Re: [PATCH] vfs: Fix, simpliy and stop using d_dname for the /proc/*/ns/* files.

[Ivan Delalande <colona@arista.com>]

On Wed, May 20, 2015 at 05:05:30PM -0500, Eric W. Biederman wrote:
> Omar Sandoval <osandov@osandov.com> writes:
>> I'm attaching a minimal script that reproduces this on 4.1-rc4. I'm
>> taking a look, but Eric or Al will probably figure this out before I get
>> the chance :)
> 
> This works for me, can you confirm it works for you folks as well?

Yeah, your patch works with our setup and when running our initial
test-case as well. Thanks a lot Eric.

> From: "Eric W. Biederman" <ebiederm@xmission.com>
> Date: Wed, 20 May 2015 16:39:00 -0500
> Subject: [PATCH] vfs: Fix, simpliy and stop using d_dname for the /proc/*/ns/* files.
> 
> Now that these files are no longer in proc we can stop playing games
> with d_alloc_pseudo and d_dname.  This change causes a couple of user
> visible changes:
> 
> - Opening /proc/*/ns/* and then readlink on /proc/self/fd/N now sees a
>   prepended / in the filename.
> 
> - /proc/mountinfo now gives useful information on what is mounted.
> 
> - Bind mounting /proc/*/ns/*, opening the mounted file, removing the
>   bind mount, and readlink on /proc/self/fd/N now sees / (as it should)
>   instead of triggering a warning and a kernel stack backtrace from
>   prepend_path.
> 
> Cc: stable@vger.kernel.org
> Reported-by: Ivan Delalande <colona@arista.com>
> Reported-by: Omar Sandoval <osandov@osandov.com>
> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

Tested-by: Ivan Delalande <colona@arista.com>

-- 
Ivan "Colona" Delalande