1 /* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
6 * standalone DLM module
8 * Copyright (C) 2004 Oracle. All rights reserved.
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public
12 * License as published by the Free Software Foundation; either
13 * version 2 of the License, or (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
20 * You should have received a copy of the GNU General Public
21 * License along with this program; if not, write to the
22 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 * Boston, MA 021110-1307, USA.
28 #include <linux/module.h>
30 #include <linux/types.h>
31 #include <linux/slab.h>
32 #include <linux/highmem.h>
33 #include <linux/init.h>
34 #include <linux/sysctl.h>
35 #include <linux/random.h>
36 #include <linux/blkdev.h>
37 #include <linux/socket.h>
38 #include <linux/inet.h>
39 #include <linux/spinlock.h>
40 #include <linux/delay.h>
43 #include "cluster/heartbeat.h"
44 #include "cluster/nodemanager.h"
45 #include "cluster/tcp.h"
48 #include "dlmcommon.h"
49 #include "dlmdomain.h"
52 #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_MASTER)
53 #include "cluster/masklog.h"
55 static void dlm_mle_node_down(struct dlm_ctxt
*dlm
,
56 struct dlm_master_list_entry
*mle
,
57 struct o2nm_node
*node
,
59 static void dlm_mle_node_up(struct dlm_ctxt
*dlm
,
60 struct dlm_master_list_entry
*mle
,
61 struct o2nm_node
*node
,
64 static void dlm_assert_master_worker(struct dlm_work_item
*item
, void *data
);
65 static int dlm_do_assert_master(struct dlm_ctxt
*dlm
,
66 struct dlm_lock_resource
*res
,
67 void *nodemap
, u32 flags
);
68 static void dlm_deref_lockres_worker(struct dlm_work_item
*item
, void *data
);
70 static inline int dlm_mle_equal(struct dlm_ctxt
*dlm
,
71 struct dlm_master_list_entry
*mle
,
78 if (namelen
!= mle
->mnamelen
||
79 memcmp(name
, mle
->mname
, namelen
) != 0)
85 static struct kmem_cache
*dlm_lockres_cache
= NULL
;
86 static struct kmem_cache
*dlm_lockname_cache
= NULL
;
87 static struct kmem_cache
*dlm_mle_cache
= NULL
;
89 static void dlm_mle_release(struct kref
*kref
);
90 static void dlm_init_mle(struct dlm_master_list_entry
*mle
,
91 enum dlm_mle_type type
,
93 struct dlm_lock_resource
*res
,
95 unsigned int namelen
);
96 static void dlm_put_mle(struct dlm_master_list_entry
*mle
);
97 static void __dlm_put_mle(struct dlm_master_list_entry
*mle
);
98 static int dlm_find_mle(struct dlm_ctxt
*dlm
,
99 struct dlm_master_list_entry
**mle
,
100 char *name
, unsigned int namelen
);
102 static int dlm_do_master_request(struct dlm_lock_resource
*res
,
103 struct dlm_master_list_entry
*mle
, int to
);
106 static int dlm_wait_for_lock_mastery(struct dlm_ctxt
*dlm
,
107 struct dlm_lock_resource
*res
,
108 struct dlm_master_list_entry
*mle
,
110 static int dlm_restart_lock_mastery(struct dlm_ctxt
*dlm
,
111 struct dlm_lock_resource
*res
,
112 struct dlm_master_list_entry
*mle
,
114 static int dlm_add_migration_mle(struct dlm_ctxt
*dlm
,
115 struct dlm_lock_resource
*res
,
116 struct dlm_master_list_entry
*mle
,
117 struct dlm_master_list_entry
**oldmle
,
118 const char *name
, unsigned int namelen
,
119 u8 new_master
, u8 master
);
121 static u8
dlm_pick_migration_target(struct dlm_ctxt
*dlm
,
122 struct dlm_lock_resource
*res
);
123 static void dlm_remove_nonlocal_locks(struct dlm_ctxt
*dlm
,
124 struct dlm_lock_resource
*res
);
125 static int dlm_mark_lockres_migrating(struct dlm_ctxt
*dlm
,
126 struct dlm_lock_resource
*res
,
128 static int dlm_pre_master_reco_lockres(struct dlm_ctxt
*dlm
,
129 struct dlm_lock_resource
*res
);
132 int dlm_is_host_down(int errno
)
149 case -EINVAL
: /* if returned from our tcp code,
150 this means there is no socket */
158 * MASTER LIST FUNCTIONS
163 * regarding master list entries and heartbeat callbacks:
165 * in order to avoid sleeping and allocation that occurs in
166 * heartbeat, master list entries are simply attached to the
167 * dlm's established heartbeat callbacks. the mle is attached
168 * when it is created, and since the dlm->spinlock is held at
169 * that time, any heartbeat event will be properly discovered
170 * by the mle. the mle needs to be detached from the
171 * dlm->mle_hb_events list as soon as heartbeat events are no
172 * longer useful to the mle, and before the mle is freed.
174 * as a general rule, heartbeat events are no longer needed by
175 * the mle once an "answer" regarding the lock master has been
178 static inline void __dlm_mle_attach_hb_events(struct dlm_ctxt
*dlm
,
179 struct dlm_master_list_entry
*mle
)
181 assert_spin_locked(&dlm
->spinlock
);
183 list_add_tail(&mle
->hb_events
, &dlm
->mle_hb_events
);
187 static inline void __dlm_mle_detach_hb_events(struct dlm_ctxt
*dlm
,
188 struct dlm_master_list_entry
*mle
)
190 if (!list_empty(&mle
->hb_events
))
191 list_del_init(&mle
->hb_events
);
195 static inline void dlm_mle_detach_hb_events(struct dlm_ctxt
*dlm
,
196 struct dlm_master_list_entry
*mle
)
198 spin_lock(&dlm
->spinlock
);
199 __dlm_mle_detach_hb_events(dlm
, mle
);
200 spin_unlock(&dlm
->spinlock
);
203 static void dlm_get_mle_inuse(struct dlm_master_list_entry
*mle
)
205 struct dlm_ctxt
*dlm
;
208 assert_spin_locked(&dlm
->spinlock
);
209 assert_spin_locked(&dlm
->master_lock
);
211 kref_get(&mle
->mle_refs
);
214 static void dlm_put_mle_inuse(struct dlm_master_list_entry
*mle
)
216 struct dlm_ctxt
*dlm
;
219 spin_lock(&dlm
->spinlock
);
220 spin_lock(&dlm
->master_lock
);
223 spin_unlock(&dlm
->master_lock
);
224 spin_unlock(&dlm
->spinlock
);
228 /* remove from list and free */
229 static void __dlm_put_mle(struct dlm_master_list_entry
*mle
)
231 struct dlm_ctxt
*dlm
;
234 assert_spin_locked(&dlm
->spinlock
);
235 assert_spin_locked(&dlm
->master_lock
);
236 if (!atomic_read(&mle
->mle_refs
.refcount
)) {
237 /* this may or may not crash, but who cares.
239 mlog(ML_ERROR
, "bad mle: %p\n", mle
);
240 dlm_print_one_mle(mle
);
243 kref_put(&mle
->mle_refs
, dlm_mle_release
);
247 /* must not have any spinlocks coming in */
248 static void dlm_put_mle(struct dlm_master_list_entry
*mle
)
250 struct dlm_ctxt
*dlm
;
253 spin_lock(&dlm
->spinlock
);
254 spin_lock(&dlm
->master_lock
);
256 spin_unlock(&dlm
->master_lock
);
257 spin_unlock(&dlm
->spinlock
);
260 static inline void dlm_get_mle(struct dlm_master_list_entry
*mle
)
262 kref_get(&mle
->mle_refs
);
265 static void dlm_init_mle(struct dlm_master_list_entry
*mle
,
266 enum dlm_mle_type type
,
267 struct dlm_ctxt
*dlm
,
268 struct dlm_lock_resource
*res
,
270 unsigned int namelen
)
272 assert_spin_locked(&dlm
->spinlock
);
276 INIT_HLIST_NODE(&mle
->master_hash_node
);
277 INIT_LIST_HEAD(&mle
->hb_events
);
278 memset(mle
->maybe_map
, 0, sizeof(mle
->maybe_map
));
279 spin_lock_init(&mle
->spinlock
);
280 init_waitqueue_head(&mle
->wq
);
281 atomic_set(&mle
->woken
, 0);
282 kref_init(&mle
->mle_refs
);
283 memset(mle
->response_map
, 0, sizeof(mle
->response_map
));
284 mle
->master
= O2NM_MAX_NODES
;
285 mle
->new_master
= O2NM_MAX_NODES
;
288 BUG_ON(mle
->type
!= DLM_MLE_BLOCK
&&
289 mle
->type
!= DLM_MLE_MASTER
&&
290 mle
->type
!= DLM_MLE_MIGRATION
);
292 if (mle
->type
== DLM_MLE_MASTER
) {
295 memcpy(mle
->mname
, res
->lockname
.name
, res
->lockname
.len
);
296 mle
->mnamelen
= res
->lockname
.len
;
297 mle
->mnamehash
= res
->lockname
.hash
;
301 memcpy(mle
->mname
, name
, namelen
);
302 mle
->mnamelen
= namelen
;
303 mle
->mnamehash
= dlm_lockid_hash(name
, namelen
);
306 atomic_inc(&dlm
->mle_tot_count
[mle
->type
]);
307 atomic_inc(&dlm
->mle_cur_count
[mle
->type
]);
309 /* copy off the node_map and register hb callbacks on our copy */
310 memcpy(mle
->node_map
, dlm
->domain_map
, sizeof(mle
->node_map
));
311 memcpy(mle
->vote_map
, dlm
->domain_map
, sizeof(mle
->vote_map
));
312 clear_bit(dlm
->node_num
, mle
->vote_map
);
313 clear_bit(dlm
->node_num
, mle
->node_map
);
315 /* attach the mle to the domain node up/down events */
316 __dlm_mle_attach_hb_events(dlm
, mle
);
319 void __dlm_unlink_mle(struct dlm_ctxt
*dlm
, struct dlm_master_list_entry
*mle
)
321 assert_spin_locked(&dlm
->spinlock
);
322 assert_spin_locked(&dlm
->master_lock
);
324 if (!hlist_unhashed(&mle
->master_hash_node
))
325 hlist_del_init(&mle
->master_hash_node
);
328 void __dlm_insert_mle(struct dlm_ctxt
*dlm
, struct dlm_master_list_entry
*mle
)
330 struct hlist_head
*bucket
;
332 assert_spin_locked(&dlm
->master_lock
);
334 bucket
= dlm_master_hash(dlm
, mle
->mnamehash
);
335 hlist_add_head(&mle
->master_hash_node
, bucket
);
338 /* returns 1 if found, 0 if not */
339 static int dlm_find_mle(struct dlm_ctxt
*dlm
,
340 struct dlm_master_list_entry
**mle
,
341 char *name
, unsigned int namelen
)
343 struct dlm_master_list_entry
*tmpmle
;
344 struct hlist_head
*bucket
;
345 struct hlist_node
*list
;
348 assert_spin_locked(&dlm
->master_lock
);
350 hash
= dlm_lockid_hash(name
, namelen
);
351 bucket
= dlm_master_hash(dlm
, hash
);
352 hlist_for_each(list
, bucket
) {
353 tmpmle
= hlist_entry(list
, struct dlm_master_list_entry
,
355 if (!dlm_mle_equal(dlm
, tmpmle
, name
, namelen
))
364 void dlm_hb_event_notify_attached(struct dlm_ctxt
*dlm
, int idx
, int node_up
)
366 struct dlm_master_list_entry
*mle
;
368 assert_spin_locked(&dlm
->spinlock
);
370 list_for_each_entry(mle
, &dlm
->mle_hb_events
, hb_events
) {
372 dlm_mle_node_up(dlm
, mle
, NULL
, idx
);
374 dlm_mle_node_down(dlm
, mle
, NULL
, idx
);
378 static void dlm_mle_node_down(struct dlm_ctxt
*dlm
,
379 struct dlm_master_list_entry
*mle
,
380 struct o2nm_node
*node
, int idx
)
382 spin_lock(&mle
->spinlock
);
384 if (!test_bit(idx
, mle
->node_map
))
385 mlog(0, "node %u already removed from nodemap!\n", idx
);
387 clear_bit(idx
, mle
->node_map
);
389 spin_unlock(&mle
->spinlock
);
392 static void dlm_mle_node_up(struct dlm_ctxt
*dlm
,
393 struct dlm_master_list_entry
*mle
,
394 struct o2nm_node
*node
, int idx
)
396 spin_lock(&mle
->spinlock
);
398 if (test_bit(idx
, mle
->node_map
))
399 mlog(0, "node %u already in node map!\n", idx
);
401 set_bit(idx
, mle
->node_map
);
403 spin_unlock(&mle
->spinlock
);
407 int dlm_init_mle_cache(void)
409 dlm_mle_cache
= kmem_cache_create("o2dlm_mle",
410 sizeof(struct dlm_master_list_entry
),
411 0, SLAB_HWCACHE_ALIGN
,
413 if (dlm_mle_cache
== NULL
)
418 void dlm_destroy_mle_cache(void)
421 kmem_cache_destroy(dlm_mle_cache
);
424 static void dlm_mle_release(struct kref
*kref
)
426 struct dlm_master_list_entry
*mle
;
427 struct dlm_ctxt
*dlm
;
431 mle
= container_of(kref
, struct dlm_master_list_entry
, mle_refs
);
434 assert_spin_locked(&dlm
->spinlock
);
435 assert_spin_locked(&dlm
->master_lock
);
437 mlog(0, "Releasing mle for %.*s, type %d\n", mle
->mnamelen
, mle
->mname
,
440 /* remove from list if not already */
441 __dlm_unlink_mle(dlm
, mle
);
443 /* detach the mle from the domain node up/down events */
444 __dlm_mle_detach_hb_events(dlm
, mle
);
446 atomic_dec(&dlm
->mle_cur_count
[mle
->type
]);
448 /* NOTE: kfree under spinlock here.
449 * if this is bad, we can move this to a freelist. */
450 kmem_cache_free(dlm_mle_cache
, mle
);
455 * LOCK RESOURCE FUNCTIONS
458 int dlm_init_master_caches(void)
460 dlm_lockres_cache
= kmem_cache_create("o2dlm_lockres",
461 sizeof(struct dlm_lock_resource
),
462 0, SLAB_HWCACHE_ALIGN
, NULL
);
463 if (!dlm_lockres_cache
)
466 dlm_lockname_cache
= kmem_cache_create("o2dlm_lockname",
467 DLM_LOCKID_NAME_MAX
, 0,
468 SLAB_HWCACHE_ALIGN
, NULL
);
469 if (!dlm_lockname_cache
)
474 dlm_destroy_master_caches();
478 void dlm_destroy_master_caches(void)
480 if (dlm_lockname_cache
)
481 kmem_cache_destroy(dlm_lockname_cache
);
483 if (dlm_lockres_cache
)
484 kmem_cache_destroy(dlm_lockres_cache
);
487 static void dlm_lockres_release(struct kref
*kref
)
489 struct dlm_lock_resource
*res
;
490 struct dlm_ctxt
*dlm
;
492 res
= container_of(kref
, struct dlm_lock_resource
, refs
);
495 /* This should not happen -- all lockres' have a name
496 * associated with them at init time. */
497 BUG_ON(!res
->lockname
.name
);
499 mlog(0, "destroying lockres %.*s\n", res
->lockname
.len
,
502 spin_lock(&dlm
->track_lock
);
503 if (!list_empty(&res
->tracking
))
504 list_del_init(&res
->tracking
);
506 mlog(ML_ERROR
, "Resource %.*s not on the Tracking list\n",
507 res
->lockname
.len
, res
->lockname
.name
);
508 dlm_print_one_lock_resource(res
);
510 spin_unlock(&dlm
->track_lock
);
512 atomic_dec(&dlm
->res_cur_count
);
516 if (!hlist_unhashed(&res
->hash_node
) ||
517 !list_empty(&res
->granted
) ||
518 !list_empty(&res
->converting
) ||
519 !list_empty(&res
->blocked
) ||
520 !list_empty(&res
->dirty
) ||
521 !list_empty(&res
->recovering
) ||
522 !list_empty(&res
->purge
)) {
524 "Going to BUG for resource %.*s."
525 " We're on a list! [%c%c%c%c%c%c%c]\n",
526 res
->lockname
.len
, res
->lockname
.name
,
527 !hlist_unhashed(&res
->hash_node
) ? 'H' : ' ',
528 !list_empty(&res
->granted
) ? 'G' : ' ',
529 !list_empty(&res
->converting
) ? 'C' : ' ',
530 !list_empty(&res
->blocked
) ? 'B' : ' ',
531 !list_empty(&res
->dirty
) ? 'D' : ' ',
532 !list_empty(&res
->recovering
) ? 'R' : ' ',
533 !list_empty(&res
->purge
) ? 'P' : ' ');
535 dlm_print_one_lock_resource(res
);
538 /* By the time we're ready to blow this guy away, we shouldn't
539 * be on any lists. */
540 BUG_ON(!hlist_unhashed(&res
->hash_node
));
541 BUG_ON(!list_empty(&res
->granted
));
542 BUG_ON(!list_empty(&res
->converting
));
543 BUG_ON(!list_empty(&res
->blocked
));
544 BUG_ON(!list_empty(&res
->dirty
));
545 BUG_ON(!list_empty(&res
->recovering
));
546 BUG_ON(!list_empty(&res
->purge
));
548 kmem_cache_free(dlm_lockname_cache
, (void *)res
->lockname
.name
);
550 kmem_cache_free(dlm_lockres_cache
, res
);
553 void dlm_lockres_put(struct dlm_lock_resource
*res
)
555 kref_put(&res
->refs
, dlm_lockres_release
);
558 static void dlm_init_lockres(struct dlm_ctxt
*dlm
,
559 struct dlm_lock_resource
*res
,
560 const char *name
, unsigned int namelen
)
564 /* If we memset here, we lose our reference to the kmalloc'd
565 * res->lockname.name, so be sure to init every field
568 qname
= (char *) res
->lockname
.name
;
569 memcpy(qname
, name
, namelen
);
571 res
->lockname
.len
= namelen
;
572 res
->lockname
.hash
= dlm_lockid_hash(name
, namelen
);
574 init_waitqueue_head(&res
->wq
);
575 spin_lock_init(&res
->spinlock
);
576 INIT_HLIST_NODE(&res
->hash_node
);
577 INIT_LIST_HEAD(&res
->granted
);
578 INIT_LIST_HEAD(&res
->converting
);
579 INIT_LIST_HEAD(&res
->blocked
);
580 INIT_LIST_HEAD(&res
->dirty
);
581 INIT_LIST_HEAD(&res
->recovering
);
582 INIT_LIST_HEAD(&res
->purge
);
583 INIT_LIST_HEAD(&res
->tracking
);
584 atomic_set(&res
->asts_reserved
, 0);
585 res
->migration_pending
= 0;
586 res
->inflight_locks
= 0;
588 /* put in dlm_lockres_release */
592 kref_init(&res
->refs
);
594 atomic_inc(&dlm
->res_tot_count
);
595 atomic_inc(&dlm
->res_cur_count
);
597 /* just for consistency */
598 spin_lock(&res
->spinlock
);
599 dlm_set_lockres_owner(dlm
, res
, DLM_LOCK_RES_OWNER_UNKNOWN
);
600 spin_unlock(&res
->spinlock
);
602 res
->state
= DLM_LOCK_RES_IN_PROGRESS
;
606 spin_lock(&dlm
->spinlock
);
607 list_add_tail(&res
->tracking
, &dlm
->tracking_list
);
608 spin_unlock(&dlm
->spinlock
);
610 memset(res
->lvb
, 0, DLM_LVB_LEN
);
611 memset(res
->refmap
, 0, sizeof(res
->refmap
));
614 struct dlm_lock_resource
*dlm_new_lockres(struct dlm_ctxt
*dlm
,
616 unsigned int namelen
)
618 struct dlm_lock_resource
*res
= NULL
;
620 res
= kmem_cache_zalloc(dlm_lockres_cache
, GFP_NOFS
);
624 res
->lockname
.name
= kmem_cache_zalloc(dlm_lockname_cache
, GFP_NOFS
);
625 if (!res
->lockname
.name
)
628 dlm_init_lockres(dlm
, res
, name
, namelen
);
632 if (res
&& res
->lockname
.name
)
633 kmem_cache_free(dlm_lockname_cache
, (void *)res
->lockname
.name
);
636 kmem_cache_free(dlm_lockres_cache
, res
);
640 void __dlm_lockres_grab_inflight_ref(struct dlm_ctxt
*dlm
,
641 struct dlm_lock_resource
*res
,
647 assert_spin_locked(&res
->spinlock
);
649 if (!test_bit(dlm
->node_num
, res
->refmap
)) {
650 BUG_ON(res
->inflight_locks
!= 0);
651 dlm_lockres_set_refmap_bit(dlm
->node_num
, res
);
653 res
->inflight_locks
++;
654 mlog(0, "%s:%.*s: inflight++: now %u\n",
655 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
,
656 res
->inflight_locks
);
659 void __dlm_lockres_drop_inflight_ref(struct dlm_ctxt
*dlm
,
660 struct dlm_lock_resource
*res
,
664 assert_spin_locked(&res
->spinlock
);
666 BUG_ON(res
->inflight_locks
== 0);
667 res
->inflight_locks
--;
668 mlog(0, "%s:%.*s: inflight--: now %u\n",
669 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
,
670 res
->inflight_locks
);
671 if (res
->inflight_locks
== 0)
672 dlm_lockres_clear_refmap_bit(dlm
->node_num
, res
);
677 * lookup a lock resource by name.
678 * may already exist in the hashtable.
679 * lockid is null terminated
681 * if not, allocate enough for the lockres and for
682 * the temporary structure used in doing the mastering.
684 * also, do a lookup in the dlm->master_list to see
685 * if another node has begun mastering the same lock.
686 * if so, there should be a block entry in there
687 * for this name, and we should *not* attempt to master
688 * the lock here. need to wait around for that node
689 * to assert_master (or die).
692 struct dlm_lock_resource
* dlm_get_lock_resource(struct dlm_ctxt
*dlm
,
697 struct dlm_lock_resource
*tmpres
=NULL
, *res
=NULL
;
698 struct dlm_master_list_entry
*mle
= NULL
;
699 struct dlm_master_list_entry
*alloc_mle
= NULL
;
702 struct dlm_node_iter iter
;
705 int bit
, wait_on_recovery
= 0;
706 int drop_inflight_if_nonlocal
= 0;
710 hash
= dlm_lockid_hash(lockid
, namelen
);
712 mlog(0, "get lockres %s (len %d)\n", lockid
, namelen
);
715 spin_lock(&dlm
->spinlock
);
716 tmpres
= __dlm_lookup_lockres_full(dlm
, lockid
, namelen
, hash
);
718 int dropping_ref
= 0;
720 spin_unlock(&dlm
->spinlock
);
722 spin_lock(&tmpres
->spinlock
);
723 /* We wait for the other thread that is mastering the resource */
724 if (tmpres
->owner
== DLM_LOCK_RES_OWNER_UNKNOWN
) {
725 __dlm_wait_on_lockres(tmpres
);
726 BUG_ON(tmpres
->owner
== DLM_LOCK_RES_OWNER_UNKNOWN
);
729 if (tmpres
->owner
== dlm
->node_num
) {
730 BUG_ON(tmpres
->state
& DLM_LOCK_RES_DROPPING_REF
);
731 dlm_lockres_grab_inflight_ref(dlm
, tmpres
);
732 } else if (tmpres
->state
& DLM_LOCK_RES_DROPPING_REF
)
734 spin_unlock(&tmpres
->spinlock
);
736 /* wait until done messaging the master, drop our ref to allow
737 * the lockres to be purged, start over. */
739 spin_lock(&tmpres
->spinlock
);
740 __dlm_wait_on_lockres_flags(tmpres
, DLM_LOCK_RES_DROPPING_REF
);
741 spin_unlock(&tmpres
->spinlock
);
742 dlm_lockres_put(tmpres
);
747 mlog(0, "found in hash!\n");
749 dlm_lockres_put(res
);
755 spin_unlock(&dlm
->spinlock
);
756 mlog(0, "allocating a new resource\n");
757 /* nothing found and we need to allocate one. */
758 alloc_mle
= kmem_cache_alloc(dlm_mle_cache
, GFP_NOFS
);
761 res
= dlm_new_lockres(dlm
, lockid
, namelen
);
767 mlog(0, "no lockres found, allocated our own: %p\n", res
);
769 if (flags
& LKM_LOCAL
) {
770 /* caller knows it's safe to assume it's not mastered elsewhere
771 * DONE! return right away */
772 spin_lock(&res
->spinlock
);
773 dlm_change_lockres_owner(dlm
, res
, dlm
->node_num
);
774 __dlm_insert_lockres(dlm
, res
);
775 dlm_lockres_grab_inflight_ref(dlm
, res
);
776 spin_unlock(&res
->spinlock
);
777 spin_unlock(&dlm
->spinlock
);
778 /* lockres still marked IN_PROGRESS */
782 /* check master list to see if another node has started mastering it */
783 spin_lock(&dlm
->master_lock
);
785 /* if we found a block, wait for lock to be mastered by another node */
786 blocked
= dlm_find_mle(dlm
, &mle
, (char *)lockid
, namelen
);
789 if (mle
->type
== DLM_MLE_MASTER
) {
790 mlog(ML_ERROR
, "master entry for nonexistent lock!\n");
793 mig
= (mle
->type
== DLM_MLE_MIGRATION
);
794 /* if there is a migration in progress, let the migration
795 * finish before continuing. we can wait for the absence
796 * of the MIGRATION mle: either the migrate finished or
797 * one of the nodes died and the mle was cleaned up.
798 * if there is a BLOCK here, but it already has a master
799 * set, we are too late. the master does not have a ref
800 * for us in the refmap. detach the mle and drop it.
801 * either way, go back to the top and start over. */
802 if (mig
|| mle
->master
!= O2NM_MAX_NODES
) {
803 BUG_ON(mig
&& mle
->master
== dlm
->node_num
);
804 /* we arrived too late. the master does not
805 * have a ref for us. retry. */
806 mlog(0, "%s:%.*s: late on %s\n",
807 dlm
->name
, namelen
, lockid
,
808 mig
? "MIGRATION" : "BLOCK");
809 spin_unlock(&dlm
->master_lock
);
810 spin_unlock(&dlm
->spinlock
);
812 /* master is known, detach */
814 dlm_mle_detach_hb_events(dlm
, mle
);
817 /* this is lame, but we cant wait on either
818 * the mle or lockres waitqueue here */
824 /* go ahead and try to master lock on this node */
826 /* make sure this does not get freed below */
828 dlm_init_mle(mle
, DLM_MLE_MASTER
, dlm
, res
, NULL
, 0);
829 set_bit(dlm
->node_num
, mle
->maybe_map
);
830 __dlm_insert_mle(dlm
, mle
);
832 /* still holding the dlm spinlock, check the recovery map
833 * to see if there are any nodes that still need to be
834 * considered. these will not appear in the mle nodemap
835 * but they might own this lockres. wait on them. */
836 bit
= find_next_bit(dlm
->recovery_map
, O2NM_MAX_NODES
, 0);
837 if (bit
< O2NM_MAX_NODES
) {
838 mlog(ML_NOTICE
, "%s:%.*s: at least one node (%d) to "
839 "recover before lock mastery can begin\n",
840 dlm
->name
, namelen
, (char *)lockid
, bit
);
841 wait_on_recovery
= 1;
845 /* at this point there is either a DLM_MLE_BLOCK or a
846 * DLM_MLE_MASTER on the master list, so it's safe to add the
847 * lockres to the hashtable. anyone who finds the lock will
848 * still have to wait on the IN_PROGRESS. */
850 /* finally add the lockres to its hash bucket */
851 __dlm_insert_lockres(dlm
, res
);
852 /* since this lockres is new it doesnt not require the spinlock */
853 dlm_lockres_grab_inflight_ref_new(dlm
, res
);
855 /* if this node does not become the master make sure to drop
856 * this inflight reference below */
857 drop_inflight_if_nonlocal
= 1;
859 /* get an extra ref on the mle in case this is a BLOCK
860 * if so, the creator of the BLOCK may try to put the last
861 * ref at this time in the assert master handler, so we
862 * need an extra one to keep from a bad ptr deref. */
863 dlm_get_mle_inuse(mle
);
864 spin_unlock(&dlm
->master_lock
);
865 spin_unlock(&dlm
->spinlock
);
868 while (wait_on_recovery
) {
869 /* any cluster changes that occurred after dropping the
870 * dlm spinlock would be detectable be a change on the mle,
871 * so we only need to clear out the recovery map once. */
872 if (dlm_is_recovery_lock(lockid
, namelen
)) {
873 mlog(ML_NOTICE
, "%s: recovery map is not empty, but "
874 "must master $RECOVERY lock now\n", dlm
->name
);
875 if (!dlm_pre_master_reco_lockres(dlm
, res
))
876 wait_on_recovery
= 0;
878 mlog(0, "%s: waiting 500ms for heartbeat state "
879 "change\n", dlm
->name
);
885 dlm_kick_recovery_thread(dlm
);
887 dlm_wait_for_recovery(dlm
);
889 spin_lock(&dlm
->spinlock
);
890 bit
= find_next_bit(dlm
->recovery_map
, O2NM_MAX_NODES
, 0);
891 if (bit
< O2NM_MAX_NODES
) {
892 mlog(ML_NOTICE
, "%s:%.*s: at least one node (%d) to "
893 "recover before lock mastery can begin\n",
894 dlm
->name
, namelen
, (char *)lockid
, bit
);
895 wait_on_recovery
= 1;
897 wait_on_recovery
= 0;
898 spin_unlock(&dlm
->spinlock
);
900 if (wait_on_recovery
)
901 dlm_wait_for_node_recovery(dlm
, bit
, 10000);
904 /* must wait for lock to be mastered elsewhere */
909 dlm_node_iter_init(mle
->vote_map
, &iter
);
910 while ((nodenum
= dlm_node_iter_next(&iter
)) >= 0) {
911 ret
= dlm_do_master_request(res
, mle
, nodenum
);
914 if (mle
->master
!= O2NM_MAX_NODES
) {
915 /* found a master ! */
916 if (mle
->master
<= nodenum
)
918 /* if our master request has not reached the master
919 * yet, keep going until it does. this is how the
920 * master will know that asserts are needed back to
921 * the lower nodes. */
922 mlog(0, "%s:%.*s: requests only up to %u but master "
923 "is %u, keep going\n", dlm
->name
, namelen
,
924 lockid
, nodenum
, mle
->master
);
929 /* keep going until the response map includes all nodes */
930 ret
= dlm_wait_for_lock_mastery(dlm
, res
, mle
, &blocked
);
932 wait_on_recovery
= 1;
933 mlog(0, "%s:%.*s: node map changed, redo the "
934 "master request now, blocked=%d\n",
935 dlm
->name
, res
->lockname
.len
,
936 res
->lockname
.name
, blocked
);
938 mlog(ML_ERROR
, "%s:%.*s: spinning on "
939 "dlm_wait_for_lock_mastery, blocked=%d\n",
940 dlm
->name
, res
->lockname
.len
,
941 res
->lockname
.name
, blocked
);
942 dlm_print_one_lock_resource(res
);
943 dlm_print_one_mle(mle
);
949 mlog(0, "lockres mastered by %u\n", res
->owner
);
950 /* make sure we never continue without this */
951 BUG_ON(res
->owner
== O2NM_MAX_NODES
);
953 /* master is known, detach if not already detached */
954 dlm_mle_detach_hb_events(dlm
, mle
);
956 /* put the extra ref */
957 dlm_put_mle_inuse(mle
);
960 spin_lock(&res
->spinlock
);
961 if (res
->owner
!= dlm
->node_num
&& drop_inflight_if_nonlocal
)
962 dlm_lockres_drop_inflight_ref(dlm
, res
);
963 res
->state
&= ~DLM_LOCK_RES_IN_PROGRESS
;
964 spin_unlock(&res
->spinlock
);
968 /* need to free the unused mle */
970 kmem_cache_free(dlm_mle_cache
, alloc_mle
);
976 #define DLM_MASTERY_TIMEOUT_MS 5000
978 static int dlm_wait_for_lock_mastery(struct dlm_ctxt
*dlm
,
979 struct dlm_lock_resource
*res
,
980 struct dlm_master_list_entry
*mle
,
985 int map_changed
, voting_done
;
992 /* check if another node has already become the owner */
993 spin_lock(&res
->spinlock
);
994 if (res
->owner
!= DLM_LOCK_RES_OWNER_UNKNOWN
) {
995 mlog(0, "%s:%.*s: owner is suddenly %u\n", dlm
->name
,
996 res
->lockname
.len
, res
->lockname
.name
, res
->owner
);
997 spin_unlock(&res
->spinlock
);
998 /* this will cause the master to re-assert across
999 * the whole cluster, freeing up mles */
1000 if (res
->owner
!= dlm
->node_num
) {
1001 ret
= dlm_do_master_request(res
, mle
, res
->owner
);
1003 /* give recovery a chance to run */
1004 mlog(ML_ERROR
, "link to %u went down?: %d\n", res
->owner
, ret
);
1012 spin_unlock(&res
->spinlock
);
1014 spin_lock(&mle
->spinlock
);
1016 map_changed
= (memcmp(mle
->vote_map
, mle
->node_map
,
1017 sizeof(mle
->vote_map
)) != 0);
1018 voting_done
= (memcmp(mle
->vote_map
, mle
->response_map
,
1019 sizeof(mle
->vote_map
)) == 0);
1021 /* restart if we hit any errors */
1024 mlog(0, "%s: %.*s: node map changed, restarting\n",
1025 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
);
1026 ret
= dlm_restart_lock_mastery(dlm
, res
, mle
, *blocked
);
1027 b
= (mle
->type
== DLM_MLE_BLOCK
);
1028 if ((*blocked
&& !b
) || (!*blocked
&& b
)) {
1029 mlog(0, "%s:%.*s: status change: old=%d new=%d\n",
1030 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
,
1034 spin_unlock(&mle
->spinlock
);
1039 mlog(0, "%s:%.*s: restart lock mastery succeeded, "
1040 "rechecking now\n", dlm
->name
, res
->lockname
.len
,
1041 res
->lockname
.name
);
1045 mlog(0, "map not changed and voting not done "
1046 "for %s:%.*s\n", dlm
->name
, res
->lockname
.len
,
1047 res
->lockname
.name
);
1051 if (m
!= O2NM_MAX_NODES
) {
1052 /* another node has done an assert!
1057 /* have all nodes responded? */
1058 if (voting_done
&& !*blocked
) {
1059 bit
= find_next_bit(mle
->maybe_map
, O2NM_MAX_NODES
, 0);
1060 if (dlm
->node_num
<= bit
) {
1061 /* my node number is lowest.
1062 * now tell other nodes that I am
1063 * mastering this. */
1064 mle
->master
= dlm
->node_num
;
1065 /* ref was grabbed in get_lock_resource
1066 * will be dropped in dlmlock_master */
1070 /* if voting is done, but we have not received
1071 * an assert master yet, we must sleep */
1075 spin_unlock(&mle
->spinlock
);
1077 /* sleep if we haven't finished voting yet */
1079 unsigned long timeo
= msecs_to_jiffies(DLM_MASTERY_TIMEOUT_MS
);
1082 if (atomic_read(&mle->mle_refs.refcount) < 2)
1083 mlog(ML_ERROR, "mle (%p) refs=%d, name=%.*s\n", mle,
1084 atomic_read(&mle->mle_refs.refcount),
1085 res->lockname.len, res->lockname.name);
1087 atomic_set(&mle
->woken
, 0);
1088 (void)wait_event_timeout(mle
->wq
,
1089 (atomic_read(&mle
->woken
) == 1),
1091 if (res
->owner
== O2NM_MAX_NODES
) {
1092 mlog(0, "%s:%.*s: waiting again\n", dlm
->name
,
1093 res
->lockname
.len
, res
->lockname
.name
);
1096 mlog(0, "done waiting, master is %u\n", res
->owner
);
1104 mlog(0, "about to master %.*s here, this=%u\n",
1105 res
->lockname
.len
, res
->lockname
.name
, m
);
1106 ret
= dlm_do_assert_master(dlm
, res
, mle
->vote_map
, 0);
1108 /* This is a failure in the network path,
1109 * not in the response to the assert_master
1110 * (any nonzero response is a BUG on this node).
1111 * Most likely a socket just got disconnected
1112 * due to node death. */
1115 /* no longer need to restart lock mastery.
1116 * all living nodes have been contacted. */
1120 /* set the lockres owner */
1121 spin_lock(&res
->spinlock
);
1122 /* mastery reference obtained either during
1123 * assert_master_handler or in get_lock_resource */
1124 dlm_change_lockres_owner(dlm
, res
, m
);
1125 spin_unlock(&res
->spinlock
);
1131 struct dlm_bitmap_diff_iter
1134 unsigned long *orig_bm
;
1135 unsigned long *cur_bm
;
1136 unsigned long diff_bm
[BITS_TO_LONGS(O2NM_MAX_NODES
)];
1139 enum dlm_node_state_change
1146 static void dlm_bitmap_diff_iter_init(struct dlm_bitmap_diff_iter
*iter
,
1147 unsigned long *orig_bm
,
1148 unsigned long *cur_bm
)
1150 unsigned long p1
, p2
;
1154 iter
->orig_bm
= orig_bm
;
1155 iter
->cur_bm
= cur_bm
;
1157 for (i
= 0; i
< BITS_TO_LONGS(O2NM_MAX_NODES
); i
++) {
1158 p1
= *(iter
->orig_bm
+ i
);
1159 p2
= *(iter
->cur_bm
+ i
);
1160 iter
->diff_bm
[i
] = (p1
& ~p2
) | (p2
& ~p1
);
1164 static int dlm_bitmap_diff_iter_next(struct dlm_bitmap_diff_iter
*iter
,
1165 enum dlm_node_state_change
*state
)
1169 if (iter
->curnode
>= O2NM_MAX_NODES
)
1172 bit
= find_next_bit(iter
->diff_bm
, O2NM_MAX_NODES
,
1174 if (bit
>= O2NM_MAX_NODES
) {
1175 iter
->curnode
= O2NM_MAX_NODES
;
1179 /* if it was there in the original then this node died */
1180 if (test_bit(bit
, iter
->orig_bm
))
1185 iter
->curnode
= bit
;
1190 static int dlm_restart_lock_mastery(struct dlm_ctxt
*dlm
,
1191 struct dlm_lock_resource
*res
,
1192 struct dlm_master_list_entry
*mle
,
1195 struct dlm_bitmap_diff_iter bdi
;
1196 enum dlm_node_state_change sc
;
1200 mlog(0, "something happened such that the "
1201 "master process may need to be restarted!\n");
1203 assert_spin_locked(&mle
->spinlock
);
1205 dlm_bitmap_diff_iter_init(&bdi
, mle
->vote_map
, mle
->node_map
);
1206 node
= dlm_bitmap_diff_iter_next(&bdi
, &sc
);
1208 if (sc
== NODE_UP
) {
1209 /* a node came up. clear any old vote from
1210 * the response map and set it in the vote map
1211 * then restart the mastery. */
1212 mlog(ML_NOTICE
, "node %d up while restarting\n", node
);
1214 /* redo the master request, but only for the new node */
1215 mlog(0, "sending request to new node\n");
1216 clear_bit(node
, mle
->response_map
);
1217 set_bit(node
, mle
->vote_map
);
1219 mlog(ML_ERROR
, "node down! %d\n", node
);
1221 int lowest
= find_next_bit(mle
->maybe_map
,
1224 /* act like it was never there */
1225 clear_bit(node
, mle
->maybe_map
);
1227 if (node
== lowest
) {
1228 mlog(0, "expected master %u died"
1229 " while this node was blocked "
1230 "waiting on it!\n", node
);
1231 lowest
= find_next_bit(mle
->maybe_map
,
1234 if (lowest
< O2NM_MAX_NODES
) {
1235 mlog(0, "%s:%.*s:still "
1236 "blocked. waiting on %u "
1242 /* mle is an MLE_BLOCK, but
1243 * there is now nothing left to
1244 * block on. we need to return
1245 * all the way back out and try
1246 * again with an MLE_MASTER.
1247 * dlm_do_local_recovery_cleanup
1248 * has already run, so the mle
1250 mlog(0, "%s:%.*s: no "
1251 "longer blocking. try to "
1252 "master this here\n",
1255 res
->lockname
.name
);
1256 mle
->type
= DLM_MLE_MASTER
;
1262 /* now blank out everything, as if we had never
1263 * contacted anyone */
1264 memset(mle
->maybe_map
, 0, sizeof(mle
->maybe_map
));
1265 memset(mle
->response_map
, 0, sizeof(mle
->response_map
));
1266 /* reset the vote_map to the current node_map */
1267 memcpy(mle
->vote_map
, mle
->node_map
,
1268 sizeof(mle
->node_map
));
1269 /* put myself into the maybe map */
1270 if (mle
->type
!= DLM_MLE_BLOCK
)
1271 set_bit(dlm
->node_num
, mle
->maybe_map
);
1274 node
= dlm_bitmap_diff_iter_next(&bdi
, &sc
);
1281 * DLM_MASTER_REQUEST_MSG
1283 * returns: 0 on success,
1284 * -errno on a network error
1286 * on error, the caller should assume the target node is "dead"
1290 static int dlm_do_master_request(struct dlm_lock_resource
*res
,
1291 struct dlm_master_list_entry
*mle
, int to
)
1293 struct dlm_ctxt
*dlm
= mle
->dlm
;
1294 struct dlm_master_request request
;
1295 int ret
, response
=0, resend
;
1297 memset(&request
, 0, sizeof(request
));
1298 request
.node_idx
= dlm
->node_num
;
1300 BUG_ON(mle
->type
== DLM_MLE_MIGRATION
);
1302 request
.namelen
= (u8
)mle
->mnamelen
;
1303 memcpy(request
.name
, mle
->mname
, request
.namelen
);
1306 ret
= o2net_send_message(DLM_MASTER_REQUEST_MSG
, dlm
->key
, &request
,
1307 sizeof(request
), to
, &response
);
1309 if (ret
== -ESRCH
) {
1310 /* should never happen */
1311 mlog(ML_ERROR
, "TCP stack not ready!\n");
1313 } else if (ret
== -EINVAL
) {
1314 mlog(ML_ERROR
, "bad args passed to o2net!\n");
1316 } else if (ret
== -ENOMEM
) {
1317 mlog(ML_ERROR
, "out of memory while trying to send "
1318 "network message! retrying\n");
1319 /* this is totally crude */
1322 } else if (!dlm_is_host_down(ret
)) {
1323 /* not a network error. bad. */
1325 mlog(ML_ERROR
, "unhandled error!");
1328 /* all other errors should be network errors,
1329 * and likely indicate node death */
1330 mlog(ML_ERROR
, "link to %d went down!\n", to
);
1336 spin_lock(&mle
->spinlock
);
1338 case DLM_MASTER_RESP_YES
:
1339 set_bit(to
, mle
->response_map
);
1340 mlog(0, "node %u is the master, response=YES\n", to
);
1341 mlog(0, "%s:%.*s: master node %u now knows I have a "
1342 "reference\n", dlm
->name
, res
->lockname
.len
,
1343 res
->lockname
.name
, to
);
1346 case DLM_MASTER_RESP_NO
:
1347 mlog(0, "node %u not master, response=NO\n", to
);
1348 set_bit(to
, mle
->response_map
);
1350 case DLM_MASTER_RESP_MAYBE
:
1351 mlog(0, "node %u not master, response=MAYBE\n", to
);
1352 set_bit(to
, mle
->response_map
);
1353 set_bit(to
, mle
->maybe_map
);
1355 case DLM_MASTER_RESP_ERROR
:
1356 mlog(0, "node %u hit an error, resending\n", to
);
1361 mlog(ML_ERROR
, "bad response! %u\n", response
);
1364 spin_unlock(&mle
->spinlock
);
1366 /* this is also totally crude */
1376 * locks that can be taken here:
1382 * if possible, TRIM THIS DOWN!!!
1384 int dlm_master_request_handler(struct o2net_msg
*msg
, u32 len
, void *data
,
1387 u8 response
= DLM_MASTER_RESP_MAYBE
;
1388 struct dlm_ctxt
*dlm
= data
;
1389 struct dlm_lock_resource
*res
= NULL
;
1390 struct dlm_master_request
*request
= (struct dlm_master_request
*) msg
->buf
;
1391 struct dlm_master_list_entry
*mle
= NULL
, *tmpmle
= NULL
;
1393 unsigned int namelen
, hash
;
1396 int dispatch_assert
= 0;
1399 return DLM_MASTER_RESP_NO
;
1401 if (!dlm_domain_fully_joined(dlm
)) {
1402 response
= DLM_MASTER_RESP_NO
;
1406 name
= request
->name
;
1407 namelen
= request
->namelen
;
1408 hash
= dlm_lockid_hash(name
, namelen
);
1410 if (namelen
> DLM_LOCKID_NAME_MAX
) {
1411 response
= DLM_IVBUFLEN
;
1416 spin_lock(&dlm
->spinlock
);
1417 res
= __dlm_lookup_lockres(dlm
, name
, namelen
, hash
);
1419 spin_unlock(&dlm
->spinlock
);
1421 /* take care of the easy cases up front */
1422 spin_lock(&res
->spinlock
);
1423 if (res
->state
& (DLM_LOCK_RES_RECOVERING
|
1424 DLM_LOCK_RES_MIGRATING
)) {
1425 spin_unlock(&res
->spinlock
);
1426 mlog(0, "returning DLM_MASTER_RESP_ERROR since res is "
1427 "being recovered/migrated\n");
1428 response
= DLM_MASTER_RESP_ERROR
;
1430 kmem_cache_free(dlm_mle_cache
, mle
);
1434 if (res
->owner
== dlm
->node_num
) {
1435 mlog(0, "%s:%.*s: setting bit %u in refmap\n",
1436 dlm
->name
, namelen
, name
, request
->node_idx
);
1437 dlm_lockres_set_refmap_bit(request
->node_idx
, res
);
1438 spin_unlock(&res
->spinlock
);
1439 response
= DLM_MASTER_RESP_YES
;
1441 kmem_cache_free(dlm_mle_cache
, mle
);
1443 /* this node is the owner.
1444 * there is some extra work that needs to
1445 * happen now. the requesting node has
1446 * caused all nodes up to this one to
1447 * create mles. this node now needs to
1448 * go back and clean those up. */
1449 dispatch_assert
= 1;
1451 } else if (res
->owner
!= DLM_LOCK_RES_OWNER_UNKNOWN
) {
1452 spin_unlock(&res
->spinlock
);
1453 // mlog(0, "node %u is the master\n", res->owner);
1454 response
= DLM_MASTER_RESP_NO
;
1456 kmem_cache_free(dlm_mle_cache
, mle
);
1460 /* ok, there is no owner. either this node is
1461 * being blocked, or it is actively trying to
1462 * master this lock. */
1463 if (!(res
->state
& DLM_LOCK_RES_IN_PROGRESS
)) {
1464 mlog(ML_ERROR
, "lock with no owner should be "
1469 // mlog(0, "lockres is in progress...\n");
1470 spin_lock(&dlm
->master_lock
);
1471 found
= dlm_find_mle(dlm
, &tmpmle
, name
, namelen
);
1473 mlog(ML_ERROR
, "no mle found for this lock!\n");
1477 spin_lock(&tmpmle
->spinlock
);
1478 if (tmpmle
->type
== DLM_MLE_BLOCK
) {
1479 // mlog(0, "this node is waiting for "
1480 // "lockres to be mastered\n");
1481 response
= DLM_MASTER_RESP_NO
;
1482 } else if (tmpmle
->type
== DLM_MLE_MIGRATION
) {
1483 mlog(0, "node %u is master, but trying to migrate to "
1484 "node %u.\n", tmpmle
->master
, tmpmle
->new_master
);
1485 if (tmpmle
->master
== dlm
->node_num
) {
1486 mlog(ML_ERROR
, "no owner on lockres, but this "
1487 "node is trying to migrate it to %u?!\n",
1488 tmpmle
->new_master
);
1491 /* the real master can respond on its own */
1492 response
= DLM_MASTER_RESP_NO
;
1494 } else if (tmpmle
->master
!= DLM_LOCK_RES_OWNER_UNKNOWN
) {
1496 if (tmpmle
->master
== dlm
->node_num
) {
1497 response
= DLM_MASTER_RESP_YES
;
1498 /* this node will be the owner.
1499 * go back and clean the mles on any
1501 dispatch_assert
= 1;
1502 dlm_lockres_set_refmap_bit(request
->node_idx
, res
);
1503 mlog(0, "%s:%.*s: setting bit %u in refmap\n",
1504 dlm
->name
, namelen
, name
,
1507 response
= DLM_MASTER_RESP_NO
;
1509 // mlog(0, "this node is attempting to "
1510 // "master lockres\n");
1511 response
= DLM_MASTER_RESP_MAYBE
;
1514 set_bit(request
->node_idx
, tmpmle
->maybe_map
);
1515 spin_unlock(&tmpmle
->spinlock
);
1517 spin_unlock(&dlm
->master_lock
);
1518 spin_unlock(&res
->spinlock
);
1520 /* keep the mle attached to heartbeat events */
1521 dlm_put_mle(tmpmle
);
1523 kmem_cache_free(dlm_mle_cache
, mle
);
1528 * lockres doesn't exist on this node
1529 * if there is an MLE_BLOCK, return NO
1530 * if there is an MLE_MASTER, return MAYBE
1531 * otherwise, add an MLE_BLOCK, return NO
1533 spin_lock(&dlm
->master_lock
);
1534 found
= dlm_find_mle(dlm
, &tmpmle
, name
, namelen
);
1536 /* this lockid has never been seen on this node yet */
1537 // mlog(0, "no mle found\n");
1539 spin_unlock(&dlm
->master_lock
);
1540 spin_unlock(&dlm
->spinlock
);
1542 mle
= kmem_cache_alloc(dlm_mle_cache
, GFP_NOFS
);
1544 response
= DLM_MASTER_RESP_ERROR
;
1545 mlog_errno(-ENOMEM
);
1551 // mlog(0, "this is second time thru, already allocated, "
1552 // "add the block.\n");
1553 dlm_init_mle(mle
, DLM_MLE_BLOCK
, dlm
, NULL
, name
, namelen
);
1554 set_bit(request
->node_idx
, mle
->maybe_map
);
1555 __dlm_insert_mle(dlm
, mle
);
1556 response
= DLM_MASTER_RESP_NO
;
1558 // mlog(0, "mle was found\n");
1560 spin_lock(&tmpmle
->spinlock
);
1561 if (tmpmle
->master
== dlm
->node_num
) {
1562 mlog(ML_ERROR
, "no lockres, but an mle with this node as master!\n");
1565 if (tmpmle
->type
== DLM_MLE_BLOCK
)
1566 response
= DLM_MASTER_RESP_NO
;
1567 else if (tmpmle
->type
== DLM_MLE_MIGRATION
) {
1568 mlog(0, "migration mle was found (%u->%u)\n",
1569 tmpmle
->master
, tmpmle
->new_master
);
1570 /* real master can respond on its own */
1571 response
= DLM_MASTER_RESP_NO
;
1573 response
= DLM_MASTER_RESP_MAYBE
;
1575 set_bit(request
->node_idx
, tmpmle
->maybe_map
);
1576 spin_unlock(&tmpmle
->spinlock
);
1578 spin_unlock(&dlm
->master_lock
);
1579 spin_unlock(&dlm
->spinlock
);
1582 /* keep the mle attached to heartbeat events */
1583 dlm_put_mle(tmpmle
);
1587 * __dlm_lookup_lockres() grabbed a reference to this lockres.
1588 * The reference is released by dlm_assert_master_worker() under
1589 * the call to dlm_dispatch_assert_master(). If
1590 * dlm_assert_master_worker() isn't called, we drop it here.
1592 if (dispatch_assert
) {
1593 if (response
!= DLM_MASTER_RESP_YES
)
1594 mlog(ML_ERROR
, "invalid response %d\n", response
);
1596 mlog(ML_ERROR
, "bad lockres while trying to assert!\n");
1599 mlog(0, "%u is the owner of %.*s, cleaning everyone else\n",
1600 dlm
->node_num
, res
->lockname
.len
, res
->lockname
.name
);
1601 ret
= dlm_dispatch_assert_master(dlm
, res
, 0, request
->node_idx
,
1602 DLM_ASSERT_MASTER_MLE_CLEANUP
);
1604 mlog(ML_ERROR
, "failed to dispatch assert master work\n");
1605 response
= DLM_MASTER_RESP_ERROR
;
1606 dlm_lockres_put(res
);
1610 dlm_lockres_put(res
);
1618 * DLM_ASSERT_MASTER_MSG
1623 * NOTE: this can be used for debugging
1624 * can periodically run all locks owned by this node
1625 * and re-assert across the cluster...
1627 static int dlm_do_assert_master(struct dlm_ctxt
*dlm
,
1628 struct dlm_lock_resource
*res
,
1629 void *nodemap
, u32 flags
)
1631 struct dlm_assert_master
assert;
1633 struct dlm_node_iter iter
;
1636 const char *lockname
= res
->lockname
.name
;
1637 unsigned int namelen
= res
->lockname
.len
;
1639 BUG_ON(namelen
> O2NM_MAX_NAME_LEN
);
1641 spin_lock(&res
->spinlock
);
1642 res
->state
|= DLM_LOCK_RES_SETREF_INPROG
;
1643 spin_unlock(&res
->spinlock
);
1648 /* note that if this nodemap is empty, it returns 0 */
1649 dlm_node_iter_init(nodemap
, &iter
);
1650 while ((to
= dlm_node_iter_next(&iter
)) >= 0) {
1652 struct dlm_master_list_entry
*mle
= NULL
;
1654 mlog(0, "sending assert master to %d (%.*s)\n", to
,
1656 memset(&assert, 0, sizeof(assert));
1657 assert.node_idx
= dlm
->node_num
;
1658 assert.namelen
= namelen
;
1659 memcpy(assert.name
, lockname
, namelen
);
1660 assert.flags
= cpu_to_be32(flags
);
1662 tmpret
= o2net_send_message(DLM_ASSERT_MASTER_MSG
, dlm
->key
,
1663 &assert, sizeof(assert), to
, &r
);
1665 mlog(ML_ERROR
, "Error %d when sending message %u (key "
1666 "0x%x) to node %u\n", tmpret
,
1667 DLM_ASSERT_MASTER_MSG
, dlm
->key
, to
);
1668 if (!dlm_is_host_down(tmpret
)) {
1669 mlog(ML_ERROR
, "unhandled error=%d!\n", tmpret
);
1672 /* a node died. finish out the rest of the nodes. */
1673 mlog(0, "link to %d went down!\n", to
);
1674 /* any nonzero status return will do */
1678 /* ok, something horribly messed. kill thyself. */
1679 mlog(ML_ERROR
,"during assert master of %.*s to %u, "
1680 "got %d.\n", namelen
, lockname
, to
, r
);
1681 spin_lock(&dlm
->spinlock
);
1682 spin_lock(&dlm
->master_lock
);
1683 if (dlm_find_mle(dlm
, &mle
, (char *)lockname
,
1685 dlm_print_one_mle(mle
);
1688 spin_unlock(&dlm
->master_lock
);
1689 spin_unlock(&dlm
->spinlock
);
1693 if (r
& DLM_ASSERT_RESPONSE_REASSERT
&&
1694 !(r
& DLM_ASSERT_RESPONSE_MASTERY_REF
)) {
1695 mlog(ML_ERROR
, "%.*s: very strange, "
1696 "master MLE but no lockres on %u\n",
1697 namelen
, lockname
, to
);
1700 if (r
& DLM_ASSERT_RESPONSE_REASSERT
) {
1701 mlog(0, "%.*s: node %u create mles on other "
1702 "nodes and requests a re-assert\n",
1703 namelen
, lockname
, to
);
1706 if (r
& DLM_ASSERT_RESPONSE_MASTERY_REF
) {
1707 mlog(0, "%.*s: node %u has a reference to this "
1708 "lockres, set the bit in the refmap\n",
1709 namelen
, lockname
, to
);
1710 spin_lock(&res
->spinlock
);
1711 dlm_lockres_set_refmap_bit(to
, res
);
1712 spin_unlock(&res
->spinlock
);
1719 spin_lock(&res
->spinlock
);
1720 res
->state
&= ~DLM_LOCK_RES_SETREF_INPROG
;
1721 spin_unlock(&res
->spinlock
);
1728 * locks that can be taken here:
1734 * if possible, TRIM THIS DOWN!!!
1736 int dlm_assert_master_handler(struct o2net_msg
*msg
, u32 len
, void *data
,
1739 struct dlm_ctxt
*dlm
= data
;
1740 struct dlm_master_list_entry
*mle
= NULL
;
1741 struct dlm_assert_master
*assert = (struct dlm_assert_master
*)msg
->buf
;
1742 struct dlm_lock_resource
*res
= NULL
;
1744 unsigned int namelen
, hash
;
1746 int master_request
= 0, have_lockres_ref
= 0;
1752 name
= assert->name
;
1753 namelen
= assert->namelen
;
1754 hash
= dlm_lockid_hash(name
, namelen
);
1755 flags
= be32_to_cpu(assert->flags
);
1757 if (namelen
> DLM_LOCKID_NAME_MAX
) {
1758 mlog(ML_ERROR
, "Invalid name length!");
1762 spin_lock(&dlm
->spinlock
);
1765 mlog(0, "assert_master with flags: %u\n", flags
);
1768 spin_lock(&dlm
->master_lock
);
1769 if (!dlm_find_mle(dlm
, &mle
, name
, namelen
)) {
1770 /* not an error, could be master just re-asserting */
1771 mlog(0, "just got an assert_master from %u, but no "
1772 "MLE for it! (%.*s)\n", assert->node_idx
,
1775 int bit
= find_next_bit (mle
->maybe_map
, O2NM_MAX_NODES
, 0);
1776 if (bit
>= O2NM_MAX_NODES
) {
1777 /* not necessarily an error, though less likely.
1778 * could be master just re-asserting. */
1779 mlog(0, "no bits set in the maybe_map, but %u "
1780 "is asserting! (%.*s)\n", assert->node_idx
,
1782 } else if (bit
!= assert->node_idx
) {
1783 if (flags
& DLM_ASSERT_MASTER_MLE_CLEANUP
) {
1784 mlog(0, "master %u was found, %u should "
1785 "back off\n", assert->node_idx
, bit
);
1787 /* with the fix for bug 569, a higher node
1788 * number winning the mastery will respond
1789 * YES to mastery requests, but this node
1790 * had no way of knowing. let it pass. */
1791 mlog(0, "%u is the lowest node, "
1792 "%u is asserting. (%.*s) %u must "
1793 "have begun after %u won.\n", bit
,
1794 assert->node_idx
, namelen
, name
, bit
,
1798 if (mle
->type
== DLM_MLE_MIGRATION
) {
1799 if (flags
& DLM_ASSERT_MASTER_MLE_CLEANUP
) {
1800 mlog(0, "%s:%.*s: got cleanup assert"
1801 " from %u for migration\n",
1802 dlm
->name
, namelen
, name
,
1804 } else if (!(flags
& DLM_ASSERT_MASTER_FINISH_MIGRATION
)) {
1805 mlog(0, "%s:%.*s: got unrelated assert"
1806 " from %u for migration, ignoring\n",
1807 dlm
->name
, namelen
, name
,
1810 spin_unlock(&dlm
->master_lock
);
1811 spin_unlock(&dlm
->spinlock
);
1816 spin_unlock(&dlm
->master_lock
);
1818 /* ok everything checks out with the MLE
1819 * now check to see if there is a lockres */
1820 res
= __dlm_lookup_lockres(dlm
, name
, namelen
, hash
);
1822 spin_lock(&res
->spinlock
);
1823 if (res
->state
& DLM_LOCK_RES_RECOVERING
) {
1824 mlog(ML_ERROR
, "%u asserting but %.*s is "
1825 "RECOVERING!\n", assert->node_idx
, namelen
, name
);
1829 if (res
->owner
!= DLM_LOCK_RES_OWNER_UNKNOWN
&&
1830 res
->owner
!= assert->node_idx
) {
1831 mlog(ML_ERROR
, "DIE! Mastery assert from %u, "
1832 "but current owner is %u! (%.*s)\n",
1833 assert->node_idx
, res
->owner
, namelen
,
1835 __dlm_print_one_lock_resource(res
);
1838 } else if (mle
->type
!= DLM_MLE_MIGRATION
) {
1839 if (res
->owner
!= DLM_LOCK_RES_OWNER_UNKNOWN
) {
1840 /* owner is just re-asserting */
1841 if (res
->owner
== assert->node_idx
) {
1842 mlog(0, "owner %u re-asserting on "
1843 "lock %.*s\n", assert->node_idx
,
1847 mlog(ML_ERROR
, "got assert_master from "
1848 "node %u, but %u is the owner! "
1849 "(%.*s)\n", assert->node_idx
,
1850 res
->owner
, namelen
, name
);
1853 if (!(res
->state
& DLM_LOCK_RES_IN_PROGRESS
)) {
1854 mlog(ML_ERROR
, "got assert from %u, but lock "
1855 "with no owner should be "
1856 "in-progress! (%.*s)\n",
1861 } else /* mle->type == DLM_MLE_MIGRATION */ {
1862 /* should only be getting an assert from new master */
1863 if (assert->node_idx
!= mle
->new_master
) {
1864 mlog(ML_ERROR
, "got assert from %u, but "
1865 "new master is %u, and old master "
1867 assert->node_idx
, mle
->new_master
,
1868 mle
->master
, namelen
, name
);
1874 spin_unlock(&res
->spinlock
);
1877 // mlog(0, "woo! got an assert_master from node %u!\n",
1878 // assert->node_idx);
1884 spin_lock(&mle
->spinlock
);
1885 if (mle
->type
== DLM_MLE_BLOCK
|| mle
->type
== DLM_MLE_MIGRATION
)
1888 /* MASTER mle: if any bits set in the response map
1889 * then the calling node needs to re-assert to clear
1890 * up nodes that this node contacted */
1891 while ((nn
= find_next_bit (mle
->response_map
, O2NM_MAX_NODES
,
1892 nn
+1)) < O2NM_MAX_NODES
) {
1893 if (nn
!= dlm
->node_num
&& nn
!= assert->node_idx
)
1897 mle
->master
= assert->node_idx
;
1898 atomic_set(&mle
->woken
, 1);
1900 spin_unlock(&mle
->spinlock
);
1904 spin_lock(&res
->spinlock
);
1905 if (mle
->type
== DLM_MLE_MIGRATION
) {
1906 mlog(0, "finishing off migration of lockres %.*s, "
1908 res
->lockname
.len
, res
->lockname
.name
,
1909 dlm
->node_num
, mle
->new_master
);
1910 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
1912 dlm_change_lockres_owner(dlm
, res
, mle
->new_master
);
1913 BUG_ON(res
->state
& DLM_LOCK_RES_DIRTY
);
1915 dlm_change_lockres_owner(dlm
, res
, mle
->master
);
1917 spin_unlock(&res
->spinlock
);
1918 have_lockres_ref
= 1;
1923 /* master is known, detach if not already detached.
1924 * ensures that only one assert_master call will happen
1926 spin_lock(&dlm
->master_lock
);
1928 rr
= atomic_read(&mle
->mle_refs
.refcount
);
1929 if (mle
->inuse
> 0) {
1930 if (extra_ref
&& rr
< 3)
1932 else if (!extra_ref
&& rr
< 2)
1935 if (extra_ref
&& rr
< 2)
1937 else if (!extra_ref
&& rr
< 1)
1941 mlog(ML_ERROR
, "%s:%.*s: got assert master from %u "
1942 "that will mess up this node, refs=%d, extra=%d, "
1943 "inuse=%d\n", dlm
->name
, namelen
, name
,
1944 assert->node_idx
, rr
, extra_ref
, mle
->inuse
);
1945 dlm_print_one_mle(mle
);
1947 __dlm_unlink_mle(dlm
, mle
);
1948 __dlm_mle_detach_hb_events(dlm
, mle
);
1951 /* the assert master message now balances the extra
1952 * ref given by the master / migration request message.
1953 * if this is the last put, it will be removed
1957 spin_unlock(&dlm
->master_lock
);
1959 if (res
->owner
!= assert->node_idx
) {
1960 mlog(0, "assert_master from %u, but current "
1961 "owner is %u (%.*s), no mle\n", assert->node_idx
,
1962 res
->owner
, namelen
, name
);
1965 spin_unlock(&dlm
->spinlock
);
1970 spin_lock(&res
->spinlock
);
1971 res
->state
|= DLM_LOCK_RES_SETREF_INPROG
;
1972 spin_unlock(&res
->spinlock
);
1973 *ret_data
= (void *)res
;
1976 if (master_request
) {
1977 mlog(0, "need to tell master to reassert\n");
1978 /* positive. negative would shoot down the node. */
1979 ret
|= DLM_ASSERT_RESPONSE_REASSERT
;
1980 if (!have_lockres_ref
) {
1981 mlog(ML_ERROR
, "strange, got assert from %u, MASTER "
1982 "mle present here for %s:%.*s, but no lockres!\n",
1983 assert->node_idx
, dlm
->name
, namelen
, name
);
1986 if (have_lockres_ref
) {
1987 /* let the master know we have a reference to the lockres */
1988 ret
|= DLM_ASSERT_RESPONSE_MASTERY_REF
;
1989 mlog(0, "%s:%.*s: got assert from %u, need a ref\n",
1990 dlm
->name
, namelen
, name
, assert->node_idx
);
1995 /* kill the caller! */
1996 mlog(ML_ERROR
, "Bad message received from another node. Dumping state "
1997 "and killing the other node now! This node is OK and can continue.\n");
1998 __dlm_print_one_lock_resource(res
);
1999 spin_unlock(&res
->spinlock
);
2000 spin_unlock(&dlm
->spinlock
);
2001 *ret_data
= (void *)res
;
2006 void dlm_assert_master_post_handler(int status
, void *data
, void *ret_data
)
2008 struct dlm_lock_resource
*res
= (struct dlm_lock_resource
*)ret_data
;
2011 spin_lock(&res
->spinlock
);
2012 res
->state
&= ~DLM_LOCK_RES_SETREF_INPROG
;
2013 spin_unlock(&res
->spinlock
);
2015 dlm_lockres_put(res
);
2020 int dlm_dispatch_assert_master(struct dlm_ctxt
*dlm
,
2021 struct dlm_lock_resource
*res
,
2022 int ignore_higher
, u8 request_from
, u32 flags
)
2024 struct dlm_work_item
*item
;
2025 item
= kzalloc(sizeof(*item
), GFP_NOFS
);
2030 /* queue up work for dlm_assert_master_worker */
2031 dlm_grab(dlm
); /* get an extra ref for the work item */
2032 dlm_init_work_item(dlm
, item
, dlm_assert_master_worker
, NULL
);
2033 item
->u
.am
.lockres
= res
; /* already have a ref */
2034 /* can optionally ignore node numbers higher than this node */
2035 item
->u
.am
.ignore_higher
= ignore_higher
;
2036 item
->u
.am
.request_from
= request_from
;
2037 item
->u
.am
.flags
= flags
;
2040 mlog(0, "IGNORE HIGHER: %.*s\n", res
->lockname
.len
,
2041 res
->lockname
.name
);
2043 spin_lock(&dlm
->work_lock
);
2044 list_add_tail(&item
->list
, &dlm
->work_list
);
2045 spin_unlock(&dlm
->work_lock
);
2047 queue_work(dlm
->dlm_worker
, &dlm
->dispatched_work
);
2051 static void dlm_assert_master_worker(struct dlm_work_item
*item
, void *data
)
2053 struct dlm_ctxt
*dlm
= data
;
2055 struct dlm_lock_resource
*res
;
2056 unsigned long nodemap
[BITS_TO_LONGS(O2NM_MAX_NODES
)];
2063 res
= item
->u
.am
.lockres
;
2064 ignore_higher
= item
->u
.am
.ignore_higher
;
2065 request_from
= item
->u
.am
.request_from
;
2066 flags
= item
->u
.am
.flags
;
2068 spin_lock(&dlm
->spinlock
);
2069 memcpy(nodemap
, dlm
->domain_map
, sizeof(nodemap
));
2070 spin_unlock(&dlm
->spinlock
);
2072 clear_bit(dlm
->node_num
, nodemap
);
2073 if (ignore_higher
) {
2074 /* if is this just to clear up mles for nodes below
2075 * this node, do not send the message to the original
2076 * caller or any node number higher than this */
2077 clear_bit(request_from
, nodemap
);
2078 bit
= dlm
->node_num
;
2080 bit
= find_next_bit(nodemap
, O2NM_MAX_NODES
,
2082 if (bit
>= O2NM_MAX_NODES
)
2084 clear_bit(bit
, nodemap
);
2089 * If we're migrating this lock to someone else, we are no
2090 * longer allowed to assert out own mastery. OTOH, we need to
2091 * prevent migration from starting while we're still asserting
2092 * our dominance. The reserved ast delays migration.
2094 spin_lock(&res
->spinlock
);
2095 if (res
->state
& DLM_LOCK_RES_MIGRATING
) {
2096 mlog(0, "Someone asked us to assert mastery, but we're "
2097 "in the middle of migration. Skipping assert, "
2098 "the new master will handle that.\n");
2099 spin_unlock(&res
->spinlock
);
2102 __dlm_lockres_reserve_ast(res
);
2103 spin_unlock(&res
->spinlock
);
2105 /* this call now finishes out the nodemap
2106 * even if one or more nodes die */
2107 mlog(0, "worker about to master %.*s here, this=%u\n",
2108 res
->lockname
.len
, res
->lockname
.name
, dlm
->node_num
);
2109 ret
= dlm_do_assert_master(dlm
, res
, nodemap
, flags
);
2111 /* no need to restart, we are done */
2112 if (!dlm_is_host_down(ret
))
2116 /* Ok, we've asserted ourselves. Let's let migration start. */
2117 dlm_lockres_release_ast(dlm
, res
);
2120 dlm_lockres_put(res
);
2122 mlog(0, "finished with dlm_assert_master_worker\n");
2125 /* SPECIAL CASE for the $RECOVERY lock used by the recovery thread.
2126 * We cannot wait for node recovery to complete to begin mastering this
2127 * lockres because this lockres is used to kick off recovery! ;-)
2128 * So, do a pre-check on all living nodes to see if any of those nodes
2129 * think that $RECOVERY is currently mastered by a dead node. If so,
2130 * we wait a short time to allow that node to get notified by its own
2131 * heartbeat stack, then check again. All $RECOVERY lock resources
2132 * mastered by dead nodes are purged when the hearbeat callback is
2133 * fired, so we can know for sure that it is safe to continue once
2134 * the node returns a live node or no node. */
2135 static int dlm_pre_master_reco_lockres(struct dlm_ctxt
*dlm
,
2136 struct dlm_lock_resource
*res
)
2138 struct dlm_node_iter iter
;
2141 u8 master
= DLM_LOCK_RES_OWNER_UNKNOWN
;
2143 spin_lock(&dlm
->spinlock
);
2144 dlm_node_iter_init(dlm
->domain_map
, &iter
);
2145 spin_unlock(&dlm
->spinlock
);
2147 while ((nodenum
= dlm_node_iter_next(&iter
)) >= 0) {
2148 /* do not send to self */
2149 if (nodenum
== dlm
->node_num
)
2151 ret
= dlm_do_master_requery(dlm
, res
, nodenum
, &master
);
2154 if (!dlm_is_host_down(ret
))
2156 /* host is down, so answer for that node would be
2157 * DLM_LOCK_RES_OWNER_UNKNOWN. continue. */
2161 if (master
!= DLM_LOCK_RES_OWNER_UNKNOWN
) {
2162 /* check to see if this master is in the recovery map */
2163 spin_lock(&dlm
->spinlock
);
2164 if (test_bit(master
, dlm
->recovery_map
)) {
2165 mlog(ML_NOTICE
, "%s: node %u has not seen "
2166 "node %u go down yet, and thinks the "
2167 "dead node is mastering the recovery "
2168 "lock. must wait.\n", dlm
->name
,
2172 spin_unlock(&dlm
->spinlock
);
2173 mlog(0, "%s: reco lock master is %u\n", dlm
->name
,
2182 * DLM_DEREF_LOCKRES_MSG
2185 int dlm_drop_lockres_ref(struct dlm_ctxt
*dlm
, struct dlm_lock_resource
*res
)
2187 struct dlm_deref_lockres deref
;
2189 const char *lockname
;
2190 unsigned int namelen
;
2192 lockname
= res
->lockname
.name
;
2193 namelen
= res
->lockname
.len
;
2194 BUG_ON(namelen
> O2NM_MAX_NAME_LEN
);
2196 mlog(0, "%s:%.*s: sending deref to %d\n",
2197 dlm
->name
, namelen
, lockname
, res
->owner
);
2198 memset(&deref
, 0, sizeof(deref
));
2199 deref
.node_idx
= dlm
->node_num
;
2200 deref
.namelen
= namelen
;
2201 memcpy(deref
.name
, lockname
, namelen
);
2203 ret
= o2net_send_message(DLM_DEREF_LOCKRES_MSG
, dlm
->key
,
2204 &deref
, sizeof(deref
), res
->owner
, &r
);
2206 mlog(ML_ERROR
, "Error %d when sending message %u (key 0x%x) to "
2207 "node %u\n", ret
, DLM_DEREF_LOCKRES_MSG
, dlm
->key
,
2210 /* BAD. other node says I did not have a ref. */
2211 mlog(ML_ERROR
,"while dropping ref on %s:%.*s "
2212 "(master=%u) got %d.\n", dlm
->name
, namelen
,
2213 lockname
, res
->owner
, r
);
2214 dlm_print_one_lock_resource(res
);
2220 int dlm_deref_lockres_handler(struct o2net_msg
*msg
, u32 len
, void *data
,
2223 struct dlm_ctxt
*dlm
= data
;
2224 struct dlm_deref_lockres
*deref
= (struct dlm_deref_lockres
*)msg
->buf
;
2225 struct dlm_lock_resource
*res
= NULL
;
2227 unsigned int namelen
;
2231 struct dlm_work_item
*item
;
2239 namelen
= deref
->namelen
;
2240 node
= deref
->node_idx
;
2242 if (namelen
> DLM_LOCKID_NAME_MAX
) {
2243 mlog(ML_ERROR
, "Invalid name length!");
2246 if (deref
->node_idx
>= O2NM_MAX_NODES
) {
2247 mlog(ML_ERROR
, "Invalid node number: %u\n", node
);
2251 hash
= dlm_lockid_hash(name
, namelen
);
2253 spin_lock(&dlm
->spinlock
);
2254 res
= __dlm_lookup_lockres_full(dlm
, name
, namelen
, hash
);
2256 spin_unlock(&dlm
->spinlock
);
2257 mlog(ML_ERROR
, "%s:%.*s: bad lockres name\n",
2258 dlm
->name
, namelen
, name
);
2261 spin_unlock(&dlm
->spinlock
);
2263 spin_lock(&res
->spinlock
);
2264 if (res
->state
& DLM_LOCK_RES_SETREF_INPROG
)
2267 BUG_ON(res
->state
& DLM_LOCK_RES_DROPPING_REF
);
2268 if (test_bit(node
, res
->refmap
)) {
2269 dlm_lockres_clear_refmap_bit(node
, res
);
2273 spin_unlock(&res
->spinlock
);
2277 dlm_lockres_calc_usage(dlm
, res
);
2279 mlog(ML_ERROR
, "%s:%.*s: node %u trying to drop ref "
2280 "but it is already dropped!\n", dlm
->name
,
2281 res
->lockname
.len
, res
->lockname
.name
, node
);
2282 dlm_print_one_lock_resource(res
);
2288 item
= kzalloc(sizeof(*item
), GFP_NOFS
);
2295 dlm_init_work_item(dlm
, item
, dlm_deref_lockres_worker
, NULL
);
2296 item
->u
.dl
.deref_res
= res
;
2297 item
->u
.dl
.deref_node
= node
;
2299 spin_lock(&dlm
->work_lock
);
2300 list_add_tail(&item
->list
, &dlm
->work_list
);
2301 spin_unlock(&dlm
->work_lock
);
2303 queue_work(dlm
->dlm_worker
, &dlm
->dispatched_work
);
2308 dlm_lockres_put(res
);
2314 static void dlm_deref_lockres_worker(struct dlm_work_item
*item
, void *data
)
2316 struct dlm_ctxt
*dlm
;
2317 struct dlm_lock_resource
*res
;
2322 res
= item
->u
.dl
.deref_res
;
2323 node
= item
->u
.dl
.deref_node
;
2325 spin_lock(&res
->spinlock
);
2326 BUG_ON(res
->state
& DLM_LOCK_RES_DROPPING_REF
);
2327 if (test_bit(node
, res
->refmap
)) {
2328 __dlm_wait_on_lockres_flags(res
, DLM_LOCK_RES_SETREF_INPROG
);
2329 dlm_lockres_clear_refmap_bit(node
, res
);
2332 spin_unlock(&res
->spinlock
);
2335 mlog(0, "%s:%.*s node %u ref dropped in dispatch\n",
2336 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
, node
);
2337 dlm_lockres_calc_usage(dlm
, res
);
2339 mlog(ML_ERROR
, "%s:%.*s: node %u trying to drop ref "
2340 "but it is already dropped!\n", dlm
->name
,
2341 res
->lockname
.len
, res
->lockname
.name
, node
);
2342 dlm_print_one_lock_resource(res
);
2345 dlm_lockres_put(res
);
2348 /* Checks whether the lockres can be migrated. Returns 0 if yes, < 0
2349 * if not. If 0, numlocks is set to the number of locks in the lockres.
2351 static int dlm_is_lockres_migrateable(struct dlm_ctxt
*dlm
,
2352 struct dlm_lock_resource
*res
,
2358 struct list_head
*queue
;
2359 struct dlm_lock
*lock
;
2361 assert_spin_locked(&res
->spinlock
);
2364 if (res
->owner
== DLM_LOCK_RES_OWNER_UNKNOWN
) {
2365 mlog(0, "cannot migrate lockres with unknown owner!\n");
2369 if (res
->owner
!= dlm
->node_num
) {
2370 mlog(0, "cannot migrate lockres this node doesn't own!\n");
2375 queue
= &res
->granted
;
2376 for (i
= 0; i
< 3; i
++) {
2377 list_for_each_entry(lock
, queue
, list
) {
2379 if (lock
->ml
.node
== dlm
->node_num
) {
2380 mlog(0, "found a lock owned by this node still "
2381 "on the %s queue! will not migrate this "
2382 "lockres\n", (i
== 0 ? "granted" :
2383 (i
== 1 ? "converting" :
2393 mlog(0, "migrateable lockres having %d locks\n", *numlocks
);
2400 * DLM_MIGRATE_LOCKRES
2404 static int dlm_migrate_lockres(struct dlm_ctxt
*dlm
,
2405 struct dlm_lock_resource
*res
,
2408 struct dlm_master_list_entry
*mle
= NULL
;
2409 struct dlm_master_list_entry
*oldmle
= NULL
;
2410 struct dlm_migratable_lockres
*mres
= NULL
;
2413 unsigned int namelen
;
2421 name
= res
->lockname
.name
;
2422 namelen
= res
->lockname
.len
;
2424 mlog(0, "migrating %.*s to %u\n", namelen
, name
, target
);
2427 * ensure this lockres is a proper candidate for migration
2429 spin_lock(&res
->spinlock
);
2430 ret
= dlm_is_lockres_migrateable(dlm
, res
, &numlocks
);
2432 spin_unlock(&res
->spinlock
);
2435 spin_unlock(&res
->spinlock
);
2438 if (numlocks
== 0) {
2439 mlog(0, "no locks were found on this lockres! done!\n");
2444 * preallocate up front
2445 * if this fails, abort
2449 mres
= (struct dlm_migratable_lockres
*) __get_free_page(GFP_NOFS
);
2455 mle
= kmem_cache_alloc(dlm_mle_cache
, GFP_NOFS
);
2463 * find a node to migrate the lockres to
2466 mlog(0, "picking a migration node\n");
2467 spin_lock(&dlm
->spinlock
);
2468 /* pick a new node */
2469 if (!test_bit(target
, dlm
->domain_map
) ||
2470 target
>= O2NM_MAX_NODES
) {
2471 target
= dlm_pick_migration_target(dlm
, res
);
2473 mlog(0, "node %u chosen for migration\n", target
);
2475 if (target
>= O2NM_MAX_NODES
||
2476 !test_bit(target
, dlm
->domain_map
)) {
2477 /* target chosen is not alive */
2482 spin_unlock(&dlm
->spinlock
);
2486 mlog(0, "continuing with target = %u\n", target
);
2489 * clear any existing master requests and
2490 * add the migration mle to the list
2492 spin_lock(&dlm
->master_lock
);
2493 ret
= dlm_add_migration_mle(dlm
, res
, mle
, &oldmle
, name
,
2494 namelen
, target
, dlm
->node_num
);
2495 spin_unlock(&dlm
->master_lock
);
2496 spin_unlock(&dlm
->spinlock
);
2498 if (ret
== -EEXIST
) {
2499 mlog(0, "another process is already migrating it\n");
2505 * set the MIGRATING flag and flush asts
2506 * if we fail after this we need to re-dirty the lockres
2508 if (dlm_mark_lockres_migrating(dlm
, res
, target
) < 0) {
2509 mlog(ML_ERROR
, "tried to migrate %.*s to %u, but "
2510 "the target went down.\n", res
->lockname
.len
,
2511 res
->lockname
.name
, target
);
2512 spin_lock(&res
->spinlock
);
2513 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
2515 spin_unlock(&res
->spinlock
);
2521 /* master is known, detach if not already detached */
2522 dlm_mle_detach_hb_events(dlm
, oldmle
);
2523 dlm_put_mle(oldmle
);
2528 dlm_mle_detach_hb_events(dlm
, mle
);
2531 kmem_cache_free(dlm_mle_cache
, mle
);
2537 * at this point, we have a migration target, an mle
2538 * in the master list, and the MIGRATING flag set on
2542 /* now that remote nodes are spinning on the MIGRATING flag,
2543 * ensure that all assert_master work is flushed. */
2544 flush_workqueue(dlm
->dlm_worker
);
2546 /* get an extra reference on the mle.
2547 * otherwise the assert_master from the new
2548 * master will destroy this.
2549 * also, make sure that all callers of dlm_get_mle
2550 * take both dlm->spinlock and dlm->master_lock */
2551 spin_lock(&dlm
->spinlock
);
2552 spin_lock(&dlm
->master_lock
);
2553 dlm_get_mle_inuse(mle
);
2554 spin_unlock(&dlm
->master_lock
);
2555 spin_unlock(&dlm
->spinlock
);
2557 /* notify new node and send all lock state */
2558 /* call send_one_lockres with migration flag.
2559 * this serves as notice to the target node that a
2560 * migration is starting. */
2561 ret
= dlm_send_one_lockres(dlm
, res
, mres
, target
,
2562 DLM_MRES_MIGRATION
);
2565 mlog(0, "migration to node %u failed with %d\n",
2567 /* migration failed, detach and clean up mle */
2568 dlm_mle_detach_hb_events(dlm
, mle
);
2570 dlm_put_mle_inuse(mle
);
2571 spin_lock(&res
->spinlock
);
2572 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
2574 spin_unlock(&res
->spinlock
);
2578 /* at this point, the target sends a message to all nodes,
2579 * (using dlm_do_migrate_request). this node is skipped since
2580 * we had to put an mle in the list to begin the process. this
2581 * node now waits for target to do an assert master. this node
2582 * will be the last one notified, ensuring that the migration
2583 * is complete everywhere. if the target dies while this is
2584 * going on, some nodes could potentially see the target as the
2585 * master, so it is important that my recovery finds the migration
2586 * mle and sets the master to UNKNOWN. */
2589 /* wait for new node to assert master */
2591 ret
= wait_event_interruptible_timeout(mle
->wq
,
2592 (atomic_read(&mle
->woken
) == 1),
2593 msecs_to_jiffies(5000));
2596 if (atomic_read(&mle
->woken
) == 1 ||
2597 res
->owner
== target
)
2600 mlog(0, "%s:%.*s: timed out during migration\n",
2601 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
);
2602 /* avoid hang during shutdown when migrating lockres
2603 * to a node which also goes down */
2604 if (dlm_is_node_dead(dlm
, target
)) {
2605 mlog(0, "%s:%.*s: expected migration "
2606 "target %u is no longer up, restarting\n",
2607 dlm
->name
, res
->lockname
.len
,
2608 res
->lockname
.name
, target
);
2610 /* migration failed, detach and clean up mle */
2611 dlm_mle_detach_hb_events(dlm
, mle
);
2613 dlm_put_mle_inuse(mle
);
2614 spin_lock(&res
->spinlock
);
2615 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
2617 spin_unlock(&res
->spinlock
);
2621 mlog(0, "%s:%.*s: caught signal during migration\n",
2622 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
);
2625 /* all done, set the owner, clear the flag */
2626 spin_lock(&res
->spinlock
);
2627 dlm_set_lockres_owner(dlm
, res
, target
);
2628 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
2629 dlm_remove_nonlocal_locks(dlm
, res
);
2630 spin_unlock(&res
->spinlock
);
2633 /* master is known, detach if not already detached */
2634 dlm_mle_detach_hb_events(dlm
, mle
);
2635 dlm_put_mle_inuse(mle
);
2638 dlm_lockres_calc_usage(dlm
, res
);
2641 /* re-dirty the lockres if we failed */
2643 dlm_kick_thread(dlm
, res
);
2645 /* wake up waiters if the MIGRATING flag got set
2646 * but migration failed */
2652 free_page((unsigned long)mres
);
2656 mlog(0, "returning %d\n", ret
);
2660 #define DLM_MIGRATION_RETRY_MS 100
2662 /* Should be called only after beginning the domain leave process.
