SUNRPC: Ensure we always close the socket after a connection shuts down

Ensure that we release the TCP socket once it is in the TCP_CLOSE or
TCP_TIME_WAIT state (and only then) so that we don't confuse rkhunter
and its ilk.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

net/sunrpc/xprtsock.c

@@ -807,13 +807,6 @@ static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
 	smp_mb__after_atomic();
 }
 
-static void xs_sock_mark_closed(struct rpc_xprt *xprt)
-{
-	xs_sock_reset_connection_flags(xprt);
-	/* Mark transport as closed and wake up all pending tasks */
-	xprt_disconnect_done(xprt);
-}
-
 /**
  * xs_error_report - callback to handle TCP socket state errors
  * @sk: socket
@@ -833,9 +826,6 @@ static void xs_error_report(struct sock *sk)
 	err = -sk->sk_err;
 	if (err == 0)
 		goto out;
-	/* Is this a reset event? */
-	if (sk->sk_state == TCP_CLOSE)
-		xs_sock_mark_closed(xprt);
 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
 			xprt, -err);
 	trace_rpc_socket_error(xprt, sk->sk_socket, err);
@@ -1655,9 +1645,11 @@ static void xs_tcp_state_change(struct sock *sk)
 		if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
 					&transport->sock_state))
 			xprt_clear_connecting(xprt);
+		clear_bit(XPRT_CLOSING, &xprt->state);
 		if (sk->sk_err)
 			xprt_wake_pending_tasks(xprt, -sk->sk_err);
-		xs_sock_mark_closed(xprt);
+		/* Trigger the socket release */
+		xs_tcp_force_close(xprt);
 	}
  out:
 	read_unlock_bh(&sk->sk_callback_lock);
@@ -2265,14 +2257,19 @@ static void xs_tcp_shutdown(struct rpc_xprt *xprt)
 {
 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 	struct socket *sock = transport->sock;
+	int skst = transport->inet ? transport->inet->sk_state : TCP_CLOSE;
 
 	if (sock == NULL)
 		return;
-	if (xprt_connected(xprt)) {
+	switch (skst) {
+	default:
 		kernel_sock_shutdown(sock, SHUT_RDWR);
 		trace_rpc_socket_shutdown(xprt, sock);
-	} else
+		break;
+	case TCP_CLOSE:
+	case TCP_TIME_WAIT:
 		xs_reset_transport(transport);
+	}
 }
 
 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,