[PATCH] block: request_queue->ordcolor must not be flipped on SOFTBARRIER

q->ordcolor must not be flipped on SOFTBARRIER.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Acked-by: NJens Axboe <axboe@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

block/elevator.c

@@ -323,7 +323,8 @@ void __elv_add_request(request_queue_t *q, struct request *rq, int where,
 		/*
 		 * toggle ordered color
 		 */
-		q->ordcolor ^= 1;
+		if (blk_barrier_rq(rq))
+			q->ordcolor ^= 1;
 
 		/*
 		 * barriers implicitly indicate back insertion