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ocfs2: do not return DLM_MIGRATE_RESPONSE_MASTERY_REF to avoid endless,loop during...
[linux-2.6-block.git] / fs / ocfs2 / dlm / dlmmaster.c
CommitLineData
6714d8e8
KH		 1/* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * dlmmod.c
5 *
6 * standalone DLM module
7 *
8 * Copyright (C) 2004 Oracle. All rights reserved.
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public
12 * License as published by the Free Software Foundation; either
13 * version 2 of the License, or (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public
21 * License along with this program; if not, write to the
22 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 * Boston, MA 021110-1307, USA.
24 *
25 */
26
27
28#include <linux/module.h>
29#include <linux/fs.h>
30#include <linux/types.h>
31#include <linux/slab.h>
32#include <linux/highmem.h>
6714d8e8
KH		 33#include <linux/init.h>
34#include <linux/sysctl.h>
35#include <linux/random.h>
36#include <linux/blkdev.h>
37#include <linux/socket.h>
38#include <linux/inet.h>
39#include <linux/spinlock.h>
40#include <linux/delay.h>
41
42
43#include "cluster/heartbeat.h"
44#include "cluster/nodemanager.h"
45#include "cluster/tcp.h"
46
47#include "dlmapi.h"
48#include "dlmcommon.h"
82353b59 49#include "dlmdomain.h"
e5a0334c 50#include "dlmdebug.h"
6714d8e8
KH		 51
52#define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_MASTER)
53#include "cluster/masklog.h"
54
6714d8e8
KH		 55static void dlm_mle_node_down(struct dlm_ctxt *dlm,
56 struct dlm_master_list_entry *mle,
57 struct o2nm_node *node,
58 int idx);
59static void dlm_mle_node_up(struct dlm_ctxt *dlm,
60 struct dlm_master_list_entry *mle,
61 struct o2nm_node *node,
62 int idx);
63
64static void dlm_assert_master_worker(struct dlm_work_item *item, void *data);
ba2bf218
KH		 65static int dlm_do_assert_master(struct dlm_ctxt *dlm,
66 struct dlm_lock_resource *res,
67 void *nodemap, u32 flags);
f3f85464 68static void dlm_deref_lockres_worker(struct dlm_work_item *item, void *data);
6714d8e8
KH		 69
70static inline int dlm_mle_equal(struct dlm_ctxt *dlm,
71 struct dlm_master_list_entry *mle,
72 const char *name,
73 unsigned int namelen)
74{
6714d8e8
KH		 75 if (dlm != mle->dlm)
76 return 0;
77
7141514b
SM		 78 if (namelen != mle->mnamelen ||
79 memcmp(name, mle->mname, namelen) != 0)
f77a9a78
SM		 80 return 0;
81
6714d8e8
KH		 82 return 1;
83}
84
1a5c4e2a
FF		 85static struct kmem_cache *dlm_lockres_cache;
86static struct kmem_cache *dlm_lockname_cache;
87static struct kmem_cache *dlm_mle_cache;
6714d8e8 88
6714d8e8
KH		 89static void dlm_mle_release(struct kref *kref);
90static void dlm_init_mle(struct dlm_master_list_entry *mle,
91 enum dlm_mle_type type,
92 struct dlm_ctxt *dlm,
93 struct dlm_lock_resource *res,
94 const char *name,
95 unsigned int namelen);
96static void dlm_put_mle(struct dlm_master_list_entry *mle);
97static void __dlm_put_mle(struct dlm_master_list_entry *mle);
98static int dlm_find_mle(struct dlm_ctxt *dlm,
99 struct dlm_master_list_entry **mle,
100 char *name, unsigned int namelen);
101
ba2bf218
KH		 102static int dlm_do_master_request(struct dlm_lock_resource *res,
103 struct dlm_master_list_entry *mle, int to);
6714d8e8
KH		 104
105
106static int dlm_wait_for_lock_mastery(struct dlm_ctxt *dlm,
107 struct dlm_lock_resource *res,
108 struct dlm_master_list_entry *mle,
109 int *blocked);
110static int dlm_restart_lock_mastery(struct dlm_ctxt *dlm,
111 struct dlm_lock_resource *res,
112 struct dlm_master_list_entry *mle,
113 int blocked);
114static int dlm_add_migration_mle(struct dlm_ctxt *dlm,
115 struct dlm_lock_resource *res,
116 struct dlm_master_list_entry *mle,
117 struct dlm_master_list_entry **oldmle,
118 const char *name, unsigned int namelen,
119 u8 new_master, u8 master);
120
121static u8 dlm_pick_migration_target(struct dlm_ctxt *dlm,
122 struct dlm_lock_resource *res);
123static void dlm_remove_nonlocal_locks(struct dlm_ctxt *dlm,
124 struct dlm_lock_resource *res);
125static int dlm_mark_lockres_migrating(struct dlm_ctxt *dlm,
126 struct dlm_lock_resource *res,
127 u8 target);
c03872f5
KH		 128static int dlm_pre_master_reco_lockres(struct dlm_ctxt *dlm,
129 struct dlm_lock_resource *res);
6714d8e8
KH		 130
131
132int dlm_is_host_down(int errno)
133{
134 switch (errno) {
135 case -EBADF:
136 case -ECONNREFUSED:
137 case -ENOTCONN:
138 case -ECONNRESET:
139 case -EPIPE:
140 case -EHOSTDOWN:
141 case -EHOSTUNREACH:
142 case -ETIMEDOUT:
143 case -ECONNABORTED:
144 case -ENETDOWN:
145 case -ENETUNREACH:
146 case -ENETRESET:
147 case -ESHUTDOWN:
148 case -ENOPROTOOPT:
149 case -EINVAL: /* if returned from our tcp code,
150 this means there is no socket */
151 return 1;
152 }
153 return 0;
154}
155
156
157/*
158 * MASTER LIST FUNCTIONS
159 */
160
161
162/*
163 * regarding master list entries and heartbeat callbacks:
164 *
165 * in order to avoid sleeping and allocation that occurs in
166 * heartbeat, master list entries are simply attached to the
167 * dlm's established heartbeat callbacks. the mle is attached
168 * when it is created, and since the dlm->spinlock is held at
169 * that time, any heartbeat event will be properly discovered
170 * by the mle. the mle needs to be detached from the
171 * dlm->mle_hb_events list as soon as heartbeat events are no
172 * longer useful to the mle, and before the mle is freed.
173 *
174 * as a general rule, heartbeat events are no longer needed by
175 * the mle once an "answer" regarding the lock master has been
176 * received.
177 */
178static inline void __dlm_mle_attach_hb_events(struct dlm_ctxt *dlm,
179 struct dlm_master_list_entry *mle)
180{
181 assert_spin_locked(&dlm->spinlock);
182
183 list_add_tail(&mle->hb_events, &dlm->mle_hb_events);
184}
185
186
187static inline void __dlm_mle_detach_hb_events(struct dlm_ctxt *dlm,
188 struct dlm_master_list_entry *mle)
189{
190 if (!list_empty(&mle->hb_events))
191 list_del_init(&mle->hb_events);
192}
193
194
195static inline void dlm_mle_detach_hb_events(struct dlm_ctxt *dlm,
196 struct dlm_master_list_entry *mle)
197{
198 spin_lock(&dlm->spinlock);
199 __dlm_mle_detach_hb_events(dlm, mle);
200 spin_unlock(&dlm->spinlock);
201}
202
a2bf0477
KH		 203static void dlm_get_mle_inuse(struct dlm_master_list_entry *mle)
204{
205 struct dlm_ctxt *dlm;
206 dlm = mle->dlm;
207
208 assert_spin_locked(&dlm->spinlock);
209 assert_spin_locked(&dlm->master_lock);
210 mle->inuse++;
211 kref_get(&mle->mle_refs);
212}
213
214static void dlm_put_mle_inuse(struct dlm_master_list_entry *mle)
215{
216 struct dlm_ctxt *dlm;
217 dlm = mle->dlm;
218
219 spin_lock(&dlm->spinlock);
220 spin_lock(&dlm->master_lock);
221 mle->inuse--;
222 __dlm_put_mle(mle);
223 spin_unlock(&dlm->master_lock);
224 spin_unlock(&dlm->spinlock);
225
226}
227
6714d8e8
KH		 228/* remove from list and free */
229static void __dlm_put_mle(struct dlm_master_list_entry *mle)
230{
231 struct dlm_ctxt *dlm;
232 dlm = mle->dlm;
233
234 assert_spin_locked(&dlm->spinlock);
235 assert_spin_locked(&dlm->master_lock);
aa852354
KH		 236 if (!atomic_read(&mle->mle_refs.refcount)) {
237 /* this may or may not crash, but who cares.
238 * it's a BUG. */
239 mlog(ML_ERROR, "bad mle: %p\n", mle);
240 dlm_print_one_mle(mle);
241 BUG();
242 } else
243 kref_put(&mle->mle_refs, dlm_mle_release);
6714d8e8
KH		 244}
245
246
247/* must not have any spinlocks coming in */
248static void dlm_put_mle(struct dlm_master_list_entry *mle)
249{
250 struct dlm_ctxt *dlm;
251 dlm = mle->dlm;
252
253 spin_lock(&dlm->spinlock);
254 spin_lock(&dlm->master_lock);
255 __dlm_put_mle(mle);
256 spin_unlock(&dlm->master_lock);
257 spin_unlock(&dlm->spinlock);
258}
259
260static inline void dlm_get_mle(struct dlm_master_list_entry *mle)
261{
262 kref_get(&mle->mle_refs);
263}
264
265static void dlm_init_mle(struct dlm_master_list_entry *mle,
266 enum dlm_mle_type type,
267 struct dlm_ctxt *dlm,
268 struct dlm_lock_resource *res,
269 const char *name,
270 unsigned int namelen)
271{
272 assert_spin_locked(&dlm->spinlock);
273
274 mle->dlm = dlm;
275 mle->type = type;
2ed6c750 276 INIT_HLIST_NODE(&mle->master_hash_node);
6714d8e8
KH		 277 INIT_LIST_HEAD(&mle->hb_events);
278 memset(mle->maybe_map, 0, sizeof(mle->maybe_map));
279 spin_lock_init(&mle->spinlock);
280 init_waitqueue_head(&mle->wq);
281 atomic_set(&mle->woken, 0);
282 kref_init(&mle->mle_refs);
283 memset(mle->response_map, 0, sizeof(mle->response_map));
284 mle->master = O2NM_MAX_NODES;
285 mle->new_master = O2NM_MAX_NODES;
a2bf0477 286 mle->inuse = 0;
6714d8e8 287
f77a9a78
SM		 288 BUG_ON(mle->type != DLM_MLE_BLOCK &&
289 mle->type != DLM_MLE_MASTER &&
290 mle->type != DLM_MLE_MIGRATION);
291
6714d8e8
KH		 292 if (mle->type == DLM_MLE_MASTER) {
293 BUG_ON(!res);
7141514b
SM		 294 mle->mleres = res;
295 memcpy(mle->mname, res->lockname.name, res->lockname.len);
296 mle->mnamelen = res->lockname.len;
297 mle->mnamehash = res->lockname.hash;
f77a9a78 298 } else {
6714d8e8 299 BUG_ON(!name);
7141514b
SM		 300 mle->mleres = NULL;
301 memcpy(mle->mname, name, namelen);
302 mle->mnamelen = namelen;
303 mle->mnamehash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 304 }
305
2041d8fd
SM		 306 atomic_inc(&dlm->mle_tot_count[mle->type]);
307 atomic_inc(&dlm->mle_cur_count[mle->type]);
308
6714d8e8
KH		 309 /* copy off the node_map and register hb callbacks on our copy */
310 memcpy(mle->node_map, dlm->domain_map, sizeof(mle->node_map));
311 memcpy(mle->vote_map, dlm->domain_map, sizeof(mle->vote_map));
312 clear_bit(dlm->node_num, mle->vote_map);
313 clear_bit(dlm->node_num, mle->node_map);
314
315 /* attach the mle to the domain node up/down events */
316 __dlm_mle_attach_hb_events(dlm, mle);
317}
318
1c084577
SM		 319void __dlm_unlink_mle(struct dlm_ctxt *dlm, struct dlm_master_list_entry *mle)
320{
321 assert_spin_locked(&dlm->spinlock);
322 assert_spin_locked(&dlm->master_lock);
323
2ed6c750
SM		 324 if (!hlist_unhashed(&mle->master_hash_node))
325 hlist_del_init(&mle->master_hash_node);
1c084577
SM		 326}
327
328void __dlm_insert_mle(struct dlm_ctxt *dlm, struct dlm_master_list_entry *mle)
329{
2ed6c750 330 struct hlist_head *bucket;
2ed6c750 331
1c084577
SM		 332 assert_spin_locked(&dlm->master_lock);
333
7141514b 334 bucket = dlm_master_hash(dlm, mle->mnamehash);
2ed6c750 335 hlist_add_head(&mle->master_hash_node, bucket);
1c084577 336}
6714d8e8
KH		 337
338/* returns 1 if found, 0 if not */
339static int dlm_find_mle(struct dlm_ctxt *dlm,
340 struct dlm_master_list_entry **mle,
341 char *name, unsigned int namelen)
342{
343 struct dlm_master_list_entry *tmpmle;
2ed6c750 344 struct hlist_head *bucket;
2ed6c750 345 unsigned int hash;
6714d8e8
KH		 346
347 assert_spin_locked(&dlm->master_lock);
348
2ed6c750
SM		 349 hash = dlm_lockid_hash(name, namelen);
350 bucket = dlm_master_hash(dlm, hash);
df53cd3b 351 hlist_for_each_entry(tmpmle, bucket, master_hash_node) {
6714d8e8
KH		 352 if (!dlm_mle_equal(dlm, tmpmle, name, namelen))
353 continue;
354 dlm_get_mle(tmpmle);
355 *mle = tmpmle;
356 return 1;
357 }
358 return 0;
359}
360
361void dlm_hb_event_notify_attached(struct dlm_ctxt *dlm, int idx, int node_up)
362{
363 struct dlm_master_list_entry *mle;
6714d8e8
KH		 364
365 assert_spin_locked(&dlm->spinlock);
2bd63216 366
800deef3 367 list_for_each_entry(mle, &dlm->mle_hb_events, hb_events) {
6714d8e8
KH		 368 if (node_up)
369 dlm_mle_node_up(dlm, mle, NULL, idx);
370 else
371 dlm_mle_node_down(dlm, mle, NULL, idx);
372 }
373}
374
375static void dlm_mle_node_down(struct dlm_ctxt *dlm,
376 struct dlm_master_list_entry *mle,
377 struct o2nm_node *node, int idx)
378{
379 spin_lock(&mle->spinlock);
380
381 if (!test_bit(idx, mle->node_map))
382 mlog(0, "node %u already removed from nodemap!\n", idx);
383 else
384 clear_bit(idx, mle->node_map);
385
386 spin_unlock(&mle->spinlock);
387}
388
389static void dlm_mle_node_up(struct dlm_ctxt *dlm,
390 struct dlm_master_list_entry *mle,
391 struct o2nm_node *node, int idx)
392{
393 spin_lock(&mle->spinlock);
394
395 if (test_bit(idx, mle->node_map))
396 mlog(0, "node %u already in node map!\n", idx);
397 else
398 set_bit(idx, mle->node_map);
399
400 spin_unlock(&mle->spinlock);
401}
402
403
404int dlm_init_mle_cache(void)
405{
12eb0035 406 dlm_mle_cache = kmem_cache_create("o2dlm_mle",
6714d8e8
KH		 407 sizeof(struct dlm_master_list_entry),
408 0, SLAB_HWCACHE_ALIGN,
20c2df83 409 NULL);
6714d8e8
KH		 410 if (dlm_mle_cache == NULL)
411 return -ENOMEM;
412 return 0;
413}
414
415void dlm_destroy_mle_cache(void)
416{
417 if (dlm_mle_cache)
418 kmem_cache_destroy(dlm_mle_cache);
419}
420
421static void dlm_mle_release(struct kref *kref)
422{
423 struct dlm_master_list_entry *mle;
424 struct dlm_ctxt *dlm;
425
6714d8e8
KH		 426 mle = container_of(kref, struct dlm_master_list_entry, mle_refs);
427 dlm = mle->dlm;
428
6714d8e8
KH		 429 assert_spin_locked(&dlm->spinlock);
430 assert_spin_locked(&dlm->master_lock);
431
7141514b
SM		 432 mlog(0, "Releasing mle for %.*s, type %d\n", mle->mnamelen, mle->mname,
433 mle->type);
2ed6c750 434
6714d8e8 435 /* remove from list if not already */
1c084577 436 __dlm_unlink_mle(dlm, mle);
6714d8e8
KH		 437
438 /* detach the mle from the domain node up/down events */
439 __dlm_mle_detach_hb_events(dlm, mle);
440
2041d8fd
SM		 441 atomic_dec(&dlm->mle_cur_count[mle->type]);
442
6714d8e8
KH		 443 /* NOTE: kfree under spinlock here.
