v4.19.13 snapshot.
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
new file mode 100644
index 0000000..8ecf8c0
--- /dev/null
+++ b/fs/btrfs/free-space-cache.c
@@ -0,0 +1,3715 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2008 Red Hat. All rights reserved.
+ */
+
+#include <linux/pagemap.h>
+#include <linux/sched.h>
+#include <linux/sched/signal.h>
+#include <linux/slab.h>
+#include <linux/math64.h>
+#include <linux/ratelimit.h>
+#include <linux/error-injection.h>
+#include <linux/sched/mm.h>
+#include "ctree.h"
+#include "free-space-cache.h"
+#include "transaction.h"
+#include "disk-io.h"
+#include "extent_io.h"
+#include "inode-map.h"
+#include "volumes.h"
+
+#define BITS_PER_BITMAP (PAGE_SIZE * 8UL)
+#define MAX_CACHE_BYTES_PER_GIG SZ_32K
+
+struct btrfs_trim_range {
+ u64 start;
+ u64 bytes;
+ struct list_head list;
+};
+
+static int link_free_space(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info);
+static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info);
+static int btrfs_wait_cache_io_root(struct btrfs_root *root,
+ struct btrfs_trans_handle *trans,
+ struct btrfs_io_ctl *io_ctl,
+ struct btrfs_path *path);
+
+static struct inode *__lookup_free_space_inode(struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 offset)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_key key;
+ struct btrfs_key location;
+ struct btrfs_disk_key disk_key;
+ struct btrfs_free_space_header *header;
+ struct extent_buffer *leaf;
+ struct inode *inode = NULL;
+ unsigned nofs_flag;
+ int ret;
+
+ key.objectid = BTRFS_FREE_SPACE_OBJECTID;
+ key.offset = offset;
+ key.type = 0;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ return ERR_PTR(ret);
+ if (ret > 0) {
+ btrfs_release_path(path);
+ return ERR_PTR(-ENOENT);
+ }
+
+ leaf = path->nodes[0];
+ header = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_free_space_header);
+ btrfs_free_space_key(leaf, header, &disk_key);
+ btrfs_disk_key_to_cpu(&location, &disk_key);
+ btrfs_release_path(path);
+
+ /*
+ * We are often under a trans handle at this point, so we need to make
+ * sure NOFS is set to keep us from deadlocking.
+ */
+ nofs_flag = memalloc_nofs_save();
+ inode = btrfs_iget(fs_info->sb, &location, root, NULL);
+ memalloc_nofs_restore(nofs_flag);
+ if (IS_ERR(inode))
+ return inode;
+
+ mapping_set_gfp_mask(inode->i_mapping,
+ mapping_gfp_constraint(inode->i_mapping,
+ ~(__GFP_FS | __GFP_HIGHMEM)));
+
+ return inode;
+}
+
+struct inode *lookup_free_space_inode(struct btrfs_fs_info *fs_info,
+ struct btrfs_block_group_cache
+ *block_group, struct btrfs_path *path)
+{
+ struct inode *inode = NULL;
+ u32 flags = BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
+
+ spin_lock(&block_group->lock);
+ if (block_group->inode)
+ inode = igrab(block_group->inode);
+ spin_unlock(&block_group->lock);
+ if (inode)
+ return inode;
+
+ inode = __lookup_free_space_inode(fs_info->tree_root, path,
+ block_group->key.objectid);
+ if (IS_ERR(inode))
+ return inode;
+
+ spin_lock(&block_group->lock);
+ if (!((BTRFS_I(inode)->flags & flags) == flags)) {
+ btrfs_info(fs_info, "Old style space inode found, converting.");
+ BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM |
+ BTRFS_INODE_NODATACOW;
+ block_group->disk_cache_state = BTRFS_DC_CLEAR;
+ }
+
+ if (!block_group->iref) {
+ block_group->inode = igrab(inode);
+ block_group->iref = 1;
+ }
+ spin_unlock(&block_group->lock);
+
+ return inode;
+}
+
+static int __create_free_space_inode(struct btrfs_root *root,
+ struct btrfs_trans_handle *trans,
+ struct btrfs_path *path,
+ u64 ino, u64 offset)
+{
+ struct btrfs_key key;
+ struct btrfs_disk_key disk_key;
+ struct btrfs_free_space_header *header;
+ struct btrfs_inode_item *inode_item;
+ struct extent_buffer *leaf;
+ u64 flags = BTRFS_INODE_NOCOMPRESS | BTRFS_INODE_PREALLOC;
+ int ret;
+
+ ret = btrfs_insert_empty_inode(trans, root, path, ino);
+ if (ret)
+ return ret;
+
+ /* We inline crc's for the free disk space cache */
+ if (ino != BTRFS_FREE_INO_OBJECTID)
+ flags |= BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
+
+ leaf = path->nodes[0];
+ inode_item = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_inode_item);
+ btrfs_item_key(leaf, &disk_key, path->slots[0]);
+ memzero_extent_buffer(leaf, (unsigned long)inode_item,
+ sizeof(*inode_item));
+ btrfs_set_inode_generation(leaf, inode_item, trans->transid);
+ btrfs_set_inode_size(leaf, inode_item, 0);
+ btrfs_set_inode_nbytes(leaf, inode_item, 0);
+ btrfs_set_inode_uid(leaf, inode_item, 0);
+ btrfs_set_inode_gid(leaf, inode_item, 0);
+ btrfs_set_inode_mode(leaf, inode_item, S_IFREG | 0600);
+ btrfs_set_inode_flags(leaf, inode_item, flags);
+ btrfs_set_inode_nlink(leaf, inode_item, 1);
+ btrfs_set_inode_transid(leaf, inode_item, trans->transid);
+ btrfs_set_inode_block_group(leaf, inode_item, offset);
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_release_path(path);
+
+ key.objectid = BTRFS_FREE_SPACE_OBJECTID;
+ key.offset = offset;
+ key.type = 0;
+ ret = btrfs_insert_empty_item(trans, root, path, &key,
+ sizeof(struct btrfs_free_space_header));
+ if (ret < 0) {
+ btrfs_release_path(path);
+ return ret;
+ }
+
+ leaf = path->nodes[0];
+ header = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_free_space_header);
+ memzero_extent_buffer(leaf, (unsigned long)header, sizeof(*header));
+ btrfs_set_free_space_key(leaf, header, &disk_key);
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_release_path(path);
+
+ return 0;
+}
+
+int create_free_space_inode(struct btrfs_fs_info *fs_info,
+ struct btrfs_trans_handle *trans,
+ struct btrfs_block_group_cache *block_group,
+ struct btrfs_path *path)
+{
+ int ret;
+ u64 ino;
+
+ ret = btrfs_find_free_objectid(fs_info->tree_root, &ino);
+ if (ret < 0)
+ return ret;
+
+ return __create_free_space_inode(fs_info->tree_root, trans, path, ino,
+ block_group->key.objectid);
+}
+
+int btrfs_check_trunc_cache_free_space(struct btrfs_fs_info *fs_info,
+ struct btrfs_block_rsv *rsv)
+{
+ u64 needed_bytes;
+ int ret;
+
+ /* 1 for slack space, 1 for updating the inode */
+ needed_bytes = btrfs_calc_trunc_metadata_size(fs_info, 1) +
+ btrfs_calc_trans_metadata_size(fs_info, 1);
+
+ spin_lock(&rsv->lock);
+ if (rsv->reserved < needed_bytes)
+ ret = -ENOSPC;
+ else
+ ret = 0;
+ spin_unlock(&rsv->lock);
+ return ret;
+}
+
+int btrfs_truncate_free_space_cache(struct btrfs_trans_handle *trans,
+ struct btrfs_block_group_cache *block_group,
+ struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret = 0;
+ bool locked = false;
+
+ if (block_group) {
+ struct btrfs_path *path = btrfs_alloc_path();
+
+ if (!path) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+ locked = true;
+ mutex_lock(&trans->transaction->cache_write_mutex);
+ if (!list_empty(&block_group->io_list)) {
+ list_del_init(&block_group->io_list);
+
+ btrfs_wait_cache_io(trans, block_group, path);
+ btrfs_put_block_group(block_group);
+ }
+
+ /*
+ * now that we've truncated the cache away, its no longer
+ * setup or written
+ */
+ spin_lock(&block_group->lock);
+ block_group->disk_cache_state = BTRFS_DC_CLEAR;
+ spin_unlock(&block_group->lock);
+ btrfs_free_path(path);
+ }
+
+ btrfs_i_size_write(BTRFS_I(inode), 0);
+ truncate_pagecache(inode, 0);
+
+ /*
+ * We skip the throttling logic for free space cache inodes, so we don't
+ * need to check for -EAGAIN.
+ */
+ ret = btrfs_truncate_inode_items(trans, root, inode,
+ 0, BTRFS_EXTENT_DATA_KEY);
+ if (ret)
+ goto fail;
+
+ ret = btrfs_update_inode(trans, root, inode);
+
+fail:
+ if (locked)
+ mutex_unlock(&trans->transaction->cache_write_mutex);
+ if (ret)
+ btrfs_abort_transaction(trans, ret);
+
+ return ret;
+}
+
+static void readahead_cache(struct inode *inode)
+{
+ struct file_ra_state *ra;
+ unsigned long last_index;
+
+ ra = kzalloc(sizeof(*ra), GFP_NOFS);
+ if (!ra)
+ return;
+
+ file_ra_state_init(ra, inode->i_mapping);
+ last_index = (i_size_read(inode) - 1) >> PAGE_SHIFT;
+
+ page_cache_sync_readahead(inode->i_mapping, ra, NULL, 0, last_index);
+
+ kfree(ra);
+}
+
+static int io_ctl_init(struct btrfs_io_ctl *io_ctl, struct inode *inode,
+ int write)
+{
+ int num_pages;
+ int check_crcs = 0;
+
+ num_pages = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
+
+ if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FREE_INO_OBJECTID)
+ check_crcs = 1;
+
+ /* Make sure we can fit our crcs and generation into the first page */
+ if (write && check_crcs &&
+ (num_pages * sizeof(u32) + sizeof(u64)) > PAGE_SIZE)
+ return -ENOSPC;
+
+ memset(io_ctl, 0, sizeof(struct btrfs_io_ctl));
+
+ io_ctl->pages = kcalloc(num_pages, sizeof(struct page *), GFP_NOFS);
+ if (!io_ctl->pages)
+ return -ENOMEM;
+
+ io_ctl->num_pages = num_pages;
+ io_ctl->fs_info = btrfs_sb(inode->i_sb);
+ io_ctl->check_crcs = check_crcs;
+ io_ctl->inode = inode;
+
+ return 0;
+}
+ALLOW_ERROR_INJECTION(io_ctl_init, ERRNO);
+
+static void io_ctl_free(struct btrfs_io_ctl *io_ctl)
+{
+ kfree(io_ctl->pages);
+ io_ctl->pages = NULL;
+}
+
+static void io_ctl_unmap_page(struct btrfs_io_ctl *io_ctl)
+{
+ if (io_ctl->cur) {
+ io_ctl->cur = NULL;
+ io_ctl->orig = NULL;
+ }
+}
+
+static void io_ctl_map_page(struct btrfs_io_ctl *io_ctl, int clear)
+{
+ ASSERT(io_ctl->index < io_ctl->num_pages);
+ io_ctl->page = io_ctl->pages[io_ctl->index++];
+ io_ctl->cur = page_address(io_ctl->page);
+ io_ctl->orig = io_ctl->cur;
+ io_ctl->size = PAGE_SIZE;
+ if (clear)
+ clear_page(io_ctl->cur);
+}
+
+static void io_ctl_drop_pages(struct btrfs_io_ctl *io_ctl)
+{
+ int i;
+
+ io_ctl_unmap_page(io_ctl);
+
+ for (i = 0; i < io_ctl->num_pages; i++) {
+ if (io_ctl->pages[i]) {
+ ClearPageChecked(io_ctl->pages[i]);
+ unlock_page(io_ctl->pages[i]);
+ put_page(io_ctl->pages[i]);
+ }
+ }
+}
+
+static int io_ctl_prepare_pages(struct btrfs_io_ctl *io_ctl, struct inode *inode,
+ int uptodate)
+{
+ struct page *page;
+ gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
+ int i;
+
+ for (i = 0; i < io_ctl->num_pages; i++) {
+ page = find_or_create_page(inode->i_mapping, i, mask);
+ if (!page) {
+ io_ctl_drop_pages(io_ctl);
+ return -ENOMEM;
+ }
+ io_ctl->pages[i] = page;
+ if (uptodate && !PageUptodate(page)) {
+ btrfs_readpage(NULL, page);
+ lock_page(page);
+ if (!PageUptodate(page)) {
+ btrfs_err(BTRFS_I(inode)->root->fs_info,
+ "error reading free space cache");
+ io_ctl_drop_pages(io_ctl);
+ return -EIO;
+ }
+ }
+ }
+
+ for (i = 0; i < io_ctl->num_pages; i++) {
+ clear_page_dirty_for_io(io_ctl->pages[i]);
+ set_page_extent_mapped(io_ctl->pages[i]);
+ }
+
+ return 0;
+}
+
+static void io_ctl_set_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
+{
+ __le64 *val;
+
+ io_ctl_map_page(io_ctl, 1);
+
+ /*
+ * Skip the csum areas. If we don't check crcs then we just have a
+ * 64bit chunk at the front of the first page.
+ */
+ if (io_ctl->check_crcs) {
+ io_ctl->cur += (sizeof(u32) * io_ctl->num_pages);
+ io_ctl->size -= sizeof(u64) + (sizeof(u32) * io_ctl->num_pages);
+ } else {
+ io_ctl->cur += sizeof(u64);
+ io_ctl->size -= sizeof(u64) * 2;
+ }
+
+ val = io_ctl->cur;
+ *val = cpu_to_le64(generation);
+ io_ctl->cur += sizeof(u64);
+}
+
+static int io_ctl_check_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
+{
+ __le64 *gen;
+
+ /*
+ * Skip the crc area. If we don't check crcs then we just have a 64bit
+ * chunk at the front of the first page.
+ */
+ if (io_ctl->check_crcs) {
+ io_ctl->cur += sizeof(u32) * io_ctl->num_pages;
+ io_ctl->size -= sizeof(u64) +
+ (sizeof(u32) * io_ctl->num_pages);
+ } else {
+ io_ctl->cur += sizeof(u64);
+ io_ctl->size -= sizeof(u64) * 2;
+ }
+
+ gen = io_ctl->cur;
+ if (le64_to_cpu(*gen) != generation) {
+ btrfs_err_rl(io_ctl->fs_info,
+ "space cache generation (%llu) does not match inode (%llu)",
+ *gen, generation);
+ io_ctl_unmap_page(io_ctl);
+ return -EIO;
+ }
+ io_ctl->cur += sizeof(u64);
+ return 0;
+}
+
+static void io_ctl_set_crc(struct btrfs_io_ctl *io_ctl, int index)
+{
+ u32 *tmp;
+ u32 crc = ~(u32)0;
+ unsigned offset = 0;
+
+ if (!io_ctl->check_crcs) {
+ io_ctl_unmap_page(io_ctl);
+ return;
+ }
+
+ if (index == 0)
+ offset = sizeof(u32) * io_ctl->num_pages;
+
+ crc = btrfs_csum_data(io_ctl->orig + offset, crc,
+ PAGE_SIZE - offset);
+ btrfs_csum_final(crc, (u8 *)&crc);
+ io_ctl_unmap_page(io_ctl);
+ tmp = page_address(io_ctl->pages[0]);
+ tmp += index;
+ *tmp = crc;
+}
+
+static int io_ctl_check_crc(struct btrfs_io_ctl *io_ctl, int index)
+{
+ u32 *tmp, val;
+ u32 crc = ~(u32)0;
+ unsigned offset = 0;
+
+ if (!io_ctl->check_crcs) {
+ io_ctl_map_page(io_ctl, 0);
+ return 0;
+ }
+
+ if (index == 0)
+ offset = sizeof(u32) * io_ctl->num_pages;
+
+ tmp = page_address(io_ctl->pages[0]);
+ tmp += index;
+ val = *tmp;
+
+ io_ctl_map_page(io_ctl, 0);
+ crc = btrfs_csum_data(io_ctl->orig + offset, crc,
+ PAGE_SIZE - offset);
+ btrfs_csum_final(crc, (u8 *)&crc);
+ if (val != crc) {
+ btrfs_err_rl(io_ctl->fs_info,
+ "csum mismatch on free space cache");
+ io_ctl_unmap_page(io_ctl);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static int io_ctl_add_entry(struct btrfs_io_ctl *io_ctl, u64 offset, u64 bytes,
+ void *bitmap)
+{
+ struct btrfs_free_space_entry *entry;
+
+ if (!io_ctl->cur)
+ return -ENOSPC;
+
+ entry = io_ctl->cur;
+ entry->offset = cpu_to_le64(offset);
+ entry->bytes = cpu_to_le64(bytes);
+ entry->type = (bitmap) ? BTRFS_FREE_SPACE_BITMAP :
+ BTRFS_FREE_SPACE_EXTENT;
+ io_ctl->cur += sizeof(struct btrfs_free_space_entry);
+ io_ctl->size -= sizeof(struct btrfs_free_space_entry);
+
+ if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
+ return 0;
+
+ io_ctl_set_crc(io_ctl, io_ctl->index - 1);
+
+ /* No more pages to map */
+ if (io_ctl->index >= io_ctl->num_pages)
+ return 0;
+
+ /* map the next page */
+ io_ctl_map_page(io_ctl, 1);
+ return 0;
+}
+
+static int io_ctl_add_bitmap(struct btrfs_io_ctl *io_ctl, void *bitmap)
+{
+ if (!io_ctl->cur)
+ return -ENOSPC;
+
+ /*
+ * If we aren't at the start of the current page, unmap this one and
+ * map the next one if there is any left.
+ */
+ if (io_ctl->cur != io_ctl->orig) {
+ io_ctl_set_crc(io_ctl, io_ctl->index - 1);
+ if (io_ctl->index >= io_ctl->num_pages)
+ return -ENOSPC;
+ io_ctl_map_page(io_ctl, 0);
+ }
+
+ copy_page(io_ctl->cur, bitmap);
+ io_ctl_set_crc(io_ctl, io_ctl->index - 1);
+ if (io_ctl->index < io_ctl->num_pages)
+ io_ctl_map_page(io_ctl, 0);
+ return 0;
+}
+
+static void io_ctl_zero_remaining_pages(struct btrfs_io_ctl *io_ctl)
+{
+ /*
+ * If we're not on the boundary we know we've modified the page and we
+ * need to crc the page.
+ */
+ if (io_ctl->cur != io_ctl->orig)
+ io_ctl_set_crc(io_ctl, io_ctl->index - 1);
+ else
+ io_ctl_unmap_page(io_ctl);
+
+ while (io_ctl->index < io_ctl->num_pages) {
+ io_ctl_map_page(io_ctl, 1);
+ io_ctl_set_crc(io_ctl, io_ctl->index - 1);
+ }
+}
+
+static int io_ctl_read_entry(struct btrfs_io_ctl *io_ctl,
+ struct btrfs_free_space *entry, u8 *type)
+{
+ struct btrfs_free_space_entry *e;
+ int ret;
+
+ if (!io_ctl->cur) {
+ ret = io_ctl_check_crc(io_ctl, io_ctl->index);
+ if (ret)
+ return ret;
+ }
+
+ e = io_ctl->cur;
+ entry->offset = le64_to_cpu(e->offset);
+ entry->bytes = le64_to_cpu(e->bytes);
+ *type = e->type;
+ io_ctl->cur += sizeof(struct btrfs_free_space_entry);
+ io_ctl->size -= sizeof(struct btrfs_free_space_entry);
+
+ if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
+ return 0;
+
+ io_ctl_unmap_page(io_ctl);
+
+ return 0;
+}
+
+static int io_ctl_read_bitmap(struct btrfs_io_ctl *io_ctl,
+ struct btrfs_free_space *entry)
+{
+ int ret;
+
+ ret = io_ctl_check_crc(io_ctl, io_ctl->index);
+ if (ret)
+ return ret;
+
+ copy_page(entry->bitmap, io_ctl->cur);
+ io_ctl_unmap_page(io_ctl);
+
+ return 0;
+}
+
+/*
+ * Since we attach pinned extents after the fact we can have contiguous sections
+ * of free space that are split up in entries. This poses a problem with the
+ * tree logging stuff since it could have allocated across what appears to be 2
+ * entries since we would have merged the entries when adding the pinned extents
+ * back to the free space cache. So run through the space cache that we just
+ * loaded and merge contiguous entries. This will make the log replay stuff not
+ * blow up and it will make for nicer allocator behavior.
+ */
+static void merge_space_tree(struct btrfs_free_space_ctl *ctl)
+{
+ struct btrfs_free_space *e, *prev = NULL;
+ struct rb_node *n;
+
+again:
+ spin_lock(&ctl->tree_lock);
+ for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
+ e = rb_entry(n, struct btrfs_free_space, offset_index);
+ if (!prev)
+ goto next;
+ if (e->bitmap || prev->bitmap)
+ goto next;
+ if (prev->offset + prev->bytes == e->offset) {
+ unlink_free_space(ctl, prev);
+ unlink_free_space(ctl, e);
+ prev->bytes += e->bytes;
+ kmem_cache_free(btrfs_free_space_cachep, e);
+ link_free_space(ctl, prev);
+ prev = NULL;
+ spin_unlock(&ctl->tree_lock);
+ goto again;
+ }
+next:
+ prev = e;
+ }
+ spin_unlock(&ctl->tree_lock);
+}
+
+static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
+ struct btrfs_free_space_ctl *ctl,
+ struct btrfs_path *path, u64 offset)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_free_space_header *header;
+ struct extent_buffer *leaf;
+ struct btrfs_io_ctl io_ctl;
+ struct btrfs_key key;
+ struct btrfs_free_space *e, *n;
+ LIST_HEAD(bitmaps);
+ u64 num_entries;
+ u64 num_bitmaps;
+ u64 generation;
+ u8 type;
+ int ret = 0;
+
+ /* Nothing in the space cache, goodbye */
+ if (!i_size_read(inode))
+ return 0;
+
+ key.objectid = BTRFS_FREE_SPACE_OBJECTID;
+ key.offset = offset;
+ key.type = 0;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ return 0;
+ else if (ret > 0) {
+ btrfs_release_path(path);
+ return 0;
+ }
+
+ ret = -1;
+
+ leaf = path->nodes[0];
+ header = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_free_space_header);
+ num_entries = btrfs_free_space_entries(leaf, header);
+ num_bitmaps = btrfs_free_space_bitmaps(leaf, header);
+ generation = btrfs_free_space_generation(leaf, header);
+ btrfs_release_path(path);
+
+ if (!BTRFS_I(inode)->generation) {
+ btrfs_info(fs_info,
+ "the free space cache file (%llu) is invalid, skip it",
+ offset);
+ return 0;
+ }
+
+ if (BTRFS_I(inode)->generation != generation) {
+ btrfs_err(fs_info,
+ "free space inode generation (%llu) did not match free space cache generation (%llu)",
+ BTRFS_I(inode)->generation, generation);
+ return 0;
+ }
+
+ if (!num_entries)
+ return 0;
+
+ ret = io_ctl_init(&io_ctl, inode, 0);
+ if (ret)
+ return ret;
+
+ readahead_cache(inode);
+
+ ret = io_ctl_prepare_pages(&io_ctl, inode, 1);
+ if (ret)
+ goto out;
+
+ ret = io_ctl_check_crc(&io_ctl, 0);
+ if (ret)
+ goto free_cache;
+
+ ret = io_ctl_check_generation(&io_ctl, generation);
+ if (ret)
+ goto free_cache;
+
+ while (num_entries) {
+ e = kmem_cache_zalloc(btrfs_free_space_cachep,
+ GFP_NOFS);
+ if (!e)
+ goto free_cache;
+
+ ret = io_ctl_read_entry(&io_ctl, e, &type);
+ if (ret) {
+ kmem_cache_free(btrfs_free_space_cachep, e);
+ goto free_cache;
+ }
+
+ if (!e->bytes) {
+ kmem_cache_free(btrfs_free_space_cachep, e);
+ goto free_cache;
+ }
+
+ if (type == BTRFS_FREE_SPACE_EXTENT) {
+ spin_lock(&ctl->tree_lock);
+ ret = link_free_space(ctl, e);
+ spin_unlock(&ctl->tree_lock);
+ if (ret) {
+ btrfs_err(fs_info,
+ "Duplicate entries in free space cache, dumping");
+ kmem_cache_free(btrfs_free_space_cachep, e);
+ goto free_cache;
+ }
+ } else {
+ ASSERT(num_bitmaps);
+ num_bitmaps--;
+ e->bitmap = kzalloc(PAGE_SIZE, GFP_NOFS);
+ if (!e->bitmap) {
+ kmem_cache_free(
+ btrfs_free_space_cachep, e);
+ goto free_cache;
+ }
+ spin_lock(&ctl->tree_lock);
+ ret = link_free_space(ctl, e);
+ ctl->total_bitmaps++;
+ ctl->op->recalc_thresholds(ctl);
+ spin_unlock(&ctl->tree_lock);
+ if (ret) {
+ btrfs_err(fs_info,
+ "Duplicate entries in free space cache, dumping");
+ kmem_cache_free(btrfs_free_space_cachep, e);
+ goto free_cache;
+ }
+ list_add_tail(&e->list, &bitmaps);
+ }
+
+ num_entries--;
+ }
+
+ io_ctl_unmap_page(&io_ctl);
+
+ /*
+ * We add the bitmaps at the end of the entries in order that
+ * the bitmap entries are added to the cache.
+ */
+ list_for_each_entry_safe(e, n, &bitmaps, list) {
+ list_del_init(&e->list);
+ ret = io_ctl_read_bitmap(&io_ctl, e);
+ if (ret)
+ goto free_cache;
+ }
+
+ io_ctl_drop_pages(&io_ctl);
+ merge_space_tree(ctl);
+ ret = 1;
+out:
+ io_ctl_free(&io_ctl);
+ return ret;
+free_cache:
+ io_ctl_drop_pages(&io_ctl);
+ __btrfs_remove_free_space_cache(ctl);
+ goto out;
+}
+
+int load_free_space_cache(struct btrfs_fs_info *fs_info,
+ struct btrfs_block_group_cache *block_group)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct inode *inode;
+ struct btrfs_path *path;
+ int ret = 0;
+ bool matched;
+ u64 used = btrfs_block_group_used(&block_group->item);
+
+ /*
+ * If this block group has been marked to be cleared for one reason or
+ * another then we can't trust the on disk cache, so just return.
