From: Oleg Nesterov <oleg@redhat.com>
To: Andrew Morton <akpm@linux-foundation.org>,
Pavel Emelyanov <xemul@openvz.org>,
Linux Containers <containers@lists.osdl.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] procfs: Do not release pid_ns->proc_mnt too early
Date: Fri, 18 Jun 2010 13:15:54 +0200 [thread overview]
Message-ID: <20100618111554.GA3252@redhat.com> (raw)
In-Reply-To: <20100618082033.GD16877@hawkmoon.kerlabs.com>
On 06/18, Louis Rilling wrote:
>
> On 17/06/10 23:20 +0200, Oleg Nesterov wrote:
> > On 06/16, Louis Rilling wrote:
> > >
> > > Detached tasks are not seen by zap_pid_ns_processes()->sys_wait4(), so
> > > that release_task()->proc_flush_task() of container init can be called
> > > before it is for some detached tasks in the namespace.
> > >
> > > Pin proc_mnt's in copy_process(), so that proc_flush_task() becomes safe
> > > whatever the ordering of tasks.
> >
> > I must have missed something, but can't we just move mntput() ?
>
> See the log of the commit introducing pid_ns_release_proc() (6f4e6433):
>
> Sice the namespace holds the vfsmnt, vfsmnt holds the superblock and the
> superblock holds the namespace we must explicitly break this circle to destroy
> all the stuff. This is done after the init of the namespace dies.
I see thanks.
Besides, put_pid_ns() can be called in any context...
Oleg.
next prev parent reply other threads:[~2010-06-18 11:15 UTC|newest]
Thread overview: 98+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-16 16:34 [PATCH] procfs: Do not release pid_ns->proc_mnt too early Louis Rilling
[not found] ` <1276706068-18567-1-git-send-email-louis.rilling-aw0BnHfMbSpBDgjK7y7TUQ@public.gmane.org>
2010-06-17 9:53 ` Pavel Emelyanov
2010-06-17 9:53 ` Pavel Emelyanov
2010-06-17 13:41 ` Eric W. Biederman
2010-06-17 14:20 ` Louis Rilling
2010-06-17 21:36 ` Oleg Nesterov
2010-06-18 8:27 ` Louis Rilling
2010-06-18 16:27 ` Oleg Nesterov
2010-06-21 11:11 ` Louis Rilling
2010-06-21 12:58 ` Eric W. Biederman
2010-06-21 14:15 ` Louis Rilling
2010-06-21 14:26 ` Eric W. Biederman
[not found] ` <20100618082738.GE16877-Hu8+6S1rdjywhHL9vcZdMVaTQe2KTcn/@public.gmane.org>
2010-06-18 16:27 ` Oleg Nesterov
2010-06-17 21:20 ` Oleg Nesterov
2010-06-18 8:20 ` Louis Rilling
2010-06-18 11:15 ` Oleg Nesterov [this message]
2010-06-18 16:08 ` Oleg Nesterov
2010-06-18 16:08 ` Oleg Nesterov
2010-06-18 17:33 ` Louis Rilling
2010-06-18 17:55 ` Oleg Nesterov
2010-06-18 17:55 ` Oleg Nesterov
2010-06-18 21:23 ` Oleg Nesterov
2010-06-18 21:23 ` Oleg Nesterov
2010-06-19 19:08 ` [PATCH 0/4] pid_ns_prepare_proc/unshare cleanups Oleg Nesterov
2010-06-19 19:09 ` [PATCH 1/4] procfs: proc_get_sb: consolidate/cleanup root_inode->pid logic Oleg Nesterov
2010-06-19 19:10 ` [PATCH 2/4] procfs: kill the global proc_mnt variable Oleg Nesterov
2010-06-19 19:10 ` [PATCH 3/4] procfs: move pid_ns_prepare_proc() from copy_process() to create_pid_namespace() Oleg Nesterov
2010-06-19 19:11 ` [PATCH RESEND 4/4] sys_unshare: simplify the not-really-implemented CLONE_THREAD/SIGHAND/VM code Oleg Nesterov
2010-06-20 8:42 ` [PATCH 0/6] Unshare support for the pid namespace Eric W. Biederman
2010-06-20 8:44 ` [PATCH 1/6] pid: Remove the child_reaper special case in init/main.c Eric W. Biederman
[not found] ` <m1ljaaqejm.fsf_-_-+imSwln9KH6u2/kzUuoCbdi2O/JbrIOy@public.gmane.org>
2010-06-20 18:29 ` Oleg Nesterov
2010-06-20 18:29 ` Oleg Nesterov
2010-06-20 20:27 ` Oleg Nesterov
2010-06-20 8:45 ` [PATCH 2/6] pidns: Call pid_ns_prepare_proc from create_pid_namespace Eric W. Biederman
[not found] ` <m1hbkyqeib.fsf_-_-+imSwln9KH6u2/kzUuoCbdi2O/JbrIOy@public.gmane.org>
2010-06-20 18:19 ` Oleg Nesterov
2010-06-20 18:19 ` Oleg Nesterov
