1 /****************************************************************************** 2 ******************************************************************************* 3 ** 4 ** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. 5 ** Copyright (C) 2004-2009 Red Hat, Inc. All rights reserved. 6 ** 7 ** This copyrighted material is made available to anyone wishing to use, 8 ** modify, copy, or redistribute it subject to the terms and conditions 9 ** of the GNU General Public License v.2. 10 ** 11 ******************************************************************************* 12 ******************************************************************************/ 13 14 /* 15 * lowcomms.c 16 * 17 * This is the "low-level" comms layer. 18 * 19 * It is responsible for sending/receiving messages 20 * from other nodes in the cluster. 21 * 22 * Cluster nodes are referred to by their nodeids. nodeids are 23 * simply 32 bit numbers to the locking module - if they need to 24 * be expanded for the cluster infrastructure then that is its 25 * responsibility. It is this layer's 26 * responsibility to resolve these into IP address or 27 * whatever it needs for inter-node communication. 28 * 29 * The comms level is two kernel threads that deal mainly with 30 * the receiving of messages from other nodes and passing them 31 * up to the mid-level comms layer (which understands the 32 * message format) for execution by the locking core, and 33 * a send thread which does all the setting up of connections 34 * to remote nodes and the sending of data. Threads are not allowed 35 * to send their own data because it may cause them to wait in times 36 * of high load. Also, this way, the sending thread can collect together 37 * messages bound for one node and send them in one block. 38 * 39 * lowcomms will choose to use either TCP or SCTP as its transport layer 40 * depending on the configuration variable 'protocol'. This should be set 41 * to 0 (default) for TCP or 1 for SCTP. It should be configured using a 42 * cluster-wide mechanism as it must be the same on all nodes of the cluster 43 * for the DLM to function. 44 * 45 */ 46 47 #include <asm/ioctls.h> 48 #include <net/sock.h> 49 #include <net/tcp.h> 50 #include <linux/pagemap.h> 51 #include <linux/file.h> 52 #include <linux/mutex.h> 53 #include <linux/sctp.h> 54 #include <linux/slab.h> 55 #include <net/sctp/sctp.h> 56 #include <net/ipv6.h> 57 58 #include "dlm_internal.h" 59 #include "lowcomms.h" 60 #include "midcomms.h" 61 #include "config.h" 62 63 #define NEEDED_RMEM (4*1024*1024) 64 #define CONN_HASH_SIZE 32 65 66 /* Number of messages to send before rescheduling */ 67 #define MAX_SEND_MSG_COUNT 25 68 69 struct cbuf { 70 unsigned int base; 71 unsigned int len; 72 unsigned int mask; 73 }; 74 75 static void cbuf_add(struct cbuf *cb, int n) 76 { 77 cb->len += n; 78 } 79 80 static int cbuf_data(struct cbuf *cb) 81 { 82 return ((cb->base + cb->len) & cb->mask); 83 } 84 85 static void cbuf_init(struct cbuf *cb, int size) 86 { 87 cb->base = cb->len = 0; 88 cb->mask = size-1; 89 } 90 91 static void cbuf_eat(struct cbuf *cb, int n) 92 { 93 cb->len -= n; 94 cb->base += n; 95 cb->base &= cb->mask; 96 } 97 98 static bool cbuf_empty(struct cbuf *cb) 99 { 100 return cb->len == 0; 101 } 102 103 struct connection { 104 struct socket *sock; /* NULL if not connected */ 105 uint32_t nodeid; /* So we know who we are in the list */ 106 struct mutex sock_mutex; 107 unsigned long flags; 108 #define CF_READ_PENDING 1 109 #define CF_INIT_PENDING 4 110 #define CF_IS_OTHERCON 5 111 #define CF_CLOSE 6 112 #define CF_APP_LIMITED 7 113 struct list_head writequeue; /* List of outgoing writequeue_entries */ 114 spinlock_t writequeue_lock; 115 int (*rx_action) (struct connection *); /* What to do when active */ 116 void (*connect_action) (struct connection *); /* What to do to connect */ 117 struct page *rx_page; 118 struct cbuf cb; 119 int retries; 120 #define MAX_CONNECT_RETRIES 3 121 struct hlist_node list; 122 struct connection *othercon; 123 struct work_struct rwork; /* Receive workqueue */ 124 struct work_struct swork; /* Send workqueue */ 125 }; 126 #define sock2con(x) ((struct connection *)(x)->sk_user_data) 127 128 /* An entry waiting to be sent */ 129 struct writequeue_entry { 130 struct list_head list; 131 struct page *page; 132 int offset; 133 int len; 134 int end; 135 int users; 136 struct connection *con; 137 }; 138 139 struct dlm_node_addr { 140 struct list_head list; 141 int nodeid; 142 int addr_count; 143 int curr_addr_index; 144 struct sockaddr_storage *addr[DLM_MAX_ADDR_COUNT]; 145 }; 146 147 static struct listen_sock_callbacks { 148 void (*sk_error_report)(struct sock *); 149 void (*sk_data_ready)(struct sock *); 150 void (*sk_state_change)(struct sock *); 151 void (*sk_write_space)(struct sock *); 152 } listen_sock; 153 154 static LIST_HEAD(dlm_node_addrs); 155 static DEFINE_SPINLOCK(dlm_node_addrs_spin); 156 157 static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT]; 158 static int dlm_local_count; 159 static int dlm_allow_conn; 160 161 /* Work queues */ 162 static struct workqueue_struct *recv_workqueue; 163 static struct workqueue_struct *send_workqueue; 164 165 static struct hlist_head connection_hash[CONN_HASH_SIZE]; 166 static DEFINE_MUTEX(connections_lock); 167 static struct kmem_cache *con_cache; 168 169 static void process_recv_sockets(struct work_struct *work); 170 static void process_send_sockets(struct work_struct *work); 171 172 173 /* This is deliberately very simple because most clusters have simple 174 sequential nodeids, so we should be able to go straight to a connection 175 struct in the array */ 176 static inline int nodeid_hash(int nodeid) 177 { 178 return nodeid & (CONN_HASH_SIZE-1); 179 } 180 181 static struct connection *__find_con(int nodeid) 182 { 183 int r; 184 struct connection *con; 185 186 r = nodeid_hash(nodeid); 187 188 hlist_for_each_entry(con, &connection_hash[r], list) { 189 if (con->nodeid == nodeid) 190 return con; 191 } 192 return NULL; 193 } 194 195 /* 196 * If 'allocation' is zero then we don't attempt to create a new 197 * connection structure for this node. 198 */ 199 static struct connection *__nodeid2con(int nodeid, gfp_t alloc) 200 { 201 struct connection *con = NULL; 202 int r; 203 204 con = __find_con(nodeid); 205 if (con || !alloc) 206 return con; 207 208 con = kmem_cache_zalloc(con_cache, alloc); 209 if (!con) 210 return NULL; 211 212 r = nodeid_hash(nodeid); 213 hlist_add_head(&con->list, &connection_hash[r]); 214 215 con->nodeid = nodeid; 216 mutex_init(&con->sock_mutex); 217 INIT_LIST_HEAD(&con->writequeue); 218 spin_lock_init(&con->writequeue_lock); 219 INIT_WORK(&con->swork, process_send_sockets); 220 INIT_WORK(&con->rwork, process_recv_sockets); 221 222 /* Setup action pointers for child sockets */ 223 if (con->nodeid) { 224 struct connection *zerocon = __find_con(0); 225 226 con->connect_action = zerocon->connect_action; 227 if (!con->rx_action) 228 con->rx_action = zerocon->rx_action; 229 } 230 231 return con; 232 } 233 234 /* Loop round all connections */ 235 static void foreach_conn(void (*conn_func)(struct connection *c)) 236 { 237 int i; 238 struct hlist_node *n; 239 struct connection *con; 240 241 for (i = 0; i < CONN_HASH_SIZE; i++) { 242 hlist_for_each_entry_safe(con, n, &connection_hash[i], list) 243 conn_func(con); 244 } 245 } 246 247 static struct connection *nodeid2con(int nodeid, gfp_t allocation) 248 { 249 struct connection *con; 250 251 mutex_lock(&connections_lock); 252 con = __nodeid2con(nodeid, allocation); 253 mutex_unlock(&connections_lock); 254 255 return con; 256 } 257 258 static struct dlm_node_addr *find_node_addr(int nodeid) 259 { 260 struct dlm_node_addr *na; 261 262 list_for_each_entry(na, &dlm_node_addrs, list) { 263 if (na->nodeid == nodeid) 264 return na; 265 } 266 return NULL; 267 } 268 269 static int addr_compare(struct sockaddr_storage *x, struct sockaddr_storage *y) 270 { 271 switch (x->ss_family) { 272 case AF_INET: { 273 struct sockaddr_in *sinx = (struct sockaddr_in *)x; 274 struct sockaddr_in *siny = (struct sockaddr_in *)y; 275 if (sinx->sin_addr.s_addr != siny->sin_addr.s_addr) 276 return 0; 277 if (sinx->sin_port != siny->sin_port) 278 return 0; 279 break; 280 } 281 case AF_INET6: { 282 struct sockaddr_in6 *sinx = (struct sockaddr_in6 *)x; 283 struct sockaddr_in6 *siny = (struct sockaddr_in6 *)y; 284 if (!ipv6_addr_equal(&sinx->sin6_addr, &siny->sin6_addr)) 285 return 0; 286 if (sinx->sin6_port != siny->sin6_port) 287 return 0; 288 break; 289 } 290 default: 291 return 0; 292 } 293 return 1; 294 } 295 296 static int nodeid_to_addr(int nodeid, struct sockaddr_storage *sas_out, 297 struct sockaddr *sa_out, bool try_new_addr) 298 { 299 struct sockaddr_storage sas; 300 struct dlm_node_addr *na; 301 302 if (!dlm_local_count) 303 return -1; 304 305 spin_lock(&dlm_node_addrs_spin); 306 na = find_node_addr(nodeid); 307 if (na && na->addr_count) { 308 memcpy(&sas, na->addr[na->curr_addr_index], 309 sizeof(struct sockaddr_storage)); 310 311 if (try_new_addr) { 312 na->curr_addr_index++; 313 if (na->curr_addr_index == na->addr_count) 314 na->curr_addr_index = 0; 315 } 316 } 317 spin_unlock(&dlm_node_addrs_spin); 318 319 if (!na) 320 return -EEXIST; 321 322 if (!na->addr_count) 323 return -ENOENT; 324 325 if (sas_out) 326 memcpy(sas_out, &sas, sizeof(struct sockaddr_storage)); 327 328 if (!sa_out) 329 return 0; 330 331 if (dlm_local_addr[0]->ss_family == AF_INET) { 332 struct sockaddr_in *in4 = (struct sockaddr_in *) &sas; 333 struct sockaddr_in *ret4 = (struct sockaddr_in *) sa_out; 334 ret4->sin_addr.s_addr = in4->sin_addr.s_addr; 335 } else { 336 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) &sas; 337 struct sockaddr_in6 *ret6 = (struct sockaddr_in6 *) sa_out; 338 ret6->sin6_addr = in6->sin6_addr; 339 } 340 341 return 0; 342 } 343 344 static int addr_to_nodeid(struct sockaddr_storage *addr, int *nodeid) 345 { 346 struct dlm_node_addr *na; 347 int rv = -EEXIST; 348 int addr_i; 349 350 spin_lock(&dlm_node_addrs_spin); 351 list_for_each_entry(na, &dlm_node_addrs, list) { 352 if (!na->addr_count) 353 continue; 354 355 for (addr_i = 0; addr_i < na->addr_count; addr_i++) { 356 if (addr_compare(na->addr[addr_i], addr)) { 357 *nodeid = na->nodeid; 358 rv = 0; 359 goto unlock; 360 } 361 } 362 } 363 unlock: 364 spin_unlock(&dlm_node_addrs_spin); 365 return rv; 366 } 367 368 int dlm_lowcomms_addr(int nodeid, struct sockaddr_storage *addr, int len) 369 { 370 struct sockaddr_storage *new_addr; 371 struct dlm_node_addr *new_node, *na; 372 373 new_node = kzalloc(sizeof(struct dlm_node_addr), GFP_NOFS); 374 if (!new_node) 375 return -ENOMEM; 376 377 new_addr = kzalloc(sizeof(struct sockaddr_storage), GFP_NOFS); 378 if (!new_addr) { 379 kfree(new_node); 380 return -ENOMEM; 381 } 382 383 memcpy(new_addr, addr, len); 384 385 spin_lock(&dlm_node_addrs_spin); 386 na = find_node_addr(nodeid); 387 if (!na) { 388 new_node->nodeid = nodeid; 389 new_node->addr[0] = new_addr; 390 new_node->addr_count = 1; 391 list_add(&new_node->list, &dlm_node_addrs); 392 spin_unlock(&dlm_node_addrs_spin); 393 return 0; 394 } 395 396 if (na->addr_count >= DLM_MAX_ADDR_COUNT) { 397 spin_unlock(&dlm_node_addrs_spin); 398 kfree(new_addr); 399 kfree(new_node); 400 return -ENOSPC; 401 } 402 403 na->addr[na->addr_count++] = new_addr; 404 spin_unlock(&dlm_node_addrs_spin); 405 kfree(new_node); 406 return 0; 407 } 408 409 /* Data available on socket or listen socket received a connect */ 410 static void lowcomms_data_ready(struct sock *sk) 411 { 412 struct connection *con = sock2con(sk); 413 if (con && !test_and_set_bit(CF_READ_PENDING, &con->flags)) 414 queue_work(recv_workqueue, &con->rwork); 415 } 416 417 static void lowcomms_write_space(struct sock *sk) 418 { 419 struct connection *con = sock2con(sk); 420 421 if (!con) 422 return; 423 424 clear_bit(SOCK_NOSPACE, &con->sock->flags); 425 426 