[TIPC]: Fixed link switchover bugs

Incorporates several related fixes:
- switchover now occurs when switching from an active link to a standby link
- failure of a standby link no longer initiates switchover
- links now display correct # of received packtes following reactivation

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Per Liden <per.liden@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/tipc/link.c b/net/tipc/link.c
index d7668b8abb2da868173063b21d6a32e8121f6132..d64658053746f093d4429cdcd076666bf4bf99ce 100644 (file)
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -690,6 +690,7 @@ void tipc_link_reset(struct link *l_ptr)
        struct sk_buff *buf;
        u32 prev_state = l_ptr->state;
        u32 checkpoint = l_ptr->next_in_no;
+       int was_active_link = tipc_link_is_active(l_ptr);
        
        msg_set_session(l_ptr->pmsg, msg_session(l_ptr->pmsg) + 1);
 
@@ -711,7 +712,7 @@ void tipc_link_reset(struct link *l_ptr)
        tipc_printf(TIPC_CONS, "\nReset link <%s>\n", l_ptr->name);
        dbg_link_dump();
 #endif
-       if (tipc_node_has_active_links(l_ptr->owner) &&
+       if (was_active_link && tipc_node_has_active_links(l_ptr->owner) &&
            l_ptr->owner->permit_changeover) {
                l_ptr->reset_checkpoint = checkpoint;
                l_ptr->exp_msg_count = START_CHANGEOVER;
@@ -754,7 +755,7 @@ void tipc_link_reset(struct link *l_ptr)
 
 static void link_activate(struct link *l_ptr)
 {
-       l_ptr->next_in_no = 1;
+       l_ptr->next_in_no = l_ptr->stats.recv_info = 1;
        tipc_node_link_up(l_ptr->owner, l_ptr);
        tipc_bearer_add_dest(l_ptr->b_ptr, l_ptr->addr);
        link_send_event(tipc_cfg_link_event, l_ptr, 1);
@@ -2303,12 +2304,18 @@ void tipc_link_tunnel(struct link *l_ptr,
        u32 length = msg_size(msg);
 
        tunnel = l_ptr->owner->active_links[selector & 1];
-       if (!tipc_link_is_up(tunnel))
+       if (!tipc_link_is_up(tunnel)) {
+               warn("Link changeover error, "
+                    "tunnel link no longer available\n");
                return;
+       }
        msg_set_size(tunnel_hdr, length + INT_H_SIZE);
        buf = buf_acquire(length + INT_H_SIZE);
-       if (!buf)
+       if (!buf) {
+               warn("Link changeover error, "
+                    "unable to send tunnel msg\n");
                return;
+       }
        memcpy(buf->data, (unchar *)tunnel_hdr, INT_H_SIZE);
        memcpy(buf->data + INT_H_SIZE, (unchar *)msg, length);
        dbg("%c->%c:", l_ptr->b_ptr->net_plane, tunnel->b_ptr->net_plane);
@@ -2328,19 +2335,23 @@ void tipc_link_changeover(struct link *l_ptr)
        u32 msgcount = l_ptr->out_queue_size;
        struct sk_buff *crs = l_ptr->first_out;
        struct link *tunnel = l_ptr->owner->active_links[0];
-       int split_bundles = tipc_node_has_redundant_links(l_ptr->owner);
        struct tipc_msg tunnel_hdr;
+       int split_bundles;
 
        if (!tunnel)
                return;
 
-       if (!l_ptr->owner->permit_changeover)
+       if (!l_ptr->owner->permit_changeover) {
+               warn("Link changeover error, "
+                    "peer did not permit changeover\n");
                return;
+       }
 
        msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
                 ORIGINAL_MSG, TIPC_OK, INT_H_SIZE, l_ptr->addr);
        msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
        msg_set_msgcnt(&tunnel_hdr, msgcount);
+       dbg("Link changeover requires %u tunnel messages\n", msgcount);
 
        if (!l_ptr->first_out) {
                struct sk_buff *buf;
@@ -2360,6 +2371,9 @@ void tipc_link_changeover(struct link *l_ptr)
                return;
        }
 
+       split_bundles = (l_ptr->owner->active_links[0] != 
+                        l_ptr->owner->active_links[1]);
+
        while (crs) {
                struct tipc_msg *msg = buf_msg(crs);
 
@@ -2497,11 +2511,13 @@ static int link_recv_changeover_msg(struct link **l_ptr,
                     dest_link->name);
                tipc_link_reset(dest_link);
                dest_link->exp_msg_count = msg_count;
+               dbg("Expecting %u tunnelled messages\n", msg_count);
                if (!msg_count)
                        goto exit;
        } else if (dest_link->exp_msg_count == START_CHANGEOVER) {
                msg_dbg(tunnel_msg, "BLK/FIRST/<REC<");
                dest_link->exp_msg_count = msg_count;
+               dbg("Expecting %u tunnelled messages\n", msg_count);
                if (!msg_count)
                        goto exit;
        }
@@ -2509,6 +2525,8 @@ static int link_recv_changeover_msg(struct link **l_ptr,
        /* Receive original message */
 
        if (dest_link->exp_msg_count == 0) {
+               warn("Link switchover error, "
+                    "got too many tunnelled messages\n");
                msg_dbg(tunnel_msg, "OVERDUE/DROP/<REC<");
                dbg_print_link(dest_link, "LINK:");
                goto exit;

diff --git a/net/tipc/node.c b/net/tipc/node.c
index 5f097547d3e374c2fb92e8b94f9105fb89f77244..ce9678efa98a5822b5e205d879fb158b3f8ddb44 100644 (file)
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -125,6 +125,8 @@ void tipc_node_link_up(struct node *n_ptr, struct link *l_ptr)
 {
        struct link **active = &n_ptr->active_links[0];
 
+       n_ptr->working_links++;
+
        info("Established link <%s> on network plane %c\n",
             l_ptr->name, l_ptr->b_ptr->net_plane);
        
@@ -185,6 +187,8 @@ void tipc_node_link_down(struct node *n_ptr, struct link *l_ptr)
 {
        struct link **active;
 
+       n_ptr->working_links--;
+
        if (!tipc_link_is_active(l_ptr)) {
                info("Lost standby link <%s> on network plane %c\n",
                     l_ptr->name, l_ptr->b_ptr->net_plane);
@@ -214,8 +218,7 @@ int tipc_node_has_active_links(struct node *n_ptr)
 
 int tipc_node_has_redundant_links(struct node *n_ptr)
 {
-       return (tipc_node_has_active_links(n_ptr) &&
-               (n_ptr->active_links[0] != n_ptr->active_links[1]));
+       return (n_ptr->working_links > 1);
 }
 
 static int tipc_node_has_active_routes(struct node *n_ptr)

diff --git a/net/tipc/node.h b/net/tipc/node.h
index 781126e084aea5bab759de5bff27e0285d4d84ab..a07cc79ea63719f2aaec8737aee2b59153789cc9 100644 (file)
--- a/net/tipc/node.h
+++ b/net/tipc/node.h
@@ -51,6 +51,7 @@
  * @nsub: list of "node down" subscriptions monitoring node
  * @active_links: pointers to active links to node
  * @links: pointers to all links to node
+ * @working_links: number of working links to node (both active and standby)
  * @link_cnt: number of links to node
  * @permit_changeover: non-zero if node has redundant links to this system
  * @routers: bitmap (used for multicluster communication)
@@ -76,6 +77,7 @@ struct node {
        struct link *active_links[2];
        struct link *links[MAX_BEARERS];
        int link_cnt;
+       int working_links;
        int permit_changeover;
        u32 routers[512/32];
        int last_router;