				  block_group->key.offset);
-
-	memcpy(&key, &block_group->key, sizeof(key));
-	index = btrfs_bg_flags_to_raid_index(block_group->flags);
-	factor = btrfs_bg_type_to_factor(block_group->flags);
-
-	/* make sure this block group isn't part of an allocation cluster */
-	cluster = &fs_info->data_alloc_cluster;
-	spin_lock(&cluster->refill_lock);
-	btrfs_return_cluster_to_free_space(block_group, cluster);
-	spin_unlock(&cluster->refill_lock);
-
-	/*
-	 * make sure this block group isn't part of a metadata
-	 * allocation cluster
-	 */
-	cluster = &fs_info->meta_alloc_cluster;
-	spin_lock(&cluster->refill_lock);
-	btrfs_return_cluster_to_free_space(block_group, cluster);
-	spin_unlock(&cluster->refill_lock);
-
-	path = btrfs_alloc_path();
-	if (!path) {
-		ret = -ENOMEM;
-		goto out;
-	}
-
-	/*
-	 * get the inode first so any iput calls done for the io_list
-	 * aren't the final iput (no unlinks allowed now)
-	 */
-	inode = lookup_free_space_inode(fs_info, block_group, path);
-
-	mutex_lock(&trans->transaction->cache_write_mutex);
-	/*
-	 * make sure our free spache cache IO is done before remove the
-	 * free space inode
-	 */
-	spin_lock(&trans->transaction->dirty_bgs_lock);
-	if (!list_empty(&block_group->io_list)) {
-		list_del_init(&block_group->io_list);
-
-		WARN_ON(!IS_ERR(inode) && inode != block_group->io_ctl.inode);
-
-		spin_unlock(&trans->transaction->dirty_bgs_lock);
-		btrfs_wait_cache_io(trans, block_group, path);
-		btrfs_put_block_group(block_group);
-		spin_lock(&trans->transaction->dirty_bgs_lock);
-	}
-
-	if (!list_empty(&block_group->dirty_list)) {
-		list_del_init(&block_group->dirty_list);
-		btrfs_put_block_group(block_group);
-	}
-	spin_unlock(&trans->transaction->dirty_bgs_lock);
-	mutex_unlock(&trans->transaction->cache_write_mutex);
-
-	if (!IS_ERR(inode)) {
-		ret = btrfs_orphan_add(trans, BTRFS_I(inode));
-		if (ret) {
-			btrfs_add_delayed_iput(inode);
-			goto out;
-		}
-		clear_nlink(inode);
-		/* One for the block groups ref */
-		spin_lock(&block_group->lock);
-		if (block_group->iref) {
-			block_group->iref = 0;
-			block_group->inode = NULL;
-			spin_unlock(&block_group->lock);
-			iput(inode);
-		} else {
-			spin_unlock(&block_group->lock);
-		}
-		/* One for our lookup ref */
-		btrfs_add_delayed_iput(inode);
-	}
-
-	key.objectid = BTRFS_FREE_SPACE_OBJECTID;
-	key.offset = block_group->key.objectid;
-	key.type = 0;
-
-	ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
-	if (ret < 0)
-		goto out;
-	if (ret > 0)
-		btrfs_release_path(path);
-	if (ret == 0) {
-		ret = btrfs_del_item(trans, tree_root, path);
-		if (ret)
-			goto out;
-		btrfs_release_path(path);
-	}
-
-	spin_lock(&fs_info->block_group_cache_lock);
-	rb_erase(&block_group->cache_node,
-		 &fs_info->block_group_cache_tree);
-	RB_CLEAR_NODE(&block_group->cache_node);
-
-	if (fs_info->first_logical_byte == block_group->key.objectid)
-		fs_info->first_logical_byte = (u64)-1;
-	spin_unlock(&fs_info->block_group_cache_lock);
-
-	down_write(&block_group->space_info->groups_sem);
-	/*
-	 * we must use list_del_init so people can check to see if they
-	 * are still on the list after taking the semaphore
-	 */
-	list_del_init(&block_group->list);
-	if (list_empty(&block_group->space_info->block_groups[index])) {
-		kobj = block_group->space_info->block_group_kobjs[index];
-		block_group->space_info->block_group_kobjs[index] = NULL;
-		clear_avail_alloc_bits(fs_info, block_group->flags);
-	}
-	up_write(&block_group->space_info->groups_sem);
-	if (kobj) {
-		kobject_del(kobj);
-		kobject_put(kobj);
-	}
-
-	if (block_group->has_caching_ctl)
-		caching_ctl = get_caching_control(block_group);
-	if (block_group->cached == BTRFS_CACHE_STARTED)
-		wait_block_group_cache_done(block_group);
-	if (block_group->has_caching_ctl) {
-		down_write(&fs_info->commit_root_sem);
-		if (!caching_ctl) {
-			struct btrfs_caching_control *ctl;
-
-			list_for_each_entry(ctl,
-				    &fs_info->caching_block_groups, list)
-				if (ctl->block_group == block_group) {
-					caching_ctl = ctl;
-					refcount_inc(&caching_ctl->count);
-					break;
-				}
-		}
-		if (caching_ctl)
-			list_del_init(&caching_ctl->list);
-		up_write(&fs_info->commit_root_sem);
-		if (caching_ctl) {
-			/* Once for the caching bgs list and once for us. */
-			put_caching_control(caching_ctl);
-			put_caching_control(caching_ctl);
-		}
-	}
-
-	spin_lock(&trans->transaction->dirty_bgs_lock);
-	if (!list_empty(&block_group->dirty_list)) {
-		WARN_ON(1);
-	}
-	if (!list_empty(&block_group->io_list)) {
-		WARN_ON(1);
-	}
-	spin_unlock(&trans->transaction->dirty_bgs_lock);
-	btrfs_remove_free_space_cache(block_group);
-
-	spin_lock(&block_group->space_info->lock);
-	list_del_init(&block_group->ro_list);
-
-	if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
-		WARN_ON(block_group->space_info->total_bytes
-			< block_group->key.offset);
-		WARN_ON(block_group->space_info->bytes_readonly
-			< block_group->key.offset);
-		WARN_ON(block_group->space_info->disk_total
-			< block_group->key.offset * factor);
-	}
-	block_group->space_info->total_bytes -= block_group->key.offset;
-	block_group->space_info->bytes_readonly -= block_group->key.offset;
-	block_group->space_info->disk_total -= block_group->key.offset * factor;
-
-	spin_unlock(&block_group->space_info->lock);
-
-	memcpy(&key, &block_group->key, sizeof(key));
-
-	mutex_lock(&fs_info->chunk_mutex);
-	if (!list_empty(&em->list)) {
-		/* We're in the transaction->pending_chunks list. */
-		free_extent_map(em);
-	}
-	spin_lock(&block_group->lock);
-	block_group->removed = 1;
-	/*
-	 * At this point trimming can't start on this block group, because we
-	 * removed the block group from the tree fs_info->block_group_cache_tree
-	 * so no one can't find it anymore and even if someone already got this
-	 * block group before we removed it from the rbtree, they have already
-	 * incremented block_group->trimming - if they didn't, they won't find
-	 * any free space entries because we already removed them all when we
-	 * called btrfs_remove_free_space_cache().
-	 *
-	 * And we must not remove the extent map from the fs_info->mapping_tree
-	 * to prevent the same logical address range and physical device space
-	 * ranges from being reused for a new block group. This is because our
-	 * fs trim operation (btrfs_trim_fs() / btrfs_ioctl_fitrim()) is
-	 * completely transactionless, so while it is trimming a range the
-	 * currently running transaction might finish and a new one start,
-	 * allowing for new block groups to be created that can reuse the same
-	 * physical device locations unless we take this special care.
-	 *
-	 * There may also be an implicit trim operation if the file system
-	 * is mounted with -odiscard. The same protections must remain
-	 * in place until the extents have been discarded completely when
-	 * the transaction commit has completed.
-	 */
-	remove_em = (atomic_read(&block_group->trimming) == 0);
-	/*
-	 * Make sure a trimmer task always sees the em in the pinned_chunks list
-	 * if it sees block_group->removed == 1 (needs to lock block_group->lock
-	 * before checking block_group->removed).
-	 */
-	if (!remove_em) {
-		/*
-		 * Our em might be in trans->transaction->pending_chunks which
-		 * is protected by fs_info->chunk_mutex ([lock|unlock]_chunks),
-		 * and so is the fs_info->pinned_chunks list.
-		 *
-		 * So at this point we must be holding the chunk_mutex to avoid
-		 * any races with chunk allocation (more specifically at
-		 * volumes.c:contains_pending_extent()), to ensure it always
-		 * sees the em, either in the pending_chunks list or in the
-		 * pinned_chunks list.
-		 */
-		list_move_tail(&em->list, &fs_info->pinned_chunks);
-	}
-	spin_unlock(&block_group->lock);
-
-	if (remove_em) {
-		struct extent_map_tree *em_tree;
-
-		em_tree = &fs_info->mapping_tree.map_tree;
-		write_lock(&em_tree->lock);
-		/*
-		 * The em might be in the pending_chunks list, so make sure the
-		 * chunk mutex is locked, since remove_extent_mapping() will
-		 * delete us from that list.
-		 */
-		remove_extent_mapping(em_tree, em);
-		write_unlock(&em_tree->lock);
-		/* once for the tree */
-		free_extent_map(em);
-	}
-
-	mutex_unlock(&fs_info->chunk_mutex);
-
-	ret = remove_block_group_free_space(trans, block_group);
-	if (ret)
-		goto out;
-
-	btrfs_put_block_group(block_group);
-	btrfs_put_block_group(block_group);
-
-	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
-	if (ret > 0)
-		ret = -EIO;
-	if (ret < 0)
-		goto out;
-
-	ret = btrfs_del_item(trans, root, path);
-out:
-	btrfs_free_path(path);
-	return ret;
-}
-
-struct btrfs_trans_handle *
-btrfs_start_trans_remove_block_group(struct btrfs_fs_info *fs_info,
-				     const u64 chunk_offset)
-{
-	struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree;
-	struct extent_map *em;
-	struct map_lookup *map;
-	unsigned int num_items;
-
-	read_lock(&em_tree->lock);
-	em = lookup_extent_mapping(em_tree, chunk_offset, 1);
-	read_unlock(&em_tree->lock);
-	ASSERT(em && em->start == chunk_offset);
-
-	/*
-	 * We need to reserve 3 + N units from the metadata space info in order
-	 * to remove a block group (done at btrfs_remove_chunk() and at
-	 * btrfs_remove_block_group()), which are used for:
-	 *
-	 * 1 unit for adding the free space inode's orphan (located in the tree
-	 * of tree roots).
-	 * 1 unit for deleting the block group item (located in the extent
-	 * tree).
-	 * 1 unit for deleting the free space item (located in tree of tree
-	 * roots).
-	 * N units for deleting N device extent items corresponding to each
-	 * stripe (located in the device tree).
-	 *
-	 * In order to remove a block group we also need to reserve units in the
-	 * system space info in order to update the chunk tree (update one or
-	 * more device items and remove one chunk item), but this is done at
-	 * btrfs_remove_chunk() through a call to check_system_chunk().
-	 */
-	map = em->map_lookup;
-	num_items = 3 + map->num_stripes;
-	free_extent_map(em);
-
-	return btrfs_start_transaction_fallback_global_rsv(fs_info->extent_root,
-							   num_items, 1);
-}
-
-/*
- * Process the unused_bgs list and remove any that don't have any allocated
- * space inside of them.
- */
-void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
-{
-	struct btrfs_block_group_cache *block_group;
-	struct btrfs_space_info *space_info;
-	struct btrfs_trans_handle *trans;
-	int ret = 0;
-
-	if (!test_bit(BTRFS_FS_OPEN, &fs_info->flags))
-		return;
-
-	spin_lock(&fs_info->unused_bgs_lock);
-	while (!list_empty(&fs_info->unused_bgs)) {
-		u64 start, end;
-		int trimming;
-
-		block_group = list_first_entry(&fs_info->unused_bgs,
-					       struct btrfs_block_group_cache,
-					       bg_list);
-		list_del_init(&block_group->bg_list);
-
-		space_info = block_group->space_info;
-
-		if (ret || btrfs_mixed_space_info(space_info)) {
-			btrfs_put_block_group(block_group);
-			continue;
-		}
-		spin_unlock(&fs_info->unused_bgs_lock);
-
-		mutex_lock(&fs_info->delete_unused_bgs_mutex);
-
-		/* Don't want to race with allocators so take the groups_sem */
-		down_write(&space_info->groups_sem);
-		spin_lock(&block_group->lock);
-		if (block_group->reserved || block_group->pinned ||
-		    btrfs_block_group_used(&block_group->item) ||
-		    block_group->ro ||
-		    list_is_singular(&block_group->list)) {
-			/*
-			 * We want to bail if we made new allocations or have
-			 * outstanding allocations in this block group.  We do
-			 * the ro check in case balance is currently acting on
-			 * this block group.
-			 */
-			trace_btrfs_skip_unused_block_group(block_group);
-			spin_unlock(&block_group->lock);
-			up_write(&space_info->groups_sem);
-			goto next;
-		}
-		spin_unlock(&block_group->lock);
-
-		/* We don't want to force the issue, only flip if it's ok. */
-		ret = inc_block_group_ro(block_group, 0);
-		up_write(&space_info->groups_sem);
-		if (ret < 0) {
-			ret = 0;
-			goto next;
-		}
-
-		/*
-		 * Want to do this before we do anything else so we can recover
-		 * properly if we fail to join the transaction.
-		 */
-		trans = btrfs_start_trans_remove_block_group(fs_info,
-						     block_group->key.objectid);
-		if (IS_ERR(trans)) {
-			btrfs_dec_block_group_ro(block_group);
-			ret = PTR_ERR(trans);
-			goto next;
-		}
-
-		/*
-		 * We could have pending pinned extents for this block group,
-		 * just delete them, we don't care about them anymore.
-		 */
-		start = block_group->key.objectid;
-		end = start + block_group->key.offset - 1;
-		/*
-		 * Hold the unused_bg_unpin_mutex lock to avoid racing with
-		 * btrfs_finish_extent_commit(). If we are at transaction N,
-		 * another task might be running finish_extent_commit() for the
-		 * previous transaction N - 1, and have seen a range belonging
-		 * to the block group in freed_extents[] before we were able to
-		 * clear the whole block group range from freed_extents[]. This
-		 * means that task can lookup for the block group after we
-		 * unpinned it from freed_extents[] and removed it, leading to
-		 * a BUG_ON() at btrfs_unpin_extent_range().
-		 */
-		mutex_lock(&fs_info->unused_bg_unpin_mutex);
-		ret = clear_extent_bits(&fs_info->freed_extents[0], start, end,
-				  EXTENT_DIRTY);
-		if (ret) {
-			mutex_unlock(&fs_info->unused_bg_unpin_mutex);
-			btrfs_dec_block_group_ro(block_group);
-			goto end_trans;
-		}
-		ret = clear_extent_bits(&fs_info->freed_extents[1], start, end,
-				  EXTENT_DIRTY);
-		if (ret) {
-			mutex_unlock(&fs_info->unused_bg_unpin_mutex);
-			btrfs_dec_block_group_ro(block_group);
-			goto end_trans;
-		}
-		mutex_unlock(&fs_info->unused_bg_unpin_mutex);
-
-		/* Reset pinned so btrfs_put_block_group doesn't complain */
-		spin_lock(&space_info->lock);
-		spin_lock(&block_group->lock);
-
-		space_info->bytes_pinned -= block_group->pinned;
-		space_info->bytes_readonly += block_group->pinned;
-		percpu_counter_add_batch(&space_info->total_bytes_pinned,
-				   -block_group->pinned,
-				   BTRFS_TOTAL_BYTES_PINNED_BATCH);
-		block_group->pinned = 0;
-
-		spin_unlock(&block_group->lock);
-		spin_unlock(&space_info->lock);
-
-		/* DISCARD can flip during remount */
-		trimming = btrfs_test_opt(fs_info, DISCARD);
-
-		/* Implicit trim during transaction commit. */
-		if (trimming)
-			btrfs_get_block_group_trimming(block_group);
-
-		/*
-		 * Btrfs_remove_chunk will abort the transaction if things go
-		 * horribly wrong.
-		 */
-		ret = btrfs_remove_chunk(trans, block_group->key.objectid);
-
-		if (ret) {
-			if (trimming)
-				btrfs_put_block_group_trimming(block_group);
-			goto end_trans;
-		}
-
-		/*
-		 * If we're not mounted with -odiscard, we can just forget
-		 * about this block group. Otherwise we'll need to wait
-		 * until transaction commit to do the actual discard.
-		 */
-		if (trimming) {
-			spin_lock(&fs_info->unused_bgs_lock);
-			/*
-			 * A concurrent scrub might have added us to the list
-			 * fs_info->unused_bgs, so use a list_move operation
-			 * to add the block group to the deleted_bgs list.
-			 */
-			list_move(&block_group->bg_list,
-				  &trans->transaction->deleted_bgs);
-			spin_unlock(&fs_info->unused_bgs_lock);
-			btrfs_get_block_group(block_group);
-		}
-end_trans:
-		btrfs_end_transaction(trans);
-next:
-		mutex_unlock(&fs_info->delete_unused_bgs_mutex);
-		btrfs_put_block_group(block_group);
-		spin_lock(&fs_info->unused_bgs_lock);
-	}
-	spin_unlock(&fs_info->unused_bgs_lock);
-}
-
-int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
-{
-	struct btrfs_super_block *disk_super;
-	u64 features;
-	u64 flags;
-	int mixed = 0;
-	int ret;
-
-	disk_super = fs_info->super_copy;
-	if (!btrfs_super_root(disk_super))
-		return -EINVAL;
-
-	features = btrfs_super_incompat_flags(disk_super);
-	if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
-		mixed = 1;
-
-	flags = BTRFS_BLOCK_GROUP_SYSTEM;
-	ret = create_space_info(fs_info, flags);
-	if (ret)
-		goto out;
-
-	if (mixed) {
-		flags = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA;
-		ret = create_space_info(fs_info, flags);
-	} else {
-		flags = BTRFS_BLOCK_GROUP_METADATA;
-		ret = create_space_info(fs_info, flags);
-		if (ret)
-			goto out;
-
-		flags = BTRFS_BLOCK_GROUP_DATA;
-		ret = create_space_info(fs_info, flags);
-	}
-out:
-	return ret;
-}
-
 int btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info,
 				   u64 start, u64 end)
 {
@@ -10784,10 +5535,9 @@
  * it while performing the free space search since we have already
  * held back allocations.
  */
-static int btrfs_trim_free_extents(struct btrfs_device *device,
-				   u64 minlen, u64 *trimmed)
+static int btrfs_trim_free_extents(struct btrfs_device *device, u64 *trimmed)
 {
-	u64 start = 0, len = 0;
+	u64 start = SZ_1M, len = 0, end = 0;
 	int ret;
 
 	*trimmed = 0;
@@ -10796,7 +5546,7 @@
 	if (!blk_queue_discard(bdev_get_queue(device->bdev)))
 		return 0;
 
-	/* Not writeable = nothing to do. */
+	/* Not writable = nothing to do. */
 	if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state))
 		return 0;
 
@@ -10808,43 +5558,41 @@
 
 	while (1) {
 		struct btrfs_fs_info *fs_info = device->fs_info;
-		struct btrfs_transaction *trans;
 		u64 bytes;
 
 		ret = mutex_lock_interruptible(&fs_info->chunk_mutex);
 		if (ret)
 			break;
 
-		ret = down_read_killable(&fs_info->commit_root_sem);
-		if (ret) {
+		find_first_clear_extent_bit(&device->alloc_state, start,
+					    &start, &end,
+					    CHUNK_TRIMMED | CHUNK_ALLOCATED);
+
+		/* Ensure we skip the reserved area in the first 1M */
+		start = max_t(u64, start, SZ_1M);
+
+		/*
+		 * If find_first_clear_extent_bit find a range that spans the
+		 * end of the device it will set end to -1, in this case it's up
+		 * to the caller to trim the value to the size of the device.
+		 */
+		end = min(end, device->total_bytes - 1);
+
+		len = end - start + 1;
+
+		/* We didn't find any extents */
+		if (!len) {
 			mutex_unlock(&fs_info->chunk_mutex);
+			ret = 0;
 			break;
 		}
 
-		spin_lock(&fs_info->trans_lock);
-		trans = fs_info->running_transaction;
-		if (trans)
-			refcount_inc(&trans->use_count);
-		spin_unlock(&fs_info->trans_lock);
-
-		if (!trans)
-			up_read(&fs_info->commit_root_sem);
-
-		ret = find_free_dev_extent_start(trans, device, minlen, start,
-						 &start, &len);
-		if (trans) {
-			up_read(&fs_info->commit_root_sem);
-			btrfs_put_transaction(trans);
-		}
-
-		if (ret) {
-			mutex_unlock(&fs_info->chunk_mutex);
-			if (ret == -ENOSPC)
-				ret = 0;
-			break;
-		}
-
-		ret = btrfs_issue_discard(device->bdev, start, len, &bytes);
+		ret = btrfs_issue_discard(device->bdev, start, len,
+					  &bytes);
+		if (!ret)
+			set_extent_bits(&device->alloc_state, start,
+					start + bytes - 1,
+					CHUNK_TRIMMED);
 		mutex_unlock(&fs_info->chunk_mutex);
 
 		if (ret)
@@ -10879,6 +5627,7 @@
 	struct btrfs_device *device;
 	struct list_head *devices;
 	u64 group_trimmed;
+	u64 range_end = U64_MAX;
 	u64 start;
 	u64 end;
 	u64 trimmed = 0;
@@ -10888,26 +5637,33 @@
 	int dev_ret = 0;
 	int ret = 0;
 
+	/*
+	 * Check range overflow if range->len is set.
+	 * The default range->len is U64_MAX.
+	 */
+	if (range->len != U64_MAX &&
+	    check_add_overflow(range->start, range->len, &range_end))
+		return -EINVAL;
+
 	cache = btrfs_lookup_first_block_group(fs_info, range->start);
-	for (; cache; cache = next_block_group(fs_info, cache)) {
-		if (cache->key.objectid >= (range->start + range->len)) {
+	for (; cache; cache = btrfs_next_block_group(cache)) {
+		if (cache->key.objectid >= range_end) {
 			btrfs_put_block_group(cache);
 			break;
 		}
 
 		start = max(range->start, cache->key.objectid);
-		end = min(range->start + range->len,
-				cache->key.objectid + cache->key.offset);
+		end = min(range_end, cache->key.objectid + cache->key.offset);
 
 		if (end - start >= range->minlen) {
-			if (!block_group_cache_done(cache)) {
-				ret = cache_block_group(cache, 0);
+			if (!btrfs_block_group_cache_done(cache)) {
+				ret = btrfs_cache_block_group(cache, 0);
 				if (ret) {
 					bg_failed++;
 					bg_ret = ret;
 					continue;
 				}
-				ret = wait_block_group_cache_done(cache);
+				ret = btrfs_wait_block_group_cache_done(cache);
 				if (ret) {
 					bg_failed++;
 					bg_ret = ret;
@@ -10936,8 +5692,7 @@
 	mutex_lock(&fs_info->fs_devices->device_list_mutex);
 	devices = &fs_info->fs_devices->devices;
 	list_for_each_entry(device, devices, dev_list) {
-		ret = btrfs_trim_free_extents(device, range->minlen,
-					      &group_trimmed);
+		ret = btrfs_trim_free_extents(device, &group_trimmed);
 		if (ret) {
 			dev_failed++;
 			dev_ret = ret;
@@ -11001,16 +5756,3 @@
 			       !atomic_read(&root->will_be_snapshotted));
 	}
 }
-
-void btrfs_mark_bg_unused(struct btrfs_block_group_cache *bg)
-{
-	struct btrfs_fs_info *fs_info = bg->fs_info;
-
-	spin_lock(&fs_info->unused_bgs_lock);
-	if (list_empty(&bg->bg_list)) {
-		btrfs_get_block_group(bg);
-		trace_btrfs_add_unused_block_group(bg);
-		list_add_tail(&bg->bg_list, &fs_info->unused_bgs);
-	}
-	spin_unlock(&fs_info->unused_bgs_lock);
-}
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 4dd6faa..cceaf05 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -89,9 +89,18 @@
 static inline void __btrfs_debug_check_extent_io_range(const char *caller,
 		struct extent_io_tree *tree, u64 start, u64 end)
 {
-	if (tree->ops && tree->ops->check_extent_io_range)
-		tree->ops->check_extent_io_range(tree->private_data, caller,
-						 start, end);
+	struct inode *inode = tree->private_data;
+	u64 isize;
+
+	if (!inode || !is_data_inode(inode))
+		return;
+
+	isize = i_size_read(inode);
+	if (end >= PAGE_SIZE && (end % 2) == 0 && end != isize - 1) {
+		btrfs_debug_rl(BTRFS_I(inode)->root->fs_info,
+		    "%s: ino %llu isize %llu odd range [%llu,%llu]",
+			caller, btrfs_ino(BTRFS_I(inode)), isize, start, end);
+	}
 }
 #else
 #define btrfs_leak_debug_add(new, head)	do {} while (0)
@@ -100,8 +109,6 @@
 #define btrfs_debug_check_extent_io_range(c, s, e)	do {} while (0)
 #endif
 
-#define BUFFER_LRU_MAX 64
-
 struct tree_entry {
 	u64 start;
 	u64 end;
@@ -138,7 +145,56 @@
 	return ret;
 }
 
-static void flush_write_bio(struct extent_page_data *epd);
+static int __must_check submit_one_bio(struct bio *bio, int mirror_num,
+				       unsigned long bio_flags)
+{
+	blk_status_t ret = 0;
+	struct extent_io_tree *tree = bio->bi_private;
+
+	bio->bi_private = NULL;
+
+	if (tree->ops)
+		ret = tree->ops->submit_bio_hook(tree->private_data, bio,
+						 mirror_num, bio_flags);
+	else
+		btrfsic_submit_bio(bio);
+
+	return blk_status_to_errno(ret);
+}
+
+/* Cleanup unsubmitted bios */
+static void end_write_bio(struct extent_page_data *epd, int ret)
+{
+	if (epd->bio) {
+		epd->bio->bi_status = errno_to_blk_status(ret);
+		bio_endio(epd->bio);
+		epd->bio = NULL;
+	}
+}
+
+/*
+ * Submit bio from extent page data via submit_one_bio
+ *
+ * Return 0 if everything is OK.
+ * Return <0 for error.
+ */
+static int __must_check flush_write_bio(struct extent_page_data *epd)
+{
+	int ret = 0;
+
+	if (epd->bio) {
+		ret = submit_one_bio(epd->bio, 0, 0);
+		/*
+		 * Clean up of epd->bio is handled by its endio function.
+		 * And endio is either triggered by successful bio execution
+		 * or the error handler of submit bio hook.
+		 * So at this point, no matter what happened, we don't need
+		 * to clean up epd->bio.
+		 */
+		epd->bio = NULL;
+	}
+	return ret;
+}
 
 int __init extent_io_init(void)
 {
@@ -191,14 +247,46 @@
 	bioset_exit(&btrfs_bioset);
 }
 
-void extent_io_tree_init(struct extent_io_tree *tree,
+void extent_io_tree_init(struct btrfs_fs_info *fs_info,
+			 struct extent_io_tree *tree, unsigned int owner,
 			 void *private_data)
 {
+	tree->fs_info = fs_info;
 	tree->state = RB_ROOT;
 	tree->ops = NULL;
 	tree->dirty_bytes = 0;
 	spin_lock_init(&tree->lock);
 	tree->private_data = private_data;
+	tree->owner = owner;
+}
+
+void extent_io_tree_release(struct extent_io_tree *tree)
+{
+	spin_lock(&tree->lock);
+	/*
+	 * Do a single barrier for the waitqueue_active check here, the state
+	 * of the waitqueue should not change once extent_io_tree_release is
+	 * called.
+	 */
+	smp_mb();
+	while (!RB_EMPTY_ROOT(&tree->state)) {
+		struct rb_node *node;
+		struct extent_state *state;
+
+		node = rb_first(&tree->state);
+		state = rb_entry(node, struct extent_state, rb_node);
+		rb_erase(&state->rb_node, &tree->state);
+		RB_CLEAR_NODE(&state->rb_node);
+		/*
+		 * btree io trees aren't supposed to have tasks waiting for
+		 * changes in the flags of extent states ever.
+		 */
+		ASSERT(!waitqueue_active(&state->wq));
+		free_extent_state(state);
+
+		cond_resched_lock(&tree->lock);
+	}
+	spin_unlock(&tree->lock);
 }
 
 static struct extent_state *alloc_extent_state(gfp_t mask)
@@ -271,9 +359,27 @@
 	return NULL;
 }
 
+/**
+ * __etree_search - searche @tree for an entry that contains @offset. Such
+ * entry would have entry->start <= offset && entry->end >= offset.
+ *
+ * @tree - the tree to search
+ * @offset - offset that should fall within an entry in @tree
+ * @next_ret - pointer to the first entry whose range ends after @offset
+ * @prev - pointer to the first entry whose range begins before @offset
+ * @p_ret - pointer where new node should be anchored (used when inserting an
+ *	    entry in the tree)
+ * @parent_ret - points to entry which would have been the parent of the entry,
+ *               containing @offset
+ *
+ * This function returns a pointer to the entry that contains @offset byte
+ * address. If no such entry exists, then NULL is returned and the other
+ * pointer arguments to the function are filled, otherwise the found entry is
+ * returned and other pointers are left untouched.
+ */
 static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset,
-				      struct rb_node **prev_ret,
 				      struct rb_node **next_ret,
+				      struct rb_node **prev_ret,
 				      struct rb_node ***p_ret,
 				      struct rb_node **parent_ret)
 {
@@ -302,23 +408,23 @@
 	if (parent_ret)
 		*parent_ret = prev;
 
-	if (prev_ret) {
+	if (next_ret) {
 		orig_prev = prev;
 		while (prev && offset > prev_entry->end) {
 			prev = rb_next(prev);
 			prev_entry = rb_entry(prev, struct tree_entry, rb_node);
 		}
-		*prev_ret = prev;
+		*next_ret = prev;
 		prev = orig_prev;
 	}
 
-	if (next_ret) {
+	if (prev_ret) {
 		prev_entry = rb_entry(prev, struct tree_entry, rb_node);
 		while (prev && offset < prev_entry->start) {
 			prev = rb_prev(prev);
 			prev_entry = rb_entry(prev, struct tree_entry, rb_node);
 		}
-		*next_ret = prev;
+		*prev_ret = prev;
 	}
 	return NULL;
 }
@@ -329,12 +435,12 @@
 		       struct rb_node ***p_ret,
 		       struct rb_node **parent_ret)
 {
-	struct rb_node *prev = NULL;
+	struct rb_node *next= NULL;
 	struct rb_node *ret;
 
-	ret = __etree_search(tree, offset, &prev, NULL, p_ret, parent_ret);
+	ret = __etree_search(tree, offset, &next, NULL, p_ret, parent_ret);
 	if (!ret)
-		return prev;
+		return next;
 	return ret;
 }
 
@@ -344,13 +450,6 @@
 	return tree_search_for_insert(tree, offset, NULL, NULL);
 }
 
-static void merge_cb(struct extent_io_tree *tree, struct extent_state *new,
-		     struct extent_state *other)
-{
-	if (tree->ops && tree->ops->merge_extent_hook)
-		tree->ops->merge_extent_hook(tree->private_data, new, other);
-}
-
 /*
  * utility function to look for merge candidates inside a given range.
  * Any extents with matching state are merged together into a single
@@ -366,7 +465,7 @@
 	struct extent_state *other;
 	struct rb_node *other_node;
 
-	if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY))
+	if (state->state & (EXTENT_LOCKED | EXTENT_BOUNDARY))
 		return;
 
 	other_node = rb_prev(&state->rb_node);
@@ -374,7 +473,10 @@
 		other = rb_entry(other_node, struct extent_state, rb_node);
 		if (other->end == state->start - 1 &&
 		    other->state == state->state) {
-			merge_cb(tree, state, other);
+			if (tree->private_data &&
+			    is_data_inode(tree->private_data))
+				btrfs_merge_delalloc_extent(tree->private_data,
+							    state, other);
 			state->start = other->start;
 			rb_erase(&other->rb_node, &tree->state);
 			RB_CLEAR_NODE(&other->rb_node);
@@ -386,7 +488,10 @@
 		other = rb_entry(other_node, struct extent_state, rb_node);
 		if (other->start == state->end + 1 &&
 		    other->state == state->state) {
-			merge_cb(tree, state, other);
+			if (tree->private_data &&
+			    is_data_inode(tree->private_data))
+				btrfs_merge_delalloc_extent(tree->private_data,
+							    state, other);
 			state->end = other->end;
 			rb_erase(&other->rb_node, &tree->state);
 			RB_CLEAR_NODE(&other->rb_node);
@@ -395,20 +500,6 @@
 	}
 }
 
-static void set_state_cb(struct extent_io_tree *tree,
-			 struct extent_state *state, unsigned *bits)
-{
-	if (tree->ops && tree->ops->set_bit_hook)
-		tree->ops->set_bit_hook(tree->private_data, state, bits);
-}
-
-static void clear_state_cb(struct extent_io_tree *tree,
-			   struct extent_state *state, unsigned *bits)
-{
-	if (tree->ops && tree->ops->clear_bit_hook)
-		tree->ops->clear_bit_hook(tree->private_data, state, bits);
-}
-
 static void set_state_bits(struct extent_io_tree *tree,
 			   struct extent_state *state, unsigned *bits,
 			   struct extent_changeset *changeset);
@@ -431,9 +522,11 @@
 {
 	struct rb_node *node;
 
-	if (end < start)
-		WARN(1, KERN_ERR "BTRFS: end < start %llu %llu\n",
-		       end, start);
+	if (end < start) {
+		btrfs_err(tree->fs_info,
+			"insert state: end < start %llu %llu", end, start);
+		WARN_ON(1);
+	}
 	state->start = start;
 	state->end = end;
 
@@ -443,7 +536,8 @@
 	if (node) {
 		struct extent_state *found;
 		found = rb_entry(node, struct extent_state, rb_node);
-		pr_err("BTRFS: found node %llu %llu on insert of %llu %llu\n",
+		btrfs_err(tree->fs_info,
+		       "found node %llu %llu on insert of %llu %llu",
 		       found->start, found->end, start, end);
 		return -EEXIST;
 	}
@@ -451,13 +545,6 @@
 	return 0;
 }
 
-static void split_cb(struct extent_io_tree *tree, struct extent_state *orig,
-		     u64 split)
-{
-	if (tree->ops && tree->ops->split_extent_hook)
-		tree->ops->split_extent_hook(tree->private_data, orig, split);
-}
-
 /*
  * split a given extent state struct in two, inserting the preallocated
  * struct 'prealloc' as the newly created second half.  'split' indicates an
@@ -477,7 +564,8 @@
 {
 	struct rb_node *node;
 
-	split_cb(tree, orig, split);
+	if (tree->private_data && is_data_inode(tree->private_data))
+		btrfs_split_delalloc_extent(tree->private_data, orig, split);
 
 	prealloc->start = orig->start;
 	prealloc->end = split - 1;
@@ -504,7 +592,7 @@
 
 /*
  * utility function to clear some bits in an extent state struct.
- * it will optionally wake up any one waiting on this state (wake == 1).
+ * it will optionally wake up anyone waiting on this state (wake == 1).
  *
  * If no bits are set on the state struct after clearing things, the
  * struct is freed and removed from the tree
@@ -523,7 +611,10 @@
 		WARN_ON(range > tree->dirty_bytes);
 		tree->dirty_bytes -= range;
 	}
-	clear_state_cb(tree, state, bits);
+
+	if (tree->private_data && is_data_inode(tree->private_data))
+		btrfs_clear_delalloc_extent(tree->private_data, state, bits);
+
 	ret = add_extent_changeset(state, bits_to_clear, changeset, 0);
 	BUG_ON(ret < 0);
 	state->state &= ~bits_to_clear;
@@ -588,15 +679,15 @@
 	int clear = 0;
 
 	btrfs_debug_check_extent_io_range(tree, start, end);
+	trace_btrfs_clear_extent_bit(tree, start, end - start + 1, bits);
 
 	if (bits & EXTENT_DELALLOC)
 		bits |= EXTENT_NORESERVE;
 
 	if (delete)
 		bits |= ~EXTENT_CTLBITS;
-	bits |= EXTENT_FIRST_DELALLOC;
 
-	if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY))
+	if (bits & (EXTENT_LOCKED | EXTENT_BOUNDARY))
 		clear = 1;
 again:
 	if (!prealloc && gfpflags_allow_blocking(mask)) {
@@ -800,7 +891,9 @@
 	unsigned bits_to_set = *bits & ~EXTENT_CTLBITS;
 	int ret;
 
-	set_state_cb(tree, state, bits);
+	if (tree->private_data && is_data_inode(tree->private_data))
+		btrfs_set_delalloc_extent(tree->private_data, state, bits);
+
 	if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
 		u64 range = state->end - state->start + 1;
 		tree->dirty_bytes += range;
@@ -826,7 +919,7 @@
 			struct extent_state **cached_ptr)
 {
 	return cache_state_if_flags(state, cached_ptr,
-				    EXTENT_IOBITS | EXTENT_BOUNDARY);
+				    EXTENT_LOCKED | EXTENT_BOUNDARY);
 }
 
 /*
@@ -856,8 +949,8 @@
 	u64 last_end;
 
 	btrfs_debug_check_extent_io_range(tree, start, end);
+	trace_btrfs_set_extent_bit(tree, start, end - start + 1, bits);
 
-	bits |= EXTENT_FIRST_DELALLOC;
 again:
 	if (!prealloc && gfpflags_allow_blocking(mask)) {
 		/*
@@ -1089,6 +1182,8 @@
 	bool first_iteration = true;
 
 	btrfs_debug_check_extent_io_range(tree, start, end);
+	trace_btrfs_convert_extent_bit(tree, start, end - start + 1, bits,
+				       clear_bits);
 
 again:
 	if (!prealloc) {
@@ -1288,6 +1383,13 @@
 				changeset);
 }
 
+int set_extent_bits_nowait(struct extent_io_tree *tree, u64 start, u64 end,
+			   unsigned bits)
+{
+	return __set_extent_bit(tree, start, end, bits, 0, NULL, NULL,
+				GFP_NOWAIT, NULL);
+}
+
 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 		     unsigned bits, int wake, int delete,
 		     struct extent_state **cached)
@@ -1424,20 +1526,15 @@
 			  struct extent_state **cached_state)
 {
 	struct extent_state *state;
-	struct rb_node *n;
 	int ret = 1;
 
 	spin_lock(&tree->lock);
 	if (cached_state && *cached_state) {
 		state = *cached_state;
 		if (state->end == start - 1 && extent_state_in_tree(state)) {
-			n = rb_next(&state->rb_node);
-			while (n) {
-				state = rb_entry(n, struct extent_state,
-						 rb_node);
+			while ((state = next_state(state)) != NULL) {
 				if (state->state & bits)
 					goto got_it;
-				n = rb_next(n);
 			}
 			free_extent_state(*cached_state);
 			*cached_state = NULL;
@@ -1460,20 +1557,133 @@
 	return ret;
 }
 
+/**
+ * find_first_clear_extent_bit - find the first range that has @bits not set.
+ * This range could start before @start.
+ *
+ * @tree - the tree to search
+ * @start - the offset at/after which the found extent should start
+ * @start_ret - records the beginning of the range
+ * @end_ret - records the end of the range (inclusive)
+ * @bits - the set of bits which must be unset
+ *
+ * Since unallocated range is also considered one which doesn't have the bits
+ * set it's possible that @end_ret contains -1, this happens in case the range
+ * spans (last_range_end, end of device]. In this case it's up to the caller to
+ * trim @end_ret to the appropriate size.
+ */
+void find_first_clear_extent_bit(struct extent_io_tree *tree, u64 start,
+				 u64 *start_ret, u64 *end_ret, unsigned bits)
+{
+	struct extent_state *state;
+	struct rb_node *node, *prev = NULL, *next;
+
+	spin_lock(&tree->lock);
+
+	/* Find first extent with bits cleared */
+	while (1) {
+		node = __etree_search(tree, start, &next, &prev, NULL, NULL);
+		if (!node) {
+			node = next;
+			if (!node) {
+				/*
+				 * We are past the last allocated chunk,
+				 * set start at the end of the last extent. The
+				 * device alloc tree should never be empty so
+				 * prev is always set.
+				 */
+				ASSERT(prev);
+				state = rb_entry(prev, struct extent_state, rb_node);
+				*start_ret = state->end + 1;
+				*end_ret = -1;
+				goto out;
+			}
+		}
+		/*
+		 * At this point 'node' either contains 'start' or start is
+		 * before 'node'
+		 */
+		state = rb_entry(node, struct extent_state, rb_node);
+
+		if (in_range(start, state->start, state->end - state->start + 1)) {
+			if (state->state & bits) {
+				/*
+				 * |--range with bits sets--|
+				 *    |
+				 *    start
+				 */
+				start = state->end + 1;
+			} else {
+				/*
+				 * 'start' falls within a range that doesn't
+				 * have the bits set, so take its start as
+				 * the beginning of the desired range
+				 *
+				 * |--range with bits cleared----|
+				 *      |
+				 *      start
+				 */
+				*start_ret = state->start;
+				break;
+			}
+		} else {
+			/*
+			 * |---prev range---|---hole/unset---|---node range---|
+			 *                          |
+			 *                        start
+			 *
+			 *                        or
+			 *
+			 * |---hole/unset--||--first node--|
+			 * 0   |
+			 *    start
+			 */
+			if (prev) {
+				state = rb_entry(prev, struct extent_state,
+						 rb_node);
+				*start_ret = state->end + 1;
+			} else {
+				*start_ret = 0;
+			}
+			break;
+		}
+	}
+
+	/*
+	 * Find the longest stretch from start until an entry which has the
+	 * bits set
+	 */
+	while (1) {
+		state = rb_entry(node, struct extent_state, rb_node);
+		if (state->end >= start && !(state->state & bits)) {
+			*end_ret = state->end;
+		} else {
+			*end_ret = state->start - 1;
+			break;
+		}
+
+		node = rb_next(node);
+		if (!node)
+			break;
+	}
+out:
+	spin_unlock(&tree->lock);
+}
+
 /*
  * find a contiguous range of bytes in the file marked as delalloc, not
  * more than 'max_bytes'.  start and end are used to return the range,
  *
- * 1 is returned if we find something, 0 if nothing was in the tree
+ * true is returned if we find something, false if nothing was in the tree
  */
-static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
+static noinline bool find_delalloc_range(struct extent_io_tree *tree,
 					u64 *start, u64 *end, u64 max_bytes,
 					struct extent_state **cached_state)
 {
 	struct rb_node *node;
 	struct extent_state *state;
 	u64 cur_start = *start;
-	u64 found = 0;
+	bool found = false;
 	u64 total_bytes = 0;
 
 	spin_lock(&tree->lock);
@@ -1484,8 +1694,7 @@
 	 */
 	node = tree_search(tree, cur_start);
 	if (!node) {
-		if (!found)
-			*end = (u64)-1;
+		*end = (u64)-1;
 		goto out;
 	}
 
@@ -1505,7 +1714,7 @@
 			*cached_state = state;
 			refcount_inc(&state->refs);
 		}
-		found++;
+		found = true;
 		*end = state->end;
 		cur_start = state->end + 1;
 		node = rb_next(node);
@@ -1563,19 +1772,22 @@
 }
 
 /*
- * find a contiguous range of bytes in the file marked as delalloc, not
- * more than 'max_bytes'.  start and end are used to return the range,
+ * Find and lock a contiguous range of bytes in the file marked as delalloc, no
+ * more than @max_bytes.  @Start and @end are used to return the range,
  *
- * 1 is returned if we find something, 0 if nothing was in the tree
+ * Return: true if we find something
+ *         false if nothing was in the tree
  */
-STATIC u64 find_lock_delalloc_range(struct inode *inode,
-				    struct extent_io_tree *tree,
+EXPORT_FOR_TESTS
+noinline_for_stack bool find_lock_delalloc_range(struct inode *inode,
 				    struct page *locked_page, u64 *start,
-				    u64 *end, u64 max_bytes)
+				    u64 *end)
 {
+	struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
+	u64 max_bytes = BTRFS_MAX_EXTENT_SIZE;
 	u64 delalloc_start;
 	u64 delalloc_end;
-	u64 found;
+	bool found;
 	struct extent_state *cached_state = NULL;
 	int ret;
 	int loops = 0;
@@ -1590,7 +1802,7 @@
 		*start = delalloc_start;
 		*end = delalloc_end;
 		free_extent_state(cached_state);
-		return 0;
+		return false;
 	}
 
 	/*
@@ -1610,6 +1822,7 @@
 	/* step two, lock all the pages after the page that has start */
 	ret = lock_delalloc_pages(inode, locked_page,
 				  delalloc_start, delalloc_end);
+	ASSERT(!ret || ret == -EAGAIN);
 	if (ret == -EAGAIN) {
 		/* some of the pages are gone, lets avoid looping by
 		 * shortening the size of the delalloc range we're searching
@@ -1621,11 +1834,10 @@
 			loops = 1;
 			goto again;
 		} else {
-			found = 0;
+			found = false;
 			goto out_failed;
 		}
 	}
-	BUG_ON(ret); /* Only valid values are 0 and -EAGAIN */
 
 	/* step three, lock the state bits for the whole range */
 	lock_extent_bits(tree, delalloc_start, delalloc_end, &cached_state);
@@ -1726,9 +1938,9 @@
 }
 
 void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
-				 u64 delalloc_end, struct page *locked_page,
-				 unsigned clear_bits,
-				 unsigned long page_ops)
+				  struct page *locked_page,
+				  unsigned clear_bits,
+				  unsigned long page_ops)
 {
 	clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, clear_bits, 1, 0,
 			 NULL);
@@ -2041,9 +2253,9 @@
 	return 0;
 }
 
-int repair_eb_io_failure(struct btrfs_fs_info *fs_info,
-			 struct extent_buffer *eb, int mirror_num)
+int btrfs_repair_eb_io_failure(struct extent_buffer *eb, int mirror_num)
 {
+	struct btrfs_fs_info *fs_info = eb->fs_info;
 	u64 start = eb->start;
 	int i, num_pages = num_extent_pages(eb);
 	int ret = 0;
@@ -2343,13 +2555,11 @@
 }
 
 /*
- * this is a generic handler for readpage errors (default
- * readpage_io_failed_hook). if other copies exist, read those and write back
- * good data to the failed position. does not investigate in remapping the
- * failed extent elsewhere, hoping the device will be smart enough to do this as
- * needed
+ * This is a generic handler for readpage errors. If other copies exist, read
+ * those and write back good data to the failed position. Does not investigate
+ * in remapping the failed extent elsewhere, hoping the device will be smart
+ * enough to do this as needed
  */
-
 static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
 			      struct page *page, u64 start, u64 end,
 			      int failed_mirror)
@@ -2362,7 +2572,7 @@
 	int read_mode = 0;
 	blk_status_t status;
 	int ret;
-	unsigned failed_bio_pages = bio_pages_all(failed_bio);
+	unsigned failed_bio_pages = failed_bio->bi_iter.bi_size >> PAGE_SHIFT;
 
 	BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
 
@@ -2391,7 +2601,7 @@
 		read_mode, failrec->this_mirror, failrec->in_validation);
 
 	status = tree->ops->submit_bio_hook(tree->private_data, bio, failrec->this_mirror,
-					 failrec->bio_flags, 0);
+					 failrec->bio_flags);
 	if (status) {
 		free_io_failure(failure_tree, tree, failrec);
 		bio_put(bio);
@@ -2406,14 +2616,9 @@
 void end_extent_writepage(struct page *page, int err, u64 start, u64 end)
 {
 	int uptodate = (err == 0);
-	struct extent_io_tree *tree;
 	int ret = 0;
 
-	tree = &BTRFS_I(page->mapping->host)->io_tree;
-
-	if (tree->ops && tree->ops->writepage_end_io_hook)
-		tree->ops->writepage_end_io_hook(page, start, end, NULL,
-				uptodate);
+	btrfs_writepage_endio_finish_ordered(page, start, end, uptodate);
 
 	if (!uptodate) {
 		ClearPageUptodate(page);
@@ -2438,10 +2643,10 @@
 	struct bio_vec *bvec;
 	u64 start;
 	u64 end;
-	int i;
+	struct bvec_iter_all iter_all;
 
 	ASSERT(!bio_flagged(bio, BIO_CLONED));
-	bio_for_each_segment_all(bvec, bio, i) {
+	bio_for_each_segment_all(bvec, bio, iter_all) {
 		struct page *page = bvec->bv_page;
 		struct inode *inode = page->mapping->host;
 		struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
@@ -2509,13 +2714,15 @@
 	u64 extent_len = 0;
 	int mirror;
 	int ret;
-	int i;
+	struct bvec_iter_all iter_all;
 
 	ASSERT(!bio_flagged(bio, BIO_CLONED));
-	bio_for_each_segment_all(bvec, bio, i) {
+	bio_for_each_segment_all(bvec, bio, iter_all) {
 		struct page *page = bvec->bv_page;
 		struct inode *inode = page->mapping->host;
 		struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+		bool data_inode = btrfs_ino(BTRFS_I(inode))
+			!= BTRFS_BTREE_INODE_OBJECTID;
 
 		btrfs_debug(fs_info,
 			"end_bio_extent_readpage: bi_sector=%llu, err=%d, mirror=%u",
@@ -2545,7 +2752,7 @@
 		len = bvec->bv_len;
 
 		mirror = io_bio->mirror_num;
-		if (likely(uptodate && tree->ops)) {
+		if (likely(uptodate)) {
 			ret = tree->ops->readpage_end_io_hook(io_bio, offset,
 							      page, start, end,
 							      mirror);
@@ -2561,38 +2768,35 @@
 		if (likely(uptodate))
 			goto readpage_ok;
 
-		if (tree->ops) {
-			ret = tree->ops->readpage_io_failed_hook(page, mirror);
-			if (ret == -EAGAIN) {
-				/*
-				 * Data inode's readpage_io_failed_hook() always
-				 * returns -EAGAIN.
-				 *
-				 * The generic bio_readpage_error handles errors
-				 * the following way: If possible, new read
-				 * requests are created and submitted and will
-				 * end up in end_bio_extent_readpage as well (if
-				 * we're lucky, not in the !uptodate case). In
-				 * that case it returns 0 and we just go on with
-				 * the next page in our bio. If it can't handle
-				 * the error it will return -EIO and we remain
-				 * responsible for that page.
-				 */
-				ret = bio_readpage_error(bio, offset, page,
-							 start, end, mirror);
-				if (ret == 0) {
-					uptodate = !bio->bi_status;
-					offset += len;
-					continue;
-				}
-			}
+		if (data_inode) {
 
 			/*
-			 * metadata's readpage_io_failed_hook() always returns
-			 * -EIO and fixes nothing.  -EIO is also returned if
-			 * data inode error could not be fixed.
+			 * The generic bio_readpage_error handles errors the
+			 * following way: If possible, new read requests are
+			 * created and submitted and will end up in
+			 * end_bio_extent_readpage as well (if we're lucky,
+			 * not in the !uptodate case). In that case it returns
+			 * 0 and we just go on with the next page in our bio.
+			 * If it can't handle the error it will return -EIO and
+			 * we remain responsible for that page.
 			 */
-			ASSERT(ret == -EIO);
+			ret = bio_readpage_error(bio, offset, page, start, end,
+						 mirror);
+			if (ret == 0) {
+				uptodate = !bio->bi_status;
+				offset += len;
+				continue;
+			}
+		} else {
+			struct extent_buffer *eb;
+
+			eb = (struct extent_buffer *)page->private;
+			set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
+			eb->read_mirror = mirror;
+			atomic_dec(&eb->io_pages);
+			if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD,
+					       &eb->bflags))
+				btree_readahead_hook(eb, -EIO);
 		}
 readpage_ok:
 		if (likely(uptodate)) {
@@ -2601,7 +2805,7 @@
 			unsigned off;
 
 			/* Zero out the end if this page straddles i_size */
-			off = i_size & (PAGE_SIZE-1);
+			off = offset_in_page(i_size);
 			if (page->index == end_index && off)
 				zero_user_segment(page, off, PAGE_SIZE);
 			SetPageUptodate(page);
@@ -2638,8 +2842,7 @@
 	if (extent_len)
 		endio_readpage_release_extent(tree, extent_start, extent_len,
 					      uptodate);
-	if (io_bio->end_io)
-		io_bio->end_io(io_bio, blk_status_to_errno(bio->bi_status));
+	btrfs_io_bio_free_csum(io_bio);
 	bio_put(bio);
 }
 
@@ -2658,12 +2861,11 @@
  * never fail.  We're returning a bio right now but you can call btrfs_io_bio
  * for the appropriate container_of magic
  */
-struct bio *btrfs_bio_alloc(struct block_device *bdev, u64 first_byte)
+struct bio *btrfs_bio_alloc(u64 first_byte)
 {
 	struct bio *bio;
 
 	bio = bio_alloc_bioset(GFP_NOFS, BIO_MAX_PAGES, &btrfs_bioset);
-	bio_set_dev(bio, bdev);
 	bio->bi_iter.bi_sector = first_byte >> 9;
 	btrfs_io_bio_init(btrfs_io_bio(bio));
 	return bio;
@@ -2709,28 +2911,6 @@
 	return bio;
 }
 
-static int __must_check submit_one_bio(struct bio *bio, int mirror_num,
-				       unsigned long bio_flags)
-{
-	blk_status_t ret = 0;
-	struct bio_vec *bvec = bio_last_bvec_all(bio);
-	struct page *page = bvec->bv_page;
-	struct extent_io_tree *tree = bio->bi_private;
-	u64 start;
-
-	start = page_offset(page) + bvec->bv_offset;
-
-	bio->bi_private = NULL;
-
-	if (tree->ops)
-		ret = tree->ops->submit_bio_hook(tree->private_data, bio,
-					   mirror_num, bio_flags, start);
-	else
-		btrfsic_submit_bio(bio);
-
-	return blk_status_to_errno(ret);
-}
-
 /*
  * @opf:	bio REQ_OP_* and REQ_* flags as one value
  * @tree:	tree so we can call our merge_bio hook
@@ -2776,8 +2956,8 @@
 		else
 			contig = bio_end_sector(bio) == sector;
 
-		if (tree->ops && btrfs_merge_bio_hook(page, offset, page_size,
-						      bio, bio_flags))
+		ASSERT(tree->ops);
+		if (btrfs_bio_fits_in_stripe(page, page_size, bio, bio_flags))
 			can_merge = false;
 
 		if (prev_bio_flags != bio_flags || !contig || !can_merge ||
@@ -2791,12 +2971,13 @@
 			bio = NULL;
 		} else {
 			if (wbc)
-				wbc_account_io(wbc, page, page_size);
+				wbc_account_cgroup_owner(wbc, page, page_size);
 			return 0;
 		}
 	}
 
-	bio = btrfs_bio_alloc(bdev, offset);
+	bio = btrfs_bio_alloc(offset);
+	bio_set_dev(bio, bdev);
 	bio_add_page(bio, page, page_size, pg_offset);
 	bio->bi_end_io = end_io_func;
 	bio->bi_private = tree;
@@ -2804,7 +2985,7 @@
 	bio->bi_opf = opf;
 	if (wbc) {
 		wbc_init_bio(wbc, bio);
-		wbc_account_io(wbc, page, page_size);
+		wbc_account_cgroup_owner(wbc, page, page_size);
 	}
 
 	*bio_ret = bio;
@@ -2905,7 +3086,7 @@
 
 	if (page->index == last_byte >> PAGE_SHIFT) {
 		char *userpage;
-		size_t zero_offset = last_byte & (PAGE_SIZE - 1);
+		size_t zero_offset = offset_in_page(last_byte);
 
 		if (zero_offset) {
 			iosize = PAGE_SIZE - zero_offset;
@@ -3002,11 +3183,11 @@
 		 */
 		if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) &&
 		    prev_em_start && *prev_em_start != (u64)-1 &&
-		    *prev_em_start != em->orig_start)
+		    *prev_em_start != em->start)
 			force_bio_submit = true;
 
 		if (prev_em_start)
-			*prev_em_start = em->orig_start;
+			*prev_em_start = em->start;
 
 		free_extent_map(em);
 		em = NULL;
@@ -3076,7 +3257,7 @@
 	return ret;
 }
 
-static inline void __do_contiguous_readpages(struct extent_io_tree *tree,
+static inline void contiguous_readpages(struct extent_io_tree *tree,
 					     struct page *pages[], int nr_pages,
 					     u64 start, u64 end,
 					     struct extent_map **em_cached,
@@ -3084,21 +3265,10 @@
 					     unsigned long *bio_flags,
 					     u64 *prev_em_start)
 {
-	struct inode *inode;
-	struct btrfs_ordered_extent *ordered;
+	struct btrfs_inode *inode = BTRFS_I(pages[0]->mapping->host);
 	int index;
 
-	inode = pages[0]->mapping->host;
-	while (1) {
-		lock_extent(tree, start, end);
-		ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start,
-						     end - start + 1);
-		if (!ordered)
-			break;
-		unlock_extent(tree, start, end);
-		btrfs_start_ordered_extent(inode, ordered, 1);
-		btrfs_put_ordered_extent(ordered);
-	}
+	btrfs_lock_and_flush_ordered_range(tree, inode, start, end, NULL);
 
 	for (index = 0; index < nr_pages; index++) {
 		__do_readpage(tree, pages[index], btrfs_get_extent, em_cached,
@@ -3107,46 +3277,6 @@
 	}
 }
 
-static void __extent_readpages(struct extent_io_tree *tree,
-			       struct page *pages[],
-			       int nr_pages,
-			       struct extent_map **em_cached,
-			       struct bio **bio, unsigned long *bio_flags,
-			       u64 *prev_em_start)
-{
-	u64 start = 0;
-	u64 end = 0;
-	u64 page_start;
-	int index;
-	int first_index = 0;
-
-	for (index = 0; index < nr_pages; index++) {
-		page_start = page_offset(pages[index]);
-		if (!end) {
-			start = page_start;
-			end = start + PAGE_SIZE - 1;
-			first_index = index;
-		} else if (end + 1 == page_start) {
-			end += PAGE_SIZE;
-		} else {
-			__do_contiguous_readpages(tree, &pages[first_index],
-						  index - first_index, start,
-						  end, em_cached,
-						  bio, bio_flags,
-						  prev_em_start);
-			start = page_start;
-			end = start + PAGE_SIZE - 1;
-			first_index = index;
-		}
-	}
-
-	if (end)
-		__do_contiguous_readpages(tree, &pages[first_index],
-					  index - first_index, start,
-					  end, em_cached, bio,
-					  bio_flags, prev_em_start);
-}
-
 static int __extent_read_full_page(struct extent_io_tree *tree,
 				   struct page *page,
 				   get_extent_t *get_extent,
@@ -3154,22 +3284,12 @@
 				   unsigned long *bio_flags,
 				   unsigned int read_flags)
 {
-	struct inode *inode = page->mapping->host;
-	struct btrfs_ordered_extent *ordered;
+	struct btrfs_inode *inode = BTRFS_I(page->mapping->host);
 	u64 start = page_offset(page);
 	u64 end = start + PAGE_SIZE - 1;
 	int ret;
 
-	while (1) {
-		lock_extent(tree, start, end);
-		ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start,
-						PAGE_SIZE);
-		if (!ordered)
-			break;
-		unlock_extent(tree, start, end);
-		btrfs_start_ordered_extent(inode, ordered, 1);
-		btrfs_put_ordered_extent(ordered);
-	}
+	btrfs_lock_and_flush_ordered_range(tree, inode, start, end, NULL);
 
 	ret = __do_readpage(tree, page, get_extent, NULL, bio, mirror_num,
 			    bio_flags, read_flags, NULL);
@@ -3199,7 +3319,7 @@
 /*
  * helper for __extent_writepage, doing all of the delayed allocation setup.
  *
- * This returns 1 if our fill_delalloc function did all the work required
+ * This returns 1 if btrfs_run_delalloc_range function did all the work required
  * to write the page (copy into inline extent).  In this case the IO has
  * been started and the page is already unlocked.
  *
@@ -3207,44 +3327,34 @@
  * This returns < 0 if there were errors (page still locked)
  */
 static noinline_for_stack int writepage_delalloc(struct inode *inode,
-			      struct page *page, struct writeback_control *wbc,
-			      struct extent_page_data *epd,
-			      u64 delalloc_start,
-			      unsigned long *nr_written)
+		struct page *page, struct writeback_control *wbc,
+		u64 delalloc_start, unsigned long *nr_written)
 {
-	struct extent_io_tree *tree = epd->tree;
 	u64 page_end = delalloc_start + PAGE_SIZE - 1;
-	u64 nr_delalloc;
+	bool found;
 	u64 delalloc_to_write = 0;
 	u64 delalloc_end = 0;
 	int ret;
 	int page_started = 0;
 
-	if (epd->extent_locked || !tree->ops || !tree->ops->fill_delalloc)
-		return 0;
 
 	while (delalloc_end < page_end) {
-		nr_delalloc = find_lock_delalloc_range(inode, tree,
-					       page,
+		found = find_lock_delalloc_range(inode, page,
 					       &delalloc_start,
-					       &delalloc_end,
-					       BTRFS_MAX_EXTENT_SIZE);
-		if (nr_delalloc == 0) {
+					       &delalloc_end);
+		if (!found) {
 			delalloc_start = delalloc_end + 1;
 			continue;
 		}
-		ret = tree->ops->fill_delalloc(inode, page,
-					       delalloc_start,
-					       delalloc_end,
-					       &page_started,
-					       nr_written, wbc);
-		/* File system has been set read-only */
+		ret = btrfs_run_delalloc_range(inode, page, delalloc_start,
+				delalloc_end, &page_started, nr_written, wbc);
 		if (ret) {
 			SetPageError(page);
-			/* fill_delalloc should be return < 0 for error
-			 * but just in case, we use > 0 here meaning the
-			 * IO is started, so we don't want to return > 0
-			 * unless things are going well.
+			/*
+			 * btrfs_run_delalloc_range should return < 0 for error
+			 * but just in case, we use > 0 here meaning the IO is
+			 * started, so we don't want to return > 0 unless
+			 * things are going well.
 			 */
 			ret = ret < 0 ? ret : -EIO;
 			goto done;
@@ -3317,20 +3427,17 @@
 	int nr = 0;
 	bool compressed;
 
-	if (tree->ops && tree->ops->writepage_start_hook) {
-		ret = tree->ops->writepage_start_hook(page, start,
-						      page_end);
-		if (ret) {
-			/* Fixup worker will requeue */
-			if (ret == -EBUSY)
-				wbc->pages_skipped++;
-			else
-				redirty_page_for_writepage(wbc, page);
+	ret = btrfs_writepage_cow_fixup(page, start, page_end);
+	if (ret) {
+		/* Fixup worker will requeue */
+		if (ret == -EBUSY)
+			wbc->pages_skipped++;
+		else
+			redirty_page_for_writepage(wbc, page);
 
-			update_nr_written(wbc, nr_written);
-			unlock_page(page);
-			return 1;
-		}
+		update_nr_written(wbc, nr_written);
+		unlock_page(page);
+		return 1;
 	}
 
 	/*
@@ -3341,9 +3448,7 @@
 
 	end = page_end;
 	if (i_size <= start) {
-		if (tree->ops && tree->ops->writepage_end_io_hook)
-			tree->ops->writepage_end_io_hook(page, start,
-							 page_end, NULL, 1);
+		btrfs_writepage_endio_finish_ordered(page, start, page_end, 1);
 		goto done;
 	}
 
@@ -3354,9 +3459,8 @@
 		u64 offset;
 
 		if (cur >= i_size) {
-			if (tree->ops && tree->ops->writepage_end_io_hook)
-				tree->ops->writepage_end_io_hook(page, cur,
-							 page_end, NULL, 1);
+			btrfs_writepage_endio_finish_ordered(page, cur,
+							     page_end, 1);
 			break;
 		}
 		em = btrfs_get_extent(BTRFS_I(inode), page, pg_offset, cur,
@@ -3390,11 +3494,10 @@
 			 * end_io notification does not happen here for
 			 * compressed extents
 			 */
-			if (!compressed && tree->ops &&
-			    tree->ops->writepage_end_io_hook)
-				tree->ops->writepage_end_io_hook(page, cur,
-							 cur + iosize - 1,
-							 NULL, 1);
+			if (!compressed)
+				btrfs_writepage_endio_finish_ordered(page, cur,
+							    cur + iosize - 1,
+							    1);
 			else if (compressed) {
 				/* we don't want to end_page_writeback on
 				 * a compressed extent.  this happens
@@ -3440,6 +3543,9 @@
  * records are inserted to lock ranges in the tree, and as dirty areas
  * are found, they are marked writeback.  Then the lock bits are removed
  * and the end_io handler clears the writeback ranges
+ *
+ * Return 0 if everything goes well.
+ * Return <0 for error.
  */
 static int __extent_writepage(struct page *page, struct writeback_control *wbc,
 			      struct extent_page_data *epd)
@@ -3463,7 +3569,7 @@
 
 	ClearPageError(page);
 
-	pg_offset = i_size & (PAGE_SIZE - 1);
+	pg_offset = offset_in_page(i_size);
 	if (page->index > end_index ||
 	   (page->index == end_index && !pg_offset)) {
 		page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
@@ -3485,11 +3591,13 @@
 
 	set_page_extent_mapped(page);
 
-	ret = writepage_delalloc(inode, page, wbc, epd, start, &nr_written);
-	if (ret == 1)
-		goto done_unlocked;
-	if (ret)
-		goto done;
+	if (!epd->extent_locked) {
+		ret = writepage_delalloc(inode, page, wbc, start, &nr_written);
+		if (ret == 1)
+			goto done_unlocked;
+		if (ret)
+			goto done;
+	}
 
 	ret = __extent_writepage_io(inode, page, wbc, epd,
 				    i_size, nr_written, write_flags, &nr);
@@ -3507,6 +3615,7 @@
 		end_extent_writepage(page, ret, start, page_end);
 	}
 	unlock_page(page);
+	ASSERT(ret <= 0);
 	return ret;
 
 done_unlocked:
@@ -3519,18 +3628,33 @@
 		       TASK_UNINTERRUPTIBLE);
 }
 
-static noinline_for_stack int
-lock_extent_buffer_for_io(struct extent_buffer *eb,
-			  struct btrfs_fs_info *fs_info,
+static void end_extent_buffer_writeback(struct extent_buffer *eb)
+{
+	clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
+	smp_mb__after_atomic();
+	wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK);
+}
+
+/*
+ * Lock eb pages and flush the bio if we can't the locks
+ *
+ * Return  0 if nothing went wrong
+ * Return >0 is same as 0, except bio is not submitted
+ * Return <0 if something went wrong, no page is locked
+ */
+static noinline_for_stack int lock_extent_buffer_for_io(struct extent_buffer *eb,
 			  struct extent_page_data *epd)
 {
-	int i, num_pages;
+	struct btrfs_fs_info *fs_info = eb->fs_info;
+	int i, num_pages, failed_page_nr;
 	int flush = 0;
 	int ret = 0;
 
 	if (!btrfs_try_tree_write_lock(eb)) {
+		ret = flush_write_bio(epd);
+		if (ret < 0)
+			return ret;
 		flush = 1;
-		flush_write_bio(epd);
 		btrfs_tree_lock(eb);
 	}
 
@@ -3539,7 +3663,9 @@
 		if (!epd->sync_io)
 			return 0;
 		if (!flush) {
-			flush_write_bio(epd);
+			ret = flush_write_bio(epd);
+			if (ret < 0)
+				return ret;
 			flush = 1;
 		}
 		while (1) {
@@ -3580,7 +3706,14 @@
 
 		if (!trylock_page(p)) {
 			if (!flush) {
-				flush_write_bio(epd);
+				int err;
+
+				err = flush_write_bio(epd);
+				if (err < 0) {
+					ret = err;
+					failed_page_nr = i;
+					goto err_unlock;
+				}
 				flush = 1;
 			}
 			lock_page(p);
@@ -3588,24 +3721,45 @@
 	}
 
 	return ret;
-}
-
-static void end_extent_buffer_writeback(struct extent_buffer *eb)
-{
-	clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
-	smp_mb__after_atomic();
-	wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK);
+err_unlock:
+	/* Unlock already locked pages */
+	for (i = 0; i < failed_page_nr; i++)
+		unlock_page(eb->pages[i]);
+	/*
+	 * Clear EXTENT_BUFFER_WRITEBACK and wake up anyone waiting on it.
+	 * Also set back EXTENT_BUFFER_DIRTY so future attempts to this eb can
+	 * be made and undo everything done before.
+	 */
+	btrfs_tree_lock(eb);
+	spin_lock(&eb->refs_lock);
+	set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
+	end_extent_buffer_writeback(eb);
+	spin_unlock(&eb->refs_lock);
+	percpu_counter_add_batch(&fs_info->dirty_metadata_bytes, eb->len,
+				 fs_info->dirty_metadata_batch);
+	btrfs_clear_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
+	btrfs_tree_unlock(eb);
+	return ret;
 }
 
 static void set_btree_ioerr(struct page *page)
 {
 	struct extent_buffer *eb = (struct extent_buffer *)page->private;
+	struct btrfs_fs_info *fs_info;
 
 	SetPageError(page);
 	if (test_and_set_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags))
 		return;
 
 	/*
+	 * If we error out, we should add back the dirty_metadata_bytes
+	 * to make it consistent.
+	 */
+	fs_info = eb->fs_info;
+	percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
+				 eb->len, fs_info->dirty_metadata_batch);
+
+	/*
 	 * If writeback for a btree extent that doesn't belong to a log tree
 	 * failed, increment the counter transaction->eb_write_errors.
 	 * We do this because while the transaction is running and before it's
@@ -3662,10 +3816,11 @@
 {
 	struct bio_vec *bvec;
 	struct extent_buffer *eb;
-	int i, done;
+	int done;
+	struct bvec_iter_all iter_all;
 
 	ASSERT(!bio_flagged(bio, BIO_CLONED));
-	bio_for_each_segment_all(bvec, bio, i) {
+	bio_for_each_segment_all(bvec, bio, iter_all) {
 		struct page *page = bvec->bv_page;
 
 		eb = (struct extent_buffer *)page->private;
@@ -3690,10 +3845,10 @@
 }
 
 static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
-			struct btrfs_fs_info *fs_info,
 			struct writeback_control *wbc,
 			struct extent_page_data *epd)
 {
+	struct btrfs_fs_info *fs_info = eb->fs_info;
 	struct block_device *bdev = fs_info->fs_devices->latest_bdev;
 	struct extent_io_tree *tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
 	u64 offset = eb->start;
@@ -3719,7 +3874,7 @@
 		 * header 0 1 2 .. N ... data_N .. data_2 data_1 data_0
 		 */
 		start = btrfs_item_nr_offset(nritems);
-		end = BTRFS_LEAF_DATA_OFFSET + leaf_data_end(fs_info, eb);
+		end = BTRFS_LEAF_DATA_OFFSET + leaf_data_end(eb);
 		memzero_extent_buffer(eb, start, end - start);
 	}
 
@@ -3762,7 +3917,6 @@
 				   struct writeback_control *wbc)
 {
 	struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree;
-	struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info;
 	struct extent_buffer *eb, *prev_eb = NULL;
 	struct extent_page_data epd = {
 		.bio = NULL,
@@ -3778,7 +3932,7 @@
 	pgoff_t index;
 	pgoff_t end;		/* Inclusive */
 	int scanned = 0;
-	int tag;
+	xa_mark_t tag;
 
 	pagevec_init(&pvec);
 	if (wbc->range_cyclic) {
@@ -3837,13 +3991,17 @@
 				continue;
 
 			prev_eb = eb;
-			ret = lock_extent_buffer_for_io(eb, fs_info, &epd);
+			ret = lock_extent_buffer_for_io(eb, &epd);
 			if (!ret) {
 				free_extent_buffer(eb);
 				continue;
+			} else if (ret < 0) {
+				done = 1;
+				free_extent_buffer(eb);
+				break;
 			}
 
-			ret = write_one_eb(eb, fs_info, wbc, &epd);
+			ret = write_one_eb(eb, wbc, &epd);
 			if (ret) {
 				done = 1;
 				free_extent_buffer(eb);
@@ -3870,7 +4028,12 @@
 		index = 0;
 		goto retry;
 	}
-	flush_write_bio(&epd);
+	ASSERT(ret <= 0);
+	if (ret < 0) {
+		end_write_bio(&epd, ret);
+		return ret;
+	}
+	ret = flush_write_bio(&epd);
 	return ret;
 }
 
@@ -3903,7 +4066,7 @@
 	pgoff_t done_index;
 	int range_whole = 0;
 	int scanned = 0;
-	int tag;
+	xa_mark_t tag;
 
 	/*
 	 * We have to hold onto the inode so that ordered extents can do their
@@ -3928,12 +4091,25 @@
 			range_whole = 1;
 		scanned = 1;
 	}
-	if (wbc->sync_mode == WB_SYNC_ALL)
+
+	/*
+	 * We do the tagged writepage as long as the snapshot flush bit is set
+	 * and we are the first one who do the filemap_flush() on this inode.
+	 *
+	 * The nr_to_write == LONG_MAX is needed to make sure other flushers do
+	 * not race in and drop the bit.
+	 */
+	if (range_whole && wbc->nr_to_write == LONG_MAX &&
+	    test_and_clear_bit(BTRFS_INODE_SNAPSHOT_FLUSH,
+			       &BTRFS_I(inode)->runtime_flags))
+		wbc->tagged_writepages = 1;
+
+	if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
 		tag = PAGECACHE_TAG_TOWRITE;
 	else
 		tag = PAGECACHE_TAG_DIRTY;
 retry:
-	if (wbc->sync_mode == WB_SYNC_ALL)
+	if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
 		tag_pages_for_writeback(mapping, index, end);
 	done_index = index;
 	while (!done && !nr_to_write_done && (index <= end) &&
@@ -3954,7 +4130,8 @@
 			 * tmpfs file mapping
 			 */
 			if (!trylock_page(page)) {
-				flush_write_bio(epd);
+				ret = flush_write_bio(epd);
+				BUG_ON(ret < 0);
 				lock_page(page);
 			}
 
@@ -3964,8 +4141,10 @@
 			}
 
 			if (wbc->sync_mode != WB_SYNC_NONE) {
-				if (PageWriteback(page))
-					flush_write_bio(epd);
+				if (PageWriteback(page)) {
+					ret = flush_write_bio(epd);
+					BUG_ON(ret < 0);
+				}
 				wait_on_page_writeback(page);
 			}
 
@@ -3976,11 +4155,6 @@
 			}
 
 			ret = __extent_writepage(page, wbc, epd);
-
-			if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
-				unlock_page(page);
-				ret = 0;
-			}
 			if (ret < 0) {
 				/*
 				 * done_index is set past this page,
@@ -4023,17 +4197,6 @@
 	return ret;
 }
 
-static void flush_write_bio(struct extent_page_data *epd)
-{
-	if (epd->bio) {
-		int ret;
-
-		ret = submit_one_bio(epd->bio, 0, 0);
-		BUG_ON(ret < 0); /* -ENOMEM */
-		epd->bio = NULL;
-	}
-}
-
 int extent_write_full_page(struct page *page, struct writeback_control *wbc)
 {
 	int ret;
@@ -4045,8 +4208,14 @@
 	};
 
 	ret = __extent_writepage(page, wbc, &epd);
+	ASSERT(ret <= 0);
+	if (ret < 0) {
+		end_write_bio(&epd, ret);
+		return ret;
+	}
 
-	flush_write_bio(&epd);
+	ret = flush_write_bio(&epd);
+	ASSERT(ret <= 0);
 	return ret;
 }
 
@@ -4078,17 +4247,20 @@
 		if (clear_page_dirty_for_io(page))
 			ret = __extent_writepage(page, &wbc_writepages, &epd);
 		else {
-			if (tree->ops && tree->ops->writepage_end_io_hook)
-				tree->ops->writepage_end_io_hook(page, start,
-						 start + PAGE_SIZE - 1,
-						 NULL, 1);
+			btrfs_writepage_endio_finish_ordered(page, start,
+						    start + PAGE_SIZE - 1, 1);
 			unlock_page(page);
 		}
 		put_page(page);
 		start += PAGE_SIZE;
 	}
 
-	flush_write_bio(&epd);
+	ASSERT(ret <= 0);
+	if (ret < 0) {
+		end_write_bio(&epd, ret);
+		return ret;
+	}
+	ret = flush_write_bio(&epd);
 	return ret;
 }
 
@@ -4104,7 +4276,12 @@
 	};
 
 	ret = extent_write_cache_pages(mapping, wbc, &epd);
-	flush_write_bio(&epd);
+	ASSERT(ret <= 0);
+	if (ret < 0) {
+		end_write_bio(&epd, ret);
+		return ret;
+	}
+	ret = flush_write_bio(&epd);
 	return ret;
 }
 
@@ -4112,42 +4289,45 @@
 		     unsigned nr_pages)
 {
 	struct bio *bio = NULL;
-	unsigned page_idx;
 	unsigned long bio_flags = 0;
 	struct page *pagepool[16];
-	struct page *page;
 	struct extent_map *em_cached = NULL;
 	struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree;
 	int nr = 0;
 	u64 prev_em_start = (u64)-1;
 
-	for (page_idx = 0; page_idx < nr_pages; page_idx++) {
-		page = list_entry(pages->prev, struct page, lru);
+	while (!list_empty(pages)) {
+		u64 contig_end = 0;
 
-		prefetchw(&page->flags);
-		list_del(&page->lru);
-		if (add_to_page_cache_lru(page, mapping,
-					page->index,
-					readahead_gfp_mask(mapping))) {
-			put_page(page);
-			continue;
+		for (nr = 0; nr < ARRAY_SIZE(pagepool) && !list_empty(pages);) {
+			struct page *page = lru_to_page(pages);
+
+			prefetchw(&page->flags);
+			list_del(&page->lru);
+			if (add_to_page_cache_lru(page, mapping, page->index,
+						readahead_gfp_mask(mapping))) {
+				put_page(page);
+				break;
+			}
+
+			pagepool[nr++] = page;
+			contig_end = page_offset(page) + PAGE_SIZE - 1;
 		}
 
-		pagepool[nr++] = page;
-		if (nr < ARRAY_SIZE(pagepool))
-			continue;
-		__extent_readpages(tree, pagepool, nr, &em_cached, &bio,
-				&bio_flags, &prev_em_start);
-		nr = 0;
+		if (nr) {
+			u64 contig_start = page_offset(pagepool[0]);
+
+			ASSERT(contig_start + nr * PAGE_SIZE - 1 == contig_end);
+
+			contiguous_readpages(tree, pagepool, nr, contig_start,
+				     contig_end, &em_cached, &bio, &bio_flags,
+				     &prev_em_start);
+		}
 	}
-	if (nr)
-		__extent_readpages(tree, pagepool, nr, &em_cached, &bio,
-				&bio_flags, &prev_em_start);
 
 	if (em_cached)
 		free_extent_map(em_cached);
 
-	BUG_ON(!list_empty(pages));
 	if (bio)
 		return submit_one_bio(bio, 0, bio_flags);
 	return 0;
@@ -4172,10 +4352,8 @@
 
 	lock_extent_bits(tree, start, end, &cached_state);
 	wait_on_page_writeback(page);
-	clear_extent_bit(tree, start, end,
-			 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
-			 EXTENT_DO_ACCOUNTING,
-			 1, 1, &cached_state);
+	clear_extent_bit(tree, start, end, EXTENT_LOCKED | EXTENT_DELALLOC |
+			 EXTENT_DO_ACCOUNTING, 1, 1, &cached_state);
 	return 0;
 }
 
@@ -4191,10 +4369,9 @@
 	u64 end = start + PAGE_SIZE - 1;
 	int ret = 1;
 
-	if (test_range_bit(tree, start, end,
-			   EXTENT_IOBITS, 0, NULL))
+	if (test_range_bit(tree, start, end, EXTENT_LOCKED, 0, NULL)) {
 		ret = 0;
-	else {
+	} else {
 		/*
 		 * at this point we can safely clear everything except the
 		 * locked bit and the nodatasum bit
@@ -4247,8 +4424,7 @@
 			}
 			if (!test_range_bit(tree, em->start,
 					    extent_map_end(em) - 1,
-					    EXTENT_LOCKED | EXTENT_WRITEBACK,
-					    0, NULL)) {
+					    EXTENT_LOCKED, 0, NULL)) {
 				set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
 					&btrfs_inode->runtime_flags);
 				remove_extent_mapping(map, em);
@@ -4284,8 +4460,7 @@
 		if (len == 0)
 			break;
 		len = ALIGN(len, sectorsize);
-		em = btrfs_get_extent_fiemap(BTRFS_I(inode), NULL, 0, offset,
-				len, 0);
+		em = btrfs_get_extent_fiemap(BTRFS_I(inode), offset, len);
 		if (IS_ERR_OR_NULL(em))
 			return em;
 
@@ -4336,7 +4511,7 @@
 
 	/*
 	 * Sanity check, extent_fiemap() should have ensured that new
-	 * fiemap extent won't overlap with cahced one.
+	 * fiemap extent won't overlap with cached one.
 	 * Not recoverable.
 	 *
 	 * NOTE: Physical address can overlap, due to compression
@@ -4398,8 +4573,7 @@
  * In this case, the first extent range will be cached but not emitted.
  * So we must emit it before ending extent_fiemap().
  */
-static int emit_last_fiemap_cache(struct btrfs_fs_info *fs_info,
-				  struct fiemap_extent_info *fieinfo,
+static int emit_last_fiemap_cache(struct fiemap_extent_info *fieinfo,
 				  struct fiemap_cache *cache)
 {
 	int ret;
@@ -4433,6 +4607,8 @@
 	struct btrfs_path *path;
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct fiemap_cache cache = { 0 };
+	struct ulist *roots;
+	struct ulist *tmp_ulist;
 	int end = 0;
 	u64 em_start = 0;
 	u64 em_len = 0;
@@ -4446,6 +4622,13 @@
 		return -ENOMEM;
 	path->leave_spinning = 1;
 
+	roots = ulist_alloc(GFP_KERNEL);
+	tmp_ulist = ulist_alloc(GFP_KERNEL);
+	if (!roots || !tmp_ulist) {
+		ret = -ENOMEM;
+		goto out_free_ulist;
+	}
+
 	start = round_down(start, btrfs_inode_sectorsize(inode));
 	len = round_up(max, btrfs_inode_sectorsize(inode)) - start;
 
@@ -4456,8 +4639,7 @@
 	ret = btrfs_lookup_file_extent(NULL, root, path,
 			btrfs_ino(BTRFS_I(inode)), -1, 0);
 	if (ret < 0) {
-		btrfs_free_path(path);
-		return ret;
+		goto out_free_ulist;
 	} else {
 		WARN_ON(!ret);
 		if (ret == 1)
@@ -4566,7 +4748,7 @@
 			 */
 			ret = btrfs_check_shared(root,
 						 btrfs_ino(BTRFS_I(inode)),
-						 bytenr);
+						 bytenr, roots, tmp_ulist);
 			if (ret < 0)
 				goto out_free;
 			if (ret)
@@ -4606,12 +4788,16 @@
 	}
 out_free:
 	if (!ret)
-		ret = emit_last_fiemap_cache(root->fs_info, fieinfo, &cache);
+		ret = emit_last_fiemap_cache(fieinfo, &cache);
 	free_extent_map(em);
 out:
-	btrfs_free_path(path);
 	unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len - 1,
 			     &cached_state);
+
+out_free_ulist:
+	btrfs_free_path(path);
+	ulist_free(roots);
+	ulist_free(tmp_ulist);
 	return ret;
 }
 
@@ -4698,13 +4884,9 @@
 	eb->fs_info = fs_info;
 	eb->bflags = 0;
 	rwlock_init(&eb->lock);
-	atomic_set(&eb->write_locks, 0);
-	atomic_set(&eb->read_locks, 0);
 	atomic_set(&eb->blocking_readers, 0);
-	atomic_set(&eb->blocking_writers, 0);
-	atomic_set(&eb->spinning_readers, 0);
-	atomic_set(&eb->spinning_writers, 0);
-	eb->lock_nested = 0;
+	eb->blocking_writers = 0;
+	eb->lock_nested = false;
 	init_waitqueue_head(&eb->write_lock_wq);
 	init_waitqueue_head(&eb->read_lock_wq);
 
@@ -4721,6 +4903,13 @@
 		> MAX_INLINE_EXTENT_BUFFER_SIZE);
 	BUG_ON(len > MAX_INLINE_EXTENT_BUFFER_SIZE);
 
+#ifdef CONFIG_BTRFS_DEBUG
+	eb->spinning_writers = 0;
+	atomic_set(&eb->spinning_readers, 0);
+	atomic_set(&eb->read_locks, 0);
+	eb->write_locks = 0;
+#endif
+
 	return eb;
 }
 
@@ -4908,13 +5097,6 @@
 	check_buffer_tree_ref(eb);
 	set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
 
-	/*
-	 * We will free dummy extent buffer's if they come into
-	 * free_extent_buffer with a ref count of 2, but if we are using this we
-	 * want the buffers to stay in memory until we're done with them, so
-	 * bump the ref count again.
-	 */
-	atomic_inc(&eb->refs);
 	return eb;
 free_eb:
 	btrfs_release_extent_buffer(eb);
@@ -5096,7 +5278,9 @@
 
 	while (1) {
 		refs = atomic_read(&eb->refs);
-		if (refs <= 3)
+		if ((!test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags) && refs <= 3)
+		    || (test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags) &&
+			refs == 1))
 			break;
 		old = atomic_cmpxchg(&eb->refs, refs, refs - 1);
 		if (old == refs)
@@ -5105,10 +5289,6 @@
 
 	spin_lock(&eb->refs_lock);
 	if (atomic_read(&eb->refs) == 2 &&
-	    test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags))
-		atomic_dec(&eb->refs);
-
-	if (atomic_read(&eb->refs) == 2 &&
 	    test_bit(EXTENT_BUFFER_STALE, &eb->bflags) &&
 	    !extent_buffer_under_io(eb) &&
 	    test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
@@ -5153,11 +5333,9 @@
 
 		clear_page_dirty_for_io(page);
 		xa_lock_irq(&page->mapping->i_pages);
-		if (!PageDirty(page)) {
-			radix_tree_tag_clear(&page->mapping->i_pages,
-						page_index(page),
-						PAGECACHE_TAG_DIRTY);
-		}
+		if (!PageDirty(page))
+			__xa_clear_mark(&page->mapping->i_pages,
+					page_index(page), PAGECACHE_TAG_DIRTY);
 		xa_unlock_irq(&page->mapping->i_pages);
 		ClearPageError(page);
 		unlock_page(page);
@@ -5165,11 +5343,11 @@
 	WARN_ON(atomic_read(&eb->refs) == 0);
 }
 
-int set_extent_buffer_dirty(struct extent_buffer *eb)
+bool set_extent_buffer_dirty(struct extent_buffer *eb)
 {
 	int i;
 	int num_pages;
-	int was_dirty = 0;
+	bool was_dirty;
 
 	check_buffer_tree_ref(eb);
 
@@ -5179,8 +5357,15 @@
 	WARN_ON(atomic_read(&eb->refs) == 0);
 	WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags));
 
+	if (!was_dirty)
+		for (i = 0; i < num_pages; i++)
+			set_page_dirty(eb->pages[i]);
+
+#ifdef CONFIG_BTRFS_DEBUG
 	for (i = 0; i < num_pages; i++)
-		set_page_dirty(eb->pages[i]);
+		ASSERT(PageDirty(eb->pages[i]));
+#endif
+
 	return was_dirty;
 }
 
@@ -5213,8 +5398,7 @@
 	}
 }
 
-int read_extent_buffer_pages(struct extent_io_tree *tree,
-			     struct extent_buffer *eb, int wait, int mirror_num)
+int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num)
 {
 	int i;
 	struct page *page;
@@ -5226,6 +5410,7 @@
 	unsigned long num_reads = 0;
 	struct bio *bio = NULL;
 	unsigned long bio_flags = 0;
+	struct extent_io_tree *tree = &BTRFS_I(eb->fs_info->btree_inode)->io_tree;
 
 	if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
 		return 0;
@@ -5329,7 +5514,7 @@
 	struct page *page;
 	char *kaddr;
 	char *dst = (char *)dstv;
-	size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
+	size_t start_offset = offset_in_page(eb->start);
 	unsigned long i = (start_offset + start) >> PAGE_SHIFT;
 
 	if (start + len > eb->len) {
@@ -5339,7 +5524,7 @@
 		return;
 	}
 
-	offset = (start_offset + start) & (PAGE_SIZE - 1);
+	offset = offset_in_page(start_offset + start);
 
 	while (len > 0) {
 		page = eb->pages[i];
@@ -5364,14 +5549,14 @@
 	struct page *page;
 	char *kaddr;
 	char __user *dst = (char __user *)dstv;
-	size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
+	size_t start_offset = offset_in_page(eb->start);
 	unsigned long i = (start_offset + start) >> PAGE_SHIFT;
 	int ret = 0;
 
 	WARN_ON(start > eb->len);
 	WARN_ON(start + len > eb->start + eb->len);
 
-	offset = (start_offset + start) & (PAGE_SIZE - 1);
+	offset = offset_in_page(start_offset + start);
 
 	while (len > 0) {
 		page = eb->pages[i];
@@ -5402,10 +5587,10 @@
 			      char **map, unsigned long *map_start,
 			      unsigned long *map_len)
 {
-	size_t offset = start & (PAGE_SIZE - 1);
+	size_t offset;
 	char *kaddr;
 	struct page *p;
-	size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
+	size_t start_offset = offset_in_page(eb->start);
 	unsigned long i = (start_offset + start) >> PAGE_SHIFT;
 	unsigned long end_i = (start_offset + start + min_len - 1) >>
 		PAGE_SHIFT;
@@ -5442,14 +5627,14 @@
 	struct page *page;
 	char *kaddr;
 	char *ptr = (char *)ptrv;
-	size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
+	size_t start_offset = offset_in_page(eb->start);
 	unsigned long i = (start_offset + start) >> PAGE_SHIFT;
 	int ret = 0;
 
 	WARN_ON(start > eb->len);
 	WARN_ON(start + len > eb->start + eb->len);
 
-	offset = (start_offset + start) & (PAGE_SIZE - 1);
+	offset = offset_in_page(start_offset + start);
 
 	while (len > 0) {
 		page = eb->pages[i];
@@ -5498,13 +5683,13 @@
 	struct page *page;
 	char *kaddr;
 	char *src = (char *)srcv;
-	size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
+	size_t start_offset = offset_in_page(eb->start);
 	unsigned long i = (start_offset + start) >> PAGE_SHIFT;
 
 	WARN_ON(start > eb->len);
 	WARN_ON(start + len > eb->start + eb->len);
 
-	offset = (start_offset + start) & (PAGE_SIZE - 1);
+	offset = offset_in_page(start_offset + start);
 
 	while (len > 0) {
 		page = eb->pages[i];
@@ -5528,13 +5713,13 @@
 	size_t offset;
 	struct page *page;
 	char *kaddr;
-	size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
+	size_t start_offset = offset_in_page(eb->start);
 	unsigned long i = (start_offset + start) >> PAGE_SHIFT;
 
 	WARN_ON(start > eb->len);
 	WARN_ON(start + len > eb->start + eb->len);
 
-	offset = (start_offset + start) & (PAGE_SIZE - 1);
+	offset = offset_in_page(start_offset + start);
 
 	while (len > 0) {
 		page = eb->pages[i];
@@ -5573,13 +5758,12 @@
 	size_t offset;
 	struct page *page;
 	char *kaddr;
-	size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
+	size_t start_offset = offset_in_page(dst->start);
 	unsigned long i = (start_offset + dst_offset) >> PAGE_SHIFT;
 
 	WARN_ON(src->len != dst_len);
 
-	offset = (start_offset + dst_offset) &
-		(PAGE_SIZE - 1);
+	offset = offset_in_page(start_offset + dst_offset);
 
 	while (len > 0) {
 		page = dst->pages[i];
@@ -5615,7 +5799,7 @@
 				    unsigned long *page_index,
 				    size_t *page_offset)
 {
-	size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1);
+	size_t start_offset = offset_in_page(eb->start);
 	size_t byte_offset = BIT_BYTE(nr);
 	size_t offset;
 
@@ -5627,7 +5811,7 @@
 	offset = start_offset + start + byte_offset;
 
 	*page_index = offset >> PAGE_SHIFT;
-	*page_offset = offset & (PAGE_SIZE - 1);
+	*page_offset = offset_in_page(offset);
 }
 
 /**
@@ -5769,7 +5953,7 @@
 	size_t cur;
 	size_t dst_off_in_page;
 	size_t src_off_in_page;
-	size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
+	size_t start_offset = offset_in_page(dst->start);
 	unsigned long dst_i;
 	unsigned long src_i;
 
@@ -5777,20 +5961,18 @@
 		btrfs_err(fs_info,
 			"memmove bogus src_offset %lu move len %lu dst len %lu",
 			 src_offset, len, dst->len);
-		BUG_ON(1);
+		BUG();
 	}
 	if (dst_offset + len > dst->len) {
 		btrfs_err(fs_info,
 			"memmove bogus dst_offset %lu move len %lu dst len %lu",
 			 dst_offset, len, dst->len);
-		BUG_ON(1);
+		BUG();
 	}
 
 	while (len > 0) {
-		dst_off_in_page = (start_offset + dst_offset) &
-			(PAGE_SIZE - 1);
-		src_off_in_page = (start_offset + src_offset) &
-			(PAGE_SIZE - 1);
+		dst_off_in_page = offset_in_page(start_offset + dst_offset);
+		src_off_in_page = offset_in_page(start_offset + src_offset);
 
 		dst_i = (start_offset + dst_offset) >> PAGE_SHIFT;
 		src_i = (start_offset + src_offset) >> PAGE_SHIFT;
@@ -5818,7 +6000,7 @@
 	size_t src_off_in_page;
 	unsigned long dst_end = dst_offset + len - 1;
 	unsigned long src_end = src_offset + len - 1;
-	size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1);
+	size_t start_offset = offset_in_page(dst->start);
 	unsigned long dst_i;
 	unsigned long src_i;
 
@@ -5826,13 +6008,13 @@
 		btrfs_err(fs_info,
 			  "memmove bogus src_offset %lu move len %lu len %lu",
 			  src_offset, len, dst->len);
-		BUG_ON(1);
+		BUG();
 	}
 	if (dst_offset + len > dst->len) {
 		btrfs_err(fs_info,
 			  "memmove bogus dst_offset %lu move len %lu len %lu",
 			  dst_offset, len, dst->len);
-		BUG_ON(1);
+		BUG();
 	}
 	if (dst_offset < src_offset) {
 		memcpy_extent_buffer(dst, dst_offset, src_offset, len);
@@ -5842,10 +6024,8 @@
 		dst_i = (start_offset + dst_end) >> PAGE_SHIFT;
 		src_i = (start_offset + src_end) >> PAGE_SHIFT;
 
-		dst_off_in_page = (start_offset + dst_end) &
-			(PAGE_SIZE - 1);
-		src_off_in_page = (start_offset + src_end) &
-			(PAGE_SIZE - 1);
+		dst_off_in_page = offset_in_page(start_offset + dst_end);
+		src_off_in_page = offset_in_page(start_offset + src_end);
 
 		cur = min_t(unsigned long, len, src_off_in_page + 1);
 		cur = min(cur, dst_off_in_page + 1);
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index b4d03e6..cf3424d 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -9,26 +9,32 @@
 
 /* bits for the extent state */
 #define EXTENT_DIRTY		(1U << 0)
-#define EXTENT_WRITEBACK	(1U << 1)
-#define EXTENT_UPTODATE		(1U << 2)
-#define EXTENT_LOCKED		(1U << 3)
-#define EXTENT_NEW		(1U << 4)
-#define EXTENT_DELALLOC		(1U << 5)
-#define EXTENT_DEFRAG		(1U << 6)
-#define EXTENT_BOUNDARY		(1U << 9)
-#define EXTENT_NODATASUM	(1U << 10)
-#define EXTENT_CLEAR_META_RESV	(1U << 11)
-#define EXTENT_FIRST_DELALLOC	(1U << 12)
-#define EXTENT_NEED_WAIT	(1U << 13)
-#define EXTENT_DAMAGED		(1U << 14)
-#define EXTENT_NORESERVE	(1U << 15)
-#define EXTENT_QGROUP_RESERVED	(1U << 16)
-#define EXTENT_CLEAR_DATA_RESV	(1U << 17)
-#define EXTENT_DELALLOC_NEW	(1U << 18)
-#define EXTENT_IOBITS		(EXTENT_LOCKED | EXTENT_WRITEBACK)
+#define EXTENT_UPTODATE		(1U << 1)
+#define EXTENT_LOCKED		(1U << 2)
+#define EXTENT_NEW		(1U << 3)
+#define EXTENT_DELALLOC		(1U << 4)
+#define EXTENT_DEFRAG		(1U << 5)
+#define EXTENT_BOUNDARY		(1U << 6)
+#define EXTENT_NODATASUM	(1U << 7)
+#define EXTENT_CLEAR_META_RESV	(1U << 8)
+#define EXTENT_NEED_WAIT	(1U << 9)
+#define EXTENT_DAMAGED		(1U << 10)
+#define EXTENT_NORESERVE	(1U << 11)
+#define EXTENT_QGROUP_RESERVED	(1U << 12)
+#define EXTENT_CLEAR_DATA_RESV	(1U << 13)
+#define EXTENT_DELALLOC_NEW	(1U << 14)
 #define EXTENT_DO_ACCOUNTING    (EXTENT_CLEAR_META_RESV | \
 				 EXTENT_CLEAR_DATA_RESV)
-#define EXTENT_CTLBITS		(EXTENT_DO_ACCOUNTING | EXTENT_FIRST_DELALLOC)
+#define EXTENT_CTLBITS		(EXTENT_DO_ACCOUNTING)
+
+/*
+ * Redefined bits above which are used only in the device allocation tree,
+ * shouldn't be using EXTENT_LOCKED / EXTENT_BOUNDARY / EXTENT_CLEAR_META_RESV
+ * / EXTENT_CLEAR_DATA_RESV because they have special meaning to the bit
+ * manipulation functions
+ */
+#define CHUNK_ALLOCATED EXTENT_DIRTY
+#define CHUNK_TRIMMED   EXTENT_DEFRAG
 
 /*
  * flags for bio submission. The high bits indicate the compression
@@ -37,18 +43,22 @@
 #define EXTENT_BIO_COMPRESSED 1
 #define EXTENT_BIO_FLAG_SHIFT 16
 
-/* these are bit numbers for test/set bit */
-#define EXTENT_BUFFER_UPTODATE 0
-#define EXTENT_BUFFER_DIRTY 2
-#define EXTENT_BUFFER_CORRUPT 3
-#define EXTENT_BUFFER_READAHEAD 4	/* this got triggered by readahead */
-#define EXTENT_BUFFER_TREE_REF 5
-#define EXTENT_BUFFER_STALE 6
-#define EXTENT_BUFFER_WRITEBACK 7
-#define EXTENT_BUFFER_READ_ERR 8        /* read IO error */
-#define EXTENT_BUFFER_UNMAPPED 9
-#define EXTENT_BUFFER_IN_TREE 10
-#define EXTENT_BUFFER_WRITE_ERR 11    /* write IO error */
+enum {
+	EXTENT_BUFFER_UPTODATE,
+	EXTENT_BUFFER_DIRTY,
+	EXTENT_BUFFER_CORRUPT,
+	/* this got triggered by readahead */
+	EXTENT_BUFFER_READAHEAD,
+	EXTENT_BUFFER_TREE_REF,
+	EXTENT_BUFFER_STALE,
+	EXTENT_BUFFER_WRITEBACK,
+	/* read IO error */
+	EXTENT_BUFFER_READ_ERR,
+	EXTENT_BUFFER_UNMAPPED,
+	EXTENT_BUFFER_IN_TREE,
+	/* write IO error */
+	EXTENT_BUFFER_WRITE_ERR,
+};
 
 /* these are flags for __process_pages_contig */
 #define PAGE_UNLOCK		(1 << 0)
@@ -85,54 +95,43 @@
 struct btrfs_io_bio;
 struct io_failure_record;
 
-typedef	blk_status_t (extent_submit_bio_hook_t)(void *private_data, struct bio *bio,
-				       int mirror_num, unsigned long bio_flags,
-				       u64 bio_offset);
 
 typedef blk_status_t (extent_submit_bio_start_t)(void *private_data,
 		struct bio *bio, u64 bio_offset);
 
 struct extent_io_ops {
 	/*
-	 * The following callbacks must be allways defined, the function
+	 * The following callbacks must be always defined, the function
 	 * pointer will be called unconditionally.
 	 */
-	extent_submit_bio_hook_t *submit_bio_hook;
+	blk_status_t (*submit_bio_hook)(struct inode *inode, struct bio *bio,
+					int mirror_num, unsigned long bio_flags);
 	int (*readpage_end_io_hook)(struct btrfs_io_bio *io_bio, u64 phy_offset,
 				    struct page *page, u64 start, u64 end,
 				    int mirror);
-	int (*readpage_io_failed_hook)(struct page *page, int failed_mirror);
+};
 
-	/*
-	 * Optional hooks, called if the pointer is not NULL
-	 */
-	int (*fill_delalloc)(void *private_data, struct page *locked_page,
-			     u64 start, u64 end, int *page_started,
-			     unsigned long *nr_written,
-			     struct writeback_control *wbc);
-
-	int (*writepage_start_hook)(struct page *page, u64 start, u64 end);
-	void (*writepage_end_io_hook)(struct page *page, u64 start, u64 end,
-				      struct extent_state *state, int uptodate);
-	void (*set_bit_hook)(void *private_data, struct extent_state *state,
-			     unsigned *bits);
-	void (*clear_bit_hook)(void *private_data,
-			struct extent_state *state,
-			unsigned *bits);
-	void (*merge_extent_hook)(void *private_data,
-				  struct extent_state *new,
-				  struct extent_state *other);
-	void (*split_extent_hook)(void *private_data,
-				  struct extent_state *orig, u64 split);
-	void (*check_extent_io_range)(void *private_data, const char *caller,
-				      u64 start, u64 end);
+enum {
+	IO_TREE_FS_INFO_FREED_EXTENTS0,
+	IO_TREE_FS_INFO_FREED_EXTENTS1,
+	IO_TREE_INODE_IO,
+	IO_TREE_INODE_IO_FAILURE,
+	IO_TREE_RELOC_BLOCKS,
+	IO_TREE_TRANS_DIRTY_PAGES,
+	IO_TREE_ROOT_DIRTY_LOG_PAGES,
+	IO_TREE_SELFTEST,
 };
 
 struct extent_io_tree {
 	struct rb_root state;
+	struct btrfs_fs_info *fs_info;
 	void *private_data;
 	u64 dirty_bytes;
-	int track_uptodate;
+	bool track_uptodate;
+
+	/* Who owns this io tree, should be one of IO_TREE_* */
+	u8 owner;
+
 	spinlock_t lock;
 	const struct extent_io_ops *ops;
 };
@@ -168,14 +167,9 @@
 	struct rcu_head rcu_head;
 	pid_t lock_owner;
 
-	/* count of read lock holders on the extent buffer */
-	atomic_t write_locks;
-	atomic_t read_locks;
-	atomic_t blocking_writers;
+	int blocking_writers;
 	atomic_t blocking_readers;
-	atomic_t spinning_readers;
-	atomic_t spinning_writers;
-	short lock_nested;
+	bool lock_nested;
 	/* >= 0 if eb belongs to a log tree, -1 otherwise */
 	short log_index;
 
@@ -193,6 +187,10 @@
 	wait_queue_head_t read_lock_wq;
 	struct page *pages[INLINE_EXTENT_BUFFER_PAGES];
 #ifdef CONFIG_BTRFS_DEBUG
+	int spinning_writers;
+	atomic_t spinning_readers;
+	atomic_t read_locks;
+	int write_locks;
 	struct list_head leak_list;
 #endif
 };
@@ -261,7 +259,10 @@
 					  u64 start, u64 len,
 					  int create);
 
-void extent_io_tree_init(struct extent_io_tree *tree, void *private_data);
+void extent_io_tree_init(struct btrfs_fs_info *fs_info,
+			 struct extent_io_tree *tree, unsigned int owner,
+			 void *private_data);
+void extent_io_tree_release(struct extent_io_tree *tree);
 int try_release_extent_mapping(struct page *page, gfp_t mask);
 int try_release_extent_buffer(struct page *page);
 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
@@ -331,6 +332,8 @@
 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 		   unsigned bits, u64 *failed_start,
 		   struct extent_state **cached_state, gfp_t mask);
+int set_extent_bits_nowait(struct extent_io_tree *tree, u64 start, u64 end,
+			   unsigned bits);
 
 static inline int set_extent_bits(struct extent_io_tree *tree, u64 start,
 		u64 end, unsigned bits)
@@ -353,11 +356,11 @@
 }
 
 static inline int clear_extent_dirty(struct extent_io_tree *tree, u64 start,
-		u64 end)
+				     u64 end, struct extent_state **cached)
 {
 	return clear_extent_bit(tree, start, end,
 				EXTENT_DIRTY | EXTENT_DELALLOC |
-				EXTENT_DO_ACCOUNTING, 0, 0, NULL);
+				EXTENT_DO_ACCOUNTING, 0, 0, cached);
 }
 
 int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
@@ -398,6 +401,8 @@
 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
 			  u64 *start_ret, u64 *end_ret, unsigned bits,
 			  struct extent_state **cached_state);
+void find_first_clear_extent_bit(struct extent_io_tree *tree, u64 start,
+				 u64 *start_ret, u64 *end_ret, unsigned bits);
 int extent_invalidatepage(struct extent_io_tree *tree,
 			  struct page *page, unsigned long offset);
 int extent_write_full_page(struct page *page, struct writeback_control *wbc);
@@ -427,8 +432,7 @@
 #define WAIT_NONE	0
 #define WAIT_COMPLETE	1
 #define WAIT_PAGE_LOCK	2
-int read_extent_buffer_pages(struct extent_io_tree *tree,
-			     struct extent_buffer *eb, int wait,
+int read_extent_buffer_pages(struct extent_buffer *eb, int wait,
 			     int mirror_num);
 void wait_on_extent_buffer_writeback(struct extent_buffer *eb);
 
@@ -479,7 +483,7 @@
 void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
 				unsigned long pos, unsigned long len);
 void clear_extent_buffer_dirty(struct extent_buffer *eb);
-int set_extent_buffer_dirty(struct extent_buffer *eb);
+bool set_extent_buffer_dirty(struct extent_buffer *eb);
 void set_extent_buffer_uptodate(struct extent_buffer *eb);
 void clear_extent_buffer_uptodate(struct extent_buffer *eb);
 int extent_buffer_under_io(struct extent_buffer *eb);
@@ -490,10 +494,10 @@
 void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end);
 void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end);
 void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
-				 u64 delalloc_end, struct page *locked_page,
-				 unsigned bits_to_clear,
-				 unsigned long page_ops);
-struct bio *btrfs_bio_alloc(struct block_device *bdev, u64 first_byte);
+				  struct page *locked_page,
+				  unsigned bits_to_clear,
+				  unsigned long page_ops);
+struct bio *btrfs_bio_alloc(u64 first_byte);
 struct bio *btrfs_io_bio_alloc(unsigned int nr_iovecs);
 struct bio *btrfs_bio_clone(struct bio *bio);
 struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size);
@@ -509,8 +513,7 @@
 		     struct extent_io_tree *io_tree, u64 start,
 		     struct page *page, u64 ino, unsigned int pg_offset);
 void end_extent_writepage(struct page *page, int err, u64 start, u64 end);
-int repair_eb_io_failure(struct btrfs_fs_info *fs_info,
-			 struct extent_buffer *eb, int mirror_num);
+int btrfs_repair_eb_io_failure(struct extent_buffer *eb, int mirror_num);
 
 /*
  * When IO fails, either with EIO or csum verification fails, we
@@ -546,10 +549,9 @@
 		    struct extent_io_tree *io_tree,
 		    struct io_failure_record *rec);
 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
-noinline u64 find_lock_delalloc_range(struct inode *inode,
-				      struct extent_io_tree *tree,
-				      struct page *locked_page, u64 *start,
-				      u64 *end, u64 max_bytes);
+bool find_lock_delalloc_range(struct inode *inode,
+			     struct page *locked_page, u64 *start,
+			     u64 *end);
 #endif
 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
 					       u64 start);
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 6648d55..9d30acc 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -4,6 +4,7 @@
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include "ctree.h"
+#include "volumes.h"
 #include "extent_map.h"
 #include "compression.h"
 
@@ -34,7 +35,7 @@
  */
 void extent_map_tree_init(struct extent_map_tree *tree)
 {
-	tree->map = RB_ROOT;
+	tree->map = RB_ROOT_CACHED;
 	INIT_LIST_HEAD(&tree->modified_extents);
 	rwlock_init(&tree->lock);
 }
@@ -90,24 +91,27 @@
 	return start + len;
 }
 
-static int tree_insert(struct rb_root *root, struct extent_map *em)
+static int tree_insert(struct rb_root_cached *root, struct extent_map *em)
 {
-	struct rb_node **p = &root->rb_node;
+	struct rb_node **p = &root->rb_root.rb_node;
 	struct rb_node *parent = NULL;
 	struct extent_map *entry = NULL;
 	struct rb_node *orig_parent = NULL;
 	u64 end = range_end(em->start, em->len);
+	bool leftmost = true;
 
 	while (*p) {
 		parent = *p;
 		entry = rb_entry(parent, struct extent_map, rb_node);
 
-		if (em->start < entry->start)
+		if (em->start < entry->start) {
 			p = &(*p)->rb_left;
-		else if (em->start >= extent_map_end(entry))
+		} else if (em->start >= extent_map_end(entry)) {
 			p = &(*p)->rb_right;
-		else
+			leftmost = false;
+		} else {
 			return -EEXIST;
+		}
 	}
 
 	orig_parent = parent;
@@ -130,7 +134,7 @@
 			return -EEXIST;
 
 	rb_link_node(&em->rb_node, orig_parent, p);
-	rb_insert_color(&em->rb_node, root);
+	rb_insert_color_cached(&em->rb_node, root, leftmost);
 	return 0;
 }
 
@@ -207,6 +211,9 @@
 	if (!list_empty(&prev->list) || !list_empty(&next->list))
 		return 0;
 
+	ASSERT(next->block_start != EXTENT_MAP_DELALLOC &&
+	       prev->block_start != EXTENT_MAP_DELALLOC);
+
 	if (extent_map_end(prev) == next->start &&
 	    prev->flags == next->flags &&
 	    prev->bdev == next->bdev &&
@@ -214,8 +221,6 @@
 	      prev->block_start == EXTENT_MAP_HOLE) ||
 	     (next->block_start == EXTENT_MAP_INLINE &&
 	      prev->block_start == EXTENT_MAP_INLINE) ||
-	     (next->block_start == EXTENT_MAP_DELALLOC &&
-	      prev->block_start == EXTENT_MAP_DELALLOC) ||
 	     (next->block_start < EXTENT_MAP_LAST_BYTE - 1 &&
 	      next->block_start == extent_map_block_end(prev)))) {
 		return 1;
@@ -242,7 +247,7 @@
 			em->mod_start = merge->mod_start;
 			em->generation = max(em->generation, merge->generation);
 
-			rb_erase(&merge->rb_node, &tree->map);
+			rb_erase_cached(&merge->rb_node, &tree->map);
 			RB_CLEAR_NODE(&merge->rb_node);
 			free_extent_map(merge);
 		}
@@ -254,7 +259,7 @@
 	if (rb && mergable_maps(em, merge)) {
 		em->len += merge->len;
 		em->block_len += merge->block_len;
-		rb_erase(&merge->rb_node, &tree->map);
+		rb_erase_cached(&merge->rb_node, &tree->map);
 		RB_CLEAR_NODE(&merge->rb_node);
 		em->mod_len = (merge->mod_start + merge->mod_len) - em->mod_start;
 		em->generation = max(em->generation, merge->generation);
@@ -333,6 +338,37 @@
 		try_merge_map(tree, em);
 }
 
+static void extent_map_device_set_bits(struct extent_map *em, unsigned bits)
+{
+	struct map_lookup *map = em->map_lookup;
+	u64 stripe_size = em->orig_block_len;
+	int i;
+
+	for (i = 0; i < map->num_stripes; i++) {
+		struct btrfs_bio_stripe *stripe = &map->stripes[i];
+		struct btrfs_device *device = stripe->dev;
+
+		set_extent_bits_nowait(&device->alloc_state, stripe->physical,
+				 stripe->physical + stripe_size - 1, bits);
+	}
+}
+
+static void extent_map_device_clear_bits(struct extent_map *em, unsigned bits)
+{
+	struct map_lookup *map = em->map_lookup;
+	u64 stripe_size = em->orig_block_len;
+	int i;
+
+	for (i = 0; i < map->num_stripes; i++) {
+		struct btrfs_bio_stripe *stripe = &map->stripes[i];
+		struct btrfs_device *device = stripe->dev;
+
+		__clear_extent_bit(&device->alloc_state, stripe->physical,
+				   stripe->physical + stripe_size - 1, bits,
+				   0, 0, NULL, GFP_NOWAIT, NULL);
+	}
+}
+
 /**
  * add_extent_mapping - add new extent map to the extent tree
  * @tree:	tree to insert new map in
@@ -348,11 +384,17 @@
 {
 	int ret = 0;
 
+	lockdep_assert_held_write(&tree->lock);
+
 	ret = tree_insert(&tree->map, em);
 	if (ret)
 		goto out;
 
 	setup_extent_mapping(tree, em, modified);
+	if (test_bit(EXTENT_FLAG_FS_MAPPING, &em->flags)) {
+		extent_map_device_set_bits(em, CHUNK_ALLOCATED);
+		extent_map_device_clear_bits(em, CHUNK_TRIMMED);
+	}
 out:
 	return ret;
 }
@@ -367,7 +409,7 @@
 	struct rb_node *next = NULL;
 	u64 end = range_end(start, len);
 
-	rb_node = __tree_search(&tree->map, start, &prev, &next);
+	rb_node = __tree_search(&tree->map.rb_root, start, &prev, &next);
 	if (!rb_node) {
 		if (prev)
 			rb_node = prev;
@@ -428,16 +470,15 @@
  * Removes @em from @tree.  No reference counts are dropped, and no checks
  * are done to see if the range is in use
  */
-int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em)
+void remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em)
 {
-	int ret = 0;
-
 	WARN_ON(test_bit(EXTENT_FLAG_PINNED, &em->flags));
-	rb_erase(&em->rb_node, &tree->map);
+	rb_erase_cached(&em->rb_node, &tree->map);
 	if (!test_bit(EXTENT_FLAG_LOGGING, &em->flags))
 		list_del_init(&em->list);
+	if (test_bit(EXTENT_FLAG_FS_MAPPING, &em->flags))
+		extent_map_device_clear_bits(em, CHUNK_ALLOCATED);
 	RB_CLEAR_NODE(&em->rb_node);
-	return ret;
 }
 
 void replace_extent_mapping(struct extent_map_tree *tree,
@@ -449,7 +490,7 @@
 	ASSERT(extent_map_in_tree(cur));
 	if (!test_bit(EXTENT_FLAG_LOGGING, &cur->flags))
 		list_del_init(&cur->list);
-	rb_replace_node(&cur->rb_node, &new->rb_node, &tree->map);
+	rb_replace_node_cached(&cur->rb_node, &new->rb_node, &tree->map);
 	RB_CLEAR_NODE(&cur->rb_node);
 
 	setup_extent_mapping(tree, new, modified);
@@ -475,7 +516,8 @@
 	return container_of(prev, struct extent_map, rb_node);
 }
 
-/* helper for btfs_get_extent.  Given an existing extent in the tree,
+/*
+ * Helper for btrfs_get_extent.  Given an existing extent in the tree,
  * the existing extent is the nearest extent to map_start,
  * and an extent that you want to insert, deal with overlap and insert
  * the best fitted new extent into the tree.
diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h
index 25d985e..473f039 100644
--- a/fs/btrfs/extent_map.h
+++ b/fs/btrfs/extent_map.h
@@ -9,15 +9,23 @@
 #define EXTENT_MAP_LAST_BYTE ((u64)-4)
 #define EXTENT_MAP_HOLE ((u64)-3)
 #define EXTENT_MAP_INLINE ((u64)-2)
+/* used only during fiemap calls */
 #define EXTENT_MAP_DELALLOC ((u64)-1)
 
-/* bits for the flags field */
-#define EXTENT_FLAG_PINNED 0 /* this entry not yet on disk, don't free it */
-#define EXTENT_FLAG_COMPRESSED 1
-#define EXTENT_FLAG_PREALLOC 3 /* pre-allocated extent */
-#define EXTENT_FLAG_LOGGING 4 /* Logging this extent */
-#define EXTENT_FLAG_FILLING 5 /* Filling in a preallocated extent */
-#define EXTENT_FLAG_FS_MAPPING 6 /* filesystem extent mapping type */
+/* bits for the extent_map::flags field */
+enum {
+	/* this entry not yet on disk, don't free it */
+	EXTENT_FLAG_PINNED,
+	EXTENT_FLAG_COMPRESSED,
+	/* pre-allocated extent */
+	EXTENT_FLAG_PREALLOC,
+	/* Logging this extent */
+	EXTENT_FLAG_LOGGING,
+	/* Filling in a preallocated extent */
+	EXTENT_FLAG_FILLING,
+	/* filesystem extent mapping type */
+	EXTENT_FLAG_FS_MAPPING,
+};
 
 struct extent_map {
 	struct rb_node rb_node;
@@ -49,7 +57,7 @@
 };
 
 struct extent_map_tree {
-	struct rb_root map;
+	struct rb_root_cached map;
 	struct list_head modified_extents;
 	rwlock_t lock;
 };
@@ -78,7 +86,7 @@
 					 u64 start, u64 len);
 int add_extent_mapping(struct extent_map_tree *tree,
 		       struct extent_map *em, int modified);
-int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
+void remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
 void replace_extent_mapping(struct extent_map_tree *tree,
 			    struct extent_map *cur,
 			    struct extent_map *new,
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index ba74827..1a599f5 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -7,6 +7,8 @@
 #include <linux/slab.h>
 #include <linux/pagemap.h>
 #include <linux/highmem.h>
+#include <linux/sched/mm.h>
+#include <crypto/hash.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -21,9 +23,13 @@
 #define MAX_CSUM_ITEMS(r, size) (min_t(u32, __MAX_CSUM_ITEMS(r, size), \
 				       PAGE_SIZE))
 
-#define MAX_ORDERED_SUM_BYTES(fs_info) ((PAGE_SIZE - \
-				   sizeof(struct btrfs_ordered_sum)) / \
-				   sizeof(u32) * (fs_info)->sectorsize)
+static inline u32 max_ordered_sum_bytes(struct btrfs_fs_info *fs_info,
+					u16 csum_size)
+{
+	u32 ncsums = (PAGE_SIZE - sizeof(struct btrfs_ordered_sum)) / csum_size;
+
+	return ncsums * fs_info->sectorsize;
+}
 
 int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
 			     struct btrfs_root *root,
@@ -142,13 +148,8 @@
 	return ret;
 }
 
-static void btrfs_io_bio_endio_readpage(struct btrfs_io_bio *bio, int err)
-{
-	kfree(bio->csum_allocated);
-}
-
 static blk_status_t __btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
-				   u64 logical_offset, u32 *dst, int dio)
+				   u64 logical_offset, u8 *dst, int dio)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct bio_vec bvec;
@@ -175,20 +176,18 @@
 	nblocks = bio->bi_iter.bi_size >> inode->i_sb->s_blocksize_bits;
 	if (!dst) {
 		if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) {
-			btrfs_bio->csum_allocated = kmalloc_array(nblocks,
-					csum_size, GFP_NOFS);
-			if (!btrfs_bio->csum_allocated) {
+			btrfs_bio->csum = kmalloc_array(nblocks, csum_size,
+							GFP_NOFS);
+			if (!btrfs_bio->csum) {
 				btrfs_free_path(path);
 				return BLK_STS_RESOURCE;
 			}
-			btrfs_bio->csum = btrfs_bio->csum_allocated;
-			btrfs_bio->end_io = btrfs_io_bio_endio_readpage;
 		} else {
 			btrfs_bio->csum = btrfs_bio->csum_inline;
 		}
 		csum = btrfs_bio->csum;
 	} else {
-		csum = (u8 *)dst;
+		csum = dst;
 	}
 
 	if (bio->bi_iter.bi_size > PAGE_SIZE * 8)
@@ -217,7 +216,7 @@
 		if (!dio)
 			offset = page_offset(bvec.bv_page) + bvec.bv_offset;
 		count = btrfs_find_ordered_sum(inode, offset, disk_bytenr,
-					       (u32 *)csum, nblocks);
+					       csum, nblocks);
 		if (count)
 			goto found;
 
@@ -289,7 +288,8 @@
 	return 0;
 }
 
-blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u32 *dst)
+blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
+				   u8 *dst)
 {
 	return __btrfs_lookup_bio_sums(inode, bio, 0, dst, 0);
 }
@@ -380,7 +380,7 @@
 				      struct btrfs_csum_item);
 		while (start < csum_end) {
 			size = min_t(size_t, csum_end - start,
-				     MAX_ORDERED_SUM_BYTES(fs_info));
+				     max_ordered_sum_bytes(fs_info, csum_size));
 			sums = kzalloc(btrfs_ordered_sum_size(fs_info, size),
 				       GFP_NOFS);
 			if (!sums) {
@@ -419,10 +419,21 @@
 	return ret;
 }
 
+/*
+ * btrfs_csum_one_bio - Calculates checksums of the data contained inside a bio
+ * @inode:	 Owner of the data inside the bio
+ * @bio:	 Contains the data to be checksummed
+ * @file_start:  offset in file this bio begins to describe
+ * @contig:	 Boolean. If true/1 means all bio vecs in this bio are
+ *		 contiguous and they begin at @file_start in the file. False/0
+ *		 means this bio can contains potentially discontigous bio vecs
+ *		 so the logical offset of each should be calculated separately.
+ */
 blk_status_t btrfs_csum_one_bio(struct inode *inode, struct bio *bio,
 		       u64 file_start, int contig)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
 	struct btrfs_ordered_sum *sums;
 	struct btrfs_ordered_extent *ordered = NULL;
 	char *data;
@@ -434,9 +445,14 @@
 	unsigned long this_sum_bytes = 0;
 	int i;
 	u64 offset;
+	unsigned nofs_flag;
+	const u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
 
-	sums = kzalloc(btrfs_ordered_sum_size(fs_info, bio->bi_iter.bi_size),
-		       GFP_NOFS);
+	nofs_flag = memalloc_nofs_save();
+	sums = kvzalloc(btrfs_ordered_sum_size(fs_info, bio->bi_iter.bi_size),
+		       GFP_KERNEL);
+	memalloc_nofs_restore(nofs_flag);
+
 	if (!sums)
 		return BLK_STS_RESOURCE;
 
@@ -451,6 +467,8 @@
 	sums->bytenr = (u64)bio->bi_iter.bi_sector << 9;
 	index = 0;
 
+	shash->tfm = fs_info->csum_shash;
+
 	bio_for_each_segment(bvec, bio, iter) {
 		if (!contig)
 			offset = page_offset(bvec.bv_page) + bvec.bv_offset;
@@ -460,8 +478,6 @@
 			BUG_ON(!ordered); /* Logic error */
 		}
 
-		data = kmap_atomic(bvec.bv_page);
-
 		nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info,
 						 bvec.bv_len + fs_info->sectorsize
 						 - 1);
@@ -471,16 +487,17 @@
 				offset < ordered->file_offset) {
 				unsigned long bytes_left;
 
-				kunmap_atomic(data);
 				sums->len = this_sum_bytes;
 				this_sum_bytes = 0;
-				btrfs_add_ordered_sum(inode, ordered, sums);
+				btrfs_add_ordered_sum(ordered, sums);
 				btrfs_put_ordered_extent(ordered);
 
 				bytes_left = bio->bi_iter.bi_size - total_bytes;
 
-				sums = kzalloc(btrfs_ordered_sum_size(fs_info, bytes_left),
-					       GFP_NOFS);
+				nofs_flag = memalloc_nofs_save();
+				sums = kvzalloc(btrfs_ordered_sum_size(fs_info,
+						      bytes_left), GFP_KERNEL);
+				memalloc_nofs_restore(nofs_flag);
 				BUG_ON(!sums); /* -ENOMEM */
 				sums->len = bytes_left;
 				ordered = btrfs_lookup_ordered_extent(inode,
@@ -489,28 +506,24 @@
 				sums->bytenr = ((u64)bio->bi_iter.bi_sector << 9)
 					+ total_bytes;
 				index = 0;
-
-				data = kmap_atomic(bvec.bv_page);
 			}
 
-			sums->sums[index] = ~(u32)0;
-			sums->sums[index]
-				= btrfs_csum_data(data + bvec.bv_offset
-						+ (i * fs_info->sectorsize),
-						sums->sums[index],
-						fs_info->sectorsize);
-			btrfs_csum_final(sums->sums[index],
-					(char *)(sums->sums + index));
-			index++;
+			crypto_shash_init(shash);
+			data = kmap_atomic(bvec.bv_page);
+			crypto_shash_update(shash, data + bvec.bv_offset
+					    + (i * fs_info->sectorsize),
+					    fs_info->sectorsize);
+			kunmap_atomic(data);
+			crypto_shash_final(shash, (char *)(sums->sums + index));
+			index += csum_size;
 			offset += fs_info->sectorsize;
 			this_sum_bytes += fs_info->sectorsize;
 			total_bytes += fs_info->sectorsize;
 		}
 
