ocfs2: Fix NULL pointer dereferences in o2net

In some situations, ocfs2_set_nn_state might get called with sc = NULL and
valid = 0. If sc = NULL, we can't dereference it to get the o2nm_node
member. Instead, do what o2net_initialize_handshake does and use NULL when
calling o2net_reconnect_delay and o2net_idle_timeout.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

fs/ocfs2/cluster/tcp.c

@@ -451,9 +451,9 @@ static void o2net_set_nn_state(struct o2net_node *nn,
 		/* delay if we're withing a RECONNECT_DELAY of the
 		 * last attempt */
 		delay = (nn->nn_last_connect_attempt +
-			 msecs_to_jiffies(o2net_reconnect_delay(sc->sc_node)))
+			 msecs_to_jiffies(o2net_reconnect_delay(NULL)))
 			- jiffies;
-		if (delay > msecs_to_jiffies(o2net_reconnect_delay(sc->sc_node)))
+		if (delay > msecs_to_jiffies(o2net_reconnect_delay(NULL)))
 			delay = 0;
 		mlog(ML_CONN, "queueing conn attempt in %lu jiffies\n", delay);
 		queue_delayed_work(o2net_wq, &nn->nn_connect_work, delay);
@@ -1552,12 +1552,11 @@ static void o2net_connect_expired(struct work_struct *work)
 
 	spin_lock(&nn->nn_lock);
 	if (!nn->nn_sc_valid) {
-		struct o2nm_node *node = nn->nn_sc->sc_node;
 		mlog(ML_ERROR, "no connection established with node %u after "
 		     "%u.%u seconds, giving up and returning errors.\n",
 		     o2net_num_from_nn(nn),
-		     o2net_idle_timeout(node) / 1000,
-		     o2net_idle_timeout(node) % 1000);
+		     o2net_idle_timeout(NULL) / 1000,
+		     o2net_idle_timeout(NULL) % 1000);
 
 		o2net_set_nn_state(nn, NULL, 0, -ENOTCONN);
 	}