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Subject: [RFC]block: don't mark flush request as SOFTBARRIER
From: Shaohua Li <shaohua.li@intel.com>
To: lkml <linux-kernel@vger.kernel.org>
Cc: Jens Axboe <jaxboe@fusionio.com>, Tejun Heo <htejun@gmail.com>,
        Vivek Goyal <vgoyal@redhat.com>
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Date: Thu, 08 Sep 2011 09:29:54 +0800
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I'm wondering why flush request should be marked as SOFTBARRIER. Current flush
sequence guarantees the correctness of flush even the request is reordered by
ioscheduler.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>

diff --git a/block/elevator.c b/block/elevator.c
index a3b64bc..e589b76 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -715,7 +715,6 @@ void __elv_add_request(struct request_queue *q, struct request *rq, int where)
 		break;
 
 	case ELEVATOR_INSERT_FLUSH:
-		rq->cmd_flags |= REQ_SOFTBARRIER;
 		blk_insert_flush(rq);
 		break;
 	default: