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-rw-r--r--fs/dlm/lowcomms-sctp.c1227
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diff --git a/fs/dlm/lowcomms-sctp.c b/fs/dlm/lowcomms-sctp.c
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index 000000000000..fe158d7a9285
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+++ b/fs/dlm/lowcomms-sctp.c
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1/******************************************************************************
2*******************************************************************************
3**
4** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
5** Copyright (C) 2004-2006 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 * I don't see any problem with the recv thread executing the locking
40 * code on behalf of remote processes as the locking code is
41 * short, efficient and never (well, hardly ever) waits.
42 *
43 */
44
45#include <asm/ioctls.h>
46#include <net/sock.h>
47#include <net/tcp.h>
48#include <net/sctp/user.h>
49#include <linux/pagemap.h>
50#include <linux/socket.h>
51#include <linux/idr.h>
52
53#include "dlm_internal.h"
54#include "lowcomms.h"
55#include "config.h"
56#include "midcomms.h"
57
58static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT];
59static int dlm_local_count;
60static int dlm_local_nodeid;
61
62/* One of these per connected node */
63
64#define NI_INIT_PENDING 1
65#define NI_WRITE_PENDING 2
66
67struct nodeinfo {
68 spinlock_t lock;
69 sctp_assoc_t assoc_id;
70 unsigned long flags;
71 struct list_head write_list; /* nodes with pending writes */
72 struct list_head writequeue; /* outgoing writequeue_entries */
73 spinlock_t writequeue_lock;
74 int nodeid;
75};
76
77static DEFINE_IDR(nodeinfo_idr);
78static DECLARE_RWSEM(nodeinfo_lock);
79static int max_nodeid;
80
81struct cbuf {
82 unsigned int base;
83 unsigned int len;
84 unsigned int mask;
85};
86
87/* Just the one of these, now. But this struct keeps
88 the connection-specific variables together */
89
90#define CF_READ_PENDING 1
91
92struct connection {
93 struct socket *sock;
94 unsigned long flags;
95 struct page *rx_page;
96 atomic_t waiting_requests;
97 struct cbuf cb;
98 int eagain_flag;
99};
100
101/* An entry waiting to be sent */
102
103struct writequeue_entry {
104 struct list_head list;
105 struct page *page;
106 int offset;
107 int len;
108 int end;
109 int users;
110 struct nodeinfo *ni;
111};
112
113static void cbuf_add(struct cbuf *cb, int n)
114{
115 cb->len += n;
116}
117
118static int cbuf_data(struct cbuf *cb)
119{
120 return ((cb->base + cb->len) & cb->mask);
121}
122
123static void cbuf_init(struct cbuf *cb, int size)
124{
125 cb->base = cb->len = 0;
126 cb->mask = size-1;
127}
128
129static void cbuf_eat(struct cbuf *cb, int n)
130{
131 cb->len -= n;
132 cb->base += n;
133 cb->base &= cb->mask;
134}
135
136/* List of nodes which have writes pending */
137static LIST_HEAD(write_nodes);
138static DEFINE_SPINLOCK(write_nodes_lock);
139
140/* Maximum number of incoming messages to process before
141 * doing a schedule()
142 */
143#define MAX_RX_MSG_COUNT 25
144
145/* Manage daemons */
146static struct task_struct *recv_task;
147static struct task_struct *send_task;
148static DECLARE_WAIT_QUEUE_HEAD(lowcomms_recv_wait);
149
150/* The SCTP connection */
151static struct connection sctp_con;
152
153
154static int nodeid_to_addr(int nodeid, struct sockaddr *retaddr)
155{
156 struct sockaddr_storage addr;
157 int error;
158
159 if (!dlm_local_count)
160 return -1;
161
162 error = dlm_nodeid_to_addr(nodeid, &addr);
163 if (error)
164 return error;
165
166 if (dlm_local_addr[0]->ss_family == AF_INET) {
167 struct sockaddr_in *in4 = (struct sockaddr_in *) &addr;
168 struct sockaddr_in *ret4 = (struct sockaddr_in *) retaddr;
169 ret4->sin_addr.s_addr = in4->sin_addr.s_addr;
170 } else {
171 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) &addr;
172 struct sockaddr_in6 *ret6 = (struct sockaddr_in6 *) retaddr;
173 memcpy(&ret6->sin6_addr, &in6->sin6_addr,
174 sizeof(in6->sin6_addr));
175 }
176
177 return 0;
178}
179
180/* If alloc is 0 here we will not attempt to allocate a new
181 nodeinfo struct */
182static struct nodeinfo *nodeid2nodeinfo(int nodeid, gfp_t alloc)
183{
184 struct nodeinfo *ni;
185 int r;
186 int n;
187
188 down_read(&nodeinfo_lock);
189 ni = idr_find(&nodeinfo_idr, nodeid);
190 up_read(&nodeinfo_lock);
191
192 if (ni || !alloc)
193 return ni;
194
195 down_write(&nodeinfo_lock);
196
197 ni = idr_find(&nodeinfo_idr, nodeid);
198 if (ni)
199 goto out_up;
200
201 r = idr_pre_get(&nodeinfo_idr, alloc);
202 if (!r)
203 goto out_up;
204
205 ni = kmalloc(sizeof(struct nodeinfo), alloc);
206 if (!ni)
207 goto out_up;
208
209 r = idr_get_new_above(&nodeinfo_idr, ni, nodeid, &n);
210 if (r) {
211 kfree(ni);
212 ni = NULL;
213 goto out_up;
214 }
215 if (n != nodeid) {
216 idr_remove(&nodeinfo_idr, n);
217 kfree(ni);
218 ni = NULL;
219 goto out_up;
220 }
221 memset(ni, 0, sizeof(struct nodeinfo));
222 spin_lock_init(&ni->lock);
223 INIT_LIST_HEAD(&ni->writequeue);
224 spin_lock_init(&ni->writequeue_lock);
225 ni->nodeid = nodeid;
226
227 if (nodeid > max_nodeid)
228 max_nodeid = nodeid;
229out_up:
230 up_write(&nodeinfo_lock);
231
232 return ni;
233}
234
235/* Don't call this too often... */
236static struct nodeinfo *assoc2nodeinfo(sctp_assoc_t assoc)
237{
238 int i;
239 struct nodeinfo *ni;
240
241 for (i=1; i<=max_nodeid; i++) {
242 ni = nodeid2nodeinfo(i, 0);
243 if (ni && ni->assoc_id == assoc)
244 return ni;
245 }
246 return NULL;
247}
248
249/* Data or notification available on socket */
250static void lowcomms_data_ready(struct sock *sk, int count_unused)
251{
252 atomic_inc(&sctp_con.waiting_requests);
253 if (test_and_set_bit(CF_READ_PENDING, &sctp_con.flags))
254 return;
255
256 wake_up_interruptible(&lowcomms_recv_wait);
257}
258
259
260/* Add the port number to an IP6 or 4 sockaddr and return the address length.
261 Also padd out the struct with zeros to make comparisons meaningful */
262
263static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port,
264 int *addr_len)
265{
266 struct sockaddr_in *local4_addr;
267 struct sockaddr_in6 *local6_addr;
268
269 if (!dlm_local_count)
270 return;
271
272 if (!port) {
273 if (dlm_local_addr[0]->ss_family == AF_INET) {
274 local4_addr = (struct sockaddr_in *)dlm_local_addr[0];
275 port = be16_to_cpu(local4_addr->sin_port);
276 } else {
277 local6_addr = (struct sockaddr_in6 *)dlm_local_addr[0];
278 port = be16_to_cpu(local6_addr->sin6_port);
279 }
280 }
281
282 saddr->ss_family = dlm_local_addr[0]->ss_family;
283 if (dlm_local_addr[0]->ss_family == AF_INET) {
284 struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr;
285 in4_addr->sin_port = cpu_to_be16(port);
286 memset(&in4_addr->sin_zero, 0, sizeof(in4_addr->sin_zero));
287 memset(in4_addr+1, 0, sizeof(struct sockaddr_storage) -
288 sizeof(struct sockaddr_in));
289 *addr_len = sizeof(struct sockaddr_in);
290 } else {
291 struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr;
292 in6_addr->sin6_port = cpu_to_be16(port);
293 memset(in6_addr+1, 0, sizeof(struct sockaddr_storage) -
294 sizeof(struct sockaddr_in6));
295 *addr_len = sizeof(struct sockaddr_in6);
296 }
297}
298
299/* Close the connection and tidy up */
300static void close_connection(void)
301{
302 if (sctp_con.sock) {
303 sock_release(sctp_con.sock);
304 sctp_con.sock = NULL;
305 }
306
307 if (sctp_con.rx_page) {
308 __free_page(sctp_con.rx_page);
309 sctp_con.rx_page = NULL;
310 }
311}
312
313/* We only send shutdown messages to nodes that are not part of the cluster */
314static void send_shutdown(sctp_assoc_t associd)
315{
316 static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
317 struct msghdr outmessage;
318 struct cmsghdr *cmsg;
319 struct sctp_sndrcvinfo *sinfo;
320 int ret;
321
322 outmessage.msg_name = NULL;
323 outmessage.msg_namelen = 0;
324 outmessage.msg_control = outcmsg;
325 outmessage.msg_controllen = sizeof(outcmsg);
326 outmessage.msg_flags = MSG_EOR;
327
328 cmsg = CMSG_FIRSTHDR(&outmessage);
329 cmsg->cmsg_level = IPPROTO_SCTP;
330 cmsg->cmsg_type = SCTP_SNDRCV;
331 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
332 outmessage.msg_controllen = cmsg->cmsg_len;
333 sinfo = CMSG_DATA(cmsg);
334 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo));
335
336 sinfo->sinfo_flags |= MSG_EOF;
337 sinfo->sinfo_assoc_id = associd;
338
339 ret = kernel_sendmsg(sctp_con.sock, &outmessage, NULL, 0, 0);
340
341 if (ret != 0)
342 log_print("send EOF to node failed: %d", ret);
343}
344
345
346/* INIT failed but we don't know which node...