+ */
+ spin_lock(&block_group->lock);
+ if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
+ spin_unlock(&block_group->lock);
+ return 0;
+ }
+ spin_unlock(&block_group->lock);
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return 0;
+ path->search_commit_root = 1;
+ path->skip_locking = 1;
+
+ inode = lookup_free_space_inode(fs_info, block_group, path);
+ if (IS_ERR(inode)) {
+ btrfs_free_path(path);
+ return 0;
+ }
+
+ /* We may have converted the inode and made the cache invalid. */
+ spin_lock(&block_group->lock);
+ if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
+ spin_unlock(&block_group->lock);
+ btrfs_free_path(path);
+ goto out;
+ }
+ spin_unlock(&block_group->lock);
+
+ ret = __load_free_space_cache(fs_info->tree_root, inode, ctl,
+ path, block_group->key.objectid);
+ btrfs_free_path(path);
+ if (ret <= 0)
+ goto out;
+
+ spin_lock(&ctl->tree_lock);
+ matched = (ctl->free_space == (block_group->key.offset - used -
+ block_group->bytes_super));
+ spin_unlock(&ctl->tree_lock);
+
+ if (!matched) {
+ __btrfs_remove_free_space_cache(ctl);
+ btrfs_warn(fs_info,
+ "block group %llu has wrong amount of free space",
+ block_group->key.objectid);
+ ret = -1;
+ }
+out:
+ if (ret < 0) {
+ /* This cache is bogus, make sure it gets cleared */
+ spin_lock(&block_group->lock);
+ block_group->disk_cache_state = BTRFS_DC_CLEAR;
+ spin_unlock(&block_group->lock);
+ ret = 0;
+
+ btrfs_warn(fs_info,
+ "failed to load free space cache for block group %llu, rebuilding it now",
+ block_group->key.objectid);
+ }
+
+ iput(inode);
+ return ret;
+}
+
+static noinline_for_stack
+int write_cache_extent_entries(struct btrfs_io_ctl *io_ctl,
+ struct btrfs_free_space_ctl *ctl,
+ struct btrfs_block_group_cache *block_group,
+ int *entries, int *bitmaps,
+ struct list_head *bitmap_list)
+{
+ int ret;
+ struct btrfs_free_cluster *cluster = NULL;
+ struct btrfs_free_cluster *cluster_locked = NULL;
+ struct rb_node *node = rb_first(&ctl->free_space_offset);
+ struct btrfs_trim_range *trim_entry;
+
+ /* Get the cluster for this block_group if it exists */
+ if (block_group && !list_empty(&block_group->cluster_list)) {
+ cluster = list_entry(block_group->cluster_list.next,
+ struct btrfs_free_cluster,
+ block_group_list);
+ }
+
+ if (!node && cluster) {
+ cluster_locked = cluster;
+ spin_lock(&cluster_locked->lock);
+ node = rb_first(&cluster->root);
+ cluster = NULL;
+ }
+
+ /* Write out the extent entries */
+ while (node) {
+ struct btrfs_free_space *e;
+
+ e = rb_entry(node, struct btrfs_free_space, offset_index);
+ *entries += 1;
+
+ ret = io_ctl_add_entry(io_ctl, e->offset, e->bytes,
+ e->bitmap);
+ if (ret)
+ goto fail;
+
+ if (e->bitmap) {
+ list_add_tail(&e->list, bitmap_list);
+ *bitmaps += 1;
+ }
+ node = rb_next(node);
+ if (!node && cluster) {
+ node = rb_first(&cluster->root);
+ cluster_locked = cluster;
+ spin_lock(&cluster_locked->lock);
+ cluster = NULL;
+ }
+ }
+ if (cluster_locked) {
+ spin_unlock(&cluster_locked->lock);
+ cluster_locked = NULL;
+ }
+
+ /*
+ * Make sure we don't miss any range that was removed from our rbtree
+ * because trimming is running. Otherwise after a umount+mount (or crash
+ * after committing the transaction) we would leak free space and get
+ * an inconsistent free space cache report from fsck.
+ */
+ list_for_each_entry(trim_entry, &ctl->trimming_ranges, list) {
+ ret = io_ctl_add_entry(io_ctl, trim_entry->start,
+ trim_entry->bytes, NULL);
+ if (ret)
+ goto fail;
+ *entries += 1;
+ }
+
+ return 0;
+fail:
+ if (cluster_locked)
+ spin_unlock(&cluster_locked->lock);
+ return -ENOSPC;
+}
+
+static noinline_for_stack int
+update_cache_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *inode,
+ struct btrfs_path *path, u64 offset,
+ int entries, int bitmaps)
+{
+ struct btrfs_key key;
+ struct btrfs_free_space_header *header;
+ struct extent_buffer *leaf;
+ int ret;
+
+ key.objectid = BTRFS_FREE_SPACE_OBJECTID;
+ key.offset = offset;
+ key.type = 0;
+
+ ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
+ if (ret < 0) {
+ clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
+ EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL);
+ goto fail;
+ }
+ leaf = path->nodes[0];
+ if (ret > 0) {
+ struct btrfs_key found_key;
+ ASSERT(path->slots[0]);
+ path->slots[0]--;
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID ||
+ found_key.offset != offset) {
+ clear_extent_bit(&BTRFS_I(inode)->io_tree, 0,
+ inode->i_size - 1,
+ EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0,
+ NULL);
+ btrfs_release_path(path);
+ goto fail;
+ }
+ }
+
+ BTRFS_I(inode)->generation = trans->transid;
+ header = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_free_space_header);
+ btrfs_set_free_space_entries(leaf, header, entries);
+ btrfs_set_free_space_bitmaps(leaf, header, bitmaps);
+ btrfs_set_free_space_generation(leaf, header, trans->transid);
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_release_path(path);
+
+ return 0;
+
+fail:
+ return -1;
+}
+
+static noinline_for_stack int
+write_pinned_extent_entries(struct btrfs_fs_info *fs_info,
+ struct btrfs_block_group_cache *block_group,
+ struct btrfs_io_ctl *io_ctl,
+ int *entries)
+{
+ u64 start, extent_start, extent_end, len;
+ struct extent_io_tree *unpin = NULL;
+ int ret;
+
+ if (!block_group)
+ return 0;
+
+ /*
+ * We want to add any pinned extents to our free space cache
+ * so we don't leak the space
+ *
+ * We shouldn't have switched the pinned extents yet so this is the
+ * right one
+ */
+ unpin = fs_info->pinned_extents;
+
+ start = block_group->key.objectid;
+
+ while (start < block_group->key.objectid + block_group->key.offset) {
+ ret = find_first_extent_bit(unpin, start,
+ &extent_start, &extent_end,
+ EXTENT_DIRTY, NULL);
+ if (ret)
+ return 0;
+
+ /* This pinned extent is out of our range */
+ if (extent_start >= block_group->key.objectid +
+ block_group->key.offset)
+ return 0;
+
+ extent_start = max(extent_start, start);
+ extent_end = min(block_group->key.objectid +
+ block_group->key.offset, extent_end + 1);
+ len = extent_end - extent_start;
+
+ *entries += 1;
+ ret = io_ctl_add_entry(io_ctl, extent_start, len, NULL);
+ if (ret)
+ return -ENOSPC;
+
+ start = extent_end;
+ }
+
+ return 0;
+}
+
+static noinline_for_stack int
+write_bitmap_entries(struct btrfs_io_ctl *io_ctl, struct list_head *bitmap_list)
+{
+ struct btrfs_free_space *entry, *next;
+ int ret;
+
+ /* Write out the bitmaps */
+ list_for_each_entry_safe(entry, next, bitmap_list, list) {
+ ret = io_ctl_add_bitmap(io_ctl, entry->bitmap);
+ if (ret)
+ return -ENOSPC;
+ list_del_init(&entry->list);
+ }
+
+ return 0;
+}
+
+static int flush_dirty_cache(struct inode *inode)
+{
+ int ret;
+
+ ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
+ if (ret)
+ clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
+ EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL);
+
+ return ret;
+}
+
+static void noinline_for_stack
+cleanup_bitmap_list(struct list_head *bitmap_list)
+{
+ struct btrfs_free_space *entry, *next;
+
+ list_for_each_entry_safe(entry, next, bitmap_list, list)
+ list_del_init(&entry->list);
+}
+
+static void noinline_for_stack
+cleanup_write_cache_enospc(struct inode *inode,
+ struct btrfs_io_ctl *io_ctl,
+ struct extent_state **cached_state)
+{
+ io_ctl_drop_pages(io_ctl);
+ unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
+ i_size_read(inode) - 1, cached_state);
+}
+
+static int __btrfs_wait_cache_io(struct btrfs_root *root,
+ struct btrfs_trans_handle *trans,
+ struct btrfs_block_group_cache *block_group,
+ struct btrfs_io_ctl *io_ctl,
+ struct btrfs_path *path, u64 offset)
+{
+ int ret;
+ struct inode *inode = io_ctl->inode;
+
+ if (!inode)
+ return 0;
+
+ /* Flush the dirty pages in the cache file. */
+ ret = flush_dirty_cache(inode);
+ if (ret)
+ goto out;
+
+ /* Update the cache item to tell everyone this cache file is valid. */
+ ret = update_cache_item(trans, root, inode, path, offset,
+ io_ctl->entries, io_ctl->bitmaps);
+out:
+ io_ctl_free(io_ctl);
+ if (ret) {
+ invalidate_inode_pages2(inode->i_mapping);
+ BTRFS_I(inode)->generation = 0;
+ if (block_group) {
+#ifdef DEBUG
+ btrfs_err(root->fs_info,
+ "failed to write free space cache for block group %llu",
+ block_group->key.objectid);
+#endif
+ }
+ }
+ btrfs_update_inode(trans, root, inode);
+
+ if (block_group) {
+ /* the dirty list is protected by the dirty_bgs_lock */
+ spin_lock(&trans->transaction->dirty_bgs_lock);
+
+ /* the disk_cache_state is protected by the block group lock */
+ spin_lock(&block_group->lock);
+
+ /*
+ * only mark this as written if we didn't get put back on
+ * the dirty list while waiting for IO. Otherwise our
+ * cache state won't be right, and we won't get written again
+ */
+ if (!ret && list_empty(&block_group->dirty_list))
+ block_group->disk_cache_state = BTRFS_DC_WRITTEN;
+ else if (ret)
+ block_group->disk_cache_state = BTRFS_DC_ERROR;
+
+ spin_unlock(&block_group->lock);
+ spin_unlock(&trans->transaction->dirty_bgs_lock);
+ io_ctl->inode = NULL;
+ iput(inode);
+ }
+
+ return ret;
+
+}
+
+static int btrfs_wait_cache_io_root(struct btrfs_root *root,
+ struct btrfs_trans_handle *trans,
+ struct btrfs_io_ctl *io_ctl,
+ struct btrfs_path *path)
+{
+ return __btrfs_wait_cache_io(root, trans, NULL, io_ctl, path, 0);
+}
+
+int btrfs_wait_cache_io(struct btrfs_trans_handle *trans,
+ struct btrfs_block_group_cache *block_group,
+ struct btrfs_path *path)
+{
+ return __btrfs_wait_cache_io(block_group->fs_info->tree_root, trans,
+ block_group, &block_group->io_ctl,
+ path, block_group->key.objectid);
+}
+
+/**
+ * __btrfs_write_out_cache - write out cached info to an inode
+ * @root - the root the inode belongs to
+ * @ctl - the free space cache we are going to write out
+ * @block_group - the block_group for this cache if it belongs to a block_group
+ * @trans - the trans handle
+ *
+ * This function writes out a free space cache struct to disk for quick recovery
+ * on mount. This will return 0 if it was successful in writing the cache out,
+ * or an errno if it was not.
+ */
+static int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
+ struct btrfs_free_space_ctl *ctl,
+ struct btrfs_block_group_cache *block_group,
+ struct btrfs_io_ctl *io_ctl,
+ struct btrfs_trans_handle *trans)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct extent_state *cached_state = NULL;
+ LIST_HEAD(bitmap_list);
+ int entries = 0;
+ int bitmaps = 0;
+ int ret;
+ int must_iput = 0;
+
+ if (!i_size_read(inode))
+ return -EIO;
+
+ WARN_ON(io_ctl->pages);
+ ret = io_ctl_init(io_ctl, inode, 1);
+ if (ret)
+ return ret;
+
+ if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA)) {
+ down_write(&block_group->data_rwsem);
+ spin_lock(&block_group->lock);
+ if (block_group->delalloc_bytes) {
+ block_group->disk_cache_state = BTRFS_DC_WRITTEN;
+ spin_unlock(&block_group->lock);
+ up_write(&block_group->data_rwsem);
+ BTRFS_I(inode)->generation = 0;
+ ret = 0;
+ must_iput = 1;
+ goto out;
+ }
+ spin_unlock(&block_group->lock);
+ }
+
+ /* Lock all pages first so we can lock the extent safely. */
+ ret = io_ctl_prepare_pages(io_ctl, inode, 0);
+ if (ret)
+ goto out_unlock;
+
+ lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
+ &cached_state);
+
+ io_ctl_set_generation(io_ctl, trans->transid);
+
+ mutex_lock(&ctl->cache_writeout_mutex);
+ /* Write out the extent entries in the free space cache */
+ spin_lock(&ctl->tree_lock);
+ ret = write_cache_extent_entries(io_ctl, ctl,
+ block_group, &entries, &bitmaps,
+ &bitmap_list);
+ if (ret)
+ goto out_nospc_locked;
+
+ /*
+ * Some spaces that are freed in the current transaction are pinned,
+ * they will be added into free space cache after the transaction is
+ * committed, we shouldn't lose them.
+ *
+ * If this changes while we are working we'll get added back to
+ * the dirty list and redo it. No locking needed
+ */
+ ret = write_pinned_extent_entries(fs_info, block_group,
+ io_ctl, &entries);
+ if (ret)
+ goto out_nospc_locked;
+
+ /*
+ * At last, we write out all the bitmaps and keep cache_writeout_mutex
+ * locked while doing it because a concurrent trim can be manipulating
+ * or freeing the bitmap.
