tipc: confgiure and apply UDP bearer MTU on running links

Currently, we have option to configure MTU of UDP media. The configured
MTU takes effect on the links going up after that moment. I.e, a user
has to reset bearer to have new value applied across its links. This is
confusing and disturbing on a running cluster.

We now introduce the functionality to change the default UDP bearer MTU
in struct tipc_bearer. Additionally, the links are updated dynamically,
without any need for a reset, when bearer value is changed. We leverage
the existing per-link functionality and the design being symetrical to
the confguration of link tolerance.

Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: GhantaKrishnamurthy MohanKrishna <mohan.krishna.ghanta.krishnamurthy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 3 deletions

diff --git a/net/tipc/node.c b/net/tipc/node.c
index c77dd2f3c589..b71e4e376bb9 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -1681,7 +1681,8 @@ discard:
         kfree_skb(skb);
 }
 
-void tipc_node_apply_tolerance(struct net *net, struct tipc_bearer *b)
+void tipc_node_apply_property(struct net *net, struct tipc_bearer *b,
+                              int prop)
 {
         struct tipc_net *tn = tipc_net(net);
         int bearer_id = b->identity;
@@ -1696,8 +1697,13 @@ void tipc_node_apply_tolerance(struct net *net, struct tipc_bearer *b)
         list_for_each_entry_rcu(n, &tn->node_list, list) {
                 tipc_node_write_lock(n);
                 e = &n->links[bearer_id];
-                if (e->link)
-                        tipc_link_set_tolerance(e->link, b->tolerance, &xmitq);
+                if (e->link) {
+                        if (prop == TIPC_NLA_PROP_TOL)
+                                tipc_link_set_tolerance(e->link, b->tolerance,
+                                                        &xmitq);
+                        else if (prop == TIPC_NLA_PROP_MTU)
+                                tipc_link_set_mtu(e->link, b->mtu);
+                }
                 tipc_node_write_unlock(n);
                 tipc_bearer_xmit(net, bearer_id, &xmitq, &e->maddr);
         }