2663 * There should not be any remaining locks on nonlocal lock resources,
2664 * and there should be no local locks left on locally mastered resources.
2666 * Called with the dlm spinlock held, may drop it to do migration, but
2667 * will re-acquire before exit.
2669 * Returns: 1 if dlm->spinlock was dropped/retaken, 0 if never dropped */
2670 int dlm_empty_lockres(struct dlm_ctxt
*dlm
, struct dlm_lock_resource
*res
)
2673 int lock_dropped
= 0;
2676 spin_lock(&res
->spinlock
);
2677 if (res
->owner
!= dlm
->node_num
) {
2678 if (!__dlm_lockres_unused(res
)) {
2679 mlog(ML_ERROR
, "%s:%.*s: this node is not master, "
2680 "trying to free this but locks remain\n",
2681 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
);
2683 spin_unlock(&res
->spinlock
);
2687 /* No need to migrate a lockres having no locks */
2688 ret
= dlm_is_lockres_migrateable(dlm
, res
, &numlocks
);
2689 if (ret
>= 0 && numlocks
== 0) {
2690 spin_unlock(&res
->spinlock
);
2693 spin_unlock(&res
->spinlock
);
2695 /* Wheee! Migrate lockres here! Will sleep so drop spinlock. */
2696 spin_unlock(&dlm
->spinlock
);
2699 ret
= dlm_migrate_lockres(dlm
, res
, O2NM_MAX_NODES
);
2702 if (ret
== -ENOTEMPTY
) {
2703 mlog(ML_ERROR
, "lockres %.*s still has local locks!\n",
2704 res
->lockname
.len
, res
->lockname
.name
);
2708 mlog(0, "lockres %.*s: migrate failed, "
2709 "retrying\n", res
->lockname
.len
,
2710 res
->lockname
.name
);
2711 msleep(DLM_MIGRATION_RETRY_MS
);
2713 spin_lock(&dlm
->spinlock
);
2715 return lock_dropped
;
2718 int dlm_lock_basts_flushed(struct dlm_ctxt
*dlm
, struct dlm_lock
*lock
)
2721 spin_lock(&dlm
->ast_lock
);
2722 spin_lock(&lock
->spinlock
);
2723 ret
= (list_empty(&lock
->bast_list
) && !lock
->bast_pending
);
2724 spin_unlock(&lock
->spinlock
);
2725 spin_unlock(&dlm
->ast_lock
);
2729 static int dlm_migration_can_proceed(struct dlm_ctxt
*dlm
,
2730 struct dlm_lock_resource
*res
,
2734 spin_lock(&res
->spinlock
);
2735 can_proceed
= !!(res
->state
& DLM_LOCK_RES_MIGRATING
);
2736 spin_unlock(&res
->spinlock
);
2738 /* target has died, so make the caller break out of the
2739 * wait_event, but caller must recheck the domain_map */
2740 spin_lock(&dlm
->spinlock
);
2741 if (!test_bit(mig_target
, dlm
->domain_map
))
2743 spin_unlock(&dlm
->spinlock
);
2747 static int dlm_lockres_is_dirty(struct dlm_ctxt
*dlm
,
2748 struct dlm_lock_resource
*res
)
2751 spin_lock(&res
->spinlock
);
2752 ret
= !!(res
->state
& DLM_LOCK_RES_DIRTY
);
2753 spin_unlock(&res
->spinlock
);
2758 static int dlm_mark_lockres_migrating(struct dlm_ctxt
*dlm
,
2759 struct dlm_lock_resource
*res
,
2764 mlog(0, "dlm_mark_lockres_migrating: %.*s, from %u to %u\n",
2765 res
->lockname
.len
, res
->lockname
.name
, dlm
->node_num
,
2767 /* need to set MIGRATING flag on lockres. this is done by
2768 * ensuring that all asts have been flushed for this lockres. */
2769 spin_lock(&res
->spinlock
);
2770 BUG_ON(res
->migration_pending
);
2771 res
->migration_pending
= 1;
2772 /* strategy is to reserve an extra ast then release
2773 * it below, letting the release do all of the work */
2774 __dlm_lockres_reserve_ast(res
);
2775 spin_unlock(&res
->spinlock
);
2777 /* now flush all the pending asts */
2778 dlm_kick_thread(dlm
, res
);
2779 /* before waiting on DIRTY, block processes which may
2780 * try to dirty the lockres before MIGRATING is set */
2781 spin_lock(&res
->spinlock
);
2782 BUG_ON(res
->state
& DLM_LOCK_RES_BLOCK_DIRTY
);
2783 res
->state
|= DLM_LOCK_RES_BLOCK_DIRTY
;
2784 spin_unlock(&res
->spinlock
);
2785 /* now wait on any pending asts and the DIRTY state */
2786 wait_event(dlm
->ast_wq
, !dlm_lockres_is_dirty(dlm
, res
));
2787 dlm_lockres_release_ast(dlm
, res
);
2789 mlog(0, "about to wait on migration_wq, dirty=%s\n",
2790 res
->state
& DLM_LOCK_RES_DIRTY
? "yes" : "no");
2791 /* if the extra ref we just put was the final one, this
2792 * will pass thru immediately. otherwise, we need to wait
2793 * for the last ast to finish. */
2795 ret
= wait_event_interruptible_timeout(dlm
->migration_wq
,
2796 dlm_migration_can_proceed(dlm
, res
, target
),
2797 msecs_to_jiffies(1000));
2799 mlog(0, "woken again: migrating? %s, dead? %s\n",
2800 res
->state
& DLM_LOCK_RES_MIGRATING
? "yes":"no",
2801 test_bit(target
, dlm
->domain_map
) ? "no":"yes");
2803 mlog(0, "all is well: migrating? %s, dead? %s\n",
2804 res
->state
& DLM_LOCK_RES_MIGRATING
? "yes":"no",
2805 test_bit(target
, dlm
->domain_map
) ? "no":"yes");
2807 if (!dlm_migration_can_proceed(dlm
, res
, target
)) {
2808 mlog(0, "trying again...\n");
2813 /* did the target go down or die? */
2814 spin_lock(&dlm
->spinlock
);
2815 if (!test_bit(target
, dlm
->domain_map
)) {
2816 mlog(ML_ERROR
, "aha. migration target %u just went down\n",
2820 spin_unlock(&dlm
->spinlock
);
2823 * if target is down, we need to clear DLM_LOCK_RES_BLOCK_DIRTY for
2824 * another try; otherwise, we are sure the MIGRATING state is there,
2825 * drop the unneded state which blocked threads trying to DIRTY
2827 spin_lock(&res
->spinlock
);
2828 BUG_ON(!(res
->state
& DLM_LOCK_RES_BLOCK_DIRTY
));
2829 res
->state
&= ~DLM_LOCK_RES_BLOCK_DIRTY
;
2831 BUG_ON(!(res
->state
& DLM_LOCK_RES_MIGRATING
));
2832 spin_unlock(&res
->spinlock
);
2837 * o the DLM_LOCK_RES_MIGRATING flag is set if target not down
2838 * o there are no pending asts on this lockres
2839 * o all processes trying to reserve an ast on this
2840 * lockres must wait for the MIGRATING flag to clear
2845 /* last step in the migration process.
2846 * original master calls this to free all of the dlm_lock
2847 * structures that used to be for other nodes. */
2848 static void dlm_remove_nonlocal_locks(struct dlm_ctxt
*dlm
,
2849 struct dlm_lock_resource
*res
)
2851 struct list_head
*queue
= &res
->granted
;
2853 struct dlm_lock
*lock
, *next
;
2855 assert_spin_locked(&res
->spinlock
);
2857 BUG_ON(res
->owner
== dlm
->node_num
);
2859 for (i
=0; i
<3; i
++) {
2860 list_for_each_entry_safe(lock
, next
, queue
, list
) {
2861 if (lock
->ml
.node
!= dlm
->node_num
) {
2862 mlog(0, "putting lock for node %u\n",
2864 /* be extra careful */
2865 BUG_ON(!list_empty(&lock
->ast_list
));
2866 BUG_ON(!list_empty(&lock
->bast_list
));
2867 BUG_ON(lock
->ast_pending
);
2868 BUG_ON(lock
->bast_pending
);
2869 dlm_lockres_clear_refmap_bit(lock
->ml
.node
, res
);
2870 list_del_init(&lock
->list
);
2872 /* In a normal unlock, we would have added a
2873 * DLM_UNLOCK_FREE_LOCK action. Force it. */
2881 bit
= find_next_bit(res
->refmap
, O2NM_MAX_NODES
, bit
);
2882 if (bit
>= O2NM_MAX_NODES
)
2884 /* do not clear the local node reference, if there is a
2885 * process holding this, let it drop the ref itself */
2886 if (bit
!= dlm
->node_num
) {
2887 mlog(0, "%s:%.*s: node %u had a ref to this "
2888 "migrating lockres, clearing\n", dlm
->name
,
2889 res
->lockname
.len
, res
->lockname
.name
, bit
);
2890 dlm_lockres_clear_refmap_bit(bit
, res
);
2896 /* for now this is not too intelligent. we will
2897 * need stats to make this do the right thing.
2898 * this just finds the first lock on one of the
2899 * queues and uses that node as the target. */
2900 static u8
dlm_pick_migration_target(struct dlm_ctxt
*dlm
,
2901 struct dlm_lock_resource
*res
)
2904 struct list_head
*queue
= &res
->granted
;
2905 struct dlm_lock
*lock
;
2908 assert_spin_locked(&dlm
->spinlock
);
2910 spin_lock(&res
->spinlock
);
2911 for (i
=0; i
<3; i
++) {
2912 list_for_each_entry(lock
, queue
, list
) {
2913 /* up to the caller to make sure this node
2915 if (lock
->ml
.node
!= dlm
->node_num
) {
2916 spin_unlock(&res
->spinlock
);
2917 return lock
->ml
.node
;
2922 spin_unlock(&res
->spinlock
);
2923 mlog(0, "have not found a suitable target yet! checking domain map\n");
2925 /* ok now we're getting desperate. pick anyone alive. */
2928 nodenum
= find_next_bit(dlm
->domain_map
,
2929 O2NM_MAX_NODES
, nodenum
+1);
2930 mlog(0, "found %d in domain map\n", nodenum
);
2931 if (nodenum
>= O2NM_MAX_NODES
)
2933 if (nodenum
!= dlm
->node_num
) {
2934 mlog(0, "picking %d\n", nodenum
);
2939 mlog(0, "giving up. no master to migrate to\n");
2940 return DLM_LOCK_RES_OWNER_UNKNOWN
;
2945 /* this is called by the new master once all lockres
2946 * data has been received */
2947 static int dlm_do_migrate_request(struct dlm_ctxt
*dlm
,
2948 struct dlm_lock_resource
*res
,
2949 u8 master
, u8 new_master
,
2950 struct dlm_node_iter
*iter
)
2952 struct dlm_migrate_request migrate
;
2953 int ret
, skip
, status
= 0;
2956 memset(&migrate
, 0, sizeof(migrate
));
2957 migrate
.namelen
= res
->lockname
.len
;
2958 memcpy(migrate
.name
, res
->lockname
.name
, migrate
.namelen
);
2959 migrate
.new_master
= new_master
;
2960 migrate
.master
= master
;
2964 /* send message to all nodes, except the master and myself */
2965 while ((nodenum
= dlm_node_iter_next(iter
)) >= 0) {
2966 if (nodenum
== master
||
2967 nodenum
== new_master
)
2970 /* We could race exit domain. If exited, skip. */
2971 spin_lock(&dlm
->spinlock
);
2972 skip
= (!test_bit(nodenum
, dlm
->domain_map
));
2973 spin_unlock(&dlm
->spinlock
);
2975 clear_bit(nodenum
, iter
->node_map
);
2979 ret
= o2net_send_message(DLM_MIGRATE_REQUEST_MSG
, dlm
->key
,
2980 &migrate
, sizeof(migrate
), nodenum
,
2983 mlog(ML_ERROR
, "Error %d when sending message %u (key "
2984 "0x%x) to node %u\n", ret
, DLM_MIGRATE_REQUEST_MSG
,
2986 if (!dlm_is_host_down(ret
)) {
2987 mlog(ML_ERROR
, "unhandled error=%d!\n", ret
);
2990 clear_bit(nodenum
, iter
->node_map
);
2992 } else if (status
< 0) {
2993 mlog(0, "migrate request (node %u) returned %d!\n",
2996 } else if (status
== DLM_MIGRATE_RESPONSE_MASTERY_REF
) {
2997 /* during the migration request we short-circuited
2998 * the mastery of the lockres. make sure we have
2999 * a mastery ref for nodenum */
3000 mlog(0, "%s:%.*s: need ref for node %u\n",
3001 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
,
3003 spin_lock(&res
->spinlock
);
3004 dlm_lockres_set_refmap_bit(nodenum
, res
);
3005 spin_unlock(&res
->spinlock
);
3012 mlog(0, "returning ret=%d\n", ret
);
3017 /* if there is an existing mle for this lockres, we now know who the master is.
3018 * (the one who sent us *this* message) we can clear it up right away.
3019 * since the process that put the mle on the list still has a reference to it,
3020 * we can unhash it now, set the master and wake the process. as a result,
3021 * we will have no mle in the list to start with. now we can add an mle for
3022 * the migration and this should be the only one found for those scanning the
3024 int dlm_migrate_request_handler(struct o2net_msg
*msg
, u32 len
, void *data
,
3027 struct dlm_ctxt
*dlm
= data
;
3028 struct dlm_lock_resource
*res
= NULL
;
3029 struct dlm_migrate_request
*migrate
= (struct dlm_migrate_request
*) msg
->buf
;
3030 struct dlm_master_list_entry
*mle
= NULL
, *oldmle
= NULL
;
3032 unsigned int namelen
, hash
;
3038 name
= migrate
->name
;
3039 namelen
= migrate
->namelen
;
3040 hash
= dlm_lockid_hash(name
, namelen
);
3042 /* preallocate.. if this fails, abort */
3043 mle
= kmem_cache_alloc(dlm_mle_cache
, GFP_NOFS
);
3050 /* check for pre-existing lock */
3051 spin_lock(&dlm
->spinlock
);
3052 res
= __dlm_lookup_lockres(dlm
, name
, namelen
, hash
);
3053 spin_lock(&dlm
->master_lock
);
3056 spin_lock(&res
->spinlock
);
3057 if (res
->state
& DLM_LOCK_RES_RECOVERING
) {
3058 /* if all is working ok, this can only mean that we got
3059 * a migrate request from a node that we now see as
3060 * dead. what can we do here? drop it to the floor? */
3061 spin_unlock(&res
->spinlock
);
3062 mlog(ML_ERROR
, "Got a migrate request, but the "
3063 "lockres is marked as recovering!");
3064 kmem_cache_free(dlm_mle_cache
, mle
);
3065 ret
= -EINVAL
; /* need a better solution */
3068 res
->state
|= DLM_LOCK_RES_MIGRATING
;
3069 spin_unlock(&res
->spinlock
);
3072 /* ignore status. only nonzero status would BUG. */
3073 ret
= dlm_add_migration_mle(dlm
, res
, mle
, &oldmle
,
3075 migrate
->new_master
,
3079 spin_unlock(&dlm
->master_lock
);
3080 spin_unlock(&dlm
->spinlock
);
3083 /* master is known, detach if not already detached */
3084 dlm_mle_detach_hb_events(dlm
, oldmle
);
3085 dlm_put_mle(oldmle
);
3089 dlm_lockres_put(res
);
3095 /* must be holding dlm->spinlock and dlm->master_lock
3096 * when adding a migration mle, we can clear any other mles
3097 * in the master list because we know with certainty that
3098 * the master is "master". so we remove any old mle from
3099 * the list after setting it's master field, and then add
3100 * the new migration mle. this way we can hold with the rule
3101 * of having only one mle for a given lock name at all times. */
3102 static int dlm_add_migration_mle(struct dlm_ctxt
*dlm
,
3103 struct dlm_lock_resource
*res
,
3104 struct dlm_master_list_entry
*mle
,
3105 struct dlm_master_list_entry
**oldmle
,
3106 const char *name
, unsigned int namelen
,
3107 u8 new_master
, u8 master
)
3116 assert_spin_locked(&dlm
->spinlock
);
3117 assert_spin_locked(&dlm
->master_lock
);
3119 /* caller is responsible for any ref taken here on oldmle */
3120 found
= dlm_find_mle(dlm
, oldmle
, (char *)name
, namelen
);
3122 struct dlm_master_list_entry
*tmp
= *oldmle
;
3123 spin_lock(&tmp
->spinlock
);
3124 if (tmp
->type
== DLM_MLE_MIGRATION
) {
3125 if (master
== dlm
->node_num
) {
3126 /* ah another process raced me to it */
3127 mlog(0, "tried to migrate %.*s, but some "
3128 "process beat me to it\n",
3132 /* bad. 2 NODES are trying to migrate! */
3133 mlog(ML_ERROR
, "migration error mle: "
3134 "master=%u new_master=%u // request: "
3135 "master=%u new_master=%u // "
3137 tmp
->master
, tmp
->new_master
,
3143 /* this is essentially what assert_master does */
3144 tmp
->master
= master
;
3145 atomic_set(&tmp
->woken
, 1);
3147 /* remove it so that only one mle will be found */
3148 __dlm_unlink_mle(dlm
, tmp
);
3149 __dlm_mle_detach_hb_events(dlm
, tmp
);
3150 ret
= DLM_MIGRATE_RESPONSE_MASTERY_REF
;
3151 mlog(0, "%s:%.*s: master=%u, newmaster=%u, "
3152 "telling master to get ref for cleared out mle "
3153 "during migration\n", dlm
->name
, namelen
, name
,
3154 master
, new_master
);
3156 spin_unlock(&tmp
->spinlock
);
3159 /* now add a migration mle to the tail of the list */
3160 dlm_init_mle(mle
, DLM_MLE_MIGRATION
, dlm
, res
, name
, namelen
);
3161 mle
->new_master
= new_master
;
3162 /* the new master will be sending an assert master for this.
3163 * at that point we will get the refmap reference */
3164 mle
->master
= master
;
3165 /* do this for consistency with other mle types */
3166 set_bit(new_master
, mle
->maybe_map
);
3167 __dlm_insert_mle(dlm
, mle
);
3173 * Sets the owner of the lockres, associated to the mle, to UNKNOWN
3175 static struct dlm_lock_resource
*dlm_reset_mleres_owner(struct dlm_ctxt
*dlm
,
3176 struct dlm_master_list_entry
*mle
)
3178 struct dlm_lock_resource
*res
;
3180 /* Find the lockres associated to the mle and set its owner to UNK */
3181 res
= __dlm_lookup_lockres(dlm
, mle
->mname
, mle
->mnamelen
,
3184 spin_unlock(&dlm
->master_lock
);
3186 /* move lockres onto recovery list */
3187 spin_lock(&res
->spinlock
);
3188 dlm_set_lockres_owner(dlm
, res
, DLM_LOCK_RES_OWNER_UNKNOWN
);
3189 dlm_move_lockres_to_recovery_list(dlm
, res
);
3190 spin_unlock(&res
->spinlock
);
3191 dlm_lockres_put(res
);
3193 /* about to get rid of mle, detach from heartbeat */
3194 __dlm_mle_detach_hb_events(dlm
, mle
);
3197 spin_lock(&dlm
->master_lock
);
3199 spin_unlock(&dlm
->master_lock
);
3205 static void dlm_clean_migration_mle(struct dlm_ctxt
*dlm
,
3206 struct dlm_master_list_entry
*mle
)
3208 __dlm_mle_detach_hb_events(dlm
, mle
);
3210 spin_lock(&mle
->spinlock
);
3211 __dlm_unlink_mle(dlm
, mle
);
3212 atomic_set(&mle
->woken
, 1);
3213 spin_unlock(&mle
->spinlock
);
3218 static void dlm_clean_block_mle(struct dlm_ctxt
*dlm
,
3219 struct dlm_master_list_entry
*mle
, u8 dead_node
)
3223 BUG_ON(mle
->type
!= DLM_MLE_BLOCK
);
3225 spin_lock(&mle
->spinlock
);
3226 bit
= find_next_bit(mle
->maybe_map
, O2NM_MAX_NODES
, 0);
3227 if (bit
!= dead_node
) {
3228 mlog(0, "mle found, but dead node %u would not have been "
3229 "master\n", dead_node
);
3230 spin_unlock(&mle
->spinlock
);
3232 /* Must drop the refcount by one since the assert_master will
3233 * never arrive. This may result in the mle being unlinked and
3234 * freed, but there may still be a process waiting in the
3235 * dlmlock path which is fine. */
3236 mlog(0, "node %u was expected master\n", dead_node
);
3237 atomic_set(&mle
->woken
, 1);
3238 spin_unlock(&mle
->spinlock
);
3241 /* Do not need events any longer, so detach from heartbeat */
3242 __dlm_mle_detach_hb_events(dlm
, mle
);
3247 void dlm_clean_master_list(struct dlm_ctxt
*dlm
, u8 dead_node
)
3249 struct dlm_master_list_entry
*mle
;
3250 struct dlm_lock_resource
*res
;
3251 struct hlist_head
*bucket
;
3252 struct hlist_node
*list
;
3255 mlog_entry("dlm=%s, dead node=%u\n", dlm
->name
, dead_node
);
3257 assert_spin_locked(&dlm
->spinlock
);
3259 /* clean the master list */
3260 spin_lock(&dlm
->master_lock
);
3261 for (i
= 0; i
< DLM_HASH_BUCKETS
; i
++) {
3262 bucket
= dlm_master_hash(dlm
, i
);
3263 hlist_for_each(list
, bucket
) {
3264 mle
= hlist_entry(list
, struct dlm_master_list_entry
,
3267 BUG_ON(mle
->type
!= DLM_MLE_BLOCK
&&
3268 mle
->type
!= DLM_MLE_MASTER
&&
3269 mle
->type
!= DLM_MLE_MIGRATION
);
3271 /* MASTER mles are initiated locally. The waiting
3272 * process will notice the node map change shortly.
3273 * Let that happen as normal. */
3274 if (mle
->type
== DLM_MLE_MASTER
)
3277 /* BLOCK mles are initiated by other nodes. Need to
3278 * clean up if the dead node would have been the
3280 if (mle
->type
== DLM_MLE_BLOCK
) {
3281 dlm_clean_block_mle(dlm
, mle
, dead_node
);
3285 /* Everything else is a MIGRATION mle */
3287 /* The rule for MIGRATION mles is that the master
3288 * becomes UNKNOWN if *either* the original or the new
3289 * master dies. All UNKNOWN lockres' are sent to
3290 * whichever node becomes the recovery master. The new
3291 * master is responsible for determining if there is
3292 * still a master for this lockres, or if he needs to
3293 * take over mastery. Either way, this node should
3294 * expect another message to resolve this. */
3296 if (mle
->master
!= dead_node
&&
3297 mle
->new_master
!= dead_node
)
3300 /* If we have reached this point, this mle needs to be
3301 * removed from the list and freed. */
3302 dlm_clean_migration_mle(dlm
, mle
);
3304 mlog(0, "%s: node %u died during migration from "
3305 "%u to %u!\n", dlm
->name
, dead_node
, mle
->master
,
3308 /* If we find a lockres associated with the mle, we've
3309 * hit this rare case that messes up our lock ordering.
3310 * If so, we need to drop the master lock so that we can
3311 * take the lockres lock, meaning that we will have to
3312 * restart from the head of list. */
3313 res
= dlm_reset_mleres_owner(dlm
, mle
);
3318 /* This may be the last reference */
3322 spin_unlock(&dlm
->master_lock
);
3325 int dlm_finish_migration(struct dlm_ctxt
*dlm
, struct dlm_lock_resource
*res
,
3328 struct dlm_node_iter iter
;
3331 spin_lock(&dlm
->spinlock
);
3332 dlm_node_iter_init(dlm
->domain_map
, &iter
);
3333 clear_bit(old_master
, iter
.node_map
);
3334 clear_bit(dlm
->node_num
, iter
.node_map
);
3335 spin_unlock(&dlm
->spinlock
);
3337 /* ownership of the lockres is changing. account for the
3338 * mastery reference here since old_master will briefly have
3339 * a reference after the migration completes */
3340 spin_lock(&res
->spinlock
);
3341 dlm_lockres_set_refmap_bit(old_master
, res
);
3342 spin_unlock(&res
->spinlock
);
3344 mlog(0, "now time to do a migrate request to other nodes\n");
3345 ret
= dlm_do_migrate_request(dlm
, res
, old_master
,
3346 dlm
->node_num
, &iter
);
3352 mlog(0, "doing assert master of %.*s to all except the original node\n",
3353 res
->lockname
.len
, res
->lockname
.name
);
3354 /* this call now finishes out the nodemap
3355 * even if one or more nodes die */
3356 ret
= dlm_do_assert_master(dlm
, res
, iter
.node_map
,
3357 DLM_ASSERT_MASTER_FINISH_MIGRATION
);
3359 /* no longer need to retry. all living nodes contacted. */
3364 memset(iter
.node_map
, 0, sizeof(iter
.node_map
));
3365 set_bit(old_master
, iter
.node_map
);
3366 mlog(0, "doing assert master of %.*s back to %u\n",
3367 res
->lockname
.len
, res
->lockname
.name
, old_master
);
3368 ret
= dlm_do_assert_master(dlm
, res
, iter
.node_map
,
3369 DLM_ASSERT_MASTER_FINISH_MIGRATION
);
3371 mlog(0, "assert master to original master failed "
3373 /* the only nonzero status here would be because of
3374 * a dead original node. we're done. */
3378 /* all done, set the owner, clear the flag */
3379 spin_lock(&res
->spinlock
);
3380 dlm_set_lockres_owner(dlm
, res
, dlm
->node_num
);
3381 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
3382 spin_unlock(&res
->spinlock
);
3383 /* re-dirty it on the new master */
3384 dlm_kick_thread(dlm
, res
);
3391 * LOCKRES AST REFCOUNT
3392 * this is integral to migration
3395 /* for future intent to call an ast, reserve one ahead of time.
3396 * this should be called only after waiting on the lockres
3397 * with dlm_wait_on_lockres, and while still holding the
3398 * spinlock after the call. */
3399 void __dlm_lockres_reserve_ast(struct dlm_lock_resource
*res
)
3401 assert_spin_locked(&res
->spinlock
);
3402 if (res
->state
& DLM_LOCK_RES_MIGRATING
) {
3403 __dlm_print_one_lock_resource(res
);
3405 BUG_ON(res
->state
& DLM_LOCK_RES_MIGRATING
);
3407 atomic_inc(&res
->asts_reserved
);
3411 * used to drop the reserved ast, either because it went unused,
3412 * or because the ast/bast was actually called.
3414 * also, if there is a pending migration on this lockres,
3415 * and this was the last pending ast on the lockres,
3416 * atomically set the MIGRATING flag before we drop the lock.
3417 * this is how we ensure that migration can proceed with no
3418 * asts in progress. note that it is ok if the state of the
3419 * queues is such that a lock should be granted in the future
3420 * or that a bast should be fired, because the new master will
3421 * shuffle the lists on this lockres as soon as it is migrated.
3423 void dlm_lockres_release_ast(struct dlm_ctxt
*dlm
,
3424 struct dlm_lock_resource
*res
)
3426 if (!atomic_dec_and_lock(&res
->asts_reserved
, &res
->spinlock
))
3429 if (!res
->migration_pending
) {
3430 spin_unlock(&res
->spinlock
);
3434 BUG_ON(res
->state
& DLM_LOCK_RES_MIGRATING
);
3435 res
->migration_pending
= 0;
3436 res
->state
|= DLM_LOCK_RES_MIGRATING
;
3437 spin_unlock(&res
->spinlock
);
3439 wake_up(&dlm
->migration_wq
);