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=-8.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 83776C433E1 for ; Tue, 18 Aug 2020 06:32:47 +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 5132D2067C for ; Tue, 18 Aug 2020 06:32:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="iF3RmpuH" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5132D2067C 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=Jry0njvqxW97anSRS/ccEt1DACMcPn0brZIDIqbFxkg=; b=iF3RmpuHpP5fE71bEy0G+6ZKG IxGeV0nYdIMSqKUQ5yc0kJ04tkOYqXhBgK7a3cXSNMvKbAfL1bxjHm+ne1Di0+xjdWA2F4kjLRQ3p pEx60r774Uv+sOWf2ZRzl/C819MYkZwMtKFLQVN5/QFeYWygnaGVM/gqbSWcRaa10tKVmilHuxDhm 4tFQnFcrsVNKf/OmNnGDrDWDYNAu6hedpuKphe6OPkqAT7iVSl8ITyPb0GevE4XgY6A1jjCTcf5ju ftvB3wlrOGLoapiwKXNH3onG3mqogn1Da4munGc0Jw+zpuvaUXGsNBmDglcXsUXw32XBW9kCXDvw7 s3tJdT74Q==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1k7vAq-0003o0-1Q; Tue, 18 Aug 2020 06:32:44 +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 1k7vAn-0003nN-Im for linux-nvme@lists.infradead.org; Tue, 18 Aug 2020 06:32:42 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id D382268AFE; Tue, 18 Aug 2020 08:32:39 +0200 (CEST) Date: Tue, 18 Aug 2020 08:32:39 +0200 From: Christoph Hellwig To: Mike Snitzer Subject: Re: [PATCH 4/4] nvme: redirect commands on dying queue Message-ID: <20200818063239.GC1754@lst.de> References: <20200817081544.837699-1-hch@lst.de> <20200817081544.837699-5-hch@lst.de> <20200817152321.GD30005@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200817152321.GD30005@redhat.com> 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-20200818_023241_754465_728ECFFC X-CRM114-Status: GOOD ( 15.30 ) 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 , Chao Leng , Christoph Hellwig , linux-nvme@lists.infradead.org, Sagi Grimberg 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 Mon, Aug 17, 2020 at 11:23:22AM -0400, Mike Snitzer wrote: > On Mon, Aug 17 2020 at 4:15am -0400, > Christoph Hellwig wrote: > > > From: Chao Leng > > > > If a command send through nvme-multipath failed on a dying queue, resend it > > on another path. > > > > Signed-off-by: Chao Leng > > [hch: rebased on top of the completion refactoring] > > Signed-off-by: Christoph Hellwig > > Reviewed-by: Sagi Grimberg > > Did we ever learn from Chao what the original issue was? Deciding to > failover on completion because blk_queue_dying(), without any other > insight, is definitely new to me. Yes. Basically the controller is going away after returning a retryable error. > But this looks fine, just in general such blk_queue_dying() checks are > pretty racey right? Feels like this might paper over something else but > without knowing more: But I guess the race doesn't matter - if we lose it, ->queue_rq will fail and the submission path will pick another path as well. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme