Commit 89f42494 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

SUNRPC: Don't call connect() more than once on a TCP socket 



Avoid socket state races due to repeated calls to ->connect() using the
same socket. If connect() returns 0 due to the connection having
completed, but we are in fact in a closing state, then we may leave the
XPRT_CONNECTING flag set on the transport.

Reported-by: default avatarEnrico Scholz <enrico.scholz@sigma-chemnitz.de>
Fixes: 3be232f1 ("SUNRPC: Prevent immediate close+reconnect")
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent e47a62df

include/linux/sunrpc/xprtsock.h

+1 −0
Original line number Diff line number Diff line
@@ -89,5 +89,6 @@ struct sock_xprt { 
#define XPRT_SOCK_WAKE_WRITE	(5)

#define XPRT_SOCK_WAKE_PENDING	(6)

#define XPRT_SOCK_WAKE_DISCONNECT	(7)

#define XPRT_SOCK_CONNECT_SENT	(8)



#endif /* _LINUX_SUNRPC_XPRTSOCK_H */

net/sunrpc/xprtsock.c

+12 −10
Original line number Diff line number Diff line
@@ -2235,10 +2235,15 @@ static void xs_tcp_setup_socket(struct work_struct *work) 


	if (atomic_read(&xprt->swapper))

		current->flags |= PF_MEMALLOC;

	if (!sock) {

		sock = xs_create_sock(xprt, transport,

				xs_addr(xprt)->sa_family, SOCK_STREAM,

				IPPROTO_TCP, true);



	if (xprt_connected(xprt))

		goto out;

	if (test_and_clear_bit(XPRT_SOCK_CONNECT_SENT,

			       &transport->sock_state) ||

	    !sock) {

		xs_reset_transport(transport);

		sock = xs_create_sock(xprt, transport, xs_addr(xprt)->sa_family,

				      SOCK_STREAM, IPPROTO_TCP, true);

		if (IS_ERR(sock)) {

			xprt_wake_pending_tasks(xprt, PTR_ERR(sock));

			goto out;
@@ -2262,6 +2267,7 @@ static void xs_tcp_setup_socket(struct work_struct *work) 
		fallthrough;

	case -EINPROGRESS:

		/* SYN_SENT! */

		set_bit(XPRT_SOCK_CONNECT_SENT, &transport->sock_state);

		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)

			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;

		fallthrough;
@@ -2323,13 +2329,9 @@ static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task) 


	WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));



	if (transport->sock != NULL && !xprt_connecting(xprt)) {

	if (transport->sock != NULL) {

		dprintk("RPC:       xs_connect delayed xprt %p for %lu "

				"seconds\n",

				xprt, xprt->reestablish_timeout / HZ);



		/* Start by resetting any existing state */

		xs_reset_transport(transport);

			"seconds\n", xprt, xprt->reestablish_timeout / HZ);



		delay = xprt_reconnect_delay(xprt);

		xprt_reconnect_backoff(xprt, XS_TCP_INIT_REEST_TO);