+ */
+ ret = write_bitmap_entries(io_ctl, &bitmap_list);
+ spin_unlock(&ctl->tree_lock);
+ mutex_unlock(&ctl->cache_writeout_mutex);
+ if (ret)
+ goto out_nospc;
+
+ /* Zero out the rest of the pages just to make sure */
+ io_ctl_zero_remaining_pages(io_ctl);
+
+ /* Everything is written out, now we dirty the pages in the file. */
+ ret = btrfs_dirty_pages(inode, io_ctl->pages, io_ctl->num_pages, 0,
+ i_size_read(inode), &cached_state);
+ if (ret)
+ goto out_nospc;
+
+ if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
+ up_write(&block_group->data_rwsem);
+ /*
+ * Release the pages and unlock the extent, we will flush
+ * them out later
+ */
+ io_ctl_drop_pages(io_ctl);
+
+ unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
+ i_size_read(inode) - 1, &cached_state);
+
+ /*
+ * at this point the pages are under IO and we're happy,
+ * The caller is responsible for waiting on them and updating the
+ * the cache and the inode
+ */
+ io_ctl->entries = entries;
+ io_ctl->bitmaps = bitmaps;
+
+ ret = btrfs_fdatawrite_range(inode, 0, (u64)-1);
+ if (ret)
+ goto out;
+
+ return 0;
+
+out:
+ io_ctl->inode = NULL;
+ io_ctl_free(io_ctl);
+ if (ret) {
+ invalidate_inode_pages2(inode->i_mapping);
+ BTRFS_I(inode)->generation = 0;
+ }
+ btrfs_update_inode(trans, root, inode);
+ if (must_iput)
+ iput(inode);
+ return ret;
+
+out_nospc_locked:
+ cleanup_bitmap_list(&bitmap_list);
+ spin_unlock(&ctl->tree_lock);
+ mutex_unlock(&ctl->cache_writeout_mutex);
+
+out_nospc:
+ cleanup_write_cache_enospc(inode, io_ctl, &cached_state);
+
+out_unlock:
+ if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
+ up_write(&block_group->data_rwsem);
+
+ goto out;
+}
+
+int btrfs_write_out_cache(struct btrfs_fs_info *fs_info,
+ struct btrfs_trans_handle *trans,
+ struct btrfs_block_group_cache *block_group,
+ struct btrfs_path *path)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct inode *inode;
+ int ret = 0;
+
+ spin_lock(&block_group->lock);
+ if (block_group->disk_cache_state < BTRFS_DC_SETUP) {
+ spin_unlock(&block_group->lock);
+ return 0;
+ }
+ spin_unlock(&block_group->lock);
+
+ inode = lookup_free_space_inode(fs_info, block_group, path);
+ if (IS_ERR(inode))
+ return 0;
+
+ ret = __btrfs_write_out_cache(fs_info->tree_root, inode, ctl,
+ block_group, &block_group->io_ctl, trans);
+ if (ret) {
+#ifdef DEBUG
+ btrfs_err(fs_info,
+ "failed to write free space cache for block group %llu",
+ block_group->key.objectid);
+#endif
+ spin_lock(&block_group->lock);
+ block_group->disk_cache_state = BTRFS_DC_ERROR;
+ spin_unlock(&block_group->lock);
+
+ block_group->io_ctl.inode = NULL;
+ iput(inode);
+ }
+
+ /*
+ * if ret == 0 the caller is expected to call btrfs_wait_cache_io
+ * to wait for IO and put the inode
+ */
+
+ return ret;
+}
+
+static inline unsigned long offset_to_bit(u64 bitmap_start, u32 unit,
+ u64 offset)
+{
+ ASSERT(offset >= bitmap_start);
+ offset -= bitmap_start;
+ return (unsigned long)(div_u64(offset, unit));
+}
+
+static inline unsigned long bytes_to_bits(u64 bytes, u32 unit)
+{
+ return (unsigned long)(div_u64(bytes, unit));
+}
+
+static inline u64 offset_to_bitmap(struct btrfs_free_space_ctl *ctl,
+ u64 offset)
+{
+ u64 bitmap_start;
+ u64 bytes_per_bitmap;
+
+ bytes_per_bitmap = BITS_PER_BITMAP * ctl->unit;
+ bitmap_start = offset - ctl->start;
+ bitmap_start = div64_u64(bitmap_start, bytes_per_bitmap);
+ bitmap_start *= bytes_per_bitmap;
+ bitmap_start += ctl->start;
+
+ return bitmap_start;
+}
+
+static int tree_insert_offset(struct rb_root *root, u64 offset,
+ struct rb_node *node, int bitmap)
+{
+ struct rb_node **p = &root->rb_node;
+ struct rb_node *parent = NULL;
+ struct btrfs_free_space *info;
+
+ while (*p) {
+ parent = *p;
+ info = rb_entry(parent, struct btrfs_free_space, offset_index);
+
+ if (offset < info->offset) {
+ p = &(*p)->rb_left;
+ } else if (offset > info->offset) {
+ p = &(*p)->rb_right;
+ } else {
+ /*
+ * we could have a bitmap entry and an extent entry
+ * share the same offset. If this is the case, we want
+ * the extent entry to always be found first if we do a
+ * linear search through the tree, since we want to have
+ * the quickest allocation time, and allocating from an
+ * extent is faster than allocating from a bitmap. So
+ * if we're inserting a bitmap and we find an entry at
+ * this offset, we want to go right, or after this entry
+ * logically. If we are inserting an extent and we've
+ * found a bitmap, we want to go left, or before
+ * logically.
+ */
+ if (bitmap) {
+ if (info->bitmap) {
+ WARN_ON_ONCE(1);
+ return -EEXIST;
+ }
+ p = &(*p)->rb_right;
+ } else {
+ if (!info->bitmap) {
+ WARN_ON_ONCE(1);
+ return -EEXIST;
+ }
+ p = &(*p)->rb_left;
+ }
+ }
+ }
+
+ rb_link_node(node, parent, p);
+ rb_insert_color(node, root);
+
+ return 0;
+}
+
+/*
+ * searches the tree for the given offset.
+ *
+ * fuzzy - If this is set, then we are trying to make an allocation, and we just
+ * want a section that has at least bytes size and comes at or after the given
+ * offset.
+ */
+static struct btrfs_free_space *
+tree_search_offset(struct btrfs_free_space_ctl *ctl,
+ u64 offset, int bitmap_only, int fuzzy)
+{
+ struct rb_node *n = ctl->free_space_offset.rb_node;
+ struct btrfs_free_space *entry, *prev = NULL;
+
+ /* find entry that is closest to the 'offset' */
+ while (1) {
+ if (!n) {
+ entry = NULL;
+ break;
+ }
+
+ entry = rb_entry(n, struct btrfs_free_space, offset_index);
+ prev = entry;
+
+ if (offset < entry->offset)
+ n = n->rb_left;
+ else if (offset > entry->offset)
+ n = n->rb_right;
+ else
+ break;
+ }
+
+ if (bitmap_only) {
+ if (!entry)
+ return NULL;
+ if (entry->bitmap)
+ return entry;
+
+ /*
+ * bitmap entry and extent entry may share same offset,
+ * in that case, bitmap entry comes after extent entry.
+ */
+ n = rb_next(n);
+ if (!n)
+ return NULL;
+ entry = rb_entry(n, struct btrfs_free_space, offset_index);
+ if (entry->offset != offset)
+ return NULL;
+
+ WARN_ON(!entry->bitmap);
+ return entry;
+ } else if (entry) {
+ if (entry->bitmap) {
+ /*
+ * if previous extent entry covers the offset,
+ * we should return it instead of the bitmap entry
+ */
+ n = rb_prev(&entry->offset_index);
+ if (n) {
+ prev = rb_entry(n, struct btrfs_free_space,
+ offset_index);
+ if (!prev->bitmap &&
+ prev->offset + prev->bytes > offset)
+ entry = prev;
+ }
+ }
+ return entry;
+ }
+
+ if (!prev)
+ return NULL;
+
+ /* find last entry before the 'offset' */
+ entry = prev;
+ if (entry->offset > offset) {
+ n = rb_prev(&entry->offset_index);
+ if (n) {
+ entry = rb_entry(n, struct btrfs_free_space,
+ offset_index);
+ ASSERT(entry->offset <= offset);
+ } else {
+ if (fuzzy)
+ return entry;
+ else
+ return NULL;
+ }
+ }
+
+ if (entry->bitmap) {
+ n = rb_prev(&entry->offset_index);
+ if (n) {
+ prev = rb_entry(n, struct btrfs_free_space,
+ offset_index);
+ if (!prev->bitmap &&
+ prev->offset + prev->bytes > offset)
+ return prev;
+ }
+ if (entry->offset + BITS_PER_BITMAP * ctl->unit > offset)
+ return entry;
+ } else if (entry->offset + entry->bytes > offset)
+ return entry;
+
+ if (!fuzzy)
+ return NULL;
+
+ while (1) {
+ if (entry->bitmap) {
+ if (entry->offset + BITS_PER_BITMAP *
+ ctl->unit > offset)
+ break;
+ } else {
+ if (entry->offset + entry->bytes > offset)
+ break;
+ }
+
+ n = rb_next(&entry->offset_index);
+ if (!n)
+ return NULL;
+ entry = rb_entry(n, struct btrfs_free_space, offset_index);
+ }
+ return entry;
+}
+
+static inline void
+__unlink_free_space(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info)
+{
+ rb_erase(&info->offset_index, &ctl->free_space_offset);
+ ctl->free_extents--;
+}
+
+static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info)
+{
+ __unlink_free_space(ctl, info);
+ ctl->free_space -= info->bytes;
+}
+
+static int link_free_space(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info)
+{
+ int ret = 0;
+
+ ASSERT(info->bytes || info->bitmap);
+ ret = tree_insert_offset(&ctl->free_space_offset, info->offset,
+ &info->offset_index, (info->bitmap != NULL));
+ if (ret)
+ return ret;
+
+ ctl->free_space += info->bytes;
+ ctl->free_extents++;
+ return ret;
+}
+
+static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl)
+{
+ struct btrfs_block_group_cache *block_group = ctl->private;
+ u64 max_bytes;
+ u64 bitmap_bytes;
+ u64 extent_bytes;
+ u64 size = block_group->key.offset;
+ u64 bytes_per_bg = BITS_PER_BITMAP * ctl->unit;
+ u64 max_bitmaps = div64_u64(size + bytes_per_bg - 1, bytes_per_bg);
+
+ max_bitmaps = max_t(u64, max_bitmaps, 1);
+
+ ASSERT(ctl->total_bitmaps <= max_bitmaps);
+
+ /*
+ * The goal is to keep the total amount of memory used per 1gb of space
+ * at or below 32k, so we need to adjust how much memory we allow to be
+ * used by extent based free space tracking
+ */
+ if (size < SZ_1G)
+ max_bytes = MAX_CACHE_BYTES_PER_GIG;
+ else
+ max_bytes = MAX_CACHE_BYTES_PER_GIG * div_u64(size, SZ_1G);
+
+ /*
+ * we want to account for 1 more bitmap than what we have so we can make
+ * sure we don't go over our overall goal of MAX_CACHE_BYTES_PER_GIG as
+ * we add more bitmaps.
+ */
+ bitmap_bytes = (ctl->total_bitmaps + 1) * ctl->unit;
+
+ if (bitmap_bytes >= max_bytes) {
+ ctl->extents_thresh = 0;
+ return;
+ }
+
+ /*
+ * we want the extent entry threshold to always be at most 1/2 the max
+ * bytes we can have, or whatever is less than that.
+ */
+ extent_bytes = max_bytes - bitmap_bytes;
+ extent_bytes = min_t(u64, extent_bytes, max_bytes >> 1);
+
+ ctl->extents_thresh =
+ div_u64(extent_bytes, sizeof(struct btrfs_free_space));
+}
+
+static inline void __bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info,
+ u64 offset, u64 bytes)
+{
+ unsigned long start, count;
+
+ start = offset_to_bit(info->offset, ctl->unit, offset);
+ count = bytes_to_bits(bytes, ctl->unit);
+ ASSERT(start + count <= BITS_PER_BITMAP);
+
+ bitmap_clear(info->bitmap, start, count);
+
+ info->bytes -= bytes;
+ if (info->max_extent_size > ctl->unit)
+ info->max_extent_size = 0;
+}
+
+static void bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info, u64 offset,
+ u64 bytes)
+{
+ __bitmap_clear_bits(ctl, info, offset, bytes);
+ ctl->free_space -= bytes;
+}
+
+static void bitmap_set_bits(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info, u64 offset,
+ u64 bytes)
+{
+ unsigned long start, count;
+
+ start = offset_to_bit(info->offset, ctl->unit, offset);
+ count = bytes_to_bits(bytes, ctl->unit);
+ ASSERT(start + count <= BITS_PER_BITMAP);
+
+ bitmap_set(info->bitmap, start, count);
+
+ info->bytes += bytes;
+ ctl->free_space += bytes;
+}
+
+/*
+ * If we can not find suitable extent, we will use bytes to record
+ * the size of the max extent.
+ */
+static int search_bitmap(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *bitmap_info, u64 *offset,
+ u64 *bytes, bool for_alloc)
+{
+ unsigned long found_bits = 0;
+ unsigned long max_bits = 0;
+ unsigned long bits, i;
+ unsigned long next_zero;
+ unsigned long extent_bits;
+
+ /*
+ * Skip searching the bitmap if we don't have a contiguous section that
+ * is large enough for this allocation.
+ */
+ if (for_alloc &&
+ bitmap_info->max_extent_size &&
+ bitmap_info->max_extent_size < *bytes) {
+ *bytes = bitmap_info->max_extent_size;
+ return -1;
+ }
+
+ i = offset_to_bit(bitmap_info->offset, ctl->unit,
+ max_t(u64, *offset, bitmap_info->offset));
+ bits = bytes_to_bits(*bytes, ctl->unit);
+
+ for_each_set_bit_from(i, bitmap_info->bitmap, BITS_PER_BITMAP) {
+ if (for_alloc && bits == 1) {
+ found_bits = 1;
+ break;
+ }
+ next_zero = find_next_zero_bit(bitmap_info->bitmap,
+ BITS_PER_BITMAP, i);
+ extent_bits = next_zero - i;
+ if (extent_bits >= bits) {
+ found_bits = extent_bits;
+ break;
+ } else if (extent_bits > max_bits) {
+ max_bits = extent_bits;
+ }
+ i = next_zero;
+ }
+
+ if (found_bits) {
+ *offset = (u64)(i * ctl->unit) + bitmap_info->offset;
+ *bytes = (u64)(found_bits) * ctl->unit;
+ return 0;
+ }
+
+ *bytes = (u64)(max_bits) * ctl->unit;
+ bitmap_info->max_extent_size = *bytes;
+ return -1;
+}
+
+static inline u64 get_max_extent_size(struct btrfs_free_space *entry)
+{
+ if (entry->bitmap)
+ return entry->max_extent_size;
+ return entry->bytes;
+}
+
+/* Cache the size of the max extent in bytes */
+static struct btrfs_free_space *
+find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes,
+ unsigned long align, u64 *max_extent_size)
+{
+ struct btrfs_free_space *entry;
+ struct rb_node *node;
+ u64 tmp;
+ u64 align_off;
+ int ret;
+
+ if (!ctl->free_space_offset.rb_node)
+ goto out;
+
+ entry = tree_search_offset(ctl, offset_to_bitmap(ctl, *offset), 0, 1);
+ if (!entry)
+ goto out;
+
+ for (node = &entry->offset_index; node; node = rb_next(node)) {
+ entry = rb_entry(node, struct btrfs_free_space, offset_index);
+ if (entry->bytes < *bytes) {
+ *max_extent_size = max(get_max_extent_size(entry),
+ *max_extent_size);
+ continue;
+ }
+
+ /* make sure the space returned is big enough
+ * to match our requested alignment
+ */
+ if (*bytes >= align) {
+ tmp = entry->offset - ctl->start + align - 1;
+ tmp = div64_u64(tmp, align);
+ tmp = tmp * align + ctl->start;
+ align_off = tmp - entry->offset;
+ } else {
+ align_off = 0;
+ tmp = entry->offset;
+ }
+
+ if (entry->bytes < *bytes + align_off) {
+ *max_extent_size = max(get_max_extent_size(entry),
+ *max_extent_size);
+ continue;
+ }
+
+ if (entry->bitmap) {
+ u64 size = *bytes;
+
+ ret = search_bitmap(ctl, entry, &tmp, &size, true);
+ if (!ret) {
+ *offset = tmp;
+ *bytes = size;
+ return entry;
+ } else {
+ *max_extent_size =
+ max(get_max_extent_size(entry),
+ *max_extent_size);
+ }
+ continue;
+ }
+
+ *offset = tmp;
+ *bytes = entry->bytes - align_off;
+ return entry;
+ }
+out:
+ return NULL;
+}
+
+static void add_new_bitmap(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info, u64 offset)
+{
+ info->offset = offset_to_bitmap(ctl, offset);
+ info->bytes = 0;
+ INIT_LIST_HEAD(&info->list);
+ link_free_space(ctl, info);
+ ctl->total_bitmaps++;
+
+ ctl->op->recalc_thresholds(ctl);
+}
+
+static void free_bitmap(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *bitmap_info)
+{
+ unlink_free_space(ctl, bitmap_info);
+ kfree(bitmap_info->bitmap);
+ kmem_cache_free(btrfs_free_space_cachep, bitmap_info);
+ ctl->total_bitmaps--;
+ ctl->op->recalc_thresholds(ctl);
+}
+
+static noinline int remove_from_bitmap(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *bitmap_info,
+ u64 *offset, u64 *bytes)
+{
+ u64 end;
+ u64 search_start, search_bytes;
+ int ret;
+
+again:
+ end = bitmap_info->offset + (u64)(BITS_PER_BITMAP * ctl->unit) - 1;
+
+ /*
+ * We need to search for bits in this bitmap. We could only cover some
+ * of the extent in this bitmap thanks to how we add space, so we need
+ * to search for as much as it as we can and clear that amount, and then
+ * go searching for the next bit.
+ */
+ search_start = *offset;
+ search_bytes = ctl->unit;
+ search_bytes = min(search_bytes, end - search_start + 1);
+ ret = search_bitmap(ctl, bitmap_info, &search_start, &search_bytes,
+ false);
+ if (ret < 0 || search_start != *offset)
+ return -EINVAL;
+
+ /* We may have found more bits than what we need */
+ search_bytes = min(search_bytes, *bytes);
+
+ /* Cannot clear past the end of the bitmap */
+ search_bytes = min(search_bytes, end - search_start + 1);
+
+ bitmap_clear_bits(ctl, bitmap_info, search_start, search_bytes);
+ *offset += search_bytes;
+ *bytes -= search_bytes;
+
+ if (*bytes) {
+ struct rb_node *next = rb_next(&bitmap_info->offset_index);
+ if (!bitmap_info->bytes)
+ free_bitmap(ctl, bitmap_info);
+
+ /*
+ * no entry after this bitmap, but we still have bytes to
+ * remove, so something has gone wrong.
+ */
+ if (!next)
+ return -EINVAL;
+
+ bitmap_info = rb_entry(next, struct btrfs_free_space,
+ offset_index);
+
+ /*
+ * if the next entry isn't a bitmap we need to return to let the
+ * extent stuff do its work.
+ */
+ if (!bitmap_info->bitmap)
+ return -EAGAIN;
+
+ /*
+ * Ok the next item is a bitmap, but it may not actually hold
+ * the information for the rest of this free space stuff, so
+ * look for it, and if we don't find it return so we can try
+ * everything over again.
+ */
+ search_start = *offset;
+ search_bytes = ctl->unit;
+ ret = search_bitmap(ctl, bitmap_info, &search_start,
+ &search_bytes, false);
+ if (ret < 0 || search_start != *offset)
+ return -EAGAIN;
+
+ goto again;
+ } else if (!bitmap_info->bytes)
+ free_bitmap(ctl, bitmap_info);
+
+ return 0;
+}
+
+static u64 add_bytes_to_bitmap(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info, u64 offset,
+ u64 bytes)
+{
+ u64 bytes_to_set = 0;
+ u64 end;
+
+ end = info->offset + (u64)(BITS_PER_BITMAP * ctl->unit);
+
+ bytes_to_set = min(end - offset, bytes);
+
+ bitmap_set_bits(ctl, info, offset, bytes_to_set);
+
+ /*
+ * We set some bytes, we have no idea what the max extent size is
+ * anymore.
+ */
+ info->max_extent_size = 0;
+
+ return bytes_to_set;
+
+}
+
+static bool use_bitmap(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info)
+{
+ struct btrfs_block_group_cache *block_group = ctl->private;
+ struct btrfs_fs_info *fs_info = block_group->fs_info;
+ bool forced = false;
+
+#ifdef CONFIG_BTRFS_DEBUG
+ if (btrfs_should_fragment_free_space(block_group))
+ forced = true;
+#endif
+
+ /*
+ * If we are below the extents threshold then we can add this as an
+ * extent, and don't have to deal with the bitmap
+ */
+ if (!forced && ctl->free_extents < ctl->extents_thresh) {
+ /*
+ * If this block group has some small extents we don't want to
+ * use up all of our free slots in the cache with them, we want
+ * to reserve them to larger extents, however if we have plenty
+ * of cache left then go ahead an dadd them, no sense in adding
+ * the overhead of a bitmap if we don't have to.
+ */
+ if (info->bytes <= fs_info->sectorsize * 4) {
+ if (ctl->free_extents * 2 <= ctl->extents_thresh)
+ return false;
+ } else {
+ return false;
+ }
+ }
+
+ /*
+ * The original block groups from mkfs can be really small, like 8
+ * megabytes, so don't bother with a bitmap for those entries. However
+ * some block groups can be smaller than what a bitmap would cover but
+ * are still large enough that they could overflow the 32k memory limit,
+ * so allow those block groups to still be allowed to have a bitmap
+ * entry.
+ */
+ if (((BITS_PER_BITMAP * ctl->unit) >> 1) > block_group->key.offset)
+ return false;
+
+ return true;
+}
+
+static const struct btrfs_free_space_op free_space_op = {
+ .recalc_thresholds = recalculate_thresholds,
+ .use_bitmap = use_bitmap,
+};
+
+static int insert_into_bitmap(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info)
+{
+ struct btrfs_free_space *bitmap_info;
+ struct btrfs_block_group_cache *block_group = NULL;
+ int added = 0;
+ u64 bytes, offset, bytes_added;
+ int ret;
+
+ bytes = info->bytes;
+ offset = info->offset;
+
+ if (!ctl->op->use_bitmap(ctl, info))
+ return 0;
+
+ if (ctl->op == &free_space_op)
+ block_group = ctl->private;
+again:
+ /*
+ * Since we link bitmaps right into the cluster we need to see if we
+ * have a cluster here, and if so and it has our bitmap we need to add
+ * the free space to that bitmap.
+ */
+ if (block_group && !list_empty(&block_group->cluster_list)) {
+ struct btrfs_free_cluster *cluster;
+ struct rb_node *node;
+ struct btrfs_free_space *entry;
+
+ cluster = list_entry(block_group->cluster_list.next,
+ struct btrfs_free_cluster,
+ block_group_list);
+ spin_lock(&cluster->lock);
+ node = rb_first(&cluster->root);
+ if (!node) {
+ spin_unlock(&cluster->lock);
+ goto no_cluster_bitmap;
+ }
+
+ entry = rb_entry(node, struct btrfs_free_space, offset_index);
+ if (!entry->bitmap) {
+ spin_unlock(&cluster->lock);
+ goto no_cluster_bitmap;
+ }
+
+ if (entry->offset == offset_to_bitmap(ctl, offset)) {
+ bytes_added = add_bytes_to_bitmap(ctl, entry,
+ offset, bytes);
+ bytes -= bytes_added;
+ offset += bytes_added;
+ }
+ spin_unlock(&cluster->lock);
+ if (!bytes) {
+ ret = 1;
+ goto out;
+ }
+ }
+
+no_cluster_bitmap:
+ bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
+ 1, 0);
+ if (!bitmap_info) {
+ ASSERT(added == 0);
+ goto new_bitmap;
+ }
+
+ bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes);
+ bytes -= bytes_added;
+ offset += bytes_added;
+ added = 0;
+
+ if (!bytes) {
+ ret = 1;
+ goto out;
+ } else
+ goto again;
+
+new_bitmap:
+ if (info && info->bitmap) {
+ add_new_bitmap(ctl, info, offset);
+ added = 1;
+ info = NULL;
+ goto again;
+ } else {
+ spin_unlock(&ctl->tree_lock);
+
+ /* no pre-allocated info, allocate a new one */
+ if (!info) {
+ info = kmem_cache_zalloc(btrfs_free_space_cachep,
+ GFP_NOFS);
+ if (!info) {
+ spin_lock(&ctl->tree_lock);
+ ret = -ENOMEM;
+ goto out;
+ }
+ }
+
+ /* allocate the bitmap */
+ info->bitmap = kzalloc(PAGE_SIZE, GFP_NOFS);
+ spin_lock(&ctl->tree_lock);
+ if (!info->bitmap) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ goto again;
+ }
+
+out:
+ if (info) {
+ if (info->bitmap)
+ kfree(info->bitmap);
+ kmem_cache_free(btrfs_free_space_cachep, info);
+ }
+
+ return ret;
+}
+
+static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info, bool update_stat)
+{
+ struct btrfs_free_space *left_info;
+ struct btrfs_free_space *right_info;
+ bool merged = false;
+ u64 offset = info->offset;
+ u64 bytes = info->bytes;
+
+ /*
+ * first we want to see if there is free space adjacent to the range we
+ * are adding, if there is remove that struct and add a new one to
+ * cover the entire range
+ */
+ right_info = tree_search_offset(ctl, offset + bytes, 0, 0);
+ if (right_info && rb_prev(&right_info->offset_index))
+ left_info = rb_entry(rb_prev(&right_info->offset_index),
+ struct btrfs_free_space, offset_index);
+ else
+ left_info = tree_search_offset(ctl, offset - 1, 0, 0);
+
+ if (right_info && !right_info->bitmap) {
+ if (update_stat)
+ unlink_free_space(ctl, right_info);
+ else
+ __unlink_free_space(ctl, right_info);
+ info->bytes += right_info->bytes;
+ kmem_cache_free(btrfs_free_space_cachep, right_info);
+ merged = true;
+ }
+
+ if (left_info && !left_info->bitmap &&
+ left_info->offset + left_info->bytes == offset) {
+ if (update_stat)
+ unlink_free_space(ctl, left_info);
+ else
+ __unlink_free_space(ctl, left_info);
+ info->offset = left_info->offset;
+ info->bytes += left_info->bytes;
+ kmem_cache_free(btrfs_free_space_cachep, left_info);
+ merged = true;
+ }
+
+ return merged;
+}
+
+static bool steal_from_bitmap_to_end(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info,
+ bool update_stat)
+{
+ struct btrfs_free_space *bitmap;
+ unsigned long i;
+ unsigned long j;
+ const u64 end = info->offset + info->bytes;
+ const u64 bitmap_offset = offset_to_bitmap(ctl, end);
+ u64 bytes;
+
+ bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
+ if (!bitmap)
+ return false;
+
+ i = offset_to_bit(bitmap->offset, ctl->unit, end);
+ j = find_next_zero_bit(bitmap->bitmap, BITS_PER_BITMAP, i);
+ if (j == i)
+ return false;
+ bytes = (j - i) * ctl->unit;
+ info->bytes += bytes;
+
+ if (update_stat)
+ bitmap_clear_bits(ctl, bitmap, end, bytes);
+ else
+ __bitmap_clear_bits(ctl, bitmap, end, bytes);
+
+ if (!bitmap->bytes)
+ free_bitmap(ctl, bitmap);
+
+ return true;
+}
+
+static bool steal_from_bitmap_to_front(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info,
+ bool update_stat)
+{
+ struct btrfs_free_space *bitmap;
+ u64 bitmap_offset;
+ unsigned long i;
+ unsigned long j;
+ unsigned long prev_j;
+ u64 bytes;
+
+ bitmap_offset = offset_to_bitmap(ctl, info->offset);
+ /* If we're on a boundary, try the previous logical bitmap. */
+ if (bitmap_offset == info->offset) {
+ if (info->offset == 0)
+ return false;
+ bitmap_offset = offset_to_bitmap(ctl, info->offset - 1);
+ }
+
+ bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
+ if (!bitmap)
+ return false;
+
+ i = offset_to_bit(bitmap->offset, ctl->unit, info->offset) - 1;
+ j = 0;
+ prev_j = (unsigned long)-1;
+ for_each_clear_bit_from(j, bitmap->bitmap, BITS_PER_BITMAP) {
+ if (j > i)
+ break;
+ prev_j = j;
+ }
+ if (prev_j == i)
+ return false;
+
+ if (prev_j == (unsigned long)-1)
+ bytes = (i + 1) * ctl->unit;
+ else
+ bytes = (i - prev_j) * ctl->unit;
+
+ info->offset -= bytes;
+ info->bytes += bytes;
+
+ if (update_stat)
+ bitmap_clear_bits(ctl, bitmap, info->offset, bytes);
+ else
+ __bitmap_clear_bits(ctl, bitmap, info->offset, bytes);
+
+ if (!bitmap->bytes)
+ free_bitmap(ctl, bitmap);
+
+ return true;
+}
+
+/*
+ * We prefer always to allocate from extent entries, both for clustered and
+ * non-clustered allocation requests. So when attempting to add a new extent
+ * entry, try to see if there's adjacent free space in bitmap entries, and if
+ * there is, migrate that space from the bitmaps to the extent.
+ * Like this we get better chances of satisfying space allocation requests
+ * because we attempt to satisfy them based on a single cache entry, and never
+ * on 2 or more entries - even if the entries represent a contiguous free space
+ * region (e.g. 1 extent entry + 1 bitmap entry starting where the extent entry
+ * ends).
+ */
+static void steal_from_bitmap(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info,
+ bool update_stat)
+{
+ /*
+ * Only work with disconnected entries, as we can change their offset,
+ * and must be extent entries.
