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/sctp.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 bool try_new_addr; 129 }; 130 #define sock2con(x) ((struct connection *)(x)->sk_user_data) 131 132 /* An entry waiting to be sent */ 133 struct writequeue_entry { 134 struct list_head list; 135 struct page *page; 136 int offset; 137 int len; 138 int end; 139 int users; 140 struct connection *con; 141 }; 142 143 struct dlm_node_addr { 144 struct list_head list; 145 int nodeid; 146 int addr_count; 147 int curr_addr_index; 148 struct sockaddr_storage *addr[DLM_MAX_ADDR_COUNT]; 149 }; 150 151 static LIST_HEAD(dlm_node_addrs); 152 static DEFINE_SPINLOCK(dlm_node_addrs_spin); 153 154 static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT]; 155 static int dlm_local_count; 156 static int dlm_allow_conn; 157 158 /* Work queues */ 159 static struct workqueue_struct *recv_workqueue; 160 static struct workqueue_struct *send_workqueue; 161 162 static struct hlist_head connection_hash[CONN_HASH_SIZE]; 163 static DEFINE_MUTEX(connections_lock); 164 static struct kmem_cache *con_cache; 165 166 static void process_recv_sockets(struct work_struct *work); 167 static void process_send_sockets(struct work_struct *work); 168 169 170 /* This is deliberately very simple because most clusters have simple 171 sequential nodeids, so we should be able to go straight to a connection 172 struct in the array */ 173 static inline int nodeid_hash(int nodeid) 174 { 175 return nodeid & (CONN_HASH_SIZE-1); 176 } 177 178 static struct connection *__find_con(int nodeid) 179 { 180 int r; 181 struct connection *con; 182 183 r = nodeid_hash(nodeid); 184 185 hlist_for_each_entry(con, &connection_hash[r], list) { 186 if (con->nodeid == nodeid) 187 return con; 188 } 189 return NULL; 190 } 191 192 /* 193 * If 'allocation' is zero then we don't attempt to create a new 194 * connection structure for this node. 195 */ 196 static struct connection *__nodeid2con(int nodeid, gfp_t alloc) 197 { 198 struct connection *con = NULL; 199 int r; 200 201 con = __find_con(nodeid); 202 if (con || !alloc) 203 return con; 204 205 con = kmem_cache_zalloc(con_cache, alloc); 206 if (!con) 207 return NULL; 208 209 r = nodeid_hash(nodeid); 210 hlist_add_head(&con->list, &connection_hash[r]); 211 212 con->nodeid = nodeid; 213 mutex_init(&con->sock_mutex); 214 INIT_LIST_HEAD(&con->writequeue); 215 spin_lock_init(&con->writequeue_lock); 216 INIT_WORK(&con->swork, process_send_sockets); 217 INIT_WORK(&con->rwork, process_recv_sockets); 218 219 /* Setup action pointers for child sockets */ 220 if (con->nodeid) { 221 struct connection *zerocon = __find_con(0); 222 223 con->connect_action = zerocon->connect_action; 224 if (!con->rx_action) 225 con->rx_action = zerocon->rx_action; 226 } 227 228 return con; 229 } 230 231 /* Loop round all connections */ 232 static void foreach_conn(void (*conn_func)(struct connection *c)) 233 { 234 int i; 235 struct hlist_node *n; 236 struct connection *con; 237 238 for (i = 0; i < CONN_HASH_SIZE; i++) { 239 hlist_for_each_entry_safe(con, n, &connection_hash[i], list) 240 conn_func(con); 241 } 242 } 243 244 static struct connection *nodeid2con(int nodeid, gfp_t allocation) 245 { 246 struct connection *con; 247 248 mutex_lock(&connections_lock); 249 con = __nodeid2con(nodeid, allocation); 250 mutex_unlock(&connections_lock); 251 252 return con; 253 } 254 255 /* This is a bit drastic, but only called when things go wrong */ 256 static struct connection *assoc2con(int assoc_id) 257 { 258 int i; 259 struct connection *con; 260 261 mutex_lock(&connections_lock); 262 263 for (i = 0 ; i < CONN_HASH_SIZE; i++) { 264 hlist_for_each_entry(con, &connection_hash[i], list) { 265 if (con->sctp_assoc == assoc_id) { 266 mutex_unlock(&connections_lock); 267 return con; 268 } 269 } 270 } 271 mutex_unlock(&connections_lock); 272 return NULL; 273 } 274 275 static struct dlm_node_addr *find_node_addr(int nodeid) 276 { 277 struct dlm_node_addr *na; 278 279 list_for_each_entry(na, &dlm_node_addrs, list) { 280 if (na->nodeid == nodeid) 281 return na; 282 } 283 return NULL; 284 } 285 286 static int addr_compare(struct sockaddr_storage *x, struct sockaddr_storage *y) 287 { 288 switch (x->ss_family) { 289 case AF_INET: { 290 struct sockaddr_in *sinx = (struct sockaddr_in *)x; 291 struct sockaddr_in *siny = (struct sockaddr_in *)y; 292 if (sinx->sin_addr.s_addr != siny->sin_addr.s_addr) 293 return 0; 294 if (sinx->sin_port != siny->sin_port) 295 return 0; 296 break; 297 } 298 case AF_INET6: { 299 struct sockaddr_in6 *sinx = (struct sockaddr_in6 *)x; 300 struct sockaddr_in6 *siny = (struct sockaddr_in6 *)y; 301 if (!ipv6_addr_equal(&sinx->sin6_addr, &siny->sin6_addr)) 302 return 0; 303 if (sinx->sin6_port != siny->sin6_port) 304 return 0; 305 break; 306 } 307 default: 308 return 0; 309 } 310 return 1; 311 } 312 313 static int nodeid_to_addr(int nodeid, struct sockaddr_storage *sas_out, 314 struct sockaddr *sa_out, bool try_new_addr) 315 { 316 struct sockaddr_storage sas; 317 struct dlm_node_addr *na; 318 319 if (!dlm_local_count) 320 return -1; 321 322 spin_lock(&dlm_node_addrs_spin); 323 na = find_node_addr(nodeid); 324 if (na && na->addr_count) { 325 if (try_new_addr) { 326 na->curr_addr_index++; 327 if (na->curr_addr_index == na->addr_count) 328 na->curr_addr_index = 0; 329 } 330 331 memcpy(&sas, na->addr[na->curr_addr_index ], 332 sizeof(struct sockaddr_storage)); 333 } 334 spin_unlock(&dlm_node_addrs_spin); 335 336 if (!na) 337 return -EEXIST; 338 339 if (!na->addr_count) 340 return -ENOENT; 341 342 if (sas_out) 343 memcpy(sas_out, &sas, sizeof(struct sockaddr_storage)); 344 345 if (!sa_out) 346 return 0; 347 348 if (dlm_local_addr[0]->ss_family == AF_INET) { 349 struct sockaddr_in *in4 = (struct sockaddr_in *) &sas; 350 struct sockaddr_in *ret4 = (struct sockaddr_in *) sa_out; 351 ret4->sin_addr.s_addr = in4->sin_addr.s_addr; 352 } else { 353 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) &sas; 354 struct sockaddr_in6 *ret6 = (struct sockaddr_in6 *) sa_out; 355 ret6->sin6_addr = in6->sin6_addr; 356 } 357 358 return 0; 359 } 360 361 static int addr_to_nodeid(struct sockaddr_storage *addr, int *nodeid) 362 { 363 struct dlm_node_addr *na; 364 int rv = -EEXIST; 365 int addr_i; 366 367 spin_lock(&dlm_node_addrs_spin); 368 list_for_each_entry(na, &dlm_node_addrs, list) { 369 if (!na->addr_count) 370 continue; 371 372 for (addr_i = 0; addr_i < na->addr_count; addr_i++) { 373 if (addr_compare(na->addr[addr_i], addr)) { 374 *nodeid = na->nodeid; 375 rv = 0; 376 goto unlock; 377 } 378 } 379 } 380 unlock: 381 spin_unlock(&dlm_node_addrs_spin); 382 return rv; 383 } 384 385 int dlm_lowcomms_addr(int nodeid, struct sockaddr_storage *addr, int len) 386 { 387 struct sockaddr_storage *new_addr; 388 struct dlm_node_addr *new_node, *na; 389 390 new_node = kzalloc(sizeof(struct dlm_node_addr), GFP_NOFS); 391 if (!new_node) 392 return -ENOMEM; 393 394 new_addr = kzalloc(sizeof(struct sockaddr_storage), GFP_NOFS); 395 if (!new_addr) { 396 kfree(new_node); 397 return -ENOMEM; 398 } 399 400 memcpy(new_addr, addr, len); 401 402 spin_lock(&dlm_node_addrs_spin); 403 na = find_node_addr(nodeid); 404 if (!na) { 405 new_node->nodeid = nodeid; 406 new_node->addr[0] = new_addr; 407 new_node->addr_count = 1; 408 list_add(&new_node->list, &dlm_node_addrs); 409 spin_unlock(&dlm_node_addrs_spin); 410 return 0; 411 } 412 413 if (na->addr_count >= DLM_MAX_ADDR_COUNT) { 414 spin_unlock(&dlm_node_addrs_spin); 415 kfree(new_addr); 416 kfree(new_node); 417 return -ENOSPC; 418 } 419 420 na->addr[na->addr_count++] = new_addr; 421 spin_unlock(&dlm_node_addrs_spin); 422 kfree(new_node); 423 return 0; 424 } 425 426 /* Data available on socket or listen socket received a connect */ 427 static void lowcomms_data_ready(struct sock *sk, int count_unused) 428 { 429 struct connection *con = sock2con(sk); 430 if (con && !test_and_set_bit(CF_READ_PENDING, &con->flags)) 431 queue_work(recv_workqueue, &con->rwork); 432 } 433 434 static void lowcomms_write_space(struct sock *sk) 435 { 436 struct connection *con = sock2con(sk); 437 438 if (!con) 439 return; 440 441 clear_bit(SOCK_NOSPACE, &con->sock->flags); 442 443 if (test_and_clear_bit(CF_APP_LIMITED, &con->flags)) { 444 con->sock->sk->sk_write_pending--; 445 clear_bit(SOCK_ASYNC_NOSPACE, &con->sock->flags); 446 } 447 448 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) 449 queue_work(send_workqueue, &con->swork); 450 } 451 452 static inline void lowcomms_connect_sock(struct connection *con) 453 { 454 if (test_bit(CF_CLOSE, &con->flags)) 455 return; 456 if (!test_and_set_bit(CF_CONNECT_PENDING, &con->flags)) 457 queue_work(send_workqueue, &con->swork); 458 } 459 460 static void lowcomms_state_change(struct sock *sk) 461 { 462 if (sk->sk_state == TCP_ESTABLISHED) 463 lowcomms_write_space(sk); 464 } 465 466 int dlm_lowcomms_connect_node(int nodeid) 467 { 468 struct connection *con; 469 470 /* with sctp there's no connecting without sending */ 471 if (dlm_config.ci_protocol != 0) 472 return 0; 473 474 if (nodeid == dlm_our_nodeid()) 475 return 0; 476 477 con = nodeid2con(nodeid, GFP_NOFS); 478 if (!con) 479 return -ENOMEM; 480 lowcomms_connect_sock(con); 481 return 0; 482 } 483 484 /* Make a socket active */ 485 static void add_sock(struct socket *sock, struct connection *con) 486 { 487 con->sock = sock; 488 489 /* Install a data_ready callback */ 490 con->sock->sk->sk_data_ready = lowcomms_data_ready; 491 con->sock->sk->sk_write_space = lowcomms_write_space; 492 con->sock->sk->sk_state_change = lowcomms_state_change; 493 con->sock->sk->sk_user_data = con; 494 con->sock->sk->sk_allocation = GFP_NOFS; 495 } 496 497 /* Add the port number to an IPv6 or 4 sockaddr and return the address 498 length */ 499 static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port, 500 int *addr_len) 501 { 502 saddr->ss_family = dlm_local_addr[0]->ss_family; 503 if (saddr->ss_family == AF_INET) { 504 struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr; 505 in4_addr->sin_port = cpu_to_be16(port); 506 *addr_len = sizeof(struct sockaddr_in); 507 memset(&in4_addr->sin_zero, 0, sizeof(in4_addr->sin_zero)); 508 } else { 509 struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr; 510 in6_addr->sin6_port = cpu_to_be16(port); 511 *addr_len = sizeof(struct sockaddr_in6); 512 } 513 memset((char *)saddr + *addr_len, 0, sizeof(struct sockaddr_storage) - *addr_len); 514 } 515 516 /* Close a remote connection and tidy up */ 517 static void close_connection(struct connection *con, bool and_other) 518 { 519 mutex_lock(&con->sock_mutex); 520 521 if (con->sock) { 522 sock_release(con->sock); 523 con->sock = NULL; 524 } 525 if (con->othercon && and_other) { 526 /* Will only re-enter once. */ 527 close_connection(con->othercon, false); 528 } 529 if (con->rx_page) { 530 __free_page(con->rx_page); 531 con->rx_page = NULL; 532 } 533 534 con->retries = 0; 535 mutex_unlock(&con->sock_mutex); 536 } 537 538 /* We only send shutdown messages to nodes that are not part of the cluster */ 539 static void sctp_send_shutdown(sctp_assoc_t associd) 540 { 541 static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 542 struct msghdr outmessage; 543 struct cmsghdr *cmsg; 544 struct sctp_sndrcvinfo *sinfo; 545 int ret; 546 struct connection *con; 547 548 con = nodeid2con(0,0); 549 BUG_ON(con == NULL); 550 551 outmessage.msg_name = NULL; 552 outmessage.msg_namelen = 0; 553 outmessage.msg_control = outcmsg; 554 outmessage.msg_controllen = sizeof(outcmsg); 555 outmessage.msg_flags = MSG_EOR; 556 557 cmsg = CMSG_FIRSTHDR(&outmessage); 558 cmsg->cmsg_level = IPPROTO_SCTP; 559 cmsg->cmsg_type = SCTP_SNDRCV; 560 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo)); 561 outmessage.msg_controllen = cmsg->cmsg_len; 562 sinfo = CMSG_DATA(cmsg); 563 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo)); 564 565 sinfo->sinfo_flags |= MSG_EOF; 566 sinfo->sinfo_assoc_id = associd; 567 568 ret = kernel_sendmsg(con->sock, &outmessage, NULL, 0, 0); 569 570 if (ret != 0) 571 log_print("send EOF to node failed: %d", ret); 572 } 573 574 static void sctp_init_failed_foreach(struct connection *con) 575 { 576 577 /* 578 * Don't try to recover base con and handle race where the 579 * other node's assoc init creates a assoc and we get that 580 * notification, then we get a notification that our attempt 581 * failed due. This happens when we are still trying the primary 582 * address, but the other node has already tried secondary addrs 583 * and found one that worked. 584 */ 585 if (!con->nodeid || con->sctp_assoc) 586 return; 587 588 log_print("Retrying SCTP association init for node %d\n", con->nodeid); 589 590 con->try_new_addr = true; 591 con->sctp_assoc = 0; 592 if (test_and_clear_bit(CF_INIT_PENDING, &con->flags)) { 593 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) 594 queue_work(send_workqueue, &con->swork); 595 } 596 } 597 598 /* INIT failed but we don't know which node... 599 restart INIT on all pending nodes */ 600 static void sctp_init_failed(void) 601 { 602 mutex_lock(&connections_lock); 603 604 foreach_conn(sctp_init_failed_foreach); 605 606 mutex_unlock(&connections_lock); 607 } 608 609 static void retry_failed_sctp_send(struct connection *recv_con, 610 struct sctp_send_failed *sn_send_failed, 611 char *buf) 612 { 613 int len = sn_send_failed->ssf_length - sizeof(struct sctp_send_failed); 614 struct dlm_mhandle *mh; 615 struct connection *con; 616 char *retry_buf; 617 int nodeid = sn_send_failed->ssf_info.sinfo_ppid; 618 619 log_print("Retry sending %d bytes to node id %d", len, nodeid); 620 621 con = nodeid2con(nodeid, 0); 622 if (!con) { 623 log_print("Could not look up con for nodeid %d\n", 624 nodeid); 625 return; 626 } 627 628 mh = dlm_lowcomms_get_buffer(nodeid, len, GFP_NOFS, &retry_buf); 629 if (!mh) { 630 log_print("Could not allocate buf for retry."); 631 return; 632 } 633 memcpy(retry_buf, buf + sizeof(struct sctp_send_failed), len); 634 dlm_lowcomms_commit_buffer(mh); 635 636 /* 637 * If we got a assoc changed event before the send failed event then 638 * we only need to retry the send. 639 */ 640 if (con->sctp_assoc) { 641 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) 642 queue_work(send_workqueue, &con->swork); 643 } else 644 sctp_init_failed_foreach(con); 645 } 646 647 /* Something happened to an association */ 648 static void process_sctp_notification(struct connection *con, 649 struct msghdr *msg, char *buf) 650 { 651 union sctp_notification *sn = (union sctp_notification *)buf; 652 653 switch (sn->sn_header.sn_type) { 654 case SCTP_SEND_FAILED: 655 retry_failed_sctp_send(con, &sn->sn_send_failed, buf); 656 break; 657 case SCTP_ASSOC_CHANGE: 658 switch (sn->sn_assoc_change.sac_state) { 659 case SCTP_COMM_UP: 660 case SCTP_RESTART: 661 { 662 /* Check that the new node is in the lockspace */ 663 struct sctp_prim prim; 664 int nodeid; 665 int prim_len, ret; 666 int addr_len; 667 struct connection *new_con; 668 669 /* 670 * We get this before any data for an association. 671 * We verify that the node is in the cluster and 672 * then peel off a socket for it. 673 */ 674 if ((int)sn->sn_assoc_change.sac_assoc_id <= 0) { 675 log_print("COMM_UP for invalid assoc ID %d", 676 (int)sn->sn_assoc_change.sac_assoc_id); 677 sctp_init_failed(); 678 return; 679 } 680 memset(&prim, 0, sizeof(struct sctp_prim)); 681 prim_len = sizeof(struct sctp_prim); 682 prim.ssp_assoc_id = sn->sn_assoc_change.sac_assoc_id; 683 684 ret = kernel_getsockopt(con->sock, 685 IPPROTO_SCTP, 686 SCTP_PRIMARY_ADDR, 687 (char*)&prim, 688 &prim_len); 689 if (ret < 0) { 690 log_print("getsockopt/sctp_primary_addr on " 691 "new assoc %d failed : %d", 692 (int)sn->sn_assoc_change.sac_assoc_id, 693 ret); 694 695 /* Retry INIT later */ 696 new_con = assoc2con(sn->sn_assoc_change.sac_assoc_id); 697 if (new_con) 698 clear_bit(CF_CONNECT_PENDING, &con->flags); 699 return; 700 } 701 make_sockaddr(&prim.ssp_addr, 0, &addr_len); 702 if (addr_to_nodeid(&prim.ssp_addr, &nodeid)) { 703 unsigned char *b=(unsigned char *)&prim.ssp_addr; 704 log_print("reject connect from unknown addr"); 705 print_hex_dump_bytes("ss: ", DUMP_PREFIX_NONE, 706 b, sizeof(struct sockaddr_storage)); 707 sctp_send_shutdown(prim.ssp_assoc_id); 708 return; 709 } 710 711 new_con = nodeid2con(nodeid, GFP_NOFS); 712 if (!new_con) 713 return; 714 715 /* Peel off a new sock */ 716 lock_sock(con->sock->sk); 717 ret = sctp_do_peeloff(con->sock->sk, 718 sn->sn_assoc_change.sac_assoc_id, 719 &new_con->sock); 720 release_sock(con->sock->sk); 721 if (ret < 0) { 722 log_print("Can't peel off a socket for " 723 "connection %d to node %d: err=%d", 724 (int)sn->sn_assoc_change.sac_assoc_id, 725 nodeid, ret); 726 return; 727 } 728 add_sock(new_con->sock, new_con); 729 730 log_print("connecting to %d sctp association %d", 731 nodeid, (int)sn->sn_assoc_change.sac_assoc_id); 732 733 new_con->sctp_assoc = sn->sn_assoc_change.sac_assoc_id; 734 new_con->try_new_addr = false; 735 /* Send any pending writes */ 736 clear_bit(CF_CONNECT_PENDING, &new_con->flags); 737 clear_bit(CF_INIT_PENDING, &new_con->flags); 738 if (!test_and_set_bit(CF_WRITE_PENDING, &new_con->flags)) { 739 queue_work(send_workqueue, &new_con->swork); 740 } 741 if (!test_and_set_bit(CF_READ_PENDING, &new_con->flags)) 742 queue_work(recv_workqueue, &new_con->rwork); 743 } 744 break; 745 746 case SCTP_COMM_LOST: 747 case SCTP_SHUTDOWN_COMP: 748 { 749 con = assoc2con(sn->sn_assoc_change.sac_assoc_id); 750 if (con) { 751 con->sctp_assoc = 0; 752 } 753 } 754 break; 755 756 case SCTP_CANT_STR_ASSOC: 757 { 758 /* Will retry init when we get the send failed notification */ 759 log_print("Can't start SCTP association - retrying"); 760 } 761 break; 762 763 default: 764 log_print("unexpected SCTP assoc change id=%d state=%d", 765 (int)sn->sn_assoc_change.sac_assoc_id, 766 sn->sn_assoc_change.sac_state); 767 } 768 default: 769 ; /* fall through */ 770 } 771 } 772 773 /* Data received from remote end */ 774 static int receive_from_sock(struct connection *con) 775 { 776 int ret = 0; 777 struct msghdr msg = {}; 778 struct kvec iov[2]; 779 unsigned len; 780 int r; 781 int call_again_soon = 0; 782 int nvec; 783 char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 784 785 mutex_lock(&con->sock_mutex); 786 787 if (con->sock == NULL) { 788 ret = -EAGAIN; 789 goto out_close; 790 } 791 792 if (con->rx_page == NULL) { 793 /* 794 * This doesn't need to be atomic, but I think it should 795 * improve performance if it is. 796 */ 797 con->rx_page = alloc_page(GFP_ATOMIC); 798 if (con->rx_page == NULL) 799 goto out_resched; 800 cbuf_init(&con->cb, PAGE_CACHE_SIZE); 801 } 802 803 /* Only SCTP needs these really */ 804 memset(&incmsg, 0, sizeof(incmsg)); 805 msg.msg_control = incmsg; 806 msg.msg_controllen = sizeof(incmsg); 807 808 /* 809 * iov[0] is the bit of the circular buffer between the current end 810 * point (cb.base + cb.len) and the end of the buffer. 811 */ 812 iov[0].iov_len = con->cb.base - cbuf_data(&con->cb); 813 iov[0].iov_base = page_address(con->rx_page) + cbuf_data(&con->cb); 814 iov[1].iov_len = 0; 815 nvec = 1; 816 817 /* 818 * iov[1] is the bit of the circular buffer between the start of the 819 * buffer and the start of the currently used section (cb.base) 820 */ 821 if (cbuf_data(&con->cb) >= con->cb.base) { 822 iov[0].iov_len = PAGE_CACHE_SIZE - cbuf_data(&con->cb); 823 iov[1].iov_len = con->cb.base; 824 iov[1].iov_base = page_address(con->rx_page); 825 nvec = 2; 826 } 827 len = iov[0].iov_len + iov[1].iov_len; 828 829 r = ret = kernel_recvmsg(con->sock, &msg, iov, nvec, len, 830 MSG_DONTWAIT | MSG_NOSIGNAL); 831 if (ret <= 0) 832 goto out_close; 833 834 /* Process SCTP notifications */ 835 if (msg.msg_flags & MSG_NOTIFICATION) { 836 msg.msg_control = incmsg; 837 msg.msg_controllen = sizeof(incmsg); 838 839 process_sctp_notification(con, &msg, 840 page_address(con->rx_page) + con->cb.base); 841 mutex_unlock(&con->sock_mutex); 842 return 0; 843 } 844 BUG_ON(con->nodeid == 0); 845 846 if (ret == len) 847 call_again_soon = 1; 848 cbuf_add(&con->cb, ret); 849 ret = dlm_process_incoming_buffer(con->nodeid, 850 page_address(con->rx_page), 851 con->cb.base, con->cb.len, 852 PAGE_CACHE_SIZE); 853 if (ret == -EBADMSG) { 854 log_print("lowcomms: addr=%p, base=%u, len=%u, " 855 "iov_len=%u, iov_base[0]=%p, read=%d", 856 page_address(con->rx_page), con->cb.base, con->cb.len, 857 len, iov[0].iov_base, r); 858 } 859 if (ret < 0) 860 goto out_close; 861 cbuf_eat(&con->cb, ret); 862 863 if (cbuf_empty(&con->cb) && !call_again_soon) { 864 __free_page(con->rx_page); 865 con->rx_page = NULL; 866 } 867 868 if (call_again_soon) 869 goto out_resched; 870 mutex_unlock(&con->sock_mutex); 871 return 0; 872 873 out_resched: 874 if (!test_and_set_bit(CF_READ_PENDING, &con->flags)) 875 queue_work(recv_workqueue, &con->rwork); 876 mutex_unlock(&con->sock_mutex); 877 return -EAGAIN; 878 879 out_close: 880 mutex_unlock(&con->sock_mutex); 881 if (ret != -EAGAIN) { 882 close_connection(con, false); 883 /* Reconnect when there is something to send */ 884 } 885 /* Don't return success if we really got EOF */ 886 if (ret == 0) 887 ret = -EAGAIN; 888 889 return ret; 890 } 891 892 /* Listening socket is busy, accept a connection */ 893 static int tcp_accept_from_sock(struct connection *con) 894 { 895 int result; 896 struct sockaddr_storage peeraddr; 897 struct socket *newsock; 898 int len; 899 int nodeid; 900 struct connection *newcon; 901 struct connection *addcon; 902 903 mutex_lock(&connections_lock); 904 if (!dlm_allow_conn) { 905 mutex_unlock(&connections_lock); 906 return -1; 907 } 908 mutex_unlock(&connections_lock); 909 910 memset(&peeraddr, 0, sizeof(peeraddr)); 911 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 912 IPPROTO_TCP, &newsock); 913 if (result < 0) 914 return -ENOMEM; 915 916 mutex_lock_nested(&con->sock_mutex, 0); 917 918 result = -ENOTCONN; 919 if (con->sock == NULL) 920 goto accept_err; 921 922 newsock->type = con->sock->type; 923 newsock->ops = con->sock->ops; 924 925 result = con->sock->ops->accept(con->sock, newsock, O_NONBLOCK); 926 if (result < 0) 927 goto accept_err; 928 929 /* Get the connected socket's peer */ 930 memset(&peeraddr, 0, sizeof(peeraddr)); 931 if (newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr, 932 &len, 2)) { 933 result = -ECONNABORTED; 934 goto accept_err; 935 } 936 937 /* Get the new node's NODEID */ 938 make_sockaddr(&peeraddr, 0, &len); 939 if (addr_to_nodeid(&peeraddr, &nodeid)) { 940 unsigned char *b=(unsigned char *)&peeraddr; 941 log_print("connect from non cluster node"); 942 print_hex_dump_bytes("ss: ", DUMP_PREFIX_NONE, 943 b, sizeof(struct sockaddr_storage)); 944 sock_release(newsock); 945 mutex_unlock(&con->sock_mutex); 946 return -1; 947 } 948 949 log_print("got connection from %d", nodeid); 950 951 /* Check to see if we already have a connection to this node. This 952 * could happen if the two nodes initiate a connection at roughly 953 * the same time and the connections cross on the wire. 954 * In this case we store the incoming one in "othercon" 955 */ 956 newcon = nodeid2con(nodeid, GFP_NOFS); 957 if (!newcon) { 958 result = -ENOMEM; 959 goto accept_err; 960 } 961 mutex_lock_nested(&newcon->sock_mutex, 1); 962 if (newcon->sock) { 963 struct connection *othercon = newcon->othercon; 964 965 if (!othercon) { 966 othercon = kmem_cache_zalloc(con_cache, GFP_NOFS); 967 if (!othercon) { 968 log_print("failed to allocate incoming socket"); 969 mutex_unlock(&newcon->sock_mutex); 970 result = -ENOMEM; 971 goto accept_err; 972 } 973 othercon->nodeid = nodeid; 974 othercon->rx_action = receive_from_sock; 975 mutex_init(&othercon->sock_mutex); 976 INIT_WORK(&othercon->swork, process_send_sockets); 977 INIT_WORK(&othercon->rwork, process_recv_sockets); 978 set_bit(CF_IS_OTHERCON, &othercon->flags); 979 } 980 if (!othercon->sock) { 981 newcon->othercon = othercon; 982 othercon->sock = newsock; 983 newsock->sk->sk_user_data = othercon; 984 add_sock(newsock, othercon); 985 addcon = othercon; 986 } 987 else { 988 printk("Extra connection from node %d attempted\n", nodeid); 989 result = -EAGAIN; 990 mutex_unlock(&newcon->sock_mutex); 991 goto accept_err; 992 } 993 } 994 else { 995 newsock->sk->sk_user_data = newcon; 996 newcon->rx_action = receive_from_sock; 997 add_sock(newsock, newcon); 998 addcon = newcon; 999 } 1000 1001 mutex_unlock(&newcon->sock_mutex); 1002 1003 /* 1004 * Add it to the active queue in case we got data 1005 * between processing the accept adding the socket 1006 * to the read_sockets list 1007 */ 1008 if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags)) 1009 queue_work(recv_workqueue, &addcon->rwork); 1010 mutex_unlock(&con->sock_mutex); 1011 1012 return 0; 1013 1014 accept_err: 1015 mutex_unlock(&con->sock_mutex); 1016 sock_release(newsock); 1017 1018 if (result != -EAGAIN) 1019 log_print("error accepting connection from node: %d", result); 1020 return result; 1021 } 1022 1023 static void free_entry(struct writequeue_entry *e) 1024 { 1025 __free_page(e->page); 1026 kfree(e); 1027 } 1028 1029 /* 1030 * writequeue_entry_complete - try to delete and free write queue entry 1031 * @e: write queue entry to try to delete 1032 * @completed: bytes completed 1033 * 1034 * writequeue_lock must be held. 1035 */ 1036 static void writequeue_entry_complete(struct writequeue_entry *e, int completed) 1037 { 1038 e->offset += completed; 1039 e->len -= completed; 1040 1041 if (e->len == 0 && e->users == 0) { 1042 list_del(&e->list); 1043 free_entry(e); 1044 } 1045 } 1046 1047 /* Initiate an SCTP association. 1048 This is a special case of send_to_sock() in that we don't yet have a 1049 peeled-off socket for this association, so we use the listening socket 1050 and add the primary IP address of the remote node. 1051 */ 1052 static void sctp_init_assoc(struct connection *con) 1053 { 1054 struct sockaddr_storage rem_addr; 1055 char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 1056 struct msghdr outmessage; 1057 struct cmsghdr *cmsg; 1058 struct sctp_sndrcvinfo *sinfo; 1059 struct connection *base_con; 1060 struct writequeue_entry *e; 1061 int len, offset; 1062 int ret; 1063 int addrlen; 1064 struct kvec iov[1]; 1065 1066 mutex_lock(&con->sock_mutex); 1067 if (test_and_set_bit(CF_INIT_PENDING, &con->flags)) 1068 goto unlock; 1069 1070 if (nodeid_to_addr(con->nodeid, NULL, (struct sockaddr *)&rem_addr, 1071 con->try_new_addr)) { 1072 log_print("no address for nodeid %d", con->nodeid); 1073 goto unlock; 1074 } 1075 base_con = nodeid2con(0, 0); 1076 BUG_ON(base_con == NULL); 1077 1078 make_sockaddr(&rem_addr, dlm_config.ci_tcp_port, &addrlen); 1079 1080 outmessage.msg_name = &rem_addr; 1081 outmessage.msg_namelen = addrlen; 1082 outmessage.msg_control = outcmsg; 1083 outmessage.msg_controllen = sizeof(outcmsg); 1084 outmessage.msg_flags = MSG_EOR; 1085 1086 spin_lock(&con->writequeue_lock); 1087 1088 if (list_empty(&con->writequeue)) { 1089 spin_unlock(&con->writequeue_lock); 1090 log_print("writequeue empty for nodeid %d", con->nodeid); 1091 goto unlock; 1092 } 1093 1094 e = list_first_entry(&con->writequeue, struct writequeue_entry, list); 1095 len = e->len; 1096 offset = e->offset; 1097 1098 /* Send the first block off the write queue */ 1099 iov[0].iov_base = page_address(e->page)+offset; 1100 iov[0].iov_len = len; 1101 spin_unlock(&con->writequeue_lock); 1102 1103 if (rem_addr.ss_family == AF_INET) { 1104 struct sockaddr_in *sin = (struct sockaddr_in *)&rem_addr; 1105 log_print("Trying to connect to %pI4", &sin->sin_addr.s_addr); 1106 } else { 1107 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&rem_addr; 1108 log_print("Trying to connect to %pI6", &sin6->sin6_addr); 1109 } 1110 1111 cmsg = CMSG_FIRSTHDR(&outmessage); 1112 cmsg->cmsg_level = IPPROTO_SCTP; 1113 cmsg->cmsg_type = SCTP_SNDRCV; 1114 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo)); 1115 sinfo = CMSG_DATA(cmsg); 1116 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo)); 1117 sinfo->sinfo_ppid = cpu_to_le32(con->nodeid); 1118 outmessage.msg_controllen = cmsg->cmsg_len; 1119 sinfo->sinfo_flags |= SCTP_ADDR_OVER; 1120 1121 ret = kernel_sendmsg(base_con->sock, &outmessage, iov, 1, len); 1122 if (ret < 0) { 1123 log_print("Send first packet to node %d failed: %d", 1124 con->nodeid, ret); 1125 1126 /* Try again later */ 1127 clear_bit(CF_CONNECT_PENDING, &con->flags); 1128 clear_bit(CF_INIT_PENDING, &con->flags); 1129 } 1130 else { 1131 spin_lock(&con->writequeue_lock); 1132 writequeue_entry_complete(e, ret); 1133 spin_unlock(&con->writequeue_lock); 1134 } 1135 1136 unlock: 1137 mutex_unlock(&con->sock_mutex); 1138 } 1139 1140 /* Connect a new socket to its peer */ 1141 static void tcp_connect_to_sock(struct connection *con) 1142 { 1143 struct sockaddr_storage saddr, src_addr; 1144 int addr_len; 1145 struct socket *sock = NULL; 1146 int one = 1; 1147 int result; 1148 1149 if (con->nodeid == 0) { 1150 log_print("attempt to connect sock 0 foiled"); 1151 return; 1152 } 1153 1154 mutex_lock(&con->sock_mutex); 1155 if (con->retries++ > MAX_CONNECT_RETRIES) 1156 goto out; 1157 1158 /* Some odd races can cause double-connects, ignore them */ 1159 if (con->sock) 1160 goto out; 1161 1162 /* Create a socket to communicate with */ 1163 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 1164 IPPROTO_TCP, &sock); 1165 if (result < 0) 1166 goto out_err; 1167 1168 memset(&saddr, 0, sizeof(saddr)); 1169 result = nodeid_to_addr(con->nodeid, &saddr, NULL, false); 1170 if (result < 0) { 1171 log_print("no address for nodeid %d", con->nodeid); 1172 goto out_err; 1173 } 1174 1175 sock->sk->sk_user_data = con; 1176 con->rx_action = receive_from_sock; 1177 con->connect_action = tcp_connect_to_sock; 1178 add_sock(sock, con); 1179 1180 /* Bind to our cluster-known address connecting to avoid 1181 routing problems */ 1182 memcpy(&src_addr, dlm_local_addr[0], sizeof(src_addr)); 1183 make_sockaddr(&src_addr, 0, &addr_len); 1184 result = sock->ops->bind(sock, (struct sockaddr *) &src_addr, 1185 addr_len); 1186 if (result < 0) { 1187 log_print("could not bind for connect: %d", result); 1188 /* This *may* not indicate a critical error */ 1189 } 1190 1191 make_sockaddr(&saddr, dlm_config.ci_tcp_port, &addr_len); 1192 1193 log_print("connecting to %d", con->nodeid); 1194 1195 /* Turn off Nagle's algorithm */ 1196 kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY, (char *)&one, 1197 sizeof(one)); 1198 1199 result = sock->ops->connect(sock, (struct sockaddr *)&saddr, addr_len, 1200 O_NONBLOCK); 1201 if (result == -EINPROGRESS) 1202 result = 0; 1203 if (result == 0) 1204 goto out; 1205 1206 out_err: 1207 if (con->sock) { 1208 sock_release(con->sock); 1209 con->sock = NULL; 1210 } else if (sock) { 1211 sock_release(sock); 1212 } 1213 /* 1214 * Some errors are fatal and this list might need adjusting. For other 1215 * errors we try again until the max number of retries is reached. 1216 */ 1217 if (result != -EHOSTUNREACH && 1218 result != -ENETUNREACH && 1219 result != -ENETDOWN && 1220 result != -EINVAL && 1221 result != -EPROTONOSUPPORT) { 1222 log_print("connect %d try %d error %d", con->nodeid, 1223 con->retries, result); 1224 mutex_unlock(&con->sock_mutex); 1225 msleep(1000); 1226 lowcomms_connect_sock(con); 1227 return; 1228 } 1229 out: 1230 mutex_unlock(&con->sock_mutex); 1231 return; 1232 } 1233 1234 static struct socket *tcp_create_listen_sock(struct connection *con, 1235 struct sockaddr_storage *saddr) 1236 { 1237 struct socket *sock = NULL; 1238 int result = 0; 1239 int one = 1; 1240 int addr_len; 1241 1242 if (dlm_local_addr[0]->ss_family == AF_INET) 1243 addr_len = sizeof(struct sockaddr_in); 1244 else 1245 addr_len = sizeof(struct sockaddr_in6); 1246 1247 /* Create a socket to communicate with */ 1248 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 1249 IPPROTO_TCP, &sock); 1250 if (result < 0) { 1251 log_print("Can't create listening comms socket"); 1252 goto create_out; 1253 } 1254 1255 /* Turn off Nagle's algorithm */ 1256 kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY, (char *)&one, 1257 sizeof(one)); 1258 1259 result = kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, 1260 (char *)&one, sizeof(one)); 1261 1262 if (result < 0) { 1263 log_print("Failed to set SO_REUSEADDR on socket: %d", result); 1264 } 1265 con->rx_action = tcp_accept_from_sock; 1266 con->connect_action = tcp_connect_to_sock; 1267 1268 /* Bind to our port */ 1269 make_sockaddr(saddr, dlm_config.ci_tcp_port, &addr_len); 1270 result = sock->ops->bind(sock, (struct sockaddr *) saddr, addr_len); 1271 if (result < 0) { 1272 log_print("Can't bind to port %d", dlm_config.ci_tcp_port); 1273 sock_release(sock); 1274 sock = NULL; 1275 con->sock = NULL; 1276 goto create_out; 1277 } 1278 result = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, 1279 (char *)&one, sizeof(one)); 1280 if (result < 0) { 1281 log_print("Set keepalive failed: %d", result); 1282 } 1283 1284 result = sock->ops->listen(sock, 5); 1285 if (result < 0) { 1286 log_print("Can't listen on port %d", dlm_config.ci_tcp_port); 1287 sock_release(sock); 1288 sock = NULL; 1289 goto create_out; 1290 } 1291 1292 create_out: 1293 return sock; 1294 } 1295 1296 /* Get local addresses */ 1297 static void init_local(void) 1298 { 1299 struct sockaddr_storage sas, *addr; 1300 int i; 1301 1302 dlm_local_count = 0; 1303 for (i = 0; i < DLM_MAX_ADDR_COUNT; i++) { 1304 if (dlm_our_addr(&sas, i)) 1305 break; 1306 1307 addr = kmalloc(sizeof(*addr), GFP_NOFS); 1308 if (!addr) 1309 break; 1310 memcpy(addr, &sas, sizeof(*addr)); 1311 dlm_local_addr[dlm_local_count++] = addr; 1312 } 1313 } 1314 1315 /* Bind to an IP address. SCTP allows multiple address so it can do 1316 multi-homing */ 1317 static int add_sctp_bind_addr(struct connection *sctp_con, 1318 struct sockaddr_storage *addr, 1319 int addr_len, int num) 1320 { 1321 int result = 0; 1322 1323 if (num == 1) 1324 result = kernel_bind(sctp_con->sock, 1325 (struct sockaddr *) addr, 1326 addr_len); 1327 else 1328 result = kernel_setsockopt(sctp_con->sock, SOL_SCTP, 1329 SCTP_SOCKOPT_BINDX_ADD, 1330 (char *)addr, addr_len); 1331 1332 if (result < 0) 1333 log_print("Can't bind to port %d addr number %d", 1334 dlm_config.ci_tcp_port, num); 1335 1336 return result; 1337 } 1338 1339 /* Initialise SCTP socket and bind to all interfaces */ 1340 static int sctp_listen_for_all(void) 1341 { 1342 struct socket *sock = NULL; 1343 struct sockaddr_storage localaddr; 1344 struct sctp_event_subscribe subscribe; 1345 int result = -EINVAL, num = 1, i, addr_len; 1346 struct connection *con = nodeid2con(0, GFP_NOFS); 1347 int bufsize = NEEDED_RMEM; 1348 int one = 1; 1349 1350 if (!con) 1351 return -ENOMEM; 1352 1353 log_print("Using SCTP for communications"); 1354 1355 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_SEQPACKET, 1356 IPPROTO_SCTP, &sock); 1357 if (result < 0) { 1358 log_print("Can't create comms socket, check SCTP is loaded"); 1359 goto out; 1360 } 1361 1362 /* Listen for events */ 1363 memset(&subscribe, 0, sizeof(subscribe)); 1364 subscribe.sctp_data_io_event = 1; 1365 subscribe.sctp_association_event = 1; 1366 subscribe.sctp_send_failure_event = 1; 1367 subscribe.sctp_shutdown_event = 1; 1368 subscribe.sctp_partial_delivery_event = 1; 1369 1370 result = kernel_setsockopt(sock, SOL_SOCKET, SO_RCVBUFFORCE, 1371 (char *)&bufsize, sizeof(bufsize)); 1372 if (result) 1373 log_print("Error increasing buffer space on socket %d", result); 1374 1375 result = kernel_setsockopt(sock, SOL_SCTP, SCTP_EVENTS, 1376 (char *)&subscribe, sizeof(subscribe)); 1377 if (result < 0) { 1378 log_print("Failed to set SCTP_EVENTS on socket: result=%d", 1379 result); 1380 goto create_delsock; 1381 } 1382 1383 result = kernel_setsockopt(sock, SOL_SCTP, SCTP_NODELAY, (char *)&one, 1384 sizeof(one)); 1385 if (result < 0) 1386 log_print("Could not set SCTP NODELAY error %d\n", result); 1387 1388 /* Init con struct */ 1389 sock->sk->sk_user_data = con; 1390 con->sock = sock; 1391 con->sock->sk->sk_data_ready = lowcomms_data_ready; 1392 con->rx_action = receive_from_sock; 1393 con->connect_action = sctp_init_assoc; 1394 1395 /* Bind to all interfaces. */ 1396 for (i = 0; i < dlm_local_count; i++) { 1397 memcpy(&localaddr, dlm_local_addr[i], sizeof(localaddr)); 1398 make_sockaddr(&localaddr, dlm_config.ci_tcp_port, &addr_len); 1399 1400 result = add_sctp_bind_addr(con, &localaddr, addr_len, num); 1401 if (result) 1402 goto create_delsock; 1403 ++num; 1404 } 1405 1406 result = sock->ops->listen(sock, 5); 1407 if (result < 0) { 1408 log_print("Can't set socket listening"); 1409 goto create_delsock; 1410 } 1411 1412 return 0; 1413 1414 create_delsock: 1415 sock_release(sock); 1416 con->sock = NULL; 1417 out: 1418 return result; 1419 } 1420 1421 static int tcp_listen_for_all(void) 1422 { 1423 struct socket *sock = NULL; 1424 struct connection *con = nodeid2con(0, GFP_NOFS); 1425 int result = -EINVAL; 1426 1427 if (!con) 1428 return -ENOMEM; 1429 1430 /* We don't support multi-homed hosts */ 1431 if (dlm_local_addr[1] != NULL) { 1432 log_print("TCP protocol can't handle multi-homed hosts, " 1433 "try SCTP"); 1434 return -EINVAL; 1435 } 1436 1437 log_print("Using TCP for communications"); 1438 1439 sock = tcp_create_listen_sock(con, dlm_local_addr[0]); 1440 if (sock) { 1441 add_sock(sock, con); 1442 result = 0; 1443 } 1444 else { 1445 result = -EADDRINUSE; 1446 } 1447 1448 return result; 1449 } 1450 1451 1452 1453 static struct writequeue_entry *new_writequeue_entry(struct connection *con, 1454 gfp_t allocation) 1455 { 1456 struct writequeue_entry *entry; 1457 1458 entry = kmalloc(sizeof(struct writequeue_entry), allocation); 1459 if (!entry) 1460 return NULL; 1461 1462 entry->page = alloc_page(allocation); 1463 if (!entry->page) { 1464 kfree(entry); 1465 return NULL; 1466 } 1467 1468 entry->offset = 0; 1469 entry->len = 0; 1470 entry->end = 0; 1471 entry->users = 0; 1472 entry->con = con; 1473 1474 return entry; 1475 } 1476 1477 void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc) 1478 { 1479 struct connection *con; 1480 struct writequeue_entry *e; 1481 int offset = 0; 1482 1483 con = nodeid2con(nodeid, allocation); 1484 if (!con) 1485 return NULL; 1486 1487 spin_lock(&con->writequeue_lock); 1488 e = list_entry(con->writequeue.prev, struct writequeue_entry, list); 1489 if ((&e->list == &con->writequeue) || 1490 (PAGE_CACHE_SIZE - e->end < len)) { 1491 e = NULL; 1492 } else { 1493 offset = e->end; 1494 e->end += len; 1495 e->users++; 1496 } 1497 spin_unlock(&con->writequeue_lock); 1498 1499 if (e) { 1500 got_one: 1501 *ppc = page_address(e->page) + offset; 1502 return e; 1503 } 1504 1505 e = new_writequeue_entry(con, allocation); 1506 if (e) { 1507 spin_lock(&con->writequeue_lock); 1508 offset = e->end; 1509 e->end += len; 1510 e->users++; 1511 list_add_tail(&e->list, &con->writequeue); 1512 spin_unlock(&con->writequeue_lock); 1513 goto got_one; 1514 } 1515 return NULL; 1516 } 1517 1518 void dlm_lowcomms_commit_buffer(void *mh) 1519 { 1520 struct writequeue_entry *e = (struct writequeue_entry *)mh; 1521 struct connection *con = e->con; 1522 int users; 1523 1524 spin_lock(&con->writequeue_lock); 1525 users = --e->users; 1526 if (users) 1527 goto out; 1528 e->len = e->end - e->offset; 1529 spin_unlock(&con->writequeue_lock); 1530 1531 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) { 1532 queue_work(send_workqueue, &con->swork); 1533 } 1534 return; 1535 1536 out: 1537 spin_unlock(&con->writequeue_lock); 1538 return; 1539 } 1540 1541 /* Send a message */ 1542 static void send_to_sock(struct connection *con) 1543 { 1544 int ret = 0; 1545 const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL; 1546 struct writequeue_entry *e; 1547 int len, offset; 1548 int count = 0; 1549 1550 mutex_lock(&con->sock_mutex); 1551 if (con->sock == NULL) 1552 goto out_connect; 1553 1554 spin_lock(&con->writequeue_lock); 1555 for (;;) { 1556 e = list_entry(con->writequeue.next, struct writequeue_entry, 1557 list); 1558 if ((struct list_head *) e == &con->writequeue) 1559 break; 1560 1561 len = e->len; 1562 offset = e->offset; 1563 BUG_ON(len == 0 && e->users == 0); 1564 spin_unlock(&con->writequeue_lock); 1565 1566 ret = 0; 1567 if (len) { 1568 ret = kernel_sendpage(con->sock, e->page, offset, len, 1569 msg_flags); 1570 if (ret == -EAGAIN || ret == 0) { 1571 if (ret == -EAGAIN && 1572 test_bit(SOCK_ASYNC_NOSPACE, &con->sock->flags) && 1573 !test_and_set_bit(CF_APP_LIMITED, &con->flags)) { 1574 /* Notify TCP that we're limited by the 1575 * application window size. 1576 */ 1577 set_bit(SOCK_NOSPACE, &con->sock->flags); 1578 con->sock->sk->sk_write_pending++; 1579 } 1580 cond_resched(); 1581 goto out; 1582 } else if (ret < 0) 1583 goto send_error; 1584 } 1585 1586 /* Don't starve people filling buffers */ 1587 if (++count >= MAX_SEND_MSG_COUNT) { 1588 cond_resched(); 1589 count = 0; 1590 } 1591 1592 spin_lock(&con->writequeue_lock); 1593 writequeue_entry_complete(e, ret); 1594 } 1595 spin_unlock(&con->writequeue_lock); 1596 out: 1597 mutex_unlock(&con->sock_mutex); 1598 return; 1599 1600 send_error: 1601 mutex_unlock(&con->sock_mutex); 1602 close_connection(con, false); 1603 lowcomms_connect_sock(con); 1604 return; 1605 1606 out_connect: 1607 mutex_unlock(&con->sock_mutex); 1608 if (!test_bit(CF_INIT_PENDING, &con->flags)) 1609 lowcomms_connect_sock(con); 1610 } 1611 1612 static void clean_one_writequeue(struct connection *con) 1613 { 1614 struct writequeue_entry *e, *safe; 1615 1616 spin_lock(&con->writequeue_lock); 1617 list_for_each_entry_safe(e, safe, &con->writequeue, list) { 1618 list_del(&e->list); 1619 free_entry(e); 1620 } 1621 spin_unlock(&con->writequeue_lock); 1622 } 1623 1624 /* Called from recovery when it knows that a node has 1625 left the cluster */ 1626 int dlm_lowcomms_close(int nodeid) 1627 { 1628 struct connection *con; 1629 struct dlm_node_addr *na; 1630 1631 log_print("closing connection to node %d", nodeid); 1632 con = nodeid2con(nodeid, 0); 1633 if (con) { 1634 clear_bit(CF_CONNECT_PENDING, &con->flags); 1635 clear_bit(CF_WRITE_PENDING, &con->flags); 1636 set_bit(CF_CLOSE, &con->flags); 1637 if (cancel_work_sync(&con->swork)) 1638 log_print("canceled swork for node %d", nodeid); 1639 if (cancel_work_sync(&con->rwork)) 1640 log_print("canceled rwork for node %d", nodeid); 1641 clean_one_writequeue(con); 1642 close_connection(con, true); 1643 } 1644 1645 spin_lock(&dlm_node_addrs_spin); 1646 na = find_node_addr(nodeid); 1647 if (na) { 1648 list_del(&na->list); 1649 while (na->addr_count--) 1650 kfree(na->addr[na->addr_count]); 1651 kfree(na); 1652 } 1653 spin_unlock(&dlm_node_addrs_spin); 1654 1655 return 0; 1656 } 1657 1658 /* Receive workqueue function */ 1659 static void process_recv_sockets(struct work_struct *work) 1660 { 1661 struct connection *con = container_of(work, struct connection, rwork); 1662 int err; 1663 1664 clear_bit(CF_READ_PENDING, &con->flags); 1665 do { 1666 err = con->rx_action(con); 1667 } while (!err); 1668 } 1669 1670 /* Send workqueue function */ 1671 static void process_send_sockets(struct work_struct *work) 1672 { 1673 struct connection *con = container_of(work, struct connection, swork); 1674 1675 if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) { 1676 con->connect_action(con); 1677 set_bit(CF_WRITE_PENDING, &con->flags); 1678 } 1679 if (test_and_clear_bit(CF_WRITE_PENDING, &con->flags)) 1680 send_to_sock(con); 1681 } 1682 1683 1684 /* Discard all entries on the write queues */ 1685 static void clean_writequeues(void) 1686 { 1687 foreach_conn(clean_one_writequeue); 1688 } 1689 1690 static void work_stop(void) 1691 { 1692 destroy_workqueue(recv_workqueue); 1693 destroy_workqueue(send_workqueue); 1694 } 1695 1696 static int work_start(void) 1697 { 1698 recv_workqueue = alloc_workqueue("dlm_recv", 1699 WQ_UNBOUND | WQ_MEM_RECLAIM, 1); 1700 if (!recv_workqueue) { 1701 log_print("can't start dlm_recv"); 1702 return -ENOMEM; 1703 } 1704 1705 send_workqueue = alloc_workqueue("dlm_send", 1706 WQ_UNBOUND | WQ_MEM_RECLAIM, 1); 1707 if (!send_workqueue) { 1708 log_print("can't start dlm_send"); 1709 destroy_workqueue(recv_workqueue); 1710 return -ENOMEM; 1711 } 1712 1713 return 0; 1714 } 1715 1716 static void stop_conn(struct connection *con) 1717 { 1718 con->flags |= 0x0F; 1719 if (con->sock && con->sock->sk) 1720 con->sock->sk->sk_user_data = NULL; 1721 } 1722 1723 static void free_conn(struct connection *con) 1724 { 1725 close_connection(con, true); 1726 if (con->othercon) 1727 kmem_cache_free(con_cache, con->othercon); 1728 hlist_del(&con->list); 1729 kmem_cache_free(con_cache, con); 1730 } 1731 1732 void dlm_lowcomms_stop(void) 1733 { 1734 /* Set all the flags to prevent any 1735 socket activity. 1736 */ 1737 mutex_lock(&connections_lock); 1738 dlm_allow_conn = 0; 1739 foreach_conn(stop_conn); 1740 mutex_unlock(&connections_lock); 1741 1742 work_stop(); 1743 1744 mutex_lock(&connections_lock); 1745 clean_writequeues(); 1746 1747 foreach_conn(free_conn); 1748 1749 mutex_unlock(&connections_lock); 1750 kmem_cache_destroy(con_cache); 1751 } 1752 1753 int dlm_lowcomms_start(void) 1754 { 1755 int error = -EINVAL; 1756 struct connection *con; 1757 int i; 1758 1759 for (i = 0; i < CONN_HASH_SIZE; i++) 1760 INIT_HLIST_HEAD(&connection_hash[i]); 1761 1762 init_local(); 1763 if (!dlm_local_count) { 1764 error = -ENOTCONN; 1765 log_print("no local IP address has been set"); 1766 goto fail; 1767 } 1768 1769 error = -ENOMEM; 1770 con_cache = kmem_cache_create("dlm_conn", sizeof(struct connection), 1771 __alignof__(struct connection), 0, 1772 NULL); 1773 if (!con_cache) 1774 goto fail; 1775 1776 error = work_start(); 1777 if (error) 1778 goto fail_destroy; 1779 1780 dlm_allow_conn = 1; 1781 1782 /* Start listening */ 1783 if (dlm_config.ci_protocol == 0) 1784 error = tcp_listen_for_all(); 1785 else 1786 error = sctp_listen_for_all(); 1787 if (error) 1788 goto fail_unlisten; 1789 1790 return 0; 1791 1792 fail_unlisten: 1793 dlm_allow_conn = 0; 1794 con = nodeid2con(0,0); 1795 if (con) { 1796 close_connection(con, false); 1797 kmem_cache_free(con_cache, con); 1798 } 1799 fail_destroy: 1800 kmem_cache_destroy(con_cache); 1801 fail: 1802 return error; 1803 } 1804 1805 void dlm_lowcomms_exit(void) 1806 { 1807 struct dlm_node_addr *na, *safe; 1808 1809 spin_lock(&dlm_node_addrs_spin); 1810 list_for_each_entry_safe(na, safe, &dlm_node_addrs, list) { 1811 list_del(&na->list); 1812 while (na->addr_count--) 1813 kfree(na->addr[na->addr_count]); 1814 kfree(na); 1815 } 1816 spin_unlock(&dlm_node_addrs_spin); 1817 } 1818