diff --git a/[refs] b/[refs]
index 11644b73ae3d..4b2380feaf4b 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 5c62cb48602dba95159c81ffeca179d3852e25be
+refs/heads/master: 64391b2536ca92f9c589b2bfeaca3954896fe057
diff --git a/trunk/drivers/block/xen-blkback/blkback.c b/trunk/drivers/block/xen-blkback/blkback.c
index c15c559e8662..53c81de6f886 100644
--- a/trunk/drivers/block/xen-blkback/blkback.c
+++ b/trunk/drivers/block/xen-blkback/blkback.c
@@ -707,8 +707,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
 	 * the hypercall to unmap the grants - that is all done in
 	 * xen_blkbk_unmap.
 	 */
-	if (operation != BLKIF_OP_DISCARD &&
-			xen_blkbk_map(req, pending_req, seg))
+	if (operation == REQ_DISCARD && xen_blkbk_map(req, pending_req, seg))
 		goto fail_flush;
 
 	/*