-		kunmap_atomic(data);
 	}
 	this_sum_bytes = 0;
-	btrfs_add_ordered_sum(inode, ordered, sums);
+	btrfs_add_ordered_sum(ordered, sums);
 	btrfs_put_ordered_extent(ordered);
 	return 0;
 }
@@ -551,7 +564,7 @@
 		 */
 		u32 new_size = (bytenr - key->offset) >> blocksize_bits;
 		new_size *= csum_size;
-		btrfs_truncate_item(fs_info, path, new_size, 1);
+		btrfs_truncate_item(path, new_size, 1);
 	} else if (key->offset >= bytenr && csum_end > end_byte &&
 		   end_byte > key->offset) {
 		/*
@@ -563,7 +576,7 @@
 		u32 new_size = (csum_end - end_byte) >> blocksize_bits;
 		new_size *= csum_size;
 
-		btrfs_truncate_item(fs_info, path, new_size, 0);
+		btrfs_truncate_item(path, new_size, 0);
 
 		key->offset = end_byte;
 		btrfs_set_item_key_safe(fs_info, path, key);
@@ -832,11 +845,11 @@
 		u32 diff;
 		u32 free_space;
 
-		if (btrfs_leaf_free_space(fs_info, leaf) <
+		if (btrfs_leaf_free_space(leaf) <
 				 sizeof(struct btrfs_item) + csum_size * 2)
 			goto insert;
 
-		free_space = btrfs_leaf_free_space(fs_info, leaf) -
+		free_space = btrfs_leaf_free_space(leaf) -
 					 sizeof(struct btrfs_item) - csum_size;
 		tmp = sums->len - total_bytes;
 		tmp >>= fs_info->sb->s_blocksize_bits;
@@ -852,7 +865,7 @@
 		diff /= csum_size;
 		diff *= csum_size;
 
-		btrfs_extend_item(fs_info, path, diff);
+		btrfs_extend_item(path, diff);
 		ret = 0;
 		goto csum;
 	}
@@ -898,9 +911,9 @@
 	write_extent_buffer(leaf, sums->sums + index, (unsigned long)item,
 			    ins_size);
 
+	index += ins_size;
 	ins_size /= csum_size;
 	total_bytes += ins_size * fs_info->sectorsize;
-	index += ins_size;
 
 	btrfs_mark_buffer_dirty(path->nodes[0]);
 	if (total_bytes < sums->len) {
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index ca4902c..435a502 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -26,6 +26,7 @@
 #include "volumes.h"
 #include "qgroup.h"
 #include "compression.h"
+#include "delalloc-space.h"
 
 static struct kmem_cache *btrfs_inode_defrag_cachep;
 /*
@@ -399,7 +400,7 @@
 	size_t copied = 0;
 	size_t total_copied = 0;
 	int pg = 0;
-	int offset = pos & (PAGE_SIZE - 1);
+	int offset = offset_in_page(pos);
 
 	while (write_bytes > 0) {
 		size_t count = min_t(size_t,
@@ -536,8 +537,8 @@
 	 * we can set things up properly
 	 */
 	clear_extent_bit(&BTRFS_I(inode)->io_tree, start_pos, end_of_last_block,
-			 EXTENT_DIRTY | EXTENT_DELALLOC |
-			 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0, cached);
+			 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
+			 0, 0, cached);
 
 	if (!btrfs_is_free_space_inode(BTRFS_I(inode))) {
 		if (start_pos >= isize &&
@@ -558,7 +559,7 @@
 	}
 
 	err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
-					extra_bits, cached, 0);
+					extra_bits, cached);
 	if (err)
 		return err;
 
@@ -754,6 +755,7 @@
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct extent_buffer *leaf;
 	struct btrfs_file_extent_item *fi;
+	struct btrfs_ref ref = { 0 };
 	struct btrfs_key key;
 	struct btrfs_key new_key;
 	u64 ino = btrfs_ino(BTRFS_I(inode));
@@ -909,11 +911,14 @@
 			btrfs_mark_buffer_dirty(leaf);
 
 			if (update_refs && disk_bytenr > 0) {
-				ret = btrfs_inc_extent_ref(trans, root,
-						disk_bytenr, num_bytes, 0,
+				btrfs_init_generic_ref(&ref,
+						BTRFS_ADD_DELAYED_REF,
+						disk_bytenr, num_bytes, 0);
+				btrfs_init_data_ref(&ref,
 						root->root_key.objectid,
 						new_key.objectid,
 						start - extent_offset);
+				ret = btrfs_inc_extent_ref(trans, &ref);
 				BUG_ON(ret); /* -ENOMEM */
 			}
 			key.offset = start;
@@ -993,11 +998,14 @@
 				extent_end = ALIGN(extent_end,
 						   fs_info->sectorsize);
 			} else if (update_refs && disk_bytenr > 0) {
-				ret = btrfs_free_extent(trans, root,
-						disk_bytenr, num_bytes, 0,
+				btrfs_init_generic_ref(&ref,
+						BTRFS_DROP_DELAYED_REF,
+						disk_bytenr, num_bytes, 0);
+				btrfs_init_data_ref(&ref,
 						root->root_key.objectid,
-						key.objectid, key.offset -
-						extent_offset);
+						key.objectid,
+						key.offset - extent_offset);
+				ret = btrfs_free_extent(trans, &ref);
 				BUG_ON(ret); /* -ENOMEM */
 				inode_sub_bytes(inode,
 						extent_end - key.offset);
@@ -1025,7 +1033,7 @@
 			continue;
 		}
 
-		BUG_ON(1);
+		BUG();
 	}
 
 	if (!ret && del_nr > 0) {
@@ -1050,7 +1058,7 @@
 	if (!ret && replace_extent && leafs_visited == 1 &&
 	    (path->locks[0] == BTRFS_WRITE_LOCK_BLOCKING ||
 	     path->locks[0] == BTRFS_WRITE_LOCK) &&
-	    btrfs_leaf_free_space(fs_info, leaf) >=
+	    btrfs_leaf_free_space(leaf) >=
 	    sizeof(struct btrfs_item) + extent_item_size) {
 
 		key.objectid = ino;
@@ -1142,6 +1150,7 @@
 	struct extent_buffer *leaf;
 	struct btrfs_path *path;
 	struct btrfs_file_extent_item *fi;
+	struct btrfs_ref ref = { 0 };
 	struct btrfs_key key;
 	struct btrfs_key new_key;
 	u64 bytenr;
@@ -1287,9 +1296,11 @@
 						extent_end - split);
 		btrfs_mark_buffer_dirty(leaf);
 
-		ret = btrfs_inc_extent_ref(trans, root, bytenr, num_bytes,
-					   0, root->root_key.objectid,
-					   ino, orig_offset);
+		btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, bytenr,
+				       num_bytes, 0);
+		btrfs_init_data_ref(&ref, root->root_key.objectid, ino,
+				    orig_offset);
+		ret = btrfs_inc_extent_ref(trans, &ref);
 		if (ret) {
 			btrfs_abort_transaction(trans, ret);
 			goto out;
@@ -1311,6 +1322,9 @@
 
 	other_start = end;
 	other_end = 0;
+	btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, bytenr,
+			       num_bytes, 0);
+	btrfs_init_data_ref(&ref, root->root_key.objectid, ino, orig_offset);
 	if (extent_mergeable(leaf, path->slots[0] + 1,
 			     ino, bytenr, orig_offset,
 			     &other_start, &other_end)) {
@@ -1321,9 +1335,7 @@
 		extent_end = other_end;
 		del_slot = path->slots[0] + 1;
 		del_nr++;
-		ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
-					0, root->root_key.objectid,
-					ino, orig_offset);
+		ret = btrfs_free_extent(trans, &ref);
 		if (ret) {
 			btrfs_abort_transaction(trans, ret);
 			goto out;
@@ -1341,9 +1353,7 @@
 		key.offset = other_start;
 		del_slot = path->slots[0];
 		del_nr++;
-		ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
-					0, root->root_key.objectid,
-					ino, orig_offset);
+		ret = btrfs_free_extent(trans, &ref);
 		if (ret) {
 			btrfs_abort_transaction(trans, ret);
 			goto out;
@@ -1541,30 +1551,20 @@
 {
 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
 	struct btrfs_root *root = inode->root;
-	struct btrfs_ordered_extent *ordered;
 	u64 lockstart, lockend;
 	u64 num_bytes;
 	int ret;
 
 	ret = btrfs_start_write_no_snapshotting(root);
 	if (!ret)
-		return -ENOSPC;
+		return -EAGAIN;
 
 	lockstart = round_down(pos, fs_info->sectorsize);
 	lockend = round_up(pos + *write_bytes,
 			   fs_info->sectorsize) - 1;
 
-	while (1) {
-		lock_extent(&inode->io_tree, lockstart, lockend);
-		ordered = btrfs_lookup_ordered_range(inode, lockstart,
-						     lockend - lockstart + 1);
-		if (!ordered) {
-			break;
-		}
-		unlock_extent(&inode->io_tree, lockstart, lockend);
-		btrfs_start_ordered_extent(&inode->vfs_inode, ordered, 1);
-		btrfs_put_ordered_extent(ordered);
-	}
+	btrfs_lock_and_flush_ordered_range(&inode->io_tree, inode, lockstart,
+					   lockend, NULL);
 
 	num_bytes = lockend - lockstart + 1;
 	ret = can_nocow_extent(&inode->vfs_inode, lockstart, &num_bytes,
@@ -1591,7 +1591,6 @@
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct page **pages = NULL;
-	struct extent_state *cached_state = NULL;
 	struct extent_changeset *data_reserved = NULL;
 	u64 release_bytes = 0;
 	u64 lockstart;
@@ -1611,7 +1610,8 @@
 		return -ENOMEM;
 
 	while (iov_iter_count(i) > 0) {
-		size_t offset = pos & (PAGE_SIZE - 1);
+		struct extent_state *cached_state = NULL;
+		size_t offset = offset_in_page(pos);
 		size_t sector_offset;
 		size_t write_bytes = min(iov_iter_count(i),
 					 nrptrs * (size_t)PAGE_SIZE -
@@ -1692,7 +1692,7 @@
 				    force_page_uptodate);
 		if (ret) {
 			btrfs_delalloc_release_extents(BTRFS_I(inode),
-						       reserve_bytes, true);
+						       reserve_bytes);
 			break;
 		}
 
@@ -1704,7 +1704,7 @@
 			if (extents_locked == -EAGAIN)
 				goto again;
 			btrfs_delalloc_release_extents(BTRFS_I(inode),
-						       reserve_bytes, true);
+						       reserve_bytes);
 			ret = extents_locked;
 			break;
 		}
@@ -1758,11 +1758,21 @@
 		if (copied > 0)
 			ret = btrfs_dirty_pages(inode, pages, dirty_pages,
 						pos, copied, &cached_state);
+
+		/*
+		 * If we have not locked the extent range, because the range's
+		 * start offset is >= i_size, we might still have a non-NULL
+		 * cached extent state, acquired while marking the extent range
+		 * as delalloc through btrfs_dirty_pages(). Therefore free any
+		 * possible cached extent state to avoid a memory leak.
+		 */
 		if (extents_locked)
 			unlock_extent_cached(&BTRFS_I(inode)->io_tree,
 					     lockstart, lockend, &cached_state);
-		btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes,
-					       true);
+		else
+			free_extent_state(cached_state);
+
+		btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes);
 		if (ret) {
 			btrfs_drop_pages(pages, num_pages);
 			break;
@@ -1882,10 +1892,10 @@
 	u64 start_pos;
 	u64 end_pos;
 	ssize_t num_written = 0;
-	bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host);
+	const bool sync = iocb->ki_flags & IOCB_DSYNC;
 	ssize_t err;
 	loff_t pos;
-	size_t count = iov_iter_count(from);
+	size_t count;
 	loff_t oldsize;
 	int clean_page = 0;
 
@@ -1906,6 +1916,7 @@
 	}
 
 	pos = iocb->ki_pos;
+	count = iov_iter_count(from);
 	if (iocb->ki_flags & IOCB_NOWAIT) {
 		/*
 		 * We will allocate space in case nodatacow is not set,
@@ -2005,7 +2016,7 @@
 	filp->private_data = NULL;
 
 	/*
-	 * ordered_data_close is set by settattr when we are about to truncate
+	 * ordered_data_close is set by setattr when we are about to truncate
 	 * a file from a non-zero size to a zero size.  This tries to
 	 * flush down new bytes that may have been written if the
 	 * application were using truncate to replace a file in place.
@@ -2056,13 +2067,7 @@
 	struct btrfs_trans_handle *trans;
 	struct btrfs_log_ctx ctx;
 	int ret = 0, err;
-	u64 len;
 
-	/*
-	 * The range length can be represented by u64, we have to do the typecasts
-	 * to avoid signed overflow if it's [0, LLONG_MAX] eg. from fsync()
-	 */
-	len = (u64)end - (u64)start + 1;
 	trace_btrfs_sync_file(file, datasync);
 
 	btrfs_init_log_ctx(&ctx, inode);
@@ -2089,6 +2094,19 @@
 	atomic_inc(&root->log_batch);
 
 	/*
+	 * If the inode needs a full sync, make sure we use a full range to
+	 * avoid log tree corruption, due to hole detection racing with ordered
+	 * extent completion for adjacent ranges, and assertion failures during
+	 * hole detection. Do this while holding the inode lock, to avoid races
+	 * with other tasks.
+	 */
+	if (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
+		     &BTRFS_I(inode)->runtime_flags)) {
+		start = 0;
+		end = LLONG_MAX;
+	}
+
+	/*
 	 * Before we acquired the inode's lock, someone may have dirtied more
 	 * pages in the target range. We need to make sure that writeback for
 	 * any such pages does not start while we are logging the inode, because
@@ -2114,9 +2132,12 @@
 
 	/*
 	 * We have to do this here to avoid the priority inversion of waiting on
-	 * IO of a lower priority task while holding a transaciton open.
+	 * IO of a lower priority task while holding a transaction open.
+	 *
+	 * Also, the range length can be represented by u64, we have to do the
+	 * typecasts to avoid signed overflow if it's [0, LLONG_MAX].
 	 */
-	ret = btrfs_wait_ordered_range(inode, start, len);
+	ret = btrfs_wait_ordered_range(inode, start, (u64)end - (u64)start + 1);
 	if (ret) {
 		up_write(&BTRFS_I(inode)->dio_sem);
 		inode_unlock(inode);
@@ -2154,7 +2175,7 @@
 	 * here we could get into a situation where we're waiting on IO to
 	 * happen that is blocked on a transaction trying to commit.  With start
 	 * we inc the extwriter counter, so we wait for all extwriters to exit
-	 * before we start blocking join'ers.  This comment is to keep somebody
+	 * before we start blocking joiners.  This comment is to keep somebody
 	 * from thinking they are super smart and changing this to
 	 * btrfs_join_transaction *cough*Josef*cough*.
 	 */
@@ -2165,7 +2186,6 @@
 		inode_unlock(inode);
 		goto out;
 	}
-	trans->sync = true;
 
 	ret = btrfs_log_dentry_safe(trans, dentry, start, end, &ctx);
 	if (ret < 0) {
@@ -2186,25 +2206,6 @@
 	up_write(&BTRFS_I(inode)->dio_sem);
 	inode_unlock(inode);
 
-	/*
-	 * If any of the ordered extents had an error, just return it to user
-	 * space, so that the application knows some writes didn't succeed and
-	 * can take proper action (retry for e.g.). Blindly committing the
-	 * transaction in this case, would fool userspace that everything was
-	 * successful. And we also want to make sure our log doesn't contain
-	 * file extent items pointing to extents that weren't fully written to -
-	 * just like in the non fast fsync path, where we check for the ordered
-	 * operation's error flag before writing to the log tree and return -EIO
-	 * if any of them had this flag set (btrfs_wait_ordered_range) -
-	 * therefore we need to check for errors in the ordered operations,
-	 * which are indicated by ctx.io_err.
-	 */
-	if (ctx.io_err) {
-		btrfs_end_transaction(trans);
-		ret = ctx.io_err;
-		goto out;
-	}
-
 	if (ret != BTRFS_NO_LOG_SYNC) {
 		if (!ret) {
 			ret = btrfs_sync_log(trans, root, &ctx);
@@ -2447,27 +2448,286 @@
 	return 0;
 }
 
+static int btrfs_insert_clone_extent(struct btrfs_trans_handle *trans,
+				     struct inode *inode,
+				     struct btrfs_path *path,
+				     struct btrfs_clone_extent_info *clone_info,
+				     const u64 clone_len)
+{
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	struct btrfs_root *root = BTRFS_I(inode)->root;
+	struct btrfs_file_extent_item *extent;
+	struct extent_buffer *leaf;
+	struct btrfs_key key;
+	int slot;
+	struct btrfs_ref ref = { 0 };
+	u64 ref_offset;
+	int ret;
+
+	if (clone_len == 0)
+		return 0;
+
+	if (clone_info->disk_offset == 0 &&
+	    btrfs_fs_incompat(fs_info, NO_HOLES))
+		return 0;
+
+	key.objectid = btrfs_ino(BTRFS_I(inode));
+	key.type = BTRFS_EXTENT_DATA_KEY;
+	key.offset = clone_info->file_offset;
+	ret = btrfs_insert_empty_item(trans, root, path, &key,
+				      clone_info->item_size);
+	if (ret)
+		return ret;
+	leaf = path->nodes[0];
+	slot = path->slots[0];
+	write_extent_buffer(leaf, clone_info->extent_buf,
+			    btrfs_item_ptr_offset(leaf, slot),
+			    clone_info->item_size);
+	extent = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
+	btrfs_set_file_extent_offset(leaf, extent, clone_info->data_offset);
+	btrfs_set_file_extent_num_bytes(leaf, extent, clone_len);
+	btrfs_mark_buffer_dirty(leaf);
+	btrfs_release_path(path);
+
+	/* If it's a hole, nothing more needs to be done. */
+	if (clone_info->disk_offset == 0)
+		return 0;
+
+	inode_add_bytes(inode, clone_len);
+	btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF,
+			       clone_info->disk_offset,
+			       clone_info->disk_len, 0);
+	ref_offset = clone_info->file_offset - clone_info->data_offset;
+	btrfs_init_data_ref(&ref, root->root_key.objectid,
+			    btrfs_ino(BTRFS_I(inode)), ref_offset);
+	ret = btrfs_inc_extent_ref(trans, &ref);
+
+	return ret;
+}
+
+/*
+ * The respective range must have been previously locked, as well as the inode.
+ * The end offset is inclusive (last byte of the range).
+ * @clone_info is NULL for fallocate's hole punching and non-NULL for extent
+ * cloning.
+ * When cloning, we don't want to end up in a state where we dropped extents
+ * without inserting a new one, so we must abort the transaction to avoid a
+ * corruption.
+ */
+int btrfs_punch_hole_range(struct inode *inode, struct btrfs_path *path,
+			   const u64 start, const u64 end,
+			   struct btrfs_clone_extent_info *clone_info,
+			   struct btrfs_trans_handle **trans_out)
+{
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	u64 min_size = btrfs_calc_insert_metadata_size(fs_info, 1);
+	u64 ino_size = round_up(inode->i_size, fs_info->sectorsize);
+	struct btrfs_root *root = BTRFS_I(inode)->root;
+	struct btrfs_trans_handle *trans = NULL;
+	struct btrfs_block_rsv *rsv;
+	unsigned int rsv_count;
+	u64 cur_offset;
+	u64 drop_end;
+	u64 len = end - start;
+	int ret = 0;
+
+	if (end <= start)
+		return -EINVAL;
+
+	rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
+	if (!rsv) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	rsv->size = btrfs_calc_insert_metadata_size(fs_info, 1);
+	rsv->failfast = 1;
+
+	/*
+	 * 1 - update the inode
+	 * 1 - removing the extents in the range
+	 * 1 - adding the hole extent if no_holes isn't set or if we are cloning
+	 *     an extent
+	 */
+	if (!btrfs_fs_incompat(fs_info, NO_HOLES) || clone_info)
+		rsv_count = 3;
+	else
+		rsv_count = 2;
+
+	trans = btrfs_start_transaction(root, rsv_count);
+	if (IS_ERR(trans)) {
+		ret = PTR_ERR(trans);
+		trans = NULL;
+		goto out_free;
+	}
+
+	ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
+				      min_size, false);
+	BUG_ON(ret);
+	trans->block_rsv = rsv;
+
+	cur_offset = start;
+	while (cur_offset < end) {
+		ret = __btrfs_drop_extents(trans, root, inode, path,
+					   cur_offset, end + 1, &drop_end,
+					   1, 0, 0, NULL);
+		if (ret != -ENOSPC) {
+			/*
+			 * When cloning we want to avoid transaction aborts when
+			 * nothing was done and we are attempting to clone parts
+			 * of inline extents, in such cases -EOPNOTSUPP is
+			 * returned by __btrfs_drop_extents() without having
+			 * changed anything in the file.
+			 */
+			if (clone_info && ret && ret != -EOPNOTSUPP)
+				btrfs_abort_transaction(trans, ret);
+			break;
+		}
+
+		trans->block_rsv = &fs_info->trans_block_rsv;
+
+		if (!clone_info && cur_offset < drop_end &&
+		    cur_offset < ino_size) {
+			ret = fill_holes(trans, BTRFS_I(inode), path,
+					cur_offset, drop_end);
+			if (ret) {
+				/*
+				 * If we failed then we didn't insert our hole
+				 * entries for the area we dropped, so now the
+				 * fs is corrupted, so we must abort the
+				 * transaction.
+				 */
+				btrfs_abort_transaction(trans, ret);
+				break;
+			}
+		}
+
+		if (clone_info) {
+			u64 clone_len = drop_end - cur_offset;
+
+			ret = btrfs_insert_clone_extent(trans, inode, path,
+							clone_info, clone_len);
+			if (ret) {
+				btrfs_abort_transaction(trans, ret);
+				break;
+			}
+			clone_info->data_len -= clone_len;
+			clone_info->data_offset += clone_len;
+			clone_info->file_offset += clone_len;
+		}
+
+		cur_offset = drop_end;
+
+		ret = btrfs_update_inode(trans, root, inode);
+		if (ret)
+			break;
+
+		btrfs_end_transaction(trans);
+		btrfs_btree_balance_dirty(fs_info);
+
+		trans = btrfs_start_transaction(root, rsv_count);
+		if (IS_ERR(trans)) {
+			ret = PTR_ERR(trans);
+			trans = NULL;
+			break;
+		}
+
+		ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
+					      rsv, min_size, false);
+		BUG_ON(ret);	/* shouldn't happen */
+		trans->block_rsv = rsv;
+
+		if (!clone_info) {
+			ret = find_first_non_hole(inode, &cur_offset, &len);
+			if (unlikely(ret < 0))
+				break;
+			if (ret && !len) {
+				ret = 0;
+				break;
+			}
+		}
+	}
+
+	/*
+	 * If we were cloning, force the next fsync to be a full one since we
+	 * we replaced (or just dropped in the case of cloning holes when
+	 * NO_HOLES is enabled) extents and extent maps.
+	 * This is for the sake of simplicity, and cloning into files larger
+	 * than 16Mb would force the full fsync any way (when
+	 * try_release_extent_mapping() is invoked during page cache truncation.
+	 */
+	if (clone_info)
+		set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
+			&BTRFS_I(inode)->runtime_flags);
+
+	if (ret)
+		goto out_trans;
+
+	trans->block_rsv = &fs_info->trans_block_rsv;
+	/*
+	 * If we are using the NO_HOLES feature we might have had already an
+	 * hole that overlaps a part of the region [lockstart, lockend] and
+	 * ends at (or beyond) lockend. Since we have no file extent items to
+	 * represent holes, drop_end can be less than lockend and so we must
+	 * make sure we have an extent map representing the existing hole (the
+	 * call to __btrfs_drop_extents() might have dropped the existing extent
+	 * map representing the existing hole), otherwise the fast fsync path
+	 * will not record the existence of the hole region
+	 * [existing_hole_start, lockend].
+	 */
+	if (drop_end <= end)
+		drop_end = end + 1;
+	/*
+	 * Don't insert file hole extent item if it's for a range beyond eof
+	 * (because it's useless) or if it represents a 0 bytes range (when
+	 * cur_offset == drop_end).
+	 */
+	if (!clone_info && cur_offset < ino_size && cur_offset < drop_end) {
+		ret = fill_holes(trans, BTRFS_I(inode), path,
+				cur_offset, drop_end);
+		if (ret) {
+			/* Same comment as above. */
+			btrfs_abort_transaction(trans, ret);
+			goto out_trans;
+		}
+	}
+	if (clone_info) {
+		ret = btrfs_insert_clone_extent(trans, inode, path, clone_info,
+						clone_info->data_len);
+		if (ret) {
+			btrfs_abort_transaction(trans, ret);
+			goto out_trans;
+		}
+	}
+
+out_trans:
+	if (!trans)
+		goto out_free;
+
+	trans->block_rsv = &fs_info->trans_block_rsv;
+	if (ret)
+		btrfs_end_transaction(trans);
+	else
+		*trans_out = trans;
+out_free:
+	btrfs_free_block_rsv(fs_info, rsv);
+out:
+	return ret;
+}
+
 static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct extent_state *cached_state = NULL;
 	struct btrfs_path *path;
-	struct btrfs_block_rsv *rsv;
-	struct btrfs_trans_handle *trans;
+	struct btrfs_trans_handle *trans = NULL;
 	u64 lockstart;
 	u64 lockend;
 	u64 tail_start;
 	u64 tail_len;
 	u64 orig_start = offset;
-	u64 cur_offset;
-	u64 min_size = btrfs_calc_trans_metadata_size(fs_info, 1);
-	u64 drop_end;
 	int ret = 0;
-	int err = 0;
-	unsigned int rsv_count;
 	bool same_block;
-	bool no_holes = btrfs_fs_incompat(fs_info, NO_HOLES);
 	u64 ino_size;
 	bool truncated_block = false;
 	bool updated_inode = false;
@@ -2565,10 +2825,8 @@
 
 	ret = btrfs_punch_hole_lock_range(inode, lockstart, lockend,
 					  &cached_state);
-	if (ret) {
-		inode_unlock(inode);
+	if (ret)
 		goto out_only_mutex;
-	}
 
 	path = btrfs_alloc_path();
 	if (!path) {
@@ -2576,145 +2834,24 @@
 		goto out;
 	}
 
-	rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
-	if (!rsv) {
-		ret = -ENOMEM;
-		goto out_free;
-	}
-	rsv->size = btrfs_calc_trans_metadata_size(fs_info, 1);
-	rsv->failfast = 1;
+	ret = btrfs_punch_hole_range(inode, path, lockstart, lockend, NULL,
+				     &trans);
+	btrfs_free_path(path);
+	if (ret)
+		goto out;
 
-	/*
-	 * 1 - update the inode
-	 * 1 - removing the extents in the range
-	 * 1 - adding the hole extent if no_holes isn't set
-	 */
-	rsv_count = no_holes ? 2 : 3;
-	trans = btrfs_start_transaction(root, rsv_count);
-	if (IS_ERR(trans)) {
-		err = PTR_ERR(trans);
-		goto out_free;
-	}
-
-	ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
-				      min_size, 0);
-	BUG_ON(ret);
-	trans->block_rsv = rsv;
-
-	cur_offset = lockstart;
-	len = lockend - cur_offset;
-	while (cur_offset < lockend) {
-		ret = __btrfs_drop_extents(trans, root, inode, path,
-					   cur_offset, lockend + 1,
-					   &drop_end, 1, 0, 0, NULL);
-		if (ret != -ENOSPC)
-			break;
-
-		trans->block_rsv = &fs_info->trans_block_rsv;
-
-		if (cur_offset < drop_end && cur_offset < ino_size) {
-			ret = fill_holes(trans, BTRFS_I(inode), path,
-					cur_offset, drop_end);
-			if (ret) {
-				/*
-				 * If we failed then we didn't insert our hole
-				 * entries for the area we dropped, so now the
-				 * fs is corrupted, so we must abort the
-				 * transaction.
-				 */
-				btrfs_abort_transaction(trans, ret);
-				err = ret;
-				break;
-			}
-		}
-
-		cur_offset = drop_end;
-
-		ret = btrfs_update_inode(trans, root, inode);
-		if (ret) {
-			err = ret;
-			break;
-		}
-
-		btrfs_end_transaction(trans);
-		btrfs_btree_balance_dirty(fs_info);
-
-		trans = btrfs_start_transaction(root, rsv_count);
-		if (IS_ERR(trans)) {
-			ret = PTR_ERR(trans);
-			trans = NULL;
-			break;
-		}
-
-		ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
-					      rsv, min_size, 0);
-		BUG_ON(ret);	/* shouldn't happen */
-		trans->block_rsv = rsv;
-
-		ret = find_first_non_hole(inode, &cur_offset, &len);
-		if (unlikely(ret < 0))
-			break;
-		if (ret && !len) {
-			ret = 0;
-			break;
-		}
-	}
-
-	if (ret) {
-		err = ret;
-		goto out_trans;
-	}
-
-	trans->block_rsv = &fs_info->trans_block_rsv;
-	/*
-	 * If we are using the NO_HOLES feature we might have had already an
-	 * hole that overlaps a part of the region [lockstart, lockend] and
-	 * ends at (or beyond) lockend. Since we have no file extent items to
-	 * represent holes, drop_end can be less than lockend and so we must
-	 * make sure we have an extent map representing the existing hole (the
-	 * call to __btrfs_drop_extents() might have dropped the existing extent
-	 * map representing the existing hole), otherwise the fast fsync path
-	 * will not record the existence of the hole region
-	 * [existing_hole_start, lockend].
-	 */
-	if (drop_end <= lockend)
-		drop_end = lockend + 1;
-	/*
-	 * Don't insert file hole extent item if it's for a range beyond eof
-	 * (because it's useless) or if it represents a 0 bytes range (when
-	 * cur_offset == drop_end).
-	 */
-	if (cur_offset < ino_size && cur_offset < drop_end) {
-		ret = fill_holes(trans, BTRFS_I(inode), path,
-				cur_offset, drop_end);
-		if (ret) {
-			/* Same comment as above. */
-			btrfs_abort_transaction(trans, ret);
-			err = ret;
-			goto out_trans;
-		}
-	}
-
-out_trans:
-	if (!trans)
-		goto out_free;
-
+	ASSERT(trans != NULL);
 	inode_inc_iversion(inode);
 	inode->i_mtime = inode->i_ctime = current_time(inode);
-
-	trans->block_rsv = &fs_info->trans_block_rsv;
 	ret = btrfs_update_inode(trans, root, inode);
 	updated_inode = true;
 	btrfs_end_transaction(trans);
 	btrfs_btree_balance_dirty(fs_info);
-out_free:
-	btrfs_free_path(path);
-	btrfs_free_block_rsv(fs_info, rsv);
 out:
 	unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
 			     &cached_state);
 out_only_mutex:
-	if (!updated_inode && truncated_block && !ret && !err) {
+	if (!updated_inode && truncated_block && !ret) {
 		/*
 		 * If we only end up zeroing part of a page, we still need to
 		 * update the inode item, so that all the time fields are
@@ -2722,18 +2859,25 @@
 		 * for detecting, at fsync time, if the inode isn't yet in the
 		 * log tree or it's there but not up to date.
 		 */
+		struct timespec64 now = current_time(inode);
+
+		inode_inc_iversion(inode);
+		inode->i_mtime = now;
+		inode->i_ctime = now;
 		trans = btrfs_start_transaction(root, 1);
 		if (IS_ERR(trans)) {
-			err = PTR_ERR(trans);
+			ret = PTR_ERR(trans);
 		} else {
-			err = btrfs_update_inode(trans, root, inode);
-			ret = btrfs_end_transaction(trans);
+			int ret2;
+
+			ret = btrfs_update_inode(trans, root, inode);
+			ret2 = btrfs_end_transaction(trans);
+			if (!ret)
+				ret = ret2;
 		}
 	}
 	inode_unlock(inode);
-	if (ret && !err)
-		err = ret;
-	return err;
+	return ret;
 }
 
 /* Helper structure to record which range is already reserved */
@@ -2802,9 +2946,9 @@
 }
 
 enum {
-	RANGE_BOUNDARY_WRITTEN_EXTENT = 0,
-	RANGE_BOUNDARY_PREALLOC_EXTENT = 1,
-	RANGE_BOUNDARY_HOLE = 2,
+	RANGE_BOUNDARY_WRITTEN_EXTENT,
+	RANGE_BOUNDARY_PREALLOC_EXTENT,
+	RANGE_BOUNDARY_HOLE,
 };
 
 static int btrfs_zero_range_check_range_boundary(struct inode *inode,
@@ -3151,6 +3295,7 @@
 			ret = btrfs_qgroup_reserve_data(inode, &data_reserved,
 					cur_offset, last_byte - cur_offset);
 			if (ret < 0) {
+				cur_offset = last_byte;
 				free_extent_map(em);
 				break;
 			}
@@ -3200,7 +3345,7 @@
 	/* Let go of our reservation. */
 	if (ret != 0 && !(mode & FALLOC_FL_ZERO_RANGE))
 		btrfs_free_reserved_data_space(inode, data_reserved,
-				alloc_start, alloc_end - cur_offset);
+				cur_offset, alloc_end - cur_offset);
 	extent_changeset_free(data_reserved);
 	return ret;
 }
@@ -3237,8 +3382,7 @@
 			 &cached_state);
 
 	while (start < inode->i_size) {
-		em = btrfs_get_extent_fiemap(BTRFS_I(inode), NULL, 0,
-				start, len, 0);
+		em = btrfs_get_extent_fiemap(BTRFS_I(inode), start, len);
 		if (IS_ERR(em)) {
 			ret = PTR_ERR(em);
 			em = NULL;
@@ -3322,8 +3466,7 @@
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= btrfs_compat_ioctl,
 #endif
-	.clone_file_range = btrfs_clone_file_range,
-	.dedupe_file_range = btrfs_dedupe_file_range,
+	.remap_file_range = btrfs_remap_file_range,
 };
 
 void __cold btrfs_auto_defrag_exit(void)
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 8ecf8c0..d54dcd0 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -18,6 +18,9 @@
 #include "extent_io.h"
 #include "inode-map.h"
 #include "volumes.h"
+#include "space-info.h"
+#include "delalloc-space.h"
+#include "block-group.h"
 
 #define BITS_PER_BITMAP		(PAGE_SIZE * 8UL)
 #define MAX_CACHE_BYTES_PER_GIG	SZ_32K
@@ -75,7 +78,8 @@
 	 * sure NOFS is set to keep us from deadlocking.
 	 */
 	nofs_flag = memalloc_nofs_save();
-	inode = btrfs_iget(fs_info->sb, &location, root, NULL);
+	inode = btrfs_iget_path(fs_info->sb, &location, root, NULL, path);
+	btrfs_release_path(path);
 	memalloc_nofs_restore(nofs_flag);
 	if (IS_ERR(inode))
 		return inode;
@@ -87,10 +91,11 @@
 	return inode;
 }
 
-struct inode *lookup_free_space_inode(struct btrfs_fs_info *fs_info,
-				      struct btrfs_block_group_cache
-				      *block_group, struct btrfs_path *path)
+struct inode *lookup_free_space_inode(
+		struct btrfs_block_group_cache *block_group,
+		struct btrfs_path *path)
 {
+	struct btrfs_fs_info *fs_info = block_group->fs_info;
 	struct inode *inode = NULL;
 	u32 flags = BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
 
@@ -184,20 +189,19 @@
 	return 0;
 }
 
-int create_free_space_inode(struct btrfs_fs_info *fs_info,
-			    struct btrfs_trans_handle *trans,
+int create_free_space_inode(struct btrfs_trans_handle *trans,
 			    struct btrfs_block_group_cache *block_group,
 			    struct btrfs_path *path)
 {
 	int ret;
 	u64 ino;
 
-	ret = btrfs_find_free_objectid(fs_info->tree_root, &ino);
+	ret = btrfs_find_free_objectid(trans->fs_info->tree_root, &ino);
 	if (ret < 0)
 		return ret;
 
-	return __create_free_space_inode(fs_info->tree_root, trans, path, ino,
-					 block_group->key.objectid);
+	return __create_free_space_inode(trans->fs_info->tree_root, trans, path,
+					 ino, block_group->key.objectid);
 }
 
 int btrfs_check_trunc_cache_free_space(struct btrfs_fs_info *fs_info,
@@ -207,8 +211,8 @@
 	int ret;
 
 	/* 1 for slack space, 1 for updating the inode */
-	needed_bytes = btrfs_calc_trunc_metadata_size(fs_info, 1) +
-		btrfs_calc_trans_metadata_size(fs_info, 1);
+	needed_bytes = btrfs_calc_insert_metadata_size(fs_info, 1) +
+		btrfs_calc_metadata_size(fs_info, 1);
 
 	spin_lock(&rsv->lock);
 	if (rsv->reserved < needed_bytes)
@@ -464,9 +468,8 @@
 	if (index == 0)
 		offset = sizeof(u32) * io_ctl->num_pages;
 
-	crc = btrfs_csum_data(io_ctl->orig + offset, crc,
-			      PAGE_SIZE - offset);
-	btrfs_csum_final(crc, (u8 *)&crc);
+	crc = btrfs_crc32c(crc, io_ctl->orig + offset, PAGE_SIZE - offset);
+	btrfs_crc32c_final(crc, (u8 *)&crc);
 	io_ctl_unmap_page(io_ctl);
 	tmp = page_address(io_ctl->pages[0]);
 	tmp += index;
@@ -492,9 +495,8 @@
 	val = *tmp;
 
 	io_ctl_map_page(io_ctl, 0);
-	crc = btrfs_csum_data(io_ctl->orig + offset, crc,
-			      PAGE_SIZE - offset);
-	btrfs_csum_final(crc, (u8 *)&crc);
+	crc = btrfs_crc32c(crc, io_ctl->orig + offset, PAGE_SIZE - offset);
+	btrfs_crc32c_final(crc, (u8 *)&crc);
 	if (val != crc) {
 		btrfs_err_rl(io_ctl->fs_info,
 			"csum mismatch on free space cache");
@@ -763,7 +765,8 @@
 		} else {
 			ASSERT(num_bitmaps);
 			num_bitmaps--;
-			e->bitmap = kzalloc(PAGE_SIZE, GFP_NOFS);
+			e->bitmap = kmem_cache_zalloc(
+					btrfs_free_space_bitmap_cachep, GFP_NOFS);
 			if (!e->bitmap) {
 				kmem_cache_free(
 					btrfs_free_space_cachep, e);
@@ -811,9 +814,9 @@
 	goto out;
 }
 
-int load_free_space_cache(struct btrfs_fs_info *fs_info,
-			  struct btrfs_block_group_cache *block_group)
+int load_free_space_cache(struct btrfs_block_group_cache *block_group)
 {
+	struct btrfs_fs_info *fs_info = block_group->fs_info;
 	struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
 	struct inode *inode;
 	struct btrfs_path *path;
@@ -838,7 +841,26 @@
 	path->search_commit_root = 1;
 	path->skip_locking = 1;
 
-	inode = lookup_free_space_inode(fs_info, block_group, path);
+	/*
+	 * We must pass a path with search_commit_root set to btrfs_iget in
+	 * order to avoid a deadlock when allocating extents for the tree root.
+	 *
+	 * When we are COWing an extent buffer from the tree root, when looking
+	 * for a free extent, at extent-tree.c:find_free_extent(), we can find
+	 * block group without its free space cache loaded. When we find one
+	 * we must load its space cache which requires reading its free space
+	 * cache's inode item from the root tree. If this inode item is located
+	 * in the same leaf that we started COWing before, then we end up in
+	 * deadlock on the extent buffer (trying to read lock it when we
+	 * previously write locked it).
+	 *
+	 * It's safe to read the inode item using the commit root because
+	 * block groups, once loaded, stay in memory forever (until they are
+	 * removed) as well as their space caches once loaded. New block groups
+	 * once created get their ->cached field set to BTRFS_CACHE_FINISHED so
+	 * we will never try to read their inode item while the fs is mounted.
+	 */
+	inode = lookup_free_space_inode(block_group, path);
 	if (IS_ERR(inode)) {
 		btrfs_free_path(path);
 		return 0;
@@ -984,7 +1006,7 @@
 	ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
 	if (ret < 0) {
 		clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
-				 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL);
+				 EXTENT_DELALLOC, 0, 0, NULL);
 		goto fail;
 	}
 	leaf = path->nodes[0];
@@ -996,9 +1018,8 @@
 		if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID ||
 		    found_key.offset != offset) {
 			clear_extent_bit(&BTRFS_I(inode)->io_tree, 0,
-					 inode->i_size - 1,
-					 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0,
-					 NULL);
+					 inode->i_size - 1, EXTENT_DELALLOC, 0,
+					 0, NULL);
 			btrfs_release_path(path);
 			goto fail;
 		}
@@ -1019,8 +1040,7 @@
 	return -1;
 }
 
-static noinline_for_stack int
-write_pinned_extent_entries(struct btrfs_fs_info *fs_info,
+static noinline_for_stack int write_pinned_extent_entries(
 			    struct btrfs_block_group_cache *block_group,
 			    struct btrfs_io_ctl *io_ctl,
 			    int *entries)
@@ -1039,7 +1059,7 @@
 	 * We shouldn't have switched the pinned extents yet so this is the
 	 * right one
 	 */
-	unpin = fs_info->pinned_extents;
+	unpin = block_group->fs_info->pinned_extents;
 
 	start = block_group->key.objectid;
 
@@ -1095,7 +1115,7 @@
 	ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
 	if (ret)
 		clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
-				 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL);
+				 EXTENT_DELALLOC, 0, 0, NULL);
 
 	return ret;
 }
@@ -1215,7 +1235,6 @@
 				   struct btrfs_io_ctl *io_ctl,
 				   struct btrfs_trans_handle *trans)
 {
-	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct extent_state *cached_state = NULL;
 	LIST_HEAD(bitmap_list);
 	int entries = 0;
@@ -1273,8 +1292,7 @@
 	 * If this changes while we are working we'll get added back to
 	 * the dirty list and redo it.  No locking needed
 	 */
-	ret = write_pinned_extent_entries(fs_info, block_group,
-					  io_ctl, &entries);
+	ret = write_pinned_extent_entries(block_group, io_ctl, &entries);
 	if (ret)
 		goto out_nospc_locked;
 
@@ -1350,11 +1368,11 @@
 	goto out;
 }
 
-int btrfs_write_out_cache(struct btrfs_fs_info *fs_info,
-			  struct btrfs_trans_handle *trans,
+int btrfs_write_out_cache(struct btrfs_trans_handle *trans,
 			  struct btrfs_block_group_cache *block_group,
 			  struct btrfs_path *path)
 {
+	struct btrfs_fs_info *fs_info = trans->fs_info;
 	struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
 	struct inode *inode;
 	int ret = 0;
@@ -1366,7 +1384,7 @@
 	}
 	spin_unlock(&block_group->lock);
 
-	inode = lookup_free_space_inode(fs_info, block_group, path);
+	inode = lookup_free_space_inode(block_group, path);
 	if (IS_ERR(inode))
 		return 0;
 
@@ -1864,7 +1882,7 @@
 			struct btrfs_free_space *bitmap_info)
 {
 	unlink_free_space(ctl, bitmap_info);
-	kfree(bitmap_info->bitmap);
+	kmem_cache_free(btrfs_free_space_bitmap_cachep, bitmap_info->bitmap);
 	kmem_cache_free(btrfs_free_space_cachep, bitmap_info);
 	ctl->total_bitmaps--;
 	ctl->op->recalc_thresholds(ctl);
@@ -2118,7 +2136,8 @@
 		}
 
 		/* allocate the bitmap */
-		info->bitmap = kzalloc(PAGE_SIZE, GFP_NOFS);
+		info->bitmap = kmem_cache_zalloc(btrfs_free_space_bitmap_cachep,
+						 GFP_NOFS);
 		spin_lock(&ctl->tree_lock);
 		if (!info->bitmap) {
 			ret = -ENOMEM;
@@ -2130,7 +2149,8 @@
 out:
 	if (info) {
 		if (info->bitmap)
-			kfree(info->bitmap);
+			kmem_cache_free(btrfs_free_space_bitmap_cachep,
+					info->bitmap);
 		kmem_cache_free(btrfs_free_space_cachep, info);
 	}
 
@@ -2360,6 +2380,14 @@
 	return ret;
 }
 
+int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
+			 u64 bytenr, u64 size)
+{
+	return __btrfs_add_free_space(block_group->fs_info,
+				      block_group->free_space_ctl,
+				      bytenr, size);
+}
+
 int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
 			    u64 offset, u64 bytes)
 {
@@ -2786,7 +2814,8 @@
 	if (entry->bytes == 0) {
 		ctl->free_extents--;
 		if (entry->bitmap) {
-			kfree(entry->bitmap);
+			kmem_cache_free(btrfs_free_space_bitmap_cachep,
+					entry->bitmap);
 			ctl->total_bitmaps--;
 			ctl->op->recalc_thresholds(ctl);
 		}
@@ -3021,11 +3050,11 @@
  * returns zero and sets up cluster if things worked out, otherwise
  * it returns -enospc
  */
-int btrfs_find_space_cluster(struct btrfs_fs_info *fs_info,
-			     struct btrfs_block_group_cache *block_group,
+int btrfs_find_space_cluster(struct btrfs_block_group_cache *block_group,
 			     struct btrfs_free_cluster *cluster,
 			     u64 offset, u64 bytes, u64 empty_size)
 {
+	struct btrfs_fs_info *fs_info = block_group->fs_info;
 	struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
 	struct btrfs_free_space *entry, *tmp;
 	LIST_HEAD(bitmaps);
@@ -3150,8 +3179,8 @@
 			space_info->bytes_readonly += reserved_bytes;
 		block_group->reserved -= reserved_bytes;
 		space_info->bytes_reserved -= reserved_bytes;
-		spin_unlock(&space_info->lock);
 		spin_unlock(&block_group->lock);
+		spin_unlock(&space_info->lock);
 	}
 
 	return ret;
@@ -3342,15 +3371,11 @@
 
 	if (cleanup) {
 		mutex_lock(&fs_info->chunk_mutex);
-		em_tree = &fs_info->mapping_tree.map_tree;
+		em_tree = &fs_info->mapping_tree;
 		write_lock(&em_tree->lock);
 		em = lookup_extent_mapping(em_tree, block_group->key.objectid,
 					   1);
 		BUG_ON(!em); /* logic error, can't happen */
-		/*
-		 * remove_extent_mapping() will delete us from the pinned_chunks
-		 * list, which is protected by the chunk mutex.
-		 */
 		remove_extent_mapping(em_tree, em);
 		write_unlock(&em_tree->lock);
 		mutex_unlock(&fs_info->chunk_mutex);
@@ -3594,7 +3619,7 @@
 	}
 
 	if (!map) {
-		map = kzalloc(PAGE_SIZE, GFP_NOFS);
+		map = kmem_cache_zalloc(btrfs_free_space_bitmap_cachep, GFP_NOFS);
 		if (!map) {
 			kmem_cache_free(btrfs_free_space_cachep, info);
 			return -ENOMEM;
@@ -3624,7 +3649,7 @@
 	if (info)
 		kmem_cache_free(btrfs_free_space_cachep, info);
 	if (map)
-		kfree(map);
+		kmem_cache_free(btrfs_free_space_bitmap_cachep, map);
 	return 0;
 }
 
diff --git a/fs/btrfs/free-space-cache.h b/fs/btrfs/free-space-cache.h
index 15e30b9..39c32c8 100644
--- a/fs/btrfs/free-space-cache.h
+++ b/fs/btrfs/free-space-cache.h
@@ -36,13 +36,24 @@
 			   struct btrfs_free_space *info);
 };
 
-struct btrfs_io_ctl;
+struct btrfs_io_ctl {
+	void *cur, *orig;
+	struct page *page;
+	struct page **pages;
+	struct btrfs_fs_info *fs_info;
+	struct inode *inode;
+	unsigned long size;
+	int index;
+	int num_pages;
+	int entries;
+	int bitmaps;
+	unsigned check_crcs:1;
+};
 
-struct inode *lookup_free_space_inode(struct btrfs_fs_info *fs_info,
-				      struct btrfs_block_group_cache
-				      *block_group, struct btrfs_path *path);
-int create_free_space_inode(struct btrfs_fs_info *fs_info,
-			    struct btrfs_trans_handle *trans,
+struct inode *lookup_free_space_inode(
+		struct btrfs_block_group_cache *block_group,
+		struct btrfs_path *path);
+int create_free_space_inode(struct btrfs_trans_handle *trans,
 			    struct btrfs_block_group_cache *block_group,
 			    struct btrfs_path *path);
 
@@ -51,13 +62,11 @@
 int btrfs_truncate_free_space_cache(struct btrfs_trans_handle *trans,
 				    struct btrfs_block_group_cache *block_group,
 				    struct inode *inode);
-int load_free_space_cache(struct btrfs_fs_info *fs_info,
-			  struct btrfs_block_group_cache *block_group);
+int load_free_space_cache(struct btrfs_block_group_cache *block_group);
 int btrfs_wait_cache_io(struct btrfs_trans_handle *trans,
 			struct btrfs_block_group_cache *block_group,
 			struct btrfs_path *path);
-int btrfs_write_out_cache(struct btrfs_fs_info *fs_info,
-			  struct btrfs_trans_handle *trans,
+int btrfs_write_out_cache(struct btrfs_trans_handle *trans,
 			  struct btrfs_block_group_cache *block_group,
 			  struct btrfs_path *path);
 struct inode *lookup_free_ino_inode(struct btrfs_root *root,
@@ -76,14 +85,8 @@
 int __btrfs_add_free_space(struct btrfs_fs_info *fs_info,
 			   struct btrfs_free_space_ctl *ctl,
 			   u64 bytenr, u64 size);
-static inline int
-btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
-		     u64 bytenr, u64 size)
-{
-	return __btrfs_add_free_space(block_group->fs_info,
-				      block_group->free_space_ctl,
-				      bytenr, size);
-}
+int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
+			 u64 bytenr, u64 size);
 int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
 			    u64 bytenr, u64 size);
 void __btrfs_remove_free_space_cache(struct btrfs_free_space_ctl *ctl);
@@ -95,8 +98,7 @@
 u64 btrfs_find_ino_for_alloc(struct btrfs_root *fs_root);
 void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group,
 			   u64 bytes);
-int btrfs_find_space_cluster(struct btrfs_fs_info *fs_info,
-			     struct btrfs_block_group_cache *block_group,
+int btrfs_find_space_cluster(struct btrfs_block_group_cache *block_group,
 			     struct btrfs_free_cluster *cluster,
 			     u64 offset, u64 bytes, u64 empty_size);
 void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster);
diff --git a/fs/btrfs/free-space-tree.c b/fs/btrfs/free-space-tree.c
index d673659..48a03f5 100644
--- a/fs/btrfs/free-space-tree.c
+++ b/fs/btrfs/free-space-tree.c
@@ -10,6 +10,7 @@
 #include "locking.h"
 #include "free-space-tree.h"
 #include "transaction.h"
+#include "block-group.h"
 
 static int __add_block_group_free_space(struct btrfs_trans_handle *trans,
 					struct btrfs_block_group_cache *block_group,
@@ -74,12 +75,13 @@
 	return ret;
 }
 
-struct btrfs_free_space_info *
-search_free_space_info(struct btrfs_trans_handle *trans,
-		       struct btrfs_fs_info *fs_info,
-		       struct btrfs_block_group_cache *block_group,
-		       struct btrfs_path *path, int cow)
+EXPORT_FOR_TESTS
+struct btrfs_free_space_info *search_free_space_info(
+		struct btrfs_trans_handle *trans,
+		struct btrfs_block_group_cache *block_group,
+		struct btrfs_path *path, int cow)
 {
+	struct btrfs_fs_info *fs_info = block_group->fs_info;
 	struct btrfs_root *root = fs_info->free_space_root;
 	struct btrfs_key key;
 	int ret;
@@ -176,6 +178,7 @@
 	}
 }
 
+EXPORT_FOR_TESTS
 int convert_free_space_to_bitmaps(struct btrfs_trans_handle *trans,
 				  struct btrfs_block_group_cache *block_group,
 				  struct btrfs_path *path)
@@ -252,7 +255,7 @@
 		btrfs_release_path(path);
 	}
 
-	info = search_free_space_info(trans, fs_info, block_group, path, 1);
+	info = search_free_space_info(trans, block_group, path, 1);
 	if (IS_ERR(info)) {
 		ret = PTR_ERR(info);
 		goto out;
@@ -315,6 +318,7 @@
 	return ret;
 }
 
+EXPORT_FOR_TESTS
 int convert_free_space_to_extents(struct btrfs_trans_handle *trans,
 				  struct btrfs_block_group_cache *block_group,
 				  struct btrfs_path *path)
@@ -396,7 +400,7 @@
 		btrfs_release_path(path);
 	}
 
-	info = search_free_space_info(trans, fs_info, block_group, path, 1);
+	info = search_free_space_info(trans, block_group, path, 1);
 	if (IS_ERR(info)) {
 		ret = PTR_ERR(info);
 		goto out;
@@ -461,8 +465,7 @@
 	if (new_extents == 0)
 		return 0;
 
-	info = search_free_space_info(trans, trans->fs_info, block_group, path,
-				      1);
+	info = search_free_space_info(trans, block_group, path, 1);
 	if (IS_ERR(info)) {
 		ret = PTR_ERR(info);
 		goto out;
@@ -487,6 +490,7 @@
 	return ret;
 }
 
+EXPORT_FOR_TESTS
 int free_space_test_bit(struct btrfs_block_group_cache *block_group,
 			struct btrfs_path *path, u64 offset)
 {
@@ -775,6 +779,7 @@
 	return ret;
 }
 
+EXPORT_FOR_TESTS
 int __remove_from_free_space_tree(struct btrfs_trans_handle *trans,
 				  struct btrfs_block_group_cache *block_group,
 				  struct btrfs_path *path, u64 start, u64 size)
@@ -789,8 +794,7 @@
 			return ret;
 	}
 
-	info = search_free_space_info(NULL, trans->fs_info, block_group, path,
-				      0);
+	info = search_free_space_info(NULL, block_group, path, 0);
 	if (IS_ERR(info))
 		return PTR_ERR(info);
 	flags = btrfs_free_space_flags(path->nodes[0], info);
@@ -968,11 +972,11 @@
 	return ret;
 }
 
+EXPORT_FOR_TESTS
 int __add_to_free_space_tree(struct btrfs_trans_handle *trans,
 			     struct btrfs_block_group_cache *block_group,
 			     struct btrfs_path *path, u64 start, u64 size)
 {
-	struct btrfs_fs_info *fs_info = trans->fs_info;
 	struct btrfs_free_space_info *info;
 	u32 flags;
 	int ret;
@@ -983,7 +987,7 @@
 			return ret;
 	}
 
-	info = search_free_space_info(NULL, fs_info, block_group, path, 0);
+	info = search_free_space_info(NULL, block_group, path, 0);
 	if (IS_ERR(info))
 		return PTR_ERR(info);
 	flags = btrfs_free_space_flags(path->nodes[0], info);
@@ -1145,7 +1149,7 @@
 		return PTR_ERR(trans);
 
 	set_bit(BTRFS_FS_CREATING_FREE_SPACE_TREE, &fs_info->flags);
-	free_space_root = btrfs_create_tree(trans, fs_info,
+	free_space_root = btrfs_create_tree(trans,
 					    BTRFS_FREE_SPACE_TREE_OBJECTID);
 	if (IS_ERR(free_space_root)) {
 		ret = PTR_ERR(free_space_root);
@@ -1243,7 +1247,7 @@
 	list_del(&free_space_root->dirty_list);
 
 	btrfs_tree_lock(free_space_root->node);
-	clean_tree_block(fs_info, free_space_root->node);
+	btrfs_clean_tree_block(free_space_root->node);
 	btrfs_tree_unlock(free_space_root->node);
 	btrfs_free_tree_block(trans, free_space_root, free_space_root->node,
 			      0, 1);
@@ -1529,14 +1533,12 @@
 int load_free_space_tree(struct btrfs_caching_control *caching_ctl)
 {
 	struct btrfs_block_group_cache *block_group;
-	struct btrfs_fs_info *fs_info;
 	struct btrfs_free_space_info *info;
 	struct btrfs_path *path;
 	u32 extent_count, flags;
 	int ret;
 
 	block_group = caching_ctl->block_group;
-	fs_info = block_group->fs_info;
 
 	path = btrfs_alloc_path();
 	if (!path)
@@ -1550,7 +1552,7 @@
 	path->search_commit_root = 1;
 	path->reada = READA_FORWARD;
 
-	info = search_free_space_info(NULL, fs_info, block_group, path, 0);
+	info = search_free_space_info(NULL, block_group, path, 0);
 	if (IS_ERR(info)) {
 		ret = PTR_ERR(info);
 		goto out;
diff --git a/fs/btrfs/free-space-tree.h b/fs/btrfs/free-space-tree.h
index 3133651..360d50e 100644
--- a/fs/btrfs/free-space-tree.h
+++ b/fs/btrfs/free-space-tree.h
@@ -6,6 +6,8 @@
 #ifndef BTRFS_FREE_SPACE_TREE_H
 #define BTRFS_FREE_SPACE_TREE_H
 
+struct btrfs_caching_control;
+
 /*
  * The default size for new free space bitmap items. The last bitmap in a block
  * group may be truncated, and none of the free space tree code assumes that
@@ -30,7 +32,6 @@
 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 struct btrfs_free_space_info *
 search_free_space_info(struct btrfs_trans_handle *trans,
-		       struct btrfs_fs_info *fs_info,
 		       struct btrfs_block_group_cache *block_group,
 		       struct btrfs_path *path, int cow);
 int __add_to_free_space_tree(struct btrfs_trans_handle *trans,
diff --git a/fs/btrfs/inode-item.c b/fs/btrfs/inode-item.c
index a8956a3..6687018 100644
--- a/fs/btrfs/inode-item.c
+++ b/fs/btrfs/inode-item.c
@@ -8,9 +8,9 @@
 #include "transaction.h"
 #include "print-tree.h"
 
-int btrfs_find_name_in_backref(struct extent_buffer *leaf, int slot,
-			       const char *name,
-			       int name_len, struct btrfs_inode_ref **ref_ret)
+struct btrfs_inode_ref *btrfs_find_name_in_backref(struct extent_buffer *leaf,
+						   int slot, const char *name,
+						   int name_len)
 {
 	struct btrfs_inode_ref *ref;
 	unsigned long ptr;
@@ -28,19 +28,15 @@
 		cur_offset += len + sizeof(*ref);
 		if (len != name_len)
 			continue;
-		if (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0) {
-			if (ref_ret)
-				*ref_ret = ref;
-			return 1;
-		}
+		if (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)
+			return ref;
 	}
-	return 0;
+	return NULL;
 }
 
-int btrfs_find_name_in_ext_backref(struct extent_buffer *leaf, int slot,
-				   u64 ref_objectid,
-				   const char *name, int name_len,
-				   struct btrfs_inode_extref **extref_ret)
+struct btrfs_inode_extref *btrfs_find_name_in_ext_backref(
+		struct extent_buffer *leaf, int slot, u64 ref_objectid,
+		const char *name, int name_len)
 {
 	struct btrfs_inode_extref *extref;
 	unsigned long ptr;
@@ -65,15 +61,12 @@
 
 		if (ref_name_len == name_len &&
 		    btrfs_inode_extref_parent(leaf, extref) == ref_objectid &&
-		    (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)) {
-			if (extref_ret)
-				*extref_ret = extref;
-			return 1;
-		}
+		    (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0))
+			return extref;
 
 		cur_offset += ref_name_len + sizeof(*extref);
 	}
-	return 0;
+	return NULL;
 }
 
 /* Returns NULL if no extref found */
@@ -87,7 +80,6 @@
 {
 	int ret;
 	struct btrfs_key key;
-	struct btrfs_inode_extref *extref;
 
 	key.objectid = inode_objectid;
 	key.type = BTRFS_INODE_EXTREF_KEY;
@@ -98,11 +90,9 @@
 		return ERR_PTR(ret);
 	if (ret > 0)
 		return NULL;
-	if (!btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
-					    ref_objectid, name, name_len,
-					    &extref))
-		return NULL;
-	return extref;
+	return btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
+					      ref_objectid, name, name_len);
+
 }
 
 static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
@@ -142,9 +132,9 @@
 	 * This should always succeed so error here will make the FS
 	 * readonly.
 	 */
-	if (!btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
-					    ref_objectid,
-					    name, name_len, &extref)) {
+	extref = btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
+						ref_objectid, name, name_len);
+	if (!extref) {
 		btrfs_handle_fs_error(root->fs_info, -ENOENT, NULL);
 		ret = -EROFS;
 		goto out;
@@ -170,7 +160,7 @@
 	memmove_extent_buffer(leaf, ptr, ptr + del_len,
 			      item_size - (ptr + del_len - item_start));
 
-	btrfs_truncate_item(root->fs_info, path, item_size - del_len, 1);
+	btrfs_truncate_item(path, item_size - del_len, 1);
 
 out:
 	btrfs_free_path(path);
@@ -213,8 +203,10 @@
 	} else if (ret < 0) {
 		goto out;
 	}
-	if (!btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
-					name, name_len, &ref)) {
+
+	ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0], name,
+					 name_len);
+	if (!ref) {
 		ret = -ENOENT;
 		search_ext_refs = 1;
 		goto out;
@@ -234,7 +226,7 @@
 	item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
 	memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
 			      item_size - (ptr + sub_item_len - item_start));
-	btrfs_truncate_item(root->fs_info, path, item_size - sub_item_len, 1);
+	btrfs_truncate_item(path, item_size - sub_item_len, 1);
 out:
 	btrfs_free_path(path);
 
@@ -285,10 +277,10 @@
 		if (btrfs_find_name_in_ext_backref(path->nodes[0],
 						   path->slots[0],
 						   ref_objectid,
-						   name, name_len, NULL))
+						   name, name_len))
 			goto out;
 
-		btrfs_extend_item(root->fs_info, path, ins_len);
+		btrfs_extend_item(path, ins_len);
 		ret = 0;
 	}
 	if (ret < 0)
@@ -341,13 +333,13 @@
 				      ins_len);
 	if (ret == -EEXIST) {
 		u32 old_size;
-
-		if (btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
-					       name, name_len, &ref))
+		ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
+						 name, name_len);
+		if (ref)
 			goto out;
 
 		old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
-		btrfs_extend_item(fs_info, path, ins_len);
+		btrfs_extend_item(path, ins_len);
 		ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
 				     struct btrfs_inode_ref);
 		ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
@@ -359,7 +351,7 @@
 		if (ret == -EOVERFLOW) {
 			if (btrfs_find_name_in_backref(path->nodes[0],
 						       path->slots[0],
-						       name, name_len, &ref))
+						       name, name_len))
 				ret = -EEXIST;
 			else
 				ret = -EMLINK;
diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c
index ffca2ab..37345fb 100644
--- a/fs/btrfs/inode-map.c
+++ b/fs/btrfs/inode-map.c
@@ -11,6 +11,20 @@
 #include "free-space-cache.h"
 #include "inode-map.h"
 #include "transaction.h"
+#include "delalloc-space.h"
+
+static void fail_caching_thread(struct btrfs_root *root)
+{
+	struct btrfs_fs_info *fs_info = root->fs_info;
+
+	btrfs_warn(fs_info, "failed to start inode caching task");
+	btrfs_clear_pending_and_info(fs_info, INODE_MAP_CACHE,
+				     "disabling inode map caching");
+	spin_lock(&root->ino_cache_lock);
+	root->ino_cache_state = BTRFS_CACHE_ERROR;
+	spin_unlock(&root->ino_cache_lock);
+	wake_up(&root->ino_cache_wait);
+}
 
 static int caching_kthread(void *data)
 {
@@ -28,8 +42,10 @@
 		return 0;
 
 	path = btrfs_alloc_path();
-	if (!path)
+	if (!path) {
+		fail_caching_thread(root);
 		return -ENOMEM;
+	}
 
 	/* Since the commit root is read-only, we can safely skip locking. */
 	path->skip_locking = 1;
@@ -145,6 +161,7 @@
 		spin_lock(&root->ino_cache_lock);
 		root->ino_cache_state = BTRFS_CACHE_FINISHED;
 		spin_unlock(&root->ino_cache_lock);
+		wake_up(&root->ino_cache_wait);
 		return;
 	}
 
@@ -159,15 +176,13 @@
 	if (!ret && objectid <= BTRFS_LAST_FREE_OBJECTID) {
 		__btrfs_add_free_space(fs_info, ctl, objectid,
 				       BTRFS_LAST_FREE_OBJECTID - objectid + 1);
+		wake_up(&root->ino_cache_wait);
 	}
 
 	tsk = kthread_run(caching_kthread, root, "btrfs-ino-cache-%llu",
 			  root->root_key.objectid);
-	if (IS_ERR(tsk)) {
-		btrfs_warn(fs_info, "failed to start inode caching task");
-		btrfs_clear_pending_and_info(fs_info, INODE_MAP_CACHE,
-					     "disabling inode map caching");
-	}
+	if (IS_ERR(tsk))
+		fail_caching_thread(root);
 }
 
 int btrfs_find_free_ino(struct btrfs_root *root, u64 *objectid)
@@ -185,11 +200,14 @@
 
 	wait_event(root->ino_cache_wait,
 		   root->ino_cache_state == BTRFS_CACHE_FINISHED ||
+		   root->ino_cache_state == BTRFS_CACHE_ERROR ||
 		   root->free_ino_ctl->free_space > 0);
 
 	if (root->ino_cache_state == BTRFS_CACHE_FINISHED &&
 	    root->free_ino_ctl->free_space == 0)
 		return -ENOSPC;
+	else if (root->ino_cache_state == BTRFS_CACHE_ERROR)
+		return btrfs_find_free_objectid(root, objectid);
 	else
 		goto again;
 }
@@ -418,7 +436,7 @@
 	 * 1 item for free space object
 	 * 3 items for pre-allocation
 	 */
-	trans->bytes_reserved = btrfs_calc_trans_metadata_size(fs_info, 10);
+	trans->bytes_reserved = btrfs_calc_insert_metadata_size(fs_info, 10);
 	ret = btrfs_block_rsv_add(root, trans->block_rsv,
 				  trans->bytes_reserved,
 				  BTRFS_RESERVE_NO_FLUSH);
@@ -483,12 +501,13 @@
 	ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, prealloc,
 					      prealloc, prealloc, &alloc_hint);
 	if (ret) {
-		btrfs_delalloc_release_extents(BTRFS_I(inode), prealloc, true);
+		btrfs_delalloc_release_extents(BTRFS_I(inode), prealloc);
+		btrfs_delalloc_release_metadata(BTRFS_I(inode), prealloc, true);
 		goto out_put;
 	}
 
 	ret = btrfs_write_out_ino_cache(root, trans, path, inode);
-	btrfs_delalloc_release_extents(BTRFS_I(inode), prealloc, false);
+	btrfs_delalloc_release_extents(BTRFS_I(inode), prealloc);
 out_put:
 	iput(inode);
 out_release:
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 7158b5b..0159100 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -27,7 +27,10 @@
 #include <linux/uio.h>
 #include <linux/magic.h>
 #include <linux/iversion.h>
+#include <linux/swap.h>
+#include <linux/sched/mm.h>
 #include <asm/unaligned.h>
+#include "misc.h"
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -44,7 +47,8 @@
 #include "backref.h"
 #include "props.h"
 #include "qgroup.h"
-#include "dedupe.h"
+#include "delalloc-space.h"
+#include "block-group.h"
 
 struct btrfs_iget_args {
 	struct btrfs_key *location;
@@ -64,7 +68,6 @@
 static const struct inode_operations btrfs_special_inode_operations;
 static const struct inode_operations btrfs_file_inode_operations;
 static const struct address_space_operations btrfs_aops;
-static const struct address_space_operations btrfs_symlink_aops;
 static const struct file_operations btrfs_dir_file_operations;
 static const struct extent_io_ops btrfs_extent_io_ops;
 
@@ -72,26 +75,15 @@
 struct kmem_cache *btrfs_trans_handle_cachep;
 struct kmem_cache *btrfs_path_cachep;
 struct kmem_cache *btrfs_free_space_cachep;
-
-#define S_SHIFT 12
-static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
-	[S_IFREG >> S_SHIFT]	= BTRFS_FT_REG_FILE,
-	[S_IFDIR >> S_SHIFT]	= BTRFS_FT_DIR,
-	[S_IFCHR >> S_SHIFT]	= BTRFS_FT_CHRDEV,
-	[S_IFBLK >> S_SHIFT]	= BTRFS_FT_BLKDEV,
-	[S_IFIFO >> S_SHIFT]	= BTRFS_FT_FIFO,
-	[S_IFSOCK >> S_SHIFT]	= BTRFS_FT_SOCK,
-	[S_IFLNK >> S_SHIFT]	= BTRFS_FT_SYMLINK,
-};
+struct kmem_cache *btrfs_free_space_bitmap_cachep;
 
 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
 static int btrfs_truncate(struct inode *inode, bool skip_writeback);
 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
 static noinline int cow_file_range(struct inode *inode,
 				   struct page *locked_page,
-				   u64 start, u64 end, u64 delalloc_end,
-				   int *page_started, unsigned long *nr_written,
-				   int unlock, struct btrfs_dedupe_hash *hash);
+				   u64 start, u64 end, int *page_started,
+				   unsigned long *nr_written, int unlock);
 static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
 				       u64 orig_start, u64 block_start,
 				       u64 block_len, u64 orig_block_len,
@@ -104,23 +96,23 @@
 
 /*
  * Cleanup all submitted ordered extents in specified range to handle errors
- * from the fill_dellaloc() callback.
+ * from the btrfs_run_delalloc_range() callback.
  *
  * NOTE: caller must ensure that when an error happens, it can not call
  * extent_clear_unlock_delalloc() to clear both the bits EXTENT_DO_ACCOUNTING
  * and EXTENT_DELALLOC simultaneously, because that causes the reserved metadata
  * to be released, which we want to happen only when finishing the ordered
- * extent (btrfs_finish_ordered_io()). Also note that the caller of the
- * fill_delalloc() callback already does proper cleanup for the first page of
- * the range, that is, it invokes the callback writepage_end_io_hook() for the
- * range of the first page.
+ * extent (btrfs_finish_ordered_io()).
  */
 static inline void btrfs_cleanup_ordered_extents(struct inode *inode,
-						 const u64 offset,
-						 const u64 bytes)
+						 struct page *locked_page,
+						 u64 offset, u64 bytes)
 {
 	unsigned long index = offset >> PAGE_SHIFT;
 	unsigned long end_index = (offset + bytes - 1) >> PAGE_SHIFT;
+	u64 page_start = page_offset(locked_page);
+	u64 page_end = page_start + PAGE_SIZE - 1;
+
 	struct page *page;
 
 	while (index <= end_index) {
@@ -131,8 +123,18 @@
 		ClearPagePrivate2(page);
 		put_page(page);
 	}
-	return __endio_write_update_ordered(inode, offset + PAGE_SIZE,
-					    bytes - PAGE_SIZE, false);
+
+	/*
+	 * In case this page belongs to the delalloc range being instantiated
+	 * then skip it, since the first page of a range is going to be
+	 * properly cleaned up by the caller of run_delalloc_range
+	 */
+	if (page_start >= offset && page_end <= (offset + bytes - 1)) {
+		offset += PAGE_SIZE;
+		bytes -= PAGE_SIZE;
+	}
+
+	return __endio_write_update_ordered(inode, offset, bytes, false);
 }
 
 static int btrfs_dirty_inode(struct inode *inode);
@@ -177,6 +179,9 @@
 	size_t cur_size = size;
 	unsigned long offset;
 
+	ASSERT((compressed_size > 0 && compressed_pages) ||
+	       (compressed_size == 0 && !compressed_pages));
+
 	if (compressed_size && compressed_pages)
 		cur_size = compressed_size;
 
@@ -230,7 +235,7 @@
 				     start >> PAGE_SHIFT);
 		btrfs_set_file_extent_compression(leaf, ei, 0);
 		kaddr = kmap_atomic(page);
-		offset = start & (PAGE_SIZE - 1);
+		offset = offset_in_page(start);
 		write_extent_buffer(leaf, kaddr + offset, ptr, size);
 		kunmap_atomic(kaddr);
 		put_page(page);
@@ -356,18 +361,24 @@
 	struct list_head list;
 };
 
-struct async_cow {
+struct async_chunk {
 	struct inode *inode;
-	struct btrfs_root *root;
 	struct page *locked_page;
 	u64 start;
 	u64 end;
 	unsigned int write_flags;
 	struct list_head extents;
 	struct btrfs_work work;
+	atomic_t *pending;
 };
 
-static noinline int add_async_extent(struct async_cow *cow,
+struct async_cow {
+	/* Number of chunks in flight; must be first in the structure */
+	atomic_t num_chunks;
+	struct async_chunk chunks[];
+};
+
+static noinline int add_async_extent(struct async_chunk *cow,
 				     u64 start, u64 ram_size,
 				     u64 compressed_size,
 				     struct page **pages,
@@ -388,10 +399,31 @@
 	return 0;
 }
 
+/*
+ * Check if the inode has flags compatible with compression
+ */
+static inline bool inode_can_compress(struct inode *inode)
+{
+	if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW ||
+	    BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
+		return false;
+	return true;
+}
+
+/*
+ * Check if the inode needs to be submitted to compression, based on mount
+ * options, defragmentation, properties or heuristics.
+ */
 static inline int inode_need_compress(struct inode *inode, u64 start, u64 end)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 
+	if (!inode_can_compress(inode)) {
+		WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG),
+			KERN_ERR "BTRFS: unexpected compression for ino %llu\n",
+			btrfs_ino(BTRFS_I(inode)));
+		return 0;
+	}
 	/* force compress */
 	if (btrfs_test_opt(fs_info, FORCE_COMPRESS))
 		return 1;
@@ -434,16 +466,15 @@
  * are written in the same order that the flusher thread sent them
  * down.
  */
-static noinline void compress_file_range(struct inode *inode,
-					struct page *locked_page,
-					u64 start, u64 end,
-					struct async_cow *async_cow,
-					int *num_added)
+static noinline int compress_file_range(struct async_chunk *async_chunk)
 {
+	struct inode *inode = async_chunk->inode;
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	u64 blocksize = fs_info->sectorsize;
+	u64 start = async_chunk->start;
+	u64 end = async_chunk->end;
 	u64 actual_end;
-	u64 isize = i_size_read(inode);
+	u64 i_size;
 	int ret = 0;
 	struct page **pages = NULL;
 	unsigned long nr_pages;
@@ -452,12 +483,25 @@
 	int i;
 	int will_compress;
 	int compress_type = fs_info->compress_type;
+	int compressed_extents = 0;
 	int redirty = 0;
 
 	inode_should_defrag(BTRFS_I(inode), start, end, end - start + 1,
 			SZ_16K);
 
-	actual_end = min_t(u64, isize, end + 1);
+	/*
+	 * We need to save i_size before now because it could change in between
+	 * us evaluating the size and assigning it.  This is because we lock and
+	 * unlock the page in truncate and fallocate, and then modify the i_size
+	 * later on.
+	 *
+	 * The barriers are to emulate READ_ONCE, remove that once i_size_read
+	 * does that for us.
+	 */
+	barrier();
+	i_size = i_size_read(inode);
+	barrier();
+	actual_end = min_t(u64, i_size, end + 1);
 again:
 	will_compress = 0;
 	nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
@@ -539,8 +583,7 @@
 					   &total_compressed);
 
 		if (!ret) {
-			unsigned long offset = total_compressed &
-				(PAGE_SIZE - 1);
+			unsigned long offset = offset_in_page(total_compressed);
 			struct page *page = pages[nr_pages - 1];
 			char *kaddr;
 
@@ -589,14 +632,21 @@
 			 * our outstanding extent for clearing delalloc for this
 			 * range.
 			 */
-			extent_clear_unlock_delalloc(inode, start, end, end,
-						     NULL, clear_flags,
+			extent_clear_unlock_delalloc(inode, start, end, NULL,
+						     clear_flags,
 						     PAGE_UNLOCK |
 						     PAGE_CLEAR_DIRTY |
 						     PAGE_SET_WRITEBACK |
 						     page_error_op |
 						     PAGE_END_WRITEBACK);
-			goto free_pages_out;
+
+			for (i = 0; i < nr_pages; i++) {
+				WARN_ON(pages[i]->mapping);
+				put_page(pages[i]);
+			}
+			kfree(pages);
+
+			return 0;
 		}
 	}
 
@@ -615,14 +665,14 @@
 		 */
 		total_in = ALIGN(total_in, PAGE_SIZE);
 		if (total_compressed + blocksize <= total_in) {
-			*num_added += 1;
+			compressed_extents++;
 
 			/*
 			 * The async work queues will take care of doing actual
 			 * allocation on disk for these compressed pages, and
 			 * will submit them to the elevator.
 			 */
-			add_async_extent(async_cow, start, total_in,
+			add_async_extent(async_chunk, start, total_in,
 					total_compressed, pages, nr_pages,
 					compress_type);
 
@@ -632,7 +682,7 @@
 				cond_resched();
 				goto again;
 			}
-			return;
+			return compressed_extents;
 		}
 	}
 	if (pages) {
@@ -662,25 +712,18 @@
 	 * to our extent and set things up for the async work queue to run
 	 * cow_file_range to do the normal delalloc dance.
 	 */
-	if (page_offset(locked_page) >= start &&
-	    page_offset(locked_page) <= end)
-		__set_page_dirty_nobuffers(locked_page);
+	if (page_offset(async_chunk->locked_page) >= start &&
+	    page_offset(async_chunk->locked_page) <= end)
+		__set_page_dirty_nobuffers(async_chunk->locked_page);
 		/* unlocked later on in the async handlers */
 
 	if (redirty)
 		extent_range_redirty_for_io(inode, start, end);
-	add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0,
+	add_async_extent(async_chunk, start, end - start + 1, 0, NULL, 0,
 			 BTRFS_COMPRESS_NONE);
-	*num_added += 1;
+	compressed_extents++;
 
-	return;
-
-free_pages_out:
-	for (i = 0; i < nr_pages; i++) {
-		WARN_ON(pages[i]->mapping);
-		put_page(pages[i]);
-	}
-	kfree(pages);
+	return compressed_extents;
 }
 
 static void free_async_extent_pages(struct async_extent *async_extent)
@@ -705,45 +748,38 @@
  * queued.  We walk all the async extents created by compress_file_range
  * and send them down to the disk.
  */
-static noinline void submit_compressed_extents(struct inode *inode,
-					      struct async_cow *async_cow)
+static noinline void submit_compressed_extents(struct async_chunk *async_chunk)
 {
+	struct inode *inode = async_chunk->inode;
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct async_extent *async_extent;
 	u64 alloc_hint = 0;
 	struct btrfs_key ins;
 	struct extent_map *em;
 	struct btrfs_root *root = BTRFS_I(inode)->root;
-	struct extent_io_tree *io_tree;
+	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 	int ret = 0;
 
 again:
-	while (!list_empty(&async_cow->extents)) {
-		async_extent = list_entry(async_cow->extents.next,
+	while (!list_empty(&async_chunk->extents)) {
+		async_extent = list_entry(async_chunk->extents.next,
 					  struct async_extent, list);
 		list_del(&async_extent->list);
 
-		io_tree = &BTRFS_I(inode)->io_tree;
-
 retry:
+		lock_extent(io_tree, async_extent->start,
+			    async_extent->start + async_extent->ram_size - 1);
 		/* did the compression code fall back to uncompressed IO? */
 		if (!async_extent->pages) {
 			int page_started = 0;
 			unsigned long nr_written = 0;
 
-			lock_extent(io_tree, async_extent->start,
-					 async_extent->start +
-					 async_extent->ram_size - 1);
-
 			/* allocate blocks */
-			ret = cow_file_range(inode, async_cow->locked_page,
+			ret = cow_file_range(inode, async_chunk->locked_page,
 					     async_extent->start,
 					     async_extent->start +
 					     async_extent->ram_size - 1,
-					     async_extent->start +
-					     async_extent->ram_size - 1,
-					     &page_started, &nr_written, 0,
-					     NULL);
+					     &page_started, &nr_written, 0);
 
 			/* JDM XXX */
 
@@ -760,15 +796,12 @@
 						  async_extent->ram_size - 1,
 						  WB_SYNC_ALL);
 			else if (ret)
-				unlock_page(async_cow->locked_page);
+				unlock_page(async_chunk->locked_page);
 			kfree(async_extent);
 			cond_resched();
 			continue;
 		}
 
-		lock_extent(io_tree, async_extent->start,
-			    async_extent->start + async_extent->ram_size - 1);
-
 		ret = btrfs_reserve_extent(root, async_extent->ram_size,
 					   async_extent->compressed_size,
 					   async_extent->compressed_size,
@@ -836,8 +869,6 @@
 		extent_clear_unlock_delalloc(inode, async_extent->start,
 				async_extent->start +
 				async_extent->ram_size - 1,
-				async_extent->start +
-				async_extent->ram_size - 1,
 				NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
 				PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
 				PAGE_SET_WRITEBACK);
@@ -847,17 +878,16 @@
 				    ins.objectid,
 				    ins.offset, async_extent->pages,
 				    async_extent->nr_pages,
-				    async_cow->write_flags)) {
-			struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
+				    async_chunk->write_flags)) {
 			struct page *p = async_extent->pages[0];
 			const u64 start = async_extent->start;
 			const u64 end = start + async_extent->ram_size - 1;
 
 			p->mapping = inode->i_mapping;
-			tree->ops->writepage_end_io_hook(p, start, end,
-							 NULL, 0);
+			btrfs_writepage_endio_finish_ordered(p, start, end, 0);
+
 			p->mapping = NULL;
-			extent_clear_unlock_delalloc(inode, start, end, end,
+			extent_clear_unlock_delalloc(inode, start, end,
 						     NULL, 0,
 						     PAGE_END_WRITEBACK |
 						     PAGE_SET_ERROR);
@@ -875,8 +905,6 @@
 	extent_clear_unlock_delalloc(inode, async_extent->start,
 				     async_extent->start +
 				     async_extent->ram_size - 1,
-				     async_extent->start +
-				     async_extent->ram_size - 1,
 				     NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
 				     EXTENT_DELALLOC_NEW |
 				     EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
@@ -935,9 +963,8 @@
  */
 static noinline int cow_file_range(struct inode *inode,
 				   struct page *locked_page,
-				   u64 start, u64 end, u64 delalloc_end,
-				   int *page_started, unsigned long *nr_written,
-				   int unlock, struct btrfs_dedupe_hash *hash)
+				   u64 start, u64 end, int *page_started,
+				   unsigned long *nr_written, int unlock)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_root *root = BTRFS_I(inode)->root;
@@ -976,8 +1003,7 @@
 			 * our outstanding extent for clearing delalloc for this
 			 * range.
 			 */
-			extent_clear_unlock_delalloc(inode, start, end,
-				     delalloc_end, NULL,
+			extent_clear_unlock_delalloc(inode, start, end, NULL,
 				     EXTENT_LOCKED | EXTENT_DELALLOC |
 				     EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
 				     EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
@@ -1060,7 +1086,7 @@
 
 		extent_clear_unlock_delalloc(inode, start,
 					     start + ram_size - 1,
-					     delalloc_end, locked_page,
+					     locked_page,
 					     EXTENT_LOCKED | EXTENT_DELALLOC,
 					     page_ops);
 		if (num_bytes < cur_alloc_size)
@@ -1105,7 +1131,6 @@
 	if (extent_reserved) {
 		extent_clear_unlock_delalloc(inode, start,
 					     start + cur_alloc_size,
-					     start + cur_alloc_size,
 					     locked_page,
 					     clear_bits,
 					     page_ops);
@@ -1113,8 +1138,7 @@
 		if (start >= end)
 			goto out;
 	}
-	extent_clear_unlock_delalloc(inode, start, end, delalloc_end,
-				     locked_page,
+	extent_clear_unlock_delalloc(inode, start, end, locked_page,
 				     clear_bits | EXTENT_CLEAR_DATA_RESV,
 				     page_ops);
 	goto out;
@@ -1125,16 +1149,15 @@
  */
 static noinline void async_cow_start(struct btrfs_work *work)
 {
-	struct async_cow *async_cow;
-	int num_added = 0;
-	async_cow = container_of(work, struct async_cow, work);
+	struct async_chunk *async_chunk;
+	int compressed_extents;
 
-	compress_file_range(async_cow->inode, async_cow->locked_page,
-			    async_cow->start, async_cow->end, async_cow,
-			    &num_added);
-	if (num_added == 0) {
-		btrfs_add_delayed_iput(async_cow->inode);
-		async_cow->inode = NULL;
+	async_chunk = container_of(work, struct async_chunk, work);
+
+	compressed_extents = compress_file_range(async_chunk);
+	if (compressed_extents == 0) {
+		btrfs_add_delayed_iput(async_chunk->inode);
+		async_chunk->inode = NULL;
 	}
 }
 
@@ -1143,16 +1166,12 @@
  */
 static noinline void async_cow_submit(struct btrfs_work *work)
 {
-	struct btrfs_fs_info *fs_info;
-	struct async_cow *async_cow;
-	struct btrfs_root *root;
+	struct async_chunk *async_chunk = container_of(work, struct async_chunk,
+						     work);
+	struct btrfs_fs_info *fs_info = btrfs_work_owner(work);
 	unsigned long nr_pages;
 
-	async_cow = container_of(work, struct async_cow, work);
-
-	root = async_cow->root;
-	fs_info = root->fs_info;
-	nr_pages = (async_cow->end - async_cow->start + PAGE_SIZE) >>
+	nr_pages = (async_chunk->end - async_chunk->start + PAGE_SIZE) >>
 		PAGE_SHIFT;
 
 	/* atomic_sub_return implies a barrier */
@@ -1160,17 +1179,29 @@
 	    5 * SZ_1M)
 		cond_wake_up_nomb(&fs_info->async_submit_wait);
 
-	if (async_cow->inode)
-		submit_compressed_extents(async_cow->inode, async_cow);
+	/*
+	 * ->inode could be NULL if async_chunk_start has failed to compress,
+	 * in which case we don't have anything to submit, yet we need to
+	 * always adjust ->async_delalloc_pages as its paired with the init
+	 * happening in cow_file_range_async
+	 */
+	if (async_chunk->inode)
+		submit_compressed_extents(async_chunk);
 }
 
 static noinline void async_cow_free(struct btrfs_work *work)
 {
-	struct async_cow *async_cow;
-	async_cow = container_of(work, struct async_cow, work);
-	if (async_cow->inode)
-		btrfs_add_delayed_iput(async_cow->inode);
-	kfree(async_cow);
+	struct async_chunk *async_chunk;
+
+	async_chunk = container_of(work, struct async_chunk, work);
+	if (async_chunk->inode)
+		btrfs_add_delayed_iput(async_chunk->inode);
+	/*
+	 * Since the pointer to 'pending' is at the beginning of the array of
+	 * async_chunk's, freeing it ensures the whole array has been freed.
+	 */
+	if (atomic_dec_and_test(async_chunk->pending))
+		kvfree(async_chunk->pending);
 }
 
 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
@@ -1179,41 +1210,73 @@
 				unsigned int write_flags)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
-	struct async_cow *async_cow;
-	struct btrfs_root *root = BTRFS_I(inode)->root;
+	struct async_cow *ctx;
+	struct async_chunk *async_chunk;
 	unsigned long nr_pages;
 	u64 cur_end;
+	u64 num_chunks = DIV_ROUND_UP(end - start, SZ_512K);
+	int i;
+	bool should_compress;
+	unsigned nofs_flag;
 
-	clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
-			 1, 0, NULL);
-	while (start < end) {
-		async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
-		BUG_ON(!async_cow); /* -ENOMEM */
-		async_cow->inode = igrab(inode);
-		async_cow->root = root;
-		async_cow->locked_page = locked_page;
-		async_cow->start = start;
-		async_cow->write_flags = write_flags;
+	unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
 
-		if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
-		    !btrfs_test_opt(fs_info, FORCE_COMPRESS))
-			cur_end = end;
-		else
+	if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
+	    !btrfs_test_opt(fs_info, FORCE_COMPRESS)) {
+		num_chunks = 1;
+		should_compress = false;
+	} else {
+		should_compress = true;
+	}
+
+	nofs_flag = memalloc_nofs_save();
+	ctx = kvmalloc(struct_size(ctx, chunks, num_chunks), GFP_KERNEL);
+	memalloc_nofs_restore(nofs_flag);
+
+	if (!ctx) {
+		unsigned clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC |
+			EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
+			EXTENT_DO_ACCOUNTING;
+		unsigned long page_ops = PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
+			PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
+			PAGE_SET_ERROR;
+
+		extent_clear_unlock_delalloc(inode, start, end, locked_page,
+					     clear_bits, page_ops);
+		return -ENOMEM;
+	}
+
+	async_chunk = ctx->chunks;
+	atomic_set(&ctx->num_chunks, num_chunks);
+
+	for (i = 0; i < num_chunks; i++) {
+		if (should_compress)
 			cur_end = min(end, start + SZ_512K - 1);
+		else
+			cur_end = end;
 
-		async_cow->end = cur_end;
-		INIT_LIST_HEAD(&async_cow->extents);
+		/*
+		 * igrab is called higher up in the call chain, take only the
+		 * lightweight reference for the callback lifetime
+		 */
+		ihold(inode);
+		async_chunk[i].pending = &ctx->num_chunks;
+		async_chunk[i].inode = inode;
+		async_chunk[i].start = start;
+		async_chunk[i].end = cur_end;
+		async_chunk[i].locked_page = locked_page;
+		async_chunk[i].write_flags = write_flags;
+		INIT_LIST_HEAD(&async_chunk[i].extents);
 
-		btrfs_init_work(&async_cow->work,
+		btrfs_init_work(&async_chunk[i].work,
 				btrfs_delalloc_helper,
 				async_cow_start, async_cow_submit,
 				async_cow_free);
 
-		nr_pages = (cur_end - start + PAGE_SIZE) >>
-			PAGE_SHIFT;
+		nr_pages = DIV_ROUND_UP(cur_end - start, PAGE_SIZE);
 		atomic_add(nr_pages, &fs_info->async_delalloc_pages);
 
-		btrfs_queue_work(fs_info->delalloc_workers, &async_cow->work);
+		btrfs_queue_work(fs_info->delalloc_workers, &async_chunk[i].work);
 
 		*nr_written += nr_pages;
 		start = cur_end + 1;
@@ -1253,36 +1316,25 @@
  */
 static noinline int run_delalloc_nocow(struct inode *inode,
 				       struct page *locked_page,
-			      u64 start, u64 end, int *page_started, int force,
-			      unsigned long *nr_written)
+				       const u64 start, const u64 end,
+				       int *page_started, int force,
+				       unsigned long *nr_written)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_root *root = BTRFS_I(inode)->root;
-	struct extent_buffer *leaf;
 	struct btrfs_path *path;
-	struct btrfs_file_extent_item *fi;
-	struct btrfs_key found_key;
-	struct extent_map *em;
-	u64 cow_start;
-	u64 cur_offset;
-	u64 extent_end;
-	u64 extent_offset;
-	u64 disk_bytenr;
-	u64 num_bytes;
-	u64 disk_num_bytes;
-	u64 ram_bytes;
-	int extent_type;
+	u64 cow_start = (u64)-1;
+	u64 cur_offset = start;
 	int ret;
-	int type;
-	int nocow;
-	int check_prev = 1;
-	bool nolock;
+	bool check_prev = true;
+	const bool freespace_inode = btrfs_is_free_space_inode(BTRFS_I(inode));
 	u64 ino = btrfs_ino(BTRFS_I(inode));
+	bool nocow = false;
+	u64 disk_bytenr = 0;
 
 	path = btrfs_alloc_path();
 	if (!path) {
-		extent_clear_unlock_delalloc(inode, start, end, end,
-					     locked_page,
+		extent_clear_unlock_delalloc(inode, start, end, locked_page,
 					     EXTENT_LOCKED | EXTENT_DELALLOC |
 					     EXTENT_DO_ACCOUNTING |
 					     EXTENT_DEFRAG, PAGE_UNLOCK |
@@ -1292,15 +1344,29 @@
 		return -ENOMEM;
 	}
 
-	nolock = btrfs_is_free_space_inode(BTRFS_I(inode));
-
-	cow_start = (u64)-1;
-	cur_offset = start;
 	while (1) {
+		struct btrfs_key found_key;
+		struct btrfs_file_extent_item *fi;
+		struct extent_buffer *leaf;
+		u64 extent_end;
+		u64 extent_offset;
+		u64 num_bytes = 0;
+		u64 disk_num_bytes;
+		u64 ram_bytes;
+		int extent_type;
+
+		nocow = false;
+
 		ret = btrfs_lookup_file_extent(NULL, root, path, ino,
 					       cur_offset, 0);
 		if (ret < 0)
 			goto error;
+
+		/*
+		 * If there is no extent for our range when doing the initial
+		 * search, then go back to the previous slot as it will be the
+		 * one containing the search offset
+		 */
 		if (ret > 0 && path->slots[0] > 0 && check_prev) {
 			leaf = path->nodes[0];
 			btrfs_item_key_to_cpu(leaf, &found_key,
@@ -1309,8 +1375,9 @@
 			    found_key.type == BTRFS_EXTENT_DATA_KEY)
 				path->slots[0]--;
 		}
-		check_prev = 0;
+		check_prev = false;
 next_slot:
+		/* Go to next leaf if we have exhausted the current one */
 		leaf = path->nodes[0];
 		if (path->slots[0] >= btrfs_header_nritems(leaf)) {
 			ret = btrfs_next_leaf(root, path);
@@ -1324,28 +1391,40 @@
 			leaf = path->nodes[0];
 		}
 
-		nocow = 0;
-		disk_bytenr = 0;
-		num_bytes = 0;
 		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 
+		/* Didn't find anything for our INO */
 		if (found_key.objectid > ino)
 			break;
+		/*
+		 * Keep searching until we find an EXTENT_ITEM or there are no
+		 * more extents for this inode
+		 */
 		if (WARN_ON_ONCE(found_key.objectid < ino) ||
 		    found_key.type < BTRFS_EXTENT_DATA_KEY) {
 			path->slots[0]++;
 			goto next_slot;
 		}
+
+		/* Found key is not EXTENT_DATA_KEY or starts after req range */
 		if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
 		    found_key.offset > end)
 			break;
 
+		/*
+		 * If the found extent starts after requested offset, then
+		 * adjust extent_end to be right before this extent begins
+		 */
 		if (found_key.offset > cur_offset) {
 			extent_end = found_key.offset;
 			extent_type = 0;
 			goto out_check;
 		}
 
+		/*
+		 * Found extent which begins before our range and potentially
+		 * intersect it
+		 */
 		fi = btrfs_item_ptr(leaf, path->slots[0],
 				    struct btrfs_file_extent_item);
 		extent_type = btrfs_file_extent_type(leaf, fi);
@@ -1359,25 +1438,36 @@
 				btrfs_file_extent_num_bytes(leaf, fi);
 			disk_num_bytes =
 				btrfs_file_extent_disk_num_bytes(leaf, fi);
+			/*
+			 * If extent we got ends before our range starts, skip
+			 * to next extent
+			 */
 			if (extent_end <= start) {
 				path->slots[0]++;
 				goto next_slot;
 			}
+			/* Skip holes */
 			if (disk_bytenr == 0)
 				goto out_check;
+			/* Skip compressed/encrypted/encoded extents */
 			if (btrfs_file_extent_compression(leaf, fi) ||
 			    btrfs_file_extent_encryption(leaf, fi) ||
 			    btrfs_file_extent_other_encoding(leaf, fi))
 				goto out_check;
 			/*
-			 * Do the same check as in btrfs_cross_ref_exist but
-			 * without the unnecessary search.
+			 * If extent is created before the last volume's snapshot
+			 * this implies the extent is shared, hence we can't do
+			 * nocow. This is the same check as in
+			 * btrfs_cross_ref_exist but without calling
+			 * btrfs_search_slot.
 			 */
-			if (btrfs_file_extent_generation(leaf, fi) <=
+			if (!freespace_inode &&
+			    btrfs_file_extent_generation(leaf, fi) <=
 			    btrfs_root_last_snapshot(&root->root_item))
 				goto out_check;
 			if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
 				goto out_check;
+			/* If extent is RO, we must COW it */
 			if (btrfs_extent_readonly(fs_info, disk_bytenr))
 				goto out_check;
 			ret = btrfs_cross_ref_exist(root, ino,
@@ -1394,17 +1484,17 @@
 					goto error;
 				}
 
-				WARN_ON_ONCE(nolock);
+				WARN_ON_ONCE(freespace_inode);
 				goto out_check;
 			}
 			disk_bytenr += extent_offset;
 			disk_bytenr += cur_offset - found_key.offset;
 			num_bytes = min(end + 1, extent_end) - cur_offset;
 			/*
-			 * if there are pending snapshots for this root,
-			 * we fall into common COW way.
+			 * If there are pending snapshots for this root, we
+			 * fall into common COW way
 			 */
-			if (!nolock && atomic_read(&root->snapshot_force_cow))
+			if (!freespace_inode && atomic_read(&root->snapshot_force_cow))
 				goto out_check;
 			/*
 			 * force cow if csum exists in the range.
@@ -1423,27 +1513,29 @@
 						cur_offset = cow_start;
 					goto error;
 				}
-				WARN_ON_ONCE(nolock);
+				WARN_ON_ONCE(freespace_inode);
 				goto out_check;
 			}
 			if (!btrfs_inc_nocow_writers(fs_info, disk_bytenr))
 				goto out_check;
-			nocow = 1;
+			nocow = true;
 		} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
-			extent_end = found_key.offset +
-				btrfs_file_extent_ram_bytes(leaf, fi);
-			extent_end = ALIGN(extent_end,
-					   fs_info->sectorsize);
+			extent_end = found_key.offset + ram_bytes;
+			extent_end = ALIGN(extent_end, fs_info->sectorsize);
+			/* Skip extents outside of our requested range */
+			if (extent_end <= start) {
+				path->slots[0]++;
+				goto next_slot;
+			}
 		} else {
-			BUG_ON(1);
+			/* If this triggers then we have a memory corruption */
+			BUG();
 		}
 out_check:
-		if (extent_end <= start) {
-			path->slots[0]++;
-			if (nocow)
-				btrfs_dec_nocow_writers(fs_info, disk_bytenr);
-			goto next_slot;
-		}
+		/*
+		 * If nocow is false then record the beginning of the range
+		 * that needs to be COWed
+		 */
 		if (!nocow) {
 			if (cow_start == (u64)-1)
 				cow_start = cur_offset;
@@ -1455,11 +1547,16 @@
 		}
 
 		btrfs_release_path(path);
+
+		/*
+		 * COW range from cow_start to found_key.offset - 1. As the key
+		 * will contain the beginning of the first extent that can be
+		 * NOCOW, following one which needs to be COW'ed
+		 */
 		if (cow_start != (u64)-1) {
 			ret = cow_file_range(inode, locked_page,
 					     cow_start, found_key.offset - 1,
-					     end, page_started, nr_written, 1,
-					     NULL);
+					     page_started, nr_written, 1);
 			if (ret) {
 				if (nocow)
 					btrfs_dec_nocow_writers(fs_info,
@@ -1471,6 +1568,7 @@
 
 		if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
 			u64 orig_start = found_key.offset - extent_offset;
+			struct extent_map *em;
 
 			em = create_io_em(inode, cur_offset, num_bytes,
 					  orig_start,
@@ -1487,19 +1585,29 @@
 				goto error;
 			}
 			free_extent_map(em);
-		}
-
-		if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
-			type = BTRFS_ORDERED_PREALLOC;
+			ret = btrfs_add_ordered_extent(inode, cur_offset,
+						       disk_bytenr, num_bytes,
+						       num_bytes,
+						       BTRFS_ORDERED_PREALLOC);
+			if (ret) {
+				btrfs_drop_extent_cache(BTRFS_I(inode),
+							cur_offset,
+							cur_offset + num_bytes - 1,
+							0);
+				goto error;
+			}
 		} else {
-			type = BTRFS_ORDERED_NOCOW;
+			ret = btrfs_add_ordered_extent(inode, cur_offset,
+						       disk_bytenr, num_bytes,
+						       num_bytes,
+						       BTRFS_ORDERED_NOCOW);
+			if (ret)
+				goto error;
 		}
 
-		ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
-					       num_bytes, num_bytes, type);
 		if (nocow)
 			btrfs_dec_nocow_writers(fs_info, disk_bytenr);
-		BUG_ON(ret); /* -ENOMEM */
+		nocow = false;
 
 		if (root->root_key.objectid ==
 		    BTRFS_DATA_RELOC_TREE_OBJECTID)
@@ -1512,7 +1620,7 @@
 						      num_bytes);
 
 		extent_clear_unlock_delalloc(inode, cur_offset,
-					     cur_offset + num_bytes - 1, end,
+					     cur_offset + num_bytes - 1,
 					     locked_page, EXTENT_LOCKED |
 					     EXTENT_DELALLOC |
 					     EXTENT_CLEAR_DATA_RESV,
@@ -1537,15 +1645,18 @@
 
 	if (cow_start != (u64)-1) {
 		cur_offset = end;
-		ret = cow_file_range(inode, locked_page, cow_start, end, end,
-				     page_started, nr_written, 1, NULL);
+		ret = cow_file_range(inode, locked_page, cow_start, end,
+				     page_started, nr_written, 1);
 		if (ret)
 			goto error;
 	}
 
 error:
+	if (nocow)
+		btrfs_dec_nocow_writers(fs_info, disk_bytenr);
+
 	if (ret && cur_offset < end)
-		extent_clear_unlock_delalloc(inode, cur_offset, end, end,
+		extent_clear_unlock_delalloc(inode, cur_offset, end,
 					     locked_page, EXTENT_LOCKED |
 					     EXTENT_DELALLOC | EXTENT_DEFRAG |
 					     EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
@@ -1577,14 +1688,13 @@
 }
 
 /*
- * extent_io.c call back to do delayed allocation processing
+ * Function to process delayed allocation (create CoW) for ranges which are
+ * being touched for the first time.
  */
-static int run_delalloc_range(void *private_data, struct page *locked_page,
-			      u64 start, u64 end, int *page_started,
-			      unsigned long *nr_written,
-			      struct writeback_control *wbc)
+int btrfs_run_delalloc_range(struct inode *inode, struct page *locked_page,
+		u64 start, u64 end, int *page_started, unsigned long *nr_written,
+		struct writeback_control *wbc)
 {
-	struct inode *inode = private_data;
 	int ret;
 	int force_cow = need_force_cow(inode, start, end);
 	unsigned int write_flags = wbc_to_write_flags(wbc);
@@ -1595,9 +1705,10 @@
 	} else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
 		ret = run_delalloc_nocow(inode, locked_page, start, end,
 					 page_started, 0, nr_written);
-	} else if (!inode_need_compress(inode, start, end)) {
-		ret = cow_file_range(inode, locked_page, start, end, end,
-				      page_started, nr_written, 1, NULL);
+	} else if (!inode_can_compress(inode) ||
+		   !inode_need_compress(inode, start, end)) {
+		ret = cow_file_range(inode, locked_page, start, end,
+				      page_started, nr_written, 1);
 	} else {
 		set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
 			&BTRFS_I(inode)->runtime_flags);
@@ -1606,14 +1717,14 @@
 					   write_flags);
 	}
 	if (ret)
-		btrfs_cleanup_ordered_extents(inode, start, end - start + 1);
+		btrfs_cleanup_ordered_extents(inode, locked_page, start,
+					      end - start + 1);
 	return ret;
 }
 
-static void btrfs_split_extent_hook(void *private_data,
-				    struct extent_state *orig, u64 split)
+void btrfs_split_delalloc_extent(struct inode *inode,
+				 struct extent_state *orig, u64 split)
 {
-	struct inode *inode = private_data;
 	u64 size;
 
 	/* not delalloc, ignore it */
@@ -1626,7 +1737,7 @@
 		u64 new_size;
 
 		/*
-		 * See the explanation in btrfs_merge_extent_hook, the same
+		 * See the explanation in btrfs_merge_delalloc_extent, the same
 		 * applies here, just in reverse.
 		 */
 		new_size = orig->end - split + 1;
@@ -1643,16 +1754,13 @@
 }
 
 /*
- * extent_io.c merge_extent_hook, used to track merged delayed allocation
- * extents so we can keep track of new extents that are just merged onto old
- * extents, such as when we are doing sequential writes, so we can properly
- * account for the metadata space we'll need.
+ * Handle merged delayed allocation extents so we can keep track of new extents
+ * that are just merged onto old extents, such as when we are doing sequential
+ * writes, so we can properly account for the metadata space we'll need.
  */
-static void btrfs_merge_extent_hook(void *private_data,
-				    struct extent_state *new,
-				    struct extent_state *other)
+void btrfs_merge_delalloc_extent(struct inode *inode, struct extent_state *new,
+				 struct extent_state *other)
 {
-	struct inode *inode = private_data;
 	u64 new_size, old_size;
 	u32 num_extents;
 
@@ -1756,15 +1864,12 @@
 }
 
 /*
- * extent_io.c set_bit_hook, used to track delayed allocation
- * bytes in this file, and to maintain the list of inodes that
- * have pending delalloc work to be done.
+ * Properly track delayed allocation bytes in the inode and to maintain the
+ * list of inodes that have pending delalloc work to be done.
  */
-static void btrfs_set_bit_hook(void *private_data,
-			       struct extent_state *state, unsigned *bits)
+void btrfs_set_delalloc_extent(struct inode *inode, struct extent_state *state,
+			       unsigned *bits)
 {
-	struct inode *inode = private_data;
-
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 
 	if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
@@ -1810,14 +1915,14 @@
 }
 
 /*
- * extent_io.c clear_bit_hook, see set_bit_hook for why
+ * Once a range is no longer delalloc this function ensures that proper
+ * accounting happens.
  */
-static void btrfs_clear_bit_hook(void *private_data,
-				 struct extent_state *state,
-				 unsigned *bits)
+void btrfs_clear_delalloc_extent(struct inode *vfs_inode,
+				 struct extent_state *state, unsigned *bits)
 {
-	struct btrfs_inode *inode = BTRFS_I((struct inode *)private_data);
-	struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
+	struct btrfs_inode *inode = BTRFS_I(vfs_inode);
+	struct btrfs_fs_info *fs_info = btrfs_sb(vfs_inode->i_sb);
 	u64 len = state->end + 1 - state->start;
 	u32 num_extents = count_max_extents(len);
 
@@ -1842,7 +1947,7 @@
 
 		/*
 		 * We don't reserve metadata space for space cache inodes so we
-		 * don't need to call dellalloc_release_metadata if there is an
+		 * don't need to call delalloc_release_metadata if there is an
 		 * error.
 		 */
 		if (*bits & EXTENT_CLEAR_META_RESV &&
@@ -1881,16 +1986,21 @@
 }
 
 /*
- * Merge bio hook, this must check the chunk tree to make sure we don't create
- * bios that span stripes or chunks
+ * btrfs_bio_fits_in_stripe - Checks whether the size of the given bio will fit
+ * in a chunk's stripe. This function ensures that bios do not span a
+ * stripe/chunk
  *
- * return 1 if page cannot be merged to bio
- * return 0 if page can be merged to bio
+ * @page - The page we are about to add to the bio
+ * @size - size we want to add to the bio
+ * @bio - bio we want to ensure is smaller than a stripe
+ * @bio_flags - flags of the bio
+ *
+ * return 1 if page cannot be added to the bio
+ * return 0 if page can be added to the bio
  * return error otherwise
  */
-int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
-			 size_t size, struct bio *bio,
-			 unsigned long bio_flags)
+int btrfs_bio_fits_in_stripe(struct page *page, size_t size, struct bio *bio,
+			     unsigned long bio_flags)
 {
 	struct inode *inode = page->mapping->host;
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
@@ -1898,17 +2008,19 @@
 	u64 length = 0;
 	u64 map_length;
 	int ret;
+	struct btrfs_io_geometry geom;
 
 	if (bio_flags & EXTENT_BIO_COMPRESSED)
 		return 0;
 
 	length = bio->bi_iter.bi_size;
 	map_length = length;
-	ret = btrfs_map_block(fs_info, btrfs_op(bio), logical, &map_length,
-			      NULL, 0);
+	ret = btrfs_get_io_geometry(fs_info, btrfs_op(bio), logical, map_length,
+				    &geom);
 	if (ret < 0)
 		return ret;
-	if (map_length < length + size)
+
+	if (geom.len < length + size)
 		return 1;
 	return 0;
 }
@@ -1933,29 +2045,6 @@
 }
 
 /*
- * in order to insert checksums into the metadata in large chunks,
- * we wait until bio submission time.   All the pages in the bio are
- * checksummed and sums are attached onto the ordered extent record.
- *
- * At IO completion time the cums attached on the ordered extent record
- * are inserted into the btree
- */
-blk_status_t btrfs_submit_bio_done(void *private_data, struct bio *bio,
-			  int mirror_num)
-{
-	struct inode *inode = private_data;
-	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
-	blk_status_t ret;
-
-	ret = btrfs_map_bio(fs_info, bio, mirror_num, 1);
-	if (ret) {
-		bio->bi_status = ret;
-		bio_endio(bio);
-	}
-	return ret;
-}
-
-/*
  * extent_io.c submission hook. This does the right thing for csum calculation
  * on write, or reading the csums from the tree before a read.
  *
@@ -1973,11 +2062,11 @@
  *
  *    c-3) otherwise:			async submit
  */
-static blk_status_t btrfs_submit_bio_hook(void *private_data, struct bio *bio,
-				 int mirror_num, unsigned long bio_flags,
-				 u64 bio_offset)
+static blk_status_t btrfs_submit_bio_hook(struct inode *inode, struct bio *bio,
+					  int mirror_num,
+					  unsigned long bio_flags)
+
 {
-	struct inode *inode = private_data;
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
@@ -2012,8 +2101,7 @@
 			goto mapit;
 		/* we're doing a write, do the async checksumming */
 		ret = btrfs_wq_submit_bio(fs_info, bio, mirror_num, bio_flags,
-					  bio_offset, inode,
-					  btrfs_submit_bio_start);
+					  0, inode, btrfs_submit_bio_start);
 		goto out;
 	} else if (!skip_sum) {
 		ret = btrfs_csum_one_bio(inode, bio, 0, 0);
@@ -2055,9 +2143,9 @@
 
 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
 			      unsigned int extra_bits,
-			      struct extent_state **cached_state, int dedupe)
+			      struct extent_state **cached_state)
 {
-	WARN_ON((end & (PAGE_SIZE - 1)) == 0);
+	WARN_ON(PAGE_ALIGNED(end));
 	return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
 				   extra_bits, cached_state);
 }
@@ -2121,7 +2209,7 @@
 	 }
 
 	ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 0,
-					&cached_state, 0);
+					&cached_state);
 	if (ret) {
 		mapping_set_error(page->mapping, ret);
 		end_extent_writepage(page, ret, page_start, page_end);
@@ -2131,7 +2219,7 @@
 
 	ClearPageChecked(page);
 	set_page_dirty(page);
-	btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE, false);
+	btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
 out:
 	unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
 			     &cached_state);
@@ -2153,7 +2241,7 @@
  * to fix it up.  The async helper will wait for ordered extents, set
  * the delalloc bit and make it safe to write the page.
  */
-static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
+int btrfs_writepage_cow_fixup(struct page *page, u64 start, u64 end)
 {
 	struct inode *inode = page->mapping->host;
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
@@ -2540,6 +2628,7 @@
 	struct btrfs_file_extent_item *item;
 	struct btrfs_ordered_extent *ordered;
 	struct btrfs_trans_handle *trans;
+	struct btrfs_ref ref = { 0 };
 	struct btrfs_root *root;
 	struct btrfs_key key;
 	struct extent_buffer *leaf;
@@ -2710,10 +2799,11 @@
 	inode_add_bytes(inode, len);
 	btrfs_release_path(path);
 
-	ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
-			new->disk_len, 0,
-			backref->root_id, backref->inum,
-			new->file_pos);	/* start - extent_offset */
+	btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, new->bytenr,
+			       new->disk_len, 0);
+	btrfs_init_data_ref(&ref, backref->root_id, backref->inum,
+			    new->file_pos);  /* start - extent_offset */
+	ret = btrfs_inc_extent_ref(trans, &ref);
 	if (ret) {
 		btrfs_abort_transaction(trans, ret);
 		goto out_free_path;
@@ -2750,12 +2840,9 @@
 	struct btrfs_path *path;
 	struct sa_defrag_extent_backref *backref;
 	struct sa_defrag_extent_backref *prev = NULL;
-	struct inode *inode;
 	struct rb_node *node;
 	int ret;
 
-	inode = new->inode;
-
 	path = btrfs_alloc_path();
 	if (!path)
 		return;
@@ -3150,9 +3237,6 @@
 	/* once for the tree */
 	btrfs_put_ordered_extent(ordered_extent);
 
-	/* Try to release some metadata so we don't get an OOM but don't wait */
-	btrfs_btree_balance_dirty_nodelay(fs_info);
-
 	return ret;
 }
 
@@ -3163,8 +3247,8 @@
 	btrfs_finish_ordered_io(ordered_extent);
 }
 
-static void btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
-				struct extent_state *state, int uptodate)
+void btrfs_writepage_endio_finish_ordered(struct page *page, u64 start,
+					  u64 end, int uptodate)
 {
 	struct inode *inode = page->mapping->host;
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
@@ -3197,16 +3281,23 @@
 				  int icsum, struct page *page,
 				  int pgoff, u64 start, size_t len)
 {
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
 	char *kaddr;
-	u32 csum_expected;
-	u32 csum = ~(u32)0;
+	u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
+	u8 *csum_expected;
+	u8 csum[BTRFS_CSUM_SIZE];
 
-	csum_expected = *(((u32 *)io_bio->csum) + icsum);
+	csum_expected = ((u8 *)io_bio->csum) + icsum * csum_size;
 
 	kaddr = kmap_atomic(page);
-	csum = btrfs_csum_data(kaddr + pgoff, csum,  len);
-	btrfs_csum_final(csum, (u8 *)&csum);
-	if (csum != csum_expected)
+	shash->tfm = fs_info->csum_shash;
+
+	crypto_shash_init(shash);
+	crypto_shash_update(shash, kaddr + pgoff, len);
+	crypto_shash_final(shash, csum);
+
+	if (memcmp(csum, csum_expected, csum_size))
 		goto zeroit;
 
 	kunmap_atomic(kaddr);
@@ -3271,10 +3362,35 @@
 	if (atomic_add_unless(&inode->i_count, -1, 1))
 		return;
 
+	atomic_inc(&fs_info->nr_delayed_iputs);
 	spin_lock(&fs_info->delayed_iput_lock);
 	ASSERT(list_empty(&binode->delayed_iput));
 	list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
 	spin_unlock(&fs_info->delayed_iput_lock);
+	if (!test_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags))
+		wake_up_process(fs_info->cleaner_kthread);
+}
+
+static void run_delayed_iput_locked(struct btrfs_fs_info *fs_info,
+				    struct btrfs_inode *inode)
+{
+	list_del_init(&inode->delayed_iput);
+	spin_unlock(&fs_info->delayed_iput_lock);
+	iput(&inode->vfs_inode);
+	if (atomic_dec_and_test(&fs_info->nr_delayed_iputs))
+		wake_up(&fs_info->delayed_iputs_wait);
+	spin_lock(&fs_info->delayed_iput_lock);
+}
+
+static void btrfs_run_delayed_iput(struct btrfs_fs_info *fs_info,
+				   struct btrfs_inode *inode)
+{
+	if (!list_empty(&inode->delayed_iput)) {
+		spin_lock(&fs_info->delayed_iput_lock);
+		if (!list_empty(&inode->delayed_iput))
+			run_delayed_iput_locked(fs_info, inode);
+		spin_unlock(&fs_info->delayed_iput_lock);
+	}
 }
 
 void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info)
@@ -3286,14 +3402,30 @@
 
 		inode = list_first_entry(&fs_info->delayed_iputs,
 				struct btrfs_inode, delayed_iput);
-		list_del_init(&inode->delayed_iput);
-		spin_unlock(&fs_info->delayed_iput_lock);
-		iput(&inode->vfs_inode);
-		spin_lock(&fs_info->delayed_iput_lock);
+		run_delayed_iput_locked(fs_info, inode);
 	}
 	spin_unlock(&fs_info->delayed_iput_lock);
 }
 
+/**
+ * btrfs_wait_on_delayed_iputs - wait on the delayed iputs to be done running
+ * @fs_info - the fs_info for this fs
+ * @return - EINTR if we were killed, 0 if nothing's pending
+ *
+ * This will wait on any delayed iputs that are currently running with KILLABLE
+ * set.  Once they are all done running we will return, unless we are killed in
+ * which case we return EINTR. This helps in user operations like fallocate etc
+ * that might get blocked on the iputs.
+ */
+int btrfs_wait_on_delayed_iputs(struct btrfs_fs_info *fs_info)
+{
+	int ret = wait_event_killable(fs_info->delayed_iputs_wait,
+			atomic_read(&fs_info->nr_delayed_iputs) == 0);
+	if (ret)
+		return -EINTR;
+	return 0;
+}
+
 /*
  * This creates an orphan entry for the given inode in case something goes wrong
  * in the middle of an unlink.
@@ -3479,8 +3611,6 @@
 
 		/* this will do delete_inode and everything for us */
 		iput(inode);
-		if (ret)
-			goto out;
 	}
 	/* release the path since we're done with it */
 	btrfs_release_path(path);
@@ -3575,10 +3705,11 @@
 /*
  * read an inode from the btree into the in-memory inode
  */
-static int btrfs_read_locked_inode(struct inode *inode)
+static int btrfs_read_locked_inode(struct inode *inode,
+				   struct btrfs_path *in_path)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
-	struct btrfs_path *path;
+	struct btrfs_path *path = in_path;
 	struct extent_buffer *leaf;
 	struct btrfs_inode_item *inode_item;
 	struct btrfs_root *root = BTRFS_I(inode)->root;
@@ -3594,15 +3725,18 @@
 	if (!ret)
 		filled = true;
 
-	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOMEM;
+	if (!path) {
+		path = btrfs_alloc_path();
+		if (!path)
+			return -ENOMEM;
+	}
 
 	memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
 
 	ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
 	if (ret) {
-		btrfs_free_path(path);
+		if (path != in_path)
+			btrfs_free_path(path);
 		return ret;
 	}
 
@@ -3727,7 +3861,8 @@
 				  btrfs_ino(BTRFS_I(inode)),
 				  root->root_key.objectid, ret);
 	}
-	btrfs_free_path(path);
+	if (path != in_path)
+		btrfs_free_path(path);
 
 	if (!maybe_acls)
 		cache_no_acl(inode);
@@ -3746,7 +3881,7 @@
 	case S_IFLNK:
 		inode->i_op = &btrfs_symlink_inode_operations;
 		inode_nohighmem(inode);
-		inode->i_mapping->a_ops = &btrfs_symlink_aops;
+		inode->i_mapping->a_ops = &btrfs_aops;
 		break;
 	default:
 		inode->i_op = &btrfs_special_inode_operations;
@@ -3768,7 +3903,7 @@
 {
 	struct btrfs_map_token token;
 
-	btrfs_init_map_token(&token);
+	btrfs_init_map_token(&token, leaf);
 
 	btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
 	btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
@@ -3902,9 +4037,7 @@
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_path *path;
 	int ret = 0;
-	struct extent_buffer *leaf;
 	struct btrfs_dir_item *di;
-	struct btrfs_key key;
 	u64 index;
 	u64 ino = btrfs_ino(inode);
 	u64 dir_ino = btrfs_ino(dir);
@@ -3918,16 +4051,10 @@
 	path->leave_spinning = 1;
 	di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
 				    name, name_len, -1);
-	if (IS_ERR(di)) {
-		ret = PTR_ERR(di);
+	if (IS_ERR_OR_NULL(di)) {
+		ret = di ? PTR_ERR(di) : -ENOENT;
 		goto err;
 	}
-	if (!di) {
-		ret = -ENOENT;
-		goto err;
-	}
-	leaf = path->nodes[0];
-	btrfs_dir_item_key_to_cpu(leaf, di, &key);
 	ret = btrfs_delete_one_dir_name(trans, root, path, di);
 	if (ret)
 		goto err;
@@ -3980,6 +4107,17 @@
 		ret = 0;
 	else if (ret)
 		btrfs_abort_transaction(trans, ret);
+
+	/*
+	 * If we have a pending delayed iput we could end up with the final iput
+	 * being run in btrfs-cleaner context.  If we have enough of these built
+	 * up we can end up burning a lot of time in btrfs-cleaner without any
+	 * way to throttle the unlinks.  Since we're currently holding a ref on
+	 * the inode we can run the delayed iput here without any issues as the
+	 * final iput won't be done until after we drop the ref we're currently
+	 * holding.
+	 */
+	btrfs_run_delayed_iput(fs_info, inode);
 err:
 	btrfs_free_path(path);
 	if (ret)
@@ -4083,10 +4221,7 @@
 	di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
 				   name, name_len, -1);
 	if (IS_ERR_OR_NULL(di)) {
-		if (!di)
-			ret = -ENOENT;
-		else
-			ret = PTR_ERR(di);
+		ret = di ? PTR_ERR(di) : -ENOENT;
 		goto out;
 	}
 
@@ -4278,18 +4413,17 @@
 	 * again is not run concurrently.
 	 */
 	spin_lock(&dest->root_item_lock);
-	root_flags = btrfs_root_flags(&dest->root_item);
-	if (dest->send_in_progress == 0) {
-		btrfs_set_root_flags(&dest->root_item,
-				root_flags | BTRFS_ROOT_SUBVOL_DEAD);
-		spin_unlock(&dest->root_item_lock);
-	} else {
+	if (dest->send_in_progress) {
 		spin_unlock(&dest->root_item_lock);
 		btrfs_warn(fs_info,
 			   "attempt to delete subvolume %llu during send",
 			   dest->root_key.objectid);
 		return -EPERM;
 	}
+	root_flags = btrfs_root_flags(&dest->root_item);
+	btrfs_set_root_flags(&dest->root_item,
+			     root_flags | BTRFS_ROOT_SUBVOL_DEAD);
+	spin_unlock(&dest->root_item_lock);
 
 	down_write(&fs_info->subvol_sem);
 
@@ -4453,31 +4587,6 @@
 	return err;
 }
 
-static int truncate_space_check(struct btrfs_trans_handle *trans,
-				struct btrfs_root *root,
-				u64 bytes_deleted)
-{
-	struct btrfs_fs_info *fs_info = root->fs_info;
-	int ret;
-
-	/*
-	 * This is only used to apply pressure to the enospc system, we don't
-	 * intend to use this reservation at all.
-	 */
-	bytes_deleted = btrfs_csum_bytes_to_leaves(fs_info, bytes_deleted);
-	bytes_deleted *= fs_info->nodesize;
-	ret = btrfs_block_rsv_add(root, &fs_info->trans_block_rsv,
-				  bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
-	if (!ret) {
-		trace_btrfs_space_reservation(fs_info, "transaction",
-					      trans->transid,
-					      bytes_deleted, 1);
-		trans->bytes_reserved += bytes_deleted;
-	}
-	return ret;
-
-}
-
 /*
  * Return this if we need to call truncate_block for the last bit of the
  * truncate.
@@ -4522,7 +4631,6 @@
 	u64 bytes_deleted = 0;
 	bool be_nice = false;
 	bool should_throttle = false;
-	bool should_end = false;
 
