3bb549ae4c
The state of the rds_connection after rds_tcp_reset_callbacks() would be RDS_CONN_RESETTING and this is the value that should be passed by rds_tcp_accept_one() to rds_connect_path_complete() to transition the socket to RDS_CONN_UP. Fixes: b5c21c0947c1 ("RDS: TCP: fix race windows in send-path quiescence by rds_tcp_accept_one()") Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
249 lines
6.7 KiB
C
249 lines
6.7 KiB
C
/*
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* Copyright (c) 2006 Oracle. All rights reserved.
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*
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* This software is available to you under a choice of one of two
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* licenses. You may choose to be licensed under the terms of the GNU
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* General Public License (GPL) Version 2, available from the file
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* COPYING in the main directory of this source tree, or the
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* OpenIB.org BSD license below:
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*
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* Redistribution and use in source and binary forms, with or
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* without modification, are permitted provided that the following
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* conditions are met:
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*
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* - Redistributions of source code must retain the above
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* copyright notice, this list of conditions and the following
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* disclaimer.
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*
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* - Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following
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* disclaimer in the documentation and/or other materials
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* provided with the distribution.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/gfp.h>
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#include <linux/in.h>
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#include <net/tcp.h>
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#include "rds.h"
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#include "tcp.h"
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int rds_tcp_keepalive(struct socket *sock)
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{
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/* values below based on xs_udp_default_timeout */
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int keepidle = 5; /* send a probe 'keepidle' secs after last data */
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int keepcnt = 5; /* number of unack'ed probes before declaring dead */
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int keepalive = 1;
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int ret = 0;
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ret = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
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(char *)&keepalive, sizeof(keepalive));
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if (ret < 0)
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goto bail;
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ret = kernel_setsockopt(sock, IPPROTO_TCP, TCP_KEEPCNT,
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(char *)&keepcnt, sizeof(keepcnt));
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if (ret < 0)
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goto bail;
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ret = kernel_setsockopt(sock, IPPROTO_TCP, TCP_KEEPIDLE,
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(char *)&keepidle, sizeof(keepidle));
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if (ret < 0)
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goto bail;
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/* KEEPINTVL is the interval between successive probes. We follow
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* the model in xs_tcp_finish_connecting() and re-use keepidle.
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*/
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ret = kernel_setsockopt(sock, IPPROTO_TCP, TCP_KEEPINTVL,
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(char *)&keepidle, sizeof(keepidle));
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bail:
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return ret;
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}
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int rds_tcp_accept_one(struct socket *sock)
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{
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struct socket *new_sock = NULL;
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struct rds_connection *conn;
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int ret;
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struct inet_sock *inet;
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struct rds_tcp_connection *rs_tcp = NULL;
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int conn_state;
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if (!sock) /* module unload or netns delete in progress */
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return -ENETUNREACH;
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ret = sock_create_kern(sock_net(sock->sk), sock->sk->sk_family,
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sock->sk->sk_type, sock->sk->sk_protocol,
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&new_sock);
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if (ret)
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goto out;
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new_sock->type = sock->type;
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new_sock->ops = sock->ops;
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ret = sock->ops->accept(sock, new_sock, O_NONBLOCK);
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if (ret < 0)
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goto out;
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ret = rds_tcp_keepalive(new_sock);
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if (ret < 0)
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goto out;
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rds_tcp_tune(new_sock);
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inet = inet_sk(new_sock->sk);
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rdsdebug("accepted tcp %pI4:%u -> %pI4:%u\n",
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&inet->inet_saddr, ntohs(inet->inet_sport),
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&inet->inet_daddr, ntohs(inet->inet_dport));
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conn = rds_conn_create(sock_net(sock->sk),
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inet->inet_saddr, inet->inet_daddr,
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&rds_tcp_transport, GFP_KERNEL);
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if (IS_ERR(conn)) {
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ret = PTR_ERR(conn);
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goto out;
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}
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/* An incoming SYN request came in, and TCP just accepted it.
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*
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* If the client reboots, this conn will need to be cleaned up.
