1 files changed, 110 insertions, 132 deletions

diff --git a/net/tipc/subscr.c b/net/tipc/subscr.c
index 1c147c869c2e..350cca33ee0a 100644
--- a/net/tipc/subscr.c
+++ b/net/tipc/subscr.c
@@ -40,16 +40,21 @@
 
 /**
  * struct tipc_subscriber - TIPC network topology subscriber
+ * @kref: reference counter to tipc_subscription object
  * @conid: connection identifier to server connecting to subscriber
  * @lock: control access to subscriber
- * @subscription_list: list of subscription objects for this subscriber
+ * @subscrp_list: list of subscription objects for this subscriber
  */
 struct tipc_subscriber {
+	struct kref kref;
 	int conid;
 	spinlock_t lock;
-	struct list_head subscription_list;
+	struct list_head subscrp_list;
 };
 
+static void tipc_subscrp_delete(struct tipc_subscription *sub);
+static void tipc_subscrb_put(struct tipc_subscriber *subscriber);
+
 /**
  * htohl - convert value to endianness used by destination
  * @in: value to convert
@@ -62,9 +67,9 @@ static u32 htohl(u32 in, int swap)
 	return swap ? swab32(in) : in;
 }
 
-static void subscr_send_event(struct tipc_subscription *sub, u32 found_lower,
-			      u32 found_upper, u32 event, u32 port_ref,
-			      u32 node)
+static void tipc_subscrp_send_event(struct tipc_subscription *sub,
+				    u32 found_lower, u32 found_upper,
+				    u32 event, u32 port_ref, u32 node)
 {
 	struct tipc_net *tn = net_generic(sub->net, tipc_net_id);
 	struct tipc_subscriber *subscriber = sub->subscriber;
@@ -82,12 +87,13 @@ static void subscr_send_event(struct tipc_subscription *sub, u32 found_lower,
 }
 
 /**
- * tipc_subscr_overlap - test for subscription overlap with the given values
+ * tipc_subscrp_check_overlap - test for subscription overlap with the
+ * given values
  *
  * Returns 1 if there is overlap, otherwise 0.
  */
-int tipc_subscr_overlap(struct tipc_subscription *sub, u32 found_lower,
-			u32 found_upper)
+int tipc_subscrp_check_overlap(struct tipc_subscription *sub, u32 found_lower,
+			       u32 found_upper)
 {
 	if (found_lower < sub->seq.lower)
 		found_lower = sub->seq.lower;
@@ -98,138 +104,121 @@ int tipc_subscr_overlap(struct tipc_subscription *sub, u32 found_lower,
 	return 1;
 }
 
-/**
- * tipc_subscr_report_overlap - issue event if there is subscription overlap
- *
- * Protected by nameseq.lock in name_table.c
- */
-void tipc_subscr_report_overlap(struct tipc_subscription *sub, u32 found_lower,
-				u32 found_upper, u32 event, u32 port_ref,
-				u32 node, int must)
+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_subscr_overlap(sub, found_lower, found_upper))
+	if (!tipc_subscrp_check_overlap(sub, found_lower, found_upper))
 		return;
 	if (!must && !(sub->filter & TIPC_SUB_PORTS))
 		return;
 
-	subscr_send_event(sub, found_lower, found_upper, event, port_ref, node);
+	tipc_subscrp_send_event(sub, found_lower, found_upper, event, port_ref,
+				node);
 }
 
-static void subscr_timeout(unsigned long data)
+static void tipc_subscrp_timeout(unsigned long data)
 {
 	struct tipc_subscription *sub = (struct tipc_subscription *)data;
 	struct tipc_subscriber *subscriber = sub->subscriber;
-	struct tipc_net *tn = net_generic(sub->net, tipc_net_id);
 