 	BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
 
@@ -4553,7 +4661,7 @@
 	/*
 	 * This function is also used to drop the items in the log tree before
 	 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
-	 * it is used to drop the loged items. So we shouldn't kill the delayed
+	 * it is used to drop the logged items. So we shouldn't kill the delayed
 	 * items.
 	 */
 	if (min_type == 0 && root == BTRFS_I(inode)->root)
@@ -4686,7 +4794,7 @@
 
 				btrfs_set_file_extent_ram_bytes(leaf, fi, size);
 				size = btrfs_file_extent_calc_inline_size(size);
-				btrfs_truncate_item(root->fs_info, path, size, 1);
+				btrfs_truncate_item(path, size, 1);
 			} else if (!del_item) {
 				/*
 				 * We have to bail so the last_size is set to
@@ -4725,27 +4833,23 @@
 		if (found_extent &&
 		    (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
 		     root == fs_info->tree_root)) {
+			struct btrfs_ref ref = { 0 };
+
 			btrfs_set_path_blocking(path);
 			bytes_deleted += extent_num_bytes;
-			ret = btrfs_free_extent(trans, root, extent_start,
-						extent_num_bytes, 0,
-						btrfs_header_owner(leaf),
-						ino, extent_offset);
+
+			btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF,
+					extent_start, extent_num_bytes, 0);
+			ref.real_root = root->root_key.objectid;
+			btrfs_init_data_ref(&ref, btrfs_header_owner(leaf),
+					ino, extent_offset);
+			ret = btrfs_free_extent(trans, &ref);
 			if (ret) {
 				btrfs_abort_transaction(trans, ret);
 				break;
 			}
-			if (btrfs_should_throttle_delayed_refs(trans, fs_info))
-				btrfs_async_run_delayed_refs(fs_info,
-					trans->delayed_ref_updates * 2,
-					trans->transid, 0);
 			if (be_nice) {
-				if (truncate_space_check(trans, root,
-							 extent_num_bytes)) {
-					should_end = true;
-				}
-				if (btrfs_should_throttle_delayed_refs(trans,
-								       fs_info))
+				if (btrfs_should_throttle_delayed_refs(trans))
 					should_throttle = true;
 			}
 		}
@@ -4755,7 +4859,7 @@
 
 		if (path->slots[0] == 0 ||
 		    path->slots[0] != pending_del_slot ||
-		    should_throttle || should_end) {
+		    should_throttle) {
 			if (pending_del_nr) {
 				ret = btrfs_del_items(trans, root, path,
 						pending_del_slot,
@@ -4767,23 +4871,24 @@
 				pending_del_nr = 0;
 			}
 			btrfs_release_path(path);
-			if (should_throttle) {
-				unsigned long updates = trans->delayed_ref_updates;
-				if (updates) {
-					trans->delayed_ref_updates = 0;
-					ret = btrfs_run_delayed_refs(trans,
-								   updates * 2);
-					if (ret)
-						break;
-				}
-			}
+
 			/*
-			 * if we failed to refill our space rsv, bail out
-			 * and let the transaction restart
+			 * We can generate a lot of delayed refs, so we need to
+			 * throttle every once and a while and make sure we're
+			 * adding enough space to keep up with the work we are
+			 * generating.  Since we hold a transaction here we
+			 * can't flush, and we don't want to FLUSH_LIMIT because
+			 * we could have generated too many delayed refs to
+			 * actually allocate, so just bail if we're short and
+			 * let the normal reservation dance happen higher up.
 			 */
-			if (should_end) {
-				ret = -EAGAIN;
-				break;
+			if (should_throttle) {
+				ret = btrfs_delayed_refs_rsv_refill(fs_info,
+							BTRFS_RESERVE_NO_FLUSH);
+				if (ret) {
+					ret = -EAGAIN;
+					break;
+				}
 			}
 			goto search_again;
 		} else {
@@ -4809,18 +4914,6 @@
 	}
 
 	btrfs_free_path(path);
-
-	if (be_nice && bytes_deleted > SZ_32M && (ret >= 0 || ret == -EAGAIN)) {
-		unsigned long updates = trans->delayed_ref_updates;
-		int err;
-
-		if (updates) {
-			trans->delayed_ref_updates = 0;
-			err = btrfs_run_delayed_refs(trans, updates * 2);
-			if (err)
-				ret = err;
-		}
-	}
 	return ret;
 }
 
@@ -4871,7 +4964,7 @@
 	if (!page) {
 		btrfs_delalloc_release_space(inode, data_reserved,
 					     block_start, blocksize, true);
-		btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize, true);
+		btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize);
 		ret = -ENOMEM;
 		goto out;
 	}
@@ -4906,12 +4999,11 @@
 	}
 
 	clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end,
-			  EXTENT_DIRTY | EXTENT_DELALLOC |
-			  EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
-			  0, 0, &cached_state);
+			 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
+			 0, 0, &cached_state);
 
 	ret = btrfs_set_extent_delalloc(inode, block_start, block_end, 0,
-					&cached_state, 0);
+					&cached_state);
 	if (ret) {
 		unlock_extent_cached(io_tree, block_start, block_end,
 				     &cached_state);
@@ -4939,7 +5031,7 @@
 	if (ret)
 		btrfs_delalloc_release_space(inode, data_reserved, block_start,
 					     blocksize, true);
-	btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize, (ret != 0));
+	btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize);
 	unlock_page(page);
 	put_page(page);
 out:
@@ -5024,21 +5116,8 @@
 	if (size <= hole_start)
 		return 0;
 
-	while (1) {
-		struct btrfs_ordered_extent *ordered;
-
-		lock_extent_bits(io_tree, hole_start, block_end - 1,
-				 &cached_state);
-		ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), hole_start,
-						     block_end - hole_start);
-		if (!ordered)
-			break;
-		unlock_extent_cached(io_tree, hole_start, block_end - 1,
-				     &cached_state);
-		btrfs_start_ordered_extent(inode, ordered, 1);
-		btrfs_put_ordered_extent(ordered);
-	}
-
+	btrfs_lock_and_flush_ordered_range(io_tree, BTRFS_I(inode), hole_start,
+					   block_end - 1, &cached_state);
 	cur_offset = hole_start;
 	while (1) {
 		em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset,
@@ -5165,7 +5244,7 @@
 
 		truncate_setsize(inode, newsize);
 
-		/* Disable nonlocked read DIO to avoid the end less truncate */
+		/* Disable nonlocked read DIO to avoid the endless truncate */
 		btrfs_inode_block_unlocked_dio(BTRFS_I(inode));
 		inode_dio_wait(inode);
 		btrfs_inode_resume_unlocked_dio(BTRFS_I(inode));
@@ -5243,10 +5322,10 @@
 	truncate_inode_pages_final(&inode->i_data);
 
 	write_lock(&map_tree->lock);
-	while (!RB_EMPTY_ROOT(&map_tree->map)) {
+	while (!RB_EMPTY_ROOT(&map_tree->map.rb_root)) {
 		struct extent_map *em;
 
-		node = rb_first(&map_tree->map);
+		node = rb_first_cached(&map_tree->map);
 		em = rb_entry(node, struct extent_map, rb_node);
 		clear_bit(EXTENT_FLAG_PINNED, &em->flags);
 		clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
@@ -5305,9 +5384,9 @@
 			btrfs_qgroup_free_data(inode, NULL, start, end - start + 1);
 
 		clear_extent_bit(io_tree, start, end,
-				 EXTENT_LOCKED | EXTENT_DIRTY |
-				 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
-				 EXTENT_DEFRAG, 1, 1, &cached_state);
+				 EXTENT_LOCKED | EXTENT_DELALLOC |
+				 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1,
+				 &cached_state);
 
 		cond_resched();
 		spin_lock(&io_tree->lock);
@@ -5316,43 +5395,54 @@
 }
 
 static struct btrfs_trans_handle *evict_refill_and_join(struct btrfs_root *root,
-							struct btrfs_block_rsv *rsv,
-							u64 min_size)
+							struct btrfs_block_rsv *rsv)
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
-	int failures = 0;
+	struct btrfs_trans_handle *trans;
+	u64 delayed_refs_extra = btrfs_calc_insert_metadata_size(fs_info, 1);
+	int ret;
 
-	for (;;) {
-		struct btrfs_trans_handle *trans;
-		int ret;
-
-		ret = btrfs_block_rsv_refill(root, rsv, min_size,
-					     BTRFS_RESERVE_FLUSH_LIMIT);
-
-		if (ret && ++failures > 2) {
-			btrfs_warn(fs_info,
-				   "could not allocate space for a delete; will truncate on mount");
-			return ERR_PTR(-ENOSPC);
-		}
-
-		trans = btrfs_join_transaction(root);
-		if (IS_ERR(trans) || !ret)
-			return trans;
-
+	/*
+	 * Eviction should be taking place at some place safe because of our
+	 * delayed iputs.  However the normal flushing code will run delayed
+	 * iputs, so we cannot use FLUSH_ALL otherwise we'll deadlock.
+	 *
+	 * We reserve the delayed_refs_extra here again because we can't use
+	 * btrfs_start_transaction(root, 0) for the same deadlocky reason as
+	 * above.  We reserve our extra bit here because we generate a ton of
+	 * delayed refs activity by truncating.
+	 *
+	 * If we cannot make our reservation we'll attempt to steal from the
+	 * global reserve, because we really want to be able to free up space.
+	 */
+	ret = btrfs_block_rsv_refill(root, rsv, rsv->size + delayed_refs_extra,
+				     BTRFS_RESERVE_FLUSH_EVICT);
+	if (ret) {
 		/*
 		 * Try to steal from the global reserve if there is space for
 		 * it.
 		 */
-		if (!btrfs_check_space_for_delayed_refs(trans, fs_info) &&
-		    !btrfs_block_rsv_migrate(global_rsv, rsv, min_size, 0))
-			return trans;
-
-		/* If not, commit and try again. */
-		ret = btrfs_commit_transaction(trans);
-		if (ret)
-			return ERR_PTR(ret);
+		if (btrfs_check_space_for_delayed_refs(fs_info) ||
+		    btrfs_block_rsv_migrate(global_rsv, rsv, rsv->size, 0)) {
+			btrfs_warn(fs_info,
+				   "could not allocate space for delete; will truncate on mount");
+			return ERR_PTR(-ENOSPC);
+		}
+		delayed_refs_extra = 0;
 	}
+
+	trans = btrfs_join_transaction(root);
+	if (IS_ERR(trans))
+		return trans;
+
+	if (delayed_refs_extra) {
+		trans->block_rsv = &fs_info->trans_block_rsv;
+		trans->bytes_reserved = delayed_refs_extra;
+		btrfs_block_rsv_migrate(rsv, trans->block_rsv,
+					delayed_refs_extra, 1);
+	}
+	return trans;
 }
 
 void btrfs_evict_inode(struct inode *inode)
@@ -5361,7 +5451,6 @@
 	struct btrfs_trans_handle *trans;
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct btrfs_block_rsv *rsv;
-	u64 min_size;
 	int ret;
 
 	trace_btrfs_inode_evict(inode);
@@ -5371,8 +5460,6 @@
 		return;
 	}
 
-	min_size = btrfs_calc_trunc_metadata_size(fs_info, 1);
-
 	evict_inode_truncate_pages(inode);
 
 	if (inode->i_nlink &&
@@ -5383,9 +5470,6 @@
 
 	if (is_bad_inode(inode))
 		goto no_delete;
-	/* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
-	if (!special_file(inode->i_mode))
-		btrfs_wait_ordered_range(inode, 0, (u64)-1);
 
 	btrfs_free_io_failure_record(BTRFS_I(inode), 0, (u64)-1);
 
@@ -5405,13 +5489,13 @@
 	rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
 	if (!rsv)
 		goto no_delete;
-	rsv->size = min_size;
+	rsv->size = btrfs_calc_metadata_size(fs_info, 1);
 	rsv->failfast = 1;
 
 	btrfs_i_size_write(BTRFS_I(inode), 0);
 
 	while (1) {
-		trans = evict_refill_and_join(root, rsv, min_size);
+		trans = evict_refill_and_join(root, rsv);
 		if (IS_ERR(trans))
 			goto free_rsv;
 
@@ -5436,7 +5520,7 @@
 	 * If it turns out that we are dropping too many of these, we might want
 	 * to add a mechanism for retrying these after a commit.
 	 */
-	trans = evict_refill_and_join(root, rsv, min_size);
+	trans = evict_refill_and_join(root, rsv);
 	if (!IS_ERR(trans)) {
 		trans->block_rsv = rsv;
 		btrfs_orphan_del(trans, BTRFS_I(inode));
@@ -5461,12 +5545,14 @@
 }
 
 /*
- * this returns the key found in the dir entry in the location pointer.
+ * Return the key found in the dir entry in the location pointer, fill @type
+ * with BTRFS_FT_*, and return 0.
+ *
  * If no dir entries were found, returns -ENOENT.
  * If found a corrupted location in dir entry, returns -EUCLEAN.
  */
 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
-			       struct btrfs_key *location)
+			       struct btrfs_key *location, u8 *type)
 {
 	const char *name = dentry->d_name.name;
 	int namelen = dentry->d_name.len;
@@ -5481,12 +5567,8 @@
 
 	di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(BTRFS_I(dir)),
 			name, namelen, 0);
-	if (!di) {
-		ret = -ENOENT;
-		goto out;
-	}
-	if (IS_ERR(di)) {
-		ret = PTR_ERR(di);
+	if (IS_ERR_OR_NULL(di)) {
+		ret = di ? PTR_ERR(di) : -ENOENT;
 		goto out;
 	}
 
@@ -5499,6 +5581,8 @@
 			   __func__, name, btrfs_ino(BTRFS_I(dir)),
 			   location->objectid, location->type, location->offset);
 	}
+	if (!ret)
+		*type = btrfs_dir_type(path->nodes[0], di);
 out:
 	btrfs_free_path(path);
 	return ret;
@@ -5669,8 +5753,9 @@
 /* Get an inode object given its location and corresponding root.
  * Returns in *is_new if the inode was read from disk
  */
-struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
-			 struct btrfs_root *root, int *new)
+struct inode *btrfs_iget_path(struct super_block *s, struct btrfs_key *location,
+			      struct btrfs_root *root, int *new,
+			      struct btrfs_path *path)
 {
 	struct inode *inode;
 
@@ -5681,7 +5766,7 @@
 	if (inode->i_state & I_NEW) {
 		int ret;
 
-		ret = btrfs_read_locked_inode(inode);
+		ret = btrfs_read_locked_inode(inode, path);
 		if (!ret) {
 			inode_tree_add(inode);
 			unlock_new_inode(inode);
@@ -5703,6 +5788,12 @@
 	return inode;
 }
 
+struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
+			 struct btrfs_root *root, int *new)
+{
+	return btrfs_iget_path(s, location, root, new, NULL);
+}
+
 static struct inode *new_simple_dir(struct super_block *s,
 				    struct btrfs_key *key,
 				    struct btrfs_root *root)
@@ -5729,6 +5820,24 @@
 	return inode;
 }
 
+static inline u8 btrfs_inode_type(struct inode *inode)
+{
+	/*
+	 * Compile-time asserts that generic FT_* types still match
+	 * BTRFS_FT_* types
+	 */
+	BUILD_BUG_ON(BTRFS_FT_UNKNOWN != FT_UNKNOWN);
+	BUILD_BUG_ON(BTRFS_FT_REG_FILE != FT_REG_FILE);
+	BUILD_BUG_ON(BTRFS_FT_DIR != FT_DIR);
+	BUILD_BUG_ON(BTRFS_FT_CHRDEV != FT_CHRDEV);
+	BUILD_BUG_ON(BTRFS_FT_BLKDEV != FT_BLKDEV);
+	BUILD_BUG_ON(BTRFS_FT_FIFO != FT_FIFO);
+	BUILD_BUG_ON(BTRFS_FT_SOCK != FT_SOCK);
+	BUILD_BUG_ON(BTRFS_FT_SYMLINK != FT_SYMLINK);
+
+	return fs_umode_to_ftype(inode->i_mode);
+}
+
 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
@@ -5736,18 +5845,31 @@
 	struct btrfs_root *root = BTRFS_I(dir)->root;
 	struct btrfs_root *sub_root = root;
 	struct btrfs_key location;
+	u8 di_type = 0;
 	int index;
 	int ret = 0;
 
 	if (dentry->d_name.len > BTRFS_NAME_LEN)
 		return ERR_PTR(-ENAMETOOLONG);
 
-	ret = btrfs_inode_by_name(dir, dentry, &location);
+	ret = btrfs_inode_by_name(dir, dentry, &location, &di_type);
 	if (ret < 0)
 		return ERR_PTR(ret);
 
 	if (location.type == BTRFS_INODE_ITEM_KEY) {
 		inode = btrfs_iget(dir->i_sb, &location, root, NULL);
+		if (IS_ERR(inode))
+			return inode;
+
+		/* Do extra check against inode mode with di_type */
+		if (btrfs_inode_type(inode) != di_type) {
+			btrfs_crit(fs_info,
+"inode mode mismatch with dir: inode mode=0%o btrfs type=%u dir type=%u",
+				  inode->i_mode, btrfs_inode_type(inode),
+				  di_type);
+			iput(inode);
+			return ERR_PTR(-EUCLEAN);
+		}
 		return inode;
 	}
 
@@ -5800,23 +5922,13 @@
 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
 				   unsigned int flags)
 {
-	struct inode *inode;
+	struct inode *inode = btrfs_lookup_dentry(dir, dentry);
 
-	inode = btrfs_lookup_dentry(dir, dentry);
-	if (IS_ERR(inode)) {
-		if (PTR_ERR(inode) == -ENOENT)
-			inode = NULL;
-		else
-			return ERR_CAST(inode);
-	}
-
+	if (inode == ERR_PTR(-ENOENT))
+		inode = NULL;
 	return d_splice_alias(inode, dentry);
 }
 
-unsigned char btrfs_filetype_table[] = {
-	DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
-};
-
 /*
  * All this infrastructure exists because dir_emit can fault, and we are holding
  * the tree lock when doing readdir.  For now just allocate a buffer and copy
@@ -5955,7 +6067,7 @@
 		name_ptr = (char *)(entry + 1);
 		read_extent_buffer(leaf, name_ptr, (unsigned long)(di + 1),
 				   name_len);
-		put_unaligned(btrfs_filetype_table[btrfs_dir_type(leaf, di)],
+		put_unaligned(fs_ftype_to_dtype(btrfs_dir_type(leaf, di)),
 				&entry->type);
 		btrfs_dir_item_key_to_cpu(leaf, di, &location);
 		put_unaligned(location.objectid, &entry->ino);
@@ -6206,13 +6318,16 @@
 	u32 sizes[2];
 	int nitems = name ? 2 : 1;
 	unsigned long ptr;
+	unsigned int nofs_flag;
 	int ret;
 
 	path = btrfs_alloc_path();
 	if (!path)
 		return ERR_PTR(-ENOMEM);
 
+	nofs_flag = memalloc_nofs_save();
 	inode = new_inode(fs_info->sb);
+	memalloc_nofs_restore(nofs_flag);
 	if (!inode) {
 		btrfs_free_path(path);
 		return ERR_PTR(-ENOMEM);
@@ -6358,11 +6473,6 @@
 	return ERR_PTR(ret);
 }
 
-static inline u8 btrfs_inode_type(struct inode *inode)
-{
-	return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
-}
-
 /*
  * utility function to add 'inode' into 'parent_inode' with
  * a give name and a given sequence number.
@@ -6400,8 +6510,7 @@
 	if (ret)
 		return ret;
 
-	ret = btrfs_insert_dir_item(trans, root, name, name_len,
-				    parent_inode, &key,
+	ret = btrfs_insert_dir_item(trans, name, name_len, parent_inode, &key,
 				    btrfs_inode_type(&inode->vfs_inode), index);
 	if (ret == -EEXIST || ret == -EOVERFLOW)
 		goto fail_dir_item;
@@ -6413,8 +6522,18 @@
 	btrfs_i_size_write(parent_inode, parent_inode->vfs_inode.i_size +
 			   name_len * 2);
 	inode_inc_iversion(&parent_inode->vfs_inode);
-	parent_inode->vfs_inode.i_mtime = parent_inode->vfs_inode.i_ctime =
-		current_time(&parent_inode->vfs_inode);
+	/*
+	 * If we are replaying a log tree, we do not want to update the mtime
+	 * and ctime of the parent directory with the current time, since the
+	 * log replay procedure is responsible for setting them to their correct
+	 * values (the ones it had when the fsync was done).
+	 */
+	if (!test_bit(BTRFS_FS_LOG_RECOVERING, &root->fs_info->flags)) {
+		struct timespec64 now = current_time(&parent_inode->vfs_inode);
+
+		parent_inode->vfs_inode.i_mtime = now;
+		parent_inode->vfs_inode.i_ctime = now;
+	}
 	ret = btrfs_update_inode(trans, root, &parent_inode->vfs_inode);
 	if (ret)
 		btrfs_abort_transaction(trans, ret);
@@ -6427,14 +6546,19 @@
 		err = btrfs_del_root_ref(trans, key.objectid,
 					 root->root_key.objectid, parent_ino,
 					 &local_index, name, name_len);
-
+		if (err)
+			btrfs_abort_transaction(trans, err);
 	} else if (add_backref) {
 		u64 local_index;
 		int err;
 
 		err = btrfs_del_inode_ref(trans, root, name, name_len,
 					  ino, parent_ino, &local_index);
+		if (err)
+			btrfs_abort_transaction(trans, err);
 	}
+
+	/* Return the original error code */
 	return ret;
 }
 
@@ -6594,7 +6718,7 @@
 	int drop_inode = 0;
 
 	/* do not allow sys_link's with other subvols of the same device */
-	if (root->objectid != BTRFS_I(inode)->root->objectid)
+	if (root->root_key.objectid != BTRFS_I(inode)->root->root_key.objectid)
 		return -EXDEV;
 
 	if (inode->i_nlink >= BTRFS_LINK_MAX)
@@ -6673,7 +6797,6 @@
 	struct btrfs_trans_handle *trans;
 	struct btrfs_root *root = BTRFS_I(dir)->root;
 	int err = 0;
-	int drop_on_err = 0;
 	u64 objectid = 0;
 	u64 index = 0;
 
@@ -6699,7 +6822,6 @@
 		goto out_fail;
 	}
 
-	drop_on_err = 1;
 	/* these must be set before we unlock the inode */
 	inode->i_op = &btrfs_dir_inode_operations;
 	inode->i_fop = &btrfs_dir_file_operations;
@@ -6720,7 +6842,6 @@
 		goto out_fail;
 
 	d_instantiate_new(dentry, inode);
-	drop_on_err = 0;
 
 out_fail:
 	btrfs_end_transaction(trans);
@@ -6787,9 +6908,9 @@
  * This also copies inline extents directly into the page.
  */
 struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
-		struct page *page,
-	    size_t pg_offset, u64 start, u64 len,
-		int create)
+				    struct page *page,
+				    size_t pg_offset, u64 start, u64 len,
+				    int create)
 {
 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
 	int ret;
@@ -6797,7 +6918,7 @@
 	u64 extent_start = 0;
 	u64 extent_end = 0;
 	u64 objectid = btrfs_ino(inode);
-	u32 found_type;
+	int extent_type = -1;
 	struct btrfs_path *path = NULL;
 	struct btrfs_root *root = inode->root;
 	struct btrfs_file_extent_item *item;
@@ -6833,26 +6954,26 @@
 	em->len = (u64)-1;
 	em->block_len = (u64)-1;
 
+	path = btrfs_alloc_path();
 	if (!path) {
-		path = btrfs_alloc_path();
-		if (!path) {
-			err = -ENOMEM;
-			goto out;
-		}
-		/*
-		 * Chances are we'll be called again, so go ahead and do
-		 * readahead
-		 */
-		path->reada = READA_FORWARD;
+		err = -ENOMEM;
+		goto out;
 	}
 
+	/* Chances are we'll be called again, so go ahead and do readahead */
+	path->reada = READA_FORWARD;
+
+	/*
+	 * Unless we're going to uncompress the inline extent, no sleep would
+	 * happen.
+	 */
+	path->leave_spinning = 1;
+
 	ret = btrfs_lookup_file_extent(NULL, root, path, objectid, start, 0);
 	if (ret < 0) {
 		err = ret;
 		goto out;
-	}
-
-	if (ret != 0) {
+	} else if (ret > 0) {
 		if (path->slots[0] == 0)
 			goto not_found;
 		path->slots[0]--;
@@ -6861,11 +6982,9 @@
 	leaf = path->nodes[0];
 	item = btrfs_item_ptr(leaf, path->slots[0],
 			      struct btrfs_file_extent_item);
-	/* are we inside the extent that was found? */
 	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
-	found_type = found_key.type;
 	if (found_key.objectid != objectid ||
-	    found_type != BTRFS_EXTENT_DATA_KEY) {
+	    found_key.type != BTRFS_EXTENT_DATA_KEY) {
 		/*
 		 * If we backup past the first extent we want to move forward
 		 * and see if there is an extent in front of us, otherwise we'll
@@ -6876,16 +6995,24 @@
 		goto next;
 	}
 
-	found_type = btrfs_file_extent_type(leaf, item);
+	extent_type = btrfs_file_extent_type(leaf, item);
 	extent_start = found_key.offset;
-	if (found_type == BTRFS_FILE_EXTENT_REG ||
-	    found_type == BTRFS_FILE_EXTENT_PREALLOC) {
+	if (extent_type == BTRFS_FILE_EXTENT_REG ||
+	    extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
+		/* Only regular file could have regular/prealloc extent */
+		if (!S_ISREG(inode->vfs_inode.i_mode)) {
+			ret = -EUCLEAN;
+			btrfs_crit(fs_info,
+		"regular/prealloc extent found for non-regular inode %llu",
+				   btrfs_ino(inode));
+			goto out;
+		}
 		extent_end = extent_start +
 		       btrfs_file_extent_num_bytes(leaf, item);
 
 		trace_btrfs_get_extent_show_fi_regular(inode, leaf, item,
 						       extent_start);
-	} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
+	} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
 		size_t size;
 
 		size = btrfs_file_extent_ram_bytes(leaf, item);
@@ -6904,9 +7031,9 @@
 			if (ret < 0) {
 				err = ret;
 				goto out;
-			}
-			if (ret > 0)
+			} else if (ret > 0) {
 				goto not_found;
+			}
 			leaf = path->nodes[0];
 		}
 		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
@@ -6917,19 +7044,22 @@
 			goto not_found;
 		if (start > found_key.offset)
 			goto next;
+
+		/* New extent overlaps with existing one */
 		em->start = start;
 		em->orig_start = start;
 		em->len = found_key.offset - start;
-		goto not_found_em;
+		em->block_start = EXTENT_MAP_HOLE;
+		goto insert;
 	}
 
 	btrfs_extent_item_to_extent_map(inode, path, item,
 			new_inline, em);
 
-	if (found_type == BTRFS_FILE_EXTENT_REG ||
-	    found_type == BTRFS_FILE_EXTENT_PREALLOC) {
+	if (extent_type == BTRFS_FILE_EXTENT_REG ||
+	    extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
 		goto insert;
-	} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
+	} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
 		unsigned long ptr;
 		char *map;
 		size_t size;
@@ -6948,6 +7078,8 @@
 		em->orig_block_len = em->len;
 		em->orig_start = em->start;
 		ptr = btrfs_file_extent_inline_start(item) + extent_offset;
+
+		btrfs_set_path_blocking(path);
 		if (!PageUptodate(page)) {
 			if (btrfs_file_extent_compression(leaf, item) !=
 			    BTRFS_COMPRESS_NONE) {
@@ -6978,7 +7110,6 @@
 	em->start = start;
 	em->orig_start = start;
 	em->len = len;
-not_found_em:
 	em->block_start = EXTENT_MAP_HOLE;
 insert:
 	btrfs_release_path(path);
@@ -6995,10 +7126,10 @@
 	err = btrfs_add_extent_mapping(fs_info, em_tree, &em, start, len);
 	write_unlock(&em_tree->lock);
 out:
+	btrfs_free_path(path);
 
 	trace_btrfs_get_extent(root, inode, em);
 
-	btrfs_free_path(path);
 	if (err) {
 		free_extent_map(em);
 		return ERR_PTR(err);
@@ -7008,19 +7139,17 @@
 }
 
 struct extent_map *btrfs_get_extent_fiemap(struct btrfs_inode *inode,
-		struct page *page,
-		size_t pg_offset, u64 start, u64 len,
-		int create)
+					   u64 start, u64 len)
 {
 	struct extent_map *em;
 	struct extent_map *hole_em = NULL;
-	u64 range_start = start;
+	u64 delalloc_start = start;
 	u64 end;
-	u64 found;
-	u64 found_end;
+	u64 delalloc_len;
+	u64 delalloc_end;
 	int err = 0;
 
-	em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
+	em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
 	if (IS_ERR(em))
 		return em;
 	/*
@@ -7045,80 +7174,84 @@
 	em = NULL;
 
 	/* ok, we didn't find anything, lets look for delalloc */
-	found = count_range_bits(&inode->io_tree, &range_start,
+	delalloc_len = count_range_bits(&inode->io_tree, &delalloc_start,
 				 end, len, EXTENT_DELALLOC, 1);
-	found_end = range_start + found;
-	if (found_end < range_start)
-		found_end = (u64)-1;
+	delalloc_end = delalloc_start + delalloc_len;
+	if (delalloc_end < delalloc_start)
+		delalloc_end = (u64)-1;
 
 	/*
-	 * we didn't find anything useful, return
-	 * the original results from get_extent()
+	 * We didn't find anything useful, return the original results from
+	 * get_extent()
 	 */
-	if (range_start > end || found_end <= start) {
+	if (delalloc_start > end || delalloc_end <= start) {
 		em = hole_em;
 		hole_em = NULL;
 		goto out;
 	}
 
-	/* adjust the range_start to make sure it doesn't
-	 * go backwards from the start they passed in
+	/*
+	 * Adjust the delalloc_start to make sure it doesn't go backwards from
+	 * the start they passed in
 	 */
-	range_start = max(start, range_start);
-	found = found_end - range_start;
+	delalloc_start = max(start, delalloc_start);
+	delalloc_len = delalloc_end - delalloc_start;
 
-	if (found > 0) {
-		u64 hole_start = start;
-		u64 hole_len = len;
+	if (delalloc_len > 0) {
+		u64 hole_start;
+		u64 hole_len;
+		const u64 hole_end = extent_map_end(hole_em);
 
 		em = alloc_extent_map();
 		if (!em) {
 			err = -ENOMEM;
 			goto out;
 		}
-		/*
-		 * when btrfs_get_extent can't find anything it
-		 * returns one huge hole
-		 *
-		 * make sure what it found really fits our range, and
-		 * adjust to make sure it is based on the start from
-		 * the caller
-		 */
-		if (hole_em) {
-			u64 calc_end = extent_map_end(hole_em);
-
-			if (calc_end <= start || (hole_em->start > end)) {
-				free_extent_map(hole_em);
-				hole_em = NULL;
-			} else {
-				hole_start = max(hole_em->start, start);
-				hole_len = calc_end - hole_start;
-			}
-		}
 		em->bdev = NULL;
-		if (hole_em && range_start > hole_start) {
-			/* our hole starts before our delalloc, so we
-			 * have to return just the parts of the hole
-			 * that go until  the delalloc starts
+
+		ASSERT(hole_em);
+		/*
+		 * When btrfs_get_extent can't find anything it returns one
+		 * huge hole
+		 *
+		 * Make sure what it found really fits our range, and adjust to
+		 * make sure it is based on the start from the caller
+		 */
+		if (hole_end <= start || hole_em->start > end) {
+		       free_extent_map(hole_em);
+		       hole_em = NULL;
+		} else {
+		       hole_start = max(hole_em->start, start);
+		       hole_len = hole_end - hole_start;
+		}
+
+		if (hole_em && delalloc_start > hole_start) {
+			/*
+			 * Our hole starts before our delalloc, so we have to
+			 * return just the parts of the hole that go until the
+			 * delalloc starts
 			 */
-			em->len = min(hole_len,
-				      range_start - hole_start);
+			em->len = min(hole_len, delalloc_start - hole_start);
 			em->start = hole_start;
 			em->orig_start = hole_start;
 			/*
-			 * don't adjust block start at all,
-			 * it is fixed at EXTENT_MAP_HOLE
+			 * Don't adjust block start at all, it is fixed at
+			 * EXTENT_MAP_HOLE
 			 */
 			em->block_start = hole_em->block_start;
 			em->block_len = hole_len;
 			if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
 				set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
 		} else {
-			em->start = range_start;
-			em->len = found;
-			em->orig_start = range_start;
+			/*
+			 * Hole is out of passed range or it starts after
+			 * delalloc range
+			 */
+			em->start = delalloc_start;
+			em->len = delalloc_len;
+			em->orig_start = delalloc_start;
 			em->block_start = EXTENT_MAP_DELALLOC;
-			em->block_len = found;
+			em->block_len = delalloc_len;
 		}
 	} else {
 		return hole_em;
@@ -7614,12 +7747,9 @@
 	u64 start = iblock << inode->i_blkbits;
 	u64 lockstart, lockend;
 	u64 len = bh_result->b_size;
-	int unlock_bits = EXTENT_LOCKED;
 	int ret = 0;
 
-	if (create)
-		unlock_bits |= EXTENT_DIRTY;
-	else
+	if (!create)
 		len = min_t(u64, len, fs_info->sectorsize);
 
 	lockstart = start;
@@ -7678,9 +7808,8 @@
 		if (ret < 0)
 			goto unlock_err;
 
-		/* clear and unlock the entire range */
-		clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
-				 unlock_bits, 1, 0, &cached_state);
+		unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
+				     lockend, &cached_state);
 	} else {
 		ret = btrfs_get_blocks_direct_read(em, bh_result, inode,
 						   start, len);
@@ -7696,9 +7825,8 @@
 		 */
 		lockstart = start + bh_result->b_size;
 		if (lockstart < lockend) {
-			clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
-					 lockend, unlock_bits, 1, 0,
-					 &cached_state);
+			unlock_extent_cached(&BTRFS_I(inode)->io_tree,
+					     lockstart, lockend, &cached_state);
 		} else {
 			free_extent_state(cached_state);
 		}
@@ -7709,8 +7837,8 @@
 	return 0;
 
 unlock_err:
-	clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
-			 unlock_bits, 1, 0, &cached_state);
+	unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
+			     &cached_state);
 err:
 	if (dio_data)
 		current->journal_info = dio_data;
@@ -7838,7 +7966,7 @@
 	struct inode *inode = done->inode;
 	struct bio_vec *bvec;
 	struct extent_io_tree *io_tree, *failure_tree;
-	int i;
+	struct bvec_iter_all iter_all;
 
 	if (bio->bi_status)
 		goto end;
@@ -7850,7 +7978,7 @@
 
 	done->uptodate = 1;
 	ASSERT(!bio_flagged(bio, BIO_CLONED));
-	bio_for_each_segment_all(bvec, bio, i)
+	bio_for_each_segment_all(bvec, bio, iter_all)
 		clean_io_failure(BTRFS_I(inode)->root->fs_info, failure_tree,
 				 io_tree, done->start, bvec->bv_page,
 				 btrfs_ino(BTRFS_I(inode)), 0);
@@ -7928,7 +8056,8 @@
 	struct bio_vec *bvec;
 	int uptodate;
 	int ret;
-	int i;
+	int i = 0;
+	struct bvec_iter_all iter_all;
 
 	if (bio->bi_status)
 		goto end;
@@ -7942,7 +8071,7 @@
 	failure_tree = &BTRFS_I(inode)->io_failure_tree;
 
 	ASSERT(!bio_flagged(bio, BIO_CLONED));
-	bio_for_each_segment_all(bvec, bio, i) {
+	bio_for_each_segment_all(bvec, bio, iter_all) {
 		ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page,
 					     bvec->bv_offset, done->start,
 					     bvec->bv_len);
@@ -7954,6 +8083,7 @@
 					 bvec->bv_offset);
 		else
 			uptodate = 0;
+		i++;
 	}
 
 	done->uptodate = uptodate;
@@ -8070,9 +8200,7 @@
 
 	dio_bio->bi_status = err;
 	dio_end_io(dio_bio);
-
-	if (io_bio->end_io)
-		io_bio->end_io(io_bio, blk_status_to_errno(err));
+	btrfs_io_bio_free_csum(io_bio);
 	bio_put(bio);
 }
 
@@ -8115,7 +8243,7 @@
 			return;
 		/*
 		 * Our bio might span multiple ordered extents. In this case
-		 * we keep goin until we have accounted the whole dio.
+		 * we keep going until we have accounted the whole dio.
 		 */
 		if (ordered_offset < offset + bytes) {
 			ordered_bytes = offset + bytes - ordered_offset;
@@ -8274,22 +8402,21 @@
 	struct bio *orig_bio = dip->orig_bio;
 	u64 start_sector = orig_bio->bi_iter.bi_sector;
 	u64 file_offset = dip->logical_offset;
-	u64 map_length;
 	int async_submit = 0;
 	u64 submit_len;
 	int clone_offset = 0;
 	int clone_len;
 	int ret;
 	blk_status_t status;
+	struct btrfs_io_geometry geom;
 
-	map_length = orig_bio->bi_iter.bi_size;
-	submit_len = map_length;
-	ret = btrfs_map_block(fs_info, btrfs_op(orig_bio), start_sector << 9,
-			      &map_length, NULL, 0);
+	submit_len = orig_bio->bi_iter.bi_size;
+	ret = btrfs_get_io_geometry(fs_info, btrfs_op(orig_bio),
+				    start_sector << 9, submit_len, &geom);
 	if (ret)
 		return -EIO;
 
-	if (map_length >= submit_len) {
+	if (geom.len >= submit_len) {
 		bio = orig_bio;
 		dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
 		goto submit;
@@ -8302,10 +8429,10 @@
 		async_submit = 1;
 
 	/* bio split */
-	ASSERT(map_length <= INT_MAX);
+	ASSERT(geom.len <= INT_MAX);
 	atomic_inc(&dip->pending_bios);
 	do {
-		clone_len = min_t(int, submit_len, map_length);
+		clone_len = min_t(int, submit_len, geom.len);
 
 		/*
 		 * This will never fail as it's passing GPF_NOFS and
@@ -8342,9 +8469,8 @@
 		start_sector += clone_len >> 9;
 		file_offset += clone_len;
 
-		map_length = submit_len;
-		ret = btrfs_map_block(fs_info, btrfs_op(orig_bio),
-				      start_sector << 9, &map_length, NULL, 0);
+		ret = btrfs_get_io_geometry(fs_info, btrfs_op(orig_bio),
+				      start_sector << 9, submit_len, &geom);
 		if (ret)
 			goto out_err;
 	} while (submit_len > 0);
@@ -8425,8 +8551,7 @@
 	if (!ret)
 		return;
 
-	if (io_bio->end_io)
-		io_bio->end_io(io_bio, ret);
+	btrfs_io_bio_free_csum(io_bio);
 
 free_ordered:
 	/*
@@ -8597,7 +8722,7 @@
 		} else if (ret >= 0 && (size_t)ret < count)
 			btrfs_delalloc_release_space(inode, data_reserved,
 					offset, count - (size_t)ret, true);
-		btrfs_delalloc_release_extents(BTRFS_I(inode), count, false);
+		btrfs_delalloc_release_extents(BTRFS_I(inode), count);
 	}
 out:
 	if (wakeup)
@@ -8728,8 +8853,7 @@
 		 */
 		if (!inode_evicting)
 			clear_extent_bit(tree, start, end,
-					 EXTENT_DIRTY | EXTENT_DELALLOC |
-					 EXTENT_DELALLOC_NEW |
+					 EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
 					 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
 					 EXTENT_DEFRAG, 1, 0, &cached_state);
 		/*
@@ -8784,8 +8908,7 @@
 	if (PageDirty(page))
 		btrfs_qgroup_free_data(inode, NULL, page_start, PAGE_SIZE);
 	if (!inode_evicting) {
-		clear_extent_bit(tree, page_start, page_end,
-				 EXTENT_LOCKED | EXTENT_DIRTY |
+		clear_extent_bit(tree, page_start, page_end, EXTENT_LOCKED |
 				 EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
 				 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1,
 				 &cached_state);
@@ -8913,12 +9036,11 @@
 	 * reserve data&meta space before lock_page() (see above comments).
 	 */
 	clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
-			  EXTENT_DIRTY | EXTENT_DELALLOC |
-			  EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
-			  0, 0, &cached_state);
+			  EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
+			  EXTENT_DEFRAG, 0, 0, &cached_state);
 
 	ret2 = btrfs_set_extent_delalloc(inode, page_start, end, 0,
-					&cached_state, 0);
+					&cached_state);
 	if (ret2) {
 		unlock_extent_cached(io_tree, page_start, page_end,
 				     &cached_state);
@@ -8929,7 +9051,7 @@
 
 	/* page is wholly or partially inside EOF */
 	if (page_start + PAGE_SIZE > size)
-		zero_start = size & ~PAGE_MASK;
+		zero_start = offset_in_page(size);
 	else
 		zero_start = PAGE_SIZE;
 
@@ -8950,7 +9072,7 @@
 	unlock_extent_cached(io_tree, page_start, page_end, &cached_state);
 
 	if (!ret2) {
-		btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE, true);
+		btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
 		sb_end_pagefault(inode->i_sb);
 		extent_changeset_free(data_reserved);
 		return VM_FAULT_LOCKED;
@@ -8959,7 +9081,7 @@
 out_unlock:
 	unlock_page(page);
 out:
-	btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE, (ret != 0));
+	btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
 	btrfs_delalloc_release_space(inode, data_reserved, page_start,
 				     reserved_space, (ret != 0));
 out_noreserve:
@@ -8976,7 +9098,7 @@
 	int ret;
 	struct btrfs_trans_handle *trans;
 	u64 mask = fs_info->sectorsize - 1;
-	u64 min_size = btrfs_calc_trunc_metadata_size(fs_info, 1);
+	u64 min_size = btrfs_calc_metadata_size(fs_info, 1);
 
 	if (!skip_writeback) {
 		ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
@@ -9031,7 +9153,7 @@
 
 	/* Migrate the slack space for the truncate to our reserve */
 	ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
-				      min_size, 0);
+				      min_size, false);
 	BUG_ON(ret);
 
 	/*
@@ -9068,7 +9190,7 @@
 
 		btrfs_block_rsv_release(fs_info, rsv, -1);
 		ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
-					      rsv, min_size, 0);
+					      rsv, min_size, false);
 		BUG_ON(ret);	/* shouldn't happen */
 		trans->block_rsv = rsv;
 	}
@@ -9192,10 +9314,11 @@
 
 	inode = &ei->vfs_inode;
 	extent_map_tree_init(&ei->extent_tree);
-	extent_io_tree_init(&ei->io_tree, inode);
-	extent_io_tree_init(&ei->io_failure_tree, inode);
-	ei->io_tree.track_uptodate = 1;
-	ei->io_failure_tree.track_uptodate = 1;
+	extent_io_tree_init(fs_info, &ei->io_tree, IO_TREE_INODE_IO, inode);
+	extent_io_tree_init(fs_info, &ei->io_failure_tree,
+			    IO_TREE_INODE_IO_FAILURE, inode);
+	ei->io_tree.track_uptodate = true;
+	ei->io_failure_tree.track_uptodate = true;
 	atomic_set(&ei->sync_writers, 0);
 	mutex_init(&ei->log_mutex);
 	mutex_init(&ei->delalloc_mutex);
@@ -9216,9 +9339,8 @@
 }
 #endif
 
-static void btrfs_i_callback(struct rcu_head *head)
+void btrfs_free_inode(struct inode *inode)
 {
-	struct inode *inode = container_of(head, struct inode, i_rcu);
 	kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
 }
 
@@ -9244,7 +9366,7 @@
 	 * created.
 	 */
 	if (!root)
-		goto free;
+		return;
 
 	while (1) {
 		ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
@@ -9262,8 +9384,6 @@
 	btrfs_qgroup_check_reserved_leak(inode);
 	inode_tree_del(inode);
 	btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0);
-free:
-	call_rcu(&inode->i_rcu, btrfs_i_callback);
 }
 
 int btrfs_drop_inode(struct inode *inode)
@@ -9298,6 +9418,7 @@
 	kmem_cache_destroy(btrfs_trans_handle_cachep);
 	kmem_cache_destroy(btrfs_path_cachep);
 	kmem_cache_destroy(btrfs_free_space_cachep);
+	kmem_cache_destroy(btrfs_free_space_bitmap_cachep);
 }
 
 int __init btrfs_init_cachep(void)
@@ -9327,6 +9448,12 @@
 	if (!btrfs_free_space_cachep)
 		goto fail;
 
+	btrfs_free_space_bitmap_cachep = kmem_cache_create("btrfs_free_space_bitmap",
+							PAGE_SIZE, PAGE_SIZE,
+							SLAB_RED_ZONE, NULL);
+	if (!btrfs_free_space_bitmap_cachep)
+		goto fail;
+
 	return 0;
 fail:
 	btrfs_destroy_cachep();
@@ -9440,7 +9567,7 @@
 	/* Reference for the source. */
 	if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
 		/* force full log commit if subvolume involved. */
-		btrfs_set_log_full_commit(fs_info, trans);
+		btrfs_set_log_full_commit(trans);
 	} else {
 		btrfs_pin_log_trans(root);
 		root_log_pinned = true;
@@ -9457,7 +9584,7 @@
 	/* And now for the dest. */
 	if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
 		/* force full log commit if subvolume involved. */
-		btrfs_set_log_full_commit(fs_info, trans);
+		btrfs_set_log_full_commit(trans);
 	} else {
 		btrfs_pin_log_trans(dest);
 		dest_log_pinned = true;
@@ -9593,7 +9720,7 @@
 		    btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
 		    (new_inode &&
 		     btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
-			btrfs_set_log_full_commit(fs_info, trans);
+			btrfs_set_log_full_commit(trans);
 
 		if (root_log_pinned) {
 			btrfs_end_log_trans(root);
@@ -9617,6 +9744,18 @@
 			commit_transaction = true;
 	}
 	if (commit_transaction) {
+		/*
+		 * We may have set commit_transaction when logging the new name
+		 * in the destination root, in which case we left the source
+		 * root context in the list of log contextes. So make sure we
+		 * remove it to avoid invalid memory accesses, since the context
+		 * was allocated in our stack frame.
+		 */
+		if (sync_log_root) {
+			mutex_lock(&root->log_mutex);
+			list_del_init(&ctx_root.list);
+			mutex_unlock(&root->log_mutex);
+		}
 		ret = btrfs_commit_transaction(trans);
 	} else {
 		int ret2;
@@ -9630,6 +9769,9 @@
 	if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
 		up_read(&fs_info->subvol_sem);
 
+	ASSERT(list_empty(&ctx_root.list));
+	ASSERT(list_empty(&ctx_dest.list));
+
 	return ret;
 }
 
@@ -9779,7 +9921,7 @@
 	BTRFS_I(old_inode)->dir_index = 0ULL;
 	if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
 		/* force full log commit if subvolume involved. */
-		btrfs_set_log_full_commit(fs_info, trans);
+		btrfs_set_log_full_commit(trans);
 	} else {
 		btrfs_pin_log_trans(root);
 		log_pinned = true;
@@ -9900,7 +10042,7 @@
 		    btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
 		    (new_inode &&
 		     btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
-			btrfs_set_log_full_commit(fs_info, trans);
+			btrfs_set_log_full_commit(trans);
 
 		btrfs_end_log_trans(root);
 		log_pinned = false;
@@ -9974,7 +10116,6 @@
 	init_completion(&work->completion);
 	INIT_LIST_HEAD(&work->list);
 	work->inode = inode;
-	WARN_ON_ONCE(!inode);
 	btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
 			btrfs_run_delalloc_work, NULL, NULL);
 
@@ -9985,7 +10126,7 @@
  * some fairly slow code that needs optimization. This walks the list
  * of all the inodes with pending delalloc and forces them to disk.
  */
-static int start_delalloc_inodes(struct btrfs_root *root, int nr)
+static int start_delalloc_inodes(struct btrfs_root *root, int nr, bool snapshot)
 {
 	struct btrfs_inode *binode;
 	struct inode *inode;
@@ -10013,6 +10154,9 @@
 		}
 		spin_unlock(&root->delalloc_lock);
 
+		if (snapshot)
+			set_bit(BTRFS_INODE_SNAPSHOT_FLUSH,
+				&binode->runtime_flags);
 		work = btrfs_alloc_delalloc_work(inode);
 		if (!work) {
 			iput(inode);
@@ -10046,7 +10190,7 @@
 	return ret;
 }
 
-int btrfs_start_delalloc_inodes(struct btrfs_root *root)
+int btrfs_start_delalloc_snapshot(struct btrfs_root *root)
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	int ret;
@@ -10054,7 +10198,7 @@
 	if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
 		return -EROFS;
 
-	ret = start_delalloc_inodes(root, -1);
+	ret = start_delalloc_inodes(root, -1, true);
 	if (ret > 0)
 		ret = 0;
 	return ret;
@@ -10083,7 +10227,7 @@
 			       &fs_info->delalloc_roots);
 		spin_unlock(&fs_info->delalloc_root_lock);
 
-		ret = start_delalloc_inodes(root, nr);
+		ret = start_delalloc_inodes(root, nr, false);
 		btrfs_put_fs_root(root);
 		if (ret < 0)
 			goto out;
@@ -10201,7 +10345,6 @@
 
 	inode->i_op = &btrfs_symlink_inode_operations;
 	inode_nohighmem(inode);
-	inode->i_mapping->a_ops = &btrfs_symlink_aops;
 	inode_set_bytes(inode, name_len);
 	btrfs_i_size_write(BTRFS_I(inode), name_len);
 	err = btrfs_update_inode(trans, root, inode);
@@ -10462,26 +10605,6 @@
 	return ret;
 }
 
-__attribute__((const))
-static int btrfs_readpage_io_failed_hook(struct page *page, int failed_mirror)
-{
-	return -EAGAIN;
-}
-
-static void btrfs_check_extent_io_range(void *private_data, const char *caller,
-					u64 start, u64 end)
-{
-	struct inode *inode = private_data;
-	u64 isize;
-
-	isize = i_size_read(inode);
-	if (end >= PAGE_SIZE && (end % 2) == 0 && end != isize - 1) {
-		btrfs_debug_rl(BTRFS_I(inode)->root->fs_info,
-		    "%s: ino %llu isize %llu odd range [%llu,%llu]",
-			caller, btrfs_ino(BTRFS_I(inode)), isize, start, end);
-	}
-}
-
 void btrfs_set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
 {
 	struct inode *inode = tree->private_data;
@@ -10498,6 +10621,343 @@
 	}
 }
 
+#ifdef CONFIG_SWAP
+/*
+ * Add an entry indicating a block group or device which is pinned by a
+ * swapfile. Returns 0 on success, 1 if there is already an entry for it, or a
+ * negative errno on failure.
+ */
+static int btrfs_add_swapfile_pin(struct inode *inode, void *ptr,
+				  bool is_block_group)
+{
+	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
+	struct btrfs_swapfile_pin *sp, *entry;
+	struct rb_node **p;
+	struct rb_node *parent = NULL;
+
+	sp = kmalloc(sizeof(*sp), GFP_NOFS);
+	if (!sp)
+		return -ENOMEM;
+	sp->ptr = ptr;
+	sp->inode = inode;
+	sp->is_block_group = is_block_group;
+
+	spin_lock(&fs_info->swapfile_pins_lock);
+	p = &fs_info->swapfile_pins.rb_node;
+	while (*p) {
+		parent = *p;
+		entry = rb_entry(parent, struct btrfs_swapfile_pin, node);
+		if (sp->ptr < entry->ptr ||
+		    (sp->ptr == entry->ptr && sp->inode < entry->inode)) {
+			p = &(*p)->rb_left;
+		} else if (sp->ptr > entry->ptr ||
+			   (sp->ptr == entry->ptr && sp->inode > entry->inode)) {
+			p = &(*p)->rb_right;
+		} else {
+			spin_unlock(&fs_info->swapfile_pins_lock);
+			kfree(sp);
+			return 1;
+		}
+	}
+	rb_link_node(&sp->node, parent, p);
+	rb_insert_color(&sp->node, &fs_info->swapfile_pins);
+	spin_unlock(&fs_info->swapfile_pins_lock);
+	return 0;
+}
+
+/* Free all of the entries pinned by this swapfile. */
+static void btrfs_free_swapfile_pins(struct inode *inode)
+{
+	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
+	struct btrfs_swapfile_pin *sp;
+	struct rb_node *node, *next;
+
+	spin_lock(&fs_info->swapfile_pins_lock);
+	node = rb_first(&fs_info->swapfile_pins);
+	while (node) {
+		next = rb_next(node);
+		sp = rb_entry(node, struct btrfs_swapfile_pin, node);
+		if (sp->inode == inode) {
+			rb_erase(&sp->node, &fs_info->swapfile_pins);
+			if (sp->is_block_group)
+				btrfs_put_block_group(sp->ptr);
+			kfree(sp);
+		}
+		node = next;
+	}
+	spin_unlock(&fs_info->swapfile_pins_lock);
+}
+
+struct btrfs_swap_info {
+	u64 start;
+	u64 block_start;
+	u64 block_len;
+	u64 lowest_ppage;
+	u64 highest_ppage;
+	unsigned long nr_pages;
+	int nr_extents;
+};
+
+static int btrfs_add_swap_extent(struct swap_info_struct *sis,
+				 struct btrfs_swap_info *bsi)
+{
+	unsigned long nr_pages;
+	u64 first_ppage, first_ppage_reported, next_ppage;
+	int ret;
+
+	first_ppage = ALIGN(bsi->block_start, PAGE_SIZE) >> PAGE_SHIFT;
+	next_ppage = ALIGN_DOWN(bsi->block_start + bsi->block_len,
+				PAGE_SIZE) >> PAGE_SHIFT;
+
+	if (first_ppage >= next_ppage)
+		return 0;
+	nr_pages = next_ppage - first_ppage;
+
+	first_ppage_reported = first_ppage;
+	if (bsi->start == 0)
+		first_ppage_reported++;
+	if (bsi->lowest_ppage > first_ppage_reported)
+		bsi->lowest_ppage = first_ppage_reported;
+	if (bsi->highest_ppage < (next_ppage - 1))
+		bsi->highest_ppage = next_ppage - 1;
+
+	ret = add_swap_extent(sis, bsi->nr_pages, nr_pages, first_ppage);
+	if (ret < 0)
+		return ret;
+	bsi->nr_extents += ret;
+	bsi->nr_pages += nr_pages;
+	return 0;
+}
+
+static void btrfs_swap_deactivate(struct file *file)
+{
+	struct inode *inode = file_inode(file);
+
+	btrfs_free_swapfile_pins(inode);
+	atomic_dec(&BTRFS_I(inode)->root->nr_swapfiles);
+}
+
+static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file,
+			       sector_t *span)
+{
+	struct inode *inode = file_inode(file);
+	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
+	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+	struct extent_state *cached_state = NULL;
+	struct extent_map *em = NULL;
+	struct btrfs_device *device = NULL;
+	struct btrfs_swap_info bsi = {
+		.lowest_ppage = (sector_t)-1ULL,
+	};
+	int ret = 0;
+	u64 isize;
+	u64 start;
+
+	/*
+	 * If the swap file was just created, make sure delalloc is done. If the
+	 * file changes again after this, the user is doing something stupid and
+	 * we don't really care.
+	 */
+	ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
+	if (ret)
+		return ret;
+
+	/*
+	 * The inode is locked, so these flags won't change after we check them.
+	 */
+	if (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS) {
+		btrfs_warn(fs_info, "swapfile must not be compressed");
+		return -EINVAL;
+	}
+	if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW)) {
+		btrfs_warn(fs_info, "swapfile must not be copy-on-write");
+		return -EINVAL;
+	}
+	if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
+		btrfs_warn(fs_info, "swapfile must not be checksummed");
+		return -EINVAL;
+	}
+
+	/*
+	 * Balance or device remove/replace/resize can move stuff around from
+	 * under us. The EXCL_OP flag makes sure they aren't running/won't run
+	 * concurrently while we are mapping the swap extents, and
+	 * fs_info->swapfile_pins prevents them from running while the swap file
+	 * is active and moving the extents. Note that this also prevents a
+	 * concurrent device add which isn't actually necessary, but it's not
+	 * really worth the trouble to allow it.
+	 */
+	if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
+		btrfs_warn(fs_info,
+	   "cannot activate swapfile while exclusive operation is running");
+		return -EBUSY;
+	}
+	/*
+	 * Snapshots can create extents which require COW even if NODATACOW is
+	 * set. We use this counter to prevent snapshots. We must increment it
+	 * before walking the extents because we don't want a concurrent
+	 * snapshot to run after we've already checked the extents.
+	 */
+	atomic_inc(&BTRFS_I(inode)->root->nr_swapfiles);
+
+	isize = ALIGN_DOWN(inode->i_size, fs_info->sectorsize);
+
+	lock_extent_bits(io_tree, 0, isize - 1, &cached_state);
+	start = 0;
+	while (start < isize) {
+		u64 logical_block_start, physical_block_start;
+		struct btrfs_block_group_cache *bg;
+		u64 len = isize - start;
+
+		em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
+		if (IS_ERR(em)) {
+			ret = PTR_ERR(em);
+			goto out;
+		}
+
+		if (em->block_start == EXTENT_MAP_HOLE) {
+			btrfs_warn(fs_info, "swapfile must not have holes");
+			ret = -EINVAL;
+			goto out;
+		}
+		if (em->block_start == EXTENT_MAP_INLINE) {
+			/*
+			 * It's unlikely we'll ever actually find ourselves
+			 * here, as a file small enough to fit inline won't be
+			 * big enough to store more than the swap header, but in
+			 * case something changes in the future, let's catch it
+			 * here rather than later.
+			 */
+			btrfs_warn(fs_info, "swapfile must not be inline");
+			ret = -EINVAL;
+			goto out;
+		}
+		if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
+			btrfs_warn(fs_info, "swapfile must not be compressed");
+			ret = -EINVAL;
+			goto out;
+		}
+
+		logical_block_start = em->block_start + (start - em->start);
+		len = min(len, em->len - (start - em->start));
+		free_extent_map(em);
+		em = NULL;
+
+		ret = can_nocow_extent(inode, start, &len, NULL, NULL, NULL);
+		if (ret < 0) {
+			goto out;
+		} else if (ret) {
+			ret = 0;
+		} else {
+			btrfs_warn(fs_info,
+				   "swapfile must not be copy-on-write");
+			ret = -EINVAL;
+			goto out;
+		}
+
+		em = btrfs_get_chunk_map(fs_info, logical_block_start, len);
+		if (IS_ERR(em)) {
+			ret = PTR_ERR(em);
+			goto out;
+		}
+
+		if (em->map_lookup->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
+			btrfs_warn(fs_info,
+				   "swapfile must have single data profile");
+			ret = -EINVAL;
+			goto out;
+		}
+
+		if (device == NULL) {
+			device = em->map_lookup->stripes[0].dev;
+			ret = btrfs_add_swapfile_pin(inode, device, false);
+			if (ret == 1)
+				ret = 0;
+			else if (ret)
+				goto out;
+		} else if (device != em->map_lookup->stripes[0].dev) {
+			btrfs_warn(fs_info, "swapfile must be on one device");
+			ret = -EINVAL;
+			goto out;
+		}
+
+		physical_block_start = (em->map_lookup->stripes[0].physical +
+					(logical_block_start - em->start));
+		len = min(len, em->len - (logical_block_start - em->start));
+		free_extent_map(em);
+		em = NULL;
+
+		bg = btrfs_lookup_block_group(fs_info, logical_block_start);
+		if (!bg) {
+			btrfs_warn(fs_info,
+			   "could not find block group containing swapfile");
+			ret = -EINVAL;
+			goto out;
+		}
+
+		ret = btrfs_add_swapfile_pin(inode, bg, true);
+		if (ret) {
+			btrfs_put_block_group(bg);
+			if (ret == 1)
+				ret = 0;
+			else
+				goto out;
+		}
+
+		if (bsi.block_len &&
+		    bsi.block_start + bsi.block_len == physical_block_start) {
+			bsi.block_len += len;
+		} else {
+			if (bsi.block_len) {
+				ret = btrfs_add_swap_extent(sis, &bsi);
+				if (ret)
+					goto out;
+			}
+			bsi.start = start;
+			bsi.block_start = physical_block_start;
+			bsi.block_len = len;
+		}
+
+		start += len;
+	}
+
+	if (bsi.block_len)
+		ret = btrfs_add_swap_extent(sis, &bsi);
+
+out:
+	if (!IS_ERR_OR_NULL(em))
+		free_extent_map(em);
+
+	unlock_extent_cached(io_tree, 0, isize - 1, &cached_state);
+
+	if (ret)
+		btrfs_swap_deactivate(file);
+
+	clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
+
+	if (ret)
+		return ret;
+
+	if (device)
+		sis->bdev = device->bdev;
+	*span = bsi.highest_ppage - bsi.lowest_ppage + 1;
+	sis->max = bsi.nr_pages;
+	sis->pages = bsi.nr_pages - 1;
+	sis->highest_bit = bsi.nr_pages - 1;
+	return bsi.nr_extents;
+}
+#else
+static void btrfs_swap_deactivate(struct file *file)
+{
+}
+
+static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file,
+			       sector_t *span)
+{
+	return -EOPNOTSUPP;
+}
+#endif
+
 static const struct inode_operations btrfs_dir_inode_operations = {
 	.getattr	= btrfs_getattr,
 	.lookup		= btrfs_lookup,
@@ -10540,17 +11000,6 @@
 	/* mandatory callbacks */
 	.submit_bio_hook = btrfs_submit_bio_hook,
 	.readpage_end_io_hook = btrfs_readpage_end_io_hook,
-	.readpage_io_failed_hook = btrfs_readpage_io_failed_hook,
-
-	/* optional callbacks */
-	.fill_delalloc = run_delalloc_range,
-	.writepage_end_io_hook = btrfs_writepage_end_io_hook,
-	.writepage_start_hook = btrfs_writepage_start_hook,
-	.set_bit_hook = btrfs_set_bit_hook,
-	.clear_bit_hook = btrfs_clear_bit_hook,
-	.merge_extent_hook = btrfs_merge_extent_hook,
-	.split_extent_hook = btrfs_split_extent_hook,
-	.check_extent_io_range = btrfs_check_extent_io_range,
 };
 
 /*
@@ -10575,13 +11024,8 @@
 	.releasepage	= btrfs_releasepage,
 	.set_page_dirty	= btrfs_set_page_dirty,
 	.error_remove_page = generic_error_remove_page,
-};
-
-static const struct address_space_operations btrfs_symlink_aops = {
-	.readpage	= btrfs_readpage,
-	.writepage	= btrfs_writepage,
-	.invalidatepage = btrfs_invalidatepage,
-	.releasepage	= btrfs_releasepage,
+	.swap_activate	= btrfs_swap_activate,
+	.swap_deactivate = btrfs_swap_deactivate,
 };
 
 static const struct inode_operations btrfs_file_inode_operations = {
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index c915215..23272d9 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -43,6 +43,9 @@
 #include "qgroup.h"
 #include "tree-log.h"
 #include "compression.h"
+#include "space-info.h"
+#include "delalloc-space.h"
+#include "block-group.h"
 
 #ifdef CONFIG_64BIT
 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
@@ -189,9 +192,8 @@
 	struct btrfs_trans_handle *trans;
 	unsigned int fsflags, old_fsflags;
 	int ret;
-	u64 old_flags;
-	unsigned int old_i_flags;
-	umode_t mode;
+	const char *comp = NULL;
+	u32 binode_flags = binode->flags;
 
 	if (!inode_owner_or_capable(inode))
 		return -EPERM;
@@ -212,66 +214,59 @@
 
 	inode_lock(inode);
 
-	old_flags = binode->flags;
-	old_i_flags = inode->i_flags;
-	mode = inode->i_mode;
-
 	fsflags = btrfs_mask_fsflags_for_type(inode, fsflags);
 	old_fsflags = btrfs_inode_flags_to_fsflags(binode->flags);
-	if ((fsflags ^ old_fsflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
-		if (!capable(CAP_LINUX_IMMUTABLE)) {
-			ret = -EPERM;
-			goto out_unlock;
-		}
-	}
+	ret = vfs_ioc_setflags_prepare(inode, old_fsflags, fsflags);
+	if (ret)
+		goto out_unlock;
 
 	if (fsflags & FS_SYNC_FL)
-		binode->flags |= BTRFS_INODE_SYNC;
+		binode_flags |= BTRFS_INODE_SYNC;
 	else
-		binode->flags &= ~BTRFS_INODE_SYNC;
+		binode_flags &= ~BTRFS_INODE_SYNC;
 	if (fsflags & FS_IMMUTABLE_FL)
-		binode->flags |= BTRFS_INODE_IMMUTABLE;
+		binode_flags |= BTRFS_INODE_IMMUTABLE;
 	else
-		binode->flags &= ~BTRFS_INODE_IMMUTABLE;
+		binode_flags &= ~BTRFS_INODE_IMMUTABLE;
 	if (fsflags & FS_APPEND_FL)
-		binode->flags |= BTRFS_INODE_APPEND;
+		binode_flags |= BTRFS_INODE_APPEND;
 	else
-		binode->flags &= ~BTRFS_INODE_APPEND;
+		binode_flags &= ~BTRFS_INODE_APPEND;
 	if (fsflags & FS_NODUMP_FL)
-		binode->flags |= BTRFS_INODE_NODUMP;
+		binode_flags |= BTRFS_INODE_NODUMP;
 	else
-		binode->flags &= ~BTRFS_INODE_NODUMP;
+		binode_flags &= ~BTRFS_INODE_NODUMP;
 	if (fsflags & FS_NOATIME_FL)
-		binode->flags |= BTRFS_INODE_NOATIME;
+		binode_flags |= BTRFS_INODE_NOATIME;
 	else
-		binode->flags &= ~BTRFS_INODE_NOATIME;
+		binode_flags &= ~BTRFS_INODE_NOATIME;
 	if (fsflags & FS_DIRSYNC_FL)
-		binode->flags |= BTRFS_INODE_DIRSYNC;
+		binode_flags |= BTRFS_INODE_DIRSYNC;
 	else
-		binode->flags &= ~BTRFS_INODE_DIRSYNC;
+		binode_flags &= ~BTRFS_INODE_DIRSYNC;
 	if (fsflags & FS_NOCOW_FL) {
-		if (S_ISREG(mode)) {
+		if (S_ISREG(inode->i_mode)) {
 			/*
 			 * It's safe to turn csums off here, no extents exist.
 			 * Otherwise we want the flag to reflect the real COW
 			 * status of the file and will not set it.
 			 */
 			if (inode->i_size == 0)
-				binode->flags |= BTRFS_INODE_NODATACOW
-					      | BTRFS_INODE_NODATASUM;
+				binode_flags |= BTRFS_INODE_NODATACOW |
+						BTRFS_INODE_NODATASUM;
 		} else {
-			binode->flags |= BTRFS_INODE_NODATACOW;
+			binode_flags |= BTRFS_INODE_NODATACOW;
 		}
 	} else {
 		/*
 		 * Revert back under same assumptions as above
 		 */
-		if (S_ISREG(mode)) {
+		if (S_ISREG(inode->i_mode)) {
 			if (inode->i_size == 0)
-				binode->flags &= ~(BTRFS_INODE_NODATACOW
-				             | BTRFS_INODE_NODATASUM);
+				binode_flags &= ~(BTRFS_INODE_NODATACOW |
+						  BTRFS_INODE_NODATASUM);
 		} else {
-			binode->flags &= ~BTRFS_INODE_NODATACOW;
+			binode_flags &= ~BTRFS_INODE_NODATACOW;
 		}
 	}
 
@@ -281,52 +276,59 @@
 	 * things smaller.
 	 */
 	if (fsflags & FS_NOCOMP_FL) {
-		binode->flags &= ~BTRFS_INODE_COMPRESS;
-		binode->flags |= BTRFS_INODE_NOCOMPRESS;
-
-		ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
-		if (ret && ret != -ENODATA)
-			goto out_drop;
+		binode_flags &= ~BTRFS_INODE_COMPRESS;
+		binode_flags |= BTRFS_INODE_NOCOMPRESS;
 	} else if (fsflags & FS_COMPR_FL) {
-		const char *comp;
 
-		binode->flags |= BTRFS_INODE_COMPRESS;
-		binode->flags &= ~BTRFS_INODE_NOCOMPRESS;
+		if (IS_SWAPFILE(inode)) {
+			ret = -ETXTBSY;
+			goto out_unlock;
+		}
+
+		binode_flags |= BTRFS_INODE_COMPRESS;
+		binode_flags &= ~BTRFS_INODE_NOCOMPRESS;
 
 		comp = btrfs_compress_type2str(fs_info->compress_type);
 		if (!comp || comp[0] == 0)
 			comp = btrfs_compress_type2str(BTRFS_COMPRESS_ZLIB);
-
-		ret = btrfs_set_prop(inode, "btrfs.compression",
-				     comp, strlen(comp), 0);
-		if (ret)
-			goto out_drop;
-
 	} else {
-		ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
-		if (ret && ret != -ENODATA)
-			goto out_drop;
-		binode->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
+		binode_flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 	}
 
-	trans = btrfs_start_transaction(root, 1);
+	/*
+	 * 1 for inode item
+	 * 2 for properties
+	 */
+	trans = btrfs_start_transaction(root, 3);
 	if (IS_ERR(trans)) {
 		ret = PTR_ERR(trans);
-		goto out_drop;
+		goto out_unlock;
 	}
 
+	if (comp) {
+		ret = btrfs_set_prop(trans, inode, "btrfs.compression", comp,
+				     strlen(comp), 0);
+		if (ret) {
+			btrfs_abort_transaction(trans, ret);
+			goto out_end_trans;
+		}
+	} else {
+		ret = btrfs_set_prop(trans, inode, "btrfs.compression", NULL,
+				     0, 0);
+		if (ret && ret != -ENODATA) {
+			btrfs_abort_transaction(trans, ret);
+			goto out_end_trans;
+		}
+	}
+
+	binode->flags = binode_flags;
 	btrfs_sync_inode_flags_to_i_flags(inode);
 	inode_inc_iversion(inode);
 	inode->i_ctime = current_time(inode);
 	ret = btrfs_update_inode(trans, root, inode);
 
+ out_end_trans:
 	btrfs_end_transaction(trans);
- out_drop:
-	if (ret) {
-		binode->flags = old_flags;
-		inode->i_flags = old_i_flags;
-	}
-
  out_unlock:
 	inode_unlock(inode);
 	mnt_drop_write_file(file);
@@ -374,9 +376,7 @@
 	struct btrfs_inode *binode = BTRFS_I(file_inode(file));
 	struct fsxattr fa;
 
-	memset(&fa, 0, sizeof(fa));
-	fa.fsx_xflags = btrfs_inode_flags_to_xflags(binode->flags);
-
+	simple_fill_fsxattr(&fa, btrfs_inode_flags_to_xflags(binode->flags));
 	if (copy_to_user(arg, &fa, sizeof(fa)))
 		return -EFAULT;
 
@@ -389,7 +389,7 @@
 	struct btrfs_inode *binode = BTRFS_I(inode);
 	struct btrfs_root *root = binode->root;
 	struct btrfs_trans_handle *trans;
-	struct fsxattr fa;
+	struct fsxattr fa, old_fa;
 	unsigned old_flags;
 	unsigned old_i_flags;
 	int ret = 0;
@@ -400,7 +400,6 @@
 	if (btrfs_root_readonly(root))
 		return -EROFS;
 
-	memset(&fa, 0, sizeof(fa));
 	if (copy_from_user(&fa, arg, sizeof(fa)))
 		return -EFAULT;
 
@@ -420,13 +419,11 @@
 	old_flags = binode->flags;
 	old_i_flags = inode->i_flags;
 
-	/* We need the capabilities to change append-only or immutable inode */
-	if (((old_flags & (BTRFS_INODE_APPEND | BTRFS_INODE_IMMUTABLE)) ||
-	     (fa.fsx_xflags & (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE))) &&
-	    !capable(CAP_LINUX_IMMUTABLE)) {
-		ret = -EPERM;
+	simple_fill_fsxattr(&old_fa,
+			    btrfs_inode_flags_to_xflags(binode->flags));
+	ret = vfs_ioc_fssetxattr_check(inode, &old_fa, &fa);
+	if (ret)
 		goto out_unlock;
-	}
 
 	if (fa.fsx_xflags & FS_XFLAG_SYNC)
 		binode->flags |= BTRFS_INODE_SYNC;
@@ -496,6 +493,16 @@
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
+	/*
+	 * If the fs is mounted with nologreplay, which requires it to be
+	 * mounted in RO mode as well, we can not allow discard on free space
+	 * inside block groups, because log trees refer to extents that are not
+	 * pinned in a block group's free space cache (pinning the extents is
+	 * precisely the first phase of replaying a log tree).
+	 */
+	if (btrfs_test_opt(fs_info, NOLOGREPLAY))
+		return -EROFS;
+
 	rcu_read_lock();
 	list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 				dev_list) {
@@ -689,8 +696,7 @@
 		goto fail;
 	}
 
-	ret = btrfs_insert_dir_item(trans, root,
-				    name, namelen, BTRFS_I(dir), &key,
+	ret = btrfs_insert_dir_item(trans, name, namelen, BTRFS_I(dir), &key,
 				    BTRFS_FT_DIR, index);
 	if (ret) {
 		btrfs_abort_transaction(trans, ret);
@@ -755,6 +761,12 @@
 	if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
 		return -EINVAL;
 
+	if (atomic_read(&root->nr_swapfiles)) {
+		btrfs_warn(fs_info,
+			   "cannot snapshot subvolume with active swapfile");
+		return -ETXTBSY;
+	}
+
 	pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
 	if (!pending_snapshot)
 		return -ENOMEM;
@@ -778,7 +790,7 @@
 	wait_event(root->subv_writers->wait,
 		   percpu_counter_sum(&root->subv_writers->counter) == 0);
 
-	ret = btrfs_start_delalloc_inodes(root);
+	ret = btrfs_start_delalloc_snapshot(root);
 	if (ret)
 		goto dec_and_free;
 
@@ -1321,13 +1333,12 @@
 	lock_extent_bits(&BTRFS_I(inode)->io_tree,
 			 page_start, page_end - 1, &cached_state);
 	clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
-			  page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
-			  EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
-			  &cached_state);
+			  page_end - 1, EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
+			  EXTENT_DEFRAG, 0, 0, &cached_state);
 
 	if (i_done != page_cnt) {
 		spin_lock(&BTRFS_I(inode)->lock);
-		BTRFS_I(inode)->outstanding_extents++;
+		btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
 		spin_unlock(&BTRFS_I(inode)->lock);
 		btrfs_delalloc_release_space(inode, data_reserved,
 				start_index << PAGE_SHIFT,
@@ -1349,8 +1360,7 @@
 		unlock_page(pages[i]);
 		put_page(pages[i]);
 	}
-	btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
-				       false);
+	btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT);
 	extent_changeset_free(data_reserved);
 	return i_done;
 out:
@@ -1361,8 +1371,7 @@
 	btrfs_delalloc_release_space(inode, data_reserved,
 			start_index << PAGE_SHIFT,
 			page_cnt << PAGE_SHIFT, true);
-	btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
-				       true);
+	btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT);
 	extent_changeset_free(data_reserved);
 	return ret;
 
@@ -1506,9 +1515,13 @@
 		}
 
 		inode_lock(inode);
-		if (do_compress)
-			BTRFS_I(inode)->defrag_compress = compress_type;
-		ret = cluster_pages_for_defrag(inode, pages, i, cluster);
+		if (IS_SWAPFILE(inode)) {
+			ret = -ETXTBSY;
+		} else {
+			if (do_compress)
+				BTRFS_I(inode)->defrag_compress = compress_type;
+			ret = cluster_pages_for_defrag(inode, pages, i, cluster);
+		}
 		if (ret < 0) {
 			inode_unlock(inode);
 			goto out_ra;
@@ -1628,7 +1641,7 @@
 		btrfs_info(fs_info, "resizing devid %llu", devid);
 	}
 
-	device = btrfs_find_device(fs_info, devid, NULL, NULL);
+	device = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL, true);
 	if (!device) {
 		btrfs_info(fs_info, "resizer unable to find device %llu",
 			   devid);
@@ -1825,8 +1838,15 @@
 		goto free_args;
 	}
 
-	if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
+	if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC) {
+		struct inode *inode = file_inode(file);
+		struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+
+		btrfs_warn(fs_info,
+"SNAP_CREATE_V2 ioctl with CREATE_ASYNC is deprecated and will be removed in kernel 5.7");
+
 		ptr = &transid;
+	}
 	if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
 		readonly = true;
 	if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
@@ -2907,8 +2927,10 @@
 	inode_lock(inode);
 	err = btrfs_delete_subvolume(dir, dentry);
 	inode_unlock(inode);
-	if (!err)
+	if (!err) {
+		fsnotify_rmdir(dir, dentry);
 		d_delete(dentry);
+	}
 
 out_dput:
 	dput(dentry);
@@ -3136,7 +3158,7 @@
 	}
 	rcu_read_unlock();
 
-	memcpy(&fi_args->fsid, fs_info->fsid, sizeof(fi_args->fsid));
+	memcpy(&fi_args->fsid, fs_devices->fsid, sizeof(fi_args->fsid));
 	fi_args->nodesize = fs_info->nodesize;
 	fi_args->sectorsize = fs_info->sectorsize;
 	fi_args->clone_alignment = fs_info->sectorsize;
@@ -3164,7 +3186,8 @@
 		s_uuid = di_args->uuid;
 
 	rcu_read_lock();
-	dev = btrfs_find_device(fs_info, di_args->devid, s_uuid, NULL);
+	dev = btrfs_find_device(fs_info->fs_devices, di_args->devid, s_uuid,
+				NULL, true);
 
 	if (!dev) {
 		ret = -ENODEV;
@@ -3192,362 +3215,38 @@
 	return ret;
 }
 
-static struct page *extent_same_get_page(struct inode *inode, pgoff_t index)
-{
-	struct page *page;
-
-	page = grab_cache_page(inode->i_mapping, index);
-	if (!page)
-		return ERR_PTR(-ENOMEM);
-
-	if (!PageUptodate(page)) {
-		int ret;
-
-		ret = btrfs_readpage(NULL, page);
-		if (ret)
-			return ERR_PTR(ret);
-		lock_page(page);
-		if (!PageUptodate(page)) {
-			unlock_page(page);
-			put_page(page);
-			return ERR_PTR(-EIO);
-		}
-		if (page->mapping != inode->i_mapping) {
-			unlock_page(page);
-			put_page(page);
-			return ERR_PTR(-EAGAIN);
-		}
-	}
-
-	return page;
-}
-
-static int gather_extent_pages(struct inode *inode, struct page **pages,
-			       int num_pages, u64 off)
-{
-	int i;
-	pgoff_t index = off >> PAGE_SHIFT;
-
-	for (i = 0; i < num_pages; i++) {
-again:
-		pages[i] = extent_same_get_page(inode, index + i);
-		if (IS_ERR(pages[i])) {
-			int err = PTR_ERR(pages[i]);
-
-			if (err == -EAGAIN)
-				goto again;
-			pages[i] = NULL;
-			return err;
-		}
-	}
-	return 0;
-}
-
-static int lock_extent_range(struct inode *inode, u64 off, u64 len,
-			     bool retry_range_locking)
-{
-	/*
-	 * Do any pending delalloc/csum calculations on inode, one way or
-	 * another, and lock file content.
-	 * The locking order is:
-	 *
-	 *   1) pages
-	 *   2) range in the inode's io tree
-	 */
-	while (1) {
-		struct btrfs_ordered_extent *ordered;
-		lock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
-		ordered = btrfs_lookup_first_ordered_extent(inode,
-							    off + len - 1);
-		if ((!ordered ||
-		     ordered->file_offset + ordered->len <= off ||
-		     ordered->file_offset >= off + len) &&
-		    !test_range_bit(&BTRFS_I(inode)->io_tree, off,
-				    off + len - 1, EXTENT_DELALLOC, 0, NULL)) {
-			if (ordered)
-				btrfs_put_ordered_extent(ordered);
-			break;
-		}
-		unlock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
-		if (ordered)
-			btrfs_put_ordered_extent(ordered);
-		if (!retry_range_locking)
-			return -EAGAIN;
-		btrfs_wait_ordered_range(inode, off, len);
-	}
-	return 0;
-}
-
-static void btrfs_double_inode_unlock(struct inode *inode1, struct inode *inode2)
-{
-	inode_unlock(inode1);
-	inode_unlock(inode2);
-}
-
-static void btrfs_double_inode_lock(struct inode *inode1, struct inode *inode2)
-{
-	if (inode1 < inode2)
-		swap(inode1, inode2);
-
-	inode_lock_nested(inode1, I_MUTEX_PARENT);
-	inode_lock_nested(inode2, I_MUTEX_CHILD);
-}
-
 static void btrfs_double_extent_unlock(struct inode *inode1, u64 loff1,
-				      struct inode *inode2, u64 loff2, u64 len)
+				       struct inode *inode2, u64 loff2, u64 len)
 {
 	unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
 	unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
 }
 
-static int btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
-				    struct inode *inode2, u64 loff2, u64 len,
-				    bool retry_range_locking)
+static void btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
+				     struct inode *inode2, u64 loff2, u64 len)
 {
-	int ret;
-
 	if (inode1 < inode2) {
 		swap(inode1, inode2);
 		swap(loff1, loff2);
+	} else if (inode1 == inode2 && loff2 < loff1) {
+		swap(loff1, loff2);
 	}
-	ret = lock_extent_range(inode1, loff1, len, retry_range_locking);
-	if (ret)
-		return ret;
-	ret = lock_extent_range(inode2, loff2, len, retry_range_locking);
-	if (ret)
-		unlock_extent(&BTRFS_I(inode1)->io_tree, loff1,
-			      loff1 + len - 1);
-	return ret;
+	lock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
+	lock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
 }
 
-struct cmp_pages {
-	int		num_pages;
-	struct page	**src_pages;
-	struct page	**dst_pages;
-};
-
-static void btrfs_cmp_data_free(struct cmp_pages *cmp)
-{
-	int i;
-	struct page *pg;
-
-	for (i = 0; i < cmp->num_pages; i++) {
-		pg = cmp->src_pages[i];
-		if (pg) {
-			unlock_page(pg);
-			put_page(pg);
-			cmp->src_pages[i] = NULL;
-		}
-		pg = cmp->dst_pages[i];
-		if (pg) {
-			unlock_page(pg);
-			put_page(pg);
-			cmp->dst_pages[i] = NULL;
-		}
-	}
-}
-
-static int btrfs_cmp_data_prepare(struct inode *src, u64 loff,
-				  struct inode *dst, u64 dst_loff,
-				  u64 len, struct cmp_pages *cmp)
+static int btrfs_extent_same_range(struct inode *src, u64 loff, u64 len,
+				   struct inode *dst, u64 dst_loff)
 {
 	int ret;
-	int num_pages = PAGE_ALIGN(len) >> PAGE_SHIFT;
 
-	cmp->num_pages = num_pages;
-
-	ret = gather_extent_pages(src, cmp->src_pages, num_pages, loff);
-	if (ret)
-		goto out;
-
-	ret = gather_extent_pages(dst, cmp->dst_pages, num_pages, dst_loff);
-
-out:
-	if (ret)
-		btrfs_cmp_data_free(cmp);
-	return ret;
-}
-
-static int btrfs_cmp_data(u64 len, struct cmp_pages *cmp)
-{
-	int ret = 0;
-	int i;
-	struct page *src_page, *dst_page;
-	unsigned int cmp_len = PAGE_SIZE;
-	void *addr, *dst_addr;
-
-	i = 0;
-	while (len) {
-		if (len < PAGE_SIZE)
-			cmp_len = len;
-
-		BUG_ON(i >= cmp->num_pages);
-
-		src_page = cmp->src_pages[i];
-		dst_page = cmp->dst_pages[i];
-		ASSERT(PageLocked(src_page));
-		ASSERT(PageLocked(dst_page));
-
-		addr = kmap_atomic(src_page);
-		dst_addr = kmap_atomic(dst_page);
-
-		flush_dcache_page(src_page);
-		flush_dcache_page(dst_page);
-
-		if (memcmp(addr, dst_addr, cmp_len))
-			ret = -EBADE;
-
-		kunmap_atomic(addr);
-		kunmap_atomic(dst_addr);
-
-		if (ret)
-			break;
-
-		len -= cmp_len;
-		i++;
-	}
-
-	return ret;
-}
-
-static int extent_same_check_offsets(struct inode *inode, u64 off, u64 *plen,
-				     u64 olen)
-{
-	u64 len = *plen;
-	u64 bs = BTRFS_I(inode)->root->fs_info->sb->s_blocksize;
-
-	if (off + olen > inode->i_size || off + olen < off)
-		return -EINVAL;
-
-	/* if we extend to eof, continue to block boundary */
-	if (off + len == inode->i_size)
-		*plen = len = ALIGN(inode->i_size, bs) - off;
-
-	/* Check that we are block aligned - btrfs_clone() requires this */
-	if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs))
-		return -EINVAL;
-
-	return 0;
-}
-
-static int btrfs_extent_same_range(struct inode *src, u64 loff, u64 olen,
-				   struct inode *dst, u64 dst_loff,
-				   struct cmp_pages *cmp)
-{
-	int ret;
-	u64 len = olen;
-	bool same_inode = (src == dst);
-	u64 same_lock_start = 0;
-	u64 same_lock_len = 0;
-
-	ret = extent_same_check_offsets(src, loff, &len, olen);
-	if (ret)
-		return ret;
-
-	ret = extent_same_check_offsets(dst, dst_loff, &len, olen);
-	if (ret)
-		return ret;
-
-	if (same_inode) {
-		/*
-		 * Single inode case wants the same checks, except we
-		 * don't want our length pushed out past i_size as
-		 * comparing that data range makes no sense.
-		 *
-		 * extent_same_check_offsets() will do this for an
-		 * unaligned length at i_size, so catch it here and
-		 * reject the request.
-		 *
-		 * This effectively means we require aligned extents
-		 * for the single-inode case, whereas the other cases
-		 * allow an unaligned length so long as it ends at
-		 * i_size.
-		 */
-		if (len != olen)
-			return -EINVAL;
-
-		/* Check for overlapping ranges */
-		if (dst_loff + len > loff && dst_loff < loff + len)
-			return -EINVAL;
-
-		same_lock_start = min_t(u64, loff, dst_loff);
-		same_lock_len = max_t(u64, loff, dst_loff) + len - same_lock_start;
-	} else {
-		/*
-		 * If the source and destination inodes are different, the
-		 * source's range end offset matches the source's i_size, that
-		 * i_size is not a multiple of the sector size, and the
-		 * destination range does not go past the destination's i_size,
-		 * we must round down the length to the nearest sector size
-		 * multiple. If we don't do this adjustment we end replacing
-		 * with zeroes the bytes in the range that starts at the
-		 * deduplication range's end offset and ends at the next sector
-		 * size multiple.
-		 */
-		if (loff + olen == i_size_read(src) &&
-		    dst_loff + len < i_size_read(dst)) {
-			const u64 sz = BTRFS_I(src)->root->fs_info->sectorsize;
-
-			len = round_down(i_size_read(src), sz) - loff;
-			if (len == 0)
-				return 0;
-			olen = len;
-		}
-	}
-
-again:
-	ret = btrfs_cmp_data_prepare(src, loff, dst, dst_loff, olen, cmp);
-	if (ret)
-		return ret;
-
-	if (same_inode)
-		ret = lock_extent_range(src, same_lock_start, same_lock_len,
-					false);
-	else
-		ret = btrfs_double_extent_lock(src, loff, dst, dst_loff, len,
-					       false);
 	/*
-	 * If one of the inodes has dirty pages in the respective range or
-	 * ordered extents, we need to flush dellaloc and wait for all ordered
-	 * extents in the range. We must unlock the pages and the ranges in the
-	 * io trees to avoid deadlocks when flushing delalloc (requires locking
-	 * pages) and when waiting for ordered extents to complete (they require
-	 * range locking).
+	 * Lock destination range to serialize with concurrent readpages() and
+	 * source range to serialize with relocation.
 	 */
-	if (ret == -EAGAIN) {
-		/*
-		 * Ranges in the io trees already unlocked. Now unlock all
-		 * pages before waiting for all IO to complete.
-		 */
-		btrfs_cmp_data_free(cmp);
-		if (same_inode) {
-			btrfs_wait_ordered_range(src, same_lock_start,
-						 same_lock_len);
-		} else {
-			btrfs_wait_ordered_range(src, loff, len);
-			btrfs_wait_ordered_range(dst, dst_loff, len);
-		}
-		goto again;
-	}
-	ASSERT(ret == 0);
-	if (WARN_ON(ret)) {
-		/* ranges in the io trees already unlocked */
-		btrfs_cmp_data_free(cmp);
-		return ret;
-	}
-
-	/* pass original length for comparison so we stay within i_size */
-	ret = btrfs_cmp_data(olen, cmp);
-	if (ret == 0)
-		ret = btrfs_clone(src, dst, loff, olen, len, dst_loff, 1);
-
-	if (same_inode)
-		unlock_extent(&BTRFS_I(src)->io_tree, same_lock_start,
-			      same_lock_start + same_lock_len - 1);
-	else
-		btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
-
-	btrfs_cmp_data_free(cmp);
+	btrfs_double_extent_lock(src, loff, dst, dst_loff, len);
+	ret = btrfs_clone(src, dst, loff, len, len, dst_loff, 1);
+	btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
 
 	return ret;
 }
@@ -3558,58 +3257,29 @@
 			     struct inode *dst, u64 dst_loff)
 {
 	int ret;
-	struct cmp_pages cmp;
-	int num_pages = PAGE_ALIGN(BTRFS_MAX_DEDUPE_LEN) >> PAGE_SHIFT;
-	bool same_inode = (src == dst);
 	u64 i, tail_len, chunk_count;
+	struct btrfs_root *root_dst = BTRFS_I(dst)->root;
 
-	if (olen == 0)
-		return 0;
-
-	if (same_inode)
-		inode_lock(src);
-	else
-		btrfs_double_inode_lock(src, dst);
-
-	/* don't make the dst file partly checksummed */
-	if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
-	    (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
-		ret = -EINVAL;
-		goto out_unlock;
+	spin_lock(&root_dst->root_item_lock);
+	if (root_dst->send_in_progress) {
+		btrfs_warn_rl(root_dst->fs_info,
+"cannot deduplicate to root %llu while send operations are using it (%d in progress)",
+			      root_dst->root_key.objectid,
+			      root_dst->send_in_progress);
+		spin_unlock(&root_dst->root_item_lock);
+		return -EAGAIN;
 	}
+	root_dst->dedupe_in_progress++;
+	spin_unlock(&root_dst->root_item_lock);
 
 	tail_len = olen % BTRFS_MAX_DEDUPE_LEN;
 	chunk_count = div_u64(olen, BTRFS_MAX_DEDUPE_LEN);
-	if (chunk_count == 0)
-		num_pages = PAGE_ALIGN(tail_len) >> PAGE_SHIFT;
-
-	/*
-	 * If deduping ranges in the same inode, locking rules make it
-	 * mandatory to always lock pages in ascending order to avoid deadlocks
-	 * with concurrent tasks (such as starting writeback/delalloc).
-	 */
-	if (same_inode && dst_loff < loff)
-		swap(loff, dst_loff);
-
-	/*
-	 * We must gather up all the pages before we initiate our extent
-	 * locking. We use an array for the page pointers. Size of the array is
-	 * bounded by len, which is in turn bounded by BTRFS_MAX_DEDUPE_LEN.
-	 */
-	cmp.src_pages = kvmalloc_array(num_pages, sizeof(struct page *),
-				       GFP_KERNEL | __GFP_ZERO);
-	cmp.dst_pages = kvmalloc_array(num_pages, sizeof(struct page *),
-				       GFP_KERNEL | __GFP_ZERO);
-	if (!cmp.src_pages || !cmp.dst_pages) {
-		ret = -ENOMEM;
-		goto out_free;
-	}
 
 	for (i = 0; i < chunk_count; i++) {
 		ret = btrfs_extent_same_range(src, loff, BTRFS_MAX_DEDUPE_LEN,
-					      dst, dst_loff, &cmp);
+					      dst, dst_loff);
 		if (ret)
-			goto out_free;
+			goto out;
 
 		loff += BTRFS_MAX_DEDUPE_LEN;
 		dst_loff += BTRFS_MAX_DEDUPE_LEN;
@@ -3617,41 +3287,15 @@
 
 	if (tail_len > 0)
 		ret = btrfs_extent_same_range(src, loff, tail_len, dst,
-					      dst_loff, &cmp);
-
-out_free:
-	kvfree(cmp.src_pages);
-	kvfree(cmp.dst_pages);
-
-out_unlock:
-	if (same_inode)
-		inode_unlock(src);
-	else
-		btrfs_double_inode_unlock(src, dst);
+					      dst_loff);
+out:
+	spin_lock(&root_dst->root_item_lock);
+	root_dst->dedupe_in_progress--;
+	spin_unlock(&root_dst->root_item_lock);
 
 	return ret;
 }
 
-int btrfs_dedupe_file_range(struct file *src_file, loff_t src_loff,
-			    struct file *dst_file, loff_t dst_loff,
-			    u64 olen)
-{
-	struct inode *src = file_inode(src_file);
-	struct inode *dst = file_inode(dst_file);
-	u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
-
-	if (WARN_ON_ONCE(bs < PAGE_SIZE)) {
-		/*
-		 * Btrfs does not support blocksize < page_size. As a
-		 * result, btrfs_cmp_data() won't correctly handle
-		 * this situation without an update.
-		 */
-		return -EINVAL;
-	}
-
-	return btrfs_extent_same(src, src_loff, olen, dst, dst_loff);
-}
-
 static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
 				     struct inode *inode,
 				     u64 endoff,
@@ -3685,61 +3329,6 @@
 	return ret;
 }
 
-static void clone_update_extent_map(struct btrfs_inode *inode,
-				    const struct btrfs_trans_handle *trans,
-				    const struct btrfs_path *path,
-				    const u64 hole_offset,
-				    const u64 hole_len)
-{
-	struct extent_map_tree *em_tree = &inode->extent_tree;
-	struct extent_map *em;
-	int ret;
-
-	em = alloc_extent_map();
-	if (!em) {
-		set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
-		return;
-	}
-
-	if (path) {
-		struct btrfs_file_extent_item *fi;
-
-		fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
-				    struct btrfs_file_extent_item);
-		btrfs_extent_item_to_extent_map(inode, path, fi, false, em);
-		em->generation = -1;
-		if (btrfs_file_extent_type(path->nodes[0], fi) ==
-		    BTRFS_FILE_EXTENT_INLINE)
-			set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
-					&inode->runtime_flags);
-	} else {
-		em->start = hole_offset;
-		em->len = hole_len;
-		em->ram_bytes = em->len;
-		em->orig_start = hole_offset;
-		em->block_start = EXTENT_MAP_HOLE;
-		em->block_len = 0;
-		em->orig_block_len = 0;
-		em->compress_type = BTRFS_COMPRESS_NONE;
-		em->generation = trans->transid;
-	}
-
-	while (1) {
-		write_lock(&em_tree->lock);
-		ret = add_extent_mapping(em_tree, em, 1);
-		write_unlock(&em_tree->lock);
-		if (ret != -EEXIST) {
-			free_extent_map(em);
-			break;
-		}
-		btrfs_drop_extent_cache(inode, em->start,
-					em->start + em->len - 1, 0);
-	}
-
-	if (ret)
-		set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
-}
-
 /*
  * Make sure we do not end up inserting an inline extent into a file that has
  * already other (non-inline) extents. If a file has an inline extent it can
@@ -3880,6 +3469,7 @@
 						  path->slots[0]),
 			    size);
 	inode_add_bytes(dst, datal);
+	set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(dst)->runtime_flags);
 
 	return 0;
 }
@@ -3931,6 +3521,14 @@
 
 	while (1) {
 		u64 next_key_min_offset = key.offset + 1;
+		struct btrfs_file_extent_item *extent;
+		int type;
+		u32 size;
+		struct btrfs_key new_key;
+		u64 disko = 0, diskl = 0;
+		u64 datao = 0, datal = 0;
+		u8 comp;
+		u64 drop_start;
 
 		/*
 		 * note the key will change type as we walk through the
@@ -3971,75 +3569,115 @@
 		    key.objectid != btrfs_ino(BTRFS_I(src)))
 			break;
 
-		if (key.type == BTRFS_EXTENT_DATA_KEY) {
-			struct btrfs_file_extent_item *extent;
-			int type;
-			u32 size;
-			struct btrfs_key new_key;
-			u64 disko = 0, diskl = 0;
-			u64 datao = 0, datal = 0;
-			u8 comp;
-			u64 drop_start;
+		ASSERT(key.type == BTRFS_EXTENT_DATA_KEY);
 
-			extent = btrfs_item_ptr(leaf, slot,
-						struct btrfs_file_extent_item);
-			comp = btrfs_file_extent_compression(leaf, extent);
-			type = btrfs_file_extent_type(leaf, extent);
-			if (type == BTRFS_FILE_EXTENT_REG ||
-			    type == BTRFS_FILE_EXTENT_PREALLOC) {
-				disko = btrfs_file_extent_disk_bytenr(leaf,
-								      extent);
-				diskl = btrfs_file_extent_disk_num_bytes(leaf,
-								 extent);
-				datao = btrfs_file_extent_offset(leaf, extent);
-				datal = btrfs_file_extent_num_bytes(leaf,
-								    extent);
-			} else if (type == BTRFS_FILE_EXTENT_INLINE) {
-				/* take upper bound, may be compressed */
-				datal = btrfs_file_extent_ram_bytes(leaf,
-								    extent);
+		extent = btrfs_item_ptr(leaf, slot,
+					struct btrfs_file_extent_item);
+		comp = btrfs_file_extent_compression(leaf, extent);
+		type = btrfs_file_extent_type(leaf, extent);
+		if (type == BTRFS_FILE_EXTENT_REG ||
+		    type == BTRFS_FILE_EXTENT_PREALLOC) {
+			disko = btrfs_file_extent_disk_bytenr(leaf, extent);
+			diskl = btrfs_file_extent_disk_num_bytes(leaf, extent);
+			datao = btrfs_file_extent_offset(leaf, extent);
+			datal = btrfs_file_extent_num_bytes(leaf, extent);
+		} else if (type == BTRFS_FILE_EXTENT_INLINE) {
+			/* Take upper bound, may be compressed */
+			datal = btrfs_file_extent_ram_bytes(leaf, extent);
+		}
+
+		/*
+		 * The first search might have left us at an extent item that
+		 * ends before our target range's start, can happen if we have
+		 * holes and NO_HOLES feature enabled.
+		 */
+		if (key.offset + datal <= off) {
+			path->slots[0]++;
+			goto process_slot;
+		} else if (key.offset >= off + len) {
+			break;
+		}
+		next_key_min_offset = key.offset + datal;
+		size = btrfs_item_size_nr(leaf, slot);
+		read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, slot),
+				   size);
+
+		btrfs_release_path(path);
+		path->leave_spinning = 0;
+
+		memcpy(&new_key, &key, sizeof(new_key));
+		new_key.objectid = btrfs_ino(BTRFS_I(inode));
+		if (off <= key.offset)
+			new_key.offset = key.offset + destoff - off;
+		else
+			new_key.offset = destoff;
+
+		/*
+		 * Deal with a hole that doesn't have an extent item that
+		 * represents it (NO_HOLES feature enabled).
+		 * This hole is either in the middle of the cloning range or at
+		 * the beginning (fully overlaps it or partially overlaps it).
+		 */
+		if (new_key.offset != last_dest_end)
+			drop_start = last_dest_end;
+		else
+			drop_start = new_key.offset;
+
+		if (type == BTRFS_FILE_EXTENT_REG ||
+		    type == BTRFS_FILE_EXTENT_PREALLOC) {
+			struct btrfs_clone_extent_info clone_info;
+
+			/*
+			 *    a  | --- range to clone ---|  b
+			 * | ------------- extent ------------- |
+			 */
+
+			/* Subtract range b */
+			if (key.offset + datal > off + len)
+				datal = off + len - key.offset;
+
+			/* Subtract range a */
+			if (off > key.offset) {
+				datao += off - key.offset;
+				datal -= off - key.offset;
 			}
 
-			/*
-			 * The first search might have left us at an extent
-			 * item that ends before our target range's start, can
-			 * happen if we have holes and NO_HOLES feature enabled.
-			 */
-			if (key.offset + datal <= off) {
-				path->slots[0]++;
-				goto process_slot;
-			} else if (key.offset >= off + len) {
-				break;
+			clone_info.disk_offset = disko;
+			clone_info.disk_len = diskl;
+			clone_info.data_offset = datao;
+			clone_info.data_len = datal;
+			clone_info.file_offset = new_key.offset;
+			clone_info.extent_buf = buf;
+			clone_info.item_size = size;
+			ret = btrfs_punch_hole_range(inode, path,
+						     drop_start,
+						     new_key.offset + datal - 1,
+						     &clone_info, &trans);
+			if (ret)
+				goto out;
+		} else if (type == BTRFS_FILE_EXTENT_INLINE) {
+			u64 skip = 0;
+			u64 trim = 0;
+
+			if (off > key.offset) {
+				skip = off - key.offset;
+				new_key.offset += skip;
 			}
-			next_key_min_offset = key.offset + datal;
-			size = btrfs_item_size_nr(leaf, slot);
-			read_extent_buffer(leaf, buf,
-					   btrfs_item_ptr_offset(leaf, slot),
-					   size);
 
-			btrfs_release_path(path);
-			path->leave_spinning = 0;
+			if (key.offset + datal > off + len)
+				trim = key.offset + datal - (off + len);
 
-			memcpy(&new_key, &key, sizeof(new_key));
-			new_key.objectid = btrfs_ino(BTRFS_I(inode));
-			if (off <= key.offset)
-				new_key.offset = key.offset + destoff - off;
-			else
-				new_key.offset = destoff;
+			if (comp && (skip || trim)) {
+				ret = -EINVAL;
+				goto out;
+			}
+			size -= skip + trim;
+			datal -= skip + trim;
 
 			/*
-			 * Deal with a hole that doesn't have an extent item
-			 * that represents it (NO_HOLES feature enabled).
-			 * This hole is either in the middle of the cloning
-			 * range or at the beginning (fully overlaps it or
-			 * partially overlaps it).
-			 */
-			if (new_key.offset != last_dest_end)
-				drop_start = last_dest_end;
-			else
-				drop_start = new_key.offset;
-
-			/*
+			 * If our extent is inline, we know we will drop or
+			 * adjust at most 1 extent item in the destination root.
+			 *
 			 * 1 - adjusting old extent (we may have to split it)
 			 * 1 - add new extent
 			 * 1 - inode update
@@ -4050,137 +3688,28 @@
 				goto out;
 			}
 
-			if (type == BTRFS_FILE_EXTENT_REG ||
-			    type == BTRFS_FILE_EXTENT_PREALLOC) {
-				/*
-				 *    a  | --- range to clone ---|  b
-				 * | ------------- extent ------------- |
-				 */
-
-				/* subtract range b */
-				if (key.offset + datal > off + len)
-					datal = off + len - key.offset;
-
-				/* subtract range a */
-				if (off > key.offset) {
-					datao += off - key.offset;
-					datal -= off - key.offset;
-				}
-
-				ret = btrfs_drop_extents(trans, root, inode,
-							 drop_start,
-							 new_key.offset + datal,
-							 1);
-				if (ret) {
-					if (ret != -EOPNOTSUPP)
-						btrfs_abort_transaction(trans,
-									ret);
-					btrfs_end_transaction(trans);
-					goto out;
-				}
-
-				ret = btrfs_insert_empty_item(trans, root, path,
-							      &new_key, size);
-				if (ret) {
+			ret = clone_copy_inline_extent(inode, trans, path,
+						       &new_key, drop_start,
+						       datal, skip, size, buf);
+			if (ret) {
+				if (ret != -EOPNOTSUPP)
 					btrfs_abort_transaction(trans, ret);
-					btrfs_end_transaction(trans);
-					goto out;
-				}
-
-				leaf = path->nodes[0];
-				slot = path->slots[0];
-				write_extent_buffer(leaf, buf,
-					    btrfs_item_ptr_offset(leaf, slot),
-					    size);
-
-				extent = btrfs_item_ptr(leaf, slot,
-						struct btrfs_file_extent_item);
-
-				/* disko == 0 means it's a hole */
-				if (!disko)
-					datao = 0;
-
-				btrfs_set_file_extent_offset(leaf, extent,
-							     datao);
-				btrfs_set_file_extent_num_bytes(leaf, extent,
-								datal);
-
-				if (disko) {
-					inode_add_bytes(inode, datal);
-					ret = btrfs_inc_extent_ref(trans,
-							root,
-							disko, diskl, 0,
-							root->root_key.objectid,
-							btrfs_ino(BTRFS_I(inode)),
-							new_key.offset - datao);
-					if (ret) {
-						btrfs_abort_transaction(trans,
-									ret);
-						btrfs_end_transaction(trans);
-						goto out;
-
-					}
-				}
-			} else if (type == BTRFS_FILE_EXTENT_INLINE) {
-				u64 skip = 0;
-				u64 trim = 0;
-
-				if (off > key.offset) {
-					skip = off - key.offset;
-					new_key.offset += skip;
-				}
-
-				if (key.offset + datal > off + len)
-					trim = key.offset + datal - (off + len);
-
-				if (comp && (skip || trim)) {
-					ret = -EINVAL;
-					btrfs_end_transaction(trans);
-					goto out;
-				}
-				size -= skip + trim;
-				datal -= skip + trim;
-
-				ret = clone_copy_inline_extent(inode,
-							       trans, path,
-							       &new_key,
-							       drop_start,
-							       datal,
-							       skip, size, buf);
-				if (ret) {
-					if (ret != -EOPNOTSUPP)
-						btrfs_abort_transaction(trans,
-									ret);
-					btrfs_end_transaction(trans);
-					goto out;
-				}
-				leaf = path->nodes[0];
-				slot = path->slots[0];
-			}
-
-			/* If we have an implicit hole (NO_HOLES feature). */
-			if (drop_start < new_key.offset)
-				clone_update_extent_map(BTRFS_I(inode), trans,
-						NULL, drop_start,
-						new_key.offset - drop_start);
-
-			clone_update_extent_map(BTRFS_I(inode), trans,
-					path, 0, 0);
-
-			btrfs_mark_buffer_dirty(leaf);
-			btrfs_release_path(path);
-
-			last_dest_end = ALIGN(new_key.offset + datal,
-					      fs_info->sectorsize);
-			ret = clone_finish_inode_update(trans, inode,
-							last_dest_end,
-							destoff, olen,
-							no_time_update);
-			if (ret)
+				btrfs_end_transaction(trans);
 				goto out;
-			if (new_key.offset + datal >= destoff + len)
-				break;
+			}
 		}
+
+		btrfs_release_path(path);
+
+		last_dest_end = ALIGN(new_key.offset + datal,
+				      fs_info->sectorsize);
+		ret = clone_finish_inode_update(trans, inode, last_dest_end,
+						destoff, olen, no_time_update);
+		if (ret)
+			goto out;
+		if (new_key.offset + datal >= destoff + len)
+			break;
+
 		btrfs_release_path(path);
 		key.offset = next_key_min_offset;
 
@@ -4192,32 +3721,27 @@
 	ret = 0;
 
 	if (last_dest_end < destoff + len) {
+		struct btrfs_clone_extent_info clone_info = { 0 };
 		/*
 		 * We have an implicit hole (NO_HOLES feature is enabled) that
 		 * fully or partially overlaps our cloning range at its end.
 		 */
 		btrfs_release_path(path);
+		path->leave_spinning = 0;
 
 		/*
-		 * 1 - remove extent(s)
-		 * 1 - inode update
+		 * We are dealing with a hole and our clone_info already has a
+		 * disk_offset of 0, we only need to fill the data length and
+		 * file offset.
 		 */
-		trans = btrfs_start_transaction(root, 2);
-		if (IS_ERR(trans)) {
-			ret = PTR_ERR(trans);
+		clone_info.data_len = destoff + len - last_dest_end;
+		clone_info.file_offset = last_dest_end;
+		ret = btrfs_punch_hole_range(inode, path,
+					     last_dest_end, destoff + len - 1,
+					     &clone_info, &trans);
+		if (ret)
 			goto out;
-		}
-		ret = btrfs_drop_extents(trans, root, inode,
-					 last_dest_end, destoff + len, 1);
-		if (ret) {
-			if (ret != -EOPNOTSUPP)
-				btrfs_abort_transaction(trans, ret);
-			btrfs_end_transaction(trans);
-			goto out;
-		}
-		clone_update_extent_map(BTRFS_I(inode), trans, NULL,
-				last_dest_end,
-				destoff + len - last_dest_end);
+
 		ret = clone_finish_inode_update(trans, inode, destoff + len,
 						destoff, olen, no_time_update);
 	}
@@ -4234,11 +3758,9 @@
 	struct inode *inode = file_inode(file);
 	struct inode *src = file_inode(file_src);
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
-	struct btrfs_root *root = BTRFS_I(inode)->root;
 	int ret;
 	u64 len = olen;
 	u64 bs = fs_info->sb->s_blocksize;
-	int same_inode = src == inode;
 
 	/*
 	 * TODO:
@@ -4251,101 +3773,43 @@
 	 *   be either compressed or non-compressed.
 	 */
 
-	if (btrfs_root_readonly(root))
-		return -EROFS;
-
-	if (file_src->f_path.mnt != file->f_path.mnt ||
-	    src->i_sb != inode->i_sb)
-		return -EXDEV;
-
-	if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
-		return -EISDIR;
-
-	if (!same_inode) {
-		btrfs_double_inode_lock(src, inode);
-	} else {
-		inode_lock(src);
-	}
-
-	/* don't make the dst file partly checksummed */
-	if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
-	    (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
-		ret = -EINVAL;
-		goto out_unlock;
-	}
-
-	/* determine range to clone */
-	ret = -EINVAL;
-	if (off + len > src->i_size || off + len < off)
-		goto out_unlock;
-	if (len == 0)
-		olen = len = src->i_size - off;
 	/*
-	 * If we extend to eof, continue to block boundary if and only if the
-	 * destination end offset matches the destination file's size, otherwise
-	 * we would be corrupting data by placing the eof block into the middle
-	 * of a file.
+	 * VFS's generic_remap_file_range_prep() protects us from cloning the
+	 * eof block into the middle of a file, which would result in corruption
+	 * if the file size is not blocksize aligned. So we don't need to check
+	 * for that case here.
 	 */
-	if (off + len == src->i_size) {
-		if (!IS_ALIGNED(len, bs) && destoff + len < inode->i_size)
-			goto out_unlock;
+	if (off + len == src->i_size)
 		len = ALIGN(src->i_size, bs) - off;
-	}
-
-	if (len == 0) {
-		ret = 0;
-		goto out_unlock;
-	}
-
-	/* verify the end result is block aligned */
-	if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
-	    !IS_ALIGNED(destoff, bs))
-		goto out_unlock;
-
-	/* verify if ranges are overlapped within the same file */
-	if (same_inode) {
-		if (destoff + len > off && destoff < off + len)
-			goto out_unlock;
-	}
 
 	if (destoff > inode->i_size) {
+		const u64 wb_start = ALIGN_DOWN(inode->i_size, bs);
+
 		ret = btrfs_cont_expand(inode, inode->i_size, destoff);
 		if (ret)
-			goto out_unlock;
+			return ret;
+		/*
+		 * We may have truncated the last block if the inode's size is
+		 * not sector size aligned, so we need to wait for writeback to
+		 * complete before proceeding further, otherwise we can race
+		 * with cloning and attempt to increment a reference to an
+		 * extent that no longer exists (writeback completed right after
+		 * we found the previous extent covering eof and before we
+		 * attempted to increment its reference count).
+		 */
+		ret = btrfs_wait_ordered_range(inode, wb_start,
+					       destoff - wb_start);
+		if (ret)
+			return ret;
 	}
 
 	/*
-	 * Lock the target range too. Right after we replace the file extent
-	 * items in the fs tree (which now point to the cloned data), we might
-	 * have a worker replace them with extent items relative to a write
-	 * operation that was issued before this clone operation (i.e. confront
-	 * with inode.c:btrfs_finish_ordered_io).
+	 * Lock destination range to serialize with concurrent readpages() and
+	 * source range to serialize with relocation.
 	 */
-	if (same_inode) {
-		u64 lock_start = min_t(u64, off, destoff);
-		u64 lock_len = max_t(u64, off, destoff) + len - lock_start;
-
-		ret = lock_extent_range(src, lock_start, lock_len, true);
-	} else {
-		ret = btrfs_double_extent_lock(src, off, inode, destoff, len,
-					       true);
-	}
-	ASSERT(ret == 0);
-	if (WARN_ON(ret)) {
-		/* ranges in the io trees already unlocked */
-		goto out_unlock;
-	}
-
+	btrfs_double_extent_lock(src, off, inode, destoff, len);
 	ret = btrfs_clone(src, inode, off, olen, len, destoff, 0);
-
-	if (same_inode) {
-		u64 lock_start = min_t(u64, off, destoff);
-		u64 lock_end = max_t(u64, off, destoff) + len - 1;
-
-		unlock_extent(&BTRFS_I(src)->io_tree, lock_start, lock_end);
-	} else {
-		btrfs_double_extent_unlock(src, off, inode, destoff, len);
-	}
+	btrfs_double_extent_unlock(src, off, inode, destoff, len);
 	/*
 	 * Truncate page cache pages so that future reads will see the cloned
 	 * data immediately and not the previous data.
@@ -4353,18 +3817,134 @@
 	truncate_inode_pages_range(&inode->i_data,
 				round_down(destoff, PAGE_SIZE),
 				round_up(destoff + len, PAGE_SIZE) - 1);
-out_unlock:
-	if (!same_inode)
-		btrfs_double_inode_unlock(src, inode);
-	else
-		inode_unlock(src);
+
 	return ret;
 }
 
-int btrfs_clone_file_range(struct file *src_file, loff_t off,
-		struct file *dst_file, loff_t destoff, u64 len)
+static int btrfs_remap_file_range_prep(struct file *file_in, loff_t pos_in,
+				       struct file *file_out, loff_t pos_out,
+				       loff_t *len, unsigned int remap_flags)
 {
-	return btrfs_clone_files(dst_file, src_file, off, len, destoff);
+	struct inode *inode_in = file_inode(file_in);
+	struct inode *inode_out = file_inode(file_out);
+	u64 bs = BTRFS_I(inode_out)->root->fs_info->sb->s_blocksize;
+	bool same_inode = inode_out == inode_in;
+	u64 wb_len;
+	int ret;
+
+	if (!(remap_flags & REMAP_FILE_DEDUP)) {
+		struct btrfs_root *root_out = BTRFS_I(inode_out)->root;
+
+		if (btrfs_root_readonly(root_out))
+			return -EROFS;
+
+		if (file_in->f_path.mnt != file_out->f_path.mnt ||
+		    inode_in->i_sb != inode_out->i_sb)
+			return -EXDEV;
+	}
+
+	/* don't make the dst file partly checksummed */
+	if ((BTRFS_I(inode_in)->flags & BTRFS_INODE_NODATASUM) !=
+	    (BTRFS_I(inode_out)->flags & BTRFS_INODE_NODATASUM)) {
+		return -EINVAL;
+	}
+
+	/*
+	 * Now that the inodes are locked, we need to start writeback ourselves
+	 * and can not rely on the writeback from the VFS's generic helper
+	 * generic_remap_file_range_prep() because:
+	 *
+	 * 1) For compression we must call filemap_fdatawrite_range() range
+	 *    twice (btrfs_fdatawrite_range() does it for us), and the generic
+	 *    helper only calls it once;
+	 *
+	 * 2) filemap_fdatawrite_range(), called by the generic helper only
+	 *    waits for the writeback to complete, i.e. for IO to be done, and
+	 *    not for the ordered extents to complete. We need to wait for them
+	 *    to complete so that new file extent items are in the fs tree.
+	 */
+	if (*len == 0 && !(remap_flags & REMAP_FILE_DEDUP))
+		wb_len = ALIGN(inode_in->i_size, bs) - ALIGN_DOWN(pos_in, bs);
+	else
+		wb_len = ALIGN(*len, bs);
+
+	/*
+	 * Since we don't lock ranges, wait for ongoing lockless dio writes (as
+	 * any in progress could create its ordered extents after we wait for
+	 * existing ordered extents below).
+	 */
+	inode_dio_wait(inode_in);
+	if (!same_inode)
+		inode_dio_wait(inode_out);
+
+	/*
+	 * Workaround to make sure NOCOW buffered write reach disk as NOCOW.
+	 *
+	 * Btrfs' back references do not have a block level granularity, they
+	 * work at the whole extent level.
+	 * NOCOW buffered write without data space reserved may not be able
+	 * to fall back to CoW due to lack of data space, thus could cause
+	 * data loss.
+	 *
+	 * Here we take a shortcut by flushing the whole inode, so that all
+	 * nocow write should reach disk as nocow before we increase the
+	 * reference of the extent. We could do better by only flushing NOCOW
+	 * data, but that needs extra accounting.
+	 *
+	 * Also we don't need to check ASYNC_EXTENT, as async extent will be
+	 * CoWed anyway, not affecting nocow part.
+	 */
+	ret = filemap_flush(inode_in->i_mapping);
+	if (ret < 0)
+		return ret;
+
+	ret = btrfs_wait_ordered_range(inode_in, ALIGN_DOWN(pos_in, bs),
+				       wb_len);
+	if (ret < 0)
+		return ret;
+	ret = btrfs_wait_ordered_range(inode_out, ALIGN_DOWN(pos_out, bs),
+				       wb_len);
+	if (ret < 0)
+		return ret;
+
+	return generic_remap_file_range_prep(file_in, pos_in, file_out, pos_out,
+					    len, remap_flags);
+}
+
+loff_t btrfs_remap_file_range(struct file *src_file, loff_t off,
+		struct file *dst_file, loff_t destoff, loff_t len,
+		unsigned int remap_flags)
+{
+	struct inode *src_inode = file_inode(src_file);
+	struct inode *dst_inode = file_inode(dst_file);
+	bool same_inode = dst_inode == src_inode;
+	int ret;
+
+	if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY))
+		return -EINVAL;
+
+	if (same_inode)
+		inode_lock(src_inode);
+	else
+		lock_two_nondirectories(src_inode, dst_inode);
+
+	ret = btrfs_remap_file_range_prep(src_file, off, dst_file, destoff,
+					  &len, remap_flags);
+	if (ret < 0 || len == 0)
+		goto out_unlock;
+
+	if (remap_flags & REMAP_FILE_DEDUP)
+		ret = btrfs_extent_same(src_inode, off, len, dst_inode, destoff);
+	else
+		ret = btrfs_clone_files(dst_file, src_file, off, len, destoff);
+
+out_unlock:
+	if (same_inode)
+		inode_unlock(src_inode);
+	else
+		unlock_two_nondirectories(src_inode, dst_inode);
+
+	return ret < 0 ? ret : len;
 }
 
 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
@@ -4406,7 +3986,7 @@
 		ret = PTR_ERR(new_root);
 		goto out;
 	}
-	if (!is_fstree(new_root->objectid)) {
+	if (!is_fstree(new_root->root_key.objectid)) {
 		ret = -ENOENT;
 		goto out;
 	}
@@ -4674,7 +4254,7 @@
 			      &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
 			      0);
 
-	if (copy_to_user(arg, sa, sizeof(*sa)))
+	if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
 		ret = -EFAULT;
 
 	if (!(sa->flags & BTRFS_SCRUB_READONLY))
@@ -4707,7 +4287,7 @@
 
 	ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
 
-	if (copy_to_user(arg, sa, sizeof(*sa)))
+	if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
 		ret = -EFAULT;
 
 	kfree(sa);
@@ -4731,7 +4311,7 @@
 
 	ret = btrfs_get_dev_stats(fs_info, sa);
 
-	if (copy_to_user(arg, sa, sizeof(*sa)))
+	if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
 		ret = -EFAULT;
 
 	kfree(sa);
@@ -4777,7 +4357,7 @@
 		break;
 	}
 
-	if (copy_to_user(arg, p, sizeof(*p)))
+	if ((ret == 0 || ret == -ECANCELED) && copy_to_user(arg, p, sizeof(*p)))
 		ret = -EFAULT;
 out:
 	kfree(p);
@@ -5083,7 +4663,7 @@
 	ret = btrfs_balance(fs_info, bctl, bargs);
 	bctl = NULL;
 
-	if (arg) {
+	if ((ret == 0 || ret == -ECANCELED) && arg) {
 		if (copy_to_user(arg, bargs, sizeof(*bargs)))
 			ret = -EFAULT;
 	}
@@ -5683,7 +5263,7 @@
 			      u64 change_mask, u64 flags, u64 supported_flags,
 			      u64 safe_set, u64 safe_clear)
 {
-	const char *type = btrfs_feature_set_names[set];
+	const char *type = btrfs_feature_set_name(set);
 	char *names;
 	u64 disallowed, unsupported;
 	u64 set_mask = flags & change_mask;
@@ -5864,6 +5444,10 @@
 		return btrfs_ioctl_setflags(file, argp);
 	case FS_IOC_GETVERSION:
 		return btrfs_ioctl_getversion(file, argp);
+	case FS_IOC_GETFSLABEL:
+		return btrfs_ioctl_get_fslabel(file, argp);
+	case FS_IOC_SETFSLABEL:
+		return btrfs_ioctl_set_fslabel(file, argp);
 	case FITRIM:
 		return btrfs_ioctl_fitrim(file, argp);
 	case BTRFS_IOC_SNAP_CREATE:
@@ -5975,10 +5559,6 @@
 		return btrfs_ioctl_quota_rescan_wait(file, argp);
 	case BTRFS_IOC_DEV_REPLACE:
 		return btrfs_ioctl_dev_replace(fs_info, argp);
-	case BTRFS_IOC_GET_FSLABEL:
-		return btrfs_ioctl_get_fslabel(file, argp);
-	case BTRFS_IOC_SET_FSLABEL:
-		return btrfs_ioctl_set_fslabel(file, argp);
 	case BTRFS_IOC_GET_SUPPORTED_FEATURES:
 		return btrfs_ioctl_get_supported_features(argp);
 	case BTRFS_IOC_GET_FEATURES:
diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c
index 1da768e..7f9a578 100644
--- a/fs/btrfs/locking.c
+++ b/fs/btrfs/locking.c
@@ -8,74 +8,115 @@
 #include <linux/spinlock.h>
 #include <linux/page-flags.h>
 #include <asm/bug.h>
+#include "misc.h"
 #include "ctree.h"
 #include "extent_io.h"
 #include "locking.h"
 
-static void btrfs_assert_tree_read_locked(struct extent_buffer *eb);
-
-/*
- * if we currently have a spinning reader or writer lock
- * (indicated by the rw flag) this will bump the count
- * of blocking holders and drop the spinlock.
- */
-void btrfs_set_lock_blocking_rw(struct extent_buffer *eb, int rw)
+#ifdef CONFIG_BTRFS_DEBUG
+static void btrfs_assert_spinning_writers_get(struct extent_buffer *eb)
 {
-	/*
-	 * no lock is required.  The lock owner may change if
-	 * we have a read lock, but it won't change to or away
-	 * from us.  If we have the write lock, we are the owner
-	 * and it'll never change.
-	 */
-	if (eb->lock_nested && current->pid == eb->lock_owner)
-		return;
-	if (rw == BTRFS_WRITE_LOCK) {
-		if (atomic_read(&eb->blocking_writers) == 0) {
-			WARN_ON(atomic_read(&eb->spinning_writers) != 1);
-			atomic_dec(&eb->spinning_writers);
-			btrfs_assert_tree_locked(eb);
-			atomic_inc(&eb->blocking_writers);
-			write_unlock(&eb->lock);
-		}
-	} else if (rw == BTRFS_READ_LOCK) {
-		btrfs_assert_tree_read_locked(eb);
-		atomic_inc(&eb->blocking_readers);
-		WARN_ON(atomic_read(&eb->spinning_readers) == 0);
-		atomic_dec(&eb->spinning_readers);
-		read_unlock(&eb->lock);
-	}
+	WARN_ON(eb->spinning_writers);
+	eb->spinning_writers++;
 }
 
-/*
- * if we currently have a blocking lock, take the spinlock
- * and drop our blocking count
- */
-void btrfs_clear_lock_blocking_rw(struct extent_buffer *eb, int rw)
+static void btrfs_assert_spinning_writers_put(struct extent_buffer *eb)
 {
+	WARN_ON(eb->spinning_writers != 1);
+	eb->spinning_writers--;
+}
+
+static void btrfs_assert_no_spinning_writers(struct extent_buffer *eb)
+{
+	WARN_ON(eb->spinning_writers);
+}
+
+static void btrfs_assert_spinning_readers_get(struct extent_buffer *eb)
+{
+	atomic_inc(&eb->spinning_readers);
+}
+
+static void btrfs_assert_spinning_readers_put(struct extent_buffer *eb)
+{
+	WARN_ON(atomic_read(&eb->spinning_readers) == 0);
+	atomic_dec(&eb->spinning_readers);
+}
+
+static void btrfs_assert_tree_read_locks_get(struct extent_buffer *eb)
+{
+	atomic_inc(&eb->read_locks);
+}
+
+static void btrfs_assert_tree_read_locks_put(struct extent_buffer *eb)
+{
+	atomic_dec(&eb->read_locks);
+}
+
+static void btrfs_assert_tree_read_locked(struct extent_buffer *eb)
+{
+	BUG_ON(!atomic_read(&eb->read_locks));
+}
+
+static void btrfs_assert_tree_write_locks_get(struct extent_buffer *eb)
+{
+	eb->write_locks++;
+}
+
+static void btrfs_assert_tree_write_locks_put(struct extent_buffer *eb)
+{
+	eb->write_locks--;
+}
+
+void btrfs_assert_tree_locked(struct extent_buffer *eb)
+{
+	BUG_ON(!eb->write_locks);
+}
+
+#else
+static void btrfs_assert_spinning_writers_get(struct extent_buffer *eb) { }
+static void btrfs_assert_spinning_writers_put(struct extent_buffer *eb) { }
+static void btrfs_assert_no_spinning_writers(struct extent_buffer *eb) { }
+static void btrfs_assert_spinning_readers_put(struct extent_buffer *eb) { }
+static void btrfs_assert_spinning_readers_get(struct extent_buffer *eb) { }
+static void btrfs_assert_tree_read_locked(struct extent_buffer *eb) { }
+static void btrfs_assert_tree_read_locks_get(struct extent_buffer *eb) { }
+static void btrfs_assert_tree_read_locks_put(struct extent_buffer *eb) { }
+void btrfs_assert_tree_locked(struct extent_buffer *eb) { }
+static void btrfs_assert_tree_write_locks_get(struct extent_buffer *eb) { }
+static void btrfs_assert_tree_write_locks_put(struct extent_buffer *eb) { }
+#endif
+
+void btrfs_set_lock_blocking_read(struct extent_buffer *eb)
+{
+	trace_btrfs_set_lock_blocking_read(eb);
 	/*
-	 * no lock is required.  The lock owner may change if
-	 * we have a read lock, but it won't change to or away
-	 * from us.  If we have the write lock, we are the owner
-	 * and it'll never change.
+	 * No lock is required.  The lock owner may change if we have a read
+	 * lock, but it won't change to or away from us.  If we have the write
+	 * lock, we are the owner and it'll never change.
 	 */
 	if (eb->lock_nested && current->pid == eb->lock_owner)
 		return;
+	btrfs_assert_tree_read_locked(eb);
+	atomic_inc(&eb->blocking_readers);
+	btrfs_assert_spinning_readers_put(eb);
+	read_unlock(&eb->lock);
+}
 
-	if (rw == BTRFS_WRITE_LOCK_BLOCKING) {
-		BUG_ON(atomic_read(&eb->blocking_writers) != 1);
-		write_lock(&eb->lock);
-		WARN_ON(atomic_read(&eb->spinning_writers));
-		atomic_inc(&eb->spinning_writers);
-		/* atomic_dec_and_test implies a barrier */
-		if (atomic_dec_and_test(&eb->blocking_writers))
-			cond_wake_up_nomb(&eb->write_lock_wq);
-	} else if (rw == BTRFS_READ_LOCK_BLOCKING) {
-		BUG_ON(atomic_read(&eb->blocking_readers) == 0);
-		read_lock(&eb->lock);
-		atomic_inc(&eb->spinning_readers);
-		/* atomic_dec_and_test implies a barrier */
-		if (atomic_dec_and_test(&eb->blocking_readers))
-			cond_wake_up_nomb(&eb->read_lock_wq);
+void btrfs_set_lock_blocking_write(struct extent_buffer *eb)
+{
+	trace_btrfs_set_lock_blocking_write(eb);
+	/*
+	 * No lock is required.  The lock owner may change if we have a read
+	 * lock, but it won't change to or away from us.  If we have the write
+	 * lock, we are the owner and it'll never change.
+	 */
+	if (eb->lock_nested && current->pid == eb->lock_owner)
+		return;
+	if (eb->blocking_writers == 0) {
+		btrfs_assert_spinning_writers_put(eb);
+		btrfs_assert_tree_locked(eb);
+		eb->blocking_writers++;
+		write_unlock(&eb->lock);
 	}
 }
 
@@ -85,13 +126,15 @@
  */
 void btrfs_tree_read_lock(struct extent_buffer *eb)
 {
-again:
-	BUG_ON(!atomic_read(&eb->blocking_writers) &&
-	       current->pid == eb->lock_owner);
+	u64 start_ns = 0;
 
+	if (trace_btrfs_tree_read_lock_enabled())
+		start_ns = ktime_get_ns();
+again:
 	read_lock(&eb->lock);
-	if (atomic_read(&eb->blocking_writers) &&
-	    current->pid == eb->lock_owner) {
+	BUG_ON(eb->blocking_writers == 0 &&
+	       current->pid == eb->lock_owner);
+	if (eb->blocking_writers && current->pid == eb->lock_owner) {
 		/*
 		 * This extent is already write-locked by our thread. We allow
 		 * an additional read lock to be added because it's for the same
@@ -99,18 +142,20 @@
 		 * called on a partly (write-)locked tree.
 		 */
 		BUG_ON(eb->lock_nested);
-		eb->lock_nested = 1;
+		eb->lock_nested = true;
 		read_unlock(&eb->lock);
+		trace_btrfs_tree_read_lock(eb, start_ns);
 		return;
 	}
-	if (atomic_read(&eb->blocking_writers)) {
+	if (eb->blocking_writers) {
 		read_unlock(&eb->lock);
 		wait_event(eb->write_lock_wq,
-			   atomic_read(&eb->blocking_writers) == 0);
+			   eb->blocking_writers == 0);
 		goto again;
 	}
-	atomic_inc(&eb->read_locks);
-	atomic_inc(&eb->spinning_readers);
+	btrfs_assert_tree_read_locks_get(eb);
+	btrfs_assert_spinning_readers_get(eb);
+	trace_btrfs_tree_read_lock(eb, start_ns);
 }
 
 /*
@@ -120,16 +165,17 @@
  */
 int btrfs_tree_read_lock_atomic(struct extent_buffer *eb)
 {
-	if (atomic_read(&eb->blocking_writers))
+	if (eb->blocking_writers)
 		return 0;
 
 	read_lock(&eb->lock);
-	if (atomic_read(&eb->blocking_writers)) {
+	if (eb->blocking_writers) {
 		read_unlock(&eb->lock);
 		return 0;
 	}
-	atomic_inc(&eb->read_locks);
-	atomic_inc(&eb->spinning_readers);
+	btrfs_assert_tree_read_locks_get(eb);
+	btrfs_assert_spinning_readers_get(eb);
+	trace_btrfs_tree_read_lock_atomic(eb);
 	return 1;
 }
 
@@ -139,18 +185,19 @@
  */
 int btrfs_try_tree_read_lock(struct extent_buffer *eb)
 {
-	if (atomic_read(&eb->blocking_writers))
+	if (eb->blocking_writers)
 		return 0;
 
 	if (!read_trylock(&eb->lock))
 		return 0;
 
-	if (atomic_read(&eb->blocking_writers)) {
+	if (eb->blocking_writers) {
 		read_unlock(&eb->lock);
 		return 0;
 	}
-	atomic_inc(&eb->read_locks);
-	atomic_inc(&eb->spinning_readers);
+	btrfs_assert_tree_read_locks_get(eb);
+	btrfs_assert_spinning_readers_get(eb);
+	trace_btrfs_try_tree_read_lock(eb);
 	return 1;
 }
 
@@ -160,19 +207,18 @@
  */
 int btrfs_try_tree_write_lock(struct extent_buffer *eb)
 {
-	if (atomic_read(&eb->blocking_writers) ||
-	    atomic_read(&eb->blocking_readers))
+	if (eb->blocking_writers || atomic_read(&eb->blocking_readers))
 		return 0;
 
 	write_lock(&eb->lock);
-	if (atomic_read(&eb->blocking_writers) ||
-	    atomic_read(&eb->blocking_readers)) {
+	if (eb->blocking_writers || atomic_read(&eb->blocking_readers)) {
 		write_unlock(&eb->lock);
 		return 0;
 	}
-	atomic_inc(&eb->write_locks);
-	atomic_inc(&eb->spinning_writers);
+	btrfs_assert_tree_write_locks_get(eb);
+	btrfs_assert_spinning_writers_get(eb);
 	eb->lock_owner = current->pid;
+	trace_btrfs_try_tree_write_lock(eb);
 	return 1;
 }
 
@@ -181,6 +227,7 @@
  */
 void btrfs_tree_read_unlock(struct extent_buffer *eb)
 {
+	trace_btrfs_tree_read_unlock(eb);
 	/*
 	 * if we're nested, we have the write lock.  No new locking
 	 * is needed as long as we are the lock owner.
@@ -188,13 +235,12 @@
 	 * field only matters to the lock owner.
 	 */
 	if (eb->lock_nested && current->pid == eb->lock_owner) {
-		eb->lock_nested = 0;
+		eb->lock_nested = false;
 		return;
 	}
 	btrfs_assert_tree_read_locked(eb);
-	WARN_ON(atomic_read(&eb->spinning_readers) == 0);
-	atomic_dec(&eb->spinning_readers);
-	atomic_dec(&eb->read_locks);
+	btrfs_assert_spinning_readers_put(eb);
+	btrfs_assert_tree_read_locks_put(eb);
 	read_unlock(&eb->lock);
 }
 
@@ -203,6 +249,7 @@
  */
 void btrfs_tree_read_unlock_blocking(struct extent_buffer *eb)
 {
+	trace_btrfs_tree_read_unlock_blocking(eb);
 	/*
 	 * if we're nested, we have the write lock.  No new locking
 	 * is needed as long as we are the lock owner.
@@ -210,7 +257,7 @@
 	 * field only matters to the lock owner.
 	 */
 	if (eb->lock_nested && current->pid == eb->lock_owner) {
-		eb->lock_nested = 0;
+		eb->lock_nested = false;
 		return;
 	}
 	btrfs_assert_tree_read_locked(eb);
@@ -218,7 +265,7 @@
 	/* atomic_dec_and_test implies a barrier */
 	if (atomic_dec_and_test(&eb->blocking_readers))
 		cond_wake_up_nomb(&eb->read_lock_wq);
-	atomic_dec(&eb->read_locks);
+	btrfs_assert_tree_read_locks_put(eb);
 }
 
 /*
@@ -227,27 +274,24 @@
  */
 void btrfs_tree_lock(struct extent_buffer *eb)
 {
+	u64 start_ns = 0;
+
+	if (trace_btrfs_tree_lock_enabled())
+		start_ns = ktime_get_ns();
+
 	WARN_ON(eb->lock_owner == current->pid);
 again:
 	wait_event(eb->read_lock_wq, atomic_read(&eb->blocking_readers) == 0);
-	wait_event(eb->write_lock_wq, atomic_read(&eb->blocking_writers) == 0);
+	wait_event(eb->write_lock_wq, eb->blocking_writers == 0);
 	write_lock(&eb->lock);
-	if (atomic_read(&eb->blocking_readers)) {
+	if (atomic_read(&eb->blocking_readers) || eb->blocking_writers) {
 		write_unlock(&eb->lock);
-		wait_event(eb->read_lock_wq,
-			   atomic_read(&eb->blocking_readers) == 0);
 		goto again;
 	}
-	if (atomic_read(&eb->blocking_writers)) {
-		write_unlock(&eb->lock);
-		wait_event(eb->write_lock_wq,
-			   atomic_read(&eb->blocking_writers) == 0);
-		goto again;
-	}
-	WARN_ON(atomic_read(&eb->spinning_writers));
-	atomic_inc(&eb->spinning_writers);
-	atomic_inc(&eb->write_locks);
+	btrfs_assert_spinning_writers_get(eb);
+	btrfs_assert_tree_write_locks_get(eb);
 	eb->lock_owner = current->pid;
+	trace_btrfs_tree_lock(eb, start_ns);
 }
 
 /*
@@ -255,33 +299,26 @@
  */
 void btrfs_tree_unlock(struct extent_buffer *eb)
 {
-	int blockers = atomic_read(&eb->blocking_writers);
+	int blockers = eb->blocking_writers;
 
 	BUG_ON(blockers > 1);
 
 	btrfs_assert_tree_locked(eb);
+	trace_btrfs_tree_unlock(eb);
 	eb->lock_owner = 0;
-	atomic_dec(&eb->write_locks);
+	btrfs_assert_tree_write_locks_put(eb);
 
 	if (blockers) {
-		WARN_ON(atomic_read(&eb->spinning_writers));
-		atomic_dec(&eb->blocking_writers);
-		/* Use the lighter barrier after atomic */
-		smp_mb__after_atomic();
-		cond_wake_up_nomb(&eb->write_lock_wq);
+		btrfs_assert_no_spinning_writers(eb);
+		eb->blocking_writers--;
+		/*
+		 * We need to order modifying blocking_writers above with
+		 * actually waking up the sleepers to ensure they see the
+		 * updated value of blocking_writers
+		 */
+		cond_wake_up(&eb->write_lock_wq);
 	} else {
-		WARN_ON(atomic_read(&eb->spinning_writers) != 1);
-		atomic_dec(&eb->spinning_writers);
+		btrfs_assert_spinning_writers_put(eb);
 		write_unlock(&eb->lock);
 	}
 }
-
-void btrfs_assert_tree_locked(struct extent_buffer *eb)
-{
-	BUG_ON(!atomic_read(&eb->write_locks));
-}
-
-static void btrfs_assert_tree_read_locked(struct extent_buffer *eb)
-{
-	BUG_ON(!atomic_read(&eb->read_locks));
-}
diff --git a/fs/btrfs/locking.h b/fs/btrfs/locking.h
index 29135de..b775a42 100644
--- a/fs/btrfs/locking.h
+++ b/fs/btrfs/locking.h
@@ -17,8 +17,8 @@
 void btrfs_tree_read_lock(struct extent_buffer *eb);
 void btrfs_tree_read_unlock(struct extent_buffer *eb);
 void btrfs_tree_read_unlock_blocking(struct extent_buffer *eb);
-void btrfs_set_lock_blocking_rw(struct extent_buffer *eb, int rw);
-void btrfs_clear_lock_blocking_rw(struct extent_buffer *eb, int rw);
+void btrfs_set_lock_blocking_read(struct extent_buffer *eb);
+void btrfs_set_lock_blocking_write(struct extent_buffer *eb);
 void btrfs_assert_tree_locked(struct extent_buffer *eb);
 int btrfs_try_tree_read_lock(struct extent_buffer *eb);
 int btrfs_try_tree_write_lock(struct extent_buffer *eb);
@@ -37,13 +37,4 @@
 		BUG();
 }
 
-static inline void btrfs_set_lock_blocking(struct extent_buffer *eb)
-{
-	btrfs_set_lock_blocking_rw(eb, BTRFS_WRITE_LOCK);
-}
-
-static inline void btrfs_clear_lock_blocking(struct extent_buffer *eb)
-{
-	btrfs_clear_lock_blocking_rw(eb, BTRFS_WRITE_LOCK_BLOCKING);
-}
 #endif
diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c
index b6a4cc1..acad417 100644
--- a/fs/btrfs/lzo.c
+++ b/fs/btrfs/lzo.c
@@ -27,7 +27,7 @@
  *     Records the total size (including the header) of compressed data.
  *
  * 2.  Segment(s)
- *     Variable size. Each segment includes one segment header, followd by data
+ *     Variable size. Each segment includes one segment header, followed by data
  *     payload.
  *     One regular LZO compressed extent can have one or more segments.
  *     For inlined LZO compressed extent, only one segment is allowed.
@@ -61,6 +61,28 @@
 	struct list_head list;
 };
 
+static struct workspace_manager wsm;
+
+static void lzo_init_workspace_manager(void)
+{
+	btrfs_init_workspace_manager(&wsm, &btrfs_lzo_compress);
+}
+
+static void lzo_cleanup_workspace_manager(void)
+{
+	btrfs_cleanup_workspace_manager(&wsm);
+}
+
+static struct list_head *lzo_get_workspace(unsigned int level)
+{
+	return btrfs_get_workspace(&wsm, level);
+}
+
+static void lzo_put_workspace(struct list_head *ws)
+{
+	btrfs_put_workspace(&wsm, ws);
+}
+
 static void lzo_free_workspace(struct list_head *ws)
 {
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
@@ -71,7 +93,7 @@
 	kfree(workspace);
 }
 
-static struct list_head *lzo_alloc_workspace(void)
+static struct list_head *lzo_alloc_workspace(unsigned int level)
 {
 	struct workspace *workspace;
 
@@ -485,15 +507,16 @@
 	return ret;
 }
 
-static void lzo_set_level(struct list_head *ws, unsigned int type)
-{
-}
-
 const struct btrfs_compress_op btrfs_lzo_compress = {
+	.init_workspace_manager	= lzo_init_workspace_manager,
+	.cleanup_workspace_manager = lzo_cleanup_workspace_manager,
+	.get_workspace		= lzo_get_workspace,
+	.put_workspace		= lzo_put_workspace,
 	.alloc_workspace	= lzo_alloc_workspace,
 	.free_workspace		= lzo_free_workspace,
 	.compress_pages		= lzo_compress_pages,
 	.decompress_bio		= lzo_decompress_bio,
 	.decompress		= lzo_decompress,
-	.set_level		= lzo_set_level,
+	.max_level		= 1,
+	.default_level		= 1,
 };
diff --git a/fs/btrfs/math.h b/fs/btrfs/math.h
deleted file mode 100644
index 75246f2..0000000
--- a/fs/btrfs/math.h
+++ /dev/null
@@ -1,28 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * Copyright (C) 2012 Fujitsu.  All rights reserved.
- * Written by Miao Xie <miaox@cn.fujitsu.com>
- */
-
-#ifndef BTRFS_MATH_H
-#define BTRFS_MATH_H
-
-#include <asm/div64.h>
-
-static inline u64 div_factor(u64 num, int factor)
-{
-	if (factor == 10)
-		return num;
-	num *= factor;
-	return div_u64(num, 10);
-}
-
-static inline u64 div_factor_fine(u64 num, int factor)
-{
-	if (factor == 100)
-		return num;
-	num *= factor;
-	return div_u64(num, 100);
-}
-
-#endif
diff --git a/fs/btrfs/misc.h b/fs/btrfs/misc.h
new file mode 100644
index 0000000..7d56492
--- /dev/null
+++ b/fs/btrfs/misc.h
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef BTRFS_MISC_H
+#define BTRFS_MISC_H
+
+#include <linux/sched.h>
+#include <linux/wait.h>
+#include <asm/div64.h>
+
+#define in_range(b, first, len) ((b) >= (first) && (b) < (first) + (len))
+
+static inline void cond_wake_up(struct wait_queue_head *wq)
+{
+	/*
+	 * This implies a full smp_mb barrier, see comments for
+	 * waitqueue_active why.
+	 */
+	if (wq_has_sleeper(wq))
+		wake_up(wq);
+}
+
+static inline void cond_wake_up_nomb(struct wait_queue_head *wq)
+{
+	/*
+	 * Special case for conditional wakeup where the barrier required for
+	 * waitqueue_active is implied by some of the preceding code. Eg. one
+	 * of such atomic operations (atomic_dec_and_return, ...), or a
+	 * unlock/lock sequence, etc.
+	 */
+	if (waitqueue_active(wq))
+		wake_up(wq);
+}
+
+static inline u64 div_factor(u64 num, int factor)
+{
+	if (factor == 10)
+		return num;
+	num *= factor;
+	return div_u64(num, 10);
+}
+
+static inline u64 div_factor_fine(u64 num, int factor)
+{
+	if (factor == 100)
+		return num;
+	num *= factor;
+	return div_u64(num, 100);
+}
+
+#endif
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index 0c4ef20..24b6c72 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -6,12 +6,15 @@
 #include <linux/slab.h>
 #include <linux/blkdev.h>
 #include <linux/writeback.h>
+#include <linux/sched/mm.h>
+#include "misc.h"
 #include "ctree.h"
 #include "transaction.h"
 #include "btrfs_inode.h"
 #include "extent_io.h"
 #include "disk-io.h"
 #include "compression.h"
+#include "delalloc-space.h"
 
 static struct kmem_cache *btrfs_ordered_extent_cache;
 
@@ -194,8 +197,11 @@
 	if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE)
 		set_bit(type, &entry->flags);
 
-	if (dio)
+	if (dio) {
+		percpu_counter_add_batch(&fs_info->dio_bytes, len,
+					 fs_info->delalloc_batch);
 		set_bit(BTRFS_ORDERED_DIRECT, &entry->flags);
+	}
 
 	/* one ref for the tree */
 	refcount_set(&entry->refs, 1);
@@ -270,13 +276,12 @@
  * when an ordered extent is finished.  If the list covers more than one
  * ordered extent, it is split across multiples.
  */
-void btrfs_add_ordered_sum(struct inode *inode,
-			   struct btrfs_ordered_extent *entry,
+void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
 			   struct btrfs_ordered_sum *sum)
 {
 	struct btrfs_ordered_inode_tree *tree;
 
-	tree = &BTRFS_I(inode)->ordered_tree;
+	tree = &BTRFS_I(entry->inode)->ordered_tree;
 	spin_lock_irq(&tree->lock);
 	list_add_tail(&sum->list, &entry->list);
 	spin_unlock_irq(&tree->lock);
@@ -442,7 +447,7 @@
 			cur = entry->list.next;
 			sum = list_entry(cur, struct btrfs_ordered_sum, list);
 			list_del(&sum->list);
-			kfree(sum);
+			kvfree(sum);
 		}
 		kmem_cache_free(btrfs_ordered_extent_cache, entry);
 	}
@@ -460,7 +465,6 @@
 	struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
 	struct btrfs_root *root = btrfs_inode->root;
 	struct rb_node *node;
-	bool dec_pending_ordered = false;
 
 	/* This is paired with btrfs_add_ordered_extent. */
 	spin_lock(&btrfs_inode->lock);
@@ -469,6 +473,10 @@
 	if (root != fs_info->tree_root)
 		btrfs_delalloc_release_metadata(btrfs_inode, entry->len, false);
 
+	if (test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
+		percpu_counter_add_batch(&fs_info->dio_bytes, -entry->len,
+					 fs_info->delalloc_batch);
+
 	tree = &btrfs_inode->ordered_tree;
 	spin_lock_irq(&tree->lock);
 	node = &entry->rb_node;
@@ -477,37 +485,8 @@
 	if (tree->last == node)
 		tree->last = NULL;
 	set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
-	if (test_and_clear_bit(BTRFS_ORDERED_PENDING, &entry->flags))
-		dec_pending_ordered = true;
 	spin_unlock_irq(&tree->lock);
 
-	/*
-	 * The current running transaction is waiting on us, we need to let it
-	 * know that we're complete and wake it up.
-	 */
-	if (dec_pending_ordered) {
-		struct btrfs_transaction *trans;
-
-		/*
-		 * The checks for trans are just a formality, it should be set,
-		 * but if it isn't we don't want to deref/assert under the spin
-		 * lock, so be nice and check if trans is set, but ASSERT() so
-		 * if it isn't set a developer will notice.
-		 */
-		spin_lock(&fs_info->trans_lock);
-		trans = fs_info->running_transaction;
-		if (trans)
-			refcount_inc(&trans->use_count);
-		spin_unlock(&fs_info->trans_lock);
-
-		ASSERT(trans);
-		if (trans) {
-			if (atomic_dec_and_test(&trans->pending_ordered))
-				wake_up(&trans->pending_wait);
-			btrfs_put_transaction(trans);
-		}
-	}
-
 	spin_lock(&root->ordered_extent_lock);
 	list_del_init(&entry->root_extent_list);
 	root->nr_ordered_extents--;
@@ -947,14 +926,16 @@
  * be reclaimed before their checksum is actually put into the btree
  */
 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
-			   u32 *sum, int len)
+			   u8 *sum, int len)
 {
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_ordered_sum *ordered_sum;
 	struct btrfs_ordered_extent *ordered;
 	struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
 	unsigned long num_sectors;
 	unsigned long i;
 	u32 sectorsize = btrfs_inode_sectorsize(inode);
+	const u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
 	int index = 0;
 
 	ordered = btrfs_lookup_ordered_extent(inode, offset);
@@ -970,10 +951,10 @@
 			num_sectors = ordered_sum->len >>
 				      inode->i_sb->s_blocksize_bits;
 			num_sectors = min_t(int, len - index, num_sectors - i);
-			memcpy(sum + index, ordered_sum->sums + i,
-			       num_sectors);
+			memcpy(sum + index, ordered_sum->sums + i * csum_size,
+			       num_sectors * csum_size);
 
-			index += (int)num_sectors;
+			index += (int)num_sectors * csum_size;
 			if (index == len)
 				goto out;
 			disk_bytenr += num_sectors * sectorsize;
@@ -985,6 +966,52 @@
 	return index;
 }
 
+/*
+ * btrfs_flush_ordered_range - Lock the passed range and ensures all pending
+ * ordered extents in it are run to completion.
+ *
+ * @tree:         IO tree used for locking out other users of the range
+ * @inode:        Inode whose ordered tree is to be searched
+ * @start:        Beginning of range to flush
+ * @end:          Last byte of range to lock
+ * @cached_state: If passed, will return the extent state responsible for the
+ * locked range. It's the caller's responsibility to free the cached state.
+ *
+ * This function always returns with the given range locked, ensuring after it's
+ * called no order extent can be pending.
+ */
+void btrfs_lock_and_flush_ordered_range(struct extent_io_tree *tree,
+					struct btrfs_inode *inode, u64 start,
+					u64 end,
+					struct extent_state **cached_state)
+{
+	struct btrfs_ordered_extent *ordered;
+	struct extent_state *cache = NULL;
+	struct extent_state **cachedp = &cache;
+
+	if (cached_state)
+		cachedp = cached_state;
+
+	while (1) {
+		lock_extent_bits(tree, start, end, cachedp);
+		ordered = btrfs_lookup_ordered_range(inode, start,
+						     end - start + 1);
+		if (!ordered) {
+			/*
+			 * If no external cached_state has been passed then
+			 * decrement the extra ref taken for cachedp since we
+			 * aren't exposing it outside of this function
+			 */
+			if (!cached_state)
+				refcount_dec(&cache->refs);
+			break;
+		}
+		unlock_extent_cached(tree, start, end, cachedp);
+		btrfs_start_ordered_extent(&inode->vfs_inode, ordered, 1);
+		btrfs_put_ordered_extent(ordered);
+	}
+}
+
 int __init ordered_data_init(void)
 {
 	btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h
index 02d813a..5204171 100644
--- a/fs/btrfs/ordered-data.h
+++ b/fs/btrfs/ordered-data.h
@@ -23,7 +23,7 @@
 	int len;
 	struct list_head list;
 	/* last field is a variable length array of csums */
-	u32 sums[];
+	u8 sums[];
 };
 
 /*
@@ -37,28 +37,31 @@
  * rbtree, just before waking any waiters.  It is used to indicate the
  * IO is done and any metadata is inserted into the tree.
  */
-#define BTRFS_ORDERED_IO_DONE 0 /* set when all the pages are written */
-
-#define BTRFS_ORDERED_COMPLETE 1 /* set when removed from the tree */
-
-#define BTRFS_ORDERED_NOCOW 2 /* set when we want to write in place */
-
-#define BTRFS_ORDERED_COMPRESSED 3 /* writing a zlib compressed extent */
-
-#define BTRFS_ORDERED_PREALLOC 4 /* set when writing to preallocated extent */
-
-#define BTRFS_ORDERED_DIRECT 5 /* set when we're doing DIO with this extent */
-
-#define BTRFS_ORDERED_IOERR 6 /* We had an io error when writing this out */
-
-#define BTRFS_ORDERED_UPDATED_ISIZE 7 /* indicates whether this ordered extent
-				       * has done its due diligence in updating
-				       * the isize. */
-#define BTRFS_ORDERED_TRUNCATED 8 /* Set when we have to truncate an extent */
-
-#define BTRFS_ORDERED_PENDING 9 /* We are waiting for this ordered extent to
-				  * complete in the current transaction. */
-#define BTRFS_ORDERED_REGULAR 10 /* Regular IO for COW */
+enum {
+	/* set when all the pages are written */
+	BTRFS_ORDERED_IO_DONE,
+	/* set when removed from the tree */
+	BTRFS_ORDERED_COMPLETE,
+	/* set when we want to write in place */
+	BTRFS_ORDERED_NOCOW,
+	/* writing a zlib compressed extent */
+	BTRFS_ORDERED_COMPRESSED,
+	/* set when writing to preallocated extent */
+	BTRFS_ORDERED_PREALLOC,
+	/* set when we're doing DIO with this extent */
+	BTRFS_ORDERED_DIRECT,
+	/* We had an io error when writing this out */
+	BTRFS_ORDERED_IOERR,
+	/*
+	 * indicates whether this ordered extent has done its due diligence in
+	 * updating the isize
+	 */
+	BTRFS_ORDERED_UPDATED_ISIZE,
+	/* Set when we have to truncate an extent */
+	BTRFS_ORDERED_TRUNCATED,
+	/* Regular IO for COW */
+	BTRFS_ORDERED_REGULAR,
+};
 
 struct btrfs_ordered_extent {
 	/* logical offset in the file */
@@ -164,8 +167,7 @@
 int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
 				      u64 start, u64 len, u64 disk_len,
 				      int type, int compress_type);
-void btrfs_add_ordered_sum(struct inode *inode,
-			   struct btrfs_ordered_extent *entry,
+void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
 			   struct btrfs_ordered_sum *sum);
 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
 							 u64 file_offset);
@@ -181,11 +183,15 @@
 int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
 				struct btrfs_ordered_extent *ordered);
 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
-			   u32 *sum, int len);
+			   u8 *sum, int len);
 u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
 			       const u64 range_start, const u64 range_len);
 u64 btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
 			      const u64 range_start, const u64 range_len);
+void btrfs_lock_and_flush_ordered_range(struct extent_io_tree *tree,
+					struct btrfs_inode *inode, u64 start,
+					u64 end,
+					struct extent_state **cached_state);
 int __init ordered_data_init(void);
 void __cold ordered_data_exit(void);
 
diff --git a/fs/btrfs/print-tree.c b/fs/btrfs/print-tree.c
index df49931..9cb5057 100644
--- a/fs/btrfs/print-tree.c
+++ b/fs/btrfs/print-tree.c
@@ -153,11 +153,11 @@
 #ifdef CONFIG_BTRFS_DEBUG
 	btrfs_info(eb->fs_info,
 "refs %u lock (w:%d r:%d bw:%d br:%d sw:%d sr:%d) lock_owner %u current %u",
-		   atomic_read(&eb->refs), atomic_read(&eb->write_locks),
+		   atomic_read(&eb->refs), eb->write_locks,
 		   atomic_read(&eb->read_locks),
-		   atomic_read(&eb->blocking_writers),
+		   eb->blocking_writers,
 		   atomic_read(&eb->blocking_readers),
-		   atomic_read(&eb->spinning_writers),
+		   eb->spinning_writers,
 		   atomic_read(&eb->spinning_readers),
 		   eb->lock_owner, current->pid);
 #endif
@@ -189,7 +189,7 @@
 	btrfs_info(fs_info,
 		   "leaf %llu gen %llu total ptrs %d free space %d owner %llu",
 		   btrfs_header_bytenr(l), btrfs_header_generation(l), nr,
-		   btrfs_leaf_free_space(fs_info, l), btrfs_header_owner(l));
+		   btrfs_leaf_free_space(l), btrfs_header_owner(l));
 	print_eb_refs_lock(l);
 	for (i = 0 ; i < nr ; i++) {
 		item = btrfs_item_nr(i);
diff --git a/fs/btrfs/props.c b/fs/btrfs/props.c
index dc61400..1e664e0 100644
--- a/fs/btrfs/props.c
+++ b/fs/btrfs/props.c
@@ -23,36 +23,6 @@
 	int inheritable;
 };
 
-static int prop_compression_validate(const char *value, size_t len);
-static int prop_compression_apply(struct inode *inode,
-				  const char *value,
-				  size_t len);
-static const char *prop_compression_extract(struct inode *inode);
-
-static struct prop_handler prop_handlers[] = {
-	{
-		.xattr_name = XATTR_BTRFS_PREFIX "compression",
-		.validate = prop_compression_validate,
-		.apply = prop_compression_apply,
-		.extract = prop_compression_extract,
-		.inheritable = 1
-	},
-};
-
-void __init btrfs_props_init(void)
-{
-	int i;
-
-	hash_init(prop_handlers_ht);
-
-	for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) {
-		struct prop_handler *p = &prop_handlers[i];
-		u64 h = btrfs_name_hash(p->xattr_name, strlen(p->xattr_name));
-
-		hash_add(prop_handlers_ht, &p->node, h);
-	}
-}
-
 static const struct hlist_head *find_prop_handlers_by_hash(const u64 hash)
 {
 	struct hlist_head *h;
@@ -85,15 +55,9 @@
 	return NULL;
 }
 
-static int __btrfs_set_prop(struct btrfs_trans_handle *trans,
-			    struct inode *inode,
-			    const char *name,
-			    const char *value,
-			    size_t value_len,
-			    int flags)
+int btrfs_validate_prop(const char *name, const char *value, size_t value_len)
 {
 	const struct prop_handler *handler;
-	int ret;
 
 	if (strlen(name) <= XATTR_BTRFS_PREFIX_LEN)
 		return -EINVAL;
@@ -102,9 +66,26 @@
 	if (!handler)
 		return -EINVAL;
 
+	if (value_len == 0)
+		return 0;
+
+	return handler->validate(value, value_len);
+}
+
+int btrfs_set_prop(struct btrfs_trans_handle *trans, struct inode *inode,
+		   const char *name, const char *value, size_t value_len,
+		   int flags)
+{
+	const struct prop_handler *handler;
+	int ret;
+
+	handler = find_prop_handler(name, NULL);
+	if (!handler)
+		return -EINVAL;
+
 	if (value_len == 0) {
 		ret = btrfs_setxattr(trans, inode, handler->xattr_name,
-				       NULL, 0, flags);
+				     NULL, 0, flags);
 		if (ret)
 			return ret;
 
@@ -114,17 +95,14 @@
 		return ret;
 	}
 
-	ret = handler->validate(value, value_len);
-	if (ret)
-		return ret;
-	ret = btrfs_setxattr(trans, inode, handler->xattr_name,
-			       value, value_len, flags);
+	ret = btrfs_setxattr(trans, inode, handler->xattr_name, value,
+			     value_len, flags);
 	if (ret)
 		return ret;
 	ret = handler->apply(inode, value, value_len);
 	if (ret) {
-		btrfs_setxattr(trans, inode, handler->xattr_name,
-				 NULL, 0, flags);
+		btrfs_setxattr(trans, inode, handler->xattr_name, NULL,
+			       0, flags);
 		return ret;
 	}
 
@@ -133,15 +111,6 @@
 	return 0;
 }
 
-int btrfs_set_prop(struct inode *inode,
-		   const char *name,
-		   const char *value,
-		   size_t value_len,
-		   int flags)
-{
-	return __btrfs_set_prop(NULL, inode, name, value, value_len, flags);
-}
-
 static int iterate_object_props(struct btrfs_root *root,
 				struct btrfs_path *path,
 				u64 objectid,
@@ -283,6 +252,74 @@
 	return ret;
 }
 
+static int prop_compression_validate(const char *value, size_t len)
+{
+	if (!value)
+		return 0;
+
+	if (btrfs_compress_is_valid_type(value, len))
+		return 0;
+
+	return -EINVAL;
+}
+
+static int prop_compression_apply(struct inode *inode, const char *value,
+				  size_t len)
+{
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	int type;
+
+	if (len == 0) {
+		BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
+		BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
+		BTRFS_I(inode)->prop_compress = BTRFS_COMPRESS_NONE;
+
+		return 0;
+	}
+
+	if (!strncmp("lzo", value, 3)) {
+		type = BTRFS_COMPRESS_LZO;
+		btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
+	} else if (!strncmp("zlib", value, 4)) {
+		type = BTRFS_COMPRESS_ZLIB;
+	} else if (!strncmp("zstd", value, 4)) {
+		type = BTRFS_COMPRESS_ZSTD;
+		btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
+	} else {
+		return -EINVAL;
+	}
+
+	BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
+	BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
+	BTRFS_I(inode)->prop_compress = type;
+
+	return 0;
+}
+
+static const char *prop_compression_extract(struct inode *inode)
+{
+	switch (BTRFS_I(inode)->prop_compress) {
+	case BTRFS_COMPRESS_ZLIB:
+	case BTRFS_COMPRESS_LZO:
+	case BTRFS_COMPRESS_ZSTD:
+		return btrfs_compress_type2str(BTRFS_I(inode)->prop_compress);
+	default:
+		break;
+	}
+
+	return NULL;
+}
+
+static struct prop_handler prop_handlers[] = {
+	{
+		.xattr_name = XATTR_BTRFS_PREFIX "compression",
+		.validate = prop_compression_validate,
+		.apply = prop_compression_apply,
+		.extract = prop_compression_extract,
+		.inheritable = 1
+	},
+};
+
 static int inherit_props(struct btrfs_trans_handle *trans,
 			 struct inode *inode,
 			 struct inode *parent)
@@ -291,6 +328,7 @@
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	int ret;
 	int i;
+	bool need_reserve = false;
 
 	if (!test_bit(BTRFS_INODE_HAS_PROPS,
 		      &BTRFS_I(parent)->runtime_flags))
@@ -299,7 +337,7 @@
 	for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) {
 		const struct prop_handler *h = &prop_handlers[i];
 		const char *value;
-		u64 num_bytes;
+		u64 num_bytes = 0;
 
 		if (!h->inheritable)
 			continue;
@@ -308,20 +346,51 @@
 		if (!value)
 			continue;
 
-		num_bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
-		ret = btrfs_block_rsv_add(root, trans->block_rsv,
-					  num_bytes, BTRFS_RESERVE_NO_FLUSH);
+		/*
+		 * This is not strictly necessary as the property should be
+		 * valid, but in case it isn't, don't propagate it futher.
+		 */
+		ret = h->validate(value, strlen(value));
 		if (ret)
-			goto out;
-		ret = __btrfs_set_prop(trans, inode, h->xattr_name,
-				       value, strlen(value), 0);
-		btrfs_block_rsv_release(fs_info, trans->block_rsv, num_bytes);
-		if (ret)
-			goto out;
+			continue;
+
+		/*
+		 * Currently callers should be reserving 1 item for properties,
+		 * since we only have 1 property that we currently support.  If
+		 * we add more in the future we need to try and reserve more
+		 * space for them.  But we should also revisit how we do space
+		 * reservations if we do add more properties in the future.
+		 */
+		if (need_reserve) {
+			num_bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
+			ret = btrfs_block_rsv_add(root, trans->block_rsv,
+					num_bytes, BTRFS_RESERVE_NO_FLUSH);
+			if (ret)
+				return ret;
+		}
+
+		ret = btrfs_setxattr(trans, inode, h->xattr_name, value,
+				     strlen(value), 0);
+		if (!ret) {
+			ret = h->apply(inode, value, strlen(value));
+			if (ret)
+				btrfs_setxattr(trans, inode, h->xattr_name,
+					       NULL, 0, 0);
+			else
+				set_bit(BTRFS_INODE_HAS_PROPS,
+					&BTRFS_I(inode)->runtime_flags);
+		}
+
+		if (need_reserve) {
+			btrfs_block_rsv_release(fs_info, trans->block_rsv,
+					num_bytes);
+			if (ret)
+				return ret;
+		}
+		need_reserve = true;
 	}
-	ret = 0;
-out:
-	return ret;
+
+	return 0;
 }
 
 int btrfs_inode_inherit_props(struct btrfs_trans_handle *trans,
@@ -364,64 +433,17 @@
 	return ret;
 }
 
-static int prop_compression_validate(const char *value, size_t len)
+void __init btrfs_props_init(void)
 {
-	if (!strncmp("lzo", value, len))
-		return 0;
-	else if (!strncmp("zlib", value, len))
-		return 0;
-	else if (!strncmp("zstd", value, len))
-		return 0;
+	int i;
 
-	return -EINVAL;
-}
+	hash_init(prop_handlers_ht);
 
-static int prop_compression_apply(struct inode *inode,
-				  const char *value,
-				  size_t len)
-{
-	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
-	int type;
+	for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) {
+		struct prop_handler *p = &prop_handlers[i];
+		u64 h = btrfs_name_hash(p->xattr_name, strlen(p->xattr_name));
 
-	if (len == 0) {
-		BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
-		BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
-		BTRFS_I(inode)->prop_compress = BTRFS_COMPRESS_NONE;
-
-		return 0;
+		hash_add(prop_handlers_ht, &p->node, h);
 	}
-
-	if (!strncmp("lzo", value, 3)) {
-		type = BTRFS_COMPRESS_LZO;
-		btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
-	} else if (!strncmp("zlib", value, 4)) {
-		type = BTRFS_COMPRESS_ZLIB;
-	} else if (!strncmp("zstd", value, len)) {
-		type = BTRFS_COMPRESS_ZSTD;
-		btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
-	} else {
-		return -EINVAL;
-	}
-
-	BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
-	BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
-	BTRFS_I(inode)->prop_compress = type;
-
-	return 0;
 }
 
-static const char *prop_compression_extract(struct inode *inode)
-{
-	switch (BTRFS_I(inode)->prop_compress) {
-	case BTRFS_COMPRESS_ZLIB:
-	case BTRFS_COMPRESS_LZO:
-	case BTRFS_COMPRESS_ZSTD:
-		return btrfs_compress_type2str(BTRFS_I(inode)->prop_compress);
-	default:
-		break;
-	}
-
-	return NULL;
-}
-
-
diff --git a/fs/btrfs/props.h b/fs/btrfs/props.h
index 618815b..40b2c65 100644
--- a/fs/btrfs/props.h
+++ b/fs/btrfs/props.h
@@ -10,11 +10,10 @@
 
 void __init btrfs_props_init(void);
 
-int btrfs_set_prop(struct inode *inode,
-		   const char *name,
-		   const char *value,
-		   size_t value_len,
+int btrfs_set_prop(struct btrfs_trans_handle *trans, struct inode *inode,
+		   const char *name, const char *value, size_t value_len,
 		   int flags);
+int btrfs_validate_prop(const char *name, const char *value, size_t value_len);
 
 int btrfs_load_inode_props(struct inode *inode, struct btrfs_path *path);
 
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index ff43466..3ad1516 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -21,7 +21,7 @@
 #include "backref.h"
 #include "extent_io.h"
 #include "qgroup.h"
-
+#include "block-group.h"
 
 /* TODO XXX FIXME
  *  - subvol delete -> delete when ref goes to 0? delete limits also?
@@ -30,7 +30,7 @@
  *  - sync
  *  - copy also limits on subvol creation
  *  - limit
- *  - caches fuer ulists
+ *  - caches for ulists
  *  - performance benchmarks
  *  - check all ioctl parameters
  */
@@ -522,7 +522,7 @@
 		__del_qgroup_rb(qgroup);
 	}
 	/*
-	 * we call btrfs_free_qgroup_config() when umounting
+	 * We call btrfs_free_qgroup_config() when unmounting
 	 * filesystem and disabling quota, so we set qgroup_ulist
 	 * to be null here to avoid double free.
 	 */
@@ -894,6 +894,12 @@
 	if (fs_info->quota_root)
 		goto out;
 
+	fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
+	if (!fs_info->qgroup_ulist) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
 	/*
 	 * 1 for quota root item
 	 * 1 for BTRFS_QGROUP_STATUS item
@@ -909,18 +915,10 @@
 		goto out;
 	}
 
-	fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
-	if (!fs_info->qgroup_ulist) {
-		ret = -ENOMEM;
-		btrfs_abort_transaction(trans, ret);
-		goto out;
-	}
-
 	/*
 	 * initially create the quota tree
 	 */
-	quota_root = btrfs_create_tree(trans, fs_info,
-				       BTRFS_QUOTA_TREE_OBJECTID);
+	quota_root = btrfs_create_tree(trans, BTRFS_QUOTA_TREE_OBJECTID);
 	if (IS_ERR(quota_root)) {
 		ret =  PTR_ERR(quota_root);
 		btrfs_abort_transaction(trans, ret);
@@ -1013,16 +1011,22 @@
 		btrfs_abort_transaction(trans, ret);
 		goto out_free_path;
 	}
-	spin_lock(&fs_info->qgroup_lock);
-	fs_info->quota_root = quota_root;
-	set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
-	spin_unlock(&fs_info->qgroup_lock);
 
 	ret = btrfs_commit_transaction(trans);
 	trans = NULL;
 	if (ret)
 		goto out_free_path;
 
+	/*
+	 * Set quota enabled flag after committing the transaction, to avoid
+	 * deadlocks on fs_info->qgroup_ioctl_lock with concurrent snapshot
+	 * creation.
+	 */
+	spin_lock(&fs_info->qgroup_lock);
+	fs_info->quota_root = quota_root;
+	set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
+	spin_unlock(&fs_info->qgroup_lock);
+
 	ret = qgroup_rescan_init(fs_info, 0, 1);
 	if (!ret) {
 	        qgroup_rescan_zero_tracking(fs_info);
@@ -1096,7 +1100,7 @@
 	list_del(&quota_root->dirty_list);
 
 	btrfs_tree_lock(quota_root->node);
-	clean_tree_block(fs_info, quota_root->node);
+	btrfs_clean_tree_block(quota_root->node);
 	btrfs_tree_unlock(quota_root->node);
 	btrfs_free_tree_block(trans, quota_root, quota_root->node, 0, 1);
 
@@ -1122,7 +1126,7 @@
  * The easy accounting, we're updating qgroup relationship whose child qgroup
  * only has exclusive extents.
  *
- * In this case, all exclsuive extents will also be exlusive for parent, so
+ * In this case, all exclusive extents will also be exclusive for parent, so
  * excl/rfer just get added/removed.
  *
  * So is qgroup reservation space, which should also be added/removed to
@@ -1308,8 +1312,9 @@
 	struct btrfs_qgroup *member;
 	struct btrfs_qgroup_list *list;
 	struct ulist *tmp;
+	bool found = false;
 	int ret = 0;
-	int err;
+	int ret2;
 
 	tmp = ulist_alloc(GFP_KERNEL);
 	if (!tmp)
@@ -1323,28 +1328,39 @@
 
 	member = find_qgroup_rb(fs_info, src);
 	parent = find_qgroup_rb(fs_info, dst);
-	if (!member || !parent) {
-		ret = -EINVAL;
-		goto out;
-	}
+	/*
+	 * The parent/member pair doesn't exist, then try to delete the dead
+	 * relation items only.
+	 */
+	if (!member || !parent)
+		goto delete_item;
 
 	/* check if such qgroup relation exist firstly */
 	list_for_each_entry(list, &member->groups, next_group) {
-		if (list->group == parent)
-			goto exist;
+		if (list->group == parent) {
+			found = true;
+			break;
+		}
 	}
-	ret = -ENOENT;
-	goto out;
-exist:
-	ret = del_qgroup_relation_item(trans, src, dst);
-	err = del_qgroup_relation_item(trans, dst, src);
-	if (err && !ret)
-		ret = err;
 
-	spin_lock(&fs_info->qgroup_lock);
-	del_relation_rb(fs_info, src, dst);
-	ret = quick_update_accounting(fs_info, tmp, src, dst, -1);
-	spin_unlock(&fs_info->qgroup_lock);
+delete_item:
+	ret = del_qgroup_relation_item(trans, src, dst);
+	if (ret < 0 && ret != -ENOENT)
+		goto out;
+	ret2 = del_qgroup_relation_item(trans, dst, src);
+	if (ret2 < 0 && ret2 != -ENOENT)
+		goto out;
+
+	/* At least one deletion succeeded, return 0 */
+	if (!ret || !ret2)
+		ret = 0;
+
+	if (found) {
+		spin_lock(&fs_info->qgroup_lock);
+		del_relation_rb(fs_info, src, dst);
+		ret = quick_update_accounting(fs_info, tmp, src, dst, -1);
+		spin_unlock(&fs_info->qgroup_lock);
+	}
 out:
 	ulist_free(tmp);
 	return ret;
@@ -1416,13 +1432,14 @@
 	if (!qgroup) {
 		ret = -ENOENT;
 		goto out;
-	} else {
-		/* check if there are no children of this qgroup */
-		if (!list_empty(&qgroup->members)) {
-			ret = -EBUSY;
-			goto out;
-		}
 	}
+
+	/* Check if there are no children of this qgroup */
+	if (!list_empty(&qgroup->members)) {
+		ret = -EBUSY;
+		goto out;
+	}
+
 	ret = del_qgroup_item(trans, qgroupid);
 	if (ret && ret != -ENOENT)
 		goto out;
@@ -1539,12 +1556,18 @@
 		parent_node = *p;
 		entry = rb_entry(parent_node, struct btrfs_qgroup_extent_record,
 				 node);
-		if (bytenr < entry->bytenr)
+		if (bytenr < entry->bytenr) {
 			p = &(*p)->rb_left;
-		else if (bytenr > entry->bytenr)
+		} else if (bytenr > entry->bytenr) {
 			p = &(*p)->rb_right;
-		else
+		} else {
+			if (record->data_rsv && !entry->data_rsv) {
+				entry->data_rsv = record->data_rsv;
+				entry->data_rsv_refroot =
+					record->data_rsv_refroot;
+			}
 			return 1;
+		}
 	}
 
 	rb_link_node(&record->node, parent_node, p);
@@ -1590,7 +1613,7 @@
 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)
 	    || bytenr == 0 || num_bytes == 0)
 		return 0;
-	record = kmalloc(sizeof(*record), gfp_flag);
+	record = kzalloc(sizeof(*record), gfp_flag);
 	if (!record)
 		return -ENOMEM;
 
@@ -1712,6 +1735,357 @@
 	return 0;
 }
 
+/*
+ * Helper function to trace a subtree tree block swap.
+ *
+ * The swap will happen in highest tree block, but there may be a lot of
+ * tree blocks involved.
+ *
+ * For example:
+ *  OO = Old tree blocks
+ *  NN = New tree blocks allocated during balance
+ *
+ *           File tree (257)                  Reloc tree for 257
+ * L2              OO                                NN
+ *               /    \                            /    \
+ * L1          OO      OO (a)                    OO      NN (a)
+ *            / \     / \                       / \     / \
+ * L0       OO   OO OO   OO                   OO   OO NN   NN
+ *                  (b)  (c)                          (b)  (c)
+ *
+ * When calling qgroup_trace_extent_swap(), we will pass:
+ * @src_eb = OO(a)
+ * @dst_path = [ nodes[1] = NN(a), nodes[0] = NN(c) ]
+ * @dst_level = 0
+ * @root_level = 1
+ *
+ * In that case, qgroup_trace_extent_swap() will search from OO(a) to
+ * reach OO(c), then mark both OO(c) and NN(c) as qgroup dirty.
+ *
+ * The main work of qgroup_trace_extent_swap() can be split into 3 parts:
+ *
+ * 1) Tree search from @src_eb
+ *    It should acts as a simplified btrfs_search_slot().
+ *    The key for search can be extracted from @dst_path->nodes[dst_level]
+ *    (first key).
+ *
+ * 2) Mark the final tree blocks in @src_path and @dst_path qgroup dirty
+ *    NOTE: In above case, OO(a) and NN(a) won't be marked qgroup dirty.
+ *    They should be marked during previous (@dst_level = 1) iteration.
+ *
+ * 3) Mark file extents in leaves dirty
+ *    We don't have good way to pick out new file extents only.
+ *    So we still follow the old method by scanning all file extents in
+ *    the leave.
+ *
+ * This function can free us from keeping two paths, thus later we only need
+ * to care about how to iterate all new tree blocks in reloc tree.
+ */
+static int qgroup_trace_extent_swap(struct btrfs_trans_handle* trans,
+				    struct extent_buffer *src_eb,
+				    struct btrfs_path *dst_path,
+				    int dst_level, int root_level,
+				    bool trace_leaf)
+{
+	struct btrfs_key key;
+	struct btrfs_path *src_path;
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	u32 nodesize = fs_info->nodesize;
+	int cur_level = root_level;
+	int ret;
+
+	BUG_ON(dst_level > root_level);
+	/* Level mismatch */
+	if (btrfs_header_level(src_eb) != root_level)
+		return -EINVAL;
+
+	src_path = btrfs_alloc_path();
+	if (!src_path) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	if (dst_level)
+		btrfs_node_key_to_cpu(dst_path->nodes[dst_level], &key, 0);
+	else
+		btrfs_item_key_to_cpu(dst_path->nodes[dst_level], &key, 0);
+
+	/* For src_path */
+	extent_buffer_get(src_eb);
+	src_path->nodes[root_level] = src_eb;
+	src_path->slots[root_level] = dst_path->slots[root_level];
+	src_path->locks[root_level] = 0;
+
+	/* A simplified version of btrfs_search_slot() */
+	while (cur_level >= dst_level) {
+		struct btrfs_key src_key;
+		struct btrfs_key dst_key;
+
+		if (src_path->nodes[cur_level] == NULL) {
+			struct btrfs_key first_key;
+			struct extent_buffer *eb;
+			int parent_slot;
+			u64 child_gen;
+			u64 child_bytenr;
+
+			eb = src_path->nodes[cur_level + 1];
+			parent_slot = src_path->slots[cur_level + 1];
+			child_bytenr = btrfs_node_blockptr(eb, parent_slot);
+			child_gen = btrfs_node_ptr_generation(eb, parent_slot);
+			btrfs_node_key_to_cpu(eb, &first_key, parent_slot);
+
+			eb = read_tree_block(fs_info, child_bytenr, child_gen,
+					     cur_level, &first_key);
+			if (IS_ERR(eb)) {
+				ret = PTR_ERR(eb);
+				goto out;
+			} else if (!extent_buffer_uptodate(eb)) {
+				free_extent_buffer(eb);
+				ret = -EIO;
+				goto out;
+			}
+
+			src_path->nodes[cur_level] = eb;
+
+			btrfs_tree_read_lock(eb);
+			btrfs_set_lock_blocking_read(eb);
+			src_path->locks[cur_level] = BTRFS_READ_LOCK_BLOCKING;
+		}
+
+		src_path->slots[cur_level] = dst_path->slots[cur_level];
+		if (cur_level) {
+			btrfs_node_key_to_cpu(dst_path->nodes[cur_level],
+					&dst_key, dst_path->slots[cur_level]);
+			btrfs_node_key_to_cpu(src_path->nodes[cur_level],
+					&src_key, src_path->slots[cur_level]);
+		} else {
+			btrfs_item_key_to_cpu(dst_path->nodes[cur_level],
+					&dst_key, dst_path->slots[cur_level]);
+			btrfs_item_key_to_cpu(src_path->nodes[cur_level],
+					&src_key, src_path->slots[cur_level]);
+		}
+		/* Content mismatch, something went wrong */
+		if (btrfs_comp_cpu_keys(&dst_key, &src_key)) {
+			ret = -ENOENT;
+			goto out;
+		}
+		cur_level--;
+	}
+
+	/*
+	 * Now both @dst_path and @src_path have been populated, record the tree
+	 * blocks for qgroup accounting.
+	 */
+	ret = btrfs_qgroup_trace_extent(trans, src_path->nodes[dst_level]->start,
+			nodesize, GFP_NOFS);
+	if (ret < 0)
+		goto out;
+	ret = btrfs_qgroup_trace_extent(trans,
+			dst_path->nodes[dst_level]->start,
+			nodesize, GFP_NOFS);
+	if (ret < 0)
+		goto out;
+
+	/* Record leaf file extents */
+	if (dst_level == 0 && trace_leaf) {
+		ret = btrfs_qgroup_trace_leaf_items(trans, src_path->nodes[0]);
+		if (ret < 0)
+			goto out;
+		ret = btrfs_qgroup_trace_leaf_items(trans, dst_path->nodes[0]);
+	}
+out:
+	btrfs_free_path(src_path);
+	return ret;
+}
+
+/*
+ * Helper function to do recursive generation-aware depth-first search, to
+ * locate all new tree blocks in a subtree of reloc tree.
+ *
+ * E.g. (OO = Old tree blocks, NN = New tree blocks, whose gen == last_snapshot)
+ *         reloc tree
+ * L2         NN (a)
+ *          /    \
+ * L1    OO        NN (b)
+ *      /  \      /  \
+ * L0  OO  OO    OO  NN
+ *               (c) (d)
+ * If we pass:
+ * @dst_path = [ nodes[1] = NN(b), nodes[0] = NULL ],
+ * @cur_level = 1
+ * @root_level = 1
+ *
+ * We will iterate through tree blocks NN(b), NN(d) and info qgroup to trace
+ * above tree blocks along with their counter parts in file tree.
+ * While during search, old tree blocks OO(c) will be skipped as tree block swap
+ * won't affect OO(c).
+ */
+static int qgroup_trace_new_subtree_blocks(struct btrfs_trans_handle* trans,
+					   struct extent_buffer *src_eb,
+					   struct btrfs_path *dst_path,
+					   int cur_level, int root_level,
+					   u64 last_snapshot, bool trace_leaf)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct extent_buffer *eb;
+	bool need_cleanup = false;
+	int ret = 0;
+	int i;
+
+	/* Level sanity check */
+	if (cur_level < 0 || cur_level >= BTRFS_MAX_LEVEL - 1 ||
+	    root_level < 0 || root_level >= BTRFS_MAX_LEVEL - 1 ||
+	    root_level < cur_level) {
+		btrfs_err_rl(fs_info,
+			"%s: bad levels, cur_level=%d root_level=%d",
+			__func__, cur_level, root_level);
+		return -EUCLEAN;
+	}
+
+	/* Read the tree block if needed */
+	if (dst_path->nodes[cur_level] == NULL) {
+		struct btrfs_key first_key;
+		int parent_slot;
+		u64 child_gen;
+		u64 child_bytenr;
+
+		/*
+		 * dst_path->nodes[root_level] must be initialized before
+		 * calling this function.
+		 */
+		if (cur_level == root_level) {
+			btrfs_err_rl(fs_info,
+	"%s: dst_path->nodes[%d] not initialized, root_level=%d cur_level=%d",
+				__func__, root_level, root_level, cur_level);
+			return -EUCLEAN;
+		}
+
+		/*
+		 * We need to get child blockptr/gen from parent before we can
+		 * read it.
+		  */
+		eb = dst_path->nodes[cur_level + 1];
+		parent_slot = dst_path->slots[cur_level + 1];
+		child_bytenr = btrfs_node_blockptr(eb, parent_slot);
+		child_gen = btrfs_node_ptr_generation(eb, parent_slot);
+		btrfs_node_key_to_cpu(eb, &first_key, parent_slot);
+
+		/* This node is old, no need to trace */
+		if (child_gen < last_snapshot)
+			goto out;
+
+		eb = read_tree_block(fs_info, child_bytenr, child_gen,
+				     cur_level, &first_key);
+		if (IS_ERR(eb)) {
+			ret = PTR_ERR(eb);
+			goto out;
+		} else if (!extent_buffer_uptodate(eb)) {
+			free_extent_buffer(eb);
+			ret = -EIO;
+			goto out;
+		}
+
+		dst_path->nodes[cur_level] = eb;
+		dst_path->slots[cur_level] = 0;
+
+		btrfs_tree_read_lock(eb);
+		btrfs_set_lock_blocking_read(eb);
+		dst_path->locks[cur_level] = BTRFS_READ_LOCK_BLOCKING;
+		need_cleanup = true;
+	}
+
+	/* Now record this tree block and its counter part for qgroups */
+	ret = qgroup_trace_extent_swap(trans, src_eb, dst_path, cur_level,
+				       root_level, trace_leaf);
+	if (ret < 0)
+		goto cleanup;
+
+	eb = dst_path->nodes[cur_level];
+
+	if (cur_level > 0) {
+		/* Iterate all child tree blocks */
+		for (i = 0; i < btrfs_header_nritems(eb); i++) {
+			/* Skip old tree blocks as they won't be swapped */
+			if (btrfs_node_ptr_generation(eb, i) < last_snapshot)
+				continue;
+			dst_path->slots[cur_level] = i;
+
+			/* Recursive call (at most 7 times) */
+			ret = qgroup_trace_new_subtree_blocks(trans, src_eb,
+					dst_path, cur_level - 1, root_level,
+					last_snapshot, trace_leaf);
+			if (ret < 0)
+				goto cleanup;
+		}
+	}
+
+cleanup:
+	if (need_cleanup) {
+		/* Clean up */
+		btrfs_tree_unlock_rw(dst_path->nodes[cur_level],
+				     dst_path->locks[cur_level]);
+		free_extent_buffer(dst_path->nodes[cur_level]);
+		dst_path->nodes[cur_level] = NULL;
+		dst_path->slots[cur_level] = 0;
+		dst_path->locks[cur_level] = 0;
+	}
+out:
+	return ret;
+}
+
+static int qgroup_trace_subtree_swap(struct btrfs_trans_handle *trans,
+				struct extent_buffer *src_eb,
+				struct extent_buffer *dst_eb,
+				u64 last_snapshot, bool trace_leaf)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_path *dst_path = NULL;
+	int level;
+	int ret;
+
+	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
+		return 0;
+
+	/* Wrong parameter order */
+	if (btrfs_header_generation(src_eb) > btrfs_header_generation(dst_eb)) {
+		btrfs_err_rl(fs_info,
+		"%s: bad parameter order, src_gen=%llu dst_gen=%llu", __func__,
+			     btrfs_header_generation(src_eb),
+			     btrfs_header_generation(dst_eb));
+		return -EUCLEAN;
+	}
+
+	if (!extent_buffer_uptodate(src_eb) || !extent_buffer_uptodate(dst_eb)) {
+		ret = -EIO;
+		goto out;
+	}
+
+	level = btrfs_header_level(dst_eb);
+	dst_path = btrfs_alloc_path();
+	if (!dst_path) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	/* For dst_path */
+	extent_buffer_get(dst_eb);
+	dst_path->nodes[level] = dst_eb;
+	dst_path->slots[level] = 0;
+	dst_path->locks[level] = 0;
+
+	/* Do the generation aware breadth-first search */
+	ret = qgroup_trace_new_subtree_blocks(trans, src_eb, dst_path, level,
+					      level, last_snapshot, trace_leaf);
+	if (ret < 0)
+		goto out;
+	ret = 0;
+
+out:
+	btrfs_free_path(dst_path);
+	if (ret < 0)
+		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
+	return ret;
+}
+
 int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
 			       struct extent_buffer *root_eb,
 			       u64 root_gen, int root_level)
@@ -1790,7 +2164,7 @@
 			path->slots[level] = 0;
 
 			btrfs_tree_read_lock(eb);
-			btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
+			btrfs_set_lock_blocking_read(eb);
 			path->locks[level] = BTRFS_READ_LOCK_BLOCKING;
 
 			ret = btrfs_qgroup_trace_extent(trans, child_bytenr,
@@ -2132,6 +2506,7 @@
 	struct btrfs_delayed_ref_root *delayed_refs;
 	struct ulist *new_roots = NULL;
 	struct rb_node *node;
+	u64 num_dirty_extents = 0;
 	u64 qgroup_to_skip;
 	int ret = 0;
 
@@ -2141,6 +2516,7 @@
 		record = rb_entry(node, struct btrfs_qgroup_extent_record,
 				  node);
 
+		num_dirty_extents++;
 		trace_btrfs_qgroup_account_extents(fs_info, record);
 
 		if (!ret) {
@@ -2157,6 +2533,11 @@
 					goto cleanup;
 			}
 
+			/* Free the reserved data space */
+			btrfs_qgroup_free_refroot(fs_info,
+					record->data_rsv_refroot,
+					record->data_rsv,
+					BTRFS_QGROUP_RSV_DATA);
 			/*
 			 * Use SEQ_LAST as time_seq to do special search, which
 			 * doesn't lock tree or delayed_refs and search current
@@ -2186,6 +2567,8 @@
 		kfree(record);
 
 	}
+	trace_qgroup_num_dirty_extents(fs_info, trans->transid,
+				       num_dirty_extents);
 	return ret;
 }
 
@@ -2243,6 +2626,7 @@
 	int ret = 0;
 	int i;
 	u64 *i_qgroups;
+	bool committing = false;
 	struct btrfs_fs_info *fs_info = trans->fs_info;
 	struct btrfs_root *quota_root;
 	struct btrfs_qgroup *srcgroup;
@@ -2250,7 +2634,25 @@
 	u32 level_size = 0;
 	u64 nums;
 
-	mutex_lock(&fs_info->qgroup_ioctl_lock);
+	/*
+	 * There are only two callers of this function.
+	 *
+	 * One in create_subvol() in the ioctl context, which needs to hold
+	 * the qgroup_ioctl_lock.
+	 *
+	 * The other one in create_pending_snapshot() where no other qgroup
+	 * code can modify the fs as they all need to either start a new trans
+	 * or hold a trans handler, thus we don't need to hold
+	 * qgroup_ioctl_lock.
+	 * This would avoid long and complex lock chain and make lockdep happy.
+	 */
+	spin_lock(&fs_info->trans_lock);
+	if (trans->transaction->state == TRANS_STATE_COMMIT_DOING)
+		committing = true;
+	spin_unlock(&fs_info->trans_lock);
+
+	if (!committing)
+		mutex_lock(&fs_info->qgroup_ioctl_lock);
 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
 		goto out;
 
@@ -2414,23 +2816,23 @@
 unlock:
 	spin_unlock(&fs_info->qgroup_lock);
 out:
-	mutex_unlock(&fs_info->qgroup_ioctl_lock);
+	if (!committing)
+		mutex_unlock(&fs_info->qgroup_ioctl_lock);
 	return ret;
 }
 
 /*
  * Two limits to commit transaction in advance.
  *
- * For RATIO, it will be 1/RATIO of the remaining limit
- * (excluding data and prealloc meta) as threshold.
+ * For RATIO, it will be 1/RATIO of the remaining limit as threshold.
  * For SIZE, it will be in byte unit as threshold.
  */
-#define QGROUP_PERTRANS_RATIO		32
-#define QGROUP_PERTRANS_SIZE		SZ_32M
+#define QGROUP_FREE_RATIO		32
+#define QGROUP_FREE_SIZE		SZ_32M
 static bool qgroup_check_limits(struct btrfs_fs_info *fs_info,
 				const struct btrfs_qgroup *qg, u64 num_bytes)
 {
-	u64 limit;
+	u64 free;
 	u64 threshold;
 
 	if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
@@ -2449,20 +2851,21 @@
 	 */
 	if ((qg->lim_flags & (BTRFS_QGROUP_LIMIT_MAX_RFER |
 			      BTRFS_QGROUP_LIMIT_MAX_EXCL))) {
-		if (qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL)
-			limit = qg->max_excl;
-		else
-			limit = qg->max_rfer;
-		threshold = (limit - qg->rsv.values[BTRFS_QGROUP_RSV_DATA] -
-			    qg->rsv.values[BTRFS_QGROUP_RSV_META_PREALLOC]) /
-			    QGROUP_PERTRANS_RATIO;
-		threshold = min_t(u64, threshold, QGROUP_PERTRANS_SIZE);
+		if (qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) {
+			free = qg->max_excl - qgroup_rsv_total(qg) - qg->excl;
+			threshold = min_t(u64, qg->max_excl / QGROUP_FREE_RATIO,
+					  QGROUP_FREE_SIZE);
+		} else {
+			free = qg->max_rfer - qgroup_rsv_total(qg) - qg->rfer;
+			threshold = min_t(u64, qg->max_rfer / QGROUP_FREE_RATIO,
+					  QGROUP_FREE_SIZE);
+		}
 
 		/*
 		 * Use transaction_kthread to commit transaction, so we no
 		 * longer need to bother nested transaction nor lock context.
 		 */
-		if (qg->rsv.values[BTRFS_QGROUP_RSV_META_PERTRANS] > threshold)
+		if (free < threshold)
 			btrfs_commit_transaction_locksafe(fs_info);
 	}
 
@@ -2538,7 +2941,6 @@
 
 		qg = unode_aux_to_qgroup(unode);
 
-		trace_qgroup_update_reserve(fs_info, qg, num_bytes, type);
 		qgroup_rsv_add(fs_info, qg, num_bytes, type);
 	}
 
@@ -2605,7 +3007,6 @@
 
 		qg = unode_aux_to_qgroup(unode);
 
-		trace_qgroup_update_reserve(fs_info, qg, -(s64)num_bytes, type);
 		qgroup_rsv_release(fs_info, qg, num_bytes, type);
 
 		list_for_each_entry(glist, &qg->groups, next_group) {
@@ -2689,9 +3090,6 @@
 		mutex_unlock(&fs_info->qgroup_rescan_lock);
 		goto out;
 	}
-	extent_buffer_get(scratch_leaf);
-	btrfs_tree_read_lock(scratch_leaf);
-	btrfs_set_lock_blocking_rw(scratch_leaf, BTRFS_READ_LOCK);
 	slot = path->slots[0];
 	btrfs_release_path(path);
 	mutex_unlock(&fs_info->qgroup_rescan_lock);
@@ -2717,10 +3115,8 @@
 			goto out;
 	}
 out:
-	if (scratch_leaf) {
-		btrfs_tree_read_unlock_blocking(scratch_leaf);
+	if (scratch_leaf)
 		free_extent_buffer(scratch_leaf);
-	}
 
 	if (done && !ret) {
 		ret = 1;
@@ -2770,9 +3166,6 @@
 	btrfs_free_path(path);
 
 	mutex_lock(&fs_info->qgroup_rescan_lock);
-	if (!btrfs_fs_closing(fs_info))
-		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
-
 	if (err > 0 &&
 	    fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT) {
 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
@@ -2788,16 +3181,30 @@
 	trans = btrfs_start_transaction(fs_info->quota_root, 1);
 	if (IS_ERR(trans)) {
 		err = PTR_ERR(trans);
+		trans = NULL;
 		btrfs_err(fs_info,
 			  "fail to start transaction for status update: %d",
 			  err);
-		goto done;
 	}
-	ret = update_qgroup_status_item(trans);
-	if (ret < 0) {
-		err = ret;
-		btrfs_err(fs_info, "fail to update qgroup status: %d", err);
+
+	mutex_lock(&fs_info->qgroup_rescan_lock);
+	if (!btrfs_fs_closing(fs_info))
+		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
+	if (trans) {
+		ret = update_qgroup_status_item(trans);
+		if (ret < 0) {
+			err = ret;
+			btrfs_err(fs_info, "fail to update qgroup status: %d",
+				  err);
+		}
 	}
+	fs_info->qgroup_rescan_running = false;
+	complete_all(&fs_info->qgroup_rescan_completion);
+	mutex_unlock(&fs_info->qgroup_rescan_lock);
+
+	if (!trans)
+		return;
+
 	btrfs_end_transaction(trans);
 
 	if (btrfs_fs_closing(fs_info)) {
@@ -2808,12 +3215,6 @@
 	} else {
 		btrfs_err(fs_info, "qgroup scan failed with %d", err);
 	}
-
-done:
-	mutex_lock(&fs_info->qgroup_rescan_lock);
-	fs_info->qgroup_rescan_running = false;
-	mutex_unlock(&fs_info->qgroup_rescan_lock);
-	complete_all(&fs_info->qgroup_rescan_completion);
 }
 
 /*
@@ -3006,7 +3407,7 @@
 	int ret;
 
 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &root->fs_info->flags) ||
-	    !is_fstree(root->objectid) || len == 0)
+	    !is_fstree(root->root_key.objectid) || len == 0)
 		return 0;
 
 	/* @reserved parameter is mandatory for qgroup */
@@ -3041,6 +3442,9 @@
 	while ((unode = ulist_next(&reserved->range_changed, &uiter)))
 		clear_extent_bit(&BTRFS_I(inode)->io_tree, unode->val,
 				 unode->aux, EXTENT_QGROUP_RESERVED, 0, 0, NULL);
+	/* Also free data bytes of already reserved one */
+	btrfs_qgroup_free_refroot(root->fs_info, root->root_key.objectid,
+				  orig_reserved, BTRFS_QGROUP_RSV_DATA);
 	extent_changeset_release(reserved);
 	return ret;
 }
@@ -3085,14 +3489,14 @@
 		 * EXTENT_QGROUP_RESERVED, we won't double free.
 		 * So not need to rush.
 		 */
-		ret = clear_record_extent_bits(&BTRFS_I(inode)->io_failure_tree,
+		ret = clear_record_extent_bits(&BTRFS_I(inode)->io_tree,
 				free_start, free_start + free_len - 1,
 				EXTENT_QGROUP_RESERVED, &changeset);
 		if (ret < 0)
 			goto out;
 		freed += changeset.bytes_changed;
 	}
-	btrfs_qgroup_free_refroot(root->fs_info, root->objectid, freed,
+	btrfs_qgroup_free_refroot(root->fs_info, root->root_key.objectid, freed,
 				  BTRFS_QGROUP_RSV_DATA);
 	ret = freed;
 out:
@@ -3128,7 +3532,7 @@
 					changeset.bytes_changed, trace_op);
 	if (free)
 		btrfs_qgroup_free_refroot(BTRFS_I(inode)->root->fs_info,
-				BTRFS_I(inode)->root->objectid,
+				BTRFS_I(inode)->root->root_key.objectid,
 				changeset.bytes_changed, BTRFS_QGROUP_RSV_DATA);
 	ret = changeset.bytes_changed;
 out:
@@ -3221,11 +3625,11 @@
 	int ret;
 
 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
-	    !is_fstree(root->objectid) || num_bytes == 0)
+	    !is_fstree(root->root_key.objectid) || num_bytes == 0)
 		return 0;
 
 	BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
-	trace_qgroup_meta_reserve(root, type, (s64)num_bytes);
+	trace_qgroup_meta_reserve(root, (s64)num_bytes, type);
 	ret = qgroup_reserve(root, num_bytes, enforce, type);
 	if (ret < 0)
 		return ret;
@@ -3246,13 +3650,13 @@
 	struct btrfs_fs_info *fs_info = root->fs_info;
 
 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
-	    !is_fstree(root->objectid))
+	    !is_fstree(root->root_key.objectid))
 		return;
 
 	/* TODO: Update trace point to handle such free */
 	trace_qgroup_meta_free_all_pertrans(root);
 	/* Special value -1 means to free all reserved space */
-	btrfs_qgroup_free_refroot(fs_info, root->objectid, (u64)-1,
+	btrfs_qgroup_free_refroot(fs_info, root->root_key.objectid, (u64)-1,
 				  BTRFS_QGROUP_RSV_META_PERTRANS);
 }
 
@@ -3262,7 +3666,7 @@
 	struct btrfs_fs_info *fs_info = root->fs_info;
 
 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
-	    !is_fstree(root->objectid))
+	    !is_fstree(root->root_key.objectid))
 		return;
 
 	/*
@@ -3272,8 +3676,9 @@
 	 */
 	num_bytes = sub_root_meta_rsv(root, num_bytes, type);
 	BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
-	trace_qgroup_meta_reserve(root, type, -(s64)num_bytes);
-	btrfs_qgroup_free_refroot(fs_info, root->objectid, num_bytes, type);
+	trace_qgroup_meta_reserve(root, -(s64)num_bytes, type);
+	btrfs_qgroup_free_refroot(fs_info, root->root_key.objectid,
+				  num_bytes, type);
 }
 
 static void qgroup_convert_meta(struct btrfs_fs_info *fs_info, u64 ref_root,
@@ -3327,13 +3732,13 @@
 	struct btrfs_fs_info *fs_info = root->fs_info;
 
 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
-	    !is_fstree(root->objectid))
+	    !is_fstree(root->root_key.objectid))
 		return;
 	/* Same as btrfs_qgroup_free_meta_prealloc() */
 	num_bytes = sub_root_meta_rsv(root, num_bytes,
 				      BTRFS_QGROUP_RSV_META_PREALLOC);
 	trace_qgroup_meta_convert(root, num_bytes);
-	qgroup_convert_meta(fs_info, root->objectid, num_bytes);
+	qgroup_convert_meta(fs_info, root->root_key.objectid, num_bytes);
 }
 
 /*
@@ -3360,9 +3765,253 @@
 				inode->i_ino, unode->val, unode->aux);
 		}
 		btrfs_qgroup_free_refroot(BTRFS_I(inode)->root->fs_info,
-				BTRFS_I(inode)->root->objectid,
+				BTRFS_I(inode)->root->root_key.objectid,
 				changeset.bytes_changed, BTRFS_QGROUP_RSV_DATA);
 
 	}
 	extent_changeset_release(&changeset);
 }
+
+void btrfs_qgroup_init_swapped_blocks(
+	struct btrfs_qgroup_swapped_blocks *swapped_blocks)
+{
+	int i;
+
+	spin_lock_init(&swapped_blocks->lock);
+	for (i = 0; i < BTRFS_MAX_LEVEL; i++)
+		swapped_blocks->blocks[i] = RB_ROOT;
+	swapped_blocks->swapped = false;
+}
+
+/*
+ * Delete all swapped blocks record of @root.
+ * Every record here means we skipped a full subtree scan for qgroup.
+ *
+ * Gets called when committing one transaction.
+ */
+void btrfs_qgroup_clean_swapped_blocks(struct btrfs_root *root)
+{
+	struct btrfs_qgroup_swapped_blocks *swapped_blocks;
+	int i;
+
+	swapped_blocks = &root->swapped_blocks;
+
+	spin_lock(&swapped_blocks->lock);
+	if (!swapped_blocks->swapped)
+		goto out;
+	for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
+		struct rb_root *cur_root = &swapped_blocks->blocks[i];
+		struct btrfs_qgroup_swapped_block *entry;
+		struct btrfs_qgroup_swapped_block *next;
+
+		rbtree_postorder_for_each_entry_safe(entry, next, cur_root,
+						     node)
+			kfree(entry);
+		swapped_blocks->blocks[i] = RB_ROOT;
+	}
+	swapped_blocks->swapped = false;
+out:
+	spin_unlock(&swapped_blocks->lock);
+}
+
+/*
+ * Add subtree roots record into @subvol_root.
+ *
+ * @subvol_root:	tree root of the subvolume tree get swapped
+ * @bg:			block group under balance
+ * @subvol_parent/slot:	pointer to the subtree root in subvolume tree
+ * @reloc_parent/slot:	pointer to the subtree root in reloc tree
+ *			BOTH POINTERS ARE BEFORE TREE SWAP
+ * @last_snapshot:	last snapshot generation of the subvolume tree
+ */
+int btrfs_qgroup_add_swapped_blocks(struct btrfs_trans_handle *trans,
+		struct btrfs_root *subvol_root,
+		struct btrfs_block_group_cache *bg,
+		struct extent_buffer *subvol_parent, int subvol_slot,
+		struct extent_buffer *reloc_parent, int reloc_slot,
+		u64 last_snapshot)
+{
+	struct btrfs_fs_info *fs_info = subvol_root->fs_info;
+	struct btrfs_qgroup_swapped_blocks *blocks = &subvol_root->swapped_blocks;
+	struct btrfs_qgroup_swapped_block *block;
+	struct rb_node **cur;
+	struct rb_node *parent = NULL;
+	int level = btrfs_header_level(subvol_parent) - 1;
+	int ret = 0;
+
+	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
+		return 0;
+
+	if (btrfs_node_ptr_generation(subvol_parent, subvol_slot) >
+	    btrfs_node_ptr_generation(reloc_parent, reloc_slot)) {
+		btrfs_err_rl(fs_info,
+		"%s: bad parameter order, subvol_gen=%llu reloc_gen=%llu",
+			__func__,
+			btrfs_node_ptr_generation(subvol_parent, subvol_slot),
+			btrfs_node_ptr_generation(reloc_parent, reloc_slot));
+		return -EUCLEAN;
+	}
+
+	block = kmalloc(sizeof(*block), GFP_NOFS);
+	if (!block) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	/*
+	 * @reloc_parent/slot is still before swap, while @block is going to
+	 * record the bytenr after swap, so we do the swap here.
+	 */
+	block->subvol_bytenr = btrfs_node_blockptr(reloc_parent, reloc_slot);
+	block->subvol_generation = btrfs_node_ptr_generation(reloc_parent,
+							     reloc_slot);
+	block->reloc_bytenr = btrfs_node_blockptr(subvol_parent, subvol_slot);
+	block->reloc_generation = btrfs_node_ptr_generation(subvol_parent,
+							    subvol_slot);
+	block->last_snapshot = last_snapshot;
+	block->level = level;
+
+	/*
+	 * If we have bg == NULL, we're called from btrfs_recover_relocation(),
+	 * no one else can modify tree blocks thus we qgroup will not change
+	 * no matter the value of trace_leaf.
+	 */
+	if (bg && bg->flags & BTRFS_BLOCK_GROUP_DATA)
+		block->trace_leaf = true;
+	else
+		block->trace_leaf = false;
+	btrfs_node_key_to_cpu(reloc_parent, &block->first_key, reloc_slot);
+
+	/* Insert @block into @blocks */
+	spin_lock(&blocks->lock);
+	cur = &blocks->blocks[level].rb_node;
+	while (*cur) {
+		struct btrfs_qgroup_swapped_block *entry;
+
+		parent = *cur;
+		entry = rb_entry(parent, struct btrfs_qgroup_swapped_block,
+				 node);
+
+		if (entry->subvol_bytenr < block->subvol_bytenr) {
+			cur = &(*cur)->rb_left;
+		} else if (entry->subvol_bytenr > block->subvol_bytenr) {
+			cur = &(*cur)->rb_right;
+		} else {
+			if (entry->subvol_generation !=
+					block->subvol_generation ||
+			    entry->reloc_bytenr != block->reloc_bytenr ||
+			    entry->reloc_generation !=
+					block->reloc_generation) {
+				/*
+				 * Duplicated but mismatch entry found.
+				 * Shouldn't happen.
+				 *
+				 * Marking qgroup inconsistent should be enough
+				 * for end users.
+				 */
+				WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
+				ret = -EEXIST;
+			}
+			kfree(block);
+			goto out_unlock;
+		}
+	}
+	rb_link_node(&block->node, parent, cur);
+	rb_insert_color(&block->node, &blocks->blocks[level]);
+	blocks->swapped = true;
+out_unlock:
+	spin_unlock(&blocks->lock);
+out:
+	if (ret < 0)
+		fs_info->qgroup_flags |=
+			BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
+	return ret;
+}
+
+/*
+ * Check if the tree block is a subtree root, and if so do the needed
+ * delayed subtree trace for qgroup.
+ *
+ * This is called during btrfs_cow_block().
+ */
+int btrfs_qgroup_trace_subtree_after_cow(struct btrfs_trans_handle *trans,
+					 struct btrfs_root *root,
+					 struct extent_buffer *subvol_eb)
+{
+	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct btrfs_qgroup_swapped_blocks *blocks = &root->swapped_blocks;
+	struct btrfs_qgroup_swapped_block *block;
+	struct extent_buffer *reloc_eb = NULL;
+	struct rb_node *node;
+	bool found = false;
+	bool swapped = false;
+	int level = btrfs_header_level(subvol_eb);
+	int ret = 0;
+	int i;
+
+	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
+		return 0;
+	if (!is_fstree(root->root_key.objectid) || !root->reloc_root)
+		return 0;
+
+	spin_lock(&blocks->lock);
+	if (!blocks->swapped) {
+		spin_unlock(&blocks->lock);
+		return 0;
+	}
+	node = blocks->blocks[level].rb_node;
+
+	while (node) {
+		block = rb_entry(node, struct btrfs_qgroup_swapped_block, node);
+		if (block->subvol_bytenr < subvol_eb->start) {
+			node = node->rb_left;
+		} else if (block->subvol_bytenr > subvol_eb->start) {
+			node = node->rb_right;
+		} else {
+			found = true;
+			break;
+		}
+	}
+	if (!found) {
+		spin_unlock(&blocks->lock);
+		goto out;
+	}
+	/* Found one, remove it from @blocks first and update blocks->swapped */
+	rb_erase(&block->node, &blocks->blocks[level]);
+	for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
+		if (RB_EMPTY_ROOT(&blocks->blocks[i])) {
+			swapped = true;
+			break;
+		}
+	}
+	blocks->swapped = swapped;
+	spin_unlock(&blocks->lock);
+
+	/* Read out reloc subtree root */
+	reloc_eb = read_tree_block(fs_info, block->reloc_bytenr,
+				   block->reloc_generation, block->level,
+				   &block->first_key);
+	if (IS_ERR(reloc_eb)) {
+		ret = PTR_ERR(reloc_eb);
+		reloc_eb = NULL;
+		goto free_out;
+	}
+	if (!extent_buffer_uptodate(reloc_eb)) {
+		ret = -EIO;
+		goto free_out;
+	}
+
+	ret = qgroup_trace_subtree_swap(trans, reloc_eb, subvol_eb,
+			block->last_snapshot, block->trace_leaf);
+free_out:
+	kfree(block);
+	free_extent_buffer(reloc_eb);
+out:
+	if (ret < 0) {
+		btrfs_err_rl(fs_info,
+			     "failed to account subtree at bytenr %llu: %d",
+			     subvol_eb->start, ret);
+		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
+	}
+	return ret;
+}
diff --git a/fs/btrfs/qgroup.h b/fs/btrfs/qgroup.h
index 4bbcc1e..46ba7bd 100644
--- a/fs/btrfs/qgroup.h
+++ b/fs/btrfs/qgroup.h
@@ -6,6 +6,8 @@
 #ifndef BTRFS_QGROUP_H
 #define BTRFS_QGROUP_H
 
+#include <linux/spinlock.h>
+#include <linux/rbtree.h>
 #include "ulist.h"
 #include "delayed-ref.h"
 
@@ -38,6 +40,66 @@
  */
 
 /*
+ * Special performance optimization for balance.
+ *
+ * For balance, we need to swap subtree of subvolume and reloc trees.
+ * In theory, we need to trace all subtree blocks of both subvolume and reloc
+ * trees, since their owner has changed during such swap.
+ *
+ * However since balance has ensured that both subtrees are containing the
+ * same contents and have the same tree structures, such swap won't cause
+ * qgroup number change.
+ *
+ * But there is a race window between subtree swap and transaction commit,
+ * during that window, if we increase/decrease tree level or merge/split tree
+ * blocks, we still need to trace the original subtrees.
+ *
+ * So for balance, we use a delayed subtree tracing, whose workflow is:
+ *
+ * 1) Record the subtree root block get swapped.
+ *
+ *    During subtree swap:
+ *    O = Old tree blocks
+ *    N = New tree blocks
+ *          reloc tree                     subvolume tree X
+ *             Root                               Root
+ *            /    \                             /    \
+ *          NA     OB                          OA      OB
+ *        /  |     |  \                      /  |      |  \
+ *      NC  ND     OE  OF                   OC  OD     OE  OF
+ *
+ *   In this case, NA and OA are going to be swapped, record (NA, OA) into
+ *   subvolume tree X.
+ *
+ * 2) After subtree swap.
+ *          reloc tree                     subvolume tree X
+ *             Root                               Root
+ *            /    \                             /    \
+ *          OA     OB                          NA      OB
+ *        /  |     |  \                      /  |      |  \
+ *      OC  OD     OE  OF                   NC  ND     OE  OF
+ *
+ * 3a) COW happens for OB
+ *     If we are going to COW tree block OB, we check OB's bytenr against
+ *     tree X's swapped_blocks structure.
+ *     If it doesn't fit any, nothing will happen.
+ *
+ * 3b) COW happens for NA
+ *     Check NA's bytenr against tree X's swapped_blocks, and get a hit.
+ *     Then we do subtree scan on both subtrees OA and NA.
+ *     Resulting 6 tree blocks to be scanned (OA, OC, OD, NA, NC, ND).
+ *
+ *     Then no matter what we do to subvolume tree X, qgroup numbers will
+ *     still be correct.
+ *     Then NA's record gets removed from X's swapped_blocks.
+ *
+ * 4)  Transaction commit
+ *     Any record in X's swapped_blocks gets removed, since there is no
+ *     modification to the swapped subtrees, no need to trigger heavy qgroup
+ *     subtree rescan for them.
+ */
+
+/*
  * Record a dirty extent, and info qgroup to update quota on it
  * TODO: Use kmem cache to alloc it.
  */
@@ -45,9 +107,38 @@
 	struct rb_node node;
 	u64 bytenr;
 	u64 num_bytes;
+
+	/*
+	 * For qgroup reserved data space freeing.
+	 *
+	 * @data_rsv_refroot and @data_rsv will be recorded after
+	 * BTRFS_ADD_DELAYED_EXTENT is called.
+	 * And will be used to free reserved qgroup space at
+	 * transaction commit time.
+	 */
+	u32 data_rsv;		/* reserved data space needs to be freed */
+	u64 data_rsv_refroot;	/* which root the reserved data belongs to */
 	struct ulist *old_roots;
 };
 
+struct btrfs_qgroup_swapped_block {
+	struct rb_node node;
+
+	int level;
+	bool trace_leaf;
+
+	/* bytenr/generation of the tree block in subvolume tree after swap */
+	u64 subvol_bytenr;
+	u64 subvol_generation;
+
+	/* bytenr/generation of the tree block in reloc tree after swap */
+	u64 reloc_bytenr;
+	u64 reloc_generation;
+
+	u64 last_snapshot;
+	struct btrfs_key first_key;
+};
+
 /*
  * Qgroup reservation types:
  *
@@ -70,7 +161,7 @@
  *	be converted into META_PERTRANS.
  */
 enum btrfs_qgroup_rsv_type {
-	BTRFS_QGROUP_RSV_DATA = 0,
+	BTRFS_QGROUP_RSV_DATA,
 	BTRFS_QGROUP_RSV_META_PERTRANS,
 	BTRFS_QGROUP_RSV_META_PREALLOC,
 	BTRFS_QGROUP_RSV_LAST,
@@ -81,10 +172,10 @@
  *
  * Each type should have different reservation behavior.
  * E.g, data follows its io_tree flag modification, while
- * *currently* meta is just reserve-and-clear during transcation.
+ * *currently* meta is just reserve-and-clear during transaction.
  *
  * TODO: Add new type for reservation which can survive transaction commit.
- * Currect metadata reservation behavior is not suitable for such case.
+ * Current metadata reservation behavior is not suitable for such case.
  */
 struct btrfs_qgroup_rsv {
 	u64 values[BTRFS_QGROUP_RSV_LAST];
@@ -246,15 +337,6 @@
 void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info,
 			       u64 ref_root, u64 num_bytes,
 			       enum btrfs_qgroup_rsv_type type);
-static inline void btrfs_qgroup_free_delayed_ref(struct btrfs_fs_info *fs_info,
-						 u64 ref_root, u64 num_bytes)
-{
-	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
-		return;
-	trace_btrfs_qgroup_free_delayed_ref(fs_info, ref_root, num_bytes);
-	btrfs_qgroup_free_refroot(fs_info, ref_root, num_bytes,
-				  BTRFS_QGROUP_RSV_DATA);
-}
 
 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
@@ -319,4 +401,18 @@
 
 void btrfs_qgroup_check_reserved_leak(struct inode *inode);
 
+/* btrfs_qgroup_swapped_blocks related functions */
+void btrfs_qgroup_init_swapped_blocks(
+	struct btrfs_qgroup_swapped_blocks *swapped_blocks);
+
+void btrfs_qgroup_clean_swapped_blocks(struct btrfs_root *root);
+int btrfs_qgroup_add_swapped_blocks(struct btrfs_trans_handle *trans,
+		struct btrfs_root *subvol_root,
+		struct btrfs_block_group_cache *bg,
+		struct extent_buffer *subvol_parent, int subvol_slot,
+		struct extent_buffer *reloc_parent, int reloc_slot,
+		u64 last_snapshot);
+int btrfs_qgroup_trace_subtree_after_cow(struct btrfs_trans_handle *trans,
+		struct btrfs_root *root, struct extent_buffer *eb);
+
 #endif
diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index df41d70..57a2ac7 100644
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -35,6 +35,22 @@
 
 #define RBIO_CACHE_SIZE 1024
 
+#define BTRFS_STRIPE_HASH_TABLE_BITS				11
+
+/* Used by the raid56 code to lock stripes for read/modify/write */
+struct btrfs_stripe_hash {
+	struct list_head hash_list;
+	spinlock_t lock;
+};
+
+/* Used by the raid56 code to lock stripes for read/modify/write */
+struct btrfs_stripe_hash_table {
+	struct list_head stripe_cache;
+	spinlock_t cache_lock;
+	int cache_size;
+	struct btrfs_stripe_hash table[];
+};
+
 enum btrfs_rbio_ops {
 	BTRFS_RBIO_WRITE,
 	BTRFS_RBIO_READ_REBUILD,
@@ -1442,11 +1458,11 @@
 static void set_bio_pages_uptodate(struct bio *bio)
 {
 	struct bio_vec *bvec;
-	int i;
+	struct bvec_iter_all iter_all;
 
 	ASSERT(!bio_flagged(bio, BIO_CLONED));
 
-	bio_for_each_segment_all(bvec, bio, i)
+	bio_for_each_segment_all(bvec, bio, iter_all)
 		SetPageUptodate(bvec->bv_page);
 }
 
@@ -1980,7 +1996,7 @@
 		 * - In case of single failure, where rbio->failb == -1:
 		 *
 		 *   Cache this rbio iff the above read reconstruction is
-		 *   excuted without problems.
+		 *   executed without problems.
 		 */
 		if (err == BLK_STS_OK && rbio->failb < 0)
 			cache_rbio_pages(rbio);
@@ -2429,8 +2445,9 @@
 			bitmap_clear(rbio->dbitmap, pagenr, 1);
 		kunmap(p);
 
-		for (stripe = 0; stripe < rbio->real_stripes; stripe++)
+		for (stripe = 0; stripe < nr_data; stripe++)
 			kunmap(page_in_rbio(rbio, stripe, pagenr, 0));
+		kunmap(p_page);
 	}
 
 	__free_page(p_page);
diff --git a/fs/btrfs/raid56.h b/fs/btrfs/raid56.h
index f5d4c13..2503485 100644
--- a/fs/btrfs/raid56.h
+++ b/fs/btrfs/raid56.h
@@ -7,7 +7,7 @@
 #ifndef BTRFS_RAID56_H
 #define BTRFS_RAID56_H
 
-static inline int nr_parity_stripes(struct map_lookup *map)
+static inline int nr_parity_stripes(const struct map_lookup *map)
 {
 	if (map->type & BTRFS_BLOCK_GROUP_RAID5)
 		return 1;
@@ -17,7 +17,7 @@
 		return 0;
 }
 
-static inline int nr_data_stripes(struct map_lookup *map)
+static inline int nr_data_stripes(const struct map_lookup *map)
 {
 	return map->num_stripes - nr_parity_stripes(map);
 }
diff --git a/fs/btrfs/reada.c b/fs/btrfs/reada.c
index dec14b7..ee6f605 100644
--- a/fs/btrfs/reada.c
+++ b/fs/btrfs/reada.c
@@ -14,6 +14,7 @@
 #include "disk-io.h"
 #include "transaction.h"
 #include "dev-replace.h"
+#include "block-group.h"
 
 #undef DEBUG
 
@@ -376,26 +377,28 @@
 		goto error;
 	}
 
+	/* Insert extent in reada tree + all per-device trees, all or nothing */
+	down_read(&fs_info->dev_replace.rwsem);
 	ret = radix_tree_preload(GFP_KERNEL);
-	if (ret)
+	if (ret) {
+		up_read(&fs_info->dev_replace.rwsem);
 		goto error;
+	}
 
-	/* insert extent in reada_tree + all per-device trees, all or nothing */
-	btrfs_dev_replace_read_lock(&fs_info->dev_replace);
 	spin_lock(&fs_info->reada_lock);
 	ret = radix_tree_insert(&fs_info->reada_tree, index, re);
 	if (ret == -EEXIST) {
 		re_exist = radix_tree_lookup(&fs_info->reada_tree, index);
 		re_exist->refcnt++;
 		spin_unlock(&fs_info->reada_lock);
-		btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
 		radix_tree_preload_end();
+		up_read(&fs_info->dev_replace.rwsem);
 		goto error;
 	}
 	if (ret) {
 		spin_unlock(&fs_info->reada_lock);
-		btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
 		radix_tree_preload_end();
+		up_read(&fs_info->dev_replace.rwsem);
 		goto error;
 	}
 	radix_tree_preload_end();
@@ -437,13 +440,13 @@
 			}
 			radix_tree_delete(&fs_info->reada_tree, index);
 			spin_unlock(&fs_info->reada_lock);
-			btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
+			up_read(&fs_info->dev_replace.rwsem);
 			goto error;
 		}
 		have_zone = 1;
 	}
 	spin_unlock(&fs_info->reada_lock);
-	btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
+	up_read(&fs_info->dev_replace.rwsem);
 
 	if (!have_zone)
 		goto error;
@@ -636,6 +639,35 @@
 	return 1;
 }
 
+static int reada_tree_block_flagged(struct btrfs_fs_info *fs_info, u64 bytenr,
+				    int mirror_num, struct extent_buffer **eb)
+{
+	struct extent_buffer *buf = NULL;
+	int ret;
+
+	buf = btrfs_find_create_tree_block(fs_info, bytenr);
+	if (IS_ERR(buf))
+		return 0;
+
+	set_bit(EXTENT_BUFFER_READAHEAD, &buf->bflags);
+
+	ret = read_extent_buffer_pages(buf, WAIT_PAGE_LOCK, mirror_num);
+	if (ret) {
+		free_extent_buffer_stale(buf);
+		return ret;
+	}
+
+	if (test_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags)) {
+		free_extent_buffer_stale(buf);
+		return -EIO;
+	} else if (extent_buffer_uptodate(buf)) {
+		*eb = buf;
+	} else {
+		free_extent_buffer(buf);
+	}
+	return 0;
+}
+
 static int reada_start_machine_dev(struct btrfs_device *dev)
 {
 	struct btrfs_fs_info *fs_info = dev->fs_info;
@@ -745,6 +777,7 @@
 	u64 total = 0;
 	int i;
 
+again:
 	do {
 		enqueued = 0;
 		mutex_lock(&fs_devices->device_list_mutex);
@@ -756,6 +789,10 @@
 		mutex_unlock(&fs_devices->device_list_mutex);
 		total += enqueued;
 	} while (enqueued && total < 10000);
+	if (fs_devices->seed) {
+		fs_devices = fs_devices->seed;
+		goto again;
+	}
 
 	if (enqueued == 0)
 		return;
diff --git a/fs/btrfs/ref-verify.c b/fs/btrfs/ref-verify.c
index e5b9e59..b57f361 100644
--- a/fs/btrfs/ref-verify.c
+++ b/fs/btrfs/ref-verify.c
@@ -43,7 +43,7 @@
  * back to the delayed ref action.  We hold the ref we are changing in the
  * action so we can account for the history properly, and we record the root we
  * were called with since it could be different from ref_root.  We also store
- * stack traces because thats how I roll.
+ * stack traces because that's how I roll.
  */
 struct ref_action {
 	int action;
@@ -56,7 +56,7 @@
 
 /*
  * One of these for every block we reference, it holds the roots and references
- * to it as well as all of the ref actions that have occured to it.  We never
+ * to it as well as all of the ref actions that have occurred to it.  We never
  * free it until we unmount the file system in order to make sure re-allocations
  * are happening properly.
  */
@@ -205,28 +205,17 @@
 #ifdef CONFIG_STACKTRACE
 static void __save_stack_trace(struct ref_action *ra)
 {
-	struct stack_trace stack_trace;
-
-	stack_trace.max_entries = MAX_TRACE;
-	stack_trace.nr_entries = 0;
-	stack_trace.entries = ra->trace;
-	stack_trace.skip = 2;
-	save_stack_trace(&stack_trace);
-	ra->trace_len = stack_trace.nr_entries;
+	ra->trace_len = stack_trace_save(ra->trace, MAX_TRACE, 2);
 }
 
 static void __print_stack_trace(struct btrfs_fs_info *fs_info,
 				struct ref_action *ra)
 {
-	struct stack_trace trace;
-
 	if (ra->trace_len == 0) {
 		btrfs_err(fs_info, "  ref-verify: no stacktrace");
 		return;
 	}
-	trace.nr_entries = ra->trace_len;
-	trace.entries = ra->trace;
-	print_stack_trace(&trace, 2);
+	stack_trace_print(ra->trace, ra->trace_len, 2);
 }
 #else
 static void inline __save_stack_trace(struct ref_action *ra)
@@ -511,7 +500,7 @@
 	struct btrfs_extent_data_ref *dref;
 	struct btrfs_shared_data_ref *sref;
 	u32 count;
-	int i = 0, tree_block_level = 0, ret;
+	int i = 0, tree_block_level = 0, ret = 0;
 	struct btrfs_key key;
 	int nritems = btrfs_header_nritems(leaf);
 
@@ -520,6 +509,7 @@
 		switch (key.type) {
 		case BTRFS_EXTENT_ITEM_KEY:
 			*num_bytes = key.offset;
+			/* fall through */
 		case BTRFS_METADATA_ITEM_KEY:
 			*bytenr = key.objectid;
 			ret = process_extent_item(fs_info, path, &key, i,
@@ -583,7 +573,7 @@
 				return -EIO;
 			}
 			btrfs_tree_read_lock(eb);
-			btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
+			btrfs_set_lock_blocking_read(eb);
 			path->nodes[level-1] = eb;
 			path->slots[level-1] = 0;
 			path->locks[level-1] = BTRFS_READ_LOCK_BLOCKING;
@@ -670,36 +660,43 @@
 
 /*
  * btrfs_ref_tree_mod: called when we modify a ref for a bytenr
- * @root: the root we are making this modification from.
- * @bytenr: the bytenr we are modifying.
- * @num_bytes: number of bytes.
- * @parent: the parent bytenr.
- * @ref_root: the original root owner of the bytenr.
- * @owner: level in the case of metadata, inode in the case of data.
- * @offset: 0 for metadata, file offset for data.
- * @action: the action that we are doing, this is the same as the delayed ref
- *	action.
  *
  * This will add an action item to the given bytenr and do sanity checks to make
  * sure we haven't messed something up.  If we are making a new allocation and
  * this block entry has history we will delete all previous actions as long as
  * our sanity checks pass as they are no longer needed.
  */
-int btrfs_ref_tree_mod(struct btrfs_root *root, u64 bytenr, u64 num_bytes,
-		       u64 parent, u64 ref_root, u64 owner, u64 offset,
-		       int action)
+int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
+		       struct btrfs_ref *generic_ref)
 {
-	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct ref_entry *ref = NULL, *exist;
 	struct ref_action *ra = NULL;
 	struct block_entry *be = NULL;
 	struct root_entry *re = NULL;
+	int action = generic_ref->action;
 	int ret = 0;
-	bool metadata = owner < BTRFS_FIRST_FREE_OBJECTID;
+	bool metadata;
+	u64 bytenr = generic_ref->bytenr;
+	u64 num_bytes = generic_ref->len;
+	u64 parent = generic_ref->parent;
+	u64 ref_root;
+	u64 owner;
+	u64 offset;
 
-	if (!btrfs_test_opt(root->fs_info, REF_VERIFY))
+	if (!btrfs_test_opt(fs_info, REF_VERIFY))
 		return 0;
 
+	if (generic_ref->type == BTRFS_REF_METADATA) {
+		ref_root = generic_ref->tree_ref.root;
+		owner = generic_ref->tree_ref.level;
+		offset = 0;
+	} else {
+		ref_root = generic_ref->data_ref.ref_root;
+		owner = generic_ref->data_ref.ino;
+		offset = generic_ref->data_ref.offset;
+	}
+	metadata = owner < BTRFS_FIRST_FREE_OBJECTID;
+
 	ref = kzalloc(sizeof(struct ref_entry), GFP_NOFS);
 	ra = kmalloc(sizeof(struct ref_action), GFP_NOFS);
 	if (!ra || !ref) {
@@ -732,7 +729,7 @@
 
 	INIT_LIST_HEAD(&ra->list);
 	ra->action = action;
-	ra->root = root->objectid;
+	ra->root = generic_ref->real_root;
 
 	/*
 	 * This is an allocation, preallocate the block_entry in case we haven't
@@ -745,7 +742,7 @@
 		 * is and the new root objectid, so let's not treat the passed
 		 * in root as if it really has a ref for this bytenr.
 		 */
-		be = add_block_entry(root->fs_info, bytenr, num_bytes, ref_root);
+		be = add_block_entry(fs_info, bytenr, num_bytes, ref_root);
 		if (IS_ERR(be)) {
 			kfree(ra);
 			ret = PTR_ERR(be);
@@ -787,13 +784,13 @@
 			 * one we want to lookup below when we modify the
 			 * re->num_refs.
 			 */
-			ref_root = root->objectid;
-			re->root_objectid = root->objectid;
+			ref_root = generic_ref->real_root;
+			re->root_objectid = generic_ref->real_root;
 			re->num_refs = 0;
 		}
 
-		spin_lock(&root->fs_info->ref_verify_lock);
-		be = lookup_block_entry(&root->fs_info->block_tree, bytenr);
+		spin_lock(&fs_info->ref_verify_lock);
+		be = lookup_block_entry(&fs_info->block_tree, bytenr);
 		if (!be) {
 			btrfs_err(fs_info,
 "trying to do action %d to bytenr %llu num_bytes %llu but there is no existing entry!",
@@ -859,10 +856,10 @@
 			 * This shouldn't happen because we will add our re
 			 * above when we lookup the be with !parent, but just in
 			 * case catch this case so we don't panic because I
-			 * didn't thik of some other corner case.
+			 * didn't think of some other corner case.
 			 */
 			btrfs_err(fs_info, "failed to find root %llu for %llu",
-				  root->objectid, be->bytenr);
+				  generic_ref->real_root, be->bytenr);
 			dump_block_entry(fs_info, be);
 			dump_ref_action(fs_info, ra);
 			kfree(ra);
@@ -881,7 +878,7 @@
 	list_add_tail(&ra->list, &be->actions);
 	ret = 0;
 out_unlock:
-	spin_unlock(&root->fs_info->ref_verify_lock);
+	spin_unlock(&fs_info->ref_verify_lock);
 out:
 	if (ret)
 		btrfs_clear_opt(fs_info->mount_opt, REF_VERIFY);
@@ -987,7 +984,7 @@
 		return -ENOMEM;
 
 	eb = btrfs_read_lock_root_node(fs_info->extent_root);
-	btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
+	btrfs_set_lock_blocking_read(eb);
 	level = btrfs_header_level(eb);
 	path->nodes[level] = eb;
 	path->slots[level] = 0;
diff --git a/fs/btrfs/ref-verify.h b/fs/btrfs/ref-verify.h
index b7d2a4e..855de37 100644
--- a/fs/btrfs/ref-verify.h
+++ b/fs/btrfs/ref-verify.h
@@ -9,9 +9,8 @@
 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
 int btrfs_build_ref_tree(struct btrfs_fs_info *fs_info);
 void btrfs_free_ref_cache(struct btrfs_fs_info *fs_info);
-int btrfs_ref_tree_mod(struct btrfs_root *root, u64 bytenr, u64 num_bytes,
-		       u64 parent, u64 ref_root, u64 owner, u64 offset,
-		       int action);
+int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
+		       struct btrfs_ref *generic_ref);
 void btrfs_free_ref_tree_range(struct btrfs_fs_info *fs_info, u64 start,
 			       u64 len);
 
@@ -30,9 +29,8 @@
 {
 }
 
-static inline int btrfs_ref_tree_mod(struct btrfs_root *root, u64 bytenr,
-				     u64 num_bytes, u64 parent, u64 ref_root,
-				     u64 owner, u64 offset, int action)
+static inline int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
+		       struct btrfs_ref *generic_ref)
 {
 	return 0;
 }
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 0526b6c..5cd42b6 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -20,6 +20,8 @@
 #include "inode-map.h"
 #include "qgroup.h"
 #include "print-tree.h"
+#include "delalloc-space.h"
+#include "block-group.h"
 
 /*
  * backref_node, mapping_node and tree_block start with this
@@ -162,6 +164,8 @@
 	struct mapping_tree reloc_root_tree;
 	/* list of reloc trees */
 	struct list_head reloc_roots;
+	/* list of subvolume trees that get relocated */
+	struct list_head dirty_subvol_roots;
 	/* size of metadata reservation for merging reloc trees */
 	u64 merging_rsv_size;
 	/* size of relocated tree nodes */
@@ -648,8 +652,8 @@
 					int level, u64 bytenr)
 {
 	struct backref_cache *cache = &rc->backref_cache;
-	struct btrfs_path *path1;
-	struct btrfs_path *path2;
+	struct btrfs_path *path1; /* For searching extent root */
+	struct btrfs_path *path2; /* For searching parent of TREE_BLOCK_REF */
 	struct extent_buffer *eb;
 	struct btrfs_root *root;
 	struct backref_node *cur;
@@ -662,7 +666,7 @@
 	struct btrfs_key key;
 	unsigned long end;
 	unsigned long ptr;
-	LIST_HEAD(list);
+	LIST_HEAD(list); /* Pending edge list, upper node needs to be checked */
 	LIST_HEAD(useless);
 	int cowonly;
 	int ret;
@@ -778,6 +782,10 @@
 				key.type != BTRFS_SHARED_BLOCK_REF_KEY);
 		}
 
+		/*
+		 * Parent node found and matches current inline ref, no need to
+		 * rebuild this node for this inline ref.
+		 */
 		if (exist &&
 		    ((key.type == BTRFS_TREE_BLOCK_REF_KEY &&
 		      exist->owner == key.offset) ||
@@ -787,11 +795,12 @@
 			goto next;
 		}
 
+		/* SHARED_BLOCK_REF means key.offset is the parent bytenr */
 		if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) {
 			if (key.objectid == key.offset) {
 				/*
-				 * only root blocks of reloc trees use
-				 * backref of this type.
+				 * Only root blocks of reloc trees use backref
+				 * pointing to itself.
 				 */
 				root = find_reloc_root(rc, cur->bytenr);
 				ASSERT(root);
@@ -840,7 +849,11 @@
 			goto next;
 		}
 
-		/* key.type == BTRFS_TREE_BLOCK_REF_KEY */
+		/*
+		 * key.type == BTRFS_TREE_BLOCK_REF_KEY, inline ref offset
+		 * means the root objectid. We need to search the tree to get
+		 * its parent bytenr.
+		 */
 		root = read_fs_root(rc->extent_root->fs_info, key.offset);
 		if (IS_ERR(root)) {
 			err = PTR_ERR(root);
@@ -863,10 +876,7 @@
 
 		level = cur->level + 1;
 
-		/*
-		 * searching the tree to find upper level blocks
-		 * reference the block.
-		 */
+		/* Search the tree to find parent blocks referring the block. */
 		path2->search_commit_root = 1;
 		path2->skip_locking = 1;
 		path2->lowest_level = level;
@@ -884,7 +894,8 @@
 		    cur->bytenr) {
 			btrfs_err(root->fs_info,
 	"couldn't find block (%llu) (level %d) in tree (%llu) with key (%llu %u %llu)",
-				  cur->bytenr, level - 1, root->objectid,
+				  cur->bytenr, level - 1,
+				  root->root_key.objectid,
 				  node_key->objectid, node_key->type,
 				  node_key->offset);
 			err = -ENOENT;
@@ -892,6 +903,8 @@
 		}
 		lower = cur;
 		need_check = true;
+
+		/* Add all nodes and edges in the path */
 		for (; level < BTRFS_MAX_LEVEL; level++) {
 			if (!path2->nodes[level]) {
 				ASSERT(btrfs_root_bytenr(&root->root_item) ==
@@ -1422,6 +1435,13 @@
 	int clear_rsv = 0;
 	int ret;
 
+	/*
+	 * The subvolume has reloc tree but the swap is finished, no need to
+	 * create/update the dead reloc tree
+	 */
+	if (test_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state))
+		return 0;
+
 	if (root->reloc_root) {
 		reloc_root = root->reloc_root;
 		reloc_root->last_trans = trans->transid;
@@ -1458,15 +1478,17 @@
 	struct btrfs_root_item *root_item;
 	int ret;
 
-	if (!root->reloc_root)
+	if (test_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state) ||
+	    !root->reloc_root)
 		goto out;
 
 	reloc_root = root->reloc_root;
 	root_item = &reloc_root->root_item;
 
+	/* root->reloc_root will stay until current relocation finished */
 	if (fs_info->reloc_ctl->merge_reloc_tree &&
 	    btrfs_root_refs(root_item) == 0) {
-		root->reloc_root = NULL;
+		set_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state);
 		__del_reloc_root(reloc_root);
 	}
 
@@ -1630,6 +1652,8 @@
 
 	nritems = btrfs_header_nritems(leaf);
 	for (i = 0; i < nritems; i++) {
+		struct btrfs_ref ref = { 0 };
+
 		cond_resched();
 		btrfs_item_key_to_cpu(leaf, &key, i);
 		if (key.type != BTRFS_EXTENT_DATA_KEY)
@@ -1690,18 +1714,23 @@
 		dirty = 1;
 
 		key.offset -= btrfs_file_extent_offset(leaf, fi);
-		ret = btrfs_inc_extent_ref(trans, root, new_bytenr,
-					   num_bytes, parent,
-					   btrfs_header_owner(leaf),
-					   key.objectid, key.offset);
+		btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, new_bytenr,
+				       num_bytes, parent);
+		ref.real_root = root->root_key.objectid;
+		btrfs_init_data_ref(&ref, btrfs_header_owner(leaf),
+				    key.objectid, key.offset);
+		ret = btrfs_inc_extent_ref(trans, &ref);
 		if (ret) {
 			btrfs_abort_transaction(trans, ret);
 			break;
 		}
 
-		ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
-					parent, btrfs_header_owner(leaf),
-					key.objectid, key.offset);
+		btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, bytenr,
+				       num_bytes, parent);
+		ref.real_root = root->root_key.objectid;
+		btrfs_init_data_ref(&ref, btrfs_header_owner(leaf),
+				    key.objectid, key.offset);
+		ret = btrfs_free_extent(trans, &ref);
 		if (ret) {
 			btrfs_abort_transaction(trans, ret);
 			break;
@@ -1735,7 +1764,7 @@
  * errors, a negative error number is returned.
  */
 static noinline_for_stack
-int replace_path(struct btrfs_trans_handle *trans,
+int replace_path(struct btrfs_trans_handle *trans, struct reloc_control *rc,
 		 struct btrfs_root *dest, struct btrfs_root *src,
 		 struct btrfs_path *path, struct btrfs_key *next_key,
 		 int lowest_level, int max_level)
@@ -1743,6 +1772,7 @@
 	struct btrfs_fs_info *fs_info = dest->fs_info;
 	struct extent_buffer *eb;
 	struct extent_buffer *parent;
+	struct btrfs_ref ref = { 0 };
 	struct btrfs_key key;
 	u64 old_bytenr;
 	u64 new_bytenr;
@@ -1764,7 +1794,7 @@
 	btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot);
 
 	eb = btrfs_lock_root_node(dest);
-	btrfs_set_lock_blocking(eb);
+	btrfs_set_lock_blocking_write(eb);
 	level = btrfs_header_level(eb);
 
 	if (level < lowest_level) {
@@ -1777,7 +1807,7 @@
 		ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb);
 		BUG_ON(ret);
 	}
-	btrfs_set_lock_blocking(eb);
+	btrfs_set_lock_blocking_write(eb);
 
 	if (next_key) {
 		next_key->objectid = (u64)-1;
@@ -1793,6 +1823,8 @@
 		BUG_ON(level < lowest_level);
 
 		ret = btrfs_bin_search(parent, &key, level, &slot);
+		if (ret < 0)
+			break;
 		if (ret && slot > 0)
 			slot--;
 
@@ -1843,7 +1875,7 @@
 						      slot, &eb);
 				BUG_ON(ret);
 			}
-			btrfs_set_lock_blocking(eb);
+			btrfs_set_lock_blocking_write(eb);
 
 			btrfs_tree_unlock(parent);
 			free_extent_buffer(parent);
@@ -1876,20 +1908,18 @@
 		 *    If not traced, we will leak data numbers
 		 * 2) Fs subtree
 		 *    If not traced, we will double count old data
-		 *    and tree block numbers, if current trans doesn't free
-		 *    data reloc tree inode.
+		 *
+		 * We don't scan the subtree right now, but only record
+		 * the swapped tree blocks.
+		 * The real subtree rescan is delayed until we have new
+		 * CoW on the subtree root node before transaction commit.
 		 */
-		ret = btrfs_qgroup_trace_subtree(trans, parent,
-				btrfs_header_generation(parent),
-				btrfs_header_level(parent));
+		ret = btrfs_qgroup_add_swapped_blocks(trans, dest,
+				rc->block_group, parent, slot,
+				path->nodes[level], path->slots[level],
+				last_snapshot);
 		if (ret < 0)
 			break;
-		ret = btrfs_qgroup_trace_subtree(trans, path->nodes[level],
-				btrfs_header_generation(path->nodes[level]),
-				btrfs_header_level(path->nodes[level]));
-		if (ret < 0)
-			break;
-
 		/*
 		 * swap blocks in fs tree and reloc tree.
 		 */
@@ -1903,23 +1933,31 @@
 					      path->slots[level], old_ptr_gen);
 		btrfs_mark_buffer_dirty(path->nodes[level]);
 
-		ret = btrfs_inc_extent_ref(trans, src, old_bytenr,
-					blocksize, path->nodes[level]->start,
-					src->root_key.objectid, level - 1, 0);
+		btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, old_bytenr,
+				       blocksize, path->nodes[level]->start);
+		ref.skip_qgroup = true;
+		btrfs_init_tree_ref(&ref, level - 1, src->root_key.objectid);
+		ret = btrfs_inc_extent_ref(trans, &ref);
 		BUG_ON(ret);
-		ret = btrfs_inc_extent_ref(trans, dest, new_bytenr,
-					blocksize, 0, dest->root_key.objectid,
-					level - 1, 0);
+		btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, new_bytenr,
+				       blocksize, 0);
+		ref.skip_qgroup = true;
+		btrfs_init_tree_ref(&ref, level - 1, dest->root_key.objectid);
+		ret = btrfs_inc_extent_ref(trans, &ref);
 		BUG_ON(ret);
 
-		ret = btrfs_free_extent(trans, src, new_bytenr, blocksize,
-					path->nodes[level]->start,
-					src->root_key.objectid, level - 1, 0);
+		btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, new_bytenr,
+				       blocksize, path->nodes[level]->start);
+		btrfs_init_tree_ref(&ref, level - 1, src->root_key.objectid);
+		ref.skip_qgroup = true;
+		ret = btrfs_free_extent(trans, &ref);
 		BUG_ON(ret);
 
-		ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize,
-					0, dest->root_key.objectid, level - 1,
-					0);
+		btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, old_bytenr,
+				       blocksize, 0);
+		btrfs_init_tree_ref(&ref, level - 1, dest->root_key.objectid);
+		ref.skip_qgroup = true;
+		ret = btrfs_free_extent(trans, &ref);
 		BUG_ON(ret);
 
 		btrfs_unlock_up_safe(path, 0);
@@ -2117,6 +2155,66 @@
 }
 
 /*
+ * Insert current subvolume into reloc_control::dirty_subvol_roots
+ */
+static void insert_dirty_subvol(struct btrfs_trans_handle *trans,
+				struct reloc_control *rc,
+				struct btrfs_root *root)
+{
+	struct btrfs_root *reloc_root = root->reloc_root;
+	struct btrfs_root_item *reloc_root_item;
+
+	/* @root must be a subvolume tree root with a valid reloc tree */
+	ASSERT(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
+	ASSERT(reloc_root);
+
+	reloc_root_item = &reloc_root->root_item;
+	memset(&reloc_root_item->drop_progress, 0,
+		sizeof(reloc_root_item->drop_progress));
+	reloc_root_item->drop_level = 0;
+	btrfs_set_root_refs(reloc_root_item, 0);
+	btrfs_update_reloc_root(trans, root);
+
+	if (list_empty(&root->reloc_dirty_list)) {
+		btrfs_grab_fs_root(root);
+		list_add_tail(&root->reloc_dirty_list, &rc->dirty_subvol_roots);
+	}
+}
+
+static int clean_dirty_subvols(struct reloc_control *rc)
+{
+	struct btrfs_root *root;
+	struct btrfs_root *next;
+	int ret = 0;
+	int ret2;
+
+	list_for_each_entry_safe(root, next, &rc->dirty_subvol_roots,
+				 reloc_dirty_list) {
+		if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
+			/* Merged subvolume, cleanup its reloc root */
+			struct btrfs_root *reloc_root = root->reloc_root;
+
+			list_del_init(&root->reloc_dirty_list);
+			root->reloc_root = NULL;
+			if (reloc_root) {
+
+				ret2 = btrfs_drop_snapshot(reloc_root, NULL, 0, 1);
+				if (ret2 < 0 && !ret)
+					ret = ret2;
+			}
+			clear_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state);
+			btrfs_put_fs_root(root);
+		} else {
+			/* Orphan reloc tree, just clean it up */
+			ret2 = btrfs_drop_snapshot(root, NULL, 0, 1);
+			if (ret2 < 0 && !ret)
+				ret = ret2;
+		}
+	}
+	return ret;
+}
+
+/*
  * merge the relocated tree blocks in reloc tree with corresponding
  * fs tree.
  */
@@ -2124,7 +2222,6 @@
 					       struct btrfs_root *root)
 {
 	struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
-	LIST_HEAD(inode_list);
 	struct btrfs_key key;
 	struct btrfs_key next_key;
 	struct btrfs_trans_handle *trans = NULL;
@@ -2205,7 +2302,7 @@
 		    btrfs_comp_cpu_keys(&next_key, &key) >= 0) {
 			ret = 0;
 		} else {
-			ret = replace_path(trans, root, reloc_root, path,
+			ret = replace_path(trans, rc, root, reloc_root, path,
 					   &next_key, level, max_level);
 		}
 		if (ret < 0) {
@@ -2255,13 +2352,8 @@
 out:
 	btrfs_free_path(path);
 
-	if (err == 0) {
-		memset(&root_item->drop_progress, 0,
-		       sizeof(root_item->drop_progress));
-		root_item->drop_level = 0;
-		btrfs_set_root_refs(root_item, 0);
-		btrfs_update_reloc_root(trans, root);
-	}
+	if (err == 0)
+		insert_dirty_subvol(trans, rc, root);
 
 	if (trans)
 		btrfs_end_transaction_throttle(trans);
@@ -2405,14 +2497,9 @@
 			}
 		} else {
 			list_del_init(&reloc_root->root_list);
-		}
-
-		ret = btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0, 1);
-		if (ret < 0) {
-			if (list_empty(&reloc_root->root_list))
-				list_add_tail(&reloc_root->root_list,
-					      &reloc_roots);
-			goto out;
+			/* Don't forget to queue this reloc root for cleanup */
+			list_add_tail(&reloc_root->reloc_dirty_list,
+				      &rc->dirty_subvol_roots);
 		}
 	}
 
@@ -2627,7 +2714,7 @@
 		 * only one thread can access block_rsv at this point,
 		 * so we don't need hold lock to protect block_rsv.
 		 * we expand more reservation size here to allow enough
-		 * space for relocation and we will return eailer in
+		 * space for relocation and we will return earlier in
 		 * enospc case.
 		 */
 		rc->block_rsv->size = tmp + fs_info->nodesize *
@@ -2670,6 +2757,7 @@
 	rc->backref_cache.path[node->level] = node;
 	list_for_each_entry(edge, &node->upper, list[LOWER]) {
 		struct btrfs_key first_key;
+		struct btrfs_ref ref = { 0 };
 
 		cond_resched();
 
@@ -2681,6 +2769,10 @@
 			if (!lowest) {
 				ret = btrfs_bin_search(upper->eb, key,
 						       upper->level, &slot);
+				if (ret < 0) {
+					err = ret;
+					goto next;
+				}
 				BUG_ON(ret);
 				bytenr = btrfs_node_blockptr(upper->eb, slot);
 				if (node->eb->start == bytenr)
@@ -2716,6 +2808,10 @@
 		} else {
 			ret = btrfs_bin_search(upper->eb, key, upper->level,
 					       &slot);
+			if (ret < 0) {
+				err = ret;
+				goto next;
+			}
 			BUG_ON(ret);
 		}
 
@@ -2748,7 +2844,7 @@
 			goto next;
 		}
 		btrfs_tree_lock(eb);
-		btrfs_set_lock_blocking(eb);
+		btrfs_set_lock_blocking_write(eb);
 
 		if (!node->eb) {
 			ret = btrfs_cow_block(trans, root, eb, upper->eb,
@@ -2767,11 +2863,13 @@
 						      trans->transid);
 			btrfs_mark_buffer_dirty(upper->eb);
 
-			ret = btrfs_inc_extent_ref(trans, root,
-						node->eb->start, blocksize,
-						upper->eb->start,
-						btrfs_header_owner(upper->eb),
-						node->level, 0);
+			btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF,
+					       node->eb->start, blocksize,
+					       upper->eb->start);
+			ref.real_root = root->root_key.objectid;
+			btrfs_init_tree_ref(&ref, node->level,
+					    btrfs_header_owner(upper->eb));
+			ret = btrfs_inc_extent_ref(trans, &ref);
 			BUG_ON(ret);
 
 			ret = btrfs_drop_subtree(trans, root, eb, upper->eb);
@@ -2911,7 +3009,6 @@
 		free_extent_buffer(eb);
 		return -EIO;
 	}
-	WARN_ON(btrfs_header_level(eb) != block->level);
 	if (block->level == 0)
 		btrfs_item_key_to_cpu(eb, &block->key, 0);
 	else
@@ -2987,7 +3084,7 @@
 	struct backref_node *node;
 	struct btrfs_path *path;
 	struct tree_block *block;
-	struct rb_node *rb_node;
+	struct tree_block *next;
 	int ret;
 	int err = 0;
 
@@ -2997,29 +3094,23 @@
 		goto out_free_blocks;
 	}
 
-	rb_node = rb_first(blocks);
-	while (rb_node) {
-		block = rb_entry(rb_node, struct tree_block, rb_node);
+	/* Kick in readahead for tree blocks with missing keys */
+	rbtree_postorder_for_each_entry_safe(block, next, blocks, rb_node) {
 		if (!block->key_ready)
 			readahead_tree_block(fs_info, block->bytenr);
-		rb_node = rb_next(rb_node);
 	}
 
-	rb_node = rb_first(blocks);
-	while (rb_node) {
-		block = rb_entry(rb_node, struct tree_block, rb_node);
+	/* Get first keys */
+	rbtree_postorder_for_each_entry_safe(block, next, blocks, rb_node) {
 		if (!block->key_ready) {
 			err = get_tree_block_key(fs_info, block);
 			if (err)
 				goto out_free_path;
 		}
-		rb_node = rb_next(rb_node);
 	}
 
-	rb_node = rb_first(blocks);
-	while (rb_node) {
-		block = rb_entry(rb_node, struct tree_block, rb_node);
-
+	/* Do tree relocation */
+	rbtree_postorder_for_each_entry_safe(block, next, blocks, rb_node) {
 		node = build_backref_tree(rc, &block->key,
 					  block->level, block->bytenr);
 		if (IS_ERR(node)) {
@@ -3030,11 +3121,10 @@
 		ret = relocate_tree_block(trans, rc, node, &block->key,
 					  path);
 		if (ret < 0) {
-			if (ret != -EAGAIN || rb_node == rb_first(blocks))
+			if (ret != -EAGAIN || &block->rb_node == rb_first(blocks))
 				err = ret;
 			goto out;
 		}
-		rb_node = rb_next(rb_node);
 	}
 out:
 	err = finish_pending_nodes(trans, rc, path, err);
@@ -3187,6 +3277,8 @@
 			if (!page) {
 				btrfs_delalloc_release_metadata(BTRFS_I(inode),
 							PAGE_SIZE, true);
+				btrfs_delalloc_release_extents(BTRFS_I(inode),
+							PAGE_SIZE);
 				ret = -ENOMEM;
 				goto out;
 			}
@@ -3207,7 +3299,7 @@
 				btrfs_delalloc_release_metadata(BTRFS_I(inode),
 							PAGE_SIZE, true);
 				btrfs_delalloc_release_extents(BTRFS_I(inode),
-							       PAGE_SIZE, true);
+							       PAGE_SIZE);
 				ret = -EIO;
 				goto out;
 			}
@@ -3229,14 +3321,14 @@
 		}
 
