From mboxrd@z Thu Jan  1 00:00:00 1970
From: Tejun Heo <teheo-l3A5Bk7waGM@public.gmane.org>
Subject: Re: [PATCH 2/4] sysfs: Implement sysfs manged shadow
	directory	support.
Date: Tue, 31 Jul 2007 12:41:45 +0900
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To: "Eric W. Biederman" <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
Cc: Linux Containers <containers-qjLDD68F18O7TbgM5vRIOg@public.gmane.org>, Greg KH <greg-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org>, Greg KH <gregkh-l3A5Bk7waGM@public.gmane.org>, Dave Hansen <hansendc-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
List-Id: containers.vger.kernel.org

Hello,

Eric W. Biederman wrote:
> Ugh.  I need to step back and carefully define what I'm seeing but it
> looks like the current sysfs locking is wrong.
> 
> I'm starting to find little inconsistencies all over the place
> such as:
> 
> Which lock actually protects sd->s_children?
> - It isn't sysfs_mutex.  (see sysfs_lookup)
> - It isn't inode->i_mutex (we only get it if we happen to have the inode
>   in core)

Yeah, I missed two places while converting to sysfs_mutex.
sysfs_lookup() and rename().  I'm about to post patch to fix it.

> At first glance sysfs_assoc_lock looks just as bad.

I think sysfs_assoc_lock is okay.  It's tricky tho.  Why do you think
it's bad?

-- 
tejun