+ */
+ ASSERT(!info->bitmap);
+ ASSERT(RB_EMPTY_NODE(&info->offset_index));
+
+ if (ctl->total_bitmaps > 0) {
+ bool stole_end;
+ bool stole_front = false;
+
+ stole_end = steal_from_bitmap_to_end(ctl, info, update_stat);
+ if (ctl->total_bitmaps > 0)
+ stole_front = steal_from_bitmap_to_front(ctl, info,
+ update_stat);
+
+ if (stole_end || stole_front)
+ try_merge_free_space(ctl, info, update_stat);
+ }
+}
+
+int __btrfs_add_free_space(struct btrfs_fs_info *fs_info,
+ struct btrfs_free_space_ctl *ctl,
+ u64 offset, u64 bytes)
+{
+ struct btrfs_free_space *info;
+ int ret = 0;
+
+ info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
+ if (!info)
+ return -ENOMEM;
+
+ info->offset = offset;
+ info->bytes = bytes;
+ RB_CLEAR_NODE(&info->offset_index);
+
+ spin_lock(&ctl->tree_lock);
+
+ if (try_merge_free_space(ctl, info, true))
+ goto link;
+
+ /*
+ * There was no extent directly to the left or right of this new
+ * extent then we know we're going to have to allocate a new extent, so
+ * before we do that see if we need to drop this into a bitmap
+ */
+ ret = insert_into_bitmap(ctl, info);
+ if (ret < 0) {
+ goto out;
+ } else if (ret) {
+ ret = 0;
+ goto out;
+ }
+link:
+ /*
+ * Only steal free space from adjacent bitmaps if we're sure we're not
+ * going to add the new free space to existing bitmap entries - because
+ * that would mean unnecessary work that would be reverted. Therefore
+ * attempt to steal space from bitmaps if we're adding an extent entry.
+ */
+ steal_from_bitmap(ctl, info, true);
+
+ ret = link_free_space(ctl, info);
+ if (ret)
+ kmem_cache_free(btrfs_free_space_cachep, info);
+out:
+ spin_unlock(&ctl->tree_lock);
+
+ if (ret) {
+ btrfs_crit(fs_info, "unable to add free space :%d", ret);
+ ASSERT(ret != -EEXIST);
+ }
+
+ return ret;
+}
+
+int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
+ u64 offset, u64 bytes)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct btrfs_free_space *info;
+ int ret;
+ bool re_search = false;
+
+ spin_lock(&ctl->tree_lock);
+
+again:
+ ret = 0;
+ if (!bytes)
+ goto out_lock;
+
+ info = tree_search_offset(ctl, offset, 0, 0);
+ if (!info) {
+ /*
+ * oops didn't find an extent that matched the space we wanted
+ * to remove, look for a bitmap instead
+ */
+ info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
+ 1, 0);
+ if (!info) {
+ /*
+ * If we found a partial bit of our free space in a
+ * bitmap but then couldn't find the other part this may
+ * be a problem, so WARN about it.
+ */
+ WARN_ON(re_search);
+ goto out_lock;
+ }
+ }
+
+ re_search = false;
+ if (!info->bitmap) {
+ unlink_free_space(ctl, info);
+ if (offset == info->offset) {
+ u64 to_free = min(bytes, info->bytes);
+
+ info->bytes -= to_free;
+ info->offset += to_free;
+ if (info->bytes) {
+ ret = link_free_space(ctl, info);
+ WARN_ON(ret);
+ } else {
+ kmem_cache_free(btrfs_free_space_cachep, info);
+ }
+
+ offset += to_free;
+ bytes -= to_free;
+ goto again;
+ } else {
+ u64 old_end = info->bytes + info->offset;
+
+ info->bytes = offset - info->offset;
+ ret = link_free_space(ctl, info);
+ WARN_ON(ret);
+ if (ret)
+ goto out_lock;
+
+ /* Not enough bytes in this entry to satisfy us */
+ if (old_end < offset + bytes) {
+ bytes -= old_end - offset;
+ offset = old_end;
+ goto again;
+ } else if (old_end == offset + bytes) {
+ /* all done */
+ goto out_lock;
+ }
+ spin_unlock(&ctl->tree_lock);
+
+ ret = btrfs_add_free_space(block_group, offset + bytes,
+ old_end - (offset + bytes));
+ WARN_ON(ret);
+ goto out;
+ }
+ }
+
+ ret = remove_from_bitmap(ctl, info, &offset, &bytes);
+ if (ret == -EAGAIN) {
+ re_search = true;
+ goto again;
+ }
+out_lock:
+ spin_unlock(&ctl->tree_lock);
+out:
+ return ret;
+}
+
+void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group,
+ u64 bytes)
+{
+ struct btrfs_fs_info *fs_info = block_group->fs_info;
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct btrfs_free_space *info;
+ struct rb_node *n;
+ int count = 0;
+
+ spin_lock(&ctl->tree_lock);
+ for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
+ info = rb_entry(n, struct btrfs_free_space, offset_index);
+ if (info->bytes >= bytes && !block_group->ro)
+ count++;
+ btrfs_crit(fs_info, "entry offset %llu, bytes %llu, bitmap %s",
+ info->offset, info->bytes,
+ (info->bitmap) ? "yes" : "no");
+ }
+ spin_unlock(&ctl->tree_lock);
+ btrfs_info(fs_info, "block group has cluster?: %s",
+ list_empty(&block_group->cluster_list) ? "no" : "yes");
+ btrfs_info(fs_info,
+ "%d blocks of free space at or bigger than bytes is", count);
+}
+
+void btrfs_init_free_space_ctl(struct btrfs_block_group_cache *block_group)
+{
+ struct btrfs_fs_info *fs_info = block_group->fs_info;
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+
+ spin_lock_init(&ctl->tree_lock);
+ ctl->unit = fs_info->sectorsize;
+ ctl->start = block_group->key.objectid;
+ ctl->private = block_group;
+ ctl->op = &free_space_op;
+ INIT_LIST_HEAD(&ctl->trimming_ranges);
+ mutex_init(&ctl->cache_writeout_mutex);
+
+ /*
+ * we only want to have 32k of ram per block group for keeping
+ * track of free space, and if we pass 1/2 of that we want to
+ * start converting things over to using bitmaps
+ */
+ ctl->extents_thresh = (SZ_32K / 2) / sizeof(struct btrfs_free_space);
+}
+
+/*
+ * for a given cluster, put all of its extents back into the free
+ * space cache. If the block group passed doesn't match the block group
+ * pointed to by the cluster, someone else raced in and freed the
+ * cluster already. In that case, we just return without changing anything
+ */
+static int
+__btrfs_return_cluster_to_free_space(
+ struct btrfs_block_group_cache *block_group,
+ struct btrfs_free_cluster *cluster)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct btrfs_free_space *entry;
+ struct rb_node *node;
+
+ spin_lock(&cluster->lock);
+ if (cluster->block_group != block_group)
+ goto out;
+
+ cluster->block_group = NULL;
+ cluster->window_start = 0;
+ list_del_init(&cluster->block_group_list);
+
+ node = rb_first(&cluster->root);
+ while (node) {
+ bool bitmap;
+
+ entry = rb_entry(node, struct btrfs_free_space, offset_index);
+ node = rb_next(&entry->offset_index);
+ rb_erase(&entry->offset_index, &cluster->root);
+ RB_CLEAR_NODE(&entry->offset_index);
+
+ bitmap = (entry->bitmap != NULL);
+ if (!bitmap) {
+ try_merge_free_space(ctl, entry, false);
+ steal_from_bitmap(ctl, entry, false);
+ }
+ tree_insert_offset(&ctl->free_space_offset,
+ entry->offset, &entry->offset_index, bitmap);
+ }
+ cluster->root = RB_ROOT;
+
+out:
+ spin_unlock(&cluster->lock);
+ btrfs_put_block_group(block_group);
+ return 0;
+}
+
+static void __btrfs_remove_free_space_cache_locked(
+ struct btrfs_free_space_ctl *ctl)
+{
+ struct btrfs_free_space *info;
+ struct rb_node *node;
+
+ while ((node = rb_last(&ctl->free_space_offset)) != NULL) {
+ info = rb_entry(node, struct btrfs_free_space, offset_index);
+ if (!info->bitmap) {
+ unlink_free_space(ctl, info);
+ kmem_cache_free(btrfs_free_space_cachep, info);
+ } else {
+ free_bitmap(ctl, info);
+ }
+
+ cond_resched_lock(&ctl->tree_lock);
+ }
+}
+
+void __btrfs_remove_free_space_cache(struct btrfs_free_space_ctl *ctl)
+{
+ spin_lock(&ctl->tree_lock);
+ __btrfs_remove_free_space_cache_locked(ctl);
+ spin_unlock(&ctl->tree_lock);
+}
+
+void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct btrfs_free_cluster *cluster;
+ struct list_head *head;
+
+ spin_lock(&ctl->tree_lock);
+ while ((head = block_group->cluster_list.next) !=
+ &block_group->cluster_list) {
+ cluster = list_entry(head, struct btrfs_free_cluster,
+ block_group_list);
+
+ WARN_ON(cluster->block_group != block_group);
+ __btrfs_return_cluster_to_free_space(block_group, cluster);
+
+ cond_resched_lock(&ctl->tree_lock);
+ }
+ __btrfs_remove_free_space_cache_locked(ctl);
+ spin_unlock(&ctl->tree_lock);
+
+}
+
+u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
+ u64 offset, u64 bytes, u64 empty_size,
+ u64 *max_extent_size)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct btrfs_free_space *entry = NULL;
+ u64 bytes_search = bytes + empty_size;
+ u64 ret = 0;
+ u64 align_gap = 0;
+ u64 align_gap_len = 0;
+
+ spin_lock(&ctl->tree_lock);
+ entry = find_free_space(ctl, &offset, &bytes_search,
+ block_group->full_stripe_len, max_extent_size);
+ if (!entry)
+ goto out;
+
+ ret = offset;
+ if (entry->bitmap) {
+ bitmap_clear_bits(ctl, entry, offset, bytes);
+ if (!entry->bytes)
+ free_bitmap(ctl, entry);
+ } else {
+ unlink_free_space(ctl, entry);
+ align_gap_len = offset - entry->offset;
+ align_gap = entry->offset;
+
+ entry->offset = offset + bytes;
+ WARN_ON(entry->bytes < bytes + align_gap_len);
+
+ entry->bytes -= bytes + align_gap_len;
+ if (!entry->bytes)
+ kmem_cache_free(btrfs_free_space_cachep, entry);
+ else
+ link_free_space(ctl, entry);
+ }
+out:
+ spin_unlock(&ctl->tree_lock);
+
+ if (align_gap_len)
+ __btrfs_add_free_space(block_group->fs_info, ctl,
+ align_gap, align_gap_len);
+ return ret;
+}
+
+/*
+ * given a cluster, put all of its extents back into the free space
+ * cache. If a block group is passed, this function will only free
+ * a cluster that belongs to the passed block group.
+ *
+ * Otherwise, it'll get a reference on the block group pointed to by the
+ * cluster and remove the cluster from it.
+ */
+int btrfs_return_cluster_to_free_space(
+ struct btrfs_block_group_cache *block_group,
+ struct btrfs_free_cluster *cluster)
+{
+ struct btrfs_free_space_ctl *ctl;
+ int ret;
+
+ /* first, get a safe pointer to the block group */
+ spin_lock(&cluster->lock);
+ if (!block_group) {
+ block_group = cluster->block_group;
+ if (!block_group) {
+ spin_unlock(&cluster->lock);
+ return 0;
+ }
+ } else if (cluster->block_group != block_group) {
+ /* someone else has already freed it don't redo their work */
+ spin_unlock(&cluster->lock);
+ return 0;
+ }
+ atomic_inc(&block_group->count);
+ spin_unlock(&cluster->lock);
+
+ ctl = block_group->free_space_ctl;
+
+ /* now return any extents the cluster had on it */
+ spin_lock(&ctl->tree_lock);
+ ret = __btrfs_return_cluster_to_free_space(block_group, cluster);
+ spin_unlock(&ctl->tree_lock);
+
+ /* finally drop our ref */
+ btrfs_put_block_group(block_group);
+ return ret;
+}
+
+static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group,
+ struct btrfs_free_cluster *cluster,
+ struct btrfs_free_space *entry,
+ u64 bytes, u64 min_start,
+ u64 *max_extent_size)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ int err;
+ u64 search_start = cluster->window_start;
+ u64 search_bytes = bytes;
+ u64 ret = 0;
+
+ search_start = min_start;
+ search_bytes = bytes;
+
+ err = search_bitmap(ctl, entry, &search_start, &search_bytes, true);
+ if (err) {
+ *max_extent_size = max(get_max_extent_size(entry),
+ *max_extent_size);
+ return 0;
+ }
+
+ ret = search_start;
+ __bitmap_clear_bits(ctl, entry, ret, bytes);
+
+ return ret;
+}
+
+/*
+ * given a cluster, try to allocate 'bytes' from it, returns 0
+ * if it couldn't find anything suitably large, or a logical disk offset
+ * if things worked out
+ */
+u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
+ struct btrfs_free_cluster *cluster, u64 bytes,
+ u64 min_start, u64 *max_extent_size)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct btrfs_free_space *entry = NULL;
+ struct rb_node *node;
+ u64 ret = 0;
+
+ spin_lock(&cluster->lock);
+ if (bytes > cluster->max_size)
+ goto out;
+
+ if (cluster->block_group != block_group)
+ goto out;
+
+ node = rb_first(&cluster->root);
+ if (!node)
+ goto out;
+
+ entry = rb_entry(node, struct btrfs_free_space, offset_index);
+ while (1) {
+ if (entry->bytes < bytes)
+ *max_extent_size = max(get_max_extent_size(entry),
+ *max_extent_size);
+
+ if (entry->bytes < bytes ||
+ (!entry->bitmap && entry->offset < min_start)) {
+ node = rb_next(&entry->offset_index);
+ if (!node)
+ break;
+ entry = rb_entry(node, struct btrfs_free_space,
+ offset_index);
+ continue;
+ }
+
+ if (entry->bitmap) {
+ ret = btrfs_alloc_from_bitmap(block_group,
+ cluster, entry, bytes,
+ cluster->window_start,
+ max_extent_size);
+ if (ret == 0) {
+ node = rb_next(&entry->offset_index);
+ if (!node)
+ break;
+ entry = rb_entry(node, struct btrfs_free_space,
+ offset_index);
+ continue;
+ }
+ cluster->window_start += bytes;
+ } else {
+ ret = entry->offset;
+
+ entry->offset += bytes;
+ entry->bytes -= bytes;
+ }
+
+ if (entry->bytes == 0)
+ rb_erase(&entry->offset_index, &cluster->root);
+ break;
+ }
+out:
+ spin_unlock(&cluster->lock);
+
+ if (!ret)
+ return 0;
+
+ spin_lock(&ctl->tree_lock);
+
+ ctl->free_space -= bytes;
+ if (entry->bytes == 0) {
+ ctl->free_extents--;
+ if (entry->bitmap) {
+ kfree(entry->bitmap);
+ ctl->total_bitmaps--;
+ ctl->op->recalc_thresholds(ctl);
+ }
+ kmem_cache_free(btrfs_free_space_cachep, entry);
+ }
+
+ spin_unlock(&ctl->tree_lock);
+
+ return ret;
+}
+
+static int btrfs_bitmap_cluster(struct btrfs_block_group_cache *block_group,
+ struct btrfs_free_space *entry,
+ struct btrfs_free_cluster *cluster,
+ u64 offset, u64 bytes,
+ u64 cont1_bytes, u64 min_bytes)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ unsigned long next_zero;
+ unsigned long i;
+ unsigned long want_bits;
+ unsigned long min_bits;
+ unsigned long found_bits;
+ unsigned long max_bits = 0;
+ unsigned long start = 0;
+ unsigned long total_found = 0;
+ int ret;
+
+ i = offset_to_bit(entry->offset, ctl->unit,
+ max_t(u64, offset, entry->offset));
+ want_bits = bytes_to_bits(bytes, ctl->unit);
+ min_bits = bytes_to_bits(min_bytes, ctl->unit);
+
+ /*
+ * Don't bother looking for a cluster in this bitmap if it's heavily
+ * fragmented.
