On 29/11/16 12:14, Jan Beulich wrote: >>>> On 29.11.16 at 11:50, <JGross@xxxxxxxx> wrote: >> --- a/drivers/scsi/xen-scsifront.c >> +++ b/drivers/scsi/xen-scsifront.c >> @@ -184,8 +184,6 @@ static struct vscsiif_request *scsifront_pre_req(struct vscsifrnt_info *info) >> >> ring_req = RING_GET_REQUEST(&(info->ring), ring->req_prod_pvt); >> >> - ring->req_prod_pvt++; > > Please note the "_pvt" suffix, which stands for "private": This field is > not visible to the backend. Only ring->sring fields are shared, and > the updating of the shared field happens in RING_PUSH_REQUESTS() > and RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(). Sure, but RING_PUSH_REQUESTS() will copy req_prod_pvt to req_prod. In the case corrected this would advance req_prod by two after the error case before, even if only one request would have made it to the ring. As an alternative I could have decremented req_prod_pvt in case of an error, but I like my current solution better. Juergen -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
