It is not sufficient to just check that the lock pids match when
granting a callback, we also need to ensure that we're granting
the callback on the right file.
Reported-by: NPankaj Singh <psingh.ait@gmail.com>
Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>