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/mutex.h> 54 #include <linux/sctp.h> 55 #include <net/sctp/user.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 64 struct cbuf { 65 unsigned int base; 66 unsigned int len; 67 unsigned int mask; 68 }; 69 70 static void cbuf_add(struct cbuf *cb, int n) 71 { 72 cb->len += n; 73 } 74 75 static int cbuf_data(struct cbuf *cb) 76 { 77 return ((cb->base + cb->len) & cb->mask); 78 } 79 80 static void cbuf_init(struct cbuf *cb, int size) 81 { 82 cb->base = cb->len = 0; 83 cb->mask = size-1; 84 } 85 86 static void cbuf_eat(struct cbuf *cb, int n) 87 { 88 cb->len -= n; 89 cb->base += n; 90 cb->base &= cb->mask; 91 } 92 93 static bool cbuf_empty(struct cbuf *cb) 94 { 95 return cb->len == 0; 96 } 97 98 struct connection { 99 struct socket *sock; /* NULL if not connected */ 100 uint32_t nodeid; /* So we know who we are in the list */ 101 struct mutex sock_mutex; 102 unsigned long flags; 103 #define CF_READ_PENDING 1 104 #define CF_WRITE_PENDING 2 105 #define CF_CONNECT_PENDING 3 106 #define CF_INIT_PENDING 4 107 #define CF_IS_OTHERCON 5 108 struct list_head writequeue; /* List of outgoing writequeue_entries */ 109 spinlock_t writequeue_lock; 110 int (*rx_action) (struct connection *); /* What to do when active */ 111 void (*connect_action) (struct connection *); /* What to do to connect */ 112 struct page *rx_page; 113 struct cbuf cb; 114 int retries; 115 #define MAX_CONNECT_RETRIES 3 116 int sctp_assoc; 117 struct connection *othercon; 118 struct work_struct rwork; /* Receive workqueue */ 119 struct work_struct swork; /* Send workqueue */ 120 }; 121 #define sock2con(x) ((struct connection *)(x)->sk_user_data) 122 123 /* An entry waiting to be sent */ 124 struct writequeue_entry { 125 struct list_head list; 126 struct page *page; 127 int offset; 128 int len; 129 int end; 130 int users; 131 struct connection *con; 132 }; 133 134 static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT]; 135 static int dlm_local_count; 136 137 /* Work queues */ 138 static struct workqueue_struct *recv_workqueue; 139 static struct workqueue_struct *send_workqueue; 140 141 static DEFINE_IDR(connections_idr); 142 static DEFINE_MUTEX(connections_lock); 143 static int max_nodeid; 144 static struct kmem_cache *con_cache; 145 146 static void process_recv_sockets(struct work_struct *work); 147 static void process_send_sockets(struct work_struct *work); 148 149 /* 150 * If 'allocation' is zero then we don't attempt to create a new 151 * connection structure for this node. 152 */ 153 static struct connection *__nodeid2con(int nodeid, gfp_t alloc) 154 { 155 struct connection *con = NULL; 156 int r; 157 int n; 158 159 con = idr_find(&connections_idr, nodeid); 160 if (con || !alloc) 161 return con; 162 163 r = idr_pre_get(&connections_idr, alloc); 164 if (!r) 165 return NULL; 166 167 con = kmem_cache_zalloc(con_cache, alloc); 168 if (!con) 169 return NULL; 170 171 r = idr_get_new_above(&connections_idr, con, nodeid, &n); 172 if (r) { 173 kmem_cache_free(con_cache, con); 174 return NULL; 175 } 176 177 if (n != nodeid) { 178 idr_remove(&connections_idr, n); 179 kmem_cache_free(con_cache, con); 180 return NULL; 181 } 182 183 con->nodeid = nodeid; 184 mutex_init(&con->sock_mutex); 185 INIT_LIST_HEAD(&con->writequeue); 186 spin_lock_init(&con->writequeue_lock); 187 INIT_WORK(&con->swork, process_send_sockets); 188 INIT_WORK(&con->rwork, process_recv_sockets); 189 190 /* Setup action pointers for child sockets */ 191 if (con->nodeid) { 192 struct connection *zerocon = idr_find(&connections_idr, 0); 193 194 con->connect_action = zerocon->connect_action; 195 if (!con->rx_action) 196 con->rx_action = zerocon->rx_action; 197 } 198 199 if (nodeid > max_nodeid) 200 max_nodeid = nodeid; 201 202 return con; 203 } 204 205 static struct connection *nodeid2con(int nodeid, gfp_t allocation) 206 { 207 struct connection *con; 208 209 mutex_lock(&connections_lock); 210 con = __nodeid2con(nodeid, allocation); 211 mutex_unlock(&connections_lock); 212 213 return con; 214 } 215 216 /* This is a bit drastic, but only called when things go wrong */ 217 static struct connection *assoc2con(int assoc_id) 218 { 219 int i; 220 struct connection *con; 221 222 mutex_lock(&connections_lock); 223 for (i=0; i<=max_nodeid; i++) { 224 con = __nodeid2con(i, 0); 225 if (con && con->sctp_assoc == assoc_id) { 226 mutex_unlock(&connections_lock); 227 return con; 228 } 229 } 230 mutex_unlock(&connections_lock); 231 return NULL; 232 } 233 234 static int nodeid_to_addr(int nodeid, struct sockaddr *retaddr) 235 { 236 struct sockaddr_storage addr; 237 int error; 238 239 if (!dlm_local_count) 240 return -1; 241 242 error = dlm_nodeid_to_addr(nodeid, &addr); 243 if (error) 244 return error; 245 246 if (dlm_local_addr[0]->ss_family == AF_INET) { 247 struct sockaddr_in *in4 = (struct sockaddr_in *) &addr; 248 struct sockaddr_in *ret4 = (struct sockaddr_in *) retaddr; 249 ret4->sin_addr.s_addr = in4->sin_addr.s_addr; 250 } else { 251 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) &addr; 252 struct sockaddr_in6 *ret6 = (struct sockaddr_in6 *) retaddr; 253 memcpy(&ret6->sin6_addr, &in6->sin6_addr, 254 sizeof(in6->sin6_addr)); 255 } 256 257 return 0; 258 } 259 260 /* Data available on socket or listen socket received a connect */ 261 static void lowcomms_data_ready(struct sock *sk, int count_unused) 262 { 263 struct connection *con = sock2con(sk); 264 if (con && !test_and_set_bit(CF_READ_PENDING, &con->flags)) 265 queue_work(recv_workqueue, &con->rwork); 266 } 267 268 static void lowcomms_write_space(struct sock *sk) 269 { 270 struct connection *con = sock2con(sk); 271 272 if (con && !test_and_set_bit(CF_WRITE_PENDING, &con->flags)) 273 queue_work(send_workqueue, &con->swork); 274 } 275 276 static inline void lowcomms_connect_sock(struct connection *con) 277 { 278 if (!test_and_set_bit(CF_CONNECT_PENDING, &con->flags)) 279 queue_work(send_workqueue, &con->swork); 280 } 281 282 static void lowcomms_state_change(struct sock *sk) 283 { 284 if (sk->sk_state == TCP_ESTABLISHED) 285 lowcomms_write_space(sk); 286 } 287 288 /* Make a socket active */ 289 static int add_sock(struct socket *sock, struct connection *con) 290 { 291 con->sock = sock; 292 293 /* Install a data_ready callback */ 294 con->sock->sk->sk_data_ready = lowcomms_data_ready; 295 con->sock->sk->sk_write_space = lowcomms_write_space; 296 con->sock->sk->sk_state_change = lowcomms_state_change; 297 con->sock->sk->sk_user_data = con; 298 con->sock->sk->sk_allocation = GFP_NOFS; 299 return 0; 300 } 301 302 /* Add the port number to an IPv6 or 4 sockaddr and return the address 303 length */ 304 static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port, 305 int *addr_len) 306 { 307 saddr->ss_family = dlm_local_addr[0]->ss_family; 308 if (saddr->ss_family == AF_INET) { 309 struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr; 310 in4_addr->sin_port = cpu_to_be16(port); 311 *addr_len = sizeof(struct sockaddr_in); 312 memset(&in4_addr->sin_zero, 0, sizeof(in4_addr->sin_zero)); 313 } else { 314 struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr; 315 in6_addr->sin6_port = cpu_to_be16(port); 316 *addr_len = sizeof(struct sockaddr_in6); 317 } 318 memset((char *)saddr + *addr_len, 0, sizeof(struct sockaddr_storage) - *addr_len); 319 } 320 321 /* Close a remote connection and tidy up */ 322 static void close_connection(struct connection *con, bool and_other) 323 { 324 mutex_lock(&con->sock_mutex); 325 326 if (con->sock) { 327 sock_release(con->sock); 328 con->sock = NULL; 329 } 330 if (con->othercon && and_other) { 331 /* Will only re-enter once. */ 332 close_connection(con->othercon, false); 333 } 334 if (con->rx_page) { 335 __free_page(con->rx_page); 336 con->rx_page = NULL; 337 } 338 339 con->retries = 0; 340 mutex_unlock(&con->sock_mutex); 341 } 342 343 /* We only send shutdown messages to nodes that are not part of the cluster */ 344 static void sctp_send_shutdown(sctp_assoc_t associd) 345 { 346 static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 347 struct msghdr outmessage; 348 struct cmsghdr *cmsg; 349 struct sctp_sndrcvinfo *sinfo; 350 int ret; 351 struct connection *con; 352 353 con = nodeid2con(0,0); 354 BUG_ON(con == NULL); 355 356 outmessage.msg_name = NULL; 357 outmessage.msg_namelen = 0; 358 outmessage.msg_control = outcmsg; 359 outmessage.msg_controllen = sizeof(outcmsg); 360 outmessage.msg_flags = MSG_EOR; 361 362 cmsg = CMSG_FIRSTHDR(&outmessage); 363 cmsg->cmsg_level = IPPROTO_SCTP; 364 cmsg->cmsg_type = SCTP_SNDRCV; 365 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo)); 366 outmessage.msg_controllen = cmsg->cmsg_len; 367 sinfo = CMSG_DATA(cmsg); 368 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo)); 369 370 sinfo->sinfo_flags |= MSG_EOF; 371 sinfo->sinfo_assoc_id = associd; 372 373 ret = kernel_sendmsg(con->sock, &outmessage, NULL, 0, 0); 374 375 if (ret != 0) 376 log_print("send EOF to node failed: %d", ret); 377 } 378 379 /* INIT failed but we don't know which node... 380 restart INIT on all pending nodes */ 381 static void sctp_init_failed(void) 382 { 383 int i; 384 struct connection *con; 385 386 mutex_lock(&connections_lock); 387 for (i=1; i<=max_nodeid; i++) { 388 con = __nodeid2con(i, 0); 389 if (!con) 390 continue; 391 con->sctp_assoc = 0; 392 