Merge tag 'gfs2-4.11.addendum' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2

Pull GFS2 fix from Bob Peterson:
 "This is an addendum for the 4.11 merge window.

  Andy Price wrote this patch to close a nasty race condition that
  allows access to glocks that are being destroyed. Without this patch,
  GFS2 is vulnerable to random corruption and kernel panic"

* tag 'gfs2-4.11.addendum' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
  gfs2: Add missing rcu locking for glock	lookup