blob: 5c33233bc2d59543633113cb5c1a31d042a9e133 [file] [log] [blame]
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001/******************************************************************************
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
63struct cbuf {
64 unsigned int base;
65 unsigned int len;
66 unsigned int mask;
67};
68
69static void cbuf_add(struct cbuf *cb, int n)
70{
71 cb->len += n;
72}
73
74static int cbuf_data(struct cbuf *cb)
75{
76 return ((cb->base + cb->len) & cb->mask);
77}
78
79static void cbuf_init(struct cbuf *cb, int size)
80{
81 cb->base = cb->len = 0;
82 cb->mask = size-1;
83}
84
85static void cbuf_eat(struct cbuf *cb, int n)
86{
87 cb->len -= n;
88 cb->base += n;
89 cb->base &= cb->mask;
90}
91
92static bool cbuf_empty(struct cbuf *cb)
93{
94 return cb->len == 0;
95}
96
97struct 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 */
123struct 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
133static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT];
134static int dlm_local_count;
135
136/* Work queues */
137static struct workqueue_struct *recv_workqueue;
138static struct workqueue_struct *send_workqueue;
139
140static DEFINE_IDR(connections_idr);
141static DECLARE_MUTEX(connections_lock);
142static int max_nodeid;
143static struct kmem_cache *con_cache;
144
145static void process_recv_sockets(struct work_struct *work);
146static 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 */
152static 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
204static 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 */
216static struct connection *assoc2con(int assoc_id)
217{
218 int i;
219 struct connection *con;
220
221 down(&connections_lock);
Patrick Caulfield30d3a232007-04-23 16:26:21 +0100222 for (i=0; i<=max_nodeid; i++) {
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100223 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
233static 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 */
260static void lowcomms_data_ready(struct sock *sk, int count_unused)
261{
262 struct connection *con = sock2con(sk);
263 if (!test_and_set_bit(CF_READ_PENDING, &con->flags))
264 queue_work(recv_workqueue, &con->rwork);
265}
266
267static void lowcomms_write_space(struct sock *sk)
268{
269 struct connection *con = sock2con(sk);
270
271 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags))
272 queue_work(send_workqueue, &con->swork);
273}
274
275static 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
281static 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 */
288static 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 */
302static 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 */
319static 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 */
340static 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 */
377static 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 */
398static void process_sctp_notification(struct connection *con, struct msghdr *msg, char *buf)
399{
400 union sctp_notification *sn = (union sctp_notification *)buf;
401
402 if (sn->sn_header.sn_type == SCTP_ASSOC_CHANGE) {
403 switch (sn->sn_assoc_change.sac_state) {
404
405 case SCTP_COMM_UP:
406 case SCTP_RESTART:
407 {
408 /* Check that the new node is in the lockspace */
409 struct sctp_prim prim;
410 int nodeid;
411 int prim_len, ret;
412 int addr_len;
413 struct connection *new_con;
414 struct file *file;
415 sctp_peeloff_arg_t parg;
416 int parglen = sizeof(parg);
417
418 /*
419 * We get this before any data for an association.
420 * We verify that the node is in the cluster and
421 * then peel off a socket for it.
422 */
423 if ((int)sn->sn_assoc_change.sac_assoc_id <= 0) {
424 log_print("COMM_UP for invalid assoc ID %d",
425 (int)sn->sn_assoc_change.sac_assoc_id);
426 sctp_init_failed();
427 return;
428 }
429 memset(&prim, 0, sizeof(struct sctp_prim));
430 prim_len = sizeof(struct sctp_prim);
431 prim.ssp_assoc_id = sn->sn_assoc_change.sac_assoc_id;
432
433 ret = kernel_getsockopt(con->sock,
434 IPPROTO_SCTP,
435 SCTP_PRIMARY_ADDR,
436 (char*)&prim,
437 &prim_len);
438 if (ret < 0) {
439 log_print("getsockopt/sctp_primary_addr on "
440 "new assoc %d failed : %d",
441 (int)sn->sn_assoc_change.sac_assoc_id,
442 ret);
443
444 /* Retry INIT later */
445 new_con = assoc2con(sn->sn_assoc_change.sac_assoc_id);
446 if (new_con)
447 clear_bit(CF_CONNECT_PENDING, &con->flags);
448 return;
449 }
450 make_sockaddr(&prim.ssp_addr, 0, &addr_len);
451 if (dlm_addr_to_nodeid(&prim.ssp_addr, &nodeid)) {
452 int i;
453 unsigned char *b=(unsigned char *)&prim.ssp_addr;
454 log_print("reject connect from unknown addr");
455 for (i=0; i<sizeof(struct sockaddr_storage);i++)
456 printk("%02x ", b[i]);
457 printk("\n");
458 sctp_send_shutdown(prim.ssp_assoc_id);
459 return;
460 }
461
462 new_con = nodeid2con(nodeid, GFP_KERNEL);
463 if (!new_con)
464 return;
465
466 /* Peel off a new sock */
467 parg.associd = sn->sn_assoc_change.sac_assoc_id;
468 ret = kernel_getsockopt(con->sock, IPPROTO_SCTP, SCTP_SOCKOPT_PEELOFF,
469 (void *)&parg, &parglen);
Patrick Caulfield30d3a232007-04-23 16:26:21 +0100470 if (ret) {
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100471 log_print("Can't peel off a socket for connection %d to node %d: err=%d\n",
472 parg.associd, nodeid, ret);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100473 }
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100474 file = fget(parg.sd);
475 new_con->sock = SOCKET_I(file->f_dentry->d_inode);
476 add_sock(new_con->sock, new_con);
477 fput(file);
478 put_unused_fd(parg.sd);
479
480 log_print("got new/restarted association %d nodeid %d",
481 (int)sn->sn_assoc_change.sac_assoc_id, nodeid);
482
483 /* Send any pending writes */
484 clear_bit(CF_CONNECT_PENDING, &new_con->flags);
485 clear_bit(CF_INIT_PENDING, &con->flags);
486 if (!test_and_set_bit(CF_WRITE_PENDING, &new_con->flags)) {
487 queue_work(send_workqueue, &new_con->swork);
488 }
489 if (!test_and_set_bit(CF_READ_PENDING, &new_con->flags))
490 queue_work(recv_workqueue, &new_con->rwork);
491 }
492 break;
493
494 case SCTP_COMM_LOST:
495 case SCTP_SHUTDOWN_COMP:
496 {
497 con = assoc2con(sn->sn_assoc_change.sac_assoc_id);
498 if (con) {
499 con->sctp_assoc = 0;
500 }
501 }
502 break;
503
504 /* We don't know which INIT failed, so clear the PENDING flags
505 * on them all. if assoc_id is zero then it will then try
506 * again */
507
508 case SCTP_CANT_STR_ASSOC:
509 {
510 log_print("Can't start SCTP association - retrying");
511 sctp_init_failed();
512 }
513 break;
514
515 default:
516 log_print("unexpected SCTP assoc change id=%d state=%d",
517 (int)sn->sn_assoc_change.sac_assoc_id,
518 sn->sn_assoc_change.sac_state);
519 }
520 }
521}
522
523/* Data received from remote end */
524static int receive_from_sock(struct connection *con)
525{
526 int ret = 0;
527 struct msghdr msg = {};
528 struct kvec iov[2];
529 unsigned len;
530 int r;
531 int call_again_soon = 0;
532 int nvec;
533 char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
534
535 mutex_lock(&con->sock_mutex);
536
537 if (con->sock == NULL) {
538 ret = -EAGAIN;
539 goto out_close;
540 }
541
542 if (con->rx_page == NULL) {
543 /*
544 * This doesn't need to be atomic, but I think it should
545 * improve performance if it is.
546 */
547 con->rx_page = alloc_page(GFP_ATOMIC);
548 if (con->rx_page == NULL)
549 goto out_resched;
550 cbuf_init(&con->cb, PAGE_CACHE_SIZE);
551 }
552
553 /* Only SCTP needs these really */
554 memset(&incmsg, 0, sizeof(incmsg));
555 msg.msg_control = incmsg;
556 msg.msg_controllen = sizeof(incmsg);
557
558 /*
559 * iov[0] is the bit of the circular buffer between the current end
560 * point (cb.base + cb.len) and the end of the buffer.
561 */
562 iov[0].iov_len = con->cb.base - cbuf_data(&con->cb);
563 iov[0].iov_base = page_address(con->rx_page) + cbuf_data(&con->cb);
564 iov[1].iov_len = 0;
565 nvec = 1;
566
567 /*
568 * iov[1] is the bit of the circular buffer between the start of the
569 * buffer and the start of the currently used section (cb.base)
570 */
571 if (cbuf_data(&con->cb) >= con->cb.base) {
572 iov[0].iov_len = PAGE_CACHE_SIZE - cbuf_data(&con->cb);
573 iov[1].iov_len = con->cb.base;
574 iov[1].iov_base = page_address(con->rx_page);
575 nvec = 2;
576 }
577 len = iov[0].iov_len + iov[1].iov_len;
578
579 r = ret = kernel_recvmsg(con->sock, &msg, iov, nvec, len,
580 MSG_DONTWAIT | MSG_NOSIGNAL);
581 if (ret <= 0)
582 goto out_close;
583
584 /* Process SCTP notifications */
585 if (msg.msg_flags & MSG_NOTIFICATION) {
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100586 msg.msg_control = incmsg;
587 msg.msg_controllen = sizeof(incmsg);
588
589 process_sctp_notification(con, &msg,
590 page_address(con->rx_page) + con->cb.base);
591 mutex_unlock(&con->sock_mutex);
592 return 0;
593 }
594 BUG_ON(con->nodeid == 0);
595
596 if (ret == len)
597 call_again_soon = 1;
598 cbuf_add(&con->cb, ret);
599 ret = dlm_process_incoming_buffer(con->nodeid,
600 page_address(con->rx_page),
601 con->cb.base, con->cb.len,
602 PAGE_CACHE_SIZE);
603 if (ret == -EBADMSG) {
604 printk(KERN_INFO "dlm: lowcomms: addr=%p, base=%u, len=%u, "
605 "iov_len=%u, iov_base[0]=%p, read=%d\n",
606 page_address(con->rx_page), con->cb.base, con->cb.len,
607 len, iov[0].iov_base, r);
608 }
609 if (ret < 0)
610 goto out_close;
611 cbuf_eat(&con->cb, ret);
612
613 if (cbuf_empty(&con->cb) && !call_again_soon) {
614 __free_page(con->rx_page);
615 con->rx_page = NULL;
616 }
617
618 if (call_again_soon)
619 goto out_resched;
620 mutex_unlock(&con->sock_mutex);
621 return 0;
622
623out_resched:
624 if (!test_and_set_bit(CF_READ_PENDING, &con->flags))
625 queue_work(recv_workqueue, &con->rwork);
626 mutex_unlock(&con->sock_mutex);
627 return -EAGAIN;
628
629out_close:
630 mutex_unlock(&con->sock_mutex);
631 if (ret != -EAGAIN && !test_bit(CF_IS_OTHERCON, &con->flags)) {
632 close_connection(con, false);
633 /* Reconnect when there is something to send */
634 }
635 /* Don't return success if we really got EOF */
636 if (ret == 0)
637 ret = -EAGAIN;
638
639 return ret;
640}
641
642/* Listening socket is busy, accept a connection */
643static int tcp_accept_from_sock(struct connection *con)
644{
645 int result;
646 struct sockaddr_storage peeraddr;
647 struct socket *newsock;
648 int len;
649 int nodeid;
650 struct connection *newcon;
651 struct connection *addcon;
652
653 memset(&peeraddr, 0, sizeof(peeraddr));
654 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM,
655 IPPROTO_TCP, &newsock);
656 if (result < 0)
657 return -ENOMEM;
658
659 mutex_lock_nested(&con->sock_mutex, 0);
660
661 result = -ENOTCONN;
662 if (con->sock == NULL)
663 goto accept_err;
664
665 newsock->type = con->sock->type;
666 newsock->ops = con->sock->ops;
667
668 result = con->sock->ops->accept(con->sock, newsock, O_NONBLOCK);
669 if (result < 0)
670 goto accept_err;
671
672 /* Get the connected socket's peer */
673 memset(&peeraddr, 0, sizeof(peeraddr));
674 if (newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr,
675 &len, 2)) {
676 result = -ECONNABORTED;
677 goto accept_err;
678 }
679
680 /* Get the new node's NODEID */
681 make_sockaddr(&peeraddr, 0, &len);
682 if (dlm_addr_to_nodeid(&peeraddr, &nodeid)) {
683 printk("dlm: connect from non cluster node\n");
684 sock_release(newsock);
685 mutex_unlock(&con->sock_mutex);
686 return -1;
687 }
688
689 log_print("got connection from %d", nodeid);
690
691 /* Check to see if we already have a connection to this node. This
692 * could happen if the two nodes initiate a connection at roughly
693 * the same time and the connections cross on the wire.
694 * In this case we store the incoming one in "othercon"
695 */
696 newcon = nodeid2con(nodeid, GFP_KERNEL);
697 if (!newcon) {
698 result = -ENOMEM;
699 goto accept_err;
700 }
701 mutex_lock_nested(&newcon->sock_mutex, 1);
702 if (newcon->sock) {
703 struct connection *othercon = newcon->othercon;
704
705 if (!othercon) {
706 othercon = kmem_cache_zalloc(con_cache, GFP_KERNEL);
707 if (!othercon) {
708 printk("dlm: failed to allocate incoming socket\n");
709 mutex_unlock(&newcon->sock_mutex);
710 result = -ENOMEM;
711 goto accept_err;
712 }
713 othercon->nodeid = nodeid;
714 othercon->rx_action = receive_from_sock;
715 mutex_init(&othercon->sock_mutex);
716 INIT_WORK(&othercon->swork, process_send_sockets);
717 INIT_WORK(&othercon->rwork, process_recv_sockets);
718 set_bit(CF_IS_OTHERCON, &othercon->flags);
719 newcon->othercon = othercon;
720 }
721 othercon->sock = newsock;
722 newsock->sk->sk_user_data = othercon;
723 add_sock(newsock, othercon);
724 addcon = othercon;
725 }
726 else {
727 newsock->sk->sk_user_data = newcon;
728 newcon->rx_action = receive_from_sock;
729 add_sock(newsock, newcon);
730 addcon = newcon;
731 }
732
733 mutex_unlock(&newcon->sock_mutex);
734
735 /*
736 * Add it to the active queue in case we got data
737 * beween processing the accept adding the socket
738 * to the read_sockets list
739 */
740 if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags))
741 queue_work(recv_workqueue, &addcon->rwork);
742 mutex_unlock(&con->sock_mutex);
743
744 return 0;
745
746accept_err:
747 mutex_unlock(&con->sock_mutex);
748 sock_release(newsock);
749
750 if (result != -EAGAIN)
751 printk("dlm: error accepting connection from node: %d\n", result);
752 return result;
753}
754
755static void free_entry(struct writequeue_entry *e)
756{
757 __free_page(e->page);
758 kfree(e);
759}
760
761/* Initiate an SCTP association.
762 This is a special case of send_to_sock() in that we don't yet have a
763 peeled-off socket for this association, so we use the listening socket
764 and add the primary IP address of the remote node.
765 */
766static void sctp_init_assoc(struct connection *con)
767{
768 struct sockaddr_storage rem_addr;
769 char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
770 struct msghdr outmessage;
771 struct cmsghdr *cmsg;
772 struct sctp_sndrcvinfo *sinfo;
773 struct connection *base_con;
774 struct writequeue_entry *e;
775 int len, offset;
776 int ret;
777 int addrlen;
778 struct kvec iov[1];
779
780 if (test_and_set_bit(CF_INIT_PENDING, &con->flags))
781 return;
782
783 if (con->retries++ > MAX_CONNECT_RETRIES)
784 return;
785
786 log_print("Initiating association with node %d", con->nodeid);
787
788 if (nodeid_to_addr(con->nodeid, (struct sockaddr *)&rem_addr)) {
789 log_print("no address for nodeid %d", con->nodeid);
790 return;
791 }
792 base_con = nodeid2con(0, 0);
793 BUG_ON(base_con == NULL);
794
795 make_sockaddr(&rem_addr, dlm_config.ci_tcp_port, &addrlen);
796
797 outmessage.msg_name = &rem_addr;
798 outmessage.msg_namelen = addrlen;
799 outmessage.msg_control = outcmsg;
800 outmessage.msg_controllen = sizeof(outcmsg);
801 outmessage.msg_flags = MSG_EOR;
802
803 spin_lock(&con->writequeue_lock);
804 e = list_entry(con->writequeue.next, struct writequeue_entry,
805 list);
806
807 BUG_ON((struct list_head *) e == &con->writequeue);
808
809 len = e->len;
810 offset = e->offset;
811 spin_unlock(&con->writequeue_lock);
812 kmap(e->page);
813
814 /* Send the first block off the write queue */
815 iov[0].iov_base = page_address(e->page)+offset;
816 iov[0].iov_len = len;
817
818 cmsg = CMSG_FIRSTHDR(&outmessage);
819 cmsg->cmsg_level = IPPROTO_SCTP;
820 cmsg->cmsg_type = SCTP_SNDRCV;
821 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
822 sinfo = CMSG_DATA(cmsg);
823 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo));
824 sinfo->sinfo_ppid = cpu_to_le32(dlm_our_nodeid());
825 outmessage.msg_controllen = cmsg->cmsg_len;
826
827 ret = kernel_sendmsg(base_con->sock, &outmessage, iov, 1, len);
828 if (ret < 0) {
829 log_print("Send first packet to node %d failed: %d", con->nodeid, ret);
830
831 /* Try again later */
832 clear_bit(CF_CONNECT_PENDING, &con->flags);
833 clear_bit(CF_INIT_PENDING, &con->flags);
834 }
835 else {
836 spin_lock(&con->writequeue_lock);
837 e->offset += ret;
838 e->len -= ret;
839
840 if (e->len == 0 && e->users == 0) {
841 list_del(&e->list);
842 kunmap(e->page);
843 free_entry(e);
844 }
845 spin_unlock(&con->writequeue_lock);
846 }
847}
848
849/* Connect a new socket to its peer */
850static void tcp_connect_to_sock(struct connection *con)
851{
852 int result = -EHOSTUNREACH;
853 struct sockaddr_storage saddr;
854 int addr_len;
855 struct socket *sock;
856
857 if (con->nodeid == 0) {
858 log_print("attempt to connect sock 0 foiled");
859 return;
860 }
861
862 mutex_lock(&con->sock_mutex);
863 if (con->retries++ > MAX_CONNECT_RETRIES)
864 goto out;
865
866 /* Some odd races can cause double-connects, ignore them */
867 if (con->sock) {
868 result = 0;
869 goto out;
870 }
871
872 /* Create a socket to communicate with */
873 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM,
874 IPPROTO_TCP, &sock);
875 if (result < 0)
876 goto out_err;
877
878 memset(&saddr, 0, sizeof(saddr));
879 if (dlm_nodeid_to_addr(con->nodeid, &saddr))
880 goto out_err;
881
882 sock->sk->sk_user_data = con;
883 con->rx_action = receive_from_sock;
884 con->connect_action = tcp_connect_to_sock;
885 add_sock(sock, con);
886
887 make_sockaddr(&saddr, dlm_config.ci_tcp_port, &addr_len);
888
889 log_print("connecting to %d", con->nodeid);
890 result =
891 sock->ops->connect(sock, (struct sockaddr *)&saddr, addr_len,
892 O_NONBLOCK);
893 if (result == -EINPROGRESS)
894 result = 0;
895 if (result == 0)
896 goto out;
897
898out_err:
899 if (con->sock) {
900 sock_release(con->sock);
901 con->sock = NULL;
902 }
903 /*
904 * Some errors are fatal and this list might need adjusting. For other
905 * errors we try again until the max number of retries is reached.
