Re: [PATCH 1/2] blk-flush: fix rq->flush.seq for post-flush requests

From: Christoph Hellwig
Date: Mon Jul 10 2023 - 09:30:35 EST


On Mon, Jul 10, 2023 at 02:47:04PM +0800, chengming.zhou@xxxxxxxxx wrote:
> From: Chengming Zhou <zhouchengming@xxxxxxxxxxxxx>
>
> 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@xxxxxx>

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