lowcomms.c revision b36930dd508e00f0c5083bcd57d25de6d0375c76
1/****************************************************************************** 2******************************************************************************* 3** 4** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. 5** Copyright (C) 2004-2009 Red Hat, Inc. All rights reserved. 6** 7** This copyrighted material is made available to anyone wishing to use, 8** modify, copy, or redistribute it subject to the terms and conditions 9** of the GNU General Public License v.2. 10** 11******************************************************************************* 12******************************************************************************/ 13 14/* 15 * lowcomms.c 16 * 17 * This is the "low-level" comms layer. 18 * 19 * It is responsible for sending/receiving messages 20 * from other nodes in the cluster. 21 * 22 * Cluster nodes are referred to by their nodeids. nodeids are 23 * simply 32 bit numbers to the locking module - if they need to 24 * be expanded for the cluster infrastructure then that is its 25 * responsibility. It is this layer's 26 * responsibility to resolve these into IP address or 27 * whatever it needs for inter-node communication. 28 * 29 * The comms level is two kernel threads that deal mainly with 30 * the receiving of messages from other nodes and passing them 31 * up to the mid-level comms layer (which understands the 32 * message format) for execution by the locking core, and 33 * a send thread which does all the setting up of connections 34 * to remote nodes and the sending of data. Threads are not allowed 35 * to send their own data because it may cause them to wait in times 36 * of high load. Also, this way, the sending thread can collect together 37 * messages bound for one node and send them in one block. 38 * 39 * lowcomms will choose to use either TCP or SCTP as its transport layer 40 * depending on the configuration variable 'protocol'. This should be set 41 * to 0 (default) for TCP or 1 for SCTP. It should be configured using a 42 * cluster-wide mechanism as it must be the same on all nodes of the cluster 43 * for the DLM to function. 44 * 45 */ 46 47#include <asm/ioctls.h> 48#include <net/sock.h> 49#include <net/tcp.h> 50#include <linux/pagemap.h> 51#include <linux/file.h> 52#include <linux/mutex.h> 53#include <linux/sctp.h> 54#include <linux/slab.h> 55#include <net/sctp/user.h> 56#include <net/ipv6.h> 57 58#include "dlm_internal.h" 59#include "lowcomms.h" 60#include "midcomms.h" 61#include "config.h" 62 63#define NEEDED_RMEM (4*1024*1024) 64#define CONN_HASH_SIZE 32 65 66struct cbuf { 67 unsigned int base; 68 unsigned int len; 69 unsigned int mask; 70}; 71 72static void cbuf_add(struct cbuf *cb, int n) 73{ 74 cb->len += n; 75} 76 77static int cbuf_data(struct cbuf *cb) 78{ 79 return ((cb->base + cb->len) & cb->mask); 80} 81 82static void cbuf_init(struct cbuf *cb, int size) 83{ 84 cb->base = cb->len = 0; 85 cb->mask = size-1; 86} 87 88static void cbuf_eat(struct cbuf *cb, int n) 89{ 90 cb->len -= n; 91 cb->base += n; 92 cb->base &= cb->mask; 93} 94 95static bool cbuf_empty(struct cbuf *cb) 96{ 97 return cb->len == 0; 98} 99 100struct connection { 101 struct socket *sock; /* NULL if not connected */ 102 uint32_t nodeid; /* So we know who we are in the list */ 103 struct mutex sock_mutex; 104 unsigned long flags; 105#define CF_READ_PENDING 1 106#define CF_WRITE_PENDING 2 107#define CF_CONNECT_PENDING 3 108#define CF_INIT_PENDING 4 109#define CF_IS_OTHERCON 5 110#define CF_CLOSE 6 111#define CF_APP_LIMITED 7 112 struct list_head writequeue; /* List of outgoing writequeue_entries */ 113 spinlock_t writequeue_lock; 114 int (*rx_action) (struct connection *); /* What to do when active */ 115 void (*connect_action) (struct connection *); /* What to do to connect */ 116 struct page *rx_page; 117 struct cbuf cb; 118 int retries; 119#define MAX_CONNECT_RETRIES 3 120 int sctp_assoc; 121 struct hlist_node list; 122 struct connection *othercon; 123 struct work_struct rwork; /* Receive workqueue */ 124 struct work_struct swork; /* Send workqueue */ 125}; 126#define sock2con(x) ((struct connection *)(x)->sk_user_data) 127 128/* An entry waiting to be sent */ 129struct writequeue_entry { 130 struct list_head list; 131 struct page *page; 132 int offset; 133 int len; 134 int end; 135 int users; 136 struct connection *con; 137}; 138 139static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT]; 140static int dlm_local_count; 141 142/* Work queues */ 143static struct workqueue_struct *recv_workqueue; 144static struct workqueue_struct *send_workqueue; 145 146static struct hlist_head connection_hash[CONN_HASH_SIZE]; 147static DEFINE_MUTEX(connections_lock); 148static struct kmem_cache *con_cache; 149 150static void process_recv_sockets(struct work_struct *work); 151static void process_send_sockets(struct work_struct *work); 152 153 154/* This is deliberately very simple because most clusters have simple 155 sequential nodeids, so we should be able to go straight to a connection 156 struct in the array */ 157static inline int nodeid_hash(int nodeid) 158{ 159 return nodeid & (CONN_HASH_SIZE-1); 160} 161 162static struct connection *__find_con(int nodeid) 163{ 164 int r; 165 struct hlist_node *h; 166 struct connection *con; 167 168 r = nodeid_hash(nodeid); 169 170 hlist_for_each_entry(con, h, &connection_hash[r], list) { 171 if (con->nodeid == nodeid) 172 return con; 173 } 174 return NULL; 175} 176 177/* 178 * If 'allocation' is zero then we don't attempt to create a new 179 * connection structure for this node. 180 */ 181static struct connection *__nodeid2con(int nodeid, gfp_t alloc) 182{ 183 struct connection *con = NULL; 184 int r; 185 186 con = __find_con(nodeid); 187 if (con || !alloc) 188 return con; 189 190 con = kmem_cache_zalloc(con_cache, alloc); 191 if (!con) 192 return NULL; 193 194 r = nodeid_hash(nodeid); 195 hlist_add_head(&con->list, &connection_hash[r]); 196 197 con->nodeid = nodeid; 198 mutex_init(&con->sock_mutex); 199 INIT_LIST_HEAD(&con->writequeue); 200 spin_lock_init(&con->writequeue_lock); 201 INIT_WORK(&con->swork, process_send_sockets); 202 INIT_WORK(&con->rwork, process_recv_sockets); 203 204 /* Setup action pointers for child sockets */ 205 if (con->nodeid) { 206 struct connection *zerocon = __find_con(0); 207 208 con->connect_action = zerocon->connect_action; 209 if (!con->rx_action) 210 con->rx_action = zerocon->rx_action; 211 } 212 213 return con; 214} 215 216/* Loop round all connections */ 217static void foreach_conn(void (*conn_func)(struct connection *c)) 218{ 219 int i; 220 struct hlist_node *h, *n; 221 struct connection *con; 222 223 for (i = 0; i < CONN_HASH_SIZE; i++) { 224 hlist_for_each_entry_safe(con, h, n, &connection_hash[i], list){ 225 conn_func(con); 226 } 227 } 228} 229 230static struct connection *nodeid2con(int nodeid, gfp_t allocation) 231{ 232 struct connection *con; 233 234 mutex_lock(&connections_lock); 235 con = __nodeid2con(nodeid, allocation); 236 mutex_unlock(&connections_lock); 237 238 return con; 239} 240 241/* This is a bit drastic, but only called when things go wrong */ 242static struct connection *assoc2con(int assoc_id) 243{ 244 int i; 245 struct hlist_node *h; 246 struct connection *con; 247 248 mutex_lock(&connections_lock); 249 250 for (i = 0 ; i < CONN_HASH_SIZE; i++) { 251 hlist_for_each_entry(con, h, &connection_hash[i], list) { 252 if (con->sctp_assoc == assoc_id) { 253 mutex_unlock(&connections_lock); 254 return con; 255 } 256 } 257 } 258 mutex_unlock(&connections_lock); 259 return NULL; 260} 261 262static int nodeid_to_addr(int nodeid, struct sockaddr *retaddr) 263{ 264 struct sockaddr_storage addr; 265 int error; 266 267 if (!dlm_local_count) 268 return -1; 269 270 error = dlm_nodeid_to_addr(nodeid, &addr); 271 if (error) 272 return error; 273 274 if (dlm_local_addr[0]->ss_family == AF_INET) { 275 struct sockaddr_in *in4 = (struct sockaddr_in *) &addr; 276 struct sockaddr_in *ret4 = (struct sockaddr_in *) retaddr; 277 ret4->sin_addr.s_addr = in4->sin_addr.s_addr; 278 } else { 279 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) &addr; 280 struct sockaddr_in6 *ret6 = (struct sockaddr_in6 *) retaddr; 281 ipv6_addr_copy(&ret6->sin6_addr, &in6->sin6_addr); 282 } 283 284 return 0; 285} 286 287/* Data available on socket or listen socket received a connect */ 288static void lowcomms_data_ready(struct sock *sk, int count_unused) 289{ 290 struct connection *con = sock2con(sk); 291 if (con && !test_and_set_bit(CF_READ_PENDING, &con->flags)) 292 queue_work(recv_workqueue, &con->rwork); 293} 294 295static void lowcomms_write_space(struct sock *sk) 296{ 297 struct connection *con = sock2con(sk); 298 299 if (!con) 300 return; 301 302 clear_bit(SOCK_NOSPACE, &con->sock->flags); 303 304 if (test_and_clear_bit(CF_APP_LIMITED, &con->flags)) { 305 con->sock->sk->sk_write_pending--; 306 clear_bit(SOCK_ASYNC_NOSPACE, &con->sock->flags); 307 } 308 309 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) 310 queue_work(send_workqueue, &con->swork); 311} 312 313static inline void lowcomms_connect_sock(struct connection *con) 314{ 315 if (test_bit(CF_CLOSE, &con->flags)) 316 return; 317 if (!test_and_set_bit(CF_CONNECT_PENDING, &con->flags)) 318 queue_work(send_workqueue, &con->swork); 319} 320 321static void lowcomms_state_change(struct sock *sk) 322{ 323 if (sk->sk_state == TCP_ESTABLISHED) 324 lowcomms_write_space(sk); 325} 326 327int dlm_lowcomms_connect_node(int nodeid) 328{ 329 struct connection *con; 330 331 /* with sctp there's no connecting without sending */ 332 if (dlm_config.ci_protocol != 0) 333 return 0; 334 335 if (nodeid == dlm_our_nodeid()) 336 return 0; 337 338 con = nodeid2con(nodeid, GFP_NOFS); 339 if (!con) 340 return -ENOMEM; 341 lowcomms_connect_sock(con); 342 return 0; 343} 344 345/* Make a socket active */ 346static int add_sock(struct socket *sock, struct connection *con) 347{ 348 con->sock = sock; 349 350 /* Install a data_ready callback */ 351 con->sock->sk->sk_data_ready = lowcomms_data_ready; 352 con->sock->sk->sk_write_space = lowcomms_write_space; 353 con->sock->sk->sk_state_change = lowcomms_state_change; 354 con->sock->sk->sk_user_data = con; 355 con->sock->sk->sk_allocation = GFP_NOFS; 356 return 0; 357} 358 359/* Add the port number to an IPv6 or 4 sockaddr and return the address 360 length */ 361static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port, 362 int *addr_len) 363{ 364 saddr->ss_family = dlm_local_addr[0]->ss_family; 365 if (saddr->ss_family == AF_INET) { 366 struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr; 367 in4_addr->sin_port = cpu_to_be16(port); 368 *addr_len = sizeof(struct sockaddr_in); 369 memset(&in4_addr->sin_zero, 0, sizeof(in4_addr->sin_zero)); 370 } else { 371 struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr; 372 in6_addr->sin6_port = cpu_to_be16(port); 373 *addr_len = sizeof(struct sockaddr_in6); 374 } 375 memset((char *)saddr + *addr_len, 0, sizeof(struct sockaddr_storage) - *addr_len); 376} 377 378/* Close a remote connection and tidy up */ 379static void close_connection(struct connection *con, bool and_other) 380{ 381 mutex_lock(&con->sock_mutex); 382 383 if (con->sock) { 384 sock_release(con->sock); 385 con->sock = NULL; 386 } 387 if (con->othercon && and_other) { 388 /* Will only re-enter once. */ 389 close_connection(con->othercon, false); 390 } 391 if (con->rx_page) { 392 __free_page(con->rx_page); 393 con->rx_page = NULL; 394 } 395 396 con->retries = 0; 397 mutex_unlock(&con->sock_mutex); 398} 399 400/* We only send shutdown messages to nodes that are not part of the cluster */ 401static void sctp_send_shutdown(sctp_assoc_t associd) 402{ 403 static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 404 struct msghdr outmessage; 405 struct cmsghdr *cmsg; 406 struct sctp_sndrcvinfo *sinfo; 407 int ret; 408 struct connection *con; 409 410 con = nodeid2con(0,0); 411 BUG_ON(con == NULL); 412 413 outmessage.msg_name = NULL; 414 outmessage.msg_namelen = 0; 415 outmessage.msg_control = outcmsg; 416 outmessage.msg_controllen = sizeof(outcmsg); 417 outmessage.msg_flags = MSG_EOR; 418 419 cmsg = CMSG_FIRSTHDR(&outmessage); 420 cmsg->cmsg_level = IPPROTO_SCTP; 421 cmsg->cmsg_type = SCTP_SNDRCV; 422 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo)); 423 outmessage.msg_controllen = cmsg->cmsg_len; 424 sinfo = CMSG_DATA(cmsg); 425 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo)); 426 427 sinfo->sinfo_flags |= MSG_EOF; 428 sinfo->sinfo_assoc_id = associd; 429 430 ret = kernel_sendmsg(con->sock, &outmessage, NULL, 0, 0); 431 432 if (ret != 0) 433 log_print("send EOF to node failed: %d", ret); 434} 435 436static void sctp_init_failed_foreach(struct connection *con) 437{ 438 con->sctp_assoc = 0; 439 if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) { 440 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) 441 queue_work(send_workqueue, &con->swork); 442 } 443} 444 445/* INIT failed but we don't know which node... 446 restart INIT on all pending nodes */ 447static void sctp_init_failed(void) 448{ 449 mutex_lock(&connections_lock); 450 451 foreach_conn(sctp_init_failed_foreach); 452 453 mutex_unlock(&connections_lock); 454} 455 456/* Something happened to an association */ 457static void process_sctp_notification(struct connection *con, 458 struct msghdr *msg, char *buf) 459{ 460 union sctp_notification *sn = (union sctp_notification *)buf; 461 462 if (sn->sn_header.sn_type == SCTP_ASSOC_CHANGE) { 463 switch (sn->sn_assoc_change.sac_state) { 464 465 case SCTP_COMM_UP: 466 case SCTP_RESTART: 467 { 468 /* Check that the new node is in the lockspace */ 469 struct sctp_prim prim; 470 int nodeid; 471 int prim_len, ret; 472 int addr_len; 473 struct connection *new_con; 474 sctp_peeloff_arg_t parg; 475 int parglen = sizeof(parg); 476 int err; 477 478 /* 479 * We get this before any data for an association. 480 * We verify that the node is in the cluster and 481 * then peel off a socket for it. 482 */ 483 if ((int)sn->sn_assoc_change.sac_assoc_id <= 0) { 484 log_print("COMM_UP for invalid assoc ID %d", 485 (int)sn->sn_assoc_change.sac_assoc_id); 486 sctp_init_failed(); 487 return; 488 } 489 memset(&prim, 0, sizeof(struct sctp_prim)); 490 prim_len = sizeof(struct sctp_prim); 491 prim.ssp_assoc_id = sn->sn_assoc_change.sac_assoc_id; 492 493 ret = kernel_getsockopt(con->sock, 494 IPPROTO_SCTP, 495 SCTP_PRIMARY_ADDR, 496 (char*)&prim, 497 &prim_len); 498 if (ret < 0) { 499 log_print("getsockopt/sctp_primary_addr on " 500 "new assoc %d failed : %d", 501 (int)sn->sn_assoc_change.sac_assoc_id, 502 ret); 503 504 /* Retry INIT later */ 505 new_con = assoc2con(sn->sn_assoc_change.sac_assoc_id); 506 if (new_con) 507 clear_bit(CF_CONNECT_PENDING, &con->flags); 508 return; 509 } 510 make_sockaddr(&prim.ssp_addr, 0, &addr_len); 511 if (dlm_addr_to_nodeid(&prim.ssp_addr, &nodeid)) { 512 int i; 513 unsigned char *b=(unsigned char *)&prim.ssp_addr; 514 log_print("reject connect from unknown addr"); 515 for (i=0; i<sizeof(struct sockaddr_storage);i++) 516 printk("%02x ", b[i]); 517 printk("\n"); 518 sctp_send_shutdown(prim.ssp_assoc_id); 519 return; 520 } 521 522 new_con = nodeid2con(nodeid, GFP_NOFS); 523 if (!new_con) 524 return; 525 526 /* Peel off a new sock */ 527 parg.associd = sn->sn_assoc_change.sac_assoc_id; 528 ret = kernel_getsockopt(con->sock, IPPROTO_SCTP, 529 SCTP_SOCKOPT_PEELOFF, 530 (void *)&parg, &parglen); 531 if (ret < 0) { 532 log_print("Can't peel off a socket for " 533 "connection %d to node %d: err=%d", 534 parg.associd, nodeid, ret); 535 return; 536 } 537 new_con->sock = sockfd_lookup(parg.sd, &err); 538 if (!new_con->sock) { 539 log_print("sockfd_lookup error %d", err); 540 return; 541 } 542 add_sock(new_con->sock, new_con); 543 sockfd_put(new_con->sock); 544 545 log_print("connecting to %d sctp association %d", 546 nodeid, (int)sn->sn_assoc_change.sac_assoc_id); 547 548 /* Send any pending writes */ 549 clear_bit(CF_CONNECT_PENDING, &new_con->flags); 550 clear_bit(CF_INIT_PENDING, &con->flags); 551 if (!test_and_set_bit(CF_WRITE_PENDING, &new_con->flags)) { 552 queue_work(send_workqueue, &new_con->swork); 553 } 554 if (!test_and_set_bit(CF_READ_PENDING, &new_con->flags)) 555 queue_work(recv_workqueue, &new_con->rwork); 556 } 557 break; 558 559 case SCTP_COMM_LOST: 560 case SCTP_SHUTDOWN_COMP: 561 { 562 con = assoc2con(sn->sn_assoc_change.sac_assoc_id); 563 if (con) { 564 con->sctp_assoc = 0; 565 } 566 } 567 break; 568 569 /* We don't know which INIT failed, so clear the PENDING flags 570 * on them all. if assoc_id is zero then it will then try 571 * again */ 572 573 case SCTP_CANT_STR_ASSOC: 574 { 575 log_print("Can't start SCTP association - retrying"); 576 sctp_init_failed(); 577 } 578 break; 579 580 default: 581 log_print("unexpected SCTP assoc change id=%d state=%d", 582 (int)sn->sn_assoc_change.sac_assoc_id, 583 sn->sn_assoc_change.sac_state); 584 } 585 } 586} 587 588/* Data received from remote end */ 589static int receive_from_sock(struct connection *con) 590{ 591 int ret = 0; 592 struct msghdr msg = {}; 593 struct kvec iov[2]; 594 unsigned len; 595 int r; 596 int call_again_soon = 0; 597 int nvec; 598 char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 599 600 mutex_lock(&con->sock_mutex); 601 602 if (con->sock == NULL) { 603 ret = -EAGAIN; 604 goto out_close; 605 } 606 607 if (con->rx_page == NULL) { 608 /* 609 * This doesn't need to be atomic, but I think it should 610 * improve performance if it is. 611 */ 612 con->rx_page = alloc_page(GFP_ATOMIC); 613 if (con->rx_page == NULL) 614 goto out_resched; 615 cbuf_init(&con->cb, PAGE_CACHE_SIZE); 616 } 617 618 /* Only SCTP needs these really */ 619 memset(&incmsg, 0, sizeof(incmsg)); 620 msg.msg_control = incmsg; 621 msg.msg_controllen = sizeof(incmsg); 622 623 /* 624 * iov[0] is the bit of the circular buffer between the current end 625 * point (cb.base + cb.len) and the end of the buffer. 626 */ 627 iov[0].iov_len = con->cb.base - cbuf_data(&con->cb); 628 iov[0].iov_base = page_address(con->rx_page) + cbuf_data(&con->cb); 629 iov[1].iov_len = 0; 630 nvec = 1; 631 632 /* 633 * iov[1] is the bit of the circular buffer between the start of the 634 * buffer and the start of the currently used section (cb.base) 635 */ 636 if (cbuf_data(&con->cb) >= con->cb.base) { 637 iov[0].iov_len = PAGE_CACHE_SIZE - cbuf_data(&con->cb); 638 iov[1].iov_len = con->cb.base; 639 iov[1].iov_base = page_address(con->rx_page); 640 nvec = 2; 641 } 642 len = iov[0].iov_len + iov[1].iov_len; 643 644 r = ret = kernel_recvmsg(con->sock, &msg, iov, nvec, len, 645 MSG_DONTWAIT | MSG_NOSIGNAL); 646 if (ret <= 0) 647 goto out_close; 648 649 /* Process SCTP notifications */ 650 if (msg.msg_flags & MSG_NOTIFICATION) { 651 msg.msg_control = incmsg; 652 msg.msg_controllen = sizeof(incmsg); 653 654 process_sctp_notification(con, &msg, 655 page_address(con->rx_page) + con->cb.base); 656 mutex_unlock(&con->sock_mutex); 657 return 0; 658 } 659 BUG_ON(con->nodeid == 0); 660 661 if (ret == len) 662 call_again_soon = 1; 663 cbuf_add(&con->cb, ret); 664 ret = dlm_process_incoming_buffer(con->nodeid, 665 page_address(con->rx_page), 666 con->cb.base, con->cb.len, 667 PAGE_CACHE_SIZE); 668 if (ret == -EBADMSG) { 669 log_print("lowcomms: addr=%p, base=%u, len=%u, " 670 "iov_len=%u, iov_base[0]=%p, read=%d", 671 page_address(con->rx_page), con->cb.base, con->cb.len, 672 len, iov[0].iov_base, r); 673 } 674 if (ret < 0) 675 goto out_close; 676 cbuf_eat(&con->cb, ret); 677 678 if (cbuf_empty(&con->cb) && !call_again_soon) { 679 __free_page(con->rx_page); 680 con->rx_page = NULL; 681 } 682 683 if (call_again_soon) 684 goto out_resched; 685 mutex_unlock(&con->sock_mutex); 686 return 0; 687 688out_resched: 689 if (!test_and_set_bit(CF_READ_PENDING, &con->flags)) 690 queue_work(recv_workqueue, &con->rwork); 691 mutex_unlock(&con->sock_mutex); 692 return -EAGAIN; 693 694out_close: 695 mutex_unlock(&con->sock_mutex); 696 if (ret != -EAGAIN) { 697 close_connection(con, false); 698 /* Reconnect when there is something to send */ 699 } 700 /* Don't return success if we really got EOF */ 701 if (ret == 0) 702 ret = -EAGAIN; 703 704 return ret; 705} 706 707/* Listening socket is busy, accept a connection */ 708static int tcp_accept_from_sock(struct connection *con) 709{ 710 int result; 711 struct sockaddr_storage peeraddr; 712 struct socket *newsock; 713 int len; 714 int nodeid; 715 struct connection *newcon; 716 struct connection *addcon; 717 718 memset(&peeraddr, 0, sizeof(peeraddr)); 719 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 720 IPPROTO_TCP, &newsock); 721 if (result < 0) 722 return -ENOMEM; 723 724 mutex_lock_nested(&con->sock_mutex, 0); 725 726 result = -ENOTCONN; 727 if (con->sock == NULL) 728 goto accept_err; 729 730 newsock->type = con->sock->type; 731 newsock->ops = con->sock->ops; 732 733 result = con->sock->ops->accept(con->sock, newsock, O_NONBLOCK); 734 if (result < 0) 735 goto accept_err; 736 737 /* Get the connected socket's peer */ 738 memset(&peeraddr, 0, sizeof(peeraddr)); 739 if (newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr, 740 &len, 2)) { 741 result = -ECONNABORTED; 742 goto accept_err; 743 } 744 745 /* Get the new node's NODEID */ 746 make_sockaddr(&peeraddr, 0, &len); 747 if (dlm_addr_to_nodeid(&peeraddr, &nodeid)) { 748 log_print("connect from non cluster node"); 749 sock_release(newsock); 750 mutex_unlock(&con->sock_mutex); 