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    SubjectRe: per-process namespace?
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    On Tue, 2004-06-29 at 14:10, Mike Waychison wrote:
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    > Ram Pai wrote:
    > > Is there a way for an application to
    > > 1. fork its own namespace and modify it, and
    > > 2. still be able to see changes to the system namespace?
    > >
    > > Al Viro's Per-process namespace implementation provides the first
    > > feature. But is there any work done to do the second part? Is it worth
    > > doing?
    > >
    > > RP
    >
    > In what sense?
    >
    > The current model has no definition for a 'system namespace'.

    by 'system namespace' I mean the very first initial hand-crafted
    namespace.

    >
    > Accessing /proc/<pid>/mounts where <pid> is running in a different
    > namespace appears to work.

    Are you sure? I dont see it to be the case. I just verified it on 2.6.7
    /proc/<pid>/mounts is a file. However /proc/pid/root is a symbolic link
    to the root directory of the process. So the process with a cloned
    namespace wont be able to access it through its namespace.


    > As well, you can always fchdir back into
    > another namespace temporarily. As long as you don't reference any
    > file/directories using absolute paths (including following symlinks),
    > then you can already navigate the entire namespace.

    If this feature is available then great!

    >
    > This falls apart though when there are no longer any processes keeping
    > that namespace alive. When this happens, the vfsmount's are unstitched
    > and you end up 'stuck' on a given mount :(.

    > Another caveat is that the current system disallows you from doing any
    > mount/umount's in another namespace (bogus security?)
    > .
    >
    > - --
    > Mike Waychison
    > Sun Microsystems, Inc.
    > 1 (650) 352-5299 voice
    > 1 (416) 202-8336 voice
    > http://www.sun.com
    >
    > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    > NOTICE: The opinions expressed in this email are held by me,
    > and may not represent the views of Sun Microsystems, Inc.
    > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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