v4.19.13 snapshot.
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
new file mode 100644
index 0000000..16ecb76
--- /dev/null
+++ b/fs/btrfs/tree-log.c
@@ -0,0 +1,6156 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2008 Oracle. All rights reserved.
+ */
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/blkdev.h>
+#include <linux/list_sort.h>
+#include <linux/iversion.h>
+#include "ctree.h"
+#include "tree-log.h"
+#include "disk-io.h"
+#include "locking.h"
+#include "print-tree.h"
+#include "backref.h"
+#include "compression.h"
+#include "qgroup.h"
+#include "inode-map.h"
+
+/* magic values for the inode_only field in btrfs_log_inode:
+ *
+ * LOG_INODE_ALL means to log everything
+ * 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
+
+/*
+ * directory trouble cases
+ *
+ * 1) on rename or unlink, if the inode being unlinked isn't in the fsync
+ * log, we must force a full commit before doing an fsync of the directory
+ * where the unlink was done.
+ * ---> record transid of last unlink/rename per directory
+ *
+ * mkdir foo/some_dir
+ * normal commit
+ * rename foo/some_dir foo2/some_dir
+ * mkdir foo/some_dir
+ * fsync foo/some_dir/some_file
+ *
+ * The fsync above will unlink the original some_dir without recording
+ * it in its new location (foo2). After a crash, some_dir will be gone
+ * unless the fsync of some_file forces a full commit
+ *
+ * 2) we must log any new names for any file or dir that is in the fsync
+ * log. ---> check inode while renaming/linking.
+ *
+ * 2a) we must log any new names for any file or dir during rename
+ * when the directory they are being removed from was logged.
+ * ---> check inode and old parent dir during rename
+ *
+ * 2a is actually the more important variant. With the extra logging
+ * a crash might unlink the old name without recreating the new one
+ *
+ * 3) after a crash, we must go through any directories with a link count
+ * of zero and redo the rm -rf
+ *
+ * mkdir f1/foo
+ * normal commit
+ * rm -rf f1/foo
+ * fsync(f1)
+ *
+ * The directory f1 was fully removed from the FS, but fsync was never
+ * called on f1, only its parent dir. After a crash the rm -rf must
+ * be replayed. This must be able to recurse down the entire
+ * directory tree. The inode link count fixup code takes care of the
+ * ugly details.
+ */
+
+/*
+ * stages for the tree walking. The first
+ * stage (0) is to only pin down the blocks we find
+ * the second stage (1) is to make sure that all the inodes
+ * we find in the log are created in the subvolume.
+ *
+ * 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
+
+static int btrfs_log_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct btrfs_inode *inode,
+ int inode_only,
+ const loff_t start,
+ const loff_t end,
+ struct btrfs_log_ctx *ctx);
+static int link_to_fixup_dir(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, u64 objectid);
+static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_root *log,
+ struct btrfs_path *path,
+ u64 dirid, int del_all);
+
+/*
+ * tree logging is a special write ahead log used to make sure that
+ * fsyncs and O_SYNCs can happen without doing full tree commits.
+ *
+ * Full tree commits are expensive because they require commonly
+ * modified blocks to be recowed, creating many dirty pages in the
+ * extent tree an 4x-6x higher write load than ext3.
+ *
+ * Instead of doing a tree commit on every fsync, we use the
+ * key ranges and transaction ids to find items for a given file or directory
+ * that have changed in this transaction. Those items are copied into
+ * a special tree (one per subvolume root), that tree is written to disk
+ * and then the fsync is considered complete.
+ *
+ * After a crash, items are copied out of the log-tree back into the
+ * subvolume tree. Any file data extents found are recorded in the extent
+ * allocation tree, and the log-tree freed.
+ *
+ * The log tree is read three times, once to pin down all the extents it is
+ * using in ram and once, once to create all the inodes logged in the tree
+ * and once to do all the other items.
+ */
+
+/*
+ * start a sub transaction and setup the log tree
+ * this increments the log tree writer count to make the people
+ * syncing the tree wait for us to finish
+ */
+static int start_log_trans(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_log_ctx *ctx)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ int ret = 0;
+
+ mutex_lock(&root->log_mutex);
+
+ if (root->log_root) {
+ if (btrfs_need_log_full_commit(fs_info, trans)) {
+ ret = -EAGAIN;
+ goto out;
+ }
+
+ if (!root->log_start_pid) {
+ clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
+ root->log_start_pid = current->pid;
+ } else if (root->log_start_pid != current->pid) {
+ set_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
+ }
+ } else {
+ mutex_lock(&fs_info->tree_log_mutex);
+ if (!fs_info->log_root_tree)
+ ret = btrfs_init_log_root_tree(trans, fs_info);
+ mutex_unlock(&fs_info->tree_log_mutex);
+ if (ret)
+ goto out;
+
+ ret = btrfs_add_log_tree(trans, root);
+ if (ret)
+ goto out;
+
+ clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
+ root->log_start_pid = current->pid;
+ }
+
+ atomic_inc(&root->log_batch);
+ atomic_inc(&root->log_writers);
+ if (ctx) {
+ int index = root->log_transid % 2;
+ list_add_tail(&ctx->list, &root->log_ctxs[index]);
+ ctx->log_transid = root->log_transid;
+ }
+
+out:
+ mutex_unlock(&root->log_mutex);
+ return ret;
+}
+
+/*
+ * returns 0 if there was a log transaction running and we were able
+ * to join, or returns -ENOENT if there were not transactions
+ * in progress
+ */
+static int join_running_log_trans(struct btrfs_root *root)
+{
+ int ret = -ENOENT;
+
+ smp_mb();
+ if (!root->log_root)
+ return -ENOENT;
+
+ mutex_lock(&root->log_mutex);
+ if (root->log_root) {
+ ret = 0;
+ atomic_inc(&root->log_writers);
+ }
+ mutex_unlock(&root->log_mutex);
+ return ret;
+}
+
+/*
+ * This either makes the current running log transaction wait
+ * 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)
+{
+ int ret = -ENOENT;
+
+ mutex_lock(&root->log_mutex);
+ atomic_inc(&root->log_writers);
+ mutex_unlock(&root->log_mutex);
+ return ret;
+}
+
+/*
+ * indicate we're done making changes to the log tree
+ * and wake up anyone waiting to do a sync
+ */
+void btrfs_end_log_trans(struct btrfs_root *root)
+{
+ if (atomic_dec_and_test(&root->log_writers)) {
+ /* atomic_dec_and_test implies a barrier */
+ cond_wake_up_nomb(&root->log_writer_wait);
+ }
+}
+
+
+/*
+ * the walk control struct is used to pass state down the chain when
+ * processing the log tree. The stage field tells us which part
+ * of the log tree processing we are currently doing. The others
+ * are state fields used for that specific part
+ */
+struct walk_control {
+ /* should we free the extent on disk when done? This is used
+ * at transaction commit time while freeing a log tree
+ */
+ int free;
+
+ /* should we write out the extent buffer? This is used
+ * while flushing the log tree to disk during a sync
+ */
+ int write;
+
+ /* should we wait for the extent buffer io to finish? Also used
+ * while flushing the log tree to disk for a sync
+ */
+ int wait;
+
+ /* pin only walk, we record which extents on disk belong to the
+ * log trees
+ */
+ int pin;
+
+ /* what stage of the replay code we're currently in */
+ int stage;
+
+ /*
+ * Ignore any items from the inode currently being processed. Needs
+ * to be set every time we find a BTRFS_INODE_ITEM_KEY and we are in
+ * the LOG_WALK_REPLAY_INODES stage.
+ */
+ bool ignore_cur_inode;
+
+ /* the root we are currently replaying */
+ struct btrfs_root *replay_dest;
+
+ /* the trans handle for the current replay */
+ struct btrfs_trans_handle *trans;
+
+ /* the function that gets used to process blocks we find in the
+ * tree. Note the extent_buffer might not be up to date when it is
+ * passed in, and it must be checked or read if you need the data
+ * inside it
+ */
+ int (*process_func)(struct btrfs_root *log, struct extent_buffer *eb,
+ struct walk_control *wc, u64 gen, int level);
+};
+
+/*
+ * process_func used to pin down extents, write them or wait on them
+ */
+static int process_one_buffer(struct btrfs_root *log,
+ struct extent_buffer *eb,
+ struct walk_control *wc, u64 gen, int level)
+{
+ struct btrfs_fs_info *fs_info = log->fs_info;
+ int ret = 0;
+
+ /*
+ * If this fs is mixed then we need to be able to process the leaves to
+ * pin down any logged extents, so we have to read the block.
+ */
+ if (btrfs_fs_incompat(fs_info, MIXED_GROUPS)) {
+ ret = btrfs_read_buffer(eb, gen, level, NULL);
+ if (ret)
+ return ret;
+ }
+
+ if (wc->pin)
+ ret = btrfs_pin_extent_for_log_replay(fs_info, eb->start,
+ eb->len);
+
+ if (!ret && btrfs_buffer_uptodate(eb, gen, 0)) {
+ if (wc->pin && btrfs_header_level(eb) == 0)
+ ret = btrfs_exclude_logged_extents(fs_info, eb);
+ if (wc->write)
+ btrfs_write_tree_block(eb);
+ if (wc->wait)
+ btrfs_wait_tree_block_writeback(eb);
+ }
+ return ret;
+}
+
+/*
+ * Item overwrite used by replay and tree logging. eb, slot and key all refer
+ * to the src data we are copying out.
+ *
+ * root is the tree we are copying into, and path is a scratch
+ * path for use in this function (it should be released on entry and
+ * will be released on exit).
+ *
+ * If the key is already in the destination tree the existing item is
+ * overwritten. If the existing item isn't big enough, it is extended.
+ * If it is too large, it is truncated.
+ *
+ * If the key isn't in the destination yet, a new item is inserted.
+ */
+static noinline int overwrite_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ 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;
+ int save_old_i_size = 0;
+ unsigned long src_ptr;
+ unsigned long dst_ptr;
+ int overwrite_root = 0;
+ bool inode_item = key->type == BTRFS_INODE_ITEM_KEY;
+
+ if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
+ overwrite_root = 1;
+
+ item_size = btrfs_item_size_nr(eb, slot);
+ src_ptr = btrfs_item_ptr_offset(eb, slot);
+
+ /* look for the key in the destination tree */
+ ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
+ if (ret < 0)
+ return ret;
+
+ if (ret == 0) {
+ char *src_copy;
+ char *dst_copy;
+ u32 dst_size = btrfs_item_size_nr(path->nodes[0],
+ path->slots[0]);
+ if (dst_size != item_size)
+ goto insert;
+
+ if (item_size == 0) {
+ btrfs_release_path(path);
+ return 0;
+ }
+ dst_copy = kmalloc(item_size, GFP_NOFS);
+ src_copy = kmalloc(item_size, GFP_NOFS);
+ if (!dst_copy || !src_copy) {
+ btrfs_release_path(path);
+ kfree(dst_copy);
+ kfree(src_copy);
+ return -ENOMEM;
+ }
+
+ read_extent_buffer(eb, src_copy, src_ptr, item_size);
+
+ dst_ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
+ read_extent_buffer(path->nodes[0], dst_copy, dst_ptr,
+ item_size);
+ ret = memcmp(dst_copy, src_copy, item_size);
+
+ kfree(dst_copy);
+ kfree(src_copy);
+ /*
+ * they have the same contents, just return, this saves
+ * us from cowing blocks in the destination tree and doing
+ * extra writes that may not have been done by a previous
+ * sync
+ */
+ if (ret == 0) {
+ btrfs_release_path(path);
+ return 0;
+ }
+
+ /*
+ * We need to load the old nbytes into the inode so when we
+ * replay the extents we've logged we get the right nbytes.
+ */
+ if (inode_item) {
+ struct btrfs_inode_item *item;
+ u64 nbytes;
+ u32 mode;
+
+ item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_inode_item);
+ nbytes = btrfs_inode_nbytes(path->nodes[0], item);
+ item = btrfs_item_ptr(eb, slot,
+ struct btrfs_inode_item);
+ btrfs_set_inode_nbytes(eb, item, nbytes);
+
+ /*
+ * If this is a directory we need to reset the i_size to
+ * 0 so that we can set it up properly when replaying
+ * the rest of the items in this log.
+ */
+ mode = btrfs_inode_mode(eb, item);
+ if (S_ISDIR(mode))
+ btrfs_set_inode_size(eb, item, 0);
+ }
+ } else if (inode_item) {
+ struct btrfs_inode_item *item;
+ u32 mode;
+
+ /*
+ * New inode, set nbytes to 0 so that the nbytes comes out
+ * properly when we replay the extents.
+ */
+ item = btrfs_item_ptr(eb, slot, struct btrfs_inode_item);
+ btrfs_set_inode_nbytes(eb, item, 0);
+
+ /*
+ * If this is a directory we need to reset the i_size to 0 so
+ * that we can set it up properly when replaying the rest of
+ * the items in this log.
+ */
+ mode = btrfs_inode_mode(eb, item);
+ if (S_ISDIR(mode))
+ btrfs_set_inode_size(eb, item, 0);
+ }
+insert:
+ btrfs_release_path(path);
+ /* try to insert the key into the destination tree */
+ path->skip_release_on_error = 1;
+ ret = btrfs_insert_empty_item(trans, root, path,
+ key, item_size);
+ path->skip_release_on_error = 0;
+
+ /* make sure any existing item is the correct size */
+ if (ret == -EEXIST || ret == -EOVERFLOW) {
+ u32 found_size;
+ 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);
+ else if (found_size < item_size)
+ btrfs_extend_item(fs_info, path,
+ item_size - found_size);
+ } else if (ret) {
+ return ret;
+ }
+ dst_ptr = btrfs_item_ptr_offset(path->nodes[0],
+ path->slots[0]);
+
+ /* don't overwrite an existing inode if the generation number
+ * was logged as zero. This is done when the tree logging code
+ * is just logging an inode to make sure it exists after recovery.
+ *
+ * Also, don't overwrite i_size on directories during replay.
+ * log replay inserts and removes directory items based on the
+ * state of the tree found in the subvolume, and i_size is modified
+ * as it goes
+ */
+ if (key->type == BTRFS_INODE_ITEM_KEY && ret == -EEXIST) {
+ struct btrfs_inode_item *src_item;
+ struct btrfs_inode_item *dst_item;
+
+ src_item = (struct btrfs_inode_item *)src_ptr;
+ dst_item = (struct btrfs_inode_item *)dst_ptr;
+
+ if (btrfs_inode_generation(eb, src_item) == 0) {
+ struct extent_buffer *dst_eb = path->nodes[0];
+ const u64 ino_size = btrfs_inode_size(eb, src_item);
+
+ /*
+ * For regular files an ino_size == 0 is used only when
+ * logging that an inode exists, as part of a directory
+ * fsync, and the inode wasn't fsynced before. In this
+ * case don't set the size of the inode in the fs/subvol
+ * tree, otherwise we would be throwing valid data away.
+ */
+ if (S_ISREG(btrfs_inode_mode(eb, src_item)) &&
+ S_ISREG(btrfs_inode_mode(dst_eb, dst_item)) &&
+ ino_size != 0) {
+ struct btrfs_map_token token;
+
+ btrfs_init_map_token(&token);
+ btrfs_set_token_inode_size(dst_eb, dst_item,
+ ino_size, &token);
+ }
+ goto no_copy;
+ }
+
+ if (overwrite_root &&
+ S_ISDIR(btrfs_inode_mode(eb, src_item)) &&
+ S_ISDIR(btrfs_inode_mode(path->nodes[0], dst_item))) {
+ save_old_i_size = 1;
+ saved_i_size = btrfs_inode_size(path->nodes[0],
+ dst_item);
+ }
+ }
+
+ copy_extent_buffer(path->nodes[0], eb, dst_ptr,
+ src_ptr, item_size);
+
+ if (save_old_i_size) {
+ struct btrfs_inode_item *dst_item;
+ dst_item = (struct btrfs_inode_item *)dst_ptr;
+ btrfs_set_inode_size(path->nodes[0], dst_item, saved_i_size);
+ }
+
+ /* make sure the generation is filled in */
+ if (key->type == BTRFS_INODE_ITEM_KEY) {
+ struct btrfs_inode_item *dst_item;
+ dst_item = (struct btrfs_inode_item *)dst_ptr;
+ if (btrfs_inode_generation(path->nodes[0], dst_item) == 0) {
+ btrfs_set_inode_generation(path->nodes[0], dst_item,
+ trans->transid);
+ }
+ }
+no_copy:
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+ btrfs_release_path(path);
+ return 0;
+}
+
+/*
+ * simple helper to read an inode off the disk from a given root
+ * This can only be called for subvolume roots and not for the log
+ */
+static noinline struct inode *read_one_inode(struct btrfs_root *root,
+ u64 objectid)
+{
+ struct btrfs_key key;
+ struct inode *inode;
+
+ key.objectid = objectid;
+ key.type = BTRFS_INODE_ITEM_KEY;
+ key.offset = 0;
+ inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
+ if (IS_ERR(inode))
+ inode = NULL;
+ return inode;
+}
+
+/* replays a single extent in 'eb' at 'slot' with 'key' into the
+ * subvolume 'root'. path is released on entry and should be released
+ * on exit.
+ *
+ * extents in the log tree have not been allocated out of the extent
+ * tree yet. So, this completes the allocation, taking a reference
+ * as required if the extent already exists or creating a new extent
+ * if it isn't in the extent allocation tree yet.
+ *
+ * The extent is inserted into the file, dropping any existing extents
+ * from the file that overlap the new one.
+ */
+static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct extent_buffer *eb, int slot,
+ struct btrfs_key *key)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ int found_type;
+ u64 extent_end;
+ u64 start = key->offset;
+ u64 nbytes = 0;
+ struct btrfs_file_extent_item *item;
+ struct inode *inode = NULL;
+ unsigned long size;
+ int ret = 0;
+
+ item = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
+ found_type = btrfs_file_extent_type(eb, item);
+
+ if (found_type == BTRFS_FILE_EXTENT_REG ||
+ found_type == BTRFS_FILE_EXTENT_PREALLOC) {
+ nbytes = btrfs_file_extent_num_bytes(eb, item);
+ extent_end = start + nbytes;
+
+ /*
+ * We don't add to the inodes nbytes if we are prealloc or a
+ * hole.
+ */
+ if (btrfs_file_extent_disk_bytenr(eb, item) == 0)
+ nbytes = 0;
+ } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
+ size = btrfs_file_extent_ram_bytes(eb, item);
+ nbytes = btrfs_file_extent_ram_bytes(eb, item);
+ extent_end = ALIGN(start + size,
+ fs_info->sectorsize);
+ } else {
+ ret = 0;
+ goto out;
+ }
+
+ inode = read_one_inode(root, key->objectid);
+ if (!inode) {
+ ret = -EIO;
+ goto out;
+ }
+
+ /*
+ * first check to see if we already have this extent in the
+ * file. This must be done before the btrfs_drop_extents run
+ * so we don't try to drop this extent.
+ */
+ ret = btrfs_lookup_file_extent(trans, root, path,
+ btrfs_ino(BTRFS_I(inode)), start, 0);
+
+ if (ret == 0 &&
+ (found_type == BTRFS_FILE_EXTENT_REG ||
+ found_type == BTRFS_FILE_EXTENT_PREALLOC)) {
+ struct btrfs_file_extent_item cmp1;
+ struct btrfs_file_extent_item cmp2;
+ struct btrfs_file_extent_item *existing;
+ struct extent_buffer *leaf;
+
+ leaf = path->nodes[0];
+ existing = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+
+ read_extent_buffer(eb, &cmp1, (unsigned long)item,
+ sizeof(cmp1));
+ read_extent_buffer(leaf, &cmp2, (unsigned long)existing,
+ sizeof(cmp2));
+
+ /*
+ * we already have a pointer to this exact extent,
+ * we don't have to do anything
+ */
+ if (memcmp(&cmp1, &cmp2, sizeof(cmp1)) == 0) {
+ btrfs_release_path(path);
+ goto out;
+ }
+ }
+ btrfs_release_path(path);
+
+ /* drop any overlapping extents */
+ ret = btrfs_drop_extents(trans, root, inode, start, extent_end, 1);
+ if (ret)
+ goto out;
+
+ if (found_type == BTRFS_FILE_EXTENT_REG ||
+ found_type == BTRFS_FILE_EXTENT_PREALLOC) {
+ u64 offset;
+ unsigned long dest_offset;
+ struct btrfs_key ins;
+
+ if (btrfs_file_extent_disk_bytenr(eb, item) == 0 &&
+ btrfs_fs_incompat(fs_info, NO_HOLES))
+ goto update_inode;
+
+ ret = btrfs_insert_empty_item(trans, root, path, key,
+ sizeof(*item));
+ if (ret)
+ goto out;
+ dest_offset = btrfs_item_ptr_offset(path->nodes[0],
+ path->slots[0]);
+ copy_extent_buffer(path->nodes[0], eb, dest_offset,
+ (unsigned long)item, sizeof(*item));
+
+ ins.objectid = btrfs_file_extent_disk_bytenr(eb, item);
+ ins.offset = btrfs_file_extent_disk_num_bytes(eb, item);
+ ins.type = BTRFS_EXTENT_ITEM_KEY;
+ offset = key->offset - btrfs_file_extent_offset(eb, item);
+
+ /*
+ * Manually record dirty extent, as here we did a shallow
+ * file extent item copy and skip normal backref update,
+ * but modifying extent tree all by ourselves.