751 return -1; 752 } 753 754 log_print("got connection from %d", nodeid); 755 756 /* Check to see if we already have a connection to this node. This 757 * could happen if the two nodes initiate a connection at roughly 758 * the same time and the connections cross on the wire. 759 * In this case we store the incoming one in "othercon" 760 */ 761 newcon = nodeid2con(nodeid, GFP_NOFS); 762 if (!newcon) { 763 result = -ENOMEM; 764 goto accept_err; 765 } 766 mutex_lock_nested(&newcon->sock_mutex, 1); 767 if (newcon->sock) { 768 struct connection *othercon = newcon->othercon; 769 770 if (!othercon) { 771 othercon = kmem_cache_zalloc(con_cache, GFP_NOFS); 772 if (!othercon) { 773 log_print("failed to allocate incoming socket"); 774 mutex_unlock(&newcon->sock_mutex); 775 result = -ENOMEM; 776 goto accept_err; 777 } 778 othercon->nodeid = nodeid; 779 othercon->rx_action = receive_from_sock; 780 mutex_init(&othercon->sock_mutex); 781 INIT_WORK(&othercon->swork, process_send_sockets); 782 INIT_WORK(&othercon->rwork, process_recv_sockets); 783 set_bit(CF_IS_OTHERCON, &othercon->flags); 784 } 785 if (!othercon->sock) { 786 newcon->othercon = othercon; 787 othercon->sock = newsock; 788 newsock->sk->sk_user_data = othercon; 789 add_sock(newsock, othercon); 790 addcon = othercon; 791 } 792 else { 793 printk("Extra connection from node %d attempted\n", nodeid); 794 result = -EAGAIN; 795 mutex_unlock(&newcon->sock_mutex); 796 goto accept_err; 797 } 798 } 799 else { 800 newsock->sk->sk_user_data = newcon; 801 newcon->rx_action = receive_from_sock; 802 add_sock(newsock, newcon); 803 addcon = newcon; 804 } 805 806 mutex_unlock(&newcon->sock_mutex); 807 808 /* 809 * Add it to the active queue in case we got data 810 * beween processing the accept adding the socket 811 * to the read_sockets list 812 */ 813 if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags)) 814 queue_work(recv_workqueue, &addcon->rwork); 815 mutex_unlock(&con->sock_mutex); 816 817 return 0; 818 819accept_err: 820 mutex_unlock(&con->sock_mutex); 821 sock_release(newsock); 822 823 if (result != -EAGAIN) 824 log_print("error accepting connection from node: %d", result); 825 return result; 826} 827 828static void free_entry(struct writequeue_entry *e) 829{ 830 __free_page(e->page); 831 kfree(e); 832} 833 834/* Initiate an SCTP association. 835 This is a special case of send_to_sock() in that we don't yet have a 836 peeled-off socket for this association, so we use the listening socket 837 and add the primary IP address of the remote node. 838 */ 839static void sctp_init_assoc(struct connection *con) 840{ 841 struct sockaddr_storage rem_addr; 842 char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 843 struct msghdr outmessage; 844 struct cmsghdr *cmsg; 845 struct sctp_sndrcvinfo *sinfo; 846 struct connection *base_con; 847 struct writequeue_entry *e; 848 int len, offset; 849 int ret; 850 int addrlen; 851 struct kvec iov[1]; 852 853 if (test_and_set_bit(CF_INIT_PENDING, &con->flags)) 854 return; 855 856 if (con->retries++ > MAX_CONNECT_RETRIES) 857 return; 858 859 if (nodeid_to_addr(con->nodeid, (struct sockaddr *)&rem_addr)) { 860 log_print("no address for nodeid %d", con->nodeid); 861 return; 862 } 863 base_con = nodeid2con(0, 0); 864 BUG_ON(base_con == NULL); 865 866 make_sockaddr(&rem_addr, dlm_config.ci_tcp_port, &addrlen); 867 868 outmessage.msg_name = &rem_addr; 869 outmessage.msg_namelen = addrlen; 870 outmessage.msg_control = outcmsg; 871 outmessage.msg_controllen = sizeof(outcmsg); 872 outmessage.msg_flags = MSG_EOR; 873 874 spin_lock(&con->writequeue_lock); 875 876 if (list_empty(&con->writequeue)) { 877 spin_unlock(&con->writequeue_lock); 878 log_print("writequeue empty for nodeid %d", con->nodeid); 879 return; 880 } 881 882 e = list_first_entry(&con->writequeue, struct writequeue_entry, list); 883 len = e->len; 884 offset = e->offset; 885 spin_unlock(&con->writequeue_lock); 886 887 /* Send the first block off the write queue */ 888 iov[0].iov_base = page_address(e->page)+offset; 889 iov[0].iov_len = len; 890 891 cmsg = CMSG_FIRSTHDR(&outmessage); 892 cmsg->cmsg_level = IPPROTO_SCTP; 893 cmsg->cmsg_type = SCTP_SNDRCV; 894 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo)); 895 sinfo = CMSG_DATA(cmsg); 896 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo)); 897 sinfo->sinfo_ppid = cpu_to_le32(dlm_our_nodeid()); 898 outmessage.msg_controllen = cmsg->cmsg_len; 899 900 ret = kernel_sendmsg(base_con->sock, &outmessage, iov, 1, len); 901 if (ret < 0) { 902 log_print("Send first packet to node %d failed: %d", 903 con->nodeid, ret); 904 905 /* Try again later */ 906 clear_bit(CF_CONNECT_PENDING, &con->flags); 907 clear_bit(CF_INIT_PENDING, &con->flags); 908 } 909 else { 910 spin_lock(&con->writequeue_lock); 911 e->offset += ret; 912 e->len -= ret; 913 914 if (e->len == 0 && e->users == 0) { 915 list_del(&e->list); 916 free_entry(e); 917 } 918 spin_unlock(&con->writequeue_lock); 919 } 920} 921 922/* Connect a new socket to its peer */ 923static void tcp_connect_to_sock(struct connection *con) 924{ 925 int result = -EHOSTUNREACH; 926 struct sockaddr_storage saddr, src_addr; 927 int addr_len; 928 struct socket *sock = NULL; 929 930 if (con->nodeid == 0) { 931 log_print("attempt to connect sock 0 foiled"); 932 return; 933 } 934 935 mutex_lock(&con->sock_mutex); 936 if (con->retries++ > MAX_CONNECT_RETRIES) 937 goto out; 938 939 /* Some odd races can cause double-connects, ignore them */ 940 if (con->sock) { 941 result = 0; 942 goto out; 943 } 944 945 /* Create a socket to communicate with */ 946 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 947 IPPROTO_TCP, &sock); 948 if (result < 0) 949 goto out_err; 950 951 memset(&saddr, 0, sizeof(saddr)); 952 if (dlm_nodeid_to_addr(con->nodeid, &saddr)) 953 goto out_err; 954 955 sock->sk->sk_user_data = con; 956 con->rx_action = receive_from_sock; 957 con->connect_action = tcp_connect_to_sock; 958 add_sock(sock, con); 959 960 /* Bind to our cluster-known address connecting to avoid 961 routing problems */ 962 memcpy(&src_addr, dlm_local_addr[0], sizeof(src_addr)); 963 make_sockaddr(&src_addr, 0, &addr_len); 964 result = sock->ops->bind(sock, (struct sockaddr *) &src_addr, 965 addr_len); 966 if (result < 0) { 967 log_print("could not bind for connect: %d", result); 968 /* This *may* not indicate a critical error */ 969 } 970 971 make_sockaddr(&saddr, dlm_config.ci_tcp_port, &addr_len); 972 973 log_print("connecting to %d", con->nodeid); 974 result = 975 sock->ops->connect(sock, (struct sockaddr *)&saddr, addr_len, 976 O_NONBLOCK); 977 if (result == -EINPROGRESS) 978 result = 0; 979 if (result == 0) 980 goto out; 981 982out_err: 983 if (con->sock) { 984 sock_release(con->sock); 985 con->sock = NULL; 986 } else if (sock) { 987 sock_release(sock); 988 } 989 /* 990 * Some errors are fatal and this list might need adjusting. For other 991 * errors we try again until the max number of retries is reached. 992 */ 993 if (result != -EHOSTUNREACH && result != -ENETUNREACH && 994 result != -ENETDOWN && result != -EINVAL 995 && result != -EPROTONOSUPPORT) { 996 lowcomms_connect_sock(con); 997 result = 0; 998 } 999out: 1000 mutex_unlock(&con->sock_mutex); 1001 return; 1002} 1003 1004static struct socket *tcp_create_listen_sock(struct connection *con, 1005 struct sockaddr_storage *saddr) 1006{ 1007 struct socket *sock = NULL; 1008 int result = 0; 1009 int one = 1; 1010 int addr_len; 1011 1012 if (dlm_local_addr[0]->ss_family == AF_INET) 1013 addr_len = sizeof(struct sockaddr_in); 1014 else 1015 addr_len = sizeof(struct sockaddr_in6); 1016 1017 /* Create a socket to communicate with */ 1018 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 1019 IPPROTO_TCP, &sock); 1020 if (result < 0) { 1021 log_print("Can't create listening comms socket"); 1022 goto create_out; 1023 } 1024 1025 result = kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, 1026 (char *)&one, sizeof(one)); 1027 1028 if (result < 0) { 1029 log_print("Failed to set SO_REUSEADDR on socket: %d", result); 1030 } 1031 sock->sk->sk_user_data = con; 1032 con->rx_action = tcp_accept_from_sock; 1033 con->connect_action = tcp_connect_to_sock; 1034 con->sock = sock; 1035 1036 /* Bind to our port */ 1037 make_sockaddr(saddr, dlm_config.ci_tcp_port, &addr_len); 1038 result = sock->ops->bind(sock, (struct sockaddr *) saddr, addr_len); 1039 if (result < 0) { 1040 log_print("Can't bind to port %d", dlm_config.ci_tcp_port); 1041 sock_release(sock); 1042 sock = NULL; 1043 con->sock = NULL; 1044 goto create_out; 1045 } 1046 result = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, 1047 (char *)&one, sizeof(one)); 1048 if (result < 0) { 1049 log_print("Set keepalive failed: %d", result); 1050 } 1051 1052 result = sock->ops->listen(sock, 5); 1053 if (result < 0) { 1054 log_print("Can't listen on port %d", dlm_config.ci_tcp_port); 1055 sock_release(sock); 1056 sock = NULL; 1057 goto create_out; 1058 } 1059 1060create_out: 1061 return sock; 1062} 1063 1064/* Get local addresses */ 1065static void init_local(void) 1066{ 1067 struct sockaddr_storage sas, *addr; 1068 int i; 1069 1070 dlm_local_count = 0; 1071 for (i = 0; i < DLM_MAX_ADDR_COUNT - 1; i++) { 1072 if (dlm_our_addr(&sas, i)) 1073 break; 1074 1075 addr = kmalloc(sizeof(*addr), GFP_NOFS); 1076 if (!addr) 1077 break; 1078 memcpy(addr, &sas, sizeof(*addr)); 1079 dlm_local_addr[dlm_local_count++] = addr; 1080 } 1081} 1082 1083/* Bind to an IP address. SCTP allows multiple address so it can do 1084 multi-homing */ 1085static int add_sctp_bind_addr(struct connection *sctp_con, 1086 struct sockaddr_storage *addr, 1087 int addr_len, int num) 1088{ 1089 int result = 0; 1090 1091 if (num == 1) 1092 result = kernel_bind(sctp_con->sock, 1093 (struct sockaddr *) addr, 1094 addr_len); 1095 else 1096 result = kernel_setsockopt(sctp_con->sock, SOL_SCTP, 1097 SCTP_SOCKOPT_BINDX_ADD, 1098 (char *)addr, addr_len); 1099 1100 if (result < 0) 1101 log_print("Can't bind to port %d addr number %d", 1102 dlm_config.ci_tcp_port, num); 1103 1104 return result; 1105} 1106 1107/* Initialise SCTP socket and bind to all interfaces */ 1108static int sctp_listen_for_all(void) 1109{ 1110 struct socket *sock = NULL; 1111 struct sockaddr_storage localaddr; 1112 struct sctp_event_subscribe subscribe; 1113 int result = -EINVAL, num = 1, i, addr_len; 1114 struct connection *con = nodeid2con(0, GFP_NOFS); 1115 int bufsize = NEEDED_RMEM; 1116 1117 if (!con) 1118 return -ENOMEM; 1119 1120 log_print("Using SCTP for communications"); 1121 1122 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_SEQPACKET, 1123 IPPROTO_SCTP, &sock); 1124 if (result < 0) { 1125 log_print("Can't create comms socket, check SCTP is loaded"); 1126 goto out; 1127 } 1128 1129 /* Listen for events */ 1130 memset(&subscribe, 0, sizeof(subscribe)); 1131 subscribe.sctp_data_io_event = 1; 1132 subscribe.sctp_association_event = 1; 1133 subscribe.sctp_send_failure_event = 1; 1134 subscribe.sctp_shutdown_event = 1; 1135 subscribe.sctp_partial_delivery_event = 1; 1136 1137 result = kernel_setsockopt(sock, SOL_SOCKET, SO_RCVBUFFORCE, 1138 (char *)&bufsize, sizeof(bufsize)); 1139 if (result) 1140 log_print("Error increasing buffer space on socket %d", result); 1141 1142 result = kernel_setsockopt(sock, SOL_SCTP, SCTP_EVENTS, 1143 (char *)&subscribe, sizeof(subscribe)); 1144 if (result < 0) { 1145 log_print("Failed to set SCTP_EVENTS on socket: result=%d", 1146 result); 1147 goto create_delsock; 1148 } 1149 1150 /* Init con struct */ 1151 sock->sk->sk_user_data = con; 1152 con->sock = sock; 1153 con->sock->sk->sk_data_ready = lowcomms_data_ready; 1154 con->rx_action = receive_from_sock; 1155 con->connect_action = sctp_init_assoc; 1156 1157 /* Bind to all interfaces. */ 1158 for (i = 0; i < dlm_local_count; i++) { 1159 memcpy(&localaddr, dlm_local_addr[i], sizeof(localaddr)); 1160 make_sockaddr(&localaddr, dlm_config.ci_tcp_port, &addr_len); 1161 1162 result = add_sctp_bind_addr(con, &localaddr, addr_len, num); 1163 if (result) 1164 goto create_delsock; 1165 ++num; 1166 } 1167 1168 result = sock->ops->listen(sock, 5); 1169 if (result < 0) { 1170 log_print("Can't set socket listening"); 1171 goto create_delsock; 1172 } 1173 1174 return 0; 1175 1176create_delsock: 1177 sock_release(sock); 1178 con->sock = NULL; 1179out: 1180 return result; 1181} 1182 1183static int tcp_listen_for_all(void) 1184{ 1185 struct socket *sock = NULL; 1186 struct connection *con = nodeid2con(0, GFP_NOFS); 1187 int result = -EINVAL; 1188 1189 if (!con) 1190 return -ENOMEM; 1191 1192 /* We don't support multi-homed hosts */ 1193 if (dlm_local_addr[1] != NULL) { 1194 log_print("TCP protocol can't handle multi-homed hosts, " 1195 "try SCTP"); 1196 return -EINVAL; 1197 } 1198 1199 log_print("Using TCP for communications"); 1200 1201 sock = tcp_create_listen_sock(con, dlm_local_addr[0]); 1202 if (sock) { 1203 add_sock(sock, con); 1204 result = 0; 1205 } 1206 else { 1207 result = -EADDRINUSE; 1208 } 1209 1210 return result; 1211} 1212 1213 1214 1215static struct writequeue_entry *new_writequeue_entry(struct connection *con, 1216 gfp_t allocation) 1217{ 1218 struct writequeue_entry *entry; 1219 1220 entry = kmalloc(sizeof(struct writequeue_entry), allocation); 1221 if (!entry) 1222 return NULL; 1223 1224 entry->page = alloc_page(allocation); 1225 if (!entry->page) { 1226 kfree(entry); 1227 return NULL; 1228 } 1229 1230 entry->offset = 0; 1231 entry->len = 0; 1232 entry->end = 0; 1233 entry->users = 0; 1234 entry->con = con; 1235 1236 return entry; 1237} 1238 1239void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc) 1240{ 1241 struct connection *con; 1242 struct writequeue_entry *e; 1243 int offset = 0; 1244 int users = 0; 1245 1246 con = nodeid2con(nodeid, allocation); 1247 if (!con) 1248 return NULL; 1249 1250 spin_lock(&con->writequeue_lock); 1251 e = list_entry(con->writequeue.prev, struct writequeue_entry, list); 1252 if ((&e->list == &con->writequeue) || 1253 (PAGE_CACHE_SIZE - e->end < len)) { 1254 e = NULL; 1255 } else { 1256 offset = e->end; 1257 e->end += len; 1258 users = e->users++; 1259 } 1260 spin_unlock(&con->writequeue_lock); 1261 1262 if (e) { 1263 got_one: 1264 *ppc = page_address(e->page) + offset; 1265 return e; 1266 } 1267 1268 e = new_writequeue_entry(con, allocation); 1269 if (e) { 1270 spin_lock(&con->writequeue_lock); 1271 offset = e->end; 1272 e->end += len; 1273 users = e->users++; 1274 list_add_tail(&e->list, &con->writequeue); 1275 spin_unlock(&con->writequeue_lock); 1276 goto got_one; 1277 } 1278 return NULL; 1279} 1280 1281void dlm_lowcomms_commit_buffer(void *mh) 1282{ 1283 struct writequeue_entry *e = (struct writequeue_entry *)mh; 1284 struct connection *con = e->con; 1285 int users; 1286 1287 spin_lock(&con->writequeue_lock); 1288 users = --e->users; 1289 if (users) 1290 goto out; 1291 e->len = e->end - e->offset; 1292 spin_unlock(&con->writequeue_lock); 1293 1294 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) { 1295 queue_work(send_workqueue, &con->swork); 1296 } 1297 return; 1298 1299out: 1300 spin_unlock(&con->writequeue_lock); 1301 return; 1302} 1303 1304/* Send a message */ 1305static void send_to_sock(struct connection *con) 1306{ 1307 int ret = 0; 1308 const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL; 1309 struct writequeue_entry *e; 1310 int len, offset; 1311 1312 mutex_lock(&con->sock_mutex); 1313 if (con->sock == NULL) 1314 goto out_connect; 1315 1316 spin_lock(&con->writequeue_lock); 1317 for (;;) { 1318 e = list_entry(con->writequeue.next, struct writequeue_entry, 1319 list); 1320 if ((struct list_head *) e == &con->writequeue) 1321 break; 1322 1323 len = e->len; 1324 offset = e->offset; 1325 BUG_ON(len == 0 && e->users == 0); 1326 spin_unlock(&con->writequeue_lock); 1327 1328 ret = 0; 1329 if (len) { 1330 ret = kernel_sendpage(con->sock, e->page, offset, len, 1331 msg_flags); 1332 if (ret == -EAGAIN || ret == 0) { 1333 if (ret == -EAGAIN && 1334 test_bit(SOCK_ASYNC_NOSPACE, &con->sock->flags) && 1335 !test_and_set_bit(CF_APP_LIMITED, &con->flags)) { 1336 /* Notify TCP that we're limited by the 1337 * application window size. 1338 */ 1339 set_bit(SOCK_NOSPACE, &con->sock->flags); 1340 con->sock->sk->sk_write_pending++; 1341 } 1342 cond_resched(); 1343 goto out; 1344 } 1345 if (ret <= 0) 1346 goto send_error; 1347 } 1348 /* Don't starve people filling buffers */ 1349 cond_resched(); 1350 1351 spin_lock(&con->writequeue_lock); 1352 e->offset += ret; 1353 e->len -= ret; 1354 1355 if (e->len == 0 && e->users == 0) { 1356 list_del(&e->list); 1357 free_entry(e); 1358 continue; 1359 } 1360 } 1361 spin_unlock(&con->writequeue_lock); 1362out: 1363 mutex_unlock(&con->sock_mutex); 1364 return; 1365 1366send_error: 1367 mutex_unlock(&con->sock_mutex); 1368 close_connection(con, false); 1369 lowcomms_connect_sock(con); 1370 return; 1371 1372out_connect: 1373 mutex_unlock(&con->sock_mutex); 1374 if (!test_bit(CF_INIT_PENDING, &con->flags)) 1375 lowcomms_connect_sock(con); 1376 return; 1377} 1378 1379static void clean_one_writequeue(struct connection *con) 1380{ 1381 struct writequeue_entry *e, *safe; 1382 1383 spin_lock(&con->writequeue_lock); 1384 list_for_each_entry_safe(e, safe, &con->writequeue, list) { 1385 list_del(&e->list); 1386 free_entry(e); 1387 } 1388 spin_unlock(&con->writequeue_lock); 1389} 1390 1391/* Called from recovery when it knows that a node has 1392 left the cluster */ 1393int dlm_lowcomms_close(int nodeid) 1394{ 1395 struct connection *con; 1396 1397 log_print("closing connection to node %d", nodeid); 1398 con = nodeid2con(nodeid, 0); 1399 if (con) { 1400 clear_bit(CF_CONNECT_PENDING, &con->flags); 1401 clear_bit(CF_WRITE_PENDING, &con->flags); 1402 set_bit(CF_CLOSE, &con->flags); 1403 if (cancel_work_sync(&con->swork)) 1404 log_print("canceled swork for node %d", nodeid); 1405 if (cancel_work_sync(&con->rwork)) 1406 log_print("canceled rwork for node %d", nodeid); 1407 clean_one_writequeue(con); 1408 close_connection(con, true); 1409 } 1410 return 0; 1411} 1412 1413/* Receive workqueue function */ 1414static void process_recv_sockets(struct work_struct *work) 1415{ 1416 struct connection *con = container_of(work, struct connection, rwork); 1417 int err; 1418 1419 clear_bit(CF_READ_PENDING, &con->flags); 1420 do { 1421 err = con->rx_action(con); 1422 } while (!err); 1423} 1424 1425/* Send workqueue function */ 1426static void process_send_sockets(struct work_struct *work) 1427{ 1428 struct connection *con = container_of(work, struct connection, swork); 1429 1430 if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) { 1431 con->connect_action(con); 1432 set_bit(CF_WRITE_PENDING, &con->flags); 1433 } 1434 if (test_and_clear_bit(CF_WRITE_PENDING, &con->flags)) 1435 send_to_sock(con); 1436} 1437 1438 1439/* Discard all entries on the write queues */ 1440static void clean_writequeues(void) 1441{ 1442 foreach_conn(clean_one_writequeue); 1443} 1444 1445static void work_stop(void) 1446{ 1447 destroy_workqueue(recv_workqueue); 1448 destroy_workqueue(send_workqueue); 1449} 1450 1451static int work_start(void) 1452{ 1453 int error; 1454 recv_workqueue = create_workqueue("dlm_recv"); 1455 error = IS_ERR(recv_workqueue); 1456 if (error) { 1457 log_print("can't start dlm_recv %d", error); 1458 return error; 1459 } 1460 1461 send_workqueue = create_singlethread_workqueue("dlm_send"); 1462 error = IS_ERR(send_workqueue); 1463 if (error) { 1464 log_print("can't start dlm_send %d", error); 1465 destroy_workqueue(recv_workqueue); 1466 return error; 1467 } 1468 1469 return 0; 1470} 1471 1472static void stop_conn(struct connection *con) 1473{ 1474 con->flags |= 0x0F; 1475 if (con->sock && con->sock->sk) 1476 con->sock->sk->sk_user_data = NULL; 1477} 1478 1479static void free_conn(struct connection *con) 1480{ 1481 close_connection(con, true); 1482 if (con->othercon) 1483 kmem_cache_free(con_cache, con->othercon); 1484 hlist_del(&con->list); 1485 kmem_cache_free(con_cache, con); 1486} 1487 1488void dlm_lowcomms_stop(void) 1489{ 1490 /* Set all the flags to prevent any 1491 socket activity. 1492 */ 1493 mutex_lock(&connections_lock); 1494 foreach_conn(stop_conn); 1495 mutex_unlock(&connections_lock); 1496 1497 work_stop(); 1498 1499 mutex_lock(&connections_lock); 1500 clean_writequeues(); 1501 1502 foreach_conn(free_conn); 1503 1504 mutex_unlock(&connections_lock); 1505 kmem_cache_destroy(con_cache); 1506} 1507 1508int dlm_lowcomms_start(void) 1509{ 1510 int error = -EINVAL; 1511 struct connection *con; 1512 int i; 1513 1514 for (i = 0; i < CONN_HASH_SIZE; i++) 1515 INIT_HLIST_HEAD(&connection_hash[i]); 1516 1517 init_local(); 1518 if (!dlm_local_count) { 1519 error = -ENOTCONN; 1520 log_print("no local IP address has been set"); 1521 goto out; 1522 } 1523 1524 error = -ENOMEM; 1525 con_cache = kmem_cache_create("dlm_conn", sizeof(struct connection), 1526 __alignof__(struct connection), 0, 1527 NULL); 1528 if (!con_cache) 1529 goto out; 1530 1531 /* Start listening */ 1532 if (dlm_config.ci_protocol == 0) 1533 error = tcp_listen_for_all(); 1534 else 1535 error = sctp_listen_for_all(); 1536 if (error) 1537 goto fail_unlisten; 1538 1539 error = work_start(); 1540 if (error) 1541 goto fail_unlisten; 1542 1543 return 0; 1544 1545fail_unlisten: 1546 con = nodeid2con(0,0); 1547 if (con) { 1548 close_connection(con, false); 1549 kmem_cache_free(con_cache, con); 1550 } 1551 kmem_cache_destroy(con_cache); 1552 1553out: 1554 return error; 1555} 1556