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 A9CA6C43140 for ; Thu, 21 Jun 2018 13:13:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5EB6920837 for ; Thu, 21 Jun 2018 13:13:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="m07y7dDu" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5EB6920837 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 S933222AbeFUNNc (ORCPT ); Thu, 21 Jun 2018 09:13:32 -0400 Received: from aserp2130.oracle.com ([141.146.126.79]:34596 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932743AbeFUNNa (ORCPT ); Thu, 21 Jun 2018 09:13:30 -0400 Received: from pps.filterd (aserp2130.oracle.com [127.0.0.1]) by aserp2130.oracle.com (8.16.0.22/8.16.0.22) with SMTP id w5LD96ln145881; Thu, 21 Jun 2018 13:13:23 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=/KCwabEDvxG5JoMliUG82xtRoiEJbg1WvmkjL1wUi0k=; b=m07y7dDuyjqCqo9DMzoQiAgsgywqX6VCbLhzqAiHN2H5JfGlu8/mRHImABiveLqgbdNt /7XECVlIlxFX9JjpV6PJj5s72/tXHtNyPFarZ4uhaqJoL9tVRajcojs2Z2HcAKT9a5CF SCQJskygLJUEHBXp93MUtDbI8cU92hbfcYaBB/qenl09hUdLbyMUXD56G+1fFeFFJ0gY OcrZ/ZHS6K+qx5r6iAX+pduMa2A7PHnLH6AZxCgkPM/f+lxWO5HXALqY2Cx24HbuT24n QB/BUK/GPjn3Pqzkd+SVOyyR/aj8n0nu6K6ZE9pKQ2MmCJQ4YkEkrRWUFV3s3OGKHDf+ 5Q== Received: from aserv0021.oracle.com (aserv0021.oracle.com [141.146.126.233]) by aserp2130.oracle.com with ESMTP id 2jmr2mrura-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 21 Jun 2018 13:13:23 +0000 Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by aserv0021.oracle.com (8.14.4/8.14.4) with ESMTP id w5LDDMNn009185 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 21 Jun 2018 13:13:22 GMT Received: from abhmp0006.oracle.com (abhmp0006.oracle.com [141.146.116.12]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id w5LDDLiI026037; Thu, 21 Jun 2018 13:13:21 GMT Received: from [10.191.15.192] (/10.191.15.192) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 21 Jun 2018 06:13:20 -0700 Subject: Re: [PATCH 0/5]stop normal completion path entering a timeout req To: Christoph Hellwig Cc: Keith Busch , axboe@kernel.dk, martin.petersen@oracle.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> <20180620181601.GA24145@localhost.localdomain> <20180621081900.GA5183@lst.de> From: "jianchao.wang" Message-ID: Date: Thu, 21 Jun 2018 21:13:30 +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: <20180621081900.GA5183@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-1806210146 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Christoph On 06/21/2018 04:19 PM, Christoph Hellwig wrote: > On Thu, Jun 21, 2018 at 09:43:26AM +0800, jianchao.wang wrote: >> So we have to preserve the ability of block layer that it could prevent >> IO completion path from entering a timeout request. >> >> With scsi-debug module, I tried to simulate a scenario where timeout and IO >> completion path could occur concurrently, the system ran into crash easily. > > Trace, please. With the latest kernel. I'm not saying that there > is nothing to fix, but the mode of never completing once timeout > requests as currently done is SCSI is clearly broken. > Sorry, I don't quite get your point. Do you mean we should do the modification in the scsi layer ? Actually, I used to look at the code to try to stop io completion on timeout request in scsi-mid layer, but it looks like difficult, especially, scsi eh would try to borrow the command to issue admin command such as get sense, test unit,etc. Thanks Jianchao