diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index b126c6f..a4b13b8 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -637,10 +637,23 @@
 }
 #endif /* CONFIG_MMU */
 
-#define rq_for_each_bio(_bio, rq)	\
+struct req_iterator {
+	int i;
+	struct bio *bio;
+};
+
+/* This should not be used directly - use rq_for_each_segment */
+#define __rq_for_each_bio(_bio, rq)	\
 	if ((rq->bio))			\
 		for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
 
+#define rq_for_each_segment(bvl, _rq, _iter)			\
+	__rq_for_each_bio(_iter.bio, _rq)			\
+		bio_for_each_segment(bvl, _iter.bio, _iter.i)
+
+#define rq_iter_last(rq, _iter)					\
+		(_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
+
 extern int blk_register_queue(struct gendisk *disk);
 extern void blk_unregister_queue(struct gendisk *disk);
 extern void register_disk(struct gendisk *dev);