 		ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 0,
-						NULL, 0);
+						NULL);
 		if (ret) {
 			unlock_page(page);
 			put_page(page);
 			btrfs_delalloc_release_metadata(BTRFS_I(inode),
 							 PAGE_SIZE, true);
 			btrfs_delalloc_release_extents(BTRFS_I(inode),
-			                               PAGE_SIZE, true);
+			                               PAGE_SIZE);
 
 			clear_extent_bits(&BTRFS_I(inode)->io_tree,
 					  page_start, page_end,
@@ -3252,8 +3344,7 @@
 		put_page(page);
 
 		index++;
-		btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE,
-					       false);
+		btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
 		balance_dirty_pages_ratelimited(inode->i_mapping);
 		btrfs_throttle(fs_info);
 	}
@@ -4083,6 +4174,9 @@
 		goto out_free;
 	}
 	btrfs_commit_transaction(trans);
+	ret = clean_dirty_subvols(rc);
+	if (ret < 0 && !err)
+		err = ret;
 out_free:
 	btrfs_free_block_rsv(fs_info, rc->block_rsv);
 	btrfs_free_path(path);
@@ -4168,7 +4262,7 @@
 	return inode;
 }
 
-static struct reloc_control *alloc_reloc_control(void)
+static struct reloc_control *alloc_reloc_control(struct btrfs_fs_info *fs_info)
 {
 	struct reloc_control *rc;
 
@@ -4177,9 +4271,11 @@
 		return NULL;
 
 	INIT_LIST_HEAD(&rc->reloc_roots);
+	INIT_LIST_HEAD(&rc->dirty_subvol_roots);
 	backref_cache_init(&rc->backref_cache);
 	mapping_tree_init(&rc->reloc_root_tree);
-	extent_io_tree_init(&rc->processed_blocks, NULL);
+	extent_io_tree_init(fs_info, &rc->processed_blocks,
+			    IO_TREE_RELOC_BLOCKS, NULL);
 	return rc;
 }
 
@@ -4189,37 +4285,13 @@
 static void describe_relocation(struct btrfs_fs_info *fs_info,
 				struct btrfs_block_group_cache *block_group)
 {
-	char buf[128];		/* prefixed by a '|' that'll be dropped */
-	u64 flags = block_group->flags;
+	char buf[128] = {'\0'};
 
-	/* Shouldn't happen */
-	if (!flags) {
-		strcpy(buf, "|NONE");
-	} else {
-		char *bp = buf;
-
-#define DESCRIBE_FLAG(f, d) \
-		if (flags & BTRFS_BLOCK_GROUP_##f) { \
-			bp += snprintf(bp, buf - bp + sizeof(buf), "|%s", d); \
-			flags &= ~BTRFS_BLOCK_GROUP_##f; \
-		}
-		DESCRIBE_FLAG(DATA,     "data");
-		DESCRIBE_FLAG(SYSTEM,   "system");
-		DESCRIBE_FLAG(METADATA, "metadata");
-		DESCRIBE_FLAG(RAID0,    "raid0");
-		DESCRIBE_FLAG(RAID1,    "raid1");
-		DESCRIBE_FLAG(DUP,      "dup");
-		DESCRIBE_FLAG(RAID10,   "raid10");
-		DESCRIBE_FLAG(RAID5,    "raid5");
-		DESCRIBE_FLAG(RAID6,    "raid6");
-		if (flags)
-			snprintf(bp, buf - bp + sizeof(buf), "|0x%llx", flags);
-#undef DESCRIBE_FLAG
-	}
+	btrfs_describe_block_groups(block_group->flags, buf, sizeof(buf));
 
 	btrfs_info(fs_info,
 		   "relocating block group %llu flags %s",
-		   block_group->key.objectid, buf + 1);
+		   block_group->key.objectid, buf);
 }
 
 /*
@@ -4227,6 +4299,7 @@
  */
 int btrfs_relocate_block_group(struct btrfs_fs_info *fs_info, u64 group_start)
 {
+	struct btrfs_block_group_cache *bg;
 	struct btrfs_root *extent_root = fs_info->extent_root;
 	struct reloc_control *rc;
 	struct inode *inode;
@@ -4235,14 +4308,23 @@
 	int rw = 0;
 	int err = 0;
 
-	rc = alloc_reloc_control();
-	if (!rc)
+	bg = btrfs_lookup_block_group(fs_info, group_start);
+	if (!bg)
+		return -ENOENT;
+
+	if (btrfs_pinned_by_swapfile(fs_info, bg)) {
+		btrfs_put_block_group(bg);
+		return -ETXTBSY;
+	}
+
+	rc = alloc_reloc_control(fs_info);
+	if (!rc) {
+		btrfs_put_block_group(bg);
 		return -ENOMEM;
+	}
 
 	rc->extent_root = extent_root;
-
-	rc->block_group = btrfs_lookup_block_group(fs_info, group_start);
-	BUG_ON(!rc->block_group);
+	rc->block_group = bg;
 
 	ret = btrfs_inc_block_group_ro(rc->block_group);
 	if (ret) {
@@ -4257,7 +4339,7 @@
 		goto out;
 	}
 
-	inode = lookup_free_space_inode(fs_info, rc->block_group, path);
+	inode = lookup_free_space_inode(rc->block_group, path);
 	btrfs_free_path(path);
 
 	if (!IS_ERR(inode))
@@ -4289,27 +4371,36 @@
 		mutex_lock(&fs_info->cleaner_mutex);
 		ret = relocate_block_group(rc);
 		mutex_unlock(&fs_info->cleaner_mutex);
-		if (ret < 0) {
+		if (ret < 0)
 			err = ret;
-			goto out;
+
+		/*
+		 * We may have gotten ENOSPC after we already dirtied some
+		 * extents.  If writeout happens while we're relocating a
+		 * different block group we could end up hitting the
+		 * BUG_ON(rc->stage == UPDATE_DATA_PTRS) in
+		 * btrfs_reloc_cow_block.  Make sure we write everything out
+		 * properly so we don't trip over this problem, and then break
+		 * out of the loop if we hit an error.
+		 */
+		if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) {
+			ret = btrfs_wait_ordered_range(rc->data_inode, 0,
+						       (u64)-1);
+			if (ret)
+				err = ret;
+			invalidate_mapping_pages(rc->data_inode->i_mapping,
+						 0, -1);
+			rc->stage = UPDATE_DATA_PTRS;
 		}
 
+		if (err < 0)
+			goto out;
+
 		if (rc->extents_found == 0)
 			break;
 
 		btrfs_info(fs_info, "found %llu extents", rc->extents_found);
 
-		if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) {
-			ret = btrfs_wait_ordered_range(rc->data_inode, 0,
-						       (u64)-1);
-			if (ret) {
-				err = ret;
-				goto out;
-			}
-			invalidate_mapping_pages(rc->data_inode->i_mapping,
-						 0, -1);
-			rc->stage = UPDATE_DATA_PTRS;
-		}
 	}
 
 	WARN_ON(rc->block_group->pinned > 0);
@@ -4431,7 +4522,7 @@
 	if (list_empty(&reloc_roots))
 		goto out;
 
-	rc = alloc_reloc_control();
+	rc = alloc_reloc_control(fs_info);
 	if (!rc) {
 		err = -ENOMEM;
 		goto out;
@@ -4486,6 +4577,10 @@
 		goto out_free;
 	}
 	err = btrfs_commit_transaction(trans);
+
+	ret = clean_dirty_subvols(rc);
+	if (ret < 0 && !err)
+		err = ret;
 out_free:
 	kfree(rc);
 out:
@@ -4549,7 +4644,7 @@
 		new_bytenr = ordered->start + (sums->bytenr - disk_bytenr);
 		sums->bytenr = new_bytenr;
 
-		btrfs_add_ordered_sum(inode, ordered, sums);
+		btrfs_add_ordered_sum(ordered, sums);
 	}
 out:
 	btrfs_put_ordered_extent(ordered);
@@ -4622,14 +4717,12 @@
 void btrfs_reloc_pre_snapshot(struct btrfs_pending_snapshot *pending,
 			      u64 *bytes_to_reserve)
 {
-	struct btrfs_root *root;
-	struct reloc_control *rc;
+	struct btrfs_root *root = pending->root;
+	struct reloc_control *rc = root->fs_info->reloc_ctl;
 
-	root = pending->root;
-	if (!root->reloc_root)
+	if (!root->reloc_root || !rc)
 		return;
 
-	rc = root->fs_info->reloc_ctl;
 	if (!rc->merge_reloc_tree)
 		return;
 
@@ -4658,10 +4751,10 @@
 	struct btrfs_root *root = pending->root;
 	struct btrfs_root *reloc_root;
 	struct btrfs_root *new_root;
-	struct reloc_control *rc;
+	struct reloc_control *rc = root->fs_info->reloc_ctl;
 	int ret;
 
-	if (!root->reloc_root)
+	if (!root->reloc_root || !rc)
 		return 0;
 
 	rc = root->fs_info->reloc_ctl;
@@ -4670,7 +4763,7 @@
 	if (rc->merge_reloc_tree) {
 		ret = btrfs_block_rsv_migrate(&pending->block_rsv,
 					      rc->block_rsv,
-					      rc->nodes_relocated, 1);
+					      rc->nodes_relocated, true);
 		if (ret)
 			return ret;
 	}
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index 65bda06..3b17b64 100644
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -9,6 +9,8 @@
 #include "transaction.h"
 #include "disk-io.h"
 #include "print-tree.h"
+#include "qgroup.h"
+#include "space-info.h"
 
 /*
  * Read a root item from the tree. In case we detect a root item smaller then
@@ -21,12 +23,12 @@
 				struct btrfs_root_item *item)
 {
 	uuid_le uuid;
-	int len;
+	u32 len;
 	int need_reset = 0;
 
 	len = btrfs_item_size_nr(eb, slot);
 	read_extent_buffer(eb, item, btrfs_item_ptr_offset(eb, slot),
-			min_t(int, len, (int)sizeof(*item)));
+			   min_t(u32, len, sizeof(*item)));
 	if (len < sizeof(*item))
 		need_reset = 1;
 	if (!need_reset && btrfs_root_generation(item)
@@ -132,18 +134,19 @@
 		return -ENOMEM;
 
 	ret = btrfs_search_slot(trans, root, key, path, 0, 1);
-	if (ret < 0) {
+	if (ret < 0)
+		goto out;
+
+	if (ret > 0) {
+		btrfs_crit(fs_info,
+			"unable to find root key (%llu %u %llu) in tree %llu",
+			key->objectid, key->type, key->offset,
+			root->root_key.objectid);
+		ret = -EUCLEAN;
 		btrfs_abort_transaction(trans, ret);
 		goto out;
 	}
 
-	if (ret != 0) {
-		btrfs_print_leaf(path->nodes[0]);
-		btrfs_crit(fs_info, "unable to update root key %llu %u %llu",
-			   key->objectid, key->type, key->offset);
-		BUG_ON(1);
-	}
-
 	l = path->nodes[0];
 	slot = path->slots[0];
 	ptr = btrfs_item_ptr_offset(l, slot);
@@ -263,8 +266,10 @@
 		if (root) {
 			WARN_ON(!test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
 					  &root->state));
-			if (btrfs_root_refs(&root->root_item) == 0)
+			if (btrfs_root_refs(&root->root_item) == 0) {
+				set_bit(BTRFS_ROOT_DEAD_TREE, &root->state);
 				btrfs_add_dead_root(root);
+			}
 			continue;
 		}
 
@@ -310,8 +315,10 @@
 			break;
 		}
 
-		if (btrfs_root_refs(&root->root_item) == 0)
+		if (btrfs_root_refs(&root->root_item) == 0) {
+			set_bit(BTRFS_ROOT_DEAD_TREE, &root->state);
 			btrfs_add_dead_root(root);
+		}
 	}
 
 	btrfs_free_path(path);
@@ -492,3 +499,57 @@
 	btrfs_set_stack_timespec_nsec(&item->ctime, ct.tv_nsec);
 	spin_unlock(&root->root_item_lock);
 }
+
+/*
+ * btrfs_subvolume_reserve_metadata() - reserve space for subvolume operation
+ * root: the root of the parent directory
+ * rsv: block reservation
+ * items: the number of items that we need do reservation
+ * use_global_rsv: allow fallback to the global block reservation
+ *
+ * This function is used to reserve the space for snapshot/subvolume
+ * creation and deletion. Those operations are different with the
+ * common file/directory operations, they change two fs/file trees
+ * and root tree, the number of items that the qgroup reserves is
+ * different with the free space reservation. So we can not use
+ * the space reservation mechanism in start_transaction().
+ */
+int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
+				     struct btrfs_block_rsv *rsv, int items,
+				     bool use_global_rsv)
+{
+	u64 qgroup_num_bytes = 0;
+	u64 num_bytes;
+	int ret;
+	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
+
+	if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {
+		/* One for parent inode, two for dir entries */
+		qgroup_num_bytes = 3 * fs_info->nodesize;
+		ret = btrfs_qgroup_reserve_meta_prealloc(root,
+				qgroup_num_bytes, true);
+		if (ret)
+			return ret;
+	}
+
+	num_bytes = btrfs_calc_insert_metadata_size(fs_info, items);
+	rsv->space_info = btrfs_find_space_info(fs_info,
+					    BTRFS_BLOCK_GROUP_METADATA);
+	ret = btrfs_block_rsv_add(root, rsv, num_bytes,
+				  BTRFS_RESERVE_FLUSH_ALL);
+
+	if (ret == -ENOSPC && use_global_rsv)
+		ret = btrfs_block_rsv_migrate(global_rsv, rsv, num_bytes, true);
+
+	if (ret && qgroup_num_bytes)
+		btrfs_qgroup_free_meta_prealloc(root, qgroup_num_bytes);
+
+	return ret;
+}
+
+void btrfs_subvolume_release_metadata(struct btrfs_fs_info *fs_info,
+				      struct btrfs_block_rsv *rsv)
+{
+	btrfs_block_rsv_release(fs_info, rsv, (u64)-1);
+}
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 3be1456..f7d4e03 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -6,6 +6,7 @@
 #include <linux/blkdev.h>
 #include <linux/ratelimit.h>
 #include <linux/sched/mm.h>
+#include <crypto/hash.h>
 #include "ctree.h"
 #include "volumes.h"
 #include "disk-io.h"
@@ -17,6 +18,7 @@
 #include "check-integrity.h"
 #include "rcu-string.h"
 #include "raid56.h"
+#include "block-group.h"
 
 /*
  * This is only the first step towards a full-features scrub. It reads all
@@ -339,7 +341,9 @@
 		}
 	}
 
-	/* Insert new lock */
+	/*
+	 * Insert new lock.
+	 */
 	ret = kmalloc(sizeof(*ret), GFP_KERNEL);
 	if (!ret)
 		return ERR_PTR(-ENOMEM);
@@ -568,12 +572,11 @@
 		scrub_free_ctx(sctx);
 }
 
-static noinline_for_stack
-struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
+static noinline_for_stack struct scrub_ctx *scrub_setup_ctx(
+		struct btrfs_fs_info *fs_info, int is_dev_replace)
 {
 	struct scrub_ctx *sctx;
 	int		i;
-	struct btrfs_fs_info *fs_info = dev->fs_info;
 
 	sctx = kzalloc(sizeof(*sctx), GFP_KERNEL);
 	if (!sctx)
@@ -582,7 +585,8 @@
 	sctx->is_dev_replace = is_dev_replace;
 	sctx->pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO;
 	sctx->curr = -1;
-	sctx->fs_info = dev->fs_info;
+	sctx->fs_info = fs_info;
+	INIT_LIST_HEAD(&sctx->csum_list);
 	for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
 		struct scrub_bio *sbio;
 
@@ -607,7 +611,6 @@
 	atomic_set(&sctx->workers_pending, 0);
 	atomic_set(&sctx->cancel_req, 0);
 	sctx->csum_size = btrfs_super_csum_size(fs_info->super_copy);
-	INIT_LIST_HEAD(&sctx->csum_list);
 
 	spin_lock_init(&sctx->list_lock);
 	spin_lock_init(&sctx->stat_lock);
@@ -832,6 +835,7 @@
 	int page_num;
 	int success;
 	bool full_stripe_locked;
+	unsigned int nofs_flag;
 	static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
 				      DEFAULT_RATELIMIT_BURST);
 
@@ -857,6 +861,16 @@
 	dev = sblock_to_check->pagev[0]->dev;
 
 	/*
+	 * We must use GFP_NOFS because the scrub task might be waiting for a
+	 * worker task executing this function and in turn a transaction commit
+	 * might be waiting the scrub task to pause (which needs to wait for all
+	 * the worker tasks to complete before pausing).
+	 * We do allocations in the workers through insert_full_stripe_lock()
+	 * and scrub_add_page_to_wr_bio(), which happens down the call chain of
+	 * this function.
+	 */
+	nofs_flag = memalloc_nofs_save();
+	/*
 	 * For RAID5/6, race can happen for a different device scrub thread.
 	 * For data corruption, Parity and Data threads will both try
 	 * to recovery the data.
@@ -865,6 +879,7 @@
 	 */
 	ret = lock_full_stripe(fs_info, logical, &full_stripe_locked);
 	if (ret < 0) {
+		memalloc_nofs_restore(nofs_flag);
 		spin_lock(&sctx->stat_lock);
 		if (ret == -ENOMEM)
 			sctx->stat.malloc_errors++;
@@ -904,7 +919,7 @@
 	 */
 
 	sblocks_for_recheck = kcalloc(BTRFS_MAX_MIRRORS,
-				      sizeof(*sblocks_for_recheck), GFP_NOFS);
+				      sizeof(*sblocks_for_recheck), GFP_KERNEL);
 	if (!sblocks_for_recheck) {
 		spin_lock(&sctx->stat_lock);
 		sctx->stat.malloc_errors++;
@@ -1124,7 +1139,7 @@
 
 			if (scrub_write_page_to_dev_replace(sblock_other,
 							    page_num) != 0) {
-				btrfs_dev_replace_stats_inc(
+				atomic64_inc(
 					&fs_info->dev_replace.num_write_errors);
 				success = 0;
 			}
@@ -1202,6 +1217,7 @@
 	}
 
 	ret = unlock_full_stripe(fs_info, logical, full_stripe_locked);
+	memalloc_nofs_restore(nofs_flag);
 	if (ret < 0)
 		return ret;
 	return 0;
@@ -1564,8 +1580,7 @@
 		if (btrfsic_submit_bio_wait(bio)) {
 			btrfs_dev_stat_inc_and_print(page_bad->dev,
 				BTRFS_DEV_STAT_WRITE_ERRS);
-			btrfs_dev_replace_stats_inc(
-				&fs_info->dev_replace.num_write_errors);
+			atomic64_inc(&fs_info->dev_replace.num_write_errors);
 			bio_put(bio);
 			return -EIO;
 		}
@@ -1592,8 +1607,7 @@
 
 		ret = scrub_write_page_to_dev_replace(sblock, page_num);
 		if (ret)
-			btrfs_dev_replace_stats_inc(
-				&fs_info->dev_replace.num_write_errors);
+			atomic64_inc(&fs_info->dev_replace.num_write_errors);
 	}
 }
 
@@ -1726,8 +1740,7 @@
 			struct scrub_page *spage = sbio->pagev[i];
 
 			spage->io_error = 1;
-			btrfs_dev_replace_stats_inc(&dev_replace->
-						    num_write_errors);
+			atomic64_inc(&dev_replace->num_write_errors);
 		}
 	}
 
@@ -1776,11 +1789,12 @@
 static int scrub_checksum_data(struct scrub_block *sblock)
 {
 	struct scrub_ctx *sctx = sblock->sctx;
+	struct btrfs_fs_info *fs_info = sctx->fs_info;
+	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
 	u8 csum[BTRFS_CSUM_SIZE];
 	u8 *on_disk_csum;
 	struct page *page;
 	void *buffer;
-	u32 crc = ~(u32)0;
 	u64 len;
 	int index;
 
@@ -1788,6 +1802,9 @@
 	if (!sblock->pagev[0]->have_csum)
 		return 0;
 
+	shash->tfm = fs_info->csum_shash;
+	crypto_shash_init(shash);
+
 	on_disk_csum = sblock->pagev[0]->csum;
 	page = sblock->pagev[0]->page;
 	buffer = kmap_atomic(page);
@@ -1797,7 +1814,7 @@
 	for (;;) {
 		u64 l = min_t(u64, len, PAGE_SIZE);
 
-		crc = btrfs_csum_data(buffer, crc, l);
+		crypto_shash_update(shash, buffer, l);
 		kunmap_atomic(buffer);
 		len -= l;
 		if (len == 0)
@@ -1809,7 +1826,7 @@
 		buffer = kmap_atomic(page);
 	}
 
-	btrfs_csum_final(crc, csum);
+	crypto_shash_final(shash, csum);
 	if (memcmp(csum, on_disk_csum, sctx->csum_size))
 		sblock->checksum_error = 1;
 
@@ -1821,16 +1838,19 @@
 	struct scrub_ctx *sctx = sblock->sctx;
 	struct btrfs_header *h;
 	struct btrfs_fs_info *fs_info = sctx->fs_info;
+	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
 	u8 calculated_csum[BTRFS_CSUM_SIZE];
 	u8 on_disk_csum[BTRFS_CSUM_SIZE];
 	struct page *page;
 	void *mapped_buffer;
 	u64 mapped_size;
 	void *p;
-	u32 crc = ~(u32)0;
 	u64 len;
 	int index;
 
+	shash->tfm = fs_info->csum_shash;
+	crypto_shash_init(shash);
+
 	BUG_ON(sblock->page_count < 1);
 	page = sblock->pagev[0]->page;
 	mapped_buffer = kmap_atomic(page);
@@ -1864,7 +1884,7 @@
 	for (;;) {
 		u64 l = min_t(u64, len, mapped_size);
 
-		crc = btrfs_csum_data(p, crc, l);
+		crypto_shash_update(shash, p, l);
 		kunmap_atomic(mapped_buffer);
 		len -= l;
 		if (len == 0)
@@ -1878,7 +1898,7 @@
 		p = mapped_buffer;
 	}
 
-	btrfs_csum_final(crc, calculated_csum);
+	crypto_shash_final(shash, calculated_csum);
 	if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
 		sblock->checksum_error = 1;
 
@@ -1889,18 +1909,22 @@
 {
 	struct btrfs_super_block *s;
 	struct scrub_ctx *sctx = sblock->sctx;
+	struct btrfs_fs_info *fs_info = sctx->fs_info;
+	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
 	u8 calculated_csum[BTRFS_CSUM_SIZE];
 	u8 on_disk_csum[BTRFS_CSUM_SIZE];
 	struct page *page;
 	void *mapped_buffer;
 	u64 mapped_size;
 	void *p;
-	u32 crc = ~(u32)0;
 	int fail_gen = 0;
 	int fail_cor = 0;
 	u64 len;
 	int index;
 
+	shash->tfm = fs_info->csum_shash;
+	crypto_shash_init(shash);
+
 	BUG_ON(sblock->page_count < 1);
 	page = sblock->pagev[0]->page;
 	mapped_buffer = kmap_atomic(page);
@@ -1923,7 +1947,7 @@
 	for (;;) {
 		u64 l = min_t(u64, len, mapped_size);
 
-		crc = btrfs_csum_data(p, crc, l);
+		crypto_shash_update(shash, p, l);
 		kunmap_atomic(mapped_buffer);
 		len -= l;
 		if (len == 0)
@@ -1937,7 +1961,7 @@
 		p = mapped_buffer;
 	}
 
-	btrfs_csum_final(crc, calculated_csum);
+	crypto_shash_final(shash, calculated_csum);
 	if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
 		++fail_cor;
 
@@ -2437,7 +2461,7 @@
 	ASSERT(index < UINT_MAX);
 
 	num_sectors = sum->len / sctx->fs_info->sectorsize;
-	memcpy(csum, sum->sums + index, sctx->csum_size);
+	memcpy(csum, sum->sums + index * sctx->csum_size, sctx->csum_size);
 	if (index == num_sectors - 1) {
 		list_del(&sum->list);
 		kfree(sum);
@@ -2649,18 +2673,18 @@
 	u64 last_offset;
 	u32 stripe_index;
 	u32 rot;
+	const int data_stripes = nr_data_stripes(map);
 
-	last_offset = (physical - map->stripes[num].physical) *
-		      nr_data_stripes(map);
+	last_offset = (physical - map->stripes[num].physical) * data_stripes;
 	if (stripe_start)
 		*stripe_start = last_offset;
 
 	*offset = last_offset;
-	for (i = 0; i < nr_data_stripes(map); i++) {
+	for (i = 0; i < data_stripes; i++) {
 		*offset = last_offset + i * map->stripe_len;
 
 		stripe_nr = div64_u64(*offset, map->stripe_len);
-		stripe_nr = div_u64(stripe_nr, nr_data_stripes(map));
+		stripe_nr = div_u64(stripe_nr, data_stripes);
 
 		/* Work out the disk rotation on this stripe-set */
 		stripe_nr = div_u64_rem(stripe_nr, map->num_stripes, &rot);
@@ -3022,8 +3046,7 @@
 static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 					   struct map_lookup *map,
 					   struct btrfs_device *scrub_dev,
-					   int num, u64 base, u64 length,
-					   int is_dev_replace)
+					   int num, u64 base, u64 length)
 {
 	struct btrfs_path *path, *ppath;
 	struct btrfs_fs_info *fs_info = sctx->fs_info;
@@ -3069,7 +3092,7 @@
 		offset = map->stripe_len * (num / map->sub_stripes);
 		increment = map->stripe_len * factor;
 		mirror_num = num % map->sub_stripes + 1;
-	} else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
+	} else if (map->type & BTRFS_BLOCK_GROUP_RAID1_MASK) {
 		increment = map->stripe_len;
 		mirror_num = num % map->num_stripes + 1;
 	} else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
@@ -3299,7 +3322,7 @@
 			extent_physical = extent_logical - logical + physical;
 			extent_dev = scrub_dev;
 			extent_mirror_num = mirror_num;
-			if (is_dev_replace)
+			if (sctx->is_dev_replace)
 				scrub_remap_extent(fs_info, extent_logical,
 						   extent_len, &extent_physical,
 						   &extent_dev,
@@ -3397,19 +3420,18 @@
 					  struct btrfs_device *scrub_dev,
 					  u64 chunk_offset, u64 length,
 					  u64 dev_offset,
-					  struct btrfs_block_group_cache *cache,
-					  int is_dev_replace)
+					  struct btrfs_block_group_cache *cache)
 {
 	struct btrfs_fs_info *fs_info = sctx->fs_info;
-	struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
+	struct extent_map_tree *map_tree = &fs_info->mapping_tree;
 	struct map_lookup *map;
 	struct extent_map *em;
 	int i;
 	int ret = 0;
 
-	read_lock(&map_tree->map_tree.lock);
-	em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
-	read_unlock(&map_tree->map_tree.lock);
+	read_lock(&map_tree->lock);
+	em = lookup_extent_mapping(map_tree, chunk_offset, 1);
+	read_unlock(&map_tree->lock);
 
 	if (!em) {
 		/*
@@ -3435,8 +3457,7 @@
 		if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
 		    map->stripes[i].physical == dev_offset) {
 			ret = scrub_stripe(sctx, map, scrub_dev, i,
-					   chunk_offset, length,
-					   is_dev_replace);
+					   chunk_offset, length);
 			if (ret)
 				goto out;
 		}
@@ -3449,8 +3470,7 @@
 
 static noinline_for_stack
 int scrub_enumerate_chunks(struct scrub_ctx *sctx,
-			   struct btrfs_device *scrub_dev, u64 start, u64 end,
-			   int is_dev_replace)
+			   struct btrfs_device *scrub_dev, u64 start, u64 end)
 {
 	struct btrfs_dev_extent *dev_extent = NULL;
 	struct btrfs_path *path;
@@ -3544,10 +3564,10 @@
 		 */
 		scrub_pause_on(fs_info);
 		ret = btrfs_inc_block_group_ro(cache);
-		if (!ret && is_dev_replace) {
+		if (!ret && sctx->is_dev_replace) {
 			/*
 			 * If we are doing a device replace wait for any tasks
-			 * that started dellaloc right before we set the block
+			 * that started delalloc right before we set the block
 			 * group to RO mode, as they might have just allocated
 			 * an extent from it or decided they could do a nocow
 			 * write. And if any such tasks did that, wait for their
@@ -3603,13 +3623,14 @@
 			break;
 		}
 
-		btrfs_dev_replace_write_lock(&fs_info->dev_replace);
+		down_write(&fs_info->dev_replace.rwsem);
 		dev_replace->cursor_right = found_key.offset + length;
 		dev_replace->cursor_left = found_key.offset;
 		dev_replace->item_needs_writeback = 1;
-		btrfs_dev_replace_write_unlock(&fs_info->dev_replace);
+		up_write(&dev_replace->rwsem);
+
 		ret = scrub_chunk(sctx, scrub_dev, chunk_offset, length,
-				  found_key.offset, cache, is_dev_replace);
+				  found_key.offset, cache);
 
 		/*
 		 * flush, submit all pending read and write bios, afterwards
@@ -3643,10 +3664,10 @@
 
 		scrub_pause_off(fs_info);
 
-		btrfs_dev_replace_write_lock(&fs_info->dev_replace);
+		down_write(&fs_info->dev_replace.rwsem);
 		dev_replace->cursor_left = dev_replace->cursor_right;
 		dev_replace->item_needs_writeback = 1;
-		btrfs_dev_replace_write_unlock(&fs_info->dev_replace);
+		up_write(&fs_info->dev_replace.rwsem);
 
 		if (ro_set)
 			btrfs_dec_block_group_ro(cache);
@@ -3670,7 +3691,7 @@
 		btrfs_put_block_group(cache);
 		if (ret)
 			break;
-		if (is_dev_replace &&
+		if (sctx->is_dev_replace &&
 		    atomic64_read(&dev_replace->num_write_errors) > 0) {
 			ret = -EIO;
 			break;
@@ -3733,25 +3754,33 @@
 	unsigned int flags = WQ_FREEZABLE | WQ_UNBOUND;
 	int max_active = fs_info->thread_pool_size;
 
-	if (fs_info->scrub_workers_refcnt == 0) {
+	lockdep_assert_held(&fs_info->scrub_lock);
+
+	if (refcount_read(&fs_info->scrub_workers_refcnt) == 0) {
+		ASSERT(fs_info->scrub_workers == NULL);
 		fs_info->scrub_workers = btrfs_alloc_workqueue(fs_info, "scrub",
 				flags, is_dev_replace ? 1 : max_active, 4);
 		if (!fs_info->scrub_workers)
 			goto fail_scrub_workers;
 
+		ASSERT(fs_info->scrub_wr_completion_workers == NULL);
 		fs_info->scrub_wr_completion_workers =
 			btrfs_alloc_workqueue(fs_info, "scrubwrc", flags,
 					      max_active, 2);
 		if (!fs_info->scrub_wr_completion_workers)
 			goto fail_scrub_wr_completion_workers;
 
+		ASSERT(fs_info->scrub_parity_workers == NULL);
 		fs_info->scrub_parity_workers =
 			btrfs_alloc_workqueue(fs_info, "scrubparity", flags,
 					      max_active, 2);
 		if (!fs_info->scrub_parity_workers)
 			goto fail_scrub_parity_workers;
+
+		refcount_set(&fs_info->scrub_workers_refcnt, 1);
+	} else {
+		refcount_inc(&fs_info->scrub_workers_refcnt);
 	}
-	++fs_info->scrub_workers_refcnt;
 	return 0;
 
 fail_scrub_parity_workers:
@@ -3762,16 +3791,6 @@
 	return -ENOMEM;
 }
 
-static noinline_for_stack void scrub_workers_put(struct btrfs_fs_info *fs_info)
-{
-	if (--fs_info->scrub_workers_refcnt == 0) {
-		btrfs_destroy_workqueue(fs_info->scrub_workers);
-		btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
-		btrfs_destroy_workqueue(fs_info->scrub_parity_workers);
-	}
-	WARN_ON(fs_info->scrub_workers_refcnt < 0);
-}
-
 int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
 		    u64 end, struct btrfs_scrub_progress *progress,
 		    int readonly, int is_dev_replace)
@@ -3779,9 +3798,13 @@
 	struct scrub_ctx *sctx;
 	int ret;
 	struct btrfs_device *dev;
+	unsigned int nofs_flag;
+	struct btrfs_workqueue *scrub_workers = NULL;
+	struct btrfs_workqueue *scrub_wr_comp = NULL;
+	struct btrfs_workqueue *scrub_parity = NULL;
 
 	if (btrfs_fs_closing(fs_info))
-		return -EINVAL;
+		return -EAGAIN;
 
 	if (fs_info->nodesize > BTRFS_STRIPE_LEN) {
 		/*
@@ -3820,13 +3843,18 @@
 		return -EINVAL;
 	}
 
+	/* Allocate outside of device_list_mutex */
+	sctx = scrub_setup_ctx(fs_info, is_dev_replace);
+	if (IS_ERR(sctx))
+		return PTR_ERR(sctx);
 
 	mutex_lock(&fs_info->fs_devices->device_list_mutex);
-	dev = btrfs_find_device(fs_info, devid, NULL, NULL);
+	dev = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL, true);
 	if (!dev || (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state) &&
 		     !is_dev_replace)) {
 		mutex_unlock(&fs_info->fs_devices->device_list_mutex);
-		return -ENODEV;
+		ret = -ENODEV;
+		goto out_free_ctx;
 	}
 
 	if (!is_dev_replace && !readonly &&
@@ -3834,7 +3862,8 @@
 		mutex_unlock(&fs_info->fs_devices->device_list_mutex);
 		btrfs_err_in_rcu(fs_info, "scrub: device %s is not writable",
 				rcu_str_deref(dev->name));
-		return -EROFS;
+		ret = -EROFS;
+		goto out_free_ctx;
 	}
 
 	mutex_lock(&fs_info->scrub_lock);
@@ -3842,34 +3871,29 @@
 	    test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &dev->dev_state)) {
 		mutex_unlock(&fs_info->scrub_lock);
 		mutex_unlock(&fs_info->fs_devices->device_list_mutex);
-		return -EIO;
+		ret = -EIO;
+		goto out_free_ctx;
 	}
 
-	btrfs_dev_replace_read_lock(&fs_info->dev_replace);
+	down_read(&fs_info->dev_replace.rwsem);
 	if (dev->scrub_ctx ||
 	    (!is_dev_replace &&
 	     btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
-		btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
+		up_read(&fs_info->dev_replace.rwsem);
 		mutex_unlock(&fs_info->scrub_lock);
 		mutex_unlock(&fs_info->fs_devices->device_list_mutex);
-		return -EINPROGRESS;
+		ret = -EINPROGRESS;
+		goto out_free_ctx;
 	}
-	btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
+	up_read(&fs_info->dev_replace.rwsem);
 
 	ret = scrub_workers_get(fs_info, is_dev_replace);
 	if (ret) {
 		mutex_unlock(&fs_info->scrub_lock);
 		mutex_unlock(&fs_info->fs_devices->device_list_mutex);
-		return ret;
+		goto out_free_ctx;
 	}
 
-	sctx = scrub_setup_ctx(dev, is_dev_replace);
-	if (IS_ERR(sctx)) {
-		mutex_unlock(&fs_info->scrub_lock);
-		mutex_unlock(&fs_info->fs_devices->device_list_mutex);
-		scrub_workers_put(fs_info);
-		return PTR_ERR(sctx);
-	}
 	sctx->readonly = readonly;
 	dev->scrub_ctx = sctx;
 	mutex_unlock(&fs_info->fs_devices->device_list_mutex);
@@ -3882,7 +3906,18 @@
 	atomic_inc(&fs_info->scrubs_running);
 	mutex_unlock(&fs_info->scrub_lock);
 
+	/*
+	 * In order to avoid deadlock with reclaim when there is a transaction
+	 * trying to pause scrub, make sure we use GFP_NOFS for all the
+	 * allocations done at btrfs_scrub_pages() and scrub_pages_for_parity()
+	 * invoked by our callees. The pausing request is done when the
+	 * transaction commit starts, and it blocks the transaction until scrub
+	 * is paused (done at specific points at scrub_stripe() or right above
+	 * before incrementing fs_info->scrubs_running).
+	 */
+	nofs_flag = memalloc_nofs_save();
 	if (!is_dev_replace) {
+		btrfs_info(fs_info, "scrub: started on devid %llu", devid);
 		/*
 		 * by holding device list mutex, we can
 		 * kick off writing super in log tree sync.
@@ -3893,8 +3928,8 @@
 	}
 
 	if (!ret)
-		ret = scrub_enumerate_chunks(sctx, dev, start, end,
-					     is_dev_replace);
+		ret = scrub_enumerate_chunks(sctx, dev, start, end);
+	memalloc_nofs_restore(nofs_flag);
 
 	wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
 	atomic_dec(&fs_info->scrubs_running);
@@ -3905,14 +3940,34 @@
 	if (progress)
 		memcpy(progress, &sctx->stat, sizeof(*progress));
 
+	if (!is_dev_replace)
+		btrfs_info(fs_info, "scrub: %s on devid %llu with status: %d",
+			ret ? "not finished" : "finished", devid, ret);
+
 	mutex_lock(&fs_info->scrub_lock);
 	dev->scrub_ctx = NULL;
-	scrub_workers_put(fs_info);
+	if (refcount_dec_and_test(&fs_info->scrub_workers_refcnt)) {
+		scrub_workers = fs_info->scrub_workers;
+		scrub_wr_comp = fs_info->scrub_wr_completion_workers;
+		scrub_parity = fs_info->scrub_parity_workers;
+
+		fs_info->scrub_workers = NULL;
+		fs_info->scrub_wr_completion_workers = NULL;
+		fs_info->scrub_parity_workers = NULL;
+	}
 	mutex_unlock(&fs_info->scrub_lock);
 
+	btrfs_destroy_workqueue(scrub_workers);
+	btrfs_destroy_workqueue(scrub_wr_comp);
+	btrfs_destroy_workqueue(scrub_parity);
 	scrub_put_ctx(sctx);
 
 	return ret;
+
+out_free_ctx:
+	scrub_free_ctx(sctx);
+
+	return ret;
 }
 
 void btrfs_scrub_pause(struct btrfs_fs_info *fs_info)
@@ -3957,9 +4012,9 @@
 	return 0;
 }
 
-int btrfs_scrub_cancel_dev(struct btrfs_fs_info *fs_info,
-			   struct btrfs_device *dev)
+int btrfs_scrub_cancel_dev(struct btrfs_device *dev)
 {
+	struct btrfs_fs_info *fs_info = dev->fs_info;
 	struct scrub_ctx *sctx;
 
 	mutex_lock(&fs_info->scrub_lock);
@@ -3987,7 +4042,7 @@
 	struct scrub_ctx *sctx = NULL;
 
 	mutex_lock(&fs_info->fs_devices->device_list_mutex);
-	dev = btrfs_find_device(fs_info, devid, NULL, NULL);
+	dev = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL, true);
 	if (dev)
 		sctx = dev->scrub_ctx;
 	if (sctx)
diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 84cb6e5..123ac54 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -260,6 +260,21 @@
 	char name[];
 };
 
+#define ADVANCE							1
+#define ADVANCE_ONLY_NEXT					-1
+
+enum btrfs_compare_tree_result {
+	BTRFS_COMPARE_TREE_NEW,
+	BTRFS_COMPARE_TREE_DELETED,
+	BTRFS_COMPARE_TREE_CHANGED,
+	BTRFS_COMPARE_TREE_SAME,
+};
+typedef int (*btrfs_changed_cb_t)(struct btrfs_path *left_path,
+				  struct btrfs_path *right_path,
+				  struct btrfs_key *key,
+				  enum btrfs_compare_tree_result result,
+				  void *ctx);
+
 __cold
 static void inconsistent_snapshot_error(struct send_ctx *sctx,
 					enum btrfs_compare_tree_result result,
@@ -686,7 +701,7 @@
 	hdr->len = cpu_to_le32(sctx->send_size - sizeof(*hdr));
 	hdr->crc = 0;
 
-	crc = crc32c(0, (unsigned char *)sctx->send_buf, sctx->send_size);
+	crc = btrfs_crc32c(0, (unsigned char *)sctx->send_buf, sctx->send_size);
 	hdr->crc = cpu_to_le32(crc);
 
 	ret = write_buf(sctx->send_filp, sctx->send_buf, sctx->send_size,
@@ -1160,7 +1175,6 @@
 struct backref_ctx {
 	struct send_ctx *sctx;
 
-	struct btrfs_path *path;
 	/* number of total found references */
 	u64 found;
 
@@ -1186,9 +1200,9 @@
 	u64 root = (u64)(uintptr_t)key;
 	struct clone_root *cr = (struct clone_root *)elt;
 
-	if (root < cr->root->objectid)
+	if (root < cr->root->root_key.objectid)
 		return -1;
-	if (root > cr->root->objectid)
+	if (root > cr->root->root_key.objectid)
 		return 1;
 	return 0;
 }
@@ -1198,9 +1212,9 @@
 	struct clone_root *cr1 = (struct clone_root *)e1;
 	struct clone_root *cr2 = (struct clone_root *)e2;
 
-	if (cr1->root->objectid < cr2->root->objectid)
+	if (cr1->root->root_key.objectid < cr2->root->root_key.objectid)
 		return -1;
-	if (cr1->root->objectid > cr2->root->objectid)
+	if (cr1->root->root_key.objectid > cr2->root->root_key.objectid)
 		return 1;
 	return 0;
 }
@@ -1213,8 +1227,6 @@
 {
 	struct backref_ctx *bctx = ctx_;
 	struct clone_root *found;
-	int ret;
-	u64 i_size;
 
 	/* First check if the root is in the list of accepted clone sources */
 	found = bsearch((void *)(uintptr_t)root, bctx->sctx->clone_roots,
@@ -1231,19 +1243,6 @@
 	}
 
 	/*
-	 * There are inodes that have extents that lie behind its i_size. Don't
-	 * accept clones from these extents.
-	 */
-	ret = __get_inode_info(found->root, bctx->path, ino, &i_size, NULL, NULL,
-			       NULL, NULL, NULL);
-	btrfs_release_path(bctx->path);
-	if (ret < 0)
-		return ret;
-
-	if (offset + bctx->data_offset + bctx->extent_len > i_size)
-		return 0;
-
-	/*
 	 * Make sure we don't consider clones from send_root that are
 	 * behind the current inode/offset.
 	 */
@@ -1319,8 +1318,6 @@
 		goto out;
 	}
 
-	backref_ctx->path = tmp_path;
-
 	if (data_offset >= ino_size) {
 		/*
 		 * There may be extents that lie behind the file's size.
@@ -1693,12 +1690,8 @@
 
 	di = btrfs_lookup_dir_item(NULL, root, path,
 			dir, name, name_len, 0);
-	if (!di) {
-		ret = -ENOENT;
-		goto out;
-	}
-	if (IS_ERR(di)) {
-		ret = PTR_ERR(di);
+	if (IS_ERR_OR_NULL(di)) {
+		ret = di ? PTR_ERR(di) : -ENOENT;
 		goto out;
 	}
 	btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
@@ -2242,7 +2235,7 @@
  * inodes "orphan" name instead of the real name and stop. Same with new inodes
  * that were not created yet and overwritten inodes/refs.
  *
- * When do we have have orphan inodes:
+ * When do we have orphan inodes:
  * 1. When an inode is freshly created and thus no valid refs are available yet
  * 2. When a directory lost all it's refs (deleted) but still has dir items
  *    inside which were not processed yet (pending for move/delete). If anyone
@@ -2346,7 +2339,7 @@
 		return -ENOMEM;
 	}
 
-	key.objectid = send_root->objectid;
+	key.objectid = send_root->root_key.objectid;
 	key.type = BTRFS_ROOT_BACKREF_KEY;
 	key.offset = 0;
 
@@ -2362,7 +2355,7 @@
 	leaf = path->nodes[0];
 	btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
 	if (key.type != BTRFS_ROOT_BACKREF_KEY ||
-	    key.objectid != send_root->objectid) {
+	    key.objectid != send_root->root_key.objectid) {
 		ret = -ENOENT;
 		goto out;
 	}
@@ -3858,7 +3851,7 @@
 		/*
 		 * We may have refs where the parent directory does not exist
 		 * yet. This happens if the parent directories inum is higher
-		 * the the current inum. To handle this case, we create the
+		 * than the current inum. To handle this case, we create the
 		 * parent directory out of order. But we need to check if this
 		 * did already happen before due to other refs in the same dir.
 		 */
@@ -4779,7 +4772,7 @@
 	struct btrfs_key key;
 	pgoff_t index = offset >> PAGE_SHIFT;
 	pgoff_t last_index;
-	unsigned pg_offset = offset & ~PAGE_MASK;
+	unsigned pg_offset = offset_in_page(offset);
 	ssize_t ret = 0;
 
 	key.objectid = sctx->cur_ino;
@@ -4912,8 +4905,8 @@
 
 	btrfs_debug(sctx->send_root->fs_info,
 		    "send_clone offset=%llu, len=%d, clone_root=%llu, clone_inode=%llu, clone_offset=%llu",
-		    offset, len, clone_root->root->objectid, clone_root->ino,
-		    clone_root->offset);
+		    offset, len, clone_root->root->root_key.objectid,
+		    clone_root->ino, clone_root->offset);
 
 	p = fs_path_alloc();
 	if (!p)
@@ -5021,6 +5014,12 @@
 	if (offset >= sctx->cur_inode_size)
 		return 0;
 
+	/*
+	 * Don't go beyond the inode's i_size due to prealloc extents that start
+	 * after the i_size.
+	 */
+	end = min_t(u64, end, sctx->cur_inode_size);
+
 	if (sctx->flags & BTRFS_SEND_FLAG_NO_FILE_DATA)
 		return send_update_extent(sctx, offset, end - offset);
 
@@ -5086,6 +5085,7 @@
 	struct btrfs_path *path;
 	struct btrfs_key key;
 	int ret;
+	u64 clone_src_i_size = 0;
 
 	/*
 	 * Prevent cloning from a zero offset with a length matching the sector
@@ -5111,6 +5111,16 @@
 		return -ENOMEM;
 
 	/*
+	 * There are inodes that have extents that lie behind its i_size. Don't
+	 * accept clones from these extents.
+	 */
+	ret = __get_inode_info(clone_root->root, path, clone_root->ino,
+			       &clone_src_i_size, NULL, NULL, NULL, NULL, NULL);
+	btrfs_release_path(path);
+	if (ret < 0)
+		goto out;
+
+	/*
 	 * We can't send a clone operation for the entire range if we find
 	 * extent items in the respective range in the source file that
 	 * refer to different extents or if we find holes.
@@ -5152,6 +5162,7 @@
 		u8 type;
 		u64 ext_len;
 		u64 clone_len;
+		u64 clone_data_offset;
 
 		if (slot >= btrfs_header_nritems(leaf)) {
 			ret = btrfs_next_leaf(clone_root->root, path);
@@ -5205,13 +5216,73 @@
 		if (key.offset >= clone_root->offset + len)
 			break;
 
+		if (key.offset >= clone_src_i_size)
+			break;
+
+		if (key.offset + ext_len > clone_src_i_size)
+			ext_len = clone_src_i_size - key.offset;
+
+		clone_data_offset = btrfs_file_extent_offset(leaf, ei);
+		if (btrfs_file_extent_disk_bytenr(leaf, ei) == disk_byte) {
+			clone_root->offset = key.offset;
+			if (clone_data_offset < data_offset &&
+				clone_data_offset + ext_len > data_offset) {
+				u64 extent_offset;
+
+				extent_offset = data_offset - clone_data_offset;
+				ext_len -= extent_offset;
+				clone_data_offset += extent_offset;
+				clone_root->offset += extent_offset;
+			}
+		}
+
 		clone_len = min_t(u64, ext_len, len);
 
 		if (btrfs_file_extent_disk_bytenr(leaf, ei) == disk_byte &&
-		    btrfs_file_extent_offset(leaf, ei) == data_offset)
-			ret = send_clone(sctx, offset, clone_len, clone_root);
-		else
+		    clone_data_offset == data_offset) {
+			const u64 src_end = clone_root->offset + clone_len;
+			const u64 sectorsize = SZ_64K;
+
+			/*
+			 * We can't clone the last block, when its size is not
+			 * sector size aligned, into the middle of a file. If we
+			 * do so, the receiver will get a failure (-EINVAL) when
+			 * trying to clone or will silently corrupt the data in
+			 * the destination file if it's on a kernel without the
+			 * fix introduced by commit ac765f83f1397646
+			 * ("Btrfs: fix data corruption due to cloning of eof
+			 * block).
+			 *
+			 * So issue a clone of the aligned down range plus a
+			 * regular write for the eof block, if we hit that case.
+			 *
+			 * Also, we use the maximum possible sector size, 64K,
+			 * because we don't know what's the sector size of the
+			 * filesystem that receives the stream, so we have to
+			 * assume the largest possible sector size.
+			 */
+			if (src_end == clone_src_i_size &&
+			    !IS_ALIGNED(src_end, sectorsize) &&
+			    offset + clone_len < sctx->cur_inode_size) {
+				u64 slen;
+
+				slen = ALIGN_DOWN(src_end - clone_root->offset,
+						  sectorsize);
+				if (slen > 0) {
+					ret = send_clone(sctx, offset, slen,
+							 clone_root);
+					if (ret < 0)
+						goto out;
+				}
+				ret = send_extent_data(sctx, offset + slen,
+						       clone_len - slen);
+			} else {
+				ret = send_clone(sctx, offset, clone_len,
+						 clone_root);
+			}
+		} else {
 			ret = send_extent_data(sctx, offset, clone_len);
+		}
 
 		if (ret < 0)
 			goto out;
@@ -6266,68 +6337,21 @@
 {
 	int ret = 0;
 
-	if (sctx->cur_ino != sctx->cmp_key->objectid) {
-
-		if (result == BTRFS_COMPARE_TREE_CHANGED) {
-			struct extent_buffer *leaf_l;
-			struct extent_buffer *leaf_r;
-			struct btrfs_file_extent_item *ei_l;
-			struct btrfs_file_extent_item *ei_r;
-
-			leaf_l = sctx->left_path->nodes[0];
-			leaf_r = sctx->right_path->nodes[0];
-			ei_l = btrfs_item_ptr(leaf_l,
-					      sctx->left_path->slots[0],
-					      struct btrfs_file_extent_item);
-			ei_r = btrfs_item_ptr(leaf_r,
-					      sctx->right_path->slots[0],
-					      struct btrfs_file_extent_item);
-
-			/*
-			 * We may have found an extent item that has changed
-			 * only its disk_bytenr field and the corresponding
-			 * inode item was not updated. This case happens due to
-			 * very specific timings during relocation when a leaf
-			 * that contains file extent items is COWed while
-			 * relocation is ongoing and its in the stage where it
-			 * updates data pointers. So when this happens we can
-			 * safely ignore it since we know it's the same extent,
-			 * but just at different logical and physical locations
-			 * (when an extent is fully replaced with a new one, we
-			 * know the generation number must have changed too,
-			 * since snapshot creation implies committing the current
-			 * transaction, and the inode item must have been updated
-			 * as well).
-			 * This replacement of the disk_bytenr happens at
-			 * relocation.c:replace_file_extents() through
-			 * relocation.c:btrfs_reloc_cow_block().
-			 */
-			if (btrfs_file_extent_generation(leaf_l, ei_l) ==
-			    btrfs_file_extent_generation(leaf_r, ei_r) &&
-			    btrfs_file_extent_ram_bytes(leaf_l, ei_l) ==
-			    btrfs_file_extent_ram_bytes(leaf_r, ei_r) &&
-			    btrfs_file_extent_compression(leaf_l, ei_l) ==
-			    btrfs_file_extent_compression(leaf_r, ei_r) &&
-			    btrfs_file_extent_encryption(leaf_l, ei_l) ==
-			    btrfs_file_extent_encryption(leaf_r, ei_r) &&
-			    btrfs_file_extent_other_encoding(leaf_l, ei_l) ==
-			    btrfs_file_extent_other_encoding(leaf_r, ei_r) &&
-			    btrfs_file_extent_type(leaf_l, ei_l) ==
-			    btrfs_file_extent_type(leaf_r, ei_r) &&
-			    btrfs_file_extent_disk_bytenr(leaf_l, ei_l) !=
-			    btrfs_file_extent_disk_bytenr(leaf_r, ei_r) &&
-			    btrfs_file_extent_disk_num_bytes(leaf_l, ei_l) ==
-			    btrfs_file_extent_disk_num_bytes(leaf_r, ei_r) &&
-			    btrfs_file_extent_offset(leaf_l, ei_l) ==
-			    btrfs_file_extent_offset(leaf_r, ei_r) &&
-			    btrfs_file_extent_num_bytes(leaf_l, ei_l) ==
-			    btrfs_file_extent_num_bytes(leaf_r, ei_r))
-				return 0;
-		}
-
-		inconsistent_snapshot_error(sctx, result, "extent");
-		return -EIO;
-	}
+	/*
+	 * We have found an extent item that changed without the inode item
+	 * having changed. This can happen either after relocation (where the
+	 * disk_bytenr of an extent item is replaced at
+	 * relocation.c:replace_file_extents()) or after deduplication into a
+	 * file in both the parent and send snapshots (where an extent item can
+	 * get modified or replaced with a new one). Note that deduplication
+	 * updates the inode item, but it only changes the iversion (sequence
+	 * field in the inode item) of the inode, so if a file is deduplicated
+	 * the same amount of times in both the parent and send snapshots, its
+	 * iversion becames the same in both snapshots, whence the inode item is
+	 * the same on both snapshots.
+	 */
+	if (sctx->cur_ino != sctx->cmp_key->objectid)
+		return 0;
 
 	if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) {
 		if (result != BTRFS_COMPARE_TREE_DELETED)
@@ -6505,6 +6529,366 @@
 	return ret;
 }
 
+static int tree_move_down(struct btrfs_path *path, int *level)
+{
+	struct extent_buffer *eb;
+
+	BUG_ON(*level == 0);
+	eb = btrfs_read_node_slot(path->nodes[*level], path->slots[*level]);
+	if (IS_ERR(eb))
+		return PTR_ERR(eb);
+
+	path->nodes[*level - 1] = eb;
+	path->slots[*level - 1] = 0;
+	(*level)--;
+	return 0;
+}
+
+static int tree_move_next_or_upnext(struct btrfs_path *path,
+				    int *level, int root_level)
+{
+	int ret = 0;
+	int nritems;
+	nritems = btrfs_header_nritems(path->nodes[*level]);
+
+	path->slots[*level]++;
+
+	while (path->slots[*level] >= nritems) {
+		if (*level == root_level)
+			return -1;
+
+		/* move upnext */
+		path->slots[*level] = 0;
+		free_extent_buffer(path->nodes[*level]);
+		path->nodes[*level] = NULL;
+		(*level)++;
+		path->slots[*level]++;
+
+		nritems = btrfs_header_nritems(path->nodes[*level]);
+		ret = 1;
+	}
+	return ret;
+}
+
+/*
+ * Returns 1 if it had to move up and next. 0 is returned if it moved only next
+ * or down.
+ */
+static int tree_advance(struct btrfs_path *path,
+			int *level, int root_level,
+			int allow_down,
+			struct btrfs_key *key)
+{
+	int ret;
+
+	if (*level == 0 || !allow_down) {
+		ret = tree_move_next_or_upnext(path, level, root_level);
+	} else {
+		ret = tree_move_down(path, level);
+	}
+	if (ret >= 0) {
+		if (*level == 0)
+			btrfs_item_key_to_cpu(path->nodes[*level], key,
+					path->slots[*level]);
+		else
+			btrfs_node_key_to_cpu(path->nodes[*level], key,
+					path->slots[*level]);
+	}
+	return ret;
+}
+
+static int tree_compare_item(struct btrfs_path *left_path,
+			     struct btrfs_path *right_path,
+			     char *tmp_buf)
+{
+	int cmp;
+	int len1, len2;
+	unsigned long off1, off2;
+
+	len1 = btrfs_item_size_nr(left_path->nodes[0], left_path->slots[0]);
+	len2 = btrfs_item_size_nr(right_path->nodes[0], right_path->slots[0]);
+	if (len1 != len2)
+		return 1;
+
+	off1 = btrfs_item_ptr_offset(left_path->nodes[0], left_path->slots[0]);
+	off2 = btrfs_item_ptr_offset(right_path->nodes[0],
+				right_path->slots[0]);
+
+	read_extent_buffer(left_path->nodes[0], tmp_buf, off1, len1);
+
+	cmp = memcmp_extent_buffer(right_path->nodes[0], tmp_buf, off2, len1);
+	if (cmp)
+		return 1;
+	return 0;
+}
+
+/*
+ * This function compares two trees and calls the provided callback for
+ * every changed/new/deleted item it finds.
+ * If shared tree blocks are encountered, whole subtrees are skipped, making
+ * the compare pretty fast on snapshotted subvolumes.
+ *
+ * This currently works on commit roots only. As commit roots are read only,
+ * we don't do any locking. The commit roots are protected with transactions.
+ * Transactions are ended and rejoined when a commit is tried in between.
+ *
+ * This function checks for modifications done to the trees while comparing.
+ * If it detects a change, it aborts immediately.
+ */
+static int btrfs_compare_trees(struct btrfs_root *left_root,
+			struct btrfs_root *right_root,
+			btrfs_changed_cb_t changed_cb, void *ctx)
+{
+	struct btrfs_fs_info *fs_info = left_root->fs_info;
+	int ret;
+	int cmp;
+	struct btrfs_path *left_path = NULL;
+	struct btrfs_path *right_path = NULL;
+	struct btrfs_key left_key;
+	struct btrfs_key right_key;
+	char *tmp_buf = NULL;
+	int left_root_level;
+	int right_root_level;
+	int left_level;
+	int right_level;
+	int left_end_reached;
+	int right_end_reached;
+	int advance_left;
+	int advance_right;
+	u64 left_blockptr;
+	u64 right_blockptr;
+	u64 left_gen;
+	u64 right_gen;
+
+	left_path = btrfs_alloc_path();
+	if (!left_path) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	right_path = btrfs_alloc_path();
+	if (!right_path) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	tmp_buf = kvmalloc(fs_info->nodesize, GFP_KERNEL);
+	if (!tmp_buf) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	left_path->search_commit_root = 1;
+	left_path->skip_locking = 1;
+	right_path->search_commit_root = 1;
+	right_path->skip_locking = 1;
+
+	/*
+	 * Strategy: Go to the first items of both trees. Then do
+	 *
+	 * If both trees are at level 0
+	 *   Compare keys of current items
+	 *     If left < right treat left item as new, advance left tree
+	 *       and repeat
+	 *     If left > right treat right item as deleted, advance right tree
+	 *       and repeat
+	 *     If left == right do deep compare of items, treat as changed if
+	 *       needed, advance both trees and repeat
+	 * If both trees are at the same level but not at level 0
+	 *   Compare keys of current nodes/leafs
+	 *     If left < right advance left tree and repeat
+	 *     If left > right advance right tree and repeat
+	 *     If left == right compare blockptrs of the next nodes/leafs
+	 *       If they match advance both trees but stay at the same level
+	 *         and repeat
+	 *       If they don't match advance both trees while allowing to go
+	 *         deeper and repeat
+	 * If tree levels are different
+	 *   Advance the tree that needs it and repeat
+	 *
+	 * Advancing a tree means:
+	 *   If we are at level 0, try to go to the next slot. If that's not
+	 *   possible, go one level up and repeat. Stop when we found a level
+	 *   where we could go to the next slot. We may at this point be on a
+	 *   node or a leaf.
+	 *
+	 *   If we are not at level 0 and not on shared tree blocks, go one
+	 *   level deeper.
+	 *
+	 *   If we are not at level 0 and on shared tree blocks, go one slot to
+	 *   the right if possible or go up and right.
+	 */
+
+	down_read(&fs_info->commit_root_sem);
+	left_level = btrfs_header_level(left_root->commit_root);
+	left_root_level = left_level;
+	left_path->nodes[left_level] =
+			btrfs_clone_extent_buffer(left_root->commit_root);
+	if (!left_path->nodes[left_level]) {
+		up_read(&fs_info->commit_root_sem);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	right_level = btrfs_header_level(right_root->commit_root);
+	right_root_level = right_level;
+	right_path->nodes[right_level] =
+			btrfs_clone_extent_buffer(right_root->commit_root);
+	if (!right_path->nodes[right_level]) {
+		up_read(&fs_info->commit_root_sem);
+		ret = -ENOMEM;
+		goto out;
+	}
+	up_read(&fs_info->commit_root_sem);
+
+	if (left_level == 0)
+		btrfs_item_key_to_cpu(left_path->nodes[left_level],
+				&left_key, left_path->slots[left_level]);
+	else
+		btrfs_node_key_to_cpu(left_path->nodes[left_level],
+				&left_key, left_path->slots[left_level]);
+	if (right_level == 0)
+		btrfs_item_key_to_cpu(right_path->nodes[right_level],
+				&right_key, right_path->slots[right_level]);
+	else
+		btrfs_node_key_to_cpu(right_path->nodes[right_level],
+				&right_key, right_path->slots[right_level]);
+
+	left_end_reached = right_end_reached = 0;
+	advance_left = advance_right = 0;
+
+	while (1) {
+		cond_resched();
+		if (advance_left && !left_end_reached) {
+			ret = tree_advance(left_path, &left_level,
+					left_root_level,
+					advance_left != ADVANCE_ONLY_NEXT,
+					&left_key);
+			if (ret == -1)
+				left_end_reached = ADVANCE;
+			else if (ret < 0)
+				goto out;
+			advance_left = 0;
+		}
+		if (advance_right && !right_end_reached) {
+			ret = tree_advance(right_path, &right_level,
+					right_root_level,
+					advance_right != ADVANCE_ONLY_NEXT,
+					&right_key);
+			if (ret == -1)
+				right_end_reached = ADVANCE;
+			else if (ret < 0)
+				goto out;
+			advance_right = 0;
+		}
+
+		if (left_end_reached && right_end_reached) {
+			ret = 0;
+			goto out;
+		} else if (left_end_reached) {
+			if (right_level == 0) {
+				ret = changed_cb(left_path, right_path,
+						&right_key,
+						BTRFS_COMPARE_TREE_DELETED,
+						ctx);
+				if (ret < 0)
+					goto out;
+			}
+			advance_right = ADVANCE;
+			continue;
+		} else if (right_end_reached) {
+			if (left_level == 0) {
+				ret = changed_cb(left_path, right_path,
+						&left_key,
+						BTRFS_COMPARE_TREE_NEW,
+						ctx);
+				if (ret < 0)
+					goto out;
+			}
+			advance_left = ADVANCE;
+			continue;
+		}
+
+		if (left_level == 0 && right_level == 0) {
+			cmp = btrfs_comp_cpu_keys(&left_key, &right_key);
+			if (cmp < 0) {
+				ret = changed_cb(left_path, right_path,
+						&left_key,
+						BTRFS_COMPARE_TREE_NEW,
+						ctx);
+				if (ret < 0)
+					goto out;
+				advance_left = ADVANCE;
+			} else if (cmp > 0) {
+				ret = changed_cb(left_path, right_path,
+						&right_key,
+						BTRFS_COMPARE_TREE_DELETED,
+						ctx);
+				if (ret < 0)
+					goto out;
+				advance_right = ADVANCE;
+			} else {
+				enum btrfs_compare_tree_result result;
+
+				WARN_ON(!extent_buffer_uptodate(left_path->nodes[0]));
+				ret = tree_compare_item(left_path, right_path,
+							tmp_buf);
+				if (ret)
+					result = BTRFS_COMPARE_TREE_CHANGED;
+				else
+					result = BTRFS_COMPARE_TREE_SAME;
+				ret = changed_cb(left_path, right_path,
+						 &left_key, result, ctx);
+				if (ret < 0)
+					goto out;
+				advance_left = ADVANCE;
+				advance_right = ADVANCE;
+			}
+		} else if (left_level == right_level) {
+			cmp = btrfs_comp_cpu_keys(&left_key, &right_key);
+			if (cmp < 0) {
+				advance_left = ADVANCE;
+			} else if (cmp > 0) {
+				advance_right = ADVANCE;
+			} else {
+				left_blockptr = btrfs_node_blockptr(
+						left_path->nodes[left_level],
+						left_path->slots[left_level]);
+				right_blockptr = btrfs_node_blockptr(
+						right_path->nodes[right_level],
+						right_path->slots[right_level]);
+				left_gen = btrfs_node_ptr_generation(
+						left_path->nodes[left_level],
+						left_path->slots[left_level]);
+				right_gen = btrfs_node_ptr_generation(
+						right_path->nodes[right_level],
+						right_path->slots[right_level]);
+				if (left_blockptr == right_blockptr &&
+				    left_gen == right_gen) {
+					/*
+					 * As we're on a shared block, don't
+					 * allow to go deeper.
+					 */
+					advance_left = ADVANCE_ONLY_NEXT;
+					advance_right = ADVANCE_ONLY_NEXT;
+				} else {
+					advance_left = ADVANCE;
+					advance_right = ADVANCE;
+				}
+			}
+		} else if (left_level < right_level) {
+			advance_right = ADVANCE;
+		} else {
+			advance_left = ADVANCE;
+		}
+	}
+
+out:
+	btrfs_free_path(left_path);
+	btrfs_free_path(right_path);
+	kvfree(tmp_buf);
+	return ret;
+}
+
 static int send_subvol(struct send_ctx *sctx)
 {
 	int ret;
@@ -6583,6 +6967,38 @@
 	return btrfs_commit_transaction(trans);
 }
 
+/*
+ * Make sure any existing dellaloc is flushed for any root used by a send
+ * operation so that we do not miss any data and we do not race with writeback
+ * finishing and changing a tree while send is using the tree. This could
+ * happen if a subvolume is in RW mode, has delalloc, is turned to RO mode and
+ * a send operation then uses the subvolume.
+ * After flushing delalloc ensure_commit_roots_uptodate() must be called.
+ */
+static int flush_delalloc_roots(struct send_ctx *sctx)
+{
+	struct btrfs_root *root = sctx->parent_root;
+	int ret;
+	int i;
+
+	if (root) {
+		ret = btrfs_start_delalloc_snapshot(root);
+		if (ret)
+			return ret;
+		btrfs_wait_ordered_extents(root, U64_MAX, 0, U64_MAX);
+	}
+
+	for (i = 0; i < sctx->clone_roots_cnt; i++) {
+		root = sctx->clone_roots[i].root;
+		ret = btrfs_start_delalloc_snapshot(root);
+		if (ret)
+			return ret;
+		btrfs_wait_ordered_extents(root, U64_MAX, 0, U64_MAX);
+	}
+
+	return 0;
+}
+
 static void btrfs_root_dec_send_in_progress(struct btrfs_root* root)
 {
 	spin_lock(&root->root_item_lock);
@@ -6598,6 +7014,13 @@
 	spin_unlock(&root->root_item_lock);
 }
 
+static void dedupe_in_progress_warn(const struct btrfs_root *root)
+{
+	btrfs_warn_rl(root->fs_info,
+"cannot use root %llu for send while deduplications on it are in progress (%d in progress)",
+		      root->root_key.objectid, root->dedupe_in_progress);
+}
+
 long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg)
 {
 	int ret = 0;
@@ -6621,6 +7044,11 @@
 	 * making it RW. This also protects against deletion.
 	 */
 	spin_lock(&send_root->root_item_lock);
+	if (btrfs_root_readonly(send_root) && send_root->dedupe_in_progress) {
+		dedupe_in_progress_warn(send_root);
+		spin_unlock(&send_root->root_item_lock);
+		return -EAGAIN;
+	}
 	send_root->send_in_progress++;
 	spin_unlock(&send_root->root_item_lock);
 
@@ -6650,7 +7078,7 @@
 		goto out;
 	}
 
-	if (!access_ok(VERIFY_READ, arg->clone_sources,
+	if (!access_ok(arg->clone_sources,
 			sizeof(*arg->clone_sources) *
 			arg->clone_sources_count)) {
 		ret = -EFAULT;
@@ -6755,6 +7183,13 @@
 				ret = -EPERM;
 				goto out;
 			}
+			if (clone_root->dedupe_in_progress) {
+				dedupe_in_progress_warn(clone_root);
+				spin_unlock(&clone_root->root_item_lock);
+				srcu_read_unlock(&fs_info->subvol_srcu, index);
+				ret = -EAGAIN;
+				goto out;
+			}
 			clone_root->send_in_progress++;
 			spin_unlock(&clone_root->root_item_lock);
 			srcu_read_unlock(&fs_info->subvol_srcu, index);
@@ -6789,6 +7224,13 @@
 			ret = -EPERM;
 			goto out;
 		}
+		if (sctx->parent_root->dedupe_in_progress) {
+			dedupe_in_progress_warn(sctx->parent_root);
+			spin_unlock(&sctx->parent_root->root_item_lock);
+			srcu_read_unlock(&fs_info->subvol_srcu, index);
+			ret = -EAGAIN;
+			goto out;
+		}
 		spin_unlock(&sctx->parent_root->root_item_lock);
 
 		srcu_read_unlock(&fs_info->subvol_srcu, index);
@@ -6807,13 +7249,31 @@
 			NULL);
 	sort_clone_roots = 1;
 
+	ret = flush_delalloc_roots(sctx);
+	if (ret)
+		goto out;
+
 	ret = ensure_commit_roots_uptodate(sctx);
 	if (ret)
 		goto out;
 
+	mutex_lock(&fs_info->balance_mutex);
+	if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
+		mutex_unlock(&fs_info->balance_mutex);
+		btrfs_warn_rl(fs_info,
+		"cannot run send because a balance operation is in progress");
+		ret = -EAGAIN;
+		goto out;
+	}
+	fs_info->send_in_progress++;
+	mutex_unlock(&fs_info->balance_mutex);
+
 	current->journal_info = BTRFS_SEND_TRANS_STUB;
 	ret = send_subvol(sctx);
 	current->journal_info = NULL;
+	mutex_lock(&fs_info->balance_mutex);
+	fs_info->send_in_progress--;
+	mutex_unlock(&fs_info->balance_mutex);
 	if (ret < 0)
 		goto out;
 
diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c
new file mode 100644
index 0000000..e8a4b0e
--- /dev/null
+++ b/fs/btrfs/space-info.c
@@ -0,0 +1,1117 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "misc.h"
+#include "ctree.h"
+#include "space-info.h"
+#include "sysfs.h"
+#include "volumes.h"
+#include "free-space-cache.h"
+#include "ordered-data.h"
+#include "transaction.h"
+#include "block-group.h"
+
+u64 btrfs_space_info_used(struct btrfs_space_info *s_info,
+			  bool may_use_included)
+{
+	ASSERT(s_info);
+	return s_info->bytes_used + s_info->bytes_reserved +
+		s_info->bytes_pinned + s_info->bytes_readonly +
+		(may_use_included ? s_info->bytes_may_use : 0);
+}
+
+/*
+ * after adding space to the filesystem, we need to clear the full flags
+ * on all the space infos.
+ */
+void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
+{
+	struct list_head *head = &info->space_info;
+	struct btrfs_space_info *found;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(found, head, list)
+		found->full = 0;
+	rcu_read_unlock();
+}
+
+static int create_space_info(struct btrfs_fs_info *info, u64 flags)
+{
+
+	struct btrfs_space_info *space_info;
+	int i;
+	int ret;
+
+	space_info = kzalloc(sizeof(*space_info), GFP_NOFS);
+	if (!space_info)
+		return -ENOMEM;
+
+	ret = percpu_counter_init(&space_info->total_bytes_pinned, 0,
+				 GFP_KERNEL);
+	if (ret) {
+		kfree(space_info);
+		return ret;
+	}
+
+	for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)
+		INIT_LIST_HEAD(&space_info->block_groups[i]);
+	init_rwsem(&space_info->groups_sem);
+	spin_lock_init(&space_info->lock);
+	space_info->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;
+	space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
+	init_waitqueue_head(&space_info->wait);
+	INIT_LIST_HEAD(&space_info->ro_bgs);
+	INIT_LIST_HEAD(&space_info->tickets);
+	INIT_LIST_HEAD(&space_info->priority_tickets);
+
+	ret = btrfs_sysfs_add_space_info_type(info, space_info);
+	if (ret)
+		return ret;
+
+	list_add_rcu(&space_info->list, &info->space_info);
+	if (flags & BTRFS_BLOCK_GROUP_DATA)
+		info->data_sinfo = space_info;
+
+	return ret;
+}
+
+int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
+{
+	struct btrfs_super_block *disk_super;
+	u64 features;
+	u64 flags;
+	int mixed = 0;
+	int ret;
+
+	disk_super = fs_info->super_copy;
+	if (!btrfs_super_root(disk_super))
+		return -EINVAL;
+
+	features = btrfs_super_incompat_flags(disk_super);
+	if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
+		mixed = 1;
+
+	flags = BTRFS_BLOCK_GROUP_SYSTEM;
+	ret = create_space_info(fs_info, flags);
+	if (ret)
+		goto out;
+
+	if (mixed) {
+		flags = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA;
+		ret = create_space_info(fs_info, flags);
+	} else {
+		flags = BTRFS_BLOCK_GROUP_METADATA;
+		ret = create_space_info(fs_info, flags);
+		if (ret)
+			goto out;
+
+		flags = BTRFS_BLOCK_GROUP_DATA;
+		ret = create_space_info(fs_info, flags);
+	}
+out:
+	return ret;
+}
+
+void btrfs_update_space_info(struct btrfs_fs_info *info, u64 flags,
+			     u64 total_bytes, u64 bytes_used,
+			     u64 bytes_readonly,
+			     struct btrfs_space_info **space_info)
+{
+	struct btrfs_space_info *found;
+	int factor;
+
+	factor = btrfs_bg_type_to_factor(flags);
+
+	found = btrfs_find_space_info(info, flags);
+	ASSERT(found);
+	spin_lock(&found->lock);
+	found->total_bytes += total_bytes;
+	found->disk_total += total_bytes * factor;
+	found->bytes_used += bytes_used;
+	found->disk_used += bytes_used * factor;
+	found->bytes_readonly += bytes_readonly;
+	if (total_bytes > 0)
+		found->full = 0;
+	btrfs_try_granting_tickets(info, found);
+	spin_unlock(&found->lock);
+	*space_info = found;
+}
+
+struct btrfs_space_info *btrfs_find_space_info(struct btrfs_fs_info *info,
+					       u64 flags)
+{
+	struct list_head *head = &info->space_info;
+	struct btrfs_space_info *found;
+
+	flags &= BTRFS_BLOCK_GROUP_TYPE_MASK;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(found, head, list) {
+		if (found->flags & flags) {
+			rcu_read_unlock();
+			return found;
+		}
+	}
+	rcu_read_unlock();
+	return NULL;
+}
+
+static inline u64 calc_global_rsv_need_space(struct btrfs_block_rsv *global)
+{
+	return (global->size << 1);
+}
+
+static int can_overcommit(struct btrfs_fs_info *fs_info,
+			  struct btrfs_space_info *space_info, u64 bytes,
+			  enum btrfs_reserve_flush_enum flush,
+			  bool system_chunk)
+{
+	u64 profile;
+	u64 avail;
+	u64 used;
+	int factor;
+
+	/* Don't overcommit when in mixed mode. */
+	if (space_info->flags & BTRFS_BLOCK_GROUP_DATA)
+		return 0;
+
+	if (system_chunk)
+		profile = btrfs_system_alloc_profile(fs_info);
+	else
+		profile = btrfs_metadata_alloc_profile(fs_info);
+
+	used = btrfs_space_info_used(space_info, true);
+	avail = atomic64_read(&fs_info->free_chunk_space);
+
+	/*
+	 * If we have dup, raid1 or raid10 then only half of the free
+	 * space is actually usable.  For raid56, the space info used
+	 * doesn't include the parity drive, so we don't have to
+	 * change the math
+	 */
+	factor = btrfs_bg_type_to_factor(profile);
+	avail = div_u64(avail, factor);
+
+	/*
+	 * If we aren't flushing all things, let us overcommit up to
+	 * 1/2th of the space. If we can flush, don't let us overcommit
+	 * too much, let it overcommit up to 1/8 of the space.
+	 */
+	if (flush == BTRFS_RESERVE_FLUSH_ALL)
+		avail >>= 3;
+	else
+		avail >>= 1;
+
+	if (used + bytes < space_info->total_bytes + avail)
+		return 1;
+	return 0;
+}
+
+/*
+ * This is for space we already have accounted in space_info->bytes_may_use, so
+ * basically when we're returning space from block_rsv's.
+ */
+void btrfs_try_granting_tickets(struct btrfs_fs_info *fs_info,
+				struct btrfs_space_info *space_info)
+{
+	struct list_head *head;
+	enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_NO_FLUSH;
+
+	lockdep_assert_held(&space_info->lock);
+
+	head = &space_info->priority_tickets;
+again:
+	while (!list_empty(head)) {
+		struct reserve_ticket *ticket;
+		u64 used = btrfs_space_info_used(space_info, true);
+
+		ticket = list_first_entry(head, struct reserve_ticket, list);
+
+		/* Check and see if our ticket can be satisified now. */
+		if ((used + ticket->bytes <= space_info->total_bytes) ||
+		    can_overcommit(fs_info, space_info, ticket->bytes, flush,
+				   false)) {
+			btrfs_space_info_update_bytes_may_use(fs_info,
+							      space_info,
+							      ticket->bytes);
+			list_del_init(&ticket->list);
+			ticket->bytes = 0;
+			space_info->tickets_id++;
+			wake_up(&ticket->wait);
+		} else {
+			break;
+		}
+	}
+
+	if (head == &space_info->priority_tickets) {
+		head = &space_info->tickets;
+		flush = BTRFS_RESERVE_FLUSH_ALL;
+		goto again;
+	}
+}
+
+#define DUMP_BLOCK_RSV(fs_info, rsv_name)				\
+do {									\
+	struct btrfs_block_rsv *__rsv = &(fs_info)->rsv_name;		\
+	spin_lock(&__rsv->lock);					\
+	btrfs_info(fs_info, #rsv_name ": size %llu reserved %llu",	\
+		   __rsv->size, __rsv->reserved);			\
+	spin_unlock(&__rsv->lock);					\
+} while (0)
+
+static void __btrfs_dump_space_info(struct btrfs_fs_info *fs_info,
+				    struct btrfs_space_info *info)
+{
+	lockdep_assert_held(&info->lock);
+
+	btrfs_info(fs_info, "space_info %llu has %llu free, is %sfull",
+		   info->flags,
+		   info->total_bytes - btrfs_space_info_used(info, true),
+		   info->full ? "" : "not ");
+	btrfs_info(fs_info,
+		"space_info total=%llu, used=%llu, pinned=%llu, reserved=%llu, may_use=%llu, readonly=%llu",
+		info->total_bytes, info->bytes_used, info->bytes_pinned,
+		info->bytes_reserved, info->bytes_may_use,
+		info->bytes_readonly);
+
+	DUMP_BLOCK_RSV(fs_info, global_block_rsv);
+	DUMP_BLOCK_RSV(fs_info, trans_block_rsv);
+	DUMP_BLOCK_RSV(fs_info, chunk_block_rsv);
+	DUMP_BLOCK_RSV(fs_info, delayed_block_rsv);
+	DUMP_BLOCK_RSV(fs_info, delayed_refs_rsv);
+
+}
+
+void btrfs_dump_space_info(struct btrfs_fs_info *fs_info,
+			   struct btrfs_space_info *info, u64 bytes,
+			   int dump_block_groups)
+{
+	struct btrfs_block_group_cache *cache;
+	int index = 0;
+
+	spin_lock(&info->lock);
+	__btrfs_dump_space_info(fs_info, info);
+	spin_unlock(&info->lock);
+
+	if (!dump_block_groups)
+		return;
+
+	down_read(&info->groups_sem);
+again:
+	list_for_each_entry(cache, &info->block_groups[index], list) {
+		spin_lock(&cache->lock);
+		btrfs_info(fs_info,
+			"block group %llu has %llu bytes, %llu used %llu pinned %llu reserved %s",
+			cache->key.objectid, cache->key.offset,
+			btrfs_block_group_used(&cache->item), cache->pinned,
+			cache->reserved, cache->ro ? "[readonly]" : "");
+		btrfs_dump_free_space(cache, bytes);
+		spin_unlock(&cache->lock);
+	}
+	if (++index < BTRFS_NR_RAID_TYPES)
+		goto again;
+	up_read(&info->groups_sem);
+}
+
+static void btrfs_writeback_inodes_sb_nr(struct btrfs_fs_info *fs_info,
+					 unsigned long nr_pages, int nr_items)
+{
+	struct super_block *sb = fs_info->sb;
+
+	if (down_read_trylock(&sb->s_umount)) {
+		writeback_inodes_sb_nr(sb, nr_pages, WB_REASON_FS_FREE_SPACE);
+		up_read(&sb->s_umount);
+	} else {
+		/*
+		 * We needn't worry the filesystem going from r/w to r/o though
+		 * we don't acquire ->s_umount mutex, because the filesystem
+		 * should guarantee the delalloc inodes list be empty after
+		 * the filesystem is readonly(all dirty pages are written to
+		 * the disk).
+		 */
+		btrfs_start_delalloc_roots(fs_info, nr_items);
+		if (!current->journal_info)
+			btrfs_wait_ordered_roots(fs_info, nr_items, 0, (u64)-1);
+	}
+}
+
+static inline u64 calc_reclaim_items_nr(struct btrfs_fs_info *fs_info,
+					u64 to_reclaim)
+{
+	u64 bytes;
+	u64 nr;
+
+	bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
+	nr = div64_u64(to_reclaim, bytes);
+	if (!nr)
+		nr = 1;
+	return nr;
+}
+
+#define EXTENT_SIZE_PER_ITEM	SZ_256K
+
+/*
+ * shrink metadata reservation for delalloc
+ */
+static void shrink_delalloc(struct btrfs_fs_info *fs_info, u64 to_reclaim,
+			    u64 orig, bool wait_ordered)
+{
+	struct btrfs_space_info *space_info;
+	struct btrfs_trans_handle *trans;
+	u64 delalloc_bytes;
+	u64 dio_bytes;
+	u64 async_pages;
+	u64 items;
+	long time_left;
+	unsigned long nr_pages;
+	int loops;
+
+	/* Calc the number of the pages we need flush for space reservation */
+	items = calc_reclaim_items_nr(fs_info, to_reclaim);
+	to_reclaim = items * EXTENT_SIZE_PER_ITEM;
+
+	trans = (struct btrfs_trans_handle *)current->journal_info;
+	space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
+
+	delalloc_bytes = percpu_counter_sum_positive(
+						&fs_info->delalloc_bytes);
+	dio_bytes = percpu_counter_sum_positive(&fs_info->dio_bytes);
+	if (delalloc_bytes == 0 && dio_bytes == 0) {
+		if (trans)
+			return;
+		if (wait_ordered)
+			btrfs_wait_ordered_roots(fs_info, items, 0, (u64)-1);
+		return;
+	}
+
+	/*
+	 * If we are doing more ordered than delalloc we need to just wait on
+	 * ordered extents, otherwise we'll waste time trying to flush delalloc
+	 * that likely won't give us the space back we need.
+	 */
+	if (dio_bytes > delalloc_bytes)
+		wait_ordered = true;
+
+	loops = 0;
+	while ((delalloc_bytes || dio_bytes) && loops < 3) {
+		nr_pages = min(delalloc_bytes, to_reclaim) >> PAGE_SHIFT;
+
+		/*
+		 * Triggers inode writeback for up to nr_pages. This will invoke
+		 * ->writepages callback and trigger delalloc filling
+		 *  (btrfs_run_delalloc_range()).
+		 */
+		btrfs_writeback_inodes_sb_nr(fs_info, nr_pages, items);
+
+		/*
+		 * We need to wait for the compressed pages to start before
+		 * we continue.
+		 */
+		async_pages = atomic_read(&fs_info->async_delalloc_pages);
+		if (!async_pages)
+			goto skip_async;
+
+		/*
+		 * Calculate how many compressed pages we want to be written
+		 * before we continue. I.e if there are more async pages than we
+		 * require wait_event will wait until nr_pages are written.
+		 */
+		if (async_pages <= nr_pages)
+			async_pages = 0;
+		else
+			async_pages -= nr_pages;
+
+		wait_event(fs_info->async_submit_wait,
+			   atomic_read(&fs_info->async_delalloc_pages) <=
+			   (int)async_pages);
+skip_async:
+		spin_lock(&space_info->lock);
+		if (list_empty(&space_info->tickets) &&
+		    list_empty(&space_info->priority_tickets)) {
+			spin_unlock(&space_info->lock);
+			break;
+		}
+		spin_unlock(&space_info->lock);
+
+		loops++;
+		if (wait_ordered && !trans) {
+			btrfs_wait_ordered_roots(fs_info, items, 0, (u64)-1);
+		} else {
+			time_left = schedule_timeout_killable(1);
+			if (time_left)
+				break;
+		}
+		delalloc_bytes = percpu_counter_sum_positive(
+						&fs_info->delalloc_bytes);
+		dio_bytes = percpu_counter_sum_positive(&fs_info->dio_bytes);
+	}
+}
+
+/**
+ * maybe_commit_transaction - possibly commit the transaction if its ok to
+ * @root - the root we're allocating for
+ * @bytes - the number of bytes we want to reserve
+ * @force - force the commit
+ *
+ * This will check to make sure that committing the transaction will actually
+ * get us somewhere and then commit the transaction if it does.  Otherwise it
+ * will return -ENOSPC.
+ */
+static int may_commit_transaction(struct btrfs_fs_info *fs_info,
+				  struct btrfs_space_info *space_info)
+{
+	struct reserve_ticket *ticket = NULL;
+	struct btrfs_block_rsv *delayed_rsv = &fs_info->delayed_block_rsv;
+	struct btrfs_block_rsv *delayed_refs_rsv = &fs_info->delayed_refs_rsv;
+	struct btrfs_trans_handle *trans;
+	u64 bytes_needed;
+	u64 reclaim_bytes = 0;
+	u64 cur_free_bytes = 0;
+
+	trans = (struct btrfs_trans_handle *)current->journal_info;
+	if (trans)
+		return -EAGAIN;
+
+	spin_lock(&space_info->lock);
+	cur_free_bytes = btrfs_space_info_used(space_info, true);
+	if (cur_free_bytes < space_info->total_bytes)
+		cur_free_bytes = space_info->total_bytes - cur_free_bytes;
+	else
+		cur_free_bytes = 0;
+
+	if (!list_empty(&space_info->priority_tickets))
+		ticket = list_first_entry(&space_info->priority_tickets,
+					  struct reserve_ticket, list);
+	else if (!list_empty(&space_info->tickets))
+		ticket = list_first_entry(&space_info->tickets,
+					  struct reserve_ticket, list);
+	bytes_needed = (ticket) ? ticket->bytes : 0;
+
+	if (bytes_needed > cur_free_bytes)
+		bytes_needed -= cur_free_bytes;
+	else
+		bytes_needed = 0;
+	spin_unlock(&space_info->lock);
+
+	if (!bytes_needed)
+		return 0;
+
+	trans = btrfs_join_transaction(fs_info->extent_root);
+	if (IS_ERR(trans))
+		return PTR_ERR(trans);
+
+	/*
+	 * See if there is enough pinned space to make this reservation, or if
+	 * we have block groups that are going to be freed, allowing us to
+	 * possibly do a chunk allocation the next loop through.
+	 */
+	if (test_bit(BTRFS_TRANS_HAVE_FREE_BGS, &trans->transaction->flags) ||
+	    __percpu_counter_compare(&space_info->total_bytes_pinned,
+				     bytes_needed,
+				     BTRFS_TOTAL_BYTES_PINNED_BATCH) >= 0)
+		goto commit;
+
+	/*
+	 * See if there is some space in the delayed insertion reservation for
+	 * this reservation.
+	 */
+	if (space_info != delayed_rsv->space_info)
+		goto enospc;
+
+	spin_lock(&delayed_rsv->lock);
+	reclaim_bytes += delayed_rsv->reserved;
+	spin_unlock(&delayed_rsv->lock);
+
+	spin_lock(&delayed_refs_rsv->lock);
+	reclaim_bytes += delayed_refs_rsv->reserved;
+	spin_unlock(&delayed_refs_rsv->lock);
+	if (reclaim_bytes >= bytes_needed)
+		goto commit;
+	bytes_needed -= reclaim_bytes;
+
+	if (__percpu_counter_compare(&space_info->total_bytes_pinned,
+				   bytes_needed,
+				   BTRFS_TOTAL_BYTES_PINNED_BATCH) < 0)
+		goto enospc;
+
+commit:
+	return btrfs_commit_transaction(trans);
+enospc:
+	btrfs_end_transaction(trans);
+	return -ENOSPC;
+}
+
+/*
+ * Try to flush some data based on policy set by @state. This is only advisory
+ * and may fail for various reasons. The caller is supposed to examine the
+ * state of @space_info to detect the outcome.
+ */
+static void flush_space(struct btrfs_fs_info *fs_info,
+		       struct btrfs_space_info *space_info, u64 num_bytes,
+		       int state)
+{
+	struct btrfs_root *root = fs_info->extent_root;
+	struct btrfs_trans_handle *trans;
+	int nr;
+	int ret = 0;
+
+	switch (state) {
+	case FLUSH_DELAYED_ITEMS_NR:
+	case FLUSH_DELAYED_ITEMS:
+		if (state == FLUSH_DELAYED_ITEMS_NR)
+			nr = calc_reclaim_items_nr(fs_info, num_bytes) * 2;
+		else
+			nr = -1;
+
+		trans = btrfs_join_transaction(root);
+		if (IS_ERR(trans)) {
+			ret = PTR_ERR(trans);
+			break;
+		}
+		ret = btrfs_run_delayed_items_nr(trans, nr);
+		btrfs_end_transaction(trans);
+		break;
+	case FLUSH_DELALLOC:
+	case FLUSH_DELALLOC_WAIT:
+		shrink_delalloc(fs_info, num_bytes * 2, num_bytes,
+				state == FLUSH_DELALLOC_WAIT);
+		break;
+	case FLUSH_DELAYED_REFS_NR:
+	case FLUSH_DELAYED_REFS:
+		trans = btrfs_join_transaction(root);
+		if (IS_ERR(trans)) {
+			ret = PTR_ERR(trans);
+			break;
+		}
+		if (state == FLUSH_DELAYED_REFS_NR)
+			nr = calc_reclaim_items_nr(fs_info, num_bytes);
+		else
+			nr = 0;
+		btrfs_run_delayed_refs(trans, nr);
+		btrfs_end_transaction(trans);
+		break;
+	case ALLOC_CHUNK:
+	case ALLOC_CHUNK_FORCE:
+		trans = btrfs_join_transaction(root);
+		if (IS_ERR(trans)) {
+			ret = PTR_ERR(trans);
+			break;
+		}
+		ret = btrfs_chunk_alloc(trans,
+				btrfs_metadata_alloc_profile(fs_info),
+				(state == ALLOC_CHUNK) ? CHUNK_ALLOC_NO_FORCE :
+					CHUNK_ALLOC_FORCE);
+		btrfs_end_transaction(trans);
+		if (ret > 0 || ret == -ENOSPC)
+			ret = 0;
+		break;
+	case RUN_DELAYED_IPUTS:
+		/*
+		 * If we have pending delayed iputs then we could free up a
+		 * bunch of pinned space, so make sure we run the iputs before
+		 * we do our pinned bytes check below.
+		 */
+		btrfs_run_delayed_iputs(fs_info);
+		btrfs_wait_on_delayed_iputs(fs_info);
+		break;
+	case COMMIT_TRANS:
+		ret = may_commit_transaction(fs_info, space_info);
+		break;
+	default:
+		ret = -ENOSPC;
+		break;
+	}
+
+	trace_btrfs_flush_space(fs_info, space_info->flags, num_bytes, state,
+				ret);
+	return;
+}
+
+static inline u64
+btrfs_calc_reclaim_metadata_size(struct btrfs_fs_info *fs_info,
+				 struct btrfs_space_info *space_info,
+				 bool system_chunk)
+{
+	struct reserve_ticket *ticket;
+	u64 used;
+	u64 expected;
+	u64 to_reclaim = 0;
+
+	list_for_each_entry(ticket, &space_info->tickets, list)
+		to_reclaim += ticket->bytes;
+	list_for_each_entry(ticket, &space_info->priority_tickets, list)
+		to_reclaim += ticket->bytes;
+	if (to_reclaim)
+		return to_reclaim;
+
+	to_reclaim = min_t(u64, num_online_cpus() * SZ_1M, SZ_16M);
+	if (can_overcommit(fs_info, space_info, to_reclaim,
+			   BTRFS_RESERVE_FLUSH_ALL, system_chunk))
+		return 0;
+
+	used = btrfs_space_info_used(space_info, true);
+
+	if (can_overcommit(fs_info, space_info, SZ_1M,
+			   BTRFS_RESERVE_FLUSH_ALL, system_chunk))
+		expected = div_factor_fine(space_info->total_bytes, 95);
+	else
+		expected = div_factor_fine(space_info->total_bytes, 90);
+
+	if (used > expected)
+		to_reclaim = used - expected;
+	else
+		to_reclaim = 0;
+	to_reclaim = min(to_reclaim, space_info->bytes_may_use +
+				     space_info->bytes_reserved);
+	return to_reclaim;
+}
+
+static inline int need_do_async_reclaim(struct btrfs_fs_info *fs_info,
+					struct btrfs_space_info *space_info,
+					u64 used, bool system_chunk)
+{
+	u64 thresh = div_factor_fine(space_info->total_bytes, 98);
+
+	/* If we're just plain full then async reclaim just slows us down. */
+	if ((space_info->bytes_used + space_info->bytes_reserved) >= thresh)
+		return 0;
+
+	if (!btrfs_calc_reclaim_metadata_size(fs_info, space_info,
+					      system_chunk))
+		return 0;
+
+	return (used >= thresh && !btrfs_fs_closing(fs_info) &&
+		!test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state));
+}
+
+/*
+ * maybe_fail_all_tickets - we've exhausted our flushing, start failing tickets
+ * @fs_info - fs_info for this fs
+ * @space_info - the space info we were flushing
+ *
+ * We call this when we've exhausted our flushing ability and haven't made
+ * progress in satisfying tickets.  The reservation code handles tickets in
+ * order, so if there is a large ticket first and then smaller ones we could
+ * very well satisfy the smaller tickets.  This will attempt to wake up any
+ * tickets in the list to catch this case.
+ *
+ * This function returns true if it was able to make progress by clearing out
+ * other tickets, or if it stumbles across a ticket that was smaller than the
+ * first ticket.
+ */
+static bool maybe_fail_all_tickets(struct btrfs_fs_info *fs_info,
+				   struct btrfs_space_info *space_info)
+{
+	struct reserve_ticket *ticket;
+	u64 tickets_id = space_info->tickets_id;
+	u64 first_ticket_bytes = 0;
+
+	if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
+		btrfs_info(fs_info, "cannot satisfy tickets, dumping space info");
+		__btrfs_dump_space_info(fs_info, space_info);
+	}
+
+	while (!list_empty(&space_info->tickets) &&
+	       tickets_id == space_info->tickets_id) {
+		ticket = list_first_entry(&space_info->tickets,
+					  struct reserve_ticket, list);
+
+		/*
+		 * may_commit_transaction will avoid committing the transaction
+		 * if it doesn't feel like the space reclaimed by the commit
+		 * would result in the ticket succeeding.  However if we have a
+		 * smaller ticket in the queue it may be small enough to be
+		 * satisified by committing the transaction, so if any
+		 * subsequent ticket is smaller than the first ticket go ahead
+		 * and send us back for another loop through the enospc flushing
+		 * code.
+		 */
+		if (first_ticket_bytes == 0)
+			first_ticket_bytes = ticket->bytes;
+		else if (first_ticket_bytes > ticket->bytes)
+			return true;
+
+		if (btrfs_test_opt(fs_info, ENOSPC_DEBUG))
+			btrfs_info(fs_info, "failing ticket with %llu bytes",
+				   ticket->bytes);
+
+		list_del_init(&ticket->list);
+		ticket->error = -ENOSPC;
+		wake_up(&ticket->wait);
+
+		/*
+		 * We're just throwing tickets away, so more flushing may not
+		 * trip over btrfs_try_granting_tickets, so we need to call it
+		 * here to see if we can make progress with the next ticket in
+		 * the list.
+		 */
+		btrfs_try_granting_tickets(fs_info, space_info);
+	}
+	return (tickets_id != space_info->tickets_id);
+}
+
+/*
+ * This is for normal flushers, we can wait all goddamned day if we want to.  We
+ * will loop and continuously try to flush as long as we are making progress.
+ * We count progress as clearing off tickets each time we have to loop.
+ */
+static void btrfs_async_reclaim_metadata_space(struct work_struct *work)
+{
+	struct btrfs_fs_info *fs_info;
+	struct btrfs_space_info *space_info;
+	u64 to_reclaim;
+	int flush_state;
+	int commit_cycles = 0;
+	u64 last_tickets_id;
+
+	fs_info = container_of(work, struct btrfs_fs_info, async_reclaim_work);
+	space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
+
+	spin_lock(&space_info->lock);
+	to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, space_info,
+						      false);
+	if (!to_reclaim) {
+		space_info->flush = 0;
+		spin_unlock(&space_info->lock);
+		return;
+	}
+	last_tickets_id = space_info->tickets_id;
+	spin_unlock(&space_info->lock);
+
+	flush_state = FLUSH_DELAYED_ITEMS_NR;
+	do {
+		flush_space(fs_info, space_info, to_reclaim, flush_state);
+		spin_lock(&space_info->lock);
+		if (list_empty(&space_info->tickets)) {
+			space_info->flush = 0;
+			spin_unlock(&space_info->lock);
+			return;
+		}
+		to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info,
+							      space_info,
+							      false);
+		if (last_tickets_id == space_info->tickets_id) {
+			flush_state++;
+		} else {
+			last_tickets_id = space_info->tickets_id;
+			flush_state = FLUSH_DELAYED_ITEMS_NR;
+			if (commit_cycles)
+				commit_cycles--;
+		}
+
+		/*
+		 * We don't want to force a chunk allocation until we've tried
+		 * pretty hard to reclaim space.  Think of the case where we
+		 * freed up a bunch of space and so have a lot of pinned space
+		 * to reclaim.  We would rather use that than possibly create a
+		 * underutilized metadata chunk.  So if this is our first run
+		 * through the flushing state machine skip ALLOC_CHUNK_FORCE and
+		 * commit the transaction.  If nothing has changed the next go
+		 * around then we can force a chunk allocation.
+		 */
+		if (flush_state == ALLOC_CHUNK_FORCE && !commit_cycles)
+			flush_state++;
+
+		if (flush_state > COMMIT_TRANS) {
+			commit_cycles++;
+			if (commit_cycles > 2) {
+				if (maybe_fail_all_tickets(fs_info, space_info)) {
+					flush_state = FLUSH_DELAYED_ITEMS_NR;
+					commit_cycles--;
+				} else {
+					space_info->flush = 0;
+				}
+			} else {
+				flush_state = FLUSH_DELAYED_ITEMS_NR;
+			}
+		}
+		spin_unlock(&space_info->lock);
+	} while (flush_state <= COMMIT_TRANS);
+}
+
+void btrfs_init_async_reclaim_work(struct work_struct *work)
+{
+	INIT_WORK(work, btrfs_async_reclaim_metadata_space);
+}
+
+static const enum btrfs_flush_state priority_flush_states[] = {
+	FLUSH_DELAYED_ITEMS_NR,
+	FLUSH_DELAYED_ITEMS,
+	ALLOC_CHUNK,
+};
+
+static const enum btrfs_flush_state evict_flush_states[] = {
+	FLUSH_DELAYED_ITEMS_NR,
+	FLUSH_DELAYED_ITEMS,
+	FLUSH_DELAYED_REFS_NR,
+	FLUSH_DELAYED_REFS,
+	FLUSH_DELALLOC,
+	FLUSH_DELALLOC_WAIT,
+	ALLOC_CHUNK,
+	COMMIT_TRANS,
+};
+
+static void priority_reclaim_metadata_space(struct btrfs_fs_info *fs_info,
+				struct btrfs_space_info *space_info,
+				struct reserve_ticket *ticket,
+				const enum btrfs_flush_state *states,
+				int states_nr)
+{
+	u64 to_reclaim;
+	int flush_state;
+
+	spin_lock(&space_info->lock);
+	to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, space_info,
+						      false);
+	if (!to_reclaim) {
+		spin_unlock(&space_info->lock);
+		return;
+	}
+	spin_unlock(&space_info->lock);
+
+	flush_state = 0;
+	do {
+		flush_space(fs_info, space_info, to_reclaim, states[flush_state]);
+		flush_state++;
+		spin_lock(&space_info->lock);
+		if (ticket->bytes == 0) {
+			spin_unlock(&space_info->lock);
+			return;
+		}
+		spin_unlock(&space_info->lock);
+	} while (flush_state < states_nr);
+}
+
+static void wait_reserve_ticket(struct btrfs_fs_info *fs_info,
+				struct btrfs_space_info *space_info,
+				struct reserve_ticket *ticket)
+
+{
+	DEFINE_WAIT(wait);
+	int ret = 0;
+
+	spin_lock(&space_info->lock);
+	while (ticket->bytes > 0 && ticket->error == 0) {
+		ret = prepare_to_wait_event(&ticket->wait, &wait, TASK_KILLABLE);
+		if (ret) {
+			/*
+			 * Delete us from the list. After we unlock the space
+			 * info, we don't want the async reclaim job to reserve
+			 * space for this ticket. If that would happen, then the
+			 * ticket's task would not known that space was reserved
+			 * despite getting an error, resulting in a space leak
+			 * (bytes_may_use counter of our space_info).
+			 */
+			list_del_init(&ticket->list);
+			ticket->error = -EINTR;
+			break;
+		}
+		spin_unlock(&space_info->lock);
+
+		schedule();
+
+		finish_wait(&ticket->wait, &wait);
+		spin_lock(&space_info->lock);
+	}
+	spin_unlock(&space_info->lock);
+}
+
+/**
+ * handle_reserve_ticket - do the appropriate flushing and waiting for a ticket
+ * @fs_info - the fs
+ * @space_info - the space_info for the reservation
+ * @ticket - the ticket for the reservation
+ * @flush - how much we can flush
+ *
+ * This does the work of figuring out how to flush for the ticket, waiting for
+ * the reservation, and returning the appropriate error if there is one.
+ */
+static int handle_reserve_ticket(struct btrfs_fs_info *fs_info,
+				 struct btrfs_space_info *space_info,
+				 struct reserve_ticket *ticket,
+				 enum btrfs_reserve_flush_enum flush)
+{
+	int ret;
+
+	switch (flush) {
+	case BTRFS_RESERVE_FLUSH_ALL:
+		wait_reserve_ticket(fs_info, space_info, ticket);
+		break;
+	case BTRFS_RESERVE_FLUSH_LIMIT:
+		priority_reclaim_metadata_space(fs_info, space_info, ticket,
+						priority_flush_states,
+						ARRAY_SIZE(priority_flush_states));
+		break;
+	case BTRFS_RESERVE_FLUSH_EVICT:
+		priority_reclaim_metadata_space(fs_info, space_info, ticket,
+						evict_flush_states,
+						ARRAY_SIZE(evict_flush_states));
+		break;
+	default:
+		ASSERT(0);
+		break;
+	}
+
+	spin_lock(&space_info->lock);
+	ret = ticket->error;
+	if (ticket->bytes || ticket->error) {
+		/*
+		 * Need to delete here for priority tickets. For regular tickets
+		 * either the async reclaim job deletes the ticket from the list
+		 * or we delete it ourselves at wait_reserve_ticket().
+		 */
+		list_del_init(&ticket->list);
+		if (!ret)
+			ret = -ENOSPC;
+	}
+	spin_unlock(&space_info->lock);
+	ASSERT(list_empty(&ticket->list));
+	/*
+	 * Check that we can't have an error set if the reservation succeeded,
+	 * as that would confuse tasks and lead them to error out without
+	 * releasing reserved space (if an error happens the expectation is that
+	 * space wasn't reserved at all).
+	 */
+	ASSERT(!(ticket->bytes == 0 && ticket->error));
+	return ret;
+}
+
+/**
+ * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space
+ * @root - the root we're allocating for
+ * @space_info - the space info we want to allocate from
+ * @orig_bytes - the number of bytes we want
+ * @flush - whether or not we can flush to make our reservation
+ *
+ * This will reserve orig_bytes number of bytes from the space info associated
+ * with the block_rsv.  If there is not enough space it will make an attempt to
+ * flush out space to make room.  It will do this by flushing delalloc if
+ * possible or committing the transaction.  If flush is 0 then no attempts to
+ * regain reservations will be made and this will fail if there is not enough
+ * space already.
+ */
+static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info,
+				    struct btrfs_space_info *space_info,
+				    u64 orig_bytes,
+				    enum btrfs_reserve_flush_enum flush,
+				    bool system_chunk)
+{
+	struct reserve_ticket ticket;
+	u64 used;
+	int ret = 0;
+	bool pending_tickets;
+
+	ASSERT(orig_bytes);
+	ASSERT(!current->journal_info || flush != BTRFS_RESERVE_FLUSH_ALL);
+
+	spin_lock(&space_info->lock);
+	ret = -ENOSPC;
+	used = btrfs_space_info_used(space_info, true);
+	pending_tickets = !list_empty(&space_info->tickets) ||
+		!list_empty(&space_info->priority_tickets);
+
+	/*
+	 * Carry on if we have enough space (short-circuit) OR call
+	 * can_overcommit() to ensure we can overcommit to continue.
+	 */
+	if (!pending_tickets &&
+	    ((used + orig_bytes <= space_info->total_bytes) ||
+	     can_overcommit(fs_info, space_info, orig_bytes, flush,
+			   system_chunk))) {
+		btrfs_space_info_update_bytes_may_use(fs_info, space_info,
+						      orig_bytes);
+		ret = 0;
+	}
+
+	/*
+	 * If we couldn't make a reservation then setup our reservation ticket
+	 * and kick the async worker if it's not already running.
+	 *
+	 * If we are a priority flusher then we just need to add our ticket to
+	 * the list and we will do our own flushing further down.
+	 */
+	if (ret && flush != BTRFS_RESERVE_NO_FLUSH) {
+		ticket.bytes = orig_bytes;
+		ticket.error = 0;
+		init_waitqueue_head(&ticket.wait);
+		if (flush == BTRFS_RESERVE_FLUSH_ALL) {
+			list_add_tail(&ticket.list, &space_info->tickets);
+			if (!space_info->flush) {
+				space_info->flush = 1;
+				trace_btrfs_trigger_flush(fs_info,
+							  space_info->flags,
+							  orig_bytes, flush,
+							  "enospc");
+				queue_work(system_unbound_wq,
+					   &fs_info->async_reclaim_work);
+			}
+		} else {
+			list_add_tail(&ticket.list,
+				      &space_info->priority_tickets);
+		}
+	} else if (!ret && space_info->flags & BTRFS_BLOCK_GROUP_METADATA) {
+		used += orig_bytes;
+		/*
+		 * We will do the space reservation dance during log replay,
+		 * which means we won't have fs_info->fs_root set, so don't do
+		 * the async reclaim as we will panic.
+		 */
+		if (!test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags) &&
+		    need_do_async_reclaim(fs_info, space_info,
+					  used, system_chunk) &&
+		    !work_busy(&fs_info->async_reclaim_work)) {
+			trace_btrfs_trigger_flush(fs_info, space_info->flags,
+						  orig_bytes, flush, "preempt");
+			queue_work(system_unbound_wq,
+				   &fs_info->async_reclaim_work);
+		}
+	}
+	spin_unlock(&space_info->lock);
+	if (!ret || flush == BTRFS_RESERVE_NO_FLUSH)
+		return ret;
+
+	return handle_reserve_ticket(fs_info, space_info, &ticket, flush);
+}
+
+/**
+ * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space
+ * @root - the root we're allocating for
+ * @block_rsv - the block_rsv we're allocating for
+ * @orig_bytes - the number of bytes we want
+ * @flush - whether or not we can flush to make our reservation
+ *
+ * This will reserve orig_bytes number of bytes from the space info associated
+ * with the block_rsv.  If there is not enough space it will make an attempt to
+ * flush out space to make room.  It will do this by flushing delalloc if
+ * possible or committing the transaction.  If flush is 0 then no attempts to
+ * regain reservations will be made and this will fail if there is not enough
+ * space already.
+ */
+int btrfs_reserve_metadata_bytes(struct btrfs_root *root,
+				 struct btrfs_block_rsv *block_rsv,
+				 u64 orig_bytes,
+				 enum btrfs_reserve_flush_enum flush)
+{
+	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
+	int ret;
+	bool system_chunk = (root == fs_info->chunk_root);
+
+	ret = __reserve_metadata_bytes(fs_info, block_rsv->space_info,
+				       orig_bytes, flush, system_chunk);
+	if (ret == -ENOSPC &&
+	    unlikely(root->orphan_cleanup_state == ORPHAN_CLEANUP_STARTED)) {
+		if (block_rsv != global_rsv &&
+		    !btrfs_block_rsv_use_bytes(global_rsv, orig_bytes))
+			ret = 0;
+	}
+	if (ret == -ENOSPC) {
+		trace_btrfs_space_reservation(fs_info, "space_info:enospc",
+					      block_rsv->space_info->flags,
+					      orig_bytes, 1);
+
+		if (btrfs_test_opt(fs_info, ENOSPC_DEBUG))
+			btrfs_dump_space_info(fs_info, block_rsv->space_info,
+					      orig_bytes, 0);
+	}
+	return ret;
+}
diff --git a/fs/btrfs/space-info.h b/fs/btrfs/space-info.h
new file mode 100644
index 0000000..8867e84
--- /dev/null
+++ b/fs/btrfs/space-info.h
@@ -0,0 +1,143 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef BTRFS_SPACE_INFO_H
+#define BTRFS_SPACE_INFO_H
+
+struct btrfs_space_info {
+	spinlock_t lock;
+
+	u64 total_bytes;	/* total bytes in the space,
+				   this doesn't take mirrors into account */
+	u64 bytes_used;		/* total bytes used,
+				   this doesn't take mirrors into account */
+	u64 bytes_pinned;	/* total bytes pinned, will be freed when the
+				   transaction finishes */
+	u64 bytes_reserved;	/* total bytes the allocator has reserved for
+				   current allocations */
+	u64 bytes_may_use;	/* number of bytes that may be used for
+				   delalloc/allocations */
+	u64 bytes_readonly;	/* total bytes that are read only */
+
+	u64 max_extent_size;	/* This will hold the maximum extent size of
+				   the space info if we had an ENOSPC in the
+				   allocator. */
+
+	unsigned int full:1;	/* indicates that we cannot allocate any more
+				   chunks for this space */
+	unsigned int chunk_alloc:1;	/* set if we are allocating a chunk */
+
+	unsigned int flush:1;		/* set if we are trying to make space */
+
+	unsigned int force_alloc;	/* set if we need to force a chunk
+					   alloc for this space */
+
+	u64 disk_used;		/* total bytes used on disk */
+	u64 disk_total;		/* total bytes on disk, takes mirrors into
+				   account */
+
+	u64 flags;
+
+	/*
+	 * bytes_pinned is kept in line with what is actually pinned, as in
+	 * we've called update_block_group and dropped the bytes_used counter
+	 * and increased the bytes_pinned counter.  However this means that
+	 * bytes_pinned does not reflect the bytes that will be pinned once the
+	 * delayed refs are flushed, so this counter is inc'ed every time we
+	 * call btrfs_free_extent so it is a realtime count of what will be
+	 * freed once the transaction is committed.  It will be zeroed every
+	 * time the transaction commits.
+	 */
+	struct percpu_counter total_bytes_pinned;
+
+	struct list_head list;
+	/* Protected by the spinlock 'lock'. */
+	struct list_head ro_bgs;
+	struct list_head priority_tickets;
+	struct list_head tickets;
+	/*
+	 * tickets_id just indicates the next ticket will be handled, so note
+	 * it's not stored per ticket.
+	 */
+	u64 tickets_id;
+
+	struct rw_semaphore groups_sem;
+	/* for block groups in our same type */
+	struct list_head block_groups[BTRFS_NR_RAID_TYPES];
+	wait_queue_head_t wait;
+
+	struct kobject kobj;
+	struct kobject *block_group_kobjs[BTRFS_NR_RAID_TYPES];
+};
+
+struct reserve_ticket {
+	u64 bytes;
+	int error;
+	struct list_head list;
+	wait_queue_head_t wait;
+};
+
+static inline bool btrfs_mixed_space_info(struct btrfs_space_info *space_info)
+{
+	return ((space_info->flags & BTRFS_BLOCK_GROUP_METADATA) &&
+		(space_info->flags & BTRFS_BLOCK_GROUP_DATA));
+}
+
+/*
+ *
+ * Declare a helper function to detect underflow of various space info members
+ */
+#define DECLARE_SPACE_INFO_UPDATE(name, trace_name)			\
+static inline void							\
+btrfs_space_info_update_##name(struct btrfs_fs_info *fs_info,		\
+			       struct btrfs_space_info *sinfo,		\
+			       s64 bytes)				\
+{									\
+	const u64 abs_bytes = (bytes < 0) ? -bytes : bytes;		\
+	lockdep_assert_held(&sinfo->lock);				\
+	trace_update_##name(fs_info, sinfo, sinfo->name, bytes);	\
+	trace_btrfs_space_reservation(fs_info, trace_name,		\
+				      sinfo->flags, abs_bytes,		\
+				      bytes > 0);			\
+	if (bytes < 0 && sinfo->name < -bytes) {			\
+		WARN_ON(1);						\
+		sinfo->name = 0;					\
+		return;							\
+	}								\
+	sinfo->name += bytes;						\
+}
+
+DECLARE_SPACE_INFO_UPDATE(bytes_may_use, "space_info");
+DECLARE_SPACE_INFO_UPDATE(bytes_pinned, "pinned");
+
+int btrfs_init_space_info(struct btrfs_fs_info *fs_info);
+void btrfs_update_space_info(struct btrfs_fs_info *info, u64 flags,
+			     u64 total_bytes, u64 bytes_used,
+			     u64 bytes_readonly,
+			     struct btrfs_space_info **space_info);
+struct btrfs_space_info *btrfs_find_space_info(struct btrfs_fs_info *info,
+					       u64 flags);
+u64 btrfs_space_info_used(struct btrfs_space_info *s_info,
+			  bool may_use_included);
+void btrfs_clear_space_info_full(struct btrfs_fs_info *info);
+void btrfs_dump_space_info(struct btrfs_fs_info *fs_info,
+			   struct btrfs_space_info *info, u64 bytes,
+			   int dump_block_groups);
+int btrfs_reserve_metadata_bytes(struct btrfs_root *root,
+				 struct btrfs_block_rsv *block_rsv,
+				 u64 orig_bytes,
+				 enum btrfs_reserve_flush_enum flush);
+void btrfs_try_granting_tickets(struct btrfs_fs_info *fs_info,
+				struct btrfs_space_info *space_info);
+
+static inline void btrfs_space_info_free_bytes_may_use(
+				struct btrfs_fs_info *fs_info,
+				struct btrfs_space_info *space_info,
+				u64 num_bytes)
+{
+	spin_lock(&space_info->lock);
+	btrfs_space_info_update_bytes_may_use(fs_info, space_info, -num_bytes);
+	btrfs_try_granting_tickets(fs_info, space_info);
+	spin_unlock(&space_info->lock);
+}
+
+#endif /* BTRFS_SPACE_INFO_H */
diff --git a/fs/btrfs/struct-funcs.c b/fs/btrfs/struct-funcs.c
index 4c13b73..73f7987 100644
--- a/fs/btrfs/struct-funcs.c
+++ b/fs/btrfs/struct-funcs.c
@@ -33,6 +33,8 @@
  *
  * The extent buffer api is used to do the page spanning work required to
  * have a metadata blocksize different from the page size.
+ *
+ * There are 2 variants defined, one with a token pointer and one without.
  */
 
 #define DEFINE_BTRFS_SETGET_BITS(bits)					\
@@ -50,8 +52,10 @@
 	int size = sizeof(u##bits);					\
 	u##bits res;							\
 									\
-	if (token && token->kaddr && token->offset <= offset &&		\
-	    token->eb == eb &&						\
+	ASSERT(token);							\
+	ASSERT(token->eb == eb);					\
+									\
+	if (token->kaddr && token->offset <= offset &&			\
 	   (token->offset + PAGE_SIZE >= offset + size)) {	\
 		kaddr = token->kaddr;					\
 		p = kaddr + part_offset - token->offset;		\
@@ -68,11 +72,33 @@
 	}								\
 	p = kaddr + part_offset - map_start;				\
 	res = get_unaligned_le##bits(p + off);				\
-	if (token) {							\
-		token->kaddr = kaddr;					\
-		token->offset = map_start;				\
-		token->eb = eb;						\
+	token->kaddr = kaddr;						\
+	token->offset = map_start;					\
+	return res;							\
+}									\
+u##bits btrfs_get_##bits(const struct extent_buffer *eb,		\
+			 const void *ptr, unsigned long off)		\
+{									\
+	unsigned long part_offset = (unsigned long)ptr;			\
+	unsigned long offset = part_offset + off;			\
+	void *p;							\
+	int err;							\
+	char *kaddr;							\
+	unsigned long map_start;					\
+	unsigned long map_len;						\
+	int size = sizeof(u##bits);					\
+	u##bits res;							\
+									\
+	err = map_private_extent_buffer(eb, offset, size,		\
+					&kaddr, &map_start, &map_len);	\
+	if (err) {							\
+		__le##bits leres;					\
+									\
+		read_extent_buffer(eb, &leres, offset, size);		\
+		return le##bits##_to_cpu(leres);			\
 	}								\
+	p = kaddr + part_offset - map_start;				\
+	res = get_unaligned_le##bits(p + off);				\
 	return res;							\
 }									\
 void btrfs_set_token_##bits(struct extent_buffer *eb,			\
@@ -89,8 +115,10 @@
 	unsigned long map_len;						\
 	int size = sizeof(u##bits);					\
 									\
-	if (token && token->kaddr && token->offset <= offset &&		\
-	    token->eb == eb &&						\
+	ASSERT(token);							\
+	ASSERT(token->eb == eb);					\
+									\
+	if (token->kaddr && token->offset <= offset &&			\
 	   (token->offset + PAGE_SIZE >= offset + size)) {	\
 		kaddr = token->kaddr;					\
 		p = kaddr + part_offset - token->offset;		\
@@ -108,11 +136,32 @@
 	}								\
 	p = kaddr + part_offset - map_start;				\
 	put_unaligned_le##bits(val, p + off);				\
-	if (token) {							\
-		token->kaddr = kaddr;					\
-		token->offset = map_start;				\
-		token->eb = eb;						\
+	token->kaddr = kaddr;						\
+	token->offset = map_start;					\
+}									\
+void btrfs_set_##bits(struct extent_buffer *eb, void *ptr,		\
+		      unsigned long off, u##bits val)			\
+{									\
+	unsigned long part_offset = (unsigned long)ptr;			\
+	unsigned long offset = part_offset + off;			\
+	void *p;							\
+	int err;							\
+	char *kaddr;							\
+	unsigned long map_start;					\
+	unsigned long map_len;						\
+	int size = sizeof(u##bits);					\
+									\
+	err = map_private_extent_buffer(eb, offset, size,		\
+			&kaddr, &map_start, &map_len);			\
+	if (err) {							\
+		__le##bits val2;					\
+									\
+		val2 = cpu_to_le##bits(val);				\
+		write_extent_buffer(eb, &val2, offset, size);		\
+		return;							\
 	}								\
+	p = kaddr + part_offset - map_start;				\
+	put_unaligned_le##bits(val, p + off);				\
 }
 
 DEFINE_BTRFS_SETGET_BITS(8)
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 8ad1458..1b151af 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -42,7 +42,10 @@
 #include "dev-replace.h"
 #include "free-space-cache.h"
 #include "backref.h"
+#include "space-info.h"
+#include "sysfs.h"
 #include "tests/btrfs-tests.h"
+#include "block-group.h"
 
 #include "qgroup.h"
 #define CREATE_TRACE_POINTS
@@ -93,7 +96,7 @@
 
 /*
  * __btrfs_handle_fs_error decodes expected errors from the caller and
- * invokes the approciate error response.
+ * invokes the appropriate error response.
  */
 __cold
 void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function,
@@ -151,7 +154,7 @@
 	 * although there is no way to update the progress. It would add the
 	 * risk of a deadlock, therefore the canceling is omitted. The only
 	 * penalty is that some I/O remains active until the procedure
-	 * completes. The next time when the filesystem is mounted writeable
+	 * completes. The next time when the filesystem is mounted writable
 	 * again, the device replace operation continues.
 	 */
 }
@@ -529,7 +532,9 @@
 				if (token != Opt_compress &&
 				    token != Opt_compress_force)
 					info->compress_level =
-					  btrfs_compress_str2level(args[0].from);
+					  btrfs_compress_str2level(
+							BTRFS_COMPRESS_ZLIB,
+							args[0].from + 4);
 				btrfs_set_opt(info->mount_opt, COMPRESS);
 				btrfs_clear_opt(info->mount_opt, NODATACOW);
 				btrfs_clear_opt(info->mount_opt, NODATASUM);
@@ -542,9 +547,13 @@
 				btrfs_clear_opt(info->mount_opt, NODATASUM);
 				btrfs_set_fs_incompat(info, COMPRESS_LZO);
 				no_compress = 0;
-			} else if (strcmp(args[0].from, "zstd") == 0) {
+			} else if (strncmp(args[0].from, "zstd", 4) == 0) {
 				compress_type = "zstd";
 				info->compress_type = BTRFS_COMPRESS_ZSTD;
+				info->compress_level =
+					btrfs_compress_str2level(
+							 BTRFS_COMPRESS_ZSTD,
+							 args[0].from + 4);
 				btrfs_set_opt(info->mount_opt, COMPRESS);
 				btrfs_clear_opt(info->mount_opt, NODATACOW);
 				btrfs_clear_opt(info->mount_opt, NODATASUM);
@@ -1394,7 +1403,7 @@
 }
 
 static struct dentry *mount_subvol(const char *subvol_name, u64 subvol_objectid,
-				   const char *device_name, struct vfsmount *mnt)
+				   struct vfsmount *mnt)
 {
 	struct dentry *root;
 	int ret;
@@ -1458,56 +1467,6 @@
 	return root;
 }
 
-static int parse_security_options(char *orig_opts,
-				  struct security_mnt_opts *sec_opts)
-{
-	char *secdata = NULL;
-	int ret = 0;
-
-	secdata = alloc_secdata();
-	if (!secdata)
-		return -ENOMEM;
-	ret = security_sb_copy_data(orig_opts, secdata);
-	if (ret) {
-		free_secdata(secdata);
-		return ret;
-	}
-	ret = security_sb_parse_opts_str(secdata, sec_opts);
-	free_secdata(secdata);
-	return ret;
-}
-
-static int setup_security_options(struct btrfs_fs_info *fs_info,
-				  struct super_block *sb,
-				  struct security_mnt_opts *sec_opts)
-{
-	int ret = 0;
-
-	/*
-	 * Call security_sb_set_mnt_opts() to check whether new sec_opts
-	 * is valid.
-	 */
-	ret = security_sb_set_mnt_opts(sb, sec_opts, 0, NULL);
-	if (ret)
-		return ret;
-
-#ifdef CONFIG_SECURITY
-	if (!fs_info->security_opts.num_mnt_opts) {
-		/* first time security setup, copy sec_opts to fs_info */
-		memcpy(&fs_info->security_opts, sec_opts, sizeof(*sec_opts));
-	} else {
-		/*
-		 * Since SELinux (the only one supporting security_mnt_opts)
-		 * does NOT support changing context during remount/mount of
-		 * the same sb, this must be the same or part of the same
-		 * security options, just free it.
-		 */
-		security_free_mnt_opts(sec_opts);
-	}
-#endif
-	return ret;
-}
-
 /*
  * Find a superblock for the given device / mount point.
  *
@@ -1522,16 +1481,15 @@
 	struct btrfs_device *device = NULL;
 	struct btrfs_fs_devices *fs_devices = NULL;
 	struct btrfs_fs_info *fs_info = NULL;
-	struct security_mnt_opts new_sec_opts;
+	void *new_sec_opts = NULL;
 	fmode_t mode = FMODE_READ;
 	int error = 0;
 
 	if (!(flags & SB_RDONLY))
 		mode |= FMODE_WRITE;
 
-	security_init_mnt_opts(&new_sec_opts);
 	if (data) {
-		error = parse_security_options(data, &new_sec_opts);
+		error = security_sb_eat_lsm_opts(data, &new_sec_opts);
 		if (error)
 			return ERR_PTR(error);
 	}
@@ -1550,7 +1508,6 @@
 
 	fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
 	fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
-	security_init_mnt_opts(&fs_info->security_opts);
 	if (!fs_info->super_copy || !fs_info->super_for_commit) {
 		error = -ENOMEM;
 		goto error_fs_info;
@@ -1599,18 +1556,16 @@
 	} else {
 		snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
 		btrfs_sb(s)->bdev_holder = fs_type;
+		if (!strstr(crc32c_impl(), "generic"))
+			set_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags);
 		error = btrfs_fill_super(s, fs_devices, data);
 	}
+	if (!error)
+		error = security_sb_set_mnt_opts(s, new_sec_opts, 0, NULL);
+	security_free_mnt_opts(&new_sec_opts);
 	if (error) {
 		deactivate_locked_super(s);
-		goto error_sec_opts;
-	}
-
-	fs_info = btrfs_sb(s);
-	error = setup_security_options(fs_info, s, &new_sec_opts);
-	if (error) {
-		deactivate_locked_super(s);
-		goto error_sec_opts;
+		return ERR_PTR(error);
 	}
 
 	return dget(s->s_root);
@@ -1651,14 +1606,10 @@
 {
 	struct vfsmount *mnt_root;
 	struct dentry *root;
-	fmode_t mode = FMODE_READ;
 	char *subvol_name = NULL;
 	u64 subvol_objectid = 0;
 	int error = 0;
 
