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/utsname.h>
34 #include <linux/init.h>
35 #include <linux/sysctl.h>
36 #include <linux/random.h>
37 #include <linux/blkdev.h>
38 #include <linux/socket.h>
39 #include <linux/inet.h>
40 #include <linux/spinlock.h>
41 #include <linux/delay.h>
44 #include "cluster/heartbeat.h"
45 #include "cluster/nodemanager.h"
46 #include "cluster/tcp.h"
49 #include "dlmcommon.h"
50 #include "dlmdomain.h"
53 #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_MASTER)
54 #include "cluster/masklog.h"
56 static void dlm_mle_node_down(struct dlm_ctxt
*dlm
,
57 struct dlm_master_list_entry
*mle
,
58 struct o2nm_node
*node
,
60 static void dlm_mle_node_up(struct dlm_ctxt
*dlm
,
61 struct dlm_master_list_entry
*mle
,
62 struct o2nm_node
*node
,
65 static void dlm_assert_master_worker(struct dlm_work_item
*item
, void *data
);
66 static int dlm_do_assert_master(struct dlm_ctxt
*dlm
,
67 struct dlm_lock_resource
*res
,
68 void *nodemap
, u32 flags
);
69 static void dlm_deref_lockres_worker(struct dlm_work_item
*item
, void *data
);
71 static inline void __dlm_mle_name(struct dlm_master_list_entry
*mle
,
72 unsigned char **name
, unsigned int *namelen
)
74 BUG_ON(mle
->type
!= DLM_MLE_BLOCK
&&
75 mle
->type
!= DLM_MLE_MASTER
&&
76 mle
->type
!= DLM_MLE_MIGRATION
);
78 if (mle
->type
!= DLM_MLE_MASTER
) {
79 *name
= mle
->u
.mlename
.name
;
80 *namelen
= mle
->u
.mlename
.len
;
82 *name
= (unsigned char *)mle
->u
.mleres
->lockname
.name
;
83 *namelen
= mle
->u
.mleres
->lockname
.len
;
87 static inline int dlm_mle_equal(struct dlm_ctxt
*dlm
,
88 struct dlm_master_list_entry
*mle
,
92 unsigned char *mlename
;
98 __dlm_mle_name(mle
, &mlename
, &mlelen
);
100 if (namelen
!= mlelen
|| memcmp(name
, mlename
, namelen
) != 0)
106 static struct kmem_cache
*dlm_lockres_cache
= NULL
;
107 static struct kmem_cache
*dlm_lockname_cache
= NULL
;
108 static struct kmem_cache
*dlm_mle_cache
= NULL
;
110 static void dlm_mle_release(struct kref
*kref
);
111 static void dlm_init_mle(struct dlm_master_list_entry
*mle
,
112 enum dlm_mle_type type
,
113 struct dlm_ctxt
*dlm
,
114 struct dlm_lock_resource
*res
,
116 unsigned int namelen
);
117 static void dlm_put_mle(struct dlm_master_list_entry
*mle
);
118 static void __dlm_put_mle(struct dlm_master_list_entry
*mle
);
119 static int dlm_find_mle(struct dlm_ctxt
*dlm
,
120 struct dlm_master_list_entry
**mle
,
121 char *name
, unsigned int namelen
);
123 static int dlm_do_master_request(struct dlm_lock_resource
*res
,
124 struct dlm_master_list_entry
*mle
, int to
);
127 static int dlm_wait_for_lock_mastery(struct dlm_ctxt
*dlm
,
128 struct dlm_lock_resource
*res
,
129 struct dlm_master_list_entry
*mle
,
131 static int dlm_restart_lock_mastery(struct dlm_ctxt
*dlm
,
132 struct dlm_lock_resource
*res
,
133 struct dlm_master_list_entry
*mle
,
135 static int dlm_add_migration_mle(struct dlm_ctxt
*dlm
,
136 struct dlm_lock_resource
*res
,
137 struct dlm_master_list_entry
*mle
,
138 struct dlm_master_list_entry
**oldmle
,
139 const char *name
, unsigned int namelen
,
140 u8 new_master
, u8 master
);
142 static u8
dlm_pick_migration_target(struct dlm_ctxt
*dlm
,
143 struct dlm_lock_resource
*res
);
144 static void dlm_remove_nonlocal_locks(struct dlm_ctxt
*dlm
,
145 struct dlm_lock_resource
*res
);
146 static int dlm_mark_lockres_migrating(struct dlm_ctxt
*dlm
,
147 struct dlm_lock_resource
*res
,
149 static int dlm_pre_master_reco_lockres(struct dlm_ctxt
*dlm
,
150 struct dlm_lock_resource
*res
);
153 int dlm_is_host_down(int errno
)
170 case -EINVAL
: /* if returned from our tcp code,
171 this means there is no socket */
179 * MASTER LIST FUNCTIONS
184 * regarding master list entries and heartbeat callbacks:
186 * in order to avoid sleeping and allocation that occurs in
187 * heartbeat, master list entries are simply attached to the
188 * dlm's established heartbeat callbacks. the mle is attached
189 * when it is created, and since the dlm->spinlock is held at
190 * that time, any heartbeat event will be properly discovered
191 * by the mle. the mle needs to be detached from the
192 * dlm->mle_hb_events list as soon as heartbeat events are no
193 * longer useful to the mle, and before the mle is freed.
195 * as a general rule, heartbeat events are no longer needed by
196 * the mle once an "answer" regarding the lock master has been
199 static inline void __dlm_mle_attach_hb_events(struct dlm_ctxt
*dlm
,
200 struct dlm_master_list_entry
*mle
)
202 assert_spin_locked(&dlm
->spinlock
);
204 list_add_tail(&mle
->hb_events
, &dlm
->mle_hb_events
);
208 static inline void __dlm_mle_detach_hb_events(struct dlm_ctxt
*dlm
,
209 struct dlm_master_list_entry
*mle
)
211 if (!list_empty(&mle
->hb_events
))
212 list_del_init(&mle
->hb_events
);
216 static inline void dlm_mle_detach_hb_events(struct dlm_ctxt
*dlm
,
217 struct dlm_master_list_entry
*mle
)
219 spin_lock(&dlm
->spinlock
);
220 __dlm_mle_detach_hb_events(dlm
, mle
);
221 spin_unlock(&dlm
->spinlock
);
224 static void dlm_get_mle_inuse(struct dlm_master_list_entry
*mle
)
226 struct dlm_ctxt
*dlm
;
229 assert_spin_locked(&dlm
->spinlock
);
230 assert_spin_locked(&dlm
->master_lock
);
232 kref_get(&mle
->mle_refs
);
235 static void dlm_put_mle_inuse(struct dlm_master_list_entry
*mle
)
237 struct dlm_ctxt
*dlm
;
240 spin_lock(&dlm
->spinlock
);
241 spin_lock(&dlm
->master_lock
);
244 spin_unlock(&dlm
->master_lock
);
245 spin_unlock(&dlm
->spinlock
);
249 /* remove from list and free */
250 static void __dlm_put_mle(struct dlm_master_list_entry
*mle
)
252 struct dlm_ctxt
*dlm
;
255 assert_spin_locked(&dlm
->spinlock
);
256 assert_spin_locked(&dlm
->master_lock
);
257 if (!atomic_read(&mle
->mle_refs
.refcount
)) {
258 /* this may or may not crash, but who cares.
260 mlog(ML_ERROR
, "bad mle: %p\n", mle
);
261 dlm_print_one_mle(mle
);
264 kref_put(&mle
->mle_refs
, dlm_mle_release
);
268 /* must not have any spinlocks coming in */
269 static void dlm_put_mle(struct dlm_master_list_entry
*mle
)
271 struct dlm_ctxt
*dlm
;
274 spin_lock(&dlm
->spinlock
);
275 spin_lock(&dlm
->master_lock
);
277 spin_unlock(&dlm
->master_lock
);
278 spin_unlock(&dlm
->spinlock
);
281 static inline void dlm_get_mle(struct dlm_master_list_entry
*mle
)
283 kref_get(&mle
->mle_refs
);
286 static void dlm_init_mle(struct dlm_master_list_entry
*mle
,
287 enum dlm_mle_type type
,
288 struct dlm_ctxt
*dlm
,
289 struct dlm_lock_resource
*res
,
291 unsigned int namelen
)
293 assert_spin_locked(&dlm
->spinlock
);
297 INIT_LIST_HEAD(&mle
->list
);
298 INIT_LIST_HEAD(&mle
->hb_events
);
299 memset(mle
->maybe_map
, 0, sizeof(mle
->maybe_map
));
300 spin_lock_init(&mle
->spinlock
);
301 init_waitqueue_head(&mle
->wq
);
302 atomic_set(&mle
->woken
, 0);
303 kref_init(&mle
->mle_refs
);
304 memset(mle
->response_map
, 0, sizeof(mle
->response_map
));
305 mle
->master
= O2NM_MAX_NODES
;
306 mle
->new_master
= O2NM_MAX_NODES
;
309 BUG_ON(mle
->type
!= DLM_MLE_BLOCK
&&
310 mle
->type
!= DLM_MLE_MASTER
&&
311 mle
->type
!= DLM_MLE_MIGRATION
);
313 if (mle
->type
== DLM_MLE_MASTER
) {
318 memcpy(mle
->u
.mlename
.name
, name
, namelen
);
319 mle
->u
.mlename
.len
= namelen
;
322 /* copy off the node_map and register hb callbacks on our copy */
323 memcpy(mle
->node_map
, dlm
->domain_map
, sizeof(mle
->node_map
));
324 memcpy(mle
->vote_map
, dlm
->domain_map
, sizeof(mle
->vote_map
));
325 clear_bit(dlm
->node_num
, mle
->vote_map
);
326 clear_bit(dlm
->node_num
, mle
->node_map
);
328 /* attach the mle to the domain node up/down events */
329 __dlm_mle_attach_hb_events(dlm
, mle
);
332 void __dlm_unlink_mle(struct dlm_ctxt
*dlm
, struct dlm_master_list_entry
*mle
)
334 assert_spin_locked(&dlm
->spinlock
);
335 assert_spin_locked(&dlm
->master_lock
);
337 if (!list_empty(&mle
->list
))
338 list_del_init(&mle
->list
);
341 void __dlm_insert_mle(struct dlm_ctxt
*dlm
, struct dlm_master_list_entry
*mle
)
343 assert_spin_locked(&dlm
->master_lock
);
345 list_add(&mle
->list
, &dlm
->master_list
);
348 /* returns 1 if found, 0 if not */
349 static int dlm_find_mle(struct dlm_ctxt
*dlm
,
350 struct dlm_master_list_entry
**mle
,
351 char *name
, unsigned int namelen
)
353 struct dlm_master_list_entry
*tmpmle
;
355 assert_spin_locked(&dlm
->master_lock
);
357 list_for_each_entry(tmpmle
, &dlm
->master_list
, list
) {
358 if (!dlm_mle_equal(dlm
, tmpmle
, name
, namelen
))
367 void dlm_hb_event_notify_attached(struct dlm_ctxt
*dlm
, int idx
, int node_up
)
369 struct dlm_master_list_entry
*mle
;
371 assert_spin_locked(&dlm
->spinlock
);
373 list_for_each_entry(mle
, &dlm
->mle_hb_events
, hb_events
) {
375 dlm_mle_node_up(dlm
, mle
, NULL
, idx
);
377 dlm_mle_node_down(dlm
, mle
, NULL
, idx
);
381 static void dlm_mle_node_down(struct dlm_ctxt
*dlm
,
382 struct dlm_master_list_entry
*mle
,
383 struct o2nm_node
*node
, int idx
)
385 spin_lock(&mle
->spinlock
);
387 if (!test_bit(idx
, mle
->node_map
))
388 mlog(0, "node %u already removed from nodemap!\n", idx
);
390 clear_bit(idx
, mle
->node_map
);
392 spin_unlock(&mle
->spinlock
);
395 static void dlm_mle_node_up(struct dlm_ctxt
*dlm
,
396 struct dlm_master_list_entry
*mle
,
397 struct o2nm_node
*node
, int idx
)
399 spin_lock(&mle
->spinlock
);
401 if (test_bit(idx
, mle
->node_map
))
402 mlog(0, "node %u already in node map!\n", idx
);
404 set_bit(idx
, mle
->node_map
);
406 spin_unlock(&mle
->spinlock
);
410 int dlm_init_mle_cache(void)
412 dlm_mle_cache
= kmem_cache_create("o2dlm_mle",
413 sizeof(struct dlm_master_list_entry
),
414 0, SLAB_HWCACHE_ALIGN
,
416 if (dlm_mle_cache
== NULL
)
421 void dlm_destroy_mle_cache(void)
424 kmem_cache_destroy(dlm_mle_cache
);
427 static void dlm_mle_release(struct kref
*kref
)
429 struct dlm_master_list_entry
*mle
;
430 struct dlm_ctxt
*dlm
;
434 mle
= container_of(kref
, struct dlm_master_list_entry
, mle_refs
);
437 if (mle
->type
!= DLM_MLE_MASTER
) {
438 mlog(0, "calling mle_release for %.*s, type %d\n",
439 mle
->u
.mlename
.len
, mle
->u
.mlename
.name
, mle
->type
);
441 mlog(0, "calling mle_release for %.*s, type %d\n",
442 mle
->u
.mleres
->lockname
.len
,
443 mle
->u
.mleres
->lockname
.name
, mle
->type
);
445 assert_spin_locked(&dlm
->spinlock
);
446 assert_spin_locked(&dlm
->master_lock
);
448 /* remove from list if not already */
449 __dlm_unlink_mle(dlm
, mle
);
451 /* detach the mle from the domain node up/down events */
452 __dlm_mle_detach_hb_events(dlm
, mle
);
454 /* NOTE: kfree under spinlock here.
455 * if this is bad, we can move this to a freelist. */
456 kmem_cache_free(dlm_mle_cache
, mle
);
461 * LOCK RESOURCE FUNCTIONS
464 int dlm_init_master_caches(void)
466 dlm_lockres_cache
= kmem_cache_create("o2dlm_lockres",
467 sizeof(struct dlm_lock_resource
),
468 0, SLAB_HWCACHE_ALIGN
, NULL
);
469 if (!dlm_lockres_cache
)
472 dlm_lockname_cache
= kmem_cache_create("o2dlm_lockname",
473 DLM_LOCKID_NAME_MAX
, 0,
474 SLAB_HWCACHE_ALIGN
, NULL
);
475 if (!dlm_lockname_cache
)
480 dlm_destroy_master_caches();
484 void dlm_destroy_master_caches(void)
486 if (dlm_lockname_cache
)
487 kmem_cache_destroy(dlm_lockname_cache
);
489 if (dlm_lockres_cache
)
490 kmem_cache_destroy(dlm_lockres_cache
);
493 static void dlm_set_lockres_owner(struct dlm_ctxt
*dlm
,
494 struct dlm_lock_resource
*res
,
497 assert_spin_locked(&res
->spinlock
);
499 mlog_entry("%.*s, %u\n", res
->lockname
.len
, res
->lockname
.name
, owner
);
501 if (owner
== dlm
->node_num
)
502 atomic_inc(&dlm
->local_resources
);
503 else if (owner
== DLM_LOCK_RES_OWNER_UNKNOWN
)
504 atomic_inc(&dlm
->unknown_resources
);
506 atomic_inc(&dlm
->remote_resources
);
511 void dlm_change_lockres_owner(struct dlm_ctxt
*dlm
,
512 struct dlm_lock_resource
*res
, u8 owner
)
514 assert_spin_locked(&res
->spinlock
);
516 if (owner
== res
->owner
)
519 if (res
->owner
== dlm
->node_num
)
520 atomic_dec(&dlm
->local_resources
);
521 else if (res
->owner
== DLM_LOCK_RES_OWNER_UNKNOWN
)
522 atomic_dec(&dlm
->unknown_resources
);
524 atomic_dec(&dlm
->remote_resources
);
526 dlm_set_lockres_owner(dlm
, res
, owner
);
530 static void dlm_lockres_release(struct kref
*kref
)
532 struct dlm_lock_resource
*res
;
533 struct dlm_ctxt
*dlm
;
535 res
= container_of(kref
, struct dlm_lock_resource
, refs
);
538 /* This should not happen -- all lockres' have a name
539 * associated with them at init time. */
540 BUG_ON(!res
->lockname
.name
);
542 mlog(0, "destroying lockres %.*s\n", res
->lockname
.len
,
545 spin_lock(&dlm
->track_lock
);
546 if (!list_empty(&res
->tracking
))
547 list_del_init(&res
->tracking
);
549 mlog(ML_ERROR
, "Resource %.*s not on the Tracking list\n",
550 res
->lockname
.len
, res
->lockname
.name
);
551 dlm_print_one_lock_resource(res
);
553 spin_unlock(&dlm
->track_lock
);
557 if (!hlist_unhashed(&res
->hash_node
) ||
558 !list_empty(&res
->granted
) ||
559 !list_empty(&res
->converting
) ||
560 !list_empty(&res
->blocked
) ||
561 !list_empty(&res
->dirty
) ||
562 !list_empty(&res
->recovering
) ||
563 !list_empty(&res
->purge
)) {
565 "Going to BUG for resource %.*s."
566 " We're on a list! [%c%c%c%c%c%c%c]\n",
567 res
->lockname
.len
, res
->lockname
.name
,
568 !hlist_unhashed(&res
->hash_node
) ? 'H' : ' ',
569 !list_empty(&res
->granted
) ? 'G' : ' ',
570 !list_empty(&res
->converting
) ? 'C' : ' ',
571 !list_empty(&res
->blocked
) ? 'B' : ' ',
572 !list_empty(&res
->dirty
) ? 'D' : ' ',
573 !list_empty(&res
->recovering
) ? 'R' : ' ',
574 !list_empty(&res
->purge
) ? 'P' : ' ');
576 dlm_print_one_lock_resource(res
);
579 /* By the time we're ready to blow this guy away, we shouldn't
580 * be on any lists. */
581 BUG_ON(!hlist_unhashed(&res
->hash_node
));
582 BUG_ON(!list_empty(&res
->granted
));
583 BUG_ON(!list_empty(&res
->converting
));
584 BUG_ON(!list_empty(&res
->blocked
));
585 BUG_ON(!list_empty(&res
->dirty
));
586 BUG_ON(!list_empty(&res
->recovering
));
587 BUG_ON(!list_empty(&res
->purge
));
589 kmem_cache_free(dlm_lockname_cache
, (void *)res
->lockname
.name
);
591 kmem_cache_free(dlm_lockres_cache
, res
);
594 void dlm_lockres_put(struct dlm_lock_resource
*res
)
596 kref_put(&res
->refs
, dlm_lockres_release
);
599 static void dlm_init_lockres(struct dlm_ctxt
*dlm
,
600 struct dlm_lock_resource
*res
,
601 const char *name
, unsigned int namelen
)
605 /* If we memset here, we lose our reference to the kmalloc'd
606 * res->lockname.name, so be sure to init every field
609 qname
= (char *) res
->lockname
.name
;
610 memcpy(qname
, name
, namelen
);
612 res
->lockname
.len
= namelen
;
613 res
->lockname
.hash
= dlm_lockid_hash(name
, namelen
);
615 init_waitqueue_head(&res
->wq
);
616 spin_lock_init(&res
->spinlock
);
617 INIT_HLIST_NODE(&res
->hash_node
);
618 INIT_LIST_HEAD(&res
->granted
);
619 INIT_LIST_HEAD(&res
->converting
);
620 INIT_LIST_HEAD(&res
->blocked
);
621 INIT_LIST_HEAD(&res
->dirty
);
622 INIT_LIST_HEAD(&res
->recovering
);
623 INIT_LIST_HEAD(&res
->purge
);
624 INIT_LIST_HEAD(&res
->tracking
);
625 atomic_set(&res
->asts_reserved
, 0);
626 res
->migration_pending
= 0;
627 res
->inflight_locks
= 0;
629 /* put in dlm_lockres_release */
633 kref_init(&res
->refs
);
635 /* just for consistency */
636 spin_lock(&res
->spinlock
);
637 dlm_set_lockres_owner(dlm
, res
, DLM_LOCK_RES_OWNER_UNKNOWN
);
638 spin_unlock(&res
->spinlock
);
640 res
->state
= DLM_LOCK_RES_IN_PROGRESS
;
644 spin_lock(&dlm
->spinlock
);
645 list_add_tail(&res
->tracking
, &dlm
->tracking_list
);
646 spin_unlock(&dlm
->spinlock
);
648 memset(res
->lvb
, 0, DLM_LVB_LEN
);
649 memset(res
->refmap
, 0, sizeof(res
->refmap
));
652 struct dlm_lock_resource
*dlm_new_lockres(struct dlm_ctxt
*dlm
,
654 unsigned int namelen
)
656 struct dlm_lock_resource
*res
= NULL
;
658 res
= (struct dlm_lock_resource
*)
659 kmem_cache_zalloc(dlm_lockres_cache
, GFP_NOFS
);
663 res
->lockname
.name
= (char *)
664 kmem_cache_zalloc(dlm_lockname_cache
, GFP_NOFS
);
665 if (!res
->lockname
.name
)
668 dlm_init_lockres(dlm
, res
, name
, namelen
);
672 if (res
&& res
->lockname
.name
)
673 kmem_cache_free(dlm_lockname_cache
, (void *)res
->lockname
.name
);
676 kmem_cache_free(dlm_lockres_cache
, res
);
680 void __dlm_lockres_grab_inflight_ref(struct dlm_ctxt
*dlm
,
681 struct dlm_lock_resource
*res
,
687 assert_spin_locked(&res
->spinlock
);
689 if (!test_bit(dlm
->node_num
, res
->refmap
)) {
690 BUG_ON(res
->inflight_locks
!= 0);
691 dlm_lockres_set_refmap_bit(dlm
->node_num
, res
);
693 res
->inflight_locks
++;
694 mlog(0, "%s:%.*s: inflight++: now %u\n",
695 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
,
696 res
->inflight_locks
);
699 void __dlm_lockres_drop_inflight_ref(struct dlm_ctxt
*dlm
,
700 struct dlm_lock_resource
*res
,
704 assert_spin_locked(&res
->spinlock
);
706 BUG_ON(res
->inflight_locks
== 0);
707 res
->inflight_locks
--;
708 mlog(0, "%s:%.*s: inflight--: now %u\n",
709 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
,
710 res
->inflight_locks
);
711 if (res
->inflight_locks
== 0)
712 dlm_lockres_clear_refmap_bit(dlm
->node_num
, res
);
717 * lookup a lock resource by name.
718 * may already exist in the hashtable.
719 * lockid is null terminated
721 * if not, allocate enough for the lockres and for
722 * the temporary structure used in doing the mastering.
724 * also, do a lookup in the dlm->master_list to see
725 * if another node has begun mastering the same lock.
726 * if so, there should be a block entry in there
727 * for this name, and we should *not* attempt to master
728 * the lock here. need to wait around for that node
729 * to assert_master (or die).
732 struct dlm_lock_resource
* dlm_get_lock_resource(struct dlm_ctxt
*dlm
,
737 struct dlm_lock_resource
*tmpres
=NULL
, *res
=NULL
;
738 struct dlm_master_list_entry
*mle
= NULL
;
739 struct dlm_master_list_entry
*alloc_mle
= NULL
;
742 struct dlm_node_iter iter
;
745 int bit
, wait_on_recovery
= 0;
746 int drop_inflight_if_nonlocal
= 0;
750 hash
= dlm_lockid_hash(lockid
, namelen
);
752 mlog(0, "get lockres %s (len %d)\n", lockid
, namelen
);
755 spin_lock(&dlm
->spinlock
);
756 tmpres
= __dlm_lookup_lockres_full(dlm
, lockid
, namelen
, hash
);
758 int dropping_ref
= 0;
760 spin_unlock(&dlm
->spinlock
);
762 spin_lock(&tmpres
->spinlock
);
763 /* We wait for the other 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
);
769 if (tmpres
->owner
== dlm
->node_num
) {
770 BUG_ON(tmpres
->state
& DLM_LOCK_RES_DROPPING_REF
);
771 dlm_lockres_grab_inflight_ref(dlm
, tmpres
);
772 } else if (tmpres
->state
& DLM_LOCK_RES_DROPPING_REF
)
774 spin_unlock(&tmpres
->spinlock
);
776 /* wait until done messaging the master, drop our ref to allow
777 * the lockres to be purged, start over. */
779 spin_lock(&tmpres
->spinlock
);
780 __dlm_wait_on_lockres_flags(tmpres
, DLM_LOCK_RES_DROPPING_REF
);
781 spin_unlock(&tmpres
->spinlock
);
782 dlm_lockres_put(tmpres
);
787 mlog(0, "found in hash!\n");
789 dlm_lockres_put(res
);
795 spin_unlock(&dlm
->spinlock
);
796 mlog(0, "allocating a new resource\n");
797 /* nothing found and we need to allocate one. */
798 alloc_mle
= (struct dlm_master_list_entry
*)
799 kmem_cache_alloc(dlm_mle_cache
, GFP_NOFS
);
802 res
= dlm_new_lockres(dlm
, lockid
, namelen
);
808 mlog(0, "no lockres found, allocated our own: %p\n", res
);
810 if (flags
& LKM_LOCAL
) {
811 /* caller knows it's safe to assume it's not mastered elsewhere
812 * DONE! return right away */
813 spin_lock(&res
->spinlock
);
814 dlm_change_lockres_owner(dlm
, res
, dlm
->node_num
);
815 __dlm_insert_lockres(dlm
, res
);
816 dlm_lockres_grab_inflight_ref(dlm
, res
);
817 spin_unlock(&res
->spinlock
);
818 spin_unlock(&dlm
->spinlock
);
819 /* lockres still marked IN_PROGRESS */
823 /* check master list to see if another node has started mastering it */
824 spin_lock(&dlm
->master_lock
);
826 /* if we found a block, wait for lock to be mastered by another node */
827 blocked
= dlm_find_mle(dlm
, &mle
, (char *)lockid
, namelen
);
830 if (mle
->type
== DLM_MLE_MASTER
) {
831 mlog(ML_ERROR
, "master entry for nonexistent lock!\n");
834 mig
= (mle
->type
== DLM_MLE_MIGRATION
);
835 /* if there is a migration in progress, let the migration
836 * finish before continuing. we can wait for the absence
837 * of the MIGRATION mle: either the migrate finished or
838 * one of the nodes died and the mle was cleaned up.
839 * if there is a BLOCK here, but it already has a master
840 * set, we are too late. the master does not have a ref
841 * for us in the refmap. detach the mle and drop it.
