1 // SPDX-License-Identifier: GPL-2.0-only 2 /****************************************************************************** 3 ******************************************************************************* 4 ** 5 ** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. 6 ** Copyright (C) 2004-2009 Red Hat, Inc. All rights reserved. 7 ** 8 ** 9 ******************************************************************************* 10 ******************************************************************************/ 11 12 /* 13 * lowcomms.c 14 * 15 * This is the "low-level" comms layer. 16 * 17 * It is responsible for sending/receiving messages 18 * from other nodes in the cluster. 19 * 20 * Cluster nodes are referred to by their nodeids. nodeids are 21 * simply 32 bit numbers to the locking module - if they need to 22 * be expanded for the cluster infrastructure then that is its 23 * responsibility. It is this layer's 24 * responsibility to resolve these into IP address or 25 * whatever it needs for inter-node communication. 26 * 27 * The comms level is two kernel threads that deal mainly with 28 * the receiving of messages from other nodes and passing them 29 * up to the mid-level comms layer (which understands the 30 * message format) for execution by the locking core, and 31 * a send thread which does all the setting up of connections 32 * to remote nodes and the sending of data. Threads are not allowed 33 * to send their own data because it may cause them to wait in times 34 * of high load. Also, this way, the sending thread can collect together 35 * messages bound for one node and send them in one block. 36 * 37 * lowcomms will choose to use either TCP or SCTP as its transport layer 38 * depending on the configuration variable 'protocol'. This should be set 39 * to 0 (default) for TCP or 1 for SCTP. It should be configured using a 40 * cluster-wide mechanism as it must be the same on all nodes of the cluster 41 * for the DLM to function. 42 * 43 */ 44 45 #include <asm/ioctls.h> 46 #include <net/sock.h> 47 #include <net/tcp.h> 48 #include <linux/pagemap.h> 49 #include <linux/file.h> 50 #include <linux/mutex.h> 51 #include <linux/sctp.h> 52 #include <linux/slab.h> 53 #include <net/sctp/sctp.h> 54 #include <net/ipv6.h> 55 56 #include "dlm_internal.h" 57 #include "lowcomms.h" 58 #include "midcomms.h" 59 #include "config.h" 60 61 #define NEEDED_RMEM (4*1024*1024) 62 #define CONN_HASH_SIZE 32 63 64 /* Number of messages to send before rescheduling */ 65 #define MAX_SEND_MSG_COUNT 25 66 #define DLM_SHUTDOWN_WAIT_TIMEOUT msecs_to_jiffies(10000) 67 68 struct connection { 69 struct socket *sock; /* NULL if not connected */ 70 uint32_t nodeid; /* So we know who we are in the list */ 71 struct mutex sock_mutex; 72 unsigned long flags; 73 #define CF_READ_PENDING 1 74 #define CF_WRITE_PENDING 2 75 #define CF_INIT_PENDING 4 76 #define CF_IS_OTHERCON 5 77 #define CF_CLOSE 6 78 #define CF_APP_LIMITED 7 79 #define CF_CLOSING 8 80 #define CF_SHUTDOWN 9 81 #define CF_CONNECTED 10 82 struct list_head writequeue; /* List of outgoing writequeue_entries */ 83 spinlock_t writequeue_lock; 84 void (*connect_action) (struct connection *); /* What to do to connect */ 85 void (*shutdown_action)(struct connection *con); /* What to do to shutdown */ 86 int retries; 87 #define MAX_CONNECT_RETRIES 3 88 struct hlist_node list; 89 struct connection *othercon; 90 struct work_struct rwork; /* Receive workqueue */ 91 struct work_struct swork; /* Send workqueue */ 92 wait_queue_head_t shutdown_wait; /* wait for graceful shutdown */ 93 unsigned char *rx_buf; 94 int rx_buflen; 95 int rx_leftover; 96 struct rcu_head rcu; 97 }; 98 #define sock2con(x) ((struct connection *)(x)->sk_user_data) 99 100 struct listen_connection { 101 struct socket *sock; 102 struct work_struct rwork; 103 }; 104 105 /* An entry waiting to be sent */ 106 struct writequeue_entry { 107 struct list_head list; 108 struct page *page; 109 int offset; 110 int len; 111 int end; 112 int users; 113 struct connection *con; 114 }; 115 116 struct dlm_node_addr { 117 struct list_head list; 118 int nodeid; 119 int addr_count; 120 int curr_addr_index; 121 struct sockaddr_storage *addr[DLM_MAX_ADDR_COUNT]; 122 }; 123 124 static struct listen_sock_callbacks { 125 void (*sk_error_report)(struct sock *); 126 void (*sk_data_ready)(struct sock *); 127 void (*sk_state_change)(struct sock *); 128 void (*sk_write_space)(struct sock *); 129 } listen_sock; 130 131 static LIST_HEAD(dlm_node_addrs); 132 static DEFINE_SPINLOCK(dlm_node_addrs_spin); 133 134 static struct listen_connection listen_con; 135 static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT]; 136 static int dlm_local_count; 137 static int dlm_allow_conn; 138 139 /* Work queues */ 140 static struct workqueue_struct *recv_workqueue; 141 static struct workqueue_struct *send_workqueue; 142 143 static struct hlist_head connection_hash[CONN_HASH_SIZE]; 144 static DEFINE_SPINLOCK(connections_lock); 145 DEFINE_STATIC_SRCU(connections_srcu); 146 147 static void process_recv_sockets(struct work_struct *work); 148 static void process_send_sockets(struct work_struct *work); 149 150 static void sctp_connect_to_sock(struct connection *con); 151 static void tcp_connect_to_sock(struct connection *con); 152 static void dlm_tcp_shutdown(struct connection *con); 153 154 /* This is deliberately very simple because most clusters have simple 155 sequential nodeids, so we should be able to go straight to a connection 156 struct in the array */ 157 static inline int nodeid_hash(int nodeid) 158 { 159 return nodeid & (CONN_HASH_SIZE-1); 160 } 161 162 static struct connection *__find_con(int nodeid) 163 { 164 int r, idx; 165 struct connection *con; 166 167 r = nodeid_hash(nodeid); 168 169 idx = srcu_read_lock(&connections_srcu); 170 hlist_for_each_entry_rcu(con, &connection_hash[r], list) { 171 if (con->nodeid == nodeid) { 172 srcu_read_unlock(&connections_srcu, idx); 173 return con; 174 } 175 } 176 