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 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 unsigned char *b=(unsigned char *)&prim.ssp_addr; 516 log_print("reject connect from unknown addr"); 517 print_hex_dump_bytes("ss: ", DUMP_PREFIX_NONE, 518 b, sizeof(struct sockaddr_storage)); 519 sctp_send_shutdown(prim.ssp_assoc_id); 520 return; 521 } 522 523 new_con = nodeid2con(nodeid, GFP_NOFS); 524 if (!new_con) 525 return; 526 527 /* Peel off a new sock */ 528 parg.associd = sn->sn_assoc_change.sac_assoc_id; 529 ret = kernel_getsockopt(con->sock, IPPROTO_SCTP, 530 SCTP_SOCKOPT_PEELOFF, 531 (void *)&parg, &parglen); 532 if (ret < 0) { 533 log_print("Can't peel off a socket for " 534 "connection %d to node %d: err=%d", 535 parg.associd, nodeid, ret); 536 return; 537 } 538 new_con->sock = sockfd_lookup(parg.sd, &err); 539 if (!new_con->sock) { 540 log_print("sockfd_lookup error %d", err); 541 return; 542 } 543 add_sock(new_con->sock, new_con); 544 sockfd_put(new_con->sock); 545 546 log_print("connecting to %d sctp association %d", 547 nodeid, (int)sn->sn_assoc_change.sac_assoc_id); 548 549 /* Send any pending writes */ 550 clear_bit(CF_CONNECT_PENDING, &new_con->flags); 551 clear_bit(CF_INIT_PENDING, &con->flags); 552 if (!test_and_set_bit(CF_WRITE_PENDING, &new_con->flags)) { 553 queue_work(send_workqueue, &new_con->swork); 554 } 555 if (!test_and_set_bit(CF_READ_PENDING, &new_con->flags)) 556 queue_work(recv_workqueue, &new_con->rwork); 557 } 558 break; 559 560 case SCTP_COMM_LOST: 561 case SCTP_SHUTDOWN_COMP: 562 { 563 con = assoc2con(sn->sn_assoc_change.sac_assoc_id); 564 if (con) { 565 con->sctp_assoc = 0; 566 } 567 } 568 break; 569 570 /* We don't know which INIT failed, so clear the PENDING flags 571 * on them all. if assoc_id is zero then it will then try 572 * again */ 573 574 case SCTP_CANT_STR_ASSOC: 575 { 576 log_print("Can't start SCTP association - retrying"); 577 sctp_init_failed(); 578 } 579 break; 580 581 default: 582 log_print("unexpected SCTP assoc change id=%d state=%d", 583 (int)sn->sn_assoc_change.sac_assoc_id, 584 sn->sn_assoc_change.sac_state); 585 } 586 } 587 } 588 589 /* Data received from remote end */ 590 static int receive_from_sock(struct connection *con) 591 { 592 int ret = 0; 593 struct msghdr msg = {}; 594 struct kvec iov[2]; 595 unsigned len; 596 int r; 597 int call_again_soon = 0; 598 int nvec; 599 char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 600 601 mutex_lock(&con->sock_mutex); 602 603 if (con->sock == NULL) { 604 ret = -EAGAIN; 605 goto out_close; 606 } 607 608 if (con->rx_page == NULL) { 609 /* 610 * This doesn't need to be atomic, but I think it should 611 * improve performance if it is. 612 */ 613 con->rx_page = alloc_page(GFP_ATOMIC); 614 if (con->rx_page == NULL) 615 goto out_resched; 616 cbuf_init(&con->cb, PAGE_CACHE_SIZE); 617 } 618 619 /* Only SCTP needs these really */ 620 memset(&incmsg, 0, sizeof(incmsg)); 621 msg.msg_control = incmsg; 622 msg.msg_controllen = sizeof(incmsg); 623 624 /* 625 * iov[0] is the bit of the circular buffer between the current end 626 * point (cb.base + cb.len) and the end of the buffer. 627 */ 628 iov[0].iov_len = con->cb.base - cbuf_data(&con->cb); 629 iov[0].iov_base = page_address(con->rx_page) + cbuf_data(&con->cb); 630 iov[1].iov_len = 0; 631 nvec = 1; 632 633 /* 634 * iov[1] is the bit of the circular buffer between the start of the 635 * buffer and the start of the currently used section (cb.base) 636 */ 637 if (cbuf_data(&con->cb) >= con->cb.base) { 638 iov[0].iov_len = PAGE_CACHE_SIZE - cbuf_data(&con->cb); 639 iov[1].iov_len = con->cb.base; 640 iov[1].iov_base = page_address(con->rx_page); 641 nvec = 2; 642 } 643 len = iov[0].iov_len + iov[1].iov_len; 644 645 r = ret = kernel_recvmsg(con->sock, &msg, iov, nvec, len, 646 MSG_DONTWAIT | MSG_NOSIGNAL); 647 if (ret <= 0) 648 goto out_close; 649 650 /* Process SCTP notifications */ 651 if (msg.msg_flags & MSG_NOTIFICATION) { 652 msg.msg_control = incmsg; 653 msg.msg_controllen = sizeof(incmsg); 654 655 process_sctp_notification(con, &msg, 656 page_address(con->rx_page) + con->cb.base); 657 mutex_unlock(&con->sock_mutex); 658 return 0; 659 } 660 BUG_ON(con->nodeid == 0); 661 662 if (ret == len) 663 call_again_soon = 1; 664 cbuf_add(&con->cb, ret); 665 ret = dlm_process_incoming_buffer(con->nodeid, 666 page_address(con->rx_page), 667 con->cb.base, con->cb.len, 668 PAGE_CACHE_SIZE); 669 if (ret == -EBADMSG) { 670 log_print("lowcomms: addr=%p, base=%u, len=%u, " 671 "iov_len=%u, iov_base[0]=%p, read=%d", 672 page_address(con->rx_page), con->cb.base, con->cb.len, 673 len, iov[0].iov_base, r); 674 } 675 if (ret < 0) 676 goto out_close; 677 cbuf_eat(&con->cb, ret); 678 679 if (cbuf_empty(&con->cb) && !call_again_soon) { 680 __free_page(con->rx_page); 681 con->rx_page = NULL; 682 } 683 684 if (call_again_soon) 685 goto out_resched; 686 mutex_unlock(&con->sock_mutex); 687 return 0; 688 689 out_resched: 690 if (!test_and_set_bit(CF_READ_PENDING, &con->flags)) 691 queue_work(recv_workqueue, &con->rwork); 692 mutex_unlock(&con->sock_mutex); 693 return -EAGAIN; 694 695 out_close: 696 mutex_unlock(&con->sock_mutex); 697 if (ret != -EAGAIN) { 698 close_connection(con, false); 699 /* Reconnect when there is something to send */ 700 } 701 /* Don't return success if we really got EOF */ 702 if (ret == 0) 703 ret = -EAGAIN; 704 705 return ret; 706 } 707 708 /* Listening socket is busy, accept a connection */ 709 static int tcp_accept_from_sock(struct connection *con) 710 { 711 int result; 712 struct sockaddr_storage peeraddr; 713 struct socket *newsock; 714 int len; 715 int nodeid; 716 struct connection *newcon; 717 struct connection *addcon; 718 719 memset(&peeraddr, 0, sizeof(peeraddr)); 720 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 721 IPPROTO_TCP, &newsock); 722 if (result < 0) 723 return -ENOMEM; 724 725 mutex_lock_nested(&con->sock_mutex, 0); 726 727 result = -ENOTCONN; 728 if (con->sock == NULL) 729 goto accept_err; 730 731 newsock->type = con->sock->type; 732 newsock->ops = con->sock->ops; 733 734 result = con->sock->ops->accept(con->sock, newsock, O_NONBLOCK); 735 if (result < 0) 736 goto accept_err; 737 738 /* Get the connected socket's peer */ 739 memset(&peeraddr, 0, sizeof(peeraddr)); 740 if (newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr, 741 &len, 2)) { 742 result = -ECONNABORTED; 743 goto accept_err; 744 } 745 746 /* Get the new node's NODEID */ 747 make_sockaddr(&peeraddr, 0, &len); 748 if (dlm_addr_to_nodeid(&peeraddr, &nodeid)) { 749 unsigned char *b=(unsigned char *)&peeraddr; 750 log_print("connect from non cluster node"); 751 print_hex_dump_bytes("ss: ", DUMP_PREFIX_NONE, 752 b, sizeof(struct sockaddr_storage)); 753 sock_release(newsock); 754 mutex_unlock(&con->sock_mutex); 755 return -1; 756 } 757 758 log_print("got connection from %d", nodeid); 759 760 /* Check to see if we already have a connection to this node. This 761 * could happen if the two nodes initiate a connection at roughly 762 * the same time and the connections cross on the wire. 763 * In this case we store the incoming one in "othercon" 764 */ 765 newcon = nodeid2con(nodeid, GFP_NOFS); 766 if (!newcon) { 767 result = -ENOMEM; 768 goto accept_err; 769 } 770 mutex_lock_nested(&newcon->sock_mutex, 1); 771 if (newcon->sock) { 772 struct connection *othercon = newcon->othercon; 773 774 if (!othercon) { 775 othercon = kmem_cache_zalloc(con_cache, GFP_NOFS); 776 if (!othercon) { 777 log_print("failed to allocate incoming socket"); 778 mutex_unlock(&newcon->sock_mutex); 779 result = -ENOMEM; 780 goto accept_err; 781 } 782 othercon->nodeid = nodeid; 783 othercon->rx_action = receive_from_sock; 784 mutex_init(&othercon->sock_mutex); 785 INIT_WORK(&othercon->swork, process_send_sockets); 786 INIT_WORK(&othercon->rwork, process_recv_sockets); 787 set_bit(CF_IS_OTHERCON, &othercon->flags); 788 } 789 if (!othercon->sock) { 790 newcon->othercon = othercon; 791 othercon->sock = newsock; 792 newsock->sk->sk_user_data = othercon; 793 add_sock(newsock, othercon); 794 addcon = othercon; 795 } 796 else { 797 printk("Extra connection from node %d attempted\n", nodeid); 798 result = -EAGAIN; 799 mutex_unlock(&newcon->sock_mutex); 800 goto accept_err; 801 } 802 } 803 else { 804 newsock->sk->sk_user_data = newcon; 805 newcon->rx_action = receive_from_sock; 806 add_sock(newsock, newcon); 807 addcon = newcon; 808 } 809 810 mutex_unlock(&newcon->sock_mutex); 811 812 /* 813 * Add it to the active queue in case we got data 814 * between processing the accept adding the socket 815 * to the read_sockets list 816 */ 817 if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags)) 818 queue_work(recv_workqueue, &addcon->rwork); 819 mutex_unlock(&con->sock_mutex); 820 821 return 0; 822 823 accept_err: 824 mutex_unlock(&con->sock_mutex); 825 sock_release(newsock); 826 827 if (result != -EAGAIN) 828 log_print("error accepting connection from node: %d", result); 829 return result; 830 } 831 832 static void free_entry(struct writequeue_entry *e) 833 { 834 __free_page(e->page); 835 kfree(e); 836 } 837 838 /* Initiate an SCTP association. 839 This is a special case of send_to_sock() in that we don't yet have a 840 peeled-off socket for this association, so we use the listening socket 841 and add the primary IP address of the remote node. 842 */ 843 static void sctp_init_assoc(struct connection *con) 844 { 845 struct sockaddr_storage rem_addr; 846 char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 847 struct msghdr outmessage; 848 struct cmsghdr *cmsg; 849 struct sctp_sndrcvinfo *sinfo; 850 struct connection *base_con; 851 struct writequeue_entry *e; 852 int len, offset; 853 int ret; 854 int addrlen; 855 struct kvec iov[1]; 856 857 if (test_and_set_bit(CF_INIT_PENDING, &con->flags)) 858 return; 859 860 if (con->retries++ > MAX_CONNECT_RETRIES) 861 return; 862 863 if (nodeid_to_addr(con->nodeid, (struct sockaddr *)&rem_addr)) { 864 log_print("no address for nodeid %d", con->nodeid); 865 return; 866 } 867 base_con = nodeid2con(0, 0); 868 BUG_ON(base_con == NULL); 869 870 make_sockaddr(&rem_addr, dlm_config.ci_tcp_port, &addrlen); 871 872 outmessage.msg_name = &rem_addr; 873 outmessage.msg_namelen = addrlen; 874 outmessage.msg_control = outcmsg; 875 outmessage.msg_controllen = sizeof(outcmsg); 876 outmessage.msg_flags = MSG_EOR; 877 878 spin_lock(&con->writequeue_lock); 879 880 if (list_empty(&con->writequeue)) { 881 spin_unlock(&con->writequeue_lock); 882 log_print("writequeue empty for nodeid %d", con->nodeid); 883 return; 884 } 885 886 e = list_first_entry(&con->writequeue, struct writequeue_entry, list); 887 len = e->len; 888 offset = e->offset; 889 spin_unlock(&con->writequeue_lock); 890 891 /* Send the first block off the