Re: [Xen-devel] [PATCH] xen_pvscsi: reclaim the ring request when mapping data failed

[Bin Wu]

On 2016/7/11 17:53, Juergen Gross wrote:
> On 11/07/16 11:50, David Vrabel wrote:
> > On 11/07/16 10:33, Juergen Gross wrote:
> > > On 11/07/16 04:51, Bin Wu wrote:
> > > > During scsi command queueing, if mapping data fails, we need to
> > > > reclaim the failed request. Otherwise, the garbage request will
> > > > be pushed into the ring for the backend to work.
> > > Well spotted. There is another instance of this problem in
> > > scsifront_action_handler(). Would you mind correcting this one, too?
> > Would it make more sense to advance req_prod_pvt only if the request has
> > been successfully created?
> Yeah, probably as the first action in scsifront_do_request().
>
>
> Juergen
ok, I will send a new patch : )
> > David
> >
> > > > Signed-off-by: Bin Wu <wu.wubin@xxxxxxxxxx>
> > > > ---
> > > >   drivers/scsi/xen-scsifront.c | 1 +
> > > >   1 file changed, 1 insertion(+)
> > > >
> > > > diff --git a/drivers/scsi/xen-scsifront.c b/drivers/scsi/xen-scsifront.c
> > > > index 9dc8687..655163d 100644
> > > > --- a/drivers/scsi/xen-scsifront.c
> > > > +++ b/drivers/scsi/xen-scsifront.c
> > > > @@ -565,6 +565,7 @@ static int scsifront_queuecommand(struct Scsi_Host
> > > > *shost,
> > > >       err = map_data_for_request(info, sc, ring_req, shadow);
> > > >       if (err < 0) {
> > > >           pr_debug("%s: err %d\n", __func__, err);
> > > > +        info->ring.req_prod_pvt--;
> > > >           scsifront_put_rqid(info, rqid);
> > > >           scsifront_return(info);
> > > >           spin_unlock_irqrestore(shost->host_lock, flags);
> > >
> > > _______________________________________________
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> > > https://lists.xen.org/xen-devel
>
> .