2 files changed, 38 insertions, 4 deletions

diff --git a/net/tipc/node.c b/net/tipc/node.c
index 5b44c3041be4..d959343043fd 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -1,7 +1,7 @@
 /*
  * net/tipc/node.c: TIPC node management routines
  *
- * Copyright (c) 2000-2006, 2012 Ericsson AB
+ * Copyright (c) 2000-2006, 2012-2014, Ericsson AB
  * Copyright (c) 2005-2006, 2010-2014, Wind River Systems
  * All rights reserved.
  *
@@ -155,21 +155,25 @@ void tipc_node_link_up(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
         if (!active[0]) {
                 active[0] = active[1] = l_ptr;
                 node_established_contact(n_ptr);
-                return;
+                goto exit;
         }
         if (l_ptr->priority < active[0]->priority) {
                 pr_info("New link <%s> becomes standby\n", l_ptr->name);
-                return;
+                goto exit;
         }
         tipc_link_dup_queue_xmit(active[0], l_ptr);
         if (l_ptr->priority == active[0]->priority) {
                 active[0] = l_ptr;
-                return;
+                goto exit;
         }
         pr_info("Old link <%s> becomes standby\n", active[0]->name);
         if (active[1] != active[0])
                 pr_info("Old link <%s> becomes standby\n", active[1]->name);
         active[0] = active[1] = l_ptr;
+exit:
+        /* Leave room for changeover header when returning 'mtu' to users: */
+        n_ptr->act_mtus[0] = active[0]->max_pkt - INT_H_SIZE;
+        n_ptr->act_mtus[1] = active[1]->max_pkt - INT_H_SIZE;
 }
 
 /**
@@ -229,6 +233,19 @@ void tipc_node_link_down(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
                 tipc_link_failover_send_queue(l_ptr);
         else
                 node_lost_contact(n_ptr);
+
+        /* Leave room for changeover header when returning 'mtu' to users: */
+        if (active[0]) {
+                n_ptr->act_mtus[0] = active[0]->max_pkt - INT_H_SIZE;
+                n_ptr->act_mtus[1] = active[1]->max_pkt - INT_H_SIZE;
+                return;
+        }
+
+        /* Loopback link went down? No fragmentation needed from now on. */
+        if (n_ptr->addr == tipc_own_addr) {
+                n_ptr->act_mtus[0] = MAX_MSG_SIZE;
+                n_ptr->act_mtus[1] = MAX_MSG_SIZE;
+        }
 }
 
 int tipc_node_active_links(struct tipc_node *n_ptr)
diff --git a/net/tipc/node.h b/net/tipc/node.h
index 9087063793f2..b61716a8218e 100644
--- a/net/tipc/node.h
+++ b/net/tipc/node.h
@@ -41,6 +41,7 @@
 #include "addr.h"
 #include "net.h"
 #include "bearer.h"
+#include "msg.h"
 
 /*
  * Out-of-range value for node signature
@@ -105,6 +106,7 @@ struct tipc_node {
         spinlock_t lock;
         struct hlist_node hash;
         struct tipc_link *active_links[2];
+        u32 act_mtus[2];
         struct tipc_link *links[MAX_BEARERS];
         unsigned int action_flags;
         struct tipc_node_bclink bclink;
@@ -143,4 +145,19 @@ static inline bool tipc_node_blocked(struct tipc_node *node)
                 TIPC_NOTIFY_NODE_DOWN | TIPC_WAIT_OWN_LINKS_DOWN));
 }
 
+static inline uint tipc_node_get_mtu(u32 addr, u32 selector)
+{
+        struct tipc_node *node;
+        u32 mtu;
+
+        node = tipc_node_find(addr);
+
+        if (likely(node))
+                mtu = node->act_mtus[selector & 1];
+        else
+                mtu = MAX_MSG_SIZE;
+
+        return mtu;
+}
+
 #endif