rxrpc: Add a tracepoint to track rxrpc_local refcounting

Add a tracepoint to track reference counting on the rxrpc_local struct.

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

1 files changed, 63 insertions, 2 deletions

diff --git a/net/rxrpc/local_object.c b/net/rxrpc/local_object.c
index 38b99db30e54..8b54e9531d52 100644
--- a/net/rxrpc/local_object.c
+++ b/net/rxrpc/local_object.c
@@ -95,6 +95,7 @@ static struct rxrpc_local *rxrpc_alloc_local(struct rxrpc_net *rxnet,
 		local->debug_id = atomic_inc_return(&rxrpc_debug_id);
 		memcpy(&local->srx, srx, sizeof(*srx));
 		local->srx.srx_service = 0;
+		trace_rxrpc_local(local, rxrpc_local_new, 1, NULL);
 	}
 
 	_leave(" = %p", local);
@@ -257,15 +258,74 @@ addr_in_use:
 }
 
 /*
+ * Get a ref on a local endpoint.
+ */
+struct rxrpc_local *rxrpc_get_local(struct rxrpc_local *local)
+{
+	const void *here = __builtin_return_address(0);
+	int n;
+
+	n = atomic_inc_return(&local->usage);
+	trace_rxrpc_local(local, rxrpc_local_got, n, here);
+	return local;
+}
+
+/*
+ * Get a ref on a local endpoint unless its usage has already reached 0.
+ */
+struct rxrpc_local *rxrpc_get_local_maybe(struct rxrpc_local *local)
+{
+	const void *here = __builtin_return_address(0);
+
+	if (local) {
+		int n = __atomic_add_unless(&local->usage, 1, 0);
+		if (n > 0)
+			trace_rxrpc_local(local, rxrpc_local_got, n + 1, here);
+		else
+			local = NULL;
+	}
+	return local;
+}
+
+/*
+ * Queue a local endpoint.
+ */
+void rxrpc_queue_local(struct rxrpc_local *local)
+{
+	const void *here = __builtin_return_address(0);
+
+	if (rxrpc_queue_work(&local->processor))
+		trace_rxrpc_local(local, rxrpc_local_queued,
+				  atomic_read(&local->usage), here);
+}
+
+/*
  * A local endpoint reached its end of life.
  */
-void __rxrpc_put_local(struct rxrpc_local *local)
+static void __rxrpc_put_local(struct rxrpc_local *local)
 {
 	_enter("%d", local->debug_id);
 	rxrpc_queue_work(&local->processor);
 }
 
 /*
+ * Drop a ref on a local endpoint.
+ */
+void rxrpc_put_local(struct rxrpc_local *local)
+{
+	const void *here = __builtin_return_address(0);
+	int n;
+
+	if (local) {
+		n = atomic_dec_return(&local->usage);
+		trace_rxrpc_local(local, rxrpc_local_put, n, here);
+
+		if (n == 0)
+			__rxrpc_put_local(local);
+	}
+}
+
+/*
  * Destroy a local endpoint's socket and then hand the record to RCU to dispose
  * of.
  *
@@ -322,7 +382,8 @@ static void rxrpc_local_processor(struct work_struct *work)
 		container_of(work, struct rxrpc_local, processor);
 	bool again;
 
-	_enter("%d", local->debug_id);
+	trace_rxrpc_local(local, rxrpc_local_processing,
+			  atomic_read(&local->usage), NULL);
 
 	do {
 		again = false;