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=-1.0 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 1E016C43441 for ; Wed, 28 Nov 2018 16:31:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D8673206B6 for ; Wed, 28 Nov 2018 16:31:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="ViSeo3v8" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D8673206B6 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-block-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728883AbeK2DdY (ORCPT ); Wed, 28 Nov 2018 22:33:24 -0500 Received: from mail-it1-f196.google.com ([209.85.166.196]:34579 "EHLO mail-it1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728181AbeK2DdX (ORCPT ); Wed, 28 Nov 2018 22:33:23 -0500 Received: by mail-it1-f196.google.com with SMTP id x124so5062470itd.1 for ; Wed, 28 Nov 2018 08:31:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=bgfVxIP+VmBP4nI08Mvdi3rlUWrHYvBlihd7QjTl5sI=; b=ViSeo3v8g3ymY7AHz9u+uEzTNFM7BIyHpDABLxyiSDkMxKG9URuT6pAG4EUlIh5zab XxKrXNALM0n09us7oU7ICudc0rTScUGpsjCZyTydzyHAd6xNPaqKkK4XQPQESWdeOzzi 6qZExmv4hW45ee9/FAOGj0PN7ObW0Tmq4nPh/+Ma5Jx1/o4KkT2vCbaNusWozGM0qplJ hKaNhZQ59WY4+9DEpMOn7/iovPsg2vgi+vpbd12jHeVtnIiHL/vBmactqJUybOTh2GL7 Jmu+0t7gKBpGhJZ2xK+PfRZXHYioFuDR/sELdt8X6gFcyYLkrzTZvr2xZIbvulruSyyR wmPw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=bgfVxIP+VmBP4nI08Mvdi3rlUWrHYvBlihd7QjTl5sI=; b=W8nMlUgiGTMHifYFUyOeD9oF2tX2jsg7wPOZi3TRP06SWdEjU38ch3WpUr41+m+NjG 15EuAEPcTzlH0L69mSkSnnQ6DXdIJen0+xIgS2ViDVBSBC2n5F1wO7LcSCGTAFaveoYL zVmm34JCTYVhbGfcFLcZ7sRSIydSMSrXI0X4h0Yw1L/kzX2sqczFDPy79fTacVbypRoQ 6ouQVvjm4Y89YClN/3ObGG612zRMi2S3jmWCfzWStWyr4xNk8ey86dLKXI+m2T9tGec2 ObwnpyvS2tHNAH887kxccdSRF3fqNfYzfHUIxsNkpr0/2r8m0tWhl3plOoPyYtXHcws/ m+Lw== X-Gm-Message-State: AA+aEWbhsaMDDXJa9xknZc6C1AjB7kkaokd+obwZ6mK6+rUXYalmZ4N7 ZixgvWLW4j9KMAim5uLIiWs4ug== X-Google-Smtp-Source: AFSGD/VI6PQcsJpqTMphhBjzE+UVVOj9o328ZXBykBf1o6EX6WAik3K/0GfBUHV4s9ShKlaDbOTUtg== X-Received: by 2002:a05:660c:34f:: with SMTP id b15mr3654563itl.146.1543422669489; Wed, 28 Nov 2018 08:31:09 -0800 (PST) Received: from [192.168.1.56] ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id q14sm1361111itb.36.2018.11.28.08.31.07 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 28 Nov 2018 08:31:08 -0800 (PST) Subject: Re: [PATCHv4 0/3] scsi timeout handling updates To: Keith Busch Cc: Christoph Hellwig , Ming Lei , linux-scsi@vger.kernel.org, linux-block@vger.kernel.org, Martin Petersen , Bart Van Assche References: <20181126165430.4519-1-keith.busch@intel.com> <20181128021959.GG11128@ming.t460p> <20181128070010.GA20369@lst.de> <20181128100659.GA16495@ming.t460p> <20181128100848.GA23567@lst.de> <20181128154927.GE6401@localhost.localdomain> <20181128162655.GF6401@localhost.localdomain> From: Jens Axboe Message-ID: <4071afee-5a4e-63bf-e834-44ccdb7026ae@kernel.dk> Date: Wed, 28 Nov 2018 09:31:07 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: <20181128162655.GF6401@localhost.localdomain> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 11/28/18 9:26 AM, Keith Busch wrote: > On Wed, Nov 28, 2018 at 08:58:00AM -0700, Jens Axboe wrote: >> On 11/28/18 8:49 AM, Keith Busch wrote: >>> On Wed, Nov 28, 2018 at 11:08:48AM +0100, Christoph Hellwig wrote: >>>> On Wed, Nov 28, 2018 at 06:07:01PM +0800, Ming Lei wrote: >>>>>> Is this the nvme target on top of null_blk? >>>>> >>>>> Yes. >>>> >>>> And it goes away if you revert just the last patch? >>> >>> It looks like a problem existed before that last patch. Reverting it >>> helps only if the request happened to have not been reallocated. If it >>> had been reallocated, the NULL_IRQ_TIMER would have completed the wrong >>> request out-of-order. If this were a real device, that'd probably result >>> in data corruption. >> >> null_blk just needs updating for this. > > Isn't this the nvme target's problem? It shouldn't complete requests > dispatched to its backing device, so I'm thinking something like the > following is what should happen. Untested at the moment, but will try > it out shortly. I looked at null_blk after the fact, and my recollection of how that timeout stuff worked was wrong. I think you are right. -- Jens Axboe