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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 144
[linux-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);
2c935bc5 236 if (!kref_read(&mle->mle_refs)) {
aa852354
KH		 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{
a17b485a 417 kmem_cache_destroy(dlm_mle_cache);
6714d8e8
KH		 418}
419
420static void dlm_mle_release(struct kref *kref)
421{
422 struct dlm_master_list_entry *mle;
423 struct dlm_ctxt *dlm;
424
6714d8e8
KH		 425 mle = container_of(kref, struct dlm_master_list_entry, mle_refs);
426 dlm = mle->dlm;
427
6714d8e8
KH		 428 assert_spin_locked(&dlm->spinlock);
429 assert_spin_locked(&dlm->master_lock);
430
7141514b
SM		 431 mlog(0, "Releasing mle for %.*s, type %d\n", mle->mnamelen, mle->mname,
432 mle->type);
2ed6c750 433
6714d8e8 434 /* remove from list if not already */
1c084577 435 __dlm_unlink_mle(dlm, mle);
6714d8e8
KH		 436
437 /* detach the mle from the domain node up/down events */
438 __dlm_mle_detach_hb_events(dlm, mle);
439
2041d8fd
SM		 440 atomic_dec(&dlm->mle_cur_count[mle->type]);
441
6714d8e8
KH		 442 /* NOTE: kfree under spinlock here.
443 * if this is bad, we can move this to a freelist. */
444 kmem_cache_free(dlm_mle_cache, mle);
445}
446
447
448/*
449 * LOCK RESOURCE FUNCTIONS
450 */
451
724bdca9
SM		 452int dlm_init_master_caches(void)
453{
454 dlm_lockres_cache = kmem_cache_create("o2dlm_lockres",
455 sizeof(struct dlm_lock_resource),
456 0, SLAB_HWCACHE_ALIGN, NULL);
457 if (!dlm_lockres_cache)
458 goto bail;
459
460 dlm_lockname_cache = kmem_cache_create("o2dlm_lockname",
461 DLM_LOCKID_NAME_MAX, 0,
462 SLAB_HWCACHE_ALIGN, NULL);
463 if (!dlm_lockname_cache)
464 goto bail;
465
466 return 0;
467bail:
468 dlm_destroy_master_caches();
469 return -ENOMEM;
470}
471
472void dlm_destroy_master_caches(void)
473{
a17b485a 474 kmem_cache_destroy(dlm_lockname_cache);
475 dlm_lockname_cache = NULL;
724bdca9 476
a17b485a 477 kmem_cache_destroy(dlm_lockres_cache);
478 dlm_lockres_cache = NULL;
724bdca9
SM		 479}
480
6714d8e8
KH		 481static void dlm_lockres_release(struct kref *kref)
482{
483 struct dlm_lock_resource *res;
b0d4f817 484 struct dlm_ctxt *dlm;
6714d8e8
KH		 485
486 res = container_of(kref, struct dlm_lock_resource, refs);
b0d4f817 487 dlm = res->dlm;
6714d8e8
KH		 488
489 /* This should not happen -- all lockres' have a name
490 * associated with them at init time. */
491 BUG_ON(!res->lockname.name);
492
493 mlog(0, "destroying lockres %.*s\n", res->lockname.len,
494 res->lockname.name);
495
6800791a
SM		 496 atomic_dec(&dlm->res_cur_count);
497
a7f90d83
KH		 498 if (!hlist_unhashed(&res->hash_node) ||
499 !list_empty(&res->granted) ||
500 !list_empty(&res->converting) ||
501 !list_empty(&res->blocked) ||
502 !list_empty(&res->dirty) ||
503 !list_empty(&res->recovering) ||
504 !list_empty(&res->purge)) {
505 mlog(ML_ERROR,
506 "Going to BUG for resource %.*s."
507 " We're on a list! [%c%c%c%c%c%c%c]\n",
508 res->lockname.len, res->lockname.name,
509 !hlist_unhashed(&res->hash_node) ? 'H' : ' ',
510 !list_empty(&res->granted) ? 'G' : ' ',
511 !list_empty(&res->converting) ? 'C' : ' ',
512 !list_empty(&res->blocked) ? 'B' : ' ',
513 !list_empty(&res->dirty) ? 'D' : ' ',
514 !list_empty(&res->recovering) ? 'R' : ' ',
515 !list_empty(&res->purge) ? 'P' : ' ');
516
517 dlm_print_one_lock_resource(res);
518 }
519
6714d8e8
KH		 520 /* By the time we're ready to blow this guy away, we shouldn't
521 * be on any lists. */
81f2094a 522 BUG_ON(!hlist_unhashed(&res->hash_node));
6714d8e8
KH		 523 BUG_ON(!list_empty(&res->granted));
524 BUG_ON(!list_empty(&res->converting));
525 BUG_ON(!list_empty(&res->blocked));
526 BUG_ON(!list_empty(&res->dirty));
527 BUG_ON(!list_empty(&res->recovering));
528 BUG_ON(!list_empty(&res->purge));
529
724bdca9 530 kmem_cache_free(dlm_lockname_cache, (void *)res->lockname.name);
6714d8e8 531
724bdca9 532 kmem_cache_free(dlm_lockres_cache, res);
6714d8e8
KH		 533}
534
6714d8e8
KH		 535void dlm_lockres_put(struct dlm_lock_resource *res)
536{
537 kref_put(&res->refs, dlm_lockres_release);
538}
539
540static void dlm_init_lockres(struct dlm_ctxt *dlm,
541 struct dlm_lock_resource *res,
542 const char *name, unsigned int namelen)
543{
544 char *qname;
545
546 /* If we memset here, we lose our reference to the kmalloc'd
547 * res->lockname.name, so be sure to init every field
548 * correctly! */
549
550 qname = (char *) res->lockname.name;
551 memcpy(qname, name, namelen);
552
553 res->lockname.len = namelen;
a3d33291 554 res->lockname.hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 555
556 init_waitqueue_head(&res->wq);
557 spin_lock_init(&res->spinlock);
81f2094a 558 INIT_HLIST_NODE(&res->hash_node);
6714d8e8
KH		 559 INIT_LIST_HEAD(&res->granted);
560 INIT_LIST_HEAD(&res->converting);
561 INIT_LIST_HEAD(&res->blocked);
562 INIT_LIST_HEAD(&res->dirty);
563 INIT_LIST_HEAD(&res->recovering);
564 INIT_LIST_HEAD(&res->purge);
29576f8b 565 INIT_LIST_HEAD(&res->tracking);
6714d8e8
KH		 566 atomic_set(&res->asts_reserved, 0);
567 res->migration_pending = 0;
ba2bf218 568 res->inflight_locks = 0;
ac4fef4d 569 res->inflight_assert_workers = 0;
6714d8e8 570
b0d4f817
SM		 571 res->dlm = dlm;
572
6714d8e8
KH		 573 kref_init(&res->refs);
574
6800791a
SM		 575 atomic_inc(&dlm->res_tot_count);
576 atomic_inc(&dlm->res_cur_count);
577
6714d8e8
KH		 578 /* just for consistency */
579 spin_lock(&res->spinlock);
580 dlm_set_lockres_owner(dlm, res, DLM_LOCK_RES_OWNER_UNKNOWN);
581 spin_unlock(&res->spinlock);
582
583 res->state = DLM_LOCK_RES_IN_PROGRESS;
584
585 res->last_used = 0;
586
cbe355f5 587 spin_lock(&dlm->track_lock);
29576f8b 588 list_add_tail(&res->tracking, &dlm->tracking_list);
cbe355f5 589 spin_unlock(&dlm->track_lock);
29576f8b 590
6714d8e8 591 memset(res->lvb, 0, DLM_LVB_LEN);
ba2bf218 592 memset(res->refmap, 0, sizeof(res->refmap));
6714d8e8
KH		 593}
594
595struct dlm_lock_resource *dlm_new_lockres(struct dlm_ctxt *dlm,
596 const char *name,
597 unsigned int namelen)
598{
724bdca9 599 struct dlm_lock_resource *res = NULL;
6714d8e8 600
3914ed0c 601 res = kmem_cache_zalloc(dlm_lockres_cache, GFP_NOFS);
6714d8e8 602 if (!res)
724bdca9 603 goto error;
6714d8e8 604
3914ed0c 605 res->lockname.name = kmem_cache_zalloc(dlm_lockname_cache, GFP_NOFS);
724bdca9
SM		 606 if (!res->lockname.name)
607 goto error;
6714d8e8
KH		 608
609 dlm_init_lockres(dlm, res, name, namelen);
610 return res;
724bdca9
SM		 611
612error:
724bdca9
SM		 613 if (res)
614 kmem_cache_free(dlm_lockres_cache, res);
615 return NULL;
6714d8e8
KH		 616}
617
8d400b81
SM		 618void dlm_lockres_set_refmap_bit(struct dlm_ctxt *dlm,
619 struct dlm_lock_resource *res, int bit)
ba2bf218 620{
8d400b81
SM		 621 assert_spin_locked(&res->spinlock);
622
623 mlog(0, "res %.*s, set node %u, %ps()\n", res->lockname.len,
624 res->lockname.name, bit, __builtin_return_address(0));
625
626 set_bit(bit, res->refmap);
627}
628
629void dlm_lockres_clear_refmap_bit(struct dlm_ctxt *dlm,
630 struct dlm_lock_resource *res, int bit)
631{
632 assert_spin_locked(&res->spinlock);
633
634 mlog(0, "res %.*s, clr node %u, %ps()\n", res->lockname.len,
635 res->lockname.name, bit, __builtin_return_address(0));
636
637 clear_bit(bit, res->refmap);
638}
639
5760a97c 640static void __dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm,
8d400b81
SM		 641 struct dlm_lock_resource *res)
642{
ba2bf218 643 res->inflight_locks++;
ff0a522e 644
8d400b81
SM		 645 mlog(0, "%s: res %.*s, inflight++: now %u, %ps()\n", dlm->name,
646 res->lockname.len, res->lockname.name, res->inflight_locks,
647 __builtin_return_address(0));
ba2bf218
KH		 648}
649
5760a97c
JQ		 650void dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm,
651 struct dlm_lock_resource *res)
652{
653 assert_spin_locked(&res->spinlock);
654 __dlm_lockres_grab_inflight_ref(dlm, res);
655}
656
8d400b81
SM		 657void dlm_lockres_drop_inflight_ref(struct dlm_ctxt *dlm,
658 struct dlm_lock_resource *res)
ba2bf218
KH		 659{
660 assert_spin_locked(&res->spinlock);
661
662 BUG_ON(res->inflight_locks == 0);
8d400b81 663
ba2bf218 664 res->inflight_locks--;
ff0a522e 665
8d400b81
SM		 666 mlog(0, "%s: res %.*s, inflight--: now %u, %ps()\n", dlm->name,
667 res->lockname.len, res->lockname.name, res->inflight_locks,
668 __builtin_return_address(0));
669
ba2bf218
KH		 670 wake_up(&res->wq);
671}
672
ac4fef4d
X		 673void __dlm_lockres_grab_inflight_worker(struct dlm_ctxt *dlm,
674 struct dlm_lock_resource *res)
675{
676 assert_spin_locked(&res->spinlock);
677 res->inflight_assert_workers++;
678 mlog(0, "%s:%.*s: inflight assert worker++: now %u\n",
679 dlm->name, res->lockname.len, res->lockname.name,
680 res->inflight_assert_workers);
681}
682
ac4fef4d
X		 683static void __dlm_lockres_drop_inflight_worker(struct dlm_ctxt *dlm,
684 struct dlm_lock_resource *res)
685{
686 assert_spin_locked(&res->spinlock);
687 BUG_ON(res->inflight_assert_workers == 0);
688 res->inflight_assert_workers--;
689 mlog(0, "%s:%.*s: inflight assert worker--: now %u\n",
690 dlm->name, res->lockname.len, res->lockname.name,
691 res->inflight_assert_workers);
692}
693
694static void dlm_lockres_drop_inflight_worker(struct dlm_ctxt *dlm,
695 struct dlm_lock_resource *res)
696{
697 spin_lock(&res->spinlock);
698 __dlm_lockres_drop_inflight_worker(dlm, res);
699 spin_unlock(&res->spinlock);
700}
701
6714d8e8
KH		 702/*
703 * lookup a lock resource by name.
704 * may already exist in the hashtable.
705 * lockid is null terminated
706 *
707 * if not, allocate enough for the lockres and for
708 * the temporary structure used in doing the mastering.
709 *
710 * also, do a lookup in the dlm->master_list to see
711 * if another node has begun mastering the same lock.
712 * if so, there should be a block entry in there
713 * for this name, and we should *not* attempt to master
714 * the lock here. need to wait around for that node
715 * to assert_master (or die).
716 *
717 */
718struct dlm_lock_resource * dlm_get_lock_resource(struct dlm_ctxt *dlm,
719 const char *lockid,
3384f3df 720 int namelen,
6714d8e8
KH		 721 int flags)
722{
723 struct dlm_lock_resource *tmpres=NULL, *res=NULL;
724 struct dlm_master_list_entry *mle = NULL;
725 struct dlm_master_list_entry *alloc_mle = NULL;
726 int blocked = 0;
727 int ret, nodenum;
728 struct dlm_node_iter iter;
3384f3df 729 unsigned int hash;
6714d8e8 730 int tries = 0;
c03872f5 731 int bit, wait_on_recovery = 0;
6714d8e8
KH		 732
733 BUG_ON(!lockid);
734
a3d33291 735 hash = dlm_lockid_hash(lockid, namelen);
6714d8e8
KH		 736
737 mlog(0, "get lockres %s (len %d)\n", lockid, namelen);
738
739lookup:
740 spin_lock(&dlm->spinlock);
ba2bf218 741 tmpres = __dlm_lookup_lockres_full(dlm, lockid, namelen, hash);
6714d8e8 742 if (tmpres) {
7b791d68 743 spin_unlock(&dlm->spinlock);
ba2bf218 744 spin_lock(&tmpres->spinlock);
b1432a2a
JB		 745
746 /*
747 * Right after dlm spinlock was released, dlm_thread could have
748 * purged the lockres. Check if lockres got unhashed. If so
749 * start over.
750 */
751 if (hlist_unhashed(&tmpres->hash_node)) {
752 spin_unlock(&tmpres->spinlock);
753 dlm_lockres_put(tmpres);
754 tmpres = NULL;
755 goto lookup;
756 }
757
ff0a522e 758 /* Wait on the thread that is mastering the resource */
7b791d68
SM		 759 if (tmpres->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
760 __dlm_wait_on_lockres(tmpres);
761 BUG_ON(tmpres->owner == DLM_LOCK_RES_OWNER_UNKNOWN);
ff0a522e
SM		 762 spin_unlock(&tmpres->spinlock);
763 dlm_lockres_put(tmpres);
764 tmpres = NULL;
765 goto lookup;
7b791d68
SM		 766 }
767
ff0a522e
SM		 768 /* Wait on the resource purge to complete before continuing */
769 if (tmpres->state & DLM_LOCK_RES_DROPPING_REF) {
770 BUG_ON(tmpres->owner == dlm->node_num);
771 __dlm_wait_on_lockres_flags(tmpres,
772 DLM_LOCK_RES_DROPPING_REF);
ba2bf218
KH		 773 spin_unlock(&tmpres->spinlock);
774 dlm_lockres_put(tmpres);
775 tmpres = NULL;
776 goto lookup;
777 }
778
ff0a522e
SM		 779 /* Grab inflight ref to pin the resource */
780 dlm_lockres_grab_inflight_ref(dlm, tmpres);
781
782 spin_unlock(&tmpres->spinlock);
f57a22dd
YJ		 783 if (res) {
784 spin_lock(&dlm->track_lock);
785 if (!list_empty(&res->tracking))
786 list_del_init(&res->tracking);
787 else
788 mlog(ML_ERROR, "Resource %.*s not "
789 "on the Tracking list\n",
790 res->lockname.len,
791 res->lockname.name);
792 spin_unlock(&dlm->track_lock);
6714d8e8 793 dlm_lockres_put(res);
f57a22dd 794 }
6714d8e8
KH		 795 res = tmpres;
796 goto leave;
797 }
798
799 if (!res) {
800 spin_unlock(&dlm->spinlock);
801 mlog(0, "allocating a new resource\n");
802 /* nothing found and we need to allocate one. */
3914ed0c 803 alloc_mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
6714d8e8
KH		 804 if (!alloc_mle)
805 goto leave;
806 res = dlm_new_lockres(dlm, lockid, namelen);
807 if (!res)
808 goto leave;
809 goto lookup;
810 }
811
812 mlog(0, "no lockres found, allocated our own: %p\n", res);
813
814 if (flags & LKM_LOCAL) {
815 /* caller knows it's safe to assume it's not mastered elsewhere
816 * DONE! return right away */
817 spin_lock(&res->spinlock);
818 dlm_change_lockres_owner(dlm, res, dlm->node_num);
819 __dlm_insert_lockres(dlm, res);
ba2bf218 820 dlm_lockres_grab_inflight_ref(dlm, res);
6714d8e8
KH		 821 spin_unlock(&res->spinlock);
822 spin_unlock(&dlm->spinlock);
823 /* lockres still marked IN_PROGRESS */
824 goto wake_waiters;
825 }
826
827 /* check master list to see if another node has started mastering it */
828 spin_lock(&dlm->master_lock);
829
830 /* if we found a block, wait for lock to be mastered by another node */
831 blocked = dlm_find_mle(dlm, &mle, (char *)lockid, namelen);
832 if (blocked) {
ba2bf218 833 int mig;
6714d8e8
KH		 834 if (mle->type == DLM_MLE_MASTER) {
835 mlog(ML_ERROR, "master entry for nonexistent lock!\n");
836 BUG();
ba2bf218
KH		 837 }
838 mig = (mle->type == DLM_MLE_MIGRATION);
839 /* if there is a migration in progress, let the migration
840 * finish before continuing. we can wait for the absence
841 * of the MIGRATION mle: either the migrate finished or
842 * one of the nodes died and the mle was cleaned up.
843 * if there is a BLOCK here, but it already has a master
844 * set, we are too late. the master does not have a ref
845 * for us in the refmap. detach the mle and drop it.
846 * either way, go back to the top and start over. */
847 if (mig || mle->master != O2NM_MAX_NODES) {
848 BUG_ON(mig && mle->master == dlm->node_num);
849 /* we arrived too late. the master does not
850 * have a ref for us. retry. */
851 mlog(0, "%s:%.*s: late on %s\n",
852 dlm->name, namelen, lockid,
853 mig ? "MIGRATION" : "BLOCK");
6714d8e8 854 spin_unlock(&dlm->master_lock);
6714d8e8
KH		 855 spin_unlock(&dlm->spinlock);
856
857 /* master is known, detach */
ba2bf218
KH		 858 if (!mig)
859 dlm_mle_detach_hb_events(dlm, mle);
6714d8e8
KH		 860 dlm_put_mle(mle);
861 mle = NULL;
25985edc 862 /* this is lame, but we can't wait on either
ba2bf218
KH		 863 * the mle or lockres waitqueue here */
864 if (mig)
865 msleep(100);
866 goto lookup;
6714d8e8
KH		 867 }
868 } else {
869 /* go ahead and try to master lock on this node */
870 mle = alloc_mle;
871 /* make sure this does not get freed below */
872 alloc_mle = NULL;
873 dlm_init_mle(mle, DLM_MLE_MASTER, dlm, res, NULL, 0);
874 set_bit(dlm->node_num, mle->maybe_map);
1c084577 875 __dlm_insert_mle(dlm, mle);
c03872f5
KH		 876
877 /* still holding the dlm spinlock, check the recovery map
2bd63216 878 * to see if there are any nodes that still need to be
c03872f5
KH		 879 * considered. these will not appear in the mle nodemap
880 * but they might own this lockres. wait on them. */
881 bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0);
882 if (bit < O2NM_MAX_NODES) {
8decab3c
SM		 883 mlog(0, "%s: res %.*s, At least one node (%d) "
884 "to recover before lock mastery can begin\n",
c03872f5
KH		 885 dlm->name, namelen, (char *)lockid, bit);
886 wait_on_recovery = 1;
887 }
6714d8e8
KH		 888 }
889
890 /* at this point there is either a DLM_MLE_BLOCK or a
891 * DLM_MLE_MASTER on the master list, so it's safe to add the
892 * lockres to the hashtable. anyone who finds the lock will
893 * still have to wait on the IN_PROGRESS. */
894
895 /* finally add the lockres to its hash bucket */
896 __dlm_insert_lockres(dlm, res);
8d400b81 897
5760a97c
JQ		 898 /* since this lockres is new it doesn't not require the spinlock */
899 __dlm_lockres_grab_inflight_ref(dlm, res);
ba2bf218 900
6714d8e8
KH		 901 /* get an extra ref on the mle in case this is a BLOCK
902 * if so, the creator of the BLOCK may try to put the last
903 * ref at this time in the assert master handler, so we
904 * need an extra one to keep from a bad ptr deref. */
a2bf0477 905 dlm_get_mle_inuse(mle);
6714d8e8
KH		 906 spin_unlock(&dlm->master_lock);
907 spin_unlock(&dlm->spinlock);
908
e7e69eb3 909redo_request:
c03872f5
KH		 910 while (wait_on_recovery) {
911 /* any cluster changes that occurred after dropping the
912 * dlm spinlock would be detectable be a change on the mle,
913 * so we only need to clear out the recovery map once. */
914 if (dlm_is_recovery_lock(lockid, namelen)) {
8decab3c
SM		 915 mlog(0, "%s: Recovery map is not empty, but must "
916 "master $RECOVERY lock now\n", dlm->name);
c03872f5
KH		 917 if (!dlm_pre_master_reco_lockres(dlm, res))
918 wait_on_recovery = 0;
919 else {
920 mlog(0, "%s: waiting 500ms for heartbeat state "
921 "change\n", dlm->name);
922 msleep(500);
923 }
924 continue;
2bd63216 925 }
c03872f5
KH		 926
927 dlm_kick_recovery_thread(dlm);
aa087b84 928 msleep(1000);
c03872f5
KH		 929 dlm_wait_for_recovery(dlm);
930
931 spin_lock(&dlm->spinlock);
932 bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0);
933 if (bit < O2NM_MAX_NODES) {
8decab3c
SM		 934 mlog(0, "%s: res %.*s, At least one node (%d) "
935 "to recover before lock mastery can begin\n",
c03872f5
KH		 936 dlm->name, namelen, (char *)lockid, bit);
937 wait_on_recovery = 1;
938 } else
939 wait_on_recovery = 0;
940 spin_unlock(&dlm->spinlock);
b7084ab5
KH		 941
942 if (wait_on_recovery)
943 dlm_wait_for_node_recovery(dlm, bit, 10000);
c03872f5
KH		 944 }
945
6714d8e8
KH		 946 /* must wait for lock to be mastered elsewhere */
947 if (blocked)
948 goto wait;
949
6714d8e8
KH		 950 ret = -EINVAL;
951 dlm_node_iter_init(mle->vote_map, &iter);
952 while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
ba2bf218 953 ret = dlm_do_master_request(res, mle, nodenum);
6714d8e8
KH		 954 if (ret < 0)
955 mlog_errno(ret);
956 if (mle->master != O2NM_MAX_NODES) {
957 /* found a master ! */
9c6510a5
KH		 958 if (mle->master <= nodenum)
959 break;
960 /* if our master request has not reached the master
961 * yet, keep going until it does. this is how the
962 * master will know that asserts are needed back to
963 * the lower nodes. */
8decab3c
SM		 964 mlog(0, "%s: res %.*s, Requests only up to %u but "
965 "master is %u, keep going\n", dlm->name, namelen,
9c6510a5 966 lockid, nodenum, mle->master);
6714d8e8
KH		 967 }
968 }
969
970wait:
971 /* keep going until the response map includes all nodes */
972 ret = dlm_wait_for_lock_mastery(dlm, res, mle, &blocked);
973 if (ret < 0) {
e7e69eb3 974 wait_on_recovery = 1;
8decab3c
SM		 975 mlog(0, "%s: res %.*s, Node map changed, redo the master "
976 "request now, blocked=%d\n", dlm->name, res->lockname.len,
6714d8e8
KH		 977 res->lockname.name, blocked);
978 if (++tries > 20) {
8decab3c
SM		 979 mlog(ML_ERROR, "%s: res %.*s, Spinning on "
980 "dlm_wait_for_lock_mastery, blocked = %d\n",
2bd63216 981 dlm->name, res->lockname.len,
6714d8e8
KH		 982 res->lockname.name, blocked);
983 dlm_print_one_lock_resource(res);
8a9343fa 984 dlm_print_one_mle(mle);
6714d8e8
KH		 985 tries = 0;
986 }
987 goto redo_request;
988 }
989
8decab3c
SM		 990 mlog(0, "%s: res %.*s, Mastered by %u\n", dlm->name, res->lockname.len,
991 res->lockname.name, res->owner);
6714d8e8
KH		 992 /* make sure we never continue without this */
993 BUG_ON(res->owner == O2NM_MAX_NODES);
994
995 /* master is known, detach if not already detached */
996 dlm_mle_detach_hb_events(dlm, mle);
997 dlm_put_mle(mle);
998 /* put the extra ref */
a2bf0477 999 dlm_put_mle_inuse(mle);
6714d8e8
KH		 1000
1001wake_waiters:
1002 spin_lock(&res->spinlock);
1003 res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
1004 spin_unlock(&res->spinlock);
1005 wake_up(&res->wq);
1006
1007leave:
1008 /* need to free the unused mle */
1009 if (alloc_mle)
1010 kmem_cache_free(dlm_mle_cache, alloc_mle);
1011
1012 return res;
1013}
1014
1015
1016#define DLM_MASTERY_TIMEOUT_MS 5000
1017
1018static int dlm_wait_for_lock_mastery(struct dlm_ctxt *dlm,
1019 struct dlm_lock_resource *res,
1020 struct dlm_master_list_entry *mle,
1021 int *blocked)
1022{
1023 u8 m;
1024 int ret, bit;
1025 int map_changed, voting_done;
1026 int assert, sleep;
1027
1028recheck:
1029 ret = 0;
1030 assert = 0;
1031
1032 /* check if another node has already become the owner */
1033 spin_lock(&res->spinlock);
1034 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
9c6510a5
KH		 1035 mlog(0, "%s:%.*s: owner is suddenly %u\n", dlm->name,
1036 res->lockname.len, res->lockname.name, res->owner);
6714d8e8 1037 spin_unlock(&res->spinlock);
9c6510a5
KH		 1038 /* this will cause the master to re-assert across
1039 * the whole cluster, freeing up mles */
588e0090 1040 if (res->owner != dlm->node_num) {
ba2bf218 1041 ret = dlm_do_master_request(res, mle, res->owner);
588e0090
KH		 1042 if (ret < 0) {
1043 /* give recovery a chance to run */
1044 mlog(ML_ERROR, "link to %u went down?: %d\n", res->owner, ret);
1045 msleep(500);
1046 goto recheck;
1047 }
9c6510a5
KH		 1048 }
1049 ret = 0;
6714d8e8
KH		 1050 goto leave;
1051 }
1052 spin_unlock(&res->spinlock);
1053
1054 spin_lock(&mle->spinlock);
1055 m = mle->master;
1056 map_changed = (memcmp(mle->vote_map, mle->node_map,
1057 sizeof(mle->vote_map)) != 0);
1058 voting_done = (memcmp(mle->vote_map, mle->response_map,
1059 sizeof(mle->vote_map)) == 0);
1060
1061 /* restart if we hit any errors */
1062 if (map_changed) {
1063 int b;
1064 mlog(0, "%s: %.*s: node map changed, restarting\n",
1065 dlm->name, res->lockname.len, res->lockname.name);
1066 ret = dlm_restart_lock_mastery(dlm, res, mle, *blocked);
1067 b = (mle->type == DLM_MLE_BLOCK);
1068 if ((*blocked && !b) || (!*blocked && b)) {
2bd63216 1069 mlog(0, "%s:%.*s: status change: old=%d new=%d\n",
6714d8e8
KH		 1070 dlm->name, res->lockname.len, res->lockname.name,
1071 *blocked, b);
1072 *blocked = b;
1073 }
1074 spin_unlock(&mle->spinlock);
1075 if (ret < 0) {
1076 mlog_errno(ret);
1077 goto leave;
1078 }
1079 mlog(0, "%s:%.*s: restart lock mastery succeeded, "
1080 "rechecking now\n", dlm->name, res->lockname.len,
1081 res->lockname.name);
1082 goto recheck;
aa852354
KH		 1083 } else {
1084 if (!voting_done) {
1085 mlog(0, "map not changed and voting not done "
1086 "for %s:%.*s\n", dlm->name, res->lockname.len,
1087 res->lockname.name);
1088 }
6714d8e8
KH		 1089 }
1090
1091 if (m != O2NM_MAX_NODES) {
1092 /* another node has done an assert!
1093 * all done! */
1094 sleep = 0;
1095 } else {
1096 sleep = 1;
1097 /* have all nodes responded? */
1098 if (voting_done && !*blocked) {
1099 bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0);
1100 if (dlm->node_num <= bit) {
1101 /* my node number is lowest.
1102 * now tell other nodes that I am
1103 * mastering this. */
1104 mle->master = dlm->node_num;
ba2bf218
KH		 1105 /* ref was grabbed in get_lock_resource
1106 * will be dropped in dlmlock_master */
6714d8e8
KH		 1107 assert = 1;
1108 sleep = 0;
1109 }
1110 /* if voting is done, but we have not received
1111 * an assert master yet, we must sleep */
1112 }
1113 }
1114
1115 spin_unlock(&mle->spinlock);
1116
1117 /* sleep if we haven't finished voting yet */
1118 if (sleep) {
1119 unsigned long timeo = msecs_to_jiffies(DLM_MASTERY_TIMEOUT_MS);
6714d8e8
KH		 1120 atomic_set(&mle->woken, 0);
1121 (void)wait_event_timeout(mle->wq,
1122 (atomic_read(&mle->woken) == 1),
1123 timeo);
1124 if (res->owner == O2NM_MAX_NODES) {
ba2bf218
KH		 1125 mlog(0, "%s:%.*s: waiting again\n", dlm->name,
1126 res->lockname.len, res->lockname.name);
6714d8e8
KH		 1127 goto recheck;
1128 }
1129 mlog(0, "done waiting, master is %u\n", res->owner);
1130 ret = 0;
1131 goto leave;
1132 }
1133
1134 ret = 0; /* done */
1135 if (assert) {
1136 m = dlm->node_num;
1137 mlog(0, "about to master %.*s here, this=%u\n",
1138 res->lockname.len, res->lockname.name, m);
ba2bf218 1139 ret = dlm_do_assert_master(dlm, res, mle->vote_map, 0);
6714d8e8
KH		 1140 if (ret) {
1141 /* This is a failure in the network path,
1142 * not in the response to the assert_master
1143 * (any nonzero response is a BUG on this node).
1144 * Most likely a socket just got disconnected
1145 * due to node death. */
1146 mlog_errno(ret);
1147 }
1148 /* no longer need to restart lock mastery.
1149 * all living nodes have been contacted. */
1150 ret = 0;
1151 }
1152
1153 /* set the lockres owner */
1154 spin_lock(&res->spinlock);
ba2bf218
KH		 1155 /* mastery reference obtained either during
1156 * assert_master_handler or in get_lock_resource */
6714d8e8
KH		 1157 dlm_change_lockres_owner(dlm, res, m);
1158 spin_unlock(&res->spinlock);
1159
1160leave:
1161 return ret;
1162}
1163
1164struct dlm_bitmap_diff_iter
1165{
1166 int curnode;
1167 unsigned long *orig_bm;
1168 unsigned long *cur_bm;
1169 unsigned long diff_bm[BITS_TO_LONGS(O2NM_MAX_NODES)];
1170};
1171
1172enum dlm_node_state_change
1173{
1174 NODE_DOWN = -1,
1175 NODE_NO_CHANGE = 0,
1176 NODE_UP
1177};
1178
1179static void dlm_bitmap_diff_iter_init(struct dlm_bitmap_diff_iter *iter,
1180 unsigned long *orig_bm,
1181 unsigned long *cur_bm)
1182{
1183 unsigned long p1, p2;
1184 int i;
1185
1186 iter->curnode = -1;
1187 iter->orig_bm = orig_bm;
1188 iter->cur_bm = cur_bm;
1189
1190 for (i = 0; i < BITS_TO_LONGS(O2NM_MAX_NODES); i++) {
1191 p1 = *(iter->orig_bm + i);
1192 p2 = *(iter->cur_bm + i);
1193 iter->diff_bm[i] = (p1 & ~p2) | (p2 & ~p1);
1194 }
1195}
1196
1197static int dlm_bitmap_diff_iter_next(struct dlm_bitmap_diff_iter *iter,
1198 enum dlm_node_state_change *state)
1199{
1200 int bit;
1201
1202 if (iter->curnode >= O2NM_MAX_NODES)
1203 return -ENOENT;
1204
1205 bit = find_next_bit(iter->diff_bm, O2NM_MAX_NODES,
1206 iter->curnode+1);
1207 if (bit >= O2NM_MAX_NODES) {
1208 iter->curnode = O2NM_MAX_NODES;
1209 return -ENOENT;
1210 }
1211
1212 /* if it was there in the original then this node died */
1213 if (test_bit(bit, iter->orig_bm))
1214 *state = NODE_DOWN;
1215 else
1216 *state = NODE_UP;
1217
1218 iter->curnode = bit;
1219 return bit;
1220}
1221
1222
1223static int dlm_restart_lock_mastery(struct dlm_ctxt *dlm,
1224 struct dlm_lock_resource *res,
1225 struct dlm_master_list_entry *mle,
1226 int blocked)
1227{
1228 struct dlm_bitmap_diff_iter bdi;
1229 enum dlm_node_state_change sc;
1230 int node;
1231 int ret = 0;
1232
1233 mlog(0, "something happened such that the "
1234 "master process may need to be restarted!\n");
1235
1236 assert_spin_locked(&mle->spinlock);
1237
1238 dlm_bitmap_diff_iter_init(&bdi, mle->vote_map, mle->node_map);
1239 node = dlm_bitmap_diff_iter_next(&bdi, &sc);
1240 while (node >= 0) {
1241 if (sc == NODE_UP) {
e2faea4c
KH		 1242 /* a node came up. clear any old vote from
1243 * the response map and set it in the vote map
1244 * then restart the mastery. */
1245 mlog(ML_NOTICE, "node %d up while restarting\n", node);
6714d8e8
KH		 1246
1247 /* redo the master request, but only for the new node */
1248 mlog(0, "sending request to new node\n");
1249 clear_bit(node, mle->response_map);
1250 set_bit(node, mle->vote_map);
1251 } else {
1252 mlog(ML_ERROR, "node down! %d\n", node);
6714d8e8
KH		 1253 if (blocked) {
1254 int lowest = find_next_bit(mle->maybe_map,
1255 O2NM_MAX_NODES, 0);
1256
1257 /* act like it was never there */
1258 clear_bit(node, mle->maybe_map);
1259
e7e69eb3
KH		 1260 if (node == lowest) {
1261 mlog(0, "expected master %u died"
1262 " while this node was blocked "
1263 "waiting on it!\n", node);
1264 lowest = find_next_bit(mle->maybe_map,
1265 O2NM_MAX_NODES,
1266 lowest+1);
1267 if (lowest < O2NM_MAX_NODES) {
1268 mlog(0, "%s:%.*s:still "
1269 "blocked. waiting on %u "
1270 "now\n", dlm->name,
1271 res->lockname.len,
1272 res->lockname.name,
1273 lowest);
1274 } else {
1275 /* mle is an MLE_BLOCK, but
1276 * there is now nothing left to
1277 * block on. we need to return
1278 * all the way back out and try
1279 * again with an MLE_MASTER.
1280 * dlm_do_local_recovery_cleanup
1281 * has already run, so the mle
1282 * refcount is ok */
1283 mlog(0, "%s:%.*s: no "
1284 "longer blocking. try to "
1285 "master this here\n",
1286 dlm->name,
1287 res->lockname.len,
1288 res->lockname.name);
1289 mle->type = DLM_MLE_MASTER;
7141514b 1290 mle->mleres = res;
e7e69eb3 1291 }
6714d8e8 1292 }
6714d8e8
KH		 1293 }
1294
e7e69eb3
KH		 1295 /* now blank out everything, as if we had never
1296 * contacted anyone */
1297 memset(mle->maybe_map, 0, sizeof(mle->maybe_map));
1298 memset(mle->response_map, 0, sizeof(mle->response_map));
1299 /* reset the vote_map to the current node_map */
1300 memcpy(mle->vote_map, mle->node_map,
1301 sizeof(mle->node_map));
1302 /* put myself into the maybe map */
1303 if (mle->type != DLM_MLE_BLOCK)
1304 set_bit(dlm->node_num, mle->maybe_map);
6714d8e8
KH		 1305 }
1306 ret = -EAGAIN;
6714d8e8
KH		 1307 node = dlm_bitmap_diff_iter_next(&bdi, &sc);
1308 }
1309 return ret;
1310}
1311
1312
1313/*
1314 * DLM_MASTER_REQUEST_MSG
1315 *
1316 * returns: 0 on success,
1317 * -errno on a network error
1318 *
1319 * on error, the caller should assume the target node is "dead"
1320 *
1321 */
1322
ba2bf218
KH		 1323static int dlm_do_master_request(struct dlm_lock_resource *res,
1324 struct dlm_master_list_entry *mle, int to)
6714d8e8
KH		 1325{
1326 struct dlm_ctxt *dlm = mle->dlm;
1327 struct dlm_master_request request;
1328 int ret, response=0, resend;
1329
1330 memset(&request, 0, sizeof(request));
1331 request.node_idx = dlm->node_num;
1332
1333 BUG_ON(mle->type == DLM_MLE_MIGRATION);
1334
7141514b
SM		 1335 request.namelen = (u8)mle->mnamelen;
1336 memcpy(request.name, mle->mname, request.namelen);
6714d8e8
KH		 1337
1338again:
1339 ret = o2net_send_message(DLM_MASTER_REQUEST_MSG, dlm->key, &request,
1340 sizeof(request), to, &response);
1341 if (ret < 0) {
1342 if (ret == -ESRCH) {
1343 /* should never happen */
1344 mlog(ML_ERROR, "TCP stack not ready!\n");
1345 BUG();
1346 } else if (ret == -EINVAL) {
1347 mlog(ML_ERROR, "bad args passed to o2net!\n");
1348 BUG();
1349 } else if (ret == -ENOMEM) {
1350 mlog(ML_ERROR, "out of memory while trying to send "
1351 "network message! retrying\n");
1352 /* this is totally crude */
1353 msleep(50);
1354 goto again;
1355 } else if (!dlm_is_host_down(ret)) {
1356 /* not a network error. bad. */
1357 mlog_errno(ret);
1358 mlog(ML_ERROR, "unhandled error!");
1359 BUG();
1360 }
1361 /* all other errors should be network errors,
1362 * and likely indicate node death */
1363 mlog(ML_ERROR, "link to %d went down!\n", to);
1364 goto out;
1365 }
1366
1367 ret = 0;
1368 resend = 0;
1369 spin_lock(&mle->spinlock);
1370 switch (response) {
1371 case DLM_MASTER_RESP_YES:
1372 set_bit(to, mle->response_map);
1373 mlog(0, "node %u is the master, response=YES\n", to);
ba2bf218
KH		 1374 mlog(0, "%s:%.*s: master node %u now knows I have a "
1375 "reference\n", dlm->name, res->lockname.len,
1376 res->lockname.name, to);
6714d8e8
KH		 1377 mle->master = to;
1378 break;
1379 case DLM_MASTER_RESP_NO:
1380 mlog(0, "node %u not master, response=NO\n", to);
1381 set_bit(to, mle->response_map);
1382 break;
1383 case DLM_MASTER_RESP_MAYBE:
1384 mlog(0, "node %u not master, response=MAYBE\n", to);
1385 set_bit(to, mle->response_map);
1386 set_bit(to, mle->maybe_map);
1387 break;
1388 case DLM_MASTER_RESP_ERROR:
1389 mlog(0, "node %u hit an error, resending\n", to);
1390 resend = 1;
1391 response = 0;
1392 break;
1393 default:
1394 mlog(ML_ERROR, "bad response! %u\n", response);
1395 BUG();
1396 }
1397 spin_unlock(&mle->spinlock);
1398 if (resend) {
1399 /* this is also totally crude */
1400 msleep(50);
1401 goto again;
1402 }
1403
1404out:
1405 return ret;
1406}
1407
1408/*
1409 * locks that can be taken here:
1410 * dlm->spinlock
1411 * res->spinlock
1412 * mle->spinlock
1413 * dlm->master_list
1414 *
1415 * if possible, TRIM THIS DOWN!!!
1416 */
d74c9803
KH		 1417int dlm_master_request_handler(struct o2net_msg *msg, u32 len, void *data,
1418 void **ret_data)
6714d8e8
KH		 1419{
1420 u8 response = DLM_MASTER_RESP_MAYBE;
1421 struct dlm_ctxt *dlm = data;
9c6510a5 1422 struct dlm_lock_resource *res = NULL;
6714d8e8
KH		 1423 struct dlm_master_request *request = (struct dlm_master_request *) msg->buf;
1424 struct dlm_master_list_entry *mle = NULL, *tmpmle = NULL;
1425 char *name;
a3d33291 1426 unsigned int namelen, hash;
6714d8e8
KH		 1427 int found, ret;
1428 int set_maybe;
9c6510a5 1429 int dispatch_assert = 0;
012572d4 1430 int dispatched = 0;
6714d8e8
KH		 1431
1432 if (!dlm_grab(dlm))
1433 return DLM_MASTER_RESP_NO;
1434
1435 if (!dlm_domain_fully_joined(dlm)) {
1436 response = DLM_MASTER_RESP_NO;
1437 goto send_response;
1438 }
1439
1440 name = request->name;
1441 namelen = request->namelen;
a3d33291 1442 hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 1443
1444 if (namelen > DLM_LOCKID_NAME_MAX) {
1445 response = DLM_IVBUFLEN;
1446 goto send_response;
1447 }
1448
1449way_up_top:
1450 spin_lock(&dlm->spinlock);
a3d33291 1451 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
6714d8e8
KH		 1452 if (res) {
1453 spin_unlock(&dlm->spinlock);
1454
1455 /* take care of the easy cases up front */
1456 spin_lock(&res->spinlock);
cb79662b
SE		 1457
1458 /*
1459 * Right after dlm spinlock was released, dlm_thread could have
1460 * purged the lockres. Check if lockres got unhashed. If so
1461 * start over.
1462 */
1463 if (hlist_unhashed(&res->hash_node)) {
1464 spin_unlock(&res->spinlock);
1465 dlm_lockres_put(res);
1466 goto way_up_top;
1467 }
1468
1cd04dbe
KH		 1469 if (res->state & (DLM_LOCK_RES_RECOVERING|
1470 DLM_LOCK_RES_MIGRATING)) {
6714d8e8
KH		 1471 spin_unlock(&res->spinlock);
1472 mlog(0, "returning DLM_MASTER_RESP_ERROR since res is "
1cd04dbe 1473 "being recovered/migrated\n");
6714d8e8
KH		 1474 response = DLM_MASTER_RESP_ERROR;
1475 if (mle)
1476 kmem_cache_free(dlm_mle_cache, mle);
1477 goto send_response;
1478 }
1479
1480 if (res->owner == dlm->node_num) {
8d400b81 1481 dlm_lockres_set_refmap_bit(dlm, res, request->node_idx);
6714d8e8 1482 spin_unlock(&res->spinlock);
6714d8e8
KH		 1483 response = DLM_MASTER_RESP_YES;
1484 if (mle)
1485 kmem_cache_free(dlm_mle_cache, mle);
1486
1487 /* this node is the owner.
1488 * there is some extra work that needs to
1489 * happen now. the requesting node has
1490 * caused all nodes up to this one to
1491 * create mles. this node now needs to
1492 * go back and clean those up. */
9c6510a5 1493 dispatch_assert = 1;
6714d8e8
KH		 1494 goto send_response;
1495 } else if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
1496 spin_unlock(&res->spinlock);
1497 // mlog(0, "node %u is the master\n", res->owner);
1498 response = DLM_MASTER_RESP_NO;
1499 if (mle)
1500 kmem_cache_free(dlm_mle_cache, mle);
1501 goto send_response;
1502 }
1503
1504 /* ok, there is no owner. either this node is
1505 * being blocked, or it is actively trying to
1506 * master this lock. */
1507 if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) {
1508 mlog(ML_ERROR, "lock with no owner should be "
1509 "in-progress!\n");
1510 BUG();
1511 }
1512
1513 // mlog(0, "lockres is in progress...\n");
1514 spin_lock(&dlm->master_lock);
1515 found = dlm_find_mle(dlm, &tmpmle, name, namelen);
1516 if (!found) {
1517 mlog(ML_ERROR, "no mle found for this lock!\n");
1518 BUG();
1519 }
1520 set_maybe = 1;
1521 spin_lock(&tmpmle->spinlock);
1522 if (tmpmle->type == DLM_MLE_BLOCK) {
1523 // mlog(0, "this node is waiting for "
1524 // "lockres to be mastered\n");
1525 response = DLM_MASTER_RESP_NO;
1526 } else if (tmpmle->type == DLM_MLE_MIGRATION) {
1527 mlog(0, "node %u is master, but trying to migrate to "
1528 "node %u.\n", tmpmle->master, tmpmle->new_master);
1529 if (tmpmle->master == dlm->node_num) {
6714d8e8
KH		 1530 mlog(ML_ERROR, "no owner on lockres, but this "
1531 "node is trying to migrate it to %u?!\n",
1532 tmpmle->new_master);
1533 BUG();
1534 } else {
1535 /* the real master can respond on its own */
1536 response = DLM_MASTER_RESP_NO;
1537 }
1538 } else if (tmpmle->master != DLM_LOCK_RES_OWNER_UNKNOWN) {
1539 set_maybe = 0;
9c6510a5 1540 if (tmpmle->master == dlm->node_num) {
6714d8e8 1541 response = DLM_MASTER_RESP_YES;
9c6510a5
KH		 1542 /* this node will be the owner.
1543 * go back and clean the mles on any
1544 * other nodes */
1545 dispatch_assert = 1;
8d400b81
SM		 1546 dlm_lockres_set_refmap_bit(dlm, res,
1547 request->node_idx);
9c6510a5 1548 } else
6714d8e8
KH		 1549 response = DLM_MASTER_RESP_NO;
1550 } else {
1551 // mlog(0, "this node is attempting to "
1552 // "master lockres\n");
1553 response = DLM_MASTER_RESP_MAYBE;
1554 }
1555 if (set_maybe)
1556 set_bit(request->node_idx, tmpmle->maybe_map);
1557 spin_unlock(&tmpmle->spinlock);
1558
1559 spin_unlock(&dlm->master_lock);
1560 spin_unlock(&res->spinlock);
1561
1562 /* keep the mle attached to heartbeat events */
1563 dlm_put_mle(tmpmle);
1564 if (mle)
1565 kmem_cache_free(dlm_mle_cache, mle);
1566 goto send_response;
1567 }
1568
1569 /*
1570 * lockres doesn't exist on this node
1571 * if there is an MLE_BLOCK, return NO
1572 * if there is an MLE_MASTER, return MAYBE
1573 * otherwise, add an MLE_BLOCK, return NO
1574 */
1575 spin_lock(&dlm->master_lock);
1576 found = dlm_find_mle(dlm, &tmpmle, name, namelen);
1577 if (!found) {
1578 /* this lockid has never been seen on this node yet */
1579 // mlog(0, "no mle found\n");
1580 if (!mle) {
1581 spin_unlock(&dlm->master_lock);
1582 spin_unlock(&dlm->spinlock);
1583
3914ed0c 1584 mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
6714d8e8 1585 if (!mle) {
6714d8e8 1586 response = DLM_MASTER_RESP_ERROR;
9c6510a5 1587 mlog_errno(-ENOMEM);
6714d8e8
KH		 1588 goto send_response;
1589 }
6714d8e8
KH		 1590 goto way_up_top;
1591 }
1592
1593 // mlog(0, "this is second time thru, already allocated, "
1594 // "add the block.\n");
41b8c8a1 1595 dlm_init_mle(mle, DLM_MLE_BLOCK, dlm, NULL, name, namelen);
6714d8e8 1596 set_bit(request->node_idx, mle->maybe_map);
1c084577 1597 __dlm_insert_mle(dlm, mle);
6714d8e8
KH		 1598 response = DLM_MASTER_RESP_NO;
1599 } else {
6714d8e8 1600 spin_lock(&tmpmle->spinlock);
9c6510a5
KH		 1601 if (tmpmle->master == dlm->node_num) {
1602 mlog(ML_ERROR, "no lockres, but an mle with this node as master!\n");
1603 BUG();
1604 }
6714d8e8
KH		 1605 if (tmpmle->type == DLM_MLE_BLOCK)
1606 response = DLM_MASTER_RESP_NO;
1607 else if (tmpmle->type == DLM_MLE_MIGRATION) {
1608 mlog(0, "migration mle was found (%u->%u)\n",
1609 tmpmle->master, tmpmle->new_master);
6714d8e8
KH		 1610 /* real master can respond on its own */
1611 response = DLM_MASTER_RESP_NO;
9c6510a5
KH		 1612 } else
1613 response = DLM_MASTER_RESP_MAYBE;
aa7b5859 1614 set_bit(request->node_idx, tmpmle->maybe_map);
6714d8e8
KH		 1615 spin_unlock(&tmpmle->spinlock);
1616 }
1617 spin_unlock(&dlm->master_lock);
1618 spin_unlock(&dlm->spinlock);
1619
1620 if (found) {
1621 /* keep the mle attached to heartbeat events */
1622 dlm_put_mle(tmpmle);
1623 }
1624send_response:
b31cfc02
SM		 1625 /*
1626 * __dlm_lookup_lockres() grabbed a reference to this lockres.
1627 * The reference is released by dlm_assert_master_worker() under
1628 * the call to dlm_dispatch_assert_master(). If
1629 * dlm_assert_master_worker() isn't called, we drop it here.
1630 */
9c6510a5 1631 if (dispatch_assert) {
9c6510a5
KH		 1632 mlog(0, "%u is the owner of %.*s, cleaning everyone else\n",
1633 dlm->node_num, res->lockname.len, res->lockname.name);
1e589581 1634 spin_lock(&res->spinlock);
2bd63216 1635 ret = dlm_dispatch_assert_master(dlm, res, 0, request->node_idx,
9c6510a5
KH		 1636 DLM_ASSERT_MASTER_MLE_CLEANUP);
1637 if (ret < 0) {
1638 mlog(ML_ERROR, "failed to dispatch assert master work\n");
1639 response = DLM_MASTER_RESP_ERROR;
b67de018 1640 spin_unlock(&res->spinlock);
b31cfc02 1641 dlm_lockres_put(res);
012572d4
JQ		 1642 } else {
1643 dispatched = 1;
1e589581 1644 __dlm_lockres_grab_inflight_worker(dlm, res);
b67de018 1645 spin_unlock(&res->spinlock);
012572d4 1646 }
b31cfc02
SM		 1647 } else {
1648 if (res)
1649 dlm_lockres_put(res);
9c6510a5
KH		 1650 }
1651
012572d4
JQ		 1652 if (!dispatched)
1653 dlm_put(dlm);
6714d8e8
KH		 1654 return response;
1655}
1656
1657/*
1658 * DLM_ASSERT_MASTER_MSG
1659 */
1660
1661
1662/*
1663 * NOTE: this can be used for debugging
1664 * can periodically run all locks owned by this node
1665 * and re-assert across the cluster...
1666 */
05488bbe
AB		 1667static int dlm_do_assert_master(struct dlm_ctxt *dlm,
1668 struct dlm_lock_resource *res,
1669 void *nodemap, u32 flags)
6714d8e8
KH		 1670{
1671 struct dlm_assert_master assert;
1672 int to, tmpret;
1673 struct dlm_node_iter iter;
1674 int ret = 0;
9c6510a5 1675 int reassert;
ba2bf218
KH		 1676 const char *lockname = res->lockname.name;
1677 unsigned int namelen = res->lockname.len;
6714d8e8
KH		 1678
1679 BUG_ON(namelen > O2NM_MAX_NAME_LEN);
f3f85464
SM		 1680
1681 spin_lock(&res->spinlock);
1682 res->state |= DLM_LOCK_RES_SETREF_INPROG;
1683 spin_unlock(&res->spinlock);
1684
9c6510a5
KH		 1685again:
1686 reassert = 0;
6714d8e8
KH		 1687
1688 /* note that if this nodemap is empty, it returns 0 */
1689 dlm_node_iter_init(nodemap, &iter);
1690 while ((to = dlm_node_iter_next(&iter)) >= 0) {
1691 int r = 0;
a9ee4c8a
KH		 1692 struct dlm_master_list_entry *mle = NULL;
1693
6714d8e8
KH		 1694 mlog(0, "sending assert master to %d (%.*s)\n", to,
1695 namelen, lockname);
1696 memset(&assert, 0, sizeof(assert));
1697 assert.node_idx = dlm->node_num;
1698 assert.namelen = namelen;
1699 memcpy(assert.name, lockname, namelen);
1700 assert.flags = cpu_to_be32(flags);
1701
1702 tmpret = o2net_send_message(DLM_ASSERT_MASTER_MSG, dlm->key,
1703 &assert, sizeof(assert), to, &r);
1704 if (tmpret < 0) {
a5196ec5
WW		 1705 mlog(ML_ERROR, "Error %d when sending message %u (key "
1706 "0x%x) to node %u\n", tmpret,
1707 DLM_ASSERT_MASTER_MSG, dlm->key, to);
6714d8e8 1708 if (!dlm_is_host_down(tmpret)) {
3b3b84a8 1709 mlog(ML_ERROR, "unhandled error=%d!\n", tmpret);
6714d8e8
KH		 1710 BUG();
1711 }
1712 /* a node died. finish out the rest of the nodes. */
3b3b84a8 1713 mlog(0, "link to %d went down!\n", to);
6714d8e8
KH		 1714 /* any nonzero status return will do */
1715 ret = tmpret;
ba2bf218 1716 r = 0;
6714d8e8
KH		 1717 } else if (r < 0) {
1718 /* ok, something horribly messed. kill thyself. */
1719 mlog(ML_ERROR,"during assert master of %.*s to %u, "
1720 "got %d.\n", namelen, lockname, to, r);
a9ee4c8a
KH		 1721 spin_lock(&dlm->spinlock);
1722 spin_lock(&dlm->master_lock);
1723 if (dlm_find_mle(dlm, &mle, (char *)lockname,
1724 namelen)) {
1725 dlm_print_one_mle(mle);
1726 __dlm_put_mle(mle);
1727 }
1728 spin_unlock(&dlm->master_lock);
1729 spin_unlock(&dlm->spinlock);
6714d8e8 1730 BUG();
ba2bf218
KH		 1731 }
1732
1733 if (r & DLM_ASSERT_RESPONSE_REASSERT &&
1734 !(r & DLM_ASSERT_RESPONSE_MASTERY_REF)) {
1735 mlog(ML_ERROR, "%.*s: very strange, "
1736 "master MLE but no lockres on %u\n",
1737 namelen, lockname, to);
1738 }
1739
1740 if (r & DLM_ASSERT_RESPONSE_REASSERT) {
9c6510a5 1741 mlog(0, "%.*s: node %u create mles on other "
2bd63216 1742 "nodes and requests a re-assert\n",
9c6510a5
KH		 1743 namelen, lockname, to);
1744 reassert = 1;
6714d8e8 1745 }
ba2bf218
KH		 1746 if (r & DLM_ASSERT_RESPONSE_MASTERY_REF) {
1747 mlog(0, "%.*s: node %u has a reference to this "
1748 "lockres, set the bit in the refmap\n",
1749 namelen, lockname, to);
1750 spin_lock(&res->spinlock);
8d400b81 1751 dlm_lockres_set_refmap_bit(dlm, res, to);
ba2bf218
KH		 1752 spin_unlock(&res->spinlock);
1753 }
6714d8e8
KH		 1754 }
1755
9c6510a5
KH		 1756 if (reassert)
1757 goto again;
1758
f3f85464
SM		 1759 spin_lock(&res->spinlock);
1760 res->state &= ~DLM_LOCK_RES_SETREF_INPROG;
1761 spin_unlock(&res->spinlock);
1762 wake_up(&res->wq);
1763
6714d8e8
KH		 1764 return ret;
1765}
1766
1767/*
1768 * locks that can be taken here:
1769 * dlm->spinlock
1770 * res->spinlock
1771 * mle->spinlock
1772 * dlm->master_list
1773 *
1774 * if possible, TRIM THIS DOWN!!!
1775 */
d74c9803
KH		 1776int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data,
1777 void **ret_data)
6714d8e8
KH		 1778{
1779 struct dlm_ctxt *dlm = data;
1780 struct dlm_master_list_entry *mle = NULL;
1781 struct dlm_assert_master *assert = (struct dlm_assert_master *)msg->buf;
1782 struct dlm_lock_resource *res = NULL;
1783 char *name;
a3d33291 1784 unsigned int namelen, hash;
6714d8e8 1785 u32 flags;
ba2bf218 1786 int master_request = 0, have_lockres_ref = 0;
9c6510a5 1787 int ret = 0;
6714d8e8
KH		 1788
1789 if (!dlm_grab(dlm))
1790 return 0;
1791
1792 name = assert->name;
1793 namelen = assert->namelen;
a3d33291 1794 hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 1795 flags = be32_to_cpu(assert->flags);
1796
1797 if (namelen > DLM_LOCKID_NAME_MAX) {
1798 mlog(ML_ERROR, "Invalid name length!");
1799 goto done;
1800 }
1801
1802 spin_lock(&dlm->spinlock);
1803
1804 if (flags)
1805 mlog(0, "assert_master with flags: %u\n", flags);
1806
1807 /* find the MLE */
1808 spin_lock(&dlm->master_lock);
1809 if (!dlm_find_mle(dlm, &mle, name, namelen)) {
1810 /* not an error, could be master just re-asserting */
1811 mlog(0, "just got an assert_master from %u, but no "
1812 "MLE for it! (%.*s)\n", assert->node_idx,
1813 namelen, name);
1814 } else {
1815 int bit = find_next_bit (mle->maybe_map, O2NM_MAX_NODES, 0);
1816 if (bit >= O2NM_MAX_NODES) {
1817 /* not necessarily an error, though less likely.
1818 * could be master just re-asserting. */
aa852354 1819 mlog(0, "no bits set in the maybe_map, but %u "
6714d8e8
KH		 1820 "is asserting! (%.*s)\n", assert->node_idx,
1821 namelen, name);
1822 } else if (bit != assert->node_idx) {
1823 if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) {
1824 mlog(0, "master %u was found, %u should "
1825 "back off\n", assert->node_idx, bit);
1826 } else {
1827 /* with the fix for bug 569, a higher node
1828 * number winning the mastery will respond
1829 * YES to mastery requests, but this node
1830 * had no way of knowing. let it pass. */
aa852354 1831 mlog(0, "%u is the lowest node, "
6714d8e8
KH		 1832 "%u is asserting. (%.*s) %u must "
1833 "have begun after %u won.\n", bit,
1834 assert->node_idx, namelen, name, bit,
1835 assert->node_idx);
1836 }
1837 }
2d1a868c
KH		 1838 if (mle->type == DLM_MLE_MIGRATION) {
1839 if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) {
1840 mlog(0, "%s:%.*s: got cleanup assert"
1841 " from %u for migration\n",
1842 dlm->name, namelen, name,
1843 assert->node_idx);
1844 } else if (!(flags & DLM_ASSERT_MASTER_FINISH_MIGRATION)) {
1845 mlog(0, "%s:%.*s: got unrelated assert"
1846 " from %u for migration, ignoring\n",
1847 dlm->name, namelen, name,
1848 assert->node_idx);
1849 __dlm_put_mle(mle);
1850 spin_unlock(&dlm->master_lock);
1851 spin_unlock(&dlm->spinlock);
1852 goto done;
2bd63216 1853 }
2d1a868c 1854 }
6714d8e8
KH		 1855 }
1856 spin_unlock(&dlm->master_lock);
1857
1858 /* ok everything checks out with the MLE
1859 * now check to see if there is a lockres */
a3d33291 1860 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
6714d8e8
KH		 1861 if (res) {
1862 spin_lock(&res->spinlock);
1863 if (res->state & DLM_LOCK_RES_RECOVERING) {
1864 mlog(ML_ERROR, "%u asserting but %.*s is "
1865 "RECOVERING!\n", assert->node_idx, namelen, name);
1866 goto kill;
1867 }
1868 if (!mle) {
dc2ed195
KH		 1869 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN &&
1870 res->owner != assert->node_idx) {
53ecd25e
SM		 1871 mlog(ML_ERROR, "DIE! Mastery assert from %u, "
1872 "but current owner is %u! (%.*s)\n",
1873 assert->node_idx, res->owner, namelen,
1874 name);
1875 __dlm_print_one_lock_resource(res);
1876 BUG();
6714d8e8
KH		 1877 }
1878 } else if (mle->type != DLM_MLE_MIGRATION) {
1879 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
1880 /* owner is just re-asserting */
1881 if (res->owner == assert->node_idx) {
1882 mlog(0, "owner %u re-asserting on "
1883 "lock %.*s\n", assert->node_idx,
1884 namelen, name);
1885 goto ok;
1886 }
1887 mlog(ML_ERROR, "got assert_master from "
1888 "node %u, but %u is the owner! "
1889 "(%.*s)\n", assert->node_idx,
1890 res->owner, namelen, name);
1891 goto kill;
1892 }
1893 if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) {
1894 mlog(ML_ERROR, "got assert from %u, but lock "
1895 "with no owner should be "
1896 "in-progress! (%.*s)\n",
1897 assert->node_idx,
1898 namelen, name);
1899 goto kill;
1900 }
1901 } else /* mle->type == DLM_MLE_MIGRATION */ {
1902 /* should only be getting an assert from new master */
1903 if (assert->node_idx != mle->new_master) {
1904 mlog(ML_ERROR, "got assert from %u, but "
1905 "new master is %u, and old master "
1906 "was %u (%.*s)\n",
1907 assert->node_idx, mle->new_master,
1908 mle->master, namelen, name);
1909 goto kill;
1910 }
1911
1912 }
1913ok:
1914 spin_unlock(&res->spinlock);
1915 }
6714d8e8
KH		 1916
1917 // mlog(0, "woo! got an assert_master from node %u!\n",
1918 // assert->node_idx);
1919 if (mle) {
9c6510a5
KH		 1920 int extra_ref = 0;
1921 int nn = -1;
a2bf0477 1922 int rr, err = 0;
2bd63216 1923
6714d8e8 1924 spin_lock(&mle->spinlock);
9c6510a5
KH		 1925 if (mle->type == DLM_MLE_BLOCK || mle->type == DLM_MLE_MIGRATION)
1926 extra_ref = 1;
1927 else {
1928 /* MASTER mle: if any bits set in the response map
1929 * then the calling node needs to re-assert to clear
1930 * up nodes that this node contacted */
2bd63216 1931 while ((nn = find_next_bit (mle->response_map, O2NM_MAX_NODES,
9c6510a5 1932 nn+1)) < O2NM_MAX_NODES) {
728b9805 1933 if (nn != dlm->node_num && nn != assert->node_idx) {
9c6510a5 1934 master_request = 1;
728b9805
JB		 1935 break;
1936 }
9c6510a5
KH		 1937 }
1938 }
6714d8e8
KH		 1939 mle->master = assert->node_idx;
1940 atomic_set(&mle->woken, 1);
1941 wake_up(&mle->wq);
1942 spin_unlock(&mle->spinlock);
1943
a2bf0477 1944 if (res) {
a6fa3640 1945 int wake = 0;
6714d8e8 1946 spin_lock(&res->spinlock);
a2bf0477
KH		 1947 if (mle->type == DLM_MLE_MIGRATION) {
1948 mlog(0, "finishing off migration of lockres %.*s, "
1949 "from %u to %u\n",
1950 res->lockname.len, res->lockname.name,
1951 dlm->node_num, mle->new_master);
1952 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 1953 wake = 1;
a2bf0477
KH		 1954 dlm_change_lockres_owner(dlm, res, mle->new_master);
1955 BUG_ON(res->state & DLM_LOCK_RES_DIRTY);
1956 } else {
1957 dlm_change_lockres_owner(dlm, res, mle->master);
1958 }
6714d8e8 1959 spin_unlock(&res->spinlock);
ba2bf218 1960 have_lockres_ref = 1;
a6fa3640
KH		 1961 if (wake)
1962 wake_up(&res->wq);
6714d8e8 1963 }
a2bf0477
KH		 1964
1965 /* master is known, detach if not already detached.
1966 * ensures that only one assert_master call will happen
1967 * on this mle. */
a2bf0477
KH		 1968 spin_lock(&dlm->master_lock);
1969
2c935bc5 1970 rr = kref_read(&mle->mle_refs);
a2bf0477
KH		 1971 if (mle->inuse > 0) {
1972 if (extra_ref && rr < 3)
1973 err = 1;
1974 else if (!extra_ref && rr < 2)
1975 err = 1;
1976 } else {
1977 if (extra_ref && rr < 2)
1978 err = 1;
1979 else if (!extra_ref && rr < 1)
1980 err = 1;
1981 }
1982 if (err) {
1983 mlog(ML_ERROR, "%s:%.*s: got assert master from %u "
1984 "that will mess up this node, refs=%d, extra=%d, "
1985 "inuse=%d\n", dlm->name, namelen, name,
1986 assert->node_idx, rr, extra_ref, mle->inuse);
1987 dlm_print_one_mle(mle);
1988 }
1c084577 1989 __dlm_unlink_mle(dlm, mle);
a2bf0477
KH		 1990 __dlm_mle_detach_hb_events(dlm, mle);
1991 __dlm_put_mle(mle);
6714d8e8
KH		 1992 if (extra_ref) {
1993 /* the assert master message now balances the extra
1994 * ref given by the master / migration request message.
1995 * if this is the last put, it will be removed
1996 * from the list. */
a2bf0477
KH		 1997 __dlm_put_mle(mle);
1998 }
1999 spin_unlock(&dlm->master_lock);
a2bf0477
KH		 2000 } else if (res) {
2001 if (res->owner != assert->node_idx) {
2002 mlog(0, "assert_master from %u, but current "
2003 "owner is %u (%.*s), no mle\n", assert->node_idx,
2004 res->owner, namelen, name);
6714d8e8
KH		 2005 }
2006 }
14741472 2007 spin_unlock(&dlm->spinlock);
6714d8e8
KH		 2008
2009done:
9c6510a5 2010 ret = 0;
3b8118cf
KH		 2011 if (res) {
2012 spin_lock(&res->spinlock);
2013 res->state |= DLM_LOCK_RES_SETREF_INPROG;
2014 spin_unlock(&res->spinlock);
2015 *ret_data = (void *)res;
2016 }
6714d8e8 2017 dlm_put(dlm);
9c6510a5
KH		 2018 if (master_request) {
2019 mlog(0, "need to tell master to reassert\n");
ba2bf218
KH		 2020 /* positive. negative would shoot down the node. */
2021 ret |= DLM_ASSERT_RESPONSE_REASSERT;
2022 if (!have_lockres_ref) {
2023 mlog(ML_ERROR, "strange, got assert from %u, MASTER "
2024 "mle present here for %s:%.*s, but no lockres!\n",
2025 assert->node_idx, dlm->name, namelen, name);
2026 }
2027 }
2028 if (have_lockres_ref) {
2029 /* let the master know we have a reference to the lockres */
2030 ret |= DLM_ASSERT_RESPONSE_MASTERY_REF;
2031 mlog(0, "%s:%.*s: got assert from %u, need a ref\n",
2032 dlm->name, namelen, name, assert->node_idx);
9c6510a5
KH		 2033 }
2034 return ret;
6714d8e8
KH		 2035
2036kill:
2037 /* kill the caller! */
a9ee4c8a
KH		 2038 mlog(ML_ERROR, "Bad message received from another node. Dumping state "
2039 "and killing the other node now! This node is OK and can continue.\n");
2040 __dlm_print_one_lock_resource(res);
6714d8e8 2041 spin_unlock(&res->spinlock);
55dacd22 2042 spin_lock(&dlm->master_lock);
2043 if (mle)
2044 __dlm_put_mle(mle);
2045 spin_unlock(&dlm->master_lock);
6714d8e8 2046 spin_unlock(&dlm->spinlock);
2bd63216 2047 *ret_data = (void *)res;
6714d8e8
KH		 2048 dlm_put(dlm);
2049 return -EINVAL;
2050}
2051
3b8118cf
KH		 2052void dlm_assert_master_post_handler(int status, void *data, void *ret_data)
2053{
2054 struct dlm_lock_resource *res = (struct dlm_lock_resource *)ret_data;
2055
2056 if (ret_data) {
2057 spin_lock(&res->spinlock);
2058 res->state &= ~DLM_LOCK_RES_SETREF_INPROG;
2059 spin_unlock(&res->spinlock);
2060 wake_up(&res->wq);
2061 dlm_lockres_put(res);
2062 }
2063 return;
2064}
2065
6714d8e8
KH		 2066int dlm_dispatch_assert_master(struct dlm_ctxt *dlm,
2067 struct dlm_lock_resource *res,
2068 int ignore_higher, u8 request_from, u32 flags)
2069{
2070 struct dlm_work_item *item;
b24ae0b5 2071 item = kzalloc(sizeof(*item), GFP_ATOMIC);
6714d8e8
KH		 2072 if (!item)
2073 return -ENOMEM;
2074
2075
2076 /* queue up work for dlm_assert_master_worker */
6714d8e8
KH		 2077 dlm_init_work_item(dlm, item, dlm_assert_master_worker, NULL);
2078 item->u.am.lockres = res; /* already have a ref */
2079 /* can optionally ignore node numbers higher than this node */
2080 item->u.am.ignore_higher = ignore_higher;
2081 item->u.am.request_from = request_from;
2082 item->u.am.flags = flags;
2083
2bd63216
SM		 2084 if (ignore_higher)
2085 mlog(0, "IGNORE HIGHER: %.*s\n", res->lockname.len,
9c6510a5 2086 res->lockname.name);
2bd63216 2087
6714d8e8
KH		 2088 spin_lock(&dlm->work_lock);
2089 list_add_tail(&item->list, &dlm->work_list);
2090 spin_unlock(&dlm->work_lock);
2091
3156d267 2092 queue_work(dlm->dlm_worker, &dlm->dispatched_work);
6714d8e8
KH		 2093 return 0;
2094}
2095
2096static void dlm_assert_master_worker(struct dlm_work_item *item, void *data)
2097{
2098 struct dlm_ctxt *dlm = data;
2099 int ret = 0;
2100 struct dlm_lock_resource *res;
2101 unsigned long nodemap[BITS_TO_LONGS(O2NM_MAX_NODES)];
2102 int ignore_higher;
2103 int bit;
2104 u8 request_from;
2105 u32 flags;
2106
2107 dlm = item->dlm;
2108 res = item->u.am.lockres;
2109 ignore_higher = item->u.am.ignore_higher;
2110 request_from = item->u.am.request_from;
2111 flags = item->u.am.flags;
2112
2113 spin_lock(&dlm->spinlock);
2114 memcpy(nodemap, dlm->domain_map, sizeof(nodemap));
2115 spin_unlock(&dlm->spinlock);
2116
2117 clear_bit(dlm->node_num, nodemap);
2118 if (ignore_higher) {
2119 /* if is this just to clear up mles for nodes below
2120 * this node, do not send the message to the original
2121 * caller or any node number higher than this */
2122 clear_bit(request_from, nodemap);
2123 bit = dlm->node_num;
2124 while (1) {
2125 bit = find_next_bit(nodemap, O2NM_MAX_NODES,
2126 bit+1);
2127 if (bit >= O2NM_MAX_NODES)
2128 break;
2129 clear_bit(bit, nodemap);
2130 }
2131 }
2132
36407488
KH		 2133 /*
2134 * If we're migrating this lock to someone else, we are no
2135 * longer allowed to assert out own mastery. OTOH, we need to
2136 * prevent migration from starting while we're still asserting
2137 * our dominance. The reserved ast delays migration.
2138 */
2139 spin_lock(&res->spinlock);
2140 if (res->state & DLM_LOCK_RES_MIGRATING) {
2141 mlog(0, "Someone asked us to assert mastery, but we're "
2142 "in the middle of migration. Skipping assert, "
2143 "the new master will handle that.\n");
2144 spin_unlock(&res->spinlock);
2145 goto put;
2146 } else
2147 __dlm_lockres_reserve_ast(res);
2148 spin_unlock(&res->spinlock);
2149
6714d8e8
KH		 2150 /* this call now finishes out the nodemap
2151 * even if one or more nodes die */
2152 mlog(0, "worker about to master %.*s here, this=%u\n",
2153 res->lockname.len, res->lockname.name, dlm->node_num);
ba2bf218 2154 ret = dlm_do_assert_master(dlm, res, nodemap, flags);
6714d8e8
KH		 2155 if (ret < 0) {
2156 /* no need to restart, we are done */
3b3b84a8
KH		 2157 if (!dlm_is_host_down(ret))
2158 mlog_errno(ret);
6714d8e8
KH		 2159 }
2160
36407488
KH		 2161 /* Ok, we've asserted ourselves. Let's let migration start. */
2162 dlm_lockres_release_ast(dlm, res);
2163
2164put:
ac4fef4d
X		 2165 dlm_lockres_drop_inflight_worker(dlm, res);
2166
6714d8e8
KH		 2167 dlm_lockres_put(res);
2168
2169 mlog(0, "finished with dlm_assert_master_worker\n");
2170}
2171
c03872f5
KH		 2172/* SPECIAL CASE for the $RECOVERY lock used by the recovery thread.
2173 * We cannot wait for node recovery to complete to begin mastering this
2174 * lockres because this lockres is used to kick off recovery! ;-)
2175 * So, do a pre-check on all living nodes to see if any of those nodes
2176 * think that $RECOVERY is currently mastered by a dead node. If so,
2177 * we wait a short time to allow that node to get notified by its own
2178 * heartbeat stack, then check again. All $RECOVERY lock resources
2bd63216 2179 * mastered by dead nodes are purged when the hearbeat callback is
c03872f5
KH		 2180 * fired, so we can know for sure that it is safe to continue once
2181 * the node returns a live node or no node. */
2182static int dlm_pre_master_reco_lockres(struct dlm_ctxt *dlm,
2183 struct dlm_lock_resource *res)
2184{
2185 struct dlm_node_iter iter;
2186 int nodenum;
2187 int ret = 0;
2188 u8 master = DLM_LOCK_RES_OWNER_UNKNOWN;
2189
2190 spin_lock(&dlm->spinlock);
2191 dlm_node_iter_init(dlm->domain_map, &iter);
2192 spin_unlock(&dlm->spinlock);
2193
2194 while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2195 /* do not send to self */
2196 if (nodenum == dlm->node_num)
2197 continue;
2198 ret = dlm_do_master_requery(dlm, res, nodenum, &master);
2199 if (ret < 0) {
2200 mlog_errno(ret);
2201 if (!dlm_is_host_down(ret))
2202 BUG();
2203 /* host is down, so answer for that node would be
2204 * DLM_LOCK_RES_OWNER_UNKNOWN. continue. */
f42a100b 2205 ret = 0;
c03872f5
KH		 2206 }
2207
2208 if (master != DLM_LOCK_RES_OWNER_UNKNOWN) {
2209 /* check to see if this master is in the recovery map */
2210 spin_lock(&dlm->spinlock);
2211 if (test_bit(master, dlm->recovery_map)) {
2212 mlog(ML_NOTICE, "%s: node %u has not seen "
2213 "node %u go down yet, and thinks the "
2214 "dead node is mastering the recovery "
2215 "lock. must wait.\n", dlm->name,
2216 nodenum, master);
2217 ret = -EAGAIN;
2218 }
2219 spin_unlock(&dlm->spinlock);
2bd63216 2220 mlog(0, "%s: reco lock master is %u\n", dlm->name,
c03872f5
KH		 2221 master);
2222 break;
2223 }
2224 }
2225 return ret;
2226}
2227
ba2bf218
KH		 2228/*
2229 * DLM_DEREF_LOCKRES_MSG
2230 */
2231
2232int dlm_drop_lockres_ref(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
2233{
2234 struct dlm_deref_lockres deref;
2235 int ret = 0, r;
2236 const char *lockname;
2237 unsigned int namelen;
2238
2239 lockname = res->lockname.name;
2240 namelen = res->lockname.len;
2241 BUG_ON(namelen > O2NM_MAX_NAME_LEN);
2242
ba2bf218
KH		 2243 memset(&deref, 0, sizeof(deref));
2244 deref.node_idx = dlm->node_num;
2245 deref.namelen = namelen;
2246 memcpy(deref.name, lockname, namelen);
2247
2248 ret = o2net_send_message(DLM_DEREF_LOCKRES_MSG, dlm->key,
2249 &deref, sizeof(deref), res->owner, &r);
2250 if (ret < 0)
8decab3c
SM		 2251 mlog(ML_ERROR, "%s: res %.*s, error %d send DEREF to node %u\n",
2252 dlm->name, namelen, lockname, ret, res->owner);
ba2bf218
KH		 2253 else if (r < 0) {
2254 /* BAD. other node says I did not have a ref. */
8decab3c
SM		 2255 mlog(ML_ERROR, "%s: res %.*s, DEREF to node %u got %d\n",
2256 dlm->name, namelen, lockname, res->owner, r);
ba2bf218 2257 dlm_print_one_lock_resource(res);
309e9191 2258 if (r == -ENOMEM)
2259 BUG();
2260 } else
2261 ret = r;
2262
2263 return ret;
ba2bf218
KH		 2264}
2265
d74c9803
KH		 2266int dlm_deref_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
2267 void **ret_data)
ba2bf218
KH		 2268{
2269 struct dlm_ctxt *dlm = data;
2270 struct dlm_deref_lockres *deref = (struct dlm_deref_lockres *)msg->buf;
2271 struct dlm_lock_resource *res = NULL;
2272 char *name;
2273 unsigned int namelen;
2274 int ret = -EINVAL;
2275 u8 node;
2276 unsigned int hash;
f3f85464
SM		 2277 struct dlm_work_item *item;
2278 int cleared = 0;
2279 int dispatch = 0;
ba2bf218
KH		 2280
2281 if (!dlm_grab(dlm))
2282 return 0;
2283
2284 name = deref->name;
2285 namelen = deref->namelen;
2286 node = deref->node_idx;
2287
2288 if (namelen > DLM_LOCKID_NAME_MAX) {
2289 mlog(ML_ERROR, "Invalid name length!");
2290 goto done;
2291 }
2292 if (deref->node_idx >= O2NM_MAX_NODES) {
2293 mlog(ML_ERROR, "Invalid node number: %u\n", node);
2294 goto done;
2295 }
2296
2297 hash = dlm_lockid_hash(name, namelen);
2298
2299 spin_lock(&dlm->spinlock);
2300 res = __dlm_lookup_lockres_full(dlm, name, namelen, hash);
2301 if (!res) {
2302 spin_unlock(&dlm->spinlock);
2303 mlog(ML_ERROR, "%s:%.*s: bad lockres name\n",
2304 dlm->name, namelen, name);
2305 goto done;
2306 }
2307 spin_unlock(&dlm->spinlock);
2308
2309 spin_lock(&res->spinlock);
f3f85464
SM		 2310 if (res->state & DLM_LOCK_RES_SETREF_INPROG)
2311 dispatch = 1;
2312 else {
2313 BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF);
2314 if (test_bit(node, res->refmap)) {
8d400b81 2315 dlm_lockres_clear_refmap_bit(dlm, res, node);
f3f85464
SM		 2316 cleared = 1;
2317 }
ba2bf218
KH		 2318 }
2319 spin_unlock(&res->spinlock);
2320
f3f85464
SM		 2321 if (!dispatch) {
2322 if (cleared)
2323 dlm_lockres_calc_usage(dlm, res);
2324 else {
2325 mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref "
2326 "but it is already dropped!\n", dlm->name,
2327 res->lockname.len, res->lockname.name, node);
2af37ce8 2328 dlm_print_one_lock_resource(res);
f3f85464 2329 }
842b90b6 2330 ret = DLM_DEREF_RESPONSE_DONE;
f3f85464
SM		 2331 goto done;
2332 }
2333
2334 item = kzalloc(sizeof(*item), GFP_NOFS);
2335 if (!item) {
2336 ret = -ENOMEM;
2337 mlog_errno(ret);
2338 goto done;
2339 }
2340
2341 dlm_init_work_item(dlm, item, dlm_deref_lockres_worker, NULL);
2342 item->u.dl.deref_res = res;
2343 item->u.dl.deref_node = node;
2344
2345 spin_lock(&dlm->work_lock);
2346 list_add_tail(&item->list, &dlm->work_list);
2347 spin_unlock(&dlm->work_lock);
2348
2349 queue_work(dlm->dlm_worker, &dlm->dispatched_work);
842b90b6 2350 return DLM_DEREF_RESPONSE_INPROG;
f3f85464 2351
ba2bf218
KH		 2352done:
2353 if (res)
2354 dlm_lockres_put(res);
2355 dlm_put(dlm);
f3f85464 2356
ba2bf218
KH		 2357 return ret;
2358}
2359
60d663cb 2360int dlm_deref_lockres_done_handler(struct o2net_msg *msg, u32 len, void *data,
2361 void **ret_data)
2362{
2363 struct dlm_ctxt *dlm = data;
2364 struct dlm_deref_lockres_done *deref
2365 = (struct dlm_deref_lockres_done *)msg->buf;
2366 struct dlm_lock_resource *res = NULL;
2367 char *name;
2368 unsigned int namelen;
2369 int ret = -EINVAL;
2370 u8 node;
2371 unsigned int hash;
2372
2373 if (!dlm_grab(dlm))
2374 return 0;
2375
2376 name = deref->name;
2377 namelen = deref->namelen;
2378 node = deref->node_idx;
2379
2380 if (namelen > DLM_LOCKID_NAME_MAX) {
2381 mlog(ML_ERROR, "Invalid name length!");
2382 goto done;
2383 }
2384 if (deref->node_idx >= O2NM_MAX_NODES) {
2385 mlog(ML_ERROR, "Invalid node number: %u\n", node);
2386 goto done;
2387 }
2388
2389 hash = dlm_lockid_hash(name, namelen);
2390
2391 spin_lock(&dlm->spinlock);
2392 res = __dlm_lookup_lockres_full(dlm, name, namelen, hash);
2393 if (!res) {
2394 spin_unlock(&dlm->spinlock);
2395 mlog(ML_ERROR, "%s:%.*s: bad lockres name\n",
2396 dlm->name, namelen, name);
2397 goto done;
2398 }
2399
2400 spin_lock(&res->spinlock);
86b652b9 2401 if (!(res->state & DLM_LOCK_RES_DROPPING_REF)) {
2402 spin_unlock(&res->spinlock);
2403 spin_unlock(&dlm->spinlock);
2404 mlog(ML_NOTICE, "%s:%.*s: node %u sends deref done "
2405 "but it is already derefed!\n", dlm->name,
2406 res->lockname.len, res->lockname.name, node);
86b652b9 2407 ret = 0;
2408 goto done;
2409 }
2410
ee8f7fcb 2411 __dlm_do_purge_lockres(dlm, res);
60d663cb 2412 spin_unlock(&res->spinlock);
2413 wake_up(&res->wq);
2414
60d663cb 2415 spin_unlock(&dlm->spinlock);
2416
b7341364 2417 ret = 0;
60d663cb 2418done:
ee8f7fcb 2419 if (res)
2420 dlm_lockres_put(res);
60d663cb 2421 dlm_put(dlm);
2422 return ret;
2423}
2424
2425static void dlm_drop_lockres_ref_done(struct dlm_ctxt *dlm,
2426 struct dlm_lock_resource *res, u8 node)
2427{
2428 struct dlm_deref_lockres_done deref;
2429 int ret = 0, r;
2430 const char *lockname;
2431 unsigned int namelen;
2432
2433 lockname = res->lockname.name;
2434 namelen = res->lockname.len;
2435 BUG_ON(namelen > O2NM_MAX_NAME_LEN);
2436
2437 memset(&deref, 0, sizeof(deref));
2438 deref.node_idx = dlm->node_num;
2439 deref.namelen = namelen;
2440 memcpy(deref.name, lockname, namelen);
2441
2442 ret = o2net_send_message(DLM_DEREF_LOCKRES_DONE, dlm->key,
2443 &deref, sizeof(deref), node, &r);
2444 if (ret < 0) {
2445 mlog(ML_ERROR, "%s: res %.*s, error %d send DEREF DONE "
2446 " to node %u\n", dlm->name, namelen,
2447 lockname, ret, node);
2448 } else if (r < 0) {
2449 /* ignore the error */
2450 mlog(ML_ERROR, "%s: res %.*s, DEREF to node %u got %d\n",
2451 dlm->name, namelen, lockname, node, r);
2452 dlm_print_one_lock_resource(res);
2453 }
2454}
2455
f3f85464
SM		 2456static void dlm_deref_lockres_worker(struct dlm_work_item *item, void *data)
2457{
2458 struct dlm_ctxt *dlm;
2459 struct dlm_lock_resource *res;
2460 u8 node;
2461 u8 cleared = 0;
2462
2463 dlm = item->dlm;
2464 res = item->u.dl.deref_res;
2465 node = item->u.dl.deref_node;
2466
2467 spin_lock(&res->spinlock);
2468 BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF);
b5560143 2469 __dlm_wait_on_lockres_flags(res, DLM_LOCK_RES_SETREF_INPROG);
f3f85464 2470 if (test_bit(node, res->refmap)) {
8d400b81 2471 dlm_lockres_clear_refmap_bit(dlm, res, node);
f3f85464
SM		 2472 cleared = 1;
2473 }
2474 spin_unlock(&res->spinlock);
2475
842b90b6 2476 dlm_drop_lockres_ref_done(dlm, res, node);
2477
f3f85464
SM		 2478 if (cleared) {
2479 mlog(0, "%s:%.*s node %u ref dropped in dispatch\n",
2480 dlm->name, res->lockname.len, res->lockname.name, node);
2481 dlm_lockres_calc_usage(dlm, res);
2482 } else {
2483 mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref "
2484 "but it is already dropped!\n", dlm->name,
2485 res->lockname.len, res->lockname.name, node);
2af37ce8 2486 dlm_print_one_lock_resource(res);
f3f85464
SM		 2487 }
2488
2489 dlm_lockres_put(res);
2490}
2491
9f62e960 2492/*
baa31b89 2493 * A migratable resource is one that is :
9f62e960
SM		 2494 * 1. locally mastered, and,
2495 * 2. zero local locks, and,
2496 * 3. one or more non-local locks, or, one or more references
2497 * Returns 1 if yes, 0 if not.
2f5bf1f2 2498 */
baa31b89 2499static int dlm_is_lockres_migratable(struct dlm_ctxt *dlm,
9f62e960 2500 struct dlm_lock_resource *res)
2f5bf1f2 2501{
9f62e960
SM		 2502 enum dlm_lockres_list idx;
2503 int nonlocal = 0, node_ref;
800deef3 2504 struct list_head *queue;
2f5bf1f2 2505 struct dlm_lock *lock;
9f62e960 2506 u64 cookie;
2f5bf1f2
SM		 2507
2508 assert_spin_locked(&res->spinlock);
2509
fae477b6
X		 2510 /* delay migration when the lockres is in MIGRATING state */
2511 if (res->state & DLM_LOCK_RES_MIGRATING)
2512 return 0;
2513
bba1cb17 2514 /* delay migration when the lockres is in RECOCERING state */
814ce694
JX		 2515 if (res->state & (DLM_LOCK_RES_RECOVERING|
2516 DLM_LOCK_RES_RECOVERY_WAITING))
bba1cb17
TS		 2517 return 0;
2518
9f62e960
SM		 2519 if (res->owner != dlm->node_num)
2520 return 0;
2f5bf1f2 2521
9f62e960
SM		 2522 for (idx = DLM_GRANTED_LIST; idx <= DLM_BLOCKED_LIST; idx++) {
2523 queue = dlm_list_idx_to_ptr(res, idx);
800deef3 2524 list_for_each_entry(lock, queue, list) {
9f62e960
SM		 2525 if (lock->ml.node != dlm->node_num) {
2526 nonlocal++;
2527 continue;
2f5bf1f2 2528 }
9f62e960 2529 cookie = be64_to_cpu(lock->ml.cookie);
baa31b89 2530 mlog(0, "%s: Not migratable res %.*s, lock %u:%llu on "
9f62e960
SM		 2531 "%s list\n", dlm->name, res->lockname.len,
2532 res->lockname.name,
2533 dlm_get_lock_cookie_node(cookie),
2534 dlm_get_lock_cookie_seq(cookie),
2535 dlm_list_in_text(idx));
2536 return 0;
2f5bf1f2 2537 }
2f5bf1f2
SM		 2538 }
2539
9f62e960
SM		 2540 if (!nonlocal) {
2541 node_ref = find_next_bit(res->refmap, O2NM_MAX_NODES, 0);
2542 if (node_ref >= O2NM_MAX_NODES)
2543 return 0;
2544 }
388c4bcb 2545
510c4879 2546 mlog(0, "%s: res %.*s, Migratable\n", dlm->name, res->lockname.len,
9f62e960 2547 res->lockname.name);
2f5bf1f2 2548
9f62e960 2549 return 1;
2f5bf1f2 2550}
6714d8e8
KH		 2551
2552/*
2553 * DLM_MIGRATE_LOCKRES
2554 */
2555
2556
faf0ec9f 2557static int dlm_migrate_lockres(struct dlm_ctxt *dlm,
66effd3c 2558 struct dlm_lock_resource *res, u8 target)
6714d8e8
KH		 2559{
2560 struct dlm_master_list_entry *mle = NULL;
2561 struct dlm_master_list_entry *oldmle = NULL;
2562 struct dlm_migratable_lockres *mres = NULL;
2f5bf1f2 2563 int ret = 0;
6714d8e8
KH		 2564 const char *name;
2565 unsigned int namelen;
2566 int mle_added = 0;
2f5bf1f2 2567 int wake = 0;
6714d8e8
KH		 2568
2569 if (!dlm_grab(dlm))
2570 return -EINVAL;
2571
66effd3c
SM		 2572 BUG_ON(target == O2NM_MAX_NODES);
2573
6714d8e8
KH		 2574 name = res->lockname.name;
2575 namelen = res->lockname.len;
2576
66effd3c
SM		 2577 mlog(0, "%s: Migrating %.*s to node %u\n", dlm->name, namelen, name,
2578 target);
6714d8e8 2579
66effd3c 2580 /* preallocate up front. if this fails, abort */
6714d8e8 2581 ret = -ENOMEM;
ad8100e0 2582 mres = (struct dlm_migratable_lockres *) __get_free_page(GFP_NOFS);
6714d8e8
KH		 2583 if (!mres) {
2584 mlog_errno(ret);
2585 goto leave;
2586 }
2587
3914ed0c 2588 mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
6714d8e8
KH		 2589 if (!mle) {
2590 mlog_errno(ret);
2591 goto leave;
2592 }
2593 ret = 0;
2594
6714d8e8
KH		 2595 /*
2596 * clear any existing master requests and
2597 * add the migration mle to the list
2598 */
66effd3c 2599 spin_lock(&dlm->spinlock);
6714d8e8
KH		 2600 spin_lock(&dlm->master_lock);
2601 ret = dlm_add_migration_mle(dlm, res, mle, &oldmle, name,
2602 namelen, target, dlm->node_num);
bef5502d 2603 /* get an extra reference on the mle.
2604 * otherwise the assert_master from the new
2605 * master will destroy this.
2606 */
3db409fa
CG		 2607 if (ret != -EEXIST)
2608 dlm_get_mle_inuse(mle);
2609
6714d8e8
KH		 2610 spin_unlock(&dlm->master_lock);
2611 spin_unlock(&dlm->spinlock);
2612
2613 if (ret == -EEXIST) {
2614 mlog(0, "another process is already migrating it\n");
2615 goto fail;
2616 }
2617 mle_added = 1;
2618
2619 /*
2620 * set the MIGRATING flag and flush asts
2621 * if we fail after this we need to re-dirty the lockres
2622 */
2623 if (dlm_mark_lockres_migrating(dlm, res, target) < 0) {
2624 mlog(ML_ERROR, "tried to migrate %.*s to %u, but "
2625 "the target went down.\n", res->lockname.len,
2626 res->lockname.name, target);
2627 spin_lock(&res->spinlock);
2628 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 2629 wake = 1;
6714d8e8
KH		 2630 spin_unlock(&res->spinlock);
2631 ret = -EINVAL;
2632 }
2633
2634fail:
32e49326 2635 if (ret != -EEXIST && oldmle) {
6714d8e8
KH		 2636 /* master is known, detach if not already detached */
2637 dlm_mle_detach_hb_events(dlm, oldmle);
2638 dlm_put_mle(oldmle);
2639 }
2640
2641 if (ret < 0) {
2642 if (mle_added) {
2643 dlm_mle_detach_hb_events(dlm, mle);
2644 dlm_put_mle(mle);
bef5502d 2645 dlm_put_mle_inuse(mle);
6714d8e8
KH		 2646 } else if (mle) {
2647 kmem_cache_free(dlm_mle_cache, mle);
66effd3c 2648 mle = NULL;
6714d8e8
KH		 2649 }
2650 goto leave;
2651 }
2652
2653 /*
2654 * at this point, we have a migration target, an mle
2655 * in the master list, and the MIGRATING flag set on
2656 * the lockres
2657 */
2658
1cd04dbe
KH		 2659 /* now that remote nodes are spinning on the MIGRATING flag,
2660 * ensure that all assert_master work is flushed. */
2661 flush_workqueue(dlm->dlm_worker);
6714d8e8 2662
6714d8e8
KH		 2663 /* notify new node and send all lock state */
2664 /* call send_one_lockres with migration flag.
2665 * this serves as notice to the target node that a
2666 * migration is starting. */
2667 ret = dlm_send_one_lockres(dlm, res, mres, target,
2668 DLM_MRES_MIGRATION);
2669
2670 if (ret < 0) {
2671 mlog(0, "migration to node %u failed with %d\n",
2672 target, ret);
2673 /* migration failed, detach and clean up mle */
2674 dlm_mle_detach_hb_events(dlm, mle);
2675 dlm_put_mle(mle);
a2bf0477
KH		 2676 dlm_put_mle_inuse(mle);
2677 spin_lock(&res->spinlock);
2678 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 2679 wake = 1;
a2bf0477 2680 spin_unlock(&res->spinlock);
df016c66
SM		 2681 if (dlm_is_host_down(ret))
2682 dlm_wait_for_node_death(dlm, target,
2683 DLM_NODE_DEATH_WAIT_MAX);
6714d8e8
KH		 2684 goto leave;
2685 }
2686
2687 /* at this point, the target sends a message to all nodes,
2688 * (using dlm_do_migrate_request). this node is skipped since
2689 * we had to put an mle in the list to begin the process. this
2690 * node now waits for target to do an assert master. this node
2691 * will be the last one notified, ensuring that the migration
2692 * is complete everywhere. if the target dies while this is
2693 * going on, some nodes could potentially see the target as the
2694 * master, so it is important that my recovery finds the migration
af901ca1 2695 * mle and sets the master to UNKNOWN. */
6714d8e8
KH		 2696
2697
2698 /* wait for new node to assert master */
2699 while (1) {
2700 ret = wait_event_interruptible_timeout(mle->wq,
2701 (atomic_read(&mle->woken) == 1),
2702 msecs_to_jiffies(5000));
2703
2704 if (ret >= 0) {
2705 if (atomic_read(&mle->woken) == 1 ||
2706 res->owner == target)
2707 break;
2708
1cd04dbe
KH		 2709 mlog(0, "%s:%.*s: timed out during migration\n",
2710 dlm->name, res->lockname.len, res->lockname.name);
2bd63216 2711 /* avoid hang during shutdown when migrating lockres
e2faea4c
KH		 2712 * to a node which also goes down */
2713 if (dlm_is_node_dead(dlm, target)) {
aa852354
KH		 2714 mlog(0, "%s:%.*s: expected migration "
2715 "target %u is no longer up, restarting\n",
e2faea4c
KH		 2716 dlm->name, res->lockname.len,
2717 res->lockname.name, target);
1cd04dbe
KH		 2718 ret = -EINVAL;
2719 /* migration failed, detach and clean up mle */
2720 dlm_mle_detach_hb_events(dlm, mle);
2721 dlm_put_mle(mle);
2722 dlm_put_mle_inuse(mle);
2723 spin_lock(&res->spinlock);
2724 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 2725 wake = 1;
1cd04dbe
KH		 2726 spin_unlock(&res->spinlock);
2727 goto leave;
e2faea4c 2728 }
1cd04dbe
KH		 2729 } else
2730 mlog(0, "%s:%.*s: caught signal during migration\n",
2731 dlm->name, res->lockname.len, res->lockname.name);
6714d8e8
KH		 2732 }
2733
2734 /* all done, set the owner, clear the flag */
2735 spin_lock(&res->spinlock);
2736 dlm_set_lockres_owner(dlm, res, target);
2737 res->state &= ~DLM_LOCK_RES_MIGRATING;
2738 dlm_remove_nonlocal_locks(dlm, res);
2739 spin_unlock(&res->spinlock);
2740 wake_up(&res->wq);
2741
2742 /* master is known, detach if not already detached */
2743 dlm_mle_detach_hb_events(dlm, mle);
a2bf0477 2744 dlm_put_mle_inuse(mle);
6714d8e8
KH		 2745 ret = 0;
2746
2747 dlm_lockres_calc_usage(dlm, res);
2748
2749leave:
2750 /* re-dirty the lockres if we failed */
2751 if (ret < 0)
2752 dlm_kick_thread(dlm, res);
2753
a6fa3640
KH		 2754 /* wake up waiters if the MIGRATING flag got set
2755 * but migration failed */
2756 if (wake)
2757 wake_up(&res->wq);
2758
6714d8e8
KH		 2759 if (mres)
2760 free_page((unsigned long)mres);
2761
2762 dlm_put(dlm);
2763
9f62e960
SM		 2764 mlog(0, "%s: Migrating %.*s to %u, returns %d\n", dlm->name, namelen,
2765 name, target, ret);
6714d8e8
KH		 2766 return ret;
2767}
6714d8e8 2768
ba2bf218
KH		 2769#define DLM_MIGRATION_RETRY_MS 100
2770
9f62e960
SM		 2771/*
2772 * Should be called only after beginning the domain leave process.
ba2bf218
KH		 2773 * There should not be any remaining locks on nonlocal lock resources,
2774 * and there should be no local locks left on locally mastered resources.
2775 *
2776 * Called with the dlm spinlock held, may drop it to do migration, but
2777 * will re-acquire before exit.
2778 *
9f62e960
SM		 2779 * Returns: 1 if dlm->spinlock was dropped/retaken, 0 if never dropped
2780 */
ba2bf218
KH		 2781int dlm_empty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
2782{
66effd3c 2783 int ret;
ba2bf218 2784 int lock_dropped = 0;
66effd3c 2785 u8 target = O2NM_MAX_NODES;
ba2bf218 2786
9f62e960 2787 assert_spin_locked(&dlm->spinlock);
2f5bf1f2 2788
9f62e960 2789 spin_lock(&res->spinlock);
baa31b89 2790 if (dlm_is_lockres_migratable(dlm, res))
66effd3c 2791 target = dlm_pick_migration_target(dlm, res);
b36c3f84 2792 spin_unlock(&res->spinlock);
66effd3c
SM		 2793
2794 if (target == O2NM_MAX_NODES)
9f62e960 2795 goto leave;
ba2bf218
KH		 2796
2797 /* Wheee! Migrate lockres here! Will sleep so drop spinlock. */
2798 spin_unlock(&dlm->spinlock);
2799 lock_dropped = 1;
66effd3c
SM		 2800 ret = dlm_migrate_lockres(dlm, res, target);
2801 if (ret)
2802 mlog(0, "%s: res %.*s, Migrate to node %u failed with %d\n",
2803 dlm->name, res->lockname.len, res->lockname.name,
2804 target, ret);
ba2bf218
KH		 2805 spin_lock(&dlm->spinlock);
2806leave:
2807 return lock_dropped;
2808}
2809
6714d8e8
KH		 2810int dlm_lock_basts_flushed(struct dlm_ctxt *dlm, struct dlm_lock *lock)
2811{
2812 int ret;
2813 spin_lock(&dlm->ast_lock);
2814 spin_lock(&lock->spinlock);
2815 ret = (list_empty(&lock->bast_list) && !lock->bast_pending);
2816 spin_unlock(&lock->spinlock);
2817 spin_unlock(&dlm->ast_lock);
2818 return ret;
2819}
2820
2821static int dlm_migration_can_proceed(struct dlm_ctxt *dlm,
2822 struct dlm_lock_resource *res,
2823 u8 mig_target)
2824{
2825 int can_proceed;
2826 spin_lock(&res->spinlock);
2827 can_proceed = !!(res->state & DLM_LOCK_RES_MIGRATING);
2828 spin_unlock(&res->spinlock);
2829
2bd63216 2830 /* target has died, so make the caller break out of the
6714d8e8
KH		 2831 * wait_event, but caller must recheck the domain_map */
2832 spin_lock(&dlm->spinlock);
2833 if (!test_bit(mig_target, dlm->domain_map))
2834 can_proceed = 1;
2835 spin_unlock(&dlm->spinlock);
2836 return can_proceed;
2837}
2838
faf0ec9f
AB		 2839static int dlm_lockres_is_dirty(struct dlm_ctxt *dlm,
2840 struct dlm_lock_resource *res)
6714d8e8
KH		 2841{
2842 int ret;
2843 spin_lock(&res->spinlock);
2844 ret = !!(res->state & DLM_LOCK_RES_DIRTY);
2845 spin_unlock(&res->spinlock);
2846 return ret;
2847}
2848
2849
2850static int dlm_mark_lockres_migrating(struct dlm_ctxt *dlm,
2851 struct dlm_lock_resource *res,
2852 u8 target)
2853{
2854 int ret = 0;
2855
2856 mlog(0, "dlm_mark_lockres_migrating: %.*s, from %u to %u\n",
2857 res->lockname.len, res->lockname.name, dlm->node_num,
2858 target);
2859 /* need to set MIGRATING flag on lockres. this is done by
2860 * ensuring that all asts have been flushed for this lockres. */
2861 spin_lock(&res->spinlock);
2862 BUG_ON(res->migration_pending);
2863 res->migration_pending = 1;
2864 /* strategy is to reserve an extra ast then release
2865 * it below, letting the release do all of the work */
2866 __dlm_lockres_reserve_ast(res);
2867 spin_unlock(&res->spinlock);
2868
ddc09c8d 2869 /* now flush all the pending asts */
6714d8e8 2870 dlm_kick_thread(dlm, res);
ddc09c8d
KH		 2871 /* before waiting on DIRTY, block processes which may
2872 * try to dirty the lockres before MIGRATING is set */
2873 spin_lock(&res->spinlock);
2874 BUG_ON(res->state & DLM_LOCK_RES_BLOCK_DIRTY);
2875 res->state |= DLM_LOCK_RES_BLOCK_DIRTY;
2876 spin_unlock(&res->spinlock);
2877 /* now wait on any pending asts and the DIRTY state */
6714d8e8
KH		 2878 wait_event(dlm->ast_wq, !dlm_lockres_is_dirty(dlm, res));
2879 dlm_lockres_release_ast(dlm, res);
2880
2881 mlog(0, "about to wait on migration_wq, dirty=%s\n",
2882 res->state & DLM_LOCK_RES_DIRTY ? "yes" : "no");
2883 /* if the extra ref we just put was the final one, this
2884 * will pass thru immediately. otherwise, we need to wait
2885 * for the last ast to finish. */
2886again:
2887 ret = wait_event_interruptible_timeout(dlm->migration_wq,
2888 dlm_migration_can_proceed(dlm, res, target),
2889 msecs_to_jiffies(1000));
2890 if (ret < 0) {
2891 mlog(0, "woken again: migrating? %s, dead? %s\n",
2892 res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no",
2893 test_bit(target, dlm->domain_map) ? "no":"yes");
2894 } else {
2895 mlog(0, "all is well: migrating? %s, dead? %s\n",
2896 res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no",
2897 test_bit(target, dlm->domain_map) ? "no":"yes");
2898 }
2899 if (!dlm_migration_can_proceed(dlm, res, target)) {
2900 mlog(0, "trying again...\n");
2901 goto again;
2902 }
2903
a39953dd 2904 ret = 0;
6714d8e8
KH		 2905 /* did the target go down or die? */
2906 spin_lock(&dlm->spinlock);
2907 if (!test_bit(target, dlm->domain_map)) {
2908 mlog(ML_ERROR, "aha. migration target %u just went down\n",
2909 target);
2910 ret = -EHOSTDOWN;
2911 }
2912 spin_unlock(&dlm->spinlock);
2913
a39953dd
WW		 2914 /*
2915 * if target is down, we need to clear DLM_LOCK_RES_BLOCK_DIRTY for
2916 * another try; otherwise, we are sure the MIGRATING state is there,
4d39f0ac 2917 * drop the unneeded state which blocked threads trying to DIRTY
a39953dd
WW		 2918 */
2919 spin_lock(&res->spinlock);
2920 BUG_ON(!(res->state & DLM_LOCK_RES_BLOCK_DIRTY));
2921 res->state &= ~DLM_LOCK_RES_BLOCK_DIRTY;
2922 if (!ret)
2923 BUG_ON(!(res->state & DLM_LOCK_RES_MIGRATING));
cc28d6d8 2924 else
2925 res->migration_pending = 0;
a39953dd
WW		 2926 spin_unlock(&res->spinlock);
2927
6714d8e8
KH		 2928 /*
2929 * at this point:
2930 *
a39953dd 2931 * o the DLM_LOCK_RES_MIGRATING flag is set if target not down
6714d8e8
KH		 2932 * o there are no pending asts on this lockres
2933 * o all processes trying to reserve an ast on this
2934 * lockres must wait for the MIGRATING flag to clear
2935 */
2936 return ret;
2937}
2938
2939/* last step in the migration process.
2940 * original master calls this to free all of the dlm_lock
2941 * structures that used to be for other nodes. */
2942static void dlm_remove_nonlocal_locks(struct dlm_ctxt *dlm,
2943 struct dlm_lock_resource *res)
2944{
6714d8e8 2945 struct list_head *queue = &res->granted;
ba2bf218 2946 int i, bit;
800deef3 2947 struct dlm_lock *lock, *next;
6714d8e8
KH		 2948
2949 assert_spin_locked(&res->spinlock);
2950
2951 BUG_ON(res->owner == dlm->node_num);
2952
2953 for (i=0; i<3; i++) {
800deef3 2954 list_for_each_entry_safe(lock, next, queue, list) {
6714d8e8
KH		 2955 if (lock->ml.node != dlm->node_num) {
2956 mlog(0, "putting lock for node %u\n",
2957 lock->ml.node);
2958 /* be extra careful */
2959 BUG_ON(!list_empty(&lock->ast_list));
2960 BUG_ON(!list_empty(&lock->bast_list));
2961 BUG_ON(lock->ast_pending);
2962 BUG_ON(lock->bast_pending);
8d400b81
SM		 2963 dlm_lockres_clear_refmap_bit(dlm, res,
2964 lock->ml.node);
6714d8e8
KH		 2965 list_del_init(&lock->list);
2966 dlm_lock_put(lock);
2c5c54ac
SM		 2967 /* In a normal unlock, we would have added a
2968 * DLM_UNLOCK_FREE_LOCK action. Force it. */
2969 dlm_lock_put(lock);
6714d8e8
KH		 2970 }
2971 }
2972 queue++;
2973 }
ba2bf218
KH		 2974 bit = 0;
2975 while (1) {
2976 bit = find_next_bit(res->refmap, O2NM_MAX_NODES, bit);
2977 if (bit >= O2NM_MAX_NODES)
2978 break;
2979 /* do not clear the local node reference, if there is a
2980 * process holding this, let it drop the ref itself */
2981 if (bit != dlm->node_num) {
2982 mlog(0, "%s:%.*s: node %u had a ref to this "
2983 "migrating lockres, clearing\n", dlm->name,
2984 res->lockname.len, res->lockname.name, bit);
8d400b81 2985 dlm_lockres_clear_refmap_bit(dlm, res, bit);
ba2bf218
KH		 2986 }
2987 bit++;
2988 }
6714d8e8
KH		 2989}
2990
66effd3c
SM		 2991/*
2992 * Pick a node to migrate the lock resource to. This function selects a
2993 * potential target based first on the locks and then on refmap. It skips
2994 * nodes that are in the process of exiting the domain.
2995 */
6714d8e8
KH		 2996static u8 dlm_pick_migration_target(struct dlm_ctxt *dlm,
2997 struct dlm_lock_resource *res)
2998{
66effd3c 2999 enum dlm_lockres_list idx;
6714d8e8 3000 struct list_head *queue = &res->granted;
6714d8e8 3001 struct dlm_lock *lock;
66effd3c
SM		 3002 int noderef;
3003 u8 nodenum = O2NM_MAX_NODES;
6714d8e8
KH		 3004
3005 assert_spin_locked(&dlm->spinlock);
66effd3c 3006 assert_spin_locked(&res->spinlock);
6714d8e8 3007
66effd3c
SM		 3008 /* Go through all the locks */
3009 for (idx = DLM_GRANTED_LIST; idx <= DLM_BLOCKED_LIST; idx++) {
3010 queue = dlm_list_idx_to_ptr(res, idx);
800deef3 3011 list_for_each_entry(lock, queue, list) {
66effd3c
SM		 3012 if (lock->ml.node == dlm->node_num)
3013 continue;
3014 if (test_bit(lock->ml.node, dlm->exit_domain_map))
3015 continue;
3016 nodenum = lock->ml.node;
3017 goto bail;
6714d8e8 3018 }
6714d8e8 3019 }
388c4bcb 3020
66effd3c
SM		 3021 /* Go thru the refmap */
3022 noderef = -1;
6714d8e8 3023 while (1) {
66effd3c
SM		 3024 noderef = find_next_bit(res->refmap, O2NM_MAX_NODES,
3025 noderef + 1);
3026 if (noderef >= O2NM_MAX_NODES)
6714d8e8 3027 break;
66effd3c
SM		 3028 if (noderef == dlm->node_num)
3029 continue;
3030 if (test_bit(noderef, dlm->exit_domain_map))
3031 continue;
3032 nodenum = noderef;
3033 goto bail;
6714d8e8
KH		 3034 }
3035
66effd3c
SM		 3036bail:
3037 return nodenum;
6714d8e8
KH		 3038}
3039
6714d8e8
KH		 3040/* this is called by the new master once all lockres
3041 * data has been received */
3042static int dlm_do_migrate_request(struct dlm_ctxt *dlm,
3043 struct dlm_lock_resource *res,
3044 u8 master, u8 new_master,
3045 struct dlm_node_iter *iter)
3046{
3047 struct dlm_migrate_request migrate;
2b832564 3048 int ret, skip, status = 0;
6714d8e8
KH		 3049 int nodenum;
3050
3051 memset(&migrate, 0, sizeof(migrate));
3052 migrate.namelen = res->lockname.len;
3053 memcpy(migrate.name, res->lockname.name, migrate.namelen);
3054 migrate.new_master = new_master;
3055 migrate.master = master;
3056
3057 ret = 0;
3058
3059 /* send message to all nodes, except the master and myself */
3060 while ((nodenum = dlm_node_iter_next(iter)) >= 0) {
3061 if (nodenum == master ||
3062 nodenum == new_master)
3063 continue;
3064
2b832564
SM		 3065 /* We could race exit domain. If exited, skip. */
3066 spin_lock(&dlm->spinlock);
3067 skip = (!test_bit(nodenum, dlm->domain_map));
3068 spin_unlock(&dlm->spinlock);
3069 if (skip) {
3070 clear_bit(nodenum, iter->node_map);
3071 continue;
3072 }
3073
6714d8e8
KH		 3074 ret = o2net_send_message(DLM_MIGRATE_REQUEST_MSG, dlm->key,
3075 &migrate, sizeof(migrate), nodenum,
3076 &status);
2b832564 3077 if (ret < 0) {
8decab3c
SM		 3078 mlog(ML_ERROR, "%s: res %.*s, Error %d send "
3079 "MIGRATE_REQUEST to node %u\n", dlm->name,
3080 migrate.namelen, migrate.name, ret, nodenum);
2b832564
SM		 3081 if (!dlm_is_host_down(ret)) {
3082 mlog(ML_ERROR, "unhandled error=%d!\n", ret);
3083 BUG();
3084 }
3085 clear_bit(nodenum, iter->node_map);
3086 ret = 0;
3087 } else if (status < 0) {
6714d8e8
KH		 3088 mlog(0, "migrate request (node %u) returned %d!\n",
3089 nodenum, status);
3090 ret = status;
ba2bf218
KH		 3091 } else if (status == DLM_MIGRATE_RESPONSE_MASTERY_REF) {
3092 /* during the migration request we short-circuited
3093 * the mastery of the lockres. make sure we have
3094 * a mastery ref for nodenum */
3095 mlog(0, "%s:%.*s: need ref for node %u\n",
3096 dlm->name, res->lockname.len, res->lockname.name,
3097 nodenum);
3098 spin_lock(&res->spinlock);
8d400b81 3099 dlm_lockres_set_refmap_bit(dlm, res, nodenum);
ba2bf218 3100 spin_unlock(&res->spinlock);
6714d8e8
KH		 3101 }
3102 }
3103
3104 if (ret < 0)
3105 mlog_errno(ret);
3106
3107 mlog(0, "returning ret=%d\n", ret);
3108 return ret;
3109}
3110
3111
3112/* if there is an existing mle for this lockres, we now know who the master is.
3113 * (the one who sent us *this* message) we can clear it up right away.
3114 * since the process that put the mle on the list still has a reference to it,
3115 * we can unhash it now, set the master and wake the process. as a result,
3116 * we will have no mle in the list to start with. now we can add an mle for
3117 * the migration and this should be the only one found for those scanning the
3118 * list. */
d74c9803
KH		 3119int dlm_migrate_request_handler(struct o2net_msg *msg, u32 len, void *data,
3120 void **ret_data)
6714d8e8
KH		 3121{
3122 struct dlm_ctxt *dlm = data;
3123 struct dlm_lock_resource *res = NULL;
3124 struct dlm_migrate_request *migrate = (struct dlm_migrate_request *) msg->buf;
3125 struct dlm_master_list_entry *mle = NULL, *oldmle = NULL;
3126 const char *name;
a3d33291 3127 unsigned int namelen, hash;
6714d8e8
KH		 3128 int ret = 0;
3129
3130 if (!dlm_grab(dlm))
c372f219 3131 return 0;
6714d8e8
KH		 3132
3133 name = migrate->name;
3134 namelen = migrate->namelen;
a3d33291 3135 hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 3136
3137 /* preallocate.. if this fails, abort */
3914ed0c 3138 mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
6714d8e8
KH		 3139
3140 if (!mle) {
3141 ret = -ENOMEM;
3142 goto leave;
3143 }
3144
3145 /* check for pre-existing lock */
3146 spin_lock(&dlm->spinlock);
a3d33291 3147 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
6714d8e8
KH		 3148 if (res) {
3149 spin_lock(&res->spinlock);
3150 if (res->state & DLM_LOCK_RES_RECOVERING) {
3151 /* if all is working ok, this can only mean that we got
3152 * a migrate request from a node that we now see as
3153 * dead. what can we do here? drop it to the floor? */
3154 spin_unlock(&res->spinlock);
3155 mlog(ML_ERROR, "Got a migrate request, but the "
3156 "lockres is marked as recovering!");
3157 kmem_cache_free(dlm_mle_cache, mle);
3158 ret = -EINVAL; /* need a better solution */
3159 goto unlock;
3160 }
3161 res->state |= DLM_LOCK_RES_MIGRATING;
3162 spin_unlock(&res->spinlock);
3163 }
3164
6d98c3cc 3165 spin_lock(&dlm->master_lock);
6714d8e8
KH		 3166 /* ignore status. only nonzero status would BUG. */
3167 ret = dlm_add_migration_mle(dlm, res, mle, &oldmle,
3168 name, namelen,
3169 migrate->new_master,
3170 migrate->master);
3171
0cc482ee
G		 3172 if (ret < 0)
3173 kmem_cache_free(dlm_mle_cache, mle);
3174
6714d8e8 3175 spin_unlock(&dlm->master_lock);
6d98c3cc 3176unlock:
6714d8e8
KH		 3177 spin_unlock(&dlm->spinlock);
3178
3179 if (oldmle) {
3180 /* master is known, detach if not already detached */
3181 dlm_mle_detach_hb_events(dlm, oldmle);
3182 dlm_put_mle(oldmle);
3183 }
3184
3185 if (res)
3186 dlm_lockres_put(res);
3187leave:
3188 dlm_put(dlm);
3189 return ret;
3190}
3191
3192/* must be holding dlm->spinlock and dlm->master_lock
3193 * when adding a migration mle, we can clear any other mles
3194 * in the master list because we know with certainty that
3195 * the master is "master". so we remove any old mle from
3196 * the list after setting it's master field, and then add
3197 * the new migration mle. this way we can hold with the rule
3198 * of having only one mle for a given lock name at all times. */
3199static int dlm_add_migration_mle(struct dlm_ctxt *dlm,
3200 struct dlm_lock_resource *res,
3201 struct dlm_master_list_entry *mle,
3202 struct dlm_master_list_entry **oldmle,
3203 const char *name, unsigned int namelen,
3204 u8 new_master, u8 master)
3205{
3206 int found;
3207 int ret = 0;
3208
3209 *oldmle = NULL;
3210
6714d8e8
KH		 3211 assert_spin_locked(&dlm->spinlock);
3212 assert_spin_locked(&dlm->master_lock);
3213
3214 /* caller is responsible for any ref taken here on oldmle */
3215 found = dlm_find_mle(dlm, oldmle, (char *)name, namelen);
3216 if (found) {
3217 struct dlm_master_list_entry *tmp = *oldmle;
3218 spin_lock(&tmp->spinlock);
3219 if (tmp->type == DLM_MLE_MIGRATION) {
3220 if (master == dlm->node_num) {
3221 /* ah another process raced me to it */
3222 mlog(0, "tried to migrate %.*s, but some "
3223 "process beat me to it\n",
3224 namelen, name);
32e49326 3225 spin_unlock(&tmp->spinlock);
3226 return -EEXIST;
6714d8e8
KH		 3227 } else {
3228 /* bad. 2 NODES are trying to migrate! */
3229 mlog(ML_ERROR, "migration error mle: "
3230 "master=%u new_master=%u // request: "
3231 "master=%u new_master=%u // "
3232 "lockres=%.*s\n",
3233 tmp->master, tmp->new_master,
3234 master, new_master,
3235 namelen, name);
3236 BUG();
3237 }
3238 } else {
3239 /* this is essentially what assert_master does */
3240 tmp->master = master;
3241 atomic_set(&tmp->woken, 1);
3242 wake_up(&tmp->wq);
1c084577
SM		 3243 /* remove it so that only one mle will be found */
3244 __dlm_unlink_mle(dlm, tmp);
ba2bf218 3245 __dlm_mle_detach_hb_events(dlm, tmp);
b9aaac5a 3246 if (tmp->type == DLM_MLE_MASTER) {
3247 ret = DLM_MIGRATE_RESPONSE_MASTERY_REF;
3248 mlog(0, "%s:%.*s: master=%u, newmaster=%u, "
3249 "telling master to get ref "
3250 "for cleared out mle during "
3251 "migration\n", dlm->name,
3252 namelen, name, master,
3253 new_master);
3254 }
6714d8e8
KH		 3255 }
3256 spin_unlock(&tmp->spinlock);
3257 }
3258
3259 /* now add a migration mle to the tail of the list */
3260 dlm_init_mle(mle, DLM_MLE_MIGRATION, dlm, res, name, namelen);
3261 mle->new_master = new_master;
ba2bf218
KH		 3262 /* the new master will be sending an assert master for this.
3263 * at that point we will get the refmap reference */
6714d8e8
KH		 3264 mle->master = master;
3265 /* do this for consistency with other mle types */
3266 set_bit(new_master, mle->maybe_map);
1c084577 3267 __dlm_insert_mle(dlm, mle);
6714d8e8
KH		 3268
3269 return ret;
3270}
3271
c2cd4a44
SM		 3272/*
3273 * Sets the owner of the lockres, associated to the mle, to UNKNOWN
3274 */
3275static struct dlm_lock_resource *dlm_reset_mleres_owner(struct dlm_ctxt *dlm,
3276 struct dlm_master_list_entry *mle)
3277{
3278 struct dlm_lock_resource *res;
c2cd4a44
SM		 3279
3280 /* Find the lockres associated to the mle and set its owner to UNK */
7141514b
SM		 3281 res = __dlm_lookup_lockres(dlm, mle->mname, mle->mnamelen,
3282 mle->mnamehash);
c2cd4a44
SM		 3283 if (res) {
3284 spin_unlock(&dlm->master_lock);
3285
3286 /* move lockres onto recovery list */
3287 spin_lock(&res->spinlock);
3288 dlm_set_lockres_owner(dlm, res, DLM_LOCK_RES_OWNER_UNKNOWN);
3289 dlm_move_lockres_to_recovery_list(dlm, res);
3290 spin_unlock(&res->spinlock);
3291 dlm_lockres_put(res);
3292
3293 /* about to get rid of mle, detach from heartbeat */
3294 __dlm_mle_detach_hb_events(dlm, mle);
3295
3296 /* dump the mle */
3297 spin_lock(&dlm->master_lock);
3298 __dlm_put_mle(mle);
3299 spin_unlock(&dlm->master_lock);
3300 }
3301
3302 return res;
3303}
3304
3305static void dlm_clean_migration_mle(struct dlm_ctxt *dlm,
3306 struct dlm_master_list_entry *mle)
3307{
3308 __dlm_mle_detach_hb_events(dlm, mle);
3309
3310 spin_lock(&mle->spinlock);
3311 __dlm_unlink_mle(dlm, mle);
3312 atomic_set(&mle->woken, 1);
3313 spin_unlock(&mle->spinlock);
3314
3315 wake_up(&mle->wq);
3316}
3317
3318static void dlm_clean_block_mle(struct dlm_ctxt *dlm,
3319 struct dlm_master_list_entry *mle, u8 dead_node)
3320{
3321 int bit;
3322
3323 BUG_ON(mle->type != DLM_MLE_BLOCK);
3324
3325 spin_lock(&mle->spinlock);
3326 bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0);
3327 if (bit != dead_node) {
3328 mlog(0, "mle found, but dead node %u would not have been "
3329 "master\n", dead_node);
3330 spin_unlock(&mle->spinlock);
3331 } else {
3332 /* Must drop the refcount by one since the assert_master will
3333 * never arrive. This may result in the mle being unlinked and
3334 * freed, but there may still be a process waiting in the
3335 * dlmlock path which is fine. */
3336 mlog(0, "node %u was expected master\n", dead_node);
3337 atomic_set(&mle->woken, 1);
3338 spin_unlock(&mle->spinlock);
3339 wake_up(&mle->wq);
3340
3341 /* Do not need events any longer, so detach from heartbeat */
3342 __dlm_mle_detach_hb_events(dlm, mle);
3343 __dlm_put_mle(mle);
3344 }
3345}
6714d8e8
KH		 3346
3347void dlm_clean_master_list(struct dlm_ctxt *dlm, u8 dead_node)
3348{
2ed6c750 3349 struct dlm_master_list_entry *mle;
6714d8e8 3350 struct dlm_lock_resource *res;
2ed6c750 3351 struct hlist_head *bucket;
df53cd3b 3352 struct hlist_node *tmp;
2ed6c750 3353 unsigned int i;
6714d8e8 3354
ef6b689b 3355 mlog(0, "dlm=%s, dead node=%u\n", dlm->name, dead_node);
6714d8e8
KH		 3356top:
3357 assert_spin_locked(&dlm->spinlock);
3358
3359 /* clean the master list */
3360 spin_lock(&dlm->master_lock);
2ed6c750
SM		 3361 for (i = 0; i < DLM_HASH_BUCKETS; i++) {
3362 bucket = dlm_master_hash(dlm, i);
df53cd3b 3363 hlist_for_each_entry_safe(mle, tmp, bucket, master_hash_node) {
67ae1f06
SM		 3364 BUG_ON(mle->type != DLM_MLE_BLOCK &&
3365 mle->type != DLM_MLE_MASTER &&
3366 mle->type != DLM_MLE_MIGRATION);
3367
3368 /* MASTER mles are initiated locally. The waiting
3369 * process will notice the node map change shortly.
3370 * Let that happen as normal. */
3371 if (mle->type == DLM_MLE_MASTER)
3372 continue;
3373
3374 /* BLOCK mles are initiated by other nodes. Need to
3375 * clean up if the dead node would have been the
3376 * master. */
3377 if (mle->type == DLM_MLE_BLOCK) {
3378 dlm_clean_block_mle(dlm, mle, dead_node);
3379 continue;
3380 }
6714d8e8 3381
67ae1f06
SM		 3382 /* Everything else is a MIGRATION mle */
3383
3384 /* The rule for MIGRATION mles is that the master
3385 * becomes UNKNOWN if *either* the original or the new
3386 * master dies. All UNKNOWN lockres' are sent to
3387 * whichever node becomes the recovery master. The new
3388 * master is responsible for determining if there is
3389 * still a master for this lockres, or if he needs to
3390 * take over mastery. Either way, this node should
3391 * expect another message to resolve this. */
3392
3393 if (mle->master != dead_node &&
3394 mle->new_master != dead_node)
3395 continue;
3396
bef5502d 3397 if (mle->new_master == dead_node && mle->inuse) {
3398 mlog(ML_NOTICE, "%s: target %u died during "
3399 "migration from %u, the MLE is "
3400 "still keep used, ignore it!\n",
3401 dlm->name, dead_node,
3402 mle->master);
3403 continue;
3404 }
3405
67ae1f06
SM		 3406 /* If we have reached this point, this mle needs to be
3407 * removed from the list and freed. */
3408 dlm_clean_migration_mle(dlm, mle);
3409
3410 mlog(0, "%s: node %u died during migration from "
3411 "%u to %u!\n", dlm->name, dead_node, mle->master,
3412 mle->new_master);
3413
3414 /* If we find a lockres associated with the mle, we've
3415 * hit this rare case that messes up our lock ordering.
3416 * If so, we need to drop the master lock so that we can
3417 * take the lockres lock, meaning that we will have to
3418 * restart from the head of list. */
3419 res = dlm_reset_mleres_owner(dlm, mle);
3420 if (res)
3421 /* restart */
3422 goto top;
3423
3424 /* This may be the last reference */
3425 __dlm_put_mle(mle);
6714d8e8 3426 }
2ed6c750 3427 }
6714d8e8
KH		 3428 spin_unlock(&dlm->master_lock);
3429}
3430
6714d8e8
KH		 3431int dlm_finish_migration(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
3432 u8 old_master)
3433{
3434 struct dlm_node_iter iter;
3435 int ret = 0;
3436
3437 spin_lock(&dlm->spinlock);
3438 dlm_node_iter_init(dlm->domain_map, &iter);
3439 clear_bit(old_master, iter.node_map);
3440 clear_bit(dlm->node_num, iter.node_map);
3441 spin_unlock(&dlm->spinlock);
3442
ba2bf218
KH		 3443 /* ownership of the lockres is changing. account for the
3444 * mastery reference here since old_master will briefly have
3445 * a reference after the migration completes */
3446 spin_lock(&res->spinlock);
8d400b81 3447 dlm_lockres_set_refmap_bit(dlm, res, old_master);
ba2bf218
KH		 3448 spin_unlock(&res->spinlock);
3449
6714d8e8
KH		 3450 mlog(0, "now time to do a migrate request to other nodes\n");
3451 ret = dlm_do_migrate_request(dlm, res, old_master,
3452 dlm->node_num, &iter);
3453 if (ret < 0) {
3454 mlog_errno(ret);
3455 goto leave;
3456 }
3457
3458 mlog(0, "doing assert master of %.*s to all except the original node\n",
3459 res->lockname.len, res->lockname.name);
3460 /* this call now finishes out the nodemap
3461 * even if one or more nodes die */
ba2bf218 3462 ret = dlm_do_assert_master(dlm, res, iter.node_map,
6714d8e8
KH		 3463 DLM_ASSERT_MASTER_FINISH_MIGRATION);
3464 if (ret < 0) {
3465 /* no longer need to retry. all living nodes contacted. */
3466 mlog_errno(ret);
3467 ret = 0;
3468 }
3469
3470 memset(iter.node_map, 0, sizeof(iter.node_map));
3471 set_bit(old_master, iter.node_map);
3472 mlog(0, "doing assert master of %.*s back to %u\n",
3473 res->lockname.len, res->lockname.name, old_master);
ba2bf218 3474 ret = dlm_do_assert_master(dlm, res, iter.node_map,
6714d8e8
KH		 3475 DLM_ASSERT_MASTER_FINISH_MIGRATION);
3476 if (ret < 0) {
3477 mlog(0, "assert master to original master failed "
3478 "with %d.\n", ret);
3479 /* the only nonzero status here would be because of
3480 * a dead original node. we're done. */
3481 ret = 0;
3482 }
3483
3484 /* all done, set the owner, clear the flag */
3485 spin_lock(&res->spinlock);
3486 dlm_set_lockres_owner(dlm, res, dlm->node_num);
3487 res->state &= ~DLM_LOCK_RES_MIGRATING;
3488 spin_unlock(&res->spinlock);
3489 /* re-dirty it on the new master */
3490 dlm_kick_thread(dlm, res);
3491 wake_up(&res->wq);
3492leave:
3493 return ret;
3494}
3495
3496/*
3497 * LOCKRES AST REFCOUNT
3498 * this is integral to migration
3499 */
3500
3501/* for future intent to call an ast, reserve one ahead of time.
3502 * this should be called only after waiting on the lockres
3503 * with dlm_wait_on_lockres, and while still holding the
3504 * spinlock after the call. */
3505void __dlm_lockres_reserve_ast(struct dlm_lock_resource *res)
3506{
3507 assert_spin_locked(&res->spinlock);
3508 if (res->state & DLM_LOCK_RES_MIGRATING) {
3509 __dlm_print_one_lock_resource(res);
3510 }
3511 BUG_ON(res->state & DLM_LOCK_RES_MIGRATING);
3512
3513 atomic_inc(&res->asts_reserved);
3514}
3515
3516/*
3517 * used to drop the reserved ast, either because it went unused,
3518 * or because the ast/bast was actually called.
3519 *
3520 * also, if there is a pending migration on this lockres,
3521 * and this was the last pending ast on the lockres,
3522 * atomically set the MIGRATING flag before we drop the lock.
3523 * this is how we ensure that migration can proceed with no
3524 * asts in progress. note that it is ok if the state of the
3525 * queues is such that a lock should be granted in the future
3526 * or that a bast should be fired, because the new master will
3527 * shuffle the lists on this lockres as soon as it is migrated.
3528 */
3529void dlm_lockres_release_ast(struct dlm_ctxt *dlm,
3530 struct dlm_lock_resource *res)
3531{
3532 if (!atomic_dec_and_lock(&res->asts_reserved, &res->spinlock))
3533 return;
3534
3535 if (!res->migration_pending) {
3536 spin_unlock(&res->spinlock);
3537 return;
3538 }
3539
3540 BUG_ON(res->state & DLM_LOCK_RES_MIGRATING);
3541 res->migration_pending = 0;
3542 res->state |= DLM_LOCK_RES_MIGRATING;
3543 spin_unlock(&res->spinlock);
3544 wake_up(&res->wq);
3545 wake_up(&dlm->migration_wq);
3546}
5dad6c39
SE		 3547
3548void dlm_force_free_mles(struct dlm_ctxt *dlm)
3549{
3550 int i;
3551 struct hlist_head *bucket;
3552 struct dlm_master_list_entry *mle;
df53cd3b 3553 struct hlist_node *tmp;
5dad6c39
SE		 3554
3555 /*
3556 * We notified all other nodes that we are exiting the domain and
3557 * marked the dlm state to DLM_CTXT_LEAVING. If any mles are still
3558 * around we force free them and wake any processes that are waiting
3559 * on the mles
3560 */
3561 spin_lock(&dlm->spinlock);
3562 spin_lock(&dlm->master_lock);
3563
3564 BUG_ON(dlm->dlm_state != DLM_CTXT_LEAVING);
3565 BUG_ON((find_next_bit(dlm->domain_map, O2NM_MAX_NODES, 0) < O2NM_MAX_NODES));
3566
3567 for (i = 0; i < DLM_HASH_BUCKETS; i++) {
3568 bucket = dlm_master_hash(dlm, i);
df53cd3b 3569 hlist_for_each_entry_safe(mle, tmp, bucket, master_hash_node) {
5dad6c39
SE		 3570 if (mle->type != DLM_MLE_BLOCK) {
3571 mlog(ML_ERROR, "bad mle: %p\n", mle);
3572 dlm_print_one_mle(mle);
3573 }
3574 atomic_set(&mle->woken, 1);
3575 wake_up(&mle->wq);
3576
3577 __dlm_unlink_mle(dlm, mle);
3578 __dlm_mle_detach_hb_events(dlm, mle);
3579 __dlm_put_mle(mle);
3580 }
3581 }
3582 spin_unlock(&dlm->master_lock);
3583 spin_unlock(&dlm->spinlock);
3584}
Linux 6.x block layer and io_uring tree(s)