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 66 /* Number of messages to send before rescheduling */ 67 #define MAX_SEND_MSG_COUNT 25 68 69 struct cbuf { 70 unsigned int base; 71 unsigned int len; 72 unsigned int mask; 73 }; 74 75 static void cbuf_add(struct cbuf *cb, int n) 76 { 77 cb->len += n; 78 } 79 80 static int cbuf_data(struct cbuf *cb) 81 { 82 return ((cb->base + cb->len) & cb->mask); 83 } 84 85 static void cbuf_init(struct cbuf *cb, int size) 86 { 87 cb->base = cb->len = 0; 88 cb->mask = size-1; 89 } 90 91 static void cbuf_eat(struct cbuf *cb, int n) 92 { 93 cb->len -= n; 94 cb->base += n; 95 cb->base &= cb->mask; 96 } 97 98 static bool cbuf_empty(struct cbuf *cb) 99 { 100 return cb->len == 0; 101 } 102 103 struct connection { 104 struct socket *sock; /* NULL if not connected */ 105 uint32_t nodeid; /* So we know who we are in the list */ 106 struct mutex sock_mutex; 107 unsigned long flags; 108 #define CF_READ_PENDING 1 109 #define CF_WRITE_PENDING 2 110 #define CF_CONNECT_PENDING 3 111 #define CF_INIT_PENDING 4 112 #define CF_IS_OTHERCON 5 113 #define CF_CLOSE 6 114 #define CF_APP_LIMITED 7 115 struct list_head writequeue; /* List of outgoing writequeue_entries */ 116 spinlock_t writequeue_lock; 117 int (*rx_action) (struct connection *); /* What to do when active */ 118 void (*connect_action) (struct connection *); /* What to do to connect */ 119 struct page *rx_page; 120 struct cbuf cb; 121 int retries; 122 #define MAX_CONNECT_RETRIES 3 123 int sctp_assoc; 124 struct hlist_node list; 125 struct connection *othercon; 126 struct work_struct rwork; /* Receive workqueue */ 127 struct work_struct swork; /* Send workqueue */ 128 }; 129 #define sock2con(x) ((struct connection *)(x)->sk_user_data) 130 131 /* An entry waiting to be sent */ 132 struct writequeue_entry { 133 struct list_head list; 134 struct page *page; 135 int offset; 136 int len; 137 int end; 138 int users; 139 struct connection *con; 140 }; 141 142 static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT]; 143 static int dlm_local_count; 144 145 /* Work queues */ 146 static struct workqueue_struct *recv_workqueue; 147 static struct workqueue_struct *send_workqueue; 148 149 static struct hlist_head connection_hash[CONN_HASH_SIZE]; 150 static DEFINE_MUTEX(connections_lock); 151 static struct kmem_cache *con_cache; 152 153 static void process_recv_sockets(struct work_struct *work); 154 static void process_send_sockets(struct work_struct *work); 155 156 157 /* This is deliberately very simple because most clusters have simple 158 sequential nodeids, so we should be able to go straight to a connection 159 struct in the array */ 160 static inline int nodeid_hash(int nodeid) 161 { 162 return nodeid & (CONN_HASH_SIZE-1); 163 } 164 165 static struct connection *__find_con(int nodeid) 166 { 167 int r; 168 struct hlist_node *h; 169 struct connection *con; 170 171 r = nodeid_hash(nodeid); 172 173 hlist_for_each_entry(con, h, &connection_hash[r], list) { 174 if (con->nodeid == nodeid) 175 return con; 176 } 177 return NULL; 178 } 179 180 /* 181 * If 'allocation' is zero then we don't attempt to create a new 182 * connection structure for this node. 183 */ 184 static struct connection *__nodeid2con(int nodeid, gfp_t alloc) 185 { 186 struct connection *con = NULL; 187 int r; 188 189 con = __find_con(nodeid); 190 if (con || !alloc) 191 return con; 192 193 con = kmem_cache_zalloc(con_cache, alloc); 194 if (!con) 195 return NULL; 196 197 r = nodeid_hash(nodeid); 198 hlist_add_head(&con->list, &connection_hash[r]); 199 200 con->nodeid = nodeid; 201 mutex_init(&con->sock_mutex); 202 INIT_LIST_HEAD(&con->writequeue); 203 spin_lock_init(&con->writequeue_lock); 204 INIT_WORK(&con->swork, process_send_sockets); 205 INIT_WORK(&con->rwork, process_recv_sockets); 206 207 /* Setup action pointers for child sockets */ 208 if (con->nodeid) { 209 struct connection *zerocon = __find_con(0); 210 211 con->connect_action = zerocon->connect_action; 212 if (!con->rx_action) 213 con->rx_action = zerocon->rx_action; 214 } 215 216 return con; 217 } 218 219 /* Loop round all connections */ 220 static void foreach_conn(void (*conn_func)(struct connection *c)) 221 { 222 int i; 223 struct hlist_node *h, *n; 224 struct connection *con; 225 226 for (i = 0; i < CONN_HASH_SIZE; i++) { 227 hlist_for_each_entry_safe(con, h, n, &connection_hash[i], list){ 228 conn_func(con); 229 } 230 } 231 } 232 233 static struct connection *nodeid2con(int nodeid, gfp_t allocation) 234 { 235 struct connection *con; 236 237 mutex_lock(&connections_lock); 238 con = __nodeid2con(nodeid, allocation); 239 mutex_unlock(&connections_lock); 240 241 return con; 242 } 243 244 /* This is a bit drastic, but only called when things go wrong */ 245 static struct connection *assoc2con(int assoc_id) 246 { 247 int i; 248 struct hlist_node *h; 249 struct connection *con; 250 251 mutex_lock(&connections_lock); 252 253 for (i = 0 ; i < CONN_HASH_SIZE; i++) { 254 hlist_for_each_entry(con, h, &connection_hash[i], list) { 255 if (con->sctp_assoc == assoc_id) { 256 mutex_unlock(&connections_lock); 257 return con; 258 } 259 } 260 } 261 mutex_unlock(&connections_lock); 262 return NULL; 263 } 264 265 static int nodeid_to_addr(int nodeid, struct sockaddr *retaddr) 266 { 267 struct sockaddr_storage addr; 268 int error; 269 270 if (!dlm_local_count) 271 return -1; 272 273 error = dlm_nodeid_to_addr(nodeid, &addr); 274 if (error) 275 return error; 276 277 if (dlm_local_addr[0]->ss_family == AF_INET) { 278 struct sockaddr_in *in4 = (struct sockaddr_in *) &addr; 279 struct sockaddr_in *ret4 = (struct sockaddr_in *) retaddr; 280 ret4->sin_addr.s_addr = in4->sin_addr.s_addr; 281 } else { 282 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) &addr; 283 struct sockaddr_in6 *ret6 = (struct sockaddr_in6 *) retaddr; 284 ipv6_addr_copy(&ret6->sin6_addr, &in6->sin6_addr); 285 } 286 287 return 0; 288 } 289 290 /* Data available on socket or listen socket received a connect */ 291 static void lowcomms_data_ready(struct sock *sk, int count_unused) 292 { 293 struct connection *con = sock2con(sk); 294 if (con && !test_and_set_bit(CF_READ_PENDING, &con->flags)) 295 queue_work(recv_workqueue, &con->rwork); 296 } 297 298 static void lowcomms_write_space(struct sock *sk) 299 { 300 struct connection *con = sock2con(sk); 301 302 if (!con) 303 return; 304 305 clear_bit(SOCK_NOSPACE, &con->sock->flags); 306 307 if (test_and_clear_bit(CF_APP_LIMITED, &con->flags)) { 308 con->sock->sk->sk_write_pending--; 309 clear_bit(SOCK_ASYNC_NOSPACE, &con->sock->flags); 310 } 311 312 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) 313 queue_work(send_workqueue, &con->swork); 314 } 315 316 static inline void lowcomms_connect_sock(struct connection *con) 317 { 318 if (test_bit(CF_CLOSE, &con->flags)) 319 return; 320 if (!test_and_set_bit(CF_CONNECT_PENDING, &con->flags)) 321 queue_work(send_workqueue, &con->swork); 322 } 323 324 static void lowcomms_state_change(struct sock *sk) 325 { 326 if (sk->sk_state == TCP_ESTABLISHED) 327 lowcomms_write_space(sk); 328 } 329 330 int dlm_lowcomms_connect_node(int nodeid) 331 { 332 struct connection *con; 333 334 /* with sctp there's no connecting without sending */ 335 if (dlm_config.ci_protocol != 0) 336 return 0; 337 338 if (nodeid == dlm_our_nodeid()) 339 return 0; 340 341 con = nodeid2con(nodeid, GFP_NOFS); 342 if (!con) 343 return -ENOMEM; 344 lowcomms_connect_sock(con); 345 return 0; 346 } 347 348 /* Make a socket active */ 349 static int add_sock(struct socket *sock, struct connection *con) 350 { 351 con->sock = sock; 352 353 /* Install a data_ready callback */ 354 con->sock->sk->sk_data_ready = lowcomms_data_ready; 355 con->sock->sk->sk_write_space = lowcomms_write_space; 356 con->sock->sk->sk_state_change = lowcomms_state_change; 357 con->sock->sk->sk_user_data = con; 358 con->sock->sk->sk_allocation = GFP_NOFS; 359 return 0; 360 } 361 362 /* Add the port number to an IPv6 or 4 sockaddr and return the address 363 length */ 364 static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port, 365 int *addr_len) 366 { 367 saddr->ss_family = dlm_local_addr[0]->ss_family; 368 if (saddr->ss_family == AF_INET) { 369 struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr; 370 in4_addr->sin_port = cpu_to_be16(port); 371 *addr_len = sizeof(struct sockaddr_in); 372 memset(&in4_addr->sin_zero, 0, sizeof(in4_addr->sin_zero)); 373 } else { 374 struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr; 375 in6_addr->sin6_port = cpu_to_be16(port); 376 *addr_len = sizeof(struct sockaddr_in6); 377 } 378 memset((char *)saddr + *addr_len, 0, sizeof(struct sockaddr_storage) - *addr_len); 379 } 380 381 /* Close a remote connection and tidy up */ 382 static void close_connection(struct connection *con, bool and_other) 383 { 384 mutex_lock(&con->sock_mutex); 385 386 if (con->sock) { 387 sock_release(con->sock); 388 con->sock = NULL; 389 } 390 if (con->othercon && and_other) { 391 /* Will only re-enter once. */ 392 close_connection(con->othercon, false); 393 } 394 if (con->rx_page) { 395 __free_page(con->rx_page); 396 con->rx_page = NULL; 397 } 398 399 con->retries = 0; 400 mutex_unlock(&con->sock_mutex); 401 } 402 403 /* We only send shutdown messages to nodes that are not part of the cluster */ 404 static void sctp_send_shutdown(sctp_assoc_t associd) 405 { 406 static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 407 struct msghdr outmessage; 408 struct cmsghdr *cmsg; 409 struct sctp_sndrcvinfo *sinfo; 410 int ret; 411 struct connection *con; 412 413 con = nodeid2con(0,0); 414 BUG_ON(con == NULL); 415 416 outmessage.msg_name = NULL; 417 outmessage.msg_namelen = 0; 418 outmessage.msg_control = outcmsg; 419 outmessage.msg_controllen = sizeof(outcmsg); 420 outmessage.msg_flags = MSG_EOR; 421 422 cmsg = CMSG_FIRSTHDR(&outmessage); 423 cmsg->cmsg_level = IPPROTO_SCTP; 424 cmsg->cmsg_type = SCTP_SNDRCV; 425 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo)); 426 outmessage.msg_controllen = cmsg->cmsg_len; 427 sinfo = CMSG_DATA(cmsg); 428 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo)); 429 430 sinfo->sinfo_flags |= MSG_EOF; 431 sinfo->sinfo_assoc_id = associd; 432 433 ret = kernel_sendmsg(con->sock, &outmessage, NULL, 0, 0); 434 435 if (ret != 0) 436 log_print("send EOF to node failed: %d", ret); 437 } 438 439 static void sctp_init_failed_foreach(struct connection *con) 440 { 441 con->sctp_assoc = 0; 442 if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) { 443 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) 444 queue_work(send_workqueue, &con->swork); 445 } 446 } 447 448 /* INIT failed but we don't know which node... 449 restart INIT on all pending nodes */ 450 static void sctp_init_failed(void) 451 { 452 mutex_lock(&connections_lock); 453 454 foreach_conn(sctp_init_failed_foreach); 455 456 mutex_unlock(&connections_lock); 457 } 458 459 /* Something happened to an association */ 460 static void process_sctp_notification(struct connection *con, 461 struct msghdr *msg, char *buf) 462 { 463 union sctp_notification *sn = (union sctp_notification *)buf; 464 465 if (sn->sn_header.sn_type == SCTP_ASSOC_CHANGE) { 466 switch (sn->sn_assoc_change.sac_state) { 467 468 case SCTP_COMM_UP: 469 case SCTP_RESTART: 470 { 471 /* Check that the new node is in the lockspace */ 472 struct sctp_prim prim; 473 int nodeid; 474 int prim_len, ret; 475 int addr_len; 476 struct connection *new_con; 477 sctp_peeloff_arg_t parg; 478 int parglen = sizeof(parg); 479 int err; 480 481 /* 482 * We get this before any data for an association. 483 * We verify that the node is in the cluster and 484 * then peel off a socket for it. 485 */ 486 if ((int)sn->sn_assoc_change.sac_assoc_id <= 0) { 487 log_print("COMM_UP for invalid assoc ID %d", 488 (int)sn->sn_assoc_change.sac_assoc_id); 489 sctp_init_failed(); 490 return; 491 } 492 memset(&prim, 0, sizeof(struct sctp_prim)); 493 prim_len = sizeof(struct sctp_prim); 494 prim.ssp_assoc_id = sn->sn_assoc_change.sac_assoc_id; 495 496 ret = kernel_getsockopt(con->sock, 497 IPPROTO_SCTP, 498 SCTP_PRIMARY_ADDR, 499 (char*)&prim, 500 &prim_len); 501 if (ret < 0) { 502 log_print("getsockopt/sctp_primary_addr on " 503 "new assoc %d failed : %d", 504 (int)sn->sn_assoc_change.sac_assoc_id, 505 ret); 506 507 /* Retry INIT later */ 508 new_con = assoc2con(sn->sn_assoc_change.sac_assoc_id); 509 if (new_con) 510 clear_bit(CF_CONNECT_PENDING, &con->flags); 511 return; 512 } 513 make_sockaddr(&prim.ssp_addr, 0, &addr_len); 514 if (dlm_addr_to_nodeid(&prim.ssp_addr, &nodeid)) { 515 int i; 516 unsigned char *b=(unsigned char *)&prim.ssp_addr; 517 log_print("reject connect from unknown addr"); 518 for (i=0; i<sizeof(struct sockaddr_storage);i++) 519 printk("%02x ", b[i]); 520 printk("\n"); 521 sctp_send_shutdown(prim.ssp_assoc_id); 522 return; 523 } 524 525 new_con = nodeid2con(nodeid, GFP_NOFS); 526 if (!new_con) 527 return; 528 529 /* Peel off a new sock */ 530 parg.associd = sn->sn_assoc_change.sac_assoc_id; 531 ret = kernel_getsockopt(con->sock, IPPROTO_SCTP, 532 SCTP_SOCKOPT_PEELOFF, 533 (void *)&parg, &parglen); 534 if (ret < 0) { 535 log_print("Can't peel off a socket for " 536 "connection %d to node %d: err=%d", 537 parg.associd, nodeid, ret); 538 return; 539 } 540 new_con->sock = sockfd_lookup(parg.sd, &err); 541 if (!new_con->sock) { 542 log_print("sockfd_lookup error %d", err); 543 return; 544 } 545 add_sock(new_con->sock, new_con); 546 sockfd_put(new_con->sock); 547 548 log_print("connecting to %d sctp association %d", 549 nodeid, (int)sn->sn_assoc_change.sac_assoc_id); 550 551 /* Send any pending writes */ 552 clear_bit(CF_CONNECT_PENDING, &new_con->flags); 553 clear_bit(CF_INIT_PENDING, &con->flags); 554 if (!test_and_set_bit(CF_WRITE_PENDING, &new_con->flags)) { 555 queue_work(send_workqueue, &new_con->swork); 556 } 557 if (!test_and_set_bit(CF_READ_PENDING, &new_con->flags)) 558 queue_work(recv_workqueue, &new_con->rwork); 559 } 560 break; 561 562 case SCTP_COMM_LOST: 563 case SCTP_SHUTDOWN_COMP: 564 { 565 con = assoc2con(sn->sn_assoc_change.sac_assoc_id); 566 if (con) { 567 con->sctp_assoc = 0; 568 } 569 } 570 break; 571 572 /* We don't know which INIT failed, so clear the PENDING flags 573 * on them all. if assoc_id is zero then it will then try 574 * again */ 575 576 case SCTP_CANT_STR_ASSOC: 577 { 578 log_print("Can't start SCTP association - retrying"); 579 sctp_init_failed(); 580 } 581 break; 582 583 default: 584 log_print("unexpected SCTP assoc change id=%d state=%d", 585 (int)sn->sn_assoc_change.sac_assoc_id, 586 sn->sn_assoc_change.sac_state); 587 } 588 } 589 } 590 591 /* Data received from remote end */ 592 static int receive_from_sock(struct connection *con) 593 { 594 int ret = 0; 595 struct msghdr msg = {}; 596 struct kvec iov[2]; 597 unsigned len; 598 int r; 599 int call_again_soon = 0; 600 int nvec; 601 char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 602 603 mutex_lock(&con->sock_mutex); 604 605 if (con->sock == NULL) { 606 ret = -EAGAIN; 607 goto out_close; 608 } 609 610 if (con->rx_page == NULL) { 611 /* 612 * This doesn't need to be atomic, but I think it should 613 * improve performance if it is. 614 */ 615 con->rx_page = alloc_page(GFP_ATOMIC); 616 if (con->rx_page == NULL) 617 goto out_resched; 618 cbuf_init(&con->cb, PAGE_CACHE_SIZE); 619 } 620 621 /* Only SCTP needs these really */ 622 memset(&incmsg, 0, sizeof(incmsg)); 623 msg.msg_control = incmsg; 624 msg.msg_controllen = sizeof(incmsg); 625 626 /* 627 * iov[0] is the bit of the circular buffer between the current end 628 * point (cb.base + cb.len) and the end of the buffer. 629 */ 630 iov[0].iov_len = con->cb.base - cbuf_data(&con->cb); 631 iov[0].iov_base = page_address(con->rx_page) + cbuf_data(&con->cb); 632 iov[1].iov_len = 0; 633 nvec = 1; 634 635 /* 636 * iov[1] is the bit of the circular buffer between the start of the 637 * buffer and the start of the currently used section (cb.base) 638 */ 639 if (cbuf_data(&con->cb) >= con->cb.base) { 640 iov[0].iov_len = PAGE_CACHE_SIZE - cbuf_data(&con->cb); 641 iov[1].iov_len = con->cb.base; 642 iov[1].iov_base = page_address(con->rx_page); 643 nvec = 2; 644 } 645 len = iov[0].iov_len + iov[1].iov_len; 646 647 r = ret = kernel_recvmsg(con->sock, &msg, iov, nvec, len, 648 MSG_DONTWAIT | MSG_NOSIGNAL); 649 if (ret <= 0) 650 goto out_close; 651 652 /* Process SCTP notifications */ 653 if (msg.msg_flags & MSG_NOTIFICATION) { 654 msg.msg_control = incmsg; 655 msg.msg_controllen = sizeof(incmsg); 656 657 process_sctp_notification(con, &msg, 658 page_address(con->rx_page) + con->cb.base); 659 mutex_unlock(&con->sock_mutex); 660 return 0; 661 } 662 BUG_ON(con->nodeid == 0); 663 664 if (ret == len) 665 call_again_soon = 1; 666 cbuf_add(&con->cb, ret); 667 ret = dlm_process_incoming_buffer(con->nodeid, 668 page_address(con->rx_page), 669 con->cb.base, con->cb.len, 670 PAGE_CACHE_SIZE); 671 if (ret == -EBADMSG) { 672 log_print("lowcomms: addr=%p, base=%u, len=%u, " 673 "iov_len=%u, iov_base[0]=%p, read=%d", 674 page_address(con->rx_page), con->cb.base, con->cb.len, 675 len, iov[0].iov_base, r); 676 } 677 if (ret < 0) 678 goto out_close; 679 cbuf_eat(&con->cb, ret); 680 681 if (cbuf_empty(&con->cb) && !call_again_soon) { 682 __free_page(con->rx_page); 683 con->rx_page = NULL; 684 } 685 686 if (call_again_soon) 687 goto out_resched; 688 mutex_unlock(&con->sock_mutex); 689 return 0; 690 691 out_resched: 692 if (!test_and_set_bit(CF_READ_PENDING, &con->flags)) 693 queue_work(recv_workqueue, &con->rwork); 694 mutex_unlock(&con->sock_mutex); 695 return -EAGAIN; 696 697 out_close: 698 mutex_unlock(&con->sock_mutex); 699 if (ret != -EAGAIN) { 700 close_connection(con, false); 701 /* Reconnect when there is something to send */ 702 } 703 /* Don't return success if we really got EOF */ 704 if (ret == 0) 705 ret = -EAGAIN; 706 707 return ret; 708 } 709 710 /* Listening socket is busy, accept a connection */ 711 static int tcp_accept_from_sock(struct connection *con) 712 { 713 int result; 714 struct sockaddr_storage peeraddr; 715 struct socket *newsock; 716 int len; 717 int nodeid; 718 struct connection *newcon; 719 struct connection *addcon; 720 721 memset(&peeraddr, 0, sizeof(peeraddr)); 722 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 723 IPPROTO_TCP, &newsock); 724 if (result < 0) 725 return -ENOMEM; 726 727 mutex_lock_nested(&con->sock_mutex, 0); 728 729 result = -ENOTCONN; 730 if (con->sock == NULL) 731 goto accept_err; 732 733 newsock->type = con->sock->type; 734 newsock->ops = con->sock->ops; 735 736 result = con->sock->ops->accept(con->sock, newsock, O_NONBLOCK); 737 if (result < 0) 738 goto accept_err; 739 740 /* Get the connected socket's peer */ 741 memset(&peeraddr, 0, sizeof(peeraddr)); 742 if (newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr, 743 &len, 2)) { 744 result = -ECONNABORTED; 745 goto accept_err; 746 } 747 748 /* Get the new node's NODEID */ 749 make_sockaddr(&peeraddr, 0, &len); 750 if (dlm_addr_to_nodeid(&peeraddr, &nodeid)) { 751 log_print("connect from non cluster node"); 752 sock_release(newsock); 753 mutex_unlock(&con->sock_mutex); 754 return -1; 755 } 756 757 log_print("got connection from %d", nodeid); 758 759 /* Check to see if we already have a connection to this node. This 760 * could happen if the two nodes initiate a connection at roughly 761 * the same time and the connections cross on the wire. 762 * In this case we store the incoming one in "othercon" 763 */ 764 newcon = nodeid2con(nodeid, GFP_NOFS); 765 if (!newcon) { 766 result = -ENOMEM; 767 goto accept_err; 768 } 769 mutex_lock_nested(&newcon->sock_mutex, 1); 770 if (newcon->sock) { 771 struct connection *othercon = newcon->othercon; 772 773 if (!othercon) { 774 othercon = kmem_cache_zalloc(con_cache, GFP_NOFS); 775 if (!othercon) { 776 log_print("failed to allocate incoming socket"); 777 mutex_unlock(&newcon->sock_mutex); 778 result = -ENOMEM; 779 goto accept_err; 780 } 781 othercon->nodeid = nodeid; 782 othercon->rx_action = receive_from_sock; 783 mutex_init(&othercon->sock_mutex); 784 INIT_WORK(&othercon->swork, process_send_sockets); 785 INIT_WORK(&othercon->rwork, process_recv_sockets); 786 set_bit(CF_IS_OTHERCON, &othercon->flags); 787 } 788 if (!othercon->sock) { 789 newcon->othercon = othercon; 790 othercon->sock = newsock; 791 newsock->sk->sk_user_data = othercon; 792 add_sock(newsock, othercon); 793 addcon = othercon; 794 } 795 else { 796 printk("Extra connection from node %d attempted\n", nodeid); 797 