+ * So need to manually record dirty extent for qgroup,
+ * as the owner of the file extent changed from log tree
+ * (doesn't affect qgroup) to fs/file tree(affects qgroup)
+ */
+ ret = btrfs_qgroup_trace_extent(trans,
+ btrfs_file_extent_disk_bytenr(eb, item),
+ btrfs_file_extent_disk_num_bytes(eb, item),
+ GFP_NOFS);
+ if (ret < 0)
+ goto out;
+
+ if (ins.objectid > 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
+ */
+ 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,
+ key->objectid, offset);
+ if (ret)
+ goto out;
+ } else {
+ /*
+ * insert the extent pointer in the extent
+ * allocation tree
+ */
+ ret = btrfs_alloc_logged_file_extent(trans,
+ root->root_key.objectid,
+ key->objectid, offset, &ins);
+ if (ret)
+ goto out;
+ }
+ btrfs_release_path(path);
+
+ if (btrfs_file_extent_compression(eb, item)) {
+ csum_start = ins.objectid;
+ csum_end = csum_start + ins.offset;
+ } else {
+ csum_start = ins.objectid +
+ btrfs_file_extent_offset(eb, item);
+ csum_end = csum_start +
+ btrfs_file_extent_num_bytes(eb, item);
+ }
+
+ ret = btrfs_lookup_csums_range(root->log_root,
+ csum_start, csum_end - 1,
+ &ordered_sums, 0);
+ if (ret)
+ goto out;
+ /*
+ * Now delete all existing cums in the csum root that
+ * cover our range. We do this because we can have an
+ * extent that is completely referenced by one file
+ * extent item and partially referenced by another
+ * file extent item (like after using the clone or
+ * extent_same ioctls). In this case if we end up doing
+ * the replay of the one that partially references the
+ * extent first, and we do not do the csum deletion
+ * below, we can get 2 csum items in the csum tree that
+ * overlap each other. For example, imagine our log has
+ * the two following file extent items:
+ *
+ * key (257 EXTENT_DATA 409600)
+ * extent data disk byte 12845056 nr 102400
+ * extent data offset 20480 nr 20480 ram 102400
+ *
+ * key (257 EXTENT_DATA 819200)
+ * extent data disk byte 12845056 nr 102400
+ * extent data offset 0 nr 102400 ram 102400
+ *
+ * Where the second one fully references the 100K extent
+ * that starts at disk byte 12845056, and the log tree
+ * has a single csum item that covers the entire range
+ * of the extent:
+ *
+ * key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100
+ *
+ * After the first file extent item is replayed, the
+ * csum tree gets the following csum item:
+ *
+ * key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20
+ *
+ * Which covers the 20K sub-range starting at offset 20K
+ * of our extent. Now when we replay the second file
+ * extent item, if we do not delete existing csum items
+ * that cover any of its blocks, we end up getting two
+ * csum items in our csum tree that overlap each other:
+ *
+ * key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100
+ * key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20
+ *
+ * Which is a problem, because after this anyone trying
+ * to lookup up for the checksum of any block of our
+ * extent starting at an offset of 40K or higher, will
+ * end up looking at the second csum item only, which
+ * does not contain the checksum for any block starting
+ * at offset 40K or higher of our extent.
+ */
+ while (!list_empty(&ordered_sums)) {
+ struct btrfs_ordered_sum *sums;
+ sums = list_entry(ordered_sums.next,
+ struct btrfs_ordered_sum,
+ list);
+ if (!ret)
+ ret = btrfs_del_csums(trans, fs_info,
+ sums->bytenr,
+ sums->len);
+ if (!ret)
+ ret = btrfs_csum_file_blocks(trans,
+ fs_info->csum_root, sums);
+ list_del(&sums->list);
+ kfree(sums);
+ }
+ if (ret)
+ goto out;
+ } else {
+ btrfs_release_path(path);
+ }
+ } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
+ /* inline extents are easy, we just overwrite them */
+ ret = overwrite_item(trans, root, path, eb, slot, key);
+ if (ret)
+ goto out;
+ }
+
+ inode_add_bytes(inode, nbytes);
+update_inode:
+ ret = btrfs_update_inode(trans, root, inode);
+out:
+ if (inode)
+ iput(inode);
+ return ret;
+}
+
+/*
+ * when cleaning up conflicts between the directory names in the
+ * subvolume, directory names in the log and directory names in the
+ * inode back references, we may have to unlink inodes from directories.
+ *
+ * This is a helper function to do the unlink of a specific directory
+ * item
+ */
+static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_inode *dir,
+ struct btrfs_dir_item *di)
+{
+ struct inode *inode;
+ char *name;
+ int name_len;
+ struct extent_buffer *leaf;
+ struct btrfs_key location;
+ int ret;
+
+ leaf = path->nodes[0];
+
+ btrfs_dir_item_key_to_cpu(leaf, di, &location);
+ name_len = btrfs_dir_name_len(leaf, di);
+ name = kmalloc(name_len, GFP_NOFS);
+ if (!name)
+ return -ENOMEM;
+
+ read_extent_buffer(leaf, name, (unsigned long)(di + 1), name_len);
+ btrfs_release_path(path);
+
+ inode = read_one_inode(root, location.objectid);
+ if (!inode) {
+ ret = -EIO;
+ goto out;
+ }
+
+ ret = link_to_fixup_dir(trans, root, path, location.objectid);
+ if (ret)
+ goto out;
+
+ ret = btrfs_unlink_inode(trans, root, dir, BTRFS_I(inode), name,
+ name_len);
+ if (ret)
+ goto out;
+ else
+ ret = btrfs_run_delayed_items(trans);
+out:
+ kfree(name);
+ iput(inode);
+ return ret;
+}
+
+/*
+ * helper function to see if a given name and sequence number found
+ * in an inode back reference are already in a directory and correctly
+ * point to this inode
+ */
+static noinline int inode_in_dir(struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 dirid, u64 objectid, u64 index,
+ const char *name, int name_len)
+{
+ struct btrfs_dir_item *di;
+ struct btrfs_key location;
+ int match = 0;
+
+ di = btrfs_lookup_dir_index_item(NULL, root, path, dirid,
+ index, name, name_len, 0);
+ if (di && !IS_ERR(di)) {
+ btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
+ if (location.objectid != objectid)
+ goto out;
+ } else
+ goto out;
+ btrfs_release_path(path);
+
+ di = btrfs_lookup_dir_item(NULL, root, path, dirid, name, name_len, 0);
+ if (di && !IS_ERR(di)) {
+ btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
+ if (location.objectid != objectid)
+ goto out;
+ } else
+ goto out;
+ match = 1;
+out:
+ btrfs_release_path(path);
+ return match;
+}
+
+/*
+ * helper function to check a log tree for a named back reference in
+ * an inode. This is used to decide if a back reference that is
+ * found in the subvolume conflicts with what we find in the log.
+ *
+ * inode backreferences may have multiple refs in a single item,
+ * during replay we process one reference at a time, and we don't
+ * want to delete valid links to a file from the subvolume if that
+ * link is also in the log.
+ */
+static noinline int backref_in_log(struct btrfs_root *log,
+ struct btrfs_key *key,
+ u64 ref_objectid,
+ const char *name, int namelen)
+{
+ struct btrfs_path *path;
+ struct btrfs_inode_ref *ref;
+ unsigned long ptr;
+ unsigned long ptr_end;
+ unsigned long name_ptr;
+ int found_name_len;
+ int item_size;
+ int ret;
+ int match = 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ ret = btrfs_search_slot(NULL, log, key, path, 0, 0);
+ if (ret != 0)
+ goto out;
+
+ ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
+
+ if (key->type == BTRFS_INODE_EXTREF_KEY) {
+ if (btrfs_find_name_in_ext_backref(path->nodes[0],
+ path->slots[0],
+ ref_objectid,
+ name, namelen, NULL))
+ match = 1;
+
+ goto out;
+ }
+
+ item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
+ ptr_end = ptr + item_size;
+ while (ptr < ptr_end) {
+ ref = (struct btrfs_inode_ref *)ptr;
+ found_name_len = btrfs_inode_ref_name_len(path->nodes[0], ref);
+ if (found_name_len == namelen) {
+ name_ptr = (unsigned long)(ref + 1);
+ ret = memcmp_extent_buffer(path->nodes[0], name,
+ name_ptr, namelen);
+ if (ret == 0) {
+ match = 1;
+ goto out;
+ }
+ }
+ ptr = (unsigned long)(ref + 1) + found_name_len;
+ }
+out:
+ btrfs_free_path(path);
+ return match;
+}
+
+static inline int __add_inode_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_root *log_root,
+ struct btrfs_inode *dir,
+ struct btrfs_inode *inode,
+ u64 inode_objectid, u64 parent_objectid,
+ u64 ref_index, char *name, int namelen,
+ int *search_done)
+{
+ int ret;
+ char *victim_name;
+ int victim_name_len;
+ struct extent_buffer *leaf;
+ struct btrfs_dir_item *di;
+ struct btrfs_key search_key;
+ struct btrfs_inode_extref *extref;
+
+again:
+ /* Search old style refs */
+ search_key.objectid = inode_objectid;
+ search_key.type = BTRFS_INODE_REF_KEY;
+ search_key.offset = parent_objectid;
+ ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
+ if (ret == 0) {
+ struct btrfs_inode_ref *victim_ref;
+ unsigned long ptr;
+ unsigned long ptr_end;
+
+ leaf = path->nodes[0];
+
+ /* are we trying to overwrite a back ref for the root directory
+ * if so, just jump out, we're done
+ */
+ if (search_key.objectid == search_key.offset)
+ return 1;
+
+ /* check all the names in this back reference to see
+ * if they are in the log. if so, we allow them to stay
+ * otherwise they must be unlinked as a conflict
+ */
+ ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
+ ptr_end = ptr + btrfs_item_size_nr(leaf, path->slots[0]);
+ while (ptr < ptr_end) {
+ victim_ref = (struct btrfs_inode_ref *)ptr;
+ victim_name_len = btrfs_inode_ref_name_len(leaf,
+ victim_ref);
+ victim_name = kmalloc(victim_name_len, GFP_NOFS);
+ if (!victim_name)
+ return -ENOMEM;
+
+ read_extent_buffer(leaf, victim_name,
+ (unsigned long)(victim_ref + 1),
+ victim_name_len);
+
+ if (!backref_in_log(log_root, &search_key,
+ parent_objectid,
+ victim_name,
+ victim_name_len)) {
+ inc_nlink(&inode->vfs_inode);
+ btrfs_release_path(path);
+
+ ret = btrfs_unlink_inode(trans, root, dir, inode,
+ victim_name, victim_name_len);
+ kfree(victim_name);
+ if (ret)
+ return ret;
+ ret = btrfs_run_delayed_items(trans);
+ if (ret)
+ return ret;
+ *search_done = 1;
+ goto again;
+ }
+ kfree(victim_name);
+
+ ptr = (unsigned long)(victim_ref + 1) + victim_name_len;
+ }
+
+ /*
+ * NOTE: we have searched root tree and checked the
+ * corresponding ref, it does not need to check again.
+ */
+ *search_done = 1;
+ }
+ btrfs_release_path(path);
+
+ /* Same search but for extended refs */
+ extref = btrfs_lookup_inode_extref(NULL, root, path, name, namelen,
+ inode_objectid, parent_objectid, 0,
+ 0);
+ if (!IS_ERR_OR_NULL(extref)) {
+ u32 item_size;
+ u32 cur_offset = 0;
+ unsigned long base;
+ struct inode *victim_parent;
+
+ leaf = path->nodes[0];
+
+ item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+ base = btrfs_item_ptr_offset(leaf, path->slots[0]);
+
+ while (cur_offset < item_size) {
+ extref = (struct btrfs_inode_extref *)(base + cur_offset);
+
+ victim_name_len = btrfs_inode_extref_name_len(leaf, extref);
+
+ if (btrfs_inode_extref_parent(leaf, extref) != parent_objectid)
+ goto next;
+
+ victim_name = kmalloc(victim_name_len, GFP_NOFS);
+ if (!victim_name)
+ return -ENOMEM;
+ read_extent_buffer(leaf, victim_name, (unsigned long)&extref->name,
+ victim_name_len);
+
+ search_key.objectid = inode_objectid;
+ search_key.type = BTRFS_INODE_EXTREF_KEY;
+ search_key.offset = btrfs_extref_hash(parent_objectid,
+ victim_name,
+ victim_name_len);
+ ret = 0;
+ if (!backref_in_log(log_root, &search_key,
+ parent_objectid, victim_name,
+ victim_name_len)) {
+ ret = -ENOENT;
+ victim_parent = read_one_inode(root,
+ parent_objectid);
+ if (victim_parent) {
+ inc_nlink(&inode->vfs_inode);
+ btrfs_release_path(path);
+
+ ret = btrfs_unlink_inode(trans, root,
+ BTRFS_I(victim_parent),
+ inode,
+ victim_name,
+ victim_name_len);
+ if (!ret)
+ ret = btrfs_run_delayed_items(
+ trans);
+ }
+ iput(victim_parent);
+ kfree(victim_name);
+ if (ret)
+ return ret;
+ *search_done = 1;
+ goto again;
+ }
+ kfree(victim_name);
+next:
+ cur_offset += victim_name_len + sizeof(*extref);
+ }
+ *search_done = 1;
+ }
+ btrfs_release_path(path);
+
+ /* look for a conflicting sequence number */
+ di = btrfs_lookup_dir_index_item(trans, root, path, btrfs_ino(dir),
+ ref_index, name, namelen, 0);
+ if (di && !IS_ERR(di)) {
+ ret = drop_one_dir_item(trans, root, path, dir, di);
+ if (ret)
+ return ret;
+ }
+ btrfs_release_path(path);
+
+ /* look for a conflicing name */
+ di = btrfs_lookup_dir_item(trans, root, path, btrfs_ino(dir),
+ name, namelen, 0);
+ if (di && !IS_ERR(di)) {
+ ret = drop_one_dir_item(trans, root, path, dir, di);
+ if (ret)
+ return ret;
+ }
+ btrfs_release_path(path);
+
+ return 0;
+}
+
+static int extref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
+ u32 *namelen, char **name, u64 *index,
+ u64 *parent_objectid)
+{
+ struct btrfs_inode_extref *extref;
+
+ extref = (struct btrfs_inode_extref *)ref_ptr;
+
+ *namelen = btrfs_inode_extref_name_len(eb, extref);
+ *name = kmalloc(*namelen, GFP_NOFS);
+ if (*name == NULL)
+ return -ENOMEM;
+
+ read_extent_buffer(eb, *name, (unsigned long)&extref->name,
+ *namelen);
+
+ if (index)
+ *index = btrfs_inode_extref_index(eb, extref);
+ if (parent_objectid)
+ *parent_objectid = btrfs_inode_extref_parent(eb, extref);
+
+ return 0;
+}
+
+static int ref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
+ u32 *namelen, char **name, u64 *index)
+{
+ struct btrfs_inode_ref *ref;
+
+ ref = (struct btrfs_inode_ref *)ref_ptr;
+
+ *namelen = btrfs_inode_ref_name_len(eb, ref);
+ *name = kmalloc(*namelen, GFP_NOFS);
+ if (*name == NULL)
+ return -ENOMEM;
+
+ read_extent_buffer(eb, *name, (unsigned long)(ref + 1), *namelen);
+
+ if (index)
+ *index = btrfs_inode_ref_index(eb, ref);
+
+ return 0;
+}
+
+/*
+ * Take an inode reference item from the log tree and iterate all names from the
+ * inode reference item in the subvolume tree with the same key (if it exists).
+ * For any name that is not in the inode reference item from the log tree, do a
+ * proper unlink of that name (that is, remove its entry from the inode
+ * reference item and both dir index keys).
+ */
+static int unlink_old_inode_refs(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_inode *inode,
+ struct extent_buffer *log_eb,
+ int log_slot,
+ struct btrfs_key *key)
+{
+ int ret;
+ unsigned long ref_ptr;
+ unsigned long ref_end;
+ struct extent_buffer *eb;
+
+again:
+ btrfs_release_path(path);
+ ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
+ if (ret > 0) {
+ ret = 0;
+ goto out;
+ }
+ if (ret < 0)
+ goto out;
+
+ eb = path->nodes[0];
+ ref_ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
+ ref_end = ref_ptr + btrfs_item_size_nr(eb, path->slots[0]);
+ while (ref_ptr < ref_end) {
+ char *name = NULL;
+ int namelen;
+ u64 parent_id;
+
+ if (key->type == BTRFS_INODE_EXTREF_KEY) {
+ ret = extref_get_fields(eb, ref_ptr, &namelen, &name,
+ NULL, &parent_id);
+ } else {
+ parent_id = key->offset;
+ ret = ref_get_fields(eb, ref_ptr, &namelen, &name,
+ NULL);
+ }
+ if (ret)
+ 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);
+ else
+ ret = btrfs_find_name_in_backref(log_eb, log_slot, name,
+ namelen, NULL);
+
+ if (!ret) {
+ struct inode *dir;
+
+ btrfs_release_path(path);
+ dir = read_one_inode(root, parent_id);
+ if (!dir) {
+ ret = -ENOENT;
+ kfree(name);
+ goto out;
+ }
+ ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
+ inode, name, namelen);
+ kfree(name);
+ iput(dir);
+ if (ret)
+ goto out;
+ goto again;
+ }
+
+ kfree(name);
+ ref_ptr += namelen;
+ if (key->type == BTRFS_INODE_EXTREF_KEY)
+ ref_ptr += sizeof(struct btrfs_inode_extref);
+ else
+ ref_ptr += sizeof(struct btrfs_inode_ref);
+ }
+ ret = 0;
+ out:
+ btrfs_release_path(path);
+ return ret;
+}
+
+static int btrfs_inode_ref_exists(struct inode *inode, struct inode *dir,
+ const u8 ref_type, const char *name,
+ const int namelen)
+{
+ struct btrfs_key key;
+ struct btrfs_path *path;
+ const u64 parent_id = btrfs_ino(BTRFS_I(dir));
+ int ret;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ key.objectid = btrfs_ino(BTRFS_I(inode));
+ key.type = ref_type;
+ if (key.type == BTRFS_INODE_REF_KEY)
+ key.offset = parent_id;
+ else
+ key.offset = btrfs_extref_hash(parent_id, name, namelen);
+
+ ret = btrfs_search_slot(NULL, BTRFS_I(inode)->root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) {
+ ret = 0;
+ 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);
+ else
+ ret = btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
+ name, namelen, NULL);
+
+out:
+ 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.
+ * root is the destination we are replaying into, and path is for temp
+ * use by this function. (it should be released on return).
+ */
+static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_root *log,
+ struct btrfs_path *path,
+ struct extent_buffer *eb, int slot,
+ struct btrfs_key *key)
+{
+ struct inode *dir = NULL;
+ struct inode *inode = NULL;
+ unsigned long ref_ptr;
+ unsigned long ref_end;
+ char *name = NULL;
+ int namelen;
+ int ret;
+ int search_done = 0;
+ int log_ref_ver = 0;
+ u64 parent_objectid;
+ u64 inode_objectid;
+ u64 ref_index = 0;
+ int ref_struct_size;
+
+ ref_ptr = btrfs_item_ptr_offset(eb, slot);
+ ref_end = ref_ptr + btrfs_item_size_nr(eb, slot);
+
+ if (key->type == BTRFS_INODE_EXTREF_KEY) {
+ struct btrfs_inode_extref *r;
+
+ ref_struct_size = sizeof(struct btrfs_inode_extref);
+ log_ref_ver = 1;
+ r = (struct btrfs_inode_extref *)ref_ptr;
+ parent_objectid = btrfs_inode_extref_parent(eb, r);
+ } else {
+ ref_struct_size = sizeof(struct btrfs_inode_ref);
+ parent_objectid = key->offset;
+ }
+ inode_objectid = key->objectid;
+
+ /*
+ * it is possible that we didn't log all the parent directories
+ * for a given inode. If we don't find the dir, just don't
+ * copy the back ref in. The link count fixup code will take
+ * care of the rest
+ */
+ dir = read_one_inode(root, parent_objectid);
+ if (!dir) {
+ ret = -ENOENT;
+ goto out;
+ }
+
+ inode = read_one_inode(root, inode_objectid);
+ if (!inode) {
+ ret = -EIO;
+ goto out;
+ }
+
+ while (ref_ptr < ref_end) {
+ if (log_ref_ver) {
+ ret = extref_get_fields(eb, ref_ptr, &namelen, &name,
+ &ref_index, &parent_objectid);
+ /*
+ * parent object can change from one array
+ * item to another.
+ */
+ if (!dir)
+ dir = read_one_inode(root, parent_objectid);
+ if (!dir) {
+ ret = -ENOENT;
+ goto out;
+ }
+ } else {
+ ret = ref_get_fields(eb, ref_ptr, &namelen, &name,
+ &ref_index);
+ }
+ if (ret)
+ goto out;
+
+ /* if we already have a perfect match, we're done */
+ if (!inode_in_dir(root, path, btrfs_ino(BTRFS_I(dir)),
+ btrfs_ino(BTRFS_I(inode)), ref_index,
+ name, namelen)) {
+ /*
+ * look for a conflicting back reference in the
+ * metadata. if we find one we have to unlink that name
+ * of the file before we add our new link. Later on, we
+ * overwrite any existing back reference, and we don't
+ * want to create dangling pointers in the directory.
+ */
+
+ if (!search_done) {
+ ret = __add_inode_ref(trans, root, path, log,
+ BTRFS_I(dir),
+ BTRFS_I(inode),
+ inode_objectid,
+ parent_objectid,
+ ref_index, name, namelen,
+ &search_done);
+ if (ret) {
+ if (ret == 1)
+ ret = 0;
+ goto out;
+ }
+ }
+
+ /*
+ * If a reference item already exists for this inode
+ * with the same parent and name, but different index,
+ * drop it and the corresponding directory index entries
+ * from the parent before adding the new reference item
+ * and dir index entries, otherwise we would fail with
+ * -EEXIST returned from btrfs_add_link() below.
+ */
+ ret = btrfs_inode_ref_exists(inode, dir, key->type,
+ name, namelen);
+ if (ret > 0) {
+ ret = btrfs_unlink_inode(trans, root,
+ BTRFS_I(dir),
+ BTRFS_I(inode),
+ name, namelen);
+ /*
+ * 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 (!ret && inode->i_nlink == 0)
+ inc_nlink(inode);
+ }
+ if (ret < 0)
+ goto out;
+
+ /* insert our name */
+ ret = btrfs_add_link(trans, BTRFS_I(dir),
+ BTRFS_I(inode),
+ name, namelen, 0, ref_index);
+ if (ret)
+ goto out;
+
+ btrfs_update_inode(trans, root, inode);
+ }
+
+ ref_ptr = (unsigned long)(ref_ptr + ref_struct_size) + namelen;
+ kfree(name);
+ name = NULL;
+ if (log_ref_ver) {
+ iput(dir);
+ dir = NULL;
+ }
+ }
+
+ /*
+ * Before we overwrite the inode reference item in the subvolume tree
+ * with the item from the log tree, we must unlink all names from the
+ * parent directory that are in the subvolume's tree inode reference
+ * item, otherwise we end up with an inconsistent subvolume tree where
+ * dir index entries exist for a name but there is no inode reference
+ * item with the same name.
