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=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL 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 3976BC54E8B for ; Tue, 12 May 2020 10:15:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1898B20736 for ; Tue, 12 May 2020 10:15:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="GZmCrcjg" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729398AbgELKPZ (ORCPT ); Tue, 12 May 2020 06:15:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54962 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726891AbgELKPW (ORCPT ); Tue, 12 May 2020 06:15:22 -0400 Received: from mail-qk1-x743.google.com (mail-qk1-x743.google.com [IPv6:2607:f8b0:4864:20::743]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1684FC061A0C for ; Tue, 12 May 2020 03:15:22 -0700 (PDT) Received: by mail-qk1-x743.google.com with SMTP id b188so12912297qkd.9 for ; Tue, 12 May 2020 03:15:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=iPvMln8fETCvIb1O9zDTgMvwvAqRofofWlm0c6p2k1M=; b=GZmCrcjgtcCm4s480qly1KJ1qHt6LNr4Iqs2eH8PDxX04Qxu6dMhKOGW1hLPe3zrEe HCQ/K3D2cSoKKhNEZlK9rPNbzsz8y5vG/ieUSGjoJfwCdfjD/OQtWeN99+W+ZwqwNLPi VweR6RdSPSguDgiGOrHfa7LLfrIfctHl7/Ps/VCjcQ1GM4+1CdQoI+fj31etUHtPw4ov PdCKXYSfad49Vm/PAdXR6W4snDYYMeYTScbrv4dC9bQrLcgo9o9hJjGXew04FyUpJvO+ xLqPVvkFgTRtbZ6ju7q6drxXDMYVH2qcLoRELr8dBNWKA4X57yGeH+f8Qjd826AdiE9a rOtA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=iPvMln8fETCvIb1O9zDTgMvwvAqRofofWlm0c6p2k1M=; b=X0hwCteS0iqfuvCVhRGQfz9kDrkFbeVqYZ7PZx1LvphwYHGJn06uUZBzJaFBTtWwFn gIzfWr/S1DPWl8HENKdncKsRZs8WpR0kWcJSuqAyDGytLaTc9thVVds1NsPk00Gaxx7W pKmE3tEw5Bz7Wn05u20jQr7/uoi1LFrAOjZHiqKZezCS9GTEXNL8fy4MJLbU7sMFK6+4 wE1kmjFPom6X7PhxLcmGn7kK5K2Ebps06FNjO/TJKlJ9gl6zV9vLEVdvxJUFnRClRg7D OACFpZaFIvpAEz5X97l4f/g7WGoK2Ca1l8k9J05IHrKKHsXc8jqi2L93OmUqHKq5a+K5 or7g== X-Gm-Message-State: AGi0PuYx5bSFMl1WblppIeXfwnwHzqlKVblfwwC2uBhrRpTP5CLPQirG IGF4OUsc/D5A9wsLQzcgAuwk5knFXl09eXkUDeqDPQ== X-Google-Smtp-Source: APiQypJ+DqbeC1O5KOyrpWyqx704axL30zwPYq7143oUeeXsMkdaCiq01Ps1n85YwDuFFgsTbC2lJqCPXxOu54bj/Ws= X-Received: by 2002:a37:4b0c:: with SMTP id y12mr19417043qka.43.1589278520977; Tue, 12 May 2020 03:15:20 -0700 (PDT) MIME-Version: 1.0 References: <000000000000dc82ac05a55f3005@google.com> In-Reply-To: From: Dmitry Vyukov Date: Tue, 12 May 2020 12:15:09 +0200 Message-ID: Subject: Re: INFO: task hung in do_read_cache_page (3) To: Mike Christie Cc: syzbot , Andrew Morton , Amir Goldstein , Jens Axboe , "Darrick J. Wong" , Jan Kara , Josef Bacik , LKML , Linux-MM , syzkaller-bugs , william.kucharski@oracle.com, Matthew Wilcox Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 11, 2020 at 7:31 PM Mike Christie wrote: > > On 5/11/20 8:19 AM, syzbot wrote: > > syzbot has bisected this bug to: > > > > commit 2da22da573481cc4837e246d0eee4d518b3f715e > > Author: Mike Christie > > Date: Tue Aug 13 16:39:52 2019 +0000 > > > > nbd: fix zero cmd timeout handling v2 > > > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=11d6ab14100000 > > start commit: e99332e7 gcc-10: mark more functions __init to avoid secti.. > > git tree: upstream > > final crash: https://syzkaller.appspot.com/x/report.txt?x=13d6ab14100000 > > console output: https://syzkaller.appspot.com/x/log.txt?x=15d6ab14100000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=8a96cf498e199d8b > > dashboard link: https://syzkaller.appspot.com/bug?extid=518c54e255b5031adde4 > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=146e45ec100000 > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=164444a4100000 > > > > Reported-by: syzbot+518c54e255b5031adde4@syzkaller.appspotmail.com > > Fixes: 2da22da57348 ("nbd: fix zero cmd timeout handling v2") > > > > For information about bisection process see: https://goo.gl/tpsmEJ#bisection > > > > How do you adjust/modify what is expected from the test or what is > reported as an error? > > The patch added back behavior that got removed. With the patch we expect > the hung task warnings, because we specifically want to hold onto > running commands for longer than 120/hung_task_timeout seconds Hi Mike, All task hung messages are considered a kernel bug. So far this was always true as far as I can tell. Tasks that are blocked for any prolonged period should be killable.