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ocfs2: clean up redundant NULL check before iput
[linux-2.6-block.git] / fs / ocfs2 / dlm / dlmmaster.c
CommitLineData
6714d8e8
KH		 1/* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * dlmmod.c
5 *
6 * standalone DLM module
7 *
8 * Copyright (C) 2004 Oracle. All rights reserved.
9 *
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.
14 *
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.
19 *
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.
24 *
25 */
26
27
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>
6714d8e8
KH		 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>
41
42
43#include "cluster/heartbeat.h"
44#include "cluster/nodemanager.h"
45#include "cluster/tcp.h"
46
47#include "dlmapi.h"
48#include "dlmcommon.h"
82353b59 49#include "dlmdomain.h"
e5a0334c 50#include "dlmdebug.h"
6714d8e8
KH		 51
52#define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_MASTER)
53#include "cluster/masklog.h"
54
6714d8e8
KH		 55static void dlm_mle_node_down(struct dlm_ctxt *dlm,
56 struct dlm_master_list_entry *mle,
57 struct o2nm_node *node,
58 int idx);
59static void dlm_mle_node_up(struct dlm_ctxt *dlm,
60 struct dlm_master_list_entry *mle,
61 struct o2nm_node *node,
62 int idx);
63
64static void dlm_assert_master_worker(struct dlm_work_item *item, void *data);
ba2bf218
KH		 65static int dlm_do_assert_master(struct dlm_ctxt *dlm,
66 struct dlm_lock_resource *res,
67 void *nodemap, u32 flags);
f3f85464 68static void dlm_deref_lockres_worker(struct dlm_work_item *item, void *data);
6714d8e8
KH		 69
70static inline int dlm_mle_equal(struct dlm_ctxt *dlm,
71 struct dlm_master_list_entry *mle,
72 const char *name,
73 unsigned int namelen)
74{
6714d8e8
KH		 75 if (dlm != mle->dlm)
76 return 0;
77
7141514b
SM		 78 if (namelen != mle->mnamelen ||
79 memcmp(name, mle->mname, namelen) != 0)
f77a9a78
SM		 80 return 0;
81
6714d8e8
KH		 82 return 1;
83}
84
1a5c4e2a
FF		 85static struct kmem_cache *dlm_lockres_cache;
86static struct kmem_cache *dlm_lockname_cache;
87static struct kmem_cache *dlm_mle_cache;
6714d8e8 88
6714d8e8
KH		 89static void dlm_mle_release(struct kref *kref);
90static 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);
96static void dlm_put_mle(struct dlm_master_list_entry *mle);
97static void __dlm_put_mle(struct dlm_master_list_entry *mle);
98static int dlm_find_mle(struct dlm_ctxt *dlm,
99 struct dlm_master_list_entry **mle,
100 char *name, unsigned int namelen);
101
ba2bf218
KH		 102static int dlm_do_master_request(struct dlm_lock_resource *res,
103 struct dlm_master_list_entry *mle, int to);
6714d8e8
KH		 104
105
106static 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);
110static 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);
114static 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);
120
121static u8 dlm_pick_migration_target(struct dlm_ctxt *dlm,
122 struct dlm_lock_resource *res);
123static void dlm_remove_nonlocal_locks(struct dlm_ctxt *dlm,
124 struct dlm_lock_resource *res);
125static int dlm_mark_lockres_migrating(struct dlm_ctxt *dlm,
126 struct dlm_lock_resource *res,
127 u8 target);
c03872f5
KH		 128static int dlm_pre_master_reco_lockres(struct dlm_ctxt *dlm,
129 struct dlm_lock_resource *res);
6714d8e8
KH		 130
131
132int dlm_is_host_down(int errno)
133{
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;
152 }
153 return 0;
154}
155
156
157/*
158 * MASTER LIST FUNCTIONS
159 */
160
161
162/*
163 * regarding master list entries and heartbeat callbacks:
164 *
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.
173 *
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.
177 */
178static inline void __dlm_mle_attach_hb_events(struct dlm_ctxt *dlm,
179 struct dlm_master_list_entry *mle)
180{
181 assert_spin_locked(&dlm->spinlock);
182
183 list_add_tail(&mle->hb_events, &dlm->mle_hb_events);
184}
185
186
187static inline void __dlm_mle_detach_hb_events(struct dlm_ctxt *dlm,
188 struct dlm_master_list_entry *mle)
189{
190 if (!list_empty(&mle->hb_events))
191 list_del_init(&mle->hb_events);
192}
193
194
195static inline void dlm_mle_detach_hb_events(struct dlm_ctxt *dlm,
196 struct dlm_master_list_entry *mle)
197{
198 spin_lock(&dlm->spinlock);
199 __dlm_mle_detach_hb_events(dlm, mle);
200 spin_unlock(&dlm->spinlock);
201}
202
a2bf0477
KH		 203static void dlm_get_mle_inuse(struct dlm_master_list_entry *mle)
204{
205 struct dlm_ctxt *dlm;
206 dlm = mle->dlm;
207
208 assert_spin_locked(&dlm->spinlock);
209 assert_spin_locked(&dlm->master_lock);
210 mle->inuse++;
211 kref_get(&mle->mle_refs);
212}
213
214static void dlm_put_mle_inuse(struct dlm_master_list_entry *mle)
215{
216 struct dlm_ctxt *dlm;
217 dlm = mle->dlm;
218
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);
225
226}
227
6714d8e8
KH		 228/* remove from list and free */
229static void __dlm_put_mle(struct dlm_master_list_entry *mle)
230{
231 struct dlm_ctxt *dlm;
232 dlm = mle->dlm;
233
234 assert_spin_locked(&dlm->spinlock);
235 assert_spin_locked(&dlm->master_lock);
aa852354
KH		 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);
6714d8e8
KH		 244}
245
246
247/* must not have any spinlocks coming in */
248static void dlm_put_mle(struct dlm_master_list_entry *mle)
249{
250 struct dlm_ctxt *dlm;
251 dlm = mle->dlm;
252
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);
258}
259
260static inline void dlm_get_mle(struct dlm_master_list_entry *mle)
261{
262 kref_get(&mle->mle_refs);
263}
264
265static 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)
271{
272 assert_spin_locked(&dlm->spinlock);
273
274 mle->dlm = dlm;
275 mle->type = type;
2ed6c750 276 INIT_HLIST_NODE(&mle->master_hash_node);
6714d8e8
KH		 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;
a2bf0477 286 mle->inuse = 0;
6714d8e8 287
f77a9a78
SM		 288 BUG_ON(mle->type != DLM_MLE_BLOCK &&
289 mle->type != DLM_MLE_MASTER &&
290 mle->type != DLM_MLE_MIGRATION);
291
6714d8e8
KH		 292 if (mle->type == DLM_MLE_MASTER) {
293 BUG_ON(!res);
7141514b
SM		 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;
f77a9a78 298 } else {
6714d8e8 299 BUG_ON(!name);
7141514b
SM		 300 mle->mleres = NULL;
301 memcpy(mle->mname, name, namelen);
302 mle->mnamelen = namelen;
303 mle->mnamehash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 304 }
305
2041d8fd
SM		 306 atomic_inc(&dlm->mle_tot_count[mle->type]);
307 atomic_inc(&dlm->mle_cur_count[mle->type]);
308
6714d8e8
KH		 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);
314
315 /* attach the mle to the domain node up/down events */
316 __dlm_mle_attach_hb_events(dlm, mle);
317}
318
1c084577
SM		 319void __dlm_unlink_mle(struct dlm_ctxt *dlm, struct dlm_master_list_entry *mle)
320{
321 assert_spin_locked(&dlm->spinlock);
322 assert_spin_locked(&dlm->master_lock);
323
2ed6c750
SM		 324 if (!hlist_unhashed(&mle->master_hash_node))
325 hlist_del_init(&mle->master_hash_node);
1c084577
SM		 326}
327
328void __dlm_insert_mle(struct dlm_ctxt *dlm, struct dlm_master_list_entry *mle)
329{
2ed6c750 330 struct hlist_head *bucket;
2ed6c750 331
1c084577
SM		 332 assert_spin_locked(&dlm->master_lock);
333
7141514b 334 bucket = dlm_master_hash(dlm, mle->mnamehash);
2ed6c750 335 hlist_add_head(&mle->master_hash_node, bucket);
1c084577 336}
6714d8e8
KH		 337
338/* returns 1 if found, 0 if not */
339static int dlm_find_mle(struct dlm_ctxt *dlm,
340 struct dlm_master_list_entry **mle,
341 char *name, unsigned int namelen)
342{
343 struct dlm_master_list_entry *tmpmle;
2ed6c750 344 struct hlist_head *bucket;
2ed6c750 345 unsigned int hash;
6714d8e8
KH		 346
347 assert_spin_locked(&dlm->master_lock);
348
2ed6c750
SM		 349 hash = dlm_lockid_hash(name, namelen);
350 bucket = dlm_master_hash(dlm, hash);
df53cd3b 351 hlist_for_each_entry(tmpmle, bucket, master_hash_node) {
6714d8e8
KH		 352 if (!dlm_mle_equal(dlm, tmpmle, name, namelen))
353 continue;
354 dlm_get_mle(tmpmle);
355 *mle = tmpmle;
356 return 1;
357 }
358 return 0;
359}
360
361void dlm_hb_event_notify_attached(struct dlm_ctxt *dlm, int idx, int node_up)
362{
363 struct dlm_master_list_entry *mle;
6714d8e8
KH		 364
365 assert_spin_locked(&dlm->spinlock);
2bd63216 366
800deef3 367 list_for_each_entry(mle, &dlm->mle_hb_events, hb_events) {
6714d8e8
KH		 368 if (node_up)
369 dlm_mle_node_up(dlm, mle, NULL, idx);
370 else
371 dlm_mle_node_down(dlm, mle, NULL, idx);
372 }
373}
374
375static void dlm_mle_node_down(struct dlm_ctxt *dlm,
376 struct dlm_master_list_entry *mle,
377 struct o2nm_node *node, int idx)
378{
379 spin_lock(&mle->spinlock);
380
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);
385
386 spin_unlock(&mle->spinlock);
387}
388
389static void dlm_mle_node_up(struct dlm_ctxt *dlm,
390 struct dlm_master_list_entry *mle,
391 struct o2nm_node *node, int idx)
392{
393 spin_lock(&mle->spinlock);
394
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);
399
400 spin_unlock(&mle->spinlock);
401}
402
403
404int dlm_init_mle_cache(void)
405{
12eb0035 406 dlm_mle_cache = kmem_cache_create("o2dlm_mle",
6714d8e8
KH		 407 sizeof(struct dlm_master_list_entry),
408 0, SLAB_HWCACHE_ALIGN,
20c2df83 409 NULL);
6714d8e8
KH		 410 if (dlm_mle_cache == NULL)
411 return -ENOMEM;
412 return 0;
413}
414
415void dlm_destroy_mle_cache(void)
416{
417 if (dlm_mle_cache)
418 kmem_cache_destroy(dlm_mle_cache);
419}
420
421static void dlm_mle_release(struct kref *kref)
422{
423 struct dlm_master_list_entry *mle;
424 struct dlm_ctxt *dlm;
425
6714d8e8
KH		 426 mle = container_of(kref, struct dlm_master_list_entry, mle_refs);
427 dlm = mle->dlm;
428
6714d8e8
KH		 429 assert_spin_locked(&dlm->spinlock);
430 assert_spin_locked(&dlm->master_lock);
431
7141514b
SM		 432 mlog(0, "Releasing mle for %.*s, type %d\n", mle->mnamelen, mle->mname,
433 mle->type);
2ed6c750 434
6714d8e8 435 /* remove from list if not already */
1c084577 436 __dlm_unlink_mle(dlm, mle);
6714d8e8
KH		 437
438 /* detach the mle from the domain node up/down events */
439 __dlm_mle_detach_hb_events(dlm, mle);
440
2041d8fd
SM		 441 atomic_dec(&dlm->mle_cur_count[mle->type]);
442
6714d8e8
KH		 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);
446}
447
448
449/*
450 * LOCK RESOURCE FUNCTIONS
451 */
452
724bdca9
SM		 453int dlm_init_master_caches(void)
454{
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;
460
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;
466
467 return 0;
468bail:
469 dlm_destroy_master_caches();
470 return -ENOMEM;
471}
472
473void dlm_destroy_master_caches(void)
474{
66db6cfd 475 if (dlm_lockname_cache) {
724bdca9 476 kmem_cache_destroy(dlm_lockname_cache);
66db6cfd
JQ		 477 dlm_lockname_cache = NULL;
478 }
724bdca9 479
66db6cfd 480 if (dlm_lockres_cache) {
724bdca9 481 kmem_cache_destroy(dlm_lockres_cache);
66db6cfd
JQ		 482 dlm_lockres_cache = NULL;
483 }
724bdca9
SM		 484}
485
6714d8e8
KH		 486static void dlm_lockres_release(struct kref *kref)
487{
488 struct dlm_lock_resource *res;
b0d4f817 489 struct dlm_ctxt *dlm;
6714d8e8
KH		 490
491 res = container_of(kref, struct dlm_lock_resource, refs);
b0d4f817 492 dlm = res->dlm;
6714d8e8
KH		 493
494 /* This should not happen -- all lockres' have a name
495 * associated with them at init time. */
496 BUG_ON(!res->lockname.name);
497
498 mlog(0, "destroying lockres %.*s\n", res->lockname.len,
499 res->lockname.name);
500
6800791a
SM		 501 atomic_dec(&dlm->res_cur_count);
502
a7f90d83
KH		 503 if (!hlist_unhashed(&res->hash_node) ||
504 !list_empty(&res->granted) ||
505 !list_empty(&res->converting) ||
506 !list_empty(&res->blocked) ||
507 !list_empty(&res->dirty) ||
508 !list_empty(&res->recovering) ||
509 !list_empty(&res->purge)) {
510 mlog(ML_ERROR,
511 "Going to BUG for resource %.*s."
512 " We're on a list! [%c%c%c%c%c%c%c]\n",
513 res->lockname.len, res->lockname.name,
514 !hlist_unhashed(&res->hash_node) ? 'H' : ' ',
515 !list_empty(&res->granted) ? 'G' : ' ',
516 !list_empty(&res->converting) ? 'C' : ' ',
517 !list_empty(&res->blocked) ? 'B' : ' ',
518 !list_empty(&res->dirty) ? 'D' : ' ',
519 !list_empty(&res->recovering) ? 'R' : ' ',
520 !list_empty(&res->purge) ? 'P' : ' ');
521
522 dlm_print_one_lock_resource(res);
523 }
524
6714d8e8
KH		 525 /* By the time we're ready to blow this guy away, we shouldn't
526 * be on any lists. */
81f2094a 527 BUG_ON(!hlist_unhashed(&res->hash_node));
6714d8e8
KH		 528 BUG_ON(!list_empty(&res->granted));
529 BUG_ON(!list_empty(&res->converting));
530 BUG_ON(!list_empty(&res->blocked));
531 BUG_ON(!list_empty(&res->dirty));
532 BUG_ON(!list_empty(&res->recovering));
533 BUG_ON(!list_empty(&res->purge));
534
724bdca9 535 kmem_cache_free(dlm_lockname_cache, (void *)res->lockname.name);
6714d8e8 536
724bdca9 537 kmem_cache_free(dlm_lockres_cache, res);
6714d8e8
KH		 538}
539
6714d8e8
KH		 540void dlm_lockres_put(struct dlm_lock_resource *res)
541{
542 kref_put(&res->refs, dlm_lockres_release);
543}
544
545static void dlm_init_lockres(struct dlm_ctxt *dlm,
546 struct dlm_lock_resource *res,
547 const char *name, unsigned int namelen)
548{
549 char *qname;
550
551 /* If we memset here, we lose our reference to the kmalloc'd
552 * res->lockname.name, so be sure to init every field
553 * correctly! */
554
555 qname = (char *) res->lockname.name;
556 memcpy(qname, name, namelen);
557
558 res->lockname.len = namelen;
a3d33291 559 res->lockname.hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 560
561 init_waitqueue_head(&res->wq);
562 spin_lock_init(&res->spinlock);
81f2094a 563 INIT_HLIST_NODE(&res->hash_node);
6714d8e8
KH		 564 INIT_LIST_HEAD(&res->granted);
565 INIT_LIST_HEAD(&res->converting);
566 INIT_LIST_HEAD(&res->blocked);
567 INIT_LIST_HEAD(&res->dirty);
568 INIT_LIST_HEAD(&res->recovering);
569 INIT_LIST_HEAD(&res->purge);
29576f8b 570 INIT_LIST_HEAD(&res->tracking);
6714d8e8
KH		 571 atomic_set(&res->asts_reserved, 0);
572 res->migration_pending = 0;
ba2bf218 573 res->inflight_locks = 0;
ac4fef4d 574 res->inflight_assert_workers = 0;
6714d8e8 575
b0d4f817
SM		 576 res->dlm = dlm;
577
6714d8e8
KH		 578 kref_init(&res->refs);
579
6800791a
SM		 580 atomic_inc(&dlm->res_tot_count);
581 atomic_inc(&dlm->res_cur_count);
582
6714d8e8
KH		 583 /* just for consistency */
584 spin_lock(&res->spinlock);
585 dlm_set_lockres_owner(dlm, res, DLM_LOCK_RES_OWNER_UNKNOWN);
586 spin_unlock(&res->spinlock);
587
588 res->state = DLM_LOCK_RES_IN_PROGRESS;
589
590 res->last_used = 0;
591
18c6ac38 592 spin_lock(&dlm->spinlock);
29576f8b 593 list_add_tail(&res->tracking, &dlm->tracking_list);
18c6ac38 594 spin_unlock(&dlm->spinlock);
29576f8b 595
6714d8e8 596 memset(res->lvb, 0, DLM_LVB_LEN);
ba2bf218 597 memset(res->refmap, 0, sizeof(res->refmap));
6714d8e8
KH		 598}
599
600struct dlm_lock_resource *dlm_new_lockres(struct dlm_ctxt *dlm,
601 const char *name,
602 unsigned int namelen)
603{
724bdca9 604 struct dlm_lock_resource *res = NULL;
6714d8e8 605
3914ed0c 606 res = kmem_cache_zalloc(dlm_lockres_cache, GFP_NOFS);
6714d8e8 607 if (!res)
724bdca9 608 goto error;
6714d8e8 609
3914ed0c 610 res->lockname.name = kmem_cache_zalloc(dlm_lockname_cache, GFP_NOFS);
724bdca9
SM		 611 if (!res->lockname.name)
612 goto error;
6714d8e8
KH		 613
614 dlm_init_lockres(dlm, res, name, namelen);
615 return res;
724bdca9
SM		 616
617error:
724bdca9
SM		 618 if (res)
619 kmem_cache_free(dlm_lockres_cache, res);
620 return NULL;
6714d8e8
KH		 621}
622
8d400b81
SM		 623void dlm_lockres_set_refmap_bit(struct dlm_ctxt *dlm,
624 struct dlm_lock_resource *res, int bit)
ba2bf218 625{
8d400b81
SM		 626 assert_spin_locked(&res->spinlock);
627
628 mlog(0, "res %.*s, set node %u, %ps()\n", res->lockname.len,
629 res->lockname.name, bit, __builtin_return_address(0));
630
631 set_bit(bit, res->refmap);
632}
633
634void dlm_lockres_clear_refmap_bit(struct dlm_ctxt *dlm,
635 struct dlm_lock_resource *res, int bit)
636{
637 assert_spin_locked(&res->spinlock);
638
639 mlog(0, "res %.*s, clr node %u, %ps()\n", res->lockname.len,
640 res->lockname.name, bit, __builtin_return_address(0));
641
642 clear_bit(bit, res->refmap);
643}
644
5760a97c 645static void __dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm,
8d400b81
SM		 646 struct dlm_lock_resource *res)
647{
ba2bf218 648 res->inflight_locks++;
ff0a522e 649
8d400b81
SM		 650 mlog(0, "%s: res %.*s, inflight++: now %u, %ps()\n", dlm->name,
651 res->lockname.len, res->lockname.name, res->inflight_locks,
652 __builtin_return_address(0));
ba2bf218
KH		 653}
654
5760a97c
JQ		 655void dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm,
656 struct dlm_lock_resource *res)
657{
658 assert_spin_locked(&res->spinlock);
659 __dlm_lockres_grab_inflight_ref(dlm, res);
660}
661
8d400b81
SM		 662void dlm_lockres_drop_inflight_ref(struct dlm_ctxt *dlm,
663 struct dlm_lock_resource *res)
ba2bf218
KH		 664{
665 assert_spin_locked(&res->spinlock);
666
667 BUG_ON(res->inflight_locks == 0);
8d400b81 668
ba2bf218 669 res->inflight_locks--;
ff0a522e 670
8d400b81
SM		 671 mlog(0, "%s: res %.*s, inflight--: now %u, %ps()\n", dlm->name,
672 res->lockname.len, res->lockname.name, res->inflight_locks,
673 __builtin_return_address(0));
674
ba2bf218
KH		 675 wake_up(&res->wq);
676}
677
ac4fef4d
X		 678void __dlm_lockres_grab_inflight_worker(struct dlm_ctxt *dlm,
679 struct dlm_lock_resource *res)
680{
681 assert_spin_locked(&res->spinlock);
682 res->inflight_assert_workers++;
683 mlog(0, "%s:%.*s: inflight assert worker++: now %u\n",
684 dlm->name, res->lockname.len, res->lockname.name,
685 res->inflight_assert_workers);
686}
687
ac4fef4d
X		 688static void __dlm_lockres_drop_inflight_worker(struct dlm_ctxt *dlm,
689 struct dlm_lock_resource *res)
690{
691 assert_spin_locked(&res->spinlock);
692 BUG_ON(res->inflight_assert_workers == 0);
693 res->inflight_assert_workers--;
694 mlog(0, "%s:%.*s: inflight assert worker--: now %u\n",
695 dlm->name, res->lockname.len, res->lockname.name,
696 res->inflight_assert_workers);
697}
698
699static void dlm_lockres_drop_inflight_worker(struct dlm_ctxt *dlm,
700 struct dlm_lock_resource *res)
701{
702 spin_lock(&res->spinlock);
703 __dlm_lockres_drop_inflight_worker(dlm, res);
704 spin_unlock(&res->spinlock);
705}
706
6714d8e8
KH		 707/*
708 * lookup a lock resource by name.
709 * may already exist in the hashtable.
710 * lockid is null terminated
711 *
712 * if not, allocate enough for the lockres and for
713 * the temporary structure used in doing the mastering.
714 *
715 * also, do a lookup in the dlm->master_list to see
716 * if another node has begun mastering the same lock.
717 * if so, there should be a block entry in there
718 * for this name, and we should *not* attempt to master
719 * the lock here. need to wait around for that node
720 * to assert_master (or die).
721 *
722 */
723struct dlm_lock_resource * dlm_get_lock_resource(struct dlm_ctxt *dlm,
724 const char *lockid,
3384f3df 725 int namelen,
6714d8e8
KH		 726 int flags)
727{
728 struct dlm_lock_resource *tmpres=NULL, *res=NULL;
729 struct dlm_master_list_entry *mle = NULL;
730 struct dlm_master_list_entry *alloc_mle = NULL;
731 int blocked = 0;
732 int ret, nodenum;
733 struct dlm_node_iter iter;
3384f3df 734 unsigned int hash;
6714d8e8 735 int tries = 0;
c03872f5 736 int bit, wait_on_recovery = 0;
6714d8e8
KH		 737
738 BUG_ON(!lockid);
739
a3d33291 740 hash = dlm_lockid_hash(lockid, namelen);
6714d8e8
KH		 741
742 mlog(0, "get lockres %s (len %d)\n", lockid, namelen);
743
744lookup:
745 spin_lock(&dlm->spinlock);
ba2bf218 746 tmpres = __dlm_lookup_lockres_full(dlm, lockid, namelen, hash);
6714d8e8 747 if (tmpres) {
7b791d68 748 spin_unlock(&dlm->spinlock);
ba2bf218 749 spin_lock(&tmpres->spinlock);
b1432a2a
JB		 750
751 /*
752 * Right after dlm spinlock was released, dlm_thread could have
753 * purged the lockres. Check if lockres got unhashed. If so
754 * start over.
755 */
756 if (hlist_unhashed(&tmpres->hash_node)) {
757 spin_unlock(&tmpres->spinlock);
758 dlm_lockres_put(tmpres);
759 tmpres = NULL;
760 goto lookup;
761 }
762
ff0a522e 763 /* Wait on the thread that is mastering the resource */
7b791d68
SM		 764 if (tmpres->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
765 __dlm_wait_on_lockres(tmpres);
766 BUG_ON(tmpres->owner == DLM_LOCK_RES_OWNER_UNKNOWN);
ff0a522e
SM		 767 spin_unlock(&tmpres->spinlock);
768 dlm_lockres_put(tmpres);
769 tmpres = NULL;
770 goto lookup;
7b791d68
SM		 771 }
772
ff0a522e
SM		 773 /* Wait on the resource purge to complete before continuing */
774 if (tmpres->state & DLM_LOCK_RES_DROPPING_REF) {
775 BUG_ON(tmpres->owner == dlm->node_num);
776 __dlm_wait_on_lockres_flags(tmpres,
777 DLM_LOCK_RES_DROPPING_REF);
ba2bf218
KH		 778 spin_unlock(&tmpres->spinlock);
779 dlm_lockres_put(tmpres);
780 tmpres = NULL;
781 goto lookup;
782 }
783
ff0a522e
SM		 784 /* Grab inflight ref to pin the resource */
785 dlm_lockres_grab_inflight_ref(dlm, tmpres);
786
787 spin_unlock(&tmpres->spinlock);
f57a22dd
YJ		 788 if (res) {
789 spin_lock(&dlm->track_lock);
790 if (!list_empty(&res->tracking))
791 list_del_init(&res->tracking);
792 else
793 mlog(ML_ERROR, "Resource %.*s not "
794 "on the Tracking list\n",
795 res->lockname.len,
796 res->lockname.name);
797 spin_unlock(&dlm->track_lock);
6714d8e8 798 dlm_lockres_put(res);
f57a22dd 799 }
6714d8e8
KH		 800 res = tmpres;
801 goto leave;
802 }
803
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. */
3914ed0c 808 alloc_mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
6714d8e8
KH		 809 if (!alloc_mle)
810 goto leave;
811 res = dlm_new_lockres(dlm, lockid, namelen);
812 if (!res)
813 goto leave;
814 goto lookup;
815 }
816
817 mlog(0, "no lockres found, allocated our own: %p\n", res);
818
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);
ba2bf218 825 dlm_lockres_grab_inflight_ref(dlm, res);
6714d8e8
KH		 826 spin_unlock(&res->spinlock);
827 spin_unlock(&dlm->spinlock);
828 /* lockres still marked IN_PROGRESS */
829 goto wake_waiters;
830 }
831
832 /* check master list to see if another node has started mastering it */
833 spin_lock(&dlm->master_lock);
834
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) {
ba2bf218 838 int mig;
6714d8e8
KH		 839 if (mle->type == DLM_MLE_MASTER) {
840 mlog(ML_ERROR, "master entry for nonexistent lock!\n");
841 BUG();
ba2bf218
KH		 842 }
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");
6714d8e8 859 spin_unlock(&dlm->master_lock);
6714d8e8
KH		 860 spin_unlock(&dlm->spinlock);
861
862 /* master is known, detach */
ba2bf218
KH		 863 if (!mig)
864 dlm_mle_detach_hb_events(dlm, mle);
6714d8e8
KH		 865 dlm_put_mle(mle);
866 mle = NULL;
25985edc 867 /* this is lame, but we can't wait on either
ba2bf218
KH		 868 * the mle or lockres waitqueue here */
869 if (mig)
870 msleep(100);
871 goto lookup;
6714d8e8
KH		 872 }
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);
1c084577 880 __dlm_insert_mle(dlm, mle);
c03872f5
KH		 881
882 /* still holding the dlm spinlock, check the recovery map
2bd63216 883 * to see if there are any nodes that still need to be
c03872f5
KH		 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) {
8decab3c
SM		 888 mlog(0, "%s: res %.*s, At least one node (%d) "
889 "to recover before lock mastery can begin\n",
c03872f5
KH		 890 dlm->name, namelen, (char *)lockid, bit);
891 wait_on_recovery = 1;
892 }
6714d8e8
KH		 893 }
894
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. */
899
900 /* finally add the lockres to its hash bucket */
901 __dlm_insert_lockres(dlm, res);
8d400b81 902
5760a97c
JQ		 903 /* since this lockres is new it doesn't not require the spinlock */
904 __dlm_lockres_grab_inflight_ref(dlm, res);
ba2bf218 905
6714d8e8
KH		 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. */
a2bf0477 910 dlm_get_mle_inuse(mle);
6714d8e8
KH		 911 spin_unlock(&dlm->master_lock);
912 spin_unlock(&dlm->spinlock);
913
e7e69eb3 914redo_request:
c03872f5
KH		 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)) {
8decab3c
SM		 920 mlog(0, "%s: Recovery map is not empty, but must "
921 "master $RECOVERY lock now\n", dlm->name);
c03872f5
KH		 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);
928 }
929 continue;
2bd63216 930 }
c03872f5
KH		 931
932 dlm_kick_recovery_thread(dlm);
aa087b84 933 msleep(1000);
c03872f5
KH		 934 dlm_wait_for_recovery(dlm);
935
936 spin_lock(&dlm->spinlock);
937 bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0);
938 if (bit < O2NM_MAX_NODES) {
8decab3c
SM		 939 mlog(0, "%s: res %.*s, At least one node (%d) "
940 "to recover before lock mastery can begin\n",
c03872f5
KH		 941 dlm->name, namelen, (char *)lockid, bit);
942 wait_on_recovery = 1;
943 } else
944 wait_on_recovery = 0;
945 spin_unlock(&dlm->spinlock);
b7084ab5
KH		 946
947 if (wait_on_recovery)
948 dlm_wait_for_node_recovery(dlm, bit, 10000);
c03872f5
KH		 949 }
950
6714d8e8
KH		 951 /* must wait for lock to be mastered elsewhere */
952 if (blocked)
953 goto wait;
954
6714d8e8
KH		 955 ret = -EINVAL;
956 dlm_node_iter_init(mle->vote_map, &iter);
957 while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
ba2bf218 958 ret = dlm_do_master_request(res, mle, nodenum);
6714d8e8
KH		 959 if (ret < 0)
960 mlog_errno(ret);
961 if (mle->master != O2NM_MAX_NODES) {
962 /* found a master ! */
9c6510a5
KH		 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. */
8decab3c
SM		 969 mlog(0, "%s: res %.*s, Requests only up to %u but "
970 "master is %u, keep going\n", dlm->name, namelen,
9c6510a5 971 lockid, nodenum, mle->master);
6714d8e8
KH		 972 }
973 }
974
975wait:
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) {
e7e69eb3 979 wait_on_recovery = 1;
8decab3c
SM		 980 mlog(0, "%s: res %.*s, Node map changed, redo the master "
981 "request now, blocked=%d\n", dlm->name, res->lockname.len,
6714d8e8
KH		 982 res->lockname.name, blocked);
983 if (++tries > 20) {
8decab3c
SM		 984 mlog(ML_ERROR, "%s: res %.*s, Spinning on "
985 "dlm_wait_for_lock_mastery, blocked = %d\n",
2bd63216 986 dlm->name, res->lockname.len,
6714d8e8
KH		 987 res->lockname.name, blocked);
988 dlm_print_one_lock_resource(res);
8a9343fa 989 dlm_print_one_mle(mle);
6714d8e8
KH		 990 tries = 0;
991 }
992 goto redo_request;
993 }
994
8decab3c
SM		 995 mlog(0, "%s: res %.*s, Mastered by %u\n", dlm->name, res->lockname.len,
996 res->lockname.name, res->owner);
6714d8e8
KH		 997 /* make sure we never continue without this */
998 BUG_ON(res->owner == O2NM_MAX_NODES);
999
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 */
a2bf0477 1004 dlm_put_mle_inuse(mle);
6714d8e8
KH		 1005
1006wake_waiters:
1007 spin_lock(&res->spinlock);
1008 res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
1009 spin_unlock(&res->spinlock);
1010 wake_up(&res->wq);
1011
1012leave:
1013 /* need to free the unused mle */
1014 if (alloc_mle)
1015 kmem_cache_free(dlm_mle_cache, alloc_mle);
1016
1017 return res;
1018}
1019
1020
1021#define DLM_MASTERY_TIMEOUT_MS 5000
1022
1023static 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)
1027{
1028 u8 m;
1029 int ret, bit;
1030 int map_changed, voting_done;
1031 int assert, sleep;
1032
1033recheck:
1034 ret = 0;
1035 assert = 0;
1036
1037 /* check if another node has already become the owner */
1038 spin_lock(&res->spinlock);
1039 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
9c6510a5
KH		 1040 mlog(0, "%s:%.*s: owner is suddenly %u\n", dlm->name,
1041 res->lockname.len, res->lockname.name, res->owner);
6714d8e8 1042 spin_unlock(&res->spinlock);
9c6510a5
KH		 1043 /* this will cause the master to re-assert across
1044 * the whole cluster, freeing up mles */
588e0090 1045 if (res->owner != dlm->node_num) {
ba2bf218 1046 ret = dlm_do_master_request(res, mle, res->owner);
588e0090
KH		 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;
1052 }
9c6510a5
KH		 1053 }
1054 ret = 0;
6714d8e8
KH		 1055 goto leave;
1056 }
1057 spin_unlock(&res->spinlock);
1058
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);
1065
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)) {
2bd63216 1074 mlog(0, "%s:%.*s: status change: old=%d new=%d\n",
6714d8e8
KH		 1075 dlm->name, res->lockname.len, res->lockname.name,
1076 *blocked, b);
1077 *blocked = b;
1078 }
1079 spin_unlock(&mle->spinlock);
1080 if (ret < 0) {
1081 mlog_errno(ret);
1082 goto leave;
1083 }
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;
aa852354
KH		 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);
1093 }
6714d8e8
KH		 1094 }
1095
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;
ba2bf218
KH		 1110 /* ref was grabbed in get_lock_resource
1111 * will be dropped in dlmlock_master */
6714d8e8
KH		 1112 assert = 1;
1113 sleep = 0;
1114 }
1115 /* if voting is done, but we have not received
1116 * an assert master yet, we must sleep */
1117 }
1118 }
1119
1120 spin_unlock(&mle->spinlock);
1121
1122 /* sleep if we haven't finished voting yet */
1123 if (sleep) {
1124 unsigned long timeo = msecs_to_jiffies(DLM_MASTERY_TIMEOUT_MS);
1125
1126 /*
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);
1131 */
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) {
ba2bf218
KH		 1137 mlog(0, "%s:%.*s: waiting again\n", dlm->name,
1138 res->lockname.len, res->lockname.name);
6714d8e8
KH		 1139 goto recheck;
1140 }
1141 mlog(0, "done waiting, master is %u\n", res->owner);
1142 ret = 0;
1143 goto leave;
1144 }
1145
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);
ba2bf218 1151 ret = dlm_do_assert_master(dlm, res, mle->vote_map, 0);
6714d8e8
KH		 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);
1159 }
1160 /* no longer need to restart lock mastery.
