Merge branch 'tipc'

Paul Gortmaker says:

====================
This is a rework of the content sent earlier[1], with the following changes:

	-drop the Kconfig --> modparam conversion patch; this was
	 requested to be replaced[2] with a dynamic port quantity resizing.
	 Ying and Erik were discussing how best to achieve this, and then
	 vacation schedules got in the way, so implementing that will
	 come (hopefully) in the next round.

	-rework the sk_rcvbuf patch to allow memory resizing via sysctl
	 as per what Ying and Neil discussed[3]

	-add 4 more seemingly straigtforward and relatively small changes
	 from Ying (the last 4 in the series).

	-add cosmetic UAPI comment update patch from Ying.

That said, the largest change is still the one where we make use of
the fact that linux supports kernel threads and do the server like
operations within kernel threads.  As Jon says:

   We remove the last remnants of the TIPC native API, to make it
   possible to simplify locking policy and solve a problem with lost
   topology events.

   First, we introduce a socket-based alternative to the native API.

   Second, we convert the two remaining users of the native API, the
   TIPC internal topology server and the configuarion server, to use the
   new API.

   Third, we remove the remaining code pertaining to the native API.

I have re-tested this collection of commits between 32 and 64 bit x86
machines using the standard tipc test suite, and build tested for ppc.

[1] http://patchwork.ozlabs.org/patch/247687/
[2] http://patchwork.ozlabs.org/patch/247680/
[3] http://patchwork.ozlabs.org/patch/247688/
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 97 insertions, 251 deletions

diff --git a/net/tipc/subscr.c b/net/tipc/subscr.c
index 6b42d47029a..d38bb45d82e 100644
--- a/net/tipc/subscr.c
+++ b/net/tipc/subscr.c
@@ -2,7 +2,7 @@
  * net/tipc/subscr.c: TIPC network topology service
  *
  * Copyright (c) 2000-2006, Ericsson AB
- * Copyright (c) 2005-2007, 2010-2011, Wind River Systems
+ * Copyright (c) 2005-2007, 2010-2013, Wind River Systems
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -41,33 +41,42 @@
 
 /**
  * struct tipc_subscriber - TIPC network topology subscriber
- * @port_ref: object reference to server port connecting to subscriber
- * @lock: pointer to spinlock controlling access to subscriber's server port
- * @subscriber_list: adjacent subscribers in top. server's list of subscribers
+ * @conid: connection identifier to server connecting to subscriber
+ * @lock: controll access to subscriber
  * @subscription_list: list of subscription objects for this subscriber
  */
 struct tipc_subscriber {
-	u32 port_ref;
-	spinlock_t *lock;
-	struct list_head subscriber_list;
+	int conid;
+	spinlock_t lock;
 	struct list_head subscription_list;
 };
 
-/**
- * struct top_srv - TIPC network topology subscription service
- * @setup_port: reference to TIPC port that handles subscription requests
- * @subscription_count: number of active subscriptions (not subscribers!)
- * @subscriber_list: list of ports subscribing to service
- * @lock: spinlock govering access to subscriber list
- */
-struct top_srv {
-	u32 setup_port;
-	atomic_t subscription_count;
-	struct list_head subscriber_list;
-	spinlock_t lock;
+static void subscr_conn_msg_event(int conid, struct sockaddr_tipc *addr,
+				  void *usr_data, void *buf, size_t len);
+static void *subscr_named_msg_event(int conid);
+static void subscr_conn_shutdown_event(int conid, void *usr_data);
+
+static atomic_t subscription_count = ATOMIC_INIT(0);
+
+static struct sockaddr_tipc topsrv_addr __read_mostly = {
+	.family			= AF_TIPC,
+	.addrtype		= TIPC_ADDR_NAMESEQ,
+	.addr.nameseq.type	= TIPC_TOP_SRV,
+	.addr.nameseq.lower	= TIPC_TOP_SRV,
+	.addr.nameseq.upper	= TIPC_TOP_SRV,
+	.scope			= TIPC_NODE_SCOPE
 };
 
-static struct top_srv topsrv;
+static struct tipc_server topsrv __read_mostly = {
+	.saddr			= &topsrv_addr,
+	.imp			= TIPC_CRITICAL_IMPORTANCE,
+	.type			= SOCK_SEQPACKET,
+	.max_rcvbuf_size	= sizeof(struct tipc_subscr),
+	.name			= "topology_server",
+	.tipc_conn_recvmsg	= subscr_conn_msg_event,
+	.tipc_conn_new		= subscr_named_msg_event,
+	.tipc_conn_shutdown	= subscr_conn_shutdown_event,
+};
 