347 restart INIT on all pending nodes */
348static void init_failed(void)
349{
350 int i;
351 struct nodeinfo *ni;
352
353 for (i=1; i<=max_nodeid; i++) {
354 ni = nodeid2nodeinfo(i, 0);
355 if (!ni)
356 continue;
357
358 if (test_and_clear_bit(NI_INIT_PENDING, &ni->flags)) {
359 ni->assoc_id = 0;
360 if (!test_and_set_bit(NI_WRITE_PENDING, &ni->flags)) {
361 spin_lock_bh(&write_nodes_lock);
362 list_add_tail(&ni->write_list, &write_nodes);
363 spin_unlock_bh(&write_nodes_lock);
364 }
365 }
366 }
367 wake_up_process(send_task);
368}
369
370/* Something happened to an association */
371static void process_sctp_notification(struct msghdr *msg, char *buf)
372{
373 union sctp_notification *sn = (union sctp_notification *)buf;
374
375 if (sn->sn_header.sn_type == SCTP_ASSOC_CHANGE) {
376 switch (sn->sn_assoc_change.sac_state) {
377
378 case SCTP_COMM_UP:
379 case SCTP_RESTART:
380 {
381 /* Check that the new node is in the lockspace */
382 struct sctp_prim prim;
383 mm_segment_t fs;
384 int nodeid;
385 int prim_len, ret;
386 int addr_len;
387 struct nodeinfo *ni;
388
389 /* This seems to happen when we received a connection
390 * too early... or something... anyway, it happens but
391 * we always seem to get a real message too, see
392 * receive_from_sock */
393
394 if ((int)sn->sn_assoc_change.sac_assoc_id <= 0) {
395 log_print("COMM_UP for invalid assoc ID %d",
396 (int)sn->sn_assoc_change.sac_assoc_id);
397 init_failed();
398 return;
399 }
400 memset(&prim, 0, sizeof(struct sctp_prim));
401 prim_len = sizeof(struct sctp_prim);
402 prim.ssp_assoc_id = sn->sn_assoc_change.sac_assoc_id;
403
404 fs = get_fs();
405 set_fs(get_ds());
406 ret = sctp_con.sock->ops->getsockopt(sctp_con.sock,
407 IPPROTO_SCTP,
408 SCTP_PRIMARY_ADDR,
409 (char*)&prim,
410 &prim_len);
411 set_fs(fs);
412 if (ret < 0) {
413 struct nodeinfo *ni;
414
415 log_print("getsockopt/sctp_primary_addr on "
416 "new assoc %d failed : %d",
417 (int)sn->sn_assoc_change.sac_assoc_id,
418 ret);
419
420 /* Retry INIT later */
421 ni = assoc2nodeinfo(sn->sn_assoc_change.sac_assoc_id);
422 if (ni)
423 clear_bit(NI_INIT_PENDING, &ni->flags);
424 return;
425 }
426 make_sockaddr(&prim.ssp_addr, 0, &addr_len);
427 if (dlm_addr_to_nodeid(&prim.ssp_addr, &nodeid)) {
428 log_print("reject connect from unknown addr");
429 send_shutdown(prim.ssp_assoc_id);
430 return;
431 }
432
433 ni = nodeid2nodeinfo(nodeid, GFP_KERNEL);
434 if (!ni)
435 return;
436
437 /* Save the assoc ID */
438 ni->assoc_id = sn->sn_assoc_change.sac_assoc_id;
439
440 log_print("got new/restarted association %d nodeid %d",
441 (int)sn->sn_assoc_change.sac_assoc_id, nodeid);
442
443 /* Send any pending writes */
444 clear_bit(NI_INIT_PENDING, &ni->flags);
445 if (!test_and_set_bit(NI_WRITE_PENDING, &ni->flags)) {
446 spin_lock_bh(&write_nodes_lock);
447 list_add_tail(&ni->write_list, &write_nodes);
448 spin_unlock_bh(&write_nodes_lock);
449 }
450 wake_up_process(send_task);
451 }
452 break;
453
454 case SCTP_COMM_LOST:
455 case SCTP_SHUTDOWN_COMP:
456 {
457 struct nodeinfo *ni;
458
459 ni = assoc2nodeinfo(sn->sn_assoc_change.sac_assoc_id);
460 if (ni) {
461 spin_lock(&ni->lock);
462 ni->assoc_id = 0;
463 spin_unlock(&ni->lock);
464 }
465 }
466 break;
467
468 /* We don't know which INIT failed, so clear the PENDING flags
469 * on them all. if assoc_id is zero then it will then try
470 * again */
471
472 case SCTP_CANT_STR_ASSOC:
473 {
474 log_print("Can't start SCTP association - retrying");
475 init_failed();
476 }
477 break;
478
479 default:
480 log_print("unexpected SCTP assoc change id=%d state=%d",
481 (int)sn->sn_assoc_change.sac_assoc_id,
482 sn->sn_assoc_change.sac_state);
483 }
484 }
485}
486
487/* Data received from remote end */
488static int receive_from_sock(void)
489{
490 int ret = 0;
491 struct msghdr msg;
492 struct kvec iov[2];
493 unsigned len;
494 int r;
495 struct sctp_sndrcvinfo *sinfo;
496 struct cmsghdr *cmsg;
497 struct nodeinfo *ni;
498
499 /* These two are marginally too big for stack allocation, but this
500 * function is (currently) only called by dlm_recvd so static should be
501 * OK.
