rxrpc: Fix conn expiry timers

Fix the rxrpc connection expiry timers so that connections for closed
AF_RXRPC sockets get deleted in a more timely fashion, freeing up the
transport UDP port much more quickly.

 (1) Replace the delayed work items with work items plus timers so that
     timer_reduce() can be used to shorten them and so that the timer
     doesn't requeue the work item if the net namespace is dead.

 (2) Don't use queue_delayed_work() as that won't alter the timeout if the
     timer is already running.

 (3) Don't rearm the timers if the network namespace is dead.

Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 17 insertions, 11 deletions

diff --git a/net/rxrpc/conn_object.c b/net/rxrpc/conn_object.c
index 726eda6140ae..1aad04a32d5e 100644
--- a/net/rxrpc/conn_object.c
+++ b/net/rxrpc/conn_object.c
@@ -311,21 +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 == 1) {
-		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);
 }
 
 /*
@@ -362,8 +370,7 @@ 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);
+		container_of(work, struct rxrpc_net, service_conn_reaper);
 	unsigned long expire_at, earliest, idle_timestamp, now;
 
 	LIST_HEAD(graveyard);
@@ -417,8 +424,7 @@ void rxrpc_service_connection_reaper(struct work_struct *work)
 	if (earliest != now + MAX_JIFFY_OFFSET) {
 		_debug("reschedule reaper %ld", (long)earliest - (long)now);
 		ASSERT(time_after(earliest, now));
-		rxrpc_queue_delayed_work(&rxnet->service_conn_reaper,
-					 earliest - now);
+		rxrpc_set_service_reap_timer(rxnet, earliest);		
 	}
 
 	while (!list_empty(&graveyard)) {
@@ -446,8 +452,8 @@ void rxrpc_destroy_all_connections(struct rxrpc_net *rxnet)
 
 	rxrpc_destroy_all_client_connections(rxnet);
 
-	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);