From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, T_DKIMWL_WL_HIGH autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A23DBC43140 for ; Thu, 21 Jun 2018 02:09:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5083C20693 for ; Thu, 21 Jun 2018 02:09:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="tzOkclnd" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5083C20693 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=oracle.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754527AbeFUCJP (ORCPT ); Wed, 20 Jun 2018 22:09:15 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:60078 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754290AbeFUCJN (ORCPT ); Wed, 20 Jun 2018 22:09:13 -0400 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.22/8.16.0.22) with SMTP id w5L28tNe172702; Thu, 21 Jun 2018 02:09:04 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=corp-2017-10-26; bh=62UuZQUCvTsZldJFUGRDXkct1+vF/UY+BIuwekRbX4w=; b=tzOkclndad9+z2+Jmc30p/9oj/ejFPdae8cVoyZsBq37X+DZIJUEWeK02b6azuWBnqeR AZcEoQDaX9hEOHgym2d1v0ymjGVH/wOulaBDbFnDZv2wPTS2tuLnTbRQextzoAk4xIWz ZBea692NdAqruuiAWpb7TQBCo72RpiMMC7XIsEonuWIR7MS0V6TshL5I/CF4LkYJ8zxR OW7RMoMDnu5gjLMejZ+yOX+g9q0c++cU3qIhMfN4TWKuaIutrqTyurigkUEW385G+WBn bvURz7PY0uLvMRsMYfQZLK3CZ7n2LHGaDoxjy7911huTVJOVxwJUokP8E9JiVY6N5m6m sw== Received: from userv0022.oracle.com (userv0022.oracle.com [156.151.31.74]) by userp2130.oracle.com with ESMTP id 2jmt01pw23-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 21 Jun 2018 02:09:04 +0000 Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userv0022.oracle.com (8.14.4/8.14.4) with ESMTP id w5L2938b018541 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 21 Jun 2018 02:09:03 GMT Received: from abhmp0019.oracle.com (abhmp0019.oracle.com [141.146.116.25]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id w5L292sr006775; Thu, 21 Jun 2018 02:09:02 GMT Received: from [10.182.70.180] (/10.182.70.180) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 20 Jun 2018 19:09:02 -0700 Subject: Re: [PATCH 5/5] nvme: use __blk_mq_complete_request in timeout path To: Christoph Hellwig Cc: axboe@kernel.dk, martin.petersen@oracle.com, keith.busch@intel.com, josef@toxicpanda.com, ulf.hansson@linaro.org, linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org References: <1529500964-28429-1-git-send-email-jianchao.w.wang@oracle.com> <1529500964-28429-6-git-send-email-jianchao.w.wang@oracle.com> <20180620143956.GA20950@lst.de> From: "jianchao.wang" Message-ID: <42583ee2-fe9d-39da-b82a-38a27b03fdb3@oracle.com> Date: Thu, 21 Jun 2018 10:09:20 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <20180620143956.GA20950@lst.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8930 signatures=668702 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1805220000 definitions=main-1806210022 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Christoph Thanks for your kindly response. On 06/20/2018 10:39 PM, Christoph Hellwig wrote: >> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c >> index 73a97fc..2a161f6 100644 >> --- a/drivers/nvme/host/pci.c >> +++ b/drivers/nvme/host/pci.c >> @@ -1203,6 +1203,7 @@ static enum blk_eh_timer_return nvme_timeout(struct request *req, bool reserved) >> nvme_warn_reset(dev, csts); >> nvme_dev_disable(dev, false); >> nvme_reset_ctrl(&dev->ctrl); >> + __blk_mq_complete_request(req); >> return BLK_EH_DONE; >> } >> >> @@ -1213,6 +1214,11 @@ static enum blk_eh_timer_return nvme_timeout(struct request *req, bool reserved) >> dev_warn(dev->ctrl.device, >> "I/O %d QID %d timeout, completion polled\n", >> req->tag, nvmeq->qid); >> + /* >> + * nvme_end_request will invoke blk_mq_complete_request, >> + * it will do nothing for this timed out request. >> + */ >> + __blk_mq_complete_request(req); > > And this clearly is bogus. We want to iterate over the tagetset > and cancel all requests, not do that manually here. > > That was the whole point of the original change. > For nvme-pci, we indeed have an issue that when nvme_reset_work->nvme_dev_disable returns, timeout path maybe still running and the nvme_dev_disable invoked by timeout path will race with the nvme_reset_work. However, the hole is still there right now w/o my changes, but just narrower. Thanks Jianchao