diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index fc0dce0..0430ea3 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -561,6 +561,7 @@
 extern int blk_rq_map_user(request_queue_t *, struct request *, void __user *, unsigned int);
 extern int blk_rq_unmap_user(struct bio *, unsigned int);
 extern int blk_rq_map_kern(request_queue_t *, struct request *, void *, unsigned int, unsigned int);
+extern int blk_rq_map_user_iov(request_queue_t *, struct request *, struct sg_iovec *, int);
 extern int blk_execute_rq(request_queue_t *, struct gendisk *, struct request *);
 
 static inline request_queue_t *bdev_get_queue(struct block_device *bdev)