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=-2.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 CD96EC432C0 for ; Tue, 26 Nov 2019 09:56:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9B7052075C for ; Tue, 26 Nov 2019 09:56:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=gmx.net header.i=@gmx.net header.b="ZG16Fsk1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727610AbfKZJ4f (ORCPT ); Tue, 26 Nov 2019 04:56:35 -0500 Received: from mout.gmx.net ([212.227.15.19]:57567 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727397AbfKZJ4f (ORCPT ); Tue, 26 Nov 2019 04:56:35 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1574762192; bh=VpvycKW78m8Tny68PRS337gHW3Qist9GghGv0ECx258=; h=X-UI-Sender-Class:Subject:From:To:References:Date:In-Reply-To; b=ZG16Fsk1upt6cEGbZqX+keSLj/sUyYswoejVdCpBn3Ow3Wo4ccjh2ykCYjmxlg/PG TuOvuAt7heacxN0u3z3Wiwwe6tbxD+nin48GXuDHpQkNSIFIGjIqlAMY5E+4b2yWX7 AziScnD/JnxhJUwKQey9g7DyNO5zeTL0HhLzscU4= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([13.231.109.76]) by mail.gmx.com (mrgmx005 [212.227.17.184]) with ESMTPSA (Nemesis) id 1MFKGZ-1ibyR43Zur-00FmkE; Tue, 26 Nov 2019 10:56:32 +0100 Subject: Re: btrfs/058 deadlock with lseek From: Qu Wenruo To: "linux-btrfs@vger.kernel.org" , Linux FS Devel , David Sterba References: <3310d598-bd2f-6024-e5ac-c1c6080c0fd7@gmx.com> Autocrypt: addr=quwenruo.btrfs@gmx.com; prefer-encrypt=mutual; keydata= mQENBFnVga8BCACyhFP3ExcTIuB73jDIBA/vSoYcTyysFQzPvez64TUSCv1SgXEByR7fju3o 8RfaWuHCnkkea5luuTZMqfgTXrun2dqNVYDNOV6RIVrc4YuG20yhC1epnV55fJCThqij0MRL 1NxPKXIlEdHvN0Kov3CtWA+R1iNN0RCeVun7rmOrrjBK573aWC5sgP7YsBOLK79H3tmUtz6b 9Imuj0ZyEsa76Xg9PX9Hn2myKj1hfWGS+5og9Va4hrwQC8ipjXik6NKR5GDV+hOZkktU81G5 gkQtGB9jOAYRs86QG/b7PtIlbd3+pppT0gaS+wvwMs8cuNG+Pu6KO1oC4jgdseFLu7NpABEB AAG0IlF1IFdlbnJ1byA8cXV3ZW5ydW8uYnRyZnNAZ214LmNvbT6JAU4EEwEIADgCGwMFCwkI BwIGFQgJCgsCBBYCAwECHgECF4AWIQQt33LlpaVbqJ2qQuHCPZHzoSX+qAUCXZw1oQAKCRDC PZHzoSX+qCY6CACd+mWu3okGwRKXju6bou+7VkqCaHTdyXwWFTsr+/0ly5nUdDtT3yEVggPJ 3VP70wjlrxUjNjFb6iIvGYxiPOrop1NGwGYvQktgRhaIhALG6rPoSSAhGNjwGVRw0km0PlIN D29BTj/lYEk+jVM1YL0QLgAE1AI3krihg/lp/fQT53wLhR8YZIF8ETXbClQG1vJ0cllPuEEv efKxRyiTSjB+PsozSvYWhXsPeJ+KKjFen7ebE5reQTPFzSHctCdPnoR/4jSPlnTlnEvLeqcD ZTuKfQe1gWrPeevQzgCtgBF/WjIOeJs41klnYzC3DymuQlmFubss0jShLOW8eSOOWhLRuQEN BFnVga8BCACqU+th4Esy/c8BnvliFAjAfpzhI1wH76FD1MJPmAhA3DnX5JDORcgaCbPEwhLj 1xlwTgpeT+QfDmGJ5B5BlrrQFZVE1fChEjiJvyiSAO4yQPkrPVYTI7Xj34FnscPj/IrRUUka 68MlHxPtFnAHr25VIuOS41lmYKYNwPNLRz9Ik6DmeTG3WJO2BQRNvXA0pXrJH1fNGSsRb+pK EKHKtL1803x71zQxCwLh+zLP1iXHVM5j8gX9zqupigQR/Cel2XPS44zWcDW8r7B0q1eW4Jrv 