[PATCH] Fixup blk_rq_unmap_user() API

The blk_rq_unmap_user() API is not very nice. It expects the caller to
know that rq->bio has to be reset to the original bio, and it will
silently do nothing if that is not done. Instead make it explicit that
we need to pass in the first bio, by expecting a bio argument.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 0fa3301..36a6eac 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -672,7 +672,7 @@
 extern void blk_run_queue(request_queue_t *);
 extern void blk_start_queueing(request_queue_t *);
 extern int blk_rq_map_user(request_queue_t *, struct request *, void __user *, unsigned long);
-extern int blk_rq_unmap_user(struct request *);
+extern int blk_rq_unmap_user(struct bio *);
 extern int blk_rq_map_kern(request_queue_t *, struct request *, void *, unsigned int, gfp_t);
 extern int blk_rq_map_user_iov(request_queue_t *, struct request *,
 			       struct sg_iovec *, int, unsigned int);