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=-10.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 7ABFDC3A5A7 for ; Wed, 4 Sep 2019 06:46:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 57FBC22CF5 for ; Wed, 4 Sep 2019 06:46:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728666AbfIDGq2 (ORCPT ); Wed, 4 Sep 2019 02:46:28 -0400 Received: from mga09.intel.com ([134.134.136.24]:6670 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727787AbfIDGq2 (ORCPT ); Wed, 4 Sep 2019 02:46:28 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Sep 2019 23:46:27 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,465,1559545200"; d="scan'208";a="383355312" Received: from xsang-optiplex-9020.sh.intel.com (HELO xsang-OptiPlex-9020) ([10.239.159.135]) by fmsmga006.fm.intel.com with ESMTP; 03 Sep 2019 23:46:25 -0700 Date: Wed, 4 Sep 2019 14:52:40 +0800 From: Oliver Sang To: Al Viro Cc: kernel test robot , linux-fsdevel@vger.kernel.org, lkp@01.org, LKML Subject: Re: [LKP] [fs/namei.c] e013ec23b8: WARNING:at_fs/dcache.c:#dentry_free Message-ID: <20190904065240.GQ22468@xsang-OptiPlex-9020> References: <20190831130917.ea4yx4uo5uttxk6l@inn2.lkp.intel.com> <20190831154246.GY1131@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190831154246.GY1131@ZenIV.linux.org.uk> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Aug 31, 2019 at 04:42:46PM +0100, Al Viro wrote: > On Sat, Aug 31, 2019 at 09:09:17PM +0800, kernel test robot wrote: > > > [ 13.886602] WARNING: CPU: 0 PID: 541 at fs/dcache.c:338 dentry_free+0x7f/0x90 > > [ 13.889208] Modules linked in: > > [ 13.890276] CPU: 0 PID: 541 Comm: readlink Not tainted 5.3.0-rc1-00008-ge013ec23b8231 #1 > > [ 13.892699] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 > > [ 13.895419] RIP: 0010:dentry_free+0x7f/0x90 > > [ 13.896739] Code: f0 75 cb 48 8d be b0 00 00 00 48 83 c4 08 48 c7 c6 60 8d cd a5 e9 51 69 e4 ff 48 89 3c 24 48 c7 c7 f8 a9 cb a6 e8 7f 37 e3 ff <0f> 0b 48 8b 34 24 eb 8f 66 0f 1f 84 00 00 00 00 00 66 66 66 66 90 > > [ 13.901957] RSP: 0018:ffffb5524063fe38 EFLAGS: 00010282 > > [ 13.903527] RAX: 0000000000000024 RBX: ffff9941878040c0 RCX: ffffffffa706aa08 > > [ 13.905566] RDX: 0000000000000000 RSI: 0000000000000096 RDI: 0000000000000246 > > [ 13.907612] RBP: 0000000000000000 R08: 0000000000000280 R09: 0000000000000033 > > [ 13.909664] R10: 0000000000000000 R11: ffffb5524063fce8 R12: ffff994187804118 > > [ 13.911711] R13: ffff99427a810000 R14: ffff994187d7c8f0 R15: ffff99427a810b80 > > [ 13.913753] FS: 0000000000000000(0000) GS:ffff9942bfc00000(0000) knlGS:0000000000000000 > > [ 13.916187] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 > > [ 13.917892] CR2: 000000000937458b CR3: 000000006800a000 CR4: 00000000000006f0 > > [ 13.919925] Call Trace: > > [ 13.920840] __dentry_kill+0x13c/0x1a0 > > [ 13.922076] path_put+0x12/0x20 > > [ 13.923148] free_fs_struct+0x1b/0x30 > > [ 13.924346] do_exit+0x304/0xc40 > > [ 13.925438] ? __schedule+0x25d/0x670 > > [ 13.926642] do_group_exit+0x3a/0xa0 > > [ 13.927817] __ia32_sys_exit_group+0x14/0x20 > > [ 13.929160] do_fast_syscall_32+0xa9/0x340 > > [ 13.930565] entry_SYSENTER_compat+0x7f/0x91 > > [ 13.931924] ---[ end trace 02c6706eb2c2ebf2 ]--- > > > > > > To reproduce: > > > > # build kernel > > cd linux > > cp config-5.3.0-rc1-00008-ge013ec23b8231 .config > > make HOSTCC=gcc-7 CC=gcc-7 ARCH=x86_64 olddefconfig prepare modules_prepare bzImage > > > > git clone https://github.com/intel/lkp-tests.git > > cd lkp-tests > > bin/lkp qemu -k job-script # job-script is attached in this email > > Can't reproduce here... any detail failure by using this reproducer? > > I see one potential problem in there, but I would expect it to have the > opposite effect (I really don't believe that it's a ->d_count wraparound - > that would've taken much longer than a minute, if nothing else). > > How reliably is it reproduced on your setup and does the following have > any impact, one way or another? It is always reproduced. We noticed that your branch was rebased. If it's still with problem, will let you know. > > diff --git a/fs/namei.c b/fs/namei.c > index 412479e4c258..671c3c1a3425 100644 > --- a/fs/namei.c > +++ b/fs/namei.c > @@ -643,10 +643,8 @@ static bool legitimize_root(struct nameidata *nd) > { > if (!nd->root.mnt || (nd->flags & LOOKUP_ROOT)) > return true; > - if (unlikely(!legitimize_path(nd, &nd->root, nd->root_seq))) > - return false; > nd->flags |= LOOKUP_ROOT_GRABBED; > - return true; > + return legitimize_path(nd, &nd->root, nd->root_seq); > } > > /* > _______________________________________________ > LKP mailing list > LKP@lists.01.org > https://lists.01.org/mailman/listinfo/lkp