2 * Copyright (c) 2006 Oracle. All rights reserved.
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:
10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted provided that the following
14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of conditions and the following
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.
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
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29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
33 #include <linux/kernel.h>
34 #include <linux/list.h>
35 #include <linux/slab.h>
36 #include <net/inet_hashtables.h>
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)
46 /* converting this to RCU is a chore for another day.. */
47 static DEFINE_SPINLOCK(rds_conn_lock);
48 static unsigned long rds_conn_count;
49 static struct hlist_head rds_conn_hash[RDS_CONNECTION_HASH_ENTRIES];
50 static struct kmem_cache *rds_conn_slab;
52 static struct hlist_head *rds_conn_bucket(__be32 laddr, __be32 faddr)
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];
61 #define rds_conn_info_set(var, test, suffix) do { \
63 var |= RDS_INFO_CONNECTION_FLAG_##suffix; \
66 static inline int rds_conn_is_sending(struct rds_connection *conn)
70 if (!mutex_trylock(&conn->c_send_lock))
73 mutex_unlock(&conn->c_send_lock);
78 static struct rds_connection *rds_conn_lookup(struct hlist_head *head,
79 __be32 laddr, __be32 faddr,
80 struct rds_transport *trans)
82 struct rds_connection *conn, *ret = NULL;
83 struct hlist_node *pos;
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) {
92 rdsdebug("returning conn %p for %pI4 -> %pI4\n", ret,
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.
103 void rds_conn_reset(struct rds_connection *conn)
105 rdsdebug("connection %pI4 to %pI4 reset\n",
106 &conn->c_laddr, &conn->c_faddr);
108 rds_stats_inc(s_conn_reset);
109 rds_send_reset(conn);
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. */
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.
123 * For now they are not garbage collected once they're created. They
124 * are torn down as the module is removed, if ever.
126 static struct rds_connection *__rds_conn_create(__be32 laddr, __be32 faddr,
127 struct rds_transport *trans, gfp_t gfp,
130 struct rds_connection *conn, *parent = NULL;
131 struct hlist_head *head = rds_conn_bucket(laddr, faddr);
135 spin_lock_irqsave(&rds_conn_lock, flags);
136 conn = rds_conn_lookup(head, laddr, faddr, trans);
137 if (conn && conn->c_loopback && conn->c_trans != &rds_loop_transport &&
139 /* 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. */
144 conn = parent->c_passive;
146 spin_unlock_irqrestore(&rds_conn_lock, flags);
150 conn = kmem_cache_zalloc(rds_conn_slab, gfp);
152 conn = ERR_PTR(-ENOMEM);
156 INIT_HLIST_NODE(&conn->c_hash_node);
157 conn->c_laddr = laddr;
158 conn->c_faddr = faddr;
159 spin_lock_init(&conn->c_lock);
160 conn->c_next_tx_seq = 1;
162 mutex_init(&conn->c_send_lock);
163 INIT_LIST_HEAD(&conn->c_send_queue);
164 INIT_LIST_HEAD(&conn->c_retrans);
166 ret = rds_cong_get_maps(conn);
168 kmem_cache_free(rds_conn_slab, conn);
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.
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.
185 trans = &rds_loop_transport;
189 conn->c_trans = trans;
191 ret = trans->conn_alloc(conn, gfp);
193 kmem_cache_free(rds_conn_slab, conn);
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);
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)" : "");
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
219 spin_lock_irqsave(&rds_conn_lock, flags);
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;
227 parent->c_passive = conn;
228 rds_cong_add_conn(conn);
232 /* Creating normal conn */
233 struct rds_connection *found;
235 found = rds_conn_lookup(head, laddr, faddr, trans);
237 trans->conn_free(conn->c_transport_data);
238 kmem_cache_free(rds_conn_slab, conn);
241 hlist_add_head(&conn->c_hash_node, head);
242 rds_cong_add_conn(conn);
246 spin_unlock_irqrestore(&rds_conn_lock, flags);
252 struct rds_connection *rds_conn_create(__be32 laddr, __be32 faddr,
253 struct rds_transport *trans, gfp_t gfp)
255 return __rds_conn_create(laddr, faddr, trans, gfp, 0);
257 EXPORT_SYMBOL_GPL(rds_conn_create);
259 struct rds_connection *rds_conn_create_outgoing(__be32 laddr, __be32 faddr,
260 struct rds_transport *trans, gfp_t gfp)
262 return __rds_conn_create(laddr, faddr, trans, gfp, 1);
264 EXPORT_SYMBOL_GPL(rds_conn_create_outgoing);
266 void rds_conn_destroy(struct rds_connection *conn)
268 struct rds_message *rm, *rtmp;
270 rdsdebug("freeing conn %p for %pI4 -> "
271 "%pI4\n", conn, &conn->c_laddr,
274 hlist_del_init(&conn->c_hash_node);
276 /* wait for the rds thread to shut it down */
277 atomic_set(&conn->c_state, RDS_CONN_ERROR);
