Date: Thu, 20 Oct 2011 05:19:46 -0400
From: Christoph Hellwig <hch@infradead.org>
To: "J. Bruce Fields" <bfields@fieldses.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>, agruen@kernel.org,
        akpm@linux-foundation.org, viro@zeniv.linux.org.uk,
        dhowells@redhat.com, linux-fsdevel@vger.kernel.org,
        linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH -V7 21/26] richacl: xattr mapping functions
Message-ID: <20111020091946.GA23773@infradead.org>
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On Thu, Oct 20, 2011 at 05:14:34AM -0400, J. Bruce Fields wrote:
> > > Does it really make sense to use a string here just to pick between the
> > > three choices OWNER@, GROUP@, and EVERYONE@?  Why not just another small
> > > integer?  Is the goal to expand this somehow eventually?
> > 

> > I guess Andreas wanted the disk layout to be able to store user@domain
> > format if needed.
> 
> Is that likely?  For that to be useful, tasks would need to be able to
> run as user@domain strings.  And we'd probably want owners and groups to
> also be user@domain strings.
> 
> The container people seem to eventually want to add some kind of
> namespace identifier everywhere:
> 
> 	http://marc.info/?l=linux-kernel&m=131836778427871&w=2
> 
> in which case I guess we'd likely end up with (uid, user namespace id)
> instead of user@domain?


Storing strings is an extremly stupid idea.  The only thing that would
make sense would be storing a windows-style 128-bit GUID.