+ */
+ if (entry->max_extent_size &&
+ entry->max_extent_size < cont1_bytes)
+ return -ENOSPC;
+again:
+ found_bits = 0;
+ for_each_set_bit_from(i, entry->bitmap, BITS_PER_BITMAP) {
+ next_zero = find_next_zero_bit(entry->bitmap,
+ BITS_PER_BITMAP, i);
+ if (next_zero - i >= min_bits) {
+ found_bits = next_zero - i;
+ if (found_bits > max_bits)
+ max_bits = found_bits;
+ break;
+ }
+ if (next_zero - i > max_bits)
+ max_bits = next_zero - i;
+ i = next_zero;
+ }
+
+ if (!found_bits) {
+ entry->max_extent_size = (u64)max_bits * ctl->unit;
+ return -ENOSPC;
+ }
+
+ if (!total_found) {
+ start = i;
+ cluster->max_size = 0;
+ }
+
+ total_found += found_bits;
+
+ if (cluster->max_size < found_bits * ctl->unit)
+ cluster->max_size = found_bits * ctl->unit;
+
+ if (total_found < want_bits || cluster->max_size < cont1_bytes) {
+ i = next_zero + 1;
+ goto again;
+ }
+
+ cluster->window_start = start * ctl->unit + entry->offset;
+ rb_erase(&entry->offset_index, &ctl->free_space_offset);
+ ret = tree_insert_offset(&cluster->root, entry->offset,
+ &entry->offset_index, 1);
+ ASSERT(!ret); /* -EEXIST; Logic error */
+
+ trace_btrfs_setup_cluster(block_group, cluster,
+ total_found * ctl->unit, 1);
+ return 0;
+}
+
+/*
+ * This searches the block group for just extents to fill the cluster with.
+ * Try to find a cluster with at least bytes total bytes, at least one
+ * extent of cont1_bytes, and other clusters of at least min_bytes.
+ */
+static noinline int
+setup_cluster_no_bitmap(struct btrfs_block_group_cache *block_group,
+ struct btrfs_free_cluster *cluster,
+ struct list_head *bitmaps, u64 offset, u64 bytes,
+ u64 cont1_bytes, u64 min_bytes)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct btrfs_free_space *first = NULL;
+ struct btrfs_free_space *entry = NULL;
+ struct btrfs_free_space *last;
+ struct rb_node *node;
+ u64 window_free;
+ u64 max_extent;
+ u64 total_size = 0;
+
+ entry = tree_search_offset(ctl, offset, 0, 1);
+ if (!entry)
+ return -ENOSPC;
+
+ /*
+ * We don't want bitmaps, so just move along until we find a normal
+ * extent entry.
+ */
+ while (entry->bitmap || entry->bytes < min_bytes) {
+ if (entry->bitmap && list_empty(&entry->list))
+ list_add_tail(&entry->list, bitmaps);
+ node = rb_next(&entry->offset_index);
+ if (!node)
+ return -ENOSPC;
+ entry = rb_entry(node, struct btrfs_free_space, offset_index);
+ }
+
+ window_free = entry->bytes;
+ max_extent = entry->bytes;
+ first = entry;
+ last = entry;
+
+ for (node = rb_next(&entry->offset_index); node;
+ node = rb_next(&entry->offset_index)) {
+ entry = rb_entry(node, struct btrfs_free_space, offset_index);
+
+ if (entry->bitmap) {
+ if (list_empty(&entry->list))
+ list_add_tail(&entry->list, bitmaps);
+ continue;
+ }
+
+ if (entry->bytes < min_bytes)
+ continue;
+
+ last = entry;
+ window_free += entry->bytes;
+ if (entry->bytes > max_extent)
+ max_extent = entry->bytes;
+ }
+
+ if (window_free < bytes || max_extent < cont1_bytes)
+ return -ENOSPC;
+
+ cluster->window_start = first->offset;
+
+ node = &first->offset_index;
+
+ /*
+ * now we've found our entries, pull them out of the free space
+ * cache and put them into the cluster rbtree
+ */
+ do {
+ int ret;
+
+ entry = rb_entry(node, struct btrfs_free_space, offset_index);
+ node = rb_next(&entry->offset_index);
+ if (entry->bitmap || entry->bytes < min_bytes)
+ continue;
+
+ rb_erase(&entry->offset_index, &ctl->free_space_offset);
+ ret = tree_insert_offset(&cluster->root, entry->offset,
+ &entry->offset_index, 0);
+ total_size += entry->bytes;
+ ASSERT(!ret); /* -EEXIST; Logic error */
+ } while (node && entry != last);
+
+ cluster->max_size = max_extent;
+ trace_btrfs_setup_cluster(block_group, cluster, total_size, 0);
+ return 0;
+}
+
+/*
+ * This specifically looks for bitmaps that may work in the cluster, we assume
+ * that we have already failed to find extents that will work.
+ */
+static noinline int
+setup_cluster_bitmap(struct btrfs_block_group_cache *block_group,
+ struct btrfs_free_cluster *cluster,
+ struct list_head *bitmaps, u64 offset, u64 bytes,
+ u64 cont1_bytes, u64 min_bytes)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct btrfs_free_space *entry = NULL;
+ int ret = -ENOSPC;
+ u64 bitmap_offset = offset_to_bitmap(ctl, offset);
+
+ if (ctl->total_bitmaps == 0)
+ return -ENOSPC;
+
+ /*
+ * The bitmap that covers offset won't be in the list unless offset
+ * is just its start offset.
+ */
+ if (!list_empty(bitmaps))
+ entry = list_first_entry(bitmaps, struct btrfs_free_space, list);
+
+ if (!entry || entry->offset != bitmap_offset) {
+ entry = tree_search_offset(ctl, bitmap_offset, 1, 0);
+ if (entry && list_empty(&entry->list))
+ list_add(&entry->list, bitmaps);
+ }
+
+ list_for_each_entry(entry, bitmaps, list) {
+ if (entry->bytes < bytes)
+ continue;
+ ret = btrfs_bitmap_cluster(block_group, entry, cluster, offset,
+ bytes, cont1_bytes, min_bytes);
+ if (!ret)
+ return 0;
+ }
+
+ /*
+ * The bitmaps list has all the bitmaps that record free space
+ * starting after offset, so no more search is required.
+ */
+ return -ENOSPC;
+}
+
+/*
+ * here we try to find a cluster of blocks in a block group. The goal
+ * is to find at least bytes+empty_size.
+ * We might not find them all in one contiguous area.
+ *
+ * returns zero and sets up cluster if things worked out, otherwise
+ * it returns -enospc
+ */
+int btrfs_find_space_cluster(struct btrfs_fs_info *fs_info,
+ struct btrfs_block_group_cache *block_group,
+ struct btrfs_free_cluster *cluster,
+ u64 offset, u64 bytes, u64 empty_size)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct btrfs_free_space *entry, *tmp;
+ LIST_HEAD(bitmaps);
+ u64 min_bytes;
+ u64 cont1_bytes;
+ int ret;
+
+ /*
+ * Choose the minimum extent size we'll require for this
+ * cluster. For SSD_SPREAD, don't allow any fragmentation.
+ * For metadata, allow allocates with smaller extents. For
+ * data, keep it dense.
+ */
+ if (btrfs_test_opt(fs_info, SSD_SPREAD)) {
+ cont1_bytes = min_bytes = bytes + empty_size;
+ } else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) {
+ cont1_bytes = bytes;
+ min_bytes = fs_info->sectorsize;
+ } else {
+ cont1_bytes = max(bytes, (bytes + empty_size) >> 2);
+ min_bytes = fs_info->sectorsize;
+ }
+
+ spin_lock(&ctl->tree_lock);
+
+ /*
+ * If we know we don't have enough space to make a cluster don't even
+ * bother doing all the work to try and find one.
+ */
+ if (ctl->free_space < bytes) {
+ spin_unlock(&ctl->tree_lock);
+ return -ENOSPC;
+ }
+
+ spin_lock(&cluster->lock);
+
+ /* someone already found a cluster, hooray */
+ if (cluster->block_group) {
+ ret = 0;
+ goto out;
+ }
+
+ trace_btrfs_find_cluster(block_group, offset, bytes, empty_size,
+ min_bytes);
+
+ ret = setup_cluster_no_bitmap(block_group, cluster, &bitmaps, offset,
+ bytes + empty_size,
+ cont1_bytes, min_bytes);
+ if (ret)
+ ret = setup_cluster_bitmap(block_group, cluster, &bitmaps,
+ offset, bytes + empty_size,
+ cont1_bytes, min_bytes);
+
+ /* Clear our temporary list */
+ list_for_each_entry_safe(entry, tmp, &bitmaps, list)
+ list_del_init(&entry->list);
+
+ if (!ret) {
+ atomic_inc(&block_group->count);
+ list_add_tail(&cluster->block_group_list,
+ &block_group->cluster_list);
+ cluster->block_group = block_group;
+ } else {
+ trace_btrfs_failed_cluster_setup(block_group);
+ }
+out:
+ spin_unlock(&cluster->lock);
+ spin_unlock(&ctl->tree_lock);
+
+ return ret;
+}
+
+/*
+ * simple code to zero out a cluster
+ */
+void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster)
+{
+ spin_lock_init(&cluster->lock);
+ spin_lock_init(&cluster->refill_lock);
+ cluster->root = RB_ROOT;
+ cluster->max_size = 0;
+ cluster->fragmented = false;
+ INIT_LIST_HEAD(&cluster->block_group_list);
+ cluster->block_group = NULL;
+}
+
+static int do_trimming(struct btrfs_block_group_cache *block_group,
+ u64 *total_trimmed, u64 start, u64 bytes,
+ u64 reserved_start, u64 reserved_bytes,
+ struct btrfs_trim_range *trim_entry)
+{
+ struct btrfs_space_info *space_info = block_group->space_info;
+ struct btrfs_fs_info *fs_info = block_group->fs_info;
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ int ret;
+ int update = 0;
+ u64 trimmed = 0;
+
+ spin_lock(&space_info->lock);
+ spin_lock(&block_group->lock);
+ if (!block_group->ro) {
+ block_group->reserved += reserved_bytes;
+ space_info->bytes_reserved += reserved_bytes;
+ update = 1;
+ }
+ spin_unlock(&block_group->lock);
+ spin_unlock(&space_info->lock);
+
+ ret = btrfs_discard_extent(fs_info, start, bytes, &trimmed);
+ if (!ret)
+ *total_trimmed += trimmed;
+
+ mutex_lock(&ctl->cache_writeout_mutex);
+ btrfs_add_free_space(block_group, reserved_start, reserved_bytes);
+ list_del(&trim_entry->list);
+ mutex_unlock(&ctl->cache_writeout_mutex);
+
+ if (update) {
+ spin_lock(&space_info->lock);
+ spin_lock(&block_group->lock);
+ if (block_group->ro)
+ space_info->bytes_readonly += reserved_bytes;
+ block_group->reserved -= reserved_bytes;
+ space_info->bytes_reserved -= reserved_bytes;
+ spin_unlock(&space_info->lock);
+ spin_unlock(&block_group->lock);
+ }
+
+ return ret;
+}
+
+static int trim_no_bitmap(struct btrfs_block_group_cache *block_group,
+ u64 *total_trimmed, u64 start, u64 end, u64 minlen)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct btrfs_free_space *entry;
+ struct rb_node *node;
+ int ret = 0;
+ u64 extent_start;
+ u64 extent_bytes;
+ u64 bytes;
+
+ while (start < end) {
+ struct btrfs_trim_range trim_entry;
+
+ mutex_lock(&ctl->cache_writeout_mutex);
+ spin_lock(&ctl->tree_lock);
+
+ if (ctl->free_space < minlen) {
+ spin_unlock(&ctl->tree_lock);
+ mutex_unlock(&ctl->cache_writeout_mutex);
+ break;
+ }
+
+ entry = tree_search_offset(ctl, start, 0, 1);
+ if (!entry) {
+ spin_unlock(&ctl->tree_lock);
+ mutex_unlock(&ctl->cache_writeout_mutex);
+ break;
+ }
+
+ /* skip bitmaps */
+ while (entry->bitmap) {
+ node = rb_next(&entry->offset_index);
+ if (!node) {
+ spin_unlock(&ctl->tree_lock);
+ mutex_unlock(&ctl->cache_writeout_mutex);
+ goto out;
+ }
+ entry = rb_entry(node, struct btrfs_free_space,
+ offset_index);
+ }
+
+ if (entry->offset >= end) {
+ spin_unlock(&ctl->tree_lock);
+ mutex_unlock(&ctl->cache_writeout_mutex);
+ break;
+ }
+
+ extent_start = entry->offset;
+ extent_bytes = entry->bytes;
+ start = max(start, extent_start);
+ bytes = min(extent_start + extent_bytes, end) - start;
+ if (bytes < minlen) {
+ spin_unlock(&ctl->tree_lock);
+ mutex_unlock(&ctl->cache_writeout_mutex);
+ goto next;
+ }
+
+ unlink_free_space(ctl, entry);
+ kmem_cache_free(btrfs_free_space_cachep, entry);
+
+ spin_unlock(&ctl->tree_lock);
+ trim_entry.start = extent_start;
+ trim_entry.bytes = extent_bytes;
+ list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
+ mutex_unlock(&ctl->cache_writeout_mutex);
+
+ ret = do_trimming(block_group, total_trimmed, start, bytes,
+ extent_start, extent_bytes, &trim_entry);
+ if (ret)
+ break;
+next:
+ start += bytes;
+
+ if (fatal_signal_pending(current)) {
+ ret = -ERESTARTSYS;
+ break;
+ }
+
+ cond_resched();
+ }
+out:
+ return ret;
+}
+
+static int trim_bitmaps(struct btrfs_block_group_cache *block_group,
+ u64 *total_trimmed, u64 start, u64 end, u64 minlen)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct btrfs_free_space *entry;
+ int ret = 0;
+ int ret2;
+ u64 bytes;
+ u64 offset = offset_to_bitmap(ctl, start);
+
+ while (offset < end) {
+ bool next_bitmap = false;
+ struct btrfs_trim_range trim_entry;
+
+ mutex_lock(&ctl->cache_writeout_mutex);
+ spin_lock(&ctl->tree_lock);
+
+ if (ctl->free_space < minlen) {
+ spin_unlock(&ctl->tree_lock);
+ mutex_unlock(&ctl->cache_writeout_mutex);
+ break;
+ }
+
+ entry = tree_search_offset(ctl, offset, 1, 0);
+ if (!entry) {
+ spin_unlock(&ctl->tree_lock);
+ mutex_unlock(&ctl->cache_writeout_mutex);
+ next_bitmap = true;
+ goto next;
+ }
+
+ bytes = minlen;
+ ret2 = search_bitmap(ctl, entry, &start, &bytes, false);
+ if (ret2 || start >= end) {
+ spin_unlock(&ctl->tree_lock);
+ mutex_unlock(&ctl->cache_writeout_mutex);
+ next_bitmap = true;
+ goto next;
+ }
+
+ bytes = min(bytes, end - start);
+ if (bytes < minlen) {
+ spin_unlock(&ctl->tree_lock);
+ mutex_unlock(&ctl->cache_writeout_mutex);
+ goto next;
+ }
+
+ bitmap_clear_bits(ctl, entry, start, bytes);
+ if (entry->bytes == 0)
+ free_bitmap(ctl, entry);
+
+ spin_unlock(&ctl->tree_lock);
+ trim_entry.start = start;
+ trim_entry.bytes = bytes;
+ list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
+ mutex_unlock(&ctl->cache_writeout_mutex);
+
+ ret = do_trimming(block_group, total_trimmed, start, bytes,
+ start, bytes, &trim_entry);
+ if (ret)
+ break;
+next:
+ if (next_bitmap) {
+ offset += BITS_PER_BITMAP * ctl->unit;
+ } else {
+ start += bytes;
+ if (start >= offset + BITS_PER_BITMAP * ctl->unit)
+ offset += BITS_PER_BITMAP * ctl->unit;
+ }
+
+ if (fatal_signal_pending(current)) {
+ ret = -ERESTARTSYS;
+ break;
+ }
+
+ cond_resched();
+ }
+
+ return ret;
+}
+
+void btrfs_get_block_group_trimming(struct btrfs_block_group_cache *cache)
+{
+ atomic_inc(&cache->trimming);
+}
+
+void btrfs_put_block_group_trimming(struct btrfs_block_group_cache *block_group)
+{
+ struct btrfs_fs_info *fs_info = block_group->fs_info;
+ struct extent_map_tree *em_tree;
+ struct extent_map *em;
+ bool cleanup;
+
+ spin_lock(&block_group->lock);
+ cleanup = (atomic_dec_and_test(&block_group->trimming) &&
+ block_group->removed);
+ spin_unlock(&block_group->lock);
+
+ if (cleanup) {
+ mutex_lock(&fs_info->chunk_mutex);
+ em_tree = &fs_info->mapping_tree.map_tree;
+ write_lock(&em_tree->lock);
+ em = lookup_extent_mapping(em_tree, block_group->key.objectid,
+ 1);
+ BUG_ON(!em); /* logic error, can't happen */
+ /*
+ * remove_extent_mapping() will delete us from the pinned_chunks
+ * list, which is protected by the chunk mutex.
