projects / deliverable / linux.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Merge ../linux-2.6/
[deliverable/linux.git] / fs / ocfs2 / dlm / dlmdomain.c
1 /* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * dlmdomain.c
5 *
6 * defines domain join / leave apis
7 *
8 * Copyright (C) 2004 Oracle. All rights reserved.
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public
12 * License as published by the Free Software Foundation; either
13 * version 2 of the License, or (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public
21 * License along with this program; if not, write to the
22 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 * Boston, MA 021110-1307, USA.
24 *
25 */
26
27 #include <linux/module.h>
28 #include <linux/types.h>
29 #include <linux/slab.h>
30 #include <linux/highmem.h>
31 #include <linux/utsname.h>
32 #include <linux/init.h>
33 #include <linux/spinlock.h>
34 #include <linux/delay.h>
35 #include <linux/err.h>
36
37 #include "cluster/heartbeat.h"
38 #include "cluster/nodemanager.h"
39 #include "cluster/tcp.h"
40
41 #include "dlmapi.h"
42 #include "dlmcommon.h"
43
44 #include "dlmdomain.h"
45
46 #include "dlmver.h"
47
48 #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_DOMAIN)
49 #include "cluster/masklog.h"
50
51 static void dlm_free_pagevec(void **vec, int pages)
52 {
53 while (pages--)
54 free_page((unsigned long)vec[pages]);
55 kfree(vec);
56 }
57
58 static void **dlm_alloc_pagevec(int pages)
59 {
60 void **vec = kmalloc(pages * sizeof(void *), GFP_KERNEL);
61 int i;
62
63 if (!vec)
64 return NULL;
65
66 for (i = 0; i < pages; i++)
67 if (!(vec[i] = (void *)__get_free_page(GFP_KERNEL)))
68 goto out_free;
69
70 mlog(0, "Allocated DLM hash pagevec; %d pages (%lu expected), %lu buckets per page\n",
71 pages, DLM_HASH_PAGES, (unsigned long)DLM_BUCKETS_PER_PAGE);
72 return vec;
73 out_free:
74 dlm_free_pagevec(vec, i);
75 return NULL;
76 }
77
78 /*
79 *
80 * spinlock lock ordering: if multiple locks are needed, obey this ordering:
81 * dlm_domain_lock
82 * struct dlm_ctxt->spinlock
83 * struct dlm_lock_resource->spinlock
84 * struct dlm_ctxt->master_lock
85 * struct dlm_ctxt->ast_lock
86 * dlm_master_list_entry->spinlock
87 * dlm_lock->spinlock
88 *
89 */
90
91 DEFINE_SPINLOCK(dlm_domain_lock);
92 LIST_HEAD(dlm_domains);
93 static DECLARE_WAIT_QUEUE_HEAD(dlm_domain_events);
94
95 #define DLM_DOMAIN_BACKOFF_MS 200
96
97 static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data);
98 static int dlm_assert_joined_handler(struct o2net_msg *msg, u32 len, void *data);
99 static int dlm_cancel_join_handler(struct o2net_msg *msg, u32 len, void *data);
100 static int dlm_exit_domain_handler(struct o2net_msg *msg, u32 len, void *data);
101
102 static void dlm_unregister_domain_handlers(struct dlm_ctxt *dlm);
103
104 void __dlm_unhash_lockres(struct dlm_lock_resource *lockres)
105 {
106 hlist_del_init(&lockres->hash_node);
107 dlm_lockres_put(lockres);
108 }
109
110 void __dlm_insert_lockres(struct dlm_ctxt *dlm,
111 struct dlm_lock_resource *res)
112 {
113 struct hlist_head *bucket;
114 struct qstr *q;
115
116 assert_spin_locked(&dlm->spinlock);
117
118 q = &res->lockname;
119 bucket = dlm_lockres_hash(dlm, q->hash);
120
121 /* get a reference for our hashtable */
122 dlm_lockres_get(res);
123
124 hlist_add_head(&res->hash_node, bucket);
125 }
126
127 struct dlm_lock_resource * __dlm_lookup_lockres(struct dlm_ctxt *dlm,
128 const char *name,
129 unsigned int len,
130 unsigned int hash)
131 {
132 struct hlist_head *bucket;
133 struct hlist_node *list;
134
135 mlog_entry("%.*s\n", len, name);
136
137 assert_spin_locked(&dlm->spinlock);
138
139 bucket = dlm_lockres_hash(dlm, hash);
140
141 hlist_for_each(list, bucket) {
142 struct dlm_lock_resource *res = hlist_entry(list,
143 struct dlm_lock_resource, hash_node);
144 if (res->lockname.name[0] != name[0])
145 continue;
146 if (unlikely(res->lockname.len != len))
147 continue;
148 if (memcmp(res->lockname.name + 1, name + 1, len - 1))
149 continue;
150 dlm_lockres_get(res);
151 return res;
152 }
153 return NULL;
154 }
155
156 struct dlm_lock_resource * dlm_lookup_lockres(struct dlm_ctxt *dlm,
157 const char *name,
158 unsigned int len)
159 {
160 struct dlm_lock_resource *res;
161 unsigned int hash = dlm_lockid_hash(name, len);
162
163 spin_lock(&dlm->spinlock);
164 res = __dlm_lookup_lockres(dlm, name, len, hash);
165 spin_unlock(&dlm->spinlock);
166 return res;
167 }
168
169 static struct dlm_ctxt * __dlm_lookup_domain_full(const char *domain, int len)
170 {
171 struct dlm_ctxt *tmp = NULL;
172 struct list_head *iter;
173
174 assert_spin_locked(&dlm_domain_lock);
175
176 /* tmp->name here is always NULL terminated,
177 * but domain may not be! */
178 list_for_each(iter, &dlm_domains) {
179 tmp = list_entry (iter, struct dlm_ctxt, list);
180 if (strlen(tmp->name) == len &&
181 memcmp(tmp->name, domain, len)==0)
182 break;
183 tmp = NULL;
184 }
185
186 return tmp;
187 }
188
189 /* For null terminated domain strings ONLY */
190 static struct dlm_ctxt * __dlm_lookup_domain(const char *domain)
191 {
192 assert_spin_locked(&dlm_domain_lock);
193
194 return __dlm_lookup_domain_full(domain, strlen(domain));
195 }
196
197
198 /* returns true on one of two conditions:
199 * 1) the domain does not exist
200 * 2) the domain exists and it's state is "joined" */
201 static int dlm_wait_on_domain_helper(const char *domain)
202 {
203 int ret = 0;
204 struct dlm_ctxt *tmp = NULL;
205
206 spin_lock(&dlm_domain_lock);
207
208 tmp = __dlm_lookup_domain(domain);
209 if (!tmp)
210 ret = 1;
211 else if (tmp->dlm_state == DLM_CTXT_JOINED)
212 ret = 1;
213
214 spin_unlock(&dlm_domain_lock);
215 return ret;
216 }
217
218 static void dlm_free_ctxt_mem(struct dlm_ctxt *dlm)
219 {
220 if (dlm->lockres_hash)
221 dlm_free_pagevec((void **)dlm->lockres_hash, DLM_HASH_PAGES);
222
223 if (dlm->name)
224 kfree(dlm->name);
225
226 kfree(dlm);
227 }
228
229 /* A little strange - this function will be called while holding
230 * dlm_domain_lock and is expected to be holding it on the way out. We
231 * will however drop and reacquire it multiple times */
232 static void dlm_ctxt_release(struct kref *kref)
233 {
234 struct dlm_ctxt *dlm;
235
236 dlm = container_of(kref, struct dlm_ctxt, dlm_refs);
237
238 BUG_ON(dlm->num_joins);
239 BUG_ON(dlm->dlm_state == DLM_CTXT_JOINED);
240
241 /* we may still be in the list if we hit an error during join. */
242 list_del_init(&dlm->list);
243
244 spin_unlock(&dlm_domain_lock);
245
246 mlog(0, "freeing memory from domain %s\n", dlm->name);
247
248 wake_up(&dlm_domain_events);
249
250 dlm_free_ctxt_mem(dlm);
251
252 spin_lock(&dlm_domain_lock);
253 }
254
255 void dlm_put(struct dlm_ctxt *dlm)
256 {
257 spin_lock(&dlm_domain_lock);
258 kref_put(&dlm->dlm_refs, dlm_ctxt_release);
259 spin_unlock(&dlm_domain_lock);
260 }
261
262 static void __dlm_get(struct dlm_ctxt *dlm)
263 {
264 kref_get(&dlm->dlm_refs);
265 }
266
267 /* given a questionable reference to a dlm object, gets a reference if
268 * it can find it in the list, otherwise returns NULL in which case
269 * you shouldn't trust your pointer. */
270 struct dlm_ctxt *dlm_grab(struct dlm_ctxt *dlm)
271 {
272 struct list_head *iter;
273 struct dlm_ctxt *target = NULL;
274
275 spin_lock(&dlm_domain_lock);
276
277 list_for_each(iter, &dlm_domains) {
278 target = list_entry (iter, struct dlm_ctxt, list);
279
280 if (target == dlm) {
281 __dlm_get(target);
282 break;
283 }
284
285 target = NULL;
286 }
287
288 spin_unlock(&dlm_domain_lock);
289
290 return target;
291 }
292
293 int dlm_domain_fully_joined(struct dlm_ctxt *dlm)
294 {
295 int ret;
296
297 spin_lock(&dlm_domain_lock);
298 ret = (dlm->dlm_state == DLM_CTXT_JOINED) ||
299 (dlm->dlm_state == DLM_CTXT_IN_SHUTDOWN);
300 spin_unlock(&dlm_domain_lock);
301
302 return ret;
303 }
304
305 static void dlm_destroy_dlm_worker(struct dlm_ctxt *dlm)
306 {
307 if (dlm->dlm_worker) {
308 flush_workqueue(dlm->dlm_worker);
309 destroy_workqueue(dlm->dlm_worker);
310 dlm->dlm_worker = NULL;
311 }
312 }
313
314 static void dlm_complete_dlm_shutdown(struct dlm_ctxt *dlm)
315 {
316 dlm_unregister_domain_handlers(dlm);
317 dlm_complete_thread(dlm);
318 dlm_complete_recovery_thread(dlm);
319 dlm_destroy_dlm_worker(dlm);
320
321 /* We've left the domain. Now we can take ourselves out of the
322 * list and allow the kref stuff to help us free the
323 * memory. */
324 spin_lock(&dlm_domain_lock);
325 list_del_init(&dlm->list);
326 spin_unlock(&dlm_domain_lock);
327
328 /* Wake up anyone waiting for us to remove this domain */
329 wake_up(&dlm_domain_events);
330 }
331
332 static void dlm_migrate_all_locks(struct dlm_ctxt *dlm)
333 {
334 int i;
335 struct dlm_lock_resource *res;
336
337 mlog(0, "Migrating locks from domain %s\n", dlm->name);
338 restart:
339 spin_lock(&dlm->spinlock);
340 for (i = 0; i < DLM_HASH_BUCKETS; i++) {
341 while (!hlist_empty(dlm_lockres_hash(dlm, i))) {
342 res = hlist_entry(dlm_lockres_hash(dlm, i)->first,
343 struct dlm_lock_resource, hash_node);
344 /* need reference when manually grabbing lockres */
345 dlm_lockres_get(res);
346 /* this should unhash the lockres
347 * and exit with dlm->spinlock */
348 mlog(0, "purging res=%p\n", res);
349 if (dlm_lockres_is_dirty(dlm, res)) {
350 /* HACK! this should absolutely go.
351 * need to figure out why some empty
352 * lockreses are still marked dirty */
353 mlog(ML_ERROR, "lockres %.*s dirty!\n",
354 res->lockname.len, res->lockname.name);
355
356 spin_unlock(&dlm->spinlock);
357 dlm_kick_thread(dlm, res);
358 wait_event(dlm->ast_wq, !dlm_lockres_is_dirty(dlm, res));
359 dlm_lockres_put(res);
360 goto restart;
361 }
362 dlm_purge_lockres(dlm, res);
363 dlm_lockres_put(res);
364 }
365 }
366 spin_unlock(&dlm->spinlock);
367
368 mlog(0, "DONE Migrating locks from domain %s\n", dlm->name);
369 }
370
371 static int dlm_no_joining_node(struct dlm_ctxt *dlm)
372 {
373 int ret;
374
375 spin_lock(&dlm->spinlock);
376 ret = dlm->joining_node == DLM_LOCK_RES_OWNER_UNKNOWN;
377 spin_unlock(&dlm->spinlock);
378
379 return ret;
380 }
381
382 static void dlm_mark_domain_leaving(struct dlm_ctxt *dlm)
383 {
384 /* Yikes, a double spinlock! I need domain_lock for the dlm
385 * state and the dlm spinlock for join state... Sorry! */
386 again:
387 spin_lock(&dlm_domain_lock);
388 spin_lock(&dlm->spinlock);
389
390 if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) {
391 mlog(0, "Node %d is joining, we wait on it.\n",
392 dlm->joining_node);
393 spin_unlock(&dlm->spinlock);
394 spin_unlock(&dlm_domain_lock);
395
396 wait_event(dlm->dlm_join_events, dlm_no_joining_node(dlm));
397 goto again;
398 }
399
400 dlm->dlm_state = DLM_CTXT_LEAVING;
401 spin_unlock(&dlm->spinlock);
402 spin_unlock(&dlm_domain_lock);
403 }
404
405 static void __dlm_print_nodes(struct dlm_ctxt *dlm)
406 {
407 int node = -1;
408
409 assert_spin_locked(&dlm->spinlock);
410
411 mlog(ML_NOTICE, "Nodes in my domain (\"%s\"):\n", dlm->name);
412
413 while ((node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES,
414 node + 1)) < O2NM_MAX_NODES) {
415 mlog(ML_NOTICE, " node %d\n", node);
416 }
417 }
418
419 static int dlm_exit_domain_handler(struct o2net_msg *msg, u32 len, void *data)
420 {
421 struct dlm_ctxt *dlm = data;
422 unsigned int node;
423 struct dlm_exit_domain *exit_msg = (struct dlm_exit_domain *) msg->buf;
424
425 mlog_entry("%p %u %p", msg, len, data);
426
427 if (!dlm_grab(dlm))
428 return 0;
429
430 node = exit_msg->node_idx;
431
432 mlog(0, "Node %u leaves domain %s\n", node, dlm->name);
433
434 spin_lock(&dlm->spinlock);
435 clear_bit(node, dlm->domain_map);
436 __dlm_print_nodes(dlm);
437
438 /* notify anything attached to the heartbeat events */
439 dlm_hb_event_notify_attached(dlm, node, 0);
440
441 spin_unlock(&dlm->spinlock);
442
443 dlm_put(dlm);
444
445 return 0;
446 }
447
448 static int dlm_send_one_domain_exit(struct dlm_ctxt *dlm,
449 unsigned int node)
450 {
451 int status;
452 struct dlm_exit_domain leave_msg;
453
454 mlog(0, "Asking node %u if we can leave the domain %s me = %u\n",
455 node, dlm->name, dlm->node_num);
456
457 memset(&leave_msg, 0, sizeof(leave_msg));
458 leave_msg.node_idx = dlm->node_num;
459
460 status = o2net_send_message(DLM_EXIT_DOMAIN_MSG, dlm->key,
461 &leave_msg, sizeof(leave_msg), node,
462 NULL);
463
464 mlog(0, "status return %d from o2net_send_message\n", status);
465
466 return status;
467 }
468
469
470 static void dlm_leave_domain(struct dlm_ctxt *dlm)
471 {
472 int node, clear_node, status;
473
474 /* At this point we've migrated away all our locks and won't
475 * accept mastership of new ones. The dlm is responsible for
476 * almost nothing now. We make sure not to confuse any joining
477 * nodes and then commence shutdown procedure. */
478
479 spin_lock(&dlm->spinlock);
480 /* Clear ourselves from the domain map */
481 clear_bit(dlm->node_num, dlm->domain_map);
482 while ((node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES,
483 0)) < O2NM_MAX_NODES) {
484 /* Drop the dlm spinlock. This is safe wrt the domain_map.
485 * -nodes cannot be added now as the
486 * query_join_handlers knows to respond with OK_NO_MAP
487 * -we catch the right network errors if a node is
488 * removed from the map while we're sending him the
489 * exit message. */
490 spin_unlock(&dlm->spinlock);
491
492 clear_node = 1;
493
494 status = dlm_send_one_domain_exit(dlm, node);
495 if (status < 0 &&
496 status != -ENOPROTOOPT &&
497 status != -ENOTCONN) {
498 mlog(ML_NOTICE, "Error %d sending domain exit message "
499 "to node %d\n", status, node);
500
501 /* Not sure what to do here but lets sleep for
502 * a bit in case this was a transient
503 * error... */
504 msleep(DLM_DOMAIN_BACKOFF_MS);
505 clear_node = 0;
506 }
507
508 spin_lock(&dlm->spinlock);
509 /* If we're not clearing the node bit then we intend
510 * to loop back around to try again. */
511 if (clear_node)
512 clear_bit(node, dlm->domain_map);
513 }
514 spin_unlock(&dlm->spinlock);
515 }
516
517 int dlm_joined(struct dlm_ctxt *dlm)
518 {
519 int ret = 0;
520
521 spin_lock(&dlm_domain_lock);
522
523 if (dlm->dlm_state == DLM_CTXT_JOINED)
524 ret = 1;
525
526 spin_unlock(&dlm_domain_lock);
527
528 return ret;
529 }
530
531 int dlm_shutting_down(struct dlm_ctxt *dlm)
532 {
533 int ret = 0;
534
535 spin_lock(&dlm_domain_lock);
536
537 if (dlm->dlm_state == DLM_CTXT_IN_SHUTDOWN)
538 ret = 1;
539
540 spin_unlock(&dlm_domain_lock);
541
542 return ret;
543 }
544
545 void dlm_unregister_domain(struct dlm_ctxt *dlm)
546 {
547 int leave = 0;
548
549 spin_lock(&dlm_domain_lock);
550 BUG_ON(dlm->dlm_state != DLM_CTXT_JOINED);
551 BUG_ON(!dlm->num_joins);
552
553 dlm->num_joins--;
554 if (!dlm->num_joins) {
555 /* We mark it "in shutdown" now so new register
556 * requests wait until we've completely left the
557 * domain. Don't use DLM_CTXT_LEAVING yet as we still
558 * want new domain joins to communicate with us at
559 * least until we've completed migration of our
560 * resources. */
561 dlm->dlm_state = DLM_CTXT_IN_SHUTDOWN;
562 leave = 1;
563 }
564 spin_unlock(&dlm_domain_lock);
565
566 if (leave) {
567 mlog(0, "shutting down domain %s\n", dlm->name);
568
569 /* We changed dlm state, notify the thread */
570 dlm_kick_thread(dlm, NULL);
571
572 dlm_migrate_all_locks(dlm);
573 dlm_mark_domain_leaving(dlm);
574 dlm_leave_domain(dlm);
575 dlm_complete_dlm_shutdown(dlm);
576 }
577 dlm_put(dlm);
578 }
579 EXPORT_SYMBOL_GPL(dlm_unregister_domain);
580
581 static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data)
582 {
583 struct dlm_query_join_request *query;
584 enum dlm_query_join_response response;
585 struct dlm_ctxt *dlm = NULL;
586
587 query = (struct dlm_query_join_request *) msg->buf;
588
589 mlog(0, "node %u wants to join domain %s\n", query->node_idx,
590 query->domain);
591
592 /*
593 * If heartbeat doesn't consider the node live, tell it
594 * to back off and try again. This gives heartbeat a chance
595 * to catch up.
596 */
597 if (!o2hb_check_node_heartbeating(query->node_idx)) {
598 mlog(0, "node %u is not in our live map yet\n",
599 query->node_idx);
600
601 response = JOIN_DISALLOW;
602 goto respond;
603 }
604
605 response = JOIN_OK_NO_MAP;
606
607 spin_lock(&dlm_domain_lock);
608 dlm = __dlm_lookup_domain_full(query->domain, query->name_len);
609 /* Once the dlm ctxt is marked as leaving then we don't want
610 * to be put in someone's domain map.
611 * Also, explicitly disallow joining at certain troublesome
612 * times (ie. during recovery). */
613 if (dlm && dlm->dlm_state != DLM_CTXT_LEAVING) {
614 int bit = query->node_idx;
615 spin_lock(&dlm->spinlock);
616
617 if (dlm->dlm_state == DLM_CTXT_NEW &&
618 dlm->joining_node == DLM_LOCK_RES_OWNER_UNKNOWN) {
619 /*If this is a brand new context and we
620 * haven't started our join process yet, then
621 * the other node won the race. */
622 response = JOIN_OK_NO_MAP;
623 } else if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) {
624 /* Disallow parallel joins. */
625 response = JOIN_DISALLOW;
626 } else if (dlm->reco.state & DLM_RECO_STATE_ACTIVE) {
627 mlog(ML_NOTICE, "node %u trying to join, but recovery "
628 "is ongoing.\n", bit);
629 response = JOIN_DISALLOW;
630 } else if (test_bit(bit, dlm->recovery_map)) {
631 mlog(ML_NOTICE, "node %u trying to join, but it "
632 "still needs recovery.\n", bit);
633 response = JOIN_DISALLOW;
634 } else if (test_bit(bit, dlm->domain_map)) {
635 mlog(ML_NOTICE, "node %u trying to join, but it "
636 "is still in the domain! needs recovery?\n",
637 bit);
638 response = JOIN_DISALLOW;
639 } else {
640 /* Alright we're fully a part of this domain
641 * so we keep some state as to who's joining
642 * and indicate to him that needs to be fixed
643 * up. */
644 response = JOIN_OK;
645 __dlm_set_joining_node(dlm, query->node_idx);
646 }
647
648 spin_unlock(&dlm->spinlock);
649 }
650 spin_unlock(&dlm_domain_lock);
651
652 respond:
653 mlog(0, "We respond with %u\n", response);
654
655 return response;
656 }
657
658 static int dlm_assert_joined_handler(struct o2net_msg *msg, u32 len, void *data)
659 {
660 struct dlm_assert_joined *assert;
661 struct dlm_ctxt *dlm = NULL;
662
663 assert = (struct dlm_assert_joined *) msg->buf;
664
665 mlog(0, "node %u asserts join on domain %s\n", assert->node_idx,
666 assert->domain);
667
668 spin_lock(&dlm_domain_lock);
669 dlm = __dlm_lookup_domain_full(assert->domain, assert->name_len);
670 /* XXX should we consider no dlm ctxt an error? */
671 if (dlm) {
672 spin_lock(&dlm->spinlock);
673
674 /* Alright, this node has officially joined our
675 * domain. Set him in the map and clean up our
676 * leftover join state. */
677 BUG_ON(dlm->joining_node != assert->node_idx);
678 set_bit(assert->node_idx, dlm->domain_map);
679 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
680
681 __dlm_print_nodes(dlm);
682
683 /* notify anything attached to the heartbeat events */
684 dlm_hb_event_notify_attached(dlm, assert->node_idx, 1);
685
686 spin_unlock(&dlm->spinlock);
687 }
688 spin_unlock(&dlm_domain_lock);
689
690 return 0;
691 }
692
693 static int dlm_cancel_join_handler(struct o2net_msg *msg, u32 len, void *data)
694 {
695 struct dlm_cancel_join *cancel;
696 struct dlm_ctxt *dlm = NULL;
697
698 cancel = (struct dlm_cancel_join *) msg->buf;
699
700 mlog(0, "node %u cancels join on domain %s\n", cancel->node_idx,
701 cancel->domain);
702
703 spin_lock(&dlm_domain_lock);
704 dlm = __dlm_lookup_domain_full(cancel->domain, cancel->name_len);
705
706 if (dlm) {
707 spin_lock(&dlm->spinlock);
708
709 /* Yikes, this guy wants to cancel his join. No
710 * problem, we simply cleanup our join state. */
711 BUG_ON(dlm->joining_node != cancel->node_idx);
712 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
713
714 spin_unlock(&dlm->spinlock);
715 }
716 spin_unlock(&dlm_domain_lock);
717
718 return 0;
719 }
720
721 static int dlm_send_one_join_cancel(struct dlm_ctxt *dlm,
722 unsigned int node)
723 {
724 int status;
725 struct dlm_cancel_join cancel_msg;
726
727 memset(&cancel_msg, 0, sizeof(cancel_msg));
728 cancel_msg.node_idx = dlm->node_num;
729 cancel_msg.name_len = strlen(dlm->name);
730 memcpy(cancel_msg.domain, dlm->name, cancel_msg.name_len);
731
732 status = o2net_send_message(DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY,
733 &cancel_msg, sizeof(cancel_msg), node,
734 NULL);
735 if (status < 0) {
736 mlog_errno(status);
737 goto bail;
738 }
739
740 bail:
741 return status;
742 }
743
744 /* map_size should be in bytes. */
745 static int dlm_send_join_cancels(struct dlm_ctxt *dlm,
746 unsigned long *node_map,
747 unsigned int map_size)
748 {
749 int status, tmpstat;
750 unsigned int node;
751
752 if (map_size != (BITS_TO_LONGS(O2NM_MAX_NODES) *
753 sizeof(unsigned long))) {
754 mlog(ML_ERROR,
755 "map_size %u != BITS_TO_LONGS(O2NM_MAX_NODES) %u\n",
756 map_size, BITS_TO_LONGS(O2NM_MAX_NODES));
757 return -EINVAL;
758 }
759
760 status = 0;
761 node = -1;
762 while ((node = find_next_bit(node_map, O2NM_MAX_NODES,
763 node + 1)) < O2NM_MAX_NODES) {
764 if (node == dlm->node_num)
765 continue;
766
767 tmpstat = dlm_send_one_join_cancel(dlm, node);
768 if (tmpstat) {
769 mlog(ML_ERROR, "Error return %d cancelling join on "
770 "node %d\n", tmpstat, node);
771 if (!status)
772 status = tmpstat;
773 }
774 }
775
776 if (status)
777 mlog_errno(status);
778 return status;
779 }
780
781 static int dlm_request_join(struct dlm_ctxt *dlm,
782 int node,
783 enum dlm_query_join_response *response)
784 {
785 int status, retval;
786 struct dlm_query_join_request join_msg;
787
788 mlog(0, "querying node %d\n", node);
789
790 memset(&join_msg, 0, sizeof(join_msg));
791 join_msg.node_idx = dlm->node_num;
792 join_msg.name_len = strlen(dlm->name);
793 memcpy(join_msg.domain, dlm->name, join_msg.name_len);
794
795 status = o2net_send_message(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY, &join_msg,
796 sizeof(join_msg), node, &retval);
797 if (status < 0 && status != -ENOPROTOOPT) {
798 mlog_errno(status);
799 goto bail;
800 }
801
802 /* -ENOPROTOOPT from the net code means the other side isn't
803 listening for our message type -- that's fine, it means
804 his dlm isn't up, so we can consider him a 'yes' but not
805 joined into the domain. */
806 if (status == -ENOPROTOOPT) {
807 status = 0;
808 *response = JOIN_OK_NO_MAP;
809 } else if (retval == JOIN_DISALLOW ||
810 retval == JOIN_OK ||
811 retval == JOIN_OK_NO_MAP) {
812 *response = retval;
813 } else {
814 status = -EINVAL;
815 mlog(ML_ERROR, "invalid response %d from node %u\n", retval,
816 node);
817 }
818
819 mlog(0, "status %d, node %d response is %d\n", status, node,
820 *response);
821
822 bail:
823 return status;
824 }
825
826 static int dlm_send_one_join_assert(struct dlm_ctxt *dlm,
827 unsigned int node)
828 {
829 int status;
830 struct dlm_assert_joined assert_msg;
831
832 mlog(0, "Sending join assert to node %u\n", node);
833
834 memset(&assert_msg, 0, sizeof(assert_msg));
835 assert_msg.node_idx = dlm->node_num;
836 assert_msg.name_len = strlen(dlm->name);
837 memcpy(assert_msg.domain, dlm->name, assert_msg.name_len);
838
839 status = o2net_send_message(DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY,
840 &assert_msg, sizeof(assert_msg), node,
841 NULL);
842 if (status < 0)
843 mlog_errno(status);
844
845 return status;
846 }
847
848 static void dlm_send_join_asserts(struct dlm_ctxt *dlm,
849 unsigned long *node_map)
850 {
851 int status, node, live;
852
853 status = 0;
854 node = -1;
855 while ((node = find_next_bit(node_map, O2NM_MAX_NODES,
856 node + 1)) < O2NM_MAX_NODES) {
857 if (node == dlm->node_num)
858 continue;
859
860 do {
861 /* It is very important that this message be
862 * received so we spin until either the node
863 * has died or it gets the message. */
864 status = dlm_send_one_join_assert(dlm, node);
865
866 spin_lock(&dlm->spinlock);
867 live = test_bit(node, dlm->live_nodes_map);
868 spin_unlock(&dlm->spinlock);
869
870 if (status) {
871 mlog(ML_ERROR, "Error return %d asserting "
872 "join on node %d\n", status, node);
873
874 /* give us some time between errors... */
875 if (live)
876 msleep(DLM_DOMAIN_BACKOFF_MS);
877 }
878 } while (status && live);
879 }
880 }
881
882 struct domain_join_ctxt {
883 unsigned long live_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
884 unsigned long yes_resp_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
885 };
886
887 static int dlm_should_restart_join(struct dlm_ctxt *dlm,
888 struct domain_join_ctxt *ctxt,
889 enum dlm_query_join_response response)
890 {
891 int ret;
892
893 if (response == JOIN_DISALLOW) {
894 mlog(0, "Latest response of disallow -- should restart\n");
895 return 1;
896 }
897
898 spin_lock(&dlm->spinlock);
899 /* For now, we restart the process if the node maps have
900 * changed at all */
901 ret = memcmp(ctxt->live_map, dlm->live_nodes_map,
902 sizeof(dlm->live_nodes_map));
903 spin_unlock(&dlm->spinlock);
904
905 if (ret)
906 mlog(0, "Node maps changed -- should restart\n");
907
908 return ret;
909 }
910
911 static int dlm_try_to_join_domain(struct dlm_ctxt *dlm)
912 {
913 int status = 0, tmpstat, node;
914 struct domain_join_ctxt *ctxt;
915 enum dlm_query_join_response response;
916
917 mlog_entry("%p", dlm);
918
919 ctxt = kcalloc(1, sizeof(*ctxt), GFP_KERNEL);
920 if (!ctxt) {
921 status = -ENOMEM;
922 mlog_errno(status);
923 goto bail;
924 }
925
926 /* group sem locking should work for us here -- we're already
927 * registered for heartbeat events so filling this should be
928 * atomic wrt getting those handlers called. */
929 o2hb_fill_node_map(dlm->live_nodes_map, sizeof(dlm->live_nodes_map));
930
931 spin_lock(&dlm->spinlock);
932 memcpy(ctxt->live_map, dlm->live_nodes_map, sizeof(ctxt->live_map));
933
934 __dlm_set_joining_node(dlm, dlm->node_num);
935
936 spin_unlock(&dlm->spinlock);
937
938 node = -1;
939 while ((node = find_next_bit(ctxt->live_map, O2NM_MAX_NODES,
940 node + 1)) < O2NM_MAX_NODES) {
941 if (node == dlm->node_num)
942 continue;
943
944 status = dlm_request_join(dlm, node, &response);
945 if (status < 0) {
946 mlog_errno(status);
947 goto bail;
948 }
949
950 /* Ok, either we got a response or the node doesn't have a
951 * dlm up. */
952 if (response == JOIN_OK)
953 set_bit(node, ctxt->yes_resp_map);
954
955 if (dlm_should_restart_join(dlm, ctxt, response)) {
956 status = -EAGAIN;
957 goto bail;
958 }
959 }
960
961 mlog(0, "Yay, done querying nodes!\n");
962
963 /* Yay, everyone agree's we can join the domain. My domain is
964 * comprised of all nodes who were put in the
965 * yes_resp_map. Copy that into our domain map and send a join
966 * assert message to clean up everyone elses state. */
967 spin_lock(&dlm->spinlock);
968 memcpy(dlm->domain_map, ctxt->yes_resp_map,
969 sizeof(ctxt->yes_resp_map));
970 set_bit(dlm->node_num, dlm->domain_map);
971 spin_unlock(&dlm->spinlock);
972
973 dlm_send_join_asserts(dlm, ctxt->yes_resp_map);
974
975 /* Joined state *must* be set before the joining node
976 * information, otherwise the query_join handler may read no
977 * current joiner but a state of NEW and tell joining nodes
978 * we're not in the domain. */
979 spin_lock(&dlm_domain_lock);
980 dlm->dlm_state = DLM_CTXT_JOINED;
981 dlm->num_joins++;
982 spin_unlock(&dlm_domain_lock);
983
984 bail:
985 spin_lock(&dlm->spinlock);
986 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
987 if (!status)
988 __dlm_print_nodes(dlm);
989 spin_unlock(&dlm->spinlock);
990
991 if (ctxt) {
992 /* Do we need to send a cancel message to any nodes? */
993 if (status < 0) {
994 tmpstat = dlm_send_join_cancels(dlm,
995 ctxt->yes_resp_map,
996 sizeof(ctxt->yes_resp_map));
997 if (tmpstat < 0)
998 mlog_errno(tmpstat);
999 }
1000 kfree(ctxt);
1001 }
1002
1003 mlog(0, "returning %d\n", status);
1004 return status;
1005 }
1006
1007 static void dlm_unregister_domain_handlers(struct dlm_ctxt *dlm)
1008 {
1009 o2hb_unregister_callback(&dlm->dlm_hb_up);
1010 o2hb_unregister_callback(&dlm->dlm_hb_down);
1011 o2net_unregister_handler_list(&dlm->dlm_domain_handlers);
1012 }
1013
1014 static int dlm_register_domain_handlers(struct dlm_ctxt *dlm)
1015 {
1016 int status;
1017
1018 mlog(0, "registering handlers.\n");
1019
1020 o2hb_setup_callback(&dlm->dlm_hb_down, O2HB_NODE_DOWN_CB,
1021 dlm_hb_node_down_cb, dlm, DLM_HB_NODE_DOWN_PRI);
1022 status = o2hb_register_callback(&dlm->dlm_hb_down);
1023 if (status)
1024 goto bail;
1025
1026 o2hb_setup_callback(&dlm->dlm_hb_up, O2HB_NODE_UP_CB,
1027 dlm_hb_node_up_cb, dlm, DLM_HB_NODE_UP_PRI);
1028 status = o2hb_register_callback(&dlm->dlm_hb_up);
1029 if (status)
1030 goto bail;
1031
1032 status = o2net_register_handler(DLM_MASTER_REQUEST_MSG, dlm->key,
1033 sizeof(struct dlm_master_request),
1034 dlm_master_request_handler,
1035 dlm, &dlm->dlm_domain_handlers);
1036 if (status)
1037 goto bail;
1038
1039 status = o2net_register_handler(DLM_ASSERT_MASTER_MSG, dlm->key,
1040 sizeof(struct dlm_assert_master),
1041 dlm_assert_master_handler,
1042 dlm, &dlm->dlm_domain_handlers);
1043 if (status)
1044 goto bail;
1045
1046 status = o2net_register_handler(DLM_CREATE_LOCK_MSG, dlm->key,
1047 sizeof(struct dlm_create_lock),
1048 dlm_create_lock_handler,
1049 dlm, &dlm->dlm_domain_handlers);
1050 if (status)
1051 goto bail;
1052
1053 status = o2net_register_handler(DLM_CONVERT_LOCK_MSG, dlm->key,
1054 DLM_CONVERT_LOCK_MAX_LEN,
1055 dlm_convert_lock_handler,
1056 dlm, &dlm->dlm_domain_handlers);
1057 if (status)
1058 goto bail;
1059
1060 status = o2net_register_handler(DLM_UNLOCK_LOCK_MSG, dlm->key,
1061 DLM_UNLOCK_LOCK_MAX_LEN,
1062 dlm_unlock_lock_handler,
1063 dlm, &dlm->dlm_domain_handlers);
1064 if (status)
1065 goto bail;
1066
1067 status = o2net_register_handler(DLM_PROXY_AST_MSG, dlm->key,
1068 DLM_PROXY_AST_MAX_LEN,
1069 dlm_proxy_ast_handler,
1070 dlm, &dlm->dlm_domain_handlers);
1071 if (status)
1072 goto bail;
1073
1074 status = o2net_register_handler(DLM_EXIT_DOMAIN_MSG, dlm->key,
1075 sizeof(struct dlm_exit_domain),
1076 dlm_exit_domain_handler,
1077 dlm, &dlm->dlm_domain_handlers);
1078 if (status)
1079 goto bail;
1080
1081 status = o2net_register_handler(DLM_MIGRATE_REQUEST_MSG, dlm->key,
1082 sizeof(struct dlm_migrate_request),
1083 dlm_migrate_request_handler,
1084 dlm, &dlm->dlm_domain_handlers);
1085 if (status)
1086 goto bail;
1087
1088 status = o2net_register_handler(DLM_MIG_LOCKRES_MSG, dlm->key,
1089 DLM_MIG_LOCKRES_MAX_LEN,
1090 dlm_mig_lockres_handler,
1091 dlm, &dlm->dlm_domain_handlers);
1092 if (status)
1093 goto bail;
1094
1095 status = o2net_register_handler(DLM_MASTER_REQUERY_MSG, dlm->key,
1096 sizeof(struct dlm_master_requery),
1097 dlm_master_requery_handler,
1098 dlm, &dlm->dlm_domain_handlers);
1099 if (status)
1100 goto bail;
1101
1102 status = o2net_register_handler(DLM_LOCK_REQUEST_MSG, dlm->key,
1103 sizeof(struct dlm_lock_request),
1104 dlm_request_all_locks_handler,
1105 dlm, &dlm->dlm_domain_handlers);
1106 if (status)
1107 goto bail;
1108
1109 status = o2net_register_handler(DLM_RECO_DATA_DONE_MSG, dlm->key,
1110 sizeof(struct dlm_reco_data_done),
1111 dlm_reco_data_done_handler,
1112 dlm, &dlm->dlm_domain_handlers);
1113 if (status)
1114 goto bail;
1115
1116 status = o2net_register_handler(DLM_BEGIN_RECO_MSG, dlm->key,
1117 sizeof(struct dlm_begin_reco),
1118 dlm_begin_reco_handler,
1119 dlm, &dlm->dlm_domain_handlers);
1120 if (status)
1121 goto bail;
1122
1123 status = o2net_register_handler(DLM_FINALIZE_RECO_MSG, dlm->key,
1124 sizeof(struct dlm_finalize_reco),
1125 dlm_finalize_reco_handler,
1126 dlm, &dlm->dlm_domain_handlers);
1127 if (status)
1128 goto bail;
1129
1130 bail:
1131 if (status)
1132 dlm_unregister_domain_handlers(dlm);
1133
1134 return status;
1135 }
1136
1137 static int dlm_join_domain(struct dlm_ctxt *dlm)
1138 {
1139 int status;
1140
1141 BUG_ON(!dlm);
1142
1143 mlog(0, "Join domain %s\n", dlm->name);
1144
1145 status = dlm_register_domain_handlers(dlm);
1146 if (status) {
1147 mlog_errno(status);
1148 goto bail;
1149 }
1150
1151 status = dlm_launch_thread(dlm);
1152 if (status < 0) {
1153 mlog_errno(status);
1154 goto bail;
1155 }
1156
1157 status = dlm_launch_recovery_thread(dlm);
1158 if (status < 0) {
1159 mlog_errno(status);
1160 goto bail;
1161 }
1162
1163 dlm->dlm_worker = create_singlethread_workqueue("dlm_wq");
1164 if (!dlm->dlm_worker) {
1165 status = -ENOMEM;
1166 mlog_errno(status);
1167 goto bail;
1168 }
1169
1170 do {
1171 unsigned int backoff;
1172 status = dlm_try_to_join_domain(dlm);
1173
1174 /* If we're racing another node to the join, then we
1175 * need to back off temporarily and let them
1176 * complete. */
1177 if (status == -EAGAIN) {
1178 if (signal_pending(current)) {
1179 status = -ERESTARTSYS;
1180 goto bail;
1181 }
1182
1183 /*
1184 * <chip> After you!
1185 * <dale> No, after you!
1186 * <chip> I insist!
1187 * <dale> But you first!
1188 * ...
1189 */
1190 backoff = (unsigned int)(jiffies & 0x3);
1191 backoff *= DLM_DOMAIN_BACKOFF_MS;
1192 mlog(0, "backoff %d\n", backoff);
1193 msleep(backoff);
1194 }
1195 } while (status == -EAGAIN);
1196
1197 if (status < 0) {
1198 mlog_errno(status);
1199 goto bail;
1200 }
1201
1202 status = 0;
1203 bail:
1204 wake_up(&dlm_domain_events);
1205
1206 if (status) {
1207 dlm_unregister_domain_handlers(dlm);
1208 dlm_complete_thread(dlm);
1209 dlm_complete_recovery_thread(dlm);
1210 dlm_destroy_dlm_worker(dlm);
1211 }
1212
1213 return status;
1214 }
1215
1216 static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain,
1217 u32 key)
1218 {
1219 int i;
1220 struct dlm_ctxt *dlm = NULL;
1221
1222 dlm = kcalloc(1, sizeof(*dlm), GFP_KERNEL);
1223 if (!dlm) {
1224 mlog_errno(-ENOMEM);
1225 goto leave;
1226 }
1227
1228 dlm->name = kmalloc(strlen(domain) + 1, GFP_KERNEL);
1229 if (dlm->name == NULL) {
1230 mlog_errno(-ENOMEM);
1231 kfree(dlm);
1232 dlm = NULL;
1233 goto leave;
1234 }
1235
1236 dlm->lockres_hash = (struct hlist_head **)dlm_alloc_pagevec(DLM_HASH_PAGES);
1237 if (!dlm->lockres_hash) {
1238 mlog_errno(-ENOMEM);
1239 kfree(dlm->name);
1240 kfree(dlm);
1241 dlm = NULL;
1242 goto leave;
1243 }
1244
1245 for (i = 0; i < DLM_HASH_BUCKETS; i++)
1246 INIT_HLIST_HEAD(dlm_lockres_hash(dlm, i));
1247
1248 strcpy(dlm->name, domain);
1249 dlm->key = key;
1250 dlm->node_num = o2nm_this_node();
1251
1252 spin_lock_init(&dlm->spinlock);
1253 spin_lock_init(&dlm->master_lock);
1254 spin_lock_init(&dlm->ast_lock);
1255 INIT_LIST_HEAD(&dlm->list);
1256 INIT_LIST_HEAD(&dlm->dirty_list);
1257 INIT_LIST_HEAD(&dlm->reco.resources);
1258 INIT_LIST_HEAD(&dlm->reco.received);
1259 INIT_LIST_HEAD(&dlm->reco.node_data);
1260 INIT_LIST_HEAD(&dlm->purge_list);
1261 INIT_LIST_HEAD(&dlm->dlm_domain_handlers);
1262 dlm->reco.state = 0;
1263
1264 INIT_LIST_HEAD(&dlm->pending_asts);
1265 INIT_LIST_HEAD(&dlm->pending_basts);
1266
1267 mlog(0, "dlm->recovery_map=%p, &(dlm->recovery_map[0])=%p\n",
1268 dlm->recovery_map, &(dlm->recovery_map[0]));
1269
1270 memset(dlm->recovery_map, 0, sizeof(dlm->recovery_map));
1271 memset(dlm->live_nodes_map, 0, sizeof(dlm->live_nodes_map));
1272 memset(dlm->domain_map, 0, sizeof(dlm->domain_map));
1273
1274 dlm->dlm_thread_task = NULL;
1275 dlm->dlm_reco_thread_task = NULL;
1276 dlm->dlm_worker = NULL;
1277 init_waitqueue_head(&dlm->dlm_thread_wq);
1278 init_waitqueue_head(&dlm->dlm_reco_thread_wq);
1279 init_waitqueue_head(&dlm->reco.event);
1280 init_waitqueue_head(&dlm->ast_wq);
1281 init_waitqueue_head(&dlm->migration_wq);
1282 INIT_LIST_HEAD(&dlm->master_list);
1283 INIT_LIST_HEAD(&dlm->mle_hb_events);
1284
1285 dlm->joining_node = DLM_LOCK_RES_OWNER_UNKNOWN;
1286 init_waitqueue_head(&dlm->dlm_join_events);
1287
1288 dlm->reco.new_master = O2NM_INVALID_NODE_NUM;
1289 dlm->reco.dead_node = O2NM_INVALID_NODE_NUM;
1290 atomic_set(&dlm->local_resources, 0);
1291 atomic_set(&dlm->remote_resources, 0);
1292 atomic_set(&dlm->unknown_resources, 0);
1293
1294 spin_lock_init(&dlm->work_lock);
1295 INIT_LIST_HEAD(&dlm->work_list);
1296 INIT_WORK(&dlm->dispatched_work, dlm_dispatch_work, dlm);
1297
1298 kref_init(&dlm->dlm_refs);
1299 dlm->dlm_state = DLM_CTXT_NEW;
1300
1301 INIT_LIST_HEAD(&dlm->dlm_eviction_callbacks);
1302
1303 mlog(0, "context init: refcount %u\n",
1304 atomic_read(&dlm->dlm_refs.refcount));
1305
1306 leave:
1307 return dlm;
1308 }
1309
1310 /*
1311 * dlm_register_domain: one-time setup per "domain"
1312 */
1313 struct dlm_ctxt * dlm_register_domain(const char *domain,
1314 u32 key)
1315 {
1316 int ret;
1317 struct dlm_ctxt *dlm = NULL;
1318 struct dlm_ctxt *new_ctxt = NULL;
1319
1320 if (strlen(domain) > O2NM_MAX_NAME_LEN) {
1321 ret = -ENAMETOOLONG;
1322 mlog(ML_ERROR, "domain name length too long\n");
1323 goto leave;
1324 }
1325
1326 if (!o2hb_check_local_node_heartbeating()) {
1327 mlog(ML_ERROR, "the local node has not been configured, or is "
1328 "not heartbeating\n");
1329 ret = -EPROTO;
1330 goto leave;
1331 }
1332
1333 mlog(0, "register called for domain \"%s\"\n", domain);
1334
1335 retry:
1336 dlm = NULL;
1337 if (signal_pending(current)) {
1338 ret = -ERESTARTSYS;
1339 mlog_errno(ret);
1340 goto leave;
1341 }
1342
1343 spin_lock(&dlm_domain_lock);
1344
1345 dlm = __dlm_lookup_domain(domain);
1346 if (dlm) {
1347 if (dlm->dlm_state != DLM_CTXT_JOINED) {
1348 spin_unlock(&dlm_domain_lock);
1349
1350 mlog(0, "This ctxt is not joined yet!\n");
1351 wait_event_interruptible(dlm_domain_events,
1352 dlm_wait_on_domain_helper(
1353 domain));
1354 goto retry;
1355 }
1356
1357 __dlm_get(dlm);
1358 dlm->num_joins++;
1359
1360 spin_unlock(&dlm_domain_lock);
1361
1362 ret = 0;
1363 goto leave;
1364 }
1365
1366 /* doesn't exist */
1367 if (!new_ctxt) {
1368 spin_unlock(&dlm_domain_lock);
1369
1370 new_ctxt = dlm_alloc_ctxt(domain, key);
1371 if (new_ctxt)
1372 goto retry;
1373
1374 ret = -ENOMEM;
1375 mlog_errno(ret);
1376 goto leave;
1377 }
1378
1379 /* a little variable switch-a-roo here... */
1380 dlm = new_ctxt;
1381 new_ctxt = NULL;
1382
1383 /* add the new domain */
1384 list_add_tail(&dlm->list, &dlm_domains);
1385 spin_unlock(&dlm_domain_lock);
1386
1387 ret = dlm_join_domain(dlm);
1388 if (ret) {
1389 mlog_errno(ret);
1390 dlm_put(dlm);
1391 goto leave;
1392 }
1393
1394 ret = 0;
1395 leave:
1396 if (new_ctxt)
1397 dlm_free_ctxt_mem(new_ctxt);
1398
1399 if (ret < 0)
1400 dlm = ERR_PTR(ret);
1401
1402 return dlm;
1403 }
1404 EXPORT_SYMBOL_GPL(dlm_register_domain);
1405
1406 static LIST_HEAD(dlm_join_handlers);
1407
1408 static void dlm_unregister_net_handlers(void)
1409 {
1410 o2net_unregister_handler_list(&dlm_join_handlers);
1411 }
1412
1413 static int dlm_register_net_handlers(void)
1414 {
1415 int status = 0;
1416
1417 status = o2net_register_handler(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY,
1418 sizeof(struct dlm_query_join_request),
1419 dlm_query_join_handler,
1420 NULL, &dlm_join_handlers);
1421 if (status)
1422 goto bail;
1423
1424 status = o2net_register_handler(DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY,
1425 sizeof(struct dlm_assert_joined),
1426 dlm_assert_joined_handler,
1427 NULL, &dlm_join_handlers);
1428 if (status)
1429 goto bail;
1430
1431 status = o2net_register_handler(DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY,
1432 sizeof(struct dlm_cancel_join),
1433 dlm_cancel_join_handler,
1434 NULL, &dlm_join_handlers);
1435
1436 bail:
1437 if (status < 0)
1438 dlm_unregister_net_handlers();
1439
1440 return status;
1441 }
1442
1443 /* Domain eviction callback handling.
1444 *
1445 * The file system requires notification of node death *before* the
1446 * dlm completes it's recovery work, otherwise it may be able to
1447 * acquire locks on resources requiring recovery. Since the dlm can
1448 * evict a node from it's domain *before* heartbeat fires, a similar
1449 * mechanism is required. */
1450
1451 /* Eviction is not expected to happen often, so a per-domain lock is
1452 * not necessary. Eviction callbacks are allowed to sleep for short
1453 * periods of time. */
1454 static DECLARE_RWSEM(dlm_callback_sem);
1455
1456 void dlm_fire_domain_eviction_callbacks(struct dlm_ctxt *dlm,
1457 int node_num)
1458 {
1459 struct list_head *iter;
1460 struct dlm_eviction_cb *cb;
1461
1462 down_read(&dlm_callback_sem);
1463 list_for_each(iter, &dlm->dlm_eviction_callbacks) {
1464 cb = list_entry(iter, struct dlm_eviction_cb, ec_item);
1465
1466 cb->ec_func(node_num, cb->ec_data);
1467 }
1468 up_read(&dlm_callback_sem);
1469 }
1470
1471 void dlm_setup_eviction_cb(struct dlm_eviction_cb *cb,
1472 dlm_eviction_func *f,
1473 void *data)
1474 {
1475 INIT_LIST_HEAD(&cb->ec_item);
1476 cb->ec_func = f;
1477 cb->ec_data = data;
1478 }
1479 EXPORT_SYMBOL_GPL(dlm_setup_eviction_cb);
1480
1481 void dlm_register_eviction_cb(struct dlm_ctxt *dlm,
1482 struct dlm_eviction_cb *cb)
1483 {
1484 down_write(&dlm_callback_sem);
1485 list_add_tail(&cb->ec_item, &dlm->dlm_eviction_callbacks);
1486 up_write(&dlm_callback_sem);
1487 }
1488 EXPORT_SYMBOL_GPL(dlm_register_eviction_cb);
1489
1490 void dlm_unregister_eviction_cb(struct dlm_eviction_cb *cb)
1491 {
1492 down_write(&dlm_callback_sem);
1493 list_del_init(&cb->ec_item);
1494 up_write(&dlm_callback_sem);
1495 }
1496 EXPORT_SYMBOL_GPL(dlm_unregister_eviction_cb);
1497
1498 static int __init dlm_init(void)
1499 {
1500 int status;
1501
1502 dlm_print_version();
1503
1504 status = dlm_init_mle_cache();
1505 if (status)
1506 return -1;
1507
1508 status = dlm_register_net_handlers();
1509 if (status) {
1510 dlm_destroy_mle_cache();
1511 return -1;
1512 }
1513
1514 return 0;
1515 }
1516
1517 static void __exit dlm_exit (void)
1518 {
1519 dlm_unregister_net_handlers();
1520 dlm_destroy_mle_cache();
1521 }
1522
1523 MODULE_AUTHOR("Oracle");
1524 MODULE_LICENSE("GPL");
1525
1526 module_init(dlm_init);
1527 module_exit(dlm_exit);
Linux kernel - Deliverables
This page took 0.085363 seconds and 6 git commands to generate.