906 */
907 if (result != -EHOSTUNREACH && result != -ENETUNREACH &&
908 result != -ENETDOWN && result != EINVAL
909 && result != -EPROTONOSUPPORT) {
910 lowcomms_connect_sock(con);
911 result = 0;
912 }
913out:
914 mutex_unlock(&con->sock_mutex);
915 return;
916}
917
918static struct socket *tcp_create_listen_sock(struct connection *con,
919 struct sockaddr_storage *saddr)
920{
921 struct socket *sock = NULL;
922 int result = 0;
923 int one = 1;
924 int addr_len;
925
926 if (dlm_local_addr[0]->ss_family == AF_INET)
927 addr_len = sizeof(struct sockaddr_in);
928 else
929 addr_len = sizeof(struct sockaddr_in6);
930
931 /* Create a socket to communicate with */
932 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, IPPROTO_TCP, &sock);
933 if (result < 0) {
934 printk("dlm: Can't create listening comms socket\n");
935 goto create_out;
936 }
937
938 result = kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
939 (char *)&one, sizeof(one));
940
941 if (result < 0) {
942 printk("dlm: Failed to set SO_REUSEADDR on socket: result=%d\n",
943 result);
944 }
945 sock->sk->sk_user_data = con;
946 con->rx_action = tcp_accept_from_sock;
947 con->connect_action = tcp_connect_to_sock;
948 con->sock = sock;
949
950 /* Bind to our port */
951 make_sockaddr(saddr, dlm_config.ci_tcp_port, &addr_len);
952 result = sock->ops->bind(sock, (struct sockaddr *) saddr, addr_len);
953 if (result < 0) {
954 printk("dlm: Can't bind to port %d\n", dlm_config.ci_tcp_port);
955 sock_release(sock);
956 sock = NULL;
957 con->sock = NULL;
958 goto create_out;
959 }
960 result = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
961 (char *)&one, sizeof(one));
962 if (result < 0) {
963 printk("dlm: Set keepalive failed: %d\n", result);
964 }
965
966 result = sock->ops->listen(sock, 5);
967 if (result < 0) {
968 printk("dlm: Can't listen on port %d\n", dlm_config.ci_tcp_port);
969 sock_release(sock);
970 sock = NULL;
971 goto create_out;
972 }
973
974create_out:
975 return sock;
976}
977
978/* Get local addresses */
979static void init_local(void)
980{
981 struct sockaddr_storage sas, *addr;
982 int i;
983
Patrick Caulfield30d3a232007-04-23 16:26:21 +0100984 dlm_local_count = 0;
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100985 for (i = 0; i < DLM_MAX_ADDR_COUNT - 1; i++) {
986 if (dlm_our_addr(&sas, i))
987 break;
988
989 addr = kmalloc(sizeof(*addr), GFP_KERNEL);
990 if (!addr)
991 break;
992 memcpy(addr, &sas, sizeof(*addr));
993 dlm_local_addr[dlm_local_count++] = addr;
994 }
995}
996
997/* Bind to an IP address. SCTP allows multiple address so it can do multi-homing */
998static int add_sctp_bind_addr(struct connection *sctp_con, struct sockaddr_storage *addr, int addr_len, int num)
999{
1000 int result = 0;
1001
1002 if (num == 1)
1003 result = kernel_bind(sctp_con->sock,
1004 (struct sockaddr *) addr,
1005 addr_len);
1006 else
1007 result = kernel_setsockopt(sctp_con->sock, SOL_SCTP,
1008 SCTP_SOCKOPT_BINDX_ADD,
1009 (char *)addr, addr_len);
1010
1011 if (result < 0)
1012 log_print("Can't bind to port %d addr number %d",
1013 dlm_config.ci_tcp_port, num);
1014
1015 return result;
1016}
1017
1018/* Initialise SCTP socket and bind to all interfaces */
1019static int sctp_listen_for_all(void)
1020{
1021 struct socket *sock = NULL;
1022 struct sockaddr_storage localaddr;
1023 struct sctp_event_subscribe subscribe;
1024 int result = -EINVAL, num = 1, i, addr_len;
1025 struct connection *con = nodeid2con(0, GFP_KERNEL);
1026 int bufsize = NEEDED_RMEM;
1027
1028 if (!con)
1029 return -ENOMEM;
1030
1031 log_print("Using SCTP for communications");
1032
1033 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_SEQPACKET,
1034 IPPROTO_SCTP, &sock);
1035 if (result < 0) {
