count_bitmap_extents was deleted in version 5.11, but there is possible mistake in versions 5.6-5.10.

Region size should be calculated by subtracting the end from the beginning.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: dfb79ddb130e ("btrfs: track discardable extents for async discard") Signed-off-by: Anastasia Belova abelova@astralinux.ru --- fs/btrfs/free-space-cache.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c index 4989c60b1df9..a34e266a0969 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -1930,7 +1930,7 @@ static int count_bitmap_extents(struct btrfs_free_space_ctl *ctl,

bitmap_for_each_set_region(bitmap_info->bitmap, rs, re, 0, BITS_PER_BITMAP) { - bytes -= (rs - re) * ctl->unit; + bytes -= (re - rs) * ctl->unit; count++;

if (!bytes)