1 /* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
6 * standalone DLM module
8 * Copyright (C) 2004 Oracle. All rights reserved.
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public
12 * License as published by the Free Software Foundation; either
13 * version 2 of the License, or (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
20 * You should have received a copy of the GNU General Public
21 * License along with this program; if not, write to the
22 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 * Boston, MA 021110-1307, USA.
28 #include <linux/module.h>
30 #include <linux/types.h>
31 #include <linux/slab.h>
32 #include <linux/highmem.h>
33 #include <linux/utsname.h>
34 #include <linux/init.h>
35 #include <linux/sysctl.h>
36 #include <linux/random.h>
37 #include <linux/blkdev.h>
38 #include <linux/socket.h>
39 #include <linux/inet.h>
40 #include <linux/spinlock.h>
41 #include <linux/delay.h>
44 #include "cluster/heartbeat.h"
45 #include "cluster/nodemanager.h"
46 #include "cluster/tcp.h"
49 #include "dlmcommon.h"
51 #include "dlmdomain.h"
53 #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_MASTER)
54 #include "cluster/masklog.h"
65 u8 name
[DLM_LOCKID_NAME_MAX
];
68 struct dlm_master_list_entry
70 struct list_head list
;
71 struct list_head hb_events
;
78 unsigned long maybe_map
[BITS_TO_LONGS(O2NM_MAX_NODES
)];
79 unsigned long vote_map
[BITS_TO_LONGS(O2NM_MAX_NODES
)];
80 unsigned long response_map
[BITS_TO_LONGS(O2NM_MAX_NODES
)];
81 unsigned long node_map
[BITS_TO_LONGS(O2NM_MAX_NODES
)];
84 enum dlm_mle_type type
;
85 struct o2hb_callback_func mle_hb_up
;
86 struct o2hb_callback_func mle_hb_down
;
88 struct dlm_lock_resource
*res
;
89 struct dlm_lock_name name
;
93 static void dlm_mle_node_down(struct dlm_ctxt
*dlm
,
94 struct dlm_master_list_entry
*mle
,
95 struct o2nm_node
*node
,
97 static void dlm_mle_node_up(struct dlm_ctxt
*dlm
,
98 struct dlm_master_list_entry
*mle
,
99 struct o2nm_node
*node
,
102 static void dlm_assert_master_worker(struct dlm_work_item
*item
, void *data
);
103 static int dlm_do_assert_master(struct dlm_ctxt
*dlm
, const char *lockname
,
104 unsigned int namelen
, void *nodemap
,
107 static inline int dlm_mle_equal(struct dlm_ctxt
*dlm
,
108 struct dlm_master_list_entry
*mle
,
110 unsigned int namelen
)
112 struct dlm_lock_resource
*res
;
117 if (mle
->type
== DLM_MLE_BLOCK
||
118 mle
->type
== DLM_MLE_MIGRATION
) {
119 if (namelen
!= mle
->u
.name
.len
||
120 memcmp(name
, mle
->u
.name
.name
, namelen
)!=0)
124 if (namelen
!= res
->lockname
.len
||
125 memcmp(res
->lockname
.name
, name
, namelen
) != 0)
132 /* Code here is included but defined out as it aids debugging */
134 #define dlm_print_nodemap(m) _dlm_print_nodemap(m,#m)
135 void _dlm_print_nodemap(unsigned long *map
, const char *mapname
)
138 printk("%s=[ ", mapname
);
139 for (i
=0; i
<O2NM_MAX_NODES
; i
++)
140 if (test_bit(i
, map
))
145 void dlm_print_one_mle(struct dlm_master_list_entry
*mle
)
151 unsigned int namelen
;
154 unsigned long *maybe
= mle
->maybe_map
,
155 *vote
= mle
->vote_map
,
156 *resp
= mle
->response_map
,
157 *node
= mle
->node_map
;
160 if (mle
->type
== DLM_MLE_BLOCK
)
162 else if (mle
->type
== DLM_MLE_MASTER
)
166 refs
= atomic_read(&k
->refcount
);
167 master
= mle
->master
;
168 attached
= (list_empty(&mle
->hb_events
) ? 'N' : 'Y');
170 if (mle
->type
!= DLM_MLE_MASTER
) {
171 namelen
= mle
->u
.name
.len
;
172 name
= mle
->u
.name
.name
;
174 namelen
= mle
->u
.res
->lockname
.len
;
175 name
= mle
->u
.res
->lockname
.name
;
178 mlog(ML_NOTICE
, "%.*s: %3s refs=%3d mas=%3u new=%3u evt=%c inuse=%d ",
179 namelen
, name
, type
, refs
, master
, mle
->new_master
, attached
,
181 dlm_print_nodemap(maybe
);
183 dlm_print_nodemap(vote
);
185 dlm_print_nodemap(resp
);
187 dlm_print_nodemap(node
);
192 static void dlm_dump_mles(struct dlm_ctxt
*dlm
)
194 struct dlm_master_list_entry
*mle
;
195 struct list_head
*iter
;
197 mlog(ML_NOTICE
, "dumping all mles for domain %s:\n", dlm
->name
);
198 spin_lock(&dlm
->master_lock
);
199 list_for_each(iter
, &dlm
->master_list
) {
200 mle
= list_entry(iter
, struct dlm_master_list_entry
, list
);
201 dlm_print_one_mle(mle
);
203 spin_unlock(&dlm
->master_lock
);
206 int dlm_dump_all_mles(const char __user
*data
, unsigned int len
)
208 struct list_head
*iter
;
209 struct dlm_ctxt
*dlm
;
211 spin_lock(&dlm_domain_lock
);
212 list_for_each(iter
, &dlm_domains
) {
213 dlm
= list_entry (iter
, struct dlm_ctxt
, list
);
214 mlog(ML_NOTICE
, "found dlm: %p, name=%s\n", dlm
, dlm
->name
);
217 spin_unlock(&dlm_domain_lock
);
220 EXPORT_SYMBOL_GPL(dlm_dump_all_mles
);
225 static kmem_cache_t
*dlm_mle_cache
= NULL
;
228 static void dlm_mle_release(struct kref
*kref
);
229 static void dlm_init_mle(struct dlm_master_list_entry
*mle
,
230 enum dlm_mle_type type
,
231 struct dlm_ctxt
*dlm
,
232 struct dlm_lock_resource
*res
,
234 unsigned int namelen
);
235 static void dlm_put_mle(struct dlm_master_list_entry
*mle
);
236 static void __dlm_put_mle(struct dlm_master_list_entry
*mle
);
237 static int dlm_find_mle(struct dlm_ctxt
*dlm
,
238 struct dlm_master_list_entry
**mle
,
239 char *name
, unsigned int namelen
);
241 static int dlm_do_master_request(struct dlm_master_list_entry
*mle
, int to
);
244 static int dlm_wait_for_lock_mastery(struct dlm_ctxt
*dlm
,
245 struct dlm_lock_resource
*res
,
246 struct dlm_master_list_entry
*mle
,
248 static int dlm_restart_lock_mastery(struct dlm_ctxt
*dlm
,
249 struct dlm_lock_resource
*res
,
250 struct dlm_master_list_entry
*mle
,
252 static int dlm_add_migration_mle(struct dlm_ctxt
*dlm
,
253 struct dlm_lock_resource
*res
,
254 struct dlm_master_list_entry
*mle
,
255 struct dlm_master_list_entry
**oldmle
,
256 const char *name
, unsigned int namelen
,
257 u8 new_master
, u8 master
);
259 static u8
dlm_pick_migration_target(struct dlm_ctxt
*dlm
,
260 struct dlm_lock_resource
*res
);
261 static void dlm_remove_nonlocal_locks(struct dlm_ctxt
*dlm
,
262 struct dlm_lock_resource
*res
);
263 static int dlm_mark_lockres_migrating(struct dlm_ctxt
*dlm
,
264 struct dlm_lock_resource
*res
,
266 static int dlm_pre_master_reco_lockres(struct dlm_ctxt
*dlm
,
267 struct dlm_lock_resource
*res
);
270 int dlm_is_host_down(int errno
)
287 case -EINVAL
: /* if returned from our tcp code,
288 this means there is no socket */
296 * MASTER LIST FUNCTIONS
301 * regarding master list entries and heartbeat callbacks:
303 * in order to avoid sleeping and allocation that occurs in
304 * heartbeat, master list entries are simply attached to the
305 * dlm's established heartbeat callbacks. the mle is attached
306 * when it is created, and since the dlm->spinlock is held at
307 * that time, any heartbeat event will be properly discovered
308 * by the mle. the mle needs to be detached from the
309 * dlm->mle_hb_events list as soon as heartbeat events are no
310 * longer useful to the mle, and before the mle is freed.
312 * as a general rule, heartbeat events are no longer needed by
313 * the mle once an "answer" regarding the lock master has been
316 static inline void __dlm_mle_attach_hb_events(struct dlm_ctxt
*dlm
,
317 struct dlm_master_list_entry
*mle
)
319 assert_spin_locked(&dlm
->spinlock
);
321 list_add_tail(&mle
->hb_events
, &dlm
->mle_hb_events
);
325 static inline void __dlm_mle_detach_hb_events(struct dlm_ctxt
*dlm
,
326 struct dlm_master_list_entry
*mle
)
328 if (!list_empty(&mle
->hb_events
))
329 list_del_init(&mle
->hb_events
);
333 static inline void dlm_mle_detach_hb_events(struct dlm_ctxt
*dlm
,
334 struct dlm_master_list_entry
*mle
)
336 spin_lock(&dlm
->spinlock
);
337 __dlm_mle_detach_hb_events(dlm
, mle
);
338 spin_unlock(&dlm
->spinlock
);
341 static void dlm_get_mle_inuse(struct dlm_master_list_entry
*mle
)
343 struct dlm_ctxt
*dlm
;
346 assert_spin_locked(&dlm
->spinlock
);
347 assert_spin_locked(&dlm
->master_lock
);
349 kref_get(&mle
->mle_refs
);
352 static void dlm_put_mle_inuse(struct dlm_master_list_entry
*mle
)
354 struct dlm_ctxt
*dlm
;
357 spin_lock(&dlm
->spinlock
);
358 spin_lock(&dlm
->master_lock
);
361 spin_unlock(&dlm
->master_lock
);
362 spin_unlock(&dlm
->spinlock
);
366 /* remove from list and free */
367 static void __dlm_put_mle(struct dlm_master_list_entry
*mle
)
369 struct dlm_ctxt
*dlm
;
372 assert_spin_locked(&dlm
->spinlock
);
373 assert_spin_locked(&dlm
->master_lock
);
374 if (!atomic_read(&mle
->mle_refs
.refcount
)) {
375 /* this may or may not crash, but who cares.
