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, *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_zalloc(rds_conn_slab, gfp); 152 if (conn == NULL) { 153 conn = ERR_PTR(-ENOMEM); 154 goto out; 155 } 156 157 INIT_HLIST_NODE(&conn->c_hash_node); 158 conn->c_laddr = laddr; 159 conn->c_faddr = faddr; 160 spin_lock_init(&conn->c_lock); 161 conn->c_next_tx_seq = 1; 162 163 mutex_init(&conn->c_send_lock); 164 INIT_LIST_HEAD(&conn->c_send_queue); 165 INIT_LIST_HEAD(&conn->c_retrans); 166 167 ret = rds_cong_get_maps(conn); 168 if (ret) { 169 kmem_cache_free(rds_conn_slab, conn); 170 conn = ERR_PTR(ret); 171 goto out; 172 } 173 174 /* 175 * This is where a connection becomes loopback. If *any* RDS sockets 176 * can bind to the destination address then we'd rather the messages 177 * flow through loopback rather than either transport. 178 */ 179 if (rds_trans_get_preferred(faddr)) { 180 conn->c_loopback = 1; 181 if (is_outgoing && trans->t_prefer_loopback) { 182 /* "outgoing" connection - and the transport 183 * says it wants the connection handled by the 184 * loopback transport. This is what TCP does. 185 */ 186 trans = &rds_loop_transport; 187 } 188 } 189 190 conn->c_trans = trans; 191 192 ret = trans->conn_alloc(conn, gfp); 193 if (ret) { 194 kmem_cache_free(rds_conn_slab, conn); 195 conn = ERR_PTR(ret); 196 goto out; 197 } 198 199 atomic_set(&conn->c_state, RDS_CONN_DOWN); 200 conn->c_reconnect_jiffies = 0; 201 INIT_DELAYED_WORK(&conn->c_send_w, rds_send_worker); 202 INIT_DELAYED_WORK(&conn->c_recv_w, rds_recv_worker); 203 INIT_DELAYED_WORK(&conn->c_conn_w, rds_connect_worker); 204 INIT_WORK(&conn->c_down_w, rds_shutdown_worker); 205 mutex_init(&conn->c_cm_lock); 206 conn->c_flags = 0; 207 208 rdsdebug("allocated conn %p for %pI4 -> %pI4 over %s %s\n", 209 conn, &laddr, &faddr, 210 trans->t_name ? trans->t_name : "[unknown]", 211 is_outgoing ? "(outgoing)" : ""); 212 213 /* 214 * Since we ran without holding the conn lock, someone could 215 * have created the same conn (either normal or passive) in the 216 * interim. We check while holding the lock. If we won, we complete 217 * init and return our conn. If we lost, we rollback and return the 218 * other one. 219 */ 220 spin_lock_irqsave(&rds_conn_lock, flags); 221 if (parent) { 222 /* Creating passive conn */ 223 if (parent->c_passive) { 224 trans->conn_free(conn->c_transport_data); 225 kmem_cache_free(rds_conn_slab, conn); 226 conn = parent->c_passive; 227 } else { 228 parent->c_passive = conn; 229 rds_cong_add_conn(conn); 230 rds_conn_count++; 231 } 232 } else { 233 /* Creating normal conn */ 234 struct rds_connection *found; 235 236 found = rds_conn_lookup(head, laddr, faddr, trans); 237 if (found) { 238 trans->conn_free(conn->c_transport_data); 239 kmem_cache_free(rds_conn_slab, conn); 240 conn = found; 241 } else { 242 hlist_add_head(&conn->c_hash_node, head); 243 rds_cong_add_conn(conn); 244 rds_conn_count++; 245 } 246 } 247 spin_unlock_irqrestore(&rds_conn_lock, flags); 248 249 out: 250 return conn; 251 } 252 253 struct rds_connection *rds_conn_create(__be32 laddr, __be32 faddr, 254 struct rds_transport *trans, gfp_t gfp) 255 { 256 return __rds_conn_create(laddr, faddr, trans, gfp, 0); 257 } 258 EXPORT_SYMBOL_GPL(rds_conn_create); 259 260 struct rds_connection *rds_conn_create_outgoing(__be32 laddr, __be32 faddr, 261 struct rds_transport *trans, gfp_t gfp) 262 { 263 return __rds_conn_create(laddr, faddr, trans, gfp, 1); 264 } 265 EXPORT_SYMBOL_GPL(rds_conn_create_outgoing); 266 267 void rds_conn_destroy(struct rds_connection *conn) 268 { 269 struct rds_message *rm, *rtmp; 270 271 rdsdebug("freeing conn %p for %pI4 -> " 272 "%pI4\n", conn, &conn->c_laddr, 273 &conn->c_faddr); 274 275 hlist_del_init(&conn->c_hash_node); 276 277 /* wait for the rds thread to shut it down */ 278 atomic_set(&conn->c_state, RDS_CONN_ERROR); 279 cancel_delayed_work(&conn->c_conn_w); 280 queue_work(rds_wq, &conn->c_down_w); 281 flush_workqueue(rds_wq); 282 283 /* tear down queued messages */ 284 list_for_each_entry_safe(rm, rtmp, 285 &conn->c_send_queue, 286 m_conn_item) { 287 list_del_init(&rm->m_conn_item); 288 BUG_ON(!list_empty(&rm->m_sock_item)); 289 rds_message_put(rm); 290 } 291 if (conn->c_xmit_rm) 292 rds_message_put(conn->c_xmit_rm); 293 294 conn->c_trans->conn_free(conn->c_transport_data); 295 296 /* 297 * The congestion maps aren't freed up here. They're 298 * freed by rds_cong_exit() after all the connections 299 * have been freed. 300 */ 301 rds_cong_remove_conn(conn); 302 303 BUG_ON(!list_empty(&conn->c_retrans)); 304 kmem_cache_free(rds_conn_slab, conn); 305 306 rds_conn_count--; 307 } 308 EXPORT_SYMBOL_GPL(rds_conn_destroy); 309 310 static void rds_conn_message_info(struct socket *sock, unsigned int len, 311 struct rds_info_iterator *iter, 312 struct rds_info_lengths *lens, 313 int want_send) 314 { 315 struct hlist_head *head; 316 struct hlist_node *pos; 317 struct list_head *list; 318 struct rds_connection *conn; 319 struct rds_message *rm; 320 unsigned long flags; 321 unsigned int total = 0; 322 size_t i; 323 324 len /= sizeof(struct rds_info_message); 325 326 spin_lock_irqsave(&rds_conn_lock, flags); 327 328 for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash); 329 i++, head++) { 330 hlist_for_each_entry(conn, pos, head, c_hash_node) { 331 if (want_send) 332 list = &conn->c_send_queue; 333 else 334 list = &conn->c_retrans; 335 336 spin_lock(&conn->c_lock); 337 338 /* XXX too lazy to maintain counts.. */ 339 list_for_each_entry(rm, list, m_conn_item) { 340 total++; 341 if (total <= len) 342 rds_inc_info_copy(&rm->m_inc, iter, 343 conn->c_laddr, 344 conn->c_faddr, 0); 345 } 346 347 spin_unlock(&conn->c_lock); 348 } 349 } 350 351 spin_unlock_irqrestore(&rds_conn_lock, flags); 352 353 lens->nr = total; 354 lens->each = sizeof(struct rds_info_message); 355 } 356 357 static void rds_conn_message_info_send(struct socket *sock, unsigned int len, 358 struct rds_info_iterator *iter, 359 struct rds_info_lengths *lens) 360 { 361 rds_conn_message_info(sock, len, iter, lens, 1); 362 } 363 364 static void rds_conn_message_info_retrans(struct socket *sock, 365 unsigned int len, 366 struct rds_info_iterator *iter, 367 struct rds_info_lengths *lens) 368 { 369 rds_conn_message_info(sock, len, iter, lens, 0); 370 } 371 372 void rds_for_each_conn_info(struct socket *sock, unsigned int len, 373 struct rds_info_iterator *iter, 374 struct rds_info_lengths *lens, 375 int (*visitor)(struct rds_connection *, void *), 376 size_t item_len) 377 { 378 uint64_t buffer[(item_len + 7) / 8]; 379 struct hlist_head *head; 380 struct hlist_node *pos; 381 struct hlist_node *tmp; 382 struct rds_connection *conn; 383 unsigned long flags; 384 size_t i; 385 386 spin_lock_irqsave(&rds_conn_lock, flags); 387 388 lens->nr = 0; 389 lens->each = item_len; 390 391 for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash); 392 i++, head++) { 393 hlist_for_each_entry_safe(conn, pos, tmp, head, c_hash_node) { 394 395 /* XXX no c_lock usage.. */ 396 if (!visitor(conn, buffer)) 397 continue; 398 399 /* We copy as much as we can fit in the buffer, 400 * but we count all items so that the caller 401 * can resize the buffer. */ 402 if (len >= item_len) { 403 rds_info_copy(iter, buffer, item_len); 404 len -= item_len; 405 } 406 lens->nr++; 407 } 408 } 409 410 spin_unlock_irqrestore(&rds_conn_lock, flags); 411 } 412 EXPORT_SYMBOL_GPL(rds_for_each_conn_info); 413 414 static int rds_conn_info_visitor(struct rds_connection *conn, 415 void *buffer) 416 { 417 struct rds_info_connection *cinfo = buffer; 418 419 cinfo->next_tx_seq = conn->c_next_tx_seq; 420 cinfo->next_rx_seq = conn->c_next_rx_seq; 421 cinfo->laddr = conn->c_laddr; 422 cinfo->faddr = conn->c_faddr; 423 strncpy(cinfo->transport, conn->c_trans->t_name, 424 sizeof(cinfo->transport)); 425 cinfo->flags = 0; 426 427 rds_conn_info_set(cinfo->flags, 428 rds_conn_is_sending(conn), SENDING); 429 /* XXX Future: return the state rather than these funky bits */ 430 rds_conn_info_set(cinfo->flags, 431 atomic_read(&conn->c_state) == RDS_CONN_CONNECTING, 432 CONNECTING); 433 rds_conn_info_set(cinfo->flags, 434 atomic_read(&conn->c_state) == RDS_CONN_UP, 435 CONNECTED); 436 return 1; 437 } 438 439 static void rds_conn_info(struct socket *sock, unsigned int len, 440 struct rds_info_iterator *iter, 441 struct rds_info_lengths *lens) 442 { 443 rds_for_each_conn_info(sock, len, iter, lens, 444 rds_conn_info_visitor, 445 sizeof(struct rds_info_connection)); 446 } 447 448 int __init rds_conn_init(void) 449 { 450 rds_conn_slab = kmem_cache_create("rds_connection", 451 sizeof(struct rds_connection), 452 0, 0, NULL); 453 if (rds_conn_slab == NULL) 454 return -ENOMEM; 455 456 rds_info_register_func(RDS_INFO_CONNECTIONS, rds_conn_info); 457 rds_info_register_func(RDS_INFO_SEND_MESSAGES, 458 rds_conn_message_info_send); 459 rds_info_register_func(RDS_INFO_RETRANS_MESSAGES, 460 rds_conn_message_info_retrans); 461 462 return 0; 463 } 464 465 void rds_conn_exit(void) 466 { 467 rds_loop_exit(); 468 469 WARN_ON(!hlist_empty(rds_conn_hash)); 470 471 kmem_cache_destroy(rds_conn_slab); 472 473 rds_info_deregister_func(RDS_INFO_CONNECTIONS, rds_conn_info); 474 rds_info_deregister_func(RDS_INFO_SEND_MESSAGES, 475 rds_conn_message_info_send); 476 rds_info_deregister_func(RDS_INFO_RETRANS_MESSAGES, 477 rds_conn_message_info_retrans); 478 } 479 480 /* 481 * Force a disconnect 482 */ 483 void rds_conn_drop(struct rds_connection *conn) 484 { 485 atomic_set(&conn->c_state, RDS_CONN_ERROR); 486 queue_work(rds_wq, &conn->c_down_w); 487 } 488 EXPORT_SYMBOL_GPL(rds_conn_drop); 489 490 /* 491 * An error occurred on the connection 492 */ 493 void 494 __rds_conn_error(struct rds_connection *conn, const char *fmt, ...) 495 { 496 va_list ap; 497 498 va_start(ap, fmt); 499 vprintk(fmt, ap); 500 va_end(ap); 501 502 rds_conn_drop(conn); 503 } 504