0x19p4P923voqn+joIAostyNTUjCeSrUdKth9jcdlam9X2DziA/DHDFfS5eq4fEvABEBAAGJ ATwEGAEIACYCGwwWIQQt33LlpaVbqJ2qQuHCPZHzoSX+qAUCXZw1rgUJCWpOfwAKCRDCPZHz oSX+qFcEB/95cs8cM1OQdE/GgOfCGxwgckMeWyzOR7bkAWW0lDVp2hpgJuxBW/gyfmtBnUai fnggx3EE3ev8HTysZU9q0h+TJwwJKGv6sUc8qcTGFDtavnnl+r6xDUY7A6GvXEsSoCEEynby 72byGeSovfq/4AWGNPBG1L61Exl+gbqfvbECP3ziXnob009+z9I4qXodHSYINfAkZkA523JG ap12LndJeLk3gfWNZfXEWyGnuciRGbqESkhIRav8ootsCIops/SqXm0/k+Kcl4gGUO/iD/T5 oagaDh0QtOd8RWSMwLxwn8uIhpH84Q4X1LadJ5NCgGa6xPP5qqRuiC+9gZqbq4Nj Message-ID: Date: Tue, 26 Nov 2019 17:56:27 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <3310d598-bd2f-6024-e5ac-c1c6080c0fd7@gmx.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="ecgI3Yf6QlNUfyBCjk8fhKB2vq3LAIImf" X-Provags-ID: V03:K1:KEJ314lmnLnvbhj0GOA4nthFUXJK0EKzltuElC2bQh/ZErhQt19 c8OG4hoL9+QE19ZmR8Ksf802kcrBScztGLDQeTOCmxSLolefG1+dHbj9RBX9aCOaX0oopf9 wXjrfUNq5N/B1sNDQ8ADZbZsJXEqizDOloPl0t2bI2oStqdSjY/oZYSeDV6ZN/V6TMSSRd0 pm0zJ8pzbhoZHayNJE3uw== X-UI-Out-Filterresults: notjunk:1;V03:K0:McVKMgu8IiE=:rQN+2H8u4JwtBj8EmAROPg VRmISAHVPFwKpnV4OyYKtDOHL8MMi8CrdqAVPwyVeyiv18JjbmxUjmGd4fVtnIYCJPYjS02Lt UR8Za+381qTF4ErB+zW9Tq4ypDvEQjcZYGsDy0Im55GmUHGYW+xYiRfL3EF9mzdWcvMHCWTT4 Jw8hxEgLSZdRtS6dIuHinwWAtroWQpRGtQ5x8ZFMIKCpR8EbUufaxDxQKiMiur0PQqb5cppE+ OM6qprl7SgMGgojKmHw4CnEl0NWYJUZVgjtarA+uxn8vF3PJhtWTTtizotuaXLoFPTJ6szK0R 0LJdymQ7oFrar87GtMayOAyHLy9GTRb1iAcZEjH07KLc1Yn1NrpsTOZ7lKiGB4vWKx3G47orf kgCgxv3Qhi1M0kccE3rcOnKCAXtk1l57vPHuog0l+yDqnjSO1DyNULIofE0TPJI7zLrGePjOK 82Ui3rh/s3alsnev9xHxmgEguF6ivwUQ/Zcjb9LCe9kKizytKH4Jwr59NEKvLLsoU7TzeTf1M R0Oj4mzjgN0/aeKOZUknNxMK3+otYOk1LkyK7lJdFp3dD6awGDc9pFzTWNjXgG/yEuol5AxN0 lQ8HdoSOvNuwK70nnZWrNy1/Lj4HjvAaHRG8dv4oUU15YUU322wGHfPJhUOiEBUcjz0ENlJDg SS8pXVurNrNA5r8W/v6fz6sv5lMAelHHech2rzkY5dZ2kXP15QAK1R2nb5E25J/0aRDIPz4TE fVLvEh3HqUYo6prIeAS6IbEqntKdDIcCNLI/PAC3nIuyYBadBG+VhSjYCOF8pBhN6GY86/Sx3 707l4+SxCObGuUrLPmQZx0HzUibXpnZrVYJyQPdZUztyiyUZ1UIK2txvm+e8L5ukPX8oB3QBF KM9PU220HnWmMEwW35chJL0wKHS3F1RrvzA0qTBxXS9/jCclGodnBaM0lqOpr7qhtaKOy95dQ RRzjuLYGHB8Bl+LNdBeZQgbQt3DRtV8MGAmK8LISuxMP6RAMeMDiRJL9C3+wFIXLmlmT5fLVD SGyYvsGPWlLJZ1LpIPixxCV5PqfQBqUMufk+VDuYEH6p0jXaZXjw/LumYbeD9RiVDtbL81is9 erW+Rr4iLEd9cy3ytE8pEKbaNp2eoUzG+/y7Y1x+Qaviu3Q2o+lNdQTe3wkSdWCnTk0JpGPHs X+2S7TPisCBxuzEDtRoP4fM5qcJkzuhDNRyiyowQS+LVEFo8vuOLqfLhVuRHIasI6ysll+8Sq sQ1kmd/9Y3AprreTIVmeLnWFRSiCNBkePN7l7255N739ZK6pLjVl09FMCKtI= Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --ecgI3Yf6QlNUfyBCjk8fhKB2vq3LAIImf Content-Type: multipart/mixed; boundary="E1ivtHTUZ01qqBxok0xP9IlNJ212PPRNe" --E1ivtHTUZ01qqBxok0xP9IlNJ212PPRNe Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 