1 /****************************************************************************** 2 ******************************************************************************* 3 ** 4 ** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. 5 ** Copyright (C) 2004-2007 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 it's 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 wither 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 shouldbe 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/idr.h> 52 #include <linux/file.h> 53 #include <linux/sctp.h> 54 #include <net/sctp/user.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 63 struct cbuf { 64 unsigned int base; 65 unsigned int len; 66 unsigned int mask; 67 }; 68 69 static void cbuf_add(struct cbuf *cb, int n) 70 { 71 cb->len += n; 72 } 73 74 static int cbuf_data(struct cbuf *cb) 75 { 76 return ((cb->base + cb->len) & cb->mask); 77 } 78 79 static void cbuf_init(struct cbuf *cb, int size) 80 { 81 cb->base = cb->len = 0; 82 cb->mask = size-1; 83 } 84 85 static void cbuf_eat(struct cbuf *cb, int n) 86 { 87 cb->len -= n; 88 cb->base += n; 89 cb->base &= cb->mask; 90 } 91 92 static bool cbuf_empty(struct cbuf *cb) 93 { 94 return cb->len == 0; 95 } 96 97 struct connection { 98 struct socket *sock; /* NULL if not connected */ 99 uint32_t nodeid; /* So we know who we are in the list */ 100 struct mutex sock_mutex; 101 unsigned long flags; 102 #define CF_READ_PENDING 1 103 #define CF_WRITE_PENDING 2 104 #define CF_CONNECT_PENDING 3 105 #define CF_INIT_PENDING 4 106 #define CF_IS_OTHERCON 5 107 struct list_head writequeue; /* List of outgoing writequeue_entries */ 108 spinlock_t writequeue_lock; 109 int (*rx_action) (struct connection *); /* What to do when active */ 110 void (*connect_action) (struct connection *); /* What to do to connect */ 111 struct page *rx_page; 112 struct cbuf cb; 113 int retries; 114 #define MAX_CONNECT_RETRIES 3 115 int sctp_assoc; 116 struct connection *othercon; 117 struct work_struct rwork; /* Receive workqueue */ 118 struct work_struct swork; /* Send workqueue */ 119 }; 120 #define sock2con(x) ((struct connection *)(x)->sk_user_data) 121 122 /* An entry waiting to be sent */ 123 struct writequeue_entry { 124 struct list_head list; 125 struct page *page; 126 int offset; 127 int len; 128 int end; 129 int users; 130 struct connection *con; 131 }; 132 133 static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT]; 134 static int dlm_local_count; 135 136 /* Work queues */ 137 static struct workqueue_struct *recv_workqueue; 138 static struct workqueue_struct *send_workqueue; 139 140 static DEFINE_IDR(connections_idr); 141 static DECLARE_MUTEX(connections_lock); 142 static int max_nodeid; 143 static struct kmem_cache *con_cache; 144 145 static void process_recv_sockets(struct work_struct *work); 146 static void process_send_sockets(struct work_struct *work); 147 148 /* 149 * If 'allocation' is zero then we don't attempt to create a new 150 * connection structure for this node. 151 */ 152 static struct connection *__nodeid2con(int nodeid, gfp_t alloc) 153 { 154 struct connection *con = NULL; 155 int r; 156 int n; 157 158 con = idr_find(&connections_idr, nodeid); 159 if (con || !alloc) 160 return con; 161 162 r = idr_pre_get(&connections_idr, alloc); 163 if (!r) 164 return NULL; 165 166 con = kmem_cache_zalloc(con_cache, alloc); 167 if (!con) 168 return NULL; 169 170 r = idr_get_new_above(&connections_idr, con, nodeid, &n); 171 if (r) { 172 kmem_cache_free(con_cache, con); 173 return NULL; 174 } 175 176 if (n != nodeid) { 177 idr_remove(&connections_idr, n); 178 kmem_cache_free(con_cache, con); 179 return NULL; 180 } 181 182 con->nodeid = nodeid; 183 mutex_init(&con->sock_mutex); 184 INIT_LIST_HEAD(&con->writequeue); 185 spin_lock_init(&con->writequeue_lock); 186 INIT_WORK(&con->swork, process_send_sockets); 187 INIT_WORK(&con->rwork, process_recv_sockets); 188 189 /* Setup action pointers for child sockets */ 190 if (con->nodeid) { 191 struct connection *zerocon = idr_find(&connections_idr, 0); 192 193 con->connect_action = zerocon->connect_action; 194 if (!con->rx_action) 195 con->rx_action = zerocon->rx_action; 196 } 197 198 if (nodeid > max_nodeid) 199 max_nodeid = nodeid; 200 201 return con; 202 } 203 204 static struct connection *nodeid2con(int nodeid, gfp_t allocation) 205 { 206 struct connection *con; 207 208 down(&connections_lock); 209 con = __nodeid2con(nodeid, allocation); 210 up(&connections_lock); 211 212 return con; 213 } 214 215 /* This is a bit drastic, but only called when things go wrong */ 216 static struct connection *assoc2con(int assoc_id) 217 { 218 int i; 219 struct connection *con; 220 221 down(&connections_lock); 222 for (i=0; i<=max_nodeid; i++) { 223 con = __nodeid2con(i, 0); 224 if (con && con->sctp_assoc == assoc_id) { 225 up(&connections_lock); 226 return con; 227 } 228 } 229 up(&connections_lock); 230 return NULL; 231 } 232 233 static int nodeid_to_addr(int nodeid, struct sockaddr *retaddr) 234 { 235 struct sockaddr_storage addr; 236 int error; 237 238 if (!dlm_local_count) 239 return -1; 240 241 error = dlm_nodeid_to_addr(nodeid, &addr); 242 if (error) 243 return error; 244 245 if (dlm_local_addr[0]->ss_family == AF_INET) { 246 struct sockaddr_in *in4 = (struct sockaddr_in *) &addr; 247 struct sockaddr_in *ret4 = (struct sockaddr_in *) retaddr; 248 ret4->sin_addr.s_addr = in4->sin_addr.s_addr; 249 } else { 250 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) &addr; 251 struct sockaddr_in6 *ret6 = (struct sockaddr_in6 *) retaddr; 252 memcpy(&ret6->sin6_addr, &in6->sin6_addr, 253 sizeof(in6->sin6_addr)); 254 } 255 256 return 0; 257 } 258 259 /* Data available on socket or listen socket received a connect */ 260 static void lowcomms_data_ready(struct sock *sk, int count_unused) 261 { 262 struct connection *con = sock2con(sk); 263 if (con && !test_and_set_bit(CF_READ_PENDING, &con->flags)) 264 queue_work(recv_workqueue, &con->rwork); 265 } 266 267 static void lowcomms_write_space(struct sock *sk) 268 { 269 struct connection *con = sock2con(sk); 270 271 if (con && !test_and_set_bit(CF_WRITE_PENDING, &con->flags)) 272 queue_work(send_workqueue, &con->swork); 273 } 274 275 static inline void lowcomms_connect_sock(struct connection *con) 276 { 277 if (!test_and_set_bit(CF_CONNECT_PENDING, &con->flags)) 278 queue_work(send_workqueue, &con->swork); 279 } 280 281 static void lowcomms_state_change(struct sock *sk) 282 { 283 if (sk->sk_state == TCP_ESTABLISHED) 284 lowcomms_write_space(sk); 285 } 286 287 /* Make a socket active */ 288 static int add_sock(struct socket *sock, struct connection *con) 289 { 290 con->sock = sock; 291 292 /* Install a data_ready callback */ 293 con->sock->sk->sk_data_ready = lowcomms_data_ready; 294 con->sock->sk->sk_write_space = lowcomms_write_space; 295 con->sock->sk->sk_state_change = lowcomms_state_change; 296 con->sock->sk->sk_user_data = con; 297 return 0; 298 } 299 300 /* Add the port number to an IPv6 or 4 sockaddr and return the address 301 length */ 302 static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port, 303 int *addr_len) 304 { 305 saddr->ss_family = dlm_local_addr[0]->ss_family; 306 if (saddr->ss_family == AF_INET) { 307 struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr; 308 in4_addr->sin_port = cpu_to_be16(port); 309 *addr_len = sizeof(struct sockaddr_in); 310 memset(&in4_addr->sin_zero, 0, sizeof(in4_addr->sin_zero)); 311 } else { 312 struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr; 313 in6_addr->sin6_port = cpu_to_be16(port); 314 *addr_len = sizeof(struct sockaddr_in6); 315 } 316 memset((char *)saddr + *addr_len, 0, sizeof(struct sockaddr_storage) - *addr_len); 317 } 318 319 /* Close a remote connection and tidy up */ 320 static void close_connection(struct connection *con, bool and_other) 321 { 322 mutex_lock(&con->sock_mutex); 323 324 if (con->sock) { 325 sock_release(con->sock); 326 con->sock = NULL; 327 } 328 if (con->othercon && and_other) { 329 /* Will only re-enter once. */ 330 close_connection(con->othercon, false); 331 } 332 if (con->rx_page) { 333 __free_page(con->rx_page); 334 con->rx_page = NULL; 335 } 336 337 con->retries = 0; 338 mutex_unlock(&con->sock_mutex); 339 } 340 341 /* We only send shutdown messages to nodes that are not part of the cluster */ 342 static void sctp_send_shutdown(sctp_assoc_t associd) 343 { 344 static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 345 struct msghdr outmessage; 346 struct cmsghdr *cmsg; 347 struct sctp_sndrcvinfo *sinfo; 348 int ret; 349 struct connection *con; 350 351 con = nodeid2con(0,0); 352 BUG_ON(con == NULL); 353 354 outmessage.msg_name = NULL; 355 outmessage.msg_namelen = 0; 356 outmessage.msg_control = outcmsg; 357 outmessage.msg_controllen = sizeof(outcmsg); 358 outmessage.msg_flags = MSG_EOR; 359 360 cmsg = CMSG_FIRSTHDR(&outmessage); 361 cmsg->cmsg_level = IPPROTO_SCTP; 362 cmsg->cmsg_type = SCTP_SNDRCV; 363 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo)); 364 outmessage.msg_controllen = cmsg->cmsg_len; 365 sinfo = CMSG_DATA(cmsg); 366 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo)); 367 368 sinfo->sinfo_flags |= MSG_EOF; 369 sinfo->sinfo_assoc_id = associd; 370 371 ret = kernel_sendmsg(con->sock, &outmessage, NULL, 0, 0); 372 373 if (ret != 0) 374 log_print("send EOF to node failed: %d", ret); 375 } 376 377 /* INIT failed but we don't know which node... 378 restart INIT on all pending nodes */ 379 static void sctp_init_failed(void) 380 { 381 int i; 382 struct connection *con; 383 384 down(&connections_lock); 385 for (i=1; i<=max_nodeid; i++) { 386 con = __nodeid2con(i, 0); 387 if (!con) 388 continue; 389 con->sctp_assoc = 0; 390 if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) { 391 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) { 392 queue_work(send_workqueue, &con->swork); 393 } 394 } 395 } 396 up(&connections_lock); 397 } 398 399 /* Something happened to an association */ 400 static void process_sctp_notification(struct connection *con, 401 struct msghdr *msg, char *buf) 402 { 403 union sctp_notification *sn = (union sctp_notification *)buf; 404 405 if (sn->sn_header.sn_type == SCTP_ASSOC_CHANGE) { 406 switch (sn->sn_assoc_change.sac_state) { 407 408 case SCTP_COMM_UP: 409 case SCTP_RESTART: 410 { 411 /* Check that the new node is in the lockspace */ 412 struct sctp_prim prim; 413 int nodeid; 414 int prim_len, ret; 415 int addr_len; 416 struct connection *new_con; 417 struct file *file; 418 sctp_peeloff_arg_t parg; 419 int parglen = sizeof(parg); 420 421 /* 422 * We get this before any data for an association. 423 * We verify that the node is in the cluster and 424 * then peel off a socket for it. 425 */ 426 if ((int)sn->sn_assoc_change.sac_assoc_id <= 0) { 427 log_print("COMM_UP for invalid assoc ID %d", 428 (int)sn->sn_assoc_change.sac_assoc_id); 429 sctp_init_failed(); 430 return; 431 } 432 memset(&prim, 0, sizeof(struct sctp_prim)); 433 prim_len = sizeof(struct sctp_prim); 434 prim.ssp_assoc_id = sn->sn_assoc_change.sac_assoc_id; 435 436 ret = kernel_getsockopt(con->sock, 437 IPPROTO_SCTP, 438 SCTP_PRIMARY_ADDR, 439 (char*)&prim, 440 &prim_len); 441 if (ret < 0) { 442 log_print("getsockopt/sctp_primary_addr on " 443 "new assoc %d failed : %d", 444 (int)sn->sn_assoc_change.sac_assoc_id, 445 ret); 446 447 /* Retry INIT later */ 448 new_con = assoc2con(sn->sn_assoc_change.sac_assoc_id); 449 if (new_con) 450 clear_bit(CF_CONNECT_PENDING, &con->flags); 451 return; 452 } 453 make_sockaddr(&prim.ssp_addr, 0, &addr_len); 454 if (dlm_addr_to_nodeid(&prim.ssp_addr, &nodeid)) { 455 int i; 456 unsigned char *b=(unsigned char *)&prim.ssp_addr; 457 log_print("reject connect from unknown addr"); 458 for (i=0; i<sizeof(struct sockaddr_storage);i++) 459 printk("%02x ", b[i]); 460 printk("\n"); 461 sctp_send_shutdown(prim.ssp_assoc_id); 462 return; 463 } 464 465 new_con = nodeid2con(nodeid, GFP_KERNEL); 466 if (!new_con) 467 return; 468 469 /* Peel off a new sock */ 470 parg.associd = sn->sn_assoc_change.sac_assoc_id; 471 ret = kernel_getsockopt(con->sock, IPPROTO_SCTP, 472 SCTP_SOCKOPT_PEELOFF, 473 (void *)&parg, &parglen); 474 if (ret) { 475 log_print("Can't peel off a socket for " 476 "connection %d to node %d: err=%d\n", 477 parg.associd, nodeid, ret); 478 } 479 file = fget(parg.sd); 480 new_con->sock = SOCKET_I(file->f_dentry->d_inode); 481 add_sock(new_con->sock, new_con); 482 fput(file); 483 put_unused_fd(parg.sd); 484 485 log_print("got new/restarted association %d nodeid %d", 486 (int)sn->sn_assoc_change.sac_assoc_id, nodeid); 487 488 /* Send any pending writes */ 489 clear_bit(CF_CONNECT_PENDING, &new_con->flags); 490 clear_bit(CF_INIT_PENDING, &con->flags); 491 if (!test_and_set_bit(CF_WRITE_PENDING, &new_con->flags)) { 492 queue_work(send_workqueue, &new_con->swork); 493 } 494 if (!test_and_set_bit(CF_READ_PENDING, &new_con->flags)) 495 queue_work(recv_workqueue, &new_con->rwork); 496 } 497 break; 498 499 case SCTP_COMM_LOST: 500 case SCTP_SHUTDOWN_COMP: 501 { 502 con = assoc2con(sn->sn_assoc_change.sac_assoc_id); 503 if (con) { 504 con->sctp_assoc = 0; 505 } 506 } 507 break; 508 509 /* We don't know which INIT failed, so clear the PENDING flags 510 * on them all. if assoc_id is zero then it will then try 511 * again */ 512 513 case SCTP_CANT_STR_ASSOC: 514 { 515 log_print("Can't start SCTP association - retrying"); 516 sctp_init_failed(); 517 } 518 break; 519 520 default: 521 log_print("unexpected SCTP assoc change id=%d state=%d", 522 (int)sn->sn_assoc_change.sac_assoc_id, 523 sn->sn_assoc_change.sac_state); 524 } 525 } 526 } 527 528 /* Data received from remote end */ 529 static int receive_from_sock(struct connection *con) 530 { 531 int ret = 0; 532 struct msghdr msg = {}; 533 struct kvec iov[2]; 534 unsigned len; 535 int r; 536 int call_again_soon = 0; 537 int nvec; 538 char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 539 540 mutex_lock(&con->sock_mutex); 541 542 if (con->sock == NULL) { 543 ret = -EAGAIN; 544 goto out_close; 545 } 546 547 if (con->rx_page == NULL) { 548 /* 549 * This doesn't need to be atomic, but I think it should 550 * improve performance if it is. 551 */ 552 con->rx_page = alloc_page(GFP_ATOMIC); 553 if (con->rx_page == NULL) 554 goto out_resched; 555 cbuf_init(&con->cb, PAGE_CACHE_SIZE); 556 } 557 558 /* Only SCTP needs these really */ 559 memset(&incmsg, 0, sizeof(incmsg)); 560 msg.msg_control = incmsg; 561 msg.msg_controllen = sizeof(incmsg); 562 563 /* 564 * iov[0] is the bit of the circular buffer between the current end 565 * point (cb.base + cb.len) and the end of the buffer. 566 */ 567 iov[0].iov_len = con->cb.base - cbuf_data(&con->cb); 568 iov[0].iov_base = page_address(con->rx_page) + cbuf_data(&con->cb); 569 iov[1].iov_len = 0; 570 nvec = 1; 571 572 /* 573 * iov[1] is the bit of the circular buffer between the start of the 574 * buffer and the start of the currently used section (cb.base) 575 */ 576 if (cbuf_data(&con->cb) >= con->cb.base) { 577 iov[0].iov_len = PAGE_CACHE_SIZE - cbuf_data(&con->cb); 578 iov[1].iov_len = con->cb.base; 579 iov[1].iov_base = page_address(con->rx_page); 580 nvec = 2; 581 } 582 len = iov[0].iov_len + iov[1].iov_len; 583 584 r = ret = kernel_recvmsg(con->sock, &msg, iov, nvec, len, 585 MSG_DONTWAIT | MSG_NOSIGNAL); 586 if (ret <= 0) 587 goto out_close; 588 589 /* Process SCTP notifications */ 590 if (msg.msg_flags & MSG_NOTIFICATION) { 591 msg.msg_control = incmsg; 592 msg.msg_controllen = sizeof(incmsg); 593 594 process_sctp_notification(con, &msg, 595 page_address(con->rx_page) + con->cb.base); 596 mutex_unlock(&con->sock_mutex); 597 return 0; 598 } 599 BUG_ON(con->nodeid == 0); 600 601 if (ret == len) 602 call_again_soon = 1; 603 cbuf_add(&con->cb, ret); 604 ret = dlm_process_incoming_buffer(con->nodeid, 605 page_address(con->rx_page), 606 con->cb.base, con->cb.len, 607 PAGE_CACHE_SIZE); 608 if (ret == -EBADMSG) { 609 log_print("lowcomms: addr=%p, base=%u, len=%u, " 610 "iov_len=%u, iov_base[0]=%p, read=%d", 611 page_address(con->rx_page), con->cb.base, con->cb.len, 612 len, iov[0].iov_base, r); 613 } 614 if (ret < 0) 615 goto out_close; 616 cbuf_eat(&con->cb, ret); 617 618 if (cbuf_empty(&con->cb) && !call_again_soon) { 619 __free_page(con->rx_page); 620 con->rx_page = NULL; 621 } 622 623 if (call_again_soon) 624 goto out_resched; 625 mutex_unlock(&con->sock_mutex); 626 return 0; 627 628 out_resched: 629 if (!test_and_set_bit(CF_READ_PENDING, &con->flags)) 630 queue_work(recv_workqueue, &con->rwork); 631 mutex_unlock(&con->sock_mutex); 632 return -EAGAIN; 633 634 out_close: 635 mutex_unlock(&con->sock_mutex); 636 if (ret != -EAGAIN) { 637 close_connection(con, false); 638 /* Reconnect when there is something to send */ 639 } 640 /* Don't return success if we really got EOF */ 641 if (ret == 0) 642 ret = -EAGAIN; 643 644 return ret; 645 } 646 647 /* Listening socket is busy, accept a connection */ 648 static int tcp_accept_from_sock(struct connection *con) 649 { 650 int result; 651 struct sockaddr_storage peeraddr; 652 struct socket *newsock; 653 int len; 654 int nodeid; 655 struct connection *newcon; 656 struct connection *addcon; 657 658 memset(&peeraddr, 0, sizeof(peeraddr)); 659 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 660 IPPROTO_TCP, &newsock); 661 if (result < 0) 662 return -ENOMEM; 663 664 mutex_lock_nested(&con->sock_mutex, 0); 665 666 result = -ENOTCONN; 667 if (con->sock == NULL) 668 goto accept_err; 669 670 newsock->type = con->sock->type; 671 newsock->ops = con->sock->ops; 672 673 result = con->sock->ops->accept(con->sock, newsock, O_NONBLOCK); 674 if (result < 0) 675 goto accept_err; 676 677 /* Get the connected socket's peer */ 678 memset(&peeraddr, 0, sizeof(peeraddr)); 679 if (newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr, 680 &len, 2)) { 681 result = -ECONNABORTED; 682 goto accept_err; 683 } 684 685 /* Get the new node's NODEID */ 686 make_sockaddr(&peeraddr, 0, &len); 687 if (dlm_addr_to_nodeid(&peeraddr, &nodeid)) { 688 log_print("connect from non cluster node"); 689 sock_release(newsock); 690 mutex_unlock(&con->sock_mutex); 691 return -1; 692 } 693 694 log_print("got connection from %d", nodeid); 695 696 /* Check to see if we already have a connection to this node. This 697 * could happen if the two nodes initiate a connection at roughly 698 * the same time and the connections cross on the wire. 699 * In this case we store the incoming one in "othercon" 700 */ 701 newcon = nodeid2con(nodeid, GFP_KERNEL); 702 if (!newcon) { 703 result = -ENOMEM; 704 goto accept_err; 705 } 706 mutex_lock_nested(&newcon->sock_mutex, 1); 707 if (newcon->sock) { 708 struct connection *othercon = newcon->othercon; 709 710 if (!othercon) { 711 othercon = kmem_cache_zalloc(con_cache, GFP_KERNEL); 712 if (!othercon) { 713 log_print("failed to allocate incoming socket"); 714 mutex_unlock(&newcon->sock_mutex); 715 result = -ENOMEM; 716 goto accept_err; 717 } 718 othercon->nodeid = nodeid; 719 othercon->rx_action = receive_from_sock; 720 mutex_init(&othercon->sock_mutex); 721 INIT_WORK(&othercon->swork, process_send_sockets); 722 INIT_WORK(&othercon->rwork, process_recv_sockets); 723 set_bit(CF_IS_OTHERCON, &othercon->flags); 724 } 725 if (!othercon->sock) { 726 newcon->othercon = othercon; 727 othercon->sock = newsock; 728 newsock->sk->sk_user_data = othercon; 729 add_sock(newsock, othercon); 730 addcon = othercon; 731 } 732 else { 733 printk("Extra connection from node %d attempted\n", nodeid); 734 result = -EAGAIN; 735 mutex_unlock(&newcon->sock_mutex); 736 goto accept_err; 737 } 738 } 739 else { 740 newsock->sk->sk_user_data = newcon; 741 newcon->rx_action = receive_from_sock; 742 add_sock(newsock, newcon); 743 addcon = newcon; 744 } 745 746 mutex_unlock(&newcon->sock_mutex); 747 748 /* 749 * Add it to the active queue in case we got data 750 * beween processing the accept adding the socket 751 * to the read_sockets list 752 */ 753 if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags)) 754 queue_work(recv_workqueue, &addcon->rwork); 755 mutex_unlock(&con->sock_mutex); 756 757 return 0; 758 759 accept_err: 760 mutex_unlock(&con->sock_mutex); 761 sock_release(newsock); 762 763 if (result != -EAGAIN) 764 log_print("error accepting connection from node: %d", result); 765 return result; 766 } 767 768 static void free_entry(struct writequeue_entry *e) 769 { 770 __free_page(e->page); 771 kfree(e); 772 } 773 774 /* Initiate an SCTP association. 775 This is a special case of send_to_sock() in that we don't yet have a 776 peeled-off socket for this association, so we use the listening socket 777 and add the primary IP address of the remote node. 778 */ 779 static void sctp_init_assoc(struct connection *con) 780 { 781 struct sockaddr_storage rem_addr; 782 char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 783 struct msghdr outmessage; 784 struct cmsghdr *cmsg; 785 struct sctp_sndrcvinfo *sinfo; 786 struct connection *base_con; 787 struct writequeue_entry *e; 788 int len, offset; 789 int ret; 790 int addrlen; 791 struct kvec iov[1]; 792 793 if (test_and_set_bit(CF_INIT_PENDING, &con->flags)) 794 return; 795 796 if (con->retries++ > MAX_CONNECT_RETRIES) 797 return; 798 799 log_print("Initiating association with node %d", con->nodeid); 800 801 if (nodeid_to_addr(con->nodeid, (struct sockaddr *)&rem_addr)) { 802 log_print("no address for nodeid %d", con->nodeid); 803 return; 804 } 805 base_con = nodeid2con(0, 0); 806 BUG_ON(base_con == NULL); 807 808 make_sockaddr(&rem_addr, dlm_config.ci_tcp_port, &addrlen); 809 810 outmessage.msg_name = &rem_addr; 811 outmessage.msg_namelen = addrlen; 812 outmessage.msg_control = outcmsg; 813 outmessage.msg_controllen = sizeof(outcmsg); 814 outmessage.msg_flags = MSG_EOR; 815 816 spin_lock(&con->writequeue_lock); 817 e = list_entry(con->writequeue.next, struct writequeue_entry, 818 list); 819 820 BUG_ON((struct list_head *) e == &con->writequeue); 821 822 len = e->len; 823 offset = e->offset; 824 spin_unlock(&con->writequeue_lock); 825 kmap(e->page); 826 827 /* Send the first block off the write queue */ 828 iov[0].iov_base = page_address(e->page)+offset; 829 iov[0].iov_len = len; 830 831 cmsg = CMSG_FIRSTHDR(&outmessage); 832 cmsg->cmsg_level = IPPROTO_SCTP; 833 cmsg->cmsg_type = SCTP_SNDRCV; 834 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo)); 835 sinfo = CMSG_DATA(cmsg); 836 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo)); 837 sinfo->sinfo_ppid = cpu_to_le32(dlm_our_nodeid()); 838 outmessage.msg_controllen = cmsg->cmsg_len; 839 840 ret = kernel_sendmsg(base_con->sock, &outmessage, iov, 1, len); 841 if (ret < 0) { 842 log_print("Send first packet to node %d failed: %d", 843 con->nodeid, ret); 844 845 /* Try again later */ 846 clear_bit(CF_CONNECT_PENDING, &con->flags); 847 clear_bit(CF_INIT_PENDING, &con->flags); 848 } 849 else { 850 spin_lock(&con->writequeue_lock); 851 e->offset += ret; 852 e->len -= ret; 853 854 if (e->len == 0 && e->users == 0) { 855 list_del(&e->list); 856 kunmap(e->page); 857 free_entry(e); 858 } 859 spin_unlock(&con->writequeue_lock); 860 } 861 } 862 863 /* Connect a new socket to its peer */ 864 static void tcp_connect_to_sock(struct connection *con) 865 { 866 int result = -EHOSTUNREACH; 867 struct sockaddr_storage saddr, src_addr; 868 int addr_len; 869 struct socket *sock; 870 871 if (con->nodeid == 0) { 872 log_print("attempt to connect sock 0 foiled"); 873 return; 874 } 875 876 mutex_lock(&con->sock_mutex); 877 if (con->retries++ > MAX_CONNECT_RETRIES) 878 goto out; 879 880 /* Some odd races can cause double-connects, ignore them */ 881 if (con->sock) { 882 result = 0; 883 goto out; 884 } 885 886 /* Create a socket to communicate with */ 887 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 888 IPPROTO_TCP, &sock); 889 if (result < 0) 890 goto out_err; 891 892 memset(&saddr, 0, sizeof(saddr)); 893 if (dlm_nodeid_to_addr(con->nodeid, &saddr)) 894 goto out_err; 895 896 sock->sk->sk_user_data = con; 897 con->rx_action = receive_from_sock; 898 con->connect_action = tcp_connect_to_sock; 899 add_sock(sock, con); 900 901 /* Bind to our cluster-known address connecting to avoid 902 routing problems */ 903 memcpy(&src_addr, dlm_local_addr[0], sizeof(src_addr)); 904 make_sockaddr(&src_addr, 0, &addr_len); 905 result = sock->ops->bind(sock, (struct sockaddr *) &src_addr, 906 addr_len); 907 if (result < 0) { 908 log_print("could not bind for connect: %d", result); 909 /* This *may* not indicate a critical error */ 910 } 911 912 make_sockaddr(&saddr, dlm_config.ci_tcp_port, &addr_len); 913 914 log_print("connecting to %d", con->nodeid); 915 result = 916 sock->ops->connect(sock, (struct sockaddr *)&saddr, addr_len, 917 O_NONBLOCK); 918 if (result == -EINPROGRESS) 919 result = 0; 920 if (result == 0) 921 goto out; 922 923 out_err: 924 if (con->sock) { 925 sock_release(con->sock); 926 con->sock = NULL; 927 } 928 /* 929 * Some errors are fatal and this list might need adjusting. For other 930 * errors we try again until the max number of retries is reached. 931 */ 932 if (result != -EHOSTUNREACH && result != -ENETUNREACH && 933 result != -ENETDOWN && result != EINVAL 934 && result != -EPROTONOSUPPORT) { 935 lowcomms_connect_sock(con); 936 result = 0; 937 } 938 out: 939 mutex_unlock(&con->sock_mutex); 940 return; 941 } 942 943 static struct socket *tcp_create_listen_sock(struct connection *con, 944 struct sockaddr_storage *saddr) 945 { 946 struct socket *sock = NULL; 947 int result = 0; 948 int one = 1; 949 int addr_len; 950 951 if (dlm_local_addr[0]->ss_family == AF_INET) 952 addr_len = sizeof(struct sockaddr_in); 953 else 954 addr_len = sizeof(struct sockaddr_in6); 955 956 /* Create a socket to communicate with */ 957 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 958 IPPROTO_TCP, &sock); 959 if (result < 0) { 960 log_print("Can't create listening comms socket"); 961 goto create_out; 962 } 963 964 result = kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, 965 (char *)&one, sizeof(one)); 966 967 if (result < 0) { 968 log_print("Failed to set SO_REUSEADDR on socket: %d", result); 969 } 970 sock->sk->sk_user_data = con; 971 con->rx_action = tcp_accept_from_sock; 972 con->connect_action = tcp_connect_to_sock; 973 con->sock = sock; 974 975 /* Bind to our port */ 976 make_sockaddr(saddr, dlm_config.ci_tcp_port, &addr_len); 977 result = sock->ops->bind(sock, (struct sockaddr *) saddr, addr_len); 978 if (result < 0) { 979 log_print("Can't bind to port %d", dlm_config.ci_tcp_port); 980 sock_release(sock); 981 sock = NULL; 982 con->sock = NULL; 983 goto create_out; 984 } 985 result = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, 986 (char *)&one, sizeof(one)); 987 if (result < 0) { 988 log_print("Set keepalive failed: %d", result); 989 } 990 991 result = sock->ops->listen(sock, 5); 992 if (result < 0) { 993 log_print("Can't listen on port %d", dlm_config.ci_tcp_port); 994 sock_release(sock); 995 sock = NULL; 996 goto create_out; 997 } 998 999 create_out: 1000 return sock; 1001 } 1002 1003 /* Get local addresses */ 1004 static void init_local(void) 1005 { 1006 struct sockaddr_storage sas, *addr; 1007 int i; 1008 1009 dlm_local_count = 0; 1010 for (i = 0; i < DLM_MAX_ADDR_COUNT - 1; i++) { 1011 if (dlm_our_addr(&sas, i)) 1012 break; 1013 1014 addr = kmalloc(sizeof(*addr), GFP_KERNEL); 1015 if (!addr) 1016 break; 1017 memcpy(addr, &sas, sizeof(*addr)); 1018 dlm_local_addr[dlm_local_count++] = addr; 1019 } 1020 } 1021 1022 /* Bind to an IP address. SCTP allows multiple address so it can do 1023 multi-homing */ 1024 static int add_sctp_bind_addr(struct connection *sctp_con, 1025 struct sockaddr_storage *addr, 1026 int addr_len, int num) 1027 { 1028 int result = 0; 1029 1030 if (num == 1) 1031 result = kernel_bind(sctp_con->sock, 1032 (struct sockaddr *) addr, 1033 addr_len); 1034 else 1035 result = kernel_setsockopt(sctp_con->sock, SOL_SCTP, 1036 SCTP_SOCKOPT_BINDX_ADD, 1037 (char *)addr, addr_len); 1038 1039 if (result < 0) 1040 log_print("Can't bind to port %d addr number %d", 1041 dlm_config.ci_tcp_port, num); 1042 1043 return result; 1044 } 1045 1046 /* Initialise SCTP socket and bind to all interfaces */ 1047 static int sctp_listen_for_all(void) 1048 { 1049 struct socket *sock = NULL; 1050 struct sockaddr_storage localaddr; 1051 struct sctp_event_subscribe subscribe; 1052 int result = -EINVAL, num = 1, i, addr_len; 1053 struct connection *con = nodeid2con(0, GFP_KERNEL); 1054 int bufsize = NEEDED_RMEM; 1055 1056 if (!con) 1057 return -ENOMEM; 1058 1059 log_print("Using SCTP for communications"); 1060 1061 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_SEQPACKET, 1062 IPPROTO_SCTP, &sock); 1063 if (result < 0) { 1064 log_print("Can't create comms socket, check SCTP is loaded"); 1065 goto out; 1066 } 1067 1068 /* Listen for events */ 1069 memset(&subscribe, 0, sizeof(subscribe)); 1070 subscribe.sctp_data_io_event = 1; 1071 subscribe.sctp_association_event = 1; 1072 subscribe.sctp_send_failure_event = 1; 1073 subscribe.sctp_shutdown_event = 1; 1074 subscribe.sctp_partial_delivery_event = 1; 1075 1076 result = kernel_setsockopt(sock, SOL_SOCKET, SO_RCVBUFFORCE, 1077 (char *)&bufsize, sizeof(bufsize)); 1078 if (result) 1079 log_print("Error increasing buffer space on socket %d", result); 1080 1081 result = kernel_setsockopt(sock, SOL_SCTP, SCTP_EVENTS, 1082 (char *)&subscribe, sizeof(subscribe)); 1083 if (result < 0) { 1084 log_print("Failed to set