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Date:   Wed, 22 Sep 2021 17:22:07 +0800
From:   Ming Lei <ming.lei@redhat.com>
To:     "yukuai (C)" <yukuai3@huawei.com>
Cc:     josef@toxicpanda.com, axboe@kernel.dk, hch@infradead.org,
        linux-block@vger.kernel.org, nbd@other.debian.org,
        linux-kernel@vger.kernel.org, yi.zhang@huawei.com
Subject: Re: [patch v8 3/7] nbd: check sock index in nbd_read_stat()
Message-ID: <YUr1v8zylPOFFXTO@T590>
References: <20210916093350.1410403-1-yukuai3@huawei.com>
 <20210916093350.1410403-4-yukuai3@huawei.com>
 <7e2913ca-1089-9ab7-cfdb-5e8837d36034@huawei.com>
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In-Reply-To: <7e2913ca-1089-9ab7-cfdb-5e8837d36034@huawei.com>
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On Sun, Sep 19, 2021 at 06:34:28PM +0800, yukuai (C) wrote:
> On 2021/09/16 17:33, Yu Kuai wrote:
> > The sock that clent send request in nbd_send_cmd() and receive reply
> > in nbd_read_stat() should be the same.
> > 
> > Signed-off-by: Yu Kuai <yukuai3@huawei.com>
> > ---
> >   drivers/block/nbd.c | 4 ++++
> >   1 file changed, 4 insertions(+)
> > 
> > diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
> > index 614c6ab2b8fe..c724a5bd7fa4 100644
> > --- a/drivers/block/nbd.c
> > +++ b/drivers/block/nbd.c
> > @@ -746,6 +746,10 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index)
> >   		ret = -ENOENT;
> >   		goto out;
> >   	}
> > +	if (cmd->index != index) {
> > +		dev_err(disk_to_dev(nbd->disk), "Unexpected reply %d from different sock %d (expected %d)",
> > +			tag, index, cmd->index);
> > +	}
> >   	if (cmd->cmd_cookie != nbd_handle_to_cookie(handle)) {
> >   		dev_err(disk_to_dev(nbd->disk), "Double reply on req %p, cmd_cookie %u, handle cookie %u\n",
> >   			req, cmd->cmd_cookie, nbd_handle_to_cookie(handle));
> > 
> 
> Hi, Ming
> 
> Any suggestions about this patch?

I think this one relies on nbd protocol between server and client, and
does the protocol require both request and reply xmitted via same
socket?


Thanks,
Ming