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 9E173C4332F for ; Wed, 8 Nov 2023 05:26:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234225AbjKHF0i (ORCPT ); Wed, 8 Nov 2023 00:26:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60506 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229574AbjKHF0h (ORCPT ); Wed, 8 Nov 2023 00:26:37 -0500 Received: from mail-pg1-f172.google.com (mail-pg1-f172.google.com [209.85.215.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 147D498; Tue, 7 Nov 2023 21:26:35 -0800 (PST) Received: by mail-pg1-f172.google.com with SMTP id 41be03b00d2f7-5b9a7357553so5025712a12.0; Tue, 07 Nov 2023 21:26:35 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699421194; x=1700025994; h=content-transfer-encoding:in-reply-to:from:references:cc: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=RetVwMMps3v0wuYvBP5PRz6XNs49BLOh+F6Kj2NY2i4=; b=J0f8t9yrd7wcaFw3SNV4MriaiZqbjcJhCQZuMOzm5suzQ+j4IGp5nWKDEUkfRAA/9B jWO2Rqk3dN2StHpdPokJnfIDiB0+/Q72mw3rq/3/V+w9aFE7AVcU4xDIjSqqNqEI4YIE QbEMw/EB2wcYIab189b79Y8QDehubpsYFu75r4Ejb/eirGL1fHENji+G2YxcT33vLR2y 65AvEsZuFcrrPvqp14bE7A9Yn28KmEw1xRYTayFibq6aHVaG2vQFZFdEghpde0F8AxE5 Q+Be1a1Wvw+VdqUgj/p85hE4MwkCcA1yMVAm0K1VWwajmhZyyT1nMF+nxC6uM1t+mZq3 I23A== X-Gm-Message-State: AOJu0YyU59UvNNeOBN/zLRxTnr4MzPxNnZKL9rdMjUCK6YAzfGxtfqGb rdw+ZP5zjxqbZD0c6mHhAMo= X-Google-Smtp-Source: AGHT+IG6r/xsxVWQjB8Trj0a2s94siLsxt+R7G2yf3eYYClkPjWYNhRjMsrSNaVLbA/3OxVfkyigpQ== X-Received: by 2002:a17:90b:805:b0:27d:6dd:fb7d with SMTP id bk5-20020a17090b080500b0027d06ddfb7dmr900492pjb.17.1699421194228; Tue, 07 Nov 2023 21:26:34 -0800 (PST) Received: from [192.168.51.14] (c-73-231-117-72.hsd1.ca.comcast.net. [73.231.117.72]) by smtp.gmail.com with ESMTPSA id em16-20020a17090b015000b0026b12768e46sm695943pjb.42.2023.11.07.21.26.33 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 07 Nov 2023 21:26:33 -0800 (PST) Message-ID: <25a94b23-b42b-49fc-a1c8-3e635f536aae@acm.org> Date: Tue, 7 Nov 2023 21:26:32 -0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] null_blk: fix warning in blk_mq_start_request Content-Language: en-US To: Edward Adam Davis , syzbot+fcc47ba2476570cbbeb0@syzkaller.appspotmail.com Cc: axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com References: <0000000000000e6aac06098aee0c@google.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 11/7/23 18:46, Edward Adam Davis wrote: > Before call blk_mq_start_request() in null_queue_rq(), initialize rq->state to > MQ_RQ_IDLE. > > Reported-and-tested-by: syzbot+fcc47ba2476570cbbeb0@syzkaller.appspotmail.com > Signed-off-by: Edward Adam Davis > --- > drivers/block/null_blk/main.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c > index 22a3cf7f32e2..0726534a5a24 100644 > --- a/drivers/block/null_blk/main.c > +++ b/drivers/block/null_blk/main.c > @@ -1724,6 +1724,8 @@ static blk_status_t null_queue_rq(struct blk_mq_hw_ctx *hctx, > cmd->fake_timeout = should_timeout_request(rq) || > blk_should_fake_timeout(rq->q); > > + if (READ_ONCE(rq->state)) > + WRITE_ONCE(rq->state, MQ_RQ_IDLE); > blk_mq_start_request(rq); > > if (should_requeue_request(rq)) { All code that changes rq->state should occur in the block layer core. Block drivers must not modify rq->state directly. Bart.