-	if (!(flags & SB_RDONLY))
-		mode |= FMODE_WRITE;
-
 	error = btrfs_parse_subvol_options(data, &subvol_name,
 					&subvol_objectid);
 	if (error) {
@@ -1677,6 +1628,7 @@
 				flags | SB_RDONLY, device_name, data);
 			if (IS_ERR(mnt_root)) {
 				root = ERR_CAST(mnt_root);
+				kfree(subvol_name);
 				goto out;
 			}
 
@@ -1686,17 +1638,19 @@
 			if (error < 0) {
 				root = ERR_PTR(error);
 				mntput(mnt_root);
+				kfree(subvol_name);
 				goto out;
 			}
 		}
 	}
 	if (IS_ERR(mnt_root)) {
 		root = ERR_CAST(mnt_root);
+		kfree(subvol_name);
 		goto out;
 	}
 
 	/* mount_subvol() will free subvol_name and mnt_root */
-	root = mount_subvol(subvol_name, subvol_objectid, device_name, mnt_root);
+	root = mount_subvol(subvol_name, subvol_objectid, mnt_root);
 
 out:
 	return root;
@@ -1779,18 +1733,14 @@
 	btrfs_remount_prepare(fs_info);
 
 	if (data) {
-		struct security_mnt_opts new_sec_opts;
+		void *new_sec_opts = NULL;
 
-		security_init_mnt_opts(&new_sec_opts);
-		ret = parse_security_options(data, &new_sec_opts);
+		ret = security_sb_eat_lsm_opts(data, &new_sec_opts);
+		if (!ret)
+			ret = security_sb_remount(sb, new_sec_opts);
+		security_free_mnt_opts(&new_sec_opts);
 		if (ret)
 			goto restore;
-		ret = setup_security_options(fs_info, sb,
-					     &new_sec_opts);
-		if (ret) {
-			security_free_mnt_opts(&new_sec_opts);
-			goto restore;
-		}
 	}
 
 	ret = btrfs_parse_options(fs_info, data, *flags);
@@ -1848,7 +1798,7 @@
 
 		if (!btrfs_check_rw_degradable(fs_info, NULL)) {
 			btrfs_warn(fs_info,
-				"too many missing devices, writeable remount is not allowed");
+		"too many missing devices, writable remount is not allowed");
 			ret = -EACCES;
 			goto restore;
 		}
@@ -1916,7 +1866,7 @@
 }
 
 /* Used to sort the devices by max_avail(descending sort) */
-static int btrfs_cmp_device_free_bytes(const void *dev_info1,
+static inline int btrfs_cmp_device_free_bytes(const void *dev_info1,
 				       const void *dev_info2)
 {
 	if (((struct btrfs_device_info *)dev_info1)->max_avail >
@@ -1945,18 +1895,18 @@
  * The helper to calc the free space on the devices that can be used to store
  * file data.
  */
-static int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info,
-				       u64 *free_bytes)
+static inline int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info,
+					      u64 *free_bytes)
 {
 	struct btrfs_device_info *devices_info;
 	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
 	struct btrfs_device *device;
-	u64 skip_space;
 	u64 type;
 	u64 avail_space;
 	u64 min_stripe_size;
-	int min_stripes = 1, num_stripes = 1;
+	int num_stripes = 1;
 	int i = 0, nr_devices;
+	const struct btrfs_raid_attr *rattr;
 
 	/*
 	 * We aren't under the device list lock, so this is racy-ish, but good
@@ -1980,21 +1930,17 @@
 
 	/* calc min stripe number for data space allocation */
 	type = btrfs_data_alloc_profile(fs_info);
-	if (type & BTRFS_BLOCK_GROUP_RAID0) {
-		min_stripes = 2;
-		num_stripes = nr_devices;
-	} else if (type & BTRFS_BLOCK_GROUP_RAID1) {
-		min_stripes = 2;
-		num_stripes = 2;
-	} else if (type & BTRFS_BLOCK_GROUP_RAID10) {
-		min_stripes = 4;
-		num_stripes = 4;
-	}
+	rattr = &btrfs_raid_array[btrfs_bg_flags_to_raid_index(type)];
 
-	if (type & BTRFS_BLOCK_GROUP_DUP)
-		min_stripe_size = 2 * BTRFS_STRIPE_LEN;
-	else
-		min_stripe_size = BTRFS_STRIPE_LEN;
+	if (type & BTRFS_BLOCK_GROUP_RAID0)
+		num_stripes = nr_devices;
+	else if (type & BTRFS_BLOCK_GROUP_RAID1)
+		num_stripes = 2;
+	else if (type & BTRFS_BLOCK_GROUP_RAID10)
+		num_stripes = 4;
+
+	/* Adjust for more than 1 stripe per device */
+	min_stripe_size = rattr->dev_stripes * BTRFS_STRIPE_LEN;
 
 	rcu_read_lock();
 	list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
@@ -2010,28 +1956,21 @@
 		avail_space = device->total_bytes - device->bytes_used;
 
 		/* align with stripe_len */
-		avail_space = div_u64(avail_space, BTRFS_STRIPE_LEN);
-		avail_space *= BTRFS_STRIPE_LEN;
+		avail_space = rounddown(avail_space, BTRFS_STRIPE_LEN);
 
 		/*
 		 * In order to avoid overwriting the superblock on the drive,
 		 * btrfs starts at an offset of at least 1MB when doing chunk
 		 * allocation.
+		 *
+		 * This ensures we have at least min_stripe_size free space
+		 * after excluding 1MB.
 		 */
-		skip_space = SZ_1M;
-
-		/*
-		 * we can use the free space in [0, skip_space - 1], subtract
-		 * it from the total.
-		 */
-		if (avail_space && avail_space >= skip_space)
-			avail_space -= skip_space;
-		else
-			avail_space = 0;
-
-		if (avail_space < min_stripe_size)
+		if (avail_space <= SZ_1M + min_stripe_size)
 			continue;
 
+		avail_space -= SZ_1M;
+
 		devices_info[i].dev = device;
 		devices_info[i].max_avail = avail_space;
 
@@ -2045,9 +1984,8 @@
 
 	i = nr_devices - 1;
 	avail_space = 0;
-	while (nr_devices >= min_stripes) {
-		if (num_stripes > nr_devices)
-			num_stripes = nr_devices;
+	while (nr_devices >= rattr->devs_min) {
+		num_stripes = min(num_stripes, nr_devices);
 
 		if (devices_info[i].max_avail >= min_stripe_size) {
 			int j;
@@ -2090,7 +2028,7 @@
 	u64 total_free_data = 0;
 	u64 total_free_meta = 0;
 	int bits = dentry->d_sb->s_blocksize_bits;
-	__be32 *fsid = (__be32 *)fs_info->fsid;
+	__be32 *fsid = (__be32 *)fs_info->fs_devices->fsid;
 	unsigned factor = 1;
 	struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 	int ret;
@@ -2177,8 +2115,10 @@
 	buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
 	buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
 	/* Mask in the root object ID too, to disambiguate subvols */
-	buf->f_fsid.val[0] ^= BTRFS_I(d_inode(dentry))->root->objectid >> 32;
-	buf->f_fsid.val[1] ^= BTRFS_I(d_inode(dentry))->root->objectid;
+	buf->f_fsid.val[0] ^=
+		BTRFS_I(d_inode(dentry))->root->root_key.objectid >> 32;
+	buf->f_fsid.val[1] ^=
+		BTRFS_I(d_inode(dentry))->root->root_key.objectid;
 
 	return 0;
 }
@@ -2245,6 +2185,9 @@
 		ret = PTR_ERR_OR_ZERO(device);
 		mutex_unlock(&uuid_mutex);
 		break;
+	case BTRFS_IOC_FORGET_DEV:
+		ret = btrfs_forget_devices(vol->name);
+		break;
 	case BTRFS_IOC_DEVICES_READY:
 		mutex_lock(&uuid_mutex);
 		device = btrfs_scan_one_device(vol->name, FMODE_READ,
@@ -2310,7 +2253,7 @@
 	 * device_list_mutex here as we only read the device data and the list
 	 * is protected by RCU.  Even if a device is deleted during the list
 	 * traversals, we'll get valid data, the freeing callback will wait at
-	 * least until until the rcu_read_unlock.
+	 * least until the rcu_read_unlock.
 	 */
 	rcu_read_lock();
 	cur_devices = fs_info->fs_devices;
@@ -2344,6 +2287,7 @@
 	.show_devname	= btrfs_show_devname,
 	.alloc_inode	= btrfs_alloc_inode,
 	.destroy_inode	= btrfs_destroy_inode,
+	.free_inode	= btrfs_free_inode,
 	.statfs		= btrfs_statfs,
 	.remount_fs	= btrfs_remount,
 	.freeze_fs	= btrfs_freeze,
@@ -2511,3 +2455,4 @@
 module_exit(exit_btrfs_fs)
 
 MODULE_LICENSE("GPL");
+MODULE_SOFTDEP("pre: crc32c");
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 3717c86..f6d3c80 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -4,22 +4,87 @@
  */
 
 #include <linux/sched.h>
+#include <linux/sched/mm.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/completion.h>
-#include <linux/kobject.h>
 #include <linux/bug.h>
-#include <linux/debugfs.h>
 
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
 #include "sysfs.h"
 #include "volumes.h"
+#include "space-info.h"
+#include "block-group.h"
+
+struct btrfs_feature_attr {
+	struct kobj_attribute kobj_attr;
+	enum btrfs_feature_set feature_set;
+	u64 feature_bit;
+};
+
+/* For raid type sysfs entries */
+struct raid_kobject {
+	u64 flags;
+	struct kobject kobj;
+};
+
+#define __INIT_KOBJ_ATTR(_name, _mode, _show, _store)			\
+{									\
+	.attr	= { .name = __stringify(_name), .mode = _mode },	\
+	.show	= _show,						\
+	.store	= _store,						\
+}
+
+#define BTRFS_ATTR_RW(_prefix, _name, _show, _store)			\
+	static struct kobj_attribute btrfs_attr_##_prefix##_##_name =	\
+			__INIT_KOBJ_ATTR(_name, 0644, _show, _store)
+
+#define BTRFS_ATTR(_prefix, _name, _show)				\
+	static struct kobj_attribute btrfs_attr_##_prefix##_##_name =	\
+			__INIT_KOBJ_ATTR(_name, 0444, _show, NULL)
+
+#define BTRFS_ATTR_PTR(_prefix, _name)					\
+	(&btrfs_attr_##_prefix##_##_name.attr)
+
+#define BTRFS_FEAT_ATTR(_name, _feature_set, _feature_prefix, _feature_bit)  \
+static struct btrfs_feature_attr btrfs_attr_features_##_name = {	     \
+	.kobj_attr = __INIT_KOBJ_ATTR(_name, S_IRUGO,			     \
+				      btrfs_feature_attr_show,		     \
+				      btrfs_feature_attr_store),	     \
+	.feature_set	= _feature_set,					     \
+	.feature_bit	= _feature_prefix ##_## _feature_bit,		     \
+}
+#define BTRFS_FEAT_ATTR_PTR(_name)					     \
+	(&btrfs_attr_features_##_name.kobj_attr.attr)
+
+#define BTRFS_FEAT_ATTR_COMPAT(name, feature) \
+	BTRFS_FEAT_ATTR(name, FEAT_COMPAT, BTRFS_FEATURE_COMPAT, feature)
+#define BTRFS_FEAT_ATTR_COMPAT_RO(name, feature) \
+	BTRFS_FEAT_ATTR(name, FEAT_COMPAT_RO, BTRFS_FEATURE_COMPAT_RO, feature)
+#define BTRFS_FEAT_ATTR_INCOMPAT(name, feature) \
+	BTRFS_FEAT_ATTR(name, FEAT_INCOMPAT, BTRFS_FEATURE_INCOMPAT, feature)
 
 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj);
 
+static struct btrfs_feature_attr *to_btrfs_feature_attr(struct kobj_attribute *a)
+{
+	return container_of(a, struct btrfs_feature_attr, kobj_attr);
+}
+
+static struct kobj_attribute *attr_to_btrfs_attr(struct attribute *attr)
+{
+	return container_of(attr, struct kobj_attribute, attr);
+}
+
+static struct btrfs_feature_attr *attr_to_btrfs_feature_attr(
+		struct attribute *attr)
+{
+	return to_btrfs_feature_attr(attr_to_btrfs_attr(attr));
+}
+
 static u64 get_features(struct btrfs_fs_info *fs_info,
 			enum btrfs_feature_set set)
 {
@@ -191,6 +256,7 @@
 BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
 BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
 BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
+BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID);
 BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
 
 static struct attribute *btrfs_supported_feature_attrs[] = {
@@ -204,6 +270,7 @@
 	BTRFS_FEAT_ATTR_PTR(raid56),
 	BTRFS_FEAT_ATTR_PTR(skinny_metadata),
 	BTRFS_FEAT_ATTR_PTR(no_holes),
+	BTRFS_FEAT_ATTR_PTR(metadata_uuid),
 	BTRFS_FEAT_ATTR_PTR(free_space_tree),
 	NULL
 };
@@ -244,6 +311,25 @@
 	.attrs = btrfs_supported_static_feature_attrs,
 };
 
+#ifdef CONFIG_BTRFS_DEBUG
+
+/*
+ * Runtime debugging exported via sysfs
+ *
+ * /sys/fs/btrfs/debug - applies to module or all filesystems
+ * /sys/fs/btrfs/UUID  - applies only to the given filesystem
+ */
+static struct attribute *btrfs_debug_feature_attrs[] = {
+	NULL
+};
+
+static const struct attribute_group btrfs_debug_feature_attr_group = {
+	.name = "debug",
+	.attrs = btrfs_debug_feature_attrs,
+};
+
+#endif
+
 static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
 {
 	u64 val;
@@ -301,21 +387,22 @@
 	return snprintf(buf, PAGE_SIZE, "%llu\n", val);
 }
 
-static struct attribute *raid_attributes[] = {
+static struct attribute *raid_attrs[] = {
 	BTRFS_ATTR_PTR(raid, total_bytes),
 	BTRFS_ATTR_PTR(raid, used_bytes),
 	NULL
 };
+ATTRIBUTE_GROUPS(raid);
 
 static void release_raid_kobj(struct kobject *kobj)
 {
 	kfree(to_raid_kobj(kobj));
 }
 
-struct kobj_type btrfs_raid_ktype = {
+static struct kobj_type btrfs_raid_ktype = {
 	.sysfs_ops = &kobj_sysfs_ops,
 	.release = release_raid_kobj,
-	.default_attrs = raid_attributes,
+	.default_groups = raid_groups,
 };
 
 #define SPACE_INFO_ATTR(field)						\
@@ -362,6 +449,7 @@
 	BTRFS_ATTR_PTR(space_info, total_bytes_pinned),
 	NULL,
 };
+ATTRIBUTE_GROUPS(space_info);
 
 static void space_info_release(struct kobject *kobj)
 {
@@ -370,10 +458,10 @@
 	kfree(sinfo);
 }
 
-struct kobj_type space_info_ktype = {
+static struct kobj_type space_info_ktype = {
 	.sysfs_ops = &kobj_sysfs_ops,
 	.release = space_info_release,
-	.default_attrs = space_info_attrs,
+	.default_groups = space_info_groups,
 };
 
 static const struct attribute *allocation_attrs[] = {
@@ -505,12 +593,24 @@
 
 BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
 
+static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
+				struct kobj_attribute *a, char *buf)
+{
+	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
+
+	return snprintf(buf, PAGE_SIZE, "%pU\n",
+			fs_info->fs_devices->metadata_uuid);
+}
+
+BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
+
 static const struct attribute *btrfs_attrs[] = {
 	BTRFS_ATTR_PTR(, label),
 	BTRFS_ATTR_PTR(, nodesize),
 	BTRFS_ATTR_PTR(, sectorsize),
 	BTRFS_ATTR_PTR(, clone_alignment),
 	BTRFS_ATTR_PTR(, quota_override),
+	BTRFS_ATTR_PTR(, metadata_uuid),
 	NULL,
 };
 
@@ -638,12 +738,17 @@
 	btrfs_sysfs_rm_device_link(fs_info->fs_devices, NULL);
 }
 
-const char * const btrfs_feature_set_names[FEAT_MAX] = {
+static const char * const btrfs_feature_set_names[FEAT_MAX] = {
 	[FEAT_COMPAT]	 = "compat",
 	[FEAT_COMPAT_RO] = "compat_ro",
 	[FEAT_INCOMPAT]	 = "incompat",
 };
 
+const char * const btrfs_feature_set_name(enum btrfs_feature_set set)
+{
+	return btrfs_feature_set_names[set];
+}
+
 char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
 {
 	size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
@@ -713,6 +818,110 @@
 	}
 }
 
+/*
+ * Create a sysfs entry for a given block group type at path
+ * /sys/fs/btrfs/UUID/allocation/data/TYPE
+ */
+void btrfs_sysfs_add_block_group_type(struct btrfs_block_group_cache *cache)
+{
+	struct btrfs_fs_info *fs_info = cache->fs_info;
+	struct btrfs_space_info *space_info = cache->space_info;
+	struct raid_kobject *rkobj;
+	const int index = btrfs_bg_flags_to_raid_index(cache->flags);
+	unsigned int nofs_flag;
+	int ret;
+
+	/*
+	 * Setup a NOFS context because kobject_add(), deep in its call chain,
+	 * does GFP_KERNEL allocations, and we are often called in a context
+	 * where if reclaim is triggered we can deadlock (we are either holding
+	 * a transaction handle or some lock required for a transaction
+	 * commit).
+	 */
+	nofs_flag = memalloc_nofs_save();
+
+	rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
+	if (!rkobj) {
+		memalloc_nofs_restore(nofs_flag);
+		btrfs_warn(cache->fs_info,
+				"couldn't alloc memory for raid level kobject");
+		return;
+	}
+
+	rkobj->flags = cache->flags;
+	kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
+	ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
+			  btrfs_bg_type_to_raid_name(rkobj->flags));
+	memalloc_nofs_restore(nofs_flag);
+	if (ret) {
+		kobject_put(&rkobj->kobj);
+		btrfs_warn(fs_info,
+			"failed to add kobject for block cache, ignoring");
+		return;
+	}
+
+	space_info->block_group_kobjs[index] = &rkobj->kobj;
+}
+
+/*
+ * Remove sysfs directories for all block group types of a given space info and
+ * the space info as well
+ */
+void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
+{
+	int i;
+
+	for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
+		struct kobject *kobj;
+
+		kobj = space_info->block_group_kobjs[i];
+		space_info->block_group_kobjs[i] = NULL;
+		if (kobj) {
+			kobject_del(kobj);
+			kobject_put(kobj);
+		}
+	}
+	kobject_del(&space_info->kobj);
+	kobject_put(&space_info->kobj);
+}
+
+static const char *alloc_name(u64 flags)
+{
+	switch (flags) {
+	case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
+		return "mixed";
+	case BTRFS_BLOCK_GROUP_METADATA:
+		return "metadata";
+	case BTRFS_BLOCK_GROUP_DATA:
+		return "data";
+	case BTRFS_BLOCK_GROUP_SYSTEM:
+		return "system";
+	default:
+		WARN_ON(1);
+		return "invalid-combination";
+	};
+}
+
+/*
+ * Create a sysfs entry for a space info type at path
+ * /sys/fs/btrfs/UUID/allocation/TYPE
+ */
+int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
+				    struct btrfs_space_info *space_info)
+{
+	int ret;
+
+	ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
+				   fs_info->space_info_kobj, "%s",
+				   alloc_name(space_info->flags));
+	if (ret) {
+		kobject_put(&space_info->kobj);
+		return ret;
+	}
+
+	return 0;
+}
+
 /* when one_device is NULL, it removes all device links */
 
 int btrfs_sysfs_rm_device_link(struct btrfs_fs_devices *fs_devices,
@@ -789,15 +998,35 @@
 	return error;
 }
 
+void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
+{
+	int ret;
+
+	ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
+	if (ret)
+		pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
+			action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
+			&disk_to_dev(bdev->bd_disk)->kobj);
+}
+
+void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices,
+				    const u8 *fsid)
+{
+	char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
+
+	/*
+	 * Sprouting changes fsid of the mounted filesystem, rename the fsid
+	 * directory
+	 */
+	snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU", fsid);
+	if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
+		btrfs_warn(fs_devices->fs_info,
+				"sysfs: failed to create fsid for sprout");
+}
+
 /* /sys/fs/btrfs/ entry */
 static struct kset *btrfs_kset;
 
-/* /sys/kernel/debug/btrfs */
-static struct dentry *btrfs_debugfs_root_dentry;
-
-/* Debugging tunables and exported data */
-u64 btrfs_debugfs_test;
-
 /*
  * Can be called by the device discovery thread.
  * And parent can be specified for seed device
@@ -811,7 +1040,12 @@
 	fs_devs->fsid_kobj.kset = btrfs_kset;
 	error = kobject_init_and_add(&fs_devs->fsid_kobj,
 				&btrfs_ktype, parent, "%pU", fs_devs->fsid);
-	return error;
+	if (error) {
+		kobject_put(&fs_devs->fsid_kobj);
+		return error;
+	}
+
+	return 0;
 }
 
 int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
@@ -837,6 +1071,13 @@
 	if (error)
 		goto failure;
 
+#ifdef CONFIG_BTRFS_DEBUG
+	error = sysfs_create_group(fsid_kobj,
+				   &btrfs_debug_feature_attr_group);
+	if (error)
+		goto failure;
+#endif
+
 	error = addrm_unknown_feature_attrs(fs_info, true);
 	if (error)
 		goto failure;
@@ -891,28 +1132,6 @@
 	ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
 }
 
-static int btrfs_init_debugfs(void)
-{
-#ifdef CONFIG_DEBUG_FS
-	btrfs_debugfs_root_dentry = debugfs_create_dir("btrfs", NULL);
-	if (!btrfs_debugfs_root_dentry)
-		return -ENOMEM;
-
-	/*
-	 * Example code, how to export data through debugfs.
-	 *
-	 * file:        /sys/kernel/debug/btrfs/test
-	 * contents of: btrfs_debugfs_test
-	 */
-#ifdef CONFIG_BTRFS_DEBUG
-	debugfs_create_u64("test", S_IRUGO | S_IWUSR, btrfs_debugfs_root_dentry,
-			&btrfs_debugfs_test);
-#endif
-
-#endif
-	return 0;
-}
-
 int __init btrfs_init_sysfs(void)
 {
 	int ret;
@@ -921,10 +1140,6 @@
 	if (!btrfs_kset)
 		return -ENOMEM;
 
-	ret = btrfs_init_debugfs();
-	if (ret)
-		goto out1;
-
 	init_feature_attrs();
 	ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
 	if (ret)
@@ -934,13 +1149,17 @@
 	if (ret)
 		goto out_remove_group;
 
+#ifdef CONFIG_BTRFS_DEBUG
+	ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
+	if (ret)
+		goto out2;
+#endif
+
 	return 0;
 
 out_remove_group:
 	sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
 out2:
-	debugfs_remove_recursive(btrfs_debugfs_root_dentry);
-out1:
 	kset_unregister(btrfs_kset);
 
 	return ret;
@@ -952,6 +1171,5 @@
 			    &btrfs_static_feature_attr_group);
 	sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
 	kset_unregister(btrfs_kset);
-	debugfs_remove_recursive(btrfs_debugfs_root_dentry);
 }
 
diff --git a/fs/btrfs/sysfs.h b/fs/btrfs/sysfs.h
index c6ee600..610e9c3 100644
--- a/fs/btrfs/sysfs.h
+++ b/fs/btrfs/sysfs.h
@@ -3,83 +3,17 @@
 #ifndef BTRFS_SYSFS_H
 #define BTRFS_SYSFS_H
 
-/*
- * Data exported through sysfs
- */
-extern u64 btrfs_debugfs_test;
+#include <linux/kobject.h>
 
 enum btrfs_feature_set {
-	FEAT_COMPAT = 0,
+	FEAT_COMPAT,
 	FEAT_COMPAT_RO,
 	FEAT_INCOMPAT,
 	FEAT_MAX
 };
 
-#define __INIT_KOBJ_ATTR(_name, _mode, _show, _store)			\
-{									\
-	.attr	= { .name = __stringify(_name), .mode = _mode },	\
-	.show	= _show,						\
-	.store	= _store,						\
-}
-
-#define BTRFS_ATTR_RW(_prefix, _name, _show, _store)			\
-	static struct kobj_attribute btrfs_attr_##_prefix##_##_name =	\
-			__INIT_KOBJ_ATTR(_name, 0644, _show, _store)
-
-#define BTRFS_ATTR(_prefix, _name, _show)				\
-	static struct kobj_attribute btrfs_attr_##_prefix##_##_name =	\
-			__INIT_KOBJ_ATTR(_name, 0444, _show, NULL)
-
-#define BTRFS_ATTR_PTR(_prefix, _name)					\
-	(&btrfs_attr_##_prefix##_##_name.attr)
-
-
-struct btrfs_feature_attr {
-	struct kobj_attribute kobj_attr;
-	enum btrfs_feature_set feature_set;
-	u64 feature_bit;
-};
-
-#define BTRFS_FEAT_ATTR(_name, _feature_set, _feature_prefix, _feature_bit)  \
-static struct btrfs_feature_attr btrfs_attr_features_##_name = {	     \
-	.kobj_attr = __INIT_KOBJ_ATTR(_name, S_IRUGO,			     \
-				      btrfs_feature_attr_show,		     \
-				      btrfs_feature_attr_store),	     \
-	.feature_set	= _feature_set,					     \
-	.feature_bit	= _feature_prefix ##_## _feature_bit,		     \
-}
-#define BTRFS_FEAT_ATTR_PTR(_name)					     \
-	(&btrfs_attr_features_##_name.kobj_attr.attr)
-
-#define BTRFS_FEAT_ATTR_COMPAT(name, feature) \
-	BTRFS_FEAT_ATTR(name, FEAT_COMPAT, BTRFS_FEATURE_COMPAT, feature)
-#define BTRFS_FEAT_ATTR_COMPAT_RO(name, feature) \
-	BTRFS_FEAT_ATTR(name, FEAT_COMPAT_RO, BTRFS_FEATURE_COMPAT_RO, feature)
-#define BTRFS_FEAT_ATTR_INCOMPAT(name, feature) \
-	BTRFS_FEAT_ATTR(name, FEAT_INCOMPAT, BTRFS_FEATURE_INCOMPAT, feature)
-
-/* convert from attribute */
-static inline struct btrfs_feature_attr *
-to_btrfs_feature_attr(struct kobj_attribute *a)
-{
-	return container_of(a, struct btrfs_feature_attr, kobj_attr);
-}
-
-static inline struct kobj_attribute *attr_to_btrfs_attr(struct attribute *attr)
-{
-	return container_of(attr, struct kobj_attribute, attr);
-}
-
-static inline struct btrfs_feature_attr *
-attr_to_btrfs_feature_attr(struct attribute *attr)
-{
-	return to_btrfs_feature_attr(attr_to_btrfs_attr(attr));
-}
-
 char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags);
-extern const char * const btrfs_feature_set_names[FEAT_MAX];
-extern struct kobj_type space_info_ktype;
-extern struct kobj_type btrfs_raid_ktype;
+const char * const btrfs_feature_set_name(enum btrfs_feature_set set);
 int btrfs_sysfs_add_device_link(struct btrfs_fs_devices *fs_devices,
 		struct btrfs_device *one_device);
 int btrfs_sysfs_rm_device_link(struct btrfs_fs_devices *fs_devices,
@@ -88,7 +22,19 @@
 				struct kobject *parent);
 int btrfs_sysfs_add_device(struct btrfs_fs_devices *fs_devs);
 void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs);
+void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices,
+				    const u8 *fsid);
 void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
 		u64 bit, enum btrfs_feature_set set);
+void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action);
+
+int __init btrfs_init_sysfs(void);
+void __cold btrfs_exit_sysfs(void);
+int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info);
+void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info);
+void btrfs_sysfs_add_block_group_type(struct btrfs_block_group_cache *cache);
+int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
+				    struct btrfs_space_info *space_info);
+void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info);
 
 #endif
diff --git a/fs/btrfs/tests/btrfs-tests.c b/fs/btrfs/tests/btrfs-tests.c
index db72b3b..99fe9bf 100644
--- a/fs/btrfs/tests/btrfs-tests.c
+++ b/fs/btrfs/tests/btrfs-tests.c
@@ -5,6 +5,7 @@
 
 #include <linux/fs.h>
 #include <linux/mount.h>
+#include <linux/pseudo_fs.h>
 #include <linux/magic.h>
 #include "btrfs-tests.h"
 #include "../ctree.h"
@@ -14,31 +15,50 @@
 #include "../volumes.h"
 #include "../disk-io.h"
 #include "../qgroup.h"
+#include "../block-group.h"
 
 static struct vfsmount *test_mnt = NULL;
 
+const char *test_error[] = {
+	[TEST_ALLOC_FS_INFO]	     = "cannot allocate fs_info",
+	[TEST_ALLOC_ROOT]	     = "cannot allocate root",
+	[TEST_ALLOC_EXTENT_BUFFER]   = "cannot extent buffer",
+	[TEST_ALLOC_PATH]	     = "cannot allocate path",
+	[TEST_ALLOC_INODE]	     = "cannot allocate inode",
+	[TEST_ALLOC_BLOCK_GROUP]     = "cannot allocate block group",
+	[TEST_ALLOC_EXTENT_MAP]      = "cannot allocate extent map",
+};
+
 static const struct super_operations btrfs_test_super_ops = {
 	.alloc_inode	= btrfs_alloc_inode,
 	.destroy_inode	= btrfs_test_destroy_inode,
 };
 
-static struct dentry *btrfs_test_mount(struct file_system_type *fs_type,
-				       int flags, const char *dev_name,
-				       void *data)
+
+static int btrfs_test_init_fs_context(struct fs_context *fc)
 {
-	return mount_pseudo(fs_type, "btrfs_test:", &btrfs_test_super_ops,
-			    NULL, BTRFS_TEST_MAGIC);
+	struct pseudo_fs_context *ctx = init_pseudo(fc, BTRFS_TEST_MAGIC);
+	if (!ctx)
+		return -ENOMEM;
+	ctx->ops = &btrfs_test_super_ops;
+	return 0;
 }
 
 static struct file_system_type test_type = {
 	.name		= "btrfs_test_fs",
-	.mount		= btrfs_test_mount,
+	.init_fs_context = btrfs_test_init_fs_context,
 	.kill_sb	= kill_anon_super,
 };
 
 struct inode *btrfs_new_test_inode(void)
 {
-	return new_inode(test_mnt->mnt_sb);
+	struct inode *inode;
+
+	inode = new_inode(test_mnt->mnt_sb);
+	if (inode)
+		inode_init_owner(inode, NULL, S_IFREG);
+
+	return inode;
 }
 
 static int btrfs_init_test_fs(void)
@@ -99,7 +119,6 @@
 
 	spin_lock_init(&fs_info->buffer_lock);
 	spin_lock_init(&fs_info->qgroup_lock);
-	spin_lock_init(&fs_info->qgroup_op_lock);
 	spin_lock_init(&fs_info->super_lock);
 	spin_lock_init(&fs_info->fs_roots_radix_lock);
 	spin_lock_init(&fs_info->tree_mod_seq_lock);
@@ -115,8 +134,10 @@
 	INIT_LIST_HEAD(&fs_info->tree_mod_seq_list);
 	INIT_RADIX_TREE(&fs_info->buffer_radix, GFP_ATOMIC);
 	INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
-	extent_io_tree_init(&fs_info->freed_extents[0], NULL);
-	extent_io_tree_init(&fs_info->freed_extents[1], NULL);
+	extent_io_tree_init(fs_info, &fs_info->freed_extents[0],
+			    IO_TREE_FS_INFO_FREED_EXTENTS0, NULL);
+	extent_io_tree_init(fs_info, &fs_info->freed_extents[1],
+			    IO_TREE_FS_INFO_FREED_EXTENTS1, NULL);
 	fs_info->pinned_extents = &fs_info->freed_extents[0];
 	set_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state);
 
@@ -174,8 +195,10 @@
 	/* Will be freed by btrfs_free_fs_roots */
 	if (WARN_ON(test_bit(BTRFS_ROOT_IN_RADIX, &root->state)))
 		return;
-	if (root->node)
+	if (root->node) {
+		/* One for allocate_extent_buffer */
 		free_extent_buffer(root->node);
+	}
 	kfree(root);
 }
 
diff --git a/fs/btrfs/tests/btrfs-tests.h b/fs/btrfs/tests/btrfs-tests.h
index 70ff9f9..ee277bb 100644
--- a/fs/btrfs/tests/btrfs-tests.h
+++ b/fs/btrfs/tests/btrfs-tests.h
@@ -10,7 +10,22 @@
 int btrfs_run_sanity_tests(void);
 
 #define test_msg(fmt, ...) pr_info("BTRFS: selftest: " fmt "\n", ##__VA_ARGS__)
-#define test_err(fmt, ...) pr_err("BTRFS: selftest: " fmt "\n", ##__VA_ARGS__)
+#define test_err(fmt, ...) pr_err("BTRFS: selftest: %s:%d " fmt "\n",	\
+		__FILE__, __LINE__, ##__VA_ARGS__)
+
+#define test_std_err(index)	test_err("%s", test_error[index])
+
+enum {
+	TEST_ALLOC_FS_INFO,
+	TEST_ALLOC_ROOT,
+	TEST_ALLOC_EXTENT_BUFFER,
+	TEST_ALLOC_PATH,
+	TEST_ALLOC_INODE,
+	TEST_ALLOC_BLOCK_GROUP,
+	TEST_ALLOC_EXTENT_MAP,
+};
+
+extern const char *test_error[];
 
 struct btrfs_root;
 struct btrfs_trans_handle;
diff --git a/fs/btrfs/tests/extent-buffer-tests.c b/fs/btrfs/tests/extent-buffer-tests.c
index 7d72eab..a1b9f9b 100644
--- a/fs/btrfs/tests/extent-buffer-tests.c
+++ b/fs/btrfs/tests/extent-buffer-tests.c
@@ -30,27 +30,27 @@
 
 	fs_info = btrfs_alloc_dummy_fs_info(nodesize, sectorsize);
 	if (!fs_info) {
-		test_err("could not allocate fs_info");
+		test_std_err(TEST_ALLOC_FS_INFO);
 		return -ENOMEM;
 	}
 
 	root = btrfs_alloc_dummy_root(fs_info);
 	if (IS_ERR(root)) {
-		test_err("could not allocate root");
+		test_std_err(TEST_ALLOC_ROOT);
 		ret = PTR_ERR(root);
 		goto out;
 	}
 
 	path = btrfs_alloc_path();
 	if (!path) {
-		test_err("could not allocate path");
+		test_std_err(TEST_ALLOC_PATH);
 		ret = -ENOMEM;
 		goto out;
 	}
 
 	path->nodes[0] = eb = alloc_dummy_extent_buffer(fs_info, nodesize);
 	if (!eb) {
-		test_err("could not allocate dummy buffer");
+		test_std_err(TEST_ALLOC_EXTENT_BUFFER);
 		ret = -ENOMEM;
 		goto out;
 	}
diff --git a/fs/btrfs/tests/extent-io-tests.c b/fs/btrfs/tests/extent-io-tests.c
index d9269a5..123d9a6 100644
--- a/fs/btrfs/tests/extent-io-tests.c
+++ b/fs/btrfs/tests/extent-io-tests.c
@@ -10,6 +10,7 @@
 #include "btrfs-tests.h"
 #include "../ctree.h"
 #include "../extent_io.h"
+#include "../btrfs_inode.h"
 
 #define PROCESS_UNLOCK		(1 << 0)
 #define PROCESS_RELEASE		(1 << 1)
@@ -58,25 +59,31 @@
 static int test_find_delalloc(u32 sectorsize)
 {
 	struct inode *inode;
-	struct extent_io_tree tmp;
+	struct extent_io_tree *tmp;
 	struct page *page;
 	struct page *locked_page = NULL;
 	unsigned long index = 0;
-	u64 total_dirty = SZ_256M;
-	u64 max_bytes = SZ_128M;
+	/* In this test we need at least 2 file extents at its maximum size */
+	u64 max_bytes = BTRFS_MAX_EXTENT_SIZE;
+	u64 total_dirty = 2 * max_bytes;
 	u64 start, end, test_start;
-	u64 found;
+	bool found;
 	int ret = -EINVAL;
 
 	test_msg("running find delalloc tests");
 
 	inode = btrfs_new_test_inode();
 	if (!inode) {
-		test_err("failed to allocate test inode");
+		test_std_err(TEST_ALLOC_INODE);
 		return -ENOMEM;
 	}
+	tmp = &BTRFS_I(inode)->io_tree;
 
-	extent_io_tree_init(&tmp, inode);
+	/*
+	 * Passing NULL as we don't have fs_info but tracepoints are not used
+	 * at this point
+	 */
+	extent_io_tree_init(NULL, tmp, IO_TREE_SELFTEST, NULL);
 
 	/*
 	 * First go through and create and mark all of our pages dirty, we pin
@@ -103,11 +110,11 @@
 	 * |--- delalloc ---|
 	 * |---  search  ---|
 	 */
-	set_extent_delalloc(&tmp, 0, sectorsize - 1, 0, NULL);
+	set_extent_delalloc(tmp, 0, sectorsize - 1, 0, NULL);
 	start = 0;
 	end = 0;
-	found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
-					 &end, max_bytes);
+	found = find_lock_delalloc_range(inode, locked_page, &start,
+					 &end);
 	if (!found) {
 		test_err("should have found at least one delalloc");
 		goto out_bits;
@@ -117,7 +124,7 @@
 			sectorsize - 1, start, end);
 		goto out_bits;
 	}
-	unlock_extent(&tmp, start, end);
+	unlock_extent(tmp, start, end);
 	unlock_page(locked_page);
 	put_page(locked_page);
 
@@ -134,11 +141,11 @@
 		test_err("couldn't find the locked page");
 		goto out_bits;
 	}
-	set_extent_delalloc(&tmp, sectorsize, max_bytes - 1, 0, NULL);
+	set_extent_delalloc(tmp, sectorsize, max_bytes - 1, 0, NULL);
 	start = test_start;
 	end = 0;
-	found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
-					 &end, max_bytes);
+	found = find_lock_delalloc_range(inode, locked_page, &start,
+					 &end);
 	if (!found) {
 		test_err("couldn't find delalloc in our range");
 		goto out_bits;
@@ -153,7 +160,7 @@
 		test_err("there were unlocked pages in the range");
 		goto out_bits;
 	}
-	unlock_extent(&tmp, start, end);
+	unlock_extent(tmp, start, end);
 	/* locked_page was unlocked above */
 	put_page(locked_page);
 
@@ -171,8 +178,8 @@
 	}
 	start = test_start;
 	end = 0;
-	found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
-					 &end, max_bytes);
+	found = find_lock_delalloc_range(inode, locked_page, &start,
+					 &end);
 	if (found) {
 		test_err("found range when we shouldn't have");
 		goto out_bits;
@@ -189,11 +196,11 @@
 	 *
 	 * We are re-using our test_start from above since it works out well.
 	 */
-	set_extent_delalloc(&tmp, max_bytes, total_dirty - 1, 0, NULL);
+	set_extent_delalloc(tmp, max_bytes, total_dirty - 1, 0, NULL);
 	start = test_start;
 	end = 0;
-	found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
-					 &end, max_bytes);
+	found = find_lock_delalloc_range(inode, locked_page, &start,
+					 &end);
 	if (!found) {
 		test_err("didn't find our range");
 		goto out_bits;
@@ -208,7 +215,7 @@
 		test_err("pages in range were not all locked");
 		goto out_bits;
 	}
-	unlock_extent(&tmp, start, end);
+	unlock_extent(tmp, start, end);
 
 	/*
 	 * Now to test where we run into a page that is no longer dirty in the
@@ -233,8 +240,8 @@
 	 * this changes at any point in the future we will need to fix this
 	 * tests expected behavior.
 	 */
-	found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
-					 &end, max_bytes);
+	found = find_lock_delalloc_range(inode, locked_page, &start,
+					 &end);
 	if (!found) {
 		test_err("didn't find our range");
 		goto out_bits;
@@ -251,7 +258,7 @@
 	}
 	ret = 0;
 out_bits:
-	clear_extent_bits(&tmp, 0, total_dirty - 1, (unsigned)-1);
+	clear_extent_bits(tmp, 0, total_dirty - 1, (unsigned)-1);
 out:
 	if (locked_page)
 		put_page(locked_page);
@@ -373,8 +380,8 @@
 {
 	struct btrfs_fs_info *fs_info;
 	unsigned long len;
-	unsigned long *bitmap;
-	struct extent_buffer *eb;
+	unsigned long *bitmap = NULL;
+	struct extent_buffer *eb = NULL;
 	int ret;
 
 	test_msg("running extent buffer bitmap tests");
@@ -387,18 +394,23 @@
 		? sectorsize * 4 : sectorsize;
 
 	fs_info = btrfs_alloc_dummy_fs_info(len, len);
+	if (!fs_info) {
+		test_std_err(TEST_ALLOC_FS_INFO);
+		return -ENOMEM;
+	}
 
 	bitmap = kmalloc(len, GFP_KERNEL);
 	if (!bitmap) {
 		test_err("couldn't allocate test bitmap");
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto out;
 	}
 
 	eb = __alloc_dummy_extent_buffer(fs_info, 0, len);
 	if (!eb) {
-		test_err("couldn't allocate test extent buffer");
-		kfree(bitmap);
-		return -ENOMEM;
+		test_std_err(TEST_ALLOC_ROOT);
+		ret = -ENOMEM;
+		goto out;
 	}
 
 	ret = __test_eb_bitmaps(bitmap, eb, len);
@@ -407,17 +419,118 @@
 
 	/* Do it over again with an extent buffer which isn't page-aligned. */
 	free_extent_buffer(eb);
-	eb = __alloc_dummy_extent_buffer(NULL, nodesize / 2, len);
+	eb = __alloc_dummy_extent_buffer(fs_info, nodesize / 2, len);
 	if (!eb) {
-		test_err("couldn't allocate test extent buffer");
-		kfree(bitmap);
-		return -ENOMEM;
+		test_std_err(TEST_ALLOC_ROOT);
+		ret = -ENOMEM;
+		goto out;
 	}
 
 	ret = __test_eb_bitmaps(bitmap, eb, len);
 out:
 	free_extent_buffer(eb);
 	kfree(bitmap);
+	btrfs_free_dummy_fs_info(fs_info);
+	return ret;
+}
+
+static int test_find_first_clear_extent_bit(void)
+{
+	struct extent_io_tree tree;
+	u64 start, end;
+	int ret = -EINVAL;
+
+	test_msg("running find_first_clear_extent_bit test");
+	extent_io_tree_init(NULL, &tree, IO_TREE_SELFTEST, NULL);
+
+	/*
+	 * Set 1M-4M alloc/discard and 32M-64M thus leaving a hole between
+	 * 4M-32M
+	 */
+	set_extent_bits(&tree, SZ_1M, SZ_4M - 1,
+			CHUNK_TRIMMED | CHUNK_ALLOCATED);
+
+	find_first_clear_extent_bit(&tree, SZ_512K, &start, &end,
+				    CHUNK_TRIMMED | CHUNK_ALLOCATED);
+
+	if (start != 0 || end != SZ_1M - 1) {
+		test_err("error finding beginning range: start %llu end %llu",
+			 start, end);
+		goto out;
+	}
+
+	/* Now add 32M-64M so that we have a hole between 4M-32M */
+	set_extent_bits(&tree, SZ_32M, SZ_64M - 1,
+			CHUNK_TRIMMED | CHUNK_ALLOCATED);
+
+	/*
+	 * Request first hole starting at 12M, we should get 4M-32M
+	 */
+	find_first_clear_extent_bit(&tree, 12 * SZ_1M, &start, &end,
+				    CHUNK_TRIMMED | CHUNK_ALLOCATED);
+
+	if (start != SZ_4M || end != SZ_32M - 1) {
+		test_err("error finding trimmed range: start %llu end %llu",
+			 start, end);
+		goto out;
+	}
+
+	/*
+	 * Search in the middle of allocated range, should get the next one
+	 * available, which happens to be unallocated -> 4M-32M
+	 */
+	find_first_clear_extent_bit(&tree, SZ_2M, &start, &end,
+				    CHUNK_TRIMMED | CHUNK_ALLOCATED);
+
+	if (start != SZ_4M || end != SZ_32M - 1) {
+		test_err("error finding next unalloc range: start %llu end %llu",
+			 start, end);
+		goto out;
+	}
+
+	/*
+	 * Set 64M-72M with CHUNK_ALLOC flag, then search for CHUNK_TRIMMED flag
+	 * being unset in this range, we should get the entry in range 64M-72M
+	 */
+	set_extent_bits(&tree, SZ_64M, SZ_64M + SZ_8M - 1, CHUNK_ALLOCATED);
+	find_first_clear_extent_bit(&tree, SZ_64M + SZ_1M, &start, &end,
+				    CHUNK_TRIMMED);
+
+	if (start != SZ_64M || end != SZ_64M + SZ_8M - 1) {
+		test_err("error finding exact range: start %llu end %llu",
+			 start, end);
+		goto out;
+	}
+
+	find_first_clear_extent_bit(&tree, SZ_64M - SZ_8M, &start, &end,
+				    CHUNK_TRIMMED);
+
+	/*
+	 * Search in the middle of set range whose immediate neighbour doesn't
+	 * have the bits set so it must be returned
+	 */
+	if (start != SZ_64M || end != SZ_64M + SZ_8M - 1) {
+		test_err("error finding next alloc range: start %llu end %llu",
+			 start, end);
+		goto out;
+	}
+
+	/*
+	 * Search beyond any known range, shall return after last known range
+	 * and end should be -1
+	 */
+	find_first_clear_extent_bit(&tree, -1, &start, &end, CHUNK_TRIMMED);
+	if (start != SZ_64M + SZ_8M || end != -1) {
+		test_err(
+		"error handling beyond end of range search: start %llu end %llu",
+			start, end);
+		goto out;
+	}
+
+	ret = 0;
+out:
+	clear_extent_bits(&tree, 0, (u64)-1, CHUNK_TRIMMED | CHUNK_ALLOCATED);
+
 	return ret;
 }
 
@@ -431,8 +544,11 @@
 	if (ret)
 		goto out;
 
+	ret = test_find_first_clear_extent_bit();
+	if (ret)
+		goto out;
+
 	ret = test_eb_bitmaps(sectorsize, nodesize);
 out:
-	test_msg("extent I/O tests finished");
 	return ret;
 }
diff --git a/fs/btrfs/tests/extent-map-tests.c b/fs/btrfs/tests/extent-map-tests.c
index 385a531..4a7f796 100644
--- a/fs/btrfs/tests/extent-map-tests.c
+++ b/fs/btrfs/tests/extent-map-tests.c
@@ -12,8 +12,8 @@
 	struct extent_map *em;
 	struct rb_node *node;
 
-	while (!RB_EMPTY_ROOT(&em_tree->map)) {
-		node = rb_first(&em_tree->map);
+	while (!RB_EMPTY_ROOT(&em_tree->map.rb_root)) {
+		node = rb_first_cached(&em_tree->map);
 		em = rb_entry(node, struct extent_map, rb_node);
 		remove_extent_mapping(em_tree, em);
 
@@ -47,7 +47,7 @@
  *                                    ->add_extent_mapping(0, 16K)
  *                                    -> #handle -EEXIST
  */
-static void test_case_1(struct btrfs_fs_info *fs_info,
+static int test_case_1(struct btrfs_fs_info *fs_info,
 		struct extent_map_tree *em_tree)
 {
 	struct extent_map *em;
@@ -56,55 +56,79 @@
 	int ret;
 
 	em = alloc_extent_map();
-	if (!em)
-		/* Skip the test on error. */
-		return;
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		return -ENOMEM;
+	}
 
 	/* Add [0, 16K) */
 	em->start = 0;
 	em->len = SZ_16K;
 	em->block_start = 0;
 	em->block_len = SZ_16K;
+	write_lock(&em_tree->lock);
 	ret = add_extent_mapping(em_tree, em, 0);
-	ASSERT(ret == 0);
+	write_unlock(&em_tree->lock);
+	if (ret < 0) {
+		test_err("cannot add extent range [0, 16K)");
+		goto out;
+	}
 	free_extent_map(em);
 
 	/* Add [16K, 20K) following [0, 16K)  */
 	em = alloc_extent_map();
-	if (!em)
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		ret = -ENOMEM;
 		goto out;
+	}
 
 	em->start = SZ_16K;
 	em->len = SZ_4K;
 	em->block_start = SZ_32K; /* avoid merging */
 	em->block_len = SZ_4K;
+	write_lock(&em_tree->lock);
 	ret = add_extent_mapping(em_tree, em, 0);
-	ASSERT(ret == 0);
+	write_unlock(&em_tree->lock);
+	if (ret < 0) {
+		test_err("cannot add extent range [16K, 20K)");
+		goto out;
+	}
 	free_extent_map(em);
 
 	em = alloc_extent_map();
-	if (!em)
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		ret = -ENOMEM;
 		goto out;
+	}
 
 	/* Add [0, 8K), should return [0, 16K) instead. */
 	em->start = start;
 	em->len = len;
 	em->block_start = start;
 	em->block_len = len;
+	write_lock(&em_tree->lock);
 	ret = btrfs_add_extent_mapping(fs_info, em_tree, &em, em->start, em->len);
-	if (ret)
+	write_unlock(&em_tree->lock);
+	if (ret) {
 		test_err("case1 [%llu %llu]: ret %d", start, start + len, ret);
+		goto out;
+	}
 	if (em &&
 	    (em->start != 0 || extent_map_end(em) != SZ_16K ||
-	     em->block_start != 0 || em->block_len != SZ_16K))
+	     em->block_start != 0 || em->block_len != SZ_16K)) {
 		test_err(
 "case1 [%llu %llu]: ret %d return a wrong em (start %llu len %llu block_start %llu block_len %llu",
 			 start, start + len, ret, em->start, em->len,
 			 em->block_start, em->block_len);
+		ret = -EINVAL;
+	}
 	free_extent_map(em);
 out:
-	/* free memory */
 	free_extent_map_tree(em_tree);
+
+	return ret;
 }
 
 /*
@@ -113,65 +137,89 @@
  * Reading the inline ending up with EEXIST, ie. read an inline
  * extent and discard page cache and read it again.
  */
-static void test_case_2(struct btrfs_fs_info *fs_info,
+static int test_case_2(struct btrfs_fs_info *fs_info,
 		struct extent_map_tree *em_tree)
 {
 	struct extent_map *em;
 	int ret;
 
 	em = alloc_extent_map();
-	if (!em)
-		/* Skip the test on error. */
-		return;
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		return -ENOMEM;
+	}
 
 	/* Add [0, 1K) */
 	em->start = 0;
 	em->len = SZ_1K;
 	em->block_start = EXTENT_MAP_INLINE;
 	em->block_len = (u64)-1;
+	write_lock(&em_tree->lock);
 	ret = add_extent_mapping(em_tree, em, 0);
-	ASSERT(ret == 0);
+	write_unlock(&em_tree->lock);
+	if (ret < 0) {
+		test_err("cannot add extent range [0, 1K)");
+		goto out;
+	}
 	free_extent_map(em);
 
-	/* Add [4K, 4K) following [0, 1K)  */
+	/* Add [4K, 8K) following [0, 1K)  */
 	em = alloc_extent_map();
-	if (!em)
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		ret = -ENOMEM;
 		goto out;
+	}
 
 	em->start = SZ_4K;
 	em->len = SZ_4K;
 	em->block_start = SZ_4K;
 	em->block_len = SZ_4K;
+	write_lock(&em_tree->lock);
 	ret = add_extent_mapping(em_tree, em, 0);
-	ASSERT(ret == 0);
+	write_unlock(&em_tree->lock);
+	if (ret < 0) {
+		test_err("cannot add extent range [4K, 8K)");
+		goto out;
+	}
 	free_extent_map(em);
 
 	em = alloc_extent_map();
-	if (!em)
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		ret = -ENOMEM;
 		goto out;
+	}
 
 	/* Add [0, 1K) */
 	em->start = 0;
 	em->len = SZ_1K;
 	em->block_start = EXTENT_MAP_INLINE;
 	em->block_len = (u64)-1;
+	write_lock(&em_tree->lock);
 	ret = btrfs_add_extent_mapping(fs_info, em_tree, &em, em->start, em->len);
-	if (ret)
+	write_unlock(&em_tree->lock);
+	if (ret) {
 		test_err("case2 [0 1K]: ret %d", ret);
+		goto out;
+	}
 	if (em &&
 	    (em->start != 0 || extent_map_end(em) != SZ_1K ||
-	     em->block_start != EXTENT_MAP_INLINE || em->block_len != (u64)-1))
+	     em->block_start != EXTENT_MAP_INLINE || em->block_len != (u64)-1)) {
 		test_err(
 "case2 [0 1K]: ret %d return a wrong em (start %llu len %llu block_start %llu block_len %llu",
 			 ret, em->start, em->len, em->block_start,
 			 em->block_len);
+		ret = -EINVAL;
+	}
 	free_extent_map(em);
 out:
-	/* free memory */
 	free_extent_map_tree(em_tree);
+
+	return ret;
 }
 
-static void __test_case_3(struct btrfs_fs_info *fs_info,
+static int __test_case_3(struct btrfs_fs_info *fs_info,
 		struct extent_map_tree *em_tree, u64 start)
 {
 	struct extent_map *em;
@@ -179,47 +227,63 @@
 	int ret;
 
 	em = alloc_extent_map();
-	if (!em)
-		/* Skip this test on error. */
-		return;
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		return -ENOMEM;
+	}
 
 	/* Add [4K, 8K) */
 	em->start = SZ_4K;
 	em->len = SZ_4K;
 	em->block_start = SZ_4K;
 	em->block_len = SZ_4K;
+	write_lock(&em_tree->lock);
 	ret = add_extent_mapping(em_tree, em, 0);
-	ASSERT(ret == 0);
+	write_unlock(&em_tree->lock);
+	if (ret < 0) {
+		test_err("cannot add extent range [4K, 8K)");
+		goto out;
+	}
 	free_extent_map(em);
 
 	em = alloc_extent_map();
-	if (!em)
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		ret = -ENOMEM;
 		goto out;
+	}
 
 	/* Add [0, 16K) */
 	em->start = 0;
 	em->len = SZ_16K;
 	em->block_start = 0;
 	em->block_len = SZ_16K;
+	write_lock(&em_tree->lock);
 	ret = btrfs_add_extent_mapping(fs_info, em_tree, &em, start, len);
-	if (ret)
+	write_unlock(&em_tree->lock);
+	if (ret) {
 		test_err("case3 [0x%llx 0x%llx): ret %d",
 			 start, start + len, ret);
+		goto out;
+	}
 	/*
 	 * Since bytes within em are contiguous, em->block_start is identical to
 	 * em->start.
 	 */
 	if (em &&
 	    (start < em->start || start + len > extent_map_end(em) ||
-	     em->start != em->block_start || em->len != em->block_len))
+	     em->start != em->block_start || em->len != em->block_len)) {
 		test_err(
 "case3 [0x%llx 0x%llx): ret %d em (start 0x%llx len 0x%llx block_start 0x%llx block_len 0x%llx)",
 			 start, start + len, ret, em->start, em->len,
 			 em->block_start, em->block_len);
+		ret = -EINVAL;
+	}
 	free_extent_map(em);
 out:
-	/* free memory */
 	free_extent_map_tree(em_tree);
+
+	return ret;
 }
 
 /*
@@ -238,15 +302,23 @@
  *   -> add_extent_mapping()
  *                            -> add_extent_mapping()
  */
-static void test_case_3(struct btrfs_fs_info *fs_info,
+static int test_case_3(struct btrfs_fs_info *fs_info,
 		struct extent_map_tree *em_tree)
 {
-	__test_case_3(fs_info, em_tree, 0);
-	__test_case_3(fs_info, em_tree, SZ_8K);
-	__test_case_3(fs_info, em_tree, (12 * 1024ULL));
+	int ret;
+
+	ret = __test_case_3(fs_info, em_tree, 0);
+	if (ret)
+		return ret;
+	ret = __test_case_3(fs_info, em_tree, SZ_8K);
+	if (ret)
+		return ret;
+	ret = __test_case_3(fs_info, em_tree, (12 * SZ_1K));
+
+	return ret;
 }
 
-static void __test_case_4(struct btrfs_fs_info *fs_info,
+static int __test_case_4(struct btrfs_fs_info *fs_info,
 		struct extent_map_tree *em_tree, u64 start)
 {
 	struct extent_map *em;
@@ -254,54 +326,77 @@
 	int ret;
 
 	em = alloc_extent_map();
-	if (!em)
-		/* Skip this test on error. */
-		return;
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		return -ENOMEM;
+	}
 
 	/* Add [0K, 8K) */
 	em->start = 0;
 	em->len = SZ_8K;
 	em->block_start = 0;
 	em->block_len = SZ_8K;
+	write_lock(&em_tree->lock);
 	ret = add_extent_mapping(em_tree, em, 0);
-	ASSERT(ret == 0);
+	write_unlock(&em_tree->lock);
+	if (ret < 0) {
+		test_err("cannot add extent range [0, 8K)");
+		goto out;
+	}
 	free_extent_map(em);
 
 	em = alloc_extent_map();
-	if (!em)
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		ret = -ENOMEM;
 		goto out;
+	}
 
-	/* Add [8K, 24K) */
+	/* Add [8K, 32K) */
 	em->start = SZ_8K;
-	em->len = 24 * 1024ULL;
+	em->len = 24 * SZ_1K;
 	em->block_start = SZ_16K; /* avoid merging */
-	em->block_len = 24 * 1024ULL;
+	em->block_len = 24 * SZ_1K;
+	write_lock(&em_tree->lock);
 	ret = add_extent_mapping(em_tree, em, 0);
-	ASSERT(ret == 0);
+	write_unlock(&em_tree->lock);
+	if (ret < 0) {
+		test_err("cannot add extent range [8K, 32K)");
+		goto out;
+	}
 	free_extent_map(em);
 
 	em = alloc_extent_map();
-	if (!em)
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		ret = -ENOMEM;
 		goto out;
+	}
 	/* Add [0K, 32K) */
 	em->start = 0;
 	em->len = SZ_32K;
 	em->block_start = 0;
 	em->block_len = SZ_32K;
+	write_lock(&em_tree->lock);
 	ret = btrfs_add_extent_mapping(fs_info, em_tree, &em, start, len);
-	if (ret)
+	write_unlock(&em_tree->lock);
+	if (ret) {
 		test_err("case4 [0x%llx 0x%llx): ret %d",
 			 start, len, ret);
-	if (em &&
-	    (start < em->start || start + len > extent_map_end(em)))
+		goto out;
+	}
+	if (em && (start < em->start || start + len > extent_map_end(em))) {
 		test_err(
 "case4 [0x%llx 0x%llx): ret %d, added wrong em (start 0x%llx len 0x%llx block_start 0x%llx block_len 0x%llx)",
 			 start, len, ret, em->start, em->len, em->block_start,
 			 em->block_len);
+		ret = -EINVAL;
+	}
 	free_extent_map(em);
 out:
-	/* free memory */
 	free_extent_map_tree(em_tree);
+
+	return ret;
 }
 
 /*
@@ -329,17 +424,24 @@
  *                                             # handle -EEXIST when adding
  *                                             # [0, 32K)
  */
-static void test_case_4(struct btrfs_fs_info *fs_info,
+static int test_case_4(struct btrfs_fs_info *fs_info,
 		struct extent_map_tree *em_tree)
 {
-	__test_case_4(fs_info, em_tree, 0);
-	__test_case_4(fs_info, em_tree, SZ_4K);
+	int ret;
+
+	ret = __test_case_4(fs_info, em_tree, 0);
+	if (ret)
+		return ret;
+	ret = __test_case_4(fs_info, em_tree, SZ_4K);
+
+	return ret;
 }
 
 int btrfs_test_extent_map(void)
 {
 	struct btrfs_fs_info *fs_info = NULL;
 	struct extent_map_tree *em_tree;
+	int ret = 0;
 
 	test_msg("running extent_map tests");
 
@@ -349,25 +451,32 @@
 	 */
 	fs_info = btrfs_alloc_dummy_fs_info(PAGE_SIZE, PAGE_SIZE);
 	if (!fs_info) {
-		test_msg("Couldn't allocate dummy fs info");
+		test_std_err(TEST_ALLOC_FS_INFO);
 		return -ENOMEM;
 	}
 
 	em_tree = kzalloc(sizeof(*em_tree), GFP_KERNEL);
-	if (!em_tree)
-		/* Skip the test on error. */
+	if (!em_tree) {
+		ret = -ENOMEM;
 		goto out;
+	}
 
 	extent_map_tree_init(em_tree);
 
-	test_case_1(fs_info, em_tree);
-	test_case_2(fs_info, em_tree);
-	test_case_3(fs_info, em_tree);
-	test_case_4(fs_info, em_tree);
+	ret = test_case_1(fs_info, em_tree);
+	if (ret)
+		goto out;
+	ret = test_case_2(fs_info, em_tree);
+	if (ret)
+		goto out;
+	ret = test_case_3(fs_info, em_tree);
+	if (ret)
+		goto out;
+	ret = test_case_4(fs_info, em_tree);
 
-	kfree(em_tree);
 out:
+	kfree(em_tree);
 	btrfs_free_dummy_fs_info(fs_info);
 
-	return 0;
+	return ret;
 }
diff --git a/fs/btrfs/tests/free-space-tests.c b/fs/btrfs/tests/free-space-tests.c
index 5c2f77e..43ec706 100644
--- a/fs/btrfs/tests/free-space-tests.c
+++ b/fs/btrfs/tests/free-space-tests.c
@@ -8,6 +8,7 @@
 #include "../ctree.h"
 #include "../disk-io.h"
 #include "../free-space-cache.h"
+#include "../block-group.h"
 
 #define BITS_PER_BITMAP		(PAGE_SIZE * 8UL)
 
@@ -404,7 +405,7 @@
 	};
 	const struct btrfs_free_space_op *orig_free_space_ops;
 
-	test_msg("running space stealing from bitmap to extent");
+	test_msg("running space stealing from bitmap to extent tests");
 
 	/*
 	 * For this test, we want to ensure we end up with an extent entry
@@ -834,9 +835,10 @@
 
 	test_msg("running btrfs free space cache tests");
 	fs_info = btrfs_alloc_dummy_fs_info(nodesize, sectorsize);
-	if (!fs_info)
+	if (!fs_info) {
+		test_std_err(TEST_ALLOC_FS_INFO);
 		return -ENOMEM;
-
+	}
 
 	/*
 	 * For ppc64 (with 64k page size), bytes per bitmap might be
@@ -846,13 +848,14 @@
 	cache = btrfs_alloc_dummy_block_group(fs_info,
 				      BITS_PER_BITMAP * sectorsize + PAGE_SIZE);
 	if (!cache) {
-		test_err("couldn't run the tests");
+		test_std_err(TEST_ALLOC_BLOCK_GROUP);
 		btrfs_free_dummy_fs_info(fs_info);
 		return 0;
 	}
 
 	root = btrfs_alloc_dummy_root(fs_info);
 	if (IS_ERR(root)) {
+		test_std_err(TEST_ALLOC_ROOT);
 		ret = PTR_ERR(root);
 		goto out;
 	}
@@ -874,6 +877,5 @@
 	btrfs_free_dummy_block_group(cache);
 	btrfs_free_dummy_root(root);
 	btrfs_free_dummy_fs_info(fs_info);
-	test_msg("free space cache tests finished");
 	return ret;
 }
diff --git a/fs/btrfs/tests/free-space-tree-tests.c b/fs/btrfs/tests/free-space-tree-tests.c
index 89346da..bc92df9 100644
--- a/fs/btrfs/tests/free-space-tree-tests.c
+++ b/fs/btrfs/tests/free-space-tree-tests.c
@@ -9,6 +9,7 @@
 #include "../disk-io.h"
 #include "../free-space-tree.h"
 #include "../transaction.h"
+#include "../block-group.h"
 
 struct free_space_extent {
 	u64 start;
@@ -30,7 +31,7 @@
 	unsigned int i;
 	int ret;
 
-	info = search_free_space_info(trans, fs_info, cache, path, 0);
+	info = search_free_space_info(trans, cache, path, 0);
 	if (IS_ERR(info)) {
 		test_err("could not find free space info");
 		ret = PTR_ERR(info);
@@ -115,7 +116,7 @@
 	u32 flags;
 	int ret;
 
-	info = search_free_space_info(trans, fs_info, cache, path, 0);
+	info = search_free_space_info(trans, cache, path, 0);
 	if (IS_ERR(info)) {
 		test_err("could not find free space info");
 		btrfs_release_path(path);
@@ -444,14 +445,14 @@
 
 	fs_info = btrfs_alloc_dummy_fs_info(nodesize, sectorsize);
 	if (!fs_info) {
-		test_err("couldn't allocate dummy fs info");
+		test_std_err(TEST_ALLOC_FS_INFO);
 		ret = -ENOMEM;
 		goto out;
 	}
 
 	root = btrfs_alloc_dummy_root(fs_info);
 	if (IS_ERR(root)) {
-		test_err("couldn't allocate dummy root");
+		test_std_err(TEST_ALLOC_ROOT);
 		ret = PTR_ERR(root);
 		goto out;
 	}
@@ -463,7 +464,7 @@
 
 	root->node = alloc_test_extent_buffer(root->fs_info, nodesize);
 	if (!root->node) {
-		test_err("couldn't allocate dummy buffer");
+		test_std_err(TEST_ALLOC_EXTENT_BUFFER);
 		ret = -ENOMEM;
 		goto out;
 	}
@@ -473,7 +474,7 @@
 
 	cache = btrfs_alloc_dummy_block_group(fs_info, 8 * alignment);
 	if (!cache) {
-		test_err("couldn't allocate dummy block group cache");
+		test_std_err(TEST_ALLOC_BLOCK_GROUP);
 		ret = -ENOMEM;
 		goto out;
 	}
@@ -486,7 +487,7 @@
 
 	path = btrfs_alloc_path();
 	if (!path) {
-		test_err("couldn't allocate path");
+		test_std_err(TEST_ALLOC_ROOT);
 		ret = -ENOMEM;
 		goto out;
 	}
@@ -539,7 +540,7 @@
 	ret = run_test(test_func, 0, sectorsize, nodesize, alignment);
 	if (ret) {
 		test_err(
-	"%pf failed with extents, sectorsize=%u, nodesize=%u, alignment=%u",
+	"%ps failed with extents, sectorsize=%u, nodesize=%u, alignment=%u",
 			 test_func, sectorsize, nodesize, alignment);
 		test_ret = ret;
 	}
@@ -547,7 +548,7 @@
 	ret = run_test(test_func, 1, sectorsize, nodesize, alignment);
 	if (ret) {
 		test_err(
-	"%pf failed with bitmaps, sectorsize=%u, nodesize=%u, alignment=%u",
+	"%ps failed with bitmaps, sectorsize=%u, nodesize=%u, alignment=%u",
 			 test_func, sectorsize, nodesize, alignment);
 		test_ret = ret;
 	}
diff --git a/fs/btrfs/tests/inode-tests.c b/fs/btrfs/tests/inode-tests.c
index 64043f0..09ecf7d 100644
--- a/fs/btrfs/tests/inode-tests.c
+++ b/fs/btrfs/tests/inode-tests.c
@@ -226,39 +226,37 @@
 	u64 offset;
 	int ret = -ENOMEM;
 
+	test_msg("running btrfs_get_extent tests");
+
 	inode = btrfs_new_test_inode();
 	if (!inode) {
-		test_err("couldn't allocate inode");
+		test_std_err(TEST_ALLOC_INODE);
 		return ret;
 	}
 
+	inode->i_mode = S_IFREG;
 	BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
 	BTRFS_I(inode)->location.objectid = BTRFS_FIRST_FREE_OBJECTID;
 	BTRFS_I(inode)->location.offset = 0;
 
 	fs_info = btrfs_alloc_dummy_fs_info(nodesize, sectorsize);
 	if (!fs_info) {
-		test_err("couldn't allocate dummy fs info");
+		test_std_err(TEST_ALLOC_FS_INFO);
 		goto out;
 	}
 
 	root = btrfs_alloc_dummy_root(fs_info);
 	if (IS_ERR(root)) {
-		test_err("couldn't allocate root");
+		test_std_err(TEST_ALLOC_ROOT);
 		goto out;
 	}
 
 	root->node = alloc_dummy_extent_buffer(fs_info, nodesize);
 	if (!root->node) {
-		test_err("couldn't allocate dummy buffer");
+		test_std_err(TEST_ALLOC_ROOT);
 		goto out;
 	}
 
-	/*
-	 * We will just free a dummy node if it's ref count is 2 so we need an
-	 * extra ref so our searches don't accidentally release our page.
-	 */
-	extent_buffer_get(root->node);
 	btrfs_set_header_nritems(root->node, 0);
 	btrfs_set_header_level(root->node, 0);
 	ret = -EINVAL;
@@ -832,9 +830,11 @@
 	struct extent_map *em = NULL;
 	int ret = -ENOMEM;
 
+	test_msg("running hole first btrfs_get_extent test");
+
 	inode = btrfs_new_test_inode();
 	if (!inode) {
-		test_err("couldn't allocate inode");
+		test_std_err(TEST_ALLOC_INODE);
 		return ret;
 	}
 
@@ -844,23 +844,22 @@
 
 	fs_info = btrfs_alloc_dummy_fs_info(nodesize, sectorsize);
 	if (!fs_info) {
-		test_err("couldn't allocate dummy fs info");
+		test_std_err(TEST_ALLOC_FS_INFO);
 		goto out;
 	}
 
 	root = btrfs_alloc_dummy_root(fs_info);
 	if (IS_ERR(root)) {
-		test_err("couldn't allocate root");
+		test_std_err(TEST_ALLOC_ROOT);
 		goto out;
 	}
 
 	root->node = alloc_dummy_extent_buffer(fs_info, nodesize);
 	if (!root->node) {
-		test_err("couldn't allocate dummy buffer");
+		test_std_err(TEST_ALLOC_ROOT);
 		goto out;
 	}
 
-	extent_buffer_get(root->node);
 	btrfs_set_header_nritems(root->node, 0);
 	btrfs_set_header_level(root->node, 0);
 	BTRFS_I(inode)->root = root;
@@ -933,21 +932,23 @@
 	struct btrfs_root *root = NULL;
 	int ret = -ENOMEM;
 
+	test_msg("running outstanding_extents tests");
+
 	inode = btrfs_new_test_inode();
 	if (!inode) {
-		test_err("couldn't allocate inode");
+		test_std_err(TEST_ALLOC_INODE);
 		return ret;
 	}
 
 	fs_info = btrfs_alloc_dummy_fs_info(nodesize, sectorsize);
 	if (!fs_info) {
-		test_err("couldn't allocate dummy fs info");
+		test_std_err(TEST_ALLOC_FS_INFO);
 		goto out;
 	}
 
 	root = btrfs_alloc_dummy_root(fs_info);
 	if (IS_ERR(root)) {
-		test_err("couldn't allocate root");
+		test_std_err(TEST_ALLOC_ROOT);
 		goto out;
 	}
 
@@ -956,7 +957,7 @@
 
 	/* [BTRFS_MAX_EXTENT_SIZE] */
 	ret = btrfs_set_extent_delalloc(inode, 0, BTRFS_MAX_EXTENT_SIZE - 1, 0,
-					NULL, 0);
+					NULL);
 	if (ret) {
 		test_err("btrfs_set_extent_delalloc returned %d", ret);
 		goto out;
@@ -971,7 +972,7 @@
 	/* [BTRFS_MAX_EXTENT_SIZE][sectorsize] */
 	ret = btrfs_set_extent_delalloc(inode, BTRFS_MAX_EXTENT_SIZE,
 					BTRFS_MAX_EXTENT_SIZE + sectorsize - 1,
-					0, NULL, 0);
+					0, NULL);
 	if (ret) {
 		test_err("btrfs_set_extent_delalloc returned %d", ret);
 		goto out;
@@ -987,8 +988,7 @@
 	ret = clear_extent_bit(&BTRFS_I(inode)->io_tree,
 			       BTRFS_MAX_EXTENT_SIZE >> 1,
 			       (BTRFS_MAX_EXTENT_SIZE >> 1) + sectorsize - 1,
-			       EXTENT_DELALLOC | EXTENT_DIRTY |
-			       EXTENT_UPTODATE, 0, 0, NULL);
+			       EXTENT_DELALLOC | EXTENT_UPTODATE, 0, 0, NULL);
 	if (ret) {
 		test_err("clear_extent_bit returned %d", ret);
 		goto out;
@@ -1004,7 +1004,7 @@
 	ret = btrfs_set_extent_delalloc(inode, BTRFS_MAX_EXTENT_SIZE >> 1,
 					(BTRFS_MAX_EXTENT_SIZE >> 1)
 					+ sectorsize - 1,
-					0, NULL, 0);
+					0, NULL);
 	if (ret) {
 		test_err("btrfs_set_extent_delalloc returned %d", ret);
 		goto out;
@@ -1022,7 +1022,7 @@
 	ret = btrfs_set_extent_delalloc(inode,
 			BTRFS_MAX_EXTENT_SIZE + 2 * sectorsize,
 			(BTRFS_MAX_EXTENT_SIZE << 1) + 3 * sectorsize - 1,
-			0, NULL, 0);
+			0, NULL);
 	if (ret) {
 		test_err("btrfs_set_extent_delalloc returned %d", ret);
 		goto out;
@@ -1039,7 +1039,7 @@
 	*/
 	ret = btrfs_set_extent_delalloc(inode,
 			BTRFS_MAX_EXTENT_SIZE + sectorsize,
-			BTRFS_MAX_EXTENT_SIZE + 2 * sectorsize - 1, 0, NULL, 0);
+			BTRFS_MAX_EXTENT_SIZE + 2 * sectorsize - 1, 0, NULL);
 	if (ret) {
 		test_err("btrfs_set_extent_delalloc returned %d", ret);
 		goto out;
@@ -1055,8 +1055,7 @@
 	ret = clear_extent_bit(&BTRFS_I(inode)->io_tree,
 			       BTRFS_MAX_EXTENT_SIZE + sectorsize,
 			       BTRFS_MAX_EXTENT_SIZE + 2 * sectorsize - 1,
-			       EXTENT_DIRTY | EXTENT_DELALLOC |
-			       EXTENT_UPTODATE, 0, 0, NULL);
+			       EXTENT_DELALLOC | EXTENT_UPTODATE, 0, 0, NULL);
 	if (ret) {
 		test_err("clear_extent_bit returned %d", ret);
 		goto out;
@@ -1074,7 +1073,7 @@
 	 */
 	ret = btrfs_set_extent_delalloc(inode,
 			BTRFS_MAX_EXTENT_SIZE + sectorsize,
-			BTRFS_MAX_EXTENT_SIZE + 2 * sectorsize - 1, 0, NULL, 0);
+			BTRFS_MAX_EXTENT_SIZE + 2 * sectorsize - 1, 0, NULL);
 	if (ret) {
 		test_err("btrfs_set_extent_delalloc returned %d", ret);
 		goto out;
@@ -1088,8 +1087,7 @@
 
 	/* Empty */
 	ret = clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, (u64)-1,
-			       EXTENT_DIRTY | EXTENT_DELALLOC |
-			       EXTENT_UPTODATE, 0, 0, NULL);
+			       EXTENT_DELALLOC | EXTENT_UPTODATE, 0, 0, NULL);
 	if (ret) {
 		test_err("clear_extent_bit returned %d", ret);
 		goto out;
@@ -1104,8 +1102,7 @@
 out:
 	if (ret)
 		clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, (u64)-1,
-				 EXTENT_DIRTY | EXTENT_DELALLOC |
-				 EXTENT_UPTODATE, 0, 0, NULL);
+				 EXTENT_DELALLOC | EXTENT_UPTODATE, 0, 0, NULL);
 	iput(inode);
 	btrfs_free_dummy_root(root);
 	btrfs_free_dummy_fs_info(fs_info);
@@ -1116,17 +1113,16 @@
 {
 	int ret;
 
+	test_msg("running inode tests");
+
 	set_bit(EXTENT_FLAG_COMPRESSED, &compressed_only);
 	set_bit(EXTENT_FLAG_PREALLOC, &prealloc_only);
 
-	test_msg("running btrfs_get_extent tests");
 	ret = test_btrfs_get_extent(sectorsize, nodesize);
 	if (ret)
 		return ret;
-	test_msg("running hole first btrfs_get_extent test");
 	ret = test_hole_first(sectorsize, nodesize);
 	if (ret)
 		return ret;
-	test_msg("running outstanding_extents tests");
 	return test_extent_accounting(sectorsize, nodesize);
 }
diff --git a/fs/btrfs/tests/qgroup-tests.c b/fs/btrfs/tests/qgroup-tests.c
index 412b910..09aaca1 100644
--- a/fs/btrfs/tests/qgroup-tests.c
+++ b/fs/btrfs/tests/qgroup-tests.c
@@ -32,7 +32,7 @@
 
 	path = btrfs_alloc_path();
 	if (!path) {
-		test_err("couldn't allocate path");
+		test_std_err(TEST_ALLOC_ROOT);
 		return -ENOMEM;
 	}
 
@@ -82,7 +82,7 @@
 
 	path = btrfs_alloc_path();
 	if (!path) {
-		test_err("couldn't allocate path");
+		test_std_err(TEST_ALLOC_ROOT);
 		return -ENOMEM;
 	}
 
@@ -132,7 +132,7 @@
 
 	path = btrfs_alloc_path();
 	if (!path) {
-		test_err("couldn't allocate path");
+		test_std_err(TEST_ALLOC_ROOT);
 		return -ENOMEM;
 	}
 	path->leave_spinning = 1;
@@ -166,7 +166,7 @@
 
 	path = btrfs_alloc_path();
 	if (!path) {
-		test_err("couldn't allocate path");
+		test_std_err(TEST_ALLOC_ROOT);
 		return -ENOMEM;
 	}
 
@@ -215,7 +215,7 @@
 
 	btrfs_init_dummy_trans(&trans, fs_info);
 
-	test_msg("qgroup basic add");
+	test_msg("running qgroup add/remove tests");
 	ret = btrfs_create_qgroup(&trans, BTRFS_FS_TREE_OBJECTID);
 	if (ret) {
 		test_err("couldn't create a qgroup %d", ret);
@@ -316,7 +316,7 @@
 
 	btrfs_init_dummy_trans(&trans, fs_info);
 
-	test_msg("qgroup multiple refs test");
+	test_msg("running qgroup multiple refs test");
 
 	/*
 	 * We have BTRFS_FS_TREE_OBJECTID created already from the
@@ -457,13 +457,13 @@
 
 	fs_info = btrfs_alloc_dummy_fs_info(nodesize, sectorsize);
 	if (!fs_info) {
-		test_err("couldn't allocate dummy fs info");
+		test_std_err(TEST_ALLOC_FS_INFO);
 		return -ENOMEM;
 	}
 
 	root = btrfs_alloc_dummy_root(fs_info);
 	if (IS_ERR(root)) {
-		test_err("couldn't allocate root");
+		test_std_err(TEST_ALLOC_ROOT);
 		ret = PTR_ERR(root);
 		goto out;
 	}
@@ -495,7 +495,7 @@
 
 	tmp_root = btrfs_alloc_dummy_root(fs_info);
 	if (IS_ERR(tmp_root)) {
-		test_err("couldn't allocate a fs root");
+		test_std_err(TEST_ALLOC_ROOT);
 		ret = PTR_ERR(tmp_root);
 		goto out;
 	}
@@ -510,7 +510,7 @@
 
 	tmp_root = btrfs_alloc_dummy_root(fs_info);
 	if (IS_ERR(tmp_root)) {
-		test_err("couldn't allocate a fs root");
+		test_std_err(TEST_ALLOC_ROOT);
 		ret = PTR_ERR(tmp_root);
 		goto out;
 	}
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index bb8f6c0..8624bde 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -10,6 +10,7 @@
 #include <linux/pagemap.h>
 #include <linux/blkdev.h>
 #include <linux/uuid.h>
+#include "misc.h"
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -19,6 +20,7 @@
 #include "volumes.h"
 #include "dev-replace.h"
 #include "qgroup.h"
+#include "block-group.h"
 
 #define BTRFS_ROOT_TRANS_TAG 0
 
@@ -28,15 +30,18 @@
 	[TRANS_STATE_COMMIT_START]	= (__TRANS_START | __TRANS_ATTACH),
 	[TRANS_STATE_COMMIT_DOING]	= (__TRANS_START |
 					   __TRANS_ATTACH |
-					   __TRANS_JOIN),
+					   __TRANS_JOIN |
+					   __TRANS_JOIN_NOSTART),
 	[TRANS_STATE_UNBLOCKED]		= (__TRANS_START |
 					   __TRANS_ATTACH |
 					   __TRANS_JOIN |
-					   __TRANS_JOIN_NOLOCK),
+					   __TRANS_JOIN_NOLOCK |
+					   __TRANS_JOIN_NOSTART),
 	[TRANS_STATE_COMPLETED]		= (__TRANS_START |
 					   __TRANS_ATTACH |
 					   __TRANS_JOIN |
-					   __TRANS_JOIN_NOLOCK),
+					   __TRANS_JOIN_NOLOCK |
+					   __TRANS_JOIN_NOSTART),
 };
 
 void btrfs_put_transaction(struct btrfs_transaction *transaction)
@@ -44,19 +49,12 @@
 	WARN_ON(refcount_read(&transaction->use_count) == 0);
 	if (refcount_dec_and_test(&transaction->use_count)) {
 		BUG_ON(!list_empty(&transaction->list));
-		WARN_ON(!RB_EMPTY_ROOT(&transaction->delayed_refs.href_root));
+		WARN_ON(!RB_EMPTY_ROOT(
+				&transaction->delayed_refs.href_root.rb_root));
 		if (transaction->delayed_refs.pending_csums)
 			btrfs_err(transaction->fs_info,
 				  "pending csums is %llu",
 				  transaction->delayed_refs.pending_csums);
-		while (!list_empty(&transaction->pending_chunks)) {
-			struct extent_map *em;
-
-			em = list_first_entry(&transaction->pending_chunks,
-					      struct extent_map, list);
-			list_del_init(&em->list);
-			free_extent_map(em);
-		}
 		/*
 		 * If any block groups are found in ->deleted_bgs then it's
 		 * because the transaction was aborted and a commit did not
@@ -74,39 +72,11 @@
 			btrfs_put_block_group_trimming(cache);
 			btrfs_put_block_group(cache);
 		}
+		WARN_ON(!list_empty(&transaction->dev_update_list));
 		kfree(transaction);
 	}
 }
 
-static void clear_btree_io_tree(struct extent_io_tree *tree)
-{
-	spin_lock(&tree->lock);
-	/*
-	 * Do a single barrier for the waitqueue_active check here, the state
-	 * of the waitqueue should not change once clear_btree_io_tree is
-	 * called.
-	 */
-	smp_mb();
-	while (!RB_EMPTY_ROOT(&tree->state)) {
-		struct rb_node *node;
-		struct extent_state *state;
-
-		node = rb_first(&tree->state);
-		state = rb_entry(node, struct extent_state, rb_node);
-		rb_erase(&state->rb_node, &tree->state);
-		RB_CLEAR_NODE(&state->rb_node);
-		/*
-		 * btree io trees aren't supposed to have tasks waiting for
-		 * changes in the flags of extent states ever.
-		 */
-		ASSERT(!waitqueue_active(&state->wq));
-		free_extent_state(state);
-
-		cond_resched_lock(&tree->lock);
-	}
-	spin_unlock(&tree->lock);
-}
-
 static noinline void switch_commit_roots(struct btrfs_transaction *trans)
 {
 	struct btrfs_fs_info *fs_info = trans->fs_info;
@@ -118,9 +88,10 @@
 		list_del_init(&root->dirty_list);
 		free_extent_buffer(root->commit_root);
 		root->commit_root = btrfs_root_node(root);
-		if (is_fstree(root->objectid))
+		if (is_fstree(root->root_key.objectid))
 			btrfs_unpin_free_ino(root);
-		clear_btree_io_tree(&root->dirty_log_pages);
+		extent_io_tree_release(&root->dirty_log_pages);
+		btrfs_qgroup_clean_swapped_blocks(root);
 	}
 
 	/* We can free old roots now. */
@@ -163,6 +134,24 @@
 }
 
 /*
+ * To be called after all the new block groups attached to the transaction
+ * handle have been created (btrfs_create_pending_block_groups()).
+ */
+void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+
+	if (!trans->chunk_bytes_reserved)
+		return;
+
+	WARN_ON_ONCE(!list_empty(&trans->new_bgs));
+
+	btrfs_block_rsv_release(fs_info, &fs_info->chunk_block_rsv,
+				trans->chunk_bytes_reserved);
+	trans->chunk_bytes_reserved = 0;
+}
+
+/*
  * either allocate a new transaction or hop into the existing one
  */
 static noinline int join_transaction(struct btrfs_fs_info *fs_info,
@@ -232,20 +221,18 @@
 	extwriter_counter_init(cur_trans, type);
 	init_waitqueue_head(&cur_trans->writer_wait);
 	init_waitqueue_head(&cur_trans->commit_wait);
-	init_waitqueue_head(&cur_trans->pending_wait);
 	cur_trans->state = TRANS_STATE_RUNNING;
 	/*
 	 * One for this trans handle, one so it will live on until we
 	 * commit the transaction.
 	 */
 	refcount_set(&cur_trans->use_count, 2);
-	atomic_set(&cur_trans->pending_ordered, 0);
 	cur_trans->flags = 0;
 	cur_trans->start_time = ktime_get_seconds();
 
 	memset(&cur_trans->delayed_refs, 0, sizeof(cur_trans->delayed_refs));
 
-	cur_trans->delayed_refs.href_root = RB_ROOT;
+	cur_trans->delayed_refs.href_root = RB_ROOT_CACHED;
 	cur_trans->delayed_refs.dirty_extent_root = RB_ROOT;
 	atomic_set(&cur_trans->delayed_refs.num_entries, 0);
 
@@ -263,19 +250,18 @@
 	spin_lock_init(&cur_trans->delayed_refs.lock);
 
 	INIT_LIST_HEAD(&cur_trans->pending_snapshots);
-	INIT_LIST_HEAD(&cur_trans->pending_chunks);
+	INIT_LIST_HEAD(&cur_trans->dev_update_list);
 	INIT_LIST_HEAD(&cur_trans->switch_commits);
 	INIT_LIST_HEAD(&cur_trans->dirty_bgs);
 	INIT_LIST_HEAD(&cur_trans->io_bgs);
 	INIT_LIST_HEAD(&cur_trans->dropped_roots);
 	mutex_init(&cur_trans->cache_write_mutex);
-	cur_trans->num_dirty_bgs = 0;
 	spin_lock_init(&cur_trans->dirty_bgs_lock);
 	INIT_LIST_HEAD(&cur_trans->deleted_bgs);
 	spin_lock_init(&cur_trans->dropped_roots_lock);
 	list_add_tail(&cur_trans->list, &fs_info->trans_list);
-	extent_io_tree_init(&cur_trans->dirty_pages,
-			     fs_info->btree_inode);
+	extent_io_tree_init(fs_info, &cur_trans->dirty_pages,
+			IO_TREE_TRANS_DIRTY_PAGES, fs_info->btree_inode);
 	fs_info->generation++;
 	cur_trans->transid = fs_info->generation;
 	fs_info->running_transaction = cur_trans;
@@ -455,7 +441,7 @@
 		  bool enforce_qgroups)
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
-
+	struct btrfs_block_rsv *delayed_refs_rsv = &fs_info->delayed_refs_rsv;
 	struct btrfs_trans_handle *h;
 	struct btrfs_transaction *cur_trans;
 	u64 num_bytes = 0;
@@ -484,13 +470,28 @@
 	 * the appropriate flushing if need be.
 	 */
 	if (num_items && root != fs_info->chunk_root) {
+		struct btrfs_block_rsv *rsv = &fs_info->trans_block_rsv;
+		u64 delayed_refs_bytes = 0;
+
 		qgroup_reserved = num_items * fs_info->nodesize;
 		ret = btrfs_qgroup_reserve_meta_pertrans(root, qgroup_reserved,
 				enforce_qgroups);
 		if (ret)
 			return ERR_PTR(ret);
 
-		num_bytes = btrfs_calc_trans_metadata_size(fs_info, num_items);
+		/*
+		 * We want to reserve all the bytes we may need all at once, so
+		 * we only do 1 enospc flushing cycle per transaction start.  We
+		 * accomplish this by simply assuming we'll do 2 x num_items
+		 * worth of delayed refs updates in this trans handle, and
+		 * refill that amount for whatever is missing in the reserve.
+		 */
+		num_bytes = btrfs_calc_insert_metadata_size(fs_info, num_items);
+		if (delayed_refs_rsv->full == 0) {
+			delayed_refs_bytes = num_bytes;
+			num_bytes <<= 1;
+		}
+
 		/*
 		 * Do the reservation for the relocation root creation
 		 */
@@ -499,8 +500,24 @@
 			reloc_reserved = true;
 		}
 
-		ret = btrfs_block_rsv_add(root, &fs_info->trans_block_rsv,
-					  num_bytes, flush);
+		ret = btrfs_block_rsv_add(root, rsv, num_bytes, flush);
+		if (ret)
+			goto reserve_fail;
+		if (delayed_refs_bytes) {
+			btrfs_migrate_to_delayed_refs_rsv(fs_info, rsv,
+							  delayed_refs_bytes);
+			num_bytes -= delayed_refs_bytes;
+		}
+	} else if (num_items == 0 && flush == BTRFS_RESERVE_FLUSH_ALL &&
+		   !delayed_refs_rsv->full) {
+		/*
+		 * Some people call with btrfs_start_transaction(root, 0)
+		 * because they can be throttled, but have some other mechanism
+		 * for reserving space.  We still want these guys to refill the
+		 * delayed block_rsv so just add 1 items worth of reservation
+		 * here.
+		 */
+		ret = btrfs_delayed_refs_rsv_refill(fs_info, flush);
 		if (ret)
 			goto reserve_fail;
 	}
@@ -531,7 +548,8 @@
 		ret = join_transaction(fs_info, type);
 		if (ret == -EBUSY) {
 			wait_current_trans(fs_info);
-			if (unlikely(type == TRANS_ATTACH))
+			if (unlikely(type == TRANS_ATTACH ||
+				     type == TRANS_JOIN_NOSTART))
 				ret = -ENOENT;
 		}
 	} while (ret == -EBUSY);
@@ -619,7 +637,7 @@
 	if (IS_ERR(trans))
 		return trans;
 
-	num_bytes = btrfs_calc_trans_metadata_size(fs_info, num_items);
+	num_bytes = btrfs_calc_insert_metadata_size(fs_info, num_items);
 	ret = btrfs_cond_migrate_bytes(fs_info, &fs_info->trans_block_rsv,
 				       num_bytes, min_factor);
 	if (ret) {
@@ -648,6 +666,16 @@
 }
 
 /*
+ * Similar to regular join but it never starts a transaction when none is
+ * running or after waiting for the current one to finish.
+ */
+struct btrfs_trans_handle *btrfs_join_transaction_nostart(struct btrfs_root *root)
+{
+	return start_transaction(root, 0, TRANS_JOIN_NOSTART,
+				 BTRFS_RESERVE_NO_FLUSH, true);
+}
+
+/*
  * btrfs_attach_transaction() - catch the running transaction
  *
  * It is used when we want to commit the current the transaction, but
@@ -669,7 +697,7 @@
 /*
  * btrfs_attach_transaction_barrier() - catch the running transaction
  *
- * It is similar to the above function, the differentia is this one
+ * It is similar to the above function, the difference is this one
  * will wait for all the inactive transactions until they fully
  * complete.
  */
@@ -759,7 +787,7 @@
 {
 	struct btrfs_fs_info *fs_info = trans->fs_info;
 
-	if (btrfs_check_space_for_delayed_refs(trans, fs_info))
+	if (btrfs_check_space_for_delayed_refs(fs_info))
 		return 1;
 
 	return !!btrfs_block_rsv_check(&fs_info->global_block_rsv, 5);
@@ -768,22 +796,12 @@
 int btrfs_should_end_transaction(struct btrfs_trans_handle *trans)
 {
 	struct btrfs_transaction *cur_trans = trans->transaction;
-	int updates;
-	int err;
 
 	smp_mb();
 	if (cur_trans->state >= TRANS_STATE_BLOCKED ||
 	    cur_trans->delayed_refs.flushing)
 		return 1;
 
-	updates = trans->delayed_ref_updates;
-	trans->delayed_ref_updates = 0;
-	if (updates) {
-		err = btrfs_run_delayed_refs(trans, updates * 2);
-		if (err) /* Error code will also eval true */
-			return err;
-	}
-
 	return should_end_transaction(trans);
 }
 
@@ -813,11 +831,8 @@
 {
 	struct btrfs_fs_info *info = trans->fs_info;
 	struct btrfs_transaction *cur_trans = trans->transaction;
-	u64 transid = trans->transid;
-	unsigned long cur = trans->delayed_ref_updates;
 	int lock = (trans->type != TRANS_JOIN_NOLOCK);
 	int err = 0;
-	int must_run_delayed_refs = 0;
 
 	if (refcount_read(&trans->use_count) > 1) {
 		refcount_dec(&trans->use_count);
@@ -828,40 +843,10 @@
 	btrfs_trans_release_metadata(trans);
 	trans->block_rsv = NULL;
 
-	if (!list_empty(&trans->new_bgs))
-		btrfs_create_pending_block_groups(trans);
-
-	trans->delayed_ref_updates = 0;
-	if (!trans->sync) {
-		must_run_delayed_refs =
-			btrfs_should_throttle_delayed_refs(trans, info);
-		cur = max_t(unsigned long, cur, 32);
-
-		/*
-		 * don't make the caller wait if they are from a NOLOCK
-		 * or ATTACH transaction, it will deadlock with commit
-		 */
-		if (must_run_delayed_refs == 1 &&
-		    (trans->type & (__TRANS_JOIN_NOLOCK | __TRANS_ATTACH)))
-			must_run_delayed_refs = 2;
-	}
-
-	btrfs_trans_release_metadata(trans);
-	trans->block_rsv = NULL;
-
-	if (!list_empty(&trans->new_bgs))
-		btrfs_create_pending_block_groups(trans);
+	btrfs_create_pending_block_groups(trans);
 
 	btrfs_trans_release_chunk_metadata(trans);
 
-	if (lock && should_end_transaction(trans) &&
-	    READ_ONCE(cur_trans->state) == TRANS_STATE_RUNNING) {
-		spin_lock(&info->trans_lock);
-		if (cur_trans->state == TRANS_STATE_RUNNING)
-			cur_trans->state = TRANS_STATE_BLOCKED;
-		spin_unlock(&info->trans_lock);
-	}
-
 	if (lock && READ_ONCE(cur_trans->state) == TRANS_STATE_BLOCKED) {
 		if (throttle)
 			return btrfs_commit_transaction(trans);
@@ -893,10 +878,6 @@
 	}
 
 	kmem_cache_free(btrfs_trans_handle_cachep, trans);
-	if (must_run_delayed_refs) {
-		btrfs_async_run_delayed_refs(info, cur, transid,
-					     must_run_delayed_refs == 1);
-	}
 	return err;
 }
 
@@ -944,7 +925,7 @@
 		 * superblock that points to btree nodes/leafs for which
 		 * writeback hasn't finished yet (and without errors).
 		 * We cleanup any entries left in the io tree when committing
-		 * the transaction (through clear_btree_io_tree()).
+		 * the transaction (through extent_io_tree_release()).
 		 */
 		if (err == -ENOMEM) {
 			err = 0;
@@ -989,7 +970,7 @@
 		 * left in the io tree. For a log commit, we don't remove them
 		 * after committing the log because the tree can be accessed
 		 * concurrently - we do it only at transaction commit time when
-		 * it's safe to do it (through clear_btree_io_tree()).
+		 * it's safe to do it (through extent_io_tree_release()).
 		 */
 		err = clear_extent_bit(dirty_pages, start, end,
 				       EXTENT_NEED_WAIT, 0, 0, &cached_state);
@@ -1067,7 +1048,7 @@
 	blk_finish_plug(&plug);
 	ret2 = btrfs_wait_extents(fs_info, dirty_pages);
 
-	clear_btree_io_tree(&trans->transaction->dirty_pages);
+	extent_io_tree_release(&trans->transaction->dirty_pages);
 
 	if (ret)
 		return ret;
@@ -1146,17 +1127,17 @@
 	if (ret)
 		return ret;
 
-	ret = btrfs_run_dev_stats(trans, fs_info);
+	ret = btrfs_run_dev_stats(trans);
 	if (ret)
 		return ret;
-	ret = btrfs_run_dev_replace(trans, fs_info);
+	ret = btrfs_run_dev_replace(trans);
 	if (ret)
 		return ret;
 	ret = btrfs_run_qgroups(trans);
 	if (ret)
 		return ret;
 
-	ret = btrfs_setup_space_cache(trans, fs_info);
+	ret = btrfs_setup_space_cache(trans);
 	if (ret)
 		return ret;
 
@@ -1184,7 +1165,7 @@
 	}
 
 	while (!list_empty(dirty_bgs) || !list_empty(io_bgs)) {
-		ret = btrfs_write_dirty_block_groups(trans, fs_info);
+		ret = btrfs_write_dirty_block_groups(trans);
 		if (ret)
 			return ret;
 		ret = btrfs_run_delayed_refs(trans, (unsigned long)-1);
@@ -1197,7 +1178,10 @@
 
 	list_add_tail(&fs_info->extent_root->dirty_list,
 		      &trans->transaction->switch_commits);
-	btrfs_after_dev_replace_commit(fs_info);
+
+	/* Update dev-replace pointer once everything is committed */
+	fs_info->dev_replace.committed_cursor_left =
+		fs_info->dev_replace.cursor_left_last_write_of_item;
 
 	return 0;
 }
@@ -1334,7 +1318,7 @@
 		return 0;
 
 	/*
-	 * Ensure dirty @src will be commited.  Or, after comming
+	 * Ensure dirty @src will be committed.  Or, after coming
 	 * commit_fs_roots() and switch_commit_roots(), any dirty but not
 	 * recorded root will never be updated again, causing an outdated root
 	 * item.
@@ -1545,7 +1529,7 @@
 		goto fail;
 	}
 
-	btrfs_set_lock_blocking(old);
+	btrfs_set_lock_blocking_write(old);
 
 	ret = btrfs_copy_root(trans, root, old, &tmp, objectid);
 	/* clean up in any case */
@@ -1613,10 +1597,9 @@
 	if (ret < 0)
 		goto fail;
 
-	ret = btrfs_insert_dir_item(trans, parent_root,
-				    dentry->d_name.name, dentry->d_name.len,
-				    BTRFS_I(parent_inode), &key,
-				    BTRFS_FT_DIR, index);
+	ret = btrfs_insert_dir_item(trans, dentry->d_name.name,
+				    dentry->d_name.len, BTRFS_I(parent_inode),
+				    &key, BTRFS_FT_DIR, index);
 	/* We have check then name at the beginning, so it is impossible. */
 	BUG_ON(ret == -EEXIST || ret == -EOVERFLOW);
 	if (ret) {
@@ -1839,7 +1822,6 @@
 {
 	struct btrfs_fs_info *fs_info = trans->fs_info;
 	struct btrfs_transaction *cur_trans = trans->transaction;
-	DEFINE_WAIT(wait);
 
 	WARN_ON(refcount_read(&trans->use_count) > 1);
 
@@ -1886,8 +1868,25 @@
 	kmem_cache_free(btrfs_trans_handle_cachep, trans);
 }
 
-static inline int btrfs_start_delalloc_flush(struct btrfs_fs_info *fs_info)
+/*
+ * Release reserved delayed ref space of all pending block groups of the
+ * transaction and remove them from the list
+ */
+static void btrfs_cleanup_pending_block_groups(struct btrfs_trans_handle *trans)
 {
+       struct btrfs_fs_info *fs_info = trans->fs_info;
+       struct btrfs_block_group_cache *block_group, *tmp;
+
+       list_for_each_entry_safe(block_group, tmp, &trans->new_bgs, bg_list) {
+               btrfs_delayed_refs_rsv_release(fs_info, 1);
+               list_del_init(&block_group->bg_list);
+       }
+}
+
+static inline int btrfs_start_delalloc_flush(struct btrfs_trans_handle *trans)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+
 	/*
 	 * We use writeback_inodes_sb here because if we used
 	 * btrfs_start_delalloc_roots we would deadlock with fs freeze.
@@ -1897,22 +1896,50 @@
 	 * from already being in a transaction and our join_transaction doesn't
 	 * have to re-take the fs freeze lock.
 	 */
-	if (btrfs_test_opt(fs_info, FLUSHONCOMMIT))
+	if (btrfs_test_opt(fs_info, FLUSHONCOMMIT)) {
 		writeback_inodes_sb(fs_info->sb, WB_REASON_SYNC);
+	} else {
+		struct btrfs_pending_snapshot *pending;
+		struct list_head *head = &trans->transaction->pending_snapshots;
+
+		/*
+		 * Flush dellaloc for any root that is going to be snapshotted.
+		 * This is done to avoid a corrupted version of files, in the
+		 * snapshots, that had both buffered and direct IO writes (even
+		 * if they were done sequentially) due to an unordered update of
+		 * the inode's size on disk.
+		 */
+		list_for_each_entry(pending, head, list) {
+			int ret;
+
+			ret = btrfs_start_delalloc_snapshot(pending->root);
+			if (ret)
+				return ret;
+		}
+	}
 	return 0;
 }
 
-static inline void btrfs_wait_delalloc_flush(struct btrfs_fs_info *fs_info)
+static inline void btrfs_wait_delalloc_flush(struct btrfs_trans_handle *trans)
 {
-	if (btrfs_test_opt(fs_info, FLUSHONCOMMIT))
-		btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
-}
+	struct btrfs_fs_info *fs_info = trans->fs_info;
 
-static inline void
-btrfs_wait_pending_ordered(struct btrfs_transaction *cur_trans)
-{
-	wait_event(cur_trans->pending_wait,
-		   atomic_read(&cur_trans->pending_ordered) == 0);
+	if (btrfs_test_opt(fs_info, FLUSHONCOMMIT)) {
+		btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
+	} else {
+		struct btrfs_pending_snapshot *pending;
+		struct list_head *head = &trans->transaction->pending_snapshots;
+
+		/*
+		 * Wait for any dellaloc that we started previously for the roots
+		 * that are going to be snapshotted. This is to avoid a corrupted
+		 * version of files in the snapshots that had both buffered and
+		 * direct IO writes (even if they were done sequentially).
+		 */
+		list_for_each_entry(pending, head, list)
+			btrfs_wait_ordered_extents(pending->root,
+						   U64_MAX, 0, U64_MAX);
+	}
 }
 
 int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
@@ -1950,8 +1977,7 @@
 	cur_trans->delayed_refs.flushing = 1;
 	smp_wmb();
 
-	if (!list_empty(&trans->new_bgs))
-		btrfs_create_pending_block_groups(trans);
+	btrfs_create_pending_block_groups(trans);
 
 	ret = btrfs_run_delayed_refs(trans, 0);
 	if (ret) {
@@ -2027,11 +2053,21 @@
 		}
 	} else {
 		spin_unlock(&fs_info->trans_lock);
+		/*
+		 * The previous transaction was aborted and was already removed
+		 * from the list of transactions at fs_info->trans_list. So we
+		 * abort to prevent writing a new superblock that reflects a
+		 * corrupt state (pointing to trees with unwritten nodes/leafs).
+		 */
+		if (test_bit(BTRFS_FS_STATE_TRANS_ABORTED, &fs_info->fs_state)) {
+			ret = -EROFS;
+			goto cleanup_transaction;
+		}
 	}
 
 	extwriter_counter_dec(cur_trans, trans->type);
 
-	ret = btrfs_start_delalloc_flush(fs_info);
+	ret = btrfs_start_delalloc_flush(trans);
 	if (ret)
 		goto cleanup_transaction;
 
@@ -2047,9 +2083,7 @@
 	if (ret)
 		goto cleanup_transaction;
 
-	btrfs_wait_delalloc_flush(fs_info);
-
-	btrfs_wait_pending_ordered(cur_trans);
+	btrfs_wait_delalloc_flush(trans);
 
 	btrfs_scrub_pause(fs_info);
 	/*
@@ -2214,8 +2248,7 @@
 	memcpy(fs_info->super_for_commit, fs_info->super_copy,
 	       sizeof(*fs_info->super_copy));
 
-	btrfs_update_commit_device_size(fs_info);
-	btrfs_update_commit_device_bytes_used(cur_trans);
+	btrfs_commit_device_sizes(cur_trans);
 
 	clear_bit(BTRFS_FS_LOG1_ERR, &fs_info->flags);
 	clear_bit(BTRFS_FS_LOG2_ERR, &fs_info->flags);
@@ -2286,6 +2319,7 @@
 	btrfs_scrub_continue(fs_info);
 cleanup_transaction:
 	btrfs_trans_release_metadata(trans);
+	btrfs_cleanup_pending_block_groups(trans);
 	btrfs_trans_release_chunk_metadata(trans);
 	trans->block_rsv = NULL;
 	btrfs_warn(fs_info, "Skipping commit of aborted transaction.");
@@ -2321,7 +2355,7 @@
 	list_del_init(&root->root_list);
 	spin_unlock(&fs_info->trans_lock);
 
-	btrfs_debug(fs_info, "cleaner removing %llu", root->objectid);
+	btrfs_debug(fs_info, "cleaner removing %llu", root->root_key.objectid);
 
 	btrfs_kill_all_delayed_nodes(root);
 
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index 4cbb1b5..2c5a6f6 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -12,13 +12,13 @@
 #include "ctree.h"
 
 enum btrfs_trans_state {
-	TRANS_STATE_RUNNING		= 0,
-	TRANS_STATE_BLOCKED		= 1,
-	TRANS_STATE_COMMIT_START	= 2,
-	TRANS_STATE_COMMIT_DOING	= 3,
-	TRANS_STATE_UNBLOCKED		= 4,
-	TRANS_STATE_COMPLETED		= 5,
-	TRANS_STATE_MAX			= 6,
+	TRANS_STATE_RUNNING,
+	TRANS_STATE_BLOCKED,
+	TRANS_STATE_COMMIT_START,
+	TRANS_STATE_COMMIT_DOING,
+	TRANS_STATE_UNBLOCKED,
+	TRANS_STATE_COMPLETED,
+	TRANS_STATE_MAX,
 };
 
 #define BTRFS_TRANS_HAVE_FREE_BGS	0
@@ -39,7 +39,6 @@
 	 */
 	atomic_t num_writers;
 	refcount_t use_count;
-	atomic_t pending_ordered;
 
 	unsigned long flags;
 
@@ -51,9 +50,8 @@
 	time64_t start_time;
 	wait_queue_head_t writer_wait;
 	wait_queue_head_t commit_wait;
-	wait_queue_head_t pending_wait;
 	struct list_head pending_snapshots;
-	struct list_head pending_chunks;
+	struct list_head dev_update_list;
 	struct list_head switch_commits;
 	struct list_head dirty_bgs;
 
@@ -82,7 +80,6 @@
 	 */
 	struct mutex cache_write_mutex;
 	spinlock_t dirty_bgs_lock;
-	unsigned int num_dirty_bgs;
 	/* Protected by spin lock fs_info->unused_bgs_lock. */
 	struct list_head deleted_bgs;
 	spinlock_t dropped_roots_lock;
@@ -97,11 +94,13 @@
 #define __TRANS_JOIN		(1U << 11)
 #define __TRANS_JOIN_NOLOCK	(1U << 12)
 #define __TRANS_DUMMY		(1U << 13)
+#define __TRANS_JOIN_NOSTART	(1U << 14)
 
 #define TRANS_START		(__TRANS_START | __TRANS_FREEZABLE)
 #define TRANS_ATTACH		(__TRANS_ATTACH)
 #define TRANS_JOIN		(__TRANS_JOIN | __TRANS_FREEZABLE)
 #define TRANS_JOIN_NOLOCK	(__TRANS_JOIN_NOLOCK)
+#define TRANS_JOIN_NOSTART	(__TRANS_JOIN_NOSTART)
 
 #define TRANS_EXTWRITERS	(__TRANS_START | __TRANS_ATTACH)
 
@@ -122,7 +121,6 @@
 	bool allocating_chunk;
 	bool can_flush_pending_bgs;
 	bool reloc_reserved;
-	bool sync;
 	bool dirty;
 	struct btrfs_root *root;
 	struct btrfs_fs_info *fs_info;
@@ -187,6 +185,7 @@
 					int min_factor);
 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root);
 struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root);
+struct btrfs_trans_handle *btrfs_join_transaction_nostart(struct btrfs_root *root);
 struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root);
 struct btrfs_trans_handle *btrfs_attach_transaction_barrier(
 					struct btrfs_root *root);
@@ -228,5 +227,6 @@
 void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info);
 void btrfs_add_dropped_root(struct btrfs_trans_handle *trans,
 			    struct btrfs_root *root);
+void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans);
 
 #endif
diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
index 3ec712c..076d5b8 100644
--- a/fs/btrfs/tree-checker.c
+++ b/fs/btrfs/tree-checker.c
@@ -15,6 +15,9 @@
  * carefully reviewed otherwise so it does not prevent mount of valid images.
  */
 
+#include <linux/types.h>
+#include <linux/stddef.h>
+#include <linux/error-injection.h>
 #include "ctree.h"
 #include "tree-checker.h"
 #include "disk-io.h"
@@ -27,10 +30,10 @@
  *
  * @type:	leaf or node
  * @identifier:	the necessary info to locate the leaf/node.
- * 		It's recommened to decode key.objecitd/offset if it's
+ * 		It's recommended to decode key.objecitd/offset if it's
  * 		meaningful.
  * @reason:	describe the error
- * @bad_value:	optional, it's recommened to output bad value and its
+ * @bad_value:	optional, it's recommended to output bad value and its
  *		expected value (range).
  *
  * Since comma is used to separate the components, only space is allowed
@@ -41,12 +44,12 @@
  * Append generic "corrupt leaf/node root=%llu block=%llu slot=%d: " to @fmt.
  * Allows callers to customize the output.
  */
-__printf(4, 5)
+__printf(3, 4)
 __cold
-static void generic_err(const struct btrfs_fs_info *fs_info,
-			const struct extent_buffer *eb, int slot,
+static void generic_err(const struct extent_buffer *eb, int slot,
 			const char *fmt, ...)
 {
+	const struct btrfs_fs_info *fs_info = eb->fs_info;
 	struct va_format vaf;
 	va_list args;
 
@@ -66,12 +69,12 @@
  * Customized reporter for extent data item, since its key objectid and
  * offset has its own meaning.
  */
-__printf(4, 5)
+__printf(3, 4)
 __cold
-static void file_extent_err(const struct btrfs_fs_info *fs_info,
-			    const struct extent_buffer *eb, int slot,
+static void file_extent_err(const struct extent_buffer *eb, int slot,
 			    const char *fmt, ...)
 {
+	const struct btrfs_fs_info *fs_info = eb->fs_info;
 	struct btrfs_key key;
 	struct va_format vaf;
 	va_list args;
@@ -94,26 +97,45 @@
  * Return 0 if the btrfs_file_extent_##name is aligned to @alignment
  * Else return 1
  */
-#define CHECK_FE_ALIGNED(fs_info, leaf, slot, fi, name, alignment)	      \
+#define CHECK_FE_ALIGNED(leaf, slot, fi, name, alignment)		      \
 ({									      \
 	if (!IS_ALIGNED(btrfs_file_extent_##name((leaf), (fi)), (alignment))) \
-		file_extent_err((fs_info), (leaf), (slot),		      \
+		file_extent_err((leaf), (slot),				      \
 	"invalid %s for file extent, have %llu, should be aligned to %u",     \
 			(#name), btrfs_file_extent_##name((leaf), (fi)),      \
 			(alignment));					      \
 	(!IS_ALIGNED(btrfs_file_extent_##name((leaf), (fi)), (alignment)));   \
 })
 
-static int check_extent_data_item(struct btrfs_fs_info *fs_info,
-				  struct extent_buffer *leaf,
-				  struct btrfs_key *key, int slot)
+static u64 file_extent_end(struct extent_buffer *leaf,
+			   struct btrfs_key *key,
+			   struct btrfs_file_extent_item *extent)
 {
+	u64 end;
+	u64 len;
+
+	if (btrfs_file_extent_type(leaf, extent) == BTRFS_FILE_EXTENT_INLINE) {
+		len = btrfs_file_extent_ram_bytes(leaf, extent);
+		end = ALIGN(key->offset + len, leaf->fs_info->sectorsize);
+	} else {
+		len = btrfs_file_extent_num_bytes(leaf, extent);
+		end = key->offset + len;
+	}
+	return end;
+}
+
+static int check_extent_data_item(struct extent_buffer *leaf,
+				  struct btrfs_key *key, int slot,
+				  struct btrfs_key *prev_key)
+{
+	struct btrfs_fs_info *fs_info = leaf->fs_info;
 	struct btrfs_file_extent_item *fi;
 	u32 sectorsize = fs_info->sectorsize;
 	u32 item_size = btrfs_item_size_nr(leaf, slot);
+	u64 extent_end;
 
 	if (!IS_ALIGNED(key->offset, sectorsize)) {
-		file_extent_err(fs_info, leaf, slot,
+		file_extent_err(leaf, slot,
 "unaligned file_offset for file extent, have %llu should be aligned to %u",
 			key->offset, sectorsize);
 		return -EUCLEAN;
@@ -122,7 +144,7 @@
 	fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
 
 	if (btrfs_file_extent_type(leaf, fi) > BTRFS_FILE_EXTENT_TYPES) {
-		file_extent_err(fs_info, leaf, slot,
+		file_extent_err(leaf, slot,
 		"invalid type for file extent, have %u expect range [0, %u]",
 			btrfs_file_extent_type(leaf, fi),
 			BTRFS_FILE_EXTENT_TYPES);
@@ -130,18 +152,18 @@
 	}
 
 	/*
-	 * Support for new compression/encrption must introduce incompat flag,
+	 * Support for new compression/encryption must introduce incompat flag,
 	 * and must be caught in open_ctree().
 	 */
 	if (btrfs_file_extent_compression(leaf, fi) > BTRFS_COMPRESS_TYPES) {
-		file_extent_err(fs_info, leaf, slot,
+		file_extent_err(leaf, slot,
 	"invalid compression for file extent, have %u expect range [0, %u]",
 			btrfs_file_extent_compression(leaf, fi),
 			BTRFS_COMPRESS_TYPES);
 		return -EUCLEAN;
 	}
 	if (btrfs_file_extent_encryption(leaf, fi)) {
-		file_extent_err(fs_info, leaf, slot,
+		file_extent_err(leaf, slot,
 			"invalid encryption for file extent, have %u expect 0",
 			btrfs_file_extent_encryption(leaf, fi));
 		return -EUCLEAN;
@@ -149,7 +171,7 @@
 	if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) {
 		/* Inline extent must have 0 as key offset */
 		if (key->offset) {
-			file_extent_err(fs_info, leaf, slot,
+			file_extent_err(leaf, slot,
 		"invalid file_offset for inline file extent, have %llu expect 0",
 				key->offset);
 			return -EUCLEAN;
@@ -163,7 +185,7 @@
 		/* Uncompressed inline extent size must match item size */
 		if (item_size != BTRFS_FILE_EXTENT_INLINE_DATA_START +
 		    btrfs_file_extent_ram_bytes(leaf, fi)) {
-			file_extent_err(fs_info, leaf, slot,
+			file_extent_err(leaf, slot,
 	"invalid ram_bytes for uncompressed inline extent, have %u expect %llu",
 				item_size, BTRFS_FILE_EXTENT_INLINE_DATA_START +
 				btrfs_file_extent_ram_bytes(leaf, fi));
@@ -174,41 +196,73 @@
 
 	/* Regular or preallocated extent has fixed item size */
 	if (item_size != sizeof(*fi)) {
-		file_extent_err(fs_info, leaf, slot,
+		file_extent_err(leaf, slot,
 	"invalid item size for reg/prealloc file extent, have %u expect %zu",
 			item_size, sizeof(*fi));
 		return -EUCLEAN;
 	}
-	if (CHECK_FE_ALIGNED(fs_info, leaf, slot, fi, ram_bytes, sectorsize) ||
-	    CHECK_FE_ALIGNED(fs_info, leaf, slot, fi, disk_bytenr, sectorsize) ||
-	    CHECK_FE_ALIGNED(fs_info, leaf, slot, fi, disk_num_bytes, sectorsize) ||
-	    CHECK_FE_ALIGNED(fs_info, leaf, slot, fi, offset, sectorsize) ||
-	    CHECK_FE_ALIGNED(fs_info, leaf, slot, fi, num_bytes, sectorsize))
+	if (CHECK_FE_ALIGNED(leaf, slot, fi, ram_bytes, sectorsize) ||
+	    CHECK_FE_ALIGNED(leaf, slot, fi, disk_bytenr, sectorsize) ||
+	    CHECK_FE_ALIGNED(leaf, slot, fi, disk_num_bytes, sectorsize) ||
+	    CHECK_FE_ALIGNED(leaf, slot, fi, offset, sectorsize) ||
+	    CHECK_FE_ALIGNED(leaf, slot, fi, num_bytes, sectorsize))
 		return -EUCLEAN;
+
+	/* Catch extent end overflow */
+	if (check_add_overflow(btrfs_file_extent_num_bytes(leaf, fi),
+			       key->offset, &extent_end)) {
+		file_extent_err(leaf, slot,
+	"extent end overflow, have file offset %llu extent num bytes %llu",
+				key->offset,
+				btrfs_file_extent_num_bytes(leaf, fi));
+		return -EUCLEAN;
+	}
+
+	/*
+	 * Check that no two consecutive file extent items, in the same leaf,
+	 * present ranges that overlap each other.
+	 */
+	if (slot > 0 &&
+	    prev_key->objectid == key->objectid &&
+	    prev_key->type == BTRFS_EXTENT_DATA_KEY) {
+		struct btrfs_file_extent_item *prev_fi;
+		u64 prev_end;
+
+		prev_fi = btrfs_item_ptr(leaf, slot - 1,
+					 struct btrfs_file_extent_item);
+		prev_end = file_extent_end(leaf, prev_key, prev_fi);
+		if (prev_end > key->offset) {
+			file_extent_err(leaf, slot - 1,
+"file extent end range (%llu) goes beyond start offset (%llu) of the next file extent",
+					prev_end, key->offset);
+			return -EUCLEAN;
+		}
+	}
+
 	return 0;
 }
 
-static int check_csum_item(struct btrfs_fs_info *fs_info,
-			   struct extent_buffer *leaf, struct btrfs_key *key,
+static int check_csum_item(struct extent_buffer *leaf, struct btrfs_key *key,
 			   int slot)
 {
+	struct btrfs_fs_info *fs_info = leaf->fs_info;
 	u32 sectorsize = fs_info->sectorsize;
 	u32 csumsize = btrfs_super_csum_size(fs_info->super_copy);
 
 	if (key->objectid != BTRFS_EXTENT_CSUM_OBJECTID) {
-		generic_err(fs_info, leaf, slot,
+		generic_err(leaf, slot,
 		"invalid key objectid for csum item, have %llu expect %llu",
 			key->objectid, BTRFS_EXTENT_CSUM_OBJECTID);
 		return -EUCLEAN;
 	}
 	if (!IS_ALIGNED(key->offset, sectorsize)) {
-		generic_err(fs_info, leaf, slot,
+		generic_err(leaf, slot,
 	"unaligned key offset for csum item, have %llu should be aligned to %u",
 			key->offset, sectorsize);
 		return -EUCLEAN;
 	}
 	if (!IS_ALIGNED(btrfs_item_size_nr(leaf, slot), csumsize)) {
-		generic_err(fs_info, leaf, slot,
+		generic_err(leaf, slot,
 	"unaligned item size for csum item, have %u should be aligned to %u",
 			btrfs_item_size_nr(leaf, slot), csumsize);
 		return -EUCLEAN;
@@ -220,12 +274,12 @@
  * Customized reported for dir_item, only important new info is key->objectid,
  * which represents inode number
  */
-__printf(4, 5)
+__printf(3, 4)
 __cold
-static void dir_item_err(const struct btrfs_fs_info *fs_info,
-			 const struct extent_buffer *eb, int slot,
+static void dir_item_err(const struct extent_buffer *eb, int slot,
 			 const char *fmt, ...)
 {
+	const struct btrfs_fs_info *fs_info = eb->fs_info;
 	struct btrfs_key key;
 	struct va_format vaf;
 	va_list args;
@@ -244,10 +298,10 @@
 	va_end(args);
 }
 
-static int check_dir_item(struct btrfs_fs_info *fs_info,
-			  struct extent_buffer *leaf,
+static int check_dir_item(struct extent_buffer *leaf,
 			  struct btrfs_key *key, int slot)
 {
+	struct btrfs_fs_info *fs_info = leaf->fs_info;
 	struct btrfs_dir_item *di;
 	u32 item_size = btrfs_item_size_nr(leaf, slot);
 	u32 cur = 0;
@@ -263,7 +317,7 @@
 
 		/* header itself should not cross item boundary */
 		if (cur + sizeof(*di) > item_size) {
-			dir_item_err(fs_info, leaf, slot,
+			dir_item_err(leaf, slot,
 		"dir item header crosses item boundary, have %zu boundary %u",
 				cur + sizeof(*di), item_size);
 			return -EUCLEAN;
@@ -272,7 +326,7 @@
 		/* dir type check */
 		dir_type = btrfs_dir_type(leaf, di);
 		if (dir_type >= BTRFS_FT_MAX) {
-			dir_item_err(fs_info, leaf, slot,
+			dir_item_err(leaf, slot,
 			"invalid dir item type, have %u expect [0, %u)",
 				dir_type, BTRFS_FT_MAX);
 			return -EUCLEAN;
@@ -280,14 +334,14 @@
 
 		if (key->type == BTRFS_XATTR_ITEM_KEY &&
 		    dir_type != BTRFS_FT_XATTR) {
-			dir_item_err(fs_info, leaf, slot,
+			dir_item_err(leaf, slot,
 		"invalid dir item type for XATTR key, have %u expect %u",
 				dir_type, BTRFS_FT_XATTR);
 			return -EUCLEAN;
 		}
 		if (dir_type == BTRFS_FT_XATTR &&
 		    key->type != BTRFS_XATTR_ITEM_KEY) {
-			dir_item_err(fs_info, leaf, slot,
+			dir_item_err(leaf, slot,
 			"xattr dir type found for non-XATTR key");
 			return -EUCLEAN;
 		}
@@ -300,13 +354,13 @@
 		name_len = btrfs_dir_name_len(leaf, di);
 		data_len = btrfs_dir_data_len(leaf, di);
 		if (name_len > max_name_len) {
-			dir_item_err(fs_info, leaf, slot,
+			dir_item_err(leaf, slot,
 			"dir item name len too long, have %u max %u",
 				name_len, max_name_len);
 			return -EUCLEAN;
 		}
 		if (name_len + data_len > BTRFS_MAX_XATTR_SIZE(fs_info)) {
-			dir_item_err(fs_info, leaf, slot,
+			dir_item_err(leaf, slot,
 			"dir item name and data len too long, have %u max %u",
 				name_len + data_len,
 				BTRFS_MAX_XATTR_SIZE(fs_info));
@@ -314,7 +368,7 @@
 		}
 
 		if (data_len && dir_type != BTRFS_FT_XATTR) {
-			dir_item_err(fs_info, leaf, slot,
+			dir_item_err(leaf, slot,
 			"dir item with invalid data len, have %u expect 0",
 				data_len);
 			return -EUCLEAN;
@@ -324,7 +378,7 @@
 
 		/* header and name/data should not cross item boundary */
 		if (cur + total_size > item_size) {
-			dir_item_err(fs_info, leaf, slot,
+			dir_item_err(leaf, slot,
 		"dir item data crosses item boundary, have %u boundary %u",
 				cur + total_size, item_size);
 			return -EUCLEAN;
@@ -342,7 +396,7 @@
 					(unsigned long)(di + 1), name_len);
 			name_hash = btrfs_name_hash(namebuf, name_len);
 			if (key->offset != name_hash) {
-				dir_item_err(fs_info, leaf, slot,
+				dir_item_err(leaf, slot,
 		"name hash mismatch with key, have 0x%016x expect 0x%016llx",
 					name_hash, key->offset);
 				return -EUCLEAN;
@@ -354,12 +408,12 @@
 	return 0;
 }
 
-__printf(4, 5)
+__printf(3, 4)
 __cold
-static void block_group_err(const struct btrfs_fs_info *fs_info,
-			    const struct extent_buffer *eb, int slot,
+static void block_group_err(const struct extent_buffer *eb, int slot,
 			    const char *fmt, ...)
 {
+	const struct btrfs_fs_info *fs_info = eb->fs_info;
 	struct btrfs_key key;
 	struct va_format vaf;
 	va_list args;
@@ -378,8 +432,7 @@
 	va_end(args);
 }
 
-static int check_block_group_item(struct btrfs_fs_info *fs_info,
-				  struct extent_buffer *leaf,
+static int check_block_group_item(struct extent_buffer *leaf,
 				  struct btrfs_key *key, int slot)
 {
 	struct btrfs_block_group_item bgi;
@@ -392,13 +445,13 @@
 	 * handle it.  We care more about the size.
 	 */
 	if (key->offset == 0) {
-		block_group_err(fs_info, leaf, slot,
+		block_group_err(leaf, slot,
 				"invalid block group size 0");
 		return -EUCLEAN;
 	}
 
 	if (item_size != sizeof(bgi)) {
-		block_group_err(fs_info, leaf, slot,
+		block_group_err(leaf, slot,
 			"invalid item size, have %u expect %zu",
 				item_size, sizeof(bgi));
 		return -EUCLEAN;
@@ -408,7 +461,7 @@
 			   sizeof(bgi));
 	if (btrfs_block_group_chunk_objectid(&bgi) !=
 	    BTRFS_FIRST_CHUNK_TREE_OBJECTID) {
-		block_group_err(fs_info, leaf, slot,
+		block_group_err(leaf, slot,
 		"invalid block group chunk objectid, have %llu expect %llu",
 				btrfs_block_group_chunk_objectid(&bgi),
 				BTRFS_FIRST_CHUNK_TREE_OBJECTID);
@@ -416,7 +469,7 @@
 	}
 
 	if (btrfs_block_group_used(&bgi) > key->offset) {
-		block_group_err(fs_info, leaf, slot,
+		block_group_err(leaf, slot,
 			"invalid block group used, have %llu expect [0, %llu)",
 				btrfs_block_group_used(&bgi), key->offset);
 		return -EUCLEAN;
@@ -424,7 +477,7 @@
 
 	flags = btrfs_block_group_flags(&bgi);
 	if (hweight64(flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) > 1) {
-		block_group_err(fs_info, leaf, slot,
+		block_group_err(leaf, slot,
 "invalid profile flags, have 0x%llx (%lu bits set) expect no more than 1 bit set",
 			flags & BTRFS_BLOCK_GROUP_PROFILE_MASK,
 			hweight64(flags & BTRFS_BLOCK_GROUP_PROFILE_MASK));
@@ -437,7 +490,7 @@
 	    type != BTRFS_BLOCK_GROUP_SYSTEM &&
 	    type != (BTRFS_BLOCK_GROUP_METADATA |
 			   BTRFS_BLOCK_GROUP_DATA)) {
-		block_group_err(fs_info, leaf, slot,
+		block_group_err(leaf, slot,
 "invalid type, have 0x%llx (%lu bits set) expect either 0x%llx, 0x%llx, 0x%llx or 0x%llx",
 			type, hweight64(type),
 			BTRFS_BLOCK_GROUP_DATA, BTRFS_BLOCK_GROUP_METADATA,
@@ -448,43 +501,799 @@
 	return 0;
 }
 
+__printf(4, 5)
+__cold
+static void chunk_err(const struct extent_buffer *leaf,
+		      const struct btrfs_chunk *chunk, u64 logical,
+		      const char *fmt, ...)
+{
+	const struct btrfs_fs_info *fs_info = leaf->fs_info;
+	bool is_sb;
+	struct va_format vaf;
+	va_list args;
+	int i;
+	int slot = -1;
+
+	/* Only superblock eb is able to have such small offset */
+	is_sb = (leaf->start == BTRFS_SUPER_INFO_OFFSET);
+
+	if (!is_sb) {
+		/*
+		 * Get the slot number by iterating through all slots, this
+		 * would provide better readability.
+		 */
+		for (i = 0; i < btrfs_header_nritems(leaf); i++) {
+			if (btrfs_item_ptr_offset(leaf, i) ==
+					(unsigned long)chunk) {
+				slot = i;
+				break;
+			}
+		}
+	}
+	va_start(args, fmt);
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	if (is_sb)
+		btrfs_crit(fs_info,
+		"corrupt superblock syschunk array: chunk_start=%llu, %pV",
+			   logical, &vaf);
+	else
+		btrfs_crit(fs_info,
+	"corrupt leaf: root=%llu block=%llu slot=%d chunk_start=%llu, %pV",
+			   BTRFS_CHUNK_TREE_OBJECTID, leaf->start, slot,
+			   logical, &vaf);
+	va_end(args);
+}
+
+/*
+ * The common chunk check which could also work on super block sys chunk array.
+ *
+ * Return -EUCLEAN if anything is corrupted.
+ * Return 0 if everything is OK.
+ */
+int btrfs_check_chunk_valid(struct extent_buffer *leaf,
+			    struct btrfs_chunk *chunk, u64 logical)
+{
+	struct btrfs_fs_info *fs_info = leaf->fs_info;
+	u64 length;
+	u64 stripe_len;
+	u16 num_stripes;
+	u16 sub_stripes;
+	u64 type;
+	u64 features;
+	bool mixed = false;
+
+	length = btrfs_chunk_length(leaf, chunk);
+	stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
+	num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
+	sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
+	type = btrfs_chunk_type(leaf, chunk);
+
+	if (!num_stripes) {
+		chunk_err(leaf, chunk, logical,
+			  "invalid chunk num_stripes, have %u", num_stripes);
+		return -EUCLEAN;
+	}
+	if (!IS_ALIGNED(logical, fs_info->sectorsize)) {
+		chunk_err(leaf, chunk, logical,
+		"invalid chunk logical, have %llu should aligned to %u",
+			  logical, fs_info->sectorsize);
+		return -EUCLEAN;
+	}
+	if (btrfs_chunk_sector_size(leaf, chunk) != fs_info->sectorsize) {
+		chunk_err(leaf, chunk, logical,
+			  "invalid chunk sectorsize, have %u expect %u",
+			  btrfs_chunk_sector_size(leaf, chunk),
+			  fs_info->sectorsize);
+		return -EUCLEAN;
+	}
+	if (!length || !IS_ALIGNED(length, fs_info->sectorsize)) {
+		chunk_err(leaf, chunk, logical,
+			  "invalid chunk length, have %llu", length);
+		return -EUCLEAN;
+	}
+	if (!is_power_of_2(stripe_len) || stripe_len != BTRFS_STRIPE_LEN) {
+		chunk_err(leaf, chunk, logical,
+			  "invalid chunk stripe length: %llu",
+			  stripe_len);
+		return -EUCLEAN;
+	}
+	if (~(BTRFS_BLOCK_GROUP_TYPE_MASK | BTRFS_BLOCK_GROUP_PROFILE_MASK) &
+	    type) {
+		chunk_err(leaf, chunk, logical,
+			  "unrecognized chunk type: 0x%llx",
+			  ~(BTRFS_BLOCK_GROUP_TYPE_MASK |
+			    BTRFS_BLOCK_GROUP_PROFILE_MASK) &
+			  btrfs_chunk_type(leaf, chunk));
+		return -EUCLEAN;
+	}
+
+	if (!is_power_of_2(type & BTRFS_BLOCK_GROUP_PROFILE_MASK) &&
+	    (type & BTRFS_BLOCK_GROUP_PROFILE_MASK) != 0) {
+		chunk_err(leaf, chunk, logical,
+		"invalid chunk profile flag: 0x%llx, expect 0 or 1 bit set",
+			  type & BTRFS_BLOCK_GROUP_PROFILE_MASK);
+		return -EUCLEAN;
+	}
+	if ((type & BTRFS_BLOCK_GROUP_TYPE_MASK) == 0) {
+		chunk_err(leaf, chunk, logical,
+	"missing chunk type flag, have 0x%llx one bit must be set in 0x%llx",
+			  type, BTRFS_BLOCK_GROUP_TYPE_MASK);
+		return -EUCLEAN;
+	}
+
+	if ((type & BTRFS_BLOCK_GROUP_SYSTEM) &&
+	    (type & (BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA))) {
+		chunk_err(leaf, chunk, logical,
+			  "system chunk with data or metadata type: 0x%llx",
+			  type);
+		return -EUCLEAN;
+	}
+
+	features = btrfs_super_incompat_flags(fs_info->super_copy);
+	if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
+		mixed = true;
+
+	if (!mixed) {
+		if ((type & BTRFS_BLOCK_GROUP_METADATA) &&
+		    (type & BTRFS_BLOCK_GROUP_DATA)) {
+			chunk_err(leaf, chunk, logical,
+			"mixed chunk type in non-mixed mode: 0x%llx", type);
+			return -EUCLEAN;
+		}
+	}
+
+	if ((type & BTRFS_BLOCK_GROUP_RAID10 && sub_stripes != 2) ||
+	    (type & BTRFS_BLOCK_GROUP_RAID1 && num_stripes != 2) ||
+	    (type & BTRFS_BLOCK_GROUP_RAID5 && num_stripes < 2) ||
+	    (type & BTRFS_BLOCK_GROUP_RAID6 && num_stripes < 3) ||
+	    (type & BTRFS_BLOCK_GROUP_DUP && num_stripes != 2) ||
+	    ((type & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 && num_stripes != 1)) {
+		chunk_err(leaf, chunk, logical,
+			"invalid num_stripes:sub_stripes %u:%u for profile %llu",
+			num_stripes, sub_stripes,
+			type & BTRFS_BLOCK_GROUP_PROFILE_MASK);
+		return -EUCLEAN;
+	}
+
+	return 0;
+}
+
+__printf(3, 4)
+__cold
+static void dev_item_err(const struct extent_buffer *eb, int slot,
+			 const char *fmt, ...)
+{
+	struct btrfs_key key;
+	struct va_format vaf;
+	va_list args;
+
+	btrfs_item_key_to_cpu(eb, &key, slot);
+	va_start(args, fmt);
+
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	btrfs_crit(eb->fs_info,
+	"corrupt %s: root=%llu block=%llu slot=%d devid=%llu %pV",
+		btrfs_header_level(eb) == 0 ? "leaf" : "node",
+		btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot,
+		key.objectid, &vaf);
+	va_end(args);
+}
+
+static int check_dev_item(struct extent_buffer *leaf,
+			  struct btrfs_key *key, int slot)
+{
+	struct btrfs_dev_item *ditem;
+
+	if (key->objectid != BTRFS_DEV_ITEMS_OBJECTID) {
+		dev_item_err(leaf, slot,
+			     "invalid objectid: has=%llu expect=%llu",
+			     key->objectid, BTRFS_DEV_ITEMS_OBJECTID);
+		return -EUCLEAN;
+	}
+	ditem = btrfs_item_ptr(leaf, slot, struct btrfs_dev_item);
+	if (btrfs_device_id(leaf, ditem) != key->offset) {
+		dev_item_err(leaf, slot,
+			     "devid mismatch: key has=%llu item has=%llu",
+			     key->offset, btrfs_device_id(leaf, ditem));
+		return -EUCLEAN;
+	}
+
+	/*
+	 * For device total_bytes, we don't have reliable way to check it, as
+	 * it can be 0 for device removal. Device size check can only be done
+	 * by dev extents check.
+	 */
+	if (btrfs_device_bytes_used(leaf, ditem) >
+	    btrfs_device_total_bytes(leaf, ditem)) {
+		dev_item_err(leaf, slot,
+			     "invalid bytes used: have %llu expect [0, %llu]",
+			     btrfs_device_bytes_used(leaf, ditem),
+			     btrfs_device_total_bytes(leaf, ditem));
+		return -EUCLEAN;
+	}
+	/*
+	 * Remaining members like io_align/type/gen/dev_group aren't really
+	 * utilized.  Skip them to make later usage of them easier.
+	 */
+	return 0;
+}
+
+/* Inode item error output has the same format as dir_item_err() */
+#define inode_item_err(fs_info, eb, slot, fmt, ...)			\
+	dir_item_err(eb, slot, fmt, __VA_ARGS__)
+
+static int check_inode_item(struct extent_buffer *leaf,
+			    struct btrfs_key *key, int slot)
+{
+	struct btrfs_fs_info *fs_info = leaf->fs_info;
+	struct btrfs_inode_item *iitem;
+	u64 super_gen = btrfs_super_generation(fs_info->super_copy);
+	u32 valid_mask = (S_IFMT | S_ISUID | S_ISGID | S_ISVTX | 0777);
+	u32 mode;
+
+	if ((key->objectid < BTRFS_FIRST_FREE_OBJECTID ||
+	     key->objectid > BTRFS_LAST_FREE_OBJECTID) &&
+	    key->objectid != BTRFS_ROOT_TREE_DIR_OBJECTID &&
+	    key->objectid != BTRFS_FREE_INO_OBJECTID) {
+		generic_err(leaf, slot,
+	"invalid key objectid: has %llu expect %llu or [%llu, %llu] or %llu",
+			    key->objectid, BTRFS_ROOT_TREE_DIR_OBJECTID,
+			    BTRFS_FIRST_FREE_OBJECTID,
+			    BTRFS_LAST_FREE_OBJECTID,
+			    BTRFS_FREE_INO_OBJECTID);
+		return -EUCLEAN;
+	}
+	if (key->offset != 0) {
+		inode_item_err(fs_info, leaf, slot,
+			"invalid key offset: has %llu expect 0",
+			key->offset);
+		return -EUCLEAN;
+	}
+	iitem = btrfs_item_ptr(leaf, slot, struct btrfs_inode_item);
+
+	/* Here we use super block generation + 1 to handle log tree */
+	if (btrfs_inode_generation(leaf, iitem) > super_gen + 1) {
+		inode_item_err(fs_info, leaf, slot,
+			"invalid inode generation: has %llu expect (0, %llu]",
+			       btrfs_inode_generation(leaf, iitem),
+			       super_gen + 1);
+		return -EUCLEAN;
+	}
+	/* Note for ROOT_TREE_DIR_ITEM, mkfs could set its transid 0 */
+	if (btrfs_inode_transid(leaf, iitem) > super_gen + 1) {
+		inode_item_err(fs_info, leaf, slot,
+			"invalid inode generation: has %llu expect [0, %llu]",
+			       btrfs_inode_transid(leaf, iitem), super_gen + 1);
+		return -EUCLEAN;
+	}
+
+	/*
+	 * For size and nbytes it's better not to be too strict, as for dir
+	 * item its size/nbytes can easily get wrong, but doesn't affect
+	 * anything in the fs. So here we skip the check.
+	 */
+	mode = btrfs_inode_mode(leaf, iitem);
+	if (mode & ~valid_mask) {
+		inode_item_err(fs_info, leaf, slot,
+			       "unknown mode bit detected: 0x%x",
+			       mode & ~valid_mask);
+		return -EUCLEAN;
+	}
+
+	/*
+	 * S_IFMT is not bit mapped so we can't completely rely on is_power_of_2,
+	 * but is_power_of_2() can save us from checking FIFO/CHR/DIR/REG.
+	 * Only needs to check BLK, LNK and SOCKS
+	 */
+	if (!is_power_of_2(mode & S_IFMT)) {
+		if (!S_ISLNK(mode) && !S_ISBLK(mode) && !S_ISSOCK(mode)) {
+			inode_item_err(fs_info, leaf, slot,
+			"invalid mode: has 0%o expect valid S_IF* bit(s)",
+				       mode & S_IFMT);
+			return -EUCLEAN;
+		}
+	}
+	if (S_ISDIR(mode) && btrfs_inode_nlink(leaf, iitem) > 1) {
+		inode_item_err(fs_info, leaf, slot,
+		       "invalid nlink: has %u expect no more than 1 for dir",
+			btrfs_inode_nlink(leaf, iitem));
+		return -EUCLEAN;
+	}
+	if (btrfs_inode_flags(leaf, iitem) & ~BTRFS_INODE_FLAG_MASK) {
+		inode_item_err(fs_info, leaf, slot,
+			       "unknown flags detected: 0x%llx",
+			       btrfs_inode_flags(leaf, iitem) &
+			       ~BTRFS_INODE_FLAG_MASK);
+		return -EUCLEAN;
+	}
+	return 0;
+}
+
+static int check_root_item(struct extent_buffer *leaf, struct btrfs_key *key,
+			   int slot)
+{
+	struct btrfs_fs_info *fs_info = leaf->fs_info;
+	struct btrfs_root_item ri;
+	const u64 valid_root_flags = BTRFS_ROOT_SUBVOL_RDONLY |
+				     BTRFS_ROOT_SUBVOL_DEAD;
+
+	/* No such tree id */
+	if (key->objectid == 0) {
+		generic_err(leaf, slot, "invalid root id 0");
+		return -EUCLEAN;
+	}
+
+	/*
+	 * Some older kernel may create ROOT_ITEM with non-zero offset, so here
+	 * we only check offset for reloc tree whose key->offset must be a
+	 * valid tree.
+	 */
+	if (key->objectid == BTRFS_TREE_RELOC_OBJECTID && key->offset == 0) {
+		generic_err(leaf, slot, "invalid root id 0 for reloc tree");
+		return -EUCLEAN;
+	}
+
+	if (btrfs_item_size_nr(leaf, slot) != sizeof(ri)) {
+		generic_err(leaf, slot,
+			    "invalid root item size, have %u expect %zu",
+			    btrfs_item_size_nr(leaf, slot), sizeof(ri));
+	}
+
+	read_extent_buffer(leaf, &ri, btrfs_item_ptr_offset(leaf, slot),
+			   sizeof(ri));
+
+	/* Generation related */
+	if (btrfs_root_generation(&ri) >
+	    btrfs_super_generation(fs_info->super_copy) + 1) {
+		generic_err(leaf, slot,
+			"invalid root generation, have %llu expect (0, %llu]",
+			    btrfs_root_generation(&ri),
+			    btrfs_super_generation(fs_info->super_copy) + 1);
+		return -EUCLEAN;
+	}
+	if (btrfs_root_generation_v2(&ri) >
+	    btrfs_super_generation(fs_info->super_copy) + 1) {
+		generic_err(leaf, slot,
+		"invalid root v2 generation, have %llu expect (0, %llu]",
+			    btrfs_root_generation_v2(&ri),
+			    btrfs_super_generation(fs_info->super_copy) + 1);
+		return -EUCLEAN;
+	}
+	if (btrfs_root_last_snapshot(&ri) >
+	    btrfs_super_generation(fs_info->super_copy) + 1) {
+		generic_err(leaf, slot,
+		"invalid root last_snapshot, have %llu expect (0, %llu]",
+			    btrfs_root_last_snapshot(&ri),
+			    btrfs_super_generation(fs_info->super_copy) + 1);
+		return -EUCLEAN;
+	}
+
+	/* Alignment and level check */
+	if (!IS_ALIGNED(btrfs_root_bytenr(&ri), fs_info->sectorsize)) {
+		generic_err(leaf, slot,
+		"invalid root bytenr, have %llu expect to be aligned to %u",
+			    btrfs_root_bytenr(&ri), fs_info->sectorsize);
+		return -EUCLEAN;
+	}
+	if (btrfs_root_level(&ri) >= BTRFS_MAX_LEVEL) {
+		generic_err(leaf, slot,
+			    "invalid root level, have %u expect [0, %u]",
+			    btrfs_root_level(&ri), BTRFS_MAX_LEVEL - 1);
+		return -EUCLEAN;
+	}
+	if (ri.drop_level >= BTRFS_MAX_LEVEL) {
+		generic_err(leaf, slot,
+			    "invalid root level, have %u expect [0, %u]",
+			    ri.drop_level, BTRFS_MAX_LEVEL - 1);
+		return -EUCLEAN;
+	}
+
+	/* Flags check */
+	if (btrfs_root_flags(&ri) & ~valid_root_flags) {
+		generic_err(leaf, slot,
+			    "invalid root flags, have 0x%llx expect mask 0x%llx",
+			    btrfs_root_flags(&ri), valid_root_flags);
+		return -EUCLEAN;
+	}
+	return 0;
+}
+
+__printf(3,4)
+__cold
+static void extent_err(const struct extent_buffer *eb, int slot,
+		       const char *fmt, ...)
+{
+	struct btrfs_key key;
+	struct va_format vaf;
+	va_list args;
+	u64 bytenr;
+	u64 len;
+
+	btrfs_item_key_to_cpu(eb, &key, slot);
+	bytenr = key.objectid;
+	if (key.type == BTRFS_METADATA_ITEM_KEY ||
+	    key.type == BTRFS_TREE_BLOCK_REF_KEY ||
+	    key.type == BTRFS_SHARED_BLOCK_REF_KEY)
+		len = eb->fs_info->nodesize;
+	else
+		len = key.offset;
+	va_start(args, fmt);
+
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	btrfs_crit(eb->fs_info,
+	"corrupt %s: block=%llu slot=%d extent bytenr=%llu len=%llu %pV",
+		btrfs_header_level(eb) == 0 ? "leaf" : "node",
+		eb->start, slot, bytenr, len, &vaf);
+	va_end(args);
+}
+
+static int check_extent_item(struct extent_buffer *leaf,
+			     struct btrfs_key *key, int slot)
+{
+	struct btrfs_fs_info *fs_info = leaf->fs_info;
+	struct btrfs_extent_item *ei;
+	bool is_tree_block = false;
+	unsigned long ptr;	/* Current pointer inside inline refs */
+	unsigned long end;	/* Extent item end */
+	const u32 item_size = btrfs_item_size_nr(leaf, slot);
+	u64 flags;
+	u64 generation;
+	u64 total_refs;		/* Total refs in btrfs_extent_item */
+	u64 inline_refs = 0;	/* found total inline refs */
+
+	if (key->type == BTRFS_METADATA_ITEM_KEY &&
+	    !btrfs_fs_incompat(fs_info, SKINNY_METADATA)) {
+		generic_err(leaf, slot,
+"invalid key type, METADATA_ITEM type invalid when SKINNY_METADATA feature disabled");
+		return -EUCLEAN;
+	}
+	/* key->objectid is the bytenr for both key types */
+	if (!IS_ALIGNED(key->objectid, fs_info->sectorsize)) {
+		generic_err(leaf, slot,
+		"invalid key objectid, have %llu expect to be aligned to %u",
+			   key->objectid, fs_info->sectorsize);
+		return -EUCLEAN;
+	}
+
+	/* key->offset is tree level for METADATA_ITEM_KEY */
+	if (key->type == BTRFS_METADATA_ITEM_KEY &&
+	    key->offset >= BTRFS_MAX_LEVEL) {
+		extent_err(leaf, slot,
+			   "invalid tree level, have %llu expect [0, %u]",
+			   key->offset, BTRFS_MAX_LEVEL - 1);
+		return -EUCLEAN;
+	}
+
+	/*
+	 * EXTENT/METADATA_ITEM consists of:
+	 * 1) One btrfs_extent_item
+	 *    Records the total refs, type and generation of the extent.
+	 *
+	 * 2) One btrfs_tree_block_info (for EXTENT_ITEM and tree backref only)
+	 *    Records the first key and level of the tree block.
+	 *
+	 * 2) Zero or more btrfs_extent_inline_ref(s)
+	 *    Each inline ref has one btrfs_extent_inline_ref shows:
+	 *    2.1) The ref type, one of the 4
+	 *         TREE_BLOCK_REF	Tree block only
+	 *         SHARED_BLOCK_REF	Tree block only
+	 *         EXTENT_DATA_REF	Data only
+	 *         SHARED_DATA_REF	Data only
+	 *    2.2) Ref type specific data
+	 *         Either using btrfs_extent_inline_ref::offset, or specific
+	 *         data structure.
+	 */
+	if (item_size < sizeof(*ei)) {
+		extent_err(leaf, slot,
+			   "invalid item size, have %u expect [%zu, %u)",
+			   item_size, sizeof(*ei),
+			   BTRFS_LEAF_DATA_SIZE(fs_info));
+		return -EUCLEAN;
+	}
+	end = item_size + btrfs_item_ptr_offset(leaf, slot);
+
+	/* Checks against extent_item */
+	ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
+	flags = btrfs_extent_flags(leaf, ei);
+	total_refs = btrfs_extent_refs(leaf, ei);
+	generation = btrfs_extent_generation(leaf, ei);
+	if (generation > btrfs_super_generation(fs_info->super_copy) + 1) {
+		extent_err(leaf, slot,
+			   "invalid generation, have %llu expect (0, %llu]",
+			   generation,
+			   btrfs_super_generation(fs_info->super_copy) + 1);
+		return -EUCLEAN;
+	}
+	if (!is_power_of_2(flags & (BTRFS_EXTENT_FLAG_DATA |
+				    BTRFS_EXTENT_FLAG_TREE_BLOCK))) {
+		extent_err(leaf, slot,
+		"invalid extent flag, have 0x%llx expect 1 bit set in 0x%llx",
+			flags, BTRFS_EXTENT_FLAG_DATA |
+			BTRFS_EXTENT_FLAG_TREE_BLOCK);
+		return -EUCLEAN;
+	}
+	is_tree_block = !!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK);
+	if (is_tree_block) {
+		if (key->type == BTRFS_EXTENT_ITEM_KEY &&
+		    key->offset != fs_info->nodesize) {
+			extent_err(leaf, slot,
+				   "invalid extent length, have %llu expect %u",
+				   key->offset, fs_info->nodesize);
+			return -EUCLEAN;
+		}
+	} else {
+		if (key->type != BTRFS_EXTENT_ITEM_KEY) {
+			extent_err(leaf, slot,
+			"invalid key type, have %u expect %u for data backref",
+				   key->type, BTRFS_EXTENT_ITEM_KEY);
+			return -EUCLEAN;
+		}
+		if (!IS_ALIGNED(key->offset, fs_info->sectorsize)) {
+			extent_err(leaf, slot,
+			"invalid extent length, have %llu expect aligned to %u",
+				   key->offset, fs_info->sectorsize);
+			return -EUCLEAN;
+		}
+	}
+	ptr = (unsigned long)(struct btrfs_extent_item *)(ei + 1);
+
+	/* Check the special case of btrfs_tree_block_info */
+	if (is_tree_block && key->type != BTRFS_METADATA_ITEM_KEY) {
+		struct btrfs_tree_block_info *info;
+
+		info = (struct btrfs_tree_block_info *)ptr;
+		if (btrfs_tree_block_level(leaf, info) >= BTRFS_MAX_LEVEL) {
+			extent_err(leaf, slot,
+			"invalid tree block info level, have %u expect [0, %u]",
+				   btrfs_tree_block_level(leaf, info),
+				   BTRFS_MAX_LEVEL - 1);
+			return -EUCLEAN;
+		}
+		ptr = (unsigned long)(struct btrfs_tree_block_info *)(info + 1);
+	}
+
+	/* Check inline refs */
+	while (ptr < end) {
+		struct btrfs_extent_inline_ref *iref;
+		struct btrfs_extent_data_ref *dref;
+		struct btrfs_shared_data_ref *sref;
+		u64 dref_offset;
+		u64 inline_offset;
+		u8 inline_type;
+
+		if (ptr + sizeof(*iref) > end) {
+			extent_err(leaf, slot,
+"inline ref item overflows extent item, ptr %lu iref size %zu end %lu",
+				   ptr, sizeof(*iref), end);
+			return -EUCLEAN;
+		}
+		iref = (struct btrfs_extent_inline_ref *)ptr;
+		inline_type = btrfs_extent_inline_ref_type(leaf, iref);
+		inline_offset = btrfs_extent_inline_ref_offset(leaf, iref);
+		if (ptr + btrfs_extent_inline_ref_size(inline_type) > end) {
+			extent_err(leaf, slot,
+"inline ref item overflows extent item, ptr %lu iref size %u end %lu",
+				   ptr, inline_type, end);
+			return -EUCLEAN;
+		}
+
+		switch (inline_type) {
+		/* inline_offset is subvolid of the owner, no need to check */
+		case BTRFS_TREE_BLOCK_REF_KEY:
+			inline_refs++;
+			break;
+		/* Contains parent bytenr */
+		case BTRFS_SHARED_BLOCK_REF_KEY:
+			if (!IS_ALIGNED(inline_offset, fs_info->sectorsize)) {
+				extent_err(leaf, slot,
+		"invalid tree parent bytenr, have %llu expect aligned to %u",
+					   inline_offset, fs_info->sectorsize);
+				return -EUCLEAN;
+			}
+			inline_refs++;
+			break;
+		/*
+		 * Contains owner subvolid, owner key objectid, adjusted offset.
+		 * The only obvious corruption can happen in that offset.
+		 */
+		case BTRFS_EXTENT_DATA_REF_KEY:
+			dref = (struct btrfs_extent_data_ref *)(&iref->offset);
+			dref_offset = btrfs_extent_data_ref_offset(leaf, dref);
+			if (!IS_ALIGNED(dref_offset, fs_info->sectorsize)) {
+				extent_err(leaf, slot,
+		"invalid data ref offset, have %llu expect aligned to %u",
+					   dref_offset, fs_info->sectorsize);
+				return -EUCLEAN;
+			}
+			inline_refs += btrfs_extent_data_ref_count(leaf, dref);
+			break;
+		/* Contains parent bytenr and ref count */
+		case BTRFS_SHARED_DATA_REF_KEY:
+			sref = (struct btrfs_shared_data_ref *)(iref + 1);
+			if (!IS_ALIGNED(inline_offset, fs_info->sectorsize)) {
+				extent_err(leaf, slot,
+		"invalid data parent bytenr, have %llu expect aligned to %u",
+					   inline_offset, fs_info->sectorsize);
+				return -EUCLEAN;
+			}
+			inline_refs += btrfs_shared_data_ref_count(leaf, sref);
+			break;
+		default:
+			extent_err(leaf, slot, "unknown inline ref type: %u",
+				   inline_type);
+			return -EUCLEAN;
+		}
+		ptr += btrfs_extent_inline_ref_size(inline_type);
+	}
+	/* No padding is allowed */
+	if (ptr != end) {
+		extent_err(leaf, slot,
+			   "invalid extent item size, padding bytes found");
+		return -EUCLEAN;
+	}
+
+	/* Finally, check the inline refs against total refs */
+	if (inline_refs > total_refs) {
+		extent_err(leaf, slot,
+			"invalid extent refs, have %llu expect >= inline %llu",
+			   total_refs, inline_refs);
+		return -EUCLEAN;
+	}
+	return 0;
+}
+
+static int check_simple_keyed_refs(struct extent_buffer *leaf,
+				   struct btrfs_key *key, int slot)
+{
+	u32 expect_item_size = 0;
+
+	if (key->type == BTRFS_SHARED_DATA_REF_KEY)
+		expect_item_size = sizeof(struct btrfs_shared_data_ref);
+
+	if (btrfs_item_size_nr(leaf, slot) != expect_item_size) {
+		generic_err(leaf, slot,
+		"invalid item size, have %u expect %u for key type %u",
+			    btrfs_item_size_nr(leaf, slot),
+			    expect_item_size, key->type);
+		return -EUCLEAN;
+	}
+	if (!IS_ALIGNED(key->objectid, leaf->fs_info->sectorsize)) {
+		generic_err(leaf, slot,
+"invalid key objectid for shared block ref, have %llu expect aligned to %u",
+			    key->objectid, leaf->fs_info->sectorsize);
+		return -EUCLEAN;
+	}
+	if (key->type != BTRFS_TREE_BLOCK_REF_KEY &&
+	    !IS_ALIGNED(key->offset, leaf->fs_info->sectorsize)) {
+		extent_err(leaf, slot,
+		"invalid tree parent bytenr, have %llu expect aligned to %u",
+			   key->offset, leaf->fs_info->sectorsize);
+		return -EUCLEAN;
+	}
+	return 0;
+}
+
+static int check_extent_data_ref(struct extent_buffer *leaf,
+				 struct btrfs_key *key, int slot)
+{
+	struct btrfs_extent_data_ref *dref;
+	unsigned long ptr = btrfs_item_ptr_offset(leaf, slot);
+	const unsigned long end = ptr + btrfs_item_size_nr(leaf, slot);
+
+	if (btrfs_item_size_nr(leaf, slot) % sizeof(*dref) != 0) {
+		generic_err(leaf, slot,
+	"invalid item size, have %u expect aligned to %zu for key type %u",
+			    btrfs_item_size_nr(leaf, slot),
+			    sizeof(*dref), key->type);
+	}
+	if (!IS_ALIGNED(key->objectid, leaf->fs_info->sectorsize)) {
+		generic_err(leaf, slot,
+"invalid key objectid for shared block ref, have %llu expect aligned to %u",
+			    key->objectid, leaf->fs_info->sectorsize);
+		return -EUCLEAN;
+	}
+	for (; ptr < end; ptr += sizeof(*dref)) {
+		u64 root_objectid;
+		u64 owner;
+		u64 offset;
+		u64 hash;
+
+		dref = (struct btrfs_extent_data_ref *)ptr;
+		root_objectid = btrfs_extent_data_ref_root(leaf, dref);
+		owner = btrfs_extent_data_ref_objectid(leaf, dref);
+		offset = btrfs_extent_data_ref_offset(leaf, dref);
+		hash = hash_extent_data_ref(root_objectid, owner, offset);
+		if (hash != key->offset) {
+			extent_err(leaf, slot,
+	"invalid extent data ref hash, item has 0x%016llx key has 0x%016llx",
+				   hash, key->offset);
+			return -EUCLEAN;
+		}
+		if (!IS_ALIGNED(offset, leaf->fs_info->sectorsize)) {
+			extent_err(leaf, slot,
+	"invalid extent data backref offset, have %llu expect aligned to %u",
+				   offset, leaf->fs_info->sectorsize);
+		}
+	}
+	return 0;
+}
+
 /*
  * Common point to switch the item-specific validation.
  */
-static int check_leaf_item(struct btrfs_fs_info *fs_info,
-			   struct extent_buffer *leaf,
-			   struct btrfs_key *key, int slot)
+static int check_leaf_item(struct extent_buffer *leaf,
+			   struct btrfs_key *key, int slot,
+			   struct btrfs_key *prev_key)
 {
 	int ret = 0;
+	struct btrfs_chunk *chunk;
 
 	switch (key->type) {
 	case BTRFS_EXTENT_DATA_KEY:
-		ret = check_extent_data_item(fs_info, leaf, key, slot);
+		ret = check_extent_data_item(leaf, key, slot, prev_key);
 		break;
 	case BTRFS_EXTENT_CSUM_KEY:
-		ret = check_csum_item(fs_info, leaf, key, slot);
+		ret = check_csum_item(leaf, key, slot);
 		break;
 	case BTRFS_DIR_ITEM_KEY:
 	case BTRFS_DIR_INDEX_KEY:
 	case BTRFS_XATTR_ITEM_KEY:
-		ret = check_dir_item(fs_info, leaf, key, slot);
+		ret = check_dir_item(leaf, key, slot);
 		break;
 	case BTRFS_BLOCK_GROUP_ITEM_KEY:
-		ret = check_block_group_item(fs_info, leaf, key, slot);
+		ret = check_block_group_item(leaf, key, slot);
+		break;
+	case BTRFS_CHUNK_ITEM_KEY:
+		chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
+		ret = btrfs_check_chunk_valid(leaf, chunk, key->offset);
+		break;
+	case BTRFS_DEV_ITEM_KEY:
+		ret = check_dev_item(leaf, key, slot);
+		break;
+	case BTRFS_INODE_ITEM_KEY:
+		ret = check_inode_item(leaf, key, slot);
+		break;
+	case BTRFS_ROOT_ITEM_KEY:
+		ret = check_root_item(leaf, key, slot);
+		break;
+	case BTRFS_EXTENT_ITEM_KEY:
+	case BTRFS_METADATA_ITEM_KEY:
+		ret = check_extent_item(leaf, key, slot);
+		break;
+	case BTRFS_TREE_BLOCK_REF_KEY:
+	case BTRFS_SHARED_DATA_REF_KEY:
+	case BTRFS_SHARED_BLOCK_REF_KEY:
+		ret = check_simple_keyed_refs(leaf, key, slot);
+		break;
+	case BTRFS_EXTENT_DATA_REF_KEY:
+		ret = check_extent_data_ref(leaf, key, slot);
 		break;
 	}
 	return ret;
 }
 
-static int check_leaf(struct btrfs_fs_info *fs_info, struct extent_buffer *leaf,
-		      bool check_item_data)
+static int check_leaf(struct extent_buffer *leaf, bool check_item_data)
 {
+	struct btrfs_fs_info *fs_info = leaf->fs_info;
 	/* No valid key type is 0, so all key should be larger than this key */
 	struct btrfs_key prev_key = {0, 0, 0};
 	struct btrfs_key key;
 	u32 nritems = btrfs_header_nritems(leaf);
 	int slot;
 
+	if (btrfs_header_level(leaf) != 0) {
+		generic_err(leaf, 0,
+			"invalid level for leaf, have %d expect 0",
+			btrfs_header_level(leaf));
+		return -EUCLEAN;
+	}
+
 	/*
 	 * Extent buffers from a relocation tree have a owner field that
 	 * corresponds to the subvolume tree they are based on. So just from an
@@ -495,7 +1304,6 @@
 	 */
 	if (nritems == 0 && !btrfs_header_flag(leaf, BTRFS_HEADER_FLAG_RELOC)) {
 		u64 owner = btrfs_header_owner(leaf);
-		struct btrfs_root *check_root;
 
 		/* These trees must never be empty */
 		if (owner == BTRFS_ROOT_TREE_OBJECTID ||
@@ -504,33 +1312,16 @@
 		    owner == BTRFS_DEV_TREE_OBJECTID ||
 		    owner == BTRFS_FS_TREE_OBJECTID ||
 		    owner == BTRFS_DATA_RELOC_TREE_OBJECTID) {
-			generic_err(fs_info, leaf, 0,
+			generic_err(leaf, 0,
 			"invalid root, root %llu must never be empty",
 				    owner);
 			return -EUCLEAN;
 		}
-		key.objectid = owner;
-		key.type = BTRFS_ROOT_ITEM_KEY;
-		key.offset = (u64)-1;
-
-		check_root = btrfs_get_fs_root(fs_info, &key, false);
-		/*
-		 * The only reason we also check NULL here is that during
-		 * open_ctree() some roots has not yet been set up.
-		 */
-		if (!IS_ERR_OR_NULL(check_root)) {
-			struct extent_buffer *eb;
-
-			eb = btrfs_root_node(check_root);
-			/* if leaf is the root, then it's fine */
-			if (leaf != eb) {
-				generic_err(fs_info, leaf, 0,
-		"invalid nritems, have %u should not be 0 for non-root leaf",
-					nritems);
-				free_extent_buffer(eb);
-				return -EUCLEAN;
-			}
-			free_extent_buffer(eb);
+		/* Unknown tree */
+		if (owner == 0) {
+			generic_err(leaf, 0,
+				"invalid owner, root 0 is not defined");
+			return -EUCLEAN;
 		}
 		return 0;
 	}
@@ -557,7 +1348,7 @@
 
 		/* Make sure the keys are in the right order */
 		if (btrfs_comp_cpu_keys(&prev_key, &key) >= 0) {
-			generic_err(fs_info, leaf, slot,
+			generic_err(leaf, slot,
 	"bad key order, prev (%llu %u %llu) current (%llu %u %llu)",
 				prev_key.objectid, prev_key.type,
 				prev_key.offset, key.objectid, key.type,
@@ -576,7 +1367,7 @@
 			item_end_expected = btrfs_item_offset_nr(leaf,
 								 slot - 1);
 		if (btrfs_item_end_nr(leaf, slot) != item_end_expected) {
-			generic_err(fs_info, leaf, slot,
+			generic_err(leaf, slot,
 				"unexpected item end, have %u expect %u",
 				btrfs_item_end_nr(leaf, slot),
 				item_end_expected);
@@ -590,7 +1381,7 @@
 		 */
 		if (btrfs_item_end_nr(leaf, slot) >
 		    BTRFS_LEAF_DATA_SIZE(fs_info)) {
-			generic_err(fs_info, leaf, slot,
+			generic_err(leaf, slot,
 			"slot end outside of leaf, have %u expect range [0, %u]",
 				btrfs_item_end_nr(leaf, slot),
 				BTRFS_LEAF_DATA_SIZE(fs_info));
@@ -600,7 +1391,7 @@
 		/* Also check if the item pointer overlaps with btrfs item. */
 		if (btrfs_item_nr_offset(slot) + sizeof(struct btrfs_item) >
 		    btrfs_item_ptr_offset(leaf, slot)) {
-			generic_err(fs_info, leaf, slot,
+			generic_err(leaf, slot,
 		"slot overlaps with its data, item end %lu data start %lu",
 				btrfs_item_nr_offset(slot) +
 				sizeof(struct btrfs_item),
@@ -613,7 +1404,7 @@
 			 * Check if the item size and content meet other
 			 * criteria
 			 */
-			ret = check_leaf_item(fs_info, leaf, &key, slot);
+			ret = check_leaf_item(leaf, &key, slot, &prev_key);
 			if (ret < 0)
 				return ret;
 		}
@@ -626,26 +1417,33 @@
 	return 0;
 }
 
-int btrfs_check_leaf_full(struct btrfs_fs_info *fs_info,
-			  struct extent_buffer *leaf)
+int btrfs_check_leaf_full(struct extent_buffer *leaf)
 {
-	return check_leaf(fs_info, leaf, true);
+	return check_leaf(leaf, true);
+}
+ALLOW_ERROR_INJECTION(btrfs_check_leaf_full, ERRNO);
+
+int btrfs_check_leaf_relaxed(struct extent_buffer *leaf)
+{
+	return check_leaf(leaf, false);
 }
 
-int btrfs_check_leaf_relaxed(struct btrfs_fs_info *fs_info,
-			     struct extent_buffer *leaf)
+int btrfs_check_node(struct extent_buffer *node)
 {
-	return check_leaf(fs_info, leaf, false);
-}
-
-int btrfs_check_node(struct btrfs_fs_info *fs_info, struct extent_buffer *node)
-{
+	struct btrfs_fs_info *fs_info = node->fs_info;
 	unsigned long nr = btrfs_header_nritems(node);
 	struct btrfs_key key, next_key;
 	int slot;
+	int level = btrfs_header_level(node);
 	u64 bytenr;
 	int ret = 0;
 
+	if (level <= 0 || level >= BTRFS_MAX_LEVEL) {
+		generic_err(node, 0,
+			"invalid level for node, have %d expect [1, %d]",
+			level, BTRFS_MAX_LEVEL - 1);
+		return -EUCLEAN;
+	}
 	if (nr == 0 || nr > BTRFS_NODEPTRS_PER_BLOCK(fs_info)) {
 		btrfs_crit(fs_info,
 "corrupt node: root=%llu block=%llu, nritems too %s, have %lu expect range [1,%u]",
@@ -661,13 +1459,13 @@
 		btrfs_node_key_to_cpu(node, &next_key, slot + 1);
 
 		if (!bytenr) {
-			generic_err(fs_info, node, slot,
+			generic_err(node, slot,
 				"invalid NULL node pointer");
 			ret = -EUCLEAN;
 			goto out;
 		}
 		if (!IS_ALIGNED(bytenr, fs_info->sectorsize)) {
-			generic_err(fs_info, node, slot,
+			generic_err(node, slot,
 			"unaligned pointer, have %llu should be aligned to %u",
 				bytenr, fs_info->sectorsize);
 			ret = -EUCLEAN;
@@ -675,7 +1473,7 @@
 		}
 
 		if (btrfs_comp_cpu_keys(&key, &next_key) >= 0) {
-			generic_err(fs_info, node, slot,
+			generic_err(node, slot,
 	"bad key order, current (%llu %u %llu) next (%llu %u %llu)",
 				key.objectid, key.type, key.offset,
 				next_key.objectid, next_key.type,
@@ -687,3 +1485,4 @@
 out:
 	return ret;
 }
+ALLOW_ERROR_INJECTION(btrfs_check_node, ERRNO);
diff --git a/fs/btrfs/tree-checker.h b/fs/btrfs/tree-checker.h
index ff04327..32fecc9 100644
--- a/fs/btrfs/tree-checker.h
+++ b/fs/btrfs/tree-checker.h
@@ -14,15 +14,16 @@
  * Will check not only the item pointers, but also every possible member
  * in item data.
  */
-int btrfs_check_leaf_full(struct btrfs_fs_info *fs_info,
-			  struct extent_buffer *leaf);
+int btrfs_check_leaf_full(struct extent_buffer *leaf);
 
 /*
  * Less strict leaf checker.
  * Will only check item pointers, not reading item data.
  */
-int btrfs_check_leaf_relaxed(struct btrfs_fs_info *fs_info,
-			     struct extent_buffer *leaf);
-int btrfs_check_node(struct btrfs_fs_info *fs_info, struct extent_buffer *node);
+int btrfs_check_leaf_relaxed(struct extent_buffer *leaf);
+int btrfs_check_node(struct extent_buffer *node);
+
+int btrfs_check_chunk_valid(struct extent_buffer *leaf,
+			    struct btrfs_chunk *chunk, u64 logical);
 
 #endif
diff --git a/fs/btrfs/tree-defrag.c b/fs/btrfs/tree-defrag.c
index 3c0987a..5f9e2dd 100644
--- a/fs/btrfs/tree-defrag.c
+++ b/fs/btrfs/tree-defrag.c
@@ -52,7 +52,7 @@
 		u32 nritems;
 
 		root_node = btrfs_lock_root_node(root);
-		btrfs_set_lock_blocking(root_node);
+		btrfs_set_lock_blocking_write(root_node);
 		nritems = btrfs_header_nritems(root_node);
 		root->defrag_max.objectid = 0;
 		/* from above we know this is not a leaf */
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 16ecb76..8a6cc60 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -8,6 +8,7 @@
 #include <linux/blkdev.h>
 #include <linux/list_sort.h>
 #include <linux/iversion.h>
+#include "misc.h"
 #include "ctree.h"
 #include "tree-log.h"
 #include "disk-io.h"
@@ -24,9 +25,12 @@
  * LOG_INODE_EXISTS means to log just enough to recreate the inode
  * during log replay
  */
-#define LOG_INODE_ALL 0
-#define LOG_INODE_EXISTS 1
-#define LOG_OTHER_INODE 2
+enum {
+	LOG_INODE_ALL,
+	LOG_INODE_EXISTS,
+	LOG_OTHER_INODE,
+	LOG_OTHER_INODE_ALL,
+};
 
 /*
  * directory trouble cases
@@ -80,10 +84,12 @@
  * The last stage is to deal with directories and links and extents
  * and all the other fun semantics
  */
-#define LOG_WALK_PIN_ONLY 0
-#define LOG_WALK_REPLAY_INODES 1
-#define LOG_WALK_REPLAY_DIR_INDEX 2
-#define LOG_WALK_REPLAY_ALL 3
+enum {
+	LOG_WALK_PIN_ONLY,
+	LOG_WALK_REPLAY_INODES,
+	LOG_WALK_REPLAY_DIR_INDEX,
+	LOG_WALK_REPLAY_ALL,
+};
 
 static int btrfs_log_inode(struct btrfs_trans_handle *trans,
 			   struct btrfs_root *root, struct btrfs_inode *inode,
@@ -138,7 +144,7 @@
 	mutex_lock(&root->log_mutex);
 
 	if (root->log_root) {
-		if (btrfs_need_log_full_commit(fs_info, trans)) {
+		if (btrfs_need_log_full_commit(trans)) {
 			ret = -EAGAIN;
 			goto out;
 		}
@@ -187,10 +193,6 @@
 {
 	int ret = -ENOENT;
 
-	smp_mb();
-	if (!root->log_root)
-		return -ENOENT;
-
 	mutex_lock(&root->log_mutex);
 	if (root->log_root) {
 		ret = 0;
@@ -205,14 +207,11 @@
  * until you call btrfs_end_log_trans() or it makes any future
  * log transactions wait until you call btrfs_end_log_trans()
  */
-int btrfs_pin_log_trans(struct btrfs_root *root)
+void btrfs_pin_log_trans(struct btrfs_root *root)
 {
-	int ret = -ENOENT;
-
 	mutex_lock(&root->log_mutex);
 	atomic_inc(&root->log_writers);
 	mutex_unlock(&root->log_mutex);
-	return ret;
 }
 
 /*
@@ -227,6 +226,17 @@
 	}
 }
 
+static int btrfs_write_tree_block(struct extent_buffer *buf)
+{
+	return filemap_fdatawrite_range(buf->pages[0]->mapping, buf->start,
+					buf->start + buf->len - 1);
+}
+
+static void btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
+{
+	filemap_fdatawait_range(buf->pages[0]->mapping,
+			        buf->start, buf->start + buf->len - 1);
+}
 
 /*
  * the walk control struct is used to pass state down the chain when
@@ -306,7 +316,7 @@
 
 	if (!ret && btrfs_buffer_uptodate(eb, gen, 0)) {
 		if (wc->pin && btrfs_header_level(eb) == 0)
-			ret = btrfs_exclude_logged_extents(fs_info, eb);
+			ret = btrfs_exclude_logged_extents(eb);
 		if (wc->write)
 			btrfs_write_tree_block(eb);
 		if (wc->wait)
@@ -335,7 +345,6 @@
 				   struct extent_buffer *eb, int slot,
 				   struct btrfs_key *key)
 {
-	struct btrfs_fs_info *fs_info = root->fs_info;
 	int ret;
 	u32 item_size;
 	u64 saved_i_size = 0;
@@ -456,10 +465,9 @@
 		found_size = btrfs_item_size_nr(path->nodes[0],
 						path->slots[0]);
 		if (found_size > item_size)
-			btrfs_truncate_item(fs_info, path, item_size, 1);
+			btrfs_truncate_item(path, item_size, 1);
 		else if (found_size < item_size)
-			btrfs_extend_item(fs_info, path,
-					  item_size - found_size);
+			btrfs_extend_item(path, item_size - found_size);
 	} else if (ret) {
 		return ret;
 	}
@@ -498,7 +506,7 @@
 			    ino_size != 0) {
 				struct btrfs_map_token token;
 
-				btrfs_init_map_token(&token);
+				btrfs_init_map_token(&token, dst_eb);
 				btrfs_set_token_inode_size(dst_eb, dst_item,
 							   ino_size, &token);
 			}
@@ -696,9 +704,11 @@
 			goto out;
 
 		if (ins.objectid > 0) {
+			struct btrfs_ref ref = { 0 };
 			u64 csum_start;
 			u64 csum_end;
 			LIST_HEAD(ordered_sums);
+
 			/*
 			 * is this extent already allocated in the extent
 			 * allocation tree?  If so, just add a reference
@@ -706,10 +716,13 @@
 			ret = btrfs_lookup_data_extent(fs_info, ins.objectid,
 						ins.offset);
 			if (ret == 0) {
-				ret = btrfs_inc_extent_ref(trans, root,
-						ins.objectid, ins.offset,
-						0, root->root_key.objectid,
+				btrfs_init_generic_ref(&ref,
+						BTRFS_ADD_DELAYED_REF,
+						ins.objectid, ins.offset, 0);
+				btrfs_init_data_ref(&ref,
+						root->root_key.objectid,
 						key->objectid, offset);
+				ret = btrfs_inc_extent_ref(trans, &ref);
 				if (ret)
 					goto out;
 			} else {
@@ -955,7 +968,7 @@
 		if (btrfs_find_name_in_ext_backref(path->nodes[0],
 						   path->slots[0],
 						   ref_objectid,
-						   name, namelen, NULL))
+						   name, namelen))
 			match = 1;
 
 		goto out;
@@ -1147,7 +1160,7 @@
 	}
 	btrfs_release_path(path);
 
-	/* look for a conflicing name */
+	/* look for a conflicting name */
 	di = btrfs_lookup_dir_item(trans, root, path, btrfs_ino(dir),
 				   name, namelen, 0);
 	if (di && !IS_ERR(di)) {
@@ -1254,12 +1267,12 @@
 			goto out;
 
 		if (key->type == BTRFS_INODE_EXTREF_KEY)
-			ret = btrfs_find_name_in_ext_backref(log_eb, log_slot,
-							     parent_id, name,
-							     namelen, NULL);
+			ret = !!btrfs_find_name_in_ext_backref(log_eb, log_slot,
+							       parent_id, name,
+							       namelen);
 		else
-			ret = btrfs_find_name_in_backref(log_eb, log_slot, name,
-							 namelen, NULL);
+			ret = !!btrfs_find_name_in_backref(log_eb, log_slot,
+							   name, namelen);
 
 		if (!ret) {
 			struct inode *dir;
@@ -1321,18 +1334,78 @@
 		goto out;
 	}
 	if (key.type == BTRFS_INODE_EXTREF_KEY)
-		ret = btrfs_find_name_in_ext_backref(path->nodes[0],
-						     path->slots[0], parent_id,
-						     name, namelen, NULL);
+		ret = !!btrfs_find_name_in_ext_backref(path->nodes[0],
+				path->slots[0], parent_id, name, namelen);
 	else
-		ret = btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
-						 name, namelen, NULL);
+		ret = !!btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
+						   name, namelen);
 
 out:
 	btrfs_free_path(path);
 	return ret;
 }
 
+static int add_link(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+		    struct inode *dir, struct inode *inode, const char *name,
+		    int namelen, u64 ref_index)
+{
+	struct btrfs_dir_item *dir_item;
+	struct btrfs_key key;
+	struct btrfs_path *path;
+	struct inode *other_inode = NULL;
+	int ret;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	dir_item = btrfs_lookup_dir_item(NULL, root, path,
+					 btrfs_ino(BTRFS_I(dir)),
+					 name, namelen, 0);
+	if (!dir_item) {
+		btrfs_release_path(path);
+		goto add_link;
+	} else if (IS_ERR(dir_item)) {
+		ret = PTR_ERR(dir_item);
+		goto out;
+	}
+
+	/*
+	 * Our inode's dentry collides with the dentry of another inode which is
+	 * in the log but not yet processed since it has a higher inode number.
+	 * So delete that other dentry.
+	 */
+	btrfs_dir_item_key_to_cpu(path->nodes[0], dir_item, &key);
+	btrfs_release_path(path);
+	other_inode = read_one_inode(root, key.objectid);
+	if (!other_inode) {
+		ret = -ENOENT;
+		goto out;
+	}
+	ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir), BTRFS_I(other_inode),
+				 name, namelen);
+	if (ret)
+		goto out;
+	/*
+	 * If we dropped the link count to 0, bump it so that later the iput()
+	 * on the inode will not free it. We will fixup the link count later.
+	 */
+	if (other_inode->i_nlink == 0)
+		inc_nlink(other_inode);
+
+	ret = btrfs_run_delayed_items(trans);
+	if (ret)
+		goto out;
+add_link:
+	ret = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode),
+			     name, namelen, 0, ref_index);
+out:
+	iput(other_inode);
+	btrfs_free_path(path);
+
+	return ret;
+}
+
 /*
  * replay one inode back reference item found in the log tree.
  * eb, slot and key refer to the buffer and key found in the log tree.
@@ -1469,9 +1542,8 @@
 				goto out;
 
 			/* insert our name */
-			ret = btrfs_add_link(trans, BTRFS_I(dir),
-					BTRFS_I(inode),
-					name, namelen, 0, ref_index);
+			ret = add_link(trans, root, dir, inode, name, namelen,
+				       ref_index);
 			if (ret)
 				goto out;
 
@@ -2666,8 +2738,8 @@
 
 				if (trans) {
 					btrfs_tree_lock(next);
-					btrfs_set_lock_blocking(next);
-					clean_tree_block(fs_info, next);
+					btrfs_set_lock_blocking_write(next);
+					btrfs_clean_tree_block(next);
 					btrfs_wait_tree_block_writeback(next);
 					btrfs_tree_unlock(next);
 				} else {
@@ -2750,8 +2822,8 @@
 
 				if (trans) {
 					btrfs_tree_lock(next);
-					btrfs_set_lock_blocking(next);
-					clean_tree_block(fs_info, next);
+					btrfs_set_lock_blocking_write(next);
+					btrfs_clean_tree_block(next);
 					btrfs_wait_tree_block_writeback(next);
 					btrfs_tree_unlock(next);
 				} else {
@@ -2832,8 +2904,8 @@
 
 			if (trans) {
 				btrfs_tree_lock(next);
-				btrfs_set_lock_blocking(next);
-				clean_tree_block(fs_info, next);
+				btrfs_set_lock_blocking_write(next);
+				btrfs_clean_tree_block(next);
 				btrfs_wait_tree_block_writeback(next);
 				btrfs_tree_unlock(next);
 			} else {
@@ -2860,7 +2932,8 @@
  * in the tree of log roots
  */
 static int update_log_root(struct btrfs_trans_handle *trans,
-			   struct btrfs_root *log)
+			   struct btrfs_root *log,
+			   struct btrfs_root_item *root_item)
 {
 	struct btrfs_fs_info *fs_info = log->fs_info;
 	int ret;
@@ -2868,10 +2941,10 @@
 	if (log->log_transid == 1) {
 		/* insert root item on the first sync */
 		ret = btrfs_insert_root(trans, fs_info->log_root_tree,
-				&log->root_key, &log->root_item);
+				&log->root_key, root_item);
 	} else {
 		ret = btrfs_update_root(trans, fs_info->log_root_tree,
-				&log->root_key, &log->root_item);
+				&log->root_key, root_item);
 	}
 	return ret;
 }
@@ -2969,6 +3042,7 @@
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_root *log = root->log_root;
 	struct btrfs_root *log_root_tree = fs_info->log_root_tree;
+	struct btrfs_root_item new_root_item;
 	int log_transid = 0;
 	struct btrfs_log_ctx root_log_ctx;
 	struct blk_plug plug;
@@ -3008,7 +3082,7 @@
 	}
 
 	/* bail out if we need to do a full commit */
-	if (btrfs_need_log_full_commit(fs_info, trans)) {
+	if (btrfs_need_log_full_commit(trans)) {
 		ret = -EAGAIN;
 		mutex_unlock(&root->log_mutex);
 		goto out;
@@ -3027,12 +3101,26 @@
 	if (ret) {
 		blk_finish_plug(&plug);
 		btrfs_abort_transaction(trans, ret);
-		btrfs_set_log_full_commit(fs_info, trans);
+		btrfs_set_log_full_commit(trans);
 		mutex_unlock(&root->log_mutex);
 		goto out;
 	}
 
+	/*
+	 * We _must_ update under the root->log_mutex in order to make sure we
+	 * have a consistent view of the log root we are trying to commit at
+	 * this moment.
+	 *
+	 * We _must_ copy this into a local copy, because we are not holding the
+	 * log_root_tree->log_mutex yet.  This is important because when we
+	 * commit the log_root_tree we must have a consistent view of the
+	 * log_root_tree when we update the super block to point at the
+	 * log_root_tree bytenr.  If we update the log_root_tree here we'll race
+	 * with the commit and possibly point at the new block which we may not
+	 * have written out.
+	 */
 	btrfs_set_root_node(&log->root_item, log->node);
+	memcpy(&new_root_item, &log->root_item, sizeof(new_root_item));
 
 	root->log_transid++;
 	log->log_transid = root->log_transid;
@@ -3056,9 +3144,15 @@
 
 	mutex_unlock(&log_root_tree->log_mutex);
 
-	ret = update_log_root(trans, log);
-
 	mutex_lock(&log_root_tree->log_mutex);
+
+	/*
+	 * Now we are safe to update the log_root_tree because we're under the
+	 * log_mutex, and we're a current writer so we're holding the commit
+	 * open until we drop the log_mutex.
+	 */
+	ret = update_log_root(trans, log, &new_root_item);
+
 	if (atomic_dec_and_test(&log_root_tree->log_writers)) {
 		/* atomic_dec_and_test implies a barrier */
 		cond_wake_up_nomb(&log_root_tree->log_writer_wait);
@@ -3069,7 +3163,7 @@
 			list_del_init(&root_log_ctx.list);
 
 		blk_finish_plug(&plug);
-		btrfs_set_log_full_commit(fs_info, trans);
+		btrfs_set_log_full_commit(trans);
 
 		if (ret != -ENOSPC) {
 			btrfs_abort_transaction(trans, ret);
@@ -3115,7 +3209,7 @@
 	 * now that we've moved on to the tree of log tree roots,
 	 * check the full commit flag again
 	 */
-	if (btrfs_need_log_full_commit(fs_info, trans)) {
+	if (btrfs_need_log_full_commit(trans)) {
 		blk_finish_plug(&plug);
 		btrfs_wait_tree_log_extents(log, mark);
 		mutex_unlock(&log_root_tree->log_mutex);
@@ -3128,7 +3222,7 @@
 					 EXTENT_DIRTY | EXTENT_NEW);
 	blk_finish_plug(&plug);
 	if (ret) {
-		btrfs_set_log_full_commit(fs_info, trans);
+		btrfs_set_log_full_commit(trans);
 		btrfs_abort_transaction(trans, ret);
 		mutex_unlock(&log_root_tree->log_mutex);
 		goto out_wake_log_root;
@@ -3138,7 +3232,7 @@
 		ret = btrfs_wait_tree_log_extents(log_root_tree,
 						  EXTENT_NEW | EXTENT_DIRTY);
 	if (ret) {
-		btrfs_set_log_full_commit(fs_info, trans);
+		btrfs_set_log_full_commit(trans);
 		mutex_unlock(&log_root_tree->log_mutex);
 		goto out_wake_log_root;
 	}
@@ -3152,7 +3246,7 @@
 	mutex_unlock(&log_root_tree->log_mutex);
 
 	/*
-	 * nobody else is going to jump in and write the the ctree
+	 * Nobody else is going to jump in and write the ctree
 	 * super here because the log_commit atomic below is protecting
 	 * us.  We must be called with a transaction handle pinning
 	 * the running transaction open, so a full commit can't hop
@@ -3160,7 +3254,7 @@
 	 */
 	ret = write_all_supers(fs_info, 1);
 	if (ret) {
-		btrfs_set_log_full_commit(fs_info, trans);
+		btrfs_set_log_full_commit(trans);
 		btrfs_abort_transaction(trans, ret);
 		goto out_wake_log_root;
 	}
@@ -3204,8 +3298,6 @@
 			  struct btrfs_root *log)
 {
 	int ret;
-	u64 start;
-	u64 end;
 	struct walk_control wc = {
 		.free = 1,
 		.process_func = process_one_buffer
@@ -3219,18 +3311,8 @@
 			btrfs_handle_fs_error(log->fs_info, ret, NULL);
 	}
 
-	while (1) {
-		ret = find_first_extent_bit(&log->dirty_log_pages,
-				0, &start, &end,
-				EXTENT_DIRTY | EXTENT_NEW | EXTENT_NEED_WAIT,
-				NULL);
-		if (ret)
-			break;
-
-		clear_extent_bits(&log->dirty_log_pages, start, end,
-				  EXTENT_DIRTY | EXTENT_NEW | EXTENT_NEED_WAIT);
-	}
-
+	clear_extent_bits(&log->dirty_log_pages, 0, (u64)-1,
+			  EXTENT_DIRTY | EXTENT_NEW | EXTENT_NEED_WAIT);
 	free_extent_buffer(log->node);
 	kfree(log);
 }
@@ -3259,6 +3341,30 @@
 }
 
 /*
+ * Check if an inode was logged in the current transaction. We can't always rely
+ * on an inode's logged_trans value, because it's an in-memory only field and
+ * therefore not persisted. This means that its value is lost if the inode gets
+ * evicted and loaded again from disk (in which case it has a value of 0, and
+ * certainly it is smaller then any possible transaction ID), when that happens
+ * the full_sync flag is set in the inode's runtime flags, so on that case we
+ * assume eviction happened and ignore the logged_trans value, assuming the
+ * worst case, that the inode was logged before in the current transaction.
+ */
+static bool inode_logged(struct btrfs_trans_handle *trans,
+			 struct btrfs_inode *inode)
+{
+	if (inode->logged_trans == trans->transid)
+		return true;
+
+	if (inode->last_trans == trans->transid &&
+	    test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags) &&
+	    !test_bit(BTRFS_FS_LOG_RECOVERING, &trans->fs_info->flags))
+		return true;
+
+	return false;
+}
+
+/*
  * If both a file and directory are logged, and unlinks or renames are
  * mixed in, we have a few interesting corners:
  *
@@ -3292,7 +3398,7 @@
 	int bytes_del = 0;
 	u64 dir_ino = btrfs_ino(dir);
 
-	if (dir->logged_trans < trans->transid)
+	if (!inode_logged(trans, dir))
 		return 0;
 
 	ret = join_running_log_trans(root);
@@ -3376,7 +3482,7 @@
 out_unlock:
 	mutex_unlock(&dir->log_mutex);
 	if (ret == -ENOSPC) {
-		btrfs_set_log_full_commit(root->fs_info, trans);
+		btrfs_set_log_full_commit(trans);
 		ret = 0;
 	} else if (ret < 0)
 		btrfs_abort_transaction(trans, ret);
@@ -3392,12 +3498,11 @@
 			       const char *name, int name_len,
 			       struct btrfs_inode *inode, u64 dirid)
 {
-	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_root *log;
 	u64 index;
 	int ret;
 
-	if (inode->logged_trans < trans->transid)
+	if (!inode_logged(trans, inode))
 		return 0;
 
 	ret = join_running_log_trans(root);
@@ -3410,7 +3515,7 @@
 				  dirid, &index);
 	mutex_unlock(&inode->log_mutex);
 	if (ret == -ENOSPC) {
-		btrfs_set_log_full_commit(fs_info, trans);
+		btrfs_set_log_full_commit(trans);
 		ret = 0;
 	} else if (ret < 0 && ret != -ENOENT)
 		btrfs_abort_transaction(trans, ret);
@@ -3532,9 +3637,16 @@
 	}
 	btrfs_release_path(path);
 
-	/* find the first key from this transaction again */
+	/*
+	 * Find the first key from this transaction again.  See the note for
+	 * log_new_dir_dentries, if we're logging a directory recursively we
+	 * won't be holding its i_mutex, which means we can modify the directory
+	 * while we're logging it.  If we remove an entry between our first
+	 * search and this search we'll not find the key again and can just
+	 * bail.
+	 */
 	ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
-	if (WARN_ON(ret != 0))
+	if (ret != 0)
 		goto done;
 
 	/*
@@ -3721,6 +3833,8 @@
 		found_key.type = 0;
 		ret = btrfs_bin_search(path->nodes[0], &found_key, 0,
 				       &start_slot);
+		if (ret < 0)
+			break;
 
 		ret = btrfs_del_items(trans, log, path, start_slot,
 				      path->slots[0] - start_slot + 1);
@@ -3746,7 +3860,7 @@
 {
 	struct btrfs_map_token token;
 
-	btrfs_init_map_token(&token);
+	btrfs_init_map_token(&token, leaf);
 
 	if (log_inode_only) {
 		/* set the generation to zero so the recover code
@@ -4114,6 +4228,7 @@
 							       *last_extent, 0,
 							       0, len, 0, len,
 							       0, 0, 0);
+				*last_extent += len;
 			}
 		}
 	}
@@ -4205,8 +4320,6 @@
 	if (ret)
 		return ret;
 
-	btrfs_init_map_token(&token);
-
 	ret = __btrfs_drop_extents(trans, log, &inode->vfs_inode, path, em->start,
 				   em->start + em->len, NULL, 0, 1,
 				   sizeof(*fi), &extent_inserted);
@@ -4224,6 +4337,7 @@
 			return ret;
 	}
 	leaf = path->nodes[0];
+	btrfs_init_map_token(&token, leaf);
 	fi = btrfs_item_ptr(leaf, path->slots[0],
 			    struct btrfs_file_extent_item);
 
@@ -4386,7 +4500,6 @@
 	struct extent_map *em, *n;
 	struct list_head extents;
 	struct extent_map_tree *tree = &inode->extent_tree;
-	u64 logged_start, logged_end;
 	u64 test_gen;
 	int ret = 0;
 	int num = 0;
@@ -4395,8 +4508,6 @@
 
 	write_lock(&tree->lock);
 	test_gen = root->fs_info->last_trans_committed;
-	logged_start = start;
-	logged_end = end;
 
 	list_for_each_entry_safe(em, n, &tree->modified_extents, list) {
 		/*
@@ -4437,11 +4548,6 @@
 		    em->start >= i_size_read(&inode->vfs_inode))
 			continue;
 
-		if (em->start < logged_start)
-			logged_start = em->start;
-		if ((em->start + em->len - 1) > logged_end)
-			logged_end = em->start + em->len - 1;
-
 		/* Need a ref to keep it from getting evicted from cache */
 		refcount_inc(&em->refs);
 		set_bit(EXTENT_FLAG_LOGGING, &em->flags);
@@ -4504,6 +4610,19 @@
 		item = btrfs_item_ptr(path->nodes[0], path->slots[0],
 				      struct btrfs_inode_item);
 		*size_ret = btrfs_inode_size(path->nodes[0], item);
+		/*
+		 * If the in-memory inode's i_size is smaller then the inode
+		 * size stored in the btree, return the inode's i_size, so
+		 * that we get a correct inode size after replaying the log
+		 * when before a power failure we had a shrinking truncate
+		 * followed by addition of a new name (rename / new hard link).
+		 * Otherwise return the inode size from the btree, to avoid
+		 * data loss when replaying a log due to previously doing a
+		 * write that expands the inode's size and logging a new name
+		 * immediately after.
+		 */
+		if (*size_ret > inode->vfs_inode.i_size)
+			*size_ret = inode->vfs_inode.i_size;
 	}
 
 	btrfs_release_path(path);
@@ -4665,15 +4784,8 @@
 					struct btrfs_file_extent_item);
 
 		if (btrfs_file_extent_type(leaf, extent) ==
-		    BTRFS_FILE_EXTENT_INLINE) {
-			len = btrfs_file_extent_ram_bytes(leaf, extent);
-			ASSERT(len == i_size ||
-			       (len == fs_info->sectorsize &&
-				btrfs_file_extent_compression(leaf, extent) !=
-				BTRFS_COMPRESS_NONE) ||
-			       (len < i_size && i_size < fs_info->sectorsize));
+		    BTRFS_FILE_EXTENT_INLINE)
 			return 0;
-		}
 
 		len = btrfs_file_extent_num_bytes(leaf, extent);
 		/* Last extent goes beyond i_size, no need to log a hole. */
@@ -4740,7 +4852,7 @@
 					 const int slot,
 					 const struct btrfs_key *key,
 					 struct btrfs_inode *inode,
-					 u64 *other_ino)
+					 u64 *other_ino, u64 *other_parent)
 {
 	int ret;
 	struct btrfs_path *search_path;
@@ -4803,8 +4915,13 @@
 			btrfs_dir_item_key_to_cpu(search_path->nodes[0],
 						  di, &di_key);
 			if (di_key.type == BTRFS_INODE_ITEM_KEY) {
-				ret = 1;
-				*other_ino = di_key.objectid;
+				if (di_key.objectid != key->objectid) {
+					ret = 1;
+					*other_ino = di_key.objectid;
+					*other_parent = parent;
+				} else {
+					ret = 0;
+				}
 			} else {
 				ret = -EAGAIN;
 			}
@@ -4824,6 +4941,144 @@
 	return ret;
 }
 
+struct btrfs_ino_list {
+	u64 ino;
+	u64 parent;
+	struct list_head list;
+};
+
+static int log_conflicting_inodes(struct btrfs_trans_handle *trans,
+				  struct btrfs_root *root,
+				  struct btrfs_path *path,
+				  struct btrfs_log_ctx *ctx,
+				  u64 ino, u64 parent)
+{
+	struct btrfs_ino_list *ino_elem;
+	LIST_HEAD(inode_list);
+	int ret = 0;
+
+	ino_elem = kmalloc(sizeof(*ino_elem), GFP_NOFS);
+	if (!ino_elem)
+		return -ENOMEM;
+	ino_elem->ino = ino;
+	ino_elem->parent = parent;
+	list_add_tail(&ino_elem->list, &inode_list);
+
+	while (!list_empty(&inode_list)) {
+		struct btrfs_fs_info *fs_info = root->fs_info;
+		struct btrfs_key key;
+		struct inode *inode;
+
+		ino_elem = list_first_entry(&inode_list, struct btrfs_ino_list,
+					    list);
+		ino = ino_elem->ino;
+		parent = ino_elem->parent;
+		list_del(&ino_elem->list);
+		kfree(ino_elem);
+		if (ret)
+			continue;
+
+		btrfs_release_path(path);
+
+		key.objectid = ino;
+		key.type = BTRFS_INODE_ITEM_KEY;
+		key.offset = 0;
+		inode = btrfs_iget(fs_info->sb, &key, root, NULL);
+		/*
+		 * If the other inode that had a conflicting dir entry was
+		 * deleted in the current transaction, we need to log its parent
+		 * directory.
+		 */
+		if (IS_ERR(inode)) {
+			ret = PTR_ERR(inode);
+			if (ret == -ENOENT) {
+				key.objectid = parent;
+				inode = btrfs_iget(fs_info->sb, &key, root,
+						   NULL);
+				if (IS_ERR(inode)) {
+					ret = PTR_ERR(inode);
+				} else {
+					ret = btrfs_log_inode(trans, root,
+						      BTRFS_I(inode),
+						      LOG_OTHER_INODE_ALL,
+						      0, LLONG_MAX, ctx);
+					btrfs_add_delayed_iput(inode);
+				}
+			}
+			continue;
+		}
+		/*
+		 * We are safe logging the other inode without acquiring its
+		 * lock as long as we log with the LOG_INODE_EXISTS mode. We
+		 * are safe against concurrent renames of the other inode as
+		 * well because during a rename we pin the log and update the
+		 * log with the new name before we unpin it.
+		 */
+		ret = btrfs_log_inode(trans, root, BTRFS_I(inode),
+				      LOG_OTHER_INODE, 0, LLONG_MAX, ctx);
+		if (ret) {
+			btrfs_add_delayed_iput(inode);
+			continue;
+		}
+
+		key.objectid = ino;
+		key.type = BTRFS_INODE_REF_KEY;
+		key.offset = 0;
+		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+		if (ret < 0) {
+			btrfs_add_delayed_iput(inode);
+			continue;
+		}
+
+		while (true) {
+			struct extent_buffer *leaf = path->nodes[0];
+			int slot = path->slots[0];
+			u64 other_ino = 0;
+			u64 other_parent = 0;
+
+			if (slot >= btrfs_header_nritems(leaf)) {
+				ret = btrfs_next_leaf(root, path);
+				if (ret < 0) {
+					break;
+				} else if (ret > 0) {
+					ret = 0;
+					break;
+				}
+				continue;
+			}
+
+			btrfs_item_key_to_cpu(leaf, &key, slot);
+			if (key.objectid != ino ||
+			    (key.type != BTRFS_INODE_REF_KEY &&
+			     key.type != BTRFS_INODE_EXTREF_KEY)) {
+				ret = 0;
+				break;
+			}
+
+			ret = btrfs_check_ref_name_override(leaf, slot, &key,
+					BTRFS_I(inode), &other_ino,
+					&other_parent);
+			if (ret < 0)
+				break;
+			if (ret > 0) {
+				ino_elem = kmalloc(sizeof(*ino_elem), GFP_NOFS);
+				if (!ino_elem) {
+					ret = -ENOMEM;
+					break;
+				}
+				ino_elem->ino = other_ino;
+				ino_elem->parent = other_parent;
+				list_add_tail(&ino_elem->list, &inode_list);
+				ret = 0;
+			}
+			path->slots[0]++;
+		}
+		btrfs_add_delayed_iput(inode);
+	}
+
+	return ret;
+}
+
 /* log a single inode in the tree log.
  * At least one parent directory for this inode must exist in the tree
  * or be logged already.
@@ -4863,6 +5118,7 @@
 	u64 logged_isize = 0;
 	bool need_log_inode_item = true;
 	bool xattrs_logged = false;
+	bool recursive_logging = false;
 
 	path = btrfs_alloc_path();
 	if (!path)
@@ -4908,8 +5164,12 @@
 		return ret;
 	}
 
-	if (inode_only == LOG_OTHER_INODE) {
-		inode_only = LOG_INODE_EXISTS;
+	if (inode_only == LOG_OTHER_INODE || inode_only == LOG_OTHER_INODE_ALL) {
+		recursive_logging = true;
+		if (inode_only == LOG_OTHER_INODE)
+			inode_only = LOG_INODE_EXISTS;
+		else
+			inode_only = LOG_INODE_ALL;
 		mutex_lock_nested(&inode->log_mutex, SINGLE_DEPTH_NESTING);
 	} else {
 		mutex_lock(&inode->log_mutex);
@@ -5004,20 +5264,19 @@
 
 		if ((min_key.type == BTRFS_INODE_REF_KEY ||
 		     min_key.type == BTRFS_INODE_EXTREF_KEY) &&
-		    inode->generation == trans->transid) {
+		    inode->generation == trans->transid &&
+		    !recursive_logging) {
 			u64 other_ino = 0;
+			u64 other_parent = 0;
 
 			ret = btrfs_check_ref_name_override(path->nodes[0],
 					path->slots[0], &min_key, inode,
-					&other_ino);
+					&other_ino, &other_parent);
 			if (ret < 0) {
 				err = ret;
 				goto out_unlock;
 			} else if (ret > 0 && ctx &&
 				   other_ino != btrfs_ino(BTRFS_I(ctx->inode))) {
-				struct btrfs_key inode_key;
-				struct inode *other_inode;
-
 				if (ins_nr > 0) {
 					ins_nr++;
 				} else {
@@ -5033,43 +5292,13 @@
 					goto out_unlock;
 				}
 				ins_nr = 0;
-				btrfs_release_path(path);
-				inode_key.objectid = other_ino;
-				inode_key.type = BTRFS_INODE_ITEM_KEY;
-				inode_key.offset = 0;
-				other_inode = btrfs_iget(fs_info->sb,
-							 &inode_key, root,
-							 NULL);
-				/*
-				 * If the other inode that had a conflicting dir
-				 * entry was deleted in the current transaction,
-				 * we don't need to do more work nor fallback to
-				 * a transaction commit.
-				 */
-				if (other_inode == ERR_PTR(-ENOENT)) {
-					goto next_key;
-				} else if (IS_ERR(other_inode)) {
-					err = PTR_ERR(other_inode);
-					goto out_unlock;
-				}
-				/*
-				 * We are safe logging the other inode without
-				 * acquiring its i_mutex as long as we log with
-				 * the LOG_INODE_EXISTS mode. We're safe against
-				 * concurrent renames of the other inode as well
-				 * because during a rename we pin the log and
-				 * update the log with the new name before we
-				 * unpin it.
-				 */
-				err = btrfs_log_inode(trans, root,
-						BTRFS_I(other_inode),
-						LOG_OTHER_INODE, 0, LLONG_MAX,
-						ctx);
-				iput(other_inode);
+
+				err = log_conflicting_inodes(trans, root, path,
+						ctx, other_ino, other_parent);
 				if (err)
 					goto out_unlock;
-				else
-					goto next_key;
+				btrfs_release_path(path);
+				goto next_key;
 			}
 		}
 
@@ -5232,9 +5461,19 @@
 		}
 	}
 
+	/*
+	 * Don't update last_log_commit if we logged that an inode exists after
+	 * it was loaded to memory (full_sync bit set).
+	 * This is to prevent data loss when we do a write to the inode, then
+	 * the inode gets evicted after all delalloc was flushed, then we log
+	 * it exists (due to a rename for example) and then fsync it. This last
+	 * fsync would do nothing (not logging the extents previously written).
+	 */
 	spin_lock(&inode->lock);
 	inode->logged_trans = trans->transid;
-	inode->last_log_commit = inode->last_sub_trans;
+	if (inode_only != LOG_INODE_EXISTS ||
+	    !test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags))
+		inode->last_log_commit = inode->last_sub_trans;
 	spin_unlock(&inode->lock);
 out_unlock:
 	mutex_unlock(&inode->log_mutex);
@@ -5272,7 +5511,7 @@
 		 * Make sure any commits to the log are forced to be full
 		 * commits.
 		 */
-		btrfs_set_log_full_commit(fs_info, trans);
+		btrfs_set_log_full_commit(trans);
 		ret = true;
 	}
 	mutex_unlock(&inode->log_mutex);
@@ -5294,7 +5533,6 @@
 {
 	int ret = 0;
 	struct dentry *old_parent = NULL;
-	struct btrfs_inode *orig_inode = inode;
 
 	/*
 	 * for regular files, if its inode is already on disk, we don't
@@ -5314,16 +5552,6 @@
 	}
 
 	while (1) {
-		/*
-		 * If we are logging a directory then we start with our inode,
-		 * not our parent's inode, so we need to skip setting the
-		 * logged_trans so that further down in the log code we don't
-		 * think this inode has already been logged.
-		 */
-		if (inode != orig_inode)
-			inode->logged_trans = trans->transid;
-		smp_mb();
-
 		if (btrfs_must_commit_transaction(trans, inode)) {
 			ret = 1;
 			break;
@@ -5478,7 +5706,7 @@
 			}
 
 			if (btrfs_inode_in_log(BTRFS_I(di_inode), trans->transid)) {
-				iput(di_inode);
+				btrfs_add_delayed_iput(di_inode);
 				break;
 			}
 
@@ -5490,7 +5718,7 @@
 			if (!ret &&
 			    btrfs_must_commit_transaction(trans, BTRFS_I(di_inode)))
 				ret = 1;
-			iput(di_inode);
+			btrfs_add_delayed_iput(di_inode);
 			if (ret)
 				goto next_dir_inode;
 			if (ctx->log_new_dentries) {
@@ -5637,7 +5865,7 @@
 			if (!ret && ctx && ctx->log_new_dentries)
 				ret = log_new_dir_dentries(trans, root,
 						   BTRFS_I(dir_inode), ctx);
-			iput(dir_inode);
+			btrfs_add_delayed_iput(dir_inode);
 			if (ret)
 				goto out;
 		}
@@ -5649,6 +5877,190 @@
 	return ret;
 }
 
+static int log_new_ancestors(struct btrfs_trans_handle *trans,
+			     struct btrfs_root *root,
+			     struct btrfs_path *path,
+			     struct btrfs_log_ctx *ctx)
+{
+	struct btrfs_key found_key;
+
+	btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
+
+	while (true) {
+		struct btrfs_fs_info *fs_info = root->fs_info;
+		const u64 last_committed = fs_info->last_trans_committed;
+		struct extent_buffer *leaf = path->nodes[0];
+		int slot = path->slots[0];
+		struct btrfs_key search_key;
+		struct inode *inode;
+		int ret = 0;
+
+		btrfs_release_path(path);
+
+		search_key.objectid = found_key.offset;
+		search_key.type = BTRFS_INODE_ITEM_KEY;
+		search_key.offset = 0;
+		inode = btrfs_iget(fs_info->sb, &search_key, root, NULL);
+		if (IS_ERR(inode))
+			return PTR_ERR(inode);
+
+		if (BTRFS_I(inode)->generation > last_committed)
+			ret = btrfs_log_inode(trans, root, BTRFS_I(inode),
+					      LOG_INODE_EXISTS,
+					      0, LLONG_MAX, ctx);
+		btrfs_add_delayed_iput(inode);
+		if (ret)
+			return ret;
+
+		if (search_key.objectid == BTRFS_FIRST_FREE_OBJECTID)
+			break;
+
+		search_key.type = BTRFS_INODE_REF_KEY;
+		ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
+		if (ret < 0)
+			return ret;
+
+		leaf = path->nodes[0];
+		slot = path->slots[0];
+		if (slot >= btrfs_header_nritems(leaf)) {
+			ret = btrfs_next_leaf(root, path);
+			if (ret < 0)
+				return ret;
+			else if (ret > 0)
+				return -ENOENT;
+			leaf = path->nodes[0];
+			slot = path->slots[0];
+		}
+
+		btrfs_item_key_to_cpu(leaf, &found_key, slot);
+		if (found_key.objectid != search_key.objectid ||
+		    found_key.type != BTRFS_INODE_REF_KEY)
+			return -ENOENT;
+	}
+	return 0;
+}
+
+static int log_new_ancestors_fast(struct btrfs_trans_handle *trans,
+				  struct btrfs_inode *inode,
+				  struct dentry *parent,
+				  struct btrfs_log_ctx *ctx)
+{
+	struct btrfs_root *root = inode->root;
+	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct dentry *old_parent = NULL;
+	struct super_block *sb = inode->vfs_inode.i_sb;
+	int ret = 0;
+
+	while (true) {
+		if (!parent || d_really_is_negative(parent) ||
+		    sb != parent->d_sb)
+			break;
+
+		inode = BTRFS_I(d_inode(parent));
+		if (root != inode->root)
+			break;
+
+		if (inode->generation > fs_info->last_trans_committed) {
+			ret = btrfs_log_inode(trans, root, inode,
+					LOG_INODE_EXISTS, 0, LLONG_MAX, ctx);
+			if (ret)
+				break;
+		}
+		if (IS_ROOT(parent))
+			break;
+
+		parent = dget_parent(parent);
+		dput(old_parent);
+		old_parent = parent;
+	}
+	dput(old_parent);
+
+	return ret;
+}
+
+static int log_all_new_ancestors(struct btrfs_trans_handle *trans,
+				 struct btrfs_inode *inode,
+				 struct dentry *parent,
+				 struct btrfs_log_ctx *ctx)
+{
+	struct btrfs_root *root = inode->root;
+	const u64 ino = btrfs_ino(inode);
+	struct btrfs_path *path;
+	struct btrfs_key search_key;
+	int ret;
+
+	/*
+	 * For a single hard link case, go through a fast path that does not
+	 * need to iterate the fs/subvolume tree.
+	 */
+	if (inode->vfs_inode.i_nlink < 2)
+		return log_new_ancestors_fast(trans, inode, parent, ctx);
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	search_key.objectid = ino;
+	search_key.type = BTRFS_INODE_REF_KEY;
+	search_key.offset = 0;
+again:
+	ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
+	if (ret < 0)
+		goto out;
+	if (ret == 0)
+		path->slots[0]++;
+
+	while (true) {
+		struct extent_buffer *leaf = path->nodes[0];
+		int slot = path->slots[0];
+		struct btrfs_key found_key;
+
+		if (slot >= btrfs_header_nritems(leaf)) {
+			ret = btrfs_next_leaf(root, path);
+			if (ret < 0)
+				goto out;
+			else if (ret > 0)
+				break;
+			continue;
+		}
+
+		btrfs_item_key_to_cpu(leaf, &found_key, slot);
+		if (found_key.objectid != ino ||
+		    found_key.type > BTRFS_INODE_EXTREF_KEY)
+			break;
+
+		/*
+		 * Don't deal with extended references because they are rare
+		 * cases and too complex to deal with (we would need to keep
+		 * track of which subitem we are processing for each item in
+		 * this loop, etc). So just return some error to fallback to
+		 * a transaction commit.
+		 */
+		if (found_key.type == BTRFS_INODE_EXTREF_KEY) {
+			ret = -EMLINK;
+			goto out;
+		}
+
+		/*
+		 * Logging ancestors needs to do more searches on the fs/subvol
+		 * tree, so it releases the path as needed to avoid deadlocks.
+		 * Keep track of the last inode ref key and resume from that key
+		 * after logging all new ancestors for the current hard link.
+		 */
+		memcpy(&search_key, &found_key, sizeof(search_key));
+
+		ret = log_new_ancestors(trans, root, path, ctx);
+		if (ret)
+			goto out;
+		btrfs_release_path(path);
+		goto again;
+	}
+	ret = 0;
+out:
+	btrfs_free_path(path);
+	return ret;
+}
+
 /*
  * helper function around btrfs_log_inode to make sure newly created
  * parent directories also end up in the log.  A minimal inode and backref
@@ -5666,11 +6078,9 @@
 	struct btrfs_root *root = inode->root;
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct super_block *sb;
-	struct dentry *old_parent = NULL;
 	int ret = 0;
 	u64 last_committed = fs_info->last_trans_committed;
 	bool log_dentries = false;
-	struct btrfs_inode *orig_inode = inode;
 
 	sb = inode->vfs_inode.i_sb;
 
@@ -5776,40 +6186,22 @@
 	 * and has a link count of 2.
 	 */
 	if (inode->last_unlink_trans > last_committed) {
-		ret = btrfs_log_all_parents(trans, orig_inode, ctx);
+		ret = btrfs_log_all_parents(trans, inode, ctx);
 		if (ret)
 			goto end_trans;
 	}
 
-	while (1) {
-		if (!parent || d_really_is_negative(parent) || sb != parent->d_sb)
-			break;
+	ret = log_all_new_ancestors(trans, inode, parent, ctx);
+	if (ret)
+		goto end_trans;
 
-		inode = BTRFS_I(d_inode(parent));
-		if (root != inode->root)
-			break;
-
-		if (inode->generation > last_committed) {
-			ret = btrfs_log_inode(trans, root, inode,
-					LOG_INODE_EXISTS, 0, LLONG_MAX, ctx);
-			if (ret)
-				goto end_trans;
-		}
-		if (IS_ROOT(parent))
-			break;
-
-		parent = dget_parent(parent);
-		dput(old_parent);
-		old_parent = parent;
-	}
 	if (log_dentries)
-		ret = log_new_dir_dentries(trans, root, orig_inode, ctx);
+		ret = log_new_dir_dentries(trans, root, inode, ctx);
 	else
 		ret = 0;
 end_trans:
-	dput(old_parent);
 	if (ret < 0) {
-		btrfs_set_log_full_commit(fs_info, trans);
+		btrfs_set_log_full_commit(trans);
 		ret = 1;
 	}
 
@@ -5858,7 +6250,7 @@
 	struct btrfs_fs_info *fs_info = log_root_tree->fs_info;
 	struct walk_control wc = {
 		.process_func = process_one_buffer,
-		.stage = 0,
+		.stage = LOG_WALK_PIN_ONLY,
 	};
 
 	path = btrfs_alloc_path();
@@ -6036,7 +6428,6 @@
 	 * if this directory was already logged any new
 	 * names for this file/dir will get recorded
 	 */
-	smp_mb();
 	if (dir->logged_trans == trans->transid)
 		return;
 
diff --git a/fs/btrfs/tree-log.h b/fs/btrfs/tree-log.h
index 7ab9bb8..132e43d 100644
--- a/fs/btrfs/tree-log.h
+++ b/fs/btrfs/tree-log.h
@@ -15,7 +15,6 @@
 struct btrfs_log_ctx {
 	int log_ret;
 	int log_transid;
-	int io_err;
 	bool log_new_dentries;
 	struct inode *inode;
 	struct list_head list;
@@ -26,22 +25,19 @@
 {
 	ctx->log_ret = 0;
 	ctx->log_transid = 0;
-	ctx->io_err = 0;
 	ctx->log_new_dentries = false;
 	ctx->inode = inode;
 	INIT_LIST_HEAD(&ctx->list);
 }
 
-static inline void btrfs_set_log_full_commit(struct btrfs_fs_info *fs_info,
-					     struct btrfs_trans_handle *trans)
+static inline void btrfs_set_log_full_commit(struct btrfs_trans_handle *trans)
 {
-	WRITE_ONCE(fs_info->last_trans_log_full_commit, trans->transid);
+	WRITE_ONCE(trans->fs_info->last_trans_log_full_commit, trans->transid);
 }
 
-static inline int btrfs_need_log_full_commit(struct btrfs_fs_info *fs_info,
-					     struct btrfs_trans_handle *trans)
+static inline int btrfs_need_log_full_commit(struct btrfs_trans_handle *trans)
 {
-	return READ_ONCE(fs_info->last_trans_log_full_commit) ==
+	return READ_ONCE(trans->fs_info->last_trans_log_full_commit) ==
 		trans->transid;
 }
 
@@ -65,7 +61,7 @@
 			       const char *name, int name_len,
 			       struct btrfs_inode *inode, u64 dirid);
 void btrfs_end_log_trans(struct btrfs_root *root);
-int btrfs_pin_log_trans(struct btrfs_root *root);
+void btrfs_pin_log_trans(struct btrfs_root *root);
 void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans,
 			     struct btrfs_inode *dir, struct btrfs_inode *inode,
 			     int for_rename);
diff --git a/fs/btrfs/uuid-tree.c b/fs/btrfs/uuid-tree.c
index 3b2ae34..91caab6 100644
--- a/fs/btrfs/uuid-tree.c
+++ b/fs/btrfs/uuid-tree.c
@@ -121,12 +121,12 @@
 		 * An item with that type already exists.
 		 * Extend the item and store the new subid at the end.
 		 */
-		btrfs_extend_item(fs_info, path, sizeof(subid_le));
+		btrfs_extend_item(path, sizeof(subid_le));
 		eb = path->nodes[0];
 		slot = path->slots[0];
 		offset = btrfs_item_ptr_offset(eb, slot);
 		offset += btrfs_item_size_nr(eb, slot) - sizeof(subid_le);
-	} else if (ret < 0) {
+	} else {
 		btrfs_warn(fs_info,
 			   "insert uuid item failed %d (0x%016llx, 0x%016llx) type %u!",
 			   ret, (unsigned long long)key.objectid,
@@ -219,7 +219,7 @@
 	move_src = offset + sizeof(subid);
 	move_len = item_size - (move_src - btrfs_item_ptr_offset(eb, slot));
 	memmove_extent_buffer(eb, move_dst, move_src, move_len);
-	btrfs_truncate_item(fs_info, path, item_size - sizeof(subid), 1);
+	btrfs_truncate_item(path, item_size - sizeof(subid), 1);
 
 out:
 	btrfs_free_path(path);
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index f4405e4..e04409f 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -14,6 +14,7 @@
 #include <linux/semaphore.h>
 #include <linux/uuid.h>
 #include <linux/list_sort.h>
+#include "misc.h"
 #include "ctree.h"
 #include "extent_map.h"
 #include "disk-io.h"
@@ -24,9 +25,11 @@
 #include "async-thread.h"
 #include "check-integrity.h"
 #include "rcu-string.h"
-#include "math.h"
 #include "dev-replace.h"
 #include "sysfs.h"
+#include "tree-checker.h"
+#include "space-info.h"
+#include "block-group.h"
 
 const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 	[BTRFS_RAID_RAID10] = {
@@ -37,6 +40,7 @@
 		.tolerated_failures = 1,
 		.devs_increment	= 2,
 		.ncopies	= 2,
+		.nparity        = 0,
 		.raid_name	= "raid10",
 		.bg_flag	= BTRFS_BLOCK_GROUP_RAID10,
 		.mindev_error	= BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET,
@@ -49,6 +53,7 @@
 		.tolerated_failures = 1,
 		.devs_increment	= 2,
 		.ncopies	= 2,
+		.nparity        = 0,
 		.raid_name	= "raid1",
 		.bg_flag	= BTRFS_BLOCK_GROUP_RAID1,
 		.mindev_error	= BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET,
@@ -61,6 +66,7 @@
 		.tolerated_failures = 0,
 		.devs_increment	= 1,
 		.ncopies	= 2,
+		.nparity        = 0,
 		.raid_name	= "dup",
 		.bg_flag	= BTRFS_BLOCK_GROUP_DUP,
 		.mindev_error	= 0,
@@ -73,6 +79,7 @@
 		.tolerated_failures = 0,
 		.devs_increment	= 1,
 		.ncopies	= 1,
+		.nparity        = 0,
 		.raid_name	= "raid0",
 		.bg_flag	= BTRFS_BLOCK_GROUP_RAID0,
 		.mindev_error	= 0,
@@ -85,6 +92,7 @@
 		.tolerated_failures = 0,
 		.devs_increment	= 1,
 		.ncopies	= 1,
+		.nparity        = 0,
 		.raid_name	= "single",
 		.bg_flag	= 0,
 		.mindev_error	= 0,
@@ -96,7 +104,8 @@
 		.devs_min	= 2,
 		.tolerated_failures = 1,
 		.devs_increment	= 1,
-		.ncopies	= 2,
+		.ncopies	= 1,
+		.nparity        = 1,
 		.raid_name	= "raid5",
 		.bg_flag	= BTRFS_BLOCK_GROUP_RAID5,
 		.mindev_error	= BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET,
@@ -108,25 +117,80 @@
 		.devs_min	= 3,
 		.tolerated_failures = 2,
 		.devs_increment	= 1,
-		.ncopies	= 3,
+		.ncopies	= 1,
+		.nparity        = 2,
 		.raid_name	= "raid6",
 		.bg_flag	= BTRFS_BLOCK_GROUP_RAID6,
 		.mindev_error	= BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET,
 	},
 };
 
-const char *get_raid_name(enum btrfs_raid_types type)
+const char *btrfs_bg_type_to_raid_name(u64 flags)
 {
-	if (type >= BTRFS_NR_RAID_TYPES)
+	const int index = btrfs_bg_flags_to_raid_index(flags);
+
+	if (index >= BTRFS_NR_RAID_TYPES)
 		return NULL;
 
-	return btrfs_raid_array[type].raid_name;
+	return btrfs_raid_array[index].raid_name;
 }
 
-static int init_first_rw_device(struct btrfs_trans_handle *trans,
-				struct btrfs_fs_info *fs_info);
+/*
+ * Fill @buf with textual description of @bg_flags, no more than @size_buf
+ * bytes including terminating null byte.
+ */
+void btrfs_describe_block_groups(u64 bg_flags, char *buf, u32 size_buf)
+{
+	int i;
+	int ret;
+	char *bp = buf;
+	u64 flags = bg_flags;
+	u32 size_bp = size_buf;
+
+	if (!flags) {
+		strcpy(bp, "NONE");
+		return;
+	}
+
+#define DESCRIBE_FLAG(flag, desc)						\
+	do {								\
+		if (flags & (flag)) {					\
+			ret = snprintf(bp, size_bp, "%s|", (desc));	\
+			if (ret < 0 || ret >= size_bp)			\
+				goto out_overflow;			\
+			size_bp -= ret;					\
+			bp += ret;					\
+			flags &= ~(flag);				\
+		}							\
+	} while (0)
+
+	DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_DATA, "data");
+	DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_SYSTEM, "system");
+	DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_METADATA, "metadata");
+
+	DESCRIBE_FLAG(BTRFS_AVAIL_ALLOC_BIT_SINGLE, "single");
+	for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)
+		DESCRIBE_FLAG(btrfs_raid_array[i].bg_flag,
+			      btrfs_raid_array[i].raid_name);
+#undef DESCRIBE_FLAG
+
+	if (flags) {
+		ret = snprintf(bp, size_bp, "0x%llx|", flags);
+		size_bp -= ret;
+	}
+
+	if (size_bp < size_buf)
+		buf[size_buf - size_bp - 1] = '\0'; /* remove last | */
+
+	/*
+	 * The text is trimmed, it's up to the caller to provide sufficiently
+	 * large buffer
+	 */
+out_overflow:;
+}
+
+static int init_first_rw_device(struct btrfs_trans_handle *trans);
 static int btrfs_relocate_sys_chunks(struct btrfs_fs_info *fs_info);
-static void __btrfs_reset_dev_stats(struct btrfs_device *dev);
 static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev);
 static void btrfs_dev_stat_print_on_load(struct btrfs_device *device);
 static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
@@ -151,7 +215,7 @@
  * the mutex can be very coarse and can cover long-running operations
  *
  * protects: updates to fs_devices counters like missing devices, rw devices,
- * seeding, structure cloning, openning/closing devices at mount/umount time
+ * seeding, structure cloning, opening/closing devices at mount/umount time
  *
  * global::fs_devs - add, remove, updates to the global list
  *
@@ -176,7 +240,9 @@
  * chunk_mutex
  * -----------
  * protects chunks, adding or removing during allocation, trim or when a new
- * device is added/removed
+ * device is added/removed. Additionally it also protects post_commit_list of
+ * individual devices, since they can be added to the transaction's
+ * post_commit_list only with chunk_mutex held.
  *
  * cleaner_mutex
  * -------------
@@ -238,13 +304,15 @@
 
 /*
  * alloc_fs_devices - allocate struct btrfs_fs_devices
- * @fsid:	if not NULL, copy the uuid to fs_devices::fsid
+ * @fsid:		if not NULL, copy the UUID to fs_devices::fsid
+ * @metadata_fsid:	if not NULL, copy the UUID to fs_devices::metadata_fsid
  *
  * Return a pointer to a new struct btrfs_fs_devices on success, or ERR_PTR().
  * The returned struct is not linked onto any lists and can be destroyed with
  * kfree() right away.
  */
-static struct btrfs_fs_devices *alloc_fs_devices(const u8 *fsid)
+static struct btrfs_fs_devices *alloc_fs_devices(const u8 *fsid,
+						 const u8 *metadata_fsid)
 {
 	struct btrfs_fs_devices *fs_devs;
 
@@ -255,18 +323,24 @@
 	mutex_init(&fs_devs->device_list_mutex);
 
 	INIT_LIST_HEAD(&fs_devs->devices);
-	INIT_LIST_HEAD(&fs_devs->resized_devices);
 	INIT_LIST_HEAD(&fs_devs->alloc_list);
 	INIT_LIST_HEAD(&fs_devs->fs_list);
 	if (fsid)
 		memcpy(fs_devs->fsid, fsid, BTRFS_FSID_SIZE);
 
+	if (metadata_fsid)
+		memcpy(fs_devs->metadata_uuid, metadata_fsid, BTRFS_FSID_SIZE);
+	else if (fsid)
+		memcpy(fs_devs->metadata_uuid, fsid, BTRFS_FSID_SIZE);
+
 	return fs_devs;
 }
 
 void btrfs_free_device(struct btrfs_device *device)
 {
+	WARN_ON(!list_empty(&device->post_commit_list));
 	rcu_string_free(device->name);
+	extent_io_tree_release(&device->alloc_state);
 	bio_put(device->flush_bio);
 	kfree(device);
 }
@@ -284,19 +358,6 @@
 	kfree(fs_devices);
 }
 
-static void btrfs_kobject_uevent(struct block_device *bdev,
-				 enum kobject_action action)
-{
-	int ret;
-
-	ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
-	if (ret)
-		pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
-			action,
-			kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
-			&disk_to_dev(bdev->bd_disk)->kobj);
-}
-
 void __exit btrfs_cleanup_fs_uuids(void)
 {
 	struct btrfs_fs_devices *fs_devices;
@@ -334,7 +395,7 @@
 
 	INIT_LIST_HEAD(&dev->dev_list);
 	INIT_LIST_HEAD(&dev->dev_alloc_list);
-	INIT_LIST_HEAD(&dev->resized_list);
+	INIT_LIST_HEAD(&dev->post_commit_list);
 
 	spin_lock_init(&dev->io_lock);
 
@@ -343,38 +404,62 @@
 	btrfs_device_data_ordered_init(dev);
 	INIT_RADIX_TREE(&dev->reada_zones, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
 	INIT_RADIX_TREE(&dev->reada_extents, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
+	extent_io_tree_init(NULL, &dev->alloc_state, 0, NULL);
 
 	return dev;
 }
 
-/*
- * Find a device specified by @devid or @uuid in the list of @fs_devices, or
- * return NULL.
- *
- * If devid and uuid are both specified, the match must be exact, otherwise
- * only devid is used.
- */
-static struct btrfs_device *find_device(struct btrfs_fs_devices *fs_devices,
-		u64 devid, const u8 *uuid)
-{
-	struct btrfs_device *dev;
-
-	list_for_each_entry(dev, &fs_devices->devices, dev_list) {
-		if (dev->devid == devid &&
-		    (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
-			return dev;
-		}
-	}
-	return NULL;
-}
-
-static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
+static noinline struct btrfs_fs_devices *find_fsid(
+		const u8 *fsid, const u8 *metadata_fsid)
 {
 	struct btrfs_fs_devices *fs_devices;
 
+	ASSERT(fsid);
+
+	if (metadata_fsid) {
+		/*
+		 * Handle scanned device having completed its fsid change but
+		 * belonging to a fs_devices that was created by first scanning
+		 * a device which didn't have its fsid/metadata_uuid changed
+		 * at all and the CHANGING_FSID_V2 flag set.
+		 */
+		list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
+			if (fs_devices->fsid_change &&
+			    memcmp(metadata_fsid, fs_devices->fsid,
+				   BTRFS_FSID_SIZE) == 0 &&
+			    memcmp(fs_devices->fsid, fs_devices->metadata_uuid,
+				   BTRFS_FSID_SIZE) == 0) {
+				return fs_devices;
+			}
+		}
+		/*
+		 * Handle scanned device having completed its fsid change but
+		 * belonging to a fs_devices that was created by a device that
+		 * has an outdated pair of fsid/metadata_uuid and
+		 * CHANGING_FSID_V2 flag set.
+		 */
+		list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
+			if (fs_devices->fsid_change &&
+			    memcmp(fs_devices->metadata_uuid,
+				   fs_devices->fsid, BTRFS_FSID_SIZE) != 0 &&
+			    memcmp(metadata_fsid, fs_devices->metadata_uuid,
+				   BTRFS_FSID_SIZE) == 0) {
+				return fs_devices;
+			}
+		}
+	}
+
+	/* Handle non-split brain cases */
 	list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
-		if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
-			return fs_devices;
+		if (metadata_fsid) {
+			if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0
+			    && memcmp(metadata_fsid, fs_devices->metadata_uuid,
+				      BTRFS_FSID_SIZE) == 0)
+				return fs_devices;
+		} else {
+			if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
+				return fs_devices;
+		}
 	}
 	return NULL;
 }
@@ -622,6 +707,17 @@
 	run_scheduled_bios(device);
 }
 
+static bool device_path_matched(const char *path, struct btrfs_device *device)
+{
+	int found;
+
+	rcu_read_lock();
+	found = strcmp(rcu_str_deref(device->name), path);
+	rcu_read_unlock();
+
+	return found == 0;
+}
+
 /*
  *  Search and remove all stale (devices which are not mounted) devices.
  *  When both inputs are NULL, it will search and release all stale devices.
@@ -629,52 +725,57 @@
  *		matching this path only.
  *  skip_dev:	Optional. Will skip this device when searching for the stale
  *		devices.
+ *  Return:	0 for success or if @path is NULL.
+ * 		-EBUSY if @path is a mounted device.
+ * 		-ENOENT if @path does not match any device in the list.
  */
-static void btrfs_free_stale_devices(const char *path,
+static int btrfs_free_stale_devices(const char *path,
 				     struct btrfs_device *skip_device)
 {
 	struct btrfs_fs_devices *fs_devices, *tmp_fs_devices;
 	struct btrfs_device *device, *tmp_device;
+	int ret = 0;
+
+	if (path)
+		ret = -ENOENT;
 
 	list_for_each_entry_safe(fs_devices, tmp_fs_devices, &fs_uuids, fs_list) {
-		mutex_lock(&fs_devices->device_list_mutex);
-		if (fs_devices->opened) {
-			mutex_unlock(&fs_devices->device_list_mutex);
-			continue;
-		}
 
+		mutex_lock(&fs_devices->device_list_mutex);
 		list_for_each_entry_safe(device, tmp_device,
 					 &fs_devices->devices, dev_list) {
-			int not_found = 0;
-
 			if (skip_device && skip_device == device)
 				continue;
 			if (path && !device->name)
 				continue;
-
-			rcu_read_lock();
-			if (path)
-				not_found = strcmp(rcu_str_deref(device->name),
-						   path);
-			rcu_read_unlock();
-			if (not_found)
+			if (path && !device_path_matched(path, device))
 				continue;
+			if (fs_devices->opened) {
+				/* for an already deleted device return 0 */
+				if (path && ret != 0)
+					ret = -EBUSY;
+				break;
+			}
 
 			/* delete the stale device */
 			fs_devices->num_devices--;
 			list_del(&device->dev_list);
 			btrfs_free_device(device);
 
+			ret = 0;
 			if (fs_devices->num_devices == 0)
 				break;
 		}
 		mutex_unlock(&fs_devices->device_list_mutex);
+
 		if (fs_devices->num_devices == 0) {
 			btrfs_sysfs_remove_fsid(fs_devices);
 			list_del(&fs_devices->fs_list);
 			free_fs_devices(fs_devices);
 		}
 	}
+
+	return ret;
 }
 
 static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices,
@@ -709,6 +810,13 @@
 	device->generation = btrfs_super_generation(disk_super);
 
 	if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
+		if (btrfs_super_incompat_flags(disk_super) &
+		    BTRFS_FEATURE_INCOMPAT_METADATA_UUID) {
+			pr_err(
+		"BTRFS: Invalid seeding and uuid-changed device detected\n");
+			goto error_brelse;
+		}
+
 		clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
 		fs_devices->seeding = 1;
 	} else {
@@ -744,6 +852,51 @@
 }
 
 /*
+ * Handle scanned device having its CHANGING_FSID_V2 flag set and the fs_devices
+ * being created with a disk that has already completed its fsid change.
+ */
+static struct btrfs_fs_devices *find_fsid_inprogress(
+					struct btrfs_super_block *disk_super)
+{
+	struct btrfs_fs_devices *fs_devices;
+
+	list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
+		if (memcmp(fs_devices->metadata_uuid, fs_devices->fsid,
+			   BTRFS_FSID_SIZE) != 0 &&
+		    memcmp(fs_devices->metadata_uuid, disk_super->fsid,
+			   BTRFS_FSID_SIZE) == 0 && !fs_devices->fsid_change) {
+			return fs_devices;
+		}
+	}
+
+	return NULL;
+}
+
+
+static struct btrfs_fs_devices *find_fsid_changed(
+					struct btrfs_super_block *disk_super)
+{
+	struct btrfs_fs_devices *fs_devices;
+
+	/*
+	 * Handles the case where scanned device is part of an fs that had
+	 * multiple successful changes of FSID but curently device didn't
+	 * observe it. Meaning our fsid will be different than theirs.
+	 */
+	list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
+		if (memcmp(fs_devices->metadata_uuid, fs_devices->fsid,
+			   BTRFS_FSID_SIZE) != 0 &&
+		    memcmp(fs_devices->metadata_uuid, disk_super->metadata_uuid,
+			   BTRFS_FSID_SIZE) == 0 &&
+		    memcmp(fs_devices->fsid, disk_super->fsid,
+			   BTRFS_FSID_SIZE) != 0) {
+			return fs_devices;
+		}
+	}
+
+	return NULL;
+}
+/*
  * Add new device to list of registered devices
  *
  * Returns:
@@ -755,25 +908,72 @@
 			   bool *new_device_added)
 {
 	struct btrfs_device *device;
-	struct btrfs_fs_devices *fs_devices;
+	struct btrfs_fs_devices *fs_devices = NULL;
 	struct rcu_string *name;
 	u64 found_transid = btrfs_super_generation(disk_super);
 	u64 devid = btrfs_stack_device_id(&disk_super->dev_item);
+	bool has_metadata_uuid = (btrfs_super_incompat_flags(disk_super) &
+		BTRFS_FEATURE_INCOMPAT_METADATA_UUID);
+	bool fsid_change_in_progress = (btrfs_super_flags(disk_super) &
+					BTRFS_SUPER_FLAG_CHANGING_FSID_V2);
 
-	fs_devices = find_fsid(disk_super->fsid);
+	if (fsid_change_in_progress) {
+		if (!has_metadata_uuid) {
+			/*
+			 * When we have an image which has CHANGING_FSID_V2 set
+			 * it might belong to either a filesystem which has
+			 * disks with completed fsid change or it might belong
+			 * to fs with no UUID changes in effect, handle both.
+			 */
+			fs_devices = find_fsid_inprogress(disk_super);
+			if (!fs_devices)
+				fs_devices = find_fsid(disk_super->fsid, NULL);
+		} else {
+			fs_devices = find_fsid_changed(disk_super);
+		}
+	} else if (has_metadata_uuid) {
+		fs_devices = find_fsid(disk_super->fsid,
+				       disk_super->metadata_uuid);
+	} else {
+		fs_devices = find_fsid(disk_super->fsid, NULL);
+	}
+
+
 	if (!fs_devices) {
-		fs_devices = alloc_fs_devices(disk_super->fsid);
+		if (has_metadata_uuid)
+			fs_devices = alloc_fs_devices(disk_super->fsid,
+						      disk_super->metadata_uuid);
+		else
+			fs_devices = alloc_fs_devices(disk_super->fsid, NULL);
+
 		if (IS_ERR(fs_devices))
 			return ERR_CAST(fs_devices);
 
+		fs_devices->fsid_change = fsid_change_in_progress;
+
 		mutex_lock(&fs_devices->device_list_mutex);
 		list_add(&fs_devices->fs_list, &fs_uuids);
 
 		device = NULL;
 	} else {
 		mutex_lock(&fs_devices->device_list_mutex);
-		device = find_device(fs_devices, devid,
-				disk_super->dev_item.uuid);
+		device = btrfs_find_device(fs_devices, devid,
+				disk_super->dev_item.uuid, NULL, false);
+
+		/*
+		 * If this disk has been pulled into an fs devices created by
+		 * a device which had the CHANGING_FSID_V2 flag then replace the
+		 * metadata_uuid/fsid values of the fs_devices.
+		 */
+		if (has_metadata_uuid && fs_devices->fsid_change &&
+		    found_transid > fs_devices->latest_generation) {
+			memcpy(fs_devices->fsid, disk_super->fsid,
+					BTRFS_FSID_SIZE);
+			memcpy(fs_devices->metadata_uuid,
+					disk_super->metadata_uuid, BTRFS_FSID_SIZE);
+
+			fs_devices->fsid_change = false;
+		}
 	}
 
 	if (!device) {
@@ -850,6 +1050,35 @@
 			return ERR_PTR(-EEXIST);
 		}
 
+		/*
+		 * We are going to replace the device path for a given devid,
+		 * make sure it's the same device if the device is mounted
+		 */
+		if (device->bdev) {
+			struct block_device *path_bdev;
+
+			path_bdev = lookup_bdev(path);
+			if (IS_ERR(path_bdev)) {
+				mutex_unlock(&fs_devices->device_list_mutex);
+				return ERR_CAST(path_bdev);
+			}
+
+			if (device->bdev != path_bdev) {
+				bdput(path_bdev);
+				mutex_unlock(&fs_devices->device_list_mutex);
+				btrfs_warn_in_rcu(device->fs_info,
+			"duplicate device fsid:devid for %pU:%llu old:%s new:%s",
+					disk_super->fsid, devid,
+					rcu_str_deref(device->name), path);
+				return ERR_PTR(-EEXIST);
+			}
+			bdput(path_bdev);
+			btrfs_info_in_rcu(device->fs_info,
+				"device fsid %pU devid %llu moved old:%s new:%s",
+				disk_super->fsid, devid,
+				rcu_str_deref(device->name), path);
+		}
+
 		name = rcu_string_strdup(path, GFP_NOFS);
 		if (!name) {
 			mutex_unlock(&fs_devices->device_list_mutex);
@@ -869,8 +1098,11 @@
 	 * it back. We need it to pick the disk with largest generation
 	 * (as above).
 	 */
-	if (!fs_devices->opened)
+	if (!fs_devices->opened) {
 		device->generation = found_transid;
+		fs_devices->latest_generation = max_t(u64, found_transid,
+						fs_devices->latest_generation);
+	}
 
 	fs_devices->total_devices = btrfs_super_num_devices(disk_super);
 
@@ -883,22 +1115,24 @@
 	struct btrfs_fs_devices *fs_devices;
 	struct btrfs_device *device;
 	struct btrfs_device *orig_dev;
+	int ret = 0;
 
-	fs_devices = alloc_fs_devices(orig->fsid);
+	fs_devices = alloc_fs_devices(orig->fsid, NULL);
 	if (IS_ERR(fs_devices))
 		return fs_devices;
 
 	mutex_lock(&orig->device_list_mutex);
 	fs_devices->total_devices = orig->total_devices;
 
-	/* We have held the volume lock, it is safe to get the devices. */
 	list_for_each_entry(orig_dev, &orig->devices, dev_list) {
 		struct rcu_string *name;
 
 		device = btrfs_alloc_device(NULL, &orig_dev->devid,
 					    orig_dev->uuid);
-		if (IS_ERR(device))
+		if (IS_ERR(device)) {
+			ret = PTR_ERR(device);
 			goto error;
+		}
 
 		/*
 		 * This is ok to do without rcu read locked because we hold the
@@ -909,6 +1143,7 @@
 					GFP_KERNEL);
 			if (!name) {
 				btrfs_free_device(device);
+				ret = -ENOMEM;
 				goto error;
 			}
 			rcu_assign_pointer(device->name, name);
@@ -923,7 +1158,7 @@
 error:
 	mutex_unlock(&orig->device_list_mutex);
 	free_fs_devices(fs_devices);
-	return ERR_PTR(-ENOMEM);
+	return ERR_PTR(ret);
 }
 
 /*
@@ -993,14 +1228,6 @@
 	mutex_unlock(&uuid_mutex);
 }
 
-static void free_device_rcu(struct rcu_head *head)
-{
-	struct btrfs_device *device;
-
-	device = container_of(head, struct btrfs_device, rcu);
-	btrfs_free_device(device);
-}
-
 static void btrfs_close_bdev(struct btrfs_device *device)
 {
 	if (!device->bdev)
@@ -1048,7 +1275,8 @@
 	list_replace_rcu(&device->dev_list, &new_device->dev_list);
 	new_device->fs_devices = device->fs_devices;
 
-	call_rcu(&device->rcu, free_device_rcu);
+	synchronize_rcu();
+	btrfs_free_device(device);
 }
 
 static int close_fs_devices(struct btrfs_fs_devices *fs_devices)
@@ -1193,7 +1421,7 @@
 	p = kmap(*page);
 
 	/* align our pointer to the offset of the super block */
-	*disk_super = p + (bytenr & ~PAGE_MASK);
+	*disk_super = p + offset_in_page(bytenr);
 
 	if (btrfs_super_bytenr(*disk_super) != bytenr ||
 	    btrfs_super_magic(*disk_super) != BTRFS_MAGIC) {
@@ -1208,6 +1436,17 @@
 	return 0;
 }
 
+int btrfs_forget_devices(const char *path)
+{
+	int ret;
+
+	mutex_lock(&uuid_mutex);
+	ret = btrfs_free_stale_devices(strlen(path) ? path : NULL, NULL);
+	mutex_unlock(&uuid_mutex);
+
+	return ret;
+}
+
 /*
  * Look for a btrfs signature on a device. This may be called out of the mount path
  * and we are not allowed to call set_blocksize during the scan. The superblock
@@ -1257,58 +1496,29 @@
 	return device;
 }
 
-static int contains_pending_extent(struct btrfs_transaction *transaction,
-				   struct btrfs_device *device,
-				   u64 *start, u64 len)
+/*
+ * Try to find a chunk that intersects [start, start + len] range and when one
+ * such is found, record the end of it in *start
+ */
+static bool contains_pending_extent(struct btrfs_device *device, u64 *start,
+				    u64 len)
 {
-	struct btrfs_fs_info *fs_info = device->fs_info;
-	struct extent_map *em;
-	struct list_head *search_list = &fs_info->pinned_chunks;
-	int ret = 0;
-	u64 physical_start = *start;
+	u64 physical_start, physical_end;
 
-	if (transaction)
-		search_list = &transaction->pending_chunks;
-again:
-	list_for_each_entry(em, search_list, list) {
-		struct map_lookup *map;
-		int i;
+	lockdep_assert_held(&device->fs_info->chunk_mutex);
 
-		map = em->map_lookup;
-		for (i = 0; i < map->num_stripes; i++) {
-			u64 end;
+	if (!find_first_extent_bit(&device->alloc_state, *start,
+				   &physical_start, &physical_end,
+				   CHUNK_ALLOCATED, NULL)) {
 
-			if (map->stripes[i].dev != device)
-				continue;
-			if (map->stripes[i].physical >= physical_start + len ||
-			    map->stripes[i].physical + em->orig_block_len <=
-			    physical_start)
-				continue;
-			/*
-			 * Make sure that while processing the pinned list we do
-			 * not override our *start with a lower value, because
-			 * we can have pinned chunks that fall within this
-			 * device hole and that have lower physical addresses
-			 * than the pending chunks we processed before. If we
-			 * do not take this special care we can end up getting
-			 * 2 pending chunks that start at the same physical
-			 * device offsets because the end offset of a pinned
-			 * chunk can be equal to the start offset of some
-			 * pending chunk.
-			 */
-			end = map->stripes[i].physical + em->orig_block_len;
-			if (end > *start) {
-				*start = end;
-				ret = 1;
-			}
+		if (in_range(physical_start, *start, len) ||
+		    in_range(*start, physical_start,
+			     physical_end - physical_start)) {
+			*start = physical_end + 1;
+			return true;
 		}
 	}
-	if (search_list != &fs_info->pinned_chunks) {
-		search_list = &fs_info->pinned_chunks;
-		goto again;
-	}
-
-	return ret;
+	return false;
 }
 
 
@@ -1332,10 +1542,16 @@
  * @len is used to store the size of the free space that we find.
  * But if we don't find suitable free space, it is used to store the size of
  * the max free space.
+ *
+ * NOTE: This function will search *commit* root of device tree, and does extra
+ * check to ensure dev extents are not double allocated.
+ * This makes the function safe to allocate dev extents but may not report
+ * correct usable device space, as device extent freed in current transaction
+ * is not reported as avaiable.
  */
-int find_free_dev_extent_start(struct btrfs_transaction *transaction,
-			       struct btrfs_device *device, u64 num_bytes,
-			       u64 search_start, u64 *start, u64 *len)
+static int find_free_dev_extent_start(struct btrfs_device *device,
+				u64 num_bytes, u64 search_start, u64 *start,
+				u64 *len)
 {
 	struct btrfs_fs_info *fs_info = device->fs_info;
 	struct btrfs_root *root = fs_info->dev_root;
@@ -1419,15 +1635,12 @@
 			 * Have to check before we set max_hole_start, otherwise
 			 * we could end up sending back this offset anyway.
 			 */
-			if (contains_pending_extent(transaction, device,
-						    &search_start,
+			if (contains_pending_extent(device, &search_start,
 						    hole_size)) {
-				if (key.offset >= search_start) {
+				if (key.offset >= search_start)
 					hole_size = key.offset - search_start;
-				} else {
-					WARN_ON_ONCE(1);
+				else
 					hole_size = 0;
-				}
 			}
 
 			if (hole_size > max_hole_size) {
@@ -1468,8 +1681,7 @@
 	if (search_end > search_start) {
 		hole_size = search_end - search_start;
 
-		if (contains_pending_extent(transaction, device, &search_start,
-					    hole_size)) {
+		if (contains_pending_extent(device, &search_start, hole_size)) {
 			btrfs_release_path(path);
 			goto again;
 		}
@@ -1494,13 +1706,11 @@
 	return ret;
 }
 
-int find_free_dev_extent(struct btrfs_trans_handle *trans,
-			 struct btrfs_device *device, u64 num_bytes,
+int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
 			 u64 *start, u64 *len)
 {
 	/* FIXME use last free of some kind */
-	return find_free_dev_extent_start(trans->transaction, device,
-					  num_bytes, 0, start, len);
+	return find_free_dev_extent_start(device, num_bytes, 0, start, len);
 }
 
 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
@@ -1611,9 +1821,9 @@
 	struct rb_node *n;
 	u64 ret = 0;
 
-	em_tree = &fs_info->mapping_tree.map_tree;
+	em_tree = &fs_info->mapping_tree;
 	read_lock(&em_tree->lock);
-	n = rb_last(&em_tree->map);
+	n = rb_last(&em_tree->map.rb_root);
 	if (n) {
 		em = rb_entry(n, struct extent_map, rb_node);
 		ret = em->start + em->len;
@@ -1643,7 +1853,12 @@
 	if (ret < 0)
 		goto error;
 
-	BUG_ON(ret == 0); /* Corruption */
+	if (ret == 0) {
+		/* Corruption */
+		btrfs_err(fs_info, "corrupted chunk tree devid -1 matched");
+		ret = -EUCLEAN;
+		goto error;
+	}
 
 	ret = btrfs_previous_item(fs_info->chunk_root, path,
 				  BTRFS_DEV_ITEMS_OBJECTID,
@@ -1709,7 +1924,8 @@
 	ptr = btrfs_device_uuid(dev_item);
 	write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
 	ptr = btrfs_device_fsid(dev_item);
-	write_extent_buffer(leaf, trans->fs_info->fsid, ptr, BTRFS_FSID_SIZE);
+	write_extent_buffer(leaf, trans->fs_info->fs_devices->metadata_uuid,
+			    ptr, BTRFS_FSID_SIZE);
 	btrfs_mark_buffer_dirty(leaf);
 
 	ret = 0;
@@ -1733,10 +1949,9 @@
 	filp_close(filp, NULL);
 }
 
-static int btrfs_rm_dev_item(struct btrfs_fs_info *fs_info,
-			     struct btrfs_device *device)
+static int btrfs_rm_dev_item(struct btrfs_device *device)
 {
-	struct btrfs_root *root = fs_info->chunk_root;
+	struct btrfs_root *root = device->fs_info->chunk_root;
 	int ret;
 	struct btrfs_path *path;
 	struct btrfs_key key;
@@ -1854,6 +2069,24 @@
 		fs_info->fs_devices->latest_bdev = next_device->bdev;
 }
 
+/*
+ * Return btrfs_fs_devices::num_devices excluding the device that's being
+ * currently replaced.
+ */
+static u64 btrfs_num_devices(struct btrfs_fs_info *fs_info)
+{
+	u64 num_devices = fs_info->fs_devices->num_devices;
+
+	down_read(&fs_info->dev_replace.rwsem);
+	if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
+		ASSERT(num_devices > 1);
+		num_devices--;
+	}
+	up_read(&fs_info->dev_replace.rwsem);
+
+	return num_devices;
+}
+
 int btrfs_rm_device(struct btrfs_fs_info *fs_info, const char *device_path,
 		u64 devid)
 {
@@ -1865,22 +2098,30 @@
 
 	mutex_lock(&uuid_mutex);
 
-	num_devices = fs_devices->num_devices;
-	btrfs_dev_replace_read_lock(&fs_info->dev_replace);
-	if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
-		WARN_ON(num_devices < 1);
-		num_devices--;
-	}
-	btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
+	num_devices = btrfs_num_devices(fs_info);
 
 	ret = btrfs_check_raid_min_devices(fs_info, num_devices - 1);
 	if (ret)
 		goto out;
 