-	/* The spin lock per subscriber is used to protect its members */
-	spin_lock_bh(&subscriber->lock);
+	/* Notify subscriber of timeout */
+	tipc_subscrp_send_event(sub, sub->evt.s.seq.lower, sub->evt.s.seq.upper,
+				TIPC_SUBSCR_TIMEOUT, 0, 0);
 
-	/* Validate timeout (in case subscription is being cancelled) */
-	if (sub->timeout == TIPC_WAIT_FOREVER) {
-		spin_unlock_bh(&subscriber->lock);
-		return;
-	}
+	spin_lock_bh(&subscriber->lock);
+	tipc_subscrp_delete(sub);
+	spin_unlock_bh(&subscriber->lock);
 
-	/* Unlink subscription from name table */
-	tipc_nametbl_unsubscribe(sub);
+	tipc_subscrb_put(subscriber);
+}
 
-	/* Unlink subscription from subscriber */
-	list_del(&sub->subscription_list);
+static void tipc_subscrb_kref_release(struct kref *kref)
+{
+	struct tipc_subscriber *subcriber = container_of(kref,
+					    struct tipc_subscriber, kref);
 
-	spin_unlock_bh(&subscriber->lock);
+	kfree(subcriber);
+}
 
-	/* Notify subscriber of timeout */
-	subscr_send_event(sub, sub->evt.s.seq.lower, sub->evt.s.seq.upper,
-			  TIPC_SUBSCR_TIMEOUT, 0, 0);
+static void tipc_subscrb_put(struct tipc_subscriber *subscriber)
+{
+	kref_put(&subscriber->kref, tipc_subscrb_kref_release);
+}
 
-	/* Now destroy subscription */
-	kfree(sub);
-	atomic_dec(&tn->subscription_count);
+static void tipc_subscrb_get(struct tipc_subscriber *subscriber)
+{
+	kref_get(&subscriber->kref);
 }
 
-/**
- * subscr_del - delete a subscription within a subscription list
- *
- * Called with subscriber lock held.
- */
-static void subscr_del(struct tipc_subscription *sub)
+static struct tipc_subscriber *tipc_subscrb_create(int conid)
 {
-	struct tipc_net *tn = net_generic(sub->net, tipc_net_id);
+	struct tipc_subscriber *subscriber;
 
-	tipc_nametbl_unsubscribe(sub);
-	list_del(&sub->subscription_list);
-	kfree(sub);
-	atomic_dec(&tn->subscription_count);
+	subscriber = kzalloc(sizeof(*subscriber), GFP_ATOMIC);
+	if (!subscriber) {
+		pr_warn("Subscriber rejected, no memory\n");
+		return NULL;
+	}
+	kref_init(&subscriber->kref);
+	INIT_LIST_HEAD(&subscriber->subscrp_list);
+	subscriber->conid = conid;
+	spin_lock_init(&subscriber->lock);
+
+	return subscriber;
 }
 
-static void subscr_release(struct tipc_subscriber *subscriber)
+static void tipc_subscrb_delete(struct tipc_subscriber *subscriber)
 {
-	struct tipc_subscription *sub;
-	struct tipc_subscription *sub_temp;
+	struct tipc_subscription *sub, *temp;
 
 	spin_lock_bh(&subscriber->lock);
-
 	/* Destroy any existing subscriptions for subscriber */
-	list_for_each_entry_safe(sub, sub_temp, &subscriber->subscription_list,
-				 subscription_list) {
-		if (sub->timeout != TIPC_WAIT_FOREVER) {
-			spin_unlock_bh(&subscriber->lock);
-			del_timer_sync(&sub->timer);
-			spin_lock_bh(&subscriber->lock);
+	list_for_each_entry_safe(sub, temp, &subscriber->subscrp_list,
+				 subscrp_list) {
+		if (del_timer(&sub->timer)) {
+			tipc_subscrp_delete(sub);
+			tipc_subscrb_put(subscriber);
 		}
-		subscr_del(sub);
 	}
 	spin_unlock_bh(&subscriber->lock);
 
