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| author | Kent Overstreet <kent.overstreet@linux.dev> | 2024-04-04 22:50:26 +0300 |
|---|---|---|
| committer | Kent Overstreet <kent.overstreet@linux.dev> | 2024-04-04 23:52:42 +0300 |
| commit | 01e5f4fc0fead3ef19000e1d2fc748e87aac3f02 (patch) | |
| tree | 98981c9c62272fe4af81bfd44ad3d066c0914ce5 /fs/bcachefs/snapshot.c | |
| parent | e60aa472400b1ff8d0e6c563a2eb05916927f10a (diff) | |
| download | linux-01e5f4fc0fead3ef19000e1d2fc748e87aac3f02.tar.xz | |
bcachefs: Make snapshot_is_ancestor() safe
Snapshot table accesses generally need to be checking for invalid
snapshot ID now, fix one that was missed.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Diffstat (limited to 'fs/bcachefs/snapshot.c')
| -rw-r--r-- | fs/bcachefs/snapshot.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/fs/bcachefs/snapshot.c b/fs/bcachefs/snapshot.c index 0e806f04f3d7..544322d5c251 100644 --- a/fs/bcachefs/snapshot.c +++ b/fs/bcachefs/snapshot.c @@ -125,6 +125,15 @@ static inline u32 get_ancestor_below(struct snapshot_table *t, u32 id, u32 ances return s->parent; } +static bool test_ancestor_bitmap(struct snapshot_table *t, u32 id, u32 ancestor) +{ + const struct snapshot_t *s = __snapshot_t(t, id); + if (!s) + return false; + + return test_bit(ancestor - id - 1, s->is_ancestor); +} + bool __bch2_snapshot_is_ancestor(struct bch_fs *c, u32 id, u32 ancestor) { bool ret; @@ -140,13 +149,11 @@ bool __bch2_snapshot_is_ancestor(struct bch_fs *c, u32 id, u32 ancestor) while (id && id < ancestor - IS_ANCESTOR_BITMAP) id = get_ancestor_below(t, id, ancestor); - if (id && id < ancestor) { - ret = test_bit(ancestor - id - 1, __snapshot_t(t, id)->is_ancestor); + ret = id && id < ancestor + ? test_ancestor_bitmap(t, id, ancestor) + : id == ancestor; - EBUG_ON(ret != __bch2_snapshot_is_ancestor_early(t, id, ancestor)); - } else { - ret = id == ancestor; - } + EBUG_ON(ret != __bch2_snapshot_is_ancestor_early(t, id, ancestor)); out: rcu_read_unlock(); |