-	ret = btrfs_find_device_by_devspec(fs_info, devid, device_path,
-					   &device);
-	if (ret)
+	device = btrfs_find_device_by_devspec(fs_info, devid, device_path);
+
+	if (IS_ERR(device)) {
+		if (PTR_ERR(device) == -ENOENT &&
+		    strcmp(device_path, "missing") == 0)
+			ret = BTRFS_ERROR_DEV_MISSING_NOT_FOUND;
+		else
+			ret = PTR_ERR(device);
 		goto out;
+	}
+
+	if (btrfs_pinned_by_swapfile(fs_info, device)) {
+		btrfs_warn_in_rcu(fs_info,
+		  "cannot remove device %s (devid %llu) due to active swapfile",
+				  rcu_str_deref(device->name), device->devid);
+		ret = -ETXTBSY;
+		goto out;
+	}
 
 	if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
 		ret = BTRFS_ERROR_DEV_TGT_REPLACE;
@@ -1911,12 +2152,12 @@
 	 * counter although write_all_supers() is not locked out. This
 	 * could give a filesystem state which requires a degraded mount.
 	 */
-	ret = btrfs_rm_dev_item(fs_info, device);
+	ret = btrfs_rm_dev_item(device);
 	if (ret)
 		goto error_undo;
 
 	clear_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
-	btrfs_scrub_cancel_dev(fs_info, device);
+	btrfs_scrub_cancel_dev(device);
 
 	/*
 	 * the device list mutex makes sure that we don't change
@@ -1967,7 +2208,8 @@
 		btrfs_scratch_superblocks(device->bdev, device->name->str);
 
 	btrfs_close_bdev(device);
-	call_rcu(&device->rcu, free_device_rcu);
+	synchronize_rcu();
+	btrfs_free_device(device);
 
 	if (cur_devices->open_devices == 0) {
 		while (fs_devices) {
@@ -2024,9 +2266,9 @@
 		fs_devices->open_devices--;
 }
 
-void btrfs_rm_dev_replace_free_srcdev(struct btrfs_fs_info *fs_info,
-				      struct btrfs_device *srcdev)
+void btrfs_rm_dev_replace_free_srcdev(struct btrfs_device *srcdev)
 {
+	struct btrfs_fs_info *fs_info = srcdev->fs_info;
 	struct btrfs_fs_devices *fs_devices = srcdev->fs_devices;
 
 	if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &srcdev->dev_state)) {
@@ -2035,7 +2277,8 @@
 	}
 
 	btrfs_close_bdev(srcdev);
-	call_rcu(&srcdev->rcu, free_device_rcu);
+	synchronize_rcu();
+	btrfs_free_device(srcdev);
 
 	/* if this is no devs we rather delete the fs_devices */
 	if (!fs_devices->num_devices) {
@@ -2093,12 +2336,12 @@
 	btrfs_scratch_superblocks(tgtdev->bdev, tgtdev->name->str);
 
 	btrfs_close_bdev(tgtdev);
-	call_rcu(&tgtdev->rcu, free_device_rcu);
+	synchronize_rcu();
+	btrfs_free_device(tgtdev);
 }
 
-static int btrfs_find_device_by_path(struct btrfs_fs_info *fs_info,
-				     const char *device_path,
-				     struct btrfs_device **device)
+static struct btrfs_device *btrfs_find_device_by_path(
+		struct btrfs_fs_info *fs_info, const char *device_path)
 {
 	int ret = 0;
 	struct btrfs_super_block *disk_super;
@@ -2106,72 +2349,61 @@
 	u8 *dev_uuid;
 	struct block_device *bdev;
 	struct buffer_head *bh;
+	struct btrfs_device *device;
 
-	*device = NULL;
 	ret = btrfs_get_bdev_and_sb(device_path, FMODE_READ,
 				    fs_info->bdev_holder, 0, &bdev, &bh);
 	if (ret)
-		return ret;
+		return ERR_PTR(ret);
 	disk_super = (struct btrfs_super_block *)bh->b_data;
 	devid = btrfs_stack_device_id(&disk_super->dev_item);
 	dev_uuid = disk_super->dev_item.uuid;
-	*device = btrfs_find_device(fs_info, devid, dev_uuid, disk_super->fsid);
+	if (btrfs_fs_incompat(fs_info, METADATA_UUID))
+		device = btrfs_find_device(fs_info->fs_devices, devid, dev_uuid,
+					   disk_super->metadata_uuid, true);
+	else
+		device = btrfs_find_device(fs_info->fs_devices, devid, dev_uuid,
+					   disk_super->fsid, true);
+
 	brelse(bh);
-	if (!*device)
-		ret = -ENOENT;
+	if (!device)
+		device = ERR_PTR(-ENOENT);
 	blkdev_put(bdev, FMODE_READ);
-	return ret;
-}
-
-int btrfs_find_device_missing_or_by_path(struct btrfs_fs_info *fs_info,
-					 const char *device_path,
-					 struct btrfs_device **device)
-{
-	*device = NULL;
-	if (strcmp(device_path, "missing") == 0) {
-		struct list_head *devices;
-		struct btrfs_device *tmp;
-
-		devices = &fs_info->fs_devices->devices;
-		list_for_each_entry(tmp, devices, dev_list) {
-			if (test_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
-					&tmp->dev_state) && !tmp->bdev) {
-				*device = tmp;
-				break;
-			}
-		}
-
-		if (!*device)
-			return BTRFS_ERROR_DEV_MISSING_NOT_FOUND;
-
-		return 0;
-	} else {
-		return btrfs_find_device_by_path(fs_info, device_path, device);
-	}
+	return device;
 }
 
 /*
  * Lookup a device given by device id, or the path if the id is 0.
  */
-int btrfs_find_device_by_devspec(struct btrfs_fs_info *fs_info, u64 devid,
-				 const char *devpath,
-				 struct btrfs_device **device)
+struct btrfs_device *btrfs_find_device_by_devspec(
+		struct btrfs_fs_info *fs_info, u64 devid,
+		const char *device_path)
 {
-	int ret;
+	struct btrfs_device *device;
 
 	if (devid) {
-		ret = 0;
-		*device = btrfs_find_device(fs_info, devid, NULL, NULL);
-		if (!*device)
-			ret = -ENOENT;
-	} else {
-		if (!devpath || !devpath[0])
-			return -EINVAL;
-
-		ret = btrfs_find_device_missing_or_by_path(fs_info, devpath,
-							   device);
+		device = btrfs_find_device(fs_info->fs_devices, devid, NULL,
+					   NULL, true);
+		if (!device)
+			return ERR_PTR(-ENOENT);
+		return device;
 	}
-	return ret;
+
+	if (!device_path || !device_path[0])
+		return ERR_PTR(-EINVAL);
+
+	if (strcmp(device_path, "missing") == 0) {
+		/* Find first missing device */
+		list_for_each_entry(device, &fs_info->fs_devices->devices,
+				    dev_list) {
+			if (test_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
+				     &device->dev_state) && !device->bdev)
+				return device;
+		}
+		return ERR_PTR(-ENOENT);
+	}
+
+	return btrfs_find_device_by_path(fs_info, device_path);
 }
 
 /*
@@ -2190,7 +2422,7 @@
 	if (!fs_devices->seeding)
 		return -EINVAL;
 
-	seed_devices = alloc_fs_devices(NULL);
+	seed_devices = alloc_fs_devices(NULL, NULL);
 	if (IS_ERR(seed_devices))
 		return PTR_ERR(seed_devices);
 
@@ -2226,7 +2458,7 @@
 	fs_devices->seed = seed_devices;
 
 	generate_random_uuid(fs_devices->fsid);
-	memcpy(fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
+	memcpy(fs_devices->metadata_uuid, fs_devices->fsid, BTRFS_FSID_SIZE);
 	memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
 	mutex_unlock(&fs_devices->device_list_mutex);
 
@@ -2240,9 +2472,9 @@
 /*
  * Store the expected generation for seed devices in device items.
  */
-static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
-			       struct btrfs_fs_info *fs_info)
+static int btrfs_finish_sprout(struct btrfs_trans_handle *trans)
 {
+	struct btrfs_fs_info *fs_info = trans->fs_info;
 	struct btrfs_root *root = fs_info->chunk_root;
 	struct btrfs_path *path;
 	struct extent_buffer *leaf;
@@ -2293,7 +2525,8 @@
 				   BTRFS_UUID_SIZE);
 		read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item),
 				   BTRFS_FSID_SIZE);
-		device = btrfs_find_device(fs_info, devid, dev_uuid, fs_uuid);
+		device = btrfs_find_device(fs_info->fs_devices, devid, dev_uuid,
+					   fs_uuid, true);
 		BUG_ON(!device); /* Logic error */
 
 		if (device->fs_devices->seeding) {
@@ -2441,7 +2674,7 @@
 
 	if (seeding_dev) {
 		mutex_lock(&fs_info->chunk_mutex);
-		ret = init_first_rw_device(trans, fs_info);
+		ret = init_first_rw_device(trans);
 		mutex_unlock(&fs_info->chunk_mutex);
 		if (ret) {
 			btrfs_abort_transaction(trans, ret);
@@ -2456,22 +2689,14 @@
 	}
 
 	if (seeding_dev) {
-		char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
-
-		ret = btrfs_finish_sprout(trans, fs_info);
+		ret = btrfs_finish_sprout(trans);
 		if (ret) {
 			btrfs_abort_transaction(trans, ret);
 			goto error_sysfs;
 		}
 
-		/* Sprouting would change fsid of the mounted root,
-		 * so rename the fsid on the sysfs
-		 */
-		snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU",
-						fs_info->fsid);
-		if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
-			btrfs_warn(fs_info,
-				   "sysfs: failed to create fsid for sprout");
+		btrfs_sysfs_update_sprout_fsid(fs_devices,
+				fs_info->fs_devices->fsid);
 	}
 
 	ret = btrfs_commit_transaction(trans);
@@ -2588,7 +2813,6 @@
 {
 	struct btrfs_fs_info *fs_info = device->fs_info;
 	struct btrfs_super_block *super_copy = fs_info->super_copy;
-	struct btrfs_fs_devices *fs_devices;
 	u64 old_total;
 	u64 diff;
 
@@ -2607,8 +2831,6 @@
 		return -EINVAL;
 	}
 
-	fs_devices = fs_info->fs_devices;
-
 	btrfs_set_super_total_bytes(super_copy,
 			round_down(old_total + diff, fs_info->sectorsize));
 	device->fs_devices->total_rw_bytes += diff;
@@ -2616,9 +2838,9 @@
 	btrfs_device_set_total_bytes(device, new_size);
 	btrfs_device_set_disk_total_bytes(device, new_size);
 	btrfs_clear_space_info_full(device->fs_info);
-	if (list_empty(&device->resized_list))
-		list_add_tail(&device->resized_list,
-			      &fs_devices->resized_devices);
+	if (list_empty(&device->post_commit_list))
+		list_add_tail(&device->post_commit_list,
+			      &trans->transaction->dev_update_list);
 	mutex_unlock(&fs_info->chunk_mutex);
 
 	return btrfs_update_device(trans, device);
@@ -2706,13 +2928,20 @@
 	return ret;
 }
 
-static struct extent_map *get_chunk_map(struct btrfs_fs_info *fs_info,
-					u64 logical, u64 length)
+/*
+ * btrfs_get_chunk_map() - Find the mapping containing the given logical extent.
+ * @logical: Logical block offset in bytes.
+ * @length: Length of extent in bytes.
+ *
+ * Return: Chunk mapping or ERR_PTR.
+ */
+struct extent_map *btrfs_get_chunk_map(struct btrfs_fs_info *fs_info,
+				       u64 logical, u64 length)
 {
 	struct extent_map_tree *em_tree;
 	struct extent_map *em;
 
-	em_tree = &fs_info->mapping_tree.map_tree;
+	em_tree = &fs_info->mapping_tree;
 	read_lock(&em_tree->lock);
 	em = lookup_extent_mapping(em_tree, logical, length);
 	read_unlock(&em_tree->lock);
@@ -2744,7 +2973,7 @@
 	int i, ret = 0;
 	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
 
-	em = get_chunk_map(fs_info, chunk_offset, 1);
+	em = btrfs_get_chunk_map(fs_info, chunk_offset, 1);
 	if (IS_ERR(em)) {
 		/*
 		 * This is a logic error, but we don't want to just rely on the
@@ -2785,13 +3014,11 @@
 			mutex_unlock(&fs_info->chunk_mutex);
 		}
 
-		if (map->stripes[i].dev) {
-			ret = btrfs_update_device(trans, map->stripes[i].dev);
-			if (ret) {
-				mutex_unlock(&fs_devices->device_list_mutex);
-				btrfs_abort_transaction(trans, ret);
-				goto out;
-			}
+		ret = btrfs_update_device(trans, device);
+		if (ret) {
+			mutex_unlock(&fs_devices->device_list_mutex);
+			btrfs_abort_transaction(trans, ret);
+			goto out;
 		}
 	}
 	mutex_unlock(&fs_devices->device_list_mutex);
@@ -2844,10 +3071,6 @@
 	 */
 	lockdep_assert_held(&fs_info->delete_unused_bgs_mutex);
 
-	ret = btrfs_can_relocate(fs_info, chunk_offset);
-	if (ret)
-		return -ENOSPC;
-
 	/* step one, relocate all the extents inside this chunk */
 	btrfs_scrub_pause(fs_info);
 	ret = btrfs_relocate_block_group(fs_info, chunk_offset);
@@ -2855,16 +3078,6 @@
 	if (ret)
 		return ret;
 
-	/*
-	 * We add the kobjects here (and after forcing data chunk creation)
-	 * since relocation is the only place we'll create chunks of a new
-	 * type at runtime.  The only place where we'll remove the last
-	 * chunk of a type is the call immediately below this one.  Even
-	 * so, we're protected against races with the cleaner thread since
-	 * we're covered by the delete_unused_bgs_mutex.
-	 */
-	btrfs_add_raid_kobjects(fs_info);
-
 	trans = btrfs_start_trans_remove_block_group(root->fs_info,
 						     chunk_offset);
 	if (IS_ERR(trans)) {
@@ -2991,9 +3204,6 @@
 			btrfs_end_transaction(trans);
 			if (ret < 0)
 				return ret;
-
-			btrfs_add_raid_kobjects(fs_info);
-
 			return 1;
 		}
 	}
@@ -3247,6 +3457,18 @@
 	return 1;
 }
 
+static u64 calc_data_stripes(u64 type, int num_stripes)
+{
+	const int index = btrfs_bg_flags_to_raid_index(type);
+	const int ncopies = btrfs_raid_array[index].ncopies;
+	const int nparity = btrfs_raid_array[index].nparity;
+
+	if (nparity)
+		return num_stripes - nparity;
+	else
+		return num_stripes / ncopies;
+}
+
 /* [pstart, pend) */
 static int chunk_drange_filter(struct extent_buffer *leaf,
 			       struct btrfs_chunk *chunk,
@@ -3256,22 +3478,15 @@
 	int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
 	u64 stripe_offset;
 	u64 stripe_length;
+	u64 type;
 	int factor;
 	int i;
 
 	if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
 		return 0;
 
-	if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
-	     BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)) {
-		factor = num_stripes / 2;
-	} else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID5) {
-		factor = num_stripes - 1;
-	} else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID6) {
-		factor = num_stripes - 2;
-	} else {
-		factor = num_stripes;
-	}
+	type = btrfs_chunk_type(leaf, chunk);
+	factor = calc_data_stripes(type, num_stripes);
 
 	for (i = 0; i < num_stripes; i++) {
 		stripe = btrfs_stripe_nr(chunk, i);
@@ -3332,10 +3547,10 @@
 	return 0;
 }
 
-static int should_balance_chunk(struct btrfs_fs_info *fs_info,
-				struct extent_buffer *leaf,
+static int should_balance_chunk(struct extent_buffer *leaf,
 				struct btrfs_chunk *chunk, u64 chunk_offset)
 {
+	struct btrfs_fs_info *fs_info = leaf->fs_info;
 	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
 	struct btrfs_balance_args *bargs = NULL;
 	u64 chunk_type = btrfs_chunk_type(leaf, chunk);
@@ -3425,17 +3640,11 @@
 {
 	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
 	struct btrfs_root *chunk_root = fs_info->chunk_root;
-	struct btrfs_root *dev_root = fs_info->dev_root;
-	struct list_head *devices;
-	struct btrfs_device *device;
-	u64 old_size;
-	u64 size_to_free;
 	u64 chunk_type;
 	struct btrfs_chunk *chunk;
 	struct btrfs_path *path = NULL;
 	struct btrfs_key key;
 	struct btrfs_key found_key;
-	struct btrfs_trans_handle *trans;
 	struct extent_buffer *leaf;
 	int slot;
 	int ret;
@@ -3450,53 +3659,6 @@
 	u32 count_sys = 0;
 	int chunk_reserved = 0;
 
-	/* step one make some room on all the devices */
-	devices = &fs_info->fs_devices->devices;
-	list_for_each_entry(device, devices, dev_list) {
-		old_size = btrfs_device_get_total_bytes(device);
-		size_to_free = div_factor(old_size, 1);
-		size_to_free = min_t(u64, size_to_free, SZ_1M);
-		if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) ||
-		    btrfs_device_get_total_bytes(device) -
-		    btrfs_device_get_bytes_used(device) > size_to_free ||
-		    test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state))
-			continue;
-
-		ret = btrfs_shrink_device(device, old_size - size_to_free);
-		if (ret == -ENOSPC)
-			break;
-		if (ret) {
-			/* btrfs_shrink_device never returns ret > 0 */
-			WARN_ON(ret > 0);
-			goto error;
-		}
-
-		trans = btrfs_start_transaction(dev_root, 0);
-		if (IS_ERR(trans)) {
-			ret = PTR_ERR(trans);
-			btrfs_info_in_rcu(fs_info,
-		 "resize: unable to start transaction after shrinking device %s (error %d), old size %llu, new size %llu",
-					  rcu_str_deref(device->name), ret,
-					  old_size, old_size - size_to_free);
-			goto error;
-		}
-
-		ret = btrfs_grow_device(trans, device, old_size);
-		if (ret) {
-			btrfs_end_transaction(trans);
-			/* btrfs_grow_device never returns ret > 0 */
-			WARN_ON(ret > 0);
-			btrfs_info_in_rcu(fs_info,
-		 "resize: unable to grow device after shrinking device %s (error %d), old size %llu, new size %llu",
-					  rcu_str_deref(device->name), ret,
-					  old_size, old_size - size_to_free);
-			goto error;
-		}
-
-		btrfs_end_transaction(trans);
-	}
-
-	/* step two, relocate all the chunks */
 	path = btrfs_alloc_path();
 	if (!path) {
 		ret = -ENOMEM;
@@ -3568,8 +3730,7 @@
 			spin_unlock(&fs_info->balance_lock);
 		}
 
-		ret = should_balance_chunk(fs_info, leaf, chunk,
-					   found_key.offset);
+		ret = should_balance_chunk(leaf, chunk, found_key.offset);
 
 		btrfs_release_path(path);
 		if (!ret) {
@@ -3626,10 +3787,15 @@
 
 		ret = btrfs_relocate_chunk(fs_info, found_key.offset);
 		mutex_unlock(&fs_info->delete_unused_bgs_mutex);
-		if (ret && ret != -ENOSPC)
-			goto error;
 		if (ret == -ENOSPC) {
 			enospc_errors++;
+		} else if (ret == -ETXTBSY) {
+			btrfs_info(fs_info,
+	   "skipping relocation of block group %llu due to active swapfile",
+				   found_key.offset);
+			ret = 0;
+		} else if (ret) {
+			goto error;
 		} else {
 			spin_lock(&fs_info->balance_lock);
 			bctl->stat.completed++;
@@ -3679,7 +3845,11 @@
 		return !extended; /* "0" is valid for usual profiles */
 
 	/* true if exactly one bit set */
-	return (flags & (flags - 1)) == 0;
+	/*
+	 * Don't use is_power_of_2(unsigned long) because it won't work
+	 * for the single profile (1ULL << 48) on 32-bit CPUs.
+	 */
+	return flags != 0 && (flags & (flags - 1)) == 0;
 }
 
 static inline int balance_need_close(struct btrfs_fs_info *fs_info)
@@ -3700,6 +3870,160 @@
 }
 
 /*
+ * Fill @buf with textual description of balance filter flags @bargs, up to
+ * @size_buf including the terminating null. The output may be trimmed if it
+ * does not fit into the provided buffer.
+ */
+static void describe_balance_args(struct btrfs_balance_args *bargs, char *buf,
+				 u32 size_buf)
+{
+	int ret;
+	u32 size_bp = size_buf;
+	char *bp = buf;
+	u64 flags = bargs->flags;
+	char tmp_buf[128] = {'\0'};
+
+	if (!flags)
+		return;
+
+#define CHECK_APPEND_NOARG(a)						\
+	do {								\
+		ret = snprintf(bp, size_bp, (a));			\
+		if (ret < 0 || ret >= size_bp)				\
+			goto out_overflow;				\
+		size_bp -= ret;						\
+		bp += ret;						\
+	} while (0)
+
+#define CHECK_APPEND_1ARG(a, v1)					\
+	do {								\
+		ret = snprintf(bp, size_bp, (a), (v1));			\
+		if (ret < 0 || ret >= size_bp)				\
+			goto out_overflow;				\
+		size_bp -= ret;						\
+		bp += ret;						\
+	} while (0)
+
+#define CHECK_APPEND_2ARG(a, v1, v2)					\
+	do {								\
+		ret = snprintf(bp, size_bp, (a), (v1), (v2));		\
+		if (ret < 0 || ret >= size_bp)				\
+			goto out_overflow;				\
+		size_bp -= ret;						\
+		bp += ret;						\
+	} while (0)
+
+	if (flags & BTRFS_BALANCE_ARGS_CONVERT)
+		CHECK_APPEND_1ARG("convert=%s,",
+				  btrfs_bg_type_to_raid_name(bargs->target));
+
+	if (flags & BTRFS_BALANCE_ARGS_SOFT)
+		CHECK_APPEND_NOARG("soft,");
+
+	if (flags & BTRFS_BALANCE_ARGS_PROFILES) {
+		btrfs_describe_block_groups(bargs->profiles, tmp_buf,
+					    sizeof(tmp_buf));
+		CHECK_APPEND_1ARG("profiles=%s,", tmp_buf);
+	}
+
+	if (flags & BTRFS_BALANCE_ARGS_USAGE)
+		CHECK_APPEND_1ARG("usage=%llu,", bargs->usage);
+
+	if (flags & BTRFS_BALANCE_ARGS_USAGE_RANGE)
+		CHECK_APPEND_2ARG("usage=%u..%u,",
+				  bargs->usage_min, bargs->usage_max);
+
+	if (flags & BTRFS_BALANCE_ARGS_DEVID)
+		CHECK_APPEND_1ARG("devid=%llu,", bargs->devid);
+
+	if (flags & BTRFS_BALANCE_ARGS_DRANGE)
+		CHECK_APPEND_2ARG("drange=%llu..%llu,",
+				  bargs->pstart, bargs->pend);
+
+	if (flags & BTRFS_BALANCE_ARGS_VRANGE)
+		CHECK_APPEND_2ARG("vrange=%llu..%llu,",
+				  bargs->vstart, bargs->vend);
+
+	if (flags & BTRFS_BALANCE_ARGS_LIMIT)
+		CHECK_APPEND_1ARG("limit=%llu,", bargs->limit);
+
+	if (flags & BTRFS_BALANCE_ARGS_LIMIT_RANGE)
+		CHECK_APPEND_2ARG("limit=%u..%u,",
+				bargs->limit_min, bargs->limit_max);
+
+	if (flags & BTRFS_BALANCE_ARGS_STRIPES_RANGE)
+		CHECK_APPEND_2ARG("stripes=%u..%u,",
+				  bargs->stripes_min, bargs->stripes_max);
+
+#undef CHECK_APPEND_2ARG
+#undef CHECK_APPEND_1ARG
+#undef CHECK_APPEND_NOARG
+
+out_overflow:
+
+	if (size_bp < size_buf)
+		buf[size_buf - size_bp - 1] = '\0'; /* remove last , */
+	else
+		buf[0] = '\0';
+}
+
+static void describe_balance_start_or_resume(struct btrfs_fs_info *fs_info)
+{
+	u32 size_buf = 1024;
+	char tmp_buf[192] = {'\0'};
+	char *buf;
+	char *bp;
+	u32 size_bp = size_buf;
+	int ret;
+	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
+
+	buf = kzalloc(size_buf, GFP_KERNEL);
+	if (!buf)
+		return;
+
+	bp = buf;
+
+#define CHECK_APPEND_1ARG(a, v1)					\
+	do {								\
+		ret = snprintf(bp, size_bp, (a), (v1));			\
+		if (ret < 0 || ret >= size_bp)				\
+			goto out_overflow;				\
+		size_bp -= ret;						\
+		bp += ret;						\
+	} while (0)
+
+	if (bctl->flags & BTRFS_BALANCE_FORCE)
+		CHECK_APPEND_1ARG("%s", "-f ");
+
+	if (bctl->flags & BTRFS_BALANCE_DATA) {
+		describe_balance_args(&bctl->data, tmp_buf, sizeof(tmp_buf));
+		CHECK_APPEND_1ARG("-d%s ", tmp_buf);
+	}
+
+	if (bctl->flags & BTRFS_BALANCE_METADATA) {
+		describe_balance_args(&bctl->meta, tmp_buf, sizeof(tmp_buf));
+		CHECK_APPEND_1ARG("-m%s ", tmp_buf);
+	}
+
+	if (bctl->flags & BTRFS_BALANCE_SYSTEM) {
+		describe_balance_args(&bctl->sys, tmp_buf, sizeof(tmp_buf));
+		CHECK_APPEND_1ARG("-s%s ", tmp_buf);
+	}
+
+#undef CHECK_APPEND_1ARG
+
+out_overflow:
+
+	if (size_bp < size_buf)
+		buf[size_buf - size_bp - 1] = '\0'; /* remove last " " */
+	btrfs_info(fs_info, "balance: %s %s",
+		   (bctl->flags & BTRFS_BALANCE_RESUME) ?
+		   "resume" : "start", buf);
+
+	kfree(buf);
+}
+
+/*
  * Should be called with balance mutexe held
  */
 int btrfs_balance(struct btrfs_fs_info *fs_info,
@@ -3712,6 +4036,8 @@
 	int ret;
 	u64 num_devices;
 	unsigned seq;
+	bool reducing_integrity;
+	int i;
 
 	if (btrfs_fs_closing(fs_info) ||
 	    atomic_read(&fs_info->balance_pause_req) ||
@@ -3740,54 +4066,50 @@
 		}
 	}
 
-	num_devices = fs_info->fs_devices->num_devices;
-	btrfs_dev_replace_read_lock(&fs_info->dev_replace);
-	if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
-		BUG_ON(num_devices < 1);
-		num_devices--;
-	}
-	btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
-	allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE | BTRFS_BLOCK_GROUP_DUP;
-	if (num_devices > 1)
-		allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
-	if (num_devices > 2)
-		allowed |= BTRFS_BLOCK_GROUP_RAID5;
-	if (num_devices > 3)
-		allowed |= (BTRFS_BLOCK_GROUP_RAID10 |
-			    BTRFS_BLOCK_GROUP_RAID6);
-	if (validate_convert_profile(&bctl->data, allowed)) {
-		int index = btrfs_bg_flags_to_raid_index(bctl->data.target);
+	num_devices = btrfs_num_devices(fs_info);
 
+	/*
+	 * SINGLE profile on-disk has no profile bit, but in-memory we have a
+	 * special bit for it, to make it easier to distinguish.  Thus we need
+	 * to set it manually, or balance would refuse the profile.
+	 */
+	allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
+	for (i = 0; i < ARRAY_SIZE(btrfs_raid_array); i++)
+		if (num_devices >= btrfs_raid_array[i].devs_min)
+			allowed |= btrfs_raid_array[i].bg_flag;
+
+	if (validate_convert_profile(&bctl->data, allowed)) {
 		btrfs_err(fs_info,
 			  "balance: invalid convert data profile %s",
-			  get_raid_name(index));
+			  btrfs_bg_type_to_raid_name(bctl->data.target));
 		ret = -EINVAL;
 		goto out;
 	}
 	if (validate_convert_profile(&bctl->meta, allowed)) {
-		int index = btrfs_bg_flags_to_raid_index(bctl->meta.target);
-
 		btrfs_err(fs_info,
 			  "balance: invalid convert metadata profile %s",
-			  get_raid_name(index));
+			  btrfs_bg_type_to_raid_name(bctl->meta.target));
 		ret = -EINVAL;
 		goto out;
 	}
 	if (validate_convert_profile(&bctl->sys, allowed)) {
-		int index = btrfs_bg_flags_to_raid_index(bctl->sys.target);
-
 		btrfs_err(fs_info,
 			  "balance: invalid convert system profile %s",
-			  get_raid_name(index));
+			  btrfs_bg_type_to_raid_name(bctl->sys.target));
 		ret = -EINVAL;
 		goto out;
 	}
 
-	/* allow to reduce meta or sys integrity only if force set */
-	allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
-			BTRFS_BLOCK_GROUP_RAID10 |
-			BTRFS_BLOCK_GROUP_RAID5 |
-			BTRFS_BLOCK_GROUP_RAID6;
+	/*
+	 * Allow to reduce metadata or system integrity only if force set for
+	 * profiles with redundancy (copies, parity)
+	 */
+	allowed = 0;
+	for (i = 0; i < ARRAY_SIZE(btrfs_raid_array); i++) {
+		if (btrfs_raid_array[i].ncopies >= 2 ||
+		    btrfs_raid_array[i].tolerated_failures >= 1)
+			allowed |= btrfs_raid_array[i].bg_flag;
+	}
 	do {
 		seq = read_seqbegin(&fs_info->profiles_lock);
 
@@ -3796,32 +4118,44 @@
 		     !(bctl->sys.target & allowed)) ||
 		    ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
 		     (fs_info->avail_metadata_alloc_bits & allowed) &&
-		     !(bctl->meta.target & allowed))) {
-			if (bctl->flags & BTRFS_BALANCE_FORCE) {
-				btrfs_info(fs_info,
-				"balance: force reducing metadata integrity");
-			} else {
-				btrfs_err(fs_info,
-	"balance: reduces metadata integrity, use --force if you want this");
-				ret = -EINVAL;
-				goto out;
-			}
-		}
+		     !(bctl->meta.target & allowed)))
+			reducing_integrity = true;
+		else
+			reducing_integrity = false;
+
+		/* if we're not converting, the target field is uninitialized */
+		meta_target = (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) ?
+			bctl->meta.target : fs_info->avail_metadata_alloc_bits;
+		data_target = (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) ?
+			bctl->data.target : fs_info->avail_data_alloc_bits;
 	} while (read_seqretry(&fs_info->profiles_lock, seq));
 
-	/* if we're not converting, the target field is uninitialized */
-	meta_target = (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) ?
-		bctl->meta.target : fs_info->avail_metadata_alloc_bits;
-	data_target = (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) ?
-		bctl->data.target : fs_info->avail_data_alloc_bits;
+	if (reducing_integrity) {
+		if (bctl->flags & BTRFS_BALANCE_FORCE) {
+			btrfs_info(fs_info,
+				   "balance: force reducing metadata integrity");
+		} else {
+			btrfs_err(fs_info,
+	  "balance: reduces metadata integrity, use --force if you want this");
+			ret = -EINVAL;
+			goto out;
+		}
+	}
+
 	if (btrfs_get_num_tolerated_disk_barrier_failures(meta_target) <
 		btrfs_get_num_tolerated_disk_barrier_failures(data_target)) {
-		int meta_index = btrfs_bg_flags_to_raid_index(meta_target);
-		int data_index = btrfs_bg_flags_to_raid_index(data_target);
-
 		btrfs_warn(fs_info,
 	"balance: metadata profile %s has lower redundancy than data profile %s",
-			   get_raid_name(meta_index), get_raid_name(data_index));
+				btrfs_bg_type_to_raid_name(meta_target),
+				btrfs_bg_type_to_raid_name(data_target));
+	}
+
+	if (fs_info->send_in_progress) {
+		btrfs_warn_rl(fs_info,
+"cannot run balance while send operations are in progress (%d in progress)",
+			      fs_info->send_in_progress);
+		ret = -EAGAIN;
+		goto out;
 	}
 
 	ret = insert_balance_item(fs_info, bctl);
@@ -3843,11 +4177,19 @@
 
 	ASSERT(!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
 	set_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags);
+	describe_balance_start_or_resume(fs_info);
 	mutex_unlock(&fs_info->balance_mutex);
 
 	ret = __btrfs_balance(fs_info);
 
 	mutex_lock(&fs_info->balance_mutex);
+	if (ret == -ECANCELED && atomic_read(&fs_info->balance_pause_req))
+		btrfs_info(fs_info, "balance: paused");
+	else if (ret == -ECANCELED && atomic_read(&fs_info->balance_cancel_req))
+		btrfs_info(fs_info, "balance: canceled");
+	else
+		btrfs_info(fs_info, "balance: ended with status: %d", ret);
+
 	clear_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags);
 
 	if (bargs) {
@@ -3880,10 +4222,8 @@
 	int ret = 0;
 
 	mutex_lock(&fs_info->balance_mutex);
-	if (fs_info->balance_ctl) {
-		btrfs_info(fs_info, "balance: resuming");
+	if (fs_info->balance_ctl)
 		ret = btrfs_balance(fs_info, fs_info->balance_ctl, NULL);
-	}
 	mutex_unlock(&fs_info->balance_mutex);
 
 	return ret;
@@ -4276,8 +4616,7 @@
 	if (IS_ERR(trans))
 		return PTR_ERR(trans);
 
-	uuid_root = btrfs_create_tree(trans, fs_info,
-				      BTRFS_UUID_TREE_OBJECTID);
+	uuid_root = btrfs_create_tree(trans, BTRFS_UUID_TREE_OBJECTID);
 	if (IS_ERR(uuid_root)) {
 		ret = PTR_ERR(uuid_root);
 		btrfs_abort_transaction(trans, ret);
@@ -4337,15 +4676,16 @@
 	int slot;
 	int failed = 0;
 	bool retried = false;
-	bool checked_pending_chunks = false;
 	struct extent_buffer *l;
 	struct btrfs_key key;
 	struct btrfs_super_block *super_copy = fs_info->super_copy;
 	u64 old_total = btrfs_super_total_bytes(super_copy);
 	u64 old_size = btrfs_device_get_total_bytes(device);
 	u64 diff;
+	u64 start;
 
 	new_size = round_down(new_size, fs_info->sectorsize);
+	start = new_size;
 	diff = round_down(old_size - new_size, fs_info->sectorsize);
 
 	if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state))
@@ -4357,6 +4697,12 @@
 
 	path->reada = READA_BACK;
 
+	trans = btrfs_start_transaction(root, 0);
+	if (IS_ERR(trans)) {
+		btrfs_free_path(path);
+		return PTR_ERR(trans);
+	}
+
 	mutex_lock(&fs_info->chunk_mutex);
 
 	btrfs_device_set_total_bytes(device, new_size);
@@ -4364,7 +4710,21 @@
 		device->fs_devices->total_rw_bytes -= diff;
 		atomic64_sub(diff, &fs_info->free_chunk_space);
 	}
-	mutex_unlock(&fs_info->chunk_mutex);
+
+	/*
+	 * Once the device's size has been set to the new size, ensure all
+	 * in-memory chunks are synced to disk so that the loop below sees them
+	 * and relocates them accordingly.
+	 */
+	if (contains_pending_extent(device, &start, diff)) {
+		mutex_unlock(&fs_info->chunk_mutex);
+		ret = btrfs_commit_transaction(trans);
+		if (ret)
+			goto done;
+	} else {
+		mutex_unlock(&fs_info->chunk_mutex);
+		btrfs_end_transaction(trans);
+	}
 
 again:
 	key.objectid = device->devid;
@@ -4426,10 +4786,16 @@
 
 		ret = btrfs_relocate_chunk(fs_info, chunk_offset);
 		mutex_unlock(&fs_info->delete_unused_bgs_mutex);
-		if (ret && ret != -ENOSPC)
-			goto done;
-		if (ret == -ENOSPC)
+		if (ret == -ENOSPC) {
 			failed++;
+		} else if (ret) {
+			if (ret == -ETXTBSY) {
+				btrfs_warn(fs_info,
+		   "could not shrink block group %llu due to active swapfile",
+					   chunk_offset);
+			}
+			goto done;
+		}
 	} while (key.offset-- > 0);
 
 	if (failed && !retried) {
@@ -4449,40 +4815,10 @@
 	}
 
 	mutex_lock(&fs_info->chunk_mutex);
-
-	/*
-	 * We checked in the above loop all device extents that were already in
-	 * the device tree. However before we have updated the device's
-	 * total_bytes to the new size, we might have had chunk allocations that
-	 * have not complete yet (new block groups attached to transaction
-	 * handles), and therefore their device extents were not yet in the
-	 * device tree and we missed them in the loop above. So if we have any
-	 * pending chunk using a device extent that overlaps the device range
-	 * that we can not use anymore, commit the current transaction and
-	 * repeat the search on the device tree - this way we guarantee we will
-	 * not have chunks using device extents that end beyond 'new_size'.
-	 */
-	if (!checked_pending_chunks) {
-		u64 start = new_size;
-		u64 len = old_size - new_size;
-
-		if (contains_pending_extent(trans->transaction, device,
-					    &start, len)) {
-			mutex_unlock(&fs_info->chunk_mutex);
-			checked_pending_chunks = true;
-			failed = 0;
-			retried = false;
-			ret = btrfs_commit_transaction(trans);
-			if (ret)
-				goto done;
-			goto again;
-		}
-	}
-
 	btrfs_device_set_disk_total_bytes(device, new_size);
-	if (list_empty(&device->resized_list))
-		list_add_tail(&device->resized_list,
-			      &fs_info->fs_devices->resized_devices);
+	if (list_empty(&device->post_commit_list))
+		list_add_tail(&device->post_commit_list,
+			      &trans->transaction->dev_update_list);
 
 	WARN_ON(diff > old_total);
 	btrfs_set_super_total_bytes(super_copy,
@@ -4566,15 +4902,6 @@
 	btrfs_set_fs_incompat(info, RAID56);
 }
 
-#define BTRFS_MAX_DEVS(info) ((BTRFS_MAX_ITEM_SIZE(info)	\
-			- sizeof(struct btrfs_chunk))		\
-			/ sizeof(struct btrfs_stripe) + 1)
-
-#define BTRFS_MAX_DEVS_SYS_CHUNK ((BTRFS_SYSTEM_CHUNK_ARRAY_SIZE	\
-				- 2 * sizeof(struct btrfs_disk_key)	\
-				- 2 * sizeof(struct btrfs_chunk))	\
-				/ sizeof(struct btrfs_stripe) + 1)
-
 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
 			       u64 start, u64 type)
 {
@@ -4595,11 +4922,13 @@
 	int devs_min;		/* min devs needed */
 	int devs_increment;	/* ndevs has to be a multiple of this */
 	int ncopies;		/* how many copies to data has */
+	int nparity;		/* number of stripes worth of bytes to
+				   store parity information */
 	int ret;
 	u64 max_stripe_size;
 	u64 max_chunk_size;
 	u64 stripe_size;
-	u64 num_bytes;
+	u64 chunk_size;
 	int ndevs;
 	int i;
 	int j;
@@ -4618,15 +4947,16 @@
 	sub_stripes = btrfs_raid_array[index].sub_stripes;
 	dev_stripes = btrfs_raid_array[index].dev_stripes;
 	devs_max = btrfs_raid_array[index].devs_max;
+	if (!devs_max)
+		devs_max = BTRFS_MAX_DEVS(info);
 	devs_min = btrfs_raid_array[index].devs_min;
 	devs_increment = btrfs_raid_array[index].devs_increment;
 	ncopies = btrfs_raid_array[index].ncopies;
+	nparity = btrfs_raid_array[index].nparity;
 
 	if (type & BTRFS_BLOCK_GROUP_DATA) {
 		max_stripe_size = SZ_1G;
 		max_chunk_size = BTRFS_MAX_DATA_CHUNK_SIZE;
-		if (!devs_max)
-			devs_max = BTRFS_MAX_DEVS(info);
 	} else if (type & BTRFS_BLOCK_GROUP_METADATA) {
 		/* for larger filesystems, use larger metadata chunks */
 		if (fs_devices->total_rw_bytes > 50ULL * SZ_1G)
@@ -4634,20 +4964,17 @@
 		else
 			max_stripe_size = SZ_256M;
 		max_chunk_size = max_stripe_size;
-		if (!devs_max)
-			devs_max = BTRFS_MAX_DEVS(info);
 	} else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
 		max_stripe_size = SZ_32M;
 		max_chunk_size = 2 * max_stripe_size;
-		if (!devs_max)
-			devs_max = BTRFS_MAX_DEVS_SYS_CHUNK;
+		devs_max = min_t(int, devs_max, BTRFS_MAX_DEVS_SYS_CHUNK);
 	} else {
 		btrfs_err(info, "invalid chunk type 0x%llx requested",
 		       type);
-		BUG_ON(1);
+		BUG();
 	}
 
-	/* we don't want a chunk larger than 10% of writeable space */
+	/* We don't want a chunk larger than 10% of writable space */
 	max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
 			     max_chunk_size);
 
@@ -4685,7 +5012,7 @@
 		if (total_avail == 0)
 			continue;
 
-		ret = find_free_dev_extent(trans, device,
+		ret = find_free_dev_extent(device,
 					   max_stripe_size * dev_stripes,
 					   &dev_offset, &max_avail);
 		if (ret && ret != -ENOSPC)
@@ -4750,30 +5077,22 @@
 	 * this will have to be fixed for RAID1 and RAID10 over
 	 * more drives
 	 */
-	data_stripes = num_stripes / ncopies;
-
-	if (type & BTRFS_BLOCK_GROUP_RAID5)
-		data_stripes = num_stripes - 1;
-
-	if (type & BTRFS_BLOCK_GROUP_RAID6)
-		data_stripes = num_stripes - 2;
+	data_stripes = (num_stripes - nparity) / ncopies;
 
 	/*
 	 * Use the number of data stripes to figure out how big this chunk
 	 * is really going to be in terms of logical address space,
-	 * and compare that answer with the max chunk size
+	 * and compare that answer with the max chunk size. If it's higher,
+	 * we try to reduce stripe_size.
 	 */
 	if (stripe_size * data_stripes > max_chunk_size) {
-		stripe_size = div_u64(max_chunk_size, data_stripes);
-
-		/* bump the answer up to a 16MB boundary */
-		stripe_size = round_up(stripe_size, SZ_16M);
-
 		/*
-		 * But don't go higher than the limits we found while searching
-		 * for free extents
+		 * Reduce stripe_size, round it up to a 16MB boundary again and
+		 * then use it, unless it ends up being even bigger than the
+		 * previous value we had already.
 		 */
-		stripe_size = min(devices_info[ndevs - 1].max_avail,
+		stripe_size = min(round_up(div_u64(max_chunk_size,
+						   data_stripes), SZ_16M),
 				  stripe_size);
 	}
 
@@ -4801,9 +5120,9 @@
 	map->type = type;
 	map->sub_stripes = sub_stripes;
 
-	num_bytes = stripe_size * data_stripes;
+	chunk_size = stripe_size * data_stripes;
 
-	trace_btrfs_chunk_alloc(info, map, start, num_bytes);
+	trace_btrfs_chunk_alloc(info, map, start, chunk_size);
 
 	em = alloc_extent_map();
 	if (!em) {
@@ -4814,12 +5133,12 @@
 	set_bit(EXTENT_FLAG_FS_MAPPING, &em->flags);
 	em->map_lookup = map;
 	em->start = start;
-	em->len = num_bytes;
+	em->len = chunk_size;
 	em->block_start = 0;
 	em->block_len = em->len;
 	em->orig_block_len = stripe_size;
 
-	em_tree = &info->mapping_tree.map_tree;
+	em_tree = &info->mapping_tree;
 	write_lock(&em_tree->lock);
 	ret = add_extent_mapping(em_tree, em, 0);
 	if (ret) {
@@ -4827,18 +5146,19 @@
 		free_extent_map(em);
 		goto error;
 	}
-
-	list_add_tail(&em->list, &trans->transaction->pending_chunks);
-	refcount_inc(&em->refs);
 	write_unlock(&em_tree->lock);
 
-	ret = btrfs_make_block_group(trans, 0, type, start, num_bytes);
+	ret = btrfs_make_block_group(trans, 0, type, start, chunk_size);
 	if (ret)
 		goto error_del_extent;
 
 	for (i = 0; i < map->num_stripes; i++) {
-		num_bytes = map->stripes[i].dev->bytes_used + stripe_size;
-		btrfs_device_set_bytes_used(map->stripes[i].dev, num_bytes);
+		struct btrfs_device *dev = map->stripes[i].dev;
+
+		btrfs_device_set_bytes_used(dev, dev->bytes_used + stripe_size);
+		if (list_empty(&dev->post_commit_list))
+			list_add_tail(&dev->post_commit_list,
+				      &trans->transaction->dev_update_list);
 	}
 
 	atomic64_sub(stripe_size * map->num_stripes, &info->free_chunk_space);
@@ -4858,8 +5178,6 @@
 	free_extent_map(em);
 	/* One for the tree reference */
 	free_extent_map(em);
-	/* One for the pending_chunks list reference */
-	free_extent_map(em);
 error:
 	kfree(devices_info);
 	return ret;
@@ -4883,7 +5201,7 @@
 	int i = 0;
 	int ret = 0;
 
-	em = get_chunk_map(fs_info, chunk_offset, chunk_size);
+	em = btrfs_get_chunk_map(fs_info, chunk_offset, chunk_size);
 	if (IS_ERR(em))
 		return PTR_ERR(em);
 
@@ -4964,10 +5282,10 @@
 }
 
 /*
- * Chunk allocation falls into two parts. The first part does works
- * that make the new allocated chunk useable, but not do any operation
- * that modifies the chunk tree. The second part does the works that
- * require modifying the chunk tree. This division is important for the
+ * Chunk allocation falls into two parts. The first part does work
+ * that makes the new allocated chunk usable, but does not do any operation
+ * that modifies the chunk tree. The second part does the work that
+ * requires modifying the chunk tree. This division is important for the
  * bootstrap process of adding storage to a seed btrfs.
  */
 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, u64 type)
@@ -4979,9 +5297,9 @@
 	return __btrfs_alloc_chunk(trans, chunk_offset, type);
 }
 
-static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
-					 struct btrfs_fs_info *fs_info)
+static noinline int init_first_rw_device(struct btrfs_trans_handle *trans)
 {
+	struct btrfs_fs_info *fs_info = trans->fs_info;
 	u64 chunk_offset;
 	u64 sys_chunk_offset;
 	u64 alloc_profile;
@@ -5001,20 +5319,9 @@
 
 static inline int btrfs_chunk_max_errors(struct map_lookup *map)
 {
-	int max_errors;
+	const int index = btrfs_bg_flags_to_raid_index(map->type);
 
-	if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
-			 BTRFS_BLOCK_GROUP_RAID10 |
-			 BTRFS_BLOCK_GROUP_RAID5 |
-			 BTRFS_BLOCK_GROUP_DUP)) {
-		max_errors = 1;
-	} else if (map->type & BTRFS_BLOCK_GROUP_RAID6) {
-		max_errors = 2;
-	} else {
-		max_errors = 0;
-	}
-
-	return max_errors;
+	return btrfs_raid_array[index].tolerated_failures;
 }
 
 int btrfs_chunk_readonly(struct btrfs_fs_info *fs_info, u64 chunk_offset)
@@ -5025,7 +5332,7 @@
 	int miss_ndevs = 0;
 	int i;
 
-	em = get_chunk_map(fs_info, chunk_offset, 1);
+	em = btrfs_get_chunk_map(fs_info, chunk_offset, 1);
 	if (IS_ERR(em))
 		return 1;
 
@@ -5055,21 +5362,16 @@
 	return readonly;
 }
 
-void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
-{
-	extent_map_tree_init(&tree->map_tree);
-}
-
-void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
+void btrfs_mapping_tree_free(struct extent_map_tree *tree)
 {
 	struct extent_map *em;
 
 	while (1) {
-		write_lock(&tree->map_tree.lock);
-		em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
+		write_lock(&tree->lock);
+		em = lookup_extent_mapping(tree, 0, (u64)-1);
 		if (em)
-			remove_extent_mapping(&tree->map_tree, em);
-		write_unlock(&tree->map_tree.lock);
+			remove_extent_mapping(tree, em);
+		write_unlock(&tree->lock);
 		if (!em)
 			break;
 		/* once for us */
@@ -5085,7 +5387,7 @@
 	struct map_lookup *map;
 	int ret;
 
-	em = get_chunk_map(fs_info, logical, len);
+	em = btrfs_get_chunk_map(fs_info, logical, len);
 	if (IS_ERR(em))
 		/*
 		 * We could return errors for these cases, but that could get
@@ -5096,7 +5398,7 @@
 		return 1;
 
 	map = em->map_lookup;
-	if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
+	if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1_MASK))
 		ret = map->num_stripes;
 	else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
 		ret = map->sub_stripes;
@@ -5115,11 +5417,11 @@
 		ret = 1;
 	free_extent_map(em);
 
-	btrfs_dev_replace_read_lock(&fs_info->dev_replace);
+	down_read(&fs_info->dev_replace.rwsem);
 	if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace) &&
 	    fs_info->dev_replace.tgtdev)
 		ret++;
-	btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
+	up_read(&fs_info->dev_replace.rwsem);
 
 	return ret;
 }
@@ -5131,7 +5433,7 @@
 	struct map_lookup *map;
 	unsigned long len = fs_info->sectorsize;
 
-	em = get_chunk_map(fs_info, logical, len);
+	em = btrfs_get_chunk_map(fs_info, logical, len);
 
 	if (!WARN_ON(IS_ERR(em))) {
 		map = em->map_lookup;
@@ -5148,7 +5450,7 @@
 	struct map_lookup *map;
 	int ret = 0;
 
-	em = get_chunk_map(fs_info, logical, len);
+	em = btrfs_get_chunk_map(fs_info, logical, len);
 
 	if(!WARN_ON(IS_ERR(em))) {
 		map = em->map_lookup;
@@ -5170,7 +5472,7 @@
 	struct btrfs_device *srcdev;
 
 	ASSERT((map->type &
-		 (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)));
+		 (BTRFS_BLOCK_GROUP_RAID1_MASK | BTRFS_BLOCK_GROUP_RAID10)));
 
 	if (map->type & BTRFS_BLOCK_GROUP_RAID10)
 		num_stripes = map->sub_stripes;
@@ -5307,7 +5609,7 @@
 	/* discard always return a bbio */
 	ASSERT(bbio_ret);
 
-	em = get_chunk_map(fs_info, logical, length);
+	em = btrfs_get_chunk_map(fs_info, logical, length);
 	if (IS_ERR(em))
 		return PTR_ERR(em);
 
@@ -5359,7 +5661,7 @@
 					      &remaining_stripes);
 		div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
 		last_stripe *= sub_stripes;
-	} else if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
+	} else if (map->type & (BTRFS_BLOCK_GROUP_RAID1_MASK |
 				BTRFS_BLOCK_GROUP_DUP)) {
 		num_stripes = map->num_stripes;
 	} else {
@@ -5603,6 +5905,106 @@
 	return (op == BTRFS_MAP_WRITE || op == BTRFS_MAP_GET_READ_MIRRORS);
 }
 
+/*
+ * btrfs_get_io_geometry - calculates the geomery of a particular (address, len)
+ *		       tuple. This information is used to calculate how big a
+ *		       particular bio can get before it straddles a stripe.
+ *
+ * @fs_info - the filesystem
+ * @logical - address that we want to figure out the geometry of
+ * @len	    - the length of IO we are going to perform, starting at @logical
+ * @op      - type of operation - write or read
+ * @io_geom - pointer used to return values
+ *
+ * Returns < 0 in case a chunk for the given logical address cannot be found,
+ * usually shouldn't happen unless @logical is corrupted, 0 otherwise.
+ */
+int btrfs_get_io_geometry(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
+			u64 logical, u64 len, struct btrfs_io_geometry *io_geom)
+{
+	struct extent_map *em;
+	struct map_lookup *map;
+	u64 offset;
+	u64 stripe_offset;
+	u64 stripe_nr;
+	u64 stripe_len;
+	u64 raid56_full_stripe_start = (u64)-1;
+	int data_stripes;
+	int ret = 0;
+
+	ASSERT(op != BTRFS_MAP_DISCARD);
+
+	em = btrfs_get_chunk_map(fs_info, logical, len);
+	if (IS_ERR(em))
+		return PTR_ERR(em);
+
+	map = em->map_lookup;
+	/* Offset of this logical address in the chunk */
+	offset = logical - em->start;
+	/* Len of a stripe in a chunk */
+	stripe_len = map->stripe_len;
+	/* Stripe wher this block falls in */
+	stripe_nr = div64_u64(offset, stripe_len);
+	/* Offset of stripe in the chunk */
+	stripe_offset = stripe_nr * stripe_len;
+	if (offset < stripe_offset) {
+		btrfs_crit(fs_info,
+"stripe math has gone wrong, stripe_offset=%llu offset=%llu start=%llu logical=%llu stripe_len=%llu",
+			stripe_offset, offset, em->start, logical, stripe_len);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* stripe_offset is the offset of this block in its stripe */
+	stripe_offset = offset - stripe_offset;
+	data_stripes = nr_data_stripes(map);
+
+	if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
+		u64 max_len = stripe_len - stripe_offset;
+
+		/*
+		 * In case of raid56, we need to know the stripe aligned start
+		 */
+		if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
+			unsigned long full_stripe_len = stripe_len * data_stripes;
+			raid56_full_stripe_start = offset;
+
+			/*
+			 * Allow a write of a full stripe, but make sure we
+			 * don't allow straddling of stripes
+			 */
+			raid56_full_stripe_start = div64_u64(raid56_full_stripe_start,
+					full_stripe_len);
+			raid56_full_stripe_start *= full_stripe_len;
+
+			/*
+			 * For writes to RAID[56], allow a full stripeset across
+			 * all disks. For other RAID types and for RAID[56]
+			 * reads, just allow a single stripe (on a single disk).
+			 */
+			if (op == BTRFS_MAP_WRITE) {
+				max_len = stripe_len * data_stripes -
+					  (offset - raid56_full_stripe_start);
+			}
+		}
+		len = min_t(u64, em->len - offset, max_len);
+	} else {
+		len = em->len - offset;
+	}
+
+	io_geom->len = len;
+	io_geom->offset = offset;
+	io_geom->stripe_len = stripe_len;
+	io_geom->stripe_nr = stripe_nr;
+	io_geom->stripe_offset = stripe_offset;
+	io_geom->raid56_stripe_offset = raid56_full_stripe_start;
+
+out:
+	/* once for us */
+	free_extent_map(em);
+	return ret;
+}
+
 static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
 			     enum btrfs_map_op op,
 			     u64 logical, u64 *length,
@@ -5611,11 +6013,11 @@
 {
 	struct extent_map *em;
 	struct map_lookup *map;
-	u64 offset;
 	u64 stripe_offset;
 	u64 stripe_nr;
 	u64 stripe_len;
 	u32 stripe_index;
+	int data_stripes;
 	int i;
 	int ret = 0;
 	int num_stripes;
@@ -5628,81 +6030,37 @@
 	int patch_the_first_stripe_for_dev_replace = 0;
 	u64 physical_to_patch_in_first_stripe = 0;
 	u64 raid56_full_stripe_start = (u64)-1;
+	struct btrfs_io_geometry geom;
+
+	ASSERT(bbio_ret);
 
 	if (op == BTRFS_MAP_DISCARD)
 		return __btrfs_map_block_for_discard(fs_info, logical,
 						     *length, bbio_ret);
 
-	em = get_chunk_map(fs_info, logical, *length);
-	if (IS_ERR(em))
-		return PTR_ERR(em);
+	ret = btrfs_get_io_geometry(fs_info, op, logical, *length, &geom);
+	if (ret < 0)
+		return ret;
 
+	em = btrfs_get_chunk_map(fs_info, logical, *length);
+	ASSERT(!IS_ERR(em));
 	map = em->map_lookup;
-	offset = logical - em->start;
 
-	stripe_len = map->stripe_len;
-	stripe_nr = offset;
-	/*
-	 * stripe_nr counts the total number of stripes we have to stride
-	 * to get to this block
-	 */
-	stripe_nr = div64_u64(stripe_nr, stripe_len);
+	*length = geom.len;
+	stripe_len = geom.stripe_len;
+	stripe_nr = geom.stripe_nr;
+	stripe_offset = geom.stripe_offset;
+	raid56_full_stripe_start = geom.raid56_stripe_offset;
+	data_stripes = nr_data_stripes(map);
 
-	stripe_offset = stripe_nr * stripe_len;
-	if (offset < stripe_offset) {
-		btrfs_crit(fs_info,
-			   "stripe math has gone wrong, stripe_offset=%llu, offset=%llu, start=%llu, logical=%llu, stripe_len=%llu",
-			   stripe_offset, offset, em->start, logical,
-			   stripe_len);
-		free_extent_map(em);
-		return -EINVAL;
-	}
-
-	/* stripe_offset is the offset of this block in its stripe*/
-	stripe_offset = offset - stripe_offset;
-
-	/* if we're here for raid56, we need to know the stripe aligned start */
-	if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
-		unsigned long full_stripe_len = stripe_len * nr_data_stripes(map);
-		raid56_full_stripe_start = offset;
-
-		/* allow a write of a full stripe, but make sure we don't
-		 * allow straddling of stripes
-		 */
-		raid56_full_stripe_start = div64_u64(raid56_full_stripe_start,
-				full_stripe_len);
-		raid56_full_stripe_start *= full_stripe_len;
-	}
-
-	if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
-		u64 max_len;
-		/* For writes to RAID[56], allow a full stripeset across all disks.
-		   For other RAID types and for RAID[56] reads, just allow a single
-		   stripe (on a single disk). */
-		if ((map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) &&
-		    (op == BTRFS_MAP_WRITE)) {
-			max_len = stripe_len * nr_data_stripes(map) -
-				(offset - raid56_full_stripe_start);
-		} else {
-			/* we limit the length of each bio to what fits in a stripe */
-			max_len = stripe_len - stripe_offset;
-		}
-		*length = min_t(u64, em->len - offset, max_len);
-	} else {
-		*length = em->len - offset;
-	}
-
-	/* This is for when we're called from btrfs_merge_bio_hook() and all
-	   it cares about is the length */
-	if (!bbio_ret)
-		goto out;
-
-	btrfs_dev_replace_read_lock(dev_replace);
+	down_read(&dev_replace->rwsem);
 	dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);
+	/*
+	 * Hold the semaphore for read during the whole operation, write is
+	 * requested at commit time but must wait.
+	 */
 	if (!dev_replace_is_ongoing)
-		btrfs_dev_replace_read_unlock(dev_replace);
-	else
-		btrfs_dev_replace_set_lock_blocking(dev_replace);
+		up_read(&dev_replace->rwsem);
 
 	if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 &&
 	    !need_full_stripe(op) && dev_replace->tgtdev != NULL) {
@@ -5725,7 +6083,7 @@
 				&stripe_index);
 		if (!need_full_stripe(op))
 			mirror_num = 1;
-	} else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
+	} else if (map->type & BTRFS_BLOCK_GROUP_RAID1_MASK) {
 		if (need_full_stripe(op))
 			num_stripes = map->num_stripes;
 		else if (mirror_num)
@@ -5767,7 +6125,7 @@
 		if (need_raid_map && (need_full_stripe(op) || mirror_num > 1)) {
 			/* push stripe_nr back to the start of the full stripe */
 			stripe_nr = div64_u64(raid56_full_stripe_start,
-					stripe_len * nr_data_stripes(map));
+					stripe_len * data_stripes);
 
 			/* RAID[56] write or recovery. Return all stripes */
 			num_stripes = map->num_stripes;
@@ -5783,10 +6141,9 @@
 			 * Mirror #3 is RAID6 Q block.
 			 */
 			stripe_nr = div_u64_rem(stripe_nr,
-					nr_data_stripes(map), &stripe_index);
+					data_stripes, &stripe_index);
 			if (mirror_num > 1)
-				stripe_index = nr_data_stripes(map) +
-						mirror_num - 2;
+				stripe_index = data_stripes + mirror_num - 2;
 
 			/* We distribute the parity blocks across stripes */
 			div_u64_rem(stripe_nr + stripe_index, map->num_stripes,
@@ -5844,8 +6201,8 @@
 		div_u64_rem(stripe_nr, num_stripes, &rot);
 
 		/* Fill in the logical address of each stripe */
-		tmp = stripe_nr * nr_data_stripes(map);
-		for (i = 0; i < nr_data_stripes(map); i++)
+		tmp = stripe_nr * data_stripes;
+		for (i = 0; i < data_stripes; i++)
 			bbio->raid_map[(i+rot) % num_stripes] =
 				em->start + (tmp + i) * map->stripe_len;
 
@@ -5897,8 +6254,9 @@
 	}
 out:
 	if (dev_replace_is_ongoing) {
-		btrfs_dev_replace_clear_lock_blocking(dev_replace);
-		btrfs_dev_replace_read_unlock(dev_replace);
+		lockdep_assert_held(&dev_replace->rwsem);
+		/* Unlock and let waiting writers proceed */
+		up_read(&dev_replace->rwsem);
 	}
 	free_extent_map(em);
 	return ret;
@@ -5932,7 +6290,7 @@
 	u64 rmap_len;
 	int i, j, nr = 0;
 
-	em = get_chunk_map(fs_info, chunk_start, 1);
+	em = btrfs_get_chunk_map(fs_info, chunk_start, 1);
 	if (IS_ERR(em))
 		return -EIO;
 
@@ -6017,7 +6375,7 @@
 				if (bio_op(bio) == REQ_OP_WRITE)
 					btrfs_dev_stat_inc_and_print(dev,
 						BTRFS_DEV_STAT_WRITE_ERRS);
-				else
+				else if (!(bio->bi_opf & REQ_RAHEAD))
 					btrfs_dev_stat_inc_and_print(dev,
 						BTRFS_DEV_STAT_READ_ERRS);
 				if (bio->bi_opf & REQ_PREFLUSH)
@@ -6072,12 +6430,6 @@
 	int should_queue = 1;
 	struct btrfs_pending_bios *pending_bios;
 
-	if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state) ||
-	    !device->bdev) {
-		bio_io_error(bio);
-		return;
-	}
-
 	/* don't bother with additional async steps for reads, right now */
 	if (bio_op(bio) == REQ_OP_READ) {
 		btrfsic_submit_bio(bio);
@@ -6206,7 +6558,8 @@
 
 	for (dev_nr = 0; dev_nr < total_devs; dev_nr++) {
 		dev = bbio->stripes[dev_nr].dev;
-		if (!dev || !dev->bdev ||
+		if (!dev || !dev->bdev || test_bit(BTRFS_DEV_STATE_MISSING,
+						   &dev->dev_state) ||
 		    (bio_op(first_bio) == REQ_OP_WRITE &&
 		    !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))) {
 			bbio_error(bbio, first_bio, logical);
@@ -6225,21 +6578,36 @@
 	return BLK_STS_OK;
 }
 
-struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
-				       u8 *uuid, u8 *fsid)
+/*
+ * Find a device specified by @devid or @uuid in the list of @fs_devices, or
+ * return NULL.
+ *
+ * If devid and uuid are both specified, the match must be exact, otherwise
+ * only devid is used.
+ *
+ * If @seed is true, traverse through the seed devices.
+ */
+struct btrfs_device *btrfs_find_device(struct btrfs_fs_devices *fs_devices,
+				       u64 devid, u8 *uuid, u8 *fsid,
+				       bool seed)
 {
 	struct btrfs_device *device;
-	struct btrfs_fs_devices *cur_devices;
 
-	cur_devices = fs_info->fs_devices;
-	while (cur_devices) {
+	while (fs_devices) {
 		if (!fsid ||
-		    !memcmp(cur_devices->fsid, fsid, BTRFS_FSID_SIZE)) {
-			device = find_device(cur_devices, devid, uuid);
-			if (device)
-				return device;
+		    !memcmp(fs_devices->metadata_uuid, fsid, BTRFS_FSID_SIZE)) {
+			list_for_each_entry(device, &fs_devices->devices,
+					    dev_list) {
+				if (device->devid == devid &&
+				    (!uuid || memcmp(device->uuid, uuid,
+						     BTRFS_UUID_SIZE) == 0))
+					return device;
+			}
 		}
-		cur_devices = cur_devices->seed;
+		if (seed)
+			fs_devices = fs_devices->seed;
+		else
+			return NULL;
 	}
 	return NULL;
 }
@@ -6314,99 +6682,6 @@
 	return dev;
 }
 
-/* Return -EIO if any error, otherwise return 0. */
-static int btrfs_check_chunk_valid(struct btrfs_fs_info *fs_info,
-				   struct extent_buffer *leaf,
-				   struct btrfs_chunk *chunk, u64 logical)
-{
-	u64 length;
-	u64 stripe_len;
-	u16 num_stripes;
-	u16 sub_stripes;
-	u64 type;
-	u64 features;
-	bool mixed = false;
-
-	length = btrfs_chunk_length(leaf, chunk);
-	stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
-	num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
-	sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
-	type = btrfs_chunk_type(leaf, chunk);
-
-	if (!num_stripes) {
-		btrfs_err(fs_info, "invalid chunk num_stripes: %u",
-			  num_stripes);
-		return -EIO;
-	}
-	if (!IS_ALIGNED(logical, fs_info->sectorsize)) {
-		btrfs_err(fs_info, "invalid chunk logical %llu", logical);
-		return -EIO;
-	}
-	if (btrfs_chunk_sector_size(leaf, chunk) != fs_info->sectorsize) {
-		btrfs_err(fs_info, "invalid chunk sectorsize %u",
-			  btrfs_chunk_sector_size(leaf, chunk));
-		return -EIO;
-	}
-	if (!length || !IS_ALIGNED(length, fs_info->sectorsize)) {
-		btrfs_err(fs_info, "invalid chunk length %llu", length);
-		return -EIO;
-	}
-	if (!is_power_of_2(stripe_len) || stripe_len != BTRFS_STRIPE_LEN) {
-		btrfs_err(fs_info, "invalid chunk stripe length: %llu",
-			  stripe_len);
-		return -EIO;
-	}
-	if (~(BTRFS_BLOCK_GROUP_TYPE_MASK | BTRFS_BLOCK_GROUP_PROFILE_MASK) &
-	    type) {
-		btrfs_err(fs_info, "unrecognized chunk type: %llu",
-			  ~(BTRFS_BLOCK_GROUP_TYPE_MASK |
-			    BTRFS_BLOCK_GROUP_PROFILE_MASK) &
-			  btrfs_chunk_type(leaf, chunk));
-		return -EIO;
-	}
-
-	if ((type & BTRFS_BLOCK_GROUP_TYPE_MASK) == 0) {
-		btrfs_err(fs_info, "missing chunk type flag: 0x%llx", type);
-		return -EIO;
-	}
-
-	if ((type & BTRFS_BLOCK_GROUP_SYSTEM) &&
-	    (type & (BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA))) {
-		btrfs_err(fs_info,
-			"system chunk with data or metadata type: 0x%llx", type);
-		return -EIO;
-	}
-
-	features = btrfs_super_incompat_flags(fs_info->super_copy);
-	if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
-		mixed = true;
-
-	if (!mixed) {
-		if ((type & BTRFS_BLOCK_GROUP_METADATA) &&
-		    (type & BTRFS_BLOCK_GROUP_DATA)) {
-			btrfs_err(fs_info,
-			"mixed chunk type in non-mixed mode: 0x%llx", type);
-			return -EIO;
-		}
-	}
-
-	if ((type & BTRFS_BLOCK_GROUP_RAID10 && sub_stripes != 2) ||
-	    (type & BTRFS_BLOCK_GROUP_RAID1 && num_stripes < 1) ||
-	    (type & BTRFS_BLOCK_GROUP_RAID5 && num_stripes < 2) ||
-	    (type & BTRFS_BLOCK_GROUP_RAID6 && num_stripes < 3) ||
-	    (type & BTRFS_BLOCK_GROUP_DUP && num_stripes > 2) ||
-	    ((type & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 &&
-	     num_stripes != 1)) {
-		btrfs_err(fs_info,
-			"invalid num_stripes:sub_stripes %u:%u for profile %llu",
-			num_stripes, sub_stripes,
-			type & BTRFS_BLOCK_GROUP_PROFILE_MASK);
-		return -EIO;
-	}
-
-	return 0;
-}
-
 static void btrfs_report_missing_device(struct btrfs_fs_info *fs_info,
 					u64 devid, u8 *uuid, bool error)
 {
@@ -6418,11 +6693,31 @@
 			      devid, uuid);
 }
 
-static int read_one_chunk(struct btrfs_fs_info *fs_info, struct btrfs_key *key,
-			  struct extent_buffer *leaf,
+static u64 calc_stripe_length(u64 type, u64 chunk_len, int num_stripes)
+{
+	int index = btrfs_bg_flags_to_raid_index(type);
+	int ncopies = btrfs_raid_array[index].ncopies;
+	int data_stripes;
+
+	switch (type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
+	case BTRFS_BLOCK_GROUP_RAID5:
+		data_stripes = num_stripes - 1;
+		break;
+	case BTRFS_BLOCK_GROUP_RAID6:
+		data_stripes = num_stripes - 2;
+		break;
+	default:
+		data_stripes = num_stripes / ncopies;
+		break;
+	}
+	return div_u64(chunk_len, data_stripes);
+}
+
+static int read_one_chunk(struct btrfs_key *key, struct extent_buffer *leaf,
 			  struct btrfs_chunk *chunk)
 {
-	struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
+	struct btrfs_fs_info *fs_info = leaf->fs_info;
+	struct extent_map_tree *map_tree = &fs_info->mapping_tree;
 	struct map_lookup *map;
 	struct extent_map *em;
 	u64 logical;
@@ -6437,13 +6732,19 @@
 	length = btrfs_chunk_length(leaf, chunk);
 	num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
 
-	ret = btrfs_check_chunk_valid(fs_info, leaf, chunk, logical);
-	if (ret)
-		return ret;
+	/*
+	 * Only need to verify chunk item if we're reading from sys chunk array,
+	 * as chunk item in tree block is already verified by tree-checker.
+	 */
+	if (leaf->start == BTRFS_SUPER_INFO_OFFSET) {
+		ret = btrfs_check_chunk_valid(leaf, chunk, logical);
+		if (ret)
+			return ret;
+	}
 
-	read_lock(&map_tree->map_tree.lock);
-	em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
-	read_unlock(&map_tree->map_tree.lock);
+	read_lock(&map_tree->lock);
+	em = lookup_extent_mapping(map_tree, logical, 1);
+	read_unlock(&map_tree->lock);
 
 	/* already mapped? */
 	if (em && em->start <= logical && em->start + em->len > logical) {
@@ -6477,6 +6778,8 @@
 	map->type = btrfs_chunk_type(leaf, chunk);
 	map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
 	map->verified_stripes = 0;
+	em->orig_block_len = calc_stripe_length(map->type, em->len,
+						map->num_stripes);
 	for (i = 0; i < num_stripes; i++) {
 		map->stripes[i].physical =
 			btrfs_stripe_offset_nr(leaf, chunk, i);
@@ -6484,8 +6787,8 @@
 		read_extent_buffer(leaf, uuid, (unsigned long)
 				   btrfs_stripe_dev_uuid_nr(chunk, i),
 				   BTRFS_UUID_SIZE);
-		map->stripes[i].dev = btrfs_find_device(fs_info, devid,
-							uuid, NULL);
+		map->stripes[i].dev = btrfs_find_device(fs_info->fs_devices,
+							devid, uuid, NULL, true);
 		if (!map->stripes[i].dev &&
 		    !btrfs_test_opt(fs_info, DEGRADED)) {
 			free_extent_map(em);
@@ -6510,9 +6813,9 @@
 
 	}
 
-	write_lock(&map_tree->map_tree.lock);
-	ret = add_extent_mapping(&map_tree->map_tree, em, 0);
-	write_unlock(&map_tree->map_tree.lock);
+	write_lock(&map_tree->lock);
+	ret = add_extent_mapping(map_tree, em, 0);
+	write_unlock(&map_tree->lock);
 	if (ret < 0) {
 		btrfs_err(fs_info,
 			  "failed to add chunk map, start=%llu len=%llu: %d",
@@ -6563,12 +6866,12 @@
 		fs_devices = fs_devices->seed;
 	}
 
-	fs_devices = find_fsid(fsid);
+	fs_devices = find_fsid(fsid, NULL);
 	if (!fs_devices) {
 		if (!btrfs_test_opt(fs_info, DEGRADED))
 			return ERR_PTR(-ENOENT);
 
-		fs_devices = alloc_fs_devices(fsid);
+		fs_devices = alloc_fs_devices(fsid, NULL);
 		if (IS_ERR(fs_devices))
 			return fs_devices;
 
@@ -6601,10 +6904,10 @@
 	return fs_devices;
 }
 
-static int read_one_dev(struct btrfs_fs_info *fs_info,
-			struct extent_buffer *leaf,
+static int read_one_dev(struct extent_buffer *leaf,
 			struct btrfs_dev_item *dev_item)
 {
+	struct btrfs_fs_info *fs_info = leaf->fs_info;
 	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
 	struct btrfs_device *device;
 	u64 devid;
@@ -6618,13 +6921,14 @@
 	read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item),
 			   BTRFS_FSID_SIZE);
 
-	if (memcmp(fs_uuid, fs_info->fsid, BTRFS_FSID_SIZE)) {
+	if (memcmp(fs_uuid, fs_devices->metadata_uuid, BTRFS_FSID_SIZE)) {
 		fs_devices = open_seed_devices(fs_info, fs_uuid);
 		if (IS_ERR(fs_devices))
 			return PTR_ERR(fs_devices);
 	}
 
-	device = btrfs_find_device(fs_info, devid, dev_uuid, fs_uuid);
+	device = btrfs_find_device(fs_info->fs_devices, devid, dev_uuid,
+				   fs_uuid, true);
 	if (!device) {
 		if (!btrfs_test_opt(fs_info, DEGRADED)) {
 			btrfs_report_missing_device(fs_info, devid,
@@ -6792,7 +7096,7 @@
 			if (cur_offset + len > array_size)
 				goto out_short_read;
 
-			ret = read_one_chunk(fs_info, &key, sb, chunk);
+			ret = read_one_chunk(&key, sb, chunk);
 			if (ret)
 				break;
 		} else {
@@ -6829,14 +7133,14 @@
 bool btrfs_check_rw_degradable(struct btrfs_fs_info *fs_info,
 					struct btrfs_device *failing_dev)
 {
-	struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
+	struct extent_map_tree *map_tree = &fs_info->mapping_tree;
 	struct extent_map *em;
 	u64 next_start = 0;
 	bool ret = true;
 
-	read_lock(&map_tree->map_tree.lock);
-	em = lookup_extent_mapping(&map_tree->map_tree, 0, (u64)-1);
-	read_unlock(&map_tree->map_tree.lock);
+	read_lock(&map_tree->lock);
+	em = lookup_extent_mapping(map_tree, 0, (u64)-1);
+	read_unlock(&map_tree->lock);
 	/* No chunk at all? Return false anyway */
 	if (!em) {
 		ret = false;
@@ -6865,7 +7169,7 @@
 		if (missing > max_tolerated) {
 			if (!failing_dev)
 				btrfs_warn(fs_info,
-	"chunk %llu missing %d devices, max tolerance is %d for writeable mount",
+	"chunk %llu missing %d devices, max tolerance is %d for writable mount",
 				   em->start, missing, max_tolerated);
 			free_extent_map(em);
 			ret = false;
@@ -6874,10 +7178,10 @@
 		next_start = extent_map_end(em);
 		free_extent_map(em);
 
-		read_lock(&map_tree->map_tree.lock);
-		em = lookup_extent_mapping(&map_tree->map_tree, next_start,
+		read_lock(&map_tree->lock);
+		em = lookup_extent_mapping(map_tree, next_start,
 					   (u64)(-1) - next_start);
-		read_unlock(&map_tree->map_tree.lock);
+		read_unlock(&map_tree->lock);
 	}
 out:
 	return ret;
@@ -6933,14 +7237,14 @@
 			struct btrfs_dev_item *dev_item;
 			dev_item = btrfs_item_ptr(leaf, slot,
 						  struct btrfs_dev_item);
-			ret = read_one_dev(fs_info, leaf, dev_item);
+			ret = read_one_dev(leaf, dev_item);
 			if (ret)
 				goto error;
 			total_dev++;
 		} else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
 			struct btrfs_chunk *chunk;
 			chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
-			ret = read_one_chunk(fs_info, &found_key, leaf, chunk);
+			ret = read_one_chunk(&found_key, leaf, chunk);
 			if (ret)
 				goto error;
 		}
@@ -6992,18 +7296,32 @@
 	}
 }
 
-static void __btrfs_reset_dev_stats(struct btrfs_device *dev)
+static u64 btrfs_dev_stats_value(const struct extent_buffer *eb,
+				 const struct btrfs_dev_stats_item *ptr,
+				 int index)
 {
-	int i;
+	u64 val;
 
-	for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
-		btrfs_dev_stat_reset(dev, i);
+	read_extent_buffer(eb, &val,
+			   offsetof(struct btrfs_dev_stats_item, values) +
+			    ((unsigned long)ptr) + (index * sizeof(u64)),
+			   sizeof(val));
+	return val;
+}
+
+static void btrfs_set_dev_stats_value(struct extent_buffer *eb,
+				      struct btrfs_dev_stats_item *ptr,
+				      int index, u64 val)
+{
+	write_extent_buffer(eb, &val,
+			    offsetof(struct btrfs_dev_stats_item, values) +
+			     ((unsigned long)ptr) + (index * sizeof(u64)),
+			    sizeof(val));
 }
 
 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
 {
 	struct btrfs_key key;
-	struct btrfs_key found_key;
 	struct btrfs_root *dev_root = fs_info->dev_root;
 	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
 	struct extent_buffer *eb;
@@ -7014,10 +7332,8 @@
 	int i;
 
 	path = btrfs_alloc_path();
-	if (!path) {
-		ret = -ENOMEM;
-		goto out;
-	}
+	if (!path)
+		return -ENOMEM;
 
 	mutex_lock(&fs_devices->device_list_mutex);
 	list_for_each_entry(device, &fs_devices->devices, dev_list) {
@@ -7029,14 +7345,14 @@
 		key.offset = device->devid;
 		ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
 		if (ret) {
-			__btrfs_reset_dev_stats(device);
+			for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
+				btrfs_dev_stat_set(device, i, 0);
 			device->dev_stats_valid = 1;
 			btrfs_release_path(path);
 			continue;
 		}
 		slot = path->slots[0];
 		eb = path->nodes[0];
-		btrfs_item_key_to_cpu(eb, &found_key, slot);
 		item_size = btrfs_item_size_nr(eb, slot);
 
 		ptr = btrfs_item_ptr(eb, slot,
@@ -7047,7 +7363,7 @@
 				btrfs_dev_stat_set(device, i,
 					btrfs_dev_stats_value(eb, ptr, i));
 			else
-				btrfs_dev_stat_reset(device, i);
+				btrfs_dev_stat_set(device, i, 0);
 		}
 
 		device->dev_stats_valid = 1;
@@ -7056,7 +7372,6 @@
 	}
 	mutex_unlock(&fs_devices->device_list_mutex);
 
-out:
 	btrfs_free_path(path);
 	return ret < 0 ? ret : 0;
 }
@@ -7129,9 +7444,9 @@
 /*
  * called from commit_transaction. Writes all changed device stats to disk.
  */
-int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
-			struct btrfs_fs_info *fs_info)
+int btrfs_run_dev_stats(struct btrfs_trans_handle *trans)
 {
+	struct btrfs_fs_info *fs_info = trans->fs_info;
 	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
 	struct btrfs_device *device;
 	int stats_cnt;
@@ -7214,7 +7529,8 @@
 	int i;
 
 	mutex_lock(&fs_devices->device_list_mutex);
-	dev = btrfs_find_device(fs_info, stats->devid, NULL, NULL);
+	dev = btrfs_find_device(fs_info->fs_devices, stats->devid, NULL, NULL,
+				true);
 	mutex_unlock(&fs_devices->device_list_mutex);
 
 	if (!dev) {
@@ -7229,7 +7545,7 @@
 				stats->values[i] =
 					btrfs_dev_stat_read_and_reset(dev, i);
 			else
-				btrfs_dev_stat_reset(dev, i);
+				btrfs_dev_stat_set(dev, i, 0);
 		}
 	} else {
 		for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
@@ -7272,51 +7588,34 @@
 }
 
 /*
- * Update the size of all devices, which is used for writing out the
- * super blocks.
+ * Update the size and bytes used for each device where it changed.  This is
+ * delayed since we would otherwise get errors while writing out the
+ * superblocks.
+ *
+ * Must be invoked during transaction commit.
  */
-void btrfs_update_commit_device_size(struct btrfs_fs_info *fs_info)
+void btrfs_commit_device_sizes(struct btrfs_transaction *trans)
 {
-	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
 	struct btrfs_device *curr, *next;
 
-	if (list_empty(&fs_devices->resized_devices))
+	ASSERT(trans->state == TRANS_STATE_COMMIT_DOING);
+
+	if (list_empty(&trans->dev_update_list))
 		return;
 
-	mutex_lock(&fs_devices->device_list_mutex);
-	mutex_lock(&fs_info->chunk_mutex);
-	list_for_each_entry_safe(curr, next, &fs_devices->resized_devices,
-				 resized_list) {
-		list_del_init(&curr->resized_list);
+	/*
+	 * We don't need the device_list_mutex here.  This list is owned by the
+	 * transaction and the transaction must complete before the device is
+	 * released.
+	 */
+	mutex_lock(&trans->fs_info->chunk_mutex);
+	list_for_each_entry_safe(curr, next, &trans->dev_update_list,
+				 post_commit_list) {
+		list_del_init(&curr->post_commit_list);
 		curr->commit_total_bytes = curr->disk_total_bytes;
+		curr->commit_bytes_used = curr->bytes_used;
 	}
-	mutex_unlock(&fs_info->chunk_mutex);
-	mutex_unlock(&fs_devices->device_list_mutex);
-}
-
-/* Must be invoked during the transaction commit */
-void btrfs_update_commit_device_bytes_used(struct btrfs_transaction *trans)
-{
-	struct btrfs_fs_info *fs_info = trans->fs_info;
-	struct extent_map *em;
-	struct map_lookup *map;
-	struct btrfs_device *dev;
-	int i;
-
-	if (list_empty(&trans->pending_chunks))
-		return;
-
-	/* In order to kick the device replace finish process */
-	mutex_lock(&fs_info->chunk_mutex);
-	list_for_each_entry(em, &trans->pending_chunks, list) {
-		map = em->map_lookup;
-
-		for (i = 0; i < map->num_stripes; i++) {
-			dev = map->stripes[i].dev;
-			dev->commit_bytes_used = dev->bytes_used;
-		}
-	}
-	mutex_unlock(&fs_info->chunk_mutex);
+	mutex_unlock(&trans->fs_info->chunk_mutex);
 }
 
 void btrfs_set_fs_info_ptr(struct btrfs_fs_info *fs_info)
@@ -7342,40 +7641,21 @@
  */
 int btrfs_bg_type_to_factor(u64 flags)
 {
-	if (flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
-		     BTRFS_BLOCK_GROUP_RAID10))
-		return 2;
-	return 1;
+	const int index = btrfs_bg_flags_to_raid_index(flags);
+
+	return btrfs_raid_array[index].ncopies;
 }
 
 
-static u64 calc_stripe_length(u64 type, u64 chunk_len, int num_stripes)
-{
-	int index = btrfs_bg_flags_to_raid_index(type);
-	int ncopies = btrfs_raid_array[index].ncopies;
-	int data_stripes;
-
-	switch (type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
-	case BTRFS_BLOCK_GROUP_RAID5:
-		data_stripes = num_stripes - 1;
-		break;
-	case BTRFS_BLOCK_GROUP_RAID6:
-		data_stripes = num_stripes - 2;
-		break;
-	default:
-		data_stripes = num_stripes / ncopies;
-		break;
-	}
-	return div_u64(chunk_len, data_stripes);
-}
 
 static int verify_one_dev_extent(struct btrfs_fs_info *fs_info,
 				 u64 chunk_offset, u64 devid,
 				 u64 physical_offset, u64 physical_len)
 {
-	struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree;
+	struct extent_map_tree *em_tree = &fs_info->mapping_tree;
 	struct extent_map *em;
 	struct map_lookup *map;
+	struct btrfs_device *dev;
 	u64 stripe_len;
 	bool found = false;
 	int ret = 0;
@@ -7425,6 +7705,35 @@
 			physical_offset, devid);
 		ret = -EUCLEAN;
 	}
+
+	/* Make sure no dev extent is beyond device bondary */
+	dev = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL, true);
+	if (!dev) {
+		btrfs_err(fs_info, "failed to find devid %llu", devid);
+		ret = -EUCLEAN;
+		goto out;
+	}
+
+	/* It's possible this device is a dummy for seed device */
+	if (dev->disk_total_bytes == 0) {
+		dev = btrfs_find_device(fs_info->fs_devices->seed, devid, NULL,
+					NULL, false);
+		if (!dev) {
+			btrfs_err(fs_info, "failed to find seed devid %llu",
+				  devid);
+			ret = -EUCLEAN;
+			goto out;
+		}
+	}
+
+	if (physical_offset + physical_len > dev->disk_total_bytes) {
+		btrfs_err(fs_info,
+"dev extent devid %llu physical offset %llu len %llu is beyond device boundary %llu",
+			  devid, physical_offset, physical_len,
+			  dev->disk_total_bytes);
+		ret = -EUCLEAN;
+		goto out;
+	}
 out:
 	free_extent_map(em);
 	return ret;
@@ -7432,13 +7741,13 @@
 
 static int verify_chunk_dev_extent_mapping(struct btrfs_fs_info *fs_info)
 {
-	struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree;
+	struct extent_map_tree *em_tree = &fs_info->mapping_tree;
 	struct extent_map *em;
 	struct rb_node *node;
 	int ret = 0;
 
 	read_lock(&em_tree->lock);
-	for (node = rb_first(&em_tree->map); node; node = rb_next(node)) {
+	for (node = rb_first_cached(&em_tree->map); node; node = rb_next(node)) {
 		em = rb_entry(node, struct extent_map, rb_node);
 		if (em->map_lookup->num_stripes !=
 		    em->map_lookup->verified_stripes) {
@@ -7467,6 +7776,8 @@
 	struct btrfs_path *path;
 	struct btrfs_root *root = fs_info->dev_root;
 	struct btrfs_key key;
+	u64 prev_devid = 0;
+	u64 prev_dev_ext_end = 0;
 	int ret = 0;
 
 	key.objectid = 1;
@@ -7511,10 +7822,22 @@
 		chunk_offset = btrfs_dev_extent_chunk_offset(leaf, dext);
 		physical_len = btrfs_dev_extent_length(leaf, dext);
 
+		/* Check if this dev extent overlaps with the previous one */
+		if (devid == prev_devid && physical_offset < prev_dev_ext_end) {
+			btrfs_err(fs_info,
+"dev extent devid %llu physical offset %llu overlap with previous dev extent end %llu",
+				  devid, physical_offset, prev_dev_ext_end);
+			ret = -EUCLEAN;
+			goto out;
+		}
+
 		ret = verify_one_dev_extent(fs_info, chunk_offset, devid,
 					    physical_offset, physical_len);
 		if (ret < 0)
 			goto out;
+		prev_devid = devid;
+		prev_dev_ext_end = physical_offset + physical_len;
+
 		ret = btrfs_next_item(root, path);
 		if (ret < 0)
 			goto out;
@@ -7530,3 +7853,27 @@
 	btrfs_free_path(path);
 	return ret;
 }
+
+/*
+ * Check whether the given block group or device is pinned by any inode being
+ * used as a swapfile.
+ */
+bool btrfs_pinned_by_swapfile(struct btrfs_fs_info *fs_info, void *ptr)
+{
+	struct btrfs_swapfile_pin *sp;
+	struct rb_node *node;
+
+	spin_lock(&fs_info->swapfile_pins_lock);
+	node = fs_info->swapfile_pins.rb_node;
+	while (node) {
+		sp = rb_entry(node, struct btrfs_swapfile_pin, node);
+		if (ptr < sp->ptr)
+			node = node->rb_left;
+		else if (ptr > sp->ptr)
+			node = node->rb_right;
+		else
+			break;
+	}
+	spin_unlock(&fs_info->swapfile_pins_lock);
+	return node != NULL;
+}
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 23e9285..a7da1f3 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -23,6 +23,21 @@
 	struct bio *tail;
 };
 
+struct btrfs_io_geometry {
+	/* remaining bytes before crossing a stripe */
+	u64 len;
+	/* offset of logical address in chunk */
+	u64 offset;
+	/* length of single IO stripe */
+	u64 stripe_len;
+	/* number of stripe where address falls */
+	u64 stripe_nr;
+	/* offset of address in stripe */
+	u64 stripe_offset;
+	/* offset of raid56 stripe into the chunk */
+	u64 raid56_stripe_offset;
+};
+
 /*
  * Use sequence counter to get consistent device stat data on
  * 32-bit processors.
@@ -43,8 +58,9 @@
 #define BTRFS_DEV_STATE_FLUSH_SENT	(4)
 
 struct btrfs_device {
-	struct list_head dev_list;
-	struct list_head dev_alloc_list;
+	struct list_head dev_list; /* device_list_mutex */
+	struct list_head dev_alloc_list; /* chunk mutex */
+	struct list_head post_commit_list; /* chunk mutex */
 	struct btrfs_fs_devices *fs_devices;
 	struct btrfs_fs_info *fs_info;
 
@@ -66,7 +82,6 @@
 
 	unsigned long dev_state;
 	blk_status_t last_flush_error;
-	int flush_bio_sent;
 
 #ifdef __BTRFS_NEED_DEVICE_DATA_ORDERED
 	seqcount_t data_seqcount;
@@ -102,18 +117,12 @@
 	 * size of the device on the current transaction
 	 *
 	 * This variant is update when committing the transaction,
-	 * and protected by device_list_mutex
+	 * and protected by chunk mutex
 	 */
 	u64 commit_total_bytes;
 
 	/* bytes used on the current transaction */
 	u64 commit_bytes_used;
-	/*
-	 * used to manage the device which is resized
-	 *
-	 * It is protected by chunk_lock.
-	 */
-	struct list_head resized_list;
 
 	/* for sending down flush barriers */
 	struct bio *flush_bio;
@@ -123,7 +132,6 @@
 	struct scrub_ctx *scrub_ctx;
 
 	struct btrfs_work work;
-	struct rcu_head rcu;
 
 	/* readahead state */
 	atomic_t reada_in_flight;
@@ -139,6 +147,8 @@
 	/* Counter to record the change of device stats */
 	atomic_t dev_stats_ccnt;
 	atomic_t dev_stat_values[BTRFS_DEV_STAT_VALUES_MAX];
+
+	struct extent_io_tree alloc_state;
 };
 
 /*
@@ -210,6 +220,8 @@
 
 struct btrfs_fs_devices {
 	u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
+	u8 metadata_uuid[BTRFS_FSID_SIZE];
+	bool fsid_change;
 	struct list_head fs_list;
 
 	u64 num_devices;
@@ -218,6 +230,10 @@
 	u64 missing_devices;
 	u64 total_rw_bytes;
 	u64 total_devices;
+
+	/* Highest generation number of seen devices */
+	u64 latest_generation;
+
 	struct block_device *latest_bdev;
 
 	/* all of the devices in the FS, protected by a mutex
@@ -227,10 +243,14 @@
 	 * this mutex lock.
 	 */
 	struct mutex device_list_mutex;
+
+	/* List of all devices, protected by device_list_mutex */
 	struct list_head devices;
 
-	struct list_head resized_devices;
-	/* devices not currently being allocated */
+	/*
+	 * Devices which can satisfy space allocation. Protected by
+	 * chunk_mutex
+	 */
 	struct list_head alloc_list;
 
 	struct btrfs_fs_devices *seed;
@@ -252,6 +272,15 @@
 
 #define BTRFS_BIO_INLINE_CSUM_SIZE	64
 
+#define BTRFS_MAX_DEVS(info) ((BTRFS_MAX_ITEM_SIZE(info)	\
+			- sizeof(struct btrfs_chunk))		\
+			/ sizeof(struct btrfs_stripe) + 1)
+
+#define BTRFS_MAX_DEVS_SYS_CHUNK ((BTRFS_SYSTEM_CHUNK_ARRAY_SIZE	\
+				- 2 * sizeof(struct btrfs_disk_key)	\
+				- 2 * sizeof(struct btrfs_chunk))	\
+				/ sizeof(struct btrfs_stripe) + 1)
+
 /*
  * we need the mirror number and stripe index to be passed around
  * the call chain while we are processing end_io (especially errors).
@@ -261,15 +290,12 @@
  * we allocate are actually btrfs_io_bios.  We'll cram as much of
  * struct btrfs_bio as we can into this over time.
  */
-typedef void (btrfs_io_bio_end_io_t) (struct btrfs_io_bio *bio, int err);
 struct btrfs_io_bio {
 	unsigned int mirror_num;
 	unsigned int stripe_index;
 	u64 logical;
 	u8 *csum;
 	u8 csum_inline[BTRFS_BIO_INLINE_CSUM_SIZE];
-	u8 *csum_allocated;
-	btrfs_io_bio_end_io_t *end_io;
 	struct bvec_iter iter;
 	/*
 	 * This member must come last, bio_alloc_bioset will allocate enough
@@ -283,15 +309,20 @@
 	return container_of(bio, struct btrfs_io_bio, bio);
 }
 
+static inline void btrfs_io_bio_free_csum(struct btrfs_io_bio *io_bio)
+{
+	if (io_bio->csum != io_bio->csum_inline) {
+		kfree(io_bio->csum);
+		io_bio->csum = NULL;
+	}
+}
+
 struct btrfs_bio_stripe {
 	struct btrfs_device *dev;
 	u64 physical;
 	u64 length; /* only used for discard mappings */
 };
 
-struct btrfs_bio;
-typedef void (btrfs_bio_end_io_t) (struct btrfs_bio *bio, int err);
-
 struct btrfs_bio {
 	refcount_t refs;
 	atomic_t stripes_pending;
@@ -324,14 +355,16 @@
 };
 
 struct btrfs_raid_attr {
-	int sub_stripes;	/* sub_stripes info for map */
-	int dev_stripes;	/* stripes per dev */
-	int devs_max;		/* max devs to use */
-	int devs_min;		/* min devs needed */
-	int tolerated_failures; /* max tolerated fail devs */
-	int devs_increment;	/* ndevs has to be a multiple of this */
-	int ncopies;		/* how many copies to data has */
-	int mindev_error;	/* error code if min devs requisite is unmet */
+	u8 sub_stripes;		/* sub_stripes info for map */
+	u8 dev_stripes;		/* stripes per dev */
+	u8 devs_max;		/* max devs to use */
+	u8 devs_min;		/* min devs needed */
+	u8 tolerated_failures;	/* max tolerated fail devs */
+	u8 devs_increment;	/* ndevs has to be a multiple of this */
+	u8 ncopies;		/* how many copies to data has */
+	u8 nparity;		/* number of stripes worth of bytes to store
+				 * parity information */
+	u8 mindev_error;	/* error code if min devs requisite is unmet */
 	const char raid_name[8]; /* name of the raid */
 	u64 bg_flag;		/* block group flag of the raid */
 };
@@ -380,6 +413,7 @@
 		return BTRFS_MAP_WRITE;
 	default:
 		WARN_ON_ONCE(1);
+		/* fall through */
 	case REQ_OP_READ:
 		return BTRFS_MAP_READ;
 	}
@@ -393,29 +427,28 @@
 int btrfs_map_sblock(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
 		     u64 logical, u64 *length,
 		     struct btrfs_bio **bbio_ret);
+int btrfs_get_io_geometry(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
+		u64 logical, u64 len, struct btrfs_io_geometry *io_geom);
 int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
 		     u64 physical, u64 **logical, int *naddrs, int *stripe_len);
 int btrfs_read_sys_array(struct btrfs_fs_info *fs_info);
 int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info);
 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, u64 type);
-void btrfs_mapping_init(struct btrfs_mapping_tree *tree);
-void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree);
+void btrfs_mapping_tree_free(struct extent_map_tree *tree);
 blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
 			   int mirror_num, int async_submit);
 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 		       fmode_t flags, void *holder);
 struct btrfs_device *btrfs_scan_one_device(const char *path,
 					   fmode_t flags, void *holder);
+int btrfs_forget_devices(const char *path);
 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
 void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices, int step);
 void btrfs_assign_next_active_device(struct btrfs_device *device,
 				     struct btrfs_device *this_dev);
-int btrfs_find_device_missing_or_by_path(struct btrfs_fs_info *fs_info,
-					 const char *device_path,
-					 struct btrfs_device **device);
-int btrfs_find_device_by_devspec(struct btrfs_fs_info *fs_info, u64 devid,
-					 const char *devpath,
-					 struct btrfs_device **device);
+struct btrfs_device *btrfs_find_device_by_devspec(struct btrfs_fs_info *fs_info,
+						  u64 devid,
+						  const char *devpath);
 struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
 					const u64 *devid,
 					const u8 *uuid);
@@ -426,13 +459,14 @@
 int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len);
 int btrfs_grow_device(struct btrfs_trans_handle *trans,
 		      struct btrfs_device *device, u64 new_size);
-struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
-				       u8 *uuid, u8 *fsid);
+struct btrfs_device *btrfs_find_device(struct btrfs_fs_devices *fs_devices,
+				       u64 devid, u8 *uuid, u8 *fsid, bool seed);
 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
 int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *path);
 int btrfs_balance(struct btrfs_fs_info *fs_info,
 		  struct btrfs_balance_control *bctl,
 		  struct btrfs_ioctl_balance_args *bargs);
+void btrfs_describe_block_groups(u64 flags, char *buf, u32 size_buf);
 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info);
 int btrfs_recover_balance(struct btrfs_fs_info *fs_info);
 int btrfs_pause_balance(struct btrfs_fs_info *fs_info);
@@ -440,22 +474,16 @@
 int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info);
 int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info);
 int btrfs_chunk_readonly(struct btrfs_fs_info *fs_info, u64 chunk_offset);
-int find_free_dev_extent_start(struct btrfs_transaction *transaction,
-			 struct btrfs_device *device, u64 num_bytes,
-			 u64 search_start, u64 *start, u64 *max_avail);
-int find_free_dev_extent(struct btrfs_trans_handle *trans,
-			 struct btrfs_device *device, u64 num_bytes,
+int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
 			 u64 *start, u64 *max_avail);
 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index);
 int btrfs_get_dev_stats(struct btrfs_fs_info *fs_info,
 			struct btrfs_ioctl_get_dev_stats *stats);
 void btrfs_init_devices_late(struct btrfs_fs_info *fs_info);
 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info);
-int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
-			struct btrfs_fs_info *fs_info);
+int btrfs_run_dev_stats(struct btrfs_trans_handle *trans);
 void btrfs_rm_dev_replace_remove_srcdev(struct btrfs_device *srcdev);
-void btrfs_rm_dev_replace_free_srcdev(struct btrfs_fs_info *fs_info,
-				      struct btrfs_device *srcdev);
+void btrfs_rm_dev_replace_free_srcdev(struct btrfs_device *srcdev);
 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_device *tgtdev);
 void btrfs_scratch_superblocks(struct block_device *bdev, const char *device_path);
 int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info,
@@ -465,6 +493,8 @@
 int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
 			     u64 chunk_offset, u64 chunk_size);
 int btrfs_remove_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset);
+struct extent_map *btrfs_get_chunk_map(struct btrfs_fs_info *fs_info,
+				       u64 logical, u64 length);
 
 static inline void btrfs_dev_stat_inc(struct btrfs_device *dev,
 				      int index)
@@ -517,12 +547,6 @@
 	atomic_inc(&dev->dev_stats_ccnt);
 }
 
-static inline void btrfs_dev_stat_reset(struct btrfs_device *dev,
-					int index)
-{
-	btrfs_dev_stat_set(dev, index, 0);
-}
-
 /*
  * Convert block group flags (BTRFS_BLOCK_GROUP_*) to btrfs_raid_types, which
  * can be used as index to access btrfs_raid_array[].
@@ -545,10 +569,7 @@
 	return BTRFS_RAID_SINGLE; /* BTRFS_BLOCK_GROUP_SINGLE */
 }
 
-const char *get_raid_name(enum btrfs_raid_types type);
-
-void btrfs_update_commit_device_size(struct btrfs_fs_info *fs_info);
-void btrfs_update_commit_device_bytes_used(struct btrfs_transaction *trans);
+void btrfs_commit_device_sizes(struct btrfs_transaction *trans);
 
 struct list_head *btrfs_get_fs_uuids(void);
 void btrfs_set_fs_info_ptr(struct btrfs_fs_info *fs_info);
@@ -557,6 +578,7 @@
 					struct btrfs_device *failing_dev);
 
 int btrfs_bg_type_to_factor(u64 flags);
+const char *btrfs_bg_type_to_raid_name(u64 flags);
 int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info);
 
 #endif
diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
index ea78c3d..95d9aeb 100644
--- a/fs/btrfs/xattr.c
+++ b/fs/btrfs/xattr.c
@@ -11,6 +11,7 @@
 #include <linux/security.h>
 #include <linux/posix_acl_xattr.h>
 #include <linux/iversion.h>
+#include <linux/sched/mm.h>
 #include "ctree.h"
 #include "btrfs_inode.h"
 #include "transaction.h"
@@ -75,9 +76,8 @@
 	return ret;
 }
 
-static int do_setxattr(struct btrfs_trans_handle *trans,
-		       struct inode *inode, const char *name,
-		       const void *value, size_t size, int flags)
+int btrfs_setxattr(struct btrfs_trans_handle *trans, struct inode *inode,
+		   const char *name, const void *value, size_t size, int flags)
 {
 	struct btrfs_dir_item *di = NULL;
 	struct btrfs_root *root = BTRFS_I(inode)->root;
@@ -86,6 +86,8 @@
 	size_t name_len = strlen(name);
 	int ret = 0;
 
+	ASSERT(trans);
+
 	if (name_len + size > BTRFS_MAX_XATTR_SIZE(root->fs_info))
 		return -ENOSPC;
 
@@ -173,7 +175,7 @@
 		char *ptr;
 
 		if (size > old_data_len) {
-			if (btrfs_leaf_free_space(fs_info, leaf) <
+			if (btrfs_leaf_free_space(leaf) <
 			    (size - old_data_len)) {
 				ret = -ENOSPC;
 				goto out;
@@ -183,17 +185,15 @@
 		if (old_data_len + name_len + sizeof(*di) == item_size) {
 			/* No other xattrs packed in the same leaf item. */
 			if (size > old_data_len)
-				btrfs_extend_item(fs_info, path,
-						  size - old_data_len);
+				btrfs_extend_item(path, size - old_data_len);
 			else if (size < old_data_len)
-				btrfs_truncate_item(fs_info, path,
-						    data_size, 1);
+				btrfs_truncate_item(path, data_size, 1);
 		} else {
 			/* There are other xattrs packed in the same item. */
 			ret = btrfs_delete_one_dir_name(trans, root, path, di);
 			if (ret)
 				goto out;
-			btrfs_extend_item(fs_info, path, data_size);
+			btrfs_extend_item(path, data_size);
 		}
 
 		item = btrfs_item_nr(slot);
@@ -213,36 +213,32 @@
 	}
 out:
 	btrfs_free_path(path);
+	if (!ret)
+		set_bit(BTRFS_INODE_COPY_EVERYTHING,
+			&BTRFS_I(inode)->runtime_flags);
 	return ret;
 }
 
 /*
  * @value: "" makes the attribute to empty, NULL removes it
  */
-int btrfs_setxattr(struct btrfs_trans_handle *trans,
-		     struct inode *inode, const char *name,
-		     const void *value, size_t size, int flags)
+int btrfs_setxattr_trans(struct inode *inode, const char *name,
+			 const void *value, size_t size, int flags)
 {
 	struct btrfs_root *root = BTRFS_I(inode)->root;
+	struct btrfs_trans_handle *trans;
 	int ret;
 
-	if (btrfs_root_readonly(root))
-		return -EROFS;
-
-	if (trans)
-		return do_setxattr(trans, inode, name, value, size, flags);
-
 	trans = btrfs_start_transaction(root, 2);
 	if (IS_ERR(trans))
 		return PTR_ERR(trans);
 
-	ret = do_setxattr(trans, inode, name, value, size, flags);
+	ret = btrfs_setxattr(trans, inode, name, value, size, flags);
 	if (ret)
 		goto out;
 
 	inode_inc_iversion(inode);
 	inode->i_ctime = current_time(inode);
-	set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
 	ret = btrfs_update_inode(trans, root, inode);
 	BUG_ON(ret);
 out:
@@ -369,7 +365,7 @@
 				   size_t size, int flags)
 {
 	name = xattr_full_name(handler, name);
-	return btrfs_setxattr(NULL, inode, name, buffer, size, flags);
+	return btrfs_setxattr_trans(inode, name, buffer, size, flags);
 }
 
 static int btrfs_xattr_handler_set_prop(const struct xattr_handler *handler,
@@ -377,8 +373,30 @@
 					const char *name, const void *value,
 					size_t size, int flags)
 {
+	int ret;
+	struct btrfs_trans_handle *trans;
+	struct btrfs_root *root = BTRFS_I(inode)->root;
+
 	name = xattr_full_name(handler, name);
-	return btrfs_set_prop(inode, name, value, size, flags);
+	ret = btrfs_validate_prop(name, value, size);
+	if (ret)
+		return ret;
+
+	trans = btrfs_start_transaction(root, 2);
+	if (IS_ERR(trans))
+		return PTR_ERR(trans);
+
+	ret = btrfs_set_prop(trans, inode, name, value, size, flags);
+	if (!ret) {
+		inode_inc_iversion(inode);
+		inode->i_ctime = current_time(inode);
+		ret = btrfs_update_inode(trans, root, inode);
+		BUG_ON(ret);
+	}
+
+	btrfs_end_transaction(trans);
+
+	return ret;
 }
 
 static const struct xattr_handler btrfs_security_xattr_handler = {
@@ -418,13 +436,19 @@
 };
 
 static int btrfs_initxattrs(struct inode *inode,
-			    const struct xattr *xattr_array, void *fs_info)
+			    const struct xattr *xattr_array, void *fs_private)
 {
+	struct btrfs_trans_handle *trans = fs_private;
 	const struct xattr *xattr;
-	struct btrfs_trans_handle *trans = fs_info;
+	unsigned int nofs_flag;
 	char *name;
 	int err = 0;
 
+	/*
+	 * We're holding a transaction handle, so use a NOFS memory allocation
+	 * context to avoid deadlock if reclaim happens.
+	 */
+	nofs_flag = memalloc_nofs_save();
 	for (xattr = xattr_array; xattr->name != NULL; xattr++) {
 		name = kmalloc(XATTR_SECURITY_PREFIX_LEN +
 			       strlen(xattr->name) + 1, GFP_KERNEL);
@@ -435,11 +459,12 @@
 		strcpy(name, XATTR_SECURITY_PREFIX);
 		strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name);
 		err = btrfs_setxattr(trans, inode, name, xattr->value,
-				xattr->value_len, 0);
+				     xattr->value_len, 0);
 		kfree(name);
 		if (err < 0)
 			break;
 	}
+	memalloc_nofs_restore(nofs_flag);
 	return err;
 }
 
diff --git a/fs/btrfs/xattr.h b/fs/btrfs/xattr.h
index 471fcac..1cd3fc0 100644
--- a/fs/btrfs/xattr.h
+++ b/fs/btrfs/xattr.h
@@ -12,9 +12,10 @@
 
 int btrfs_getxattr(struct inode *inode, const char *name,
 		void *buffer, size_t size);
-int btrfs_setxattr(struct btrfs_trans_handle *trans,
-			    struct inode *inode, const char *name,
-			    const void *value, size_t size, int flags);
+int btrfs_setxattr(struct btrfs_trans_handle *trans, struct inode *inode,
+		   const char *name, const void *value, size_t size, int flags);
+int btrfs_setxattr_trans(struct inode *inode, const char *name,
+			 const void *value, size_t size, int flags);
 ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size);
 
 int btrfs_xattr_security_init(struct btrfs_trans_handle *trans,
diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c
index 970ff3e..df1aace 100644
--- a/fs/btrfs/zlib.c
+++ b/fs/btrfs/zlib.c
@@ -27,6 +27,33 @@
 	int level;
 };
 
+static struct workspace_manager wsm;
+
+static void zlib_init_workspace_manager(void)
+{
+	btrfs_init_workspace_manager(&wsm, &btrfs_zlib_compress);
+}
+
+static void zlib_cleanup_workspace_manager(void)
+{
+	btrfs_cleanup_workspace_manager(&wsm);
+}
+
+static struct list_head *zlib_get_workspace(unsigned int level)
+{
+	struct list_head *ws = btrfs_get_workspace(&wsm, level);
+	struct workspace *workspace = list_entry(ws, struct workspace, list);
+
+	workspace->level = level;
+
+	return ws;
+}
+
+static void zlib_put_workspace(struct list_head *ws)
+{
+	btrfs_put_workspace(&wsm, ws);
+}
+
 static void zlib_free_workspace(struct list_head *ws)
 {
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
@@ -36,7 +63,7 @@
 	kfree(workspace);
 }
 
-static struct list_head *zlib_alloc_workspace(void)
+static struct list_head *zlib_alloc_workspace(unsigned int level)
 {
 	struct workspace *workspace;
 	int workspacesize;
@@ -48,6 +75,7 @@
 	workspacesize = max(zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL),
 			zlib_inflate_workspacesize());
 	workspace->strm.workspace = kvmalloc(workspacesize, GFP_KERNEL);
+	workspace->level = level;
 	workspace->buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
 	if (!workspace->strm.workspace || !workspace->buf)
 		goto fail;
@@ -390,22 +418,16 @@
 	return ret;
 }
 
-static void zlib_set_level(struct list_head *ws, unsigned int type)
-{
-	struct workspace *workspace = list_entry(ws, struct workspace, list);
-	unsigned level = (type & 0xF0) >> 4;
-
-	if (level > 9)
-		level = 9;
-
-	workspace->level = level > 0 ? level : 3;
-}
-
 const struct btrfs_compress_op btrfs_zlib_compress = {
+	.init_workspace_manager	= zlib_init_workspace_manager,
+	.cleanup_workspace_manager = zlib_cleanup_workspace_manager,
+	.get_workspace		= zlib_get_workspace,
+	.put_workspace		= zlib_put_workspace,
 	.alloc_workspace	= zlib_alloc_workspace,
 	.free_workspace		= zlib_free_workspace,
 	.compress_pages		= zlib_compress_pages,
 	.decompress_bio		= zlib_decompress_bio,
 	.decompress		= zlib_decompress,
-	.set_level              = zlib_set_level,
+	.max_level		= 9,
+	.default_level		= BTRFS_ZLIB_DEFAULT_LEVEL,
 };
diff --git a/fs/btrfs/zstd.c b/fs/btrfs/zstd.c
index af6ec59..764d47b 100644
--- a/fs/btrfs/zstd.c
+++ b/fs/btrfs/zstd.c
@@ -6,25 +6,32 @@
  */
 
 #include <linux/bio.h>
+#include <linux/bitmap.h>
 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
+#include <linux/sched/mm.h>
 #include <linux/pagemap.h>
 #include <linux/refcount.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/zstd.h>
+#include "misc.h"
 #include "compression.h"
+#include "ctree.h"
 
 #define ZSTD_BTRFS_MAX_WINDOWLOG 17
 #define ZSTD_BTRFS_MAX_INPUT (1 << ZSTD_BTRFS_MAX_WINDOWLOG)
 #define ZSTD_BTRFS_DEFAULT_LEVEL 3
+#define ZSTD_BTRFS_MAX_LEVEL 15
+/* 307s to avoid pathologically clashing with transaction commit */
+#define ZSTD_BTRFS_RECLAIM_JIFFIES (307 * HZ)
 
-static ZSTD_parameters zstd_get_btrfs_parameters(size_t src_len)
+static ZSTD_parameters zstd_get_btrfs_parameters(unsigned int level,
+						 size_t src_len)
 {
-	ZSTD_parameters params = ZSTD_getParams(ZSTD_BTRFS_DEFAULT_LEVEL,
-						src_len, 0);
+	ZSTD_parameters params = ZSTD_getParams(level, src_len, 0);
 
 	if (params.cParams.windowLog > ZSTD_BTRFS_MAX_WINDOWLOG)
 		params.cParams.windowLog = ZSTD_BTRFS_MAX_WINDOWLOG;
@@ -36,11 +43,295 @@
 	void *mem;
 	size_t size;
 	char *buf;
+	unsigned int level;
+	unsigned int req_level;
+	unsigned long last_used; /* jiffies */
 	struct list_head list;
+	struct list_head lru_list;
 	ZSTD_inBuffer in_buf;
 	ZSTD_outBuffer out_buf;
 };
 
+/*
+ * Zstd Workspace Management
+ *
+ * Zstd workspaces have different memory requirements depending on the level.
+ * The zstd workspaces are managed by having individual lists for each level
+ * and a global lru.  Forward progress is maintained by protecting a max level
+ * workspace.
+ *
+ * Getting a workspace is done by using the bitmap to identify the levels that
+ * have available workspaces and scans up.  This lets us recycle higher level
+ * workspaces because of the monotonic memory guarantee.  A workspace's
+ * last_used is only updated if it is being used by the corresponding memory
+ * level.  Putting a workspace involves adding it back to the appropriate places
+ * and adding it back to the lru if necessary.
+ *
+ * A timer is used to reclaim workspaces if they have not been used for
+ * ZSTD_BTRFS_RECLAIM_JIFFIES.  This helps keep only active workspaces around.
+ * The upper bound is provided by the workqueue limit which is 2 (percpu limit).
+ */
+
+struct zstd_workspace_manager {
+	const struct btrfs_compress_op *ops;
+	spinlock_t lock;
+	struct list_head lru_list;
+	struct list_head idle_ws[ZSTD_BTRFS_MAX_LEVEL];
+	unsigned long active_map;
+	wait_queue_head_t wait;
+	struct timer_list timer;
+};
+
+static struct zstd_workspace_manager wsm;
+
+static size_t zstd_ws_mem_sizes[ZSTD_BTRFS_MAX_LEVEL];
+
+static inline struct workspace *list_to_workspace(struct list_head *list)
+{
+	return container_of(list, struct workspace, list);
+}
+
+static void zstd_free_workspace(struct list_head *ws);
+static struct list_head *zstd_alloc_workspace(unsigned int level);
+
+/*
+ * zstd_reclaim_timer_fn - reclaim timer
+ * @t: timer
+ *
+ * This scans the lru_list and attempts to reclaim any workspace that hasn't
+ * been used for ZSTD_BTRFS_RECLAIM_JIFFIES.
+ */
+static void zstd_reclaim_timer_fn(struct timer_list *timer)
+{
+	unsigned long reclaim_threshold = jiffies - ZSTD_BTRFS_RECLAIM_JIFFIES;
+	struct list_head *pos, *next;
+
+	spin_lock_bh(&wsm.lock);
+
+	if (list_empty(&wsm.lru_list)) {
+		spin_unlock_bh(&wsm.lock);
+		return;
+	}
+
+	list_for_each_prev_safe(pos, next, &wsm.lru_list) {
+		struct workspace *victim = container_of(pos, struct workspace,
+							lru_list);
+		unsigned int level;
+
+		if (time_after(victim->last_used, reclaim_threshold))
+			break;
+
+		/* workspace is in use */
+		if (victim->req_level)
+			continue;
+
+		level = victim->level;
+		list_del(&victim->lru_list);
+		list_del(&victim->list);
+		zstd_free_workspace(&victim->list);
+
+		if (list_empty(&wsm.idle_ws[level - 1]))
+			clear_bit(level - 1, &wsm.active_map);
+
+	}
+
+	if (!list_empty(&wsm.lru_list))
+		mod_timer(&wsm.timer, jiffies + ZSTD_BTRFS_RECLAIM_JIFFIES);
+
+	spin_unlock_bh(&wsm.lock);
+}
+
+/*
+ * zstd_calc_ws_mem_sizes - calculate monotonic memory bounds
+ *
+ * It is possible based on the level configurations that a higher level
+ * workspace uses less memory than a lower level workspace.  In order to reuse
+ * workspaces, this must be made a monotonic relationship.  This precomputes
+ * the required memory for each level and enforces the monotonicity between
+ * level and memory required.
+ */
+static void zstd_calc_ws_mem_sizes(void)
+{
+	size_t max_size = 0;
+	unsigned int level;
+
+	for (level = 1; level <= ZSTD_BTRFS_MAX_LEVEL; level++) {
+		ZSTD_parameters params =
+			zstd_get_btrfs_parameters(level, ZSTD_BTRFS_MAX_INPUT);
+		size_t level_size =
+			max_t(size_t,
+			      ZSTD_CStreamWorkspaceBound(params.cParams),
+			      ZSTD_DStreamWorkspaceBound(ZSTD_BTRFS_MAX_INPUT));
+
+		max_size = max_t(size_t, max_size, level_size);
+		zstd_ws_mem_sizes[level - 1] = max_size;
+	}
+}
+
+static void zstd_init_workspace_manager(void)
+{
+	struct list_head *ws;
+	int i;
+
+	zstd_calc_ws_mem_sizes();
+
+	wsm.ops = &btrfs_zstd_compress;
+	spin_lock_init(&wsm.lock);
+	init_waitqueue_head(&wsm.wait);
+	timer_setup(&wsm.timer, zstd_reclaim_timer_fn, 0);
+
+	INIT_LIST_HEAD(&wsm.lru_list);
+	for (i = 0; i < ZSTD_BTRFS_MAX_LEVEL; i++)
+		INIT_LIST_HEAD(&wsm.idle_ws[i]);
+
+	ws = zstd_alloc_workspace(ZSTD_BTRFS_MAX_LEVEL);
+	if (IS_ERR(ws)) {
+		pr_warn(
+		"BTRFS: cannot preallocate zstd compression workspace\n");
+	} else {
+		set_bit(ZSTD_BTRFS_MAX_LEVEL - 1, &wsm.active_map);
+		list_add(ws, &wsm.idle_ws[ZSTD_BTRFS_MAX_LEVEL - 1]);
+	}
+}
+
+static void zstd_cleanup_workspace_manager(void)
+{
+	struct workspace *workspace;
+	int i;
+
+	spin_lock_bh(&wsm.lock);
+	for (i = 0; i < ZSTD_BTRFS_MAX_LEVEL; i++) {
+		while (!list_empty(&wsm.idle_ws[i])) {
+			workspace = container_of(wsm.idle_ws[i].next,
+						 struct workspace, list);
+			list_del(&workspace->list);
+			list_del(&workspace->lru_list);
+			zstd_free_workspace(&workspace->list);
+		}
+	}
+	spin_unlock_bh(&wsm.lock);
+
+	del_timer_sync(&wsm.timer);
+}
+
+/*
+ * zstd_find_workspace - find workspace
+ * @level: compression level
+ *
+ * This iterates over the set bits in the active_map beginning at the requested
+ * compression level.  This lets us utilize already allocated workspaces before
+ * allocating a new one.  If the workspace is of a larger size, it is used, but
+ * the place in the lru_list and last_used times are not updated.  This is to
+ * offer the opportunity to reclaim the workspace in favor of allocating an
+ * appropriately sized one in the future.
+ */
+static struct list_head *zstd_find_workspace(unsigned int level)
+{
+	struct list_head *ws;
+	struct workspace *workspace;
+	int i = level - 1;
+
+	spin_lock_bh(&wsm.lock);
+	for_each_set_bit_from(i, &wsm.active_map, ZSTD_BTRFS_MAX_LEVEL) {
+		if (!list_empty(&wsm.idle_ws[i])) {
+			ws = wsm.idle_ws[i].next;
+			workspace = list_to_workspace(ws);
+			list_del_init(ws);
+			/* keep its place if it's a lower level using this */
+			workspace->req_level = level;
+			if (level == workspace->level)
+				list_del(&workspace->lru_list);
+			if (list_empty(&wsm.idle_ws[i]))
+				clear_bit(i, &wsm.active_map);
+			spin_unlock_bh(&wsm.lock);
+			return ws;
+		}
+	}
+	spin_unlock_bh(&wsm.lock);
+
+	return NULL;
+}
+
+/*
+ * zstd_get_workspace - zstd's get_workspace
+ * @level: compression level
+ *
+ * If @level is 0, then any compression level can be used.  Therefore, we begin
+ * scanning from 1.  We first scan through possible workspaces and then after
+ * attempt to allocate a new workspace.  If we fail to allocate one due to
+ * memory pressure, go to sleep waiting for the max level workspace to free up.
+ */
+static struct list_head *zstd_get_workspace(unsigned int level)
+{
+	struct list_head *ws;
+	unsigned int nofs_flag;
+
+	/* level == 0 means we can use any workspace */
+	if (!level)
+		level = 1;
+
+again:
+	ws = zstd_find_workspace(level);
+	if (ws)
+		return ws;
+
+	nofs_flag = memalloc_nofs_save();
+	ws = zstd_alloc_workspace(level);
+	memalloc_nofs_restore(nofs_flag);
+
+	if (IS_ERR(ws)) {
+		DEFINE_WAIT(wait);
+
+		prepare_to_wait(&wsm.wait, &wait, TASK_UNINTERRUPTIBLE);
+		schedule();
+		finish_wait(&wsm.wait, &wait);
+
+		goto again;
+	}
+
+	return ws;
+}
+
+/*
+ * zstd_put_workspace - zstd put_workspace
+ * @ws: list_head for the workspace
+ *
+ * When putting back a workspace, we only need to update the LRU if we are of
+ * the requested compression level.  Here is where we continue to protect the
+ * max level workspace or update last_used accordingly.  If the reclaim timer
+ * isn't set, it is also set here.  Only the max level workspace tries and wakes
+ * up waiting workspaces.
+ */
+static void zstd_put_workspace(struct list_head *ws)
+{
+	struct workspace *workspace = list_to_workspace(ws);
+
+	spin_lock_bh(&wsm.lock);
+
+	/* A node is only taken off the lru if we are the corresponding level */
+	if (workspace->req_level == workspace->level) {
+		/* Hide a max level workspace from reclaim */
+		if (list_empty(&wsm.idle_ws[ZSTD_BTRFS_MAX_LEVEL - 1])) {
+			INIT_LIST_HEAD(&workspace->lru_list);
+		} else {
+			workspace->last_used = jiffies;
+			list_add(&workspace->lru_list, &wsm.lru_list);
+			if (!timer_pending(&wsm.timer))
+				mod_timer(&wsm.timer,
+					  jiffies + ZSTD_BTRFS_RECLAIM_JIFFIES);
+		}
+	}
+
+	set_bit(workspace->level - 1, &wsm.active_map);
+	list_add(&workspace->list, &wsm.idle_ws[workspace->level - 1]);
+	workspace->req_level = 0;
+
+	spin_unlock_bh(&wsm.lock);
+
+	if (workspace->level == ZSTD_BTRFS_MAX_LEVEL)
+		cond_wake_up(&wsm.wait);
+}
+
 static void zstd_free_workspace(struct list_head *ws)
 {
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
@@ -50,25 +341,25 @@
 	kfree(workspace);
 }
 
-static struct list_head *zstd_alloc_workspace(void)
+static struct list_head *zstd_alloc_workspace(unsigned int level)
 {
-	ZSTD_parameters params =
-			zstd_get_btrfs_parameters(ZSTD_BTRFS_MAX_INPUT);
 	struct workspace *workspace;
 
 	workspace = kzalloc(sizeof(*workspace), GFP_KERNEL);
 	if (!workspace)
 		return ERR_PTR(-ENOMEM);
 
-	workspace->size = max_t(size_t,
-			ZSTD_CStreamWorkspaceBound(params.cParams),
-			ZSTD_DStreamWorkspaceBound(ZSTD_BTRFS_MAX_INPUT));
+	workspace->size = zstd_ws_mem_sizes[level - 1];
+	workspace->level = level;
+	workspace->req_level = level;
+	workspace->last_used = jiffies;
 	workspace->mem = kvmalloc(workspace->size, GFP_KERNEL);
 	workspace->buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
 	if (!workspace->mem || !workspace->buf)
 		goto fail;
 
 	INIT_LIST_HEAD(&workspace->list);
+	INIT_LIST_HEAD(&workspace->lru_list);
 
 	return &workspace->list;
 fail:
@@ -95,7 +386,8 @@
 	unsigned long len = *total_out;
 	const unsigned long nr_dest_pages = *out_pages;
 	unsigned long max_out = nr_dest_pages * PAGE_SIZE;
-	ZSTD_parameters params = zstd_get_btrfs_parameters(len);
+	ZSTD_parameters params = zstd_get_btrfs_parameters(workspace->req_level,
+							   len);
 
 	*out_pages = 0;
 	*total_out = 0;
@@ -419,15 +711,16 @@
 	return ret;
 }
 
-static void zstd_set_level(struct list_head *ws, unsigned int type)
-{
-}
-
 const struct btrfs_compress_op btrfs_zstd_compress = {
+	.init_workspace_manager = zstd_init_workspace_manager,
+	.cleanup_workspace_manager = zstd_cleanup_workspace_manager,
+	.get_workspace = zstd_get_workspace,
+	.put_workspace = zstd_put_workspace,
 	.alloc_workspace = zstd_alloc_workspace,
 	.free_workspace = zstd_free_workspace,
 	.compress_pages = zstd_compress_pages,
 	.decompress_bio = zstd_decompress_bio,
 	.decompress = zstd_decompress,
-	.set_level = zstd_set_level,
+	.max_level	= ZSTD_BTRFS_MAX_LEVEL,
+	.default_level	= ZSTD_BTRFS_DEFAULT_LEVEL,
 };