?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Merge master.kernel.org:/pub/scm/linux/kernel/git/perex/alsa
[wrt350n-kernel.git] / fs / ocfs2 / dlm / dlmdomain.c
blob8d1065f8b3bdbaf7ccc5def928c4954ea3bd4a24
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 printk(KERN_INFO "ocfs2_dlm: Nodes in domain (\"%s\"): ", dlm->name);
412
413 while ((node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES,
414 node + 1)) < O2NM_MAX_NODES) {
415 printk("%d ", node);
416 }
417 printk("\n");
418 }
419
420 static int dlm_exit_domain_handler(struct o2net_msg *msg, u32 len, void *data)
421 {
422 struct dlm_ctxt *dlm = data;
423 unsigned int node;
424 struct dlm_exit_domain *exit_msg = (struct dlm_exit_domain *) msg->buf;
425
426 mlog_entry("%p %u %p", msg, len, data);
427
428 if (!dlm_grab(dlm))
429 return 0;
430
431 node = exit_msg->node_idx;
432
433 printk(KERN_INFO "ocfs2_dlm: Node %u leaves domain %s\n", node, dlm->name);
434
435 spin_lock(&dlm->spinlock);
436 clear_bit(node, dlm->domain_map);
437 __dlm_print_nodes(dlm);
438
439 /* notify anything attached to the heartbeat events */
440 dlm_hb_event_notify_attached(dlm, node, 0);
441
442 spin_unlock(&dlm->spinlock);
443
444 dlm_put(dlm);
445
446 return 0;
447 }
448
449 static int dlm_send_one_domain_exit(struct dlm_ctxt *dlm,
450 unsigned int node)
451 {
452 int status;
453 struct dlm_exit_domain leave_msg;
454
455 mlog(0, "Asking node %u if we can leave the domain %s me = %u\n",
456 node, dlm->name, dlm->node_num);
457
458 memset(&leave_msg, 0, sizeof(leave_msg));
459 leave_msg.node_idx = dlm->node_num;
460
461 status = o2net_send_message(DLM_EXIT_DOMAIN_MSG, dlm->key,
462 &leave_msg, sizeof(leave_msg), node,
463 NULL);
464
465 mlog(0, "status return %d from o2net_send_message\n", status);
466
467 return status;
468 }
469
470
471 static void dlm_leave_domain(struct dlm_ctxt *dlm)
472 {
473 int node, clear_node, status;
474
475 /* At this point we've migrated away all our locks and won't
476 * accept mastership of new ones. The dlm is responsible for
477 * almost nothing now. We make sure not to confuse any joining
478 * nodes and then commence shutdown procedure. */
479
480 spin_lock(&dlm->spinlock);
481 /* Clear ourselves from the domain map */
482 clear_bit(dlm->node_num, dlm->domain_map);
483 while ((node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES,
484 0)) < O2NM_MAX_NODES) {
485 /* Drop the dlm spinlock. This is safe wrt the domain_map.
486 * -nodes cannot be added now as the
487 * query_join_handlers knows to respond with OK_NO_MAP
488 * -we catch the right network errors if a node is
489 * removed from the map while we're sending him the
490 * exit message. */
491 spin_unlock(&dlm->spinlock);
492
493 clear_node = 1;
494
495 status = dlm_send_one_domain_exit(dlm, node);
496 if (status < 0 &&
497 status != -ENOPROTOOPT &&
498 status != -ENOTCONN) {
499 mlog(ML_NOTICE, "Error %d sending domain exit message "
500 "to node %d\n", status, node);
501
502 /* Not sure what to do here but lets sleep for
503 * a bit in case this was a transient
504 * error... */
505 msleep(DLM_DOMAIN_BACKOFF_MS);
506 clear_node = 0;
507 }
508
509 spin_lock(&dlm->spinlock);
510 /* If we're not clearing the node bit then we intend
511 * to loop back around to try again. */
512 if (clear_node)
513 clear_bit(node, dlm->domain_map);
514 }
515 spin_unlock(&dlm->spinlock);
516 }
517
518 int dlm_joined(struct dlm_ctxt *dlm)
519 {
520 int ret = 0;
521
522 spin_lock(&dlm_domain_lock);
523
524 if (dlm->dlm_state == DLM_CTXT_JOINED)
525 ret = 1;
526
527 spin_unlock(&dlm_domain_lock);
528
529 return ret;
530 }
531
532 int dlm_shutting_down(struct dlm_ctxt *dlm)
533 {
534 int ret = 0;
535
536 spin_lock(&dlm_domain_lock);
537
538 if (dlm->dlm_state == DLM_CTXT_IN_SHUTDOWN)
539 ret = 1;
540
541 spin_unlock(&dlm_domain_lock);
542
543 return ret;
544 }
545
546 void dlm_unregister_domain(struct dlm_ctxt *dlm)
547 {
548 int leave = 0;
549
550 spin_lock(&dlm_domain_lock);
551 BUG_ON(dlm->dlm_state != DLM_CTXT_JOINED);
552 BUG_ON(!dlm->num_joins);
553
554 dlm->num_joins--;
555 if (!dlm->num_joins) {
556 /* We mark it "in shutdown" now so new register
557 * requests wait until we've completely left the
558 * domain. Don't use DLM_CTXT_LEAVING yet as we still
559 * want new domain joins to communicate with us at
560 * least until we've completed migration of our
561 * resources. */
562 dlm->dlm_state = DLM_CTXT_IN_SHUTDOWN;
563 leave = 1;
564 }
565 spin_unlock(&dlm_domain_lock);
566
567 if (leave) {
568 mlog(0, "shutting down domain %s\n", dlm->name);
569
570 /* We changed dlm state, notify the thread */
571 dlm_kick_thread(dlm, NULL);
572
573 dlm_migrate_all_locks(dlm);
574 dlm_mark_domain_leaving(dlm);
575 dlm_leave_domain(dlm);
576 dlm_complete_dlm_shutdown(dlm);
577 }
578 dlm_put(dlm);
579 }
580 EXPORT_SYMBOL_GPL(dlm_unregister_domain);
581
582 static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data)
583 {
584 struct dlm_query_join_request *query;
585 enum dlm_query_join_response response;
586 struct dlm_ctxt *dlm = NULL;
587
588 query = (struct dlm_query_join_request *) msg->buf;
589
590 mlog(0, "node %u wants to join domain %s\n", query->node_idx,
591 query->domain);
592
593 /*
594 * If heartbeat doesn't consider the node live, tell it
595 * to back off and try again. This gives heartbeat a chance
596 * to catch up.
597 */
598 if (!o2hb_check_node_heartbeating(query->node_idx)) {
599 mlog(0, "node %u is not in our live map yet\n",
600 query->node_idx);
601
602 response = JOIN_DISALLOW;
603 goto respond;
604 }
605
606 response = JOIN_OK_NO_MAP;
607
608 spin_lock(&dlm_domain_lock);
609 dlm = __dlm_lookup_domain_full(query->domain, query->name_len);
610 /* Once the dlm ctxt is marked as leaving then we don't want
611 * to be put in someone's domain map.
612 * Also, explicitly disallow joining at certain troublesome
613 * times (ie. during recovery). */
614 if (dlm && dlm->dlm_state != DLM_CTXT_LEAVING) {
615 int bit = query->node_idx;
616 spin_lock(&dlm->spinlock);
617
618 if (dlm->dlm_state == DLM_CTXT_NEW &&
619 dlm->joining_node == DLM_LOCK_RES_OWNER_UNKNOWN) {
620 /*If this is a brand new context and we
621 * haven't started our join process yet, then
622 * the other node won the race. */
623 response = JOIN_OK_NO_MAP;
624 } else if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) {
625 /* Disallow parallel joins. */
626 response = JOIN_DISALLOW;
627 } else if (dlm->reco.state & DLM_RECO_STATE_ACTIVE) {
628 mlog(ML_NOTICE, "node %u trying to join, but recovery "
629 "is ongoing.\n", bit);
630 response = JOIN_DISALLOW;
631 } else if (test_bit(bit, dlm->recovery_map)) {
632 mlog(ML_NOTICE, "node %u trying to join, but it "
633 "still needs recovery.\n", bit);
634 response = JOIN_DISALLOW;
635 } else if (test_bit(bit, dlm->domain_map)) {
636 mlog(ML_NOTICE, "node %u trying to join, but it "
637 "is still in the domain! needs recovery?\n",
638 bit);
639 response = JOIN_DISALLOW;
640 } else {
641 /* Alright we're fully a part of this domain
642 * so we keep some state as to who's joining
643 * and indicate to him that needs to be fixed
644 * up. */
645 response = JOIN_OK;
646 __dlm_set_joining_node(dlm, query->node_idx);
647 }
648
649 spin_unlock(&dlm->spinlock);
650 }
651 spin_unlock(&dlm_domain_lock);
652
653 respond:
654 mlog(0, "We respond with %u\n", response);
655
656 return response;
657 }
658
659 static int dlm_assert_joined_handler(struct o2net_msg *msg, u32 len, void *data)
660 {
661 struct dlm_assert_joined *assert;
662 struct dlm_ctxt *dlm = NULL;
663
664 assert = (struct dlm_assert_joined *) msg->buf;
665
666 mlog(0, "node %u asserts join on domain %s\n", assert->node_idx,
667 assert->domain);
668
669 spin_lock(&dlm_domain_lock);
670 dlm = __dlm_lookup_domain_full(assert->domain, assert->name_len);
671 /* XXX should we consider no dlm ctxt an error? */
672 if (dlm) {
673 spin_lock(&dlm->spinlock);
674
675 /* Alright, this node has officially joined our
676 * domain. Set him in the map and clean up our
677 * leftover join state. */
678 BUG_ON(dlm->joining_node != assert->node_idx);
679 set_bit(assert->node_idx, dlm->domain_map);
680 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
681
682 printk(KERN_INFO "ocfs2_dlm: Node %u joins domain %s\n",
683 assert->node_idx, dlm->name);
684 __dlm_print_nodes(dlm);
685
686 /* notify anything attached to the heartbeat events */
687 dlm_hb_event_notify_attached(dlm, assert->node_idx, 1);
688
689 spin_unlock(&dlm->spinlock);
690 }
691 spin_unlock(&dlm_domain_lock);
692
693 return 0;
694 }
695
696 static int dlm_cancel_join_handler(struct o2net_msg *msg, u32 len, void *data)
697 {
698 struct dlm_cancel_join *cancel;
699 struct dlm_ctxt *dlm = NULL;
700
701 cancel = (struct dlm_cancel_join *) msg->buf;
702
703 mlog(0, "node %u cancels join on domain %s\n", cancel->node_idx,
704 cancel->domain);
705
706 spin_lock(&dlm_domain_lock);
707 dlm = __dlm_lookup_domain_full(cancel->domain, cancel->name_len);
708
709 if (dlm) {
710 spin_lock(&dlm->spinlock);
711
712 /* Yikes, this guy wants to cancel his join. No
713 * problem, we simply cleanup our join state. */
714 BUG_ON(dlm->joining_node != cancel->node_idx);
715 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
716
717 spin_unlock(&dlm->spinlock);
718 }
719 spin_unlock(&dlm_domain_lock);
720
721 return 0;
722 }
723
724 static int dlm_send_one_join_cancel(struct dlm_ctxt *dlm,
725 unsigned int node)
726 {
727 int status;
728 struct dlm_cancel_join cancel_msg;
729
730 memset(&cancel_msg, 0, sizeof(cancel_msg));
731 cancel_msg.node_idx = dlm->node_num;
732 cancel_msg.name_len = strlen(dlm->name);
733 memcpy(cancel_msg.domain, dlm->name, cancel_msg.name_len);
734
735 status = o2net_send_message(DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY,
736 &cancel_msg, sizeof(cancel_msg), node,
737 NULL);
738 if (status < 0) {
739 mlog_errno(status);
740 goto bail;
741 }
742
743 bail:
744 return status;
745 }
746
747 /* map_size should be in bytes. */
748 static int dlm_send_join_cancels(struct dlm_ctxt *dlm,
749 unsigned long *node_map,
750 unsigned int map_size)
751 {
752 int status, tmpstat;
753 unsigned int node;
754
755 if (map_size != (BITS_TO_LONGS(O2NM_MAX_NODES) *
756 sizeof(unsigned long))) {
757 mlog(ML_ERROR,
758 "map_size %u != BITS_TO_LONGS(O2NM_MAX_NODES) %u\n",
759 map_size, BITS_TO_LONGS(O2NM_MAX_NODES));
760 return -EINVAL;
761 }
762
763 status = 0;
764 node = -1;
765 while ((node = find_next_bit(node_map, O2NM_MAX_NODES,
766 node + 1)) < O2NM_MAX_NODES) {
767 if (node == dlm->node_num)
768 continue;
769
770 tmpstat = dlm_send_one_join_cancel(dlm, node);
771 if (tmpstat) {
772 mlog(ML_ERROR, "Error return %d cancelling join on "
773 "node %d\n", tmpstat, node);
774 if (!status)
775 status = tmpstat;
776 }
777 }
778
779 if (status)
780 mlog_errno(status);
781 return status;
782 }
783
784 static int dlm_request_join(struct dlm_ctxt *dlm,
785 int node,
786 enum dlm_query_join_response *response)
787 {
788 int status, retval;
789 struct dlm_query_join_request join_msg;
790
791 mlog(0, "querying node %d\n", node);
792
793 memset(&join_msg, 0, sizeof(join_msg));
794 join_msg.node_idx = dlm->node_num;
795 join_msg.name_len = strlen(dlm->name);
796 memcpy(join_msg.domain, dlm->name, join_msg.name_len);
797
798 status = o2net_send_message(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY, &join_msg,
799 sizeof(join_msg), node, &retval);
800 if (status < 0 && status != -ENOPROTOOPT) {
801 mlog_errno(status);
802 goto bail;
803 }
804
805 /* -ENOPROTOOPT from the net code means the other side isn't
806 listening for our message type -- that's fine, it means
807 his dlm isn't up, so we can consider him a 'yes' but not
808 joined into the domain. */
809 if (status == -ENOPROTOOPT) {
810 status = 0;
811 *response = JOIN_OK_NO_MAP;
812 } else if (retval == JOIN_DISALLOW ||
813 retval == JOIN_OK ||
814 retval == JOIN_OK_NO_MAP) {
815 *response = retval;
816 } else {
817 status = -EINVAL;
818 mlog(ML_ERROR, "invalid response %d from node %u\n", retval,
819 node);
820 }
821
822 mlog(0, "status %d, node %d response is %d\n", status, node,
823 *response);
824
825 bail:
826 return status;
827 }
828
829 static int dlm_send_one_join_assert(struct dlm_ctxt *dlm,
830 unsigned int node)
831 {
832 int status;
833 struct dlm_assert_joined assert_msg;
834
835 mlog(0, "Sending join assert to node %u\n", node);
836
837 memset(&assert_msg, 0, sizeof(assert_msg));
838 assert_msg.node_idx = dlm->node_num;
839 assert_msg.name_len = strlen(dlm->name);
840 memcpy(assert_msg.domain, dlm->name, assert_msg.name_len);
841
842 status = o2net_send_message(DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY,
843 &assert_msg, sizeof(assert_msg), node,
844 NULL);
845 if (status < 0)
846 mlog_errno(status);
847
848 return status;
849 }
850
851 static void dlm_send_join_asserts(struct dlm_ctxt *dlm,
852 unsigned long *node_map)
853 {
854 int status, node, live;
855
856 status = 0;
857 node = -1;
858 while ((node = find_next_bit(node_map, O2NM_MAX_NODES,
859 node + 1)) < O2NM_MAX_NODES) {
860 if (node == dlm->node_num)
861 continue;
862
863 do {
864 /* It is very important that this message be
865 * received so we spin until either the node
866 * has died or it gets the message. */
867 status = dlm_send_one_join_assert(dlm, node);
868
869 spin_lock(&dlm->spinlock);
870 live = test_bit(node, dlm->live_nodes_map);
871 spin_unlock(&dlm->spinlock);
872
873 if (status) {
874 mlog(ML_ERROR, "Error return %d asserting "
875 "join on node %d\n", status, node);
876
877 /* give us some time between errors... */
878 if (live)
879 msleep(DLM_DOMAIN_BACKOFF_MS);
880 }
881 } while (status && live);
882 }
883 }
884
885 struct domain_join_ctxt {
886 unsigned long live_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
887 unsigned long yes_resp_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
888 };
889
890 static int dlm_should_restart_join(struct dlm_ctxt *dlm,
891 struct domain_join_ctxt *ctxt,
892 enum dlm_query_join_response response)
893 {
894 int ret;
895
896 if (response == JOIN_DISALLOW) {
897 mlog(0, "Latest response of disallow -- should restart\n");
898 return 1;
899 }
900
901 spin_lock(&dlm->spinlock);
902 /* For now, we restart the process if the node maps have
903 * changed at all */
904 ret = memcmp(ctxt->live_map, dlm->live_nodes_map,
905 sizeof(dlm->live_nodes_map));
906 spin_unlock(&dlm->spinlock);
907
908 if (ret)
909 mlog(0, "Node maps changed -- should restart\n");
910
911 return ret;
912 }
913
914 static int dlm_try_to_join_domain(struct dlm_ctxt *dlm)
915 {
916 int status = 0, tmpstat, node;
917 struct domain_join_ctxt *ctxt;
918 enum dlm_query_join_response response;
919
920 mlog_entry("%p", dlm);
921
922 ctxt = kcalloc(1, sizeof(*ctxt), GFP_KERNEL);
923 if (!ctxt) {
924 status = -ENOMEM;
925 mlog_errno(status);
926 goto bail;
927 }
928
929 /* group sem locking should work for us here -- we're already
930 * registered for heartbeat events so filling this should be
931 * atomic wrt getting those handlers called. */
932 o2hb_fill_node_map(dlm->live_nodes_map, sizeof(dlm->live_nodes_map));
933
934 spin_lock(&dlm->spinlock);
935 memcpy(ctxt->live_map, dlm->live_nodes_map, sizeof(ctxt->live_map));
936
937 __dlm_set_joining_node(dlm, dlm->node_num);
938
939 spin_unlock(&dlm->spinlock);
940
941 node = -1;
942 while ((node = find_next_bit(ctxt->live_map, O2NM_MAX_NODES,
943 node + 1)) < O2NM_MAX_NODES) {
944 if (node == dlm->node_num)
945 continue;
946
947 status = dlm_request_join(dlm, node, &response);
948 if (status < 0) {
949 mlog_errno(status);
950 goto bail;
951 }
952
953 /* Ok, either we got a response or the node doesn't have a
954 * dlm up. */
955 if (response == JOIN_OK)
956 set_bit(node, ctxt->yes_resp_map);
957
958 if (dlm_should_restart_join(dlm, ctxt, response)) {
959 status = -EAGAIN;
960 goto bail;
961 }
962 }
963
964 mlog(0, "Yay, done querying nodes!\n");
965
966 /* Yay, everyone agree's we can join the domain. My domain is
967 * comprised of all nodes who were put in the
968 * yes_resp_map. Copy that into our domain map and send a join
969 * assert message to clean up everyone elses state. */
970 spin_lock(&dlm->spinlock);
971 memcpy(dlm->domain_map, ctxt->yes_resp_map,
972 sizeof(ctxt->yes_resp_map));
973 set_bit(dlm->node_num, dlm->domain_map);
974 spin_unlock(&dlm->spinlock);
975
976 dlm_send_join_asserts(dlm, ctxt->yes_resp_map);
977
978 /* Joined state *must* be set before the joining node
979 * information, otherwise the query_join handler may read no
980 * current joiner but a state of NEW and tell joining nodes
981 * we're not in the domain. */
982 spin_lock(&dlm_domain_lock);
983 dlm->dlm_state = DLM_CTXT_JOINED;
984 dlm->num_joins++;
985 spin_unlock(&dlm_domain_lock);
986
987 bail:
988 spin_lock(&dlm->spinlock);
989 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
990 if (!status)
991 __dlm_print_nodes(dlm);
992 spin_unlock(&dlm->spinlock);
993
994 if (ctxt) {
995 /* Do we need to send a cancel message to any nodes? */
996 if (status < 0) {
997 tmpstat = dlm_send_join_cancels(dlm,
998 ctxt->yes_resp_map,
999 sizeof(ctxt->yes_resp_map));
1000 if (tmpstat < 0)
1001 mlog_errno(tmpstat);
1002 }
1003 kfree(ctxt);
1004 }
1005
1006 mlog(0, "returning %d\n", status);
1007 return status;
1008 }
1009
1010 static void dlm_unregister_domain_handlers(struct dlm_ctxt *dlm)
1011 {
1012 o2hb_unregister_callback(&dlm->dlm_hb_up);
1013 o2hb_unregister_callback(&dlm->dlm_hb_down);
1014 o2net_unregister_handler_list(&dlm->dlm_domain_handlers);
1015 }
1016
1017 static int dlm_register_domain_handlers(struct dlm_ctxt *dlm)
1018 {
1019 int status;
1020
1021 mlog(0, "registering handlers.\n");
1022
1023 o2hb_setup_callback(&dlm->dlm_hb_down, O2HB_NODE_DOWN_CB,
1024 dlm_hb_node_down_cb, dlm, DLM_HB_NODE_DOWN_PRI);
1025 status = o2hb_register_callback(&dlm->dlm_hb_down);
1026 if (status)
1027 goto bail;
1028
1029 o2hb_setup_callback(&dlm->dlm_hb_up, O2HB_NODE_UP_CB,
1030 dlm_hb_node_up_cb, dlm, DLM_HB_NODE_UP_PRI);
1031 status = o2hb_register_callback(&dlm->dlm_hb_up);
1032 if (status)
1033 goto bail;
1034
1035 status = o2net_register_handler(DLM_MASTER_REQUEST_MSG, dlm->key,
1036 sizeof(struct dlm_master_request),
1037 dlm_master_request_handler,
1038 dlm, &dlm->dlm_domain_handlers);
1039 if (status)
1040 goto bail;
1041
1042 status = o2net_register_handler(DLM_ASSERT_MASTER_MSG, dlm->key,
1043 sizeof(struct dlm_assert_master),
1044 dlm_assert_master_handler,
1045 dlm, &dlm->dlm_domain_handlers);
1046 if (status)
1047 goto bail;
1048
1049 status = o2net_register_handler(DLM_CREATE_LOCK_MSG, dlm->key,
1050 sizeof(struct dlm_create_lock),
1051 dlm_create_lock_handler,
1052 dlm, &dlm->dlm_domain_handlers);
1053 if (status)
1054 goto bail;
1055
1056 status = o2net_register_handler(DLM_CONVERT_LOCK_MSG, dlm->key,
1057 DLM_CONVERT_LOCK_MAX_LEN,
1058 dlm_convert_lock_handler,
1059 dlm, &dlm->dlm_domain_handlers);
1060 if (status)
1061 goto bail;
1062
1063 status = o2net_register_handler(DLM_UNLOCK_LOCK_MSG, dlm->key,
1064 DLM_UNLOCK_LOCK_MAX_LEN,
1065 dlm_unlock_lock_handler,
1066 dlm, &dlm->dlm_domain_handlers);
1067 if (status)
1068 goto bail;
1069
1070 status = o2net_register_handler(DLM_PROXY_AST_MSG, dlm->key,
1071 DLM_PROXY_AST_MAX_LEN,
1072 dlm_proxy_ast_handler,
1073 dlm, &dlm->dlm_domain_handlers);
1074 if (status)
1075 goto bail;
1076
1077 status = o2net_register_handler(DLM_EXIT_DOMAIN_MSG, dlm->key,
1078 sizeof(struct dlm_exit_domain),
1079 dlm_exit_domain_handler,
1080 dlm, &dlm->dlm_domain_handlers);
1081 if (status)
1082 goto bail;
1083
1084 status = o2net_register_handler(DLM_MIGRATE_REQUEST_MSG, dlm->key,
1085 sizeof(struct dlm_migrate_request),
1086 dlm_migrate_request_handler,
1087 dlm, &dlm->dlm_domain_handlers);
1088 if (status)
1089 goto bail;
1090
1091 status = o2net_register_handler(DLM_MIG_LOCKRES_MSG, dlm->key,
1092 DLM_MIG_LOCKRES_MAX_LEN,
1093 dlm_mig_lockres_handler,
1094 dlm, &dlm->dlm_domain_handlers);
1095 if (status)
1096 goto bail;
1097
1098 status = o2net_register_handler(DLM_MASTER_REQUERY_MSG, dlm->key,
1099 sizeof(struct dlm_master_requery),
1100 dlm_master_requery_handler,
