1 /* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
6 * standalone DLM module
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.
28 #include <linux/module.h>
30 #include <linux/types.h>
31 #include <linux/slab.h>
32 #include <linux/highmem.h>
33 #include <linux/init.h>
34 #include <linux/sysctl.h>
35 #include <linux/random.h>
36 #include <linux/blkdev.h>
37 #include <linux/socket.h>
38 #include <linux/inet.h>
39 #include <linux/spinlock.h>
40 #include <linux/delay.h>
43 #include "cluster/heartbeat.h"
44 #include "cluster/nodemanager.h"
45 #include "cluster/tcp.h"
48 #include "dlmcommon.h"
49 #include "dlmdomain.h"
52 #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_MASTER)
53 #include "cluster/masklog.h"
55 static void dlm_mle_node_down(struct dlm_ctxt *dlm,
56 struct dlm_master_list_entry *mle,
57 struct o2nm_node *node,
59 static void dlm_mle_node_up(struct dlm_ctxt *dlm,
60 struct dlm_master_list_entry *mle,
61 struct o2nm_node *node,
64 static void dlm_assert_master_worker(struct dlm_work_item *item, void *data);
65 static int dlm_do_assert_master(struct dlm_ctxt *dlm,
66 struct dlm_lock_resource *res,
67 void *nodemap, u32 flags);
68 static void dlm_deref_lockres_worker(struct dlm_work_item *item, void *data);
70 static inline int dlm_mle_equal(struct dlm_ctxt *dlm,
71 struct dlm_master_list_entry *mle,
78 if (namelen != mle->mnamelen ||
79 memcmp(name, mle->mname, namelen) != 0)
85 static struct kmem_cache *dlm_lockres_cache;
86 static struct kmem_cache *dlm_lockname_cache;
87 static struct kmem_cache *dlm_mle_cache;
89 static void dlm_mle_release(struct kref *kref);
90 static void dlm_init_mle(struct dlm_master_list_entry *mle,
91 enum dlm_mle_type type,
93 struct dlm_lock_resource *res,
95 unsigned int namelen);
96 static void dlm_put_mle(struct dlm_master_list_entry *mle);
97 static void __dlm_put_mle(struct dlm_master_list_entry *mle);
98 static int dlm_find_mle(struct dlm_ctxt *dlm,
99 struct dlm_master_list_entry **mle,
100 char *name, unsigned int namelen);
102 static int dlm_do_master_request(struct dlm_lock_resource *res,
103 struct dlm_master_list_entry *mle, int to);
106 static int dlm_wait_for_lock_mastery(struct dlm_ctxt *dlm,
107 struct dlm_lock_resource *res,
108 struct dlm_master_list_entry *mle,
110 static int dlm_restart_lock_mastery(struct dlm_ctxt *dlm,
111 struct dlm_lock_resource *res,
112 struct dlm_master_list_entry *mle,
114 static int dlm_add_migration_mle(struct dlm_ctxt *dlm,
115 struct dlm_lock_resource *res,
116 struct dlm_master_list_entry *mle,
117 struct dlm_master_list_entry **oldmle,
118 const char *name, unsigned int namelen,
119 u8 new_master, u8 master);
121 static u8 dlm_pick_migration_target(struct dlm_ctxt *dlm,
122 struct dlm_lock_resource *res);
123 static void dlm_remove_nonlocal_locks(struct dlm_ctxt *dlm,
124 struct dlm_lock_resource *res);
125 static int dlm_mark_lockres_migrating(struct dlm_ctxt *dlm,
126 struct dlm_lock_resource *res,
128 static int dlm_pre_master_reco_lockres(struct dlm_ctxt *dlm,
129 struct dlm_lock_resource *res);
132 int dlm_is_host_down(int errno)
149 case -EINVAL: /* if returned from our tcp code,
150 this means there is no socket */
158 * MASTER LIST FUNCTIONS
163 * regarding master list entries and heartbeat callbacks:
165 * in order to avoid sleeping and allocation that occurs in
166 * heartbeat, master list entries are simply attached to the
167 * dlm's established heartbeat callbacks. the mle is attached
168 * when it is created, and since the dlm->spinlock is held at
169 * that time, any heartbeat event will be properly discovered
170 * by the mle. the mle needs to be detached from the
171 * dlm->mle_hb_events list as soon as heartbeat events are no
172 * longer useful to the mle, and before the mle is freed.
174 * as a general rule, heartbeat events are no longer needed by
175 * the mle once an "answer" regarding the lock master has been
178 static inline void __dlm_mle_attach_hb_events(struct dlm_ctxt *dlm,
179 struct dlm_master_list_entry *mle)
181 assert_spin_locked(&dlm->spinlock);
183 list_add_tail(&mle->hb_events, &dlm->mle_hb_events);
187 static inline void __dlm_mle_detach_hb_events(struct dlm_ctxt *dlm,
188 struct dlm_master_list_entry *mle)
190 if (!list_empty(&mle->hb_events))
191 list_del_init(&mle->hb_events);
195 static inline void dlm_mle_detach_hb_events(struct dlm_ctxt *dlm,
196 struct dlm_master_list_entry *mle)
198 spin_lock(&dlm->spinlock);
199 __dlm_mle_detach_hb_events(dlm, mle);
200 spin_unlock(&dlm->spinlock);
203 static void dlm_get_mle_inuse(struct dlm_master_list_entry *mle)
205 struct dlm_ctxt *dlm;
208 assert_spin_locked(&dlm->spinlock);
209 assert_spin_locked(&dlm->master_lock);
211 kref_get(&mle->mle_refs);
214 static void dlm_put_mle_inuse(struct dlm_master_list_entry *mle)
216 struct dlm_ctxt *dlm;
219 spin_lock(&dlm->spinlock);
220 spin_lock(&dlm->master_lock);
223 spin_unlock(&dlm->master_lock);
224 spin_unlock(&dlm->spinlock);
228 /* remove from list and free */
229 static void __dlm_put_mle(struct dlm_master_list_entry *mle)
231 struct dlm_ctxt *dlm;
234 assert_spin_locked(&dlm->spinlock);
235 assert_spin_locked(&dlm->master_lock);
236 if (!atomic_read(&mle->mle_refs.refcount)) {
237 /* this may or may not crash, but who cares.
239 mlog(ML_ERROR, "bad mle: %p\n", mle);
240 dlm_print_one_mle(mle);
243 kref_put(&mle->mle_refs, dlm_mle_release);
247 /* must not have any spinlocks coming in */
248 static void dlm_put_mle(struct dlm_master_list_entry *mle)
250 struct dlm_ctxt *dlm;
253 spin_lock(&dlm->spinlock);
254 spin_lock(&dlm->master_lock);
256 spin_unlock(&dlm->master_lock);
257 spin_unlock(&dlm->spinlock);
260 static inline void dlm_get_mle(struct dlm_master_list_entry *mle)
262 kref_get(&mle->mle_refs);
265 static void dlm_init_mle(struct dlm_master_list_entry *mle,
266 enum dlm_mle_type type,
267 struct dlm_ctxt *dlm,
268 struct dlm_lock_resource *res,
270 unsigned int namelen)
272 assert_spin_locked(&dlm->spinlock);
276 INIT_HLIST_NODE(&mle->master_hash_node);
277 INIT_LIST_HEAD(&mle->hb_events);
278 memset(mle->maybe_map, 0, sizeof(mle->maybe_map));
279 spin_lock_init(&mle->spinlock);
280 init_waitqueue_head(&mle->wq);
281 atomic_set(&mle->woken, 0);
282 kref_init(&mle->mle_refs);
283 memset(mle->response_map, 0, sizeof(mle->response_map));
284 mle->master = O2NM_MAX_NODES;
285 mle->new_master = O2NM_MAX_NODES;
288 BUG_ON(mle->type != DLM_MLE_BLOCK &&
289 mle->type != DLM_MLE_MASTER &&
290 mle->type != DLM_MLE_MIGRATION);
292 if (mle->type == DLM_MLE_MASTER) {
295 memcpy(mle->mname, res->lockname.name, res->lockname.len);
296 mle->mnamelen = res->lockname.len;
297 mle->mnamehash = res->lockname.hash;
301 memcpy(mle->mname, name, namelen);
302 mle->mnamelen = namelen;
303 mle->mnamehash = dlm_lockid_hash(name, namelen);
306 atomic_inc(&dlm->mle_tot_count[mle->type]);
307 atomic_inc(&dlm->mle_cur_count[mle->type]);
309 /* copy off the node_map and register hb callbacks on our copy */
310 memcpy(mle->node_map, dlm->domain_map, sizeof(mle->node_map));
311 memcpy(mle->vote_map, dlm->domain_map, sizeof(mle->vote_map));
312 clear_bit(dlm->node_num, mle->vote_map);
313 clear_bit(dlm->node_num, mle->node_map);
315 /* attach the mle to the domain node up/down events */
316 __dlm_mle_attach_hb_events(dlm, mle);
319 void __dlm_unlink_mle(struct dlm_ctxt *dlm, struct dlm_master_list_entry *mle)
321 assert_spin_locked(&dlm->spinlock);
322 assert_spin_locked(&dlm->master_lock);
324 if (!hlist_unhashed(&mle->master_hash_node))
325 hlist_del_init(&mle->master_hash_node);
328 void __dlm_insert_mle(struct dlm_ctxt *dlm, struct dlm_master_list_entry *mle)
330 struct hlist_head *bucket;
332 assert_spin_locked(&dlm->master_lock);
334 bucket = dlm_master_hash(dlm, mle->mnamehash);
335 hlist_add_head(&mle->master_hash_node, bucket);
338 /* returns 1 if found, 0 if not */
339 static int dlm_find_mle(struct dlm_ctxt *dlm,
340 struct dlm_master_list_entry **mle,
341 char *name, unsigned int namelen)
343 struct dlm_master_list_entry *tmpmle;
344 struct hlist_head *bucket;
347 assert_spin_locked(&dlm->master_lock);
349 hash = dlm_lockid_hash(name, namelen);
350 bucket = dlm_master_hash(dlm, hash);
351 hlist_for_each_entry(tmpmle, bucket, master_hash_node) {
352 if (!dlm_mle_equal(dlm, tmpmle, name, namelen))
361 void dlm_hb_event_notify_attached(struct dlm_ctxt *dlm, int idx, int node_up)
363 struct dlm_master_list_entry *mle;
365 assert_spin_locked(&dlm->spinlock);
367 list_for_each_entry(mle, &dlm->mle_hb_events, hb_events) {
369 dlm_mle_node_up(dlm, mle, NULL, idx);
371 dlm_mle_node_down(dlm, mle, NULL, idx);
375 static void dlm_mle_node_down(struct dlm_ctxt *dlm,
376 struct dlm_master_list_entry *mle,
377 struct o2nm_node *node, int idx)
379 spin_lock(&mle->spinlock);
381 if (!test_bit(idx, mle->node_map))
382 mlog(0, "node %u already removed from nodemap!\n", idx);
384 clear_bit(idx, mle->node_map);
386 spin_unlock(&mle->spinlock);
389 static void dlm_mle_node_up(struct dlm_ctxt *dlm,
390 struct dlm_master_list_entry *mle,
391 struct o2nm_node *node, int idx)
393 spin_lock(&mle->spinlock);
395 if (test_bit(idx, mle->node_map))
396 mlog(0, "node %u already in node map!\n", idx);
398 set_bit(idx, mle->node_map);
400 spin_unlock(&mle->spinlock);
404 int dlm_init_mle_cache(void)
406 dlm_mle_cache = kmem_cache_create("o2dlm_mle",
407 sizeof(struct dlm_master_list_entry),
408 0, SLAB_HWCACHE_ALIGN,
410 if (dlm_mle_cache == NULL)
415 void dlm_destroy_mle_cache(void)
418 kmem_cache_destroy(dlm_mle_cache);
421 static void dlm_mle_release(struct kref *kref)
423 struct dlm_master_list_entry *mle;
424 struct dlm_ctxt *dlm;
426 mle = container_of(kref, struct dlm_master_list_entry, mle_refs);
429 assert_spin_locked(&dlm->spinlock);
430 assert_spin_locked(&dlm->master_lock);
432 mlog(0, "Releasing mle for %.*s, type %d\n", mle->mnamelen, mle->mname,
435 /* remove from list if not already */
436 __dlm_unlink_mle(dlm, mle);
438 /* detach the mle from the domain node up/down events */
439 __dlm_mle_detach_hb_events(dlm, mle);
441 atomic_dec(&dlm->mle_cur_count[mle->type]);
443 /* NOTE: kfree under spinlock here.
444 * if this is bad, we can move this to a freelist. */
445 kmem_cache_free(dlm_mle_cache, mle);
450 * LOCK RESOURCE FUNCTIONS
453 int dlm_init_master_caches(void)
455 dlm_lockres_cache = kmem_cache_create("o2dlm_lockres",
456 sizeof(struct dlm_lock_resource),
457 0, SLAB_HWCACHE_ALIGN, NULL);
458 if (!dlm_lockres_cache)
461 dlm_lockname_cache = kmem_cache_create("o2dlm_lockname",
462 DLM_LOCKID_NAME_MAX, 0,
463 SLAB_HWCACHE_ALIGN, NULL);
464 if (!dlm_lockname_cache)
469 dlm_destroy_master_caches();
473 void dlm_destroy_master_caches(void)
475 if (dlm_lockname_cache) {
476 kmem_cache_destroy(dlm_lockname_cache);
477 dlm_lockname_cache = NULL;
480 if (dlm_lockres_cache) {
481 kmem_cache_destroy(dlm_lockres_cache);
482 dlm_lockres_cache = NULL;
486 static void dlm_lockres_release(struct kref *kref)
488 struct dlm_lock_resource *res;
489 struct dlm_ctxt *dlm;
491 res = container_of(kref, struct dlm_lock_resource, refs);
494 /* This should not happen -- all lockres' have a name
495 * associated with them at init time. */
496 BUG_ON(!res->lockname.name);
498 mlog(0, "destroying lockres %.*s\n", res->lockname.len,
501 atomic_dec(&dlm->res_cur_count);
503 if (!hlist_unhashed(&res->hash_node) ||
504 !list_empty(&res->granted) ||
505 !list_empty(&res->converting) ||
506 !list_empty(&res->blocked) ||
507 !list_empty(&res->dirty) ||
508 !list_empty(&res->recovering) ||
509 !list_empty(&res->purge)) {
511 "Going to BUG for resource %.*s."
512 " We're on a list! [%c%c%c%c%c%c%c]\n",
513 res->lockname.len, res->lockname.name,
514 !hlist_unhashed(&res->hash_node) ? 'H' : ' ',
515 !list_empty(&res->granted) ? 'G' : ' ',
516 !list_empty(&res->converting) ? 'C' : ' ',
517 !list_empty(&res->blocked) ? 'B' : ' ',
518 !list_empty(&res->dirty) ? 'D' : ' ',
519 !list_empty(&res->recovering) ? 'R' : ' ',
520 !list_empty(&res->purge) ? 'P' : ' ');
522 dlm_print_one_lock_resource(res);
525 /* By the time we're ready to blow this guy away, we shouldn't
526 * be on any lists. */
527 BUG_ON(!hlist_unhashed(&res->hash_node));
528 BUG_ON(!list_empty(&res->granted));
529 BUG_ON(!list_empty(&res->converting));
530 BUG_ON(!list_empty(&res->blocked));
531 BUG_ON(!list_empty(&res->dirty));
532 BUG_ON(!list_empty(&res->recovering));
533 BUG_ON(!list_empty(&res->purge));
535 kmem_cache_free(dlm_lockname_cache, (void *)res->lockname.name);
537 kmem_cache_free(dlm_lockres_cache, res);
540 void dlm_lockres_put(struct dlm_lock_resource *res)
542 kref_put(&res->refs, dlm_lockres_release);
545 static void dlm_init_lockres(struct dlm_ctxt *dlm,
546 struct dlm_lock_resource *res,
547 const char *name, unsigned int namelen)
551 /* If we memset here, we lose our reference to the kmalloc'd
552 * res->lockname.name, so be sure to init every field
555 qname = (char *) res->lockname.name;
556 memcpy(qname, name, namelen);
558 res->lockname.len = namelen;
559 res->lockname.hash = dlm_lockid_hash(name, namelen);
561 init_waitqueue_head(&res->wq);
562 spin_lock_init(&res->spinlock);
563 INIT_HLIST_NODE(&res->hash_node);
564 INIT_LIST_HEAD(&res->granted);
565 INIT_LIST_HEAD(&res->converting);
566 INIT_LIST_HEAD(&res->blocked);
567 INIT_LIST_HEAD(&res->dirty);
568 INIT_LIST_HEAD(&res->recovering);
569 INIT_LIST_HEAD(&res->purge);
570 INIT_LIST_HEAD(&res->tracking);
571 atomic_set(&res->asts_reserved, 0);
572 res->migration_pending = 0;
573 res->inflight_locks = 0;
574 res->inflight_assert_workers = 0;
578 kref_init(&res->refs);
580 atomic_inc(&dlm->res_tot_count);
581 atomic_inc(&dlm->res_cur_count);
583 /* just for consistency */
584 spin_lock(&res->spinlock);
585 dlm_set_lockres_owner(dlm, res, DLM_LOCK_RES_OWNER_UNKNOWN);
586 spin_unlock(&res->spinlock);
588 res->state = DLM_LOCK_RES_IN_PROGRESS;
592 spin_lock(&dlm->spinlock);
593 list_add_tail(&res->tracking, &dlm->tracking_list);
594 spin_unlock(&dlm->spinlock);
596 memset(res->lvb, 0, DLM_LVB_LEN);
597 memset(res->refmap, 0, sizeof(res->refmap));
600 struct dlm_lock_resource *dlm_new_lockres(struct dlm_ctxt *dlm,
602 unsigned int namelen)
604 struct dlm_lock_resource *res = NULL;
606 res = kmem_cache_zalloc(dlm_lockres_cache, GFP_NOFS);
610 res->lockname.name = kmem_cache_zalloc(dlm_lockname_cache, GFP_NOFS);
611 if (!res->lockname.name)
614 dlm_init_lockres(dlm, res, name, namelen);
619 kmem_cache_free(dlm_lockres_cache, res);
623 void dlm_lockres_set_refmap_bit(struct dlm_ctxt *dlm,
624 struct dlm_lock_resource *res, int bit)
626 assert_spin_locked(&res->spinlock);
628 mlog(0, "res %.*s, set node %u, %ps()\n", res->lockname.len,
629 res->lockname.name, bit, __builtin_return_address(0));
631 set_bit(bit, res->refmap);
634 void dlm_lockres_clear_refmap_bit(struct dlm_ctxt *dlm,
635 struct dlm_lock_resource *res, int bit)
637 assert_spin_locked(&res->spinlock);
639 mlog(0, "res %.*s, clr node %u, %ps()\n", res->lockname.len,
640 res->lockname.name, bit, __builtin_return_address(0));
642 clear_bit(bit, res->refmap);
645 static void __dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm,
646 struct dlm_lock_resource *res)
648 res->inflight_locks++;
650 mlog(0, "%s: res %.*s, inflight++: now %u, %ps()\n", dlm->name,
651 res->lockname.len, res->lockname.name, res->inflight_locks,
652 __builtin_return_address(0));
655 void dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm,
656 struct dlm_lock_resource *res)
658 assert_spin_locked(&res->spinlock);
659 __dlm_lockres_grab_inflight_ref(dlm, res);
662 void dlm_lockres_drop_inflight_ref(struct dlm_ctxt *dlm,
663 struct dlm_lock_resource *res)
665 assert_spin_locked(&res->spinlock);
667 BUG_ON(res->inflight_locks == 0);
669 res->inflight_locks--;
671 mlog(0, "%s: res %.*s, inflight--: now %u, %ps()\n", dlm->name,
672 res->lockname.len, res->lockname.name, res->inflight_locks,
673 __builtin_return_address(0));
678 void __dlm_lockres_grab_inflight_worker(struct dlm_ctxt *dlm,
679 struct dlm_lock_resource *res)
681 assert_spin_locked(&res->spinlock);
682 res->inflight_assert_workers++;
683 mlog(0, "%s:%.*s: inflight assert worker++: now %u\n",
684 dlm->name, res->lockname.len, res->lockname.name,
685 res->inflight_assert_workers);
688 static void __dlm_lockres_drop_inflight_worker(struct dlm_ctxt *dlm,
689 struct dlm_lock_resource *res)
691 assert_spin_locked(&res->spinlock);
692 BUG_ON(res->inflight_assert_workers == 0);
693 res->inflight_assert_workers--;
694 mlog(0, "%s:%.*s: inflight assert worker--: now %u\n",
695 dlm->name, res->lockname.len, res->lockname.name,
696 res->inflight_assert_workers);
699 static void dlm_lockres_drop_inflight_worker(struct dlm_ctxt *dlm,
700 struct dlm_lock_resource *res)
702 spin_lock(&res->spinlock);
703 __dlm_lockres_drop_inflight_worker(dlm, res);
704 spin_unlock(&res->spinlock);
708 * lookup a lock resource by name.
709 * may already exist in the hashtable.
710 * lockid is null terminated
712 * if not, allocate enough for the lockres and for
713 * the temporary structure used in doing the mastering.
715 * also, do a lookup in the dlm->master_list to see
716 * if another node has begun mastering the same lock.
717 * if so, there should be a block entry in there
718 * for this name, and we should *not* attempt to master
719 * the lock here. need to wait around for that node
720 * to assert_master (or die).
723 struct dlm_lock_resource * dlm_get_lock_resource(struct dlm_ctxt *dlm,
728 struct dlm_lock_resource *tmpres=NULL, *res=NULL;
729 struct dlm_master_list_entry *mle = NULL;
730 struct dlm_master_list_entry *alloc_mle = NULL;
733 struct dlm_node_iter iter;
736 int bit, wait_on_recovery = 0;
740 hash = dlm_lockid_hash(lockid, namelen);
742 mlog(0, "get lockres %s (len %d)\n", lockid, namelen);
745 spin_lock(&dlm->spinlock);
746 tmpres = __dlm_lookup_lockres_full(dlm, lockid, namelen, hash);
748 spin_unlock(&dlm->spinlock);
749 spin_lock(&tmpres->spinlock);
752 * Right after dlm spinlock was released, dlm_thread could have
753 * purged the lockres. Check if lockres got unhashed. If so
756 if (hlist_unhashed(&tmpres->hash_node)) {
757 spin_unlock(&tmpres->spinlock);
758 dlm_lockres_put(tmpres);
763 /* Wait on the thread that is mastering the resource */
764 if (tmpres->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
765 __dlm_wait_on_lockres(tmpres);
766 BUG_ON(tmpres->owner == DLM_LOCK_RES_OWNER_UNKNOWN);
767 spin_unlock(&tmpres->spinlock);
768 dlm_lockres_put(tmpres);
773 /* Wait on the resource purge to complete before continuing */
774 if (tmpres->state & DLM_LOCK_RES_DROPPING_REF) {
775 BUG_ON(tmpres->owner == dlm->node_num);
776 __dlm_wait_on_lockres_flags(tmpres,
777 DLM_LOCK_RES_DROPPING_REF);
778 spin_unlock(&tmpres->spinlock);
779 dlm_lockres_put(tmpres);
784 /* Grab inflight ref to pin the resource */
785 dlm_lockres_grab_inflight_ref(dlm, tmpres);
787 spin_unlock(&tmpres->spinlock);
789 spin_lock(&dlm->track_lock);
790 if (!list_empty(&res->tracking))
791 list_del_init(&res->tracking);
793 mlog(ML_ERROR, "Resource %.*s not "
794 "on the Tracking list\n",
797 spin_unlock(&dlm->track_lock);
798 dlm_lockres_put(res);
805 spin_unlock(&dlm->spinlock);
806 mlog(0, "allocating a new resource\n");
807 /* nothing found and we need to allocate one. */
808 alloc_mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
811 res = dlm_new_lockres(dlm, lockid, namelen);
817 mlog(0, "no lockres found, allocated our own: %p\n", res);
819 if (flags & LKM_LOCAL) {
820 /* caller knows it's safe to assume it's not mastered elsewhere
821 * DONE! return right away */
822 spin_lock(&res->spinlock);
823 dlm_change_lockres_owner(dlm, res, dlm->node_num);
824 __dlm_insert_lockres(dlm, res);
825 dlm_lockres_grab_inflight_ref(dlm, res);
826 spin_unlock(&res->spinlock);
827 spin_unlock(&dlm->spinlock);
828 /* lockres still marked IN_PROGRESS */
832 /* check master list to see if another node has started mastering it */
833 spin_lock(&dlm->master_lock);
835 /* if we found a block, wait for lock to be mastered by another node */
836 blocked = dlm_find_mle(dlm, &mle, (char *)lockid, namelen);
839 if (mle->type == DLM_MLE_MASTER) {
840 mlog(ML_ERROR, "master entry for nonexistent lock!\n");
843 mig = (mle->type == DLM_MLE_MIGRATION);
844 /* if there is a migration in progress, let the migration
845 * finish before continuing. we can wait for the absence
846 * of the MIGRATION mle: either the migrate finished or
847 * one of the nodes died and the mle was cleaned up.
848 * if there is a BLOCK here, but it already has a master
849 * set, we are too late. the master does not have a ref
850 * for us in the refmap. detach the mle and drop it.
851 * either way, go back to the top and start over. */
852 if (mig || mle->master != O2NM_MAX_NODES) {
853 BUG_ON(mig && mle->master == dlm->node_num);
854 /* we arrived too late. the master does not
855 * have a ref for us. retry. */
856 mlog(0, "%s:%.*s: late on %s\n",
857 dlm->name, namelen, lockid,
858 mig ? "MIGRATION" : "BLOCK");
859 spin_unlock(&dlm->master_lock);
860 spin_unlock(&dlm->spinlock);
862 /* master is known, detach */
864 dlm_mle_detach_hb_events(dlm, mle);
867 /* this is lame, but we can't wait on either
868 * the mle or lockres waitqueue here */
874 /* go ahead and try to master lock on this node */
876 /* make sure this does not get freed below */
878 dlm_init_mle(mle, DLM_MLE_MASTER, dlm, res, NULL, 0);
879 set_bit(dlm->node_num, mle->maybe_map);
880 __dlm_insert_mle(dlm, mle);
882 /* still holding the dlm spinlock, check the recovery map
883 * to see if there are any nodes that still need to be
884 * considered. these will not appear in the mle nodemap
885 * but they might own this lockres. wait on them. */
886 bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0);
887 if (bit < O2NM_MAX_NODES) {
888 mlog(0, "%s: res %.*s, At least one node (%d) "
889 "to recover before lock mastery can begin\n",
890 dlm->name, namelen, (char *)lockid, bit);
891 wait_on_recovery = 1;
895 /* at this point there is either a DLM_MLE_BLOCK or a
896 * DLM_MLE_MASTER on the master list, so it's safe to add the
897 * lockres to the hashtable. anyone who finds the lock will
898 * still have to wait on the IN_PROGRESS. */
900 /* finally add the lockres to its hash bucket */
901 __dlm_insert_lockres(dlm, res);
903 /* since this lockres is new it doesn't not require the spinlock */
904 __dlm_lockres_grab_inflight_ref(dlm, res);
906 /* get an extra ref on the mle in case this is a BLOCK
907 * if so, the creator of the BLOCK may try to put the last
908 * ref at this time in the assert master handler, so we
909 * need an extra one to keep from a bad ptr deref. */
910 dlm_get_mle_inuse(mle);
911 spin_unlock(&dlm->master_lock);
912 spin_unlock(&dlm->spinlock);
915 while (wait_on_recovery) {
916 /* any cluster changes that occurred after dropping the
917 * dlm spinlock would be detectable be a change on the mle,
918 * so we only need to clear out the recovery map once. */
919 if (dlm_is_recovery_lock(lockid, namelen)) {
920 mlog(0, "%s: Recovery map is not empty, but must "
921 "master $RECOVERY lock now\n", dlm->name);
922 if (!dlm_pre_master_reco_lockres(dlm, res))
923 wait_on_recovery = 0;
925 mlog(0, "%s: waiting 500ms for heartbeat state "
926 "change\n", dlm->name);
932 dlm_kick_recovery_thread(dlm);
934 dlm_wait_for_recovery(dlm);
936 spin_lock(&dlm->spinlock);
937 bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0);
938 if (bit < O2NM_MAX_NODES) {
939 mlog(0, "%s: res %.*s, At least one node (%d) "
940 "to recover before lock mastery can begin\n",
941 dlm->name, namelen, (char *)lockid, bit);
942 wait_on_recovery = 1;
944 wait_on_recovery = 0;
945 spin_unlock(&dlm->spinlock);
947 if (wait_on_recovery)
948 dlm_wait_for_node_recovery(dlm, bit, 10000);
951 /* must wait for lock to be mastered elsewhere */
956 dlm_node_iter_init(mle->vote_map, &iter);
957 while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
958 ret = dlm_do_master_request(res, mle, nodenum);
961 if (mle->master != O2NM_MAX_NODES) {
962 /* found a master ! */
963 if (mle->master <= nodenum)
965 /* if our master request has not reached the master
966 * yet, keep going until it does. this is how the
967 * master will know that asserts are needed back to
968 * the lower nodes. */
969 mlog(0, "%s: res %.*s, Requests only up to %u but "
970 "master is %u, keep going\n", dlm->name, namelen,
971 lockid, nodenum, mle->master);
976 /* keep going until the response map includes all nodes */
977 ret = dlm_wait_for_lock_mastery(dlm, res, mle, &blocked);
979 wait_on_recovery = 1;
980 mlog(0, "%s: res %.*s, Node map changed, redo the master "
981 "request now, blocked=%d\n", dlm->name, res->lockname.len,
982 res->lockname.name, blocked);
984 mlog(ML_ERROR, "%s: res %.*s, Spinning on "
985 "dlm_wait_for_lock_mastery, blocked = %d\n",
986 dlm->name, res->lockname.len,
987 res->lockname.name, blocked);
988 dlm_print_one_lock_resource(res);
989 dlm_print_one_mle(mle);
995 mlog(0, "%s: res %.*s, Mastered by %u\n", dlm->name, res->lockname.len,
996 res->lockname.name, res->owner);
997 /* make sure we never continue without this */
998 BUG_ON(res->owner == O2NM_MAX_NODES);
1000 /* master is known, detach if not already detached */
1001 dlm_mle_detach_hb_events(dlm, mle);
1003 /* put the extra ref */
1004 dlm_put_mle_inuse(mle);
1007 spin_lock(&res->spinlock);
1008 res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
1009 spin_unlock(&res->spinlock);
1013 /* need to free the unused mle */
1015 kmem_cache_free(dlm_mle_cache, alloc_mle);
1021 #define DLM_MASTERY_TIMEOUT_MS 5000
1023 static int dlm_wait_for_lock_mastery(struct dlm_ctxt *dlm,
1024 struct dlm_lock_resource *res,
1025 struct dlm_master_list_entry *mle,
1030 int map_changed, voting_done;
1037 /* check if another node has already become the owner */
1038 spin_lock(&res->spinlock);
1039 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
1040 mlog(0, "%s:%.*s: owner is suddenly %u\n", dlm->name,
1041 res->lockname.len, res->lockname.name, res->owner);
1042 spin_unlock(&res->spinlock);
1043 /* this will cause the master to re-assert across
1044 * the whole cluster, freeing up mles */
1045 if (res->owner != dlm->node_num) {
1046 ret = dlm_do_master_request(res, mle, res->owner);
1048 /* give recovery a chance to run */
1049 mlog(ML_ERROR, "link to %u went down?: %d\n", res->owner, ret);
1057 spin_unlock(&res->spinlock);
1059 spin_lock(&mle->spinlock);
1061 map_changed = (memcmp(mle->vote_map, mle->node_map,
1062 sizeof(mle->vote_map)) != 0);
1063 voting_done = (memcmp(mle->vote_map, mle->response_map,
1064 sizeof(mle->vote_map)) == 0);
1066 /* restart if we hit any errors */
1069 mlog(0, "%s: %.*s: node map changed, restarting\n",
1070 dlm->name, res->lockname.len, res->lockname.name);
1071 ret = dlm_restart_lock_mastery(dlm, res, mle, *blocked);
1072 b = (mle->type == DLM_MLE_BLOCK);
1073 if ((*blocked && !b) || (!*blocked && b)) {
1074 mlog(0, "%s:%.*s: status change: old=%d new=%d\n",
1075 dlm->name, res->lockname.len, res->lockname.name,
1079 spin_unlock(&mle->spinlock);
1084 mlog(0, "%s:%.*s: restart lock mastery succeeded, "
1085 "rechecking now\n", dlm->name, res->lockname.len,
1086 res->lockname.name);
1090 mlog(0, "map not changed and voting not done "
1091 "for %s:%.*s\n", dlm->name, res->lockname.len,
1092 res->lockname.name);
1096 if (m != O2NM_MAX_NODES) {
1097 /* another node has done an assert!
1102 /* have all nodes responded? */
1103 if (voting_done && !*blocked) {
1104 bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0);
1105 if (dlm->node_num <= bit) {
1106 /* my node number is lowest.
1107 * now tell other nodes that I am
1108 * mastering this. */
1109 mle->master = dlm->node_num;
1110 /* ref was grabbed in get_lock_resource
1111 * will be dropped in dlmlock_master */
1115 /* if voting is done, but we have not received
1116 * an assert master yet, we must sleep */
1120 spin_unlock(&mle->spinlock);
1122 /* sleep if we haven't finished voting yet */
1124 unsigned long timeo = msecs_to_jiffies(DLM_MASTERY_TIMEOUT_MS);
1127 if (atomic_read(&mle->mle_refs.refcount) < 2)
1128 mlog(ML_ERROR, "mle (%p) refs=%d, name=%.*s\n", mle,
1129 atomic_read(&mle->mle_refs.refcount),
1130 res->lockname.len, res->lockname.name);
1132 atomic_set(&mle->woken, 0);
1133 (void)wait_event_timeout(mle->wq,
1134 (atomic_read(&mle->woken) == 1),
1136 if (res->owner == O2NM_MAX_NODES) {
1137 mlog(0, "%s:%.*s: waiting again\n", dlm->name,
1138 res->lockname.len, res->lockname.name);
1141 mlog(0, "done waiting, master is %u\n", res->owner);
1149 mlog(0, "about to master %.*s here, this=%u\n",
1150 res->lockname.len, res->lockname.name, m);
1151 ret = dlm_do_assert_master(dlm, res, mle->vote_map, 0);
1153 /* This is a failure in the network path,
1154 * not in the response to the assert_master
1155 * (any nonzero response is a BUG on this node).
1156 * Most likely a socket just got disconnected
1157 * due to node death. */
1160 /* no longer need to restart lock mastery.
1161 * all living nodes have been contacted. */
1165 /* set the lockres owner */
1166 spin_lock(&res->spinlock);
1167 /* mastery reference obtained either during
1168 * assert_master_handler or in get_lock_resource */
1169 dlm_change_lockres_owner(dlm, res, m);
1170 spin_unlock(&res->spinlock);
1176 struct dlm_bitmap_diff_iter
1179 unsigned long *orig_bm;
1180 unsigned long *cur_bm;
1181 unsigned long diff_bm[BITS_TO_LONGS(O2NM_MAX_NODES)];
1184 enum dlm_node_state_change
1191 static void dlm_bitmap_diff_iter_init(struct dlm_bitmap_diff_iter *iter,
1192 unsigned long *orig_bm,
1193 unsigned long *cur_bm)
1195 unsigned long p1, p2;
1199 iter->orig_bm = orig_bm;
1200 iter->cur_bm = cur_bm;
1202 for (i = 0; i < BITS_TO_LONGS(O2NM_MAX_NODES); i++) {
1203 p1 = *(iter->orig_bm + i);
1204 p2 = *(iter->cur_bm + i);
1205 iter->diff_bm[i] = (p1 & ~p2) | (p2 & ~p1);
1209 static int dlm_bitmap_diff_iter_next(struct dlm_bitmap_diff_iter *iter,
1210 enum dlm_node_state_change *state)
1214 if (iter->curnode >= O2NM_MAX_NODES)
1217 bit = find_next_bit(iter->diff_bm, O2NM_MAX_NODES,
1219 if (bit >= O2NM_MAX_NODES) {
1220 iter->curnode = O2NM_MAX_NODES;
1224 /* if it was there in the original then this node died */
1225 if (test_bit(bit, iter->orig_bm))
1230 iter->curnode = bit;
1235 static int dlm_restart_lock_mastery(struct dlm_ctxt *dlm,
1236 struct dlm_lock_resource *res,
1237 struct dlm_master_list_entry *mle,
1240 struct dlm_bitmap_diff_iter bdi;
1241 enum dlm_node_state_change sc;
1245 mlog(0, "something happened such that the "
1246 "master process may need to be restarted!\n");
1248 assert_spin_locked(&mle->spinlock);
1250 dlm_bitmap_diff_iter_init(&bdi, mle->vote_map, mle->node_map);
1251 node = dlm_bitmap_diff_iter_next(&bdi, &sc);
1253 if (sc == NODE_UP) {
1254 /* a node came up. clear any old vote from
1255 * the response map and set it in the vote map
1256 * then restart the mastery. */
1257 mlog(ML_NOTICE, "node %d up while restarting\n", node);
1259 /* redo the master request, but only for the new node */
1260 mlog(0, "sending request to new node\n");
1261 clear_bit(node, mle->response_map);
1262 set_bit(node, mle->vote_map);
1264 mlog(ML_ERROR, "node down! %d\n", node);
1266 int lowest = find_next_bit(mle->maybe_map,
1269 /* act like it was never there */
1270 clear_bit(node, mle->maybe_map);
1272 if (node == lowest) {
1273 mlog(0, "expected master %u died"
1274 " while this node was blocked "
1275 "waiting on it!\n", node);
1276 lowest = find_next_bit(mle->maybe_map,
1279 if (lowest < O2NM_MAX_NODES) {
1280 mlog(0, "%s:%.*s:still "
1281 "blocked. waiting on %u "
1287 /* mle is an MLE_BLOCK, but
1288 * there is now nothing left to
1289 * block on. we need to return
1290 * all the way back out and try
1291 * again with an MLE_MASTER.
1292 * dlm_do_local_recovery_cleanup
1293 * has already run, so the mle
1295 mlog(0, "%s:%.*s: no "
1296 "longer blocking. try to "
1297 "master this here\n",
1300 res->lockname.name);
1301 mle->type = DLM_MLE_MASTER;
1307 /* now blank out everything, as if we had never
1308 * contacted anyone */
1309 memset(mle->maybe_map, 0, sizeof(mle->maybe_map));
1310 memset(mle->response_map, 0, sizeof(mle->response_map));
1311 /* reset the vote_map to the current node_map */
1312 memcpy(mle->vote_map, mle->node_map,
1313 sizeof(mle->node_map));
1314 /* put myself into the maybe map */
1315 if (mle->type != DLM_MLE_BLOCK)
1316 set_bit(dlm->node_num, mle->maybe_map);
1319 node = dlm_bitmap_diff_iter_next(&bdi, &sc);
1326 * DLM_MASTER_REQUEST_MSG
1328 * returns: 0 on success,
1329 * -errno on a network error
1331 * on error, the caller should assume the target node is "dead"
1335 static int dlm_do_master_request(struct dlm_lock_resource *res,
1336 struct dlm_master_list_entry *mle, int to)
1338 struct dlm_ctxt *dlm = mle->dlm;
1339 struct dlm_master_request request;
1340 int ret, response=0, resend;
1342 memset(&request, 0, sizeof(request));
1343 request.node_idx = dlm->node_num;
1345 BUG_ON(mle->type == DLM_MLE_MIGRATION);
1347 request.namelen = (u8)mle->mnamelen;
1348 memcpy(request.name, mle->mname, request.namelen);
1351 ret = o2net_send_message(DLM_MASTER_REQUEST_MSG, dlm->key, &request,
1352 sizeof(request), to, &response);
1354 if (ret == -ESRCH) {
1355 /* should never happen */
1356 mlog(ML_ERROR, "TCP stack not ready!\n");
1358 } else if (ret == -EINVAL) {
1359 mlog(ML_ERROR, "bad args passed to o2net!\n");
1361 } else if (ret == -ENOMEM) {
1362 mlog(ML_ERROR, "out of memory while trying to send "
1363 "network message! retrying\n");
1364 /* this is totally crude */
1367 } else if (!dlm_is_host_down(ret)) {
1368 /* not a network error. bad. */
1370 mlog(ML_ERROR, "unhandled error!");
1373 /* all other errors should be network errors,
1374 * and likely indicate node death */
1375 mlog(ML_ERROR, "link to %d went down!\n", to);
1381 spin_lock(&mle->spinlock);
1383 case DLM_MASTER_RESP_YES:
1384 set_bit(to, mle->response_map);
1385 mlog(0, "node %u is the master, response=YES\n", to);
1386 mlog(0, "%s:%.*s: master node %u now knows I have a "
1387 "reference\n", dlm->name, res->lockname.len,
1388 res->lockname.name, to);
1391 case DLM_MASTER_RESP_NO:
1392 mlog(0, "node %u not master, response=NO\n", to);
1393 set_bit(to, mle->response_map);
1395 case DLM_MASTER_RESP_MAYBE:
1396 mlog(0, "node %u not master, response=MAYBE\n", to);
1397 set_bit(to, mle->response_map);
1398 set_bit(to, mle->maybe_map);
1400 case DLM_MASTER_RESP_ERROR:
1401 mlog(0, "node %u hit an error, resending\n", to);
1406 mlog(ML_ERROR, "bad response! %u\n", response);
1409 spin_unlock(&mle->spinlock);
1411 /* this is also totally crude */
1421 * locks that can be taken here:
1427 * if possible, TRIM THIS DOWN!!!
1429 int dlm_master_request_handler(struct o2net_msg *msg, u32 len, void *data,
1432 u8 response = DLM_MASTER_RESP_MAYBE;
1433 struct dlm_ctxt *dlm = data;
1434 struct dlm_lock_resource *res = NULL;
1435 struct dlm_master_request *request = (struct dlm_master_request *) msg->buf;
1436 struct dlm_master_list_entry *mle = NULL, *tmpmle = NULL;
1438 unsigned int namelen, hash;
1441 int dispatch_assert = 0;
1445 return DLM_MASTER_RESP_NO;
1447 if (!dlm_domain_fully_joined(dlm)) {
1448 response = DLM_MASTER_RESP_NO;
1452 name = request->name;
1453 namelen = request->namelen;
1454 hash = dlm_lockid_hash(name, namelen);
1456 if (namelen > DLM_LOCKID_NAME_MAX) {
1457 response = DLM_IVBUFLEN;
1462 spin_lock(&dlm->spinlock);
1463 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
1465 spin_unlock(&dlm->spinlock);
1467 /* take care of the easy cases up front */
1468 spin_lock(&res->spinlock);
1471 * Right after dlm spinlock was released, dlm_thread could have
1472 * purged the lockres. Check if lockres got unhashed. If so
1475 if (hlist_unhashed(&res->hash_node)) {
1476 spin_unlock(&res->spinlock);
1477 dlm_lockres_put(res);
1481 if (res->state & (DLM_LOCK_RES_RECOVERING|
1482 DLM_LOCK_RES_MIGRATING)) {
1483 spin_unlock(&res->spinlock);
1484 mlog(0, "returning DLM_MASTER_RESP_ERROR since res is "
1485 "being recovered/migrated\n");
1486 response = DLM_MASTER_RESP_ERROR;
1488 kmem_cache_free(dlm_mle_cache, mle);
1492 if (res->owner == dlm->node_num) {
1493 dlm_lockres_set_refmap_bit(dlm, res, request->node_idx);
1494 spin_unlock(&res->spinlock);
1495 response = DLM_MASTER_RESP_YES;
1497 kmem_cache_free(dlm_mle_cache, mle);
1499 /* this node is the owner.
1500 * there is some extra work that needs to
1501 * happen now. the requesting node has
1502 * caused all nodes up to this one to
1503 * create mles. this node now needs to
1504 * go back and clean those up. */
1505 dispatch_assert = 1;
1507 } else if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
1508 spin_unlock(&res->spinlock);
1509 // mlog(0, "node %u is the master\n", res->owner);
1510 response = DLM_MASTER_RESP_NO;
1512 kmem_cache_free(dlm_mle_cache, mle);
1516 /* ok, there is no owner. either this node is
1517 * being blocked, or it is actively trying to
1518 * master this lock. */
1519 if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) {
1520 mlog(ML_ERROR, "lock with no owner should be "
1525 // mlog(0, "lockres is in progress...\n");
1526 spin_lock(&dlm->master_lock);
1527 found = dlm_find_mle(dlm, &tmpmle, name, namelen);
1529 mlog(ML_ERROR, "no mle found for this lock!\n");
1533 spin_lock(&tmpmle->spinlock);
1534 if (tmpmle->type == DLM_MLE_BLOCK) {
1535 // mlog(0, "this node is waiting for "
1536 // "lockres to be mastered\n");
1537 response = DLM_MASTER_RESP_NO;
1538 } else if (tmpmle->type == DLM_MLE_MIGRATION) {
1539 mlog(0, "node %u is master, but trying to migrate to "
1540 "node %u.\n", tmpmle->master, tmpmle->new_master);
1541 if (tmpmle->master == dlm->node_num) {
1542 mlog(ML_ERROR, "no owner on lockres, but this "
1543 "node is trying to migrate it to %u?!\n",
1544 tmpmle->new_master);
1547 /* the real master can respond on its own */
1548 response = DLM_MASTER_RESP_NO;
1550 } else if (tmpmle->master != DLM_LOCK_RES_OWNER_UNKNOWN) {
1552 if (tmpmle->master == dlm->node_num) {
1553 response = DLM_MASTER_RESP_YES;
1554 /* this node will be the owner.
1555 * go back and clean the mles on any
1557 dispatch_assert = 1;
1558 dlm_lockres_set_refmap_bit(dlm, res,
1561 response = DLM_MASTER_RESP_NO;
1563 // mlog(0, "this node is attempting to "
1564 // "master lockres\n");
1565 response = DLM_MASTER_RESP_MAYBE;
1568 set_bit(request->node_idx, tmpmle->maybe_map);
1569 spin_unlock(&tmpmle->spinlock);
1571 spin_unlock(&dlm->master_lock);
1572 spin_unlock(&res->spinlock);
1574 /* keep the mle attached to heartbeat events */
1575 dlm_put_mle(tmpmle);
1577 kmem_cache_free(dlm_mle_cache, mle);
1582 * lockres doesn't exist on this node
1583 * if there is an MLE_BLOCK, return NO
1584 * if there is an MLE_MASTER, return MAYBE
1585 * otherwise, add an MLE_BLOCK, return NO
1587 spin_lock(&dlm->master_lock);
1588 found = dlm_find_mle(dlm, &tmpmle, name, namelen);
1590 /* this lockid has never been seen on this node yet */
1591 // mlog(0, "no mle found\n");
1593 spin_unlock(&dlm->master_lock);
1594 spin_unlock(&dlm->spinlock);
1596 mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
1598 response = DLM_MASTER_RESP_ERROR;
1599 mlog_errno(-ENOMEM);
1605 // mlog(0, "this is second time thru, already allocated, "
1606 // "add the block.\n");
1607 dlm_init_mle(mle, DLM_MLE_BLOCK, dlm, NULL, name, namelen);
1608 set_bit(request->node_idx, mle->maybe_map);
1609 __dlm_insert_mle(dlm, mle);
1610 response = DLM_MASTER_RESP_NO;
1612 // mlog(0, "mle was found\n");
1614 spin_lock(&tmpmle->spinlock);
1615 if (tmpmle->master == dlm->node_num) {
1616 mlog(ML_ERROR, "no lockres, but an mle with this node as master!\n");
1619 if (tmpmle->type == DLM_MLE_BLOCK)
1620 response = DLM_MASTER_RESP_NO;
1621 else if (tmpmle->type == DLM_MLE_MIGRATION) {
1622 mlog(0, "migration mle was found (%u->%u)\n",
1623 tmpmle->master, tmpmle->new_master);
1624 /* real master can respond on its own */
1625 response = DLM_MASTER_RESP_NO;
1627 response = DLM_MASTER_RESP_MAYBE;
1629 set_bit(request->node_idx, tmpmle->maybe_map);
1630 spin_unlock(&tmpmle->spinlock);
1632 spin_unlock(&dlm->master_lock);
1633 spin_unlock(&dlm->spinlock);
1636 /* keep the mle attached to heartbeat events */
1637 dlm_put_mle(tmpmle);
1641 * __dlm_lookup_lockres() grabbed a reference to this lockres.
1642 * The reference is released by dlm_assert_master_worker() under
1643 * the call to dlm_dispatch_assert_master(). If
1644 * dlm_assert_master_worker() isn't called, we drop it here.
1646 if (dispatch_assert) {
1647 if (response != DLM_MASTER_RESP_YES)
1648 mlog(ML_ERROR, "invalid response %d\n", response);
1650 mlog(ML_ERROR, "bad lockres while trying to assert!\n");
1653 mlog(0, "%u is the owner of %.*s, cleaning everyone else\n",
1654 dlm->node_num, res->lockname.len, res->lockname.name);
1655 spin_lock(&res->spinlock);
1656 ret = dlm_dispatch_assert_master(dlm, res, 0, request->node_idx,
1657 DLM_ASSERT_MASTER_MLE_CLEANUP);
1659 mlog(ML_ERROR, "failed to dispatch assert master work\n");
1660 response = DLM_MASTER_RESP_ERROR;
1661 spin_unlock(&res->spinlock);
1662 dlm_lockres_put(res);
1665 __dlm_lockres_grab_inflight_worker(dlm, res);
1666 spin_unlock(&res->spinlock);
1670 dlm_lockres_put(res);
1679 * DLM_ASSERT_MASTER_MSG
1684 * NOTE: this can be used for debugging
1685 * can periodically run all locks owned by this node
1686 * and re-assert across the cluster...
1688 static int dlm_do_assert_master(struct dlm_ctxt *dlm,
1689 struct dlm_lock_resource *res,
1690 void *nodemap, u32 flags)
1692 struct dlm_assert_master assert;
1694 struct dlm_node_iter iter;
1697 const char *lockname = res->lockname.name;
1698 unsigned int namelen = res->lockname.len;
1700 BUG_ON(namelen > O2NM_MAX_NAME_LEN);
1702 spin_lock(&res->spinlock);
1703 res->state |= DLM_LOCK_RES_SETREF_INPROG;
1704 spin_unlock(&res->spinlock);
1709 /* note that if this nodemap is empty, it returns 0 */
1710 dlm_node_iter_init(nodemap, &iter);
1711 while ((to = dlm_node_iter_next(&iter)) >= 0) {
1713 struct dlm_master_list_entry *mle = NULL;
1715 mlog(0, "sending assert master to %d (%.*s)\n", to,
1717 memset(&assert, 0, sizeof(assert));
1718 assert.node_idx = dlm->node_num;
1719 assert.namelen = namelen;
1720 memcpy(assert.name, lockname, namelen);
1721 assert.flags = cpu_to_be32(flags);
1723 tmpret = o2net_send_message(DLM_ASSERT_MASTER_MSG, dlm->key,
1724 &assert, sizeof(assert), to, &r);
1726 mlog(ML_ERROR, "Error %d when sending message %u (key "
1727 "0x%x) to node %u\n", tmpret,
1728 DLM_ASSERT_MASTER_MSG, dlm->key, to);
1729 if (!dlm_is_host_down(tmpret)) {
1730 mlog(ML_ERROR, "unhandled error=%d!\n", tmpret);
1733 /* a node died. finish out the rest of the nodes. */
1734 mlog(0, "link to %d went down!\n", to);
1735 /* any nonzero status return will do */
1739 /* ok, something horribly messed. kill thyself. */
1740 mlog(ML_ERROR,"during assert master of %.*s to %u, "
1741 "got %d.\n", namelen, lockname, to, r);
1742 spin_lock(&dlm->spinlock);
1743 spin_lock(&dlm->master_lock);
1744 if (dlm_find_mle(dlm, &mle, (char *)lockname,
1746 dlm_print_one_mle(mle);
1749 spin_unlock(&dlm->master_lock);
1750 spin_unlock(&dlm->spinlock);
1754 if (r & DLM_ASSERT_RESPONSE_REASSERT &&
1755 !(r & DLM_ASSERT_RESPONSE_MASTERY_REF)) {
1756 mlog(ML_ERROR, "%.*s: very strange, "
1757 "master MLE but no lockres on %u\n",
1758 namelen, lockname, to);
1761 if (r & DLM_ASSERT_RESPONSE_REASSERT) {
1762 mlog(0, "%.*s: node %u create mles on other "
1763 "nodes and requests a re-assert\n",
1764 namelen, lockname, to);
1767 if (r & DLM_ASSERT_RESPONSE_MASTERY_REF) {
1768 mlog(0, "%.*s: node %u has a reference to this "
1769 "lockres, set the bit in the refmap\n",
1770 namelen, lockname, to);
1771 spin_lock(&res->spinlock);
1772 dlm_lockres_set_refmap_bit(dlm, res, to);
1773 spin_unlock(&res->spinlock);
1780 spin_lock(&res->spinlock);
1781 res->state &= ~DLM_LOCK_RES_SETREF_INPROG;
1782 spin_unlock(&res->spinlock);
1789 * locks that can be taken here:
1795 * if possible, TRIM THIS DOWN!!!
