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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0FAB2C4332F for ; Mon, 13 Nov 2023 23:57:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230223AbjKMX5o (ORCPT ); Mon, 13 Nov 2023 18:57:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35816 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229511AbjKMX5n (ORCPT ); Mon, 13 Nov 2023 18:57:43 -0500 Received: from mail-pg1-f180.google.com (mail-pg1-f180.google.com [209.85.215.180]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9479519E; Mon, 13 Nov 2023 15:57:40 -0800 (PST) Received: by mail-pg1-f180.google.com with SMTP id 41be03b00d2f7-517ab9a4a13so3998660a12.1; Mon, 13 Nov 2023 15:57:40 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699919860; x=1700524660; h=content-transfer-encoding:in-reply-to:from:references:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=2O33Z20Hw5m9jWPSsRRvDoAMyIPjKTQaup/hA8pvVwg=; b=rQzftL3T3jXjBlwlBEdQwrraDjCYgUR7plDSi6DH5jUJRjUDtvGNIt8au6aR2oZho4 E5pDrByXLDc0Uj9e8QRSmqmSmtGCfqD1kM5fdHR04QunTjS3zGhQS/Gwozaer+sOnY68 q7kOIsWSytpcgUr38fGR91P2qn2j5ZfItvKPu19vM8vfU6q6uN4HNWSHJV4HhVVHKXws wQlqbdVAuvTIo9dbLdI5uWZjPoBVeiyPNl48BIiYkj/iMXzA6pwXn5/8RamECrwfw1jg SQPY4Gc6pCoFT3DfQ/v3XOtqk3X3jr+qqwVbWeDrzh4ORUcqx9fd6iqhF3Yvcy9rfkei DbVg== X-Gm-Message-State: AOJu0YzC2uhvltaviwnhdkM/Q5Zy/ocLiUoOevkgARFDkjntb129AeIh I9MtcMFKD2NXXwdptUA2gIw1iGhoW4M= X-Google-Smtp-Source: AGHT+IHuHxh5mqX7RqLGEoVItvxSJ0QEO1HWwHcQdsilEu8FzLk6SzflzOyi+wzsLftN0NQJT9fDDg== X-Received: by 2002:a05:6a20:8408:b0:186:736f:7798 with SMTP id c8-20020a056a20840800b00186736f7798mr5840594pzd.11.1699919859795; Mon, 13 Nov 2023 15:57:39 -0800 (PST) Received: from ?IPV6:2620:0:1000:8411:7575:f839:a613:3f5b? ([2620:0:1000:8411:7575:f839:a613:3f5b]) by smtp.gmail.com with ESMTPSA id x14-20020aa784ce000000b006b97d5cbb7csm143897pfn.60.2023.11.13.15.57.38 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 13 Nov 2023 15:57:39 -0800 (PST) Message-ID: <3f2c2d33-2e5d-4c7b-80ea-e76885981dfb@acm.org> Date: Mon, 13 Nov 2023 15:57:38 -0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [External] Re: [syzbot] [block?] WARNING in blk_mq_start_request Content-Language: en-US To: Chengming Zhou , syzbot , axboe@kernel.dk, chaitanyak@nvidia.com, eadavis@qq.com, hch@infradead.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, ming.lei@redhat.com, syzkaller-bugs@googlegroups.com References: <00000000000077ca930609aa9f86@google.com> <7ed9f6f9-d309-4d30-9b3b-c465cfa48a52@bytedance.com> From: Bart Van Assche In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/13/23 07:05, Chengming Zhou wrote: > Ok, I reviewed the code of virtio_queue_rqs(), found the main difference > is that request won't fail after blk_mq_start_request(). > > But in null_blk case, the request will fail after blk_mq_start_request(), > return BLK_STS_RESOURCE or BLK_STS_DEV_RESOURCE. If we return these rqs > back to the block layer core, they will be queued individually once again. > So caused the warning. I think it is safe to move the blk_mq_start_request() call under the if-block that decides whether or not to requeue a request in null_queue_rq() Thanks, Bart.