 /**
  * htohl - convert value to endianness used by destination
@@ -81,20 +90,13 @@ static u32 htohl(u32 in, int swap)
 	return swap ? swab32(in) : in;
 }
 
-/**
- * subscr_send_event - send a message containing a tipc_event to the subscriber
- *
- * Note: Must not hold subscriber's server port lock, since tipc_send() will
- *       try to take the lock if the message is rejected and returned!
- */
-static void subscr_send_event(struct tipc_subscription *sub,
-			      u32 found_lower,
-			      u32 found_upper,
-			      u32 event,
-			      u32 port_ref,
+static void subscr_send_event(struct tipc_subscription *sub, u32 found_lower,
+			      u32 found_upper, u32 event, u32 port_ref,
 			      u32 node)
 {
-	struct iovec msg_sect;
+	struct tipc_subscriber *subscriber = sub->subscriber;
+	struct kvec msg_sect;
+	int ret;
 
 	msg_sect.iov_base = (void *)&sub->evt;
 	msg_sect.iov_len = sizeof(struct tipc_event);
@@ -104,7 +106,10 @@ static void subscr_send_event(struct tipc_subscription *sub,
 	sub->evt.found_upper = htohl(found_upper, sub->swap);
 	sub->evt.port.ref = htohl(port_ref, sub->swap);
 	sub->evt.port.node = htohl(node, sub->swap);
-	tipc_send(sub->server_ref, 1, &msg_sect, msg_sect.iov_len);
+	ret = tipc_conn_sendmsg(&topsrv, subscriber->conid, NULL,
+				msg_sect.iov_base, msg_sect.iov_len);
+	if (ret < 0)
+		pr_err("Sending subscription event failed, no memory\n");
 }
 
 /**
@@ -112,10 +117,8 @@ static void subscr_send_event(struct tipc_subscription *sub,
  *
  * Returns 1 if there is overlap, otherwise 0.
  */
-int tipc_subscr_overlap(struct tipc_subscription *sub,
-			u32 found_lower,
+int tipc_subscr_overlap(struct tipc_subscription *sub, u32 found_lower,
 			u32 found_upper)
-
 {
 	if (found_lower < sub->seq.lower)
 		found_lower = sub->seq.lower;
@@ -131,13 +134,9 @@ int tipc_subscr_overlap(struct tipc_subscription *sub,
  *
  * 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_subscr_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))
 		return;
@@ -147,21 +146,24 @@ void tipc_subscr_report_overlap(struct tipc_subscription *sub,
 	subscr_send_event(sub, found_lower, found_upper, event, port_ref, node);
 }
 
-/**
- * subscr_timeout - subscription timeout has occurred
- */
 static void subscr_timeout(struct tipc_subscription *sub)
 {
-	struct tipc_port *server_port;
+	struct tipc_subscriber *subscriber = sub->subscriber;
+
+	/* The spin lock per subscriber is used to protect its members */
+	spin_lock_bh(&subscriber->lock);
 
-	/* Validate server port reference (in case subscriber is terminating) */
-	server_port = tipc_port_lock(sub->server_ref);
-	if (server_port == NULL)
+	/* Validate if the connection related to the subscriber is
+	 * closed (in case subscriber is terminating)
+	 */
+	if (subscriber->conid == 0) {
+		spin_unlock_bh(&subscriber->lock);
 		return;
+	}
 
 	/* Validate timeout (in case subscription is being cancelled) */
 	if (sub->timeout == TIPC_WAIT_FOREVER) {
-		tipc_port_unlock(server_port);
+		spin_unlock_bh(&subscriber->lock);
 		return;
 	}
 
@@ -171,8 +173,7 @@ static void subscr_timeout(struct tipc_subscription *sub)
 	/* Unlink subscription from subscriber */
 	list_del(&sub->subscription_list);
 
-	/* Release subscriber's server port */
-	tipc_port_unlock(server_port);
+	spin_unlock_bh(&subscriber->lock);
 
