[PATCH] device-mapper snapshot: bio_list fix
bio_list_merge() should do nothing if the second list is empty - not oops.
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/md/dm-bio-list.h b/drivers/md/dm-bio-list.h
index bc021e1..bbf4615 100644
--- a/drivers/md/dm-bio-list.h
+++ b/drivers/md/dm-bio-list.h
@@ -33,6 +33,9 @@
static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
{
+ if (!bl2->head)
+ return;
+
if (bl->tail)
bl->tail->bi_next = bl2->head;
else