VFS,CIFS,NLM,NFSv4: make filesystems directly responsible for calling
   posix_lock_file() if they need it. This fixes an NFS race whereby
   in case of a server reboot, the recovery thread could re-establish
   a lock that had just been freed.
Signed-off-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>