SCTP_EVENTS on socket: result=%d", 1085 result); 1086 goto create_delsock; 1087 } 1088 1089 /* Init con struct */ 1090 sock->sk->sk_user_data = con; 1091 con->sock = sock; 1092 con->sock->sk->sk_data_ready = lowcomms_data_ready; 1093 con->rx_action = receive_from_sock; 1094 con->connect_action = sctp_init_assoc; 1095 1096 /* Bind to all interfaces. */ 1097 for (i = 0; i < dlm_local_count; i++) { 1098 memcpy(&localaddr, dlm_local_addr[i], sizeof(localaddr)); 1099 make_sockaddr(&localaddr, dlm_config.ci_tcp_port, &addr_len); 1100 1101 result = add_sctp_bind_addr(con, &localaddr, addr_len, num); 1102 if (result) 1103 goto create_delsock; 1104 ++num; 1105 } 1106 1107 result = sock->ops->listen(sock, 5); 1108 if (result < 0) { 1109 log_print("Can't set socket listening"); 1110 goto create_delsock; 1111 } 1112 1113 return 0; 1114 1115 create_delsock: 1116 sock_release(sock); 1117 con->sock = NULL; 1118 out: 1119 return result; 1120 } 1121 1122 static int tcp_listen_for_all(void) 1123 { 1124 struct socket *sock = NULL; 1125 struct connection *con = nodeid2con(0, GFP_KERNEL); 1126 int result = -EINVAL; 1127 1128 if (!con) 1129 return -ENOMEM; 1130 1131 /* We don't support multi-homed hosts */ 1132 if (dlm_local_addr[1] != NULL) { 1133 log_print("TCP protocol can't handle multi-homed hosts, " 1134 "try SCTP"); 1135 return -EINVAL; 1136 } 1137 1138 log_print("Using TCP for communications"); 1139 1140 sock = tcp_create_listen_sock(con, dlm_local_addr[0]); 1141 if (sock) { 1142 add_sock(sock, con); 1143 result = 0; 1144 } 1145 else { 1146 result = -EADDRINUSE; 1147 } 1148 1149 return result; 1150 } 1151 1152 1153 1154 static struct writequeue_entry *new_writequeue_entry(struct connection *con, 1155 gfp_t allocation) 1156 { 1157 struct writequeue_entry *entry; 1158 1159 entry = kmalloc(sizeof(struct writequeue_entry), allocation); 1160 if (!entry) 1161 return NULL; 1162 1163 entry->page = alloc_page(allocation); 1164 if (!entry->page) { 1165 kfree(entry); 1166 return NULL; 1167 } 1168 1169 entry->offset = 0; 1170 entry->len = 0; 1171 entry->end = 0; 1172 entry->users = 0; 1173 entry->con = con; 1174 1175 return entry; 1176 } 1177 1178 void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc) 1179 { 1180 struct connection *con; 1181 struct writequeue_entry *e; 1182 int offset = 0; 1183 int users = 0; 1184 1185 con = nodeid2con(nodeid, allocation); 1186 if (!con) 1187 return NULL; 1188 1189 spin_lock(&con->writequeue_lock); 1190 e = list_entry(con->writequeue.prev, struct writequeue_entry, list); 1191 if ((&e->list == &con->writequeue) || 1192 (PAGE_CACHE_SIZE - e->end < len)) { 1193 e = NULL; 1194 } else { 1195 offset = e->end; 1196 e->end += len; 1197 users = e->users++; 1198 } 1199 spin_unlock(&con->writequeue_lock); 1200 1201 if (e) { 1202 got_one: 1203 if (users == 0) 1204 kmap(e->page); 1205 *ppc = page_address(e->page) + offset; 1206 return e; 1207 } 1208 1209 e = new_writequeue_entry(con, allocation); 1210 if (e) { 1211 spin_lock(&con->writequeue_lock); 1212 offset = e->end; 1213 e->end += len; 1214 users = e->users++; 1215 list_add_tail(&e->list, &con->writequeue); 1216 spin_unlock(&con->writequeue_lock); 1217 goto got_one; 1218 } 1219 return NULL; 1220 } 1221 1222 void dlm_lowcomms_commit_buffer(void *mh) 1223 { 1224 struct writequeue_entry *e = (struct writequeue_entry *)mh; 1225 struct connection *con = e->con; 1226 int users; 1227 1228 spin_lock(&con->writequeue_lock); 1229 users = --e->users; 1230 if (users) 1231 goto out; 1232 e->len = e->end - e->offset; 1233 kunmap(e->page); 1234 spin_unlock(&con->writequeue_lock); 1235 1236 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) { 1237 queue_work(send_workqueue, &con->swork); 1238 } 1239 return; 1240 1241 out: 1242 spin_unlock(&con->writequeue_lock); 1243 return; 1244 } 1245 1246 /* Send a message */ 1247 static void send_to_sock(struct connection *con) 1248 { 1249 int ret = 0; 1250 ssize_t(*sendpage) (struct socket *, struct page *, int, size_t, int); 1251 const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL; 1252 struct writequeue_entry *e; 1253 int len, offset; 1254 1255 mutex_lock(&con->sock_mutex); 1256 if (con->sock == NULL) 1257 goto out_connect; 1258 1259 sendpage = con->sock->ops->sendpage; 1260 1261 spin_lock(&con->writequeue_lock); 1262 for (;;) { 1263 e = list_entry(con->writequeue.next, struct writequeue_entry, 1264 list); 1265 if ((struct list_head *) e == &con->writequeue) 1266 break; 1267 1268 len = e->len; 1269 offset = e->offset; 1270 BUG_ON(len == 0 && e->users == 0); 1271 spin_unlock(&con->writequeue_lock); 1272 kmap(e->page); 1273 1274 ret = 0; 1275 if (len) { 1276 ret = sendpage(con->sock, e->page, offset, len, 1277 msg_flags); 1278 if (ret == -EAGAIN || ret == 0) { 1279 cond_resched(); 1280 goto out; 1281 } 1282 if (ret <= 0) 1283 goto send_error; 1284 } 1285 /* Don't starve people filling buffers */ 1286 cond_resched(); 1287 1288 spin_lock(&con->writequeue_lock); 1289 e->offset += ret; 1290 e->len -= ret; 1291 1292 if (e->len == 0 && e->users == 0) { 1293 list_del(&e->list); 1294 kunmap(e->page); 1295 free_entry(e); 1296 continue; 1297 } 1298 } 1299 spin_unlock(&con->writequeue_lock); 1300 out: 1301 mutex_unlock(&con->sock_mutex); 1302 return; 1303 1304 send_error: 1305 mutex_unlock(&con->sock_mutex); 1306 close_connection(con, false); 1307 lowcomms_connect_sock(con); 1308 return; 1309 1310 out_connect: 1311 mutex_unlock(&con->sock_mutex); 1312 if (!test_bit(CF_INIT_PENDING, &con->flags)) 1313 lowcomms_connect_sock(con); 1314 return; 1315 } 1316 1317 static void clean_one_writequeue(struct connection *con) 1318 { 1319 struct list_head *list; 1320 struct list_head *temp; 1321 1322 spin_lock(&con->writequeue_lock); 1323 list_for_each_safe(list, temp, &con->writequeue) { 1324 struct writequeue_entry *e = 1325 list_entry(list, struct writequeue_entry, list); 1326 list_del(&e->list); 1327 free_entry(e); 1328 } 1329 spin_unlock(&con->writequeue_lock); 1330 } 1331 1332 /* Called from recovery when it knows that a node has 1333 left the cluster */ 1334 int dlm_lowcomms_close(int nodeid) 1335 { 1336 struct connection *con; 1337 1338 log_print("closing connection to node %d", nodeid); 1339 con = nodeid2con(nodeid, 0); 1340 if (con) { 1341 clean_one_writequeue(con); 1342 close_connection(con, true); 1343 } 1344 return 0; 1345 } 1346 1347 /* Receive workqueue function */ 1348 static void process_recv_sockets(struct work_struct *work) 1349 { 1350 struct connection *con = container_of(work, struct connection, rwork); 1351 int err; 1352 1353 clear_bit(CF_READ_PENDING, &con->flags); 1354 do { 1355 err = con->rx_action(con); 1356 } while (!err); 1357 } 1358 1359 /* Send workqueue function */ 1360 static void process_send_sockets(struct work_struct *work) 1361 { 1362 struct connection *con = container_of(work, struct connection, swork); 1363 1364 if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) { 1365 con->connect_action(con); 1366 } 1367 clear_bit(CF_WRITE_PENDING, &con->flags); 1368 send_to_sock(con); 1369 } 1370 1371 1372 /* Discard all entries on the write queues */ 1373 static void clean_writequeues(void) 1374 { 1375 int nodeid; 1376 1377 for (nodeid = 1; nodeid <= max_nodeid; nodeid++) { 1378 struct connection *con = __nodeid2con(nodeid, 0); 1379 1380 if (con) 1381 clean_one_writequeue(con); 1382 } 1383 } 1384 1385 static void work_stop(void) 1386 { 1387 destroy_workqueue(recv_workqueue); 1388 destroy_workqueue(send_workqueue); 1389 } 1390 1391 static int work_start(void) 1392 { 1393 int error; 1394 recv_workqueue = create_workqueue("dlm_recv"); 1395 error = IS_ERR(recv_workqueue); 1396 if (error) { 1397 log_print("can't start dlm_recv %d", error); 1398 return error; 1399 } 1400 1401 send_workqueue = create_singlethread_workqueue("dlm_send"); 1402 error = IS_ERR(send_workqueue); 1403 if (error) { 1404 log_print("can't start dlm_send %d", error); 1405 destroy_workqueue(recv_workqueue); 1406 return error; 1407 } 1408 1409 return 0; 1410 } 1411 1412 void dlm_lowcomms_stop(void) 1413 { 1414 int i; 1415 struct connection *con; 1416 1417 /* Set all the flags to prevent any 1418 socket activity. 1419 */ 1420 down(&connections_lock); 1421 for (i = 0; i <= max_nodeid; i++) { 1422 con = __nodeid2con(i, 0); 1423 if (con) { 1424 con->flags |= 0x0F; 1425 if (con->sock) 1426 con->sock->sk->sk_user_data = NULL; 1427 } 1428 } 1429 up(&connections_lock); 1430 1431 work_stop(); 1432 1433 down(&connections_lock); 1434 clean_writequeues(); 1435 1436 for (i = 0; i <= max_nodeid; i++) { 1437 con = __nodeid2con(i, 0); 1438 if (con) { 1439 close_connection(con, true); 1440 if (con->othercon) 1441 kmem_cache_free(con_cache, con->othercon); 1442 kmem_cache_free(con_cache, con); 1443 } 1444 } 1445 max_nodeid = 0; 1446 up(&connections_lock); 1447 kmem_cache_destroy(con_cache); 1448 idr_init(&connections_idr); 1449 } 1450 1451 int dlm_lowcomms_start(void) 1452 { 1453 int error = -EINVAL; 1454 struct connection *con; 1455 1456 init_local(); 1457 if (!dlm_local_count) { 1458 error = -ENOTCONN; 1459 log_print("no local IP address has been set"); 1460 goto out; 1461 } 1462 1463 error = -ENOMEM; 1464 con_cache = kmem_cache_create("dlm_conn", sizeof(struct connection), 1465 __alignof__(struct connection), 0, 1466 NULL); 1467 if (!con_cache) 1468 goto out; 1469 1470 /* Start listening */ 1471 if (dlm_config.ci_protocol == 0) 1472 error = tcp_listen_for_all(); 1473 else 1474 error = sctp_listen_for_all(); 1475 if (error) 1476 goto fail_unlisten; 1477 1478 error = work_start(); 1479 if (error) 1480 goto fail_unlisten; 1481 1482 return 0; 1483 1484 fail_unlisten: 1485 con = nodeid2con(0,0); 1486 if (con) { 1487 close_connection(con, false); 1488 kmem_cache_free(con_cache, con); 1489 } 1490 kmem_cache_destroy(con_cache); 1491 1492 out: 1493 return error; 1494 } 1495