1101 dlm, &dlm->dlm_domain_handlers);
1102 if (status)
1103 goto bail;
1104
1105 status = o2net_register_handler(DLM_LOCK_REQUEST_MSG, dlm->key,
1106 sizeof(struct dlm_lock_request),
1107 dlm_request_all_locks_handler,
1108 dlm, &dlm->dlm_domain_handlers);
1109 if (status)
1110 goto bail;
1111
1112 status = o2net_register_handler(DLM_RECO_DATA_DONE_MSG, dlm->key,
1113 sizeof(struct dlm_reco_data_done),
1114 dlm_reco_data_done_handler,
1115 dlm, &dlm->dlm_domain_handlers);
1116 if (status)
1117 goto bail;
1118
1119 status = o2net_register_handler(DLM_BEGIN_RECO_MSG, dlm->key,
1120 sizeof(struct dlm_begin_reco),
1121 dlm_begin_reco_handler,
1122 dlm, &dlm->dlm_domain_handlers);
1123 if (status)
1124 goto bail;
1125
1126 status = o2net_register_handler(DLM_FINALIZE_RECO_MSG, dlm->key,
1127 sizeof(struct dlm_finalize_reco),
1128 dlm_finalize_reco_handler,
1129 dlm, &dlm->dlm_domain_handlers);
1130 if (status)
1131 goto bail;
1132
1133 bail:
1134 if (status)
1135 dlm_unregister_domain_handlers(dlm);
1136
1137 return status;
1138 }
1139
1140 static int dlm_join_domain(struct dlm_ctxt *dlm)
1141 {
1142 int status;
1143
1144 BUG_ON(!dlm);
1145
1146 mlog(0, "Join domain %s\n", dlm->name);
1147
1148 status = dlm_register_domain_handlers(dlm);
1149 if (status) {
1150 mlog_errno(status);
1151 goto bail;
1152 }
1153
1154 status = dlm_launch_thread(dlm);
1155 if (status < 0) {
1156 mlog_errno(status);
1157 goto bail;
1158 }
1159
1160 status = dlm_launch_recovery_thread(dlm);
1161 if (status < 0) {
1162 mlog_errno(status);
1163 goto bail;
1164 }
1165
1166 dlm->dlm_worker = create_singlethread_workqueue("dlm_wq");
1167 if (!dlm->dlm_worker) {
1168 status = -ENOMEM;
1169 mlog_errno(status);
1170 goto bail;
1171 }
1172
1173 do {
1174 unsigned int backoff;
1175 status = dlm_try_to_join_domain(dlm);
1176
1177 /* If we're racing another node to the join, then we
1178 * need to back off temporarily and let them
1179 * complete. */
1180 if (status == -EAGAIN) {
1181 if (signal_pending(current)) {
1182 status = -ERESTARTSYS;
1183 goto bail;
1184 }
1185
1186 /*
1187 * <chip> After you!
1188 * <dale> No, after you!
1189 * <chip> I insist!
1190 * <dale> But you first!
1191 * ...
1192 */
1193 backoff = (unsigned int)(jiffies & 0x3);
1194 backoff *= DLM_DOMAIN_BACKOFF_MS;
1195 mlog(0, "backoff %d\n", backoff);
1196 msleep(backoff);
1197 }
1198 } while (status == -EAGAIN);
1199
1200 if (status < 0) {
1201 mlog_errno(status);
1202 goto bail;
1203 }
1204
1205 status = 0;
1206 bail:
1207 wake_up(&dlm_domain_events);
1208
1209 if (status) {
1210 dlm_unregister_domain_handlers(dlm);
1211 dlm_complete_thread(dlm);
1212 dlm_complete_recovery_thread(dlm);
1213 dlm_destroy_dlm_worker(dlm);
1214 }
1215
1216 return status;
1217 }
1218
1219 static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain,
1220 u32 key)
1221 {
1222 int i;
1223 struct dlm_ctxt *dlm = NULL;
1224
1225 dlm = kcalloc(1, sizeof(*dlm), GFP_KERNEL);
1226 if (!dlm) {
1227 mlog_errno(-ENOMEM);
1228 goto leave;
1229 }
1230
1231 dlm->name = kmalloc(strlen(domain) + 1, GFP_KERNEL);
1232 if (dlm->name == NULL) {
1233 mlog_errno(-ENOMEM);
1234 kfree(dlm);
1235 dlm = NULL;
1236 goto leave;
1237 }
1238
1239 dlm->lockres_hash = (struct hlist_head **)dlm_alloc_pagevec(DLM_HASH_PAGES);
1240 if (!dlm->lockres_hash) {
1241 mlog_errno(-ENOMEM);
1242 kfree(dlm->name);
1243 kfree(dlm);
1244 dlm = NULL;
1245 goto leave;
1246 }
1247
1248 for (i = 0; i < DLM_HASH_BUCKETS; i++)
1249 INIT_HLIST_HEAD(dlm_lockres_hash(dlm, i));
1250
1251 strcpy(dlm->name, domain);
1252 dlm->key = key;
1253 dlm->node_num = o2nm_this_node();
1254
1255 spin_lock_init(&dlm->spinlock);
1256 spin_lock_init(&dlm->master_lock);
1257 spin_lock_init(&dlm->ast_lock);
1258 INIT_LIST_HEAD(&dlm->list);
1259 INIT_LIST_HEAD(&dlm->dirty_list);
1260 INIT_LIST_HEAD(&dlm->reco.resources);
1261 INIT_LIST_HEAD(&dlm->reco.received);
1262 INIT_LIST_HEAD(&dlm->reco.node_data);
1263 INIT_LIST_HEAD(&dlm->purge_list);
1264 INIT_LIST_HEAD(&dlm->dlm_domain_handlers);
1265 dlm->reco.state = 0;
1266
1267 INIT_LIST_HEAD(&dlm->pending_asts);
1268 INIT_LIST_HEAD(&dlm->pending_basts);
1269
1270 mlog(0, "dlm->recovery_map=%p, &(dlm->recovery_map[0])=%p\n",
1271 dlm->recovery_map, &(dlm->recovery_map[0]));
1272
1273 memset(dlm->recovery_map, 0, sizeof(dlm->recovery_map));
1274 memset(dlm->live_nodes_map, 0, sizeof(dlm->live_nodes_map));
1275 memset(dlm->domain_map, 0, sizeof(dlm->domain_map));
1276
1277 dlm->dlm_thread_task = NULL;
1278 dlm->dlm_reco_thread_task = NULL;
1279 dlm->dlm_worker = NULL;
1280 init_waitqueue_head(&dlm->dlm_thread_wq);
1281 init_waitqueue_head(&dlm->dlm_reco_thread_wq);
1282 init_waitqueue_head(&dlm->reco.event);
1283 init_waitqueue_head(&dlm->ast_wq);
1284 init_waitqueue_head(&dlm->migration_wq);
1285 INIT_LIST_HEAD(&dlm->master_list);
1286 INIT_LIST_HEAD(&dlm->mle_hb_events);
1287
1288 dlm->joining_node = DLM_LOCK_RES_OWNER_UNKNOWN;
1289 init_waitqueue_head(&dlm->dlm_join_events);
1290
1291 dlm->reco.new_master = O2NM_INVALID_NODE_NUM;
1292 dlm->reco.dead_node = O2NM_INVALID_NODE_NUM;
1293 atomic_set(&dlm->local_resources, 0);
1294 atomic_set(&dlm->remote_resources, 0);
1295 atomic_set(&dlm->unknown_resources, 0);
1296
1297 spin_lock_init(&dlm->work_lock);
1298 INIT_LIST_HEAD(&dlm->work_list);
1299 INIT_WORK(&dlm->dispatched_work, dlm_dispatch_work, dlm);
1300
1301 kref_init(&dlm->dlm_refs);
1302 dlm->dlm_state = DLM_CTXT_NEW;
1303
1304 INIT_LIST_HEAD(&dlm->dlm_eviction_callbacks);
1305
1306 mlog(0, "context init: refcount %u\n",
1307 atomic_read(&dlm->dlm_refs.refcount));
1308
1309 leave:
1310 return dlm;
1311 }
1312
1313 /*
1314 * dlm_register_domain: one-time setup per "domain"
1315 */
1316 struct dlm_ctxt * dlm_register_domain(const char *domain,
1317 u32 key)
1318 {
1319 int ret;
1320 struct dlm_ctxt *dlm = NULL;
1321 struct dlm_ctxt *new_ctxt = NULL;
1322
1323 if (strlen(domain) > O2NM_MAX_NAME_LEN) {
1324 ret = -ENAMETOOLONG;
1325 mlog(ML_ERROR, "domain name length too long\n");
1326 goto leave;
1327 }
1328
1329 if (!o2hb_check_local_node_heartbeating()) {
1330 mlog(ML_ERROR, "the local node has not been configured, or is "
1331 "not heartbeating\n");
1332 ret = -EPROTO;
1333 goto leave;
1334 }
1335
1336 mlog(0, "register called for domain \"%s\"\n", domain);
1337
1338 retry:
1339 dlm = NULL;
1340 if (signal_pending(current)) {
1341 ret = -ERESTARTSYS;
1342 mlog_errno(ret);
1343 goto leave;
1344 }
1345
1346 spin_lock(&dlm_domain_lock);
1347
1348 dlm = __dlm_lookup_domain(domain);
1349 if (dlm) {
1350 if (dlm->dlm_state != DLM_CTXT_JOINED) {
1351 spin_unlock(&dlm_domain_lock);
1352
1353 mlog(0, "This ctxt is not joined yet!\n");
1354 wait_event_interruptible(dlm_domain_events,
1355 dlm_wait_on_domain_helper(
1356 domain));
1357 goto retry;
1358 }
1359
1360 __dlm_get(dlm);
1361 dlm->num_joins++;
1362
1363 spin_unlock(&dlm_domain_lock);
1364
1365 ret = 0;
1366 goto leave;
1367 }
1368
1369 /* doesn't exist */
1370 if (!new_ctxt) {
1371 spin_unlock(&dlm_domain_lock);
1372
1373 new_ctxt = dlm_alloc_ctxt(domain, key);
1374 if (new_ctxt)
1375 goto retry;
1376
1377 ret = -ENOMEM;
1378 mlog_errno(ret);
1379 goto leave;
1380 }
1381
1382 /* a little variable switch-a-roo here... */
1383 dlm = new_ctxt;
1384 new_ctxt = NULL;
1385
1386 /* add the new domain */
1387 list_add_tail(&dlm->list, &dlm_domains);
1388 spin_unlock(&dlm_domain_lock);
1389
1390 ret = dlm_join_domain(dlm);
