NFSv4.1: new flag for lease time check

Data servers cannot send nfs4_proc_get_lease_time. but still need to setup
state renewal. Add the NFS_CS_CHECK_LEASE_TIME bit to indicate if the lease
time can be checked.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/client.c

@@ -1400,6 +1400,15 @@ static int nfs4_set_client(struct nfs_server *server,
 		goto error;
 	}
 
+	/*
+	 * Query for the lease time on clientid setup or renewal
+	 *
+	 * Note that this will be set on nfs_clients that were created
+	 * only for the DS role and did not set this bit, but now will
+	 * serve a dual role.
+	 */
+	set_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state);
+
 	server->nfs_client = clp;
 	dprintk("<-- nfs4_set_client() = 0 [new %p]\n", clp);
 	return 0;

fs/nfs/nfs4state.c

@@ -153,6 +153,11 @@ static int nfs41_setup_state_renewal(struct nfs_client *clp)
 	int status;
 	struct nfs_fsinfo fsinfo;
 
+	if (!test_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state)) {
+		nfs4_schedule_state_renewal(clp);
+		return 0;
+	}
+
 	status = nfs4_proc_get_lease_time(clp, &fsinfo);
 	if (status == 0) {
 		/* Update lease time and schedule renewal */

include/linux/nfs_fs_sb.h

@@ -31,6 +31,7 @@ struct nfs_client {
 #define NFS_CS_IDMAP		2		/* - idmap started */
 #define NFS_CS_RENEWD		3		/* - renewd started */
 #define NFS_CS_STOP_RENEW	4		/* no more state to renew */
+#define NFS_CS_CHECK_LEASE_TIME	5		/* need to check lease time */
 	struct sockaddr_storage	cl_addr;	/* server identifier */
 	size_t			cl_addrlen;
 	char *			cl_hostname;	/* hostname of server */