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From: ebiederm@xmission.com (Eric W. Biederman)
To: Mike Galbraith <efault@gmx.de>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Oleg Nesterov <oleg@redhat.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Pavel Emelyanov <xemul@parallels.com>,
	Cyrill Gorcunov <gorcunov@openvz.org>,
	Louis Rilling <louis.rilling@kerlabs.com>
Subject: Re: [PATCH]  Re: [RFC PATCH] namespaces: fix leak on fork() failure
Date: Fri, 04 May 2012 01:03:36 -0700	[thread overview]
Message-ID: <m1sjfggyp3.fsf@fess.ebiederm.org> (raw)
In-Reply-To: <1336057018.8119.46.camel@marge.simpson.net> (Mike Galbraith's message of "Thu, 03 May 2012 16:56:58 +0200")

Mike Galbraith <efault@gmx.de> writes:

> On Thu, 2012-05-03 at 05:12 +0200, Mike Galbraith wrote: 
>> On Tue, 2012-05-01 at 13:42 -0700, Andrew Morton wrote:
>> > On Tue, 01 May 2012 13:35:03 -0700
>> > ebiederm@xmission.com (Eric W. Biederman) wrote:
>> > 
>> > > 
>> > > Andrew can you please pick up this patch?
>> > 
>> > Sure.  I assume it's fixing a post-3.4 regression?  No -stable backport
>> > needed?
>> 
>> Dunno what all should go to stable, but anyone using vsftpd will
>> appreciate something going.  Large leakage was initially reported
>> against 3.1.  That was bisected to..
>> 423e0ab0 VFS : mount lock scalability for internal mounts 
>> 
>> Subsequent fixes which did not go to stable were applied..
>> 	905ad269 procfs: fix a vfsmount longterm reference leak
>> 	6f686574 ... and the same kind of leak for mqueue
>> ..but leakage persists even with fork failure hole plugged.
>
>> Whatever goes to stable, what fixes this little bugger should go too.
>
> Finally have a decent trace, patch to fix the problem below.
>
> marge:~ # grep 0xffff8801fad5dff0 /trace3
>           vsftpd-18277 [003] ....  1779.012239: proc_set_super: get_pid_ns: 0xffff8801fad5dff0 count:1->2
>           vsftpd-18277 [003] ....  1779.012253: create_pid_namespace: create_pid_namespace: 0xffff8801fad5dff0
>           vsftpd-18277 [003] ....  1779.012258: alloc_pid: get_pid_ns: 0xffff8801fad5dff0 count:2->3
>           vsftpd-18277 [003] ....  1779.012278: proc_kill_sb: put_pid_ns: 0xffff8801fad5dff0 count:3->2
>      ksoftirqd/3-16    [003] ..s.  1779.012731: delayed_put_pid: put_pid_ns: 0xffff8801fad5dff0 count:2->1
>           vsftpd-18277 [003] ....  1779.015614: destroy_pid_namespace: destroy_pid_namespace: 0xffff8801fad5dff0
>           vsftpd-18277 [003] ....  1779.015614: free_nsproxy: put_pid_ns: 0xffff8801fad5dff0 count:1->0
>           vsftpd-18277 [003] ....  1779.249871: proc_set_super: get_pid_ns: 0xffff8801fad5dff0 count:1->2
>           vsftpd-18277 [003] ....  1779.249884: create_pid_namespace: create_pid_namespace: 0xffff8801fad5dff0
>           vsftpd-18277 [003] ....  1779.249888: alloc_pid: get_pid_ns: 0xffff8801fad5dff0 count:2->3
>           vsftpd-18351 [003] ....  1779.256337: switch_task_namespaces: exiting: 0xffff8801fad5dff0 count:3
>           vsftpd-18351 [003] ....  1779.266243: free_nsproxy: put_pid_ns: 0xffff8801fad5dff0 count:3->2
> <insert>
>               ps-18381 [000] ....  1779.298798: proc_fill_cache <-proc_pid_readdir
>               ps-18381 [000] ....  1779.298802: proc_pid_instantiate <-proc_fill_cache
>               ps-18381 [000] ....  1779.298802: proc_pid_make_inode <-proc_pid_instantiate
>               ps-18381 [000] ....  1779.298802: proc_alloc_inode <-alloc_inode
