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=-5.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 EE61BC433E0 for ; Thu, 21 Jan 2021 09:00:27 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 615B722473 for ; Thu, 21 Jan 2021 09:00:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 615B722473 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=EOIZvLSwIT7V2hVT5ph4CjdB6024FRmCA4ddDS5jjU8=; b=Ph7ywCo7whp6RWMvi78Lj2QdH L5izAxQY6g6bs7a/4DsOKv2XY1uSK8elj010+d/zjPVDhPu9+QsHIE4M5zNzBDXzTEs42UahSZAzS Iph5x/r/zdHkTIwW+N54YLz0yqfjg54XCxhEwI/VKk05CjHo6Ff2QWRVGO+6srgrPUKKje/JQgleC zZcki9lTl3RAU05oVgkwOe+xPwn8ilZ5SgQsRetFBO9IVO3ZKa1EG1E16XTh2CsoUSEJDh8k57IA1 7SwRIOY7H70UEU9bKbqlJIvoXh7LzVhxexoxkhCCIaxdJh6EXrE8ZlfPlTLlZjilsTaqC+SDmRWpW vd7/ddm2w==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l2VpE-0001h4-3A; Thu, 21 Jan 2021 09:00:20 +0000 Received: from verein.lst.de ([213.95.11.211]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l2VpB-0001gU-Om for linux-nvme@lists.infradead.org; Thu, 21 Jan 2021 09:00:18 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id D723C67373; Thu, 21 Jan 2021 10:00:12 +0100 (CET) Date: Thu, 21 Jan 2021 10:00:12 +0100 From: Christoph Hellwig To: Hannes Reinecke Subject: Re: [PATCH v3 3/5] nvme-fabrics: avoid double request completion for nvmf_fail_nonready_command Message-ID: <20210121090012.GA27342@lst.de> References: <20210121070330.19701-1-lengchao@huawei.com> <20210121070330.19701-4-lengchao@huawei.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210121_040017_914715_29DB6F27 X-CRM114-Status: GOOD ( 11.85 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: axboe@kernel.dk, axboe@fb.com, sagi@grimberg.me, linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, Chao Leng , kbusch@kernel.org, hch@lst.de Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Thu, Jan 21, 2021 at 09:58:37AM +0100, Hannes Reinecke wrote: > On 1/21/21 8:03 AM, Chao Leng wrote: >> When reconnect, the request may be completed with NVME_SC_HOST_PATH_ERROR >> in nvmf_fail_nonready_command. The state of request will be changed to >> MQ_RQ_IN_FLIGHT before call nvme_complete_rq. If free the request >> asynchronously such as in nvme_submit_user_cmd, in extreme scenario >> the request may be completed again in tear down process. >> nvmf_fail_nonready_command do not need calling blk_mq_start_request >> before complete the request. nvmf_fail_nonready_command should set >> the state of request to MQ_RQ_COMPLETE before complete the request. >> > > So what you are saying is that there is a race condition between > blk_mq_start_request() > and > nvme_complete_request() Between those to a teardwon that cancels all requests can come in. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme