Merge tag 'rxrpc-fixes-20171124' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

David Howells says:

====================
rxrpc: Fixes and improvements

Here's a set of patches that fix and improve some stuff in the AF_RXRPC
protocol:

The patches are:

 (1) Unlock mutex returned by rxrpc_accept_call().

 (2) Don't set connection upgrade by default.

 (3) Differentiate the call->user_mutex used by the kernel from that used
     by userspace calling sendmsg() to avoid lockdep warnings.

 (4) Delay terminal ACK transmission to a work queue so that it can be
     replaced by the next call if there is one.

 (5) Split the call parameters from the connection parameters so that more
     call-specific parameters can be passed through.

 (6) Fix the call timeouts to work the same as for other RxRPC/AFS
     implementations.

 (7) Don't transmit DELAY ACKs immediately, but instead delay them slightly
     so that can be discarded or can represent more packets.

 (8) Use RTT to calculate certain protocol timeouts.

 (9) Add a timeout to detect lost ACK/DATA packets.

(10) Add a keepalive function so that we ping the peer if we haven't
     transmitted for a short while, thereby keeping intervening firewall
     routes open.

(11) Make service endpoints expire like they're supposed to so that the UDP
     port can be reused.

(12) Fix connection expiry timers to make cleanup happen in a more timely
     fashion.
====================

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

1 files changed, 49 insertions, 27 deletions

diff --git a/net/rxrpc/conn_object.c b/net/rxrpc/conn_object.c
index fe575798592f..1aad04a32d5e 100644
--- a/net/rxrpc/conn_object.c
+++ b/net/rxrpc/conn_object.c
@@ -20,10 +20,19 @@
 /*
  * Time till a connection expires after last use (in seconds).
  */
-unsigned int rxrpc_connection_expiry = 10 * 60;
+unsigned int __read_mostly rxrpc_connection_expiry = 10 * 60;
+unsigned int __read_mostly rxrpc_closed_conn_expiry = 10;
 
 static void rxrpc_destroy_connection(struct rcu_head *);
 
+static void rxrpc_connection_timer(struct timer_list *timer)
+{
+	struct rxrpc_connection *conn =
+		container_of(timer, struct rxrpc_connection, timer);
+
+	rxrpc_queue_conn(conn);
+}
+
 /*
  * allocate a new connection
  */
@@ -38,6 +47,7 @@ struct rxrpc_connection *rxrpc_alloc_connection(gfp_t gfp)
 		INIT_LIST_HEAD(&conn->cache_link);
 		spin_lock_init(&conn->channel_lock);
 		INIT_LIST_HEAD(&conn->waiting_calls);
+		timer_setup(&conn->timer, &rxrpc_connection_timer, 0);
 		INIT_WORK(&conn->processor, &rxrpc_process_connection);
 		INIT_LIST_HEAD(&conn->proc_link);
 		INIT_LIST_HEAD(&conn->link);
@@ -301,21 +311,29 @@ rxrpc_get_connection_maybe(struct rxrpc_connection *conn)
 }
 
 /*
+ * Set the service connection reap timer.
+ */
+static void rxrpc_set_service_reap_timer(struct rxrpc_net *rxnet,
+					 unsigned long reap_at)
+{
+	if (rxnet->live)
+		timer_reduce(&rxnet->service_conn_reap_timer, reap_at);
+}
+
+/*
  * Release a service connection
  */
 void rxrpc_put_service_conn(struct rxrpc_connection *conn)
 {
-	struct rxrpc_net *rxnet;
 	const void *here = __builtin_return_address(0);
 	int n;
 
 	n = atomic_dec_return(&conn->usage);
 	trace_rxrpc_conn(conn, rxrpc_conn_put_service, n, here);
 	ASSERTCMP(n, >=, 0);
-	if (n == 0) {
-		rxnet = conn->params.local->rxnet;
-		rxrpc_queue_delayed_work(&rxnet->service_conn_reaper, 0);
-	}
+	if (n == 1)
+		rxrpc_set_service_reap_timer(conn->params.local->rxnet,
+					     jiffies + rxrpc_connection_expiry);
 }
 
 /*
@@ -332,6 +350,7 @@ static void rxrpc_destroy_connection(struct rcu_head *rcu)
 
 	_net("DESTROY CONN %d", conn->debug_id);
 