if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) { 393 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) { 394 queue_work(send_workqueue, &con->swork); 395 } 396 } 397 } 398 mutex_unlock(&connections_lock); 399 } 400 401 /* Something happened to an association */ 402 static void process_sctp_notification(struct connection *con, 403 struct msghdr *msg, char *buf) 404 { 405 union sctp_notification *sn = (union sctp_notification *)buf; 406 407 if (sn->sn_header.sn_type == SCTP_ASSOC_CHANGE) { 408 switch (sn->sn_assoc_change.sac_state) { 409 410 case SCTP_COMM_UP: 411 case SCTP_RESTART: 412 { 413 /* Check that the new node is in the lockspace */ 414 struct sctp_prim prim; 415 int nodeid; 416 int prim_len, ret; 417 int addr_len; 418 struct connection *new_con; 419 struct file *file; 420 sctp_peeloff_arg_t parg; 421 int parglen = sizeof(parg); 422 423 /* 424 * We get this before any data for an association. 425 * We verify that the node is in the cluster and 426 * then peel off a socket for it. 427 */ 428 if ((int)sn->sn_assoc_change.sac_assoc_id <= 0) { 429 log_print("COMM_UP for invalid assoc ID %d", 430 (int)sn->sn_assoc_change.sac_assoc_id); 431 sctp_init_failed(); 432 return; 433 } 434 memset(&prim, 0, sizeof(struct sctp_prim)); 435 prim_len = sizeof(struct sctp_prim); 436 prim.ssp_assoc_id = sn->sn_assoc_change.sac_assoc_id; 437 438 ret = kernel_getsockopt(con->sock, 439 IPPROTO_SCTP, 440 SCTP_PRIMARY_ADDR, 441 (char*)&prim, 442 &prim_len); 443 if (ret < 0) { 444 log_print("getsockopt/sctp_primary_addr on " 445 "new assoc %d failed : %d", 446 (int)sn->sn_assoc_change.sac_assoc_id, 447 ret); 448 449 /* Retry INIT later */ 450 new_con = assoc2con(sn->sn_assoc_change.sac_assoc_id); 451 if (new_con) 452 clear_bit(CF_CONNECT_PENDING, &con->flags); 453 return; 454 } 455 make_sockaddr(&prim.ssp_addr, 0, &addr_len); 456 if (dlm_addr_to_nodeid(&prim.ssp_addr, &nodeid)) { 457 int i; 458 unsigned char *b=(unsigned char *)&prim.ssp_addr; 459 log_print("reject connect from unknown addr"); 460 for (i=0; i<sizeof(struct sockaddr_storage);i++) 461 printk("%02x ", b[i]); 462 printk("\n"); 463 sctp_send_shutdown(prim.ssp_assoc_id); 464 return; 465 } 466 467 new_con = nodeid2con(nodeid, GFP_KERNEL); 468 if (!new_con) 469 return; 470 471 /* Peel off a new sock */ 472 parg.associd = sn->sn_assoc_change.sac_assoc_id; 473 ret = kernel_getsockopt(con->sock, IPPROTO_SCTP, 474 SCTP_SOCKOPT_PEELOFF, 475 (void *)&parg, &parglen); 476 if (ret) { 477 log_print("Can't peel off a socket for " 478 "connection %d to node %d: err=%d\n", 479 parg.associd, nodeid, ret); 480 } 481 file = fget(parg.sd); 482 new_con->sock = SOCKET_I(file->f_dentry->d_inode); 483 add_sock(new_con->sock, new_con); 484 fput(file); 485 put_unused_fd(parg.sd); 486 487 log_print("got new/restarted association %d nodeid %d", 488 (int)sn->sn_assoc_change.sac_assoc_id, nodeid); 489 490 /* Send any pending writes */ 491 clear_bit(CF_CONNECT_PENDING, &new_con->flags); 492 clear_bit(CF_INIT_PENDING, &con->flags); 493 if (!test_and_set_bit(CF_WRITE_PENDING, &new_con->flags)) { 494 queue_work(send_workqueue, &new_con->swork); 495 } 496 if (!test_and_set_bit(CF_READ_PENDING, &new_con->flags)) 497 queue_work(recv_workqueue, &new_con->rwork); 498 } 499 break; 500 501 case SCTP_COMM_LOST: 502 case SCTP_SHUTDOWN_COMP: 503 { 504 con = assoc2con(sn->sn_assoc_change.sac_assoc_id); 505 if (con) { 506 con->sctp_assoc = 0; 507 } 508 } 509 break; 510 511 /* We don't know which INIT failed, so clear the PENDING flags 512 * on them all. if assoc_id is zero then it will then try 513 * again */ 514 515 case SCTP_CANT_STR_ASSOC: 516 { 517 log_print("Can't start SCTP association - retrying"); 518 sctp_init_failed(); 519 } 520 break; 521 522 default: 523 log_print("unexpected SCTP assoc change id=%d state=%d", 524 (int)sn->sn_assoc_change.sac_assoc_id, 525 sn->sn_assoc_change.sac_state); 526 } 527 } 528 } 529 530 /* Data received from remote end */ 531 static int receive_from_sock(struct connection *con) 532 { 533 int ret = 0; 534 struct msghdr msg = {}; 535 struct kvec iov[2]; 536 unsigned len; 537 int r; 538 int call_again_soon = 0; 539 int nvec; 540 char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 541 542 mutex_lock(&con->sock_mutex); 543 544 if (con->sock == NULL) { 545 ret = -EAGAIN; 546 goto out_close; 547 } 548 549 if (con->rx_page == NULL) { 550 /* 551 * This doesn't need to be atomic, but I think it should 552 * improve performance if it is. 553 */ 554 con->rx_page = alloc_page(GFP_ATOMIC); 555 if (con->rx_page == NULL) 556 goto out_resched; 557 cbuf_init(&con->cb, PAGE_CACHE_SIZE); 558 } 559 560 /* Only SCTP needs these really */ 561 memset(&incmsg, 0, sizeof(incmsg)); 562 msg.msg_control = incmsg; 563 msg.msg_controllen = sizeof(incmsg); 564 565 /* 566 * iov[0] is the bit of the circular buffer between the current end 567 * point (cb.base + cb.len) and the end of the buffer. 