if (test_and_clear_bit(CF_APP_LIMITED, &con->flags)) { 427 con->sock->sk->sk_write_pending--; 428 clear_bit(SOCKWQ_ASYNC_NOSPACE, &con->sock->flags); 429 } 430 431 queue_work(send_workqueue, &con->swork); 432 } 433 434 static inline void lowcomms_connect_sock(struct connection *con) 435 { 436 if (test_bit(CF_CLOSE, &con->flags)) 437 return; 438 queue_work(send_workqueue, &con->swork); 439 cond_resched(); 440 } 441 442 static void lowcomms_state_change(struct sock *sk) 443 { 444 /* SCTP layer is not calling sk_data_ready when the connection 445 * is done, so we catch the signal through here. Also, it 446 * doesn't switch socket state when entering shutdown, so we 447 * skip the write in that case. 448 */ 449 if (sk->sk_shutdown) { 450 if (sk->sk_shutdown == RCV_SHUTDOWN) 451 lowcomms_data_ready(sk); 452 } else if (sk->sk_state == TCP_ESTABLISHED) { 453 lowcomms_write_space(sk); 454 } 455 } 456 457 int dlm_lowcomms_connect_node(int nodeid) 458 { 459 struct connection *con; 460 461 if (nodeid == dlm_our_nodeid()) 462 return 0; 463 464 con = nodeid2con(nodeid, GFP_NOFS); 465 if (!con) 466 return -ENOMEM; 467 lowcomms_connect_sock(con); 468 return 0; 469 } 470 471 static void lowcomms_error_report(struct sock *sk) 472 { 473 struct connection *con; 474 struct sockaddr_storage saddr; 475 int buflen; 476 void (*orig_report)(struct sock *) = NULL; 477 478 read_lock_bh(&sk->sk_callback_lock); 479 con = sock2con(sk); 480 if (con == NULL) 481 goto out; 482 483 orig_report = listen_sock.sk_error_report; 484 if (con->sock == NULL || 485 kernel_getpeername(con->sock, (struct sockaddr *)&saddr, &buflen)) { 486 printk_ratelimited(KERN_ERR "dlm: node %d: socket error " 487 "sending to node %d, port %d, " 488 "sk_err=%d/%d\n", dlm_our_nodeid(), 489 con->nodeid, dlm_config.ci_tcp_port, 490 sk->sk_err, sk->sk_err_soft); 491 } else if (saddr.ss_family == AF_INET) { 492 struct sockaddr_in *sin4 = (struct sockaddr_in *)&saddr; 493 494 printk_ratelimited(KERN_ERR "dlm: node %d: socket error " 495 "sending to node %d at %pI4, port %d, " 496 "sk_err=%d/%d\n", dlm_our_nodeid(), 497 con->nodeid, &sin4->sin_addr.s_addr, 498 dlm_config.ci_tcp_port, sk->sk_err, 499 sk->sk_err_soft); 500 } else { 501 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&saddr; 502 503 printk_ratelimited(KERN_ERR "dlm: node %d: socket error " 504 "sending to node %d at %u.%u.%u.%u, " 505 "port %d, sk_err=%d/%d\n", dlm_our_nodeid(), 506 con->nodeid, sin6->sin6_addr.s6_addr32[0], 507 sin6->sin6_addr.s6_addr32[1], 508 sin6->sin6_addr.s6_addr32[2], 509 sin6->sin6_addr.s6_addr32[3], 510 dlm_config.ci_tcp_port, sk->sk_err, 511 sk->sk_err_soft); 512 } 513 out: 514 read_unlock_bh(&sk->sk_callback_lock); 515 if (orig_report) 516 orig_report(sk); 517 } 518 519 /* Note: sk_callback_lock must be locked before calling this function. */ 520 static void save_listen_callbacks(struct socket *sock) 521 { 522 struct sock *sk = sock->sk; 523 524 listen_sock.sk_data_ready = sk->sk_data_ready; 525 listen_sock.sk_state_change = sk->sk_state_change; 526 listen_sock.sk_write_space = sk->sk_write_space; 527 listen_sock.sk_error_report = sk->sk_error_report; 528 } 529 530 static void restore_callbacks(struct socket *sock) 531 { 532 struct sock *sk = sock->sk; 533 534 write_lock_bh(&sk->sk_callback_lock); 535 sk->sk_user_data = NULL; 536 sk->sk_data_ready = listen_sock.sk_data_ready; 537 sk->sk_state_change = listen_sock.sk_state_change; 538 sk->sk_write_space = listen_sock.sk_write_space; 539 sk->sk_error_report = listen_sock.sk_error_report; 540 write_unlock_bh(&sk->sk_callback_lock); 541 } 542 543 /* Make a socket active */ 544 static void add_sock(struct socket *sock, struct connection *con) 545 { 546 struct sock *sk = sock->sk; 547 548 write_lock_bh(&sk->sk_callback_lock); 549 con->sock = sock; 550 551 sk->sk_user_data = con; 552 /* Install a data_ready callback */ 553 sk->sk_data_ready = lowcomms_data_ready; 554 sk->sk_write_space = lowcomms_write_space; 555 sk->sk_state_change = lowcomms_state_change; 556 sk->sk_allocation = GFP_NOFS; 557 sk->sk_error_report = lowcomms_error_report; 558 write_unlock_bh(&sk->sk_callback_lock); 559 } 560 561 /* Add the port number to an IPv6 or 4 sockaddr and return the address 562 length */ 563 static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port, 564 int *addr_len) 565 { 566 saddr->ss_family = dlm_local_addr[0]->ss_family; 567 if (saddr->ss_family == AF_INET) { 568 struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr; 569 in4_addr->sin_port = cpu_to_be16(port); 570 *addr_len = sizeof(struct sockaddr_in); 571 memset(&in4_addr->sin_zero, 0, sizeof(in4_addr->sin_zero)); 572 } else { 573 struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr; 574 in6_addr->sin6_port = cpu_to_be16(port); 575 *addr_len = sizeof(struct sockaddr_in6); 576 } 577 memset((char *)saddr + *addr_len, 0, sizeof(struct sockaddr_storage) - *addr_len); 578 } 579 580 /* Close a remote connection and tidy up */ 581 static void close_connection(struct connection *con, bool and_other, 582 bool tx, bool rx) 583 { 584 if (tx && cancel_work_sync(&con->swork)) 585 log_print("canceled swork for node %d", con->nodeid); 586 if (rx && cancel_work_sync(&con->rwork)) 587 log_print("canceled rwork for node %d", con->nodeid); 588 589 mutex_lock(&con->sock_mutex); 590 if (con->sock) { 591 restore_callbacks(con->sock); 592 sock_release(con->sock); 593 con->sock = NULL; 594 } 595 if (con->othercon && and_other) { 596 /* Will only re-enter once. */ 597 close_connection(con->othercon, false, true, true); 598 } 599 if (con->rx_page) { 600 __free_page(con->rx_page); 601 con->rx_page = NULL; 602 } 603 604 con->retries = 0; 605 mutex_unlock(&con->sock_mutex); 606 } 607 608 /* Data received from remote end */ 609 static int receive_from_sock(struct connection *con) 610 { 611 int ret = 0; 612 struct msghdr msg = {}; 613 struct kvec iov[2]; 614 unsigned len; 615 int r; 616 int call_again_soon = 0; 617 int nvec; 618 619 mutex_lock(&con->sock_mutex); 620 621 if (con->sock == NULL) { 622 ret = -EAGAIN; 623 goto out_close; 624 } 625 if (con->nodeid == 0) { 626 ret = -EINVAL; 627 goto out_close; 628 } 629 630 if (con->rx_page == NULL) { 631 /* 632 * This doesn't need to be atomic, but I think it should 633 * improve performance if it is. 634 */ 635 con->rx_page = alloc_page(GFP_ATOMIC); 636 if (con->rx_page == NULL) 637 goto out_resched; 638 cbuf_init(&con->cb, PAGE_SIZE); 639 } 640 641 /* 642 * iov[0] is the bit of the circular buffer between the current end 643 * point (cb.base + cb.len) and the end of the buffer. 644 */ 645 iov[0].iov_len = con->cb.base - cbuf_data(&con->cb); 646 iov[0].iov_base = page_address(con->rx_page) + cbuf_data(&con->cb); 647 iov[1].iov_len = 0; 648 nvec = 1; 649 650 /* 651 * iov[1] is the bit of the circular buffer between the start of the 652 * buffer and the start of the currently used section (cb.base) 653 */ 654 if (cbuf_data(&con->cb) >= con->cb.base) { 655 iov[0].iov_len = PAGE_SIZE - cbuf_data(&con->cb); 656 iov[1].iov_len = con->cb.base; 657 iov[1].iov_base = page_address(con->rx_page); 658 nvec = 2; 659 } 660 len = iov[0].iov_len + iov[1].iov_len; 661 662 r = ret = kernel_recvmsg(con->sock, &msg, iov, nvec, len, 663 MSG_DONTWAIT | MSG_NOSIGNAL); 664 if (ret <= 0) 665 goto out_close; 666 else if (ret == len) 667 call_again_soon = 1; 668 669 cbuf_add(&con->cb, ret); 670 ret = dlm_process_incoming_buffer(con->nodeid, 671 page_address(con->rx_page), 672 con->cb.base, con->cb.len, 673 PAGE_SIZE); 674 if (ret == -EBADMSG) { 675 log_print("lowcomms: addr=%p, base=%u, len=%u, read=%d", 676 page_address(con->rx_page), con->cb.base, 677 con->cb.len, r); 678 } 679 if (ret < 0) 680 goto out_close; 681 cbuf_eat(&con->cb, ret); 682 683 if (cbuf_empty(&con->cb) && !call_again_soon) { 684 __free_page(con->rx_page); 685 con->rx_page = NULL; 686 } 687 688 if (call_again_soon) 689 goto out_resched; 690 mutex_unlock(&con->sock_mutex); 691 return 0; 692 693 out_resched: 694 if (!test_and_set_bit(CF_READ_PENDING, &con->flags)) 695 queue_work(recv_workqueue, &con->rwork); 696 mutex_unlock(&con->sock_mutex); 697 return -EAGAIN; 698 699 out_close: 700 mutex_unlock(&con->sock_mutex); 701 if (ret != -EAGAIN) { 702 close_connection(con, false, true, false); 703 /* Reconnect when there is something to send */ 704 } 705 /* Don't return success if we really got EOF */ 706 if (ret == 0) 707 ret = -EAGAIN; 708 709 return ret; 710 } 711 712 /* Listening socket is busy, accept a connection */ 713 static int tcp_accept_from_sock(struct connection *con) 714 { 715 int result; 716 struct sockaddr_storage peeraddr; 717 struct socket *newsock; 718 int len; 719 int nodeid; 720 struct connection *newcon; 721 struct connection *addcon; 722 723 mutex_lock(&connections_lock); 724 if (!dlm_allow_conn) { 725 mutex_unlock(&connections_lock); 726 return -1; 727 } 728 mutex_unlock(&connections_lock); 729 730 memset(&peeraddr, 0, sizeof(peeraddr)); 731 result = sock_create_lite(dlm_local_addr[0]->ss_family, 732 SOCK_STREAM, IPPROTO_TCP, &newsock); 733 if (result < 0) 734 return -ENOMEM; 735 736 mutex_lock_nested(&con->sock_mutex, 0); 737 738 result = -ENOTCONN; 739 if (con->sock == NULL) 740 goto accept_err; 741 742 newsock->type = con->sock->type; 743 newsock->ops = con->sock->ops; 744 745 result = con->sock->ops->accept(con->sock, newsock, O_NONBLOCK, true); 746 if (result < 0) 747 goto accept_err; 748 749 /* Get the connected socket's peer */ 750 memset(&peeraddr, 0, sizeof(peeraddr)); 751 if (newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr, 752 &len, 2)) { 753 result = -ECONNABORTED; 754 goto accept_err; 755 } 756 757 /* Get the new node's NODEID */ 758 make_sockaddr(&peeraddr, 0, &len); 759 if (addr_to_nodeid(&peeraddr, &nodeid)) { 760 unsigned char *b=(unsigned char *)&peeraddr; 761 log_print("connect from non cluster node"); 762 print_hex_dump_bytes("ss: ", DUMP_PREFIX_NONE, 763 b, sizeof(struct sockaddr_storage)); 764 sock_release(newsock); 765 mutex_unlock(&con->sock_mutex); 766 return -1; 767 } 768 769 log_print("got connection from %d", nodeid); 770 771 /* Check to see if we already have a connection to this node. This 772 * could happen if the two nodes initiate a connection at roughly 773 * the same time and the connections cross on the wire. 774 * In this case we store the incoming one in "othercon" 775 */ 776 newcon = nodeid2con(nodeid, GFP_NOFS); 777 if (!newcon) { 778 result = -ENOMEM; 779 goto accept_err; 780 } 781 mutex_lock_nested(&newcon->sock_mutex, 1); 782 if (newcon->sock) { 783 struct connection *othercon = newcon->othercon; 784 785 if (!othercon) { 786 othercon = kmem_cache_zalloc(con_cache, GFP_NOFS); 787 if (!othercon) { 788 log_print("failed to allocate incoming socket"); 789 mutex_unlock(&newcon->sock_mutex); 790 result = -ENOMEM; 791 goto accept_err; 792 } 793 othercon->nodeid = nodeid; 794 othercon->rx_action = receive_from_sock; 795 mutex_init(&othercon->sock_mutex); 796 INIT_WORK(&othercon->swork, process_send_sockets); 797 INIT_WORK(&othercon->rwork, process_recv_sockets); 798 set_bit(CF_IS_OTHERCON, &othercon->flags); 799 } 800 if (!othercon->sock) { 801 newcon->othercon = othercon; 802 othercon->sock = newsock; 803 newsock->sk->sk_user_data = othercon; 804 add_sock(newsock, othercon); 805 addcon = othercon; 806 } 807 else { 808 printk("Extra connection from node %d attempted\n", nodeid); 809 result = -EAGAIN; 810 mutex_unlock(&newcon->sock_mutex); 811 goto accept_err; 812 } 813 } 814 else { 815 newsock->sk->sk_user_data = newcon; 816 newcon->rx_action = receive_from_sock; 817 /* accept copies the sk after we've saved the callbacks, so we 818 don't want to save them a second time or comm errors will 819 result in calling sk_error_report recursively. */ 820 add_sock(newsock, newcon); 821 addcon = newcon; 822 } 823 824 mutex_unlock(&newcon->sock_mutex); 825 826 /* 827 * Add it to the active queue in case we got data 828 * between processing the accept adding the socket 829 * to the read_sockets list 830 */ 831 if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags)) 832 queue_work(recv_workqueue, &addcon->rwork); 833 mutex_unlock(&con->sock_mutex); 834 835 return 0; 836 837 accept_err: 838 mutex_unlock(&con->sock_mutex); 839 sock_release(newsock); 840 841 if (result != -EAGAIN) 842 log_print("error accepting connection from node: %d", result); 843 return result; 844 } 845 846 static int sctp_accept_from_sock(struct connection *con) 847 { 848 /* Check that the new node is in the lockspace */ 849 struct sctp_prim prim; 850 int nodeid; 851 int prim_len, ret; 852 int addr_len; 853 struct connection *newcon; 854 struct connection *addcon; 855 struct socket *newsock; 856 857 mutex_lock(&connections_lock); 858 if (!dlm_allow_conn) { 859 mutex_unlock(&connections_lock); 860 return -1; 861 } 862 mutex_unlock(&connections_lock); 863 864 mutex_lock_nested(&con->sock_mutex, 0); 865 866 ret = kernel_accept(con->sock, &newsock, O_NONBLOCK); 867 if (ret < 0) 868 goto accept_err; 869 870 memset(&prim, 0, sizeof(struct sctp_prim)); 871 prim_len = sizeof(struct sctp_prim); 872 873 ret = kernel_getsockopt(newsock, IPPROTO_SCTP, SCTP_PRIMARY_ADDR, 874 (char *)&prim, &prim_len); 875 if (ret < 0) { 876 log_print("getsockopt/sctp_primary_addr failed: %d", ret); 877 goto accept_err; 878 } 879 880 make_sockaddr(&prim.ssp_addr, 0, &addr_len); 881 ret = addr_to_nodeid(&prim.ssp_addr, &nodeid); 882 if (ret) { 883 unsigned char *b = (unsigned char *)&prim.ssp_addr; 884 885 log_print("reject connect from unknown addr"); 886 print_hex_dump_bytes("ss: ", DUMP_PREFIX_NONE, 887 b, sizeof(struct sockaddr_storage)); 888 goto accept_err; 889 } 890 891 newcon = nodeid2con(nodeid, GFP_NOFS); 892 if (!newcon) { 893 ret = -ENOMEM; 894 goto accept_err; 895 } 896 897 mutex_lock_nested(&newcon->sock_mutex, 1); 898 899 if (newcon->sock) { 900 struct connection *othercon = newcon->othercon; 901 902 if (!othercon) { 903 othercon = kmem_cache_zalloc(con_cache, GFP_NOFS); 904 if (!othercon) { 905 log_print("failed to allocate incoming socket"); 906 mutex_unlock(&newcon->sock_mutex); 907 ret = -ENOMEM; 908 goto accept_err; 909 } 910 othercon->nodeid = nodeid; 911 othercon->rx_action = receive_from_sock; 912 mutex_init(&othercon->sock_mutex); 913 INIT_WORK(&othercon->swork, process_send_sockets); 914 INIT_WORK(&othercon->rwork, process_recv_sockets); 915 set_bit(CF_IS_OTHERCON, &othercon->flags); 916 } 917 if (!othercon->sock) { 918 newcon->othercon = othercon; 919 othercon->sock = newsock; 920 newsock->sk->sk_user_data = othercon; 921 add_sock(newsock, othercon); 922 addcon = othercon; 923 } else { 924 printk("Extra connection from node %d attempted\n", nodeid); 925 ret = -EAGAIN; 926 mutex_unlock(&newcon->sock_mutex); 927 goto accept_err; 928 } 929 } else { 930 newsock->sk->sk_user_data = newcon; 931 newcon->rx_action = receive_from_sock; 932 add_sock(newsock, newcon); 933 addcon = newcon; 934 } 935 936 log_print("connected to %d", nodeid); 937 938 mutex_unlock(&newcon->sock_mutex); 939 940 /* 941 * Add it to the active queue in case we got data 942 * between processing the accept adding the socket 943 * to the read_sockets list 944 */ 945 if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags)) 946 queue_work(recv_workqueue, &addcon->rwork); 947 mutex_unlock(&con->sock_mutex); 948 949 return 0; 950 951 accept_err: 952 mutex_unlock(&con->sock_mutex); 953 if (newsock) 954 sock_release(newsock); 955 if (ret != -EAGAIN) 956 log_print("error accepting connection from node: %d", ret); 957 958 return ret; 959 } 960 961 static void free_entry(struct writequeue_entry *e) 962 { 963 __free_page(e->page); 964 kfree(e); 965 } 966 967 /* 968 * writequeue_entry_complete - try to delete and free write queue entry 969 * @e: write queue entry to try to delete 970 * @completed: bytes completed 971 * 972 * writequeue_lock must be held. 973 */ 974 static void writequeue_entry_complete(struct writequeue_entry *e, int completed) 975 { 976 e->offset += completed; 977 e->len -= completed; 978 979 if (e->len == 0 && e->users == 0) { 980 list_del(&e->list); 981 free_entry(e); 982 } 983 } 984 985 /* 986 * sctp_bind_addrs - bind a SCTP socket to all our addresses 987 */ 988 static int sctp_bind_addrs(struct connection *con, uint16_t port) 989 { 990 struct sockaddr_storage localaddr; 991 int i, addr_len, result = 0; 992 993 for (i = 0; i < dlm_local_count; i++) { 994 memcpy(&localaddr, dlm_local_addr[i], sizeof(localaddr)); 995 make_sockaddr(&localaddr, port, &addr_len); 996 997 if (!i) 998 result = kernel_bind(con->sock, 999 (struct sockaddr *)&localaddr, 1000 addr_len); 1001 else 1002 result = kernel_setsockopt(con->sock, SOL_SCTP, 1003 SCTP_SOCKOPT_BINDX_ADD, 1004 (char *)&localaddr, addr_len); 1005 1006 if (result < 0) { 1007 log_print("Can't bind to %d addr number %d, %d.\n", 1008 port, i + 1, result); 1009 break; 1010 } 1011 } 1012 return result; 1013 } 1014 1015 /* Initiate an SCTP association. 1016 This is a special case of send_to_sock() in that we don't yet have a 1017 peeled-off socket for this association, so we use the listening socket 1018 and add the primary IP address of the remote node. 1019 */ 1020 static void sctp_connect_to_sock(struct connection *con) 1021 { 1022 struct sockaddr_storage daddr; 1023 int one = 1; 1024 int result; 1025 int addr_len; 1026 struct socket *sock; 1027 1028 if (con->nodeid == 0) { 1029 log_print("attempt to connect sock 0 foiled"); 1030 return; 1031 } 1032 1033 mutex_lock(&con->sock_mutex); 1034 1035 /* Some odd races can cause double-connects, ignore them */ 1036 if (con->retries++ > MAX_CONNECT_RETRIES) 1037 goto out; 1038 1039 if (con->sock) { 1040 log_print("node %d already connected.", con->nodeid); 1041 goto out; 1042 } 1043 1044 memset(&daddr, 0, sizeof(daddr)); 1045 result = nodeid_to_addr(con->nodeid, &daddr, NULL, true); 1046 if (result < 0) { 1047 