842 * either way, go back to the top and start over. */
843 if (mig
|| mle
->master
!= O2NM_MAX_NODES
) {
844 BUG_ON(mig
&& mle
->master
== dlm
->node_num
);
845 /* we arrived too late. the master does not
846 * have a ref for us. retry. */
847 mlog(0, "%s:%.*s: late on %s\n",
848 dlm
->name
, namelen
, lockid
,
849 mig
? "MIGRATION" : "BLOCK");
850 spin_unlock(&dlm
->master_lock
);
851 spin_unlock(&dlm
->spinlock
);
853 /* master is known, detach */
855 dlm_mle_detach_hb_events(dlm
, mle
);
858 /* this is lame, but we cant wait on either
859 * the mle or lockres waitqueue here */
865 /* go ahead and try to master lock on this node */
867 /* make sure this does not get freed below */
869 dlm_init_mle(mle
, DLM_MLE_MASTER
, dlm
, res
, NULL
, 0);
870 set_bit(dlm
->node_num
, mle
->maybe_map
);
871 __dlm_insert_mle(dlm
, mle
);
873 /* still holding the dlm spinlock, check the recovery map
874 * to see if there are any nodes that still need to be
875 * considered. these will not appear in the mle nodemap
876 * but they might own this lockres. wait on them. */
877 bit
= find_next_bit(dlm
->recovery_map
, O2NM_MAX_NODES
, 0);
878 if (bit
< O2NM_MAX_NODES
) {
879 mlog(ML_NOTICE
, "%s:%.*s: at least one node (%d) to "
880 "recover before lock mastery can begin\n",
881 dlm
->name
, namelen
, (char *)lockid
, bit
);
882 wait_on_recovery
= 1;
886 /* at this point there is either a DLM_MLE_BLOCK or a
887 * DLM_MLE_MASTER on the master list, so it's safe to add the
888 * lockres to the hashtable. anyone who finds the lock will
889 * still have to wait on the IN_PROGRESS. */
891 /* finally add the lockres to its hash bucket */
892 __dlm_insert_lockres(dlm
, res
);
893 /* since this lockres is new it doesnt not require the spinlock */
894 dlm_lockres_grab_inflight_ref_new(dlm
, res
);
896 /* if this node does not become the master make sure to drop
897 * this inflight reference below */
898 drop_inflight_if_nonlocal
= 1;
900 /* get an extra ref on the mle in case this is a BLOCK
901 * if so, the creator of the BLOCK may try to put the last
902 * ref at this time in the assert master handler, so we
903 * need an extra one to keep from a bad ptr deref. */
904 dlm_get_mle_inuse(mle
);
905 spin_unlock(&dlm
->master_lock
);
906 spin_unlock(&dlm
->spinlock
);
909 while (wait_on_recovery
) {
910 /* any cluster changes that occurred after dropping the
911 * dlm spinlock would be detectable be a change on the mle,
912 * so we only need to clear out the recovery map once. */
913 if (dlm_is_recovery_lock(lockid
, namelen
)) {
914 mlog(ML_NOTICE
, "%s: recovery map is not empty, but "
915 "must master $RECOVERY lock now\n", dlm
->name
);
916 if (!dlm_pre_master_reco_lockres(dlm
, res
))
917 wait_on_recovery
= 0;
919 mlog(0, "%s: waiting 500ms for heartbeat state "
920 "change\n", dlm
->name
);
926 dlm_kick_recovery_thread(dlm
);
928 dlm_wait_for_recovery(dlm
);
930 spin_lock(&dlm
->spinlock
);
931 bit
= find_next_bit(dlm
->recovery_map
, O2NM_MAX_NODES
, 0);
932 if (bit
< O2NM_MAX_NODES
) {
933 mlog(ML_NOTICE
, "%s:%.*s: at least one node (%d) to "
934 "recover before lock mastery can begin\n",
935 dlm
->name
, namelen
, (char *)lockid
, bit
);
936 wait_on_recovery
= 1;
938 wait_on_recovery
= 0;
939 spin_unlock(&dlm
->spinlock
);
941 if (wait_on_recovery
)
942 dlm_wait_for_node_recovery(dlm
, bit
, 10000);
945 /* must wait for lock to be mastered elsewhere */
950 dlm_node_iter_init(mle
->vote_map
, &iter
);
951 while ((nodenum
= dlm_node_iter_next(&iter
)) >= 0) {
952 ret
= dlm_do_master_request(res
, mle
, nodenum
);
955 if (mle
->master
!= O2NM_MAX_NODES
) {
956 /* found a master ! */
957 if (mle
->master
<= nodenum
)
959 /* if our master request has not reached the master
960 * yet, keep going until it does. this is how the
961 * master will know that asserts are needed back to
962 * the lower nodes. */
963 mlog(0, "%s:%.*s: requests only up to %u but master "
964 "is %u, keep going\n", dlm
->name
, namelen
,
965 lockid
, nodenum
, mle
->master
);
970 /* keep going until the response map includes all nodes */
971 ret
= dlm_wait_for_lock_mastery(dlm
, res
, mle
, &blocked
);
973 wait_on_recovery
= 1;
974 mlog(0, "%s:%.*s: node map changed, redo the "
975 "master request now, blocked=%d\n",
976 dlm
->name
, res
->lockname
.len
,
977 res
->lockname
.name
, blocked
);
979 mlog(ML_ERROR
, "%s:%.*s: spinning on "
980 "dlm_wait_for_lock_mastery, blocked=%d\n",
981 dlm
->name
, res
->lockname
.len
,
982 res
->lockname
.name
, blocked
);
983 dlm_print_one_lock_resource(res
);
984 dlm_print_one_mle(mle
);
990 mlog(0, "lockres mastered by %u\n", res
->owner
);
991 /* make sure we never continue without this */
992 BUG_ON(res
->owner
== O2NM_MAX_NODES
);
994 /* master is known, detach if not already detached */
995 dlm_mle_detach_hb_events(dlm
, mle
);
997 /* put the extra ref */
998 dlm_put_mle_inuse(mle
);
1001 spin_lock(&res
->spinlock
);
1002 if (res
->owner
!= dlm
->node_num
&& drop_inflight_if_nonlocal
)
1003 dlm_lockres_drop_inflight_ref(dlm
, res
);
1004 res
->state
&= ~DLM_LOCK_RES_IN_PROGRESS
;
1005 spin_unlock(&res
->spinlock
);
1009 /* need to free the unused mle */
1011 kmem_cache_free(dlm_mle_cache
, alloc_mle
);
1017 #define DLM_MASTERY_TIMEOUT_MS 5000
1019 static int dlm_wait_for_lock_mastery(struct dlm_ctxt
*dlm
,
1020 struct dlm_lock_resource
*res
,
1021 struct dlm_master_list_entry
*mle
,
1026 int map_changed
, voting_done
;
1033 /* check if another node has already become the owner */
1034 spin_lock(&res
->spinlock
);
1035 if (res
->owner
!= DLM_LOCK_RES_OWNER_UNKNOWN
) {
1036 mlog(0, "%s:%.*s: owner is suddenly %u\n", dlm
->name
,
1037 res
->lockname
.len
, res
->lockname
.name
, res
->owner
);
1038 spin_unlock(&res
->spinlock
);
1039 /* this will cause the master to re-assert across
1040 * the whole cluster, freeing up mles */
1041 if (res
->owner
!= dlm
->node_num
) {
1042 ret
= dlm_do_master_request(res
, mle
, res
->owner
);
1044 /* give recovery a chance to run */
1045 mlog(ML_ERROR
, "link to %u went down?: %d\n", res
->owner
, ret
);
1053 spin_unlock(&res
->spinlock
);
1055 spin_lock(&mle
->spinlock
);
1057 map_changed
= (memcmp(mle
->vote_map
, mle
->node_map
,
1058 sizeof(mle
->vote_map
)) != 0);
1059 voting_done
= (memcmp(mle
->vote_map
, mle
->response_map
,
1060 sizeof(mle
->vote_map
)) == 0);
1062 /* restart if we hit any errors */
1065 mlog(0, "%s: %.*s: node map changed, restarting\n",
1066 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
);
1067 ret
= dlm_restart_lock_mastery(dlm
, res
, mle
, *blocked
);
1068 b
= (mle
->type
== DLM_MLE_BLOCK
);
1069 if ((*blocked
&& !b
) || (!*blocked
&& b
)) {
1070 mlog(0, "%s:%.*s: status change: old=%d new=%d\n",
1071 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
,
1075 spin_unlock(&mle
->spinlock
);
1080 mlog(0, "%s:%.*s: restart lock mastery succeeded, "
1081 "rechecking now\n", dlm
->name
, res
->lockname
.len
,
1082 res
->lockname
.name
);
1086 mlog(0, "map not changed and voting not done "
1087 "for %s:%.*s\n", dlm
->name
, res
->lockname
.len
,
1088 res
->lockname
.name
);
1092 if (m
!= O2NM_MAX_NODES
) {
1093 /* another node has done an assert!
1098 /* have all nodes responded? */
1099 if (voting_done
&& !*blocked
) {
1100 bit
= find_next_bit(mle
->maybe_map
, O2NM_MAX_NODES
, 0);
1101 if (dlm
->node_num
<= bit
) {
1102 /* my node number is lowest.
1103 * now tell other nodes that I am
1104 * mastering this. */
1105 mle
->master
= dlm
->node_num
;
1106 /* ref was grabbed in get_lock_resource
1107 * will be dropped in dlmlock_master */
1111 /* if voting is done, but we have not received
1112 * an assert master yet, we must sleep */
1116 spin_unlock(&mle
->spinlock
);
1118 /* sleep if we haven't finished voting yet */
1120 unsigned long timeo
= msecs_to_jiffies(DLM_MASTERY_TIMEOUT_MS
);
1123 if (atomic_read(&mle->mle_refs.refcount) < 2)
1124 mlog(ML_ERROR, "mle (%p) refs=%d, name=%.*s\n", mle,
1125 atomic_read(&mle->mle_refs.refcount),
1126 res->lockname.len, res->lockname.name);
1128 atomic_set(&mle
->woken
, 0);
1129 (void)wait_event_timeout(mle
->wq
,
1130 (atomic_read(&mle
->woken
) == 1),
1132 if (res
->owner
== O2NM_MAX_NODES
) {
1133 mlog(0, "%s:%.*s: waiting again\n", dlm
->name
,
1134 res
->lockname
.len
, res
->lockname
.name
);
1137 mlog(0, "done waiting, master is %u\n", res
->owner
);
1145 mlog(0, "about to master %.*s here, this=%u\n",
1146 res
->lockname
.len
, res
->lockname
.name
, m
);
1147 ret
= dlm_do_assert_master(dlm
, res
, mle
->vote_map
, 0);
1149 /* This is a failure in the network path,
1150 * not in the response to the assert_master
1151 * (any nonzero response is a BUG on this node).
1152 * Most likely a socket just got disconnected
1153 * due to node death. */
1156 /* no longer need to restart lock mastery.
1157 * all living nodes have been contacted. */
1161 /* set the lockres owner */
1162 spin_lock(&res
->spinlock
);
1163 /* mastery reference obtained either during
1164 * assert_master_handler or in get_lock_resource */
1165 dlm_change_lockres_owner(dlm
, res
, m
);
1166 spin_unlock(&res
->spinlock
);
1172 struct dlm_bitmap_diff_iter
1175 unsigned long *orig_bm
;
1176 unsigned long *cur_bm
;
1177 unsigned long diff_bm
[BITS_TO_LONGS(O2NM_MAX_NODES
)];
1180 enum dlm_node_state_change
1187 static void dlm_bitmap_diff_iter_init(struct dlm_bitmap_diff_iter
*iter
,
1188 unsigned long *orig_bm
,
1189 unsigned long *cur_bm
)
1191 unsigned long p1
, p2
;
1195 iter
->orig_bm
= orig_bm
;
1196 iter
->cur_bm
= cur_bm
;
1198 for (i
= 0; i
< BITS_TO_LONGS(O2NM_MAX_NODES
); i
++) {
1199 p1
= *(iter
->orig_bm
+ i
);
1200 p2
= *(iter
->cur_bm
+ i
);
1201 iter
->diff_bm
[i
] = (p1
& ~p2
) | (p2
& ~p1
);
1205 static int dlm_bitmap_diff_iter_next(struct dlm_bitmap_diff_iter
*iter
,
1206 enum dlm_node_state_change
*state
)
1210 if (iter
->curnode
>= O2NM_MAX_NODES
)
1213 bit
= find_next_bit(iter
->diff_bm
, O2NM_MAX_NODES
,
1215 if (bit
>= O2NM_MAX_NODES
) {
1216 iter
->curnode
= O2NM_MAX_NODES
;
1220 /* if it was there in the original then this node died */
1221 if (test_bit(bit
, iter
->orig_bm
))
1226 iter
->curnode
= bit
;
1231 static int dlm_restart_lock_mastery(struct dlm_ctxt
*dlm
,
1232 struct dlm_lock_resource
*res
,
1233 struct dlm_master_list_entry
*mle
,
1236 struct dlm_bitmap_diff_iter bdi
;
1237 enum dlm_node_state_change sc
;
1241 mlog(0, "something happened such that the "
1242 "master process may need to be restarted!\n");
1244 assert_spin_locked(&mle
->spinlock
);
1246 dlm_bitmap_diff_iter_init(&bdi
, mle
->vote_map
, mle
->node_map
);
1247 node
= dlm_bitmap_diff_iter_next(&bdi
, &sc
);
1249 if (sc
== NODE_UP
) {
1250 /* a node came up. clear any old vote from
1251 * the response map and set it in the vote map
1252 * then restart the mastery. */
1253 mlog(ML_NOTICE
, "node %d up while restarting\n", node
);
1255 /* redo the master request, but only for the new node */
1256 mlog(0, "sending request to new node\n");
1257 clear_bit(node
, mle
->response_map
);
1258 set_bit(node
, mle
->vote_map
);
1260 mlog(ML_ERROR
, "node down! %d\n", node
);
1262 int lowest
= find_next_bit(mle
->maybe_map
,
1265 /* act like it was never there */
1266 clear_bit(node
, mle
->maybe_map
);
1268 if (node
== lowest
) {
1269 mlog(0, "expected master %u died"
1270 " while this node was blocked "
1271 "waiting on it!\n", node
);
1272 lowest
= find_next_bit(mle
->maybe_map
,
1275 if (lowest
< O2NM_MAX_NODES
) {
1276 mlog(0, "%s:%.*s:still "
1277 "blocked. waiting on %u "
1283 /* mle is an MLE_BLOCK, but
1284 * there is now nothing left to
1285 * block on. we need to return
1286 * all the way back out and try
1287 * again with an MLE_MASTER.
1288 * dlm_do_local_recovery_cleanup
1289 * has already run, so the mle
1291 mlog(0, "%s:%.*s: no "
1292 "longer blocking. try to "
1293 "master this here\n",
1296 res
->lockname
.name
);
1297 mle
->type
= DLM_MLE_MASTER
;
1298 mle
->u
.mleres
= res
;
1303 /* now blank out everything, as if we had never
1304 * contacted anyone */
1305 memset(mle
->maybe_map
, 0, sizeof(mle
->maybe_map
));
1306 memset(mle
->response_map
, 0, sizeof(mle
->response_map
));
1307 /* reset the vote_map to the current node_map */
1308 memcpy(mle
->vote_map
, mle
->node_map
,
1309 sizeof(mle
->node_map
));
1310 /* put myself into the maybe map */
1311 if (mle
->type
!= DLM_MLE_BLOCK
)
1312 set_bit(dlm
->node_num
, mle
->maybe_map
);
1315 node
= dlm_bitmap_diff_iter_next(&bdi
, &sc
);
1322 * DLM_MASTER_REQUEST_MSG
1324 * returns: 0 on success,
1325 * -errno on a network error
1327 * on error, the caller should assume the target node is "dead"
1331 static int dlm_do_master_request(struct dlm_lock_resource
*res
,
1332 struct dlm_master_list_entry
*mle
, int to
)
1334 struct dlm_ctxt
*dlm
= mle
->dlm
;
1335 struct dlm_master_request request
;
1336 int ret
, response
=0, resend
;
1337 unsigned char *mlename
;
1338 unsigned int mlenamelen
;
1340 memset(&request
, 0, sizeof(request
));
1341 request
.node_idx
= dlm
->node_num
;
1343 BUG_ON(mle
->type
== DLM_MLE_MIGRATION
);
1345 __dlm_mle_name(mle
, &mlename
, &mlenamelen
);
1347 request
.namelen
= (u8
)mlenamelen
;
1348 memcpy(request
.name
, mlename
, 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;
1444 return DLM_MASTER_RESP_NO
;
1446 if (!dlm_domain_fully_joined(dlm
)) {
1447 response
= DLM_MASTER_RESP_NO
;
1451 name
= request
->name
;
1452 namelen
= request
->namelen
;
1453 hash
= dlm_lockid_hash(name
, namelen
);
1455 if (namelen
> DLM_LOCKID_NAME_MAX
) {
1456 response
= DLM_IVBUFLEN
;
1461 spin_lock(&dlm
->spinlock
);
1462 res
= __dlm_lookup_lockres(dlm
, name
, namelen
, hash
);
1464 spin_unlock(&dlm
->spinlock
);
1466 /* take care of the easy cases up front */
1467 spin_lock(&res
->spinlock
);
1468 if (res
->state
& (DLM_LOCK_RES_RECOVERING
|
1469 DLM_LOCK_RES_MIGRATING
)) {
1470 spin_unlock(&res
->spinlock
);
1471 mlog(0, "returning DLM_MASTER_RESP_ERROR since res is "
1472 "being recovered/migrated\n");
1473 response
= DLM_MASTER_RESP_ERROR
;
1475 kmem_cache_free(dlm_mle_cache
, mle
);
1479 if (res
->owner
== dlm
->node_num
) {
1480 mlog(0, "%s:%.*s: setting bit %u in refmap\n",
1481 dlm
->name
, namelen
, name
, request
->node_idx
);
1482 dlm_lockres_set_refmap_bit(request
->node_idx
, res
);
1483 spin_unlock(&res
->spinlock
);
1484 response
= DLM_MASTER_RESP_YES
;
1486 kmem_cache_free(dlm_mle_cache
, mle
);
1488 /* this node is the owner.
1489 * there is some extra work that needs to
1490 * happen now. the requesting node has
1491 * caused all nodes up to this one to
1492 * create mles. this node now needs to
1493 * go back and clean those up. */
1494 dispatch_assert
= 1;
1496 } else if (res
->owner
!= DLM_LOCK_RES_OWNER_UNKNOWN
) {
1497 spin_unlock(&res
->spinlock
);
1498 // mlog(0, "node %u is the master\n", res->owner);
1499 response
= DLM_MASTER_RESP_NO
;
1501 kmem_cache_free(dlm_mle_cache
, mle
);
1505 /* ok, there is no owner. either this node is
1506 * being blocked, or it is actively trying to
1507 * master this lock. */
1508 if (!(res
->state
& DLM_LOCK_RES_IN_PROGRESS
)) {
1509 mlog(ML_ERROR
, "lock with no owner should be "
1514 // mlog(0, "lockres is in progress...\n");
1515 spin_lock(&dlm
->master_lock
);
1516 found
= dlm_find_mle(dlm
, &tmpmle
, name
, namelen
);
1518 mlog(ML_ERROR
, "no mle found for this lock!\n");
1522 spin_lock(&tmpmle
->spinlock
);
1523 if (tmpmle
->type
== DLM_MLE_BLOCK
) {
1524 // mlog(0, "this node is waiting for "
1525 // "lockres to be mastered\n");
1526 response
= DLM_MASTER_RESP_NO
;
1527 } else if (tmpmle
->type
== DLM_MLE_MIGRATION
) {
1528 mlog(0, "node %u is master, but trying to migrate to "
1529 "node %u.\n", tmpmle
->master
, tmpmle
->new_master
);
1530 if (tmpmle
->master
== dlm
->node_num
) {
1531 mlog(ML_ERROR
, "no owner on lockres, but this "
1532 "node is trying to migrate it to %u?!\n",
1533 tmpmle
->new_master
);
1536 /* the real master can respond on its own */
1537 response
= DLM_MASTER_RESP_NO
;
1539 } else if (tmpmle
->master
!= DLM_LOCK_RES_OWNER_UNKNOWN
) {
1541 if (tmpmle
->master
== dlm
->node_num
) {
1542 response
= DLM_MASTER_RESP_YES
;
1543 /* this node will be the owner.
1544 * go back and clean the mles on any
1546 dispatch_assert
= 1;
1547 dlm_lockres_set_refmap_bit(request
->node_idx
, res
);
1548 mlog(0, "%s:%.*s: setting bit %u in refmap\n",
1549 dlm
->name
, namelen
, name
,
1552 response
= DLM_MASTER_RESP_NO
;
1554 // mlog(0, "this node is attempting to "
1555 // "master lockres\n");
1556 response
= DLM_MASTER_RESP_MAYBE
;
1559 set_bit(request
->node_idx
, tmpmle
->maybe_map
);
1560 spin_unlock(&tmpmle
->spinlock
);
1562 spin_unlock(&dlm
->master_lock
);
1563 spin_unlock(&res
->spinlock
);
1565 /* keep the mle attached to heartbeat events */
1566 dlm_put_mle(tmpmle
);
1568 kmem_cache_free(dlm_mle_cache
, mle
);
1573 * lockres doesn't exist on this node
1574 * if there is an MLE_BLOCK, return NO
1575 * if there is an MLE_MASTER, return MAYBE
1576 * otherwise, add an MLE_BLOCK, return NO
1578 spin_lock(&dlm
->master_lock
);
1579 found
= dlm_find_mle(dlm
, &tmpmle
, name
, namelen
);
1581 /* this lockid has never been seen on this node yet */
1582 // mlog(0, "no mle found\n");
1584 spin_unlock(&dlm
->master_lock
);
1585 spin_unlock(&dlm
->spinlock
);
1587 mle
= (struct dlm_master_list_entry
*)
1588 kmem_cache_alloc(dlm_mle_cache
, GFP_NOFS
);
1590 response
= DLM_MASTER_RESP_ERROR
;
1591 mlog_errno(-ENOMEM
);
1597 // mlog(0, "this is second time thru, already allocated, "
1598 // "add the block.\n");
1599 dlm_init_mle(mle
, DLM_MLE_BLOCK
, dlm
, NULL
, name
, namelen
);
1600 set_bit(request
->node_idx
, mle
->maybe_map
);
1601 __dlm_insert_mle(dlm
, mle
);
1602 response
= DLM_MASTER_RESP_NO
;
1604 // mlog(0, "mle was found\n");
1606 spin_lock(&tmpmle
->spinlock
);
1607 if (tmpmle
->master
== dlm
->node_num
) {
1608 mlog(ML_ERROR
, "no lockres, but an mle with this node as master!\n");
1611 if (tmpmle
->type
== DLM_MLE_BLOCK
)
1612 response
= DLM_MASTER_RESP_NO
;
1613 else if (tmpmle
->type
== DLM_MLE_MIGRATION
) {
1614 mlog(0, "migration mle was found (%u->%u)\n",
1615 tmpmle
->master
, tmpmle
->new_master
);
1616 /* real master can respond on its own */
1617 response
= DLM_MASTER_RESP_NO
;
1619 response
= DLM_MASTER_RESP_MAYBE
;
1621 set_bit(request
->node_idx
, tmpmle
->maybe_map
);
1622 spin_unlock(&tmpmle
->spinlock
);
1624 spin_unlock(&dlm
->master_lock
);
1625 spin_unlock(&dlm
->spinlock
);
1628 /* keep the mle attached to heartbeat events */
1629 dlm_put_mle(tmpmle
);
1633 * __dlm_lookup_lockres() grabbed a reference to this lockres.
1634 * The reference is released by dlm_assert_master_worker() under
1635 * the call to dlm_dispatch_assert_master(). If
1636 * dlm_assert_master_worker() isn't called, we drop it here.
1638 if (dispatch_assert
) {
1639 if (response
!= DLM_MASTER_RESP_YES
)
1640 mlog(ML_ERROR
, "invalid response %d\n", response
);
1642 mlog(ML_ERROR
, "bad lockres while trying to assert!\n");
1645 mlog(0, "%u is the owner of %.*s, cleaning everyone else\n",
1646 dlm
->node_num
, res
->lockname
.len
, res
->lockname
.name
);
1647 ret
= dlm_dispatch_assert_master(dlm
, res
, 0, request
->node_idx
,
1648 DLM_ASSERT_MASTER_MLE_CLEANUP
);
1650 mlog(ML_ERROR
, "failed to dispatch assert master work\n");
1651 response
= DLM_MASTER_RESP_ERROR
;
1652 dlm_lockres_put(res
);
1656 dlm_lockres_put(res
);
1664 * DLM_ASSERT_MASTER_MSG
1669 * NOTE: this can be used for debugging
1670 * can periodically run all locks owned by this node
1671 * and re-assert across the cluster...
1673 static int dlm_do_assert_master(struct dlm_ctxt
*dlm
,
1674 struct dlm_lock_resource
*res
,
1675 void *nodemap
, u32 flags
)
1677 struct dlm_assert_master
assert;
1679 struct dlm_node_iter iter
;
1682 const char *lockname
= res
->lockname
.name
;
1683 unsigned int namelen
= res
->lockname
.len
;
1685 BUG_ON(namelen
> O2NM_MAX_NAME_LEN
);
1687 spin_lock(&res
->spinlock
);
1688 res
->state
|= DLM_LOCK_RES_SETREF_INPROG
;
1689 spin_unlock(&res
->spinlock
);
1694 /* note that if this nodemap is empty, it returns 0 */
1695 dlm_node_iter_init(nodemap
, &iter
);
1696 while ((to
= dlm_node_iter_next(&iter
)) >= 0) {
1698 struct dlm_master_list_entry
*mle
= NULL
;
1700 mlog(0, "sending assert master to %d (%.*s)\n", to
,
1702 memset(&assert, 0, sizeof(assert));
1703 assert.node_idx
= dlm
->node_num
;
1704 assert.namelen
= namelen
;
1705 memcpy(assert.name
, lockname
, namelen
);
1706 assert.flags
= cpu_to_be32(flags
);
1708 tmpret
= o2net_send_message(DLM_ASSERT_MASTER_MSG
, dlm
->key
,
1709 &assert, sizeof(assert), to
, &r
);
1711 mlog(0, "assert_master returned %d!\n", tmpret
);
1712 if (!dlm_is_host_down(tmpret
)) {
1713 mlog(ML_ERROR
, "unhandled error=%d!\n", tmpret
);
1716 /* a node died. finish out the rest of the nodes. */
1717 mlog(0, "link to %d went down!\n", to
);
1718 /* any nonzero status return will do */
1722 /* ok, something horribly messed. kill thyself. */
1723 mlog(ML_ERROR
,"during assert master of %.*s to %u, "
1724 "got %d.\n", namelen
, lockname
, to
, r
);
1725 spin_lock(&dlm
->spinlock
);
1726 spin_lock(&dlm
->master_lock
);
1727 if (dlm_find_mle(dlm
, &mle
, (char *)lockname
,
1729 dlm_print_one_mle(mle
);
1732 spin_unlock(&dlm
->master_lock
);
1733 spin_unlock(&dlm
->spinlock
);
1737 if (r
& DLM_ASSERT_RESPONSE_REASSERT
&&
1738 !(r
& DLM_ASSERT_RESPONSE_MASTERY_REF
)) {
1739 mlog(ML_ERROR
, "%.*s: very strange, "
1740 "master MLE but no lockres on %u\n",
1741 namelen
, lockname
, to
);
1744 if (r
& DLM_ASSERT_RESPONSE_REASSERT
) {
1745 mlog(0, "%.*s: node %u create mles on other "
1746 "nodes and requests a re-assert\n",
1747 namelen
, lockname
, to
);
1750 if (r
& DLM_ASSERT_RESPONSE_MASTERY_REF
) {
1751 mlog(0, "%.*s: node %u has a reference to this "
1752 "lockres, set the bit in the refmap\n",
1753 namelen
, lockname
, to
);
1754 spin_lock(&res
->spinlock
);
1755 dlm_lockres_set_refmap_bit(to
, res
);
1756 spin_unlock(&res
->spinlock
);
1763 spin_lock(&res
->spinlock
);
1764 res
->state
&= ~DLM_LOCK_RES_SETREF_INPROG
;
1765 spin_unlock(&res
->spinlock
);
1772 * locks that can be taken here:
1778 * if possible, TRIM THIS DOWN!!!
1780 int dlm_assert_master_handler(struct o2net_msg
*msg
, u32 len
, void *data
,
1783 struct dlm_ctxt
*dlm
= data
;
1784 struct dlm_master_list_entry
*mle
= NULL
;
1785 struct dlm_assert_master
*assert = (struct dlm_assert_master
*)msg
->buf
;
1786 struct dlm_lock_resource
*res
= NULL
;
1788 unsigned int namelen
, hash
;
1790 int master_request
= 0, have_lockres_ref
= 0;
1796 name
= assert->name
;
1797 namelen
= assert->namelen
;
1798 hash
= dlm_lockid_hash(name
, namelen
);
1799 flags
= be32_to_cpu(assert->flags
);
1801 if (namelen
> DLM_LOCKID_NAME_MAX
) {
1802 mlog(ML_ERROR
, "Invalid name length!");
1806 spin_lock(&dlm
->spinlock
);
1809 mlog(0, "assert_master with flags: %u\n", flags
);
1812 spin_lock(&dlm
->master_lock
);
1813 if (!dlm_find_mle(dlm
, &mle
, name
, namelen
)) {
1814 /* not an error, could be master just re-asserting */
1815 mlog(0, "just got an assert_master from %u, but no "
1816 "MLE for it! (%.*s)\n", assert->node_idx
,
1819 int bit
= find_next_bit (mle
->maybe_map
, O2NM_MAX_NODES
, 0);
1820 if (bit
>= O2NM_MAX_NODES
) {
1821 /* not necessarily an error, though less likely.
