tipc: ensure that idle links are deleted when a bearer is disabled

commit afaa3f65f65fda2e7b190aac7e2a75d9a2a77cb6
(tipc: purge links when bearer is disabled) was an attempt to resolve
a problem that turned out to have a more profound reason.

When we disable a bearer, we delete all its pertaining links if
there is no other bearer to perform failover to, or if the module
is shutting down. In case there are dual bearers, we wait with
deleting links until the failover procedure is finished.

However, this misses the case when a link on the removed bearer
was already down, so that there will be no failover procedure to
finish the link delete. This causes confusion if a new bearer is
added to replace the removed one, and also entails a small memory
leak.

This commit takes the current state of the link into account when
deciding when to delete it, and also reverses the above-mentioned
commit.

Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index 840db89e428308bbf2e51a51711319baa4a85a65..3613e72e858e2e259bd91455127e4ec0af5c903b 100644 (file)
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -747,7 +747,7 @@ int tipc_nl_bearer_disable(struct sk_buff *skb, struct genl_info *info)
                return -EINVAL;
        }
 
-       bearer_disable(net, bearer, true);
+       bearer_disable(net, bearer, false);
        rtnl_unlock();
 
        return 0;

diff --git a/net/tipc/link.c b/net/tipc/link.c
index 14f09b3cb87c2fd9c87c67dfb67ce5e8df7d9f0f..98609fdfb06ae6031f9630eb87c3bf0399ecb1a3 100644 (file)
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -344,6 +344,7 @@ void tipc_link_delete_list(struct net *net, unsigned int bearer_id,
        struct tipc_net *tn = net_generic(net, tipc_net_id);
        struct tipc_link *link;
        struct tipc_node *node;
+       bool del_link;
 
        rcu_read_lock();
        list_for_each_entry_rcu(node, &tn->node_list, list) {
@@ -353,12 +354,13 @@ void tipc_link_delete_list(struct net *net, unsigned int bearer_id,
                        tipc_node_unlock(node);
                        continue;
                }
+               del_link = !tipc_link_is_up(link) && !link->exp_msg_count;
                tipc_link_reset(link);
                if (del_timer(&link->timer))
                        tipc_link_put(link);
                link->flags |= LINK_STOPPED;
                /* Delete link now, or when failover is finished: */
-               if (shutting_down || !tipc_node_is_up(node))
+               if (shutting_down || !tipc_node_is_up(node) || del_link)
                        tipc_link_delete(link);
                tipc_node_unlock(node);
        }