Merge branch 'tipc-topology-updates'

Parthasarathy Bhuvaragan says:

====================
tipc: cleanups, fixes & improvements for topology server

This series contains topology server cleanups, fixes and improvements.

Cleanups in #1-#4:
We remove duplicate data structures and aligin the rest of the code accordingly.

Fixes in #5-#8:
The bugs occur either during configuration or while running on SMP targets,
which are race conditions that pop up under different situations.

Improvements in #9-#10:
Updates to decrease timer usage and improve readability.

v2: Updated commit message in patch 6 based on feedback from
    Sergei Shtylyov sergei.shtylyov@cogentembedded.com
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/name_table.c

@@ -418,6 +418,9 @@ static void tipc_nameseq_subscribe(struct name_seq *nseq,
 				   struct tipc_subscription *s)
 {
 	struct sub_seq *sseq = nseq->sseqs;
+	struct tipc_name_seq ns;
+
+	tipc_subscrp_convert_seq(&s->evt.s.seq, s->swap, &ns);
 
 	list_add(&s->nameseq_list, &nseq->subscriptions);
 
@@ -425,7 +428,7 @@ static void tipc_nameseq_subscribe(struct name_seq *nseq,
 		return;
 
 	while (sseq != &nseq->sseqs[nseq->first_free]) {
-		if (tipc_subscrp_check_overlap(s, sseq->lower, sseq->upper)) {
+		if (tipc_subscrp_check_overlap(&ns, sseq->lower, sseq->upper)) {
 			struct publication *crs;
 			struct name_info *info = sseq->info;
 			int must_report = 1;
@@ -722,9 +725,10 @@ int tipc_nametbl_withdraw(struct net *net, u32 type, u32 lower, u32 ref,
 void tipc_nametbl_subscribe(struct tipc_subscription *s)
 {
 	struct tipc_net *tn = net_generic(s->net, tipc_net_id);
-	u32 type = s->seq.type;
+	u32 type = tipc_subscrp_convert_seq_type(s->evt.s.seq.type, s->swap);
 	int index = hash(type);
 	struct name_seq *seq;
+	struct tipc_name_seq ns;
 
 	spin_lock_bh(&tn->nametbl_lock);
 	seq = nametbl_find_seq(s->net, type);
@@ -735,8 +739,9 @@ void tipc_nametbl_subscribe(struct tipc_subscription *s)
 		tipc_nameseq_subscribe(seq, s);
 		spin_unlock_bh(&seq->lock);
 	} else {
+		tipc_subscrp_convert_seq(&s->evt.s.seq, s->swap, &ns);
 		pr_warn("Failed to create subscription for {%u,%u,%u}\n",
-			s->seq.type, s->seq.lower, s->seq.upper);
+			ns.type, ns.lower, ns.upper);
 	}
 	spin_unlock_bh(&tn->nametbl_lock);
 }
@@ -748,9 +753,10 @@ void tipc_nametbl_unsubscribe(struct tipc_subscription *s)
 {
 	struct tipc_net *tn = net_generic(s->net, tipc_net_id);
 	struct name_seq *seq;
+	u32 type = tipc_subscrp_convert_seq_type(s->evt.s.seq.type, s->swap);
 
 	spin_lock_bh(&tn->nametbl_lock);
-	seq = nametbl_find_seq(s->net, s->seq.type);
+	seq = nametbl_find_seq(s->net, type);
 	if (seq != NULL) {
 		spin_lock_bh(&seq->lock);
 		list_del_init(&s->nameseq_list);

net/tipc/server.c

@@ -571,13 +571,13 @@ static void tipc_work_stop(struct tipc_server *s)
 
 static int tipc_work_start(struct tipc_server *s)
 {
-	s->rcv_wq = alloc_workqueue("tipc_rcv", WQ_UNBOUND, 1);
+	s->rcv_wq = alloc_ordered_workqueue("tipc_rcv", 0);
 	if (!s->rcv_wq) {
 		pr_err("can't start tipc receive workqueue\n");
 		return -ENOMEM;
 	}
 
-	s->send_wq = alloc_workqueue("tipc_send", WQ_UNBOUND, 1);
+	s->send_wq = alloc_ordered_workqueue("tipc_send", 0);
 	if (!s->send_wq) {
 		pr_err("can't start tipc send workqueue\n");
 		destroy_workqueue(s->rcv_wq);

net/tipc/subscr.c

@@ -92,25 +92,42 @@ static void tipc_subscrp_send_event(struct tipc_subscription *sub,
  *
  * Returns 1 if there is overlap, otherwise 0.
  */
-int tipc_subscrp_check_overlap(struct tipc_subscription *sub, u32 found_lower,
+int tipc_subscrp_check_overlap(struct tipc_name_seq *seq, u32 found_lower,
 			       u32 found_upper)
 {
-	if (found_lower < sub->seq.lower)
-		found_lower = sub->seq.lower;
-	if (found_upper > sub->seq.upper)
-		found_upper = sub->seq.upper;
+	if (found_lower < seq->lower)
+		found_lower = seq->lower;
+	if (found_upper > seq->upper)
+		found_upper = seq->upper;
 	if (found_lower > found_upper)
 		return 0;
 	return 1;
 }
 
+u32 tipc_subscrp_convert_seq_type(u32 type, int swap)
+{
+	return htohl(type, swap);
+}
+
+void tipc_subscrp_convert_seq(struct tipc_name_seq *in, int swap,
+			      struct tipc_name_seq *out)
+{
+	out->type = htohl(in->type, swap);
+	out->lower = htohl(in->lower, swap);
+	out->upper = htohl(in->upper, swap);
+}
+
 void tipc_subscrp_report_overlap(struct tipc_subscription *sub, u32 found_lower,
 				 u32 found_upper, u32 event, u32 port_ref,
 				 u32 node, int must)
 {
-	if (!tipc_subscrp_check_overlap(sub, found_lower, found_upper))
+	struct tipc_name_seq seq;
+
+	tipc_subscrp_convert_seq(&sub->evt.s.seq, sub->swap, &seq);
+	if (!tipc_subscrp_check_overlap(&seq, found_lower, found_upper))
 		return;
-	if (!must && !(sub->filter & TIPC_SUB_PORTS))
+	if (!must &&
+	    !(htohl(sub->evt.s.filter, sub->swap) & TIPC_SUB_PORTS))
 		return;
 
 	tipc_subscrp_send_event(sub, found_lower, found_upper, event, port_ref,
@@ -171,12 +188,14 @@ static struct tipc_subscriber *tipc_subscrb_create(int conid)
 static void tipc_subscrb_delete(struct tipc_subscriber *subscriber)
 {
 	struct tipc_subscription *sub, *temp;
+	u32 timeout;
 
 	spin_lock_bh(&subscriber->lock);
 	/* Destroy any existing subscriptions for subscriber */
 	list_for_each_entry_safe(sub, temp, &subscriber->subscrp_list,
 				 subscrp_list) {
-		if (del_timer(&sub->timer)) {
+		timeout = htohl(sub->evt.s.timeout, sub->swap);
+		if ((timeout == TIPC_WAIT_FOREVER) || del_timer(&sub->timer)) {
 			tipc_subscrp_delete(sub);
 			tipc_subscrb_put(subscriber);
 		}
@@ -200,13 +219,16 @@ static void tipc_subscrp_cancel(struct tipc_subscr *s,
 				struct tipc_subscriber *subscriber)
 {
 	struct tipc_subscription *sub, *temp;
+	u32 timeout;
 
 	spin_lock_bh(&subscriber->lock);
 	/* Find first matching subscription, exit if not found */
 	list_for_each_entry_safe(sub, temp, &subscriber->subscrp_list,
 				 subscrp_list) {
 		if (!memcmp(s, &sub->evt.s, sizeof(struct tipc_subscr))) {
-			if (del_timer(&sub->timer)) {
+			timeout = htohl(sub->evt.s.timeout, sub->swap);
+			if ((timeout == TIPC_WAIT_FOREVER) ||
+			    del_timer(&sub->timer)) {
 				tipc_subscrp_delete(sub);
 				tipc_subscrb_put(subscriber);
 			}
@@ -216,66 +238,67 @@ static void tipc_subscrp_cancel(struct tipc_subscr *s,
 	spin_unlock_bh(&subscriber->lock);
 }
 
-static int tipc_subscrp_create(struct net *net, struct tipc_subscr *s,
-			       struct tipc_subscriber *subscriber,
-			       struct tipc_subscription **sub_p)
+static struct tipc_subscription *tipc_subscrp_create(struct net *net,
+						     struct tipc_subscr *s,
+						     int swap)
 {
 	struct tipc_net *tn = net_generic(net, tipc_net_id);
 	struct tipc_subscription *sub;
-	int swap;
-
-	/* Determine subscriber's endianness */
-	swap = !(s->filter & (TIPC_SUB_PORTS | TIPC_SUB_SERVICE));
-
-	/* Detect & process a subscription cancellation request */
-	if (s->filter & htohl(TIPC_SUB_CANCEL, swap)) {
-		s->filter &= ~htohl(TIPC_SUB_CANCEL, swap);
-		tipc_subscrp_cancel(s, subscriber);
-		return 0;
-	}
+	u32 filter = htohl(s->filter, swap);
 
 	/* Refuse subscription if global limit exceeded */
 	if (atomic_read(&tn->subscription_count) >= TIPC_MAX_SUBSCRIPTIONS) {
 		pr_warn("Subscription rejected, limit reached (%u)\n",
 			TIPC_MAX_SUBSCRIPTIONS);
-		return -EINVAL;
+		return NULL;
 	}
 
 	/* Allocate subscription object */
 	sub = kmalloc(sizeof(*sub), GFP_ATOMIC);
 	if (!sub) {
 		pr_warn("Subscription rejected, no memory\n");
-		return -ENOMEM;
+		return NULL;
 	}
 
 	/* Initialize subscription object */
 	sub->net = net;
-	sub->seq.type = htohl(s->seq.type, swap);
-	sub->seq.lower = htohl(s->seq.lower, swap);
-	sub->seq.upper = htohl(s->seq.upper, swap);
-	sub->timeout = msecs_to_jiffies(htohl(s->timeout, swap));
-	sub->filter = htohl(s->filter, swap);
-	if ((!(sub->filter & TIPC_SUB_PORTS) ==
-	     !(sub->filter & TIPC_SUB_SERVICE)) ||
-	    (sub->seq.lower > sub->seq.upper)) {
+	if (((filter & TIPC_SUB_PORTS) && (filter & TIPC_SUB_SERVICE)) ||
+	    (htohl(s->seq.lower, swap) > htohl(s->seq.upper, swap))) {
 		pr_warn("Subscription rejected, illegal request\n");
 		kfree(sub);
-		return -EINVAL;
+		return NULL;
 	}
-	spin_lock_bh(&subscriber->lock);
-	list_add(&sub->subscrp_list, &subscriber->subscrp_list);
-	spin_unlock_bh(&subscriber->lock);
-	sub->subscriber = subscriber;
+
 	sub->swap = swap;
 	memcpy(&sub->evt.s, s, sizeof(*s));
 	atomic_inc(&tn->subscription_count);
-	setup_timer(&sub->timer, tipc_subscrp_timeout, (unsigned long)sub);
-	if (sub->timeout != TIPC_WAIT_FOREVER)
-		sub->timeout += jiffies;
-	if (!mod_timer(&sub->timer, sub->timeout))
+	return sub;
+}
+
+static void tipc_subscrp_subscribe(struct net *net, struct tipc_subscr *s,
+				   struct tipc_subscriber *subscriber, int swap)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct tipc_subscription *sub = NULL;
+	u32 timeout;
+
+	sub = tipc_subscrp_create(net, s, swap);
+	if (!sub)
+		return tipc_conn_terminate(tn->topsrv, subscriber->conid);
+
+	spin_lock_bh(&subscriber->lock);
+	list_add(&sub->subscrp_list, &subscriber->subscrp_list);
 	tipc_subscrb_get(subscriber);
-	*sub_p = sub;
-	return 0;
+	sub->subscriber = subscriber;
+	tipc_nametbl_subscribe(sub);
+	spin_unlock_bh(&subscriber->lock);
+
+	timeout = htohl(sub->evt.s.timeout, swap);
+	if (timeout == TIPC_WAIT_FOREVER)
+		return;
+
+	setup_timer(&sub->timer, tipc_subscrp_timeout, (unsigned long)sub);
+	mod_timer(&sub->timer, jiffies + msecs_to_jiffies(timeout));
 }
 
 /* Handle one termination request for the subscriber */
@@ -289,14 +312,21 @@ static void tipc_subscrb_rcv_cb(struct net *net, int conid,
 				struct sockaddr_tipc *addr, void *usr_data,
 				void *buf, size_t len)
 {
-	struct tipc_subscriber *subscrb = usr_data;
-	struct tipc_subscription *sub = NULL;
-	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct tipc_subscriber *subscriber = usr_data;
+	struct tipc_subscr *s = (struct tipc_subscr *)buf;
+	int swap;
 
-	if (tipc_subscrp_create(net, (struct tipc_subscr *)buf, subscrb, &sub))
-		return tipc_conn_terminate(tn->topsrv, subscrb->conid);
+	/* Determine subscriber's endianness */
+	swap = !(s->filter & (TIPC_SUB_PORTS | TIPC_SUB_SERVICE |
+			      TIPC_SUB_CANCEL));
 
-	tipc_nametbl_subscribe(sub);
+	/* Detect & process a subscription cancellation request */
+	if (s->filter & htohl(TIPC_SUB_CANCEL, swap)) {
+		s->filter &= ~htohl(TIPC_SUB_CANCEL, swap);
+		return tipc_subscrp_cancel(s, subscriber);
+	}
+
+	tipc_subscrp_subscribe(net, s, subscriber, swap);
 }
 
 /* Handle one request to establish a new subscriber */

net/tipc/subscr.h

@@ -50,21 +50,15 @@ struct tipc_subscriber;
  * @subscriber: pointer to its subscriber
  * @seq: name sequence associated with subscription
  * @net: point to network namespace
- * @timeout: duration of subscription (in ms)
- * @filter: event filtering to be done for subscription
  * @timer: timer governing subscription duration (optional)
  * @nameseq_list: adjacent subscriptions in name sequence's subscription list
  * @subscrp_list: adjacent subscriptions in subscriber's subscription list
- * @server_ref: object reference of server port associated with subscription
  * @swap: indicates if subscriber uses opposite endianness in its messages
  * @evt: template for events generated by subscription
  */
 struct tipc_subscription {
 	struct tipc_subscriber *subscriber;
-	struct tipc_name_seq seq;
 	struct net *net;
-	unsigned long timeout;
-	u32 filter;
 	struct timer_list timer;
 	struct list_head nameseq_list;
 	struct list_head subscrp_list;
@@ -72,11 +66,14 @@ struct tipc_subscription {
 	struct tipc_event evt;
 };
 
-int tipc_subscrp_check_overlap(struct tipc_subscription *sub, u32 found_lower,
+int tipc_subscrp_check_overlap(struct tipc_name_seq *seq, u32 found_lower,
 			       u32 found_upper);
 void tipc_subscrp_report_overlap(struct tipc_subscription *sub,
 				 u32 found_lower, u32 found_upper, u32 event,
 				 u32 port_ref, u32 node, int must);
+void tipc_subscrp_convert_seq(struct tipc_name_seq *in, int swap,
+			      struct tipc_name_seq *out);
+u32 tipc_subscrp_convert_seq_type(u32 type, int swap);
 int tipc_topsrv_start(struct net *net);
 void tipc_topsrv_stop(struct net *net);