From mboxrd@z Thu Jan  1 00:00:00 1970
From: ebiederm@xmission.com (Eric W. Biederman)
Subject: Re: [PATCH v2] fail dentry revalidation after namespace change
Date: Fri, 06 Jul 2012 02:51:02 -0700
Message-ID: <874npli5fd.fsf@xmission.com>
References: <1341565747-15374-1-git-send-email-glommer@parallels.com>
	<87hatli62r.fsf@xmission.com> <4FF6B37B.4040005@parallels.com>
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Cc: <linux-kernel@vger.kernel.org>, <netdev@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Greg Thelen <gthelen@google.com>,
	Serge Hallyn <serge.hallyn@canonical.com>,
	Tejun Heo <tj@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Glauber Costa <glommer@parallels.com>
Return-path: <linux-kernel-owner@vger.kernel.org>
In-Reply-To: <4FF6B37B.4040005@parallels.com> (Glauber Costa's message of
	"Fri, 6 Jul 2012 13:44:27 +0400")
Sender: linux-kernel-owner@vger.kernel.org
List-Id: netdev.vger.kernel.org

Glauber Costa <glommer@parallels.com> writes:

> On 07/06/2012 01:37 PM, Eric W. Biederman wrote:
>> Glauber Costa <glommer@parallels.com> writes:
>> 
>>> When we change the namespace tag of a sysfs entry, the associated dentry
>>> is still kept around. readdir() will work correctly and not display the
>>> old entries, but open() will still succeed, so will reads and writes.
>> 
>> Note reads and writes of file handles open before the move should
>> continue to work.
>
> Well, yes. But do you see it as a big problem?
>
> This can probably be fixed as well, but I foresee a big hackishness in
> the way =p

At the moment it looks like a feature.

The only reason we bounce between different instances of sysfs is
because of the unfortunate sysfs directory layout that we need
to remain compatible with.

But I don't see it making much of a difference either way.

Eric