+ */
+ remove_extent_mapping(em_tree, em);
+ write_unlock(&em_tree->lock);
+ mutex_unlock(&fs_info->chunk_mutex);
+
+ /* once for us and once for the tree */
+ free_extent_map(em);
+ free_extent_map(em);
+
+ /*
+ * We've left one free space entry and other tasks trimming
+ * this block group have left 1 entry each one. Free them.
+ */
+ __btrfs_remove_free_space_cache(block_group->free_space_ctl);
+ }
+}
+
+int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
+ u64 *trimmed, u64 start, u64 end, u64 minlen)
+{
+ int ret;
+
+ *trimmed = 0;
+
+ spin_lock(&block_group->lock);
+ if (block_group->removed) {
+ spin_unlock(&block_group->lock);
+ return 0;
+ }
+ btrfs_get_block_group_trimming(block_group);
+ spin_unlock(&block_group->lock);
+
+ ret = trim_no_bitmap(block_group, trimmed, start, end, minlen);
+ if (ret)
+ goto out;
+
+ ret = trim_bitmaps(block_group, trimmed, start, end, minlen);
+out:
+ btrfs_put_block_group_trimming(block_group);
+ return ret;
+}
+
+/*
+ * Find the left-most item in the cache tree, and then return the
+ * smallest inode number in the item.
+ *
+ * Note: the returned inode number may not be the smallest one in
+ * the tree, if the left-most item is a bitmap.
+ */
+u64 btrfs_find_ino_for_alloc(struct btrfs_root *fs_root)
+{
+ struct btrfs_free_space_ctl *ctl = fs_root->free_ino_ctl;
+ struct btrfs_free_space *entry = NULL;
+ u64 ino = 0;
+
+ spin_lock(&ctl->tree_lock);
+
+ if (RB_EMPTY_ROOT(&ctl->free_space_offset))
+ goto out;
+
+ entry = rb_entry(rb_first(&ctl->free_space_offset),
+ struct btrfs_free_space, offset_index);
+
+ if (!entry->bitmap) {
+ ino = entry->offset;
+
+ unlink_free_space(ctl, entry);
+ entry->offset++;
+ entry->bytes--;
+ if (!entry->bytes)
+ kmem_cache_free(btrfs_free_space_cachep, entry);
+ else
+ link_free_space(ctl, entry);
+ } else {
+ u64 offset = 0;
+ u64 count = 1;
+ int ret;
+
+ ret = search_bitmap(ctl, entry, &offset, &count, true);
+ /* Logic error; Should be empty if it can't find anything */
+ ASSERT(!ret);
+
+ ino = offset;
+ bitmap_clear_bits(ctl, entry, offset, 1);
+ if (entry->bytes == 0)
+ free_bitmap(ctl, entry);
+ }
+out:
+ spin_unlock(&ctl->tree_lock);
+
+ return ino;
+}
+
+struct inode *lookup_free_ino_inode(struct btrfs_root *root,
+ struct btrfs_path *path)
+{
+ struct inode *inode = NULL;
+
+ spin_lock(&root->ino_cache_lock);
+ if (root->ino_cache_inode)
+ inode = igrab(root->ino_cache_inode);
+ spin_unlock(&root->ino_cache_lock);
+ if (inode)
+ return inode;
+
+ inode = __lookup_free_space_inode(root, path, 0);
+ if (IS_ERR(inode))
+ return inode;
+
+ spin_lock(&root->ino_cache_lock);
+ if (!btrfs_fs_closing(root->fs_info))
+ root->ino_cache_inode = igrab(inode);
+ spin_unlock(&root->ino_cache_lock);
+
+ return inode;
+}
+
+int create_free_ino_inode(struct btrfs_root *root,
+ struct btrfs_trans_handle *trans,
+ struct btrfs_path *path)
+{
+ return __create_free_space_inode(root, trans, path,
+ BTRFS_FREE_INO_OBJECTID, 0);
+}
+
+int load_free_ino_cache(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
+{
+ struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
+ struct btrfs_path *path;
+ struct inode *inode;
+ int ret = 0;
+ u64 root_gen = btrfs_root_generation(&root->root_item);
+
+ if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
+ return 0;
+
+ /*
+ * If we're unmounting then just return, since this does a search on the
+ * normal root and not the commit root and we could deadlock.
+ */
+ if (btrfs_fs_closing(fs_info))
+ return 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return 0;
+
+ inode = lookup_free_ino_inode(root, path);
+ if (IS_ERR(inode))
+ goto out;
+
+ if (root_gen != BTRFS_I(inode)->generation)
+ goto out_put;
+
+ ret = __load_free_space_cache(root, inode, ctl, path, 0);
+
+ if (ret < 0)
+ btrfs_err(fs_info,
+ "failed to load free ino cache for root %llu",
+ root->root_key.objectid);
+out_put:
+ iput(inode);
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_write_out_ino_cache(struct btrfs_root *root,
+ struct btrfs_trans_handle *trans,
+ struct btrfs_path *path,
+ struct inode *inode)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
+ int ret;
+ struct btrfs_io_ctl io_ctl;
+ bool release_metadata = true;
+
+ if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
+ return 0;
+
+ memset(&io_ctl, 0, sizeof(io_ctl));
+ ret = __btrfs_write_out_cache(root, inode, ctl, NULL, &io_ctl, trans);
+ if (!ret) {
+ /*
+ * At this point writepages() didn't error out, so our metadata
+ * reservation is released when the writeback finishes, at
+ * inode.c:btrfs_finish_ordered_io(), regardless of it finishing
+ * with or without an error.
+ */
+ release_metadata = false;
+ ret = btrfs_wait_cache_io_root(root, trans, &io_ctl, path);
+ }
+
+ if (ret) {
+ if (release_metadata)
+ btrfs_delalloc_release_metadata(BTRFS_I(inode),
+ inode->i_size, true);
+#ifdef DEBUG
+ btrfs_err(fs_info,
+ "failed to write free ino cache for root %llu",
+ root->root_key.objectid);
+#endif
+ }
+
+ return ret;
+}
+
+#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
+/*
+ * Use this if you need to make a bitmap or extent entry specifically, it
+ * doesn't do any of the merging that add_free_space does, this acts a lot like
+ * how the free space cache loading stuff works, so you can get really weird
+ * configurations.
+ */
+int test_add_free_space_entry(struct btrfs_block_group_cache *cache,
+ u64 offset, u64 bytes, bool bitmap)
+{
+ struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
+ struct btrfs_free_space *info = NULL, *bitmap_info;
+ void *map = NULL;
+ u64 bytes_added;
+ int ret;
+
+again:
+ if (!info) {
+ info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
+ if (!info)
+ return -ENOMEM;
+ }
+
+ if (!bitmap) {
+ spin_lock(&ctl->tree_lock);
+ info->offset = offset;
+ info->bytes = bytes;
+ info->max_extent_size = 0;
+ ret = link_free_space(ctl, info);
+ spin_unlock(&ctl->tree_lock);
+ if (ret)
+ kmem_cache_free(btrfs_free_space_cachep, info);
+ return ret;
+ }
+
+ if (!map) {
+ map = kzalloc(PAGE_SIZE, GFP_NOFS);
+ if (!map) {
+ kmem_cache_free(btrfs_free_space_cachep, info);
+ return -ENOMEM;
+ }
+ }
+
+ spin_lock(&ctl->tree_lock);
+ bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
+ 1, 0);
+ if (!bitmap_info) {
+ info->bitmap = map;
+ map = NULL;
+ add_new_bitmap(ctl, info, offset);
+ bitmap_info = info;
+ info = NULL;
+ }
+
+ bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes);
+
+ bytes -= bytes_added;
+ offset += bytes_added;
+ spin_unlock(&ctl->tree_lock);
+
+ if (bytes)
+ goto again;
+
+ if (info)
+ kmem_cache_free(btrfs_free_space_cachep, info);
+ if (map)
+ kfree(map);
+ return 0;
+}
+
+/*
+ * Checks to see if the given range is in the free space cache. This is really
+ * just used to check the absence of space, so if there is free space in the
+ * range at all we will return 1.
+ */
+int test_check_exists(struct btrfs_block_group_cache *cache,
+ u64 offset, u64 bytes)
+{
+ struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
+ struct btrfs_free_space *info;
+ int ret = 0;
+
+ spin_lock(&ctl->tree_lock);
+ info = tree_search_offset(ctl, offset, 0, 0);
+ if (!info) {
+ info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
+ 1, 0);
+ if (!info)
+ goto out;
+ }
+
+have_info:
+ if (info->bitmap) {
+ u64 bit_off, bit_bytes;
+ struct rb_node *n;
+ struct btrfs_free_space *tmp;
+
+ bit_off = offset;
+ bit_bytes = ctl->unit;
+ ret = search_bitmap(ctl, info, &bit_off, &bit_bytes, false);
+ if (!ret) {
+ if (bit_off == offset) {
+ ret = 1;
+ goto out;
+ } else if (bit_off > offset &&
+ offset + bytes > bit_off) {
+ ret = 1;
+ goto out;
+ }
+ }
+
+ n = rb_prev(&info->offset_index);
+ while (n) {
+ tmp = rb_entry(n, struct btrfs_free_space,
+ offset_index);
+ if (tmp->offset + tmp->bytes < offset)
+ break;
+ if (offset + bytes < tmp->offset) {
+ n = rb_prev(&tmp->offset_index);
+ continue;
+ }
+ info = tmp;
+ goto have_info;
+ }
+
+ n = rb_next(&info->offset_index);
+ while (n) {
+ tmp = rb_entry(n, struct btrfs_free_space,
+ offset_index);
+ if (offset + bytes < tmp->offset)
+ break;
+ if (tmp->offset + tmp->bytes < offset) {
+ n = rb_next(&tmp->offset_index);
+ continue;
+ }
+ info = tmp;
+ goto have_info;
+ }
+
+ ret = 0;
+ goto out;
+ }
+
+ if (info->offset == offset) {
+ ret = 1;
+ goto out;
+ }
+
+ if (offset > info->offset && offset < info->offset + info->bytes)
+ ret = 1;
+out:
+ spin_unlock(&ctl->tree_lock);
+ return ret;
+}
+#endif /* CONFIG_BTRFS_FS_RUN_SANITY_TESTS */