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| author |   Dennis Zhou <dennis@kernel.org> | 2020-01-02 16:26:45 -0500 |
|---|---|---|
| committer |   David Sterba <dsterba@suse.com> | 2020-01-20 16:41:01 +0100 |
| commit | 27f0afc7376bf6e1405ee3a0ef0ab85171059ae8 (patch) | |
| tree | ba463d971d6924219069694774648100583fe3f6 /fs/btrfs | |
| parent | btrfs: make smaller extents more likely to go into bitmaps (diff) | |
| download | linux-dev-27f0afc7376bf6e1405ee3a0ef0ab85171059ae8.tar.xz linux-dev-27f0afc7376bf6e1405ee3a0ef0ab85171059ae8.zip | |
btrfs: ensure removal of discardable_* in free_bitmap()
Most callers of free_bitmap() only call it if bitmap_info->bytes is 0.
However, there are certain cases where we may free the free space cache
via __btrfs_remove_free_space_cache(). This exposes a path where
free_bitmap() is called regardless. This may result in a bad accounting
situation for discardable_bytes and discardable_extents. So, remove the
stats and call btrfs_discard_update_discardable().
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs')
| -rw-r--r-- | fs/btrfs/free-space-cache.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c index 30e010852040..0598fd3c6e3f 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -1959,6 +1959,18 @@ static void add_new_bitmap(struct btrfs_free_space_ctl *ctl, static void free_bitmap(struct btrfs_free_space_ctl *ctl, struct btrfs_free_space *bitmap_info) { + /* + * Normally when this is called, the bitmap is completely empty. However, + * if we are blowing up the free space cache for one reason or another + * via __btrfs_remove_free_space_cache(), then it may not be freed and + * we may leave stats on the table. + */ + if (bitmap_info->bytes && !btrfs_free_space_trimmed(bitmap_info)) { + ctl->discardable_extents[BTRFS_STAT_CURR] -= + bitmap_info->bitmap_extents; + ctl->discardable_bytes[BTRFS_STAT_CURR] -= bitmap_info->bytes; + + } unlink_free_space(ctl, bitmap_info); kmem_cache_free(btrfs_free_space_bitmap_cachep, bitmap_info->bitmap); kmem_cache_free(btrfs_free_space_cachep, bitmap_info); @@ -2776,6 +2788,8 @@ void __btrfs_remove_free_space_cache(struct btrfs_free_space_ctl *ctl) { spin_lock(&ctl->tree_lock); __btrfs_remove_free_space_cache_locked(ctl); + if (ctl->private) + btrfs_discard_update_discardable(ctl->private, ctl); spin_unlock(&ctl->tree_lock); } |