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ocfs2: skip locks in the blocked list
[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
724bdca9
SM		 85static struct kmem_cache *dlm_lockres_cache = NULL;
86static struct kmem_cache *dlm_lockname_cache = NULL;
e18b890b 87static struct kmem_cache *dlm_mle_cache = NULL;
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{
475 if (dlm_lockname_cache)
476 kmem_cache_destroy(dlm_lockname_cache);
477
478 if (dlm_lockres_cache)
479 kmem_cache_destroy(dlm_lockres_cache);
480}
481
6714d8e8
KH		 482static void dlm_lockres_release(struct kref *kref)
483{
484 struct dlm_lock_resource *res;
b0d4f817 485 struct dlm_ctxt *dlm;
6714d8e8
KH		 486
487 res = container_of(kref, struct dlm_lock_resource, refs);
b0d4f817 488 dlm = res->dlm;
6714d8e8
KH		 489
490 /* This should not happen -- all lockres' have a name
491 * associated with them at init time. */
492 BUG_ON(!res->lockname.name);
493
494 mlog(0, "destroying lockres %.*s\n", res->lockname.len,
495 res->lockname.name);
496
b0d4f817 497 spin_lock(&dlm->track_lock);
29576f8b
SM		 498 if (!list_empty(&res->tracking))
499 list_del_init(&res->tracking);
500 else {
501 mlog(ML_ERROR, "Resource %.*s not on the Tracking list\n",
502 res->lockname.len, res->lockname.name);
503 dlm_print_one_lock_resource(res);
504 }
b0d4f817
SM		 505 spin_unlock(&dlm->track_lock);
506
6800791a
SM		 507 atomic_dec(&dlm->res_cur_count);
508
a7f90d83
KH		 509 if (!hlist_unhashed(&res->hash_node) ||
510 !list_empty(&res->granted) ||
511 !list_empty(&res->converting) ||
512 !list_empty(&res->blocked) ||
513 !list_empty(&res->dirty) ||
514 !list_empty(&res->recovering) ||
515 !list_empty(&res->purge)) {
516 mlog(ML_ERROR,
517 "Going to BUG for resource %.*s."
518 " We're on a list! [%c%c%c%c%c%c%c]\n",
519 res->lockname.len, res->lockname.name,
520 !hlist_unhashed(&res->hash_node) ? 'H' : ' ',
521 !list_empty(&res->granted) ? 'G' : ' ',
522 !list_empty(&res->converting) ? 'C' : ' ',
523 !list_empty(&res->blocked) ? 'B' : ' ',
524 !list_empty(&res->dirty) ? 'D' : ' ',
525 !list_empty(&res->recovering) ? 'R' : ' ',
526 !list_empty(&res->purge) ? 'P' : ' ');
527
528 dlm_print_one_lock_resource(res);
529 }
530
6714d8e8
KH		 531 /* By the time we're ready to blow this guy away, we shouldn't
532 * be on any lists. */
81f2094a 533 BUG_ON(!hlist_unhashed(&res->hash_node));
6714d8e8
KH		 534 BUG_ON(!list_empty(&res->granted));
535 BUG_ON(!list_empty(&res->converting));
536 BUG_ON(!list_empty(&res->blocked));
537 BUG_ON(!list_empty(&res->dirty));
538 BUG_ON(!list_empty(&res->recovering));
539 BUG_ON(!list_empty(&res->purge));
540
724bdca9 541 kmem_cache_free(dlm_lockname_cache, (void *)res->lockname.name);
6714d8e8 542
724bdca9 543 kmem_cache_free(dlm_lockres_cache, res);
6714d8e8
KH		 544}
545
6714d8e8
KH		 546void dlm_lockres_put(struct dlm_lock_resource *res)
547{
548 kref_put(&res->refs, dlm_lockres_release);
549}
550
551static void dlm_init_lockres(struct dlm_ctxt *dlm,
552 struct dlm_lock_resource *res,
553 const char *name, unsigned int namelen)
554{
555 char *qname;
556
557 /* If we memset here, we lose our reference to the kmalloc'd
558 * res->lockname.name, so be sure to init every field
559 * correctly! */
560
561 qname = (char *) res->lockname.name;
562 memcpy(qname, name, namelen);
563
564 res->lockname.len = namelen;
a3d33291 565 res->lockname.hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 566
567 init_waitqueue_head(&res->wq);
568 spin_lock_init(&res->spinlock);
81f2094a 569 INIT_HLIST_NODE(&res->hash_node);
6714d8e8
KH		 570 INIT_LIST_HEAD(&res->granted);
571 INIT_LIST_HEAD(&res->converting);
572 INIT_LIST_HEAD(&res->blocked);
573 INIT_LIST_HEAD(&res->dirty);
574 INIT_LIST_HEAD(&res->recovering);
575 INIT_LIST_HEAD(&res->purge);
29576f8b 576 INIT_LIST_HEAD(&res->tracking);
6714d8e8
KH		 577 atomic_set(&res->asts_reserved, 0);
578 res->migration_pending = 0;
ba2bf218 579 res->inflight_locks = 0;
6714d8e8 580
b0d4f817
SM		 581 res->dlm = dlm;
582
6714d8e8
KH		 583 kref_init(&res->refs);
584
6800791a
SM		 585 atomic_inc(&dlm->res_tot_count);
586 atomic_inc(&dlm->res_cur_count);
587
6714d8e8
KH		 588 /* just for consistency */
589 spin_lock(&res->spinlock);
590 dlm_set_lockres_owner(dlm, res, DLM_LOCK_RES_OWNER_UNKNOWN);
591 spin_unlock(&res->spinlock);
592
593 res->state = DLM_LOCK_RES_IN_PROGRESS;
594
595 res->last_used = 0;
596
18c6ac38 597 spin_lock(&dlm->spinlock);
29576f8b 598 list_add_tail(&res->tracking, &dlm->tracking_list);
18c6ac38 599 spin_unlock(&dlm->spinlock);
29576f8b 600
6714d8e8 601 memset(res->lvb, 0, DLM_LVB_LEN);
ba2bf218 602 memset(res->refmap, 0, sizeof(res->refmap));
6714d8e8
KH		 603}
604
605struct dlm_lock_resource *dlm_new_lockres(struct dlm_ctxt *dlm,
606 const char *name,
607 unsigned int namelen)
608{
724bdca9 609 struct dlm_lock_resource *res = NULL;
6714d8e8 610
3914ed0c 611 res = kmem_cache_zalloc(dlm_lockres_cache, GFP_NOFS);
6714d8e8 612 if (!res)
724bdca9 613 goto error;
6714d8e8 614
3914ed0c 615 res->lockname.name = kmem_cache_zalloc(dlm_lockname_cache, GFP_NOFS);
724bdca9
SM		 616 if (!res->lockname.name)
617 goto error;
6714d8e8
KH		 618
619 dlm_init_lockres(dlm, res, name, namelen);
620 return res;
724bdca9
SM		 621
622error:
623 if (res && res->lockname.name)
624 kmem_cache_free(dlm_lockname_cache, (void *)res->lockname.name);
625
626 if (res)
627 kmem_cache_free(dlm_lockres_cache, res);
628 return NULL;
6714d8e8
KH		 629}
630
8d400b81
SM		 631void dlm_lockres_set_refmap_bit(struct dlm_ctxt *dlm,
632 struct dlm_lock_resource *res, int bit)
ba2bf218 633{
8d400b81
SM		 634 assert_spin_locked(&res->spinlock);
635
636 mlog(0, "res %.*s, set node %u, %ps()\n", res->lockname.len,
637 res->lockname.name, bit, __builtin_return_address(0));
638
639 set_bit(bit, res->refmap);
640}
641
642void dlm_lockres_clear_refmap_bit(struct dlm_ctxt *dlm,
643 struct dlm_lock_resource *res, int bit)
644{
645 assert_spin_locked(&res->spinlock);
646
647 mlog(0, "res %.*s, clr node %u, %ps()\n", res->lockname.len,
648 res->lockname.name, bit, __builtin_return_address(0));
649
650 clear_bit(bit, res->refmap);
651}
652
653
654void dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm,
655 struct dlm_lock_resource *res)
656{
657 assert_spin_locked(&res->spinlock);
ba2bf218 658
ba2bf218 659 res->inflight_locks++;
ff0a522e 660
8d400b81
SM		 661 mlog(0, "%s: res %.*s, inflight++: now %u, %ps()\n", dlm->name,
662 res->lockname.len, res->lockname.name, res->inflight_locks,
663 __builtin_return_address(0));
ba2bf218
KH		 664}
665
8d400b81
SM		 666void dlm_lockres_drop_inflight_ref(struct dlm_ctxt *dlm,
667 struct dlm_lock_resource *res)
ba2bf218
KH		 668{
669 assert_spin_locked(&res->spinlock);
670
671 BUG_ON(res->inflight_locks == 0);
8d400b81 672
ba2bf218 673 res->inflight_locks--;
ff0a522e 674
8d400b81
SM		 675 mlog(0, "%s: res %.*s, inflight--: now %u, %ps()\n", dlm->name,
676 res->lockname.len, res->lockname.name, res->inflight_locks,
677 __builtin_return_address(0));
678
ba2bf218
KH		 679 wake_up(&res->wq);
680}
681
6714d8e8
KH		 682/*
683 * lookup a lock resource by name.
684 * may already exist in the hashtable.
685 * lockid is null terminated
686 *
687 * if not, allocate enough for the lockres and for
688 * the temporary structure used in doing the mastering.
689 *
690 * also, do a lookup in the dlm->master_list to see
691 * if another node has begun mastering the same lock.
692 * if so, there should be a block entry in there
693 * for this name, and we should *not* attempt to master
694 * the lock here. need to wait around for that node
695 * to assert_master (or die).
696 *
697 */
698struct dlm_lock_resource * dlm_get_lock_resource(struct dlm_ctxt *dlm,
699 const char *lockid,
3384f3df 700 int namelen,
6714d8e8
KH		 701 int flags)
702{
703 struct dlm_lock_resource *tmpres=NULL, *res=NULL;
704 struct dlm_master_list_entry *mle = NULL;
705 struct dlm_master_list_entry *alloc_mle = NULL;
706 int blocked = 0;
707 int ret, nodenum;
708 struct dlm_node_iter iter;
3384f3df 709 unsigned int hash;
6714d8e8 710 int tries = 0;
c03872f5 711 int bit, wait_on_recovery = 0;
6714d8e8
KH		 712
713 BUG_ON(!lockid);
714
a3d33291 715 hash = dlm_lockid_hash(lockid, namelen);
6714d8e8
KH		 716
717 mlog(0, "get lockres %s (len %d)\n", lockid, namelen);
718
719lookup:
720 spin_lock(&dlm->spinlock);
ba2bf218 721 tmpres = __dlm_lookup_lockres_full(dlm, lockid, namelen, hash);
6714d8e8 722 if (tmpres) {
7b791d68 723 spin_unlock(&dlm->spinlock);
ba2bf218 724 spin_lock(&tmpres->spinlock);
ff0a522e 725 /* Wait on the thread that is mastering the resource */
7b791d68
SM		 726 if (tmpres->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
727 __dlm_wait_on_lockres(tmpres);
728 BUG_ON(tmpres->owner == DLM_LOCK_RES_OWNER_UNKNOWN);
ff0a522e
SM		 729 spin_unlock(&tmpres->spinlock);
730 dlm_lockres_put(tmpres);
731 tmpres = NULL;
732 goto lookup;
7b791d68
SM		 733 }
734
ff0a522e
SM		 735 /* Wait on the resource purge to complete before continuing */
736 if (tmpres->state & DLM_LOCK_RES_DROPPING_REF) {
737 BUG_ON(tmpres->owner == dlm->node_num);
738 __dlm_wait_on_lockres_flags(tmpres,
739 DLM_LOCK_RES_DROPPING_REF);
ba2bf218
KH		 740 spin_unlock(&tmpres->spinlock);
741 dlm_lockres_put(tmpres);
742 tmpres = NULL;
743 goto lookup;
744 }
745
ff0a522e
SM		 746 /* Grab inflight ref to pin the resource */
747 dlm_lockres_grab_inflight_ref(dlm, tmpres);
748
749 spin_unlock(&tmpres->spinlock);
6714d8e8
KH		 750 if (res)
751 dlm_lockres_put(res);
752 res = tmpres;
753 goto leave;
754 }
755
756 if (!res) {
757 spin_unlock(&dlm->spinlock);
758 mlog(0, "allocating a new resource\n");
759 /* nothing found and we need to allocate one. */
3914ed0c 760 alloc_mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
6714d8e8
KH		 761 if (!alloc_mle)
762 goto leave;
763 res = dlm_new_lockres(dlm, lockid, namelen);
764 if (!res)
765 goto leave;
766 goto lookup;
767 }
768
769 mlog(0, "no lockres found, allocated our own: %p\n", res);
770
771 if (flags & LKM_LOCAL) {
772 /* caller knows it's safe to assume it's not mastered elsewhere
773 * DONE! return right away */
774 spin_lock(&res->spinlock);
775 dlm_change_lockres_owner(dlm, res, dlm->node_num);
776 __dlm_insert_lockres(dlm, res);
ba2bf218 777 dlm_lockres_grab_inflight_ref(dlm, res);
6714d8e8
KH		 778 spin_unlock(&res->spinlock);
779 spin_unlock(&dlm->spinlock);
780 /* lockres still marked IN_PROGRESS */
781 goto wake_waiters;
782 }
783
784 /* check master list to see if another node has started mastering it */
785 spin_lock(&dlm->master_lock);
786
787 /* if we found a block, wait for lock to be mastered by another node */
788 blocked = dlm_find_mle(dlm, &mle, (char *)lockid, namelen);
789 if (blocked) {
ba2bf218 790 int mig;
6714d8e8
KH		 791 if (mle->type == DLM_MLE_MASTER) {
792 mlog(ML_ERROR, "master entry for nonexistent lock!\n");
793 BUG();
ba2bf218
KH		 794 }
795 mig = (mle->type == DLM_MLE_MIGRATION);
796 /* if there is a migration in progress, let the migration
797 * finish before continuing. we can wait for the absence
798 * of the MIGRATION mle: either the migrate finished or
799 * one of the nodes died and the mle was cleaned up.
800 * if there is a BLOCK here, but it already has a master
801 * set, we are too late. the master does not have a ref
802 * for us in the refmap. detach the mle and drop it.
803 * either way, go back to the top and start over. */
804 if (mig || mle->master != O2NM_MAX_NODES) {
805 BUG_ON(mig && mle->master == dlm->node_num);
806 /* we arrived too late. the master does not
807 * have a ref for us. retry. */
808 mlog(0, "%s:%.*s: late on %s\n",
809 dlm->name, namelen, lockid,
810 mig ? "MIGRATION" : "BLOCK");
6714d8e8 811 spin_unlock(&dlm->master_lock);
6714d8e8
KH		 812 spin_unlock(&dlm->spinlock);
813
814 /* master is known, detach */
ba2bf218
KH		 815 if (!mig)
816 dlm_mle_detach_hb_events(dlm, mle);
6714d8e8
KH		 817 dlm_put_mle(mle);
818 mle = NULL;
25985edc 819 /* this is lame, but we can't wait on either
ba2bf218
KH		 820 * the mle or lockres waitqueue here */
821 if (mig)
822 msleep(100);
823 goto lookup;
6714d8e8
KH		 824 }
825 } else {
826 /* go ahead and try to master lock on this node */
827 mle = alloc_mle;
828 /* make sure this does not get freed below */
829 alloc_mle = NULL;
830 dlm_init_mle(mle, DLM_MLE_MASTER, dlm, res, NULL, 0);
831 set_bit(dlm->node_num, mle->maybe_map);
1c084577 832 __dlm_insert_mle(dlm, mle);
c03872f5
KH		 833
834 /* still holding the dlm spinlock, check the recovery map
2bd63216 835 * to see if there are any nodes that still need to be
c03872f5
KH		 836 * considered. these will not appear in the mle nodemap
837 * but they might own this lockres. wait on them. */
838 bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0);
839 if (bit < O2NM_MAX_NODES) {
8decab3c
SM		 840 mlog(0, "%s: res %.*s, At least one node (%d) "
841 "to recover before lock mastery can begin\n",
c03872f5
KH		 842 dlm->name, namelen, (char *)lockid, bit);
843 wait_on_recovery = 1;
844 }
6714d8e8
KH		 845 }
846
847 /* at this point there is either a DLM_MLE_BLOCK or a
848 * DLM_MLE_MASTER on the master list, so it's safe to add the
849 * lockres to the hashtable. anyone who finds the lock will
850 * still have to wait on the IN_PROGRESS. */
851
852 /* finally add the lockres to its hash bucket */
853 __dlm_insert_lockres(dlm, res);
8d400b81 854
ff0a522e 855 /* Grab inflight ref to pin the resource */
8d400b81
SM		 856 spin_lock(&res->spinlock);
857 dlm_lockres_grab_inflight_ref(dlm, res);
858 spin_unlock(&res->spinlock);
ba2bf218 859
6714d8e8
KH		 860 /* get an extra ref on the mle in case this is a BLOCK
861 * if so, the creator of the BLOCK may try to put the last
862 * ref at this time in the assert master handler, so we
863 * need an extra one to keep from a bad ptr deref. */
a2bf0477 864 dlm_get_mle_inuse(mle);
6714d8e8
KH		 865 spin_unlock(&dlm->master_lock);
866 spin_unlock(&dlm->spinlock);
867
e7e69eb3 868redo_request:
c03872f5
KH		 869 while (wait_on_recovery) {
870 /* any cluster changes that occurred after dropping the
871 * dlm spinlock would be detectable be a change on the mle,
872 * so we only need to clear out the recovery map once. */
873 if (dlm_is_recovery_lock(lockid, namelen)) {
8decab3c
SM		 874 mlog(0, "%s: Recovery map is not empty, but must "
875 "master $RECOVERY lock now\n", dlm->name);
c03872f5
KH		 876 if (!dlm_pre_master_reco_lockres(dlm, res))
877 wait_on_recovery = 0;
878 else {
879 mlog(0, "%s: waiting 500ms for heartbeat state "
880 "change\n", dlm->name);
881 msleep(500);
882 }
883 continue;
2bd63216 884 }
c03872f5
KH		 885
886 dlm_kick_recovery_thread(dlm);
aa087b84 887 msleep(1000);
c03872f5
KH		 888 dlm_wait_for_recovery(dlm);
889
890 spin_lock(&dlm->spinlock);
891 bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0);
892 if (bit < O2NM_MAX_NODES) {
8decab3c
SM		 893 mlog(0, "%s: res %.*s, At least one node (%d) "
894 "to recover before lock mastery can begin\n",
c03872f5
KH		 895 dlm->name, namelen, (char *)lockid, bit);
896 wait_on_recovery = 1;
897 } else
898 wait_on_recovery = 0;
899 spin_unlock(&dlm->spinlock);
b7084ab5
KH		 900
901 if (wait_on_recovery)
902 dlm_wait_for_node_recovery(dlm, bit, 10000);
c03872f5
KH		 903 }
904
6714d8e8
KH		 905 /* must wait for lock to be mastered elsewhere */
906 if (blocked)
907 goto wait;
908
6714d8e8
KH		 909 ret = -EINVAL;
910 dlm_node_iter_init(mle->vote_map, &iter);
911 while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
ba2bf218 912 ret = dlm_do_master_request(res, mle, nodenum);
6714d8e8
KH		 913 if (ret < 0)
914 mlog_errno(ret);
915 if (mle->master != O2NM_MAX_NODES) {
916 /* found a master ! */
9c6510a5
KH		 917 if (mle->master <= nodenum)
918 break;
919 /* if our master request has not reached the master
920 * yet, keep going until it does. this is how the
921 * master will know that asserts are needed back to
922 * the lower nodes. */
8decab3c
SM		 923 mlog(0, "%s: res %.*s, Requests only up to %u but "
924 "master is %u, keep going\n", dlm->name, namelen,
9c6510a5 925 lockid, nodenum, mle->master);
6714d8e8
KH		 926 }
927 }
928
929wait:
930 /* keep going until the response map includes all nodes */
931 ret = dlm_wait_for_lock_mastery(dlm, res, mle, &blocked);
932 if (ret < 0) {
e7e69eb3 933 wait_on_recovery = 1;
8decab3c
SM		 934 mlog(0, "%s: res %.*s, Node map changed, redo the master "
935 "request now, blocked=%d\n", dlm->name, res->lockname.len,
6714d8e8
KH		 936 res->lockname.name, blocked);
937 if (++tries > 20) {
8decab3c
SM		 938 mlog(ML_ERROR, "%s: res %.*s, Spinning on "
939 "dlm_wait_for_lock_mastery, blocked = %d\n",
2bd63216 940 dlm->name, res->lockname.len,
6714d8e8
KH		 941 res->lockname.name, blocked);
942 dlm_print_one_lock_resource(res);
8a9343fa 943 dlm_print_one_mle(mle);
6714d8e8
KH		 944 tries = 0;
945 }
946 goto redo_request;
947 }
948
8decab3c
SM		 949 mlog(0, "%s: res %.*s, Mastered by %u\n", dlm->name, res->lockname.len,
950 res->lockname.name, res->owner);
6714d8e8
KH		 951 /* make sure we never continue without this */
952 BUG_ON(res->owner == O2NM_MAX_NODES);
953
954 /* master is known, detach if not already detached */
955 dlm_mle_detach_hb_events(dlm, mle);
956 dlm_put_mle(mle);
957 /* put the extra ref */
a2bf0477 958 dlm_put_mle_inuse(mle);
6714d8e8
KH		 959
960wake_waiters:
961 spin_lock(&res->spinlock);
962 res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
963 spin_unlock(&res->spinlock);
964 wake_up(&res->wq);
965
966leave:
967 /* need to free the unused mle */
968 if (alloc_mle)
969 kmem_cache_free(dlm_mle_cache, alloc_mle);
970
971 return res;
972}
973
974
975#define DLM_MASTERY_TIMEOUT_MS 5000
976
977static int dlm_wait_for_lock_mastery(struct dlm_ctxt *dlm,
978 struct dlm_lock_resource *res,
979 struct dlm_master_list_entry *mle,
980 int *blocked)
981{
982 u8 m;
983 int ret, bit;
984 int map_changed, voting_done;
985 int assert, sleep;
986
987recheck:
988 ret = 0;
989 assert = 0;
990
991 /* check if another node has already become the owner */
992 spin_lock(&res->spinlock);
993 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
9c6510a5
KH		 994 mlog(0, "%s:%.*s: owner is suddenly %u\n", dlm->name,
995 res->lockname.len, res->lockname.name, res->owner);
6714d8e8 996 spin_unlock(&res->spinlock);
9c6510a5
KH		 997 /* this will cause the master to re-assert across
998 * the whole cluster, freeing up mles */
588e0090 999 if (res->owner != dlm->node_num) {
ba2bf218 1000 ret = dlm_do_master_request(res, mle, res->owner);
588e0090
KH		 1001 if (ret < 0) {
1002 /* give recovery a chance to run */
1003 mlog(ML_ERROR, "link to %u went down?: %d\n", res->owner, ret);
1004 msleep(500);
1005 goto recheck;
1006 }
9c6510a5
KH		 1007 }
1008 ret = 0;
6714d8e8
KH		 1009 goto leave;
1010 }
1011 spin_unlock(&res->spinlock);
1012
1013 spin_lock(&mle->spinlock);
1014 m = mle->master;
1015 map_changed = (memcmp(mle->vote_map, mle->node_map,
1016 sizeof(mle->vote_map)) != 0);
1017 voting_done = (memcmp(mle->vote_map, mle->response_map,
1018 sizeof(mle->vote_map)) == 0);
1019
1020 /* restart if we hit any errors */
1021 if (map_changed) {
1022 int b;
1023 mlog(0, "%s: %.*s: node map changed, restarting\n",
1024 dlm->name, res->lockname.len, res->lockname.name);
1025 ret = dlm_restart_lock_mastery(dlm, res, mle, *blocked);
1026 b = (mle->type == DLM_MLE_BLOCK);
1027 if ((*blocked && !b) || (!*blocked && b)) {
2bd63216 1028 mlog(0, "%s:%.*s: status change: old=%d new=%d\n",
6714d8e8
KH		 1029 dlm->name, res->lockname.len, res->lockname.name,
1030 *blocked, b);
1031 *blocked = b;
1032 }
1033 spin_unlock(&mle->spinlock);
1034 if (ret < 0) {
1035 mlog_errno(ret);
1036 goto leave;
1037 }
1038 mlog(0, "%s:%.*s: restart lock mastery succeeded, "
1039 "rechecking now\n", dlm->name, res->lockname.len,
1040 res->lockname.name);
1041 goto recheck;
aa852354
KH		 1042 } else {
1043 if (!voting_done) {
1044 mlog(0, "map not changed and voting not done "
1045 "for %s:%.*s\n", dlm->name, res->lockname.len,
1046 res->lockname.name);
1047 }
6714d8e8
KH		 1048 }
1049
1050 if (m != O2NM_MAX_NODES) {
1051 /* another node has done an assert!
1052 * all done! */
1053 sleep = 0;
1054 } else {
1055 sleep = 1;
1056 /* have all nodes responded? */
1057 if (voting_done && !*blocked) {
1058 bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0);
1059 if (dlm->node_num <= bit) {
1060 /* my node number is lowest.
1061 * now tell other nodes that I am
1062 * mastering this. */
1063 mle->master = dlm->node_num;
ba2bf218
KH		 1064 /* ref was grabbed in get_lock_resource
1065 * will be dropped in dlmlock_master */
6714d8e8
KH		 1066 assert = 1;
1067 sleep = 0;
1068 }
1069 /* if voting is done, but we have not received
1070 * an assert master yet, we must sleep */
1071 }
1072 }
1073
1074 spin_unlock(&mle->spinlock);
1075
1076 /* sleep if we haven't finished voting yet */
1077 if (sleep) {
1078 unsigned long timeo = msecs_to_jiffies(DLM_MASTERY_TIMEOUT_MS);
1079
1080 /*
1081 if (atomic_read(&mle->mle_refs.refcount) < 2)
1082 mlog(ML_ERROR, "mle (%p) refs=%d, name=%.*s\n", mle,
1083 atomic_read(&mle->mle_refs.refcount),
1084 res->lockname.len, res->lockname.name);
1085 */
1086 atomic_set(&mle->woken, 0);
1087 (void)wait_event_timeout(mle->wq,
1088 (atomic_read(&mle->woken) == 1),
1089 timeo);
1090 if (res->owner == O2NM_MAX_NODES) {
ba2bf218
KH		 1091 mlog(0, "%s:%.*s: waiting again\n", dlm->name,
1092 res->lockname.len, res->lockname.name);
6714d8e8
KH		 1093 goto recheck;
1094 }
1095 mlog(0, "done waiting, master is %u\n", res->owner);
1096 ret = 0;
1097 goto leave;
1098 }
1099
1100 ret = 0; /* done */
1101 if (assert) {
1102 m = dlm->node_num;
1103 mlog(0, "about to master %.*s here, this=%u\n",
1104 res->lockname.len, res->lockname.name, m);
ba2bf218 1105 ret = dlm_do_assert_master(dlm, res, mle->vote_map, 0);
6714d8e8
KH		 1106 if (ret) {
1107 /* This is a failure in the network path,
1108 * not in the response to the assert_master
1109 * (any nonzero response is a BUG on this node).
1110 * Most likely a socket just got disconnected
1111 * due to node death. */
1112 mlog_errno(ret);
1113 }
1114 /* no longer need to restart lock mastery.
1115 * all living nodes have been contacted. */
1116 ret = 0;
1117 }
1118
1119 /* set the lockres owner */
1120 spin_lock(&res->spinlock);
ba2bf218
KH		 1121 /* mastery reference obtained either during
1122 * assert_master_handler or in get_lock_resource */
6714d8e8
KH		 1123 dlm_change_lockres_owner(dlm, res, m);
1124 spin_unlock(&res->spinlock);
1125
1126leave:
1127 return ret;
1128}
1129
1130struct dlm_bitmap_diff_iter
1131{
1132 int curnode;
1133 unsigned long *orig_bm;
1134 unsigned long *cur_bm;
1135 unsigned long diff_bm[BITS_TO_LONGS(O2NM_MAX_NODES)];
1136};
1137
1138enum dlm_node_state_change
1139{
1140 NODE_DOWN = -1,
1141 NODE_NO_CHANGE = 0,
1142 NODE_UP
1143};
1144
1145static void dlm_bitmap_diff_iter_init(struct dlm_bitmap_diff_iter *iter,
1146 unsigned long *orig_bm,
1147 unsigned long *cur_bm)
1148{
1149 unsigned long p1, p2;
1150 int i;
1151
1152 iter->curnode = -1;
1153 iter->orig_bm = orig_bm;
1154 iter->cur_bm = cur_bm;
1155
1156 for (i = 0; i < BITS_TO_LONGS(O2NM_MAX_NODES); i++) {
1157 p1 = *(iter->orig_bm + i);
1158 p2 = *(iter->cur_bm + i);
1159 iter->diff_bm[i] = (p1 & ~p2) | (p2 & ~p1);
1160 }
1161}
1162
1163static int dlm_bitmap_diff_iter_next(struct dlm_bitmap_diff_iter *iter,
1164 enum dlm_node_state_change *state)
1165{
1166 int bit;
1167
1168 if (iter->curnode >= O2NM_MAX_NODES)
1169 return -ENOENT;
1170
1171 bit = find_next_bit(iter->diff_bm, O2NM_MAX_NODES,
1172 iter->curnode+1);
1173 if (bit >= O2NM_MAX_NODES) {
1174 iter->curnode = O2NM_MAX_NODES;
1175 return -ENOENT;
1176 }
1177
1178 /* if it was there in the original then this node died */
1179 if (test_bit(bit, iter->orig_bm))
1180 *state = NODE_DOWN;
1181 else
1182 *state = NODE_UP;
1183
1184 iter->curnode = bit;
1185 return bit;
1186}
1187
1188
1189static int dlm_restart_lock_mastery(struct dlm_ctxt *dlm,
1190 struct dlm_lock_resource *res,
1191 struct dlm_master_list_entry *mle,
1192 int blocked)
1193{
1194 struct dlm_bitmap_diff_iter bdi;
1195 enum dlm_node_state_change sc;
1196 int node;
1197 int ret = 0;
1198
1199 mlog(0, "something happened such that the "
1200 "master process may need to be restarted!\n");
1201
1202 assert_spin_locked(&mle->spinlock);
1203
1204 dlm_bitmap_diff_iter_init(&bdi, mle->vote_map, mle->node_map);
1205 node = dlm_bitmap_diff_iter_next(&bdi, &sc);
1206 while (node >= 0) {
1207 if (sc == NODE_UP) {
e2faea4c
KH		 1208 /* a node came up. clear any old vote from
1209 * the response map and set it in the vote map
1210 * then restart the mastery. */
1211 mlog(ML_NOTICE, "node %d up while restarting\n", node);
6714d8e8
KH		 1212
1213 /* redo the master request, but only for the new node */
1214 mlog(0, "sending request to new node\n");
1215 clear_bit(node, mle->response_map);
1216 set_bit(node, mle->vote_map);
1217 } else {
1218 mlog(ML_ERROR, "node down! %d\n", node);
6714d8e8
KH		 1219 if (blocked) {
1220 int lowest = find_next_bit(mle->maybe_map,
1221 O2NM_MAX_NODES, 0);
1222
1223 /* act like it was never there */
1224 clear_bit(node, mle->maybe_map);
1225
e7e69eb3
KH		 1226 if (node == lowest) {
1227 mlog(0, "expected master %u died"
1228 " while this node was blocked "
1229 "waiting on it!\n", node);
1230 lowest = find_next_bit(mle->maybe_map,
1231 O2NM_MAX_NODES,
1232 lowest+1);
1233 if (lowest < O2NM_MAX_NODES) {
1234 mlog(0, "%s:%.*s:still "
1235 "blocked. waiting on %u "
1236 "now\n", dlm->name,
1237 res->lockname.len,
1238 res->lockname.name,
1239 lowest);
1240 } else {
1241 /* mle is an MLE_BLOCK, but
1242 * there is now nothing left to
1243 * block on. we need to return
1244 * all the way back out and try
1245 * again with an MLE_MASTER.
1246 * dlm_do_local_recovery_cleanup
1247 * has already run, so the mle
1248 * refcount is ok */
1249 mlog(0, "%s:%.*s: no "
1250 "longer blocking. try to "
1251 "master this here\n",
1252 dlm->name,
1253 res->lockname.len,
1254 res->lockname.name);
1255 mle->type = DLM_MLE_MASTER;
7141514b 1256 mle->mleres = res;
e7e69eb3 1257 }
6714d8e8 1258 }
6714d8e8
KH		 1259 }
1260
e7e69eb3
KH		 1261 /* now blank out everything, as if we had never
1262 * contacted anyone */
1263 memset(mle->maybe_map, 0, sizeof(mle->maybe_map));
1264 memset(mle->response_map, 0, sizeof(mle->response_map));
1265 /* reset the vote_map to the current node_map */
1266 memcpy(mle->vote_map, mle->node_map,
1267 sizeof(mle->node_map));
1268 /* put myself into the maybe map */
1269 if (mle->type != DLM_MLE_BLOCK)
1270 set_bit(dlm->node_num, mle->maybe_map);
6714d8e8
KH		 1271 }
1272 ret = -EAGAIN;
6714d8e8
KH		 1273 node = dlm_bitmap_diff_iter_next(&bdi, &sc);
1274 }
1275 return ret;
1276}
1277
1278
1279/*
1280 * DLM_MASTER_REQUEST_MSG
1281 *
1282 * returns: 0 on success,
1283 * -errno on a network error
1284 *
1285 * on error, the caller should assume the target node is "dead"
1286 *
1287 */
1288
ba2bf218
KH		 1289static int dlm_do_master_request(struct dlm_lock_resource *res,
1290 struct dlm_master_list_entry *mle, int to)
6714d8e8
KH		 1291{
1292 struct dlm_ctxt *dlm = mle->dlm;
1293 struct dlm_master_request request;
1294 int ret, response=0, resend;
1295
1296 memset(&request, 0, sizeof(request));
1297 request.node_idx = dlm->node_num;
1298
1299 BUG_ON(mle->type == DLM_MLE_MIGRATION);
1300
7141514b
SM		 1301 request.namelen = (u8)mle->mnamelen;
1302 memcpy(request.name, mle->mname, request.namelen);
6714d8e8
KH		 1303
1304again:
1305 ret = o2net_send_message(DLM_MASTER_REQUEST_MSG, dlm->key, &request,
1306 sizeof(request), to, &response);
1307 if (ret < 0) {
1308 if (ret == -ESRCH) {
1309 /* should never happen */
1310 mlog(ML_ERROR, "TCP stack not ready!\n");
1311 BUG();
1312 } else if (ret == -EINVAL) {
1313 mlog(ML_ERROR, "bad args passed to o2net!\n");
1314 BUG();
1315 } else if (ret == -ENOMEM) {
1316 mlog(ML_ERROR, "out of memory while trying to send "
1317 "network message! retrying\n");
1318 /* this is totally crude */
1319 msleep(50);
1320 goto again;
1321 } else if (!dlm_is_host_down(ret)) {
1322 /* not a network error. bad. */
1323 mlog_errno(ret);
1324 mlog(ML_ERROR, "unhandled error!");
1325 BUG();
1326 }
1327 /* all other errors should be network errors,
1328 * and likely indicate node death */
1329 mlog(ML_ERROR, "link to %d went down!\n", to);
1330 goto out;
1331 }
1332
1333 ret = 0;
1334 resend = 0;
1335 spin_lock(&mle->spinlock);
1336 switch (response) {
1337 case DLM_MASTER_RESP_YES:
1338 set_bit(to, mle->response_map);
1339 mlog(0, "node %u is the master, response=YES\n", to);
ba2bf218
KH		 1340 mlog(0, "%s:%.*s: master node %u now knows I have a "
1341 "reference\n", dlm->name, res->lockname.len,
1342 res->lockname.name, to);
6714d8e8
KH		 1343 mle->master = to;
1344 break;
1345 case DLM_MASTER_RESP_NO:
1346 mlog(0, "node %u not master, response=NO\n", to);
1347 set_bit(to, mle->response_map);
1348 break;
1349 case DLM_MASTER_RESP_MAYBE:
1350 mlog(0, "node %u not master, response=MAYBE\n", to);
1351 set_bit(to, mle->response_map);
1352 set_bit(to, mle->maybe_map);
1353 break;
1354 case DLM_MASTER_RESP_ERROR:
1355 mlog(0, "node %u hit an error, resending\n", to);
1356 resend = 1;
1357 response = 0;
1358 break;
1359 default:
1360 mlog(ML_ERROR, "bad response! %u\n", response);
1361 BUG();
1362 }
1363 spin_unlock(&mle->spinlock);
1364 if (resend) {
1365 /* this is also totally crude */
1366 msleep(50);
1367 goto again;
1368 }
1369
1370out:
1371 return ret;
1372}
1373
1374/*
1375 * locks that can be taken here:
1376 * dlm->spinlock
1377 * res->spinlock
1378 * mle->spinlock
1379 * dlm->master_list
1380 *
1381 * if possible, TRIM THIS DOWN!!!
1382 */
d74c9803
KH		 1383int dlm_master_request_handler(struct o2net_msg *msg, u32 len, void *data,
1384 void **ret_data)
6714d8e8
KH		 1385{
1386 u8 response = DLM_MASTER_RESP_MAYBE;
1387 struct dlm_ctxt *dlm = data;
9c6510a5 1388 struct dlm_lock_resource *res = NULL;
6714d8e8
KH		 1389 struct dlm_master_request *request = (struct dlm_master_request *) msg->buf;
1390 struct dlm_master_list_entry *mle = NULL, *tmpmle = NULL;
1391 char *name;
a3d33291 1392 unsigned int namelen, hash;
6714d8e8
KH		 1393 int found, ret;
1394 int set_maybe;
9c6510a5 1395 int dispatch_assert = 0;
6714d8e8
KH		 1396
1397 if (!dlm_grab(dlm))
1398 return DLM_MASTER_RESP_NO;
1399
1400 if (!dlm_domain_fully_joined(dlm)) {
1401 response = DLM_MASTER_RESP_NO;
1402 goto send_response;
1403 }
1404
1405 name = request->name;
1406 namelen = request->namelen;
a3d33291 1407 hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 1408
1409 if (namelen > DLM_LOCKID_NAME_MAX) {
1410 response = DLM_IVBUFLEN;
1411 goto send_response;
1412 }
1413
1414way_up_top:
1415 spin_lock(&dlm->spinlock);
a3d33291 1416 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
6714d8e8
KH		 1417 if (res) {
1418 spin_unlock(&dlm->spinlock);
1419
1420 /* take care of the easy cases up front */
1421 spin_lock(&res->spinlock);
1cd04dbe
KH		 1422 if (res->state & (DLM_LOCK_RES_RECOVERING|
1423 DLM_LOCK_RES_MIGRATING)) {
6714d8e8
KH		 1424 spin_unlock(&res->spinlock);
1425 mlog(0, "returning DLM_MASTER_RESP_ERROR since res is "
1cd04dbe 1426 "being recovered/migrated\n");
6714d8e8
KH		 1427 response = DLM_MASTER_RESP_ERROR;
1428 if (mle)
1429 kmem_cache_free(dlm_mle_cache, mle);
1430 goto send_response;
1431 }
1432
1433 if (res->owner == dlm->node_num) {
8d400b81 1434 dlm_lockres_set_refmap_bit(dlm, res, request->node_idx);
6714d8e8 1435 spin_unlock(&res->spinlock);
6714d8e8
KH		 1436 response = DLM_MASTER_RESP_YES;
1437 if (mle)
1438 kmem_cache_free(dlm_mle_cache, mle);
1439
1440 /* this node is the owner.
1441 * there is some extra work that needs to
1442 * happen now. the requesting node has
1443 * caused all nodes up to this one to
1444 * create mles. this node now needs to
1445 * go back and clean those up. */
9c6510a5 1446 dispatch_assert = 1;
6714d8e8
KH		 1447 goto send_response;
1448 } else if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
1449 spin_unlock(&res->spinlock);
1450 // mlog(0, "node %u is the master\n", res->owner);
1451 response = DLM_MASTER_RESP_NO;
1452 if (mle)
1453 kmem_cache_free(dlm_mle_cache, mle);
1454 goto send_response;
1455 }
1456
1457 /* ok, there is no owner. either this node is
1458 * being blocked, or it is actively trying to
1459 * master this lock. */
1460 if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) {
1461 mlog(ML_ERROR, "lock with no owner should be "
1462 "in-progress!\n");
1463 BUG();
1464 }
1465
1466 // mlog(0, "lockres is in progress...\n");
1467 spin_lock(&dlm->master_lock);
1468 found = dlm_find_mle(dlm, &tmpmle, name, namelen);
1469 if (!found) {
1470 mlog(ML_ERROR, "no mle found for this lock!\n");
1471 BUG();
1472 }
1473 set_maybe = 1;
1474 spin_lock(&tmpmle->spinlock);
1475 if (tmpmle->type == DLM_MLE_BLOCK) {
1476 // mlog(0, "this node is waiting for "
1477 // "lockres to be mastered\n");
1478 response = DLM_MASTER_RESP_NO;
1479 } else if (tmpmle->type == DLM_MLE_MIGRATION) {
1480 mlog(0, "node %u is master, but trying to migrate to "
1481 "node %u.\n", tmpmle->master, tmpmle->new_master);
1482 if (tmpmle->master == dlm->node_num) {
6714d8e8
KH		 1483 mlog(ML_ERROR, "no owner on lockres, but this "
1484 "node is trying to migrate it to %u?!\n",
1485 tmpmle->new_master);
1486 BUG();
1487 } else {
1488 /* the real master can respond on its own */
1489 response = DLM_MASTER_RESP_NO;
1490 }
1491 } else if (tmpmle->master != DLM_LOCK_RES_OWNER_UNKNOWN) {
1492 set_maybe = 0;
9c6510a5 1493 if (tmpmle->master == dlm->node_num) {
6714d8e8 1494 response = DLM_MASTER_RESP_YES;
9c6510a5
KH		 1495 /* this node will be the owner.
1496 * go back and clean the mles on any
1497 * other nodes */
1498 dispatch_assert = 1;
8d400b81
SM		 1499 dlm_lockres_set_refmap_bit(dlm, res,
1500 request->node_idx);
9c6510a5 1501 } else
6714d8e8
KH		 1502 response = DLM_MASTER_RESP_NO;
1503 } else {
1504 // mlog(0, "this node is attempting to "
1505 // "master lockres\n");
1506 response = DLM_MASTER_RESP_MAYBE;
1507 }
1508 if (set_maybe)
1509 set_bit(request->node_idx, tmpmle->maybe_map);
1510 spin_unlock(&tmpmle->spinlock);
1511
1512 spin_unlock(&dlm->master_lock);
1513 spin_unlock(&res->spinlock);
1514
1515 /* keep the mle attached to heartbeat events */
1516 dlm_put_mle(tmpmle);
1517 if (mle)
1518 kmem_cache_free(dlm_mle_cache, mle);
1519 goto send_response;
1520 }
1521
1522 /*
1523 * lockres doesn't exist on this node
1524 * if there is an MLE_BLOCK, return NO
1525 * if there is an MLE_MASTER, return MAYBE
1526 * otherwise, add an MLE_BLOCK, return NO
1527 */
1528 spin_lock(&dlm->master_lock);
1529 found = dlm_find_mle(dlm, &tmpmle, name, namelen);
1530 if (!found) {
1531 /* this lockid has never been seen on this node yet */
1532 // mlog(0, "no mle found\n");
1533 if (!mle) {
1534 spin_unlock(&dlm->master_lock);
1535 spin_unlock(&dlm->spinlock);
1536
3914ed0c 1537 mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
6714d8e8 1538 if (!mle) {
6714d8e8 1539 response = DLM_MASTER_RESP_ERROR;
9c6510a5 1540 mlog_errno(-ENOMEM);
6714d8e8
KH		 1541 goto send_response;
1542 }
6714d8e8
KH		 1543 goto way_up_top;
1544 }
1545
1546 // mlog(0, "this is second time thru, already allocated, "
1547 // "add the block.\n");
41b8c8a1 1548 dlm_init_mle(mle, DLM_MLE_BLOCK, dlm, NULL, name, namelen);
6714d8e8 1549 set_bit(request->node_idx, mle->maybe_map);
1c084577 1550 __dlm_insert_mle(dlm, mle);
6714d8e8
KH		 1551 response = DLM_MASTER_RESP_NO;
1552 } else {
1553 // mlog(0, "mle was found\n");
1554 set_maybe = 1;
1555 spin_lock(&tmpmle->spinlock);
9c6510a5
KH		 1556 if (tmpmle->master == dlm->node_num) {
1557 mlog(ML_ERROR, "no lockres, but an mle with this node as master!\n");
1558 BUG();
1559 }
6714d8e8
KH		 1560 if (tmpmle->type == DLM_MLE_BLOCK)
1561 response = DLM_MASTER_RESP_NO;
1562 else if (tmpmle->type == DLM_MLE_MIGRATION) {
1563 mlog(0, "migration mle was found (%u->%u)\n",
1564 tmpmle->master, tmpmle->new_master);
6714d8e8
KH		 1565 /* real master can respond on its own */
1566 response = DLM_MASTER_RESP_NO;
9c6510a5
KH		 1567 } else
1568 response = DLM_MASTER_RESP_MAYBE;
6714d8e8
KH		 1569 if (set_maybe)
1570 set_bit(request->node_idx, tmpmle->maybe_map);
1571 spin_unlock(&tmpmle->spinlock);
1572 }
1573 spin_unlock(&dlm->master_lock);
1574 spin_unlock(&dlm->spinlock);
1575
1576 if (found) {
1577 /* keep the mle attached to heartbeat events */
1578 dlm_put_mle(tmpmle);
1579 }
1580send_response:
b31cfc02
SM		 1581 /*
1582 * __dlm_lookup_lockres() grabbed a reference to this lockres.
1583 * The reference is released by dlm_assert_master_worker() under
1584 * the call to dlm_dispatch_assert_master(). If
1585 * dlm_assert_master_worker() isn't called, we drop it here.
1586 */
9c6510a5
KH		 1587 if (dispatch_assert) {
1588 if (response != DLM_MASTER_RESP_YES)
1589 mlog(ML_ERROR, "invalid response %d\n", response);
1590 if (!res) {
1591 mlog(ML_ERROR, "bad lockres while trying to assert!\n");
1592 BUG();
1593 }
1594 mlog(0, "%u is the owner of %.*s, cleaning everyone else\n",
1595 dlm->node_num, res->lockname.len, res->lockname.name);
2bd63216 1596 ret = dlm_dispatch_assert_master(dlm, res, 0, request->node_idx,
9c6510a5
KH		 1597 DLM_ASSERT_MASTER_MLE_CLEANUP);
1598 if (ret < 0) {
1599 mlog(ML_ERROR, "failed to dispatch assert master work\n");
1600 response = DLM_MASTER_RESP_ERROR;
b31cfc02 1601 dlm_lockres_put(res);
9c6510a5 1602 }
b31cfc02
SM		 1603 } else {
1604 if (res)
1605 dlm_lockres_put(res);
9c6510a5
KH		 1606 }
1607
6714d8e8
KH		 1608 dlm_put(dlm);
1609 return response;
1610}
1611
1612/*
1613 * DLM_ASSERT_MASTER_MSG
1614 */
1615
1616
1617/*
1618 * NOTE: this can be used for debugging
1619 * can periodically run all locks owned by this node
1620 * and re-assert across the cluster...
1621 */
05488bbe
AB		 1622static int dlm_do_assert_master(struct dlm_ctxt *dlm,
1623 struct dlm_lock_resource *res,
1624 void *nodemap, u32 flags)
6714d8e8
KH		 1625{
1626 struct dlm_assert_master assert;
1627 int to, tmpret;
1628 struct dlm_node_iter iter;
1629 int ret = 0;
9c6510a5 1630 int reassert;
ba2bf218
KH		 1631 const char *lockname = res->lockname.name;
1632 unsigned int namelen = res->lockname.len;
6714d8e8
KH		 1633
1634 BUG_ON(namelen > O2NM_MAX_NAME_LEN);
f3f85464
SM		 1635
1636 spin_lock(&res->spinlock);
1637 res->state |= DLM_LOCK_RES_SETREF_INPROG;
1638 spin_unlock(&res->spinlock);
1639
9c6510a5
KH		 1640again:
1641 reassert = 0;
6714d8e8
KH		 1642
1643 /* note that if this nodemap is empty, it returns 0 */
1644 dlm_node_iter_init(nodemap, &iter);
1645 while ((to = dlm_node_iter_next(&iter)) >= 0) {
1646 int r = 0;
a9ee4c8a
KH		 1647 struct dlm_master_list_entry *mle = NULL;
1648
6714d8e8
KH		 1649 mlog(0, "sending assert master to %d (%.*s)\n", to,
1650 namelen, lockname);
1651 memset(&assert, 0, sizeof(assert));
1652 assert.node_idx = dlm->node_num;
1653 assert.namelen = namelen;
1654 memcpy(assert.name, lockname, namelen);
1655 assert.flags = cpu_to_be32(flags);
1656
1657 tmpret = o2net_send_message(DLM_ASSERT_MASTER_MSG, dlm->key,
1658 &assert, sizeof(assert), to, &r);
1659 if (tmpret < 0) {
a5196ec5
WW		 1660 mlog(ML_ERROR, "Error %d when sending message %u (key "
1661 "0x%x) to node %u\n", tmpret,
1662 DLM_ASSERT_MASTER_MSG, dlm->key, to);
6714d8e8 1663 if (!dlm_is_host_down(tmpret)) {
3b3b84a8 1664 mlog(ML_ERROR, "unhandled error=%d!\n", tmpret);
6714d8e8
KH		 1665 BUG();
1666 }
1667 /* a node died. finish out the rest of the nodes. */
3b3b84a8 1668 mlog(0, "link to %d went down!\n", to);
6714d8e8
KH		 1669 /* any nonzero status return will do */
1670 ret = tmpret;
ba2bf218 1671 r = 0;
6714d8e8
KH		 1672 } else if (r < 0) {
1673 /* ok, something horribly messed. kill thyself. */
1674 mlog(ML_ERROR,"during assert master of %.*s to %u, "
1675 "got %d.\n", namelen, lockname, to, r);
a9ee4c8a
KH		 1676 spin_lock(&dlm->spinlock);
1677 spin_lock(&dlm->master_lock);
1678 if (dlm_find_mle(dlm, &mle, (char *)lockname,
1679 namelen)) {
1680 dlm_print_one_mle(mle);
1681 __dlm_put_mle(mle);
1682 }
1683 spin_unlock(&dlm->master_lock);
1684 spin_unlock(&dlm->spinlock);
6714d8e8 1685 BUG();
ba2bf218
KH		 1686 }
1687
1688 if (r & DLM_ASSERT_RESPONSE_REASSERT &&
1689 !(r & DLM_ASSERT_RESPONSE_MASTERY_REF)) {
1690 mlog(ML_ERROR, "%.*s: very strange, "
1691 "master MLE but no lockres on %u\n",
1692 namelen, lockname, to);
1693 }
1694
1695 if (r & DLM_ASSERT_RESPONSE_REASSERT) {
9c6510a5 1696 mlog(0, "%.*s: node %u create mles on other "
2bd63216 1697 "nodes and requests a re-assert\n",
9c6510a5
KH		 1698 namelen, lockname, to);
1699 reassert = 1;
6714d8e8 1700 }
ba2bf218
KH		 1701 if (r & DLM_ASSERT_RESPONSE_MASTERY_REF) {
1702 mlog(0, "%.*s: node %u has a reference to this "
1703 "lockres, set the bit in the refmap\n",
1704 namelen, lockname, to);
1705 spin_lock(&res->spinlock);
8d400b81 1706 dlm_lockres_set_refmap_bit(dlm, res, to);
ba2bf218
KH		 1707 spin_unlock(&res->spinlock);
1708 }
6714d8e8
KH		 1709 }
1710
9c6510a5
KH		 1711 if (reassert)
1712 goto again;
1713
f3f85464
SM		 1714 spin_lock(&res->spinlock);
1715 res->state &= ~DLM_LOCK_RES_SETREF_INPROG;
1716 spin_unlock(&res->spinlock);
1717 wake_up(&res->wq);
1718
6714d8e8
KH		 1719 return ret;
1720}
1721
1722/*
1723 * locks that can be taken here:
1724 * dlm->spinlock
1725 * res->spinlock
1726 * mle->spinlock
1727 * dlm->master_list
1728 *
1729 * if possible, TRIM THIS DOWN!!!
1730 */
d74c9803
KH		 1731int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data,
1732 void **ret_data)
6714d8e8
KH		 1733{
1734 struct dlm_ctxt *dlm = data;
1735 struct dlm_master_list_entry *mle = NULL;
1736 struct dlm_assert_master *assert = (struct dlm_assert_master *)msg->buf;
1737 struct dlm_lock_resource *res = NULL;
1738 char *name;
a3d33291 1739 unsigned int namelen, hash;
6714d8e8 1740 u32 flags;
ba2bf218 1741 int master_request = 0, have_lockres_ref = 0;
9c6510a5 1742 int ret = 0;
6714d8e8
KH		 1743
1744 if (!dlm_grab(dlm))
1745 return 0;
1746
1747 name = assert->name;
1748 namelen = assert->namelen;
a3d33291 1749 hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 1750 flags = be32_to_cpu(assert->flags);
1751
1752 if (namelen > DLM_LOCKID_NAME_MAX) {
1753 mlog(ML_ERROR, "Invalid name length!");
1754 goto done;
1755 }
1756
1757 spin_lock(&dlm->spinlock);
1758
1759 if (flags)
1760 mlog(0, "assert_master with flags: %u\n", flags);
1761
1762 /* find the MLE */
1763 spin_lock(&dlm->master_lock);
1764 if (!dlm_find_mle(dlm, &mle, name, namelen)) {
1765 /* not an error, could be master just re-asserting */
1766 mlog(0, "just got an assert_master from %u, but no "
1767 "MLE for it! (%.*s)\n", assert->node_idx,
1768 namelen, name);
1769 } else {
1770 int bit = find_next_bit (mle->maybe_map, O2NM_MAX_NODES, 0);
1771 if (bit >= O2NM_MAX_NODES) {
1772 /* not necessarily an error, though less likely.
1773 * could be master just re-asserting. */
aa852354 1774 mlog(0, "no bits set in the maybe_map, but %u "
6714d8e8
KH		 1775 "is asserting! (%.*s)\n", assert->node_idx,
1776 namelen, name);
1777 } else if (bit != assert->node_idx) {
1778 if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) {
1779 mlog(0, "master %u was found, %u should "
1780 "back off\n", assert->node_idx, bit);
1781 } else {
1782 /* with the fix for bug 569, a higher node
1783 * number winning the mastery will respond
1784 * YES to mastery requests, but this node
1785 * had no way of knowing. let it pass. */
aa852354 1786 mlog(0, "%u is the lowest node, "
6714d8e8
KH		 1787 "%u is asserting. (%.*s) %u must "
1788 "have begun after %u won.\n", bit,
1789 assert->node_idx, namelen, name, bit,
1790 assert->node_idx);
1791 }
1792 }
2d1a868c
KH		 1793 if (mle->type == DLM_MLE_MIGRATION) {
1794 if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) {
1795 mlog(0, "%s:%.*s: got cleanup assert"
1796 " from %u for migration\n",
1797 dlm->name, namelen, name,
1798 assert->node_idx);
1799 } else if (!(flags & DLM_ASSERT_MASTER_FINISH_MIGRATION)) {
1800 mlog(0, "%s:%.*s: got unrelated assert"
1801 " from %u for migration, ignoring\n",
1802 dlm->name, namelen, name,
1803 assert->node_idx);
1804 __dlm_put_mle(mle);
1805 spin_unlock(&dlm->master_lock);
1806 spin_unlock(&dlm->spinlock);
1807 goto done;
2bd63216 1808 }
2d1a868c 1809 }
6714d8e8
KH		 1810 }
1811 spin_unlock(&dlm->master_lock);
1812
1813 /* ok everything checks out with the MLE
1814 * now check to see if there is a lockres */
a3d33291 1815 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
6714d8e8
KH		 1816 if (res) {
1817 spin_lock(&res->spinlock);
1818 if (res->state & DLM_LOCK_RES_RECOVERING) {
1819 mlog(ML_ERROR, "%u asserting but %.*s is "
1820 "RECOVERING!\n", assert->node_idx, namelen, name);
1821 goto kill;
1822 }
1823 if (!mle) {
dc2ed195
KH		 1824 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN &&
1825 res->owner != assert->node_idx) {
53ecd25e
SM		 1826 mlog(ML_ERROR, "DIE! Mastery assert from %u, "
1827 "but current owner is %u! (%.*s)\n",
1828 assert->node_idx, res->owner, namelen,
1829 name);
1830 __dlm_print_one_lock_resource(res);
1831 BUG();
6714d8e8
KH		 1832 }
1833 } else if (mle->type != DLM_MLE_MIGRATION) {
1834 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
1835 /* owner is just re-asserting */
1836 if (res->owner == assert->node_idx) {
1837 mlog(0, "owner %u re-asserting on "
1838 "lock %.*s\n", assert->node_idx,
1839 namelen, name);
1840 goto ok;
1841 }
1842 mlog(ML_ERROR, "got assert_master from "
1843 "node %u, but %u is the owner! "
1844 "(%.*s)\n", assert->node_idx,
1845 res->owner, namelen, name);
1846 goto kill;
1847 }
1848 if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) {
1849 mlog(ML_ERROR, "got assert from %u, but lock "
1850 "with no owner should be "
1851 "in-progress! (%.*s)\n",
1852 assert->node_idx,
1853 namelen, name);
1854 goto kill;
1855 }
1856 } else /* mle->type == DLM_MLE_MIGRATION */ {
1857 /* should only be getting an assert from new master */
1858 if (assert->node_idx != mle->new_master) {
1859 mlog(ML_ERROR, "got assert from %u, but "
1860 "new master is %u, and old master "
1861 "was %u (%.*s)\n",
1862 assert->node_idx, mle->new_master,
1863 mle->master, namelen, name);
1864 goto kill;
1865 }
1866
1867 }
1868ok:
1869 spin_unlock(&res->spinlock);
1870 }
6714d8e8
KH		 1871
1872 // mlog(0, "woo! got an assert_master from node %u!\n",
1873 // assert->node_idx);
1874 if (mle) {
9c6510a5
KH		 1875 int extra_ref = 0;
1876 int nn = -1;
a2bf0477 1877 int rr, err = 0;
2bd63216 1878
6714d8e8 1879 spin_lock(&mle->spinlock);
9c6510a5
KH		 1880 if (mle->type == DLM_MLE_BLOCK || mle->type == DLM_MLE_MIGRATION)
1881 extra_ref = 1;
1882 else {
1883 /* MASTER mle: if any bits set in the response map
1884 * then the calling node needs to re-assert to clear
1885 * up nodes that this node contacted */
2bd63216 1886 while ((nn = find_next_bit (mle->response_map, O2NM_MAX_NODES,
9c6510a5
KH		 1887 nn+1)) < O2NM_MAX_NODES) {
1888 if (nn != dlm->node_num && nn != assert->node_idx)
1889 master_request = 1;
1890 }
1891 }
6714d8e8
KH		 1892 mle->master = assert->node_idx;
1893 atomic_set(&mle->woken, 1);
1894 wake_up(&mle->wq);
1895 spin_unlock(&mle->spinlock);
1896
a2bf0477 1897 if (res) {
a6fa3640 1898 int wake = 0;
6714d8e8 1899 spin_lock(&res->spinlock);
a2bf0477
KH		 1900 if (mle->type == DLM_MLE_MIGRATION) {
1901 mlog(0, "finishing off migration of lockres %.*s, "
1902 "from %u to %u\n",
1903 res->lockname.len, res->lockname.name,
1904 dlm->node_num, mle->new_master);
1905 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 1906 wake = 1;
a2bf0477
KH		 1907 dlm_change_lockres_owner(dlm, res, mle->new_master);
1908 BUG_ON(res->state & DLM_LOCK_RES_DIRTY);
1909 } else {
1910 dlm_change_lockres_owner(dlm, res, mle->master);
1911 }
6714d8e8 1912 spin_unlock(&res->spinlock);
ba2bf218 1913 have_lockres_ref = 1;
a6fa3640
KH		 1914 if (wake)
1915 wake_up(&res->wq);
6714d8e8 1916 }
a2bf0477
KH		 1917
1918 /* master is known, detach if not already detached.
1919 * ensures that only one assert_master call will happen
1920 * on this mle. */
a2bf0477
KH		 1921 spin_lock(&dlm->master_lock);
1922
1923 rr = atomic_read(&mle->mle_refs.refcount);
1924 if (mle->inuse > 0) {
1925 if (extra_ref && rr < 3)
1926 err = 1;
1927 else if (!extra_ref && rr < 2)
1928 err = 1;
1929 } else {
1930 if (extra_ref && rr < 2)
1931 err = 1;
1932 else if (!extra_ref && rr < 1)
1933 err = 1;
1934 }
1935 if (err) {
1936 mlog(ML_ERROR, "%s:%.*s: got assert master from %u "
1937 "that will mess up this node, refs=%d, extra=%d, "
1938 "inuse=%d\n", dlm->name, namelen, name,
1939 assert->node_idx, rr, extra_ref, mle->inuse);
1940 dlm_print_one_mle(mle);
1941 }
1c084577 1942 __dlm_unlink_mle(dlm, mle);
a2bf0477
KH		 1943 __dlm_mle_detach_hb_events(dlm, mle);
1944 __dlm_put_mle(mle);
6714d8e8
KH		 1945 if (extra_ref) {
1946 /* the assert master message now balances the extra
1947 * ref given by the master / migration request message.
1948 * if this is the last put, it will be removed
1949 * from the list. */
a2bf0477
KH		 1950 __dlm_put_mle(mle);
1951 }
1952 spin_unlock(&dlm->master_lock);
a2bf0477
KH		 1953 } else if (res) {
1954 if (res->owner != assert->node_idx) {
1955 mlog(0, "assert_master from %u, but current "
1956 "owner is %u (%.*s), no mle\n", assert->node_idx,
1957 res->owner, namelen, name);
6714d8e8
KH		 1958 }
1959 }
14741472 1960 spin_unlock(&dlm->spinlock);
6714d8e8
KH		 1961
1962done:
9c6510a5 1963 ret = 0;
3b8118cf
KH		 1964 if (res) {
1965 spin_lock(&res->spinlock);
1966 res->state |= DLM_LOCK_RES_SETREF_INPROG;
1967 spin_unlock(&res->spinlock);
1968 *ret_data = (void *)res;
1969 }
6714d8e8 1970 dlm_put(dlm);
9c6510a5
KH		 1971 if (master_request) {
1972 mlog(0, "need to tell master to reassert\n");
ba2bf218
KH		 1973 /* positive. negative would shoot down the node. */
1974 ret |= DLM_ASSERT_RESPONSE_REASSERT;
1975 if (!have_lockres_ref) {
1976 mlog(ML_ERROR, "strange, got assert from %u, MASTER "
1977 "mle present here for %s:%.*s, but no lockres!\n",
1978 assert->node_idx, dlm->name, namelen, name);
1979 }
1980 }
1981 if (have_lockres_ref) {
1982 /* let the master know we have a reference to the lockres */
1983 ret |= DLM_ASSERT_RESPONSE_MASTERY_REF;
1984 mlog(0, "%s:%.*s: got assert from %u, need a ref\n",
1985 dlm->name, namelen, name, assert->node_idx);
9c6510a5
KH		 1986 }
1987 return ret;
6714d8e8
KH		 1988
1989kill:
1990 /* kill the caller! */
a9ee4c8a
KH		 1991 mlog(ML_ERROR, "Bad message received from another node. Dumping state "
1992 "and killing the other node now! This node is OK and can continue.\n");
1993 __dlm_print_one_lock_resource(res);
6714d8e8
KH		 1994 spin_unlock(&res->spinlock);
1995 spin_unlock(&dlm->spinlock);
2bd63216 1996 *ret_data = (void *)res;
6714d8e8
KH		 1997 dlm_put(dlm);
1998 return -EINVAL;
1999}
2000
3b8118cf
KH		 2001void dlm_assert_master_post_handler(int status, void *data, void *ret_data)
2002{
2003 struct dlm_lock_resource *res = (struct dlm_lock_resource *)ret_data;
2004
2005 if (ret_data) {
2006 spin_lock(&res->spinlock);
2007 res->state &= ~DLM_LOCK_RES_SETREF_INPROG;
2008 spin_unlock(&res->spinlock);
2009 wake_up(&res->wq);
2010 dlm_lockres_put(res);
2011 }
2012 return;
2013}
2014
6714d8e8
KH		 2015int dlm_dispatch_assert_master(struct dlm_ctxt *dlm,
2016 struct dlm_lock_resource *res,
2017 int ignore_higher, u8 request_from, u32 flags)
2018{
2019 struct dlm_work_item *item;
b24ae0b5 2020 item = kzalloc(sizeof(*item), GFP_ATOMIC);
6714d8e8
KH		 2021 if (!item)
2022 return -ENOMEM;
2023
2024
2025 /* queue up work for dlm_assert_master_worker */
2026 dlm_grab(dlm); /* get an extra ref for the work item */
2027 dlm_init_work_item(dlm, item, dlm_assert_master_worker, NULL);
2028 item->u.am.lockres = res; /* already have a ref */
2029 /* can optionally ignore node numbers higher than this node */
2030 item->u.am.ignore_higher = ignore_higher;
2031 item->u.am.request_from = request_from;
2032 item->u.am.flags = flags;
2033
2bd63216
SM		 2034 if (ignore_higher)
2035 mlog(0, "IGNORE HIGHER: %.*s\n", res->lockname.len,
9c6510a5 2036 res->lockname.name);
2bd63216 2037
6714d8e8
KH		 2038 spin_lock(&dlm->work_lock);
2039 list_add_tail(&item->list, &dlm->work_list);
2040 spin_unlock(&dlm->work_lock);
2041
3156d267 2042 queue_work(dlm->dlm_worker, &dlm->dispatched_work);
6714d8e8
KH		 2043 return 0;
2044}
2045
2046static void dlm_assert_master_worker(struct dlm_work_item *item, void *data)
2047{
2048 struct dlm_ctxt *dlm = data;
2049 int ret = 0;
2050 struct dlm_lock_resource *res;
2051 unsigned long nodemap[BITS_TO_LONGS(O2NM_MAX_NODES)];
2052 int ignore_higher;
2053 int bit;
2054 u8 request_from;
2055 u32 flags;
2056
2057 dlm = item->dlm;
2058 res = item->u.am.lockres;
2059 ignore_higher = item->u.am.ignore_higher;
2060 request_from = item->u.am.request_from;
2061 flags = item->u.am.flags;
2062
2063 spin_lock(&dlm->spinlock);
2064 memcpy(nodemap, dlm->domain_map, sizeof(nodemap));
2065 spin_unlock(&dlm->spinlock);
2066
2067 clear_bit(dlm->node_num, nodemap);
2068 if (ignore_higher) {
2069 /* if is this just to clear up mles for nodes below
2070 * this node, do not send the message to the original
2071 * caller or any node number higher than this */
2072 clear_bit(request_from, nodemap);
2073 bit = dlm->node_num;
2074 while (1) {
2075 bit = find_next_bit(nodemap, O2NM_MAX_NODES,
2076 bit+1);
2077 if (bit >= O2NM_MAX_NODES)
2078 break;
2079 clear_bit(bit, nodemap);
2080 }
2081 }
2082
36407488
KH		 2083 /*
2084 * If we're migrating this lock to someone else, we are no
2085 * longer allowed to assert out own mastery. OTOH, we need to
2086 * prevent migration from starting while we're still asserting
2087 * our dominance. The reserved ast delays migration.
2088 */
2089 spin_lock(&res->spinlock);
2090 if (res->state & DLM_LOCK_RES_MIGRATING) {
2091 mlog(0, "Someone asked us to assert mastery, but we're "
2092 "in the middle of migration. Skipping assert, "
2093 "the new master will handle that.\n");
2094 spin_unlock(&res->spinlock);
2095 goto put;
2096 } else
2097 __dlm_lockres_reserve_ast(res);
2098 spin_unlock(&res->spinlock);
2099
6714d8e8
KH		 2100 /* this call now finishes out the nodemap
2101 * even if one or more nodes die */
2102 mlog(0, "worker about to master %.*s here, this=%u\n",
2103 res->lockname.len, res->lockname.name, dlm->node_num);
ba2bf218 2104 ret = dlm_do_assert_master(dlm, res, nodemap, flags);
6714d8e8
KH		 2105 if (ret < 0) {
2106 /* no need to restart, we are done */
3b3b84a8
KH		 2107 if (!dlm_is_host_down(ret))
2108 mlog_errno(ret);
6714d8e8
KH		 2109 }
2110
36407488
KH		 2111 /* Ok, we've asserted ourselves. Let's let migration start. */
2112 dlm_lockres_release_ast(dlm, res);
2113
2114put:
6714d8e8
KH		 2115 dlm_lockres_put(res);
2116
2117 mlog(0, "finished with dlm_assert_master_worker\n");
2118}
2119
c03872f5
KH		 2120/* SPECIAL CASE for the $RECOVERY lock used by the recovery thread.
2121 * We cannot wait for node recovery to complete to begin mastering this
2122 * lockres because this lockres is used to kick off recovery! ;-)
2123 * So, do a pre-check on all living nodes to see if any of those nodes
2124 * think that $RECOVERY is currently mastered by a dead node. If so,
2125 * we wait a short time to allow that node to get notified by its own
2126 * heartbeat stack, then check again. All $RECOVERY lock resources
2bd63216 2127 * mastered by dead nodes are purged when the hearbeat callback is
c03872f5
KH		 2128 * fired, so we can know for sure that it is safe to continue once
2129 * the node returns a live node or no node. */
2130static int dlm_pre_master_reco_lockres(struct dlm_ctxt *dlm,
2131 struct dlm_lock_resource *res)
2132{
2133 struct dlm_node_iter iter;
2134 int nodenum;
2135 int ret = 0;
2136 u8 master = DLM_LOCK_RES_OWNER_UNKNOWN;
2137
2138 spin_lock(&dlm->spinlock);
2139 dlm_node_iter_init(dlm->domain_map, &iter);
2140 spin_unlock(&dlm->spinlock);
2141
2142 while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2143 /* do not send to self */
2144 if (nodenum == dlm->node_num)
2145 continue;
2146 ret = dlm_do_master_requery(dlm, res, nodenum, &master);
2147 if (ret < 0) {
2148 mlog_errno(ret);
2149 if (!dlm_is_host_down(ret))
2150 BUG();
2151 /* host is down, so answer for that node would be
2152 * DLM_LOCK_RES_OWNER_UNKNOWN. continue. */
f42a100b 2153 ret = 0;
c03872f5
KH		 2154 }
2155
2156 if (master != DLM_LOCK_RES_OWNER_UNKNOWN) {
2157 /* check to see if this master is in the recovery map */
2158 spin_lock(&dlm->spinlock);
2159 if (test_bit(master, dlm->recovery_map)) {
2160 mlog(ML_NOTICE, "%s: node %u has not seen "
2161 "node %u go down yet, and thinks the "
2162 "dead node is mastering the recovery "
2163 "lock. must wait.\n", dlm->name,
2164 nodenum, master);
2165 ret = -EAGAIN;
2166 }
2167 spin_unlock(&dlm->spinlock);
2bd63216 2168 mlog(0, "%s: reco lock master is %u\n", dlm->name,
c03872f5
KH		 2169 master);
2170 break;
2171 }
2172 }
2173 return ret;
2174}
2175
ba2bf218
KH		 2176/*
2177 * DLM_DEREF_LOCKRES_MSG
2178 */
2179
2180int dlm_drop_lockres_ref(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
2181{
2182 struct dlm_deref_lockres deref;
2183 int ret = 0, r;
2184 const char *lockname;
2185 unsigned int namelen;
2186
2187 lockname = res->lockname.name;
2188 namelen = res->lockname.len;
2189 BUG_ON(namelen > O2NM_MAX_NAME_LEN);
2190
ba2bf218
KH		 2191 memset(&deref, 0, sizeof(deref));
2192 deref.node_idx = dlm->node_num;
2193 deref.namelen = namelen;
2194 memcpy(deref.name, lockname, namelen);
2195
2196 ret = o2net_send_message(DLM_DEREF_LOCKRES_MSG, dlm->key,
2197 &deref, sizeof(deref), res->owner, &r);
2198 if (ret < 0)
8decab3c
SM		 2199 mlog(ML_ERROR, "%s: res %.*s, error %d send DEREF to node %u\n",
2200 dlm->name, namelen, lockname, ret, res->owner);
ba2bf218
KH		 2201 else if (r < 0) {
2202 /* BAD. other node says I did not have a ref. */
8decab3c
SM		 2203 mlog(ML_ERROR, "%s: res %.*s, DEREF to node %u got %d\n",
2204 dlm->name, namelen, lockname, res->owner, r);
ba2bf218
KH		 2205 dlm_print_one_lock_resource(res);
2206 BUG();
2207 }
2208 return ret;
2209}
2210
d74c9803
KH		 2211int dlm_deref_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
2212 void **ret_data)
ba2bf218
KH		 2213{
2214 struct dlm_ctxt *dlm = data;
2215 struct dlm_deref_lockres *deref = (struct dlm_deref_lockres *)msg->buf;
2216 struct dlm_lock_resource *res = NULL;
2217 char *name;
2218 unsigned int namelen;
2219 int ret = -EINVAL;
2220 u8 node;
2221 unsigned int hash;
f3f85464
SM		 2222 struct dlm_work_item *item;
2223 int cleared = 0;
2224 int dispatch = 0;
ba2bf218
KH		 2225
2226 if (!dlm_grab(dlm))
2227 return 0;
2228
2229 name = deref->name;
2230 namelen = deref->namelen;
2231 node = deref->node_idx;
2232
2233 if (namelen > DLM_LOCKID_NAME_MAX) {
2234 mlog(ML_ERROR, "Invalid name length!");
2235 goto done;
2236 }
2237 if (deref->node_idx >= O2NM_MAX_NODES) {
2238 mlog(ML_ERROR, "Invalid node number: %u\n", node);
2239 goto done;
2240 }
2241
2242 hash = dlm_lockid_hash(name, namelen);
2243
2244 spin_lock(&dlm->spinlock);
2245 res = __dlm_lookup_lockres_full(dlm, name, namelen, hash);
2246 if (!res) {
2247 spin_unlock(&dlm->spinlock);
2248 mlog(ML_ERROR, "%s:%.*s: bad lockres name\n",
2249 dlm->name, namelen, name);
2250 goto done;
2251 }
2252 spin_unlock(&dlm->spinlock);
2253
2254 spin_lock(&res->spinlock);
f3f85464
SM		 2255 if (res->state & DLM_LOCK_RES_SETREF_INPROG)
2256 dispatch = 1;
2257 else {
2258 BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF);
2259 if (test_bit(node, res->refmap)) {
8d400b81 2260 dlm_lockres_clear_refmap_bit(dlm, res, node);
f3f85464
SM		 2261 cleared = 1;
2262 }
ba2bf218
KH		 2263 }
2264 spin_unlock(&res->spinlock);
2265
f3f85464
SM		 2266 if (!dispatch) {
2267 if (cleared)
2268 dlm_lockres_calc_usage(dlm, res);
2269 else {
2270 mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref "
2271 "but it is already dropped!\n", dlm->name,
2272 res->lockname.len, res->lockname.name, node);
2af37ce8 2273 dlm_print_one_lock_resource(res);
f3f85464
SM		 2274 }
2275 ret = 0;
2276 goto done;
2277 }
2278
2279 item = kzalloc(sizeof(*item), GFP_NOFS);
2280 if (!item) {
2281 ret = -ENOMEM;
2282 mlog_errno(ret);
2283 goto done;
2284 }
2285
2286 dlm_init_work_item(dlm, item, dlm_deref_lockres_worker, NULL);
2287 item->u.dl.deref_res = res;
2288 item->u.dl.deref_node = node;
2289
2290 spin_lock(&dlm->work_lock);
2291 list_add_tail(&item->list, &dlm->work_list);
2292 spin_unlock(&dlm->work_lock);
2293
2294 queue_work(dlm->dlm_worker, &dlm->dispatched_work);
2295 return 0;
2296
ba2bf218
KH		 2297done:
2298 if (res)
2299 dlm_lockres_put(res);
2300 dlm_put(dlm);
f3f85464 2301
ba2bf218
KH		 2302 return ret;
2303}
2304
f3f85464
SM		 2305static void dlm_deref_lockres_worker(struct dlm_work_item *item, void *data)
2306{
2307 struct dlm_ctxt *dlm;
2308 struct dlm_lock_resource *res;
2309 u8 node;
2310 u8 cleared = 0;
2311
2312 dlm = item->dlm;
2313 res = item->u.dl.deref_res;
2314 node = item->u.dl.deref_node;
2315
2316 spin_lock(&res->spinlock);
2317 BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF);
2318 if (test_bit(node, res->refmap)) {
2319 __dlm_wait_on_lockres_flags(res, DLM_LOCK_RES_SETREF_INPROG);
8d400b81 2320 dlm_lockres_clear_refmap_bit(dlm, res, node);
f3f85464
SM		 2321 cleared = 1;
2322 }
2323 spin_unlock(&res->spinlock);
2324
2325 if (cleared) {
2326 mlog(0, "%s:%.*s node %u ref dropped in dispatch\n",
2327 dlm->name, res->lockname.len, res->lockname.name, node);
2328 dlm_lockres_calc_usage(dlm, res);
2329 } else {
2330 mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref "
2331 "but it is already dropped!\n", dlm->name,
2332 res->lockname.len, res->lockname.name, node);
2af37ce8 2333 dlm_print_one_lock_resource(res);
f3f85464
SM		 2334 }
2335
2336 dlm_lockres_put(res);
2337}
2338
9f62e960
SM		 2339/*
2340 * A migrateable resource is one that is :
2341 * 1. locally mastered, and,
2342 * 2. zero local locks, and,
2343 * 3. one or more non-local locks, or, one or more references
2344 * Returns 1 if yes, 0 if not.
2f5bf1f2
SM		 2345 */
2346static int dlm_is_lockres_migrateable(struct dlm_ctxt *dlm,
9f62e960 2347 struct dlm_lock_resource *res)
2f5bf1f2 2348{
9f62e960
SM		 2349 enum dlm_lockres_list idx;
2350 int nonlocal = 0, node_ref;
800deef3 2351 struct list_head *queue;
2f5bf1f2 2352 struct dlm_lock *lock;
9f62e960 2353 u64 cookie;
2f5bf1f2
SM		 2354
2355 assert_spin_locked(&res->spinlock);
2356
9f62e960
SM		 2357 if (res->owner != dlm->node_num)
2358 return 0;
2f5bf1f2 2359
9f62e960
SM		 2360 for (idx = DLM_GRANTED_LIST; idx <= DLM_BLOCKED_LIST; idx++) {
2361 queue = dlm_list_idx_to_ptr(res, idx);
800deef3 2362 list_for_each_entry(lock, queue, list) {
9f62e960
SM		 2363 if (lock->ml.node != dlm->node_num) {
2364 nonlocal++;
2365 continue;
2f5bf1f2 2366 }
9f62e960
SM		 2367 cookie = be64_to_cpu(lock->ml.cookie);
2368 mlog(0, "%s: Not migrateable res %.*s, lock %u:%llu on "
2369 "%s list\n", dlm->name, res->lockname.len,
2370 res->lockname.name,
2371 dlm_get_lock_cookie_node(cookie),
2372 dlm_get_lock_cookie_seq(cookie),
2373 dlm_list_in_text(idx));
2374 return 0;
2f5bf1f2 2375 }
2f5bf1f2
SM		 2376 }
2377
9f62e960
SM		 2378 if (!nonlocal) {
2379 node_ref = find_next_bit(res->refmap, O2NM_MAX_NODES, 0);
2380 if (node_ref >= O2NM_MAX_NODES)
2381 return 0;
2382 }
388c4bcb 2383
9f62e960
SM		 2384 mlog(0, "%s: res %.*s, Migrateable\n", dlm->name, res->lockname.len,
2385 res->lockname.name);
2f5bf1f2 2386
9f62e960 2387 return 1;
2f5bf1f2 2388}
6714d8e8
KH		 2389
2390/*
2391 * DLM_MIGRATE_LOCKRES
2392 */
2393
2394
faf0ec9f 2395static int dlm_migrate_lockres(struct dlm_ctxt *dlm,
66effd3c 2396 struct dlm_lock_resource *res, u8 target)
6714d8e8
KH		 2397{
2398 struct dlm_master_list_entry *mle = NULL;
2399 struct dlm_master_list_entry *oldmle = NULL;
2400 struct dlm_migratable_lockres *mres = NULL;
2f5bf1f2 2401 int ret = 0;
6714d8e8
KH		 2402 const char *name;
2403 unsigned int namelen;
2404 int mle_added = 0;
2f5bf1f2 2405 int wake = 0;
6714d8e8
KH		 2406
2407 if (!dlm_grab(dlm))
2408 return -EINVAL;
2409
66effd3c
SM		 2410 BUG_ON(target == O2NM_MAX_NODES);
2411
6714d8e8
KH		 2412 name = res->lockname.name;
2413 namelen = res->lockname.len;
2414
66effd3c
SM		 2415 mlog(0, "%s: Migrating %.*s to node %u\n", dlm->name, namelen, name,
2416 target);
6714d8e8 2417
66effd3c 2418 /* preallocate up front. if this fails, abort */
6714d8e8 2419 ret = -ENOMEM;
ad8100e0 2420 mres = (struct dlm_migratable_lockres *) __get_free_page(GFP_NOFS);
6714d8e8
KH		 2421 if (!mres) {
2422 mlog_errno(ret);
2423 goto leave;
2424 }
2425
3914ed0c 2426 mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
6714d8e8
KH		 2427 if (!mle) {
2428 mlog_errno(ret);
2429 goto leave;
2430 }
2431 ret = 0;
2432
6714d8e8
KH		 2433 /*
2434 * clear any existing master requests and
2435 * add the migration mle to the list
2436 */
66effd3c 2437 spin_lock(&dlm->spinlock);
6714d8e8
KH		 2438 spin_lock(&dlm->master_lock);
2439 ret = dlm_add_migration_mle(dlm, res, mle, &oldmle, name,
2440 namelen, target, dlm->node_num);
2441 spin_unlock(&dlm->master_lock);
2442 spin_unlock(&dlm->spinlock);
2443
2444 if (ret == -EEXIST) {
2445 mlog(0, "another process is already migrating it\n");
2446 goto fail;
2447 }
2448 mle_added = 1;
2449
2450 /*
2451 * set the MIGRATING flag and flush asts
2452 * if we fail after this we need to re-dirty the lockres
2453 */
2454 if (dlm_mark_lockres_migrating(dlm, res, target) < 0) {
2455 mlog(ML_ERROR, "tried to migrate %.*s to %u, but "
2456 "the target went down.\n", res->lockname.len,
2457 res->lockname.name, target);
2458 spin_lock(&res->spinlock);
2459 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 2460 wake = 1;
6714d8e8
KH		 2461 spin_unlock(&res->spinlock);
2462 ret = -EINVAL;
2463 }
2464
2465fail:
2466 if (oldmle) {
2467 /* master is known, detach if not already detached */
2468 dlm_mle_detach_hb_events(dlm, oldmle);
2469 dlm_put_mle(oldmle);
2470 }
2471
2472 if (ret < 0) {
2473 if (mle_added) {
2474 dlm_mle_detach_hb_events(dlm, mle);
2475 dlm_put_mle(mle);
2476 } else if (mle) {
2477 kmem_cache_free(dlm_mle_cache, mle);
66effd3c 2478 mle = NULL;
6714d8e8
KH		 2479 }
2480 goto leave;
2481 }
2482
2483 /*
2484 * at this point, we have a migration target, an mle
2485 * in the master list, and the MIGRATING flag set on
2486 * the lockres
2487 */
2488
1cd04dbe
KH		 2489 /* now that remote nodes are spinning on the MIGRATING flag,
2490 * ensure that all assert_master work is flushed. */
2491 flush_workqueue(dlm->dlm_worker);
6714d8e8
KH		 2492
2493 /* get an extra reference on the mle.
2494 * otherwise the assert_master from the new
2495 * master will destroy this.
2496 * also, make sure that all callers of dlm_get_mle
2497 * take both dlm->spinlock and dlm->master_lock */
2498 spin_lock(&dlm->spinlock);
2499 spin_lock(&dlm->master_lock);
a2bf0477 2500 dlm_get_mle_inuse(mle);
6714d8e8
KH		 2501 spin_unlock(&dlm->master_lock);
2502 spin_unlock(&dlm->spinlock);
2503
2504 /* notify new node and send all lock state */
2505 /* call send_one_lockres with migration flag.
2506 * this serves as notice to the target node that a
2507 * migration is starting. */
2508 ret = dlm_send_one_lockres(dlm, res, mres, target,
2509 DLM_MRES_MIGRATION);
2510
2511 if (ret < 0) {
2512 mlog(0, "migration to node %u failed with %d\n",
2513 target, ret);
2514 /* migration failed, detach and clean up mle */
2515 dlm_mle_detach_hb_events(dlm, mle);
2516 dlm_put_mle(mle);
a2bf0477
KH		 2517 dlm_put_mle_inuse(mle);
2518 spin_lock(&res->spinlock);
2519 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 2520 wake = 1;
a2bf0477 2521 spin_unlock(&res->spinlock);
df016c66
SM		 2522 if (dlm_is_host_down(ret))
2523 dlm_wait_for_node_death(dlm, target,
2524 DLM_NODE_DEATH_WAIT_MAX);
6714d8e8
KH		 2525 goto leave;
2526 }
2527
2528 /* at this point, the target sends a message to all nodes,
2529 * (using dlm_do_migrate_request). this node is skipped since
2530 * we had to put an mle in the list to begin the process. this
2531 * node now waits for target to do an assert master. this node
2532 * will be the last one notified, ensuring that the migration
2533 * is complete everywhere. if the target dies while this is
2534 * going on, some nodes could potentially see the target as the
2535 * master, so it is important that my recovery finds the migration
af901ca1 2536 * mle and sets the master to UNKNOWN. */
6714d8e8
KH		 2537
2538
2539 /* wait for new node to assert master */
2540 while (1) {
2541 ret = wait_event_interruptible_timeout(mle->wq,
2542 (atomic_read(&mle->woken) == 1),
2543 msecs_to_jiffies(5000));
2544
2545 if (ret >= 0) {
2546 if (atomic_read(&mle->woken) == 1 ||
2547 res->owner == target)
2548 break;
2549
1cd04dbe
KH		 2550 mlog(0, "%s:%.*s: timed out during migration\n",
2551 dlm->name, res->lockname.len, res->lockname.name);
2bd63216 2552 /* avoid hang during shutdown when migrating lockres
e2faea4c
KH		 2553 * to a node which also goes down */
2554 if (dlm_is_node_dead(dlm, target)) {
aa852354
KH		 2555 mlog(0, "%s:%.*s: expected migration "
2556 "target %u is no longer up, restarting\n",
e2faea4c
KH		 2557 dlm->name, res->lockname.len,
2558 res->lockname.name, target);
1cd04dbe
KH		 2559 ret = -EINVAL;
2560 /* migration failed, detach and clean up mle */
2561 dlm_mle_detach_hb_events(dlm, mle);
2562 dlm_put_mle(mle);
2563 dlm_put_mle_inuse(mle);
2564 spin_lock(&res->spinlock);
2565 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 2566 wake = 1;
1cd04dbe
KH		 2567 spin_unlock(&res->spinlock);
2568 goto leave;
e2faea4c 2569 }
1cd04dbe
KH		 2570 } else
2571 mlog(0, "%s:%.*s: caught signal during migration\n",
2572 dlm->name, res->lockname.len, res->lockname.name);
6714d8e8
KH		 2573 }
2574
2575 /* all done, set the owner, clear the flag */
2576 spin_lock(&res->spinlock);
2577 dlm_set_lockres_owner(dlm, res, target);
2578 res->state &= ~DLM_LOCK_RES_MIGRATING;
2579 dlm_remove_nonlocal_locks(dlm, res);
2580 spin_unlock(&res->spinlock);
2581 wake_up(&res->wq);
2582
2583 /* master is known, detach if not already detached */
2584 dlm_mle_detach_hb_events(dlm, mle);
a2bf0477 2585 dlm_put_mle_inuse(mle);
6714d8e8
KH		 2586 ret = 0;
2587
2588 dlm_lockres_calc_usage(dlm, res);
2589
2590leave:
2591 /* re-dirty the lockres if we failed */
2592 if (ret < 0)
2593 dlm_kick_thread(dlm, res);
2594
a6fa3640
KH		 2595 /* wake up waiters if the MIGRATING flag got set
2596 * but migration failed */
2597 if (wake)
2598 wake_up(&res->wq);
2599
6714d8e8
KH		 2600 if (mres)
2601 free_page((unsigned long)mres);
2602
2603 dlm_put(dlm);
2604
9f62e960
SM		 2605 mlog(0, "%s: Migrating %.*s to %u, returns %d\n", dlm->name, namelen,
2606 name, target, ret);
6714d8e8
KH		 2607 return ret;
2608}
6714d8e8 2609
ba2bf218
KH		 2610#define DLM_MIGRATION_RETRY_MS 100
2611
9f62e960
SM		 2612/*
2613 * Should be called only after beginning the domain leave process.
ba2bf218
KH		 2614 * There should not be any remaining locks on nonlocal lock resources,
2615 * and there should be no local locks left on locally mastered resources.
2616 *
2617 * Called with the dlm spinlock held, may drop it to do migration, but
2618 * will re-acquire before exit.
2619 *
9f62e960
SM		 2620 * Returns: 1 if dlm->spinlock was dropped/retaken, 0 if never dropped
2621 */
ba2bf218
KH		 2622int dlm_empty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
2623{
66effd3c 2624 int ret;
ba2bf218 2625 int lock_dropped = 0;
66effd3c 2626 u8 target = O2NM_MAX_NODES;
ba2bf218 2627
9f62e960 2628 assert_spin_locked(&dlm->spinlock);
2f5bf1f2 2629
9f62e960 2630 spin_lock(&res->spinlock);
66effd3c
SM		 2631 if (dlm_is_lockres_migrateable(dlm, res))
2632 target = dlm_pick_migration_target(dlm, res);
b36c3f84 2633 spin_unlock(&res->spinlock);
66effd3c
SM		 2634
2635 if (target == O2NM_MAX_NODES)
9f62e960 2636 goto leave;
ba2bf218
KH		 2637
2638 /* Wheee! Migrate lockres here! Will sleep so drop spinlock. */
2639 spin_unlock(&dlm->spinlock);
2640 lock_dropped = 1;
66effd3c
SM		 2641 ret = dlm_migrate_lockres(dlm, res, target);
2642 if (ret)
2643 mlog(0, "%s: res %.*s, Migrate to node %u failed with %d\n",
2644 dlm->name, res->lockname.len, res->lockname.name,
2645 target, ret);
ba2bf218
KH		 2646 spin_lock(&dlm->spinlock);
2647leave:
2648 return lock_dropped;
2649}
2650
6714d8e8
KH		 2651int dlm_lock_basts_flushed(struct dlm_ctxt *dlm, struct dlm_lock *lock)
2652{
2653 int ret;
2654 spin_lock(&dlm->ast_lock);
2655 spin_lock(&lock->spinlock);
2656 ret = (list_empty(&lock->bast_list) && !lock->bast_pending);
2657 spin_unlock(&lock->spinlock);
2658 spin_unlock(&dlm->ast_lock);
2659 return ret;
2660}
2661
2662static int dlm_migration_can_proceed(struct dlm_ctxt *dlm,
2663 struct dlm_lock_resource *res,
2664 u8 mig_target)
2665{
2666 int can_proceed;
2667 spin_lock(&res->spinlock);
2668 can_proceed = !!(res->state & DLM_LOCK_RES_MIGRATING);
2669 spin_unlock(&res->spinlock);
2670
2bd63216 2671 /* target has died, so make the caller break out of the
6714d8e8
KH		 2672 * wait_event, but caller must recheck the domain_map */
2673 spin_lock(&dlm->spinlock);
2674 if (!test_bit(mig_target, dlm->domain_map))
2675 can_proceed = 1;
2676 spin_unlock(&dlm->spinlock);
2677 return can_proceed;
2678}
2679
faf0ec9f
AB		 2680static int dlm_lockres_is_dirty(struct dlm_ctxt *dlm,
2681 struct dlm_lock_resource *res)
6714d8e8
KH		 2682{
2683 int ret;
2684 spin_lock(&res->spinlock);
2685 ret = !!(res->state & DLM_LOCK_RES_DIRTY);
2686 spin_unlock(&res->spinlock);
2687 return ret;
2688}
2689
2690
2691static int dlm_mark_lockres_migrating(struct dlm_ctxt *dlm,
2692 struct dlm_lock_resource *res,
2693 u8 target)
2694{
2695 int ret = 0;
2696
2697 mlog(0, "dlm_mark_lockres_migrating: %.*s, from %u to %u\n",
2698 res->lockname.len, res->lockname.name, dlm->node_num,
2699 target);
2700 /* need to set MIGRATING flag on lockres. this is done by
2701 * ensuring that all asts have been flushed for this lockres. */
2702 spin_lock(&res->spinlock);
2703 BUG_ON(res->migration_pending);
2704 res->migration_pending = 1;
2705 /* strategy is to reserve an extra ast then release
2706 * it below, letting the release do all of the work */
2707 __dlm_lockres_reserve_ast(res);
2708 spin_unlock(&res->spinlock);
2709
ddc09c8d 2710 /* now flush all the pending asts */
6714d8e8 2711 dlm_kick_thread(dlm, res);
ddc09c8d
KH		 2712 /* before waiting on DIRTY, block processes which may
2713 * try to dirty the lockres before MIGRATING is set */
2714 spin_lock(&res->spinlock);
2715 BUG_ON(res->state & DLM_LOCK_RES_BLOCK_DIRTY);
2716 res->state |= DLM_LOCK_RES_BLOCK_DIRTY;
2717 spin_unlock(&res->spinlock);
2718 /* now wait on any pending asts and the DIRTY state */
6714d8e8
KH		 2719 wait_event(dlm->ast_wq, !dlm_lockres_is_dirty(dlm, res));
2720 dlm_lockres_release_ast(dlm, res);
2721
2722 mlog(0, "about to wait on migration_wq, dirty=%s\n",
2723 res->state & DLM_LOCK_RES_DIRTY ? "yes" : "no");
2724 /* if the extra ref we just put was the final one, this
2725 * will pass thru immediately. otherwise, we need to wait
2726 * for the last ast to finish. */
2727again:
2728 ret = wait_event_interruptible_timeout(dlm->migration_wq,
2729 dlm_migration_can_proceed(dlm, res, target),
2730 msecs_to_jiffies(1000));
2731 if (ret < 0) {
2732 mlog(0, "woken again: migrating? %s, dead? %s\n",
2733 res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no",
2734 test_bit(target, dlm->domain_map) ? "no":"yes");
2735 } else {
2736 mlog(0, "all is well: migrating? %s, dead? %s\n",
2737 res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no",
2738 test_bit(target, dlm->domain_map) ? "no":"yes");
2739 }
2740 if (!dlm_migration_can_proceed(dlm, res, target)) {
2741 mlog(0, "trying again...\n");
2742 goto again;
2743 }
2744
a39953dd 2745 ret = 0;
6714d8e8
KH		 2746 /* did the target go down or die? */
2747 spin_lock(&dlm->spinlock);
2748 if (!test_bit(target, dlm->domain_map)) {
2749 mlog(ML_ERROR, "aha. migration target %u just went down\n",
2750 target);
2751 ret = -EHOSTDOWN;
2752 }
2753 spin_unlock(&dlm->spinlock);
2754
a39953dd
WW		 2755 /*
2756 * if target is down, we need to clear DLM_LOCK_RES_BLOCK_DIRTY for
2757 * another try; otherwise, we are sure the MIGRATING state is there,
2758 * drop the unneded state which blocked threads trying to DIRTY
2759 */
2760 spin_lock(&res->spinlock);
2761 BUG_ON(!(res->state & DLM_LOCK_RES_BLOCK_DIRTY));
2762 res->state &= ~DLM_LOCK_RES_BLOCK_DIRTY;
2763 if (!ret)
2764 BUG_ON(!(res->state & DLM_LOCK_RES_MIGRATING));
2765 spin_unlock(&res->spinlock);
2766
6714d8e8
KH		 2767 /*
2768 * at this point:
2769 *
a39953dd 2770 * o the DLM_LOCK_RES_MIGRATING flag is set if target not down
6714d8e8
KH		 2771 * o there are no pending asts on this lockres
2772 * o all processes trying to reserve an ast on this
2773 * lockres must wait for the MIGRATING flag to clear
2774 */
2775 return ret;
2776}
2777
2778/* last step in the migration process.
2779 * original master calls this to free all of the dlm_lock
2780 * structures that used to be for other nodes. */
2781static void dlm_remove_nonlocal_locks(struct dlm_ctxt *dlm,
2782 struct dlm_lock_resource *res)
2783{
6714d8e8 2784 struct list_head *queue = &res->granted;
ba2bf218 2785 int i, bit;
800deef3 2786 struct dlm_lock *lock, *next;
6714d8e8
KH		 2787
2788 assert_spin_locked(&res->spinlock);
2789
2790 BUG_ON(res->owner == dlm->node_num);
2791
2792 for (i=0; i<3; i++) {
800deef3 2793 list_for_each_entry_safe(lock, next, queue, list) {
6714d8e8
KH		 2794 if (lock->ml.node != dlm->node_num) {
2795 mlog(0, "putting lock for node %u\n",
2796 lock->ml.node);
2797 /* be extra careful */
2798 BUG_ON(!list_empty(&lock->ast_list));
2799 BUG_ON(!list_empty(&lock->bast_list));
2800 BUG_ON(lock->ast_pending);
2801 BUG_ON(lock->bast_pending);
8d400b81
SM		 2802 dlm_lockres_clear_refmap_bit(dlm, res,
2803 lock->ml.node);
6714d8e8
KH		 2804 list_del_init(&lock->list);
2805 dlm_lock_put(lock);
2c5c54ac
SM		 2806 /* In a normal unlock, we would have added a
2807 * DLM_UNLOCK_FREE_LOCK action. Force it. */
2808 dlm_lock_put(lock);
6714d8e8
KH		 2809 }
2810 }
2811 queue++;
2812 }
ba2bf218
KH		 2813 bit = 0;
2814 while (1) {
2815 bit = find_next_bit(res->refmap, O2NM_MAX_NODES, bit);
2816 if (bit >= O2NM_MAX_NODES)
2817 break;
2818 /* do not clear the local node reference, if there is a
2819 * process holding this, let it drop the ref itself */
2820 if (bit != dlm->node_num) {
2821 mlog(0, "%s:%.*s: node %u had a ref to this "
2822 "migrating lockres, clearing\n", dlm->name,
2823 res->lockname.len, res->lockname.name, bit);
8d400b81 2824 dlm_lockres_clear_refmap_bit(dlm, res, bit);
ba2bf218
KH		 2825 }
2826 bit++;
2827 }
6714d8e8
KH		 2828}
2829
66effd3c
SM		 2830/*
2831 * Pick a node to migrate the lock resource to. This function selects a
2832 * potential target based first on the locks and then on refmap. It skips
2833 * nodes that are in the process of exiting the domain.
2834 */
6714d8e8
KH		 2835static u8 dlm_pick_migration_target(struct dlm_ctxt *dlm,
2836 struct dlm_lock_resource *res)
2837{
66effd3c 2838 enum dlm_lockres_list idx;
6714d8e8 2839 struct list_head *queue = &res->granted;
6714d8e8 2840 struct dlm_lock *lock;
66effd3c
SM		 2841 int noderef;
2842 u8 nodenum = O2NM_MAX_NODES;
6714d8e8
KH		 2843
2844 assert_spin_locked(&dlm->spinlock);
66effd3c 2845 assert_spin_locked(&res->spinlock);
6714d8e8 2846
66effd3c
SM		 2847 /* Go through all the locks */
2848 for (idx = DLM_GRANTED_LIST; idx <= DLM_BLOCKED_LIST; idx++) {
2849 queue = dlm_list_idx_to_ptr(res, idx);
800deef3 2850 list_for_each_entry(lock, queue, list) {
66effd3c
SM		 2851 if (lock->ml.node == dlm->node_num)
2852 continue;
2853 if (test_bit(lock->ml.node, dlm->exit_domain_map))
2854 continue;
2855 nodenum = lock->ml.node;
2856 goto bail;
6714d8e8 2857 }
6714d8e8 2858 }
388c4bcb 2859
66effd3c
SM		 2860 /* Go thru the refmap */
2861 noderef = -1;
6714d8e8 2862 while (1) {
66effd3c
SM		 2863 noderef = find_next_bit(res->refmap, O2NM_MAX_NODES,
2864 noderef + 1);
2865 if (noderef >= O2NM_MAX_NODES)
6714d8e8 2866 break;
66effd3c
SM		 2867 if (noderef == dlm->node_num)
2868 continue;
2869 if (test_bit(noderef, dlm->exit_domain_map))
2870 continue;
2871 nodenum = noderef;
2872 goto bail;
6714d8e8
KH		 2873 }
2874
66effd3c
SM		 2875bail:
2876 return nodenum;
6714d8e8
KH		 2877}
2878
6714d8e8
KH		 2879/* this is called by the new master once all lockres
2880 * data has been received */
2881static int dlm_do_migrate_request(struct dlm_ctxt *dlm,
2882 struct dlm_lock_resource *res,
2883 u8 master, u8 new_master,
2884 struct dlm_node_iter *iter)
2885{
2886 struct dlm_migrate_request migrate;
2b832564 2887 int ret, skip, status = 0;
6714d8e8
KH		 2888 int nodenum;
2889
2890 memset(&migrate, 0, sizeof(migrate));
2891 migrate.namelen = res->lockname.len;
2892 memcpy(migrate.name, res->lockname.name, migrate.namelen);
2893 migrate.new_master = new_master;
2894 migrate.master = master;
2895
2896 ret = 0;
2897
2898 /* send message to all nodes, except the master and myself */
2899 while ((nodenum = dlm_node_iter_next(iter)) >= 0) {
2900 if (nodenum == master ||
2901 nodenum == new_master)
2902 continue;
2903
2b832564
SM		 2904 /* We could race exit domain. If exited, skip. */
2905 spin_lock(&dlm->spinlock);
2906 skip = (!test_bit(nodenum, dlm->domain_map));
2907 spin_unlock(&dlm->spinlock);
2908 if (skip) {
2909 clear_bit(nodenum, iter->node_map);
2910 continue;
2911 }
2912
6714d8e8
KH		 2913 ret = o2net_send_message(DLM_MIGRATE_REQUEST_MSG, dlm->key,
2914 &migrate, sizeof(migrate), nodenum,
2915 &status);
2b832564 2916 if (ret < 0) {
8decab3c
SM		 2917 mlog(ML_ERROR, "%s: res %.*s, Error %d send "
2918 "MIGRATE_REQUEST to node %u\n", dlm->name,
2919 migrate.namelen, migrate.name, ret, nodenum);
2b832564
SM		 2920 if (!dlm_is_host_down(ret)) {
2921 mlog(ML_ERROR, "unhandled error=%d!\n", ret);
2922 BUG();
2923 }
2924 clear_bit(nodenum, iter->node_map);
2925 ret = 0;
2926 } else if (status < 0) {
6714d8e8
KH		 2927 mlog(0, "migrate request (node %u) returned %d!\n",
2928 nodenum, status);
2929 ret = status;
ba2bf218
KH		 2930 } else if (status == DLM_MIGRATE_RESPONSE_MASTERY_REF) {
2931 /* during the migration request we short-circuited
2932 * the mastery of the lockres. make sure we have
2933 * a mastery ref for nodenum */
2934 mlog(0, "%s:%.*s: need ref for node %u\n",
2935 dlm->name, res->lockname.len, res->lockname.name,
2936 nodenum);
2937 spin_lock(&res->spinlock);
8d400b81 2938 dlm_lockres_set_refmap_bit(dlm, res, nodenum);
ba2bf218 2939 spin_unlock(&res->spinlock);
6714d8e8
KH		 2940 }
2941 }
2942
2943 if (ret < 0)
2944 mlog_errno(ret);
2945
2946 mlog(0, "returning ret=%d\n", ret);
2947 return ret;
2948}
2949
2950
2951/* if there is an existing mle for this lockres, we now know who the master is.
2952 * (the one who sent us *this* message) we can clear it up right away.
2953 * since the process that put the mle on the list still has a reference to it,
2954 * we can unhash it now, set the master and wake the process. as a result,
2955 * we will have no mle in the list to start with. now we can add an mle for
2956 * the migration and this should be the only one found for those scanning the
2957 * list. */
d74c9803
KH		 2958int dlm_migrate_request_handler(struct o2net_msg *msg, u32 len, void *data,
2959 void **ret_data)
6714d8e8
KH		 2960{
2961 struct dlm_ctxt *dlm = data;
2962 struct dlm_lock_resource *res = NULL;
2963 struct dlm_migrate_request *migrate = (struct dlm_migrate_request *) msg->buf;
2964 struct dlm_master_list_entry *mle = NULL, *oldmle = NULL;
2965 const char *name;
a3d33291 2966 unsigned int namelen, hash;
6714d8e8
KH		 2967 int ret = 0;
2968
2969 if (!dlm_grab(dlm))
2970 return -EINVAL;
2971
2972 name = migrate->name;
2973 namelen = migrate->namelen;
a3d33291 2974 hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 2975
2976 /* preallocate.. if this fails, abort */
3914ed0c 2977 mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
6714d8e8
KH		 2978
2979 if (!mle) {
2980 ret = -ENOMEM;
2981 goto leave;
2982 }
2983
2984 /* check for pre-existing lock */
2985 spin_lock(&dlm->spinlock);
a3d33291 2986 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
6714d8e8
KH		 2987 if (res) {
2988 spin_lock(&res->spinlock);
2989 if (res->state & DLM_LOCK_RES_RECOVERING) {
2990 /* if all is working ok, this can only mean that we got
2991 * a migrate request from a node that we now see as
2992 * dead. what can we do here? drop it to the floor? */
2993 spin_unlock(&res->spinlock);
2994 mlog(ML_ERROR, "Got a migrate request, but the "
2995 "lockres is marked as recovering!");
2996 kmem_cache_free(dlm_mle_cache, mle);
2997 ret = -EINVAL; /* need a better solution */
2998 goto unlock;
2999 }
3000 res->state |= DLM_LOCK_RES_MIGRATING;
3001 spin_unlock(&res->spinlock);
3002 }
3003
6d98c3cc 3004 spin_lock(&dlm->master_lock);
6714d8e8
KH		 3005 /* ignore status. only nonzero status would BUG. */
3006 ret = dlm_add_migration_mle(dlm, res, mle, &oldmle,
3007 name, namelen,
3008 migrate->new_master,
3009 migrate->master);
3010
6714d8e8 3011 spin_unlock(&dlm->master_lock);
6d98c3cc 3012unlock:
6714d8e8
KH		 3013 spin_unlock(&dlm->spinlock);
3014
3015 if (oldmle) {
3016 /* master is known, detach if not already detached */
3017 dlm_mle_detach_hb_events(dlm, oldmle);
3018 dlm_put_mle(oldmle);
3019 }
3020
3021 if (res)
3022 dlm_lockres_put(res);
3023leave:
3024 dlm_put(dlm);
3025 return ret;
3026}
3027
3028/* must be holding dlm->spinlock and dlm->master_lock
3029 * when adding a migration mle, we can clear any other mles
3030 * in the master list because we know with certainty that
3031 * the master is "master". so we remove any old mle from
3032 * the list after setting it's master field, and then add
3033 * the new migration mle. this way we can hold with the rule
3034 * of having only one mle for a given lock name at all times. */
3035static int dlm_add_migration_mle(struct dlm_ctxt *dlm,
3036 struct dlm_lock_resource *res,
3037 struct dlm_master_list_entry *mle,
3038 struct dlm_master_list_entry **oldmle,
3039 const char *name, unsigned int namelen,
3040 u8 new_master, u8 master)
3041{
3042 int found;
3043 int ret = 0;
3044
3045 *oldmle = NULL;
3046
6714d8e8
KH		 3047 assert_spin_locked(&dlm->spinlock);
3048 assert_spin_locked(&dlm->master_lock);
3049
3050 /* caller is responsible for any ref taken here on oldmle */
3051 found = dlm_find_mle(dlm, oldmle, (char *)name, namelen);
3052 if (found) {
3053 struct dlm_master_list_entry *tmp = *oldmle;
3054 spin_lock(&tmp->spinlock);
3055 if (tmp->type == DLM_MLE_MIGRATION) {
3056 if (master == dlm->node_num) {
3057 /* ah another process raced me to it */
3058 mlog(0, "tried to migrate %.*s, but some "
3059 "process beat me to it\n",
3060 namelen, name);
3061 ret = -EEXIST;
3062 } else {
3063 /* bad. 2 NODES are trying to migrate! */
3064 mlog(ML_ERROR, "migration error mle: "
3065 "master=%u new_master=%u // request: "
3066 "master=%u new_master=%u // "
3067 "lockres=%.*s\n",
3068 tmp->master, tmp->new_master,
3069 master, new_master,
3070 namelen, name);
3071 BUG();
3072 }
3073 } else {
3074 /* this is essentially what assert_master does */
3075 tmp->master = master;
3076 atomic_set(&tmp->woken, 1);
3077 wake_up(&tmp->wq);
1c084577
SM		 3078 /* remove it so that only one mle will be found */
3079 __dlm_unlink_mle(dlm, tmp);
ba2bf218
KH		 3080 __dlm_mle_detach_hb_events(dlm, tmp);
3081 ret = DLM_MIGRATE_RESPONSE_MASTERY_REF;
3082 mlog(0, "%s:%.*s: master=%u, newmaster=%u, "
3083 "telling master to get ref for cleared out mle "
3084 "during migration\n", dlm->name, namelen, name,
3085 master, new_master);
6714d8e8
KH		 3086 }
3087 spin_unlock(&tmp->spinlock);
3088 }
3089
3090 /* now add a migration mle to the tail of the list */
3091 dlm_init_mle(mle, DLM_MLE_MIGRATION, dlm, res, name, namelen);
3092 mle->new_master = new_master;
ba2bf218
KH		 3093 /* the new master will be sending an assert master for this.
3094 * at that point we will get the refmap reference */
6714d8e8
KH		 3095 mle->master = master;
3096 /* do this for consistency with other mle types */
3097 set_bit(new_master, mle->maybe_map);
1c084577 3098 __dlm_insert_mle(dlm, mle);
6714d8e8
KH		 3099
3100 return ret;
3101}
3102
c2cd4a44
SM		 3103/*
3104 * Sets the owner of the lockres, associated to the mle, to UNKNOWN
3105 */
3106static struct dlm_lock_resource *dlm_reset_mleres_owner(struct dlm_ctxt *dlm,
3107 struct dlm_master_list_entry *mle)
3108{
3109 struct dlm_lock_resource *res;
c2cd4a44
SM		 3110
3111 /* Find the lockres associated to the mle and set its owner to UNK */
7141514b
SM		 3112 res = __dlm_lookup_lockres(dlm, mle->mname, mle->mnamelen,
3113 mle->mnamehash);
c2cd4a44
SM		 3114 if (res) {
3115 spin_unlock(&dlm->master_lock);
3116
3117 /* move lockres onto recovery list */
3118 spin_lock(&res->spinlock);
3119 dlm_set_lockres_owner(dlm, res, DLM_LOCK_RES_OWNER_UNKNOWN);
3120 dlm_move_lockres_to_recovery_list(dlm, res);
3121 spin_unlock(&res->spinlock);
3122 dlm_lockres_put(res);
3123
3124 /* about to get rid of mle, detach from heartbeat */
3125 __dlm_mle_detach_hb_events(dlm, mle);
3126
3127 /* dump the mle */
3128 spin_lock(&dlm->master_lock);
3129 __dlm_put_mle(mle);
3130 spin_unlock(&dlm->master_lock);
3131 }
3132
3133 return res;
3134}
3135
3136static void dlm_clean_migration_mle(struct dlm_ctxt *dlm,
3137 struct dlm_master_list_entry *mle)
3138{
3139 __dlm_mle_detach_hb_events(dlm, mle);
3140
3141 spin_lock(&mle->spinlock);
3142 __dlm_unlink_mle(dlm, mle);
3143 atomic_set(&mle->woken, 1);
3144 spin_unlock(&mle->spinlock);
3145
3146 wake_up(&mle->wq);
3147}
3148
3149static void dlm_clean_block_mle(struct dlm_ctxt *dlm,
3150 struct dlm_master_list_entry *mle, u8 dead_node)
3151{
3152 int bit;
3153
3154 BUG_ON(mle->type != DLM_MLE_BLOCK);
3155
3156 spin_lock(&mle->spinlock);
3157 bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0);
3158 if (bit != dead_node) {
3159 mlog(0, "mle found, but dead node %u would not have been "
3160 "master\n", dead_node);
3161 spin_unlock(&mle->spinlock);
3162 } else {
3163 /* Must drop the refcount by one since the assert_master will
3164 * never arrive. This may result in the mle being unlinked and
3165 * freed, but there may still be a process waiting in the
3166 * dlmlock path which is fine. */
3167 mlog(0, "node %u was expected master\n", dead_node);
3168 atomic_set(&mle->woken, 1);
3169 spin_unlock(&mle->spinlock);
3170 wake_up(&mle->wq);
3171
3172 /* Do not need events any longer, so detach from heartbeat */
3173 __dlm_mle_detach_hb_events(dlm, mle);
3174 __dlm_put_mle(mle);
3175 }
3176}
6714d8e8
KH		 3177
3178void dlm_clean_master_list(struct dlm_ctxt *dlm, u8 dead_node)
3179{
2ed6c750 3180 struct dlm_master_list_entry *mle;
6714d8e8 3181 struct dlm_lock_resource *res;
2ed6c750 3182 struct hlist_head *bucket;
df53cd3b 3183 struct hlist_node *tmp;
2ed6c750 3184 unsigned int i;
6714d8e8 3185
ef6b689b 3186 mlog(0, "dlm=%s, dead node=%u\n", dlm->name, dead_node);
6714d8e8
KH		 3187top:
3188 assert_spin_locked(&dlm->spinlock);
3189
3190 /* clean the master list */
3191 spin_lock(&dlm->master_lock);
2ed6c750
SM		 3192 for (i = 0; i < DLM_HASH_BUCKETS; i++) {
3193 bucket = dlm_master_hash(dlm, i);
df53cd3b 3194 hlist_for_each_entry_safe(mle, tmp, bucket, master_hash_node) {
67ae1f06
SM		 3195 BUG_ON(mle->type != DLM_MLE_BLOCK &&
3196 mle->type != DLM_MLE_MASTER &&
3197 mle->type != DLM_MLE_MIGRATION);
3198
3199 /* MASTER mles are initiated locally. The waiting
3200 * process will notice the node map change shortly.
3201 * Let that happen as normal. */
3202 if (mle->type == DLM_MLE_MASTER)
3203 continue;
3204
3205 /* BLOCK mles are initiated by other nodes. Need to
3206 * clean up if the dead node would have been the
3207 * master. */
3208 if (mle->type == DLM_MLE_BLOCK) {
3209 dlm_clean_block_mle(dlm, mle, dead_node);
3210 continue;
3211 }
6714d8e8 3212
67ae1f06
SM		 3213 /* Everything else is a MIGRATION mle */
3214
3215 /* The rule for MIGRATION mles is that the master
3216 * becomes UNKNOWN if *either* the original or the new
3217 * master dies. All UNKNOWN lockres' are sent to
3218 * whichever node becomes the recovery master. The new
3219 * master is responsible for determining if there is
3220 * still a master for this lockres, or if he needs to
3221 * take over mastery. Either way, this node should
3222 * expect another message to resolve this. */
3223
3224 if (mle->master != dead_node &&
3225 mle->new_master != dead_node)
3226 continue;
3227
3228 /* If we have reached this point, this mle needs to be
3229 * removed from the list and freed. */
3230 dlm_clean_migration_mle(dlm, mle);
3231
3232 mlog(0, "%s: node %u died during migration from "
3233 "%u to %u!\n", dlm->name, dead_node, mle->master,
3234 mle->new_master);
3235
3236 /* If we find a lockres associated with the mle, we've
3237 * hit this rare case that messes up our lock ordering.
3238 * If so, we need to drop the master lock so that we can
3239 * take the lockres lock, meaning that we will have to
3240 * restart from the head of list. */
3241 res = dlm_reset_mleres_owner(dlm, mle);
3242 if (res)
3243 /* restart */
3244 goto top;
3245
3246 /* This may be the last reference */
3247 __dlm_put_mle(mle);
6714d8e8 3248 }
2ed6c750 3249 }
6714d8e8
KH		 3250 spin_unlock(&dlm->master_lock);
3251}
3252
6714d8e8
KH		 3253int dlm_finish_migration(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
3254 u8 old_master)
3255{
3256 struct dlm_node_iter iter;
3257 int ret = 0;
3258
3259 spin_lock(&dlm->spinlock);
3260 dlm_node_iter_init(dlm->domain_map, &iter);
3261 clear_bit(old_master, iter.node_map);
3262 clear_bit(dlm->node_num, iter.node_map);
3263 spin_unlock(&dlm->spinlock);
3264
ba2bf218
KH		 3265 /* ownership of the lockres is changing. account for the
3266 * mastery reference here since old_master will briefly have
3267 * a reference after the migration completes */
3268 spin_lock(&res->spinlock);
8d400b81 3269 dlm_lockres_set_refmap_bit(dlm, res, old_master);
ba2bf218
KH		 3270 spin_unlock(&res->spinlock);
3271
6714d8e8
KH		 3272 mlog(0, "now time to do a migrate request to other nodes\n");
3273 ret = dlm_do_migrate_request(dlm, res, old_master,
3274 dlm->node_num, &iter);
3275 if (ret < 0) {
3276 mlog_errno(ret);
3277 goto leave;
3278 }
3279
3280 mlog(0, "doing assert master of %.*s to all except the original node\n",
3281 res->lockname.len, res->lockname.name);
3282 /* this call now finishes out the nodemap
3283 * even if one or more nodes die */
ba2bf218 3284 ret = dlm_do_assert_master(dlm, res, iter.node_map,
6714d8e8
KH		 3285 DLM_ASSERT_MASTER_FINISH_MIGRATION);
3286 if (ret < 0) {
3287 /* no longer need to retry. all living nodes contacted. */
3288 mlog_errno(ret);
3289 ret = 0;
3290 }
3291
3292 memset(iter.node_map, 0, sizeof(iter.node_map));
3293 set_bit(old_master, iter.node_map);
3294 mlog(0, "doing assert master of %.*s back to %u\n",
3295 res->lockname.len, res->lockname.name, old_master);
ba2bf218 3296 ret = dlm_do_assert_master(dlm, res, iter.node_map,
6714d8e8
KH		 3297 DLM_ASSERT_MASTER_FINISH_MIGRATION);
3298 if (ret < 0) {
3299 mlog(0, "assert master to original master failed "
3300 "with %d.\n", ret);
3301 /* the only nonzero status here would be because of
3302 * a dead original node. we're done. */
3303 ret = 0;
3304 }
3305
3306 /* all done, set the owner, clear the flag */
3307 spin_lock(&res->spinlock);
3308 dlm_set_lockres_owner(dlm, res, dlm->node_num);
3309 res->state &= ~DLM_LOCK_RES_MIGRATING;
3310 spin_unlock(&res->spinlock);
3311 /* re-dirty it on the new master */
3312 dlm_kick_thread(dlm, res);
3313 wake_up(&res->wq);
3314leave:
3315 return ret;
3316}
3317
3318/*
3319 * LOCKRES AST REFCOUNT
3320 * this is integral to migration
3321 */
3322
3323/* for future intent to call an ast, reserve one ahead of time.
3324 * this should be called only after waiting on the lockres
3325 * with dlm_wait_on_lockres, and while still holding the
3326 * spinlock after the call. */
3327void __dlm_lockres_reserve_ast(struct dlm_lock_resource *res)
3328{
3329 assert_spin_locked(&res->spinlock);
3330 if (res->state & DLM_LOCK_RES_MIGRATING) {
3331 __dlm_print_one_lock_resource(res);
3332 }
3333 BUG_ON(res->state & DLM_LOCK_RES_MIGRATING);
3334
3335 atomic_inc(&res->asts_reserved);
3336}
3337
3338/*
3339 * used to drop the reserved ast, either because it went unused,
3340 * or because the ast/bast was actually called.
3341 *
3342 * also, if there is a pending migration on this lockres,
3343 * and this was the last pending ast on the lockres,
3344 * atomically set the MIGRATING flag before we drop the lock.
3345 * this is how we ensure that migration can proceed with no
3346 * asts in progress. note that it is ok if the state of the
3347 * queues is such that a lock should be granted in the future
3348 * or that a bast should be fired, because the new master will
3349 * shuffle the lists on this lockres as soon as it is migrated.
3350 */
3351void dlm_lockres_release_ast(struct dlm_ctxt *dlm,
3352 struct dlm_lock_resource *res)
3353{
3354 if (!atomic_dec_and_lock(&res->asts_reserved, &res->spinlock))
3355 return;
3356
3357 if (!res->migration_pending) {
3358 spin_unlock(&res->spinlock);
3359 return;
3360 }
3361
3362 BUG_ON(res->state & DLM_LOCK_RES_MIGRATING);
3363 res->migration_pending = 0;
3364 res->state |= DLM_LOCK_RES_MIGRATING;
3365 spin_unlock(&res->spinlock);
3366 wake_up(&res->wq);
3367 wake_up(&dlm->migration_wq);
3368}
5dad6c39
SE		 3369
3370void dlm_force_free_mles(struct dlm_ctxt *dlm)
3371{
3372 int i;
3373 struct hlist_head *bucket;
3374 struct dlm_master_list_entry *mle;
df53cd3b 3375 struct hlist_node *tmp;
5dad6c39
SE		 3376
3377 /*
3378 * We notified all other nodes that we are exiting the domain and
3379 * marked the dlm state to DLM_CTXT_LEAVING. If any mles are still
3380 * around we force free them and wake any processes that are waiting
3381 * on the mles
3382 */
3383 spin_lock(&dlm->spinlock);
3384 spin_lock(&dlm->master_lock);
3385
3386 BUG_ON(dlm->dlm_state != DLM_CTXT_LEAVING);
3387 BUG_ON((find_next_bit(dlm->domain_map, O2NM_MAX_NODES, 0) < O2NM_MAX_NODES));
3388
3389 for (i = 0; i < DLM_HASH_BUCKETS; i++) {
3390 bucket = dlm_master_hash(dlm, i);
df53cd3b 3391 hlist_for_each_entry_safe(mle, tmp, bucket, master_hash_node) {
5dad6c39
SE		 3392 if (mle->type != DLM_MLE_BLOCK) {
3393 mlog(ML_ERROR, "bad mle: %p\n", mle);
3394 dlm_print_one_mle(mle);
3395 }
3396 atomic_set(&mle->woken, 1);
3397 wake_up(&mle->wq);
3398
3399 __dlm_unlink_mle(dlm, mle);
3400 __dlm_mle_detach_hb_events(dlm, mle);
3401 __dlm_put_mle(mle);
3402 }
3403 }
3404 spin_unlock(&dlm->master_lock);
3405 spin_unlock(&dlm->spinlock);
3406}
Linux 6.x block layer and io_uring tree(s)