1797 int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data,
1800 struct dlm_ctxt *dlm = data;
1801 struct dlm_master_list_entry *mle = NULL;
1802 struct dlm_assert_master *assert = (struct dlm_assert_master *)msg->buf;
1803 struct dlm_lock_resource *res = NULL;
1805 unsigned int namelen, hash;
1807 int master_request = 0, have_lockres_ref = 0;
1813 name = assert->name;
1814 namelen = assert->namelen;
1815 hash = dlm_lockid_hash(name, namelen);
1816 flags = be32_to_cpu(assert->flags);
1818 if (namelen > DLM_LOCKID_NAME_MAX) {
1819 mlog(ML_ERROR, "Invalid name length!");
1823 spin_lock(&dlm->spinlock);
1826 mlog(0, "assert_master with flags: %u\n", flags);
1829 spin_lock(&dlm->master_lock);
1830 if (!dlm_find_mle(dlm, &mle, name, namelen)) {
1831 /* not an error, could be master just re-asserting */
1832 mlog(0, "just got an assert_master from %u, but no "
1833 "MLE for it! (%.*s)\n", assert->node_idx,
1836 int bit = find_next_bit (mle->maybe_map, O2NM_MAX_NODES, 0);
1837 if (bit >= O2NM_MAX_NODES) {
1838 /* not necessarily an error, though less likely.
1839 * could be master just re-asserting. */
1840 mlog(0, "no bits set in the maybe_map, but %u "
1841 "is asserting! (%.*s)\n", assert->node_idx,
1843 } else if (bit != assert->node_idx) {
1844 if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) {
1845 mlog(0, "master %u was found, %u should "
1846 "back off\n", assert->node_idx, bit);
1848 /* with the fix for bug 569, a higher node
1849 * number winning the mastery will respond
1850 * YES to mastery requests, but this node
1851 * had no way of knowing. let it pass. */
1852 mlog(0, "%u is the lowest node, "
1853 "%u is asserting. (%.*s) %u must "
1854 "have begun after %u won.\n", bit,
1855 assert->node_idx, namelen, name, bit,
1859 if (mle->type == DLM_MLE_MIGRATION) {
1860 if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) {
1861 mlog(0, "%s:%.*s: got cleanup assert"
1862 " from %u for migration\n",
1863 dlm->name, namelen, name,
1865 } else if (!(flags & DLM_ASSERT_MASTER_FINISH_MIGRATION)) {
1866 mlog(0, "%s:%.*s: got unrelated assert"
1867 " from %u for migration, ignoring\n",
1868 dlm->name, namelen, name,
1871 spin_unlock(&dlm->master_lock);
1872 spin_unlock(&dlm->spinlock);
1877 spin_unlock(&dlm->master_lock);
1879 /* ok everything checks out with the MLE
1880 * now check to see if there is a lockres */
1881 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
1883 spin_lock(&res->spinlock);
1884 if (res->state & DLM_LOCK_RES_RECOVERING) {
1885 mlog(ML_ERROR, "%u asserting but %.*s is "
1886 "RECOVERING!\n", assert->node_idx, namelen, name);
1890 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN &&
1891 res->owner != assert->node_idx) {
1892 mlog(ML_ERROR, "DIE! Mastery assert from %u, "
1893 "but current owner is %u! (%.*s)\n",
1894 assert->node_idx, res->owner, namelen,
1896 __dlm_print_one_lock_resource(res);
1899 } else if (mle->type != DLM_MLE_MIGRATION) {
1900 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
1901 /* owner is just re-asserting */
1902 if (res->owner == assert->node_idx) {
1903 mlog(0, "owner %u re-asserting on "
1904 "lock %.*s\n", assert->node_idx,
1908 mlog(ML_ERROR, "got assert_master from "
1909 "node %u, but %u is the owner! "
1910 "(%.*s)\n", assert->node_idx,
1911 res->owner, namelen, name);
1914 if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) {
1915 mlog(ML_ERROR, "got assert from %u, but lock "
1916 "with no owner should be "
1917 "in-progress! (%.*s)\n",
1922 } else /* mle->type == DLM_MLE_MIGRATION */ {
1923 /* should only be getting an assert from new master */
1924 if (assert->node_idx != mle->new_master) {
1925 mlog(ML_ERROR, "got assert from %u, but "
1926 "new master is %u, and old master "
1928 assert->node_idx, mle->new_master,
1929 mle->master, namelen, name);
1935 spin_unlock(&res->spinlock);
1938 // mlog(0, "woo! got an assert_master from node %u!\n",
1939 // assert->node_idx);
1945 spin_lock(&mle->spinlock);
1946 if (mle->type == DLM_MLE_BLOCK || mle->type == DLM_MLE_MIGRATION)
1949 /* MASTER mle: if any bits set in the response map
1950 * then the calling node needs to re-assert to clear
1951 * up nodes that this node contacted */
1952 while ((nn = find_next_bit (mle->response_map, O2NM_MAX_NODES,
1953 nn+1)) < O2NM_MAX_NODES) {
1954 if (nn != dlm->node_num && nn != assert->node_idx) {
1960 mle->master = assert->node_idx;
1961 atomic_set(&mle->woken, 1);
1963 spin_unlock(&mle->spinlock);
1967 spin_lock(&res->spinlock);
1968 if (mle->type == DLM_MLE_MIGRATION) {
1969 mlog(0, "finishing off migration of lockres %.*s, "
1971 res->lockname.len, res->lockname.name,
1972 dlm->node_num, mle->new_master);
1973 res->state &= ~DLM_LOCK_RES_MIGRATING;
1975 dlm_change_lockres_owner(dlm, res, mle->new_master);
1976 BUG_ON(res->state & DLM_LOCK_RES_DIRTY);
1978 dlm_change_lockres_owner(dlm, res, mle->master);
1980 spin_unlock(&res->spinlock);
1981 have_lockres_ref = 1;
1986 /* master is known, detach if not already detached.
1987 * ensures that only one assert_master call will happen
1989 spin_lock(&dlm->master_lock);
1991 rr = atomic_read(&mle->mle_refs.refcount);
1992 if (mle->inuse > 0) {
1993 if (extra_ref && rr < 3)
1995 else if (!extra_ref && rr < 2)
1998 if (extra_ref && rr < 2)
2000 else if (!extra_ref && rr < 1)
2004 mlog(ML_ERROR, "%s:%.*s: got assert master from %u "
2005 "that will mess up this node, refs=%d, extra=%d, "
2006 "inuse=%d\n", dlm->name, namelen, name,
2007 assert->node_idx, rr, extra_ref, mle->inuse);
2008 dlm_print_one_mle(mle);
2010 __dlm_unlink_mle(dlm, mle);
2011 __dlm_mle_detach_hb_events(dlm, mle);
2014 /* the assert master message now balances the extra
2015 * ref given by the master / migration request message.
2016 * if this is the last put, it will be removed
2020 spin_unlock(&dlm->master_lock);
2022 if (res->owner != assert->node_idx) {
2023 mlog(0, "assert_master from %u, but current "
2024 "owner is %u (%.*s), no mle\n", assert->node_idx,
2025 res->owner, namelen, name);
2028 spin_unlock(&dlm->spinlock);
2033 spin_lock(&res->spinlock);
2034 res->state |= DLM_LOCK_RES_SETREF_INPROG;
2035 spin_unlock(&res->spinlock);
2036 *ret_data = (void *)res;
2039 if (master_request) {
2040 mlog(0, "need to tell master to reassert\n");
2041 /* positive. negative would shoot down the node. */
2042 ret |= DLM_ASSERT_RESPONSE_REASSERT;
2043 if (!have_lockres_ref) {
2044 mlog(ML_ERROR, "strange, got assert from %u, MASTER "
2045 "mle present here for %s:%.*s, but no lockres!\n",
2046 assert->node_idx, dlm->name, namelen, name);
2049 if (have_lockres_ref) {
2050 /* let the master know we have a reference to the lockres */
2051 ret |= DLM_ASSERT_RESPONSE_MASTERY_REF;
2052 mlog(0, "%s:%.*s: got assert from %u, need a ref\n",
2053 dlm->name, namelen, name, assert->node_idx);
2058 /* kill the caller! */
2059 mlog(ML_ERROR, "Bad message received from another node. Dumping state "
2060 "and killing the other node now! This node is OK and can continue.\n");
2061 __dlm_print_one_lock_resource(res);
2062 spin_unlock(&res->spinlock);
2063 spin_lock(&dlm->master_lock);
2066 spin_unlock(&dlm->master_lock);
2067 spin_unlock(&dlm->spinlock);
2068 *ret_data = (void *)res;
2073 void dlm_assert_master_post_handler(int status, void *data, void *ret_data)
2075 struct dlm_lock_resource *res = (struct dlm_lock_resource *)ret_data;
2078 spin_lock(&res->spinlock);
2079 res->state &= ~DLM_LOCK_RES_SETREF_INPROG;
2080 spin_unlock(&res->spinlock);
2082 dlm_lockres_put(res);
2087 int dlm_dispatch_assert_master(struct dlm_ctxt *dlm,
2088 struct dlm_lock_resource *res,
2089 int ignore_higher, u8 request_from, u32 flags)
2091 struct dlm_work_item *item;
2092 item = kzalloc(sizeof(*item), GFP_ATOMIC);
2097 /* queue up work for dlm_assert_master_worker */
2098 dlm_init_work_item(dlm, item, dlm_assert_master_worker, NULL);
2099 item->u.am.lockres = res; /* already have a ref */
2100 /* can optionally ignore node numbers higher than this node */
2101 item->u.am.ignore_higher = ignore_higher;
2102 item->u.am.request_from = request_from;
2103 item->u.am.flags = flags;
2106 mlog(0, "IGNORE HIGHER: %.*s\n", res->lockname.len,
2107 res->lockname.name);
2109 spin_lock(&dlm->work_lock);
2110 list_add_tail(&item->list, &dlm->work_list);
2111 spin_unlock(&dlm->work_lock);
2113 queue_work(dlm->dlm_worker, &dlm->dispatched_work);
2117 static void dlm_assert_master_worker(struct dlm_work_item *item, void *data)
2119 struct dlm_ctxt *dlm = data;
2121 struct dlm_lock_resource *res;
2122 unsigned long nodemap[BITS_TO_LONGS(O2NM_MAX_NODES)];
2129 res = item->u.am.lockres;
2130 ignore_higher = item->u.am.ignore_higher;
2131 request_from = item->u.am.request_from;
2132 flags = item->u.am.flags;
2134 spin_lock(&dlm->spinlock);
2135 memcpy(nodemap, dlm->domain_map, sizeof(nodemap));
2136 spin_unlock(&dlm->spinlock);
2138 clear_bit(dlm->node_num, nodemap);
2139 if (ignore_higher) {
2140 /* if is this just to clear up mles for nodes below
2141 * this node, do not send the message to the original
2142 * caller or any node number higher than this */
2143 clear_bit(request_from, nodemap);
2144 bit = dlm->node_num;
2146 bit = find_next_bit(nodemap, O2NM_MAX_NODES,
2148 if (bit >= O2NM_MAX_NODES)
2150 clear_bit(bit, nodemap);
2155 * If we're migrating this lock to someone else, we are no
2156 * longer allowed to assert out own mastery. OTOH, we need to
2157 * prevent migration from starting while we're still asserting
2158 * our dominance. The reserved ast delays migration.
2160 spin_lock(&res->spinlock);
2161 if (res->state & DLM_LOCK_RES_MIGRATING) {
2162 mlog(0, "Someone asked us to assert mastery, but we're "
2163 "in the middle of migration. Skipping assert, "
2164 "the new master will handle that.\n");
2165 spin_unlock(&res->spinlock);
2168 __dlm_lockres_reserve_ast(res);
2169 spin_unlock(&res->spinlock);
2171 /* this call now finishes out the nodemap
2172 * even if one or more nodes die */
2173 mlog(0, "worker about to master %.*s here, this=%u\n",
2174 res->lockname.len, res->lockname.name, dlm->node_num);
2175 ret = dlm_do_assert_master(dlm, res, nodemap, flags);
2177 /* no need to restart, we are done */
2178 if (!dlm_is_host_down(ret))
2182 /* Ok, we've asserted ourselves. Let's let migration start. */
2183 dlm_lockres_release_ast(dlm, res);
2186 dlm_lockres_drop_inflight_worker(dlm, res);
2188 dlm_lockres_put(res);
2190 mlog(0, "finished with dlm_assert_master_worker\n");
2193 /* SPECIAL CASE for the $RECOVERY lock used by the recovery thread.
2194 * We cannot wait for node recovery to complete to begin mastering this
2195 * lockres because this lockres is used to kick off recovery! ;-)
2196 * So, do a pre-check on all living nodes to see if any of those nodes
2197 * think that $RECOVERY is currently mastered by a dead node. If so,
2198 * we wait a short time to allow that node to get notified by its own
2199 * heartbeat stack, then check again. All $RECOVERY lock resources
2200 * mastered by dead nodes are purged when the hearbeat callback is
2201 * fired, so we can know for sure that it is safe to continue once
2202 * the node returns a live node or no node. */
2203 static int dlm_pre_master_reco_lockres(struct dlm_ctxt *dlm,
2204 struct dlm_lock_resource *res)
2206 struct dlm_node_iter iter;
2209 u8 master = DLM_LOCK_RES_OWNER_UNKNOWN;
2211 spin_lock(&dlm->spinlock);
2212 dlm_node_iter_init(dlm->domain_map, &iter);
2213 spin_unlock(&dlm->spinlock);
2215 while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2216 /* do not send to self */
2217 if (nodenum == dlm->node_num)
2219 ret = dlm_do_master_requery(dlm, res, nodenum, &master);
2222 if (!dlm_is_host_down(ret))
2224 /* host is down, so answer for that node would be
2225 * DLM_LOCK_RES_OWNER_UNKNOWN. continue. */
2229 if (master != DLM_LOCK_RES_OWNER_UNKNOWN) {
2230 /* check to see if this master is in the recovery map */
2231 spin_lock(&dlm->spinlock);
2232 if (test_bit(master, dlm->recovery_map)) {
2233 mlog(ML_NOTICE, "%s: node %u has not seen "
2234 "node %u go down yet, and thinks the "
2235 "dead node is mastering the recovery "
2236 "lock. must wait.\n", dlm->name,
2240 spin_unlock(&dlm->spinlock);
2241 mlog(0, "%s: reco lock master is %u\n", dlm->name,
2250 * DLM_DEREF_LOCKRES_MSG
2253 int dlm_drop_lockres_ref(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
2255 struct dlm_deref_lockres deref;
2257 const char *lockname;
2258 unsigned int namelen;
2260 lockname = res->lockname.name;
2261 namelen = res->lockname.len;
2262 BUG_ON(namelen > O2NM_MAX_NAME_LEN);
2264 memset(&deref, 0, sizeof(deref));
2265 deref.node_idx = dlm->node_num;
2266 deref.namelen = namelen;
2267 memcpy(deref.name, lockname, namelen);
2269 ret = o2net_send_message(DLM_DEREF_LOCKRES_MSG, dlm->key,
2270 &deref, sizeof(deref), res->owner, &r);
2272 mlog(ML_ERROR, "%s: res %.*s, error %d send DEREF to node %u\n",
2273 dlm->name, namelen, lockname, ret, res->owner);
2275 /* BAD. other node says I did not have a ref. */
2276 mlog(ML_ERROR, "%s: res %.*s, DEREF to node %u got %d\n",
2277 dlm->name, namelen, lockname, res->owner, r);
2278 dlm_print_one_lock_resource(res);
2284 int dlm_deref_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
2287 struct dlm_ctxt *dlm = data;
2288 struct dlm_deref_lockres *deref = (struct dlm_deref_lockres *)msg->buf;
2289 struct dlm_lock_resource *res = NULL;
2291 unsigned int namelen;
2295 struct dlm_work_item *item;
2303 namelen = deref->namelen;
2304 node = deref->node_idx;
2306 if (namelen > DLM_LOCKID_NAME_MAX) {
2307 mlog(ML_ERROR, "Invalid name length!");
2310 if (deref->node_idx >= O2NM_MAX_NODES) {
2311 mlog(ML_ERROR, "Invalid node number: %u\n", node);
2315 hash = dlm_lockid_hash(name, namelen);
2317 spin_lock(&dlm->spinlock);
2318 res = __dlm_lookup_lockres_full(dlm, name, namelen, hash);
2320 spin_unlock(&dlm->spinlock);
2321 mlog(ML_ERROR, "%s:%.*s: bad lockres name\n",
2322 dlm->name, namelen, name);
2325 spin_unlock(&dlm->spinlock);
2327 spin_lock(&res->spinlock);
2328 if (res->state & DLM_LOCK_RES_SETREF_INPROG)
2331 BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF);
2332 if (test_bit(node, res->refmap)) {
2333 dlm_lockres_clear_refmap_bit(dlm, res, node);
2337 spin_unlock(&res->spinlock);
2341 dlm_lockres_calc_usage(dlm, res);
2343 mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref "
2344 "but it is already dropped!\n", dlm->name,
2345 res->lockname.len, res->lockname.name, node);
2346 dlm_print_one_lock_resource(res);
2352 item = kzalloc(sizeof(*item), GFP_NOFS);
2359 dlm_init_work_item(dlm, item, dlm_deref_lockres_worker, NULL);
2360 item->u.dl.deref_res = res;
2361 item->u.dl.deref_node = node;
2363 spin_lock(&dlm->work_lock);
2364 list_add_tail(&item->list, &dlm->work_list);
2365 spin_unlock(&dlm->work_lock);
2367 queue_work(dlm->dlm_worker, &dlm->dispatched_work);
2372 dlm_lockres_put(res);
2378 static void dlm_deref_lockres_worker(struct dlm_work_item *item, void *data)
2380 struct dlm_ctxt *dlm;
2381 struct dlm_lock_resource *res;
2386 res = item->u.dl.deref_res;
2387 node = item->u.dl.deref_node;
2389 spin_lock(&res->spinlock);
2390 BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF);
2391 __dlm_wait_on_lockres_flags(res, DLM_LOCK_RES_SETREF_INPROG);
2392 if (test_bit(node, res->refmap)) {
2393 dlm_lockres_clear_refmap_bit(dlm, res, node);
2396 spin_unlock(&res->spinlock);
2399 mlog(0, "%s:%.*s node %u ref dropped in dispatch\n",
2400 dlm->name, res->lockname.len, res->lockname.name, node);
2401 dlm_lockres_calc_usage(dlm, res);
2403 mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref "
2404 "but it is already dropped!\n", dlm->name,
2405 res->lockname.len, res->lockname.name, node);
2406 dlm_print_one_lock_resource(res);
2409 dlm_lockres_put(res);
2413 * A migrateable resource is one that is :
2414 * 1. locally mastered, and,
2415 * 2. zero local locks, and,
2416 * 3. one or more non-local locks, or, one or more references
2417 * Returns 1 if yes, 0 if not.
2419 static int dlm_is_lockres_migrateable(struct dlm_ctxt *dlm,
2420 struct dlm_lock_resource *res)
2422 enum dlm_lockres_list idx;
2423 int nonlocal = 0, node_ref;
2424 struct list_head *queue;
2425 struct dlm_lock *lock;
2428 assert_spin_locked(&res->spinlock);
2430 /* delay migration when the lockres is in MIGRATING state */
2431 if (res->state & DLM_LOCK_RES_MIGRATING)
2434 /* delay migration when the lockres is in RECOCERING state */
2435 if (res->state & DLM_LOCK_RES_RECOVERING)
2438 if (res->owner != dlm->node_num)
2441 for (idx = DLM_GRANTED_LIST; idx <= DLM_BLOCKED_LIST; idx++) {
2442 queue = dlm_list_idx_to_ptr(res, idx);
2443 list_for_each_entry(lock, queue, list) {
2444 if (lock->ml.node != dlm->node_num) {
2448 cookie = be64_to_cpu(lock->ml.cookie);
2449 mlog(0, "%s: Not migrateable res %.*s, lock %u:%llu on "
2450 "%s list\n", dlm->name, res->lockname.len,
2452 dlm_get_lock_cookie_node(cookie),
2453 dlm_get_lock_cookie_seq(cookie),
2454 dlm_list_in_text(idx));
2460 node_ref = find_next_bit(res->refmap, O2NM_MAX_NODES, 0);
2461 if (node_ref >= O2NM_MAX_NODES)
2465 mlog(0, "%s: res %.*s, Migrateable\n", dlm->name, res->lockname.len,
2466 res->lockname.name);
2472 * DLM_MIGRATE_LOCKRES
2476 static int dlm_migrate_lockres(struct dlm_ctxt *dlm,
2477 struct dlm_lock_resource *res, u8 target)
2479 struct dlm_master_list_entry *mle = NULL;
2480 struct dlm_master_list_entry *oldmle = NULL;
2481 struct dlm_migratable_lockres *mres = NULL;
2484 unsigned int namelen;
2491 BUG_ON(target == O2NM_MAX_NODES);
2493 name = res->lockname.name;
2494 namelen = res->lockname.len;
2496 mlog(0, "%s: Migrating %.*s to node %u\n", dlm->name, namelen, name,
2499 /* preallocate up front. if this fails, abort */
2501 mres = (struct dlm_migratable_lockres *) __get_free_page(GFP_NOFS);
2507 mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
2515 * clear any existing master requests and
2516 * add the migration mle to the list
2518 spin_lock(&dlm->spinlock);
2519 spin_lock(&dlm->master_lock);
2520 ret = dlm_add_migration_mle(dlm, res, mle, &oldmle, name,
2521 namelen, target, dlm->node_num);
2522 /* get an extra reference on the mle.
2523 * otherwise the assert_master from the new
2524 * master will destroy this.
2526 dlm_get_mle_inuse(mle);
2527 spin_unlock(&dlm->master_lock);
2528 spin_unlock(&dlm->spinlock);
2530 if (ret == -EEXIST) {
2531 mlog(0, "another process is already migrating it\n");
2537 * set the MIGRATING flag and flush asts
2538 * if we fail after this we need to re-dirty the lockres
2540 if (dlm_mark_lockres_migrating(dlm, res, target) < 0) {
2541 mlog(ML_ERROR, "tried to migrate %.*s to %u, but "
2542 "the target went down.\n", res->lockname.len,
2543 res->lockname.name, target);
2544 spin_lock(&res->spinlock);
2545 res->state &= ~DLM_LOCK_RES_MIGRATING;
2547 spin_unlock(&res->spinlock);
2552 if (ret != -EEXIST && oldmle) {
2553 /* master is known, detach if not already detached */
2554 dlm_mle_detach_hb_events(dlm, oldmle);
2555 dlm_put_mle(oldmle);
2560 dlm_mle_detach_hb_events(dlm, mle);
2562 dlm_put_mle_inuse(mle);
2564 kmem_cache_free(dlm_mle_cache, mle);
2571 * at this point, we have a migration target, an mle
2572 * in the master list, and the MIGRATING flag set on
2576 /* now that remote nodes are spinning on the MIGRATING flag,
2577 * ensure that all assert_master work is flushed. */
2578 flush_workqueue(dlm->dlm_worker);
2580 /* notify new node and send all lock state */
2581 /* call send_one_lockres with migration flag.
2582 * this serves as notice to the target node that a
2583 * migration is starting. */
2584 ret = dlm_send_one_lockres(dlm, res, mres, target,
2585 DLM_MRES_MIGRATION);
2588 mlog(0, "migration to node %u failed with %d\n",
2590 /* migration failed, detach and clean up mle */
2591 dlm_mle_detach_hb_events(dlm, mle);
2593 dlm_put_mle_inuse(mle);
2594 spin_lock(&res->spinlock);
2595 res->state &= ~DLM_LOCK_RES_MIGRATING;
2597 spin_unlock(&res->spinlock);
2598 if (dlm_is_host_down(ret))
2599 dlm_wait_for_node_death(dlm, target,
2600 DLM_NODE_DEATH_WAIT_MAX);
2604 /* at this point, the target sends a message to all nodes,
2605 * (using dlm_do_migrate_request). this node is skipped since
2606 * we had to put an mle in the list to begin the process. this
2607 * node now waits for target to do an assert master. this node
2608 * will be the last one notified, ensuring that the migration
2609 * is complete everywhere. if the target dies while this is
2610 * going on, some nodes could potentially see the target as the
2611 * master, so it is important that my recovery finds the migration
2612 * mle and sets the master to UNKNOWN. */
2615 /* wait for new node to assert master */
2617 ret = wait_event_interruptible_timeout(mle->wq,
2618 (atomic_read(&mle->woken) == 1),
2619 msecs_to_jiffies(5000));
2622 if (atomic_read(&mle->woken) == 1 ||
2623 res->owner == target)
2626 mlog(0, "%s:%.*s: timed out during migration\n",
2627 dlm->name, res->lockname.len, res->lockname.name);
2628 /* avoid hang during shutdown when migrating lockres
2629 * to a node which also goes down */
2630 if (dlm_is_node_dead(dlm, target)) {
2631 mlog(0, "%s:%.*s: expected migration "
2632 "target %u is no longer up, restarting\n",
2633 dlm->name, res->lockname.len,
2634 res->lockname.name, target);
2636 /* migration failed, detach and clean up mle */
2637 dlm_mle_detach_hb_events(dlm, mle);
2639 dlm_put_mle_inuse(mle);
2640 spin_lock(&res->spinlock);
2641 res->state &= ~DLM_LOCK_RES_MIGRATING;
2643 spin_unlock(&res->spinlock);
2647 mlog(0, "%s:%.*s: caught signal during migration\n",
2648 dlm->name, res->lockname.len, res->lockname.name);
2651 /* all done, set the owner, clear the flag */
2652 spin_lock(&res->spinlock);
2653 dlm_set_lockres_owner(dlm, res, target);
2654 res->state &= ~DLM_LOCK_RES_MIGRATING;
2655 dlm_remove_nonlocal_locks(dlm, res);
2656 spin_unlock(&res->spinlock);
2659 /* master is known, detach if not already detached */
2660 dlm_mle_detach_hb_events(dlm, mle);
2661 dlm_put_mle_inuse(mle);
2664 dlm_lockres_calc_usage(dlm, res);
2667 /* re-dirty the lockres if we failed */
2669 dlm_kick_thread(dlm, res);
2671 /* wake up waiters if the MIGRATING flag got set
2672 * but migration failed */
2677 free_page((unsigned long)mres);
2681 mlog(0, "%s: Migrating %.*s to %u, returns %d\n", dlm->name, namelen,
2686 #define DLM_MIGRATION_RETRY_MS 100
2689 * Should be called only after beginning the domain leave process.
