[PATCH for-next] dm: fix missing bi_remaining accounting

[Mike Snitzer <snitzer@redhat.com>]

Add the missing bi_remaining increment, required by the block layer's
new bio-chaining code, to both the verity and old snapshot DM targets.

Otherwise users will hit the bi_remaining <= 0 BUG_ON in bio_endio().

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
---
 drivers/md/dm-snap.c   |    1 +
 drivers/md/dm-verity.c |    1 +
 2 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index b7a5053..1b4d22d 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -1415,6 +1415,7 @@ out:
 	if (full_bio) {
 		full_bio->bi_end_io = pe->full_bio_end_io;
 		full_bio->bi_private = pe->full_bio_private;
+		atomic_inc(&full_bio->bi_remaining);
 	}
 	free_pending_exception(pe);
 
diff --git a/drivers/md/dm-verity.c b/drivers/md/dm-verity.c
index ac35e95..dc15857 100644
--- a/drivers/md/dm-verity.c
+++ b/drivers/md/dm-verity.c
@@ -384,6 +384,7 @@ static void verity_finish_io(struct dm_verity_io *io, int error)
 
 	bio->bi_end_io = io->orig_bi_end_io;
 	bio->bi_private = io->orig_bi_private;
+	atomic_inc(&bio->bi_remaining);
 
 	bio_endio(bio, error);
 }