-	/* Now destroy subscriber */
-	kfree(subscriber);
+	tipc_subscrb_put(subscriber);
 }
 
-/**
- * subscr_cancel - handle subscription cancellation request
- *
- * Called with subscriber lock held. Routine must temporarily release lock
- * to enable the subscription timeout routine to finish without deadlocking;
- * the lock is then reclaimed to allow caller to release it upon return.
- *
- * Note that fields of 's' use subscriber's endianness!
- */
-static void subscr_cancel(struct tipc_subscr *s,
-			  struct tipc_subscriber *subscriber)
+static void tipc_subscrp_delete(struct tipc_subscription *sub)
 {
-	struct tipc_subscription *sub;
-	struct tipc_subscription *sub_temp;
-	int found = 0;
+	struct tipc_net *tn = net_generic(sub->net, tipc_net_id);
+
+	tipc_nametbl_unsubscribe(sub);
+	list_del(&sub->subscrp_list);
+	kfree(sub);
+	atomic_dec(&tn->subscription_count);
+}
 
+static void tipc_subscrp_cancel(struct tipc_subscr *s,
+				struct tipc_subscriber *subscriber)
+{
+	struct tipc_subscription *sub, *temp;
+
+	spin_lock_bh(&subscriber->lock);
 	/* Find first matching subscription, exit if not found */
-	list_for_each_entry_safe(sub, sub_temp, &subscriber->subscription_list,
-				 subscription_list) {
+	list_for_each_entry_safe(sub, temp, &subscriber->subscrp_list,
+				 subscrp_list) {
 		if (!memcmp(s, &sub->evt.s, sizeof(struct tipc_subscr))) {
-			found = 1;
+			if (del_timer(&sub->timer)) {
+				tipc_subscrp_delete(sub);
+				tipc_subscrb_put(subscriber);
+			}
 			break;
 		}
 	}
-	if (!found)
-		return;
-
-	/* Cancel subscription timer (if used), then delete subscription */
-	if (sub->timeout != TIPC_WAIT_FOREVER) {
-		sub->timeout = TIPC_WAIT_FOREVER;
-		spin_unlock_bh(&subscriber->lock);
-		del_timer_sync(&sub->timer);
-		spin_lock_bh(&subscriber->lock);
-	}
-	subscr_del(sub);
+	spin_unlock_bh(&subscriber->lock);
 }
 
-/**
- * subscr_subscribe - create subscription for subscriber
- *
- * Called with subscriber lock held.
- */
-static int subscr_subscribe(struct net *net, struct tipc_subscr *s,
-			    struct tipc_subscriber *subscriber,
-			    struct tipc_subscription **sub_p)
+static int tipc_subscrp_create(struct net *net, struct tipc_subscr *s,
+			       struct tipc_subscriber *subscriber,
+			       struct tipc_subscription **sub_p)
 {
 	struct tipc_net *tn = net_generic(net, tipc_net_id);
 	struct tipc_subscription *sub;
@@ -241,7 +230,7 @@ static int subscr_subscribe(struct net *net, struct tipc_subscr *s,
 	/* Detect & process a subscription cancellation request */
 	if (s->filter & htohl(TIPC_SUB_CANCEL, swap)) {
 		s->filter &= ~htohl(TIPC_SUB_CANCEL, swap);
-		subscr_cancel(s, subscriber);
+		tipc_subscrp_cancel(s, subscriber);
 		return 0;
 	}
 
@@ -273,62 +262,51 @@ static int subscr_subscribe(struct net *net, struct tipc_subscr *s,
 		kfree(sub);
 		return -EINVAL;
 	}
-	list_add(&sub->subscription_list, &subscriber->subscription_list);
+	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(struct tipc_subscr));
+	memcpy(&sub->evt.s, s, sizeof(*s));
 	atomic_inc(&tn->subscription_count);
-	if (sub->timeout != TIPC_WAIT_FOREVER) {
-		setup_timer(&sub->timer, subscr_timeout, (unsigned long)sub);
-		mod_timer(&sub->timer, jiffies + sub->timeout);
-	}
+	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))
+		tipc_subscrb_get(subscriber);
 	*sub_p = sub;
 	return 0;
 }
 
