RDS: TCP: Synchronize accept() and connect() paths on t_conn_lock.
[deliverable/linux.git] / net / rds / tcp_connect.c
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1/*
2 * Copyright (c) 2006 Oracle. All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses. You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:
9 *
10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted provided that the following
12 * conditions are met:
13 *
14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer.
17 *
18 * - Redistributions in binary form must reproduce the above
19 * copyright notice, this list of conditions and the following
20 * disclaimer in the documentation and/or other materials
21 * provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE.
31 *
32 */
33#include <linux/kernel.h>
34#include <linux/in.h>
35#include <net/tcp.h>
36
37#include "rds.h"
38#include "tcp.h"
39
40void rds_tcp_state_change(struct sock *sk)
41{
42 void (*state_change)(struct sock *sk);
43 struct rds_connection *conn;
44 struct rds_tcp_connection *tc;
45
bfdc587c 46 read_lock(&sk->sk_callback_lock);
70041088 47 conn = sk->sk_user_data;
8690bfa1 48 if (!conn) {
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49 state_change = sk->sk_state_change;
50 goto out;
51 }
52 tc = conn->c_transport_data;
53 state_change = tc->t_orig_state_change;
54
55 rdsdebug("sock %p state_change to %d\n", tc->t_sock, sk->sk_state);
56
57 switch(sk->sk_state) {
58 /* ignore connecting sockets as they make progress */
59 case TCP_SYN_SENT:
60 case TCP_SYN_RECV:
61 break;
62 case TCP_ESTABLISHED:
63 rds_connect_complete(conn);
64 break;
f711a6ae 65 case TCP_CLOSE_WAIT:
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66 case TCP_CLOSE:
67 rds_conn_drop(conn);
68 default:
69 break;
70 }
71out:
bfdc587c 72 read_unlock(&sk->sk_callback_lock);
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73 state_change(sk);
74}
75
76int rds_tcp_conn_connect(struct rds_connection *conn)
77{
78 struct socket *sock = NULL;
79 struct sockaddr_in src, dest;
80 int ret;
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81 struct rds_tcp_connection *tc = conn->c_transport_data;
82
83 mutex_lock(&tc->t_conn_lock);
70041088 84
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85 if (rds_conn_up(conn)) {
86 mutex_unlock(&tc->t_conn_lock);
87 return 0;
88 }
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89 ret = sock_create_kern(rds_conn_net(conn), PF_INET,
90 SOCK_STREAM, IPPROTO_TCP, &sock);
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91 if (ret < 0)
92 goto out;
93
94 rds_tcp_tune(sock);
95
96 src.sin_family = AF_INET;
97 src.sin_addr.s_addr = (__force u32)conn->c_laddr;
98 src.sin_port = (__force u16)htons(0);
99
100 ret = sock->ops->bind(sock, (struct sockaddr *)&src, sizeof(src));
101 if (ret) {
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102 rdsdebug("bind failed with %d at address %pI4\n",
103 ret, &conn->c_laddr);
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104 goto out;
105 }
106
107 dest.sin_family = AF_INET;
108 dest.sin_addr.s_addr = (__force u32)conn->c_faddr;
109 dest.sin_port = (__force u16)htons(RDS_TCP_PORT);
110
111 /*
112 * once we call connect() we can start getting callbacks and they
113 * own the socket
114 */
115 rds_tcp_set_callbacks(sock, conn);
116 ret = sock->ops->connect(sock, (struct sockaddr *)&dest, sizeof(dest),
117 O_NONBLOCK);
70041088 118
6884b348 119 rdsdebug("connect to address %pI4 returned %d\n", &conn->c_faddr, ret);
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120 if (ret == -EINPROGRESS)
121 ret = 0;
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122 if (ret == 0) {
123 rds_tcp_keepalive(sock);
eb74cc97 124 sock = NULL;
467fa153 125 } else {
eb74cc97 126 rds_tcp_restore_callbacks(sock, conn->c_transport_data);
467fa153 127 }
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128
129out:
bd7c5f98 130 mutex_unlock(&tc->t_conn_lock);
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131 if (sock)
132 sock_release(sock);
133 return ret;
134}
135
136/*
137 * Before killing the tcp socket this needs to serialize with callbacks. The
138 * caller has already grabbed the sending sem so we're serialized with other
139 * senders.
140 *
141 * TCP calls the callbacks with the sock lock so we hold it while we reset the
142 * callbacks to those set by TCP. Our callbacks won't execute again once we
143 * hold the sock lock.
144 */
145void rds_tcp_conn_shutdown(struct rds_connection *conn)
146{
147 struct rds_tcp_connection *tc = conn->c_transport_data;
148 struct socket *sock = tc->t_sock;
149
150 rdsdebug("shutting down conn %p tc %p sock %p\n", conn, tc, sock);
151
152 if (sock) {
153 sock->ops->shutdown(sock, RCV_SHUTDOWN | SEND_SHUTDOWN);
154 lock_sock(sock->sk);
155 rds_tcp_restore_callbacks(sock, tc); /* tc->tc_sock = NULL */
156
157 release_sock(sock->sk);
158 sock_release(sock);
ccbd6a5a 159 }
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160
161 if (tc->t_tinc) {
162 rds_inc_put(&tc->t_tinc->ti_inc);
163 tc->t_tinc = NULL;
164 }
165 tc->t_tinc_hdr_rem = sizeof(struct rds_header);
166 tc->t_tinc_data_rem = 0;
167}
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