write queue */ 892 iov[0].iov_base = page_address(e->page)+offset; 893 iov[0].iov_len = len; 894 895 cmsg = CMSG_FIRSTHDR(&outmessage); 896 cmsg->cmsg_level = IPPROTO_SCTP; 897 cmsg->cmsg_type = SCTP_SNDRCV; 898 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo)); 899 sinfo = CMSG_DATA(cmsg); 900 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo)); 901 sinfo->sinfo_ppid = cpu_to_le32(dlm_our_nodeid()); 902 outmessage.msg_controllen = cmsg->cmsg_len; 903 904 ret = kernel_sendmsg(base_con->sock, &outmessage, iov, 1, len); 905 if (ret < 0) { 906 log_print("Send first packet to node %d failed: %d", 907 con->nodeid, ret); 908 909 /* Try again later */ 910 clear_bit(CF_CONNECT_PENDING, &con->flags); 911 clear_bit(CF_INIT_PENDING, &con->flags); 912 } 913 else { 914 spin_lock(&con->writequeue_lock); 915 e->offset += ret; 916 e->len -= ret; 917 918 if (e->len == 0 && e->users == 0) { 919 list_del(&e->list); 920 free_entry(e); 921 } 922 spin_unlock(&con->writequeue_lock); 923 } 924 } 925 926 /* Connect a new socket to its peer */ 927 static void tcp_connect_to_sock(struct connection *con) 928 { 929 int result = -EHOSTUNREACH; 930 struct sockaddr_storage saddr, src_addr; 931 int addr_len; 932 struct socket *sock = NULL; 933 int one = 1; 934 935 if (con->nodeid == 0) { 936 log_print("attempt to connect sock 0 foiled"); 937 return; 938 } 939 940 mutex_lock(&con->sock_mutex); 941 if (con->retries++ > MAX_CONNECT_RETRIES) 942 goto out; 943 944 /* Some odd races can cause double-connects, ignore them */ 945 if (con->sock) { 946 result = 0; 947 goto out; 948 } 949 950 /* Create a socket to communicate with */ 951 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 952 IPPROTO_TCP, &sock); 953 if (result < 0) 954 goto out_err; 955 956 memset(&saddr, 0, sizeof(saddr)); 957 if (dlm_nodeid_to_addr(con->nodeid, &saddr)) 958 goto out_err; 959 960 sock->sk->sk_user_data = con; 961 con->rx_action = receive_from_sock; 962 con->connect_action = tcp_connect_to_sock; 963 add_sock(sock, con); 964 965 /* Bind to our cluster-known address connecting to avoid 966 routing problems */ 967 memcpy(&src_addr, dlm_local_addr[0], sizeof(src_addr)); 968 make_sockaddr(&src_addr, 0, &addr_len); 969 result = sock->ops->bind(sock, (struct sockaddr *) &src_addr, 970 addr_len); 971 if (result < 0) { 972 log_print("could not bind for connect: %d", result); 973 /* This *may* not indicate a critical error */ 974 } 975 976 make_sockaddr(&saddr, dlm_config.ci_tcp_port, &addr_len); 977 978 log_print("connecting to %d", con->nodeid); 979 980 /* Turn off Nagle's algorithm */ 981 kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY, (char *)&one, 982 sizeof(one)); 983 984 result = 985 sock->ops->connect(sock, (struct sockaddr *)&saddr, addr_len, 986 O_NONBLOCK); 987 if (result == -EINPROGRESS) 988 result = 0; 989 if (result == 0) 990 goto out; 991 992 out_err: 993 if (con->sock) { 994 sock_release(con->sock); 995 con->sock = NULL; 996 } else if (sock) { 997 sock_release(sock); 998 } 999 /* 1000 * Some errors are fatal and this list might need adjusting. For other 1001 * errors we try again until the max number of retries is reached. 