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Date:   Mon, 31 Aug 2020 14:23:39 +0100
From:   Matthew Wilcox <willy@infradead.org>
To:     Miklos Szeredi <miklos@szeredi.hu>
Cc:     Al Viro <viro@zeniv.linux.org.uk>,
        Dave Chinner <david@fromorbit.com>,
        "Dr. David Alan Gilbert" <dgilbert@redhat.com>,
        Greg Kurz <groug@kaod.org>, linux-fsdevel@vger.kernel.org,
        Stefan Hajnoczi <stefanha@redhat.com>,
        Miklos Szeredi <mszeredi@redhat.com>,
        Vivek Goyal <vgoyal@redhat.com>,
        Giuseppe Scrivano <gscrivan@redhat.com>,
        Daniel J Walsh <dwalsh@redhat.com>,
        Chirantan Ekbote <chirantan@chromium.org>
Subject: Re: xattr names for unprivileged stacking?
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On Mon, Aug 31, 2020 at 01:51:20PM +0200, Miklos Szeredi wrote:
> On Mon, Aug 31, 2020 at 1:37 PM Matthew Wilcox <willy@infradead.org> wrote:
> 
> > As I said to Dave, you and I have a strong difference of opinion here.
> > I think that what you are proposing is madness.  You're making it too
> > flexible which comes with too much opportunity for abuse.
> 
> Such as?

One proposal I saw earlier in this thread was to do something like
$ runalt /path/to/file ls
which would open_alt() /path/to/file, fchdir to it and run ls inside it.
That's just crazy.

> >  I just want
> > to see alternate data streams for the same filename in order to support
> > existing use cases.  You seem to be able to want to create an entire
> > new world inside a file, and that's just too confusing.
> 
> To whom?  I'm sure users of ancient systems with a flat directory
> found directory trees very confusing.  Yet it turned out that the
> hierarchical system beat the heck out of the flat one.

Which doesn't mean that multiple semi-hidden hierarchies are going to
be better than one visible hierarchy.