log_print("no address for nodeid %d", con->nodeid); 1048 goto out; 1049 } 1050 1051 /* Create a socket to communicate with */ 1052 result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family, 1053 SOCK_STREAM, IPPROTO_SCTP, &sock); 1054 if (result < 0) 1055 goto socket_err; 1056 1057 sock->sk->sk_user_data = con; 1058 con->rx_action = receive_from_sock; 1059 con->connect_action = sctp_connect_to_sock; 1060 add_sock(sock, con); 1061 1062 /* Bind to all addresses. */ 1063 if (sctp_bind_addrs(con, 0)) 1064 goto bind_err; 1065 1066 make_sockaddr(&daddr, dlm_config.ci_tcp_port, &addr_len); 1067 1068 log_print("connecting to %d", con->nodeid); 1069 1070 /* Turn off Nagle's algorithm */ 1071 kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY, (char *)&one, 1072 sizeof(one)); 1073 1074 result = sock->ops->connect(sock, (struct sockaddr *)&daddr, addr_len, 1075 O_NONBLOCK); 1076 if (result == -EINPROGRESS) 1077 result = 0; 1078 if (result == 0) 1079 goto out; 1080 1081 bind_err: 1082 con->sock = NULL; 1083 sock_release(sock); 1084 1085 socket_err: 1086 /* 1087 * Some errors are fatal and this list might need adjusting. For other 1088 * errors we try again until the max number of retries is reached. 1089 */ 1090 if (result != -EHOSTUNREACH && 1091 result != -ENETUNREACH && 1092 result != -ENETDOWN && 1093 result != -EINVAL && 1094 result != -EPROTONOSUPPORT) { 1095 log_print("connect %d try %d error %d", con->nodeid, 1096 con->retries, result); 1097 mutex_unlock(&con->sock_mutex); 1098 msleep(1000); 1099 lowcomms_connect_sock(con); 1100 return; 1101 } 1102 1103 out: 1104 mutex_unlock(&con->sock_mutex); 1105 } 1106 1107 /* Connect a new socket to its peer */ 1108 static void tcp_connect_to_sock(struct connection *con) 1109 { 1110 struct sockaddr_storage saddr, src_addr; 1111 int addr_len; 1112 struct socket *sock = NULL; 1113 int one = 1; 1114 int result; 1115 1116 if (con->nodeid == 0) { 1117 log_print("attempt to connect sock 0 foiled"); 1118 return; 1119 } 1120 1121 mutex_lock(&con->sock_mutex); 1122 if (con->retries++ > MAX_CONNECT_RETRIES) 1123 goto out; 1124 1125 /* Some odd races can cause double-connects, ignore them */ 1126 if (con->sock) 1127 goto out; 1128 1129 /* Create a socket to communicate with */ 1130 result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family, 1131 SOCK_STREAM, IPPROTO_TCP, &sock); 1132 if (result < 0) 1133 goto out_err; 1134 1135 memset(&saddr, 0, sizeof(saddr)); 1136 result = nodeid_to_addr(con->nodeid, &saddr, NULL, false); 1137 if (result < 0) { 1138 log_print("no address for nodeid %d", con->nodeid); 1139 goto out_err; 1140 } 1141 1142 sock->sk->sk_user_data = con; 1143 con->rx_action = receive_from_sock; 1144 con->connect_action = tcp_connect_to_sock; 1145 add_sock(sock, con); 1146 1147 /* Bind to our cluster-known address connecting to avoid 1148 routing problems */ 1149 memcpy(&src_addr, dlm_local_addr[0], sizeof(src_addr)); 1150 make_sockaddr(&src_addr, 0, &addr_len); 1151 result = sock->ops->bind(sock, (struct sockaddr *) &src_addr, 1152 addr_len); 1153 if (result < 0) { 1154 log_print("could not bind for connect: %d", result); 1155 /* This *may* not indicate a critical error */ 1156 } 1157 1158 make_sockaddr(&saddr, dlm_config.ci_tcp_port, &addr_len); 1159 1160 log_print("connecting to %d", con->nodeid); 1161 1162 /* Turn off Nagle's algorithm */ 1163 kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY, (char *)&one, 1164 sizeof(one)); 1165 1166 result = sock->ops->connect(sock, (struct sockaddr *)&saddr, addr_len, 1167 O_NONBLOCK); 1168 if (result == -EINPROGRESS) 1169 result = 0; 1170 if (result == 0) 1171 goto out; 1172 1173 out_err: 1174 if (con->sock) { 1175 sock_release(con->sock); 1176 con->sock = NULL; 1177 } else if (sock) { 1178 sock_release(sock); 1179 } 1180 /* 1181 * Some errors are fatal and this list might need adjusting. For other 1182 * errors we try again until the max number of retries is reached. 1183 */ 1184 if (result != -EHOSTUNREACH && 1185 result != -ENETUNREACH && 1186 result != -ENETDOWN && 1187 result != -EINVAL && 1188 result != -EPROTONOSUPPORT) { 1189 log_print("connect %d try %d error %d", con->nodeid, 1190 con->retries, result); 1191 mutex_unlock(&con->sock_mutex); 1192 msleep(1000); 1193 lowcomms_connect_sock(con); 1194 return; 1195 } 1196 out: 1197 mutex_unlock(&con->sock_mutex); 1198 return; 1199 } 1200 1201 static struct socket *tcp_create_listen_sock(struct connection *con, 1202 struct sockaddr_storage *saddr) 1203 { 1204 struct socket *sock = NULL; 1205 int result = 0; 1206 int one = 1; 1207 int addr_len; 1208 1209 if (dlm_local_addr[0]->ss_family == AF_INET) 1210 addr_len = sizeof(struct sockaddr_in); 1211 else 1212 addr_len = sizeof(struct sockaddr_in6); 1213 1214 /* Create a socket to communicate with */ 1215 result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family, 1216 SOCK_STREAM, IPPROTO_TCP, &sock); 1217 if (result < 0) { 1218 log_print("Can't create listening comms socket"); 1219 goto create_out; 1220 } 1221 1222 /* Turn off Nagle's algorithm */ 1223 kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY, (char *)&one, 1224 sizeof(one)); 1225 1226 result = kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, 1227 (char *)&one, sizeof(one)); 1228 1229 if (result < 0) { 1230 log_print("Failed to set SO_REUSEADDR on socket: %d", result); 1231 } 1232 sock->sk->sk_user_data = con; 1233 save_listen_callbacks(sock); 1234 con->rx_action = tcp_accept_from_sock; 1235 con->connect_action = tcp_connect_to_sock; 1236 1237 /* Bind to our port */ 1238 make_sockaddr(saddr, dlm_config.ci_tcp_port, &addr_len); 1239 result = sock->ops->bind(sock, (struct sockaddr *) saddr, addr_len); 1240 if (result < 0) { 1241 log_print("Can't bind to port %d", dlm_config.ci_tcp_port); 1242 sock_release(sock); 1243 sock = NULL; 1244 con->sock = NULL; 1245 goto create_out; 1246 } 1247 result = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, 1248 (char *)&one, sizeof(one)); 1249 if (result < 0) { 1250 log_print("Set keepalive failed: %d", result); 1251 } 1252 1253 result = sock->ops->listen(sock, 5); 1254 if (result < 0) { 1255 log_print("Can't listen on port %d", dlm_config.ci_tcp_port); 1256 sock_release(sock); 1257 sock = NULL; 1258 goto create_out; 1259 } 1260 1261 create_out: 1262 return sock; 1263 } 1264 1265 /* Get local addresses */ 1266 static void init_local(void) 1267 { 1268 struct sockaddr_storage sas, *addr; 1269 int i; 1270 1271 dlm_local_count = 0; 1272 for (i = 0; i < DLM_MAX_ADDR_COUNT; i++) { 1273 if (dlm_our_addr(&sas, i)) 1274 break; 1275 1276 addr = kmemdup(&sas, sizeof(*addr), GFP_NOFS); 1277 if (!addr) 1278 break; 1279 dlm_local_addr[dlm_local_count++] = addr; 1280 } 1281 } 1282 1283 /* Initialise SCTP socket and bind to all interfaces */ 1284 static int sctp_listen_for_all(void) 1285 { 1286 struct socket *sock = NULL; 1287 int result = -EINVAL; 1288 struct connection *con = nodeid2con(0, GFP_NOFS); 1289 int bufsize = NEEDED_RMEM; 1290 int one = 1; 1291 1292 if (!con) 1293 return -ENOMEM; 1294 1295 log_print("Using SCTP for communications"); 1296 1297 result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family, 1298 SOCK_STREAM, IPPROTO_SCTP, &sock); 1299 if (result < 0) { 1300 log_print("Can't create comms socket, check SCTP is loaded"); 1301 goto out; 1302 } 1303 1304 result = kernel_setsockopt(sock, SOL_SOCKET, SO_RCVBUFFORCE, 1305 (char *)&bufsize, sizeof(bufsize)); 1306 if (result) 1307 log_print("Error increasing buffer space on socket %d", result); 1308 1309 result = kernel_setsockopt(sock, SOL_SCTP, SCTP_NODELAY, (char *)&one, 1310 sizeof(one)); 1311 if (result < 0) 1312 log_print("Could not set SCTP NODELAY error %d\n", result); 1313 1314 write_lock_bh(&sock->sk->sk_callback_lock); 1315 /* Init con struct */ 1316 sock->sk->sk_user_data = con; 1317 save_listen_callbacks(sock); 1318 con->sock = sock; 1319 con->sock->sk->sk_data_ready = lowcomms_data_ready; 1320 con->rx_action = sctp_accept_from_sock; 1321 con->connect_action = sctp_connect_to_sock; 1322 1323 write_unlock_bh(&sock->sk->sk_callback_lock); 1324 1325 /* Bind to all addresses. */ 1326 if (sctp_bind_addrs(con, dlm_config.ci_tcp_port)) 1327 goto create_delsock; 1328 1329 result = sock->ops->listen(sock, 5); 1330 if (result < 0) { 1331 log_print("Can't set socket listening"); 1332 goto create_delsock; 1333 } 1334 1335 return 0; 1336 1337 create_delsock: 1338 sock_release(sock); 1339 con->sock = NULL; 1340 out: 1341 return result; 1342 } 1343 1344 static int tcp_listen_for_all(void) 1345 { 1346 struct socket *sock = NULL; 1347 struct connection *con = nodeid2con(0, GFP_NOFS); 1348 int result = -EINVAL; 1349 1350 if (!con) 1351 return -ENOMEM; 1352 1353 /* We don't support multi-homed hosts */ 1354 if (dlm_local_addr[1] != NULL) { 1355 log_print("TCP protocol can't handle multi-homed hosts, " 1356 "try SCTP"); 1357 return -EINVAL; 1358 } 1359 1360 log_print("Using TCP for communications"); 1361 1362 sock = tcp_create_listen_sock(con, dlm_local_addr[0]); 1363 if (sock) { 1364 add_sock(sock, con); 1365 result = 0; 1366 } 1367 else { 1368 result = -EADDRINUSE; 1369 } 1370 1371 return result; 1372 } 1373 1374 1375 1376 static struct writequeue_entry *new_writequeue_entry(struct connection *con, 1377 gfp_t allocation) 1378 { 1379 struct writequeue_entry *entry; 1380 1381 entry = kmalloc(sizeof(struct writequeue_entry), allocation); 1382 if (!entry) 1383 return NULL; 1384 1385 entry->page = alloc_page(allocation); 1386 if (!entry->page) { 1387 kfree(entry); 1388 return NULL; 1389 } 1390 1391 entry->offset = 0; 1392 entry->len = 0; 1393 entry->end = 0; 1394 entry->users = 0; 1395 entry->con = con; 1396 1397 return entry; 1398 } 1399 1400 void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc) 1401 { 1402 struct connection *con; 1403 struct writequeue_entry *e; 1404 int offset = 0; 1405 1406 con = nodeid2con(nodeid, allocation); 1407 if (!con) 1408 return NULL; 1409 1410 spin_lock(&con->writequeue_lock); 1411 e = list_entry(con->writequeue.prev, struct writequeue_entry, list); 1412 if ((&e->list == &con->writequeue) || 1413 (PAGE_SIZE - e->end < len)) { 1414 e = NULL; 1415 } else { 1416 offset = e->end; 1417 e->end += len; 1418 e->users++; 1419 } 1420 spin_unlock(&con->writequeue_lock); 1421 1422 if (e) { 1423 got_one: 1424 *ppc = page_address(e->page) + offset; 1425 return e; 1426 } 1427 1428 e = new_writequeue_entry(con, allocation); 1429 if (e) { 1430 spin_lock(&con->writequeue_lock); 1431 offset = e->end; 1432 e->end += len; 1433 e->users++; 1434 list_add_tail(&e->list, &con->writequeue); 1435 spin_unlock(&con->writequeue_lock); 1436 goto got_one; 1437 } 1438 return NULL; 1439 } 1440 1441 void dlm_lowcomms_commit_buffer(void *mh) 1442 { 1443 struct writequeue_entry *e = (struct writequeue_entry *)mh; 1444 struct connection *con = e->con; 1445 int users; 1446 1447 spin_lock(&con->writequeue_lock); 1448 users = --e->users; 1449 if (users) 1450 goto out; 1451 e->len = e->end - e->offset; 1452 spin_unlock(&con->writequeue_lock); 1453 1454 queue_work(send_workqueue, &con->swork); 1455 return; 1456 1457 out: 1458 spin_unlock(&con->writequeue_lock); 1459 return; 1460 } 1461 1462 /* Send a message */ 1463 static void send_to_sock(struct connection *con) 1464 { 1465 int ret = 0; 1466 const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL; 1467 struct writequeue_entry *e; 1468 int len, offset; 1469 int count = 0; 1470 1471 mutex_lock(&con->sock_mutex); 1472 if (con->sock == NULL) 1473 goto out_connect; 1474 1475 spin_lock(&con->writequeue_lock); 1476 for (;;) { 1477 e = list_entry(con->writequeue.next, struct writequeue_entry, 1478 list); 1479 if ((struct list_head *) e == &con->writequeue) 1480 break; 1481 1482 len = e->len; 1483 offset = e->offset; 1484 BUG_ON(len == 0 && e->users == 0); 1485 spin_unlock(&con->writequeue_lock); 1486 1487 ret = 0; 1488 if (len) { 1489 ret = kernel_sendpage(con->sock, e->page, offset, len, 1490 msg_flags); 1491 if (ret == -EAGAIN || ret == 0) { 1492 if (ret == -EAGAIN && 1493 test_bit(SOCKWQ_ASYNC_NOSPACE, &con->sock->flags) && 1494 !test_and_set_bit(CF_APP_LIMITED, &con->flags)) { 1495 /* Notify TCP that we're limited by the 1496 * application window size. 1497 */ 1498 set_bit(SOCK_NOSPACE, &con->sock->flags); 1499 con->sock->sk->sk_write_pending++; 1500 } 1501 cond_resched(); 1502 goto out; 1503 } else if (ret < 0) 1504 goto send_error; 1505 } 1506 1507 /* Don't starve people filling buffers */ 1508 if (++count >= MAX_SEND_MSG_COUNT) { 1509 cond_resched(); 1510 count = 0; 1511 } 1512 1513 spin_lock(&con->writequeue_lock); 1514 writequeue_entry_complete(e, ret); 1515 } 1516 spin_unlock(&con->writequeue_lock); 1517 out: 1518 mutex_unlock(&con->sock_mutex); 1519 return; 1520 1521 send_error: 1522 mutex_unlock(&con->sock_mutex); 1523 close_connection(con, false, false, true); 1524 /* Requeue the send work. When the work daemon runs again, it will try 1525 a new connection, then call this function again. */ 1526 queue_work(send_workqueue, &con->swork); 1527 return; 1528 1529 out_connect: 1530 mutex_unlock(&con->sock_mutex); 1531 queue_work(send_workqueue, &con->swork); 1532 cond_resched(); 1533 } 1534 1535 static void clean_one_writequeue(struct connection *con) 1536 { 1537 struct writequeue_entry *e, *safe; 1538 1539 spin_lock(&con->writequeue_lock); 1540 list_for_each_entry_safe(e, safe, &con->writequeue, list) { 1541 list_del(&e->list); 1542 free_entry(e); 1543 } 1544 spin_unlock(&con->writequeue_lock); 1545 } 1546 1547 /* Called from recovery when it knows that a node has 1548 left the cluster */ 1549 int dlm_lowcomms_close(int nodeid) 1550 { 1551 struct connection *con; 1552 struct dlm_node_addr *na; 1553 1554 log_print("closing connection to node %d", nodeid); 1555 con = nodeid2con(nodeid, 0); 1556 if (con) { 1557 set_bit(CF_CLOSE, &con->flags); 1558 close_connection(con, true, true, true); 1559 clean_one_writequeue(con); 1560 } 1561 1562 spin_lock(&dlm_node_addrs_spin); 1563 na = find_node_addr(nodeid); 1564 if (na) { 1565 list_del(&na->list); 1566 while (na->addr_count--) 1567 kfree(na->addr[na->addr_count]); 1568 kfree(na); 1569 } 1570 spin_unlock(&dlm_node_addrs_spin); 1571 1572 return 0; 1573 } 1574 1575 /* Receive workqueue function */ 1576 static void process_recv_sockets(struct work_struct *work) 1577 { 1578 struct connection *con = container_of(work, struct connection, rwork); 1579 int err; 1580 1581 clear_bit(CF_READ_PENDING, &con->flags); 1582 do { 1583 err = con->rx_action(con); 1584 } while (!err); 1585 } 1586 1587 /* Send workqueue function */ 1588 static void process_send_sockets(struct work_struct *work) 1589 { 1590 struct connection *con = container_of(work, struct connection, swork); 1591 1592 if (con->sock == NULL) /* not mutex protected so check it inside too */ 1593 con->connect_action(con); 1594 if (!list_empty(&con->writequeue)) 1595 send_to_sock(con); 1596 } 1597 1598 1599 /* Discard all entries on the write queues */ 1600 static void clean_writequeues(void) 1601 { 1602 foreach_conn(clean_one_writequeue); 1603 } 1604 1605 static void work_stop(void) 1606 { 1607 destroy_workqueue(recv_workqueue); 1608 destroy_workqueue(send_workqueue); 1609 } 1610 1611 static int work_start(void) 1612 { 1613 recv_workqueue = alloc_workqueue("dlm_recv", 1614 WQ_UNBOUND | WQ_MEM_RECLAIM, 1); 1615 if (!recv_workqueue) { 1616 log_print("can't start dlm_recv"); 1617 return -ENOMEM; 1618 } 1619 1620 send_workqueue = alloc_workqueue("dlm_send", 1621 WQ_UNBOUND | WQ_MEM_RECLAIM, 1); 1622 if (!send_workqueue) { 1623 log_print("can't start dlm_send"); 1624 destroy_workqueue(recv_workqueue); 1625 return -ENOMEM; 1626 } 1627 1628 return 0; 1629 } 1630 1631 static void stop_conn(struct connection *con) 1632 { 1633 con->flags |= 0x0F; 1634 if (con->sock && con->sock->sk) 1635 con->sock->sk->sk_user_data = NULL; 1636 } 1637 1638 static void free_conn(struct connection *con) 1639 { 1640 close_connection(con, true, true, true); 1641 if (con->othercon) 1642 kmem_cache_free(con_cache, con->othercon); 1643 hlist_del(&con->list); 1644 kmem_cache_free(con_cache, con); 1645 } 1646 1647 void dlm_lowcomms_stop(void) 1648 { 1649 /* Set all the flags to prevent any 1650 socket activity. 1651 */ 1652 mutex_lock(&connections_lock); 1653 dlm_allow_conn = 0; 1654 foreach_conn(stop_conn); 1655 clean_writequeues(); 1656 foreach_conn(free_conn); 1657 mutex_unlock(&connections_lock); 1658 1659 work_stop(); 1660 1661 kmem_cache_destroy(con_cache); 1662 } 1663 1664 int dlm_lowcomms_start(void) 1665 { 1666 int error = -EINVAL; 1667 struct connection *con; 1668 int i; 1669 1670 for (i = 0; i < CONN_HASH_SIZE; i++) 1671 INIT_HLIST_HEAD(&connection_hash[i]); 1672 1673 init_local(); 1674 if (!dlm_local_count) { 1675 error = -ENOTCONN; 1676 log_print("no local IP address has been set"); 1677 goto fail; 1678 } 1679 1680 error = -ENOMEM; 1681 con_cache = kmem_cache_create("dlm_conn", sizeof(struct connection), 1682 __alignof__(struct connection), 0, 1683 NULL); 1684 if (!con_cache) 1685 goto fail; 1686 1687 error = work_start(); 1688 if (error) 1689 goto fail_destroy; 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(); 1698 if (error) 1699 goto fail_unlisten; 1700 1701 return 0; 1702 1703 fail_unlisten: 1704 dlm_allow_conn = 0; 1705 con = nodeid2con(0,0); 1706 if (con) { 1707 close_connection(con, false, true, true); 1708 kmem_cache_free(con_cache, con); 1709 } 1710 fail_destroy: 1711 kmem_cache_destroy(con_cache); 1712 fail: 1713 return error; 1714 } 1715 1716 void dlm_lowcomms_exit(void) 1717 { 1718 struct dlm_node_addr *na, *safe; 1719 1720 spin_lock(&dlm_node_addrs_spin); 1721 list_for_each_entry_safe(na, safe, &dlm_node_addrs, list) { 1722 list_del(&na->list); 1723 while (na->addr_count--) 1724 kfree(na->addr[na->addr_count]); 1725 kfree(na); 1726 } 1727 spin_unlock(&dlm_node_addrs_spin); 1728 } 1729