502 */
503 static struct sockaddr_storage msgname;
504 static char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
505
506 if (sctp_con.sock == NULL)
507 goto out;
508
509 if (sctp_con.rx_page == NULL) {
510 /*
511 * This doesn't need to be atomic, but I think it should
512 * improve performance if it is.
513 */
514 sctp_con.rx_page = alloc_page(GFP_ATOMIC);
515 if (sctp_con.rx_page == NULL)
516 goto out_resched;
517 cbuf_init(&sctp_con.cb, PAGE_CACHE_SIZE);
518 }
519
520 memset(&incmsg, 0, sizeof(incmsg));
521 memset(&msgname, 0, sizeof(msgname));
522
523 msg.msg_name = &msgname;
524 msg.msg_namelen = sizeof(msgname);
525 msg.msg_flags = 0;
526 msg.msg_control = incmsg;
527 msg.msg_controllen = sizeof(incmsg);
528 msg.msg_iovlen = 1;
529
530 /* I don't see why this circular buffer stuff is necessary for SCTP
531 * which is a packet-based protocol, but the whole thing breaks under
532 * load without it! The overhead is minimal (and is in the TCP lowcomms
533 * anyway, of course) so I'll leave it in until I can figure out what's
534 * really happening.
535 */
536
537 /*
538 * iov[0] is the bit of the circular buffer between the current end
539 * point (cb.base + cb.len) and the end of the buffer.
540 */
541 iov[0].iov_len = sctp_con.cb.base - cbuf_data(&sctp_con.cb);
542 iov[0].iov_base = page_address(sctp_con.rx_page) +
543 cbuf_data(&sctp_con.cb);
544 iov[1].iov_len = 0;
545
546 /*
547 * iov[1] is the bit of the circular buffer between the start of the
548 * buffer and the start of the currently used section (cb.base)
549 */
550 if (cbuf_data(&sctp_con.cb) >= sctp_con.cb.base) {
551 iov[0].iov_len = PAGE_CACHE_SIZE - cbuf_data(&sctp_con.cb);
552 iov[1].iov_len = sctp_con.cb.base;
553 iov[1].iov_base = page_address(sctp_con.rx_page);
554 msg.msg_iovlen = 2;
555 }
556 len = iov[0].iov_len + iov[1].iov_len;
557
558 r = ret = kernel_recvmsg(sctp_con.sock, &msg, iov, msg.msg_iovlen, len,
559 MSG_NOSIGNAL | MSG_DONTWAIT);
560 if (ret <= 0)
561 goto out_close;
562
563 msg.msg_control = incmsg;
564 msg.msg_controllen = sizeof(incmsg);
565 cmsg = CMSG_FIRSTHDR(&msg);
566 sinfo = CMSG_DATA(cmsg);
567
568 if (msg.msg_flags & MSG_NOTIFICATION) {
569 process_sctp_notification(&msg, page_address(sctp_con.rx_page));
570 return 0;
571 }
572
573 /* Is this a new association ? */
574 ni = nodeid2nodeinfo(le32_to_cpu(sinfo->sinfo_ppid), GFP_KERNEL);
575 if (ni) {
576 ni->assoc_id = sinfo->sinfo_assoc_id;
577 if (test_and_clear_bit(NI_INIT_PENDING, &ni->flags)) {
578
579 if (!test_and_set_bit(NI_WRITE_PENDING, &ni->flags)) {
580 spin_lock_bh(&write_nodes_lock);
581 list_add_tail(&ni->write_list, &write_nodes);
582 spin_unlock_bh(&write_nodes_lock);
583 }
584 wake_up_process(send_task);
585 }
586 }
587
588 /* INIT sends a message with length of 1 - ignore it */
589 if (r == 1)
590 return 0;
591
592 cbuf_add(&sctp_con.cb, ret);
593 ret = dlm_process_incoming_buffer(cpu_to_le32(sinfo->sinfo_ppid),
594 page_address(sctp_con.rx_page),
595 sctp_con.cb.base, sctp_con.cb.len,
596 PAGE_CACHE_SIZE);
597 if (ret < 0)
598 goto out_close;
599 cbuf_eat(&sctp_con.cb, ret);
600
601out:
602 ret = 0;
603 goto out_ret;
604
605out_resched:
606 lowcomms_data_ready(sctp_con.sock->sk, 0);
607 ret = 0;
608 cond_resched();
609 goto out_ret;
610
611out_close:
612 if (ret != -EAGAIN)
613 log_print("error reading from sctp socket: %d", ret);
614out_ret:
615 return ret;
616}
617
618/* Bind to an IP address. SCTP allows multiple address so it can do multi-homing */
619static int add_bind_addr(struct sockaddr_storage *addr, int addr_len, int num)
620{
621 mm_segment_t fs;
622 int result = 0;
623
624 fs = get_fs();
625 set_fs(get_ds());
626 if (num == 1)
627 result = sctp_con.sock->ops->bind(sctp_con.sock,
628 (struct sockaddr *) addr,
629 addr_len);
630 else
631 result = sctp_con.sock->ops->setsockopt(sctp_con.sock, SOL_SCTP,
632 SCTP_SOCKOPT_BINDX_ADD,
633 (char *)addr, addr_len);
634 set_fs(fs);
635
636 if (result < 0)
637 log_print("Can't bind to port %d addr number %d",
638 dlm_config.tcp_port, num);
639
640 return result;
641}
642
643static void init_local(void)
644{
645 struct sockaddr_storage sas, *addr;
646 int i;
647
648 dlm_local_nodeid = dlm_our_nodeid();
649
650 for (i = 0; i < DLM_MAX_ADDR_COUNT - 1; i++) {
651 if (dlm_our_addr(&sas, i))
652 break;
653
654 addr = kmalloc(sizeof(*addr), GFP_KERNEL);
655 if (!addr)
656 break;
657 memcpy(addr, &sas, sizeof(*addr));
658 dlm_local_addr[dlm_local_count++] = addr;
659 }
660}
661
662/* Initialise SCTP socket and bind to all interfaces */
663static int init_sock(void)
664{
665 mm_segment_t fs;
666 struct socket *sock = NULL;
667 struct sockaddr_storage localaddr;
668 struct sctp_event_subscribe subscribe;
669 int result = -EINVAL, num = 1, i, addr_len;
670
671 if (!dlm_local_count) {
672 init_local();
673 if (!dlm_local_count) {
674 log_print("no local IP address has been set");
675 goto out;
676 }
677 }
678
679 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_SEQPACKET,
680 IPPROTO_SCTP, &sock);
681 if (result < 0) {
682 log_print("Can't create comms socket, check SCTP is loaded");
683 goto out;
684 }
685
686 /* Listen for events */
687 memset(&subscribe, 0, sizeof(subscribe));
688 subscribe.sctp_data_io_event = 1;
689 subscribe.sctp_association_event = 1;
690 subscribe.sctp_send_failure_event = 1;
691 subscribe.sctp_shutdown_event = 1;
692 subscribe.sctp_partial_delivery_event = 1;
693
694 fs = get_fs();
695 set_fs(get_ds());
696 result = sock->ops->setsockopt(sock, SOL_SCTP, SCTP_EVENTS,
697 (char *)&subscribe, sizeof(subscribe));
698 set_fs(fs);
699
700 if (result < 0) {
701 log_print("Failed to set SCTP_EVENTS on socket: result=%d",
702 result);
703 goto create_delsock;
704 }
705
706 /* Init con struct */
707 sock->sk->sk_user_data = &sctp_con;
708 sctp_con.sock = sock;
709 sctp_con.sock->sk->sk_data_ready = lowcomms_data_ready;
710
711 /* Bind to all interfaces. */
712 for (i = 0; i < dlm_local_count; i++) {
713 memcpy(&localaddr, dlm_local_addr[i], sizeof(localaddr));
714 make_sockaddr(&localaddr, dlm_config.tcp_port, &addr_len);
715
716 result = add_bind_addr(&localaddr, addr_len, num);
717 if (result)
718 goto create_delsock;
719 ++num;
720 }
721
722 result = sock->ops->listen(sock, 5);
723 if (result < 0) {
724 log_print("Can't set socket listening");
725 goto create_delsock;
726 }
727
728 return 0;
729
730create_delsock:
731 sock_release(sock);
732 sctp_con.sock = NULL;
733out:
734 return result;
735}
736
737
738static struct writequeue_entry *new_writequeue_entry(gfp_t allocation)
739{
740 struct writequeue_entry *entry;
741
742 entry = kmalloc(sizeof(struct writequeue_entry), allocation);
743 if (!entry)
744 return NULL;
745
746 entry->page = alloc_page(allocation);
747 if (!entry->page) {
748 kfree(entry);
749 return NULL;
750 }
751
752 entry->offset = 0;
753 entry->len = 0;
754 entry->end = 0;
755 entry->users = 0;
756
757 return entry;
758}
759
760void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc)
761{
762 struct writequeue_entry *e;
763 int offset = 0;
764 int users = 0;
765 struct nodeinfo *ni;
766
767 ni = nodeid2nodeinfo(nodeid, allocation);
768 if (!ni)
769 return NULL;
770
771 spin_lock(&ni->writequeue_lock);
772 e = list_entry(ni->writequeue.prev, struct writequeue_entry, list);
773 if ((&e->list == &ni->writequeue) ||
774 (PAGE_CACHE_SIZE - e->end < len)) {
775 e = NULL;
776 } else {
777 offset = e->end;
778 e->end += len;
779 users = e->users++;
780 }
781 spin_unlock(&ni->writequeue_lock);
782
783 if (e) {
784 got_one:
785 if (users == 0)
786 kmap(e->page);
787 *ppc = page_address(e->page) + offset;
788 return e;
789 }
790
791 e = new_writequeue_entry(allocation);
792 if (e) {
793 spin_lock(&ni->writequeue_lock);
794 offset = e->end;
795 e->end += len;
796 e->ni = ni;
797 users = e->users++;
798 list_add_tail(&e->list, &ni->writequeue);
799 spin_unlock(&ni->writequeue_lock);
800 goto got_one;
801 }
802 return NULL;
803}
804
805void dlm_lowcomms_commit_buffer(void *arg)
806{
807 struct writequeue_entry *e = (struct writequeue_entry *) arg;
808 int users;
809 struct nodeinfo *ni = e->ni;
810
811 spin_lock(&ni->writequeue_lock);
812 users = --e->users;
813 if (users)
814 goto out;
815 e->len = e->end - e->offset;
816 kunmap(e->page);
817 spin_unlock(&ni->writequeue_lock);
818
819 if (!test_and_set_bit(NI_WRITE_PENDING, &ni->flags)) {
820 spin_lock_bh(&write_nodes_lock);
821 list_add_tail(&ni->write_list, &write_nodes);
822 spin_unlock_bh(&write_nodes_lock);
823 wake_up_process(send_task);
824 }
825 return;
826
827out:
828 spin_unlock(&ni->writequeue_lock);
829 return;
830}
831
832static void free_entry(struct writequeue_entry *e)
833{
834 __free_page(e->page);
835 kfree(e);
836}
837
838/* Initiate an SCTP association. In theory we could just use sendmsg() on
839 the first IP address and it should work, but this allows us to set up the
840 association before sending any valuable data that we can't afford to lose.
841 It also keeps the send path clean as it can now always use the association ID */
842static void initiate_association(int nodeid)
843{
844 struct sockaddr_storage rem_addr;
845 static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
846 struct msghdr outmessage;
847 struct cmsghdr *cmsg;
848 struct sctp_sndrcvinfo *sinfo;
849 int ret;
850 int addrlen;
851 char buf[1];
852 struct kvec iov[1];
853 struct nodeinfo *ni;
854
855 log_print("Initiating association with node %d", nodeid);
856
857 ni = nodeid2nodeinfo(nodeid, GFP_KERNEL);
858 if (!ni)
859 return;
860
861 if (nodeid_to_addr(nodeid, (struct sockaddr *)&rem_addr)) {
862 log_print("no address for nodeid %d", nodeid);
863 return;
864 }
865
866 make_sockaddr(&rem_addr, dlm_config.tcp_port, &addrlen);
867
868 outmessage.msg_name = &rem_addr;
869 outmessage.msg_namelen = addrlen;
870 outmessage.msg_control = outcmsg;
871 outmessage.msg_controllen = sizeof(outcmsg);
872 outmessage.msg_flags = MSG_EOR;
873
874 iov[0].iov_base = buf;
875 iov[0].iov_len = 1;
876
877 /* Real INIT messages seem to cause trouble. Just send a 1 byte message
878 we can afford to lose */
879 cmsg = CMSG_FIRSTHDR(&outmessage);
880 cmsg->cmsg_level = IPPROTO_SCTP;
881 cmsg->cmsg_type = SCTP_SNDRCV;
882 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
883 sinfo = CMSG_DATA(cmsg);
884 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo));
885 sinfo->sinfo_ppid = cpu_to_le32(dlm_local_nodeid);
886
887 outmessage.msg_controllen = cmsg->cmsg_len;
888 ret = kernel_sendmsg(sctp_con.sock, &outmessage, iov, 1, 1);
889 if (ret < 0) {
890 log_print("send INIT to node failed: %d", ret);
891 /* Try again later */
892 clear_bit(NI_INIT_PENDING, &ni->flags);
893 }
894}
895
896/* Send a message */
897static void send_to_sock(struct nodeinfo *ni)
898{
899 int ret = 0;
900 struct writequeue_entry *e;
901 int len, offset;
902 struct msghdr outmsg;
903 static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
904 struct cmsghdr *cmsg;
905 struct sctp_sndrcvinfo *sinfo;
906 struct kvec iov;
907
908 /* See if we need to init an association before we start
909 sending precious messages */
910 spin_lock(&ni->lock);