 	/* Notify subscriber of timeout */
 	subscr_send_event(sub, sub->evt.s.seq.lower, sub->evt.s.seq.upper,
@@ -181,64 +182,54 @@ static void subscr_timeout(struct tipc_subscription *sub)
 	/* Now destroy subscription */
 	k_term_timer(&sub->timer);
 	kfree(sub);
-	atomic_dec(&topsrv.subscription_count);
+	atomic_dec(&subscription_count);
 }
 
 /**
  * subscr_del - delete a subscription within a subscription list
  *
- * Called with subscriber port locked.
+ * Called with subscriber lock held.
  */
 static void subscr_del(struct tipc_subscription *sub)
 {
 	tipc_nametbl_unsubscribe(sub);
 	list_del(&sub->subscription_list);
 	kfree(sub);
-	atomic_dec(&topsrv.subscription_count);
+	atomic_dec(&subscription_count);
 }
 
 /**
  * subscr_terminate - terminate communication with a subscriber
  *
- * Called with subscriber port locked.  Routine must temporarily release lock
- * to enable subscription timeout routine(s) to finish without deadlocking;
- * the lock is then reclaimed to allow caller to release it upon return.
- * (This should work even in the unlikely event some other thread creates
- * a new object reference in the interim that uses this lock; this routine will
- * simply wait for it to be released, then claim it.)
+ * Note: Must call it in process context since it might sleep.
  */
 static void subscr_terminate(struct tipc_subscriber *subscriber)
 {
-	u32 port_ref;
+	tipc_conn_terminate(&topsrv, subscriber->conid);
+}
+
+static void subscr_release(struct tipc_subscriber *subscriber)
+{
 	struct tipc_subscription *sub;
 	struct tipc_subscription *sub_temp;
 
-	/* Invalidate subscriber reference */
-	port_ref = subscriber->port_ref;
-	subscriber->port_ref = 0;
-	spin_unlock_bh(subscriber->lock);
+	spin_lock_bh(&subscriber->lock);
 
-	/* Sever connection to subscriber */
-	tipc_shutdown(port_ref);
-	tipc_deleteport(port_ref);
+	/* Invalidate subscriber reference */
+	subscriber->conid = 0;
 
 	/* 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);
 			k_cancel_timer(&sub->timer);
 			k_term_timer(&sub->timer);
+			spin_lock_bh(&subscriber->lock);
 		}
 		subscr_del(sub);
 	}
-
-	/* Remove subscriber from topology server's subscriber list */
-	spin_lock_bh(&topsrv.lock);
-	list_del(&subscriber->subscriber_list);
-	spin_unlock_bh(&topsrv.lock);
-
-	/* Reclaim subscriber lock */
-	spin_lock_bh(subscriber->lock);
+	spin_unlock_bh(&subscriber->lock);
 
 	/* Now destroy subscriber */
 	kfree(subscriber);
@@ -247,7 +238,7 @@ static void subscr_terminate(struct tipc_subscriber *subscriber)
 /**
  * subscr_cancel - handle subscription cancellation request
  *
- * Called with subscriber port locked.  Routine must temporarily release lock
+ * 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.
  *
@@ -274,10 +265,10 @@ static void subscr_cancel(struct tipc_subscr *s,
 	/* Cancel subscription timer (if used), then delete subscription */
 	if (sub->timeout != TIPC_WAIT_FOREVER) {
 		sub->timeout = TIPC_WAIT_FOREVER;
-		spin_unlock_bh(subscriber->lock);
+		spin_unlock_bh(&subscriber->lock);
 		k_cancel_timer(&sub->timer);
 		k_term_timer(&sub->timer);
-		spin_lock_bh(subscriber->lock);
+		spin_lock_bh(&subscriber->lock);
 	}
 	subscr_del(sub);
 }
@@ -285,7 +276,7 @@ static void subscr_cancel(struct tipc_subscr *s,
 /**
  * subscr_subscribe - create subscription for subscriber
  *
- * Called with subscriber port locked.
+ * Called with subscriber lock held.
  */
 static struct tipc_subscription *subscr_subscribe(struct tipc_subscr *s,
 					     struct tipc_subscriber *subscriber)
@@ -304,7 +295,7 @@ static struct tipc_subscription *subscr_subscribe(struct tipc_subscr *s,
 	}
 
