totemsrp: Only restore old ring id information one time

The current code stores the current ring information every time a commit
token is generated.  This causes the old ring id used for comparison purposes
to increase if a token is lost in commit or recovery, resulting in failure of
totem.  This patch changes the behavior to only store the old ring id one
time when the commit token is received, and then further commit token ring
id saves are not done until OPERATIONAL is reached.

Signed-off-by: Steven Dake <sdake@redhat.com>
Reviewed-by: Jan Friesse <jfriesse@redhat.com>

exec/totemsrp.c

@@ -475,6 +475,8 @@ struct totemsrp_instance {
 
 	unsigned int set_aru;
 
+	int old_ring_state_saved;
+
 	int old_ring_state_aru;
 
 	unsigned int old_ring_state_high_seq_received;
@@ -1411,13 +1413,16 @@ static void cancel_merge_detect_timeout (struct totemsrp_instance *instance)
  */
 static void old_ring_state_save (struct totemsrp_instance *instance)
 {
-	memcpy (&instance->my_old_ring_id, &instance->my_ring_id,
-		sizeof (struct memb_ring_id));
-	instance->old_ring_state_aru = instance->my_aru;
-	instance->old_ring_state_high_seq_received = instance->my_high_seq_received;
-	log_printf (instance->totemsrp_log_level_debug,
-		"Saving state aru %x high seq received %x\n",
-		instance->my_aru, instance->my_high_seq_received);
+	if (instance->old_ring_state_saved == 0) {
+		instance->old_ring_state_saved = 1;
+		memcpy (&instance->my_old_ring_id, &instance->my_ring_id,
+			sizeof (struct memb_ring_id));
+		instance->old_ring_state_aru = instance->my_aru;
+		instance->old_ring_state_high_seq_received = instance->my_high_seq_received;
+		log_printf (instance->totemsrp_log_level_debug,
+			"Saving state aru %x high seq received %x\n",
+			instance->my_aru, instance->my_high_seq_received);
+	}
 }
 
 static void old_ring_state_restore (struct totemsrp_instance *instance)
@@ -1433,6 +1438,7 @@ static void old_ring_state_reset (struct totemsrp_instance *instance)
 {
 	log_printf (instance->totemsrp_log_level_debug,
 		"Resetting old ring state\n");
+	instance->old_ring_state_saved = 0;
 }
 
 static void reset_pause_timeout (struct totemsrp_instance *instance)