377 mlog(ML_ERROR
, "bad mle: %p\n", mle
);
378 dlm_print_one_mle(mle
);
381 kref_put(&mle
->mle_refs
, dlm_mle_release
);
385 /* must not have any spinlocks coming in */
386 static void dlm_put_mle(struct dlm_master_list_entry
*mle
)
388 struct dlm_ctxt
*dlm
;
391 spin_lock(&dlm
->spinlock
);
392 spin_lock(&dlm
->master_lock
);
394 spin_unlock(&dlm
->master_lock
);
395 spin_unlock(&dlm
->spinlock
);
398 static inline void dlm_get_mle(struct dlm_master_list_entry
*mle
)
400 kref_get(&mle
->mle_refs
);
403 static void dlm_init_mle(struct dlm_master_list_entry
*mle
,
404 enum dlm_mle_type type
,
405 struct dlm_ctxt
*dlm
,
406 struct dlm_lock_resource
*res
,
408 unsigned int namelen
)
410 assert_spin_locked(&dlm
->spinlock
);
414 INIT_LIST_HEAD(&mle
->list
);
415 INIT_LIST_HEAD(&mle
->hb_events
);
416 memset(mle
->maybe_map
, 0, sizeof(mle
->maybe_map
));
417 spin_lock_init(&mle
->spinlock
);
418 init_waitqueue_head(&mle
->wq
);
419 atomic_set(&mle
->woken
, 0);
420 kref_init(&mle
->mle_refs
);
421 memset(mle
->response_map
, 0, sizeof(mle
->response_map
));
422 mle
->master
= O2NM_MAX_NODES
;
423 mle
->new_master
= O2NM_MAX_NODES
;
426 if (mle
->type
== DLM_MLE_MASTER
) {
429 } else if (mle
->type
== DLM_MLE_BLOCK
) {
431 memcpy(mle
->u
.name
.name
, name
, namelen
);
432 mle
->u
.name
.len
= namelen
;
433 } else /* DLM_MLE_MIGRATION */ {
435 memcpy(mle
->u
.name
.name
, name
, namelen
);
436 mle
->u
.name
.len
= namelen
;
439 /* copy off the node_map and register hb callbacks on our copy */
440 memcpy(mle
->node_map
, dlm
->domain_map
, sizeof(mle
->node_map
));
441 memcpy(mle
->vote_map
, dlm
->domain_map
, sizeof(mle
->vote_map
));
442 clear_bit(dlm
->node_num
, mle
->vote_map
);
443 clear_bit(dlm
->node_num
, mle
->node_map
);
445 /* attach the mle to the domain node up/down events */
446 __dlm_mle_attach_hb_events(dlm
, mle
);
450 /* returns 1 if found, 0 if not */
451 static int dlm_find_mle(struct dlm_ctxt
*dlm
,
452 struct dlm_master_list_entry
**mle
,
453 char *name
, unsigned int namelen
)
455 struct dlm_master_list_entry
*tmpmle
;
456 struct list_head
*iter
;
458 assert_spin_locked(&dlm
->master_lock
);
460 list_for_each(iter
, &dlm
->master_list
) {
461 tmpmle
= list_entry(iter
, struct dlm_master_list_entry
, list
);
462 if (!dlm_mle_equal(dlm
, tmpmle
, name
, namelen
))
471 void dlm_hb_event_notify_attached(struct dlm_ctxt
*dlm
, int idx
, int node_up
)
473 struct dlm_master_list_entry
*mle
;
474 struct list_head
*iter
;
476 assert_spin_locked(&dlm
->spinlock
);
478 list_for_each(iter
, &dlm
->mle_hb_events
) {
479 mle
= list_entry(iter
, struct dlm_master_list_entry
,
482 dlm_mle_node_up(dlm
, mle
, NULL
, idx
);
484 dlm_mle_node_down(dlm
, mle
, NULL
, idx
);
488 static void dlm_mle_node_down(struct dlm_ctxt
*dlm
,
489 struct dlm_master_list_entry
*mle
,
490 struct o2nm_node
*node
, int idx
)
492 spin_lock(&mle
->spinlock
);
494 if (!test_bit(idx
, mle
->node_map
))
495 mlog(0, "node %u already removed from nodemap!\n", idx
);
497 clear_bit(idx
, mle
->node_map
);
499 spin_unlock(&mle
->spinlock
);
502 static void dlm_mle_node_up(struct dlm_ctxt
*dlm
,
503 struct dlm_master_list_entry
*mle
,
504 struct o2nm_node
*node
, int idx
)
506 spin_lock(&mle
->spinlock
);
508 if (test_bit(idx
, mle
->node_map
))
509 mlog(0, "node %u already in node map!\n", idx
);
511 set_bit(idx
, mle
->node_map
);
513 spin_unlock(&mle
->spinlock
);
517 int dlm_init_mle_cache(void)
519 dlm_mle_cache
= kmem_cache_create("dlm_mle_cache",
520 sizeof(struct dlm_master_list_entry
),
521 0, SLAB_HWCACHE_ALIGN
,
523 if (dlm_mle_cache
== NULL
)
528 void dlm_destroy_mle_cache(void)
531 kmem_cache_destroy(dlm_mle_cache
);
534 static void dlm_mle_release(struct kref
*kref
)
536 struct dlm_master_list_entry
*mle
;
537 struct dlm_ctxt
*dlm
;
541 mle
= container_of(kref
, struct dlm_master_list_entry
, mle_refs
);
544 if (mle
->type
!= DLM_MLE_MASTER
) {
545 mlog(0, "calling mle_release for %.*s, type %d\n",
546 mle
->u
.name
.len
, mle
->u
.name
.name
, mle
->type
);
548 mlog(0, "calling mle_release for %.*s, type %d\n",
549 mle
->u
.res
->lockname
.len
,
550 mle
->u
.res
->lockname
.name
, mle
->type
);
552 assert_spin_locked(&dlm
->spinlock
);
553 assert_spin_locked(&dlm
->master_lock
);
555 /* remove from list if not already */
556 if (!list_empty(&mle
->list
))
557 list_del_init(&mle
->list
);
559 /* detach the mle from the domain node up/down events */
560 __dlm_mle_detach_hb_events(dlm
, mle
);
562 /* NOTE: kfree under spinlock here.
563 * if this is bad, we can move this to a freelist. */
564 kmem_cache_free(dlm_mle_cache
, mle
);
569 * LOCK RESOURCE FUNCTIONS
572 static void dlm_set_lockres_owner(struct dlm_ctxt
*dlm
,
573 struct dlm_lock_resource
*res
,
576 assert_spin_locked(&res
->spinlock
);
578 mlog_entry("%.*s, %u\n", res
->lockname
.len
, res
->lockname
.name
, owner
);
580 if (owner
== dlm
->node_num
)
581 atomic_inc(&dlm
->local_resources
);
582 else if (owner
== DLM_LOCK_RES_OWNER_UNKNOWN
)
583 atomic_inc(&dlm
->unknown_resources
);
585 atomic_inc(&dlm
->remote_resources
);
590 void dlm_change_lockres_owner(struct dlm_ctxt
*dlm
,
591 struct dlm_lock_resource
*res
, u8 owner
)
593 assert_spin_locked(&res
->spinlock
);
595 if (owner
== res
->owner
)
598 if (res
->owner
== dlm
->node_num
)
599 atomic_dec(&dlm
->local_resources
);
600 else if (res
->owner
== DLM_LOCK_RES_OWNER_UNKNOWN
)
601 atomic_dec(&dlm
->unknown_resources
);
603 atomic_dec(&dlm
->remote_resources
);
605 dlm_set_lockres_owner(dlm
, res
, owner
);
609 static void dlm_lockres_release(struct kref
*kref
)
611 struct dlm_lock_resource
*res
;
613 res
= container_of(kref
, struct dlm_lock_resource
, refs
);
615 /* This should not happen -- all lockres' have a name
616 * associated with them at init time. */
617 BUG_ON(!res
->lockname
.name
);
619 mlog(0, "destroying lockres %.*s\n", res
->lockname
.len
,
622 if (!hlist_unhashed(&res
->hash_node
) ||
623 !list_empty(&res
->granted
) ||
624 !list_empty(&res
->converting
) ||
625 !list_empty(&res
->blocked
) ||
626 !list_empty(&res
->dirty
) ||
627 !list_empty(&res
->recovering
) ||
628 !list_empty(&res
->purge
)) {
630 "Going to BUG for resource %.*s."
631 " We're on a list! [%c%c%c%c%c%c%c]\n",
632 res
->lockname
.len
, res
->lockname
.name
,
633 !hlist_unhashed(&res
->hash_node
) ? 'H' : ' ',
634 !list_empty(&res
->granted
) ? 'G' : ' ',
635 !list_empty(&res
->converting
) ? 'C' : ' ',
636 !list_empty(&res
->blocked
) ? 'B' : ' ',
637 !list_empty(&res
->dirty
) ? 'D' : ' ',
638 !list_empty(&res
->recovering
) ? 'R' : ' ',
639 !list_empty(&res
->purge
) ? 'P' : ' ');
641 dlm_print_one_lock_resource(res
);
644 /* By the time we're ready to blow this guy away, we shouldn't
645 * be on any lists. */
646 BUG_ON(!hlist_unhashed(&res
->hash_node
));
647 BUG_ON(!list_empty(&res
->granted
));
648 BUG_ON(!list_empty(&res
->converting
));
649 BUG_ON(!list_empty(&res
->blocked
));
650 BUG_ON(!list_empty(&res
->dirty
));
651 BUG_ON(!list_empty(&res
->recovering
));
652 BUG_ON(!list_empty(&res
->purge
));
654 kfree(res
->lockname
.name
);
659 void dlm_lockres_put(struct dlm_lock_resource
*res
)
661 kref_put(&res
->refs
, dlm_lockres_release
);
664 static void dlm_init_lockres(struct dlm_ctxt
*dlm
,
665 struct dlm_lock_resource
*res
,
666 const char *name
, unsigned int namelen
)
670 /* If we memset here, we lose our reference to the kmalloc'd
671 * res->lockname.name, so be sure to init every field
674 qname
= (char *) res
->lockname
.name
;
675 memcpy(qname
, name
, namelen
);
677 res
->lockname
.len
= namelen
;
678 res
->lockname
.hash
= dlm_lockid_hash(name
, namelen
);
680 init_waitqueue_head(&res
->wq
);
681 spin_lock_init(&res
->spinlock
);
682 INIT_HLIST_NODE(&res
->hash_node
);
683 INIT_LIST_HEAD(&res
->granted
);
684 INIT_LIST_HEAD(&res
->converting
);
685 INIT_LIST_HEAD(&res
->blocked
);
686 INIT_LIST_HEAD(&res
->dirty
);
687 INIT_LIST_HEAD(&res
->recovering
);
688 INIT_LIST_HEAD(&res
->purge
);
689 atomic_set(&res
->asts_reserved
, 0);
690 res
->migration_pending
= 0;
692 kref_init(&res
->refs
);
694 /* just for consistency */
695 spin_lock(&res
->spinlock
);
696 dlm_set_lockres_owner(dlm
, res
, DLM_LOCK_RES_OWNER_UNKNOWN
);
697 spin_unlock(&res
->spinlock
);
699 res
->state
= DLM_LOCK_RES_IN_PROGRESS
;
703 memset(res
->lvb
, 0, DLM_LVB_LEN
);
706 struct dlm_lock_resource
*dlm_new_lockres(struct dlm_ctxt
*dlm
,
708 unsigned int namelen
)
710 struct dlm_lock_resource
*res
;
712 res
= kmalloc(sizeof(struct dlm_lock_resource
), GFP_NOFS
);
716 res
->lockname
.name
= kmalloc(namelen
, GFP_NOFS
);
717 if (!res
->lockname
.name
) {
722 dlm_init_lockres(dlm
, res
, name
, namelen
);
727 * lookup a lock resource by name.
728 * may already exist in the hashtable.
729 * lockid is null terminated
731 * if not, allocate enough for the lockres and for
732 * the temporary structure used in doing the mastering.
734 * also, do a lookup in the dlm->master_list to see
735 * if another node has begun mastering the same lock.
736 * if so, there should be a block entry in there
737 * for this name, and we should *not* attempt to master
738 * the lock here. need to wait around for that node
739 * to assert_master (or die).
742 struct dlm_lock_resource
* dlm_get_lock_resource(struct dlm_ctxt
*dlm
,
746 struct dlm_lock_resource
*tmpres
=NULL
, *res
=NULL
;
747 struct dlm_master_list_entry
*mle
= NULL
;
748 struct dlm_master_list_entry
*alloc_mle
= NULL
;
751 struct dlm_node_iter iter
;
752 unsigned int namelen
, hash
;
754 int bit
, wait_on_recovery
= 0;
758 namelen
= strlen(lockid
);
759 hash
= dlm_lockid_hash(lockid
, namelen
);
761 mlog(0, "get lockres %s (len %d)\n", lockid
, namelen
);
764 spin_lock(&dlm
->spinlock
);
765 tmpres
= __dlm_lookup_lockres(dlm
, lockid
, namelen
, hash
);
767 spin_unlock(&dlm
->spinlock
);
768 mlog(0, "found in hash!\n");
770 dlm_lockres_put(res
);
776 spin_unlock(&dlm
->spinlock
);
777 mlog(0, "allocating a new resource\n");
778 /* nothing found and we need to allocate one. */
779 alloc_mle
= (struct dlm_master_list_entry
*)
780 kmem_cache_alloc(dlm_mle_cache
, GFP_NOFS
);
783 res
= dlm_new_lockres(dlm
, lockid
, namelen
);
789 mlog(0, "no lockres found, allocated our own: %p\n", res
);
791 if (flags
& LKM_LOCAL
) {
792 /* caller knows it's safe to assume it's not mastered elsewhere
793 * DONE! return right away */
794 spin_lock(&res
->spinlock
);
795 dlm_change_lockres_owner(dlm
, res
, dlm
->node_num
);
796 __dlm_insert_lockres(dlm
, res
);
797 spin_unlock(&res
->spinlock
);
798 spin_unlock(&dlm
->spinlock
);
799 /* lockres still marked IN_PROGRESS */
803 /* check master list to see if another node has started mastering it */
804 spin_lock(&dlm
->master_lock
);
806 /* if we found a block, wait for lock to be mastered by another node */
807 blocked
= dlm_find_mle(dlm
, &mle
, (char *)lockid
, namelen
);
809 if (mle
->type
== DLM_MLE_MASTER
) {
810 mlog(ML_ERROR
, "master entry for nonexistent lock!\n");
812 } else if (mle
->type
== DLM_MLE_MIGRATION
) {
813 /* migration is in progress! */
814 /* the good news is that we now know the
815 * "current" master (mle->master). */
817 spin_unlock(&dlm
->master_lock
);
818 assert_spin_locked(&dlm
->spinlock
);
820 /* set the lockres owner and hash it */
821 spin_lock(&res
->spinlock
);
822 dlm_set_lockres_owner(dlm
, res
, mle
->master
);
823 __dlm_insert_lockres(dlm
, res
);
824 spin_unlock(&res
->spinlock
);
825 spin_unlock(&dlm
->spinlock
);
827 /* master is known, detach */
828 dlm_mle_detach_hb_events(dlm
, mle
);
834 /* go ahead and try to master lock on this node */
836 /* make sure this does not get freed below */
838 dlm_init_mle(mle
, DLM_MLE_MASTER
, dlm
, res
, NULL
, 0);
839 set_bit(dlm
->node_num
, mle
->maybe_map
);
840 list_add(&mle
->list
, &dlm
->master_list
);
842 /* still holding the dlm spinlock, check the recovery map
843 * to see if there are any nodes that still need to be
844 * considered. these will not appear in the mle nodemap
845 * but they might own this lockres. wait on them. */
846 bit
= find_next_bit(dlm
->recovery_map
, O2NM_MAX_NODES
, 0);
847 if (bit
< O2NM_MAX_NODES
) {
848 mlog(ML_NOTICE
, "%s:%.*s: at least one node (%d) to"
849 "recover before lock mastery can begin\n",
850 dlm
->name
, namelen
, (char *)lockid
, bit
);
851 wait_on_recovery
= 1;
855 /* at this point there is either a DLM_MLE_BLOCK or a
856 * DLM_MLE_MASTER on the master list, so it's safe to add the
857 * lockres to the hashtable. anyone who finds the lock will
858 * still have to wait on the IN_PROGRESS. */
860 /* finally add the lockres to its hash bucket */
861 __dlm_insert_lockres(dlm
, res
);
862 /* get an extra ref on the mle in case this is a BLOCK
863 * if so, the creator of the BLOCK may try to put the last
864 * ref at this time in the assert master handler, so we
865 * need an extra one to keep from a bad ptr deref. */
866 dlm_get_mle_inuse(mle
);
867 spin_unlock(&dlm
->master_lock
);
868 spin_unlock(&dlm
->spinlock
);
871 while (wait_on_recovery
) {
872 /* any cluster changes that occurred after dropping the
873 * dlm spinlock would be detectable be a change on the mle,
874 * so we only need to clear out the recovery map once. */
875 if (dlm_is_recovery_lock(lockid
, namelen
)) {
876 mlog(ML_NOTICE
, "%s: recovery map is not empty, but "
877 "must master $RECOVERY lock now\n", dlm
->name
);
878 if (!dlm_pre_master_reco_lockres(dlm
, res
))
879 wait_on_recovery
= 0;
881 mlog(0, "%s: waiting 500ms for heartbeat state "
882 "change\n", dlm
->name
);
888 dlm_kick_recovery_thread(dlm
);
890 dlm_wait_for_recovery(dlm
);
892 spin_lock(&dlm
->spinlock
);
893 bit
= find_next_bit(dlm
->recovery_map
, O2NM_MAX_NODES
, 0);
894 if (bit
< O2NM_MAX_NODES
) {
895 mlog(ML_NOTICE
, "%s:%.*s: at least one node (%d) to"
896 "recover before lock mastery can begin\n",
897 dlm
->name
, namelen
, (char *)lockid
, bit
);
898 wait_on_recovery
= 1;
900 wait_on_recovery
= 0;
901 spin_unlock(&dlm
->spinlock
);
903 if (wait_on_recovery
)
904 dlm_wait_for_node_recovery(dlm
, bit
, 10000);
907 /* must wait for lock to be mastered elsewhere */
912 dlm_node_iter_init(mle
->vote_map
, &iter
);
913 while ((nodenum
= dlm_node_iter_next(&iter
)) >= 0) {
914 ret
= dlm_do_master_request(mle
, nodenum
);
917 if (mle
->master
!= O2NM_MAX_NODES
) {
918 /* found a master ! */
919 if (mle
->master
<= nodenum
)
921 /* if our master request has not reached the master
922 * yet, keep going until it does. this is how the
923 * master will know that asserts are needed back to
924 * the lower nodes. */
925 mlog(0, "%s:%.*s: requests only up to %u but master "
926 "is %u, keep going\n", dlm
->name
, namelen
,
927 lockid
, nodenum
, mle
->master
);
932 /* keep going until the response map includes all nodes */
933 ret
= dlm_wait_for_lock_mastery(dlm
, res
, mle
, &blocked
);
935 wait_on_recovery
= 1;
936 mlog(0, "%s:%.*s: node map changed, redo the "
937 "master request now, blocked=%d\n",
938 dlm
->name
, res
->lockname
.len
,
939 res
->lockname
.name
, blocked
);
941 mlog(ML_ERROR
, "%s:%.*s: spinning on "
942 "dlm_wait_for_lock_mastery, blocked=%d\n",
943 dlm
->name
, res
->lockname
.len
,
944 res
->lockname
.name
, blocked
);
945 dlm_print_one_lock_resource(res
);
946 /* dlm_print_one_mle(mle); */
952 mlog(0, "lockres mastered by %u\n", res
->owner
);
953 /* make sure we never continue without this */
954 BUG_ON(res
->owner
== O2NM_MAX_NODES
);
956 /* master is known, detach if not already detached */
957 dlm_mle_detach_hb_events(dlm
, mle
);
959 /* put the extra ref */
960 dlm_put_mle_inuse(mle
);
963 spin_lock(&res
->spinlock
);
964 res
->state
&= ~DLM_LOCK_RES_IN_PROGRESS
;
965 spin_unlock(&res
->spinlock
);
969 /* need to free the unused mle */
971 kmem_cache_free(dlm_mle_cache
, alloc_mle
);
977 #define DLM_MASTERY_TIMEOUT_MS 5000
979 static int dlm_wait_for_lock_mastery(struct dlm_ctxt
*dlm
,
980 struct dlm_lock_resource
*res
,
981 struct dlm_master_list_entry
*mle
,
986 int map_changed
, voting_done
;
993 /* check if another node has already become the owner */
994 spin_lock(&res
->spinlock
);
995 if (res
->owner
!= DLM_LOCK_RES_OWNER_UNKNOWN
) {
996 mlog(0, "%s:%.*s: owner is suddenly %u\n", dlm
->name
,
997 res
->lockname
.len
, res
->lockname
.name
, res
->owner
);
998 spin_unlock(&res
->spinlock
);
999 /* this will cause the master to re-assert across
1000 * the whole cluster, freeing up mles */
1001 if (res
->owner
!= dlm
->node_num
) {
1002 ret
= dlm_do_master_request(mle
, res
->owner
);
1004 /* give recovery a chance to run */
1005 mlog(ML_ERROR
, "link to %u went down?: %d\n", res
->owner
, ret
);
1013 spin_unlock(&res
->spinlock
);
1015 spin_lock(&mle
->spinlock
);
1017 map_changed
= (memcmp(mle
->vote_map
, mle
->node_map
,
1018 sizeof(mle
->vote_map
)) != 0);
1019 voting_done
= (memcmp(mle
->vote_map
, mle
->response_map
,
1020 sizeof(mle
->vote_map
)) == 0);
1022 /* restart if we hit any errors */
1025 mlog(0, "%s: %.*s: node map changed, restarting\n",
1026 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
);
1027 ret
= dlm_restart_lock_mastery(dlm
, res
, mle
, *blocked
);
1028 b
= (mle
->type
== DLM_MLE_BLOCK
);
1029 if ((*blocked
&& !b
) || (!*blocked
&& b
)) {
1030 mlog(0, "%s:%.*s: status change: old=%d new=%d\n",
1031 dlm
->name
, res
->lockname
.len
, res
->lockname
.name
,
1035 spin_unlock(&mle
->spinlock
);
1040 mlog(0, "%s:%.*s: restart lock mastery succeeded, "
1041 "rechecking now\n", dlm
->name
, res
->lockname
.len
,
1042 res
->lockname
.name
);
1046 mlog(0, "map not changed and voting not done "
1047 "for %s:%.*s\n", dlm
->name
, res
->lockname
.len
,
1048 res
->lockname
.name
);
1052 if (m
!= O2NM_MAX_NODES
) {
1053 /* another node has done an assert!
1058 /* have all nodes responded? */
1059 if (voting_done
&& !*blocked
) {
1060 bit
= find_next_bit(mle
->maybe_map
, O2NM_MAX_NODES
, 0);
1061 if (dlm
->node_num
<= bit
) {
1062 /* my node number is lowest.
1063 * now tell other nodes that I am
1064 * mastering this. */
1065 mle
->master
= dlm
->node_num
;
1069 /* if voting is done, but we have not received
1070 * an assert master yet, we must sleep */
1074 spin_unlock(&mle
->spinlock
);
1076 /* sleep if we haven't finished voting yet */
1078 unsigned long timeo
= msecs_to_jiffies(DLM_MASTERY_TIMEOUT_MS
);
1081 if (atomic_read(&mle->mle_refs.refcount) < 2)
1082 mlog(ML_ERROR, "mle (%p) refs=%d, name=%.*s\n", mle,
1083 atomic_read(&mle->mle_refs.refcount),
1084 res->lockname.len, res->lockname.name);
1086 atomic_set(&mle
->woken
, 0);
1087 (void)wait_event_timeout(mle
->wq
,
1088 (atomic_read(&mle
->woken
) == 1),
1090 if (res
->owner
== O2NM_MAX_NODES
) {
1091 mlog(0, "waiting again\n");
1094 mlog(0, "done waiting, master is %u\n", res
->owner
);
1102 mlog(0, "about to master %.*s here, this=%u\n",
1103 res
->lockname
.len
, res
->lockname
.name
, m
);
1104 ret
= dlm_do_assert_master(dlm
, res
->lockname
.name
,
1105 res
->lockname
.len
, mle
->vote_map
, 0);
1107 /* This is a failure in the network path,
1108 * not in the response to the assert_master
1109 * (any nonzero response is a BUG on this node).
1110 * Most likely a socket just got disconnected
1111 * due to node death. */
1114 /* no longer need to restart lock mastery.
1115 * all living nodes have been contacted. */
1119 /* set the lockres owner */
1120 spin_lock(&res
->spinlock
);
1121 dlm_change_lockres_owner(dlm
, res
, m
);
1122 spin_unlock(&res
->spinlock
);
1128 struct dlm_bitmap_diff_iter
1131 unsigned long *orig_bm
;
1132 unsigned long *cur_bm
;
1133 unsigned long diff_bm
[BITS_TO_LONGS(O2NM_MAX_NODES
)];
1136 enum dlm_node_state_change
1143 static void dlm_bitmap_diff_iter_init(struct dlm_bitmap_diff_iter
*iter
,
1144 unsigned long *orig_bm
,
1145 unsigned long *cur_bm
)
1147 unsigned long p1
, p2
;
1151 iter
->orig_bm
= orig_bm
;
1152 iter
->cur_bm
= cur_bm
;
1154 for (i
= 0; i
< BITS_TO_LONGS(O2NM_MAX_NODES
); i
++) {
1155 p1
= *(iter
->orig_bm
+ i
);
1156 p2
= *(iter
->cur_bm
+ i
);
1157 iter
->diff_bm
[i
] = (p1
& ~p2
) | (p2
& ~p1
);
1161 static int dlm_bitmap_diff_iter_next(struct dlm_bitmap_diff_iter
*iter
,
1162 enum dlm_node_state_change
*state
)
1166 if (iter
->curnode
>= O2NM_MAX_NODES
)
1169 bit
= find_next_bit(iter
->diff_bm
, O2NM_MAX_NODES
,
1171 if (bit
>= O2NM_MAX_NODES
) {
1172 iter
->curnode
= O2NM_MAX_NODES
;
1176 /* if it was there in the original then this node died */
1177 if (test_bit(bit
, iter
->orig_bm
))
1182 iter
->curnode
= bit
;
1187 static int dlm_restart_lock_mastery(struct dlm_ctxt
*dlm
,
1188 struct dlm_lock_resource
*res
,
1189 struct dlm_master_list_entry
*mle
,
1192 struct dlm_bitmap_diff_iter bdi
;
1193 enum dlm_node_state_change sc
;
1197 mlog(0, "something happened such that the "
1198 "master process may need to be restarted!\n");
1200 assert_spin_locked(&mle
->spinlock
);
1202 dlm_bitmap_diff_iter_init(&bdi
, mle
->vote_map
, mle
->node_map
);
1203 node
= dlm_bitmap_diff_iter_next(&bdi
, &sc
);
1205 if (sc
== NODE_UP
) {
1206 /* a node came up. clear any old vote from
1207 * the response map and set it in the vote map
1208 * then restart the mastery. */
1209 mlog(ML_NOTICE
, "node %d up while restarting\n", node
);
1211 /* redo the master request, but only for the new node */
1212 mlog(0, "sending request to new node\n");
1213 clear_bit(node
, mle
->response_map
);
1214 set_bit(node
, mle
->vote_map
);
1216 mlog(ML_ERROR
, "node down! %d\n", node
);
1218 int lowest
= find_next_bit(mle
->maybe_map
,
1221 /* act like it was never there */
1222 clear_bit(node
, mle
->maybe_map
);
1224 if (node
== lowest
) {
1225 mlog(0, "expected master %u died"
1226 " while this node was blocked "
1227 "waiting on it!\n", node
);
1228 lowest
= find_next_bit(mle
->maybe_map
,
1231 if (lowest
< O2NM_MAX_NODES
) {
1232 mlog(0, "%s:%.*s:still "
1233 "blocked. waiting on %u "
1239 /* mle is an MLE_BLOCK, but
1240 * there is now nothing left to
1241 * block on. we need to return
1242 * all the way back out and try
1243 * again with an MLE_MASTER.
1244 * dlm_do_local_recovery_cleanup
1245 * has already run, so the mle
1247 mlog(0, "%s:%.*s: no "
1248 "longer blocking. try to "
1249 "master this here\n",
1252 res
->lockname
.name
);
1253 mle
->type
= DLM_MLE_MASTER
;
1259 /* now blank out everything, as if we had never
1260 * contacted anyone */
1261 memset(mle
->maybe_map
, 0, sizeof(mle
->maybe_map
));
1262 memset(mle
->response_map
, 0, sizeof(mle
->response_map
));
1263 /* reset the vote_map to the current node_map */
1264 memcpy(mle
->vote_map
, mle
->node_map
,
1265 sizeof(mle
->node_map
));
1266 /* put myself into the maybe map */
1267 if (mle
->type
!= DLM_MLE_BLOCK
)
1268 set_bit(dlm
->node_num
, mle
->maybe_map
);
1271 node
= dlm_bitmap_diff_iter_next(&bdi
, &sc
);
1278 * DLM_MASTER_REQUEST_MSG
1280 * returns: 0 on success,
1281 * -errno on a network error
1283 * on error, the caller should assume the target node is "dead"
1287 static int dlm_do_master_request(struct dlm_master_list_entry
*mle
, int to
)
1289 struct dlm_ctxt
*dlm
= mle
->dlm
;
1290 struct dlm_master_request request
;
1291 int ret
, response
=0, resend
;
1293 memset(&request
, 0, sizeof(request
));
1294 request
.node_idx
= dlm
->node_num
;
1296 BUG_ON(mle
->type
== DLM_MLE_MIGRATION
);
1298 if (mle
->type
!= DLM_MLE_MASTER
) {
1299 request
.namelen
= mle
->u
.name
.len
;
1300 memcpy(request
.name
, mle
->u
.name
.name
, request
.namelen
);
1302 request
.namelen
= mle
->u
.res
->lockname
.len
;
1303 memcpy(request
.name
, mle
->u
.res
->lockname
.name
,
1308 ret
= o2net_send_message(DLM_MASTER_REQUEST_MSG
, dlm
->key
, &request
,
1309 sizeof(request
), to
, &response
);
1311 if (ret
== -ESRCH
) {
1312 /* should never happen */
1313 mlog(ML_ERROR
, "TCP stack not ready!\n");
1315 } else if (ret
== -EINVAL
) {
1316 mlog(ML_ERROR
, "bad args passed to o2net!\n");
1318 } else if (ret
== -ENOMEM
) {
1319 mlog(ML_ERROR
, "out of memory while trying to send "
1320 "network message! retrying\n");
1321 /* this is totally crude */
1324 } else if (!dlm_is_host_down(ret
)) {
1325 /* not a network error. bad. */
1327 mlog(ML_ERROR
, "unhandled error!");
1330 /* all other errors should be network errors,
1331 * and likely indicate node death */
1332 mlog(ML_ERROR
, "link to %d went down!\n", to
);
1338 spin_lock(&mle
->spinlock
);
1340 case DLM_MASTER_RESP_YES
:
1341 set_bit(to
, mle
->response_map
);
1342 mlog(0, "node %u is the master, response=YES\n", to
);
1345 case DLM_MASTER_RESP_NO
:
1346 mlog(0, "node %u not master, response=NO\n", to
);
1347 set_bit(to
, mle
->response_map
);
1349 case DLM_MASTER_RESP_MAYBE
:
1350 mlog(0, "node %u not master, response=MAYBE\n", to
);
1351 set_bit(to
, mle
->response_map
);
1352 set_bit(to
, mle
->maybe_map
);
1354 case DLM_MASTER_RESP_ERROR
:
1355 mlog(0, "node %u hit an error, resending\n", to
);
1360 mlog(ML_ERROR
, "bad response! %u\n", response
);
1363 spin_unlock(&mle
->spinlock
);
1365 /* this is also totally crude */
1375 * locks that can be taken here:
1381 * if possible, TRIM THIS DOWN!!!
1383 int dlm_master_request_handler(struct o2net_msg
*msg
, u32 len
, void *data
)
1385 u8 response
= DLM_MASTER_RESP_MAYBE
;
1386 struct dlm_ctxt
*dlm
= data
;
1387 struct dlm_lock_resource
*res
= NULL
;
1388 struct dlm_master_request
*request
= (struct dlm_master_request
*) msg
->buf
;
1389 struct dlm_master_list_entry
*mle
= NULL
, *tmpmle
= NULL
;
1391 unsigned int namelen
, hash
;
1394 int dispatch_assert
= 0;
1397 return DLM_MASTER_RESP_NO
;
1399 if (!dlm_domain_fully_joined(dlm
)) {
1400 response
= DLM_MASTER_RESP_NO
;
1404 name
= request
->name
;
1405 namelen
= request
->namelen
;
1406 hash
= dlm_lockid_hash(name
, namelen
);
1408 if (namelen
> DLM_LOCKID_NAME_MAX
) {
1409 response
= DLM_IVBUFLEN
;
1414 spin_lock(&dlm
->spinlock
);
1415 res
= __dlm_lookup_lockres(dlm
, name
, namelen
, hash
);
1417 spin_unlock(&dlm
->spinlock
);
1419 /* take care of the easy cases up front */
1420 spin_lock(&res
->spinlock
);
1421 if (res
->state
& DLM_LOCK_RES_RECOVERING
) {
1422 spin_unlock(&res
->spinlock
);
1423 mlog(0, "returning DLM_MASTER_RESP_ERROR since res is "
1424 "being recovered\n");
1425 response
= DLM_MASTER_RESP_ERROR
;
1427 kmem_cache_free(dlm_mle_cache
, mle
);
1431 if (res
->owner
== dlm
->node_num
) {
1432 spin_unlock(&res
->spinlock
);
1433 // mlog(0, "this node is the master\n");
1434 response
= DLM_MASTER_RESP_YES
;
1436 kmem_cache_free(dlm_mle_cache
, mle
);
1438 /* this node is the owner.
1439 * there is some extra work that needs to
1440 * happen now. the requesting node has
1441 * caused all nodes up to this one to
1442 * create mles. this node now needs to
1443 * go back and clean those up. */
1444 dispatch_assert
= 1;
1446 } else if (res
->owner
!= DLM_LOCK_RES_OWNER_UNKNOWN
) {
1447 spin_unlock(&res
->spinlock
);
1448 // mlog(0, "node %u is the master\n", res->owner);
1449 response
= DLM_MASTER_RESP_NO
;
1451 kmem_cache_free(dlm_mle_cache
, mle
);
1455 /* ok, there is no owner. either this node is
1456 * being blocked, or it is actively trying to
1457 * master this lock. */
1458 if (!(res
->state
& DLM_LOCK_RES_IN_PROGRESS
)) {
1459 mlog(ML_ERROR
, "lock with no owner should be "
1464 // mlog(0, "lockres is in progress...\n");
1465 spin_lock(&dlm
->master_lock
);
1466 found
= dlm_find_mle(dlm
, &tmpmle
, name
, namelen
);
1468 mlog(ML_ERROR
, "no mle found for this lock!\n");
1472 spin_lock(&tmpmle
->spinlock
);
1473 if (tmpmle
->type
== DLM_MLE_BLOCK
) {
1474 // mlog(0, "this node is waiting for "
1475 // "lockres to be mastered\n");
1476 response
= DLM_MASTER_RESP_NO
;
1477 } else if (tmpmle
->type
== DLM_MLE_MIGRATION
) {
1478 mlog(0, "node %u is master, but trying to migrate to "
1479 "node %u.\n", tmpmle
->master
, tmpmle
->new_master
);
1480 if (tmpmle
->master
== dlm
->node_num
) {
1481 response
= DLM_MASTER_RESP_YES
;
1482 mlog(ML_ERROR
, "no owner on lockres, but this "
1483 "node is trying to migrate it to %u?!\n",
1484 tmpmle
->new_master
);
1487 /* the real master can respond on its own */
1488 response
= DLM_MASTER_RESP_NO
;
1490 } else if (tmpmle
->master
!= DLM_LOCK_RES_OWNER_UNKNOWN
) {
1492 if (tmpmle
->master
== dlm
->node_num
) {
1493 response
= DLM_MASTER_RESP_YES
;
1494 /* this node will be the owner.
1495 * go back and clean the mles on any
1497 dispatch_assert
= 1;
1499 response
= DLM_MASTER_RESP_NO
;
1501 // mlog(0, "this node is attempting to "
1502 // "master lockres\n");
1503 response
= DLM_MASTER_RESP_MAYBE
;
1506 set_bit(request
->node_idx
, tmpmle
->maybe_map
);
1507 spin_unlock(&tmpmle
->spinlock
);
1509 spin_unlock(&dlm
->master_lock
);
1510 spin_unlock(&res
->spinlock
);
1512 /* keep the mle attached to heartbeat events */
1513 dlm_put_mle(tmpmle
);
1515 kmem_cache_free(dlm_mle_cache
, mle
);
1520 * lockres doesn't exist on this node
1521 * if there is an MLE_BLOCK, return NO
1522 * if there is an MLE_MASTER, return MAYBE
1523 * otherwise, add an MLE_BLOCK, return NO
1525 spin_lock(&dlm
->master_lock
);
1526 found
= dlm_find_mle(dlm
, &tmpmle
, name
, namelen
);
1528 /* this lockid has never been seen on this node yet */
1529 // mlog(0, "no mle found\n");
1531 spin_unlock(&dlm
->master_lock
);
1532 spin_unlock(&dlm
->spinlock
);
1534 mle
= (struct dlm_master_list_entry
*)
1535 kmem_cache_alloc(dlm_mle_cache
, GFP_NOFS
);
1537 response
= DLM_MASTER_RESP_ERROR
;
1538 mlog_errno(-ENOMEM
);
1544 // mlog(0, "this is second time thru, already allocated, "
1545 // "add the block.\n");
1546 dlm_init_mle(mle
, DLM_MLE_BLOCK
, dlm
, NULL
, name
, namelen
);
1547 set_bit(request
->node_idx
, mle
->maybe_map
);
1548 list_add(&mle
->list
, &dlm
->master_list
);
1549 response
= DLM_MASTER_RESP_NO
;
1551 // mlog(0, "mle was found\n");
1553 spin_lock(&tmpmle
->spinlock
);
1554 if (tmpmle
->master
== dlm
->node_num
) {
1555 mlog(ML_ERROR
, "no lockres, but an mle with this node as master!\n");
1558 if (tmpmle
->type
== DLM_MLE_BLOCK
)
1559 response
= DLM_MASTER_RESP_NO
;
1560 else if (tmpmle
->type
== DLM_MLE_MIGRATION
) {
1561 mlog(0, "migration mle was found (%u->%u)\n",
1562 tmpmle
->master
, tmpmle
->new_master
);
1563 /* real master can respond on its own */
1564 response
= DLM_MASTER_RESP_NO
;
1566 response
= DLM_MASTER_RESP_MAYBE
;
1568 set_bit(request
->node_idx
, tmpmle
->maybe_map
);
1569 spin_unlock(&tmpmle
->spinlock
);
1571 spin_unlock(&dlm
->master_lock
);
1572 spin_unlock(&dlm
->spinlock
);
1575 /* keep the mle attached to heartbeat events */
1576 dlm_put_mle(tmpmle
);
1580 if (dispatch_assert
) {
1581 if (response
!= DLM_MASTER_RESP_YES
)
1582 mlog(ML_ERROR
, "invalid response %d\n", response
);
1584 mlog(ML_ERROR
, "bad lockres while trying to assert!\n");
1587 mlog(0, "%u is the owner of %.*s, cleaning everyone else\n",
1588 dlm
->node_num
, res
->lockname
.len
, res
->lockname
.name
);
1589 ret
= dlm_dispatch_assert_master(dlm
, res
, 0, request
->node_idx
,
1590 DLM_ASSERT_MASTER_MLE_CLEANUP
);
1592 mlog(ML_ERROR
, "failed to dispatch assert master work\n");
1593 response
= DLM_MASTER_RESP_ERROR
;
1602 * DLM_ASSERT_MASTER_MSG
1607 * NOTE: this can be used for debugging
1608 * can periodically run all locks owned by this node
1609 * and re-assert across the cluster...
1611 static int dlm_do_assert_master(struct dlm_ctxt
*dlm
, const char *lockname
,
1612 unsigned int namelen
, void *nodemap
,
1615 struct dlm_assert_master
assert;
1617 struct dlm_node_iter iter
;
1621 BUG_ON(namelen
> O2NM_MAX_NAME_LEN
);
1625 /* note that if this nodemap is empty, it returns 0 */
1626 dlm_node_iter_init(nodemap
, &iter
);
1627 while ((to
= dlm_node_iter_next(&iter
)) >= 0) {
1629 struct dlm_master_list_entry
*mle
= NULL
;
1631 mlog(0, "sending assert master to %d (%.*s)\n", to
,
1633 memset(&assert, 0, sizeof(assert));
1634 assert.node_idx
= dlm
->node_num
;
1635 assert.namelen
= namelen
;
1636 memcpy(assert.name
, lockname
, namelen
);
1637 assert.flags
= cpu_to_be32(flags
);
1639 tmpret
= o2net_send_message(DLM_ASSERT_MASTER_MSG
, dlm
->key
,
1640 &assert, sizeof(assert), to
, &r
);
1642 mlog(0, "assert_master returned %d!\n", tmpret
);
1643 if (!dlm_is_host_down(tmpret
)) {
1644 mlog(ML_ERROR
, "unhandled error=%d!\n", tmpret
);
1647 /* a node died. finish out the rest of the nodes. */
1648 mlog(0, "link to %d went down!\n", to
);
1649 /* any nonzero status return will do */
1652 /* ok, something horribly messed. kill thyself. */
1653 mlog(ML_ERROR
,"during assert master of %.*s to %u, "
1654 "got %d.\n", namelen
, lockname
, to
, r
);
1655 spin_lock(&dlm
->spinlock
);
1656 spin_lock(&dlm
->master_lock
);
1657 if (dlm_find_mle(dlm
, &mle
, (char *)lockname
,
1659 dlm_print_one_mle(mle
);
1662 spin_unlock(&dlm
->master_lock
);
1663 spin_unlock(&dlm
->spinlock
);
1665 } else if (r
== EAGAIN
) {
1666 mlog(0, "%.*s: node %u create mles on other "
1667 "nodes and requests a re-assert\n",
1668 namelen
, lockname
, to
);
1680 * locks that can be taken here:
1686 * if possible, TRIM THIS DOWN!!!
1688 int dlm_assert_master_handler(struct o2net_msg
*msg
, u32 len
, void *data
)
1690 struct dlm_ctxt
*dlm
= data
;
1691 struct dlm_master_list_entry
*mle
= NULL
;
1692 struct dlm_assert_master
*assert = (struct dlm_assert_master
*)msg
->buf
;
1693 struct dlm_lock_resource
*res
= NULL
;
1695 unsigned int namelen
, hash
;
1697 int master_request
= 0;
1703 name
= assert->name
;
1704 namelen
= assert->namelen
;
1705 hash
= dlm_lockid_hash(name
, namelen
);
1706 flags
= be32_to_cpu(assert->flags
);
1708 if (namelen
> DLM_LOCKID_NAME_MAX
) {
1709 mlog(ML_ERROR
, "Invalid name length!");
1713 spin_lock(&dlm
->spinlock
);
1716 mlog(0, "assert_master with flags: %u\n", flags
);
1719 spin_lock(&dlm
->master_lock
);
1720 if (!dlm_find_mle(dlm
, &mle
, name
, namelen
)) {
1721 /* not an error, could be master just re-asserting */
1722 mlog(0, "just got an assert_master from %u, but no "
1723 "MLE for it! (%.*s)\n", assert->node_idx
,
1726 int bit
= find_next_bit (mle
->maybe_map
, O2NM_MAX_NODES
, 0);
1727 if (bit
>= O2NM_MAX_NODES
) {
1728 /* not necessarily an error, though less likely.
1729 * could be master just re-asserting. */
1730 mlog(0, "no bits set in the maybe_map, but %u "
1731 "is asserting! (%.*s)\n", assert->node_idx
,
1733 } else if (bit
!= assert->node_idx
) {
1734 if (flags
& DLM_ASSERT_MASTER_MLE_CLEANUP
) {
1735 mlog(0, "master %u was found, %u should "
1736 "back off\n", assert->node_idx
, bit
);
1738 /* with the fix for bug 569, a higher node
1739 * number winning the mastery will respond
1740 * YES to mastery requests, but this node
1741 * had no way of knowing. let it pass. */
1742 mlog(0, "%u is the lowest node, "
1743 "%u is asserting. (%.*s) %u must "
1744 "have begun after %u won.\n", bit
,
1745 assert->node_idx
, namelen
, name
, bit
,
1749 if (mle
->type
== DLM_MLE_MIGRATION
) {
1750 if (flags
& DLM_ASSERT_MASTER_MLE_CLEANUP
) {
1751 mlog(0, "%s:%.*s: got cleanup assert"
1752 " from %u for migration\n",
1753 dlm
->name
, namelen
, name
,
1755 } else if (!(flags
& DLM_ASSERT_MASTER_FINISH_MIGRATION
)) {
1756 mlog(0, "%s:%.*s: got unrelated assert"
1757 " from %u for migration, ignoring\n",
1758 dlm
->name
, namelen
, name
,
1761 spin_unlock(&dlm
->master_lock
);
1762 spin_unlock(&dlm
->spinlock
);
1767 spin_unlock(&dlm
->master_lock
);
1769 /* ok everything checks out with the MLE
1770 * now check to see if there is a lockres */
1771 res
= __dlm_lookup_lockres(dlm
, name
, namelen
, hash
);
1773 spin_lock(&res
->spinlock
);
1774 if (res
->state
& DLM_LOCK_RES_RECOVERING
) {
1775 mlog(ML_ERROR
, "%u asserting but %.*s is "
1776 "RECOVERING!\n", assert->node_idx
, namelen
, name
);
1780 if (res
->owner
!= DLM_LOCK_RES_OWNER_UNKNOWN
&&
1781 res
->owner
!= assert->node_idx
) {
1782 mlog(ML_ERROR
, "assert_master from "
1783 "%u, but current owner is "
1785 assert->node_idx
, res
->owner
,
1789 } else if (mle
->type
!= DLM_MLE_MIGRATION
) {
1790 if (res
->owner
!= DLM_LOCK_RES_OWNER_UNKNOWN
) {
1791 /* owner is just re-asserting */
1792 if (res
->owner
== assert->node_idx
) {
1793 mlog(0, "owner %u re-asserting on "
1794 "lock %.*s\n", assert->node_idx
,
1798 mlog(ML_ERROR
, "got assert_master from "
1799 "node %u, but %u is the owner! "
1800 "(%.*s)\n", assert->node_idx
,
1801 res
->owner
, namelen
, name
);
1804 if (!(res
->state
& DLM_LOCK_RES_IN_PROGRESS
)) {
1805 mlog(ML_ERROR
, "got assert from %u, but lock "
1806 "with no owner should be "
1807 "in-progress! (%.*s)\n",
1812 } else /* mle->type == DLM_MLE_MIGRATION */ {
1813 /* should only be getting an assert from new master */
1814 if (assert->node_idx
!= mle
->new_master
) {
1815 mlog(ML_ERROR
, "got assert from %u, but "
1816 "new master is %u, and old master "
1818 assert->node_idx
, mle
->new_master
,
1819 mle
->master
, namelen
, name
);
1825 spin_unlock(&res
->spinlock
);
1827 spin_unlock(&dlm
->spinlock
);
1829 // mlog(0, "woo! got an assert_master from node %u!\n",
1830 // assert->node_idx);
1836 spin_lock(&mle
->spinlock
);
1837 if (mle
->type
== DLM_MLE_BLOCK
|| mle
->type
== DLM_MLE_MIGRATION
)
1840 /* MASTER mle: if any bits set in the response map
1841 * then the calling node needs to re-assert to clear
1842 * up nodes that this node contacted */
1843 while ((nn
= find_next_bit (mle
->response_map
, O2NM_MAX_NODES
,
1844 nn
+1)) < O2NM_MAX_NODES
) {
1845 if (nn
!= dlm
->node_num
&& nn
!= assert->node_idx
)
1849 mle
->master
= assert->node_idx
;
1850 atomic_set(&mle
->woken
, 1);
1852 spin_unlock(&mle
->spinlock
);
1855 spin_lock(&res
->spinlock
);
1856 if (mle
->type
== DLM_MLE_MIGRATION
) {
1857 mlog(0, "finishing off migration of lockres %.*s, "
1859 res
->lockname
.len
, res
->lockname
.name
,
1860 dlm
->node_num
, mle
->new_master
);
1861 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
1862 dlm_change_lockres_owner(dlm
, res
, mle
->new_master
);
1863 BUG_ON(res
->state
& DLM_LOCK_RES_DIRTY
);
1865 dlm_change_lockres_owner(dlm
, res
, mle
->master
);
1867 spin_unlock(&res
->spinlock
);
1870 /* master is known, detach if not already detached.
1871 * ensures that only one assert_master call will happen
1873 spin_lock(&dlm
->spinlock
);
1874 spin_lock(&dlm
->master_lock
);
1876 rr
= atomic_read(&mle
->mle_refs
.refcount
);
1877 if (mle
->inuse
> 0) {
1878 if (extra_ref
&& rr
< 3)
1880 else if (!extra_ref
&& rr
< 2)
1883 if (extra_ref
&& rr
< 2)
1885 else if (!extra_ref
&& rr
< 1)
1889 mlog(ML_ERROR
, "%s:%.*s: got assert master from %u "
1890 "that will mess up this node, refs=%d, extra=%d, "
1891 "inuse=%d\n", dlm
->name
, namelen
, name
,
1892 assert->node_idx
, rr
, extra_ref
, mle
->inuse
);
1893 dlm_print_one_mle(mle
);
1895 list_del_init(&mle
->list
);
1896 __dlm_mle_detach_hb_events(dlm
, mle
);
1899 /* the assert master message now balances the extra
1900 * ref given by the master / migration request message.
