diff --git a/block/blk.h b/block/blk.h
index 9e0042c..c863ec2 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -13,6 +13,8 @@
 void init_request_from_bio(struct request *req, struct bio *bio);
 void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
 			struct bio *bio);
+int blk_rq_append_bio(struct request_queue *q, struct request *rq,
+		      struct bio *bio);
 void blk_dequeue_request(struct request *rq);
 void __blk_queue_free_tags(struct request_queue *q);