+ */
+ ret = unlink_old_inode_refs(trans, root, path, BTRFS_I(inode), eb, slot,
+ key);
+ if (ret)
+ goto out;
+
+ /* finally write the back reference in the inode */
+ ret = overwrite_item(trans, root, path, eb, slot, key);
+out:
+ btrfs_release_path(path);
+ kfree(name);
+ iput(dir);
+ iput(inode);
+ return ret;
+}
+
+static int insert_orphan_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 ino)
+{
+ int ret;
+
+ ret = btrfs_insert_orphan_item(trans, root, ino);
+ if (ret == -EEXIST)
+ ret = 0;
+
+ return ret;
+}
+
+static int count_inode_extrefs(struct btrfs_root *root,
+ struct btrfs_inode *inode, struct btrfs_path *path)
+{
+ int ret = 0;
+ int name_len;
+ unsigned int nlink = 0;
+ u32 item_size;
+ u32 cur_offset = 0;
+ u64 inode_objectid = btrfs_ino(inode);
+ u64 offset = 0;
+ unsigned long ptr;
+ struct btrfs_inode_extref *extref;
+ struct extent_buffer *leaf;
+
+ while (1) {
+ ret = btrfs_find_one_extref(root, inode_objectid, offset, path,
+ &extref, &offset);
+ if (ret)
+ break;
+
+ leaf = path->nodes[0];
+ item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+ ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
+ cur_offset = 0;
+
+ while (cur_offset < item_size) {
+ extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
+ name_len = btrfs_inode_extref_name_len(leaf, extref);
+
+ nlink++;
+
+ cur_offset += name_len + sizeof(*extref);
+ }
+
+ offset++;
+ btrfs_release_path(path);
+ }
+ btrfs_release_path(path);
+
+ if (ret < 0 && ret != -ENOENT)
+ return ret;
+ return nlink;
+}
+
+static int count_inode_refs(struct btrfs_root *root,
+ struct btrfs_inode *inode, struct btrfs_path *path)
+{
+ int ret;
+ struct btrfs_key key;
+ unsigned int nlink = 0;
+ unsigned long ptr;
+ unsigned long ptr_end;
+ int name_len;
+ u64 ino = btrfs_ino(inode);
+
+ key.objectid = ino;
+ key.type = BTRFS_INODE_REF_KEY;
+ key.offset = (u64)-1;
+
+ while (1) {
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ break;
+ if (ret > 0) {
+ if (path->slots[0] == 0)
+ break;
+ path->slots[0]--;
+ }
+process_slot:
+ btrfs_item_key_to_cpu(path->nodes[0], &key,
+ path->slots[0]);
+ if (key.objectid != ino ||
+ key.type != BTRFS_INODE_REF_KEY)
+ break;
+ ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
+ ptr_end = ptr + btrfs_item_size_nr(path->nodes[0],
+ path->slots[0]);
+ while (ptr < ptr_end) {
+ struct btrfs_inode_ref *ref;
+
+ ref = (struct btrfs_inode_ref *)ptr;
+ name_len = btrfs_inode_ref_name_len(path->nodes[0],
+ ref);
+ ptr = (unsigned long)(ref + 1) + name_len;
+ nlink++;
+ }
+
+ if (key.offset == 0)
+ break;
+ if (path->slots[0] > 0) {
+ path->slots[0]--;
+ goto process_slot;
+ }
+ key.offset--;
+ btrfs_release_path(path);
+ }
+ btrfs_release_path(path);
+
+ return nlink;
+}
+
+/*
+ * There are a few corners where the link count of the file can't
+ * be properly maintained during replay. So, instead of adding
+ * lots of complexity to the log code, we just scan the backrefs
+ * for any file that has been through replay.
+ *
+ * The scan will update the link count on the inode to reflect the
+ * number of back refs found. If it goes down to zero, the iput
+ * will free the inode.
+ */
+static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *inode)
+{
+ struct btrfs_path *path;
+ int ret;
+ u64 nlink = 0;
+ u64 ino = btrfs_ino(BTRFS_I(inode));
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ ret = count_inode_refs(root, BTRFS_I(inode), path);
+ if (ret < 0)
+ goto out;
+
+ nlink = ret;
+
+ ret = count_inode_extrefs(root, BTRFS_I(inode), path);
+ if (ret < 0)
+ goto out;
+
+ nlink += ret;
+
+ ret = 0;
+
+ if (nlink != inode->i_nlink) {
+ set_nlink(inode, nlink);
+ btrfs_update_inode(trans, root, inode);
+ }
+ BTRFS_I(inode)->index_cnt = (u64)-1;
+
+ if (inode->i_nlink == 0) {
+ if (S_ISDIR(inode->i_mode)) {
+ ret = replay_dir_deletes(trans, root, NULL, path,
+ ino, 1);
+ if (ret)
+ goto out;
+ }
+ ret = insert_orphan_item(trans, root, ino);
+ }
+
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path)
+{
+ int ret;
+ struct btrfs_key key;
+ struct inode *inode;
+
+ key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
+ key.type = BTRFS_ORPHAN_ITEM_KEY;
+ key.offset = (u64)-1;
+ while (1) {
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret < 0)
+ break;
+
+ if (ret == 1) {
+ if (path->slots[0] == 0)
+ break;
+ path->slots[0]--;
+ }
+
+ btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+ if (key.objectid != BTRFS_TREE_LOG_FIXUP_OBJECTID ||
+ key.type != BTRFS_ORPHAN_ITEM_KEY)
+ break;
+
+ ret = btrfs_del_item(trans, root, path);
+ if (ret)
+ goto out;
+
+ btrfs_release_path(path);
+ inode = read_one_inode(root, key.offset);
+ if (!inode)
+ return -EIO;
+
+ ret = fixup_inode_link_count(trans, root, inode);
+ iput(inode);
+ if (ret)
+ goto out;
+
+ /*
+ * fixup on a directory may create new entries,
+ * make sure we always look for the highset possible
+ * offset
+ */
+ key.offset = (u64)-1;
+ }
+ ret = 0;
+out:
+ btrfs_release_path(path);
+ return ret;
+}
+
+
+/*
+ * record a given inode in the fixup dir so we can check its link
+ * count when replay is done. The link count is incremented here
+ * so the inode won't go away until we check it
+ */
+static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 objectid)
+{
+ struct btrfs_key key;
+ int ret = 0;
+ struct inode *inode;
+
+ inode = read_one_inode(root, objectid);
+ if (!inode)
+ return -EIO;
+
+ key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
+ key.type = BTRFS_ORPHAN_ITEM_KEY;
+ key.offset = objectid;
+
+ ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
+
+ btrfs_release_path(path);
+ if (ret == 0) {
+ if (!inode->i_nlink)
+ set_nlink(inode, 1);
+ else
+ inc_nlink(inode);
+ ret = btrfs_update_inode(trans, root, inode);
+ } else if (ret == -EEXIST) {
+ ret = 0;
+ } else {
+ BUG(); /* Logic Error */
+ }
+ iput(inode);
+
+ return ret;
+}
+
+/*
+ * when replaying the log for a directory, we only insert names
+ * for inodes that actually exist. This means an fsync on a directory
+ * does not implicitly fsync all the new files in it
+ */
+static noinline int insert_one_name(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 dirid, u64 index,
+ char *name, int name_len,
+ struct btrfs_key *location)
+{
+ struct inode *inode;
+ struct inode *dir;
+ int ret;
+
+ inode = read_one_inode(root, location->objectid);
+ if (!inode)
+ return -ENOENT;
+
+ dir = read_one_inode(root, dirid);
+ if (!dir) {
+ iput(inode);
+ return -EIO;
+ }
+
+ ret = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode), name,
+ name_len, 1, index);
+
+ /* FIXME, put inode into FIXUP list */
+
+ iput(inode);
+ iput(dir);
+ return ret;
+}
+
+/*
+ * Return true if an inode reference exists in the log for the given name,
+ * inode and parent inode.
+ */
+static bool name_in_log_ref(struct btrfs_root *log_root,
+ const char *name, const int name_len,
+ const u64 dirid, const u64 ino)
+{
+ struct btrfs_key search_key;
+
+ search_key.objectid = ino;
+ search_key.type = BTRFS_INODE_REF_KEY;
+ search_key.offset = dirid;
+ if (backref_in_log(log_root, &search_key, dirid, name, name_len))
+ return true;
+
+ search_key.type = BTRFS_INODE_EXTREF_KEY;
+ search_key.offset = btrfs_extref_hash(dirid, name, name_len);
+ if (backref_in_log(log_root, &search_key, dirid, name, name_len))
+ return true;
+
+ return false;
+}
+
+/*
+ * take a single entry in a log directory item and replay it into
+ * the subvolume.
+ *
+ * if a conflicting item exists in the subdirectory already,
+ * the inode it points to is unlinked and put into the link count
+ * fix up tree.
+ *
+ * If a name from the log points to a file or directory that does
+ * not exist in the FS, it is skipped. fsyncs on directories
+ * do not force down inodes inside that directory, just changes to the
+ * names or unlinks in a directory.
+ *
+ * Returns < 0 on error, 0 if the name wasn't replayed (dentry points to a
+ * non-existing inode) and 1 if the name was replayed.
+ */
+static noinline int replay_one_name(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct extent_buffer *eb,
+ struct btrfs_dir_item *di,
+ struct btrfs_key *key)
+{
+ char *name;
+ int name_len;
+ struct btrfs_dir_item *dst_di;
+ struct btrfs_key found_key;
+ struct btrfs_key log_key;
+ struct inode *dir;
+ u8 log_type;
+ int exists;
+ int ret = 0;
+ bool update_size = (key->type == BTRFS_DIR_INDEX_KEY);
+ bool name_added = false;
+
+ dir = read_one_inode(root, key->objectid);
+ if (!dir)
+ return -EIO;
+
+ name_len = btrfs_dir_name_len(eb, di);
+ name = kmalloc(name_len, GFP_NOFS);
+ if (!name) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ log_type = btrfs_dir_type(eb, di);
+ read_extent_buffer(eb, name, (unsigned long)(di + 1),
+ name_len);
+
+ btrfs_dir_item_key_to_cpu(eb, di, &log_key);
+ exists = btrfs_lookup_inode(trans, root, path, &log_key, 0);
+ if (exists == 0)
+ exists = 1;
+ else
+ exists = 0;
+ btrfs_release_path(path);
+
+ if (key->type == BTRFS_DIR_ITEM_KEY) {
+ dst_di = btrfs_lookup_dir_item(trans, root, path, key->objectid,
+ name, name_len, 1);
+ } else if (key->type == BTRFS_DIR_INDEX_KEY) {
+ dst_di = btrfs_lookup_dir_index_item(trans, root, path,
+ key->objectid,
+ key->offset, name,
+ name_len, 1);
+ } else {
+ /* Corruption */
+ ret = -EINVAL;
+ goto out;
+ }
+ if (IS_ERR_OR_NULL(dst_di)) {
+ /* we need a sequence number to insert, so we only
+ * do inserts for the BTRFS_DIR_INDEX_KEY types
+ */
+ if (key->type != BTRFS_DIR_INDEX_KEY)
+ goto out;
+ goto insert;
+ }
+
+ btrfs_dir_item_key_to_cpu(path->nodes[0], dst_di, &found_key);
+ /* the existing item matches the logged item */
+ if (found_key.objectid == log_key.objectid &&
+ found_key.type == log_key.type &&
+ found_key.offset == log_key.offset &&
+ btrfs_dir_type(path->nodes[0], dst_di) == log_type) {
+ update_size = false;
+ goto out;
+ }
+
+ /*
+ * don't drop the conflicting directory entry if the inode
+ * for the new entry doesn't exist
+ */
+ if (!exists)
+ goto out;
+
+ ret = drop_one_dir_item(trans, root, path, BTRFS_I(dir), dst_di);
+ if (ret)
+ goto out;
+
+ if (key->type == BTRFS_DIR_INDEX_KEY)
+ goto insert;
+out:
+ btrfs_release_path(path);
+ if (!ret && update_size) {
+ btrfs_i_size_write(BTRFS_I(dir), dir->i_size + name_len * 2);
+ ret = btrfs_update_inode(trans, root, dir);
+ }
+ kfree(name);
+ iput(dir);
+ if (!ret && name_added)
+ ret = 1;
+ return ret;
+
+insert:
+ if (name_in_log_ref(root->log_root, name, name_len,
+ key->objectid, log_key.objectid)) {
+ /* The dentry will be added later. */
+ ret = 0;
+ update_size = false;
+ goto out;
+ }
+ btrfs_release_path(path);
+ ret = insert_one_name(trans, root, key->objectid, key->offset,
+ name, name_len, &log_key);
+ if (ret && ret != -ENOENT && ret != -EEXIST)
+ goto out;
+ if (!ret)
+ name_added = true;
+ update_size = false;
+ ret = 0;
+ goto out;
+}
+
+/*
+ * find all the names in a directory item and reconcile them into
+ * the subvolume. Only BTRFS_DIR_ITEM_KEY types will have more than
+ * one name in a directory item, but the same code gets used for
+ * both directory index types
+ */
+static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct extent_buffer *eb, int slot,
+ struct btrfs_key *key)
+{
+ int ret = 0;
+ u32 item_size = btrfs_item_size_nr(eb, slot);
+ struct btrfs_dir_item *di;
+ int name_len;
+ unsigned long ptr;
+ unsigned long ptr_end;
+ struct btrfs_path *fixup_path = NULL;
+
+ ptr = btrfs_item_ptr_offset(eb, slot);
+ ptr_end = ptr + item_size;
+ while (ptr < ptr_end) {
+ di = (struct btrfs_dir_item *)ptr;
+ name_len = btrfs_dir_name_len(eb, di);
+ ret = replay_one_name(trans, root, path, eb, di, key);
+ if (ret < 0)
+ break;
+ ptr = (unsigned long)(di + 1);
+ ptr += name_len;
+
+ /*
+ * If this entry refers to a non-directory (directories can not
+ * have a link count > 1) and it was added in the transaction
+ * that was not committed, make sure we fixup the link count of
+ * the inode it the entry points to. Otherwise something like
+ * the following would result in a directory pointing to an
+ * inode with a wrong link that does not account for this dir
+ * entry:
+ *
+ * mkdir testdir
+ * touch testdir/foo
+ * touch testdir/bar
+ * sync
+ *
+ * ln testdir/bar testdir/bar_link
+ * ln testdir/foo testdir/foo_link
+ * xfs_io -c "fsync" testdir/bar
+ *
+ * <power failure>
+ *
+ * mount fs, log replay happens
+ *
+ * File foo would remain with a link count of 1 when it has two
+ * entries pointing to it in the directory testdir. This would
+ * make it impossible to ever delete the parent directory has
+ * it would result in stale dentries that can never be deleted.
+ */
+ if (ret == 1 && btrfs_dir_type(eb, di) != BTRFS_FT_DIR) {
+ struct btrfs_key di_key;
+
+ if (!fixup_path) {
+ fixup_path = btrfs_alloc_path();
+ if (!fixup_path) {
+ ret = -ENOMEM;
+ break;
+ }
+ }
+
+ btrfs_dir_item_key_to_cpu(eb, di, &di_key);
+ ret = link_to_fixup_dir(trans, root, fixup_path,
+ di_key.objectid);
+ if (ret)
+ break;
+ }
+ ret = 0;
+ }
+ btrfs_free_path(fixup_path);
+ return ret;
+}
+
+/*
+ * directory replay has two parts. There are the standard directory
+ * items in the log copied from the subvolume, and range items
+ * created in the log while the subvolume was logged.
+ *
+ * The range items tell us which parts of the key space the log
+ * is authoritative for. During replay, if a key in the subvolume
+ * directory is in a logged range item, but not actually in the log
+ * that means it was deleted from the directory before the fsync
+ * and should be removed.
+ */
+static noinline int find_dir_range(struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 dirid, int key_type,
+ u64 *start_ret, u64 *end_ret)
+{
+ struct btrfs_key key;
+ u64 found_end;
+ struct btrfs_dir_log_item *item;
+ int ret;
+ int nritems;
+
+ if (*start_ret == (u64)-1)
+ return 1;
+
+ key.objectid = dirid;
+ key.type = key_type;
+ key.offset = *start_ret;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) {
+ if (path->slots[0] == 0)
+ goto out;
+ path->slots[0]--;
+ }
+ if (ret != 0)
+ btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+
+ if (key.type != key_type || key.objectid != dirid) {
+ ret = 1;
+ goto next;
+ }
+ item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_dir_log_item);
+ found_end = btrfs_dir_log_end(path->nodes[0], item);
+
+ if (*start_ret >= key.offset && *start_ret <= found_end) {
+ ret = 0;
+ *start_ret = key.offset;
+ *end_ret = found_end;
+ goto out;
+ }
+ ret = 1;
+next:
+ /* check the next slot in the tree to see if it is a valid item */
+ nritems = btrfs_header_nritems(path->nodes[0]);
+ path->slots[0]++;
+ if (path->slots[0] >= nritems) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret)
+ goto out;
+ }
+
+ btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+
+ if (key.type != key_type || key.objectid != dirid) {
+ ret = 1;
+ goto out;
+ }
+ item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_dir_log_item);
+ found_end = btrfs_dir_log_end(path->nodes[0], item);
+ *start_ret = key.offset;
+ *end_ret = found_end;
+ ret = 0;
+out:
+ btrfs_release_path(path);
+ return ret;
+}
+
+/*
+ * this looks for a given directory item in the log. If the directory
+ * item is not in the log, the item is removed and the inode it points
+ * to is unlinked
+ */
+static noinline int check_item_in_log(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_root *log,
+ struct btrfs_path *path,
+ struct btrfs_path *log_path,
+ struct inode *dir,
+ struct btrfs_key *dir_key)
+{
+ int ret;
+ struct extent_buffer *eb;
+ int slot;
+ u32 item_size;
+ struct btrfs_dir_item *di;
+ struct btrfs_dir_item *log_di;
+ int name_len;
+ unsigned long ptr;
+ unsigned long ptr_end;
+ char *name;
+ struct inode *inode;
+ struct btrfs_key location;
+
+again:
+ eb = path->nodes[0];
+ slot = path->slots[0];
+ item_size = btrfs_item_size_nr(eb, slot);
+ ptr = btrfs_item_ptr_offset(eb, slot);
+ ptr_end = ptr + item_size;
+ while (ptr < ptr_end) {
+ di = (struct btrfs_dir_item *)ptr;
+ name_len = btrfs_dir_name_len(eb, di);
+ name = kmalloc(name_len, GFP_NOFS);
+ if (!name) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ read_extent_buffer(eb, name, (unsigned long)(di + 1),
+ name_len);
+ log_di = NULL;
+ if (log && dir_key->type == BTRFS_DIR_ITEM_KEY) {
+ log_di = btrfs_lookup_dir_item(trans, log, log_path,
+ dir_key->objectid,
+ name, name_len, 0);
+ } else if (log && dir_key->type == BTRFS_DIR_INDEX_KEY) {
+ log_di = btrfs_lookup_dir_index_item(trans, log,
+ log_path,
+ dir_key->objectid,
+ dir_key->offset,
+ name, name_len, 0);
+ }
+ if (!log_di || log_di == ERR_PTR(-ENOENT)) {
+ btrfs_dir_item_key_to_cpu(eb, di, &location);
+ btrfs_release_path(path);
+ btrfs_release_path(log_path);
+ inode = read_one_inode(root, location.objectid);
+ if (!inode) {
+ kfree(name);
+ return -EIO;
+ }
+
+ ret = link_to_fixup_dir(trans, root,
+ path, location.objectid);
+ if (ret) {
+ kfree(name);
+ iput(inode);
+ goto out;
+ }
+
+ inc_nlink(inode);
+ ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
+ BTRFS_I(inode), name, name_len);
+ if (!ret)
+ ret = btrfs_run_delayed_items(trans);
+ kfree(name);
+ iput(inode);
+ if (ret)
+ goto out;
+
+ /* there might still be more names under this key
+ * check and repeat if required
+ */
+ ret = btrfs_search_slot(NULL, root, dir_key, path,
+ 0, 0);
+ if (ret == 0)
+ goto again;
+ ret = 0;
+ goto out;
+ } else if (IS_ERR(log_di)) {
+ kfree(name);
+ return PTR_ERR(log_di);
+ }
+ btrfs_release_path(log_path);
+ kfree(name);
+
+ ptr = (unsigned long)(di + 1);
+ ptr += name_len;
+ }
+ ret = 0;
+out:
+ btrfs_release_path(path);
+ btrfs_release_path(log_path);
+ return ret;
+}
+
+static int replay_xattr_deletes(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_root *log,
+ struct btrfs_path *path,
+ const u64 ino)
+{
+ struct btrfs_key search_key;
+ struct btrfs_path *log_path;
+ int i;
+ int nritems;
+ int ret;
+
+ log_path = btrfs_alloc_path();
+ if (!log_path)
+ return -ENOMEM;
+
+ search_key.objectid = ino;
+ search_key.type = BTRFS_XATTR_ITEM_KEY;
+ search_key.offset = 0;
+again:
+ ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+process_leaf:
+ nritems = btrfs_header_nritems(path->nodes[0]);
+ for (i = path->slots[0]; i < nritems; i++) {
+ struct btrfs_key key;
+ struct btrfs_dir_item *di;
+ struct btrfs_dir_item *log_di;
+ u32 total_size;
+ u32 cur;
+
+ btrfs_item_key_to_cpu(path->nodes[0], &key, i);
+ if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY) {
+ ret = 0;
+ goto out;
+ }
+
+ di = btrfs_item_ptr(path->nodes[0], i, struct btrfs_dir_item);
+ total_size = btrfs_item_size_nr(path->nodes[0], i);
+ cur = 0;
+ while (cur < total_size) {
+ u16 name_len = btrfs_dir_name_len(path->nodes[0], di);
+ u16 data_len = btrfs_dir_data_len(path->nodes[0], di);
+ u32 this_len = sizeof(*di) + name_len + data_len;
+ char *name;
+
+ name = kmalloc(name_len, GFP_NOFS);
+ if (!name) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ read_extent_buffer(path->nodes[0], name,
+ (unsigned long)(di + 1), name_len);
+
+ log_di = btrfs_lookup_xattr(NULL, log, log_path, ino,
+ name, name_len, 0);
+ btrfs_release_path(log_path);
+ if (!log_di) {
+ /* Doesn't exist in log tree, so delete it. */
+ btrfs_release_path(path);
+ di = btrfs_lookup_xattr(trans, root, path, ino,
+ name, name_len, -1);
+ kfree(name);
+ if (IS_ERR(di)) {
+ ret = PTR_ERR(di);
+ goto out;
+ }
+ ASSERT(di);
+ ret = btrfs_delete_one_dir_name(trans, root,
+ path, di);
+ if (ret)
+ goto out;
+ btrfs_release_path(path);
+ search_key = key;
+ goto again;
+ }
+ kfree(name);
+ if (IS_ERR(log_di)) {
+ ret = PTR_ERR(log_di);
+ goto out;
+ }
+ cur += this_len;
+ di = (struct btrfs_dir_item *)((char *)di + this_len);
+ }
+ }
+ ret = btrfs_next_leaf(root, path);
+ if (ret > 0)
+ ret = 0;
+ else if (ret == 0)
+ goto process_leaf;
+out:
+ btrfs_free_path(log_path);
+ btrfs_release_path(path);
+ return ret;
+}
+
+
+/*
+ * deletion replay happens before we copy any new directory items
+ * out of the log or out of backreferences from inodes. It
+ * scans the log to find ranges of keys that log is authoritative for,
+ * and then scans the directory to find items in those ranges that are
+ * not present in the log.
+ *
+ * Anything we don't find in the log is unlinked and removed from the
+ * directory.
