[PATCH] dm cache: increment bi_remaining when bi_end_io is restored

[Mike Snitzer <snitzer@redhat.com>]

Move the bio->bi_remaining increment into dm_unhook_bio() so the
overwrite_endio() handler works as expected.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
---
 drivers/md/dm-cache-target.c |   12 ++++++------
 1 files changed, 6 insertions(+), 6 deletions(-)

[Jens: this one would've been needed as a post-merge fix for v3.13 but
 immutable biovecs fell out.. please apply to your for-3.14/core]

diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index bf3a206..7c8dd1f 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -85,6 +85,12 @@ static void dm_unhook_bio(struct dm_hook_info *h, struct bio *bio)
 {
 	bio->bi_end_io = h->bi_end_io;
 	bio->bi_private = h->bi_private;
+
+	/*
+	 * Must bump bi_remaining to allow bio to complete with
+	 * restored bi_end_io.
+	 */
+	atomic_inc(&bio->bi_remaining);
 }
 
 /*----------------------------------------------------------------*/
@@ -765,12 +771,6 @@ static void writethrough_endio(struct bio *bio, int err)
 
 	dm_unhook_bio(&pb->hook_info, bio);
 
-	/*
-	 * Must bump bi_remaining to allow bio to complete with
-	 * restored bi_end_io.
-	 */
-	atomic_inc(&bio->bi_remaining);
-
 	if (err) {
 		bio_endio(bio, err);
 		return;
-- 
1.7.1