>               ps-18381 [000] ....  1779.298807: get_task_pid <-proc_pid_make_inode
>               ps-18381 [000] ....  1779.298807: get_pid <-get_task_pid
> </insert> ditto for other pid references added post task exit
>               ps-18381 [000] ....  1779.298807: get_pid: pid: 0xffff8802031a2fc0 namespace: 0xffff8801fad5dff0 pid count:1->2 pid_ns count:2
>               ps-18381 [001] ....  1779.327593: get_pid: pid: 0xffff8802031a2fc0 namespace: 0xffff8801fad5dff0 pid count:2->3 pid_ns count:2
>               ps-18381 [001] ....  1779.327653: get_pid: pid: 0xffff8802031a2fc0 namespace: 0xffff8801fad5dff0 pid count:3->4 pid_ns count:2
>               ps-18381 [001] ....  1779.327716: get_pid: pid: 0xffff8802031a2fc0 namespace: 0xffff8801fad5dff0 pid count:4->5 pid_ns count:2
>               ps-18381 [001] ....  1779.327804: get_pid: pid: 0xffff8802031a2fc0 namespace: 0xffff8801fad5dff0 pid count:5->6 pid_ns count:2
>               ps-18381 [001] ....  1779.327817: get_pid: pid: 0xffff8802031a2fc0 namespace: 0xffff8801fad5dff0 pid count:6->7 pid_ns count:2
>               ps-18381 [001] ....  1779.327818: put_pid: pid: 0xffff8802031a2fc0 namespace: 0xffff8801fad5dff0 pid count:7->6 pid_ns count:2
>           vsftpd-18277 [003] ....  1779.358887: put_pid: pid: 0xffff8802031a2fc0 namespace: 0xffff8801fad5dff0 pid count:6->5 pid_ns count:2
>           vsftpd-18277 [003] ....  1779.358889: put_pid: pid: 0xffff8802031a2fc0 namespace: 0xffff8801fad5dff0 pid count:5->4 pid_ns count:2
>           vsftpd-18277 [003] ....  1779.358891: put_pid: pid: 0xffff8802031a2fc0 namespace: 0xffff8801fad5dff0 pid count:4->3 pid_ns count:2
>           vsftpd-18277 [003] ....  1779.358894: put_pid: pid: 0xffff8802031a2fc0 namespace: 0xffff8801fad5dff0 pid count:3->2 pid_ns count:2
>           vsftpd-18277 [003] ....  1779.358897: put_pid: pid: 0xffff8802031a2fc0 namespace: 0xffff8801fad5dff0 pid count:2->1 pid_ns count:2
>           vsftpd-18277 [003] ....  1779.358918: proc_kill_sb: put_pid_ns: 0xffff8801fad5dff0 count:2->1
>               ps-18386 [001] ....  1779.370210: get_pid: pid: 0xffff8802031a2fc0 namespace: 0xffff8801fad5dff0 pid count:1->2 pid_ns count:1
>               ps-18386 [001] ....  1779.370240: get_pid: pid: 0xffff8802031a2fc0 namespace: 0xffff8801fad5dff0 pid count:2->3 pid_ns count:1
>               ps-18386 [001] ....  1779.370300: get_pid: pid: 0xffff8802031a2fc0 namespace: 0xffff8801fad5dff0 pid count:3->4 pid_ns count:1
>               ps-18386 [001] ....  1779.370361: get_pid: pid: 0xffff8802031a2fc0 namespace: 0xffff8801fad5dff0 pid count:4->5 pid_ns count:1
>               ps-18386 [001] ....  1779.370454: get_pid: pid: 0xffff8802031a2fc0 namespace: 0xffff8801fad5dff0 pid count:5->6 pid_ns count:1
>               ps-18386 [001] ....  1779.370467: get_pid: pid: 0xffff8802031a2fc0 namespace: 0xffff8801fad5dff0 pid count:6->7 pid_ns count:1
>               ps-18386 [001] ....  1779.370468: put_pid: pid: 0xffff8802031a2fc0 namespace: 0xffff8801fad5dff0 pid count:7->6 pid_ns count:1
>      ksoftirqd/3-16    [003] ..s.  1779.390717: delayed_put_pid: pid: 0xffff8802031a2fc0 LEAKED namespace: 0xffff8801fad5dff0
>
> Ok, that seems reasonable.
>
> Create > 27k "leaked" namespaces, watch many thousands go away over
> time.. but many hundred persist and persist and persist.
>
> Hm.  echo 3 > /proc/sys/vm/drop_caches.. *poof gone*

