Re: [PATCH v7 7/7] enable building user namespace with xfs

Serge E. Hallyn
2013-08-07T15:01:41Z

Gah, forgot to actually add Michael to the cc:, sorry.

Quoting Serge E. Hallyn (serge@hallyn.com):
> Quoting Dave Chinner (david@fromorbit.com):
> > On Wed, Jul 31, 2013 at 08:25:23AM -0500, Ben Myers wrote:
> > > Hey,
> > >
> > > On Wed, Jul 31, 2013 at 10:21:19AM +1000, Dave Chinner wrote:
> > > > On Tue, Jul 30, 2013 at 06:40:21PM -0500, Ben Myers wrote:
> > > > > On Mon, Jul 29, 2013 at 11:07:09PM -0400, Dwight Engen wrote:
> > > > > > >From e6a9ee0cfa0ed40484f66bc1726dc19de36038b8 Mon Sep 17 00:00:00 2001
> > > > > > From: Dwight Engen <dwight.engen@oracle.com>
> > > > > > Date: Tue, 2 Jul 2013 09:52:54 -0400
> > > > > > Subject: [PATCH 7/7] enable building user namespace with xfs
> > > > > >
> > > > > > Signed-off-by: Dwight Engen <dwight.engen@oracle.com>
> > > > >
> > > > > Was there a patch running around to limit bulkstat to init_user_ns? Any other
> > > > > items that needed to be addressed before applying this patch?
> > > >
> > > > Bulkstat has a capable(CAP_SYS_ADMIN) check and therefore can only be
> > > > executed in the init name space. Similarly, all the open-by-handle
> > > > interfaces have the same capable() checks so they can only be
> > > > executed int he init name space, too.
> > >
> > > Gah. I was under the impression that you could have a process with
> > > CAP_SYS_ADMIN in a namespace other than init_user_ns.
> >
> > Ben, until about a week and a half ago I was also working under that
> > same understanding as you. So don't feel bad about not knowing
> > about this basic, fundamental rule because it is completely
> > undocumented and it's not obvious to anyone reading the code until
> > someone points it out....
>
> It's actually all documented in new manpages like namespaces(7) and
> user_namespaces(7). Unfortunately those don't seem to have been released yet.
>
> Michael, I don't see any git development/experimental git branch at
> kernel.org/pub/scm/docs/man-pages - do you have those pages up
> somewhere?
>
> thanks,
> -serge
>
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