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[PATCH] Fix numerous kcalloc() calls, convert to kzalloc()
[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, (unsigned long)DLM_HASH_PAGES,
72 (unsigned long)DLM_BUCKETS_PER_PAGE);
73 return vec;
74 out_free:
75 dlm_free_pagevec(vec, i);
76 return NULL;
77 }
78
79 /*
80 *
81 * spinlock lock ordering: if multiple locks are needed, obey this ordering:
82 * dlm_domain_lock
83 * struct dlm_ctxt->spinlock
84 * struct dlm_lock_resource->spinlock
85 * struct dlm_ctxt->master_lock
86 * struct dlm_ctxt->ast_lock
87 * dlm_master_list_entry->spinlock
88 * dlm_lock->spinlock
89 *
90 */
91
92 DEFINE_SPINLOCK(dlm_domain_lock);
93 LIST_HEAD(dlm_domains);
94 static DECLARE_WAIT_QUEUE_HEAD(dlm_domain_events);
95
96 #define DLM_DOMAIN_BACKOFF_MS 200
97
98 static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data);
99 static int dlm_assert_joined_handler(struct o2net_msg *msg, u32 len, void *data);
100 static int dlm_cancel_join_handler(struct o2net_msg *msg, u32 len, void *data);
101 static int dlm_exit_domain_handler(struct o2net_msg *msg, u32 len, void *data);
102
103 static void dlm_unregister_domain_handlers(struct dlm_ctxt *dlm);
104
105 void __dlm_unhash_lockres(struct dlm_lock_resource *lockres)
106 {
107 hlist_del_init(&lockres->hash_node);
108 dlm_lockres_put(lockres);
109 }
110
111 void __dlm_insert_lockres(struct dlm_ctxt *dlm,
112 struct dlm_lock_resource *res)
113 {
114 struct hlist_head *bucket;
115 struct qstr *q;
116
117 assert_spin_locked(&dlm->spinlock);
118
119 q = &res->lockname;
120 bucket = dlm_lockres_hash(dlm, q->hash);
121
122 /* get a reference for our hashtable */
123 dlm_lockres_get(res);
124
125 hlist_add_head(&res->hash_node, bucket);
126 }
127
128 struct dlm_lock_resource * __dlm_lookup_lockres(struct dlm_ctxt *dlm,
129 const char *name,
130 unsigned int len,
131 unsigned int hash)
132 {
133 struct hlist_head *bucket;
134 struct hlist_node *list;
135
136 mlog_entry("%.*s\n", len, name);
137
138 assert_spin_locked(&dlm->spinlock);
139
140 bucket = dlm_lockres_hash(dlm, hash);
141
142 hlist_for_each(list, bucket) {
143 struct dlm_lock_resource *res = hlist_entry(list,
144 struct dlm_lock_resource, hash_node);
145 if (res->lockname.name[0] != name[0])
146 continue;
147 if (unlikely(res->lockname.len != len))
148 continue;
149 if (memcmp(res->lockname.name + 1, name + 1, len - 1))
150 continue;
151 dlm_lockres_get(res);
152 return res;
153 }
154 return NULL;
155 }
156
157 struct dlm_lock_resource * dlm_lookup_lockres(struct dlm_ctxt *dlm,
158 const char *name,
159 unsigned int len)
160 {
161 struct dlm_lock_resource *res;
162 unsigned int hash = dlm_lockid_hash(name, len);
163
164 spin_lock(&dlm->spinlock);
165 res = __dlm_lookup_lockres(dlm, name, len, hash);
166 spin_unlock(&dlm->spinlock);
167 return res;
168 }
169
170 static struct dlm_ctxt * __dlm_lookup_domain_full(const char *domain, int len)
171 {
172 struct dlm_ctxt *tmp = NULL;
173 struct list_head *iter;
174
175 assert_spin_locked(&dlm_domain_lock);
176
177 /* tmp->name here is always NULL terminated,
178 * but domain may not be! */
179 list_for_each(iter, &dlm_domains) {
180 tmp = list_entry (iter, struct dlm_ctxt, list);
181 if (strlen(tmp->name) == len &&
182 memcmp(tmp->name, domain, len)==0)
183 break;
184 tmp = NULL;
185 }
186
187 return tmp;
188 }
189
190 /* For null terminated domain strings ONLY */
191 static struct dlm_ctxt * __dlm_lookup_domain(const char *domain)
192 {
193 assert_spin_locked(&dlm_domain_lock);
194
195 return __dlm_lookup_domain_full(domain, strlen(domain));
196 }
197
198
199 /* returns true on one of two conditions:
200 * 1) the domain does not exist
201 * 2) the domain exists and it's state is "joined" */
202 static int dlm_wait_on_domain_helper(const char *domain)
203 {
204 int ret = 0;
205 struct dlm_ctxt *tmp = NULL;
206
207 spin_lock(&dlm_domain_lock);
208
209 tmp = __dlm_lookup_domain(domain);
210 if (!tmp)
211 ret = 1;
212 else if (tmp->dlm_state == DLM_CTXT_JOINED)
213 ret = 1;
214
215 spin_unlock(&dlm_domain_lock);
216 return ret;
217 }
218
219 static void dlm_free_ctxt_mem(struct dlm_ctxt *dlm)
220 {
221 if (dlm->lockres_hash)
222 dlm_free_pagevec((void **)dlm->lockres_hash, DLM_HASH_PAGES);
223
224 if (dlm->name)
225 kfree(dlm->name);
226
227 kfree(dlm);
228 }
229
230 /* A little strange - this function will be called while holding
231 * dlm_domain_lock and is expected to be holding it on the way out. We
232 * will however drop and reacquire it multiple times */
233 static void dlm_ctxt_release(struct kref *kref)
234 {
235 struct dlm_ctxt *dlm;
236
237 dlm = container_of(kref, struct dlm_ctxt, dlm_refs);
238
239 BUG_ON(dlm->num_joins);
240 BUG_ON(dlm->dlm_state == DLM_CTXT_JOINED);
241
242 /* we may still be in the list if we hit an error during join. */
243 list_del_init(&dlm->list);
244
245 spin_unlock(&dlm_domain_lock);
246
247 mlog(0, "freeing memory from domain %s\n", dlm->name);
248
249 wake_up(&dlm_domain_events);
250
251 dlm_free_ctxt_mem(dlm);
252
253 spin_lock(&dlm_domain_lock);
254 }
255
256 void dlm_put(struct dlm_ctxt *dlm)
257 {
258 spin_lock(&dlm_domain_lock);
259 kref_put(&dlm->dlm_refs, dlm_ctxt_release);
260 spin_unlock(&dlm_domain_lock);
261 }
262
263 static void __dlm_get(struct dlm_ctxt *dlm)
264 {
265 kref_get(&dlm->dlm_refs);
266 }
267
268 /* given a questionable reference to a dlm object, gets a reference if
269 * it can find it in the list, otherwise returns NULL in which case
270 * you shouldn't trust your pointer. */
271 struct dlm_ctxt *dlm_grab(struct dlm_ctxt *dlm)
272 {
273 struct list_head *iter;
274 struct dlm_ctxt *target = NULL;
275
276 spin_lock(&dlm_domain_lock);
277
278 list_for_each(iter, &dlm_domains) {
279 target = list_entry (iter, struct dlm_ctxt, list);
280
281 if (target == dlm) {
282 __dlm_get(target);
283 break;
284 }
285
286 target = NULL;
287 }
288
289 spin_unlock(&dlm_domain_lock);
290
291 return target;
292 }
293
294 int dlm_domain_fully_joined(struct dlm_ctxt *dlm)
295 {
296 int ret;
297
298 spin_lock(&dlm_domain_lock);
299 ret = (dlm->dlm_state == DLM_CTXT_JOINED) ||
300 (dlm->dlm_state == DLM_CTXT_IN_SHUTDOWN);
301 spin_unlock(&dlm_domain_lock);
302
303 return ret;
304 }
305
306 static void dlm_destroy_dlm_worker(struct dlm_ctxt *dlm)
307 {
308 if (dlm->dlm_worker) {
309 flush_workqueue(dlm->dlm_worker);
310 destroy_workqueue(dlm->dlm_worker);
311 dlm->dlm_worker = NULL;
312 }
313 }
314
315 static void dlm_complete_dlm_shutdown(struct dlm_ctxt *dlm)
316 {
317 dlm_unregister_domain_handlers(dlm);
318 dlm_complete_thread(dlm);
319 dlm_complete_recovery_thread(dlm);
320 dlm_destroy_dlm_worker(dlm);
321
322 /* We've left the domain. Now we can take ourselves out of the
323 * list and allow the kref stuff to help us free the
324 * memory. */
325 spin_lock(&dlm_domain_lock);
326 list_del_init(&dlm->list);
327 spin_unlock(&dlm_domain_lock);
328
329 /* Wake up anyone waiting for us to remove this domain */
330 wake_up(&dlm_domain_events);
331 }
332
333 static void dlm_migrate_all_locks(struct dlm_ctxt *dlm)
334 {
335 int i;
336 struct dlm_lock_resource *res;
337
338 mlog(0, "Migrating locks from domain %s\n", dlm->name);
339 restart:
340 spin_lock(&dlm->spinlock);
341 for (i = 0; i < DLM_HASH_BUCKETS; i++) {
342 while (!hlist_empty(dlm_lockres_hash(dlm, i))) {
343 res = hlist_entry(dlm_lockres_hash(dlm, i)->first,
344 struct dlm_lock_resource, hash_node);
345 /* need reference when manually grabbing lockres */
346 dlm_lockres_get(res);
347 /* this should unhash the lockres
348 * and exit with dlm->spinlock */
349 mlog(0, "purging res=%p\n", res);
350 if (dlm_lockres_is_dirty(dlm, res)) {
351 /* HACK! this should absolutely go.
352 * need to figure out why some empty
353 * lockreses are still marked dirty */
354 mlog(ML_ERROR, "lockres %.*s dirty!\n",
355 res->lockname.len, res->lockname.name);
356
357 spin_unlock(&dlm->spinlock);
358 dlm_kick_thread(dlm, res);
359 wait_event(dlm->ast_wq, !dlm_lockres_is_dirty(dlm, res));
360 dlm_lockres_put(res);
361 goto restart;
362 }
363 dlm_purge_lockres(dlm, res);
364 dlm_lockres_put(res);
365 }
366 }
367 spin_unlock(&dlm->spinlock);
368
369 mlog(0, "DONE Migrating locks from domain %s\n", dlm->name);
370 }
371
372 static int dlm_no_joining_node(struct dlm_ctxt *dlm)
373 {
374 int ret;
375
376 spin_lock(&dlm->spinlock);
377 ret = dlm->joining_node == DLM_LOCK_RES_OWNER_UNKNOWN;
378 spin_unlock(&dlm->spinlock);
379
380 return ret;
381 }
382
383 static void dlm_mark_domain_leaving(struct dlm_ctxt *dlm)
384 {
385 /* Yikes, a double spinlock! I need domain_lock for the dlm
386 * state and the dlm spinlock for join state... Sorry! */
387 again:
388 spin_lock(&dlm_domain_lock);
389 spin_lock(&dlm->spinlock);
390
391 if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) {
392 mlog(0, "Node %d is joining, we wait on it.\n",
393 dlm->joining_node);
394 spin_unlock(&dlm->spinlock);
395 spin_unlock(&dlm_domain_lock);
396
397 wait_event(dlm->dlm_join_events, dlm_no_joining_node(dlm));
398 goto again;
399 }
400
401 dlm->dlm_state = DLM_CTXT_LEAVING;
402 spin_unlock(&dlm->spinlock);
403 spin_unlock(&dlm_domain_lock);
404 }
405
406 static void __dlm_print_nodes(struct dlm_ctxt *dlm)
407 {
408 int node = -1;
409
410 assert_spin_locked(&dlm->spinlock);
411
412 printk(KERN_INFO "ocfs2_dlm: Nodes in domain (\"%s\"): ", dlm->name);
413
414 while ((node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES,
415 node + 1)) < O2NM_MAX_NODES) {
416 printk("%d ", node);
417 }
418 printk("\n");
419 }
420
421 static int dlm_exit_domain_handler(struct o2net_msg *msg, u32 len, void *data)
422 {
423 struct dlm_ctxt *dlm = data;
424 unsigned int node;
425 struct dlm_exit_domain *exit_msg = (struct dlm_exit_domain *) msg->buf;
426
427 mlog_entry("%p %u %p", msg, len, data);
428
429 if (!dlm_grab(dlm))
430 return 0;
431
432 node = exit_msg->node_idx;
433
434 printk(KERN_INFO "ocfs2_dlm: Node %u leaves domain %s\n", node, dlm->name);
435
436 spin_lock(&dlm->spinlock);
437 clear_bit(node, dlm->domain_map);
438 __dlm_print_nodes(dlm);
439
440 /* notify anything attached to the heartbeat events */
441 dlm_hb_event_notify_attached(dlm, node, 0);
442
443 spin_unlock(&dlm->spinlock);
444
445 dlm_put(dlm);
446
447 return 0;
448 }
449
450 static int dlm_send_one_domain_exit(struct dlm_ctxt *dlm,
451 unsigned int node)
452 {
453 int status;
454 struct dlm_exit_domain leave_msg;
455
456 mlog(0, "Asking node %u if we can leave the domain %s me = %u\n",
457 node, dlm->name, dlm->node_num);
458
459 memset(&leave_msg, 0, sizeof(leave_msg));
460 leave_msg.node_idx = dlm->node_num;
461
462 status = o2net_send_message(DLM_EXIT_DOMAIN_MSG, dlm->key,
463 &leave_msg, sizeof(leave_msg), node,
464 NULL);
465
466 mlog(0, "status return %d from o2net_send_message\n", status);
467
468 return status;
469 }
470
471
472 static void dlm_leave_domain(struct dlm_ctxt *dlm)
473 {
474 int node, clear_node, status;
475
476 /* At this point we've migrated away all our locks and won't
477 * accept mastership of new ones. The dlm is responsible for
478 * almost nothing now. We make sure not to confuse any joining
479 * nodes and then commence shutdown procedure. */
480
481 spin_lock(&dlm->spinlock);
482 /* Clear ourselves from the domain map */
483 clear_bit(dlm->node_num, dlm->domain_map);
484 while ((node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES,
485 0)) < O2NM_MAX_NODES) {
486 /* Drop the dlm spinlock. This is safe wrt the domain_map.
487 * -nodes cannot be added now as the
488 * query_join_handlers knows to respond with OK_NO_MAP
489 * -we catch the right network errors if a node is
490 * removed from the map while we're sending him the
491 * exit message. */
492 spin_unlock(&dlm->spinlock);
493
494 clear_node = 1;
495
496 status = dlm_send_one_domain_exit(dlm, node);
497 if (status < 0 &&
498 status != -ENOPROTOOPT &&
499 status != -ENOTCONN) {
500 mlog(ML_NOTICE, "Error %d sending domain exit message "
501 "to node %d\n", status, node);
502
503 /* Not sure what to do here but lets sleep for
504 * a bit in case this was a transient
505 * error... */
506 msleep(DLM_DOMAIN_BACKOFF_MS);
507 clear_node = 0;
508 }
509
510 spin_lock(&dlm->spinlock);
511 /* If we're not clearing the node bit then we intend
512 * to loop back around to try again. */
513 if (clear_node)
514 clear_bit(node, dlm->domain_map);
515 }
516 spin_unlock(&dlm->spinlock);
517 }
518
519 int dlm_joined(struct dlm_ctxt *dlm)
520 {
521 int ret = 0;
522
523 spin_lock(&dlm_domain_lock);
524
525 if (dlm->dlm_state == DLM_CTXT_JOINED)
526 ret = 1;
527
528 spin_unlock(&dlm_domain_lock);
529
530 return ret;
531 }
532
533 int dlm_shutting_down(struct dlm_ctxt *dlm)
534 {
535 int ret = 0;
536
537 spin_lock(&dlm_domain_lock);
538
539 if (dlm->dlm_state == DLM_CTXT_IN_SHUTDOWN)
540 ret = 1;
541
542 spin_unlock(&dlm_domain_lock);
543
544 return ret;
545 }
546
547 void dlm_unregister_domain(struct dlm_ctxt *dlm)
548 {
549 int leave = 0;
550
551 spin_lock(&dlm_domain_lock);
552 BUG_ON(dlm->dlm_state != DLM_CTXT_JOINED);
553 BUG_ON(!dlm->num_joins);
554
555 dlm->num_joins--;
556 if (!dlm->num_joins) {
557 /* We mark it "in shutdown" now so new register
558 * requests wait until we've completely left the
559 * domain. Don't use DLM_CTXT_LEAVING yet as we still
560 * want new domain joins to communicate with us at
561 * least until we've completed migration of our
562 * resources. */
563 dlm->dlm_state = DLM_CTXT_IN_SHUTDOWN;
564 leave = 1;
565 }
566 spin_unlock(&dlm_domain_lock);
567
568 if (leave) {
569 mlog(0, "shutting down domain %s\n", dlm->name);
570
571 /* We changed dlm state, notify the thread */
572 dlm_kick_thread(dlm, NULL);
573
574 dlm_migrate_all_locks(dlm);
575 dlm_mark_domain_leaving(dlm);
576 dlm_leave_domain(dlm);
577 dlm_complete_dlm_shutdown(dlm);
578 }
579 dlm_put(dlm);
580 }
581 EXPORT_SYMBOL_GPL(dlm_unregister_domain);
582
583 static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data)
584 {
585 struct dlm_query_join_request *query;
586 enum dlm_query_join_response response;
587 struct dlm_ctxt *dlm = NULL;
588
589 query = (struct dlm_query_join_request *) msg->buf;
590
591 mlog(0, "node %u wants to join domain %s\n", query->node_idx,
592 query->domain);
593
594 /*
595 * If heartbeat doesn't consider the node live, tell it
596 * to back off and try again. This gives heartbeat a chance
597 * to catch up.
598 */
599 if (!o2hb_check_node_heartbeating(query->node_idx)) {
600 mlog(0, "node %u is not in our live map yet\n",
601 query->node_idx);
602
603 response = JOIN_DISALLOW;
604 goto respond;
605 }
606
607 response = JOIN_OK_NO_MAP;
608
609 spin_lock(&dlm_domain_lock);
610 dlm = __dlm_lookup_domain_full(query->domain, query->name_len);
611 /* Once the dlm ctxt is marked as leaving then we don't want
612 * to be put in someone's domain map.
613 * Also, explicitly disallow joining at certain troublesome
614 * times (ie. during recovery). */
615 if (dlm && dlm->dlm_state != DLM_CTXT_LEAVING) {
616 int bit = query->node_idx;
617 spin_lock(&dlm->spinlock);
618
619 if (dlm->dlm_state == DLM_CTXT_NEW &&
620 dlm->joining_node == DLM_LOCK_RES_OWNER_UNKNOWN) {
621 /*If this is a brand new context and we
622 * haven't started our join process yet, then
623 * the other node won the race. */
624 response = JOIN_OK_NO_MAP;
625 } else if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) {
626 /* Disallow parallel joins. */
627 response = JOIN_DISALLOW;
628 } else if (dlm->reco.state & DLM_RECO_STATE_ACTIVE) {
629 mlog(ML_NOTICE, "node %u trying to join, but recovery "
630 "is ongoing.\n", bit);
631 response = JOIN_DISALLOW;
632 } else if (test_bit(bit, dlm->recovery_map)) {
633 mlog(ML_NOTICE, "node %u trying to join, but it "
634 "still needs recovery.\n", bit);
635 response = JOIN_DISALLOW;
636 } else if (test_bit(bit, dlm->domain_map)) {
637 mlog(ML_NOTICE, "node %u trying to join, but it "
638 "is still in the domain! needs recovery?\n",
639 bit);
640 response = JOIN_DISALLOW;
641 } else {
642 /* Alright we're fully a part of this domain
643 * so we keep some state as to who's joining
644 * and indicate to him that needs to be fixed
645 * up. */
646 response = JOIN_OK;
647 __dlm_set_joining_node(dlm, query->node_idx);
648 }
649
650 spin_unlock(&dlm->spinlock);
651 }
652 spin_unlock(&dlm_domain_lock);
653
654 respond:
655 mlog(0, "We respond with %u\n", response);
656
657 return response;
658 }
659
660 static int dlm_assert_joined_handler(struct o2net_msg *msg, u32 len, void *data)
661 {
662 struct dlm_assert_joined *assert;
663 struct dlm_ctxt *dlm = NULL;
664
665 assert = (struct dlm_assert_joined *) msg->buf;
666
667 mlog(0, "node %u asserts join on domain %s\n", assert->node_idx,
668 assert->domain);
669
670 spin_lock(&dlm_domain_lock);
671 dlm = __dlm_lookup_domain_full(assert->domain, assert->name_len);
672 /* XXX should we consider no dlm ctxt an error? */
673 if (dlm) {
674 spin_lock(&dlm->spinlock);
675
676 /* Alright, this node has officially joined our
677 * domain. Set him in the map and clean up our
678 * leftover join state. */
679 BUG_ON(dlm->joining_node != assert->node_idx);
680 set_bit(assert->node_idx, dlm->domain_map);
681 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
682
683 printk(KERN_INFO "ocfs2_dlm: Node %u joins domain %s\n",
684 assert->node_idx, dlm->name);
685 __dlm_print_nodes(dlm);
686
687 /* notify anything attached to the heartbeat events */
688 dlm_hb_event_notify_attached(dlm, assert->node_idx, 1);
689
690 spin_unlock(&dlm->spinlock);
691 }
692 spin_unlock(&dlm_domain_lock);
693
694 return 0;
695 }
696
697 static int dlm_cancel_join_handler(struct o2net_msg *msg, u32 len, void *data)
698 {
699 struct dlm_cancel_join *cancel;
700 struct dlm_ctxt *dlm = NULL;
701
702 cancel = (struct dlm_cancel_join *) msg->buf;
703
704 mlog(0, "node %u cancels join on domain %s\n", cancel->node_idx,
705 cancel->domain);
706
707 spin_lock(&dlm_domain_lock);
708 dlm = __dlm_lookup_domain_full(cancel->domain, cancel->name_len);
709
710 if (dlm) {
711 spin_lock(&dlm->spinlock);
712
713 /* Yikes, this guy wants to cancel his join. No
714 * problem, we simply cleanup our join state. */
715 BUG_ON(dlm->joining_node != cancel->node_idx);
716 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
717
718 spin_unlock(&dlm->spinlock);
719 }
720 spin_unlock(&dlm_domain_lock);
721
722 return 0;
723 }
724
725 static int dlm_send_one_join_cancel(struct dlm_ctxt *dlm,
726 unsigned int node)
727 {
728 int status;
729 struct dlm_cancel_join cancel_msg;
730
731 memset(&cancel_msg, 0, sizeof(cancel_msg));
732 cancel_msg.node_idx = dlm->node_num;
733 cancel_msg.name_len = strlen(dlm->name);
734 memcpy(cancel_msg.domain, dlm->name, cancel_msg.name_len);
735
736 status = o2net_send_message(DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY,
737 &cancel_msg, sizeof(cancel_msg), node,
738 NULL);
739 if (status < 0) {
740 mlog_errno(status);
741 goto bail;
742 }
743
744 bail:
745 return status;
746 }
747
748 /* map_size should be in bytes. */
749 static int dlm_send_join_cancels(struct dlm_ctxt *dlm,
750 unsigned long *node_map,
751 unsigned int map_size)
752 {
753 int status, tmpstat;
754 unsigned int node;
755
756 if (map_size != (BITS_TO_LONGS(O2NM_MAX_NODES) *
757 sizeof(unsigned long))) {
758 mlog(ML_ERROR,
759 "map_size %u != BITS_TO_LONGS(O2NM_MAX_NODES) %u\n",
760 map_size, BITS_TO_LONGS(O2NM_MAX_NODES));
761 return -EINVAL;
762 }
763
764 status = 0;
765 node = -1;
766 while ((node = find_next_bit(node_map, O2NM_MAX_NODES,
767 node + 1)) < O2NM_MAX_NODES) {
768 if (node == dlm->node_num)
769 continue;
770
771 tmpstat = dlm_send_one_join_cancel(dlm, node);
772 if (tmpstat) {
773 mlog(ML_ERROR, "Error return %d cancelling join on "
774 "node %d\n", tmpstat, node);
775 if (!status)
776 status = tmpstat;
777 }
778 }
779
780 if (status)
781 mlog_errno(status);
782 return status;
783 }
784
785 static int dlm_request_join(struct dlm_ctxt *dlm,
786 int node,
787 enum dlm_query_join_response *response)
788 {
789 int status, retval;
790 struct dlm_query_join_request join_msg;
791
792 mlog(0, "querying node %d\n", node);
793
794 memset(&join_msg, 0, sizeof(join_msg));
795 join_msg.node_idx = dlm->node_num;
796 join_msg.name_len = strlen(dlm->name);
797 memcpy(join_msg.domain, dlm->name, join_msg.name_len);
798
799 status = o2net_send_message(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY, &join_msg,
800 sizeof(join_msg), node, &retval);
801 if (status < 0 && status != -ENOPROTOOPT) {
802 mlog_errno(status);
803 goto bail;
804 }
805
806 /* -ENOPROTOOPT from the net code means the other side isn't
807 listening for our message type -- that's fine, it means
808 his dlm isn't up, so we can consider him a 'yes' but not
809 joined into the domain. */
810 if (status == -ENOPROTOOPT) {
811 status = 0;
812 *response = JOIN_OK_NO_MAP;
813 } else if (retval == JOIN_DISALLOW ||
814 retval == JOIN_OK ||
815 retval == JOIN_OK_NO_MAP) {
816 *response = retval;
817 } else {
818 status = -EINVAL;
819 mlog(ML_ERROR, "invalid response %d from node %u\n", retval,
820 node);
821 }
822
823 mlog(0, "status %d, node %d response is %d\n", status, node,
824 *response);
825
826 bail:
827 return status;
828 }
829
830 static int dlm_send_one_join_assert(struct dlm_ctxt *dlm,
831 unsigned int node)
832 {
833 int status;
834 struct dlm_assert_joined assert_msg;
835
836 mlog(0, "Sending join assert to node %u\n", node);
837
838 memset(&assert_msg, 0, sizeof(assert_msg));
839 assert_msg.node_idx = dlm->node_num;
840 assert_msg.name_len = strlen(dlm->name);
841 memcpy(assert_msg.domain, dlm->name, assert_msg.name_len);
842
843 status = o2net_send_message(DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY,
844 &assert_msg, sizeof(assert_msg), node,
845 NULL);
846 if (status < 0)
847 mlog_errno(status);
848
849 return status;
850 }
851
852 static void dlm_send_join_asserts(struct dlm_ctxt *dlm,
853 unsigned long *node_map)
854 {
855 int status, node, live;
856
857 status = 0;
858 node = -1;
859 while ((node = find_next_bit(node_map, O2NM_MAX_NODES,
860 node + 1)) < O2NM_MAX_NODES) {
861 if (node == dlm->node_num)
862 continue;
863
864 do {
865 /* It is very important that this message be
866 * received so we spin until either the node
867 * has died or it gets the message. */
868 status = dlm_send_one_join_assert(dlm, node);
869
870 spin_lock(&dlm->spinlock);
871 live = test_bit(node, dlm->live_nodes_map);
872 spin_unlock(&dlm->spinlock);
873
874 if (status) {
875 mlog(ML_ERROR, "Error return %d asserting "
876 "join on node %d\n", status, node);
877
878 /* give us some time between errors... */
879 if (live)
880 msleep(DLM_DOMAIN_BACKOFF_MS);
881 }
882 } while (status && live);
883 }
884 }
885
886 struct domain_join_ctxt {
887 unsigned long live_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
888 unsigned long yes_resp_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
889 };
890
891 static int dlm_should_restart_join(struct dlm_ctxt *dlm,
892 struct domain_join_ctxt *ctxt,
893 enum dlm_query_join_response response)
894 {
895 int ret;
896
897 if (response == JOIN_DISALLOW) {
898 mlog(0, "Latest response of disallow -- should restart\n");
899 return 1;
900 }
901
902 spin_lock(&dlm->spinlock);
903 /* For now, we restart the process if the node maps have
904 * changed at all */
905 ret = memcmp(ctxt->live_map, dlm->live_nodes_map,
906 sizeof(dlm->live_nodes_map));
907 spin_unlock(&dlm->spinlock);
908
909 if (ret)
910 mlog(0, "Node maps changed -- should restart\n");
911
912 return ret;
913 }
914
915 static int dlm_try_to_join_domain(struct dlm_ctxt *dlm)
916 {
917 int status = 0, tmpstat, node;
918 struct domain_join_ctxt *ctxt;
919 enum dlm_query_join_response response;
920
921 mlog_entry("%p", dlm);
922
923 ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL);
924 if (!ctxt) {
925 status = -ENOMEM;
926 mlog_errno(status);
927 goto bail;
928 }
929
930 /* group sem locking should work for us here -- we're already
931 * registered for heartbeat events so filling this should be
932 * atomic wrt getting those handlers called. */
933 o2hb_fill_node_map(dlm->live_nodes_map, sizeof(dlm->live_nodes_map));
934
935 spin_lock(&dlm->spinlock);
936 memcpy(ctxt->live_map, dlm->live_nodes_map, sizeof(ctxt->live_map));
937
938 __dlm_set_joining_node(dlm, dlm->node_num);
939
940 spin_unlock(&dlm->spinlock);
941
942 node = -1;
943 while ((node = find_next_bit(ctxt->live_map, O2NM_MAX_NODES,
944 node + 1)) < O2NM_MAX_NODES) {
945 if (node == dlm->node_num)
946 continue;
947
948 status = dlm_request_join(dlm, node, &response);
949 if (status < 0) {
950 mlog_errno(status);
951 goto bail;
952 }
953
954 /* Ok, either we got a response or the node doesn't have a
955 * dlm up. */
956 if (response == JOIN_OK)
957 set_bit(node, ctxt->yes_resp_map);
958
959 if (dlm_should_restart_join(dlm, ctxt, response)) {
960 status = -EAGAIN;
961 goto bail;
962 }
963 }
964
965 mlog(0, "Yay, done querying nodes!\n");
966
967 /* Yay, everyone agree's we can join the domain. My domain is
968 * comprised of all nodes who were put in the
969 * yes_resp_map. Copy that into our domain map and send a join
970 * assert message to clean up everyone elses state. */
971 spin_lock(&dlm->spinlock);
972 memcpy(dlm->domain_map, ctxt->yes_resp_map,
973 sizeof(ctxt->yes_resp_map));
974 set_bit(dlm->node_num, dlm->domain_map);
975 spin_unlock(&dlm->spinlock);
976
977 dlm_send_join_asserts(dlm, ctxt->yes_resp_map);
978
979 /* Joined state *must* be set before the joining node
980 * information, otherwise the query_join handler may read no
981 * current joiner but a state of NEW and tell joining nodes
982 * we're not in the domain. */
983 spin_lock(&dlm_domain_lock);
984 dlm->dlm_state = DLM_CTXT_JOINED;
985 dlm->num_joins++;
986 spin_unlock(&dlm_domain_lock);
987
