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=-2.2 required=3.0 tests=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 AA197C432C2 for ; Wed, 25 Sep 2019 23:32:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8136120673 for ; Wed, 25 Sep 2019 23:32:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728871AbfIYXcD (ORCPT ); Wed, 25 Sep 2019 19:32:03 -0400 Received: from mail-pf1-f194.google.com ([209.85.210.194]:39805 "EHLO mail-pf1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728763AbfIYXcD (ORCPT ); Wed, 25 Sep 2019 19:32:03 -0400 Received: by mail-pf1-f194.google.com with SMTP id v4so505470pff.6 for ; Wed, 25 Sep 2019 16:32:01 -0700 (PDT) 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=Zv+S6pjWtvFhuQbYqez+zraCSpqOxxH8byyf3vdShY8=; b=RMpFJgEBWvRPcC49ocCCBJxKMDWxY+r/V8vFHbgVX5Y03uHyyF1mOENQtzLc97iD+G RO/PuZjaoLE3SNc1gILJglNgo1hQPm1cSlhC9BwcnGnzV6NqlPmN2hebeToznH7oApTI Oj+OXUFt9f+rqZ1wd4n6AuAeYtk3uGcxdfpQiLq/P6Ad11prbSaa+9rOsU4s8efhnHPr tkMycmD+ItCghlK9NEbXP/x3fp3EidE1j7QnaZKui1PRwrfOQg0p0whavCXXBSJLi+Ve vWhJlelWjSNntao7DVVJNWgu8WYmduBXB1yuhCdxuukn8xYHB4jIiMM/pQEDPevbel1P beRg== X-Gm-Message-State: APjAAAWxkLyBGvbp2PRNfQv39iKZzBaRxCYJ3rdc+ow+YTEtYB4Uopdu KMBC/mEpydRPCG7Gjz4IABqdsdwL X-Google-Smtp-Source: APXvYqxbsIk+2Js9U9t4kDbJcYgCQHgUGJUHXj5TD56WxxKrvkBwwoJq2SCTP6Vh5rfGKRThg73zgg== X-Received: by 2002:a17:90a:db47:: with SMTP id u7mr284929pjx.40.1569454321508; Wed, 25 Sep 2019 16:32:01 -0700 (PDT) Received: from desktop-bart.svl.corp.google.com ([2620:15c:2cd:202:4308:52a3:24b6:2c60]) by smtp.gmail.com with ESMTPSA id v4sm104183pff.181.2019.09.25.16.32.00 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 25 Sep 2019 16:32:00 -0700 (PDT) Subject: Re: [PATCH] blk-mq: move lockdep_assert_held() into elevator_exit To: Ming Lei , Jens Axboe Cc: linux-block@vger.kernel.org, Damien Le Moal , syzbot+da3b7677bb913dc1b737@syzkaller.appspotmail.com References: <20190925222354.26152-1-ming.lei@redhat.com> From: Bart Van Assche Message-ID: <492f8cb4-2fbe-2c34-4792-7cc56f81a14a@acm.org> Date: Wed, 25 Sep 2019 16:31:59 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190925222354.26152-1-ming.lei@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed 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 9/25/19 3:23 PM, Ming Lei wrote: > Commit c48dac137a62 ("block: don't hold q->sysfs_lock in elevator_init_mq") > removes q->sysfs_lock from elevator_init_mq(), but forgot to deal with > lockdep_assert_held() called in blk_mq_sched_free_requests() which is > run in failure path of elevator_init_mq(). > > blk_mq_sched_free_requests() is called in the following 3 functions: > > elevator_init_mq() > elevator_exit() > blk_cleanup_queue() > > In blk_cleanup_queue(), blk_mq_sched_free_requests() is followed exactly > by 'mutex_lock(&q->sysfs_lock)'. > > So moving the lockdep_assert_held() from blk_mq_sched_free_requests() > into elevator_exit() for fixing the report by syzbot. Reviewed-by: Bart Van Assche