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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/list.h> | |
35 | #include <net/inet_hashtables.h> | |
36 | ||
37 | #include "rds.h" | |
38 | #include "loop.h" | |
39 | #include "rdma.h" | |
40 | ||
41 | #define RDS_CONNECTION_HASH_BITS 12 | |
42 | #define RDS_CONNECTION_HASH_ENTRIES (1 << RDS_CONNECTION_HASH_BITS) | |
43 | #define RDS_CONNECTION_HASH_MASK (RDS_CONNECTION_HASH_ENTRIES - 1) | |
44 | ||
45 | /* converting this to RCU is a chore for another day.. */ | |
46 | static DEFINE_SPINLOCK(rds_conn_lock); | |
47 | static unsigned long rds_conn_count; | |
48 | static struct hlist_head rds_conn_hash[RDS_CONNECTION_HASH_ENTRIES]; | |
49 | static struct kmem_cache *rds_conn_slab; | |
50 | ||
51 | static struct hlist_head *rds_conn_bucket(__be32 laddr, __be32 faddr) | |
52 | { | |
53 | /* Pass NULL, don't need struct net for hash */ | |
54 | unsigned long hash = inet_ehashfn(NULL, | |
55 | be32_to_cpu(laddr), 0, | |
56 | be32_to_cpu(faddr), 0); | |
57 | return &rds_conn_hash[hash & RDS_CONNECTION_HASH_MASK]; | |
58 | } | |
59 | ||
60 | #define rds_conn_info_set(var, test, suffix) do { \ | |
61 | if (test) \ | |
62 | var |= RDS_INFO_CONNECTION_FLAG_##suffix; \ | |
63 | } while (0) | |
64 | ||
65 | static inline int rds_conn_is_sending(struct rds_connection *conn) | |
66 | { | |
67 | int ret = 0; | |
68 | ||
69 | if (!mutex_trylock(&conn->c_send_lock)) | |
70 | ret = 1; | |
71 | else | |
72 | mutex_unlock(&conn->c_send_lock); | |
73 | ||
74 | return ret; | |
75 | } | |
76 | ||
77 | static struct rds_connection *rds_conn_lookup(struct hlist_head *head, | |
78 | __be32 laddr, __be32 faddr, | |
79 | struct rds_transport *trans) | |
80 | { | |
81 | struct rds_connection *conn, *ret = NULL; | |
82 | struct hlist_node *pos; | |
83 | ||
84 | hlist_for_each_entry(conn, pos, head, c_hash_node) { | |
85 | if (conn->c_faddr == faddr && conn->c_laddr == laddr && | |
86 | conn->c_trans == trans) { | |
87 | ret = conn; | |
88 | break; | |
89 | } | |
90 | } | |
91 | rdsdebug("returning conn %p for %pI4 -> %pI4\n", ret, | |
92 | &laddr, &faddr); | |
93 | return ret; | |
94 | } | |
95 | ||
96 | /* | |
97 | * This is called by transports as they're bringing down a connection. | |
98 | * It clears partial message state so that the transport can start sending | |
99 | * and receiving over this connection again in the future. It is up to | |
100 | * the transport to have serialized this call with its send and recv. | |
101 | */ | |
102 | void rds_conn_reset(struct rds_connection *conn) | |
103 | { | |
104 | rdsdebug("connection %pI4 to %pI4 reset\n", | |
105 | &conn->c_laddr, &conn->c_faddr); | |
106 | ||
107 | rds_stats_inc(s_conn_reset); | |
108 | rds_send_reset(conn); | |
109 | conn->c_flags = 0; | |
110 | ||
111 | /* Do not clear next_rx_seq here, else we cannot distinguish | |
112 | * retransmitted packets from new packets, and will hand all | |
113 | * of them to the application. That is not consistent with the | |
114 | * reliability guarantees of RDS. */ | |
115 | } | |
116 | ||
117 | /* | |
