2023-10-31 12:49:56

by Anastasia Belova

Subject: [PATCH 5.10 0/1] btrfs: fix region size in count_bitmap_extents

Function count_bitmap_extents was deleted in version
5.11, but there is typo in versions 5.6-5.10. The
following patch may fix it.

2023-10-31 12:50:08

by Anastasia Belova

Subject: [PATCH 5.10 1/1] btrfs: fix region size in count_bitmap_extents

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 <[email protected]>
---
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)
--
2.30.2