2690 * There should not be any remaining locks on nonlocal lock resources,
2691 * and there should be no local locks left on locally mastered resources.
2693 * Called with the dlm spinlock held, may drop it to do migration, but
2694 * will re-acquire before exit.
2696 * Returns: 1 if dlm->spinlock was dropped/retaken, 0 if never dropped
2698 int dlm_empty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
2701 int lock_dropped = 0;
2702 u8 target = O2NM_MAX_NODES;
2704 assert_spin_locked(&dlm->spinlock);
2706 spin_lock(&res->spinlock);
2707 if (dlm_is_lockres_migrateable(dlm, res))
2708 target = dlm_pick_migration_target(dlm, res);
2709 spin_unlock(&res->spinlock);
2711 if (target == O2NM_MAX_NODES)
2714 /* Wheee! Migrate lockres here! Will sleep so drop spinlock. */
2715 spin_unlock(&dlm->spinlock);
2717 ret = dlm_migrate_lockres(dlm, res, target);
2719 mlog(0, "%s: res %.*s, Migrate to node %u failed with %d\n",
2720 dlm->name, res->lockname.len, res->lockname.name,
2722 spin_lock(&dlm->spinlock);
2724 return lock_dropped;
2727 int dlm_lock_basts_flushed(struct dlm_ctxt *dlm, struct dlm_lock *lock)
2730 spin_lock(&dlm->ast_lock);
2731 spin_lock(&lock->spinlock);
2732 ret = (list_empty(&lock->bast_list) && !lock->bast_pending);
2733 spin_unlock(&lock->spinlock);
2734 spin_unlock(&dlm->ast_lock);
2738 static int dlm_migration_can_proceed(struct dlm_ctxt *dlm,
2739 struct dlm_lock_resource *res,
2743 spin_lock(&res->spinlock);
2744 can_proceed = !!(res->state & DLM_LOCK_RES_MIGRATING);
2745 spin_unlock(&res->spinlock);
2747 /* target has died, so make the caller break out of the
2748 * wait_event, but caller must recheck the domain_map */
2749 spin_lock(&dlm->spinlock);
2750 if (!test_bit(mig_target, dlm->domain_map))
2752 spin_unlock(&dlm->spinlock);
2756 static int dlm_lockres_is_dirty(struct dlm_ctxt *dlm,
2757 struct dlm_lock_resource *res)
2760 spin_lock(&res->spinlock);
2761 ret = !!(res->state & DLM_LOCK_RES_DIRTY);
2762 spin_unlock(&res->spinlock);
2767 static int dlm_mark_lockres_migrating(struct dlm_ctxt *dlm,
2768 struct dlm_lock_resource *res,
2773 mlog(0, "dlm_mark_lockres_migrating: %.*s, from %u to %u\n",
2774 res->lockname.len, res->lockname.name, dlm->node_num,
2776 /* need to set MIGRATING flag on lockres. this is done by
2777 * ensuring that all asts have been flushed for this lockres. */
2778 spin_lock(&res->spinlock);
2779 BUG_ON(res->migration_pending);
2780 res->migration_pending = 1;
2781 /* strategy is to reserve an extra ast then release
2782 * it below, letting the release do all of the work */
2783 __dlm_lockres_reserve_ast(res);
2784 spin_unlock(&res->spinlock);
2786 /* now flush all the pending asts */
2787 dlm_kick_thread(dlm, res);
2788 /* before waiting on DIRTY, block processes which may
2789 * try to dirty the lockres before MIGRATING is set */
2790 spin_lock(&res->spinlock);
2791 BUG_ON(res->state & DLM_LOCK_RES_BLOCK_DIRTY);
2792 res->state |= DLM_LOCK_RES_BLOCK_DIRTY;
2793 spin_unlock(&res->spinlock);
2794 /* now wait on any pending asts and the DIRTY state */
2795 wait_event(dlm->ast_wq, !dlm_lockres_is_dirty(dlm, res));
2796 dlm_lockres_release_ast(dlm, res);
2798 mlog(0, "about to wait on migration_wq, dirty=%s\n",
2799 res->state & DLM_LOCK_RES_DIRTY ? "yes" : "no");
2800 /* if the extra ref we just put was the final one, this
2801 * will pass thru immediately. otherwise, we need to wait
2802 * for the last ast to finish. */
2804 ret = wait_event_interruptible_timeout(dlm->migration_wq,
2805 dlm_migration_can_proceed(dlm, res, target),
2806 msecs_to_jiffies(1000));
2808 mlog(0, "woken again: migrating? %s, dead? %s\n",
2809 res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no",
2810 test_bit(target, dlm->domain_map) ? "no":"yes");
2812 mlog(0, "all is well: migrating? %s, dead? %s\n",
2813 res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no",
2814 test_bit(target, dlm->domain_map) ? "no":"yes");
2816 if (!dlm_migration_can_proceed(dlm, res, target)) {
2817 mlog(0, "trying again...\n");
2822 /* did the target go down or die? */
2823 spin_lock(&dlm->spinlock);
2824 if (!test_bit(target, dlm->domain_map)) {
2825 mlog(ML_ERROR, "aha. migration target %u just went down\n",
2829 spin_unlock(&dlm->spinlock);
2832 * if target is down, we need to clear DLM_LOCK_RES_BLOCK_DIRTY for
2833 * another try; otherwise, we are sure the MIGRATING state is there,
2834 * drop the unneded state which blocked threads trying to DIRTY
2836 spin_lock(&res->spinlock);
2837 BUG_ON(!(res->state & DLM_LOCK_RES_BLOCK_DIRTY));
2838 res->state &= ~DLM_LOCK_RES_BLOCK_DIRTY;
2840 BUG_ON(!(res->state & DLM_LOCK_RES_MIGRATING));
2842 res->migration_pending = 0;
2843 spin_unlock(&res->spinlock);
2848 * o the DLM_LOCK_RES_MIGRATING flag is set if target not down
2849 * o there are no pending asts on this lockres
2850 * o all processes trying to reserve an ast on this
2851 * lockres must wait for the MIGRATING flag to clear
2856 /* last step in the migration process.
2857 * original master calls this to free all of the dlm_lock
2858 * structures that used to be for other nodes. */
2859 static void dlm_remove_nonlocal_locks(struct dlm_ctxt *dlm,
2860 struct dlm_lock_resource *res)
2862 struct list_head *queue = &res->granted;
2864 struct dlm_lock *lock, *next;
2866 assert_spin_locked(&res->spinlock);
2868 BUG_ON(res->owner == dlm->node_num);
2870 for (i=0; i<3; i++) {
2871 list_for_each_entry_safe(lock, next, queue, list) {
2872 if (lock->ml.node != dlm->node_num) {
2873 mlog(0, "putting lock for node %u\n",
2875 /* be extra careful */
2876 BUG_ON(!list_empty(&lock->ast_list));
2877 BUG_ON(!list_empty(&lock->bast_list));
2878 BUG_ON(lock->ast_pending);
2879 BUG_ON(lock->bast_pending);
2880 dlm_lockres_clear_refmap_bit(dlm, res,
2882 list_del_init(&lock->list);
2884 /* In a normal unlock, we would have added a
2885 * DLM_UNLOCK_FREE_LOCK action. Force it. */
2893 bit = find_next_bit(res->refmap, O2NM_MAX_NODES, bit);
2894 if (bit >= O2NM_MAX_NODES)
2896 /* do not clear the local node reference, if there is a
2897 * process holding this, let it drop the ref itself */
2898 if (bit != dlm->node_num) {
2899 mlog(0, "%s:%.*s: node %u had a ref to this "
2900 "migrating lockres, clearing\n", dlm->name,
2901 res->lockname.len, res->lockname.name, bit);
2902 dlm_lockres_clear_refmap_bit(dlm, res, bit);
2909 * Pick a node to migrate the lock resource to. This function selects a
2910 * potential target based first on the locks and then on refmap. It skips
2911 * nodes that are in the process of exiting the domain.
2913 static u8 dlm_pick_migration_target(struct dlm_ctxt *dlm,
2914 struct dlm_lock_resource *res)
2916 enum dlm_lockres_list idx;
2917 struct list_head *queue = &res->granted;
2918 struct dlm_lock *lock;
2920 u8 nodenum = O2NM_MAX_NODES;
2922 assert_spin_locked(&dlm->spinlock);
2923 assert_spin_locked(&res->spinlock);
2925 /* Go through all the locks */
2926 for (idx = DLM_GRANTED_LIST; idx <= DLM_BLOCKED_LIST; idx++) {
2927 queue = dlm_list_idx_to_ptr(res, idx);
2928 list_for_each_entry(lock, queue, list) {
2929 if (lock->ml.node == dlm->node_num)
2931 if (test_bit(lock->ml.node, dlm->exit_domain_map))
2933 nodenum = lock->ml.node;
2938 /* Go thru the refmap */
2941 noderef = find_next_bit(res->refmap, O2NM_MAX_NODES,
2943 if (noderef >= O2NM_MAX_NODES)
2945 if (noderef == dlm->node_num)
2947 if (test_bit(noderef, dlm->exit_domain_map))
2957 /* this is called by the new master once all lockres
2958 * data has been received */
2959 static int dlm_do_migrate_request(struct dlm_ctxt *dlm,
2960 struct dlm_lock_resource *res,
2961 u8 master, u8 new_master,
2962 struct dlm_node_iter *iter)
2964 struct dlm_migrate_request migrate;
2965 int ret, skip, status = 0;
2968 memset(&migrate, 0, sizeof(migrate));
2969 migrate.namelen = res->lockname.len;
2970 memcpy(migrate.name, res->lockname.name, migrate.namelen);
2971 migrate.new_master = new_master;
2972 migrate.master = master;
2976 /* send message to all nodes, except the master and myself */
2977 while ((nodenum = dlm_node_iter_next(iter)) >= 0) {
2978 if (nodenum == master ||
2979 nodenum == new_master)
2982 /* We could race exit domain. If exited, skip. */
2983 spin_lock(&dlm->spinlock);
2984 skip = (!test_bit(nodenum, dlm->domain_map));
2985 spin_unlock(&dlm->spinlock);
2987 clear_bit(nodenum, iter->node_map);
2991 ret = o2net_send_message(DLM_MIGRATE_REQUEST_MSG, dlm->key,
2992 &migrate, sizeof(migrate), nodenum,
2995 mlog(ML_ERROR, "%s: res %.*s, Error %d send "
2996 "MIGRATE_REQUEST to node %u\n", dlm->name,
2997 migrate.namelen, migrate.name, ret, nodenum);
2998 if (!dlm_is_host_down(ret)) {
2999 mlog(ML_ERROR, "unhandled error=%d!\n", ret);
3002 clear_bit(nodenum, iter->node_map);
3004 } else if (status < 0) {
3005 mlog(0, "migrate request (node %u) returned %d!\n",
3008 } else if (status == DLM_MIGRATE_RESPONSE_MASTERY_REF) {
3009 /* during the migration request we short-circuited
3010 * the mastery of the lockres. make sure we have
3011 * a mastery ref for nodenum */
3012 mlog(0, "%s:%.*s: need ref for node %u\n",
3013 dlm->name, res->lockname.len, res->lockname.name,
3015 spin_lock(&res->spinlock);
3016 dlm_lockres_set_refmap_bit(dlm, res, nodenum);
3017 spin_unlock(&res->spinlock);
3024 mlog(0, "returning ret=%d\n", ret);
3029 /* if there is an existing mle for this lockres, we now know who the master is.
3030 * (the one who sent us *this* message) we can clear it up right away.