srcu_read_unlock(&connections_srcu, idx); 177 178 return NULL; 179 } 180 181 static int dlm_con_init(struct connection *con, int nodeid) 182 { 183 con->rx_buflen = dlm_config.ci_buffer_size; 184 con->rx_buf = kmalloc(con->rx_buflen, GFP_NOFS); 185 if (!con->rx_buf) 186 return -ENOMEM; 187 188 con->nodeid = nodeid; 189 mutex_init(&con->sock_mutex); 190 INIT_LIST_HEAD(&con->writequeue); 191 spin_lock_init(&con->writequeue_lock); 192 INIT_WORK(&con->swork, process_send_sockets); 193 INIT_WORK(&con->rwork, process_recv_sockets); 194 init_waitqueue_head(&con->shutdown_wait); 195 196 if (dlm_config.ci_protocol == 0) { 197 con->connect_action = tcp_connect_to_sock; 198 con->shutdown_action = dlm_tcp_shutdown; 199 } else { 200 con->connect_action = sctp_connect_to_sock; 201 } 202 203 return 0; 204 } 205 206 /* 207 * If 'allocation' is zero then we don't attempt to create a new 208 * connection structure for this node. 209 */ 210 static struct connection *nodeid2con(int nodeid, gfp_t alloc) 211 { 212 struct connection *con, *tmp; 213 int r, ret; 214 215 con = __find_con(nodeid); 216 if (con || !alloc) 217 return con; 218 219 con = kzalloc(sizeof(*con), alloc); 220 if (!con) 221 return NULL; 222 223 ret = dlm_con_init(con, nodeid); 224 if (ret) { 225 kfree(con); 226 return NULL; 227 } 228 229 r = nodeid_hash(nodeid); 230 231 spin_lock(&connections_lock); 232 /* Because multiple workqueues/threads calls this function it can 233 * race on multiple cpu's. Instead of locking hot path __find_con() 234 * we just check in rare cases of recently added nodes again 235 * under protection of connections_lock. If this is the case we 236 * abort our connection creation and return the existing connection. 237 */ 238 tmp = __find_con(nodeid); 239 if (tmp) { 240 spin_unlock(&connections_lock); 241 kfree(con->rx_buf); 242 kfree(con); 243 return tmp; 244 } 245 246 hlist_add_head_rcu(&con->list, &connection_hash[r]); 247 spin_unlock(&connections_lock); 248 249 return con; 250 } 251 252 /* Loop round all connections */ 253 static void foreach_conn(void (*conn_func)(struct connection *c)) 254 { 255 int i, idx; 256 struct connection *con; 257 258 idx = srcu_read_lock(&connections_srcu); 259 for (i = 0; i < CONN_HASH_SIZE; i++) { 260 hlist_for_each_entry_rcu(con, &connection_hash[i], list) 261 conn_func(con); 262 } 263 srcu_read_unlock(&connections_srcu, idx); 264 } 265 266 static struct dlm_node_addr *find_node_addr(int nodeid) 267 { 268 struct dlm_node_addr *na; 269 270 list_for_each_entry(na, &dlm_node_addrs, list) { 271 if (na->nodeid == nodeid) 272 return na; 273 } 274 return NULL; 275 } 276 277 static int addr_compare(struct sockaddr_storage *x, struct sockaddr_storage *y) 278 { 279 switch (x->ss_family) { 280 case AF_INET: { 281 struct sockaddr_in *sinx = (struct sockaddr_in *)x; 282 struct sockaddr_in *siny = (struct sockaddr_in *)y; 283 if (sinx->sin_addr.s_addr != siny->sin_addr.s_addr) 284 return 0; 285 if (sinx->sin_port != siny->sin_port) 286 return 0; 287 break; 288 } 289 case AF_INET6: { 290 struct sockaddr_in6 *sinx = (struct sockaddr_in6 *)x; 291 struct sockaddr_in6 *siny = (struct sockaddr_in6 *)y; 292 if (!ipv6_addr_equal(&sinx->sin6_addr, &siny->sin6_addr)) 293 return 0; 294 if (sinx->sin6_port != siny->sin6_port) 295 return 0; 296 break; 297 } 298 default: 299 return 0; 300 } 301 return 1; 302 } 303 304 static int nodeid_to_addr(int nodeid, struct sockaddr_storage *sas_out, 305 struct sockaddr *sa_out, bool try_new_addr) 306 { 307 struct sockaddr_storage sas; 308 struct dlm_node_addr *na; 309 310 if (!dlm_local_count) 311 return -1; 312 313 spin_lock(&dlm_node_addrs_spin); 314 na = find_node_addr(nodeid); 315 if (na && na->addr_count) { 316 memcpy(&sas, na->addr[na->curr_addr_index], 317 sizeof(struct sockaddr_storage)); 318 319 if (try_new_addr) { 320 na->curr_addr_index++; 321 if (na->curr_addr_index == na->addr_count) 322 na->curr_addr_index = 0; 323 } 324 } 325 spin_unlock(&dlm_node_addrs_spin); 326 327 if (!na) 328 return -EEXIST; 329 330 if (!na->addr_count) 331 return -ENOENT; 332 333 if (sas_out) 334 memcpy(sas_out, &sas, sizeof(struct sockaddr_storage)); 335 336 if (!sa_out) 337 return 0; 338 339 if (dlm_local_addr[0]->ss_family == AF_INET) { 340 struct sockaddr_in *in4 = (struct sockaddr_in *) &sas; 341 struct sockaddr_in *ret4 = (struct sockaddr_in *) sa_out; 342 ret4->sin_addr.s_addr = in4->sin_addr.s_addr; 343 } else { 344 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) &sas; 345 struct sockaddr_in6 *ret6 = (struct sockaddr_in6 *) sa_out; 346 ret6->sin6_addr = in6->sin6_addr; 347 } 348 349 return 0; 350 } 351 352 static int addr_to_nodeid(struct sockaddr_storage *addr, int *nodeid) 353 { 354 struct dlm_node_addr *na; 355 int rv = -EEXIST; 356 int addr_i; 357 358 spin_lock(&dlm_node_addrs_spin); 359 list_for_each_entry(na, &dlm_node_addrs, list) { 360 if (!na->addr_count) 361 continue; 362 363 for (addr_i = 0; addr_i < na->addr_count; addr_i++) { 364 if (addr_compare(na->addr[addr_i], addr)) { 365 *nodeid = na->nodeid; 366 rv = 0; 367 goto unlock; 368 } 369 } 370 } 371 unlock: 372 spin_unlock(&dlm_node_addrs_spin); 373 return rv; 374 } 375 376 int dlm_lowcomms_addr(int nodeid, struct sockaddr_storage *addr, int len) 377 { 378 struct sockaddr_storage *new_addr; 379 struct dlm_node_addr *new_node, *na; 380 381 new_node = kzalloc(sizeof(struct dlm_node_addr), GFP_NOFS); 382 if (!new_node) 383 return -ENOMEM; 384 385 new_addr = kzalloc(sizeof(struct sockaddr_storage), GFP_NOFS); 386 if (!new_addr) { 387 kfree(new_node); 388 return -ENOMEM; 389 } 390 391 memcpy(new_addr, addr, len); 392 393 spin_lock(&dlm_node_addrs_spin); 394 na = find_node_addr(nodeid); 395 if (!na) { 396 new_node->nodeid = nodeid; 397 new_node->addr[0] = new_addr; 398 new_node->addr_count = 1; 399 list_add(&new_node->list, &dlm_node_addrs); 400 spin_unlock(&dlm_node_addrs_spin); 401 return 0; 402 } 403 404 if (na->addr_count >= DLM_MAX_ADDR_COUNT) { 405 spin_unlock(&dlm_node_addrs_spin); 406 kfree(new_addr); 407 kfree(new_node); 408 return -ENOSPC; 409 } 410 411 na->addr[na->addr_count++] = new_addr; 412 spin_unlock(&dlm_node_addrs_spin); 413 kfree(new_node); 414 return 0; 415 } 416 417 /* Data available on socket or listen socket received a connect */ 418 static void lowcomms_data_ready(struct sock *sk) 419 { 420 struct connection *con; 421 422 read_lock_bh(&sk->sk_callback_lock); 423 con = sock2con(sk); 424 if (con && !test_and_set_bit(CF_READ_PENDING, &con->flags)) 425 queue_work(recv_workqueue, &con->rwork); 426 read_unlock_bh(&sk->sk_callback_lock); 427 } 428 429 static void lowcomms_listen_data_ready(struct sock *sk) 430 { 431 queue_work(recv_workqueue, &listen_con.rwork); 432 } 433 434 static void lowcomms_write_space(struct sock *sk) 435 { 436 struct connection *con; 437 438 read_lock_bh(&sk->sk_callback_lock); 439 con = sock2con(sk); 440 if (!con) 441 goto out; 442 443 if (!test_and_set_bit(CF_CONNECTED, &con->flags)) { 444 log_print("successful connected to node %d", con->nodeid); 445 queue_work(send_workqueue, &con->swork); 446 goto out; 447 } 448 449 clear_bit(SOCK_NOSPACE, &con->sock->flags); 450 451 if (test_and_clear_bit(CF_APP_LIMITED, &con->flags)) { 452 con->sock->sk->sk_write_pending--; 453 clear_bit(SOCKWQ_ASYNC_NOSPACE, &con->sock->flags); 454 } 455 456 queue_work(send_workqueue, &con->swork); 457 out: 458 read_unlock_bh(&sk->sk_callback_lock); 459 } 460 461 static inline void lowcomms_connect_sock(struct connection *con) 462 { 463 if (test_bit(CF_CLOSE, &con->flags)) 464 return; 465 queue_work(send_workqueue, &con->swork); 466 cond_resched(); 467 } 468 469 static void lowcomms_state_change(struct sock *sk) 470 { 471 /* SCTP layer is not calling sk_data_ready when the connection 472 * is done, so we catch the signal through here. Also, it 473 * doesn't switch socket state when entering shutdown, so we 474 * skip the write in that case. 475 */ 476 if (sk->sk_shutdown) { 477 if (sk->sk_shutdown == RCV_SHUTDOWN) 478 lowcomms_data_ready(sk); 479 } else if (sk->sk_state == TCP_ESTABLISHED) { 480 lowcomms_write_space(sk); 481 } 482 } 483 484 int dlm_lowcomms_connect_node(int nodeid) 485 { 486 struct connection *con; 487 488 if (nodeid == dlm_our_nodeid()) 489 return 0; 490 491 con = nodeid2con(nodeid, GFP_NOFS); 492 if (!con) 493 return -ENOMEM; 494 lowcomms_connect_sock(con); 495 return 0; 496 } 497 498 static void lowcomms_error_report(struct sock *sk) 499 { 500 struct connection *con; 501 struct sockaddr_storage saddr; 502 void (*orig_report)(struct sock *) = NULL; 503 504 read_lock_bh(&sk->sk_callback_lock); 505 con = sock2con(sk); 506 if (con == NULL) 507 goto out; 508 509 orig_report = listen_sock.sk_error_report; 510 if (con->sock == NULL || 511 kernel_getpeername(con->sock, (struct sockaddr *)&saddr) < 0) { 512 printk_ratelimited(KERN_ERR "dlm: node %d: socket error " 513 "sending to node %d, port %d, " 514 "sk_err=%d/%d\n", dlm_our_nodeid(), 515 con->nodeid, dlm_config.ci_tcp_port, 516 sk->sk_err, sk->sk_err_soft); 517 } else if (saddr.ss_family == AF_INET) { 518 struct sockaddr_in *sin4 = (struct sockaddr_in *)&saddr; 519 520 printk_ratelimited(KERN_ERR "dlm: node %d: socket error " 521 "sending to node %d at %pI4, port %d, " 522 "sk_err=%d/%d\n", dlm_our_nodeid(), 523 con->nodeid, &sin4->sin_addr.s_addr, 524 dlm_config.ci_tcp_port, sk->sk_err, 525 sk->sk_err_soft); 526 } else { 527 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&saddr; 528 529 printk_ratelimited(KERN_ERR "dlm: node %d: socket error " 530 "sending to node %d at %u.%u.%u.%u, " 531 "port %d, sk_err=%d/%d\n", dlm_our_nodeid(), 532 con->nodeid, sin6->sin6_addr.s6_addr32[0], 533 sin6->sin6_addr.s6_addr32[1], 534 sin6->sin6_addr.s6_addr32[2], 535 sin6->sin6_addr.s6_addr32[3], 536 dlm_config.ci_tcp_port, sk->sk_err, 537 sk->sk_err_soft); 538 } 539 out: 540 read_unlock_bh(&sk->sk_callback_lock); 541 if (orig_report) 542 orig_report(sk); 543 } 544 545 /* Note: sk_callback_lock must be locked before calling this function. */ 546 static void save_listen_callbacks(struct socket *sock) 547 { 548 struct sock *sk = sock->sk; 549 550 listen_sock.sk_data_ready = sk->sk_data_ready; 551 listen_sock.sk_state_change = sk->sk_state_change; 552 listen_sock.sk_write_space = sk->sk_write_space; 553 listen_sock.sk_error_report = sk->sk_error_report; 554 } 555 556 static void restore_callbacks(struct socket *sock) 557 { 558 struct sock *sk = sock->sk; 559 560 write_lock_bh(&sk->sk_callback_lock); 561 sk->sk_user_data = NULL; 562 sk->sk_data_ready = listen_sock.sk_data_ready; 563 sk->sk_state_change = listen_sock.sk_state_change; 564 sk->sk_write_space = listen_sock.sk_write_space; 565 sk->sk_error_report = listen_sock.sk_error_report; 566 write_unlock_bh(&sk->sk_callback_lock); 567 } 568 569 static void add_listen_sock(struct socket *sock, struct listen_connection *con) 570 { 571 struct sock *sk = sock->sk; 572 573 write_lock_bh(&sk->sk_callback_lock); 574 save_listen_callbacks(sock); 575 con->sock = sock; 576 577 sk->sk_user_data = con; 578 sk->sk_allocation = GFP_NOFS; 579 /* Install a data_ready callback */ 580 sk->sk_data_ready = lowcomms_listen_data_ready; 581 write_unlock_bh(&sk->sk_callback_lock); 582 } 583 584 /* Make a socket active */ 585 static void add_sock(struct socket *sock, struct connection *con) 586 { 587 struct sock *sk = sock->sk; 588 589 write_lock_bh(&sk->sk_callback_lock); 590 con->sock = sock; 591 592 sk->sk_user_data = con; 593 /* Install a data_ready callback */ 594 sk->sk_data_ready = lowcomms_data_ready; 595 sk->sk_write_space = lowcomms_write_space; 596 sk->sk_state_change = lowcomms_state_change; 597 sk->sk_allocation = GFP_NOFS; 598 sk->sk_error_report = lowcomms_error_report; 599 write_unlock_bh(&sk->sk_callback_lock); 600 } 601 602 /* Add the port number to an IPv6 or 4 sockaddr and return the address 603 length */ 604 static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port, 605 int *addr_len) 606 { 607 saddr->ss_family = dlm_local_addr[0]->ss_family; 608 if (saddr->ss_family == AF_INET) { 609 struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr; 610 in4_addr->sin_port = cpu_to_be16(port); 611 *addr_len = sizeof(struct sockaddr_in); 612 memset(&in4_addr->sin_zero, 0, sizeof(in4_addr->sin_zero)); 613 } else { 614 struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr; 615 in6_addr->sin6_port = cpu_to_be16(port); 616 *addr_len = sizeof(struct sockaddr_in6); 617 } 618 memset((char *)saddr + *addr_len, 0, sizeof(struct sockaddr_storage) - *addr_len); 619 } 620 621 static void dlm_close_sock(struct socket **sock) 622 { 623 if (*sock) { 624 restore_callbacks(*sock); 625 sock_release(*sock); 626 *sock = NULL; 627 } 628 } 629 630 /* Close a remote connection and tidy up */ 631 static void close_connection(struct connection *con, bool and_other, 632 bool tx, bool rx) 633 { 634 bool closing = test_and_set_bit(CF_CLOSING, &con->flags); 635 636 if (tx && !closing && cancel_work_sync(&con->swork)) { 637 log_print("canceled swork for node %d", con->nodeid); 638 clear_bit(CF_WRITE_PENDING, &con->flags); 639 } 640 if (rx && !closing && cancel_work_sync(&con->rwork)) { 641 log_print("canceled rwork for node %d", con->nodeid); 642 clear_bit(CF_READ_PENDING, &con->flags); 643 } 644 645 mutex_lock(&con->sock_mutex); 646 dlm_close_sock(&con->sock); 647 648 if (con->othercon && and_other) { 649 /* Will only re-enter once. */ 650 close_connection(con->othercon, false, true, true); 651 } 652 653 con->rx_leftover = 0; 654 con->retries = 0; 655 clear_bit(CF_CONNECTED, &con->flags); 656 mutex_unlock(&con->sock_mutex); 657 clear_bit(CF_CLOSING, &con->flags); 658 } 659 660 static void shutdown_connection(struct connection *con) 661 { 662 int ret; 663 664 if (cancel_work_sync(&con->swork)) { 665 log_print("canceled swork for node %d", con->nodeid); 666 clear_bit(CF_WRITE_PENDING, &con->flags); 667 } 668 669 mutex_lock(&con->sock_mutex); 670 /* nothing to shutdown */ 671 if (!con->sock) { 672 mutex_unlock(&con->sock_mutex); 673 return; 674 } 675 676 set_bit(CF_SHUTDOWN, &con->flags); 677 ret = kernel_sock_shutdown(con->sock, SHUT_WR); 678 mutex_unlock(&con->sock_mutex); 679 if (ret) { 680 log_print("Connection %p failed to shutdown: %d will force close", 681 con, ret); 682 goto force_close; 683 } else { 684 ret = wait_event_timeout(con->shutdown_wait, 685 !test_bit(CF_SHUTDOWN, &con->flags), 686 DLM_SHUTDOWN_WAIT_TIMEOUT); 687 if (ret == 0) { 688 log_print("Connection %p shutdown timed out, will force close", 689 con); 690 goto force_close; 691 } 692 } 693 694 return; 695 696 force_close: 697 clear_bit(CF_SHUTDOWN, &con->flags); 698 close_connection(con, false, true, true); 699 } 700 701 static void dlm_tcp_shutdown(struct connection *con) 702 { 703 if (con->othercon) 704 shutdown_connection(con->othercon); 705 shutdown_connection(con); 706 } 707 708 static int con_realloc_receive_buf(struct connection *con, int newlen) 709 { 710 unsigned char *newbuf; 711 712 newbuf = kmalloc(newlen, GFP_NOFS); 713 if (!newbuf) 714 return -ENOMEM; 715 716 /* copy any leftover from last receive */ 717 if (con->rx_leftover) 718 memmove(newbuf, con->rx_buf, con->rx_leftover); 719 720 /* swap to new buffer space */ 721 kfree(con->rx_buf); 722 con->rx_buflen = newlen; 723 con->rx_buf = newbuf; 724 725 return 0; 726 } 727 728 /* Data received from remote end */ 729 static int receive_from_sock(struct connection *con) 730 { 731 int call_again_soon = 0; 732 struct msghdr msg; 733 struct kvec iov; 734 int ret, buflen; 735 736 mutex_lock(&con->sock_mutex); 737 738 if (con->sock == NULL) { 739 ret = -EAGAIN; 740 goto out_close; 741 } 742 743 /* realloc if we get new buffer size to read out */ 744 buflen = dlm_config.ci_buffer_size; 745 if (con->rx_buflen != buflen && con->rx_leftover <= buflen) { 746 ret = con_realloc_receive_buf(con, buflen); 747 if (ret < 0) 748 goto out_resched; 749 } 750 751 /* calculate new buffer parameter regarding last receive and 752 * possible leftover bytes 753 */ 754 iov.iov_base = con->rx_buf + con->rx_leftover; 755 iov.iov_len = con->rx_buflen - con->rx_leftover; 756 757 memset(&msg, 0, sizeof(msg)); 758 msg.msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL; 759 ret = kernel_recvmsg(con->sock, &msg, &iov, 1, iov.iov_len, 760 msg.msg_flags); 761 if (ret <= 0) 762 goto out_close; 763 else if (ret == iov.iov_len) 764 call_again_soon = 1; 765 766 /* new buflen according readed bytes and leftover from last receive */ 767 buflen = ret + con->rx_leftover; 768 ret = dlm_process_incoming_buffer(con->nodeid, con->rx_buf, buflen); 769 if (ret < 0) 770 goto out_close; 771 772 /* calculate leftover bytes from process and put it into begin of 773 * the receive buffer, so next receive we have the full message 774 * at the start address of the receive buffer. 775 */ 776 con->rx_leftover = buflen - ret; 777 if (con->rx_leftover) { 778 memmove(con->rx_buf, con->rx_buf + ret, 779 con->rx_leftover); 780 call_again_soon = true; 781 } 782 783 if (call_again_soon) 784 goto out_resched; 785 786 mutex_unlock(&con->sock_mutex); 787 return 0; 788 789 out_resched: 790 if (!test_and_set_bit(CF_READ_PENDING, &con->flags)) 791 queue_work(recv_workqueue, &con->rwork); 792 mutex_unlock(&con->sock_mutex); 793 return -EAGAIN; 794 795 out_close: 796 mutex_unlock(&con->sock_mutex); 797 if (ret != -EAGAIN) { 798 /* Reconnect when there is something to send */ 799 close_connection(con, false, true, false); 800 if (ret == 0) { 801 log_print("connection %p got EOF from %d", 802 con, con->nodeid); 803 /* handling for tcp shutdown */ 804 clear_bit(CF_SHUTDOWN, &con->flags); 805 wake_up(&con->shutdown_wait); 806 /* signal to breaking receive worker */ 807 ret = -1; 808 } 809 } 810 return ret; 811 } 812 813 /* Listening socket is busy, accept a connection */ 814 static int accept_from_sock(struct listen_connection *con) 815 { 816 int result; 817 struct sockaddr_storage peeraddr; 818 struct socket *newsock; 819 int len; 820 int nodeid; 821 