NFSD: added FREE_STATEID operation

This operation is used by the client to tell the server to free a
stateid.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 7406f1c..a27dea5 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1417,6 +1417,11 @@
 		.op_flags = OP_HANDLES_WRONGSEC,
 		.op_name = "OP_SECINFO_NO_NAME",
 	},
+	[OP_FREE_STATEID] = {
+		.op_func = (nfsd4op_func)nfsd4_free_stateid,
+		.op_flags = ALLOWED_WITHOUT_FH,
+		.op_name = "OP_FREE_STATEID",
+	},
 };
 
 static const char *nfsd4_op_name(unsigned opnum)