From: ebiederm@xmission.com (Eric W. Biederman)
To: Gao feng <gaofeng@cn.fujitsu.com>
Cc: linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org
Subject: Re: [PATCH] namespace:unmount pid_namespace's proc_mnt when copy_net_ns failed
Date: Fri, 02 Nov 2012 01:54:14 -0700 [thread overview]
Message-ID: <87wqy4fkqx.fsf@xmission.com> (raw)
In-Reply-To: <5093773B.5010706@cn.fujitsu.com> (Gao feng's message of "Fri, 02 Nov 2012 15:33:15 +0800")
Gao feng <gaofeng@cn.fujitsu.com> writes:
> 于 2012年11月02日 15:02, Eric W. Biederman 写道:
>> Gao feng <gaofeng@cn.fujitsu.com> writes:
>>
>>> we should call pid_ns_release_proc to unmount pid_namespace's
>>> proc_mnt when copy_net_ns failed in function create_new_namespaces.
>>>
>>> otherwise,the proc_mnt will not be freed and because the super_block
>>> of proc_mnt also add the reference of the pid_namespace,so this
>>> pid_namespace will never be released too.
>>
>> Ouch!
>>
>> Have you encountered this failure in practice or is this just from
>> review?
>
> I add some printk in pid_ns_release_proc,it's not called in above case.
> when copy_net_ns failed,this pid_namespace is not used by any task,
> so proc_flush_task can't call pid_ns_release_proc to umount this pidns->proc_mnt.
> it's the only chance we can unmount this pindns->proc_mnt.
>
> With this patch,everything runs well.
I have reviewed the code and I don't doubt that this is necessary.
What caused you to look into this failure? Is there some semi-practical
real world case that someone is hitting?
Eric
next prev parent reply other threads:[~2012-11-02 8:54 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-02 0:38 [PATCH] namespace:unmount pid_namespace's proc_mnt when copy_net_ns failed Gao feng
2012-11-02 7:02 ` Eric W. Biederman
2012-11-02 7:33 ` Gao feng
2012-11-02 8:54 ` Eric W. Biederman [this message]
2012-11-02 9:02 ` Gao feng
2012-11-02 9:10 ` Eric W. Biederman
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87wqy4fkqx.fsf@xmission.com \
--to=ebiederm@xmission.com \
--cc=containers@lists.linux-foundation.org \
--cc=gaofeng@cn.fujitsu.com \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox