cpg: Process join list after downlists

let's say following situation will happen:
- we have 3 nodes
- on wire messages looks like D1,J1,D2,J2,D3,J3 (D is downlist, J is
  joinlist)
- let's say, D1 and D3 contains node 2
- it means that J2 is applied, but right after that, D1 (or D3) is
  applied what means, node 2 is again considered down

It's solved by collecting joinlists and apply them after downlist, so
order is:
- apply best matching downlist
- apply all joinlists

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

exec/cpg.c

@@ -143,6 +143,7 @@ enum cpg_downlist_state_e {
 };
 static enum cpg_downlist_state_e downlist_state;
 static struct list_head downlist_messages_head;
+static struct list_head joinlist_messages_head;
 
 struct cpg_pd {
 	void *conn;
@@ -285,6 +286,10 @@ static void downlist_messages_delete (void);
 
 static void downlist_master_choose_and_send (void);
 
+static void joinlist_inform_clients (void);
+
+static void joinlist_messages_delete (void);
+
 static void cpg_sync_init (
 	const unsigned int *trans_list,
 	size_t trans_list_entries,
@@ -298,6 +303,12 @@ static void cpg_sync_activate (void);
 
 static void cpg_sync_abort (void);
 
+static void do_proc_join(
+	const mar_cpg_name_t *name,
+	uint32_t pid,
+	unsigned int nodeid,
+	int reason);
+
 static int notify_lib_totem_membership (
 	void *conn,
 	int member_list_entries,
@@ -456,6 +467,13 @@ struct downlist_msg {
 	struct list_head list;
 };
 
+struct joinlist_msg {
+	mar_uint32_t sender_nodeid;
+	uint32_t pid;
+	mar_cpg_name_t group_name;
+	struct list_head list;
+};
+
 static struct req_exec_cpg_downlist g_req_exec_cpg_downlist;
 
 static void cpg_sync_init (
@@ -527,8 +545,11 @@ static void cpg_sync_activate (void)
 		downlist_master_choose_and_send ();
 	}
 
+	joinlist_inform_clients ();
+
 	downlist_messages_delete ();
 	downlist_state = CPG_DOWNLIST_NONE;
+	joinlist_messages_delete ();
 
 	notify_lib_totem_membership (NULL, my_member_list_entries, my_member_list);
 }
@@ -537,6 +558,7 @@ static void cpg_sync_abort (void)
 {
 	downlist_state = CPG_DOWNLIST_NONE;
 	downlist_messages_delete ();
+	joinlist_messages_delete ();
 }
 
 static int notify_lib_totem_membership (
@@ -865,6 +887,34 @@ static void downlist_master_choose_and_send (void)
 	qb_map_destroy(group_map);
 }
 
+static void joinlist_inform_clients (void)
+{
+	struct joinlist_msg *stored_msg;
+	struct list_head *iter;
+	unsigned int i;
+
+	i = 0;
+	for (iter = joinlist_messages_head.next;
+		iter != &joinlist_messages_head;
+		iter = iter->next) {
+
+		stored_msg = list_entry(iter, struct joinlist_msg, list);
+
+		log_printf (LOG_DEBUG, "joinlist_messages[%u] group:%d, ip:%s, pid:%d",
+			i++, stored_msg->group_name.value,
+			(char*)api->totem_ifaces_print(stored_msg->sender_nodeid),
+			stored_msg->pid);
+
+		/* Ignore our own messages */
+		if (stored_msg->sender_nodeid == api->totem_nodeid_get()) {
+			continue ;
+		}
+
+		do_proc_join (&stored_msg->group_name, stored_msg->pid, stored_msg->sender_nodeid,
+			CONFCHG_CPG_REASON_NODEUP);
+	}
+}
+
 static void downlist_messages_delete (void)
 {
 	struct downlist_msg *stored_msg;
@@ -882,6 +932,23 @@ static void downlist_messages_delete (void)
 	}
 }
 
+static void joinlist_messages_delete (void)
+{
+	struct joinlist_msg *stored_msg;
+	struct list_head *iter, *iter_next;
+
+	for (iter = joinlist_messages_head.next;
+		iter != &joinlist_messages_head;
+		iter = iter_next) {
+
+		iter_next = iter->next;
+
+		stored_msg = list_entry(iter, struct joinlist_msg, list);
+		list_del (&stored_msg->list);
+		free (stored_msg);
+	}
+	list_init (&joinlist_messages_head);
+}
 
 static char *cpg_exec_init_fn (struct corosync_api_v1 *corosync_api)
 {
@@ -889,6 +956,7 @@ static char *cpg_exec_init_fn (struct corosync_api_v1 *corosync_api)
 	logsys_subsys_init();
 #endif
 	list_init (&downlist_messages_head);
+	list_init (&joinlist_messages_head);
 	api = corosync_api;
 	return (NULL);
 }
@@ -1199,18 +1267,19 @@ static void message_handler_req_exec_cpg_joinlist (
 	const char *message = message_v;
 	const struct qb_ipc_response_header *res = (const struct qb_ipc_response_header *)message;
 	const struct join_list_entry *jle = (const struct join_list_entry *)(message + sizeof(struct qb_ipc_response_header));
+	struct joinlist_msg *stored_msg;
 
 	log_printf(LOGSYS_LEVEL_DEBUG, "got joinlist message from node %x",
 		nodeid);
 
-	/* Ignore our own messages */
-	if (nodeid == api->totem_nodeid_get()) {
-		return;
-	}
-
 	while ((const char*)jle < message + res->size) {
-		do_proc_join (&jle->group_name, jle->pid, nodeid,
-			CONFCHG_CPG_REASON_NODEUP);
+		stored_msg = malloc (sizeof (struct joinlist_msg));
+		memset(stored_msg, 0, sizeof (struct joinlist_msg));
+		stored_msg->sender_nodeid = nodeid;
+		stored_msg->pid = jle->pid;
+		memcpy(&stored_msg->group_name, &jle->group_name, sizeof(mar_cpg_name_t));
+		list_init (&stored_msg->list);
+		list_add (&stored_msg->list, &joinlist_messages_head);
 		jle++;
 	}
 }