1 /* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
6 * defines domain join / leave apis
8 * Copyright (C) 2004 Oracle. All rights reserved.
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.
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.
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.
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>
37 #include "cluster/heartbeat.h"
38 #include "cluster/nodemanager.h"
39 #include "cluster/tcp.h"
42 #include "dlmcommon.h"
45 #include "dlmdomain.h"
49 #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_DOMAIN)
50 #include "cluster/masklog.h"
54 * spinlock lock ordering: if multiple locks are needed, obey this ordering:
56 * struct dlm_ctxt->spinlock
57 * struct dlm_lock_resource->spinlock
58 * struct dlm_ctxt->master_lock
59 * struct dlm_ctxt->ast_lock
60 * dlm_master_list_entry->spinlock
65 spinlock_t dlm_domain_lock = SPIN_LOCK_UNLOCKED;
66 LIST_HEAD(dlm_domains);
67 static DECLARE_WAIT_QUEUE_HEAD(dlm_domain_events);
69 #define DLM_DOMAIN_BACKOFF_MS 200
71 static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data);
72 static int dlm_assert_joined_handler(struct o2net_msg *msg, u32 len, void *data);
73 static int dlm_cancel_join_handler(struct o2net_msg *msg, u32 len, void *data);
74 static int dlm_exit_domain_handler(struct o2net_msg *msg, u32 len, void *data);
76 static void dlm_unregister_domain_handlers(struct dlm_ctxt *dlm);
78 void __dlm_unhash_lockres(struct dlm_lock_resource *lockres)
80 hlist_del_init(&lockres->hash_node);
81 dlm_lockres_put(lockres);
84 void __dlm_insert_lockres(struct dlm_ctxt *dlm,
85 struct dlm_lock_resource *res)
87 struct hlist_head *bucket;
90 assert_spin_locked(&dlm->spinlock);
93 bucket = &(dlm->lockres_hash[q->hash % DLM_HASH_BUCKETS]);
95 /* get a reference for our hashtable */
98 hlist_add_head(&res->hash_node, bucket);
101 struct dlm_lock_resource * __dlm_lookup_lockres(struct dlm_ctxt *dlm,
106 struct hlist_node *iter;
107 struct dlm_lock_resource *tmpres=NULL;
108 struct hlist_head *bucket;
110 mlog_entry("%.*s\n", len, name);
112 assert_spin_locked(&dlm->spinlock);
114 bucket = &(dlm->lockres_hash[hash % DLM_HASH_BUCKETS]);
116 /* check for pre-existing lock */
117 hlist_for_each(iter, bucket) {
118 tmpres = hlist_entry(iter, struct dlm_lock_resource, hash_node);
119 if (tmpres->lockname.len == len &&
120 memcmp(tmpres->lockname.name, name, len) == 0) {
121 dlm_lockres_get(tmpres);
130 struct dlm_lock_resource * dlm_lookup_lockres(struct dlm_ctxt *dlm,
134 struct dlm_lock_resource *res;
135 unsigned int hash = dlm_lockid_hash(name, len);
137 spin_lock(&dlm->spinlock);
138 res = __dlm_lookup_lockres(dlm, name, len, hash);
139 spin_unlock(&dlm->spinlock);
143 static struct dlm_ctxt * __dlm_lookup_domain_full(const char *domain, int len)
145 struct dlm_ctxt *tmp = NULL;
146 struct list_head *iter;
148 assert_spin_locked(&dlm_domain_lock);
150 /* tmp->name here is always NULL terminated,
151 * but domain may not be! */
152 list_for_each(iter, &dlm_domains) {
153 tmp = list_entry (iter, struct dlm_ctxt, list);
154 if (strlen(tmp->name) == len &&
155 memcmp(tmp->name, domain, len)==0)
163 /* For null terminated domain strings ONLY */
164 static struct dlm_ctxt * __dlm_lookup_domain(const char *domain)
166 assert_spin_locked(&dlm_domain_lock);
168 return __dlm_lookup_domain_full(domain, strlen(domain));
172 /* returns true on one of two conditions:
173 * 1) the domain does not exist
174 * 2) the domain exists and it's state is "joined" */
175 static int dlm_wait_on_domain_helper(const char *domain)
178 struct dlm_ctxt *tmp = NULL;
180 spin_lock(&dlm_domain_lock);
182 tmp = __dlm_lookup_domain(domain);
185 else if (tmp->dlm_state == DLM_CTXT_JOINED)
188 spin_unlock(&dlm_domain_lock);
192 static void dlm_free_ctxt_mem(struct dlm_ctxt *dlm)
194 if (dlm->lockres_hash)
195 free_page((unsigned long) dlm->lockres_hash);
203 /* A little strange - this function will be called while holding
204 * dlm_domain_lock and is expected to be holding it on the way out. We
205 * will however drop and reacquire it multiple times */
206 static void dlm_ctxt_release(struct kref *kref)
208 struct dlm_ctxt *dlm;
210 dlm = container_of(kref, struct dlm_ctxt, dlm_refs);
212 BUG_ON(dlm->num_joins);
213 BUG_ON(dlm->dlm_state == DLM_CTXT_JOINED);
215 /* we may still be in the list if we hit an error during join. */
216 list_del_init(&dlm->list);
218 spin_unlock(&dlm_domain_lock);
220 mlog(0, "freeing memory from domain %s\n", dlm->name);
222 wake_up(&dlm_domain_events);
224 dlm_free_ctxt_mem(dlm);
226 spin_lock(&dlm_domain_lock);
229 void dlm_put(struct dlm_ctxt *dlm)
231 spin_lock(&dlm_domain_lock);
232 kref_put(&dlm->dlm_refs, dlm_ctxt_release);
233 spin_unlock(&dlm_domain_lock);
236 static void __dlm_get(struct dlm_ctxt *dlm)
238 kref_get(&dlm->dlm_refs);
241 /* given a questionable reference to a dlm object, gets a reference if
242 * it can find it in the list, otherwise returns NULL in which case
243 * you shouldn't trust your pointer. */
244 struct dlm_ctxt *dlm_grab(struct dlm_ctxt *dlm)
246 struct list_head *iter;
247 struct dlm_ctxt *target = NULL;
249 spin_lock(&dlm_domain_lock);
251 list_for_each(iter, &dlm_domains) {
252 target = list_entry (iter, struct dlm_ctxt, list);
262 spin_unlock(&dlm_domain_lock);
267 int dlm_domain_fully_joined(struct dlm_ctxt *dlm)
271 spin_lock(&dlm_domain_lock);
272 ret = (dlm->dlm_state == DLM_CTXT_JOINED) ||
273 (dlm->dlm_state == DLM_CTXT_IN_SHUTDOWN);
274 spin_unlock(&dlm_domain_lock);
279 static void dlm_complete_dlm_shutdown(struct dlm_ctxt *dlm)
281 dlm_unregister_domain_handlers(dlm);
282 dlm_complete_thread(dlm);
283 dlm_complete_recovery_thread(dlm);
285 /* We've left the domain. Now we can take ourselves out of the
286 * list and allow the kref stuff to help us free the
288 spin_lock(&dlm_domain_lock);
289 list_del_init(&dlm->list);
290 spin_unlock(&dlm_domain_lock);
292 /* Wake up anyone waiting for us to remove this domain */
293 wake_up(&dlm_domain_events);
296 static void dlm_migrate_all_locks(struct dlm_ctxt *dlm)
299 struct dlm_lock_resource *res;
301 mlog(0, "Migrating locks from domain %s\n", dlm->name);
303 spin_lock(&dlm->spinlock);
304 for (i = 0; i < DLM_HASH_BUCKETS; i++) {
305 while (!hlist_empty(&dlm->lockres_hash[i])) {
306 res = hlist_entry(dlm->lockres_hash[i].first,
307 struct dlm_lock_resource, hash_node);
308 /* need reference when manually grabbing lockres */
309 dlm_lockres_get(res);
310 /* this should unhash the lockres
311 * and exit with dlm->spinlock */
312 mlog(0, "purging res=%p\n", res);
313 if (dlm_lockres_is_dirty(dlm, res)) {
314 /* HACK! this should absolutely go.
315 * need to figure out why some empty
316 * lockreses are still marked dirty */
317 mlog(ML_ERROR, "lockres %.*s dirty!\n",
318 res->lockname.len, res->lockname.name);
320 spin_unlock(&dlm->spinlock);
321 dlm_kick_thread(dlm, res);
322 wait_event(dlm->ast_wq, !dlm_lockres_is_dirty(dlm, res));
323 dlm_lockres_put(res);
326 dlm_purge_lockres(dlm, res);
327 dlm_lockres_put(res);
330 spin_unlock(&dlm->spinlock);
332 mlog(0, "DONE Migrating locks from domain %s\n", dlm->name);
335 static int dlm_no_joining_node(struct dlm_ctxt *dlm)
339 spin_lock(&dlm->spinlock);
340 ret = dlm->joining_node == DLM_LOCK_RES_OWNER_UNKNOWN;
341 spin_unlock(&dlm->spinlock);
346 static void dlm_mark_domain_leaving(struct dlm_ctxt *dlm)
348 /* Yikes, a double spinlock! I need domain_lock for the dlm
349 * state and the dlm spinlock for join state... Sorry! */
351 spin_lock(&dlm_domain_lock);
352 spin_lock(&dlm->spinlock);
354 if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) {
355 mlog(0, "Node %d is joining, we wait on it.\n",
357 spin_unlock(&dlm->spinlock);
358 spin_unlock(&dlm_domain_lock);
360 wait_event(dlm->dlm_join_events, dlm_no_joining_node(dlm));
364 dlm->dlm_state = DLM_CTXT_LEAVING;
365 spin_unlock(&dlm->spinlock);
366 spin_unlock(&dlm_domain_lock);
369 static void __dlm_print_nodes(struct dlm_ctxt *dlm)
373 assert_spin_locked(&dlm->spinlock);
375 mlog(ML_NOTICE, "Nodes in my domain (\"%s\"):\n", dlm->name);
377 while ((node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES,
378 node + 1)) < O2NM_MAX_NODES) {
379 mlog(ML_NOTICE, " node %d\n", node);
383 static int dlm_exit_domain_handler(struct o2net_msg *msg, u32 len, void *data)
385 struct dlm_ctxt *dlm = data;
387 struct dlm_exit_domain *exit_msg = (struct dlm_exit_domain *) msg->buf;
389 mlog_entry("%p %u %p", msg, len, data);
394 node = exit_msg->node_idx;
396 mlog(0, "Node %u leaves domain %s\n", node, dlm->name);
398 spin_lock(&dlm->spinlock);
399 clear_bit(node, dlm->domain_map);
400 __dlm_print_nodes(dlm);
402 /* notify anything attached to the heartbeat events */
403 dlm_hb_event_notify_attached(dlm, node, 0);
405 spin_unlock(&dlm->spinlock);
412 static int dlm_send_one_domain_exit(struct dlm_ctxt *dlm,
416 struct dlm_exit_domain leave_msg;
418 mlog(0, "Asking node %u if we can leave the domain %s me = %u\n",
419 node, dlm->name, dlm->node_num);
421 memset(&leave_msg, 0, sizeof(leave_msg));
422 leave_msg.node_idx = dlm->node_num;
424 status = o2net_send_message(DLM_EXIT_DOMAIN_MSG, dlm->key,
425 &leave_msg, sizeof(leave_msg), node,
428 mlog(0, "status return %d from o2net_send_message\n", status);
434 static void dlm_leave_domain(struct dlm_ctxt *dlm)
436 int node, clear_node, status;
438 /* At this point we've migrated away all our locks and won't
439 * accept mastership of new ones. The dlm is responsible for
440 * almost nothing now. We make sure not to confuse any joining
441 * nodes and then commence shutdown procedure. */
443 spin_lock(&dlm->spinlock);
444 /* Clear ourselves from the domain map */
445 clear_bit(dlm->node_num, dlm->domain_map);
446 while ((node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES,
447 0)) < O2NM_MAX_NODES) {
448 /* Drop the dlm spinlock. This is safe wrt the domain_map.
449 * -nodes cannot be added now as the
450 * query_join_handlers knows to respond with OK_NO_MAP
451 * -we catch the right network errors if a node is
452 * removed from the map while we're sending him the
454 spin_unlock(&dlm->spinlock);
458 status = dlm_send_one_domain_exit(dlm, node);
460 status != -ENOPROTOOPT &&
461 status != -ENOTCONN) {
462 mlog(ML_NOTICE, "Error %d sending domain exit message "
463 "to node %d\n", status, node);
465 /* Not sure what to do here but lets sleep for
466 * a bit in case this was a transient
468 msleep(DLM_DOMAIN_BACKOFF_MS);
472 spin_lock(&dlm->spinlock);
473 /* If we're not clearing the node bit then we intend
474 * to loop back around to try again. */
476 clear_bit(node, dlm->domain_map);
478 spin_unlock(&dlm->spinlock);
481 int dlm_joined(struct dlm_ctxt *dlm)
485 spin_lock(&dlm_domain_lock);
487 if (dlm->dlm_state == DLM_CTXT_JOINED)
490 spin_unlock(&dlm_domain_lock);
495 int dlm_shutting_down(struct dlm_ctxt *dlm)
499 spin_lock(&dlm_domain_lock);
501 if (dlm->dlm_state == DLM_CTXT_IN_SHUTDOWN)
504 spin_unlock(&dlm_domain_lock);
509 void dlm_unregister_domain(struct dlm_ctxt *dlm)
513 spin_lock(&dlm_domain_lock);
514 BUG_ON(dlm->dlm_state != DLM_CTXT_JOINED);
515 BUG_ON(!dlm->num_joins);
518 if (!dlm->num_joins) {
519 /* We mark it "in shutdown" now so new register
520 * requests wait until we've completely left the
521 * domain. Don't use DLM_CTXT_LEAVING yet as we still
522 * want new domain joins to communicate with us at
523 * least until we've completed migration of our
525 dlm->dlm_state = DLM_CTXT_IN_SHUTDOWN;
528 spin_unlock(&dlm_domain_lock);
531 mlog(0, "shutting down domain %s\n", dlm->name);
533 /* We changed dlm state, notify the thread */
534 dlm_kick_thread(dlm, NULL);
536 dlm_migrate_all_locks(dlm);
537 dlm_mark_domain_leaving(dlm);
538 dlm_leave_domain(dlm);
539 dlm_complete_dlm_shutdown(dlm);
543 EXPORT_SYMBOL_GPL(dlm_unregister_domain);
545 static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data)
547 struct dlm_query_join_request *query;
548 enum dlm_query_join_response response;
549 struct dlm_ctxt *dlm = NULL;
551 query = (struct dlm_query_join_request *) msg->buf;
553 mlog(0, "node %u wants to join domain %s\n", query->node_idx,
557 * If heartbeat doesn't consider the node live, tell it
558 * to back off and try again. This gives heartbeat a chance
561 if (!o2hb_check_node_heartbeating(query->node_idx)) {
562 mlog(0, "node %u is not in our live map yet\n",
565 response = JOIN_DISALLOW;
569 response = JOIN_OK_NO_MAP;
571 spin_lock(&dlm_domain_lock);
572 dlm = __dlm_lookup_domain_full(query->domain, query->name_len);
573 /* Once the dlm ctxt is marked as leaving then we don't want
574 * to be put in someone's domain map.
575 * Also, explicitly disallow joining at certain troublesome
576 * times (ie. during recovery). */
577 if (dlm && dlm->dlm_state != DLM_CTXT_LEAVING) {
578 int bit = query->node_idx;
579 spin_lock(&dlm->spinlock);
581 if (dlm->dlm_state == DLM_CTXT_NEW &&
582 dlm->joining_node == DLM_LOCK_RES_OWNER_UNKNOWN) {
583 /*If this is a brand new context and we
584 * haven't started our join process yet, then
585 * the other node won the race. */
586 response = JOIN_OK_NO_MAP;
587 } else if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) {
588 /* Disallow parallel joins. */
589 response = JOIN_DISALLOW;
590 } else if (dlm->reco.state & DLM_RECO_STATE_ACTIVE) {
591 mlog(ML_NOTICE, "node %u trying to join, but recovery "
592 "is ongoing.\n", bit);
593 response = JOIN_DISALLOW;
594 } else if (test_bit(bit, dlm->recovery_map)) {
595 mlog(ML_NOTICE, "node %u trying to join, but it "
596 "still needs recovery.\n", bit);
597 response = JOIN_DISALLOW;
598 } else if (test_bit(bit, dlm->domain_map)) {
599 mlog(ML_NOTICE, "node %u trying to join, but it "
600 "is still in the domain! needs recovery?\n",
602 response = JOIN_DISALLOW;
604 /* Alright we're fully a part of this domain
605 * so we keep some state as to who's joining
606 * and indicate to him that needs to be fixed
609 __dlm_set_joining_node(dlm, query->node_idx);
612 spin_unlock(&dlm->spinlock);
614 spin_unlock(&dlm_domain_lock);
617 mlog(0, "We respond with %u\n", response);
622 static int dlm_assert_joined_handler(struct o2net_msg *msg, u32 len, void *data)
624 struct dlm_assert_joined *assert;
625 struct dlm_ctxt *dlm = NULL;
627 assert = (struct dlm_assert_joined *) msg->buf;
629 mlog(0, "node %u asserts join on domain %s\n", assert->node_idx,
632 spin_lock(&dlm_domain_lock);
633 dlm = __dlm_lookup_domain_full(assert->domain, assert->name_len);
634 /* XXX should we consider no dlm ctxt an error? */
636 spin_lock(&dlm->spinlock);
638 /* Alright, this node has officially joined our
639 * domain. Set him in the map and clean up our
640 * leftover join state. */
641 BUG_ON(dlm->joining_node != assert->node_idx);
642 set_bit(assert->node_idx, dlm->domain_map);
643 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
645 __dlm_print_nodes(dlm);
647 /* notify anything attached to the heartbeat events */
648 dlm_hb_event_notify_attached(dlm, assert->node_idx, 1);
650 spin_unlock(&dlm->spinlock);
652 spin_unlock(&dlm_domain_lock);
657 static int dlm_cancel_join_handler(struct o2net_msg *msg, u32 len, void *data)
659 struct dlm_cancel_join *cancel;
660 struct dlm_ctxt *dlm = NULL;
662 cancel = (struct dlm_cancel_join *) msg->buf;
664 mlog(0, "node %u cancels join on domain %s\n", cancel->node_idx,
667 spin_lock(&dlm_domain_lock);
668 dlm = __dlm_lookup_domain_full(cancel->domain, cancel->name_len);
671 spin_lock(&dlm->spinlock);
673 /* Yikes, this guy wants to cancel his join. No
674 * problem, we simply cleanup our join state. */
675 BUG_ON(dlm->joining_node != cancel->node_idx);
676 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
678 spin_unlock(&dlm->spinlock);
680 spin_unlock(&dlm_domain_lock);
685 static int dlm_send_one_join_cancel(struct dlm_ctxt *dlm,
689 struct dlm_cancel_join cancel_msg;
691 memset(&cancel_msg, 0, sizeof(cancel_msg));
692 cancel_msg.node_idx = dlm->node_num;
693 cancel_msg.name_len = strlen(dlm->name);
694 memcpy(cancel_msg.domain, dlm->name, cancel_msg.name_len);
696 status = o2net_send_message(DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY,
697 &cancel_msg, sizeof(cancel_msg), node,
708 /* map_size should be in bytes. */
709 static int dlm_send_join_cancels(struct dlm_ctxt *dlm,
710 unsigned long *node_map,
711 unsigned int map_size)
716 if (map_size != (BITS_TO_LONGS(O2NM_MAX_NODES) *
717 sizeof(unsigned long))) {
719 "map_size %u != BITS_TO_LONGS(O2NM_MAX_NODES) %u\n",
720 map_size, BITS_TO_LONGS(O2NM_MAX_NODES));
726 while ((node = find_next_bit(node_map, O2NM_MAX_NODES,
727 node + 1)) < O2NM_MAX_NODES) {
728 if (node == dlm->node_num)
731 tmpstat = dlm_send_one_join_cancel(dlm, node);
733 mlog(ML_ERROR, "Error return %d cancelling join on "
734 "node %d\n", tmpstat, node);
745 static int dlm_request_join(struct dlm_ctxt *dlm,
747 enum dlm_query_join_response *response)
750 struct dlm_query_join_request join_msg;
752 mlog(0, "querying node %d\n", node);
754 memset(&join_msg, 0, sizeof(join_msg));
755 join_msg.node_idx = dlm->node_num;
756 join_msg.name_len = strlen(dlm->name);
757 memcpy(join_msg.domain, dlm->name, join_msg.name_len);
759 status = o2net_send_message(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY, &join_msg,
760 sizeof(join_msg), node, &retval);
761 if (status < 0 && status != -ENOPROTOOPT) {
766 /* -ENOPROTOOPT from the net code means the other side isn't
767 listening for our message type -- that's fine, it means
768 his dlm isn't up, so we can consider him a 'yes' but not
769 joined into the domain. */
770 if (status == -ENOPROTOOPT) {
772 *response = JOIN_OK_NO_MAP;
773 } else if (retval == JOIN_DISALLOW ||
775 retval == JOIN_OK_NO_MAP) {
779 mlog(ML_ERROR, "invalid response %d from node %u\n", retval,
783 mlog(0, "status %d, node %d response is %d\n", status, node,
790 static int dlm_send_one_join_assert(struct dlm_ctxt *dlm,
794 struct dlm_assert_joined assert_msg;
796 mlog(0, "Sending join assert to node %u\n", node);
798 memset(&assert_msg, 0, sizeof(assert_msg));
799 assert_msg.node_idx = dlm->node_num;
800 assert_msg.name_len = strlen(dlm->name);
801 memcpy(assert_msg.domain, dlm->name, assert_msg.name_len);
803 status = o2net_send_message(DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY,
804 &assert_msg, sizeof(assert_msg), node,
812 static void dlm_send_join_asserts(struct dlm_ctxt *dlm,
813 unsigned long *node_map)
815 int status, node, live;
819 while ((node = find_next_bit(node_map, O2NM_MAX_NODES,
820 node + 1)) < O2NM_MAX_NODES) {
821 if (node == dlm->node_num)
825 /* It is very important that this message be
826 * received so we spin until either the node
827 * has died or it gets the message. */
828 status = dlm_send_one_join_assert(dlm, node);
830 spin_lock(&dlm->spinlock);
831 live = test_bit(node, dlm->live_nodes_map);
832 spin_unlock(&dlm->spinlock);
835 mlog(ML_ERROR, "Error return %d asserting "
836 "join on node %d\n", status, node);
838 /* give us some time between errors... */
840 msleep(DLM_DOMAIN_BACKOFF_MS);
842 } while (status && live);
846 struct domain_join_ctxt {
847 unsigned long live_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
848 unsigned long yes_resp_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
851 static int dlm_should_restart_join(struct dlm_ctxt *dlm,
852 struct domain_join_ctxt *ctxt,
853 enum dlm_query_join_response response)
857 if (response == JOIN_DISALLOW) {
858 mlog(0, "Latest response of disallow -- should restart\n");
862 spin_lock(&dlm->spinlock);
863 /* For now, we restart the process if the node maps have
865 ret = memcmp(ctxt->live_map, dlm->live_nodes_map,
866 sizeof(dlm->live_nodes_map));
867 spin_unlock(&dlm->spinlock);
870 mlog(0, "Node maps changed -- should restart\n");
875 static int dlm_try_to_join_domain(struct dlm_ctxt *dlm)
877 int status = 0, tmpstat, node;
878 struct domain_join_ctxt *ctxt;
879 enum dlm_query_join_response response;
881 mlog_entry("%p", dlm);
883 ctxt = kcalloc(1, sizeof(*ctxt), GFP_KERNEL);
890 /* group sem locking should work for us here -- we're already
891 * registered for heartbeat events so filling this should be
892 * atomic wrt getting those handlers called. */
893 o2hb_fill_node_map(dlm->live_nodes_map, sizeof(dlm->live_nodes_map));
895 spin_lock(&dlm->spinlock);
896 memcpy(ctxt->live_map, dlm->live_nodes_map, sizeof(ctxt->live_map));
898 __dlm_set_joining_node(dlm, dlm->node_num);
900 spin_unlock(&dlm->spinlock);
903 while ((node = find_next_bit(ctxt->live_map, O2NM_MAX_NODES,
904 node + 1)) < O2NM_MAX_NODES) {
905 if (node == dlm->node_num)
908 status = dlm_request_join(dlm, node, &response);
914 /* Ok, either we got a response or the node doesn't have a
916 if (response == JOIN_OK)
917 set_bit(node, ctxt->yes_resp_map);
919 if (dlm_should_restart_join(dlm, ctxt, response)) {
925 mlog(0, "Yay, done querying nodes!\n");
927 /* Yay, everyone agree's we can join the domain. My domain is
928 * comprised of all nodes who were put in the
929 * yes_resp_map. Copy that into our domain map and send a join
930 * assert message to clean up everyone elses state. */
931 spin_lock(&dlm->spinlock);
932 memcpy(dlm->domain_map, ctxt->yes_resp_map,
933 sizeof(ctxt->yes_resp_map));
934 set_bit(dlm->node_num, dlm->domain_map);
935 spin_unlock(&dlm->spinlock);
937 dlm_send_join_asserts(dlm, ctxt->yes_resp_map);
