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33#include <linux/kernel.h>
34#include <linux/list.h>
35#include <linux/slab.h>
36#include <linux/export.h>
37#include <net/inet_hashtables.h>
38
39#include "rds.h"
40#include "loop.h"
41
42#define RDS_CONNECTION_HASH_BITS 12
43#define RDS_CONNECTION_HASH_ENTRIES (1 << RDS_CONNECTION_HASH_BITS)
44#define RDS_CONNECTION_HASH_MASK (RDS_CONNECTION_HASH_ENTRIES - 1)
45
46
47static DEFINE_SPINLOCK(rds_conn_lock);
48static unsigned long rds_conn_count;
49static struct hlist_head rds_conn_hash[RDS_CONNECTION_HASH_ENTRIES];
50static struct kmem_cache *rds_conn_slab;
51
52static struct hlist_head *rds_conn_bucket(__be32 laddr, __be32 faddr)
53{
54 static u32 rds_hash_secret __read_mostly;
55
56 unsigned long hash;
57
58 net_get_random_once(&rds_hash_secret, sizeof(rds_hash_secret));
59
60
61 hash = __inet_ehashfn(be32_to_cpu(laddr), 0,
62 be32_to_cpu(faddr), 0,
63 rds_hash_secret);
64 return &rds_conn_hash[hash & RDS_CONNECTION_HASH_MASK];
65}
66
67#define rds_conn_info_set(var, test, suffix) do { \
68 if (test) \
69 var |= RDS_INFO_CONNECTION_FLAG_##suffix; \
70} while (0)
71
72
73static struct rds_connection *rds_conn_lookup(struct net *net,
74 struct hlist_head *head,
75 __be32 laddr, __be32 faddr,
76 struct rds_transport *trans)
77{
78 struct rds_connection *conn, *ret = NULL;
79
80 hlist_for_each_entry_rcu(conn, head, c_hash_node) {
81 if (conn->c_faddr == faddr && conn->c_laddr == laddr &&
82 conn->c_trans == trans && net == rds_conn_net(conn)) {
83 ret = conn;
84 break;
85 }
86 }
87 rdsdebug("returning conn %p for %pI4 -> %pI4\n", ret,
88 &laddr, &faddr);
89 return ret;
90}
91
92
93
94
95
96
97
98static void rds_conn_reset(struct rds_connection *conn)
99{
100 rdsdebug("connection %pI4 to %pI4 reset\n",
101 &conn->c_laddr, &conn->c_faddr);
102
103 rds_stats_inc(s_conn_reset);
104 rds_send_reset(conn);
105 conn->c_flags = 0;
106
107
108
109
110
111}
112
113
114
115
116
117
118
119
120
121static struct rds_connection *__rds_conn_create(struct net *net,
122 __be32 laddr, __be32 faddr,
123 struct rds_transport *trans, gfp_t gfp,
124 int is_outgoing)
125{
126 struct rds_connection *conn, *parent = NULL;
127 struct hlist_head *head = rds_conn_bucket(laddr, faddr);
128 struct rds_transport *loop_trans;
129 unsigned long flags;
130 int ret;
131
132 rcu_read_lock();
133 conn = rds_conn_lookup(net, head, laddr, faddr, trans);
134 if (conn && conn->c_loopback && conn->c_trans != &rds_loop_transport &&
135 laddr == faddr && !is_outgoing) {
136
137
138
139
140 parent = conn;
141 conn = parent->c_passive;
142 }
143 rcu_read_unlock();
144 if (conn)
145 goto out;
146
147 conn = kmem_cache_zalloc(rds_conn_slab, gfp);
148 if (!conn) {
149 conn = ERR_PTR(-ENOMEM);
150 goto out;
151 }
152
153 INIT_HLIST_NODE(&conn->c_hash_node);
154 conn->c_laddr = laddr;
155 conn->c_faddr = faddr;
156 spin_lock_init(&conn->c_lock);
157 conn->c_next_tx_seq = 1;
158 rds_conn_net_set(conn, net);
159
160 init_waitqueue_head(&conn->c_waitq);
161 INIT_LIST_HEAD(&conn->c_send_queue);
162 INIT_LIST_HEAD(&conn->c_retrans);
163
164 ret = rds_cong_get_maps(conn);
165 if (ret) {
166 kmem_cache_free(rds_conn_slab, conn);
167 conn = ERR_PTR(ret);
168 goto out;
169 }
170
171
172
173
174
175
176 loop_trans = rds_trans_get_preferred(net, faddr);
177 if (loop_trans) {
178 rds_trans_put(loop_trans);
179 conn->c_loopback = 1;
180 if (is_outgoing && trans->t_prefer_loopback) {
181
182
183
184
185 trans = &rds_loop_transport;
186 }
187 }
188
189 conn->c_trans = trans;
190
191 ret = trans->conn_alloc(conn, gfp);
192 if (ret) {
193 kmem_cache_free(rds_conn_slab, conn);
194 conn = ERR_PTR(ret);
195 goto out;
196 }
197
198 atomic_set(&conn->c_state, RDS_CONN_DOWN);
199 conn->c_send_gen = 0;
200 conn->c_outgoing = (is_outgoing ? 1 : 0);
201 conn->c_reconnect_jiffies = 0;
202 INIT_DELAYED_WORK(&conn->c_send_w, rds_send_worker);
203 INIT_DELAYED_WORK(&conn->c_recv_w, rds_recv_worker);
204 INIT_DELAYED_WORK(&conn->c_conn_w, rds_connect_worker);
205 INIT_WORK(&conn->c_down_w, rds_shutdown_worker);
206 mutex_init(&conn->c_cm_lock);
207 conn->c_flags = 0;
208
209 rdsdebug("allocated conn %p for %pI4 -> %pI4 over %s %s\n",
210 conn, &laddr, &faddr,
211 trans->t_name ? trans->t_name : "[unknown]",
212 is_outgoing ? "(outgoing)" : "");
213
214
215
216
217
218
219
220
221 spin_lock_irqsave(&rds_conn_lock, flags);
222 if (parent) {
223
224 if (parent->c_passive) {
225 trans->conn_free(conn->c_transport_data);
226 kmem_cache_free(rds_conn_slab, conn);
227 conn = parent->c_passive;
228 } else {
229 parent->c_passive = conn;
230 rds_cong_add_conn(conn);
231 rds_conn_count++;
232 }
233 } else {
234
235 struct rds_connection *found;
236
237 found = rds_conn_lookup(net, head, laddr, faddr, trans);
238 if (found) {
239 trans->conn_free(conn->c_transport_data);
240 kmem_cache_free(rds_conn_slab, conn);
241 conn = found;
242 } else {
243 hlist_add_head_rcu(&conn->c_hash_node, head);
244 rds_cong_add_conn(conn);
245 rds_conn_count++;
246 }
247 }
248 spin_unlock_irqrestore(&rds_conn_lock, flags);
249
250out:
251 return conn;
252}
253
254struct rds_connection *rds_conn_create(struct net *net,
255 __be32 laddr, __be32 faddr,
256 struct rds_transport *trans, gfp_t gfp)
257{
258 return __rds_conn_create(net, laddr, faddr, trans, gfp, 0);
259}
260EXPORT_SYMBOL_GPL(rds_conn_create);
261
262struct rds_connection *rds_conn_create_outgoing(struct net *net,
263 __be32 laddr, __be32 faddr,
264 struct rds_transport *trans, gfp_t gfp)
265{
266 return __rds_conn_create(net, laddr, faddr, trans, gfp, 1);
267}
268EXPORT_SYMBOL_GPL(rds_conn_create_outgoing);
269
270void rds_conn_shutdown(struct rds_connection *conn)
271{
272
273 if (!rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_DOWN)) {
274
275
276
277
278
279
280
281 mutex_lock(&conn->c_cm_lock);
282 if (!rds_conn_transition(conn, RDS_CONN_UP, RDS_CONN_DISCONNECTING)
283 && !rds_conn_transition(conn, RDS_CONN_ERROR, RDS_CONN_DISCONNECTING)) {
284 rds_conn_error(conn, "shutdown called in state %d\n",
285 atomic_read(&conn->c_state));
286 mutex_unlock(&conn->c_cm_lock);
287 return;
288 }
289 mutex_unlock(&conn->c_cm_lock);
290
291 wait_event(conn->c_waitq,
292 !test_bit(RDS_IN_XMIT, &conn->c_flags));
293 wait_event(conn->c_waitq,
294 !test_bit(RDS_RECV_REFILL, &conn->c_flags));
295
296 conn->c_trans->conn_shutdown(conn);
297 rds_conn_reset(conn);
298
299 if (!rds_conn_transition(conn, RDS_CONN_DISCONNECTING, RDS_CONN_DOWN)) {
300
301
302
303
304
305 rds_conn_error(conn,
306 "%s: failed to transition to state DOWN, "
307 "current state is %d\n",
308 __func__,
309 atomic_read(&conn->c_state));
310 return;
311 }
312 }
313
314
315
316
317
318 cancel_delayed_work_sync(&conn->c_conn_w);
319 rcu_read_lock();
320 if (!hlist_unhashed(&conn->c_hash_node)) {
321 rcu_read_unlock();
322 if (conn->c_trans->t_type != RDS_TRANS_TCP ||
323 conn->c_outgoing == 1)
324 rds_queue_reconnect(conn);
325 } else {
326 rcu_read_unlock();
327 }
328}
329
330
331
332
333
334
335
336
337void rds_conn_destroy(struct rds_connection *conn)
338{
339 struct rds_message *rm, *rtmp;
340 unsigned long flags;
341
342 rdsdebug("freeing conn %p for %pI4 -> "
343 "%pI4\n", conn, &conn->c_laddr,
344 &conn->c_faddr);
345
346
347 spin_lock_irq(&rds_conn_lock);
348 hlist_del_init_rcu(&conn->c_hash_node);
349 spin_unlock_irq(&rds_conn_lock);
350 synchronize_rcu();
351
352
353 rds_conn_drop(conn);
354 flush_work(&conn->c_down_w);
355
356
357 cancel_delayed_work_sync(&conn->c_send_w);
358 cancel_delayed_work_sync(&conn->c_recv_w);
359
360
361 list_for_each_entry_safe(rm, rtmp,
362 &conn->c_send_queue,
363 m_conn_item) {
364 list_del_init(&rm->m_conn_item);
365 BUG_ON(!list_empty(&rm->m_sock_item));
366 rds_message_put(rm);
367 }
368 if (conn->c_xmit_rm)
369 rds_message_put(conn->c_xmit_rm);
370
371 conn->c_trans->conn_free(conn->c_transport_data);
372
373
374
375
376
377
378 rds_cong_remove_conn(conn);
379
380 BUG_ON(!list_empty(&conn->c_retrans));
381 kmem_cache_free(rds_conn_slab, conn);
382
383 spin_lock_irqsave(&rds_conn_lock, flags);
384 rds_conn_count--;
385 spin_unlock_irqrestore(&rds_conn_lock, flags);
386}
387EXPORT_SYMBOL_GPL(rds_conn_destroy);
388
389static void rds_conn_message_info(struct socket *sock, unsigned int len,
390 struct rds_info_iterator *iter,
391 struct rds_info_lengths *lens,
392 int want_send)
393{
394 struct hlist_head *head;
395 struct list_head *list;
396 struct rds_connection *conn;
397 struct rds_message *rm;
398 unsigned int total = 0;
399 unsigned long flags;
400 size_t i;
401
402 len /= sizeof(struct rds_info_message);
403
404 rcu_read_lock();
405
406 for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
407 i++, head++) {
408 hlist_for_each_entry_rcu(conn, head, c_hash_node) {
409 if (want_send)
410 list = &conn->c_send_queue;
411 else
412 list = &conn->c_retrans;
413
414 spin_lock_irqsave(&conn->c_lock, flags);
415
416
417 list_for_each_entry(rm, list, m_conn_item) {
418 total++;
419 if (total <= len)
420 rds_inc_info_copy(&rm->m_inc, iter,
421 conn->c_laddr,
422 conn->c_faddr, 0);
423 }
424
425 spin_unlock_irqrestore(&conn->c_lock, flags);
426 }
427 }
428 rcu_read_unlock();
429
430 lens->nr = total;
431 lens->each = sizeof(struct rds_info_message);
432}
433
434static void rds_conn_message_info_send(struct socket *sock, unsigned int len,
435 struct rds_info_iterator *iter,
436 struct rds_info_lengths *lens)
437{
438 rds_conn_message_info(sock, len, iter, lens, 1);
439}
440
441static void rds_conn_message_info_retrans(struct socket *sock,
442 unsigned int len,
443 struct rds_info_iterator *iter,
444 struct rds_info_lengths *lens)
445{
446 rds_conn_message_info(sock, len, iter, lens, 0);
447}
448
449void rds_for_each_conn_info(struct socket *sock, unsigned int len,
450 struct rds_info_iterator *iter,
451 struct rds_info_lengths *lens,
452 int (*visitor)(struct rds_connection *, void *),
453 size_t item_len)
454{
455 uint64_t buffer[(item_len + 7) / 8];
456 struct hlist_head *head;
457 struct rds_connection *conn;
458 size_t i;
459
460 rcu_read_lock();
461
462 lens->nr = 0;
463 lens->each = item_len;
464
465 for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
466 i++, head++) {
467 hlist_for_each_entry_rcu(conn, head, c_hash_node) {
468
469
470 if (!visitor(conn, buffer))
471 continue;
472
473
474
475
476 if (len >= item_len) {
477 rds_info_copy(iter, buffer, item_len);
478 len -= item_len;
479 }
480 lens->nr++;
481 }
482 }
483 rcu_read_unlock();
484}
485EXPORT_SYMBOL_GPL(rds_for_each_conn_info);
486
487static int rds_conn_info_visitor(struct rds_connection *conn,
488 void *buffer)
489{
490 struct rds_info_connection *cinfo = buffer;
491
492 cinfo->next_tx_seq = conn->c_next_tx_seq;
493 cinfo->next_rx_seq = conn->c_next_rx_seq;
494 cinfo->laddr = conn->c_laddr;
495 cinfo->faddr = conn->c_faddr;
496 strncpy(cinfo->transport, conn->c_trans->t_name,
497 sizeof(cinfo->transport));
498 cinfo->flags = 0;
499
500 rds_conn_info_set(cinfo->flags, test_bit(RDS_IN_XMIT, &conn->c_flags),
501 SENDING);
502
503 rds_conn_info_set(cinfo->flags,
504 atomic_read(&conn->c_state) == RDS_CONN_CONNECTING,
505 CONNECTING);
506 rds_conn_info_set(cinfo->flags,
507 atomic_read(&conn->c_state) == RDS_CONN_UP,
508 CONNECTED);
509 return 1;
510}
511
512static void rds_conn_info(struct socket *sock, unsigned int len,
513 struct rds_info_iterator *iter,
514 struct rds_info_lengths *lens)
515{
516 rds_for_each_conn_info(sock, len, iter, lens,
517 rds_conn_info_visitor,
518 sizeof(struct rds_info_connection));
519}
520
521int rds_conn_init(void)
522{
523 rds_conn_slab = kmem_cache_create("rds_connection",
524 sizeof(struct rds_connection),
525 0, 0, NULL);
526 if (!rds_conn_slab)
527 return -ENOMEM;
528
529 rds_info_register_func(RDS_INFO_CONNECTIONS, rds_conn_info);
530 rds_info_register_func(RDS_INFO_SEND_MESSAGES,
531 rds_conn_message_info_send);
532 rds_info_register_func(RDS_INFO_RETRANS_MESSAGES,
533 rds_conn_message_info_retrans);
534
535 return 0;
536}
537
538void rds_conn_exit(void)
539{
540 rds_loop_exit();
541
542 WARN_ON(!hlist_empty(rds_conn_hash));
543
544 kmem_cache_destroy(rds_conn_slab);
545
546 rds_info_deregister_func(RDS_INFO_CONNECTIONS, rds_conn_info);
547 rds_info_deregister_func(RDS_INFO_SEND_MESSAGES,
548 rds_conn_message_info_send);
549 rds_info_deregister_func(RDS_INFO_RETRANS_MESSAGES,
550 rds_conn_message_info_retrans);
551}
552
553
554
555
556void rds_conn_drop(struct rds_connection *conn)
557{
558 atomic_set(&conn->c_state, RDS_CONN_ERROR);
559 queue_work(rds_wq, &conn->c_down_w);
560}
561EXPORT_SYMBOL_GPL(rds_conn_drop);
562
563
564
565
566
567void rds_conn_connect_if_down(struct rds_connection *conn)
568{
569 if (rds_conn_state(conn) == RDS_CONN_DOWN &&
570 !test_and_set_bit(RDS_RECONNECT_PENDING, &conn->c_flags))
571 queue_delayed_work(rds_wq, &conn->c_conn_w, 0);
572}
573EXPORT_SYMBOL_GPL(rds_conn_connect_if_down);
574
575
576
577
578void
579__rds_conn_error(struct rds_connection *conn, const char *fmt, ...)
580{
581 va_list ap;
582
583 va_start(ap, fmt);
584 vprintk(fmt, ap);
585 va_end(ap);
586
587 rds_conn_drop(conn);
588}
589