+ */
+static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_root *log,
+ struct btrfs_path *path,
+ u64 dirid, int del_all)
+{
+ u64 range_start;
+ u64 range_end;
+ int key_type = BTRFS_DIR_LOG_ITEM_KEY;
+ int ret = 0;
+ struct btrfs_key dir_key;
+ struct btrfs_key found_key;
+ struct btrfs_path *log_path;
+ struct inode *dir;
+
+ dir_key.objectid = dirid;
+ dir_key.type = BTRFS_DIR_ITEM_KEY;
+ log_path = btrfs_alloc_path();
+ if (!log_path)
+ return -ENOMEM;
+
+ dir = read_one_inode(root, dirid);
+ /* it isn't an error if the inode isn't there, that can happen
+ * because we replay the deletes before we copy in the inode item
+ * from the log
+ */
+ if (!dir) {
+ btrfs_free_path(log_path);
+ return 0;
+ }
+again:
+ range_start = 0;
+ range_end = 0;
+ while (1) {
+ if (del_all)
+ range_end = (u64)-1;
+ else {
+ ret = find_dir_range(log, path, dirid, key_type,
+ &range_start, &range_end);
+ if (ret != 0)
+ break;
+ }
+
+ dir_key.offset = range_start;
+ while (1) {
+ int nritems;
+ ret = btrfs_search_slot(NULL, root, &dir_key, path,
+ 0, 0);
+ if (ret < 0)
+ goto out;
+
+ nritems = btrfs_header_nritems(path->nodes[0]);
+ if (path->slots[0] >= nritems) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret == 1)
+ break;
+ else if (ret < 0)
+ goto out;
+ }
+ btrfs_item_key_to_cpu(path->nodes[0], &found_key,
+ path->slots[0]);
+ if (found_key.objectid != dirid ||
+ found_key.type != dir_key.type)
+ goto next_type;
+
+ if (found_key.offset > range_end)
+ break;
+
+ ret = check_item_in_log(trans, root, log, path,
+ log_path, dir,
+ &found_key);
+ if (ret)
+ goto out;
+ if (found_key.offset == (u64)-1)
+ break;
+ dir_key.offset = found_key.offset + 1;
+ }
+ btrfs_release_path(path);
+ if (range_end == (u64)-1)
+ break;
+ range_start = range_end + 1;
+ }
+
+next_type:
+ ret = 0;
+ if (key_type == BTRFS_DIR_LOG_ITEM_KEY) {
+ key_type = BTRFS_DIR_LOG_INDEX_KEY;
+ dir_key.type = BTRFS_DIR_INDEX_KEY;
+ btrfs_release_path(path);
+ goto again;
+ }
+out:
+ btrfs_release_path(path);
+ btrfs_free_path(log_path);
+ iput(dir);
+ return ret;
+}
+
+/*
+ * the process_func used to replay items from the log tree. This
+ * gets called in two different stages. The first stage just looks
+ * for inodes and makes sure they are all copied into the subvolume.
+ *
+ * The second stage copies all the other item types from the log into
+ * the subvolume. The two stage approach is slower, but gets rid of
+ * lots of complexity around inodes referencing other inodes that exist
+ * only in the log (references come from either directory items or inode
+ * back refs).
+ */
+static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
+ struct walk_control *wc, u64 gen, int level)
+{
+ int nritems;
+ struct btrfs_path *path;
+ struct btrfs_root *root = wc->replay_dest;
+ struct btrfs_key key;
+ int i;
+ int ret;
+
+ ret = btrfs_read_buffer(eb, gen, level, NULL);
+ if (ret)
+ return ret;
+
+ level = btrfs_header_level(eb);
+
+ if (level != 0)
+ return 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ nritems = btrfs_header_nritems(eb);
+ for (i = 0; i < nritems; i++) {
+ btrfs_item_key_to_cpu(eb, &key, i);
+
+ /* inode keys are done during the first stage */
+ if (key.type == BTRFS_INODE_ITEM_KEY &&
+ wc->stage == LOG_WALK_REPLAY_INODES) {
+ struct btrfs_inode_item *inode_item;
+ u32 mode;
+
+ inode_item = btrfs_item_ptr(eb, i,
+ struct btrfs_inode_item);
+ /*
+ * If we have a tmpfile (O_TMPFILE) that got fsync'ed
+ * and never got linked before the fsync, skip it, as
+ * replaying it is pointless since it would be deleted
+ * later. We skip logging tmpfiles, but it's always
+ * possible we are replaying a log created with a kernel
+ * that used to log tmpfiles.
+ */
+ if (btrfs_inode_nlink(eb, inode_item) == 0) {
+ wc->ignore_cur_inode = true;
+ continue;
+ } else {
+ wc->ignore_cur_inode = false;
+ }
+ ret = replay_xattr_deletes(wc->trans, root, log,
+ path, key.objectid);
+ if (ret)
+ break;
+ mode = btrfs_inode_mode(eb, inode_item);
+ if (S_ISDIR(mode)) {
+ ret = replay_dir_deletes(wc->trans,
+ root, log, path, key.objectid, 0);
+ if (ret)
+ break;
+ }
+ ret = overwrite_item(wc->trans, root, path,
+ eb, i, &key);
+ if (ret)
+ break;
+
+ /*
+ * Before replaying extents, truncate the inode to its
+ * size. We need to do it now and not after log replay
+ * because before an fsync we can have prealloc extents
+ * added beyond the inode's i_size. If we did it after,
+ * through orphan cleanup for example, we would drop
+ * those prealloc extents just after replaying them.
+ */
+ if (S_ISREG(mode)) {
+ struct inode *inode;
+ u64 from;
+
+ inode = read_one_inode(root, key.objectid);
+ if (!inode) {
+ ret = -EIO;
+ break;
+ }
+ from = ALIGN(i_size_read(inode),
+ root->fs_info->sectorsize);
+ ret = btrfs_drop_extents(wc->trans, root, inode,
+ from, (u64)-1, 1);
+ if (!ret) {
+ /* Update the inode's nbytes. */
+ ret = btrfs_update_inode(wc->trans,
+ root, inode);
+ }
+ iput(inode);
+ if (ret)
+ break;
+ }
+
+ ret = link_to_fixup_dir(wc->trans, root,
+ path, key.objectid);
+ if (ret)
+ break;
+ }
+
+ if (wc->ignore_cur_inode)
+ continue;
+
+ if (key.type == BTRFS_DIR_INDEX_KEY &&
+ wc->stage == LOG_WALK_REPLAY_DIR_INDEX) {
+ ret = replay_one_dir_item(wc->trans, root, path,
+ eb, i, &key);
+ if (ret)
+ break;
+ }
+
+ if (wc->stage < LOG_WALK_REPLAY_ALL)
+ continue;
+
+ /* these keys are simply copied */
+ if (key.type == BTRFS_XATTR_ITEM_KEY) {
+ ret = overwrite_item(wc->trans, root, path,
+ eb, i, &key);
+ if (ret)
+ break;
+ } else if (key.type == BTRFS_INODE_REF_KEY ||
+ key.type == BTRFS_INODE_EXTREF_KEY) {
+ ret = add_inode_ref(wc->trans, root, log, path,
+ eb, i, &key);
+ if (ret && ret != -ENOENT)
+ break;
+ ret = 0;
+ } else if (key.type == BTRFS_EXTENT_DATA_KEY) {
+ ret = replay_one_extent(wc->trans, root, path,
+ eb, i, &key);
+ if (ret)
+ break;
+ } else if (key.type == BTRFS_DIR_ITEM_KEY) {
+ ret = replay_one_dir_item(wc->trans, root, path,
+ eb, i, &key);
+ if (ret)
+ break;
+ }
+ }
+ btrfs_free_path(path);
+ return ret;
+}
+
+static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, int *level,
+ struct walk_control *wc)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ u64 root_owner;
+ u64 bytenr;
+ u64 ptr_gen;
+ struct extent_buffer *next;
+ struct extent_buffer *cur;
+ struct extent_buffer *parent;
+ u32 blocksize;
+ int ret = 0;
+
+ WARN_ON(*level < 0);
+ WARN_ON(*level >= BTRFS_MAX_LEVEL);
+
+ while (*level > 0) {
+ struct btrfs_key first_key;
+
+ WARN_ON(*level < 0);
+ WARN_ON(*level >= BTRFS_MAX_LEVEL);
+ cur = path->nodes[*level];
+
+ WARN_ON(btrfs_header_level(cur) != *level);
+
+ if (path->slots[*level] >=
+ btrfs_header_nritems(cur))
+ break;
+
+ bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
+ ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
+ btrfs_node_key_to_cpu(cur, &first_key, path->slots[*level]);
+ blocksize = fs_info->nodesize;
+
+ parent = path->nodes[*level];
+ root_owner = btrfs_header_owner(parent);
+
+ next = btrfs_find_create_tree_block(fs_info, bytenr);
+ if (IS_ERR(next))
+ return PTR_ERR(next);
+
+ if (*level == 1) {
+ ret = wc->process_func(root, next, wc, ptr_gen,
+ *level - 1);
+ if (ret) {
+ free_extent_buffer(next);
+ return ret;
+ }
+
+ path->slots[*level]++;
+ if (wc->free) {
+ ret = btrfs_read_buffer(next, ptr_gen,
+ *level - 1, &first_key);
+ if (ret) {
+ free_extent_buffer(next);
+ return ret;
+ }
+
+ if (trans) {
+ btrfs_tree_lock(next);
+ btrfs_set_lock_blocking(next);
+ clean_tree_block(fs_info, next);
+ btrfs_wait_tree_block_writeback(next);
+ btrfs_tree_unlock(next);
+ } else {
+ if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags))
+ clear_extent_buffer_dirty(next);
+ }
+
+ WARN_ON(root_owner !=
+ BTRFS_TREE_LOG_OBJECTID);
+ ret = btrfs_free_and_pin_reserved_extent(
+ fs_info, bytenr,
+ blocksize);
+ if (ret) {
+ free_extent_buffer(next);
+ return ret;
+ }
+ }
+ free_extent_buffer(next);
+ continue;
+ }
+ ret = btrfs_read_buffer(next, ptr_gen, *level - 1, &first_key);
+ if (ret) {
+ free_extent_buffer(next);
+ return ret;
+ }
+
+ WARN_ON(*level <= 0);
+ if (path->nodes[*level-1])
+ free_extent_buffer(path->nodes[*level-1]);
+ path->nodes[*level-1] = next;
+ *level = btrfs_header_level(next);
+ path->slots[*level] = 0;
+ cond_resched();
+ }
+ WARN_ON(*level < 0);
+ WARN_ON(*level >= BTRFS_MAX_LEVEL);
+
+ path->slots[*level] = btrfs_header_nritems(path->nodes[*level]);
+
+ cond_resched();
+ return 0;
+}
+
+static noinline int walk_up_log_tree(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, int *level,
+ struct walk_control *wc)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ u64 root_owner;
+ int i;
+ int slot;
+ int ret;
+
+ for (i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
+ slot = path->slots[i];
+ if (slot + 1 < btrfs_header_nritems(path->nodes[i])) {
+ path->slots[i]++;
+ *level = i;
+ WARN_ON(*level == 0);
+ return 0;
+ } else {
+ struct extent_buffer *parent;
+ if (path->nodes[*level] == root->node)
+ parent = path->nodes[*level];
+ else
+ parent = path->nodes[*level + 1];
+
+ root_owner = btrfs_header_owner(parent);
+ ret = wc->process_func(root, path->nodes[*level], wc,
+ btrfs_header_generation(path->nodes[*level]),
+ *level);
+ if (ret)
+ return ret;
+
+ if (wc->free) {
+ struct extent_buffer *next;
+
+ next = path->nodes[*level];
+
+ if (trans) {
+ btrfs_tree_lock(next);
+ btrfs_set_lock_blocking(next);
+ clean_tree_block(fs_info, next);
+ btrfs_wait_tree_block_writeback(next);
+ btrfs_tree_unlock(next);
+ } else {
+ if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags))
+ clear_extent_buffer_dirty(next);
+ }
+
+ WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID);
+ ret = btrfs_free_and_pin_reserved_extent(
+ fs_info,
+ path->nodes[*level]->start,
+ path->nodes[*level]->len);
+ if (ret)
+ return ret;
+ }
+ free_extent_buffer(path->nodes[*level]);
+ path->nodes[*level] = NULL;
+ *level = i + 1;
+ }
+ }
+ return 1;
+}
+
+/*
+ * drop the reference count on the tree rooted at 'snap'. This traverses
+ * the tree freeing any blocks that have a ref count of zero after being
+ * decremented.
+ */
+static int walk_log_tree(struct btrfs_trans_handle *trans,
+ struct btrfs_root *log, struct walk_control *wc)
+{
+ struct btrfs_fs_info *fs_info = log->fs_info;
+ int ret = 0;
+ int wret;
+ int level;
+ struct btrfs_path *path;
+ int orig_level;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ level = btrfs_header_level(log->node);
+ orig_level = level;
+ path->nodes[level] = log->node;
+ extent_buffer_get(log->node);
+ path->slots[level] = 0;
+
+ while (1) {
+ wret = walk_down_log_tree(trans, log, path, &level, wc);
+ if (wret > 0)
+ break;
+ if (wret < 0) {
+ ret = wret;
+ goto out;
+ }
+
+ wret = walk_up_log_tree(trans, log, path, &level, wc);
+ if (wret > 0)
+ break;
+ if (wret < 0) {
+ ret = wret;
+ goto out;
+ }
+ }
+
+ /* was the root node processed? if not, catch it here */
+ if (path->nodes[orig_level]) {
+ ret = wc->process_func(log, path->nodes[orig_level], wc,
+ btrfs_header_generation(path->nodes[orig_level]),
+ orig_level);
+ if (ret)
+ goto out;
+ if (wc->free) {
+ struct extent_buffer *next;
+
+ next = path->nodes[orig_level];
+
+ if (trans) {
+ btrfs_tree_lock(next);
+ btrfs_set_lock_blocking(next);
+ clean_tree_block(fs_info, next);
+ btrfs_wait_tree_block_writeback(next);
+ btrfs_tree_unlock(next);
+ } else {
+ if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags))
+ clear_extent_buffer_dirty(next);
+ }
+
+ WARN_ON(log->root_key.objectid !=
+ BTRFS_TREE_LOG_OBJECTID);
+ ret = btrfs_free_and_pin_reserved_extent(fs_info,
+ next->start, next->len);
+ if (ret)
+ goto out;
+ }
+ }
+
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * helper function to update the item for a given subvolumes log root
+ * in the tree of log roots
+ */
+static int update_log_root(struct btrfs_trans_handle *trans,
+ struct btrfs_root *log)
+{
+ struct btrfs_fs_info *fs_info = log->fs_info;
+ int ret;
+
+ 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);
+ } else {
+ ret = btrfs_update_root(trans, fs_info->log_root_tree,
+ &log->root_key, &log->root_item);
+ }
+ return ret;
+}
+
+static void wait_log_commit(struct btrfs_root *root, int transid)
+{
+ DEFINE_WAIT(wait);
+ int index = transid % 2;
+
+ /*
+ * we only allow two pending log transactions at a time,
+ * so we know that if ours is more than 2 older than the
+ * current transaction, we're done
+ */
+ for (;;) {
+ prepare_to_wait(&root->log_commit_wait[index],
+ &wait, TASK_UNINTERRUPTIBLE);
+
+ if (!(root->log_transid_committed < transid &&
+ atomic_read(&root->log_commit[index])))
+ break;
+
+ mutex_unlock(&root->log_mutex);
+ schedule();
+ mutex_lock(&root->log_mutex);
+ }
+ finish_wait(&root->log_commit_wait[index], &wait);
+}
+
+static void wait_for_writer(struct btrfs_root *root)
+{
+ DEFINE_WAIT(wait);
+
+ for (;;) {
+ prepare_to_wait(&root->log_writer_wait, &wait,
+ TASK_UNINTERRUPTIBLE);
+ if (!atomic_read(&root->log_writers))
+ break;
+
+ mutex_unlock(&root->log_mutex);
+ schedule();
+ mutex_lock(&root->log_mutex);
+ }
+ finish_wait(&root->log_writer_wait, &wait);
+}
+
+static inline void btrfs_remove_log_ctx(struct btrfs_root *root,
+ struct btrfs_log_ctx *ctx)
+{
+ if (!ctx)
+ return;
+
+ mutex_lock(&root->log_mutex);
+ list_del_init(&ctx->list);
+ mutex_unlock(&root->log_mutex);
+}
+
+/*
+ * Invoked in log mutex context, or be sure there is no other task which
+ * can access the list.
+ */
+static inline void btrfs_remove_all_log_ctxs(struct btrfs_root *root,
+ int index, int error)
+{
+ struct btrfs_log_ctx *ctx;
+ struct btrfs_log_ctx *safe;
+
+ list_for_each_entry_safe(ctx, safe, &root->log_ctxs[index], list) {
+ list_del_init(&ctx->list);
+ ctx->log_ret = error;
+ }
+
+ INIT_LIST_HEAD(&root->log_ctxs[index]);
+}
+
+/*
+ * btrfs_sync_log does sends a given tree log down to the disk and
+ * updates the super blocks to record it. When this call is done,
+ * you know that any inodes previously logged are safely on disk only
+ * if it returns 0.
+ *
+ * Any other return value means you need to call btrfs_commit_transaction.
+ * Some of the edge cases for fsyncing directories that have had unlinks
+ * or renames done in the past mean that sometimes the only safe
+ * fsync is to commit the whole FS. When btrfs_sync_log returns -EAGAIN,
+ * that has happened.
+ */
+int btrfs_sync_log(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct btrfs_log_ctx *ctx)
+{
+ int index1;
+ int index2;
+ int mark;
+ int ret;
+ 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;
+ int log_transid = 0;
+ struct btrfs_log_ctx root_log_ctx;
+ struct blk_plug plug;
+
+ mutex_lock(&root->log_mutex);
+ log_transid = ctx->log_transid;
+ if (root->log_transid_committed >= log_transid) {
+ mutex_unlock(&root->log_mutex);
+ return ctx->log_ret;
+ }
+
+ index1 = log_transid % 2;
+ if (atomic_read(&root->log_commit[index1])) {
+ wait_log_commit(root, log_transid);
+ mutex_unlock(&root->log_mutex);
+ return ctx->log_ret;
+ }
+ ASSERT(log_transid == root->log_transid);
+ atomic_set(&root->log_commit[index1], 1);
+
+ /* wait for previous tree log sync to complete */
+ if (atomic_read(&root->log_commit[(index1 + 1) % 2]))
+ wait_log_commit(root, log_transid - 1);
+
+ while (1) {
+ int batch = atomic_read(&root->log_batch);
+ /* when we're on an ssd, just kick the log commit out */
+ if (!btrfs_test_opt(fs_info, SSD) &&
+ test_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state)) {
+ mutex_unlock(&root->log_mutex);
+ schedule_timeout_uninterruptible(1);
+ mutex_lock(&root->log_mutex);
+ }
+ wait_for_writer(root);
+ if (batch == atomic_read(&root->log_batch))
+ break;
+ }
+
+ /* bail out if we need to do a full commit */
+ if (btrfs_need_log_full_commit(fs_info, trans)) {
+ ret = -EAGAIN;
+ mutex_unlock(&root->log_mutex);
+ goto out;
+ }
+
+ if (log_transid % 2 == 0)
+ mark = EXTENT_DIRTY;
+ else
+ mark = EXTENT_NEW;
+
+ /* we start IO on all the marked extents here, but we don't actually
+ * wait for them until later.
+ */
+ blk_start_plug(&plug);
+ ret = btrfs_write_marked_extents(fs_info, &log->dirty_log_pages, mark);
+ if (ret) {
+ blk_finish_plug(&plug);
+ btrfs_abort_transaction(trans, ret);
+ btrfs_set_log_full_commit(fs_info, trans);
+ mutex_unlock(&root->log_mutex);
+ goto out;
+ }
+
+ btrfs_set_root_node(&log->root_item, log->node);
+
+ root->log_transid++;
+ log->log_transid = root->log_transid;
+ root->log_start_pid = 0;
+ /*
+ * IO has been started, blocks of the log tree have WRITTEN flag set
+ * in their headers. new modifications of the log will be written to
+ * new positions. so it's safe to allow log writers to go in.
+ */
+ mutex_unlock(&root->log_mutex);
+
+ btrfs_init_log_ctx(&root_log_ctx, NULL);
+
+ mutex_lock(&log_root_tree->log_mutex);
+ atomic_inc(&log_root_tree->log_batch);
+ atomic_inc(&log_root_tree->log_writers);
+
+ index2 = log_root_tree->log_transid % 2;
+ list_add_tail(&root_log_ctx.list, &log_root_tree->log_ctxs[index2]);
+ root_log_ctx.log_transid = log_root_tree->log_transid;
+
+ mutex_unlock(&log_root_tree->log_mutex);
+
+ ret = update_log_root(trans, log);
+
+ mutex_lock(&log_root_tree->log_mutex);
+ 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);
+ }
+
+ if (ret) {
+ if (!list_empty(&root_log_ctx.list))
+ list_del_init(&root_log_ctx.list);
+
+ blk_finish_plug(&plug);
+ btrfs_set_log_full_commit(fs_info, trans);
+
+ if (ret != -ENOSPC) {
+ btrfs_abort_transaction(trans, ret);
+ mutex_unlock(&log_root_tree->log_mutex);
+ goto out;
+ }
+ btrfs_wait_tree_log_extents(log, mark);
+ mutex_unlock(&log_root_tree->log_mutex);
+ ret = -EAGAIN;
+ goto out;
+ }
+
+ if (log_root_tree->log_transid_committed >= root_log_ctx.log_transid) {
+ blk_finish_plug(&plug);
+ list_del_init(&root_log_ctx.list);
+ mutex_unlock(&log_root_tree->log_mutex);
+ ret = root_log_ctx.log_ret;
+ goto out;
+ }
+
+ index2 = root_log_ctx.log_transid % 2;
+ if (atomic_read(&log_root_tree->log_commit[index2])) {
+ blk_finish_plug(&plug);
+ ret = btrfs_wait_tree_log_extents(log, mark);
+ wait_log_commit(log_root_tree,
+ root_log_ctx.log_transid);
+ mutex_unlock(&log_root_tree->log_mutex);
+ if (!ret)
+ ret = root_log_ctx.log_ret;
+ goto out;
+ }
+ ASSERT(root_log_ctx.log_transid == log_root_tree->log_transid);
+ atomic_set(&log_root_tree->log_commit[index2], 1);
+
+ if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2])) {
+ wait_log_commit(log_root_tree,
+ root_log_ctx.log_transid - 1);
+ }
+
+ wait_for_writer(log_root_tree);
+
+ /*
+ * 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)) {
+ blk_finish_plug(&plug);
+ btrfs_wait_tree_log_extents(log, mark);
+ mutex_unlock(&log_root_tree->log_mutex);
+ ret = -EAGAIN;
+ goto out_wake_log_root;
+ }
+
+ ret = btrfs_write_marked_extents(fs_info,
+ &log_root_tree->dirty_log_pages,
+ EXTENT_DIRTY | EXTENT_NEW);
+ blk_finish_plug(&plug);
+ if (ret) {
+ btrfs_set_log_full_commit(fs_info, trans);
+ btrfs_abort_transaction(trans, ret);
+ mutex_unlock(&log_root_tree->log_mutex);
+ goto out_wake_log_root;
+ }
+ ret = btrfs_wait_tree_log_extents(log, mark);
+ if (!ret)
+ ret = btrfs_wait_tree_log_extents(log_root_tree,
+ EXTENT_NEW | EXTENT_DIRTY);
+ if (ret) {
+ btrfs_set_log_full_commit(fs_info, trans);
+ mutex_unlock(&log_root_tree->log_mutex);
+ goto out_wake_log_root;
+ }
+
+ btrfs_set_super_log_root(fs_info->super_for_commit,
+ log_root_tree->node->start);
+ btrfs_set_super_log_root_level(fs_info->super_for_commit,
+ btrfs_header_level(log_root_tree->node));
+
+ log_root_tree->log_transid++;
+ mutex_unlock(&log_root_tree->log_mutex);
+
+ /*
+ * nobody else is going to jump in and write the 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
+ * in and cause problems either.
+ */
+ ret = write_all_supers(fs_info, 1);
+ if (ret) {
+ btrfs_set_log_full_commit(fs_info, trans);
+ btrfs_abort_transaction(trans, ret);
+ goto out_wake_log_root;
+ }
+
+ mutex_lock(&root->log_mutex);
+ if (root->last_log_commit < log_transid)
+ root->last_log_commit = log_transid;
+ mutex_unlock(&root->log_mutex);
+
+out_wake_log_root:
+ mutex_lock(&log_root_tree->log_mutex);
+ btrfs_remove_all_log_ctxs(log_root_tree, index2, ret);
+
+ log_root_tree->log_transid_committed++;
+ atomic_set(&log_root_tree->log_commit[index2], 0);
+ mutex_unlock(&log_root_tree->log_mutex);
+
+ /*
+ * The barrier before waitqueue_active (in cond_wake_up) is needed so
+ * all the updates above are seen by the woken threads. It might not be
+ * necessary, but proving that seems to be hard.
+ */
+ cond_wake_up(&log_root_tree->log_commit_wait[index2]);
+out:
+ mutex_lock(&root->log_mutex);
+ btrfs_remove_all_log_ctxs(root, index1, ret);
+ root->log_transid_committed++;
+ atomic_set(&root->log_commit[index1], 0);
+ mutex_unlock(&root->log_mutex);
+
+ /*
+ * The barrier before waitqueue_active (in cond_wake_up) is needed so
+ * all the updates above are seen by the woken threads. It might not be
+ * necessary, but proving that seems to be hard.
+ */
+ cond_wake_up(&root->log_commit_wait[index1]);
+ return ret;
+}
+
+static void free_log_tree(struct btrfs_trans_handle *trans,
+ struct btrfs_root *log)
+{
+ int ret;
+ u64 start;
+ u64 end;
+ struct walk_control wc = {
+ .free = 1,
+ .process_func = process_one_buffer
+ };
+
+ ret = walk_log_tree(trans, log, &wc);
+ if (ret) {
+ if (trans)
+ btrfs_abort_transaction(trans, ret);
+ else
+ 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);
+ }
+
+ free_extent_buffer(log->node);
+ kfree(log);
+}
+
+/*
+ * free all the extents used by the tree log. This should be called
+ * at commit time of the full transaction
+ */
+int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
+{
+ if (root->log_root) {
+ free_log_tree(trans, root->log_root);
+ root->log_root = NULL;
+ }
+ return 0;
+}
+
+int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
+ struct btrfs_fs_info *fs_info)
+{
+ if (fs_info->log_root_tree) {
+ free_log_tree(trans, fs_info->log_root_tree);
+ fs_info->log_root_tree = NULL;
+ }
+ return 0;
+}
+
+/*
+ * If both a file and directory are logged, and unlinks or renames are
+ * mixed in, we have a few interesting corners:
+ *
+ * create file X in dir Y
+ * link file X to X.link in dir Y
+ * fsync file X
+ * unlink file X but leave X.link
+ * fsync dir Y
+ *
+ * After a crash we would expect only X.link to exist. But file X
+ * didn't get fsync'd again so the log has back refs for X and X.link.
+ *
+ * We solve this by removing directory entries and inode backrefs from the
+ * log when a file that was logged in the current transaction is
+ * unlinked. Any later fsync will include the updated log entries, and
+ * we'll be able to reconstruct the proper directory items from backrefs.
+ *
+ * This optimizations allows us to avoid relogging the entire inode
+ * or the entire directory.
+ */
+int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ const char *name, int name_len,
+ struct btrfs_inode *dir, u64 index)
+{
+ struct btrfs_root *log;
+ struct btrfs_dir_item *di;
+ struct btrfs_path *path;
+ int ret;
+ int err = 0;
+ int bytes_del = 0;
+ u64 dir_ino = btrfs_ino(dir);
+
+ if (dir->logged_trans < trans->transid)
+ return 0;
+
+ ret = join_running_log_trans(root);
+ if (ret)
+ return 0;
+
+ mutex_lock(&dir->log_mutex);
+
+ log = root->log_root;
+ path = btrfs_alloc_path();
+ if (!path) {
+ err = -ENOMEM;
+ goto out_unlock;
+ }
+
+ di = btrfs_lookup_dir_item(trans, log, path, dir_ino,
+ name, name_len, -1);
+ if (IS_ERR(di)) {
+ err = PTR_ERR(di);
+ goto fail;
+ }
+ if (di) {
+ ret = btrfs_delete_one_dir_name(trans, log, path, di);
+ bytes_del += name_len;
+ if (ret) {
+ err = ret;
+ goto fail;
+ }
+ }
+ btrfs_release_path(path);
+ di = btrfs_lookup_dir_index_item(trans, log, path, dir_ino,
+ index, name, name_len, -1);
+ if (IS_ERR(di)) {
+ err = PTR_ERR(di);
+ goto fail;
+ }
+ if (di) {
+ ret = btrfs_delete_one_dir_name(trans, log, path, di);
+ bytes_del += name_len;
+ if (ret) {
+ err = ret;
+ goto fail;
+ }
+ }
+
+ /* update the directory size in the log to reflect the names
+ * we have removed
+ */
+ if (bytes_del) {
+ struct btrfs_key key;
+
+ key.objectid = dir_ino;
+ key.offset = 0;
+ key.type = BTRFS_INODE_ITEM_KEY;
+ btrfs_release_path(path);
+
+ ret = btrfs_search_slot(trans, log, &key, path, 0, 1);
+ if (ret < 0) {
+ err = ret;
+ goto fail;
+ }
+ if (ret == 0) {
+ struct btrfs_inode_item *item;
+ u64 i_size;
+
+ item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_inode_item);
+ i_size = btrfs_inode_size(path->nodes[0], item);
+ if (i_size > bytes_del)
+ i_size -= bytes_del;
+ else
+ i_size = 0;
+ btrfs_set_inode_size(path->nodes[0], item, i_size);
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+ } else
+ ret = 0;
+ btrfs_release_path(path);
+ }
+fail:
+ btrfs_free_path(path);
+out_unlock:
+ mutex_unlock(&dir->log_mutex);
+ if (ret == -ENOSPC) {
+ btrfs_set_log_full_commit(root->fs_info, trans);
+ ret = 0;
+ } else if (ret < 0)
+ btrfs_abort_transaction(trans, ret);
+
+ btrfs_end_log_trans(root);
+
+ return err;
+}
+
+/* see comments for btrfs_del_dir_entries_in_log */
+int btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ 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)
+ return 0;
+
+ ret = join_running_log_trans(root);
+ if (ret)
+ return 0;
+ log = root->log_root;
+ mutex_lock(&inode->log_mutex);
+
+ ret = btrfs_del_inode_ref(trans, log, name, name_len, btrfs_ino(inode),
+ dirid, &index);
+ mutex_unlock(&inode->log_mutex);
+ if (ret == -ENOSPC) {
+ btrfs_set_log_full_commit(fs_info, trans);
+ ret = 0;
+ } else if (ret < 0 && ret != -ENOENT)
+ btrfs_abort_transaction(trans, ret);
+ btrfs_end_log_trans(root);
+
+ return ret;
+}
+
+/*
+ * creates a range item in the log for 'dirid'. first_offset and
+ * last_offset tell us which parts of the key space the log should
+ * be considered authoritative for.
+ */
+static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans,
+ struct btrfs_root *log,
+ struct btrfs_path *path,
+ int key_type, u64 dirid,
+ u64 first_offset, u64 last_offset)
+{
+ int ret;
+ struct btrfs_key key;
+ struct btrfs_dir_log_item *item;
+
+ key.objectid = dirid;
+ key.offset = first_offset;
+ if (key_type == BTRFS_DIR_ITEM_KEY)
+ key.type = BTRFS_DIR_LOG_ITEM_KEY;
+ else
+ key.type = BTRFS_DIR_LOG_INDEX_KEY;
+ ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item));
+ if (ret)
+ return ret;
+
+ item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_dir_log_item);
+ btrfs_set_dir_log_end(path->nodes[0], item, last_offset);
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+ btrfs_release_path(path);
+ return 0;
+}
+
+/*
+ * log all the items included in the current transaction for a given
+ * directory. This also creates the range items in the log tree required
+ * to replay anything deleted before the fsync
+ */
+static noinline int log_dir_items(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct btrfs_inode *inode,
+ struct btrfs_path *path,
+ struct btrfs_path *dst_path, int key_type,
+ struct btrfs_log_ctx *ctx,
+ u64 min_offset, u64 *last_offset_ret)
+{
+ struct btrfs_key min_key;
+ struct btrfs_root *log = root->log_root;
+ struct extent_buffer *src;
+ int err = 0;
+ int ret;
+ int i;
+ int nritems;
+ u64 first_offset = min_offset;
+ u64 last_offset = (u64)-1;
+ u64 ino = btrfs_ino(inode);
+
+ log = root->log_root;
+
+ min_key.objectid = ino;
+ min_key.type = key_type;
+ min_key.offset = min_offset;
+
+ ret = btrfs_search_forward(root, &min_key, path, trans->transid);
+
+ /*
+ * we didn't find anything from this transaction, see if there
+ * is anything at all
+ */
+ if (ret != 0 || min_key.objectid != ino || min_key.type != key_type) {
+ min_key.objectid = ino;
+ min_key.type = key_type;
+ min_key.offset = (u64)-1;
+ btrfs_release_path(path);
+ ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
+ if (ret < 0) {
+ btrfs_release_path(path);
+ return ret;
+ }
+ ret = btrfs_previous_item(root, path, ino, key_type);
+
+ /* if ret == 0 there are items for this type,
+ * create a range to tell us the last key of this type.
+ * otherwise, there are no items in this directory after
+ * *min_offset, and we create a range to indicate that.
+ */
+ if (ret == 0) {
+ struct btrfs_key tmp;
+ btrfs_item_key_to_cpu(path->nodes[0], &tmp,
+ path->slots[0]);
+ if (key_type == tmp.type)
+ first_offset = max(min_offset, tmp.offset) + 1;
+ }
+ goto done;
+ }
+
+ /* go backward to find any previous key */
+ ret = btrfs_previous_item(root, path, ino, key_type);
+ if (ret == 0) {
+ struct btrfs_key tmp;
+ btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
+ if (key_type == tmp.type) {
+ first_offset = tmp.offset;
+ ret = overwrite_item(trans, log, dst_path,
+ path->nodes[0], path->slots[0],
+ &tmp);
+ if (ret) {
+ err = ret;
+ goto done;
+ }
+ }
+ }
+ btrfs_release_path(path);
+
+ /* find the first key from this transaction again */
+ ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
+ if (WARN_ON(ret != 0))
+ goto done;
+
+ /*
+ * we have a block from this transaction, log every item in it
+ * from our directory
+ */
+ while (1) {
+ struct btrfs_key tmp;
+ src = path->nodes[0];
+ nritems = btrfs_header_nritems(src);
+ for (i = path->slots[0]; i < nritems; i++) {
+ struct btrfs_dir_item *di;
+
+ btrfs_item_key_to_cpu(src, &min_key, i);
+
+ if (min_key.objectid != ino || min_key.type != key_type)
+ goto done;
+ ret = overwrite_item(trans, log, dst_path, src, i,
+ &min_key);
+ if (ret) {
+ err = ret;
+ goto done;
+ }
+
+ /*
+ * We must make sure that when we log a directory entry,
+ * the corresponding inode, after log replay, has a
+ * matching link count. For example:
+ *
+ * touch foo
+ * mkdir mydir
+ * sync
+ * ln foo mydir/bar
+ * xfs_io -c "fsync" mydir
+ * <crash>
+ * <mount fs and log replay>
+ *
+ * Would result in a fsync log that when replayed, our
+ * file inode would have a link count of 1, but we get
+ * two directory entries pointing to the same inode.
+ * After removing one of the names, it would not be
+ * possible to remove the other name, which resulted
+ * always in stale file handle errors, and would not
+ * be possible to rmdir the parent directory, since
+ * its i_size could never decrement to the value
+ * BTRFS_EMPTY_DIR_SIZE, resulting in -ENOTEMPTY errors.
+ */
+ di = btrfs_item_ptr(src, i, struct btrfs_dir_item);
+ btrfs_dir_item_key_to_cpu(src, di, &tmp);
+ if (ctx &&
+ (btrfs_dir_transid(src, di) == trans->transid ||
+ btrfs_dir_type(src, di) == BTRFS_FT_DIR) &&
+ tmp.type != BTRFS_ROOT_ITEM_KEY)
+ ctx->log_new_dentries = true;
+ }
+ path->slots[0] = nritems;
+
+ /*
+ * look ahead to the next item and see if it is also
+ * from this directory and from this transaction
+ */
+ ret = btrfs_next_leaf(root, path);
+ if (ret) {
+ if (ret == 1)
+ last_offset = (u64)-1;
+ else
+ err = ret;
+ goto done;
+ }
+ btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
+ if (tmp.objectid != ino || tmp.type != key_type) {
+ last_offset = (u64)-1;
+ goto done;
+ }
+ if (btrfs_header_generation(path->nodes[0]) != trans->transid) {
+ ret = overwrite_item(trans, log, dst_path,
+ path->nodes[0], path->slots[0],
+ &tmp);
+ if (ret)
+ err = ret;
+ else
+ last_offset = tmp.offset;
+ goto done;
+ }
+ }
+done:
+ btrfs_release_path(path);
+ btrfs_release_path(dst_path);
+
+ if (err == 0) {
+ *last_offset_ret = last_offset;
+ /*
+ * insert the log range keys to indicate where the log
+ * is valid
+ */
+ ret = insert_dir_log_key(trans, log, path, key_type,
+ ino, first_offset, last_offset);
+ if (ret)
+ err = ret;
+ }
+ return err;
+}
+
+/*
+ * logging directories is very similar to logging inodes, We find all the items
+ * from the current transaction and write them to the log.
+ *
+ * The recovery code scans the directory in the subvolume, and if it finds a
+ * key in the range logged that is not present in the log tree, then it means
+ * that dir entry was unlinked during the transaction.
+ *
+ * In order for that scan to work, we must include one key smaller than
+ * the smallest logged by this transaction and one key larger than the largest
+ * key logged by this transaction.
+ */
+static noinline int log_directory_changes(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct btrfs_inode *inode,
+ struct btrfs_path *path,
+ struct btrfs_path *dst_path,
+ struct btrfs_log_ctx *ctx)
+{
+ u64 min_key;
+ u64 max_key;
+ int ret;
+ int key_type = BTRFS_DIR_ITEM_KEY;
+
+again:
+ min_key = 0;
+ max_key = 0;
+ while (1) {
+ ret = log_dir_items(trans, root, inode, path, dst_path, key_type,
+ ctx, min_key, &max_key);
+ if (ret)
+ return ret;
+ if (max_key == (u64)-1)
+ break;
+ min_key = max_key + 1;
+ }
+
+ if (key_type == BTRFS_DIR_ITEM_KEY) {
+ key_type = BTRFS_DIR_INDEX_KEY;
+ goto again;
+ }
+ return 0;
+}
+
+/*
+ * a helper function to drop items from the log before we relog an
+ * inode. max_key_type indicates the highest item type to remove.
+ * This cannot be run for file data extents because it does not
+ * free the extents they point to.
+ */
+static int drop_objectid_items(struct btrfs_trans_handle *trans,
+ struct btrfs_root *log,
+ struct btrfs_path *path,
+ u64 objectid, int max_key_type)
+{
+ int ret;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ int start_slot;
+
+ key.objectid = objectid;
+ key.type = max_key_type;
+ key.offset = (u64)-1;
+
+ while (1) {
+ ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
+ BUG_ON(ret == 0); /* Logic error */
+ if (ret < 0)
+ break;
+
+ if (path->slots[0] == 0)
+ break;
+
+ path->slots[0]--;
+ btrfs_item_key_to_cpu(path->nodes[0], &found_key,
+ path->slots[0]);
+
+ if (found_key.objectid != objectid)
+ break;
+
+ found_key.offset = 0;
+ found_key.type = 0;
+ ret = btrfs_bin_search(path->nodes[0], &found_key, 0,
+ &start_slot);
+
+ ret = btrfs_del_items(trans, log, path, start_slot,
+ path->slots[0] - start_slot + 1);
+ /*
+ * If start slot isn't 0 then we don't need to re-search, we've
+ * found the last guy with the objectid in this tree.
+ */
+ if (ret || start_slot != 0)
+ break;
+ btrfs_release_path(path);
+ }
+ btrfs_release_path(path);
+ if (ret > 0)
+ ret = 0;
+ return ret;
+}
+
+static void fill_inode_item(struct btrfs_trans_handle *trans,
+ struct extent_buffer *leaf,
+ struct btrfs_inode_item *item,
+ struct inode *inode, int log_inode_only,
+ u64 logged_isize)
+{
+ struct btrfs_map_token token;
+
+ btrfs_init_map_token(&token);
+
+ if (log_inode_only) {
+ /* set the generation to zero so the recover code
+ * can tell the difference between an logging
+ * just to say 'this inode exists' and a logging
+ * to say 'update this inode with these values'
+ */
+ btrfs_set_token_inode_generation(leaf, item, 0, &token);
+ btrfs_set_token_inode_size(leaf, item, logged_isize, &token);
+ } else {
+ btrfs_set_token_inode_generation(leaf, item,
+ BTRFS_I(inode)->generation,
+ &token);
+ btrfs_set_token_inode_size(leaf, item, inode->i_size, &token);
+ }
+
+ btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
+ btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
+ btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
+ btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
+
+ btrfs_set_token_timespec_sec(leaf, &item->atime,
+ inode->i_atime.tv_sec, &token);
+ btrfs_set_token_timespec_nsec(leaf, &item->atime,
+ inode->i_atime.tv_nsec, &token);
+
+ btrfs_set_token_timespec_sec(leaf, &item->mtime,
+ inode->i_mtime.tv_sec, &token);
+ btrfs_set_token_timespec_nsec(leaf, &item->mtime,
+ inode->i_mtime.tv_nsec, &token);
+
+ btrfs_set_token_timespec_sec(leaf, &item->ctime,
+ inode->i_ctime.tv_sec, &token);
+ btrfs_set_token_timespec_nsec(leaf, &item->ctime,
+ inode->i_ctime.tv_nsec, &token);
+
+ btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
+ &token);
+
+ btrfs_set_token_inode_sequence(leaf, item,
+ inode_peek_iversion(inode), &token);
+ btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
+ btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
+ btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
+ btrfs_set_token_inode_block_group(leaf, item, 0, &token);
+}
+
+static int log_inode_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *log, struct btrfs_path *path,
+ struct btrfs_inode *inode)
+{
+ struct btrfs_inode_item *inode_item;
+ int ret;
+
+ ret = btrfs_insert_empty_item(trans, log, path,
+ &inode->location, sizeof(*inode_item));
+ if (ret && ret != -EEXIST)
+ return ret;
+ inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_inode_item);
+ fill_inode_item(trans, path->nodes[0], inode_item, &inode->vfs_inode,
+ 0, 0);
+ btrfs_release_path(path);
+ return 0;
+}
+
+static noinline int copy_items(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct btrfs_path *dst_path,
+ struct btrfs_path *src_path, u64 *last_extent,
+ int start_slot, int nr, int inode_only,
+ u64 logged_isize)
+{
+ struct btrfs_fs_info *fs_info = trans->fs_info;
+ unsigned long src_offset;
+ unsigned long dst_offset;
+ struct btrfs_root *log = inode->root->log_root;
+ struct btrfs_file_extent_item *extent;
+ struct btrfs_inode_item *inode_item;
+ struct extent_buffer *src = src_path->nodes[0];
+ struct btrfs_key first_key, last_key, key;
+ int ret;
+ struct btrfs_key *ins_keys;
+ u32 *ins_sizes;
+ char *ins_data;
+ int i;
+ struct list_head ordered_sums;
+ int skip_csum = inode->flags & BTRFS_INODE_NODATASUM;
+ bool has_extents = false;
+ bool need_find_last_extent = true;
+ bool done = false;
+
+ INIT_LIST_HEAD(&ordered_sums);
+
+ ins_data = kmalloc(nr * sizeof(struct btrfs_key) +
+ nr * sizeof(u32), GFP_NOFS);
+ if (!ins_data)
+ return -ENOMEM;
+
+ first_key.objectid = (u64)-1;
+
+ ins_sizes = (u32 *)ins_data;
+ ins_keys = (struct btrfs_key *)(ins_data + nr * sizeof(u32));
+
+ for (i = 0; i < nr; i++) {
+ ins_sizes[i] = btrfs_item_size_nr(src, i + start_slot);
+ btrfs_item_key_to_cpu(src, ins_keys + i, i + start_slot);
+ }
+ ret = btrfs_insert_empty_items(trans, log, dst_path,
+ ins_keys, ins_sizes, nr);
+ if (ret) {
+ kfree(ins_data);
+ return ret;
+ }
+
+ for (i = 0; i < nr; i++, dst_path->slots[0]++) {
+ dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0],
+ dst_path->slots[0]);
+
+ src_offset = btrfs_item_ptr_offset(src, start_slot + i);
+
+ if (i == nr - 1)
+ last_key = ins_keys[i];
+
+ if (ins_keys[i].type == BTRFS_INODE_ITEM_KEY) {
+ inode_item = btrfs_item_ptr(dst_path->nodes[0],
+ dst_path->slots[0],
+ struct btrfs_inode_item);
+ fill_inode_item(trans, dst_path->nodes[0], inode_item,
+ &inode->vfs_inode,
+ inode_only == LOG_INODE_EXISTS,
+ logged_isize);
+ } else {
+ copy_extent_buffer(dst_path->nodes[0], src, dst_offset,
+ src_offset, ins_sizes[i]);
+ }
+
+ /*
+ * We set need_find_last_extent here in case we know we were
+ * processing other items and then walk into the first extent in
+ * the inode. If we don't hit an extent then nothing changes,
+ * we'll do the last search the next time around.
+ */
+ if (ins_keys[i].type == BTRFS_EXTENT_DATA_KEY) {
+ has_extents = true;
+ if (first_key.objectid == (u64)-1)
+ first_key = ins_keys[i];
+ } else {
+ need_find_last_extent = false;
+ }
+
+ /* take a reference on file data extents so that truncates
+ * or deletes of this inode don't have to relog the inode
+ * again
+ */
+ if (ins_keys[i].type == BTRFS_EXTENT_DATA_KEY &&
+ !skip_csum) {
+ int found_type;
+ extent = btrfs_item_ptr(src, start_slot + i,
+ struct btrfs_file_extent_item);
+
+ if (btrfs_file_extent_generation(src, extent) < trans->transid)
+ continue;
+
+ found_type = btrfs_file_extent_type(src, extent);
+ if (found_type == BTRFS_FILE_EXTENT_REG) {
+ u64 ds, dl, cs, cl;
+ ds = btrfs_file_extent_disk_bytenr(src,
+ extent);
+ /* ds == 0 is a hole */
+ if (ds == 0)
+ continue;
+
+ dl = btrfs_file_extent_disk_num_bytes(src,
+ extent);
+ cs = btrfs_file_extent_offset(src, extent);
+ cl = btrfs_file_extent_num_bytes(src,
+ extent);
+ if (btrfs_file_extent_compression(src,
+ extent)) {
+ cs = 0;
+ cl = dl;
+ }
+
+ ret = btrfs_lookup_csums_range(
+ fs_info->csum_root,
+ ds + cs, ds + cs + cl - 1,
+ &ordered_sums, 0);
+ if (ret) {
+ btrfs_release_path(dst_path);
+ kfree(ins_data);
+ return ret;
+ }
+ }
+ }
+ }
+
+ btrfs_mark_buffer_dirty(dst_path->nodes[0]);
+ btrfs_release_path(dst_path);
+ kfree(ins_data);
+
+ /*
+ * we have to do this after the loop above to avoid changing the
+ * log tree while trying to change the log tree.
+ */
+ ret = 0;
+ while (!list_empty(&ordered_sums)) {
+ struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next,
+ struct btrfs_ordered_sum,
+ list);
+ if (!ret)
+ ret = btrfs_csum_file_blocks(trans, log, sums);
+ list_del(&sums->list);
+ kfree(sums);
+ }
+
+ if (!has_extents)
+ return ret;
+
+ if (need_find_last_extent && *last_extent == first_key.offset) {
+ /*
+ * We don't have any leafs between our current one and the one
+ * we processed before that can have file extent items for our
+ * inode (and have a generation number smaller than our current
+ * transaction id).
+ */
+ need_find_last_extent = false;
+ }
+
+ /*
+ * Because we use btrfs_search_forward we could skip leaves that were
+ * not modified and then assume *last_extent is valid when it really
+ * isn't. So back up to the previous leaf and read the end of the last
+ * extent before we go and fill in holes.
+ */
+ if (need_find_last_extent) {
+ u64 len;
+
+ ret = btrfs_prev_leaf(inode->root, src_path);
+ if (ret < 0)
+ return ret;
+ if (ret)
+ goto fill_holes;
+ if (src_path->slots[0])
+ src_path->slots[0]--;
+ src = src_path->nodes[0];
+ btrfs_item_key_to_cpu(src, &key, src_path->slots[0]);
+ if (key.objectid != btrfs_ino(inode) ||
+ key.type != BTRFS_EXTENT_DATA_KEY)
+ goto fill_holes;
+ extent = btrfs_item_ptr(src, src_path->slots[0],
+ struct btrfs_file_extent_item);
+ if (btrfs_file_extent_type(src, extent) ==
+ BTRFS_FILE_EXTENT_INLINE) {
+ len = btrfs_file_extent_ram_bytes(src, extent);
+ *last_extent = ALIGN(key.offset + len,
+ fs_info->sectorsize);
+ } else {
+ len = btrfs_file_extent_num_bytes(src, extent);
+ *last_extent = key.offset + len;
+ }
+ }
+fill_holes:
+ /* So we did prev_leaf, now we need to move to the next leaf, but a few
+ * things could have happened
+ *
+ * 1) A merge could have happened, so we could currently be on a leaf
+ * that holds what we were copying in the first place.
+ * 2) A split could have happened, and now not all of the items we want
+ * are on the same leaf.
+ *
+ * So we need to adjust how we search for holes, we need to drop the
+ * path and re-search for the first extent key we found, and then walk
+ * forward until we hit the last one we copied.
+ */
+ if (need_find_last_extent) {
+ /* btrfs_prev_leaf could return 1 without releasing the path */
+ btrfs_release_path(src_path);
+ ret = btrfs_search_slot(NULL, inode->root, &first_key,
+ src_path, 0, 0);
+ if (ret < 0)
+ return ret;
+ ASSERT(ret == 0);
+ src = src_path->nodes[0];
+ i = src_path->slots[0];
+ } else {
+ i = start_slot;
+ }
+
+ /*
+ * Ok so here we need to go through and fill in any holes we may have
+ * to make sure that holes are punched for those areas in case they had
+ * extents previously.
+ */
+ while (!done) {
+ u64 offset, len;
+ u64 extent_end;
+
+ if (i >= btrfs_header_nritems(src_path->nodes[0])) {
+ ret = btrfs_next_leaf(inode->root, src_path);
+ if (ret < 0)
+ return ret;
+ ASSERT(ret == 0);
+ src = src_path->nodes[0];
+ i = 0;
+ need_find_last_extent = true;
+ }
+
+ btrfs_item_key_to_cpu(src, &key, i);
+ if (!btrfs_comp_cpu_keys(&key, &last_key))
+ done = true;
+ if (key.objectid != btrfs_ino(inode) ||
+ key.type != BTRFS_EXTENT_DATA_KEY) {
+ i++;
+ continue;
+ }
+ extent = btrfs_item_ptr(src, i, struct btrfs_file_extent_item);
+ if (btrfs_file_extent_type(src, extent) ==
+ BTRFS_FILE_EXTENT_INLINE) {
+ len = btrfs_file_extent_ram_bytes(src, extent);
+ extent_end = ALIGN(key.offset + len,
+ fs_info->sectorsize);
+ } else {
+ len = btrfs_file_extent_num_bytes(src, extent);
+ extent_end = key.offset + len;
+ }
+ i++;
+
+ if (*last_extent == key.offset) {
+ *last_extent = extent_end;
+ continue;
+ }
+ offset = *last_extent;
+ len = key.offset - *last_extent;
+ ret = btrfs_insert_file_extent(trans, log, btrfs_ino(inode),
+ offset, 0, 0, len, 0, len, 0, 0, 0);
+ if (ret)
+ break;
+ *last_extent = extent_end;
+ }
+
+ /*
+ * Check if there is a hole between the last extent found in our leaf
+ * and the first extent in the next leaf. If there is one, we need to
+ * log an explicit hole so that at replay time we can punch the hole.
+ */
+ if (ret == 0 &&
+ key.objectid == btrfs_ino(inode) &&
+ key.type == BTRFS_EXTENT_DATA_KEY &&
+ i == btrfs_header_nritems(src_path->nodes[0])) {
+ ret = btrfs_next_leaf(inode->root, src_path);
+ need_find_last_extent = true;
+ if (ret > 0) {
+ ret = 0;
+ } else if (ret == 0) {
+ btrfs_item_key_to_cpu(src_path->nodes[0], &key,
+ src_path->slots[0]);
+ if (key.objectid == btrfs_ino(inode) &&
+ key.type == BTRFS_EXTENT_DATA_KEY &&
+ *last_extent < key.offset) {
+ const u64 len = key.offset - *last_extent;
+
+ ret = btrfs_insert_file_extent(trans, log,
+ btrfs_ino(inode),
+ *last_extent, 0,
+ 0, len, 0, len,
+ 0, 0, 0);
+ }
+ }
+ }
+ /*
+ * Need to let the callers know we dropped the path so they should
+ * re-search.
+ */
+ if (!ret && need_find_last_extent)
+ ret = 1;
+ return ret;
+}
+
+static int extent_cmp(void *priv, struct list_head *a, struct list_head *b)
+{
+ struct extent_map *em1, *em2;
+
+ em1 = list_entry(a, struct extent_map, list);
+ em2 = list_entry(b, struct extent_map, list);
+
+ if (em1->start < em2->start)
+ return -1;
+ else if (em1->start > em2->start)
+ return 1;
+ return 0;
+}
+
+static int log_extent_csums(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct btrfs_root *log_root,
+ const struct extent_map *em)
+{
+ u64 csum_offset;
+ u64 csum_len;
+ LIST_HEAD(ordered_sums);
+ int ret = 0;
+
+ if (inode->flags & BTRFS_INODE_NODATASUM ||
+ test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
+ em->block_start == EXTENT_MAP_HOLE)
+ return 0;
+
+ /* If we're compressed we have to save the entire range of csums. */
+ if (em->compress_type) {
+ csum_offset = 0;
+ csum_len = max(em->block_len, em->orig_block_len);
+ } else {
+ csum_offset = em->mod_start - em->start;
+ csum_len = em->mod_len;
+ }
+
+ /* block start is already adjusted for the file extent offset. */
+ ret = btrfs_lookup_csums_range(trans->fs_info->csum_root,
+ em->block_start + csum_offset,
+ em->block_start + csum_offset +
+ csum_len - 1, &ordered_sums, 0);
+ if (ret)
+ return ret;
+
+ while (!list_empty(&ordered_sums)) {
+ struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next,
+ struct btrfs_ordered_sum,
+ list);
+ if (!ret)
+ ret = btrfs_csum_file_blocks(trans, log_root, sums);
+ list_del(&sums->list);
+ kfree(sums);
+ }
+
+ return ret;
+}
+
+static int log_one_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode, struct btrfs_root *root,
+ const struct extent_map *em,
+ struct btrfs_path *path,
+ struct btrfs_log_ctx *ctx)
+{
+ struct btrfs_root *log = root->log_root;
+ struct btrfs_file_extent_item *fi;
+ struct extent_buffer *leaf;
+ struct btrfs_map_token token;
+ struct btrfs_key key;
+ u64 extent_offset = em->start - em->orig_start;
+ u64 block_len;
+ int ret;
+ int extent_inserted = 0;
+
+ ret = log_extent_csums(trans, inode, log, em);
+ 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);
+ if (ret)
+ return ret;
+
+ if (!extent_inserted) {
+ key.objectid = btrfs_ino(inode);
+ key.type = BTRFS_EXTENT_DATA_KEY;
+ key.offset = em->start;
+
+ ret = btrfs_insert_empty_item(trans, log, path, &key,
+ sizeof(*fi));
+ if (ret)
+ return ret;
+ }
+ leaf = path->nodes[0];
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+
+ btrfs_set_token_file_extent_generation(leaf, fi, trans->transid,
+ &token);
+ if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
+ btrfs_set_token_file_extent_type(leaf, fi,
+ BTRFS_FILE_EXTENT_PREALLOC,
+ &token);
+ else
+ btrfs_set_token_file_extent_type(leaf, fi,
+ BTRFS_FILE_EXTENT_REG,
+ &token);
+
+ block_len = max(em->block_len, em->orig_block_len);
+ if (em->compress_type != BTRFS_COMPRESS_NONE) {
+ btrfs_set_token_file_extent_disk_bytenr(leaf, fi,
+ em->block_start,
+ &token);
+ btrfs_set_token_file_extent_disk_num_bytes(leaf, fi, block_len,
+ &token);
+ } else if (em->block_start < EXTENT_MAP_LAST_BYTE) {
+ btrfs_set_token_file_extent_disk_bytenr(leaf, fi,
+ em->block_start -
+ extent_offset, &token);
+ btrfs_set_token_file_extent_disk_num_bytes(leaf, fi, block_len,
+ &token);
+ } else {
+ btrfs_set_token_file_extent_disk_bytenr(leaf, fi, 0, &token);
+ btrfs_set_token_file_extent_disk_num_bytes(leaf, fi, 0,
+ &token);
+ }
+
+ btrfs_set_token_file_extent_offset(leaf, fi, extent_offset, &token);
+ btrfs_set_token_file_extent_num_bytes(leaf, fi, em->len, &token);
+ btrfs_set_token_file_extent_ram_bytes(leaf, fi, em->ram_bytes, &token);
+ btrfs_set_token_file_extent_compression(leaf, fi, em->compress_type,
+ &token);
+ btrfs_set_token_file_extent_encryption(leaf, fi, 0, &token);
+ btrfs_set_token_file_extent_other_encoding(leaf, fi, 0, &token);
+ btrfs_mark_buffer_dirty(leaf);
+
+ btrfs_release_path(path);
+
+ return ret;
+}
+
+/*
+ * Log all prealloc extents beyond the inode's i_size to make sure we do not
+ * lose them after doing a fast fsync and replaying the log. We scan the
+ * subvolume's root instead of iterating the inode's extent map tree because
+ * otherwise we can log incorrect extent items based on extent map conversion.
+ * That can happen due to the fact that extent maps are merged when they
+ * are not in the extent map tree's list of modified extents.
+ */
+static int btrfs_log_prealloc_extents(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct btrfs_path *path)
+{
+ struct btrfs_root *root = inode->root;
+ struct btrfs_key key;
+ const u64 i_size = i_size_read(&inode->vfs_inode);
+ const u64 ino = btrfs_ino(inode);
+ struct btrfs_path *dst_path = NULL;
+ u64 last_extent = (u64)-1;
+ int ins_nr = 0;
+ int start_slot;
+ int ret;
+
+ if (!(inode->flags & BTRFS_INODE_PREALLOC))
+ return 0;
+
+ key.objectid = ino;
+ key.type = BTRFS_EXTENT_DATA_KEY;
+ key.offset = i_size;
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+
+ while (true) {
+ struct extent_buffer *leaf = path->nodes[0];
+ int slot = path->slots[0];
+
+ if (slot >= btrfs_header_nritems(leaf)) {
+ if (ins_nr > 0) {
+ ret = copy_items(trans, inode, dst_path, path,
+ &last_extent, start_slot,
+ ins_nr, 1, 0);
+ if (ret < 0)
+ goto out;
+ ins_nr = 0;
+ }
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) {
+ ret = 0;
+ break;
+ }
+ continue;
+ }
+
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+ if (key.objectid > ino)
+ break;
+ if (WARN_ON_ONCE(key.objectid < ino) ||
+ key.type < BTRFS_EXTENT_DATA_KEY ||
+ key.offset < i_size) {
+ path->slots[0]++;
+ continue;
+ }
+ if (last_extent == (u64)-1) {
+ last_extent = key.offset;
+ /*
+ * Avoid logging extent items logged in past fsync calls
+ * and leading to duplicate keys in the log tree.
+ */
+ do {
+ ret = btrfs_truncate_inode_items(trans,
+ root->log_root,
+ &inode->vfs_inode,
+ i_size,
+ BTRFS_EXTENT_DATA_KEY);
+ } while (ret == -EAGAIN);
+ if (ret)
+ goto out;
+ }
+ if (ins_nr == 0)
+ start_slot = slot;
+ ins_nr++;
+ path->slots[0]++;
+ if (!dst_path) {
+ dst_path = btrfs_alloc_path();
+ if (!dst_path) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ }
+ }
+ if (ins_nr > 0) {
+ ret = copy_items(trans, inode, dst_path, path, &last_extent,
+ start_slot, ins_nr, 1, 0);
+ if (ret > 0)
+ ret = 0;
+ }
+out:
+ btrfs_release_path(path);
+ btrfs_free_path(dst_path);
+ return ret;
+}
+
+static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_inode *inode,
+ struct btrfs_path *path,
+ struct btrfs_log_ctx *ctx,
+ const u64 start,
+ const u64 end)
+{
+ 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;
+
+ INIT_LIST_HEAD(&extents);
+
+ 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) {
+ /*
+ * Skip extents outside our logging range. It's important to do
+ * it for correctness because if we don't ignore them, we may
+ * log them before their ordered extent completes, and therefore
+ * we could log them without logging their respective checksums
+ * (the checksum items are added to the csum tree at the very
+ * end of btrfs_finish_ordered_io()). Also leave such extents
+ * outside of our range in the list, since we may have another
+ * ranged fsync in the near future that needs them. If an extent
+ * outside our range corresponds to a hole, log it to avoid
+ * leaving gaps between extents (fsck will complain when we are
+ * not using the NO_HOLES feature).
+ */
+ if ((em->start > end || em->start + em->len <= start) &&
+ em->block_start != EXTENT_MAP_HOLE)
+ continue;
+
+ list_del_init(&em->list);
+ /*
+ * Just an arbitrary number, this can be really CPU intensive
+ * once we start getting a lot of extents, and really once we
+ * have a bunch of extents we just want to commit since it will
+ * be faster.
+ */
+ if (++num > 32768) {
+ list_del_init(&tree->modified_extents);
+ ret = -EFBIG;
+ goto process;
+ }
+
+ if (em->generation <= test_gen)
+ continue;
+
+ /* We log prealloc extents beyond eof later. */
+ if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) &&
+ 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);
+ list_add_tail(&em->list, &extents);
+ num++;
+ }
+
+ list_sort(NULL, &extents, extent_cmp);
+process:
+ while (!list_empty(&extents)) {
+ em = list_entry(extents.next, struct extent_map, list);
+
+ list_del_init(&em->list);
+
+ /*
+ * If we had an error we just need to delete everybody from our
+ * private list.
+ */
+ if (ret) {
+ clear_em_logging(tree, em);
+ free_extent_map(em);
+ continue;
+ }
+
+ write_unlock(&tree->lock);
+
+ ret = log_one_extent(trans, inode, root, em, path, ctx);
+ write_lock(&tree->lock);
+ clear_em_logging(tree, em);
+ free_extent_map(em);
+ }
+ WARN_ON(!list_empty(&extents));
+ write_unlock(&tree->lock);
+
+ btrfs_release_path(path);
+ if (!ret)
+ ret = btrfs_log_prealloc_extents(trans, inode, path);
+
+ return ret;
+}
+
+static int logged_inode_size(struct btrfs_root *log, struct btrfs_inode *inode,
+ struct btrfs_path *path, u64 *size_ret)
+{
+ struct btrfs_key key;
+ int ret;
+
+ key.objectid = btrfs_ino(inode);
+ key.type = BTRFS_INODE_ITEM_KEY;
+ key.offset = 0;
+
+ ret = btrfs_search_slot(NULL, log, &key, path, 0, 0);
+ if (ret < 0) {
+ return ret;
+ } else if (ret > 0) {
+ *size_ret = 0;
+ } else {
+ struct btrfs_inode_item *item;
+
+ item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_inode_item);
+ *size_ret = btrfs_inode_size(path->nodes[0], item);
+ }
+
+ btrfs_release_path(path);
+ return 0;
+}
+
+/*
+ * At the moment we always log all xattrs. This is to figure out at log replay
+ * time which xattrs must have their deletion replayed. If a xattr is missing
+ * in the log tree and exists in the fs/subvol tree, we delete it. This is
+ * because if a xattr is deleted, the inode is fsynced and a power failure
+ * happens, causing the log to be replayed the next time the fs is mounted,
+ * we want the xattr to not exist anymore (same behaviour as other filesystems
+ * with a journal, ext3/4, xfs, f2fs, etc).
+ */
+static int btrfs_log_all_xattrs(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_inode *inode,
+ struct btrfs_path *path,
+ struct btrfs_path *dst_path)
+{
+ int ret;
+ struct btrfs_key key;
+ const u64 ino = btrfs_ino(inode);
+ int ins_nr = 0;
+ int start_slot = 0;
+
+ key.objectid = ino;
+ key.type = BTRFS_XATTR_ITEM_KEY;
+ key.offset = 0;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ return ret;
+
+ while (true) {
+ int slot = path->slots[0];
+ struct extent_buffer *leaf = path->nodes[0];
+ int nritems = btrfs_header_nritems(leaf);
+
+ if (slot >= nritems) {
+ if (ins_nr > 0) {
+ u64 last_extent = 0;
+
+ ret = copy_items(trans, inode, dst_path, path,
+ &last_extent, start_slot,
+ ins_nr, 1, 0);
+ /* can't be 1, extent items aren't processed */
+ ASSERT(ret <= 0);
+ if (ret < 0)
+ return ret;
+ ins_nr = 0;
+ }
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ return ret;
+ else if (ret > 0)
+ break;
+ continue;
+ }
+
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+ if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY)
+ break;
+
+ if (ins_nr == 0)
+ start_slot = slot;
+ ins_nr++;
+ path->slots[0]++;
+ cond_resched();
+ }
+ if (ins_nr > 0) {
+ u64 last_extent = 0;
+
+ ret = copy_items(trans, inode, dst_path, path,
+ &last_extent, start_slot,
+ ins_nr, 1, 0);
+ /* can't be 1, extent items aren't processed */
+ ASSERT(ret <= 0);
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+/*
+ * If the no holes feature is enabled we need to make sure any hole between the
+ * last extent and the i_size of our inode is explicitly marked in the log. This
+ * is to make sure that doing something like:
+ *
+ * 1) create file with 128Kb of data
+ * 2) truncate file to 64Kb
+ * 3) truncate file to 256Kb
+ * 4) fsync file
+ * 5) <crash/power failure>
+ * 6) mount fs and trigger log replay
+ *
+ * Will give us a file with a size of 256Kb, the first 64Kb of data match what
+ * the file had in its first 64Kb of data at step 1 and the last 192Kb of the
+ * file correspond to a hole. The presence of explicit holes in a log tree is
+ * what guarantees that log replay will remove/adjust file extent items in the
+ * fs/subvol tree.
+ *
+ * Here we do not need to care about holes between extents, that is already done
+ * by copy_items(). We also only need to do this in the full sync path, where we
+ * lookup for extents from the fs/subvol tree only. In the fast path case, we
+ * lookup the list of modified extent maps and if any represents a hole, we
+ * insert a corresponding extent representing a hole in the log tree.