939 /* Joined state *must* be set before the joining node
940 * information, otherwise the query_join handler may read no
941 * current joiner but a state of NEW and tell joining nodes
942 * we're not in the domain. */
943 spin_lock(&dlm_domain_lock);
944 dlm->dlm_state = DLM_CTXT_JOINED;
946 spin_unlock(&dlm_domain_lock);
949 spin_lock(&dlm->spinlock);
950 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
952 __dlm_print_nodes(dlm);
953 spin_unlock(&dlm->spinlock);
956 /* Do we need to send a cancel message to any nodes? */
958 tmpstat = dlm_send_join_cancels(dlm,
960 sizeof(ctxt->yes_resp_map));
967 mlog(0, "returning %d\n", status);
971 static void dlm_unregister_domain_handlers(struct dlm_ctxt *dlm)
973 o2hb_unregister_callback(&dlm->dlm_hb_up);
974 o2hb_unregister_callback(&dlm->dlm_hb_down);
975 o2net_unregister_handler_list(&dlm->dlm_domain_handlers);
978 static int dlm_register_domain_handlers(struct dlm_ctxt *dlm)
982 mlog(0, "registering handlers.\n");
984 o2hb_setup_callback(&dlm->dlm_hb_down, O2HB_NODE_DOWN_CB,
985 dlm_hb_node_down_cb, dlm, DLM_HB_NODE_DOWN_PRI);
986 status = o2hb_register_callback(&dlm->dlm_hb_down);
990 o2hb_setup_callback(&dlm->dlm_hb_up, O2HB_NODE_UP_CB,
991 dlm_hb_node_up_cb, dlm, DLM_HB_NODE_UP_PRI);
992 status = o2hb_register_callback(&dlm->dlm_hb_up);
996 status = o2net_register_handler(DLM_MASTER_REQUEST_MSG, dlm->key,
997 sizeof(struct dlm_master_request),
998 dlm_master_request_handler,
999 dlm, &dlm->dlm_domain_handlers);
1003 status = o2net_register_handler(DLM_ASSERT_MASTER_MSG, dlm->key,
1004 sizeof(struct dlm_assert_master),
1005 dlm_assert_master_handler,
1006 dlm, &dlm->dlm_domain_handlers);
1010 status = o2net_register_handler(DLM_CREATE_LOCK_MSG, dlm->key,
1011 sizeof(struct dlm_create_lock),
1012 dlm_create_lock_handler,
1013 dlm, &dlm->dlm_domain_handlers);
1017 status = o2net_register_handler(DLM_CONVERT_LOCK_MSG, dlm->key,
1018 DLM_CONVERT_LOCK_MAX_LEN,
1019 dlm_convert_lock_handler,
1020 dlm, &dlm->dlm_domain_handlers);
1024 status = o2net_register_handler(DLM_UNLOCK_LOCK_MSG, dlm->key,
1025 DLM_UNLOCK_LOCK_MAX_LEN,
1026 dlm_unlock_lock_handler,
1027 dlm, &dlm->dlm_domain_handlers);
1031 status = o2net_register_handler(DLM_PROXY_AST_MSG, dlm->key,
1032 DLM_PROXY_AST_MAX_LEN,
1033 dlm_proxy_ast_handler,
1034 dlm, &dlm->dlm_domain_handlers);
1038 status = o2net_register_handler(DLM_EXIT_DOMAIN_MSG, dlm->key,
1039 sizeof(struct dlm_exit_domain),
1040 dlm_exit_domain_handler,
1041 dlm, &dlm->dlm_domain_handlers);
1045 status = o2net_register_handler(DLM_MIGRATE_REQUEST_MSG, dlm->key,
1046 sizeof(struct dlm_migrate_request),
1047 dlm_migrate_request_handler,
1048 dlm, &dlm->dlm_domain_handlers);
1052 status = o2net_register_handler(DLM_MIG_LOCKRES_MSG, dlm->key,
1053 DLM_MIG_LOCKRES_MAX_LEN,
1054 dlm_mig_lockres_handler,
1055 dlm, &dlm->dlm_domain_handlers);
1059 status = o2net_register_handler(DLM_MASTER_REQUERY_MSG, dlm->key,
1060 sizeof(struct dlm_master_requery),
1061 dlm_master_requery_handler,
1062 dlm, &dlm->dlm_domain_handlers);
1066 status = o2net_register_handler(DLM_LOCK_REQUEST_MSG, dlm->key,
1067 sizeof(struct dlm_lock_request),
1068 dlm_request_all_locks_handler,
1069 dlm, &dlm->dlm_domain_handlers);
1073 status = o2net_register_handler(DLM_RECO_DATA_DONE_MSG, dlm->key,
1074 sizeof(struct dlm_reco_data_done),
1075 dlm_reco_data_done_handler,
1076 dlm, &dlm->dlm_domain_handlers);
1080 status = o2net_register_handler(DLM_BEGIN_RECO_MSG, dlm->key,
1081 sizeof(struct dlm_begin_reco),
1082 dlm_begin_reco_handler,
1083 dlm, &dlm->dlm_domain_handlers);
1087 status = o2net_register_handler(DLM_FINALIZE_RECO_MSG, dlm->key,
1088 sizeof(struct dlm_finalize_reco),
1089 dlm_finalize_reco_handler,
1090 dlm, &dlm->dlm_domain_handlers);
1096 dlm_unregister_domain_handlers(dlm);
1101 static int dlm_join_domain(struct dlm_ctxt *dlm)
1107 mlog(0, "Join domain %s\n", dlm->name);
1109 status = dlm_register_domain_handlers(dlm);
1115 status = dlm_launch_thread(dlm);
1121 status = dlm_launch_recovery_thread(dlm);
1128 unsigned int backoff;
1129 status = dlm_try_to_join_domain(dlm);
1131 /* If we're racing another node to the join, then we
1132 * need to back off temporarily and let them
1134 if (status == -EAGAIN) {
1135 if (signal_pending(current)) {
1136 status = -ERESTARTSYS;
1142 * <dale> No, after you!
1144 * <dale> But you first!
1147 backoff = (unsigned int)(jiffies & 0x3);
1148 backoff *= DLM_DOMAIN_BACKOFF_MS;
1149 mlog(0, "backoff %d\n", backoff);
1152 } while (status == -EAGAIN);
1161 wake_up(&dlm_domain_events);
1164 dlm_unregister_domain_handlers(dlm);
1165 dlm_complete_thread(dlm);
1166 dlm_complete_recovery_thread(dlm);
1172 static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain,
1176 struct dlm_ctxt *dlm = NULL;
1178 dlm = kcalloc(1, sizeof(*dlm), GFP_KERNEL);
1180 mlog_errno(-ENOMEM);
1184 dlm->name = kmalloc(strlen(domain) + 1, GFP_KERNEL);
1185 if (dlm->name == NULL) {
1186 mlog_errno(-ENOMEM);
1192 dlm->lockres_hash = (struct hlist_head *) __get_free_page(GFP_KERNEL);
1193 if (!dlm->lockres_hash) {
1194 mlog_errno(-ENOMEM);
1201 for (i=0; i<DLM_HASH_BUCKETS; i++)
1202 INIT_HLIST_HEAD(&dlm->lockres_hash[i]);
1204 strcpy(dlm->name, domain);
1206 dlm->node_num = o2nm_this_node();
1208 spin_lock_init(&dlm->spinlock);
1209 spin_lock_init(&dlm->master_lock);
1210 spin_lock_init(&dlm->ast_lock);
1211 INIT_LIST_HEAD(&dlm->list);
1212 INIT_LIST_HEAD(&dlm->dirty_list);
1213 INIT_LIST_HEAD(&dlm->reco.resources);
1214 INIT_LIST_HEAD(&dlm->reco.received);
1215 INIT_LIST_HEAD(&dlm->reco.node_data);
1216 INIT_LIST_HEAD(&dlm->purge_list);
1217 INIT_LIST_HEAD(&dlm->dlm_domain_handlers);
1218 dlm->reco.state = 0;
1220 INIT_LIST_HEAD(&dlm->pending_asts);
1221 INIT_LIST_HEAD(&dlm->pending_basts);
1223 mlog(0, "dlm->recovery_map=%p, &(dlm->recovery_map[0])=%p\n",
1224 dlm->recovery_map, &(dlm->recovery_map[0]));
1226 memset(dlm->recovery_map, 0, sizeof(dlm->recovery_map));
1227 memset(dlm->live_nodes_map, 0, sizeof(dlm->live_nodes_map));
1228 memset(dlm->domain_map, 0, sizeof(dlm->domain_map));
1230 dlm->dlm_thread_task = NULL;
1231 dlm->dlm_reco_thread_task = NULL;
1232 init_waitqueue_head(&dlm->dlm_thread_wq);
1233 init_waitqueue_head(&dlm->dlm_reco_thread_wq);
1234 init_waitqueue_head(&dlm->reco.event);
1235 init_waitqueue_head(&dlm->ast_wq);
1236 init_waitqueue_head(&dlm->migration_wq);
1237 INIT_LIST_HEAD(&dlm->master_list);
1238 INIT_LIST_HEAD(&dlm->mle_hb_events);
1240 dlm->joining_node = DLM_LOCK_RES_OWNER_UNKNOWN;
1241 init_waitqueue_head(&dlm->dlm_join_events);
1243 dlm->reco.new_master = O2NM_INVALID_NODE_NUM;
1244 dlm->reco.dead_node = O2NM_INVALID_NODE_NUM;
1245 atomic_set(&dlm->local_resources, 0);
1246 atomic_set(&dlm->remote_resources, 0);
1247 atomic_set(&dlm->unknown_resources, 0);
1249 spin_lock_init(&dlm->work_lock);
1250 INIT_LIST_HEAD(&dlm->work_list);
1251 INIT_WORK(&dlm->dispatched_work, dlm_dispatch_work, dlm);
1253 kref_init(&dlm->dlm_refs);
1254 dlm->dlm_state = DLM_CTXT_NEW;
1256 INIT_LIST_HEAD(&dlm->dlm_eviction_callbacks);
1258 mlog(0, "context init: refcount %u\n",
1259 atomic_read(&dlm->dlm_refs.refcount));
1266 * dlm_register_domain: one-time setup per "domain"
1268 struct dlm_ctxt * dlm_register_domain(const char *domain,
1272 struct dlm_ctxt *dlm = NULL;
1273 struct dlm_ctxt *new_ctxt = NULL;
1275 if (strlen(domain) > O2NM_MAX_NAME_LEN) {
1276 ret = -ENAMETOOLONG;
1277 mlog(ML_ERROR, "domain name length too long\n");
1281 if (!o2hb_check_local_node_heartbeating()) {
1282 mlog(ML_ERROR, "the local node has not been configured, or is "
1283 "not heartbeating\n");
1288 mlog(0, "register called for domain \"%s\"\n", domain);
1292 if (signal_pending(current)) {
1298 spin_lock(&dlm_domain_lock);
1300 dlm = __dlm_lookup_domain(domain);
1302 if (dlm->dlm_state != DLM_CTXT_JOINED) {
1303 spin_unlock(&dlm_domain_lock);
1305 mlog(0, "This ctxt is not joined yet!\n");
1306 wait_event_interruptible(dlm_domain_events,
1307 dlm_wait_on_domain_helper(
1315 spin_unlock(&dlm_domain_lock);
1323 spin_unlock(&dlm_domain_lock);
1325 new_ctxt = dlm_alloc_ctxt(domain, key);
1334 /* a little variable switch-a-roo here... */
1338 /* add the new domain */
1339 list_add_tail(&dlm->list, &dlm_domains);
1340 spin_unlock(&dlm_domain_lock);
1342 ret = dlm_join_domain(dlm);
1352 dlm_free_ctxt_mem(new_ctxt);
1359 EXPORT_SYMBOL_GPL(dlm_register_domain);
1361 static LIST_HEAD(dlm_join_handlers);
1363 static void dlm_unregister_net_handlers(void)
1365 o2net_unregister_handler_list(&dlm_join_handlers);
1368 static int dlm_register_net_handlers(void)
1372 status = o2net_register_handler(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY,
1373 sizeof(struct dlm_query_join_request),
1374 dlm_query_join_handler,
1375 NULL, &dlm_join_handlers);
1379 status = o2net_register_handler(DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY,
1380 sizeof(struct dlm_assert_joined),
1381 dlm_assert_joined_handler,
1382 NULL, &dlm_join_handlers);
1386 status = o2net_register_handler(DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY,
1387 sizeof(struct dlm_cancel_join),
1388 dlm_cancel_join_handler,
1389 NULL, &dlm_join_handlers);
1393 dlm_unregister_net_handlers();
1398 /* Domain eviction callback handling.
1400 * The file system requires notification of node death *before* the
1401 * dlm completes it's recovery work, otherwise it may be able to
1402 * acquire locks on resources requiring recovery. Since the dlm can
1403 * evict a node from it's domain *before* heartbeat fires, a similar
1404 * mechanism is required. */
1406 /* Eviction is not expected to happen often, so a per-domain lock is
1407 * not necessary. Eviction callbacks are allowed to sleep for short
1408 * periods of time. */
1409 static DECLARE_RWSEM(dlm_callback_sem);
1411 void dlm_fire_domain_eviction_callbacks(struct dlm_ctxt *dlm,
1414 struct list_head *iter;
1415 struct dlm_eviction_cb *cb;
1417 down_read(&dlm_callback_sem);
1418 list_for_each(iter, &dlm->dlm_eviction_callbacks) {
1419 cb = list_entry(iter, struct dlm_eviction_cb, ec_item);
1421 cb->ec_func(node_num, cb->ec_data);
1423 up_read(&dlm_callback_sem);
1426 void dlm_setup_eviction_cb(struct dlm_eviction_cb *cb,
1427 dlm_eviction_func *f,
1430 INIT_LIST_HEAD(&cb->ec_item);
1434 EXPORT_SYMBOL_GPL(dlm_setup_eviction_cb);
1436 void dlm_register_eviction_cb(struct dlm_ctxt *dlm,
1437 struct dlm_eviction_cb *cb)
1439 down_write(&dlm_callback_sem);
1440 list_add_tail(&cb->ec_item, &dlm->dlm_eviction_callbacks);
1441 up_write(&dlm_callback_sem);
1443 EXPORT_SYMBOL_GPL(dlm_register_eviction_cb);
1445 void dlm_unregister_eviction_cb(struct dlm_eviction_cb *cb)
1447 down_write(&dlm_callback_sem);
1448 list_del_init(&cb->ec_item);
1449 up_write(&dlm_callback_sem);
1451 EXPORT_SYMBOL_GPL(dlm_unregister_eviction_cb);
1453 static int __init dlm_init(void)
1457 dlm_print_version();
1459 status = dlm_init_mle_cache();
1463 status = dlm_register_net_handlers();
1465 dlm_destroy_mle_cache();
1472 static void __exit dlm_exit (void)
1474 dlm_unregister_net_handlers();
1475 dlm_destroy_mle_cache();
1478 MODULE_AUTHOR("Oracle");
1479 MODULE_LICENSE("GPL");
1481 module_init(dlm_init);
1482 module_exit(dlm_exit);