1 /****************************************************************************** 2 ******************************************************************************* 3 ** 4 ** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. 5 ** Copyright (C) 2004-2007 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 it's 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 wither 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 shouldbe 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/idr.h> 52 #include <linux/file.h> 53 #include <linux/sctp.h> 54 #include <net/sctp/user.h> 55 56 #include "dlm_internal.h" 57 #include "lowcomms.h" 58 #include "midcomms.h" 59 #include "config.h" 60 61 #define NEEDED_RMEM (4*1024*1024) 62 63 struct cbuf { 64 unsigned int base; 65 unsigned int len; 66 unsigned int mask; 67 }; 68 69 static void cbuf_add(struct cbuf *cb, int n) 70 { 71 cb->len += n; 72 } 73 74 static int cbuf_data(struct cbuf *cb) 75 { 76 return ((cb->base + cb->len) & cb->mask); 77 } 78 79 static void cbuf_init(struct cbuf *cb, int size) 80 { 81 cb->base = cb->len = 0; 82 cb->mask = size-1; 83 } 84 85 static void cbuf_eat(struct cbuf *cb, int n) 86 { 87 cb->len -= n; 88 cb->base += n; 89 cb->base &= cb->mask; 90 } 91 92 static bool cbuf_empty(struct cbuf *cb) 93 { 94 return cb->len == 0; 95 } 96 97 struct connection { 98 struct socket *sock; /* NULL if not connected */ 99 uint32_t nodeid; /* So we know who we are in the list */ 100 struct mutex sock_mutex; 101 unsigned long flags; 102 #define CF_READ_PENDING 1 103 #define CF_WRITE_PENDING 2 104 #define CF_CONNECT_PENDING 3 105 #define CF_INIT_PENDING 4 106 #define CF_IS_OTHERCON 5 107 struct list_head writequeue; /* List of outgoing writequeue_entries */ 108 spinlock_t writequeue_lock; 109 int (*rx_action) (struct connection *); /* What to do when active */ 110 void (*connect_action) (struct connection *); /* What to do to connect */ 111 struct page *rx_page; 112 struct cbuf cb; 113 int retries; 114 #define MAX_CONNECT_RETRIES 3 115 int sctp_assoc; 116 struct connection *othercon; 117 struct work_struct rwork; /* Receive workqueue */ 118 struct work_struct swork; /* Send workqueue */ 119 }; 120 #define sock2con(x) ((struct connection *)(x)->sk_user_data) 121 122 /* An entry waiting to be sent */ 123 struct writequeue_entry { 124 struct list_head list; 125 struct page *page; 126 int offset; 127 int len; 128 int end; 129 int users; 130 struct connection *con; 131 }; 132 133 static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT]; 134 static int dlm_local_count; 135 136 /* Work queues */ 137 static struct workqueue_struct *recv_workqueue; 138 static struct workqueue_struct *send_workqueue; 139 140 static DEFINE_IDR(connections_idr); 141 static DECLARE_MUTEX(connections_lock); 142 static int max_nodeid; 143 static struct kmem_cache *con_cache; 144 145 static void process_recv_sockets(struct work_struct *work); 146 static void process_send_sockets(struct work_struct *work); 147 148 /* 149 * If 'allocation' is zero then we don't attempt to create a new 150 * connection structure for this node. 151 */ 152 static struct connection *__nodeid2con(int nodeid, gfp_t alloc) 153 { 154 struct connection *con = NULL; 155 int r; 156 int n; 157 158 con = idr_find(&connections_idr, nodeid); 159 if (con || !alloc) 160 return con; 161 162 r = idr_pre_get(&connections_idr, alloc); 163 if (!r) 164 return NULL; 165 166 con = kmem_cache_zalloc(con_cache, alloc); 167 if (!con) 168 return NULL; 169 170 r = idr_get_new_above(&connections_idr, con, nodeid, &n); 171 if (r) { 172 kmem_cache_free(con_cache, con); 173 return NULL; 174 } 175 176 if (n != nodeid) { 177 idr_remove(&connections_idr, n); 178 kmem_cache_free(con_cache, con); 179 return NULL; 180 } 181 182 con->nodeid = nodeid; 183 mutex_init(&con->sock_mutex); 184 INIT_LIST_HEAD(&con->writequeue); 185 spin_lock_init(&con->writequeue_lock); 186 INIT_WORK(&con->swork, process_send_sockets); 187 INIT_WORK(&con->rwork, process_recv_sockets); 188 189 /* Setup action pointers for child sockets */ 190 if (con->nodeid) { 191 struct connection *zerocon = idr_find(&connections_idr, 0); 192 193 con->connect_action = zerocon->connect_action; 194 if (!con->rx_action) 195 con->rx_action = zerocon->rx_action; 196 } 197 198 if (nodeid > max_nodeid) 199 max_nodeid = nodeid; 200 201 return con; 202 } 203 204 static struct connection *nodeid2con(int nodeid, gfp_t allocation) 205 { 206 struct connection *con; 207 208 down(&connections_lock); 209 con = __nodeid2con(nodeid, allocation); 210 up(&connections_lock); 211 212 return con; 213 } 214 215 /* This is a bit drastic, but only called when things go wrong */ 216 static struct connection *assoc2con(int assoc_id) 217 { 218 int i; 219 struct connection *con; 220 221 down(&connections_lock); 222 for (i=0; i<=max_nodeid; i++) { 223 con = __nodeid2con(i, 0); 224 if (con && con->sctp_assoc == assoc_id) { 225 up(&connections_lock); 226 return con; 227 } 228 } 229 up(&connections_lock); 230 return NULL; 231 } 232 233 static int nodeid_to_addr(int nodeid, struct sockaddr *retaddr) 234 { 235 struct sockaddr_storage addr; 236 int error; 237 238 if (!dlm_local_count) 239 return -1; 240 241 error = dlm_nodeid_to_addr(nodeid, &addr); 242 if (error) 243 return error; 244 245 if (dlm_local_addr[0]->ss_family == AF_INET) { 246 struct sockaddr_in *in4 = (struct sockaddr_in *) &addr; 247 struct sockaddr_in *ret4 = (struct sockaddr_in *) retaddr; 248 ret4->sin_addr.s_addr = in4->sin_addr.s_addr; 249 } else { 250 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) &addr; 251 struct sockaddr_in6 *ret6 = (struct sockaddr_in6 *) retaddr; 252 memcpy(&ret6->sin6_addr, &in6->sin6_addr, 253 sizeof(in6->sin6_addr)); 254 } 255 256 return 0; 257 } 258 259 /* Data available on socket or listen socket received a connect */ 260 static void lowcomms_data_ready(struct sock *sk, int count_unused) 261 { 262 struct connection *con = sock2con(sk); 263 if (con && !test_and_set_bit(CF_READ_PENDING, &con->flags)) 264 queue_work(recv_workqueue, &con->rwork); 265 } 266 267 static void lowcomms_write_space(struct sock *sk) 268 { 269 struct connection *con = sock2con(sk); 270 271 if (con && !test_and_set_bit(CF_WRITE_PENDING, &con->flags)) 272 queue_work(send_workqueue, &con->swork); 273 } 274 275 static inline void lowcomms_connect_sock(struct connection *con) 276 { 277 if (!test_and_set_bit(CF_CONNECT_PENDING, &con->flags)) 278 queue_work(send_workqueue, &con->swork); 279 } 280 281 static void lowcomms_state_change(struct sock *sk) 282 { 283 if (sk->sk_state == TCP_ESTABLISHED) 284 lowcomms_write_space(sk); 285 } 286 287 /* Make a socket active */ 288 static int add_sock(struct socket *sock, struct connection *con) 289 { 290 con->sock = sock; 291 292 /* Install a data_ready callback */ 293 con->sock->sk->sk_data_ready = lowcomms_data_ready; 294 con->sock->sk->sk_write_space = lowcomms_write_space; 295 con->sock->sk->sk_state_change = lowcomms_state_change; 296 con->sock->sk->sk_user_data = con; 297 return 0; 298 } 299 300 /* Add the port number to an IPv6 or 4 sockaddr and return the address 301 length */ 302 static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port, 303 int *addr_len) 304 { 305 saddr->ss_family = dlm_local_addr[0]->ss_family; 306 if (saddr->ss_family == AF_INET) { 307 struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr; 308 in4_addr->sin_port = cpu_to_be16(port); 309 *addr_len = sizeof(struct sockaddr_in); 310 memset(&in4_addr->sin_zero, 0, sizeof(in4_addr->sin_zero)); 311 } else { 312 struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr; 313 in6_addr->sin6_port = cpu_to_be16(port); 314 *addr_len = sizeof(struct sockaddr_in6); 315 } 316 } 317 318 /* Close a remote connection and tidy up */ 319 static void close_connection(struct connection *con, bool and_other) 320 { 321 mutex_lock(&con->sock_mutex); 322 323 if (con->sock) { 324 sock_release(con->sock); 325 con->sock = NULL; 326 } 327 if (con->othercon && and_other) { 328 /* Will only re-enter once. */ 329 close_connection(con->othercon, false); 330 } 331 if (con->rx_page) { 332 __free_page(con->rx_page); 333 con->rx_page = NULL; 334 } 335 con->retries = 0; 336 mutex_unlock(&con->sock_mutex); 337 } 338 339 /* We only send shutdown messages to nodes that are not part of the cluster */ 340 static void sctp_send_shutdown(sctp_assoc_t associd) 341 { 342 static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 343 struct msghdr outmessage; 344 struct cmsghdr *cmsg; 345 struct sctp_sndrcvinfo *sinfo; 346 int ret; 347 struct connection *con; 348 349 con = nodeid2con(0,0); 350 BUG_ON(con == NULL); 351 352 outmessage.msg_name = NULL; 353 outmessage.msg_namelen = 0; 354 outmessage.msg_control = outcmsg; 355 outmessage.msg_controllen = sizeof(outcmsg); 356 outmessage.msg_flags = MSG_EOR; 357 358 cmsg = CMSG_FIRSTHDR(&outmessage); 359 cmsg->cmsg_level = IPPROTO_SCTP; 360 cmsg->cmsg_type = SCTP_SNDRCV; 361 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo)); 362 outmessage.msg_controllen = cmsg->cmsg_len; 363 sinfo = CMSG_DATA(cmsg); 364 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo)); 365 366 sinfo->sinfo_flags |= MSG_EOF; 367 sinfo->sinfo_assoc_id = associd; 368 369 ret = kernel_sendmsg(con->sock, &outmessage, NULL, 0, 0); 370 371 if (ret != 0) 372 log_print("send EOF to node failed: %d", ret); 373 } 374 375 /* INIT failed but we don't know which node... 376 restart INIT on all pending nodes */ 377 static void sctp_init_failed(void) 378 { 379 int i; 380 struct connection *con; 381 382 down(&connections_lock); 383 for (i=1; i<=max_nodeid; i++) { 384 con = __nodeid2con(i, 0); 385 if (!con) 386 continue; 387 con->sctp_assoc = 0; 388 if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) { 389 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) { 390 queue_work(send_workqueue, &con->swork); 391 } 392 } 393 } 394 up(&connections_lock); 395 } 396 397 /* Something happened to an association */ 398 static void process_sctp_notification(struct connection *con, 399 struct msghdr *msg, char *buf) 400 { 401 union sctp_notification *sn = (union sctp_notification *)buf; 402 403 if (sn->sn_header.sn_type == SCTP_ASSOC_CHANGE) { 404 switch (sn->sn_assoc_change.sac_state) { 405 406 case SCTP_COMM_UP: 407 case SCTP_RESTART: 408 { 409 /* Check that the new node is in the lockspace */ 410 struct sctp_prim prim; 411 int nodeid; 412 int prim_len, ret; 413 int addr_len; 414 struct connection *new_con; 415 struct file *file; 416 sctp_peeloff_arg_t parg; 417 int parglen = sizeof(parg); 418 419 /* 420 * We get this before any data for an association. 421 * We verify that the node is in the cluster and 422 * then peel off a socket for it. 423 */ 424 if ((int)sn->sn_assoc_change.sac_assoc_id <= 0) { 425 log_print("COMM_UP for invalid assoc ID %d", 426 (int)sn->sn_assoc_change.sac_assoc_id); 427 sctp_init_failed(); 428 return; 429 } 430 memset(&prim, 0, sizeof(struct sctp_prim)); 431 prim_len = sizeof(struct sctp_prim); 432 prim.ssp_assoc_id = sn->sn_assoc_change.sac_assoc_id; 433 434 ret = kernel_getsockopt(con->sock, 435 IPPROTO_SCTP, 436 SCTP_PRIMARY_ADDR, 437 (char*)&prim, 438 &prim_len); 439 if (ret < 0) { 440 log_print("getsockopt/sctp_primary_addr on " 441 "new assoc %d failed : %d", 442 (int)sn->sn_assoc_change.sac_assoc_id, 443 ret); 444 445 /* Retry INIT later */ 446 new_con = assoc2con(sn->sn_assoc_change.sac_assoc_id); 447 if (new_con) 448 clear_bit(CF_CONNECT_PENDING, &con->flags); 449 return; 450 } 451 make_sockaddr(&prim.ssp_addr, 0, &addr_len); 452 if (dlm_addr_to_nodeid(&prim.ssp_addr, &nodeid)) { 453 int i; 454 unsigned char *b=(unsigned char *)&prim.ssp_addr; 455 log_print("reject connect from unknown addr"); 456 for (i=0; i<sizeof(struct sockaddr_storage);i++) 457 printk("%02x ", b[i]); 458 printk("\n"); 459 sctp_send_shutdown(prim.ssp_assoc_id); 460 return; 461 } 462 463 new_con = nodeid2con(nodeid, GFP_KERNEL); 464 if (!new_con) 465 return; 466 467 /* Peel off a new sock */ 468 parg.associd = sn->sn_assoc_change.sac_assoc_id; 469 ret = kernel_getsockopt(con->sock, IPPROTO_SCTP, 470 SCTP_SOCKOPT_PEELOFF, 471 (void *)&parg, &parglen); 472 if (ret) { 473 log_print("Can't peel off a socket for " 474 "connection %d to node %d: err=%d\n", 475 parg.associd, nodeid, ret); 476 } 477 file = fget(parg.sd); 478 new_con->sock = SOCKET_I(file->f_dentry->d_inode); 479 add_sock(new_con->sock, new_con); 480 fput(file); 481 put_unused_fd(parg.sd); 482 483 log_print("got new/restarted association %d nodeid %d", 484 (int)sn->sn_assoc_change.sac_assoc_id, nodeid); 485 486 /* Send any pending writes */ 487 clear_bit(CF_CONNECT_PENDING, &new_con->flags); 488 clear_bit(CF_INIT_PENDING, &con->flags); 489 if (!test_and_set_bit(CF_WRITE_PENDING, &new_con->flags)) { 490 queue_work(send_workqueue, &new_con->swork); 491 } 492 if (!test_and_set_bit(CF_READ_PENDING, &new_con->flags)) 493 queue_work(recv_workqueue, &new_con->rwork); 494 } 495 break; 496 497 case SCTP_COMM_LOST: 498 case SCTP_SHUTDOWN_COMP: 499 { 500 con = assoc2con(sn->sn_assoc_change.sac_assoc_id); 501 if (con) { 502 con->sctp_assoc = 0; 503 } 504 } 505 break; 506 507 /* We don't know which INIT failed, so clear the PENDING flags 508 * on them all. if assoc_id is zero then it will then try 509 * again */ 510 511 case SCTP_CANT_STR_ASSOC: 512 { 513 log_print("Can't start SCTP association - retrying"); 514 sctp_init_failed(); 515 } 516 break; 517 518 default: 519 log_print("unexpected SCTP assoc change id=%d state=%d", 520 (int)sn->sn_assoc_change.sac_assoc_id, 521 sn->sn_assoc_change.sac_state); 522 } 523 } 524 } 525 526 /* Data received from remote end */ 527 static int receive_from_sock(struct connection *con) 528 { 529 int ret = 0; 530 struct msghdr msg = {}; 531 struct kvec iov[2]; 532 unsigned len; 533 int r; 534 int call_again_soon = 0; 535 int nvec; 536 char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 537 538 mutex_lock(&con->sock_mutex); 539 540 if (con->sock == NULL) { 541 ret = -EAGAIN; 542 goto out_close; 543 } 544 545 if (con->rx_page == NULL) { 546 /* 547 * This doesn't need to be atomic, but I think it should 548 * improve performance if it is. 549 */ 550 con->rx_page = alloc_page(GFP_ATOMIC); 551 if (con->rx_page == NULL) 552 goto out_resched; 553 cbuf_init(&con->cb, PAGE_CACHE_SIZE); 554 } 555 556 /* Only SCTP needs these really */ 557 memset(&incmsg, 0, sizeof(incmsg)); 558 msg.msg_control = incmsg; 559 msg.msg_controllen = sizeof(incmsg); 560 561 /* 562 * iov[0] is the bit of the circular buffer between the current end 563 * point (cb.base + cb.len) and the end of the buffer. 564 */ 565 iov[0].iov_len = con->cb.base - cbuf_data(&con->cb); 566 iov[0].iov_base = page_address(con->rx_page) + cbuf_data(&con->cb); 567 iov[1].iov_len = 0; 568 nvec = 1; 569 570 /* 571 * iov[1] is the bit of the circular buffer between the start of the 572 * buffer and the start of the currently used section (cb.base) 573 */ 574 if (cbuf_data(&con->cb) >= con->cb.base) { 575 iov[0].iov_len = PAGE_CACHE_SIZE - cbuf_data(&con->cb); 576 iov[1].iov_len = con->cb.base; 577 iov[1].iov_base = page_address(con->rx_page); 578 nvec = 2; 579 } 580 len = iov[0].iov_len + iov[1].iov_len; 581 582 r = ret = kernel_recvmsg(con->sock, &msg, iov, nvec, len, 583 MSG_DONTWAIT | MSG_NOSIGNAL); 584 if (ret <= 0) 585 goto out_close; 586 587 /* Process SCTP notifications */ 588 if (msg.msg_flags & MSG_NOTIFICATION) { 589 msg.msg_control = incmsg; 590 msg.msg_controllen = sizeof(incmsg); 591 592 process_sctp_notification(con, &msg, 593 page_address(con->rx_page) + con->cb.base); 594 mutex_unlock(&con->sock_mutex); 595 return 0; 596 } 597 BUG_ON(con->nodeid == 0); 598 599 if (ret == len) 600 call_again_soon = 1; 601 cbuf_add(&con->cb, ret); 602 ret = dlm_process_incoming_buffer(con->nodeid, 603 page_address(con->rx_page), 604 con->cb.base, con->cb.len, 605 PAGE_CACHE_SIZE); 606 if (ret == -EBADMSG) { 607 log_print("lowcomms: addr=%p, base=%u, len=%u, " 608 "iov_len=%u, iov_base[0]=%p, read=%d", 609 page_address(con->rx_page), con->cb.base, con->cb.len, 610 len, iov[0].iov_base, r); 611 } 612 if (ret < 0) 613 goto out_close; 614 cbuf_eat(&con->cb, ret); 615 616 if (cbuf_empty(&con->cb) && !call_again_soon) { 617 __free_page(con->rx_page); 618 con->rx_page = NULL; 619 } 620 621 if (call_again_soon) 622 goto out_resched; 623 mutex_unlock(&con->sock_mutex); 624 return 0; 625 626 out_resched: 627 if (!test_and_set_bit(CF_READ_PENDING, &con->flags)) 628 queue_work(recv_workqueue, &con->rwork); 629 mutex_unlock(&con->sock_mutex); 630 return -EAGAIN; 631 632 out_close: 633 mutex_unlock(&con->sock_mutex); 634 if (ret != -EAGAIN && !test_bit(CF_IS_OTHERCON, &con->flags)) { 635 close_connection(con, false); 636 /* Reconnect when there is something to send */ 637 } 638 /* Don't return success if we really got EOF */ 639 if (ret == 0) 640 ret = -EAGAIN; 641 642 return ret; 643 } 644 645 /* Listening socket is busy, accept a connection */ 646 static int tcp_accept_from_sock(struct connection *con) 647 { 648 int result; 649 struct sockaddr_storage peeraddr; 650 struct socket *newsock; 651 int len; 652 int nodeid; 653 struct connection *newcon; 654 struct connection *addcon; 655 656 memset(&peeraddr, 0, sizeof(peeraddr)); 657 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 658 IPPROTO_TCP, &newsock); 659 if (result < 0) 660 return -ENOMEM; 661 662 mutex_lock_nested(&con->sock_mutex, 0); 663 664 result = -ENOTCONN; 665 if (con->sock == NULL) 666 goto accept_err; 667 668 newsock->type = con->sock->type; 669 newsock->ops = con->sock->ops; 670 671 result = con->sock->ops->accept(con->sock, newsock, O_NONBLOCK); 672 if (result < 0) 673 goto accept_err; 674 675 /* Get the connected socket's peer */ 676 memset(&peeraddr, 0, sizeof(peeraddr)); 677 if (newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr, 678 &len, 2)) { 679 result = -ECONNABORTED; 680 goto accept_err; 681 } 682 683 /* Get the new node's NODEID */ 684 make_sockaddr(&peeraddr, 0, &len); 685 if (dlm_addr_to_nodeid(&peeraddr, &nodeid)) { 686 log_print("connect from non cluster node"); 687 sock_release(newsock); 688 mutex_unlock(&con->sock_mutex); 689 return -1; 690 } 691 692 log_print("got connection from %d", nodeid); 693 694 /* Check to see if we already have a connection to this node. This 695 * could happen if the two nodes initiate a connection at roughly 696 * the same time and the connections cross on the wire. 697 * In this case we store the incoming one in "othercon" 698 */ 699 newcon = nodeid2con(nodeid, GFP_KERNEL); 700 if (!newcon) { 701 result = -ENOMEM; 702 goto accept_err; 703 } 704 mutex_lock_nested(&newcon->sock_mutex, 1); 705 if (newcon->sock) { 706 struct connection *othercon = newcon->othercon; 707 708 if (!othercon) { 709 othercon = kmem_cache_zalloc(con_cache, GFP_KERNEL); 710 if (!othercon) { 711 log_print("failed to allocate incoming socket"); 712 mutex_unlock(&newcon->sock_mutex); 713 result = -ENOMEM; 714 goto accept_err; 715 } 716 othercon->nodeid = nodeid; 717 othercon->rx_action = receive_from_sock; 718 mutex_init(&othercon->sock_mutex); 719 INIT_WORK(&othercon->swork, process_send_sockets); 720 INIT_WORK(&othercon->rwork, process_recv_sockets); 721 set_bit(CF_IS_OTHERCON, &othercon->flags); 722 newcon->othercon = othercon; 723 othercon->sock = newsock; 724 newsock->sk->sk_user_data = othercon; 725 add_sock(newsock, othercon); 726 addcon = othercon; 727 } 728 else { 729 printk("Extra connection from node %d attempted\n", nodeid); 730 result = -EAGAIN; 731 mutex_unlock(&newcon->sock_mutex); 732 goto accept_err; 733 } 734 } 735 else { 736 newsock->sk->sk_user_data = newcon; 737 newcon->rx_action = receive_from_sock; 738 add_sock(newsock, newcon); 739 addcon = newcon; 740 } 741 742 mutex_unlock(&newcon->sock_mutex); 743 744 /* 745 * Add it to the active queue in case we got data 746 * beween processing the accept adding the socket 747 * to the read_sockets list 748 */ 749 if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags)) 750 queue_work(recv_workqueue, &addcon->rwork); 751 mutex_unlock(&con->sock_mutex); 752 753 return 0; 754 755 accept_err: 756 mutex_unlock(&con->sock_mutex); 757 sock_release(newsock); 758 759 if (result != -EAGAIN) 760 log_print("error accepting connection from node: %d", result); 761 return result; 762 } 763 764 static void free_entry(struct writequeue_entry *e) 765 { 766 __free_page(e->page); 767 kfree(e); 768 } 769 770 /* Initiate an SCTP association. 771 This is a special case of send_to_sock() in that we don't yet have a 772 peeled-off socket for this association, so we use the listening socket 773 and add the primary IP address of the remote node. 774 */ 775 static void sctp_init_assoc(struct connection *con) 776 { 777 struct sockaddr_storage rem_addr; 778 char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; 779 struct msghdr outmessage; 780 struct cmsghdr *cmsg; 781 struct sctp_sndrcvinfo *sinfo; 782 struct connection *base_con; 783 struct writequeue_entry *e; 784 int len, offset; 785 int ret; 786 int addrlen; 787 struct kvec iov[1]; 788 789 if (test_and_set_bit(CF_INIT_PENDING, &con->flags)) 790 return; 791 792 if (con->retries++ > MAX_CONNECT_RETRIES) 793 return; 794 795 log_print("Initiating association with node %d", con->nodeid); 796 797 if (nodeid_to_addr(con->nodeid, (struct sockaddr *)&rem_addr)) { 798 log_print("no address for nodeid %d", con->nodeid); 799 return; 800 } 801 base_con = nodeid2con(0, 0); 802 BUG_ON(base_con == NULL); 803 804 make_sockaddr(&rem_addr, dlm_config.ci_tcp_port, &addrlen); 805 806 outmessage.msg_name = &rem_addr; 807 outmessage.msg_namelen = addrlen; 808 outmessage.msg_control = outcmsg; 809 outmessage.msg_controllen = sizeof(outcmsg); 810 outmessage.msg_flags = MSG_EOR; 811 812 spin_lock(&con->writequeue_lock); 813 e = list_entry(con->writequeue.next, struct writequeue_entry, 814 list); 815 816 BUG_ON((struct list_head *) e == &con->writequeue); 817 818 len = e->len; 819 offset = e->offset; 820 spin_unlock(&con->writequeue_lock); 821 kmap(e->page); 822 823 /* Send the first block off the write queue */ 824 iov[0].iov_base = page_address(e->page)+offset; 825 iov[0].iov_len = len; 826 827 cmsg = CMSG_FIRSTHDR(&outmessage); 828 cmsg->cmsg_level = IPPROTO_SCTP; 829 cmsg->cmsg_type = SCTP_SNDRCV; 830 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo)); 831 sinfo = CMSG_DATA(cmsg); 832 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo)); 833 sinfo->sinfo_ppid = cpu_to_le32(dlm_our_nodeid()); 834 outmessage.msg_controllen = cmsg->cmsg_len; 835 836 ret = kernel_sendmsg(base_con->sock, &outmessage, iov, 1, len); 837 if (ret < 0) { 838 log_print("Send first packet to node %d failed: %d", 839 con->nodeid, ret); 840 841 /* Try again later */ 842 clear_bit(CF_CONNECT_PENDING, &con->flags); 843 clear_bit(CF_INIT_PENDING, &con->flags); 844 } 845 else { 846 spin_lock(&con->writequeue_lock); 847 e->offset += ret; 848 e->len -= ret; 849 850 if (e->len == 0 && e->users == 0) { 851 list_del(&e->list); 852 kunmap(e->page); 853 free_entry(e); 854 } 855 spin_unlock(&con->writequeue_lock); 856 } 857 } 858 859 /* Connect a new socket to its peer */ 860 static void tcp_connect_to_sock(struct connection *con) 861 { 862 int result = -EHOSTUNREACH; 863 struct sockaddr_storage saddr; 864 int addr_len; 865 struct socket *sock; 866 867 if (con->nodeid == 0) { 868 log_print("attempt to connect sock 0 foiled"); 869 return; 870 } 871 872 mutex_lock(&con->sock_mutex); 873 if (con->retries++ > MAX_CONNECT_RETRIES) 874 goto out; 875 876 /* Some odd races can cause double-connects, ignore them */ 877 if (con->sock) { 878 result = 0; 879 goto out; 880 } 881 882 /* Create a socket to communicate with */ 883 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 884 IPPROTO_TCP, &sock); 885 if (result < 0) 886 goto out_err; 887 888 memset(&saddr, 0, sizeof(saddr)); 889 if (dlm_nodeid_to_addr(con->nodeid, &saddr)) 890 goto out_err; 891 892 sock->sk->sk_user_data = con; 893 con->rx_action = receive_from_sock; 894 con->connect_action = tcp_connect_to_sock; 895 add_sock(sock, con); 896 897 make_sockaddr(&saddr, dlm_config.ci_tcp_port, &addr_len); 898 899 log_print("connecting to %d", con->nodeid); 900 result = 901 sock->ops->connect(sock, (struct sockaddr *)&saddr, addr_len, 902 O_NONBLOCK); 903 if (result == -EINPROGRESS) 904 result = 0; 905 if (result == 0) 906 goto out; 907 908 out_err: 909 if (con->sock) { 910 sock_release(con->sock); 911 con->sock = NULL; 912 } 913 /* 914 * Some errors are fatal and this list might need adjusting. For other 915 * errors we try again until the max number of retries is reached. 916 */ 917 if (result != -EHOSTUNREACH && result != -ENETUNREACH && 918 result != -ENETDOWN && result != EINVAL 919 && result != -EPROTONOSUPPORT) { 920 lowcomms_connect_sock(con); 921 result = 0; 922 } 923 out: 924 mutex_unlock(&con->sock_mutex); 925 return; 926 } 927 928 static struct socket *tcp_create_listen_sock(struct connection *con, 929 struct sockaddr_storage *saddr) 930 { 931 struct socket *sock = NULL; 932 int result = 0; 933 int one = 1; 934 int addr_len; 935 936 if (dlm_local_addr[0]->ss_family == AF_INET) 937 addr_len = sizeof(struct sockaddr_in); 938 else 939 addr_len = sizeof(struct sockaddr_in6); 940 941 /* Create a socket to communicate with */ 942 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, 943 IPPROTO_TCP, &sock); 944 if (result < 0) { 945 log_print("Can't create listening comms socket"); 946 goto create_out; 947 } 948 949 result = kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, 950 (char *)&one, sizeof(one)); 951 952 if (result < 0) { 953 log_print("Failed to set SO_REUSEADDR on socket: %d", result); 954 } 955 sock->sk->sk_user_data = con; 956 con->rx_action = tcp_accept_from_sock; 957 con->connect_action = tcp_connect_to_sock; 958 con->sock = sock; 959 960 /* Bind to our port */ 961 make_sockaddr(saddr, dlm_config.ci_tcp_port, &addr_len); 962 result = sock->ops->bind(sock, (struct sockaddr *) saddr, addr_len); 963 if (result < 0) { 964 log_print("Can't bind to port %d", dlm_config.ci_tcp_port); 965 sock_release(sock); 966 sock = NULL; 967 con->sock = NULL; 968 goto create_out; 969 } 970 result = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, 971 (char *)&one, sizeof(one)); 972 if (result < 0) { 973 log_print("Set keepalive failed: %d", result); 974 } 975 976 result = sock->ops->listen(sock, 5); 977 if (result < 0) { 978 log_print("Can't listen on port %d", dlm_config.ci_tcp_port); 979 sock_release(sock); 980 sock = NULL; 981 goto create_out; 982 } 983 984 create_out: 985 return sock; 986 } 987 988 /* Get local addresses */ 989 static void init_local(void) 990 { 991 struct sockaddr_storage sas, *addr; 992 int i; 993 994 dlm_local_count = 0; 995 for (i = 0; i < DLM_MAX_ADDR_COUNT - 1; i++) { 996 if (dlm_our_addr(&sas, i)) 997 break; 998 999 addr = kmalloc(sizeof(*addr), GFP_KERNEL); 1000 if (!addr) 1001 break; 1002 memcpy(addr, &sas, sizeof(*addr)); 1003 dlm_local_addr[dlm_local_count++] = addr; 1004 } 1005 } 1006 1007 /* Bind to an IP address. SCTP allows multiple address so it can do 1008 multi-homing */ 1009 static int add_sctp_bind_addr(struct connection *sctp_con, 1010 struct sockaddr_storage *addr, 1011 int addr_len, int num) 1012 { 1013 int result = 0; 1014 1015 if (num == 1) 1016 result = kernel_bind(sctp_con->sock, 1017 (struct sockaddr *) addr, 1018 addr_len); 1019 else 1020 result = kernel_setsockopt(sctp_con->sock, SOL_SCTP, 1021 SCTP_SOCKOPT_BINDX_ADD, 1022 (char *)addr, addr_len); 1023 1024 if (result < 0) 1025 log_print("Can't bind to port %d addr number %d", 1026 dlm_config.ci_tcp_port, num); 1027 1028 return result; 1029 } 1030 1031 /* Initialise SCTP socket and bind to all interfaces */ 1032 static int sctp_listen_for_all(void) 1033 { 1034 struct socket *sock = NULL; 1035 struct sockaddr_storage localaddr; 1036 struct sctp_event_subscribe subscribe; 1037 int result = -EINVAL, num = 1, i, addr_len; 1038 struct connection *con = nodeid2con(0, GFP_KERNEL); 1039 int bufsize = NEEDED_RMEM; 1040 1041 if (!con) 1042 return -ENOMEM; 1043 1044 log_print("Using SCTP for communications"); 1045 1046 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_SEQPACKET, 1047 IPPROTO_SCTP, &sock); 1048 if (result < 0) { 1049 log_print("Can't create comms socket, check SCTP is loaded"); 1050 goto out; 1051 } 1052 1053 /* Listen for events */ 1054 memset(&subscribe, 0, sizeof(subscribe)); 1055 subscribe.sctp_data_io_event = 1; 1056 subscribe.sctp_association_event = 1; 1057 subscribe.sctp_send_failure_event = 1; 1058 subscribe.sctp_shutdown_event = 1; 1059 subscribe.sctp_partial_delivery_event = 1; 1060 1061 result = kernel_setsockopt(sock, SOL_SOCKET, SO_RCVBUF, 1062 (char *)&bufsize, sizeof(bufsize)); 1063 if (result) 1064 log_print("Error increasing buffer space on socket %d", result); 1065 1066 result = kernel_setsockopt(sock, SOL_SCTP, SCTP_EVENTS, 1067 (char *)&subscribe, sizeof(subscribe)); 1068 if (result < 0) { 1069 log_print("Failed to set SCTP_EVENTS on socket: result=%d", 1070 result); 1071 goto create_delsock; 1072 } 1073 1074 /* Init con struct */ 1075 sock->sk->sk_user_data = con; 1076 con->sock = sock; 1077 con->sock->sk->sk_data_ready = lowcomms_data_ready; 1078 con->rx_action = receive_from_sock; 1079 con->connect_action = sctp_init_assoc; 1080 1081 /* Bind to all interfaces. */ 1082 for (i = 0; i < dlm_local_count; i++) { 1083 memcpy(&localaddr, dlm_local_addr[i], sizeof(localaddr)); 1084 make_sockaddr(&localaddr, dlm_config.ci_tcp_port, &addr_len); 1085 1086 result = add_sctp_bind_addr(con, &localaddr, addr_len, num); 1087 if (result) 1088 goto create_delsock; 1089 ++num; 1090 } 1091 1092 result = sock->ops->listen(sock, 5); 1093 if (result < 0) { 1094 log_print("Can't set socket listening"); 1095 goto create_delsock; 1096 } 1097 1098 return 0; 1099 1100 create_delsock: 1101 sock_release(sock); 1102 con->sock = NULL; 1103 out: 1104 return result; 1105 } 1106 1107 static int tcp_listen_for_all(void) 1108 { 1109 struct socket *sock = NULL; 1110 struct connection *con = nodeid2con(0, GFP_KERNEL); 1111 int result = -EINVAL; 1112 1113 if (!con) 1114 return -ENOMEM; 1115 1116 /* We don't support multi-homed hosts */ 1117 if (dlm_local_addr[1] != NULL) { 1118 log_print("TCP protocol can't handle multi-homed hosts, " 1119 "try SCTP"); 1120 return -EINVAL; 1121 } 1122 1123 log_print("Using TCP for communications"); 1124 1125 set_bit(CF_IS_OTHERCON, &con->flags); 1126 1127 sock = tcp_create_listen_sock(con, dlm_local_addr[0]); 1128 if (sock) { 1129 add_sock(sock, con); 1130 result = 0; 1131 } 1132 else { 1133 result = -EADDRINUSE; 1134 } 1135 1136 return result; 1137 } 1138 1139 1140 1141 static struct writequeue_entry *new_writequeue_entry(struct connection *con, 1142 gfp_t allocation) 1143 { 1144 struct writequeue_entry *entry; 1145 1146 entry = kmalloc(sizeof(struct writequeue_entry), allocation); 1147 if (!entry) 1148 return NULL; 1149 1150 entry->page = alloc_page(allocation); 1151 if (!entry->page) { 1152 kfree(entry); 1153 return NULL; 1154 } 1155 1156 entry->offset = 0; 1157 entry->len = 0; 1158 entry->end = 0; 1159 entry->users = 0; 1160 entry->con = con; 1161 1162 return entry; 1163 } 1164 1165 void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc) 1166 { 1167 struct connection *con; 1168 struct writequeue_entry *e; 1169 int offset = 0; 1170 int users = 0; 1171 1172 con = nodeid2con(nodeid, allocation); 1173 if (!con) 1174 return NULL; 1175 1176 spin_lock(&con->writequeue_lock); 1177 e = list_entry(con->writequeue.prev, struct writequeue_entry, list); 1178 if ((&e->list == &con->writequeue) || 1179 (PAGE_CACHE_SIZE - e->end < len)) { 1180 e = NULL; 1181 } else { 1182 offset = e->end; 1183 e->end += len; 1184 users = e->users++; 1185 } 1186 spin_unlock(&con->writequeue_lock); 1187 1188 if (e) { 1189 got_one: 1190 if (users == 0) 1191 kmap(e->page); 1192 *ppc = page_address(e->page) + offset; 1193 return e; 1194 } 1195 1196 e = new_writequeue_entry(con, allocation); 1197 if (e) { 1198 spin_lock(&con->writequeue_lock); 1199 offset = e->end; 1200 e->end += len; 1201 users = e->users++; 1202 list_add_tail(&e->list, &con->writequeue); 1203 spin_unlock(&con->writequeue_lock); 1204 goto got_one; 1205 } 1206 return NULL; 1207 } 1208 1209 void dlm_lowcomms_commit_buffer(void *mh) 1210 { 1211 struct writequeue_entry *e = (struct writequeue_entry *)mh; 1212 struct connection *con = e->con; 1213 int users; 1214 1215 spin_lock(&con->writequeue_lock); 1216 users = --e->users; 1217 if (users) 1218 goto out; 1219 e->len = e->end - e->offset; 1220 kunmap(e->page); 1221 spin_unlock(&con->writequeue_lock); 1222 1223 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) { 1224 queue_work(send_workqueue, &con->swork); 1225 } 1226 return; 1227 1228 out: 1229 spin_unlock(&con->writequeue_lock); 1230 return; 1231 } 1232 1233 /* Send a message */ 1234 static void send_to_sock(struct connection *con) 1235 { 1236 int ret = 0; 1237 ssize_t(*sendpage) (struct socket *, struct page *, int, size_t, int); 1238 const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL; 1239 struct writequeue_entry *e; 1240 int len, offset; 1241 1242 mutex_lock(&con->sock_mutex); 1243 if (con->sock == NULL) 1244 goto out_connect; 1245 1246 sendpage = con->sock->ops->sendpage; 1247 1248 spin_lock(&con->writequeue_lock); 1249 for (;;) { 1250 e = list_entry(con->writequeue.next, struct writequeue_entry, 1251 list); 1252 if ((struct list_head *) e == &con->writequeue) 1253 break; 1254 1255 len = e->len; 1256 offset = e->offset; 1257 BUG_ON(len == 0 && e->users == 0); 1258 spin_unlock(&con->writequeue_lock); 1259 kmap(e->page); 1260 1261 ret = 0; 1262 if (len) { 1263 ret = sendpage(con->sock, e->page, offset, len, 1264 msg_flags); 1265 if (ret == -EAGAIN || ret == 0) 1266 goto out; 1267 if (ret <= 0) 1268 goto send_error; 1269 } else { 1270 /* Don't starve people filling buffers */ 1271 cond_resched(); 1272 } 1273 1274 spin_lock(&con->writequeue_lock); 1275 e->offset += ret; 1276 e->len -= ret; 1277 1278 if (e->len == 0 && e->users == 0) { 1279 list_del(&e->list); 1280 kunmap(e->page); 1281 free_entry(e); 1282 continue; 1283 } 1284 } 1285 spin_unlock(&con->writequeue_lock); 1286 out: 1287 mutex_unlock(&con->sock_mutex); 1288 return; 1289 1290 send_error: 1291 mutex_unlock(&con->sock_mutex); 1292 close_connection(con, false); 1293 lowcomms_connect_sock(con); 1294 return; 1295 1296 out_connect: 1297 mutex_unlock(&con->sock_mutex); 1298 if (!test_bit(CF_INIT_PENDING, &con->flags)) 1299 lowcomms_connect_sock(con); 1300 return; 1301 } 1302 1303 static void clean_one_writequeue(struct connection *con) 1304 { 1305 struct list_head *list; 1306 struct list_head *temp; 1307 1308 spin_lock(&con->writequeue_lock); 1309 list_for_each_safe(list, temp, &con->writequeue) { 1310 struct writequeue_entry *e = 1311 list_entry(list, struct writequeue_entry, list); 1312 list_del(&e->list); 1313 free_entry(e); 1314 } 1315 spin_unlock(&con->writequeue_lock); 1316 } 1317 1318 /* Called from recovery when it knows that a node has 1319 left the cluster */ 1320 int dlm_lowcomms_close(int nodeid) 1321 { 1322 struct connection *con; 1323 1324 log_print("closing connection to node %d", nodeid); 1325 con = nodeid2con(nodeid, 0); 1326 if (con) { 1327 clean_one_writequeue(con); 1328 close_connection(con, true); 1329 } 1330 return 0; 1331 } 1332 1333 /* Receive workqueue function */ 1334 static void process_recv_sockets(struct work_struct *work) 1335 { 1336 struct connection *con = container_of(work, struct connection, rwork); 1337 int err; 1338 1339 clear_bit(CF_READ_PENDING, &con->flags); 1340 do { 1341 err = con->rx_action(con); 1342 } while (!err); 1343 } 1344 1345 /* Send workqueue function */ 1346 static void process_send_sockets(struct work_struct *work) 1347 { 1348 struct connection *con = container_of(work, struct connection, swork); 1349 1350 if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) { 1351 con->connect_action(con); 1352 } 1353 clear_bit(CF_WRITE_PENDING, &con->flags); 1354 send_to_sock(con); 1355 } 1356 1357 1358 /* Discard all entries on the write queues */ 1359 static void clean_writequeues(void) 1360 { 1361 int nodeid; 1362 1363 for (nodeid = 1; nodeid <= max_nodeid; nodeid++) { 1364 struct connection *con = __nodeid2con(nodeid, 0); 1365 1366 if (con) 1367 clean_one_writequeue(con); 1368 } 1369 } 1370 1371 static void work_stop(void) 1372 { 1373 destroy_workqueue(recv_workqueue); 1374 destroy_workqueue(send_workqueue); 1375 } 1376 1377 static int work_start(void) 1378 { 1379 int error; 1380 recv_workqueue = create_workqueue("dlm_recv"); 1381 error = IS_ERR(recv_workqueue); 1382 if (error) { 1383 log_print("can't start dlm_recv %d", error); 1384 return error; 1385 } 1386 1387 send_workqueue = create_singlethread_workqueue("dlm_send"); 1388 error = IS_ERR(send_workqueue); 1389 if (error) { 1390 log_print("can't start dlm_send %d", error); 1391 destroy_workqueue(recv_workqueue); 1392 return error; 1393 } 1394 1395 return 0; 1396 } 1397 1398 void dlm_lowcomms_stop(void) 1399 { 1400 int i; 1401 struct connection *con; 1402 1403 /* Set all the flags to prevent any 1404 socket activity. 1405 */ 1406 down(&connections_lock); 1407 for (i = 0; i <= max_nodeid; i++) { 1408 con = __nodeid2con(i, 0); 1409 if (con) { 1410 con->flags |= 0xFF; 1411 if (con->sock) 1412 con->sock->sk->sk_user_data = NULL; 1413 } 1414 } 1415 up(&connections_lock); 1416 1417 work_stop(); 1418 1419 down(&connections_lock); 1420 clean_writequeues(); 1421 1422 for (i = 0; i <= max_nodeid; i++) { 1423 con = __nodeid2con(i, 0); 1424 if (con) { 1425 close_connection(con, true); 1426 if (con->othercon) 1427 kmem_cache_free(con_cache, con->othercon); 1428 kmem_cache_free(con_cache, con); 1429 } 1430 } 1431 max_nodeid = 0; 1432 up(&connections_lock); 1433 kmem_cache_destroy(con_cache); 1434 idr_init(&connections_idr); 1435 } 1436 1437 int dlm_lowcomms_start(void) 1438 { 1439 int error = -EINVAL; 1440 struct connection *con; 1441 1442 init_local(); 1443 if (!dlm_local_count) { 1444 error = -ENOTCONN; 1445 log_print("no local IP address has been set"); 1446 goto out; 1447 } 1448 1449 error = -ENOMEM; 1450 con_cache = kmem_cache_create("dlm_conn", sizeof(struct connection), 1451 __alignof__(struct connection), 0, 1452 NULL, NULL); 1453 if (!con_cache) 1454 goto out; 1455 1456 /* Set some sysctl minima */ 1457 if (sysctl_rmem_max < NEEDED_RMEM) 1458 sysctl_rmem_max = NEEDED_RMEM; 1459 1460 /* Start listening */ 1461 if (dlm_config.ci_protocol == 0) 1462 error = tcp_listen_for_all(); 1463 else 1464 error = sctp_listen_for_all(); 1465 if (error) 1466 goto fail_unlisten; 1467 1468 error = work_start(); 1469 if (error) 1470 goto fail_unlisten; 1471 1472 return 0; 1473 1474 fail_unlisten: 1475 con = nodeid2con(0,0); 1476 if (con) { 1477 close_connection(con, false); 1478 kmem_cache_free(con_cache, con); 1479 } 1480 kmem_cache_destroy(con_cache); 1481 1482 out: 1483 return error; 1484 } 1485