444 * if this is bad, we can move this to a freelist. */
445 kmem_cache_free(dlm_mle_cache, mle);
446}
447
448
449/*
450 * LOCK RESOURCE FUNCTIONS
451 */
452
724bdca9
SM		 453int dlm_init_master_caches(void)
454{
455 dlm_lockres_cache = kmem_cache_create("o2dlm_lockres",
456 sizeof(struct dlm_lock_resource),
457 0, SLAB_HWCACHE_ALIGN, NULL);
458 if (!dlm_lockres_cache)
459 goto bail;
460
461 dlm_lockname_cache = kmem_cache_create("o2dlm_lockname",
462 DLM_LOCKID_NAME_MAX, 0,
463 SLAB_HWCACHE_ALIGN, NULL);
464 if (!dlm_lockname_cache)
465 goto bail;
466
467 return 0;
468bail:
469 dlm_destroy_master_caches();
470 return -ENOMEM;
471}
472
473void dlm_destroy_master_caches(void)
474{
66db6cfd 475 if (dlm_lockname_cache) {
724bdca9 476 kmem_cache_destroy(dlm_lockname_cache);
66db6cfd
JQ		 477 dlm_lockname_cache = NULL;
478 }
724bdca9 479
66db6cfd 480 if (dlm_lockres_cache) {
724bdca9 481 kmem_cache_destroy(dlm_lockres_cache);
66db6cfd
JQ		 482 dlm_lockres_cache = NULL;
483 }
724bdca9
SM		 484}
485
6714d8e8
KH		 486static void dlm_lockres_release(struct kref *kref)
487{
488 struct dlm_lock_resource *res;
b0d4f817 489 struct dlm_ctxt *dlm;
6714d8e8
KH		 490
491 res = container_of(kref, struct dlm_lock_resource, refs);
b0d4f817 492 dlm = res->dlm;
6714d8e8
KH		 493
494 /* This should not happen -- all lockres' have a name
495 * associated with them at init time. */
496 BUG_ON(!res->lockname.name);
497
498 mlog(0, "destroying lockres %.*s\n", res->lockname.len,
499 res->lockname.name);
500
b0d4f817 501 spin_lock(&dlm->track_lock);
29576f8b
SM		 502 if (!list_empty(&res->tracking))
503 list_del_init(&res->tracking);
504 else {
505 mlog(ML_ERROR, "Resource %.*s not on the Tracking list\n",
506 res->lockname.len, res->lockname.name);
507 dlm_print_one_lock_resource(res);
508 }
b0d4f817
SM		 509 spin_unlock(&dlm->track_lock);
510
6800791a
SM		 511 atomic_dec(&dlm->res_cur_count);
512
a7f90d83
KH		 513 if (!hlist_unhashed(&res->hash_node) ||
514 !list_empty(&res->granted) ||
515 !list_empty(&res->converting) ||
516 !list_empty(&res->blocked) ||
517 !list_empty(&res->dirty) ||
518 !list_empty(&res->recovering) ||
519 !list_empty(&res->purge)) {
520 mlog(ML_ERROR,
521 "Going to BUG for resource %.*s."
522 " We're on a list! [%c%c%c%c%c%c%c]\n",
523 res->lockname.len, res->lockname.name,
524 !hlist_unhashed(&res->hash_node) ? 'H' : ' ',
525 !list_empty(&res->granted) ? 'G' : ' ',
526 !list_empty(&res->converting) ? 'C' : ' ',
527 !list_empty(&res->blocked) ? 'B' : ' ',
528 !list_empty(&res->dirty) ? 'D' : ' ',
529 !list_empty(&res->recovering) ? 'R' : ' ',
530 !list_empty(&res->purge) ? 'P' : ' ');
531
532 dlm_print_one_lock_resource(res);
533 }
534
6714d8e8
KH		 535 /* By the time we're ready to blow this guy away, we shouldn't
536 * be on any lists. */
81f2094a 537 BUG_ON(!hlist_unhashed(&res->hash_node));
6714d8e8
KH		 538 BUG_ON(!list_empty(&res->granted));
539 BUG_ON(!list_empty(&res->converting));
540 BUG_ON(!list_empty(&res->blocked));
541 BUG_ON(!list_empty(&res->dirty));
542 BUG_ON(!list_empty(&res->recovering));
543 BUG_ON(!list_empty(&res->purge));
544
724bdca9 545 kmem_cache_free(dlm_lockname_cache, (void *)res->lockname.name);
6714d8e8 546
724bdca9 547 kmem_cache_free(dlm_lockres_cache, res);
6714d8e8
KH		 548}
549
6714d8e8
KH		 550void dlm_lockres_put(struct dlm_lock_resource *res)
551{
552 kref_put(&res->refs, dlm_lockres_release);
553}
554
555static void dlm_init_lockres(struct dlm_ctxt *dlm,
556 struct dlm_lock_resource *res,
557 const char *name, unsigned int namelen)
558{
559 char *qname;
560
561 /* If we memset here, we lose our reference to the kmalloc'd
562 * res->lockname.name, so be sure to init every field
563 * correctly! */
564
565 qname = (char *) res->lockname.name;
566 memcpy(qname, name, namelen);
567
568 res->lockname.len = namelen;
a3d33291 569 res->lockname.hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 570
571 init_waitqueue_head(&res->wq);
572 spin_lock_init(&res->spinlock);
81f2094a 573 INIT_HLIST_NODE(&res->hash_node);
6714d8e8
KH		 574 INIT_LIST_HEAD(&res->granted);
575 INIT_LIST_HEAD(&res->converting);
576 INIT_LIST_HEAD(&res->blocked);
577 INIT_LIST_HEAD(&res->dirty);
578 INIT_LIST_HEAD(&res->recovering);
579 INIT_LIST_HEAD(&res->purge);
29576f8b 580 INIT_LIST_HEAD(&res->tracking);
6714d8e8
KH		 581 atomic_set(&res->asts_reserved, 0);
582 res->migration_pending = 0;
ba2bf218 583 res->inflight_locks = 0;
6714d8e8 584
b0d4f817
SM		 585 res->dlm = dlm;
586
6714d8e8
KH		 587 kref_init(&res->refs);
588
6800791a
SM		 589 atomic_inc(&dlm->res_tot_count);
590 atomic_inc(&dlm->res_cur_count);
591
6714d8e8
KH		 592 /* just for consistency */
593 spin_lock(&res->spinlock);
594 dlm_set_lockres_owner(dlm, res, DLM_LOCK_RES_OWNER_UNKNOWN);
595 spin_unlock(&res->spinlock);
596
597 res->state = DLM_LOCK_RES_IN_PROGRESS;
598
599 res->last_used = 0;
600
18c6ac38 601 spin_lock(&dlm->spinlock);
29576f8b 602 list_add_tail(&res->tracking, &dlm->tracking_list);
18c6ac38 603 spin_unlock(&dlm->spinlock);
29576f8b 604
6714d8e8 605 memset(res->lvb, 0, DLM_LVB_LEN);
ba2bf218 606 memset(res->refmap, 0, sizeof(res->refmap));
6714d8e8
KH		 607}
608
609struct dlm_lock_resource *dlm_new_lockres(struct dlm_ctxt *dlm,
610 const char *name,
611 unsigned int namelen)
612{
724bdca9 613 struct dlm_lock_resource *res = NULL;
6714d8e8 614
3914ed0c 615 res = kmem_cache_zalloc(dlm_lockres_cache, GFP_NOFS);
6714d8e8 616 if (!res)
724bdca9 617 goto error;
6714d8e8 618
3914ed0c 619 res->lockname.name = kmem_cache_zalloc(dlm_lockname_cache, GFP_NOFS);
724bdca9
SM		 620 if (!res->lockname.name)
621 goto error;
6714d8e8
KH		 622
623 dlm_init_lockres(dlm, res, name, namelen);
624 return res;
724bdca9
SM		 625
626error:
627 if (res && res->lockname.name)
628 kmem_cache_free(dlm_lockname_cache, (void *)res->lockname.name);
629
630 if (res)
631 kmem_cache_free(dlm_lockres_cache, res);
632 return NULL;
6714d8e8
KH		 633}
634
8d400b81
SM		 635void dlm_lockres_set_refmap_bit(struct dlm_ctxt *dlm,
636 struct dlm_lock_resource *res, int bit)
ba2bf218 637{
8d400b81
SM		 638 assert_spin_locked(&res->spinlock);
639
640 mlog(0, "res %.*s, set node %u, %ps()\n", res->lockname.len,
641 res->lockname.name, bit, __builtin_return_address(0));
642
643 set_bit(bit, res->refmap);
644}
645
646void dlm_lockres_clear_refmap_bit(struct dlm_ctxt *dlm,
647 struct dlm_lock_resource *res, int bit)
648{
649 assert_spin_locked(&res->spinlock);
650
651 mlog(0, "res %.*s, clr node %u, %ps()\n", res->lockname.len,
652 res->lockname.name, bit, __builtin_return_address(0));
653
654 clear_bit(bit, res->refmap);
655}
656
657
658void dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm,
659 struct dlm_lock_resource *res)
660{
661 assert_spin_locked(&res->spinlock);
ba2bf218 662
ba2bf218 663 res->inflight_locks++;
ff0a522e 664
8d400b81
SM		 665 mlog(0, "%s: res %.*s, inflight++: now %u, %ps()\n", dlm->name,
666 res->lockname.len, res->lockname.name, res->inflight_locks,
667 __builtin_return_address(0));
ba2bf218
KH		 668}
669
8d400b81
SM		 670void dlm_lockres_drop_inflight_ref(struct dlm_ctxt *dlm,
671 struct dlm_lock_resource *res)
ba2bf218
KH		 672{
673 assert_spin_locked(&res->spinlock);
674
675 BUG_ON(res->inflight_locks == 0);
8d400b81 676
ba2bf218 677 res->inflight_locks--;
ff0a522e 678
8d400b81
SM		 679 mlog(0, "%s: res %.*s, inflight--: now %u, %ps()\n", dlm->name,
680 res->lockname.len, res->lockname.name, res->inflight_locks,
681 __builtin_return_address(0));
682
ba2bf218
KH		 683 wake_up(&res->wq);
684}
685
6714d8e8
KH		 686/*
687 * lookup a lock resource by name.
688 * may already exist in the hashtable.
689 * lockid is null terminated
690 *
691 * if not, allocate enough for the lockres and for
692 * the temporary structure used in doing the mastering.
693 *
694 * also, do a lookup in the dlm->master_list to see
695 * if another node has begun mastering the same lock.
696 * if so, there should be a block entry in there
697 * for this name, and we should *not* attempt to master
698 * the lock here. need to wait around for that node
699 * to assert_master (or die).
700 *
701 */
702struct dlm_lock_resource * dlm_get_lock_resource(struct dlm_ctxt *dlm,
703 const char *lockid,
3384f3df 704 int namelen,
6714d8e8
KH		 705 int flags)
706{
707 struct dlm_lock_resource *tmpres=NULL, *res=NULL;
708 struct dlm_master_list_entry *mle = NULL;
709 struct dlm_master_list_entry *alloc_mle = NULL;
710 int blocked = 0;
711 int ret, nodenum;
712 struct dlm_node_iter iter;
3384f3df 713 unsigned int hash;
6714d8e8 714 int tries = 0;
c03872f5 715 int bit, wait_on_recovery = 0;
6714d8e8
KH		 716
717 BUG_ON(!lockid);
718
a3d33291 719 hash = dlm_lockid_hash(lockid, namelen);
6714d8e8
KH		 720
721 mlog(0, "get lockres %s (len %d)\n", lockid, namelen);
722
723lookup:
724 spin_lock(&dlm->spinlock);
ba2bf218 725 tmpres = __dlm_lookup_lockres_full(dlm, lockid, namelen, hash);
6714d8e8 726 if (tmpres) {
7b791d68 727 spin_unlock(&dlm->spinlock);
ba2bf218 728 spin_lock(&tmpres->spinlock);
ff0a522e 729 /* Wait on the thread that is mastering the resource */
7b791d68
SM		 730 if (tmpres->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
731 __dlm_wait_on_lockres(tmpres);
732 BUG_ON(tmpres->owner == DLM_LOCK_RES_OWNER_UNKNOWN);
ff0a522e
SM		 733 spin_unlock(&tmpres->spinlock);
734 dlm_lockres_put(tmpres);
735 tmpres = NULL;
736 goto lookup;
7b791d68
SM		 737 }
738
ff0a522e
SM		 739 /* Wait on the resource purge to complete before continuing */
740 if (tmpres->state & DLM_LOCK_RES_DROPPING_REF) {
741 BUG_ON(tmpres->owner == dlm->node_num);
742 __dlm_wait_on_lockres_flags(tmpres,
743 DLM_LOCK_RES_DROPPING_REF);
ba2bf218
KH		 744 spin_unlock(&tmpres->spinlock);
745 dlm_lockres_put(tmpres);
746 tmpres = NULL;
747 goto lookup;
748 }
749
ff0a522e
SM		 750 /* Grab inflight ref to pin the resource */
751 dlm_lockres_grab_inflight_ref(dlm, tmpres);
752
753 spin_unlock(&tmpres->spinlock);
6714d8e8
KH		 754 if (res)
755 dlm_lockres_put(res);
756 res = tmpres;
757 goto leave;
758 }
759
760 if (!res) {
761 spin_unlock(&dlm->spinlock);
762 mlog(0, "allocating a new resource\n");
763 /* nothing found and we need to allocate one. */
3914ed0c 764 alloc_mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
6714d8e8
KH		 765 if (!alloc_mle)
766 goto leave;
767 res = dlm_new_lockres(dlm, lockid, namelen);
768 if (!res)
769 goto leave;
770 goto lookup;
771 }
772
773 mlog(0, "no lockres found, allocated our own: %p\n", res);
774
775 if (flags & LKM_LOCAL) {
776 /* caller knows it's safe to assume it's not mastered elsewhere
777 * DONE! return right away */
778 spin_lock(&res->spinlock);
779 dlm_change_lockres_owner(dlm, res, dlm->node_num);
780 __dlm_insert_lockres(dlm, res);
ba2bf218 781 dlm_lockres_grab_inflight_ref(dlm, res);
6714d8e8
KH		 782 spin_unlock(&res->spinlock);
783 spin_unlock(&dlm->spinlock);
784 /* lockres still marked IN_PROGRESS */
785 goto wake_waiters;
786 }
787
788 /* check master list to see if another node has started mastering it */
789 spin_lock(&dlm->master_lock);
790
791 /* if we found a block, wait for lock to be mastered by another node */
792 blocked = dlm_find_mle(dlm, &mle, (char *)lockid, namelen);
793 if (blocked) {
ba2bf218 794 int mig;
6714d8e8
KH		 795 if (mle->type == DLM_MLE_MASTER) {
796 mlog(ML_ERROR, "master entry for nonexistent lock!\n");
797 BUG();
ba2bf218
KH		 798 }
799 mig = (mle->type == DLM_MLE_MIGRATION);
800 /* if there is a migration in progress, let the migration
801 * finish before continuing. we can wait for the absence
802 * of the MIGRATION mle: either the migrate finished or
803 * one of the nodes died and the mle was cleaned up.
804 * if there is a BLOCK here, but it already has a master
805 * set, we are too late. the master does not have a ref
806 * for us in the refmap. detach the mle and drop it.
807 * either way, go back to the top and start over. */
808 if (mig || mle->master != O2NM_MAX_NODES) {
809 BUG_ON(mig && mle->master == dlm->node_num);
810 /* we arrived too late. the master does not
811 * have a ref for us. retry. */
812 mlog(0, "%s:%.*s: late on %s\n",
813 dlm->name, namelen, lockid,
814 mig ? "MIGRATION" : "BLOCK");
6714d8e8 815 spin_unlock(&dlm->master_lock);
6714d8e8
KH		 816 spin_unlock(&dlm->spinlock);
817
818 /* master is known, detach */
ba2bf218
KH		 819 if (!mig)
820 dlm_mle_detach_hb_events(dlm, mle);
6714d8e8
KH		 821 dlm_put_mle(mle);
822 mle = NULL;
25985edc 823 /* this is lame, but we can't wait on either
ba2bf218
KH		 824 * the mle or lockres waitqueue here */
825 if (mig)
826 msleep(100);
827 goto lookup;
6714d8e8
KH		 828 }
829 } else {
830 /* go ahead and try to master lock on this node */
831 mle = alloc_mle;
832 /* make sure this does not get freed below */
833 alloc_mle = NULL;
834 dlm_init_mle(mle, DLM_MLE_MASTER, dlm, res, NULL, 0);
835 set_bit(dlm->node_num, mle->maybe_map);
1c084577 836 __dlm_insert_mle(dlm, mle);
c03872f5
KH		 837
838 /* still holding the dlm spinlock, check the recovery map
2bd63216 839 * to see if there are any nodes that still need to be
c03872f5
KH		 840 * considered. these will not appear in the mle nodemap
841 * but they might own this lockres. wait on them. */
842 bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0);
843 if (bit < O2NM_MAX_NODES) {
8decab3c
SM		 844 mlog(0, "%s: res %.*s, At least one node (%d) "
845 "to recover before lock mastery can begin\n",
c03872f5
KH		 846 dlm->name, namelen, (char *)lockid, bit);
847 wait_on_recovery = 1;
848 }
6714d8e8
KH		 849 }
850
851 /* at this point there is either a DLM_MLE_BLOCK or a
852 * DLM_MLE_MASTER on the master list, so it's safe to add the
853 * lockres to the hashtable. anyone who finds the lock will
854 * still have to wait on the IN_PROGRESS. */
855
856 /* finally add the lockres to its hash bucket */
857 __dlm_insert_lockres(dlm, res);
8d400b81 858
ff0a522e 859 /* Grab inflight ref to pin the resource */
8d400b81
SM		 860 spin_lock(&res->spinlock);
861 dlm_lockres_grab_inflight_ref(dlm, res);
862 spin_unlock(&res->spinlock);
ba2bf218 863
6714d8e8
KH		 864 /* get an extra ref on the mle in case this is a BLOCK
865 * if so, the creator of the BLOCK may try to put the last
866 * ref at this time in the assert master handler, so we
867 * need an extra one to keep from a bad ptr deref. */
a2bf0477 868 dlm_get_mle_inuse(mle);
6714d8e8
KH		 869 spin_unlock(&dlm->master_lock);
870 spin_unlock(&dlm->spinlock);
871
e7e69eb3 872redo_request:
c03872f5
KH		 873 while (wait_on_recovery) {
874 /* any cluster changes that occurred after dropping the
875 * dlm spinlock would be detectable be a change on the mle,
876 * so we only need to clear out the recovery map once. */
877 if (dlm_is_recovery_lock(lockid, namelen)) {
8decab3c
SM		 878 mlog(0, "%s: Recovery map is not empty, but must "
879 "master $RECOVERY lock now\n", dlm->name);
c03872f5
KH		 880 if (!dlm_pre_master_reco_lockres(dlm, res))
881 wait_on_recovery = 0;
882 else {
883 mlog(0, "%s: waiting 500ms for heartbeat state "
884 "change\n", dlm->name);
885 msleep(500);
886 }
887 continue;
2bd63216 888 }
c03872f5
KH		 889
890 dlm_kick_recovery_thread(dlm);
aa087b84 891 msleep(1000);
c03872f5
KH		 892 dlm_wait_for_recovery(dlm);
893
894 spin_lock(&dlm->spinlock);
895 bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0);
896 if (bit < O2NM_MAX_NODES) {
8decab3c
SM		 897 mlog(0, "%s: res %.*s, At least one node (%d) "
898 "to recover before lock mastery can begin\n",
c03872f5
KH		 899 dlm->name, namelen, (char *)lockid, bit);
900 wait_on_recovery = 1;
901 } else
902 wait_on_recovery = 0;
903 spin_unlock(&dlm->spinlock);
b7084ab5
KH		 904
905 if (wait_on_recovery)
906 dlm_wait_for_node_recovery(dlm, bit, 10000);
c03872f5
KH		 907 }
908
6714d8e8
KH		 909 /* must wait for lock to be mastered elsewhere */
910 if (blocked)
911 goto wait;
912
6714d8e8
KH		 913 ret = -EINVAL;
914 dlm_node_iter_init(mle->vote_map, &iter);
915 while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
ba2bf218 916 ret = dlm_do_master_request(res, mle, nodenum);
6714d8e8
KH		 917 if (ret < 0)
918 mlog_errno(ret);
919 if (mle->master != O2NM_MAX_NODES) {
920 /* found a master ! */
9c6510a5
KH		 921 if (mle->master <= nodenum)
922 break;
923 /* if our master request has not reached the master
924 * yet, keep going until it does. this is how the
925 * master will know that asserts are needed back to
926 * the lower nodes. */
8decab3c
SM		 927 mlog(0, "%s: res %.*s, Requests only up to %u but "
928 "master is %u, keep going\n", dlm->name, namelen,
9c6510a5 929 lockid, nodenum, mle->master);
6714d8e8
KH		 930 }
931 }
932
933wait:
934 /* keep going until the response map includes all nodes */
935 ret = dlm_wait_for_lock_mastery(dlm, res, mle, &blocked);
936 if (ret < 0) {
e7e69eb3 937 wait_on_recovery = 1;
8decab3c
SM		 938 mlog(0, "%s: res %.*s, Node map changed, redo the master "
939 "request now, blocked=%d\n", dlm->name, res->lockname.len,
6714d8e8
KH		 940 res->lockname.name, blocked);
941 if (++tries > 20) {
8decab3c
SM		 942 mlog(ML_ERROR, "%s: res %.*s, Spinning on "
943 "dlm_wait_for_lock_mastery, blocked = %d\n",
2bd63216 944 dlm->name, res->lockname.len,
6714d8e8
KH		 945 res->lockname.name, blocked);
946 dlm_print_one_lock_resource(res);
8a9343fa 947 dlm_print_one_mle(mle);
6714d8e8
KH		 948 tries = 0;
949 }
950 goto redo_request;
951 }
952
8decab3c
SM		 953 mlog(0, "%s: res %.*s, Mastered by %u\n", dlm->name, res->lockname.len,
954 res->lockname.name, res->owner);
6714d8e8
KH		 955 /* make sure we never continue without this */
956 BUG_ON(res->owner == O2NM_MAX_NODES);
957
958 /* master is known, detach if not already detached */
959 dlm_mle_detach_hb_events(dlm, mle);
960 dlm_put_mle(mle);
961 /* put the extra ref */
a2bf0477 962 dlm_put_mle_inuse(mle);
6714d8e8
KH		 963
964wake_waiters:
965 spin_lock(&res->spinlock);
966 res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
967 spin_unlock(&res->spinlock);
968 wake_up(&res->wq);
969
970leave:
971 /* need to free the unused mle */
972 if (alloc_mle)
973 kmem_cache_free(dlm_mle_cache, alloc_mle);
974
975 return res;
976}
977
978
979#define DLM_MASTERY_TIMEOUT_MS 5000
980
981static int dlm_wait_for_lock_mastery(struct dlm_ctxt *dlm,
982 struct dlm_lock_resource *res,
983 struct dlm_master_list_entry *mle,
984 int *blocked)
985{
986 u8 m;
987 int ret, bit;
988 int map_changed, voting_done;
989 int assert, sleep;
990
991recheck:
992 ret = 0;
993 assert = 0;
994
995 /* check if another node has already become the owner */
996 spin_lock(&res->spinlock);
997 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
9c6510a5
KH		 998 mlog(0, "%s:%.*s: owner is suddenly %u\n", dlm->name,
999 res->lockname.len, res->lockname.name, res->owner);
6714d8e8 1000 spin_unlock(&res->spinlock);
9c6510a5
KH		 1001 /* this will cause the master to re-assert across
1002 * the whole cluster, freeing up mles */
588e0090 1003 if (res->owner != dlm->node_num) {
ba2bf218 1004 ret = dlm_do_master_request(res, mle, res->owner);
588e0090
KH		 1005 if (ret < 0) {
1006 /* give recovery a chance to run */
1007 mlog(ML_ERROR, "link to %u went down?: %d\n", res->owner, ret);
1008 msleep(500);
1009 goto recheck;
1010 }
9c6510a5
KH		 1011 }
1012 ret = 0;
6714d8e8
KH		 1013 goto leave;
1014 }
1015 spin_unlock(&res->spinlock);
1016
1017 spin_lock(&mle->spinlock);
1018 m = mle->master;
1019 map_changed = (memcmp(mle->vote_map, mle->node_map,
1020 sizeof(mle->vote_map)) != 0);
1021 voting_done = (memcmp(mle->vote_map, mle->response_map,
1022 sizeof(mle->vote_map)) == 0);
1023
1024 /* restart if we hit any errors */
1025 if (map_changed) {
1026 int b;
1027 mlog(0, "%s: %.*s: node map changed, restarting\n",
1028 dlm->name, res->lockname.len, res->lockname.name);
1029 ret = dlm_restart_lock_mastery(dlm, res, mle, *blocked);
1030 b = (mle->type == DLM_MLE_BLOCK);
1031 if ((*blocked && !b) || (!*blocked && b)) {
2bd63216 1032 mlog(0, "%s:%.*s: status change: old=%d new=%d\n",
6714d8e8
KH		 1033 dlm->name, res->lockname.len, res->lockname.name,
1034 *blocked, b);
1035 *blocked = b;
1036 }
1037 spin_unlock(&mle->spinlock);
1038 if (ret < 0) {
1039 mlog_errno(ret);
1040 goto leave;
1041 }
1042 mlog(0, "%s:%.*s: restart lock mastery succeeded, "
1043 "rechecking now\n", dlm->name, res->lockname.len,
1044 res->lockname.name);
1045 goto recheck;
aa852354
KH		 1046 } else {
1047 if (!voting_done) {
1048 mlog(0, "map not changed and voting not done "
1049 "for %s:%.*s\n", dlm->name, res->lockname.len,
1050 res->lockname.name);
1051 }
6714d8e8
KH		 1052 }
1053
1054 if (m != O2NM_MAX_NODES) {
1055 /* another node has done an assert!
1056 * all done! */
1057 sleep = 0;
1058 } else {
1059 sleep = 1;
1060 /* have all nodes responded? */
1061 if (voting_done && !*blocked) {
1062 bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0);
1063 if (dlm->node_num <= bit) {
1064 /* my node number is lowest.
1065 * now tell other nodes that I am
1066 * mastering this. */
1067 mle->master = dlm->node_num;
ba2bf218
KH		 1068 /* ref was grabbed in get_lock_resource
1069 * will be dropped in dlmlock_master */
6714d8e8
KH		 1070 assert = 1;
1071 sleep = 0;
1072 }
1073 /* if voting is done, but we have not received
1074 * an assert master yet, we must sleep */
1075 }
1076 }
1077
1078 spin_unlock(&mle->spinlock);
1079
1080 /* sleep if we haven't finished voting yet */
1081 if (sleep) {
1082 unsigned long timeo = msecs_to_jiffies(DLM_MASTERY_TIMEOUT_MS);
1083
1084 /*
1085 if (atomic_read(&mle->mle_refs.refcount) < 2)
1086 mlog(ML_ERROR, "mle (%p) refs=%d, name=%.*s\n", mle,
1087 atomic_read(&mle->mle_refs.refcount),
1088 res->lockname.len, res->lockname.name);
1089 */
1090 atomic_set(&mle->woken, 0);
1091 (void)wait_event_timeout(mle->wq,
1092 (atomic_read(&mle->woken) == 1),
1093 timeo);
1094 if (res->owner == O2NM_MAX_NODES) {
ba2bf218
KH		 1095 mlog(0, "%s:%.*s: waiting again\n", dlm->name,
1096 res->lockname.len, res->lockname.name);
6714d8e8
KH		 1097 goto recheck;
1098 }
1099 mlog(0, "done waiting, master is %u\n", res->owner);
1100 ret = 0;
1101 goto leave;
1102 }
1103
1104 ret = 0; /* done */
1105 if (assert) {
1106 m = dlm->node_num;
1107 mlog(0, "about to master %.*s here, this=%u\n",
1108 res->lockname.len, res->lockname.name, m);
ba2bf218 1109 ret = dlm_do_assert_master(dlm, res, mle->vote_map, 0);
6714d8e8
KH		 1110 if (ret) {
1111 /* This is a failure in the network path,
1112 * not in the response to the assert_master
1113 * (any nonzero response is a BUG on this node).
1114 * Most likely a socket just got disconnected
1115 * due to node death. */
1116 mlog_errno(ret);
1117 }
1118 /* no longer need to restart lock mastery.
1119 * all living nodes have been contacted. */
1120 ret = 0;
1121 }
1122
1123 /* set the lockres owner */
1124 spin_lock(&res->spinlock);
ba2bf218
KH		 1125 /* mastery reference obtained either during
1126 * assert_master_handler or in get_lock_resource */
6714d8e8
KH		 1127 dlm_change_lockres_owner(dlm, res, m);
1128 spin_unlock(&res->spinlock);
1129
1130leave:
1131 return ret;
1132}
1133
1134struct dlm_bitmap_diff_iter
1135{
1136 int curnode;
1137 unsigned long *orig_bm;
1138 unsigned long *cur_bm;
1139 unsigned long diff_bm[BITS_TO_LONGS(O2NM_MAX_NODES)];
1140};
1141
1142enum dlm_node_state_change
1143{
1144 NODE_DOWN = -1,
1145 NODE_NO_CHANGE = 0,
1146 NODE_UP
1147};
1148
1149static void dlm_bitmap_diff_iter_init(struct dlm_bitmap_diff_iter *iter,
1150 unsigned long *orig_bm,
1151 unsigned long *cur_bm)
1152{
1153 unsigned long p1, p2;
1154 int i;
1155
1156 iter->curnode = -1;
1157 iter->orig_bm = orig_bm;
1158 iter->cur_bm = cur_bm;
1159
1160 for (i = 0; i < BITS_TO_LONGS(O2NM_MAX_NODES); i++) {
1161 p1 = *(iter->orig_bm + i);
1162 p2 = *(iter->cur_bm + i);
1163 iter->diff_bm[i] = (p1 & ~p2) | (p2 & ~p1);
1164 }
1165}
1166
1167static int dlm_bitmap_diff_iter_next(struct dlm_bitmap_diff_iter *iter,
1168 enum dlm_node_state_change *state)
1169{
1170 int bit;
1171
1172 if (iter->curnode >= O2NM_MAX_NODES)
1173 return -ENOENT;
1174
1175 bit = find_next_bit(iter->diff_bm, O2NM_MAX_NODES,
1176 iter->curnode+1);
1177 if (bit >= O2NM_MAX_NODES) {
1178 iter->curnode = O2NM_MAX_NODES;
1179 return -ENOENT;
1180 }
1181
1182 /* if it was there in the original then this node died */
1183 if (test_bit(bit, iter->orig_bm))
1184 *state = NODE_DOWN;
1185 else
1186 *state = NODE_UP;
1187
1188 iter->curnode = bit;
1189 return bit;
1190}
1191
1192
1193static int dlm_restart_lock_mastery(struct dlm_ctxt *dlm,
1194 struct dlm_lock_resource *res,
1195 struct dlm_master_list_entry *mle,
1196 int blocked)
1197{
1198 struct dlm_bitmap_diff_iter bdi;
1199 enum dlm_node_state_change sc;
1200 int node;
1201 int ret = 0;
1202
1203 mlog(0, "something happened such that the "
1204 "master process may need to be restarted!\n");
1205
1206 assert_spin_locked(&mle->spinlock);
1207
1208 dlm_bitmap_diff_iter_init(&bdi, mle->vote_map, mle->node_map);
1209 node = dlm_bitmap_diff_iter_next(&bdi, &sc);
1210 while (node >= 0) {
1211 if (sc == NODE_UP) {
e2faea4c
KH		 1212 /* a node came up. clear any old vote from
1213 * the response map and set it in the vote map
1214 * then restart the mastery. */
1215 mlog(ML_NOTICE, "node %d up while restarting\n", node);
6714d8e8
KH		 1216
1217 /* redo the master request, but only for the new node */
1218 mlog(0, "sending request to new node\n");
1219 clear_bit(node, mle->response_map);
1220 set_bit(node, mle->vote_map);
1221 } else {
1222 mlog(ML_ERROR, "node down! %d\n", node);
6714d8e8
KH		 1223 if (blocked) {
1224 int lowest = find_next_bit(mle->maybe_map,
1225 O2NM_MAX_NODES, 0);
1226
1227 /* act like it was never there */
1228 clear_bit(node, mle->maybe_map);
1229
e7e69eb3
KH		 1230 if (node == lowest) {
1231 mlog(0, "expected master %u died"
1232 " while this node was blocked "
1233 "waiting on it!\n", node);
1234 lowest = find_next_bit(mle->maybe_map,
1235 O2NM_MAX_NODES,
1236 lowest+1);
1237 if (lowest < O2NM_MAX_NODES) {
1238 mlog(0, "%s:%.*s:still "
1239 "blocked. waiting on %u "
1240 "now\n", dlm->name,
1241 res->lockname.len,
1242 res->lockname.name,
1243 lowest);
1244 } else {
1245 /* mle is an MLE_BLOCK, but
1246 * there is now nothing left to
1247 * block on. we need to return
1248 * all the way back out and try
1249 * again with an MLE_MASTER.
1250 * dlm_do_local_recovery_cleanup
1251 * has already run, so the mle
1252 * refcount is ok */
1253 mlog(0, "%s:%.*s: no "
1254 "longer blocking. try to "
1255 "master this here\n",
1256 dlm->name,
1257 res->lockname.len,
1258 res->lockname.name);
1259 mle->type = DLM_MLE_MASTER;
7141514b 1260 mle->mleres = res;
e7e69eb3 1261 }
6714d8e8 1262 }
6714d8e8
KH		 1263 }
1264
e7e69eb3
KH		 1265 /* now blank out everything, as if we had never
1266 * contacted anyone */
1267 memset(mle->maybe_map, 0, sizeof(mle->maybe_map));
1268 memset(mle->response_map, 0, sizeof(mle->response_map));
1269 /* reset the vote_map to the current node_map */
1270 memcpy(mle->vote_map, mle->node_map,
1271 sizeof(mle->node_map));
1272 /* put myself into the maybe map */
1273 if (mle->type != DLM_MLE_BLOCK)
1274 set_bit(dlm->node_num, mle->maybe_map);
6714d8e8
KH		 1275 }
1276 ret = -EAGAIN;
6714d8e8
KH		 1277 node = dlm_bitmap_diff_iter_next(&bdi, &sc);
1278 }
1279 return ret;
1280}
1281
1282
1283/*
1284 * DLM_MASTER_REQUEST_MSG
1285 *
1286 * returns: 0 on success,
1287 * -errno on a network error
1288 *
1289 * on error, the caller should assume the target node is "dead"
1290 *
1291 */
1292
ba2bf218
KH		 1293static int dlm_do_master_request(struct dlm_lock_resource *res,
1294 struct dlm_master_list_entry *mle, int to)
6714d8e8
KH		 1295{
1296 struct dlm_ctxt *dlm = mle->dlm;
1297 struct dlm_master_request request;
1298 int ret, response=0, resend;
1299
1300 memset(&request, 0, sizeof(request));
1301 request.node_idx = dlm->node_num;
1302
1303 BUG_ON(mle->type == DLM_MLE_MIGRATION);
1304
7141514b
SM		 1305 request.namelen = (u8)mle->mnamelen;
1306 memcpy(request.name, mle->mname, request.namelen);
6714d8e8
KH		 1307
1308again:
1309 ret = o2net_send_message(DLM_MASTER_REQUEST_MSG, dlm->key, &request,
1310 sizeof(request), to, &response);
1311 if (ret < 0) {
1312 if (ret == -ESRCH) {
1313 /* should never happen */
1314 mlog(ML_ERROR, "TCP stack not ready!\n");
1315 BUG();
1316 } else if (ret == -EINVAL) {
1317 mlog(ML_ERROR, "bad args passed to o2net!\n");
1318 BUG();
1319 } else if (ret == -ENOMEM) {
1320 mlog(ML_ERROR, "out of memory while trying to send "
1321 "network message! retrying\n");
1322 /* this is totally crude */
1323 msleep(50);
1324 goto again;
1325 } else if (!dlm_is_host_down(ret)) {
1326 /* not a network error. bad. */
1327 mlog_errno(ret);
1328 mlog(ML_ERROR, "unhandled error!");
1329 BUG();
1330 }
1331 /* all other errors should be network errors,
1332 * and likely indicate node death */
1333 mlog(ML_ERROR, "link to %d went down!\n", to);
1334 goto out;
1335 }
1336
1337 ret = 0;
1338 resend = 0;
1339 spin_lock(&mle->spinlock);
1340 switch (response) {
1341 case DLM_MASTER_RESP_YES:
1342 set_bit(to, mle->response_map);
1343 mlog(0, "node %u is the master, response=YES\n", to);
ba2bf218
KH		 1344 mlog(0, "%s:%.*s: master node %u now knows I have a "
1345 "reference\n", dlm->name, res->lockname.len,
1346 res->lockname.name, to);
6714d8e8
KH		 1347 mle->master = to;
1348 break;
1349 case DLM_MASTER_RESP_NO:
1350 mlog(0, "node %u not master, response=NO\n", to);
1351 set_bit(to, mle->response_map);
1352 break;
1353 case DLM_MASTER_RESP_MAYBE:
1354 mlog(0, "node %u not master, response=MAYBE\n", to);
1355 set_bit(to, mle->response_map);
1356 set_bit(to, mle->maybe_map);
1357 break;
1358 case DLM_MASTER_RESP_ERROR:
1359 mlog(0, "node %u hit an error, resending\n", to);
1360 resend = 1;
1361 response = 0;
1362 break;
1363 default:
1364 mlog(ML_ERROR, "bad response! %u\n", response);
1365 BUG();
1366 }
1367 spin_unlock(&mle->spinlock);
1368 if (resend) {
1369 /* this is also totally crude */
1370 msleep(50);
1371 goto again;
1372 }
1373
1374out:
1375 return ret;
1376}
1377
1378/*
1379 * locks that can be taken here:
1380 * dlm->spinlock
1381 * res->spinlock
1382 * mle->spinlock
1383 * dlm->master_list
1384 *
1385 * if possible, TRIM THIS DOWN!!!
1386 */
d74c9803
KH		 1387int dlm_master_request_handler(struct o2net_msg *msg, u32 len, void *data,
1388 void **ret_data)
6714d8e8
KH		 1389{
1390 u8 response = DLM_MASTER_RESP_MAYBE;
1391 struct dlm_ctxt *dlm = data;
9c6510a5 1392 struct dlm_lock_resource *res = NULL;
6714d8e8
KH		 1393 struct dlm_master_request *request = (struct dlm_master_request *) msg->buf;
1394 struct dlm_master_list_entry *mle = NULL, *tmpmle = NULL;
1395 char *name;
a3d33291 1396 unsigned int namelen, hash;
6714d8e8
KH		 1397 int found, ret;
1398 int set_maybe;
9c6510a5 1399 int dispatch_assert = 0;
6714d8e8
KH		 1400
1401 if (!dlm_grab(dlm))
1402 return DLM_MASTER_RESP_NO;
1403
1404 if (!dlm_domain_fully_joined(dlm)) {
1405 response = DLM_MASTER_RESP_NO;
1406 goto send_response;
1407 }
1408
1409 name = request->name;
1410 namelen = request->namelen;
a3d33291 1411 hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 1412
1413 if (namelen > DLM_LOCKID_NAME_MAX) {
1414 response = DLM_IVBUFLEN;
1415 goto send_response;
1416 }
1417
1418way_up_top:
1419 spin_lock(&dlm->spinlock);
a3d33291 1420 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
6714d8e8
KH		 1421 if (res) {
1422 spin_unlock(&dlm->spinlock);
1423
1424 /* take care of the easy cases up front */
1425 spin_lock(&res->spinlock);
1cd04dbe
KH		 1426 if (res->state & (DLM_LOCK_RES_RECOVERING|
1427 DLM_LOCK_RES_MIGRATING)) {
6714d8e8
KH		 1428 spin_unlock(&res->spinlock);
1429 mlog(0, "returning DLM_MASTER_RESP_ERROR since res is "
1cd04dbe 1430 "being recovered/migrated\n");
6714d8e8
KH		 1431 response = DLM_MASTER_RESP_ERROR;
1432 if (mle)
1433 kmem_cache_free(dlm_mle_cache, mle);
1434 goto send_response;
1435 }
1436
1437 if (res->owner == dlm->node_num) {
8d400b81 1438 dlm_lockres_set_refmap_bit(dlm, res, request->node_idx);
6714d8e8 1439 spin_unlock(&res->spinlock);
6714d8e8
KH		 1440 response = DLM_MASTER_RESP_YES;
1441 if (mle)
1442 kmem_cache_free(dlm_mle_cache, mle);
1443
1444 /* this node is the owner.
1445 * there is some extra work that needs to
1446 * happen now. the requesting node has
1447 * caused all nodes up to this one to
1448 * create mles. this node now needs to
1449 * go back and clean those up. */
9c6510a5 1450 dispatch_assert = 1;
6714d8e8
KH		 1451 goto send_response;
1452 } else if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
1453 spin_unlock(&res->spinlock);
1454 // mlog(0, "node %u is the master\n", res->owner);
1455 response = DLM_MASTER_RESP_NO;
1456 if (mle)
1457 kmem_cache_free(dlm_mle_cache, mle);
1458 goto send_response;
1459 }
1460
1461 /* ok, there is no owner. either this node is
1462 * being blocked, or it is actively trying to
1463 * master this lock. */
1464 if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) {
1465 mlog(ML_ERROR, "lock with no owner should be "
1466 "in-progress!\n");
1467 BUG();
1468 }
1469
1470 // mlog(0, "lockres is in progress...\n");
1471 spin_lock(&dlm->master_lock);
1472 found = dlm_find_mle(dlm, &tmpmle, name, namelen);
1473 if (!found) {
1474 mlog(ML_ERROR, "no mle found for this lock!\n");
1475 BUG();
1476 }
1477 set_maybe = 1;
1478 spin_lock(&tmpmle->spinlock);
1479 if (tmpmle->type == DLM_MLE_BLOCK) {
1480 // mlog(0, "this node is waiting for "
1481 // "lockres to be mastered\n");
1482 response = DLM_MASTER_RESP_NO;
1483 } else if (tmpmle->type == DLM_MLE_MIGRATION) {
1484 mlog(0, "node %u is master, but trying to migrate to "
1485 "node %u.\n", tmpmle->master, tmpmle->new_master);
1486 if (tmpmle->master == dlm->node_num) {
6714d8e8
KH		 1487 mlog(ML_ERROR, "no owner on lockres, but this "
1488 "node is trying to migrate it to %u?!\n",
1489 tmpmle->new_master);
1490 BUG();
1491 } else {
1492 /* the real master can respond on its own */
1493 response = DLM_MASTER_RESP_NO;
1494 }
1495 } else if (tmpmle->master != DLM_LOCK_RES_OWNER_UNKNOWN) {
1496 set_maybe = 0;
9c6510a5 1497 if (tmpmle->master == dlm->node_num) {
6714d8e8 1498 response = DLM_MASTER_RESP_YES;
9c6510a5
KH		 1499 /* this node will be the owner.
1500 * go back and clean the mles on any
1501 * other nodes */
1502 dispatch_assert = 1;
8d400b81
SM		 1503 dlm_lockres_set_refmap_bit(dlm, res,
1504 request->node_idx);
9c6510a5 1505 } else
6714d8e8
KH		 1506 response = DLM_MASTER_RESP_NO;
1507 } else {
1508 // mlog(0, "this node is attempting to "
1509 // "master lockres\n");
1510 response = DLM_MASTER_RESP_MAYBE;
1511 }
1512 if (set_maybe)
1513 set_bit(request->node_idx, tmpmle->maybe_map);
1514 spin_unlock(&tmpmle->spinlock);
1515
1516 spin_unlock(&dlm->master_lock);
1517 spin_unlock(&res->spinlock);
1518
1519 /* keep the mle attached to heartbeat events */
1520 dlm_put_mle(tmpmle);
1521 if (mle)
1522 kmem_cache_free(dlm_mle_cache, mle);
1523 goto send_response;
1524 }
1525
1526 /*
1527 * lockres doesn't exist on this node
1528 * if there is an MLE_BLOCK, return NO
1529 * if there is an MLE_MASTER, return MAYBE
1530 * otherwise, add an MLE_BLOCK, return NO
1531 */
1532 spin_lock(&dlm->master_lock);
1533 found = dlm_find_mle(dlm, &tmpmle, name, namelen);
1534 if (!found) {
1535 /* this lockid has never been seen on this node yet */
1536 // mlog(0, "no mle found\n");
1537 if (!mle) {
1538 spin_unlock(&dlm->master_lock);
1539 spin_unlock(&dlm->spinlock);
1540
3914ed0c 1541 mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
6714d8e8 1542 if (!mle) {
6714d8e8 1543 response = DLM_MASTER_RESP_ERROR;
9c6510a5 1544 mlog_errno(-ENOMEM);
6714d8e8
KH		 1545 goto send_response;
1546 }
6714d8e8
KH		 1547 goto way_up_top;
1548 }
1549
1550 // mlog(0, "this is second time thru, already allocated, "
1551 // "add the block.\n");
41b8c8a1 1552 dlm_init_mle(mle, DLM_MLE_BLOCK, dlm, NULL, name, namelen);
6714d8e8 1553 set_bit(request->node_idx, mle->maybe_map);
1c084577 1554 __dlm_insert_mle(dlm, mle);
6714d8e8
KH		 1555 response = DLM_MASTER_RESP_NO;
1556 } else {
1557 // mlog(0, "mle was found\n");
1558 set_maybe = 1;
1559 spin_lock(&tmpmle->spinlock);
9c6510a5
KH		 1560 if (tmpmle->master == dlm->node_num) {
1561 mlog(ML_ERROR, "no lockres, but an mle with this node as master!\n");
1562 BUG();
1563 }
6714d8e8
KH		 1564 if (tmpmle->type == DLM_MLE_BLOCK)
1565 response = DLM_MASTER_RESP_NO;
1566 else if (tmpmle->type == DLM_MLE_MIGRATION) {
1567 mlog(0, "migration mle was found (%u->%u)\n",
1568 tmpmle->master, tmpmle->new_master);
6714d8e8
KH		 1569 /* real master can respond on its own */
1570 response = DLM_MASTER_RESP_NO;
9c6510a5
KH		 1571 } else
1572 response = DLM_MASTER_RESP_MAYBE;
6714d8e8
KH		 1573 if (set_maybe)
1574 set_bit(request->node_idx, tmpmle->maybe_map);
1575 spin_unlock(&tmpmle->spinlock);
1576 }
1577 spin_unlock(&dlm->master_lock);
1578 spin_unlock(&dlm->spinlock);
1579
1580 if (found) {
1581 /* keep the mle attached to heartbeat events */
1582 dlm_put_mle(tmpmle);
1583 }
1584send_response:
b31cfc02
SM		 1585 /*
1586 * __dlm_lookup_lockres() grabbed a reference to this lockres.
1587 * The reference is released by dlm_assert_master_worker() under
1588 * the call to dlm_dispatch_assert_master(). If
1589 * dlm_assert_master_worker() isn't called, we drop it here.
1590 */
9c6510a5
KH		 1591 if (dispatch_assert) {
1592 if (response != DLM_MASTER_RESP_YES)
1593 mlog(ML_ERROR, "invalid response %d\n", response);
1594 if (!res) {
1595 mlog(ML_ERROR, "bad lockres while trying to assert!\n");
1596 BUG();
1597 }
1598 mlog(0, "%u is the owner of %.*s, cleaning everyone else\n",
1599 dlm->node_num, res->lockname.len, res->lockname.name);
2bd63216 1600 ret = dlm_dispatch_assert_master(dlm, res, 0, request->node_idx,
9c6510a5
KH		 1601 DLM_ASSERT_MASTER_MLE_CLEANUP);
1602 if (ret < 0) {
1603 mlog(ML_ERROR, "failed to dispatch assert master work\n");
1604 response = DLM_MASTER_RESP_ERROR;
b31cfc02 1605 dlm_lockres_put(res);
9c6510a5 1606 }
b31cfc02
SM		 1607 } else {
1608 if (res)
1609 dlm_lockres_put(res);
9c6510a5
KH		 1610 }
1611
6714d8e8
KH		 1612 dlm_put(dlm);
1613 return response;
1614}
1615
1616/*
1617 * DLM_ASSERT_MASTER_MSG
1618 */
1619
1620
1621/*
1622 * NOTE: this can be used for debugging
1623 * can periodically run all locks owned by this node
1624 * and re-assert across the cluster...
1625 */
05488bbe
AB		 1626static int dlm_do_assert_master(struct dlm_ctxt *dlm,
1627 struct dlm_lock_resource *res,
1628 void *nodemap, u32 flags)
6714d8e8
KH		 1629{
1630 struct dlm_assert_master assert;
1631 int to, tmpret;
1632 struct dlm_node_iter iter;
1633 int ret = 0;
9c6510a5 1634 int reassert;
ba2bf218
KH		 1635 const char *lockname = res->lockname.name;
1636 unsigned int namelen = res->lockname.len;
6714d8e8
KH		 1637
1638 BUG_ON(namelen > O2NM_MAX_NAME_LEN);
f3f85464
SM		 1639
1640 spin_lock(&res->spinlock);
1641 res->state |= DLM_LOCK_RES_SETREF_INPROG;
1642 spin_unlock(&res->spinlock);
1643
9c6510a5
KH		 1644again:
1645 reassert = 0;
6714d8e8
KH		 1646
1647 /* note that if this nodemap is empty, it returns 0 */
1648 dlm_node_iter_init(nodemap, &iter);
1649 while ((to = dlm_node_iter_next(&iter)) >= 0) {
1650 int r = 0;
a9ee4c8a
KH		 1651 struct dlm_master_list_entry *mle = NULL;
1652
6714d8e8
KH		 1653 mlog(0, "sending assert master to %d (%.*s)\n", to,
1654 namelen, lockname);
1655 memset(&assert, 0, sizeof(assert));
1656 assert.node_idx = dlm->node_num;
1657 assert.namelen = namelen;
1658 memcpy(assert.name, lockname, namelen);
1659 assert.flags = cpu_to_be32(flags);
1660
1661 tmpret = o2net_send_message(DLM_ASSERT_MASTER_MSG, dlm->key,
1662 &assert, sizeof(assert), to, &r);
1663 if (tmpret < 0) {
a5196ec5
WW		 1664 mlog(ML_ERROR, "Error %d when sending message %u (key "
1665 "0x%x) to node %u\n", tmpret,
1666 DLM_ASSERT_MASTER_MSG, dlm->key, to);
6714d8e8 1667 if (!dlm_is_host_down(tmpret)) {
3b3b84a8 1668 mlog(ML_ERROR, "unhandled error=%d!\n", tmpret);
6714d8e8
KH		 1669 BUG();
1670 }
1671 /* a node died. finish out the rest of the nodes. */
3b3b84a8 1672 mlog(0, "link to %d went down!\n", to);
6714d8e8
KH		 1673 /* any nonzero status return will do */
1674 ret = tmpret;
ba2bf218 1675 r = 0;
6714d8e8
KH		 1676 } else if (r < 0) {
1677 /* ok, something horribly messed. kill thyself. */
1678 mlog(ML_ERROR,"during assert master of %.*s to %u, "
1679 "got %d.\n", namelen, lockname, to, r);
a9ee4c8a
KH		 1680 spin_lock(&dlm->spinlock);
1681 spin_lock(&dlm->master_lock);
1682 if (dlm_find_mle(dlm, &mle, (char *)lockname,
1683 namelen)) {
1684 dlm_print_one_mle(mle);
1685 __dlm_put_mle(mle);
1686 }
1687 spin_unlock(&dlm->master_lock);
1688 spin_unlock(&dlm->spinlock);
6714d8e8 1689 BUG();
ba2bf218
KH		 1690 }
1691
1692 if (r & DLM_ASSERT_RESPONSE_REASSERT &&
1693 !(r & DLM_ASSERT_RESPONSE_MASTERY_REF)) {
1694 mlog(ML_ERROR, "%.*s: very strange, "
1695 "master MLE but no lockres on %u\n",
1696 namelen, lockname, to);
1697 }
1698
1699 if (r & DLM_ASSERT_RESPONSE_REASSERT) {
9c6510a5 1700 mlog(0, "%.*s: node %u create mles on other "
2bd63216 1701 "nodes and requests a re-assert\n",
9c6510a5
KH		 1702 namelen, lockname, to);
1703 reassert = 1;
6714d8e8 1704 }
ba2bf218
KH		 1705 if (r & DLM_ASSERT_RESPONSE_MASTERY_REF) {
1706 mlog(0, "%.*s: node %u has a reference to this "
1707 "lockres, set the bit in the refmap\n",
1708 namelen, lockname, to);
1709 spin_lock(&res->spinlock);
8d400b81 1710 dlm_lockres_set_refmap_bit(dlm, res, to);
ba2bf218
KH		 1711 spin_unlock(&res->spinlock);
1712 }
6714d8e8
KH		 1713 }
1714
9c6510a5
KH		 1715 if (reassert)
1716 goto again;
1717
f3f85464
SM		 1718 spin_lock(&res->spinlock);
1719 res->state &= ~DLM_LOCK_RES_SETREF_INPROG;
1720 spin_unlock(&res->spinlock);
1721 wake_up(&res->wq);
1722
6714d8e8
KH		 1723 return ret;
1724}
1725
1726/*
1727 * locks that can be taken here:
1728 * dlm->spinlock
1729 * res->spinlock
1730 * mle->spinlock
1731 * dlm->master_list
1732 *
1733 * if possible, TRIM THIS DOWN!!!
1734 */
d74c9803
KH		 1735int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data,
1736 void **ret_data)
6714d8e8
KH		 1737{
1738 struct dlm_ctxt *dlm = data;
1739 struct dlm_master_list_entry *mle = NULL;
1740 struct dlm_assert_master *assert = (struct dlm_assert_master *)msg->buf;
1741 struct dlm_lock_resource *res = NULL;
1742 char *name;
a3d33291 1743 unsigned int namelen, hash;
6714d8e8 1744 u32 flags;
ba2bf218 1745 int master_request = 0, have_lockres_ref = 0;
9c6510a5 1746 int ret = 0;
6714d8e8
KH		 1747
1748 if (!dlm_grab(dlm))
1749 return 0;
1750
1751 name = assert->name;
1752 namelen = assert->namelen;
a3d33291 1753 hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 1754 flags = be32_to_cpu(assert->flags);
1755
1756 if (namelen > DLM_LOCKID_NAME_MAX) {
1757 mlog(ML_ERROR, "Invalid name length!");
1758 goto done;
1759 }
1760
1761 spin_lock(&dlm->spinlock);
1762
1763 if (flags)
1764 mlog(0, "assert_master with flags: %u\n", flags);
1765
1766 /* find the MLE */
1767 spin_lock(&dlm->master_lock);
1768 if (!dlm_find_mle(dlm, &mle, name, namelen)) {
1769 /* not an error, could be master just re-asserting */
1770 mlog(0, "just got an assert_master from %u, but no "
1771 "MLE for it! (%.*s)\n", assert->node_idx,
1772 namelen, name);
1773 } else {
1774 int bit = find_next_bit (mle->maybe_map, O2NM_MAX_NODES, 0);
1775 if (bit >= O2NM_MAX_NODES) {
1776 /* not necessarily an error, though less likely.
1777 * could be master just re-asserting. */
aa852354 1778 mlog(0, "no bits set in the maybe_map, but %u "
6714d8e8
KH		 1779 "is asserting! (%.*s)\n", assert->node_idx,
1780 namelen, name);
1781 } else if (bit != assert->node_idx) {
1782 if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) {
1783 mlog(0, "master %u was found, %u should "
1784 "back off\n", assert->node_idx, bit);
1785 } else {
1786 /* with the fix for bug 569, a higher node
1787 * number winning the mastery will respond
1788 * YES to mastery requests, but this node
1789 * had no way of knowing. let it pass. */
aa852354 1790 mlog(0, "%u is the lowest node, "
6714d8e8
KH		 1791 "%u is asserting. (%.*s) %u must "
1792 "have begun after %u won.\n", bit,
1793 assert->node_idx, namelen, name, bit,
1794 assert->node_idx);
1795 }
1796 }
2d1a868c
KH		 1797 if (mle->type == DLM_MLE_MIGRATION) {
1798 if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) {
1799 mlog(0, "%s:%.*s: got cleanup assert"
1800 " from %u for migration\n",
1801 dlm->name, namelen, name,
1802 assert->node_idx);
1803 } else if (!(flags & DLM_ASSERT_MASTER_FINISH_MIGRATION)) {
1804 mlog(0, "%s:%.*s: got unrelated assert"
1805 " from %u for migration, ignoring\n",
1806 dlm->name, namelen, name,
1807 assert->node_idx);
1808 __dlm_put_mle(mle);
1809 spin_unlock(&dlm->master_lock);
1810 spin_unlock(&dlm->spinlock);
1811 goto done;
2bd63216 1812 }
2d1a868c 1813 }
6714d8e8
KH		 1814 }
1815 spin_unlock(&dlm->master_lock);
1816
1817 /* ok everything checks out with the MLE
1818 * now check to see if there is a lockres */
a3d33291 1819 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
6714d8e8
KH		 1820 if (res) {
1821 spin_lock(&res->spinlock);
1822 if (res->state & DLM_LOCK_RES_RECOVERING) {
1823 mlog(ML_ERROR, "%u asserting but %.*s is "
1824 "RECOVERING!\n", assert->node_idx, namelen, name);
1825 goto kill;
1826 }
1827 if (!mle) {
dc2ed195
KH		 1828 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN &&
1829 res->owner != assert->node_idx) {
53ecd25e
SM		 1830 mlog(ML_ERROR, "DIE! Mastery assert from %u, "
1831 "but current owner is %u! (%.*s)\n",
1832 assert->node_idx, res->owner, namelen,
1833 name);
1834 __dlm_print_one_lock_resource(res);
1835 BUG();
6714d8e8
KH		 1836 }
1837 } else if (mle->type != DLM_MLE_MIGRATION) {
1838 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
1839 /* owner is just re-asserting */
1840 if (res->owner == assert->node_idx) {
1841 mlog(0, "owner %u re-asserting on "
1842 "lock %.*s\n", assert->node_idx,
1843 namelen, name);
1844 goto ok;
1845 }
1846 mlog(ML_ERROR, "got assert_master from "
1847 "node %u, but %u is the owner! "
1848 "(%.*s)\n", assert->node_idx,
1849 res->owner, namelen, name);
1850 goto kill;
1851 }
1852 if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) {
1853 mlog(ML_ERROR, "got assert from %u, but lock "
1854 "with no owner should be "
1855 "in-progress! (%.*s)\n",
1856 assert->node_idx,
1857 namelen, name);
1858 goto kill;
1859 }
1860 } else /* mle->type == DLM_MLE_MIGRATION */ {
1861 /* should only be getting an assert from new master */
1862 if (assert->node_idx != mle->new_master) {
1863 mlog(ML_ERROR, "got assert from %u, but "
1864 "new master is %u, and old master "
1865 "was %u (%.*s)\n",
1866 assert->node_idx, mle->new_master,
1867 mle->master, namelen, name);
1868 goto kill;
1869 }
1870
1871 }
1872ok:
1873 spin_unlock(&res->spinlock);
1874 }
6714d8e8
KH		 1875
1876 // mlog(0, "woo! got an assert_master from node %u!\n",
1877 // assert->node_idx);
1878 if (mle) {
9c6510a5
KH		 1879 int extra_ref = 0;
1880 int nn = -1;
a2bf0477 1881 int rr, err = 0;
2bd63216 1882
6714d8e8 1883 spin_lock(&mle->spinlock);
9c6510a5
KH		 1884 if (mle->type == DLM_MLE_BLOCK || mle->type == DLM_MLE_MIGRATION)
1885 extra_ref = 1;
1886 else {
1887 /* MASTER mle: if any bits set in the response map
1888 * then the calling node needs to re-assert to clear
1889 * up nodes that this node contacted */
2bd63216 1890 while ((nn = find_next_bit (mle->response_map, O2NM_MAX_NODES,
9c6510a5 1891 nn+1)) < O2NM_MAX_NODES) {
728b9805 1892 if (nn != dlm->node_num && nn != assert->node_idx) {
9c6510a5 1893 master_request = 1;
728b9805
JB		 1894 break;
1895 }
9c6510a5
KH		 1896 }
1897 }
6714d8e8
KH		 1898 mle->master = assert->node_idx;
1899 atomic_set(&mle->woken, 1);
1900 wake_up(&mle->wq);
1901 spin_unlock(&mle->spinlock);
1902
a2bf0477 1903 if (res) {
a6fa3640 1904 int wake = 0;
6714d8e8 1905 spin_lock(&res->spinlock);
a2bf0477
KH		 1906 if (mle->type == DLM_MLE_MIGRATION) {
1907 mlog(0, "finishing off migration of lockres %.*s, "
1908 "from %u to %u\n",
1909 res->lockname.len, res->lockname.name,
1910 dlm->node_num, mle->new_master);
1911 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 1912 wake = 1;
a2bf0477
KH		 1913 dlm_change_lockres_owner(dlm, res, mle->new_master);
1914 BUG_ON(res->state & DLM_LOCK_RES_DIRTY);
1915 } else {
1916 dlm_change_lockres_owner(dlm, res, mle->master);
1917 }
6714d8e8 1918 spin_unlock(&res->spinlock);
ba2bf218 1919 have_lockres_ref = 1;
a6fa3640
KH		 1920 if (wake)
1921 wake_up(&res->wq);
6714d8e8 1922 }
a2bf0477
KH		 1923
1924 /* master is known, detach if not already detached.
1925 * ensures that only one assert_master call will happen
1926 * on this mle. */
a2bf0477
KH		 1927 spin_lock(&dlm->master_lock);
1928
1929 rr = atomic_read(&mle->mle_refs.refcount);
1930 if (mle->inuse > 0) {
1931 if (extra_ref && rr < 3)
1932 err = 1;
1933 else if (!extra_ref && rr < 2)
1934 err = 1;
1935 } else {
1936 if (extra_ref && rr < 2)
1937 err = 1;
1938 else if (!extra_ref && rr < 1)
1939 err = 1;
1940 }
1941 if (err) {
1942 mlog(ML_ERROR, "%s:%.*s: got assert master from %u "
1943 "that will mess up this node, refs=%d, extra=%d, "
1944 "inuse=%d\n", dlm->name, namelen, name,
1945 assert->node_idx, rr, extra_ref, mle->inuse);
1946 dlm_print_one_mle(mle);
1947 }
1c084577 1948 __dlm_unlink_mle(dlm, mle);
a2bf0477
KH		 1949 __dlm_mle_detach_hb_events(dlm, mle);
1950 __dlm_put_mle(mle);
6714d8e8
KH		 1951 if (extra_ref) {
1952 /* the assert master message now balances the extra
1953 * ref given by the master / migration request message.
1954 * if this is the last put, it will be removed
1955 * from the list. */
a2bf0477
KH		 1956 __dlm_put_mle(mle);
1957 }
1958 spin_unlock(&dlm->master_lock);
a2bf0477
KH		 1959 } else if (res) {
1960 if (res->owner != assert->node_idx) {
1961 mlog(0, "assert_master from %u, but current "
1962 "owner is %u (%.*s), no mle\n", assert->node_idx,
1963 res->owner, namelen, name);
6714d8e8
KH		 1964 }
1965 }
14741472 1966 spin_unlock(&dlm->spinlock);
6714d8e8
KH		 1967
1968done:
9c6510a5 1969 ret = 0;
3b8118cf
KH		 1970 if (res) {
1971 spin_lock(&res->spinlock);
1972 res->state |= DLM_LOCK_RES_SETREF_INPROG;
1973 spin_unlock(&res->spinlock);
1974 *ret_data = (void *)res;
1975 }
6714d8e8 1976 dlm_put(dlm);
9c6510a5
KH		 1977 if (master_request) {
1978 mlog(0, "need to tell master to reassert\n");
ba2bf218
KH		 1979 /* positive. negative would shoot down the node. */
1980 ret |= DLM_ASSERT_RESPONSE_REASSERT;
1981 if (!have_lockres_ref) {
1982 mlog(ML_ERROR, "strange, got assert from %u, MASTER "
1983 "mle present here for %s:%.*s, but no lockres!\n",
1984 assert->node_idx, dlm->name, namelen, name);
1985 }
1986 }
1987 if (have_lockres_ref) {
1988 /* let the master know we have a reference to the lockres */
1989 ret |= DLM_ASSERT_RESPONSE_MASTERY_REF;
1990 mlog(0, "%s:%.*s: got assert from %u, need a ref\n",
1991 dlm->name, namelen, name, assert->node_idx);
9c6510a5
KH		 1992 }
1993 return ret;
6714d8e8
KH		 1994
1995kill:
1996 /* kill the caller! */
a9ee4c8a
KH		 1997 mlog(ML_ERROR, "Bad message received from another node. Dumping state "
1998 "and killing the other node now! This node is OK and can continue.\n");
1999 __dlm_print_one_lock_resource(res);
6714d8e8
KH		 2000 spin_unlock(&res->spinlock);
2001 spin_unlock(&dlm->spinlock);
2bd63216 2002 *ret_data = (void *)res;
6714d8e8
KH		 2003 dlm_put(dlm);
2004 return -EINVAL;
2005}
2006
3b8118cf
KH		 2007void dlm_assert_master_post_handler(int status, void *data, void *ret_data)
2008{
2009 struct dlm_lock_resource *res = (struct dlm_lock_resource *)ret_data;
2010
2011 if (ret_data) {
2012 spin_lock(&res->spinlock);
2013 res->state &= ~DLM_LOCK_RES_SETREF_INPROG;
2014 spin_unlock(&res->spinlock);
2015 wake_up(&res->wq);
2016 dlm_lockres_put(res);
2017 }
2018 return;
2019}
2020
6714d8e8
KH		 2021int dlm_dispatch_assert_master(struct dlm_ctxt *dlm,
2022 struct dlm_lock_resource *res,
2023 int ignore_higher, u8 request_from, u32 flags)
2024{
2025 struct dlm_work_item *item;
b24ae0b5 2026 item = kzalloc(sizeof(*item), GFP_ATOMIC);
6714d8e8
KH		 2027 if (!item)
2028 return -ENOMEM;
2029
2030
2031 /* queue up work for dlm_assert_master_worker */
2032 dlm_grab(dlm); /* get an extra ref for the work item */
2033 dlm_init_work_item(dlm, item, dlm_assert_master_worker, NULL);
2034 item->u.am.lockres = res; /* already have a ref */
2035 /* can optionally ignore node numbers higher than this node */
2036 item->u.am.ignore_higher = ignore_higher;
2037 item->u.am.request_from = request_from;
2038 item->u.am.flags = flags;
2039
2bd63216
SM		 2040 if (ignore_higher)
2041 mlog(0, "IGNORE HIGHER: %.*s\n", res->lockname.len,
9c6510a5 2042 res->lockname.name);
2bd63216 2043
6714d8e8
KH		 2044 spin_lock(&dlm->work_lock);
2045 list_add_tail(&item->list, &dlm->work_list);
2046 spin_unlock(&dlm->work_lock);
2047
3156d267 2048 queue_work(dlm->dlm_worker, &dlm->dispatched_work);
6714d8e8
KH		 2049 return 0;
2050}
2051
2052static void dlm_assert_master_worker(struct dlm_work_item *item, void *data)
2053{
2054 struct dlm_ctxt *dlm = data;
2055 int ret = 0;
2056 struct dlm_lock_resource *res;
2057 unsigned long nodemap[BITS_TO_LONGS(O2NM_MAX_NODES)];
2058 int ignore_higher;
2059 int bit;
2060 u8 request_from;
2061 u32 flags;
2062
2063 dlm = item->dlm;
2064 res = item->u.am.lockres;
2065 ignore_higher = item->u.am.ignore_higher;
2066 request_from = item->u.am.request_from;
2067 flags = item->u.am.flags;
2068
2069 spin_lock(&dlm->spinlock);
2070 memcpy(nodemap, dlm->domain_map, sizeof(nodemap));
2071 spin_unlock(&dlm->spinlock);
2072
2073 clear_bit(dlm->node_num, nodemap);
2074 if (ignore_higher) {
2075 /* if is this just to clear up mles for nodes below
2076 * this node, do not send the message to the original
2077 * caller or any node number higher than this */
2078 clear_bit(request_from, nodemap);
2079 bit = dlm->node_num;
2080 while (1) {
2081 bit = find_next_bit(nodemap, O2NM_MAX_NODES,
2082 bit+1);
2083 if (bit >= O2NM_MAX_NODES)
2084 break;
2085 clear_bit(bit, nodemap);
2086 }
2087 }
2088
36407488
KH		 2089 /*
2090 * If we're migrating this lock to someone else, we are no
2091 * longer allowed to assert out own mastery. OTOH, we need to
2092 * prevent migration from starting while we're still asserting
2093 * our dominance. The reserved ast delays migration.
2094 */
2095 spin_lock(&res->spinlock);
2096 if (res->state & DLM_LOCK_RES_MIGRATING) {
2097 mlog(0, "Someone asked us to assert mastery, but we're "
2098 "in the middle of migration. Skipping assert, "
2099 "the new master will handle that.\n");
2100 spin_unlock(&res->spinlock);
2101 goto put;
2102 } else
2103 __dlm_lockres_reserve_ast(res);
2104 spin_unlock(&res->spinlock);
2105
6714d8e8
KH		 2106 /* this call now finishes out the nodemap
2107 * even if one or more nodes die */
2108 mlog(0, "worker about to master %.*s here, this=%u\n",
2109 res->lockname.len, res->lockname.name, dlm->node_num);
ba2bf218 2110 ret = dlm_do_assert_master(dlm, res, nodemap, flags);
6714d8e8
KH		 2111 if (ret < 0) {
2112 /* no need to restart, we are done */
3b3b84a8
KH		 2113 if (!dlm_is_host_down(ret))
2114 mlog_errno(ret);
6714d8e8
KH		 2115 }
2116
36407488
KH		 2117 /* Ok, we've asserted ourselves. Let's let migration start. */
2118 dlm_lockres_release_ast(dlm, res);
2119
2120put:
6714d8e8
KH		 2121 dlm_lockres_put(res);
2122
2123 mlog(0, "finished with dlm_assert_master_worker\n");
2124}
2125
c03872f5
KH		 2126/* SPECIAL CASE for the $RECOVERY lock used by the recovery thread.
2127 * We cannot wait for node recovery to complete to begin mastering this
2128 * lockres because this lockres is used to kick off recovery! ;-)
2129 * So, do a pre-check on all living nodes to see if any of those nodes
2130 * think that $RECOVERY is currently mastered by a dead node. If so,
2131 * we wait a short time to allow that node to get notified by its own
2132 * heartbeat stack, then check again. All $RECOVERY lock resources
2bd63216 2133 * mastered by dead nodes are purged when the hearbeat callback is
c03872f5
KH		 2134 * fired, so we can know for sure that it is safe to continue once
2135 * the node returns a live node or no node. */
2136static int dlm_pre_master_reco_lockres(struct dlm_ctxt *dlm,
2137 struct dlm_lock_resource *res)
2138{
2139 struct dlm_node_iter iter;
2140 int nodenum;
2141 int ret = 0;
2142 u8 master = DLM_LOCK_RES_OWNER_UNKNOWN;
2143
2144 spin_lock(&dlm->spinlock);
2145 dlm_node_iter_init(dlm->domain_map, &iter);
2146 spin_unlock(&dlm->spinlock);
2147
2148 while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2149 /* do not send to self */
2150 if (nodenum == dlm->node_num)
2151 continue;
2152 ret = dlm_do_master_requery(dlm, res, nodenum, &master);
2153 if (ret < 0) {
2154 mlog_errno(ret);
2155 if (!dlm_is_host_down(ret))
2156 BUG();
2157 /* host is down, so answer for that node would be
2158 * DLM_LOCK_RES_OWNER_UNKNOWN. continue. */
f42a100b 2159 ret = 0;
c03872f5
KH		 2160 }
2161
2162 if (master != DLM_LOCK_RES_OWNER_UNKNOWN) {
2163 /* check to see if this master is in the recovery map */
2164 spin_lock(&dlm->spinlock);
2165 if (test_bit(master, dlm->recovery_map)) {
2166 mlog(ML_NOTICE, "%s: node %u has not seen "
2167 "node %u go down yet, and thinks the "
2168 "dead node is mastering the recovery "
2169 "lock. must wait.\n", dlm->name,
2170 nodenum, master);
2171 ret = -EAGAIN;
2172 }
2173 spin_unlock(&dlm->spinlock);
2bd63216 2174 mlog(0, "%s: reco lock master is %u\n", dlm->name,
c03872f5
KH		 2175 master);
2176 break;
2177 }
2178 }
2179 return ret;
2180}
2181
ba2bf218
KH		 2182/*
2183 * DLM_DEREF_LOCKRES_MSG
2184 */
2185
2186int dlm_drop_lockres_ref(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
2187{
2188 struct dlm_deref_lockres deref;
2189 int ret = 0, r;
2190 const char *lockname;
2191 unsigned int namelen;
2192
2193 lockname = res->lockname.name;
2194 namelen = res->lockname.len;
2195 BUG_ON(namelen > O2NM_MAX_NAME_LEN);
2196
ba2bf218
KH		 2197 memset(&deref, 0, sizeof(deref));
2198 deref.node_idx = dlm->node_num;
2199 deref.namelen = namelen;
2200 memcpy(deref.name, lockname, namelen);
2201
2202 ret = o2net_send_message(DLM_DEREF_LOCKRES_MSG, dlm->key,
2203 &deref, sizeof(deref), res->owner, &r);
2204 if (ret < 0)
8decab3c
SM		 2205 mlog(ML_ERROR, "%s: res %.*s, error %d send DEREF to node %u\n",
2206 dlm->name, namelen, lockname, ret, res->owner);
ba2bf218
KH		 2207 else if (r < 0) {
2208 /* BAD. other node says I did not have a ref. */
8decab3c
SM		 2209 mlog(ML_ERROR, "%s: res %.*s, DEREF to node %u got %d\n",
2210 dlm->name, namelen, lockname, res->owner, r);
ba2bf218
KH		 2211 dlm_print_one_lock_resource(res);
2212 BUG();
2213 }
2214 return ret;
2215}
2216
d74c9803
KH		 2217int dlm_deref_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
2218 void **ret_data)
ba2bf218
KH		 2219{
2220 struct dlm_ctxt *dlm = data;
2221 struct dlm_deref_lockres *deref = (struct dlm_deref_lockres *)msg->buf;
2222 struct dlm_lock_resource *res = NULL;
2223 char *name;
2224 unsigned int namelen;
2225 int ret = -EINVAL;
2226 u8 node;
2227 unsigned int hash;
f3f85464
SM		 2228 struct dlm_work_item *item;
2229 int cleared = 0;
2230 int dispatch = 0;
ba2bf218
KH		 2231
2232 if (!dlm_grab(dlm))
2233 return 0;
2234
2235 name = deref->name;
2236 namelen = deref->namelen;
2237 node = deref->node_idx;
2238
2239 if (namelen > DLM_LOCKID_NAME_MAX) {
2240 mlog(ML_ERROR, "Invalid name length!");
2241 goto done;
2242 }
2243 if (deref->node_idx >= O2NM_MAX_NODES) {
2244 mlog(ML_ERROR, "Invalid node number: %u\n", node);
2245 goto done;
2246 }
2247
2248 hash = dlm_lockid_hash(name, namelen);
2249
2250 spin_lock(&dlm->spinlock);
2251 res = __dlm_lookup_lockres_full(dlm, name, namelen, hash);
2252 if (!res) {
2253 spin_unlock(&dlm->spinlock);
2254 mlog(ML_ERROR, "%s:%.*s: bad lockres name\n",
2255 dlm->name, namelen, name);
2256 goto done;
2257 }
2258 spin_unlock(&dlm->spinlock);
2259
2260 spin_lock(&res->spinlock);
f3f85464
SM		 2261 if (res->state & DLM_LOCK_RES_SETREF_INPROG)
2262 dispatch = 1;
2263 else {
2264 BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF);
2265 if (test_bit(node, res->refmap)) {
8d400b81 2266 dlm_lockres_clear_refmap_bit(dlm, res, node);
f3f85464
SM		 2267 cleared = 1;
2268 }
ba2bf218
KH		 2269 }
2270 spin_unlock(&res->spinlock);
2271
f3f85464
SM		 2272 if (!dispatch) {
2273 if (cleared)
2274 dlm_lockres_calc_usage(dlm, res);
2275 else {
2276 mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref "
2277 "but it is already dropped!\n", dlm->name,
2278 res->lockname.len, res->lockname.name, node);
2af37ce8 2279 dlm_print_one_lock_resource(res);
f3f85464
SM		 2280 }
2281 ret = 0;
2282 goto done;
2283 }
2284
2285 item = kzalloc(sizeof(*item), GFP_NOFS);
2286 if (!item) {
2287 ret = -ENOMEM;
2288 mlog_errno(ret);
2289 goto done;
2290 }
2291
2292 dlm_init_work_item(dlm, item, dlm_deref_lockres_worker, NULL);
2293 item->u.dl.deref_res = res;
2294 item->u.dl.deref_node = node;
2295
2296 spin_lock(&dlm->work_lock);
2297 list_add_tail(&item->list, &dlm->work_list);
2298 spin_unlock(&dlm->work_lock);
2299
2300 queue_work(dlm->dlm_worker, &dlm->dispatched_work);
2301 return 0;
2302
ba2bf218
KH		 2303done:
2304 if (res)
2305 dlm_lockres_put(res);
2306 dlm_put(dlm);
f3f85464 2307
ba2bf218
KH		 2308 return ret;
2309}
2310
f3f85464
SM		 2311static void dlm_deref_lockres_worker(struct dlm_work_item *item, void *data)
2312{
2313 struct dlm_ctxt *dlm;
2314 struct dlm_lock_resource *res;
2315 u8 node;
2316 u8 cleared = 0;
2317
2318 dlm = item->dlm;
2319 res = item->u.dl.deref_res;
2320 node = item->u.dl.deref_node;
2321
2322 spin_lock(&res->spinlock);
2323 BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF);
2324 if (test_bit(node, res->refmap)) {
2325 __dlm_wait_on_lockres_flags(res, DLM_LOCK_RES_SETREF_INPROG);
8d400b81 2326 dlm_lockres_clear_refmap_bit(dlm, res, node);
f3f85464
SM		 2327 cleared = 1;
2328 }
2329 spin_unlock(&res->spinlock);
2330
2331 if (cleared) {
2332 mlog(0, "%s:%.*s node %u ref dropped in dispatch\n",
2333 dlm->name, res->lockname.len, res->lockname.name, node);
2334 dlm_lockres_calc_usage(dlm, res);
2335 } else {
2336 mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref "
2337 "but it is already dropped!\n", dlm->name,
2338 res->lockname.len, res->lockname.name, node);
2af37ce8 2339 dlm_print_one_lock_resource(res);
f3f85464
SM		 2340 }
2341
2342 dlm_lockres_put(res);
2343}
2344
9f62e960
SM		 2345/*
2346 * A migrateable resource is one that is :
2347 * 1. locally mastered, and,
2348 * 2. zero local locks, and,
2349 * 3. one or more non-local locks, or, one or more references
2350 * Returns 1 if yes, 0 if not.
2f5bf1f2
SM		 2351 */
2352static int dlm_is_lockres_migrateable(struct dlm_ctxt *dlm,
9f62e960 2353 struct dlm_lock_resource *res)
2f5bf1f2 2354{
9f62e960
SM		 2355 enum dlm_lockres_list idx;
2356 int nonlocal = 0, node_ref;
800deef3 2357 struct list_head *queue;
2f5bf1f2 2358 struct dlm_lock *lock;
9f62e960 2359 u64 cookie;
2f5bf1f2
SM		 2360
2361 assert_spin_locked(&res->spinlock);
2362
fae477b6
X		 2363 /* delay migration when the lockres is in MIGRATING state */
2364 if (res->state & DLM_LOCK_RES_MIGRATING)
2365 return 0;
2366
9f62e960
SM		 2367 if (res->owner != dlm->node_num)
2368 return 0;
2f5bf1f2 2369
9f62e960
SM		 2370 for (idx = DLM_GRANTED_LIST; idx <= DLM_BLOCKED_LIST; idx++) {
2371 queue = dlm_list_idx_to_ptr(res, idx);
800deef3 2372 list_for_each_entry(lock, queue, list) {
9f62e960
SM		 2373 if (lock->ml.node != dlm->node_num) {
2374 nonlocal++;
2375 continue;
2f5bf1f2 2376 }
9f62e960
SM		 2377 cookie = be64_to_cpu(lock->ml.cookie);
2378 mlog(0, "%s: Not migrateable res %.*s, lock %u:%llu on "
2379 "%s list\n", dlm->name, res->lockname.len,
2380 res->lockname.name,
2381 dlm_get_lock_cookie_node(cookie),
2382 dlm_get_lock_cookie_seq(cookie),
2383 dlm_list_in_text(idx));
2384 return 0;
2f5bf1f2 2385 }
2f5bf1f2
SM		 2386 }
2387
9f62e960
SM		 2388 if (!nonlocal) {
2389 node_ref = find_next_bit(res->refmap, O2NM_MAX_NODES, 0);
2390 if (node_ref >= O2NM_MAX_NODES)
2391 return 0;
2392 }
388c4bcb 2393
9f62e960
SM		 2394 mlog(0, "%s: res %.*s, Migrateable\n", dlm->name, res->lockname.len,
2395 res->lockname.name);
2f5bf1f2 2396
9f62e960 2397 return 1;
2f5bf1f2 2398}
6714d8e8
KH		 2399
2400/*
2401 * DLM_MIGRATE_LOCKRES
2402 */
2403
2404
faf0ec9f 2405static int dlm_migrate_lockres(struct dlm_ctxt *dlm,
66effd3c 2406 struct dlm_lock_resource *res, u8 target)
6714d8e8
KH		 2407{
2408 struct dlm_master_list_entry *mle = NULL;
2409 struct dlm_master_list_entry *oldmle = NULL;
2410 struct dlm_migratable_lockres *mres = NULL;
2f5bf1f2 2411 int ret = 0;
6714d8e8
KH		 2412 const char *name;
2413 unsigned int namelen;
2414 int mle_added = 0;
2f5bf1f2 2415 int wake = 0;
6714d8e8
KH		 2416
2417 if (!dlm_grab(dlm))
2418 return -EINVAL;
2419
66effd3c
SM		 2420 BUG_ON(target == O2NM_MAX_NODES);
2421
6714d8e8
KH		 2422 name = res->lockname.name;
2423 namelen = res->lockname.len;
2424
66effd3c
SM		 2425 mlog(0, "%s: Migrating %.*s to node %u\n", dlm->name, namelen, name,
2426 target);
6714d8e8 2427
66effd3c 2428 /* preallocate up front. if this fails, abort */
6714d8e8 2429 ret = -ENOMEM;
ad8100e0 2430 mres = (struct dlm_migratable_lockres *) __get_free_page(GFP_NOFS);
6714d8e8
KH		 2431 if (!mres) {
2432 mlog_errno(ret);
2433 goto leave;
2434 }
2435
3914ed0c 2436 mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
6714d8e8
KH		 2437 if (!mle) {
2438 mlog_errno(ret);
2439 goto leave;
2440 }
2441 ret = 0;
2442
6714d8e8
KH		 2443 /*
2444 * clear any existing master requests and
2445 * add the migration mle to the list
2446 */
66effd3c 2447 spin_lock(&dlm->spinlock);
6714d8e8
KH		 2448 spin_lock(&dlm->master_lock);
2449 ret = dlm_add_migration_mle(dlm, res, mle, &oldmle, name,
2450 namelen, target, dlm->node_num);
2451 spin_unlock(&dlm->master_lock);
2452 spin_unlock(&dlm->spinlock);
2453
2454 if (ret == -EEXIST) {
2455 mlog(0, "another process is already migrating it\n");
2456 goto fail;
2457 }
2458 mle_added = 1;
2459
2460 /*
2461 * set the MIGRATING flag and flush asts
2462 * if we fail after this we need to re-dirty the lockres
2463 */
2464 if (dlm_mark_lockres_migrating(dlm, res, target) < 0) {
2465 mlog(ML_ERROR, "tried to migrate %.*s to %u, but "
2466 "the target went down.\n", res->lockname.len,
2467 res->lockname.name, target);
2468 spin_lock(&res->spinlock);
2469 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 2470 wake = 1;
6714d8e8
KH		 2471 spin_unlock(&res->spinlock);
2472 ret = -EINVAL;
2473 }
2474
2475fail:
2476 if (oldmle) {
2477 /* master is known, detach if not already detached */
2478 dlm_mle_detach_hb_events(dlm, oldmle);
2479 dlm_put_mle(oldmle);
2480 }
2481
2482 if (ret < 0) {
2483 if (mle_added) {
2484 dlm_mle_detach_hb_events(dlm, mle);
2485 dlm_put_mle(mle);
2486 } else if (mle) {
2487 kmem_cache_free(dlm_mle_cache, mle);
66effd3c 2488 mle = NULL;
6714d8e8
KH		 2489 }
2490 goto leave;
2491 }
2492
2493 /*
2494 * at this point, we have a migration target, an mle
2495 * in the master list, and the MIGRATING flag set on
2496 * the lockres
2497 */
2498
1cd04dbe
KH		 2499 /* now that remote nodes are spinning on the MIGRATING flag,
2500 * ensure that all assert_master work is flushed. */
2501 flush_workqueue(dlm->dlm_worker);
6714d8e8
KH		 2502
2503 /* get an extra reference on the mle.
2504 * otherwise the assert_master from the new
2505 * master will destroy this.
2506 * also, make sure that all callers of dlm_get_mle
2507 * take both dlm->spinlock and dlm->master_lock */
2508 spin_lock(&dlm->spinlock);
2509 spin_lock(&dlm->master_lock);
a2bf0477 2510 dlm_get_mle_inuse(mle);
6714d8e8
KH		 2511 spin_unlock(&dlm->master_lock);
2512 spin_unlock(&dlm->spinlock);
2513
2514 /* notify new node and send all lock state */
2515 /* call send_one_lockres with migration flag.
2516 * this serves as notice to the target node that a
2517 * migration is starting. */
2518 ret = dlm_send_one_lockres(dlm, res, mres, target,
2519 DLM_MRES_MIGRATION);
2520
2521 if (ret < 0) {
2522 mlog(0, "migration to node %u failed with %d\n",
2523 target, ret);
2524 /* migration failed, detach and clean up mle */
2525 dlm_mle_detach_hb_events(dlm, mle);
2526 dlm_put_mle(mle);
a2bf0477
KH		 2527 dlm_put_mle_inuse(mle);
2528 spin_lock(&res->spinlock);
2529 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 2530 wake = 1;
a2bf0477 2531 spin_unlock(&res->spinlock);
df016c66
SM		 2532 if (dlm_is_host_down(ret))
2533 dlm_wait_for_node_death(dlm, target,
2534 DLM_NODE_DEATH_WAIT_MAX);
6714d8e8
KH		 2535 goto leave;
2536 }
2537
2538 /* at this point, the target sends a message to all nodes,
2539 * (using dlm_do_migrate_request). this node is skipped since
2540 * we had to put an mle in the list to begin the process. this
2541 * node now waits for target to do an assert master. this node
2542 * will be the last one notified, ensuring that the migration
2543 * is complete everywhere. if the target dies while this is
2544 * going on, some nodes could potentially see the target as the
2545 * master, so it is important that my recovery finds the migration
af901ca1 2546 * mle and sets the master to UNKNOWN. */
6714d8e8
KH		 2547
2548
2549 /* wait for new node to assert master */
2550 while (1) {
2551 ret = wait_event_interruptible_timeout(mle->wq,
2552 (atomic_read(&mle->woken) == 1),
2553 msecs_to_jiffies(5000));
2554
2555 if (ret >= 0) {
2556 if (atomic_read(&mle->woken) == 1 ||
2557 res->owner == target)
2558 break;
2559
1cd04dbe
KH		 2560 mlog(0, "%s:%.*s: timed out during migration\n",
2561 dlm->name, res->lockname.len, res->lockname.name);
2bd63216 2562 /* avoid hang during shutdown when migrating lockres
e2faea4c
KH		 2563 * to a node which also goes down */
2564 if (dlm_is_node_dead(dlm, target)) {
aa852354
KH		 2565 mlog(0, "%s:%.*s: expected migration "
2566 "target %u is no longer up, restarting\n",
e2faea4c
KH		 2567 dlm->name, res->lockname.len,
2568 res->lockname.name, target);
1cd04dbe
KH		 2569 ret = -EINVAL;
2570 /* migration failed, detach and clean up mle */
2571 dlm_mle_detach_hb_events(dlm, mle);
2572 dlm_put_mle(mle);
2573 dlm_put_mle_inuse(mle);
2574 spin_lock(&res->spinlock);
2575 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 2576 wake = 1;
1cd04dbe
KH		 2577 spin_unlock(&res->spinlock);
2578 goto leave;
e2faea4c 2579 }
1cd04dbe
KH		 2580 } else
2581 mlog(0, "%s:%.*s: caught signal during migration\n",
2582 dlm->name, res->lockname.len, res->lockname.name);
6714d8e8
KH		 2583 }
2584
2585 /* all done, set the owner, clear the flag */
2586 spin_lock(&res->spinlock);
2587 dlm_set_lockres_owner(dlm, res, target);
2588 res->state &= ~DLM_LOCK_RES_MIGRATING;
2589 dlm_remove_nonlocal_locks(dlm, res);
2590 spin_unlock(&res->spinlock);
2591 wake_up(&res->wq);
2592
2593 /* master is known, detach if not already detached */
2594 dlm_mle_detach_hb_events(dlm, mle);
a2bf0477 2595 dlm_put_mle_inuse(mle);
6714d8e8
KH		 2596 ret = 0;
2597
2598 dlm_lockres_calc_usage(dlm, res);
2599
2600leave:
2601 /* re-dirty the lockres if we failed */
2602 if (ret < 0)
2603 dlm_kick_thread(dlm, res);
2604
a6fa3640
KH		 2605 /* wake up waiters if the MIGRATING flag got set
2606 * but migration failed */
2607 if (wake)
2608 wake_up(&res->wq);
2609
6714d8e8
KH		 2610 if (mres)
2611 free_page((unsigned long)mres);
2612
2613 dlm_put(dlm);
2614
9f62e960
SM		 2615 mlog(0, "%s: Migrating %.*s to %u, returns %d\n", dlm->name, namelen,
2616 name, target, ret);
6714d8e8
KH		 2617 return ret;
2618}
6714d8e8 2619
ba2bf218
KH		 2620#define DLM_MIGRATION_RETRY_MS 100
2621
9f62e960
SM		 2622/*
2623 * Should be called only after beginning the domain leave process.
ba2bf218
KH		 2624 * There should not be any remaining locks on nonlocal lock resources,
2625 * and there should be no local locks left on locally mastered resources.
2626 *
2627 * Called with the dlm spinlock held, may drop it to do migration, but
2628 * will re-acquire before exit.
2629 *
9f62e960
SM		 2630 * Returns: 1 if dlm->spinlock was dropped/retaken, 0 if never dropped
2631 */
ba2bf218
KH		 2632int dlm_empty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
2633{
66effd3c 2634 int ret;
ba2bf218 2635 int lock_dropped = 0;
66effd3c 2636 u8 target = O2NM_MAX_NODES;
ba2bf218 2637
9f62e960 2638 assert_spin_locked(&dlm->spinlock);
2f5bf1f2 2639
9f62e960 2640 spin_lock(&res->spinlock);
66effd3c
SM		 2641 if (dlm_is_lockres_migrateable(dlm, res))
2642 target = dlm_pick_migration_target(dlm, res);
b36c3f84 2643 spin_unlock(&res->spinlock);
66effd3c
SM		 2644
2645 if (target == O2NM_MAX_NODES)
9f62e960 2646 goto leave;
ba2bf218
KH		 2647
2648 /* Wheee! Migrate lockres here! Will sleep so drop spinlock. */
2649 spin_unlock(&dlm->spinlock);
2650 lock_dropped = 1;
66effd3c
SM		 2651 ret = dlm_migrate_lockres(dlm, res, target);
2652 if (ret)
2653 mlog(0, "%s: res %.*s, Migrate to node %u failed with %d\n",
2654 dlm->name, res->lockname.len, res->lockname.name,
2655 target, ret);
ba2bf218
KH		 2656 spin_lock(&dlm->spinlock);
2657leave:
2658 return lock_dropped;
2659}
2660
6714d8e8
KH		 2661int dlm_lock_basts_flushed(struct dlm_ctxt *dlm, struct dlm_lock *lock)
2662{
2663 int ret;
2664 spin_lock(&dlm->ast_lock);
2665 spin_lock(&lock->spinlock);
2666 ret = (list_empty(&lock->bast_list) && !lock->bast_pending);
2667 spin_unlock(&lock->spinlock);
2668 spin_unlock(&dlm->ast_lock);
2669 return ret;
2670}
2671
2672static int dlm_migration_can_proceed(struct dlm_ctxt *dlm,
2673 struct dlm_lock_resource *res,
2674 u8 mig_target)
2675{
2676 int can_proceed;
2677 spin_lock(&res->spinlock);
2678 can_proceed = !!(res->state & DLM_LOCK_RES_MIGRATING);
2679 spin_unlock(&res->spinlock);
2680
2bd63216 2681 /* target has died, so make the caller break out of the
6714d8e8
KH		 2682 * wait_event, but caller must recheck the domain_map */
2683 spin_lock(&dlm->spinlock);
2684 if (!test_bit(mig_target, dlm->domain_map))
2685 can_proceed = 1;
2686 spin_unlock(&dlm->spinlock);
2687 return can_proceed;
2688}
2689
faf0ec9f
AB		 2690static int dlm_lockres_is_dirty(struct dlm_ctxt *dlm,
2691 struct dlm_lock_resource *res)
6714d8e8
KH		 2692{
2693 int ret;
2694 spin_lock(&res->spinlock);
2695 ret = !!(res->state & DLM_LOCK_RES_DIRTY);
2696 spin_unlock(&res->spinlock);
2697 return ret;
2698}
2699
2700
2701static int dlm_mark_lockres_migrating(struct dlm_ctxt *dlm,
2702 struct dlm_lock_resource *res,
2703 u8 target)
2704{
2705 int ret = 0;
2706
2707 mlog(0, "dlm_mark_lockres_migrating: %.*s, from %u to %u\n",
2708 res->lockname.len, res->lockname.name, dlm->node_num,
2709 target);
2710 /* need to set MIGRATING flag on lockres. this is done by
2711 * ensuring that all asts have been flushed for this lockres. */
2712 spin_lock(&res->spinlock);
2713 BUG_ON(res->migration_pending);
2714 res->migration_pending = 1;
2715 /* strategy is to reserve an extra ast then release
2716 * it below, letting the release do all of the work */
2717 __dlm_lockres_reserve_ast(res);
2718 spin_unlock(&res->spinlock);
2719
ddc09c8d 2720 /* now flush all the pending asts */
6714d8e8 2721 dlm_kick_thread(dlm, res);
ddc09c8d
KH		 2722 /* before waiting on DIRTY, block processes which may
2723 * try to dirty the lockres before MIGRATING is set */
2724 spin_lock(&res->spinlock);
2725 BUG_ON(res->state & DLM_LOCK_RES_BLOCK_DIRTY);
2726 res->state |= DLM_LOCK_RES_BLOCK_DIRTY;
2727 spin_unlock(&res->spinlock);
2728 /* now wait on any pending asts and the DIRTY state */
6714d8e8
KH		 2729 wait_event(dlm->ast_wq, !dlm_lockres_is_dirty(dlm, res));
2730 dlm_lockres_release_ast(dlm, res);
2731
2732 mlog(0, "about to wait on migration_wq, dirty=%s\n",
2733 res->state & DLM_LOCK_RES_DIRTY ? "yes" : "no");
2734 /* if the extra ref we just put was the final one, this
2735 * will pass thru immediately. otherwise, we need to wait
2736 * for the last ast to finish. */
2737again:
2738 ret = wait_event_interruptible_timeout(dlm->migration_wq,
2739 dlm_migration_can_proceed(dlm, res, target),
2740 msecs_to_jiffies(1000));
2741 if (ret < 0) {
2742 mlog(0, "woken again: migrating? %s, dead? %s\n",
2743 res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no",
2744 test_bit(target, dlm->domain_map) ? "no":"yes");
2745 } else {
2746 mlog(0, "all is well: migrating? %s, dead? %s\n",
2747 res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no",
2748 test_bit(target, dlm->domain_map) ? "no":"yes");
2749 }
2750 if (!dlm_migration_can_proceed(dlm, res, target)) {
2751 mlog(0, "trying again...\n");
2752 goto again;
2753 }
2754
a39953dd 2755 ret = 0;
6714d8e8
KH		 2756 /* did the target go down or die? */
2757 spin_lock(&dlm->spinlock);
2758 if (!test_bit(target, dlm->domain_map)) {
2759 mlog(ML_ERROR, "aha. migration target %u just went down\n",
2760 target);
2761 ret = -EHOSTDOWN;
2762 }
2763 spin_unlock(&dlm->spinlock);
2764
a39953dd
WW		 2765 /*
2766 * if target is down, we need to clear DLM_LOCK_RES_BLOCK_DIRTY for
2767 * another try; otherwise, we are sure the MIGRATING state is there,
2768 * drop the unneded state which blocked threads trying to DIRTY
2769 */
2770 spin_lock(&res->spinlock);
2771 BUG_ON(!(res->state & DLM_LOCK_RES_BLOCK_DIRTY));
2772 res->state &= ~DLM_LOCK_RES_BLOCK_DIRTY;
2773 if (!ret)
2774 BUG_ON(!(res->state & DLM_LOCK_RES_MIGRATING));
2775 spin_unlock(&res->spinlock);
2776
6714d8e8
KH		 2777 /*
2778 * at this point:
2779 *
a39953dd 2780 * o the DLM_LOCK_RES_MIGRATING flag is set if target not down
6714d8e8
KH		 2781 * o there are no pending asts on this lockres
2782 * o all processes trying to reserve an ast on this
2783 * lockres must wait for the MIGRATING flag to clear
2784 */
2785 return ret;
2786}
2787
2788/* last step in the migration process.
2789 * original master calls this to free all of the dlm_lock
2790 * structures that used to be for other nodes. */
2791static void dlm_remove_nonlocal_locks(struct dlm_ctxt *dlm,
2792 struct dlm_lock_resource *res)
2793{
6714d8e8 2794 struct list_head *queue = &res->granted;
ba2bf218 2795 int i, bit;
800deef3 2796 struct dlm_lock *lock, *next;
6714d8e8
KH		 2797
2798 assert_spin_locked(&res->spinlock);
2799
2800 BUG_ON(res->owner == dlm->node_num);
2801
2802 for (i=0; i<3; i++) {
800deef3 2803 list_for_each_entry_safe(lock, next, queue, list) {
6714d8e8
KH		 2804 if (lock->ml.node != dlm->node_num) {
2805 mlog(0, "putting lock for node %u\n",
2806 lock->ml.node);
2807 /* be extra careful */
2808 BUG_ON(!list_empty(&lock->ast_list));
2809 BUG_ON(!list_empty(&lock->bast_list));
2810 BUG_ON(lock->ast_pending);
2811 BUG_ON(lock->bast_pending);
8d400b81
SM		 2812 dlm_lockres_clear_refmap_bit(dlm, res,
2813 lock->ml.node);
6714d8e8
KH		 2814 list_del_init(&lock->list);
2815 dlm_lock_put(lock);
2c5c54ac
SM		 2816 /* In a normal unlock, we would have added a
2817 * DLM_UNLOCK_FREE_LOCK action. Force it. */
2818 dlm_lock_put(lock);
6714d8e8
KH		 2819 }
2820 }
2821 queue++;
2822 }
ba2bf218
KH		 2823 bit = 0;
2824 while (1) {
2825 bit = find_next_bit(res->refmap, O2NM_MAX_NODES, bit);
2826 if (bit >= O2NM_MAX_NODES)
2827 break;
2828 /* do not clear the local node reference, if there is a
2829 * process holding this, let it drop the ref itself */
2830 if (bit != dlm->node_num) {
2831 mlog(0, "%s:%.*s: node %u had a ref to this "
2832 "migrating lockres, clearing\n", dlm->name,
2833 res->lockname.len, res->lockname.name, bit);
8d400b81 2834 dlm_lockres_clear_refmap_bit(dlm, res, bit);
ba2bf218
KH		 2835 }
2836 bit++;
2837 }
6714d8e8
KH		 2838}
2839
66effd3c
SM		 2840/*
2841 * Pick a node to migrate the lock resource to. This function selects a
2842 * potential target based first on the locks and then on refmap. It skips
2843 * nodes that are in the process of exiting the domain.
2844 */
6714d8e8
KH		 2845static u8 dlm_pick_migration_target(struct dlm_ctxt *dlm,
2846 struct dlm_lock_resource *res)
2847{
66effd3c 2848 enum dlm_lockres_list idx;
6714d8e8 2849 struct list_head *queue = &res->granted;
6714d8e8 2850 struct dlm_lock *lock;
66effd3c
SM		 2851 int noderef;
2852 u8 nodenum = O2NM_MAX_NODES;
6714d8e8
KH		 2853
2854 assert_spin_locked(&dlm->spinlock);
66effd3c 2855 assert_spin_locked(&res->spinlock);
6714d8e8 2856
66effd3c
SM		 2857 /* Go through all the locks */
2858 for (idx = DLM_GRANTED_LIST; idx <= DLM_BLOCKED_LIST; idx++) {
2859 queue = dlm_list_idx_to_ptr(res, idx);
800deef3 2860 list_for_each_entry(lock, queue, list) {
66effd3c
SM		 2861 if (lock->ml.node == dlm->node_num)
2862 continue;
2863 if (test_bit(lock->ml.node, dlm->exit_domain_map))
2864 continue;
2865 nodenum = lock->ml.node;
2866 goto bail;
6714d8e8 2867 }
6714d8e8 2868 }
388c4bcb 2869
66effd3c
SM		 2870 /* Go thru the refmap */
2871 noderef = -1;
6714d8e8 2872 while (1) {
66effd3c
SM		 2873 noderef = find_next_bit(res->refmap, O2NM_MAX_NODES,
2874 noderef + 1);
2875 if (noderef >= O2NM_MAX_NODES)
6714d8e8 2876 break;
66effd3c
SM		 2877 if (noderef == dlm->node_num)
2878 continue;
2879 if (test_bit(noderef, dlm->exit_domain_map))
2880 continue;
2881 nodenum = noderef;
2882 goto bail;
6714d8e8
KH		 2883 }
2884
66effd3c
SM		 2885bail:
2886 return nodenum;
6714d8e8
KH		 2887}
2888
6714d8e8
KH		 2889/* this is called by the new master once all lockres
2890 * data has been received */
2891static int dlm_do_migrate_request(struct dlm_ctxt *dlm,
2892 struct dlm_lock_resource *res,
2893 u8 master, u8 new_master,
2894 struct dlm_node_iter *iter)
2895{
2896 struct dlm_migrate_request migrate;
2b832564 2897 int ret, skip, status = 0;
6714d8e8
KH		 2898 int nodenum;
2899
2900 memset(&migrate, 0, sizeof(migrate));
2901 migrate.namelen = res->lockname.len;
2902 memcpy(migrate.name, res->lockname.name, migrate.namelen);
2903 migrate.new_master = new_master;
2904 migrate.master = master;
2905
2906 ret = 0;
2907
2908 /* send message to all nodes, except the master and myself */
2909 while ((nodenum = dlm_node_iter_next(iter)) >= 0) {
2910 if (nodenum == master ||
2911 nodenum == new_master)
2912 continue;
2913
2b832564
SM		 2914 /* We could race exit domain. If exited, skip. */
2915 spin_lock(&dlm->spinlock);
2916 skip = (!test_bit(nodenum, dlm->domain_map));
2917 spin_unlock(&dlm->spinlock);
2918 if (skip) {
2919 clear_bit(nodenum, iter->node_map);
2920 continue;
2921 }
2922
6714d8e8
KH		 2923 ret = o2net_send_message(DLM_MIGRATE_REQUEST_MSG, dlm->key,
2924 &migrate, sizeof(migrate), nodenum,
2925 &status);
2b832564 2926 if (ret < 0) {
8decab3c
SM		 2927 mlog(ML_ERROR, "%s: res %.*s, Error %d send "
2928 "MIGRATE_REQUEST to node %u\n", dlm->name,
2929 migrate.namelen, migrate.name, ret, nodenum);
2b832564
SM		 2930 if (!dlm_is_host_down(ret)) {
2931 mlog(ML_ERROR, "unhandled error=%d!\n", ret);
2932 BUG();
2933 }
2934 clear_bit(nodenum, iter->node_map);
2935 ret = 0;
2936 } else if (status < 0) {
6714d8e8
KH		 2937 mlog(0, "migrate request (node %u) returned %d!\n",
2938 nodenum, status);
2939 ret = status;
ba2bf218
KH		 2940 } else if (status == DLM_MIGRATE_RESPONSE_MASTERY_REF) {
2941 /* during the migration request we short-circuited
2942 * the mastery of the lockres. make sure we have
2943 * a mastery ref for nodenum */
2944 mlog(0, "%s:%.*s: need ref for node %u\n",
2945 dlm->name, res->lockname.len, res->lockname.name,
2946 nodenum);
2947 spin_lock(&res->spinlock);
8d400b81 2948 dlm_lockres_set_refmap_bit(dlm, res, nodenum);
ba2bf218 2949 spin_unlock(&res->spinlock);
6714d8e8
KH		 2950 }
2951 }
2952
2953 if (ret < 0)
2954 mlog_errno(ret);
2955
2956 mlog(0, "returning ret=%d\n", ret);
2957 return ret;
2958}
2959
2960
2961/* if there is an existing mle for this lockres, we now know who the master is.
2962 * (the one who sent us *this* message) we can clear it up right away.
2963 * since the process that put the mle on the list still has a reference to it,
2964 * we can unhash it now, set the master and wake the process. as a result,
2965 * we will have no mle in the list to start with. now we can add an mle for
2966 * the migration and this should be the only one found for those scanning the
2967 * list. */
d74c9803
KH		 2968int dlm_migrate_request_handler(struct o2net_msg *msg, u32 len, void *data,
2969 void **ret_data)
6714d8e8
KH		 2970{
2971 struct dlm_ctxt *dlm = data;
2972 struct dlm_lock_resource *res = NULL;
2973 struct dlm_migrate_request *migrate = (struct dlm_migrate_request *) msg->buf;
2974 struct dlm_master_list_entry *mle = NULL, *oldmle = NULL;
2975 const char *name;
a3d33291 2976 unsigned int namelen, hash;
6714d8e8
KH		 2977 int ret = 0;
2978
2979 if (!dlm_grab(dlm))
2980 return -EINVAL;
2981
2982 name = migrate->name;
2983 namelen = migrate->namelen;
a3d33291 2984 hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 2985
2986 /* preallocate.. if this fails, abort */
3914ed0c 2987 mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
6714d8e8
KH		 2988
2989 if (!mle) {
2990 ret = -ENOMEM;
2991 goto leave;
2992 }
2993
2994 /* check for pre-existing lock */
2995 spin_lock(&dlm->spinlock);
a3d33291 2996 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
6714d8e8
KH		 2997 if (res) {
2998 spin_lock(&res->spinlock);
2999 if (res->state & DLM_LOCK_RES_RECOVERING) {
3000 /* if all is working ok, this can only mean that we got
3001 * a migrate request from a node that we now see as
3002 * dead. what can we do here? drop it to the floor? */
3003 spin_unlock(&res->spinlock);
3004 mlog(ML_ERROR, "Got a migrate request, but the "
3005 "lockres is marked as recovering!");
3006 kmem_cache_free(dlm_mle_cache, mle);
3007 ret = -EINVAL; /* need a better solution */
3008 goto unlock;
3009 }
3010 res->state |= DLM_LOCK_RES_MIGRATING;
3011 spin_unlock(&res->spinlock);
3012 }
3013
6d98c3cc 3014 spin_lock(&dlm->master_lock);
6714d8e8
KH		 3015 /* ignore status. only nonzero status would BUG. */
3016 ret = dlm_add_migration_mle(dlm, res, mle, &oldmle,
3017 name, namelen,
3018 migrate->new_master,
3019 migrate->master);
3020
6714d8e8 3021 spin_unlock(&dlm->master_lock);
6d98c3cc 3022unlock:
6714d8e8
KH		 3023 spin_unlock(&dlm->spinlock);
3024
3025 if (oldmle) {
3026 /* master is known, detach if not already detached */
3027 dlm_mle_detach_hb_events(dlm, oldmle);
3028 dlm_put_mle(oldmle);
3029 }
3030
3031 if (res)
3032 dlm_lockres_put(res);
3033leave:
3034 dlm_put(dlm);
3035 return ret;
3036}
3037
3038/* must be holding dlm->spinlock and dlm->master_lock
3039 * when adding a migration mle, we can clear any other mles
3040 * in the master list because we know with certainty that
3041 * the master is "master". so we remove any old mle from
3042 * the list after setting it's master field, and then add
3043 * the new migration mle. this way we can hold with the rule
3044 * of having only one mle for a given lock name at all times. */
3045static int dlm_add_migration_mle(struct dlm_ctxt *dlm,
3046 struct dlm_lock_resource *res,
3047 struct dlm_master_list_entry *mle,
3048 struct dlm_master_list_entry **oldmle,
3049 const char *name, unsigned int namelen,
3050 u8 new_master, u8 master)
3051{
3052 int found;
3053 int ret = 0;
3054
3055 *oldmle = NULL;
3056
6714d8e8
KH		 3057 assert_spin_locked(&dlm->spinlock);
3058 assert_spin_locked(&dlm->master_lock);
3059
3060 /* caller is responsible for any ref taken here on oldmle */
3061 found = dlm_find_mle(dlm, oldmle, (char *)name, namelen);
3062 if (found) {
3063 struct dlm_master_list_entry *tmp = *oldmle;
3064 spin_lock(&tmp->spinlock);
3065 if (tmp->type == DLM_MLE_MIGRATION) {
3066 if (master == dlm->node_num) {
3067 /* ah another process raced me to it */
3068 mlog(0, "tried to migrate %.*s, but some "
3069 "process beat me to it\n",
3070 namelen, name);
3071 ret = -EEXIST;
3072 } else {
3073 /* bad. 2 NODES are trying to migrate! */
3074 mlog(ML_ERROR, "migration error mle: "
3075 "master=%u new_master=%u // request: "
3076 "master=%u new_master=%u // "
3077 "lockres=%.*s\n",
3078 tmp->master, tmp->new_master,
3079 master, new_master,
3080 namelen, name);
3081 BUG();
3082 }
3083 } else {
3084 /* this is essentially what assert_master does */
3085 tmp->master = master;
3086 atomic_set(&tmp->woken, 1);
3087 wake_up(&tmp->wq);
1c084577
SM		 3088 /* remove it so that only one mle will be found */
3089 __dlm_unlink_mle(dlm, tmp);
ba2bf218 3090 __dlm_mle_detach_hb_events(dlm, tmp);
b9aaac5a 3091 if (tmp->type == DLM_MLE_MASTER) {
3092 ret = DLM_MIGRATE_RESPONSE_MASTERY_REF;
3093 mlog(0, "%s:%.*s: master=%u, newmaster=%u, "
3094 "telling master to get ref "
3095 "for cleared out mle during "
3096 "migration\n", dlm->name,
3097 namelen, name, master,
3098 new_master);
3099 }
6714d8e8
KH		 3100 }
3101 spin_unlock(&tmp->spinlock);
3102 }
3103
3104 /* now add a migration mle to the tail of the list */
3105 dlm_init_mle(mle, DLM_MLE_MIGRATION, dlm, res, name, namelen);
3106 mle->new_master = new_master;
ba2bf218
KH		 3107 /* the new master will be sending an assert master for this.
3108 * at that point we will get the refmap reference */
6714d8e8
KH		 3109 mle->master = master;
3110 /* do this for consistency with other mle types */
3111 set_bit(new_master, mle->maybe_map);
1c084577 3112 __dlm_insert_mle(dlm, mle);
6714d8e8
KH		 3113
3114 return ret;
3115}
3116
c2cd4a44
SM		 3117/*
3118 * Sets the owner of the lockres, associated to the mle, to UNKNOWN
3119 */
3120static struct dlm_lock_resource *dlm_reset_mleres_owner(struct dlm_ctxt *dlm,
3121 struct dlm_master_list_entry *mle)
3122{
3123 struct dlm_lock_resource *res;
c2cd4a44
SM		 3124
3125 /* Find the lockres associated to the mle and set its owner to UNK */
7141514b
SM		 3126 res = __dlm_lookup_lockres(dlm, mle->mname, mle->mnamelen,
3127 mle->mnamehash);
c2cd4a44
SM		 3128 if (res) {
3129 spin_unlock(&dlm->master_lock);
3130
3131 /* move lockres onto recovery list */
3132 spin_lock(&res->spinlock);
3133 dlm_set_lockres_owner(dlm, res, DLM_LOCK_RES_OWNER_UNKNOWN);
3134 dlm_move_lockres_to_recovery_list(dlm, res);
3135 spin_unlock(&res->spinlock);
3136 dlm_lockres_put(res);
3137
3138 /* about to get rid of mle, detach from heartbeat */
3139 __dlm_mle_detach_hb_events(dlm, mle);
3140
3141 /* dump the mle */
3142 spin_lock(&dlm->master_lock);
3143 __dlm_put_mle(mle);
3144 spin_unlock(&dlm->master_lock);
3145 }
3146
3147 return res;
3148}
3149
3150static void dlm_clean_migration_mle(struct dlm_ctxt *dlm,
3151 struct dlm_master_list_entry *mle)
3152{
3153 __dlm_mle_detach_hb_events(dlm, mle);
3154
3155 spin_lock(&mle->spinlock);
3156 __dlm_unlink_mle(dlm, mle);
3157 atomic_set(&mle->woken, 1);
3158 spin_unlock(&mle->spinlock);
3159
3160 wake_up(&mle->wq);
3161}
3162
3163static void dlm_clean_block_mle(struct dlm_ctxt *dlm,
3164 struct dlm_master_list_entry *mle, u8 dead_node)
3165{
3166 int bit;
3167
3168 BUG_ON(mle->type != DLM_MLE_BLOCK);
3169
3170 spin_lock(&mle->spinlock);
3171 bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0);
3172 if (bit != dead_node) {
3173 mlog(0, "mle found, but dead node %u would not have been "
3174 "master\n", dead_node);
3175 spin_unlock(&mle->spinlock);
3176 } else {
3177 /* Must drop the refcount by one since the assert_master will
3178 * never arrive. This may result in the mle being unlinked and
3179 * freed, but there may still be a process waiting in the
3180 * dlmlock path which is fine. */
3181 mlog(0, "node %u was expected master\n", dead_node);
3182 atomic_set(&mle->woken, 1);
3183 spin_unlock(&mle->spinlock);
3184 wake_up(&mle->wq);
3185
3186 /* Do not need events any longer, so detach from heartbeat */
3187 __dlm_mle_detach_hb_events(dlm, mle);
3188 __dlm_put_mle(mle);
3189 }
3190}
6714d8e8
KH		 3191
3192void dlm_clean_master_list(struct dlm_ctxt *dlm, u8 dead_node)
3193{
2ed6c750 3194 struct dlm_master_list_entry *mle;
6714d8e8 3195 struct dlm_lock_resource *res;
2ed6c750 3196 struct hlist_head *bucket;
df53cd3b 3197 struct hlist_node *tmp;
2ed6c750 3198 unsigned int i;
6714d8e8 3199
ef6b689b 3200 mlog(0, "dlm=%s, dead node=%u\n", dlm->name, dead_node);
6714d8e8
KH		 3201top:
3202 assert_spin_locked(&dlm->spinlock);
3203
3204 /* clean the master list */
3205 spin_lock(&dlm->master_lock);
2ed6c750
SM		 3206 for (i = 0; i < DLM_HASH_BUCKETS; i++) {
3207 bucket = dlm_master_hash(dlm, i);
df53cd3b 3208 hlist_for_each_entry_safe(mle, tmp, bucket, master_hash_node) {
67ae1f06
SM		 3209 BUG_ON(mle->type != DLM_MLE_BLOCK &&
3210 mle->type != DLM_MLE_MASTER &&
3211 mle->type != DLM_MLE_MIGRATION);
3212
3213 /* MASTER mles are initiated locally. The waiting
3214 * process will notice the node map change shortly.
3215 * Let that happen as normal. */
3216 if (mle->type == DLM_MLE_MASTER)
3217 continue;
3218
3219 /* BLOCK mles are initiated by other nodes. Need to
3220 * clean up if the dead node would have been the
3221 * master. */
3222 if (mle->type == DLM_MLE_BLOCK) {
3223 dlm_clean_block_mle(dlm, mle, dead_node);
3224 continue;
3225 }
6714d8e8 3226
67ae1f06
SM		 3227 /* Everything else is a MIGRATION mle */
3228
3229 /* The rule for MIGRATION mles is that the master
3230 * becomes UNKNOWN if *either* the original or the new
3231 * master dies. All UNKNOWN lockres' are sent to
3232 * whichever node becomes the recovery master. The new
3233 * master is responsible for determining if there is
3234 * still a master for this lockres, or if he needs to
3235 * take over mastery. Either way, this node should
3236 * expect another message to resolve this. */
3237
3238 if (mle->master != dead_node &&
3239 mle->new_master != dead_node)
3240 continue;
3241
3242 /* If we have reached this point, this mle needs to be
3243 * removed from the list and freed. */
3244 dlm_clean_migration_mle(dlm, mle);
3245
3246 mlog(0, "%s: node %u died during migration from "
3247 "%u to %u!\n", dlm->name, dead_node, mle->master,
3248 mle->new_master);
3249
3250 /* If we find a lockres associated with the mle, we've
3251 * hit this rare case that messes up our lock ordering.
3252 * If so, we need to drop the master lock so that we can
3253 * take the lockres lock, meaning that we will have to
3254 * restart from the head of list. */
3255 res = dlm_reset_mleres_owner(dlm, mle);
3256 if (res)
3257 /* restart */
3258 goto top;
3259
3260 /* This may be the last reference */
3261 __dlm_put_mle(mle);
6714d8e8 3262 }
2ed6c750 3263 }
6714d8e8
KH		 3264 spin_unlock(&dlm->master_lock);
3265}
3266
6714d8e8
KH		 3267int dlm_finish_migration(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
3268 u8 old_master)
3269{
3270 struct dlm_node_iter iter;
3271 int ret = 0;
3272
3273 spin_lock(&dlm->spinlock);
3274 dlm_node_iter_init(dlm->domain_map, &iter);
3275 clear_bit(old_master, iter.node_map);
3276 clear_bit(dlm->node_num, iter.node_map);
3277 spin_unlock(&dlm->spinlock);
3278
ba2bf218
KH		 3279 /* ownership of the lockres is changing. account for the
3280 * mastery reference here since old_master will briefly have
3281 * a reference after the migration completes */
3282 spin_lock(&res->spinlock);
8d400b81 3283 dlm_lockres_set_refmap_bit(dlm, res, old_master);
ba2bf218
KH		 3284 spin_unlock(&res->spinlock);
3285
6714d8e8
KH		 3286 mlog(0, "now time to do a migrate request to other nodes\n");
3287 ret = dlm_do_migrate_request(dlm, res, old_master,
3288 dlm->node_num, &iter);
3289 if (ret < 0) {
3290 mlog_errno(ret);
3291 goto leave;
3292 }
3293
3294 mlog(0, "doing assert master of %.*s to all except the original node\n",
3295 res->lockname.len, res->lockname.name);
3296 /* this call now finishes out the nodemap
3297 * even if one or more nodes die */
ba2bf218 3298 ret = dlm_do_assert_master(dlm, res, iter.node_map,
6714d8e8
KH		 3299 DLM_ASSERT_MASTER_FINISH_MIGRATION);
3300 if (ret < 0) {
3301 /* no longer need to retry. all living nodes contacted. */
3302 mlog_errno(ret);
3303 ret = 0;
3304 }
3305
3306 memset(iter.node_map, 0, sizeof(iter.node_map));
3307 set_bit(old_master, iter.node_map);
3308 mlog(0, "doing assert master of %.*s back to %u\n",
3309 res->lockname.len, res->lockname.name, old_master);
ba2bf218 3310 ret = dlm_do_assert_master(dlm, res, iter.node_map,
6714d8e8
KH		 3311 DLM_ASSERT_MASTER_FINISH_MIGRATION);
3312 if (ret < 0) {
3313 mlog(0, "assert master to original master failed "
3314 "with %d.\n", ret);
3315 /* the only nonzero status here would be because of
3316 * a dead original node. we're done. */
3317 ret = 0;
3318 }
3319
3320 /* all done, set the owner, clear the flag */
3321 spin_lock(&res->spinlock);
3322 dlm_set_lockres_owner(dlm, res, dlm->node_num);
3323 res->state &= ~DLM_LOCK_RES_MIGRATING;
3324 spin_unlock(&res->spinlock);
3325 /* re-dirty it on the new master */
3326 dlm_kick_thread(dlm, res);
3327 wake_up(&res->wq);
3328leave:
3329 return ret;
3330}
3331
3332/*
3333 * LOCKRES AST REFCOUNT
3334 * this is integral to migration
3335 */
3336
3337/* for future intent to call an ast, reserve one ahead of time.
3338 * this should be called only after waiting on the lockres
3339 * with dlm_wait_on_lockres, and while still holding the
3340 * spinlock after the call. */
3341void __dlm_lockres_reserve_ast(struct dlm_lock_resource *res)
3342{
3343 assert_spin_locked(&res->spinlock);
3344 if (res->state & DLM_LOCK_RES_MIGRATING) {
3345 __dlm_print_one_lock_resource(res);
3346 }
3347 BUG_ON(res->state & DLM_LOCK_RES_MIGRATING);
3348
3349 atomic_inc(&res->asts_reserved);
3350}
3351
3352/*
3353 * used to drop the reserved ast, either because it went unused,
3354 * or because the ast/bast was actually called.
3355 *
3356 * also, if there is a pending migration on this lockres,
3357 * and this was the last pending ast on the lockres,
3358 * atomically set the MIGRATING flag before we drop the lock.
3359 * this is how we ensure that migration can proceed with no
3360 * asts in progress. note that it is ok if the state of the
3361 * queues is such that a lock should be granted in the future
3362 * or that a bast should be fired, because the new master will
3363 * shuffle the lists on this lockres as soon as it is migrated.
3364 */
3365void dlm_lockres_release_ast(struct dlm_ctxt *dlm,
3366 struct dlm_lock_resource *res)
3367{
3368 if (!atomic_dec_and_lock(&res->asts_reserved, &res->spinlock))
3369 return;
3370
3371 if (!res->migration_pending) {
3372 spin_unlock(&res->spinlock);
3373 return;
3374 }
3375
3376 BUG_ON(res->state & DLM_LOCK_RES_MIGRATING);
3377 res->migration_pending = 0;
3378 res->state |= DLM_LOCK_RES_MIGRATING;
3379 spin_unlock(&res->spinlock);
3380 wake_up(&res->wq);
3381 wake_up(&dlm->migration_wq);
3382}
5dad6c39
SE		 3383
3384void dlm_force_free_mles(struct dlm_ctxt *dlm)
3385{
3386 int i;
3387 struct hlist_head *bucket;
3388 struct dlm_master_list_entry *mle;
df53cd3b 3389 struct hlist_node *tmp;
5dad6c39
SE		 3390
3391 /*
3392 * We notified all other nodes that we are exiting the domain and
3393 * marked the dlm state to DLM_CTXT_LEAVING. If any mles are still
3394 * around we force free them and wake any processes that are waiting
3395 * on the mles
3396 */
3397 spin_lock(&dlm->spinlock);
3398 spin_lock(&dlm->master_lock);
3399
3400 BUG_ON(dlm->dlm_state != DLM_CTXT_LEAVING);
3401 BUG_ON((find_next_bit(dlm->domain_map, O2NM_MAX_NODES, 0) < O2NM_MAX_NODES));
3402
3403 for (i = 0; i < DLM_HASH_BUCKETS; i++) {
3404 bucket = dlm_master_hash(dlm, i);
df53cd3b 3405 hlist_for_each_entry_safe(mle, tmp, bucket, master_hash_node) {
5dad6c39
SE		 3406 if (mle->type != DLM_MLE_BLOCK) {
3407 mlog(ML_ERROR, "bad mle: %p\n", mle);
3408 dlm_print_one_mle(mle);
3409 }
3410 atomic_set(&mle->woken, 1);
3411 wake_up(&mle->wq);
3412
3413 __dlm_unlink_mle(dlm, mle);
3414 __dlm_mle_detach_hb_events(dlm, mle);
3415 __dlm_put_mle(mle);
3416 }
3417 }
3418 spin_unlock(&dlm->master_lock);
3419 spin_unlock(&dlm->spinlock);
3420}
Linux 6.x block layer and io_uring tree(s)