diff options
| author | Mikulas Patocka <mpatocka@redhat.com> | 2021-05-25 13:17:19 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-06-03 08:22:05 +0200 |
| commit | eb787192910ee8fca9764c376f392e0ab69de58e (patch) | |
| tree | 7b9139b0cc4502335ede8170a9540fc18267d0e8 | |
| parent | 6bc28ede7bf3fefd837210b6ba05c91983249796 (diff) | |
dm snapshot: properly fix a crash when an origin has no snapshots
commit 7e768532b2396bcb7fbf6f82384b85c0f1d2f197 upstream.
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.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/md/dm-snap.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c index 2a1a7025b4b9..cbd3dbfad7d1 100644 --- a/drivers/md/dm-snap.c +++ b/drivers/md/dm-snap.c @@ -789,7 +789,7 @@ 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) |