911 if (!ni->assoc_id && !test_and_set_bit(NI_INIT_PENDING, &ni->flags)) {
912 spin_unlock(&ni->lock);
913 initiate_association(ni->nodeid);
914 return;
915 }
916 spin_unlock(&ni->lock);
917
918 outmsg.msg_name = NULL; /* We use assoc_id */
919 outmsg.msg_namelen = 0;
920 outmsg.msg_control = outcmsg;
921 outmsg.msg_controllen = sizeof(outcmsg);
922 outmsg.msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL | MSG_EOR;
923
924 cmsg = CMSG_FIRSTHDR(&outmsg);
925 cmsg->cmsg_level = IPPROTO_SCTP;
926 cmsg->cmsg_type = SCTP_SNDRCV;
927 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
928 sinfo = CMSG_DATA(cmsg);
929 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo));
930 sinfo->sinfo_ppid = cpu_to_le32(dlm_local_nodeid);
931 sinfo->sinfo_assoc_id = ni->assoc_id;
932 outmsg.msg_controllen = cmsg->cmsg_len;
933
934 spin_lock(&ni->writequeue_lock);
935 for (;;) {
936 if (list_empty(&ni->writequeue))
937 break;
938 e = list_entry(ni->writequeue.next, struct writequeue_entry,
939 list);
940 len = e->len;
941 offset = e->offset;
942 BUG_ON(len == 0 && e->users == 0);
943 spin_unlock(&ni->writequeue_lock);
944 kmap(e->page);
945
946 ret = 0;
947 if (len) {
948 iov.iov_base = page_address(e->page)+offset;
949 iov.iov_len = len;
950
951 ret = kernel_sendmsg(sctp_con.sock, &outmsg, &iov, 1,
952 len);
953 if (ret == -EAGAIN) {
954 sctp_con.eagain_flag = 1;
955 goto out;
956 } else if (ret < 0)
957 goto send_error;
958 } else {
959 /* Don't starve people filling buffers */
960 cond_resched();
961 }
962
963 spin_lock(&ni->writequeue_lock);
964 e->offset += ret;
965 e->len -= ret;
966
967 if (e->len == 0 && e->users == 0) {
968 list_del(&e->list);
969 kunmap(e->page);
970 free_entry(e);
971 continue;
972 }
973 }
974 spin_unlock(&ni->writequeue_lock);
975out:
976 return;
977
978send_error:
979 log_print("Error sending to node %d %d", ni->nodeid, ret);
980 spin_lock(&ni->lock);
981 if (!test_and_set_bit(NI_INIT_PENDING, &ni->flags)) {
982 ni->assoc_id = 0;
983 spin_unlock(&ni->lock);
984 initiate_association(ni->nodeid);
985 } else
986 spin_unlock(&ni->lock);
987
988 return;
989}
990
991/* Try to send any messages that are pending */
992static void process_output_queue(void)
993{
994 struct list_head *list;
995 struct list_head *temp;
996
997 spin_lock_bh(&write_nodes_lock);
998 list_for_each_safe(list, temp, &write_nodes) {
999 struct nodeinfo *ni =
1000 list_entry(list, struct nodeinfo, write_list);
1001 clear_bit(NI_WRITE_PENDING, &ni->flags);
1002 list_del(&ni->write_list);
1003
1004 spin_unlock_bh(&write_nodes_lock);
1005
1006 send_to_sock(ni);
1007 spin_lock_bh(&write_nodes_lock);
1008 }
1009 spin_unlock_bh(&write_nodes_lock);
1010}
1011
1012/* Called after we've had -EAGAIN and been woken up */
1013static void refill_write_queue(void)
1014{
1015 int i;
1016
1017 for (i=1; i<=max_nodeid; i++) {
1018 struct nodeinfo *ni = nodeid2nodeinfo(i, 0);
1019
1020 if (ni) {
1021 if (!test_and_set_bit(NI_WRITE_PENDING, &ni->flags)) {
1022 spin_lock_bh(&write_nodes_lock);
1023 list_add_tail(&ni->write_list, &write_nodes);
1024 spin_unlock_bh(&write_nodes_lock);
1025 }
1026 }
1027 }
1028}
1029
1030static void clean_one_writequeue(struct nodeinfo *ni)
1031{
1032 struct list_head *list;
1033 struct list_head *temp;
1034
1035 spin_lock(&ni->writequeue_lock);
1036 list_for_each_safe(list, temp, &ni->writequeue) {
1037 struct writequeue_entry *e =
1038 list_entry(list, struct writequeue_entry, list);
1039 list_del(&e->list);
1040 free_entry(e);
1041 }
1042 spin_unlock(&ni->writequeue_lock);
1043}
1044
1045static void clean_writequeues(void)
1046{
1047 int i;
1048
1049 for (i=1; i<=max_nodeid; i++) {
1050 struct nodeinfo *ni = nodeid2nodeinfo(i, 0);
1051 if (ni)
