ARM: rockchip: fix broken build
[linux/fpc-iii.git] / fs / ocfs2 / dlm / dlmmaster.c
blobfdf4b41d0609a00e591afeed69ea7cc2ab9d5254
1 /* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
4 * dlmmod.c
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>
29 #include <linux/fs.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"
47 #include "dlmapi.h"
48 #include "dlmcommon.h"
49 #include "dlmdomain.h"
50 #include "dlmdebug.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,
58 int idx);
59 static void dlm_mle_node_up(struct dlm_ctxt *dlm,
60 struct dlm_master_list_entry *mle,
61 struct o2nm_node *node,
62 int idx);
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,
72 const char *name,
73 unsigned int namelen)
75 if (dlm != mle->dlm)
76 return 0;
78 if (namelen != mle->mnamelen ||
79 memcmp(name, mle->mname, namelen) != 0)
80 return 0;
82 return 1;
85 static struct kmem_cache *dlm_lockres_cache;
86 static struct kmem_cache *dlm_lockname_cache;
87 static struct kmem_cache *dlm_mle_cache;
89 static void dlm_mle_release(struct kref *kref);
90 static void dlm_init_mle(struct dlm_master_list_entry *mle,
91 enum dlm_mle_type type,
92 struct dlm_ctxt *dlm,
93 struct dlm_lock_resource *res,
94 const char *name,
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,
109 int *blocked);
110 static int dlm_restart_lock_mastery(struct dlm_ctxt *dlm,
111 struct dlm_lock_resource *res,
112 struct dlm_master_list_entry *mle,
113 int blocked);
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,
127 u8 target);
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)
134 switch (errno) {
135 case -EBADF:
136 case -ECONNREFUSED:
137 case -ENOTCONN:
138 case -ECONNRESET:
139 case -EPIPE:
140 case -EHOSTDOWN:
141 case -EHOSTUNREACH:
142 case -ETIMEDOUT:
143 case -ECONNABORTED:
144 case -ENETDOWN:
145 case -ENETUNREACH:
146 case -ENETRESET:
147 case -ESHUTDOWN:
148 case -ENOPROTOOPT:
149 case -EINVAL: /* if returned from our tcp code,
150 this means there is no socket */
151 return 1;
153 return 0;
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
176 * received.
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;
206 dlm = mle->dlm;
208 assert_spin_locked(&dlm->spinlock);
209 assert_spin_locked(&dlm->master_lock);
210 mle->inuse++;
211 kref_get(&mle->mle_refs);
214 static void dlm_put_mle_inuse(struct dlm_master_list_entry *mle)
216 struct dlm_ctxt *dlm;
217 dlm = mle->dlm;
219 spin_lock(&dlm->spinlock);
220 spin_lock(&dlm->master_lock);
221 mle->inuse--;
222 __dlm_put_mle(mle);
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;
232 dlm = mle->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.
238 * it's a BUG. */
239 mlog(ML_ERROR, "bad mle: %p\n", mle);
240 dlm_print_one_mle(mle);
241 BUG();
242 } else
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;
251 dlm = mle->dlm;
253 spin_lock(&dlm->spinlock);
254 spin_lock(&dlm->master_lock);
255 __dlm_put_mle(mle);
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,
269 const char *name,
270 unsigned int namelen)
272 assert_spin_locked(&dlm->spinlock);
274 mle->dlm = dlm;
275 mle->type = type;
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;
286 mle->inuse = 0;
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) {
293 BUG_ON(!res);
294 mle->mleres = res;
295 memcpy(mle->mname, res->lockname.name, res->lockname.len);
296 mle->mnamelen = res->lockname.len;
297 mle->mnamehash = res->lockname.hash;
298 } else {
299 BUG_ON(!name);
300 mle->mleres = NULL;
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 unsigned int hash;
347 assert_spin_locked(&dlm->master_lock);
349 hash = dlm_lockid_hash(name, namelen);
350 bucket = dlm_master_hash(dlm, hash);
351 hlist_for_each_entry(tmpmle, bucket, master_hash_node) {
352 if (!dlm_mle_equal(dlm, tmpmle, name, namelen))
353 continue;
354 dlm_get_mle(tmpmle);
355 *mle = tmpmle;
356 return 1;
358 return 0;
361 void dlm_hb_event_notify_attached(struct dlm_ctxt *dlm, int idx, int node_up)
363 struct dlm_master_list_entry *mle;
365 assert_spin_locked(&dlm->spinlock);
367 list_for_each_entry(mle, &dlm->mle_hb_events, hb_events) {
368 if (node_up)
369 dlm_mle_node_up(dlm, mle, NULL, idx);
370 else
371 dlm_mle_node_down(dlm, mle, NULL, idx);
375 static void dlm_mle_node_down(struct dlm_ctxt *dlm,
376 struct dlm_master_list_entry *mle,
377 struct o2nm_node *node, int idx)
379 spin_lock(&mle->spinlock);
381 if (!test_bit(idx, mle->node_map))
382 mlog(0, "node %u already removed from nodemap!\n", idx);
383 else
384 clear_bit(idx, mle->node_map);
386 spin_unlock(&mle->spinlock);
389 static void dlm_mle_node_up(struct dlm_ctxt *dlm,
390 struct dlm_master_list_entry *mle,
391 struct o2nm_node *node, int idx)
393 spin_lock(&mle->spinlock);
395 if (test_bit(idx, mle->node_map))
396 mlog(0, "node %u already in node map!\n", idx);
397 else
398 set_bit(idx, mle->node_map);
400 spin_unlock(&mle->spinlock);
404 int dlm_init_mle_cache(void)
406 dlm_mle_cache = kmem_cache_create("o2dlm_mle",
407 sizeof(struct dlm_master_list_entry),
408 0, SLAB_HWCACHE_ALIGN,
409 NULL);
410 if (dlm_mle_cache == NULL)
411 return -ENOMEM;
412 return 0;
415 void dlm_destroy_mle_cache(void)
417 if (dlm_mle_cache)
418 kmem_cache_destroy(dlm_mle_cache);
421 static void dlm_mle_release(struct kref *kref)
423 struct dlm_master_list_entry *mle;
424 struct dlm_ctxt *dlm;
426 mle = container_of(kref, struct dlm_master_list_entry, mle_refs);
427 dlm = mle->dlm;
429 assert_spin_locked(&dlm->spinlock);
430 assert_spin_locked(&dlm->master_lock);
432 mlog(0, "Releasing mle for %.*s, type %d\n", mle->mnamelen, mle->mname,
433 mle->type);
435 /* remove from list if not already */
436 __dlm_unlink_mle(dlm, mle);
438 /* detach the mle from the domain node up/down events */
439 __dlm_mle_detach_hb_events(dlm, mle);
441 atomic_dec(&dlm->mle_cur_count[mle->type]);
443 /* NOTE: kfree under spinlock here.
444 * if this is bad, we can move this to a freelist. */
445 kmem_cache_free(dlm_mle_cache, mle);
450 * LOCK RESOURCE FUNCTIONS
453 int dlm_init_master_caches(void)
455 dlm_lockres_cache = kmem_cache_create("o2dlm_lockres",
456 sizeof(struct dlm_lock_resource),
457 0, SLAB_HWCACHE_ALIGN, NULL);
458 if (!dlm_lockres_cache)
459 goto bail;
461 dlm_lockname_cache = kmem_cache_create("o2dlm_lockname",
462 DLM_LOCKID_NAME_MAX, 0,
463 SLAB_HWCACHE_ALIGN, NULL);
464 if (!dlm_lockname_cache)
465 goto bail;
467 return 0;
468 bail:
469 dlm_destroy_master_caches();
470 return -ENOMEM;
473 void dlm_destroy_master_caches(void)
475 if (dlm_lockname_cache) {
476 kmem_cache_destroy(dlm_lockname_cache);
477 dlm_lockname_cache = NULL;
480 if (dlm_lockres_cache) {
481 kmem_cache_destroy(dlm_lockres_cache);
482 dlm_lockres_cache = NULL;
486 static void dlm_lockres_release(struct kref *kref)
488 struct dlm_lock_resource *res;
489 struct dlm_ctxt *dlm;
491 res = container_of(kref, struct dlm_lock_resource, refs);
492 dlm = res->dlm;
494 /* This should not happen -- all lockres' have a name
495 * associated with them at init time. */
496 BUG_ON(!res->lockname.name);
498 mlog(0, "destroying lockres %.*s\n", res->lockname.len,
499 res->lockname.name);
501 spin_lock(&dlm->track_lock);
502 if (!list_empty(&res->tracking))
503 list_del_init(&res->tracking);
504 else {
505 mlog(ML_ERROR, "Resource %.*s not on the Tracking list\n",
506 res->lockname.len, res->lockname.name);
507 dlm_print_one_lock_resource(res);
509 spin_unlock(&dlm->track_lock);
511 atomic_dec(&dlm->res_cur_count);
513 if (!hlist_unhashed(&res->hash_node) ||
514 !list_empty(&res->granted) ||
515 !list_empty(&res->converting) ||
516 !list_empty(&res->blocked) ||
517 !list_empty(&res->dirty) ||
518 !list_empty(&res->recovering) ||
519 !list_empty(&res->purge)) {
520 mlog(ML_ERROR,
521 "Going to BUG for resource %.*s."
522 " We're on a list! [%c%c%c%c%c%c%c]\n",
523 res->lockname.len, res->lockname.name,
524 !hlist_unhashed(&res->hash_node) ? 'H' : ' ',
525 !list_empty(&res->granted) ? 'G' : ' ',
526 !list_empty(&res->converting) ? 'C' : ' ',
527 !list_empty(&res->blocked) ? 'B' : ' ',
528 !list_empty(&res->dirty) ? 'D' : ' ',
529 !list_empty(&res->recovering) ? 'R' : ' ',
530 !list_empty(&res->purge) ? 'P' : ' ');
532 dlm_print_one_lock_resource(res);
535 /* By the time we're ready to blow this guy away, we shouldn't
536 * be on any lists. */
537 BUG_ON(!hlist_unhashed(&res->hash_node));
538 BUG_ON(!list_empty(&res->granted));
539 BUG_ON(!list_empty(&res->converting));
540 BUG_ON(!list_empty(&res->blocked));
541 BUG_ON(!list_empty(&res->dirty));
542 BUG_ON(!list_empty(&res->recovering));
543 BUG_ON(!list_empty(&res->purge));
545 kmem_cache_free(dlm_lockname_cache, (void *)res->lockname.name);
547 kmem_cache_free(dlm_lockres_cache, res);
550 void dlm_lockres_put(struct dlm_lock_resource *res)
552 kref_put(&res->refs, dlm_lockres_release);
555 static void dlm_init_lockres(struct dlm_ctxt *dlm,
556 struct dlm_lock_resource *res,
557 const char *name, unsigned int namelen)
559 char *qname;
561 /* If we memset here, we lose our reference to the kmalloc'd
562 * res->lockname.name, so be sure to init every field
563 * correctly! */
565 qname = (char *) res->lockname.name;
566 memcpy(qname, name, namelen);
568 res->lockname.len = namelen;
569 res->lockname.hash = dlm_lockid_hash(name, namelen);
571 init_waitqueue_head(&res->wq);
572 spin_lock_init(&res->spinlock);
573 INIT_HLIST_NODE(&res->hash_node);
574 INIT_LIST_HEAD(&res->granted);
575 INIT_LIST_HEAD(&res->converting);
576 INIT_LIST_HEAD(&res->blocked);
577 INIT_LIST_HEAD(&res->dirty);
578 INIT_LIST_HEAD(&res->recovering);
579 INIT_LIST_HEAD(&res->purge);
580 INIT_LIST_HEAD(&res->tracking);
581 atomic_set(&res->asts_reserved, 0);
582 res->migration_pending = 0;
583 res->inflight_locks = 0;
584 res->inflight_assert_workers = 0;
586 res->dlm = dlm;
588 kref_init(&res->refs);
590 atomic_inc(&dlm->res_tot_count);
591 atomic_inc(&dlm->res_cur_count);
593 /* just for consistency */
594 spin_lock(&res->spinlock);
595 dlm_set_lockres_owner(dlm, res, DLM_LOCK_RES_OWNER_UNKNOWN);
596 spin_unlock(&res->spinlock);
598 res->state = DLM_LOCK_RES_IN_PROGRESS;
600 res->last_used = 0;
602 spin_lock(&dlm->spinlock);
603 list_add_tail(&res->tracking, &dlm->tracking_list);
604 spin_unlock(&dlm->spinlock);
606 memset(res->lvb, 0, DLM_LVB_LEN);
607 memset(res->refmap, 0, sizeof(res->refmap));
610 struct dlm_lock_resource *dlm_new_lockres(struct dlm_ctxt *dlm,
611 const char *name,
612 unsigned int namelen)
614 struct dlm_lock_resource *res = NULL;
616 res = kmem_cache_zalloc(dlm_lockres_cache, GFP_NOFS);
617 if (!res)
618 goto error;
620 res->lockname.name = kmem_cache_zalloc(dlm_lockname_cache, GFP_NOFS);
621 if (!res->lockname.name)
622 goto error;
624 dlm_init_lockres(dlm, res, name, namelen);
625 return res;
627 error:
628 if (res)
629 kmem_cache_free(dlm_lockres_cache, res);
630 return NULL;
633 void dlm_lockres_set_refmap_bit(struct dlm_ctxt *dlm,
634 struct dlm_lock_resource *res, int bit)
636 assert_spin_locked(&res->spinlock);
638 mlog(0, "res %.*s, set node %u, %ps()\n", res->lockname.len,
639 res->lockname.name, bit, __builtin_return_address(0));
641 set_bit(bit, res->refmap);
644 void dlm_lockres_clear_refmap_bit(struct dlm_ctxt *dlm,
645 struct dlm_lock_resource *res, int bit)
647 assert_spin_locked(&res->spinlock);
649 mlog(0, "res %.*s, clr node %u, %ps()\n", res->lockname.len,
650 res->lockname.name, bit, __builtin_return_address(0));
652 clear_bit(bit, res->refmap);
655 static void __dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm,
656 struct dlm_lock_resource *res)
658 res->inflight_locks++;
660 mlog(0, "%s: res %.*s, inflight++: now %u, %ps()\n", dlm->name,
661 res->lockname.len, res->lockname.name, res->inflight_locks,
662 __builtin_return_address(0));
665 void dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm,
666 struct dlm_lock_resource *res)
668 assert_spin_locked(&res->spinlock);
669 __dlm_lockres_grab_inflight_ref(dlm, res);
672 void dlm_lockres_drop_inflight_ref(struct dlm_ctxt *dlm,
673 struct dlm_lock_resource *res)
675 assert_spin_locked(&res->spinlock);
677 BUG_ON(res->inflight_locks == 0);
679 res->inflight_locks--;
681 mlog(0, "%s: res %.*s, inflight--: now %u, %ps()\n", dlm->name,
682 res->lockname.len, res->lockname.name, res->inflight_locks,
683 __builtin_return_address(0));
685 wake_up(&res->wq);
688 void __dlm_lockres_grab_inflight_worker(struct dlm_ctxt *dlm,
689 struct dlm_lock_resource *res)
691 assert_spin_locked(&res->spinlock);
692 res->inflight_assert_workers++;
693 mlog(0, "%s:%.*s: inflight assert worker++: now %u\n",
694 dlm->name, res->lockname.len, res->lockname.name,
695 res->inflight_assert_workers);
698 static void __dlm_lockres_drop_inflight_worker(struct dlm_ctxt *dlm,
699 struct dlm_lock_resource *res)
701 assert_spin_locked(&res->spinlock);
702 BUG_ON(res->inflight_assert_workers == 0);
703 res->inflight_assert_workers--;
704 mlog(0, "%s:%.*s: inflight assert worker--: now %u\n",
705 dlm->name, res->lockname.len, res->lockname.name,
706 res->inflight_assert_workers);
709 static void dlm_lockres_drop_inflight_worker(struct dlm_ctxt *dlm,
710 struct dlm_lock_resource *res)
712 spin_lock(&res->spinlock);
713 __dlm_lockres_drop_inflight_worker(dlm, res);
714 spin_unlock(&res->spinlock);
718 * lookup a lock resource by name.
719 * may already exist in the hashtable.
720 * lockid is null terminated
722 * if not, allocate enough for the lockres and for
723 * the temporary structure used in doing the mastering.
725 * also, do a lookup in the dlm->master_list to see
726 * if another node has begun mastering the same lock.
727 * if so, there should be a block entry in there
728 * for this name, and we should *not* attempt to master
729 * the lock here. need to wait around for that node
730 * to assert_master (or die).
733 struct dlm_lock_resource * dlm_get_lock_resource(struct dlm_ctxt *dlm,
734 const char *lockid,
735 int namelen,
736 int flags)
738 struct dlm_lock_resource *tmpres=NULL, *res=NULL;
739 struct dlm_master_list_entry *mle = NULL;
740 struct dlm_master_list_entry *alloc_mle = NULL;
741 int blocked = 0;
742 int ret, nodenum;
743 struct dlm_node_iter iter;
744 unsigned int hash;
745 int tries = 0;
746 int bit, wait_on_recovery = 0;
748 BUG_ON(!lockid);
750 hash = dlm_lockid_hash(lockid, namelen);
752 mlog(0, "get lockres %s (len %d)\n", lockid, namelen);
754 lookup:
755 spin_lock(&dlm->spinlock);
756 tmpres = __dlm_lookup_lockres_full(dlm, lockid, namelen, hash);
757 if (tmpres) {
758 spin_unlock(&dlm->spinlock);
759 spin_lock(&tmpres->spinlock);
762 * Right after dlm spinlock was released, dlm_thread could have
763 * purged the lockres. Check if lockres got unhashed. If so
764 * start over.
766 if (hlist_unhashed(&tmpres->hash_node)) {
767 spin_unlock(&tmpres->spinlock);
768 dlm_lockres_put(tmpres);
769 tmpres = NULL;
770 goto lookup;
773 /* Wait on the thread that is mastering the resource */
774 if (tmpres->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
775 __dlm_wait_on_lockres(tmpres);
776 BUG_ON(tmpres->owner == DLM_LOCK_RES_OWNER_UNKNOWN);
777 spin_unlock(&tmpres->spinlock);
778 dlm_lockres_put(tmpres);
779 tmpres = NULL;
780 goto lookup;
783 /* Wait on the resource purge to complete before continuing */
784 if (tmpres->state & DLM_LOCK_RES_DROPPING_REF) {
785 BUG_ON(tmpres->owner == dlm->node_num);
786 __dlm_wait_on_lockres_flags(tmpres,
787 DLM_LOCK_RES_DROPPING_REF);
788 spin_unlock(&tmpres->spinlock);
789 dlm_lockres_put(tmpres);
790 tmpres = NULL;
791 goto lookup;
794 /* Grab inflight ref to pin the resource */
795 dlm_lockres_grab_inflight_ref(dlm, tmpres);
797 spin_unlock(&tmpres->spinlock);
798 if (res)
799 dlm_lockres_put(res);
800 res = tmpres;
801 goto leave;
804 if (!res) {
805 spin_unlock(&dlm->spinlock);
806 mlog(0, "allocating a new resource\n");
807 /* nothing found and we need to allocate one. */
808 alloc_mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
809 if (!alloc_mle)
810 goto leave;
811 res = dlm_new_lockres(dlm, lockid, namelen);
812 if (!res)
813 goto leave;
814 goto lookup;
817 mlog(0, "no lockres found, allocated our own: %p\n", res);
819 if (flags & LKM_LOCAL) {
820 /* caller knows it's safe to assume it's not mastered elsewhere
821 * DONE! return right away */
822 spin_lock(&res->spinlock);
823 dlm_change_lockres_owner(dlm, res, dlm->node_num);
824 __dlm_insert_lockres(dlm, res);
825 dlm_lockres_grab_inflight_ref(dlm, res);
826 spin_unlock(&res->spinlock);
827 spin_unlock(&dlm->spinlock);
828 /* lockres still marked IN_PROGRESS */
829 goto wake_waiters;
832 /* check master list to see if another node has started mastering it */
833 spin_lock(&dlm->master_lock);
835 /* if we found a block, wait for lock to be mastered by another node */
836 blocked = dlm_find_mle(dlm, &mle, (char *)lockid, namelen);
837 if (blocked) {
838 int mig;
839 if (mle->type == DLM_MLE_MASTER) {
840 mlog(ML_ERROR, "master entry for nonexistent lock!\n");
841 BUG();
843 mig = (mle->type == DLM_MLE_MIGRATION);
844 /* if there is a migration in progress, let the migration
845 * finish before continuing. we can wait for the absence
846 * of the MIGRATION mle: either the migrate finished or
847 * one of the nodes died and the mle was cleaned up.
848 * if there is a BLOCK here, but it already has a master
849 * set, we are too late. the master does not have a ref
850 * for us in the refmap. detach the mle and drop it.
851 * either way, go back to the top and start over. */
852 if (mig || mle->master != O2NM_MAX_NODES) {
853 BUG_ON(mig && mle->master == dlm->node_num);
854 /* we arrived too late. the master does not
855 * have a ref for us. retry. */
856 mlog(0, "%s:%.*s: late on %s\n",
857 dlm->name, namelen, lockid,
858 mig ? "MIGRATION" : "BLOCK");
859 spin_unlock(&dlm->master_lock);
860 spin_unlock(&dlm->spinlock);
862 /* master is known, detach */
863 if (!mig)
864 dlm_mle_detach_hb_events(dlm, mle);
865 dlm_put_mle(mle);
866 mle = NULL;
867 /* this is lame, but we can't wait on either
868 * the mle or lockres waitqueue here */
869 if (mig)
870 msleep(100);
871 goto lookup;
873 } else {
874 /* go ahead and try to master lock on this node */
875 mle = alloc_mle;
876 /* make sure this does not get freed below */
877 alloc_mle = NULL;
878 dlm_init_mle(mle, DLM_MLE_MASTER, dlm, res, NULL, 0);
879 set_bit(dlm->node_num, mle->maybe_map);
880 __dlm_insert_mle(dlm, mle);
882 /* still holding the dlm spinlock, check the recovery map
883 * to see if there are any nodes that still need to be
884 * considered. these will not appear in the mle nodemap
885 * but they might own this lockres. wait on them. */
886 bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0);
887 if (bit < O2NM_MAX_NODES) {
888 mlog(0, "%s: res %.*s, At least one node (%d) "
889 "to recover before lock mastery can begin\n",
890 dlm->name, namelen, (char *)lockid, bit);
891 wait_on_recovery = 1;
895 /* at this point there is either a DLM_MLE_BLOCK or a
896 * DLM_MLE_MASTER on the master list, so it's safe to add the
897 * lockres to the hashtable. anyone who finds the lock will
898 * still have to wait on the IN_PROGRESS. */
900 /* finally add the lockres to its hash bucket */
901 __dlm_insert_lockres(dlm, res);
903 /* since this lockres is new it doesn't not require the spinlock */
904 __dlm_lockres_grab_inflight_ref(dlm, res);
906 /* get an extra ref on the mle in case this is a BLOCK
907 * if so, the creator of the BLOCK may try to put the last
908 * ref at this time in the assert master handler, so we
909 * need an extra one to keep from a bad ptr deref. */
910 dlm_get_mle_inuse(mle);
911 spin_unlock(&dlm->master_lock);
912 spin_unlock(&dlm->spinlock);
914 redo_request:
915 while (wait_on_recovery) {
916 /* any cluster changes that occurred after dropping the
917 * dlm spinlock would be detectable be a change on the mle,
918 * so we only need to clear out the recovery map once. */
919 if (dlm_is_recovery_lock(lockid, namelen)) {
920 mlog(0, "%s: Recovery map is not empty, but must "
921 "master $RECOVERY lock now\n", dlm->name);
922 if (!dlm_pre_master_reco_lockres(dlm, res))
923 wait_on_recovery = 0;
924 else {
925 mlog(0, "%s: waiting 500ms for heartbeat state "
926 "change\n", dlm->name);
927 msleep(500);
929 continue;
932 dlm_kick_recovery_thread(dlm);
933 msleep(1000);
934 dlm_wait_for_recovery(dlm);
936 spin_lock(&dlm->spinlock);
937 bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0);
938 if (bit < O2NM_MAX_NODES) {
939 mlog(0, "%s: res %.*s, At least one node (%d) "
940 "to recover before lock mastery can begin\n",
941 dlm->name, namelen, (char *)lockid, bit);
942 wait_on_recovery = 1;
943 } else
944 wait_on_recovery = 0;
945 spin_unlock(&dlm->spinlock);
947 if (wait_on_recovery)
948 dlm_wait_for_node_recovery(dlm, bit, 10000);
951 /* must wait for lock to be mastered elsewhere */
952 if (blocked)
953 goto wait;
955 ret = -EINVAL;
956 dlm_node_iter_init(mle->vote_map, &iter);
957 while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
958 ret = dlm_do_master_request(res, mle, nodenum);
959 if (ret < 0)
960 mlog_errno(ret);
961 if (mle->master != O2NM_MAX_NODES) {
962 /* found a master ! */
963 if (mle->master <= nodenum)
964 break;
965 /* if our master request has not reached the master
966 * yet, keep going until it does. this is how the
967 * master will know that asserts are needed back to
968 * the lower nodes. */
969 mlog(0, "%s: res %.*s, Requests only up to %u but "
970 "master is %u, keep going\n", dlm->name, namelen,
971 lockid, nodenum, mle->master);
975 wait:
976 /* keep going until the response map includes all nodes */
977 ret = dlm_wait_for_lock_mastery(dlm, res, mle, &blocked);
978 if (ret < 0) {
979 wait_on_recovery = 1;
980 mlog(0, "%s: res %.*s, Node map changed, redo the master "
981 "request now, blocked=%d\n", dlm->name, res->lockname.len,
982 res->lockname.name, blocked);
983 if (++tries > 20) {
984 mlog(ML_ERROR, "%s: res %.*s, Spinning on "
985 "dlm_wait_for_lock_mastery, blocked = %d\n",
986 dlm->name, res->lockname.len,
987 res->lockname.name, blocked);
988 dlm_print_one_lock_resource(res);
989 dlm_print_one_mle(mle);
990 tries = 0;
992 goto redo_request;
995 mlog(0, "%s: res %.*s, Mastered by %u\n", dlm->name, res->lockname.len,
996 res->lockname.name, res->owner);
997 /* make sure we never continue without this */
998 BUG_ON(res->owner == O2NM_MAX_NODES);
1000 /* master is known, detach if not already detached */
1001 dlm_mle_detach_hb_events(dlm, mle);
1002 dlm_put_mle(mle);
1003 /* put the extra ref */
1004 dlm_put_mle_inuse(mle);
1006 wake_waiters:
1007 spin_lock(&res->spinlock);
1008 res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
1009 spin_unlock(&res->spinlock);
1010 wake_up(&res->wq);
1012 leave:
1013 /* need to free the unused mle */
1014 if (alloc_mle)
1015 kmem_cache_free(dlm_mle_cache, alloc_mle);
1017 return res;
1021 #define DLM_MASTERY_TIMEOUT_MS 5000
1023 static int dlm_wait_for_lock_mastery(struct dlm_ctxt *dlm,
1024 struct dlm_lock_resource *res,
1025 struct dlm_master_list_entry *mle,
1026 int *blocked)
1028 u8 m;
1029 int ret, bit;
1030 int map_changed, voting_done;
1031 int assert, sleep;
1033 recheck:
1034 ret = 0;
1035 assert = 0;
1037 /* check if another node has already become the owner */
1038 spin_lock(&res->spinlock);
1039 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
1040 mlog(0, "%s:%.*s: owner is suddenly %u\n", dlm->name,
1041 res->lockname.len, res->lockname.name, res->owner);
1042 spin_unlock(&res->spinlock);
1043 /* this will cause the master to re-assert across
1044 * the whole cluster, freeing up mles */
1045 if (res->owner != dlm->node_num) {
1046 ret = dlm_do_master_request(res, mle, res->owner);
1047 if (ret < 0) {
1048 /* give recovery a chance to run */
1049 mlog(ML_ERROR, "link to %u went down?: %d\n", res->owner, ret);
1050 msleep(500);
1051 goto recheck;
1054 ret = 0;
1055 goto leave;
1057 spin_unlock(&res->spinlock);
1059 spin_lock(&mle->spinlock);
1060 m = mle->master;
1061 map_changed = (memcmp(mle->vote_map, mle->node_map,
1062 sizeof(mle->vote_map)) != 0);
1063 voting_done = (memcmp(mle->vote_map, mle->response_map,
1064 sizeof(mle->vote_map)) == 0);
1066 /* restart if we hit any errors */
1067 if (map_changed) {
1068 int b;
1069 mlog(0, "%s: %.*s: node map changed, restarting\n",
1070 dlm->name, res->lockname.len, res->lockname.name);
1071 ret = dlm_restart_lock_mastery(dlm, res, mle, *blocked);
1072 b = (mle->type == DLM_MLE_BLOCK);
1073 if ((*blocked && !b) || (!*blocked && b)) {
1074 mlog(0, "%s:%.*s: status change: old=%d new=%d\n",
1075 dlm->name, res->lockname.len, res->lockname.name,
1076 *blocked, b);
1077 *blocked = b;
1079 spin_unlock(&mle->spinlock);
1080 if (ret < 0) {
1081 mlog_errno(ret);
1082 goto leave;
1084 mlog(0, "%s:%.*s: restart lock mastery succeeded, "
1085 "rechecking now\n", dlm->name, res->lockname.len,
1086 res->lockname.name);
1087 goto recheck;
1088 } else {
1089 if (!voting_done) {
1090 mlog(0, "map not changed and voting not done "
1091 "for %s:%.*s\n", dlm->name, res->lockname.len,
1092 res->lockname.name);
1096 if (m != O2NM_MAX_NODES) {
1097 /* another node has done an assert!
1098 * all done! */
1099 sleep = 0;
1100 } else {
1101 sleep = 1;
1102 /* have all nodes responded? */
1103 if (voting_done && !*blocked) {
1104 bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0);
1105 if (dlm->node_num <= bit) {
1106 /* my node number is lowest.
1107 * now tell other nodes that I am
1108 * mastering this. */
1109 mle->master = dlm->node_num;
1110 /* ref was grabbed in get_lock_resource
1111 * will be dropped in dlmlock_master */
1112 assert = 1;
1113 sleep = 0;
1115 /* if voting is done, but we have not received
1116 * an assert master yet, we must sleep */
1120 spin_unlock(&mle->spinlock);
1122 /* sleep if we haven't finished voting yet */
1123 if (sleep) {
1124 unsigned long timeo = msecs_to_jiffies(DLM_MASTERY_TIMEOUT_MS);
1127 if (atomic_read(&mle->mle_refs.refcount) < 2)
1128 mlog(ML_ERROR, "mle (%p) refs=%d, name=%.*s\n", mle,
1129 atomic_read(&mle->mle_refs.refcount),
1130 res->lockname.len, res->lockname.name);
1132 atomic_set(&mle->woken, 0);
1133 (void)wait_event_timeout(mle->wq,
1134 (atomic_read(&mle->woken) == 1),
1135 timeo);
1136 if (res->owner == O2NM_MAX_NODES) {
1137 mlog(0, "%s:%.*s: waiting again\n", dlm->name,
1138 res->lockname.len, res->lockname.name);
1139 goto recheck;
1141 mlog(0, "done waiting, master is %u\n", res->owner);
1142 ret = 0;
1143 goto leave;
1146 ret = 0; /* done */
1147 if (assert) {
1148 m = dlm->node_num;
1149 mlog(0, "about to master %.*s here, this=%u\n",
1150 res->lockname.len, res->lockname.name, m);
1151 ret = dlm_do_assert_master(dlm, res, mle->vote_map, 0);
1152 if (ret) {
1153 /* This is a failure in the network path,
1154 * not in the response to the assert_master
1155 * (any nonzero response is a BUG on this node).
1156 * Most likely a socket just got disconnected
1157 * due to node death. */
1158 mlog_errno(ret);
1160 /* no longer need to restart lock mastery.
1161 * all living nodes have been contacted. */
1162 ret = 0;
1165 /* set the lockres owner */
1166 spin_lock(&res->spinlock);
1167 /* mastery reference obtained either during
1168 * assert_master_handler or in get_lock_resource */
1169 dlm_change_lockres_owner(dlm, res, m);
1170 spin_unlock(&res->spinlock);
1172 leave:
1173 return ret;
1176 struct dlm_bitmap_diff_iter
1178 int curnode;
1179 unsigned long *orig_bm;
1180 unsigned long *cur_bm;
1181 unsigned long diff_bm[BITS_TO_LONGS(O2NM_MAX_NODES)];
1184 enum dlm_node_state_change
1186 NODE_DOWN = -1,
1187 NODE_NO_CHANGE = 0,
1188 NODE_UP
1191 static void dlm_bitmap_diff_iter_init(struct dlm_bitmap_diff_iter *iter,
1192 unsigned long *orig_bm,
1193 unsigned long *cur_bm)
1195 unsigned long p1, p2;
1196 int i;
1198 iter->curnode = -1;
1199 iter->orig_bm = orig_bm;
1200 iter->cur_bm = cur_bm;
1202 for (i = 0; i < BITS_TO_LONGS(O2NM_MAX_NODES); i++) {
1203 p1 = *(iter->orig_bm + i);
1204 p2 = *(iter->cur_bm + i);
1205 iter->diff_bm[i] = (p1 & ~p2) | (p2 & ~p1);
1209 static int dlm_bitmap_diff_iter_next(struct dlm_bitmap_diff_iter *iter,
1210 enum dlm_node_state_change *state)
1212 int bit;
1214 if (iter->curnode >= O2NM_MAX_NODES)
1215 return -ENOENT;
1217 bit = find_next_bit(iter->diff_bm, O2NM_MAX_NODES,
1218 iter->curnode+1);
1219 if (bit >= O2NM_MAX_NODES) {
1220 iter->curnode = O2NM_MAX_NODES;
1221 return -ENOENT;
1224 /* if it was there in the original then this node died */
1225 if (test_bit(bit, iter->orig_bm))
1226 *state = NODE_DOWN;
1227 else
1228 *state = NODE_UP;
1230 iter->curnode = bit;
1231 return bit;
1235 static int dlm_restart_lock_mastery(struct dlm_ctxt *dlm,
1236 struct dlm_lock_resource *res,
1237 struct dlm_master_list_entry *mle,
1238 int blocked)
1240 struct dlm_bitmap_diff_iter bdi;
1241 enum dlm_node_state_change sc;
1242 int node;
1243 int ret = 0;
1245 mlog(0, "something happened such that the "
1246 "master process may need to be restarted!\n");
1248 assert_spin_locked(&mle->spinlock);
1250 dlm_bitmap_diff_iter_init(&bdi, mle->vote_map, mle->node_map);
1251 node = dlm_bitmap_diff_iter_next(&bdi, &sc);
1252 while (node >= 0) {
1253 if (sc == NODE_UP) {
1254 /* a node came up. clear any old vote from
1255 * the response map and set it in the vote map
1256 * then restart the mastery. */
1257 mlog(ML_NOTICE, "node %d up while restarting\n", node);
1259 /* redo the master request, but only for the new node */
1260 mlog(0, "sending request to new node\n");
1261 clear_bit(node, mle->response_map);
1262 set_bit(node, mle->vote_map);
1263 } else {
1264 mlog(ML_ERROR, "node down! %d\n", node);
1265 if (blocked) {
1266 int lowest = find_next_bit(mle->maybe_map,
1267 O2NM_MAX_NODES, 0);
1269 /* act like it was never there */
1270 clear_bit(node, mle->maybe_map);
1272 if (node == lowest) {
1273 mlog(0, "expected master %u died"
1274 " while this node was blocked "
1275 "waiting on it!\n", node);
1276 lowest = find_next_bit(mle->maybe_map,
1277 O2NM_MAX_NODES,
1278 lowest+1);
1279 if (lowest < O2NM_MAX_NODES) {
1280 mlog(0, "%s:%.*s:still "
1281 "blocked. waiting on %u "
1282 "now\n", dlm->name,
1283 res->lockname.len,
1284 res->lockname.name,
1285 lowest);
1286 } else {
1287 /* mle is an MLE_BLOCK, but
1288 * there is now nothing left to
1289 * block on. we need to return
1290 * all the way back out and try
1291 * again with an MLE_MASTER.
1292 * dlm_do_local_recovery_cleanup
1293 * has already run, so the mle
1294 * refcount is ok */
1295 mlog(0, "%s:%.*s: no "
1296 "longer blocking. try to "
1297 "master this here\n",
1298 dlm->name,
1299 res->lockname.len,
1300 res->lockname.name);
1301 mle->type = DLM_MLE_MASTER;
1302 mle->mleres = res;
1307 /* now blank out everything, as if we had never
1308 * contacted anyone */
1309 memset(mle->maybe_map, 0, sizeof(mle->maybe_map));
1310 memset(mle->response_map, 0, sizeof(mle->response_map));
1311 /* reset the vote_map to the current node_map */
1312 memcpy(mle->vote_map, mle->node_map,
1313 sizeof(mle->node_map));
1314 /* put myself into the maybe map */
1315 if (mle->type != DLM_MLE_BLOCK)
1316 set_bit(dlm->node_num, mle->maybe_map);
1318 ret = -EAGAIN;
1319 node = dlm_bitmap_diff_iter_next(&bdi, &sc);
1321 return ret;
1326 * DLM_MASTER_REQUEST_MSG
1328 * returns: 0 on success,
1329 * -errno on a network error
1331 * on error, the caller should assume the target node is "dead"
1335 static int dlm_do_master_request(struct dlm_lock_resource *res,
1336 struct dlm_master_list_entry *mle, int to)
1338 struct dlm_ctxt *dlm = mle->dlm;
1339 struct dlm_master_request request;
1340 int ret, response=0, resend;
1342 memset(&request, 0, sizeof(request));
1343 request.node_idx = dlm->node_num;
1345 BUG_ON(mle->type == DLM_MLE_MIGRATION);
1347 request.namelen = (u8)mle->mnamelen;
1348 memcpy(request.name, mle->mname, request.namelen);
1350 again:
1351 ret = o2net_send_message(DLM_MASTER_REQUEST_MSG, dlm->key, &request,
1352 sizeof(request), to, &response);
1353 if (ret < 0) {
1354 if (ret == -ESRCH) {
1355 /* should never happen */
1356 mlog(ML_ERROR, "TCP stack not ready!\n");
1357 BUG();
1358 } else if (ret == -EINVAL) {
1359 mlog(ML_ERROR, "bad args passed to o2net!\n");
1360 BUG();
1361 } else if (ret == -ENOMEM) {
1362 mlog(ML_ERROR, "out of memory while trying to send "
1363 "network message! retrying\n");
1364 /* this is totally crude */
1365 msleep(50);
1366 goto again;
1367 } else if (!dlm_is_host_down(ret)) {
1368 /* not a network error. bad. */
1369 mlog_errno(ret);
1370 mlog(ML_ERROR, "unhandled error!");
1371 BUG();
1373 /* all other errors should be network errors,
1374 * and likely indicate node death */
1375 mlog(ML_ERROR, "link to %d went down!\n", to);
1376 goto out;
1379 ret = 0;
1380 resend = 0;
1381 spin_lock(&mle->spinlock);
1382 switch (response) {
1383 case DLM_MASTER_RESP_YES:
1384 set_bit(to, mle->response_map);
1385 mlog(0, "node %u is the master, response=YES\n", to);
1386 mlog(0, "%s:%.*s: master node %u now knows I have a "
1387 "reference\n", dlm->name, res->lockname.len,
1388 res->lockname.name, to);
1389 mle->master = to;
1390 break;
1391 case DLM_MASTER_RESP_NO:
1392 mlog(0, "node %u not master, response=NO\n", to);
1393 set_bit(to, mle->response_map);
1394 break;
1395 case DLM_MASTER_RESP_MAYBE:
1396 mlog(0, "node %u not master, response=MAYBE\n", to);
1397 set_bit(to, mle->response_map);
1398 set_bit(to, mle->maybe_map);
1399 break;
1400 case DLM_MASTER_RESP_ERROR:
1401 mlog(0, "node %u hit an error, resending\n", to);
1402 resend = 1;
1403 response = 0;
1404 break;
1405 default:
1406 mlog(ML_ERROR, "bad response! %u\n", response);
1407 BUG();
1409 spin_unlock(&mle->spinlock);
1410 if (resend) {
1411 /* this is also totally crude */
1412 msleep(50);
1413 goto again;
1416 out:
1417 return ret;
1421 * locks that can be taken here:
1422 * dlm->spinlock
1423 * res->spinlock
1424 * mle->spinlock
1425 * dlm->master_list
1427 * if possible, TRIM THIS DOWN!!!
1429 int dlm_master_request_handler(struct o2net_msg *msg, u32 len, void *data,
1430 void **ret_data)
1432 u8 response = DLM_MASTER_RESP_MAYBE;
1433 struct dlm_ctxt *dlm = data;
1434 struct dlm_lock_resource *res = NULL;
1435 struct dlm_master_request *request = (struct dlm_master_request *) msg->buf;
1436 struct dlm_master_list_entry *mle = NULL, *tmpmle = NULL;
1437 char *name;
1438 unsigned int namelen, hash;
1439 int found, ret;
1440 int set_maybe;
1441 int dispatch_assert = 0;
1443 if (!dlm_grab(dlm))
1444 return DLM_MASTER_RESP_NO;
1446 if (!dlm_domain_fully_joined(dlm)) {
1447 response = DLM_MASTER_RESP_NO;
1448 goto send_response;
1451 name = request->name;
1452 namelen = request->namelen;
1453 hash = dlm_lockid_hash(name, namelen);
1455 if (namelen > DLM_LOCKID_NAME_MAX) {
1456 response = DLM_IVBUFLEN;
1457 goto send_response;
1460 way_up_top:
1461 spin_lock(&dlm->spinlock);
1462 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
1463 if (res) {
1464 spin_unlock(&dlm->spinlock);
1466 /* take care of the easy cases up front */
1467 spin_lock(&res->spinlock);
1470 * Right after dlm spinlock was released, dlm_thread could have
1471 * purged the lockres. Check if lockres got unhashed. If so
1472 * start over.
1474 if (hlist_unhashed(&res->hash_node)) {
1475 spin_unlock(&res->spinlock);
1476 dlm_lockres_put(res);
1477 goto way_up_top;
1480 if (res->state & (DLM_LOCK_RES_RECOVERING|
1481 DLM_LOCK_RES_MIGRATING)) {
1482 spin_unlock(&res->spinlock);
1483 mlog(0, "returning DLM_MASTER_RESP_ERROR since res is "
1484 "being recovered/migrated\n");
1485 response = DLM_MASTER_RESP_ERROR;
1486 if (mle)
1487 kmem_cache_free(dlm_mle_cache, mle);
1488 goto send_response;
1491 if (res->owner == dlm->node_num) {
1492 dlm_lockres_set_refmap_bit(dlm, res, request->node_idx);
1493 spin_unlock(&res->spinlock);
1494 response = DLM_MASTER_RESP_YES;
1495 if (mle)
1496 kmem_cache_free(dlm_mle_cache, mle);
1498 /* this node is the owner.
1499 * there is some extra work that needs to
1500 * happen now. the requesting node has
1501 * caused all nodes up to this one to
1502 * create mles. this node now needs to
1503 * go back and clean those up. */
1504 dispatch_assert = 1;
1505 goto send_response;
1506 } else if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
1507 spin_unlock(&res->spinlock);
1508 // mlog(0, "node %u is the master\n", res->owner);
1509 response = DLM_MASTER_RESP_NO;
1510 if (mle)
1511 kmem_cache_free(dlm_mle_cache, mle);
1512 goto send_response;
1515 /* ok, there is no owner. either this node is
1516 * being blocked, or it is actively trying to
1517 * master this lock. */
1518 if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) {
1519 mlog(ML_ERROR, "lock with no owner should be "
1520 "in-progress!\n");
1521 BUG();
1524 // mlog(0, "lockres is in progress...\n");
1525 spin_lock(&dlm->master_lock);
1526 found = dlm_find_mle(dlm, &tmpmle, name, namelen);
1527 if (!found) {
1528 mlog(ML_ERROR, "no mle found for this lock!\n");
1529 BUG();
1531 set_maybe = 1;
1532 spin_lock(&tmpmle->spinlock);
1533 if (tmpmle->type == DLM_MLE_BLOCK) {
1534 // mlog(0, "this node is waiting for "
1535 // "lockres to be mastered\n");
1536 response = DLM_MASTER_RESP_NO;
1537 } else if (tmpmle->type == DLM_MLE_MIGRATION) {
1538 mlog(0, "node %u is master, but trying to migrate to "
1539 "node %u.\n", tmpmle->master, tmpmle->new_master);
1540 if (tmpmle->master == dlm->node_num) {
1541 mlog(ML_ERROR, "no owner on lockres, but this "
1542 "node is trying to migrate it to %u?!\n",
1543 tmpmle->new_master);
1544 BUG();
1545 } else {
1546 /* the real master can respond on its own */
1547 response = DLM_MASTER_RESP_NO;
1549 } else if (tmpmle->master != DLM_LOCK_RES_OWNER_UNKNOWN) {
1550 set_maybe = 0;
1551 if (tmpmle->master == dlm->node_num) {
1552 response = DLM_MASTER_RESP_YES;
1553 /* this node will be the owner.
1554 * go back and clean the mles on any
1555 * other nodes */
1556 dispatch_assert = 1;
1557 dlm_lockres_set_refmap_bit(dlm, res,
1558 request->node_idx);
1559 } else
1560 response = DLM_MASTER_RESP_NO;
1561 } else {
1562 // mlog(0, "this node is attempting to "
1563 // "master lockres\n");
1564 response = DLM_MASTER_RESP_MAYBE;
1566 if (set_maybe)
1567 set_bit(request->node_idx, tmpmle->maybe_map);
1568 spin_unlock(&tmpmle->spinlock);
1570 spin_unlock(&dlm->master_lock);
1571 spin_unlock(&res->spinlock);
1573 /* keep the mle attached to heartbeat events */
1574 dlm_put_mle(tmpmle);
1575 if (mle)
1576 kmem_cache_free(dlm_mle_cache, mle);
1577 goto send_response;
1581 * lockres doesn't exist on this node
1582 * if there is an MLE_BLOCK, return NO
1583 * if there is an MLE_MASTER, return MAYBE
1584 * otherwise, add an MLE_BLOCK, return NO
1586 spin_lock(&dlm->master_lock);
1587 found = dlm_find_mle(dlm, &tmpmle, name, namelen);
1588 if (!found) {
1589 /* this lockid has never been seen on this node yet */
1590 // mlog(0, "no mle found\n");
1591 if (!mle) {
1592 spin_unlock(&dlm->master_lock);
1593 spin_unlock(&dlm->spinlock);
1595 mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
1596 if (!mle) {
1597 response = DLM_MASTER_RESP_ERROR;
1598 mlog_errno(-ENOMEM);
1599 goto send_response;
1601 goto way_up_top;
1604 // mlog(0, "this is second time thru, already allocated, "
1605 // "add the block.\n");
1606 dlm_init_mle(mle, DLM_MLE_BLOCK, dlm, NULL, name, namelen);
1607 set_bit(request->node_idx, mle->maybe_map);
1608 __dlm_insert_mle(dlm, mle);
1609 response = DLM_MASTER_RESP_NO;
1610 } else {
1611 // mlog(0, "mle was found\n");
1612 set_maybe = 1;
1613 spin_lock(&tmpmle->spinlock);
1614 if (tmpmle->master == dlm->node_num) {
1615 mlog(ML_ERROR, "no lockres, but an mle with this node as master!\n");
1616 BUG();
1618 if (tmpmle->type == DLM_MLE_BLOCK)
1619 response = DLM_MASTER_RESP_NO;
1620 else if (tmpmle->type == DLM_MLE_MIGRATION) {
1621 mlog(0, "migration mle was found (%u->%u)\n",
1622 tmpmle->master, tmpmle->new_master);
1623 /* real master can respond on its own */
1624 response = DLM_MASTER_RESP_NO;
1625 } else
1626 response = DLM_MASTER_RESP_MAYBE;
1627 if (set_maybe)
1628 set_bit(request->node_idx, tmpmle->maybe_map);
1629 spin_unlock(&tmpmle->spinlock);
1631 spin_unlock(&dlm->master_lock);
1632 spin_unlock(&dlm->spinlock);
1634 if (found) {
1635 /* keep the mle attached to heartbeat events */
1636 dlm_put_mle(tmpmle);
1638 send_response:
1640 * __dlm_lookup_lockres() grabbed a reference to this lockres.
1641 * The reference is released by dlm_assert_master_worker() under
1642 * the call to dlm_dispatch_assert_master(). If
1643 * dlm_assert_master_worker() isn't called, we drop it here.
1645 if (dispatch_assert) {
1646 if (response != DLM_MASTER_RESP_YES)
1647 mlog(ML_ERROR, "invalid response %d\n", response);
1648 if (!res) {
1649 mlog(ML_ERROR, "bad lockres while trying to assert!\n");
1650 BUG();
1652 mlog(0, "%u is the owner of %.*s, cleaning everyone else\n",
1653 dlm->node_num, res->lockname.len, res->lockname.name);
1654 spin_lock(&res->spinlock);
1655 ret = dlm_dispatch_assert_master(dlm, res, 0, request->node_idx,
1656 DLM_ASSERT_MASTER_MLE_CLEANUP);
1657 if (ret < 0) {
1658 mlog(ML_ERROR, "failed to dispatch assert master work\n");
1659 response = DLM_MASTER_RESP_ERROR;
1660 dlm_lockres_put(res);
1661 } else
1662 __dlm_lockres_grab_inflight_worker(dlm, res);
1663 spin_unlock(&res->spinlock);
1664 } else {
1665 if (res)
1666 dlm_lockres_put(res);
1669 dlm_put(dlm);
1670 return response;
1674 * DLM_ASSERT_MASTER_MSG
1679 * NOTE: this can be used for debugging
1680 * can periodically run all locks owned by this node
1681 * and re-assert across the cluster...
1683 static int dlm_do_assert_master(struct dlm_ctxt *dlm,
1684 struct dlm_lock_resource *res,
1685 void *nodemap, u32 flags)
1687 struct dlm_assert_master assert;
1688 int to, tmpret;
1689 struct dlm_node_iter iter;
1690 int ret = 0;
1691 int reassert;
1692 const char *lockname = res->lockname.name;
1693 unsigned int namelen = res->lockname.len;
1695 BUG_ON(namelen > O2NM_MAX_NAME_LEN);
1697 spin_lock(&res->spinlock);
1698 res->state |= DLM_LOCK_RES_SETREF_INPROG;
1699 spin_unlock(&res->spinlock);
1701 again:
1702 reassert = 0;
1704 /* note that if this nodemap is empty, it returns 0 */
1705 dlm_node_iter_init(nodemap, &iter);
1706 while ((to = dlm_node_iter_next(&iter)) >= 0) {
1707 int r = 0;
1708 struct dlm_master_list_entry *mle = NULL;
1710 mlog(0, "sending assert master to %d (%.*s)\n", to,
1711 namelen, lockname);
1712 memset(&assert, 0, sizeof(assert));
1713 assert.node_idx = dlm->node_num;
1714 assert.namelen = namelen;
1715 memcpy(assert.name, lockname, namelen);
1716 assert.flags = cpu_to_be32(flags);
1718 tmpret = o2net_send_message(DLM_ASSERT_MASTER_MSG, dlm->key,
1719 &assert, sizeof(assert), to, &r);
1720 if (tmpret < 0) {
1721 mlog(ML_ERROR, "Error %d when sending message %u (key "
1722 "0x%x) to node %u\n", tmpret,
1723 DLM_ASSERT_MASTER_MSG, dlm->key, to);
1724 if (!dlm_is_host_down(tmpret)) {
1725 mlog(ML_ERROR, "unhandled error=%d!\n", tmpret);
1726 BUG();
1728 /* a node died. finish out the rest of the nodes. */
1729 mlog(0, "link to %d went down!\n", to);
1730 /* any nonzero status return will do */
1731 ret = tmpret;
1732 r = 0;
1733 } else if (r < 0) {
1734 /* ok, something horribly messed. kill thyself. */
1735 mlog(ML_ERROR,"during assert master of %.*s to %u, "
1736 "got %d.\n", namelen, lockname, to, r);
1737 spin_lock(&dlm->spinlock);
1738 spin_lock(&dlm->master_lock);
1739 if (dlm_find_mle(dlm, &mle, (char *)lockname,
1740 namelen)) {
1741 dlm_print_one_mle(mle);
1742 __dlm_put_mle(mle);
1744 spin_unlock(&dlm->master_lock);
1745 spin_unlock(&dlm->spinlock);
1746 BUG();
1749 if (r & DLM_ASSERT_RESPONSE_REASSERT &&
1750 !(r & DLM_ASSERT_RESPONSE_MASTERY_REF)) {
1751 mlog(ML_ERROR, "%.*s: very strange, "
1752 "master MLE but no lockres on %u\n",
1753 namelen, lockname, to);
1756 if (r & DLM_ASSERT_RESPONSE_REASSERT) {
1757 mlog(0, "%.*s: node %u create mles on other "
1758 "nodes and requests a re-assert\n",
1759 namelen, lockname, to);
1760 reassert = 1;
1762 if (r & DLM_ASSERT_RESPONSE_MASTERY_REF) {
1763 mlog(0, "%.*s: node %u has a reference to this "
1764 "lockres, set the bit in the refmap\n",
1765 namelen, lockname, to);
1766 spin_lock(&res->spinlock);
1767 dlm_lockres_set_refmap_bit(dlm, res, to);
1768 spin_unlock(&res->spinlock);
1772 if (reassert)
1773 goto again;
1775 spin_lock(&res->spinlock);
1776 res->state &= ~DLM_LOCK_RES_SETREF_INPROG;
1777 spin_unlock(&res->spinlock);
1778 wake_up(&res->wq);
1780 return ret;
1784 * locks that can be taken here:
1785 * dlm->spinlock
1786 * res->spinlock
1787 * mle->spinlock
1788 * dlm->master_list
1790 * if possible, TRIM THIS DOWN!!!
1792 int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data,
1793 void **ret_data)
1795 struct dlm_ctxt *dlm = data;
1796 struct dlm_master_list_entry *mle = NULL;
1797 struct dlm_assert_master *assert = (struct dlm_assert_master *)msg->buf;
1798 struct dlm_lock_resource *res = NULL;
1799 char *name;
1800 unsigned int namelen, hash;
1801 u32 flags;
1802 int master_request = 0, have_lockres_ref = 0;
1803 int ret = 0;
1805 if (!dlm_grab(dlm))
1806 return 0;
1808 name = assert->name;
1809 namelen = assert->namelen;
1810 hash = dlm_lockid_hash(name, namelen);
1811 flags = be32_to_cpu(assert->flags);
1813 if (namelen > DLM_LOCKID_NAME_MAX) {
1814 mlog(ML_ERROR, "Invalid name length!");
1815 goto done;
1818 spin_lock(&dlm->spinlock);
1820 if (flags)
1821 mlog(0, "assert_master with flags: %u\n", flags);
1823 /* find the MLE */
1824 spin_lock(&dlm->master_lock);
1825 if (!dlm_find_mle(dlm, &mle, name, namelen)) {
1826 /* not an error, could be master just re-asserting */
1827 mlog(0, "just got an assert_master from %u, but no "
1828 "MLE for it! (%.*s)\n", assert->node_idx,
1829 namelen, name);
1830 } else {
1831 int bit = find_next_bit (mle->maybe_map, O2NM_MAX_NODES, 0);
1832 if (bit >= O2NM_MAX_NODES) {
1833 /* not necessarily an error, though less likely.
1834 * could be master just re-asserting. */
1835 mlog(0, "no bits set in the maybe_map, but %u "
1836 "is asserting! (%.*s)\n", assert->node_idx,
1837 namelen, name);
1838 } else if (bit != assert->node_idx) {
1839 if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) {
1840 mlog(0, "master %u was found, %u should "
1841 "back off\n", assert->node_idx, bit);
1842 } else {
1843 /* with the fix for bug 569, a higher node
1844 * number winning the mastery will respond
1845 * YES to mastery requests, but this node
1846 * had no way of knowing. let it pass. */
1847 mlog(0, "%u is the lowest node, "
1848 "%u is asserting. (%.*s) %u must "
1849 "have begun after %u won.\n", bit,
1850 assert->node_idx, namelen, name, bit,
1851 assert->node_idx);
1854 if (mle->type == DLM_MLE_MIGRATION) {
1855 if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) {
1856 mlog(0, "%s:%.*s: got cleanup assert"
1857 " from %u for migration\n",
1858 dlm->name, namelen, name,
1859 assert->node_idx);
1860 } else if (!(flags & DLM_ASSERT_MASTER_FINISH_MIGRATION)) {
1861 mlog(0, "%s:%.*s: got unrelated assert"
1862 " from %u for migration, ignoring\n",
1863 dlm->name, namelen, name,
1864 assert->node_idx);
1865 __dlm_put_mle(mle);
1866 spin_unlock(&dlm->master_lock);
1867 spin_unlock(&dlm->spinlock);
1868 goto done;
1872 spin_unlock(&dlm->master_lock);
1874 /* ok everything checks out with the MLE
1875 * now check to see if there is a lockres */
1876 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
1877 if (res) {
1878 spin_lock(&res->spinlock);
1879 if (res->state & DLM_LOCK_RES_RECOVERING) {
1880 mlog(ML_ERROR, "%u asserting but %.*s is "
1881 "RECOVERING!\n", assert->node_idx, namelen, name);
1882 goto kill;
1884 if (!mle) {
1885 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN &&
1886 res->owner != assert->node_idx) {
1887 mlog(ML_ERROR, "DIE! Mastery assert from %u, "
1888 "but current owner is %u! (%.*s)\n",
1889 assert->node_idx, res->owner, namelen,
1890 name);
1891 __dlm_print_one_lock_resource(res);
1892 BUG();
1894 } else if (mle->type != DLM_MLE_MIGRATION) {
1895 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
1896 /* owner is just re-asserting */
1897 if (res->owner == assert->node_idx) {
1898 mlog(0, "owner %u re-asserting on "
1899 "lock %.*s\n", assert->node_idx,
1900 namelen, name);
1901 goto ok;
1903 mlog(ML_ERROR, "got assert_master from "
1904 "node %u, but %u is the owner! "
1905 "(%.*s)\n", assert->node_idx,
1906 res->owner, namelen, name);
1907 goto kill;
1909 if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) {
1910 mlog(ML_ERROR, "got assert from %u, but lock "
1911 "with no owner should be "
1912 "in-progress! (%.*s)\n",
1913 assert->node_idx,
1914 namelen, name);
1915 goto kill;
1917 } else /* mle->type == DLM_MLE_MIGRATION */ {
1918 /* should only be getting an assert from new master */
1919 if (assert->node_idx != mle->new_master) {
1920 mlog(ML_ERROR, "got assert from %u, but "
1921 "new master is %u, and old master "
1922 "was %u (%.*s)\n",
1923 assert->node_idx, mle->new_master,
1924 mle->master, namelen, name);
1925 goto kill;
1930 spin_unlock(&res->spinlock);
1933 // mlog(0, "woo! got an assert_master from node %u!\n",
1934 // assert->node_idx);
1935 if (mle) {
1936 int extra_ref = 0;
1937 int nn = -1;
1938 int rr, err = 0;
1940 spin_lock(&mle->spinlock);
1941 if (mle->type == DLM_MLE_BLOCK || mle->type == DLM_MLE_MIGRATION)
1942 extra_ref = 1;
1943 else {
1944 /* MASTER mle: if any bits set in the response map
1945 * then the calling node needs to re-assert to clear
1946 * up nodes that this node contacted */
1947 while ((nn = find_next_bit (mle->response_map, O2NM_MAX_NODES,
1948 nn+1)) < O2NM_MAX_NODES) {
1949 if (nn != dlm->node_num && nn != assert->node_idx) {
1950 master_request = 1;
1951 break;
1955 mle->master = assert->node_idx;
1956 atomic_set(&mle->woken, 1);
1957 wake_up(&mle->wq);
1958 spin_unlock(&mle->spinlock);
1960 if (res) {
1961 int wake = 0;
1962 spin_lock(&res->spinlock);
1963 if (mle->type == DLM_MLE_MIGRATION) {
1964 mlog(0, "finishing off migration of lockres %.*s, "
1965 "from %u to %u\n",
1966 res->lockname.len, res->lockname.name,
1967 dlm->node_num, mle->new_master);
1968 res->state &= ~DLM_LOCK_RES_MIGRATING;
1969 wake = 1;
1970 dlm_change_lockres_owner(dlm, res, mle->new_master);
1971 BUG_ON(res->state & DLM_LOCK_RES_DIRTY);
1972 } else {
1973 dlm_change_lockres_owner(dlm, res, mle->master);
1975 spin_unlock(&res->spinlock);
1976 have_lockres_ref = 1;
1977 if (wake)
1978 wake_up(&res->wq);
1981 /* master is known, detach if not already detached.
1982 * ensures that only one assert_master call will happen
1983 * on this mle. */
1984 spin_lock(&dlm->master_lock);
1986 rr = atomic_read(&mle->mle_refs.refcount);
1987 if (mle->inuse > 0) {
1988 if (extra_ref && rr < 3)
1989 err = 1;
1990 else if (!extra_ref && rr < 2)
1991 err = 1;
1992 } else {
1993 if (extra_ref && rr < 2)
1994 err = 1;
1995 else if (!extra_ref && rr < 1)
1996 err = 1;
1998 if (err) {
1999 mlog(ML_ERROR, "%s:%.*s: got assert master from %u "
2000 "that will mess up this node, refs=%d, extra=%d, "
2001 "inuse=%d\n", dlm->name, namelen, name,
2002 assert->node_idx, rr, extra_ref, mle->inuse);
2003 dlm_print_one_mle(mle);
2005 __dlm_unlink_mle(dlm, mle);
2006 __dlm_mle_detach_hb_events(dlm, mle);
2007 __dlm_put_mle(mle);
2008 if (extra_ref) {
2009 /* the assert master message now balances the extra
2010 * ref given by the master / migration request message.
2011 * if this is the last put, it will be removed
2012 * from the list. */
2013 __dlm_put_mle(mle);
2015 spin_unlock(&dlm->master_lock);
2016 } else if (res) {
2017 if (res->owner != assert->node_idx) {
2018 mlog(0, "assert_master from %u, but current "
2019 "owner is %u (%.*s), no mle\n", assert->node_idx,
2020 res->owner, namelen, name);
2023 spin_unlock(&dlm->spinlock);
2025 done:
2026 ret = 0;
2027 if (res) {
2028 spin_lock(&res->spinlock);
2029 res->state |= DLM_LOCK_RES_SETREF_INPROG;
2030 spin_unlock(&res->spinlock);
2031 *ret_data = (void *)res;
2033 dlm_put(dlm);
2034 if (master_request) {
2035 mlog(0, "need to tell master to reassert\n");
2036 /* positive. negative would shoot down the node. */
2037 ret |= DLM_ASSERT_RESPONSE_REASSERT;
2038 if (!have_lockres_ref) {
2039 mlog(ML_ERROR, "strange, got assert from %u, MASTER "
2040 "mle present here for %s:%.*s, but no lockres!\n",
2041 assert->node_idx, dlm->name, namelen, name);
2044 if (have_lockres_ref) {
2045 /* let the master know we have a reference to the lockres */
2046 ret |= DLM_ASSERT_RESPONSE_MASTERY_REF;
2047 mlog(0, "%s:%.*s: got assert from %u, need a ref\n",
2048 dlm->name, namelen, name, assert->node_idx);
2050 return ret;
2052 kill:
2053 /* kill the caller! */
2054 mlog(ML_ERROR, "Bad message received from another node. Dumping state "
2055 "and killing the other node now! This node is OK and can continue.\n");
2056 __dlm_print_one_lock_resource(res);
2057 spin_unlock(&res->spinlock);
2058 spin_lock(&dlm->master_lock);
2059 if (mle)
2060 __dlm_put_mle(mle);
2061 spin_unlock(&dlm->master_lock);
2062 spin_unlock(&dlm->spinlock);
2063 *ret_data = (void *)res;
2064 dlm_put(dlm);
2065 return -EINVAL;
2068 void dlm_assert_master_post_handler(int status, void *data, void *ret_data)
2070 struct dlm_lock_resource *res = (struct dlm_lock_resource *)ret_data;
2072 if (ret_data) {
2073 spin_lock(&res->spinlock);
2074 res->state &= ~DLM_LOCK_RES_SETREF_INPROG;
2075 spin_unlock(&res->spinlock);
2076 wake_up(&res->wq);
2077 dlm_lockres_put(res);
2079 return;
2082 int dlm_dispatch_assert_master(struct dlm_ctxt *dlm,
2083 struct dlm_lock_resource *res,
2084 int ignore_higher, u8 request_from, u32 flags)
2086 struct dlm_work_item *item;
2087 item = kzalloc(sizeof(*item), GFP_ATOMIC);
2088 if (!item)
2089 return -ENOMEM;
2092 /* queue up work for dlm_assert_master_worker */
2093 dlm_grab(dlm); /* get an extra ref for the work item */
2094 dlm_init_work_item(dlm, item, dlm_assert_master_worker, NULL);
2095 item->u.am.lockres = res; /* already have a ref */
2096 /* can optionally ignore node numbers higher than this node */
2097 item->u.am.ignore_higher = ignore_higher;
2098 item->u.am.request_from = request_from;
2099 item->u.am.flags = flags;
2101 if (ignore_higher)
2102 mlog(0, "IGNORE HIGHER: %.*s\n", res->lockname.len,
2103 res->lockname.name);
2105 spin_lock(&dlm->work_lock);
2106 list_add_tail(&item->list, &dlm->work_list);
2107 spin_unlock(&dlm->work_lock);
2109 queue_work(dlm->dlm_worker, &dlm->dispatched_work);
2110 return 0;
2113 static void dlm_assert_master_worker(struct dlm_work_item *item, void *data)
2115 struct dlm_ctxt *dlm = data;
2116 int ret = 0;
2117 struct dlm_lock_resource *res;
2118 unsigned long nodemap[BITS_TO_LONGS(O2NM_MAX_NODES)];
2119 int ignore_higher;
2120 int bit;
2121 u8 request_from;
2122 u32 flags;
2124 dlm = item->dlm;
2125 res = item->u.am.lockres;
2126 ignore_higher = item->u.am.ignore_higher;
2127 request_from = item->u.am.request_from;
2128 flags = item->u.am.flags;
2130 spin_lock(&dlm->spinlock);
2131 memcpy(nodemap, dlm->domain_map, sizeof(nodemap));
2132 spin_unlock(&dlm->spinlock);
2134 clear_bit(dlm->node_num, nodemap);
2135 if (ignore_higher) {
2136 /* if is this just to clear up mles for nodes below
2137 * this node, do not send the message to the original
2138 * caller or any node number higher than this */
2139 clear_bit(request_from, nodemap);
2140 bit = dlm->node_num;
2141 while (1) {
2142 bit = find_next_bit(nodemap, O2NM_MAX_NODES,
2143 bit+1);
2144 if (bit >= O2NM_MAX_NODES)
2145 break;
2146 clear_bit(bit, nodemap);
2151 * If we're migrating this lock to someone else, we are no
2152 * longer allowed to assert out own mastery. OTOH, we need to
2153 * prevent migration from starting while we're still asserting
2154 * our dominance. The reserved ast delays migration.
2156 spin_lock(&res->spinlock);
2157 if (res->state & DLM_LOCK_RES_MIGRATING) {
2158 mlog(0, "Someone asked us to assert mastery, but we're "
2159 "in the middle of migration. Skipping assert, "
2160 "the new master will handle that.\n");
2161 spin_unlock(&res->spinlock);
2162 goto put;
2163 } else
2164 __dlm_lockres_reserve_ast(res);
2165 spin_unlock(&res->spinlock);
2167 /* this call now finishes out the nodemap
2168 * even if one or more nodes die */
2169 mlog(0, "worker about to master %.*s here, this=%u\n",
2170 res->lockname.len, res->lockname.name, dlm->node_num);
2171 ret = dlm_do_assert_master(dlm, res, nodemap, flags);
2172 if (ret < 0) {
2173 /* no need to restart, we are done */
2174 if (!dlm_is_host_down(ret))
2175 mlog_errno(ret);
2178 /* Ok, we've asserted ourselves. Let's let migration start. */
2179 dlm_lockres_release_ast(dlm, res);
2181 put:
2182 dlm_lockres_drop_inflight_worker(dlm, res);
2184 dlm_lockres_put(res);
2186 mlog(0, "finished with dlm_assert_master_worker\n");
2189 /* SPECIAL CASE for the $RECOVERY lock used by the recovery thread.
2190 * We cannot wait for node recovery to complete to begin mastering this
2191 * lockres because this lockres is used to kick off recovery! ;-)
2192 * So, do a pre-check on all living nodes to see if any of those nodes
2193 * think that $RECOVERY is currently mastered by a dead node. If so,
2194 * we wait a short time to allow that node to get notified by its own
2195 * heartbeat stack, then check again. All $RECOVERY lock resources
2196 * mastered by dead nodes are purged when the hearbeat callback is
2197 * fired, so we can know for sure that it is safe to continue once
2198 * the node returns a live node or no node. */
2199 static int dlm_pre_master_reco_lockres(struct dlm_ctxt *dlm,
2200 struct dlm_lock_resource *res)
2202 struct dlm_node_iter iter;
2203 int nodenum;
2204 int ret = 0;
2205 u8 master = DLM_LOCK_RES_OWNER_UNKNOWN;
2207 spin_lock(&dlm->spinlock);
2208 dlm_node_iter_init(dlm->domain_map, &iter);
2209 spin_unlock(&dlm->spinlock);
2211 while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2212 /* do not send to self */
2213 if (nodenum == dlm->node_num)
2214 continue;
2215 ret = dlm_do_master_requery(dlm, res, nodenum, &master);
2216 if (ret < 0) {
2217 mlog_errno(ret);
2218 if (!dlm_is_host_down(ret))
2219 BUG();
2220 /* host is down, so answer for that node would be
2221 * DLM_LOCK_RES_OWNER_UNKNOWN. continue. */
2222 ret = 0;
2225 if (master != DLM_LOCK_RES_OWNER_UNKNOWN) {
2226 /* check to see if this master is in the recovery map */
2227 spin_lock(&dlm->spinlock);
2228 if (test_bit(master, dlm->recovery_map)) {
2229 mlog(ML_NOTICE, "%s: node %u has not seen "
2230 "node %u go down yet, and thinks the "
2231 "dead node is mastering the recovery "
2232 "lock. must wait.\n", dlm->name,
2233 nodenum, master);
2234 ret = -EAGAIN;
2236 spin_unlock(&dlm->spinlock);
2237 mlog(0, "%s: reco lock master is %u\n", dlm->name,
2238 master);
2239 break;
2242 return ret;
2246 * DLM_DEREF_LOCKRES_MSG
2249 int dlm_drop_lockres_ref(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
2251 struct dlm_deref_lockres deref;
2252 int ret = 0, r;
2253 const char *lockname;
2254 unsigned int namelen;
2256 lockname = res->lockname.name;
2257 namelen = res->lockname.len;
2258 BUG_ON(namelen > O2NM_MAX_NAME_LEN);
2260 memset(&deref, 0, sizeof(deref));
2261 deref.node_idx = dlm->node_num;
2262 deref.namelen = namelen;
2263 memcpy(deref.name, lockname, namelen);
2265 ret = o2net_send_message(DLM_DEREF_LOCKRES_MSG, dlm->key,
2266 &deref, sizeof(deref), res->owner, &r);
2267 if (ret < 0)
2268 mlog(ML_ERROR, "%s: res %.*s, error %d send DEREF to node %u\n",
2269 dlm->name, namelen, lockname, ret, res->owner);
2270 else if (r < 0) {
2271 /* BAD. other node says I did not have a ref. */
2272 mlog(ML_ERROR, "%s: res %.*s, DEREF to node %u got %d\n",
2273 dlm->name, namelen, lockname, res->owner, r);
2274 dlm_print_one_lock_resource(res);
2275 BUG();
2277 return ret;
2280 int dlm_deref_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
2281 void **ret_data)
2283 struct dlm_ctxt *dlm = data;
2284 struct dlm_deref_lockres *deref = (struct dlm_deref_lockres *)msg->buf;
2285 struct dlm_lock_resource *res = NULL;
2286 char *name;
2287 unsigned int namelen;
2288 int ret = -EINVAL;
2289 u8 node;
2290 unsigned int hash;
2291 struct dlm_work_item *item;
2292 int cleared = 0;
2293 int dispatch = 0;
2295 if (!dlm_grab(dlm))
2296 return 0;
2298 name = deref->name;
2299 namelen = deref->namelen;
2300 node = deref->node_idx;
2302 if (namelen > DLM_LOCKID_NAME_MAX) {
2303 mlog(ML_ERROR, "Invalid name length!");
2304 goto done;
2306 if (deref->node_idx >= O2NM_MAX_NODES) {
2307 mlog(ML_ERROR, "Invalid node number: %u\n", node);
2308 goto done;
2311 hash = dlm_lockid_hash(name, namelen);
2313 spin_lock(&dlm->spinlock);
2314 res = __dlm_lookup_lockres_full(dlm, name, namelen, hash);
2315 if (!res) {
2316 spin_unlock(&dlm->spinlock);
2317 mlog(ML_ERROR, "%s:%.*s: bad lockres name\n",
2318 dlm->name, namelen, name);
2319 goto done;
2321 spin_unlock(&dlm->spinlock);
2323 spin_lock(&res->spinlock);
2324 if (res->state & DLM_LOCK_RES_SETREF_INPROG)
2325 dispatch = 1;
2326 else {
2327 BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF);
2328 if (test_bit(node, res->refmap)) {
2329 dlm_lockres_clear_refmap_bit(dlm, res, node);
2330 cleared = 1;
2333 spin_unlock(&res->spinlock);
2335 if (!dispatch) {
2336 if (cleared)
2337 dlm_lockres_calc_usage(dlm, res);
2338 else {
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);
2344 ret = 0;
2345 goto done;
2348 item = kzalloc(sizeof(*item), GFP_NOFS);
2349 if (!item) {
2350 ret = -ENOMEM;
2351 mlog_errno(ret);
2352 goto done;
2355 dlm_init_work_item(dlm, item, dlm_deref_lockres_worker, NULL);
2356 item->u.dl.deref_res = res;
2357 item->u.dl.deref_node = node;
2359 spin_lock(&dlm->work_lock);
2360 list_add_tail(&item->list, &dlm->work_list);
2361 spin_unlock(&dlm->work_lock);
2363 queue_work(dlm->dlm_worker, &dlm->dispatched_work);
2364 return 0;
2366 done:
2367 if (res)
2368 dlm_lockres_put(res);
2369 dlm_put(dlm);
2371 return ret;
2374 static void dlm_deref_lockres_worker(struct dlm_work_item *item, void *data)
2376 struct dlm_ctxt *dlm;
2377 struct dlm_lock_resource *res;
2378 u8 node;
2379 u8 cleared = 0;
2381 dlm = item->dlm;
2382 res = item->u.dl.deref_res;
2383 node = item->u.dl.deref_node;
2385 spin_lock(&res->spinlock);
2386 BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF);
2387 if (test_bit(node, res->refmap)) {
2388 __dlm_wait_on_lockres_flags(res, DLM_LOCK_RES_SETREF_INPROG);
2389 dlm_lockres_clear_refmap_bit(dlm, res, node);
2390 cleared = 1;
2392 spin_unlock(&res->spinlock);
2394 if (cleared) {
2395 mlog(0, "%s:%.*s node %u ref dropped in dispatch\n",
2396 dlm->name, res->lockname.len, res->lockname.name, node);
2397 dlm_lockres_calc_usage(dlm, res);
2398 } else {
2399 mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref "
2400 "but it is already dropped!\n", dlm->name,
2401 res->lockname.len, res->lockname.name, node);
2402 dlm_print_one_lock_resource(res);
2405 dlm_lockres_put(res);
2409 * A migrateable resource is one that is :
2410 * 1. locally mastered, and,
2411 * 2. zero local locks, and,
2412 * 3. one or more non-local locks, or, one or more references
2413 * Returns 1 if yes, 0 if not.
2415 static int dlm_is_lockres_migrateable(struct dlm_ctxt *dlm,
2416 struct dlm_lock_resource *res)
2418 enum dlm_lockres_list idx;
2419 int nonlocal = 0, node_ref;
2420 struct list_head *queue;
2421 struct dlm_lock *lock;
2422 u64 cookie;
2424 assert_spin_locked(&res->spinlock);
2426 /* delay migration when the lockres is in MIGRATING state */
2427 if (res->state & DLM_LOCK_RES_MIGRATING)
2428 return 0;
2430 /* delay migration when the lockres is in RECOCERING state */
2431 if (res->state & DLM_LOCK_RES_RECOVERING)
2432 return 0;
2434 if (res->owner != dlm->node_num)
2435 return 0;
2437 for (idx = DLM_GRANTED_LIST; idx <= DLM_BLOCKED_LIST; idx++) {
2438 queue = dlm_list_idx_to_ptr(res, idx);
2439 list_for_each_entry(lock, queue, list) {
2440 if (lock->ml.node != dlm->node_num) {
2441 nonlocal++;
2442 continue;
2444 cookie = be64_to_cpu(lock->ml.cookie);
2445 mlog(0, "%s: Not migrateable res %.*s, lock %u:%llu on "
2446 "%s list\n", dlm->name, res->lockname.len,
2447 res->lockname.name,
2448 dlm_get_lock_cookie_node(cookie),
2449 dlm_get_lock_cookie_seq(cookie),
2450 dlm_list_in_text(idx));
2451 return 0;
2455 if (!nonlocal) {
2456 node_ref = find_next_bit(res->refmap, O2NM_MAX_NODES, 0);
2457 if (node_ref >= O2NM_MAX_NODES)
2458 return 0;
2461 mlog(0, "%s: res %.*s, Migrateable\n", dlm->name, res->lockname.len,
2462 res->lockname.name);
2464 return 1;
2468 * DLM_MIGRATE_LOCKRES
2472 static int dlm_migrate_lockres(struct dlm_ctxt *dlm,
2473 struct dlm_lock_resource *res, u8 target)
2475 struct dlm_master_list_entry *mle = NULL;
2476 struct dlm_master_list_entry *oldmle = NULL;
2477 struct dlm_migratable_lockres *mres = NULL;
2478 int ret = 0;
2479 const char *name;
2480 unsigned int namelen;
2481 int mle_added = 0;
2482 int wake = 0;
2484 if (!dlm_grab(dlm))
2485 return -EINVAL;
2487 BUG_ON(target == O2NM_MAX_NODES);
2489 name = res->lockname.name;
2490 namelen = res->lockname.len;
2492 mlog(0, "%s: Migrating %.*s to node %u\n", dlm->name, namelen, name,
2493 target);
2495 /* preallocate up front. if this fails, abort */
2496 ret = -ENOMEM;
2497 mres = (struct dlm_migratable_lockres *) __get_free_page(GFP_NOFS);
2498 if (!mres) {
2499 mlog_errno(ret);
2500 goto leave;
2503 mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
2504 if (!mle) {
2505 mlog_errno(ret);
2506 goto leave;
2508 ret = 0;
2511 * clear any existing master requests and
2512 * add the migration mle to the list
2514 spin_lock(&dlm->spinlock);
2515 spin_lock(&dlm->master_lock);
2516 ret = dlm_add_migration_mle(dlm, res, mle, &oldmle, name,
2517 namelen, target, dlm->node_num);
2518 spin_unlock(&dlm->master_lock);
2519 spin_unlock(&dlm->spinlock);
2521 if (ret == -EEXIST) {
2522 mlog(0, "another process is already migrating it\n");
2523 goto fail;
2525 mle_added = 1;
2528 * set the MIGRATING flag and flush asts
2529 * if we fail after this we need to re-dirty the lockres
2531 if (dlm_mark_lockres_migrating(dlm, res, target) < 0) {
2532 mlog(ML_ERROR, "tried to migrate %.*s to %u, but "
2533 "the target went down.\n", res->lockname.len,
2534 res->lockname.name, target);
2535 spin_lock(&res->spinlock);
2536 res->state &= ~DLM_LOCK_RES_MIGRATING;
2537 wake = 1;
2538 spin_unlock(&res->spinlock);
2539 ret = -EINVAL;
2542 fail:
2543 if (oldmle) {
2544 /* master is known, detach if not already detached */
2545 dlm_mle_detach_hb_events(dlm, oldmle);
2546 dlm_put_mle(oldmle);
2549 if (ret < 0) {
2550 if (mle_added) {
2551 dlm_mle_detach_hb_events(dlm, mle);
2552 dlm_put_mle(mle);
2553 } else if (mle) {
2554 kmem_cache_free(dlm_mle_cache, mle);
2555 mle = NULL;
2557 goto leave;
2561 * at this point, we have a migration target, an mle
2562 * in the master list, and the MIGRATING flag set on
2563 * the lockres
2566 /* now that remote nodes are spinning on the MIGRATING flag,
2567 * ensure that all assert_master work is flushed. */
2568 flush_workqueue(dlm->dlm_worker);
2570 /* get an extra reference on the mle.
2571 * otherwise the assert_master from the new
2572 * master will destroy this.
2573 * also, make sure that all callers of dlm_get_mle
2574 * take both dlm->spinlock and dlm->master_lock */
2575 spin_lock(&dlm->spinlock);
2576 spin_lock(&dlm->master_lock);
2577 dlm_get_mle_inuse(mle);
2578 spin_unlock(&dlm->master_lock);
2579 spin_unlock(&dlm->spinlock);
2581 /* notify new node and send all lock state */
2582 /* call send_one_lockres with migration flag.
2583 * this serves as notice to the target node that a
2584 * migration is starting. */
2585 ret = dlm_send_one_lockres(dlm, res, mres, target,
2586 DLM_MRES_MIGRATION);
2588 if (ret < 0) {
2589 mlog(0, "migration to node %u failed with %d\n",
2590 target, ret);
2591 /* migration failed, detach and clean up mle */
2592 dlm_mle_detach_hb_events(dlm, mle);
2593 dlm_put_mle(mle);
2594 dlm_put_mle_inuse(mle);
2595 spin_lock(&res->spinlock);
2596 res->state &= ~DLM_LOCK_RES_MIGRATING;
2597 wake = 1;
2598 spin_unlock(&res->spinlock);
2599 if (dlm_is_host_down(ret))
2600 dlm_wait_for_node_death(dlm, target,
2601 DLM_NODE_DEATH_WAIT_MAX);
2602 goto leave;
2605 /* at this point, the target sends a message to all nodes,
2606 * (using dlm_do_migrate_request). this node is skipped since
2607 * we had to put an mle in the list to begin the process. this
2608 * node now waits for target to do an assert master. this node
2609 * will be the last one notified, ensuring that the migration
2610 * is complete everywhere. if the target dies while this is
2611 * going on, some nodes could potentially see the target as the
2612 * master, so it is important that my recovery finds the migration
2613 * mle and sets the master to UNKNOWN. */
2616 /* wait for new node to assert master */
2617 while (1) {
2618 ret = wait_event_interruptible_timeout(mle->wq,
2619 (atomic_read(&mle->woken) == 1),
2620 msecs_to_jiffies(5000));
2622 if (ret >= 0) {
2623 if (atomic_read(&mle->woken) == 1 ||
2624 res->owner == target)
2625 break;
2627 mlog(0, "%s:%.*s: timed out during migration\n",
2628 dlm->name, res->lockname.len, res->lockname.name);
2629 /* avoid hang during shutdown when migrating lockres
2630 * to a node which also goes down */
2631 if (dlm_is_node_dead(dlm, target)) {
2632 mlog(0, "%s:%.*s: expected migration "
2633 "target %u is no longer up, restarting\n",
2634 dlm->name, res->lockname.len,
2635 res->lockname.name, target);
2636 ret = -EINVAL;
2637 /* migration failed, detach and clean up mle */
2638 dlm_mle_detach_hb_events(dlm, mle);
2639 dlm_put_mle(mle);
2640 dlm_put_mle_inuse(mle);
2641 spin_lock(&res->spinlock);
2642 res->state &= ~DLM_LOCK_RES_MIGRATING;
2643 wake = 1;
2644 spin_unlock(&res->spinlock);
2645 goto leave;
2647 } else
2648 mlog(0, "%s:%.*s: caught signal during migration\n",
2649 dlm->name, res->lockname.len, res->lockname.name);
2652 /* all done, set the owner, clear the flag */
2653 spin_lock(&res->spinlock);
2654 dlm_set_lockres_owner(dlm, res, target);
2655 res->state &= ~DLM_LOCK_RES_MIGRATING;
2656 dlm_remove_nonlocal_locks(dlm, res);
2657 spin_unlock(&res->spinlock);
2658 wake_up(&res->wq);
2660 /* master is known, detach if not already detached */
2661 dlm_mle_detach_hb_events(dlm, mle);
2662 dlm_put_mle_inuse(mle);
2663 ret = 0;
2665 dlm_lockres_calc_usage(dlm, res);
2667 leave:
2668 /* re-dirty the lockres if we failed */
2669 if (ret < 0)
2670 dlm_kick_thread(dlm, res);
2672 /* wake up waiters if the MIGRATING flag got set
2673 * but migration failed */
2674 if (wake)
2675 wake_up(&res->wq);
2677 if (mres)
2678 free_page((unsigned long)mres);
2680 dlm_put(dlm);
2682 mlog(0, "%s: Migrating %.*s to %u, returns %d\n", dlm->name, namelen,
2683 name, target, ret);
2684 return ret;
2687 #define DLM_MIGRATION_RETRY_MS 100
2690 * Should be called only after beginning the domain leave process.
2691 * There should not be any remaining locks on nonlocal lock resources,
2692 * and there should be no local locks left on locally mastered resources.
2694 * Called with the dlm spinlock held, may drop it to do migration, but
2695 * will re-acquire before exit.
