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

[Bin Wu <wu.wubin@huawei.com>]

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@huawei.com>
>>>> ---
>>>>   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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>>>
>>
>
> .
>