Good to hear.  I am sad to hear that proc_flush_task isn't doing a
better job but at least memory pressure will now free everything up as
it is supposed to.

> Grr.  I wonder who is doing the pinning when I don't monitor, but..
>
> <patch>
> kick kick kick... it's dead Jim.
> </patch>

Are you saying all known bugs are fixed?  Thanks for digging into this
by the way.  A fresh set of eyeballs is always nice.

Eric

  parent reply	other threads:[~2012-05-04  7:59 UTC|newest]

Thread overview: 69+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-04-28  9:19 Mike Galbraith
2012-04-28 14:26 ` Oleg Nesterov
2012-04-29  4:13   ` Mike Galbraith
2012-04-29  7:57   ` Eric W. Biederman
2012-04-29  9:49     ` Mike Galbraith
2012-04-29 16:58     ` Oleg Nesterov
2012-04-30  2:59       ` Eric W. Biederman
2012-04-30  3:25         ` Mike Galbraith
2012-05-02 12:40         ` Oleg Nesterov
2012-05-02 17:37           ` Eric W. Biederman
2012-04-30  3:01       ` [PATCH] " Mike Galbraith
     [not found]         ` <m1zk9rmyh4.fsf@fess.ebiederm.org>
2012-05-01 20:42           ` Andrew Morton
2012-05-03  3:12             ` Mike Galbraith
2012-05-03 14:56               ` Mike Galbraith
2012-05-04  4:27                 ` Mike Galbraith
2012-05-04  7:55                   ` Eric W. Biederman
2012-05-04  8:34                     ` Mike Galbraith
2012-05-04  9:45                     ` Mike Galbraith
2012-05-04 14:13                       ` Eric W. Biederman
2012-05-04 14:49                         ` Mike Galbraith
2012-05-04 15:36                           ` Eric W. Biederman
2012-05-04 16:57                             ` Mike Galbraith
2012-05-04 20:29                               ` Eric W. Biederman
2012-05-05  5:56                                 ` Mike Galbraith
2012-05-05  6:08                                   ` Mike Galbraith
2012-05-05  7:12                                     ` Mike Galbraith
2012-05-05 11:37                                       ` Eric W. Biederman
2012-05-07 21:51                                       ` [PATCH] vfs: Speed up deactivate_super for non-modular filesystems Eric W. Biederman
2012-05-07 22:17                                         ` Al Viro
2012-05-07 23:56                                           ` Paul E. McKenney
2012-05-08  1:07                                             ` Eric W. Biederman
2012-05-08  4:53                                               ` Mike Galbraith
2012-05-09  7:55                                               ` Nick Piggin
2012-05-09 11:02                                                 ` Eric W. Biederman
2012-05-15  8:40                                                   ` Nick Piggin
2012-05-16  0:34                                                     ` Eric W. Biederman
2012-05-09 13:59                                                 ` Paul E. McKenney
2012-05-04  8:03                 ` Eric W. Biederman [this message]
2012-05-04  8:19                   ` [PATCH] Re: [RFC PATCH] namespaces: fix leak on fork() failure Mike Galbraith
2012-05-04  8:54                     ` Mike Galbraith
2012-05-07  0:32             ` [PATCH 0/3] pidns: Closing the pid namespace exit race Eric W. Biederman
2012-05-07  0:33               ` [PATCH 1/3] pidns: Use task_active_pid_ns in do_notify_parent Eric W. Biederman
2012-05-07  0:35               ` [PATCH 2/3] pidns: Guarantee that the pidns init will be the last pidns process reaped Eric W. Biederman
2012-05-08 22:50                 ` Andrew Morton
2012-05-16 18:39                 ` Oleg Nesterov
2012-05-16 19:34                   ` Oleg Nesterov
2012-05-16 20:54                   ` Eric W. Biederman
2012-05-17 17:00                     ` Oleg Nesterov
2012-05-17 21:46                       ` Eric W. Biederman
2012-05-18 12:39                         ` Oleg Nesterov
2012-05-19  0:03                           ` Eric W. Biederman
2012-05-21 12:44                             ` Oleg Nesterov
2012-05-22  0:16                               ` Eric W. Biederman
2012-05-22  0:20                               ` [PATCH] pidns: Guarantee that the pidns init will be the last pidns process reaped. v2 Eric W. Biederman
2012-05-22 16:54                                 ` Oleg Nesterov
2012-05-22 19:23                                 ` Andrew Morton
2012-05-23 14:52                                   ` Oleg Nesterov
2012-05-25 15:15                                     ` [PATCH -mm] pidns-guarantee-that-the-pidns-init-will-be-the-last-pidns-process-r eaped-v2-fix-fix Oleg Nesterov
2012-05-25 15:59                                       ` [PATCH -mm 0/1] pidns: find_new_reaper() can no longer switch to init_pid_ns.child_reaper Oleg Nesterov
2012-05-25 16:00                                         ` [PATCH -mm 1/1] " Oleg Nesterov
2012-05-25 21:43                                           ` Eric W. Biederman
2012-05-27 19:10                                             ` [PATCH v2 -mm 0/1] " Oleg Nesterov
2012-05-27 19:11                                               ` [PATCH v2 -mm 1/1] " Oleg Nesterov
2012-05-29  6:34                                                 ` Eric W. Biederman
2012-05-25 21:25                                       ` [PATCH -mm] pidns-guarantee-that-the-pidns-init-will-be-the-last-pidns-process-r eaped-v2-fix-fix Eric W. Biederman
2012-05-27 18:41                                         ` [PATCH -mm v2] " Oleg Nesterov
2012-05-07  0:35               ` [PATCH 3/3] pidns: Make killed children autoreap Eric W. Biederman
2012-05-08 22:51                 ` Andrew Morton
2012-04-30 13:57 ` [RFC PATCH] namespaces: fix leak on fork() failure Mike Galbraith

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