diff options
| author | Alan Huang <mmpgouride@gmail.com> | 2025-01-27 17:12:41 +0800 |
|---|---|---|
| committer | Kent Overstreet <kent.overstreet@linux.dev> | 2025-03-14 21:02:12 -0400 |
| commit | 7d8321a286de288778e175ea5b967dceaeed9c96 (patch) | |
| tree | c3fc8fd1e5521e4f5414c3101cb1698574354b8e /fs/bcachefs/snapshot.c | |
| parent | bcachefs: Scrub (diff) | |
| download | linux-7d8321a286de288778e175ea5b967dceaeed9c96.tar.gz linux-7d8321a286de288778e175ea5b967dceaeed9c96.zip | |
bcachefs: Fix subtraction underflow
When ancestor is less than IS_ANCESTOR_BITMAP, we would get an incorrect
result.
Signed-off-by: Alan Huang <mmpgouride@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Diffstat (limited to 'fs/bcachefs/snapshot.c')
| -rw-r--r-- | fs/bcachefs/snapshot.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/bcachefs/snapshot.c b/fs/bcachefs/snapshot.c index c54091a28909..ede0b480e7d4 100644 --- a/fs/bcachefs/snapshot.c +++ b/fs/bcachefs/snapshot.c @@ -146,8 +146,9 @@ bool __bch2_snapshot_is_ancestor(struct bch_fs *c, u32 id, u32 ancestor) goto out; } - while (id && id < ancestor - IS_ANCESTOR_BITMAP) - id = get_ancestor_below(t, id, ancestor); + if (likely(ancestor >= IS_ANCESTOR_BITMAP)) + while (id && id < ancestor - IS_ANCESTOR_BITMAP) + id = get_ancestor_below(t, id, ancestor); ret = id && id < ancestor ? test_ancestor_bitmap(t, id, ancestor) |