Re: [RFC] shared subtrees

[Mike Waychison]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Al Viro wrote:
> 	3. bind
> 
> bind works almost identically to mount; new vfsmount is created for every
> place that gets propagation from mountpoint and propagation is set up to
> mirror that between the mountpoints.  However, there is a difference: unlike
> the case of mount, vfsmount we were going to attach (say it, A) has some
> history - it was created as a  copy of some pre-existing vfsmount V.  And
> that's where the things get interesting:
> 	* if V is contained in some p-node p, A is placed into the same
> p-node.  That may require merging one of the p-nodes we'd just created
> with p (that will be the counterpart of the p-node containing the mountpoint).
> 	* if V is owned by some p-node p, then A (or p-node containing A)
> becomes owned by p.
> 

Corner case: how do we handle the case where:

mount --make-shared /foo
mount --bind /foo /foo/bar

A nested --bind without sharing makes sense, but doesn't when sharing is
enabled (infinite loop).

How about a rule that states that for all Ai,Aj in p-node p, Ai must not
parent Aj in the vfsmount tree.  This can be enforced at graft time.

- --
Mike Waychison
Sun Microsystems, Inc.
1 (650) 352-5299 voice
1 (416) 202-8336 voice

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NOTICE:  The opinions expressed in this email are held by me,
and may not represent the views of Sun Microsystems, Inc.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.5 (GNU/Linux)
Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org

iD8DBQFB7ARmdQs4kOxk3/MRAjkjAKCEBWx7iOWhTu1EOR2ABMr5abW4RgCdGlMu
u/Isw16fgZaErR3BErWq3JI=
=mJnu
-----END PGP SIGNATURE-----
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/