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Date:   Mon, 10 Jul 2023 15:30:24 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     chengming.zhou@linux.dev
Cc:     axboe@kernel.dk, hch@lst.de, ming.lei@redhat.com,
        linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        zhouchengming@bytedance.com
Subject: Re: [PATCH 1/2] blk-flush: fix rq->flush.seq for post-flush
 requests
Message-ID: <20230710133024.GA23157@lst.de>
References: <20230710064705.1847287-1-chengming.zhou@linux.dev>
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On Mon, Jul 10, 2023 at 02:47:04PM +0800, chengming.zhou@linux.dev wrote:
> 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.

I wonder if it really doesn't cause any problems, but the change for
sure looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

It should probably go before your other flush optimizations and maybe
grow a fixes tag.