1391 if (ret) {
1392 mlog_errno(ret);
1393 dlm_put(dlm);
1394 goto leave;
1395 }
1396
1397 ret = 0;
1398 leave:
1399 if (new_ctxt)
1400 dlm_free_ctxt_mem(new_ctxt);
1401
1402 if (ret < 0)
1403 dlm = ERR_PTR(ret);
1404
1405 return dlm;
1406 }
1407 EXPORT_SYMBOL_GPL(dlm_register_domain);
1408
1409 static LIST_HEAD(dlm_join_handlers);
1410
1411 static void dlm_unregister_net_handlers(void)
1412 {
1413 o2net_unregister_handler_list(&dlm_join_handlers);
1414 }
1415
1416 static int dlm_register_net_handlers(void)
1417 {
1418 int status = 0;
1419
1420 status = o2net_register_handler(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY,
1421 sizeof(struct dlm_query_join_request),
1422 dlm_query_join_handler,
1423 NULL, &dlm_join_handlers);
1424 if (status)
1425 goto bail;
1426
1427 status = o2net_register_handler(DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY,
1428 sizeof(struct dlm_assert_joined),
1429 dlm_assert_joined_handler,
1430 NULL, &dlm_join_handlers);
1431 if (status)
1432 goto bail;
1433
1434 status = o2net_register_handler(DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY,
1435 sizeof(struct dlm_cancel_join),
1436 dlm_cancel_join_handler,
1437 NULL, &dlm_join_handlers);
1438
1439 bail:
1440 if (status < 0)
1441 dlm_unregister_net_handlers();
1442
1443 return status;
1444 }
1445
1446 /* Domain eviction callback handling.
1447 *
1448 * The file system requires notification of node death *before* the
1449 * dlm completes it's recovery work, otherwise it may be able to
1450 * acquire locks on resources requiring recovery. Since the dlm can
1451 * evict a node from it's domain *before* heartbeat fires, a similar
1452 * mechanism is required. */
1453
1454 /* Eviction is not expected to happen often, so a per-domain lock is
1455 * not necessary. Eviction callbacks are allowed to sleep for short
1456 * periods of time. */
1457 static DECLARE_RWSEM(dlm_callback_sem);
1458
1459 void dlm_fire_domain_eviction_callbacks(struct dlm_ctxt *dlm,
1460 int node_num)
1461 {
1462 struct list_head *iter;
1463 struct dlm_eviction_cb *cb;
1464
1465 down_read(&dlm_callback_sem);
1466 list_for_each(iter, &dlm->dlm_eviction_callbacks) {
1467 cb = list_entry(iter, struct dlm_eviction_cb, ec_item);
1468
1469 cb->ec_func(node_num, cb->ec_data);
1470 }
1471 up_read(&dlm_callback_sem);
1472 }
1473
1474 void dlm_setup_eviction_cb(struct dlm_eviction_cb *cb,
1475 dlm_eviction_func *f,
1476 void *data)
1477 {
1478 INIT_LIST_HEAD(&cb->ec_item);
1479 cb->ec_func = f;
1480 cb->ec_data = data;
1481 }
1482 EXPORT_SYMBOL_GPL(dlm_setup_eviction_cb);
1483
1484 void dlm_register_eviction_cb(struct dlm_ctxt *dlm,
1485 struct dlm_eviction_cb *cb)
1486 {
1487 down_write(&dlm_callback_sem);
1488 list_add_tail(&cb->ec_item, &dlm->dlm_eviction_callbacks);
1489 up_write(&dlm_callback_sem);
1490 }
1491 EXPORT_SYMBOL_GPL(dlm_register_eviction_cb);
1492
1493 void dlm_unregister_eviction_cb(struct dlm_eviction_cb *cb)
1494 {
1495 down_write(&dlm_callback_sem);
1496 list_del_init(&cb->ec_item);
1497 up_write(&dlm_callback_sem);
1498 }
1499 EXPORT_SYMBOL_GPL(dlm_unregister_eviction_cb);
1500
1501 static int __init dlm_init(void)
1502 {
1503 int status;
1504
1505 dlm_print_version();
1506
1507 status = dlm_init_mle_cache();
1508 if (status)
1509 return -1;
1510
1511 status = dlm_register_net_handlers();
1512 if (status) {
1513 dlm_destroy_mle_cache();
1514 return -1;
1515 }
1516
1517 return 0;
1518 }
1519
1520 static void __exit dlm_exit (void)
1521 {
1522 dlm_unregister_net_handlers();
1523 dlm_destroy_mle_cache();
1524 }
1525
1526 MODULE_AUTHOR("Oracle");
1527 MODULE_LICENSE("GPL");
1528
1529 module_init(dlm_init);
1530 module_exit(dlm_exit);
WRT350N Kernel Patches