118 | * There is only every one 'conn' for a given pair of addresses in the | |
119 | * system at a time. They contain messages to be retransmitted and so | |
120 | * span the lifetime of the actual underlying transport connections. | |
121 | * | |
122 | * For now they are not garbage collected once they're created. They | |
123 | * are torn down as the module is removed, if ever. | |
124 | */ | |
125 | static struct rds_connection *__rds_conn_create(__be32 laddr, __be32 faddr, | |
126 | struct rds_transport *trans, gfp_t gfp, | |
127 | int is_outgoing) | |
128 | { | |
129 | struct rds_connection *conn, *tmp, *parent = NULL; | |
130 | struct hlist_head *head = rds_conn_bucket(laddr, faddr); | |
131 | unsigned long flags; | |
132 | int ret; | |
133 | ||
134 | spin_lock_irqsave(&rds_conn_lock, flags); | |
135 | conn = rds_conn_lookup(head, laddr, faddr, trans); | |
136 | if (conn | |
137 | && conn->c_loopback | |
138 | && conn->c_trans != &rds_loop_transport | |
139 | && !is_outgoing) { | |
140 | /* This is a looped back IB connection, and we're | |
141 | * called by the code handling the incoming connect. | |
142 | * We need a second connection object into which we | |
143 | * can stick the other QP. */ | |
144 | parent = conn; | |
145 | conn = parent->c_passive; | |
146 | } | |
147 | spin_unlock_irqrestore(&rds_conn_lock, flags); | |
148 | if (conn) | |
149 | goto out; | |
150 | ||
151 | conn = kmem_cache_alloc(rds_conn_slab, gfp); | |
152 | if (conn == NULL) { | |
153 | conn = ERR_PTR(-ENOMEM); | |
154 | goto out; | |
155 | } | |
156 | ||
157 | memset(conn, 0, sizeof(*conn)); | |
158 | ||
159 | INIT_HLIST_NODE(&conn->c_hash_node); | |
160 | conn->c_version = RDS_PROTOCOL_3_0; | |
161 | conn->c_laddr = laddr; | |
162 | conn->c_faddr = faddr; | |
163 | spin_lock_init(&conn->c_lock); | |
164 | conn->c_next_tx_seq = 1; | |
165 | ||
166 | mutex_init(&conn->c_send_lock); | |
167 | INIT_LIST_HEAD(&conn->c_send_queue); | |
168 | INIT_LIST_HEAD(&conn->c_retrans); | |
169 | ||
170 | ret = rds_cong_get_maps(conn); | |
171 | if (ret) { | |
172 | kmem_cache_free(rds_conn_slab, conn); | |
173 | conn = ERR_PTR(ret); | |
174 | goto out; | |
175 | } | |
176 | ||
177 | /* | |
178 | * This is where a connection becomes loopback. If *any* RDS sockets | |
179 | * can bind to the destination address then we'd rather the messages | |
180 | * flow through loopback rather than either transport. | |
181 | */ | |
182 | if (rds_trans_get_preferred(faddr)) { | |
183 | conn->c_loopback = 1; | |
184 | if (is_outgoing && trans->t_prefer_loopback) { | |
185 | /* "outgoing" connection - and the transport | |
186 | * says it wants the connection handled by the | |
187 | * loopback transport. This is what TCP does. | |
188 | */ | |
189 | trans = &rds_loop_transport; | |
190 | } | |
191 | } | |
192 | ||
193 | conn->c_trans = trans; | |
194 | ||
195 | ret = trans->conn_alloc(conn, gfp); | |
196 | if (ret) { | |
197 | kmem_cache_free(rds_conn_slab, conn); | |
198 | conn = ERR_PTR(ret); | |
199 | goto out; | |
200 | } | |
201 | ||
202 | atomic_set(&conn->c_state, RDS_CONN_DOWN); | |
203 | conn->c_reconnect_jiffies = 0; | |