3031 * since the process that put the mle on the list still has a reference to it,
3032 * we can unhash it now, set the master and wake the process. as a result,
3033 * we will have no mle in the list to start with. now we can add an mle for
3034 * the migration and this should be the only one found for those scanning the
3036 int dlm_migrate_request_handler(struct o2net_msg *msg, u32 len, void *data,
3039 struct dlm_ctxt *dlm = data;
3040 struct dlm_lock_resource *res = NULL;
3041 struct dlm_migrate_request *migrate = (struct dlm_migrate_request *) msg->buf;
3042 struct dlm_master_list_entry *mle = NULL, *oldmle = NULL;
3044 unsigned int namelen, hash;
3050 name = migrate->name;
3051 namelen = migrate->namelen;
3052 hash = dlm_lockid_hash(name, namelen);
3054 /* preallocate.. if this fails, abort */
3055 mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
3062 /* check for pre-existing lock */
3063 spin_lock(&dlm->spinlock);
3064 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
3066 spin_lock(&res->spinlock);
3067 if (res->state & DLM_LOCK_RES_RECOVERING) {
3068 /* if all is working ok, this can only mean that we got
3069 * a migrate request from a node that we now see as
3070 * dead. what can we do here? drop it to the floor? */
3071 spin_unlock(&res->spinlock);
3072 mlog(ML_ERROR, "Got a migrate request, but the "
3073 "lockres is marked as recovering!");
3074 kmem_cache_free(dlm_mle_cache, mle);
3075 ret = -EINVAL; /* need a better solution */
3078 res->state |= DLM_LOCK_RES_MIGRATING;
3079 spin_unlock(&res->spinlock);
3082 spin_lock(&dlm->master_lock);
3083 /* ignore status. only nonzero status would BUG. */
3084 ret = dlm_add_migration_mle(dlm, res, mle, &oldmle,
3086 migrate->new_master,
3089 spin_unlock(&dlm->master_lock);
3091 spin_unlock(&dlm->spinlock);
3094 /* master is known, detach if not already detached */
3095 dlm_mle_detach_hb_events(dlm, oldmle);
3096 dlm_put_mle(oldmle);
3100 dlm_lockres_put(res);
3106 /* must be holding dlm->spinlock and dlm->master_lock
3107 * when adding a migration mle, we can clear any other mles
3108 * in the master list because we know with certainty that
3109 * the master is "master". so we remove any old mle from
3110 * the list after setting it's master field, and then add
3111 * the new migration mle. this way we can hold with the rule
3112 * of having only one mle for a given lock name at all times. */
3113 static int dlm_add_migration_mle(struct dlm_ctxt *dlm,
3114 struct dlm_lock_resource *res,
3115 struct dlm_master_list_entry *mle,
3116 struct dlm_master_list_entry **oldmle,
3117 const char *name, unsigned int namelen,
3118 u8 new_master, u8 master)
3125 assert_spin_locked(&dlm->spinlock);
3126 assert_spin_locked(&dlm->master_lock);
3128 /* caller is responsible for any ref taken here on oldmle */
3129 found = dlm_find_mle(dlm, oldmle, (char *)name, namelen);
3131 struct dlm_master_list_entry *tmp = *oldmle;
3132 spin_lock(&tmp->spinlock);
3133 if (tmp->type == DLM_MLE_MIGRATION) {
3134 if (master == dlm->node_num) {
3135 /* ah another process raced me to it */
3136 mlog(0, "tried to migrate %.*s, but some "
3137 "process beat me to it\n",
3139 spin_unlock(&tmp->spinlock);
3142 /* bad. 2 NODES are trying to migrate! */
3143 mlog(ML_ERROR, "migration error mle: "
3144 "master=%u new_master=%u // request: "
3145 "master=%u new_master=%u // "
3147 tmp->master, tmp->new_master,
3153 /* this is essentially what assert_master does */
3154 tmp->master = master;
3155 atomic_set(&tmp->woken, 1);
3157 /* remove it so that only one mle will be found */
3158 __dlm_unlink_mle(dlm, tmp);
3159 __dlm_mle_detach_hb_events(dlm, tmp);
3160 if (tmp->type == DLM_MLE_MASTER) {
3161 ret = DLM_MIGRATE_RESPONSE_MASTERY_REF;
3162 mlog(0, "%s:%.*s: master=%u, newmaster=%u, "
3163 "telling master to get ref "
3164 "for cleared out mle during "
3165 "migration\n", dlm->name,
3166 namelen, name, master,
3170 spin_unlock(&tmp->spinlock);
3173 /* now add a migration mle to the tail of the list */
3174 dlm_init_mle(mle, DLM_MLE_MIGRATION, dlm, res, name, namelen);
3175 mle->new_master = new_master;
3176 /* the new master will be sending an assert master for this.
3177 * at that point we will get the refmap reference */
3178 mle->master = master;
3179 /* do this for consistency with other mle types */
3180 set_bit(new_master, mle->maybe_map);
3181 __dlm_insert_mle(dlm, mle);
3187 * Sets the owner of the lockres, associated to the mle, to UNKNOWN
3189 static struct dlm_lock_resource *dlm_reset_mleres_owner(struct dlm_ctxt *dlm,
3190 struct dlm_master_list_entry *mle)
3192 struct dlm_lock_resource *res;
3194 /* Find the lockres associated to the mle and set its owner to UNK */
3195 res = __dlm_lookup_lockres(dlm, mle->mname, mle->mnamelen,
3198 spin_unlock(&dlm->master_lock);
3200 /* move lockres onto recovery list */
3201 spin_lock(&res->spinlock);
3202 dlm_set_lockres_owner(dlm, res, DLM_LOCK_RES_OWNER_UNKNOWN);
3203 dlm_move_lockres_to_recovery_list(dlm, res);
3204 spin_unlock(&res->spinlock);
3205 dlm_lockres_put(res);
3207 /* about to get rid of mle, detach from heartbeat */
3208 __dlm_mle_detach_hb_events(dlm, mle);
3211 spin_lock(&dlm->master_lock);
3213 spin_unlock(&dlm->master_lock);
3219 static void dlm_clean_migration_mle(struct dlm_ctxt *dlm,
3220 struct dlm_master_list_entry *mle)
3222 __dlm_mle_detach_hb_events(dlm, mle);
3224 spin_lock(&mle->spinlock);
3225 __dlm_unlink_mle(dlm, mle);
3226 atomic_set(&mle->woken, 1);
3227 spin_unlock(&mle->spinlock);
3232 static void dlm_clean_block_mle(struct dlm_ctxt *dlm,
3233 struct dlm_master_list_entry *mle, u8 dead_node)
3237 BUG_ON(mle->type != DLM_MLE_BLOCK);
3239 spin_lock(&mle->spinlock);
3240 bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0);
3241 if (bit != dead_node) {
3242 mlog(0, "mle found, but dead node %u would not have been "
3243 "master\n", dead_node);
3244 spin_unlock(&mle->spinlock);
3246 /* Must drop the refcount by one since the assert_master will
3247 * never arrive. This may result in the mle being unlinked and
3248 * freed, but there may still be a process waiting in the
3249 * dlmlock path which is fine. */
3250 mlog(0, "node %u was expected master\n", dead_node);
3251 atomic_set(&mle->woken, 1);
3252 spin_unlock(&mle->spinlock);
3255 /* Do not need events any longer, so detach from heartbeat */
3256 __dlm_mle_detach_hb_events(dlm, mle);
3261 void dlm_clean_master_list(struct dlm_ctxt *dlm, u8 dead_node)
3263 struct dlm_master_list_entry *mle;
3264 struct dlm_lock_resource *res;
3265 struct hlist_head *bucket;
3266 struct hlist_node *tmp;
3269 mlog(0, "dlm=%s, dead node=%u\n", dlm->name, dead_node);
3271 assert_spin_locked(&dlm->spinlock);
3273 /* clean the master list */
3274 spin_lock(&dlm->master_lock);
3275 for (i = 0; i < DLM_HASH_BUCKETS; i++) {
3276 bucket = dlm_master_hash(dlm, i);
3277 hlist_for_each_entry_safe(mle, tmp, bucket, master_hash_node) {
3278 BUG_ON(mle->type != DLM_MLE_BLOCK &&
3279 mle->type != DLM_MLE_MASTER &&
3280 mle->type != DLM_MLE_MIGRATION);
3282 /* MASTER mles are initiated locally. The waiting
3283 * process will notice the node map change shortly.
3284 * Let that happen as normal. */
3285 if (mle->type == DLM_MLE_MASTER)
3288 /* BLOCK mles are initiated by other nodes. Need to
3289 * clean up if the dead node would have been the
3291 if (mle->type == DLM_MLE_BLOCK) {
3292 dlm_clean_block_mle(dlm, mle, dead_node);
3296 /* Everything else is a MIGRATION mle */
3298 /* The rule for MIGRATION mles is that the master
3299 * becomes UNKNOWN if *either* the original or the new
3300 * master dies. All UNKNOWN lockres' are sent to
3301 * whichever node becomes the recovery master. The new
3302 * master is responsible for determining if there is
3303 * still a master for this lockres, or if he needs to
3304 * take over mastery. Either way, this node should
3305 * expect another message to resolve this. */
3307 if (mle->master != dead_node &&
3308 mle->new_master != dead_node)
3311 if (mle->new_master == dead_node && mle->inuse) {
3312 mlog(ML_NOTICE, "%s: target %u died during "
3313 "migration from %u, the MLE is "
3314 "still keep used, ignore it!\n",
3315 dlm->name, dead_node,
3320 /* If we have reached this point, this mle needs to be
3321 * removed from the list and freed. */
3322 dlm_clean_migration_mle(dlm, mle);
3324 mlog(0, "%s: node %u died during migration from "
3325 "%u to %u!\n", dlm->name, dead_node, mle->master,
3328 /* If we find a lockres associated with the mle, we've
3329 * hit this rare case that messes up our lock ordering.
3330 * If so, we need to drop the master lock so that we can
3331 * take the lockres lock, meaning that we will have to
3332 * restart from the head of list. */
3333 res = dlm_reset_mleres_owner(dlm, mle);
3338 /* This may be the last reference */
3342 spin_unlock(&dlm->master_lock);
3345 int dlm_finish_migration(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
3348 struct dlm_node_iter iter;
3351 spin_lock(&dlm->spinlock);
3352 dlm_node_iter_init(dlm->domain_map, &iter);
3353 clear_bit(old_master, iter.node_map);
3354 clear_bit(dlm->node_num, iter.node_map);
3355 spin_unlock(&dlm->spinlock);
3357 /* ownership of the lockres is changing. account for the
3358 * mastery reference here since old_master will briefly have
3359 * a reference after the migration completes */
3360 spin_lock(&res->spinlock);
3361 dlm_lockres_set_refmap_bit(dlm, res, old_master);
3362 spin_unlock(&res->spinlock);
3364 mlog(0, "now time to do a migrate request to other nodes\n");
3365 ret = dlm_do_migrate_request(dlm, res, old_master,
3366 dlm->node_num, &iter);
3372 mlog(0, "doing assert master of %.*s to all except the original node\n",
3373 res->lockname.len, res->lockname.name);
3374 /* this call now finishes out the nodemap
3375 * even if one or more nodes die */
3376 ret = dlm_do_assert_master(dlm, res, iter.node_map,
3377 DLM_ASSERT_MASTER_FINISH_MIGRATION);
3379 /* no longer need to retry. all living nodes contacted. */
3384 memset(iter.node_map, 0, sizeof(iter.node_map));
3385 set_bit(old_master, iter.node_map);
3386 mlog(0, "doing assert master of %.*s back to %u\n",
3387 res->lockname.len, res->lockname.name, old_master);
3388 ret = dlm_do_assert_master(dlm, res, iter.node_map,
3389 DLM_ASSERT_MASTER_FINISH_MIGRATION);
3391 mlog(0, "assert master to original master failed "
3393 /* the only nonzero status here would be because of
3394 * a dead original node. we're done. */
3398 /* all done, set the owner, clear the flag */
3399 spin_lock(&res->spinlock);
3400 dlm_set_lockres_owner(dlm, res, dlm->node_num);
3401 res->state &= ~DLM_LOCK_RES_MIGRATING;
3402 spin_unlock(&res->spinlock);
3403 /* re-dirty it on the new master */
3404 dlm_kick_thread(dlm, res);
3411 * LOCKRES AST REFCOUNT
3412 * this is integral to migration
3415 /* for future intent to call an ast, reserve one ahead of time.
3416 * this should be called only after waiting on the lockres
3417 * with dlm_wait_on_lockres, and while still holding the
3418 * spinlock after the call. */
3419 void __dlm_lockres_reserve_ast(struct dlm_lock_resource *res)
3421 assert_spin_locked(&res->spinlock);
3422 if (res->state & DLM_LOCK_RES_MIGRATING) {
3423 __dlm_print_one_lock_resource(res);
3425 BUG_ON(res->state & DLM_LOCK_RES_MIGRATING);
3427 atomic_inc(&res->asts_reserved);
3431 * used to drop the reserved ast, either because it went unused,
3432 * or because the ast/bast was actually called.
3434 * also, if there is a pending migration on this lockres,
3435 * and this was the last pending ast on the lockres,
3436 * atomically set the MIGRATING flag before we drop the lock.
3437 * this is how we ensure that migration can proceed with no
3438 * asts in progress. note that it is ok if the state of the
3439 * queues is such that a lock should be granted in the future
3440 * or that a bast should be fired, because the new master will
3441 * shuffle the lists on this lockres as soon as it is migrated.
3443 void dlm_lockres_release_ast(struct dlm_ctxt *dlm,
3444 struct dlm_lock_resource *res)
3446 if (!atomic_dec_and_lock(&res->asts_reserved, &res->spinlock))
3449 if (!res->migration_pending) {
3450 spin_unlock(&res->spinlock);
3454 BUG_ON(res->state & DLM_LOCK_RES_MIGRATING);
3455 res->migration_pending = 0;
3456 res->state |= DLM_LOCK_RES_MIGRATING;
3457 spin_unlock(&res->spinlock);
3459 wake_up(&dlm->migration_wq);
3462 void dlm_force_free_mles(struct dlm_ctxt *dlm)
3465 struct hlist_head *bucket;
3466 struct dlm_master_list_entry *mle;
3467 struct hlist_node *tmp;
3470 * We notified all other nodes that we are exiting the domain and
3471 * marked the dlm state to DLM_CTXT_LEAVING. If any mles are still
3472 * around we force free them and wake any processes that are waiting
3475 spin_lock(&dlm->spinlock);
3476 spin_lock(&dlm->master_lock);
3478 BUG_ON(dlm->dlm_state != DLM_CTXT_LEAVING);
3479 BUG_ON((find_next_bit(dlm->domain_map, O2NM_MAX_NODES, 0) < O2NM_MAX_NODES));
3481 for (i = 0; i < DLM_HASH_BUCKETS; i++) {
3482 bucket = dlm_master_hash(dlm, i);
3483 hlist_for_each_entry_safe(mle, tmp, bucket, master_hash_node) {
3484 if (mle->type != DLM_MLE_BLOCK) {
3485 mlog(ML_ERROR, "bad mle: %p\n", mle);
3486 dlm_print_one_mle(mle);
3488 atomic_set(&mle->woken, 1);
3491 __dlm_unlink_mle(dlm, mle);
3492 __dlm_mle_detach_hb_events(dlm, mle);
3496 spin_unlock(&dlm->master_lock);
3497 spin_unlock(&dlm->spinlock);