Commit f0043206 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

SUNRPC: Ensure we flush any closed sockets before xs_xprt_free() 



We must ensure that all sockets are closed before we call xprt_free()
and release the reference to the net namespace. The problem is that
calling fput() will defer closing the socket until delayed_fput() gets
called.
Let's fix the situation by allowing rpciod and the transport teardown
code (which runs on the system wq) to call __fput_sync(), and directly
close the socket.

Reported-by: default avatarFelix Fu <foyjog@gmail.com>
Acked-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Fixes: a73881c9 ("SUNRPC: Fix an Oops in udp_poll()")
Cc: stable@vger.kernel.org # 5.1.x: 3be232f1: SUNRPC: Prevent immediate close+reconnect
Cc: stable@vger.kernel.org # 5.1.x: 89f42494: SUNRPC: Don't call connect() more than once on a TCP socket
Cc: stable@vger.kernel.org # 5.1.x
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent 830f1111

fs/file_table.c

+1 −0
Original line number Diff line number Diff line
@@ -412,6 +412,7 @@ void __fput_sync(struct file *file) 
}



EXPORT_SYMBOL(fput);

EXPORT_SYMBOL(__fput_sync);



void __init files_init(void)

{

include/trace/events/sunrpc.h

+0 −1
Original line number Diff line number Diff line
@@ -1004,7 +1004,6 @@ DEFINE_RPC_XPRT_LIFETIME_EVENT(connect); 
DEFINE_RPC_XPRT_LIFETIME_EVENT(disconnect_auto);

DEFINE_RPC_XPRT_LIFETIME_EVENT(disconnect_done);

DEFINE_RPC_XPRT_LIFETIME_EVENT(disconnect_force);

DEFINE_RPC_XPRT_LIFETIME_EVENT(disconnect_cleanup);

DEFINE_RPC_XPRT_LIFETIME_EVENT(destroy);



DECLARE_EVENT_CLASS(rpc_xprt_event,

net/sunrpc/xprt.c

+1 −6
Original line number Diff line number Diff line
@@ -930,12 +930,7 @@ void xprt_connect(struct rpc_task *task) 
	if (!xprt_lock_write(xprt, task))

		return;



	if (test_and_clear_bit(XPRT_CLOSE_WAIT, &xprt->state)) {

		trace_xprt_disconnect_cleanup(xprt);

		xprt->ops->close(xprt);

	}



	if (!xprt_connected(xprt)) {

	if (!xprt_connected(xprt) && !test_bit(XPRT_CLOSE_WAIT, &xprt->state)) {

		task->tk_rqstp->rq_connect_cookie = xprt->connect_cookie;

		rpc_sleep_on_timeout(&xprt->pending, task, NULL,

				xprt_request_timeout(task->tk_rqstp));

net/sunrpc/xprtsock.c

+13 −3
Original line number Diff line number Diff line
@@ -879,7 +879,7 @@ static int xs_local_send_request(struct rpc_rqst *req) 


	/* Close the stream if the previous transmission was incomplete */

	if (xs_send_request_was_aborted(transport, req)) {

		xs_close(xprt);

		xprt_force_disconnect(xprt);

		return -ENOTCONN;

	}
@@ -915,7 +915,7 @@ static int xs_local_send_request(struct rpc_rqst *req) 
			-status);

		fallthrough;

	case -EPIPE:

		xs_close(xprt);

		xprt_force_disconnect(xprt);

		status = -ENOTCONN;

	}
@@ -1185,6 +1185,16 @@ static void xs_reset_transport(struct sock_xprt *transport) 


	if (sk == NULL)

		return;

	/*

	 * Make sure we're calling this in a context from which it is safe

	 * to call __fput_sync(). In practice that means rpciod and the

	 * system workqueue.

	 */

	if (!(current->flags & PF_WQ_WORKER)) {

		WARN_ON_ONCE(1);

		set_bit(XPRT_CLOSE_WAIT, &xprt->state);

		return;

	}



	if (atomic_read(&transport->xprt.swapper))

		sk_clear_memalloc(sk);
@@ -1208,7 +1218,7 @@ static void xs_reset_transport(struct sock_xprt *transport) 
	mutex_unlock(&transport->recv_mutex);



	trace_rpc_socket_close(xprt, sock);

	fput(filp);

	__fput_sync(filp);



	xprt_disconnect_done(xprt);

}