nfs41: recover lease in _nfs4_lookup_root

This creates the nfsv4.1 session on mount.
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/client.c

@@ -527,6 +527,22 @@ void nfs_mark_client_ready(struct nfs_client *clp, int state)
 	wake_up_all(&nfs_client_active_wq);
 }
 
+/*
+ * With sessions, the client is not marked ready until after a
+ * successful EXCHANGE_ID and CREATE_SESSION.
+ *
+ * Map errors cl_cons_state errors to EPROTONOSUPPORT to indicate
+ * other versions of NFS can be tried.
+ */
+int nfs4_check_client_ready(struct nfs_client *clp)
+{
+	if (!nfs4_has_session(clp))
+		return 0;
+	if (clp->cl_cons_state < NFS_CS_READY)
+		return -EPROTONOSUPPORT;
+	return 0;
+}
+
 /*
  * Initialise the timeout values for a connection
  */

fs/nfs/internal.h

@@ -114,6 +114,7 @@ extern struct nfs_server *nfs_clone_server(struct nfs_server *,
 					   struct nfs_fh *,
 					   struct nfs_fattr *);
 extern void nfs_mark_client_ready(struct nfs_client *clp, int state);
+extern int nfs4_check_client_ready(struct nfs_client *clp);
 #ifdef CONFIG_PROC_FS
 extern int __init nfs_fs_proc_init(void);
 extern void nfs_fs_proc_exit(void);

fs/nfs/nfs4proc.c

@@ -2024,8 +2024,15 @@ static int _nfs4_lookup_root(struct nfs_server *server, struct nfs_fh *fhandle,
 		.rpc_argp = &args,
 		.rpc_resp = &res,
 	};
+	int status;
+
 	nfs_fattr_init(info->fattr);
-	return nfs4_call_sync(server, &msg, &args, &res, 0);
+	status = nfs4_recover_expired_lease(server);
+	if (!status)
+		status = nfs4_check_client_ready(server->nfs_client);
+	if (!status)
+		status = nfs4_call_sync(server, &msg, &args, &res, 0);
+	return status;
 }
 
 static int nfs4_lookup_root(struct nfs_server *server, struct nfs_fh *fhandle,