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