RDS: rds_send_xmit() locking/irq fixes
[linux-2.6.git] / net / rds / tcp.c
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/slab.h>
35 #include <linux/in.h>
36 #include <net/tcp.h>
37
38 #include "rds.h"
39 #include "tcp.h"
40
41 /* only for info exporting */
42 static DEFINE_SPINLOCK(rds_tcp_tc_list_lock);
43 static LIST_HEAD(rds_tcp_tc_list);
44 unsigned int rds_tcp_tc_count;
45
46 /* Track rds_tcp_connection structs so they can be cleaned up */
47 static DEFINE_SPINLOCK(rds_tcp_conn_lock);
48 static LIST_HEAD(rds_tcp_conn_list);
49
50 static struct kmem_cache *rds_tcp_conn_slab;
51
52 #define RDS_TCP_DEFAULT_BUFSIZE (128 * 1024)
53
54 /* doing it this way avoids calling tcp_sk() */
55 void rds_tcp_nonagle(struct socket *sock)
56 {
57         mm_segment_t oldfs = get_fs();
58         int val = 1;
59
60         set_fs(KERNEL_DS);
61         sock->ops->setsockopt(sock, SOL_TCP, TCP_NODELAY, (char __user *)&val,
62                               sizeof(val));
63         set_fs(oldfs);
64 }
65
66 void rds_tcp_tune(struct socket *sock)
67 {
68         struct sock *sk = sock->sk;
69
70         rds_tcp_nonagle(sock);
71
72         /*
73          * We're trying to saturate gigabit with the default,
74          * see svc_sock_setbufsize().
75          */
76         lock_sock(sk);
77         sk->sk_sndbuf = RDS_TCP_DEFAULT_BUFSIZE;
78         sk->sk_rcvbuf = RDS_TCP_DEFAULT_BUFSIZE;
79         sk->sk_userlocks |= SOCK_SNDBUF_LOCK|SOCK_RCVBUF_LOCK;
80         release_sock(sk);
81 }
82
83 u32 rds_tcp_snd_nxt(struct rds_tcp_connection *tc)
84 {
85         return tcp_sk(tc->t_sock->sk)->snd_nxt;
86 }
87
88 u32 rds_tcp_snd_una(struct rds_tcp_connection *tc)
89 {
90         return tcp_sk(tc->t_sock->sk)->snd_una;
91 }
92
93 void rds_tcp_restore_callbacks(struct socket *sock,
94                                struct rds_tcp_connection *tc)
95 {
96         rdsdebug("restoring sock %p callbacks from tc %p\n", sock, tc);
97         write_lock_bh(&sock->sk->sk_callback_lock);
98
99         /* done under the callback_lock to serialize with write_space */
100         spin_lock(&rds_tcp_tc_list_lock);
101         list_del_init(&tc->t_list_item);
102         rds_tcp_tc_count--;
103         spin_unlock(&rds_tcp_tc_list_lock);
104
105         tc->t_sock = NULL;
106
107         sock->sk->sk_write_space = tc->t_orig_write_space;
108         sock->sk->sk_data_ready = tc->t_orig_data_ready;
109         sock->sk->sk_state_change = tc->t_orig_state_change;
110         sock->sk->sk_user_data = NULL;
111
112         write_unlock_bh(&sock->sk->sk_callback_lock);
113 }
114
115 /*
116  * This is the only path that sets tc->t_sock.  Send and receive trust that
117  * it is set.  The RDS_CONN_CONNECTED bit protects those paths from being
118  * called while it isn't set.
119  */
120 void rds_tcp_set_callbacks(struct socket *sock, struct rds_connection *conn)
121 {
122         struct rds_tcp_connection *tc = conn->c_transport_data;
123
124         rdsdebug("setting sock %p callbacks to tc %p\n", sock, tc);
125         write_lock_bh(&sock->sk->sk_callback_lock);
126
127         /* done under the callback_lock to serialize with write_space */
128         spin_lock(&rds_tcp_tc_list_lock);
129         list_add_tail(&tc->t_list_item, &rds_tcp_tc_list);
130         rds_tcp_tc_count++;
131         spin_unlock(&rds_tcp_tc_list_lock);
132
133         /* accepted sockets need our listen data ready undone */
134         if (sock->sk->sk_data_ready == rds_tcp_listen_data_ready)
135                 sock->sk->sk_data_ready = sock->sk->sk_user_data;
136
137         tc->t_sock = sock;
138         tc->conn = conn;
139         tc->t_orig_data_ready = sock->sk->sk_data_ready;
140         tc->t_orig_write_space = sock->sk->sk_write_space;
141         tc->t_orig_state_change = sock->sk->sk_state_change;
142
143         sock->sk->sk_user_data = conn;
144         sock->sk->sk_data_ready = rds_tcp_data_ready;
145         sock->sk->sk_write_space = rds_tcp_write_space;
146         sock->sk->sk_state_change = rds_tcp_state_change;
147
148         write_unlock_bh(&sock->sk->sk_callback_lock);
149 }
150
151 static void rds_tcp_tc_info(struct socket *sock, unsigned int len,
152                             struct rds_info_iterator *iter,
153                             struct rds_info_lengths *lens)
154 {
155         struct rds_info_tcp_socket tsinfo;
156         struct rds_tcp_connection *tc;
157         unsigned long flags;
158         struct sockaddr_in sin;
159         int sinlen;
160
161         spin_lock_irqsave(&rds_tcp_tc_list_lock, flags);
162
163         if (len / sizeof(tsinfo) < rds_tcp_tc_count)
164                 goto out;
165
166         list_for_each_entry(tc, &rds_tcp_tc_list, t_list_item) {
167
168                 sock->ops->getname(sock, (struct sockaddr *)&sin, &sinlen, 0);
169                 tsinfo.local_addr = sin.sin_addr.s_addr;
170                 tsinfo.local_port = sin.sin_port;
171                 sock->ops->getname(sock, (struct sockaddr *)&sin, &sinlen, 1);
172                 tsinfo.peer_addr = sin.sin_addr.s_addr;
173                 tsinfo.peer_port = sin.sin_port;
174
175                 tsinfo.hdr_rem = tc->t_tinc_hdr_rem;
176                 tsinfo.data_rem = tc->t_tinc_data_rem;
177                 tsinfo.last_sent_nxt = tc->t_last_sent_nxt;
178                 tsinfo.last_expected_una = tc->t_last_expected_una;
179                 tsinfo.last_seen_una = tc->t_last_seen_una;
180
181                 rds_info_copy(iter, &tsinfo, sizeof(tsinfo));
182         }
183
184 out:
185         lens->nr = rds_tcp_tc_count;
186         lens->each = sizeof(tsinfo);
187
188         spin_unlock_irqrestore(&rds_tcp_tc_list_lock, flags);
189 }
190
191 static int rds_tcp_laddr_check(__be32 addr)
192 {
193         if (inet_addr_type(&init_net, addr) == RTN_LOCAL)
194                 return 0;
195         return -EADDRNOTAVAIL;
196 }
197
198 static int rds_tcp_conn_alloc(struct rds_connection *conn, gfp_t gfp)
199 {
200         struct rds_tcp_connection *tc;
201
202         tc = kmem_cache_alloc(rds_tcp_conn_slab, gfp);
203         if (!tc)
204                 return -ENOMEM;
205
206         tc->t_sock = NULL;
207         tc->t_tinc = NULL;
208         tc->t_tinc_hdr_rem = sizeof(struct rds_header);
209         tc->t_tinc_data_rem = 0;
210
211         conn->c_transport_data = tc;
212
213         spin_lock_irq(&rds_tcp_conn_lock);
214         list_add_tail(&tc->t_tcp_node, &rds_tcp_conn_list);