2697 * Returns: 1 if dlm->spinlock was dropped/retaken, 0 if never dropped
2699 int dlm_empty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
2701 int ret;
2702 int lock_dropped = 0;
2703 u8 target = O2NM_MAX_NODES;
2705 assert_spin_locked(&dlm->spinlock);
2707 spin_lock(&res->spinlock);
2708 if (dlm_is_lockres_migrateable(dlm, res))
2709 target = dlm_pick_migration_target(dlm, res);
2710 spin_unlock(&res->spinlock);
2712 if (target == O2NM_MAX_NODES)
2713 goto leave;
2715 /* Wheee! Migrate lockres here! Will sleep so drop spinlock. */
2716 spin_unlock(&dlm->spinlock);
2717 lock_dropped = 1;
2718 ret = dlm_migrate_lockres(dlm, res, target);
2719 if (ret)
2720 mlog(0, "%s: res %.*s, Migrate to node %u failed with %d\n",
2721 dlm->name, res->lockname.len, res->lockname.name,
2722 target, ret);
2723 spin_lock(&dlm->spinlock);
2724 leave:
2725 return lock_dropped;
2728 int dlm_lock_basts_flushed(struct dlm_ctxt *dlm, struct dlm_lock *lock)
2730 int ret;
2731 spin_lock(&dlm->ast_lock);
2732 spin_lock(&lock->spinlock);
2733 ret = (list_empty(&lock->bast_list) && !lock->bast_pending);
2734 spin_unlock(&lock->spinlock);
2735 spin_unlock(&dlm->ast_lock);
2736 return ret;
2739 static int dlm_migration_can_proceed(struct dlm_ctxt *dlm,
2740 struct dlm_lock_resource *res,
2741 u8 mig_target)
2743 int can_proceed;
2744 spin_lock(&res->spinlock);
2745 can_proceed = !!(res->state & DLM_LOCK_RES_MIGRATING);
2746 spin_unlock(&res->spinlock);
2748 /* target has died, so make the caller break out of the
2749 * wait_event, but caller must recheck the domain_map */
2750 spin_lock(&dlm->spinlock);
2751 if (!test_bit(mig_target, dlm->domain_map))
2752 can_proceed = 1;
2753 spin_unlock(&dlm->spinlock);
2754 return can_proceed;
2757 static int dlm_lockres_is_dirty(struct dlm_ctxt *dlm,
2758 struct dlm_lock_resource *res)
2760 int ret;
2761 spin_lock(&res->spinlock);
2762 ret = !!(res->state & DLM_LOCK_RES_DIRTY);
2763 spin_unlock(&res->spinlock);
2764 return ret;
2768 static int dlm_mark_lockres_migrating(struct dlm_ctxt *dlm,
2769 struct dlm_lock_resource *res,
2770 u8 target)
2772 int ret = 0;
2774 mlog(0, "dlm_mark_lockres_migrating: %.*s, from %u to %u\n",
2775 res->lockname.len, res->lockname.name, dlm->node_num,
2776 target);
2777 /* need to set MIGRATING flag on lockres. this is done by
2778 * ensuring that all asts have been flushed for this lockres. */
2779 spin_lock(&res->spinlock);
2780 BUG_ON(res->migration_pending);
2781 res->migration_pending = 1;
2782 /* strategy is to reserve an extra ast then release
2783 * it below, letting the release do all of the work */
2784 __dlm_lockres_reserve_ast(res);
2785 spin_unlock(&res->spinlock);
2787 /* now flush all the pending asts */
2788 dlm_kick_thread(dlm, res);
2789 /* before waiting on DIRTY, block processes which may
2790 * try to dirty the lockres before MIGRATING is set */
2791 spin_lock(&res->spinlock);
2792 BUG_ON(res->state & DLM_LOCK_RES_BLOCK_DIRTY);
2793 res->state |= DLM_LOCK_RES_BLOCK_DIRTY;
2794 spin_unlock(&res->spinlock);
2795 /* now wait on any pending asts and the DIRTY state */
2796 wait_event(dlm->ast_wq, !dlm_lockres_is_dirty(dlm, res));
2797 dlm_lockres_release_ast(dlm, res);
2799 mlog(0, "about to wait on migration_wq, dirty=%s\n",
2800 res->state & DLM_LOCK_RES_DIRTY ? "yes" : "no");
2801 /* if the extra ref we just put was the final one, this
2802 * will pass thru immediately. otherwise, we need to wait
2803 * for the last ast to finish. */
2804 again:
2805 ret = wait_event_interruptible_timeout(dlm->migration_wq,
2806 dlm_migration_can_proceed(dlm, res, target),
2807 msecs_to_jiffies(1000));
2808 if (ret < 0) {
2809 mlog(0, "woken again: migrating? %s, dead? %s\n",
2810 res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no",
2811 test_bit(target, dlm->domain_map) ? "no":"yes");
2812 } else {
2813 mlog(0, "all is well: migrating? %s, dead? %s\n",
2814 res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no",
2815 test_bit(target, dlm->domain_map) ? "no":"yes");
2817 if (!dlm_migration_can_proceed(dlm, res, target)) {
2818 mlog(0, "trying again...\n");
2819 goto again;
2822 ret = 0;
2823 /* did the target go down or die? */
2824 spin_lock(&dlm->spinlock);
2825 if (!test_bit(target, dlm->domain_map)) {
2826 mlog(ML_ERROR, "aha. migration target %u just went down\n",
2827 target);
2828 ret = -EHOSTDOWN;
2830 spin_unlock(&dlm->spinlock);
2833 * if target is down, we need to clear DLM_LOCK_RES_BLOCK_DIRTY for
2834 * another try; otherwise, we are sure the MIGRATING state is there,
2835 * drop the unneded state which blocked threads trying to DIRTY
2837 spin_lock(&res->spinlock);
2838 BUG_ON(!(res->state & DLM_LOCK_RES_BLOCK_DIRTY));
2839 res->state &= ~DLM_LOCK_RES_BLOCK_DIRTY;
2840 if (!ret)
2841 BUG_ON(!(res->state & DLM_LOCK_RES_MIGRATING));
2842 spin_unlock(&res->spinlock);
2845 * at this point:
2847 * o the DLM_LOCK_RES_MIGRATING flag is set if target not down
2848 * o there are no pending asts on this lockres
2849 * o all processes trying to reserve an ast on this
2850 * lockres must wait for the MIGRATING flag to clear
2852 return ret;
2855 /* last step in the migration process.
2856 * original master calls this to free all of the dlm_lock
2857 * structures that used to be for other nodes. */
2858 static void dlm_remove_nonlocal_locks(struct dlm_ctxt *dlm,
2859 struct dlm_lock_resource *res)
2861 struct list_head *queue = &res->granted;
2862 int i, bit;
2863 struct dlm_lock *lock, *next;
2865 assert_spin_locked(&res->spinlock);
2867 BUG_ON(res->owner == dlm->node_num);
2869 for (i=0; i<3; i++) {
2870 list_for_each_entry_safe(lock, next, queue, list) {
2871 if (lock->ml.node != dlm->node_num) {
2872 mlog(0, "putting lock for node %u\n",
2873 lock->ml.node);
2874 /* be extra careful */
2875 BUG_ON(!list_empty(&lock->ast_list));
2876 BUG_ON(!list_empty(&lock->bast_list));
2877 BUG_ON(lock->ast_pending);
2878 BUG_ON(lock->bast_pending);
2879 dlm_lockres_clear_refmap_bit(dlm, res,
2880 lock->ml.node);
2881 list_del_init(&lock->list);
2882 dlm_lock_put(lock);
2883 /* In a normal unlock, we would have added a
2884 * DLM_UNLOCK_FREE_LOCK action. Force it. */
2885 dlm_lock_put(lock);
2888 queue++;
2890 bit = 0;
2891 while (1) {
2892 bit = find_next_bit(res->refmap, O2NM_MAX_NODES, bit);
2893 if (bit >= O2NM_MAX_NODES)
2894 break;
2895 /* do not clear the local node reference, if there is a
2896 * process holding this, let it drop the ref itself */
2897 if (bit != dlm->node_num) {
2898 mlog(0, "%s:%.*s: node %u had a ref to this "
2899 "migrating lockres, clearing\n", dlm->name,
2900 res->lockname.len, res->lockname.name, bit);
2901 dlm_lockres_clear_refmap_bit(dlm, res, bit);
2903 bit++;
2908 * Pick a node to migrate the lock resource to. This function selects a
2909 * potential target based first on the locks and then on refmap. It skips
2910 * nodes that are in the process of exiting the domain.
2912 static u8 dlm_pick_migration_target(struct dlm_ctxt *dlm,
2913 struct dlm_lock_resource *res)
2915 enum dlm_lockres_list idx;
2916 struct list_head *queue = &res->granted;
2917 struct dlm_lock *lock;
2918 int noderef;
2919 u8 nodenum = O2NM_MAX_NODES;
2921 assert_spin_locked(&dlm->spinlock);
2922 assert_spin_locked(&res->spinlock);
2924 /* Go through all the locks */
2925 for (idx = DLM_GRANTED_LIST; idx <= DLM_BLOCKED_LIST; idx++) {
2926 queue = dlm_list_idx_to_ptr(res, idx);
2927 list_for_each_entry(lock, queue, list) {
2928 if (lock->ml.node == dlm->node_num)
2929 continue;
2930 if (test_bit(lock->ml.node, dlm->exit_domain_map))
2931 continue;
2932 nodenum = lock->ml.node;
2933 goto bail;
2937 /* Go thru the refmap */
2938 noderef = -1;
2939 while (1) {
2940 noderef = find_next_bit(res->refmap, O2NM_MAX_NODES,
2941 noderef + 1);
2942 if (noderef >= O2NM_MAX_NODES)
2943 break;
2944 if (noderef == dlm->node_num)
2945 continue;
2946 if (test_bit(noderef, dlm->exit_domain_map))
2947 continue;
2948 nodenum = noderef;
2949 goto bail;
2952 bail:
2953 return nodenum;
2956 /* this is called by the new master once all lockres
2957 * data has been received */
2958 static int dlm_do_migrate_request(struct dlm_ctxt *dlm,
2959 struct dlm_lock_resource *res,
2960 u8 master, u8 new_master,
2961 struct dlm_node_iter *iter)
2963 struct dlm_migrate_request migrate;
2964 int ret, skip, status = 0;
2965 int nodenum;
2967 memset(&migrate, 0, sizeof(migrate));
2968 migrate.namelen = res->lockname.len;
2969 memcpy(migrate.name, res->lockname.name, migrate.namelen);
2970 migrate.new_master = new_master;
2971 migrate.master = master;
2973 ret = 0;
2975 /* send message to all nodes, except the master and myself */
2976 while ((nodenum = dlm_node_iter_next(iter)) >= 0) {
2977 if (nodenum == master ||
2978 nodenum == new_master)
2979 continue;
2981 /* We could race exit domain. If exited, skip. */
2982 spin_lock(&dlm->spinlock);
2983 skip = (!test_bit(nodenum, dlm->domain_map));
2984 spin_unlock(&dlm->spinlock);
2985 if (skip) {
2986 clear_bit(nodenum, iter->node_map);
2987 continue;
2990 ret = o2net_send_message(DLM_MIGRATE_REQUEST_MSG, dlm->key,
2991 &migrate, sizeof(migrate), nodenum,
2992 &status);
2993 if (ret < 0) {
2994 mlog(ML_ERROR, "%s: res %.*s, Error %d send "
2995 "MIGRATE_REQUEST to node %u\n", dlm->name,
2996 migrate.namelen, migrate.name, ret, nodenum);
2997 if (!dlm_is_host_down(ret)) {
2998 mlog(ML_ERROR, "unhandled error=%d!\n", ret);
2999 BUG();
3001 clear_bit(nodenum, iter->node_map);
3002 ret = 0;
3003 } else if (status < 0) {
3004 mlog(0, "migrate request (node %u) returned %d!\n",
3005 nodenum, status);
3006 ret = status;
3007 } else if (status == DLM_MIGRATE_RESPONSE_MASTERY_REF) {
3008 /* during the migration request we short-circuited
3009 * the mastery of the lockres. make sure we have
3010 * a mastery ref for nodenum */
3011 mlog(0, "%s:%.*s: need ref for node %u\n",
3012 dlm->name, res->lockname.len, res->lockname.name,
3013 nodenum);
3014 spin_lock(&res->spinlock);
3015 dlm_lockres_set_refmap_bit(dlm, res, nodenum);
3016 spin_unlock(&res->spinlock);
3020 if (ret < 0)
3021 mlog_errno(ret);
3023 mlog(0, "returning ret=%d\n", ret);
3024 return ret;
3028 /* if there is an existing mle for this lockres, we now know who the master is.
3029 * (the one who sent us *this* message) we can clear it up right away.
3030 * since the process that put the mle on the list still has a reference to it,
3031 * we can unhash it now, set the master and wake the process. as a result,
3032 * we will have no mle in the list to start with. now we can add an mle for
3033 * the migration and this should be the only one found for those scanning the
3034 * list. */
3035 int dlm_migrate_request_handler(struct o2net_msg *msg, u32 len, void *data,
3036 void **ret_data)
3038 struct dlm_ctxt *dlm = data;
3039 struct dlm_lock_resource *res = NULL;
3040 struct dlm_migrate_request *migrate = (struct dlm_migrate_request *) msg->buf;
3041 struct dlm_master_list_entry *mle = NULL, *oldmle = NULL;
3042 const char *name;
3043 unsigned int namelen, hash;
3044 int ret = 0;
3046 if (!dlm_grab(dlm))
3047 return -EINVAL;
3049 name = migrate->name;
3050 namelen = migrate->namelen;
3051 hash = dlm_lockid_hash(name, namelen);
3053 /* preallocate.. if this fails, abort */
3054 mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
3056 if (!mle) {
3057 ret = -ENOMEM;
3058 goto leave;
3061 /* check for pre-existing lock */
3062 spin_lock(&dlm->spinlock);
3063 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
3064 if (res) {
3065 spin_lock(&res->spinlock);
3066 if (res->state & DLM_LOCK_RES_RECOVERING) {
3067 /* if all is working ok, this can only mean that we got
3068 * a migrate request from a node that we now see as
3069 * dead. what can we do here? drop it to the floor? */
3070 spin_unlock(&res->spinlock);
3071 mlog(ML_ERROR, "Got a migrate request, but the "
3072 "lockres is marked as recovering!");
3073 kmem_cache_free(dlm_mle_cache, mle);
3074 ret = -EINVAL; /* need a better solution */
3075 goto unlock;
3077 res->state |= DLM_LOCK_RES_MIGRATING;
3078 spin_unlock(&res->spinlock);
3081 spin_lock(&dlm->master_lock);
3082 /* ignore status. only nonzero status would BUG. */
3083 ret = dlm_add_migration_mle(dlm, res, mle, &oldmle,
3084 name, namelen,
3085 migrate->new_master,
3086 migrate->master);
3088 spin_unlock(&dlm->master_lock);
3089 unlock:
3090 spin_unlock(&dlm->spinlock);
3092 if (oldmle) {
3093 /* master is known, detach if not already detached */
3094 dlm_mle_detach_hb_events(dlm, oldmle);
3095 dlm_put_mle(oldmle);
3098 if (res)
3099 dlm_lockres_put(res);
3100 leave:
3101 dlm_put(dlm);
3102 return ret;
3105 /* must be holding dlm->spinlock and dlm->master_lock
3106 * when adding a migration mle, we can clear any other mles
3107 * in the master list because we know with certainty that
3108 * the master is "master". so we remove any old mle from
3109 * the list after setting it's master field, and then add
3110 * the new migration mle. this way we can hold with the rule
3111 * of having only one mle for a given lock name at all times. */
3112 static int dlm_add_migration_mle(struct dlm_ctxt *dlm,
3113 struct dlm_lock_resource *res,
3114 struct dlm_master_list_entry *mle,
3115 struct dlm_master_list_entry **oldmle,
3116 const char *name, unsigned int namelen,
3117 u8 new_master, u8 master)
3119 int found;
3120 int ret = 0;
3122 *oldmle = NULL;
3124 assert_spin_locked(&dlm->spinlock);
3125 assert_spin_locked(&dlm->master_lock);
3127 /* caller is responsible for any ref taken here on oldmle */
3128 found = dlm_find_mle(dlm, oldmle, (char *)name, namelen);
3129 if (found) {
3130 struct dlm_master_list_entry *tmp = *oldmle;
3131 spin_lock(&tmp->spinlock);
3132 if (tmp->type == DLM_MLE_MIGRATION) {
3133 if (master == dlm->node_num) {
3134 /* ah another process raced me to it */
3135 mlog(0, "tried to migrate %.*s, but some "
3136 "process beat me to it\n",
3137 namelen, name);
3138 ret = -EEXIST;
3139 } else {
3140 /* bad. 2 NODES are trying to migrate! */
3141 mlog(ML_ERROR, "migration error mle: "
3142 "master=%u new_master=%u // request: "
3143 "master=%u new_master=%u // "
3144 "lockres=%.*s\n",
3145 tmp->master, tmp->new_master,
3146 master, new_master,
3147 namelen, name);
3148 BUG();
3150 } else {
3151 /* this is essentially what assert_master does */
3152 tmp->master = master;
3153 atomic_set(&tmp->woken, 1);
3154 wake_up(&tmp->wq);
3155 /* remove it so that only one mle will be found */
3156 __dlm_unlink_mle(dlm, tmp);
3157 __dlm_mle_detach_hb_events(dlm, tmp);
3158 if (tmp->type == DLM_MLE_MASTER) {
3159 ret = DLM_MIGRATE_RESPONSE_MASTERY_REF;
3160 mlog(0, "%s:%.*s: master=%u, newmaster=%u, "
3161 "telling master to get ref "
3162 "for cleared out mle during "
3163 "migration\n", dlm->name,
3164 namelen, name, master,
3165 new_master);
3168 spin_unlock(&tmp->spinlock);
3171 /* now add a migration mle to the tail of the list */
3172 dlm_init_mle(mle, DLM_MLE_MIGRATION, dlm, res, name, namelen);
3173 mle->new_master = new_master;
3174 /* the new master will be sending an assert master for this.
3175 * at that point we will get the refmap reference */
3176 mle->master = master;
3177 /* do this for consistency with other mle types */
3178 set_bit(new_master, mle->maybe_map);
3179 __dlm_insert_mle(dlm, mle);
3181 return ret;
3185 * Sets the owner of the lockres, associated to the mle, to UNKNOWN
3187 static struct dlm_lock_resource *dlm_reset_mleres_owner(struct dlm_ctxt *dlm,
3188 struct dlm_master_list_entry *mle)
3190 struct dlm_lock_resource *res;
3192 /* Find the lockres associated to the mle and set its owner to UNK */
3193 res = __dlm_lookup_lockres(dlm, mle->mname, mle->mnamelen,
3194 mle->mnamehash);
3195 if (res) {
3196 spin_unlock(&dlm->master_lock);
3198 /* move lockres onto recovery list */
3199 spin_lock(&res->spinlock);
3200 dlm_set_lockres_owner(dlm, res, DLM_LOCK_RES_OWNER_UNKNOWN);
3201 dlm_move_lockres_to_recovery_list(dlm, res);
3202 spin_unlock(&res->spinlock);
3203 dlm_lockres_put(res);
3205 /* about to get rid of mle, detach from heartbeat */
3206 __dlm_mle_detach_hb_events(dlm, mle);
3208 /* dump the mle */
3209 spin_lock(&dlm->master_lock);
3210 __dlm_put_mle(mle);
3211 spin_unlock(&dlm->master_lock);
3214 return res;
3217 static void dlm_clean_migration_mle(struct dlm_ctxt *dlm,
3218 struct dlm_master_list_entry *mle)
3220 __dlm_mle_detach_hb_events(dlm, mle);
3222 spin_lock(&mle->spinlock);
3223 __dlm_unlink_mle(dlm, mle);
3224 atomic_set(&mle->woken, 1);
3225 spin_unlock(&mle->spinlock);
3227 wake_up(&mle->wq);
3230 static void dlm_clean_block_mle(struct dlm_ctxt *dlm,
3231 struct dlm_master_list_entry *mle, u8 dead_node)
3233 int bit;
3235 BUG_ON(mle->type != DLM_MLE_BLOCK);
3237 spin_lock(&mle->spinlock);
3238 bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0);
3239 if (bit != dead_node) {
3240 mlog(0, "mle found, but dead node %u would not have been "
3241 "master\n", dead_node);
3242 spin_unlock(&mle->spinlock);
3243 } else {
3244 /* Must drop the refcount by one since the assert_master will
3245 * never arrive. This may result in the mle being unlinked and
3246 * freed, but there may still be a process waiting in the
3247 * dlmlock path which is fine. */
3248 mlog(0, "node %u was expected master\n", dead_node);
3249 atomic_set(&mle->woken, 1);
3250 spin_unlock(&mle->spinlock);
3251 wake_up(&mle->wq);
3253 /* Do not need events any longer, so detach from heartbeat */
3254 __dlm_mle_detach_hb_events(dlm, mle);
3255 __dlm_put_mle(mle);
3259 void dlm_clean_master_list(struct dlm_ctxt *dlm, u8 dead_node)
3261 struct dlm_master_list_entry *mle;
3262 struct dlm_lock_resource *res;
3263 struct hlist_head *bucket;
3264 struct hlist_node *tmp;
3265 unsigned int i;
3267 mlog(0, "dlm=%s, dead node=%u\n", dlm->name, dead_node);
3268 top:
3269 assert_spin_locked(&dlm->spinlock);
3271 /* clean the master list */
3272 spin_lock(&dlm->master_lock);
3273 for (i = 0; i < DLM_HASH_BUCKETS; i++) {
3274 bucket = dlm_master_hash(dlm, i);
3275 hlist_for_each_entry_safe(mle, tmp, bucket, master_hash_node) {
3276 BUG_ON(mle->type != DLM_MLE_BLOCK &&
3277 mle->type != DLM_MLE_MASTER &&
3278 mle->type != DLM_MLE_MIGRATION);
3280 /* MASTER mles are initiated locally. The waiting
3281 * process will notice the node map change shortly.
3282 * Let that happen as normal. */
3283 if (mle->type == DLM_MLE_MASTER)
3284 continue;
3286 /* BLOCK mles are initiated by other nodes. Need to
3287 * clean up if the dead node would have been the
3288 * master. */
3289 if (mle->type == DLM_MLE_BLOCK) {
3290 dlm_clean_block_mle(dlm, mle, dead_node);
3291 continue;
3294 /* Everything else is a MIGRATION mle */
3296 /* The rule for MIGRATION mles is that the master
3297 * becomes UNKNOWN if *either* the original or the new
3298 * master dies. All UNKNOWN lockres' are sent to
3299 * whichever node becomes the recovery master. The new
3300 * master is responsible for determining if there is
3301 * still a master for this lockres, or if he needs to
3302 * take over mastery. Either way, this node should
3303 * expect another message to resolve this. */
3305 if (mle->master != dead_node &&
3306 mle->new_master != dead_node)
3307 continue;
3309 /* If we have reached this point, this mle needs to be
3310 * removed from the list and freed. */
3311 dlm_clean_migration_mle(dlm, mle);
3313 mlog(0, "%s: node %u died during migration from "
3314 "%u to %u!\n", dlm->name, dead_node, mle->master,
3315 mle->new_master);
3317 /* If we find a lockres associated with the mle, we've
3318 * hit this rare case that messes up our lock ordering.
3319 * If so, we need to drop the master lock so that we can
3320 * take the lockres lock, meaning that we will have to
3321 * restart from the head of list. */
3322 res = dlm_reset_mleres_owner(dlm, mle);
3323 if (res)
3324 /* restart */
3325 goto top;
3327 /* This may be the last reference */
3328 __dlm_put_mle(mle);
3331 spin_unlock(&dlm->master_lock);
3334 int dlm_finish_migration(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
3335 u8 old_master)
3337 struct dlm_node_iter iter;
3338 int ret = 0;
3340 spin_lock(&dlm->spinlock);
3341 dlm_node_iter_init(dlm->domain_map, &iter);
3342 clear_bit(old_master, iter.node_map);
3343 clear_bit(dlm->node_num, iter.node_map);
3344 spin_unlock(&dlm->spinlock);
3346 /* ownership of the lockres is changing. account for the
3347 * mastery reference here since old_master will briefly have
3348 * a reference after the migration completes */
3349 spin_lock(&res->spinlock);
3350 dlm_lockres_set_refmap_bit(dlm, res, old_master);
3351 spin_unlock(&res->spinlock);
3353 mlog(0, "now time to do a migrate request to other nodes\n");
3354 ret = dlm_do_migrate_request(dlm, res, old_master,
3355 dlm->node_num, &iter);
3356 if (ret < 0) {
3357 mlog_errno(ret);
3358 goto leave;
3361 mlog(0, "doing assert master of %.*s to all except the original node\n",
3362 res->lockname.len, res->lockname.name);
3363 /* this call now finishes out the nodemap
3364 * even if one or more nodes die */
3365 ret = dlm_do_assert_master(dlm, res, iter.node_map,
3366 DLM_ASSERT_MASTER_FINISH_MIGRATION);
3367 if (ret < 0) {
3368 /* no longer need to retry. all living nodes contacted. */
3369 mlog_errno(ret);
3370 ret = 0;
3373 memset(iter.node_map, 0, sizeof(iter.node_map));
3374 set_bit(old_master, iter.node_map);
3375 mlog(0, "doing assert master of %.*s back to %u\n",
3376 res->lockname.len, res->lockname.name, old_master);
3377 ret = dlm_do_assert_master(dlm, res, iter.node_map,
3378 DLM_ASSERT_MASTER_FINISH_MIGRATION);
3379 if (ret < 0) {
3380 mlog(0, "assert master to original master failed "
3381 "with %d.\n", ret);
3382 /* the only nonzero status here would be because of
3383 * a dead original node. we're done. */
3384 ret = 0;
3387 /* all done, set the owner, clear the flag */
3388 spin_lock(&res->spinlock);
3389 dlm_set_lockres_owner(dlm, res, dlm->node_num);
3390 res->state &= ~DLM_LOCK_RES_MIGRATING;
3391 spin_unlock(&res->spinlock);
3392 /* re-dirty it on the new master */
3393 dlm_kick_thread(dlm, res);
3394 wake_up(&res->wq);
3395 leave:
3396 return ret;
3400 * LOCKRES AST REFCOUNT
3401 * this is integral to migration
3404 /* for future intent to call an ast, reserve one ahead of time.
3405 * this should be called only after waiting on the lockres
3406 * with dlm_wait_on_lockres, and while still holding the
3407 * spinlock after the call. */
3408 void __dlm_lockres_reserve_ast(struct dlm_lock_resource *res)
3410 assert_spin_locked(&res->spinlock);
3411 if (res->state & DLM_LOCK_RES_MIGRATING) {
3412 __dlm_print_one_lock_resource(res);
3414 BUG_ON(res->state & DLM_LOCK_RES_MIGRATING);
3416 atomic_inc(&res->asts_reserved);
3420 * used to drop the reserved ast, either because it went unused,
3421 * or because the ast/bast was actually called.
3423 * also, if there is a pending migration on this lockres,
3424 * and this was the last pending ast on the lockres,
3425 * atomically set the MIGRATING flag before we drop the lock.
3426 * this is how we ensure that migration can proceed with no
3427 * asts in progress. note that it is ok if the state of the
3428 * queues is such that a lock should be granted in the future
3429 * or that a bast should be fired, because the new master will
3430 * shuffle the lists on this lockres as soon as it is migrated.
3432 void dlm_lockres_release_ast(struct dlm_ctxt *dlm,
3433 struct dlm_lock_resource *res)
3435 if (!atomic_dec_and_lock(&res->asts_reserved, &res->spinlock))
3436 return;
3438 if (!res->migration_pending) {
3439 spin_unlock(&res->spinlock);
3440 return;
3443 BUG_ON(res->state & DLM_LOCK_RES_MIGRATING);
3444 res->migration_pending = 0;
3445 res->state |= DLM_LOCK_RES_MIGRATING;
3446 spin_unlock(&res->spinlock);
3447 wake_up(&res->wq);
3448 wake_up(&dlm->migration_wq);
3451 void dlm_force_free_mles(struct dlm_ctxt *dlm)
3453 int i;
3454 struct hlist_head *bucket;
3455 struct dlm_master_list_entry *mle;
3456 struct hlist_node *tmp;
3459 * We notified all other nodes that we are exiting the domain and
3460 * marked the dlm state to DLM_CTXT_LEAVING. If any mles are still
3461 * around we force free them and wake any processes that are waiting
3462 * on the mles
3464 spin_lock(&dlm->spinlock);
3465 spin_lock(&dlm->master_lock);
3467 BUG_ON(dlm->dlm_state != DLM_CTXT_LEAVING);
3468 BUG_ON((find_next_bit(dlm->domain_map, O2NM_MAX_NODES, 0) < O2NM_MAX_NODES));
3470 for (i = 0; i < DLM_HASH_BUCKETS; i++) {
3471 bucket = dlm_master_hash(dlm, i);
3472 hlist_for_each_entry_safe(mle, tmp, bucket, master_hash_node) {
3473 if (mle->type != DLM_MLE_BLOCK) {
3474 mlog(ML_ERROR, "bad mle: %p\n", mle);
3475 dlm_print_one_mle(mle);
3477 atomic_set(&mle->woken, 1);
3478 wake_up(&mle->wq);
3480 __dlm_unlink_mle(dlm, mle);
3481 __dlm_mle_detach_hb_events(dlm, mle);
3482 __dlm_put_mle(mle);
3485 spin_unlock(&dlm->master_lock);
3486 spin_unlock(&dlm->spinlock);