tipc: avoid to asynchronously notify subscriptions

Postpone the actions of notifying subscriptions until after node lock
is released, avoiding to asynchronously execute registered handlers
when node is lost.

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, 21 insertions, 2 deletions

diff --git a/net/tipc/node.c b/net/tipc/node.c
index 2b0a0849d4cc..befbcc9eade6 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -321,10 +321,10 @@ static void node_lost_contact(struct tipc_node *n_ptr)
         }
 
         /* Notify subscribers */
-        tipc_nodesub_notify(n_ptr);
+        n_ptr->flags = TIPC_NODE_LOST;
 
         /* Prevent re-contact with node until cleanup is done */
-        n_ptr->flags = TIPC_NODE_DOWN | TIPC_NAMES_GONE;
+        n_ptr->flags |= TIPC_NODE_DOWN | TIPC_NAMES_GONE;
         tipc_k_signal((Handler)node_name_purge_complete, n_ptr->addr);
 }
 
@@ -465,3 +465,22 @@ int tipc_node_get_linkname(u32 bearer_id, u32 addr, char *linkname, size_t len)
         tipc_node_unlock(node);
         return -EINVAL;
 }
+
+void tipc_node_unlock(struct tipc_node *node)
+{
+        LIST_HEAD(nsub_list);
+
+        if (likely(!node->flags)) {
+                spin_unlock_bh(&node->lock);
+                return;
+        }
+
+        if (node->flags & TIPC_NODE_LOST) {
+                list_replace_init(&node->nsub, &nsub_list);
+                node->flags &= ~TIPC_NODE_LOST;
+        }
+        spin_unlock_bh(&node->lock);
+
+        if (!list_empty(&nsub_list))
+                tipc_nodesub_notify(&nsub_list);
+}