2019/11/26 =E4=B8=8B=E5=8D=884:17, Qu Wenruo wrote: > Hi guys, >=20 > Just got a reproducible error in btrfs/058. > The backtrace is completely in VFS territory, not btrfs related lock at= all: With the help of Nikolay and Johannes, the offending commit is pinned down to 0be0ee71816b ("vfs: properly and reliably lock f_pos in fdget_pos()"), and Linus will soon revert it. Not a big deal, but testers would have a much easier life using David's misc-5.5 (still based on v5.4-rc). And to David, would you please keep your misc-5.5 branch until the offending patch get reverted? Thanks, Qu > BTRFS info (device dm-5): checking UUID tree > sysrq: Show Blocked State > task PC stack pid father > rm D 0 560678 560445 0x00000000 > Call Trace: > __schedule+0x5c7/0xea0 > ? __sched_text_start+0x8/0x8 > ? lock_downgrade+0x380/0x380 > ? lock_contended+0x730/0x730 > ? debug_check_no_locks_held+0x60/0x60 > schedule+0x7b/0x170 > schedule_preempt_disabled+0x18/0x30 > __mutex_lock+0x481/0xc70 > ? __fdget_pos+0x7e/0x80 > ? mutex_trylock+0x190/0x190 > ? debug_lockdep_rcu_enabled+0x26/0x40 > ? kmem_cache_free+0x157/0x3b0 > ? putname+0x73/0x80 > ? __ia32_sys_rmdir+0x30/0x30 > ? __check_object_size+0x134/0x1e6 > mutex_lock_nested+0x1b/0x20 > ? mutex_lock_nested+0x1b/0x20 > __fdget_pos+0x7e/0x80 > ksys_lseek+0x1d/0xf0 > __x64_sys_lseek+0x43/0x50 > do_syscall_64+0x79/0xe0 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x7f7518e5652b > Code: Bad RIP value. > RSP: 002b:00007ffead7508e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000008 > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7518e5652b > RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000000 > RBP: 00007f7518f267e0 R08: 0000000000000001 R09: 0000000000000001 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 > R13: 0000000000000002 R14: 00007f7518f2be68 R15: 00007f7518f287e0 >=20 > Is this a known bug in VFS layer? >=20 > Thanks, > Qu >=20 --E1ivtHTUZ01qqBxok0xP9IlNJ212PPRNe-- --ecgI3Yf6QlNUfyBCjk8fhKB2vq3LAIImf Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEELd9y5aWlW6idqkLhwj2R86El/qgFAl3c9ssACgkQwj2R86El /qjrjQgAqVQz8K4bilA1qqBXVKdWaTmuSBjRzP5nslHwXErZHrEJNe6R9DUg//i6 EpsapiMI40dP7FTcXQAyDljWJrZW1IvIGaFIBJu/m87TdEpClJNDDCBVOg15LmpS O1rtQsCBi8ns75vTRslflAuBgqSwI8o3i371cVp2pmdugLFfOisSfXw2Sh7/TE6n HYIcU95MZy9HbvL1YSp4ia+dfw5RTcu3R/l806tw4qd7Z0Eja5v6Ah0VfbC9PQBD 8g8At9MWZyMZdeccnKl9jZgnyOIi1VY9L+qlpveE863Lce1cH5NHSxU+ThxTZqIc 3oyQ1he5KaGr4a4cv5yLJ04dNnqSUQ== =R3Is -----END PGP SIGNATURE----- --ecgI3Yf6QlNUfyBCjk8fhKB2vq3LAIImf--