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;
587 kref_init(&res
->refs
);
589 atomic_inc(&dlm
->res_tot_count
);
590 atomic_inc(&dlm
->res_cur_count
);
592 /* just for consistency */
593 spin_lock(&res
->spinlock
);
594 dlm_set_lockres_owner(dlm
, res
, DLM_LOCK_RES_OWNER_UNKNOWN
);
595 spin_unlock(&res
->spinlock
);
597 res
->state
= DLM_LOCK_RES_IN_PROGRESS
;
601 spin_lock(&dlm
->spinlock
);
602 list_add_tail(&res
->tracking
, &dlm
->tracking_list
);
603 spin_unlock(&dlm
->spinlock
);
605 memset(res
->lvb
, 0, DLM_LVB_LEN
);
606 memset(res
->refmap
, 0, sizeof(res
->refmap
));
609 struct dlm_lock_resource
*dlm_new_lockres(struct dlm_ctxt
*dlm
,
611 unsigned int namelen
)
613 struct dlm_lock_resource
*res
= NULL
;
615 res
= kmem_cache_zalloc(dlm_lockres_cache
, GFP_NOFS
);
619 res
->lockname
.name
= kmem_cache_zalloc(dlm_lockname_cache
, GFP_NOFS
);
620 if (!res
->lockname
.name
)
623 dlm_init_lockres(dlm
, res
, name
, namelen
);
627 if (res
&& res
->lockname
.name
)
628 kmem_cache_free(dlm_lockname_cache
, (void *)res
->lockname
.name
);
631 kmem_cache_free(dlm_lockres_cache
, res
);
635 void dlm_lockres_set_refmap_bit(struct dlm_ctxt
*dlm
,
636 struct dlm_lock_resource
*res
, int bit
)
638 assert_spin_locked(&res
->spinlock
);
640 mlog(0, "res %.*s, set node %u, %ps()\n", res
->lockname
.len
,
641 res
->lockname
.name
, bit
, __builtin_return_address(0));
643 set_bit(bit
, res
->refmap
);
646 void dlm_lockres_clear_refmap_bit(struct dlm_ctxt
*dlm
,
647 struct dlm_lock_resource
*res
, int bit
)
649 assert_spin_locked(&res
->spinlock
);
651 mlog(0, "res %.*s, clr node %u, %ps()\n", res
->lockname
.len
,
652 res
->lockname
.name
, bit
, __builtin_return_address(0));
654 clear_bit(bit
, res
->refmap
);
658 void dlm_lockres_grab_inflight_ref(struct dlm_ctxt
*dlm
,
659 struct dlm_lock_resource
*res
)
661 assert_spin_locked(&res
->spinlock
);
663 res
->inflight_locks
++;
665 mlog(0, "%s: res %.*s, inflight++: now %u, %ps()\n", dlm
->name
,
666 res
->lockname
.len
, res
->lockname
.name
, res
->inflight_locks
,
667 __builtin_return_address(0));
670 void dlm_lockres_drop_inflight_ref(struct dlm_ctxt
*dlm
,
671 struct dlm_lock_resource
*res
)
673 assert_spin_locked(&res
->spinlock
);
675 BUG_ON(res
->inflight_locks
== 0);
677 res
->inflight_locks
--;
679 mlog(0, "%s: res %.*s, inflight--: now %u, %ps()\n", dlm
->name
,
680 res
->lockname
.len
, res
->lockname
.name
, res
->inflight_locks
,
681 __builtin_return_address(0));
687 * lookup a lock resource by name.
688 * may already exist in the hashtable.
689 * lockid is null terminated
691 * if not, allocate enough for the lockres and for
692 * the temporary structure used in doing the mastering.
694 * also, do a lookup in the dlm->master_list to see
695 * if another node has begun mastering the same lock.
696 * if so, there should be a block entry in there
697 * for this name, and we should *not* attempt to master
698 * the lock here. need to wait around for that node
699 * to assert_master (or die).
702 struct dlm_lock_resource
* dlm_get_lock_resource(struct dlm_ctxt
*dlm
,
707 struct dlm_lock_resource
*tmpres
=NULL
, *res
=NULL
;
708 struct dlm_master_list_entry
*mle
= NULL
;
709 struct dlm_master_list_entry
*alloc_mle
= NULL
;
712 struct dlm_node_iter iter
;
715 int bit
, wait_on_recovery
= 0;
719 hash
= dlm_lockid_hash(lockid
, namelen
);
721 mlog(0, "get lockres %s (len %d)\n", lockid
, namelen
);
724 spin_lock(&dlm
->spinlock
);
725 tmpres
= __dlm_lookup_lockres_full(dlm
, lockid
, namelen
, hash
);
727 spin_unlock(&dlm
->spinlock
);
728 spin_lock(&tmpres
->spinlock
);
729 /* Wait on the thread that is mastering the resource */
730 if (tmpres
->owner
== DLM_LOCK_RES_OWNER_UNKNOWN
) {
731 __dlm_wait_on_lockres(tmpres
);
732 BUG_ON(tmpres
->owner
== DLM_LOCK_RES_OWNER_UNKNOWN
);
733 spin_unlock(&tmpres
->spinlock
);
734 dlm_lockres_put(tmpres
);
739 /* Wait on the resource purge to complete before continuing */
740 if (tmpres
->state
& DLM_LOCK_RES_DROPPING_REF
) {
741 BUG_ON(tmpres
->owner
== dlm
->node_num
);
742 __dlm_wait_on_lockres_flags(tmpres
,
743 DLM_LOCK_RES_DROPPING_REF
);
744 spin_unlock(&tmpres
->spinlock
);
745 dlm_lockres_put(tmpres
);
750 /* Grab inflight ref to pin the resource */
751 dlm_lockres_grab_inflight_ref(dlm
, tmpres
);
753 spin_unlock(&tmpres
->spinlock
);
755 dlm_lockres_put(res
);
761 spin_unlock(&dlm
->spinlock
);
762 mlog(0, "allocating a new resource\n");
763 /* nothing found and we need to allocate one. */
764 alloc_mle
= kmem_cache_alloc(dlm_mle_cache
, GFP_NOFS
);
767 res
= dlm_new_lockres(dlm
, lockid
, namelen
);
773 mlog(0, "no lockres found, allocated our own: %p\n", res
);
775 if (flags
& LKM_LOCAL
) {
776 /* caller knows it's safe to assume it's not mastered elsewhere
777 * DONE! return right away */
778 spin_lock(&res
->spinlock
);
779 dlm_change_lockres_owner(dlm
, res
, dlm
->node_num
);
780 __dlm_insert_lockres(dlm
, res
);
781 dlm_lockres_grab_inflight_ref(dlm
, res
);
782 spin_unlock(&res
->spinlock
);
783 spin_unlock(&dlm
->spinlock
);
784 /* lockres still marked IN_PROGRESS */
788 /* check master list to see if another node has started mastering it */
789 spin_lock(&dlm
->master_lock
);
791 /* if we found a block, wait for lock to be mastered by another node */
792 blocked
= dlm_find_mle(dlm
, &mle
, (char *)lockid
, namelen
);
795 if (mle
->type
== DLM_MLE_MASTER
) {
796 mlog(ML_ERROR
, "master entry for nonexistent lock!\n");
799 mig
= (mle
->type
== DLM_MLE_MIGRATION
);
800 /* if there is a migration in progress, let the migration
801 * finish before continuing. we can wait for the absence
802 * of the MIGRATION mle: either the migrate finished or
803 * one of the nodes died and the mle was cleaned up.
804 * if there is a BLOCK here, but it already has a master
805 * set, we are too late. the master does not have a ref
806 * for us in the refmap. detach the mle and drop it.
807 * either way, go back to the top and start over. */
808 if (mig
|| mle
->master
!= O2NM_MAX_NODES
) {
809 BUG_ON(mig
&& mle
->master
== dlm
->node_num
);
810 /* we arrived too late. the master does not
811 * have a ref for us. retry. */
812 mlog(0, "%s:%.*s: late on %s\n",
813 dlm
->name
, namelen
, lockid
,
814 mig
? "MIGRATION" : "BLOCK");
815 spin_unlock(&dlm
->master_lock
);
816 spin_unlock(&dlm
->spinlock
);
818 /* master is known, detach */
820 dlm_mle_detach_hb_events(dlm
, mle
);
823 /* this is lame, but we can't wait on either
824 * the mle or lockres waitqueue here */
830 /* go ahead and try to master lock on this node */
832 /* make sure this does not get freed below */
834 dlm_init_mle(mle
, DLM_MLE_MASTER
, dlm
, res
, NULL
, 0);
835 set_bit(dlm
->node_num
, mle
->maybe_map
);
836 __dlm_insert_mle(dlm
, mle
);
838 /* still holding the dlm spinlock, check the recovery map
839 * to see if there are any nodes that still need to be
840 * considered. these will not appear in the mle nodemap
841 * but they might own this lockres. wait on them. */
842 bit
= find_next_bit(dlm
->recovery_map
, O2NM_MAX_NODES
, 0);
843 if (bit
< O2NM_MAX_NODES
) {
844 mlog(0, "%s: res %.*s, At least one node (%d) "
845 "to recover before lock mastery can begin\n",
846 dlm
->name
, namelen
, (char *)lockid
, bit
);
847 wait_on_recovery
= 1;
851 /* at this point there is either a DLM_MLE_BLOCK or a
852 * DLM_MLE_MASTER on the master list, so it's safe to add the
853 * lockres to the hashtable. anyone who finds the lock will
854 * still have to wait on the IN_PROGRESS. */
856 /* finally add the lockres to its hash bucket */
857 __dlm_insert_lockres(dlm
, res
);
859 /* Grab inflight ref to pin the resource */
860 spin_lock(&res
->spinlock
);
861 dlm_lockres_grab_inflight_ref(dlm
, res
);
862 spin_unlock(&res
->spinlock
);
864 /* get an extra ref on the mle in case this is a BLOCK
865 * if so, the creator of the BLOCK may try to put the last
866 * ref at this time in the assert master handler, so we
867 * need an extra one to keep from a bad ptr deref. */
868 dlm_get_mle_inuse(mle
);
869 spin_unlock(&dlm
->master_lock
);
870 spin_unlock(&dlm
->spinlock
);
873 while (wait_on_recovery
) {
874 /* any cluster changes that occurred after dropping the
875 * dlm spinlock would be detectable be a change on the mle,
876 * so we only need to clear out the recovery map once. */
877 if (dlm_is_recovery_lock(lockid
, namelen
)) {
878 mlog(0, "%s: Recovery map is not empty, but must "
879 "master $RECOVERY lock now\n", dlm
->name
);
880 if (!dlm_pre_master_reco_lockres(dlm
, res
))
881 wait_on_recovery
= 0;
883 mlog(0, "%s: waiting 500ms for heartbeat state "
884 "change\n", dlm
->name
);
890 dlm_kick_recovery_thread(dlm
);
892 dlm_wait_for_recovery(dlm
);
894 spin_lock(&dlm
->spinlock
);
895 bit
= find_next_bit(dlm
->recovery_map
, O2NM_MAX_NODES
, 0);
896 if (bit
< O2NM_MAX_NODES
) {
897 mlog(0, "%s: res %.*s, At least one node (%d) "
898 "to recover before lock mastery can begin\n",
899 dlm
->name
, namelen
, (char *)lockid
, bit
);
900 wait_on_recovery
= 1;
902 wait_on_recovery
= 0;
903 spin_unlock(&dlm
->spinlock
);
905 if (wait_on_recovery
)
906 dlm_wait_for_node_recovery(dlm
, bit
, 10000);
909 /* must wait for lock to be mastered elsewhere */
914 dlm_node_iter_init(mle
->vote_map
, &iter
);
915 while ((nodenum
= dlm_node_iter_next(&iter
)) >= 0) {
916 ret
= dlm_do_master_request(res
, mle
, nodenum
);
919 if (mle
->master
!= O2NM_MAX_NODES
) {
920 /* found a master ! */
921 if (mle
->master
<= nodenum
)
923 /* if our master request has not reached the master
924 * yet, keep going until it does. this is how the
925 * master will know that asserts are needed back to
926 * the lower nodes. */
927 mlog(0, "%s: res %.*s, Requests only up to %u but "
928 "master is %u, keep going\n", dlm
->name
, namelen
,
929 lockid
, nodenum
, mle
->master
);
934 /* keep going until the response map includes all nodes */
935 ret
= dlm_wait_for_lock_mastery(dlm
, res
, mle
, &blocked
);
937 wait_on_recovery
= 1;
938 mlog(0, "%s: res %.*s, Node map changed, redo the master "
939 "request now, blocked=%d\n", dlm
->name
, res
->lockname
.len
,
940 res
->lockname
.name
, blocked
);
942 mlog(ML_ERROR
, "%s: res %.*s, Spinning on "
943 "dlm_wait_for_lock_mastery, blocked = %d\n",
944 dlm
->name
, res
->lockname
.len
,
945 res
->lockname
.name
, blocked
);
946 dlm_print_one_lock_resource(res
);
947 dlm_print_one_mle(mle
);
953 mlog(0, "%s: res %.*s, Mastered by %u\n", dlm
->name
, res
->lockname
.len
,
954 res
->lockname
.name
, res
->owner
);
955 /* make sure we never continue without this */
956 BUG_ON(res
->owner
== O2NM_MAX_NODES
);
958 /* master is known, detach if not already detached */
959 dlm_mle_detach_hb_events(dlm
, mle
);
961 /* put the extra ref */
962 dlm_put_mle_inuse(mle
);
965 spin_lock(&res
->spinlock
);
966 res
->state
&= ~DLM_LOCK_RES_IN_PROGRESS
;
967 spin_unlock(&res
->spinlock
);
971 /* need to free the unused mle */
973 kmem_cache_free(dlm_mle_cache
, alloc_mle
);
979 #define DLM_MASTERY_TIMEOUT_MS 5000
981 static int dlm_wait_for_lock_mastery(struct dlm_ctxt
*dlm
,
982 struct dlm_lock_resource
*res
,
983 struct dlm_master_list_entry
*mle
,
988 int map_changed
, voting_done
;
995 /* check if another node has already become the owner */
996 spin_lock(&res
->spinlock
);
997 if (res
->owner
!= DLM_LOCK_RES_OWNER_UNKNOWN
) {
998 mlog(0, "%s:%.*s: owner is suddenly %u\n", dlm
->name
,
999 res
->lockname
.len
, res
->lockname
.name
, res
->owner
);
1000 spin_unlock(&res
->spinlock
);
1001 /* this will cause the master to re-assert across
1002 * the whole cluster, freeing up mles */
1003 if (res
->owner
!= dlm
->node_num
) {
1004 ret
= dlm_do_master_request(res
, mle
, res
->owner
);
1006 /* give recovery a chance to run */
1007 mlog(ML_ERROR
, "link to %u went down?: %d\n", res
->owner
, ret
);
1015 spin_unlock(&res
->spinlock
);
1017 spin_lock(&mle
->spinlock
);
1019 map_changed
= (memcmp(mle
->vote_map
, mle
->node_map
,
1020 sizeof(mle
->vote_map
)) != 0);
1021 voting_done
= (memcmp(mle
->vote_map
, mle
->response_map
,
1022 sizeof(mle
->vote_map
)) == 0);
1024 /* restart if we hit any errors */
1027 mlog(0, "%s: %.*s: node map changed, restarting\n",
1028 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
);
1029 ret
= dlm_restart_lock_mastery(dlm
, res
, mle
, *blocked
);
1030 b
= (mle
->type
== DLM_MLE_BLOCK
);
1031 if ((*blocked
&& !b
) || (!*blocked
&& b
)) {
1032 mlog(0, "%s:%.*s: status change: old=%d new=%d\n",
1033 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
,
1037 spin_unlock(&mle
->spinlock
);
1042 mlog(0, "%s:%.*s: restart lock mastery succeeded, "
1043 "rechecking now\n", dlm
->name
, res
->lockname
.len
,
1044 res
->lockname
.name
);
1048 mlog(0, "map not changed and voting not done "
1049 "for %s:%.*s\n", dlm
->name
, res
->lockname
.len
,
1050 res
->lockname
.name
);
1054 if (m
!= O2NM_MAX_NODES
) {
1055 /* another node has done an assert!
1060 /* have all nodes responded? */
1061 if (voting_done
&& !*blocked
) {
1062 bit
= find_next_bit(mle
->maybe_map
, O2NM_MAX_NODES
, 0);
1063 if (dlm
->node_num
<= bit
) {
1064 /* my node number is lowest.
1065 * now tell other nodes that I am
1066 * mastering this. */
1067 mle
->master
= dlm
->node_num
;
1068 /* ref was grabbed in get_lock_resource
1069 * will be dropped in dlmlock_master */
1073 /* if voting is done, but we have not received
1074 * an assert master yet, we must sleep */
1078 spin_unlock(&mle
->spinlock
);
1080 /* sleep if we haven't finished voting yet */
1082 unsigned long timeo
= msecs_to_jiffies(DLM_MASTERY_TIMEOUT_MS
);
1085 if (atomic_read(&mle->mle_refs.refcount) < 2)
1086 mlog(ML_ERROR, "mle (%p) refs=%d, name=%.*s\n", mle,
1087 atomic_read(&mle->mle_refs.refcount),
1088 res->lockname.len, res->lockname.name);
1090 atomic_set(&mle
->woken
, 0);
1091 (void)wait_event_timeout(mle
->wq
,
1092 (atomic_read(&mle
->woken
) == 1),
1094 if (res
->owner
== O2NM_MAX_NODES
) {
1095 mlog(0, "%s:%.*s: waiting again\n", dlm
->name
,
1096 res
->lockname
.len
, res
->lockname
.name
);
1099 mlog(0, "done waiting, master is %u\n", res
->owner
);
1107 mlog(0, "about to master %.*s here, this=%u\n",
1108 res
->lockname
.len
, res
->lockname
.name
, m
);
1109 ret
= dlm_do_assert_master(dlm
, res
, mle
->vote_map
, 0);
1111 /* This is a failure in the network path,
1112 * not in the response to the assert_master
1113 * (any nonzero response is a BUG on this node).
1114 * Most likely a socket just got disconnected
1115 * due to node death. */
1118 /* no longer need to restart lock mastery.
1119 * all living nodes have been contacted. */
1123 /* set the lockres owner */
1124 spin_lock(&res
->spinlock
);
1125 /* mastery reference obtained either during
1126 * assert_master_handler or in get_lock_resource */
1127 dlm_change_lockres_owner(dlm
, res
, m
);
1128 spin_unlock(&res
->spinlock
);
1134 struct dlm_bitmap_diff_iter
1137 unsigned long *orig_bm
;
1138 unsigned long *cur_bm
;
1139 unsigned long diff_bm
[BITS_TO_LONGS(O2NM_MAX_NODES
)];
1142 enum dlm_node_state_change
1149 static void dlm_bitmap_diff_iter_init(struct dlm_bitmap_diff_iter
*iter
,
1150 unsigned long *orig_bm
,
1151 unsigned long *cur_bm
)
1153 unsigned long p1
, p2
;
1157 iter
->orig_bm
= orig_bm
;
1158 iter
->cur_bm
= cur_bm
;
1160 for (i
= 0; i
< BITS_TO_LONGS(O2NM_MAX_NODES
); i
++) {
1161 p1
= *(iter
->orig_bm
+ i
);
1162 p2
= *(iter
->cur_bm
+ i
);
1163 iter
->diff_bm
[i
] = (p1
& ~p2
) | (p2
& ~p1
);
1167 static int dlm_bitmap_diff_iter_next(struct dlm_bitmap_diff_iter
*iter
,
1168 enum dlm_node_state_change
*state
)
1172 if (iter
->curnode
>= O2NM_MAX_NODES
)
1175 bit
= find_next_bit(iter
->diff_bm
, O2NM_MAX_NODES
,
1177 if (bit
>= O2NM_MAX_NODES
) {
1178 iter
->curnode
= O2NM_MAX_NODES
;
1182 /* if it was there in the original then this node died */
1183 if (test_bit(bit
, iter
->orig_bm
))
1188 iter
->curnode
= bit
;
1193 static int dlm_restart_lock_mastery(struct dlm_ctxt
*dlm
,
1194 struct dlm_lock_resource
*res
,
1195 struct dlm_master_list_entry
*mle
,
1198 struct dlm_bitmap_diff_iter bdi
;
1199 enum dlm_node_state_change sc
;
1203 mlog(0, "something happened such that the "
1204 "master process may need to be restarted!\n");
1206 assert_spin_locked(&mle
->spinlock
);
1208 dlm_bitmap_diff_iter_init(&bdi
, mle
->vote_map
, mle
->node_map
);
1209 node
= dlm_bitmap_diff_iter_next(&bdi
, &sc
);
1211 if (sc
== NODE_UP
) {
1212 /* a node came up. clear any old vote from
1213 * the response map and set it in the vote map
1214 * then restart the mastery. */
1215 mlog(ML_NOTICE
, "node %d up while restarting\n", node
);
1217 /* redo the master request, but only for the new node */
1218 mlog(0, "sending request to new node\n");
1219 clear_bit(node
, mle
->response_map
);
1220 set_bit(node
, mle
->vote_map
);
1222 mlog(ML_ERROR
, "node down! %d\n", node
);
1224 int lowest
= find_next_bit(mle
->maybe_map
,
1227 /* act like it was never there */
1228 clear_bit(node
, mle
->maybe_map
);
1230 if (node
== lowest
) {
1231 mlog(0, "expected master %u died"
1232 " while this node was blocked "
1233 "waiting on it!\n", node
);
1234 lowest
= find_next_bit(mle
->maybe_map
,
1237 if (lowest
< O2NM_MAX_NODES
) {
1238 mlog(0, "%s:%.*s:still "
1239 "blocked. waiting on %u "
1245 /* mle is an MLE_BLOCK, but
1246 * there is now nothing left to
1247 * block on. we need to return
1248 * all the way back out and try
1249 * again with an MLE_MASTER.
1250 * dlm_do_local_recovery_cleanup
1251 * has already run, so the mle
1253 mlog(0, "%s:%.*s: no "
1254 "longer blocking. try to "
1255 "master this here\n",
1258 res
->lockname
.name
);
1259 mle
->type
= DLM_MLE_MASTER
;
1265 /* now blank out everything, as if we had never
1266 * contacted anyone */
1267 memset(mle
->maybe_map
, 0, sizeof(mle
->maybe_map
));
1268 memset(mle
->response_map
, 0, sizeof(mle
->response_map
));
1269 /* reset the vote_map to the current node_map */
1270 memcpy(mle
->vote_map
, mle
->node_map
,
1271 sizeof(mle
->node_map
));
1272 /* put myself into the maybe map */
1273 if (mle
->type
!= DLM_MLE_BLOCK
)
1274 set_bit(dlm
->node_num
, mle
->maybe_map
);
1277 node
= dlm_bitmap_diff_iter_next(&bdi
, &sc
);
1284 * DLM_MASTER_REQUEST_MSG
1286 * returns: 0 on success,
1287 * -errno on a network error
1289 * on error, the caller should assume the target node is "dead"
1293 static int dlm_do_master_request(struct dlm_lock_resource
*res
,
1294 struct dlm_master_list_entry
*mle
, int to
)
1296 struct dlm_ctxt
*dlm
= mle
->dlm
;
1297 struct dlm_master_request request
;
1298 int ret
, response
=0, resend
;
1300 memset(&request
, 0, sizeof(request
));
1301 request
.node_idx
= dlm
->node_num
;
1303 BUG_ON(mle
->type
== DLM_MLE_MIGRATION
);
1305 request
.namelen
= (u8
)mle
->mnamelen
;
1306 memcpy(request
.name
, mle
->mname
, request
.namelen
);
1309 ret
= o2net_send_message(DLM_MASTER_REQUEST_MSG
, dlm
->key
, &request
,
1310 sizeof(request
), to
, &response
);
1312 if (ret
== -ESRCH
) {
1313 /* should never happen */
1314 mlog(ML_ERROR
, "TCP stack not ready!\n");
1316 } else if (ret
== -EINVAL
) {
1317 mlog(ML_ERROR
, "bad args passed to o2net!\n");
1319 } else if (ret
== -ENOMEM
) {
1320 mlog(ML_ERROR
, "out of memory while trying to send "
1321 "network message! retrying\n");
1322 /* this is totally crude */
1325 } else if (!dlm_is_host_down(ret
)) {
1326 /* not a network error. bad. */
1328 mlog(ML_ERROR
, "unhandled error!");
1331 /* all other errors should be network errors,
1332 * and likely indicate node death */
1333 mlog(ML_ERROR
, "link to %d went down!\n", to
);
1339 spin_lock(&mle
->spinlock
);
1341 case DLM_MASTER_RESP_YES
:
1342 set_bit(to
, mle
->response_map
);
1343 mlog(0, "node %u is the master, response=YES\n", to
);
1344 mlog(0, "%s:%.*s: master node %u now knows I have a "
1345 "reference\n", dlm
->name
, res
->lockname
.len
,
1346 res
->lockname
.name
, to
);
1349 case DLM_MASTER_RESP_NO
:
1350 mlog(0, "node %u not master, response=NO\n", to
);
1351 set_bit(to
, mle
->response_map
);
1353 case DLM_MASTER_RESP_MAYBE
:
1354 mlog(0, "node %u not master, response=MAYBE\n", to
);
1355 set_bit(to
, mle
->response_map
);
1356 set_bit(to
, mle
->maybe_map
);
1358 case DLM_MASTER_RESP_ERROR
:
1359 mlog(0, "node %u hit an error, resending\n", to
);
1364 mlog(ML_ERROR
, "bad response! %u\n", response
);
1367 spin_unlock(&mle
->spinlock
);
1369 /* this is also totally crude */
1379 * locks that can be taken here:
1385 * if possible, TRIM THIS DOWN!!!
1387 int dlm_master_request_handler(struct o2net_msg
*msg
, u32 len
, void *data
,
1390 u8 response
= DLM_MASTER_RESP_MAYBE
;
1391 struct dlm_ctxt
*dlm
= data
;
1392 struct dlm_lock_resource
*res
= NULL
;
1393 struct dlm_master_request
*request
= (struct dlm_master_request
*) msg
->buf
;
1394 struct dlm_master_list_entry
*mle
= NULL
, *tmpmle
= NULL
;
1396 unsigned int namelen
, hash
;
1399 int dispatch_assert
= 0;
1402 return DLM_MASTER_RESP_NO
;
1404 if (!dlm_domain_fully_joined(dlm
)) {
1405 response
= DLM_MASTER_RESP_NO
;
1409 name
= request
->name
;
1410 namelen
= request
->namelen
;
1411 hash
= dlm_lockid_hash(name
, namelen
);
1413 if (namelen
> DLM_LOCKID_NAME_MAX
) {
1414 response
= DLM_IVBUFLEN
;
1419 spin_lock(&dlm
->spinlock
);
1420 res
= __dlm_lookup_lockres(dlm
, name
, namelen
, hash
);
1422 spin_unlock(&dlm
->spinlock
);
1424 /* take care of the easy cases up front */
1425 spin_lock(&res
->spinlock
);
1426 if (res
->state
& (DLM_LOCK_RES_RECOVERING
|
1427 DLM_LOCK_RES_MIGRATING
)) {
1428 spin_unlock(&res
->spinlock
);
1429 mlog(0, "returning DLM_MASTER_RESP_ERROR since res is "
1430 "being recovered/migrated\n");
1431 response
= DLM_MASTER_RESP_ERROR
;
1433 kmem_cache_free(dlm_mle_cache
, mle
);
1437 if (res
->owner
== dlm
->node_num
) {
1438 dlm_lockres_set_refmap_bit(dlm
, res
, request
->node_idx
);
1439 spin_unlock(&res
->spinlock
);
1440 response
= DLM_MASTER_RESP_YES
;
1442 kmem_cache_free(dlm_mle_cache
, mle
);
1444 /* this node is the owner.
1445 * there is some extra work that needs to
1446 * happen now. the requesting node has
1447 * caused all nodes up to this one to
1448 * create mles. this node now needs to
1449 * go back and clean those up. */
1450 dispatch_assert
= 1;
1452 } else if (res
->owner
!= DLM_LOCK_RES_OWNER_UNKNOWN
) {
1453 spin_unlock(&res
->spinlock
);
1454 // mlog(0, "node %u is the master\n", res->owner);
1455 response
= DLM_MASTER_RESP_NO
;
1457 kmem_cache_free(dlm_mle_cache
, mle
);
1461 /* ok, there is no owner. either this node is
1462 * being blocked, or it is actively trying to
1463 * master this lock. */
1464 if (!(res
->state
& DLM_LOCK_RES_IN_PROGRESS
)) {
1465 mlog(ML_ERROR
, "lock with no owner should be "
1470 // mlog(0, "lockres is in progress...\n");
1471 spin_lock(&dlm
->master_lock
);
1472 found
= dlm_find_mle(dlm
, &tmpmle
, name
, namelen
);
1474 mlog(ML_ERROR
, "no mle found for this lock!\n");
1478 spin_lock(&tmpmle
->spinlock
);
1479 if (tmpmle
->type
== DLM_MLE_BLOCK
) {
1480 // mlog(0, "this node is waiting for "
1481 // "lockres to be mastered\n");
1482 response
= DLM_MASTER_RESP_NO
;
1483 } else if (tmpmle
->type
== DLM_MLE_MIGRATION
) {
1484 mlog(0, "node %u is master, but trying to migrate to "
1485 "node %u.\n", tmpmle
->master
, tmpmle
->new_master
);
1486 if (tmpmle
->master
== dlm
->node_num
) {
1487 mlog(ML_ERROR
, "no owner on lockres, but this "
1488 "node is trying to migrate it to %u?!\n",
1489 tmpmle
->new_master
);
1492 /* the real master can respond on its own */
1493 response
= DLM_MASTER_RESP_NO
;
1495 } else if (tmpmle
->master
!= DLM_LOCK_RES_OWNER_UNKNOWN
) {
1497 if (tmpmle
->master
== dlm
->node_num
) {
1498 response
= DLM_MASTER_RESP_YES
;
1499 /* this node will be the owner.
1500 * go back and clean the mles on any
1502 dispatch_assert
= 1;
1503 dlm_lockres_set_refmap_bit(dlm
, res
,
1506 response
= DLM_MASTER_RESP_NO
;
1508 // mlog(0, "this node is attempting to "
1509 // "master lockres\n");
1510 response
= DLM_MASTER_RESP_MAYBE
;
1513 set_bit(request
->node_idx
, tmpmle
->maybe_map
);
1514 spin_unlock(&tmpmle
->spinlock
);
1516 spin_unlock(&dlm
->master_lock
);
1517 spin_unlock(&res
->spinlock
);
1519 /* keep the mle attached to heartbeat events */
1520 dlm_put_mle(tmpmle
);
1522 kmem_cache_free(dlm_mle_cache
, mle
);
1527 * lockres doesn't exist on this node
1528 * if there is an MLE_BLOCK, return NO
1529 * if there is an MLE_MASTER, return MAYBE
1530 * otherwise, add an MLE_BLOCK, return NO
1532 spin_lock(&dlm
->master_lock
);
1533 found
= dlm_find_mle(dlm
, &tmpmle
, name
, namelen
);
1535 /* this lockid has never been seen on this node yet */
1536 // mlog(0, "no mle found\n");
1538 spin_unlock(&dlm
->master_lock
);
1539 spin_unlock(&dlm
->spinlock
);
1541 mle
= kmem_cache_alloc(dlm_mle_cache
, GFP_NOFS
);
1543 response
= DLM_MASTER_RESP_ERROR
;
1544 mlog_errno(-ENOMEM
);
1550 // mlog(0, "this is second time thru, already allocated, "
1551 // "add the block.\n");
1552 dlm_init_mle(mle
, DLM_MLE_BLOCK
, dlm
, NULL
, name
, namelen
);
1553 set_bit(request
->node_idx
, mle
->maybe_map
);
1554 __dlm_insert_mle(dlm
, mle
);
1555 response
= DLM_MASTER_RESP_NO
;
1557 // mlog(0, "mle was found\n");
1559 spin_lock(&tmpmle
->spinlock
);
1560 if (tmpmle
->master
== dlm
->node_num
) {
1561 mlog(ML_ERROR
, "no lockres, but an mle with this node as master!\n");
1564 if (tmpmle
->type
== DLM_MLE_BLOCK
)
1565 response
= DLM_MASTER_RESP_NO
;
1566 else if (tmpmle
->type
== DLM_MLE_MIGRATION
) {
1567 mlog(0, "migration mle was found (%u->%u)\n",
1568 tmpmle
->master
, tmpmle
->new_master
);
1569 /* real master can respond on its own */
1570 response
= DLM_MASTER_RESP_NO
;
1572 response
= DLM_MASTER_RESP_MAYBE
;
1574 set_bit(request
->node_idx
, tmpmle
->maybe_map
);
1575 spin_unlock(&tmpmle
->spinlock
);
1577 spin_unlock(&dlm
->master_lock
);
1578 spin_unlock(&dlm
->spinlock
);
1581 /* keep the mle attached to heartbeat events */
1582 dlm_put_mle(tmpmle
);
1586 * __dlm_lookup_lockres() grabbed a reference to this lockres.
1587 * The reference is released by dlm_assert_master_worker() under
1588 * the call to dlm_dispatch_assert_master(). If
1589 * dlm_assert_master_worker() isn't called, we drop it here.
1591 if (dispatch_assert
) {
1592 if (response
!= DLM_MASTER_RESP_YES
)
1593 mlog(ML_ERROR
, "invalid response %d\n", response
);
1595 mlog(ML_ERROR
, "bad lockres while trying to assert!\n");
1598 mlog(0, "%u is the owner of %.*s, cleaning everyone else\n",
1599 dlm
->node_num
, res
->lockname
.len
, res
->lockname
.name
);
1600 ret
= dlm_dispatch_assert_master(dlm
, res
, 0, request
->node_idx
,
1601 DLM_ASSERT_MASTER_MLE_CLEANUP
);
1603 mlog(ML_ERROR
, "failed to dispatch assert master work\n");
1604 response
= DLM_MASTER_RESP_ERROR
;
1605 dlm_lockres_put(res
);
1609 dlm_lockres_put(res
);
1617 * DLM_ASSERT_MASTER_MSG
1622 * NOTE: this can be used for debugging
1623 * can periodically run all locks owned by this node
1624 * and re-assert across the cluster...
1626 static int dlm_do_assert_master(struct dlm_ctxt
*dlm
,
1627 struct dlm_lock_resource
*res
,
1628 void *nodemap
, u32 flags
)
1630 struct dlm_assert_master
assert;
1632 struct dlm_node_iter iter
;
1635 const char *lockname
= res
->lockname
.name
;
1636 unsigned int namelen
= res
->lockname
.len
;
1638 BUG_ON(namelen
> O2NM_MAX_NAME_LEN
);
1640 spin_lock(&res
->spinlock
);
1641 res
->state
|= DLM_LOCK_RES_SETREF_INPROG
;
1642 spin_unlock(&res
->spinlock
);
1647 /* note that if this nodemap is empty, it returns 0 */
1648 dlm_node_iter_init(nodemap
, &iter
);
1649 while ((to
= dlm_node_iter_next(&iter
)) >= 0) {
1651 struct dlm_master_list_entry
*mle
= NULL
;
1653 mlog(0, "sending assert master to %d (%.*s)\n", to
,
1655 memset(&assert, 0, sizeof(assert));
1656 assert.node_idx
= dlm
->node_num
;
1657 assert.namelen
= namelen
;
1658 memcpy(assert.name
, lockname
, namelen
);
1659 assert.flags
= cpu_to_be32(flags
);
1661 tmpret
= o2net_send_message(DLM_ASSERT_MASTER_MSG
, dlm
->key
,
1662 &assert, sizeof(assert), to
, &r
);
1664 mlog(ML_ERROR
, "Error %d when sending message %u (key "
1665 "0x%x) to node %u\n", tmpret
,
1666 DLM_ASSERT_MASTER_MSG
, dlm
->key
, to
);
1667 if (!dlm_is_host_down(tmpret
)) {
1668 mlog(ML_ERROR
, "unhandled error=%d!\n", tmpret
);
1671 /* a node died. finish out the rest of the nodes. */
1672 mlog(0, "link to %d went down!\n", to
);
1673 /* any nonzero status return will do */
1677 /* ok, something horribly messed. kill thyself. */
1678 mlog(ML_ERROR
,"during assert master of %.*s to %u, "
1679 "got %d.\n", namelen
, lockname
, to
, r
);
1680 spin_lock(&dlm
->spinlock
);
1681 spin_lock(&dlm
->master_lock
);
1682 if (dlm_find_mle(dlm
, &mle
, (char *)lockname
,
1684 dlm_print_one_mle(mle
);
1687 spin_unlock(&dlm
->master_lock
);
1688 spin_unlock(&dlm
->spinlock
);
1692 if (r
& DLM_ASSERT_RESPONSE_REASSERT
&&
1693 !(r
& DLM_ASSERT_RESPONSE_MASTERY_REF
)) {
1694 mlog(ML_ERROR
, "%.*s: very strange, "
1695 "master MLE but no lockres on %u\n",
1696 namelen
, lockname
, to
);
1699 if (r
& DLM_ASSERT_RESPONSE_REASSERT
) {
1700 mlog(0, "%.*s: node %u create mles on other "
1701 "nodes and requests a re-assert\n",
1702 namelen
, lockname
, to
);
1705 if (r
& DLM_ASSERT_RESPONSE_MASTERY_REF
) {
1706 mlog(0, "%.*s: node %u has a reference to this "
1707 "lockres, set the bit in the refmap\n",
1708 namelen
, lockname
, to
);
1709 spin_lock(&res
->spinlock
);
1710 dlm_lockres_set_refmap_bit(dlm
, res
, to
);
1711 spin_unlock(&res
->spinlock
);
1718 spin_lock(&res
->spinlock
);
1719 res
->state
&= ~DLM_LOCK_RES_SETREF_INPROG
;
1720 spin_unlock(&res
->spinlock
);
1727 * locks that can be taken here:
1733 * if possible, TRIM THIS DOWN!!!
1735 int dlm_assert_master_handler(struct o2net_msg
*msg
, u32 len
, void *data
,
1738 struct dlm_ctxt
*dlm
= data
;
1739 struct dlm_master_list_entry
*mle
= NULL
;
1740 struct dlm_assert_master
*assert = (struct dlm_assert_master
*)msg
->buf
;
1741 struct dlm_lock_resource
*res
= NULL
;
1743 unsigned int namelen
, hash
;
1745 int master_request
= 0, have_lockres_ref
= 0;
1751 name
= assert->name
;
1752 namelen
= assert->namelen
;
1753 hash
= dlm_lockid_hash(name
, namelen
);
1754 flags
= be32_to_cpu(assert->flags
);
1756 if (namelen
> DLM_LOCKID_NAME_MAX
) {
1757 mlog(ML_ERROR
, "Invalid name length!");
1761 spin_lock(&dlm
->spinlock
);
1764 mlog(0, "assert_master with flags: %u\n", flags
);
1767 spin_lock(&dlm
->master_lock
);
1768 if (!dlm_find_mle(dlm
, &mle
, name
, namelen
)) {
1769 /* not an error, could be master just re-asserting */
1770 mlog(0, "just got an assert_master from %u, but no "
1771 "MLE for it! (%.*s)\n", assert->node_idx
,
1774 int bit
= find_next_bit (mle
->maybe_map
, O2NM_MAX_NODES
, 0);
1775 if (bit
>= O2NM_MAX_NODES
) {
1776 /* not necessarily an error, though less likely.
1777 * could be master just re-asserting. */
1778 mlog(0, "no bits set in the maybe_map, but %u "
1779 "is asserting! (%.*s)\n", assert->node_idx
,
1781 } else if (bit
!= assert->node_idx
) {
1782 if (flags
& DLM_ASSERT_MASTER_MLE_CLEANUP
) {
1783 mlog(0, "master %u was found, %u should "
1784 "back off\n", assert->node_idx
, bit
);
1786 /* with the fix for bug 569, a higher node
1787 * number winning the mastery will respond
1788 * YES to mastery requests, but this node
1789 * had no way of knowing. let it pass. */
1790 mlog(0, "%u is the lowest node, "
1791 "%u is asserting. (%.*s) %u must "
1792 "have begun after %u won.\n", bit
,
1793 assert->node_idx
, namelen
, name
, bit
,
1797 if (mle
->type
== DLM_MLE_MIGRATION
) {
1798 if (flags
& DLM_ASSERT_MASTER_MLE_CLEANUP
) {
1799 mlog(0, "%s:%.*s: got cleanup assert"
1800 " from %u for migration\n",
1801 dlm
->name
, namelen
, name
,
1803 } else if (!(flags
& DLM_ASSERT_MASTER_FINISH_MIGRATION
)) {
1804 mlog(0, "%s:%.*s: got unrelated assert"
1805 " from %u for migration, ignoring\n",
1806 dlm
->name
, namelen
, name
,
1809 spin_unlock(&dlm
->master_lock
);
1810 spin_unlock(&dlm
->spinlock
);
1815 spin_unlock(&dlm
->master_lock
);
1817 /* ok everything checks out with the MLE
1818 * now check to see if there is a lockres */
1819 res
= __dlm_lookup_lockres(dlm
, name
, namelen
, hash
);
1821 spin_lock(&res
->spinlock
);
1822 if (res
->state
& DLM_LOCK_RES_RECOVERING
) {
1823 mlog(ML_ERROR
, "%u asserting but %.*s is "
1824 "RECOVERING!\n", assert->node_idx
, namelen
, name
);
1828 if (res
->owner
!= DLM_LOCK_RES_OWNER_UNKNOWN
&&
1829 res
->owner
!= assert->node_idx
) {
1830 mlog(ML_ERROR
, "DIE! Mastery assert from %u, "
1831 "but current owner is %u! (%.*s)\n",
1832 assert->node_idx
, res
->owner
, namelen
,
1834 __dlm_print_one_lock_resource(res
);
1837 } else if (mle
->type
!= DLM_MLE_MIGRATION
) {
1838 if (res
->owner
!= DLM_LOCK_RES_OWNER_UNKNOWN
) {
1839 /* owner is just re-asserting */
1840 if (res
->owner
== assert->node_idx
) {
1841 mlog(0, "owner %u re-asserting on "
1842 "lock %.*s\n", assert->node_idx
,
1846 mlog(ML_ERROR
, "got assert_master from "
1847 "node %u, but %u is the owner! "
1848 "(%.*s)\n", assert->node_idx
,
1849 res
->owner
, namelen
, name
);
1852 if (!(res
->state
& DLM_LOCK_RES_IN_PROGRESS
)) {
1853 mlog(ML_ERROR
, "got assert from %u, but lock "
1854 "with no owner should be "
1855 "in-progress! (%.*s)\n",
1860 } else /* mle->type == DLM_MLE_MIGRATION */ {
1861 /* should only be getting an assert from new master */
1862 if (assert->node_idx
!= mle
->new_master
) {
1863 mlog(ML_ERROR
, "got assert from %u, but "
1864 "new master is %u, and old master "
1866 assert->node_idx
, mle
->new_master
,
1867 mle
->master
, namelen
, name
);
1873 spin_unlock(&res
->spinlock
);
1876 // mlog(0, "woo! got an assert_master from node %u!\n",
1877 // assert->node_idx);
1883 spin_lock(&mle
->spinlock
);
1884 if (mle
->type
== DLM_MLE_BLOCK
|| mle
->type
== DLM_MLE_MIGRATION
)
1887 /* MASTER mle: if any bits set in the response map
1888 * then the calling node needs to re-assert to clear
1889 * up nodes that this node contacted */
1890 while ((nn
= find_next_bit (mle
->response_map
, O2NM_MAX_NODES
,
1891 nn
+1)) < O2NM_MAX_NODES
) {
1892 if (nn
!= dlm
->node_num
&& nn
!= assert->node_idx
) {
1898 mle
->master
= assert->node_idx
;
1899 atomic_set(&mle
->woken
, 1);
1901 spin_unlock(&mle
->spinlock
);
1905 spin_lock(&res
->spinlock
);
1906 if (mle
->type
== DLM_MLE_MIGRATION
) {
1907 mlog(0, "finishing off migration of lockres %.*s, "
1909 res
->lockname
.len
, res
->lockname
.name
,
1910 dlm
->node_num
, mle
->new_master
);
1911 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
1913 dlm_change_lockres_owner(dlm
, res
, mle
->new_master
);
1914 BUG_ON(res
->state
& DLM_LOCK_RES_DIRTY
);
1916 dlm_change_lockres_owner(dlm
, res
, mle
->master
);
1918 spin_unlock(&res
->spinlock
);
1919 have_lockres_ref
= 1;
1924 /* master is known, detach if not already detached.
1925 * ensures that only one assert_master call will happen
1927 spin_lock(&dlm
->master_lock
);
1929 rr
= atomic_read(&mle
->mle_refs
.refcount
);
1930 if (mle
->inuse
> 0) {
1931 if (extra_ref
&& rr
< 3)
1933 else if (!extra_ref
&& rr
< 2)
1936 if (extra_ref
&& rr
< 2)
1938 else if (!extra_ref
&& rr
< 1)
1942 mlog(ML_ERROR
, "%s:%.*s: got assert master from %u "
1943 "that will mess up this node, refs=%d, extra=%d, "
1944 "inuse=%d\n", dlm
->name
, namelen
, name
,
1945 assert->node_idx
, rr
, extra_ref
, mle
->inuse
);
1946 dlm_print_one_mle(mle
);
1948 __dlm_unlink_mle(dlm
, mle
);
1949 __dlm_mle_detach_hb_events(dlm
, mle
);
1952 /* the assert master message now balances the extra
1953 * ref given by the master / migration request message.
1954 * if this is the last put, it will be removed
1958 spin_unlock(&dlm
->master_lock
);
1960 if (res
->owner
!= assert->node_idx
) {
1961 mlog(0, "assert_master from %u, but current "
1962 "owner is %u (%.*s), no mle\n", assert->node_idx
,
1963 res
->owner
, namelen
, name
);
1966 spin_unlock(&dlm
->spinlock
);
1971 spin_lock(&res
->spinlock
);
1972 res
->state
|= DLM_LOCK_RES_SETREF_INPROG
;
1973 spin_unlock(&res
->spinlock
);
1974 *ret_data
= (void *)res
;
1977 if (master_request
) {
1978 mlog(0, "need to tell master to reassert\n");
1979 /* positive. negative would shoot down the node. */
1980 ret
|= DLM_ASSERT_RESPONSE_REASSERT
;
1981 if (!have_lockres_ref
) {
1982 mlog(ML_ERROR
, "strange, got assert from %u, MASTER "
1983 "mle present here for %s:%.*s, but no lockres!\n",
1984 assert->node_idx
, dlm
->name
, namelen
, name
);
1987 if (have_lockres_ref
) {
1988 /* let the master know we have a reference to the lockres */
1989 ret
|= DLM_ASSERT_RESPONSE_MASTERY_REF
;
1990 mlog(0, "%s:%.*s: got assert from %u, need a ref\n",
1991 dlm
->name
, namelen
, name
, assert->node_idx
);
1996 /* kill the caller! */
1997 mlog(ML_ERROR
, "Bad message received from another node. Dumping state "
1998 "and killing the other node now! This node is OK and can continue.\n");
1999 __dlm_print_one_lock_resource(res
);
2000 spin_unlock(&res
->spinlock
);
2001 spin_unlock(&dlm
->spinlock
);
2002 *ret_data
= (void *)res
;
2007 void dlm_assert_master_post_handler(int status
, void *data
, void *ret_data
)
2009 struct dlm_lock_resource
*res
= (struct dlm_lock_resource
*)ret_data
;
2012 spin_lock(&res
->spinlock
);
2013 res
->state
&= ~DLM_LOCK_RES_SETREF_INPROG
;
2014 spin_unlock(&res
->spinlock
);
2016 dlm_lockres_put(res
);
2021 int dlm_dispatch_assert_master(struct dlm_ctxt
*dlm
,
2022 struct dlm_lock_resource
*res
,
2023 int ignore_higher
, u8 request_from
, u32 flags
)
2025 struct dlm_work_item
*item
;
2026 item
= kzalloc(sizeof(*item
), GFP_ATOMIC
);
2031 /* queue up work for dlm_assert_master_worker */
2032 dlm_grab(dlm
); /* get an extra ref for the work item */
2033 dlm_init_work_item(dlm
, item
, dlm_assert_master_worker
, NULL
);
2034 item
->u
.am
.lockres
= res
; /* already have a ref */
2035 /* can optionally ignore node numbers higher than this node */
2036 item
->u
.am
.ignore_higher
= ignore_higher
;
2037 item
->u
.am
.request_from
= request_from
;
2038 item
->u
.am
.flags
= flags
;
2041 mlog(0, "IGNORE HIGHER: %.*s\n", res
->lockname
.len
,
2042 res
->lockname
.name
);
2044 spin_lock(&dlm
->work_lock
);
2045 list_add_tail(&item
->list
, &dlm
->work_list
);
2046 spin_unlock(&dlm
->work_lock
);
2048 queue_work(dlm
->dlm_worker
, &dlm
->dispatched_work
);
2052 static void dlm_assert_master_worker(struct dlm_work_item
*item
, void *data
)
2054 struct dlm_ctxt
*dlm
= data
;
2056 struct dlm_lock_resource
*res
;
2057 unsigned long nodemap
[BITS_TO_LONGS(O2NM_MAX_NODES
)];
2064 res
= item
->u
.am
.lockres
;
2065 ignore_higher
= item
->u
.am
.ignore_higher
;
2066 request_from
= item
->u
.am
.request_from
;
2067 flags
= item
->u
.am
.flags
;
2069 spin_lock(&dlm
->spinlock
);
2070 memcpy(nodemap
, dlm
->domain_map
, sizeof(nodemap
));
2071 spin_unlock(&dlm
->spinlock
);
2073 clear_bit(dlm
->node_num
, nodemap
);
2074 if (ignore_higher
) {
2075 /* if is this just to clear up mles for nodes below
2076 * this node, do not send the message to the original
2077 * caller or any node number higher than this */
2078 clear_bit(request_from
, nodemap
);
2079 bit
= dlm
->node_num
;
2081 bit
= find_next_bit(nodemap
, O2NM_MAX_NODES
,
2083 if (bit
>= O2NM_MAX_NODES
)
2085 clear_bit(bit
, nodemap
);
2090 * If we're migrating this lock to someone else, we are no
2091 * longer allowed to assert out own mastery. OTOH, we need to
2092 * prevent migration from starting while we're still asserting
2093 * our dominance. The reserved ast delays migration.
2095 spin_lock(&res
->spinlock
);
2096 if (res
->state
& DLM_LOCK_RES_MIGRATING
) {
2097 mlog(0, "Someone asked us to assert mastery, but we're "
2098 "in the middle of migration. Skipping assert, "
2099 "the new master will handle that.\n");
2100 spin_unlock(&res
->spinlock
);
2103 __dlm_lockres_reserve_ast(res
);
2104 spin_unlock(&res
->spinlock
);
2106 /* this call now finishes out the nodemap
2107 * even if one or more nodes die */
2108 mlog(0, "worker about to master %.*s here, this=%u\n",
2109 res
->lockname
.len
, res
->lockname
.name
, dlm
->node_num
);
2110 ret
= dlm_do_assert_master(dlm
, res
, nodemap
, flags
);
2112 /* no need to restart, we are done */
2113 if (!dlm_is_host_down(ret
))
2117 /* Ok, we've asserted ourselves. Let's let migration start. */
2118 dlm_lockres_release_ast(dlm
, res
);
2121 dlm_lockres_put(res
);
2123 mlog(0, "finished with dlm_assert_master_worker\n");
2126 /* SPECIAL CASE for the $RECOVERY lock used by the recovery thread.
2127 * We cannot wait for node recovery to complete to begin mastering this
2128 * lockres because this lockres is used to kick off recovery! ;-)
2129 * So, do a pre-check on all living nodes to see if any of those nodes
2130 * think that $RECOVERY is currently mastered by a dead node. If so,
2131 * we wait a short time to allow that node to get notified by its own
2132 * heartbeat stack, then check again. All $RECOVERY lock resources
2133 * mastered by dead nodes are purged when the hearbeat callback is
2134 * fired, so we can know for sure that it is safe to continue once
2135 * the node returns a live node or no node. */
2136 static int dlm_pre_master_reco_lockres(struct dlm_ctxt
*dlm
,
2137 struct dlm_lock_resource
*res
)
2139 struct dlm_node_iter iter
;
2142 u8 master
= DLM_LOCK_RES_OWNER_UNKNOWN
;
2144 spin_lock(&dlm
->spinlock
);
2145 dlm_node_iter_init(dlm
->domain_map
, &iter
);
2146 spin_unlock(&dlm
->spinlock
);
2148 while ((nodenum
= dlm_node_iter_next(&iter
)) >= 0) {
2149 /* do not send to self */
2150 if (nodenum
== dlm
->node_num
)
2152 ret
= dlm_do_master_requery(dlm
, res
, nodenum
, &master
);
2155 if (!dlm_is_host_down(ret
))
2157 /* host is down, so answer for that node would be
2158 * DLM_LOCK_RES_OWNER_UNKNOWN. continue. */
2162 if (master
!= DLM_LOCK_RES_OWNER_UNKNOWN
) {
2163 /* check to see if this master is in the recovery map */
2164 spin_lock(&dlm
->spinlock
);
2165 if (test_bit(master
, dlm
->recovery_map
)) {
2166 mlog(ML_NOTICE
, "%s: node %u has not seen "
2167 "node %u go down yet, and thinks the "
2168 "dead node is mastering the recovery "
2169 "lock. must wait.\n", dlm
->name
,
2173 spin_unlock(&dlm
->spinlock
);
2174 mlog(0, "%s: reco lock master is %u\n", dlm
->name
,
2183 * DLM_DEREF_LOCKRES_MSG
2186 int dlm_drop_lockres_ref(struct dlm_ctxt
*dlm
, struct dlm_lock_resource
*res
)
2188 struct dlm_deref_lockres deref
;
2190 const char *lockname
;
2191 unsigned int namelen
;
2193 lockname
= res
->lockname
.name
;
2194 namelen
= res
->lockname
.len
;
2195 BUG_ON(namelen
> O2NM_MAX_NAME_LEN
);
2197 memset(&deref
, 0, sizeof(deref
));
2198 deref
.node_idx
= dlm
->node_num
;
2199 deref
.namelen
= namelen
;
2200 memcpy(deref
.name
, lockname
, namelen
);
2202 ret
= o2net_send_message(DLM_DEREF_LOCKRES_MSG
, dlm
->key
,
2203 &deref
, sizeof(deref
), res
->owner
, &r
);
2205 mlog(ML_ERROR
, "%s: res %.*s, error %d send DEREF to node %u\n",
2206 dlm
->name
, namelen
, lockname
, ret
, res
->owner
);
2208 /* BAD. other node says I did not have a ref. */
2209 mlog(ML_ERROR
, "%s: res %.*s, DEREF to node %u got %d\n",
2210 dlm
->name
, namelen
, lockname
, res
->owner
, r
);
2211 dlm_print_one_lock_resource(res
);
2217 int dlm_deref_lockres_handler(struct o2net_msg
*msg
, u32 len
, void *data
,
2220 struct dlm_ctxt
*dlm
= data
;
2221 struct dlm_deref_lockres
*deref
= (struct dlm_deref_lockres
*)msg
->buf
;
2222 struct dlm_lock_resource
*res
= NULL
;
2224 unsigned int namelen
;
2228 struct dlm_work_item
*item
;
2236 namelen
= deref
->namelen
;
2237 node
= deref
->node_idx
;
2239 if (namelen
> DLM_LOCKID_NAME_MAX
) {
2240 mlog(ML_ERROR
, "Invalid name length!");
2243 if (deref
->node_idx
>= O2NM_MAX_NODES
) {
2244 mlog(ML_ERROR
, "Invalid node number: %u\n", node
);
2248 hash
= dlm_lockid_hash(name
, namelen
);
2250 spin_lock(&dlm
->spinlock
);
2251 res
= __dlm_lookup_lockres_full(dlm
, name
, namelen
, hash
);
2253 spin_unlock(&dlm
->spinlock
);
2254 mlog(ML_ERROR
, "%s:%.*s: bad lockres name\n",
2255 dlm
->name
, namelen
, name
);
2258 spin_unlock(&dlm
->spinlock
);
2260 spin_lock(&res
->spinlock
);
2261 if (res
->state
& DLM_LOCK_RES_SETREF_INPROG
)
2264 BUG_ON(res
->state
& DLM_LOCK_RES_DROPPING_REF
);
2265 if (test_bit(node
, res
->refmap
)) {
2266 dlm_lockres_clear_refmap_bit(dlm
, res
, node
);
2270 spin_unlock(&res
->spinlock
);
2274 dlm_lockres_calc_usage(dlm
, res
);
2276 mlog(ML_ERROR
, "%s:%.*s: node %u trying to drop ref "
2277 "but it is already dropped!\n", dlm
->name
,
2278 res
->lockname
.len
, res
->lockname
.name
, node
);
2279 dlm_print_one_lock_resource(res
);
2285 item
= kzalloc(sizeof(*item
), GFP_NOFS
);
2292 dlm_init_work_item(dlm
, item
, dlm_deref_lockres_worker
, NULL
);
2293 item
->u
.dl
.deref_res
= res
;
2294 item
->u
.dl
.deref_node
= node
;
2296 spin_lock(&dlm
->work_lock
);
2297 list_add_tail(&item
->list
, &dlm
->work_list
);
2298 spin_unlock(&dlm
->work_lock
);
2300 queue_work(dlm
->dlm_worker
, &dlm
->dispatched_work
);
2305 dlm_lockres_put(res
);
2311 static void dlm_deref_lockres_worker(struct dlm_work_item
*item
, void *data
)
2313 struct dlm_ctxt
*dlm
;
2314 struct dlm_lock_resource
*res
;
2319 res
= item
->u
.dl
.deref_res
;
2320 node
= item
->u
.dl
.deref_node
;
2322 spin_lock(&res
->spinlock
);
2323 BUG_ON(res
->state
& DLM_LOCK_RES_DROPPING_REF
);
2324 if (test_bit(node
, res
->refmap
)) {
2325 __dlm_wait_on_lockres_flags(res
, DLM_LOCK_RES_SETREF_INPROG
);
2326 dlm_lockres_clear_refmap_bit(dlm
, res
, node
);
2329 spin_unlock(&res
->spinlock
);
2332 mlog(0, "%s:%.*s node %u ref dropped in dispatch\n",
2333 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
, node
);
2334 dlm_lockres_calc_usage(dlm
, res
);
2336 mlog(ML_ERROR
, "%s:%.*s: node %u trying to drop ref "
2337 "but it is already dropped!\n", dlm
->name
,
2338 res
->lockname
.len
, res
->lockname
.name
, node
);
2339 dlm_print_one_lock_resource(res
);
2342 dlm_lockres_put(res
);
2346 * A migrateable resource is one that is :
2347 * 1. locally mastered, and,
2348 * 2. zero local locks, and,
2349 * 3. one or more non-local locks, or, one or more references
2350 * Returns 1 if yes, 0 if not.
2352 static int dlm_is_lockres_migrateable(struct dlm_ctxt
*dlm
,
2353 struct dlm_lock_resource
*res
)
2355 enum dlm_lockres_list idx
;
2356 int nonlocal
= 0, node_ref
;
2357 struct list_head
*queue
;
2358 struct dlm_lock
*lock
;
2361 assert_spin_locked(&res
->spinlock
);
2363 /* delay migration when the lockres is in MIGRATING state */
2364 if (res
->state
& DLM_LOCK_RES_MIGRATING
)
2367 if (res
->owner
!= dlm
->node_num
)
2370 for (idx
= DLM_GRANTED_LIST
; idx
<= DLM_BLOCKED_LIST
; idx
++) {
2371 queue
= dlm_list_idx_to_ptr(res
, idx
);
2372 list_for_each_entry(lock
, queue
, list
) {
2373 if (lock
->ml
.node
!= dlm
->node_num
) {
2377 cookie
= be64_to_cpu(lock
->ml
.cookie
);
2378 mlog(0, "%s: Not migrateable res %.*s, lock %u:%llu on "
2379 "%s list\n", dlm
->name
, res
->lockname
.len
,
2381 dlm_get_lock_cookie_node(cookie
),
2382 dlm_get_lock_cookie_seq(cookie
),
2383 dlm_list_in_text(idx
));
2389 node_ref
= find_next_bit(res
->refmap
, O2NM_MAX_NODES
, 0);
2390 if (node_ref
>= O2NM_MAX_NODES
)
2394 mlog(0, "%s: res %.*s, Migrateable\n", dlm
->name
, res
->lockname
.len
,
2395 res
->lockname
.name
);
2401 * DLM_MIGRATE_LOCKRES
2405 static int dlm_migrate_lockres(struct dlm_ctxt
*dlm
,
2406 struct dlm_lock_resource
*res
, u8 target
)
2408 struct dlm_master_list_entry
*mle
= NULL
;
2409 struct dlm_master_list_entry
*oldmle
= NULL
;
2410 struct dlm_migratable_lockres
*mres
= NULL
;
2413 unsigned int namelen
;
2420 BUG_ON(target
== O2NM_MAX_NODES
);
2422 name
= res
->lockname
.name
;
2423 namelen
= res
->lockname
.len
;
2425 mlog(0, "%s: Migrating %.*s to node %u\n", dlm
->name
, namelen
, name
,
2428 /* preallocate up front. if this fails, abort */
2430 mres
= (struct dlm_migratable_lockres
*) __get_free_page(GFP_NOFS
);
2436 mle
= kmem_cache_alloc(dlm_mle_cache
, GFP_NOFS
);
2444 * clear any existing master requests and
2445 * add the migration mle to the list
2447 spin_lock(&dlm
->spinlock
);
2448 spin_lock(&dlm
->master_lock
);
2449 ret
= dlm_add_migration_mle(dlm
, res
, mle
, &oldmle
, name
,
2450 namelen
, target
, dlm
->node_num
);
2451 spin_unlock(&dlm
->master_lock
);
2452 spin_unlock(&dlm
->spinlock
);
2454 if (ret
== -EEXIST
) {
2455 mlog(0, "another process is already migrating it\n");
2461 * set the MIGRATING flag and flush asts
2462 * if we fail after this we need to re-dirty the lockres
2464 if (dlm_mark_lockres_migrating(dlm
, res
, target
) < 0) {
2465 mlog(ML_ERROR
, "tried to migrate %.*s to %u, but "
2466 "the target went down.\n", res
->lockname
.len
,
2467 res
->lockname
.name
, target
);
2468 spin_lock(&res
->spinlock
);
2469 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
2471 spin_unlock(&res
->spinlock
);
2477 /* master is known, detach if not already detached */
2478 dlm_mle_detach_hb_events(dlm
, oldmle
);
2479 dlm_put_mle(oldmle
);
2484 dlm_mle_detach_hb_events(dlm
, mle
);
2487 kmem_cache_free(dlm_mle_cache
, mle
);
2494 * at this point, we have a migration target, an mle
2495 * in the master list, and the MIGRATING flag set on
2499 /* now that remote nodes are spinning on the MIGRATING flag,
2500 * ensure that all assert_master work is flushed. */
2501 flush_workqueue(dlm
->dlm_worker
);
2503 /* get an extra reference on the mle.
2504 * otherwise the assert_master from the new
2505 * master will destroy this.
2506 * also, make sure that all callers of dlm_get_mle
2507 * take both dlm->spinlock and dlm->master_lock */
2508 spin_lock(&dlm
->spinlock
);
2509 spin_lock(&dlm
->master_lock
);
2510 dlm_get_mle_inuse(mle
);
2511 spin_unlock(&dlm
->master_lock
);
2512 spin_unlock(&dlm
->spinlock
);
2514 /* notify new node and send all lock state */
2515 /* call send_one_lockres with migration flag.
2516 * this serves as notice to the target node that a
2517 * migration is starting. */
2518 ret
= dlm_send_one_lockres(dlm
, res
, mres
, target
,
2519 DLM_MRES_MIGRATION
);
2522 mlog(0, "migration to node %u failed with %d\n",
2524 /* migration failed, detach and clean up mle */
2525 dlm_mle_detach_hb_events(dlm
, mle
);
2527 dlm_put_mle_inuse(mle
);
2528 spin_lock(&res
->spinlock
);
2529 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
2531 spin_unlock(&res
->spinlock
);
2532 if (dlm_is_host_down(ret
))
2533 dlm_wait_for_node_death(dlm
, target
,
2534 DLM_NODE_DEATH_WAIT_MAX
);
2538 /* at this point, the target sends a message to all nodes,
2539 * (using dlm_do_migrate_request). this node is skipped since
2540 * we had to put an mle in the list to begin the process. this
2541 * node now waits for target to do an assert master. this node
2542 * will be the last one notified, ensuring that the migration
2543 * is complete everywhere. if the target dies while this is
2544 * going on, some nodes could potentially see the target as the
2545 * master, so it is important that my recovery finds the migration
2546 * mle and sets the master to UNKNOWN. */
2549 /* wait for new node to assert master */
2551 ret
= wait_event_interruptible_timeout(mle
->wq
,
2552 (atomic_read(&mle
->woken
) == 1),
2553 msecs_to_jiffies(5000));
2556 if (atomic_read(&mle
->woken
) == 1 ||
2557 res
->owner
== target
)
2560 mlog(0, "%s:%.*s: timed out during migration\n",
2561 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
);
2562 /* avoid hang during shutdown when migrating lockres
2563 * to a node which also goes down */
2564 if (dlm_is_node_dead(dlm
, target
)) {
2565 mlog(0, "%s:%.*s: expected migration "
2566 "target %u is no longer up, restarting\n",
2567 dlm
->name
, res
->lockname
.len
,
2568 res
->lockname
.name
, target
);
2570 /* migration failed, detach and clean up mle */
2571 dlm_mle_detach_hb_events(dlm
, mle
);
2573 dlm_put_mle_inuse(mle
);
2574 spin_lock(&res
->spinlock
);
2575 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
2577 spin_unlock(&res
->spinlock
);
2581 mlog(0, "%s:%.*s: caught signal during migration\n",
2582 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
);
2585 /* all done, set the owner, clear the flag */
2586 spin_lock(&res
->spinlock
);
2587 dlm_set_lockres_owner(dlm
, res
, target
);
2588 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
2589 dlm_remove_nonlocal_locks(dlm
, res
);
2590 spin_unlock(&res
->spinlock
);
2593 /* master is known, detach if not already detached */
2594 dlm_mle_detach_hb_events(dlm
, mle
);
2595 dlm_put_mle_inuse(mle
);
2598 dlm_lockres_calc_usage(dlm
, res
);
2601 /* re-dirty the lockres if we failed */
2603 dlm_kick_thread(dlm
, res
);
2605 /* wake up waiters if the MIGRATING flag got set
2606 * but migration failed */
2611 free_page((unsigned long)mres
);
2615 mlog(0, "%s: Migrating %.*s to %u, returns %d\n", dlm
->name
, namelen
,
2620 #define DLM_MIGRATION_RETRY_MS 100
2623 * Should be called only after beginning the domain leave process.
2624 * There should not be any remaining locks on nonlocal lock resources,
2625 * and there should be no local locks left on locally mastered resources.
2627 * Called with the dlm spinlock held, may drop it to do migration, but
2628 * will re-acquire before exit.
2630 * Returns: 1 if dlm->spinlock was dropped/retaken, 0 if never dropped
2632 int dlm_empty_lockres(struct dlm_ctxt
*dlm
, struct dlm_lock_resource
*res
)
2635 int lock_dropped
= 0;
2636 u8 target
= O2NM_MAX_NODES
;
2638 assert_spin_locked(&dlm
->spinlock
);
2640 spin_lock(&res
->spinlock
);
2641 if (dlm_is_lockres_migrateable(dlm
, res
))
2642 target
= dlm_pick_migration_target(dlm
, res
);
2643 spin_unlock(&res
->spinlock
);
2645 if (target
== O2NM_MAX_NODES
)
2648 /* Wheee! Migrate lockres here! Will sleep so drop spinlock. */
2649 spin_unlock(&dlm
->spinlock
);
2651 ret
= dlm_migrate_lockres(dlm
, res
, target
);
2653 mlog(0, "%s: res %.*s, Migrate to node %u failed with %d\n",
2654 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
,
2656 spin_lock(&dlm
->spinlock
);
2658 return lock_dropped
;
2661 int dlm_lock_basts_flushed(struct dlm_ctxt
*dlm
, struct dlm_lock
*lock
)
2664 spin_lock(&dlm
->ast_lock
);
2665 spin_lock(&lock
->spinlock
);
2666 ret
= (list_empty(&lock
->bast_list
) && !lock
->bast_pending
);
2667 spin_unlock(&lock
->spinlock
);
2668 spin_unlock(&dlm
->ast_lock
);
2672 static int dlm_migration_can_proceed(struct dlm_ctxt
*dlm
,
2673 struct dlm_lock_resource
*res
,
2677 spin_lock(&res
->spinlock
);
2678 can_proceed
= !!(res
->state
& DLM_LOCK_RES_MIGRATING
);
2679 spin_unlock(&res
->spinlock
);
2681 /* target has died, so make the caller break out of the
2682 * wait_event, but caller must recheck the domain_map */
2683 spin_lock(&dlm
->spinlock
);
2684 if (!test_bit(mig_target
, dlm
->domain_map
))
2686 spin_unlock(&dlm
->spinlock
);
2690 static int dlm_lockres_is_dirty(struct dlm_ctxt
*dlm
,
2691 struct dlm_lock_resource
*res
)
2694 spin_lock(&res
->spinlock
);
2695 ret
= !!(res
->state
& DLM_LOCK_RES_DIRTY
);
2696 spin_unlock(&res
->spinlock
);
2701 static int dlm_mark_lockres_migrating(struct dlm_ctxt
*dlm
,
2702 struct dlm_lock_resource
*res
,
2707 mlog(0, "dlm_mark_lockres_migrating: %.*s, from %u to %u\n",
2708 res
->lockname
.len
, res
->lockname
.name
, dlm
->node_num
,
2710 /* need to set MIGRATING flag on lockres. this is done by
2711 * ensuring that all asts have been flushed for this lockres. */
2712 spin_lock(&res
->spinlock
);
2713 BUG_ON(res
->migration_pending
);
2714 res
->migration_pending
= 1;
2715 /* strategy is to reserve an extra ast then release
2716 * it below, letting the release do all of the work */
2717 __dlm_lockres_reserve_ast(res
);
2718 spin_unlock(&res
->spinlock
);
2720 /* now flush all the pending asts */
2721 dlm_kick_thread(dlm
, res
);
2722 /* before waiting on DIRTY, block processes which may
2723 * try to dirty the lockres before MIGRATING is set */
2724 spin_lock(&res
->spinlock
);
2725 BUG_ON(res
->state
& DLM_LOCK_RES_BLOCK_DIRTY
);
2726 res
->state
|= DLM_LOCK_RES_BLOCK_DIRTY
;
2727 spin_unlock(&res
->spinlock
);
2728 /* now wait on any pending asts and the DIRTY state */
2729 wait_event(dlm
->ast_wq
, !dlm_lockres_is_dirty(dlm
, res
));
2730 dlm_lockres_release_ast(dlm
, res
);
2732 mlog(0, "about to wait on migration_wq, dirty=%s\n",
2733 res
->state
& DLM_LOCK_RES_DIRTY
? "yes" : "no");
2734 /* if the extra ref we just put was the final one, this
2735 * will pass thru immediately. otherwise, we need to wait
2736 * for the last ast to finish. */
2738 ret
= wait_event_interruptible_timeout(dlm
->migration_wq
,
2739 dlm_migration_can_proceed(dlm
, res
, target
),
2740 msecs_to_jiffies(1000));
2742 mlog(0, "woken again: migrating? %s, dead? %s\n",
2743 res
->state
& DLM_LOCK_RES_MIGRATING
? "yes":"no",
2744 test_bit(target
, dlm
->domain_map
) ? "no":"yes");
2746 mlog(0, "all is well: migrating? %s, dead? %s\n",
2747 res
->state
& DLM_LOCK_RES_MIGRATING
? "yes":"no",
2748 test_bit(target
, dlm
->domain_map
) ? "no":"yes");
2750 if (!dlm_migration_can_proceed(dlm
, res
, target
)) {
2751 mlog(0, "trying again...\n");
2756 /* did the target go down or die? */
2757 spin_lock(&dlm
->spinlock
);
2758 if (!test_bit(target
, dlm
->domain_map
)) {
2759 mlog(ML_ERROR
, "aha. migration target %u just went down\n",
2763 spin_unlock(&dlm
->spinlock
);
2766 * if target is down, we need to clear DLM_LOCK_RES_BLOCK_DIRTY for
2767 * another try; otherwise, we are sure the MIGRATING state is there,
2768 * drop the unneded state which blocked threads trying to DIRTY
2770 spin_lock(&res
->spinlock
);
2771 BUG_ON(!(res
->state
& DLM_LOCK_RES_BLOCK_DIRTY
));
2772 res
->state
&= ~DLM_LOCK_RES_BLOCK_DIRTY
;
2774 BUG_ON(!(res
->state
& DLM_LOCK_RES_MIGRATING
));
2775 spin_unlock(&res
->spinlock
);
2780 * o the DLM_LOCK_RES_MIGRATING flag is set if target not down
2781 * o there are no pending asts on this lockres
2782 * o all processes trying to reserve an ast on this
2783 * lockres must wait for the MIGRATING flag to clear
2788 /* last step in the migration process.
2789 * original master calls this to free all of the dlm_lock
2790 * structures that used to be for other nodes. */
2791 static void dlm_remove_nonlocal_locks(struct dlm_ctxt
*dlm
,
2792 struct dlm_lock_resource
*res
)
2794 struct list_head
*queue
= &res
->granted
;
2796 struct dlm_lock
*lock
, *next
;
2798 assert_spin_locked(&res
->spinlock
);
2800 BUG_ON(res
->owner
== dlm
->node_num
);
2802 for (i
=0; i
<3; i
++) {
2803 list_for_each_entry_safe(lock
, next
, queue
, list
) {
2804 if (lock
->ml
.node
!= dlm
->node_num
) {
2805 mlog(0, "putting lock for node %u\n",
2807 /* be extra careful */
2808 BUG_ON(!list_empty(&lock
->ast_list
));
2809 BUG_ON(!list_empty(&lock
->bast_list
));
2810 BUG_ON(lock
->ast_pending
);
2811 BUG_ON(lock
->bast_pending
);
2812 dlm_lockres_clear_refmap_bit(dlm
, res
,
2814 list_del_init(&lock
->list
);
2816 /* In a normal unlock, we would have added a
2817 * DLM_UNLOCK_FREE_LOCK action. Force it. */
2825 bit
= find_next_bit(res
->refmap
, O2NM_MAX_NODES
, bit
);
2826 if (bit
>= O2NM_MAX_NODES
)
2828 /* do not clear the local node reference, if there is a
2829 * process holding this, let it drop the ref itself */
2830 if (bit
!= dlm
->node_num
) {
2831 mlog(0, "%s:%.*s: node %u had a ref to this "
2832 "migrating lockres, clearing\n", dlm
->name
,
2833 res
->lockname
.len
, res
->lockname
.name
, bit
);
2834 dlm_lockres_clear_refmap_bit(dlm
, res
, bit
);
2841 * Pick a node to migrate the lock resource to. This function selects a
2842 * potential target based first on the locks and then on refmap. It skips
2843 * nodes that are in the process of exiting the domain.
2845 static u8
dlm_pick_migration_target(struct dlm_ctxt
*dlm
,
2846 struct dlm_lock_resource
*res
)
2848 enum dlm_lockres_list idx
;
2849 struct list_head
*queue
= &res
->granted
;
2850 struct dlm_lock
*lock
;
2852 u8 nodenum
= O2NM_MAX_NODES
;
2854 assert_spin_locked(&dlm
->spinlock
);
2855 assert_spin_locked(&res
->spinlock
);
2857 /* Go through all the locks */
2858 for (idx
= DLM_GRANTED_LIST
; idx
<= DLM_BLOCKED_LIST
; idx
++) {
2859 queue
= dlm_list_idx_to_ptr(res
, idx
);
2860 list_for_each_entry(lock
, queue
, list
) {
2861 if (lock
->ml
.node
== dlm
->node_num
)
2863 if (test_bit(lock
->ml
.node
, dlm
->exit_domain_map
))
2865 nodenum
= lock
->ml
.node
;
2870 /* Go thru the refmap */
2873 noderef
= find_next_bit(res
->refmap
, O2NM_MAX_NODES
,
2875 if (noderef
>= O2NM_MAX_NODES
)
2877 if (noderef
== dlm
->node_num
)
2879 if (test_bit(noderef
, dlm
->exit_domain_map
))
2889 /* this is called by the new master once all lockres
2890 * data has been received */
2891 static int dlm_do_migrate_request(struct dlm_ctxt
*dlm
,
2892 struct dlm_lock_resource
*res
,
2893 u8 master
, u8 new_master
,
2894 struct dlm_node_iter
*iter
)
2896 struct dlm_migrate_request migrate
;
2897 int ret
, skip
, status
= 0;
2900 memset(&migrate
, 0, sizeof(migrate
));
2901 migrate
.namelen
= res
->lockname
.len
;
2902 memcpy(migrate
.name
, res
->lockname
.name
, migrate
.namelen
);
2903 migrate
.new_master
= new_master
;
2904 migrate
.master
= master
;
2908 /* send message to all nodes, except the master and myself */
2909 while ((nodenum
= dlm_node_iter_next(iter
)) >= 0) {
2910 if (nodenum
== master
||
2911 nodenum
== new_master
)
2914 /* We could race exit domain. If exited, skip. */
2915 spin_lock(&dlm
->spinlock
);
2916 skip
= (!test_bit(nodenum
, dlm
->domain_map
));
2917 spin_unlock(&dlm
->spinlock
);
2919 clear_bit(nodenum
, iter
->node_map
);
2923 ret
= o2net_send_message(DLM_MIGRATE_REQUEST_MSG
, dlm
->key
,
2924 &migrate
, sizeof(migrate
), nodenum
,
2927 mlog(ML_ERROR
, "%s: res %.*s, Error %d send "
2928 "MIGRATE_REQUEST to node %u\n", dlm
->name
,
2929 migrate
.namelen
, migrate
.name
, ret
, nodenum
);
2930 if (!dlm_is_host_down(ret
)) {
2931 mlog(ML_ERROR
, "unhandled error=%d!\n", ret
);
2934 clear_bit(nodenum
, iter
->node_map
);
2936 } else if (status
< 0) {
2937 mlog(0, "migrate request (node %u) returned %d!\n",
2940 } else if (status
== DLM_MIGRATE_RESPONSE_MASTERY_REF
) {
2941 /* during the migration request we short-circuited
2942 * the mastery of the lockres. make sure we have
2943 * a mastery ref for nodenum */
2944 mlog(0, "%s:%.*s: need ref for node %u\n",
2945 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
,
2947 spin_lock(&res
->spinlock
);
2948 dlm_lockres_set_refmap_bit(dlm
, res
, nodenum
);
2949 spin_unlock(&res
->spinlock
);
2956 mlog(0, "returning ret=%d\n", ret
);
2961 /* if there is an existing mle for this lockres, we now know who the master is.
2962 * (the one who sent us *this* message) we can clear it up right away.
2963 * since the process that put the mle on the list still has a reference to it,
2964 * we can unhash it now, set the master and wake the process. as a result,
2965 * we will have no mle in the list to start with. now we can add an mle for
2966 * the migration and this should be the only one found for those scanning the
2968 int dlm_migrate_request_handler(struct o2net_msg
*msg
, u32 len
, void *data
,
2971 struct dlm_ctxt
*dlm
= data
;
2972 struct dlm_lock_resource
*res
= NULL
;
2973 struct dlm_migrate_request
*migrate
= (struct dlm_migrate_request
*) msg
->buf
;
2974 struct dlm_master_list_entry
*mle
= NULL
, *oldmle
= NULL
;
2976 unsigned int namelen
, hash
;
2982 name
= migrate
->name
;
2983 namelen
= migrate
->namelen
;
2984 hash
= dlm_lockid_hash(name
, namelen
);
2986 /* preallocate.. if this fails, abort */
2987 mle
= kmem_cache_alloc(dlm_mle_cache
, GFP_NOFS
);
2994 /* check for pre-existing lock */
2995 spin_lock(&dlm
->spinlock
);
2996 res
= __dlm_lookup_lockres(dlm
, name
, namelen
, hash
);
2998 spin_lock(&res
->spinlock
);
2999 if (res
->state
& DLM_LOCK_RES_RECOVERING
) {
3000 /* if all is working ok, this can only mean that we got
3001 * a migrate request from a node that we now see as
3002 * dead. what can we do here? drop it to the floor? */
3003 spin_unlock(&res
->spinlock
);
3004 mlog(ML_ERROR
, "Got a migrate request, but the "
3005 "lockres is marked as recovering!");
3006 kmem_cache_free(dlm_mle_cache
, mle
);
3007 ret
= -EINVAL
; /* need a better solution */
3010 res
->state
|= DLM_LOCK_RES_MIGRATING
;
3011 spin_unlock(&res
->spinlock
);
3014 spin_lock(&dlm
->master_lock
);
3015 /* ignore status. only nonzero status would BUG. */
3016 ret
= dlm_add_migration_mle(dlm
, res
, mle
, &oldmle
,
3018 migrate
->new_master
,
3021 spin_unlock(&dlm
->master_lock
);
3023 spin_unlock(&dlm
->spinlock
);
3026 /* master is known, detach if not already detached */
3027 dlm_mle_detach_hb_events(dlm
, oldmle
);
3028 dlm_put_mle(oldmle
);
3032 dlm_lockres_put(res
);
3038 /* must be holding dlm->spinlock and dlm->master_lock
3039 * when adding a migration mle, we can clear any other mles
3040 * in the master list because we know with certainty that
3041 * the master is "master". so we remove any old mle from
3042 * the list after setting it's master field, and then add
3043 * the new migration mle. this way we can hold with the rule
3044 * of having only one mle for a given lock name at all times. */
3045 static int dlm_add_migration_mle(struct dlm_ctxt
*dlm
,
3046 struct dlm_lock_resource
*res
,
3047 struct dlm_master_list_entry
*mle
,
3048 struct dlm_master_list_entry
**oldmle
,
3049 const char *name
, unsigned int namelen
,
3050 u8 new_master
, u8 master
)
3057 assert_spin_locked(&dlm
->spinlock
);
3058 assert_spin_locked(&dlm
->master_lock
);
3060 /* caller is responsible for any ref taken here on oldmle */
3061 found
= dlm_find_mle(dlm
, oldmle
, (char *)name
, namelen
);
3063 struct dlm_master_list_entry
*tmp
= *oldmle
;
3064 spin_lock(&tmp
->spinlock
);
3065 if (tmp
->type
== DLM_MLE_MIGRATION
) {
3066 if (master
== dlm
->node_num
) {
3067 /* ah another process raced me to it */
3068 mlog(0, "tried to migrate %.*s, but some "
3069 "process beat me to it\n",
3073 /* bad. 2 NODES are trying to migrate! */
3074 mlog(ML_ERROR
, "migration error mle: "
3075 "master=%u new_master=%u // request: "
3076 "master=%u new_master=%u // "
3078 tmp
->master
, tmp
->new_master
,
3084 /* this is essentially what assert_master does */
3085 tmp
->master
= master
;
3086 atomic_set(&tmp
->woken
, 1);
3088 /* remove it so that only one mle will be found */
3089 __dlm_unlink_mle(dlm
, tmp
);
3090 __dlm_mle_detach_hb_events(dlm
, tmp
);
3091 ret
= DLM_MIGRATE_RESPONSE_MASTERY_REF
;
3092 mlog(0, "%s:%.*s: master=%u, newmaster=%u, "
3093 "telling master to get ref for cleared out mle "
3094 "during migration\n", dlm
->name
, namelen
, name
,
3095 master
, new_master
);
3097 spin_unlock(&tmp
->spinlock
);
3100 /* now add a migration mle to the tail of the list */
3101 dlm_init_mle(mle
, DLM_MLE_MIGRATION
, dlm
, res
, name
, namelen
);
3102 mle
->new_master
= new_master
;
3103 /* the new master will be sending an assert master for this.
3104 * at that point we will get the refmap reference */
3105 mle
->master
= master
;
3106 /* do this for consistency with other mle types */
3107 set_bit(new_master
, mle
->maybe_map
);
3108 __dlm_insert_mle(dlm
, mle
);
3114 * Sets the owner of the lockres, associated to the mle, to UNKNOWN
3116 static struct dlm_lock_resource
*dlm_reset_mleres_owner(struct dlm_ctxt
*dlm
,
3117 struct dlm_master_list_entry
*mle
)
3119 struct dlm_lock_resource
*res
;
3121 /* Find the lockres associated to the mle and set its owner to UNK */
3122 res
= __dlm_lookup_lockres(dlm
, mle
->mname
, mle
->mnamelen
,
3125 spin_unlock(&dlm
->master_lock
);
3127 /* move lockres onto recovery list */
3128 spin_lock(&res
->spinlock
);
3129 dlm_set_lockres_owner(dlm
, res
, DLM_LOCK_RES_OWNER_UNKNOWN
);
3130 dlm_move_lockres_to_recovery_list(dlm
, res
);
3131 spin_unlock(&res
->spinlock
);
3132 dlm_lockres_put(res
);
3134 /* about to get rid of mle, detach from heartbeat */
3135 __dlm_mle_detach_hb_events(dlm
, mle
);
3138 spin_lock(&dlm
->master_lock
);
3140 spin_unlock(&dlm
->master_lock
);
3146 static void dlm_clean_migration_mle(struct dlm_ctxt
*dlm
,
3147 struct dlm_master_list_entry
*mle
)
3149 __dlm_mle_detach_hb_events(dlm
, mle
);
3151 spin_lock(&mle
->spinlock
);
3152 __dlm_unlink_mle(dlm
, mle
);
3153 atomic_set(&mle
->woken
, 1);
3154 spin_unlock(&mle
->spinlock
);
3159 static void dlm_clean_block_mle(struct dlm_ctxt
*dlm
,
3160 struct dlm_master_list_entry
*mle
, u8 dead_node
)
3164 BUG_ON(mle
->type
!= DLM_MLE_BLOCK
);
3166 spin_lock(&mle
->spinlock
);
3167 bit
= find_next_bit(mle
->maybe_map
, O2NM_MAX_NODES
, 0);
3168 if (bit
!= dead_node
) {
3169 mlog(0, "mle found, but dead node %u would not have been "
3170 "master\n", dead_node
);
3171 spin_unlock(&mle
->spinlock
);
3173 /* Must drop the refcount by one since the assert_master will
3174 * never arrive. This may result in the mle being unlinked and
3175 * freed, but there may still be a process waiting in the
3176 * dlmlock path which is fine. */
3177 mlog(0, "node %u was expected master\n", dead_node
);
3178 atomic_set(&mle
->woken
, 1);
3179 spin_unlock(&mle
->spinlock
);
3182 /* Do not need events any longer, so detach from heartbeat */
3183 __dlm_mle_detach_hb_events(dlm
, mle
);
3188 void dlm_clean_master_list(struct dlm_ctxt
*dlm
, u8 dead_node
)
3190 struct dlm_master_list_entry
*mle
;
3191 struct dlm_lock_resource
*res
;
3192 struct hlist_head
*bucket
;
3193 struct hlist_node
*tmp
;
3196 mlog(0, "dlm=%s, dead node=%u\n", dlm
->name
, dead_node
);
3198 assert_spin_locked(&dlm
->spinlock
);
3200 /* clean the master list */
3201 spin_lock(&dlm
->master_lock
);
3202 for (i
= 0; i
< DLM_HASH_BUCKETS
; i
++) {
3203 bucket
= dlm_master_hash(dlm
, i
);
3204 hlist_for_each_entry_safe(mle
, tmp
, bucket
, master_hash_node
) {
3205 BUG_ON(mle
->type
!= DLM_MLE_BLOCK
&&
3206 mle
->type
!= DLM_MLE_MASTER
&&
3207 mle
->type
!= DLM_MLE_MIGRATION
);
3209 /* MASTER mles are initiated locally. The waiting
3210 * process will notice the node map change shortly.
3211 * Let that happen as normal. */
3212 if (mle
->type
== DLM_MLE_MASTER
)
3215 /* BLOCK mles are initiated by other nodes. Need to
3216 * clean up if the dead node would have been the
3218 if (mle
->type
== DLM_MLE_BLOCK
) {
3219 dlm_clean_block_mle(dlm
, mle
, dead_node
);
3223 /* Everything else is a MIGRATION mle */
3225 /* The rule for MIGRATION mles is that the master
3226 * becomes UNKNOWN if *either* the original or the new
3227 * master dies. All UNKNOWN lockres' are sent to
3228 * whichever node becomes the recovery master. The new
3229 * master is responsible for determining if there is
3230 * still a master for this lockres, or if he needs to
3231 * take over mastery. Either way, this node should
3232 * expect another message to resolve this. */
3234 if (mle
->master
!= dead_node
&&
3235 mle
->new_master
!= dead_node
)
3238 /* If we have reached this point, this mle needs to be
3239 * removed from the list and freed. */
3240 dlm_clean_migration_mle(dlm
, mle
);
3242 mlog(0, "%s: node %u died during migration from "
3243 "%u to %u!\n", dlm
->name
, dead_node
, mle
->master
,
3246 /* If we find a lockres associated with the mle, we've
3247 * hit this rare case that messes up our lock ordering.
3248 * If so, we need to drop the master lock so that we can
3249 * take the lockres lock, meaning that we will have to
3250 * restart from the head of list. */
3251 res
= dlm_reset_mleres_owner(dlm
, mle
);
3256 /* This may be the last reference */
3260 spin_unlock(&dlm
->master_lock
);
3263 int dlm_finish_migration(struct dlm_ctxt
*dlm
, struct dlm_lock_resource
*res
,
3266 struct dlm_node_iter iter
;
3269 spin_lock(&dlm
->spinlock
);
3270 dlm_node_iter_init(dlm
->domain_map
, &iter
);
3271 clear_bit(old_master
, iter
.node_map
);
3272 clear_bit(dlm
->node_num
, iter
.node_map
);
3273 spin_unlock(&dlm
->spinlock
);
3275 /* ownership of the lockres is changing. account for the
3276 * mastery reference here since old_master will briefly have
3277 * a reference after the migration completes */
3278 spin_lock(&res
->spinlock
);
3279 dlm_lockres_set_refmap_bit(dlm
, res
, old_master
);
3280 spin_unlock(&res
->spinlock
);
3282 mlog(0, "now time to do a migrate request to other nodes\n");
3283 ret
= dlm_do_migrate_request(dlm
, res
, old_master
,
3284 dlm
->node_num
, &iter
);
3290 mlog(0, "doing assert master of %.*s to all except the original node\n",
3291 res
->lockname
.len
, res
->lockname
.name
);
3292 /* this call now finishes out the nodemap
3293 * even if one or more nodes die */
3294 ret
= dlm_do_assert_master(dlm
, res
, iter
.node_map
,
3295 DLM_ASSERT_MASTER_FINISH_MIGRATION
);
3297 /* no longer need to retry. all living nodes contacted. */
3302 memset(iter
.node_map
, 0, sizeof(iter
.node_map
));
3303 set_bit(old_master
, iter
.node_map
);
3304 mlog(0, "doing assert master of %.*s back to %u\n",
3305 res
->lockname
.len
, res
->lockname
.name
, old_master
);
3306 ret
= dlm_do_assert_master(dlm
, res
, iter
.node_map
,
3307 DLM_ASSERT_MASTER_FINISH_MIGRATION
);
3309 mlog(0, "assert master to original master failed "
3311 /* the only nonzero status here would be because of
3312 * a dead original node. we're done. */
3316 /* all done, set the owner, clear the flag */
3317 spin_lock(&res
->spinlock
);
3318 dlm_set_lockres_owner(dlm
, res
, dlm
->node_num
);
3319 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
3320 spin_unlock(&res
->spinlock
);
3321 /* re-dirty it on the new master */
3322 dlm_kick_thread(dlm
, res
);
3329 * LOCKRES AST REFCOUNT
3330 * this is integral to migration
3333 /* for future intent to call an ast, reserve one ahead of time.
3334 * this should be called only after waiting on the lockres
3335 * with dlm_wait_on_lockres, and while still holding the
3336 * spinlock after the call. */
3337 void __dlm_lockres_reserve_ast(struct dlm_lock_resource
*res
)
3339 assert_spin_locked(&res
->spinlock
);
3340 if (res
->state
& DLM_LOCK_RES_MIGRATING
) {
3341 __dlm_print_one_lock_resource(res
);
3343 BUG_ON(res
->state
& DLM_LOCK_RES_MIGRATING
);
3345 atomic_inc(&res
->asts_reserved
);
3349 * used to drop the reserved ast, either because it went unused,
3350 * or because the ast/bast was actually called.
3352 * also, if there is a pending migration on this lockres,
3353 * and this was the last pending ast on the lockres,
3354 * atomically set the MIGRATING flag before we drop the lock.
3355 * this is how we ensure that migration can proceed with no
3356 * asts in progress. note that it is ok if the state of the
3357 * queues is such that a lock should be granted in the future
3358 * or that a bast should be fired, because the new master will
3359 * shuffle the lists on this lockres as soon as it is migrated.
3361 void dlm_lockres_release_ast(struct dlm_ctxt
*dlm
,
3362 struct dlm_lock_resource
*res
)
3364 if (!atomic_dec_and_lock(&res
->asts_reserved
, &res
->spinlock
))
3367 if (!res
->migration_pending
) {
3368 spin_unlock(&res
->spinlock
);
3372 BUG_ON(res
->state
& DLM_LOCK_RES_MIGRATING
);
3373 res
->migration_pending
= 0;
3374 res
->state
|= DLM_LOCK_RES_MIGRATING
;
3375 spin_unlock(&res
->spinlock
);
3377 wake_up(&dlm
->migration_wq
);
3380 void dlm_force_free_mles(struct dlm_ctxt
*dlm
)
3383 struct hlist_head
*bucket
;
3384 struct dlm_master_list_entry
*mle
;
3385 struct hlist_node
*tmp
;
3388 * We notified all other nodes that we are exiting the domain and
3389 * marked the dlm state to DLM_CTXT_LEAVING. If any mles are still
3390 * around we force free them and wake any processes that are waiting
3393 spin_lock(&dlm
->spinlock
);
3394 spin_lock(&dlm
->master_lock
);
3396 BUG_ON(dlm
->dlm_state
!= DLM_CTXT_LEAVING
);
3397 BUG_ON((find_next_bit(dlm
->domain_map
, O2NM_MAX_NODES
, 0) < O2NM_MAX_NODES
));
3399 for (i
= 0; i
< DLM_HASH_BUCKETS
; i
++) {
3400 bucket
= dlm_master_hash(dlm
, i
);
3401 hlist_for_each_entry_safe(mle
, tmp
, bucket
, master_hash_node
) {
3402 if (mle
->type
!= DLM_MLE_BLOCK
) {
3403 mlog(ML_ERROR
, "bad mle: %p\n", mle
);
3404 dlm_print_one_mle(mle
);
3406 atomic_set(&mle
->woken
, 1);
3409 __dlm_unlink_mle(dlm
, mle
);
3410 __dlm_mle_detach_hb_events(dlm
, mle
);
3414 spin_unlock(&dlm
->master_lock
);
3415 spin_unlock(&dlm
->spinlock
);