diff options
| author | Kent Overstreet <kent.overstreet@linux.dev> | 2024-06-17 10:06:03 -0400 |
|---|---|---|
| committer | Kent Overstreet <kent.overstreet@linux.dev> | 2024-06-19 18:27:24 -0400 |
| commit | cff07e2739d81cf33eb2a378a6136eced852b8cb (patch) | |
| tree | 16d13ed597b1558a6eeb6bd686acda0199d7f190 /fs/bcachefs/alloc_background.h | |
| parent | 1ba44217f8258f92c56644ca4fad4462f1941e33 (diff) | |
bcachefs: Guard against overflowing LRU_TIME_BITS
LRUs only have 48 bits for the time field (i.e. LRU order); thus we need
overflow checks and guards.
Reported-by: syzbot+df3bf3f088dcaa728857@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Diffstat (limited to 'fs/bcachefs/alloc_background.h')
| -rw-r--r-- | fs/bcachefs/alloc_background.h | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/fs/bcachefs/alloc_background.h b/fs/bcachefs/alloc_background.h index ae31a94be6f9..c3cc3c5ba5b6 100644 --- a/fs/bcachefs/alloc_background.h +++ b/fs/bcachefs/alloc_background.h @@ -141,7 +141,13 @@ static inline u64 alloc_lru_idx_fragmentation(struct bch_alloc_v4 a, !bch2_bucket_sectors_fragmented(ca, a)) return 0; - u64 d = bch2_bucket_sectors_dirty(a); + /* + * avoid overflowing LRU_TIME_BITS on a corrupted fs, when + * bucket_sectors_dirty is (much) bigger than bucket_size + */ + u64 d = min(bch2_bucket_sectors_dirty(a), + ca->mi.bucket_size); + return div_u64(d * (1ULL << 31), ca->mi.bucket_size); } |