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* rds_tcp_state_change() will do that cleanup
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*/
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rs_tcp = (struct rds_tcp_connection *)conn->c_transport_data;
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rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_CONNECTING);
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mutex_lock(&rs_tcp->t_conn_lock);
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conn_state = rds_conn_state(conn);
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if (conn_state != RDS_CONN_CONNECTING && conn_state != RDS_CONN_UP)
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goto rst_nsk;
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if (rs_tcp->t_sock) {
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/* Need to resolve a duelling SYN between peers.
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* We have an outstanding SYN to this peer, which may
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* potentially have transitioned to the RDS_CONN_UP state,
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* so we must quiesce any send threads before resetting
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* c_transport_data.
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*/
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if (ntohl(inet->inet_saddr) < ntohl(inet->inet_daddr) ||
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!conn->c_outgoing) {
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goto rst_nsk;
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} else {
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rds_tcp_reset_callbacks(new_sock, conn);
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conn->c_outgoing = 0;
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/* rds_connect_path_complete() marks RDS_CONN_UP */
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rds_connect_path_complete(conn, RDS_CONN_RESETTING);
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}
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} else {
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rds_tcp_set_callbacks(new_sock, conn);
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rds_connect_path_complete(conn, RDS_CONN_CONNECTING);
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}
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new_sock = NULL;
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ret = 0;
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goto out;
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rst_nsk:
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/* reset the newly returned accept sock and bail */
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kernel_sock_shutdown(new_sock, SHUT_RDWR);
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ret = 0;
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out:
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if (rs_tcp)
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mutex_unlock(&rs_tcp->t_conn_lock);
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if (new_sock)
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sock_release(new_sock);
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return ret;
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}
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void rds_tcp_listen_data_ready(struct sock *sk)
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{
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void (*ready)(struct sock *sk);
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rdsdebug("listen data ready sk %p\n", sk);
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read_lock_bh(&sk->sk_callback_lock);
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ready = sk->sk_user_data;
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if (!ready) { /* check for teardown race */
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ready = sk->sk_data_ready;
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goto out;
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}
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/*
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* ->sk_data_ready is also called for a newly established child socket
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* before it has been accepted and the accepter has set up their
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* data_ready.. we only want to queue listen work for our listening
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* socket
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*/
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if (sk->sk_state == TCP_LISTEN)
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rds_tcp_accept_work(sk);
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out:
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read_unlock_bh(&sk->sk_callback_lock);
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ready(sk);
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}
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struct socket *rds_tcp_listen_init(struct net *net)
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{
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struct sockaddr_in sin;
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struct socket *sock = NULL;
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int ret;
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ret = sock_create_kern(net, PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
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if (ret < 0)
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goto out;
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sock->sk->sk_reuse = SK_CAN_REUSE;
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rds_tcp_nonagle(sock);
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write_lock_bh(&sock->sk->sk_callback_lock);
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sock->sk->sk_user_data = sock->sk->sk_data_ready;
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sock->sk->sk_data_ready = rds_tcp_listen_data_ready;
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write_unlock_bh(&sock->sk->sk_callback_lock);
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sin.sin_family = PF_INET;
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sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
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sin.sin_port = (__force u16)htons(RDS_TCP_PORT);
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ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
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if (ret < 0)
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goto out;
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ret = sock->ops->listen(sock, 64);
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if (ret < 0)
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goto out;
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return sock;
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out:
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if (sock)
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sock_release(sock);
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return NULL;
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}
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void rds_tcp_listen_stop(struct socket *sock)
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{
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struct sock *sk;
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if (!sock)
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return;
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sk = sock->sk;
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/* serialize with and prevent further callbacks */
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lock_sock(sk);
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write_lock_bh(&sk->sk_callback_lock);
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if (sk->sk_user_data) {
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sk->sk_data_ready = sk->sk_user_data;
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sk->sk_user_data = NULL;
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}
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write_unlock_bh(&sk->sk_callback_lock);
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release_sock(sk);
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/* wait for accepts to stop and close the socket */
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flush_workqueue(rds_wq);
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sock_release(sock);
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}
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