struct connection *newcon; 822 struct connection *addcon; 823 unsigned int mark; 824 825 if (!dlm_allow_conn) { 826 return -1; 827 } 828 829 if (!con->sock) 830 return -ENOTCONN; 831 832 result = kernel_accept(con->sock, &newsock, O_NONBLOCK); 833 if (result < 0) 834 goto accept_err; 835 836 /* Get the connected socket's peer */ 837 memset(&peeraddr, 0, sizeof(peeraddr)); 838 len = newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr, 2); 839 if (len < 0) { 840 result = -ECONNABORTED; 841 goto accept_err; 842 } 843 844 /* Get the new node's NODEID */ 845 make_sockaddr(&peeraddr, 0, &len); 846 if (addr_to_nodeid(&peeraddr, &nodeid)) { 847 unsigned char *b=(unsigned char *)&peeraddr; 848 log_print("connect from non cluster node"); 849 print_hex_dump_bytes("ss: ", DUMP_PREFIX_NONE, 850 b, sizeof(struct sockaddr_storage)); 851 sock_release(newsock); 852 return -1; 853 } 854 855 dlm_comm_mark(nodeid, &mark); 856 sock_set_mark(newsock->sk, mark); 857 858 log_print("got connection from %d", nodeid); 859 860 /* Check to see if we already have a connection to this node. This 861 * could happen if the two nodes initiate a connection at roughly 862 * the same time and the connections cross on the wire. 863 * In this case we store the incoming one in "othercon" 864 */ 865 newcon = nodeid2con(nodeid, GFP_NOFS); 866 if (!newcon) { 867 result = -ENOMEM; 868 goto accept_err; 869 } 870 871 mutex_lock(&newcon->sock_mutex); 872 if (newcon->sock) { 873 struct connection *othercon = newcon->othercon; 874 875 if (!othercon) { 876 othercon = kzalloc(sizeof(*othercon), GFP_NOFS); 877 if (!othercon) { 878 log_print("failed to allocate incoming socket"); 879 mutex_unlock(&newcon->sock_mutex); 880 result = -ENOMEM; 881 goto accept_err; 882 } 883 884 result = dlm_con_init(othercon, nodeid); 885 if (result < 0) { 886 kfree(othercon); 887 goto accept_err; 888 } 889 890 newcon->othercon = othercon; 891 } else { 892 /* close other sock con if we have something new */ 893 close_connection(othercon, false, true, false); 894 } 895 896 mutex_lock_nested(&othercon->sock_mutex, 1); 897 add_sock(newsock, othercon); 898 addcon = othercon; 899 mutex_unlock(&othercon->sock_mutex); 900 } 901 else { 902 /* accept copies the sk after we've saved the callbacks, so we 903 don't want to save them a second time or comm errors will 904 result in calling sk_error_report recursively. */ 905 add_sock(newsock, newcon); 906 addcon = newcon; 907 } 908 909 mutex_unlock(&newcon->sock_mutex); 910 911 /* 912 * Add it to the active queue in case we got data 913 * between processing the accept adding the socket 914 * to the read_sockets list 915 */ 916 if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags)) 917 queue_work(recv_workqueue, &addcon->rwork); 918 919 return 0; 920 921 accept_err: 922 if (newsock) 923 sock_release(newsock); 924 925 if (result != -EAGAIN) 926 log_print("error accepting connection from node: %d", result); 927 return result; 928 } 929 930 static void free_entry(struct writequeue_entry *e) 931 { 932 __free_page(e->page); 933 kfree(e); 934 } 935 936 /* 937 * writequeue_entry_complete - try to delete and free write queue entry 938 * @e: write queue entry to try to delete 939 * @completed: bytes completed 940 * 941 * writequeue_lock must be held. 942 */ 943 static void writequeue_entry_complete(struct writequeue_entry *e, int completed) 944 { 945 e->offset += completed; 946 e->len -= completed; 947 948 if (e->len == 0 && e->users == 0) { 949 list_del(&e->list); 950 free_entry(e); 951 } 952 } 953 954 /* 955 * sctp_bind_addrs - bind a SCTP socket to all our addresses 956 */ 957 static int sctp_bind_addrs(struct socket *sock, uint16_t port) 958 { 959 struct sockaddr_storage localaddr; 960 struct sockaddr *addr = (struct sockaddr *)&localaddr; 961 int i, addr_len, result = 0; 962 963 for (i = 0; i < dlm_local_count; i++) { 964 memcpy(&localaddr, dlm_local_addr[i], sizeof(localaddr)); 965 make_sockaddr(&localaddr, port, &addr_len); 966 967 if (!i) 968 result = kernel_bind(sock, addr, addr_len); 969 else 970 result = sock_bind_add(sock->sk, addr, addr_len); 971 972 if (result < 0) { 973 log_print("Can't bind to %d addr number %d, %d.\n", 974 port, i + 1, result); 975 break; 976 } 977 } 978 return result; 979 } 980 981 /* Initiate an SCTP association. 982 This is a special case of send_to_sock() in that we don't yet have a 983 peeled-off socket for this association, so we use the listening socket 984 and add the primary IP address of the remote node. 985 */ 986 static void sctp_connect_to_sock(struct connection *con) 987 { 988 struct sockaddr_storage daddr; 989 int result; 990 int addr_len; 991 struct socket *sock; 992 unsigned int mark; 993 994 dlm_comm_mark(con->nodeid, &mark); 995 996 mutex_lock(&con->sock_mutex); 997 998 /* Some odd races can cause double-connects, ignore them */ 999 if (con->retries++ > MAX_CONNECT_RETRIES) 1000 goto out; 1001 1002 if (con->sock) { 1003 log_print("node %d already connected.", con->nodeid); 1004 goto out; 1005 } 1006 1007 memset(&daddr, 0, sizeof(daddr)); 1008 result = nodeid_to_addr(con->nodeid, &daddr, NULL, true); 1009 if (result < 0) { 1010 log_print("no address for nodeid %d", con->nodeid); 1011 goto out; 1012 } 1013 1014 /* Create a socket to communicate with */ 1015 result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family, 1016 SOCK_STREAM, IPPROTO_SCTP, &sock); 1017 if (result < 0) 1018 goto socket_err; 1019 1020 sock_set_mark(sock->sk, mark); 1021 1022 add_sock(sock, con); 1023 1024 /* Bind to all addresses. */ 1025 if (sctp_bind_addrs(con->sock, 0)) 1026 goto bind_err; 1027 1028 make_sockaddr(&daddr, dlm_config.ci_tcp_port, &addr_len); 1029 1030 log_print("connecting to %d", con->nodeid); 1031 1032 /* Turn off Nagle's algorithm */ 1033 sctp_sock_set_nodelay(sock->sk); 1034 1035 /* 1036 * Make sock->ops->connect() function return in specified time, 1037 * since O_NONBLOCK argument in connect() function does not work here, 1038 * then, we should restore the default value of this attribute. 