tipc: Fix port counter handling to correct congestion control

Modifies TIPC's congestion control between a connected port and its
peer so that it works as documented. The following changes have been
made:

1) The counter of the number of messages sent by a port now starts
   at zero, rather than one. This prevents the port from reporting port
   congestion one message earlier than it was supposed to.

2) The counter of the number of messages sent by a port is now
   incremented only if a non-empty message is sent successfully.
   This prevents the port from becoming permanently congested if
   too many send attempts are unsuccessful because of congestion
   (or other reasons). It also removes the risk that empty hand-
   shaking messages used during connection setup might cause the
   port to report congestion earlier than it was supposed to.

3) The counter of the number of unacknowledged messages received by
   a port controlled by an internal TIPC service is now incremented
   only if the message is non-empty, in order to be consistent with
   the aforementioned changes.

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

1 files changed, 2 insertions, 2 deletions

diff --git a/net/tipc/port.h b/net/tipc/port.h
index f8722af..34ccb7c 100644
--- a/net/tipc/port.h
+++ b/net/tipc/port.h
@@ -113,8 +113,8 @@ struct user_port {
  * @user_port: ptr to user port associated with port (if any)
  * @wait_list: adjacent ports in list of ports waiting on link congestion
  * @waiting_pkts:
- * @sent:
- * @acked:
+ * @sent: # of non-empty messages sent by port
+ * @acked: # of non-empty message acknowledgements from connected port's peer
  * @publications: list of publications for port
  * @pub_count: total # of publications port has made during its lifetime
  * @probing_state: