1 /* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
6 * standalone DLM module
8 * Copyright (C) 2004 Oracle. All rights reserved.
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public
12 * License as published by the Free Software Foundation; either
13 * version 2 of the License, or (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
20 * You should have received a copy of the GNU General Public
21 * License along with this program; if not, write to the
22 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 * Boston, MA 021110-1307, USA.
28 #include <linux/module.h>
30 #include <linux/types.h>
31 #include <linux/slab.h>
32 #include <linux/highmem.h>
33 #include <linux/init.h>
34 #include <linux/sysctl.h>
35 #include <linux/random.h>
36 #include <linux/blkdev.h>
37 #include <linux/socket.h>
38 #include <linux/inet.h>
39 #include <linux/spinlock.h>
40 #include <linux/delay.h>
43 #include "cluster/heartbeat.h"
44 #include "cluster/nodemanager.h"
45 #include "cluster/tcp.h"
48 #include "dlmcommon.h"
49 #include "dlmdomain.h"
52 #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_MASTER)
53 #include "cluster/masklog.h"
55 static void dlm_mle_node_down(struct dlm_ctxt
*dlm
,
56 struct dlm_master_list_entry
*mle
,
57 struct o2nm_node
*node
,
59 static void dlm_mle_node_up(struct dlm_ctxt
*dlm
,
60 struct dlm_master_list_entry
*mle
,
61 struct o2nm_node
*node
,
64 static void dlm_assert_master_worker(struct dlm_work_item
*item
, void *data
);
65 static int dlm_do_assert_master(struct dlm_ctxt
*dlm
,
66 struct dlm_lock_resource
*res
,
67 void *nodemap
, u32 flags
);
68 static void dlm_deref_lockres_worker(struct dlm_work_item
*item
, void *data
);
70 static inline int dlm_mle_equal(struct dlm_ctxt
*dlm
,
71 struct dlm_master_list_entry
*mle
,
78 if (namelen
!= mle
->mnamelen
||
79 memcmp(name
, mle
->mname
, namelen
) != 0)
85 static struct kmem_cache
*dlm_lockres_cache
;
86 static struct kmem_cache
*dlm_lockname_cache
;
87 static struct kmem_cache
*dlm_mle_cache
;
89 static void dlm_mle_release(struct kref
*kref
);
90 static void dlm_init_mle(struct dlm_master_list_entry
*mle
,
91 enum dlm_mle_type type
,
93 struct dlm_lock_resource
*res
,
95 unsigned int namelen
);
96 static void dlm_put_mle(struct dlm_master_list_entry
*mle
);
97 static void __dlm_put_mle(struct dlm_master_list_entry
*mle
);
98 static int dlm_find_mle(struct dlm_ctxt
*dlm
,
99 struct dlm_master_list_entry
**mle
,
100 char *name
, unsigned int namelen
);
102 static int dlm_do_master_request(struct dlm_lock_resource
*res
,
103 struct dlm_master_list_entry
*mle
, int to
);
106 static int dlm_wait_for_lock_mastery(struct dlm_ctxt
*dlm
,
107 struct dlm_lock_resource
*res
,
108 struct dlm_master_list_entry
*mle
,
110 static int dlm_restart_lock_mastery(struct dlm_ctxt
*dlm
,
111 struct dlm_lock_resource
*res
,
112 struct dlm_master_list_entry
*mle
,
114 static int dlm_add_migration_mle(struct dlm_ctxt
*dlm
,
115 struct dlm_lock_resource
*res
,
116 struct dlm_master_list_entry
*mle
,
117 struct dlm_master_list_entry
**oldmle
,
118 const char *name
, unsigned int namelen
,
119 u8 new_master
, u8 master
);
121 static u8
dlm_pick_migration_target(struct dlm_ctxt
*dlm
,
122 struct dlm_lock_resource
*res
);
123 static void dlm_remove_nonlocal_locks(struct dlm_ctxt
*dlm
,
124 struct dlm_lock_resource
*res
);
125 static int dlm_mark_lockres_migrating(struct dlm_ctxt
*dlm
,
126 struct dlm_lock_resource
*res
,
128 static int dlm_pre_master_reco_lockres(struct dlm_ctxt
*dlm
,
129 struct dlm_lock_resource
*res
);
132 int dlm_is_host_down(int errno
)
149 case -EINVAL
: /* if returned from our tcp code,
150 this means there is no socket */
158 * MASTER LIST FUNCTIONS
163 * regarding master list entries and heartbeat callbacks:
165 * in order to avoid sleeping and allocation that occurs in
166 * heartbeat, master list entries are simply attached to the
167 * dlm's established heartbeat callbacks. the mle is attached
168 * when it is created, and since the dlm->spinlock is held at
169 * that time, any heartbeat event will be properly discovered
170 * by the mle. the mle needs to be detached from the
171 * dlm->mle_hb_events list as soon as heartbeat events are no
172 * longer useful to the mle, and before the mle is freed.
174 * as a general rule, heartbeat events are no longer needed by
175 * the mle once an "answer" regarding the lock master has been
178 static inline void __dlm_mle_attach_hb_events(struct dlm_ctxt
*dlm
,
179 struct dlm_master_list_entry
*mle
)
181 assert_spin_locked(&dlm
->spinlock
);
183 list_add_tail(&mle
->hb_events
, &dlm
->mle_hb_events
);
187 static inline void __dlm_mle_detach_hb_events(struct dlm_ctxt
*dlm
,
188 struct dlm_master_list_entry
*mle
)
190 if (!list_empty(&mle
->hb_events
))
191 list_del_init(&mle
->hb_events
);
195 static inline void dlm_mle_detach_hb_events(struct dlm_ctxt
*dlm
,
196 struct dlm_master_list_entry
*mle
)
198 spin_lock(&dlm
->spinlock
);
199 __dlm_mle_detach_hb_events(dlm
, mle
);
200 spin_unlock(&dlm
->spinlock
);
203 static void dlm_get_mle_inuse(struct dlm_master_list_entry
*mle
)
205 struct dlm_ctxt
*dlm
;
208 assert_spin_locked(&dlm
->spinlock
);
209 assert_spin_locked(&dlm
->master_lock
);
211 kref_get(&mle
->mle_refs
);
214 static void dlm_put_mle_inuse(struct dlm_master_list_entry
*mle
)
216 struct dlm_ctxt
*dlm
;
219 spin_lock(&dlm
->spinlock
);
220 spin_lock(&dlm
->master_lock
);
223 spin_unlock(&dlm
->master_lock
);
224 spin_unlock(&dlm
->spinlock
);
228 /* remove from list and free */
229 static void __dlm_put_mle(struct dlm_master_list_entry
*mle
)
231 struct dlm_ctxt
*dlm
;
234 assert_spin_locked(&dlm
->spinlock
);
235 assert_spin_locked(&dlm
->master_lock
);
236 if (!atomic_read(&mle
->mle_refs
.refcount
)) {
237 /* this may or may not crash, but who cares.
239 mlog(ML_ERROR
, "bad mle: %p\n", mle
);
240 dlm_print_one_mle(mle
);
243 kref_put(&mle
->mle_refs
, dlm_mle_release
);
247 /* must not have any spinlocks coming in */
248 static void dlm_put_mle(struct dlm_master_list_entry
*mle
)
250 struct dlm_ctxt
*dlm
;
253 spin_lock(&dlm
->spinlock
);
254 spin_lock(&dlm
->master_lock
);
256 spin_unlock(&dlm
->master_lock
);
257 spin_unlock(&dlm
->spinlock
);
260 static inline void dlm_get_mle(struct dlm_master_list_entry
*mle
)
262 kref_get(&mle
->mle_refs
);
265 static void dlm_init_mle(struct dlm_master_list_entry
*mle
,
266 enum dlm_mle_type type
,
267 struct dlm_ctxt
*dlm
,
268 struct dlm_lock_resource
*res
,
270 unsigned int namelen
)
272 assert_spin_locked(&dlm
->spinlock
);
276 INIT_HLIST_NODE(&mle
->master_hash_node
);
277 INIT_LIST_HEAD(&mle
->hb_events
);
278 memset(mle
->maybe_map
, 0, sizeof(mle
->maybe_map
));
279 spin_lock_init(&mle
->spinlock
);
280 init_waitqueue_head(&mle
->wq
);
281 atomic_set(&mle
->woken
, 0);
282 kref_init(&mle
->mle_refs
);
283 memset(mle
->response_map
, 0, sizeof(mle
->response_map
));
284 mle
->master
= O2NM_MAX_NODES
;
285 mle
->new_master
= O2NM_MAX_NODES
;
288 BUG_ON(mle
->type
!= DLM_MLE_BLOCK
&&
289 mle
->type
!= DLM_MLE_MASTER
&&
290 mle
->type
!= DLM_MLE_MIGRATION
);
292 if (mle
->type
== DLM_MLE_MASTER
) {
295 memcpy(mle
->mname
, res
->lockname
.name
, res
->lockname
.len
);
296 mle
->mnamelen
= res
->lockname
.len
;
297 mle
->mnamehash
= res
->lockname
.hash
;
301 memcpy(mle
->mname
, name
, namelen
);
302 mle
->mnamelen
= namelen
;
303 mle
->mnamehash
= dlm_lockid_hash(name
, namelen
);
306 atomic_inc(&dlm
->mle_tot_count
[mle
->type
]);
307 atomic_inc(&dlm
->mle_cur_count
[mle
->type
]);
309 /* copy off the node_map and register hb callbacks on our copy */
310 memcpy(mle
->node_map
, dlm
->domain_map
, sizeof(mle
->node_map
));
311 memcpy(mle
->vote_map
, dlm
->domain_map
, sizeof(mle
->vote_map
));
312 clear_bit(dlm
->node_num
, mle
->vote_map
);
313 clear_bit(dlm
->node_num
, mle
->node_map
);
315 /* attach the mle to the domain node up/down events */
316 __dlm_mle_attach_hb_events(dlm
, mle
);
319 void __dlm_unlink_mle(struct dlm_ctxt
*dlm
, struct dlm_master_list_entry
*mle
)
321 assert_spin_locked(&dlm
->spinlock
);
322 assert_spin_locked(&dlm
->master_lock
);
324 if (!hlist_unhashed(&mle
->master_hash_node
))
325 hlist_del_init(&mle
->master_hash_node
);
328 void __dlm_insert_mle(struct dlm_ctxt
*dlm
, struct dlm_master_list_entry
*mle
)
330 struct hlist_head
*bucket
;
332 assert_spin_locked(&dlm
->master_lock
);
334 bucket
= dlm_master_hash(dlm
, mle
->mnamehash
);
335 hlist_add_head(&mle
->master_hash_node
, bucket
);
338 /* returns 1 if found, 0 if not */
339 static int dlm_find_mle(struct dlm_ctxt
*dlm
,
340 struct dlm_master_list_entry
**mle
,
341 char *name
, unsigned int namelen
)
343 struct dlm_master_list_entry
*tmpmle
;
344 struct hlist_head
*bucket
;
347 assert_spin_locked(&dlm
->master_lock
);
349 hash
= dlm_lockid_hash(name
, namelen
);
350 bucket
= dlm_master_hash(dlm
, hash
);
351 hlist_for_each_entry(tmpmle
, bucket
, master_hash_node
) {
352 if (!dlm_mle_equal(dlm
, tmpmle
, name
, namelen
))
361 void dlm_hb_event_notify_attached(struct dlm_ctxt
*dlm
, int idx
, int node_up
)
363 struct dlm_master_list_entry
*mle
;
365 assert_spin_locked(&dlm
->spinlock
);
367 list_for_each_entry(mle
, &dlm
->mle_hb_events
, hb_events
) {
369 dlm_mle_node_up(dlm
, mle
, NULL
, idx
);
371 dlm_mle_node_down(dlm
, mle
, NULL
, idx
);
375 static void dlm_mle_node_down(struct dlm_ctxt
*dlm
,
376 struct dlm_master_list_entry
*mle
,
377 struct o2nm_node
*node
, int idx
)
379 spin_lock(&mle
->spinlock
);
381 if (!test_bit(idx
, mle
->node_map
))
382 mlog(0, "node %u already removed from nodemap!\n", idx
);
384 clear_bit(idx
, mle
->node_map
);
386 spin_unlock(&mle
->spinlock
);
389 static void dlm_mle_node_up(struct dlm_ctxt
*dlm
,
390 struct dlm_master_list_entry
*mle
,
391 struct o2nm_node
*node
, int idx
)
393 spin_lock(&mle
->spinlock
);
395 if (test_bit(idx
, mle
->node_map
))
396 mlog(0, "node %u already in node map!\n", idx
);
398 set_bit(idx
, mle
->node_map
);
400 spin_unlock(&mle
->spinlock
);
404 int dlm_init_mle_cache(void)
406 dlm_mle_cache
= kmem_cache_create("o2dlm_mle",
407 sizeof(struct dlm_master_list_entry
),
408 0, SLAB_HWCACHE_ALIGN
,
410 if (dlm_mle_cache
== NULL
)
415 void dlm_destroy_mle_cache(void)
418 kmem_cache_destroy(dlm_mle_cache
);
421 static void dlm_mle_release(struct kref
*kref
)
423 struct dlm_master_list_entry
*mle
;
424 struct dlm_ctxt
*dlm
;
426 mle
= container_of(kref
, struct dlm_master_list_entry
, mle_refs
);
429 assert_spin_locked(&dlm
->spinlock
);
430 assert_spin_locked(&dlm
->master_lock
);
432 mlog(0, "Releasing mle for %.*s, type %d\n", mle
->mnamelen
, mle
->mname
,
435 /* remove from list if not already */
436 __dlm_unlink_mle(dlm
, mle
);
438 /* detach the mle from the domain node up/down events */
439 __dlm_mle_detach_hb_events(dlm
, mle
);
441 atomic_dec(&dlm
->mle_cur_count
[mle
->type
]);
443 /* NOTE: kfree under spinlock here.
444 * if this is bad, we can move this to a freelist. */
445 kmem_cache_free(dlm_mle_cache
, mle
);
450 * LOCK RESOURCE FUNCTIONS
453 int dlm_init_master_caches(void)
455 dlm_lockres_cache
= kmem_cache_create("o2dlm_lockres",
456 sizeof(struct dlm_lock_resource
),
457 0, SLAB_HWCACHE_ALIGN
, NULL
);
458 if (!dlm_lockres_cache
)
461 dlm_lockname_cache
= kmem_cache_create("o2dlm_lockname",
462 DLM_LOCKID_NAME_MAX
, 0,
463 SLAB_HWCACHE_ALIGN
, NULL
);
464 if (!dlm_lockname_cache
)
469 dlm_destroy_master_caches();
473 void dlm_destroy_master_caches(void)
475 if (dlm_lockname_cache
) {
476 kmem_cache_destroy(dlm_lockname_cache
);
477 dlm_lockname_cache
= NULL
;
480 if (dlm_lockres_cache
) {
481 kmem_cache_destroy(dlm_lockres_cache
);
482 dlm_lockres_cache
= NULL
;
486 static void dlm_lockres_release(struct kref
*kref
)
488 struct dlm_lock_resource
*res
;
489 struct dlm_ctxt
*dlm
;
491 res
= container_of(kref
, struct dlm_lock_resource
, refs
);
494 /* This should not happen -- all lockres' have a name
495 * associated with them at init time. */
496 BUG_ON(!res
->lockname
.name
);
498 mlog(0, "destroying lockres %.*s\n", res
->lockname
.len
,
501 spin_lock(&dlm
->track_lock
);
502 if (!list_empty(&res
->tracking
))
503 list_del_init(&res
->tracking
);
505 mlog(ML_ERROR
, "Resource %.*s not on the Tracking list\n",
506 res
->lockname
.len
, res
->lockname
.name
);
507 dlm_print_one_lock_resource(res
);
509 spin_unlock(&dlm
->track_lock
);
511 atomic_dec(&dlm
->res_cur_count
);
513 if (!hlist_unhashed(&res
->hash_node
) ||
514 !list_empty(&res
->granted
) ||
515 !list_empty(&res
->converting
) ||
516 !list_empty(&res
->blocked
) ||
517 !list_empty(&res
->dirty
) ||
518 !list_empty(&res
->recovering
) ||
519 !list_empty(&res
->purge
)) {
521 "Going to BUG for resource %.*s."
522 " We're on a list! [%c%c%c%c%c%c%c]\n",
523 res
->lockname
.len
, res
->lockname
.name
,
524 !hlist_unhashed(&res
->hash_node
) ? 'H' : ' ',
525 !list_empty(&res
->granted
) ? 'G' : ' ',
526 !list_empty(&res
->converting
) ? 'C' : ' ',
527 !list_empty(&res
->blocked
) ? 'B' : ' ',
528 !list_empty(&res
->dirty
) ? 'D' : ' ',
529 !list_empty(&res
->recovering
) ? 'R' : ' ',
530 !list_empty(&res
->purge
) ? 'P' : ' ');
532 dlm_print_one_lock_resource(res
);
535 /* By the time we're ready to blow this guy away, we shouldn't
536 * be on any lists. */
537 BUG_ON(!hlist_unhashed(&res
->hash_node
));
538 BUG_ON(!list_empty(&res
->granted
));
539 BUG_ON(!list_empty(&res
->converting
));
540 BUG_ON(!list_empty(&res
->blocked
));
541 BUG_ON(!list_empty(&res
->dirty
));
542 BUG_ON(!list_empty(&res
->recovering
));
543 BUG_ON(!list_empty(&res
->purge
));
545 kmem_cache_free(dlm_lockname_cache
, (void *)res
->lockname
.name
);
547 kmem_cache_free(dlm_lockres_cache
, res
);
550 void dlm_lockres_put(struct dlm_lock_resource
*res
)
552 kref_put(&res
->refs
, dlm_lockres_release
);
555 static void dlm_init_lockres(struct dlm_ctxt
*dlm
,
556 struct dlm_lock_resource
*res
,
557 const char *name
, unsigned int namelen
)
561 /* If we memset here, we lose our reference to the kmalloc'd
562 * res->lockname.name, so be sure to init every field
565 qname
= (char *) res
->lockname
.name
;
566 memcpy(qname
, name
, namelen
);
568 res
->lockname
.len
= namelen
;
569 res
->lockname
.hash
= dlm_lockid_hash(name
, namelen
);
571 init_waitqueue_head(&res
->wq
);
572 spin_lock_init(&res
->spinlock
);
573 INIT_HLIST_NODE(&res
->hash_node
);
574 INIT_LIST_HEAD(&res
->granted
);
575 INIT_LIST_HEAD(&res
->converting
);
576 INIT_LIST_HEAD(&res
->blocked
);
577 INIT_LIST_HEAD(&res
->dirty
);
578 INIT_LIST_HEAD(&res
->recovering
);
579 INIT_LIST_HEAD(&res
->purge
);
580 INIT_LIST_HEAD(&res
->tracking
);
581 atomic_set(&res
->asts_reserved
, 0);
582 res
->migration_pending
= 0;
583 res
->inflight_locks
= 0;
584 res
->inflight_assert_workers
= 0;
588 kref_init(&res
->refs
);
590 atomic_inc(&dlm
->res_tot_count
);
591 atomic_inc(&dlm
->res_cur_count
);
593 /* just for consistency */
594 spin_lock(&res
->spinlock
);
595 dlm_set_lockres_owner(dlm
, res
, DLM_LOCK_RES_OWNER_UNKNOWN
);
596 spin_unlock(&res
->spinlock
);
598 res
->state
= DLM_LOCK_RES_IN_PROGRESS
;
602 spin_lock(&dlm
->spinlock
);
603 list_add_tail(&res
->tracking
, &dlm
->tracking_list
);
604 spin_unlock(&dlm
->spinlock
);
606 memset(res
->lvb
, 0, DLM_LVB_LEN
);
607 memset(res
->refmap
, 0, sizeof(res
->refmap
));
610 struct dlm_lock_resource
*dlm_new_lockres(struct dlm_ctxt
*dlm
,
612 unsigned int namelen
)
614 struct dlm_lock_resource
*res
= NULL
;
616 res
= kmem_cache_zalloc(dlm_lockres_cache
, GFP_NOFS
);
620 res
->lockname
.name
= kmem_cache_zalloc(dlm_lockname_cache
, GFP_NOFS
);
621 if (!res
->lockname
.name
)
624 dlm_init_lockres(dlm
, res
, name
, namelen
);
629 kmem_cache_free(dlm_lockres_cache
, res
);
633 void dlm_lockres_set_refmap_bit(struct dlm_ctxt
*dlm
,
634 struct dlm_lock_resource
*res
, int bit
)
636 assert_spin_locked(&res
->spinlock
);
638 mlog(0, "res %.*s, set node %u, %ps()\n", res
->lockname
.len
,
639 res
->lockname
.name
, bit
, __builtin_return_address(0));
641 set_bit(bit
, res
->refmap
);
644 void dlm_lockres_clear_refmap_bit(struct dlm_ctxt
*dlm
,
645 struct dlm_lock_resource
*res
, int bit
)
647 assert_spin_locked(&res
->spinlock
);
649 mlog(0, "res %.*s, clr node %u, %ps()\n", res
->lockname
.len
,
650 res
->lockname
.name
, bit
, __builtin_return_address(0));
652 clear_bit(bit
, res
->refmap
);
655 static void __dlm_lockres_grab_inflight_ref(struct dlm_ctxt
*dlm
,
656 struct dlm_lock_resource
*res
)
658 res
->inflight_locks
++;
660 mlog(0, "%s: res %.*s, inflight++: now %u, %ps()\n", dlm
->name
,
661 res
->lockname
.len
, res
->lockname
.name
, res
->inflight_locks
,
662 __builtin_return_address(0));
665 void dlm_lockres_grab_inflight_ref(struct dlm_ctxt
*dlm
,
666 struct dlm_lock_resource
*res
)
668 assert_spin_locked(&res
->spinlock
);
669 __dlm_lockres_grab_inflight_ref(dlm
, res
);
672 void dlm_lockres_drop_inflight_ref(struct dlm_ctxt
*dlm
,
673 struct dlm_lock_resource
*res
)
675 assert_spin_locked(&res
->spinlock
);
677 BUG_ON(res
->inflight_locks
== 0);
679 res
->inflight_locks
--;
681 mlog(0, "%s: res %.*s, inflight--: now %u, %ps()\n", dlm
->name
,
682 res
->lockname
.len
, res
->lockname
.name
, res
->inflight_locks
,
683 __builtin_return_address(0));
688 void __dlm_lockres_grab_inflight_worker(struct dlm_ctxt
*dlm
,
689 struct dlm_lock_resource
*res
)
691 assert_spin_locked(&res
->spinlock
);
692 res
->inflight_assert_workers
++;
693 mlog(0, "%s:%.*s: inflight assert worker++: now %u\n",
694 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
,
695 res
->inflight_assert_workers
);
698 static void __dlm_lockres_drop_inflight_worker(struct dlm_ctxt
*dlm
,
699 struct dlm_lock_resource
*res
)
701 assert_spin_locked(&res
->spinlock
);
702 BUG_ON(res
->inflight_assert_workers
== 0);
703 res
->inflight_assert_workers
--;
704 mlog(0, "%s:%.*s: inflight assert worker--: now %u\n",
705 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
,
706 res
->inflight_assert_workers
);
709 static void dlm_lockres_drop_inflight_worker(struct dlm_ctxt
*dlm
,
710 struct dlm_lock_resource
*res
)
712 spin_lock(&res
->spinlock
);
713 __dlm_lockres_drop_inflight_worker(dlm
, res
);
714 spin_unlock(&res
->spinlock
);
718 * lookup a lock resource by name.
719 * may already exist in the hashtable.
720 * lockid is null terminated
722 * if not, allocate enough for the lockres and for
723 * the temporary structure used in doing the mastering.
725 * also, do a lookup in the dlm->master_list to see
726 * if another node has begun mastering the same lock.
727 * if so, there should be a block entry in there
728 * for this name, and we should *not* attempt to master
729 * the lock here. need to wait around for that node
730 * to assert_master (or die).
733 struct dlm_lock_resource
* dlm_get_lock_resource(struct dlm_ctxt
*dlm
,
738 struct dlm_lock_resource
*tmpres
=NULL
, *res
=NULL
;
739 struct dlm_master_list_entry
*mle
= NULL
;
740 struct dlm_master_list_entry
*alloc_mle
= NULL
;
743 struct dlm_node_iter iter
;
746 int bit
, wait_on_recovery
= 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 spin_unlock(&dlm
->spinlock
);
759 spin_lock(&tmpres
->spinlock
);
762 * Right after dlm spinlock was released, dlm_thread could have
763 * purged the lockres. Check if lockres got unhashed. If so
766 if (hlist_unhashed(&tmpres
->hash_node
)) {
767 spin_unlock(&tmpres
->spinlock
);
768 dlm_lockres_put(tmpres
);
773 /* Wait on the thread that is mastering the resource */
774 if (tmpres
->owner
== DLM_LOCK_RES_OWNER_UNKNOWN
) {
775 __dlm_wait_on_lockres(tmpres
);
776 BUG_ON(tmpres
->owner
== DLM_LOCK_RES_OWNER_UNKNOWN
);
777 spin_unlock(&tmpres
->spinlock
);
778 dlm_lockres_put(tmpres
);
783 /* Wait on the resource purge to complete before continuing */
784 if (tmpres
->state
& DLM_LOCK_RES_DROPPING_REF
) {
785 BUG_ON(tmpres
->owner
== dlm
->node_num
);
786 __dlm_wait_on_lockres_flags(tmpres
,
787 DLM_LOCK_RES_DROPPING_REF
);
788 spin_unlock(&tmpres
->spinlock
);
789 dlm_lockres_put(tmpres
);
794 /* Grab inflight ref to pin the resource */
795 dlm_lockres_grab_inflight_ref(dlm
, tmpres
);
797 spin_unlock(&tmpres
->spinlock
);
799 dlm_lockres_put(res
);
805 spin_unlock(&dlm
->spinlock
);
806 mlog(0, "allocating a new resource\n");
807 /* nothing found and we need to allocate one. */
808 alloc_mle
= kmem_cache_alloc(dlm_mle_cache
, GFP_NOFS
);
811 res
= dlm_new_lockres(dlm
, lockid
, namelen
);
817 mlog(0, "no lockres found, allocated our own: %p\n", res
);
819 if (flags
& LKM_LOCAL
) {
820 /* caller knows it's safe to assume it's not mastered elsewhere
821 * DONE! return right away */
822 spin_lock(&res
->spinlock
);
823 dlm_change_lockres_owner(dlm
, res
, dlm
->node_num
);
824 __dlm_insert_lockres(dlm
, res
);
825 dlm_lockres_grab_inflight_ref(dlm
, res
);
826 spin_unlock(&res
->spinlock
);
827 spin_unlock(&dlm
->spinlock
);
828 /* lockres still marked IN_PROGRESS */
832 /* check master list to see if another node has started mastering it */
833 spin_lock(&dlm
->master_lock
);
835 /* if we found a block, wait for lock to be mastered by another node */
836 blocked
= dlm_find_mle(dlm
, &mle
, (char *)lockid
, namelen
);
839 if (mle
->type
== DLM_MLE_MASTER
) {
840 mlog(ML_ERROR
, "master entry for nonexistent lock!\n");
843 mig
= (mle
->type
== DLM_MLE_MIGRATION
);
844 /* if there is a migration in progress, let the migration
845 * finish before continuing. we can wait for the absence
846 * of the MIGRATION mle: either the migrate finished or
847 * one of the nodes died and the mle was cleaned up.
848 * if there is a BLOCK here, but it already has a master
849 * set, we are too late. the master does not have a ref
850 * for us in the refmap. detach the mle and drop it.
851 * either way, go back to the top and start over. */
852 if (mig
|| mle
->master
!= O2NM_MAX_NODES
) {
853 BUG_ON(mig
&& mle
->master
== dlm
->node_num
);
854 /* we arrived too late. the master does not
855 * have a ref for us. retry. */
856 mlog(0, "%s:%.*s: late on %s\n",
857 dlm
->name
, namelen
, lockid
,
858 mig
? "MIGRATION" : "BLOCK");
859 spin_unlock(&dlm
->master_lock
);
860 spin_unlock(&dlm
->spinlock
);
862 /* master is known, detach */
864 dlm_mle_detach_hb_events(dlm
, mle
);
867 /* this is lame, but we can't wait on either
868 * the mle or lockres waitqueue here */
874 /* go ahead and try to master lock on this node */
876 /* make sure this does not get freed below */
878 dlm_init_mle(mle
, DLM_MLE_MASTER
, dlm
, res
, NULL
, 0);
879 set_bit(dlm
->node_num
, mle
->maybe_map
);
880 __dlm_insert_mle(dlm
, mle
);
882 /* still holding the dlm spinlock, check the recovery map
883 * to see if there are any nodes that still need to be
884 * considered. these will not appear in the mle nodemap
885 * but they might own this lockres. wait on them. */
886 bit
= find_next_bit(dlm
->recovery_map
, O2NM_MAX_NODES
, 0);
887 if (bit
< O2NM_MAX_NODES
) {
888 mlog(0, "%s: res %.*s, At least one node (%d) "
889 "to recover before lock mastery can begin\n",
890 dlm
->name
, namelen
, (char *)lockid
, bit
);
891 wait_on_recovery
= 1;
895 /* at this point there is either a DLM_MLE_BLOCK or a
896 * DLM_MLE_MASTER on the master list, so it's safe to add the
897 * lockres to the hashtable. anyone who finds the lock will
898 * still have to wait on the IN_PROGRESS. */
900 /* finally add the lockres to its hash bucket */
901 __dlm_insert_lockres(dlm
, res
);
903 /* since this lockres is new it doesn't not require the spinlock */
904 __dlm_lockres_grab_inflight_ref(dlm
, res
);
906 /* get an extra ref on the mle in case this is a BLOCK
907 * if so, the creator of the BLOCK may try to put the last
908 * ref at this time in the assert master handler, so we
909 * need an extra one to keep from a bad ptr deref. */
910 dlm_get_mle_inuse(mle
);
911 spin_unlock(&dlm
->master_lock
);
912 spin_unlock(&dlm
->spinlock
);
915 while (wait_on_recovery
) {
916 /* any cluster changes that occurred after dropping the
917 * dlm spinlock would be detectable be a change on the mle,
918 * so we only need to clear out the recovery map once. */
919 if (dlm_is_recovery_lock(lockid
, namelen
)) {
920 mlog(0, "%s: Recovery map is not empty, but must "
921 "master $RECOVERY lock now\n", dlm
->name
);
922 if (!dlm_pre_master_reco_lockres(dlm
, res
))
923 wait_on_recovery
= 0;
925 mlog(0, "%s: waiting 500ms for heartbeat state "
926 "change\n", dlm
->name
);
932 dlm_kick_recovery_thread(dlm
);
934 dlm_wait_for_recovery(dlm
);
936 spin_lock(&dlm
->spinlock
);
937 bit
= find_next_bit(dlm
->recovery_map
, O2NM_MAX_NODES
, 0);
938 if (bit
< O2NM_MAX_NODES
) {
939 mlog(0, "%s: res %.*s, At least one node (%d) "
940 "to recover before lock mastery can begin\n",
941 dlm
->name
, namelen
, (char *)lockid
, bit
);
942 wait_on_recovery
= 1;
944 wait_on_recovery
= 0;
945 spin_unlock(&dlm
->spinlock
);
947 if (wait_on_recovery
)
948 dlm_wait_for_node_recovery(dlm
, bit
, 10000);
951 /* must wait for lock to be mastered elsewhere */
956 dlm_node_iter_init(mle
->vote_map
, &iter
);
957 while ((nodenum
= dlm_node_iter_next(&iter
)) >= 0) {
958 ret
= dlm_do_master_request(res
, mle
, nodenum
);
961 if (mle
->master
!= O2NM_MAX_NODES
) {
962 /* found a master ! */
963 if (mle
->master
<= nodenum
)
965 /* if our master request has not reached the master
966 * yet, keep going until it does. this is how the
967 * master will know that asserts are needed back to
968 * the lower nodes. */
969 mlog(0, "%s: res %.*s, Requests only up to %u but "
970 "master is %u, keep going\n", dlm
->name
, namelen
,
971 lockid
, nodenum
, mle
->master
);
976 /* keep going until the response map includes all nodes */
977 ret
= dlm_wait_for_lock_mastery(dlm
, res
, mle
, &blocked
);
979 wait_on_recovery
= 1;
980 mlog(0, "%s: res %.*s, Node map changed, redo the master "
981 "request now, blocked=%d\n", dlm
->name
, res
->lockname
.len
,
982 res
->lockname
.name
, blocked
);
984 mlog(ML_ERROR
, "%s: res %.*s, Spinning on "
985 "dlm_wait_for_lock_mastery, blocked = %d\n",
986 dlm
->name
, res
->lockname
.len
,
987 res
->lockname
.name
, blocked
);
988 dlm_print_one_lock_resource(res
);
989 dlm_print_one_mle(mle
);
995 mlog(0, "%s: res %.*s, Mastered by %u\n", dlm
->name
, res
->lockname
.len
,
996 res
->lockname
.name
, res
->owner
);
997 /* make sure we never continue without this */
998 BUG_ON(res
->owner
== O2NM_MAX_NODES
);
1000 /* master is known, detach if not already detached */
1001 dlm_mle_detach_hb_events(dlm
, mle
);
1003 /* put the extra ref */
1004 dlm_put_mle_inuse(mle
);
1007 spin_lock(&res
->spinlock
);
1008 res
->state
&= ~DLM_LOCK_RES_IN_PROGRESS
;
1009 spin_unlock(&res
->spinlock
);
1013 /* need to free the unused mle */
1015 kmem_cache_free(dlm_mle_cache
, alloc_mle
);
1021 #define DLM_MASTERY_TIMEOUT_MS 5000
1023 static int dlm_wait_for_lock_mastery(struct dlm_ctxt
*dlm
,
1024 struct dlm_lock_resource
*res
,
1025 struct dlm_master_list_entry
*mle
,
1030 int map_changed
, voting_done
;
1037 /* check if another node has already become the owner */
1038 spin_lock(&res
->spinlock
);
1039 if (res
->owner
!= DLM_LOCK_RES_OWNER_UNKNOWN
) {
1040 mlog(0, "%s:%.*s: owner is suddenly %u\n", dlm
->name
,
1041 res
->lockname
.len
, res
->lockname
.name
, res
->owner
);
1042 spin_unlock(&res
->spinlock
);
1043 /* this will cause the master to re-assert across
1044 * the whole cluster, freeing up mles */
1045 if (res
->owner
!= dlm
->node_num
) {
1046 ret
= dlm_do_master_request(res
, mle
, res
->owner
);
1048 /* give recovery a chance to run */
1049 mlog(ML_ERROR
, "link to %u went down?: %d\n", res
->owner
, ret
);
1057 spin_unlock(&res
->spinlock
);
1059 spin_lock(&mle
->spinlock
);
1061 map_changed
= (memcmp(mle
->vote_map
, mle
->node_map
,
1062 sizeof(mle
->vote_map
)) != 0);
1063 voting_done
= (memcmp(mle
->vote_map
, mle
->response_map
,
1064 sizeof(mle
->vote_map
)) == 0);
1066 /* restart if we hit any errors */
1069 mlog(0, "%s: %.*s: node map changed, restarting\n",
1070 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
);
1071 ret
= dlm_restart_lock_mastery(dlm
, res
, mle
, *blocked
);
1072 b
= (mle
->type
== DLM_MLE_BLOCK
);
1073 if ((*blocked
&& !b
) || (!*blocked
&& b
)) {
1074 mlog(0, "%s:%.*s: status change: old=%d new=%d\n",
1075 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
,
1079 spin_unlock(&mle
->spinlock
);
1084 mlog(0, "%s:%.*s: restart lock mastery succeeded, "
1085 "rechecking now\n", dlm
->name
, res
->lockname
.len
,
1086 res
->lockname
.name
);
1090 mlog(0, "map not changed and voting not done "
1091 "for %s:%.*s\n", dlm
->name
, res
->lockname
.len
,
1092 res
->lockname
.name
);
1096 if (m
!= O2NM_MAX_NODES
) {
1097 /* another node has done an assert!
1102 /* have all nodes responded? */
1103 if (voting_done
&& !*blocked
) {
1104 bit
= find_next_bit(mle
->maybe_map
, O2NM_MAX_NODES
, 0);
1105 if (dlm
->node_num
<= bit
) {
1106 /* my node number is lowest.
1107 * now tell other nodes that I am
1108 * mastering this. */
1109 mle
->master
= dlm
->node_num
;
1110 /* ref was grabbed in get_lock_resource
1111 * will be dropped in dlmlock_master */
1115 /* if voting is done, but we have not received
1116 * an assert master yet, we must sleep */
1120 spin_unlock(&mle
->spinlock
);
1122 /* sleep if we haven't finished voting yet */
1124 unsigned long timeo
= msecs_to_jiffies(DLM_MASTERY_TIMEOUT_MS
);
1127 if (atomic_read(&mle->mle_refs.refcount) < 2)
1128 mlog(ML_ERROR, "mle (%p) refs=%d, name=%.*s\n", mle,
1129 atomic_read(&mle->mle_refs.refcount),
1130 res->lockname.len, res->lockname.name);
1132 atomic_set(&mle
->woken
, 0);
1133 (void)wait_event_timeout(mle
->wq
,
1134 (atomic_read(&mle
->woken
) == 1),
1136 if (res
->owner
== O2NM_MAX_NODES
) {
1137 mlog(0, "%s:%.*s: waiting again\n", dlm
->name
,
1138 res
->lockname
.len
, res
->lockname
.name
);
1141 mlog(0, "done waiting, master is %u\n", res
->owner
);
1149 mlog(0, "about to master %.*s here, this=%u\n",
1150 res
->lockname
.len
, res
->lockname
.name
, m
);
1151 ret
= dlm_do_assert_master(dlm
, res
, mle
->vote_map
, 0);
1153 /* This is a failure in the network path,
1154 * not in the response to the assert_master
1155 * (any nonzero response is a BUG on this node).
1156 * Most likely a socket just got disconnected
1157 * due to node death. */
1160 /* no longer need to restart lock mastery.
1161 * all living nodes have been contacted. */
1165 /* set the lockres owner */
1166 spin_lock(&res
->spinlock
);
1167 /* mastery reference obtained either during
1168 * assert_master_handler or in get_lock_resource */
1169 dlm_change_lockres_owner(dlm
, res
, m
);
1170 spin_unlock(&res
->spinlock
);
1176 struct dlm_bitmap_diff_iter
1179 unsigned long *orig_bm
;
1180 unsigned long *cur_bm
;
1181 unsigned long diff_bm
[BITS_TO_LONGS(O2NM_MAX_NODES
)];
1184 enum dlm_node_state_change
1191 static void dlm_bitmap_diff_iter_init(struct dlm_bitmap_diff_iter
*iter
,
1192 unsigned long *orig_bm
,
1193 unsigned long *cur_bm
)
1195 unsigned long p1
, p2
;
1199 iter
->orig_bm
= orig_bm
;
1200 iter
->cur_bm
= cur_bm
;
1202 for (i
= 0; i
< BITS_TO_LONGS(O2NM_MAX_NODES
); i
++) {
1203 p1
= *(iter
->orig_bm
+ i
);
1204 p2
= *(iter
->cur_bm
+ i
);
1205 iter
->diff_bm
[i
] = (p1
& ~p2
) | (p2
& ~p1
);
1209 static int dlm_bitmap_diff_iter_next(struct dlm_bitmap_diff_iter
*iter
,
1210 enum dlm_node_state_change
*state
)
1214 if (iter
->curnode
>= O2NM_MAX_NODES
)
1217 bit
= find_next_bit(iter
->diff_bm
, O2NM_MAX_NODES
,
1219 if (bit
>= O2NM_MAX_NODES
) {
1220 iter
->curnode
= O2NM_MAX_NODES
;
1224 /* if it was there in the original then this node died */
1225 if (test_bit(bit
, iter
->orig_bm
))
1230 iter
->curnode
= bit
;
1235 static int dlm_restart_lock_mastery(struct dlm_ctxt
*dlm
,
1236 struct dlm_lock_resource
*res
,
1237 struct dlm_master_list_entry
*mle
,
1240 struct dlm_bitmap_diff_iter bdi
;
1241 enum dlm_node_state_change sc
;
1245 mlog(0, "something happened such that the "
1246 "master process may need to be restarted!\n");
1248 assert_spin_locked(&mle
->spinlock
);
1250 dlm_bitmap_diff_iter_init(&bdi
, mle
->vote_map
, mle
->node_map
);
1251 node
= dlm_bitmap_diff_iter_next(&bdi
, &sc
);
1253 if (sc
== NODE_UP
) {
1254 /* a node came up. clear any old vote from
1255 * the response map and set it in the vote map
1256 * then restart the mastery. */
1257 mlog(ML_NOTICE
, "node %d up while restarting\n", node
);
1259 /* redo the master request, but only for the new node */
1260 mlog(0, "sending request to new node\n");
1261 clear_bit(node
, mle
->response_map
);
1262 set_bit(node
, mle
->vote_map
);
1264 mlog(ML_ERROR
, "node down! %d\n", node
);
1266 int lowest
= find_next_bit(mle
->maybe_map
,
1269 /* act like it was never there */
1270 clear_bit(node
, mle
->maybe_map
);
1272 if (node
== lowest
) {
1273 mlog(0, "expected master %u died"
1274 " while this node was blocked "
1275 "waiting on it!\n", node
);
1276 lowest
= find_next_bit(mle
->maybe_map
,
1279 if (lowest
< O2NM_MAX_NODES
) {
1280 mlog(0, "%s:%.*s:still "
1281 "blocked. waiting on %u "
1287 /* mle is an MLE_BLOCK, but
1288 * there is now nothing left to
1289 * block on. we need to return
1290 * all the way back out and try
1291 * again with an MLE_MASTER.
1292 * dlm_do_local_recovery_cleanup
1293 * has already run, so the mle
1295 mlog(0, "%s:%.*s: no "
1296 "longer blocking. try to "
1297 "master this here\n",
1300 res
->lockname
.name
);
1301 mle
->type
= DLM_MLE_MASTER
;
1307 /* now blank out everything, as if we had never
1308 * contacted anyone */
1309 memset(mle
->maybe_map
, 0, sizeof(mle
->maybe_map
));
1310 memset(mle
->response_map
, 0, sizeof(mle
->response_map
));
1311 /* reset the vote_map to the current node_map */
1312 memcpy(mle
->vote_map
, mle
->node_map
,
1313 sizeof(mle
->node_map
));
1314 /* put myself into the maybe map */
1315 if (mle
->type
!= DLM_MLE_BLOCK
)
1316 set_bit(dlm
->node_num
, mle
->maybe_map
);
1319 node
= dlm_bitmap_diff_iter_next(&bdi
, &sc
);
1326 * DLM_MASTER_REQUEST_MSG
1328 * returns: 0 on success,
1329 * -errno on a network error
1331 * on error, the caller should assume the target node is "dead"
1335 static int dlm_do_master_request(struct dlm_lock_resource
*res
,
1336 struct dlm_master_list_entry
*mle
, int to
)
1338 struct dlm_ctxt
*dlm
= mle
->dlm
;
1339 struct dlm_master_request request
;
1340 int ret
, response
=0, resend
;
1342 memset(&request
, 0, sizeof(request
));
1343 request
.node_idx
= dlm
->node_num
;
1345 BUG_ON(mle
->type
== DLM_MLE_MIGRATION
);
1347 request
.namelen
= (u8
)mle
->mnamelen
;
1348 memcpy(request
.name
, mle
->mname
, request
.namelen
);
1351 ret
= o2net_send_message(DLM_MASTER_REQUEST_MSG
, dlm
->key
, &request
,
1352 sizeof(request
), to
, &response
);
1354 if (ret
== -ESRCH
) {
1355 /* should never happen */
1356 mlog(ML_ERROR
, "TCP stack not ready!\n");
1358 } else if (ret
== -EINVAL
) {
1359 mlog(ML_ERROR
, "bad args passed to o2net!\n");
1361 } else if (ret
== -ENOMEM
) {
1362 mlog(ML_ERROR
, "out of memory while trying to send "
1363 "network message! retrying\n");
1364 /* this is totally crude */
1367 } else if (!dlm_is_host_down(ret
)) {
1368 /* not a network error. bad. */
1370 mlog(ML_ERROR
, "unhandled error!");
1373 /* all other errors should be network errors,
1374 * and likely indicate node death */
1375 mlog(ML_ERROR
, "link to %d went down!\n", to
);
1381 spin_lock(&mle
->spinlock
);
1383 case DLM_MASTER_RESP_YES
:
1384 set_bit(to
, mle
->response_map
);
1385 mlog(0, "node %u is the master, response=YES\n", to
);
1386 mlog(0, "%s:%.*s: master node %u now knows I have a "
1387 "reference\n", dlm
->name
, res
->lockname
.len
,
1388 res
->lockname
.name
, to
);
1391 case DLM_MASTER_RESP_NO
:
1392 mlog(0, "node %u not master, response=NO\n", to
);
1393 set_bit(to
, mle
->response_map
);
1395 case DLM_MASTER_RESP_MAYBE
:
1396 mlog(0, "node %u not master, response=MAYBE\n", to
);
1397 set_bit(to
, mle
->response_map
);
1398 set_bit(to
, mle
->maybe_map
);
1400 case DLM_MASTER_RESP_ERROR
:
1401 mlog(0, "node %u hit an error, resending\n", to
);
1406 mlog(ML_ERROR
, "bad response! %u\n", response
);
1409 spin_unlock(&mle
->spinlock
);
1411 /* this is also totally crude */
1421 * locks that can be taken here:
1427 * if possible, TRIM THIS DOWN!!!
1429 int dlm_master_request_handler(struct o2net_msg
*msg
, u32 len
, void *data
,
1432 u8 response
= DLM_MASTER_RESP_MAYBE
;
1433 struct dlm_ctxt
*dlm
= data
;
1434 struct dlm_lock_resource
*res
= NULL
;
1435 struct dlm_master_request
*request
= (struct dlm_master_request
*) msg
->buf
;
1436 struct dlm_master_list_entry
*mle
= NULL
, *tmpmle
= NULL
;
1438 unsigned int namelen
, hash
;
1441 int dispatch_assert
= 0;
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
);
1470 * Right after dlm spinlock was released, dlm_thread could have
1471 * purged the lockres. Check if lockres got unhashed. If so
1474 if (hlist_unhashed(&res
->hash_node
)) {
1475 spin_unlock(&res
->spinlock
);
1476 dlm_lockres_put(res
);
1480 if (res
->state
& (DLM_LOCK_RES_RECOVERING
|
1481 DLM_LOCK_RES_MIGRATING
)) {
1482 spin_unlock(&res
->spinlock
);
1483 mlog(0, "returning DLM_MASTER_RESP_ERROR since res is "
1484 "being recovered/migrated\n");
1485 response
= DLM_MASTER_RESP_ERROR
;
1487 kmem_cache_free(dlm_mle_cache
, mle
);
1491 if (res
->owner
== dlm
->node_num
) {
1492 dlm_lockres_set_refmap_bit(dlm
, res
, request
->node_idx
);
1493 spin_unlock(&res
->spinlock
);
1494 response
= DLM_MASTER_RESP_YES
;
1496 kmem_cache_free(dlm_mle_cache
, mle
);
1498 /* this node is the owner.
1499 * there is some extra work that needs to
1500 * happen now. the requesting node has
1501 * caused all nodes up to this one to
1502 * create mles. this node now needs to
1503 * go back and clean those up. */
1504 dispatch_assert
= 1;
1506 } else if (res
->owner
!= DLM_LOCK_RES_OWNER_UNKNOWN
) {
1507 spin_unlock(&res
->spinlock
);
1508 // mlog(0, "node %u is the master\n", res->owner);
1509 response
= DLM_MASTER_RESP_NO
;
1511 kmem_cache_free(dlm_mle_cache
, mle
);
1515 /* ok, there is no owner. either this node is
1516 * being blocked, or it is actively trying to
1517 * master this lock. */
1518 if (!(res
->state
& DLM_LOCK_RES_IN_PROGRESS
)) {
1519 mlog(ML_ERROR
, "lock with no owner should be "
1524 // mlog(0, "lockres is in progress...\n");
1525 spin_lock(&dlm
->master_lock
);
1526 found
= dlm_find_mle(dlm
, &tmpmle
, name
, namelen
);
1528 mlog(ML_ERROR
, "no mle found for this lock!\n");
1532 spin_lock(&tmpmle
->spinlock
);
1533 if (tmpmle
->type
== DLM_MLE_BLOCK
) {
1534 // mlog(0, "this node is waiting for "
1535 // "lockres to be mastered\n");
1536 response
= DLM_MASTER_RESP_NO
;
1537 } else if (tmpmle
->type
== DLM_MLE_MIGRATION
) {
1538 mlog(0, "node %u is master, but trying to migrate to "
1539 "node %u.\n", tmpmle
->master
, tmpmle
->new_master
);
1540 if (tmpmle
->master
== dlm
->node_num
) {
1541 mlog(ML_ERROR
, "no owner on lockres, but this "
1542 "node is trying to migrate it to %u?!\n",
1543 tmpmle
->new_master
);
1546 /* the real master can respond on its own */
1547 response
= DLM_MASTER_RESP_NO
;
1549 } else if (tmpmle
->master
!= DLM_LOCK_RES_OWNER_UNKNOWN
) {
1551 if (tmpmle
->master
== dlm
->node_num
) {
1552 response
= DLM_MASTER_RESP_YES
;
1553 /* this node will be the owner.
1554 * go back and clean the mles on any
1556 dispatch_assert
= 1;
1557 dlm_lockres_set_refmap_bit(dlm
, res
,
1560 response
= DLM_MASTER_RESP_NO
;
1562 // mlog(0, "this node is attempting to "
1563 // "master lockres\n");
1564 response
= DLM_MASTER_RESP_MAYBE
;
1567 set_bit(request
->node_idx
, tmpmle
->maybe_map
);
1568 spin_unlock(&tmpmle
->spinlock
);
1570 spin_unlock(&dlm
->master_lock
);
1571 spin_unlock(&res
->spinlock
);
1573 /* keep the mle attached to heartbeat events */
1574 dlm_put_mle(tmpmle
);
1576 kmem_cache_free(dlm_mle_cache
, mle
);
1581 * lockres doesn't exist on this node
1582 * if there is an MLE_BLOCK, return NO
1583 * if there is an MLE_MASTER, return MAYBE
1584 * otherwise, add an MLE_BLOCK, return NO
1586 spin_lock(&dlm
->master_lock
);
1587 found
= dlm_find_mle(dlm
, &tmpmle
, name
, namelen
);
1589 /* this lockid has never been seen on this node yet */
1590 // mlog(0, "no mle found\n");
1592 spin_unlock(&dlm
->master_lock
);
1593 spin_unlock(&dlm
->spinlock
);
1595 mle
= kmem_cache_alloc(dlm_mle_cache
, GFP_NOFS
);
1597 response
= DLM_MASTER_RESP_ERROR
;
1598 mlog_errno(-ENOMEM
);
1604 // mlog(0, "this is second time thru, already allocated, "
1605 // "add the block.\n");
1606 dlm_init_mle(mle
, DLM_MLE_BLOCK
, dlm
, NULL
, name
, namelen
);
1607 set_bit(request
->node_idx
, mle
->maybe_map
);
1608 __dlm_insert_mle(dlm
, mle
);
1609 response
= DLM_MASTER_RESP_NO
;
1611 // mlog(0, "mle was found\n");
1613 spin_lock(&tmpmle
->spinlock
);
1614 if (tmpmle
->master
== dlm
->node_num
) {
1615 mlog(ML_ERROR
, "no lockres, but an mle with this node as master!\n");
1618 if (tmpmle
->type
== DLM_MLE_BLOCK
)
1619 response
= DLM_MASTER_RESP_NO
;
1620 else if (tmpmle
->type
== DLM_MLE_MIGRATION
) {
1621 mlog(0, "migration mle was found (%u->%u)\n",
1622 tmpmle
->master
, tmpmle
->new_master
);
1623 /* real master can respond on its own */
1624 response
= DLM_MASTER_RESP_NO
;
1626 response
= DLM_MASTER_RESP_MAYBE
;
1628 set_bit(request
->node_idx
, tmpmle
->maybe_map
);
1629 spin_unlock(&tmpmle
->spinlock
);
1631 spin_unlock(&dlm
->master_lock
);
1632 spin_unlock(&dlm
->spinlock
);
1635 /* keep the mle attached to heartbeat events */
1636 dlm_put_mle(tmpmle
);
1640 * __dlm_lookup_lockres() grabbed a reference to this lockres.
1641 * The reference is released by dlm_assert_master_worker() under
1642 * the call to dlm_dispatch_assert_master(). If
1643 * dlm_assert_master_worker() isn't called, we drop it here.
1645 if (dispatch_assert
) {
1646 if (response
!= DLM_MASTER_RESP_YES
)
1647 mlog(ML_ERROR
, "invalid response %d\n", response
);
1649 mlog(ML_ERROR
, "bad lockres while trying to assert!\n");
1652 mlog(0, "%u is the owner of %.*s, cleaning everyone else\n",
1653 dlm
->node_num
, res
->lockname
.len
, res
->lockname
.name
);
1654 spin_lock(&res
->spinlock
);
1655 ret
= dlm_dispatch_assert_master(dlm
, res
, 0, request
->node_idx
,
1656 DLM_ASSERT_MASTER_MLE_CLEANUP
);
1658 mlog(ML_ERROR
, "failed to dispatch assert master work\n");
1659 response
= DLM_MASTER_RESP_ERROR
;
1660 dlm_lockres_put(res
);
1662 __dlm_lockres_grab_inflight_worker(dlm
, res
);
1663 spin_unlock(&res
->spinlock
);
1666 dlm_lockres_put(res
);
1674 * DLM_ASSERT_MASTER_MSG
1679 * NOTE: this can be used for debugging
1680 * can periodically run all locks owned by this node
1681 * and re-assert across the cluster...
1683 static int dlm_do_assert_master(struct dlm_ctxt
*dlm
,
1684 struct dlm_lock_resource
*res
,
1685 void *nodemap
, u32 flags
)
1687 struct dlm_assert_master
assert;
1689 struct dlm_node_iter iter
;
1692 const char *lockname
= res
->lockname
.name
;
1693 unsigned int namelen
= res
->lockname
.len
;
1695 BUG_ON(namelen
> O2NM_MAX_NAME_LEN
);
1697 spin_lock(&res
->spinlock
);
1698 res
->state
|= DLM_LOCK_RES_SETREF_INPROG
;
1699 spin_unlock(&res
->spinlock
);
1704 /* note that if this nodemap is empty, it returns 0 */
1705 dlm_node_iter_init(nodemap
, &iter
);
1706 while ((to
= dlm_node_iter_next(&iter
)) >= 0) {
1708 struct dlm_master_list_entry
*mle
= NULL
;
1710 mlog(0, "sending assert master to %d (%.*s)\n", to
,
1712 memset(&assert, 0, sizeof(assert));
1713 assert.node_idx
= dlm
->node_num
;
1714 assert.namelen
= namelen
;
1715 memcpy(assert.name
, lockname
, namelen
);
1716 assert.flags
= cpu_to_be32(flags
);
1718 tmpret
= o2net_send_message(DLM_ASSERT_MASTER_MSG
, dlm
->key
,
1719 &assert, sizeof(assert), to
, &r
);
1721 mlog(ML_ERROR
, "Error %d when sending message %u (key "
1722 "0x%x) to node %u\n", tmpret
,
1723 DLM_ASSERT_MASTER_MSG
, dlm
->key
, to
);
1724 if (!dlm_is_host_down(tmpret
)) {
1725 mlog(ML_ERROR
, "unhandled error=%d!\n", tmpret
);
1728 /* a node died. finish out the rest of the nodes. */
1729 mlog(0, "link to %d went down!\n", to
);
1730 /* any nonzero status return will do */
1734 /* ok, something horribly messed. kill thyself. */
1735 mlog(ML_ERROR
,"during assert master of %.*s to %u, "
1736 "got %d.\n", namelen
, lockname
, to
, r
);
1737 spin_lock(&dlm
->spinlock
);
1738 spin_lock(&dlm
->master_lock
);
1739 if (dlm_find_mle(dlm
, &mle
, (char *)lockname
,
1741 dlm_print_one_mle(mle
);
1744 spin_unlock(&dlm
->master_lock
);
1745 spin_unlock(&dlm
->spinlock
);
1749 if (r
& DLM_ASSERT_RESPONSE_REASSERT
&&
1750 !(r
& DLM_ASSERT_RESPONSE_MASTERY_REF
)) {
1751 mlog(ML_ERROR
, "%.*s: very strange, "
1752 "master MLE but no lockres on %u\n",
1753 namelen
, lockname
, to
);
1756 if (r
& DLM_ASSERT_RESPONSE_REASSERT
) {
1757 mlog(0, "%.*s: node %u create mles on other "
1758 "nodes and requests a re-assert\n",
1759 namelen
, lockname
, to
);
1762 if (r
& DLM_ASSERT_RESPONSE_MASTERY_REF
) {
1763 mlog(0, "%.*s: node %u has a reference to this "
1764 "lockres, set the bit in the refmap\n",
1765 namelen
, lockname
, to
);
1766 spin_lock(&res
->spinlock
);
1767 dlm_lockres_set_refmap_bit(dlm
, res
, to
);
1768 spin_unlock(&res
->spinlock
);
1775 spin_lock(&res
->spinlock
);
1776 res
->state
&= ~DLM_LOCK_RES_SETREF_INPROG
;
1777 spin_unlock(&res
->spinlock
);
1784 * locks that can be taken here:
1790 * if possible, TRIM THIS DOWN!!!
1792 int dlm_assert_master_handler(struct o2net_msg
*msg
, u32 len
, void *data
,
1795 struct dlm_ctxt
*dlm
= data
;
1796 struct dlm_master_list_entry
*mle
= NULL
;
1797 struct dlm_assert_master
*assert = (struct dlm_assert_master
*)msg
->buf
;
1798 struct dlm_lock_resource
*res
= NULL
;
1800 unsigned int namelen
, hash
;
1802 int master_request
= 0, have_lockres_ref
= 0;
1808 name
= assert->name
;
1809 namelen
= assert->namelen
;
1810 hash
= dlm_lockid_hash(name
, namelen
);
1811 flags
= be32_to_cpu(assert->flags
);
1813 if (namelen
> DLM_LOCKID_NAME_MAX
) {
1814 mlog(ML_ERROR
, "Invalid name length!");
1818 spin_lock(&dlm
->spinlock
);
1821 mlog(0, "assert_master with flags: %u\n", flags
);
1824 spin_lock(&dlm
->master_lock
);
1825 if (!dlm_find_mle(dlm
, &mle
, name
, namelen
)) {
1826 /* not an error, could be master just re-asserting */
1827 mlog(0, "just got an assert_master from %u, but no "
1828 "MLE for it! (%.*s)\n", assert->node_idx
,
1831 int bit
= find_next_bit (mle
->maybe_map
, O2NM_MAX_NODES
, 0);
1832 if (bit
>= O2NM_MAX_NODES
) {
1833 /* not necessarily an error, though less likely.
1834 * could be master just re-asserting. */
1835 mlog(0, "no bits set in the maybe_map, but %u "
1836 "is asserting! (%.*s)\n", assert->node_idx
,
1838 } else if (bit
!= assert->node_idx
) {
1839 if (flags
& DLM_ASSERT_MASTER_MLE_CLEANUP
) {
1840 mlog(0, "master %u was found, %u should "
1841 "back off\n", assert->node_idx
, bit
);
1843 /* with the fix for bug 569, a higher node
1844 * number winning the mastery will respond
1845 * YES to mastery requests, but this node
1846 * had no way of knowing. let it pass. */
1847 mlog(0, "%u is the lowest node, "
1848 "%u is asserting. (%.*s) %u must "
1849 "have begun after %u won.\n", bit
,
1850 assert->node_idx
, namelen
, name
, bit
,
1854 if (mle
->type
== DLM_MLE_MIGRATION
) {
1855 if (flags
& DLM_ASSERT_MASTER_MLE_CLEANUP
) {
1856 mlog(0, "%s:%.*s: got cleanup assert"
1857 " from %u for migration\n",
1858 dlm
->name
, namelen
, name
,
1860 } else if (!(flags
& DLM_ASSERT_MASTER_FINISH_MIGRATION
)) {
1861 mlog(0, "%s:%.*s: got unrelated assert"
1862 " from %u for migration, ignoring\n",
1863 dlm
->name
, namelen
, name
,
1866 spin_unlock(&dlm
->master_lock
);
1867 spin_unlock(&dlm
->spinlock
);
1872 spin_unlock(&dlm
->master_lock
);
1874 /* ok everything checks out with the MLE
1875 * now check to see if there is a lockres */
1876 res
= __dlm_lookup_lockres(dlm
, name
, namelen
, hash
);
1878 spin_lock(&res
->spinlock
);
1879 if (res
->state
& DLM_LOCK_RES_RECOVERING
) {
1880 mlog(ML_ERROR
, "%u asserting but %.*s is "
1881 "RECOVERING!\n", assert->node_idx
, namelen
, name
);
1885 if (res
->owner
!= DLM_LOCK_RES_OWNER_UNKNOWN
&&
1886 res
->owner
!= assert->node_idx
) {
1887 mlog(ML_ERROR
, "DIE! Mastery assert from %u, "
1888 "but current owner is %u! (%.*s)\n",
1889 assert->node_idx
, res
->owner
, namelen
,
1891 __dlm_print_one_lock_resource(res
);
1894 } else if (mle
->type
!= DLM_MLE_MIGRATION
) {
1895 if (res
->owner
!= DLM_LOCK_RES_OWNER_UNKNOWN
) {
1896 /* owner is just re-asserting */
1897 if (res
->owner
== assert->node_idx
) {
1898 mlog(0, "owner %u re-asserting on "
1899 "lock %.*s\n", assert->node_idx
,
1903 mlog(ML_ERROR
, "got assert_master from "
1904 "node %u, but %u is the owner! "
1905 "(%.*s)\n", assert->node_idx
,
1906 res
->owner
, namelen
, name
);
1909 if (!(res
->state
& DLM_LOCK_RES_IN_PROGRESS
)) {
1910 mlog(ML_ERROR
, "got assert from %u, but lock "
1911 "with no owner should be "
1912 "in-progress! (%.*s)\n",
1917 } else /* mle->type == DLM_MLE_MIGRATION */ {
1918 /* should only be getting an assert from new master */
1919 if (assert->node_idx
!= mle
->new_master
) {
1920 mlog(ML_ERROR
, "got assert from %u, but "
1921 "new master is %u, and old master "
1923 assert->node_idx
, mle
->new_master
,
1924 mle
->master
, namelen
, name
);
1930 spin_unlock(&res
->spinlock
);
1933 // mlog(0, "woo! got an assert_master from node %u!\n",
1934 // assert->node_idx);
1940 spin_lock(&mle
->spinlock
);
1941 if (mle
->type
== DLM_MLE_BLOCK
|| mle
->type
== DLM_MLE_MIGRATION
)
1944 /* MASTER mle: if any bits set in the response map
1945 * then the calling node needs to re-assert to clear
1946 * up nodes that this node contacted */
1947 while ((nn
= find_next_bit (mle
->response_map
, O2NM_MAX_NODES
,
1948 nn
+1)) < O2NM_MAX_NODES
) {
1949 if (nn
!= dlm
->node_num
&& nn
!= assert->node_idx
) {
1955 mle
->master
= assert->node_idx
;
1956 atomic_set(&mle
->woken
, 1);
1958 spin_unlock(&mle
->spinlock
);
1962 spin_lock(&res
->spinlock
);
1963 if (mle
->type
== DLM_MLE_MIGRATION
) {
1964 mlog(0, "finishing off migration of lockres %.*s, "
1966 res
->lockname
.len
, res
->lockname
.name
,
1967 dlm
->node_num
, mle
->new_master
);
1968 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
1970 dlm_change_lockres_owner(dlm
, res
, mle
->new_master
);
1971 BUG_ON(res
->state
& DLM_LOCK_RES_DIRTY
);
1973 dlm_change_lockres_owner(dlm
, res
, mle
->master
);
1975 spin_unlock(&res
->spinlock
);
1976 have_lockres_ref
= 1;
1981 /* master is known, detach if not already detached.
1982 * ensures that only one assert_master call will happen
1984 spin_lock(&dlm
->master_lock
);
1986 rr
= atomic_read(&mle
->mle_refs
.refcount
);
1987 if (mle
->inuse
> 0) {
1988 if (extra_ref
&& rr
< 3)
1990 else if (!extra_ref
&& rr
< 2)
1993 if (extra_ref
&& rr
< 2)
1995 else if (!extra_ref
&& rr
< 1)
1999 mlog(ML_ERROR
, "%s:%.*s: got assert master from %u "
2000 "that will mess up this node, refs=%d, extra=%d, "
2001 "inuse=%d\n", dlm
->name
, namelen
, name
,
2002 assert->node_idx
, rr
, extra_ref
, mle
->inuse
);
2003 dlm_print_one_mle(mle
);
2005 __dlm_unlink_mle(dlm
, mle
);
2006 __dlm_mle_detach_hb_events(dlm
, mle
);
2009 /* the assert master message now balances the extra
2010 * ref given by the master / migration request message.
2011 * if this is the last put, it will be removed
2015 spin_unlock(&dlm
->master_lock
);
2017 if (res
->owner
!= assert->node_idx
) {
2018 mlog(0, "assert_master from %u, but current "
2019 "owner is %u (%.*s), no mle\n", assert->node_idx
,
2020 res
->owner
, namelen
, name
);
2023 spin_unlock(&dlm
->spinlock
);
2028 spin_lock(&res
->spinlock
);
2029 res
->state
|= DLM_LOCK_RES_SETREF_INPROG
;
2030 spin_unlock(&res
->spinlock
);
2031 *ret_data
= (void *)res
;
2034 if (master_request
) {
2035 mlog(0, "need to tell master to reassert\n");
2036 /* positive. negative would shoot down the node. */
2037 ret
|= DLM_ASSERT_RESPONSE_REASSERT
;
2038 if (!have_lockres_ref
) {
2039 mlog(ML_ERROR
, "strange, got assert from %u, MASTER "
2040 "mle present here for %s:%.*s, but no lockres!\n",
2041 assert->node_idx
, dlm
->name
, namelen
, name
);
2044 if (have_lockres_ref
) {
2045 /* let the master know we have a reference to the lockres */
2046 ret
|= DLM_ASSERT_RESPONSE_MASTERY_REF
;
2047 mlog(0, "%s:%.*s: got assert from %u, need a ref\n",
2048 dlm
->name
, namelen
, name
, assert->node_idx
);
2053 /* kill the caller! */
2054 mlog(ML_ERROR
, "Bad message received from another node. Dumping state "
2055 "and killing the other node now! This node is OK and can continue.\n");
2056 __dlm_print_one_lock_resource(res
);
2057 spin_unlock(&res
->spinlock
);
2058 spin_lock(&dlm
->master_lock
);
2061 spin_unlock(&dlm
->master_lock
);
2062 spin_unlock(&dlm
->spinlock
);
2063 *ret_data
= (void *)res
;
2068 void dlm_assert_master_post_handler(int status
, void *data
, void *ret_data
)
2070 struct dlm_lock_resource
*res
= (struct dlm_lock_resource
*)ret_data
;
2073 spin_lock(&res
->spinlock
);
2074 res
->state
&= ~DLM_LOCK_RES_SETREF_INPROG
;
2075 spin_unlock(&res
->spinlock
);
2077 dlm_lockres_put(res
);
2082 int dlm_dispatch_assert_master(struct dlm_ctxt
*dlm
,
2083 struct dlm_lock_resource
*res
,
2084 int ignore_higher
, u8 request_from
, u32 flags
)
2086 struct dlm_work_item
*item
;
2087 item
= kzalloc(sizeof(*item
), GFP_ATOMIC
);
2092 /* queue up work for dlm_assert_master_worker */
2093 dlm_grab(dlm
); /* get an extra ref for the work item */
2094 dlm_init_work_item(dlm
, item
, dlm_assert_master_worker
, NULL
);
2095 item
->u
.am
.lockres
= res
; /* already have a ref */
2096 /* can optionally ignore node numbers higher than this node */
2097 item
->u
.am
.ignore_higher
= ignore_higher
;
2098 item
->u
.am
.request_from
= request_from
;
2099 item
->u
.am
.flags
= flags
;
2102 mlog(0, "IGNORE HIGHER: %.*s\n", res
->lockname
.len
,
2103 res
->lockname
.name
);
2105 spin_lock(&dlm
->work_lock
);
2106 list_add_tail(&item
->list
, &dlm
->work_list
);
2107 spin_unlock(&dlm
->work_lock
);
2109 queue_work(dlm
->dlm_worker
, &dlm
->dispatched_work
);
2113 static void dlm_assert_master_worker(struct dlm_work_item
*item
, void *data
)
2115 struct dlm_ctxt
*dlm
= data
;
2117 struct dlm_lock_resource
*res
;
2118 unsigned long nodemap
[BITS_TO_LONGS(O2NM_MAX_NODES
)];
2125 res
= item
->u
.am
.lockres
;
2126 ignore_higher
= item
->u
.am
.ignore_higher
;
2127 request_from
= item
->u
.am
.request_from
;
2128 flags
= item
->u
.am
.flags
;
2130 spin_lock(&dlm
->spinlock
);
2131 memcpy(nodemap
, dlm
->domain_map
, sizeof(nodemap
));
2132 spin_unlock(&dlm
->spinlock
);
2134 clear_bit(dlm
->node_num
, nodemap
);
2135 if (ignore_higher
) {
2136 /* if is this just to clear up mles for nodes below
2137 * this node, do not send the message to the original
2138 * caller or any node number higher than this */
2139 clear_bit(request_from
, nodemap
);
2140 bit
= dlm
->node_num
;
2142 bit
= find_next_bit(nodemap
, O2NM_MAX_NODES
,
2144 if (bit
>= O2NM_MAX_NODES
)
2146 clear_bit(bit
, nodemap
);
2151 * If we're migrating this lock to someone else, we are no
2152 * longer allowed to assert out own mastery. OTOH, we need to
2153 * prevent migration from starting while we're still asserting
2154 * our dominance. The reserved ast delays migration.
2156 spin_lock(&res
->spinlock
);
2157 if (res
->state
& DLM_LOCK_RES_MIGRATING
) {
2158 mlog(0, "Someone asked us to assert mastery, but we're "
2159 "in the middle of migration. Skipping assert, "
2160 "the new master will handle that.\n");
2161 spin_unlock(&res
->spinlock
);
2164 __dlm_lockres_reserve_ast(res
);
2165 spin_unlock(&res
->spinlock
);
2167 /* this call now finishes out the nodemap
2168 * even if one or more nodes die */
2169 mlog(0, "worker about to master %.*s here, this=%u\n",
2170 res
->lockname
.len
, res
->lockname
.name
, dlm
->node_num
);
2171 ret
= dlm_do_assert_master(dlm
, res
, nodemap
, flags
);
2173 /* no need to restart, we are done */
2174 if (!dlm_is_host_down(ret
))
2178 /* Ok, we've asserted ourselves. Let's let migration start. */
2179 dlm_lockres_release_ast(dlm
, res
);
2182 dlm_lockres_drop_inflight_worker(dlm
, res
);
2184 dlm_lockres_put(res
);
2186 mlog(0, "finished with dlm_assert_master_worker\n");
2189 /* SPECIAL CASE for the $RECOVERY lock used by the recovery thread.
2190 * We cannot wait for node recovery to complete to begin mastering this
2191 * lockres because this lockres is used to kick off recovery! ;-)
2192 * So, do a pre-check on all living nodes to see if any of those nodes
2193 * think that $RECOVERY is currently mastered by a dead node. If so,
2194 * we wait a short time to allow that node to get notified by its own
2195 * heartbeat stack, then check again. All $RECOVERY lock resources
2196 * mastered by dead nodes are purged when the hearbeat callback is
2197 * fired, so we can know for sure that it is safe to continue once
2198 * the node returns a live node or no node. */
2199 static int dlm_pre_master_reco_lockres(struct dlm_ctxt
*dlm
,
2200 struct dlm_lock_resource
*res
)
2202 struct dlm_node_iter iter
;
2205 u8 master
= DLM_LOCK_RES_OWNER_UNKNOWN
;
2207 spin_lock(&dlm
->spinlock
);
2208 dlm_node_iter_init(dlm
->domain_map
, &iter
);
2209 spin_unlock(&dlm
->spinlock
);
2211 while ((nodenum
= dlm_node_iter_next(&iter
)) >= 0) {
2212 /* do not send to self */
2213 if (nodenum
== dlm
->node_num
)
2215 ret
= dlm_do_master_requery(dlm
, res
, nodenum
, &master
);
2218 if (!dlm_is_host_down(ret
))
2220 /* host is down, so answer for that node would be
2221 * DLM_LOCK_RES_OWNER_UNKNOWN. continue. */
2225 if (master
!= DLM_LOCK_RES_OWNER_UNKNOWN
) {
2226 /* check to see if this master is in the recovery map */
2227 spin_lock(&dlm
->spinlock
);
2228 if (test_bit(master
, dlm
->recovery_map
)) {
2229 mlog(ML_NOTICE
, "%s: node %u has not seen "
2230 "node %u go down yet, and thinks the "
2231 "dead node is mastering the recovery "
2232 "lock. must wait.\n", dlm
->name
,
2236 spin_unlock(&dlm
->spinlock
);
2237 mlog(0, "%s: reco lock master is %u\n", dlm
->name
,
2246 * DLM_DEREF_LOCKRES_MSG
2249 int dlm_drop_lockres_ref(struct dlm_ctxt
*dlm
, struct dlm_lock_resource
*res
)
2251 struct dlm_deref_lockres deref
;
2253 const char *lockname
;
2254 unsigned int namelen
;
2256 lockname
= res
->lockname
.name
;
2257 namelen
= res
->lockname
.len
;
2258 BUG_ON(namelen
> O2NM_MAX_NAME_LEN
);
2260 memset(&deref
, 0, sizeof(deref
));
2261 deref
.node_idx
= dlm
->node_num
;
2262 deref
.namelen
= namelen
;
2263 memcpy(deref
.name
, lockname
, namelen
);
2265 ret
= o2net_send_message(DLM_DEREF_LOCKRES_MSG
, dlm
->key
,
2266 &deref
, sizeof(deref
), res
->owner
, &r
);
2268 mlog(ML_ERROR
, "%s: res %.*s, error %d send DEREF to node %u\n",
2269 dlm
->name
, namelen
, lockname
, ret
, res
->owner
);
2271 /* BAD. other node says I did not have a ref. */
2272 mlog(ML_ERROR
, "%s: res %.*s, DEREF to node %u got %d\n",
2273 dlm
->name
, namelen
, lockname
, res
->owner
, r
);
2274 dlm_print_one_lock_resource(res
);
2280 int dlm_deref_lockres_handler(struct o2net_msg
*msg
, u32 len
, void *data
,
2283 struct dlm_ctxt
*dlm
= data
;
2284 struct dlm_deref_lockres
*deref
= (struct dlm_deref_lockres
*)msg
->buf
;
2285 struct dlm_lock_resource
*res
= NULL
;
2287 unsigned int namelen
;
2291 struct dlm_work_item
*item
;
2299 namelen
= deref
->namelen
;
2300 node
= deref
->node_idx
;
2302 if (namelen
> DLM_LOCKID_NAME_MAX
) {
2303 mlog(ML_ERROR
, "Invalid name length!");
2306 if (deref
->node_idx
>= O2NM_MAX_NODES
) {
2307 mlog(ML_ERROR
, "Invalid node number: %u\n", node
);
2311 hash
= dlm_lockid_hash(name
, namelen
);
2313 spin_lock(&dlm
->spinlock
);
2314 res
= __dlm_lookup_lockres_full(dlm
, name
, namelen
, hash
);
2316 spin_unlock(&dlm
->spinlock
);
2317 mlog(ML_ERROR
, "%s:%.*s: bad lockres name\n",
2318 dlm
->name
, namelen
, name
);
2321 spin_unlock(&dlm
->spinlock
);
2323 spin_lock(&res
->spinlock
);
2324 if (res
->state
& DLM_LOCK_RES_SETREF_INPROG
)
2327 BUG_ON(res
->state
& DLM_LOCK_RES_DROPPING_REF
);
2328 if (test_bit(node
, res
->refmap
)) {
2329 dlm_lockres_clear_refmap_bit(dlm
, res
, node
);
2333 spin_unlock(&res
->spinlock
);
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
);
2348 item
= kzalloc(sizeof(*item
), GFP_NOFS
);
2355 dlm_init_work_item(dlm
, item
, dlm_deref_lockres_worker
, NULL
);
2356 item
->u
.dl
.deref_res
= res
;
2357 item
->u
.dl
.deref_node
= node
;
2359 spin_lock(&dlm
->work_lock
);
2360 list_add_tail(&item
->list
, &dlm
->work_list
);
2361 spin_unlock(&dlm
->work_lock
);
2363 queue_work(dlm
->dlm_worker
, &dlm
->dispatched_work
);
2368 dlm_lockres_put(res
);
2374 static void dlm_deref_lockres_worker(struct dlm_work_item
*item
, void *data
)
2376 struct dlm_ctxt
*dlm
;
2377 struct dlm_lock_resource
*res
;
2382 res
= item
->u
.dl
.deref_res
;
2383 node
= item
->u
.dl
.deref_node
;
2385 spin_lock(&res
->spinlock
);
2386 BUG_ON(res
->state
& DLM_LOCK_RES_DROPPING_REF
);
2387 if (test_bit(node
, res
->refmap
)) {
2388 __dlm_wait_on_lockres_flags(res
, DLM_LOCK_RES_SETREF_INPROG
);
2389 dlm_lockres_clear_refmap_bit(dlm
, res
, node
);
2392 spin_unlock(&res
->spinlock
);
2395 mlog(0, "%s:%.*s node %u ref dropped in dispatch\n",
2396 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
, node
);
2397 dlm_lockres_calc_usage(dlm
, res
);
2399 mlog(ML_ERROR
, "%s:%.*s: node %u trying to drop ref "
2400 "but it is already dropped!\n", dlm
->name
,
2401 res
->lockname
.len
, res
->lockname
.name
, node
);
2402 dlm_print_one_lock_resource(res
);
2405 dlm_lockres_put(res
);
2409 * A migrateable resource is one that is :
2410 * 1. locally mastered, and,
2411 * 2. zero local locks, and,
2412 * 3. one or more non-local locks, or, one or more references
2413 * Returns 1 if yes, 0 if not.
2415 static int dlm_is_lockres_migrateable(struct dlm_ctxt
*dlm
,
2416 struct dlm_lock_resource
*res
)
2418 enum dlm_lockres_list idx
;
2419 int nonlocal
= 0, node_ref
;
2420 struct list_head
*queue
;
2421 struct dlm_lock
*lock
;
2424 assert_spin_locked(&res
->spinlock
);
2426 /* delay migration when the lockres is in MIGRATING state */
2427 if (res
->state
& DLM_LOCK_RES_MIGRATING
)
2430 /* delay migration when the lockres is in RECOCERING state */
2431 if (res
->state
& DLM_LOCK_RES_RECOVERING
)
2434 if (res
->owner
!= dlm
->node_num
)
2437 for (idx
= DLM_GRANTED_LIST
; idx
<= DLM_BLOCKED_LIST
; idx
++) {
2438 queue
= dlm_list_idx_to_ptr(res
, idx
);
2439 list_for_each_entry(lock
, queue
, list
) {
2440 if (lock
->ml
.node
!= dlm
->node_num
) {
2444 cookie
= be64_to_cpu(lock
->ml
.cookie
);
2445 mlog(0, "%s: Not migrateable res %.*s, lock %u:%llu on "
2446 "%s list\n", dlm
->name
, res
->lockname
.len
,
2448 dlm_get_lock_cookie_node(cookie
),
2449 dlm_get_lock_cookie_seq(cookie
),
2450 dlm_list_in_text(idx
));
2456 node_ref
= find_next_bit(res
->refmap
, O2NM_MAX_NODES
, 0);
2457 if (node_ref
>= O2NM_MAX_NODES
)
2461 mlog(0, "%s: res %.*s, Migrateable\n", dlm
->name
, res
->lockname
.len
,
2462 res
->lockname
.name
);
2468 * DLM_MIGRATE_LOCKRES
2472 static int dlm_migrate_lockres(struct dlm_ctxt
*dlm
,
2473 struct dlm_lock_resource
*res
, u8 target
)
2475 struct dlm_master_list_entry
*mle
= NULL
;
2476 struct dlm_master_list_entry
*oldmle
= NULL
;
2477 struct dlm_migratable_lockres
*mres
= NULL
;
2480 unsigned int namelen
;
2487 BUG_ON(target
== O2NM_MAX_NODES
);
2489 name
= res
->lockname
.name
;
2490 namelen
= res
->lockname
.len
;
2492 mlog(0, "%s: Migrating %.*s to node %u\n", dlm
->name
, namelen
, name
,
2495 /* preallocate up front. if this fails, abort */
2497 mres
= (struct dlm_migratable_lockres
*) __get_free_page(GFP_NOFS
);
2503 mle
= kmem_cache_alloc(dlm_mle_cache
, GFP_NOFS
);
2511 * clear any existing master requests and
2512 * add the migration mle to the list
2514 spin_lock(&dlm
->spinlock
);
2515 spin_lock(&dlm
->master_lock
);
2516 ret
= dlm_add_migration_mle(dlm
, res
, mle
, &oldmle
, name
,
2517 namelen
, target
, dlm
->node_num
);
2518 spin_unlock(&dlm
->master_lock
);
2519 spin_unlock(&dlm
->spinlock
);
2521 if (ret
== -EEXIST
) {
2522 mlog(0, "another process is already migrating it\n");
2528 * set the MIGRATING flag and flush asts
2529 * if we fail after this we need to re-dirty the lockres
2531 if (dlm_mark_lockres_migrating(dlm
, res
, target
) < 0) {
2532 mlog(ML_ERROR
, "tried to migrate %.*s to %u, but "
2533 "the target went down.\n", res
->lockname
.len
,
2534 res
->lockname
.name
, target
);
2535 spin_lock(&res
->spinlock
);
2536 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
2538 spin_unlock(&res
->spinlock
);
2544 /* master is known, detach if not already detached */
2545 dlm_mle_detach_hb_events(dlm
, oldmle
);
2546 dlm_put_mle(oldmle
);
2551 dlm_mle_detach_hb_events(dlm
, mle
);
2554 kmem_cache_free(dlm_mle_cache
, mle
);
2561 * at this point, we have a migration target, an mle
2562 * in the master list, and the MIGRATING flag set on
2566 /* now that remote nodes are spinning on the MIGRATING flag,
2567 * ensure that all assert_master work is flushed. */
2568 flush_workqueue(dlm
->dlm_worker
);
2570 /* get an extra reference on the mle.
2571 * otherwise the assert_master from the new
2572 * master will destroy this.
2573 * also, make sure that all callers of dlm_get_mle
2574 * take both dlm->spinlock and dlm->master_lock */
2575 spin_lock(&dlm
->spinlock
);
2576 spin_lock(&dlm
->master_lock
);
2577 dlm_get_mle_inuse(mle
);
2578 spin_unlock(&dlm
->master_lock
);
2579 spin_unlock(&dlm
->spinlock
);
2581 /* notify new node and send all lock state */
2582 /* call send_one_lockres with migration flag.
2583 * this serves as notice to the target node that a
2584 * migration is starting. */
2585 ret
= dlm_send_one_lockres(dlm
, res
, mres
, target
,
2586 DLM_MRES_MIGRATION
);
2589 mlog(0, "migration to node %u failed with %d\n",
2591 /* migration failed, detach and clean up mle */
2592 dlm_mle_detach_hb_events(dlm
, mle
);
2594 dlm_put_mle_inuse(mle
);
2595 spin_lock(&res
->spinlock
);
2596 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
2598 spin_unlock(&res
->spinlock
);
2599 if (dlm_is_host_down(ret
))
2600 dlm_wait_for_node_death(dlm
, target
,
2601 DLM_NODE_DEATH_WAIT_MAX
);
2605 /* at this point, the target sends a message to all nodes,
2606 * (using dlm_do_migrate_request). this node is skipped since
2607 * we had to put an mle in the list to begin the process. this
2608 * node now waits for target to do an assert master. this node
2609 * will be the last one notified, ensuring that the migration
2610 * is complete everywhere. if the target dies while this is
2611 * going on, some nodes could potentially see the target as the
2612 * master, so it is important that my recovery finds the migration
2613 * mle and sets the master to UNKNOWN. */
2616 /* wait for new node to assert master */
2618 ret
= wait_event_interruptible_timeout(mle
->wq
,
2619 (atomic_read(&mle
->woken
) == 1),
2620 msecs_to_jiffies(5000));
2623 if (atomic_read(&mle
->woken
) == 1 ||
2624 res
->owner
== target
)
2627 mlog(0, "%s:%.*s: timed out during migration\n",
2628 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
);
2629 /* avoid hang during shutdown when migrating lockres
2630 * to a node which also goes down */
2631 if (dlm_is_node_dead(dlm
, target
)) {
2632 mlog(0, "%s:%.*s: expected migration "
2633 "target %u is no longer up, restarting\n",
2634 dlm
->name
, res
->lockname
.len
,
2635 res
->lockname
.name
, target
);
2637 /* migration failed, detach and clean up mle */
2638 dlm_mle_detach_hb_events(dlm
, mle
);
2640 dlm_put_mle_inuse(mle
);
2641 spin_lock(&res
->spinlock
);
2642 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
2644 spin_unlock(&res
->spinlock
);
2648 mlog(0, "%s:%.*s: caught signal during migration\n",
2649 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
);
2652 /* all done, set the owner, clear the flag */
2653 spin_lock(&res
->spinlock
);
2654 dlm_set_lockres_owner(dlm
, res
, target
);
2655 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
2656 dlm_remove_nonlocal_locks(dlm
, res
);
2657 spin_unlock(&res
->spinlock
);
2660 /* master is known, detach if not already detached */
2661 dlm_mle_detach_hb_events(dlm
, mle
);
2662 dlm_put_mle_inuse(mle
);
2665 dlm_lockres_calc_usage(dlm
, res
);
2668 /* re-dirty the lockres if we failed */
2670 dlm_kick_thread(dlm
, res
);
2672 /* wake up waiters if the MIGRATING flag got set
2673 * but migration failed */
2678 free_page((unsigned long)mres
);
2682 mlog(0, "%s: Migrating %.*s to %u, returns %d\n", dlm
->name
, namelen
,
2687 #define DLM_MIGRATION_RETRY_MS 100
2690 * Should be called only after beginning the domain leave process.
2691 * There should not be any remaining locks on nonlocal lock resources,
2692 * and there should be no local locks left on locally mastered resources.
2694 * Called with the dlm spinlock held, may drop it to do migration, but
2695 * will re-acquire before exit.
2697 * Returns: 1 if dlm->spinlock was dropped/retaken, 0 if never dropped
2699 int dlm_empty_lockres(struct dlm_ctxt
*dlm
, struct dlm_lock_resource
*res
)
2702 int lock_dropped
= 0;
2703 u8 target
= O2NM_MAX_NODES
;
2705 assert_spin_locked(&dlm
->spinlock
);
2707 spin_lock(&res
->spinlock
);
2708 if (dlm_is_lockres_migrateable(dlm
, res
))
2709 target
= dlm_pick_migration_target(dlm
, res
);
2710 spin_unlock(&res
->spinlock
);
2712 if (target
== O2NM_MAX_NODES
)
2715 /* Wheee! Migrate lockres here! Will sleep so drop spinlock. */
2716 spin_unlock(&dlm
->spinlock
);
2718 ret
= dlm_migrate_lockres(dlm
, res
, target
);
2720 mlog(0, "%s: res %.*s, Migrate to node %u failed with %d\n",
2721 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
,
2723 spin_lock(&dlm
->spinlock
);
2725 return lock_dropped
;
2728 int dlm_lock_basts_flushed(struct dlm_ctxt
*dlm
, struct dlm_lock
*lock
)
2731 spin_lock(&dlm
->ast_lock
);
2732 spin_lock(&lock
->spinlock
);
2733 ret
= (list_empty(&lock
->bast_list
) && !lock
->bast_pending
);
2734 spin_unlock(&lock
->spinlock
);
2735 spin_unlock(&dlm
->ast_lock
);
2739 static int dlm_migration_can_proceed(struct dlm_ctxt
*dlm
,
2740 struct dlm_lock_resource
*res
,
2744 spin_lock(&res
->spinlock
);
2745 can_proceed
= !!(res
->state
& DLM_LOCK_RES_MIGRATING
);
2746 spin_unlock(&res
->spinlock
);
2748 /* target has died, so make the caller break out of the
2749 * wait_event, but caller must recheck the domain_map */
2750 spin_lock(&dlm
->spinlock
);
2751 if (!test_bit(mig_target
, dlm
->domain_map
))
2753 spin_unlock(&dlm
->spinlock
);
2757 static int dlm_lockres_is_dirty(struct dlm_ctxt
*dlm
,
2758 struct dlm_lock_resource
*res
)
2761 spin_lock(&res
->spinlock
);
2762 ret
= !!(res
->state
& DLM_LOCK_RES_DIRTY
);
2763 spin_unlock(&res
->spinlock
);
2768 static int dlm_mark_lockres_migrating(struct dlm_ctxt
*dlm
,
2769 struct dlm_lock_resource
*res
,
2774 mlog(0, "dlm_mark_lockres_migrating: %.*s, from %u to %u\n",
2775 res
->lockname
.len
, res
->lockname
.name
, dlm
->node_num
,
2777 /* need to set MIGRATING flag on lockres. this is done by
2778 * ensuring that all asts have been flushed for this lockres. */
2779 spin_lock(&res
->spinlock
);
2780 BUG_ON(res
->migration_pending
);
2781 res
->migration_pending
= 1;
2782 /* strategy is to reserve an extra ast then release
2783 * it below, letting the release do all of the work */
2784 __dlm_lockres_reserve_ast(res
);
2785 spin_unlock(&res
->spinlock
);
2787 /* now flush all the pending asts */
2788 dlm_kick_thread(dlm
, res
);
2789 /* before waiting on DIRTY, block processes which may
2790 * try to dirty the lockres before MIGRATING is set */
2791 spin_lock(&res
->spinlock
);
2792 BUG_ON(res
->state
& DLM_LOCK_RES_BLOCK_DIRTY
);
2793 res
->state
|= DLM_LOCK_RES_BLOCK_DIRTY
;
2794 spin_unlock(&res
->spinlock
);
2795 /* now wait on any pending asts and the DIRTY state */
2796 wait_event(dlm
->ast_wq
, !dlm_lockres_is_dirty(dlm
, res
));
2797 dlm_lockres_release_ast(dlm
, res
);
2799 mlog(0, "about to wait on migration_wq, dirty=%s\n",
2800 res
->state
& DLM_LOCK_RES_DIRTY
? "yes" : "no");
2801 /* if the extra ref we just put was the final one, this
2802 * will pass thru immediately. otherwise, we need to wait
2803 * for the last ast to finish. */
2805 ret
= wait_event_interruptible_timeout(dlm
->migration_wq
,
2806 dlm_migration_can_proceed(dlm
, res
, target
),
2807 msecs_to_jiffies(1000));
2809 mlog(0, "woken again: migrating? %s, dead? %s\n",
2810 res
->state
& DLM_LOCK_RES_MIGRATING
? "yes":"no",
2811 test_bit(target
, dlm
->domain_map
) ? "no":"yes");
2813 mlog(0, "all is well: migrating? %s, dead? %s\n",
2814 res
->state
& DLM_LOCK_RES_MIGRATING
? "yes":"no",
2815 test_bit(target
, dlm
->domain_map
) ? "no":"yes");
2817 if (!dlm_migration_can_proceed(dlm
, res
, target
)) {
2818 mlog(0, "trying again...\n");
2823 /* did the target go down or die? */
2824 spin_lock(&dlm
->spinlock
);
2825 if (!test_bit(target
, dlm
->domain_map
)) {
2826 mlog(ML_ERROR
, "aha. migration target %u just went down\n",
2830 spin_unlock(&dlm
->spinlock
);
2833 * if target is down, we need to clear DLM_LOCK_RES_BLOCK_DIRTY for
2834 * another try; otherwise, we are sure the MIGRATING state is there,
2835 * drop the unneded state which blocked threads trying to DIRTY
2837 spin_lock(&res
->spinlock
);
2838 BUG_ON(!(res
->state
& DLM_LOCK_RES_BLOCK_DIRTY
));
2839 res
->state
&= ~DLM_LOCK_RES_BLOCK_DIRTY
;
2841 BUG_ON(!(res
->state
& DLM_LOCK_RES_MIGRATING
));
2842 spin_unlock(&res
->spinlock
);
2847 * o the DLM_LOCK_RES_MIGRATING flag is set if target not down
2848 * o there are no pending asts on this lockres
2849 * o all processes trying to reserve an ast on this
2850 * lockres must wait for the MIGRATING flag to clear
2855 /* last step in the migration process.
2856 * original master calls this to free all of the dlm_lock
2857 * structures that used to be for other nodes. */
2858 static void dlm_remove_nonlocal_locks(struct dlm_ctxt
*dlm
,
2859 struct dlm_lock_resource
*res
)
2861 struct list_head
*queue
= &res
->granted
;
2863 struct dlm_lock
*lock
, *next
;
2865 assert_spin_locked(&res
->spinlock
);
2867 BUG_ON(res
->owner
== dlm
->node_num
);
2869 for (i
=0; i
<3; i
++) {
2870 list_for_each_entry_safe(lock
, next
, queue
, list
) {
2871 if (lock
->ml
.node
!= dlm
->node_num
) {
2872 mlog(0, "putting lock for node %u\n",
2874 /* be extra careful */
2875 BUG_ON(!list_empty(&lock
->ast_list
));
2876 BUG_ON(!list_empty(&lock
->bast_list
));
2877 BUG_ON(lock
->ast_pending
);
2878 BUG_ON(lock
->bast_pending
);
2879 dlm_lockres_clear_refmap_bit(dlm
, res
,
2881 list_del_init(&lock
->list
);
2883 /* In a normal unlock, we would have added a
2884 * DLM_UNLOCK_FREE_LOCK action. Force it. */
2892 bit
= find_next_bit(res
->refmap
, O2NM_MAX_NODES
, bit
);
2893 if (bit
>= O2NM_MAX_NODES
)
2895 /* do not clear the local node reference, if there is a
2896 * process holding this, let it drop the ref itself */
2897 if (bit
!= dlm
->node_num
) {
2898 mlog(0, "%s:%.*s: node %u had a ref to this "
2899 "migrating lockres, clearing\n", dlm
->name
,
2900 res
->lockname
.len
, res
->lockname
.name
, bit
);
2901 dlm_lockres_clear_refmap_bit(dlm
, res
, bit
);
2908 * Pick a node to migrate the lock resource to. This function selects a
2909 * potential target based first on the locks and then on refmap. It skips
2910 * nodes that are in the process of exiting the domain.
2912 static u8
dlm_pick_migration_target(struct dlm_ctxt
*dlm
,
2913 struct dlm_lock_resource
*res
)
2915 enum dlm_lockres_list idx
;
2916 struct list_head
*queue
= &res
->granted
;
2917 struct dlm_lock
*lock
;
2919 u8 nodenum
= O2NM_MAX_NODES
;
2921 assert_spin_locked(&dlm
->spinlock
);
2922 assert_spin_locked(&res
->spinlock
);
2924 /* Go through all the locks */
2925 for (idx
= DLM_GRANTED_LIST
; idx
<= DLM_BLOCKED_LIST
; idx
++) {
2926 queue
= dlm_list_idx_to_ptr(res
, idx
);
2927 list_for_each_entry(lock
, queue
, list
) {
2928 if (lock
->ml
.node
== dlm
->node_num
)
2930 if (test_bit(lock
->ml
.node
, dlm
->exit_domain_map
))
2932 nodenum
= lock
->ml
.node
;
2937 /* Go thru the refmap */
2940 noderef
= find_next_bit(res
->refmap
, O2NM_MAX_NODES
,
2942 if (noderef
>= O2NM_MAX_NODES
)
2944 if (noderef
== dlm
->node_num
)
2946 if (test_bit(noderef
, dlm
->exit_domain_map
))
2956 /* this is called by the new master once all lockres
2957 * data has been received */
2958 static int dlm_do_migrate_request(struct dlm_ctxt
*dlm
,
2959 struct dlm_lock_resource
*res
,
2960 u8 master
, u8 new_master
,
2961 struct dlm_node_iter
*iter
)
2963 struct dlm_migrate_request migrate
;
2964 int ret
, skip
, status
= 0;
2967 memset(&migrate
, 0, sizeof(migrate
));
2968 migrate
.namelen
= res
->lockname
.len
;
2969 memcpy(migrate
.name
, res
->lockname
.name
, migrate
.namelen
);
2970 migrate
.new_master
= new_master
;
2971 migrate
.master
= master
;
2975 /* send message to all nodes, except the master and myself */
2976 while ((nodenum
= dlm_node_iter_next(iter
)) >= 0) {
2977 if (nodenum
== master
||
2978 nodenum
== new_master
)
2981 /* We could race exit domain. If exited, skip. */
2982 spin_lock(&dlm
->spinlock
);
2983 skip
= (!test_bit(nodenum
, dlm
->domain_map
));
2984 spin_unlock(&dlm
->spinlock
);
2986 clear_bit(nodenum
, iter
->node_map
);
2990 ret
= o2net_send_message(DLM_MIGRATE_REQUEST_MSG
, dlm
->key
,
2991 &migrate
, sizeof(migrate
), nodenum
,
2994 mlog(ML_ERROR
, "%s: res %.*s, Error %d send "
2995 "MIGRATE_REQUEST to node %u\n", dlm
->name
,
2996 migrate
.namelen
, migrate
.name
, ret
, nodenum
);
2997 if (!dlm_is_host_down(ret
)) {
2998 mlog(ML_ERROR
, "unhandled error=%d!\n", ret
);
3001 clear_bit(nodenum
, iter
->node_map
);
3003 } else if (status
< 0) {
3004 mlog(0, "migrate request (node %u) returned %d!\n",
3007 } else if (status
== DLM_MIGRATE_RESPONSE_MASTERY_REF
) {
3008 /* during the migration request we short-circuited
3009 * the mastery of the lockres. make sure we have
3010 * a mastery ref for nodenum */
3011 mlog(0, "%s:%.*s: need ref for node %u\n",
3012 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
,
3014 spin_lock(&res
->spinlock
);
3015 dlm_lockres_set_refmap_bit(dlm
, res
, nodenum
);
3016 spin_unlock(&res
->spinlock
);
3023 mlog(0, "returning ret=%d\n", ret
);
3028 /* if there is an existing mle for this lockres, we now know who the master is.
3029 * (the one who sent us *this* message) we can clear it up right away.
3030 * since the process that put the mle on the list still has a reference to it,
3031 * we can unhash it now, set the master and wake the process. as a result,
3032 * we will have no mle in the list to start with. now we can add an mle for
3033 * the migration and this should be the only one found for those scanning the
3035 int dlm_migrate_request_handler(struct o2net_msg
*msg
, u32 len
, void *data
,
3038 struct dlm_ctxt
*dlm
= data
;
3039 struct dlm_lock_resource
*res
= NULL
;
3040 struct dlm_migrate_request
*migrate
= (struct dlm_migrate_request
*) msg
->buf
;
3041 struct dlm_master_list_entry
*mle
= NULL
, *oldmle
= NULL
;
3043 unsigned int namelen
, hash
;
3049 name
= migrate
->name
;
3050 namelen
= migrate
->namelen
;
3051 hash
= dlm_lockid_hash(name
, namelen
);
3053 /* preallocate.. if this fails, abort */
3054 mle
= kmem_cache_alloc(dlm_mle_cache
, GFP_NOFS
);
3061 /* check for pre-existing lock */
3062 spin_lock(&dlm
->spinlock
);
3063 res
= __dlm_lookup_lockres(dlm
, name
, namelen
, hash
);
3065 spin_lock(&res
->spinlock
);
3066 if (res
->state
& DLM_LOCK_RES_RECOVERING
) {
3067 /* if all is working ok, this can only mean that we got
3068 * a migrate request from a node that we now see as
3069 * dead. what can we do here? drop it to the floor? */
3070 spin_unlock(&res
->spinlock
);
3071 mlog(ML_ERROR
, "Got a migrate request, but the "
3072 "lockres is marked as recovering!");
3073 kmem_cache_free(dlm_mle_cache
, mle
);
3074 ret
= -EINVAL
; /* need a better solution */
3077 res
->state
|= DLM_LOCK_RES_MIGRATING
;
3078 spin_unlock(&res
->spinlock
);
3081 spin_lock(&dlm
->master_lock
);
3082 /* ignore status. only nonzero status would BUG. */
3083 ret
= dlm_add_migration_mle(dlm
, res
, mle
, &oldmle
,
3085 migrate
->new_master
,
3088 spin_unlock(&dlm
->master_lock
);
3090 spin_unlock(&dlm
->spinlock
);
3093 /* master is known, detach if not already detached */
3094 dlm_mle_detach_hb_events(dlm
, oldmle
);
3095 dlm_put_mle(oldmle
);
3099 dlm_lockres_put(res
);
3105 /* must be holding dlm->spinlock and dlm->master_lock
3106 * when adding a migration mle, we can clear any other mles
3107 * in the master list because we know with certainty that
3108 * the master is "master". so we remove any old mle from
3109 * the list after setting it's master field, and then add
3110 * the new migration mle. this way we can hold with the rule
3111 * of having only one mle for a given lock name at all times. */
3112 static int dlm_add_migration_mle(struct dlm_ctxt
*dlm
,
3113 struct dlm_lock_resource
*res
,
3114 struct dlm_master_list_entry
*mle
,
3115 struct dlm_master_list_entry
**oldmle
,
3116 const char *name
, unsigned int namelen
,
3117 u8 new_master
, u8 master
)
3124 assert_spin_locked(&dlm
->spinlock
);
3125 assert_spin_locked(&dlm
->master_lock
);
3127 /* caller is responsible for any ref taken here on oldmle */
3128 found
= dlm_find_mle(dlm
, oldmle
, (char *)name
, namelen
);
3130 struct dlm_master_list_entry
*tmp
= *oldmle
;
3131 spin_lock(&tmp
->spinlock
);
3132 if (tmp
->type
== DLM_MLE_MIGRATION
) {
3133 if (master
== dlm
->node_num
) {
3134 /* ah another process raced me to it */
3135 mlog(0, "tried to migrate %.*s, but some "
3136 "process beat me to it\n",
3140 /* bad. 2 NODES are trying to migrate! */
3141 mlog(ML_ERROR
, "migration error mle: "
3142 "master=%u new_master=%u // request: "
3143 "master=%u new_master=%u // "
3145 tmp
->master
, tmp
->new_master
,
3151 /* this is essentially what assert_master does */
3152 tmp
->master
= master
;
3153 atomic_set(&tmp
->woken
, 1);
3155 /* remove it so that only one mle will be found */
3156 __dlm_unlink_mle(dlm
, tmp
);
3157 __dlm_mle_detach_hb_events(dlm
, tmp
);
3158 if (tmp
->type
== DLM_MLE_MASTER
) {
3159 ret
= DLM_MIGRATE_RESPONSE_MASTERY_REF
;
3160 mlog(0, "%s:%.*s: master=%u, newmaster=%u, "
3161 "telling master to get ref "
3162 "for cleared out mle during "
3163 "migration\n", dlm
->name
,
3164 namelen
, name
, master
,
3168 spin_unlock(&tmp
->spinlock
);
3171 /* now add a migration mle to the tail of the list */
3172 dlm_init_mle(mle
, DLM_MLE_MIGRATION
, dlm
, res
, name
, namelen
);
3173 mle
->new_master
= new_master
;
3174 /* the new master will be sending an assert master for this.
3175 * at that point we will get the refmap reference */
3176 mle
->master
= master
;
3177 /* do this for consistency with other mle types */
3178 set_bit(new_master
, mle
->maybe_map
);
3179 __dlm_insert_mle(dlm
, mle
);
3185 * Sets the owner of the lockres, associated to the mle, to UNKNOWN
3187 static struct dlm_lock_resource
*dlm_reset_mleres_owner(struct dlm_ctxt
*dlm
,
3188 struct dlm_master_list_entry
*mle
)
3190 struct dlm_lock_resource
*res
;
3192 /* Find the lockres associated to the mle and set its owner to UNK */
3193 res
= __dlm_lookup_lockres(dlm
, mle
->mname
, mle
->mnamelen
,
3196 spin_unlock(&dlm
->master_lock
);
3198 /* move lockres onto recovery list */
3199 spin_lock(&res
->spinlock
);
3200 dlm_set_lockres_owner(dlm
, res
, DLM_LOCK_RES_OWNER_UNKNOWN
);
3201 dlm_move_lockres_to_recovery_list(dlm
, res
);
3202 spin_unlock(&res
->spinlock
);
3203 dlm_lockres_put(res
);
3205 /* about to get rid of mle, detach from heartbeat */
3206 __dlm_mle_detach_hb_events(dlm
, mle
);
3209 spin_lock(&dlm
->master_lock
);
3211 spin_unlock(&dlm
->master_lock
);
3217 static void dlm_clean_migration_mle(struct dlm_ctxt
*dlm
,
3218 struct dlm_master_list_entry
*mle
)
3220 __dlm_mle_detach_hb_events(dlm
, mle
);
3222 spin_lock(&mle
->spinlock
);
3223 __dlm_unlink_mle(dlm
, mle
);
3224 atomic_set(&mle
->woken
, 1);
3225 spin_unlock(&mle
->spinlock
);
3230 static void dlm_clean_block_mle(struct dlm_ctxt
*dlm
,
3231 struct dlm_master_list_entry
*mle
, u8 dead_node
)
3235 BUG_ON(mle
->type
!= DLM_MLE_BLOCK
);
3237 spin_lock(&mle
->spinlock
);
3238 bit
= find_next_bit(mle
->maybe_map
, O2NM_MAX_NODES
, 0);
3239 if (bit
!= dead_node
) {
3240 mlog(0, "mle found, but dead node %u would not have been "
3241 "master\n", dead_node
);
3242 spin_unlock(&mle
->spinlock
);
3244 /* Must drop the refcount by one since the assert_master will
3245 * never arrive. This may result in the mle being unlinked and
3246 * freed, but there may still be a process waiting in the
3247 * dlmlock path which is fine. */
3248 mlog(0, "node %u was expected master\n", dead_node
);
3249 atomic_set(&mle
->woken
, 1);
3250 spin_unlock(&mle
->spinlock
);
3253 /* Do not need events any longer, so detach from heartbeat */
3254 __dlm_mle_detach_hb_events(dlm
, mle
);
3259 void dlm_clean_master_list(struct dlm_ctxt
*dlm
, u8 dead_node
)
3261 struct dlm_master_list_entry
*mle
;
3262 struct dlm_lock_resource
*res
;
3263 struct hlist_head
*bucket
;
3264 struct hlist_node
*tmp
;
3267 mlog(0, "dlm=%s, dead node=%u\n", dlm
->name
, dead_node
);
3269 assert_spin_locked(&dlm
->spinlock
);
3271 /* clean the master list */
3272 spin_lock(&dlm
->master_lock
);
3273 for (i
= 0; i
< DLM_HASH_BUCKETS
; i
++) {
3274 bucket
= dlm_master_hash(dlm
, i
);
3275 hlist_for_each_entry_safe(mle
, tmp
, bucket
, master_hash_node
) {
3276 BUG_ON(mle
->type
!= DLM_MLE_BLOCK
&&
3277 mle
->type
!= DLM_MLE_MASTER
&&
3278 mle
->type
!= DLM_MLE_MIGRATION
);
3280 /* MASTER mles are initiated locally. The waiting
3281 * process will notice the node map change shortly.
3282 * Let that happen as normal. */
3283 if (mle
->type
== DLM_MLE_MASTER
)
3286 /* BLOCK mles are initiated by other nodes. Need to
3287 * clean up if the dead node would have been the
3289 if (mle
->type
== DLM_MLE_BLOCK
) {
3290 dlm_clean_block_mle(dlm
, mle
, dead_node
);
3294 /* Everything else is a MIGRATION mle */
3296 /* The rule for MIGRATION mles is that the master
3297 * becomes UNKNOWN if *either* the original or the new
3298 * master dies. All UNKNOWN lockres' are sent to
3299 * whichever node becomes the recovery master. The new
3300 * master is responsible for determining if there is
3301 * still a master for this lockres, or if he needs to
3302 * take over mastery. Either way, this node should
3303 * expect another message to resolve this. */
3305 if (mle
->master
!= dead_node
&&
3306 mle
->new_master
!= dead_node
)
3309 /* If we have reached this point, this mle needs to be
3310 * removed from the list and freed. */
3311 dlm_clean_migration_mle(dlm
, mle
);
3313 mlog(0, "%s: node %u died during migration from "
3314 "%u to %u!\n", dlm
->name
, dead_node
, mle
->master
,
3317 /* If we find a lockres associated with the mle, we've
3318 * hit this rare case that messes up our lock ordering.
3319 * If so, we need to drop the master lock so that we can
3320 * take the lockres lock, meaning that we will have to
3321 * restart from the head of list. */
3322 res
= dlm_reset_mleres_owner(dlm
, mle
);
3327 /* This may be the last reference */
3331 spin_unlock(&dlm
->master_lock
);
3334 int dlm_finish_migration(struct dlm_ctxt
*dlm
, struct dlm_lock_resource
*res
,
3337 struct dlm_node_iter iter
;
3340 spin_lock(&dlm
->spinlock
);
3341 dlm_node_iter_init(dlm
->domain_map
, &iter
);
3342 clear_bit(old_master
, iter
.node_map
);
3343 clear_bit(dlm
->node_num
, iter
.node_map
);
3344 spin_unlock(&dlm
->spinlock
);
3346 /* ownership of the lockres is changing. account for the
3347 * mastery reference here since old_master will briefly have
3348 * a reference after the migration completes */
3349 spin_lock(&res
->spinlock
);
3350 dlm_lockres_set_refmap_bit(dlm
, res
, old_master
);
3351 spin_unlock(&res
->spinlock
);
3353 mlog(0, "now time to do a migrate request to other nodes\n");
3354 ret
= dlm_do_migrate_request(dlm
, res
, old_master
,
3355 dlm
->node_num
, &iter
);
3361 mlog(0, "doing assert master of %.*s to all except the original node\n",
3362 res
->lockname
.len
, res
->lockname
.name
);
3363 /* this call now finishes out the nodemap
3364 * even if one or more nodes die */
3365 ret
= dlm_do_assert_master(dlm
, res
, iter
.node_map
,
3366 DLM_ASSERT_MASTER_FINISH_MIGRATION
);
3368 /* no longer need to retry. all living nodes contacted. */
3373 memset(iter
.node_map
, 0, sizeof(iter
.node_map
));
3374 set_bit(old_master
, iter
.node_map
);
3375 mlog(0, "doing assert master of %.*s back to %u\n",
3376 res
->lockname
.len
, res
->lockname
.name
, old_master
);
3377 ret
= dlm_do_assert_master(dlm
, res
, iter
.node_map
,
3378 DLM_ASSERT_MASTER_FINISH_MIGRATION
);
3380 mlog(0, "assert master to original master failed "
3382 /* the only nonzero status here would be because of
3383 * a dead original node. we're done. */
3387 /* all done, set the owner, clear the flag */
3388 spin_lock(&res
->spinlock
);
3389 dlm_set_lockres_owner(dlm
, res
, dlm
->node_num
);
3390 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
3391 spin_unlock(&res
->spinlock
);
3392 /* re-dirty it on the new master */
3393 dlm_kick_thread(dlm
, res
);
3400 * LOCKRES AST REFCOUNT
3401 * this is integral to migration
3404 /* for future intent to call an ast, reserve one ahead of time.
3405 * this should be called only after waiting on the lockres
3406 * with dlm_wait_on_lockres, and while still holding the
3407 * spinlock after the call. */
3408 void __dlm_lockres_reserve_ast(struct dlm_lock_resource
*res
)
3410 assert_spin_locked(&res
->spinlock
);
3411 if (res
->state
& DLM_LOCK_RES_MIGRATING
) {
3412 __dlm_print_one_lock_resource(res
);
3414 BUG_ON(res
->state
& DLM_LOCK_RES_MIGRATING
);
3416 atomic_inc(&res
->asts_reserved
);
3420 * used to drop the reserved ast, either because it went unused,
3421 * or because the ast/bast was actually called.
3423 * also, if there is a pending migration on this lockres,
3424 * and this was the last pending ast on the lockres,
3425 * atomically set the MIGRATING flag before we drop the lock.
3426 * this is how we ensure that migration can proceed with no
3427 * asts in progress. note that it is ok if the state of the
3428 * queues is such that a lock should be granted in the future
3429 * or that a bast should be fired, because the new master will
3430 * shuffle the lists on this lockres as soon as it is migrated.
3432 void dlm_lockres_release_ast(struct dlm_ctxt
*dlm
,
3433 struct dlm_lock_resource
*res
)
3435 if (!atomic_dec_and_lock(&res
->asts_reserved
, &res
->spinlock
))
3438 if (!res
->migration_pending
) {
3439 spin_unlock(&res
->spinlock
);
3443 BUG_ON(res
->state
& DLM_LOCK_RES_MIGRATING
);
3444 res
->migration_pending
= 0;
3445 res
->state
|= DLM_LOCK_RES_MIGRATING
;
3446 spin_unlock(&res
->spinlock
);
3448 wake_up(&dlm
->migration_wq
);
3451 void dlm_force_free_mles(struct dlm_ctxt
*dlm
)
3454 struct hlist_head
*bucket
;
3455 struct dlm_master_list_entry
*mle
;
3456 struct hlist_node
*tmp
;
3459 * We notified all other nodes that we are exiting the domain and
3460 * marked the dlm state to DLM_CTXT_LEAVING. If any mles are still
3461 * around we force free them and wake any processes that are waiting
3464 spin_lock(&dlm
->spinlock
);
3465 spin_lock(&dlm
->master_lock
);
3467 BUG_ON(dlm
->dlm_state
!= DLM_CTXT_LEAVING
);
3468 BUG_ON((find_next_bit(dlm
->domain_map
, O2NM_MAX_NODES
, 0) < O2NM_MAX_NODES
));
3470 for (i
= 0; i
< DLM_HASH_BUCKETS
; i
++) {
3471 bucket
= dlm_master_hash(dlm
, i
);
3472 hlist_for_each_entry_safe(mle
, tmp
, bucket
, master_hash_node
) {
3473 if (mle
->type
!= DLM_MLE_BLOCK
) {
3474 mlog(ML_ERROR
, "bad mle: %p\n", mle
);
3475 dlm_print_one_mle(mle
);
3477 atomic_set(&mle
->woken
, 1);
3480 __dlm_unlink_mle(dlm
, mle
);
3481 __dlm_mle_detach_hb_events(dlm
, mle
);
3485 spin_unlock(&dlm
->master_lock
);
3486 spin_unlock(&dlm
->spinlock
);