[ 71/73] NFSv4.x: Fix handling of partially delegated locks

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

3.8-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Trond Myklebust <Trond.Myklebust@netapp.com>

commit c5a2a15f8146fdfe45078df7873a6dc1006b3869 upstream.

If a NFS client receives a delegation for a file after it has taken
a lock on that file, we can currently end up in a situation where
we mistakenly skip unlocking that file.

The following patch swaps an erroneous check in nfs4_proc_unlck for
whether or not the file has a delegation to one which checks whether
or not we hold a lock stateid for that file.

Reported-by: Chuck Lever <Chuck.Lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Tested-by: Chuck Lever <Chuck.Lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/nfs/nfs4proc.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -4513,9 +4513,9 @@ static int nfs4_proc_unlck(struct nfs4_s
 	if (status != 0)
 		goto out;
 	/* Is this a delegated lock? */
-	if (test_bit(NFS_DELEGATED_STATE, &state->flags))
-		goto out;
 	lsp = request->fl_u.nfs4_fl.owner;
+	if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) == 0)
+		goto out;
 	seqid = nfs_alloc_seqid(&lsp->ls_seqid, GFP_KERNEL);
 	status = -ENOMEM;
 	if (seqid == NULL)