+ */
+static int btrfs_log_trailing_hole(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_inode *inode,
+ struct btrfs_path *path)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ int ret;
+ struct btrfs_key key;
+ u64 hole_start;
+ u64 hole_size;
+ struct extent_buffer *leaf;
+ struct btrfs_root *log = root->log_root;
+ const u64 ino = btrfs_ino(inode);
+ const u64 i_size = i_size_read(&inode->vfs_inode);
+
+ if (!btrfs_fs_incompat(fs_info, NO_HOLES))
+ return 0;
+
+ key.objectid = ino;
+ key.type = BTRFS_EXTENT_DATA_KEY;
+ key.offset = (u64)-1;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ ASSERT(ret != 0);
+ if (ret < 0)
+ return ret;
+
+ ASSERT(path->slots[0] > 0);
+ path->slots[0]--;
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+
+ if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY) {
+ /* inode does not have any extents */
+ hole_start = 0;
+ hole_size = i_size;
+ } else {
+ struct btrfs_file_extent_item *extent;
+ u64 len;
+
+ /*
+ * If there's an extent beyond i_size, an explicit hole was
+ * already inserted by copy_items().
+ */
+ if (key.offset >= i_size)
+ return 0;
+
+ extent = btrfs_item_ptr(leaf, path->slots[0],
+ 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));
+ return 0;
+ }
+
+ len = btrfs_file_extent_num_bytes(leaf, extent);
+ /* Last extent goes beyond i_size, no need to log a hole. */
+ if (key.offset + len > i_size)
+ return 0;
+ hole_start = key.offset + len;
+ hole_size = i_size - hole_start;
+ }
+ btrfs_release_path(path);
+
+ /* Last extent ends at i_size. */
+ if (hole_size == 0)
+ return 0;
+
+ hole_size = ALIGN(hole_size, fs_info->sectorsize);
+ ret = btrfs_insert_file_extent(trans, log, ino, hole_start, 0, 0,
+ hole_size, 0, hole_size, 0, 0, 0);
+ return ret;
+}
+
+/*
+ * When we are logging a new inode X, check if it doesn't have a reference that
+ * matches the reference from some other inode Y created in a past transaction
+ * and that was renamed in the current transaction. If we don't do this, then at
+ * log replay time we can lose inode Y (and all its files if it's a directory):
+ *
+ * mkdir /mnt/x
+ * echo "hello world" > /mnt/x/foobar
+ * sync
+ * mv /mnt/x /mnt/y
+ * mkdir /mnt/x # or touch /mnt/x
+ * xfs_io -c fsync /mnt/x
+ * <power fail>
+ * mount fs, trigger log replay
+ *
+ * After the log replay procedure, we would lose the first directory and all its
+ * files (file foobar).
+ * For the case where inode Y is not a directory we simply end up losing it:
+ *
+ * echo "123" > /mnt/foo
+ * sync
+ * mv /mnt/foo /mnt/bar
+ * echo "abc" > /mnt/foo
+ * xfs_io -c fsync /mnt/foo
+ * <power fail>
+ *
+ * We also need this for cases where a snapshot entry is replaced by some other
+ * entry (file or directory) otherwise we end up with an unreplayable log due to
+ * attempts to delete the snapshot entry (entry of type BTRFS_ROOT_ITEM_KEY) as
+ * if it were a regular entry:
+ *
+ * mkdir /mnt/x
+ * btrfs subvolume snapshot /mnt /mnt/x/snap
+ * btrfs subvolume delete /mnt/x/snap
+ * rmdir /mnt/x
+ * mkdir /mnt/x
+ * fsync /mnt/x or fsync some new file inside it
+ * <power fail>
+ *
+ * The snapshot delete, rmdir of x, mkdir of a new x and the fsync all happen in
+ * the same transaction.
+ */
+static int btrfs_check_ref_name_override(struct extent_buffer *eb,
+ const int slot,
+ const struct btrfs_key *key,
+ struct btrfs_inode *inode,
+ u64 *other_ino)
+{
+ int ret;
+ struct btrfs_path *search_path;
+ char *name = NULL;
+ u32 name_len = 0;
+ u32 item_size = btrfs_item_size_nr(eb, slot);
+ u32 cur_offset = 0;
+ unsigned long ptr = btrfs_item_ptr_offset(eb, slot);
+
+ search_path = btrfs_alloc_path();
+ if (!search_path)
+ return -ENOMEM;
+ search_path->search_commit_root = 1;
+ search_path->skip_locking = 1;
+
+ while (cur_offset < item_size) {
+ u64 parent;
+ u32 this_name_len;
+ u32 this_len;
+ unsigned long name_ptr;
+ struct btrfs_dir_item *di;
+
+ if (key->type == BTRFS_INODE_REF_KEY) {
+ struct btrfs_inode_ref *iref;
+
+ iref = (struct btrfs_inode_ref *)(ptr + cur_offset);
+ parent = key->offset;
+ this_name_len = btrfs_inode_ref_name_len(eb, iref);
+ name_ptr = (unsigned long)(iref + 1);
+ this_len = sizeof(*iref) + this_name_len;
+ } else {
+ struct btrfs_inode_extref *extref;
+
+ extref = (struct btrfs_inode_extref *)(ptr +
+ cur_offset);
+ parent = btrfs_inode_extref_parent(eb, extref);
+ this_name_len = btrfs_inode_extref_name_len(eb, extref);
+ name_ptr = (unsigned long)&extref->name;
+ this_len = sizeof(*extref) + this_name_len;
+ }
+
+ if (this_name_len > name_len) {
+ char *new_name;
+
+ new_name = krealloc(name, this_name_len, GFP_NOFS);
+ if (!new_name) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ name_len = this_name_len;
+ name = new_name;
+ }
+
+ read_extent_buffer(eb, name, name_ptr, this_name_len);
+ di = btrfs_lookup_dir_item(NULL, inode->root, search_path,
+ parent, name, this_name_len, 0);
+ if (di && !IS_ERR(di)) {
+ struct btrfs_key di_key;
+
+ 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;
+ } else {
+ ret = -EAGAIN;
+ }
+ goto out;
+ } else if (IS_ERR(di)) {
+ ret = PTR_ERR(di);
+ goto out;
+ }
+ btrfs_release_path(search_path);
+
+ cur_offset += this_len;
+ }
+ ret = 0;
+out:
+ btrfs_free_path(search_path);
+ kfree(name);
+ 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.
+ *
+ * Any items from this inode changed by the current transaction are copied
+ * to the log tree. An extra reference is taken on any extents in this
+ * file, allowing us to avoid a whole pile of corner cases around logging
+ * blocks that have been removed from the tree.
+ *
+ * See LOG_INODE_ALL and related defines for a description of what inode_only
+ * does.
+ *
+ * This handles both files and directories.
+ */
+static int btrfs_log_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct btrfs_inode *inode,
+ int inode_only,
+ const loff_t start,
+ const loff_t end,
+ struct btrfs_log_ctx *ctx)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_path *path;
+ struct btrfs_path *dst_path;
+ struct btrfs_key min_key;
+ struct btrfs_key max_key;
+ struct btrfs_root *log = root->log_root;
+ u64 last_extent = 0;
+ int err = 0;
+ int ret;
+ int nritems;
+ int ins_start_slot = 0;
+ int ins_nr;
+ bool fast_search = false;
+ u64 ino = btrfs_ino(inode);
+ struct extent_map_tree *em_tree = &inode->extent_tree;
+ u64 logged_isize = 0;
+ bool need_log_inode_item = true;
+ bool xattrs_logged = false;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+ dst_path = btrfs_alloc_path();
+ if (!dst_path) {
+ btrfs_free_path(path);
+ return -ENOMEM;
+ }
+
+ min_key.objectid = ino;
+ min_key.type = BTRFS_INODE_ITEM_KEY;
+ min_key.offset = 0;
+
+ max_key.objectid = ino;
+
+
+ /* today the code can only do partial logging of directories */
+ if (S_ISDIR(inode->vfs_inode.i_mode) ||
+ (!test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
+ &inode->runtime_flags) &&
+ inode_only >= LOG_INODE_EXISTS))
+ max_key.type = BTRFS_XATTR_ITEM_KEY;
+ else
+ max_key.type = (u8)-1;
+ max_key.offset = (u64)-1;
+
+ /*
+ * Only run delayed items if we are a dir or a new file.
+ * Otherwise commit the delayed inode only, which is needed in
+ * order for the log replay code to mark inodes for link count
+ * fixup (create temporary BTRFS_TREE_LOG_FIXUP_OBJECTID items).
+ */
+ if (S_ISDIR(inode->vfs_inode.i_mode) ||
+ inode->generation > fs_info->last_trans_committed)
+ ret = btrfs_commit_inode_delayed_items(trans, inode);
+ else
+ ret = btrfs_commit_inode_delayed_inode(inode);
+
+ if (ret) {
+ btrfs_free_path(path);
+ btrfs_free_path(dst_path);
+ return ret;
+ }
+
+ if (inode_only == LOG_OTHER_INODE) {
+ inode_only = LOG_INODE_EXISTS;
+ mutex_lock_nested(&inode->log_mutex, SINGLE_DEPTH_NESTING);
+ } else {
+ mutex_lock(&inode->log_mutex);
+ }
+
+ /*
+ * a brute force approach to making sure we get the most uptodate
+ * copies of everything.
+ */
+ if (S_ISDIR(inode->vfs_inode.i_mode)) {
+ int max_key_type = BTRFS_DIR_LOG_INDEX_KEY;
+
+ if (inode_only == LOG_INODE_EXISTS)
+ max_key_type = BTRFS_XATTR_ITEM_KEY;
+ ret = drop_objectid_items(trans, log, path, ino, max_key_type);
+ } else {
+ if (inode_only == LOG_INODE_EXISTS) {
+ /*
+ * Make sure the new inode item we write to the log has
+ * the same isize as the current one (if it exists).
+ * This is necessary to prevent data loss after log
+ * replay, and also to prevent doing a wrong expanding
+ * truncate - for e.g. create file, write 4K into offset
+ * 0, fsync, write 4K into offset 4096, add hard link,
+ * fsync some other file (to sync log), power fail - if
+ * we use the inode's current i_size, after log replay
+ * we get a 8Kb file, with the last 4Kb extent as a hole
+ * (zeroes), as if an expanding truncate happened,
+ * instead of getting a file of 4Kb only.
+ */
+ err = logged_inode_size(log, inode, path, &logged_isize);
+ if (err)
+ goto out_unlock;
+ }
+ if (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
+ &inode->runtime_flags)) {
+ if (inode_only == LOG_INODE_EXISTS) {
+ max_key.type = BTRFS_XATTR_ITEM_KEY;
+ ret = drop_objectid_items(trans, log, path, ino,
+ max_key.type);
+ } else {
+ clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
+ &inode->runtime_flags);
+ clear_bit(BTRFS_INODE_COPY_EVERYTHING,
+ &inode->runtime_flags);
+ while(1) {
+ ret = btrfs_truncate_inode_items(trans,
+ log, &inode->vfs_inode, 0, 0);
+ if (ret != -EAGAIN)
+ break;
+ }
+ }
+ } else if (test_and_clear_bit(BTRFS_INODE_COPY_EVERYTHING,
+ &inode->runtime_flags) ||
+ inode_only == LOG_INODE_EXISTS) {
+ if (inode_only == LOG_INODE_ALL)
+ fast_search = true;
+ max_key.type = BTRFS_XATTR_ITEM_KEY;
+ ret = drop_objectid_items(trans, log, path, ino,
+ max_key.type);
+ } else {
+ if (inode_only == LOG_INODE_ALL)
+ fast_search = true;
+ goto log_extents;
+ }
+
+ }
+ if (ret) {
+ err = ret;
+ goto out_unlock;
+ }
+
+ while (1) {
+ ins_nr = 0;
+ ret = btrfs_search_forward(root, &min_key,
+ path, trans->transid);
+ if (ret < 0) {
+ err = ret;
+ goto out_unlock;
+ }
+ if (ret != 0)
+ break;
+again:
+ /* note, ins_nr might be > 0 here, cleanup outside the loop */
+ if (min_key.objectid != ino)
+ break;
+ if (min_key.type > max_key.type)
+ break;
+
+ if (min_key.type == BTRFS_INODE_ITEM_KEY)
+ need_log_inode_item = false;
+
+ if ((min_key.type == BTRFS_INODE_REF_KEY ||
+ min_key.type == BTRFS_INODE_EXTREF_KEY) &&
+ inode->generation == trans->transid) {
+ u64 other_ino = 0;
+
+ ret = btrfs_check_ref_name_override(path->nodes[0],
+ path->slots[0], &min_key, inode,
+ &other_ino);
+ 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 {
+ ins_nr = 1;
+ ins_start_slot = path->slots[0];
+ }
+ ret = copy_items(trans, inode, dst_path, path,
+ &last_extent, ins_start_slot,
+ ins_nr, inode_only,
+ logged_isize);
+ if (ret < 0) {
+ err = ret;
+ 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);
+ if (err)
+ goto out_unlock;
+ else
+ goto next_key;
+ }
+ }
+
+ /* Skip xattrs, we log them later with btrfs_log_all_xattrs() */
+ if (min_key.type == BTRFS_XATTR_ITEM_KEY) {
+ if (ins_nr == 0)
+ goto next_slot;
+ ret = copy_items(trans, inode, dst_path, path,
+ &last_extent, ins_start_slot,
+ ins_nr, inode_only, logged_isize);
+ if (ret < 0) {
+ err = ret;
+ goto out_unlock;
+ }
+ ins_nr = 0;
+ if (ret) {
+ btrfs_release_path(path);
+ continue;
+ }
+ goto next_slot;
+ }
+
+ if (ins_nr && ins_start_slot + ins_nr == path->slots[0]) {
+ ins_nr++;
+ goto next_slot;
+ } else if (!ins_nr) {
+ ins_start_slot = path->slots[0];
+ ins_nr = 1;
+ goto next_slot;
+ }
+
+ ret = copy_items(trans, inode, dst_path, path, &last_extent,
+ ins_start_slot, ins_nr, inode_only,
+ logged_isize);
+ if (ret < 0) {
+ err = ret;
+ goto out_unlock;
+ }
+ if (ret) {
+ ins_nr = 0;
+ btrfs_release_path(path);
+ continue;
+ }
+ ins_nr = 1;
+ ins_start_slot = path->slots[0];
+next_slot:
+
+ nritems = btrfs_header_nritems(path->nodes[0]);
+ path->slots[0]++;
+ if (path->slots[0] < nritems) {
+ btrfs_item_key_to_cpu(path->nodes[0], &min_key,
+ path->slots[0]);
+ goto again;
+ }
+ if (ins_nr) {
+ ret = copy_items(trans, inode, dst_path, path,
+ &last_extent, ins_start_slot,
+ ins_nr, inode_only, logged_isize);
+ if (ret < 0) {
+ err = ret;
+ goto out_unlock;
+ }
+ ret = 0;
+ ins_nr = 0;
+ }
+ btrfs_release_path(path);
+next_key:
+ if (min_key.offset < (u64)-1) {
+ min_key.offset++;
+ } else if (min_key.type < max_key.type) {
+ min_key.type++;
+ min_key.offset = 0;
+ } else {
+ break;
+ }
+ }
+ if (ins_nr) {
+ ret = copy_items(trans, inode, dst_path, path, &last_extent,
+ ins_start_slot, ins_nr, inode_only,
+ logged_isize);
+ if (ret < 0) {
+ err = ret;
+ goto out_unlock;
+ }
+ ret = 0;
+ ins_nr = 0;
+ }
+
+ btrfs_release_path(path);
+ btrfs_release_path(dst_path);
+ err = btrfs_log_all_xattrs(trans, root, inode, path, dst_path);
+ if (err)
+ goto out_unlock;
+ xattrs_logged = true;
+ if (max_key.type >= BTRFS_EXTENT_DATA_KEY && !fast_search) {
+ btrfs_release_path(path);
+ btrfs_release_path(dst_path);
+ err = btrfs_log_trailing_hole(trans, root, inode, path);
+ if (err)
+ goto out_unlock;
+ }
+log_extents:
+ btrfs_release_path(path);
+ btrfs_release_path(dst_path);
+ if (need_log_inode_item) {
+ err = log_inode_item(trans, log, dst_path, inode);
+ if (!err && !xattrs_logged) {
+ err = btrfs_log_all_xattrs(trans, root, inode, path,
+ dst_path);
+ btrfs_release_path(path);
+ }
+ if (err)
+ goto out_unlock;
+ }
+ if (fast_search) {
+ ret = btrfs_log_changed_extents(trans, root, inode, dst_path,
+ ctx, start, end);
+ if (ret) {
+ err = ret;
+ goto out_unlock;
+ }
+ } else if (inode_only == LOG_INODE_ALL) {
+ struct extent_map *em, *n;
+
+ write_lock(&em_tree->lock);
+ /*
+ * We can't just remove every em if we're called for a ranged
+ * fsync - that is, one that doesn't cover the whole possible
+ * file range (0 to LLONG_MAX). This is because we can have
+ * em's that fall outside the range we're logging and therefore
+ * their ordered operations haven't completed yet
+ * (btrfs_finish_ordered_io() not invoked yet). This means we
+ * didn't get their respective file extent item in the fs/subvol
+ * tree yet, and need to let the next fast fsync (one which
+ * consults the list of modified extent maps) find the em so
+ * that it logs a matching file extent item and waits for the
+ * respective ordered operation to complete (if it's still
+ * running).
+ *
+ * Removing every em outside the range we're logging would make
+ * the next fast fsync not log their matching file extent items,
+ * therefore making us lose data after a log replay.
+ */
+ list_for_each_entry_safe(em, n, &em_tree->modified_extents,
+ list) {
+ const u64 mod_end = em->mod_start + em->mod_len - 1;
+
+ if (em->mod_start >= start && mod_end <= end)
+ list_del_init(&em->list);
+ }
+ write_unlock(&em_tree->lock);
+ }
+
+ if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->vfs_inode.i_mode)) {
+ ret = log_directory_changes(trans, root, inode, path, dst_path,
+ ctx);
+ if (ret) {
+ err = ret;
+ goto out_unlock;
+ }
+ }
+
+ spin_lock(&inode->lock);
+ inode->logged_trans = trans->transid;
+ inode->last_log_commit = inode->last_sub_trans;
+ spin_unlock(&inode->lock);
+out_unlock:
+ mutex_unlock(&inode->log_mutex);
+
+ btrfs_free_path(path);
+ btrfs_free_path(dst_path);
+ return err;
+}
+
+/*
+ * Check if we must fallback to a transaction commit when logging an inode.
+ * This must be called after logging the inode and is used only in the context
+ * when fsyncing an inode requires the need to log some other inode - in which
+ * case we can't lock the i_mutex of each other inode we need to log as that
+ * can lead to deadlocks with concurrent fsync against other inodes (as we can
+ * log inodes up or down in the hierarchy) or rename operations for example. So
+ * we take the log_mutex of the inode after we have logged it and then check for
+ * its last_unlink_trans value - this is safe because any task setting
+ * last_unlink_trans must take the log_mutex and it must do this before it does
+ * the actual unlink operation, so if we do this check before a concurrent task
+ * sets last_unlink_trans it means we've logged a consistent version/state of
+ * all the inode items, otherwise we are not sure and must do a transaction
+ * commit (the concurrent task might have only updated last_unlink_trans before
+ * we logged the inode or it might have also done the unlink).
+ */
+static bool btrfs_must_commit_transaction(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode)
+{
+ struct btrfs_fs_info *fs_info = inode->root->fs_info;
+ bool ret = false;
+
+ mutex_lock(&inode->log_mutex);
+ if (inode->last_unlink_trans > fs_info->last_trans_committed) {
+ /*
+ * Make sure any commits to the log are forced to be full
+ * commits.
+ */
+ btrfs_set_log_full_commit(fs_info, trans);
+ ret = true;
+ }
+ mutex_unlock(&inode->log_mutex);
+
+ return ret;
+}
+
+/*
+ * follow the dentry parent pointers up the chain and see if any
+ * of the directories in it require a full commit before they can
+ * be logged. Returns zero if nothing special needs to be done or 1 if
+ * a full commit is required.
+ */
+static noinline int check_parent_dirs_for_sync(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct dentry *parent,
+ struct super_block *sb,
+ u64 last_committed)
+{
+ 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
+ * have to worry about the parents at all. This is because
+ * we can use the last_unlink_trans field to record renames
+ * and other fun in this file.
+ */
+ if (S_ISREG(inode->vfs_inode.i_mode) &&
+ inode->generation <= last_committed &&
+ inode->last_unlink_trans <= last_committed)
+ goto out;
+
+ if (!S_ISDIR(inode->vfs_inode.i_mode)) {
+ if (!parent || d_really_is_negative(parent) || sb != parent->d_sb)
+ goto out;
+ inode = BTRFS_I(d_inode(parent));
+ }
+
+ 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;
+ }
+
+ if (!parent || d_really_is_negative(parent) || sb != parent->d_sb)
+ break;
+
+ if (IS_ROOT(parent)) {
+ inode = BTRFS_I(d_inode(parent));
+ if (btrfs_must_commit_transaction(trans, inode))
+ ret = 1;
+ break;
+ }
+
+ parent = dget_parent(parent);
+ dput(old_parent);
+ old_parent = parent;
+ inode = BTRFS_I(d_inode(parent));
+
+ }
+ dput(old_parent);
+out:
+ return ret;
+}
+
+struct btrfs_dir_list {
+ u64 ino;
+ struct list_head list;
+};
+
+/*
+ * Log the inodes of the new dentries of a directory. See log_dir_items() for
+ * details about the why it is needed.
+ * This is a recursive operation - if an existing dentry corresponds to a
+ * directory, that directory's new entries are logged too (same behaviour as
+ * ext3/4, xfs, f2fs, reiserfs, nilfs2). Note that when logging the inodes
+ * the dentries point to we do not lock their i_mutex, otherwise lockdep
+ * complains about the following circular lock dependency / possible deadlock:
+ *
+ * CPU0 CPU1
+ * ---- ----
+ * lock(&type->i_mutex_dir_key#3/2);
+ * lock(sb_internal#2);
+ * lock(&type->i_mutex_dir_key#3/2);
+ * lock(&sb->s_type->i_mutex_key#14);
+ *
+ * Where sb_internal is the lock (a counter that works as a lock) acquired by
+ * sb_start_intwrite() in btrfs_start_transaction().
+ * Not locking i_mutex of the inodes is still safe because:
+ *
+ * 1) For regular files we log with a mode of LOG_INODE_EXISTS. It's possible
+ * that while logging the inode new references (names) are added or removed
+ * from the inode, leaving the logged inode item with a link count that does
+ * not match the number of logged inode reference items. This is fine because
+ * at log replay time we compute the real number of links and correct the
+ * link count in the inode item (see replay_one_buffer() and
+ * link_to_fixup_dir());
+ *
+ * 2) For directories we log with a mode of LOG_INODE_ALL. It's possible that
+ * while logging the inode's items new items with keys BTRFS_DIR_ITEM_KEY and
+ * BTRFS_DIR_INDEX_KEY are added to fs/subvol tree and the logged inode item
+ * has a size that doesn't match the sum of the lengths of all the logged
+ * names. This does not result in a problem because if a dir_item key is
+ * logged but its matching dir_index key is not logged, at log replay time we
+ * don't use it to replay the respective name (see replay_one_name()). On the
+ * other hand if only the dir_index key ends up being logged, the respective
+ * name is added to the fs/subvol tree with both the dir_item and dir_index
+ * keys created (see replay_one_name()).
