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Date:   Thu, 28 Oct 2021 17:18:51 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Jens Axboe <axboe@kernel.dk>
Cc:     "Alexander V. Buev" <a.buev@yadro.com>,
        linux-block@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
        "Martin K . Petersen" <martin.petersen@oracle.com>,
        Mikhail Malygin <m.malygin@yadro.com>, linux@yadro.com
Subject: Re: [PATCH 0/3] implement direct IO with integrity
Message-ID: <20211028151851.GC9468@lst.de>
References: <20211028112406.101314-1-a.buev@yadro.com> <bc336e90-378e-6016-ea1c-d519290dce5f@kernel.dk>
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On Thu, Oct 28, 2021 at 09:13:07AM -0600, Jens Axboe wrote:
> A couple of suggestions on this:
> 
> 1) Don't think we need an IOSQE flag, those are mostly reserved for
>    modifiers that apply to (mostly) all kinds of requests
> 2) I think this would be cleaner as a separate command, rather than
>    need odd adjustments and iov assumptions. That also gets it out
>    of the fast path.
> 
> I'd add IORING_OP_READV_PI and IORING_OP_WRITEV_PI for this, I think
> you'd end up with a much cleaner implementation that way.

Agreed.  I also wonder if we could do saner paramter passing.
E.g. pass a separate pointer to the PI data if we find space for
that somewhere in the SQE.