tipc: reverse call order for link_reset()->node_link_down()

In many cases the call order when a link is reset goes as follows:
tipc_node_xx()->tipc_link_reset()->tipc_node_link_down()

This is not the right order if we want the node to be in control,
so in this commit we change the order to:
tipc_node_xx()->tipc_node_link_down()->tipc_link_reset()

The fact that tipc_link_reset() now is called from only one
location with a well-defined state will also facilitate later
simplifications of tipc_link_reset() and the link FSM.

Tested-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 22 insertions, 14 deletions

diff --git a/net/tipc/link.c b/net/tipc/link.c
index 8c81db7b17f9..2ccdb6ffd5c8 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -566,7 +566,6 @@ void tipc_link_purge_queues(struct tipc_link *l_ptr)
 void tipc_link_reset(struct tipc_link *l_ptr)
 {
         u32 prev_state = l_ptr->state;
-        int was_active_link = tipc_link_is_active(l_ptr);
         struct tipc_node *owner = l_ptr->owner;
         struct tipc_link *pl = tipc_parallel_link(l_ptr);
 
@@ -584,10 +583,7 @@ void tipc_link_reset(struct tipc_link *l_ptr)
             (prev_state == TIPC_LINK_ESTABLISHING))
                 return;
 
-        tipc_node_link_down(l_ptr->owner, l_ptr->bearer_id);
-        tipc_bearer_remove_dest(owner->net, l_ptr->bearer_id, l_ptr->addr);
-
-        if (was_active_link && tipc_node_is_up(l_ptr->owner) && (pl != l_ptr)) {
+        if (tipc_node_is_up(l_ptr->owner) && (pl != l_ptr)) {
                 l_ptr->exec_mode = TIPC_LINK_BLOCKED;
                 l_ptr->failover_checkpt = l_ptr->rcv_nxt;
                 pl->failover_pkts = FIRST_FAILOVER;
diff --git a/net/tipc/node.c b/net/tipc/node.c
index 6a0680ba98a9..65c2c80cffe7 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -265,7 +265,7 @@ static void tipc_node_timeout(unsigned long data)
                         tipc_node_calculate_timer(n, l);
                         rc = tipc_link_timeout(l, &xmitq);
                         if (rc & TIPC_LINK_DOWN_EVT)
-                                tipc_link_reset(l);
+                                tipc_node_link_down(n, bearer_id);
                 }
                 tipc_node_unlock(n);
                 maddr = &n->links[bearer_id].maddr;
@@ -338,10 +338,15 @@ void tipc_node_link_down(struct tipc_node *n, int bearer_id)
         struct tipc_link *l, *_l;
 
         l = n->links[bearer_id].link;
+        if (!l || !tipc_link_is_up(l))
+                return;
+
         n->working_links--;
         n->action_flags |= TIPC_NOTIFY_LINK_DOWN;
         n->link_id = l->peer_bearer_id << 16 | l->bearer_id;
 
+        tipc_bearer_remove_dest(n->net, l->bearer_id, n->addr);
+
         pr_debug("Lost link <%s> on network plane %c\n",
                  l->name, l->net_plane);
 
@@ -352,6 +357,8 @@ void tipc_node_link_down(struct tipc_node *n, int bearer_id)
                 _l = n->links[i].link;
                 if (!_l || !tipc_link_is_up(_l))
                         continue;
+                if (_l == l)
+                        continue;
                 if (_l->priority < highest)
                         continue;
                 if (_l->priority > highest) {
@@ -362,9 +369,13 @@ void tipc_node_link_down(struct tipc_node *n, int bearer_id)
                 }
                 *slot1 = i;
         }
+
         if (tipc_node_is_up(n))
                 tipc_link_failover_send_queue(l);
-        else
+
+        tipc_link_reset(l);
+
+        if (!tipc_node_is_up(n))
                 node_lost_contact(n);
 }
 
@@ -403,7 +414,7 @@ bool tipc_node_update_dest(struct tipc_node *n,  struct tipc_bearer *b,
         }
         memcpy(&l->media_addr, maddr, sizeof(*maddr));
         memcpy(curr, maddr, sizeof(*maddr));
-        tipc_link_reset(l);
+        tipc_node_link_down(n, b->identity);
         return true;
 }
 
@@ -418,7 +429,7 @@ void tipc_node_delete_links(struct net *net, int bearer_id)
                 tipc_node_lock(n);
                 l = n->links[bearer_id].link;
                 if (l) {
-                        tipc_link_reset(l);
+                        tipc_node_link_down(n, bearer_id);
                         n->links[bearer_id].link = NULL;
                         n->link_cnt--;
                 }
@@ -439,8 +450,9 @@ static void tipc_node_reset_links(struct tipc_node *n)
                 tipc_addr_string_fill(addr_string, n->addr));
 
         for (i = 0; i < MAX_BEARERS; i++) {
-                if (n->links[i].link)
-                        tipc_link_reset(n->links[i].link);
+                if (!n->links[i].link)
+                        continue;
+                tipc_node_link_down(n, i);
         }
         tipc_node_unlock(n);
 }
@@ -837,7 +849,7 @@ int tipc_node_xmit(struct net *net, struct sk_buff_head *list,
                 if (likely(l))
                         rc = tipc_link_xmit(l, list, &xmitq);
                 if (unlikely(rc == -ENOBUFS))
-                        tipc_link_reset(l);
+                        tipc_node_link_down(n, bearer_id);
                 tipc_node_unlock(n);
                 tipc_node_put(n);
         }
@@ -902,7 +914,7 @@ static void tipc_node_tnl_init(struct tipc_node *n, int bearer_id,
 
         if (msg_type(hdr) == FAILOVER_MSG) {
                 if (tipc_link_is_up(pl)) {
-                        tipc_link_reset(pl);
+                        tipc_node_link_down(n, pb_id);
                         pl->exec_mode = TIPC_LINK_BLOCKED;
                 }
         }
@@ -978,7 +990,7 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
         if (unlikely(rc & TIPC_LINK_UP_EVT))
                 tipc_node_link_up(n, bearer_id);
         if (unlikely(rc & TIPC_LINK_DOWN_EVT))
-                tipc_link_reset(l);
+                tipc_node_link_down(n, bearer_id);
         skb = NULL;
 unlock:
         tipc_node_unlock(n);