dm cache: increment bi_remaining when bi_end_io is restored

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>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/md/dm-cache-target.c

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 @@
 {
 	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 @@
 
 	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;