NFSv4: Fix up locking for nfs4_state_owner
 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 5c0dd26..78a53f5 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -126,6 +126,7 @@
  * semantics by allowing the server to identify replayed requests.
  */
 struct nfs4_state_owner {
+	spinlock_t	     so_lock;
 	struct list_head     so_list;	 /* per-clientid list of state_owners */
 	struct nfs4_client   *so_client;
 	u32                  so_id;      /* 32-bit identifier, unique */