tipc: simplify link supervision checkpointing

We change the sequence number checkpointing that is performed
by the timer in order to discover if the peer is active. Currently,
we store a checkpoint of the next expected sequence number "rcv_nxt"
at each timer expiration, and compare it to the current expected
number at next timeout expiration. Instead, we now use the already
existing field "silent_intv_cnt" for this task. We step the counter
at each timeout expiration, and zero it at each valid received packet.
If no valid packet has been received from the peer after "abort_limit"
number of silent timer intervals, the link is declared faulty and reset.

We also remove the multiple instances of timer activation from inside
the FSM function "link_state_event()", and now do it at only one place;
at the end of the timer function itself.

Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-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>

1 files changed, 0 insertions, 2 deletions

diff --git a/net/tipc/link.h b/net/tipc/link.h
index 74d2d12fc120..0c02c973e985 100644
--- a/net/tipc/link.h
+++ b/net/tipc/link.h
@@ -107,7 +107,6 @@ struct tipc_stats {
  * @owner: pointer to peer node
  * @refcnt: reference counter for permanent references (owner node & timer)
  * @flags: execution state flags for link endpoint instance
- * @checkpoint: reference point for triggering link continuity checking
  * @peer_session: link session # being used by peer end of link
  * @peer_bearer_id: bearer id used by link's peer endpoint
  * @bearer_id: local bearer id used by link
@@ -151,7 +150,6 @@ struct tipc_link {
 
 	/* Management and link supervision data */
 	unsigned int flags;
-	u16 checkpoint;
 	u32 peer_session;
 	u32 peer_bearer_id;
 	u32 bearer_id;