From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758165AbcGKJz6 (ORCPT ); Mon, 11 Jul 2016 05:55:58 -0400 Received: from mx2.suse.de ([195.135.220.15]:40527 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752303AbcGKJx7 (ORCPT ); Mon, 11 Jul 2016 05:53:59 -0400 Subject: Re: [Xen-devel] [PATCH] xen_pvscsi: reclaim the ring request when mapping data failed To: David Vrabel , Bin Wu , boris.ostrovsky@oracle.com, jejb@linux.vnet.ibm.com, martin.petersen@oracle.com, xen-devel@lists.xenproject.org, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org References: <578309AE.1080704@huawei.com> <578367E8.2050601@suse.com> <57836BF4.9090000@citrix.com> From: Juergen Gross Message-ID: <57836CB5.90401@suse.com> Date: Mon, 11 Jul 2016 11:53:57 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.7.0 MIME-Version: 1.0 In-Reply-To: <57836BF4.9090000@citrix.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 > > David > >>> Signed-off-by: Bin Wu >>> --- >>> 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); >> >> >> _______________________________________________ >> Xen-devel mailing list >> Xen-devel@lists.xen.org >> https://lists.xen.org/xen-devel >> > >