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=-5.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,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 635CCC433E0 for ; Tue, 11 Aug 2020 03:45:58 +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 2F90B206EF for ; Tue, 11 Aug 2020 03:45:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="AA6uuYwi" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2F90B206EF Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com 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-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=1db+WwPpsE7h9scqgt1oc/P9Q1pyRTeUdN/ZX3HmUho=; b=AA6uuYwi9CmzZTX8VfZG4Xu4M 0Rv+Lmbfg7s93sOCtXcX0OpRGgR2/2Z+3J8GWabek/trDYfzXIlePkBfkcUIx6U6ZkVx2NvxNxNtm 6A1VNgwJNlHNvYx+ef/6Yn9VWiivj1OY83gBnfa5ohswvUwCN0E7SYal7TqkMT0tz5WhUSxh5cbkB btq/s3fjn8d6KqBD5KIu6GTlxvIp24j+ya3EjBNgOClC4WUBRA8SRuFO17QPlOs/qbE7fS+rHmivm SSEwrJrQ2PkMMMU+//BMtJiHtwXcBlMdLIgGXN4Va4RivAbVQUippGrEHXes1EEFyk0l9akJCX1NS z124BelnA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1k5LEV-0008Nz-SP; Tue, 11 Aug 2020 03:45:51 +0000 Received: from szxga06-in.huawei.com ([45.249.212.32] helo=huawei.com) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1k5LES-0008NN-KV for linux-nvme@lists.infradead.org; Tue, 11 Aug 2020 03:45:49 +0000 Received: from DGGEMS402-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id DBEF2B0C725C53E21457; Tue, 11 Aug 2020 11:45:44 +0800 (CST) Received: from [10.169.42.93] (10.169.42.93) by DGGEMS402-HUB.china.huawei.com (10.3.19.202) with Microsoft SMTP Server id 14.3.487.0; Tue, 11 Aug 2020 11:45:41 +0800 Subject: Re: [PATCH] nvme: restore use of blk_path_error() in nvme_complete_rq() To: Christoph Hellwig , Mike Snitzer References: <20200729055903.GC31113@lst.de> <43e5dee8-1a91-4d8b-fdb5-91f9679ddeb3@huawei.com> <8d01b123-478f-f057-1598-8283dd099b03@huawei.com> <20200805152905.GB1982647@dhcp-10-100-145-180.wdl.wdc.com> <255d55e3-f824-a968-e478-3efeda095696@huawei.com> <20200806142625.GA3075319@dhcp-10-100-145-180.wdl.wdc.com> <729820BC-5F38-4E22-A83A-862E57BAE201@netapp.com> <20200806184057.GA27858@redhat.com> <20200806191943.GA27868@redhat.com> <20200810124355.GB25070@infradead.org> From: Chao Leng Message-ID: <67e83d28-a785-a1fd-7787-24d1217ca30b@huawei.com> Date: Tue, 11 Aug 2020 11:45:40 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: <20200810124355.GB25070@infradead.org> Content-Language: en-US X-Originating-IP: [10.169.42.93] X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200810_234548_948542_48E4D6AF X-CRM114-Status: GOOD ( 16.20 ) 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: Keith Busch , Hannes Reinecke , "linux-nvme@lists.infradead.org" , Ewan Milne , "Meneghini, John" Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On 2020/8/10 20:43, Christoph Hellwig wrote: > Just returning from my vacation, and I'm really surprised about > this discussion. > > If you want to fix a device mapper / block layer interaction you do > not change nvme code to use suboptimal interfaces. Agree. Nvme define path error and local retry mechanism. It is more reasonable to use the new mechanism. > > One of the reasons for the nvme multipath design was to allow for > tighter integration with protocol features, and making nvme do a detour > through the block layer for no good reason at all does not help with > that at all. Nvme should use local retry mechanism. But now we first check the flag: REQ_FAILFAST_TRANSPORT, if work with dm-multipath, REQ_FAILFAST_TRANSPORT will be set, this interrupt local retry. > > And if you want to support the TP that added the new command interrupted > status code please read through it - the status code itself is just a > small part of it, and none of the changes proposed in these discussions > would lead to a proper implementation. > . > _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme