Re: linux-next: manual merge of the selinux tree with the vfs tree

[Al Viro <viro@zeniv.linux.org.uk>]

On Thu, Nov 29, 2018 at 05:23:24PM -0500, Paul Moore wrote:

> > OK, I will verify that the SELinux submount fix rebased on top of
> > vfs/work.mount in the way I suggested above passes the same testing
> > (seliinux-testsuite + NFS crossmnt reproducer). I am now building two
> > kernels (vfs/work.mount with and without the fix) to test. Let me know
> > if there is anything more to do.
> 
> Thanks.
> 
> The big thing is just making sure that we don't regress on the fix in
> selinux/next if/when David's mount rework hits Linus' tree.

FWIW, the whole thing is getting massaged/reordered/etc. and I would
like some input from you guys at some point - assuming that I recover
the ability to talk about LSM without obscenities...

Question: what *should* happen if we try to cross into a submount and find
that the thing on the other side is already mounted elsewhere, with incompatible
LSM options?  Ditto for referrals, with an extra twist - what if we are given
3 alternatives, the first two already mounted elsewhere with incompatible
options, the third one not mounted anywhere yet?

Incidentally, should smack have ->sb_clone_mnt_opts()?