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Commit 4dda9c8a authored by Trond Myklebust's avatar Trond Myklebust
Browse files

SUNRPC: Set SO_REUSEPORT socket option for TCP connections 



When using TCP, we need the ability to reuse port numbers after
a disconnection, so that the NFSv3 server knows that we're the same
client. Currently we use a hack to work around the TCP socket's
TIME_WAIT: we send an RST instead of closing, which doesn't
always work...
The SO_REUSEPORT option added in Linux 3.9 allows us to bind multiple
TCP connections to the same source address+port combination, and thus
to use ordinary TCP close() instead of the current hack.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
parent bc3203cd

net/sunrpc/xprtsock.c

+49 −4
Original line number Diff line number Diff line
@@ -1666,6 +1666,39 @@ static unsigned short xs_get_random_port(void) 
	return rand + xprt_min_resvport;

}



/**

 * xs_set_reuseaddr_port - set the socket's port and address reuse options

 * @sock: socket

 *

 * Note that this function has to be called on all sockets that share the

 * same port, and it must be called before binding.

 */

static void xs_sock_set_reuseport(struct socket *sock)

{

	char opt = 1;



	kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEPORT, &opt, sizeof(opt));

}



static unsigned short xs_sock_getport(struct socket *sock)

{

	struct sockaddr_storage buf;

	int buflen;

	unsigned short port = 0;



	if (kernel_getsockname(sock, (struct sockaddr *)&buf, &buflen) < 0)

		goto out;

	switch (buf.ss_family) {

	case AF_INET6:

		port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);

		break;

	case AF_INET:

		port = ntohs(((struct sockaddr_in *)&buf)->sin_port);

	}

out:

	return port;

}



/**

 * xs_set_port - reset the port number in the remote endpoint address

 * @xprt: generic transport
@@ -1680,6 +1713,12 @@ static void xs_set_port(struct rpc_xprt *xprt, unsigned short port) 
	xs_update_peer_port(xprt);

}



static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)

{

	if (transport->srcport == 0)

		transport->srcport = xs_sock_getport(sock);

}



static unsigned short xs_get_srcport(struct sock_xprt *transport)

{

	unsigned short port = transport->srcport;
@@ -1833,7 +1872,8 @@ static void xs_dummy_setup_socket(struct work_struct *work) 
}



static struct socket *xs_create_sock(struct rpc_xprt *xprt,

		struct sock_xprt *transport, int family, int type, int protocol)

		struct sock_xprt *transport, int family, int type,

		int protocol, bool reuseport)

{

	struct socket *sock;

	int err;
@@ -1846,6 +1886,9 @@ static struct socket *xs_create_sock(struct rpc_xprt *xprt, 
	}

	xs_reclassify_socket(family, sock);



	if (reuseport)

		xs_sock_set_reuseport(sock);



	err = xs_bind(transport, sock);

	if (err) {

		sock_release(sock);
@@ -2047,7 +2090,8 @@ static void xs_udp_setup_socket(struct work_struct *work) 
	/* Start by resetting any existing state */

	xs_reset_transport(transport);

	sock = xs_create_sock(xprt, transport,

			xs_addr(xprt)->sa_family, SOCK_DGRAM, IPPROTO_UDP);

			xs_addr(xprt)->sa_family, SOCK_DGRAM,

			IPPROTO_UDP, false);

	if (IS_ERR(sock))

		goto out;
@@ -2149,7 +2193,6 @@ static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock) 
		sk->sk_allocation = GFP_ATOMIC;



		/* socket options */

		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;

		sock_reset_flag(sk, SOCK_LINGER);

		tcp_sk(sk)->linger2 = 0;

		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
@@ -2174,6 +2217,7 @@ static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock) 
	ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);

	switch (ret) {

	case 0:

		xs_set_srcport(transport, sock);

	case -EINPROGRESS:

		/* SYN_SENT! */

		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
@@ -2202,7 +2246,8 @@ static void xs_tcp_setup_socket(struct work_struct *work) 
	if (!sock) {

		clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);

		sock = xs_create_sock(xprt, transport,

				xs_addr(xprt)->sa_family, SOCK_STREAM, IPPROTO_TCP);

				xs_addr(xprt)->sa_family, SOCK_STREAM,

				IPPROTO_TCP, true);

		if (IS_ERR(sock)) {

			status = PTR_ERR(sock);

			goto out;