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 <linux/sctp.h> 56 #include <net/sctp/sctp.h> 57 #include <net/ipv6.h> 58 59 #include "dlm_internal.h" 60 #include "lowcomms.h" 61 #include "midcomms.h" 62 #include "config.h" 63 64 #define NEEDED_RMEM (4*1024*1024) 65 #define CONN_HASH_SIZE 32 66 67 /* Number of messages to send before rescheduling */ 68 #define MAX_SEND_MSG_COUNT 25 69 70 struct cbuf { 71 unsigned int base; 72 unsigned int len; 73 unsigned int mask; 74 }; 75 76 static void cbuf_add(struct cbuf *cb, int n) 77 { 78 cb->len += n; 79 } 80 81 static int cbuf_data(struct cbuf *cb) 82 { 83 return ((cb->base + cb->len) & cb->mask); 84 } 85 86 static void cbuf_init(struct cbuf *cb, int size) 87 { 88 cb->base = cb->len = 0; 89 cb->mask = size-1; 90 } 91 92 static void cbuf_eat(struct cbuf *cb, int n) 93 { 94 cb->len -= n; 95 cb->base += n; 96 cb->base &= cb->mask; 97 } 98 99 static bool cbuf_empty(struct cbuf *cb) 100 { 101 return cb->len == 0; 102 } 103 104 struct connection { 105 struct socket *sock; /* NULL if not connected */ 106 uint32_t nodeid; /* So we know who we are in the list */ 107 struct mutex sock_mutex; 108 unsigned long flags; 109 #define CF_READ_PENDING 1 110 #define CF_WRITE_PENDING 2 111 #define CF_CONNECT_PENDING 3 112 #define CF_INIT_PENDING 4 113 #define CF_IS_OTHERCON 5 114 #define CF_CLOSE 6 115 #define CF_APP_LIMITED 7 116 struct list_head writequeue; /* List of outgoing writequeue_entries */ 117 spinlock_t writequeue_lock; 118 int (*rx_action) (struct connection *); /* What to do when active */ 119 void (*connect_action) (struct connection *); /* What to do to connect */ 120 struct page *rx_page; 121 struct cbuf cb; 122 int retries; 123 #define MAX_CONNECT_RETRIES 3 124 int sctp_assoc; 125 struct hlist_node list; 126 struct connection *othercon; 127 struct work_struct rwork; /* Receive workqueue */ 128 struct work_struct swork; /* Send workqueue */ 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 struct sockaddr_storage *addr[DLM_MAX_ADDR_COUNT]; 148 }; 149 150 static LIST_HEAD(dlm_node_addrs); 151 static DEFINE_SPINLOCK(dlm_node_addrs_spin); 152 153 static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT]; 154 static int dlm_local_count; 155 static int dlm_allow_conn; 156 157 /* Work queues */ 158 static struct workqueue_struct *recv_workqueue; 159 static struct workqueue_struct *send_workqueue; 160 161 static struct hlist_head connection_hash[CONN_HASH_SIZE]; 162 static DEFINE_MUTEX(connections_lock); 163 static struct kmem_cache *con_cache; 164 165 static void process_recv_sockets(struct work_struct *work); 166 static void process_send_sockets(struct work_struct *work); 167 168 169 /* This is deliberately very simple because most clusters have simple 170 sequential nodeids, so we should be able to go straight to a connection 171 struct in the array */ 172 static inline int nodeid_hash(int nodeid) 173 { 174 return nodeid & (CONN_HASH_SIZE-1); 175 } 176 177 static struct connection *__find_con(int nodeid) 178 { 179 int r; 180 struct connection *con; 181 182 r = nodeid_hash(nodeid); 183 184 hlist_for_each_entry(con, &connection_hash[r], list) { 185 if (con->nodeid == nodeid) 186 return con; 187 } 188 return NULL; 189 } 190 191 /* 192 * If 'allocation' is zero then we don't attempt to create a new 193 * connection structure for this node. 194 */ 195 static struct connection *__nodeid2con(int nodeid, gfp_t alloc) 196 { 197 struct connection *con = NULL; 198 int r; 199 200 con = __find_con(nodeid); 201 if (con || !alloc) 202 return con; 203 204 con = kmem_cache_zalloc(con_cache, alloc); 205 if (!con) 206 return NULL; 207 208 r = nodeid_hash(nodeid); 209 hlist_add_head(&con->list, &connection_hash[r]); 210 211 con->nodeid = nodeid; 212 mutex_init(&con->sock_mutex); 213 INIT_LIST_HEAD(&con->writequeue); 214 spin_lock_init(&con->writequeue_lock); 215 INIT_WORK(&con->swork, process_send_sockets); 216 INIT_WORK(&con->rwork, process_recv_sockets); 217 218 /* Setup action pointers for child sockets */ 219 if (con->nodeid) { 220 struct connection *zerocon = __find_con(0); 221 222 con->connect_action = zerocon->connect_action; 223 if (!con->rx_action) 224 con->rx_action = zerocon->rx_action; 225 } 226 227 return con; 228 } 229 230 /* Loop round all connections */ 231 static void foreach_conn(void (*conn_func)(struct connection *c)) 232 { 233 int i; 234 struct hlist_node *n; 235 struct connection *con; 236 237 for (i = 0; i < CONN_HASH_SIZE; i++) { 238 hlist_for_each_entry_safe(con, n, &connection_hash[i], list) 239 conn_func(con); 240 } 241 } 242 243 static struct connection *nodeid2con(int nodeid, gfp_t allocation) 244 { 245 struct connection *con; 246 247 mutex_lock(&connections_lock); 248 con = __nodeid2con(nodeid, allocation); 249 mutex_unlock(&connections_lock); 250 251 return con; 252 } 253 254 /* This is a bit drastic, but only called when things go wrong */ 255 static struct connection *assoc2con(int assoc_id) 256 { 257 int i; 258 struct connection *con; 259 260 mutex_lock(&connections_lock); 261 262 for (i = 0 ; i < CONN_HASH_SIZE; i++) { 263 hlist_for_each_entry(con, &connection_hash[i], list) { 264 if (con->sctp_assoc == assoc_id) { 265 mutex_unlock(&connections_lock); 266 return con; 267 } 268 } 269 } 270 mutex_unlock(&connections_lock); 271 return NULL; 272 } 273 274 static struct dlm_node_addr *find_node_addr(int nodeid) 275 { 276 struct dlm_node_addr *na; 277 278 list_for_each_entry(na, &dlm_node_addrs, list) { 279 if (na->nodeid == nodeid) 280 return na; 281 } 282 return NULL; 283 } 284 285 static int addr_compare(struct sockaddr_storage *x, struct sockaddr_storage *y) 286 { 287 switch (x->ss_family) { 288 case AF_INET: { 289 struct sockaddr_in *sinx = (struct sockaddr_in *)x; 290 struct sockaddr_in *siny = (struct sockaddr_in *)y; 291 if (sinx->sin_addr.s_addr != siny->sin_addr.s_addr) 292 return 0; 293 if (sinx->sin_port != siny->sin_port) 294 return 0; 295 break; 296 } 297 case AF_INET6: { 298 struct sockaddr_in6 *sinx = (struct sockaddr_in6 *)x; 299 struct sockaddr_in6 *siny = (struct sockaddr_in6 *)y; 300 if (!ipv6_addr_equal(&sinx->sin6_addr, &siny->sin6_addr)) 301 return 0; 302 if (sinx->sin6_port != siny->sin6_port) 303 return 0; 304 break; 305 } 306 default: 307 return 0; 308 } 309 return 1; 310 } 311 312 static int nodeid_to_addr(int nodeid, struct sockaddr_storage *sas_out, 313 struct sockaddr *sa_out) 314 { 315 struct sockaddr_storage sas; 316 struct dlm_node_addr *na; 317 318 if (!dlm_local_count) 319 return -1; 320 321 spin_lock(&dlm_node_addrs_spin); 322 na = find_node_addr(nodeid); 323 if (na && na->addr_count) 324 memcpy(&sas, na->addr[0], sizeof(struct sockaddr_storage)); 325 spin_unlock(&dlm_node_addrs_spin); 326 327 if (!na) 328 return -EEXIST; 329 330 if (!na->addr_count) 331 return -ENOENT; 332 333 if (sas_out) 334 memcpy(sas_out, &sas, sizeof(struct sockaddr_storage)); 335 336 if (!sa_out) 337 return 0; 338 339 if (dlm_local_addr[0]->ss_family == AF_INET) { 340 struct sockaddr_in *in4 = (struct sockaddr_in *) &sas; 341 struct sockaddr_in *ret4 = (struct sockaddr_in *) sa_out; 342 ret4->sin_addr.s_addr = in4->sin_addr.s_addr; 343 } else { 344 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) &sas; 345 struct sockaddr_in6 *ret6 = (struct sockaddr_in6 *) sa_out; 346 ret6->sin6_addr = in6->sin6_addr; 347 } 348 349 return 0; 350 } 351 352 static int addr_to_nodeid(struct sockaddr_storage *addr, int *nodeid) 353 { 354 struct dlm_node_addr *na; 355 int rv = -EEXIST; 356 357 spin_lock(&dlm_node_addrs_spin); 358 list_for_each_entry(na, &dlm_node_addrs, list) { 359 if (!na->addr_count) 360 continue; 361 362 if (!addr_compare(na->addr[0], addr)) 363 continue; 364 365 *nodeid = na->nodeid; 366 rv = 0; 367 break; 368 } 369 spin_unlock(&dlm_node_addrs_spin); 370 return rv; 371 } 372 373 int dlm_lowcomms_addr(int nodeid, struct sockaddr_storage *addr, int len) 374 { 375 struct sockaddr_storage *new_addr; 376 struct dlm_node_addr *new_node, *na; 377 378 new_node = kzalloc(sizeof(struct dlm_node_addr), GFP_NOFS); 379 if (!new_node) 380 return -ENOMEM; 381 382 new_addr = kzalloc(sizeof(struct sockaddr_storage), GFP_NOFS); 383 if (!new_addr) { 384 kfree(new_node); 385 return -ENOMEM; 386 } 387 388 memcpy(new_addr, addr, len); 389 390 spin_lock(&dlm_node_addrs_spin); 391 na = find_node_addr(nodeid); 392 if (!na) { 393 new_node->nodeid = nodeid; 394 new_node->addr[0] = new_addr; 395 new_node->addr_count = 1; 396 list_add(&new_node->list, &dlm_node_addrs); 397 spin_unlock(&dlm_node_addrs_spin); 398 return 0; 399 } 400 401 if (na->addr_count >= DLM_MAX_ADDR_COUNT) { 402 spin_unlock(&dlm_node_addrs_spin); 403 kfree(new_addr); 404 kfree(new_node); 405 return -ENOSPC; 406 } 407 408 na->addr[na->addr_count++] = new_addr; 409 spin_unlock(&dlm_node_addrs_spin); 410 kfree(new_node); 411 return 0; 412 } 413 414 /* Data available on socket or listen socket received a connect */ 415 static void lowcomms_data_ready(struct sock *sk, int count_unused) 416 { 417 struct connection *con = sock2con(sk); 418 if (con && !test_and_set_bit(CF_READ_PENDING, &con->flags)) 419 queue_work(recv_workqueue, &con->rwork); 420 } 421 422 static void lowcomms_write_space(struct sock *sk) 423 { 424 struct connection *con = sock2con(sk); 425 426 if (!con) 427 return; 428 429 clear_bit(SOCK_NOSPACE, &con->sock->flags); 430 431 if (test_and_clear_bit(CF_APP_LIMITED, &con->flags)) { 432 con->sock->sk->sk_write_pending--; 433 clear_bit(SOCK_ASYNC_NOSPACE, &con->sock->flags); 434 } 435 436 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) 437 queue_work(send_workqueue, &con->swork); 438 } 439 440 static inline void lowcomms_connect_sock(struct connection *con) 441 { 442 if (test_bit(CF_CLOSE, &con->flags)) 443 return; 444 if (!test_and_set_bit(CF_CONNECT_PENDING, &con->flags)) 445 queue_work(send_workqueue, &con->swork); 446 } 447 448 static void lowcomms_state_change(struct sock *sk) 449 { 450 if (sk->sk_state == TCP_ESTABLISHED) 451 lowcomms_write_space(sk); 452 } 453 454 int dlm_lowcomms_connect_node(int nodeid) 455 { 456 struct connection *con; 457 458 /* with sctp there's no connecting without sending */ 459 if (dlm_config.ci_protocol != 0) 460 return 0; 461 462 if (nodeid == dlm_our_nodeid()) 463 return 0; 464 465 con = nodeid2con(nodeid, GFP_NOFS); 466 if (!con) 467 return -ENOMEM; 468 lowcomms_connect_sock(con); 469 return 0; 470 } 471 472 /* Make a socket active */ 473 static void add_sock(struct socket *sock, struct connection *con) 474 { 475 con->sock = sock; 476 477 /* Install a data_ready callback */ 478 con->sock->sk->sk_data_ready = lowcomms_data_ready; 479 con->sock->sk->sk_write_space = lowcomms_write_space; 480 con->sock->sk->sk_state_change = lowcomms_state_change; 481 con->sock->sk->sk_user_data = con; 482 con->sock->sk->sk_allocation = GFP_NOFS; 483 } 484 485 /* Add the port number to an IPv6 or 4 sockaddr and return the address 486 length */ 487 static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port, 488 int *addr_len) 489 { 490 saddr->ss_family = dlm_local_addr[0]->ss_family; 491 if (saddr->ss_family == AF_INET) { 492 struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr; 493 in4_addr->sin_port = cpu_to_be16(port); 494 *addr_len = sizeof(struct sockaddr_in); 495 memset(&in4_addr->sin_zero, 0, sizeof(in4_addr->sin_zero)); 496 } else { 497 struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr; 498 in6_addr->sin6_port = cpu_to_be16(port); 499 *addr_len = sizeof(struct sockaddr_in6); 500 } 501 memset((char *)saddr + *addr_len, 0, sizeof(struct sockaddr_storage) - *addr_len); 502 } 503 504 /* Close a remote connection and tidy up */ 505 static void close_connection(struct connection *con, bool and_other) 506 { 507 mutex_lock(&con->sock_mutex); 508 509 if (con->sock) { 510 sock_release(con->sock); 511 con->sock = NULL; 512 } 513 if (con->othercon && and_other) { 514 /* Will only re-enter once. */ 515 close_connection(con->othercon, false); 516 } 517 if (con->rx_page) { 518 __free_page(con->rx_page); 519 con->rx_page = NULL; 520 } 521 522 con->retries = 0; 523 mutex_unlock(&con->sock_mutex); 524 } 525 526 /* We only send shutdown messages to nodes that are not part of the cluster */ 527 static void sctp_send_shutdown(sctp_assoc_t associd) 528 { 529 static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 530 struct msghdr outmessage; 531 struct cmsghdr *cmsg; 532 struct sctp_sndrcvinfo *sinfo; 533 int ret; 534 struct connection *con; 535 536 con = nodeid2con(0,0); 537 BUG_ON(con == NULL); 538 539 outmessage.msg_name = NULL; 540 outmessage.msg_namelen = 0; 541 outmessage.msg_control = outcmsg; 542 outmessage.msg_controllen = sizeof(outcmsg); 543 outmessage.msg_flags = MSG_EOR; 544 545 cmsg = CMSG_FIRSTHDR(&outmessage); 546 cmsg->cmsg_level = IPPROTO_SCTP; 547 cmsg->cmsg_type = SCTP_SNDRCV; 548 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo)); 549 outmessage.msg_controllen = cmsg->cmsg_len; 550 sinfo = CMSG_DATA(cmsg); 551 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo)); 552 553 sinfo->sinfo_flags |= MSG_EOF; 554 sinfo->sinfo_assoc_id = associd; 555 556 ret = kernel_sendmsg(con->sock, &outmessage, NULL, 0, 0); 557 558 if (ret != 0) 559 log_print("send EOF to node failed: %d", ret); 560 } 561 562 static void sctp_init_failed_foreach(struct connection *con) 563 { 564 con->sctp_assoc = 0; 565 if (test_and_clear_bit(CF_INIT_PENDING, &con->flags)) { 566 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) 567 queue_work(send_workqueue, &con->swork); 568 } 569 } 570 571 /* INIT failed but we don't know which node... 572 restart INIT on all pending nodes */ 573 static void sctp_init_failed(void) 574 { 575 mutex_lock(&connections_lock); 576 577 foreach_conn(sctp_init_failed_foreach); 578 579 mutex_unlock(&connections_lock); 580 } 581 582 /* Something happened to an association */ 583 static void process_sctp_notification(struct connection *con, 584 struct msghdr *msg, char *buf) 585 { 586 union sctp_notification *sn = (union sctp_notification *)buf; 587 588 if (sn->sn_header.sn_type == SCTP_ASSOC_CHANGE) { 589 switch (sn->sn_assoc_change.sac_state) { 590 591 case SCTP_COMM_UP: 592 case SCTP_RESTART: 593 { 594 /* Check that the new node is in the lockspace */ 595 struct sctp_prim prim; 596 int nodeid; 597 int prim_len, ret; 598 int addr_len; 599 struct connection *new_con; 600 601 /* 602 * We get this before any data for an association. 603 * We verify that the node is in the cluster and 604 * then peel off a socket for it. 605 */ 606 if ((int)sn->sn_assoc_change.sac_assoc_id <= 0) { 607 log_print("COMM_UP for invalid assoc ID %d", 608 (int)sn->sn_assoc_change.sac_assoc_id); 609 sctp_init_failed(); 610 return; 611 } 612 memset(&prim, 0, sizeof(struct sctp_prim)); 613 prim_len = sizeof(struct sctp_prim); 614 prim.ssp_assoc_id = sn->sn_assoc_change.sac_assoc_id; 615 616 ret = kernel_getsockopt(con->sock, 617 IPPROTO_SCTP, 618 SCTP_PRIMARY_ADDR, 619 (char*)&prim, 620 &prim_len); 621 if (ret < 0) { 622 log_print("getsockopt/sctp_primary_addr on " 623 "new assoc %d failed : %d", 624 (int)sn->sn_assoc_change.sac_assoc_id, 625 ret); 626 627 /* Retry INIT later */ 628 new_con = assoc2con(sn->sn_assoc_change.sac_assoc_id); 629 if (new_con) 630 clear_bit(CF_CONNECT_PENDING, &con->flags); 631 return; 632 } 633 make_sockaddr(&prim.ssp_addr, 0, &addr_len); 634 if (addr_to_nodeid(&prim.ssp_addr, &nodeid)) { 635 unsigned char *b=(unsigned char *)&prim.ssp_addr; 636 log_print("reject connect from unknown addr"); 637 print_hex_dump_bytes("ss: ", DUMP_PREFIX_NONE, 638 b, sizeof(struct sockaddr_storage)); 639 sctp_send_shutdown(prim.ssp_assoc_id); 640 return; 641 } 642 643 new_con = nodeid2con(nodeid, GFP_NOFS); 644 if (!new_con) 645 return; 646 647 /* Peel off a new sock */ 648 sctp_lock_sock(con->sock->sk); 649 ret = sctp_do_peeloff(con->sock->sk, 650 sn->sn_assoc_change.sac_assoc_id, 651 &new_con->sock); 652 sctp_release_sock(con->sock->sk); 653 if (ret < 0) { 654 log_print("Can't peel off a socket for " 655 "connection %d to node %d: err=%d", 656 (int)sn->sn_assoc_change.sac_assoc_id, 657 nodeid, ret); 658 return; 659 } 660 add_sock(new_con->sock, new_con); 661 662 log_print("connecting to %d sctp association %d", 663 nodeid, (int)sn->sn_assoc_change.sac_assoc_id); 664 665 new_con->sctp_assoc = sn->sn_assoc_change.sac_assoc_id; 666 /* Send any pending writes */ 667 clear_bit(CF_CONNECT_PENDING, &new_con->flags); 668 clear_bit(CF_INIT_PENDING, &new_con->flags); 669 if (!test_and_set_bit(CF_WRITE_PENDING, &new_con->flags)) { 670 queue_work(send_workqueue, &new_con->swork); 671 } 672 if (!test_and_set_bit(CF_READ_PENDING, &new_con->flags)) 673 queue_work(recv_workqueue, &new_con->rwork); 674 } 675 break; 676 677 case SCTP_COMM_LOST: 678 case SCTP_SHUTDOWN_COMP: 679 { 680 con = assoc2con(sn->sn_assoc_change.sac_assoc_id); 681 if (con) { 682 con->sctp_assoc = 0; 683 } 684 } 685 break; 686 687 /* We don't know which INIT failed, so clear the PENDING flags 688 * on them all. if assoc_id is zero then it will then try 689 * again */ 690 691 case SCTP_CANT_STR_ASSOC: 692 { 693 log_print("Can't start SCTP association - retrying"); 694 sctp_init_failed(); 695 } 696 break; 697 698 default: 699 log_print("unexpected SCTP assoc change id=%d state=%d", 700 (int)sn->sn_assoc_change.sac_assoc_id, 701 sn->sn_assoc_change.sac_state); 702 } 703 } 704 } 705 706 /* Data received from remote end */ 707 static int receive_from_sock(struct connection *con) 708 { 709 int ret = 0; 710 struct msghdr msg = {}; 711 struct kvec iov[2]; 712 unsigned len; 713 int r; 714 int call_again_soon = 0; 715 int nvec; 716 char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 717 718 mutex_lock(&con->sock_mutex); 719 720 if (con->sock == NULL) { 721 ret = -EAGAIN; 722 goto out_close; 723 } 724 725 if (con->rx_page == NULL) { 726 /* 727 * This doesn't need to be atomic, but I think it should 728 * improve performance if it is. 729 */ 730 con->rx_page = alloc_page(GFP_ATOMIC); 731 if (con->rx_page == NULL) 732 goto out_resched; 733 cbuf_init(&con->cb, PAGE_CACHE_SIZE); 734 } 735 736 /* Only SCTP needs these really */ 737 memset(&incmsg, 0, sizeof(incmsg)); 738 msg.msg_control = incmsg; 739 msg.msg_controllen = sizeof(incmsg); 740 741 /* 742 * iov[0] is the bit of the circular buffer between the current end 743 * point (cb.base + cb.len) and the end of the buffer. 744 */ 745 iov[0].iov_len = con->cb.base - cbuf_data(&con->cb); 746 iov[0].iov_base = page_address(con->rx_page) + cbuf_data(&con->cb); 747 iov[1].iov_len = 0; 748 nvec = 1; 749 750 /* 751 * iov[1] is the bit of the circular buffer between the start of the 752 * buffer and the start of the currently used section (cb.base) 753 */ 754 if (cbuf_data(&con->cb) >= con->cb.base) { 755 iov[0].iov_len = PAGE_CACHE_SIZE - cbuf_data(&con->cb); 756 iov[1].iov_len = con->cb.base; 757 iov[1].iov_base = page_address(con->rx_page); 758 nvec = 2; 759 } 760 len = iov[0].iov_len + iov[1].iov_len; 761 762 r = ret = kernel_recvmsg(con->sock, &msg, iov, nvec, len, 763 MSG_DONTWAIT | MSG_NOSIGNAL); 764 if (ret <= 0) 765 goto out_close; 766 767 /* Process SCTP notifications */ 768 if (msg.msg_flags & MSG_NOTIFICATION) { 769 msg.msg_control = incmsg; 770 msg.msg_controllen = sizeof(incmsg); 771 772 process_sctp_notification(con, &msg, 773 page_address(con->rx_page) + con->cb.base); 774 mutex_unlock(&con->sock_mutex); 775 return 0; 776 } 777 BUG_ON(con->nodeid == 0); 778 779 if (ret == len) 780 call_again_soon = 1; 781 cbuf_add(&con->cb, ret); 782 ret = dlm_process_incoming_buffer(con->nodeid, 783 page_address(con->rx_page), 784 con->cb.base, con->cb.len, 785 PAGE_CACHE_SIZE); 786 if (ret == -EBADMSG) { 787 log_print("lowcomms: addr=%p, base=%u, len=%u, " 788 "iov_len=%u, iov_base[0]=%p, read=%d", 789 page_address(con->rx_page), con->cb.base, con->cb.len, 790 len, iov[0].iov_base, r); 791 } 792 if (ret < 0) 793 goto out_close; 794 cbuf_eat(&con->cb, ret); 795 796 if (cbuf_empty(&con->cb) && !call_again_soon) { 797 __free_page(con->rx_page); 798 con->rx_page = NULL; 799 } 800 801 if (call_again_soon) 802 goto out_resched; 803 mutex_unlock(&con->sock_mutex); 804 return 0; 805 806 out_resched: 807 if (!test_and_set_bit(CF_READ_PENDING, &con->flags)) 808 queue_work(recv_workqueue, &con->rwork); 809 mutex_unlock(&con->sock_mutex); 810 return -EAGAIN; 811 812 out_close: 813 mutex_unlock(&con->sock_mutex); 814 if (ret != -EAGAIN) { 815 close_connection(con, false); 816 /* Reconnect when there is something to send */ 817 } 818 /* Don't return success if we really got EOF */ 819 if (ret == 0) 820 ret = -EAGAIN; 821 822 return ret; 823 } 824 825 /* Listening socket is busy, accept a connection */ 826 static int tcp_accept_from_sock(struct connection *con) 827 { 828 int result; 829 struct sockaddr_storage peeraddr; 830 struct socket *newsock; 831 int len; 832 int nodeid; 833 struct connection *newcon; 834 struct connection *addcon; 835 836 mutex_lock(&connections_lock); 837 if (!dlm_allow_conn) { 838 mutex_unlock(&connections_lock); 839 return -1; 840 } 841 mutex_unlock(&connections_lock); 842 843 memset(&peeraddr, 0, sizeof(peeraddr)); 844 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 845 IPPROTO_TCP, &newsock); 846 if (result < 0) 847 return -ENOMEM; 848 849 mutex_lock_nested(&con->sock_mutex, 0); 850 851 result = -ENOTCONN; 852 if (con->sock == NULL) 853 goto accept_err; 854 855 newsock->type = con->sock->type; 856 newsock->ops = con->sock->ops; 857 858 result = con->sock->ops->accept(con->sock, newsock, O_NONBLOCK); 859 if (result < 0) 860 goto accept_err; 861 862 /* Get the connected socket's peer */ 863 memset(&peeraddr, 0, sizeof(peeraddr)); 864 if (newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr, 865 &len, 2)) { 866 result = -ECONNABORTED; 867 goto accept_err; 868 } 869 870 /* Get the new node's NODEID */ 871 make_sockaddr(&peeraddr, 0, &len); 872 if (addr_to_nodeid(&peeraddr, &nodeid)) { 873 unsigned char *b=(unsigned char *)&peeraddr; 874 log_print("connect from non cluster node"); 875 print_hex_dump_bytes("ss: ", DUMP_PREFIX_NONE, 876 b, sizeof(struct sockaddr_storage)); 877 sock_release(newsock); 878 mutex_unlock(&con->sock_mutex); 879 return -1; 880 } 881 882 log_print("got connection from %d", nodeid); 883 884 /* Check to see if we already have a connection to this node. This 885 * could happen if the two nodes initiate a connection at roughly 886 * the same time and the connections cross on the wire. 887 * In this case we store the incoming one in "othercon" 888 */ 889 newcon = nodeid2con(nodeid, GFP_NOFS); 890 if (!newcon) { 891 result = -ENOMEM; 892 goto accept_err; 893 } 894 mutex_lock_nested(&newcon->sock_mutex, 1); 895 if (newcon->sock) { 896 struct connection *othercon = newcon->othercon; 897 898 if (!othercon) { 899 othercon = kmem_cache_zalloc(con_cache, GFP_NOFS); 900 if (!othercon) { 901 log_print("failed to allocate incoming socket"); 902 mutex_unlock(&newcon->sock_mutex); 903 result = -ENOMEM; 904 goto accept_err; 905 } 906 othercon->nodeid = nodeid; 907 othercon->rx_action = receive_from_sock; 908 mutex_init(&othercon->sock_mutex); 909 INIT_WORK(&othercon->swork, process_send_sockets); 910 INIT_WORK(&othercon->rwork, process_recv_sockets); 911 set_bit(CF_IS_OTHERCON, &othercon->flags); 912 } 913 if (!othercon->sock) { 914 newcon->othercon = othercon; 915 othercon->sock = newsock; 916 newsock->sk->sk_user_data = othercon; 917 add_sock(newsock, othercon); 918 addcon = othercon; 919 } 920 else { 921 printk("Extra connection from node %d attempted\n", nodeid); 922 result = -EAGAIN; 923 mutex_unlock(&newcon->sock_mutex); 924 goto accept_err; 925 } 926 } 927 else { 928 newsock->sk->sk_user_data = newcon; 929 newcon->rx_action = receive_from_sock; 930 add_sock(newsock, newcon); 931 addcon = newcon; 932 } 933 934 mutex_unlock(&newcon->sock_mutex); 935 936 /* 937 * Add it to the active queue in case we got data 938 * between processing the accept adding the socket 939 * to the read_sockets list 940 */ 941 if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags)) 942 queue_work(recv_workqueue, &addcon->rwork); 943 mutex_unlock(&con->sock_mutex); 944 945 return 0; 946 947 accept_err: 948 mutex_unlock(&con->sock_mutex); 949 sock_release(newsock); 950 951 if (result != -EAGAIN) 952 log_print("error accepting connection from node: %d", result); 953 return result; 954 } 955 956 static void free_entry(struct writequeue_entry *e) 957 { 958 __free_page(e->page); 959 kfree(e); 960 } 961 962 /* Initiate an SCTP association. 963 This is a special case of send_to_sock() in that we don't yet have a 964 peeled-off socket for this association, so we use the listening socket 965 and add the primary IP address of the remote node. 966 */ 967 static void sctp_init_assoc(struct connection *con) 968 { 969 struct sockaddr_storage rem_addr; 970 char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 971 struct msghdr outmessage; 972 struct cmsghdr *cmsg; 973 struct sctp_sndrcvinfo *sinfo; 974 struct connection *base_con; 975 struct writequeue_entry *e; 976 int len, offset; 977 int ret; 978 int addrlen; 979 struct kvec iov[1]; 980 981 if (test_and_set_bit(CF_INIT_PENDING, &con->flags)) 982 return; 983 984 if (con->retries++ > MAX_CONNECT_RETRIES) 985 return; 986 987 if (nodeid_to_addr(con->nodeid, NULL, (struct sockaddr *)&rem_addr)) { 988 log_print("no address for nodeid %d", con->nodeid); 989 return; 990 } 991 base_con = nodeid2con(0, 0); 992 BUG_ON(base_con == NULL); 993 994 make_sockaddr(&rem_addr, dlm_config.ci_tcp_port, &addrlen); 995 996 outmessage.msg_name = &rem_addr; 997 outmessage.msg_namelen = addrlen; 998 outmessage.msg_control = outcmsg; 999 outmessage.msg_controllen = sizeof(outcmsg); 1000 outmessage.msg_flags = MSG_EOR; 1001 1002 spin_lock(&con->writequeue_lock); 1003 1004 if (list_empty(&con->writequeue)) { 1005 spin_unlock(&con->writequeue_lock); 1006 log_print("writequeue empty for nodeid %d", con->nodeid); 1007 return; 1008 } 1009 1010 e = list_first_entry(&con->writequeue, struct writequeue_entry, list); 1011 len = e->len; 1012 offset = e->offset; 1013 spin_unlock(&con->writequeue_lock); 1014 1015 /* Send the first block off the write queue */ 1016 iov[0].iov_base = page_address(e->page)+offset; 1017 iov[0].iov_len = len; 1018 1019 cmsg = CMSG_FIRSTHDR(&outmessage); 1020 cmsg->cmsg_level = IPPROTO_SCTP; 1021 cmsg->cmsg_type = SCTP_SNDRCV; 1022 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo)); 1023 sinfo = CMSG_DATA(cmsg); 1024 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo)); 1025 sinfo->sinfo_ppid = cpu_to_le32(dlm_our_nodeid()); 1026 outmessage.msg_controllen = cmsg->cmsg_len; 1027 1028 ret = kernel_sendmsg(base_con->sock, &outmessage, iov, 1, len); 1029 if (ret < 0) { 1030 log_print("Send first packet to node %d failed: %d", 1031 con->nodeid, ret); 1032 1033 /* Try again later */ 1034 clear_bit(CF_CONNECT_PENDING, &con->flags); 1035 clear_bit(CF_INIT_PENDING, &con->flags); 1036 } 1037 else { 1038 spin_lock(&con->writequeue_lock); 1039 e->offset += ret; 1040 e->len -= ret; 1041 1042 if (e->len == 0 && e->users == 0) { 1043 list_del(&e->list); 1044 free_entry(e); 1045 } 1046 spin_unlock(&con->writequeue_lock); 1047 } 1048 } 1049 1050 /* Connect a new socket to its peer */ 1051 static void tcp_connect_to_sock(struct connection *con) 1052 { 1053 struct sockaddr_storage saddr, src_addr; 1054 int addr_len; 1055 struct socket *sock = NULL; 1056 int one = 1; 1057 int result; 1058 1059 if (con->nodeid == 0) { 1060 log_print("attempt to connect sock 0 foiled"); 1061 return; 1062 } 1063 1064 mutex_lock(&con->sock_mutex); 1065 if (con->retries++ > MAX_CONNECT_RETRIES) 1066 goto out; 1067 1068 /* Some odd races can cause double-connects, ignore them */ 1069 if (con->sock) 1070 goto out; 1071 1072 /* Create a socket to communicate with */ 1073 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 1074 IPPROTO_TCP, &sock); 1075 if (result < 0) 1076 goto out_err; 1077 1078 memset(&saddr, 0, sizeof(saddr)); 1079 result = nodeid_to_addr(con->nodeid, &saddr, NULL); 1080 if (result < 0) { 1081 log_print("no address for nodeid %d", con->nodeid); 1082 goto out_err; 1083 } 1084 1085 sock->sk->sk_user_data = con; 1086 con->rx_action = receive_from_sock; 1087 con->connect_action = tcp_connect_to_sock; 1088 add_sock(sock, con); 1089 1090 /* Bind to our cluster-known address connecting to avoid 1091 routing problems */ 1092 memcpy(&src_addr, dlm_local_addr[0], sizeof(src_addr)); 1093 make_sockaddr(&src_addr, 0, &addr_len); 1094 result = sock->ops->bind(sock, (struct sockaddr *) &src_addr, 1095 addr_len); 1096 if (result < 0) { 1097 log_print("could not bind for connect: %d", result); 1098 /* This *may* not indicate a critical error */ 1099 } 1100 1101 make_sockaddr(&saddr, dlm_config.ci_tcp_port, &addr_len); 1102 1103 log_print("connecting to %d", con->nodeid); 1104 1105 /* Turn off Nagle's algorithm */ 1106 kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY, (char *)&one, 1107 sizeof(one)); 1108 1109 result = sock->ops->connect(sock, (struct sockaddr *)&saddr, addr_len, 1110 O_NONBLOCK); 1111 if (result == -EINPROGRESS) 1112 result = 0; 1113 if (result == 0) 1114 goto out; 1115 1116 out_err: 1117 if (con->sock) { 1118 sock_release(con->sock); 1119 con->sock = NULL; 1120 } else if (sock) { 1121 sock_release(sock); 1122 } 1123 /* 1124 * Some errors are fatal and this list might need adjusting. For other 1125 * errors we try again until the max number of retries is reached. 1126 */ 1127 if (result != -EHOSTUNREACH && 1128 result != -ENETUNREACH && 1129 result != -ENETDOWN && 1130 result != -EINVAL && 1131 result != -EPROTONOSUPPORT) { 1132 log_print("connect %d try %d error %d", con->nodeid, 1133 con->retries, result); 1134 mutex_unlock(&con->sock_mutex); 1135 msleep(1000); 1136 lowcomms_connect_sock(con); 1137 return; 1138 } 1139 out: 1140 mutex_unlock(&con->sock_mutex); 1141 return; 1142 } 1143 1144 static struct socket *tcp_create_listen_sock(struct connection *con, 1145 struct sockaddr_storage *saddr) 1146 { 1147 struct socket *sock = NULL; 1148 int result = 0; 1149 int one = 1; 1150 int addr_len; 1151 1152 if (dlm_local_addr[0]->ss_family == AF_INET) 1153 addr_len = sizeof(struct sockaddr_in); 1154 else 1155 addr_len = sizeof(struct sockaddr_in6); 1156 1157 /* Create a socket to communicate with */ 1158 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 1159 IPPROTO_TCP, &sock); 1160 if (result < 0) { 1161 log_print("Can't create listening comms socket"); 1162 goto create_out; 1163 } 1164 1165 /* Turn off Nagle's algorithm */ 1166 kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY, (char *)&one, 1167 sizeof(one)); 1168 1169 result = kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, 1170 (char *)&one, sizeof(one)); 1171 1172 if (result < 0) { 1173 log_print("Failed to set SO_REUSEADDR on socket: %d", result); 1174 } 1175 con->rx_action = tcp_accept_from_sock; 1176 con->connect_action = tcp_connect_to_sock; 1177 1178 /* Bind to our port */ 1179 make_sockaddr(saddr, dlm_config.ci_tcp_port, &addr_len); 1180 result = sock->ops->bind(sock, (struct sockaddr *) saddr, addr_len); 1181 if (result < 0) { 1182 log_print("Can't bind to port %d", dlm_config.ci_tcp_port); 1183 sock_release(sock); 1184 sock = NULL; 1185 con->sock = NULL; 1186 goto create_out; 1187 } 1188 result = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, 1189 (char *)&one, sizeof(one)); 1190 if (result < 0) { 1191 log_print("Set keepalive failed: %d", result); 1192 } 1193 1194 result = sock->ops->listen(sock, 5); 1195 if (result < 0) { 1196 log_print("Can't listen on port %d", dlm_config.ci_tcp_port); 1197 sock_release(sock); 1198 sock = NULL; 1199 goto create_out; 1200 } 1201 1202 create_out: 1203 return sock; 1204 } 1205 1206 /* Get local addresses */ 1207 static void init_local(void) 1208 { 1209 struct sockaddr_storage sas, *addr; 1210 int i; 1211 1212 dlm_local_count = 0; 1213 for (i = 0; i < DLM_MAX_ADDR_COUNT; i++) { 1214 if (dlm_our_addr(&sas, i)) 1215 break; 1216 1217 addr = kmalloc(sizeof(*addr), GFP_NOFS); 1218 if (!addr) 1219 break; 1220 memcpy(addr, &sas, sizeof(*addr)); 1221 dlm_local_addr[dlm_local_count++] = addr; 1222 } 1223 } 1224 1225 /* Bind to an IP address. SCTP allows multiple address so it can do 1226 multi-homing */ 1227 static int add_sctp_bind_addr(struct connection *sctp_con, 1228 struct sockaddr_storage *addr, 1229 int addr_len, int num) 1230 { 1231 int result = 0; 1232 1233 if (num == 1) 1234 result = kernel_bind(sctp_con->sock, 1235 (struct sockaddr *) addr, 1236 addr_len); 1237 else 1238 result = kernel_setsockopt(sctp_con->sock, SOL_SCTP, 1239 SCTP_SOCKOPT_BINDX_ADD, 1240 (char *)addr, addr_len); 1241 1242 if (result < 0) 1243 log_print("Can't bind to port %d addr number %d", 1244 dlm_config.ci_tcp_port, num); 1245 1246 return result; 1247 } 1248 1249 /* Initialise SCTP socket and bind to all interfaces */ 1250 static int sctp_listen_for_all(void) 1251 { 1252 struct socket *sock = NULL; 1253 struct sockaddr_storage localaddr; 1254 struct sctp_event_subscribe subscribe; 1255 int result = -EINVAL, num = 1, i, addr_len; 1256 struct connection *con = nodeid2con(0, GFP_NOFS); 1257 int bufsize = NEEDED_RMEM; 1258 1259 if (!con) 1260 return -ENOMEM; 1261 1262 log_print("Using SCTP for communications"); 1263 1264 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_SEQPACKET, 1265 IPPROTO_SCTP, &sock); 1266 if (result < 0) { 1267 log_print("Can't create comms socket, check SCTP is loaded"); 1268 goto out; 1269 } 1270 1271 /* Listen for events */ 1272 memset(&subscribe, 0, sizeof(subscribe)); 1273 subscribe.sctp_data_io_event = 1; 1274 subscribe.sctp_association_event = 1; 1275 subscribe.sctp_send_failure_event = 1; 1276 subscribe.sctp_shutdown_event = 1; 1277 subscribe.sctp_partial_delivery_event = 1; 1278 1279 result = kernel_setsockopt(sock, SOL_SOCKET, SO_RCVBUFFORCE, 1280 (char *)&bufsize, sizeof(bufsize)); 1281 if (result) 1282 log_print("Error increasing buffer space on socket %d", result); 1283 1284 result = kernel_setsockopt(sock, SOL_SCTP, SCTP_EVENTS, 1285 (char *)&subscribe, sizeof(subscribe)); 1286 if (result < 0) { 1287 log_print("Failed to set SCTP_EVENTS on socket: result=%d", 1288 result); 1289 goto create_delsock; 1290 } 1291 1292 /* Init con struct */ 1293 sock->sk->sk_user_data = con; 1294 con->sock = sock; 1295 con->sock->sk->sk_data_ready = lowcomms_data_ready; 1296 con->rx_action = receive_from_sock; 1297 con->connect_action = sctp_init_assoc; 1298 1299 /* Bind to all interfaces. */ 1300 for (i = 0; i < dlm_local_count; i++) { 1301 memcpy(&localaddr, dlm_local_addr[i], sizeof(localaddr)); 1302 make_sockaddr(&localaddr, dlm_config.ci_tcp_port, &addr_len); 1303 1304 result = add_sctp_bind_addr(con, &localaddr, addr_len, num); 1305 if (result) 1306 goto create_delsock; 1307 ++num; 1308 } 1309 1310 result = sock->ops->listen(sock, 5); 1311 if (result < 0) { 1312 log_print("Can't set socket listening"); 1313 goto create_delsock; 1314 } 1315 1316 return 0; 1317 1318 create_delsock: 1319 sock_release(sock); 1320 con->sock = NULL; 1321 out: 1322 return result; 1323 } 1324 1325 static int tcp_listen_for_all(void) 1326 { 1327 struct socket *sock = NULL; 1328 struct connection *con = nodeid2con(0, GFP_NOFS); 1329 int result = -EINVAL; 1330 1331 if (!con) 1332 return -ENOMEM; 1333 1334 /* We don't support multi-homed hosts */ 1335 if (dlm_local_addr[1] != NULL) { 1336 log_print("TCP protocol can't handle multi-homed hosts, " 1337 "try SCTP"); 1338 return -EINVAL; 1339 } 1340 1341 log_print("Using TCP for communications"); 1342 1343 sock = tcp_create_listen_sock(con, dlm_local_addr[0]); 1344 if (sock) { 1345 add_sock(sock, con); 1346 result = 0; 1347 } 1348 else { 1349 result = -EADDRINUSE; 1350 } 1351 1352 return result; 1353 } 1354 1355 1356 1357 static struct writequeue_entry *new_writequeue_entry(struct connection *con, 1358 gfp_t allocation) 1359 { 1360 struct writequeue_entry *entry; 1361 1362 entry = kmalloc(sizeof(struct writequeue_entry), allocation); 1363 if (!entry) 1364 return NULL; 1365 1366 entry->page = alloc_page(allocation); 1367 if (!entry->page) { 1368 kfree(entry); 1369 return NULL; 1370 } 1371 1372 entry->offset = 0; 1373 entry->len = 0; 1374 entry->end = 0; 1375 entry->users = 0; 1376 entry->con = con; 1377 1378 return entry; 1379 } 1380 1381 void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc) 1382 { 1383 struct connection *con; 1384 struct writequeue_entry *e; 1385 int offset = 0; 1386 1387 con = nodeid2con(nodeid, allocation); 1388 if (!con) 1389 return NULL; 1390 1391 spin_lock(&con->writequeue_lock); 1392 e = list_entry(con->writequeue.prev, struct writequeue_entry, list); 1393 if ((&e->list == &con->writequeue) || 1394 (PAGE_CACHE_SIZE - e->end < len)) { 1395 e = NULL; 1396 } else { 1397 offset = e->end; 1398 e->end += len; 1399 e->users++; 1400 } 1401 spin_unlock(&con->writequeue_lock); 1402 1403 if (e) { 1404 got_one: 1405 *ppc = page_address(e->page) + offset; 1406 return e; 1407 } 1408 1409 e = new_writequeue_entry(con, allocation); 1410 if (e) { 1411 spin_lock(&con->writequeue_lock); 1412 offset = e->end; 1413 e->end += len; 1414 e->users++; 1415 list_add_tail(&e->list, &con->writequeue); 1416 spin_unlock(&con->writequeue_lock); 1417 goto got_one; 1418 } 1419 return NULL; 1420 } 1421 1422 void dlm_lowcomms_commit_buffer(void *mh) 1423 { 1424 struct writequeue_entry *e = (struct writequeue_entry *)mh; 1425 struct connection *con = e->con; 1426 int users; 1427 1428 spin_lock(&con->writequeue_lock); 1429 users = --e->users; 1430 if (users) 1431 goto out; 1432 e->len = e->end - e->offset; 1433 spin_unlock(&con->writequeue_lock); 1434 1435 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) { 1436 queue_work(send_workqueue, &con->swork); 1437 } 1438 return; 1439 1440 out: 1441 spin_unlock(&con->writequeue_lock); 1442 return; 1443 } 1444 1445 /* Send a message */ 1446 static void send_to_sock(struct connection *con) 1447 { 1448 int ret = 0; 1449 const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL; 1450 struct writequeue_entry *e; 1451 int len, offset; 1452 int count = 0; 1453 1454 mutex_lock(&con->sock_mutex); 1455 if (con->sock == NULL) 1456 goto out_connect; 1457 1458 spin_lock(&con->writequeue_lock); 1459 for (;;) { 1460 e = list_entry(con->writequeue.next, struct writequeue_entry, 1461 list); 1462 if ((struct list_head *) e == &con->writequeue) 1463 break; 1464 1465 len = e->len; 1466 offset = e->offset; 1467 BUG_ON(len == 0 && e->users == 0); 1468 spin_unlock(&con->writequeue_lock); 1469 1470 ret = 0; 1471 if (len) { 1472 ret = kernel_sendpage(con->sock, e->page, offset, len, 1473 msg_flags); 1474 if (ret == -EAGAIN || ret == 0) { 1475 if (ret == -EAGAIN && 1476 test_bit(SOCK_ASYNC_NOSPACE, &con->sock->flags) && 1477 !test_and_set_bit(CF_APP_LIMITED, &con->flags)) { 1478 /* Notify TCP that we're limited by the 1479 * application window size. 1480 */ 1481 set_bit(SOCK_NOSPACE, &con->sock->flags); 1482 con->sock->sk->sk_write_pending++; 1483 } 1484 cond_resched(); 1485 goto out; 1486 } else if (ret < 0) 1487 goto send_error; 1488 } 1489 1490 /* Don't starve people filling buffers */ 1491 if (++count >= MAX_SEND_MSG_COUNT) { 1492 cond_resched(); 1493 count = 0; 1494 } 1495 1496 spin_lock(&con->writequeue_lock); 1497 e->offset += ret; 1498 e->len -= ret; 1499 1500 if (e->len == 0 && e->users == 0) { 1501 list_del(&e->list); 1502 free_entry(e); 1503 } 1504 } 1505 spin_unlock(&con->writequeue_lock); 1506 out: 1507 mutex_unlock(&con->sock_mutex); 1508 return; 1509 1510 send_error: 1511 mutex_unlock(&con->sock_mutex); 1512 close_connection(con, false); 1513 lowcomms_connect_sock(con); 1514 return; 1515 1516 out_connect: 1517 mutex_unlock(&con->sock_mutex); 1518 if (!test_bit(CF_INIT_PENDING, &con->flags)) 1519 lowcomms_connect_sock(con); 1520 } 1521 1522 static void clean_one_writequeue(struct connection *con) 1523 { 1524 struct writequeue_entry *e, *safe; 1525 1526 spin_lock(&con->writequeue_lock); 1527 list_for_each_entry_safe(e, safe, &con->writequeue, list) { 1528 list_del(&e->list); 1529 free_entry(e); 1530 } 1531 spin_unlock(&con->writequeue_lock); 1532 } 1533 1534 /* Called from recovery when it knows that a node has 1535 left the cluster */ 1536 int dlm_lowcomms_close(int nodeid) 1537 { 1538 struct connection *con; 1539 struct dlm_node_addr *na; 1540 1541 log_print("closing connection to node %d", nodeid); 1542 con = nodeid2con(nodeid, 0); 1543 if (con) { 1544 clear_bit(CF_CONNECT_PENDING, &con->flags); 1545 clear_bit(CF_WRITE_PENDING, &con->flags); 1546 set_bit(CF_CLOSE, &con->flags); 1547 if (cancel_work_sync(&con->swork)) 1548 log_print("canceled swork for node %d", nodeid); 1549 if (cancel_work_sync(&con->rwork)) 1550 log_print("canceled rwork for node %d", nodeid); 1551 clean_one_writequeue(con); 1552 close_connection(con, true); 1553 } 1554 1555 spin_lock(&dlm_node_addrs_spin); 1556 na = find_node_addr(nodeid); 1557 if (na) { 1558 list_del(&na->list); 1559 while (na->addr_count--) 1560 kfree(na->addr[na->addr_count]); 1561 kfree(na); 1562 } 1563 spin_unlock(&dlm_node_addrs_spin); 1564 1565 return 0; 1566 } 1567 1568 /* Receive workqueue function */ 1569 static void process_recv_sockets(struct work_struct *work) 1570 { 1571 struct connection *con = container_of(work, struct connection, rwork); 1572 int err; 1573 1574 clear_bit(CF_READ_PENDING, &con->flags); 1575 do { 1576 err = con->rx_action(con); 1577 } while (!err); 1578 } 1579 1580 /* Send workqueue function */ 1581 static void process_send_sockets(struct work_struct *work) 1582 { 1583 struct connection *con = container_of(work, struct connection, swork); 1584 1585 if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) { 1586 con->connect_action(con); 1587 set_bit(CF_WRITE_PENDING, &con->flags); 1588 } 1589 if (test_and_clear_bit(CF_WRITE_PENDING, &con->flags)) 1590 send_to_sock(con); 1591 } 1592 1593 1594 /* Discard all entries on the write queues */ 1595 static void clean_writequeues(void) 1596 { 1597 foreach_conn(clean_one_writequeue); 1598 } 1599 1600 static void work_stop(void) 1601 { 1602 destroy_workqueue(recv_workqueue); 1603 destroy_workqueue(send_workqueue); 1604 } 1605 1606 static int work_start(void) 1607 { 1608 recv_workqueue = alloc_workqueue("dlm_recv", 1609 WQ_UNBOUND | WQ_MEM_RECLAIM, 1); 1610 if (!recv_workqueue) { 1611 log_print("can't start dlm_recv"); 1612 return -ENOMEM; 1613 } 1614 1615 send_workqueue = alloc_workqueue("dlm_send", 1616 WQ_UNBOUND | WQ_MEM_RECLAIM, 1); 1617 if (!send_workqueue) { 1618 log_print("can't start dlm_send"); 1619 destroy_workqueue(recv_workqueue); 1620 return -ENOMEM; 1621 } 1622 1623 return 0; 1624 } 1625 1626 static void stop_conn(struct connection *con) 1627 { 1628 con->flags |= 0x0F; 1629 if (con->sock && con->sock->sk) 1630 con->sock->sk->sk_user_data = NULL; 1631 } 1632 1633 static void free_conn(struct connection *con) 1634 { 1635 close_connection(con, true); 1636 if (con->othercon) 1637 kmem_cache_free(con_cache, con->othercon); 1638 hlist_del(&con->list); 1639 kmem_cache_free(con_cache, con); 1640 } 1641 1642 void dlm_lowcomms_stop(void) 1643 { 1644 /* Set all the flags to prevent any 1645 socket activity. 1646 */ 1647 mutex_lock(&connections_lock); 1648 dlm_allow_conn = 0; 1649 foreach_conn(stop_conn); 1650 mutex_unlock(&connections_lock); 1651 1652 work_stop(); 1653 1654 mutex_lock(&connections_lock); 1655 clean_writequeues(); 1656 1657 foreach_conn(free_conn); 1658 1659 mutex_unlock(&connections_lock); 1660 kmem_cache_destroy(con_cache); 1661 } 1662 1663 int dlm_lowcomms_start(void) 1664 { 1665 int error = -EINVAL; 1666 struct connection *con; 1667 int i; 1668 1669 for (i = 0; i < CONN_HASH_SIZE; i++) 1670 INIT_HLIST_HEAD(&connection_hash[i]); 1671 1672 init_local(); 1673 if (!dlm_local_count) { 1674 error = -ENOTCONN; 1675 log_print("no local IP address has been set"); 1676 goto fail; 1677 } 1678 1679 error = -ENOMEM; 1680 con_cache = kmem_cache_create("dlm_conn", sizeof(struct connection), 1681 __alignof__(struct connection), 0, 1682 NULL); 1683 if (!con_cache) 1684 goto fail; 1685 1686 error = work_start(); 1687 if (error) 1688 goto fail_destroy; 1689 1690 dlm_allow_conn = 1; 1691 1692 /* Start listening */ 1693 if (dlm_config.ci_protocol == 0) 1694 error = tcp_listen_for_all(); 1695 else 1696 error = sctp_listen_for_all(); 1697 if (error) 1698 goto fail_unlisten; 1699 1700 return 0; 1701 1702 fail_unlisten: 1703 dlm_allow_conn = 0; 1704 con = nodeid2con(0,0); 1705 if (con) { 1706 close_connection(con, false); 1707 kmem_cache_free(con_cache, con); 1708 } 1709 fail_destroy: 1710 kmem_cache_destroy(con_cache); 1711 fail: 1712 return error; 1713 } 1714 1715 void dlm_lowcomms_exit(void) 1716 { 1717 struct dlm_node_addr *na, *safe; 1718 1719 spin_lock(&dlm_node_addrs_spin); 1720 list_for_each_entry_safe(na, safe, &dlm_node_addrs, list) { 1721 list_del(&na->list); 1722 while (na->addr_count--) 1723 kfree(na->addr[na->addr_count]); 1724 kfree(na); 1725 } 1726 spin_unlock(&dlm_node_addrs_spin); 1727 } 1728