1052 clean_one_writequeue(ni);
1053 }
1054}
1055
1056
1057static void dealloc_nodeinfo(void)
1058{
1059 int i;
1060
1061 for (i=1; i<=max_nodeid; i++) {
1062 struct nodeinfo *ni = nodeid2nodeinfo(i, 0);
1063 if (ni) {
1064 idr_remove(&nodeinfo_idr, i);
1065 kfree(ni);
1066 }
1067 }
1068}
1069
1070int dlm_lowcomms_close(int nodeid)
1071{
1072 struct nodeinfo *ni;
1073
1074 ni = nodeid2nodeinfo(nodeid, 0);
1075 if (!ni)
1076 return -1;
1077
1078 spin_lock(&ni->lock);
1079 if (ni->assoc_id) {
1080 ni->assoc_id = 0;
1081 /* Don't send shutdown here, sctp will just queue it
1082 till the node comes back up! */
1083 }
1084 spin_unlock(&ni->lock);
1085
1086 clean_one_writequeue(ni);
1087 clear_bit(NI_INIT_PENDING, &ni->flags);
1088 return 0;
1089}
1090
1091static int write_list_empty(void)
1092{
1093 int status;
1094
1095 spin_lock_bh(&write_nodes_lock);
1096 status = list_empty(&write_nodes);
1097 spin_unlock_bh(&write_nodes_lock);
1098
1099 return status;
1100}
1101
1102static int dlm_recvd(void *data)
1103{
1104 DECLARE_WAITQUEUE(wait, current);
1105
1106 while (!kthread_should_stop()) {
1107 int count = 0;
1108
1109 set_current_state(TASK_INTERRUPTIBLE);
1110 add_wait_queue(&lowcomms_recv_wait, &wait);
1111 if (!test_bit(CF_READ_PENDING, &sctp_con.flags))
1112 cond_resched();
1113 remove_wait_queue(&lowcomms_recv_wait, &wait);
1114 set_current_state(TASK_RUNNING);
1115
1116 if (test_and_clear_bit(CF_READ_PENDING, &sctp_con.flags)) {
1117 int ret;
1118
1119 do {
1120 ret = receive_from_sock();
1121
1122 /* Don't starve out everyone else */
1123 if (++count >= MAX_RX_MSG_COUNT) {
1124 cond_resched();
1125 count = 0;
1126 }
1127 } while (!kthread_should_stop() && ret >=0);
1128 }
1129 cond_resched();
1130 }
1131
1132 return 0;
1133}
1134
1135static int dlm_sendd(void *data)
1136{
1137 DECLARE_WAITQUEUE(wait, current);
1138
1139 add_wait_queue(sctp_con.sock->sk->sk_sleep, &wait);
1140
1141 while (!kthread_should_stop()) {
1142 set_current_state(TASK_INTERRUPTIBLE);
1143 if (write_list_empty())
1144 cond_resched();
1145 set_current_state(TASK_RUNNING);
1146
1147 if (sctp_con.eagain_flag) {
1148 sctp_con.eagain_flag = 0;
1149 refill_write_queue();
1150 }
1151 process_output_queue();
1152 }
1153
1154 remove_wait_queue(sctp_con.sock->sk->sk_sleep, &wait);
1155
1156 return 0;
1157}
1158
1159static void daemons_stop(void)
1160{
1161 kthread_stop(recv_task);
1162 kthread_stop(send_task);
1163}
1164
1165static int daemons_start(void)
1166{
1167 struct task_struct *p;
1168 int error;
1169
1170 p = kthread_run(dlm_recvd, NULL, "dlm_recvd");
1171 error = IS_ERR(p);
1172 if (error) {
1173 log_print("can't start dlm_recvd %d", error);
1174 return error;
1175 }
1176 recv_task = p;
1177
1178 p = kthread_run(dlm_sendd, NULL, "dlm_sendd");
1179 error = IS_ERR(p);
1180 if (error) {
1181 log_print("can't start dlm_sendd %d", error);
1182 kthread_stop(recv_task);
1183 return error;
1184 }
1185 send_task = p;
1186
1187 return 0;
1188}
1189
1190/*
1191 * This is quite likely to sleep...
1192 */
1193int dlm_lowcomms_start(void)
1194{
1195 int error;
1196
1197 error = init_sock();
1198 if (error)
1199 goto fail_sock;
1200 error = daemons_start();
1201 if (error)
1202 goto fail_sock;
1203 return 0;
1204
1205fail_sock:
1206 close_connection();
1207 return error;
1208}
1209
1210void dlm_lowcomms_stop(void)
1211{
1212 int i;
1213
1214 sctp_con.flags = 0x7;
1215 daemons_stop();
1216 clean_writequeues();
1217 close_connection();
1218 dealloc_nodeinfo();
1219 max_nodeid = 0;
1220
1221 dlm_local_count = 0;
1222 dlm_local_nodeid = 0;
1223
1224 for (i = 0; i < dlm_local_count; i++)
1225 kfree(dlm_local_addr[i]);
1226}
1227
generated by cgit v1.2.2 (git 2.25.0) at 2026-01-03 13:40:33 -0500