568 */ 569 iov[0].iov_len = con->cb.base - cbuf_data(&con->cb); 570 iov[0].iov_base = page_address(con->rx_page) + cbuf_data(&con->cb); 571 iov[1].iov_len = 0; 572 nvec = 1; 573 574 /* 575 * iov[1] is the bit of the circular buffer between the start of the 576 * buffer and the start of the currently used section (cb.base) 577 */ 578 if (cbuf_data(&con->cb) >= con->cb.base) { 579 iov[0].iov_len = PAGE_CACHE_SIZE - cbuf_data(&con->cb); 580 iov[1].iov_len = con->cb.base; 581 iov[1].iov_base = page_address(con->rx_page); 582 nvec = 2; 583 } 584 len = iov[0].iov_len + iov[1].iov_len; 585 586 r = ret = kernel_recvmsg(con->sock, &msg, iov, nvec, len, 587 MSG_DONTWAIT | MSG_NOSIGNAL); 588 if (ret <= 0) 589 goto out_close; 590 591 /* Process SCTP notifications */ 592 if (msg.msg_flags & MSG_NOTIFICATION) { 593 msg.msg_control = incmsg; 594 msg.msg_controllen = sizeof(incmsg); 595 596 process_sctp_notification(con, &msg, 597 page_address(con->rx_page) + con->cb.base); 598 mutex_unlock(&con->sock_mutex); 599 return 0; 600 } 601 BUG_ON(con->nodeid == 0); 602 603 if (ret == len) 604 call_again_soon = 1; 605 cbuf_add(&con->cb, ret); 606 ret = dlm_process_incoming_buffer(con->nodeid, 607 page_address(con->rx_page), 608 con->cb.base, con->cb.len, 609 PAGE_CACHE_SIZE); 610 if (ret == -EBADMSG) { 611 log_print("lowcomms: addr=%p, base=%u, len=%u, " 612 "iov_len=%u, iov_base[0]=%p, read=%d", 613 page_address(con->rx_page), con->cb.base, con->cb.len, 614 len, iov[0].iov_base, r); 615 } 616 if (ret < 0) 617 goto out_close; 618 cbuf_eat(&con->cb, ret); 619 620 if (cbuf_empty(&con->cb) && !call_again_soon) { 621 __free_page(con->rx_page); 622 con->rx_page = NULL; 623 } 624 625 if (call_again_soon) 626 goto out_resched; 627 mutex_unlock(&con->sock_mutex); 628 return 0; 629 630 out_resched: 631 if (!test_and_set_bit(CF_READ_PENDING, &con->flags)) 632 queue_work(recv_workqueue, &con->rwork); 633 mutex_unlock(&con->sock_mutex); 634 return -EAGAIN; 635 636 out_close: 637 mutex_unlock(&con->sock_mutex); 638 if (ret != -EAGAIN) { 639 close_connection(con, false); 640 /* Reconnect when there is something to send */ 641 } 642 /* Don't return success if we really got EOF */ 643 if (ret == 0) 644 ret = -EAGAIN; 645 646 return ret; 647 } 648 649 /* Listening socket is busy, accept a connection */ 650 static int tcp_accept_from_sock(struct connection *con) 651 { 652 int result; 653 struct sockaddr_storage peeraddr; 654 struct socket *newsock; 655 int len; 656 int nodeid; 657 struct connection *newcon; 658 struct connection *addcon; 659 660 memset(&peeraddr, 0, sizeof(peeraddr)); 661 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 662 IPPROTO_TCP, &newsock); 663 if (result < 0) 664 return -ENOMEM; 665 666 mutex_lock_nested(&con->sock_mutex, 0); 667 668 result = -ENOTCONN; 669 if (con->sock == NULL) 670 goto accept_err; 671 672 newsock->type = con->sock->type; 673 newsock->ops = con->sock->ops; 674 675 result = con->sock->ops->accept(con->sock, newsock, O_NONBLOCK); 676 if (result < 0) 677 goto accept_err; 678 679 /* Get the connected socket's peer */ 680 memset(&peeraddr, 0, sizeof(peeraddr)); 681 if (newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr, 682 &len, 2)) { 683 result = -ECONNABORTED; 684 goto accept_err; 685 } 686 687 /* Get the new node's NODEID */ 688 make_sockaddr(&peeraddr, 0, &len); 689 if (dlm_addr_to_nodeid(&peeraddr, &nodeid)) { 690 log_print("connect from non cluster node"); 691 sock_release(newsock); 692 mutex_unlock(&con->sock_mutex); 693 return -1; 694 } 695 696 log_print("got connection from %d", nodeid); 697 698 /* Check to see if we already have a connection to this node. This 699 * could happen if the two nodes initiate a connection at roughly 700 * the same time and the connections cross on the wire. 701 * In this case we store the incoming one in "othercon" 702 */ 703 newcon = nodeid2con(nodeid, GFP_KERNEL); 704 if (!newcon) { 705 result = -ENOMEM; 706 goto accept_err; 707 } 708 mutex_lock_nested(&newcon->sock_mutex, 1); 709 if (newcon->sock) { 710 struct connection *othercon = newcon->othercon; 711 712 if (!othercon) { 713 othercon = kmem_cache_zalloc(con_cache, GFP_KERNEL); 714 if (!othercon) { 715 log_print("failed to allocate incoming socket"); 716 mutex_unlock(&newcon->sock_mutex); 717 result = -ENOMEM; 718 goto accept_err; 719 } 720 othercon->nodeid = nodeid; 721 othercon->rx_action = receive_from_sock; 722 