+ * The directory's inode item with a wrong i_size is not a problem as well,
+ * since we don't use it at log replay time to set the i_size in the inode
+ * item of the fs/subvol tree (see overwrite_item()).
+ */
+static int log_new_dir_dentries(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_inode *start_inode,
+ struct btrfs_log_ctx *ctx)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_root *log = root->log_root;
+ struct btrfs_path *path;
+ LIST_HEAD(dir_list);
+ struct btrfs_dir_list *dir_elem;
+ int ret = 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ dir_elem = kmalloc(sizeof(*dir_elem), GFP_NOFS);
+ if (!dir_elem) {
+ btrfs_free_path(path);
+ return -ENOMEM;
+ }
+ dir_elem->ino = btrfs_ino(start_inode);
+ list_add_tail(&dir_elem->list, &dir_list);
+
+ while (!list_empty(&dir_list)) {
+ struct extent_buffer *leaf;
+ struct btrfs_key min_key;
+ int nritems;
+ int i;
+
+ dir_elem = list_first_entry(&dir_list, struct btrfs_dir_list,
+ list);
+ if (ret)
+ goto next_dir_inode;
+
+ min_key.objectid = dir_elem->ino;
+ min_key.type = BTRFS_DIR_ITEM_KEY;
+ min_key.offset = 0;
+again:
+ btrfs_release_path(path);
+ ret = btrfs_search_forward(log, &min_key, path, trans->transid);
+ if (ret < 0) {
+ goto next_dir_inode;
+ } else if (ret > 0) {
+ ret = 0;
+ goto next_dir_inode;
+ }
+
+process_leaf:
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
+ for (i = path->slots[0]; i < nritems; i++) {
+ struct btrfs_dir_item *di;
+ struct btrfs_key di_key;
+ struct inode *di_inode;
+ struct btrfs_dir_list *new_dir_elem;
+ int log_mode = LOG_INODE_EXISTS;
+ int type;
+
+ btrfs_item_key_to_cpu(leaf, &min_key, i);
+ if (min_key.objectid != dir_elem->ino ||
+ min_key.type != BTRFS_DIR_ITEM_KEY)
+ goto next_dir_inode;
+
+ di = btrfs_item_ptr(leaf, i, struct btrfs_dir_item);
+ type = btrfs_dir_type(leaf, di);
+ if (btrfs_dir_transid(leaf, di) < trans->transid &&
+ type != BTRFS_FT_DIR)
+ continue;
+ btrfs_dir_item_key_to_cpu(leaf, di, &di_key);
+ if (di_key.type == BTRFS_ROOT_ITEM_KEY)
+ continue;
+
+ btrfs_release_path(path);
+ di_inode = btrfs_iget(fs_info->sb, &di_key, root, NULL);
+ if (IS_ERR(di_inode)) {
+ ret = PTR_ERR(di_inode);
+ goto next_dir_inode;
+ }
+
+ if (btrfs_inode_in_log(BTRFS_I(di_inode), trans->transid)) {
+ iput(di_inode);
+ break;
+ }
+
+ ctx->log_new_dentries = false;
+ if (type == BTRFS_FT_DIR || type == BTRFS_FT_SYMLINK)
+ log_mode = LOG_INODE_ALL;
+ ret = btrfs_log_inode(trans, root, BTRFS_I(di_inode),
+ log_mode, 0, LLONG_MAX, ctx);
+ if (!ret &&
+ btrfs_must_commit_transaction(trans, BTRFS_I(di_inode)))
+ ret = 1;
+ iput(di_inode);
+ if (ret)
+ goto next_dir_inode;
+ if (ctx->log_new_dentries) {
+ new_dir_elem = kmalloc(sizeof(*new_dir_elem),
+ GFP_NOFS);
+ if (!new_dir_elem) {
+ ret = -ENOMEM;
+ goto next_dir_inode;
+ }
+ new_dir_elem->ino = di_key.objectid;
+ list_add_tail(&new_dir_elem->list, &dir_list);
+ }
+ break;
+ }
+ if (i == nritems) {
+ ret = btrfs_next_leaf(log, path);
+ if (ret < 0) {
+ goto next_dir_inode;
+ } else if (ret > 0) {
+ ret = 0;
+ goto next_dir_inode;
+ }
+ goto process_leaf;
+ }
+ if (min_key.offset < (u64)-1) {
+ min_key.offset++;
+ goto again;
+ }
+next_dir_inode:
+ list_del(&dir_elem->list);
+ kfree(dir_elem);
+ }
+
+ btrfs_free_path(path);
+ return ret;
+}
+
+static int btrfs_log_all_parents(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct btrfs_log_ctx *ctx)
+{
+ struct btrfs_fs_info *fs_info = trans->fs_info;
+ int ret;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct btrfs_root *root = inode->root;
+ const u64 ino = btrfs_ino(inode);
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+ path->skip_locking = 1;
+ path->search_commit_root = 1;
+
+ 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)
+ goto out;
+
+ while (true) {
+ struct extent_buffer *leaf = path->nodes[0];
+ int slot = path->slots[0];
+ u32 cur_offset = 0;
+ u32 item_size;
+ unsigned long ptr;
+
+ 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, &key, slot);
+ /* BTRFS_INODE_EXTREF_KEY is BTRFS_INODE_REF_KEY + 1 */
+ if (key.objectid != ino || key.type > BTRFS_INODE_EXTREF_KEY)
+ break;
+
+ item_size = btrfs_item_size_nr(leaf, slot);
+ ptr = btrfs_item_ptr_offset(leaf, slot);
+ while (cur_offset < item_size) {
+ struct btrfs_key inode_key;
+ struct inode *dir_inode;
+
+ inode_key.type = BTRFS_INODE_ITEM_KEY;
+ inode_key.offset = 0;
+
+ if (key.type == BTRFS_INODE_EXTREF_KEY) {
+ struct btrfs_inode_extref *extref;
+
+ extref = (struct btrfs_inode_extref *)
+ (ptr + cur_offset);
+ inode_key.objectid = btrfs_inode_extref_parent(
+ leaf, extref);
+ cur_offset += sizeof(*extref);
+ cur_offset += btrfs_inode_extref_name_len(leaf,
+ extref);
+ } else {
+ inode_key.objectid = key.offset;
+ cur_offset = item_size;
+ }
+
+ dir_inode = btrfs_iget(fs_info->sb, &inode_key,
+ root, NULL);
+ /*
+ * If the parent inode was deleted, return an error to
+ * fallback to a transaction commit. This is to prevent
+ * getting an inode that was moved from one parent A to
+ * a parent B, got its former parent A deleted and then
+ * it got fsync'ed, from existing at both parents after
+ * a log replay (and the old parent still existing).
+ * Example:
+ *
+ * mkdir /mnt/A
+ * mkdir /mnt/B
+ * touch /mnt/B/bar
+ * sync
+ * mv /mnt/B/bar /mnt/A/bar
+ * mv -T /mnt/A /mnt/B
+ * fsync /mnt/B/bar
+ * <power fail>
+ *
+ * If we ignore the old parent B which got deleted,
+ * after a log replay we would have file bar linked
+ * at both parents and the old parent B would still
+ * exist.
+ */
+ if (IS_ERR(dir_inode)) {
+ ret = PTR_ERR(dir_inode);
+ goto out;
+ }
+
+ if (ctx)
+ ctx->log_new_dentries = false;
+ ret = btrfs_log_inode(trans, root, BTRFS_I(dir_inode),
+ LOG_INODE_ALL, 0, LLONG_MAX, ctx);
+ if (!ret &&
+ btrfs_must_commit_transaction(trans, BTRFS_I(dir_inode)))
+ ret = 1;
+ if (!ret && ctx && ctx->log_new_dentries)
+ ret = log_new_dir_dentries(trans, root,
+ BTRFS_I(dir_inode), ctx);
+ iput(dir_inode);
+ if (ret)
+ goto out;
+ }
+ path->slots[0]++;
+ }
+ 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
+ * only logging is done of any parent directories that are older than
+ * the last committed transaction
+ */
+static int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct dentry *parent,
+ const loff_t start,
+ const loff_t end,
+ int inode_only,
+ struct btrfs_log_ctx *ctx)
+{
+ 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;
+
+ if (btrfs_test_opt(fs_info, NOTREELOG)) {
+ ret = 1;
+ goto end_no_trans;
+ }
+
+ /*
+ * The prev transaction commit doesn't complete, we need do
+ * full commit by ourselves.
+ */
+ if (fs_info->last_trans_log_full_commit >
+ fs_info->last_trans_committed) {
+ ret = 1;
+ goto end_no_trans;
+ }
+
+ if (btrfs_root_refs(&root->root_item) == 0) {
+ ret = 1;
+ goto end_no_trans;
+ }
+
+ ret = check_parent_dirs_for_sync(trans, inode, parent, sb,
+ last_committed);
+ if (ret)
+ goto end_no_trans;
+
+ /*
+ * Skip already logged inodes or inodes corresponding to tmpfiles
+ * (since logging them is pointless, a link count of 0 means they
+ * will never be accessible).
+ */
+ if (btrfs_inode_in_log(inode, trans->transid) ||
+ inode->vfs_inode.i_nlink == 0) {
+ ret = BTRFS_NO_LOG_SYNC;
+ goto end_no_trans;
+ }
+
+ ret = start_log_trans(trans, root, ctx);
+ if (ret)
+ goto end_no_trans;
+
+ ret = btrfs_log_inode(trans, root, inode, inode_only, start, end, ctx);
+ if (ret)
+ goto end_trans;
+
+ /*
+ * for regular files, if its inode is already on disk, we don't
+ * have to worry about the parents at all. This is because
+ * we can use the last_unlink_trans field to record renames
+ * and other fun in this file.
+ */
+ if (S_ISREG(inode->vfs_inode.i_mode) &&
+ inode->generation <= last_committed &&
+ inode->last_unlink_trans <= last_committed) {
+ ret = 0;
+ goto end_trans;
+ }
+
+ if (S_ISDIR(inode->vfs_inode.i_mode) && ctx && ctx->log_new_dentries)
+ log_dentries = true;
+
+ /*
+ * On unlink we must make sure all our current and old parent directory
+ * inodes are fully logged. This is to prevent leaving dangling
+ * directory index entries in directories that were our parents but are
+ * not anymore. Not doing this results in old parent directory being
+ * impossible to delete after log replay (rmdir will always fail with
+ * error -ENOTEMPTY).
+ *
+ * Example 1:
+ *
+ * mkdir testdir
+ * touch testdir/foo
+ * ln testdir/foo testdir/bar
+ * sync
+ * unlink testdir/bar
+ * xfs_io -c fsync testdir/foo
+ * <power failure>
+ * mount fs, triggers log replay
+ *
+ * If we don't log the parent directory (testdir), after log replay the
+ * directory still has an entry pointing to the file inode using the bar
+ * name, but a matching BTRFS_INODE_[REF|EXTREF]_KEY does not exist and
+ * the file inode has a link count of 1.
+ *
+ * Example 2:
+ *
+ * mkdir testdir
+ * touch foo
+ * ln foo testdir/foo2
+ * ln foo testdir/foo3
+ * sync
+ * unlink testdir/foo3
+ * xfs_io -c fsync foo
+ * <power failure>
+ * mount fs, triggers log replay
+ *
+ * Similar as the first example, after log replay the parent directory
+ * testdir still has an entry pointing to the inode file with name foo3
+ * but the file inode does not have a matching BTRFS_INODE_REF_KEY item
+ * and has a link count of 2.
+ */
+ if (inode->last_unlink_trans > last_committed) {
+ ret = btrfs_log_all_parents(trans, orig_inode, ctx);
+ if (ret)
+ goto end_trans;
+ }
+
+ while (1) {
+ 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 > 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);
+ else
+ ret = 0;
+end_trans:
+ dput(old_parent);
+ if (ret < 0) {
+ btrfs_set_log_full_commit(fs_info, trans);
+ ret = 1;
+ }
+
+ if (ret)
+ btrfs_remove_log_ctx(root, ctx);
+ btrfs_end_log_trans(root);
+end_no_trans:
+ return ret;
+}
+
+/*
+ * it is not safe to log dentry if the chunk root has added new
+ * chunks. This returns 0 if the dentry was logged, and 1 otherwise.
+ * If this returns 1, you must commit the transaction to safely get your
+ * data on disk.
+ */
+int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
+ struct dentry *dentry,
+ const loff_t start,
+ const loff_t end,
+ struct btrfs_log_ctx *ctx)
+{
+ struct dentry *parent = dget_parent(dentry);
+ int ret;
+
+ ret = btrfs_log_inode_parent(trans, BTRFS_I(d_inode(dentry)), parent,
+ start, end, LOG_INODE_ALL, ctx);
+ dput(parent);
+
+ return ret;
+}
+
+/*
+ * should be called during mount to recover any replay any log trees
+ * from the FS
+ */
+int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
+{
+ int ret;
+ struct btrfs_path *path;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ struct btrfs_key tmp_key;
+ struct btrfs_root *log;
+ struct btrfs_fs_info *fs_info = log_root_tree->fs_info;
+ struct walk_control wc = {
+ .process_func = process_one_buffer,
+ .stage = 0,
+ };
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ set_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
+
+ trans = btrfs_start_transaction(fs_info->tree_root, 0);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ goto error;
+ }
+
+ wc.trans = trans;
+ wc.pin = 1;
+
+ ret = walk_log_tree(trans, log_root_tree, &wc);
+ if (ret) {
+ btrfs_handle_fs_error(fs_info, ret,
+ "Failed to pin buffers while recovering log root tree.");
+ goto error;
+ }
+
+again:
+ key.objectid = BTRFS_TREE_LOG_OBJECTID;
+ key.offset = (u64)-1;
+ key.type = BTRFS_ROOT_ITEM_KEY;
+
+ while (1) {
+ ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0);
+
+ if (ret < 0) {
+ btrfs_handle_fs_error(fs_info, ret,
+ "Couldn't find tree log root.");
+ goto error;
+ }
+ if (ret > 0) {
+ if (path->slots[0] == 0)
+ break;
+ path->slots[0]--;
+ }
+ btrfs_item_key_to_cpu(path->nodes[0], &found_key,
+ path->slots[0]);
+ btrfs_release_path(path);
+ if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID)
+ break;
+
+ log = btrfs_read_fs_root(log_root_tree, &found_key);
+ if (IS_ERR(log)) {
+ ret = PTR_ERR(log);
+ btrfs_handle_fs_error(fs_info, ret,
+ "Couldn't read tree log root.");
+ goto error;
+ }
+
+ tmp_key.objectid = found_key.offset;
+ tmp_key.type = BTRFS_ROOT_ITEM_KEY;
+ tmp_key.offset = (u64)-1;
+
+ wc.replay_dest = btrfs_read_fs_root_no_name(fs_info, &tmp_key);
+ if (IS_ERR(wc.replay_dest)) {
+ ret = PTR_ERR(wc.replay_dest);
+ free_extent_buffer(log->node);
+ free_extent_buffer(log->commit_root);
+ kfree(log);
+ btrfs_handle_fs_error(fs_info, ret,
+ "Couldn't read target root for tree log recovery.");
+ goto error;
+ }
+
+ wc.replay_dest->log_root = log;
+ btrfs_record_root_in_trans(trans, wc.replay_dest);
+ ret = walk_log_tree(trans, log, &wc);
+
+ if (!ret && wc.stage == LOG_WALK_REPLAY_ALL) {
+ ret = fixup_inode_link_counts(trans, wc.replay_dest,
+ path);
+ }
+
+ if (!ret && wc.stage == LOG_WALK_REPLAY_ALL) {
+ struct btrfs_root *root = wc.replay_dest;
+
+ btrfs_release_path(path);
+
+ /*
+ * We have just replayed everything, and the highest
+ * objectid of fs roots probably has changed in case
+ * some inode_item's got replayed.
+ *
+ * root->objectid_mutex is not acquired as log replay
+ * could only happen during mount.
+ */
+ ret = btrfs_find_highest_objectid(root,
+ &root->highest_objectid);
+ }
+
+ key.offset = found_key.offset - 1;
+ wc.replay_dest->log_root = NULL;
+ free_extent_buffer(log->node);
+ free_extent_buffer(log->commit_root);
+ kfree(log);
+
+ if (ret)
+ goto error;
+
+ if (found_key.offset == 0)
+ break;
+ }
+ btrfs_release_path(path);
+
+ /* step one is to pin it all, step two is to replay just inodes */
+ if (wc.pin) {
+ wc.pin = 0;
+ wc.process_func = replay_one_buffer;
+ wc.stage = LOG_WALK_REPLAY_INODES;
+ goto again;
+ }
+ /* step three is to replay everything */
+ if (wc.stage < LOG_WALK_REPLAY_ALL) {
+ wc.stage++;
+ goto again;
+ }
+
+ btrfs_free_path(path);
+
+ /* step 4: commit the transaction, which also unpins the blocks */
+ ret = btrfs_commit_transaction(trans);
+ if (ret)
+ return ret;
+
+ free_extent_buffer(log_root_tree->node);
+ log_root_tree->log_root = NULL;
+ clear_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
+ kfree(log_root_tree);
+
+ return 0;
+error:
+ if (wc.trans)
+ btrfs_end_transaction(wc.trans);
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * there are some corner cases where we want to force a full
+ * commit instead of allowing a directory to be logged.
+ *
+ * They revolve around files there were unlinked from the directory, and
+ * this function updates the parent directory so that a full commit is
+ * properly done if it is fsync'd later after the unlinks are done.
+ *
+ * Must be called before the unlink operations (updates to the subvolume tree,
+ * inodes, etc) are done.
+ */
+void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *dir, struct btrfs_inode *inode,
+ int for_rename)
+{
+ /*
+ * when we're logging a file, if it hasn't been renamed
+ * or unlinked, and its inode is fully committed on disk,
+ * we don't have to worry about walking up the directory chain
+ * to log its parents.
+ *
+ * So, we use the last_unlink_trans field to put this transid
+ * into the file. When the file is logged we check it and
+ * don't log the parents if the file is fully on disk.
+ */
+ mutex_lock(&inode->log_mutex);
+ inode->last_unlink_trans = trans->transid;
+ mutex_unlock(&inode->log_mutex);
+
+ /*
+ * 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;
+
+ /*
+ * if the inode we're about to unlink was logged,
+ * the log will be properly updated for any new names
+ */
+ if (inode->logged_trans == trans->transid)
+ return;
+
+ /*
+ * when renaming files across directories, if the directory
+ * there we're unlinking from gets fsync'd later on, there's
+ * no way to find the destination directory later and fsync it
+ * properly. So, we have to be conservative and force commits
+ * so the new name gets discovered.
+ */
+ if (for_rename)
+ goto record;
+
+ /* we can safely do the unlink without any special recording */
+ return;
+
+record:
+ mutex_lock(&dir->log_mutex);
+ dir->last_unlink_trans = trans->transid;
+ mutex_unlock(&dir->log_mutex);
+}
+
+/*
+ * Make sure that if someone attempts to fsync the parent directory of a deleted
+ * snapshot, it ends up triggering a transaction commit. This is to guarantee
+ * that after replaying the log tree of the parent directory's root we will not
+ * see the snapshot anymore and at log replay time we will not see any log tree
+ * corresponding to the deleted snapshot's root, which could lead to replaying
+ * it after replaying the log tree of the parent directory (which would replay
+ * the snapshot delete operation).
+ *
+ * Must be called before the actual snapshot destroy operation (updates to the
+ * parent root and tree of tree roots trees, etc) are done.
+ */
+void btrfs_record_snapshot_destroy(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *dir)
+{
+ mutex_lock(&dir->log_mutex);
+ dir->last_unlink_trans = trans->transid;
+ mutex_unlock(&dir->log_mutex);
+}
+
+/*
+ * Call this after adding a new name for a file and it will properly
+ * update the log to reflect the new name.
+ *
+ * @ctx can not be NULL when @sync_log is false, and should be NULL when it's
+ * true (because it's not used).
+ *
+ * Return value depends on whether @sync_log is true or false.
+ * When true: returns BTRFS_NEED_TRANS_COMMIT if the transaction needs to be
+ * committed by the caller, and BTRFS_DONT_NEED_TRANS_COMMIT
+ * otherwise.
+ * When false: returns BTRFS_DONT_NEED_LOG_SYNC if the caller does not need to
+ * to sync the log, BTRFS_NEED_LOG_SYNC if it needs to sync the log,
+ * or BTRFS_NEED_TRANS_COMMIT if the transaction needs to be
+ * committed (without attempting to sync the log).
+ */
+int btrfs_log_new_name(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode, struct btrfs_inode *old_dir,
+ struct dentry *parent,
+ bool sync_log, struct btrfs_log_ctx *ctx)
+{
+ struct btrfs_fs_info *fs_info = trans->fs_info;
+ int ret;
+
+ /*
+ * this will force the logging code to walk the dentry chain
+ * up for the file
+ */
+ if (!S_ISDIR(inode->vfs_inode.i_mode))
+ inode->last_unlink_trans = trans->transid;
+
+ /*
+ * if this inode hasn't been logged and directory we're renaming it
+ * from hasn't been logged, we don't need to log it
+ */
+ if (inode->logged_trans <= fs_info->last_trans_committed &&
+ (!old_dir || old_dir->logged_trans <= fs_info->last_trans_committed))
+ return sync_log ? BTRFS_DONT_NEED_TRANS_COMMIT :
+ BTRFS_DONT_NEED_LOG_SYNC;
+
+ if (sync_log) {
+ struct btrfs_log_ctx ctx2;
+
+ btrfs_init_log_ctx(&ctx2, &inode->vfs_inode);
+ ret = btrfs_log_inode_parent(trans, inode, parent, 0, LLONG_MAX,
+ LOG_INODE_EXISTS, &ctx2);
+ if (ret == BTRFS_NO_LOG_SYNC)
+ return BTRFS_DONT_NEED_TRANS_COMMIT;
+ else if (ret)
+ return BTRFS_NEED_TRANS_COMMIT;
+
+ ret = btrfs_sync_log(trans, inode->root, &ctx2);
+ if (ret)
+ return BTRFS_NEED_TRANS_COMMIT;
+ return BTRFS_DONT_NEED_TRANS_COMMIT;
+ }
+
+ ASSERT(ctx);
+ ret = btrfs_log_inode_parent(trans, inode, parent, 0, LLONG_MAX,
+ LOG_INODE_EXISTS, ctx);
+ if (ret == BTRFS_NO_LOG_SYNC)
+ return BTRFS_DONT_NEED_LOG_SYNC;
+ else if (ret)
+ return BTRFS_NEED_TRANS_COMMIT;
+
+ return BTRFS_NEED_LOG_SYNC;
+}
+