1901 * if this is the last put, it will be removed
1905 spin_unlock(&dlm
->master_lock
);
1906 spin_unlock(&dlm
->spinlock
);
1908 if (res
->owner
!= assert->node_idx
) {
1909 mlog(0, "assert_master from %u, but current "
1910 "owner is %u (%.*s), no mle\n", assert->node_idx
,
1911 res
->owner
, namelen
, name
);
1918 dlm_lockres_put(res
);
1920 if (master_request
) {
1921 mlog(0, "need to tell master to reassert\n");
1922 ret
= EAGAIN
; // positive. negative would shoot down the node.
1927 /* kill the caller! */
1928 mlog(ML_ERROR
, "Bad message received from another node. Dumping state "
1929 "and killing the other node now! This node is OK and can continue.\n");
1930 __dlm_print_one_lock_resource(res
);
1931 spin_unlock(&res
->spinlock
);
1932 spin_unlock(&dlm
->spinlock
);
1933 dlm_lockres_put(res
);
1938 int dlm_dispatch_assert_master(struct dlm_ctxt
*dlm
,
1939 struct dlm_lock_resource
*res
,
1940 int ignore_higher
, u8 request_from
, u32 flags
)
1942 struct dlm_work_item
*item
;
1943 item
= kcalloc(1, sizeof(*item
), GFP_NOFS
);
1948 /* queue up work for dlm_assert_master_worker */
1949 dlm_grab(dlm
); /* get an extra ref for the work item */
1950 dlm_init_work_item(dlm
, item
, dlm_assert_master_worker
, NULL
);
1951 item
->u
.am
.lockres
= res
; /* already have a ref */
1952 /* can optionally ignore node numbers higher than this node */
1953 item
->u
.am
.ignore_higher
= ignore_higher
;
1954 item
->u
.am
.request_from
= request_from
;
1955 item
->u
.am
.flags
= flags
;
1958 mlog(0, "IGNORE HIGHER: %.*s\n", res
->lockname
.len
,
1959 res
->lockname
.name
);
1961 spin_lock(&dlm
->work_lock
);
1962 list_add_tail(&item
->list
, &dlm
->work_list
);
1963 spin_unlock(&dlm
->work_lock
);
1965 schedule_work(&dlm
->dispatched_work
);
1969 static void dlm_assert_master_worker(struct dlm_work_item
*item
, void *data
)
1971 struct dlm_ctxt
*dlm
= data
;
1973 struct dlm_lock_resource
*res
;
1974 unsigned long nodemap
[BITS_TO_LONGS(O2NM_MAX_NODES
)];
1981 res
= item
->u
.am
.lockres
;
1982 ignore_higher
= item
->u
.am
.ignore_higher
;
1983 request_from
= item
->u
.am
.request_from
;
1984 flags
= item
->u
.am
.flags
;
1986 spin_lock(&dlm
->spinlock
);
1987 memcpy(nodemap
, dlm
->domain_map
, sizeof(nodemap
));
1988 spin_unlock(&dlm
->spinlock
);
1990 clear_bit(dlm
->node_num
, nodemap
);
1991 if (ignore_higher
) {
1992 /* if is this just to clear up mles for nodes below
1993 * this node, do not send the message to the original
1994 * caller or any node number higher than this */
1995 clear_bit(request_from
, nodemap
);
1996 bit
= dlm
->node_num
;
1998 bit
= find_next_bit(nodemap
, O2NM_MAX_NODES
,
2000 if (bit
>= O2NM_MAX_NODES
)
2002 clear_bit(bit
, nodemap
);
2007 * If we're migrating this lock to someone else, we are no
2008 * longer allowed to assert out own mastery. OTOH, we need to
2009 * prevent migration from starting while we're still asserting
2010 * our dominance. The reserved ast delays migration.
2012 spin_lock(&res
->spinlock
);
2013 if (res
->state
& DLM_LOCK_RES_MIGRATING
) {
2014 mlog(0, "Someone asked us to assert mastery, but we're "
2015 "in the middle of migration. Skipping assert, "
2016 "the new master will handle that.\n");
2017 spin_unlock(&res
->spinlock
);
2020 __dlm_lockres_reserve_ast(res
);
2021 spin_unlock(&res
->spinlock
);
2023 /* this call now finishes out the nodemap
2024 * even if one or more nodes die */
2025 mlog(0, "worker about to master %.*s here, this=%u\n",
2026 res
->lockname
.len
, res
->lockname
.name
, dlm
->node_num
);
2027 ret
= dlm_do_assert_master(dlm
, res
->lockname
.name
,
2031 /* no need to restart, we are done */
2032 if (!dlm_is_host_down(ret
))
2036 /* Ok, we've asserted ourselves. Let's let migration start. */
2037 dlm_lockres_release_ast(dlm
, res
);
2040 dlm_lockres_put(res
);
2042 mlog(0, "finished with dlm_assert_master_worker\n");
2045 /* SPECIAL CASE for the $RECOVERY lock used by the recovery thread.
2046 * We cannot wait for node recovery to complete to begin mastering this
2047 * lockres because this lockres is used to kick off recovery! ;-)
2048 * So, do a pre-check on all living nodes to see if any of those nodes
2049 * think that $RECOVERY is currently mastered by a dead node. If so,
2050 * we wait a short time to allow that node to get notified by its own
2051 * heartbeat stack, then check again. All $RECOVERY lock resources
2052 * mastered by dead nodes are purged when the hearbeat callback is
2053 * fired, so we can know for sure that it is safe to continue once
2054 * the node returns a live node or no node. */
2055 static int dlm_pre_master_reco_lockres(struct dlm_ctxt
*dlm
,
2056 struct dlm_lock_resource
*res
)
2058 struct dlm_node_iter iter
;
2061 u8 master
= DLM_LOCK_RES_OWNER_UNKNOWN
;
2063 spin_lock(&dlm
->spinlock
);
2064 dlm_node_iter_init(dlm
->domain_map
, &iter
);
2065 spin_unlock(&dlm
->spinlock
);
2067 while ((nodenum
= dlm_node_iter_next(&iter
)) >= 0) {
2068 /* do not send to self */
2069 if (nodenum
== dlm
->node_num
)
2071 ret
= dlm_do_master_requery(dlm
, res
, nodenum
, &master
);
2074 if (!dlm_is_host_down(ret
))
2076 /* host is down, so answer for that node would be
2077 * DLM_LOCK_RES_OWNER_UNKNOWN. continue. */
2081 if (master
!= DLM_LOCK_RES_OWNER_UNKNOWN
) {
2082 /* check to see if this master is in the recovery map */
2083 spin_lock(&dlm
->spinlock
);
2084 if (test_bit(master
, dlm
->recovery_map
)) {
2085 mlog(ML_NOTICE
, "%s: node %u has not seen "
2086 "node %u go down yet, and thinks the "
2087 "dead node is mastering the recovery "
2088 "lock. must wait.\n", dlm
->name
,
2092 spin_unlock(&dlm
->spinlock
);
2093 mlog(0, "%s: reco lock master is %u\n", dlm
->name
,
2103 * DLM_MIGRATE_LOCKRES
2107 int dlm_migrate_lockres(struct dlm_ctxt
*dlm
, struct dlm_lock_resource
*res
,
2110 struct dlm_master_list_entry
*mle
= NULL
;
2111 struct dlm_master_list_entry
*oldmle
= NULL
;
2112 struct dlm_migratable_lockres
*mres
= NULL
;
2115 unsigned int namelen
;
2117 struct list_head
*queue
, *iter
;
2119 struct dlm_lock
*lock
;
2125 name
= res
->lockname
.name
;
2126 namelen
= res
->lockname
.len
;
2128 mlog(0, "migrating %.*s to %u\n", namelen
, name
, target
);
2131 * ensure this lockres is a proper candidate for migration
2133 spin_lock(&res
->spinlock
);
2134 if (res
->owner
== DLM_LOCK_RES_OWNER_UNKNOWN
) {
2135 mlog(0, "cannot migrate lockres with unknown owner!\n");
2136 spin_unlock(&res
->spinlock
);
2139 if (res
->owner
!= dlm
->node_num
) {
2140 mlog(0, "cannot migrate lockres this node doesn't own!\n");
2141 spin_unlock(&res
->spinlock
);
2144 mlog(0, "checking queues...\n");
2145 queue
= &res
->granted
;
2146 for (i
=0; i
<3; i
++) {
2147 list_for_each(iter
, queue
) {
2148 lock
= list_entry (iter
, struct dlm_lock
, list
);
2150 if (lock
->ml
.node
== dlm
->node_num
) {
2151 mlog(0, "found a lock owned by this node "
2152 "still on the %s queue! will not "
2153 "migrate this lockres\n",
2155 (i
==1 ? "converting" : "blocked"));
2156 spin_unlock(&res
->spinlock
);
2163 mlog(0, "all locks on this lockres are nonlocal. continuing\n");
2164 spin_unlock(&res
->spinlock
);
2168 mlog(0, "no locks were found on this lockres! done!\n");
2174 * preallocate up front
2175 * if this fails, abort
2179 mres
= (struct dlm_migratable_lockres
*) __get_free_page(GFP_NOFS
);
2185 mle
= (struct dlm_master_list_entry
*) kmem_cache_alloc(dlm_mle_cache
,
2194 * find a node to migrate the lockres to
2197 mlog(0, "picking a migration node\n");
2198 spin_lock(&dlm
->spinlock
);
2199 /* pick a new node */
2200 if (!test_bit(target
, dlm
->domain_map
) ||
2201 target
>= O2NM_MAX_NODES
) {
2202 target
= dlm_pick_migration_target(dlm
, res
);
2204 mlog(0, "node %u chosen for migration\n", target
);
2206 if (target
>= O2NM_MAX_NODES
||
2207 !test_bit(target
, dlm
->domain_map
)) {
2208 /* target chosen is not alive */
2213 spin_unlock(&dlm
->spinlock
);
2217 mlog(0, "continuing with target = %u\n", target
);
2220 * clear any existing master requests and
2221 * add the migration mle to the list
2223 spin_lock(&dlm
->master_lock
);
2224 ret
= dlm_add_migration_mle(dlm
, res
, mle
, &oldmle
, name
,
2225 namelen
, target
, dlm
->node_num
);
2226 spin_unlock(&dlm
->master_lock
);
2227 spin_unlock(&dlm
->spinlock
);
2229 if (ret
== -EEXIST
) {
2230 mlog(0, "another process is already migrating it\n");
2236 * set the MIGRATING flag and flush asts
2237 * if we fail after this we need to re-dirty the lockres
2239 if (dlm_mark_lockres_migrating(dlm
, res
, target
) < 0) {
2240 mlog(ML_ERROR
, "tried to migrate %.*s to %u, but "
2241 "the target went down.\n", res
->lockname
.len
,
2242 res
->lockname
.name
, target
);
2243 spin_lock(&res
->spinlock
);
2244 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
2245 spin_unlock(&res
->spinlock
);
2251 /* master is known, detach if not already detached */
2252 dlm_mle_detach_hb_events(dlm
, oldmle
);
2253 dlm_put_mle(oldmle
);
2258 dlm_mle_detach_hb_events(dlm
, mle
);
2261 kmem_cache_free(dlm_mle_cache
, mle
);
2267 * at this point, we have a migration target, an mle
2268 * in the master list, and the MIGRATING flag set on
2273 /* get an extra reference on the mle.
2274 * otherwise the assert_master from the new
2275 * master will destroy this.
2276 * also, make sure that all callers of dlm_get_mle
2277 * take both dlm->spinlock and dlm->master_lock */
2278 spin_lock(&dlm
->spinlock
);
2279 spin_lock(&dlm
->master_lock
);
2280 dlm_get_mle_inuse(mle
);
2281 spin_unlock(&dlm
->master_lock
);
2282 spin_unlock(&dlm
->spinlock
);
2284 /* notify new node and send all lock state */
2285 /* call send_one_lockres with migration flag.
2286 * this serves as notice to the target node that a
2287 * migration is starting. */
2288 ret
= dlm_send_one_lockres(dlm
, res
, mres
, target
,
2289 DLM_MRES_MIGRATION
);
2292 mlog(0, "migration to node %u failed with %d\n",
2294 /* migration failed, detach and clean up mle */
2295 dlm_mle_detach_hb_events(dlm
, mle
);
2297 dlm_put_mle_inuse(mle
);
2298 spin_lock(&res
->spinlock
);
2299 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
2300 spin_unlock(&res
->spinlock
);
2304 /* at this point, the target sends a message to all nodes,
2305 * (using dlm_do_migrate_request). this node is skipped since
2306 * we had to put an mle in the list to begin the process. this
2307 * node now waits for target to do an assert master. this node
2308 * will be the last one notified, ensuring that the migration
2309 * is complete everywhere. if the target dies while this is
2310 * going on, some nodes could potentially see the target as the
2311 * master, so it is important that my recovery finds the migration
2312 * mle and sets the master to UNKNONWN. */
2315 /* wait for new node to assert master */
2317 ret
= wait_event_interruptible_timeout(mle
->wq
,
2318 (atomic_read(&mle
->woken
) == 1),
2319 msecs_to_jiffies(5000));
2322 if (atomic_read(&mle
->woken
) == 1 ||
2323 res
->owner
== target
)
2326 mlog(0, "timed out during migration\n");
2327 /* avoid hang during shutdown when migrating lockres
2328 * to a node which also goes down */
2329 if (dlm_is_node_dead(dlm
, target
)) {
2330 mlog(0, "%s:%.*s: expected migration "
2331 "target %u is no longer up, restarting\n",
2332 dlm
->name
, res
->lockname
.len
,
2333 res
->lockname
.name
, target
);
2337 if (ret
== -ERESTARTSYS
) {
2338 /* migration failed, detach and clean up mle */
2339 dlm_mle_detach_hb_events(dlm
, mle
);
2341 dlm_put_mle_inuse(mle
);
2342 spin_lock(&res
->spinlock
);
2343 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
2344 spin_unlock(&res
->spinlock
);
2347 /* TODO: if node died: stop, clean up, return error */
2350 /* all done, set the owner, clear the flag */
2351 spin_lock(&res
->spinlock
);
2352 dlm_set_lockres_owner(dlm
, res
, target
);
2353 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
2354 dlm_remove_nonlocal_locks(dlm
, res
);
2355 spin_unlock(&res
->spinlock
);
2358 /* master is known, detach if not already detached */
2359 dlm_mle_detach_hb_events(dlm
, mle
);
2360 dlm_put_mle_inuse(mle
);
2363 dlm_lockres_calc_usage(dlm
, res
);
2366 /* re-dirty the lockres if we failed */
2368 dlm_kick_thread(dlm
, res
);
2372 free_page((unsigned long)mres
);
2376 mlog(0, "returning %d\n", ret
);
2379 EXPORT_SYMBOL_GPL(dlm_migrate_lockres
);
2381 int dlm_lock_basts_flushed(struct dlm_ctxt
*dlm
, struct dlm_lock
*lock
)
2384 spin_lock(&dlm
->ast_lock
);
2385 spin_lock(&lock
->spinlock
);
2386 ret
= (list_empty(&lock
->bast_list
) && !lock
->bast_pending
);
2387 spin_unlock(&lock
->spinlock
);
2388 spin_unlock(&dlm
->ast_lock
);
2392 static int dlm_migration_can_proceed(struct dlm_ctxt
*dlm
,
2393 struct dlm_lock_resource
*res
,
2397 spin_lock(&res
->spinlock
);
2398 can_proceed
= !!(res
->state
& DLM_LOCK_RES_MIGRATING
);
2399 spin_unlock(&res
->spinlock
);
2401 /* target has died, so make the caller break out of the
2402 * wait_event, but caller must recheck the domain_map */
2403 spin_lock(&dlm
->spinlock
);
2404 if (!test_bit(mig_target
, dlm
->domain_map
))
2406 spin_unlock(&dlm
->spinlock
);
2410 int dlm_lockres_is_dirty(struct dlm_ctxt
*dlm
, struct dlm_lock_resource
*res
)
2413 spin_lock(&res
->spinlock
);
2414 ret
= !!(res
->state
& DLM_LOCK_RES_DIRTY
);
2415 spin_unlock(&res
->spinlock
);
2420 static int dlm_mark_lockres_migrating(struct dlm_ctxt
*dlm
,
2421 struct dlm_lock_resource
*res
,
2426 mlog(0, "dlm_mark_lockres_migrating: %.*s, from %u to %u\n",
2427 res
->lockname
.len
, res
->lockname
.name
, dlm
->node_num
,
2429 /* need to set MIGRATING flag on lockres. this is done by
2430 * ensuring that all asts have been flushed for this lockres. */
2431 spin_lock(&res
->spinlock
);
2432 BUG_ON(res
->migration_pending
);
2433 res
->migration_pending
= 1;
2434 /* strategy is to reserve an extra ast then release
2435 * it below, letting the release do all of the work */
2436 __dlm_lockres_reserve_ast(res
);
2437 spin_unlock(&res
->spinlock
);
2439 /* now flush all the pending asts.. hang out for a bit */
2440 dlm_kick_thread(dlm
, res
);
2441 wait_event(dlm
->ast_wq
, !dlm_lockres_is_dirty(dlm
, res
));
2442 dlm_lockres_release_ast(dlm
, res
);
2444 mlog(0, "about to wait on migration_wq, dirty=%s\n",
2445 res
->state
& DLM_LOCK_RES_DIRTY
? "yes" : "no");
2446 /* if the extra ref we just put was the final one, this
2447 * will pass thru immediately. otherwise, we need to wait
2448 * for the last ast to finish. */
2450 ret
= wait_event_interruptible_timeout(dlm
->migration_wq
,
2451 dlm_migration_can_proceed(dlm
, res
, target
),
2452 msecs_to_jiffies(1000));
2454 mlog(0, "woken again: migrating? %s, dead? %s\n",
2455 res
->state
& DLM_LOCK_RES_MIGRATING
? "yes":"no",
2456 test_bit(target
, dlm
->domain_map
) ? "no":"yes");
2458 mlog(0, "all is well: migrating? %s, dead? %s\n",
2459 res
->state
& DLM_LOCK_RES_MIGRATING
? "yes":"no",
2460 test_bit(target
, dlm
->domain_map
) ? "no":"yes");
2462 if (!dlm_migration_can_proceed(dlm
, res
, target
)) {
2463 mlog(0, "trying again...\n");
2467 /* did the target go down or die? */
2468 spin_lock(&dlm
->spinlock
);
2469 if (!test_bit(target
, dlm
->domain_map
)) {
2470 mlog(ML_ERROR
, "aha. migration target %u just went down\n",
2474 spin_unlock(&dlm
->spinlock
);
2479 * o the DLM_LOCK_RES_MIGRATING flag is set
2480 * o there are no pending asts on this lockres
2481 * o all processes trying to reserve an ast on this
2482 * lockres must wait for the MIGRATING flag to clear
2487 /* last step in the migration process.
2488 * original master calls this to free all of the dlm_lock
2489 * structures that used to be for other nodes. */
2490 static void dlm_remove_nonlocal_locks(struct dlm_ctxt
*dlm
,
2491 struct dlm_lock_resource
*res
)
2493 struct list_head
*iter
, *iter2
;
2494 struct list_head
*queue
= &res
->granted
;
2496 struct dlm_lock
*lock
;
2498 assert_spin_locked(&res
->spinlock
);
2500 BUG_ON(res
->owner
== dlm
->node_num
);
2502 for (i
=0; i
<3; i
++) {
2503 list_for_each_safe(iter
, iter2
, queue
) {
2504 lock
= list_entry (iter
, struct dlm_lock
, list
);
2505 if (lock
->ml
.node
!= dlm
->node_num
) {
2506 mlog(0, "putting lock for node %u\n",
2508 /* be extra careful */
2509 BUG_ON(!list_empty(&lock
->ast_list
));
2510 BUG_ON(!list_empty(&lock
->bast_list
));
2511 BUG_ON(lock
->ast_pending
);
2512 BUG_ON(lock
->bast_pending
);
2513 list_del_init(&lock
->list
);
2521 /* for now this is not too intelligent. we will
2522 * need stats to make this do the right thing.
2523 * this just finds the first lock on one of the
2524 * queues and uses that node as the target. */
2525 static u8
dlm_pick_migration_target(struct dlm_ctxt
*dlm
,
2526 struct dlm_lock_resource
*res
)
2529 struct list_head
*queue
= &res
->granted
;
2530 struct list_head
*iter
;
2531 struct dlm_lock
*lock
;
2534 assert_spin_locked(&dlm
->spinlock
);
2536 spin_lock(&res
->spinlock
);
2537 for (i
=0; i
<3; i
++) {
2538 list_for_each(iter
, queue
) {
2539 /* up to the caller to make sure this node
2541 lock
= list_entry (iter
, struct dlm_lock
, list
);
2542 if (lock
->ml
.node
!= dlm
->node_num
) {
2543 spin_unlock(&res
->spinlock
);
2544 return lock
->ml
.node
;
2549 spin_unlock(&res
->spinlock
);
2550 mlog(0, "have not found a suitable target yet! checking domain map\n");
2552 /* ok now we're getting desperate. pick anyone alive. */
2555 nodenum
= find_next_bit(dlm
->domain_map
,
2556 O2NM_MAX_NODES
, nodenum
+1);
2557 mlog(0, "found %d in domain map\n", nodenum
);
2558 if (nodenum
>= O2NM_MAX_NODES
)
2560 if (nodenum
!= dlm
->node_num
) {
2561 mlog(0, "picking %d\n", nodenum
);
2566 mlog(0, "giving up. no master to migrate to\n");
2567 return DLM_LOCK_RES_OWNER_UNKNOWN
;
2572 /* this is called by the new master once all lockres
2573 * data has been received */
2574 static int dlm_do_migrate_request(struct dlm_ctxt
*dlm
,
2575 struct dlm_lock_resource
*res
,
2576 u8 master
, u8 new_master
,
2577 struct dlm_node_iter
*iter
)
2579 struct dlm_migrate_request migrate
;
2580 int ret
, status
= 0;
2583 memset(&migrate
, 0, sizeof(migrate
));
2584 migrate
.namelen
= res
->lockname
.len
;
2585 memcpy(migrate
.name
, res
->lockname
.name
, migrate
.namelen
);
2586 migrate
.new_master
= new_master
;
2587 migrate
.master
= master
;
2591 /* send message to all nodes, except the master and myself */
2592 while ((nodenum
= dlm_node_iter_next(iter
)) >= 0) {
2593 if (nodenum
== master
||
2594 nodenum
== new_master
)
2597 ret
= o2net_send_message(DLM_MIGRATE_REQUEST_MSG
, dlm
->key
,
2598 &migrate
, sizeof(migrate
), nodenum
,
2602 else if (status
< 0) {
2603 mlog(0, "migrate request (node %u) returned %d!\n",
2612 mlog(0, "returning ret=%d\n", ret
);
2617 /* if there is an existing mle for this lockres, we now know who the master is.
2618 * (the one who sent us *this* message) we can clear it up right away.
2619 * since the process that put the mle on the list still has a reference to it,
2620 * we can unhash it now, set the master and wake the process. as a result,
2621 * we will have no mle in the list to start with. now we can add an mle for
2622 * the migration and this should be the only one found for those scanning the
2624 int dlm_migrate_request_handler(struct o2net_msg
*msg
, u32 len
, void *data
)
2626 struct dlm_ctxt
*dlm
= data
;
2627 struct dlm_lock_resource
*res
= NULL
;
2628 struct dlm_migrate_request
*migrate
= (struct dlm_migrate_request
*) msg
->buf
;
2629 struct dlm_master_list_entry
*mle
= NULL
, *oldmle
= NULL
;
2631 unsigned int namelen
, hash
;
2637 name
= migrate
->name
;
2638 namelen
= migrate
->namelen
;
2639 hash
= dlm_lockid_hash(name
, namelen
);
2641 /* preallocate.. if this fails, abort */
2642 mle
= (struct dlm_master_list_entry
*) kmem_cache_alloc(dlm_mle_cache
,
2650 /* check for pre-existing lock */
2651 spin_lock(&dlm
->spinlock
);
2652 res
= __dlm_lookup_lockres(dlm
, name
, namelen
, hash
);
2653 spin_lock(&dlm
->master_lock
);
2656 spin_lock(&res
->spinlock
);
2657 if (res
->state
& DLM_LOCK_RES_RECOVERING
) {
2658 /* if all is working ok, this can only mean that we got
2659 * a migrate request from a node that we now see as
2660 * dead. what can we do here? drop it to the floor? */
2661 spin_unlock(&res
->spinlock
);
2662 mlog(ML_ERROR
, "Got a migrate request, but the "
2663 "lockres is marked as recovering!");
2664 kmem_cache_free(dlm_mle_cache
, mle
);
2665 ret
= -EINVAL
; /* need a better solution */
2668 res
->state
|= DLM_LOCK_RES_MIGRATING
;
2669 spin_unlock(&res
->spinlock
);
2672 /* ignore status. only nonzero status would BUG. */
2673 ret
= dlm_add_migration_mle(dlm
, res
, mle
, &oldmle
,
2675 migrate
->new_master
,
2679 spin_unlock(&dlm
->master_lock
);
2680 spin_unlock(&dlm
->spinlock
);
2683 /* master is known, detach if not already detached */
2684 dlm_mle_detach_hb_events(dlm
, oldmle
);
2685 dlm_put_mle(oldmle
);
2689 dlm_lockres_put(res
);
2695 /* must be holding dlm->spinlock and dlm->master_lock
2696 * when adding a migration mle, we can clear any other mles
2697 * in the master list because we know with certainty that
2698 * the master is "master". so we remove any old mle from
2699 * the list after setting it's master field, and then add
2700 * the new migration mle. this way we can hold with the rule
2701 * of having only one mle for a given lock name at all times. */
2702 static int dlm_add_migration_mle(struct dlm_ctxt
*dlm
,
2703 struct dlm_lock_resource
*res
,
2704 struct dlm_master_list_entry
*mle
,
2705 struct dlm_master_list_entry
**oldmle
,
2706 const char *name
, unsigned int namelen
,
2707 u8 new_master
, u8 master
)
2716 assert_spin_locked(&dlm
->spinlock
);
2717 assert_spin_locked(&dlm
->master_lock
);
2719 /* caller is responsible for any ref taken here on oldmle */
2720 found
= dlm_find_mle(dlm
, oldmle
, (char *)name
, namelen
);
2722 struct dlm_master_list_entry
*tmp
= *oldmle
;
2723 spin_lock(&tmp
->spinlock
);
2724 if (tmp
->type
== DLM_MLE_MIGRATION
) {
2725 if (master
== dlm
->node_num
) {
2726 /* ah another process raced me to it */
2727 mlog(0, "tried to migrate %.*s, but some "
2728 "process beat me to it\n",
2732 /* bad. 2 NODES are trying to migrate! */
2733 mlog(ML_ERROR
, "migration error mle: "
2734 "master=%u new_master=%u // request: "
2735 "master=%u new_master=%u // "
2737 tmp
->master
, tmp
->new_master
,
2743 /* this is essentially what assert_master does */
2744 tmp
->master
= master
;
2745 atomic_set(&tmp
->woken
, 1);
2747 /* remove it from the list so that only one
2748 * mle will be found */
2749 list_del_init(&tmp
->list
);
2750 __dlm_mle_detach_hb_events(dlm
, mle
);
2752 spin_unlock(&tmp
->spinlock
);
2755 /* now add a migration mle to the tail of the list */
2756 dlm_init_mle(mle
, DLM_MLE_MIGRATION
, dlm
, res
, name
, namelen
);
2757 mle
->new_master
= new_master
;
2758 mle
->master
= master
;
2759 /* do this for consistency with other mle types */
2760 set_bit(new_master
, mle
->maybe_map
);
2761 list_add(&mle
->list
, &dlm
->master_list
);
2767 void dlm_clean_master_list(struct dlm_ctxt
*dlm
, u8 dead_node
)
2769 struct list_head
*iter
, *iter2
;
2770 struct dlm_master_list_entry
*mle
;
2771 struct dlm_lock_resource
*res
;
2774 mlog_entry("dlm=%s, dead node=%u\n", dlm
->name
, dead_node
);
2776 assert_spin_locked(&dlm
->spinlock
);
2778 /* clean the master list */
2779 spin_lock(&dlm
->master_lock
);
2780 list_for_each_safe(iter
, iter2
, &dlm
->master_list
) {
2781 mle
= list_entry(iter
, struct dlm_master_list_entry
, list
);
2783 BUG_ON(mle
->type
!= DLM_MLE_BLOCK
&&
2784 mle
->type
!= DLM_MLE_MASTER
&&
2785 mle
->type
!= DLM_MLE_MIGRATION
);
2787 /* MASTER mles are initiated locally. the waiting
2788 * process will notice the node map change
2789 * shortly. let that happen as normal. */
2790 if (mle
->type
== DLM_MLE_MASTER
)
2794 /* BLOCK mles are initiated by other nodes.
2795 * need to clean up if the dead node would have
2796 * been the master. */
2797 if (mle
->type
== DLM_MLE_BLOCK
) {
2800 spin_lock(&mle
->spinlock
);
2801 bit
= find_next_bit(mle
->maybe_map
, O2NM_MAX_NODES
, 0);
2802 if (bit
!= dead_node
) {
2803 mlog(0, "mle found, but dead node %u would "
2804 "not have been master\n", dead_node
);
2805 spin_unlock(&mle
->spinlock
);
2807 /* must drop the refcount by one since the
2808 * assert_master will never arrive. this
2809 * may result in the mle being unlinked and
2810 * freed, but there may still be a process
2811 * waiting in the dlmlock path which is fine. */
2812 mlog(0, "node %u was expected master\n",
2814 atomic_set(&mle
->woken
, 1);
2815 spin_unlock(&mle
->spinlock
);
2817 /* do not need events any longer, so detach
2819 __dlm_mle_detach_hb_events(dlm
, mle
);
2825 /* everything else is a MIGRATION mle */
2827 /* the rule for MIGRATION mles is that the master
2828 * becomes UNKNOWN if *either* the original or
2829 * the new master dies. all UNKNOWN lockreses
2830 * are sent to whichever node becomes the recovery
2831 * master. the new master is responsible for
2832 * determining if there is still a master for
2833 * this lockres, or if he needs to take over
2834 * mastery. either way, this node should expect
2835 * another message to resolve this. */
2836 if (mle
->master
!= dead_node
&&
2837 mle
->new_master
!= dead_node
)
2840 /* if we have reached this point, this mle needs to
2841 * be removed from the list and freed. */
2843 /* remove from the list early. NOTE: unlinking
2844 * list_head while in list_for_each_safe */
2845 __dlm_mle_detach_hb_events(dlm
, mle
);
2846 spin_lock(&mle
->spinlock
);
2847 list_del_init(&mle
->list
);
2848 atomic_set(&mle
->woken
, 1);
2849 spin_unlock(&mle
->spinlock
);
2852 mlog(0, "%s: node %u died during migration from "
2853 "%u to %u!\n", dlm
->name
, dead_node
,
2854 mle
->master
, mle
->new_master
);
2855 /* if there is a lockres associated with this
2856 * mle, find it and set its owner to UNKNOWN */
2857 hash
= dlm_lockid_hash(mle
->u
.name
.name
, mle
->u
.name
.len
);
2858 res
= __dlm_lookup_lockres(dlm
, mle
->u
.name
.name
,
2859 mle
->u
.name
.len
, hash
);
2861 /* unfortunately if we hit this rare case, our
2862 * lock ordering is messed. we need to drop
2863 * the master lock so that we can take the
2864 * lockres lock, meaning that we will have to
2865 * restart from the head of list. */
2866 spin_unlock(&dlm
->master_lock
);
2868 /* move lockres onto recovery list */
2869 spin_lock(&res
->spinlock
);
2870 dlm_set_lockres_owner(dlm
, res
,
2871 DLM_LOCK_RES_OWNER_UNKNOWN
);
2872 dlm_move_lockres_to_recovery_list(dlm
, res
);
2873 spin_unlock(&res
->spinlock
);
2874 dlm_lockres_put(res
);
2876 /* about to get rid of mle, detach from heartbeat */
2877 __dlm_mle_detach_hb_events(dlm
, mle
);
2880 spin_lock(&dlm
->master_lock
);
2882 spin_unlock(&dlm
->master_lock
);
2888 /* this may be the last reference */
2891 spin_unlock(&dlm
->master_lock
);
2895 int dlm_finish_migration(struct dlm_ctxt
*dlm
, struct dlm_lock_resource
*res
,
2898 struct dlm_node_iter iter
;
2901 spin_lock(&dlm
->spinlock
);
2902 dlm_node_iter_init(dlm
->domain_map
, &iter
);
2903 clear_bit(old_master
, iter
.node_map
);
2904 clear_bit(dlm
->node_num
, iter
.node_map
);
2905 spin_unlock(&dlm
->spinlock
);
2907 mlog(0, "now time to do a migrate request to other nodes\n");
2908 ret
= dlm_do_migrate_request(dlm
, res
, old_master
,
2909 dlm
->node_num
, &iter
);
2915 mlog(0, "doing assert master of %.*s to all except the original node\n",
2916 res
->lockname
.len
, res
->lockname
.name
);
2917 /* this call now finishes out the nodemap
2918 * even if one or more nodes die */
2919 ret
= dlm_do_assert_master(dlm
, res
->lockname
.name
,
2920 res
->lockname
.len
, iter
.node_map
,
2921 DLM_ASSERT_MASTER_FINISH_MIGRATION
);
2923 /* no longer need to retry. all living nodes contacted. */
2928 memset(iter
.node_map
, 0, sizeof(iter
.node_map
));
2929 set_bit(old_master
, iter
.node_map
);
2930 mlog(0, "doing assert master of %.*s back to %u\n",
2931 res
->lockname
.len
, res
->lockname
.name
, old_master
);
2932 ret
= dlm_do_assert_master(dlm
, res
->lockname
.name
,
2933 res
->lockname
.len
, iter
.node_map
,
2934 DLM_ASSERT_MASTER_FINISH_MIGRATION
);
2936 mlog(0, "assert master to original master failed "
2938 /* the only nonzero status here would be because of
2939 * a dead original node. we're done. */
2943 /* all done, set the owner, clear the flag */
2944 spin_lock(&res
->spinlock
);
2945 dlm_set_lockres_owner(dlm
, res
, dlm
->node_num
);
2946 res
->state
&= ~DLM_LOCK_RES_MIGRATING
;
2947 spin_unlock(&res
->spinlock
);
2948 /* re-dirty it on the new master */
2949 dlm_kick_thread(dlm
, res
);
2956 * LOCKRES AST REFCOUNT
2957 * this is integral to migration
2960 /* for future intent to call an ast, reserve one ahead of time.
2961 * this should be called only after waiting on the lockres
2962 * with dlm_wait_on_lockres, and while still holding the
2963 * spinlock after the call. */
2964 void __dlm_lockres_reserve_ast(struct dlm_lock_resource
*res
)
2966 assert_spin_locked(&res
->spinlock
);
2967 if (res
->state
& DLM_LOCK_RES_MIGRATING
) {
2968 __dlm_print_one_lock_resource(res
);
2970 BUG_ON(res
->state
& DLM_LOCK_RES_MIGRATING
);
2972 atomic_inc(&res
->asts_reserved
);
2976 * used to drop the reserved ast, either because it went unused,
2977 * or because the ast/bast was actually called.
2979 * also, if there is a pending migration on this lockres,
2980 * and this was the last pending ast on the lockres,
2981 * atomically set the MIGRATING flag before we drop the lock.
2982 * this is how we ensure that migration can proceed with no
2983 * asts in progress. note that it is ok if the state of the
2984 * queues is such that a lock should be granted in the future
2985 * or that a bast should be fired, because the new master will
2986 * shuffle the lists on this lockres as soon as it is migrated.
2988 void dlm_lockres_release_ast(struct dlm_ctxt
*dlm
,
2989 struct dlm_lock_resource
*res
)
2991 if (!atomic_dec_and_lock(&res
->asts_reserved
, &res
->spinlock
))
2994 if (!res
->migration_pending
) {
2995 spin_unlock(&res
->spinlock
);
2999 BUG_ON(res
->state
& DLM_LOCK_RES_MIGRATING
);
3000 res
->migration_pending
= 0;
3001 res
->state
|= DLM_LOCK_RES_MIGRATING
;
3002 spin_unlock(&res
->spinlock
);
3004 wake_up(&dlm
->migration_wq
);