4 files changed, 37 insertions, 13 deletions

diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index 4609819ea80..15eb7445874 100644
--- a/net/tipc/bcast.c
+++ b/net/tipc/bcast.c
@@ -237,14 +237,36 @@ void tipc_bclink_acknowledge(struct tipc_node *n_ptr, u32 acked)
         struct sk_buff *next;
         unsigned int released = 0;
 
-        if (less_eq(acked, n_ptr->bclink.acked))
-                return;
-
         spin_lock_bh(&bc_lock);
 
-        /* Skip over packets that node has previously acknowledged */
-
+        /* Bail out if tx queue is empty (no clean up is required) */
         crs = bcl->first_out;
+        if (!crs)
+                goto exit;
+
+        /* Determine which messages need to be acknowledged */
+        if (acked == INVALID_LINK_SEQ) {
+                /*
+                 * Contact with specified node has been lost, so need to
+                 * acknowledge sent messages only (if other nodes still exist)
+                 * or both sent and unsent messages (otherwise)
+                 */
+                if (bclink->bcast_nodes.count)
+                        acked = bcl->fsm_msg_cnt;
+                else
+                        acked = bcl->next_out_no;
+        } else {
+                /*
+                 * Bail out if specified sequence number does not correspond
+                 * to a message that has been sent and not yet acknowledged
+                 */
+                if (less(acked, buf_seqno(crs)) ||
+                    less(bcl->fsm_msg_cnt, acked) ||
+                    less_eq(acked, n_ptr->bclink.acked))
+                        goto exit;
+        }
+
+        /* Skip over packets that node has previously acknowledged */
         while (crs && less_eq(buf_seqno(crs), n_ptr->bclink.acked))
                 crs = crs->next;
 
@@ -255,8 +277,6 @@ void tipc_bclink_acknowledge(struct tipc_node *n_ptr, u32 acked)
 
                 if (crs != bcl->next_out)
                         bcbuf_decr_acks(crs);
-                else if (bclink->bcast_nodes.count)
-                        break;
                 else {
                         bcbuf_set_acks(crs, 0);
                         bcl->next_out = next;
@@ -281,6 +301,7 @@ void tipc_bclink_acknowledge(struct tipc_node *n_ptr, u32 acked)
         }
         if (unlikely(released && !list_empty(&bcl->waiting_ports)))
                 tipc_link_wakeup_ports(bcl, 0);
+exit:
         spin_unlock_bh(&bc_lock);
 }
 
diff --git a/net/tipc/link.c b/net/tipc/link.c
index 332915e4304..4eff342326e 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -1733,10 +1733,8 @@ void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *b_ptr)
 
                 /* Release acked messages */
 
-                if (less(n_ptr->bclink.acked, msg_bcast_ack(msg))) {
-                        if (tipc_node_is_up(n_ptr) && n_ptr->bclink.supported)
-                                tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
-                }
+                if (tipc_node_is_up(n_ptr) && n_ptr->bclink.supported)
+                        tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
 
                 crs = l_ptr->first_out;
                 while ((crs != l_ptr->next_out) &&
diff --git a/net/tipc/link.h b/net/tipc/link.h
index e56cb532913..78792399d66 100644
--- a/net/tipc/link.h
+++ b/net/tipc/link.h
@@ -45,6 +45,12 @@
 #define PUSH_FINISHED 2
 
 /*
+ * Out-of-range value for link sequence numbers
+ */
+
+#define INVALID_LINK_SEQ 0x10000
+
+/*
  * Link states
  */
 
diff --git a/net/tipc/node.c b/net/tipc/node.c
index 1861ae915f1..e530de279be 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -351,8 +351,7 @@ static void node_lost_contact(struct tipc_node *n_ptr)
                 }
 
                 tipc_bclink_remove_node(n_ptr->addr);
-                tipc_bclink_acknowledge(n_ptr,
-                                        mod(n_ptr->bclink.acked + 10000));
+                tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ);
                 if (n_ptr->addr < tipc_own_addr)
                         tipc_own_tag--;