diff options
| author |   Mikulas Patocka <mpatocka@redhat.com> | 2021-05-07 11:38:10 -0400 |
|---|---|---|
| committer |   Mike Snitzer <snitzer@redhat.com> | 2021-05-10 11:11:36 -0400 |
| commit | 7ee06ddc4038f936b0d4459d37a7d4d844fb03db (patch) | |
| tree | 031bf1397372f0c2f2d3180e16619578387f1c75 /drivers/md/dm-snap.c | |
| parent | Linux 5.13-rc1 (diff) | |
| download | linux-dev-7ee06ddc4038f936b0d4459d37a7d4d844fb03db.tar.xz linux-dev-7ee06ddc4038f936b0d4459d37a7d4d844fb03db.zip | |
dm snapshot: fix a crash when an origin has no snapshots
If an origin target has no snapshots, o->split_boundary is set to 0.
This causes BUG_ON(sectors <= 0) in block/bio.c:bio_split().
Fix this by initializing chunk_size, and in turn split_boundary, to
rounddown_pow_of_two(UINT_MAX) -- the largest power of two that fits
into "unsigned" type.
Reported-by: Michael Tokarev <mjt@tls.msk.ru>
Tested-by: Michael Tokarev <mjt@tls.msk.ru>
Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-snap.c')
| -rw-r--r-- | drivers/md/dm-snap.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c index a2acb014c13a..2a51ddd840b4 100644 --- a/drivers/md/dm-snap.c +++ b/drivers/md/dm-snap.c @@ -855,12 +855,11 @@ static int dm_add_exception(void *context, chunk_t old, chunk_t new) static uint32_t __minimum_chunk_size(struct origin *o) { struct dm_snapshot *snap; - unsigned chunk_size = 0; + unsigned chunk_size = rounddown_pow_of_two(UINT_MAX); if (o) list_for_each_entry(snap, &o->snapshots, list) - chunk_size = min_not_zero(chunk_size, - snap->store->chunk_size); + chunk_size = min(chunk_size, snap->store->chunk_size); return (uint32_t) chunk_size; } |