From: Tejun Heo <htejun@gmail.com>
Date: Sun, 5 Feb 2006 07:27:38 +0000 (-0800)
Subject: [PATCH] block: request_queue->ordcolor must not be flipped on SOFTBARRIER
X-Git-Tag: v2.6.16-rc3~172
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=238e7db9357bfe1ce3d6f7ac1e60e595e9d46b7b;p=linux-2.6

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

q->ordcolor must not be flipped on SOFTBARRIER.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/block/elevator.c b/block/elevator.c
index 96a61e029c..2fc269f697 100644
--- a/block/elevator.c
+++ b/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