1002 */ 1003 if (result != -EHOSTUNREACH && result != -ENETUNREACH && 1004 result != -ENETDOWN && result != -EINVAL 1005 && result != -EPROTONOSUPPORT) { 1006 lowcomms_connect_sock(con); 1007 result = 0; 1008 } 1009 out: 1010 mutex_unlock(&con->sock_mutex); 1011 return; 1012 } 1013 1014 static struct socket *tcp_create_listen_sock(struct connection *con, 1015 struct sockaddr_storage *saddr) 1016 { 1017 struct socket *sock = NULL; 1018 int result = 0; 1019 int one = 1; 1020 int addr_len; 1021 1022 if (dlm_local_addr[0]->ss_family == AF_INET) 1023 addr_len = sizeof(struct sockaddr_in); 1024 else 1025 addr_len = sizeof(struct sockaddr_in6); 1026 1027 /* Create a socket to communicate with */ 1028 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 1029 IPPROTO_TCP, &sock); 1030 if (result < 0) { 1031 log_print("Can't create listening comms socket"); 1032 goto create_out; 1033 } 1034 1035 /* Turn off Nagle's algorithm */ 1036 kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY, (char *)&one, 1037 sizeof(one)); 1038 1039 result = kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, 1040 (char *)&one, sizeof(one)); 1041 1042 if (result < 0) { 1043 log_print("Failed to set SO_REUSEADDR on socket: %d", result); 1044 } 1045 sock->sk->sk_user_data = con; 1046 con->rx_action = tcp_accept_from_sock; 1047 con->connect_action = tcp_connect_to_sock; 1048 con->sock = sock; 1049 1050 /* Bind to our port */ 1051 make_sockaddr(saddr, dlm_config.ci_tcp_port, &addr_len); 1052 result = sock->ops->bind(sock, (struct sockaddr *) saddr, addr_len); 1053 if (result < 0) { 1054 log_print("Can't bind to port %d", dlm_config.ci_tcp_port); 1055 sock_release(sock); 1056 sock = NULL; 1057 con->sock = NULL; 1058 goto create_out; 1059 } 1060 result = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, 1061 (char *)&one, sizeof(one)); 1062 if (result < 0) { 1063 log_print("Set keepalive failed: %d", result); 1064 } 1065 1066 result = sock->ops->listen(sock, 5); 1067 if (result < 0) { 1068 log_print("Can't listen on port %d", dlm_config.ci_tcp_port); 1069 sock_release(sock); 1070 sock = NULL; 1071 goto create_out; 1072 } 1073 1074 create_out: 1075 return sock; 1076 } 1077 1078 /* Get local addresses */ 1079 static void init_local(void) 1080 { 1081 struct sockaddr_storage sas, *addr; 1082 int i; 1083 1084 dlm_local_count = 0; 1085 for (i = 0; i < DLM_MAX_ADDR_COUNT - 1; i++) { 1086 if (dlm_our_addr(&sas, i)) 1087 break; 1088 1089 addr = kmalloc(sizeof(*addr), GFP_NOFS); 1090 if (!addr) 1091 break; 1092 memcpy(addr, &sas, sizeof(*addr)); 1093 dlm_local_addr[dlm_local_count++] = addr; 1094 } 1095 } 1096 1097 /* Bind to an IP address. SCTP allows multiple address so it can do 1098 multi-homing */ 1099 static int add_sctp_bind_addr(struct connection *sctp_con, 1100 struct sockaddr_storage *addr, 1101 int addr_len, int num) 1102 { 1103 int result = 0; 1104 1105 if (num == 1) 1106 result = kernel_bind(sctp_con->sock, 1107 (struct sockaddr *) addr, 1108 addr_len); 1109 else 1110 result = kernel_setsockopt(sctp_con->sock, SOL_SCTP, 1111 SCTP_SOCKOPT_BINDX_ADD, 1112 (char *)addr, addr_len); 1113 1114 if (result < 0) 1115 log_print("Can't bind to port %d addr number %d", 1116 dlm_config.ci_tcp_port, num); 1117 1118 return result; 1119 } 1120 1121 /* Initialise SCTP socket and bind to all interfaces */ 1122 static int sctp_listen_for_all(void) 1123 { 1124 struct socket *sock = NULL; 1125 struct sockaddr_storage localaddr; 1126 struct sctp_event_subscribe subscribe; 1127 int result = -EINVAL, num = 1, i, addr_len; 1128 struct connection *con = nodeid2con(0, GFP_NOFS); 1129 int bufsize = NEEDED_RMEM; 1130 1131 if (!con) 1132 return -ENOMEM; 1133 1134 log_print("Using SCTP for communications"); 1135 1136 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_SEQPACKET, 1137 IPPROTO_SCTP, &sock); 1138 if (result < 0) { 1139 log_print("Can't create comms socket, check SCTP is loaded"); 1140 goto out; 1141 } 1142 1143 /* Listen for events */ 1144 memset(&subscribe, 0, sizeof(subscribe)); 1145 subscribe.sctp_data_io_event = 1; 1146 subscribe.sctp_association_event = 1; 1147 subscribe.sctp_send_failure_event = 1; 1148 subscribe.sctp_shutdown_event = 1; 1149 subscribe.sctp_partial_delivery_event = 1; 1150 1151 result = kernel_setsockopt(sock, SOL_SOCKET, SO_RCVBUFFORCE, 1152 (char *)&bufsize, sizeof(bufsize)); 1153 if (result) 1154 log_print("Error increasing buffer space on socket %d", result); 1155 1156 result = kernel_setsockopt(sock, SOL_SCTP, SCTP_EVENTS, 1157 (char *)&subscribe, sizeof(subscribe)); 1158 if (result < 0) { 1159 log_print("Failed to set SCTP_EVENTS on socket: result=%d", 1160 result); 1161 goto create_delsock; 1162 } 1163 1164 /* Init con struct */ 1165 sock->sk->sk_user_data = con; 1166 con->sock = sock; 1167 con->sock->sk->sk_data_ready = lowcomms_data_ready; 1168 con->rx_action = receive_from_sock; 1169 con->connect_action = sctp_init_assoc; 1170 1171 /* Bind to all interfaces. */ 1172 for (i = 0; i < dlm_local_count; i++) { 1173 memcpy(&localaddr, dlm_local_addr[i], sizeof(localaddr)); 1174 make_sockaddr(&localaddr, dlm_config.ci_tcp_port, &addr_len); 1175 1176 result = add_sctp_bind_addr(con, &localaddr, addr_len, num); 1177 if (result) 1178 goto create_delsock; 1179 ++num; 1180 } 1181 1182 result = sock->ops->listen(sock, 5); 1183 if (result < 0) { 1184 log_print("Can't set socket listening"); 1185 goto create_delsock; 1186 } 1187 1188 return 0; 1189 1190 create_delsock: 1191 sock_release(sock); 1192 con->sock = NULL; 1193 out: 1194 return result; 1195 } 1196 1197 static int tcp_listen_for_all(void) 1198 { 1199 struct socket *sock = NULL; 1200 struct connection *con = nodeid2con(0, GFP_NOFS); 1201 int result = -EINVAL; 1202 1203 if (!con) 1204 return -ENOMEM; 1205 1206 /* We don't support multi-homed hosts */ 1207 if (dlm_local_addr[1] != NULL) { 1208 log_print("TCP protocol can't handle multi-homed hosts, " 1209 "try SCTP"); 1210 return -EINVAL; 1211 } 1212 1213 log_print("Using TCP for communications"); 1214 1215 sock = tcp_create_listen_sock(con, dlm_local_addr[0]); 1216 if (sock) { 1217 add_sock(sock, con); 1218 result = 0; 1219 } 1220 else { 1221 result = -EADDRINUSE; 1222 } 1223 1224 return result; 1225 } 1226 1227 1228 1229 static struct writequeue_entry *new_writequeue_entry(struct connection *con, 1230 gfp_t allocation) 1231 { 1232 struct writequeue_entry *entry; 1233 1234 entry = kmalloc(sizeof(struct writequeue_entry), allocation); 1235 if (!entry) 1236 return NULL; 1237 1238 entry->page = alloc_page(allocation); 1239 if (!entry->page) { 1240 kfree(entry); 1241 return NULL; 1242 } 1243 1244 entry->offset = 0; 1245 entry->len = 0; 1246 entry->end = 0; 1247 entry->users = 0; 1248 entry->con = con; 1249 1250 return entry; 1251 } 1252 1253 void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc) 1254 { 1255 struct connection *con; 1256 struct writequeue_entry *e; 1257 int offset = 0; 1258 int users = 0; 1259 1260 con = nodeid2con(nodeid, allocation); 1261 if (!con) 1262 return NULL; 1263 1264 spin_lock(&con->writequeue_lock); 1265 e = list_entry(con->writequeue.prev, struct writequeue_entry, list); 1266 if ((&e->list == &con->writequeue) || 1267 (PAGE_CACHE_SIZE - e->end < len)) { 1268 e = NULL; 1269 } else { 1270 offset = e->end; 1271 e->end += len; 1272 users = e->users++; 1273 } 1274 spin_unlock(&con->writequeue_lock); 1275 1276 if (e) { 1277 got_one: 1278 *ppc = page_address(e->page) + offset; 1279 return e; 1280 } 1281 1282 e = new_writequeue_entry(con, allocation); 1283 if (e) { 1284 spin_lock(&con->writequeue_lock); 1285 offset = e->end; 1286 e->end += len; 1287 users = e->users++; 1288 list_add_tail(&e->list, &con->writequeue); 1289 spin_unlock(&con->writequeue_lock); 1290 goto got_one; 1291 } 1292 return NULL; 1293 } 1294 1295 void dlm_lowcomms_commit_buffer(void *mh) 1296 { 1297 struct writequeue_entry *e = (struct writequeue_entry *)mh; 1298 struct connection *con = e->con; 1299 int users; 1300 1301 spin_lock(&con->writequeue_lock); 1302 users = --e->users; 1303 if (users) 1304 goto out; 1305 e->len = e->end - e->offset; 1306 spin_unlock(&con->writequeue_lock); 1307 1308 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) { 1309 queue_work(send_workqueue, &con->swork); 1310 } 1311 return; 1312 1313 out: 1314 spin_unlock(&con->writequeue_lock); 1315 return; 1316 } 1317 1318 /* Send a message */ 1319 static void send_to_sock(struct connection *con) 1320 { 1321 int ret = 0; 1322 const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL; 1323 struct writequeue_entry *e; 1324 int len, offset; 1325 int count = 0; 1326 1327 mutex_lock(&con->sock_mutex); 1328 if (con->sock == NULL) 1329 goto out_connect; 1330 1331 spin_lock(&con->writequeue_lock); 1332 for (;;) { 1333 e = list_entry(con->writequeue.next, struct writequeue_entry, 1334 list); 1335 if ((struct list_head *) e == &con->writequeue) 1336 break; 1337 1338 len = e->len; 1339 offset = e->offset; 1340 BUG_ON(len == 0 && e->users == 0); 1341 spin_unlock(&con->writequeue_lock); 1342 1343 ret = 0; 1344 if (len) { 1345 ret = kernel_sendpage(con->sock, e->page, offset, len, 1346 msg_flags); 1347 if (ret == -EAGAIN || ret == 0) { 1348 if (ret == -EAGAIN && 1349 test_bit(SOCK_ASYNC_NOSPACE, &con->sock->flags) && 1350 !test_and_set_bit(CF_APP_LIMITED, &con->flags)) { 1351 /* Notify TCP that we're limited by the 1352 * application window size. 1353 */ 1354 set_bit(SOCK_NOSPACE, &con->sock->flags); 1355 con->sock->sk->sk_write_pending++; 1356 } 1357 cond_resched(); 1358 goto out; 1359 } 1360 if (ret <= 0) 1361 goto send_error; 1362 } 1363 1364 /* Don't starve people filling buffers */ 1365 if (++count >= MAX_SEND_MSG_COUNT) { 1366 cond_resched(); 1367 count = 0; 1368 } 1369 1370 spin_lock(&con->writequeue_lock); 1371 e->offset += ret; 1372 e->len -= ret; 1373 1374 if (e->len == 0 && e->users == 0) { 1375 list_del(&e->list); 1376 free_entry(e); 1377 continue; 1378 } 1379 } 1380 spin_unlock(&con->writequeue_lock); 1381 out: 1382 mutex_unlock(&con->sock_mutex); 1383 return; 1384 1385 send_error: 1386 mutex_unlock(&con->sock_mutex); 1387 close_connection(con, false); 1388 lowcomms_connect_sock(con); 1389 return; 1390 1391 out_connect: 1392 mutex_unlock(&con->sock_mutex); 1393 if (!test_bit(CF_INIT_PENDING, &con->flags)) 1394 lowcomms_connect_sock(con); 1395 return; 1396 } 1397 1398 static void clean_one_writequeue(struct connection *con) 1399 { 1400 struct writequeue_entry *e, *safe; 1401 1402 spin_lock(&con->writequeue_lock); 1403 list_for_each_entry_safe(e, safe, &con->writequeue, list) { 1404 list_del(&e->list); 1405 free_entry(e); 1406 } 1407 spin_unlock(&con->writequeue_lock); 1408 } 1409 1410 /* Called from recovery when it knows that a node has 1411 left the cluster */ 1412 int dlm_lowcomms_close(int nodeid) 1413 { 1414 struct connection *con; 1415 1416 log_print("closing connection to node %d", nodeid); 1417 con = nodeid2con(nodeid, 0); 1418 if (con) { 1419 clear_bit(CF_CONNECT_PENDING, &con->flags); 1420 clear_bit(CF_WRITE_PENDING, &con->flags); 1421 set_bit(CF_CLOSE, &con->flags); 1422 if (cancel_work_sync(&con->swork)) 1423 log_print("canceled swork for node %d", nodeid); 1424 if (cancel_work_sync(&con->rwork)) 1425 log_print("canceled rwork for node %d", nodeid); 1426 clean_one_writequeue(con); 1427 close_connection(con, true); 1428 } 1429 return 0; 1430 } 1431 1432 /* Receive workqueue function */ 1433 static void process_recv_sockets(struct work_struct *work) 1434 { 1435 struct connection *con = container_of(work, struct connection, rwork); 1436 int err; 1437 1438 clear_bit(CF_READ_PENDING, &con->flags); 1439 do { 1440 err = con->rx_action(con); 1441 } while (!err); 1442 } 1443 1444 /* Send workqueue function */ 1445 static void process_send_sockets(struct work_struct *work) 1446 { 1447 struct connection *con = container_of(work, struct connection, swork); 1448 1449 if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) { 1450 con->connect_action(con); 1451 set_bit(CF_WRITE_PENDING, &con->flags); 1452 } 1453 if (test_and_clear_bit(CF_WRITE_PENDING, &con->flags)) 1454 send_to_sock(con); 1455 } 1456 1457 1458 /* Discard all entries on the write queues */ 1459 static void clean_writequeues(void) 1460 { 1461 foreach_conn(clean_one_writequeue); 1462 } 1463 1464 static void work_stop(void) 1465 { 1466 destroy_workqueue(recv_workqueue); 1467 destroy_workqueue(send_workqueue); 1468 } 1469 1470 static int work_start(void) 1471 { 1472 recv_workqueue = alloc_workqueue("dlm_recv", 1473 WQ_UNBOUND | WQ_MEM_RECLAIM, 1); 1474 if (!recv_workqueue) { 1475 log_print("can't start dlm_recv"); 1476 return -ENOMEM; 1477 } 1478 1479 send_workqueue = alloc_workqueue("dlm_send", 1480 WQ_UNBOUND | WQ_MEM_RECLAIM, 1); 1481 if (!send_workqueue) { 1482 log_print("can't start dlm_send"); 1483 destroy_workqueue(recv_workqueue); 1484 return -ENOMEM; 1485 } 1486 1487 return 0; 1488 } 1489 1490 static void stop_conn(struct connection *con) 1491 { 1492 con->flags |= 0x0F; 1493 if (con->sock && con->sock->sk) 1494 con->sock->sk->sk_user_data = NULL; 1495 } 1496 1497 static void free_conn(struct connection *con) 1498 { 1499 close_connection(con, true); 1500 if (con->othercon) 1501 kmem_cache_free(con_cache, con->othercon); 1502 hlist_del(&con->list); 1503 kmem_cache_free(con_cache, con); 1504 } 1505 1506 void dlm_lowcomms_stop(void) 1507 { 1508 /* Set all the flags to prevent any 1509 socket activity. 1510 */ 1511 mutex_lock(&connections_lock); 1512 foreach_conn(stop_conn); 1513 mutex_unlock(&connections_lock); 1514 1515 work_stop(); 1516 1517 mutex_lock(&connections_lock); 1518 clean_writequeues(); 1519 1520 foreach_conn(free_conn); 1521 1522 mutex_unlock(&connections_lock); 1523 kmem_cache_destroy(con_cache); 1524 } 1525 1526 int dlm_lowcomms_start(void) 1527 { 1528 int error = -EINVAL; 1529 struct connection *con; 1530 int i; 1531 1532 for (i = 0; i < CONN_HASH_SIZE; i++) 1533 INIT_HLIST_HEAD(&connection_hash[i]); 1534 1535 init_local(); 1536 if (!dlm_local_count) { 1537 error = -ENOTCONN; 1538 log_print("no local IP address has been set"); 1539 goto out; 1540 } 1541 1542 error = -ENOMEM; 1543 con_cache = kmem_cache_create("dlm_conn", sizeof(struct connection), 1544 __alignof__(struct connection), 0, 1545 NULL); 1546 if (!con_cache) 1547 goto out; 1548 1549 /* Start listening */ 1550 if (dlm_config.ci_protocol == 0) 1551 error = tcp_listen_for_all(); 1552 else 1553 error = sctp_listen_for_all(); 1554 if (error) 1555 goto fail_unlisten; 1556 1557 error = work_start(); 1558 if (error) 1559 goto fail_unlisten; 1560 1561 return 0; 1562 1563 fail_unlisten: 1564 con = nodeid2con(0,0); 1565 if (con) { 1566 close_connection(con, false); 1567 kmem_cache_free(con_cache, con); 1568 } 1569 kmem_cache_destroy(con_cache); 1570 1571 out: 1572 return error; 1573 } 1574