[dm-devel] [PATCH 10/12] dm-snapshot-merge-make-exceptions-in-other-snapshots-if-remapped-to-origin

[Mike Snitzer]

From: Mikulas Patocka <mpatocka at redhat.com>

If dispatching write request to merging snapshot device directly to the origin
(because the chunk is not remapped or was already merged), we must make
exceptions in other snapshots.

Signed-off-by: Mikulas Patocka <mpatocka at redhat.com>
Reviewed-by: Mike Snitzer <snitzer at redhat.com>
---
 drivers/md/dm-snap.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 3be57ba..8060fe3 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -1488,6 +1488,11 @@ static int snapshot_merge_map(struct dm_target *ti, struct bio *bio,
 
 	bio->bi_bdev = s->origin->bdev;
 
+	if (bio_rw(bio) == WRITE) {
+		up_write(&s->lock);
+		return do_origin(s->origin, bio);
+	}
+
  out_unlock:
 	up_write(&s->lock);
 
-- 
1.6.2.5