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>

1 files changed, 16 insertions, 12 deletions

diff --git a/net/tipc/node.c b/net/tipc/node.c
index ec8360736239..4f517ff783d9 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -72,14 +72,14 @@ struct tipc_node *tipc_node_find(u32 addr)
         if (unlikely(!in_own_cluster_exact(addr)))
                 return NULL;
 
-        spin_lock_bh(&node_list_lock);
-        hlist_for_each_entry(node, &node_htable[tipc_hashfn(addr)], hash) {
+        rcu_read_lock();
+        hlist_for_each_entry_rcu(node, &node_htable[tipc_hashfn(addr)], hash) {
                 if (node->addr == addr) {
-                        spin_unlock_bh(&node_list_lock);
+                        rcu_read_unlock();
                         return node;
                 }
         }
-        spin_unlock_bh(&node_list_lock);
+        rcu_read_unlock();
         return NULL;
 }
 
@@ -102,13 +102,13 @@ struct tipc_node *tipc_node_create(u32 addr)
         INIT_LIST_HEAD(&n_ptr->list);
         INIT_LIST_HEAD(&n_ptr->nsub);
 
-        hlist_add_head(&n_ptr->hash, &node_htable[tipc_hashfn(addr)]);
+        hlist_add_head_rcu(&n_ptr->hash, &node_htable[tipc_hashfn(addr)]);
 
-        list_for_each_entry(temp_node, &tipc_node_list, list) {
+        list_for_each_entry_rcu(temp_node, &tipc_node_list, list) {
                 if (n_ptr->addr < temp_node->addr)
                         break;
         }
-        list_add_tail(&n_ptr->list, &temp_node->list);
+        list_add_tail_rcu(&n_ptr->list, &temp_node->list);
         n_ptr->block_setup = WAIT_PEER_DOWN;
         n_ptr->signature = INVALID_NODE_SIG;
 
@@ -120,9 +120,9 @@ struct tipc_node *tipc_node_create(u32 addr)
 
 static void tipc_node_delete(struct tipc_node *n_ptr)
 {
-        list_del(&n_ptr->list);
-        hlist_del(&n_ptr->hash);
-        kfree(n_ptr);
+        list_del_rcu(&n_ptr->list);
+        hlist_del_rcu(&n_ptr->hash);
+        kfree_rcu(n_ptr, rcu);
 
         tipc_num_nodes--;
 }
@@ -359,7 +359,8 @@ struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space)
         }
 
         /* Add TLVs for all nodes in scope */
-        list_for_each_entry(n_ptr, &tipc_node_list, list) {
+        rcu_read_lock();
+        list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
                 if (!tipc_in_scope(domain, n_ptr->addr))
                         continue;
                 node_info.addr = htonl(n_ptr->addr);
@@ -367,6 +368,7 @@ struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space)
                 tipc_cfg_append_tlv(buf, TIPC_TLV_NODE_INFO,
                                     &node_info, sizeof(node_info));
         }
+        rcu_read_unlock();
         spin_unlock_bh(&node_list_lock);
         return buf;
 }
@@ -412,7 +414,8 @@ struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space)
         tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, &link_info, sizeof(link_info));
 
         /* Add TLVs for any other links in scope */
-        list_for_each_entry(n_ptr, &tipc_node_list, list) {
+        rcu_read_lock();
+        list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
                 u32 i;
 
                 if (!tipc_in_scope(domain, n_ptr->addr))
@@ -429,6 +432,7 @@ struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space)
                 }
                 tipc_node_unlock(n_ptr);
         }
+        rcu_read_unlock();
         spin_unlock_bh(&node_list_lock);
         return buf;
 }