[REVIEW][PATCH] vfs: Lock in place mounts from more privileged users

[Serge E. Hallyn]

Quoting Serge E. Hallyn (serge at hallyn.com):
> Quoting Eric W. Biederman (ebiederm at xmission.com):
> > 
> > Serge does this patch break lxc?  I think all should be well but I want
> > to make certain there is not some hidden case where this fundamentaly
> > breaks some functionality.
> 
> I haven't yet tried.  I'll build and test a kernel today.  I'm pretty
> sure all the child's mounts are done after clone, so I *think* the worst
> case will be that the unmounting of put_old after pivot_root() will
> be noisy.  Will let you know.
> 
> -serge

Just tested it - works fine.  Warns about all of the failed umounts.

Acked-by: Serge Hallyn <serge.hallyn at canonical.com>

( Mind you I'm not approving of the idea of hiding mounts as a security
mechanisms, but I know that neither are you :)

thanks,
-serge