From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757441Ab1ANCsN (ORCPT ); Thu, 13 Jan 2011 21:48:13 -0500 Received: from mx1.redhat.com ([209.132.183.28]:35963 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751576Ab1ANCsD (ORCPT ); Thu, 13 Jan 2011 21:48:03 -0500 Subject: Re: linux-next: lockdep whinge in cgroup_rmdir From: Eric Paris To: Valdis.Kletnieks@vt.edu Cc: Stephen Smalley , James Morris , Eric Paris , Paul Menage , linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, containers@lists.linux-foundation.org In-Reply-To: <12545.1294932849@localhost> References: <12545.1294932849@localhost> Content-Type: text/plain; charset="UTF-8" Date: Thu, 13 Jan 2011 21:47:20 -0500 Message-ID: <1294973240.18912.1.camel@localhost.localdomain> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2011-01-13 at 10:34 -0500, Valdis.Kletnieks@vt.edu wrote: > Seen booting yesterday's linux-next, was not present in 2.6.37-rc7-mmotm1202. > > Not sure if it's an selinux or cgroup issue, so I'm throwing it at every > address I can find for either. This is easily replicatable and happens at > every boot, so I can test patches if needed. Am willing to bisect it down if > nobody knows right off the bat what the problem is. Not an SELinux issue. selinux_inode_rmdir() on the stack trace is just left over junk. The vfs doesn't call into the filesystem rmdir code (cgroup_rmdir()) until after the selinux code has already returned. So cgroup people, you might as well pretend that wasn't on the stack trace at all. -Eric > > The 'W' taint is from the already-reported kernel/workqueue.c worker_enter_idle issue. > > [ 85.100795] systemd[1]: readahead-replay.service: main process exited, code=exited, status=1 > [ 85.101530] > [ 85.101531] ============================================= > [ 85.101796] [ INFO: possible recursive locking detected ] > [ 85.102002] 2.6.37-next-20110111 #1 > [ 85.102009] --------------------------------------------- > [ 85.102009] systemd/1 is trying to acquire lock: > [ 85.102009] (&(&dentry->d_lock)->rlock){+.+...}, at: [] cgroup_rmdir+0x339/0x479 > [ 85.102009] > [ 85.102009] but task is already holding lock: > [ 85.102009] (&(&dentry->d_lock)->rlock){+.+...}, at: [] cgroup_rmdir+0x331/0x479 > [ 85.102009] > [ 85.102009] other info that might help us debug this: > [ 85.102009] 4 locks held by systemd/1: > [ 85.102009] #0: (&sb->s_type->i_mutex_key#14/1){+.+.+.}, at: [] do_rmdir+0x7d/0x121 > [ 85.102009] #1: (&sb->s_type->i_mutex_key#14){+.+.+.}, at: [] vfs_rmdir+0x4a/0xbe > [ 85.102009] #2: (cgroup_mutex){+.+.+.}, at: [] cgroup_rmdir+0x461/0x479 > [ 85.102009] #3: (&(&dentry->d_lock)->rlock){+.+...}, at: [] cgroup_rmdir+0x331/0x479 > [ 85.102009] > [ 85.102009] stack backtrace: > [ 85.102009] Pid: 1, comm: systemd Tainted: G W 2.6.37-next-20110111 #1 > [ 85.102009] Call Trace: > [ 85.102009] [] ? __lock_acquire+0x929/0xd4e > [ 85.102009] [] ? cgroup_clear_directory+0xff/0x131 > [ 85.102009] [] ? cgroup_clear_directory+0xff/0x131 > [ 85.102009] [] ? cgroup_rmdir+0x339/0x479 > [ 85.102009] [] ? lock_acquire+0x100/0x126 > [ 85.102009] [] ? cgroup_rmdir+0x339/0x479 > [ 85.102009] [] ? sub_preempt_count+0x35/0x48 > [ 85.102009] [] ? _raw_spin_lock+0x36/0x45 > [ 85.102009] [] ? cgroup_rmdir+0x339/0x479 > [ 85.102009] [] ? cgroup_rmdir+0x339/0x479 > [ 85.102009] [] ? autoremove_wake_function+0x0/0x34 > [ 85.102009] [] ? selinux_inode_rmdir+0x15/0x17 > [ 85.102009] [] ? vfs_rmdir+0x79/0xbe > [ 85.102009] [] ? do_rmdir+0xd0/0x121 > [ 85.102009] [] ? sysret_check+0x27/0x62 > [ 85.102009] [] ? trace_hardirqs_on_caller+0x117/0x13b > [ 85.102009] [] ? trace_hardirqs_on_thunk+0x3a/0x3f > [ 85.102009] [] ? sys_rmdir+0x11/0x13 > [ 85.102009] [] ? system_call_fastpath+0x16/0x1b > [ 85.268272] systemd[1]: readahead-collect.service: main process exited, code=exited, status=1 > > Any ideas? >