tipc: tipc: convert node list and node hlist to RCU lists

Convert tipc_node_list list and node_htable hash list to RCU lists.
On read side, the two lists are protected with RCU read lock, and
on update side, node_list_lock is applied to them.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/tipc/link.c b/net/tipc/link.c
index 882c5c9..c5190ab 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -280,13 +280,13 @@
 	return l_ptr;
 }
 
-
 void tipc_link_delete_list(unsigned int bearer_id, bool shutting_down)
 {
 	struct tipc_link *l_ptr;
 	struct tipc_node *n_ptr;
 
-	list_for_each_entry(n_ptr, &tipc_node_list, list) {
+	rcu_read_lock();
+	list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
 		spin_lock_bh(&n_ptr->lock);
 		l_ptr = n_ptr->links[bearer_id];
 		if (l_ptr) {
@@ -309,6 +309,7 @@
 		}
 		spin_unlock_bh(&n_ptr->lock);
 	}
+	rcu_read_unlock();
 }
 
 /**
@@ -461,13 +462,15 @@
 	struct tipc_link *l_ptr;
 	struct tipc_node *n_ptr;
 
-	list_for_each_entry(n_ptr, &tipc_node_list, list) {
+	rcu_read_lock();
+	list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
 		spin_lock_bh(&n_ptr->lock);
 		l_ptr = n_ptr->links[bearer_id];
 		if (l_ptr)
 			tipc_link_reset(l_ptr);
 		spin_unlock_bh(&n_ptr->lock);
 	}
+	rcu_read_unlock();
 }
 
 static void link_activate(struct tipc_link *l_ptr)
@@ -2404,13 +2407,12 @@
 {
 	struct tipc_link *l_ptr;
 	struct tipc_node *n_ptr;
-	struct tipc_node *tmp_n_ptr;
 	struct tipc_node *found_node = 0;
-
 	int i;
 
 	*bearer_id = 0;
-	list_for_each_entry_safe(n_ptr, tmp_n_ptr, &tipc_node_list, list) {
+	rcu_read_lock();
+	list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
 		tipc_node_lock(n_ptr);
 		for (i = 0; i < MAX_BEARERS; i++) {
 			l_ptr = n_ptr->links[i];
@@ -2424,6 +2426,8 @@
 		if (found_node)
 			break;
 	}
+	rcu_read_unlock();
+
 	return found_node;
 }