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

From: David Vrabel
Date: Mon Jul 11 2016 - 05:51:27 EST


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?

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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