From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932512Ab2F1GIM (ORCPT ); Thu, 28 Jun 2012 02:08:12 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:39484 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932476Ab2F1GIH (ORCPT ); Thu, 28 Jun 2012 02:08:07 -0400 Message-ID: <4FEBF4B7.2070105@huawei.com> Date: Thu, 28 Jun 2012 14:07:51 +0800 From: Li Zefan User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:11.0) Gecko/20120312 Thunderbird/11.0 MIME-Version: 1.0 To: "tj@kernel.org" CC: shyju pv , "linux-kernel@vger.kernel.org" , "cgroups@vger.kernel.org" , Sanil kumar , Masanari Iida Subject: Re: 3.5-rc3: BUG: Dentry still in use (1) [unmount of cgroup cgroup] References: <20120627182903.GP15811@google.com> In-Reply-To: <20120627182903.GP15811@google.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.166.88.115] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org tj@kernel.org wrote: > On Sun, Jun 24, 2012 at 07:08:07PM +0000, shyju pv wrote: >> Hi, >> Observed a crash on 3.5-rc3 with cgroup tests from LTP(Stable April,2012 release)on Dell Inspiron 1526[Intel(R) Core2Duo T7250, MEM 4GB] and also on another x86 quad core target(4GB RAM). >> LTP test case: cgroup_regression_test.sh(test 4,7 and 9 crashes randomly when the test cases are executed in order) I wrote thoese test scripts. ;) >> Shyju >> >> [ 532.805905] BUG: Dentry ffff8801164db490{i=491b,n=/} still in use (1) [unmount of cgroup cgrou > > Hmm... fa980ca87d "cgroup: superblock can't be released with active > dentries" is supposed to have fixed that. Looking into it. > I think I know what happened here: umount deativate_super(sb) dput(subdir) subdir->d_count-- d_release(subdir) deactivate_super(sb) shrink_dcache_for_umount(sb) BUG(root->d_count)!! root->d_count-- I use this script to reproduce the bug: mount -t cgroup -o cpu xxx /mnt mkdir /mnt/sub sleep 100 < /mnt/sub & kill $! wait $! rmdir /mnt/sub umount /mnt