2010-06-20 8:45 ` [PATCH 3/6] procfs: kill the global proc_mnt variable Eric W. Biederman
2010-06-20 8:47 ` [PATCH 4/6] pidns: Don't allow new pids after the namespace is dead Eric W. Biederman
2010-06-20 18:44 ` Oleg Nesterov
2010-06-20 8:48 ` [PATCH 5/6] pidns: Use task_active_pid_ns where appropriate Eric W. Biederman
2010-06-20 8:49 ` [PATCH 6/6] pidns: Support unsharing the pid namespace Eric W. Biederman
2010-06-20 20:14 ` Oleg Nesterov
2010-06-20 20:42 ` Oleg Nesterov
2010-06-21 1:53 ` Eric W. Biederman
2010-06-20 18:03 ` [PATCH 0/6] Unshare support for " Oleg Nesterov
2010-06-20 18:05 ` [PATCH 0/2] pid_ns_release_proc() fixes Oleg Nesterov
2010-06-20 18:06 ` [PATCH 1/2] pid_ns: move destroy_pid_namespace() into workqueue context Oleg Nesterov
2010-06-20 18:06 ` [PATCH 2/2] pid_ns: refactor the buggy pid_ns_release_proc() logic Oleg Nesterov
2010-06-20 21:00 ` [PATCH 0/6] Unshare support for the pid namespace Eric W. Biederman
2010-06-20 21:48 ` Oleg Nesterov
[not found] ` <m14ogxctd6.fsf-+imSwln9KH6u2/kzUuoCbdi2O/JbrIOy@public.gmane.org>
2010-06-20 21:56 ` Oleg Nesterov
2010-06-20 21:56 ` Oleg Nesterov
2011-01-26 15:57 ` Daniel Lezcano
2010-06-23 20:36 ` [PATCH 0/1] pid_ns: move pid_ns_release_proc() from proc_flush_task() to zap_pid_ns_processes() Oleg Nesterov
[not found] ` <20100623203652.GA25298-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2010-06-23 20:37 ` [PATCH 1/1] " Oleg Nesterov
2010-06-23 20:37 ` Oleg Nesterov
2010-06-24 6:36 ` Sukadev Bhattiprolu
2010-06-24 12:59 ` Oleg Nesterov
2010-06-24 7:06 ` Eric W. Biederman
2010-06-24 13:01 ` Oleg Nesterov
2010-06-24 8:37 ` [PATCH] pid_ns: Fix proc_flush_task() accessing freed proc_mnt Louis Rilling
2010-06-24 17:08 ` [RESEND PATCH] " Louis Rilling
2010-06-24 19:18 ` Oleg Nesterov
2010-06-25 10:23 ` Louis Rilling
[not found] ` <20100625102303.GG3773-Hu8+6S1rdjywhHL9vcZdMVaTQe2KTcn/@public.gmane.org>
2010-06-25 12:21 ` Oleg Nesterov
2010-06-25 12:21 ` Oleg Nesterov
2010-06-25 18:37 ` Sukadev Bhattiprolu
2010-06-25 18:37 ` Sukadev Bhattiprolu
2010-06-25 19:29 ` Oleg Nesterov
2010-06-25 21:26 ` Sukadev Bhattiprolu
2010-06-25 21:27 ` Oleg Nesterov
2010-06-25 22:07 ` Sukadev Bhattiprolu
2010-07-09 4:36 ` [RFC][PATCH 1/2] pidns: Add a flag to indicate a pid namespace is dead Eric W. Biederman
2010-07-09 4:39 ` [RFC][PATCH 2/2] pidns: Remove proc flush races when a pid namespaces are exiting Eric W. Biederman
2010-07-09 12:14 ` Louis Rilling
2010-07-09 13:05 ` Eric W. Biederman
2010-07-09 14:13 ` Louis Rilling
2010-07-09 15:58 ` [PATCH 01/24] pidns: Remove races by stopping the caching of proc_mnt Eric W. Biederman
2010-07-09 22:13 ` Serge E. Hallyn
2010-07-11 14:14 ` Louis Rilling
2010-07-11 14:25 ` Eric W. Biederman
2010-07-12 18:09 ` [PATCH] pidns: Fix wait for zombies to be reaped in zap_pid_ns_processes Eric W. Biederman
2010-07-13 21:42 ` Louis Rilling
2010-07-13 22:34 ` Serge E. Hallyn
[not found] ` <20100713214234.GA21042-Hu8+6S1rdjywhHL9vcZdMVaTQe2KTcn/@public.gmane.org>
2010-07-13 22:34 ` Serge E. Hallyn
2010-07-14 1:47 ` Eric W. Biederman
[not found] ` <m1oceakf5x.fsf-+imSwln9KH6u2/kzUuoCbdi2O/JbrIOy@public.gmane.org>
2010-10-30 7:07 ` Sukadev Bhattiprolu
2010-10-30 7:07 ` Sukadev Bhattiprolu
2010-07-14 20:53 ` Sukadev Bhattiprolu
2010-07-14 21:35 ` Eric W. Biederman
2010-06-21 11:09 ` [PATCH] procfs: Do not release pid_ns->proc_mnt too early Louis Rilling
2010-06-21 11:15 ` Louis Rilling
2010-06-21 14:38 ` Oleg Nesterov
-- strict thread matches above, loose matches on Subject: below --
2010-06-16 15:58 Louis Rilling
2010-06-16 15:58 ` Louis Rilling
2010-06-16 16:04 ` Pavel Emelyanov
2010-06-16 16:15 ` Louis Rilling
2010-06-16 16:16 ` Louis Rilling
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