Re: [RFC] shared subtrees

[Al Viro <viro@parcelfarce.linux.theplanet.co.uk>]

On Sun, Jan 16, 2005 at 01:42:09PM -0500, J. Bruce Fields wrote:
> On Sun, Jan 16, 2005 at 06:06:56PM +0000, Al Viro wrote:
> > On Sun, Jan 16, 2005 at 11:02:13AM -0500, J. Bruce Fields wrote:
> > > On Thu, Jan 13, 2005 at 10:18:51PM +0000, Al Viro wrote:
> > > > 	6. mount --move
> > > > prohibited if what we are moving is in some p-node, otherwise we move
> > > > as usual to intended mountpoint and create copies for everything that
> > > > gets propagation from there (as we would do for rbind).
> > > 
> > > Why this prohibition?
> > 
> > How do you propagate that?  We can weaken that to "in a p-node that
> > owns something or contains more than one vfsmount", but it's not
> > worth the trouble, AFAICS.
> 
> I guess I'm not seeing what there is to propagate.  If the vfsmount we
> are moving is mounted under a vfsmount that's in a p-node, then there'd
> be something to propagate, but since the --move doesn't change the
> structure of mounts underneath the moved mountpoint, I wouldn't expect
> any changes to be propagated from it to other mountpoints.
> 
> I must be missing something fundamental....

No - I have been missing a typo.  Make that "if mountpoint of what we
are moving...".