 	/* Refuse subscription if global limit exceeded */
-	if (atomic_read(&topsrv.subscription_count) >= TIPC_MAX_SUBSCRIPTIONS) {
+	if (atomic_read(&subscription_count) >= TIPC_MAX_SUBSCRIPTIONS) {
 		pr_warn("Subscription rejected, limit reached (%u)\n",
 			TIPC_MAX_SUBSCRIPTIONS);
 		subscr_terminate(subscriber);
@@ -335,10 +326,10 @@ static struct tipc_subscription *subscr_subscribe(struct tipc_subscr *s,
 	}
 	INIT_LIST_HEAD(&sub->nameseq_list);
 	list_add(&sub->subscription_list, &subscriber->subscription_list);
-	sub->server_ref = subscriber->port_ref;
+	sub->subscriber = subscriber;
 	sub->swap = swap;
 	memcpy(&sub->evt.s, s, sizeof(struct tipc_subscr));
-	atomic_inc(&topsrv.subscription_count);
+	atomic_inc(&subscription_count);
 	if (sub->timeout != TIPC_WAIT_FOREVER) {
 		k_init_timer(&sub->timer,
 			     (Handler)subscr_timeout, (unsigned long)sub);
@@ -348,196 +339,51 @@ static struct tipc_subscription *subscr_subscribe(struct tipc_subscr *s,
 	return sub;
 }
 
-/**
- * subscr_conn_shutdown_event - handle termination request from subscriber
- *
- * Called with subscriber's server port unlocked.
- */
-static void subscr_conn_shutdown_event(void *usr_handle,
-				       u32 port_ref,
-				       struct sk_buff **buf,
-				       unsigned char const *data,
-				       unsigned int size,
-				       int reason)
+/* Handle one termination request for the subscriber */
+static void subscr_conn_shutdown_event(int conid, void *usr_data)
 {
-	struct tipc_subscriber *subscriber = usr_handle;
-	spinlock_t *subscriber_lock;
-
-	if (tipc_port_lock(port_ref) == NULL)
-		return;
-
-	subscriber_lock = subscriber->lock;
-	subscr_terminate(subscriber);
-	spin_unlock_bh(subscriber_lock);
+	subscr_release((struct tipc_subscriber *)usr_data);
 }
 
-/**
- * subscr_conn_msg_event - handle new subscription request from subscriber
- *
- * Called with subscriber's server port unlocked.
- */
-static void subscr_conn_msg_event(void *usr_handle,
-				  u32 port_ref,
-				  struct sk_buff **buf,
-				  const unchar *data,
-				  u32 size)
+/* Handle one request to create a new subscription for the subscriber */
+static void subscr_conn_msg_event(int conid, struct sockaddr_tipc *addr,
+				  void *usr_data, void *buf, size_t len)
 {
-	struct tipc_subscriber *subscriber = usr_handle;
-	spinlock_t *subscriber_lock;
+	struct tipc_subscriber *subscriber = usr_data;
 	struct tipc_subscription *sub;
 
-	/*
-	 * Lock subscriber's server port (& make a local copy of lock pointer,
-	 * in case subscriber is deleted while processing subscription request)
-	 */
-	if (tipc_port_lock(port_ref) == NULL)
-		return;
-
-	subscriber_lock = subscriber->lock;
-
-	if (size != sizeof(struct tipc_subscr)) {
-		subscr_terminate(subscriber);
-		spin_unlock_bh(subscriber_lock);
-	} else {
-		sub = subscr_subscribe((struct tipc_subscr *)data, subscriber);
-		spin_unlock_bh(subscriber_lock);
-		if (sub != NULL) {
-
-			/*
-			 * We must release the server port lock before adding a
-			 * subscription to the name table since TIPC needs to be
-			 * able to (re)acquire the port lock if an event message
-			 * issued by the subscription process is rejected and
-			 * returned.  The subscription cannot be deleted while
-			 * it is being added to the name table because:
-			 * a) the single-threading of the native API port code
-			 *    ensures the subscription cannot be cancelled and
-			 *    the subscriber connection cannot be broken, and
-			 * b) the name table lock ensures the subscription
-			 *    timeout code cannot delete the subscription,
-			 * so the subscription object is still protected.
-			 */
-			tipc_nametbl_subscribe(sub);
-		}
-	}
+	spin_lock_bh(&subscriber->lock);
+	sub = subscr_subscribe((struct tipc_subscr *)buf, subscriber);
+	if (sub)
+		tipc_nametbl_subscribe(sub);
+	spin_unlock_bh(&subscriber->lock);
 }
 
