rxrpc: Add connection tracepoint and client conn state tracepoint

Add a pair of tracepoints, one to track rxrpc_connection struct ref
counting and the other to track the client connection cache state.

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

net/rxrpc/call_accept.c

@@ -85,6 +85,9 @@ static int rxrpc_service_prealloc_one(struct rxrpc_sock *rx,
 		b->conn_backlog[head] = conn;
 		smp_store_release(&b->conn_backlog_head,
 				  (head + 1) & (size - 1));
+
+		trace_rxrpc_conn(conn, rxrpc_conn_new_service,
+				 atomic_read(&conn->usage), here);
 	}
 
 	/* Now it gets complicated, because calls get registered with the
@@ -290,6 +293,7 @@ static struct rxrpc_call *rxrpc_alloc_incoming_call(struct rxrpc_sock *rx,
 		rxrpc_get_local(local);
 		conn->params.local = local;
 		conn->params.peer = peer;
+		rxrpc_see_connection(conn);
 		rxrpc_new_incoming_connection(conn, skb);
 	} else {
 		rxrpc_get_connection(conn);