988 bail:
989 spin_lock(&dlm->spinlock);
990 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
991 if (!status)
992 __dlm_print_nodes(dlm);
993 spin_unlock(&dlm->spinlock);
994
995 if (ctxt) {
996 /* Do we need to send a cancel message to any nodes? */
997 if (status < 0) {
998 tmpstat = dlm_send_join_cancels(dlm,
999 ctxt->yes_resp_map,
1000 sizeof(ctxt->yes_resp_map));
1001 if (tmpstat < 0)
1002 mlog_errno(tmpstat);
1003 }
1004 kfree(ctxt);
1005 }
1006
1007 mlog(0, "returning %d\n", status);
1008 return status;
1009 }
1010
1011 static void dlm_unregister_domain_handlers(struct dlm_ctxt *dlm)
1012 {
1013 o2hb_unregister_callback(&dlm->dlm_hb_up);
1014 o2hb_unregister_callback(&dlm->dlm_hb_down);
1015 o2net_unregister_handler_list(&dlm->dlm_domain_handlers);
1016 }
1017
1018 static int dlm_register_domain_handlers(struct dlm_ctxt *dlm)
1019 {
1020 int status;
1021
1022 mlog(0, "registering handlers.\n");
1023
1024 o2hb_setup_callback(&dlm->dlm_hb_down, O2HB_NODE_DOWN_CB,
1025 dlm_hb_node_down_cb, dlm, DLM_HB_NODE_DOWN_PRI);
1026 status = o2hb_register_callback(&dlm->dlm_hb_down);
1027 if (status)
1028 goto bail;
1029
1030 o2hb_setup_callback(&dlm->dlm_hb_up, O2HB_NODE_UP_CB,
1031 dlm_hb_node_up_cb, dlm, DLM_HB_NODE_UP_PRI);
1032 status = o2hb_register_callback(&dlm->dlm_hb_up);
1033 if (status)
1034 goto bail;
1035
1036 status = o2net_register_handler(DLM_MASTER_REQUEST_MSG, dlm->key,
1037 sizeof(struct dlm_master_request),
1038 dlm_master_request_handler,
1039 dlm, &dlm->dlm_domain_handlers);
1040 if (status)
1041 goto bail;
1042
1043 status = o2net_register_handler(DLM_ASSERT_MASTER_MSG, dlm->key,
1044 sizeof(struct dlm_assert_master),
1045 dlm_assert_master_handler,
1046 dlm, &dlm->dlm_domain_handlers);
1047 if (status)
1048 goto bail;
1049
1050 status = o2net_register_handler(DLM_CREATE_LOCK_MSG, dlm->key,
1051 sizeof(struct dlm_create_lock),
1052 dlm_create_lock_handler,
1053 dlm, &dlm->dlm_domain_handlers);
1054 if (status)
1055 goto bail;
1056
1057 status = o2net_register_handler(DLM_CONVERT_LOCK_MSG, dlm->key,
1058 DLM_CONVERT_LOCK_MAX_LEN,
1059 dlm_convert_lock_handler,
1060 dlm, &dlm->dlm_domain_handlers);
1061 if (status)
1062 goto bail;
1063
1064 status = o2net_register_handler(DLM_UNLOCK_LOCK_MSG, dlm->key,
1065 DLM_UNLOCK_LOCK_MAX_LEN,
1066 dlm_unlock_lock_handler,
1067 dlm, &dlm->dlm_domain_handlers);
1068 if (status)
1069 goto bail;
1070
1071 status = o2net_register_handler(DLM_PROXY_AST_MSG, dlm->key,
1072 DLM_PROXY_AST_MAX_LEN,
1073 dlm_proxy_ast_handler,
1074 dlm, &dlm->dlm_domain_handlers);
1075 if (status)
1076 goto bail;
1077
1078 status = o2net_register_handler(DLM_EXIT_DOMAIN_MSG, dlm->key,
1079 sizeof(struct dlm_exit_domain),
1080 dlm_exit_domain_handler,
1081 dlm, &dlm->dlm_domain_handlers);
1082 if (status)
1083 goto bail;
1084
1085 status = o2net_register_handler(DLM_MIGRATE_REQUEST_MSG, dlm->key,
1086 sizeof(struct dlm_migrate_request),
1087 dlm_migrate_request_handler,
1088 dlm, &dlm->dlm_domain_handlers);
1089 if (status)
1090 goto bail;
1091
1092 status = o2net_register_handler(DLM_MIG_LOCKRES_MSG, dlm->key,
1093 DLM_MIG_LOCKRES_MAX_LEN,
1094 dlm_mig_lockres_handler,
1095 dlm, &dlm->dlm_domain_handlers);
1096 if (status)
1097 goto bail;
1098
1099 status = o2net_register_handler(DLM_MASTER_REQUERY_MSG, dlm->key,
1100 sizeof(struct dlm_master_requery),
1101 dlm_master_requery_handler,
1102 dlm, &dlm->dlm_domain_handlers);
1103 if (status)
1104 goto bail;
1105
1106 status = o2net_register_handler(DLM_LOCK_REQUEST_MSG, dlm->key,
1107 sizeof(struct dlm_lock_request),
1108 dlm_request_all_locks_handler,
1109 dlm, &dlm->dlm_domain_handlers);
1110 if (status)
1111 goto bail;
1112
1113 status = o2net_register_handler(DLM_RECO_DATA_DONE_MSG, dlm->key,
1114 sizeof(struct dlm_reco_data_done),
1115 dlm_reco_data_done_handler,
1116 dlm, &dlm->dlm_domain_handlers);
1117 if (status)
1118 goto bail;
1119
1120 status = o2net_register_handler(DLM_BEGIN_RECO_MSG, dlm->key,
1121 sizeof(struct dlm_begin_reco),
1122 dlm_begin_reco_handler,
1123 dlm, &dlm->dlm_domain_handlers);
1124 if (status)
1125 goto bail;
1126
1127 status = o2net_register_handler(DLM_FINALIZE_RECO_MSG, dlm->key,
1128 sizeof(struct dlm_finalize_reco),
1129 dlm_finalize_reco_handler,
1130 dlm, &dlm->dlm_domain_handlers);
1131 if (status)
1132 goto bail;
1133
1134 bail:
1135 if (status)
1136 dlm_unregister_domain_handlers(dlm);
1137
1138 return status;
1139 }
1140
1141 static int dlm_join_domain(struct dlm_ctxt *dlm)
1142 {
1143 int status;
1144
1145 BUG_ON(!dlm);
1146
1147 mlog(0, "Join domain %s\n", dlm->name);
1148
1149 status = dlm_register_domain_handlers(dlm);
1150 if (status) {
1151 mlog_errno(status);
1152 goto bail;
1153 }
1154
1155 status = dlm_launch_thread(dlm);
1156 if (status < 0) {
1157 mlog_errno(status);
1158 goto bail;
1159 }
1160
1161 status = dlm_launch_recovery_thread(dlm);
1162 if (status < 0) {
1163 mlog_errno(status);
1164 goto bail;
1165 }
1166
1167 dlm->dlm_worker = create_singlethread_workqueue("dlm_wq");
1168 if (!dlm->dlm_worker) {
1169 status = -ENOMEM;
1170 mlog_errno(status);
1171 goto bail;
1172 }
1173
1174 do {
1175 unsigned int backoff;
1176 status = dlm_try_to_join_domain(dlm);
1177
1178 /* If we're racing another node to the join, then we
1179 * need to back off temporarily and let them
1180 * complete. */
1181 if (status == -EAGAIN) {
1182 if (signal_pending(current)) {
1183 status = -ERESTARTSYS;
1184 goto bail;
1185 }
1186
1187 /*
1188 * <chip> After you!
1189 * <dale> No, after you!
1190 * <chip> I insist!
1191 * <dale> But you first!
1192 * ...
1193 */
1194 backoff = (unsigned int)(jiffies & 0x3);
1195 backoff *= DLM_DOMAIN_BACKOFF_MS;
1196 mlog(0, "backoff %d\n", backoff);
1197 msleep(backoff);
1198 }
1199 } while (status == -EAGAIN);
1200
1201 if (status < 0) {
1202 mlog_errno(status);
1203 goto bail;
1204 }
1205
1206 status = 0;
1207 bail:
1208 wake_up(&dlm_domain_events);
1209
1210 if (status) {
1211 dlm_unregister_domain_handlers(dlm);
1212 dlm_complete_thread(dlm);
1213 dlm_complete_recovery_thread(dlm);
1214 dlm_destroy_dlm_worker(dlm);
1215 }
1216
1217 return status;
1218 }
1219
1220 static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain,
1221 u32 key)
1222 {
1223 int i;
1224 struct dlm_ctxt *dlm = NULL;
1225
1226 dlm = kzalloc(sizeof(*dlm), GFP_KERNEL);
1227 if (!dlm) {
1228 mlog_errno(-ENOMEM);
1229 goto leave;
1230 }
1231
1232 dlm->name = kmalloc(strlen(domain) + 1, GFP_KERNEL);
1233 if (dlm->name == NULL) {
1234 mlog_errno(-ENOMEM);
1235 kfree(dlm);
1236 dlm = NULL;
1237 goto leave;
1238 }
1239
1240 dlm->lockres_hash = (struct hlist_head **)dlm_alloc_pagevec(DLM_HASH_PAGES);
1241 if (!dlm->lockres_hash) {
1242 mlog_errno(-ENOMEM);
1243 kfree(dlm->name);
1244 kfree(dlm);
1245 dlm = NULL;
1246 goto leave;
1247 }
1248
1249 for (i = 0; i < DLM_HASH_BUCKETS; i++)
1250 INIT_HLIST_HEAD(dlm_lockres_hash(dlm, i));
1251
1252 strcpy(dlm->name, domain);
1253 dlm->key = key;
1254 dlm->node_num = o2nm_this_node();
1255
1256 spin_lock_init(&dlm->spinlock);
1257 spin_lock_init(&dlm->master_lock);
1258 spin_lock_init(&dlm->ast_lock);
1259 INIT_LIST_HEAD(&dlm->list);
1260 INIT_LIST_HEAD(&dlm->dirty_list);
1261 INIT_LIST_HEAD(&dlm->reco.resources);
1262 INIT_LIST_HEAD(&dlm->reco.received);
1263 INIT_LIST_HEAD(&dlm->reco.node_data);
1264 INIT_LIST_HEAD(&dlm->purge_list);
1265 INIT_LIST_HEAD(&dlm->dlm_domain_handlers);
1266 dlm->reco.state = 0;
1267
1268 INIT_LIST_HEAD(&dlm->pending_asts);
1269 INIT_LIST_HEAD(&dlm->pending_basts);
1270
1271 mlog(0, "dlm->recovery_map=%p, &(dlm->recovery_map[0])=%p\n",
1272 dlm->recovery_map, &(dlm->recovery_map[0]));
1273
1274 memset(dlm->recovery_map, 0, sizeof(dlm->recovery_map));
1275 memset(dlm->live_nodes_map, 0, sizeof(dlm->live_nodes_map));
1276 memset(dlm->domain_map, 0, sizeof(dlm->domain_map));
1277
1278 dlm->dlm_thread_task = NULL;
1279 dlm->dlm_reco_thread_task = NULL;
1280 dlm->dlm_worker = NULL;
1281 init_waitqueue_head(&dlm->dlm_thread_wq);
1282 init_waitqueue_head(&dlm->dlm_reco_thread_wq);
1283 init_waitqueue_head(&dlm->reco.event);
1284 init_waitqueue_head(&dlm->ast_wq);
1285 init_waitqueue_head(&dlm->migration_wq);
1286 INIT_LIST_HEAD(&dlm->master_list);
1287 INIT_LIST_HEAD(&dlm->mle_hb_events);
1288
1289 dlm->joining_node = DLM_LOCK_RES_OWNER_UNKNOWN;
1290 init_waitqueue_head(&dlm->dlm_join_events);
1291
1292 dlm->reco.new_master = O2NM_INVALID_NODE_NUM;
1293 dlm->reco.dead_node = O2NM_INVALID_NODE_NUM;
1294 atomic_set(&dlm->local_resources, 0);
1295 atomic_set(&dlm->remote_resources, 0);
1296 atomic_set(&dlm->unknown_resources, 0);
1297
1298 spin_lock_init(&dlm->work_lock);
1299 INIT_LIST_HEAD(&dlm->work_list);
1300 INIT_WORK(&dlm->dispatched_work, dlm_dispatch_work);
1301
1302 kref_init(&dlm->dlm_refs);
1303 dlm->dlm_state = DLM_CTXT_NEW;
1304
1305 INIT_LIST_HEAD(&dlm->dlm_eviction_callbacks);
1306
1307 mlog(0, "context init: refcount %u\n",
1308 atomic_read(&dlm->dlm_refs.refcount));
1309
1310 leave:
1311 return dlm;
1312 }
1313
1314 /*
1315 * dlm_register_domain: one-time setup per "domain"
1316 */
1317 struct dlm_ctxt * dlm_register_domain(const char *domain,
1318 u32 key)
1319 {
1320 int ret;
1321 struct dlm_ctxt *dlm = NULL;
1322 struct dlm_ctxt *new_ctxt = NULL;
1323
1324 if (strlen(domain) > O2NM_MAX_NAME_LEN) {
1325 ret = -ENAMETOOLONG;
1326 mlog(ML_ERROR, "domain name length too long\n");
1327 goto leave;
1328 }
1329
1330 if (!o2hb_check_local_node_heartbeating()) {
1331 mlog(ML_ERROR, "the local node has not been configured, or is "
1332 "not heartbeating\n");
1333 ret = -EPROTO;
1334 goto leave;
1335 }
1336
1337 mlog(0, "register called for domain \"%s\"\n", domain);
1338
1339 retry:
1340 dlm = NULL;
1341 if (signal_pending(current)) {
1342 ret = -ERESTARTSYS;
1343 mlog_errno(ret);
1344 goto leave;
1345 }
1346
1347 spin_lock(&dlm_domain_lock);
1348
1349 dlm = __dlm_lookup_domain(domain);
1350 if (dlm) {
1351 if (dlm->dlm_state != DLM_CTXT_JOINED) {
1352 spin_unlock(&dlm_domain_lock);
1353
1354 mlog(0, "This ctxt is not joined yet!\n");
1355 wait_event_interruptible(dlm_domain_events,
1356 dlm_wait_on_domain_helper(
1357 domain));
1358 goto retry;
1359 }
1360
1361 __dlm_get(dlm);
1362 dlm->num_joins++;
1363
1364 spin_unlock(&dlm_domain_lock);
1365
1366 ret = 0;
1367 goto leave;
1368 }
1369
1370 /* doesn't exist */
1371 if (!new_ctxt) {
1372 spin_unlock(&dlm_domain_lock);
1373
1374 new_ctxt = dlm_alloc_ctxt(domain, key);
1375 if (new_ctxt)
1376 goto retry;
1377
1378 ret = -ENOMEM;
1379 mlog_errno(ret);
1380 goto leave;
1381 }
1382
1383 /* a little variable switch-a-roo here... */
1384 dlm = new_ctxt;
1385 new_ctxt = NULL;
1386
1387 /* add the new domain */
1388 list_add_tail(&dlm->list, &dlm_domains);
1389 spin_unlock(&dlm_domain_lock);
1390
1391 ret = dlm_join_domain(dlm);
1392 if (ret) {
1393 mlog_errno(ret);
1394 dlm_put(dlm);
1395 goto leave;
1396 }
1397
1398 ret = 0;
1399 leave:
1400 if (new_ctxt)
1401 dlm_free_ctxt_mem(new_ctxt);
1402
1403 if (ret < 0)
1404 dlm = ERR_PTR(ret);
1405
1406 return dlm;
1407 }
1408 EXPORT_SYMBOL_GPL(dlm_register_domain);
1409
1410 static LIST_HEAD(dlm_join_handlers);
1411
1412 static void dlm_unregister_net_handlers(void)
1413 {
1414 o2net_unregister_handler_list(&dlm_join_handlers);
1415 }
1416
1417 static int dlm_register_net_handlers(void)
1418 {
1419 int status = 0;
1420
1421 status = o2net_register_handler(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY,
1422 sizeof(struct dlm_query_join_request),
1423 dlm_query_join_handler,
1424 NULL, &dlm_join_handlers);
1425 if (status)
1426 goto bail;
1427
1428 status = o2net_register_handler(DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY,
1429 sizeof(struct dlm_assert_joined),
1430 dlm_assert_joined_handler,
1431 NULL, &dlm_join_handlers);
1432 if (status)
1433 goto bail;
1434
1435 status = o2net_register_handler(DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY,
1436 sizeof(struct dlm_cancel_join),
1437 dlm_cancel_join_handler,
1438 NULL, &dlm_join_handlers);
1439
1440 bail:
1441 if (status < 0)
1442 dlm_unregister_net_handlers();
1443
1444 return status;
1445 }
1446
1447 /* Domain eviction callback handling.
1448 *
1449 * The file system requires notification of node death *before* the
1450 * dlm completes it's recovery work, otherwise it may be able to
1451 * acquire locks on resources requiring recovery. Since the dlm can
1452 * evict a node from it's domain *before* heartbeat fires, a similar
1453 * mechanism is required. */
1454
1455 /* Eviction is not expected to happen often, so a per-domain lock is
1456 * not necessary. Eviction callbacks are allowed to sleep for short
1457 * periods of time. */
1458 static DECLARE_RWSEM(dlm_callback_sem);
1459
1460 void dlm_fire_domain_eviction_callbacks(struct dlm_ctxt *dlm,
1461 int node_num)
1462 {
1463 struct list_head *iter;
1464 struct dlm_eviction_cb *cb;
1465
1466 down_read(&dlm_callback_sem);
1467 list_for_each(iter, &dlm->dlm_eviction_callbacks) {
1468 cb = list_entry(iter, struct dlm_eviction_cb, ec_item);
1469
1470 cb->ec_func(node_num, cb->ec_data);
1471 }
1472 up_read(&dlm_callback_sem);
1473 }
1474
1475 void dlm_setup_eviction_cb(struct dlm_eviction_cb *cb,
1476 dlm_eviction_func *f,
1477 void *data)
1478 {
1479 INIT_LIST_HEAD(&cb->ec_item);
1480 cb->ec_func = f;
1481 cb->ec_data = data;
1482 }
1483 EXPORT_SYMBOL_GPL(dlm_setup_eviction_cb);
1484
1485 void dlm_register_eviction_cb(struct dlm_ctxt *dlm,
1486 struct dlm_eviction_cb *cb)
1487 {
1488 down_write(&dlm_callback_sem);
1489 list_add_tail(&cb->ec_item, &dlm->dlm_eviction_callbacks);
1490 up_write(&dlm_callback_sem);
1491 }
1492 EXPORT_SYMBOL_GPL(dlm_register_eviction_cb);
1493
1494 void dlm_unregister_eviction_cb(struct dlm_eviction_cb *cb)
1495 {
1496 down_write(&dlm_callback_sem);
1497 list_del_init(&cb->ec_item);
1498 up_write(&dlm_callback_sem);
1499 }
1500 EXPORT_SYMBOL_GPL(dlm_unregister_eviction_cb);
1501
1502 static int __init dlm_init(void)
1503 {
1504 int status;
1505
1506 dlm_print_version();
1507
1508 status = dlm_init_mle_cache();
1509 if (status)
1510 return -1;
1511
1512 status = dlm_register_net_handlers();
1513 if (status) {
1514 dlm_destroy_mle_cache();
1515 return -1;
1516 }
1517
1518 return 0;
1519 }
1520
1521 static void __exit dlm_exit (void)
1522 {
1523 dlm_unregister_net_handlers();
1524 dlm_destroy_mle_cache();
1525 }
1526
1527 MODULE_AUTHOR("Oracle");
1528 MODULE_LICENSE("GPL");
1529
1530 module_init(dlm_init);
1531 module_exit(dlm_exit);
Linux kernel - Deliverables
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