-/**
- * subscr_named_msg_event - handle request to establish a new subscriber
- */
-static void subscr_named_msg_event(void *usr_handle,
-				   u32 port_ref,
-				   struct sk_buff **buf,
-				   const unchar *data,
-				   u32 size,
-				   u32 importance,
-				   struct tipc_portid const *orig,
-				   struct tipc_name_seq const *dest)
+
+/* Handle one request to establish a new subscriber */
+static void *subscr_named_msg_event(int conid)
 {
 	struct tipc_subscriber *subscriber;
-	u32 server_port_ref;
 
 	/* Create subscriber object */
 	subscriber = kzalloc(sizeof(struct tipc_subscriber), GFP_ATOMIC);
 	if (subscriber == NULL) {
 		pr_warn("Subscriber rejected, no memory\n");
-		return;
+		return NULL;
 	}
 	INIT_LIST_HEAD(&subscriber->subscription_list);
-	INIT_LIST_HEAD(&subscriber->subscriber_list);
-
-	/* Create server port & establish connection to subscriber */
-	tipc_createport(subscriber,
-			importance,
-			NULL,
-			NULL,
-			subscr_conn_shutdown_event,
-			NULL,
-			NULL,
-			subscr_conn_msg_event,
-			NULL,
-			&subscriber->port_ref);
-	if (subscriber->port_ref == 0) {
-		pr_warn("Subscriber rejected, unable to create port\n");
-		kfree(subscriber);
-		return;
-	}
-	tipc_connect(subscriber->port_ref, orig);
-
-	/* Lock server port (& save lock address for future use) */
-	subscriber->lock = tipc_port_lock(subscriber->port_ref)->lock;
-
-	/* Add subscriber to topology server's subscriber list */
-	spin_lock_bh(&topsrv.lock);
-	list_add(&subscriber->subscriber_list, &topsrv.subscriber_list);
-	spin_unlock_bh(&topsrv.lock);
-
-	/* Unlock server port */
-	server_port_ref = subscriber->port_ref;
-	spin_unlock_bh(subscriber->lock);
-
-	/* Send an ACK- to complete connection handshaking */
-	tipc_send(server_port_ref, 0, NULL, 0);
+	subscriber->conid = conid;
+	spin_lock_init(&subscriber->lock);
 
-	/* Handle optional subscription request */
-	if (size != 0) {
-		subscr_conn_msg_event(subscriber, server_port_ref,
-				      buf, data, size);
-	}
+	return (void *)subscriber;
 }
 
 int tipc_subscr_start(void)
 {
-	struct tipc_name_seq seq = {TIPC_TOP_SRV, TIPC_TOP_SRV, TIPC_TOP_SRV};
-	int res;
-
-	spin_lock_init(&topsrv.lock);
-	INIT_LIST_HEAD(&topsrv.subscriber_list);
-
-	res = tipc_createport(NULL,
-			      TIPC_CRITICAL_IMPORTANCE,
-			      NULL,
-			      NULL,
-			      NULL,
-			      NULL,
-			      subscr_named_msg_event,
-			      NULL,
-			      NULL,
-			      &topsrv.setup_port);
-	if (res)
-		goto failed;
-
-	res = tipc_publish(topsrv.setup_port, TIPC_NODE_SCOPE, &seq);
-	if (res) {
-		tipc_deleteport(topsrv.setup_port);
-		topsrv.setup_port = 0;
-		goto failed;
-	}
-
-	return 0;
-
-failed:
-	pr_err("Failed to create subscription service\n");
-	return res;
+	return tipc_server_start(&topsrv);
 }
 
 void tipc_subscr_stop(void)
 {
-	struct tipc_subscriber *subscriber;
-	struct tipc_subscriber *subscriber_temp;
-	spinlock_t *subscriber_lock;
-
-	if (topsrv.setup_port) {
-		tipc_deleteport(topsrv.setup_port);
-		topsrv.setup_port = 0;
-
-		list_for_each_entry_safe(subscriber, subscriber_temp,
-					 &topsrv.subscriber_list,
-					 subscriber_list) {
-			subscriber_lock = subscriber->lock;
-			spin_lock_bh(subscriber_lock);
-			subscr_terminate(subscriber);
-			spin_unlock_bh(subscriber_lock);
-		}
-	}
+	tipc_server_stop(&topsrv);
 }