Re: [V9fs-developer] [PATCH] 9p/trans_virtio: discard zero-length reply

["Michael S. Tsirkin" <mst@redhat.com>]

OK, I've queued it.

On Thu, Feb 08, 2018 at 06:52:32PM +0100, Greg Kurz wrote:
> Ping ?
> 
> Michael,
> 
> Since this is virtio code and you have acked the QEMU part of the fix already,
> would you be kind enough to take this through your tree ?
> 
> Cheers,
> 
> --
> Greg
> 
> On Mon, 22 Jan 2018 22:02:05 +0100
> Greg Kurz <groug@kaod.org> wrote:
> 
> > When a 9p request is successfully flushed, the server is expected to just
> > mark it as used without sending a 9p reply (ie, without writing data into
> > the buffer). In this case, virtqueue_get_buf() will return len == 0 and
> > we must not report a REQ_STATUS_RCVD status to the client, otherwise the
> > client will erroneously assume the request has not been flushed.
> > 
> > Signed-off-by: Greg Kurz <groug@kaod.org>
> > ---
> >  net/9p/trans_virtio.c |    3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
> > index 0845aad4ba51..ca08c72ef4de 100644
> > --- a/net/9p/trans_virtio.c
> > +++ b/net/9p/trans_virtio.c
> > @@ -171,7 +171,8 @@ static void req_done(struct virtqueue *vq)
> >  		spin_unlock_irqrestore(&chan->lock, flags);
> >  		/* Wakeup if anyone waiting for VirtIO ring space. */
> >  		wake_up(chan->vc_wq);
> > -		p9_client_cb(chan->client, req, REQ_STATUS_RCVD);
> > +		if (len)
> > +			p9_client_cb(chan->client, req, REQ_STATUS_RCVD);
> >  	}
> >  }
> >  
> > 
> > 
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