result = -EAGAIN; 798 mutex_unlock(&newcon->sock_mutex); 799 goto accept_err; 800 } 801 } 802 else { 803 newsock->sk->sk_user_data = newcon; 804 newcon->rx_action = receive_from_sock; 805 add_sock(newsock, newcon); 806 addcon = newcon; 807 } 808 809 mutex_unlock(&newcon->sock_mutex); 810 811 /* 812 * Add it to the active queue in case we got data 813 * beween processing the accept adding the socket 814 * to the read_sockets list 815 */ 816 if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags)) 817 queue_work(recv_workqueue, &addcon->rwork); 818 mutex_unlock(&con->sock_mutex); 819 820 return 0; 821 822 accept_err: 823 mutex_unlock(&con->sock_mutex); 824 sock_release(newsock); 825 826 if (result != -EAGAIN) 827 log_print("error accepting connection from node: %d", result); 828 return result; 829 } 830 831 static void free_entry(struct writequeue_entry *e) 832 { 833 __free_page(e->page); 834 kfree(e); 835 } 836 837 /* Initiate an SCTP association. 838 This is a special case of send_to_sock() in that we don't yet have a 839 peeled-off socket for this association, so we use the listening socket 840 and add the primary IP address of the remote node. 841 */ 842 static void sctp_init_assoc(struct connection *con) 843 { 844 struct sockaddr_storage rem_addr; 845 char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 846 struct msghdr outmessage; 847 struct cmsghdr *cmsg; 848 struct sctp_sndrcvinfo *sinfo; 849 struct connection *base_con; 850 struct writequeue_entry *e; 851 int len, offset; 852 int ret; 853 int addrlen; 854 struct kvec iov[1]; 855 856 if (test_and_set_bit(CF_INIT_PENDING, &con->flags)) 857 return; 858 859 if (con->retries++ > MAX_CONNECT_RETRIES) 860 return; 861 862 if (nodeid_to_addr(con->nodeid, (struct sockaddr *)&rem_addr)) { 863 log_print("no address for nodeid %d", con->nodeid); 864 return; 865 } 866 base_con = nodeid2con(0, 0); 867 BUG_ON(base_con == NULL); 868 869 make_sockaddr(&rem_addr, dlm_config.ci_tcp_port, &addrlen); 870 871 outmessage.msg_name = &rem_addr; 872 outmessage.msg_namelen = addrlen; 873 outmessage.msg_control = outcmsg; 874 outmessage.msg_controllen = sizeof(outcmsg); 875 outmessage.msg_flags = MSG_EOR; 876 877 spin_lock(&con->writequeue_lock); 878 879 if (list_empty(&con->writequeue)) { 880 spin_unlock(&con->writequeue_lock); 881 log_print("writequeue empty for nodeid %d", con->nodeid); 882 return; 883 } 884 885 e = list_first_entry(&con->writequeue, struct writequeue_entry, list); 886 len = e->len; 887 offset = e->offset; 888 spin_unlock(&con->writequeue_lock); 889 890 /* Send the first block off the write queue */ 891 iov[0].iov_base = page_address(e->page)+offset; 892 iov[0].iov_len = len; 893 894 cmsg = CMSG_FIRSTHDR(&outmessage); 895 cmsg->cmsg_level = IPPROTO_SCTP; 896 cmsg->cmsg_type = SCTP_SNDRCV; 897 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo)); 898 sinfo = CMSG_DATA(cmsg); 899 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo)); 900 sinfo->sinfo_ppid = cpu_to_le32(dlm_our_nodeid()); 901 outmessage.msg_controllen = cmsg->cmsg_len; 902 903 ret = kernel_sendmsg(base_con->sock, &outmessage, iov, 1, len); 904 if (ret < 0) { 905 log_print("Send first packet to node %d failed: %d", 906 con->nodeid, ret); 907 908 /* Try again later */ 909 clear_bit(CF_CONNECT_PENDING, &con->flags); 910 clear_bit(CF_INIT_PENDING, &con->flags); 911 } 912 else { 913 spin_lock(&con->writequeue_lock); 914 e->offset += ret; 915 e->len -= ret; 916 917 if (e->len == 0 && e->users == 0) { 918 list_del(&e->list); 919 free_entry(e); 920 } 921 spin_unlock(&con->writequeue_lock); 922 } 923 } 924 925 /* Connect a new socket to its peer */ 926 static void tcp_connect_to_sock(struct connection *con) 927 { 928 int result = -EHOSTUNREACH; 929 struct sockaddr_storage saddr, src_addr; 930 int addr_len; 931 struct socket *sock = NULL; 932 int one = 1; 933 934 if (con->nodeid == 0) { 935 log_print("attempt to connect sock 0 foiled"); 936 return; 937 } 938 939 mutex_lock(&con->sock_mutex); 940 if (con->retries++ > MAX_CONNECT_RETRIES) 941 goto out; 942 943 /* Some odd races can cause double-connects, ignore them */ 944 if (con->sock) { 945 result = 0; 946 goto out; 947 } 948 949 /* Create a socket to communicate with */ 950 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 951 IPPROTO_TCP, &sock); 952 if (result < 0) 953 goto out_err; 954 955 memset(&saddr, 0, sizeof(saddr)); 956 if (dlm_nodeid_to_addr(con->nodeid, &saddr)) 957 goto out_err; 958 959 sock->sk->sk_user_data = con; 960 con->rx_action = receive_from_sock; 961 con->connect_action = tcp_connect_to_sock; 962 add_sock(sock, con); 963 964 /* Bind to our cluster-known address connecting to avoid 965 routing problems */ 966 memcpy(&src_addr, dlm_local_addr[0], sizeof(src_addr)); 967 make_sockaddr(&src_addr, 0, &addr_len); 968 result = sock->ops->bind(sock, (struct sockaddr *) &src_addr, 969 addr_len); 970 if (result < 0) { 971 log_print("could not bind for connect: %d", result); 972 /* This *may* not indicate a critical error */ 973 } 974 975 make_sockaddr(&saddr, dlm_config.ci_tcp_port, &addr_len); 976 977 log_print("connecting to %d", con->nodeid); 978 979 /* Turn off Nagle's algorithm */ 980 kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY, (char *)&one, 981 sizeof(one)); 982 983 result = 984 sock->ops->connect(sock, (struct sockaddr *)&saddr, addr_len, 985 O_NONBLOCK); 986 if (result == -EINPROGRESS) 987 result = 0; 988 if (result == 0) 989 goto out; 990 991 out_err: 992 if (con->sock) { 993 sock_release(con->sock); 994 con->sock = NULL; 995 } else if (sock) { 996 sock_release(sock); 997 } 998 /* 999 * Some errors are fatal and this list might need adjusting. For other 1000 * errors we try again until the max number of retries is reached. 1001 */ 1002 if (result != -EHOSTUNREACH && result != -ENETUNREACH && 1003 result != -ENETDOWN && result != -EINVAL 1004 && result != -EPROTONOSUPPORT) { 1005 lowcomms_connect_sock(con); 1006 result = 0; 1007 } 1008 out: 1009 mutex_unlock(&con->sock_mutex); 1010 return; 1011 } 1012 1013 static struct socket *tcp_create_listen_sock(struct connection *con, 1014 struct sockaddr_storage *saddr) 1015 { 1016 struct socket *sock = NULL; 1017 int result = 0; 1018 int one = 1; 1019 int addr_len; 1020 1021 if (dlm_local_addr[0]->ss_family == AF_INET) 1022 addr_len = sizeof(struct sockaddr_in); 1023 else 1024 addr_len = sizeof(struct sockaddr_in6); 1025 1026 /* Create a socket to communicate with */ 1027 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 1028 IPPROTO_TCP, &sock); 1029 if (result < 0) { 1030 log_print("Can't create listening comms socket"); 1031 goto create_out; 1032 } 1033 1034 /* Turn off Nagle's algorithm */ 1035 kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY, (char *)&one, 1036 sizeof(one)); 1037 1038 result = kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, 1039 (char *)&one, sizeof(one)); 1040 1041 if (result < 0) { 1042 log_print("Failed to set SO_REUSEADDR on socket: %d", result); 1043 } 1044 sock->sk->sk_user_data = con; 1045 con->rx_action = tcp_accept_from_sock; 1046 con->connect_action = tcp_connect_to_sock; 1047 con->sock = sock; 1048 1049 /* Bind to our port */ 1050 make_sockaddr(saddr, dlm_config.ci_tcp_port, &addr_len); 1051 result = sock->ops->bind(sock, (struct sockaddr *) saddr, addr_len); 1052 if (result < 0) { 1053 log_print("Can't bind to port %d", dlm_config.ci_tcp_port); 1054 sock_release(sock); 1055 sock = NULL; 1056 con->sock = NULL; 1057 goto create_out; 1058 } 1059 result = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, 1060 (char *)&one, sizeof(one)); 1061 if (result < 0) { 1062 log_print("Set keepalive failed: %d", result); 1063 } 1064 1065 result = sock->ops->listen(sock, 5); 1066 if (result < 0) { 1067 log_print("Can't listen on port %d", dlm_config.ci_tcp_port); 1068 sock_release(sock); 1069 sock = NULL; 1070 goto create_out; 1071 } 1072 1073 create_out: 1074 return sock; 1075 } 1076 1077 /* Get local addresses */ 1078 static void init_local(void) 1079 { 1080 struct sockaddr_storage sas, *addr; 1081 int i; 1082 1083 dlm_local_count = 0; 1084 for (i = 0; i < DLM_MAX_ADDR_COUNT - 1; i++) { 1085 if (dlm_our_addr(&sas, i)) 1086 break; 1087 1088 addr = kmalloc(sizeof(*addr), GFP_NOFS); 1089 if (!addr) 1090 break; 1091 memcpy(addr, &sas, sizeof(*addr)); 1092 dlm_local_addr[dlm_local_count++] = addr; 1093 } 1094 } 1095 1096 /* Bind to an IP address. SCTP allows multiple address so it can do 1097 multi-homing */ 1098 static int add_sctp_bind_addr(struct connection *sctp_con, 1099 struct sockaddr_storage *addr, 1100 int addr_len, int num) 1101 { 1102 int result = 0; 1103 1104 if (num == 1) 1105 result = kernel_bind(sctp_con->sock, 1106 (struct sockaddr *) addr, 1107 addr_len); 1108 else 1109 result = kernel_setsockopt(sctp_con->sock, SOL_SCTP, 1110 SCTP_SOCKOPT_BINDX_ADD, 1111 (char *)addr, addr_len); 1112 1113 if (result < 0) 1114 log_print("Can't bind to port %d addr number %d", 1115 dlm_config.ci_tcp_port, num); 1116 1117 return result; 1118 } 1119 1120 /* Initialise SCTP socket and bind to all interfaces */ 1121 static int sctp_listen_for_all(void) 1122 { 1123 struct socket *sock = NULL; 1124 struct sockaddr_storage localaddr; 1125 struct sctp_event_subscribe subscribe; 1126 int result = -EINVAL, num = 1, i, addr_len; 1127 struct connection *con = nodeid2con(0, GFP_NOFS); 1128 int bufsize = NEEDED_RMEM; 1129 1130 if (!con) 1131 return -ENOMEM; 1132 1133 log_print("Using SCTP for communications"); 1134 1135 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_SEQPACKET, 1136 IPPROTO_SCTP, &sock); 1137 if (result < 0) { 1138 log_print("Can't create comms socket, check SCTP is loaded"); 1139 goto out; 1140 } 1141 1142 /* Listen for events */ 1143 memset(&subscribe, 0, sizeof(subscribe)); 1144 subscribe.sctp_data_io_event = 1; 1145 subscribe.sctp_association_event = 1; 1146 subscribe.sctp_send_failure_event = 1; 1147 subscribe.sctp_shutdown_event = 1; 1148 subscribe.sctp_partial_delivery_event = 1; 1149 1150 result = kernel_setsockopt(sock, SOL_SOCKET, SO_RCVBUFFORCE, 1151 (char *)&bufsize, sizeof(bufsize)); 1152 if (result) 1153 log_print("Error increasing buffer space on socket %d", result); 1154 1155 result = kernel_setsockopt(sock, SOL_SCTP, SCTP_EVENTS, 1156 (char *)&subscribe, sizeof(subscribe)); 1157 if (result < 0) { 1158 log_print("Failed to set SCTP_EVENTS on socket: result=%d", 1159 result); 1160 goto create_delsock; 1161 } 1162 1163 /* Init con struct */ 1164 sock->sk->sk_user_data = con; 1165 con->sock = sock; 1166 con->sock->sk->sk_data_ready = lowcomms_data_ready; 1167 con->rx_action = receive_from_sock; 1168 con->connect_action = sctp_init_assoc; 1169 1170 /* Bind to all interfaces. */ 1171 for (i = 0; i < dlm_local_count; i++) { 1172 memcpy(&localaddr, dlm_local_addr[i], sizeof(localaddr)); 1173 make_sockaddr(&localaddr, dlm_config.ci_tcp_port, &addr_len); 1174 1175 result = add_sctp_bind_addr(con, &localaddr, addr_len, num); 1176 if (result) 1177 goto create_delsock; 1178 ++num; 1179 } 1180 1181 result = sock->ops->listen(sock, 5); 1182 if (result < 0) { 1183 log_print("Can't set socket listening"); 1184 goto create_delsock; 1185 } 1186 1187 return 0; 1188 1189 create_delsock: 1190 sock_release(sock); 1191 con->sock = NULL; 1192 out: 1193 return result; 1194 } 1195 1196 static int tcp_listen_for_all(void) 1197 { 1198 struct socket *sock = NULL; 1199 struct connection *con = nodeid2con(0, GFP_NOFS); 1200 int result = -EINVAL; 1201 1202 if (!con) 1203 return -ENOMEM; 1204 1205 /* We don't support multi-homed hosts */ 1206 if (dlm_local_addr[1] != NULL) { 1207 log_print("TCP protocol can't handle multi-homed hosts, " 1208 "try SCTP"); 1209 return -EINVAL; 1210 } 1211 1212 log_print("Using TCP for communications"); 1213 1214 sock = tcp_create_listen_sock(con, dlm_local_addr[0]); 1215 if (sock) { 1216 add_sock(sock, con); 1217 result = 0; 1218 } 1219 else { 1220 result = -EADDRINUSE; 1221 } 1222 1223 return result; 1224 } 1225 1226 1227 1228 static struct writequeue_entry *new_writequeue_entry(struct connection *con, 1229 gfp_t allocation) 1230 { 1231 struct writequeue_entry *entry; 1232 1233 entry = kmalloc(sizeof(struct writequeue_entry), allocation); 1234 if (!entry) 1235 return NULL; 1236 1237 entry->page = alloc_page(allocation); 1238 if (!entry->page) { 1239 kfree(entry); 1240 return NULL; 1241 } 1242 1243 entry->offset = 0; 1244 entry->len = 0; 1245 entry->end = 0; 1246 entry->users = 0; 1247 entry->con = con; 1248 1249 return entry; 1250 } 1251 1252 void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc) 1253 { 1254 struct connection *con; 1255 struct writequeue_entry *e; 1256 int offset = 0; 1257 int users = 0; 1258 1259 con = nodeid2con(nodeid, allocation); 1260 if (!con) 1261 return NULL; 1262 1263 spin_lock(&con->writequeue_lock); 1264 e = list_entry(con->writequeue.prev, struct writequeue_entry, list); 1265 if ((&e->list == &con->writequeue) || 1266 (PAGE_CACHE_SIZE - e->end < len)) { 1267 e = NULL; 1268 } else { 1269 offset = e->end; 1270 e->end += len; 1271 users = e->users++; 1272 } 1273 spin_unlock(&con->writequeue_lock); 1274 1275 if (e) { 1276 got_one: 1277 *ppc = page_address(e->page) + offset; 1278 return e; 1279 } 1280 1281 e = new_writequeue_entry(con, allocation); 1282 if (e) { 1283 spin_lock(&con->writequeue_lock); 1284 offset = e->end; 1285 e->end += len; 1286 users = e->users++; 1287 list_add_tail(&e->list, &con->writequeue); 1288 spin_unlock(&con->writequeue_lock); 1289 goto got_one; 1290 } 1291 return NULL; 1292 } 1293 1294 void dlm_lowcomms_commit_buffer(void *mh) 1295 { 1296 struct writequeue_entry *e = (struct writequeue_entry *)mh; 1297 struct connection *con = e->con; 1298 int users; 1299 1300 spin_lock(&con->writequeue_lock); 1301 users = --e->users; 1302 if (users) 1303 goto out; 1304 e->len = e->end - e->offset; 1305 spin_unlock(&con->writequeue_lock); 1306 1307 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) { 1308 queue_work(send_workqueue, &con->swork); 1309 } 1310 return; 1311 1312 out: 1313 spin_unlock(&con->writequeue_lock); 1314 return; 1315 } 1316 1317 /* Send a message */ 1318 static void send_to_sock(struct connection *con) 1319 { 1320 int ret = 0; 1321 const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL; 1322 struct writequeue_entry *e; 1323 int len, offset; 1324 int count = 0; 1325 1326 mutex_lock(&con->sock_mutex); 1327 if (con->sock == NULL) 1328 goto out_connect; 1329 1330 spin_lock(&con->writequeue_lock); 1331 for (;;) { 1332 e = list_entry(con->writequeue.next, struct writequeue_entry, 1333 list); 1334 if ((struct list_head *) e == &con->writequeue) 1335 break; 1336 1337 len = e->len; 1338 offset = e->offset; 1339 BUG_ON(len == 0 && e->users == 0); 1340 spin_unlock(&con->writequeue_lock); 1341 1342 ret = 0; 1343 if (len) { 1344 ret = kernel_sendpage(con->sock, e->page, offset, len, 1345 msg_flags); 1346 if (ret == -EAGAIN || ret == 0) { 1347 if (ret == -EAGAIN && 1348 test_bit(SOCK_ASYNC_NOSPACE, &con->sock->flags) && 1349 !test_and_set_bit(CF_APP_LIMITED, &con->flags)) { 1350 /* Notify TCP that we're limited by the 1351 * application window size. 1352 */ 1353 set_bit(SOCK_NOSPACE, &con->sock->flags); 1354 con->sock->sk->sk_write_pending++; 1355 } 1356 cond_resched(); 1357 goto out; 1358 } 1359 if (ret <= 0) 1360 goto send_error; 1361 } 1362 1363 /* Don't starve people filling buffers */ 1364 if (++count >= MAX_SEND_MSG_COUNT) { 1365 cond_resched(); 1366 count = 0; 1367 } 1368 1369 spin_lock(&con->writequeue_lock); 1370 e->offset += ret; 1371 e->len -= ret; 1372 1373 if (e->len == 0 && e->users == 0) { 1374 list_del(&e->list); 1375 free_entry(e); 1376 continue; 1377 } 1378 } 1379 spin_unlock(&con->writequeue_lock); 1380 out: 1381 mutex_unlock(&con->sock_mutex); 1382 return; 1383 1384 send_error: 1385 mutex_unlock(&con->sock_mutex); 1386 close_connection(con, false); 1387 lowcomms_connect_sock(con); 1388 return; 1389 1390 out_connect: 1391 mutex_unlock(&con->sock_mutex); 1392 if (!test_bit(CF_INIT_PENDING, &con->flags)) 1393 lowcomms_connect_sock(con); 1394 return; 1395 } 1396 1397 static void clean_one_writequeue(struct connection *con) 1398 { 1399 struct writequeue_entry *e, *safe; 1400 1401 spin_lock(&con->writequeue_lock); 1402 list_for_each_entry_safe(e, safe, &con->writequeue, list) { 1403 list_del(&e->list); 1404 free_entry(e); 1405 } 1406 spin_unlock(&con->writequeue_lock); 1407 } 1408 1409 /* Called from recovery when it knows that a node has 1410 left the cluster */ 1411 int dlm_lowcomms_close(int nodeid) 1412 { 1413 struct connection *con; 1414 1415 log_print("closing connection to node %d", nodeid); 1416 con = nodeid2con(nodeid, 0); 1417 if (con) { 1418 clear_bit(CF_CONNECT_PENDING, &con->flags); 1419 clear_bit(CF_WRITE_PENDING, &con->flags); 1420 set_bit(CF_CLOSE, &con->flags); 1421 if (cancel_work_sync(&con->swork)) 1422 log_print("canceled swork for node %d", nodeid); 1423 if (cancel_work_sync(&con->rwork)) 1424 log_print("canceled rwork for node %d", nodeid); 1425 clean_one_writequeue(con); 1426 close_connection(con, true); 1427 } 1428 return 0; 1429 } 1430 1431 /* Receive workqueue function */ 1432 static void process_recv_sockets(struct work_struct *work) 1433 { 1434 struct connection *con = container_of(work, struct connection, rwork); 1435 int err; 1436 1437 clear_bit(CF_READ_PENDING, &con->flags); 1438 do { 1439 err = con->rx_action(con); 1440 } while (!err); 1441 } 1442 1443 /* Send workqueue function */ 1444 static void process_send_sockets(struct work_struct *work) 1445 { 1446 struct connection *con = container_of(work, struct connection, swork); 1447 1448 if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) { 1449 con->connect_action(con); 1450 set_bit(CF_WRITE_PENDING, &con->flags); 1451 } 1452 if (test_and_clear_bit(CF_WRITE_PENDING, &con->flags)) 1453 send_to_sock(con); 1454 } 1455 1456 1457 /* Discard all entries on the write queues */ 1458 static void clean_writequeues(void) 1459 { 1460 foreach_conn(clean_one_writequeue); 1461 } 1462 1463 static void work_stop(void) 1464 { 1465 destroy_workqueue(recv_workqueue); 1466 destroy_workqueue(send_workqueue); 1467 } 1468 1469 static int work_start(void) 1470 { 1471 recv_workqueue = create_singlethread_workqueue("dlm_recv"); 1472 if (!recv_workqueue) { 1473 log_print("can't start dlm_recv"); 1474 return -ENOMEM; 1475 } 1476 1477 send_workqueue = create_singlethread_workqueue("dlm_send"); 1478 if (!send_workqueue) { 1479 log_print("can't start dlm_send"); 1480 destroy_workqueue(recv_workqueue); 1481 return -ENOMEM; 1482 } 1483 1484 return 0; 1485 } 1486 1487 static void stop_conn(struct connection *con) 1488 { 1489 con->flags |= 0x0F; 1490 if (con->sock && con->sock->sk) 1491 con->sock->sk->sk_user_data = NULL; 1492 } 1493 1494 static void free_conn(struct connection *con) 1495 { 1496 close_connection(con, true); 1497 if (con->othercon) 1498 kmem_cache_free(con_cache, con->othercon); 1499 hlist_del(&con->list); 1500 kmem_cache_free(con_cache, con); 1501 } 1502 1503 void dlm_lowcomms_stop(void) 1504 { 1505 /* Set all the flags to prevent any 1506 socket activity. 1507 */ 1508 mutex_lock(&connections_lock); 1509 foreach_conn(stop_conn); 1510 mutex_unlock(&connections_lock); 1511 1512 work_stop(); 1513 1514 mutex_lock(&connections_lock); 1515 clean_writequeues(); 1516 1517 foreach_conn(free_conn); 1518 1519 mutex_unlock(&connections_lock); 1520 kmem_cache_destroy(con_cache); 1521 } 1522 1523 int dlm_lowcomms_start(void) 1524 { 1525 int error = -EINVAL; 1526 struct connection *con; 1527 int i; 1528 1529 for (i = 0; i < CONN_HASH_SIZE; i++) 1530 INIT_HLIST_HEAD(&connection_hash[i]); 1531 1532 init_local(); 1533 if (!dlm_local_count) { 1534 error = -ENOTCONN; 1535 log_print("no local IP address has been set"); 1536 goto out; 1537 } 1538 1539 error = -ENOMEM; 1540 con_cache = kmem_cache_create("dlm_conn", sizeof(struct connection), 1541 __alignof__(struct connection), 0, 1542 NULL); 1543 if (!con_cache) 1544 goto out; 1545 1546 /* Start listening */ 1547 if (dlm_config.ci_protocol == 0) 1548 error = tcp_listen_for_all(); 1549 else 1550 error = sctp_listen_for_all(); 1551 if (error) 1552 goto fail_unlisten; 1553 1554 error = work_start(); 1555 if (error) 1556 goto fail_unlisten; 1557 1558 return 0; 1559 1560 fail_unlisten: 1561 con = nodeid2con(0,0); 1562 if (con) { 1563 close_connection(con, false); 1564 kmem_cache_free(con_cache, con); 1565 } 1566 kmem_cache_destroy(con_cache); 1567 1568 out: 1569 return error; 1570 } 1571