278 cancel_delayed_work(&conn->c_conn_w);
279 queue_work(rds_wq, &conn->c_down_w);
280 flush_workqueue(rds_wq);
282 /* tear down queued messages */
283 list_for_each_entry_safe(rm, rtmp,
286 list_del_init(&rm->m_conn_item);
287 BUG_ON(!list_empty(&rm->m_sock_item));
291 rds_message_put(conn->c_xmit_rm);
293 conn->c_trans->conn_free(conn->c_transport_data);
296 * The congestion maps aren't freed up here. They're
297 * freed by rds_cong_exit() after all the connections
300 rds_cong_remove_conn(conn);
302 BUG_ON(!list_empty(&conn->c_retrans));
303 kmem_cache_free(rds_conn_slab, conn);
307 EXPORT_SYMBOL_GPL(rds_conn_destroy);
309 static void rds_conn_message_info(struct socket *sock, unsigned int len,
310 struct rds_info_iterator *iter,
311 struct rds_info_lengths *lens,
314 struct hlist_head *head;
315 struct hlist_node *pos;
316 struct list_head *list;
317 struct rds_connection *conn;
318 struct rds_message *rm;
320 unsigned int total = 0;
323 len /= sizeof(struct rds_info_message);
325 spin_lock_irqsave(&rds_conn_lock, flags);
327 for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
329 hlist_for_each_entry(conn, pos, head, c_hash_node) {
331 list = &conn->c_send_queue;
333 list = &conn->c_retrans;
335 spin_lock(&conn->c_lock);
337 /* XXX too lazy to maintain counts.. */
338 list_for_each_entry(rm, list, m_conn_item) {
341 rds_inc_info_copy(&rm->m_inc, iter,
346 spin_unlock(&conn->c_lock);
350 spin_unlock_irqrestore(&rds_conn_lock, flags);
353 lens->each = sizeof(struct rds_info_message);
356 static void rds_conn_message_info_send(struct socket *sock, unsigned int len,
357 struct rds_info_iterator *iter,
358 struct rds_info_lengths *lens)
360 rds_conn_message_info(sock, len, iter, lens, 1);
363 static void rds_conn_message_info_retrans(struct socket *sock,
365 struct rds_info_iterator *iter,
366 struct rds_info_lengths *lens)
368 rds_conn_message_info(sock, len, iter, lens, 0);
371 void rds_for_each_conn_info(struct socket *sock, unsigned int len,
372 struct rds_info_iterator *iter,
373 struct rds_info_lengths *lens,
374 int (*visitor)(struct rds_connection *, void *),
377 uint64_t buffer[(item_len + 7) / 8];
378 struct hlist_head *head;
379 struct hlist_node *pos;
380 struct hlist_node *tmp;
381 struct rds_connection *conn;
385 spin_lock_irqsave(&rds_conn_lock, flags);
388 lens->each = item_len;
390 for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
392 hlist_for_each_entry_safe(conn, pos, tmp, head, c_hash_node) {
394 /* XXX no c_lock usage.. */
395 if (!visitor(conn, buffer))
398 /* We copy as much as we can fit in the buffer,
399 * but we count all items so that the caller
400 * can resize the buffer. */
401 if (len >= item_len) {
402 rds_info_copy(iter, buffer, item_len);
409 spin_unlock_irqrestore(&rds_conn_lock, flags);
411 EXPORT_SYMBOL_GPL(rds_for_each_conn_info);
413 static int rds_conn_info_visitor(struct rds_connection *conn,
416 struct rds_info_connection *cinfo = buffer;
418 cinfo->next_tx_seq = conn->c_next_tx_seq;
419 cinfo->next_rx_seq = conn->c_next_rx_seq;
420 cinfo->laddr = conn->c_laddr;
421 cinfo->faddr = conn->c_faddr;
422 strncpy(cinfo->transport, conn->c_trans->t_name,
423 sizeof(cinfo->transport));
426 rds_conn_info_set(cinfo->flags,
427 rds_conn_is_sending(conn), SENDING);
428 /* XXX Future: return the state rather than these funky bits */
429 rds_conn_info_set(cinfo->flags,
430 atomic_read(&conn->c_state) == RDS_CONN_CONNECTING,
432 rds_conn_info_set(cinfo->flags,
433 atomic_read(&conn->c_state) == RDS_CONN_UP,
438 static void rds_conn_info(struct socket *sock, unsigned int len,
439 struct rds_info_iterator *iter,
440 struct rds_info_lengths *lens)
442 rds_for_each_conn_info(sock, len, iter, lens,
443 rds_conn_info_visitor,
444 sizeof(struct rds_info_connection));
447 int __init rds_conn_init(void)
449 rds_conn_slab = kmem_cache_create("rds_connection",
450 sizeof(struct rds_connection),
452 if (rds_conn_slab == NULL)
455 rds_info_register_func(RDS_INFO_CONNECTIONS, rds_conn_info);
456 rds_info_register_func(RDS_INFO_SEND_MESSAGES,
457 rds_conn_message_info_send);
458 rds_info_register_func(RDS_INFO_RETRANS_MESSAGES,
459 rds_conn_message_info_retrans);
464 void rds_conn_exit(void)
468 WARN_ON(!hlist_empty(rds_conn_hash));
470 kmem_cache_destroy(rds_conn_slab);
472 rds_info_deregister_func(RDS_INFO_CONNECTIONS, rds_conn_info);
473 rds_info_deregister_func(RDS_INFO_SEND_MESSAGES,
474 rds_conn_message_info_send);
475 rds_info_deregister_func(RDS_INFO_RETRANS_MESSAGES,
476 rds_conn_message_info_retrans);
482 void rds_conn_drop(struct rds_connection *conn)
484 atomic_set(&conn->c_state, RDS_CONN_ERROR);
485 queue_work(rds_wq, &conn->c_down_w);
487 EXPORT_SYMBOL_GPL(rds_conn_drop);
490 * An error occurred on the connection
493 __rds_conn_error(struct rds_connection *conn, const char *fmt, ...)