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=-10.5 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 40EABC433E2 for ; Thu, 16 Jul 2020 06:21:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B2252067D for ; Thu, 16 Jul 2020 06:21:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=gmx.net header.i=@gmx.net header.b="ID6ZeBkk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728071AbgGPGVl (ORCPT ); Thu, 16 Jul 2020 02:21:41 -0400 Received: from mout.gmx.net ([212.227.17.20]:34879 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725921AbgGPGVk (ORCPT ); Thu, 16 Jul 2020 02:21:40 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1594880493; bh=bvG4L+GRdcY5Dl4MBmV11qNmb7GDZfxfN39c22H7JR0=; h=X-UI-Sender-Class:Subject:To:Cc:References:From:Date:In-Reply-To; b=ID6ZeBkknLEKmhg9YvqKnMZZVZJ1wUqENrhfzNNwG1arjWAaAheTuMpz/7je2hO3u 7IeiI3BLT8mgvV8EMoiHmecTQGbD9+zM+n/JSUDaZLOsAUN0Y8N3ewAr2pvBOEmmV9 SnOtfkYVe1qKk3vxr0KwXEr+8NMNaI3oL0nDt/8g= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([149.28.201.231]) by mail.gmx.com (mrgmx105 [212.227.17.174]) with ESMTPSA (Nemesis) id 1MNbkp-1kEqu60XWN-00P1tB; Thu, 16 Jul 2020 08:21:33 +0200 Subject: Re: [PATCH v2 2/2] btrfs: qgroup: add sysfs interface for debug To: Chris Down Cc: Qu Wenruo , linux-btrfs@vger.kernel.org, kernel-team@fb.com References: <20200715134931.GA2140@chrisdown.name> <20200716004031.GC2140@chrisdown.name> From: Qu Wenruo Autocrypt: addr=quwenruo.btrfs@gmx.com; 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Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200716004031.GC2140@chrisdown.name> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:y4rwahg3IQnLZL/6lXvS9kFBB3x5Qe5O+Ed6LMWDbey2RQpredh f6rxNmUYwgQw3fiX7ZLJsfcpPwS6orLtqzF200rb2ta9I7DHTrjP8iysynjc3YZyslHEBqw XxMT5UqveDq+nflZfgSSnq4f3LG3kx2dQlfr08X8/723R4vGeKQWRZfucFeFJBuCjsOGXZb SYQrTZtE0TY+swhmXk6Eg== X-UI-Out-Filterresults: notjunk:1;V03:K0:wII+1h+5FCI=:8F20QdUENEjPhlBohbb+R6 EqCznEiOsXWYIgn7N/Ij78rplN1IpOvbjD7650I+7Uup4s5jbgzlY8f6QjtZzPYjLWxJmCu9l uBbhg4PwMkN7mnWQZJsyn5i85G2oC2k794KGeSG8ylaIRAJicfwlgLnIasJbYPhjc1BqDT4Wi qqFprMh5zsS3PhOHV4ZWELjgZP2BcvarDefBArcCYb38hcAa/HVTgETJnUCDX/G5MZr/YagtL UWIStVppRTE6jrGzPLv6B2eA/6FTG6qvjM0lKdyMrHv1DXNbyuaTccX06ZojxSq3elkiKnFb2 lTmZuCzALoqhYL+oFLGzD5snb/N0ATiNElhQhOwFNX3G1iaF8j5UJK6E00Sf4GLM/LyDNHPxb mwEgP3foya+lZcfOpZgDrCaCwOCp73YEkdtB0esFW7GxcdKIKbz6PsvTGEcRGT6oiQDIk1qSj G8TjRrs6Dwxe69AaOUHaueVPeU5k3CO3G71VpXuy3B7I5v9nnJmTFblvscQAaM/DuIVeaMVfn rBPFrFoQciJCPQyn7N98xChIe2X7DdJgU2jhTP35skKGBu4X3Ov2k5stceMF7LaVg6NaDmNdH OX5aS1uG27/P/Aalffu89MZ1ihGPIAqUYTJuOqKyyCvsjbzFDp1X35iyINXyPVbCu3vjIfmUv DMgLiVyNvLzFyP7KTOgo5ZW/6iz6ifW1/GZhcgpGiloeeJdi5w4Sl6rLLviSK5+MTGeUNskK1 1z0OjQqHlZbp20xlhm2zweEFvzIqAGnD/l7wRYXeW5zEctxI04RdmgTCa6Z1NZeYcQ12d7w6G UUhVQMUuBu88mlwZiTGv0mLsuejO/2oGLZ7nhECeKp6bqCK7MKSmZlu+sVknNiVHenXNFP6Ah 7JOv+PcEpZ9wIFX5hOCthc7FYRruqbrSPT5c2FFb+2KrpaQti7umIMnhT+5zrxmilncVqB+/k m9RWb7HYBM3MxytBCGmbnkgNo35Ga6nsB6uteIGVFTi8qWrRCoBDy0VtAEhXh5uloS+LR9qAP 1KM0sqTZtVSX0YdX+GBZcjauwsbzpWRzL0F9TQJsvZXGKF0KosCkZNdkq4Be1LuVg0llgNLJ7 6Rm4MMlrklFyGfE61b30rEhugjuRb6iEpDHOTw1e47Gj3bIxbDiI8TmQ3bclU4QXIetaYu1nl 9p71Nc1p5qH7nZxlZ9YuroV4t4anaddSeKVxy/0mrdJtUOsE+lxnOpmo1cgWX/gOIJwZ/Ed6u 2H5r+IMg8Y/jJ61Un7hsoFYntV0hAKdu8Ht0EFQ== Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 2020/7/16 =E4=B8=8A=E5=8D=888:40, Chris Down wrote: > Qu Wenruo writes: >> Would you please provide the full call trace (especially the address >> causing the NULL pointer deref) and the reproducer (if possible)? > > I'll try to reproduce it again when I have time. I didn't have kdump > set, and am not currently running linux-next, so until then, you can > have this crappy photo that I rushed to take earlier before panic=3D30 > took effect :-) The linux-next is using an older version of that patch, which has a bad memory allocation inside atomic critical section. If you're unlucky enough, it could cause various weird bugs. Thankfully, David has exposed it and the latest version in btrfs tree should have it fixed. If you're uncertain if that's the case, feel free to try the latest misc-next branch to see if it's fixed. https://github.com/kdave/btrfs-devel/tree/misc-next Thanks for your report, Qu