mutex_init(&othercon->sock_mutex); 723 INIT_WORK(&othercon->swork, process_send_sockets); 724 INIT_WORK(&othercon->rwork, process_recv_sockets); 725 set_bit(CF_IS_OTHERCON, &othercon->flags); 726 } 727 if (!othercon->sock) { 728 newcon->othercon = othercon; 729 othercon->sock = newsock; 730 newsock->sk->sk_user_data = othercon; 731 add_sock(newsock, othercon); 732 addcon = othercon; 733 } 734 else { 735 printk("Extra connection from node %d attempted\n", nodeid); 736 result = -EAGAIN; 737 mutex_unlock(&newcon->sock_mutex); 738 goto accept_err; 739 } 740 } 741 else { 742 newsock->sk->sk_user_data = newcon; 743 newcon->rx_action = receive_from_sock; 744 add_sock(newsock, newcon); 745 addcon = newcon; 746 } 747 748 mutex_unlock(&newcon->sock_mutex); 749 750 /* 751 * Add it to the active queue in case we got data 752 * beween processing the accept adding the socket 753 * to the read_sockets list 754 */ 755 if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags)) 756 queue_work(recv_workqueue, &addcon->rwork); 757 mutex_unlock(&con->sock_mutex); 758 759 return 0; 760 761 accept_err: 762 mutex_unlock(&con->sock_mutex); 763 sock_release(newsock); 764 765 if (result != -EAGAIN) 766 log_print("error accepting connection from node: %d", result); 767 return result; 768 } 769 770 static void free_entry(struct writequeue_entry *e) 771 { 772 __free_page(e->page); 773 kfree(e); 774 } 775 776 /* Initiate an SCTP association. 777 This is a special case of send_to_sock() in that we don't yet have a 778 peeled-off socket for this association, so we use the listening socket 779 and add the primary IP address of the remote node. 780 */ 781 static void sctp_init_assoc(struct connection *con) 782 { 783 struct sockaddr_storage rem_addr; 784 char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 785 struct msghdr outmessage; 786 struct cmsghdr *cmsg; 787 struct sctp_sndrcvinfo *sinfo; 788 struct connection *base_con; 789 struct writequeue_entry *e; 790 int len, offset; 791 int ret; 792 int addrlen; 793 struct kvec iov[1]; 794 795 if (test_and_set_bit(CF_INIT_PENDING, &con->flags)) 796 return; 797 798 if (con->retries++ > MAX_CONNECT_RETRIES) 799 return; 800 801 log_print("Initiating association with node %d", con->nodeid); 802 803 if (nodeid_to_addr(con->nodeid, (struct sockaddr *)&rem_addr)) { 804 log_print("no address for nodeid %d", con->nodeid); 805 return; 806 } 807 base_con = nodeid2con(0, 0); 808 BUG_ON(base_con == NULL); 809 810 make_sockaddr(&rem_addr, dlm_config.ci_tcp_port, &addrlen); 811 812 outmessage.msg_name = &rem_addr; 813 outmessage.msg_namelen = addrlen; 814 outmessage.msg_control = outcmsg; 815 outmessage.msg_controllen = sizeof(outcmsg); 816 outmessage.msg_flags = MSG_EOR; 817 818 spin_lock(&con->writequeue_lock); 819 e = list_entry(con->writequeue.next, struct writequeue_entry, 820 list); 821 822 BUG_ON((struct list_head *) e == &con->writequeue); 823 824 len = e->len; 825 offset = e->offset; 826 spin_unlock(&con->writequeue_lock); 827 828 /* Send the first block off the write queue */ 829 iov[0].iov_base = page_address(e->page)+offset; 830 iov[0].iov_len = len; 831 832 cmsg = CMSG_FIRSTHDR(&outmessage); 833 cmsg->cmsg_level = IPPROTO_SCTP; 834 cmsg->cmsg_type = SCTP_SNDRCV; 835 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo)); 836 sinfo = CMSG_DATA(cmsg); 837 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo)); 838 sinfo->sinfo_ppid = cpu_to_le32(dlm_our_nodeid()); 839 outmessage.msg_controllen = cmsg->cmsg_len; 840 841 ret = kernel_sendmsg(base_con->sock, &outmessage, iov, 1, len); 842 if (ret < 0) { 843 log_print("Send first packet to node %d failed: %d", 844 con->nodeid, ret); 845 846 /* Try again later */ 847 clear_bit(CF_CONNECT_PENDING, &con->flags); 848 clear_bit(CF_INIT_PENDING, &con->flags); 849 } 850 else { 851 spin_lock(&con->writequeue_lock); 852 e->offset += ret; 853 e->len -= ret; 854 855 if (e->len == 0 && e->users == 0) { 856 list_del(&e->list); 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 sock_release(sock); 895 goto out_err; 896 } 897 898 sock->sk->sk_user_data = con; 899 con->rx_action = receive_from_sock; 900 con->connect_action = tcp_connect_to_sock; 901 add_sock(sock, con); 902 903 /* Bind to our cluster-known address connecting to avoid 904 routing problems */ 905 memcpy(&src_addr, dlm_local_addr[0], sizeof(src_addr)); 906 make_sockaddr(&src_addr, 0, &addr_len); 907 result = sock->ops->bind(sock, (struct sockaddr *) &src_addr, 908 addr_len); 909 if (result < 0) { 910 log_print("could not bind for connect: %d", result); 911 /* This *may* not indicate a critical error */ 912 } 913 914 make_sockaddr(&saddr, dlm_config.ci_tcp_port, &addr_len); 915 916 log_print("connecting to %d", con->nodeid); 917 result = 918 sock->ops->connect(sock, (struct sockaddr *)&saddr, addr_len, 919 O_NONBLOCK); 920 if (result == -EINPROGRESS) 921 result = 0; 922 if (result == 0) 923 goto out; 924 925 out_err: 926 if (con->sock) { 927 sock_release(con->sock); 928 con->sock = NULL; 929 } 930 /* 931 * Some errors are fatal and this list might need adjusting. For other 932 * errors we try again until the max number of retries is reached. 933 */ 934 if (result != -EHOSTUNREACH && result != -ENETUNREACH && 935 result != -ENETDOWN && result != -EINVAL 936 && result != -EPROTONOSUPPORT) { 937 lowcomms_connect_sock(con); 938 result = 0; 939 } 940 out: 941 mutex_unlock(&con->sock_mutex); 942 return; 943 } 944 945 static struct socket *tcp_create_listen_sock(struct connection *con, 946 struct sockaddr_storage *saddr) 947 { 948 struct socket *sock = NULL; 949 int result = 0; 950 int one = 1; 951 int addr_len; 952 953 if (dlm_local_addr[0]->ss_family == AF_INET) 954 addr_len = sizeof(struct sockaddr_in); 955 else 956 addr_len = sizeof(struct sockaddr_in6); 957 958 /* Create a socket to communicate with */ 959 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 960 IPPROTO_TCP, &sock); 961 if (result < 0) { 962 log_print("Can't create listening comms socket"); 963 goto create_out; 964 } 965 966 result = kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, 967 (char *)&one, sizeof(one)); 968 969 if (result < 0) { 970 log_print("Failed to set SO_REUSEADDR on socket: %d", result); 971 } 972 sock->sk->sk_user_data = con; 973 con->rx_action = tcp_accept_from_sock; 974 con->connect_action = tcp_connect_to_sock; 975 con->sock = sock; 976 977 /* Bind to our port */ 978 make_sockaddr(saddr, dlm_config.ci_tcp_port, &addr_len); 979 result = sock->ops->bind(sock, (struct sockaddr *) saddr, addr_len); 980 if (result < 0) { 981 log_print("Can't bind to port %d", dlm_config.ci_tcp_port); 982 sock_release(sock); 983 sock = NULL; 984 con->sock = NULL; 985 goto create_out; 986 } 987 result = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, 988 (char *)&one, sizeof(one)); 989 if (result < 0) { 990 log_print("Set keepalive failed: %d", result); 991 } 992 993 result = sock->ops->listen(sock, 5); 994 if (result < 0) { 995 log_print("Can't listen on port %d", dlm_config.ci_tcp_port); 996 sock_release(sock); 997 sock = NULL; 998 goto create_out; 999 } 1000 1001 create_out: 1002 return sock; 1003 } 1004 1005 /* Get local addresses */ 1006 static void init_local(void) 1007 { 1008 struct sockaddr_storage sas, *addr; 1009 int i; 1010 1011 dlm_local_count = 0; 1012 for (i = 0; i < DLM_MAX_ADDR_COUNT - 1; i++) { 1013 if (dlm_our_addr(&sas, i)) 1014 break; 1015 1016 addr = kmalloc(sizeof(*addr), GFP_KERNEL); 1017 if (!addr) 1018 break; 1019 memcpy(addr, &sas, sizeof(*addr)); 1020 dlm_local_addr[dlm_local_count++] = addr; 1021 } 1022 } 1023 1024 /* Bind to an IP address. SCTP allows multiple address so it can do 1025 multi-homing */ 1026 static int add_sctp_bind_addr(struct connection *sctp_con, 1027 struct sockaddr_storage *addr, 1028 int addr_len, int num) 1029 { 1030 int result = 0; 1031 1032 if (num == 1) 1033 result = kernel_bind(sctp_con->sock, 1034 (struct sockaddr *) addr, 1035 addr_len); 1036 else 1037 result = kernel_setsockopt(sctp_con->sock, SOL_SCTP, 1038 SCTP_SOCKOPT_BINDX_ADD, 1039 (char *)addr, addr_len); 1040 1041 if (result < 0) 1042 log_print("Can't bind to port %d addr number %d", 1043 dlm_config.ci_tcp_port, num); 1044 1045 return result; 1046 } 1047 1048 /* Initialise SCTP socket and bind to all interfaces */ 1049 static int sctp_listen_for_all(void) 1050 { 1051 struct socket *sock = NULL; 1052 struct sockaddr_storage localaddr; 1053 struct sctp_event_subscribe subscribe; 1054 int result = -EINVAL, num = 1, i, addr_len; 1055 struct connection *con = nodeid2con(0, GFP_KERNEL); 1056 int bufsize = NEEDED_RMEM; 1057 1058 if (!con) 1059 return -ENOMEM; 1060 1061 log_print("Using SCTP for communications"); 1062 1063 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_SEQPACKET, 1064 IPPROTO_SCTP, &sock); 1065 if (result < 0) { 1066 log_print("Can't create comms socket, check SCTP is loaded"); 1067 goto out; 1068 } 1069 1070 /* Listen for events */ 1071 memset(&subscribe, 0, sizeof(subscribe)); 1072 subscribe.sctp_data_io_event = 1; 1073 subscribe.sctp_association_event = 1; 1074 subscribe.sctp_send_failure_event = 1; 1075 subscribe.sctp_shutdown_event = 1; 1076 subscribe.sctp_partial_delivery_event = 1; 1077 1078 result = kernel_setsockopt(sock, SOL_SOCKET, SO_RCVBUFFORCE, 1079 (char *)&bufsize, sizeof(bufsize)); 1080 if (result) 1081 log_print("Error increasing buffer space on socket %d", result); 1082 1083 result = kernel_setsockopt(sock, SOL_SCTP, SCTP_EVENTS, 1084 (char *)&subscribe, sizeof(subscribe)); 1085 if (result < 0) { 1086 log_print("Failed to set SCTP_EVENTS on socket: result=%d", 1087 result); 1088 goto create_delsock; 1089 } 1090 1091 /* Init con struct */ 1092 sock->sk->sk_user_data = con; 1093 con->sock = sock; 1094 con->sock->sk->sk_data_ready = lowcomms_data_ready; 1095 con->rx_action = receive_from_sock; 1096 con->connect_action = sctp_init_assoc; 1097 1098 /* Bind to all interfaces. */ 1099 for (i = 0; i < dlm_local_count; i++) { 1100 memcpy(&localaddr, dlm_local_addr[i], sizeof(localaddr)); 1101 make_sockaddr(&localaddr, dlm_config.ci_tcp_port, &addr_len); 1102 1103 result = add_sctp_bind_addr(con, &localaddr, addr_len, num); 1104 if (result) 1105 goto create_delsock; 1106 ++num; 1107 } 1108 1109 result = sock->ops->listen(sock, 5); 1110 if (result < 0) { 1111 log_print("Can't set socket listening"); 1112 goto create_delsock; 1113 } 1114 1115 return 0; 1116 1117 create_delsock: 1118 sock_release(sock); 1119 con->sock = NULL; 1120 out: 1121 return result; 1122 } 1123 1124 static int tcp_listen_for_all(void) 1125 { 1126 struct socket *sock = NULL; 1127 struct connection *con = nodeid2con(0, GFP_KERNEL); 1128 int result = -EINVAL; 1129 1130 if (!con) 1131 return -ENOMEM; 1132 1133 /* We don't support multi-homed hosts */ 1134 if (dlm_local_addr[1] != NULL) { 1135 log_print("TCP protocol can't handle multi-homed hosts, " 1136 "try SCTP"); 1137 return -EINVAL; 1138 } 1139 1140 log_print("Using TCP for communications"); 1141 1142 sock = tcp_create_listen_sock(con, dlm_local_addr[0]); 1143 if (sock) { 1144 add_sock(sock, con); 1145 result = 0; 1146 } 1147 else { 1148 result = -EADDRINUSE; 1149 } 1150 1151 return result; 1152 } 1153 1154 1155 1156 static struct writequeue_entry *new_writequeue_entry(struct connection *con, 1157 gfp_t allocation) 1158 { 1159 struct writequeue_entry *entry; 1160 1161 entry = kmalloc(sizeof(struct writequeue_entry), allocation); 1162 if (!entry) 1163 return NULL; 1164 1165 entry->page = alloc_page(allocation); 1166 if (!entry->page) { 1167 kfree(entry); 1168 return NULL; 1169 } 1170 1171 entry->offset = 0; 1172 entry->len = 0; 1173 entry->end = 0; 1174 entry->users = 0; 1175 entry->con = con; 1176 1177 return entry; 1178 } 1179 1180 void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc) 1181 { 1182 struct connection *con; 1183 struct writequeue_entry *e; 1184 int offset = 0; 1185 int users = 0; 1186 1187 con = nodeid2con(nodeid, allocation); 1188 if (!con) 1189 return NULL; 1190 1191 spin_lock(&con->writequeue_lock); 1192 e = list_entry(con->writequeue.prev, struct writequeue_entry, list); 1193 if ((&e->list == &con->writequeue) || 1194 (PAGE_CACHE_SIZE - e->end < len)) { 1195 e = NULL; 1196 } else { 1197 offset = e->end; 1198 e->end += len; 1199 users = e->users++; 1200 } 1201 spin_unlock(&con->writequeue_lock); 1202 1203 if (e) { 1204 got_one: 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 spin_unlock(&con->writequeue_lock); 1234 1235 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) { 1236 queue_work(send_workqueue, &con->swork); 1237 } 1238 return; 1239 1240 out: 1241 spin_unlock(&con->writequeue_lock); 1242 return; 1243 } 1244 1245 /* Send a message */ 1246 static void send_to_sock(struct connection *con) 1247 { 1248 int ret = 0; 1249 ssize_t(*sendpage) (struct socket *, struct page *, int, size_t, int); 1250 const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL; 1251 struct writequeue_entry *e; 1252 int len, offset; 1253 1254 mutex_lock(&con->sock_mutex); 1255 if (con->sock == NULL) 1256 goto out_connect; 1257 1258 sendpage = con->sock->ops->sendpage; 1259 1260 spin_lock(&con->writequeue_lock); 1261 for (;;) { 1262 e = list_entry(con->writequeue.next, struct writequeue_entry, 1263 list); 1264 if ((struct list_head *) e == &con->writequeue) 1265 break; 1266 1267 len = e->len; 1268 offset = e->offset; 1269 BUG_ON(len == 0 && e->users == 0); 1270 spin_unlock(&con->writequeue_lock); 1271 1272 ret = 0; 1273 if (len) { 1274 ret = sendpage(con->sock, e->page, offset, len, 1275 msg_flags); 1276 if (ret == -EAGAIN || ret == 0) { 1277 cond_resched(); 1278 goto out; 1279 } 1280 if (ret <= 0) 1281 goto send_error; 1282 } 1283 /* Don't starve people filling buffers */ 1284 cond_resched(); 1285 1286 spin_lock(&con->writequeue_lock); 1287 e->offset += ret; 1288 e->len -= ret; 1289 1290 if (e->len == 0 && e->users == 0) { 1291 list_del(&e->list); 1292 free_entry(e); 1293 continue; 1294 } 1295 } 1296 spin_unlock(&con->writequeue_lock); 1297 out: 1298 mutex_unlock(&con->sock_mutex); 1299 return; 1300 1301 send_error: 1302 mutex_unlock(&con->sock_mutex); 1303 close_connection(con, false); 1304 lowcomms_connect_sock(con); 1305 return; 1306 1307 out_connect: 1308 mutex_unlock(&con->sock_mutex); 1309 if (!test_bit(CF_INIT_PENDING, &con->flags)) 1310 lowcomms_connect_sock(con); 1311 return; 1312 } 1313 1314 static void clean_one_writequeue(struct connection *con) 1315 { 1316 struct list_head *list; 1317 struct list_head *temp; 1318 1319 spin_lock(&con->writequeue_lock); 1320 list_for_each_safe(list, temp, &con->writequeue) { 1321 struct writequeue_entry *e = 1322 list_entry(list, struct writequeue_entry, list); 1323 list_del(&e->list); 1324 free_entry(e); 1325 } 1326 spin_unlock(&con->writequeue_lock); 1327 } 1328 1329 /* Called from recovery when it knows that a node has 1330 left the cluster */ 1331 int dlm_lowcomms_close(int nodeid) 1332 { 1333 struct connection *con; 1334 1335 log_print("closing connection to node %d", nodeid); 1336 con = nodeid2con(nodeid, 0); 1337 if (con) { 1338 clean_one_writequeue(con); 1339 close_connection(con, true); 1340 } 1341 return 0; 1342 } 1343 1344 /* Receive workqueue function */ 1345 static void process_recv_sockets(struct work_struct *work) 1346 { 1347 struct connection *con = container_of(work, struct connection, rwork); 1348 int err; 1349 1350 clear_bit(CF_READ_PENDING, &con->flags); 1351 do { 1352 err = con->rx_action(con); 1353 } while (!err); 1354 } 1355 1356 /* Send workqueue function */ 1357 static void process_send_sockets(struct work_struct *work) 1358 { 1359 struct connection *con = container_of(work, struct connection, swork); 1360 1361 if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) { 1362 con->connect_action(con); 1363 } 1364 clear_bit(CF_WRITE_PENDING, &con->flags); 1365 send_to_sock(con); 1366 } 1367 1368 1369 /* Discard all entries on the write queues */ 1370 static void clean_writequeues(void) 1371 { 1372 int nodeid; 1373 1374 for (nodeid = 1; nodeid <= max_nodeid; nodeid++) { 1375 struct connection *con = __nodeid2con(nodeid, 0); 1376 1377 if (con) 1378 clean_one_writequeue(con); 1379 } 1380 } 1381 1382 static void work_stop(void) 1383 { 1384 destroy_workqueue(recv_workqueue); 1385 destroy_workqueue(send_workqueue); 1386 } 1387 1388 static int work_start(void) 1389 { 1390 int error; 1391 recv_workqueue = create_workqueue("dlm_recv"); 1392 error = IS_ERR(recv_workqueue); 1393 if (error) { 1394 log_print("can't start dlm_recv %d", error); 1395 return error; 1396 } 1397 1398 send_workqueue = create_singlethread_workqueue("dlm_send"); 1399 error = IS_ERR(send_workqueue); 1400 if (error) { 1401 log_print("can't start dlm_send %d", error); 1402 destroy_workqueue(recv_workqueue); 1403 return error; 1404 } 1405 1406 return 0; 1407 } 1408 1409 void dlm_lowcomms_stop(void) 1410 { 1411 int i; 1412 struct connection *con; 1413 1414 /* Set all the flags to prevent any 1415 socket activity. 1416 */ 1417 mutex_lock(&connections_lock); 1418 for (i = 0; i <= max_nodeid; i++) { 1419 con = __nodeid2con(i, 0); 1420 if (con) { 1421 con->flags |= 0x0F; 1422 if (con->sock) 1423 con->sock->sk->sk_user_data = NULL; 1424 } 1425 } 1426 mutex_unlock(&connections_lock); 1427 1428 work_stop(); 1429 1430 mutex_lock(&connections_lock); 1431 clean_writequeues(); 1432 1433 for (i = 0; i <= max_nodeid; i++) { 1434 con = __nodeid2con(i, 0); 1435 if (con) { 1436 close_connection(con, true); 1437 if (con->othercon) 1438 kmem_cache_free(con_cache, con->othercon); 1439 kmem_cache_free(con_cache, con); 1440 } 1441 } 1442 max_nodeid = 0; 1443 mutex_unlock(&connections_lock); 1444 kmem_cache_destroy(con_cache); 1445 idr_init(&connections_idr); 1446 } 1447 1448 int dlm_lowcomms_start(void) 1449 { 1450 int error = -EINVAL; 1451 struct connection *con; 1452 1453 init_local(); 1454 if (!dlm_local_count) { 1455 error = -ENOTCONN; 1456 log_print("no local IP address has been set"); 1457 goto out; 1458 } 1459 1460 error = -ENOMEM; 1461 con_cache = kmem_cache_create("dlm_conn", sizeof(struct connection), 1462 __alignof__(struct connection), 0, 1463 NULL); 1464 if (!con_cache) 1465 goto out; 1466 1467 /* Start listening */ 1468 if (dlm_config.ci_protocol == 0) 1469 error = tcp_listen_for_all(); 1470 else 1471 error = sctp_listen_for_all(); 1472 if (error) 1473 goto fail_unlisten; 1474 1475 error = work_start(); 1476 if (error) 1477 goto fail_unlisten; 1478 1479 return 0; 1480 1481 fail_unlisten: 1482 con = nodeid2con(0,0); 1483 if (con) { 1484 close_connection(con, false); 1485 kmem_cache_free(con_cache, con); 1486 } 1487 kmem_cache_destroy(con_cache); 1488 1489 out: 1490 return error; 1491 } 1492