1039 */ 1040 sock_set_sndtimeo(sock->sk, 5); 1041 result = sock->ops->connect(sock, (struct sockaddr *)&daddr, addr_len, 1042 0); 1043 sock_set_sndtimeo(sock->sk, 0); 1044 1045 if (result == -EINPROGRESS) 1046 result = 0; 1047 if (result == 0) { 1048 if (!test_and_set_bit(CF_CONNECTED, &con->flags)) 1049 log_print("successful connected to node %d", con->nodeid); 1050 goto out; 1051 } 1052 1053 bind_err: 1054 con->sock = NULL; 1055 sock_release(sock); 1056 1057 socket_err: 1058 /* 1059 * Some errors are fatal and this list might need adjusting. For other 1060 * errors we try again until the max number of retries is reached. 1061 */ 1062 if (result != -EHOSTUNREACH && 1063 result != -ENETUNREACH && 1064 result != -ENETDOWN && 1065 result != -EINVAL && 1066 result != -EPROTONOSUPPORT) { 1067 log_print("connect %d try %d error %d", con->nodeid, 1068 con->retries, result); 1069 mutex_unlock(&con->sock_mutex); 1070 msleep(1000); 1071 lowcomms_connect_sock(con); 1072 return; 1073 } 1074 1075 out: 1076 mutex_unlock(&con->sock_mutex); 1077 } 1078 1079 /* Connect a new socket to its peer */ 1080 static void tcp_connect_to_sock(struct connection *con) 1081 { 1082 struct sockaddr_storage saddr, src_addr; 1083 int addr_len; 1084 struct socket *sock = NULL; 1085 unsigned int mark; 1086 int result; 1087 1088 dlm_comm_mark(con->nodeid, &mark); 1089 1090 mutex_lock(&con->sock_mutex); 1091 if (con->retries++ > MAX_CONNECT_RETRIES) 1092 goto out; 1093 1094 /* Some odd races can cause double-connects, ignore them */ 1095 if (con->sock) 1096 goto out; 1097 1098 /* Create a socket to communicate with */ 1099 result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family, 1100 SOCK_STREAM, IPPROTO_TCP, &sock); 1101 if (result < 0) 1102 goto out_err; 1103 1104 sock_set_mark(sock->sk, mark); 1105 1106 memset(&saddr, 0, sizeof(saddr)); 1107 result = nodeid_to_addr(con->nodeid, &saddr, NULL, false); 1108 if (result < 0) { 1109 log_print("no address for nodeid %d", con->nodeid); 1110 goto out_err; 1111 } 1112 1113 add_sock(sock, con); 1114 1115 /* Bind to our cluster-known address connecting to avoid 1116 routing problems */ 1117 memcpy(&src_addr, dlm_local_addr[0], sizeof(src_addr)); 1118 make_sockaddr(&src_addr, 0, &addr_len); 1119 result = sock->ops->bind(sock, (struct sockaddr *) &src_addr, 1120 addr_len); 1121 if (result < 0) { 1122 log_print("could not bind for connect: %d", result); 1123 /* This *may* not indicate a critical error */ 1124 } 1125 1126 make_sockaddr(&saddr, dlm_config.ci_tcp_port, &addr_len); 1127 1128 log_print("connecting to %d", con->nodeid); 1129 1130 /* Turn off Nagle's algorithm */ 1131 tcp_sock_set_nodelay(sock->sk); 1132 1133 result = sock->ops->connect(sock, (struct sockaddr *)&saddr, addr_len, 1134 O_NONBLOCK); 1135 if (result == -EINPROGRESS) 1136 result = 0; 1137 if (result == 0) 1138 goto out; 1139 1140 out_err: 1141 if (con->sock) { 1142 sock_release(con->sock); 1143 con->sock = NULL; 1144 } else if (sock) { 1145 sock_release(sock); 1146 } 1147 /* 1148 * Some errors are fatal and this list might need adjusting. For other 1149 * errors we try again until the max number of retries is reached. 1150 */ 1151 if (result != -EHOSTUNREACH && 1152 result != -ENETUNREACH && 1153 result != -ENETDOWN && 1154 result != -EINVAL && 1155 result != -EPROTONOSUPPORT) { 1156 log_print("connect %d try %d error %d", con->nodeid, 1157 con->retries, result); 1158 mutex_unlock(&con->sock_mutex); 1159 msleep(1000); 1160 lowcomms_connect_sock(con); 1161 return; 1162 } 1163 out: 1164 mutex_unlock(&con->sock_mutex); 1165 return; 1166 } 1167 1168 /* On error caller must run dlm_close_sock() for the 1169 * listen connection socket. 1170 */ 1171 static int tcp_create_listen_sock(struct listen_connection *con, 1172 struct sockaddr_storage *saddr) 1173 { 1174 struct socket *sock = NULL; 1175 int result = 0; 1176 int addr_len; 1177 1178 if (dlm_local_addr[0]->ss_family == AF_INET) 1179 addr_len = sizeof(struct sockaddr_in); 1180 else 1181 addr_len = sizeof(struct sockaddr_in6); 1182 1183 /* Create a socket to communicate with */ 1184 result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family, 1185 SOCK_STREAM, IPPROTO_TCP, &sock); 1186 if (result < 0) { 1187 log_print("Can't create listening comms socket"); 1188 goto create_out; 1189 } 1190 1191 sock_set_mark(sock->sk, dlm_config.ci_mark); 1192 1193 /* Turn off Nagle's algorithm */ 1194 tcp_sock_set_nodelay(sock->sk); 1195 1196 sock_set_reuseaddr(sock->sk); 1197 1198 add_listen_sock(sock, con); 1199 1200 /* Bind to our port */ 1201 make_sockaddr(saddr, dlm_config.ci_tcp_port, &addr_len); 1202 result = sock->ops->bind(sock, (struct sockaddr *) saddr, addr_len); 1203 if (result < 0) { 1204 log_print("Can't bind to port %d", dlm_config.ci_tcp_port); 1205 goto create_out; 1206 } 1207 sock_set_keepalive(sock->sk); 1208 1209 result = sock->ops->listen(sock, 5); 1210 if (result < 0) { 1211 log_print("Can't listen on port %d", dlm_config.ci_tcp_port); 1212 goto create_out; 1213 } 1214 1215 return 0; 1216 1217 create_out: 1218 return result; 1219 } 1220 1221 /* Get local addresses */ 1222 static void init_local(void) 1223 { 1224 struct sockaddr_storage sas, *addr; 1225 int i; 1226 1227 dlm_local_count = 0; 1228 for (i = 0; i < DLM_MAX_ADDR_COUNT; i++) { 1229 if (dlm_our_addr(&sas, i)) 1230 break; 1231 1232 addr = kmemdup(&sas, sizeof(*addr), GFP_NOFS); 1233 if (!addr) 1234 break; 1235 dlm_local_addr[dlm_local_count++] = addr; 1236 } 1237 } 1238 1239 static void deinit_local(void) 1240 { 1241 int i; 1242 1243 for (i = 0; i < dlm_local_count; i++) 1244 kfree(dlm_local_addr[i]); 1245 } 1246 1247 /* Initialise SCTP socket and bind to all interfaces 1248 * On error caller must run dlm_close_sock() for the 1249 * listen connection socket. 1250 */ 1251 static int sctp_listen_for_all(struct listen_connection *con) 1252 { 1253 struct socket *sock = NULL; 1254 int result = -EINVAL; 1255 1256 log_print("Using SCTP for communications"); 1257 1258 result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family, 1259 SOCK_STREAM, IPPROTO_SCTP, &sock); 1260 if (result < 0) { 1261 log_print("Can't create comms socket, check SCTP is loaded"); 1262 goto out; 1263 } 1264 1265 sock_set_rcvbuf(sock->sk, NEEDED_RMEM); 1266 sock_set_mark(sock->sk, dlm_config.ci_mark); 1267 sctp_sock_set_nodelay(sock->sk); 1268 1269 add_listen_sock(sock, con); 1270 1271 /* Bind to all addresses. */ 1272 result = sctp_bind_addrs(con->sock, dlm_config.ci_tcp_port); 1273 if (result < 0) 1274 goto out; 1275 1276 result = sock->ops->listen(sock, 5); 1277 if (result < 0) { 1278 log_print("Can't set socket listening"); 1279 goto out; 1280 } 1281 1282 return 0; 1283 1284 out: 1285 return result; 1286 } 1287 1288 static int tcp_listen_for_all(void) 1289 { 1290 /* We don't support multi-homed hosts */ 1291 if (dlm_local_addr[1] != NULL) { 1292 log_print("TCP protocol can't handle multi-homed hosts, " 1293 "try SCTP"); 1294 return -EINVAL; 1295 } 1296 1297 log_print("Using TCP for communications"); 1298 1299 return tcp_create_listen_sock(&listen_con, dlm_local_addr[0]); 1300 } 1301 1302 1303 1304 static struct writequeue_entry *new_writequeue_entry(struct connection *con, 1305 gfp_t allocation) 1306 { 1307 struct writequeue_entry *entry; 1308 1309 entry = kmalloc(sizeof(struct writequeue_entry), allocation); 1310 if (!entry) 1311 return NULL; 1312 1313 entry->page = alloc_page(allocation); 1314 if (!entry->page) { 1315 kfree(entry); 1316 return NULL; 1317 } 1318 1319 entry->offset = 0; 1320 entry->len = 0; 1321 entry->end = 0; 1322 entry->users = 0; 1323 entry->con = con; 1324 1325 return entry; 1326 } 1327 1328 void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc) 1329 { 1330 struct connection *con; 1331 struct writequeue_entry *e; 1332 int offset = 0; 1333 1334 if (len > LOWCOMMS_MAX_TX_BUFFER_LEN) { 1335 BUILD_BUG_ON(PAGE_SIZE < LOWCOMMS_MAX_TX_BUFFER_LEN); 1336 log_print("failed to allocate a buffer of size %d", len); 1337 return NULL; 1338 } 1339 1340 con = nodeid2con(nodeid, allocation); 1341 if (!con) 1342 return NULL; 1343 1344 spin_lock(&con->writequeue_lock); 1345 e = list_entry(con->writequeue.prev, struct writequeue_entry, list); 1346 if ((&e->list == &con->writequeue) || 1347 (PAGE_SIZE - e->end < len)) { 1348 e = NULL; 1349 } else { 1350 offset = e->end; 1351 e->end += len; 1352 e->users++; 1353 } 1354 spin_unlock(&con->writequeue_lock); 1355 1356 if (e) { 1357 got_one: 1358 *ppc = page_address(e->page) + offset; 1359 return e; 1360 } 1361 1362 e = new_writequeue_entry(con, allocation); 1363 if (e) { 1364 spin_lock(&con->writequeue_lock); 1365 offset = e->end; 1366 e->end += len; 1367 e->users++; 1368 list_add_tail(&e->list, &con->writequeue); 1369 spin_unlock(&con->writequeue_lock); 1370 goto got_one; 1371 } 1372 return NULL; 1373 } 1374 1375 void dlm_lowcomms_commit_buffer(void *mh) 1376 { 1377 struct writequeue_entry *e = (struct writequeue_entry *)mh; 1378 struct connection *con = e->con; 1379 int users; 1380 1381 spin_lock(&con->writequeue_lock); 1382 users = --e->users; 1383 if (users) 1384 goto out; 1385 e->len = e->end - e->offset; 1386 spin_unlock(&con->writequeue_lock); 1387 1388 queue_work(send_workqueue, &con->swork); 1389 return; 1390 1391 out: 1392 spin_unlock(&con->writequeue_lock); 1393 return; 1394 } 1395 1396 /* Send a message */ 1397 static void send_to_sock(struct connection *con) 1398 { 1399 int ret = 0; 1400 const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL; 1401 struct writequeue_entry *e; 1402 int len, offset; 1403 int count = 0; 1404 1405 mutex_lock(&con->sock_mutex); 1406 if (con->sock == NULL) 1407 goto out_connect; 1408 1409 spin_lock(&con->writequeue_lock); 1410 for (;;) { 1411 e = list_entry(con->writequeue.next, struct writequeue_entry, 1412 list); 1413 if ((struct list_head *) e == &con->writequeue) 1414 break; 1415 1416 len = e->len; 1417 offset = e->offset; 1418 BUG_ON(len == 0 && e->users == 0); 1419 spin_unlock(&con->writequeue_lock); 1420 1421 ret = 0; 1422 if (len) { 1423 ret = kernel_sendpage(con->sock, e->page, offset, len, 1424 msg_flags); 1425 if (ret == -EAGAIN || ret == 0) { 1426 if (ret == -EAGAIN && 1427 test_bit(SOCKWQ_ASYNC_NOSPACE, &con->sock->flags) && 1428 !test_and_set_bit(CF_APP_LIMITED, &con->flags)) { 1429 /* Notify TCP that we're limited by the 1430 * application window size. 1431 */ 1432 set_bit(SOCK_NOSPACE, &con->sock->flags); 1433 con->sock->sk->sk_write_pending++; 1434 } 1435 cond_resched(); 1436 goto out; 1437 } else if (ret < 0) 1438 goto send_error; 1439 } 1440 1441 /* Don't starve people filling buffers */ 1442 if (++count >= MAX_SEND_MSG_COUNT) { 1443 cond_resched(); 1444 count = 0; 1445 } 1446 1447 spin_lock(&con->writequeue_lock); 1448 writequeue_entry_complete(e, ret); 1449 } 1450 spin_unlock(&con->writequeue_lock); 1451 out: 1452 mutex_unlock(&con->sock_mutex); 1453 return; 1454 1455 send_error: 1456 mutex_unlock(&con->sock_mutex); 1457 close_connection(con, false, false, true); 1458 /* Requeue the send work. When the work daemon runs again, it will try 1459 a new connection, then call this function again. */ 1460 queue_work(send_workqueue, &con->swork); 1461 return; 1462 1463 out_connect: 1464 mutex_unlock(&con->sock_mutex); 1465 queue_work(send_workqueue, &con->swork); 1466 cond_resched(); 1467 } 1468 1469 static void clean_one_writequeue(struct connection *con) 1470 { 1471 struct writequeue_entry *e, *safe; 1472 1473 spin_lock(&con->writequeue_lock); 1474 list_for_each_entry_safe(e, safe, &con->writequeue, list) { 1475 list_del(&e->list); 1476 free_entry(e); 1477 } 1478 spin_unlock(&con->writequeue_lock); 1479 } 1480 1481 /* Called from recovery when it knows that a node has 1482 left the cluster */ 1483 int dlm_lowcomms_close(int nodeid) 1484 { 1485 struct connection *con; 1486 struct dlm_node_addr *na; 1487 1488 log_print("closing connection to node %d", nodeid); 1489 con = nodeid2con(nodeid, 0); 1490 if (con) { 1491 set_bit(CF_CLOSE, &con->flags); 1492 close_connection(con, true, true, true); 1493 clean_one_writequeue(con); 1494 if (con->othercon) 1495 clean_one_writequeue(con->othercon); 1496 } 1497 1498 spin_lock(&dlm_node_addrs_spin); 1499 na = find_node_addr(nodeid); 1500 if (na) { 1501 list_del(&na->list); 1502 while (na->addr_count--) 1503 kfree(na->addr[na->addr_count]); 1504 kfree(na); 1505 } 1506 spin_unlock(&dlm_node_addrs_spin); 1507 1508 return 0; 1509 } 1510 1511 /* Receive workqueue function */ 1512 static void process_recv_sockets(struct work_struct *work) 1513 { 1514 struct connection *con = container_of(work, struct connection, rwork); 1515 int err; 1516 1517 clear_bit(CF_READ_PENDING, &con->flags); 1518 do { 1519 err = receive_from_sock(con); 1520 } while (!err); 1521 } 1522 1523 static void process_listen_recv_socket(struct work_struct *work) 1524 { 1525 accept_from_sock(&listen_con); 1526 } 1527 1528 /* Send workqueue function */ 1529 static void process_send_sockets(struct work_struct *work) 1530 { 1531 struct connection *con = container_of(work, struct connection, swork); 1532 1533 clear_bit(CF_WRITE_PENDING, &con->flags); 1534 if (con->sock == NULL) /* not mutex protected so check it inside too */ 1535 con->connect_action(con); 1536 if (!list_empty(&con->writequeue)) 1537 send_to_sock(con); 1538 } 1539 1540 static void work_stop(void) 1541 { 1542 if (recv_workqueue) 1543 destroy_workqueue(recv_workqueue); 1544 if (send_workqueue) 1545 destroy_workqueue(send_workqueue); 1546 } 1547 1548 static int work_start(void) 1549 { 1550 recv_workqueue = alloc_workqueue("dlm_recv", 1551 WQ_UNBOUND | WQ_MEM_RECLAIM, 1); 1552 if (!recv_workqueue) { 1553 log_print("can't start dlm_recv"); 1554 return -ENOMEM; 1555 } 1556 1557 send_workqueue = alloc_workqueue("dlm_send", 1558 WQ_UNBOUND | WQ_MEM_RECLAIM, 1); 1559 if (!send_workqueue) { 1560 log_print("can't start dlm_send"); 1561 destroy_workqueue(recv_workqueue); 1562 return -ENOMEM; 1563 } 1564 1565 return 0; 1566 } 1567 1568 static void _stop_conn(struct connection *con, bool and_other) 1569 { 1570 mutex_lock(&con->sock_mutex); 1571 set_bit(CF_CLOSE, &con->flags); 1572 set_bit(CF_READ_PENDING, &con->flags); 1573 set_bit(CF_WRITE_PENDING, &con->flags); 1574 if (con->sock && con->sock->sk) { 1575 write_lock_bh(&con->sock->sk->sk_callback_lock); 1576 con->sock->sk->sk_user_data = NULL; 1577 write_unlock_bh(&con->sock->sk->sk_callback_lock); 1578 } 1579 if (con->othercon && and_other) 1580 _stop_conn(con->othercon, false); 1581 mutex_unlock(&con->sock_mutex); 1582 } 1583 1584 static void stop_conn(struct connection *con) 1585 { 1586 _stop_conn(con, true); 1587 } 1588 1589 static void shutdown_conn(struct connection *con) 1590 { 1591 if (con->shutdown_action) 1592 con->shutdown_action(con); 1593 } 1594 1595 static void connection_release(struct rcu_head *rcu) 1596 { 1597 struct connection *con = container_of(rcu, struct connection, rcu); 1598 1599 kfree(con->rx_buf); 1600 kfree(con); 1601 } 1602 1603 static void free_conn(struct connection *con) 1604 { 1605 close_connection(con, true, true, true); 1606 spin_lock(&connections_lock); 1607 hlist_del_rcu(&con->list); 1608 spin_unlock(&connections_lock); 1609 if (con->othercon) { 1610 clean_one_writequeue(con->othercon); 1611 call_srcu(&connections_srcu, &con->othercon->rcu, 1612 connection_release); 1613 } 1614 clean_one_writequeue(con); 1615 call_srcu(&connections_srcu, &con->rcu, connection_release); 1616 } 1617 1618 static void work_flush(void) 1619 { 1620 int ok, idx; 1621 int i; 1622 struct connection *con; 1623 1624 do { 1625 ok = 1; 1626 foreach_conn(stop_conn); 1627 if (recv_workqueue) 1628 flush_workqueue(recv_workqueue); 1629 if (send_workqueue) 1630 flush_workqueue(send_workqueue); 1631 idx = srcu_read_lock(&connections_srcu); 1632 for (i = 0; i < CONN_HASH_SIZE && ok; i++) { 1633 hlist_for_each_entry_rcu(con, &connection_hash[i], 1634 list) { 1635 ok &= test_bit(CF_READ_PENDING, &con->flags); 1636 ok &= test_bit(CF_WRITE_PENDING, &con->flags); 1637 if (con->othercon) { 1638 ok &= test_bit(CF_READ_PENDING, 1639 &con->othercon->flags); 1640 ok &= test_bit(CF_WRITE_PENDING, 1641 &con->othercon->flags); 1642 } 1643 } 1644 } 1645 srcu_read_unlock(&connections_srcu, idx); 1646 } while (!ok); 1647 } 1648 1649 void dlm_lowcomms_stop(void) 1650 { 1651 /* Set all the flags to prevent any 1652 socket activity. 1653 */ 1654 dlm_allow_conn = 0; 1655 1656 if (recv_workqueue) 1657 flush_workqueue(recv_workqueue); 1658 if (send_workqueue) 1659 flush_workqueue(send_workqueue); 1660 1661 dlm_close_sock(&listen_con.sock); 1662 1663 foreach_conn(shutdown_conn); 1664 work_flush(); 1665 foreach_conn(free_conn); 1666 work_stop(); 1667 deinit_local(); 1668 } 1669 1670 int dlm_lowcomms_start(void) 1671 { 1672 int error = -EINVAL; 1673 int i; 1674 1675 for (i = 0; i < CONN_HASH_SIZE; i++) 1676 INIT_HLIST_HEAD(&connection_hash[i]); 1677 1678 init_local(); 1679 if (!dlm_local_count) { 1680 error = -ENOTCONN; 1681 log_print("no local IP address has been set"); 1682 goto fail; 1683 } 1684 1685 INIT_WORK(&listen_con.rwork, process_listen_recv_socket); 1686 1687 error = work_start(); 1688 if (error) 1689 goto fail; 1690 1691 dlm_allow_conn = 1; 1692 1693 /* Start listening */ 1694 if (dlm_config.ci_protocol == 0) 1695 error = tcp_listen_for_all(); 1696 else 1697 error = sctp_listen_for_all(&listen_con); 1698 if (error) 1699 goto fail_unlisten; 1700 1701 return 0; 1702 1703 fail_unlisten: 1704 dlm_allow_conn = 0; 1705 dlm_close_sock(&listen_con.sock); 1706 fail: 1707 return error; 1708 } 1709 1710 void dlm_lowcomms_exit(void) 1711 { 1712 struct dlm_node_addr *na, *safe; 1713 1714 spin_lock(&dlm_node_addrs_spin); 1715 list_for_each_entry_safe(na, safe, &dlm_node_addrs, list) { 1716 list_del(&na->list); 1717 while (na->addr_count--) 1718 kfree(na->addr[na->addr_count]); 1719 kfree(na); 1720 } 1721 spin_unlock(&dlm_node_addrs_spin); 1722 } 1723