204 | INIT_DELAYED_WORK(&conn->c_send_w, rds_send_worker); | |
205 | INIT_DELAYED_WORK(&conn->c_recv_w, rds_recv_worker); | |
206 | INIT_DELAYED_WORK(&conn->c_conn_w, rds_connect_worker); | |
207 | INIT_WORK(&conn->c_down_w, rds_shutdown_worker); | |
208 | mutex_init(&conn->c_cm_lock); | |
209 | conn->c_flags = 0; | |
210 | ||
211 | rdsdebug("allocated conn %p for %pI4 -> %pI4 over %s %s\n", | |
212 | conn, &laddr, &faddr, | |
213 | trans->t_name ? trans->t_name : "[unknown]", | |
214 | is_outgoing ? "(outgoing)" : ""); | |
215 | ||
216 | spin_lock_irqsave(&rds_conn_lock, flags); | |
217 | if (parent == NULL) { | |
218 | tmp = rds_conn_lookup(head, laddr, faddr, trans); | |
219 | if (tmp == NULL) | |
220 | hlist_add_head(&conn->c_hash_node, head); | |
221 | } else { | |
222 | tmp = parent->c_passive; | |
223 | if (!tmp) | |
224 | parent->c_passive = conn; | |
225 | } | |
226 | ||
227 | if (tmp) { | |
228 | trans->conn_free(conn->c_transport_data); | |
229 | kmem_cache_free(rds_conn_slab, conn); | |
230 | conn = tmp; | |
231 | } else { | |
232 | rds_cong_add_conn(conn); | |
233 | rds_conn_count++; | |
234 | } | |
235 | ||
236 | spin_unlock_irqrestore(&rds_conn_lock, flags); | |
237 | ||
238 | out: | |
239 | return conn; | |
240 | } | |
241 | ||
242 | struct rds_connection *rds_conn_create(__be32 laddr, __be32 faddr, | |
243 | struct rds_transport *trans, gfp_t gfp) | |
244 | { | |
245 | return __rds_conn_create(laddr, faddr, trans, gfp, 0); | |
246 | } | |
247 | ||
248 | struct rds_connection *rds_conn_create_outgoing(__be32 laddr, __be32 faddr, | |
249 | struct rds_transport *trans, gfp_t gfp) | |
250 | { | |
251 | return __rds_conn_create(laddr, faddr, trans, gfp, 1); | |
252 | } | |
253 | ||
254 | void rds_conn_destroy(struct rds_connection *conn) | |
255 | { | |
256 | struct rds_message *rm, *rtmp; | |
257 | ||
258 | rdsdebug("freeing conn %p for %pI4 -> " | |
259 | "%pI4\n", conn, &conn->c_laddr, | |
260 | &conn->c_faddr); | |
261 | ||
262 | hlist_del_init(&conn->c_hash_node); | |
263 | ||
264 | /* wait for the rds thread to shut it down */ | |
265 | atomic_set(&conn->c_state, RDS_CONN_ERROR); | |
266 | cancel_delayed_work(&conn->c_conn_w); | |
267 | queue_work(rds_wq, &conn->c_down_w); | |
268 | flush_workqueue(rds_wq); | |
269 | ||
270 | /* tear down queued messages */ | |
271 | list_for_each_entry_safe(rm, rtmp, | |
272 | &conn->c_send_queue, | |
273 | m_conn_item) { | |
274 | list_del_init(&rm->m_conn_item); | |
275 | BUG_ON(!list_empty(&rm->m_sock_item)); | |
276 | rds_message_put(rm); | |
277 | } | |
278 | if (conn->c_xmit_rm) | |
279 | rds_message_put(conn->c_xmit_rm); | |
280 | ||
281 | conn->c_trans->conn_free(conn->c_transport_data); | |
282 | ||
283 | /* | |
284 | * The congestion maps aren't freed up here. They're | |
285 | * freed by rds_cong_exit() after all the connections | |
286 | * have been freed. | |
287 | */ | |
288 | rds_cong_remove_conn(conn); | |
289 | ||
290 | BUG_ON(!list_empty(&conn->c_retrans)); | |
291 | kmem_cache_free(rds_conn_slab, conn); | |
292 | ||
293 | rds_conn_count--; | |
294 | } | |
295 | ||
296 | static void rds_conn_message_info(struct socket *sock, unsigned int len, | |
297 | struct rds_info_iterator *iter, | |
298 | struct rds_info_lengths *lens, | |
299 | int want_send) | |
300 | { | |
301 | struct hlist_head *head; | |
302 | struct hlist_node *pos; | |
303 | struct list_head *list; | |
304 | struct rds_connection *conn; | |
305 | struct rds_message *rm; | |
306 | unsigned long flags; | |
307 | unsigned int total = 0; | |
308 | size_t i; | |
309 | ||
310 | len /= sizeof(struct rds_info_message); | |
311 | ||
312 | spin_lock_irqsave(&rds_conn_lock, flags); | |
313 | ||
314 | for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash); | |
315 | i++, head++) { | |
316 | hlist_for_each_entry(conn, pos, head, c_hash_node) { | |
317 | if (want_send) | |
318 | list = &conn->c_send_queue; | |
319 | else | |
320 | list = &conn->c_retrans; | |
321 | ||
322 | spin_lock(&conn->c_lock); | |
323 | ||
324 | /* XXX too lazy to maintain counts.. */ | |
325 | list_for_each_entry(rm, list, m_conn_item) { | |
326 | total++; | |
327 | if (total <= len) | |
328 | rds_inc_info_copy(&rm->m_inc, iter, | |
329 | conn->c_laddr, | |
330 | conn->c_faddr, 0); | |
331 | } | |
332 | ||
333 | spin_unlock(&conn->c_lock); | |
334 | } | |
335 | } | |
336 | ||
337 | spin_unlock_irqrestore(&rds_conn_lock, flags); | |
338 | ||
339 | lens->nr = total; | |
340 | lens->each = sizeof(struct rds_info_message); | |
341 | } | |
342 | ||
343 | static void rds_conn_message_info_send(struct socket *sock, unsigned int len, | |
344 | struct rds_info_iterator *iter, | |
345 | struct rds_info_lengths *lens) | |
346 | { | |
347 | rds_conn_message_info(sock, len, iter, lens, 1); | |
348 | } | |
349 | ||
350 | static void rds_conn_message_info_retrans(struct socket *sock, | |
351 | unsigned int len, | |
352 | struct rds_info_iterator *iter, | |
353 | struct rds_info_lengths *lens) | |
354 | { | |
355 | rds_conn_message_info(sock, len, iter, lens, 0); | |
356 | } | |
357 | ||
358 | void rds_for_each_conn_info(struct socket *sock, unsigned int len, | |
359 | struct rds_info_iterator *iter, | |
360 | struct rds_info_lengths *lens, | |
361 | int (*visitor)(struct rds_connection *, void *), | |
362 | size_t item_len) | |
363 | { | |
364 | uint64_t buffer[(item_len + 7) / 8]; | |
365 | struct hlist_head *head; | |
366 | struct hlist_node *pos; | |
367 | struct hlist_node *tmp; | |
368 | struct rds_connection *conn; | |
369 | unsigned long flags; | |
370 | size_t i; | |
371 | ||
372 | spin_lock_irqsave(&rds_conn_lock, flags); | |
373 | ||
374 | lens->nr = 0; | |
375 | lens->each = item_len; | |
376 | ||
377 | for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash); | |
378 | i++, head++) { | |
379 | hlist_for_each_entry_safe(conn, pos, tmp, head, c_hash_node) { | |
380 | ||
381 | /* XXX no c_lock usage.. */ | |
382 | if (!visitor(conn, buffer)) | |
383 | continue; | |
384 | ||
385 | /* We copy as much as we can fit in the buffer, | |
386 | * but we count all items so that the caller | |
387 | * can resize the buffer. */ | |
388 | if (len >= item_len) { | |
389 | rds_info_copy(iter, buffer, item_len); | |
390 | len -= item_len; | |
391 | } | |
392 | lens->nr++; | |
393 | } | |
394 | } | |
395 | ||
396 | spin_unlock_irqrestore(&rds_conn_lock, flags); | |
397 | } | |
398 | ||
399 | static int rds_conn_info_visitor(struct rds_connection *conn, | |
400 | void *buffer) | |
401 | { | |
402 | struct rds_info_connection *cinfo = buffer; | |
403 | ||
404 | cinfo->next_tx_seq = conn->c_next_tx_seq; | |
405 | cinfo->next_rx_seq = conn->c_next_rx_seq; | |
406 | cinfo->laddr = conn->c_laddr; | |
407 | cinfo->faddr = conn->c_faddr; | |
408 | strncpy(cinfo->transport, conn->c_trans->t_name, | |
409 | sizeof(cinfo->transport)); | |
410 | cinfo->flags = 0; | |
411 | ||
412 | rds_conn_info_set(cinfo->flags, | |
413 | rds_conn_is_sending(conn), SENDING); | |
414 | /* XXX Future: return the state rather than these funky bits */ | |
415 | rds_conn_info_set(cinfo->flags, | |
416 | atomic_read(&conn->c_state) == RDS_CONN_CONNECTING, | |
417 | CONNECTING); | |
418 | rds_conn_info_set(cinfo->flags, | |
419 | atomic_read(&conn->c_state) == RDS_CONN_UP, | |
420 | CONNECTED); | |
421 | return 1; | |
422 | } | |
423 | ||
424 | static void rds_conn_info(struct socket *sock, unsigned int len, | |
425 | struct rds_info_iterator *iter, | |
426 | struct rds_info_lengths *lens) | |
427 | { | |
428 | rds_for_each_conn_info(sock, len, iter, lens, | |
429 | rds_conn_info_visitor, | |
430 | sizeof(struct rds_info_connection)); | |
431 | } | |
432 | ||
433 | int __init rds_conn_init(void) | |
434 | { | |
435 | rds_conn_slab = kmem_cache_create("rds_connection", | |
436 | sizeof(struct rds_connection), | |
437 | 0, 0, NULL); | |
438 | if (rds_conn_slab == NULL) | |
439 | return -ENOMEM; | |
440 | ||
441 | rds_info_register_func(RDS_INFO_CONNECTIONS, rds_conn_info); | |
442 | rds_info_register_func(RDS_INFO_SEND_MESSAGES, | |
443 | rds_conn_message_info_send); | |
444 | rds_info_register_func(RDS_INFO_RETRANS_MESSAGES, | |
445 | rds_conn_message_info_retrans); | |
446 | ||
447 | return 0; | |
448 | } | |
449 | ||
450 | void rds_conn_exit(void) | |
451 | { | |
452 | rds_loop_exit(); | |
453 | ||
454 | WARN_ON(!hlist_empty(rds_conn_hash)); | |
455 | ||
456 | kmem_cache_destroy(rds_conn_slab); | |
457 | ||
458 | rds_info_deregister_func(RDS_INFO_CONNECTIONS, rds_conn_info); | |
459 | rds_info_deregister_func(RDS_INFO_SEND_MESSAGES, | |
460 | rds_conn_message_info_send); | |
461 | rds_info_deregister_func(RDS_INFO_RETRANS_MESSAGES, | |
462 | rds_conn_message_info_retrans); | |
463 | } | |
464 | ||
465 | /* | |
466 | * Force a disconnect | |
467 | */ | |
468 | void rds_conn_drop(struct rds_connection *conn) | |
469 | { | |
470 | atomic_set(&conn->c_state, RDS_CONN_ERROR); | |
471 | queue_work(rds_wq, &conn->c_down_w); | |
472 | } | |
473 | ||
474 | /* | |
475 | * An error occurred on the connection | |
476 | */ | |
477 | void | |
478 | __rds_conn_error(struct rds_connection *conn, const char *fmt, ...) | |
479 | { | |
480 | va_list ap; | |
481 | ||
482 | va_start(ap, fmt); | |
483 | vprintk(fmt, ap); | |
484 | va_end(ap); | |
485 | ||
486 | rds_conn_drop(conn); | |
487 | } |