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 = NULL;
86 static struct kmem_cache *dlm_lockname_cache = NULL;
87 static struct kmem_cache *dlm_mle_cache = NULL;
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;
345 struct hlist_node *list;
348 assert_spin_locked(&dlm->master_lock);
350 hash = dlm_lockid_hash(name, namelen);
351 bucket = dlm_master_hash(dlm, hash);
352 hlist_for_each(list, bucket) {
353 tmpmle = hlist_entry(list, struct dlm_master_list_entry,
355 if (!dlm_mle_equal(dlm, tmpmle, name, namelen))
364 void dlm_hb_event_notify_attached(struct dlm_ctxt *dlm, int idx, int node_up)
366 struct dlm_master_list_entry *mle;
368 assert_spin_locked(&dlm->spinlock);
370 list_for_each_entry(mle, &dlm->mle_hb_events, hb_events) {
372 dlm_mle_node_up(dlm, mle, NULL, idx);
374 dlm_mle_node_down(dlm, mle, NULL, idx);
378 static void dlm_mle_node_down(struct dlm_ctxt *dlm,
379 struct dlm_master_list_entry *mle,
380 struct o2nm_node *node, int idx)
382 spin_lock(&mle->spinlock);
384 if (!test_bit(idx, mle->node_map))
385 mlog(0, "node %u already removed from nodemap!\n", idx);
387 clear_bit(idx, mle->node_map);
389 spin_unlock(&mle->spinlock);
392 static void dlm_mle_node_up(struct dlm_ctxt *dlm,
393 struct dlm_master_list_entry *mle,
394 struct o2nm_node *node, int idx)
396 spin_lock(&mle->spinlock);
398 if (test_bit(idx, mle->node_map))
399 mlog(0, "node %u already in node map!\n", idx);
401 set_bit(idx, mle->node_map);
403 spin_unlock(&mle->spinlock);
407 int dlm_init_mle_cache(void)
409 dlm_mle_cache = kmem_cache_create("o2dlm_mle",
410 sizeof(struct dlm_master_list_entry),
411 0, SLAB_HWCACHE_ALIGN,
413 if (dlm_mle_cache == NULL)
418 void dlm_destroy_mle_cache(void)
421 kmem_cache_destroy(dlm_mle_cache);
424 static void dlm_mle_release(struct kref *kref)
426 struct dlm_master_list_entry *mle;
427 struct dlm_ctxt *dlm;
431 mle = container_of(kref, struct dlm_master_list_entry, mle_refs);
434 assert_spin_locked(&dlm->spinlock);
435 assert_spin_locked(&dlm->master_lock);
437 mlog(0, "Releasing mle for %.*s, type %d\n", mle->mnamelen, mle->mname,
440 /* remove from list if not already */
441 __dlm_unlink_mle(dlm, mle);
443 /* detach the mle from the domain node up/down events */
444 __dlm_mle_detach_hb_events(dlm, mle);
446 atomic_dec(&dlm->mle_cur_count[mle->type]);
448 /* NOTE: kfree under spinlock here.
449 * if this is bad, we can move this to a freelist. */
450 kmem_cache_free(dlm_mle_cache, mle);
455 * LOCK RESOURCE FUNCTIONS
458 int dlm_init_master_caches(void)
460 dlm_lockres_cache = kmem_cache_create("o2dlm_lockres",
461 sizeof(struct dlm_lock_resource),
462 0, SLAB_HWCACHE_ALIGN, NULL);
463 if (!dlm_lockres_cache)
466 dlm_lockname_cache = kmem_cache_create("o2dlm_lockname",
467 DLM_LOCKID_NAME_MAX, 0,
468 SLAB_HWCACHE_ALIGN, NULL);
469 if (!dlm_lockname_cache)
474 dlm_destroy_master_caches();
478 void dlm_destroy_master_caches(void)
480 if (dlm_lockname_cache)
481 kmem_cache_destroy(dlm_lockname_cache);
483 if (dlm_lockres_cache)
484 kmem_cache_destroy(dlm_lockres_cache);
487 static void dlm_lockres_release(struct kref *kref)
489 struct dlm_lock_resource *res;
490 struct dlm_ctxt *dlm;
492 res = container_of(kref, struct dlm_lock_resource, refs);
495 /* This should not happen -- all lockres' have a name
496 * associated with them at init time. */
497 BUG_ON(!res->lockname.name);
499 mlog(0, "destroying lockres %.*s\n", res->lockname.len,
502 spin_lock(&dlm->track_lock);
503 if (!list_empty(&res->tracking))
504 list_del_init(&res->tracking);
506 mlog(ML_ERROR, "Resource %.*s not on the Tracking list\n",
507 res->lockname.len, res->lockname.name);
508 dlm_print_one_lock_resource(res);
510 spin_unlock(&dlm->track_lock);
512 atomic_dec(&dlm->res_cur_count);
516 if (!hlist_unhashed(&res->hash_node) ||
517 !list_empty(&res->granted) ||
518 !list_empty(&res->converting) ||
519 !list_empty(&res->blocked) ||
520 !list_empty(&res->dirty) ||
521 !list_empty(&res->recovering) ||
522 !list_empty(&res->purge)) {
524 "Going to BUG for resource %.*s."
525 " We're on a list! [%c%c%c%c%c%c%c]\n",
526 res->lockname.len, res->lockname.name,
527 !hlist_unhashed(&res->hash_node) ? 'H' : ' ',
528 !list_empty(&res->granted) ? 'G' : ' ',
529 !list_empty(&res->converting) ? 'C' : ' ',
530 !list_empty(&res->blocked) ? 'B' : ' ',
531 !list_empty(&res->dirty) ? 'D' : ' ',
532 !list_empty(&res->recovering) ? 'R' : ' ',
533 !list_empty(&res->purge) ? 'P' : ' ');
535 dlm_print_one_lock_resource(res);
538 /* By the time we're ready to blow this guy away, we shouldn't
539 * be on any lists. */
540 BUG_ON(!hlist_unhashed(&res->hash_node));
541 BUG_ON(!list_empty(&res->granted));
542 BUG_ON(!list_empty(&res->converting));
543 BUG_ON(!list_empty(&res->blocked));
544 BUG_ON(!list_empty(&res->dirty));
545 BUG_ON(!list_empty(&res->recovering));
546 BUG_ON(!list_empty(&res->purge));
548 kmem_cache_free(dlm_lockname_cache, (void *)res->lockname.name);
550 kmem_cache_free(dlm_lockres_cache, res);
553 void dlm_lockres_put(struct dlm_lock_resource *res)
555 kref_put(&res->refs, dlm_lockres_release);
558 static void dlm_init_lockres(struct dlm_ctxt *dlm,
559 struct dlm_lock_resource *res,
560 const char *name, unsigned int namelen)
564 /* If we memset here, we lose our reference to the kmalloc'd
565 * res->lockname.name, so be sure to init every field
568 qname = (char *) res->lockname.name;
569 memcpy(qname, name, namelen);
571 res->lockname.len = namelen;
572 res->lockname.hash = dlm_lockid_hash(name, namelen);
574 init_waitqueue_head(&res->wq);
575 spin_lock_init(&res->spinlock);
576 INIT_HLIST_NODE(&res->hash_node);
577 INIT_LIST_HEAD(&res->granted);
578 INIT_LIST_HEAD(&res->converting);
579 INIT_LIST_HEAD(&res->blocked);
580 INIT_LIST_HEAD(&res->dirty);
581 INIT_LIST_HEAD(&res->recovering);
582 INIT_LIST_HEAD(&res->purge);
583 INIT_LIST_HEAD(&res->tracking);
584 atomic_set(&res->asts_reserved, 0);
585 res->migration_pending = 0;
586 res->inflight_locks = 0;
588 /* put in dlm_lockres_release */
592 kref_init(&res->refs);
594 atomic_inc(&dlm->res_tot_count);
595 atomic_inc(&dlm->res_cur_count);
597 /* just for consistency */
598 spin_lock(&res->spinlock);
599 dlm_set_lockres_owner(dlm, res, DLM_LOCK_RES_OWNER_UNKNOWN);
600 spin_unlock(&res->spinlock);
602 res->state = DLM_LOCK_RES_IN_PROGRESS;
606 spin_lock(&dlm->spinlock);
607 list_add_tail(&res->tracking, &dlm->tracking_list);
608 spin_unlock(&dlm->spinlock);
610 memset(res->lvb, 0, DLM_LVB_LEN);
611 memset(res->refmap, 0, sizeof(res->refmap));
614 struct dlm_lock_resource *dlm_new_lockres(struct dlm_ctxt *dlm,
616 unsigned int namelen)
618 struct dlm_lock_resource *res = NULL;
620 res = kmem_cache_zalloc(dlm_lockres_cache, GFP_NOFS);
624 res->lockname.name = kmem_cache_zalloc(dlm_lockname_cache, GFP_NOFS);
625 if (!res->lockname.name)
628 dlm_init_lockres(dlm, res, name, namelen);
632 if (res && res->lockname.name)
633 kmem_cache_free(dlm_lockname_cache, (void *)res->lockname.name);
636 kmem_cache_free(dlm_lockres_cache, res);
640 void __dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm,
641 struct dlm_lock_resource *res,
647 assert_spin_locked(&res->spinlock);
649 if (!test_bit(dlm->node_num, res->refmap)) {
650 BUG_ON(res->inflight_locks != 0);
651 dlm_lockres_set_refmap_bit(dlm->node_num, res);
653 res->inflight_locks++;
654 mlog(0, "%s:%.*s: inflight++: now %u\n",
655 dlm->name, res->lockname.len, res->lockname.name,
656 res->inflight_locks);
659 void __dlm_lockres_drop_inflight_ref(struct dlm_ctxt *dlm,
660 struct dlm_lock_resource *res,
664 assert_spin_locked(&res->spinlock);
666 BUG_ON(res->inflight_locks == 0);
667 res->inflight_locks--;
668 mlog(0, "%s:%.*s: inflight--: now %u\n",
669 dlm->name, res->lockname.len, res->lockname.name,
670 res->inflight_locks);
671 if (res->inflight_locks == 0)
672 dlm_lockres_clear_refmap_bit(dlm->node_num, res);
677 * lookup a lock resource by name.
678 * may already exist in the hashtable.
679 * lockid is null terminated
681 * if not, allocate enough for the lockres and for
682 * the temporary structure used in doing the mastering.
684 * also, do a lookup in the dlm->master_list to see
685 * if another node has begun mastering the same lock.
686 * if so, there should be a block entry in there
687 * for this name, and we should *not* attempt to master
688 * the lock here. need to wait around for that node
689 * to assert_master (or die).
692 struct dlm_lock_resource * dlm_get_lock_resource(struct dlm_ctxt *dlm,
697 struct dlm_lock_resource *tmpres=NULL, *res=NULL;
698 struct dlm_master_list_entry *mle = NULL;
699 struct dlm_master_list_entry *alloc_mle = NULL;
702 struct dlm_node_iter iter;
705 int bit, wait_on_recovery = 0;
706 int drop_inflight_if_nonlocal = 0;
710 hash = dlm_lockid_hash(lockid, namelen);
712 mlog(0, "get lockres %s (len %d)\n", lockid, namelen);
715 spin_lock(&dlm->spinlock);
716 tmpres = __dlm_lookup_lockres_full(dlm, lockid, namelen, hash);
718 int dropping_ref = 0;
720 spin_unlock(&dlm->spinlock);
722 spin_lock(&tmpres->spinlock);
723 /* We wait for the other thread that is mastering the resource */
724 if (tmpres->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
725 __dlm_wait_on_lockres(tmpres);
726 BUG_ON(tmpres->owner == DLM_LOCK_RES_OWNER_UNKNOWN);
729 if (tmpres->owner == dlm->node_num) {
730 BUG_ON(tmpres->state & DLM_LOCK_RES_DROPPING_REF);
731 dlm_lockres_grab_inflight_ref(dlm, tmpres);
732 } else if (tmpres->state & DLM_LOCK_RES_DROPPING_REF)
734 spin_unlock(&tmpres->spinlock);
736 /* wait until done messaging the master, drop our ref to allow
737 * the lockres to be purged, start over. */
739 spin_lock(&tmpres->spinlock);
740 __dlm_wait_on_lockres_flags(tmpres, DLM_LOCK_RES_DROPPING_REF);
741 spin_unlock(&tmpres->spinlock);
742 dlm_lockres_put(tmpres);
747 mlog(0, "found in hash!\n");
749 dlm_lockres_put(res);
755 spin_unlock(&dlm->spinlock);
756 mlog(0, "allocating a new resource\n");
757 /* nothing found and we need to allocate one. */
758 alloc_mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
761 res = dlm_new_lockres(dlm, lockid, namelen);
767 mlog(0, "no lockres found, allocated our own: %p\n", res);
769 if (flags & LKM_LOCAL) {
770 /* caller knows it's safe to assume it's not mastered elsewhere
771 * DONE! return right away */
772 spin_lock(&res->spinlock);
773 dlm_change_lockres_owner(dlm, res, dlm->node_num);
774 __dlm_insert_lockres(dlm, res);
775 dlm_lockres_grab_inflight_ref(dlm, res);
776 spin_unlock(&res->spinlock);
777 spin_unlock(&dlm->spinlock);
778 /* lockres still marked IN_PROGRESS */
782 /* check master list to see if another node has started mastering it */
783 spin_lock(&dlm->master_lock);
785 /* if we found a block, wait for lock to be mastered by another node */
786 blocked = dlm_find_mle(dlm, &mle, (char *)lockid, namelen);
789 if (mle->type == DLM_MLE_MASTER) {
790 mlog(ML_ERROR, "master entry for nonexistent lock!\n");
793 mig = (mle->type == DLM_MLE_MIGRATION);
794 /* if there is a migration in progress, let the migration
795 * finish before continuing. we can wait for the absence
796 * of the MIGRATION mle: either the migrate finished or
797 * one of the nodes died and the mle was cleaned up.
798 * if there is a BLOCK here, but it already has a master
799 * set, we are too late. the master does not have a ref
800 * for us in the refmap. detach the mle and drop it.
801 * either way, go back to the top and start over. */
802 if (mig || mle->master != O2NM_MAX_NODES) {
803 BUG_ON(mig && mle->master == dlm->node_num);
804 /* we arrived too late. the master does not
805 * have a ref for us. retry. */
806 mlog(0, "%s:%.*s: late on %s\n",
807 dlm->name, namelen, lockid,
808 mig ? "MIGRATION" : "BLOCK");
809 spin_unlock(&dlm->master_lock);
810 spin_unlock(&dlm->spinlock);
812 /* master is known, detach */
814 dlm_mle_detach_hb_events(dlm, mle);
817 /* this is lame, but we cant wait on either
818 * the mle or lockres waitqueue here */
824 /* go ahead and try to master lock on this node */
826 /* make sure this does not get freed below */
828 dlm_init_mle(mle, DLM_MLE_MASTER, dlm, res, NULL, 0);
829 set_bit(dlm->node_num, mle->maybe_map);
830 __dlm_insert_mle(dlm, mle);
832 /* still holding the dlm spinlock, check the recovery map
833 * to see if there are any nodes that still need to be
834 * considered. these will not appear in the mle nodemap
835 * but they might own this lockres. wait on them. */
836 bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0);
837 if (bit < O2NM_MAX_NODES) {
838 mlog(ML_NOTICE, "%s:%.*s: at least one node (%d) to "
839 "recover before lock mastery can begin\n",
840 dlm->name, namelen, (char *)lockid, bit);
841 wait_on_recovery = 1;
845 /* at this point there is either a DLM_MLE_BLOCK or a
846 * DLM_MLE_MASTER on the master list, so it's safe to add the
847 * lockres to the hashtable. anyone who finds the lock will
848 * still have to wait on the IN_PROGRESS. */
850 /* finally add the lockres to its hash bucket */
851 __dlm_insert_lockres(dlm, res);
852 /* since this lockres is new it doesnt not require the spinlock */
853 dlm_lockres_grab_inflight_ref_new(dlm, res);
855 /* if this node does not become the master make sure to drop
856 * this inflight reference below */
857 drop_inflight_if_nonlocal = 1;
859 /* get an extra ref on the mle in case this is a BLOCK
860 * if so, the creator of the BLOCK may try to put the last
861 * ref at this time in the assert master handler, so we
862 * need an extra one to keep from a bad ptr deref. */
863 dlm_get_mle_inuse(mle);
864 spin_unlock(&dlm->master_lock);
865 spin_unlock(&dlm->spinlock);
868 while (wait_on_recovery) {
869 /* any cluster changes that occurred after dropping the
870 * dlm spinlock would be detectable be a change on the mle,
871 * so we only need to clear out the recovery map once. */
872 if (dlm_is_recovery_lock(lockid, namelen)) {
873 mlog(ML_NOTICE, "%s: recovery map is not empty, but "
874 "must master $RECOVERY lock now\n", dlm->name);
875 if (!dlm_pre_master_reco_lockres(dlm, res))
876 wait_on_recovery = 0;
878 mlog(0, "%s: waiting 500ms for heartbeat state "
879 "change\n", dlm->name);
885 dlm_kick_recovery_thread(dlm);
887 dlm_wait_for_recovery(dlm);
889 spin_lock(&dlm->spinlock);
890 bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0);
891 if (bit < O2NM_MAX_NODES) {
892 mlog(ML_NOTICE, "%s:%.*s: at least one node (%d) to "
893 "recover before lock mastery can begin\n",
894 dlm->name, namelen, (char *)lockid, bit);
895 wait_on_recovery = 1;
897 wait_on_recovery = 0;
898 spin_unlock(&dlm->spinlock);
900 if (wait_on_recovery)
901 dlm_wait_for_node_recovery(dlm, bit, 10000);
904 /* must wait for lock to be mastered elsewhere */
909 dlm_node_iter_init(mle->vote_map, &iter);
910 while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
911 ret = dlm_do_master_request(res, mle, nodenum);
914 if (mle->master != O2NM_MAX_NODES) {
915 /* found a master ! */
916 if (mle->master <= nodenum)
918 /* if our master request has not reached the master
919 * yet, keep going until it does. this is how the
920 * master will know that asserts are needed back to
921 * the lower nodes. */
922 mlog(0, "%s:%.*s: requests only up to %u but master "
923 "is %u, keep going\n", dlm->name, namelen,
924 lockid, nodenum, mle->master);
929 /* keep going until the response map includes all nodes */
930 ret = dlm_wait_for_lock_mastery(dlm, res, mle, &blocked);
932 wait_on_recovery = 1;
933 mlog(0, "%s:%.*s: node map changed, redo the "
934 "master request now, blocked=%d\n",
935 dlm->name, res->lockname.len,
936 res->lockname.name, blocked);
938 mlog(ML_ERROR, "%s:%.*s: spinning on "
939 "dlm_wait_for_lock_mastery, blocked=%d\n",
940 dlm->name, res->lockname.len,
941 res->lockname.name, blocked);
942 dlm_print_one_lock_resource(res);
943 dlm_print_one_mle(mle);
949 mlog(0, "lockres mastered by %u\n", res->owner);
950 /* make sure we never continue without this */
951 BUG_ON(res->owner == O2NM_MAX_NODES);
953 /* master is known, detach if not already detached */
954 dlm_mle_detach_hb_events(dlm, mle);
956 /* put the extra ref */
957 dlm_put_mle_inuse(mle);
960 spin_lock(&res->spinlock);
961 if (res->owner != dlm->node_num && drop_inflight_if_nonlocal)
962 dlm_lockres_drop_inflight_ref(dlm, res);
963 res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
964 spin_unlock(&res->spinlock);
968 /* need to free the unused mle */
970 kmem_cache_free(dlm_mle_cache, alloc_mle);
976 #define DLM_MASTERY_TIMEOUT_MS 5000
978 static int dlm_wait_for_lock_mastery(struct dlm_ctxt *dlm,
979 struct dlm_lock_resource *res,
980 struct dlm_master_list_entry *mle,
985 int map_changed, voting_done;
992 /* check if another node has already become the owner */
993 spin_lock(&res->spinlock);
994 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
995 mlog(0, "%s:%.*s: owner is suddenly %u\n", dlm->name,
996 res->lockname.len, res->lockname.name, res->owner);
997 spin_unlock(&res->spinlock);
998 /* this will cause the master to re-assert across
999 * the whole cluster, freeing up mles */
1000 if (res->owner != dlm->node_num) {
1001 ret = dlm_do_master_request(res, mle, res->owner);
1003 /* give recovery a chance to run */
1004 mlog(ML_ERROR, "link to %u went down?: %d\n", res->owner, ret);
1012 spin_unlock(&res->spinlock);
1014 spin_lock(&mle->spinlock);
1016 map_changed = (memcmp(mle->vote_map, mle->node_map,
1017 sizeof(mle->vote_map)) != 0);
1018 voting_done = (memcmp(mle->vote_map, mle->response_map,
1019 sizeof(mle->vote_map)) == 0);
1021 /* restart if we hit any errors */
1024 mlog(0, "%s: %.*s: node map changed, restarting\n",
1025 dlm->name, res->lockname.len, res->lockname.name);
1026 ret = dlm_restart_lock_mastery(dlm, res, mle, *blocked);
1027 b = (mle->type == DLM_MLE_BLOCK);
1028 if ((*blocked && !b) || (!*blocked && b)) {
1029 mlog(0, "%s:%.*s: status change: old=%d new=%d\n",
1030 dlm->name, res->lockname.len, res->lockname.name,
1034 spin_unlock(&mle->spinlock);
1039 mlog(0, "%s:%.*s: restart lock mastery succeeded, "
1040 "rechecking now\n", dlm->name, res->lockname.len,
1041 res->lockname.name);
1045 mlog(0, "map not changed and voting not done "
1046 "for %s:%.*s\n", dlm->name, res->lockname.len,
1047 res->lockname.name);
1051 if (m != O2NM_MAX_NODES) {
1052 /* another node has done an assert!
1057 /* have all nodes responded? */
1058 if (voting_done && !*blocked) {
1059 bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0);
1060 if (dlm->node_num <= bit) {
1061 /* my node number is lowest.
1062 * now tell other nodes that I am
1063 * mastering this. */
1064 mle->master = dlm->node_num;
1065 /* ref was grabbed in get_lock_resource
1066 * will be dropped in dlmlock_master */
1070 /* if voting is done, but we have not received
1071 * an assert master yet, we must sleep */
1075 spin_unlock(&mle->spinlock);
1077 /* sleep if we haven't finished voting yet */
1079 unsigned long timeo = msecs_to_jiffies(DLM_MASTERY_TIMEOUT_MS);
1082 if (atomic_read(&mle->mle_refs.refcount) < 2)
1083 mlog(ML_ERROR, "mle (%p) refs=%d, name=%.*s\n", mle,
1084 atomic_read(&mle->mle_refs.refcount),
1085 res->lockname.len, res->lockname.name);
1087 atomic_set(&mle->woken, 0);
1088 (void)wait_event_timeout(mle->wq,
1089 (atomic_read(&mle->woken) == 1),
1091 if (res->owner == O2NM_MAX_NODES) {
1092 mlog(0, "%s:%.*s: waiting again\n", dlm->name,
1093 res->lockname.len, res->lockname.name);
1096 mlog(0, "done waiting, master is %u\n", res->owner);
1104 mlog(0, "about to master %.*s here, this=%u\n",
1105 res->lockname.len, res->lockname.name, m);
1106 ret = dlm_do_assert_master(dlm, res, mle->vote_map, 0);
1108 /* This is a failure in the network path,
1109 * not in the response to the assert_master
1110 * (any nonzero response is a BUG on this node).
1111 * Most likely a socket just got disconnected
1112 * due to node death. */
1115 /* no longer need to restart lock mastery.
