Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm...

Pull namespace fixes from Eric Biederman:
 "I believe all of these are simple obviously correct bug fixes. These
  fall into two groups:

   - Fixing the implementation of MNT_LOCKED which prevents lesser
     privileged users from seeing unders mounts created by more
     privileged users.

   - Fixing the extended uid and group mapping in user namespaces.

  As well as ensuring the code looks correct I have spot tested these
  changes as well and in my testing the fixes are working"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  mount: Prevent MNT_DETACH from disconnecting locked mounts
  mount: Don't allow copying MNT_UNBINDABLE|MNT_LOCKED mounts
  mount: Retest MNT_LOCKED in do_umount
  userns: also map extents in the reverse map to kernel IDs