+	del_timer_sync(&conn->timer);
 	rxrpc_purge_queue(&conn->rx_queue);
 
 	conn->security->clear(conn);
@@ -351,17 +370,15 @@ void rxrpc_service_connection_reaper(struct work_struct *work)
 {
 	struct rxrpc_connection *conn, *_p;
 	struct rxrpc_net *rxnet =
-		container_of(to_delayed_work(work),
-			     struct rxrpc_net, service_conn_reaper);
-	unsigned long reap_older_than, earliest, idle_timestamp, now;
+		container_of(work, struct rxrpc_net, service_conn_reaper);
+	unsigned long expire_at, earliest, idle_timestamp, now;
 
 	LIST_HEAD(graveyard);
 
 	_enter("");
 
 	now = jiffies;
-	reap_older_than = now - rxrpc_connection_expiry * HZ;
-	earliest = ULONG_MAX;
+	earliest = now + MAX_JIFFY_OFFSET;
 
 	write_lock(&rxnet->conn_lock);
 	list_for_each_entry_safe(conn, _p, &rxnet->service_conns, link) {
@@ -371,15 +388,21 @@ void rxrpc_service_connection_reaper(struct work_struct *work)
 		if (conn->state == RXRPC_CONN_SERVICE_PREALLOC)
 			continue;
 
-		idle_timestamp = READ_ONCE(conn->idle_timestamp);
-		_debug("reap CONN %d { u=%d,t=%ld }",
-		       conn->debug_id, atomic_read(&conn->usage),
-		       (long)reap_older_than - (long)idle_timestamp);
-
-		if (time_after(idle_timestamp, reap_older_than)) {
-			if (time_before(idle_timestamp, earliest))
-				earliest = idle_timestamp;
-			continue;
+		if (rxnet->live) {
+			idle_timestamp = READ_ONCE(conn->idle_timestamp);
+			expire_at = idle_timestamp + rxrpc_connection_expiry * HZ;
+			if (conn->params.local->service_closed)
+				expire_at = idle_timestamp + rxrpc_closed_conn_expiry * HZ;
+
+			_debug("reap CONN %d { u=%d,t=%ld }",
+			       conn->debug_id, atomic_read(&conn->usage),
+			       (long)expire_at - (long)now);
+
+			if (time_before(now, expire_at)) {
+				if (time_before(expire_at, earliest))
+					earliest = expire_at;
+				continue;
+			}
 		}
 
 		/* The usage count sits at 1 whilst the object is unused on the
@@ -387,6 +410,7 @@ void rxrpc_service_connection_reaper(struct work_struct *work)
 		 */
 		if (atomic_cmpxchg(&conn->usage, 1, 0) != 1)
 			continue;
+		trace_rxrpc_conn(conn, rxrpc_conn_reap_service, 0, 0);
 
 		if (rxrpc_conn_is_client(conn))
 			BUG();
@@ -397,11 +421,10 @@ void rxrpc_service_connection_reaper(struct work_struct *work)
 	}
 	write_unlock(&rxnet->conn_lock);
 
-	if (earliest != ULONG_MAX) {
-		_debug("reschedule reaper %ld", (long) earliest - now);
+	if (earliest != now + MAX_JIFFY_OFFSET) {
+		_debug("reschedule reaper %ld", (long)earliest - (long)now);
 		ASSERT(time_after(earliest, now));
-		rxrpc_queue_delayed_work(&rxnet->client_conn_reaper,
-					 earliest - now);
+		rxrpc_set_service_reap_timer(rxnet, earliest);		
 	}
 
 	while (!list_empty(&graveyard)) {
@@ -429,9 +452,8 @@ void rxrpc_destroy_all_connections(struct rxrpc_net *rxnet)
 
 	rxrpc_destroy_all_client_connections(rxnet);
 
-	rxrpc_connection_expiry = 0;
-	cancel_delayed_work(&rxnet->client_conn_reaper);
-	rxrpc_queue_delayed_work(&rxnet->client_conn_reaper, 0);
+	del_timer_sync(&rxnet->service_conn_reap_timer);
+	rxrpc_queue_work(&rxnet->service_conn_reaper);
 	flush_workqueue(rxrpc_workqueue);
 
 	write_lock(&rxnet->conn_lock);