1116 * all living nodes have been contacted. */
1120 /* set the lockres owner */
1121 spin_lock(&res->spinlock);
1122 /* mastery reference obtained either during
1123 * assert_master_handler or in get_lock_resource */
1124 dlm_change_lockres_owner(dlm, res, m);
1125 spin_unlock(&res->spinlock);
1131 struct dlm_bitmap_diff_iter
1134 unsigned long *orig_bm;
1135 unsigned long *cur_bm;
1136 unsigned long diff_bm[BITS_TO_LONGS(O2NM_MAX_NODES)];
1139 enum dlm_node_state_change
1146 static void dlm_bitmap_diff_iter_init(struct dlm_bitmap_diff_iter *iter,
1147 unsigned long *orig_bm,
1148 unsigned long *cur_bm)
1150 unsigned long p1, p2;
1154 iter->orig_bm = orig_bm;
1155 iter->cur_bm = cur_bm;
1157 for (i = 0; i < BITS_TO_LONGS(O2NM_MAX_NODES); i++) {
1158 p1 = *(iter->orig_bm + i);
1159 p2 = *(iter->cur_bm + i);
1160 iter->diff_bm[i] = (p1 & ~p2) | (p2 & ~p1);
1164 static int dlm_bitmap_diff_iter_next(struct dlm_bitmap_diff_iter *iter,
1165 enum dlm_node_state_change *state)
1169 if (iter->curnode >= O2NM_MAX_NODES)
1172 bit = find_next_bit(iter->diff_bm, O2NM_MAX_NODES,
1174 if (bit >= O2NM_MAX_NODES) {
1175 iter->curnode = O2NM_MAX_NODES;
1179 /* if it was there in the original then this node died */
1180 if (test_bit(bit, iter->orig_bm))
1185 iter->curnode = bit;
1190 static int dlm_restart_lock_mastery(struct dlm_ctxt *dlm,
1191 struct dlm_lock_resource *res,
1192 struct dlm_master_list_entry *mle,
1195 struct dlm_bitmap_diff_iter bdi;
1196 enum dlm_node_state_change sc;
1200 mlog(0, "something happened such that the "
1201 "master process may need to be restarted!\n");
1203 assert_spin_locked(&mle->spinlock);
1205 dlm_bitmap_diff_iter_init(&bdi, mle->vote_map, mle->node_map);
1206 node = dlm_bitmap_diff_iter_next(&bdi, &sc);
1208 if (sc == NODE_UP) {
1209 /* a node came up. clear any old vote from
1210 * the response map and set it in the vote map
1211 * then restart the mastery. */
1212 mlog(ML_NOTICE, "node %d up while restarting\n", node);
1214 /* redo the master request, but only for the new node */
1215 mlog(0, "sending request to new node\n");
1216 clear_bit(node, mle->response_map);
1217 set_bit(node, mle->vote_map);
1219 mlog(ML_ERROR, "node down! %d\n", node);
1221 int lowest = find_next_bit(mle->maybe_map,
1224 /* act like it was never there */
1225 clear_bit(node, mle->maybe_map);
1227 if (node == lowest) {
1228 mlog(0, "expected master %u died"
1229 " while this node was blocked "
1230 "waiting on it!\n", node);
1231 lowest = find_next_bit(mle->maybe_map,
1234 if (lowest < O2NM_MAX_NODES) {
1235 mlog(0, "%s:%.*s:still "
1236 "blocked. waiting on %u "
1242 /* mle is an MLE_BLOCK, but
1243 * there is now nothing left to
1244 * block on. we need to return
1245 * all the way back out and try
1246 * again with an MLE_MASTER.
1247 * dlm_do_local_recovery_cleanup
1248 * has already run, so the mle
1250 mlog(0, "%s:%.*s: no "
1251 "longer blocking. try to "
1252 "master this here\n",
1255 res->lockname.name);
1256 mle->type = DLM_MLE_MASTER;
1262 /* now blank out everything, as if we had never
1263 * contacted anyone */
1264 memset(mle->maybe_map, 0, sizeof(mle->maybe_map));
1265 memset(mle->response_map, 0, sizeof(mle->response_map));
1266 /* reset the vote_map to the current node_map */
1267 memcpy(mle->vote_map, mle->node_map,
1268 sizeof(mle->node_map));
1269 /* put myself into the maybe map */
1270 if (mle->type != DLM_MLE_BLOCK)
1271 set_bit(dlm->node_num, mle->maybe_map);
1274 node = dlm_bitmap_diff_iter_next(&bdi, &sc);
1281 * DLM_MASTER_REQUEST_MSG
1283 * returns: 0 on success,
1284 * -errno on a network error
1286 * on error, the caller should assume the target node is "dead"
1290 static int dlm_do_master_request(struct dlm_lock_resource *res,
1291 struct dlm_master_list_entry *mle, int to)
1293 struct dlm_ctxt *dlm = mle->dlm;
1294 struct dlm_master_request request;
1295 int ret, response=0, resend;
1297 memset(&request, 0, sizeof(request));
1298 request.node_idx = dlm->node_num;
1300 BUG_ON(mle->type == DLM_MLE_MIGRATION);
1302 request.namelen = (u8)mle->mnamelen;
1303 memcpy(request.name, mle->mname, request.namelen);
1306 ret = o2net_send_message(DLM_MASTER_REQUEST_MSG, dlm->key, &request,
1307 sizeof(request), to, &response);
1309 if (ret == -ESRCH) {
1310 /* should never happen */
1311 mlog(ML_ERROR, "TCP stack not ready!\n");
1313 } else if (ret == -EINVAL) {
1314 mlog(ML_ERROR, "bad args passed to o2net!\n");
1316 } else if (ret == -ENOMEM) {
1317 mlog(ML_ERROR, "out of memory while trying to send "
1318 "network message! retrying\n");
1319 /* this is totally crude */
1322 } else if (!dlm_is_host_down(ret)) {
1323 /* not a network error. bad. */
1325 mlog(ML_ERROR, "unhandled error!");
1328 /* all other errors should be network errors,
1329 * and likely indicate node death */
1330 mlog(ML_ERROR, "link to %d went down!\n", to);
1336 spin_lock(&mle->spinlock);
1338 case DLM_MASTER_RESP_YES:
1339 set_bit(to, mle->response_map);
1340 mlog(0, "node %u is the master, response=YES\n", to);
1341 mlog(0, "%s:%.*s: master node %u now knows I have a "
1342 "reference\n", dlm->name, res->lockname.len,
1343 res->lockname.name, to);
1346 case DLM_MASTER_RESP_NO:
1347 mlog(0, "node %u not master, response=NO\n", to);
1348 set_bit(to, mle->response_map);
1350 case DLM_MASTER_RESP_MAYBE:
1351 mlog(0, "node %u not master, response=MAYBE\n", to);
1352 set_bit(to, mle->response_map);
1353 set_bit(to, mle->maybe_map);
1355 case DLM_MASTER_RESP_ERROR:
1356 mlog(0, "node %u hit an error, resending\n", to);
1361 mlog(ML_ERROR, "bad response! %u\n", response);
1364 spin_unlock(&mle->spinlock);
1366 /* this is also totally crude */
1376 * locks that can be taken here:
1382 * if possible, TRIM THIS DOWN!!!
1384 int dlm_master_request_handler(struct o2net_msg *msg, u32 len, void *data,
1387 u8 response = DLM_MASTER_RESP_MAYBE;
1388 struct dlm_ctxt *dlm = data;
1389 struct dlm_lock_resource *res = NULL;
1390 struct dlm_master_request *request = (struct dlm_master_request *) msg->buf;
1391 struct dlm_master_list_entry *mle = NULL, *tmpmle = NULL;
1393 unsigned int namelen, hash;
1396 int dispatch_assert = 0;
1399 return DLM_MASTER_RESP_NO;
1401 if (!dlm_domain_fully_joined(dlm)) {
1402 response = DLM_MASTER_RESP_NO;
1406 name = request->name;
1407 namelen = request->namelen;
1408 hash = dlm_lockid_hash(name, namelen);
1410 if (namelen > DLM_LOCKID_NAME_MAX) {
1411 response = DLM_IVBUFLEN;
1416 spin_lock(&dlm->spinlock);
1417 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
1419 spin_unlock(&dlm->spinlock);
1421 /* take care of the easy cases up front */
1422 spin_lock(&res->spinlock);
1423 if (res->state & (DLM_LOCK_RES_RECOVERING|
1424 DLM_LOCK_RES_MIGRATING)) {
1425 spin_unlock(&res->spinlock);
1426 mlog(0, "returning DLM_MASTER_RESP_ERROR since res is "
1427 "being recovered/migrated\n");
1428 response = DLM_MASTER_RESP_ERROR;
1430 kmem_cache_free(dlm_mle_cache, mle);
1434 if (res->owner == dlm->node_num) {
1435 mlog(0, "%s:%.*s: setting bit %u in refmap\n",
1436 dlm->name, namelen, name, request->node_idx);
1437 dlm_lockres_set_refmap_bit(request->node_idx, res);
1438 spin_unlock(&res->spinlock);
1439 response = DLM_MASTER_RESP_YES;
1441 kmem_cache_free(dlm_mle_cache, mle);
1443 /* this node is the owner.
1444 * there is some extra work that needs to
1445 * happen now. the requesting node has
1446 * caused all nodes up to this one to
1447 * create mles. this node now needs to
1448 * go back and clean those up. */
1449 dispatch_assert = 1;
1451 } else if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
1452 spin_unlock(&res->spinlock);
1453 // mlog(0, "node %u is the master\n", res->owner);
1454 response = DLM_MASTER_RESP_NO;
1456 kmem_cache_free(dlm_mle_cache, mle);
1460 /* ok, there is no owner. either this node is
1461 * being blocked, or it is actively trying to
1462 * master this lock. */
1463 if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) {
1464 mlog(ML_ERROR, "lock with no owner should be "
1469 // mlog(0, "lockres is in progress...\n");
1470 spin_lock(&dlm->master_lock);
1471 found = dlm_find_mle(dlm, &tmpmle, name, namelen);
1473 mlog(ML_ERROR, "no mle found for this lock!\n");
1477 spin_lock(&tmpmle->spinlock);
1478 if (tmpmle->type == DLM_MLE_BLOCK) {
1479 // mlog(0, "this node is waiting for "
1480 // "lockres to be mastered\n");
1481 response = DLM_MASTER_RESP_NO;
1482 } else if (tmpmle->type == DLM_MLE_MIGRATION) {
1483 mlog(0, "node %u is master, but trying to migrate to "
1484 "node %u.\n", tmpmle->master, tmpmle->new_master);
1485 if (tmpmle->master == dlm->node_num) {
1486 mlog(ML_ERROR, "no owner on lockres, but this "
1487 "node is trying to migrate it to %u?!\n",
1488 tmpmle->new_master);
1491 /* the real master can respond on its own */
1492 response = DLM_MASTER_RESP_NO;
1494 } else if (tmpmle->master != DLM_LOCK_RES_OWNER_UNKNOWN) {
1496 if (tmpmle->master == dlm->node_num) {
1497 response = DLM_MASTER_RESP_YES;
1498 /* this node will be the owner.
1499 * go back and clean the mles on any
1501 dispatch_assert = 1;
1502 dlm_lockres_set_refmap_bit(request->node_idx, res);
1503 mlog(0, "%s:%.*s: setting bit %u in refmap\n",
1504 dlm->name, namelen, name,
1507 response = DLM_MASTER_RESP_NO;
1509 // mlog(0, "this node is attempting to "
1510 // "master lockres\n");
1511 response = DLM_MASTER_RESP_MAYBE;
1514 set_bit(request->node_idx, tmpmle->maybe_map);
1515 spin_unlock(&tmpmle->spinlock);
1517 spin_unlock(&dlm->master_lock);
1518 spin_unlock(&res->spinlock);
1520 /* keep the mle attached to heartbeat events */
1521 dlm_put_mle(tmpmle);
1523 kmem_cache_free(dlm_mle_cache, mle);
1528 * lockres doesn't exist on this node
1529 * if there is an MLE_BLOCK, return NO
1530 * if there is an MLE_MASTER, return MAYBE
1531 * otherwise, add an MLE_BLOCK, return NO
1533 spin_lock(&dlm->master_lock);
1534 found = dlm_find_mle(dlm, &tmpmle, name, namelen);
1536 /* this lockid has never been seen on this node yet */
1537 // mlog(0, "no mle found\n");
1539 spin_unlock(&dlm->master_lock);
1540 spin_unlock(&dlm->spinlock);
1542 mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
1544 response = DLM_MASTER_RESP_ERROR;
1545 mlog_errno(-ENOMEM);
1551 // mlog(0, "this is second time thru, already allocated, "
1552 // "add the block.\n");
1553 dlm_init_mle(mle, DLM_MLE_BLOCK, dlm, NULL, name, namelen);
1554 set_bit(request->node_idx, mle->maybe_map);
1555 __dlm_insert_mle(dlm, mle);
1556 response = DLM_MASTER_RESP_NO;
1558 // mlog(0, "mle was found\n");
1560 spin_lock(&tmpmle->spinlock);
1561 if (tmpmle->master == dlm->node_num) {
1562 mlog(ML_ERROR, "no lockres, but an mle with this node as master!\n");
1565 if (tmpmle->type == DLM_MLE_BLOCK)
1566 response = DLM_MASTER_RESP_NO;
1567 else if (tmpmle->type == DLM_MLE_MIGRATION) {
1568 mlog(0, "migration mle was found (%u->%u)\n",
1569 tmpmle->master, tmpmle->new_master);
1570 /* real master can respond on its own */
1571 response = DLM_MASTER_RESP_NO;
1573 response = DLM_MASTER_RESP_MAYBE;
1575 set_bit(request->node_idx, tmpmle->maybe_map);
1576 spin_unlock(&tmpmle->spinlock);
1578 spin_unlock(&dlm->master_lock);
1579 spin_unlock(&dlm->spinlock);
1582 /* keep the mle attached to heartbeat events */
1583 dlm_put_mle(tmpmle);
1587 * __dlm_lookup_lockres() grabbed a reference to this lockres.
1588 * The reference is released by dlm_assert_master_worker() under
1589 * the call to dlm_dispatch_assert_master(). If
1590 * dlm_assert_master_worker() isn't called, we drop it here.
1592 if (dispatch_assert) {
1593 if (response != DLM_MASTER_RESP_YES)
1594 mlog(ML_ERROR, "invalid response %d\n", response);
1596 mlog(ML_ERROR, "bad lockres while trying to assert!\n");
1599 mlog(0, "%u is the owner of %.*s, cleaning everyone else\n",
1600 dlm->node_num, res->lockname.len, res->lockname.name);
1601 ret = dlm_dispatch_assert_master(dlm, res, 0, request->node_idx,
1602 DLM_ASSERT_MASTER_MLE_CLEANUP);
1604 mlog(ML_ERROR, "failed to dispatch assert master work\n");
1605 response = DLM_MASTER_RESP_ERROR;
1606 dlm_lockres_put(res);
1610 dlm_lockres_put(res);
1618 * DLM_ASSERT_MASTER_MSG
1623 * NOTE: this can be used for debugging
1624 * can periodically run all locks owned by this node
1625 * and re-assert across the cluster...
1627 static int dlm_do_assert_master(struct dlm_ctxt *dlm,
1628 struct dlm_lock_resource *res,
1629 void *nodemap, u32 flags)
1631 struct dlm_assert_master assert;
1633 struct dlm_node_iter iter;
1636 const char *lockname = res->lockname.name;
1637 unsigned int namelen = res->lockname.len;
1639 BUG_ON(namelen > O2NM_MAX_NAME_LEN);
1641 spin_lock(&res->spinlock);
1642 res->state |= DLM_LOCK_RES_SETREF_INPROG;
1643 spin_unlock(&res->spinlock);
1648 /* note that if this nodemap is empty, it returns 0 */
1649 dlm_node_iter_init(nodemap, &iter);
1650 while ((to = dlm_node_iter_next(&iter)) >= 0) {
1652 struct dlm_master_list_entry *mle = NULL;
1654 mlog(0, "sending assert master to %d (%.*s)\n", to,
1656 memset(&assert, 0, sizeof(assert));
1657 assert.node_idx = dlm->node_num;
1658 assert.namelen = namelen;
1659 memcpy(assert.name, lockname, namelen);
1660 assert.flags = cpu_to_be32(flags);
1662 tmpret = o2net_send_message(DLM_ASSERT_MASTER_MSG, dlm->key,
1663 &assert, sizeof(assert), to, &r);
1665 mlog(ML_ERROR, "Error %d when sending message %u (key "
1666 "0x%x) to node %u\n", tmpret,
1667 DLM_ASSERT_MASTER_MSG, dlm->key, to);
1668 if (!dlm_is_host_down(tmpret)) {
1669 mlog(ML_ERROR, "unhandled error=%d!\n", tmpret);
1672 /* a node died. finish out the rest of the nodes. */
1673 mlog(0, "link to %d went down!\n", to);
1674 /* any nonzero status return will do */
1678 /* ok, something horribly messed. kill thyself. */
1679 mlog(ML_ERROR,"during assert master of %.*s to %u, "
1680 "got %d.\n", namelen, lockname, to, r);
1681 spin_lock(&dlm->spinlock);
1682 spin_lock(&dlm->master_lock);
1683 if (dlm_find_mle(dlm, &mle, (char *)lockname,
1685 dlm_print_one_mle(mle);
1688 spin_unlock(&dlm->master_lock);
1689 spin_unlock(&dlm->spinlock);
1693 if (r & DLM_ASSERT_RESPONSE_REASSERT &&
1694 !(r & DLM_ASSERT_RESPONSE_MASTERY_REF)) {
1695 mlog(ML_ERROR, "%.*s: very strange, "
1696 "master MLE but no lockres on %u\n",
1697 namelen, lockname, to);
1700 if (r & DLM_ASSERT_RESPONSE_REASSERT) {
1701 mlog(0, "%.*s: node %u create mles on other "
1702 "nodes and requests a re-assert\n",
1703 namelen, lockname, to);
1706 if (r & DLM_ASSERT_RESPONSE_MASTERY_REF) {
1707 mlog(0, "%.*s: node %u has a reference to this "
1708 "lockres, set the bit in the refmap\n",
1709 namelen, lockname, to);
1710 spin_lock(&res->spinlock);
1711 dlm_lockres_set_refmap_bit(to, res);
1712 spin_unlock(&res->spinlock);
1719 spin_lock(&res->spinlock);
1720 res->state &= ~DLM_LOCK_RES_SETREF_INPROG;
1721 spin_unlock(&res->spinlock);
1728 * locks that can be taken here:
1734 * if possible, TRIM THIS DOWN!!!
1736 int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data,
1739 struct dlm_ctxt *dlm = data;
1740 struct dlm_master_list_entry *mle = NULL;
1741 struct dlm_assert_master *assert = (struct dlm_assert_master *)msg->buf;
1742 struct dlm_lock_resource *res = NULL;
1744 unsigned int namelen, hash;
1746 int master_request = 0, have_lockres_ref = 0;
1752 name = assert->name;
1753 namelen = assert->namelen;
1754 hash = dlm_lockid_hash(name, namelen);
1755 flags = be32_to_cpu(assert->flags);
1757 if (namelen > DLM_LOCKID_NAME_MAX) {
1758 mlog(ML_ERROR, "Invalid name length!");
1762 spin_lock(&dlm->spinlock);
1765 mlog(0, "assert_master with flags: %u\n", flags);
1768 spin_lock(&dlm->master_lock);
1769 if (!dlm_find_mle(dlm, &mle, name, namelen)) {
1770 /* not an error, could be master just re-asserting */
1771 mlog(0, "just got an assert_master from %u, but no "
1772 "MLE for it! (%.*s)\n", assert->node_idx,
1775 int bit = find_next_bit (mle->maybe_map, O2NM_MAX_NODES, 0);
1776 if (bit >= O2NM_MAX_NODES) {
1777 /* not necessarily an error, though less likely.
1778 * could be master just re-asserting. */
1779 mlog(0, "no bits set in the maybe_map, but %u "
1780 "is asserting! (%.*s)\n", assert->node_idx,
1782 } else if (bit != assert->node_idx) {
1783 if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) {
1784 mlog(0, "master %u was found, %u should "
1785 "back off\n", assert->node_idx, bit);
1787 /* with the fix for bug 569, a higher node
1788 * number winning the mastery will respond
1789 * YES to mastery requests, but this node
1790 * had no way of knowing. let it pass. */
1791 mlog(0, "%u is the lowest node, "
1792 "%u is asserting. (%.*s) %u must "
1793 "have begun after %u won.\n", bit,
1794 assert->node_idx, namelen, name, bit,
1798 if (mle->type == DLM_MLE_MIGRATION) {
1799 if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) {
1800 mlog(0, "%s:%.*s: got cleanup assert"
1801 " from %u for migration\n",
1802 dlm->name, namelen, name,
1804 } else if (!(flags & DLM_ASSERT_MASTER_FINISH_MIGRATION)) {
1805 mlog(0, "%s:%.*s: got unrelated assert"
1806 " from %u for migration, ignoring\n",
1807 dlm->name, namelen, name,
1810 spin_unlock(&dlm->master_lock);
1811 spin_unlock(&dlm->spinlock);
1816 spin_unlock(&dlm->master_lock);
1818 /* ok everything checks out with the MLE
1819 * now check to see if there is a lockres */
1820 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
1822 spin_lock(&res->spinlock);
1823 if (res->state & DLM_LOCK_RES_RECOVERING) {
1824 mlog(ML_ERROR, "%u asserting but %.*s is "
1825 "RECOVERING!\n", assert->node_idx, namelen, name);
1829 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN &&
1830 res->owner != assert->node_idx) {
1831 mlog(ML_ERROR, "DIE! Mastery assert from %u, "
1832 "but current owner is %u! (%.*s)\n",
1833 assert->node_idx, res->owner, namelen,
1835 __dlm_print_one_lock_resource(res);
1838 } else if (mle->type != DLM_MLE_MIGRATION) {
1839 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
1840 /* owner is just re-asserting */
1841 if (res->owner == assert->node_idx) {
1842 mlog(0, "owner %u re-asserting on "
1843 "lock %.*s\n", assert->node_idx,
1847 mlog(ML_ERROR, "got assert_master from "
1848 "node %u, but %u is the owner! "
1849 "(%.*s)\n", assert->node_idx,
1850 res->owner, namelen, name);
1853 if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) {
1854 mlog(ML_ERROR, "got assert from %u, but lock "
1855 "with no owner should be "
1856 "in-progress! (%.*s)\n",
1861 } else /* mle->type == DLM_MLE_MIGRATION */ {
1862 /* should only be getting an assert from new master */
1863 if (assert->node_idx != mle->new_master) {
1864 mlog(ML_ERROR, "got assert from %u, but "
1865 "new master is %u, and old master "
1867 assert->node_idx, mle->new_master,
1868 mle->master, namelen, name);
1874 spin_unlock(&res->spinlock);
1877 // mlog(0, "woo! got an assert_master from node %u!\n",
1878 // assert->node_idx);
1884 spin_lock(&mle->spinlock);
1885 if (mle->type == DLM_MLE_BLOCK || mle->type == DLM_MLE_MIGRATION)
1888 /* MASTER mle: if any bits set in the response map
1889 * then the calling node needs to re-assert to clear
1890 * up nodes that this node contacted */
1891 while ((nn = find_next_bit (mle->response_map, O2NM_MAX_NODES,
1892 nn+1)) < O2NM_MAX_NODES) {
1893 if (nn != dlm->node_num && nn != assert->node_idx)
1897 mle->master = assert->node_idx;
1898 atomic_set(&mle->woken, 1);
1900 spin_unlock(&mle->spinlock);
1904 spin_lock(&res->spinlock);
1905 if (mle->type == DLM_MLE_MIGRATION) {
1906 mlog(0, "finishing off migration of lockres %.*s, "
1908 res->lockname.len, res->lockname.name,
1909 dlm->node_num, mle->new_master);
1910 res->state &= ~DLM_LOCK_RES_MIGRATING;
1912 dlm_change_lockres_owner(dlm, res, mle->new_master);
1913 BUG_ON(res->state & DLM_LOCK_RES_DIRTY);
1915 dlm_change_lockres_owner(dlm, res, mle->master);
1917 spin_unlock(&res->spinlock);
1918 have_lockres_ref = 1;
1923 /* master is known, detach if not already detached.
1924 * ensures that only one assert_master call will happen
1926 spin_lock(&dlm->master_lock);
1928 rr = atomic_read(&mle->mle_refs.refcount);
1929 if (mle->inuse > 0) {
1930 if (extra_ref && rr < 3)
1932 else if (!extra_ref && rr < 2)
1935 if (extra_ref && rr < 2)
1937 else if (!extra_ref && rr < 1)
1941 mlog(ML_ERROR, "%s:%.*s: got assert master from %u "
1942 "that will mess up this node, refs=%d, extra=%d, "
1943 "inuse=%d\n", dlm->name, namelen, name,
1944 assert->node_idx, rr, extra_ref, mle->inuse);
1945 dlm_print_one_mle(mle);
1947 __dlm_unlink_mle(dlm, mle);
1948 __dlm_mle_detach_hb_events(dlm, mle);
1951 /* the assert master message now balances the extra
1952 * ref given by the master / migration request message.
1953 * if this is the last put, it will be removed
1957 spin_unlock(&dlm->master_lock);
1959 if (res->owner != assert->node_idx) {
1960 mlog(0, "assert_master from %u, but current "
1961 "owner is %u (%.*s), no mle\n", assert->node_idx,
1962 res->owner, namelen, name);
1965 spin_unlock(&dlm->spinlock);
1970 spin_lock(&res->spinlock);
1971 res->state |= DLM_LOCK_RES_SETREF_INPROG;
1972 spin_unlock(&res->spinlock);
1973 *ret_data = (void *)res;
1976 if (master_request) {
1977 mlog(0, "need to tell master to reassert\n");
1978 /* positive. negative would shoot down the node. */
1979 ret |= DLM_ASSERT_RESPONSE_REASSERT;
1980 if (!have_lockres_ref) {
1981 mlog(ML_ERROR, "strange, got assert from %u, MASTER "
1982 "mle present here for %s:%.*s, but no lockres!\n",
1983 assert->node_idx, dlm->name, namelen, name);
1986 if (have_lockres_ref) {
1987 /* let the master know we have a reference to the lockres */
1988 ret |= DLM_ASSERT_RESPONSE_MASTERY_REF;
1989 mlog(0, "%s:%.*s: got assert from %u, need a ref\n",
1990 dlm->name, namelen, name, assert->node_idx);
1995 /* kill the caller! */
1996 mlog(ML_ERROR, "Bad message received from another node. Dumping state "
1997 "and killing the other node now! This node is OK and can continue.\n");
1998 __dlm_print_one_lock_resource(res);
1999 spin_unlock(&res->spinlock);
2000 spin_unlock(&dlm->spinlock);
2001 *ret_data = (void *)res;
2006 void dlm_assert_master_post_handler(int status, void *data, void *ret_data)
2008 struct dlm_lock_resource *res = (struct dlm_lock_resource *)ret_data;
2011 spin_lock(&res->spinlock);
2012 res->state &= ~DLM_LOCK_RES_SETREF_INPROG;
2013 spin_unlock(&res->spinlock);
2015 dlm_lockres_put(res);
2020 int dlm_dispatch_assert_master(struct dlm_ctxt *dlm,
2021 struct dlm_lock_resource *res,
2022 int ignore_higher, u8 request_from, u32 flags)
2024 struct dlm_work_item *item;
2025 item = kzalloc(sizeof(*item), GFP_NOFS);
2030 /* queue up work for dlm_assert_master_worker */
2031 dlm_grab(dlm); /* get an extra ref for the work item */
2032 dlm_init_work_item(dlm, item, dlm_assert_master_worker, NULL);
2033 item->u.am.lockres = res; /* already have a ref */
2034 /* can optionally ignore node numbers higher than this node */
2035 item->u.am.ignore_higher = ignore_higher;
2036 item->u.am.request_from = request_from;
2037 item->u.am.flags = flags;
2040 mlog(0, "IGNORE HIGHER: %.*s\n", res->lockname.len,
2041 res->lockname.name);
2043 spin_lock(&dlm->work_lock);
2044 list_add_tail(&item->list, &dlm->work_list);
2045 spin_unlock(&dlm->work_lock);
2047 queue_work(dlm->dlm_worker, &dlm->dispatched_work);
2051 static void dlm_assert_master_worker(struct dlm_work_item *item, void *data)
2053 struct dlm_ctxt *dlm = data;
2055 struct dlm_lock_resource *res;
2056 unsigned long nodemap[BITS_TO_LONGS(O2NM_MAX_NODES)];
2063 res = item->u.am.lockres;
2064 ignore_higher = item->u.am.ignore_higher;
2065 request_from = item->u.am.request_from;
2066 flags = item->u.am.flags;
2068 spin_lock(&dlm->spinlock);
2069 memcpy(nodemap, dlm->domain_map, sizeof(nodemap));
2070 spin_unlock(&dlm->spinlock);
2072 clear_bit(dlm->node_num, nodemap);
2073 if (ignore_higher) {
2074 /* if is this just to clear up mles for nodes below
2075 * this node, do not send the message to the original
2076 * caller or any node number higher than this */
2077 clear_bit(request_from, nodemap);
2078 bit = dlm->node_num;
2080 bit = find_next_bit(nodemap, O2NM_MAX_NODES,
2082 if (bit >= O2NM_MAX_NODES)
2084 clear_bit(bit, nodemap);
2089 * If we're migrating this lock to someone else, we are no
2090 * longer allowed to assert out own mastery. OTOH, we need to
2091 * prevent migration from starting while we're still asserting
2092 * our dominance. The reserved ast delays migration.
2094 spin_lock(&res->spinlock);
2095 if (res->state & DLM_LOCK_RES_MIGRATING) {
2096 mlog(0, "Someone asked us to assert mastery, but we're "
2097 "in the middle of migration. Skipping assert, "
2098 "the new master will handle that.\n");
2099 spin_unlock(&res->spinlock);
2102 __dlm_lockres_reserve_ast(res);
2103 spin_unlock(&res->spinlock);
2105 /* this call now finishes out the nodemap
2106 * even if one or more nodes die */
2107 mlog(0, "worker about to master %.*s here, this=%u\n",
2108 res->lockname.len, res->lockname.name, dlm->node_num);
2109 ret = dlm_do_assert_master(dlm, res, nodemap, flags);
2111 /* no need to restart, we are done */
2112 if (!dlm_is_host_down(ret))
2116 /* Ok, we've asserted ourselves. Let's let migration start. */
2117 dlm_lockres_release_ast(dlm, res);
2120 dlm_lockres_put(res);
2122 mlog(0, "finished with dlm_assert_master_worker\n");
2125 /* SPECIAL CASE for the $RECOVERY lock used by the recovery thread.
2126 * We cannot wait for node recovery to complete to begin mastering this
2127 * lockres because this lockres is used to kick off recovery! ;-)
2128 * So, do a pre-check on all living nodes to see if any of those nodes
2129 * think that $RECOVERY is currently mastered by a dead node. If so,
2130 * we wait a short time to allow that node to get notified by its own
2131 * heartbeat stack, then check again. All $RECOVERY lock resources
2132 * mastered by dead nodes are purged when the hearbeat callback is
2133 * fired, so we can know for sure that it is safe to continue once
2134 * the node returns a live node or no node. */
2135 static int dlm_pre_master_reco_lockres(struct dlm_ctxt *dlm,
2136 struct dlm_lock_resource *res)
2138 struct dlm_node_iter iter;
2141 u8 master = DLM_LOCK_RES_OWNER_UNKNOWN;
2143 spin_lock(&dlm->spinlock);
2144 dlm_node_iter_init(dlm->domain_map, &iter);
2145 spin_unlock(&dlm->spinlock);
2147 while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2148 /* do not send to self */
2149 if (nodenum == dlm->node_num)
2151 ret = dlm_do_master_requery(dlm, res, nodenum, &master);
2154 if (!dlm_is_host_down(ret))
2156 /* host is down, so answer for that node would be
2157 * DLM_LOCK_RES_OWNER_UNKNOWN. continue. */
2161 if (master != DLM_LOCK_RES_OWNER_UNKNOWN) {
2162 /* check to see if this master is in the recovery map */
2163 spin_lock(&dlm->spinlock);
2164 if (test_bit(master, dlm->recovery_map)) {
2165 mlog(ML_NOTICE, "%s: node %u has not seen "
2166 "node %u go down yet, and thinks the "
2167 "dead node is mastering the recovery "
2168 "lock. must wait.\n", dlm->name,
2172 spin_unlock(&dlm->spinlock);
2173 mlog(0, "%s: reco lock master is %u\n", dlm->name,
2182 * DLM_DEREF_LOCKRES_MSG
2185 int dlm_drop_lockres_ref(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
2187 struct dlm_deref_lockres deref;
2189 const char *lockname;
2190 unsigned int namelen;
2192 lockname = res->lockname.name;
2193 namelen = res->lockname.len;
2194 BUG_ON(namelen > O2NM_MAX_NAME_LEN);
2196 mlog(0, "%s:%.*s: sending deref to %d\n",
2197 dlm->name, namelen, lockname, res->owner);
2198 memset(&deref, 0, sizeof(deref));
2199 deref.node_idx = dlm->node_num;
2200 deref.namelen = namelen;
2201 memcpy(deref.name, lockname, namelen);
2203 ret = o2net_send_message(DLM_DEREF_LOCKRES_MSG, dlm->key,
2204 &deref, sizeof(deref), res->owner, &r);
2206 mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
2207 "node %u\n", ret, DLM_DEREF_LOCKRES_MSG, dlm->key,
2210 /* BAD. other node says I did not have a ref. */
2211 mlog(ML_ERROR,"while dropping ref on %s:%.*s "
2212 "(master=%u) got %d.\n", dlm->name, namelen,
2213 lockname, res->owner, r);
2214 dlm_print_one_lock_resource(res);
2220 int dlm_deref_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
2223 struct dlm_ctxt *dlm = data;
2224 struct dlm_deref_lockres *deref = (struct dlm_deref_lockres *)msg->buf;
2225 struct dlm_lock_resource *res = NULL;
2227 unsigned int namelen;
2231 struct dlm_work_item *item;
2239 namelen = deref->namelen;
2240 node = deref->node_idx;
2242 if (namelen > DLM_LOCKID_NAME_MAX) {
2243 mlog(ML_ERROR, "Invalid name length!");
2246 if (deref->node_idx >= O2NM_MAX_NODES) {
2247 mlog(ML_ERROR, "Invalid node number: %u\n", node);
2251 hash = dlm_lockid_hash(name, namelen);
2253 spin_lock(&dlm->spinlock);
2254 res = __dlm_lookup_lockres_full(dlm, name, namelen, hash);
2256 spin_unlock(&dlm->spinlock);
2257 mlog(ML_ERROR, "%s:%.*s: bad lockres name\n",
2258 dlm->name, namelen, name);
2261 spin_unlock(&dlm->spinlock);
2263 spin_lock(&res->spinlock);
2264 if (res->state & DLM_LOCK_RES_SETREF_INPROG)
2267 BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF);
2268 if (test_bit(node, res->refmap)) {
2269 dlm_lockres_clear_refmap_bit(node, res);
2273 spin_unlock(&res->spinlock);
2277 dlm_lockres_calc_usage(dlm, res);
2279 mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref "
2280 "but it is already dropped!\n", dlm->name,
2281 res->lockname.len, res->lockname.name, node);
2282 dlm_print_one_lock_resource(res);
2288 item = kzalloc(sizeof(*item), GFP_NOFS);
2295 dlm_init_work_item(dlm, item, dlm_deref_lockres_worker, NULL);
2296 item->u.dl.deref_res = res;
2297 item->u.dl.deref_node = node;
2299 spin_lock(&dlm->work_lock);
2300 list_add_tail(&item->list, &dlm->work_list);
2301 spin_unlock(&dlm->work_lock);
2303 queue_work(dlm->dlm_worker, &dlm->dispatched_work);
2308 dlm_lockres_put(res);
2314 static void dlm_deref_lockres_worker(struct dlm_work_item *item, void *data)
2316 struct dlm_ctxt *dlm;
2317 struct dlm_lock_resource *res;
2322 res = item->u.dl.deref_res;
2323 node = item->u.dl.deref_node;
2325 spin_lock(&res->spinlock);
2326 BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF);
2327 if (test_bit(node, res->refmap)) {
2328 __dlm_wait_on_lockres_flags(res, DLM_LOCK_RES_SETREF_INPROG);
2329 dlm_lockres_clear_refmap_bit(node, res);
2332 spin_unlock(&res->spinlock);
2335 mlog(0, "%s:%.*s node %u ref dropped in dispatch\n",
2336 dlm->name, res->lockname.len, res->lockname.name, node);
2337 dlm_lockres_calc_usage(dlm, res);
2339 mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref "
2340 "but it is already dropped!\n", dlm->name,
2341 res->lockname.len, res->lockname.name, node);
2342 dlm_print_one_lock_resource(res);
2345 dlm_lockres_put(res);
2348 /* Checks whether the lockres can be migrated. Returns 0 if yes, < 0
2349 * if not. If 0, numlocks is set to the number of locks in the lockres.
2351 static int dlm_is_lockres_migrateable(struct dlm_ctxt *dlm,
2352 struct dlm_lock_resource *res,
2358 struct list_head *queue;
2359 struct dlm_lock *lock;
2361 assert_spin_locked(&res->spinlock);
2364 if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
2365 mlog(0, "cannot migrate lockres with unknown owner!\n");
2369 if (res->owner != dlm->node_num) {
2370 mlog(0, "cannot migrate lockres this node doesn't own!\n");
2375 queue = &res->granted;
2376 for (i = 0; i < 3; i++) {
2377 list_for_each_entry(lock, queue, list) {
2379 if (lock->ml.node == dlm->node_num) {
2380 mlog(0, "found a lock owned by this node still "
2381 "on the %s queue! will not migrate this "
2382 "lockres\n", (i == 0 ? "granted" :
2383 (i == 1 ? "converting" :
2393 mlog(0, "migrateable lockres having %d locks\n", *numlocks);
2400 * DLM_MIGRATE_LOCKRES
2404 static int dlm_migrate_lockres(struct dlm_ctxt *dlm,
2405 struct dlm_lock_resource *res,
2408 struct dlm_master_list_entry *mle = NULL;
2409 struct dlm_master_list_entry *oldmle = NULL;
2410 struct dlm_migratable_lockres *mres = NULL;
2413 unsigned int namelen;
2421 name = res->lockname.name;
2422 namelen = res->lockname.len;
2424 mlog(0, "migrating %.*s to %u\n", namelen, name, target);
2427 * ensure this lockres is a proper candidate for migration
2429 spin_lock(&res->spinlock);
2430 ret = dlm_is_lockres_migrateable(dlm, res, &numlocks);
2432 spin_unlock(&res->spinlock);
2435 spin_unlock(&res->spinlock);
2438 if (numlocks == 0) {
2439 mlog(0, "no locks were found on this lockres! done!\n");
2444 * preallocate up front
2445 * if this fails, abort
2449 mres = (struct dlm_migratable_lockres *) __get_free_page(GFP_NOFS);
2455 mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
2463 * find a node to migrate the lockres to
2466 mlog(0, "picking a migration node\n");
2467 spin_lock(&dlm->spinlock);
2468 /* pick a new node */
2469 if (!test_bit(target, dlm->domain_map) ||
2470 target >= O2NM_MAX_NODES) {
2471 target = dlm_pick_migration_target(dlm, res);
2473 mlog(0, "node %u chosen for migration\n", target);
2475 if (target >= O2NM_MAX_NODES ||
2476 !test_bit(target, dlm->domain_map)) {
2477 /* target chosen is not alive */
2482 spin_unlock(&dlm->spinlock);
2486 mlog(0, "continuing with target = %u\n", target);
2489 * clear any existing master requests and
2490 * add the migration mle to the list
2492 spin_lock(&dlm->master_lock);
2493 ret = dlm_add_migration_mle(dlm, res, mle, &oldmle, name,
2494 namelen, target, dlm->node_num);
2495 spin_unlock(&dlm->master_lock);
2496 spin_unlock(&dlm->spinlock);
2498 if (ret == -EEXIST) {
2499 mlog(0, "another process is already migrating it\n");
2505 * set the MIGRATING flag and flush asts
2506 * if we fail after this we need to re-dirty the lockres
2508 if (dlm_mark_lockres_migrating(dlm, res, target) < 0) {
2509 mlog(ML_ERROR, "tried to migrate %.*s to %u, but "
2510 "the target went down.\n", res->lockname.len,
2511 res->lockname.name, target);
2512 spin_lock(&res->spinlock);
2513 res->state &= ~DLM_LOCK_RES_MIGRATING;
2515 spin_unlock(&res->spinlock);
2521 /* master is known, detach if not already detached */
2522 dlm_mle_detach_hb_events(dlm, oldmle);
2523 dlm_put_mle(oldmle);
2528 dlm_mle_detach_hb_events(dlm, mle);
2531 kmem_cache_free(dlm_mle_cache, mle);
2537 * at this point, we have a migration target, an mle
2538 * in the master list, and the MIGRATING flag set on
2542 /* now that remote nodes are spinning on the MIGRATING flag,
2543 * ensure that all assert_master work is flushed. */
2544 flush_workqueue(dlm->dlm_worker);
2546 /* get an extra reference on the mle.
2547 * otherwise the assert_master from the new
2548 * master will destroy this.
2549 * also, make sure that all callers of dlm_get_mle
2550 * take both dlm->spinlock and dlm->master_lock */
2551 spin_lock(&dlm->spinlock);
2552 spin_lock(&dlm->master_lock);
2553 dlm_get_mle_inuse(mle);
2554 spin_unlock(&dlm->master_lock);
2555 spin_unlock(&dlm->spinlock);
2557 /* notify new node and send all lock state */
2558 /* call send_one_lockres with migration flag.
2559 * this serves as notice to the target node that a
2560 * migration is starting. */
2561 ret = dlm_send_one_lockres(dlm, res, mres, target,
2562 DLM_MRES_MIGRATION);
2565 mlog(0, "migration to node %u failed with %d\n",
2567 /* migration failed, detach and clean up mle */
2568 dlm_mle_detach_hb_events(dlm, mle);
2570 dlm_put_mle_inuse(mle);
2571 spin_lock(&res->spinlock);
2572 res->state &= ~DLM_LOCK_RES_MIGRATING;
2574 spin_unlock(&res->spinlock);
2578 /* at this point, the target sends a message to all nodes,
2579 * (using dlm_do_migrate_request). this node is skipped since
2580 * we had to put an mle in the list to begin the process. this
2581 * node now waits for target to do an assert master. this node
2582 * will be the last one notified, ensuring that the migration
2583 * is complete everywhere. if the target dies while this is
2584 * going on, some nodes could potentially see the target as the
2585 * master, so it is important that my recovery finds the migration
2586 * mle and sets the master to UNKNOWN. */
2589 /* wait for new node to assert master */
2591 ret = wait_event_interruptible_timeout(mle->wq,
2592 (atomic_read(&mle->woken) == 1),
2593 msecs_to_jiffies(5000));
2596 if (atomic_read(&mle->woken) == 1 ||
2597 res->owner == target)
2600 mlog(0, "%s:%.*s: timed out during migration\n",
2601 dlm->name, res->lockname.len, res->lockname.name);
2602 /* avoid hang during shutdown when migrating lockres
2603 * to a node which also goes down */
2604 if (dlm_is_node_dead(dlm, target)) {
2605 mlog(0, "%s:%.*s: expected migration "
2606 "target %u is no longer up, restarting\n",
2607 dlm->name, res->lockname.len,
2608 res->lockname.name, target);
2610 /* migration failed, detach and clean up mle */
2611 dlm_mle_detach_hb_events(dlm, mle);
2613 dlm_put_mle_inuse(mle);
2614 spin_lock(&res->spinlock);
2615 res->state &= ~DLM_LOCK_RES_MIGRATING;
2617 spin_unlock(&res->spinlock);
2621 mlog(0, "%s:%.*s: caught signal during migration\n",
2622 dlm->name, res->lockname.len, res->lockname.name);
2625 /* all done, set the owner, clear the flag */
2626 spin_lock(&res->spinlock);
2627 dlm_set_lockres_owner(dlm, res, target);
2628 res->state &= ~DLM_LOCK_RES_MIGRATING;
2629 dlm_remove_nonlocal_locks(dlm, res);
2630 spin_unlock(&res->spinlock);
2633 /* master is known, detach if not already detached */
2634 dlm_mle_detach_hb_events(dlm, mle);
2635 dlm_put_mle_inuse(mle);
2638 dlm_lockres_calc_usage(dlm, res);
2641 /* re-dirty the lockres if we failed */
2643 dlm_kick_thread(dlm, res);
2645 /* wake up waiters if the MIGRATING flag got set
2646 * but migration failed */
2652 free_page((unsigned long)mres);
2656 mlog(0, "returning %d\n", ret);
2660 #define DLM_MIGRATION_RETRY_MS 100
2662 /* Should be called only after beginning the domain leave process.
2663 * There should not be any remaining locks on nonlocal lock resources,
2664 * and there should be no local locks left on locally mastered resources.
2666 * Called with the dlm spinlock held, may drop it to do migration, but
2667 * will re-acquire before exit.
2669 * Returns: 1 if dlm->spinlock was dropped/retaken, 0 if never dropped */
2670 int dlm_empty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
2673 int lock_dropped = 0;
2676 spin_lock(&res->spinlock);
2677 if (res->owner != dlm->node_num) {
2678 if (!__dlm_lockres_unused(res)) {
2679 mlog(ML_ERROR, "%s:%.*s: this node is not master, "
2680 "trying to free this but locks remain\n",
2681 dlm->name, res->lockname.len, res->lockname.name);
2683 spin_unlock(&res->spinlock);
2687 /* No need to migrate a lockres having no locks */
2688 ret = dlm_is_lockres_migrateable(dlm, res, &numlocks);
2689 if (ret >= 0 && numlocks == 0) {
2690 spin_unlock(&res->spinlock);
2693 spin_unlock(&res->spinlock);
2695 /* Wheee! Migrate lockres here! Will sleep so drop spinlock. */
2696 spin_unlock(&dlm->spinlock);
2699 ret = dlm_migrate_lockres(dlm, res, O2NM_MAX_NODES);
2702 if (ret == -ENOTEMPTY) {
2703 mlog(ML_ERROR, "lockres %.*s still has local locks!\n",
2704 res->lockname.len, res->lockname.name);
2708 mlog(0, "lockres %.*s: migrate failed, "
2709 "retrying\n", res->lockname.len,
2710 res->lockname.name);
2711 msleep(DLM_MIGRATION_RETRY_MS);
2713 spin_lock(&dlm->spinlock);
2715 return lock_dropped;
2718 int dlm_lock_basts_flushed(struct dlm_ctxt *dlm, struct dlm_lock *lock)
2721 spin_lock(&dlm->ast_lock);
2722 spin_lock(&lock->spinlock);
2723 ret = (list_empty(&lock->bast_list) && !lock->bast_pending);
2724 spin_unlock(&lock->spinlock);
2725 spin_unlock(&dlm->ast_lock);
2729 static int dlm_migration_can_proceed(struct dlm_ctxt *dlm,
2730 struct dlm_lock_resource *res,
2734 spin_lock(&res->spinlock);
2735 can_proceed = !!(res->state & DLM_LOCK_RES_MIGRATING);
2736 spin_unlock(&res->spinlock);
2738 /* target has died, so make the caller break out of the
2739 * wait_event, but caller must recheck the domain_map */
2740 spin_lock(&dlm->spinlock);
2741 if (!test_bit(mig_target, dlm->domain_map))
2743 spin_unlock(&dlm->spinlock);
2747 static int dlm_lockres_is_dirty(struct dlm_ctxt *dlm,
2748 struct dlm_lock_resource *res)
2751 spin_lock(&res->spinlock);
2752 ret = !!(res->state & DLM_LOCK_RES_DIRTY);
2753 spin_unlock(&res->spinlock);
2758 static int dlm_mark_lockres_migrating(struct dlm_ctxt *dlm,
2759 struct dlm_lock_resource *res,
2764 mlog(0, "dlm_mark_lockres_migrating: %.*s, from %u to %u\n",
2765 res->lockname.len, res->lockname.name, dlm->node_num,
2767 /* need to set MIGRATING flag on lockres. this is done by
2768 * ensuring that all asts have been flushed for this lockres. */
2769 spin_lock(&res->spinlock);
2770 BUG_ON(res->migration_pending);
2771 res->migration_pending = 1;
2772 /* strategy is to reserve an extra ast then release
2773 * it below, letting the release do all of the work */
2774 __dlm_lockres_reserve_ast(res);
2775 spin_unlock(&res->spinlock);
2777 /* now flush all the pending asts */
2778 dlm_kick_thread(dlm, res);
2779 /* before waiting on DIRTY, block processes which may
2780 * try to dirty the lockres before MIGRATING is set */
2781 spin_lock(&res->spinlock);
2782 BUG_ON(res->state & DLM_LOCK_RES_BLOCK_DIRTY);
2783 res->state |= DLM_LOCK_RES_BLOCK_DIRTY;
2784 spin_unlock(&res->spinlock);
2785 /* now wait on any pending asts and the DIRTY state */
2786 wait_event(dlm->ast_wq, !dlm_lockres_is_dirty(dlm, res));
2787 dlm_lockres_release_ast(dlm, res);
2789 mlog(0, "about to wait on migration_wq, dirty=%s\n",
2790 res->state & DLM_LOCK_RES_DIRTY ? "yes" : "no");
2791 /* if the extra ref we just put was the final one, this
2792 * will pass thru immediately. otherwise, we need to wait
2793 * for the last ast to finish. */
2795 ret = wait_event_interruptible_timeout(dlm->migration_wq,
2796 dlm_migration_can_proceed(dlm, res, target),
2797 msecs_to_jiffies(1000));
2799 mlog(0, "woken again: migrating? %s, dead? %s\n",
2800 res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no",
2801 test_bit(target, dlm->domain_map) ? "no":"yes");
2803 mlog(0, "all is well: migrating? %s, dead? %s\n",
2804 res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no",
2805 test_bit(target, dlm->domain_map) ? "no":"yes");
2807 if (!dlm_migration_can_proceed(dlm, res, target)) {
2808 mlog(0, "trying again...\n");
2811 /* now that we are sure the MIGRATING state is there, drop
2812 * the unneded state which blocked threads trying to DIRTY */
2813 spin_lock(&res->spinlock);
2814 BUG_ON(!(res->state & DLM_LOCK_RES_BLOCK_DIRTY));
2815 BUG_ON(!(res->state & DLM_LOCK_RES_MIGRATING));
2816 res->state &= ~DLM_LOCK_RES_BLOCK_DIRTY;
2817 spin_unlock(&res->spinlock);
2819 /* did the target go down or die? */
2820 spin_lock(&dlm->spinlock);
2821 if (!test_bit(target, dlm->domain_map)) {
2822 mlog(ML_ERROR, "aha. migration target %u just went down\n",
2826 spin_unlock(&dlm->spinlock);
2831 * o the DLM_LOCK_RES_MIGRATING flag is set
2832 * o there are no pending asts on this lockres
2833 * o all processes trying to reserve an ast on this
2834 * lockres must wait for the MIGRATING flag to clear
2839 /* last step in the migration process.
2840 * original master calls this to free all of the dlm_lock
2841 * structures that used to be for other nodes. */
2842 static void dlm_remove_nonlocal_locks(struct dlm_ctxt *dlm,
2843 struct dlm_lock_resource *res)
2845 struct list_head *queue = &res->granted;
2847 struct dlm_lock *lock, *next;
2849 assert_spin_locked(&res->spinlock);
2851 BUG_ON(res->owner == dlm->node_num);
2853 for (i=0; i<3; i++) {
2854 list_for_each_entry_safe(lock, next, queue, list) {
2855 if (lock->ml.node != dlm->node_num) {
2856 mlog(0, "putting lock for node %u\n",
2858 /* be extra careful */
2859 BUG_ON(!list_empty(&lock->ast_list));
2860 BUG_ON(!list_empty(&lock->bast_list));
2861 BUG_ON(lock->ast_pending);
2862 BUG_ON(lock->bast_pending);
2863 dlm_lockres_clear_refmap_bit(lock->ml.node, res);
2864 list_del_init(&lock->list);
2866 /* In a normal unlock, we would have added a
2867 * DLM_UNLOCK_FREE_LOCK action. Force it. */
2875 bit = find_next_bit(res->refmap, O2NM_MAX_NODES, bit);
2876 if (bit >= O2NM_MAX_NODES)
2878 /* do not clear the local node reference, if there is a
2879 * process holding this, let it drop the ref itself */
2880 if (bit != dlm->node_num) {
2881 mlog(0, "%s:%.*s: node %u had a ref to this "
2882 "migrating lockres, clearing\n", dlm->name,
2883 res->lockname.len, res->lockname.name, bit);
2884 dlm_lockres_clear_refmap_bit(bit, res);
2890 /* for now this is not too intelligent. we will
2891 * need stats to make this do the right thing.
2892 * this just finds the first lock on one of the
2893 * queues and uses that node as the target. */
2894 static u8 dlm_pick_migration_target(struct dlm_ctxt *dlm,
2895 struct dlm_lock_resource *res)
2898 struct list_head *queue = &res->granted;
2899 struct dlm_lock *lock;
2902 assert_spin_locked(&dlm->spinlock);
2904 spin_lock(&res->spinlock);
2905 for (i=0; i<3; i++) {
2906 list_for_each_entry(lock, queue, list) {
2907 /* up to the caller to make sure this node
2909 if (lock->ml.node != dlm->node_num) {
2910 spin_unlock(&res->spinlock);
2911 return lock->ml.node;
2916 spin_unlock(&res->spinlock);
2917 mlog(0, "have not found a suitable target yet! checking domain map\n");
2919 /* ok now we're getting desperate. pick anyone alive. */
2922 nodenum = find_next_bit(dlm->domain_map,
2923 O2NM_MAX_NODES, nodenum+1);
2924 mlog(0, "found %d in domain map\n", nodenum);
2925 if (nodenum >= O2NM_MAX_NODES)
2927 if (nodenum != dlm->node_num) {
2928 mlog(0, "picking %d\n", nodenum);
2933 mlog(0, "giving up. no master to migrate to\n");
2934 return DLM_LOCK_RES_OWNER_UNKNOWN;
2939 /* this is called by the new master once all lockres
2940 * data has been received */
2941 static int dlm_do_migrate_request(struct dlm_ctxt *dlm,
2942 struct dlm_lock_resource *res,
2943 u8 master, u8 new_master,
2944 struct dlm_node_iter *iter)
2946 struct dlm_migrate_request migrate;
2947 int ret, skip, status = 0;
2950 memset(&migrate, 0, sizeof(migrate));
2951 migrate.namelen = res->lockname.len;
2952 memcpy(migrate.name, res->lockname.name, migrate.namelen);
2953 migrate.new_master = new_master;
2954 migrate.master = master;
2958 /* send message to all nodes, except the master and myself */
2959 while ((nodenum = dlm_node_iter_next(iter)) >= 0) {
2960 if (nodenum == master ||
2961 nodenum == new_master)
2964 /* We could race exit domain. If exited, skip. */
2965 spin_lock(&dlm->spinlock);
2966 skip = (!test_bit(nodenum, dlm->domain_map));
2967 spin_unlock(&dlm->spinlock);
2969 clear_bit(nodenum, iter->node_map);
2973 ret = o2net_send_message(DLM_MIGRATE_REQUEST_MSG, dlm->key,
2974 &migrate, sizeof(migrate), nodenum,
2977 mlog(ML_ERROR, "Error %d when sending message %u (key "
2978 "0x%x) to node %u\n", ret, DLM_MIGRATE_REQUEST_MSG,
2980 if (!dlm_is_host_down(ret)) {
2981 mlog(ML_ERROR, "unhandled error=%d!\n", ret);
2984 clear_bit(nodenum, iter->node_map);
2986 } else if (status < 0) {
2987 mlog(0, "migrate request (node %u) returned %d!\n",
2990 } else if (status == DLM_MIGRATE_RESPONSE_MASTERY_REF) {
2991 /* during the migration request we short-circuited
2992 * the mastery of the lockres. make sure we have
2993 * a mastery ref for nodenum */
2994 mlog(0, "%s:%.*s: need ref for node %u\n",
2995 dlm->name, res->lockname.len, res->lockname.name,
2997 spin_lock(&res->spinlock);
2998 dlm_lockres_set_refmap_bit(nodenum, res);
2999 spin_unlock(&res->spinlock);
3006 mlog(0, "returning ret=%d\n", ret);
3011 /* if there is an existing mle for this lockres, we now know who the master is.
3012 * (the one who sent us *this* message) we can clear it up right away.
3013 * since the process that put the mle on the list still has a reference to it,
3014 * we can unhash it now, set the master and wake the process. as a result,
3015 * we will have no mle in the list to start with. now we can add an mle for
3016 * the migration and this should be the only one found for those scanning the
3018 int dlm_migrate_request_handler(struct o2net_msg *msg, u32 len, void *data,
3021 struct dlm_ctxt *dlm = data;
3022 struct dlm_lock_resource *res = NULL;
3023 struct dlm_migrate_request *migrate = (struct dlm_migrate_request *) msg->buf;
3024 struct dlm_master_list_entry *mle = NULL, *oldmle = NULL;
3026 unsigned int namelen, hash;
3032 name = migrate->name;
3033 namelen = migrate->namelen;
3034 hash = dlm_lockid_hash(name, namelen);
3036 /* preallocate.. if this fails, abort */
3037 mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
3044 /* check for pre-existing lock */
3045 spin_lock(&dlm->spinlock);
3046 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
3047 spin_lock(&dlm->master_lock);
3050 spin_lock(&res->spinlock);
3051 if (res->state & DLM_LOCK_RES_RECOVERING) {
3052 /* if all is working ok, this can only mean that we got
3053 * a migrate request from a node that we now see as
3054 * dead. what can we do here? drop it to the floor? */
3055 spin_unlock(&res->spinlock);
3056 mlog(ML_ERROR, "Got a migrate request, but the "
3057 "lockres is marked as recovering!");
3058 kmem_cache_free(dlm_mle_cache, mle);
3059 ret = -EINVAL; /* need a better solution */
3062 res->state |= DLM_LOCK_RES_MIGRATING;
3063 spin_unlock(&res->spinlock);
3066 /* ignore status. only nonzero status would BUG. */
3067 ret = dlm_add_migration_mle(dlm, res, mle, &oldmle,
3069 migrate->new_master,
3073 spin_unlock(&dlm->master_lock);
3074 spin_unlock(&dlm->spinlock);
3077 /* master is known, detach if not already detached */
3078 dlm_mle_detach_hb_events(dlm, oldmle);
3079 dlm_put_mle(oldmle);
3083 dlm_lockres_put(res);
3089 /* must be holding dlm->spinlock and dlm->master_lock
3090 * when adding a migration mle, we can clear any other mles
3091 * in the master list because we know with certainty that
3092 * the master is "master". so we remove any old mle from
3093 * the list after setting it's master field, and then add
3094 * the new migration mle. this way we can hold with the rule
3095 * of having only one mle for a given lock name at all times. */
3096 static int dlm_add_migration_mle(struct dlm_ctxt *dlm,
3097 struct dlm_lock_resource *res,
3098 struct dlm_master_list_entry *mle,
3099 struct dlm_master_list_entry **oldmle,
3100 const char *name, unsigned int namelen,
3101 u8 new_master, u8 master)
3110 assert_spin_locked(&dlm->spinlock);
3111 assert_spin_locked(&dlm->master_lock);
3113 /* caller is responsible for any ref taken here on oldmle */
3114 found = dlm_find_mle(dlm, oldmle, (char *)name, namelen);
3116 struct dlm_master_list_entry *tmp = *oldmle;
3117 spin_lock(&tmp->spinlock);
3118 if (tmp->type == DLM_MLE_MIGRATION) {
3119 if (master == dlm->node_num) {
3120 /* ah another process raced me to it */
3121 mlog(0, "tried to migrate %.*s, but some "
3122 "process beat me to it\n",
3126 /* bad. 2 NODES are trying to migrate! */
3127 mlog(ML_ERROR, "migration error mle: "
3128 "master=%u new_master=%u // request: "
3129 "master=%u new_master=%u // "
3131 tmp->master, tmp->new_master,
3137 /* this is essentially what assert_master does */
3138 tmp->master = master;
3139 atomic_set(&tmp->woken, 1);
3141 /* remove it so that only one mle will be found */
3142 __dlm_unlink_mle(dlm, tmp);
3143 __dlm_mle_detach_hb_events(dlm, tmp);
3144 ret = DLM_MIGRATE_RESPONSE_MASTERY_REF;
3145 mlog(0, "%s:%.*s: master=%u, newmaster=%u, "
3146 "telling master to get ref for cleared out mle "
3147 "during migration\n", dlm->name, namelen, name,
3148 master, new_master);
3150 spin_unlock(&tmp->spinlock);
3153 /* now add a migration mle to the tail of the list */
3154 dlm_init_mle(mle, DLM_MLE_MIGRATION, dlm, res, name, namelen);
3155 mle->new_master = new_master;
3156 /* the new master will be sending an assert master for this.
3157 * at that point we will get the refmap reference */
3158 mle->master = master;
3159 /* do this for consistency with other mle types */
3160 set_bit(new_master, mle->maybe_map);
3161 __dlm_insert_mle(dlm, mle);
3167 * Sets the owner of the lockres, associated to the mle, to UNKNOWN
3169 static struct dlm_lock_resource *dlm_reset_mleres_owner(struct dlm_ctxt *dlm,
3170 struct dlm_master_list_entry *mle)
3172 struct dlm_lock_resource *res;
3174 /* Find the lockres associated to the mle and set its owner to UNK */
3175 res = __dlm_lookup_lockres(dlm, mle->mname, mle->mnamelen,
3178 spin_unlock(&dlm->master_lock);
3180 /* move lockres onto recovery list */
3181 spin_lock(&res->spinlock);
3182 dlm_set_lockres_owner(dlm, res, DLM_LOCK_RES_OWNER_UNKNOWN);
3183 dlm_move_lockres_to_recovery_list(dlm, res);
3184 spin_unlock(&res->spinlock);
3185 dlm_lockres_put(res);
3187 /* about to get rid of mle, detach from heartbeat */
3188 __dlm_mle_detach_hb_events(dlm, mle);
3191 spin_lock(&dlm->master_lock);
3193 spin_unlock(&dlm->master_lock);
3199 static void dlm_clean_migration_mle(struct dlm_ctxt *dlm,
3200 struct dlm_master_list_entry *mle)
3202 __dlm_mle_detach_hb_events(dlm, mle);
3204 spin_lock(&mle->spinlock);
3205 __dlm_unlink_mle(dlm, mle);
3206 atomic_set(&mle->woken, 1);
3207 spin_unlock(&mle->spinlock);
3212 static void dlm_clean_block_mle(struct dlm_ctxt *dlm,
3213 struct dlm_master_list_entry *mle, u8 dead_node)
3217 BUG_ON(mle->type != DLM_MLE_BLOCK);
3219 spin_lock(&mle->spinlock);
3220 bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0);
3221 if (bit != dead_node) {
3222 mlog(0, "mle found, but dead node %u would not have been "
3223 "master\n", dead_node);
3224 spin_unlock(&mle->spinlock);
3226 /* Must drop the refcount by one since the assert_master will
3227 * never arrive. This may result in the mle being unlinked and
3228 * freed, but there may still be a process waiting in the
3229 * dlmlock path which is fine. */
3230 mlog(0, "node %u was expected master\n", dead_node);
3231 atomic_set(&mle->woken, 1);
3232 spin_unlock(&mle->spinlock);
3235 /* Do not need events any longer, so detach from heartbeat */
3236 __dlm_mle_detach_hb_events(dlm, mle);
3241 void dlm_clean_master_list(struct dlm_ctxt *dlm, u8 dead_node)
3243 struct dlm_master_list_entry *mle;
3244 struct dlm_lock_resource *res;
3245 struct hlist_head *bucket;
3246 struct hlist_node *list;
3249 mlog_entry("dlm=%s, dead node=%u\n", dlm->name, dead_node);
3251 assert_spin_locked(&dlm->spinlock);
3253 /* clean the master list */
3254 spin_lock(&dlm->master_lock);
3255 for (i = 0; i < DLM_HASH_BUCKETS; i++) {
3256 bucket = dlm_master_hash(dlm, i);
3257 hlist_for_each(list, bucket) {
3258 mle = hlist_entry(list, struct dlm_master_list_entry,
3261 BUG_ON(mle->type != DLM_MLE_BLOCK &&
3262 mle->type != DLM_MLE_MASTER &&
3263 mle->type != DLM_MLE_MIGRATION);
3265 /* MASTER mles are initiated locally. The waiting
3266 * process will notice the node map change shortly.
3267 * Let that happen as normal. */
3268 if (mle->type == DLM_MLE_MASTER)
3271 /* BLOCK mles are initiated by other nodes. Need to
3272 * clean up if the dead node would have been the
3274 if (mle->type == DLM_MLE_BLOCK) {
3275 dlm_clean_block_mle(dlm, mle, dead_node);
3279 /* Everything else is a MIGRATION mle */
3281 /* The rule for MIGRATION mles is that the master
3282 * becomes UNKNOWN if *either* the original or the new
3283 * master dies. All UNKNOWN lockres' are sent to
3284 * whichever node becomes the recovery master. The new
3285 * master is responsible for determining if there is
3286 * still a master for this lockres, or if he needs to
3287 * take over mastery. Either way, this node should
3288 * expect another message to resolve this. */
3290 if (mle->master != dead_node &&
3291 mle->new_master != dead_node)
3294 /* If we have reached this point, this mle needs to be
3295 * removed from the list and freed. */
3296 dlm_clean_migration_mle(dlm, mle);
3298 mlog(0, "%s: node %u died during migration from "
3299 "%u to %u!\n", dlm->name, dead_node, mle->master,
3302 /* If we find a lockres associated with the mle, we've
3303 * hit this rare case that messes up our lock ordering.
3304 * If so, we need to drop the master lock so that we can
3305 * take the lockres lock, meaning that we will have to
3306 * restart from the head of list. */
3307 res = dlm_reset_mleres_owner(dlm, mle);
3312 /* This may be the last reference */
3316 spin_unlock(&dlm->master_lock);
3319 int dlm_finish_migration(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
3322 struct dlm_node_iter iter;
3325 spin_lock(&dlm->spinlock);
3326 dlm_node_iter_init(dlm->domain_map, &iter);
3327 clear_bit(old_master, iter.node_map);
3328 clear_bit(dlm->node_num, iter.node_map);
3329 spin_unlock(&dlm->spinlock);
3331 /* ownership of the lockres is changing. account for the
3332 * mastery reference here since old_master will briefly have
3333 * a reference after the migration completes */
3334 spin_lock(&res->spinlock);
3335 dlm_lockres_set_refmap_bit(old_master, res);
3336 spin_unlock(&res->spinlock);
3338 mlog(0, "now time to do a migrate request to other nodes\n");
3339 ret = dlm_do_migrate_request(dlm, res, old_master,
3340 dlm->node_num, &iter);
3346 mlog(0, "doing assert master of %.*s to all except the original node\n",
3347 res->lockname.len, res->lockname.name);
3348 /* this call now finishes out the nodemap
3349 * even if one or more nodes die */
3350 ret = dlm_do_assert_master(dlm, res, iter.node_map,
3351 DLM_ASSERT_MASTER_FINISH_MIGRATION);
3353 /* no longer need to retry. all living nodes contacted. */
3358 memset(iter.node_map, 0, sizeof(iter.node_map));
3359 set_bit(old_master, iter.node_map);
3360 mlog(0, "doing assert master of %.*s back to %u\n",
3361 res->lockname.len, res->lockname.name, old_master);
3362 ret = dlm_do_assert_master(dlm, res, iter.node_map,
3363 DLM_ASSERT_MASTER_FINISH_MIGRATION);
3365 mlog(0, "assert master to original master failed "
3367 /* the only nonzero status here would be because of
3368 * a dead original node. we're done. */
3372 /* all done, set the owner, clear the flag */
3373 spin_lock(&res->spinlock);
3374 dlm_set_lockres_owner(dlm, res, dlm->node_num);
3375 res->state &= ~DLM_LOCK_RES_MIGRATING;
3376 spin_unlock(&res->spinlock);
3377 /* re-dirty it on the new master */
3378 dlm_kick_thread(dlm, res);
3385 * LOCKRES AST REFCOUNT
3386 * this is integral to migration
3389 /* for future intent to call an ast, reserve one ahead of time.
3390 * this should be called only after waiting on the lockres
3391 * with dlm_wait_on_lockres, and while still holding the
3392 * spinlock after the call. */
3393 void __dlm_lockres_reserve_ast(struct dlm_lock_resource *res)
3395 assert_spin_locked(&res->spinlock);
3396 if (res->state & DLM_LOCK_RES_MIGRATING) {
3397 __dlm_print_one_lock_resource(res);
3399 BUG_ON(res->state & DLM_LOCK_RES_MIGRATING);
3401 atomic_inc(&res->asts_reserved);
3405 * used to drop the reserved ast, either because it went unused,
3406 * or because the ast/bast was actually called.
3408 * also, if there is a pending migration on this lockres,
3409 * and this was the last pending ast on the lockres,
3410 * atomically set the MIGRATING flag before we drop the lock.
3411 * this is how we ensure that migration can proceed with no
3412 * asts in progress. note that it is ok if the state of the
3413 * queues is such that a lock should be granted in the future
3414 * or that a bast should be fired, because the new master will
3415 * shuffle the lists on this lockres as soon as it is migrated.
3417 void dlm_lockres_release_ast(struct dlm_ctxt *dlm,
3418 struct dlm_lock_resource *res)
3420 if (!atomic_dec_and_lock(&res->asts_reserved, &res->spinlock))
3423 if (!res->migration_pending) {
3424 spin_unlock(&res->spinlock);
3428 BUG_ON(res->state & DLM_LOCK_RES_MIGRATING);
3429 res->migration_pending = 0;
3430 res->state |= DLM_LOCK_RES_MIGRATING;
3431 spin_unlock(&res->spinlock);
3433 wake_up(&dlm->migration_wq);