1822 * could be master just re-asserting. */
1823 mlog(0, "no bits set in the maybe_map, but %u "
1824 "is asserting! (%.*s)\n", assert->node_idx
,
1826 } else if (bit
!= assert->node_idx
) {
1827 if (flags
& DLM_ASSERT_MASTER_MLE_CLEANUP
) {
1828 mlog(0, "master %u was found, %u should "
1829 "back off\n", assert->node_idx
, bit
);
1831 /* with the fix for bug 569, a higher node
1832 * number winning the mastery will respond
1833 * YES to mastery requests, but this node
1834 * had no way of knowing. let it pass. */
1835 mlog(0, "%u is the lowest node, "
1836 "%u is asserting. (%.*s) %u must "
1837 "have begun after %u won.\n", bit
,
1838 assert->node_idx
, namelen
, name
, bit
,
1842 if (mle
->type
== DLM_MLE_MIGRATION
) {
1843 if (flags
& DLM_ASSERT_MASTER_MLE_CLEANUP
) {
1844 mlog(0, "%s:%.*s: got cleanup assert"
1845 " from %u for migration\n",
1846 dlm
->name
, namelen
, name
,
1848 } else if (!(flags
& DLM_ASSERT_MASTER_FINISH_MIGRATION
)) {
1849 mlog(0, "%s:%.*s: got unrelated assert"
1850 " from %u for migration, ignoring\n",
1851 dlm
->name
, namelen
, name
,
1854 spin_unlock(&dlm
->master_lock
);
1855 spin_unlock(&dlm
->spinlock
);
1860 spin_unlock(&dlm
->master_lock
);
1862 /* ok everything checks out with the MLE
1863 * now check to see if there is a lockres */
1864 res
= __dlm_lookup_lockres(dlm
, name
, namelen
, hash
);
1866 spin_lock(&res
->spinlock
);
1867 if (res
->state
& DLM_LOCK_RES_RECOVERING
) {
1868 mlog(ML_ERROR
, "%u asserting but %.*s is "
1869 "RECOVERING!\n", assert->node_idx
, namelen
, name
);
1873 if (res
->owner
!= DLM_LOCK_RES_OWNER_UNKNOWN
&&
1874 res
->owner
!= assert->node_idx
) {
1875 mlog(ML_ERROR
, "DIE! Mastery assert from %u, "
1876 "but current owner is %u! (%.*s)\n",
1877 assert->node_idx
, res
->owner
, namelen
,
1879 __dlm_print_one_lock_resource(res
);
1882 } else if (mle
->type
!= DLM_MLE_MIGRATION
) {
1883 if (res
->owner
!= DLM_LOCK_RES_OWNER_UNKNOWN
) {
1884 /* owner is just re-asserting */
1885 if (res
->owner
== assert->node_idx
) {
1886 mlog(0, "owner %u re-asserting on "
1887 "lock %.*s\n", assert->node_idx
,
1891 mlog(ML_ERROR
, "got assert_master from "
1892 "node %u, but %u is the owner! "
1893 "(%.*s)\n", assert->node_idx
,
1894 res
->owner
, namelen
, name
);
1897 if (!(res
->state
& DLM_LOCK_RES_IN_PROGRESS
)) {
1898 mlog(ML_ERROR
, "got assert from %u, but lock "
1899 "with no owner should be "
1900 "in-progress! (%.*s)\n",
1905 } else /* mle->type == DLM_MLE_MIGRATION */ {
1906 /* should only be getting an assert from new master */
1907 if (assert->node_idx
!= mle
->new_master
) {
1908 mlog(ML_ERROR
, "got assert from %u, but "
1909 "new master is %u, and old master "
1911 assert->node_idx
, mle
->new_master
,
1912 mle
->master
, namelen
, name
);
1918 spin_unlock(&res
->spinlock
);
1920 spin_unlock(&dlm
->spinlock
);
1922 // mlog(0, "woo! got an assert_master from node %u!\n",
1923 // assert->node_idx);
1929 spin_lock(&mle
->spinlock
);
1930 if (mle
->type
== DLM_MLE_BLOCK
|| mle
->type
== DLM_MLE_MIGRATION
)
1933 /* MASTER mle: if any bits set in the response map
1934 * then the calling node needs to re-assert to clear
1935 * up nodes that this node contacted */
1936 while ((nn
= find_next_bit (mle
->response_map
, O2NM_MAX_NODES
,
1937 nn
+1)) < O2NM_MAX_NODES
) {
1938 if (nn
!= dlm
->node_num
&& nn
!= assert->node_idx
)
1942 mle
->master
= assert->node_idx
;
1943 atomic_set(&mle
->woken
, 1);
1945 spin_unlock(&mle
->spinlock
);
1949 spin_lock(&res
->spinlock
);
1950 if (mle
->type
== DLM_MLE_MIGRATION
) {
1951 mlog(0, "finishing off migration of lockres %.*s, "
1953 res
->lockname
.len
, res
->lockname
.name
,
1954 dlm
->node_num
, mle
->new_master
);
1955 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
1957 dlm_change_lockres_owner(dlm
, res
, mle
->new_master
);
1958 BUG_ON(res
->state
& DLM_LOCK_RES_DIRTY
);
1960 dlm_change_lockres_owner(dlm
, res
, mle
->master
);
1962 spin_unlock(&res
->spinlock
);
1963 have_lockres_ref
= 1;
1968 /* master is known, detach if not already detached.
1969 * ensures that only one assert_master call will happen
1971 spin_lock(&dlm
->spinlock
);
1972 spin_lock(&dlm
->master_lock
);
1974 rr
= atomic_read(&mle
->mle_refs
.refcount
);
1975 if (mle
->inuse
> 0) {
1976 if (extra_ref
&& rr
< 3)
1978 else if (!extra_ref
&& rr
< 2)
1981 if (extra_ref
&& rr
< 2)
1983 else if (!extra_ref
&& rr
< 1)
1987 mlog(ML_ERROR
, "%s:%.*s: got assert master from %u "
1988 "that will mess up this node, refs=%d, extra=%d, "
1989 "inuse=%d\n", dlm
->name
, namelen
, name
,
1990 assert->node_idx
, rr
, extra_ref
, mle
->inuse
);
1991 dlm_print_one_mle(mle
);
1993 __dlm_unlink_mle(dlm
, mle
);
1994 __dlm_mle_detach_hb_events(dlm
, mle
);
1997 /* the assert master message now balances the extra
1998 * ref given by the master / migration request message.
1999 * if this is the last put, it will be removed
2003 spin_unlock(&dlm
->master_lock
);
2004 spin_unlock(&dlm
->spinlock
);
2006 if (res
->owner
!= assert->node_idx
) {
2007 mlog(0, "assert_master from %u, but current "
2008 "owner is %u (%.*s), no mle\n", assert->node_idx
,
2009 res
->owner
, namelen
, name
);
2016 spin_lock(&res
->spinlock
);
2017 res
->state
|= DLM_LOCK_RES_SETREF_INPROG
;
2018 spin_unlock(&res
->spinlock
);
2019 *ret_data
= (void *)res
;
2022 if (master_request
) {
2023 mlog(0, "need to tell master to reassert\n");
2024 /* positive. negative would shoot down the node. */
2025 ret
|= DLM_ASSERT_RESPONSE_REASSERT
;
2026 if (!have_lockres_ref
) {
2027 mlog(ML_ERROR
, "strange, got assert from %u, MASTER "
2028 "mle present here for %s:%.*s, but no lockres!\n",
2029 assert->node_idx
, dlm
->name
, namelen
, name
);
2032 if (have_lockres_ref
) {
2033 /* let the master know we have a reference to the lockres */
2034 ret
|= DLM_ASSERT_RESPONSE_MASTERY_REF
;
2035 mlog(0, "%s:%.*s: got assert from %u, need a ref\n",
2036 dlm
->name
, namelen
, name
, assert->node_idx
);
2041 /* kill the caller! */
2042 mlog(ML_ERROR
, "Bad message received from another node. Dumping state "
2043 "and killing the other node now! This node is OK and can continue.\n");
2044 __dlm_print_one_lock_resource(res
);
2045 spin_unlock(&res
->spinlock
);
2046 spin_unlock(&dlm
->spinlock
);
2047 *ret_data
= (void *)res
;
2052 void dlm_assert_master_post_handler(int status
, void *data
, void *ret_data
)
2054 struct dlm_lock_resource
*res
= (struct dlm_lock_resource
*)ret_data
;
2057 spin_lock(&res
->spinlock
);
2058 res
->state
&= ~DLM_LOCK_RES_SETREF_INPROG
;
2059 spin_unlock(&res
->spinlock
);
2061 dlm_lockres_put(res
);
2066 int dlm_dispatch_assert_master(struct dlm_ctxt
*dlm
,
2067 struct dlm_lock_resource
*res
,
2068 int ignore_higher
, u8 request_from
, u32 flags
)
2070 struct dlm_work_item
*item
;
2071 item
= kzalloc(sizeof(*item
), GFP_NOFS
);
2076 /* queue up work for dlm_assert_master_worker */
2077 dlm_grab(dlm
); /* get an extra ref for the work item */
2078 dlm_init_work_item(dlm
, item
, dlm_assert_master_worker
, NULL
);
2079 item
->u
.am
.lockres
= res
; /* already have a ref */
2080 /* can optionally ignore node numbers higher than this node */
2081 item
->u
.am
.ignore_higher
= ignore_higher
;
2082 item
->u
.am
.request_from
= request_from
;
2083 item
->u
.am
.flags
= flags
;
2086 mlog(0, "IGNORE HIGHER: %.*s\n", res
->lockname
.len
,
2087 res
->lockname
.name
);
2089 spin_lock(&dlm
->work_lock
);
2090 list_add_tail(&item
->list
, &dlm
->work_list
);
2091 spin_unlock(&dlm
->work_lock
);
2093 queue_work(dlm
->dlm_worker
, &dlm
->dispatched_work
);
2097 static void dlm_assert_master_worker(struct dlm_work_item
*item
, void *data
)
2099 struct dlm_ctxt
*dlm
= data
;
2101 struct dlm_lock_resource
*res
;
2102 unsigned long nodemap
[BITS_TO_LONGS(O2NM_MAX_NODES
)];
2109 res
= item
->u
.am
.lockres
;
2110 ignore_higher
= item
->u
.am
.ignore_higher
;
2111 request_from
= item
->u
.am
.request_from
;
2112 flags
= item
->u
.am
.flags
;
2114 spin_lock(&dlm
->spinlock
);
2115 memcpy(nodemap
, dlm
->domain_map
, sizeof(nodemap
));
2116 spin_unlock(&dlm
->spinlock
);
2118 clear_bit(dlm
->node_num
, nodemap
);
2119 if (ignore_higher
) {
2120 /* if is this just to clear up mles for nodes below
2121 * this node, do not send the message to the original
2122 * caller or any node number higher than this */
2123 clear_bit(request_from
, nodemap
);
2124 bit
= dlm
->node_num
;
2126 bit
= find_next_bit(nodemap
, O2NM_MAX_NODES
,
2128 if (bit
>= O2NM_MAX_NODES
)
2130 clear_bit(bit
, nodemap
);
2135 * If we're migrating this lock to someone else, we are no
2136 * longer allowed to assert out own mastery. OTOH, we need to
2137 * prevent migration from starting while we're still asserting
2138 * our dominance. The reserved ast delays migration.
2140 spin_lock(&res
->spinlock
);
2141 if (res
->state
& DLM_LOCK_RES_MIGRATING
) {
2142 mlog(0, "Someone asked us to assert mastery, but we're "
2143 "in the middle of migration. Skipping assert, "
2144 "the new master will handle that.\n");
2145 spin_unlock(&res
->spinlock
);
2148 __dlm_lockres_reserve_ast(res
);
2149 spin_unlock(&res
->spinlock
);
2151 /* this call now finishes out the nodemap
2152 * even if one or more nodes die */
2153 mlog(0, "worker about to master %.*s here, this=%u\n",
2154 res
->lockname
.len
, res
->lockname
.name
, dlm
->node_num
);
2155 ret
= dlm_do_assert_master(dlm
, res
, nodemap
, flags
);
2157 /* no need to restart, we are done */
2158 if (!dlm_is_host_down(ret
))
2162 /* Ok, we've asserted ourselves. Let's let migration start. */
2163 dlm_lockres_release_ast(dlm
, res
);
2166 dlm_lockres_put(res
);
2168 mlog(0, "finished with dlm_assert_master_worker\n");
2171 /* SPECIAL CASE for the $RECOVERY lock used by the recovery thread.
2172 * We cannot wait for node recovery to complete to begin mastering this
2173 * lockres because this lockres is used to kick off recovery! ;-)
2174 * So, do a pre-check on all living nodes to see if any of those nodes
2175 * think that $RECOVERY is currently mastered by a dead node. If so,
2176 * we wait a short time to allow that node to get notified by its own
2177 * heartbeat stack, then check again. All $RECOVERY lock resources
2178 * mastered by dead nodes are purged when the hearbeat callback is
2179 * fired, so we can know for sure that it is safe to continue once
2180 * the node returns a live node or no node. */
2181 static int dlm_pre_master_reco_lockres(struct dlm_ctxt
*dlm
,
2182 struct dlm_lock_resource
*res
)
2184 struct dlm_node_iter iter
;
2187 u8 master
= DLM_LOCK_RES_OWNER_UNKNOWN
;
2189 spin_lock(&dlm
->spinlock
);
2190 dlm_node_iter_init(dlm
->domain_map
, &iter
);
2191 spin_unlock(&dlm
->spinlock
);
2193 while ((nodenum
= dlm_node_iter_next(&iter
)) >= 0) {
2194 /* do not send to self */
2195 if (nodenum
== dlm
->node_num
)
2197 ret
= dlm_do_master_requery(dlm
, res
, nodenum
, &master
);
2200 if (!dlm_is_host_down(ret
))
2202 /* host is down, so answer for that node would be
2203 * DLM_LOCK_RES_OWNER_UNKNOWN. continue. */
2207 if (master
!= DLM_LOCK_RES_OWNER_UNKNOWN
) {
2208 /* check to see if this master is in the recovery map */
2209 spin_lock(&dlm
->spinlock
);
2210 if (test_bit(master
, dlm
->recovery_map
)) {
2211 mlog(ML_NOTICE
, "%s: node %u has not seen "
2212 "node %u go down yet, and thinks the "
2213 "dead node is mastering the recovery "
2214 "lock. must wait.\n", dlm
->name
,
2218 spin_unlock(&dlm
->spinlock
);
2219 mlog(0, "%s: reco lock master is %u\n", dlm
->name
,
2228 * DLM_DEREF_LOCKRES_MSG
2231 int dlm_drop_lockres_ref(struct dlm_ctxt
*dlm
, struct dlm_lock_resource
*res
)
2233 struct dlm_deref_lockres deref
;
2235 const char *lockname
;
2236 unsigned int namelen
;
2238 lockname
= res
->lockname
.name
;
2239 namelen
= res
->lockname
.len
;
2240 BUG_ON(namelen
> O2NM_MAX_NAME_LEN
);
2242 mlog(0, "%s:%.*s: sending deref to %d\n",
2243 dlm
->name
, namelen
, lockname
, res
->owner
);
2244 memset(&deref
, 0, sizeof(deref
));
2245 deref
.node_idx
= dlm
->node_num
;
2246 deref
.namelen
= namelen
;
2247 memcpy(deref
.name
, lockname
, namelen
);
2249 ret
= o2net_send_message(DLM_DEREF_LOCKRES_MSG
, dlm
->key
,
2250 &deref
, sizeof(deref
), res
->owner
, &r
);
2254 /* BAD. other node says I did not have a ref. */
2255 mlog(ML_ERROR
,"while dropping ref on %s:%.*s "
2256 "(master=%u) got %d.\n", dlm
->name
, namelen
,
2257 lockname
, res
->owner
, r
);
2258 dlm_print_one_lock_resource(res
);
2264 int dlm_deref_lockres_handler(struct o2net_msg
*msg
, u32 len
, void *data
,
2267 struct dlm_ctxt
*dlm
= data
;
2268 struct dlm_deref_lockres
*deref
= (struct dlm_deref_lockres
*)msg
->buf
;
2269 struct dlm_lock_resource
*res
= NULL
;
2271 unsigned int namelen
;
2275 struct dlm_work_item
*item
;
2283 namelen
= deref
->namelen
;
2284 node
= deref
->node_idx
;
2286 if (namelen
> DLM_LOCKID_NAME_MAX
) {
2287 mlog(ML_ERROR
, "Invalid name length!");
2290 if (deref
->node_idx
>= O2NM_MAX_NODES
) {
2291 mlog(ML_ERROR
, "Invalid node number: %u\n", node
);
2295 hash
= dlm_lockid_hash(name
, namelen
);
2297 spin_lock(&dlm
->spinlock
);
2298 res
= __dlm_lookup_lockres_full(dlm
, name
, namelen
, hash
);
2300 spin_unlock(&dlm
->spinlock
);
2301 mlog(ML_ERROR
, "%s:%.*s: bad lockres name\n",
2302 dlm
->name
, namelen
, name
);
2305 spin_unlock(&dlm
->spinlock
);
2307 spin_lock(&res
->spinlock
);
2308 if (res
->state
& DLM_LOCK_RES_SETREF_INPROG
)
2311 BUG_ON(res
->state
& DLM_LOCK_RES_DROPPING_REF
);
2312 if (test_bit(node
, res
->refmap
)) {
2313 dlm_lockres_clear_refmap_bit(node
, res
);
2317 spin_unlock(&res
->spinlock
);
2321 dlm_lockres_calc_usage(dlm
, res
);
2323 mlog(ML_ERROR
, "%s:%.*s: node %u trying to drop ref "
2324 "but it is already dropped!\n", dlm
->name
,
2325 res
->lockname
.len
, res
->lockname
.name
, node
);
2326 dlm_print_one_lock_resource(res
);
2332 item
= kzalloc(sizeof(*item
), GFP_NOFS
);
2339 dlm_init_work_item(dlm
, item
, dlm_deref_lockres_worker
, NULL
);
2340 item
->u
.dl
.deref_res
= res
;
2341 item
->u
.dl
.deref_node
= node
;
2343 spin_lock(&dlm
->work_lock
);
2344 list_add_tail(&item
->list
, &dlm
->work_list
);
2345 spin_unlock(&dlm
->work_lock
);
2347 queue_work(dlm
->dlm_worker
, &dlm
->dispatched_work
);
2352 dlm_lockres_put(res
);
2358 static void dlm_deref_lockres_worker(struct dlm_work_item
*item
, void *data
)
2360 struct dlm_ctxt
*dlm
;
2361 struct dlm_lock_resource
*res
;
2366 res
= item
->u
.dl
.deref_res
;
2367 node
= item
->u
.dl
.deref_node
;
2369 spin_lock(&res
->spinlock
);
2370 BUG_ON(res
->state
& DLM_LOCK_RES_DROPPING_REF
);
2371 if (test_bit(node
, res
->refmap
)) {
2372 __dlm_wait_on_lockres_flags(res
, DLM_LOCK_RES_SETREF_INPROG
);
2373 dlm_lockres_clear_refmap_bit(node
, res
);
2376 spin_unlock(&res
->spinlock
);
2379 mlog(0, "%s:%.*s node %u ref dropped in dispatch\n",
2380 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
, node
);
2381 dlm_lockres_calc_usage(dlm
, res
);
2383 mlog(ML_ERROR
, "%s:%.*s: node %u trying to drop ref "
2384 "but it is already dropped!\n", dlm
->name
,
2385 res
->lockname
.len
, res
->lockname
.name
, node
);
2386 dlm_print_one_lock_resource(res
);
2389 dlm_lockres_put(res
);
2392 /* Checks whether the lockres can be migrated. Returns 0 if yes, < 0
2393 * if not. If 0, numlocks is set to the number of locks in the lockres.
2395 static int dlm_is_lockres_migrateable(struct dlm_ctxt
*dlm
,
2396 struct dlm_lock_resource
*res
,
2402 struct list_head
*queue
;
2403 struct dlm_lock
*lock
;
2405 assert_spin_locked(&res
->spinlock
);
2408 if (res
->owner
== DLM_LOCK_RES_OWNER_UNKNOWN
) {
2409 mlog(0, "cannot migrate lockres with unknown owner!\n");
2413 if (res
->owner
!= dlm
->node_num
) {
2414 mlog(0, "cannot migrate lockres this node doesn't own!\n");
2419 queue
= &res
->granted
;
2420 for (i
= 0; i
< 3; i
++) {
2421 list_for_each_entry(lock
, queue
, list
) {
2423 if (lock
->ml
.node
== dlm
->node_num
) {
2424 mlog(0, "found a lock owned by this node still "
2425 "on the %s queue! will not migrate this "
2426 "lockres\n", (i
== 0 ? "granted" :
2427 (i
== 1 ? "converting" :
2437 mlog(0, "migrateable lockres having %d locks\n", *numlocks
);
2444 * DLM_MIGRATE_LOCKRES
2448 static int dlm_migrate_lockres(struct dlm_ctxt
*dlm
,
2449 struct dlm_lock_resource
*res
,
2452 struct dlm_master_list_entry
*mle
= NULL
;
2453 struct dlm_master_list_entry
*oldmle
= NULL
;
2454 struct dlm_migratable_lockres
*mres
= NULL
;
2457 unsigned int namelen
;
2465 name
= res
->lockname
.name
;
2466 namelen
= res
->lockname
.len
;
2468 mlog(0, "migrating %.*s to %u\n", namelen
, name
, target
);
2471 * ensure this lockres is a proper candidate for migration
2473 spin_lock(&res
->spinlock
);
2474 ret
= dlm_is_lockres_migrateable(dlm
, res
, &numlocks
);
2476 spin_unlock(&res
->spinlock
);
2479 spin_unlock(&res
->spinlock
);
2482 if (numlocks
== 0) {
2483 mlog(0, "no locks were found on this lockres! done!\n");
2488 * preallocate up front
2489 * if this fails, abort
2493 mres
= (struct dlm_migratable_lockres
*) __get_free_page(GFP_NOFS
);
2499 mle
= (struct dlm_master_list_entry
*) kmem_cache_alloc(dlm_mle_cache
,
2508 * find a node to migrate the lockres to
2511 mlog(0, "picking a migration node\n");
2512 spin_lock(&dlm
->spinlock
);
2513 /* pick a new node */
2514 if (!test_bit(target
, dlm
->domain_map
) ||
2515 target
>= O2NM_MAX_NODES
) {
2516 target
= dlm_pick_migration_target(dlm
, res
);
2518 mlog(0, "node %u chosen for migration\n", target
);
2520 if (target
>= O2NM_MAX_NODES
||
2521 !test_bit(target
, dlm
->domain_map
)) {
2522 /* target chosen is not alive */
2527 spin_unlock(&dlm
->spinlock
);
2531 mlog(0, "continuing with target = %u\n", target
);
2534 * clear any existing master requests and
2535 * add the migration mle to the list
2537 spin_lock(&dlm
->master_lock
);
2538 ret
= dlm_add_migration_mle(dlm
, res
, mle
, &oldmle
, name
,
2539 namelen
, target
, dlm
->node_num
);
2540 spin_unlock(&dlm
->master_lock
);
2541 spin_unlock(&dlm
->spinlock
);
2543 if (ret
== -EEXIST
) {
2544 mlog(0, "another process is already migrating it\n");
2550 * set the MIGRATING flag and flush asts
2551 * if we fail after this we need to re-dirty the lockres
2553 if (dlm_mark_lockres_migrating(dlm
, res
, target
) < 0) {
2554 mlog(ML_ERROR
, "tried to migrate %.*s to %u, but "
2555 "the target went down.\n", res
->lockname
.len
,
2556 res
->lockname
.name
, target
);
2557 spin_lock(&res
->spinlock
);
2558 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
2560 spin_unlock(&res
->spinlock
);
2566 /* master is known, detach if not already detached */
2567 dlm_mle_detach_hb_events(dlm
, oldmle
);
2568 dlm_put_mle(oldmle
);
2573 dlm_mle_detach_hb_events(dlm
, mle
);
2576 kmem_cache_free(dlm_mle_cache
, mle
);
2582 * at this point, we have a migration target, an mle
2583 * in the master list, and the MIGRATING flag set on
2587 /* now that remote nodes are spinning on the MIGRATING flag,
2588 * ensure that all assert_master work is flushed. */
2589 flush_workqueue(dlm
->dlm_worker
);
2591 /* get an extra reference on the mle.
2592 * otherwise the assert_master from the new
2593 * master will destroy this.
2594 * also, make sure that all callers of dlm_get_mle
2595 * take both dlm->spinlock and dlm->master_lock */
2596 spin_lock(&dlm
->spinlock
);
2597 spin_lock(&dlm
->master_lock
);
2598 dlm_get_mle_inuse(mle
);
2599 spin_unlock(&dlm
->master_lock
);
2600 spin_unlock(&dlm
->spinlock
);
2602 /* notify new node and send all lock state */
2603 /* call send_one_lockres with migration flag.
2604 * this serves as notice to the target node that a
2605 * migration is starting. */
2606 ret
= dlm_send_one_lockres(dlm
, res
, mres
, target
,
2607 DLM_MRES_MIGRATION
);
2610 mlog(0, "migration to node %u failed with %d\n",
2612 /* migration failed, detach and clean up mle */
2613 dlm_mle_detach_hb_events(dlm
, mle
);
2615 dlm_put_mle_inuse(mle
);
2616 spin_lock(&res
->spinlock
);
2617 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
2619 spin_unlock(&res
->spinlock
);
2623 /* at this point, the target sends a message to all nodes,
2624 * (using dlm_do_migrate_request). this node is skipped since
2625 * we had to put an mle in the list to begin the process. this
2626 * node now waits for target to do an assert master. this node
2627 * will be the last one notified, ensuring that the migration
2628 * is complete everywhere. if the target dies while this is
2629 * going on, some nodes could potentially see the target as the
2630 * master, so it is important that my recovery finds the migration
2631 * mle and sets the master to UNKNONWN. */
2634 /* wait for new node to assert master */
2636 ret
= wait_event_interruptible_timeout(mle
->wq
,
2637 (atomic_read(&mle
->woken
) == 1),
2638 msecs_to_jiffies(5000));
2641 if (atomic_read(&mle
->woken
) == 1 ||
2642 res
->owner
== target
)
2645 mlog(0, "%s:%.*s: timed out during migration\n",
2646 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
);
2647 /* avoid hang during shutdown when migrating lockres
2648 * to a node which also goes down */
2649 if (dlm_is_node_dead(dlm
, target
)) {
2650 mlog(0, "%s:%.*s: expected migration "
2651 "target %u is no longer up, restarting\n",
2652 dlm
->name
, res
->lockname
.len
,
2653 res
->lockname
.name
, target
);
2655 /* migration failed, detach and clean up mle */
2656 dlm_mle_detach_hb_events(dlm
, mle
);
2658 dlm_put_mle_inuse(mle
);
2659 spin_lock(&res
->spinlock
);
2660 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
2662 spin_unlock(&res
->spinlock
);
2666 mlog(0, "%s:%.*s: caught signal during migration\n",
2667 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
);
2670 /* all done, set the owner, clear the flag */
2671 spin_lock(&res
->spinlock
);
2672 dlm_set_lockres_owner(dlm
, res
, target
);
2673 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
2674 dlm_remove_nonlocal_locks(dlm
, res
);
2675 spin_unlock(&res
->spinlock
);
2678 /* master is known, detach if not already detached */
2679 dlm_mle_detach_hb_events(dlm
, mle
);
2680 dlm_put_mle_inuse(mle
);
2683 dlm_lockres_calc_usage(dlm
, res
);
2686 /* re-dirty the lockres if we failed */
2688 dlm_kick_thread(dlm
, res
);
2690 /* wake up waiters if the MIGRATING flag got set
2691 * but migration failed */
2697 free_page((unsigned long)mres
);
2701 mlog(0, "returning %d\n", ret
);
2705 #define DLM_MIGRATION_RETRY_MS 100
2707 /* Should be called only after beginning the domain leave process.
2708 * There should not be any remaining locks on nonlocal lock resources,
2709 * and there should be no local locks left on locally mastered resources.
2711 * Called with the dlm spinlock held, may drop it to do migration, but
2712 * will re-acquire before exit.
2714 * Returns: 1 if dlm->spinlock was dropped/retaken, 0 if never dropped */
2715 int dlm_empty_lockres(struct dlm_ctxt
*dlm
, struct dlm_lock_resource
*res
)
2718 int lock_dropped
= 0;
2721 spin_lock(&res
->spinlock
);
2722 if (res
->owner
!= dlm
->node_num
) {
2723 if (!__dlm_lockres_unused(res
)) {
2724 mlog(ML_ERROR
, "%s:%.*s: this node is not master, "
2725 "trying to free this but locks remain\n",
2726 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
);
2728 spin_unlock(&res
->spinlock
);
2732 /* No need to migrate a lockres having no locks */
2733 ret
= dlm_is_lockres_migrateable(dlm
, res
, &numlocks
);
2734 if (ret
>= 0 && numlocks
== 0) {
2735 spin_unlock(&res
->spinlock
);
2738 spin_unlock(&res
->spinlock
);
2740 /* Wheee! Migrate lockres here! Will sleep so drop spinlock. */
2741 spin_unlock(&dlm
->spinlock
);
2744 ret
= dlm_migrate_lockres(dlm
, res
, O2NM_MAX_NODES
);
2747 if (ret
== -ENOTEMPTY
) {
2748 mlog(ML_ERROR
, "lockres %.*s still has local locks!\n",
2749 res
->lockname
.len
, res
->lockname
.name
);
2753 mlog(0, "lockres %.*s: migrate failed, "
2754 "retrying\n", res
->lockname
.len
,
2755 res
->lockname
.name
);
2756 msleep(DLM_MIGRATION_RETRY_MS
);
2758 spin_lock(&dlm
->spinlock
);
2760 return lock_dropped
;
2763 int dlm_lock_basts_flushed(struct dlm_ctxt
*dlm
, struct dlm_lock
*lock
)
2766 spin_lock(&dlm
->ast_lock
);
2767 spin_lock(&lock
->spinlock
);
2768 ret
= (list_empty(&lock
->bast_list
) && !lock
->bast_pending
);
2769 spin_unlock(&lock
->spinlock
);
2770 spin_unlock(&dlm
->ast_lock
);
2774 static int dlm_migration_can_proceed(struct dlm_ctxt
*dlm
,
2775 struct dlm_lock_resource
*res
,
2779 spin_lock(&res
->spinlock
);
2780 can_proceed
= !!(res
->state
& DLM_LOCK_RES_MIGRATING
);
2781 spin_unlock(&res
->spinlock
);
2783 /* target has died, so make the caller break out of the
2784 * wait_event, but caller must recheck the domain_map */
2785 spin_lock(&dlm
->spinlock
);
2786 if (!test_bit(mig_target
, dlm
->domain_map
))
2788 spin_unlock(&dlm
->spinlock
);
2792 static int dlm_lockres_is_dirty(struct dlm_ctxt
*dlm
,
2793 struct dlm_lock_resource
*res
)
2796 spin_lock(&res
->spinlock
);
2797 ret
= !!(res
->state
& DLM_LOCK_RES_DIRTY
);
2798 spin_unlock(&res
->spinlock
);
2803 static int dlm_mark_lockres_migrating(struct dlm_ctxt
*dlm
,
2804 struct dlm_lock_resource
*res
,
2809 mlog(0, "dlm_mark_lockres_migrating: %.*s, from %u to %u\n",
2810 res
->lockname
.len
, res
->lockname
.name
, dlm
->node_num
,
2812 /* need to set MIGRATING flag on lockres. this is done by
2813 * ensuring that all asts have been flushed for this lockres. */
2814 spin_lock(&res
->spinlock
);
2815 BUG_ON(res
->migration_pending
);
2816 res
->migration_pending
= 1;
2817 /* strategy is to reserve an extra ast then release
2818 * it below, letting the release do all of the work */
2819 __dlm_lockres_reserve_ast(res
);
2820 spin_unlock(&res
->spinlock
);
2822 /* now flush all the pending asts */
2823 dlm_kick_thread(dlm
, res
);
2824 /* before waiting on DIRTY, block processes which may
2825 * try to dirty the lockres before MIGRATING is set */
2826 spin_lock(&res
->spinlock
);
2827 BUG_ON(res
->state
& DLM_LOCK_RES_BLOCK_DIRTY
);
2828 res
->state
|= DLM_LOCK_RES_BLOCK_DIRTY
;
2829 spin_unlock(&res
->spinlock
);
2830 /* now wait on any pending asts and the DIRTY state */
2831 wait_event(dlm
->ast_wq
, !dlm_lockres_is_dirty(dlm
, res
));
2832 dlm_lockres_release_ast(dlm
, res
);
2834 mlog(0, "about to wait on migration_wq, dirty=%s\n",
2835 res
->state
& DLM_LOCK_RES_DIRTY
? "yes" : "no");
2836 /* if the extra ref we just put was the final one, this
2837 * will pass thru immediately. otherwise, we need to wait
2838 * for the last ast to finish. */
2840 ret
= wait_event_interruptible_timeout(dlm
->migration_wq
,
2841 dlm_migration_can_proceed(dlm
, res
, target
),
2842 msecs_to_jiffies(1000));
2844 mlog(0, "woken again: migrating? %s, dead? %s\n",
2845 res
->state
& DLM_LOCK_RES_MIGRATING
? "yes":"no",
2846 test_bit(target
, dlm
->domain_map
) ? "no":"yes");
2848 mlog(0, "all is well: migrating? %s, dead? %s\n",
2849 res
->state
& DLM_LOCK_RES_MIGRATING
? "yes":"no",
2850 test_bit(target
, dlm
->domain_map
) ? "no":"yes");
2852 if (!dlm_migration_can_proceed(dlm
, res
, target
)) {
2853 mlog(0, "trying again...\n");
2856 /* now that we are sure the MIGRATING state is there, drop
2857 * the unneded state which blocked threads trying to DIRTY */
2858 spin_lock(&res
->spinlock
);
2859 BUG_ON(!(res
->state
& DLM_LOCK_RES_BLOCK_DIRTY
));
2860 BUG_ON(!(res
->state
& DLM_LOCK_RES_MIGRATING
));
2861 res
->state
&= ~DLM_LOCK_RES_BLOCK_DIRTY
;
2862 spin_unlock(&res
->spinlock
);
2864 /* did the target go down or die? */
2865 spin_lock(&dlm
->spinlock
);
2866 if (!test_bit(target
, dlm
->domain_map
)) {
2867 mlog(ML_ERROR
, "aha. migration target %u just went down\n",
2871 spin_unlock(&dlm
->spinlock
);
2876 * o the DLM_LOCK_RES_MIGRATING flag is set
2877 * o there are no pending asts on this lockres
2878 * o all processes trying to reserve an ast on this
2879 * lockres must wait for the MIGRATING flag to clear
2884 /* last step in the migration process.
2885 * original master calls this to free all of the dlm_lock
2886 * structures that used to be for other nodes. */
2887 static void dlm_remove_nonlocal_locks(struct dlm_ctxt
*dlm
,
2888 struct dlm_lock_resource
*res
)
2890 struct list_head
*queue
= &res
->granted
;
2892 struct dlm_lock
*lock
, *next
;
2894 assert_spin_locked(&res
->spinlock
);
2896 BUG_ON(res
->owner
== dlm
->node_num
);
2898 for (i
=0; i
<3; i
++) {
2899 list_for_each_entry_safe(lock
, next
, queue
, list
) {
2900 if (lock
->ml
.node
!= dlm
->node_num
) {
2901 mlog(0, "putting lock for node %u\n",
2903 /* be extra careful */
2904 BUG_ON(!list_empty(&lock
->ast_list
));
2905 BUG_ON(!list_empty(&lock
->bast_list
));
2906 BUG_ON(lock
->ast_pending
);
2907 BUG_ON(lock
->bast_pending
);
2908 dlm_lockres_clear_refmap_bit(lock
->ml
.node
, res
);
2909 list_del_init(&lock
->list
);
2911 /* In a normal unlock, we would have added a
2912 * DLM_UNLOCK_FREE_LOCK action. Force it. */
2920 bit
= find_next_bit(res
->refmap
, O2NM_MAX_NODES
, bit
);
2921 if (bit
>= O2NM_MAX_NODES
)
2923 /* do not clear the local node reference, if there is a
2924 * process holding this, let it drop the ref itself */
2925 if (bit
!= dlm
->node_num
) {
2926 mlog(0, "%s:%.*s: node %u had a ref to this "
2927 "migrating lockres, clearing\n", dlm
->name
,
2928 res
->lockname
.len
, res
->lockname
.name
, bit
);
2929 dlm_lockres_clear_refmap_bit(bit
, res
);
2935 /* for now this is not too intelligent. we will
2936 * need stats to make this do the right thing.
2937 * this just finds the first lock on one of the
2938 * queues and uses that node as the target. */
2939 static u8
dlm_pick_migration_target(struct dlm_ctxt
*dlm
,
2940 struct dlm_lock_resource
*res
)
2943 struct list_head
*queue
= &res
->granted
;
2944 struct dlm_lock
*lock
;
2947 assert_spin_locked(&dlm
->spinlock
);
2949 spin_lock(&res
->spinlock
);
2950 for (i
=0; i
<3; i
++) {
2951 list_for_each_entry(lock
, queue
, list
) {
2952 /* up to the caller to make sure this node
2954 if (lock
->ml
.node
!= dlm
->node_num
) {
2955 spin_unlock(&res
->spinlock
);
2956 return lock
->ml
.node
;
2961 spin_unlock(&res
->spinlock
);
2962 mlog(0, "have not found a suitable target yet! checking domain map\n");
2964 /* ok now we're getting desperate. pick anyone alive. */
2967 nodenum
= find_next_bit(dlm
->domain_map
,
2968 O2NM_MAX_NODES
, nodenum
+1);
2969 mlog(0, "found %d in domain map\n", nodenum
);
2970 if (nodenum
>= O2NM_MAX_NODES
)
2972 if (nodenum
!= dlm
->node_num
) {
2973 mlog(0, "picking %d\n", nodenum
);
2978 mlog(0, "giving up. no master to migrate to\n");
2979 return DLM_LOCK_RES_OWNER_UNKNOWN
;
2984 /* this is called by the new master once all lockres
2985 * data has been received */
2986 static int dlm_do_migrate_request(struct dlm_ctxt
*dlm
,
2987 struct dlm_lock_resource
*res
,
2988 u8 master
, u8 new_master
,
2989 struct dlm_node_iter
*iter
)
2991 struct dlm_migrate_request migrate
;
2992 int ret
, skip
, status
= 0;
2995 memset(&migrate
, 0, sizeof(migrate
));
2996 migrate
.namelen
= res
->lockname
.len
;
2997 memcpy(migrate
.name
, res
->lockname
.name
, migrate
.namelen
);
2998 migrate
.new_master
= new_master
;
2999 migrate
.master
= master
;
3003 /* send message to all nodes, except the master and myself */
3004 while ((nodenum
= dlm_node_iter_next(iter
)) >= 0) {
3005 if (nodenum
== master
||
3006 nodenum
== new_master
)
3009 /* We could race exit domain. If exited, skip. */
3010 spin_lock(&dlm
->spinlock
);
3011 skip
= (!test_bit(nodenum
, dlm
->domain_map
));
3012 spin_unlock(&dlm
->spinlock
);
3014 clear_bit(nodenum
, iter
->node_map
);
3018 ret
= o2net_send_message(DLM_MIGRATE_REQUEST_MSG
, dlm
->key
,
3019 &migrate
, sizeof(migrate
), nodenum
,
3022 mlog(0, "migrate_request returned %d!\n", ret
);
3023 if (!dlm_is_host_down(ret
)) {
3024 mlog(ML_ERROR
, "unhandled error=%d!\n", ret
);
3027 clear_bit(nodenum
, iter
->node_map
);
3029 } else if (status
< 0) {
3030 mlog(0, "migrate request (node %u) returned %d!\n",
3033 } else if (status
== DLM_MIGRATE_RESPONSE_MASTERY_REF
) {
3034 /* during the migration request we short-circuited
3035 * the mastery of the lockres. make sure we have
3036 * a mastery ref for nodenum */
3037 mlog(0, "%s:%.*s: need ref for node %u\n",
3038 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
,
3040 spin_lock(&res
->spinlock
);
3041 dlm_lockres_set_refmap_bit(nodenum
, res
);
3042 spin_unlock(&res
->spinlock
);
3049 mlog(0, "returning ret=%d\n", ret
);
3054 /* if there is an existing mle for this lockres, we now know who the master is.
3055 * (the one who sent us *this* message) we can clear it up right away.
