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 <net/sctp/user.h> 55 #include <net/ipv6.h> 56 57 #include "dlm_internal.h" 58 #include "lowcomms.h" 59 #include "midcomms.h" 60 #include "config.h" 61 62 #define NEEDED_RMEM (4*1024*1024) 63 #define CONN_HASH_SIZE 32 64 65 struct cbuf { 66 unsigned int base; 67 unsigned int len; 68 unsigned int mask; 69 }; 70 71 static void cbuf_add(struct cbuf *cb, int n) 72 { 73 cb->len += n; 74 } 75 76 static int cbuf_data(struct cbuf *cb) 77 { 78 return ((cb->base + cb->len) & cb->mask); 79 } 80 81 static void cbuf_init(struct cbuf *cb, int size) 82 { 83 cb->base = cb->len = 0; 84 cb->mask = size-1; 85 } 86 87 static void cbuf_eat(struct cbuf *cb, int n) 88 { 89 cb->len -= n; 90 cb->base += n; 91 cb->base &= cb->mask; 92 } 93 94 static bool cbuf_empty(struct cbuf *cb) 95 { 96 return cb->len == 0; 97 } 98 99 struct connection { 100 struct socket *sock; /* NULL if not connected */ 101 uint32_t nodeid; /* So we know who we are in the list */ 102 struct mutex sock_mutex; 103 unsigned long flags; 104 #define CF_READ_PENDING 1 105 #define CF_WRITE_PENDING 2 106 #define CF_CONNECT_PENDING 3 107 #define CF_INIT_PENDING 4 108 #define CF_IS_OTHERCON 5 109 struct list_head writequeue; /* List of outgoing writequeue_entries */ 110 spinlock_t writequeue_lock; 111 int (*rx_action) (struct connection *); /* What to do when active */ 112 void (*connect_action) (struct connection *); /* What to do to connect */ 113 struct page *rx_page; 114 struct cbuf cb; 115 int retries; 116 #define MAX_CONNECT_RETRIES 3 117 int sctp_assoc; 118 struct hlist_node list; 119 struct connection *othercon; 120 struct work_struct rwork; /* Receive workqueue */ 121 struct work_struct swork; /* Send workqueue */ 122 }; 123 #define sock2con(x) ((struct connection *)(x)->sk_user_data) 124 125 /* An entry waiting to be sent */ 126 struct writequeue_entry { 127 struct list_head list; 128 struct page *page; 129 int offset; 130 int len; 131 int end; 132 int users; 133 struct connection *con; 134 }; 135 136 static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT]; 137 static int dlm_local_count; 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_MUTEX(connections_lock); 145 static struct kmem_cache *con_cache; 146 147 static void process_recv_sockets(struct work_struct *work); 148 static void process_send_sockets(struct work_struct *work); 149 150 151 /* This is deliberately very simple because most clusters have simple 152 sequential nodeids, so we should be able to go straight to a connection 153 struct in the array */ 154 static inline int nodeid_hash(int nodeid) 155 { 156 return nodeid & (CONN_HASH_SIZE-1); 157 } 158 159 static struct connection *__find_con(int nodeid) 160 { 161 int r; 162 struct hlist_node *h; 163 struct connection *con; 164 165 r = nodeid_hash(nodeid); 166 167 hlist_for_each_entry(con, h, &connection_hash[r], list) { 168 if (con->nodeid == nodeid) 169 return con; 170 } 171 return NULL; 172 } 173 174 /* 175 * If 'allocation' is zero then we don't attempt to create a new 176 * connection structure for this node. 177 */ 178 static struct connection *__nodeid2con(int nodeid, gfp_t alloc) 179 { 180 struct connection *con = NULL; 181 int r; 182 183 con = __find_con(nodeid); 184 if (con || !alloc) 185 return con; 186 187 con = kmem_cache_zalloc(con_cache, alloc); 188 if (!con) 189 return NULL; 190 191 r = nodeid_hash(nodeid); 192 hlist_add_head(&con->list, &connection_hash[r]); 193 194 con->nodeid = nodeid; 195 mutex_init(&con->sock_mutex); 196 INIT_LIST_HEAD(&con->writequeue); 197 spin_lock_init(&con->writequeue_lock); 198 INIT_WORK(&con->swork, process_send_sockets); 199 INIT_WORK(&con->rwork, process_recv_sockets); 200 201 /* Setup action pointers for child sockets */ 202 if (con->nodeid) { 203 struct connection *zerocon = __find_con(0); 204 205 con->connect_action = zerocon->connect_action; 206 if (!con->rx_action) 207 con->rx_action = zerocon->rx_action; 208 } 209 210 return con; 211 } 212 213 /* Loop round all connections */ 214 static void foreach_conn(void (*conn_func)(struct connection *c)) 215 { 216 int i; 217 struct hlist_node *h, *n; 218 struct connection *con; 219 220 for (i = 0; i < CONN_HASH_SIZE; i++) { 221 hlist_for_each_entry_safe(con, h, n, &connection_hash[i], list){ 222 conn_func(con); 223 } 224 } 225 } 226 227 static struct connection *nodeid2con(int nodeid, gfp_t allocation) 228 { 229 struct connection *con; 230 231 mutex_lock(&connections_lock); 232 con = __nodeid2con(nodeid, allocation); 233 mutex_unlock(&connections_lock); 234 235 return con; 236 } 237 238 /* This is a bit drastic, but only called when things go wrong */ 239 static struct connection *assoc2con(int assoc_id) 240 { 241 int i; 242 struct hlist_node *h; 243 struct connection *con; 244 245 mutex_lock(&connections_lock); 246 247 for (i = 0 ; i < CONN_HASH_SIZE; i++) { 248 hlist_for_each_entry(con, h, &connection_hash[i], list) { 249 if (con && con->sctp_assoc == assoc_id) { 250 mutex_unlock(&connections_lock); 251 return con; 252 } 253 } 254 } 255 mutex_unlock(&connections_lock); 256 return NULL; 257 } 258 259 static int nodeid_to_addr(int nodeid, struct sockaddr *retaddr) 260 { 261 struct sockaddr_storage addr; 262 int error; 263 264 if (!dlm_local_count) 265 return -1; 266 267 error = dlm_nodeid_to_addr(nodeid, &addr); 268 if (error) 269 return error; 270 271 if (dlm_local_addr[0]->ss_family == AF_INET) { 272 struct sockaddr_in *in4 = (struct sockaddr_in *) &addr; 273 struct sockaddr_in *ret4 = (struct sockaddr_in *) retaddr; 274 ret4->sin_addr.s_addr = in4->sin_addr.s_addr; 275 } else { 276 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) &addr; 277 struct sockaddr_in6 *ret6 = (struct sockaddr_in6 *) retaddr; 278 ipv6_addr_copy(&ret6->sin6_addr, &in6->sin6_addr); 279 } 280 281 return 0; 282 } 283 284 /* Data available on socket or listen socket received a connect */ 285 static void lowcomms_data_ready(struct sock *sk, int count_unused) 286 { 287 struct connection *con = sock2con(sk); 288 if (con && !test_and_set_bit(CF_READ_PENDING, &con->flags)) 289 queue_work(recv_workqueue, &con->rwork); 290 } 291 292 static void lowcomms_write_space(struct sock *sk) 293 { 294 struct connection *con = sock2con(sk); 295 296 if (con && !test_and_set_bit(CF_WRITE_PENDING, &con->flags)) 297 queue_work(send_workqueue, &con->swork); 298 } 299 300 static inline void lowcomms_connect_sock(struct connection *con) 301 { 302 if (!test_and_set_bit(CF_CONNECT_PENDING, &con->flags)) 303 queue_work(send_workqueue, &con->swork); 304 } 305 306 static void lowcomms_state_change(struct sock *sk) 307 { 308 if (sk->sk_state == TCP_ESTABLISHED) 309 lowcomms_write_space(sk); 310 } 311 312 int dlm_lowcomms_connect_node(int nodeid) 313 { 314 struct connection *con; 315 316 if (nodeid == dlm_our_nodeid()) 317 return 0; 318 319 con = nodeid2con(nodeid, GFP_NOFS); 320 if (!con) 321 return -ENOMEM; 322 lowcomms_connect_sock(con); 323 return 0; 324 } 325 326 /* Make a socket active */ 327 static int add_sock(struct socket *sock, struct connection *con) 328 { 329 con->sock = sock; 330 331 /* Install a data_ready callback */ 332 con->sock->sk->sk_data_ready = lowcomms_data_ready; 333 con->sock->sk->sk_write_space = lowcomms_write_space; 334 con->sock->sk->sk_state_change = lowcomms_state_change; 335 con->sock->sk->sk_user_data = con; 336 con->sock->sk->sk_allocation = GFP_NOFS; 337 return 0; 338 } 339 340 /* Add the port number to an IPv6 or 4 sockaddr and return the address 341 length */ 342 static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port, 343 int *addr_len) 344 { 345 saddr->ss_family = dlm_local_addr[0]->ss_family; 346 if (saddr->ss_family == AF_INET) { 347 struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr; 348 in4_addr->sin_port = cpu_to_be16(port); 349 *addr_len = sizeof(struct sockaddr_in); 350 memset(&in4_addr->sin_zero, 0, sizeof(in4_addr->sin_zero)); 351 } else { 352 struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr; 353 in6_addr->sin6_port = cpu_to_be16(port); 354 *addr_len = sizeof(struct sockaddr_in6); 355 } 356 memset((char *)saddr + *addr_len, 0, sizeof(struct sockaddr_storage) - *addr_len); 357 } 358 359 /* Close a remote connection and tidy up */ 360 static void close_connection(struct connection *con, bool and_other) 361 { 362 mutex_lock(&con->sock_mutex); 363 364 if (con->sock) { 365 sock_release(con->sock); 366 con->sock = NULL; 367 } 368 if (con->othercon && and_other) { 369 /* Will only re-enter once. */ 370 close_connection(con->othercon, false); 371 } 372 if (con->rx_page) { 373 __free_page(con->rx_page); 374 con->rx_page = NULL; 375 } 376 377 con->retries = 0; 378 mutex_unlock(&con->sock_mutex); 379 } 380 381 /* We only send shutdown messages to nodes that are not part of the cluster */ 382 static void sctp_send_shutdown(sctp_assoc_t associd) 383 { 384 static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 385 struct msghdr outmessage; 386 struct cmsghdr *cmsg; 387 struct sctp_sndrcvinfo *sinfo; 388 int ret; 389 struct connection *con; 390 391 con = nodeid2con(0,0); 392 BUG_ON(con == NULL); 393 394 outmessage.msg_name = NULL; 395 outmessage.msg_namelen = 0; 396 outmessage.msg_control = outcmsg; 397 outmessage.msg_controllen = sizeof(outcmsg); 398 outmessage.msg_flags = MSG_EOR; 399 400 cmsg = CMSG_FIRSTHDR(&outmessage); 401 cmsg->cmsg_level = IPPROTO_SCTP; 402 cmsg->cmsg_type = SCTP_SNDRCV; 403 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo)); 404 outmessage.msg_controllen = cmsg->cmsg_len; 405 sinfo = CMSG_DATA(cmsg); 406 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo)); 407 408 sinfo->sinfo_flags |= MSG_EOF; 409 sinfo->sinfo_assoc_id = associd; 410 411 ret = kernel_sendmsg(con->sock, &outmessage, NULL, 0, 0); 412 413 if (ret != 0) 414 log_print("send EOF to node failed: %d", ret); 415 } 416 417 static void sctp_init_failed_foreach(struct connection *con) 418 { 419 con->sctp_assoc = 0; 420 if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) { 421 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) 422 queue_work(send_workqueue, &con->swork); 423 } 424 } 425 426 /* INIT failed but we don't know which node... 427 restart INIT on all pending nodes */ 428 static void sctp_init_failed(void) 429 { 430 mutex_lock(&connections_lock); 431 432 foreach_conn(sctp_init_failed_foreach); 433 434 mutex_unlock(&connections_lock); 435 } 436 437 /* Something happened to an association */ 438 static void process_sctp_notification(struct connection *con, 439 struct msghdr *msg, char *buf) 440 { 441 union sctp_notification *sn = (union sctp_notification *)buf; 442 443 if (sn->sn_header.sn_type == SCTP_ASSOC_CHANGE) { 444 switch (sn->sn_assoc_change.sac_state) { 445 446 case SCTP_COMM_UP: 447 case SCTP_RESTART: 448 { 449 /* Check that the new node is in the lockspace */ 450 struct sctp_prim prim; 451 int nodeid; 452 int prim_len, ret; 453 int addr_len; 454 struct connection *new_con; 455 struct file *file; 456 sctp_peeloff_arg_t parg; 457 int parglen = sizeof(parg); 458 459 /* 460 * We get this before any data for an association. 461 * We verify that the node is in the cluster and 462 * then peel off a socket for it. 463 */ 464 if ((int)sn->sn_assoc_change.sac_assoc_id <= 0) { 465 log_print("COMM_UP for invalid assoc ID %d", 466 (int)sn->sn_assoc_change.sac_assoc_id); 467 sctp_init_failed(); 468 return; 469 } 470 memset(&prim, 0, sizeof(struct sctp_prim)); 471 prim_len = sizeof(struct sctp_prim); 472 prim.ssp_assoc_id = sn->sn_assoc_change.sac_assoc_id; 473 474 ret = kernel_getsockopt(con->sock, 475 IPPROTO_SCTP, 476 SCTP_PRIMARY_ADDR, 477 (char*)&prim, 478 &prim_len); 479 if (ret < 0) { 480 log_print("getsockopt/sctp_primary_addr on " 481 "new assoc %d failed : %d", 482 (int)sn->sn_assoc_change.sac_assoc_id, 483 ret); 484 485 /* Retry INIT later */ 486 new_con = assoc2con(sn->sn_assoc_change.sac_assoc_id); 487 if (new_con) 488 clear_bit(CF_CONNECT_PENDING, &con->flags); 489 return; 490 } 491 make_sockaddr(&prim.ssp_addr, 0, &addr_len); 492 if (dlm_addr_to_nodeid(&prim.ssp_addr, &nodeid)) { 493 int i; 494 unsigned char *b=(unsigned char *)&prim.ssp_addr; 495 log_print("reject connect from unknown addr"); 496 for (i=0; i<sizeof(struct sockaddr_storage);i++) 497 printk("%02x ", b[i]); 498 printk("\n"); 499 sctp_send_shutdown(prim.ssp_assoc_id); 500 return; 501 } 502 503 new_con = nodeid2con(nodeid, GFP_NOFS); 504 if (!new_con) 505 return; 506 507 /* Peel off a new sock */ 508 parg.associd = sn->sn_assoc_change.sac_assoc_id; 509 ret = kernel_getsockopt(con->sock, IPPROTO_SCTP, 510 SCTP_SOCKOPT_PEELOFF, 511 (void *)&parg, &parglen); 512 if (ret) { 513 log_print("Can't peel off a socket for " 514 "connection %d to node %d: err=%d\n", 515 parg.associd, nodeid, ret); 516 } 517 file = fget(parg.sd); 518 new_con->sock = SOCKET_I(file->f_dentry->d_inode); 519 add_sock(new_con->sock, new_con); 520 fput(file); 521 put_unused_fd(parg.sd); 522 523 log_print("got new/restarted association %d nodeid %d", 524 (int)sn->sn_assoc_change.sac_assoc_id, nodeid); 525 526 /* Send any pending writes */ 527 clear_bit(CF_CONNECT_PENDING, &new_con->flags); 528 clear_bit(CF_INIT_PENDING, &con->flags); 529 if (!test_and_set_bit(CF_WRITE_PENDING, &new_con->flags)) { 530 queue_work(send_workqueue, &new_con->swork); 531 } 532 if (!test_and_set_bit(CF_READ_PENDING, &new_con->flags)) 533 queue_work(recv_workqueue, &new_con->rwork); 534 } 535 break; 536 537 case SCTP_COMM_LOST: 538 case SCTP_SHUTDOWN_COMP: 539 { 540 con = assoc2con(sn->sn_assoc_change.sac_assoc_id); 541 if (con) { 542 con->sctp_assoc = 0; 543 } 544 } 545 break; 546 547 /* We don't know which INIT failed, so clear the PENDING flags 548 * on them all. if assoc_id is zero then it will then try 549 * again */ 550 551 case SCTP_CANT_STR_ASSOC: 552 { 553 log_print("Can't start SCTP association - retrying"); 554 sctp_init_failed(); 555 } 556 break; 557 558 default: 559 log_print("unexpected SCTP assoc change id=%d state=%d", 560 (int)sn->sn_assoc_change.sac_assoc_id, 561 sn->sn_assoc_change.sac_state); 562 } 563 } 564 } 565 566 /* Data received from remote end */ 567 static int receive_from_sock(struct connection *con) 568 { 569 int ret = 0; 570 struct msghdr msg = {}; 571 struct kvec iov[2]; 572 unsigned len; 573 int r; 574 int call_again_soon = 0; 575 int nvec; 576 char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 577 578 mutex_lock(&con->sock_mutex); 579 580 if (con->sock == NULL) { 581 ret = -EAGAIN; 582 goto out_close; 583 } 584 585 if (con->rx_page == NULL) { 586 /* 587 * This doesn't need to be atomic, but I think it should 588 * improve performance if it is. 589 */ 590 con->rx_page = alloc_page(GFP_ATOMIC); 591 if (con->rx_page == NULL) 592 goto out_resched; 593 cbuf_init(&con->cb, PAGE_CACHE_SIZE); 594 } 595 596 /* Only SCTP needs these really */ 597 memset(&incmsg, 0, sizeof(incmsg)); 598 msg.msg_control = incmsg; 599 msg.msg_controllen = sizeof(incmsg); 600 601 /* 602 * iov[0] is the bit of the circular buffer between the current end 603 * point (cb.base + cb.len) and the end of the buffer. 604 */ 605 iov[0].iov_len = con->cb.base - cbuf_data(&con->cb); 606 iov[0].iov_base = page_address(con->rx_page) + cbuf_data(&con->cb); 607 iov[1].iov_len = 0; 608 nvec = 1; 609 610 /* 611 * iov[1] is the bit of the circular buffer between the start of the 612 * buffer and the start of the currently used section (cb.base) 613 */ 614 if (cbuf_data(&con->cb) >= con->cb.base) { 615 iov[0].iov_len = PAGE_CACHE_SIZE - cbuf_data(&con->cb); 616 iov[1].iov_len = con->cb.base; 617 iov[1].iov_base = page_address(con->rx_page); 618 nvec = 2; 619 } 620 len = iov[0].iov_len + iov[1].iov_len; 621 622 r = ret = kernel_recvmsg(con->sock, &msg, iov, nvec, len, 623 MSG_DONTWAIT | MSG_NOSIGNAL); 624 if (ret <= 0) 625 goto out_close; 626 627 /* Process SCTP notifications */ 628 if (msg.msg_flags & MSG_NOTIFICATION) { 629 msg.msg_control = incmsg; 630 msg.msg_controllen = sizeof(incmsg); 631 632 process_sctp_notification(con, &msg, 633 page_address(con->rx_page) + con->cb.base); 634 mutex_unlock(&con->sock_mutex); 635 return 0; 636 } 637 BUG_ON(con->nodeid == 0); 638 639 if (ret == len) 640 call_again_soon = 1; 641 cbuf_add(&con->cb, ret); 642 ret = dlm_process_incoming_buffer(con->nodeid, 643 page_address(con->rx_page), 644 con->cb.base, con->cb.len, 645 PAGE_CACHE_SIZE); 646 if (ret == -EBADMSG) { 647 log_print("lowcomms: addr=%p, base=%u, len=%u, " 648 "iov_len=%u, iov_base[0]=%p, read=%d", 649 page_address(con->rx_page), con->cb.base, con->cb.len, 650 len, iov[0].iov_base, r); 651 } 652 if (ret < 0) 653 goto out_close; 654 cbuf_eat(&con->cb, ret); 655 656 if (cbuf_empty(&con->cb) && !call_again_soon) { 657 __free_page(con->rx_page); 658 con->rx_page = NULL; 659 } 660 661 if (call_again_soon) 662 goto out_resched; 663 mutex_unlock(&con->sock_mutex); 664 return 0; 665 666 out_resched: 667 if (!test_and_set_bit(CF_READ_PENDING, &con->flags)) 668 queue_work(recv_workqueue, &con->rwork); 669 mutex_unlock(&con->sock_mutex); 670 return -EAGAIN; 671 672 out_close: 673 mutex_unlock(&con->sock_mutex); 674 if (ret != -EAGAIN) { 675 close_connection(con, false); 676 /* Reconnect when there is something to send */ 677 } 678 /* Don't return success if we really got EOF */ 679 if (ret == 0) 680 ret = -EAGAIN; 681 682 return ret; 683 } 684 685 /* Listening socket is busy, accept a connection */ 686 static int tcp_accept_from_sock(struct connection *con) 687 { 688 int result; 689 struct sockaddr_storage peeraddr; 690 struct socket *newsock; 691 int len; 692 int nodeid; 693 struct connection *newcon; 694 struct connection *addcon; 695 696 memset(&peeraddr, 0, sizeof(peeraddr)); 697 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 698 IPPROTO_TCP, &newsock); 699 if (result < 0) 700 return -ENOMEM; 701 702 mutex_lock_nested(&con->sock_mutex, 0); 703 704 result = -ENOTCONN; 705 if (con->sock == NULL) 706 goto accept_err; 707 708 newsock->type = con->sock->type; 709 newsock->ops = con->sock->ops; 710 711 result = con->sock->ops->accept(con->sock, newsock, O_NONBLOCK); 712 if (result < 0) 713 goto accept_err; 714 715 /* Get the connected socket's peer */ 716 memset(&peeraddr, 0, sizeof(peeraddr)); 717 if (newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr, 718 &len, 2)) { 719 result = -ECONNABORTED; 720 goto accept_err; 721 } 722 723 /* Get the new node's NODEID */ 724 make_sockaddr(&peeraddr, 0, &len); 725 if (dlm_addr_to_nodeid(&peeraddr, &nodeid)) { 726 log_print("connect from non cluster node"); 727 sock_release(newsock); 728 mutex_unlock(&con->sock_mutex); 729 return -1; 730 } 731 732 log_print("got connection from %d", nodeid); 733 734 /* Check to see if we already have a connection to this node. This 735 * could happen if the two nodes initiate a connection at roughly 736 * the same time and the connections cross on the wire. 737 * In this case we store the incoming one in "othercon" 738 */ 739 newcon = nodeid2con(nodeid, GFP_NOFS); 740 if (!newcon) { 741 result = -ENOMEM; 742 goto accept_err; 743 } 744 mutex_lock_nested(&newcon->sock_mutex, 1); 745 if (newcon->sock) { 746 struct connection *othercon = newcon->othercon; 747 748 if (!othercon) { 749 othercon = kmem_cache_zalloc(con_cache, GFP_NOFS); 750 if (!othercon) { 751 log_print("failed to allocate incoming socket"); 752 mutex_unlock(&newcon->sock_mutex); 753 result = -ENOMEM; 754 goto accept_err; 755 } 756 othercon->nodeid = nodeid; 757 othercon->rx_action = receive_from_sock; 758 mutex_init(&othercon->sock_mutex); 759 INIT_WORK(&othercon->swork, process_send_sockets); 760 INIT_WORK(&othercon->rwork, process_recv_sockets); 761 set_bit(CF_IS_OTHERCON, &othercon->flags); 762 } 763 if (!othercon->sock) { 764 newcon->othercon = othercon; 765 othercon->sock = newsock; 766 newsock->sk->sk_user_data = othercon; 767 add_sock(newsock, othercon); 768 addcon = othercon; 769 } 770 else { 771 printk("Extra connection from node %d attempted\n", nodeid); 772 result = -EAGAIN; 773 mutex_unlock(&newcon->sock_mutex); 774 goto accept_err; 775 } 776 } 777 else { 778 newsock->sk->sk_user_data = newcon; 779 newcon->rx_action = receive_from_sock; 780 add_sock(newsock, newcon); 781 addcon = newcon; 782 } 783 784 mutex_unlock(&newcon->sock_mutex); 785 786 /* 787 * Add it to the active queue in case we got data 788 * beween processing the accept adding the socket 789 * to the read_sockets list 790 */ 791 if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags)) 792 queue_work(recv_workqueue, &addcon->rwork); 793 mutex_unlock(&con->sock_mutex); 794 795 return 0; 796 797 accept_err: 798 mutex_unlock(&con->sock_mutex); 799 sock_release(newsock); 800 801 if (result != -EAGAIN) 802 log_print("error accepting connection from node: %d", result); 803 return result; 804 } 805 806 static void free_entry(struct writequeue_entry *e) 807 { 808 __free_page(e->page); 809 kfree(e); 810 } 811 812 /* Initiate an SCTP association. 813 This is a special case of send_to_sock() in that we don't yet have a 814 peeled-off socket for this association, so we use the listening socket 815 and add the primary IP address of the remote node. 816 */ 817 static void sctp_init_assoc(struct connection *con) 818 { 819 struct sockaddr_storage rem_addr; 820 char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 821 struct msghdr outmessage; 822 struct cmsghdr *cmsg; 823 struct sctp_sndrcvinfo *sinfo; 824 struct connection *base_con; 825 struct writequeue_entry *e; 826 int len, offset; 827 int ret; 828 int addrlen; 829 struct kvec iov[1]; 830 831 if (test_and_set_bit(CF_INIT_PENDING, &con->flags)) 832 return; 833 834 if (con->retries++ > MAX_CONNECT_RETRIES) 835 return; 836 837 log_print("Initiating association with node %d", con->nodeid); 838 839 if (nodeid_to_addr(con->nodeid, (struct sockaddr *)&rem_addr)) { 840 log_print("no address for nodeid %d", con->nodeid); 841 return; 842 } 843 base_con = nodeid2con(0, 0); 844 BUG_ON(base_con == NULL); 845 846 make_sockaddr(&rem_addr, dlm_config.ci_tcp_port, &addrlen); 847 848 outmessage.msg_name = &rem_addr; 849 outmessage.msg_namelen = addrlen; 850 outmessage.msg_control = outcmsg; 851 outmessage.msg_controllen = sizeof(outcmsg); 852 outmessage.msg_flags = MSG_EOR; 853 854 spin_lock(&con->writequeue_lock); 855 e = list_entry(con->writequeue.next, struct writequeue_entry, 856 list); 857 858 BUG_ON((struct list_head *) e == &con->writequeue); 859 860 len = e->len; 861 offset = e->offset; 862 spin_unlock(&con->writequeue_lock); 863 864 /* Send the first block off the write queue */ 865 iov[0].iov_base = page_address(e->page)+offset; 866 iov[0].iov_len = len; 867 868 cmsg = CMSG_FIRSTHDR(&outmessage); 869 cmsg->cmsg_level = IPPROTO_SCTP; 870 cmsg->cmsg_type = SCTP_SNDRCV; 871 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo)); 872 sinfo = CMSG_DATA(cmsg); 873 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo)); 874 sinfo->sinfo_ppid = cpu_to_le32(dlm_our_nodeid()); 875 outmessage.msg_controllen = cmsg->cmsg_len; 876 877 ret = kernel_sendmsg(base_con->sock, &outmessage, iov, 1, len); 878 if (ret < 0) { 879 log_print("Send first packet to node %d failed: %d", 880 con->nodeid, ret); 881 882 /* Try again later */ 883 clear_bit(CF_CONNECT_PENDING, &con->flags); 884 clear_bit(CF_INIT_PENDING, &con->flags); 885 } 886 else { 887 spin_lock(&con->writequeue_lock); 888 e->offset += ret; 889 e->len -= ret; 890 891 if (e->len == 0 && e->users == 0) { 892 list_del(&e->list); 893 free_entry(e); 894 } 895 spin_unlock(&con->writequeue_lock); 896 } 897 } 898 899 /* Connect a new socket to its peer */ 900 static void tcp_connect_to_sock(struct connection *con) 901 { 902 int result = -EHOSTUNREACH; 903 struct sockaddr_storage saddr, src_addr; 904 int addr_len; 905 struct socket *sock = NULL; 906 907 if (con->nodeid == 0) { 908 log_print("attempt to connect sock 0 foiled"); 909 return; 910 } 911 912 mutex_lock(&con->sock_mutex); 913 if (con->retries++ > MAX_CONNECT_RETRIES) 914 goto out; 915 916 /* Some odd races can cause double-connects, ignore them */ 917 if (con->sock) { 918 result = 0; 919 goto out; 920 } 921 922 /* Create a socket to communicate with */ 923 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 924 IPPROTO_TCP, &sock); 925 if (result < 0) 926 goto out_err; 927 928 memset(&saddr, 0, sizeof(saddr)); 929 if (dlm_nodeid_to_addr(con->nodeid, &saddr)) 930 goto out_err; 931 932 sock->sk->sk_user_data = con; 933 con->rx_action = receive_from_sock; 934 con->connect_action = tcp_connect_to_sock; 935 add_sock(sock, con); 936 937 /* Bind to our cluster-known address connecting to avoid 938 routing problems */ 939 memcpy(&src_addr, dlm_local_addr[0], sizeof(src_addr)); 940 make_sockaddr(&src_addr, 0, &addr_len); 941 result = sock->ops->bind(sock, (struct sockaddr *) &src_addr, 942 addr_len); 943 if (result < 0) { 944 log_print("could not bind for connect: %d", result); 945 /* This *may* not indicate a critical error */ 946 } 947 948 make_sockaddr(&saddr, dlm_config.ci_tcp_port, &addr_len); 949 950 log_print("connecting to %d", con->nodeid); 951 result = 952 sock->ops->connect(sock, (struct sockaddr *)&saddr, addr_len, 953 O_NONBLOCK); 954 if (result == -EINPROGRESS) 955 result = 0; 956 if (result == 0) 957 goto out; 958 959 out_err: 960 if (con->sock) { 961 sock_release(con->sock); 962 con->sock = NULL; 963 } else if (sock) { 964 sock_release(sock); 965 } 966 /* 967 * Some errors are fatal and this list might need adjusting. For other 968 * errors we try again until the max number of retries is reached. 969 */ 970 if (result != -EHOSTUNREACH && result != -ENETUNREACH && 971 result != -ENETDOWN && result != -EINVAL 972 && result != -EPROTONOSUPPORT) { 973 lowcomms_connect_sock(con); 974 result = 0; 975 } 976 out: 977 mutex_unlock(&con->sock_mutex); 978 return; 979 } 980 981 static struct socket *tcp_create_listen_sock(struct connection *con, 982 struct sockaddr_storage *saddr) 983 { 984 struct socket *sock = NULL; 985 int result = 0; 986 int one = 1; 987 int addr_len; 988 989 if (dlm_local_addr[0]->ss_family == AF_INET) 990 addr_len = sizeof(struct sockaddr_in); 991 else 992 addr_len = sizeof(struct sockaddr_in6); 993 994 /* Create a socket to communicate with */ 995 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 996 IPPROTO_TCP, &sock); 997 if (result < 0) { 998 log_print("Can't create listening comms socket"); 999 goto create_out; 1000 } 1001 1002 result = kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, 1003 (char *)&one, sizeof(one)); 1004 1005 if (result < 0) { 1006 log_print("Failed to set SO_REUSEADDR on socket: %d", result); 1007 } 1008 sock->sk->sk_user_data = con; 1009 con->rx_action = tcp_accept_from_sock; 1010 con->connect_action = tcp_connect_to_sock; 1011 con->sock = sock; 1012 1013 /* Bind to our port */ 1014 make_sockaddr(saddr, dlm_config.ci_tcp_port, &addr_len); 1015 result = sock->ops->bind(sock, (struct sockaddr *) saddr, addr_len); 1016 if (result < 0) { 1017 log_print("Can't bind to port %d", dlm_config.ci_tcp_port); 1018 sock_release(sock); 1019 sock = NULL; 1020 con->sock = NULL; 1021 goto create_out; 1022 } 1023 result = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, 1024 (char *)&one, sizeof(one)); 1025 if (result < 0) { 1026 log_print("Set keepalive failed: %d", result); 1027 } 1028 1029 result = sock->ops->listen(sock, 5); 1030 if (result < 0) { 1031 log_print("Can't listen on port %d", dlm_config.ci_tcp_port); 1032 sock_release(sock); 1033 sock = NULL; 1034 goto create_out; 1035 } 1036 1037 create_out: 1038 return sock; 1039 } 1040 1041 /* Get local addresses */ 1042 static void init_local(void) 1043 { 1044 struct sockaddr_storage sas, *addr; 1045 int i; 1046 1047 dlm_local_count = 0; 1048 for (i = 0; i < DLM_MAX_ADDR_COUNT - 1; i++) { 1049 if (dlm_our_addr(&sas, i)) 1050 break; 1051 1052 addr = kmalloc(sizeof(*addr), GFP_KERNEL); 1053 if (!addr) 1054 break; 1055 memcpy(addr, &sas, sizeof(*addr)); 1056 dlm_local_addr[dlm_local_count++] = addr; 1057 } 1058 } 1059 1060 /* Bind to an IP address. SCTP allows multiple address so it can do 1061 multi-homing */ 1062 static int add_sctp_bind_addr(struct connection *sctp_con, 1063 struct sockaddr_storage *addr, 1064 int addr_len, int num) 1065 { 1066 int result = 0; 1067 1068 if (num == 1) 1069 result = kernel_bind(sctp_con->sock, 1070 (struct sockaddr *) addr, 1071 addr_len); 1072 else 1073 result = kernel_setsockopt(sctp_con->sock, SOL_SCTP, 1074 SCTP_SOCKOPT_BINDX_ADD, 1075 (char *)addr, addr_len); 1076 1077 if (result < 0) 1078 log_print("Can't bind to port %d addr number %d", 1079 dlm_config.ci_tcp_port, num); 1080 1081 return result; 1082 } 1083 1084 /* Initialise SCTP socket and bind to all interfaces */ 1085 static int sctp_listen_for_all(void) 1086 { 1087 struct socket *sock = NULL; 1088 struct sockaddr_storage localaddr; 1089 struct sctp_event_subscribe subscribe; 1090 int result = -EINVAL, num = 1, i, addr_len; 1091 struct connection *con = nodeid2con(0, GFP_KERNEL); 1092 int bufsize = NEEDED_RMEM; 1093 1094 if (!con) 1095 return -ENOMEM; 1096 1097 log_print("Using SCTP for communications"); 1098 1099 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_SEQPACKET, 1100 IPPROTO_SCTP, &sock); 1101 if (result < 0) { 1102 log_print("Can't create comms socket, check SCTP is loaded"); 1103 goto out; 1104 } 1105 1106 /* Listen for events */ 1107 memset(&subscribe, 0, sizeof(subscribe)); 1108 subscribe.sctp_data_io_event = 1; 1109 subscribe.sctp_association_event = 1; 1110 subscribe.sctp_send_failure_event = 1; 1111 subscribe.sctp_shutdown_event = 1; 1112 subscribe.sctp_partial_delivery_event = 1; 1113 1114 result = kernel_setsockopt(sock, SOL_SOCKET, SO_RCVBUFFORCE, 1115 (char *)&bufsize, sizeof(bufsize)); 1116 if (result) 1117 log_print("Error increasing buffer space on socket %d", result); 1118 1119 result = kernel_setsockopt(sock, SOL_SCTP, SCTP_EVENTS, 1120 (char *)&subscribe, sizeof(subscribe)); 1121 if (result < 0) { 1122 log_print("Failed to set SCTP_EVENTS on socket: result=%d", 1123 result); 1124 goto create_delsock; 1125 } 1126 1127 /* Init con struct */ 1128 sock->sk->sk_user_data = con; 1129 con->sock = sock; 1130 con->sock->sk->sk_data_ready = lowcomms_data_ready; 1131 con->rx_action = receive_from_sock; 1132 con->connect_action = sctp_init_assoc; 1133 1134 /* Bind to all interfaces. */ 1135 for (i = 0; i < dlm_local_count; i++) { 1136 memcpy(&localaddr, dlm_local_addr[i], sizeof(localaddr)); 1137 make_sockaddr(&localaddr, dlm_config.ci_tcp_port, &addr_len); 1138 1139 result = add_sctp_bind_addr(con, &localaddr, addr_len, num); 1140 if (result) 1141 goto create_delsock; 1142 ++num; 1143 } 1144 1145 result = sock->ops->listen(sock, 5); 1146 if (result < 0) { 1147 log_print("Can't set socket listening"); 1148 goto create_delsock; 1149 } 1150 1151 return 0; 1152 1153 create_delsock: 1154 sock_release(sock); 1155 con->sock = NULL; 1156 out: 1157 return result; 1158 } 1159 1160 static int tcp_listen_for_all(void) 1161 { 1162 struct socket *sock = NULL; 1163 struct connection *con = nodeid2con(0, GFP_KERNEL); 1164 int result = -EINVAL; 1165 1166 if (!con) 1167 return -ENOMEM; 1168 1169 /* We don't support multi-homed hosts */ 1170 if (dlm_local_addr[1] != NULL) { 1171 log_print("TCP protocol can't handle multi-homed hosts, " 1172 "try SCTP"); 1173 return -EINVAL; 1174 } 1175 1176 log_print("Using TCP for communications"); 1177 1178 sock = tcp_create_listen_sock(con, dlm_local_addr[0]); 1179 if (sock) { 1180 add_sock(sock, con); 1181 result = 0; 1182 } 1183 else { 1184 result = -EADDRINUSE; 1185 } 1186 1187 return result; 1188 } 1189 1190 1191 1192 static struct writequeue_entry *new_writequeue_entry(struct connection *con, 1193 gfp_t allocation) 1194 { 1195 struct writequeue_entry *entry; 1196 1197 entry = kmalloc(sizeof(struct writequeue_entry), allocation); 1198 if (!entry) 1199 return NULL; 1200 1201 entry->page = alloc_page(allocation); 1202 if (!entry->page) { 1203 kfree(entry); 1204 return NULL; 1205 } 1206 1207 entry->offset = 0; 1208 entry->len = 0; 1209 entry->end = 0; 1210 entry->users = 0; 1211 entry->con = con; 1212 1213 return entry; 1214 } 1215 1216 void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc) 1217 { 1218 struct connection *con; 1219 struct writequeue_entry *e; 1220 int offset = 0; 1221 int users = 0; 1222 1223 con = nodeid2con(nodeid, allocation); 1224 if (!con) 1225 return NULL; 1226 1227 spin_lock(&con->writequeue_lock); 1228 e = list_entry(con->writequeue.prev, struct writequeue_entry, list); 1229 if ((&e->list == &con->writequeue) || 1230 (PAGE_CACHE_SIZE - e->end < len)) { 1231 e = NULL; 1232 } else { 1233 offset = e->end; 1234 e->end += len; 1235 users = e->users++; 1236 } 1237 spin_unlock(&con->writequeue_lock); 1238 1239 if (e) { 1240 got_one: 1241 *ppc = page_address(e->page) + offset; 1242 return e; 1243 } 1244 1245 e = new_writequeue_entry(con, allocation); 1246 if (e) { 1247 spin_lock(&con->writequeue_lock); 1248 offset = e->end; 1249 e->end += len; 1250 users = e->users++; 1251 list_add_tail(&e->list, &con->writequeue); 1252 spin_unlock(&con->writequeue_lock); 1253 goto got_one; 1254 } 1255 return NULL; 1256 } 1257 1258 void dlm_lowcomms_commit_buffer(void *mh) 1259 { 1260 struct writequeue_entry *e = (struct writequeue_entry *)mh; 1261 struct connection *con = e->con; 1262 int users; 1263 1264 spin_lock(&con->writequeue_lock); 1265 users = --e->users; 1266 if (users) 1267 goto out; 1268 e->len = e->end - e->offset; 1269 spin_unlock(&con->writequeue_lock); 1270 1271 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) { 1272 queue_work(send_workqueue, &con->swork); 1273 } 1274 return; 1275 1276 out: 1277 spin_unlock(&con->writequeue_lock); 1278 return; 1279 } 1280 1281 /* Send a message */ 1282 static void send_to_sock(struct connection *con) 1283 { 1284 int ret = 0; 1285 ssize_t(*sendpage) (struct socket *, struct page *, int, size_t, int); 1286 const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL; 1287 struct writequeue_entry *e; 1288 int len, offset; 1289 1290 mutex_lock(&con->sock_mutex); 1291 if (con->sock == NULL) 1292 goto out_connect; 1293 1294 sendpage = con->sock->ops->sendpage; 1295 1296 spin_lock(&con->writequeue_lock); 1297 for (;;) { 1298 e = list_entry(con->writequeue.next, struct writequeue_entry, 1299 list); 1300 if ((struct list_head *) e == &con->writequeue) 1301 break; 1302 1303 len = e->len; 1304 offset = e->offset; 1305 BUG_ON(len == 0 && e->users == 0); 1306 spin_unlock(&con->writequeue_lock); 1307 1308 ret = 0; 1309 if (len) { 1310 ret = sendpage(con->sock, e->page, offset, len, 1311 msg_flags); 1312 if (ret == -EAGAIN || ret == 0) { 1313 cond_resched(); 1314 goto out; 1315 } 1316 if (ret <= 0) 1317 goto send_error; 1318 } 1319 /* Don't starve people filling buffers */ 1320 cond_resched(); 1321 1322 spin_lock(&con->writequeue_lock); 1323 e->offset += ret; 1324 e->len -= ret; 1325 1326 if (e->len == 0 && e->users == 0) { 1327 list_del(&e->list); 1328 free_entry(e); 1329 continue; 1330 } 1331 } 1332 spin_unlock(&con->writequeue_lock); 1333 out: 1334 mutex_unlock(&con->sock_mutex); 1335 return; 1336 1337 send_error: 1338 mutex_unlock(&con->sock_mutex); 1339 close_connection(con, false); 1340 lowcomms_connect_sock(con); 1341 return; 1342 1343 out_connect: 1344 mutex_unlock(&con->sock_mutex); 1345 if (!test_bit(CF_INIT_PENDING, &con->flags)) 1346 lowcomms_connect_sock(con); 1347 return; 1348 } 1349 1350 static void clean_one_writequeue(struct connection *con) 1351 { 1352 struct writequeue_entry *e, *safe; 1353 1354 spin_lock(&con->writequeue_lock); 1355 list_for_each_entry_safe(e, safe, &con->writequeue, list) { 1356 list_del(&e->list); 1357 free_entry(e); 1358 } 1359 spin_unlock(&con->writequeue_lock); 1360 } 1361 1362 /* Called from recovery when it knows that a node has 1363 left the cluster */ 1364 int dlm_lowcomms_close(int nodeid) 1365 { 1366 struct connection *con; 1367 1368 log_print("closing connection to node %d", nodeid); 1369 con = nodeid2con(nodeid, 0); 1370 if (con) { 1371 clean_one_writequeue(con); 1372 close_connection(con, true); 1373 } 1374 return 0; 1375 } 1376 1377 /* Receive workqueue function */ 1378 static void process_recv_sockets(struct work_struct *work) 1379 { 1380 struct connection *con = container_of(work, struct connection, rwork); 1381 int err; 1382 1383 clear_bit(CF_READ_PENDING, &con->flags); 1384 do { 1385 err = con->rx_action(con); 1386 } while (!err); 1387 } 1388 1389 /* Send workqueue function */ 1390 static void process_send_sockets(struct work_struct *work) 1391 { 1392 struct connection *con = container_of(work, struct connection, swork); 1393 1394 if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) { 1395 con->connect_action(con); 1396 } 1397 clear_bit(CF_WRITE_PENDING, &con->flags); 1398 send_to_sock(con); 1399 } 1400 1401 1402 /* Discard all entries on the write queues */ 1403 static void clean_writequeues(void) 1404 { 1405 foreach_conn(clean_one_writequeue); 1406 } 1407 1408 static void work_stop(void) 1409 { 1410 destroy_workqueue(recv_workqueue); 1411 destroy_workqueue(send_workqueue); 1412 } 1413 1414 static int work_start(void) 1415 { 1416 int error; 1417 recv_workqueue = create_workqueue("dlm_recv"); 1418 error = IS_ERR(recv_workqueue); 1419 if (error) { 1420 log_print("can't start dlm_recv %d", error); 1421 return error; 1422 } 1423 1424 send_workqueue = create_singlethread_workqueue("dlm_send"); 1425 error = IS_ERR(send_workqueue); 1426 if (error) { 1427 log_print("can't start dlm_send %d", error); 1428 destroy_workqueue(recv_workqueue); 1429 return error; 1430 } 1431 1432 return 0; 1433 } 1434 1435 static void stop_conn(struct connection *con) 1436 { 1437 con->flags |= 0x0F; 1438 if (con->sock && con->sock->sk) 1439 con->sock->sk->sk_user_data = NULL; 1440 } 1441 1442 static void free_conn(struct connection *con) 1443 { 1444 close_connection(con, true); 1445 if (con->othercon) 1446 kmem_cache_free(con_cache, con->othercon); 1447 hlist_del(&con->list); 1448 kmem_cache_free(con_cache, con); 1449 } 1450 1451 void dlm_lowcomms_stop(void) 1452 { 1453 /* Set all the flags to prevent any 1454 socket activity. 1455 */ 1456 mutex_lock(&connections_lock); 1457 foreach_conn(stop_conn); 1458 mutex_unlock(&connections_lock); 1459 1460 work_stop(); 1461 1462 mutex_lock(&connections_lock); 1463 clean_writequeues(); 1464 1465 foreach_conn(free_conn); 1466 1467 mutex_unlock(&connections_lock); 1468 kmem_cache_destroy(con_cache); 1469 } 1470 1471 int dlm_lowcomms_start(void) 1472 { 1473 int error = -EINVAL; 1474 struct connection *con; 1475 int i; 1476 1477 for (i = 0; i < CONN_HASH_SIZE; i++) 1478 INIT_HLIST_HEAD(&connection_hash[i]); 1479 1480 init_local(); 1481 if (!dlm_local_count) { 1482 error = -ENOTCONN; 1483 log_print("no local IP address has been set"); 1484 goto out; 1485 } 1486 1487 error = -ENOMEM; 1488 con_cache = kmem_cache_create("dlm_conn", sizeof(struct connection), 1489 __alignof__(struct connection), 0, 1490 NULL); 1491 if (!con_cache) 1492 goto out; 1493 1494 /* Start listening */ 1495 if (dlm_config.ci_protocol == 0) 1496 error = tcp_listen_for_all(); 1497 else 1498 error = sctp_listen_for_all(); 1499 if (error) 1500 goto fail_unlisten; 1501 1502 error = work_start(); 1503 if (error) 1504 goto fail_unlisten; 1505 1506 return 0; 1507 1508 fail_unlisten: 1509 con = nodeid2con(0,0); 1510 if (con) { 1511 close_connection(con, false); 1512 kmem_cache_free(con_cache, con); 1513 } 1514 kmem_cache_destroy(con_cache); 1515 1516 out: 1517 return error; 1518 } 1519