1036 log_print("Can't create comms socket, check SCTP is loaded");
1037 goto out;
1038 }
1039
1040 /* Listen for events */
1041 memset(&subscribe, 0, sizeof(subscribe));
1042 subscribe.sctp_data_io_event = 1;
1043 subscribe.sctp_association_event = 1;
1044 subscribe.sctp_send_failure_event = 1;
1045 subscribe.sctp_shutdown_event = 1;
1046 subscribe.sctp_partial_delivery_event = 1;
1047
1048 result = kernel_setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
1049 (char *)&bufsize, sizeof(bufsize));
1050 if (result)
1051 log_print("Error increasing buffer space on socket: %d", result);
1052
1053 result = kernel_setsockopt(sock, SOL_SCTP, SCTP_EVENTS,
1054 (char *)&subscribe, sizeof(subscribe));
1055 if (result < 0) {
1056 log_print("Failed to set SCTP_EVENTS on socket: result=%d",
1057 result);
1058 goto create_delsock;
1059 }
1060
1061 /* Init con struct */
1062 sock->sk->sk_user_data = con;
1063 con->sock = sock;
1064 con->sock->sk->sk_data_ready = lowcomms_data_ready;
1065 con->rx_action = receive_from_sock;
1066 con->connect_action = sctp_init_assoc;
1067
1068 /* Bind to all interfaces. */
1069 for (i = 0; i < dlm_local_count; i++) {
1070 memcpy(&localaddr, dlm_local_addr[i], sizeof(localaddr));
1071 make_sockaddr(&localaddr, dlm_config.ci_tcp_port, &addr_len);
1072
1073 result = add_sctp_bind_addr(con, &localaddr, addr_len, num);
1074 if (result)
1075 goto create_delsock;
1076 ++num;
1077 }
1078
1079 result = sock->ops->listen(sock, 5);
1080 if (result < 0) {
1081 log_print("Can't set socket listening");
1082 goto create_delsock;
1083 }
1084
1085 return 0;
1086
1087create_delsock:
1088 sock_release(sock);
1089 con->sock = NULL;
1090out:
1091 return result;
1092}
1093
1094static int tcp_listen_for_all(void)
1095{
1096 struct socket *sock = NULL;
1097 struct connection *con = nodeid2con(0, GFP_KERNEL);
1098 int result = -EINVAL;
1099
1100 if (!con)
1101 return -ENOMEM;
1102
1103 /* We don't support multi-homed hosts */
1104 if (dlm_local_addr[1] != NULL) {
1105 log_print("TCP protocol can't handle multi-homed hosts, try SCTP");
1106 return -EINVAL;
1107 }
1108
1109 log_print("Using TCP for communications");
1110
1111 set_bit(CF_IS_OTHERCON, &con->flags);
1112
1113 sock = tcp_create_listen_sock(con, dlm_local_addr[0]);
1114 if (sock) {
1115 add_sock(sock, con);
1116 result = 0;
1117 }
1118 else {
1119 result = -EADDRINUSE;
1120 }
1121
1122 return result;
1123}
1124
1125
1126
1127static struct writequeue_entry *new_writequeue_entry(struct connection *con,
1128 gfp_t allocation)
1129{
1130 struct writequeue_entry *entry;
1131
1132 entry = kmalloc(sizeof(struct writequeue_entry), allocation);
1133 if (!entry)
1134 return NULL;
1135
1136 entry->page = alloc_page(allocation);
1137 if (!entry->page) {
1138 kfree(entry);
1139 return NULL;
1140 }
1141
1142 entry->offset = 0;
1143 entry->len = 0;
1144 entry->end = 0;
1145 entry->users = 0;
1146 entry->con = con;
1147
1148 return entry;
1149}
1150
1151void *dlm_lowcomms_get_buffer(int nodeid, int len,
1152 gfp_t allocation, char **ppc)
1153{
1154 struct connection *con;
1155 struct writequeue_entry *e;
1156 int offset = 0;
1157 int users = 0;
1158
1159 con = nodeid2con(nodeid, allocation);
1160 if (!con)
1161 return NULL;
1162
1163 spin_lock(&con->writequeue_lock);
1164 e = list_entry(con->writequeue.prev, struct writequeue_entry, list);
1165 if ((&e->list == &con->writequeue) ||
1166 (PAGE_CACHE_SIZE - e->end < len)) {
1167 e = NULL;
1168 } else {
1169 offset = e->end;
1170 e->end += len;
1171 users = e->users++;
1172 }
1173 spin_unlock(&con->writequeue_lock);
1174
1175 if (e) {
1176 got_one:
1177 if (users == 0)
1178 kmap(e->page);
1179 *ppc = page_address(e->page) + offset;
1180 return e;
1181 }
1182
1183 e = new_writequeue_entry(con, allocation);
1184 if (e) {
1185 spin_lock(&con->writequeue_lock);
1186 offset = e->end;
1187 e->end += len;
1188 users = e->users++;
1189 list_add_tail(&e->list, &con->writequeue);
1190 spin_unlock(&con->writequeue_lock);
1191 goto got_one;
1192 }
1193 return NULL;
1194}
1195
1196void dlm_lowcomms_commit_buffer(void *mh)
1197{
1198 struct writequeue_entry *e = (struct writequeue_entry *)mh;
1199 struct connection *con = e->con;
1200 int users;
1201
1202 spin_lock(&con->writequeue_lock);
1203 users = --e->users;
1204 if (users)
1205 goto out;
1206 e->len = e->end - e->offset;
1207 kunmap(e->page);
1208 spin_unlock(&con->writequeue_lock);
1209
1210 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) {
1211 queue_work(send_workqueue, &con->swork);
1212 }
1213 return;
1214
1215out:
1216 spin_unlock(&con->writequeue_lock);
1217 return;
1218}
1219
1220/* Send a message */
1221static void send_to_sock(struct connection *con)
1222{
1223 int ret = 0;
1224 ssize_t(*sendpage) (struct socket *, struct page *, int, size_t, int);
1225 const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
1226 struct writequeue_entry *e;
1227 int len, offset;
1228
1229 mutex_lock(&con->sock_mutex);
1230 if (con->sock == NULL)
1231 goto out_connect;
1232
1233 sendpage = con->sock->ops->sendpage;
1234
1235 spin_lock(&con->writequeue_lock);
1236 for (;;) {
1237 e = list_entry(con->writequeue.next, struct writequeue_entry,
1238 list);
1239 if ((struct list_head *) e == &con->writequeue)
1240 break;
1241
1242 len = e->len;
1243 offset = e->offset;
1244 BUG_ON(len == 0 && e->users == 0);
1245 spin_unlock(&con->writequeue_lock);
1246 kmap(e->page);
1247
1248 ret = 0;
1249 if (len) {
1250 ret = sendpage(con->sock, e->page, offset, len,
1251 msg_flags);
1252 if (ret == -EAGAIN || ret == 0)
1253 goto out;
1254 if (ret <= 0)
1255 goto send_error;
1256 }
1257 else {
1258 /* Don't starve people filling buffers */
1259 cond_resched();
1260 }
1261
1262 spin_lock(&con->writequeue_lock);
1263 e->offset += ret;
1264 e->len -= ret;
1265
1266 if (e->len == 0 && e->users == 0) {
1267 list_del(&e->list);
1268 kunmap(e->page);
1269 free_entry(e);
1270 continue;
1271 }
1272 }
1273 spin_unlock(&con->writequeue_lock);
1274out:
1275 mutex_unlock(&con->sock_mutex);
1276 return;
1277
1278send_error:
1279 mutex_unlock(&con->sock_mutex);
1280 close_connection(con, false);
1281 lowcomms_connect_sock(con);
1282 return;
1283
1284out_connect:
1285 mutex_unlock(&con->sock_mutex);
1286 if (!test_bit(CF_INIT_PENDING, &con->flags))
1287 lowcomms_connect_sock(con);
1288 return;
1289}
1290
1291static void clean_one_writequeue(struct connection *con)
1292{
1293 struct list_head *list;
1294 struct list_head *temp;
1295
1296 spin_lock(&con->writequeue_lock);
1297 list_for_each_safe(list, temp, &con->writequeue) {
1298 struct writequeue_entry *e =
1299 list_entry(list, struct writequeue_entry, list);
1300 list_del(&e->list);
1301 free_entry(e);
1302 }
1303 spin_unlock(&con->writequeue_lock);
1304}
1305
1306/* Called from recovery when it knows that a node has
1307 left the cluster */
1308int dlm_lowcomms_close(int nodeid)
1309{
1310 struct connection *con;
1311
1312 log_print("closing connection to node %d", nodeid);
1313 con = nodeid2con(nodeid, 0);
1314 if (con) {
1315 clean_one_writequeue(con);
1316 close_connection(con, true);
1317 }
1318 return 0;
1319}
1320
1321/* Receive workqueue function */
1322static void process_recv_sockets(struct work_struct *work)
1323{
1324 struct connection *con = container_of(work, struct connection, rwork);
1325 int err;
1326
1327 clear_bit(CF_READ_PENDING, &con->flags);
1328 do {
1329 err = con->rx_action(con);
1330 } while (!err);
1331}