215         spin_unlock_irq(&rds_tcp_conn_lock);
216
217         rdsdebug("alloced tc %p\n", conn->c_transport_data);
218         return 0;
219 }
220
221 static void rds_tcp_conn_free(void *arg)
222 {
223         struct rds_tcp_connection *tc = arg;
224         rdsdebug("freeing tc %p\n", tc);
225         kmem_cache_free(rds_tcp_conn_slab, tc);
226 }
227
228 static void rds_tcp_destroy_conns(void)
229 {
230         struct rds_tcp_connection *tc, *_tc;
231         LIST_HEAD(tmp_list);
232
233         /* avoid calling conn_destroy with irqs off */
234         spin_lock_irq(&rds_tcp_conn_lock);
235         list_splice(&rds_tcp_conn_list, &tmp_list);
236         INIT_LIST_HEAD(&rds_tcp_conn_list);
237         spin_unlock_irq(&rds_tcp_conn_lock);
238
239         list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node) {
240                 if (tc->conn->c_passive)
241                         rds_conn_destroy(tc->conn->c_passive);
242                 rds_conn_destroy(tc->conn);
243         }
244 }
245
246 void rds_tcp_exit(void)
247 {
248         rds_info_deregister_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
249         rds_tcp_listen_stop();
250         rds_tcp_destroy_conns();
251         rds_trans_unregister(&rds_tcp_transport);
252         rds_tcp_recv_exit();
253         kmem_cache_destroy(rds_tcp_conn_slab);
254 }
255 module_exit(rds_tcp_exit);
256
257 struct rds_transport rds_tcp_transport = {
258         .laddr_check            = rds_tcp_laddr_check,
259         .xmit_prepare           = rds_tcp_xmit_prepare,
260         .xmit_complete          = rds_tcp_xmit_complete,
261         .xmit                   = rds_tcp_xmit,
262         .recv                   = rds_tcp_recv,
263         .conn_alloc             = rds_tcp_conn_alloc,
264         .conn_free              = rds_tcp_conn_free,
265         .conn_connect           = rds_tcp_conn_connect,
266         .conn_shutdown          = rds_tcp_conn_shutdown,
267         .inc_copy_to_user       = rds_tcp_inc_copy_to_user,
268         .inc_free               = rds_tcp_inc_free,
269         .stats_info_copy        = rds_tcp_stats_info_copy,
270         .exit                   = rds_tcp_exit,
271         .t_owner                = THIS_MODULE,
272         .t_name                 = "tcp",
273         .t_type                 = RDS_TRANS_TCP,
274         .t_prefer_loopback      = 1,
275 };
276
277 int __init rds_tcp_init(void)
278 {
279         int ret;
280
281         rds_tcp_conn_slab = kmem_cache_create("rds_tcp_connection",
282                                               sizeof(struct rds_tcp_connection),
283                                               0, 0, NULL);
284         if (!rds_tcp_conn_slab) {
285                 ret = -ENOMEM;
286                 goto out;
287         }
288
289         ret = rds_tcp_recv_init();
290         if (ret)
291                 goto out_slab;
292
293         ret = rds_trans_register(&rds_tcp_transport);
294         if (ret)
295                 goto out_recv;
296
297         ret = rds_tcp_listen_init();
298         if (ret)
299                 goto out_register;
300
301         rds_info_register_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
302
303         goto out;
304
305 out_register:
306         rds_trans_unregister(&rds_tcp_transport);
307 out_recv:
308         rds_tcp_recv_exit();
309 out_slab:
310         kmem_cache_destroy(rds_tcp_conn_slab);
311 out:
312         return ret;
313 }
314 module_init(rds_tcp_init);
315
316 MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
317 MODULE_DESCRIPTION("RDS: TCP transport");
318 MODULE_LICENSE("Dual BSD/GPL");
319