1161 * all living nodes have been contacted. */
1162 ret = 0;
1163 }
1164
1165 /* set the lockres owner */
1166 spin_lock(&res->spinlock);
ba2bf218
KH		 1167 /* mastery reference obtained either during
1168 * assert_master_handler or in get_lock_resource */
6714d8e8
KH		 1169 dlm_change_lockres_owner(dlm, res, m);
1170 spin_unlock(&res->spinlock);
1171
1172leave:
1173 return ret;
1174}
1175
1176struct dlm_bitmap_diff_iter
1177{
1178 int curnode;
1179 unsigned long *orig_bm;
1180 unsigned long *cur_bm;
1181 unsigned long diff_bm[BITS_TO_LONGS(O2NM_MAX_NODES)];
1182};
1183
1184enum dlm_node_state_change
1185{
1186 NODE_DOWN = -1,
1187 NODE_NO_CHANGE = 0,
1188 NODE_UP
1189};
1190
1191static void dlm_bitmap_diff_iter_init(struct dlm_bitmap_diff_iter *iter,
1192 unsigned long *orig_bm,
1193 unsigned long *cur_bm)
1194{
1195 unsigned long p1, p2;
1196 int i;
1197
1198 iter->curnode = -1;
1199 iter->orig_bm = orig_bm;
1200 iter->cur_bm = cur_bm;
1201
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);
1206 }
1207}
1208
1209static int dlm_bitmap_diff_iter_next(struct dlm_bitmap_diff_iter *iter,
1210 enum dlm_node_state_change *state)
1211{
1212 int bit;
1213
1214 if (iter->curnode >= O2NM_MAX_NODES)
1215 return -ENOENT;
1216
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;
1222 }
1223
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;
1229
1230 iter->curnode = bit;
1231 return bit;
1232}
1233
1234
1235static 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)
1239{
1240 struct dlm_bitmap_diff_iter bdi;
1241 enum dlm_node_state_change sc;
1242 int node;
1243 int ret = 0;
1244
1245 mlog(0, "something happened such that the "
1246 "master process may need to be restarted!\n");
1247
1248 assert_spin_locked(&mle->spinlock);
1249
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) {
e2faea4c
KH		 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);
6714d8e8
KH		 1258
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);
6714d8e8
KH		 1265 if (blocked) {
1266 int lowest = find_next_bit(mle->maybe_map,
1267 O2NM_MAX_NODES, 0);
1268
1269 /* act like it was never there */
1270 clear_bit(node, mle->maybe_map);
1271
e7e69eb3
KH		 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;
7141514b 1302 mle->mleres = res;
e7e69eb3 1303 }
6714d8e8 1304 }
6714d8e8
KH		 1305 }
1306
e7e69eb3
KH		 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);
6714d8e8
KH		 1317 }
1318 ret = -EAGAIN;
6714d8e8
KH		 1319 node = dlm_bitmap_diff_iter_next(&bdi, &sc);
1320 }
1321 return ret;
1322}
1323
1324
1325/*
1326 * DLM_MASTER_REQUEST_MSG
1327 *
1328 * returns: 0 on success,
1329 * -errno on a network error
1330 *
1331 * on error, the caller should assume the target node is "dead"
1332 *
1333 */
1334
ba2bf218
KH		 1335static int dlm_do_master_request(struct dlm_lock_resource *res,
1336 struct dlm_master_list_entry *mle, int to)
6714d8e8
KH		 1337{
1338 struct dlm_ctxt *dlm = mle->dlm;
1339 struct dlm_master_request request;
1340 int ret, response=0, resend;
1341
1342 memset(&request, 0, sizeof(request));
1343 request.node_idx = dlm->node_num;
1344
1345 BUG_ON(mle->type == DLM_MLE_MIGRATION);
1346
7141514b
SM		 1347 request.namelen = (u8)mle->mnamelen;
1348 memcpy(request.name, mle->mname, request.namelen);
6714d8e8
KH		 1349
1350again:
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();
1372 }
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;
1377 }
1378
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);
ba2bf218
KH		 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);
6714d8e8
KH		 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();
1408 }
1409 spin_unlock(&mle->spinlock);
1410 if (resend) {
1411 /* this is also totally crude */
1412 msleep(50);
1413 goto again;
1414 }
1415
1416out:
1417 return ret;
1418}
1419
1420/*
1421 * locks that can be taken here:
1422 * dlm->spinlock
1423 * res->spinlock
1424 * mle->spinlock
1425 * dlm->master_list
1426 *
1427 * if possible, TRIM THIS DOWN!!!
1428 */
d74c9803
KH		 1429int dlm_master_request_handler(struct o2net_msg *msg, u32 len, void *data,
1430 void **ret_data)
6714d8e8
KH		 1431{
1432 u8 response = DLM_MASTER_RESP_MAYBE;
1433 struct dlm_ctxt *dlm = data;
9c6510a5 1434 struct dlm_lock_resource *res = NULL;
6714d8e8
KH		 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;
a3d33291 1438 unsigned int namelen, hash;
6714d8e8
KH		 1439 int found, ret;
1440 int set_maybe;
9c6510a5 1441 int dispatch_assert = 0;
012572d4 1442 int dispatched = 0;
6714d8e8
KH		 1443
1444 if (!dlm_grab(dlm))
1445 return DLM_MASTER_RESP_NO;
1446
1447 if (!dlm_domain_fully_joined(dlm)) {
1448 response = DLM_MASTER_RESP_NO;
1449 goto send_response;
1450 }
1451
1452 name = request->name;
1453 namelen = request->namelen;
a3d33291 1454 hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 1455
1456 if (namelen > DLM_LOCKID_NAME_MAX) {
1457 response = DLM_IVBUFLEN;
1458 goto send_response;
1459 }
1460
1461way_up_top:
1462 spin_lock(&dlm->spinlock);
a3d33291 1463 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
6714d8e8
KH		 1464 if (res) {
1465 spin_unlock(&dlm->spinlock);
1466
1467 /* take care of the easy cases up front */
1468 spin_lock(&res->spinlock);
cb79662b
SE		 1469
1470 /*
1471 * Right after dlm spinlock was released, dlm_thread could have
1472 * purged the lockres. Check if lockres got unhashed. If so
1473 * start over.
1474 */
1475 if (hlist_unhashed(&res->hash_node)) {
1476 spin_unlock(&res->spinlock);
1477 dlm_lockres_put(res);
1478 goto way_up_top;
1479 }
1480
1cd04dbe
KH		 1481 if (res->state & (DLM_LOCK_RES_RECOVERING|
1482 DLM_LOCK_RES_MIGRATING)) {
6714d8e8
KH		 1483 spin_unlock(&res->spinlock);
1484 mlog(0, "returning DLM_MASTER_RESP_ERROR since res is "
1cd04dbe 1485 "being recovered/migrated\n");
6714d8e8
KH		 1486 response = DLM_MASTER_RESP_ERROR;
1487 if (mle)
1488 kmem_cache_free(dlm_mle_cache, mle);
1489 goto send_response;
1490 }
1491
1492 if (res->owner == dlm->node_num) {
8d400b81 1493 dlm_lockres_set_refmap_bit(dlm, res, request->node_idx);
6714d8e8 1494 spin_unlock(&res->spinlock);
6714d8e8
KH		 1495 response = DLM_MASTER_RESP_YES;
1496 if (mle)
1497 kmem_cache_free(dlm_mle_cache, mle);
1498
1499 /* this node is the owner.
1500 * there is some extra work that needs to
1501 * happen now. the requesting node has
1502 * caused all nodes up to this one to
1503 * create mles. this node now needs to
1504 * go back and clean those up. */
9c6510a5 1505 dispatch_assert = 1;
6714d8e8
KH		 1506 goto send_response;
1507 } else if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
1508 spin_unlock(&res->spinlock);
1509 // mlog(0, "node %u is the master\n", res->owner);
1510 response = DLM_MASTER_RESP_NO;
1511 if (mle)
1512 kmem_cache_free(dlm_mle_cache, mle);
1513 goto send_response;
1514 }
1515
1516 /* ok, there is no owner. either this node is
1517 * being blocked, or it is actively trying to
1518 * master this lock. */
1519 if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) {
1520 mlog(ML_ERROR, "lock with no owner should be "
1521 "in-progress!\n");
1522 BUG();
1523 }
1524
1525 // mlog(0, "lockres is in progress...\n");
1526 spin_lock(&dlm->master_lock);
1527 found = dlm_find_mle(dlm, &tmpmle, name, namelen);
1528 if (!found) {
1529 mlog(ML_ERROR, "no mle found for this lock!\n");
1530 BUG();
1531 }
1532 set_maybe = 1;
1533 spin_lock(&tmpmle->spinlock);
1534 if (tmpmle->type == DLM_MLE_BLOCK) {
1535 // mlog(0, "this node is waiting for "
1536 // "lockres to be mastered\n");
1537 response = DLM_MASTER_RESP_NO;
1538 } else if (tmpmle->type == DLM_MLE_MIGRATION) {
1539 mlog(0, "node %u is master, but trying to migrate to "
1540 "node %u.\n", tmpmle->master, tmpmle->new_master);
1541 if (tmpmle->master == dlm->node_num) {
6714d8e8
KH		 1542 mlog(ML_ERROR, "no owner on lockres, but this "
1543 "node is trying to migrate it to %u?!\n",
1544 tmpmle->new_master);
1545 BUG();
1546 } else {
1547 /* the real master can respond on its own */
1548 response = DLM_MASTER_RESP_NO;
1549 }
1550 } else if (tmpmle->master != DLM_LOCK_RES_OWNER_UNKNOWN) {
1551 set_maybe = 0;
9c6510a5 1552 if (tmpmle->master == dlm->node_num) {
6714d8e8 1553 response = DLM_MASTER_RESP_YES;
9c6510a5
KH		 1554 /* this node will be the owner.
1555 * go back and clean the mles on any
1556 * other nodes */
1557 dispatch_assert = 1;
8d400b81
SM		 1558 dlm_lockres_set_refmap_bit(dlm, res,
1559 request->node_idx);
9c6510a5 1560 } else
6714d8e8
KH		 1561 response = DLM_MASTER_RESP_NO;
1562 } else {
1563 // mlog(0, "this node is attempting to "
1564 // "master lockres\n");
1565 response = DLM_MASTER_RESP_MAYBE;
1566 }
1567 if (set_maybe)
1568 set_bit(request->node_idx, tmpmle->maybe_map);
1569 spin_unlock(&tmpmle->spinlock);
1570
1571 spin_unlock(&dlm->master_lock);
1572 spin_unlock(&res->spinlock);
1573
1574 /* keep the mle attached to heartbeat events */
1575 dlm_put_mle(tmpmle);
1576 if (mle)
1577 kmem_cache_free(dlm_mle_cache, mle);
1578 goto send_response;
1579 }
1580
1581 /*
1582 * lockres doesn't exist on this node
1583 * if there is an MLE_BLOCK, return NO
1584 * if there is an MLE_MASTER, return MAYBE
1585 * otherwise, add an MLE_BLOCK, return NO
1586 */
1587 spin_lock(&dlm->master_lock);
1588 found = dlm_find_mle(dlm, &tmpmle, name, namelen);
1589 if (!found) {
1590 /* this lockid has never been seen on this node yet */
1591 // mlog(0, "no mle found\n");
1592 if (!mle) {
1593 spin_unlock(&dlm->master_lock);
1594 spin_unlock(&dlm->spinlock);
1595
3914ed0c 1596 mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
6714d8e8 1597 if (!mle) {
6714d8e8 1598 response = DLM_MASTER_RESP_ERROR;
9c6510a5 1599 mlog_errno(-ENOMEM);
6714d8e8
KH		 1600 goto send_response;
1601 }
6714d8e8
KH		 1602 goto way_up_top;
1603 }
1604
1605 // mlog(0, "this is second time thru, already allocated, "
1606 // "add the block.\n");
41b8c8a1 1607 dlm_init_mle(mle, DLM_MLE_BLOCK, dlm, NULL, name, namelen);
6714d8e8 1608 set_bit(request->node_idx, mle->maybe_map);
1c084577 1609 __dlm_insert_mle(dlm, mle);
6714d8e8
KH		 1610 response = DLM_MASTER_RESP_NO;
1611 } else {
1612 // mlog(0, "mle was found\n");
1613 set_maybe = 1;
1614 spin_lock(&tmpmle->spinlock);
9c6510a5
KH		 1615 if (tmpmle->master == dlm->node_num) {
1616 mlog(ML_ERROR, "no lockres, but an mle with this node as master!\n");
1617 BUG();
1618 }
6714d8e8
KH		 1619 if (tmpmle->type == DLM_MLE_BLOCK)
1620 response = DLM_MASTER_RESP_NO;
1621 else if (tmpmle->type == DLM_MLE_MIGRATION) {
1622 mlog(0, "migration mle was found (%u->%u)\n",
1623 tmpmle->master, tmpmle->new_master);
6714d8e8
KH		 1624 /* real master can respond on its own */
1625 response = DLM_MASTER_RESP_NO;
9c6510a5
KH		 1626 } else
1627 response = DLM_MASTER_RESP_MAYBE;
6714d8e8
KH		 1628 if (set_maybe)
1629 set_bit(request->node_idx, tmpmle->maybe_map);
1630 spin_unlock(&tmpmle->spinlock);
1631 }
1632 spin_unlock(&dlm->master_lock);
1633 spin_unlock(&dlm->spinlock);
1634
1635 if (found) {
1636 /* keep the mle attached to heartbeat events */
1637 dlm_put_mle(tmpmle);
1638 }
1639send_response:
b31cfc02
SM		 1640 /*
1641 * __dlm_lookup_lockres() grabbed a reference to this lockres.
1642 * The reference is released by dlm_assert_master_worker() under
1643 * the call to dlm_dispatch_assert_master(). If
1644 * dlm_assert_master_worker() isn't called, we drop it here.
1645 */
9c6510a5
KH		 1646 if (dispatch_assert) {
1647 if (response != DLM_MASTER_RESP_YES)
1648 mlog(ML_ERROR, "invalid response %d\n", response);
1649 if (!res) {
1650 mlog(ML_ERROR, "bad lockres while trying to assert!\n");
1651 BUG();
1652 }
1653 mlog(0, "%u is the owner of %.*s, cleaning everyone else\n",
1654 dlm->node_num, res->lockname.len, res->lockname.name);
1e589581 1655 spin_lock(&res->spinlock);
2bd63216 1656 ret = dlm_dispatch_assert_master(dlm, res, 0, request->node_idx,
9c6510a5
KH		 1657 DLM_ASSERT_MASTER_MLE_CLEANUP);
1658 if (ret < 0) {
1659 mlog(ML_ERROR, "failed to dispatch assert master work\n");
1660 response = DLM_MASTER_RESP_ERROR;
b67de018 1661 spin_unlock(&res->spinlock);
b31cfc02 1662 dlm_lockres_put(res);
012572d4
JQ		 1663 } else {
1664 dispatched = 1;
1e589581 1665 __dlm_lockres_grab_inflight_worker(dlm, res);
b67de018 1666 spin_unlock(&res->spinlock);
012572d4 1667 }
b31cfc02
SM		 1668 } else {
1669 if (res)
1670 dlm_lockres_put(res);
9c6510a5
KH		 1671 }
1672
012572d4
JQ		 1673 if (!dispatched)
1674 dlm_put(dlm);
6714d8e8
KH		 1675 return response;
1676}
1677
1678/*
1679 * DLM_ASSERT_MASTER_MSG
1680 */
1681
1682
1683/*
1684 * NOTE: this can be used for debugging
1685 * can periodically run all locks owned by this node
1686 * and re-assert across the cluster...
1687 */
05488bbe
AB		 1688static int dlm_do_assert_master(struct dlm_ctxt *dlm,
1689 struct dlm_lock_resource *res,
1690 void *nodemap, u32 flags)
6714d8e8
KH		 1691{
1692 struct dlm_assert_master assert;
1693 int to, tmpret;
1694 struct dlm_node_iter iter;
1695 int ret = 0;
9c6510a5 1696 int reassert;
ba2bf218
KH		 1697 const char *lockname = res->lockname.name;
1698 unsigned int namelen = res->lockname.len;
6714d8e8
KH		 1699
1700 BUG_ON(namelen > O2NM_MAX_NAME_LEN);
f3f85464
SM		 1701
1702 spin_lock(&res->spinlock);
1703 res->state |= DLM_LOCK_RES_SETREF_INPROG;
1704 spin_unlock(&res->spinlock);
1705
9c6510a5
KH		 1706again:
1707 reassert = 0;
6714d8e8
KH		 1708
1709 /* note that if this nodemap is empty, it returns 0 */
1710 dlm_node_iter_init(nodemap, &iter);
1711 while ((to = dlm_node_iter_next(&iter)) >= 0) {
1712 int r = 0;
a9ee4c8a
KH		 1713 struct dlm_master_list_entry *mle = NULL;
1714
6714d8e8
KH		 1715 mlog(0, "sending assert master to %d (%.*s)\n", to,
1716 namelen, lockname);
1717 memset(&assert, 0, sizeof(assert));
1718 assert.node_idx = dlm->node_num;
1719 assert.namelen = namelen;
1720 memcpy(assert.name, lockname, namelen);
1721 assert.flags = cpu_to_be32(flags);
1722
1723 tmpret = o2net_send_message(DLM_ASSERT_MASTER_MSG, dlm->key,
1724 &assert, sizeof(assert), to, &r);
1725 if (tmpret < 0) {
a5196ec5
WW		 1726 mlog(ML_ERROR, "Error %d when sending message %u (key "
1727 "0x%x) to node %u\n", tmpret,
1728 DLM_ASSERT_MASTER_MSG, dlm->key, to);
6714d8e8 1729 if (!dlm_is_host_down(tmpret)) {
3b3b84a8 1730 mlog(ML_ERROR, "unhandled error=%d!\n", tmpret);
6714d8e8
KH		 1731 BUG();
1732 }
1733 /* a node died. finish out the rest of the nodes. */
3b3b84a8 1734 mlog(0, "link to %d went down!\n", to);
6714d8e8
KH		 1735 /* any nonzero status return will do */
1736 ret = tmpret;
ba2bf218 1737 r = 0;
6714d8e8
KH		 1738 } else if (r < 0) {
1739 /* ok, something horribly messed. kill thyself. */
1740 mlog(ML_ERROR,"during assert master of %.*s to %u, "
1741 "got %d.\n", namelen, lockname, to, r);
a9ee4c8a
KH		 1742 spin_lock(&dlm->spinlock);
1743 spin_lock(&dlm->master_lock);
1744 if (dlm_find_mle(dlm, &mle, (char *)lockname,
1745 namelen)) {
1746 dlm_print_one_mle(mle);
1747 __dlm_put_mle(mle);
1748 }
1749 spin_unlock(&dlm->master_lock);
1750 spin_unlock(&dlm->spinlock);
6714d8e8 1751 BUG();
ba2bf218
KH		 1752 }
1753
1754 if (r & DLM_ASSERT_RESPONSE_REASSERT &&
1755 !(r & DLM_ASSERT_RESPONSE_MASTERY_REF)) {
1756 mlog(ML_ERROR, "%.*s: very strange, "
1757 "master MLE but no lockres on %u\n",
1758 namelen, lockname, to);
1759 }
1760
1761 if (r & DLM_ASSERT_RESPONSE_REASSERT) {
9c6510a5 1762 mlog(0, "%.*s: node %u create mles on other "
2bd63216 1763 "nodes and requests a re-assert\n",
9c6510a5
KH		 1764 namelen, lockname, to);
1765 reassert = 1;
6714d8e8 1766 }
ba2bf218
KH		 1767 if (r & DLM_ASSERT_RESPONSE_MASTERY_REF) {
1768 mlog(0, "%.*s: node %u has a reference to this "
1769 "lockres, set the bit in the refmap\n",
1770 namelen, lockname, to);
1771 spin_lock(&res->spinlock);
8d400b81 1772 dlm_lockres_set_refmap_bit(dlm, res, to);
ba2bf218
KH		 1773 spin_unlock(&res->spinlock);
1774 }
6714d8e8
KH		 1775 }
1776
9c6510a5
KH		 1777 if (reassert)
1778 goto again;
1779
f3f85464
SM		 1780 spin_lock(&res->spinlock);
1781 res->state &= ~DLM_LOCK_RES_SETREF_INPROG;
1782 spin_unlock(&res->spinlock);
1783 wake_up(&res->wq);
1784
6714d8e8
KH		 1785 return ret;
1786}
1787
1788/*
1789 * locks that can be taken here:
1790 * dlm->spinlock
1791 * res->spinlock
1792 * mle->spinlock
1793 * dlm->master_list
1794 *
1795 * if possible, TRIM THIS DOWN!!!
1796 */
d74c9803
KH		 1797int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data,
1798 void **ret_data)
6714d8e8
KH		 1799{
1800 struct dlm_ctxt *dlm = data;
1801 struct dlm_master_list_entry *mle = NULL;
1802 struct dlm_assert_master *assert = (struct dlm_assert_master *)msg->buf;
1803 struct dlm_lock_resource *res = NULL;
1804 char *name;
a3d33291 1805 unsigned int namelen, hash;
6714d8e8 1806 u32 flags;
ba2bf218 1807 int master_request = 0, have_lockres_ref = 0;
9c6510a5 1808 int ret = 0;
6714d8e8
KH		 1809
1810 if (!dlm_grab(dlm))
1811 return 0;
1812
1813 name = assert->name;
1814 namelen = assert->namelen;
a3d33291 1815 hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 1816 flags = be32_to_cpu(assert->flags);
1817
1818 if (namelen > DLM_LOCKID_NAME_MAX) {
1819 mlog(ML_ERROR, "Invalid name length!");
1820 goto done;
1821 }
1822
1823 spin_lock(&dlm->spinlock);
1824
1825 if (flags)
1826 mlog(0, "assert_master with flags: %u\n", flags);
1827
1828 /* find the MLE */
1829 spin_lock(&dlm->master_lock);
1830 if (!dlm_find_mle(dlm, &mle, name, namelen)) {
1831 /* not an error, could be master just re-asserting */
1832 mlog(0, "just got an assert_master from %u, but no "
1833 "MLE for it! (%.*s)\n", assert->node_idx,
1834 namelen, name);
1835 } else {
1836 int bit = find_next_bit (mle->maybe_map, O2NM_MAX_NODES, 0);
1837 if (bit >= O2NM_MAX_NODES) {
1838 /* not necessarily an error, though less likely.
1839 * could be master just re-asserting. */
aa852354 1840 mlog(0, "no bits set in the maybe_map, but %u "
6714d8e8
KH		 1841 "is asserting! (%.*s)\n", assert->node_idx,
1842 namelen, name);
1843 } else if (bit != assert->node_idx) {
1844 if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) {
1845 mlog(0, "master %u was found, %u should "
1846 "back off\n", assert->node_idx, bit);
1847 } else {
1848 /* with the fix for bug 569, a higher node
1849 * number winning the mastery will respond
1850 * YES to mastery requests, but this node
1851 * had no way of knowing. let it pass. */
aa852354 1852 mlog(0, "%u is the lowest node, "
6714d8e8
KH		 1853 "%u is asserting. (%.*s) %u must "
1854 "have begun after %u won.\n", bit,
1855 assert->node_idx, namelen, name, bit,
1856 assert->node_idx);
1857 }
1858 }
2d1a868c
KH		 1859 if (mle->type == DLM_MLE_MIGRATION) {
1860 if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) {
1861 mlog(0, "%s:%.*s: got cleanup assert"
1862 " from %u for migration\n",
1863 dlm->name, namelen, name,
1864 assert->node_idx);
1865 } else if (!(flags & DLM_ASSERT_MASTER_FINISH_MIGRATION)) {
1866 mlog(0, "%s:%.*s: got unrelated assert"
1867 " from %u for migration, ignoring\n",
1868 dlm->name, namelen, name,
1869 assert->node_idx);
1870 __dlm_put_mle(mle);
1871 spin_unlock(&dlm->master_lock);
1872 spin_unlock(&dlm->spinlock);
1873 goto done;
2bd63216 1874 }
2d1a868c 1875 }
6714d8e8
KH		 1876 }
1877 spin_unlock(&dlm->master_lock);
1878
1879 /* ok everything checks out with the MLE
1880 * now check to see if there is a lockres */
a3d33291 1881 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
6714d8e8
KH		 1882 if (res) {
1883 spin_lock(&res->spinlock);
1884 if (res->state & DLM_LOCK_RES_RECOVERING) {
1885 mlog(ML_ERROR, "%u asserting but %.*s is "
1886 "RECOVERING!\n", assert->node_idx, namelen, name);
1887 goto kill;
1888 }
1889 if (!mle) {
dc2ed195
KH		 1890 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN &&
1891 res->owner != assert->node_idx) {
53ecd25e
SM		 1892 mlog(ML_ERROR, "DIE! Mastery assert from %u, "
1893 "but current owner is %u! (%.*s)\n",
1894 assert->node_idx, res->owner, namelen,
1895 name);
1896 __dlm_print_one_lock_resource(res);
1897 BUG();
6714d8e8
KH		 1898 }
1899 } else if (mle->type != DLM_MLE_MIGRATION) {
1900 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
1901 /* owner is just re-asserting */
1902 if (res->owner == assert->node_idx) {
1903 mlog(0, "owner %u re-asserting on "
1904 "lock %.*s\n", assert->node_idx,
1905 namelen, name);
1906 goto ok;
1907 }
1908 mlog(ML_ERROR, "got assert_master from "
1909 "node %u, but %u is the owner! "
1910 "(%.*s)\n", assert->node_idx,
1911 res->owner, namelen, name);
1912 goto kill;
1913 }
1914 if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) {
1915 mlog(ML_ERROR, "got assert from %u, but lock "
1916 "with no owner should be "
1917 "in-progress! (%.*s)\n",
1918 assert->node_idx,
1919 namelen, name);
1920 goto kill;
1921 }
1922 } else /* mle->type == DLM_MLE_MIGRATION */ {
1923 /* should only be getting an assert from new master */
1924 if (assert->node_idx != mle->new_master) {
1925 mlog(ML_ERROR, "got assert from %u, but "
1926 "new master is %u, and old master "
1927 "was %u (%.*s)\n",
1928 assert->node_idx, mle->new_master,
1929 mle->master, namelen, name);
1930 goto kill;
1931 }
1932
1933 }
1934ok:
1935 spin_unlock(&res->spinlock);
1936 }
6714d8e8
KH		 1937
1938 // mlog(0, "woo! got an assert_master from node %u!\n",
1939 // assert->node_idx);
1940 if (mle) {
9c6510a5
KH		 1941 int extra_ref = 0;
1942 int nn = -1;
a2bf0477 1943 int rr, err = 0;
2bd63216 1944
6714d8e8 1945 spin_lock(&mle->spinlock);
9c6510a5
KH		 1946 if (mle->type == DLM_MLE_BLOCK || mle->type == DLM_MLE_MIGRATION)
1947 extra_ref = 1;
1948 else {
1949 /* MASTER mle: if any bits set in the response map
1950 * then the calling node needs to re-assert to clear
1951 * up nodes that this node contacted */
2bd63216 1952 while ((nn = find_next_bit (mle->response_map, O2NM_MAX_NODES,
9c6510a5 1953 nn+1)) < O2NM_MAX_NODES) {
728b9805 1954 if (nn != dlm->node_num && nn != assert->node_idx) {
9c6510a5 1955 master_request = 1;
728b9805
JB		 1956 break;
1957 }
9c6510a5
KH		 1958 }
1959 }
6714d8e8
KH		 1960 mle->master = assert->node_idx;
1961 atomic_set(&mle->woken, 1);
1962 wake_up(&mle->wq);
1963 spin_unlock(&mle->spinlock);
1964
a2bf0477 1965 if (res) {
a6fa3640 1966 int wake = 0;
6714d8e8 1967 spin_lock(&res->spinlock);
a2bf0477
KH		 1968 if (mle->type == DLM_MLE_MIGRATION) {
1969 mlog(0, "finishing off migration of lockres %.*s, "
1970 "from %u to %u\n",
1971 res->lockname.len, res->lockname.name,
1972 dlm->node_num, mle->new_master);
1973 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 1974 wake = 1;
a2bf0477
KH		 1975 dlm_change_lockres_owner(dlm, res, mle->new_master);
1976 BUG_ON(res->state & DLM_LOCK_RES_DIRTY);
1977 } else {
1978 dlm_change_lockres_owner(dlm, res, mle->master);
1979 }
6714d8e8 1980 spin_unlock(&res->spinlock);
ba2bf218 1981 have_lockres_ref = 1;
a6fa3640
KH		 1982 if (wake)
1983 wake_up(&res->wq);
6714d8e8 1984 }
a2bf0477
KH		 1985
1986 /* master is known, detach if not already detached.
1987 * ensures that only one assert_master call will happen
1988 * on this mle. */
a2bf0477
KH		 1989 spin_lock(&dlm->master_lock);
1990
1991 rr = atomic_read(&mle->mle_refs.refcount);
1992 if (mle->inuse > 0) {
1993 if (extra_ref && rr < 3)
1994 err = 1;
1995 else if (!extra_ref && rr < 2)
1996 err = 1;
1997 } else {
1998 if (extra_ref && rr < 2)
1999 err = 1;
2000 else if (!extra_ref && rr < 1)
2001 err = 1;
2002 }
2003 if (err) {
2004 mlog(ML_ERROR, "%s:%.*s: got assert master from %u "
2005 "that will mess up this node, refs=%d, extra=%d, "
2006 "inuse=%d\n", dlm->name, namelen, name,
2007 assert->node_idx, rr, extra_ref, mle->inuse);
2008 dlm_print_one_mle(mle);
2009 }
1c084577 2010 __dlm_unlink_mle(dlm, mle);
a2bf0477
KH		 2011 __dlm_mle_detach_hb_events(dlm, mle);
2012 __dlm_put_mle(mle);
6714d8e8
KH		 2013 if (extra_ref) {
2014 /* the assert master message now balances the extra
2015 * ref given by the master / migration request message.
2016 * if this is the last put, it will be removed
2017 * from the list. */
a2bf0477
KH		 2018 __dlm_put_mle(mle);
2019 }
2020 spin_unlock(&dlm->master_lock);
a2bf0477
KH		 2021 } else if (res) {
2022 if (res->owner != assert->node_idx) {
2023 mlog(0, "assert_master from %u, but current "
2024 "owner is %u (%.*s), no mle\n", assert->node_idx,
2025 res->owner, namelen, name);
6714d8e8
KH		 2026 }
2027 }
14741472 2028 spin_unlock(&dlm->spinlock);
6714d8e8
KH		 2029
2030done:
9c6510a5 2031 ret = 0;
3b8118cf
KH		 2032 if (res) {
2033 spin_lock(&res->spinlock);
2034 res->state |= DLM_LOCK_RES_SETREF_INPROG;
2035 spin_unlock(&res->spinlock);
2036 *ret_data = (void *)res;
2037 }
6714d8e8 2038 dlm_put(dlm);
9c6510a5
KH		 2039 if (master_request) {
2040 mlog(0, "need to tell master to reassert\n");
ba2bf218
KH		 2041 /* positive. negative would shoot down the node. */
2042 ret |= DLM_ASSERT_RESPONSE_REASSERT;
2043 if (!have_lockres_ref) {
2044 mlog(ML_ERROR, "strange, got assert from %u, MASTER "
2045 "mle present here for %s:%.*s, but no lockres!\n",
2046 assert->node_idx, dlm->name, namelen, name);
2047 }
2048 }
2049 if (have_lockres_ref) {
2050 /* let the master know we have a reference to the lockres */
2051 ret |= DLM_ASSERT_RESPONSE_MASTERY_REF;
2052 mlog(0, "%s:%.*s: got assert from %u, need a ref\n",
2053 dlm->name, namelen, name, assert->node_idx);
9c6510a5
KH		 2054 }
2055 return ret;
6714d8e8
KH		 2056
2057kill:
2058 /* kill the caller! */
a9ee4c8a
KH		 2059 mlog(ML_ERROR, "Bad message received from another node. Dumping state "
2060 "and killing the other node now! This node is OK and can continue.\n");
2061 __dlm_print_one_lock_resource(res);
6714d8e8 2062 spin_unlock(&res->spinlock);
55dacd22 2063 spin_lock(&dlm->master_lock);
2064 if (mle)
2065 __dlm_put_mle(mle);
2066 spin_unlock(&dlm->master_lock);
6714d8e8 2067 spin_unlock(&dlm->spinlock);
2bd63216 2068 *ret_data = (void *)res;
6714d8e8
KH		 2069 dlm_put(dlm);
2070 return -EINVAL;
2071}
2072
3b8118cf
KH		 2073void dlm_assert_master_post_handler(int status, void *data, void *ret_data)
2074{
2075 struct dlm_lock_resource *res = (struct dlm_lock_resource *)ret_data;
2076
2077 if (ret_data) {
2078 spin_lock(&res->spinlock);
2079 res->state &= ~DLM_LOCK_RES_SETREF_INPROG;
2080 spin_unlock(&res->spinlock);
2081 wake_up(&res->wq);
2082 dlm_lockres_put(res);
2083 }
2084 return;
2085}
2086
6714d8e8
KH		 2087int dlm_dispatch_assert_master(struct dlm_ctxt *dlm,
2088 struct dlm_lock_resource *res,
2089 int ignore_higher, u8 request_from, u32 flags)
2090{
2091 struct dlm_work_item *item;
b24ae0b5 2092 item = kzalloc(sizeof(*item), GFP_ATOMIC);
6714d8e8
KH		 2093 if (!item)
2094 return -ENOMEM;
2095
2096
2097 /* queue up work for dlm_assert_master_worker */
6714d8e8
KH		 2098 dlm_init_work_item(dlm, item, dlm_assert_master_worker, NULL);
2099 item->u.am.lockres = res; /* already have a ref */
2100 /* can optionally ignore node numbers higher than this node */
2101 item->u.am.ignore_higher = ignore_higher;
2102 item->u.am.request_from = request_from;
2103 item->u.am.flags = flags;
2104
2bd63216
SM		 2105 if (ignore_higher)
2106 mlog(0, "IGNORE HIGHER: %.*s\n", res->lockname.len,
9c6510a5 2107 res->lockname.name);
2bd63216 2108
6714d8e8
KH		 2109 spin_lock(&dlm->work_lock);
2110 list_add_tail(&item->list, &dlm->work_list);
2111 spin_unlock(&dlm->work_lock);
2112
3156d267 2113 queue_work(dlm->dlm_worker, &dlm->dispatched_work);
6714d8e8
KH		 2114 return 0;
2115}
2116
2117static void dlm_assert_master_worker(struct dlm_work_item *item, void *data)
2118{
2119 struct dlm_ctxt *dlm = data;
2120 int ret = 0;
2121 struct dlm_lock_resource *res;
2122 unsigned long nodemap[BITS_TO_LONGS(O2NM_MAX_NODES)];
2123 int ignore_higher;
2124 int bit;
2125 u8 request_from;
2126 u32 flags;
2127
2128 dlm = item->dlm;
2129 res = item->u.am.lockres;
2130 ignore_higher = item->u.am.ignore_higher;
2131 request_from = item->u.am.request_from;
2132 flags = item->u.am.flags;
2133
2134 spin_lock(&dlm->spinlock);
2135 memcpy(nodemap, dlm->domain_map, sizeof(nodemap));
2136 spin_unlock(&dlm->spinlock);
2137
2138 clear_bit(dlm->node_num, nodemap);
2139 if (ignore_higher) {
2140 /* if is this just to clear up mles for nodes below
2141 * this node, do not send the message to the original
2142 * caller or any node number higher than this */
2143 clear_bit(request_from, nodemap);
2144 bit = dlm->node_num;
2145 while (1) {
2146 bit = find_next_bit(nodemap, O2NM_MAX_NODES,
2147 bit+1);
2148 if (bit >= O2NM_MAX_NODES)
2149 break;
2150 clear_bit(bit, nodemap);
2151 }
2152 }
2153
36407488
KH		 2154 /*
2155 * If we're migrating this lock to someone else, we are no
2156 * longer allowed to assert out own mastery. OTOH, we need to
2157 * prevent migration from starting while we're still asserting
2158 * our dominance. The reserved ast delays migration.
2159 */
2160 spin_lock(&res->spinlock);
2161 if (res->state & DLM_LOCK_RES_MIGRATING) {
2162 mlog(0, "Someone asked us to assert mastery, but we're "
2163 "in the middle of migration. Skipping assert, "
2164 "the new master will handle that.\n");
2165 spin_unlock(&res->spinlock);
2166 goto put;
2167 } else
2168 __dlm_lockres_reserve_ast(res);
2169 spin_unlock(&res->spinlock);
2170
6714d8e8
KH		 2171 /* this call now finishes out the nodemap
2172 * even if one or more nodes die */
2173 mlog(0, "worker about to master %.*s here, this=%u\n",
2174 res->lockname.len, res->lockname.name, dlm->node_num);
ba2bf218 2175 ret = dlm_do_assert_master(dlm, res, nodemap, flags);
6714d8e8
KH		 2176 if (ret < 0) {
2177 /* no need to restart, we are done */
3b3b84a8
KH		 2178 if (!dlm_is_host_down(ret))
2179 mlog_errno(ret);
6714d8e8
KH		 2180 }
2181
36407488
KH		 2182 /* Ok, we've asserted ourselves. Let's let migration start. */
2183 dlm_lockres_release_ast(dlm, res);
2184
2185put:
ac4fef4d
X		 2186 dlm_lockres_drop_inflight_worker(dlm, res);
2187
6714d8e8
KH		 2188 dlm_lockres_put(res);
2189
2190 mlog(0, "finished with dlm_assert_master_worker\n");
2191}
2192
c03872f5
KH		 2193/* SPECIAL CASE for the $RECOVERY lock used by the recovery thread.
2194 * We cannot wait for node recovery to complete to begin mastering this
2195 * lockres because this lockres is used to kick off recovery! ;-)
2196 * So, do a pre-check on all living nodes to see if any of those nodes
2197 * think that $RECOVERY is currently mastered by a dead node. If so,
2198 * we wait a short time to allow that node to get notified by its own
2199 * heartbeat stack, then check again. All $RECOVERY lock resources
2bd63216 2200 * mastered by dead nodes are purged when the hearbeat callback is
c03872f5
KH		 2201 * fired, so we can know for sure that it is safe to continue once
2202 * the node returns a live node or no node. */
2203static int dlm_pre_master_reco_lockres(struct dlm_ctxt *dlm,
2204 struct dlm_lock_resource *res)
2205{
2206 struct dlm_node_iter iter;
2207 int nodenum;
2208 int ret = 0;
2209 u8 master = DLM_LOCK_RES_OWNER_UNKNOWN;
2210
2211 spin_lock(&dlm->spinlock);
2212 dlm_node_iter_init(dlm->domain_map, &iter);
2213 spin_unlock(&dlm->spinlock);
2214
2215 while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2216 /* do not send to self */
2217 if (nodenum == dlm->node_num)
2218 continue;
2219 ret = dlm_do_master_requery(dlm, res, nodenum, &master);
2220 if (ret < 0) {
2221 mlog_errno(ret);
2222 if (!dlm_is_host_down(ret))
2223 BUG();
2224 /* host is down, so answer for that node would be
2225 * DLM_LOCK_RES_OWNER_UNKNOWN. continue. */
f42a100b 2226 ret = 0;
c03872f5
KH		 2227 }
2228
2229 if (master != DLM_LOCK_RES_OWNER_UNKNOWN) {
2230 /* check to see if this master is in the recovery map */
2231 spin_lock(&dlm->spinlock);
2232 if (test_bit(master, dlm->recovery_map)) {
2233 mlog(ML_NOTICE, "%s: node %u has not seen "
2234 "node %u go down yet, and thinks the "
2235 "dead node is mastering the recovery "
2236 "lock. must wait.\n", dlm->name,
2237 nodenum, master);
2238 ret = -EAGAIN;
2239 }
2240 spin_unlock(&dlm->spinlock);
2bd63216 2241 mlog(0, "%s: reco lock master is %u\n", dlm->name,
c03872f5
KH		 2242 master);
2243 break;
2244 }
2245 }
2246 return ret;
2247}
2248
ba2bf218
KH		 2249/*
2250 * DLM_DEREF_LOCKRES_MSG
2251 */
2252
2253int dlm_drop_lockres_ref(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
2254{
2255 struct dlm_deref_lockres deref;
2256 int ret = 0, r;
2257 const char *lockname;
2258 unsigned int namelen;
2259
2260 lockname = res->lockname.name;
2261 namelen = res->lockname.len;
2262 BUG_ON(namelen > O2NM_MAX_NAME_LEN);
2263
ba2bf218
KH		 2264 memset(&deref, 0, sizeof(deref));
2265 deref.node_idx = dlm->node_num;
2266 deref.namelen = namelen;
2267 memcpy(deref.name, lockname, namelen);
2268
2269 ret = o2net_send_message(DLM_DEREF_LOCKRES_MSG, dlm->key,
2270 &deref, sizeof(deref), res->owner, &r);
2271 if (ret < 0)
8decab3c
SM		 2272 mlog(ML_ERROR, "%s: res %.*s, error %d send DEREF to node %u\n",
2273 dlm->name, namelen, lockname, ret, res->owner);
ba2bf218
KH		 2274 else if (r < 0) {
2275 /* BAD. other node says I did not have a ref. */
8decab3c
SM		 2276 mlog(ML_ERROR, "%s: res %.*s, DEREF to node %u got %d\n",
2277 dlm->name, namelen, lockname, res->owner, r);
ba2bf218
KH		 2278 dlm_print_one_lock_resource(res);
2279 BUG();
2280 }
2281 return ret;
2282}
2283
d74c9803
KH		 2284int dlm_deref_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
2285 void **ret_data)
ba2bf218
KH		 2286{
2287 struct dlm_ctxt *dlm = data;
2288 struct dlm_deref_lockres *deref = (struct dlm_deref_lockres *)msg->buf;
2289 struct dlm_lock_resource *res = NULL;
2290 char *name;
2291 unsigned int namelen;
2292 int ret = -EINVAL;
2293 u8 node;
2294 unsigned int hash;
f3f85464
SM		 2295 struct dlm_work_item *item;
2296 int cleared = 0;
2297 int dispatch = 0;
ba2bf218
KH		 2298
2299 if (!dlm_grab(dlm))
2300 return 0;
2301
2302 name = deref->name;
2303 namelen = deref->namelen;
2304 node = deref->node_idx;
2305
2306 if (namelen > DLM_LOCKID_NAME_MAX) {
2307 mlog(ML_ERROR, "Invalid name length!");
2308 goto done;
2309 }
2310 if (deref->node_idx >= O2NM_MAX_NODES) {
2311 mlog(ML_ERROR, "Invalid node number: %u\n", node);
2312 goto done;
2313 }
2314
2315 hash = dlm_lockid_hash(name, namelen);
2316
2317 spin_lock(&dlm->spinlock);
2318 res = __dlm_lookup_lockres_full(dlm, name, namelen, hash);
2319 if (!res) {
2320 spin_unlock(&dlm->spinlock);
2321 mlog(ML_ERROR, "%s:%.*s: bad lockres name\n",
2322 dlm->name, namelen, name);
2323 goto done;
2324 }
2325 spin_unlock(&dlm->spinlock);
2326
2327 spin_lock(&res->spinlock);
f3f85464
SM		 2328 if (res->state & DLM_LOCK_RES_SETREF_INPROG)
2329 dispatch = 1;
2330 else {
2331 BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF);
2332 if (test_bit(node, res->refmap)) {
8d400b81 2333 dlm_lockres_clear_refmap_bit(dlm, res, node);
f3f85464
SM		 2334 cleared = 1;
2335 }
ba2bf218
KH		 2336 }
2337 spin_unlock(&res->spinlock);
2338
f3f85464
SM		 2339 if (!dispatch) {
2340 if (cleared)
2341 dlm_lockres_calc_usage(dlm, res);
2342 else {
2343 mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref "
2344 "but it is already dropped!\n", dlm->name,
2345 res->lockname.len, res->lockname.name, node);
2af37ce8 2346 dlm_print_one_lock_resource(res);
f3f85464
SM		 2347 }
2348 ret = 0;
2349 goto done;
2350 }
2351
2352 item = kzalloc(sizeof(*item), GFP_NOFS);
2353 if (!item) {
2354 ret = -ENOMEM;
2355 mlog_errno(ret);
2356 goto done;
2357 }
2358
2359 dlm_init_work_item(dlm, item, dlm_deref_lockres_worker, NULL);
2360 item->u.dl.deref_res = res;
2361 item->u.dl.deref_node = node;
2362
2363 spin_lock(&dlm->work_lock);
2364 list_add_tail(&item->list, &dlm->work_list);
2365 spin_unlock(&dlm->work_lock);
2366
2367 queue_work(dlm->dlm_worker, &dlm->dispatched_work);
2368 return 0;
2369
ba2bf218
KH		 2370done:
2371 if (res)
2372 dlm_lockres_put(res);
2373 dlm_put(dlm);
f3f85464 2374
ba2bf218
KH		 2375 return ret;
2376}
2377
f3f85464
SM		 2378static void dlm_deref_lockres_worker(struct dlm_work_item *item, void *data)
2379{
2380 struct dlm_ctxt *dlm;
2381 struct dlm_lock_resource *res;
2382 u8 node;
2383 u8 cleared = 0;
2384
2385 dlm = item->dlm;
2386 res = item->u.dl.deref_res;
2387 node = item->u.dl.deref_node;
2388
2389 spin_lock(&res->spinlock);
2390 BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF);
b5560143 2391 __dlm_wait_on_lockres_flags(res, DLM_LOCK_RES_SETREF_INPROG);
f3f85464 2392 if (test_bit(node, res->refmap)) {
8d400b81 2393 dlm_lockres_clear_refmap_bit(dlm, res, node);
f3f85464
SM		 2394 cleared = 1;
2395 }
2396 spin_unlock(&res->spinlock);
2397
2398 if (cleared) {
2399 mlog(0, "%s:%.*s node %u ref dropped in dispatch\n",
2400 dlm->name, res->lockname.len, res->lockname.name, node);
2401 dlm_lockres_calc_usage(dlm, res);
2402 } else {
2403 mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref "
2404 "but it is already dropped!\n", dlm->name,
2405 res->lockname.len, res->lockname.name, node);
2af37ce8 2406 dlm_print_one_lock_resource(res);
f3f85464
SM		 2407 }
2408
2409 dlm_lockres_put(res);
2410}
2411
9f62e960
SM		 2412/*
2413 * A migrateable resource is one that is :
2414 * 1. locally mastered, and,
2415 * 2. zero local locks, and,
2416 * 3. one or more non-local locks, or, one or more references
2417 * Returns 1 if yes, 0 if not.
2f5bf1f2
SM		 2418 */
2419static int dlm_is_lockres_migrateable(struct dlm_ctxt *dlm,
9f62e960 2420 struct dlm_lock_resource *res)
2f5bf1f2 2421{
9f62e960
SM		 2422 enum dlm_lockres_list idx;
2423 int nonlocal = 0, node_ref;
800deef3 2424 struct list_head *queue;
2f5bf1f2 2425 struct dlm_lock *lock;
9f62e960 2426 u64 cookie;
2f5bf1f2
SM		 2427
2428 assert_spin_locked(&res->spinlock);
2429
fae477b6
X		 2430 /* delay migration when the lockres is in MIGRATING state */
2431 if (res->state & DLM_LOCK_RES_MIGRATING)
2432 return 0;
2433
bba1cb17
TS		 2434 /* delay migration when the lockres is in RECOCERING state */
2435 if (res->state & DLM_LOCK_RES_RECOVERING)
2436 return 0;
2437
9f62e960
SM		 2438 if (res->owner != dlm->node_num)
2439 return 0;
2f5bf1f2 2440
9f62e960
SM		 2441 for (idx = DLM_GRANTED_LIST; idx <= DLM_BLOCKED_LIST; idx++) {
2442 queue = dlm_list_idx_to_ptr(res, idx);
800deef3 2443 list_for_each_entry(lock, queue, list) {
9f62e960
SM		 2444 if (lock->ml.node != dlm->node_num) {
2445 nonlocal++;
2446 continue;
2f5bf1f2 2447 }
9f62e960
SM		 2448 cookie = be64_to_cpu(lock->ml.cookie);
2449 mlog(0, "%s: Not migrateable res %.*s, lock %u:%llu on "
2450 "%s list\n", dlm->name, res->lockname.len,
2451 res->lockname.name,
2452 dlm_get_lock_cookie_node(cookie),
2453 dlm_get_lock_cookie_seq(cookie),
2454 dlm_list_in_text(idx));
2455 return 0;
2f5bf1f2 2456 }
2f5bf1f2
SM		 2457 }
2458
9f62e960
SM		 2459 if (!nonlocal) {
2460 node_ref = find_next_bit(res->refmap, O2NM_MAX_NODES, 0);
2461 if (node_ref >= O2NM_MAX_NODES)
2462 return 0;
2463 }
388c4bcb 2464
9f62e960
SM		 2465 mlog(0, "%s: res %.*s, Migrateable\n", dlm->name, res->lockname.len,
2466 res->lockname.name);
2f5bf1f2 2467
9f62e960 2468 return 1;
2f5bf1f2 2469}
6714d8e8
KH		 2470
2471/*
2472 * DLM_MIGRATE_LOCKRES
2473 */
2474
2475
faf0ec9f 2476static int dlm_migrate_lockres(struct dlm_ctxt *dlm,
66effd3c 2477 struct dlm_lock_resource *res, u8 target)
6714d8e8
KH		 2478{
2479 struct dlm_master_list_entry *mle = NULL;
2480 struct dlm_master_list_entry *oldmle = NULL;
2481 struct dlm_migratable_lockres *mres = NULL;
2f5bf1f2 2482 int ret = 0;
6714d8e8
KH		 2483 const char *name;
2484 unsigned int namelen;
2485 int mle_added = 0;
2f5bf1f2 2486 int wake = 0;
6714d8e8
KH		 2487
2488 if (!dlm_grab(dlm))
2489 return -EINVAL;
2490
66effd3c
SM		 2491 BUG_ON(target == O2NM_MAX_NODES);
2492
6714d8e8
KH		 2493 name = res->lockname.name;
2494 namelen = res->lockname.len;
2495
66effd3c
SM		 2496 mlog(0, "%s: Migrating %.*s to node %u\n", dlm->name, namelen, name,
2497 target);
6714d8e8 2498
66effd3c 2499 /* preallocate up front. if this fails, abort */
6714d8e8 2500 ret = -ENOMEM;
ad8100e0 2501 mres = (struct dlm_migratable_lockres *) __get_free_page(GFP_NOFS);
6714d8e8
KH		 2502 if (!mres) {
2503 mlog_errno(ret);
2504 goto leave;
2505 }
2506
3914ed0c 2507 mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
6714d8e8
KH		 2508 if (!mle) {
2509 mlog_errno(ret);
2510 goto leave;
2511 }
2512 ret = 0;
2513
6714d8e8
KH		 2514 /*
2515 * clear any existing master requests and
2516 * add the migration mle to the list
2517 */
66effd3c 2518 spin_lock(&dlm->spinlock);
6714d8e8
KH		 2519 spin_lock(&dlm->master_lock);
2520 ret = dlm_add_migration_mle(dlm, res, mle, &oldmle, name,
2521 namelen, target, dlm->node_num);
2522 spin_unlock(&dlm->master_lock);
2523 spin_unlock(&dlm->spinlock);
2524
2525 if (ret == -EEXIST) {
2526 mlog(0, "another process is already migrating it\n");
2527 goto fail;
2528 }
2529 mle_added = 1;
2530
2531 /*
2532 * set the MIGRATING flag and flush asts
2533 * if we fail after this we need to re-dirty the lockres
2534 */
2535 if (dlm_mark_lockres_migrating(dlm, res, target) < 0) {
2536 mlog(ML_ERROR, "tried to migrate %.*s to %u, but "
2537 "the target went down.\n", res->lockname.len,
2538 res->lockname.name, target);
2539 spin_lock(&res->spinlock);
2540 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 2541 wake = 1;
6714d8e8
KH		 2542 spin_unlock(&res->spinlock);
2543 ret = -EINVAL;
2544 }
2545
2546fail:
2547 if (oldmle) {
2548 /* master is known, detach if not already detached */
2549 dlm_mle_detach_hb_events(dlm, oldmle);
2550 dlm_put_mle(oldmle);
2551 }
2552
2553 if (ret < 0) {
2554 if (mle_added) {
2555 dlm_mle_detach_hb_events(dlm, mle);
2556 dlm_put_mle(mle);
2557 } else if (mle) {
2558 kmem_cache_free(dlm_mle_cache, mle);
66effd3c 2559 mle = NULL;
6714d8e8
KH		 2560 }
2561 goto leave;
2562 }
2563
2564 /*
2565 * at this point, we have a migration target, an mle
2566 * in the master list, and the MIGRATING flag set on
2567 * the lockres
2568 */
2569
1cd04dbe
KH		 2570 /* now that remote nodes are spinning on the MIGRATING flag,
2571 * ensure that all assert_master work is flushed. */
2572 flush_workqueue(dlm->dlm_worker);
6714d8e8
KH		 2573
2574 /* get an extra reference on the mle.
2575 * otherwise the assert_master from the new
2576 * master will destroy this.
2577 * also, make sure that all callers of dlm_get_mle
2578 * take both dlm->spinlock and dlm->master_lock */
2579 spin_lock(&dlm->spinlock);
2580 spin_lock(&dlm->master_lock);
a2bf0477 2581 dlm_get_mle_inuse(mle);
6714d8e8
KH		 2582 spin_unlock(&dlm->master_lock);
2583 spin_unlock(&dlm->spinlock);
2584
2585 /* notify new node and send all lock state */
2586 /* call send_one_lockres with migration flag.
2587 * this serves as notice to the target node that a
2588 * migration is starting. */
2589 ret = dlm_send_one_lockres(dlm, res, mres, target,
2590 DLM_MRES_MIGRATION);
2591
2592 if (ret < 0) {
2593 mlog(0, "migration to node %u failed with %d\n",
2594 target, ret);
2595 /* migration failed, detach and clean up mle */
2596 dlm_mle_detach_hb_events(dlm, mle);
2597 dlm_put_mle(mle);
a2bf0477
KH		 2598 dlm_put_mle_inuse(mle);
2599 spin_lock(&res->spinlock);
2600 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 2601 wake = 1;
a2bf0477 2602 spin_unlock(&res->spinlock);
df016c66
SM		 2603 if (dlm_is_host_down(ret))
2604 dlm_wait_for_node_death(dlm, target,
2605 DLM_NODE_DEATH_WAIT_MAX);
6714d8e8
KH		 2606 goto leave;
2607 }
2608
2609 /* at this point, the target sends a message to all nodes,
2610 * (using dlm_do_migrate_request). this node is skipped since
2611 * we had to put an mle in the list to begin the process. this
2612 * node now waits for target to do an assert master. this node
2613 * will be the last one notified, ensuring that the migration
2614 * is complete everywhere. if the target dies while this is
2615 * going on, some nodes could potentially see the target as the
2616 * master, so it is important that my recovery finds the migration
af901ca1 2617 * mle and sets the master to UNKNOWN. */
6714d8e8
KH		 2618
2619
2620 /* wait for new node to assert master */
2621 while (1) {
2622 ret = wait_event_interruptible_timeout(mle->wq,
2623 (atomic_read(&mle->woken) == 1),
2624 msecs_to_jiffies(5000));
2625
2626 if (ret >= 0) {
2627 if (atomic_read(&mle->woken) == 1 ||
2628 res->owner == target)
2629 break;
2630
1cd04dbe
KH		 2631 mlog(0, "%s:%.*s: timed out during migration\n",
2632 dlm->name, res->lockname.len, res->lockname.name);
2bd63216 2633 /* avoid hang during shutdown when migrating lockres
e2faea4c
KH		 2634 * to a node which also goes down */
2635 if (dlm_is_node_dead(dlm, target)) {
aa852354
KH		 2636 mlog(0, "%s:%.*s: expected migration "
2637 "target %u is no longer up, restarting\n",
e2faea4c
KH		 2638 dlm->name, res->lockname.len,
2639 res->lockname.name, target);
1cd04dbe
KH		 2640 ret = -EINVAL;
2641 /* migration failed, detach and clean up mle */
2642 dlm_mle_detach_hb_events(dlm, mle);
2643 dlm_put_mle(mle);
2644 dlm_put_mle_inuse(mle);
2645 spin_lock(&res->spinlock);
2646 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 2647 wake = 1;
1cd04dbe
KH		 2648 spin_unlock(&res->spinlock);
2649 goto leave;
e2faea4c 2650 }
1cd04dbe
KH		 2651 } else
2652 mlog(0, "%s:%.*s: caught signal during migration\n",
2653 dlm->name, res->lockname.len, res->lockname.name);
6714d8e8
KH		 2654 }
2655
2656 /* all done, set the owner, clear the flag */
2657 spin_lock(&res->spinlock);
2658 dlm_set_lockres_owner(dlm, res, target);
2659 res->state &= ~DLM_LOCK_RES_MIGRATING;
2660 dlm_remove_nonlocal_locks(dlm, res);
2661 spin_unlock(&res->spinlock);
2662 wake_up(&res->wq);
2663
2664 /* master is known, detach if not already detached */
2665 dlm_mle_detach_hb_events(dlm, mle);
a2bf0477 2666 dlm_put_mle_inuse(mle);
6714d8e8
KH		 2667 ret = 0;
2668
2669 dlm_lockres_calc_usage(dlm, res);
2670
2671leave:
2672 /* re-dirty the lockres if we failed */
2673 if (ret < 0)
2674 dlm_kick_thread(dlm, res);
2675
a6fa3640
KH		 2676 /* wake up waiters if the MIGRATING flag got set
2677 * but migration failed */
2678 if (wake)
2679 wake_up(&res->wq);
2680
6714d8e8
KH		 2681 if (mres)
2682 free_page((unsigned long)mres);
2683
2684 dlm_put(dlm);
2685
9f62e960
SM		 2686 mlog(0, "%s: Migrating %.*s to %u, returns %d\n", dlm->name, namelen,
2687 name, target, ret);
6714d8e8
KH		 2688 return ret;
2689}
6714d8e8 2690
ba2bf218
KH		 2691#define DLM_MIGRATION_RETRY_MS 100
2692
9f62e960
SM		 2693/*
2694 * Should be called only after beginning the domain leave process.
ba2bf218
KH		 2695 * There should not be any remaining locks on nonlocal lock resources,
2696 * and there should be no local locks left on locally mastered resources.
2697 *
2698 * Called with the dlm spinlock held, may drop it to do migration, but
2699 * will re-acquire before exit.
2700 *
9f62e960
SM		 2701 * Returns: 1 if dlm->spinlock was dropped/retaken, 0 if never dropped
2702 */
ba2bf218
KH		 2703int dlm_empty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
2704{
66effd3c 2705 int ret;
ba2bf218 2706 int lock_dropped = 0;
66effd3c 2707 u8 target = O2NM_MAX_NODES;
ba2bf218 2708
9f62e960 2709 assert_spin_locked(&dlm->spinlock);
2f5bf1f2 2710
9f62e960 2711 spin_lock(&res->spinlock);
66effd3c
SM		 2712 if (dlm_is_lockres_migrateable(dlm, res))
2713 target = dlm_pick_migration_target(dlm, res);
b36c3f84 2714 spin_unlock(&res->spinlock);
66effd3c
SM		 2715
2716 if (target == O2NM_MAX_NODES)
9f62e960 2717 goto leave;
ba2bf218
KH		 2718
2719 /* Wheee! Migrate lockres here! Will sleep so drop spinlock. */
2720 spin_unlock(&dlm->spinlock);
2721 lock_dropped = 1;
66effd3c
SM		 2722 ret = dlm_migrate_lockres(dlm, res, target);
2723 if (ret)
2724 mlog(0, "%s: res %.*s, Migrate to node %u failed with %d\n",
2725 dlm->name, res->lockname.len, res->lockname.name,
2726 target, ret);
ba2bf218
KH		 2727 spin_lock(&dlm->spinlock);
2728leave:
2729 return lock_dropped;
2730}
2731
6714d8e8
KH		 2732int dlm_lock_basts_flushed(struct dlm_ctxt *dlm, struct dlm_lock *lock)
2733{
2734 int ret;
2735 spin_lock(&dlm->ast_lock);
2736 spin_lock(&lock->spinlock);
2737 ret = (list_empty(&lock->bast_list) && !lock->bast_pending);
2738 spin_unlock(&lock->spinlock);
2739 spin_unlock(&dlm->ast_lock);
2740 return ret;
2741}
2742
2743static int dlm_migration_can_proceed(struct dlm_ctxt *dlm,
2744 struct dlm_lock_resource *res,
2745 u8 mig_target)
2746{
2747 int can_proceed;
2748 spin_lock(&res->spinlock);
2749 can_proceed = !!(res->state & DLM_LOCK_RES_MIGRATING);
2750 spin_unlock(&res->spinlock);
2751
2bd63216 2752 /* target has died, so make the caller break out of the
6714d8e8
KH		 2753 * wait_event, but caller must recheck the domain_map */
2754 spin_lock(&dlm->spinlock);
2755 if (!test_bit(mig_target, dlm->domain_map))
2756 can_proceed = 1;
2757 spin_unlock(&dlm->spinlock);
2758 return can_proceed;
2759}
2760
faf0ec9f
AB		 2761static int dlm_lockres_is_dirty(struct dlm_ctxt *dlm,
2762 struct dlm_lock_resource *res)
6714d8e8
KH		 2763{
2764 int ret;
2765 spin_lock(&res->spinlock);
2766 ret = !!(res->state & DLM_LOCK_RES_DIRTY);
2767 spin_unlock(&res->spinlock);
2768 return ret;
2769}
2770
2771
2772static int dlm_mark_lockres_migrating(struct dlm_ctxt *dlm,
2773 struct dlm_lock_resource *res,
2774 u8 target)
2775{
2776 int ret = 0;
2777
2778 mlog(0, "dlm_mark_lockres_migrating: %.*s, from %u to %u\n",
2779 res->lockname.len, res->lockname.name, dlm->node_num,
2780 target);
2781 /* need to set MIGRATING flag on lockres. this is done by
2782 * ensuring that all asts have been flushed for this lockres. */
2783 spin_lock(&res->spinlock);
2784 BUG_ON(res->migration_pending);
2785 res->migration_pending = 1;
2786 /* strategy is to reserve an extra ast then release
2787 * it below, letting the release do all of the work */
2788 __dlm_lockres_reserve_ast(res);
2789 spin_unlock(&res->spinlock);
2790
ddc09c8d 2791 /* now flush all the pending asts */
6714d8e8 2792 dlm_kick_thread(dlm, res);
ddc09c8d
KH		 2793 /* before waiting on DIRTY, block processes which may
2794 * try to dirty the lockres before MIGRATING is set */
2795 spin_lock(&res->spinlock);
2796 BUG_ON(res->state & DLM_LOCK_RES_BLOCK_DIRTY);
2797 res->state |= DLM_LOCK_RES_BLOCK_DIRTY;
2798 spin_unlock(&res->spinlock);
2799 /* now wait on any pending asts and the DIRTY state */
6714d8e8
KH		 2800 wait_event(dlm->ast_wq, !dlm_lockres_is_dirty(dlm, res));
2801 dlm_lockres_release_ast(dlm, res);
2802
2803 mlog(0, "about to wait on migration_wq, dirty=%s\n",
2804 res->state & DLM_LOCK_RES_DIRTY ? "yes" : "no");
2805 /* if the extra ref we just put was the final one, this
2806 * will pass thru immediately. otherwise, we need to wait
2807 * for the last ast to finish. */
2808again:
2809 ret = wait_event_interruptible_timeout(dlm->migration_wq,
2810 dlm_migration_can_proceed(dlm, res, target),
2811 msecs_to_jiffies(1000));
2812 if (ret < 0) {
2813 mlog(0, "woken again: migrating? %s, dead? %s\n",
2814 res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no",
2815 test_bit(target, dlm->domain_map) ? "no":"yes");
2816 } else {
2817 mlog(0, "all is well: migrating? %s, dead? %s\n",
2818 res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no",
2819 test_bit(target, dlm->domain_map) ? "no":"yes");
2820 }
2821 if (!dlm_migration_can_proceed(dlm, res, target)) {
2822 mlog(0, "trying again...\n");
2823 goto again;
2824 }
2825
a39953dd 2826 ret = 0;
6714d8e8
KH		 2827 /* did the target go down or die? */
2828 spin_lock(&dlm->spinlock);
2829 if (!test_bit(target, dlm->domain_map)) {
2830 mlog(ML_ERROR, "aha. migration target %u just went down\n",
2831 target);
2832 ret = -EHOSTDOWN;
2833 }
2834 spin_unlock(&dlm->spinlock);
2835
a39953dd
WW		 2836 /*
2837 * if target is down, we need to clear DLM_LOCK_RES_BLOCK_DIRTY for
2838 * another try; otherwise, we are sure the MIGRATING state is there,
2839 * drop the unneded state which blocked threads trying to DIRTY
2840 */
2841 spin_lock(&res->spinlock);
2842 BUG_ON(!(res->state & DLM_LOCK_RES_BLOCK_DIRTY));
2843 res->state &= ~DLM_LOCK_RES_BLOCK_DIRTY;
2844 if (!ret)
2845 BUG_ON(!(res->state & DLM_LOCK_RES_MIGRATING));
cc28d6d8 2846 else
2847 res->migration_pending = 0;
a39953dd
WW		 2848 spin_unlock(&res->spinlock);
2849
6714d8e8
KH		 2850 /*
2851 * at this point:
2852 *
a39953dd 2853 * o the DLM_LOCK_RES_MIGRATING flag is set if target not down
6714d8e8
KH		 2854 * o there are no pending asts on this lockres
2855 * o all processes trying to reserve an ast on this
2856 * lockres must wait for the MIGRATING flag to clear
2857 */
2858 return ret;
2859}
2860
2861/* last step in the migration process.
2862 * original master calls this to free all of the dlm_lock
2863 * structures that used to be for other nodes. */
2864static void dlm_remove_nonlocal_locks(struct dlm_ctxt *dlm,
2865 struct dlm_lock_resource *res)
2866{
6714d8e8 2867 struct list_head *queue = &res->granted;
ba2bf218 2868 int i, bit;
800deef3 2869 struct dlm_lock *lock, *next;
6714d8e8
KH		 2870
2871 assert_spin_locked(&res->spinlock);
2872
2873 BUG_ON(res->owner == dlm->node_num);
2874
2875 for (i=0; i<3; i++) {
800deef3 2876 list_for_each_entry_safe(lock, next, queue, list) {
6714d8e8
KH		 2877 if (lock->ml.node != dlm->node_num) {
2878 mlog(0, "putting lock for node %u\n",
2879 lock->ml.node);
2880 /* be extra careful */
2881 BUG_ON(!list_empty(&lock->ast_list));
2882 BUG_ON(!list_empty(&lock->bast_list));
2883 BUG_ON(lock->ast_pending);
2884 BUG_ON(lock->bast_pending);
8d400b81
SM		 2885 dlm_lockres_clear_refmap_bit(dlm, res,
2886 lock->ml.node);
6714d8e8
KH		 2887 list_del_init(&lock->list);
2888 dlm_lock_put(lock);
2c5c54ac
SM		 2889 /* In a normal unlock, we would have added a
2890 * DLM_UNLOCK_FREE_LOCK action. Force it. */
2891 dlm_lock_put(lock);
6714d8e8
KH		 2892 }
2893 }
2894 queue++;
2895 }
ba2bf218
KH		 2896 bit = 0;
2897 while (1) {
2898 bit = find_next_bit(res->refmap, O2NM_MAX_NODES, bit);
2899 if (bit >= O2NM_MAX_NODES)
2900 break;
2901 /* do not clear the local node reference, if there is a
2902 * process holding this, let it drop the ref itself */
2903 if (bit != dlm->node_num) {
2904 mlog(0, "%s:%.*s: node %u had a ref to this "
2905 "migrating lockres, clearing\n", dlm->name,
2906 res->lockname.len, res->lockname.name, bit);
8d400b81 2907 dlm_lockres_clear_refmap_bit(dlm, res, bit);
ba2bf218
KH		 2908 }
2909 bit++;
2910 }
6714d8e8
KH		 2911}
2912
66effd3c
SM		 2913/*
2914 * Pick a node to migrate the lock resource to. This function selects a
2915 * potential target based first on the locks and then on refmap. It skips
2916 * nodes that are in the process of exiting the domain.
2917 */
6714d8e8
KH		 2918static u8 dlm_pick_migration_target(struct dlm_ctxt *dlm,
2919 struct dlm_lock_resource *res)
2920{
66effd3c 2921 enum dlm_lockres_list idx;
6714d8e8 2922 struct list_head *queue = &res->granted;
6714d8e8 2923 struct dlm_lock *lock;
66effd3c
SM		 2924 int noderef;
2925 u8 nodenum = O2NM_MAX_NODES;
6714d8e8
KH		 2926
2927 assert_spin_locked(&dlm->spinlock);
66effd3c 2928 assert_spin_locked(&res->spinlock);
6714d8e8 2929
66effd3c
SM		 2930 /* Go through all the locks */
2931 for (idx = DLM_GRANTED_LIST; idx <= DLM_BLOCKED_LIST; idx++) {
2932 queue = dlm_list_idx_to_ptr(res, idx);
800deef3 2933 list_for_each_entry(lock, queue, list) {
66effd3c
SM		 2934 if (lock->ml.node == dlm->node_num)
2935 continue;
2936 if (test_bit(lock->ml.node, dlm->exit_domain_map))
2937 continue;
2938 nodenum = lock->ml.node;
2939 goto bail;
6714d8e8 2940 }
6714d8e8 2941 }
388c4bcb 2942
66effd3c
SM		 2943 /* Go thru the refmap */
2944 noderef = -1;
6714d8e8 2945 while (1) {
66effd3c
SM		 2946 noderef = find_next_bit(res->refmap, O2NM_MAX_NODES,
2947 noderef + 1);
2948 if (noderef >= O2NM_MAX_NODES)
6714d8e8 2949 break;
66effd3c
SM		 2950 if (noderef == dlm->node_num)
2951 continue;
2952 if (test_bit(noderef, dlm->exit_domain_map))
2953 continue;
2954 nodenum = noderef;
2955 goto bail;
6714d8e8
KH		 2956 }
2957
66effd3c
SM		 2958bail:
2959 return nodenum;
6714d8e8
KH		 2960}
2961
6714d8e8
KH		 2962/* this is called by the new master once all lockres
2963 * data has been received */
2964static int dlm_do_migrate_request(struct dlm_ctxt *dlm,
2965 struct dlm_lock_resource *res,
2966 u8 master, u8 new_master,
2967 struct dlm_node_iter *iter)
2968{
2969 struct dlm_migrate_request migrate;
2b832564 2970 int ret, skip, status = 0;
6714d8e8
KH		 2971 int nodenum;
2972
2973 memset(&migrate, 0, sizeof(migrate));
2974 migrate.namelen = res->lockname.len;
2975 memcpy(migrate.name, res->lockname.name, migrate.namelen);
2976 migrate.new_master = new_master;
2977 migrate.master = master;
2978
2979 ret = 0;
2980
2981 /* send message to all nodes, except the master and myself */
2982 while ((nodenum = dlm_node_iter_next(iter)) >= 0) {
2983 if (nodenum == master ||
2984 nodenum == new_master)
2985 continue;
2986
2b832564
SM		 2987 /* We could race exit domain. If exited, skip. */
2988 spin_lock(&dlm->spinlock);
2989 skip = (!test_bit(nodenum, dlm->domain_map));
2990 spin_unlock(&dlm->spinlock);
2991 if (skip) {
2992 clear_bit(nodenum, iter->node_map);
2993 continue;
2994 }
2995
6714d8e8
KH		 2996 ret = o2net_send_message(DLM_MIGRATE_REQUEST_MSG, dlm->key,
2997 &migrate, sizeof(migrate), nodenum,
2998 &status);
2b832564 2999 if (ret < 0) {
8decab3c
SM		 3000 mlog(ML_ERROR, "%s: res %.*s, Error %d send "
3001 "MIGRATE_REQUEST to node %u\n", dlm->name,
3002 migrate.namelen, migrate.name, ret, nodenum);
2b832564
SM		 3003 if (!dlm_is_host_down(ret)) {
3004 mlog(ML_ERROR, "unhandled error=%d!\n", ret);
3005 BUG();
3006 }
3007 clear_bit(nodenum, iter->node_map);
3008 ret = 0;
3009 } else if (status < 0) {
6714d8e8
KH		 3010 mlog(0, "migrate request (node %u) returned %d!\n",
3011 nodenum, status);
3012 ret = status;
ba2bf218
KH		 3013 } else if (status == DLM_MIGRATE_RESPONSE_MASTERY_REF) {
3014 /* during the migration request we short-circuited
3015 * the mastery of the lockres. make sure we have
3016 * a mastery ref for nodenum */
3017 mlog(0, "%s:%.*s: need ref for node %u\n",
3018 dlm->name, res->lockname.len, res->lockname.name,
3019 nodenum);
3020 spin_lock(&res->spinlock);
8d400b81 3021 dlm_lockres_set_refmap_bit(dlm, res, nodenum);
ba2bf218 3022 spin_unlock(&res->spinlock);
6714d8e8
KH		 3023 }
3024 }
3025
3026 if (ret < 0)
3027 mlog_errno(ret);
3028
3029 mlog(0, "returning ret=%d\n", ret);
3030 return ret;
3031}
3032
3033
3034/* if there is an existing mle for this lockres, we now know who the master is.
3035 * (the one who sent us *this* message) we can clear it up right away.
3036 * since the process that put the mle on the list still has a reference to it,
3037 * we can unhash it now, set the master and wake the process. as a result,
3038 * we will have no mle in the list to start with. now we can add an mle for
3039 * the migration and this should be the only one found for those scanning the
3040 * list. */
d74c9803
KH		 3041int dlm_migrate_request_handler(struct o2net_msg *msg, u32 len, void *data,
3042 void **ret_data)
6714d8e8
KH		 3043{
3044 struct dlm_ctxt *dlm = data;
3045 struct dlm_lock_resource *res = NULL;
3046 struct dlm_migrate_request *migrate = (struct dlm_migrate_request *) msg->buf;
3047 struct dlm_master_list_entry *mle = NULL, *oldmle = NULL;
3048 const char *name;
a3d33291 3049 unsigned int namelen, hash;
6714d8e8
KH		 3050 int ret = 0;
3051
3052 if (!dlm_grab(dlm))
3053 return -EINVAL;
3054
3055 name = migrate->name;
3056 namelen = migrate->namelen;
a3d33291 3057 hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 3058
3059 /* preallocate.. if this fails, abort */
3914ed0c 3060 mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
6714d8e8
KH		 3061
3062 if (!mle) {
3063 ret = -ENOMEM;
3064 goto leave;
3065 }
3066
3067 /* check for pre-existing lock */
3068 spin_lock(&dlm->spinlock);
a3d33291 3069 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
6714d8e8
KH		 3070 if (res) {
3071 spin_lock(&res->spinlock);
3072 if (res->state & DLM_LOCK_RES_RECOVERING) {
3073 /* if all is working ok, this can only mean that we got
3074 * a migrate request from a node that we now see as
3075 * dead. what can we do here? drop it to the floor? */
3076 spin_unlock(&res->spinlock);
3077 mlog(ML_ERROR, "Got a migrate request, but the "
3078 "lockres is marked as recovering!");
3079 kmem_cache_free(dlm_mle_cache, mle);
3080 ret = -EINVAL; /* need a better solution */
3081 goto unlock;
3082 }
3083 res->state |= DLM_LOCK_RES_MIGRATING;
3084 spin_unlock(&res->spinlock);
3085 }
3086
6d98c3cc 3087 spin_lock(&dlm->master_lock);
6714d8e8
KH		 3088 /* ignore status. only nonzero status would BUG. */
3089 ret = dlm_add_migration_mle(dlm, res, mle, &oldmle,
3090 name, namelen,
3091 migrate->new_master,
3092 migrate->master);
3093
6714d8e8 3094 spin_unlock(&dlm->master_lock);
6d98c3cc 3095unlock:
6714d8e8
KH		 3096 spin_unlock(&dlm->spinlock);
3097
3098 if (oldmle) {
3099 /* master is known, detach if not already detached */
3100 dlm_mle_detach_hb_events(dlm, oldmle);
3101 dlm_put_mle(oldmle);
3102 }
3103
3104 if (res)
3105 dlm_lockres_put(res);
3106leave:
3107 dlm_put(dlm);
3108 return ret;
3109}
3110
3111/* must be holding dlm->spinlock and dlm->master_lock
3112 * when adding a migration mle, we can clear any other mles
3113 * in the master list because we know with certainty that
3114 * the master is "master". so we remove any old mle from
3115 * the list after setting it's master field, and then add
3116 * the new migration mle. this way we can hold with the rule
3117 * of having only one mle for a given lock name at all times. */
3118static int dlm_add_migration_mle(struct dlm_ctxt *dlm,
3119 struct dlm_lock_resource *res,
3120 struct dlm_master_list_entry *mle,
3121 struct dlm_master_list_entry **oldmle,
3122 const char *name, unsigned int namelen,
3123 u8 new_master, u8 master)
3124{
3125 int found;
3126 int ret = 0;
3127
3128 *oldmle = NULL;
3129
6714d8e8
KH		 3130 assert_spin_locked(&dlm->spinlock);
3131 assert_spin_locked(&dlm->master_lock);
3132
3133 /* caller is responsible for any ref taken here on oldmle */
3134 found = dlm_find_mle(dlm, oldmle, (char *)name, namelen);
3135 if (found) {
3136 struct dlm_master_list_entry *tmp = *oldmle;
3137 spin_lock(&tmp->spinlock);
3138 if (tmp->type == DLM_MLE_MIGRATION) {
3139 if (master == dlm->node_num) {
3140 /* ah another process raced me to it */
3141 mlog(0, "tried to migrate %.*s, but some "
3142 "process beat me to it\n",
3143 namelen, name);
3144 ret = -EEXIST;
3145 } else {
3146 /* bad. 2 NODES are trying to migrate! */
3147 mlog(ML_ERROR, "migration error mle: "
3148 "master=%u new_master=%u // request: "
3149 "master=%u new_master=%u // "
3150 "lockres=%.*s\n",
3151 tmp->master, tmp->new_master,
3152 master, new_master,
3153 namelen, name);
3154 BUG();
3155 }
3156 } else {
3157 /* this is essentially what assert_master does */
3158 tmp->master = master;
3159 atomic_set(&tmp->woken, 1);
3160 wake_up(&tmp->wq);
1c084577
SM		 3161 /* remove it so that only one mle will be found */
3162 __dlm_unlink_mle(dlm, tmp);
ba2bf218 3163 __dlm_mle_detach_hb_events(dlm, tmp);
b9aaac5a 3164 if (tmp->type == DLM_MLE_MASTER) {
3165 ret = DLM_MIGRATE_RESPONSE_MASTERY_REF;
3166 mlog(0, "%s:%.*s: master=%u, newmaster=%u, "
3167 "telling master to get ref "
3168 "for cleared out mle during "
3169 "migration\n", dlm->name,
3170 namelen, name, master,
3171 new_master);
3172 }
6714d8e8
KH		 3173 }
3174 spin_unlock(&tmp->spinlock);
3175 }
3176
3177 /* now add a migration mle to the tail of the list */
3178 dlm_init_mle(mle, DLM_MLE_MIGRATION, dlm, res, name, namelen);
3179 mle->new_master = new_master;
ba2bf218
KH		 3180 /* the new master will be sending an assert master for this.
3181 * at that point we will get the refmap reference */
6714d8e8
KH		 3182 mle->master = master;
3183 /* do this for consistency with other mle types */
3184 set_bit(new_master, mle->maybe_map);
1c084577 3185 __dlm_insert_mle(dlm, mle);
6714d8e8
KH		 3186
3187 return ret;
3188}
3189
c2cd4a44
SM		 3190/*
3191 * Sets the owner of the lockres, associated to the mle, to UNKNOWN
3192 */
3193static struct dlm_lock_resource *dlm_reset_mleres_owner(struct dlm_ctxt *dlm,
3194 struct dlm_master_list_entry *mle)
3195{
3196 struct dlm_lock_resource *res;
c2cd4a44
SM		 3197
3198 /* Find the lockres associated to the mle and set its owner to UNK */
7141514b
SM		 3199 res = __dlm_lookup_lockres(dlm, mle->mname, mle->mnamelen,
3200 mle->mnamehash);
c2cd4a44
SM		 3201 if (res) {
3202 spin_unlock(&dlm->master_lock);
3203
3204 /* move lockres onto recovery list */
3205 spin_lock(&res->spinlock);
3206 dlm_set_lockres_owner(dlm, res, DLM_LOCK_RES_OWNER_UNKNOWN);
3207 dlm_move_lockres_to_recovery_list(dlm, res);
3208 spin_unlock(&res->spinlock);
3209 dlm_lockres_put(res);
3210
3211 /* about to get rid of mle, detach from heartbeat */
3212 __dlm_mle_detach_hb_events(dlm, mle);
3213
3214 /* dump the mle */
3215 spin_lock(&dlm->master_lock);
3216 __dlm_put_mle(mle);
3217 spin_unlock(&dlm->master_lock);
3218 }
3219
3220 return res;
3221}
3222
3223static void dlm_clean_migration_mle(struct dlm_ctxt *dlm,
3224 struct dlm_master_list_entry *mle)
3225{
3226 __dlm_mle_detach_hb_events(dlm, mle);
3227
3228 spin_lock(&mle->spinlock);
3229 __dlm_unlink_mle(dlm, mle);
3230 atomic_set(&mle->woken, 1);
3231 spin_unlock(&mle->spinlock);
3232
3233 wake_up(&mle->wq);
3234}
3235
3236static void dlm_clean_block_mle(struct dlm_ctxt *dlm,
3237 struct dlm_master_list_entry *mle, u8 dead_node)
3238{
3239 int bit;
3240
3241 BUG_ON(mle->type != DLM_MLE_BLOCK);
3242
3243 spin_lock(&mle->spinlock);
3244 bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0);
3245 if (bit != dead_node) {
3246 mlog(0, "mle found, but dead node %u would not have been "
3247 "master\n", dead_node);
3248 spin_unlock(&mle->spinlock);
3249 } else {
3250 /* Must drop the refcount by one since the assert_master will
3251 * never arrive. This may result in the mle being unlinked and
3252 * freed, but there may still be a process waiting in the
3253 * dlmlock path which is fine. */
3254 mlog(0, "node %u was expected master\n", dead_node);
3255 atomic_set(&mle->woken, 1);
3256 spin_unlock(&mle->spinlock);
3257 wake_up(&mle->wq);
3258
3259 /* Do not need events any longer, so detach from heartbeat */
3260 __dlm_mle_detach_hb_events(dlm, mle);
3261 __dlm_put_mle(mle);
3262 }
3263}
6714d8e8
KH		 3264
3265void dlm_clean_master_list(struct dlm_ctxt *dlm, u8 dead_node)
3266{
2ed6c750 3267 struct dlm_master_list_entry *mle;
6714d8e8 3268 struct dlm_lock_resource *res;
2ed6c750 3269 struct hlist_head *bucket;
df53cd3b 3270 struct hlist_node *tmp;
2ed6c750 3271 unsigned int i;
6714d8e8 3272
ef6b689b 3273 mlog(0, "dlm=%s, dead node=%u\n", dlm->name, dead_node);
6714d8e8
KH		 3274top:
3275 assert_spin_locked(&dlm->spinlock);
3276
3277 /* clean the master list */
3278 spin_lock(&dlm->master_lock);
2ed6c750
SM		 3279 for (i = 0; i < DLM_HASH_BUCKETS; i++) {
3280 bucket = dlm_master_hash(dlm, i);
df53cd3b 3281 hlist_for_each_entry_safe(mle, tmp, bucket, master_hash_node) {
67ae1f06
SM		 3282 BUG_ON(mle->type != DLM_MLE_BLOCK &&
3283 mle->type != DLM_MLE_MASTER &&
3284 mle->type != DLM_MLE_MIGRATION);
3285
3286 /* MASTER mles are initiated locally. The waiting
3287 * process will notice the node map change shortly.
3288 * Let that happen as normal. */
3289 if (mle->type == DLM_MLE_MASTER)
3290 continue;
3291
3292 /* BLOCK mles are initiated by other nodes. Need to
3293 * clean up if the dead node would have been the
3294 * master. */
3295 if (mle->type == DLM_MLE_BLOCK) {
3296 dlm_clean_block_mle(dlm, mle, dead_node);
3297 continue;
3298 }
6714d8e8 3299
67ae1f06
SM		 3300 /* Everything else is a MIGRATION mle */
3301
3302 /* The rule for MIGRATION mles is that the master
3303 * becomes UNKNOWN if *either* the original or the new
3304 * master dies. All UNKNOWN lockres' are sent to
3305 * whichever node becomes the recovery master. The new
3306 * master is responsible for determining if there is
3307 * still a master for this lockres, or if he needs to
3308 * take over mastery. Either way, this node should
3309 * expect another message to resolve this. */
3310
3311 if (mle->master != dead_node &&
3312 mle->new_master != dead_node)
3313 continue;
3314
3315 /* If we have reached this point, this mle needs to be
3316 * removed from the list and freed. */
3317 dlm_clean_migration_mle(dlm, mle);
3318
3319 mlog(0, "%s: node %u died during migration from "
3320 "%u to %u!\n", dlm->name, dead_node, mle->master,
3321 mle->new_master);
3322
3323 /* If we find a lockres associated with the mle, we've
3324 * hit this rare case that messes up our lock ordering.
3325 * If so, we need to drop the master lock so that we can
3326 * take the lockres lock, meaning that we will have to
3327 * restart from the head of list. */
3328 res = dlm_reset_mleres_owner(dlm, mle);
3329 if (res)
3330 /* restart */
3331 goto top;
3332
3333 /* This may be the last reference */
3334 __dlm_put_mle(mle);
6714d8e8 3335 }
2ed6c750 3336 }
6714d8e8
KH		 3337 spin_unlock(&dlm->master_lock);
3338}
3339
6714d8e8
KH		 3340int dlm_finish_migration(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
3341 u8 old_master)
3342{
3343 struct dlm_node_iter iter;
3344 int ret = 0;
3345
3346 spin_lock(&dlm->spinlock);
3347 dlm_node_iter_init(dlm->domain_map, &iter);
3348 clear_bit(old_master, iter.node_map);
3349 clear_bit(dlm->node_num, iter.node_map);
3350 spin_unlock(&dlm->spinlock);
3351
ba2bf218
KH		 3352 /* ownership of the lockres is changing. account for the
3353 * mastery reference here since old_master will briefly have
3354 * a reference after the migration completes */
3355 spin_lock(&res->spinlock);
8d400b81 3356 dlm_lockres_set_refmap_bit(dlm, res, old_master);
ba2bf218
KH		 3357 spin_unlock(&res->spinlock);
3358
6714d8e8
KH		 3359 mlog(0, "now time to do a migrate request to other nodes\n");
3360 ret = dlm_do_migrate_request(dlm, res, old_master,
3361 dlm->node_num, &iter);
3362 if (ret < 0) {
3363 mlog_errno(ret);
3364 goto leave;
3365 }
3366
3367 mlog(0, "doing assert master of %.*s to all except the original node\n",
3368 res->lockname.len, res->lockname.name);
3369 /* this call now finishes out the nodemap
3370 * even if one or more nodes die */
ba2bf218 3371 ret = dlm_do_assert_master(dlm, res, iter.node_map,
6714d8e8
KH		 3372 DLM_ASSERT_MASTER_FINISH_MIGRATION);
3373 if (ret < 0) {
3374 /* no longer need to retry. all living nodes contacted. */
3375 mlog_errno(ret);
3376 ret = 0;
3377 }
3378
3379 memset(iter.node_map, 0, sizeof(iter.node_map));
3380 set_bit(old_master, iter.node_map);
3381 mlog(0, "doing assert master of %.*s back to %u\n",
3382 res->lockname.len, res->lockname.name, old_master);
ba2bf218 3383 ret = dlm_do_assert_master(dlm, res, iter.node_map,
6714d8e8
KH		 3384 DLM_ASSERT_MASTER_FINISH_MIGRATION);
3385 if (ret < 0) {
3386 mlog(0, "assert master to original master failed "
3387 "with %d.\n", ret);
3388 /* the only nonzero status here would be because of
3389 * a dead original node. we're done. */
3390 ret = 0;
3391 }
3392
3393 /* all done, set the owner, clear the flag */
3394 spin_lock(&res->spinlock);
3395 dlm_set_lockres_owner(dlm, res, dlm->node_num);
3396 res->state &= ~DLM_LOCK_RES_MIGRATING;
3397 spin_unlock(&res->spinlock);
3398 /* re-dirty it on the new master */
3399 dlm_kick_thread(dlm, res);
3400 wake_up(&res->wq);
3401leave:
3402 return ret;
3403}
3404
3405/*
3406 * LOCKRES AST REFCOUNT
3407 * this is integral to migration
3408 */
3409
3410/* for future intent to call an ast, reserve one ahead of time.
3411 * this should be called only after waiting on the lockres
3412 * with dlm_wait_on_lockres, and while still holding the
3413 * spinlock after the call. */
3414void __dlm_lockres_reserve_ast(struct dlm_lock_resource *res)
3415{
3416 assert_spin_locked(&res->spinlock);
3417 if (res->state & DLM_LOCK_RES_MIGRATING) {
3418 __dlm_print_one_lock_resource(res);
3419 }
3420 BUG_ON(res->state & DLM_LOCK_RES_MIGRATING);
3421
3422 atomic_inc(&res->asts_reserved);
3423}
3424
3425/*
3426 * used to drop the reserved ast, either because it went unused,
3427 * or because the ast/bast was actually called.
3428 *
3429 * also, if there is a pending migration on this lockres,
3430 * and this was the last pending ast on the lockres,
3431 * atomically set the MIGRATING flag before we drop the lock.
3432 * this is how we ensure that migration can proceed with no
3433 * asts in progress. note that it is ok if the state of the
3434 * queues is such that a lock should be granted in the future
3435 * or that a bast should be fired, because the new master will
3436 * shuffle the lists on this lockres as soon as it is migrated.
3437 */
3438void dlm_lockres_release_ast(struct dlm_ctxt *dlm,
3439 struct dlm_lock_resource *res)
3440{
3441 if (!atomic_dec_and_lock(&res->asts_reserved, &res->spinlock))
3442 return;
3443
3444 if (!res->migration_pending) {
3445 spin_unlock(&res->spinlock);
3446 return;
3447 }
3448
3449 BUG_ON(res->state & DLM_LOCK_RES_MIGRATING);
3450 res->migration_pending = 0;
3451 res->state |= DLM_LOCK_RES_MIGRATING;
3452 spin_unlock(&res->spinlock);
3453 wake_up(&res->wq);
3454 wake_up(&dlm->migration_wq);
3455}
5dad6c39
SE		 3456
3457void dlm_force_free_mles(struct dlm_ctxt *dlm)
3458{
3459 int i;
3460 struct hlist_head *bucket;
3461 struct dlm_master_list_entry *mle;
df53cd3b 3462 struct hlist_node *tmp;
5dad6c39
SE		 3463
3464 /*
3465 * We notified all other nodes that we are exiting the domain and
3466 * marked the dlm state to DLM_CTXT_LEAVING. If any mles are still
3467 * around we force free them and wake any processes that are waiting
3468 * on the mles
3469 */
3470 spin_lock(&dlm->spinlock);
3471 spin_lock(&dlm->master_lock);
3472
3473 BUG_ON(dlm->dlm_state != DLM_CTXT_LEAVING);
3474 BUG_ON((find_next_bit(dlm->domain_map, O2NM_MAX_NODES, 0) < O2NM_MAX_NODES));
3475
3476 for (i = 0; i < DLM_HASH_BUCKETS; i++) {
3477 bucket = dlm_master_hash(dlm, i);
df53cd3b 3478 hlist_for_each_entry_safe(mle, tmp, bucket, master_hash_node) {
5dad6c39
SE		 3479 if (mle->type != DLM_MLE_BLOCK) {
3480 mlog(ML_ERROR, "bad mle: %p\n", mle);
3481 dlm_print_one_mle(mle);
3482 }
3483 atomic_set(&mle->woken, 1);
3484 wake_up(&mle->wq);
3485
3486 __dlm_unlink_mle(dlm, mle);
3487 __dlm_mle_detach_hb_events(dlm, mle);
3488 __dlm_put_mle(mle);
3489 }
3490 }
3491 spin_unlock(&dlm->master_lock);
3492 spin_unlock(&dlm->spinlock);
3493}
Linux 6.x block layer and io_uring tree(s)