tipc: Give Tx of discovery responses priority over link messages

Delay releasing the node lock when processing a neighbor discovery
message until after the optional discovery response message has been
sent. This helps ensure that any link protocol messages sent by a
link endpoint created as a result of a neighbor discovery request
are received after the discovery response is received, thereby
giving the receiving node a chance to create a peer link endpoint to
consume those link protocol messages, if one does not already exist.

Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

1 files changed, 9 insertions, 7 deletions

diff --git a/net/tipc/discover.c b/net/tipc/discover.c
index 2345268ca64b..580b50a79e43 100644
--- a/net/tipc/discover.c
+++ b/net/tipc/discover.c
@@ -201,14 +201,16 @@ void tipc_disc_recv_msg(struct sk_buff *buf, struct tipc_bearer *b_ptr)
 
         /* Accept discovery message & send response, if necessary */
         link_fully_up = link_working_working(link);
-        tipc_node_unlock(n_ptr);
-        if ((type == DSC_RESP_MSG) || link_fully_up)
-                return;
-        rbuf = tipc_disc_init_msg(DSC_RESP_MSG, orig, b_ptr);
-        if (rbuf != NULL) {
-                b_ptr->media->send_msg(rbuf, b_ptr, &media_addr);
-                buf_discard(rbuf);
+
+        if ((type == DSC_REQ_MSG) && !link_fully_up) {
+                rbuf = tipc_disc_init_msg(DSC_RESP_MSG, orig, b_ptr);
+                if (rbuf) {
+                        b_ptr->media->send_msg(rbuf, b_ptr, &media_addr);
+                        buf_discard(rbuf);
+                }
         }
+
+        tipc_node_unlock(n_ptr);
 }
 
 /**