3056 * since the process that put the mle on the list still has a reference to it,
3057 * we can unhash it now, set the master and wake the process. as a result,
3058 * we will have no mle in the list to start with. now we can add an mle for
3059 * the migration and this should be the only one found for those scanning the
3061 int dlm_migrate_request_handler(struct o2net_msg
*msg
, u32 len
, void *data
,
3064 struct dlm_ctxt
*dlm
= data
;
3065 struct dlm_lock_resource
*res
= NULL
;
3066 struct dlm_migrate_request
*migrate
= (struct dlm_migrate_request
*) msg
->buf
;
3067 struct dlm_master_list_entry
*mle
= NULL
, *oldmle
= NULL
;
3069 unsigned int namelen
, hash
;
3075 name
= migrate
->name
;
3076 namelen
= migrate
->namelen
;
3077 hash
= dlm_lockid_hash(name
, namelen
);
3079 /* preallocate.. if this fails, abort */
3080 mle
= (struct dlm_master_list_entry
*) kmem_cache_alloc(dlm_mle_cache
,
3088 /* check for pre-existing lock */
3089 spin_lock(&dlm
->spinlock
);
3090 res
= __dlm_lookup_lockres(dlm
, name
, namelen
, hash
);
3091 spin_lock(&dlm
->master_lock
);
3094 spin_lock(&res
->spinlock
);
3095 if (res
->state
& DLM_LOCK_RES_RECOVERING
) {
3096 /* if all is working ok, this can only mean that we got
3097 * a migrate request from a node that we now see as
3098 * dead. what can we do here? drop it to the floor? */
3099 spin_unlock(&res
->spinlock
);
3100 mlog(ML_ERROR
, "Got a migrate request, but the "
3101 "lockres is marked as recovering!");
3102 kmem_cache_free(dlm_mle_cache
, mle
);
3103 ret
= -EINVAL
; /* need a better solution */
3106 res
->state
|= DLM_LOCK_RES_MIGRATING
;
3107 spin_unlock(&res
->spinlock
);
3110 /* ignore status. only nonzero status would BUG. */
3111 ret
= dlm_add_migration_mle(dlm
, res
, mle
, &oldmle
,
3113 migrate
->new_master
,
3117 spin_unlock(&dlm
->master_lock
);
3118 spin_unlock(&dlm
->spinlock
);
3121 /* master is known, detach if not already detached */
3122 dlm_mle_detach_hb_events(dlm
, oldmle
);
3123 dlm_put_mle(oldmle
);
3127 dlm_lockres_put(res
);
3133 /* must be holding dlm->spinlock and dlm->master_lock
3134 * when adding a migration mle, we can clear any other mles
3135 * in the master list because we know with certainty that
3136 * the master is "master". so we remove any old mle from
3137 * the list after setting it's master field, and then add
3138 * the new migration mle. this way we can hold with the rule
3139 * of having only one mle for a given lock name at all times. */
3140 static int dlm_add_migration_mle(struct dlm_ctxt
*dlm
,
3141 struct dlm_lock_resource
*res
,
3142 struct dlm_master_list_entry
*mle
,
3143 struct dlm_master_list_entry
**oldmle
,
3144 const char *name
, unsigned int namelen
,
3145 u8 new_master
, u8 master
)
3154 assert_spin_locked(&dlm
->spinlock
);
3155 assert_spin_locked(&dlm
->master_lock
);
3157 /* caller is responsible for any ref taken here on oldmle */
3158 found
= dlm_find_mle(dlm
, oldmle
, (char *)name
, namelen
);
3160 struct dlm_master_list_entry
*tmp
= *oldmle
;
3161 spin_lock(&tmp
->spinlock
);
3162 if (tmp
->type
== DLM_MLE_MIGRATION
) {
3163 if (master
== dlm
->node_num
) {
3164 /* ah another process raced me to it */
3165 mlog(0, "tried to migrate %.*s, but some "
3166 "process beat me to it\n",
3170 /* bad. 2 NODES are trying to migrate! */
3171 mlog(ML_ERROR
, "migration error mle: "
3172 "master=%u new_master=%u // request: "
3173 "master=%u new_master=%u // "
3175 tmp
->master
, tmp
->new_master
,
3181 /* this is essentially what assert_master does */
3182 tmp
->master
= master
;
3183 atomic_set(&tmp
->woken
, 1);
3185 /* remove it so that only one mle will be found */
3186 __dlm_unlink_mle(dlm
, tmp
);
3187 __dlm_mle_detach_hb_events(dlm
, tmp
);
3188 ret
= DLM_MIGRATE_RESPONSE_MASTERY_REF
;
3189 mlog(0, "%s:%.*s: master=%u, newmaster=%u, "
3190 "telling master to get ref for cleared out mle "
3191 "during migration\n", dlm
->name
, namelen
, name
,
3192 master
, new_master
);
3194 spin_unlock(&tmp
->spinlock
);
3197 /* now add a migration mle to the tail of the list */
3198 dlm_init_mle(mle
, DLM_MLE_MIGRATION
, dlm
, res
, name
, namelen
);
3199 mle
->new_master
= new_master
;
3200 /* the new master will be sending an assert master for this.
3201 * at that point we will get the refmap reference */
3202 mle
->master
= master
;
3203 /* do this for consistency with other mle types */
3204 set_bit(new_master
, mle
->maybe_map
);
3205 __dlm_insert_mle(dlm
, mle
);
3211 * Sets the owner of the lockres, associated to the mle, to UNKNOWN
3213 static struct dlm_lock_resource
*dlm_reset_mleres_owner(struct dlm_ctxt
*dlm
,
3214 struct dlm_master_list_entry
*mle
)
3216 struct dlm_lock_resource
*res
;
3219 /* Find the lockres associated to the mle and set its owner to UNK */
3220 hash
= dlm_lockid_hash(mle
->u
.mlename
.name
, mle
->u
.mlename
.len
);
3221 res
= __dlm_lookup_lockres(dlm
, mle
->u
.mlename
.name
, mle
->u
.mlename
.len
,
3224 spin_unlock(&dlm
->master_lock
);
3226 /* move lockres onto recovery list */
3227 spin_lock(&res
->spinlock
);
3228 dlm_set_lockres_owner(dlm
, res
, DLM_LOCK_RES_OWNER_UNKNOWN
);
3229 dlm_move_lockres_to_recovery_list(dlm
, res
);
3230 spin_unlock(&res
->spinlock
);
3231 dlm_lockres_put(res
);
3233 /* about to get rid of mle, detach from heartbeat */
3234 __dlm_mle_detach_hb_events(dlm
, mle
);
3237 spin_lock(&dlm
->master_lock
);
3239 spin_unlock(&dlm
->master_lock
);
3245 static void dlm_clean_migration_mle(struct dlm_ctxt
*dlm
,
3246 struct dlm_master_list_entry
*mle
)
3248 __dlm_mle_detach_hb_events(dlm
, mle
);
3250 spin_lock(&mle
->spinlock
);
3251 __dlm_unlink_mle(dlm
, mle
);
3252 atomic_set(&mle
->woken
, 1);
3253 spin_unlock(&mle
->spinlock
);
3258 static void dlm_clean_block_mle(struct dlm_ctxt
*dlm
,
3259 struct dlm_master_list_entry
*mle
, u8 dead_node
)
3263 BUG_ON(mle
->type
!= DLM_MLE_BLOCK
);
3265 spin_lock(&mle
->spinlock
);
3266 bit
= find_next_bit(mle
->maybe_map
, O2NM_MAX_NODES
, 0);
3267 if (bit
!= dead_node
) {
3268 mlog(0, "mle found, but dead node %u would not have been "
3269 "master\n", dead_node
);
3270 spin_unlock(&mle
->spinlock
);
3272 /* Must drop the refcount by one since the assert_master will
3273 * never arrive. This may result in the mle being unlinked and
3274 * freed, but there may still be a process waiting in the
3275 * dlmlock path which is fine. */
3276 mlog(0, "node %u was expected master\n", dead_node
);
3277 atomic_set(&mle
->woken
, 1);
3278 spin_unlock(&mle
->spinlock
);
3281 /* Do not need events any longer, so detach from heartbeat */
3282 __dlm_mle_detach_hb_events(dlm
, mle
);
3287 void dlm_clean_master_list(struct dlm_ctxt
*dlm
, u8 dead_node
)
3289 struct dlm_master_list_entry
*mle
, *next
;
3290 struct dlm_lock_resource
*res
;
3292 mlog_entry("dlm=%s, dead node=%u\n", dlm
->name
, dead_node
);
3294 assert_spin_locked(&dlm
->spinlock
);
3296 /* clean the master list */
3297 spin_lock(&dlm
->master_lock
);
3298 list_for_each_entry_safe(mle
, next
, &dlm
->master_list
, list
) {
3299 BUG_ON(mle
->type
!= DLM_MLE_BLOCK
&&
3300 mle
->type
!= DLM_MLE_MASTER
&&
3301 mle
->type
!= DLM_MLE_MIGRATION
);
3303 /* MASTER mles are initiated locally. the waiting
3304 * process will notice the node map change
3305 * shortly. let that happen as normal. */
3306 if (mle
->type
== DLM_MLE_MASTER
)
3310 /* BLOCK mles are initiated by other nodes.
3311 * need to clean up if the dead node would have
3312 * been the master. */
3313 if (mle
->type
== DLM_MLE_BLOCK
) {
3314 dlm_clean_block_mle(dlm
, mle
, dead_node
);
3318 /* everything else is a MIGRATION mle */
3320 /* the rule for MIGRATION mles is that the master
3321 * becomes UNKNOWN if *either* the original or
3322 * the new master dies. all UNKNOWN lockreses
3323 * are sent to whichever node becomes the recovery
3324 * master. the new master is responsible for
3325 * determining if there is still a master for
3326 * this lockres, or if he needs to take over
3327 * mastery. either way, this node should expect
3328 * another message to resolve this. */
3329 if (mle
->master
!= dead_node
&&
3330 mle
->new_master
!= dead_node
)
3333 /* if we have reached this point, this mle needs to
3334 * be removed from the list and freed. */
3335 dlm_clean_migration_mle(dlm
, mle
);
3337 mlog(0, "%s: node %u died during migration from "
3338 "%u to %u!\n", dlm
->name
, dead_node
,
3339 mle
->master
, mle
->new_master
);
3341 /* If we find a lockres associated with the mle, we've
3342 * hit this rare case that messes up our lock ordering.
3343 * If so, we need to drop the master lock so that we can
3344 * take the lockres lock, meaning that we will have to
3345 * restart from the head of list. */
3346 res
= dlm_reset_mleres_owner(dlm
, mle
);
3351 /* this may be the last reference */
3354 spin_unlock(&dlm
->master_lock
);
3358 int dlm_finish_migration(struct dlm_ctxt
*dlm
, struct dlm_lock_resource
*res
,
3361 struct dlm_node_iter iter
;
3364 spin_lock(&dlm
->spinlock
);
3365 dlm_node_iter_init(dlm
->domain_map
, &iter
);
3366 clear_bit(old_master
, iter
.node_map
);
3367 clear_bit(dlm
->node_num
, iter
.node_map
);
3368 spin_unlock(&dlm
->spinlock
);
3370 /* ownership of the lockres is changing. account for the
3371 * mastery reference here since old_master will briefly have
3372 * a reference after the migration completes */
3373 spin_lock(&res
->spinlock
);
3374 dlm_lockres_set_refmap_bit(old_master
, res
);
3375 spin_unlock(&res
->spinlock
);
3377 mlog(0, "now time to do a migrate request to other nodes\n");
3378 ret
= dlm_do_migrate_request(dlm
, res
, old_master
,
3379 dlm
->node_num
, &iter
);
3385 mlog(0, "doing assert master of %.*s to all except the original node\n",
3386 res
->lockname
.len
, res
->lockname
.name
);
3387 /* this call now finishes out the nodemap
3388 * even if one or more nodes die */
3389 ret
= dlm_do_assert_master(dlm
, res
, iter
.node_map
,
3390 DLM_ASSERT_MASTER_FINISH_MIGRATION
);
3392 /* no longer need to retry. all living nodes contacted. */
3397 memset(iter
.node_map
, 0, sizeof(iter
.node_map
));
3398 set_bit(old_master
, iter
.node_map
);
3399 mlog(0, "doing assert master of %.*s back to %u\n",
3400 res
->lockname
.len
, res
->lockname
.name
, old_master
);
3401 ret
= dlm_do_assert_master(dlm
, res
, iter
.node_map
,
3402 DLM_ASSERT_MASTER_FINISH_MIGRATION
);
3404 mlog(0, "assert master to original master failed "
3406 /* the only nonzero status here would be because of
3407 * a dead original node. we're done. */
3411 /* all done, set the owner, clear the flag */
3412 spin_lock(&res
->spinlock
);
3413 dlm_set_lockres_owner(dlm
, res
, dlm
->node_num
);
3414 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
3415 spin_unlock(&res
->spinlock
);
3416 /* re-dirty it on the new master */
3417 dlm_kick_thread(dlm
, res
);
3424 * LOCKRES AST REFCOUNT
3425 * this is integral to migration
3428 /* for future intent to call an ast, reserve one ahead of time.
3429 * this should be called only after waiting on the lockres
3430 * with dlm_wait_on_lockres, and while still holding the
3431 * spinlock after the call. */
3432 void __dlm_lockres_reserve_ast(struct dlm_lock_resource
*res
)
3434 assert_spin_locked(&res
->spinlock
);
3435 if (res
->state
& DLM_LOCK_RES_MIGRATING
) {
3436 __dlm_print_one_lock_resource(res
);
3438 BUG_ON(res
->state
& DLM_LOCK_RES_MIGRATING
);
3440 atomic_inc(&res
->asts_reserved
);
3444 * used to drop the reserved ast, either because it went unused,
3445 * or because the ast/bast was actually called.
3447 * also, if there is a pending migration on this lockres,
3448 * and this was the last pending ast on the lockres,
3449 * atomically set the MIGRATING flag before we drop the lock.
3450 * this is how we ensure that migration can proceed with no
3451 * asts in progress. note that it is ok if the state of the
3452 * queues is such that a lock should be granted in the future
3453 * or that a bast should be fired, because the new master will
3454 * shuffle the lists on this lockres as soon as it is migrated.
3456 void dlm_lockres_release_ast(struct dlm_ctxt
*dlm
,
3457 struct dlm_lock_resource
*res
)
3459 if (!atomic_dec_and_lock(&res
->asts_reserved
, &res
->spinlock
))
3462 if (!res
->migration_pending
) {
3463 spin_unlock(&res
->spinlock
);
3467 BUG_ON(res
->state
& DLM_LOCK_RES_MIGRATING
);
3468 res
->migration_pending
= 0;
3469 res
->state
|= DLM_LOCK_RES_MIGRATING
;
3470 spin_unlock(&res
->spinlock
);
3472 wake_up(&dlm
->migration_wq
);