1332
1333/* Send workqueue function */
1334static void process_send_sockets(struct work_struct *work)
1335{
1336 struct connection *con = container_of(work, struct connection, swork);
1337
1338 if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) {
1339 con->connect_action(con);
1340 }
1341 clear_bit(CF_WRITE_PENDING, &con->flags);
1342 send_to_sock(con);
1343}
1344
1345
1346/* Discard all entries on the write queues */
1347static void clean_writequeues(void)
1348{
1349 int nodeid;
1350
Patrick Caulfield30d3a232007-04-23 16:26:21 +01001351 for (nodeid = 1; nodeid <= max_nodeid; nodeid++) {
1352 struct connection *con = __nodeid2con(nodeid, 0);
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001353
1354 if (con)
1355 clean_one_writequeue(con);
1356 }
1357}
1358
1359static void work_stop(void)
1360{
1361 destroy_workqueue(recv_workqueue);
1362 destroy_workqueue(send_workqueue);
1363}
1364
1365static int work_start(void)
1366{
1367 int error;
1368 recv_workqueue = create_workqueue("dlm_recv");
1369 error = IS_ERR(recv_workqueue);
1370 if (error) {
1371 log_print("can't start dlm_recv %d", error);
1372 return error;
1373 }
1374
1375 send_workqueue = create_singlethread_workqueue("dlm_send");
1376 error = IS_ERR(send_workqueue);
1377 if (error) {
1378 log_print("can't start dlm_send %d", error);
1379 destroy_workqueue(recv_workqueue);
1380 return error;
1381 }
1382
1383 return 0;
1384}
1385
1386void dlm_lowcomms_stop(void)
1387{
1388 int i;
1389 struct connection *con;
1390
1391 /* Set all the flags to prevent any
1392 socket activity.
1393 */
1394 down(&connections_lock);
Patrick Caulfield30d3a232007-04-23 16:26:21 +01001395 for (i = 0; i <= max_nodeid; i++) {
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001396 con = __nodeid2con(i, 0);
1397 if (con)
1398 con->flags |= 0xFF;
1399 }
1400 up(&connections_lock);
1401
1402 work_stop();
1403
1404 down(&connections_lock);
1405 clean_writequeues();
1406
Patrick Caulfield30d3a232007-04-23 16:26:21 +01001407 for (i = 0; i <= max_nodeid; i++) {
Josef Bacik2439fe52007-04-19 17:59:05 -04001408 con = __nodeid2con(i, 0);
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001409 if (con) {
1410 close_connection(con, true);
1411 if (con->othercon)
1412 kmem_cache_free(con_cache, con->othercon);
1413 kmem_cache_free(con_cache, con);
1414 }
1415 }
Patrick Caulfield30d3a232007-04-23 16:26:21 +01001416 max_nodeid = 0;
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001417 up(&connections_lock);
1418 kmem_cache_destroy(con_cache);
Patrick Caulfield30d3a232007-04-23 16:26:21 +01001419 idr_init(&connections_idr);
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001420}
1421
1422int dlm_lowcomms_start(void)
1423{
1424 int error = -EINVAL;
1425 struct connection *con;
1426
1427 init_local();
1428 if (!dlm_local_count) {
1429 log_print("no local IP address has been set");
1430 goto out;
1431 }
1432
1433 error = -ENOMEM;
1434 con_cache = kmem_cache_create("dlm_conn", sizeof(struct connection),
1435 __alignof__(struct connection), 0,
1436 NULL, NULL);
1437 if (!con_cache)
1438 goto out;
1439
1440 /* Set some sysctl minima */
1441 if (sysctl_rmem_max < NEEDED_RMEM)
1442 sysctl_rmem_max = NEEDED_RMEM;
1443
1444 /* Start listening */
1445 if (dlm_config.ci_protocol == 0)
1446 error = tcp_listen_for_all();
1447 else
1448 error = sctp_listen_for_all();
1449 if (error)
1450 goto fail_unlisten;
1451
1452 error = work_start();
1453 if (error)
1454 goto fail_unlisten;
1455
1456 return 0;
1457
1458fail_unlisten:
1459 con = nodeid2con(0,0);
1460 if (con) {
1461 close_connection(con, false);
1462 kmem_cache_free(con_cache, con);
1463 }
1464 kmem_cache_destroy(con_cache);
1465
1466out:
1467 return error;
1468}