blob: 895e39cdc6a66c4ccc7bbc057ff5412a47b4e8fa [file] [log] [blame]
Andy Grover00e0f342009-02-24 15:30:23 +00001/*
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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090035#include <linux/slab.h>
Andy Grover00e0f342009-02-24 15:30:23 +000036#include <net/inet_hashtables.h>
37
38#include "rds.h"
39#include "loop.h"
40#include "rdma.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/* converting this to RCU is a chore for another day.. */
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 /* Pass NULL, don't need struct net for hash */
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
66static inline int rds_conn_is_sending(struct rds_connection *conn)
67{
68 int ret = 0;
69
70 if (!mutex_trylock(&conn->c_send_lock))
71 ret = 1;
72 else
73 mutex_unlock(&conn->c_send_lock);
74
75 return ret;
76}
77
78static struct rds_connection *rds_conn_lookup(struct hlist_head *head,
79 __be32 laddr, __be32 faddr,
80 struct rds_transport *trans)
81{
82 struct rds_connection *conn, *ret = NULL;
83 struct hlist_node *pos;
84
85 hlist_for_each_entry(conn, pos, head, c_hash_node) {
86 if (conn->c_faddr == faddr && conn->c_laddr == laddr &&
87 conn->c_trans == trans) {
88 ret = conn;
89 break;
90 }
91 }
92 rdsdebug("returning conn %p for %pI4 -> %pI4\n", ret,
93 &laddr, &faddr);
94 return ret;
95}
96
97/*
98 * This is called by transports as they're bringing down a connection.
99 * It clears partial message state so that the transport can start sending
100 * and receiving over this connection again in the future. It is up to
101 * the transport to have serialized this call with its send and recv.
102 */
103void rds_conn_reset(struct rds_connection *conn)
104{
105 rdsdebug("connection %pI4 to %pI4 reset\n",
106 &conn->c_laddr, &conn->c_faddr);
107
108 rds_stats_inc(s_conn_reset);
109 rds_send_reset(conn);
110 conn->c_flags = 0;
111
112 /* Do not clear next_rx_seq here, else we cannot distinguish
113 * retransmitted packets from new packets, and will hand all
114 * of them to the application. That is not consistent with the
115 * reliability guarantees of RDS. */
116}
117
118/*
119 * There is only every one 'conn' for a given pair of addresses in the
120 * system at a time. They contain messages to be retransmitted and so
121 * span the lifetime of the actual underlying transport connections.
122 *
123 * For now they are not garbage collected once they're created. They
124 * are torn down as the module is removed, if ever.
125 */
126static struct rds_connection *__rds_conn_create(__be32 laddr, __be32 faddr,
127 struct rds_transport *trans, gfp_t gfp,
128 int is_outgoing)
129{
Andy Grovercb244052009-07-17 13:13:36 +0000130 struct rds_connection *conn, *parent = NULL;
Andy Grover00e0f342009-02-24 15:30:23 +0000131 struct hlist_head *head = rds_conn_bucket(laddr, faddr);
132 unsigned long flags;
133 int ret;
134
135 spin_lock_irqsave(&rds_conn_lock, flags);
136 conn = rds_conn_lookup(head, laddr, faddr, trans);
Joe Perchesf64f9e72009-11-29 16:55:45 -0800137 if (conn && conn->c_loopback && conn->c_trans != &rds_loop_transport &&
138 !is_outgoing) {
Andy Grover00e0f342009-02-24 15:30:23 +0000139 /* This is a looped back IB connection, and we're
140 * called by the code handling the incoming connect.
141 * We need a second connection object into which we
142 * can stick the other QP. */
143 parent = conn;
144 conn = parent->c_passive;
145 }
146 spin_unlock_irqrestore(&rds_conn_lock, flags);
147 if (conn)
148 goto out;
149
Wei Yongjun05a178e2009-04-09 14:09:44 +0000150 conn = kmem_cache_zalloc(rds_conn_slab, gfp);
Andy Grover00e0f342009-02-24 15:30:23 +0000151 if (conn == NULL) {
152 conn = ERR_PTR(-ENOMEM);
153 goto out;
154 }
155
Andy Grover00e0f342009-02-24 15:30:23 +0000156 INIT_HLIST_NODE(&conn->c_hash_node);
Andy Grover00e0f342009-02-24 15:30:23 +0000157 conn->c_laddr = laddr;
158 conn->c_faddr = faddr;
159 spin_lock_init(&conn->c_lock);
160 conn->c_next_tx_seq = 1;
161
162 mutex_init(&conn->c_send_lock);
163 INIT_LIST_HEAD(&conn->c_send_queue);
164 INIT_LIST_HEAD(&conn->c_retrans);
165
166 ret = rds_cong_get_maps(conn);
167 if (ret) {
168 kmem_cache_free(rds_conn_slab, conn);
169 conn = ERR_PTR(ret);
170 goto out;
171 }
172
173 /*
174 * This is where a connection becomes loopback. If *any* RDS sockets
175 * can bind to the destination address then we'd rather the messages
176 * flow through loopback rather than either transport.
177 */
178 if (rds_trans_get_preferred(faddr)) {
179 conn->c_loopback = 1;
180 if (is_outgoing && trans->t_prefer_loopback) {
181 /* "outgoing" connection - and the transport
182 * says it wants the connection handled by the
183 * loopback transport. This is what TCP does.
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_reconnect_jiffies = 0;
200 INIT_DELAYED_WORK(&conn->c_send_w, rds_send_worker);
201 INIT_DELAYED_WORK(&conn->c_recv_w, rds_recv_worker);
202 INIT_DELAYED_WORK(&conn->c_conn_w, rds_connect_worker);
203 INIT_WORK(&conn->c_down_w, rds_shutdown_worker);
204 mutex_init(&conn->c_cm_lock);
205 conn->c_flags = 0;
206
207 rdsdebug("allocated conn %p for %pI4 -> %pI4 over %s %s\n",
208 conn, &laddr, &faddr,
209 trans->t_name ? trans->t_name : "[unknown]",
210 is_outgoing ? "(outgoing)" : "");
211
Andy Grovercb244052009-07-17 13:13:36 +0000212 /*
213 * Since we ran without holding the conn lock, someone could
214 * have created the same conn (either normal or passive) in the
215 * interim. We check while holding the lock. If we won, we complete
216 * init and return our conn. If we lost, we rollback and return the
217 * other one.
218 */
Andy Grover00e0f342009-02-24 15:30:23 +0000219 spin_lock_irqsave(&rds_conn_lock, flags);
Andy Grovercb244052009-07-17 13:13:36 +0000220 if (parent) {
221 /* Creating passive conn */
222 if (parent->c_passive) {
223 trans->conn_free(conn->c_transport_data);
224 kmem_cache_free(rds_conn_slab, conn);
225 conn = parent->c_passive;
226 } else {
Andy Grover00e0f342009-02-24 15:30:23 +0000227 parent->c_passive = conn;
Andy Grovercb244052009-07-17 13:13:36 +0000228 rds_cong_add_conn(conn);
229 rds_conn_count++;
230 }
Andy Grover00e0f342009-02-24 15:30:23 +0000231 } else {
Andy Grovercb244052009-07-17 13:13:36 +0000232 /* Creating normal conn */
233 struct rds_connection *found;
Andy Grover00e0f342009-02-24 15:30:23 +0000234
Andy Grovercb244052009-07-17 13:13:36 +0000235 found = rds_conn_lookup(head, laddr, faddr, trans);
236 if (found) {
237 trans->conn_free(conn->c_transport_data);
238 kmem_cache_free(rds_conn_slab, conn);
239 conn = found;
240 } else {
241 hlist_add_head(&conn->c_hash_node, head);
242 rds_cong_add_conn(conn);
243 rds_conn_count++;
244 }
245 }
Andy Grover00e0f342009-02-24 15:30:23 +0000246 spin_unlock_irqrestore(&rds_conn_lock, flags);
247
248out:
249 return conn;
250}
251
252struct rds_connection *rds_conn_create(__be32 laddr, __be32 faddr,
253 struct rds_transport *trans, gfp_t gfp)
254{
255 return __rds_conn_create(laddr, faddr, trans, gfp, 0);
256}
Andy Grover616b7572009-08-21 12:28:32 +0000257EXPORT_SYMBOL_GPL(rds_conn_create);
Andy Grover00e0f342009-02-24 15:30:23 +0000258
259struct rds_connection *rds_conn_create_outgoing(__be32 laddr, __be32 faddr,
260 struct rds_transport *trans, gfp_t gfp)
261{
262 return __rds_conn_create(laddr, faddr, trans, gfp, 1);
263}
Andy Grover616b7572009-08-21 12:28:32 +0000264EXPORT_SYMBOL_GPL(rds_conn_create_outgoing);
Andy Grover00e0f342009-02-24 15:30:23 +0000265
Andy Grover2dc39352010-06-11 13:49:13 -0700266void rds_conn_shutdown(struct rds_connection *conn)
267{
268 /* shut it down unless it's down already */
269 if (!rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_DOWN)) {
270 /*
271 * Quiesce the connection mgmt handlers before we start tearing
272 * things down. We don't hold the mutex for the entire
273 * duration of the shutdown operation, else we may be
274 * deadlocking with the CM handler. Instead, the CM event
275 * handler is supposed to check for state DISCONNECTING
276 */
277 mutex_lock(&conn->c_cm_lock);
278 if (!rds_conn_transition(conn, RDS_CONN_UP, RDS_CONN_DISCONNECTING)
279 && !rds_conn_transition(conn, RDS_CONN_ERROR, RDS_CONN_DISCONNECTING)) {
280 rds_conn_error(conn, "shutdown called in state %d\n",
281 atomic_read(&conn->c_state));
282 mutex_unlock(&conn->c_cm_lock);
283 return;
284 }
285 mutex_unlock(&conn->c_cm_lock);
286
287 mutex_lock(&conn->c_send_lock);
288 conn->c_trans->conn_shutdown(conn);
289 rds_conn_reset(conn);
290 mutex_unlock(&conn->c_send_lock);
291
292 if (!rds_conn_transition(conn, RDS_CONN_DISCONNECTING, RDS_CONN_DOWN)) {
293 /* This can happen - eg when we're in the middle of tearing
294 * down the connection, and someone unloads the rds module.
295 * Quite reproduceable with loopback connections.
296 * Mostly harmless.
297 */
298 rds_conn_error(conn,
299 "%s: failed to transition to state DOWN, "
300 "current state is %d\n",
301 __func__,
302 atomic_read(&conn->c_state));
303 return;
304 }
305 }
306
307 /* Then reconnect if it's still live.
308 * The passive side of an IB loopback connection is never added
309 * to the conn hash, so we never trigger a reconnect on this
310 * conn - the reconnect is always triggered by the active peer. */
311 cancel_delayed_work_sync(&conn->c_conn_w);
312 if (!hlist_unhashed(&conn->c_hash_node))
313 rds_queue_reconnect(conn);
314}
315
316/*
317 * Stop and free a connection.
318 */
Andy Grover00e0f342009-02-24 15:30:23 +0000319void rds_conn_destroy(struct rds_connection *conn)
320{
321 struct rds_message *rm, *rtmp;
322
323 rdsdebug("freeing conn %p for %pI4 -> "
324 "%pI4\n", conn, &conn->c_laddr,
325 &conn->c_faddr);
326
327 hlist_del_init(&conn->c_hash_node);
328
329 /* wait for the rds thread to shut it down */
330 atomic_set(&conn->c_state, RDS_CONN_ERROR);
331 cancel_delayed_work(&conn->c_conn_w);
332 queue_work(rds_wq, &conn->c_down_w);
333 flush_workqueue(rds_wq);
334
335 /* tear down queued messages */
336 list_for_each_entry_safe(rm, rtmp,
337 &conn->c_send_queue,
338 m_conn_item) {
339 list_del_init(&rm->m_conn_item);
340 BUG_ON(!list_empty(&rm->m_sock_item));
341 rds_message_put(rm);
342 }
343 if (conn->c_xmit_rm)
344 rds_message_put(conn->c_xmit_rm);
345
346 conn->c_trans->conn_free(conn->c_transport_data);
347
348 /*
349 * The congestion maps aren't freed up here. They're
350 * freed by rds_cong_exit() after all the connections
351 * have been freed.
352 */
353 rds_cong_remove_conn(conn);
354
355 BUG_ON(!list_empty(&conn->c_retrans));
356 kmem_cache_free(rds_conn_slab, conn);
357
358 rds_conn_count--;
359}
Andy Grover616b7572009-08-21 12:28:32 +0000360EXPORT_SYMBOL_GPL(rds_conn_destroy);
Andy Grover00e0f342009-02-24 15:30:23 +0000361
362static void rds_conn_message_info(struct socket *sock, unsigned int len,
363 struct rds_info_iterator *iter,
364 struct rds_info_lengths *lens,
365 int want_send)
366{
367 struct hlist_head *head;
368 struct hlist_node *pos;
369 struct list_head *list;
370 struct rds_connection *conn;
371 struct rds_message *rm;
372 unsigned long flags;
373 unsigned int total = 0;
374 size_t i;
375
376 len /= sizeof(struct rds_info_message);
377
378 spin_lock_irqsave(&rds_conn_lock, flags);
379
380 for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
381 i++, head++) {
382 hlist_for_each_entry(conn, pos, head, c_hash_node) {
383 if (want_send)
384 list = &conn->c_send_queue;
385 else
386 list = &conn->c_retrans;
387
388 spin_lock(&conn->c_lock);
389
390 /* XXX too lazy to maintain counts.. */
391 list_for_each_entry(rm, list, m_conn_item) {
392 total++;
393 if (total <= len)
394 rds_inc_info_copy(&rm->m_inc, iter,
395 conn->c_laddr,
396 conn->c_faddr, 0);
397 }
398
399 spin_unlock(&conn->c_lock);
400 }
401 }
402
403 spin_unlock_irqrestore(&rds_conn_lock, flags);
404
405 lens->nr = total;
406 lens->each = sizeof(struct rds_info_message);
407}
408
409static void rds_conn_message_info_send(struct socket *sock, unsigned int len,
410 struct rds_info_iterator *iter,
411 struct rds_info_lengths *lens)
412{
413 rds_conn_message_info(sock, len, iter, lens, 1);
414}
415
416static void rds_conn_message_info_retrans(struct socket *sock,
417 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, 0);
422}
423
424void rds_for_each_conn_info(struct socket *sock, unsigned int len,
425 struct rds_info_iterator *iter,
426 struct rds_info_lengths *lens,
427 int (*visitor)(struct rds_connection *, void *),
428 size_t item_len)
429{
430 uint64_t buffer[(item_len + 7) / 8];
431 struct hlist_head *head;
432 struct hlist_node *pos;
433 struct hlist_node *tmp;
434 struct rds_connection *conn;
435 unsigned long flags;
436 size_t i;
437
438 spin_lock_irqsave(&rds_conn_lock, flags);
439
440 lens->nr = 0;
441 lens->each = item_len;
442
443 for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
444 i++, head++) {
445 hlist_for_each_entry_safe(conn, pos, tmp, head, c_hash_node) {
446
447 /* XXX no c_lock usage.. */
448 if (!visitor(conn, buffer))
449 continue;
450
451 /* We copy as much as we can fit in the buffer,
452 * but we count all items so that the caller
453 * can resize the buffer. */
454 if (len >= item_len) {
455 rds_info_copy(iter, buffer, item_len);
456 len -= item_len;
457 }
458 lens->nr++;
459 }
460 }
461
462 spin_unlock_irqrestore(&rds_conn_lock, flags);
463}
Andy Grover616b7572009-08-21 12:28:32 +0000464EXPORT_SYMBOL_GPL(rds_for_each_conn_info);
Andy Grover00e0f342009-02-24 15:30:23 +0000465
466static int rds_conn_info_visitor(struct rds_connection *conn,
467 void *buffer)
468{
469 struct rds_info_connection *cinfo = buffer;
470
471 cinfo->next_tx_seq = conn->c_next_tx_seq;
472 cinfo->next_rx_seq = conn->c_next_rx_seq;
473 cinfo->laddr = conn->c_laddr;
474 cinfo->faddr = conn->c_faddr;
475 strncpy(cinfo->transport, conn->c_trans->t_name,
476 sizeof(cinfo->transport));
477 cinfo->flags = 0;
478
479 rds_conn_info_set(cinfo->flags,
480 rds_conn_is_sending(conn), SENDING);
481 /* XXX Future: return the state rather than these funky bits */
482 rds_conn_info_set(cinfo->flags,
483 atomic_read(&conn->c_state) == RDS_CONN_CONNECTING,
484 CONNECTING);
485 rds_conn_info_set(cinfo->flags,
486 atomic_read(&conn->c_state) == RDS_CONN_UP,
487 CONNECTED);
488 return 1;
489}
490
491static void rds_conn_info(struct socket *sock, unsigned int len,
492 struct rds_info_iterator *iter,
493 struct rds_info_lengths *lens)
494{
495 rds_for_each_conn_info(sock, len, iter, lens,
496 rds_conn_info_visitor,
497 sizeof(struct rds_info_connection));
498}
499
500int __init rds_conn_init(void)
501{
502 rds_conn_slab = kmem_cache_create("rds_connection",
503 sizeof(struct rds_connection),
504 0, 0, NULL);
505 if (rds_conn_slab == NULL)
506 return -ENOMEM;
507
508 rds_info_register_func(RDS_INFO_CONNECTIONS, rds_conn_info);
509 rds_info_register_func(RDS_INFO_SEND_MESSAGES,
510 rds_conn_message_info_send);
511 rds_info_register_func(RDS_INFO_RETRANS_MESSAGES,
512 rds_conn_message_info_retrans);
513
514 return 0;
515}
516
517void rds_conn_exit(void)
518{
519 rds_loop_exit();
520
521 WARN_ON(!hlist_empty(rds_conn_hash));
522
523 kmem_cache_destroy(rds_conn_slab);
524
525 rds_info_deregister_func(RDS_INFO_CONNECTIONS, rds_conn_info);
526 rds_info_deregister_func(RDS_INFO_SEND_MESSAGES,
527 rds_conn_message_info_send);
528 rds_info_deregister_func(RDS_INFO_RETRANS_MESSAGES,
529 rds_conn_message_info_retrans);
530}
531
532/*
533 * Force a disconnect
534 */
535void rds_conn_drop(struct rds_connection *conn)
536{
537 atomic_set(&conn->c_state, RDS_CONN_ERROR);
538 queue_work(rds_wq, &conn->c_down_w);
539}
Andy Grover616b7572009-08-21 12:28:32 +0000540EXPORT_SYMBOL_GPL(rds_conn_drop);
Andy Grover00e0f342009-02-24 15:30:23 +0000541
542/*
543 * An error occurred on the connection
544 */
545void
546__rds_conn_error(struct rds_connection *conn, const char *fmt, ...)
547{
548 va_list ap;
549
550 va_start(ap, fmt);
551 vprintk(fmt, ap);
552 va_end(ap);
553
554 rds_conn_drop(conn);
555}