 /* Handle one termination request for the subscriber */
-static void subscr_conn_shutdown_event(int conid, void *usr_data)
+static void tipc_subscrb_shutdown_cb(int conid, void *usr_data)
 {
-	subscr_release((struct tipc_subscriber *)usr_data);
+	tipc_subscrb_delete((struct tipc_subscriber *)usr_data);
 }
 
 /* Handle one request to create a new subscription for the subscriber */
-static void subscr_conn_msg_event(struct net *net, int conid,
-				  struct sockaddr_tipc *addr, void *usr_data,
-				  void *buf, size_t len)
+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 *subscriber = usr_data;
 	struct tipc_subscription *sub = NULL;
 	struct tipc_net *tn = net_generic(net, tipc_net_id);
 
-	spin_lock_bh(&subscriber->lock);
-	subscr_subscribe(net, (struct tipc_subscr *)buf, subscriber, &sub);
+	tipc_subscrp_create(net, (struct tipc_subscr *)buf, subscriber, &sub);
 	if (sub)
 		tipc_nametbl_subscribe(sub);
 	else
 		tipc_conn_terminate(tn->topsrv, subscriber->conid);
-	spin_unlock_bh(&subscriber->lock);
 }
 
 /* Handle one request to establish a new subscriber */
-static void *subscr_named_msg_event(int conid)
+static void *tipc_subscrb_connect_cb(int conid)
 {
-	struct tipc_subscriber *subscriber;
-
-	/* Create subscriber object */
-	subscriber = kzalloc(sizeof(struct tipc_subscriber), GFP_ATOMIC);
-	if (subscriber == NULL) {
-		pr_warn("Subscriber rejected, no memory\n");
-		return NULL;
-	}
-	INIT_LIST_HEAD(&subscriber->subscription_list);
-	subscriber->conid = conid;
-	spin_lock_init(&subscriber->lock);
-
-	return (void *)subscriber;
+	return (void *)tipc_subscrb_create(conid);
 }
 
-int tipc_subscr_start(struct net *net)
+int tipc_topsrv_start(struct net *net)
 {
 	struct tipc_net *tn = net_generic(net, tipc_net_id);
 	const char name[] = "topology_server";
@@ -355,9 +333,9 @@ int tipc_subscr_start(struct net *net)
 	topsrv->imp			= TIPC_CRITICAL_IMPORTANCE;
 	topsrv->type			= SOCK_SEQPACKET;
 	topsrv->max_rcvbuf_size		= sizeof(struct tipc_subscr);
-	topsrv->tipc_conn_recvmsg	= subscr_conn_msg_event;
-	topsrv->tipc_conn_new		= subscr_named_msg_event;
-	topsrv->tipc_conn_shutdown	= subscr_conn_shutdown_event;
+	topsrv->tipc_conn_recvmsg	= tipc_subscrb_rcv_cb;
+	topsrv->tipc_conn_new		= tipc_subscrb_connect_cb;
+	topsrv->tipc_conn_shutdown	= tipc_subscrb_shutdown_cb;
 
 	strncpy(topsrv->name, name, strlen(name) + 1);
 	tn->topsrv = topsrv;
@@ -366,7 +344,7 @@ int tipc_subscr_start(struct net *net)
 	return tipc_server_start(topsrv);
 }
 
-void tipc_subscr_stop(struct net *net)
+void tipc_topsrv_stop(struct net *net)
 {
 	struct tipc_net *tn = net_generic(net, tipc_net_id);
 	struct tipc_server *topsrv = tn->topsrv;