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From:   chengming.zhou@linux.dev
To:     axboe@kernel.dk, hch@lst.de, ming.lei@redhat.com
Cc:     linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        zhouchengming@bytedance.com
Subject: [PATCH 1/2] blk-flush: fix rq->flush.seq for post-flush requests
Date:   Mon, 10 Jul 2023 14:47:04 +0800
Message-ID: <20230710064705.1847287-1-chengming.zhou@linux.dev>
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From: Chengming Zhou <zhouchengming@bytedance.com>

If the policy == (REQ_FSEQ_DATA | REQ_FSEQ_POSTFLUSH), it means that the
data sequence and post-flush sequence need to be done for this request.

The rq->flush.seq should record what sequences have been done (or don't
need to be done). So in this case, pre-flush doesn't need to be done,
we should init rq->flush.seq to REQ_FSEQ_PREFLUSH not REQ_FSEQ_POSTFLUSH.

Of course, this doesn't cause any problem in fact, since pre-flush and
post-flush sequence do the same thing for now.

But we'd better fix this value, and the next patch will depend on this
value to be correct.

Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
---
 block/blk-flush.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/blk-flush.c b/block/blk-flush.c
index 4826d2d61a23..094a6adb2718 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -448,7 +448,7 @@ bool blk_insert_flush(struct request *rq)
 		 * the post flush, and then just pass the command on.
 		 */
 		blk_rq_init_flush(rq);
-		rq->flush.seq |= REQ_FSEQ_POSTFLUSH;
+		rq->flush.seq |= REQ_FSEQ_PREFLUSH;
 		spin_lock_irq(&fq->mq_flush_lock);
 		fq->flush_data_in_flight++;
 		spin_unlock_irq(&fq->mq_flush_lock);
-- 
2.41.0