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ocfs2: dlm: fix race between purge and get lock resource
[GitHub/mt8127/android_kernel_alcatel_ttab.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
SM		 344 struct hlist_head *bucket;
345 struct hlist_node *list;
346 unsigned int hash;
6714d8e8
KH		 347
348 assert_spin_locked(&dlm->master_lock);
349
2ed6c750
SM		 350 hash = dlm_lockid_hash(name, namelen);
351 bucket = dlm_master_hash(dlm, hash);
352 hlist_for_each(list, bucket) {
353 tmpmle = hlist_entry(list, struct dlm_master_list_entry,
354 master_hash_node);
6714d8e8
KH		 355 if (!dlm_mle_equal(dlm, tmpmle, name, namelen))
356 continue;
357 dlm_get_mle(tmpmle);
358 *mle = tmpmle;
359 return 1;
360 }
361 return 0;
362}
363
364void dlm_hb_event_notify_attached(struct dlm_ctxt *dlm, int idx, int node_up)
365{
366 struct dlm_master_list_entry *mle;
6714d8e8
KH		 367
368 assert_spin_locked(&dlm->spinlock);
2bd63216 369
800deef3 370 list_for_each_entry(mle, &dlm->mle_hb_events, hb_events) {
6714d8e8
KH		 371 if (node_up)
372 dlm_mle_node_up(dlm, mle, NULL, idx);
373 else
374 dlm_mle_node_down(dlm, mle, NULL, idx);
375 }
376}
377
378static void dlm_mle_node_down(struct dlm_ctxt *dlm,
379 struct dlm_master_list_entry *mle,
380 struct o2nm_node *node, int idx)
381{
382 spin_lock(&mle->spinlock);
383
384 if (!test_bit(idx, mle->node_map))
385 mlog(0, "node %u already removed from nodemap!\n", idx);
386 else
387 clear_bit(idx, mle->node_map);
388
389 spin_unlock(&mle->spinlock);
390}
391
392static void dlm_mle_node_up(struct dlm_ctxt *dlm,
393 struct dlm_master_list_entry *mle,
394 struct o2nm_node *node, int idx)
395{
396 spin_lock(&mle->spinlock);
397
398 if (test_bit(idx, mle->node_map))
399 mlog(0, "node %u already in node map!\n", idx);
400 else
401 set_bit(idx, mle->node_map);
402
403 spin_unlock(&mle->spinlock);
404}
405
406
407int dlm_init_mle_cache(void)
408{
12eb0035 409 dlm_mle_cache = kmem_cache_create("o2dlm_mle",
6714d8e8
KH		 410 sizeof(struct dlm_master_list_entry),
411 0, SLAB_HWCACHE_ALIGN,
20c2df83 412 NULL);
6714d8e8
KH		 413 if (dlm_mle_cache == NULL)
414 return -ENOMEM;
415 return 0;
416}
417
418void dlm_destroy_mle_cache(void)
419{
420 if (dlm_mle_cache)
421 kmem_cache_destroy(dlm_mle_cache);
422}
423
424static void dlm_mle_release(struct kref *kref)
425{
426 struct dlm_master_list_entry *mle;
427 struct dlm_ctxt *dlm;
428
6714d8e8
KH		 429 mle = container_of(kref, struct dlm_master_list_entry, mle_refs);
430 dlm = mle->dlm;
431
6714d8e8
KH		 432 assert_spin_locked(&dlm->spinlock);
433 assert_spin_locked(&dlm->master_lock);
434
7141514b
SM		 435 mlog(0, "Releasing mle for %.*s, type %d\n", mle->mnamelen, mle->mname,
436 mle->type);
2ed6c750 437
6714d8e8 438 /* remove from list if not already */
1c084577 439 __dlm_unlink_mle(dlm, mle);
6714d8e8
KH		 440
441 /* detach the mle from the domain node up/down events */
442 __dlm_mle_detach_hb_events(dlm, mle);
443
2041d8fd
SM		 444 atomic_dec(&dlm->mle_cur_count[mle->type]);
445
6714d8e8
KH		 446 /* NOTE: kfree under spinlock here.
447 * if this is bad, we can move this to a freelist. */
448 kmem_cache_free(dlm_mle_cache, mle);
449}
450
451
452/*
453 * LOCK RESOURCE FUNCTIONS
454 */
455
724bdca9
SM		 456int dlm_init_master_caches(void)
457{
458 dlm_lockres_cache = kmem_cache_create("o2dlm_lockres",
459 sizeof(struct dlm_lock_resource),
460 0, SLAB_HWCACHE_ALIGN, NULL);
461 if (!dlm_lockres_cache)
462 goto bail;
463
464 dlm_lockname_cache = kmem_cache_create("o2dlm_lockname",
465 DLM_LOCKID_NAME_MAX, 0,
466 SLAB_HWCACHE_ALIGN, NULL);
467 if (!dlm_lockname_cache)
468 goto bail;
469
470 return 0;
471bail:
472 dlm_destroy_master_caches();
473 return -ENOMEM;
474}
475
476void dlm_destroy_master_caches(void)
477{
478 if (dlm_lockname_cache)
479 kmem_cache_destroy(dlm_lockname_cache);
480
481 if (dlm_lockres_cache)
482 kmem_cache_destroy(dlm_lockres_cache);
483}
484
6714d8e8
KH		 485static void dlm_lockres_release(struct kref *kref)
486{
487 struct dlm_lock_resource *res;
b0d4f817 488 struct dlm_ctxt *dlm;
6714d8e8
KH		 489
490 res = container_of(kref, struct dlm_lock_resource, refs);
b0d4f817 491 dlm = res->dlm;
6714d8e8
KH		 492
493 /* This should not happen -- all lockres' have a name
494 * associated with them at init time. */
495 BUG_ON(!res->lockname.name);
496
497 mlog(0, "destroying lockres %.*s\n", res->lockname.len,
498 res->lockname.name);
499
b0d4f817 500 spin_lock(&dlm->track_lock);
29576f8b
SM		 501 if (!list_empty(&res->tracking))
502 list_del_init(&res->tracking);
503 else {
504 mlog(ML_ERROR, "Resource %.*s not on the Tracking list\n",
505 res->lockname.len, res->lockname.name);
506 dlm_print_one_lock_resource(res);
507 }
b0d4f817
SM		 508 spin_unlock(&dlm->track_lock);
509
6800791a
SM		 510 atomic_dec(&dlm->res_cur_count);
511
a7f90d83
KH		 512 if (!hlist_unhashed(&res->hash_node) ||
513 !list_empty(&res->granted) ||
514 !list_empty(&res->converting) ||
515 !list_empty(&res->blocked) ||
516 !list_empty(&res->dirty) ||
517 !list_empty(&res->recovering) ||
518 !list_empty(&res->purge)) {
519 mlog(ML_ERROR,
520 "Going to BUG for resource %.*s."
521 " We're on a list! [%c%c%c%c%c%c%c]\n",
522 res->lockname.len, res->lockname.name,
523 !hlist_unhashed(&res->hash_node) ? 'H' : ' ',
524 !list_empty(&res->granted) ? 'G' : ' ',
525 !list_empty(&res->converting) ? 'C' : ' ',
526 !list_empty(&res->blocked) ? 'B' : ' ',
527 !list_empty(&res->dirty) ? 'D' : ' ',
528 !list_empty(&res->recovering) ? 'R' : ' ',
529 !list_empty(&res->purge) ? 'P' : ' ');
530
531 dlm_print_one_lock_resource(res);
532 }
533
6714d8e8
KH		 534 /* By the time we're ready to blow this guy away, we shouldn't
535 * be on any lists. */
81f2094a 536 BUG_ON(!hlist_unhashed(&res->hash_node));
6714d8e8
KH		 537 BUG_ON(!list_empty(&res->granted));
538 BUG_ON(!list_empty(&res->converting));
539 BUG_ON(!list_empty(&res->blocked));
540 BUG_ON(!list_empty(&res->dirty));
541 BUG_ON(!list_empty(&res->recovering));
542 BUG_ON(!list_empty(&res->purge));
543
724bdca9 544 kmem_cache_free(dlm_lockname_cache, (void *)res->lockname.name);
6714d8e8 545
724bdca9 546 kmem_cache_free(dlm_lockres_cache, res);
6714d8e8
KH		 547}
548
6714d8e8
KH		 549void dlm_lockres_put(struct dlm_lock_resource *res)
550{
551 kref_put(&res->refs, dlm_lockres_release);
552}
553
554static void dlm_init_lockres(struct dlm_ctxt *dlm,
555 struct dlm_lock_resource *res,
556 const char *name, unsigned int namelen)
557{
558 char *qname;
559
560 /* If we memset here, we lose our reference to the kmalloc'd
561 * res->lockname.name, so be sure to init every field
562 * correctly! */
563
564 qname = (char *) res->lockname.name;
565 memcpy(qname, name, namelen);
566
567 res->lockname.len = namelen;
a3d33291 568 res->lockname.hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 569
570 init_waitqueue_head(&res->wq);
571 spin_lock_init(&res->spinlock);
81f2094a 572 INIT_HLIST_NODE(&res->hash_node);
6714d8e8
KH		 573 INIT_LIST_HEAD(&res->granted);
574 INIT_LIST_HEAD(&res->converting);
575 INIT_LIST_HEAD(&res->blocked);
576 INIT_LIST_HEAD(&res->dirty);
577 INIT_LIST_HEAD(&res->recovering);
578 INIT_LIST_HEAD(&res->purge);
29576f8b 579 INIT_LIST_HEAD(&res->tracking);
6714d8e8
KH		 580 atomic_set(&res->asts_reserved, 0);
581 res->migration_pending = 0;
ba2bf218 582 res->inflight_locks = 0;
6714d8e8 583
b0d4f817
SM		 584 res->dlm = dlm;
585
6714d8e8
KH		 586 kref_init(&res->refs);
587
6800791a
SM		 588 atomic_inc(&dlm->res_tot_count);
589 atomic_inc(&dlm->res_cur_count);
590
6714d8e8
KH		 591 /* just for consistency */
592 spin_lock(&res->spinlock);
593 dlm_set_lockres_owner(dlm, res, DLM_LOCK_RES_OWNER_UNKNOWN);
594 spin_unlock(&res->spinlock);
595
596 res->state = DLM_LOCK_RES_IN_PROGRESS;
597
598 res->last_used = 0;
599
18c6ac38 600 spin_lock(&dlm->spinlock);
29576f8b 601 list_add_tail(&res->tracking, &dlm->tracking_list);
18c6ac38 602 spin_unlock(&dlm->spinlock);
29576f8b 603
6714d8e8 604 memset(res->lvb, 0, DLM_LVB_LEN);
ba2bf218 605 memset(res->refmap, 0, sizeof(res->refmap));
6714d8e8
KH		 606}
607
608struct dlm_lock_resource *dlm_new_lockres(struct dlm_ctxt *dlm,
609 const char *name,
610 unsigned int namelen)
611{
724bdca9 612 struct dlm_lock_resource *res = NULL;
6714d8e8 613
3914ed0c 614 res = kmem_cache_zalloc(dlm_lockres_cache, GFP_NOFS);
6714d8e8 615 if (!res)
724bdca9 616 goto error;
6714d8e8 617
3914ed0c 618 res->lockname.name = kmem_cache_zalloc(dlm_lockname_cache, GFP_NOFS);
724bdca9
SM		 619 if (!res->lockname.name)
620 goto error;
6714d8e8
KH		 621
622 dlm_init_lockres(dlm, res, name, namelen);
623 return res;
724bdca9
SM		 624
625error:
626 if (res && res->lockname.name)
627 kmem_cache_free(dlm_lockname_cache, (void *)res->lockname.name);
628
629 if (res)
630 kmem_cache_free(dlm_lockres_cache, res);
631 return NULL;
6714d8e8
KH		 632}
633
8d400b81
SM		 634void dlm_lockres_set_refmap_bit(struct dlm_ctxt *dlm,
635 struct dlm_lock_resource *res, int bit)
ba2bf218 636{
8d400b81
SM		 637 assert_spin_locked(&res->spinlock);
638
639 mlog(0, "res %.*s, set node %u, %ps()\n", res->lockname.len,
640 res->lockname.name, bit, __builtin_return_address(0));
641
642 set_bit(bit, res->refmap);
643}
644
645void dlm_lockres_clear_refmap_bit(struct dlm_ctxt *dlm,
646 struct dlm_lock_resource *res, int bit)
647{
648 assert_spin_locked(&res->spinlock);
649
650 mlog(0, "res %.*s, clr node %u, %ps()\n", res->lockname.len,
651 res->lockname.name, bit, __builtin_return_address(0));
652
653 clear_bit(bit, res->refmap);
654}
655
64bee3b2 656static void __dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm,
8d400b81
SM		 657 struct dlm_lock_resource *res)
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
64bee3b2
JQ		 666void dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm,
667 struct dlm_lock_resource *res)
668{
669 assert_spin_locked(&res->spinlock);
670 __dlm_lockres_grab_inflight_ref(dlm, res);
671}
672
8d400b81
SM		 673void dlm_lockres_drop_inflight_ref(struct dlm_ctxt *dlm,
674 struct dlm_lock_resource *res)
ba2bf218
KH		 675{
676 assert_spin_locked(&res->spinlock);
677
678 BUG_ON(res->inflight_locks == 0);
8d400b81 679
ba2bf218 680 res->inflight_locks--;
ff0a522e 681
8d400b81
SM		 682 mlog(0, "%s: res %.*s, inflight--: now %u, %ps()\n", dlm->name,
683 res->lockname.len, res->lockname.name, res->inflight_locks,
684 __builtin_return_address(0));
685
ba2bf218
KH		 686 wake_up(&res->wq);
687}
688
6714d8e8
KH		 689/*
690 * lookup a lock resource by name.
691 * may already exist in the hashtable.
692 * lockid is null terminated
693 *
694 * if not, allocate enough for the lockres and for
695 * the temporary structure used in doing the mastering.
696 *
697 * also, do a lookup in the dlm->master_list to see
698 * if another node has begun mastering the same lock.
699 * if so, there should be a block entry in there
700 * for this name, and we should *not* attempt to master
701 * the lock here. need to wait around for that node
702 * to assert_master (or die).
703 *
704 */
705struct dlm_lock_resource * dlm_get_lock_resource(struct dlm_ctxt *dlm,
706 const char *lockid,
3384f3df 707 int namelen,
6714d8e8
KH		 708 int flags)
709{
710 struct dlm_lock_resource *tmpres=NULL, *res=NULL;
711 struct dlm_master_list_entry *mle = NULL;
712 struct dlm_master_list_entry *alloc_mle = NULL;
713 int blocked = 0;
714 int ret, nodenum;
715 struct dlm_node_iter iter;
3384f3df 716 unsigned int hash;
6714d8e8 717 int tries = 0;
c03872f5 718 int bit, wait_on_recovery = 0;
6714d8e8
KH		 719
720 BUG_ON(!lockid);
721
a3d33291 722 hash = dlm_lockid_hash(lockid, namelen);
6714d8e8
KH		 723
724 mlog(0, "get lockres %s (len %d)\n", lockid, namelen);
725
726lookup:
727 spin_lock(&dlm->spinlock);
ba2bf218 728 tmpres = __dlm_lookup_lockres_full(dlm, lockid, namelen, hash);
6714d8e8 729 if (tmpres) {
7b791d68 730 spin_unlock(&dlm->spinlock);
ba2bf218 731 spin_lock(&tmpres->spinlock);
93705a1b
JB		 732
733 /*
734 * Right after dlm spinlock was released, dlm_thread could have
735 * purged the lockres. Check if lockres got unhashed. If so
736 * start over.
737 */
738 if (hlist_unhashed(&tmpres->hash_node)) {
739 spin_unlock(&tmpres->spinlock);
740 dlm_lockres_put(tmpres);
741 tmpres = NULL;
742 goto lookup;
743 }
744
ff0a522e 745 /* Wait on the thread that is mastering the resource */
7b791d68
SM		 746 if (tmpres->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
747 __dlm_wait_on_lockres(tmpres);
748 BUG_ON(tmpres->owner == DLM_LOCK_RES_OWNER_UNKNOWN);
ff0a522e
SM		 749 spin_unlock(&tmpres->spinlock);
750 dlm_lockres_put(tmpres);
751 tmpres = NULL;
752 goto lookup;
7b791d68
SM		 753 }
754
ff0a522e
SM		 755 /* Wait on the resource purge to complete before continuing */
756 if (tmpres->state & DLM_LOCK_RES_DROPPING_REF) {
757 BUG_ON(tmpres->owner == dlm->node_num);
758 __dlm_wait_on_lockres_flags(tmpres,
759 DLM_LOCK_RES_DROPPING_REF);
ba2bf218
KH		 760 spin_unlock(&tmpres->spinlock);
761 dlm_lockres_put(tmpres);
762 tmpres = NULL;
763 goto lookup;
764 }
765
ff0a522e
SM		 766 /* Grab inflight ref to pin the resource */
767 dlm_lockres_grab_inflight_ref(dlm, tmpres);
768
769 spin_unlock(&tmpres->spinlock);
6714d8e8
KH		 770 if (res)
771 dlm_lockres_put(res);
772 res = tmpres;
773 goto leave;
774 }
775
776 if (!res) {
777 spin_unlock(&dlm->spinlock);
778 mlog(0, "allocating a new resource\n");
779 /* nothing found and we need to allocate one. */
3914ed0c 780 alloc_mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
6714d8e8
KH		 781 if (!alloc_mle)
782 goto leave;
783 res = dlm_new_lockres(dlm, lockid, namelen);
784 if (!res)
785 goto leave;
786 goto lookup;
787 }
788
789 mlog(0, "no lockres found, allocated our own: %p\n", res);
790
791 if (flags & LKM_LOCAL) {
792 /* caller knows it's safe to assume it's not mastered elsewhere
793 * DONE! return right away */
794 spin_lock(&res->spinlock);
795 dlm_change_lockres_owner(dlm, res, dlm->node_num);
796 __dlm_insert_lockres(dlm, res);
ba2bf218 797 dlm_lockres_grab_inflight_ref(dlm, res);
6714d8e8
KH		 798 spin_unlock(&res->spinlock);
799 spin_unlock(&dlm->spinlock);
800 /* lockres still marked IN_PROGRESS */
801 goto wake_waiters;
802 }
803
804 /* check master list to see if another node has started mastering it */
805 spin_lock(&dlm->master_lock);
806
807 /* if we found a block, wait for lock to be mastered by another node */
808 blocked = dlm_find_mle(dlm, &mle, (char *)lockid, namelen);
809 if (blocked) {
ba2bf218 810 int mig;
6714d8e8
KH		 811 if (mle->type == DLM_MLE_MASTER) {
812 mlog(ML_ERROR, "master entry for nonexistent lock!\n");
813 BUG();
ba2bf218
KH		 814 }
815 mig = (mle->type == DLM_MLE_MIGRATION);
816 /* if there is a migration in progress, let the migration
817 * finish before continuing. we can wait for the absence
818 * of the MIGRATION mle: either the migrate finished or
819 * one of the nodes died and the mle was cleaned up.
820 * if there is a BLOCK here, but it already has a master
821 * set, we are too late. the master does not have a ref
822 * for us in the refmap. detach the mle and drop it.
823 * either way, go back to the top and start over. */
824 if (mig || mle->master != O2NM_MAX_NODES) {
825 BUG_ON(mig && mle->master == dlm->node_num);
826 /* we arrived too late. the master does not
827 * have a ref for us. retry. */
828 mlog(0, "%s:%.*s: late on %s\n",
829 dlm->name, namelen, lockid,
830 mig ? "MIGRATION" : "BLOCK");
6714d8e8 831 spin_unlock(&dlm->master_lock);
6714d8e8
KH		 832 spin_unlock(&dlm->spinlock);
833
834 /* master is known, detach */
ba2bf218
KH		 835 if (!mig)
836 dlm_mle_detach_hb_events(dlm, mle);
6714d8e8
KH		 837 dlm_put_mle(mle);
838 mle = NULL;
25985edc 839 /* this is lame, but we can't wait on either
ba2bf218
KH		 840 * the mle or lockres waitqueue here */
841 if (mig)
842 msleep(100);
843 goto lookup;
6714d8e8
KH		 844 }
845 } else {
846 /* go ahead and try to master lock on this node */
847 mle = alloc_mle;
848 /* make sure this does not get freed below */
849 alloc_mle = NULL;
850 dlm_init_mle(mle, DLM_MLE_MASTER, dlm, res, NULL, 0);
851 set_bit(dlm->node_num, mle->maybe_map);
1c084577 852 __dlm_insert_mle(dlm, mle);
c03872f5
KH		 853
854 /* still holding the dlm spinlock, check the recovery map
2bd63216 855 * to see if there are any nodes that still need to be
c03872f5
KH		 856 * considered. these will not appear in the mle nodemap
857 * but they might own this lockres. wait on them. */
858 bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0);
859 if (bit < O2NM_MAX_NODES) {
8decab3c
SM		 860 mlog(0, "%s: res %.*s, At least one node (%d) "
861 "to recover before lock mastery can begin\n",
c03872f5
KH		 862 dlm->name, namelen, (char *)lockid, bit);
863 wait_on_recovery = 1;
864 }
6714d8e8
KH		 865 }
866
867 /* at this point there is either a DLM_MLE_BLOCK or a
868 * DLM_MLE_MASTER on the master list, so it's safe to add the
869 * lockres to the hashtable. anyone who finds the lock will
870 * still have to wait on the IN_PROGRESS. */
871
872 /* finally add the lockres to its hash bucket */
873 __dlm_insert_lockres(dlm, res);
8d400b81 874
64bee3b2
JQ		 875 /* since this lockres is new it doesn't not require the spinlock */
876 __dlm_lockres_grab_inflight_ref(dlm, res);
ba2bf218 877
6714d8e8
KH		 878 /* get an extra ref on the mle in case this is a BLOCK
879 * if so, the creator of the BLOCK may try to put the last
880 * ref at this time in the assert master handler, so we
881 * need an extra one to keep from a bad ptr deref. */
a2bf0477 882 dlm_get_mle_inuse(mle);
6714d8e8
KH		 883 spin_unlock(&dlm->master_lock);
884 spin_unlock(&dlm->spinlock);
885
e7e69eb3 886redo_request:
c03872f5
KH		 887 while (wait_on_recovery) {
888 /* any cluster changes that occurred after dropping the
889 * dlm spinlock would be detectable be a change on the mle,
890 * so we only need to clear out the recovery map once. */
891 if (dlm_is_recovery_lock(lockid, namelen)) {
8decab3c
SM		 892 mlog(0, "%s: Recovery map is not empty, but must "
893 "master $RECOVERY lock now\n", dlm->name);
c03872f5
KH		 894 if (!dlm_pre_master_reco_lockres(dlm, res))
895 wait_on_recovery = 0;
896 else {
897 mlog(0, "%s: waiting 500ms for heartbeat state "
898 "change\n", dlm->name);
899 msleep(500);
900 }
901 continue;
2bd63216 902 }
c03872f5
KH		 903
904 dlm_kick_recovery_thread(dlm);
aa087b84 905 msleep(1000);
c03872f5
KH		 906 dlm_wait_for_recovery(dlm);
907
908 spin_lock(&dlm->spinlock);
909 bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0);
910 if (bit < O2NM_MAX_NODES) {
8decab3c
SM		 911 mlog(0, "%s: res %.*s, At least one node (%d) "
912 "to recover before lock mastery can begin\n",
c03872f5
KH		 913 dlm->name, namelen, (char *)lockid, bit);
914 wait_on_recovery = 1;
915 } else
916 wait_on_recovery = 0;
917 spin_unlock(&dlm->spinlock);
b7084ab5
KH		 918
919 if (wait_on_recovery)
920 dlm_wait_for_node_recovery(dlm, bit, 10000);
c03872f5
KH		 921 }
922
6714d8e8
KH		 923 /* must wait for lock to be mastered elsewhere */
924 if (blocked)
925 goto wait;
926
6714d8e8
KH		 927 ret = -EINVAL;
928 dlm_node_iter_init(mle->vote_map, &iter);
929 while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
ba2bf218 930 ret = dlm_do_master_request(res, mle, nodenum);
6714d8e8
KH		 931 if (ret < 0)
932 mlog_errno(ret);
933 if (mle->master != O2NM_MAX_NODES) {
934 /* found a master ! */
9c6510a5
KH		 935 if (mle->master <= nodenum)
936 break;
937 /* if our master request has not reached the master
938 * yet, keep going until it does. this is how the
939 * master will know that asserts are needed back to
940 * the lower nodes. */
8decab3c
SM		 941 mlog(0, "%s: res %.*s, Requests only up to %u but "
942 "master is %u, keep going\n", dlm->name, namelen,
9c6510a5 943 lockid, nodenum, mle->master);
6714d8e8
KH		 944 }
945 }
946
947wait:
948 /* keep going until the response map includes all nodes */
949 ret = dlm_wait_for_lock_mastery(dlm, res, mle, &blocked);
950 if (ret < 0) {
e7e69eb3 951 wait_on_recovery = 1;
8decab3c
SM		 952 mlog(0, "%s: res %.*s, Node map changed, redo the master "
953 "request now, blocked=%d\n", dlm->name, res->lockname.len,
6714d8e8
KH		 954 res->lockname.name, blocked);
955 if (++tries > 20) {
8decab3c
SM		 956 mlog(ML_ERROR, "%s: res %.*s, Spinning on "
957 "dlm_wait_for_lock_mastery, blocked = %d\n",
2bd63216 958 dlm->name, res->lockname.len,
6714d8e8
KH		 959 res->lockname.name, blocked);
960 dlm_print_one_lock_resource(res);
8a9343fa 961 dlm_print_one_mle(mle);
6714d8e8
KH		 962 tries = 0;
963 }
964 goto redo_request;
965 }
966
8decab3c
SM		 967 mlog(0, "%s: res %.*s, Mastered by %u\n", dlm->name, res->lockname.len,
968 res->lockname.name, res->owner);
6714d8e8
KH		 969 /* make sure we never continue without this */
970 BUG_ON(res->owner == O2NM_MAX_NODES);
971
972 /* master is known, detach if not already detached */
973 dlm_mle_detach_hb_events(dlm, mle);
974 dlm_put_mle(mle);
975 /* put the extra ref */
a2bf0477 976 dlm_put_mle_inuse(mle);
6714d8e8
KH		 977
978wake_waiters:
979 spin_lock(&res->spinlock);
980 res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
981 spin_unlock(&res->spinlock);
982 wake_up(&res->wq);
983
984leave:
985 /* need to free the unused mle */
986 if (alloc_mle)
987 kmem_cache_free(dlm_mle_cache, alloc_mle);
988
989 return res;
990}
991
992
993#define DLM_MASTERY_TIMEOUT_MS 5000
994
995static int dlm_wait_for_lock_mastery(struct dlm_ctxt *dlm,
996 struct dlm_lock_resource *res,
997 struct dlm_master_list_entry *mle,
998 int *blocked)
999{
1000 u8 m;
1001 int ret, bit;
1002 int map_changed, voting_done;
1003 int assert, sleep;
1004
1005recheck:
1006 ret = 0;
1007 assert = 0;
1008
1009 /* check if another node has already become the owner */
1010 spin_lock(&res->spinlock);
1011 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
9c6510a5
KH		 1012 mlog(0, "%s:%.*s: owner is suddenly %u\n", dlm->name,
1013 res->lockname.len, res->lockname.name, res->owner);
6714d8e8 1014 spin_unlock(&res->spinlock);
9c6510a5
KH		 1015 /* this will cause the master to re-assert across
1016 * the whole cluster, freeing up mles */
588e0090 1017 if (res->owner != dlm->node_num) {
ba2bf218 1018 ret = dlm_do_master_request(res, mle, res->owner);
588e0090
KH		 1019 if (ret < 0) {
1020 /* give recovery a chance to run */
1021 mlog(ML_ERROR, "link to %u went down?: %d\n", res->owner, ret);
1022 msleep(500);
1023 goto recheck;
1024 }
9c6510a5
KH		 1025 }
1026 ret = 0;
6714d8e8
KH		 1027 goto leave;
1028 }
1029 spin_unlock(&res->spinlock);
1030
1031 spin_lock(&mle->spinlock);
1032 m = mle->master;
1033 map_changed = (memcmp(mle->vote_map, mle->node_map,
1034 sizeof(mle->vote_map)) != 0);
1035 voting_done = (memcmp(mle->vote_map, mle->response_map,
1036 sizeof(mle->vote_map)) == 0);
1037
1038 /* restart if we hit any errors */
1039 if (map_changed) {
1040 int b;
1041 mlog(0, "%s: %.*s: node map changed, restarting\n",
1042 dlm->name, res->lockname.len, res->lockname.name);
1043 ret = dlm_restart_lock_mastery(dlm, res, mle, *blocked);
1044 b = (mle->type == DLM_MLE_BLOCK);
1045 if ((*blocked && !b) || (!*blocked && b)) {
2bd63216 1046 mlog(0, "%s:%.*s: status change: old=%d new=%d\n",
6714d8e8
KH		 1047 dlm->name, res->lockname.len, res->lockname.name,
1048 *blocked, b);
1049 *blocked = b;
1050 }
1051 spin_unlock(&mle->spinlock);
1052 if (ret < 0) {
1053 mlog_errno(ret);
1054 goto leave;
1055 }
1056 mlog(0, "%s:%.*s: restart lock mastery succeeded, "
1057 "rechecking now\n", dlm->name, res->lockname.len,
1058 res->lockname.name);
1059 goto recheck;
aa852354
KH		 1060 } else {
1061 if (!voting_done) {
1062 mlog(0, "map not changed and voting not done "
1063 "for %s:%.*s\n", dlm->name, res->lockname.len,
1064 res->lockname.name);
1065 }
6714d8e8
KH		 1066 }
1067
1068 if (m != O2NM_MAX_NODES) {
1069 /* another node has done an assert!
1070 * all done! */
1071 sleep = 0;
1072 } else {
1073 sleep = 1;
1074 /* have all nodes responded? */
1075 if (voting_done && !*blocked) {
1076 bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0);
1077 if (dlm->node_num <= bit) {
1078 /* my node number is lowest.
1079 * now tell other nodes that I am
1080 * mastering this. */
1081 mle->master = dlm->node_num;
ba2bf218
KH		 1082 /* ref was grabbed in get_lock_resource
1083 * will be dropped in dlmlock_master */
6714d8e8
KH		 1084 assert = 1;
1085 sleep = 0;
1086 }
1087 /* if voting is done, but we have not received
1088 * an assert master yet, we must sleep */
1089 }
1090 }
1091
1092 spin_unlock(&mle->spinlock);
1093
1094 /* sleep if we haven't finished voting yet */
1095 if (sleep) {
1096 unsigned long timeo = msecs_to_jiffies(DLM_MASTERY_TIMEOUT_MS);
1097
1098 /*
1099 if (atomic_read(&mle->mle_refs.refcount) < 2)
1100 mlog(ML_ERROR, "mle (%p) refs=%d, name=%.*s\n", mle,
1101 atomic_read(&mle->mle_refs.refcount),
1102 res->lockname.len, res->lockname.name);
1103 */
1104 atomic_set(&mle->woken, 0);
1105 (void)wait_event_timeout(mle->wq,
1106 (atomic_read(&mle->woken) == 1),
1107 timeo);
1108 if (res->owner == O2NM_MAX_NODES) {
ba2bf218
KH		 1109 mlog(0, "%s:%.*s: waiting again\n", dlm->name,
1110 res->lockname.len, res->lockname.name);
6714d8e8
KH		 1111 goto recheck;
1112 }
1113 mlog(0, "done waiting, master is %u\n", res->owner);
1114 ret = 0;
1115 goto leave;
1116 }
1117
1118 ret = 0; /* done */
1119 if (assert) {
1120 m = dlm->node_num;
1121 mlog(0, "about to master %.*s here, this=%u\n",
1122 res->lockname.len, res->lockname.name, m);
ba2bf218 1123 ret = dlm_do_assert_master(dlm, res, mle->vote_map, 0);
6714d8e8
KH		 1124 if (ret) {
1125 /* This is a failure in the network path,
1126 * not in the response to the assert_master
1127 * (any nonzero response is a BUG on this node).
1128 * Most likely a socket just got disconnected
1129 * due to node death. */
1130 mlog_errno(ret);
1131 }
1132 /* no longer need to restart lock mastery.
1133 * all living nodes have been contacted. */
1134 ret = 0;
1135 }
1136
1137 /* set the lockres owner */
1138 spin_lock(&res->spinlock);
ba2bf218
KH		 1139 /* mastery reference obtained either during
1140 * assert_master_handler or in get_lock_resource */
6714d8e8
KH		 1141 dlm_change_lockres_owner(dlm, res, m);
1142 spin_unlock(&res->spinlock);
1143
1144leave:
1145 return ret;
1146}
1147
1148struct dlm_bitmap_diff_iter
1149{
1150 int curnode;
1151 unsigned long *orig_bm;
1152 unsigned long *cur_bm;
1153 unsigned long diff_bm[BITS_TO_LONGS(O2NM_MAX_NODES)];
1154};
1155
1156enum dlm_node_state_change
1157{
1158 NODE_DOWN = -1,
1159 NODE_NO_CHANGE = 0,
1160 NODE_UP
1161};
1162
1163static void dlm_bitmap_diff_iter_init(struct dlm_bitmap_diff_iter *iter,
1164 unsigned long *orig_bm,
1165 unsigned long *cur_bm)
1166{
1167 unsigned long p1, p2;
1168 int i;
1169
1170 iter->curnode = -1;
1171 iter->orig_bm = orig_bm;
1172 iter->cur_bm = cur_bm;
1173
1174 for (i = 0; i < BITS_TO_LONGS(O2NM_MAX_NODES); i++) {
1175 p1 = *(iter->orig_bm + i);
1176 p2 = *(iter->cur_bm + i);
1177 iter->diff_bm[i] = (p1 & ~p2) | (p2 & ~p1);
1178 }
1179}
1180
1181static int dlm_bitmap_diff_iter_next(struct dlm_bitmap_diff_iter *iter,
1182 enum dlm_node_state_change *state)
1183{
1184 int bit;
1185
1186 if (iter->curnode >= O2NM_MAX_NODES)
1187 return -ENOENT;
1188
1189 bit = find_next_bit(iter->diff_bm, O2NM_MAX_NODES,
1190 iter->curnode+1);
1191 if (bit >= O2NM_MAX_NODES) {
1192 iter->curnode = O2NM_MAX_NODES;
1193 return -ENOENT;
1194 }
1195
1196 /* if it was there in the original then this node died */
1197 if (test_bit(bit, iter->orig_bm))
1198 *state = NODE_DOWN;
1199 else
1200 *state = NODE_UP;
1201
1202 iter->curnode = bit;
1203 return bit;
1204}
1205
1206
1207static int dlm_restart_lock_mastery(struct dlm_ctxt *dlm,
1208 struct dlm_lock_resource *res,
1209 struct dlm_master_list_entry *mle,
1210 int blocked)
1211{
1212 struct dlm_bitmap_diff_iter bdi;
1213 enum dlm_node_state_change sc;
1214 int node;
1215 int ret = 0;
1216
1217 mlog(0, "something happened such that the "
1218 "master process may need to be restarted!\n");
1219
1220 assert_spin_locked(&mle->spinlock);
1221
1222 dlm_bitmap_diff_iter_init(&bdi, mle->vote_map, mle->node_map);
1223 node = dlm_bitmap_diff_iter_next(&bdi, &sc);
1224 while (node >= 0) {
1225 if (sc == NODE_UP) {
e2faea4c
KH		 1226 /* a node came up. clear any old vote from
1227 * the response map and set it in the vote map
1228 * then restart the mastery. */
1229 mlog(ML_NOTICE, "node %d up while restarting\n", node);
6714d8e8
KH		 1230
1231 /* redo the master request, but only for the new node */
1232 mlog(0, "sending request to new node\n");
1233 clear_bit(node, mle->response_map);
1234 set_bit(node, mle->vote_map);
1235 } else {
1236 mlog(ML_ERROR, "node down! %d\n", node);
6714d8e8
KH		 1237 if (blocked) {
1238 int lowest = find_next_bit(mle->maybe_map,
1239 O2NM_MAX_NODES, 0);
1240
1241 /* act like it was never there */
1242 clear_bit(node, mle->maybe_map);
1243
e7e69eb3
KH		 1244 if (node == lowest) {
1245 mlog(0, "expected master %u died"
1246 " while this node was blocked "
1247 "waiting on it!\n", node);
1248 lowest = find_next_bit(mle->maybe_map,
1249 O2NM_MAX_NODES,
1250 lowest+1);
1251 if (lowest < O2NM_MAX_NODES) {
1252 mlog(0, "%s:%.*s:still "
1253 "blocked. waiting on %u "
1254 "now\n", dlm->name,
1255 res->lockname.len,
1256 res->lockname.name,
1257 lowest);
1258 } else {
1259 /* mle is an MLE_BLOCK, but
1260 * there is now nothing left to
1261 * block on. we need to return
1262 * all the way back out and try
1263 * again with an MLE_MASTER.
1264 * dlm_do_local_recovery_cleanup
1265 * has already run, so the mle
1266 * refcount is ok */
1267 mlog(0, "%s:%.*s: no "
1268 "longer blocking. try to "
1269 "master this here\n",
1270 dlm->name,
1271 res->lockname.len,
1272 res->lockname.name);
1273 mle->type = DLM_MLE_MASTER;
7141514b 1274 mle->mleres = res;
e7e69eb3 1275 }
6714d8e8 1276 }
6714d8e8
KH		 1277 }
1278
e7e69eb3
KH		 1279 /* now blank out everything, as if we had never
1280 * contacted anyone */
1281 memset(mle->maybe_map, 0, sizeof(mle->maybe_map));
1282 memset(mle->response_map, 0, sizeof(mle->response_map));
1283 /* reset the vote_map to the current node_map */
1284 memcpy(mle->vote_map, mle->node_map,
1285 sizeof(mle->node_map));
1286 /* put myself into the maybe map */
1287 if (mle->type != DLM_MLE_BLOCK)
1288 set_bit(dlm->node_num, mle->maybe_map);
6714d8e8
KH		 1289 }
1290 ret = -EAGAIN;
6714d8e8
KH		 1291 node = dlm_bitmap_diff_iter_next(&bdi, &sc);
1292 }
1293 return ret;
1294}
1295
1296
1297/*
1298 * DLM_MASTER_REQUEST_MSG
1299 *
1300 * returns: 0 on success,
1301 * -errno on a network error
1302 *
1303 * on error, the caller should assume the target node is "dead"
1304 *
1305 */
1306
ba2bf218
KH		 1307static int dlm_do_master_request(struct dlm_lock_resource *res,
1308 struct dlm_master_list_entry *mle, int to)
6714d8e8
KH		 1309{
1310 struct dlm_ctxt *dlm = mle->dlm;
1311 struct dlm_master_request request;
1312 int ret, response=0, resend;
1313
1314 memset(&request, 0, sizeof(request));
1315 request.node_idx = dlm->node_num;
1316
1317 BUG_ON(mle->type == DLM_MLE_MIGRATION);
1318
7141514b
SM		 1319 request.namelen = (u8)mle->mnamelen;
1320 memcpy(request.name, mle->mname, request.namelen);
6714d8e8
KH		 1321
1322again:
1323 ret = o2net_send_message(DLM_MASTER_REQUEST_MSG, dlm->key, &request,
1324 sizeof(request), to, &response);
1325 if (ret < 0) {
1326 if (ret == -ESRCH) {
1327 /* should never happen */
1328 mlog(ML_ERROR, "TCP stack not ready!\n");
1329 BUG();
1330 } else if (ret == -EINVAL) {
1331 mlog(ML_ERROR, "bad args passed to o2net!\n");
1332 BUG();
1333 } else if (ret == -ENOMEM) {
1334 mlog(ML_ERROR, "out of memory while trying to send "
1335 "network message! retrying\n");
1336 /* this is totally crude */
1337 msleep(50);
1338 goto again;
1339 } else if (!dlm_is_host_down(ret)) {
1340 /* not a network error. bad. */
1341 mlog_errno(ret);
1342 mlog(ML_ERROR, "unhandled error!");
1343 BUG();
1344 }
1345 /* all other errors should be network errors,
1346 * and likely indicate node death */
1347 mlog(ML_ERROR, "link to %d went down!\n", to);
1348 goto out;
1349 }
1350
1351 ret = 0;
1352 resend = 0;
1353 spin_lock(&mle->spinlock);
1354 switch (response) {
1355 case DLM_MASTER_RESP_YES:
1356 set_bit(to, mle->response_map);
1357 mlog(0, "node %u is the master, response=YES\n", to);
ba2bf218
KH		 1358 mlog(0, "%s:%.*s: master node %u now knows I have a "
1359 "reference\n", dlm->name, res->lockname.len,
1360 res->lockname.name, to);
6714d8e8
KH		 1361 mle->master = to;
1362 break;
1363 case DLM_MASTER_RESP_NO:
1364 mlog(0, "node %u not master, response=NO\n", to);
1365 set_bit(to, mle->response_map);
1366 break;
1367 case DLM_MASTER_RESP_MAYBE:
1368 mlog(0, "node %u not master, response=MAYBE\n", to);
1369 set_bit(to, mle->response_map);
1370 set_bit(to, mle->maybe_map);
1371 break;
1372 case DLM_MASTER_RESP_ERROR:
1373 mlog(0, "node %u hit an error, resending\n", to);
1374 resend = 1;
1375 response = 0;
1376 break;
1377 default:
1378 mlog(ML_ERROR, "bad response! %u\n", response);
1379 BUG();
1380 }
1381 spin_unlock(&mle->spinlock);
1382 if (resend) {
1383 /* this is also totally crude */
1384 msleep(50);
1385 goto again;
1386 }
1387
1388out:
1389 return ret;
1390}
1391
1392/*
1393 * locks that can be taken here:
1394 * dlm->spinlock
1395 * res->spinlock
1396 * mle->spinlock
1397 * dlm->master_list
1398 *
1399 * if possible, TRIM THIS DOWN!!!
1400 */
d74c9803
KH		 1401int dlm_master_request_handler(struct o2net_msg *msg, u32 len, void *data,
1402 void **ret_data)
6714d8e8
KH		 1403{
1404 u8 response = DLM_MASTER_RESP_MAYBE;
1405 struct dlm_ctxt *dlm = data;
9c6510a5 1406 struct dlm_lock_resource *res = NULL;
6714d8e8
KH		 1407 struct dlm_master_request *request = (struct dlm_master_request *) msg->buf;
1408 struct dlm_master_list_entry *mle = NULL, *tmpmle = NULL;
1409 char *name;
a3d33291 1410 unsigned int namelen, hash;
6714d8e8
KH		 1411 int found, ret;
1412 int set_maybe;
9c6510a5 1413 int dispatch_assert = 0;
6714d8e8
KH		 1414
1415 if (!dlm_grab(dlm))
1416 return DLM_MASTER_RESP_NO;
1417
1418 if (!dlm_domain_fully_joined(dlm)) {
1419 response = DLM_MASTER_RESP_NO;
1420 goto send_response;
1421 }
1422
1423 name = request->name;
1424 namelen = request->namelen;
a3d33291 1425 hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 1426
1427 if (namelen > DLM_LOCKID_NAME_MAX) {
1428 response = DLM_IVBUFLEN;
1429 goto send_response;
1430 }
1431
1432way_up_top:
1433 spin_lock(&dlm->spinlock);
a3d33291 1434 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
6714d8e8
KH		 1435 if (res) {
1436 spin_unlock(&dlm->spinlock);
1437
1438 /* take care of the easy cases up front */
1439 spin_lock(&res->spinlock);
1cd04dbe
KH		 1440 if (res->state & (DLM_LOCK_RES_RECOVERING|
1441 DLM_LOCK_RES_MIGRATING)) {
6714d8e8
KH		 1442 spin_unlock(&res->spinlock);
1443 mlog(0, "returning DLM_MASTER_RESP_ERROR since res is "
1cd04dbe 1444 "being recovered/migrated\n");
6714d8e8
KH		 1445 response = DLM_MASTER_RESP_ERROR;
1446 if (mle)
1447 kmem_cache_free(dlm_mle_cache, mle);
1448 goto send_response;
1449 }
1450
1451 if (res->owner == dlm->node_num) {
8d400b81 1452 dlm_lockres_set_refmap_bit(dlm, res, request->node_idx);
6714d8e8 1453 spin_unlock(&res->spinlock);
6714d8e8
KH		 1454 response = DLM_MASTER_RESP_YES;
1455 if (mle)
1456 kmem_cache_free(dlm_mle_cache, mle);
1457
1458 /* this node is the owner.
1459 * there is some extra work that needs to
1460 * happen now. the requesting node has
1461 * caused all nodes up to this one to
1462 * create mles. this node now needs to
1463 * go back and clean those up. */
9c6510a5 1464 dispatch_assert = 1;
6714d8e8
KH		 1465 goto send_response;
1466 } else if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
1467 spin_unlock(&res->spinlock);
1468 // mlog(0, "node %u is the master\n", res->owner);
1469 response = DLM_MASTER_RESP_NO;
1470 if (mle)
1471 kmem_cache_free(dlm_mle_cache, mle);
1472 goto send_response;
1473 }
1474
1475 /* ok, there is no owner. either this node is
1476 * being blocked, or it is actively trying to
1477 * master this lock. */
1478 if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) {
1479 mlog(ML_ERROR, "lock with no owner should be "
1480 "in-progress!\n");
1481 BUG();
1482 }
1483
1484 // mlog(0, "lockres is in progress...\n");
1485 spin_lock(&dlm->master_lock);
1486 found = dlm_find_mle(dlm, &tmpmle, name, namelen);
1487 if (!found) {
1488 mlog(ML_ERROR, "no mle found for this lock!\n");
1489 BUG();
1490 }
1491 set_maybe = 1;
1492 spin_lock(&tmpmle->spinlock);
1493 if (tmpmle->type == DLM_MLE_BLOCK) {
1494 // mlog(0, "this node is waiting for "
1495 // "lockres to be mastered\n");
1496 response = DLM_MASTER_RESP_NO;
1497 } else if (tmpmle->type == DLM_MLE_MIGRATION) {
1498 mlog(0, "node %u is master, but trying to migrate to "
1499 "node %u.\n", tmpmle->master, tmpmle->new_master);
1500 if (tmpmle->master == dlm->node_num) {
6714d8e8
KH		 1501 mlog(ML_ERROR, "no owner on lockres, but this "
1502 "node is trying to migrate it to %u?!\n",
1503 tmpmle->new_master);
1504 BUG();
1505 } else {
1506 /* the real master can respond on its own */
1507 response = DLM_MASTER_RESP_NO;
1508 }
1509 } else if (tmpmle->master != DLM_LOCK_RES_OWNER_UNKNOWN) {
1510 set_maybe = 0;
9c6510a5 1511 if (tmpmle->master == dlm->node_num) {
6714d8e8 1512 response = DLM_MASTER_RESP_YES;
9c6510a5
KH		 1513 /* this node will be the owner.
1514 * go back and clean the mles on any
1515 * other nodes */
1516 dispatch_assert = 1;
8d400b81
SM		 1517 dlm_lockres_set_refmap_bit(dlm, res,
1518 request->node_idx);
9c6510a5 1519 } else
6714d8e8
KH		 1520 response = DLM_MASTER_RESP_NO;
1521 } else {
1522 // mlog(0, "this node is attempting to "
1523 // "master lockres\n");
1524 response = DLM_MASTER_RESP_MAYBE;
1525 }
1526 if (set_maybe)
1527 set_bit(request->node_idx, tmpmle->maybe_map);
1528 spin_unlock(&tmpmle->spinlock);
1529
1530 spin_unlock(&dlm->master_lock);
1531 spin_unlock(&res->spinlock);
1532
1533 /* keep the mle attached to heartbeat events */
1534 dlm_put_mle(tmpmle);
1535 if (mle)
1536 kmem_cache_free(dlm_mle_cache, mle);
1537 goto send_response;
1538 }
1539
1540 /*
1541 * lockres doesn't exist on this node
1542 * if there is an MLE_BLOCK, return NO
1543 * if there is an MLE_MASTER, return MAYBE
1544 * otherwise, add an MLE_BLOCK, return NO
1545 */
1546 spin_lock(&dlm->master_lock);
1547 found = dlm_find_mle(dlm, &tmpmle, name, namelen);
1548 if (!found) {
1549 /* this lockid has never been seen on this node yet */
1550 // mlog(0, "no mle found\n");
1551 if (!mle) {
1552 spin_unlock(&dlm->master_lock);
1553 spin_unlock(&dlm->spinlock);
1554
3914ed0c 1555 mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
6714d8e8 1556 if (!mle) {
6714d8e8 1557 response = DLM_MASTER_RESP_ERROR;
9c6510a5 1558 mlog_errno(-ENOMEM);
6714d8e8
KH		 1559 goto send_response;
1560 }
6714d8e8
KH		 1561 goto way_up_top;
1562 }
1563
1564 // mlog(0, "this is second time thru, already allocated, "
1565 // "add the block.\n");
41b8c8a1 1566 dlm_init_mle(mle, DLM_MLE_BLOCK, dlm, NULL, name, namelen);
6714d8e8 1567 set_bit(request->node_idx, mle->maybe_map);
1c084577 1568 __dlm_insert_mle(dlm, mle);
6714d8e8
KH		 1569 response = DLM_MASTER_RESP_NO;
1570 } else {
1571 // mlog(0, "mle was found\n");
1572 set_maybe = 1;
1573 spin_lock(&tmpmle->spinlock);
9c6510a5
KH		 1574 if (tmpmle->master == dlm->node_num) {
1575 mlog(ML_ERROR, "no lockres, but an mle with this node as master!\n");
1576 BUG();
1577 }
6714d8e8
KH		 1578 if (tmpmle->type == DLM_MLE_BLOCK)
1579 response = DLM_MASTER_RESP_NO;
1580 else if (tmpmle->type == DLM_MLE_MIGRATION) {
1581 mlog(0, "migration mle was found (%u->%u)\n",
1582 tmpmle->master, tmpmle->new_master);
6714d8e8
KH		 1583 /* real master can respond on its own */
1584 response = DLM_MASTER_RESP_NO;
9c6510a5
KH		 1585 } else
1586 response = DLM_MASTER_RESP_MAYBE;
6714d8e8
KH		 1587 if (set_maybe)
1588 set_bit(request->node_idx, tmpmle->maybe_map);
1589 spin_unlock(&tmpmle->spinlock);
1590 }
1591 spin_unlock(&dlm->master_lock);
1592 spin_unlock(&dlm->spinlock);
1593
1594 if (found) {
1595 /* keep the mle attached to heartbeat events */
1596 dlm_put_mle(tmpmle);
1597 }
1598send_response:
b31cfc02
SM		 1599 /*
1600 * __dlm_lookup_lockres() grabbed a reference to this lockres.
1601 * The reference is released by dlm_assert_master_worker() under
1602 * the call to dlm_dispatch_assert_master(). If
1603 * dlm_assert_master_worker() isn't called, we drop it here.
1604 */
9c6510a5
KH		 1605 if (dispatch_assert) {
1606 if (response != DLM_MASTER_RESP_YES)
1607 mlog(ML_ERROR, "invalid response %d\n", response);
1608 if (!res) {
1609 mlog(ML_ERROR, "bad lockres while trying to assert!\n");
1610 BUG();
1611 }
1612 mlog(0, "%u is the owner of %.*s, cleaning everyone else\n",
1613 dlm->node_num, res->lockname.len, res->lockname.name);
2bd63216 1614 ret = dlm_dispatch_assert_master(dlm, res, 0, request->node_idx,
9c6510a5
KH		 1615 DLM_ASSERT_MASTER_MLE_CLEANUP);
1616 if (ret < 0) {
1617 mlog(ML_ERROR, "failed to dispatch assert master work\n");
1618 response = DLM_MASTER_RESP_ERROR;
b31cfc02 1619 dlm_lockres_put(res);
9c6510a5 1620 }
b31cfc02
SM		 1621 } else {
1622 if (res)
1623 dlm_lockres_put(res);
9c6510a5
KH		 1624 }
1625
6714d8e8
KH		 1626 dlm_put(dlm);
1627 return response;
1628}
1629
1630/*
1631 * DLM_ASSERT_MASTER_MSG
1632 */
1633
1634
1635/*
1636 * NOTE: this can be used for debugging
1637 * can periodically run all locks owned by this node
1638 * and re-assert across the cluster...
1639 */
05488bbe
AB		 1640static int dlm_do_assert_master(struct dlm_ctxt *dlm,
1641 struct dlm_lock_resource *res,
1642 void *nodemap, u32 flags)
6714d8e8
KH		 1643{
1644 struct dlm_assert_master assert;
1645 int to, tmpret;
1646 struct dlm_node_iter iter;
1647 int ret = 0;
9c6510a5 1648 int reassert;
ba2bf218
KH		 1649 const char *lockname = res->lockname.name;
1650 unsigned int namelen = res->lockname.len;
6714d8e8
KH		 1651
1652 BUG_ON(namelen > O2NM_MAX_NAME_LEN);
f3f85464
SM		 1653
1654 spin_lock(&res->spinlock);
1655 res->state |= DLM_LOCK_RES_SETREF_INPROG;
1656 spin_unlock(&res->spinlock);
1657
9c6510a5
KH		 1658again:
1659 reassert = 0;
6714d8e8
KH		 1660
1661 /* note that if this nodemap is empty, it returns 0 */
1662 dlm_node_iter_init(nodemap, &iter);
1663 while ((to = dlm_node_iter_next(&iter)) >= 0) {
1664 int r = 0;
a9ee4c8a
KH		 1665 struct dlm_master_list_entry *mle = NULL;
1666
6714d8e8
KH		 1667 mlog(0, "sending assert master to %d (%.*s)\n", to,
1668 namelen, lockname);
1669 memset(&assert, 0, sizeof(assert));
1670 assert.node_idx = dlm->node_num;
1671 assert.namelen = namelen;
1672 memcpy(assert.name, lockname, namelen);
1673 assert.flags = cpu_to_be32(flags);
1674
1675 tmpret = o2net_send_message(DLM_ASSERT_MASTER_MSG, dlm->key,
1676 &assert, sizeof(assert), to, &r);
1677 if (tmpret < 0) {
a5196ec5
WW		 1678 mlog(ML_ERROR, "Error %d when sending message %u (key "
1679 "0x%x) to node %u\n", tmpret,
1680 DLM_ASSERT_MASTER_MSG, dlm->key, to);
6714d8e8 1681 if (!dlm_is_host_down(tmpret)) {
3b3b84a8 1682 mlog(ML_ERROR, "unhandled error=%d!\n", tmpret);
6714d8e8
KH		 1683 BUG();
1684 }
1685 /* a node died. finish out the rest of the nodes. */
3b3b84a8 1686 mlog(0, "link to %d went down!\n", to);
6714d8e8
KH		 1687 /* any nonzero status return will do */
1688 ret = tmpret;
ba2bf218 1689 r = 0;
6714d8e8
KH		 1690 } else if (r < 0) {
1691 /* ok, something horribly messed. kill thyself. */
1692 mlog(ML_ERROR,"during assert master of %.*s to %u, "
1693 "got %d.\n", namelen, lockname, to, r);
a9ee4c8a
KH		 1694 spin_lock(&dlm->spinlock);
1695 spin_lock(&dlm->master_lock);
1696 if (dlm_find_mle(dlm, &mle, (char *)lockname,
1697 namelen)) {
1698 dlm_print_one_mle(mle);
1699 __dlm_put_mle(mle);
1700 }
1701 spin_unlock(&dlm->master_lock);
1702 spin_unlock(&dlm->spinlock);
6714d8e8 1703 BUG();
ba2bf218
KH		 1704 }
1705
1706 if (r & DLM_ASSERT_RESPONSE_REASSERT &&
1707 !(r & DLM_ASSERT_RESPONSE_MASTERY_REF)) {
1708 mlog(ML_ERROR, "%.*s: very strange, "
1709 "master MLE but no lockres on %u\n",
1710 namelen, lockname, to);
1711 }
1712
1713 if (r & DLM_ASSERT_RESPONSE_REASSERT) {
9c6510a5 1714 mlog(0, "%.*s: node %u create mles on other "
2bd63216 1715 "nodes and requests a re-assert\n",
9c6510a5
KH		 1716 namelen, lockname, to);
1717 reassert = 1;
6714d8e8 1718 }
ba2bf218
KH		 1719 if (r & DLM_ASSERT_RESPONSE_MASTERY_REF) {
1720 mlog(0, "%.*s: node %u has a reference to this "
1721 "lockres, set the bit in the refmap\n",
1722 namelen, lockname, to);
1723 spin_lock(&res->spinlock);
8d400b81 1724 dlm_lockres_set_refmap_bit(dlm, res, to);
ba2bf218
KH		 1725 spin_unlock(&res->spinlock);
1726 }
6714d8e8
KH		 1727 }
1728
9c6510a5
KH		 1729 if (reassert)
1730 goto again;
1731
f3f85464
SM		 1732 spin_lock(&res->spinlock);
1733 res->state &= ~DLM_LOCK_RES_SETREF_INPROG;
1734 spin_unlock(&res->spinlock);
1735 wake_up(&res->wq);
1736
6714d8e8
KH		 1737 return ret;
1738}
1739
1740/*
1741 * locks that can be taken here:
1742 * dlm->spinlock
1743 * res->spinlock
1744 * mle->spinlock
1745 * dlm->master_list
1746 *
1747 * if possible, TRIM THIS DOWN!!!
1748 */
d74c9803
KH		 1749int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data,
1750 void **ret_data)
6714d8e8
KH		 1751{
1752 struct dlm_ctxt *dlm = data;
1753 struct dlm_master_list_entry *mle = NULL;
1754 struct dlm_assert_master *assert = (struct dlm_assert_master *)msg->buf;
1755 struct dlm_lock_resource *res = NULL;
1756 char *name;
a3d33291 1757 unsigned int namelen, hash;
6714d8e8 1758 u32 flags;
ba2bf218 1759 int master_request = 0, have_lockres_ref = 0;
9c6510a5 1760 int ret = 0;
6714d8e8
KH		 1761
1762 if (!dlm_grab(dlm))
1763 return 0;
1764
1765 name = assert->name;
1766 namelen = assert->namelen;
a3d33291 1767 hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 1768 flags = be32_to_cpu(assert->flags);
1769
1770 if (namelen > DLM_LOCKID_NAME_MAX) {
1771 mlog(ML_ERROR, "Invalid name length!");
1772 goto done;
1773 }
1774
1775 spin_lock(&dlm->spinlock);
1776
1777 if (flags)
1778 mlog(0, "assert_master with flags: %u\n", flags);
1779
1780 /* find the MLE */
1781 spin_lock(&dlm->master_lock);
1782 if (!dlm_find_mle(dlm, &mle, name, namelen)) {
1783 /* not an error, could be master just re-asserting */
1784 mlog(0, "just got an assert_master from %u, but no "
1785 "MLE for it! (%.*s)\n", assert->node_idx,
1786 namelen, name);
1787 } else {
1788 int bit = find_next_bit (mle->maybe_map, O2NM_MAX_NODES, 0);
1789 if (bit >= O2NM_MAX_NODES) {
1790 /* not necessarily an error, though less likely.
1791 * could be master just re-asserting. */
aa852354 1792 mlog(0, "no bits set in the maybe_map, but %u "
6714d8e8
KH		 1793 "is asserting! (%.*s)\n", assert->node_idx,
1794 namelen, name);
1795 } else if (bit != assert->node_idx) {
1796 if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) {
1797 mlog(0, "master %u was found, %u should "
1798 "back off\n", assert->node_idx, bit);
1799 } else {
1800 /* with the fix for bug 569, a higher node
1801 * number winning the mastery will respond
1802 * YES to mastery requests, but this node
1803 * had no way of knowing. let it pass. */
aa852354 1804 mlog(0, "%u is the lowest node, "
6714d8e8
KH		 1805 "%u is asserting. (%.*s) %u must "
1806 "have begun after %u won.\n", bit,
1807 assert->node_idx, namelen, name, bit,
1808 assert->node_idx);
1809 }
1810 }
2d1a868c
KH		 1811 if (mle->type == DLM_MLE_MIGRATION) {
1812 if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) {
1813 mlog(0, "%s:%.*s: got cleanup assert"
1814 " from %u for migration\n",
1815 dlm->name, namelen, name,
1816 assert->node_idx);
1817 } else if (!(flags & DLM_ASSERT_MASTER_FINISH_MIGRATION)) {
1818 mlog(0, "%s:%.*s: got unrelated assert"
1819 " from %u for migration, ignoring\n",
1820 dlm->name, namelen, name,
1821 assert->node_idx);
1822 __dlm_put_mle(mle);
1823 spin_unlock(&dlm->master_lock);
1824 spin_unlock(&dlm->spinlock);
1825 goto done;
2bd63216 1826 }
2d1a868c 1827 }
6714d8e8
KH		 1828 }
1829 spin_unlock(&dlm->master_lock);
1830
1831 /* ok everything checks out with the MLE
1832 * now check to see if there is a lockres */
a3d33291 1833 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
6714d8e8
KH		 1834 if (res) {
1835 spin_lock(&res->spinlock);
1836 if (res->state & DLM_LOCK_RES_RECOVERING) {
1837 mlog(ML_ERROR, "%u asserting but %.*s is "
1838 "RECOVERING!\n", assert->node_idx, namelen, name);
1839 goto kill;
1840 }
1841 if (!mle) {
dc2ed195
KH		 1842 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN &&
1843 res->owner != assert->node_idx) {
53ecd25e
SM		 1844 mlog(ML_ERROR, "DIE! Mastery assert from %u, "
1845 "but current owner is %u! (%.*s)\n",
1846 assert->node_idx, res->owner, namelen,
1847 name);
1848 __dlm_print_one_lock_resource(res);
1849 BUG();
6714d8e8
KH		 1850 }
1851 } else if (mle->type != DLM_MLE_MIGRATION) {
1852 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
1853 /* owner is just re-asserting */
1854 if (res->owner == assert->node_idx) {
1855 mlog(0, "owner %u re-asserting on "
1856 "lock %.*s\n", assert->node_idx,
1857 namelen, name);
1858 goto ok;
1859 }
1860 mlog(ML_ERROR, "got assert_master from "
1861 "node %u, but %u is the owner! "
1862 "(%.*s)\n", assert->node_idx,
1863 res->owner, namelen, name);
1864 goto kill;
1865 }
1866 if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) {
1867 mlog(ML_ERROR, "got assert from %u, but lock "
1868 "with no owner should be "
1869 "in-progress! (%.*s)\n",
1870 assert->node_idx,
1871 namelen, name);
1872 goto kill;
1873 }
1874 } else /* mle->type == DLM_MLE_MIGRATION */ {
1875 /* should only be getting an assert from new master */
1876 if (assert->node_idx != mle->new_master) {
1877 mlog(ML_ERROR, "got assert from %u, but "
1878 "new master is %u, and old master "
1879 "was %u (%.*s)\n",
1880 assert->node_idx, mle->new_master,
1881 mle->master, namelen, name);
1882 goto kill;
1883 }
1884
1885 }
1886ok:
1887 spin_unlock(&res->spinlock);
1888 }
6714d8e8
KH		 1889
1890 // mlog(0, "woo! got an assert_master from node %u!\n",
1891 // assert->node_idx);
1892 if (mle) {
9c6510a5
KH		 1893 int extra_ref = 0;
1894 int nn = -1;
a2bf0477 1895 int rr, err = 0;
2bd63216 1896
6714d8e8 1897 spin_lock(&mle->spinlock);
9c6510a5
KH		 1898 if (mle->type == DLM_MLE_BLOCK || mle->type == DLM_MLE_MIGRATION)
1899 extra_ref = 1;
1900 else {
1901 /* MASTER mle: if any bits set in the response map
1902 * then the calling node needs to re-assert to clear
1903 * up nodes that this node contacted */
2bd63216 1904 while ((nn = find_next_bit (mle->response_map, O2NM_MAX_NODES,
9c6510a5
KH		 1905 nn+1)) < O2NM_MAX_NODES) {
1906 if (nn != dlm->node_num && nn != assert->node_idx)
1907 master_request = 1;
1908 }
1909 }
6714d8e8
KH		 1910 mle->master = assert->node_idx;
1911 atomic_set(&mle->woken, 1);
1912 wake_up(&mle->wq);
1913 spin_unlock(&mle->spinlock);
1914
a2bf0477 1915 if (res) {
a6fa3640 1916 int wake = 0;
6714d8e8 1917 spin_lock(&res->spinlock);
a2bf0477
KH		 1918 if (mle->type == DLM_MLE_MIGRATION) {
1919 mlog(0, "finishing off migration of lockres %.*s, "
1920 "from %u to %u\n",
1921 res->lockname.len, res->lockname.name,
1922 dlm->node_num, mle->new_master);
1923 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 1924 wake = 1;
a2bf0477
KH		 1925 dlm_change_lockres_owner(dlm, res, mle->new_master);
1926 BUG_ON(res->state & DLM_LOCK_RES_DIRTY);
1927 } else {
1928 dlm_change_lockres_owner(dlm, res, mle->master);
1929 }
6714d8e8 1930 spin_unlock(&res->spinlock);
ba2bf218 1931 have_lockres_ref = 1;
a6fa3640
KH		 1932 if (wake)
1933 wake_up(&res->wq);
6714d8e8 1934 }
a2bf0477
KH		 1935
1936 /* master is known, detach if not already detached.
1937 * ensures that only one assert_master call will happen
1938 * on this mle. */
a2bf0477
KH		 1939 spin_lock(&dlm->master_lock);
1940
1941 rr = atomic_read(&mle->mle_refs.refcount);
1942 if (mle->inuse > 0) {
1943 if (extra_ref && rr < 3)
1944 err = 1;
1945 else if (!extra_ref && rr < 2)
1946 err = 1;
1947 } else {
1948 if (extra_ref && rr < 2)
1949 err = 1;
1950 else if (!extra_ref && rr < 1)
1951 err = 1;
1952 }
1953 if (err) {
1954 mlog(ML_ERROR, "%s:%.*s: got assert master from %u "
1955 "that will mess up this node, refs=%d, extra=%d, "
1956 "inuse=%d\n", dlm->name, namelen, name,
1957 assert->node_idx, rr, extra_ref, mle->inuse);
1958 dlm_print_one_mle(mle);
1959 }
1c084577 1960 __dlm_unlink_mle(dlm, mle);
a2bf0477
KH		 1961 __dlm_mle_detach_hb_events(dlm, mle);
1962 __dlm_put_mle(mle);
6714d8e8
KH		 1963 if (extra_ref) {
1964 /* the assert master message now balances the extra
1965 * ref given by the master / migration request message.
1966 * if this is the last put, it will be removed
1967 * from the list. */
a2bf0477
KH		 1968 __dlm_put_mle(mle);
1969 }
1970 spin_unlock(&dlm->master_lock);
a2bf0477
KH		 1971 } else if (res) {
1972 if (res->owner != assert->node_idx) {
1973 mlog(0, "assert_master from %u, but current "
1974 "owner is %u (%.*s), no mle\n", assert->node_idx,
1975 res->owner, namelen, name);
6714d8e8
KH		 1976 }
1977 }
14741472 1978 spin_unlock(&dlm->spinlock);
6714d8e8
KH		 1979
1980done:
9c6510a5 1981 ret = 0;
3b8118cf
KH		 1982 if (res) {
1983 spin_lock(&res->spinlock);
1984 res->state |= DLM_LOCK_RES_SETREF_INPROG;
1985 spin_unlock(&res->spinlock);
1986 *ret_data = (void *)res;
1987 }
6714d8e8 1988 dlm_put(dlm);
9c6510a5
KH		 1989 if (master_request) {
1990 mlog(0, "need to tell master to reassert\n");
ba2bf218
KH		 1991 /* positive. negative would shoot down the node. */
1992 ret |= DLM_ASSERT_RESPONSE_REASSERT;
1993 if (!have_lockres_ref) {
1994 mlog(ML_ERROR, "strange, got assert from %u, MASTER "
1995 "mle present here for %s:%.*s, but no lockres!\n",
1996 assert->node_idx, dlm->name, namelen, name);
1997 }
1998 }
1999 if (have_lockres_ref) {
2000 /* let the master know we have a reference to the lockres */
2001 ret |= DLM_ASSERT_RESPONSE_MASTERY_REF;
2002 mlog(0, "%s:%.*s: got assert from %u, need a ref\n",
2003 dlm->name, namelen, name, assert->node_idx);
9c6510a5
KH		 2004 }
2005 return ret;
6714d8e8
KH		 2006
2007kill:
2008 /* kill the caller! */
a9ee4c8a
KH		 2009 mlog(ML_ERROR, "Bad message received from another node. Dumping state "
2010 "and killing the other node now! This node is OK and can continue.\n");
2011 __dlm_print_one_lock_resource(res);
6714d8e8
KH		 2012 spin_unlock(&res->spinlock);
2013 spin_unlock(&dlm->spinlock);
2bd63216 2014 *ret_data = (void *)res;
6714d8e8
KH		 2015 dlm_put(dlm);
2016 return -EINVAL;
2017}
2018
3b8118cf
KH		 2019void dlm_assert_master_post_handler(int status, void *data, void *ret_data)
2020{
2021 struct dlm_lock_resource *res = (struct dlm_lock_resource *)ret_data;
2022
2023 if (ret_data) {
2024 spin_lock(&res->spinlock);
2025 res->state &= ~DLM_LOCK_RES_SETREF_INPROG;
2026 spin_unlock(&res->spinlock);
2027 wake_up(&res->wq);
2028 dlm_lockres_put(res);
2029 }
2030 return;
2031}
2032
6714d8e8
KH		 2033int dlm_dispatch_assert_master(struct dlm_ctxt *dlm,
2034 struct dlm_lock_resource *res,
2035 int ignore_higher, u8 request_from, u32 flags)
2036{
2037 struct dlm_work_item *item;
b24ae0b5 2038 item = kzalloc(sizeof(*item), GFP_ATOMIC);
6714d8e8
KH		 2039 if (!item)
2040 return -ENOMEM;
2041
2042
2043 /* queue up work for dlm_assert_master_worker */
2044 dlm_grab(dlm); /* get an extra ref for the work item */
2045 dlm_init_work_item(dlm, item, dlm_assert_master_worker, NULL);
2046 item->u.am.lockres = res; /* already have a ref */
2047 /* can optionally ignore node numbers higher than this node */
2048 item->u.am.ignore_higher = ignore_higher;
2049 item->u.am.request_from = request_from;
2050 item->u.am.flags = flags;
2051
2bd63216
SM		 2052 if (ignore_higher)
2053 mlog(0, "IGNORE HIGHER: %.*s\n", res->lockname.len,
9c6510a5 2054 res->lockname.name);
2bd63216 2055
6714d8e8
KH		 2056 spin_lock(&dlm->work_lock);
2057 list_add_tail(&item->list, &dlm->work_list);
2058 spin_unlock(&dlm->work_lock);
2059
3156d267 2060 queue_work(dlm->dlm_worker, &dlm->dispatched_work);
6714d8e8
KH		 2061 return 0;
2062}
2063
2064static void dlm_assert_master_worker(struct dlm_work_item *item, void *data)
2065{
2066 struct dlm_ctxt *dlm = data;
2067 int ret = 0;
2068 struct dlm_lock_resource *res;
2069 unsigned long nodemap[BITS_TO_LONGS(O2NM_MAX_NODES)];
2070 int ignore_higher;
2071 int bit;
2072 u8 request_from;
2073 u32 flags;
2074
2075 dlm = item->dlm;
2076 res = item->u.am.lockres;
2077 ignore_higher = item->u.am.ignore_higher;
2078 request_from = item->u.am.request_from;
2079 flags = item->u.am.flags;
2080
2081 spin_lock(&dlm->spinlock);
2082 memcpy(nodemap, dlm->domain_map, sizeof(nodemap));
2083 spin_unlock(&dlm->spinlock);
2084
2085 clear_bit(dlm->node_num, nodemap);
2086 if (ignore_higher) {
2087 /* if is this just to clear up mles for nodes below
2088 * this node, do not send the message to the original
2089 * caller or any node number higher than this */
2090 clear_bit(request_from, nodemap);
2091 bit = dlm->node_num;
2092 while (1) {
2093 bit = find_next_bit(nodemap, O2NM_MAX_NODES,
2094 bit+1);
2095 if (bit >= O2NM_MAX_NODES)
2096 break;
2097 clear_bit(bit, nodemap);
2098 }
2099 }
2100
36407488
KH		 2101 /*
2102 * If we're migrating this lock to someone else, we are no
2103 * longer allowed to assert out own mastery. OTOH, we need to
2104 * prevent migration from starting while we're still asserting
2105 * our dominance. The reserved ast delays migration.
2106 */
2107 spin_lock(&res->spinlock);
2108 if (res->state & DLM_LOCK_RES_MIGRATING) {
2109 mlog(0, "Someone asked us to assert mastery, but we're "
2110 "in the middle of migration. Skipping assert, "
2111 "the new master will handle that.\n");
2112 spin_unlock(&res->spinlock);
2113 goto put;
2114 } else
2115 __dlm_lockres_reserve_ast(res);
2116 spin_unlock(&res->spinlock);
2117
6714d8e8
KH		 2118 /* this call now finishes out the nodemap
2119 * even if one or more nodes die */
2120 mlog(0, "worker about to master %.*s here, this=%u\n",
2121 res->lockname.len, res->lockname.name, dlm->node_num);
ba2bf218 2122 ret = dlm_do_assert_master(dlm, res, nodemap, flags);
6714d8e8
KH		 2123 if (ret < 0) {
2124 /* no need to restart, we are done */
3b3b84a8
KH		 2125 if (!dlm_is_host_down(ret))
2126 mlog_errno(ret);
6714d8e8
KH		 2127 }
2128
36407488
KH		 2129 /* Ok, we've asserted ourselves. Let's let migration start. */
2130 dlm_lockres_release_ast(dlm, res);
2131
2132put:
6714d8e8
KH		 2133 dlm_lockres_put(res);
2134
2135 mlog(0, "finished with dlm_assert_master_worker\n");
2136}
2137
c03872f5
KH		 2138/* SPECIAL CASE for the $RECOVERY lock used by the recovery thread.
2139 * We cannot wait for node recovery to complete to begin mastering this
2140 * lockres because this lockres is used to kick off recovery! ;-)
2141 * So, do a pre-check on all living nodes to see if any of those nodes
2142 * think that $RECOVERY is currently mastered by a dead node. If so,
2143 * we wait a short time to allow that node to get notified by its own
2144 * heartbeat stack, then check again. All $RECOVERY lock resources
2bd63216 2145 * mastered by dead nodes are purged when the hearbeat callback is
c03872f5
KH		 2146 * fired, so we can know for sure that it is safe to continue once
2147 * the node returns a live node or no node. */
2148static int dlm_pre_master_reco_lockres(struct dlm_ctxt *dlm,
2149 struct dlm_lock_resource *res)
2150{
2151 struct dlm_node_iter iter;
2152 int nodenum;
2153 int ret = 0;
2154 u8 master = DLM_LOCK_RES_OWNER_UNKNOWN;
2155
2156 spin_lock(&dlm->spinlock);
2157 dlm_node_iter_init(dlm->domain_map, &iter);
2158 spin_unlock(&dlm->spinlock);
2159
2160 while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2161 /* do not send to self */
2162 if (nodenum == dlm->node_num)
2163 continue;
2164 ret = dlm_do_master_requery(dlm, res, nodenum, &master);
2165 if (ret < 0) {
2166 mlog_errno(ret);
2167 if (!dlm_is_host_down(ret))
2168 BUG();
2169 /* host is down, so answer for that node would be
2170 * DLM_LOCK_RES_OWNER_UNKNOWN. continue. */
f42a100b 2171 ret = 0;
c03872f5
KH		 2172 }
2173
2174 if (master != DLM_LOCK_RES_OWNER_UNKNOWN) {
2175 /* check to see if this master is in the recovery map */
2176 spin_lock(&dlm->spinlock);
2177 if (test_bit(master, dlm->recovery_map)) {
2178 mlog(ML_NOTICE, "%s: node %u has not seen "
2179 "node %u go down yet, and thinks the "
2180 "dead node is mastering the recovery "
2181 "lock. must wait.\n", dlm->name,
2182 nodenum, master);
2183 ret = -EAGAIN;
2184 }
2185 spin_unlock(&dlm->spinlock);
2bd63216 2186 mlog(0, "%s: reco lock master is %u\n", dlm->name,
c03872f5
KH		 2187 master);
2188 break;
2189 }
2190 }
2191 return ret;
2192}
2193
ba2bf218
KH		 2194/*
2195 * DLM_DEREF_LOCKRES_MSG
2196 */
2197
2198int dlm_drop_lockres_ref(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
2199{
2200 struct dlm_deref_lockres deref;
2201 int ret = 0, r;
2202 const char *lockname;
2203 unsigned int namelen;
2204
2205 lockname = res->lockname.name;
2206 namelen = res->lockname.len;
2207 BUG_ON(namelen > O2NM_MAX_NAME_LEN);
2208
ba2bf218
KH		 2209 memset(&deref, 0, sizeof(deref));
2210 deref.node_idx = dlm->node_num;
2211 deref.namelen = namelen;
2212 memcpy(deref.name, lockname, namelen);
2213
2214 ret = o2net_send_message(DLM_DEREF_LOCKRES_MSG, dlm->key,
2215 &deref, sizeof(deref), res->owner, &r);
2216 if (ret < 0)
8decab3c
SM		 2217 mlog(ML_ERROR, "%s: res %.*s, error %d send DEREF to node %u\n",
2218 dlm->name, namelen, lockname, ret, res->owner);
ba2bf218
KH		 2219 else if (r < 0) {
2220 /* BAD. other node says I did not have a ref. */
8decab3c
SM		 2221 mlog(ML_ERROR, "%s: res %.*s, DEREF to node %u got %d\n",
2222 dlm->name, namelen, lockname, res->owner, r);
ba2bf218
KH		 2223 dlm_print_one_lock_resource(res);
2224 BUG();
2225 }
2226 return ret;
2227}
2228
d74c9803
KH		 2229int dlm_deref_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
2230 void **ret_data)
ba2bf218
KH		 2231{
2232 struct dlm_ctxt *dlm = data;
2233 struct dlm_deref_lockres *deref = (struct dlm_deref_lockres *)msg->buf;
2234 struct dlm_lock_resource *res = NULL;
2235 char *name;
2236 unsigned int namelen;
2237 int ret = -EINVAL;
2238 u8 node;
2239 unsigned int hash;
f3f85464
SM		 2240 struct dlm_work_item *item;
2241 int cleared = 0;
2242 int dispatch = 0;
ba2bf218
KH		 2243
2244 if (!dlm_grab(dlm))
2245 return 0;
2246
2247 name = deref->name;
2248 namelen = deref->namelen;
2249 node = deref->node_idx;
2250
2251 if (namelen > DLM_LOCKID_NAME_MAX) {
2252 mlog(ML_ERROR, "Invalid name length!");
2253 goto done;
2254 }
2255 if (deref->node_idx >= O2NM_MAX_NODES) {
2256 mlog(ML_ERROR, "Invalid node number: %u\n", node);
2257 goto done;
2258 }
2259
2260 hash = dlm_lockid_hash(name, namelen);
2261
2262 spin_lock(&dlm->spinlock);
2263 res = __dlm_lookup_lockres_full(dlm, name, namelen, hash);
2264 if (!res) {
2265 spin_unlock(&dlm->spinlock);
2266 mlog(ML_ERROR, "%s:%.*s: bad lockres name\n",
2267 dlm->name, namelen, name);
2268 goto done;
2269 }
2270 spin_unlock(&dlm->spinlock);
2271
2272 spin_lock(&res->spinlock);
f3f85464
SM		 2273 if (res->state & DLM_LOCK_RES_SETREF_INPROG)
2274 dispatch = 1;
2275 else {
2276 BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF);
2277 if (test_bit(node, res->refmap)) {
8d400b81 2278 dlm_lockres_clear_refmap_bit(dlm, res, node);
f3f85464
SM		 2279 cleared = 1;
2280 }
ba2bf218
KH		 2281 }
2282 spin_unlock(&res->spinlock);
2283
f3f85464
SM		 2284 if (!dispatch) {
2285 if (cleared)
2286 dlm_lockres_calc_usage(dlm, res);
2287 else {
2288 mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref "
2289 "but it is already dropped!\n", dlm->name,
2290 res->lockname.len, res->lockname.name, node);
2af37ce8 2291 dlm_print_one_lock_resource(res);
f3f85464
SM		 2292 }
2293 ret = 0;
2294 goto done;
2295 }
2296
2297 item = kzalloc(sizeof(*item), GFP_NOFS);
2298 if (!item) {
2299 ret = -ENOMEM;
2300 mlog_errno(ret);
2301 goto done;
2302 }
2303
2304 dlm_init_work_item(dlm, item, dlm_deref_lockres_worker, NULL);
2305 item->u.dl.deref_res = res;
2306 item->u.dl.deref_node = node;
2307
2308 spin_lock(&dlm->work_lock);
2309 list_add_tail(&item->list, &dlm->work_list);
2310 spin_unlock(&dlm->work_lock);
2311
2312 queue_work(dlm->dlm_worker, &dlm->dispatched_work);
2313 return 0;
2314
ba2bf218
KH		 2315done:
2316 if (res)
2317 dlm_lockres_put(res);
2318 dlm_put(dlm);
f3f85464 2319
ba2bf218
KH		 2320 return ret;
2321}
2322
f3f85464
SM		 2323static void dlm_deref_lockres_worker(struct dlm_work_item *item, void *data)
2324{
2325 struct dlm_ctxt *dlm;
2326 struct dlm_lock_resource *res;
2327 u8 node;
2328 u8 cleared = 0;
2329
2330 dlm = item->dlm;
2331 res = item->u.dl.deref_res;
2332 node = item->u.dl.deref_node;
2333
2334 spin_lock(&res->spinlock);
2335 BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF);
2336 if (test_bit(node, res->refmap)) {
2337 __dlm_wait_on_lockres_flags(res, DLM_LOCK_RES_SETREF_INPROG);
8d400b81 2338 dlm_lockres_clear_refmap_bit(dlm, res, node);
f3f85464
SM		 2339 cleared = 1;
2340 }
2341 spin_unlock(&res->spinlock);
2342
2343 if (cleared) {
2344 mlog(0, "%s:%.*s node %u ref dropped in dispatch\n",
2345 dlm->name, res->lockname.len, res->lockname.name, node);
2346 dlm_lockres_calc_usage(dlm, res);
2347 } else {
2348 mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref "
2349 "but it is already dropped!\n", dlm->name,
2350 res->lockname.len, res->lockname.name, node);
2af37ce8 2351 dlm_print_one_lock_resource(res);
f3f85464
SM		 2352 }
2353
2354 dlm_lockres_put(res);
2355}
2356
9f62e960
SM		 2357/*
2358 * A migrateable resource is one that is :
2359 * 1. locally mastered, and,
2360 * 2. zero local locks, and,
2361 * 3. one or more non-local locks, or, one or more references
2362 * Returns 1 if yes, 0 if not.
2f5bf1f2
SM		 2363 */
2364static int dlm_is_lockres_migrateable(struct dlm_ctxt *dlm,
9f62e960 2365 struct dlm_lock_resource *res)
2f5bf1f2 2366{
9f62e960
SM		 2367 enum dlm_lockres_list idx;
2368 int nonlocal = 0, node_ref;
800deef3 2369 struct list_head *queue;
2f5bf1f2 2370 struct dlm_lock *lock;
9f62e960 2371 u64 cookie;
2f5bf1f2
SM		 2372
2373 assert_spin_locked(&res->spinlock);
2374
9f62e960
SM		 2375 if (res->owner != dlm->node_num)
2376 return 0;
2f5bf1f2 2377
9f62e960
SM		 2378 for (idx = DLM_GRANTED_LIST; idx <= DLM_BLOCKED_LIST; idx++) {
2379 queue = dlm_list_idx_to_ptr(res, idx);
800deef3 2380 list_for_each_entry(lock, queue, list) {
9f62e960
SM		 2381 if (lock->ml.node != dlm->node_num) {
2382 nonlocal++;
2383 continue;
2f5bf1f2 2384 }
9f62e960
SM		 2385 cookie = be64_to_cpu(lock->ml.cookie);
2386 mlog(0, "%s: Not migrateable res %.*s, lock %u:%llu on "
2387 "%s list\n", dlm->name, res->lockname.len,
2388 res->lockname.name,
2389 dlm_get_lock_cookie_node(cookie),
2390 dlm_get_lock_cookie_seq(cookie),
2391 dlm_list_in_text(idx));
2392 return 0;
2f5bf1f2 2393 }
2f5bf1f2
SM		 2394 }
2395
9f62e960
SM		 2396 if (!nonlocal) {
2397 node_ref = find_next_bit(res->refmap, O2NM_MAX_NODES, 0);
2398 if (node_ref >= O2NM_MAX_NODES)
2399 return 0;
2400 }
388c4bcb 2401
9f62e960
SM		 2402 mlog(0, "%s: res %.*s, Migrateable\n", dlm->name, res->lockname.len,
2403 res->lockname.name);
2f5bf1f2 2404
9f62e960 2405 return 1;
2f5bf1f2 2406}
6714d8e8
KH		 2407
2408/*
2409 * DLM_MIGRATE_LOCKRES
2410 */
2411
2412
faf0ec9f 2413static int dlm_migrate_lockres(struct dlm_ctxt *dlm,
66effd3c 2414 struct dlm_lock_resource *res, u8 target)
6714d8e8
KH		 2415{
2416 struct dlm_master_list_entry *mle = NULL;
2417 struct dlm_master_list_entry *oldmle = NULL;
2418 struct dlm_migratable_lockres *mres = NULL;
2f5bf1f2 2419 int ret = 0;
6714d8e8
KH		 2420 const char *name;
2421 unsigned int namelen;
2422 int mle_added = 0;
2f5bf1f2 2423 int wake = 0;
6714d8e8
KH		 2424
2425 if (!dlm_grab(dlm))
2426 return -EINVAL;
2427
66effd3c
SM		 2428 BUG_ON(target == O2NM_MAX_NODES);
2429
6714d8e8
KH		 2430 name = res->lockname.name;
2431 namelen = res->lockname.len;
2432
66effd3c
SM		 2433 mlog(0, "%s: Migrating %.*s to node %u\n", dlm->name, namelen, name,
2434 target);
6714d8e8 2435
66effd3c 2436 /* preallocate up front. if this fails, abort */
6714d8e8 2437 ret = -ENOMEM;
ad8100e0 2438 mres = (struct dlm_migratable_lockres *) __get_free_page(GFP_NOFS);
6714d8e8
KH		 2439 if (!mres) {
2440 mlog_errno(ret);
2441 goto leave;
2442 }
2443
3914ed0c 2444 mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
6714d8e8
KH		 2445 if (!mle) {
2446 mlog_errno(ret);
2447 goto leave;
2448 }
2449 ret = 0;
2450
6714d8e8
KH		 2451 /*
2452 * clear any existing master requests and
2453 * add the migration mle to the list
2454 */
66effd3c 2455 spin_lock(&dlm->spinlock);
6714d8e8
KH		 2456 spin_lock(&dlm->master_lock);
2457 ret = dlm_add_migration_mle(dlm, res, mle, &oldmle, name,
2458 namelen, target, dlm->node_num);
2459 spin_unlock(&dlm->master_lock);
2460 spin_unlock(&dlm->spinlock);
2461
2462 if (ret == -EEXIST) {
2463 mlog(0, "another process is already migrating it\n");
2464 goto fail;
2465 }
2466 mle_added = 1;
2467
2468 /*
2469 * set the MIGRATING flag and flush asts
2470 * if we fail after this we need to re-dirty the lockres
2471 */
2472 if (dlm_mark_lockres_migrating(dlm, res, target) < 0) {
2473 mlog(ML_ERROR, "tried to migrate %.*s to %u, but "
2474 "the target went down.\n", res->lockname.len,
2475 res->lockname.name, target);
2476 spin_lock(&res->spinlock);
2477 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 2478 wake = 1;
6714d8e8
KH		 2479 spin_unlock(&res->spinlock);
2480 ret = -EINVAL;
2481 }
2482
2483fail:
2484 if (oldmle) {
2485 /* master is known, detach if not already detached */
2486 dlm_mle_detach_hb_events(dlm, oldmle);
2487 dlm_put_mle(oldmle);
2488 }
2489
2490 if (ret < 0) {
2491 if (mle_added) {
2492 dlm_mle_detach_hb_events(dlm, mle);
2493 dlm_put_mle(mle);
2494 } else if (mle) {
2495 kmem_cache_free(dlm_mle_cache, mle);
66effd3c 2496 mle = NULL;
6714d8e8
KH		 2497 }
2498 goto leave;
2499 }
2500
2501 /*
2502 * at this point, we have a migration target, an mle
2503 * in the master list, and the MIGRATING flag set on
2504 * the lockres
2505 */
2506
1cd04dbe
KH		 2507 /* now that remote nodes are spinning on the MIGRATING flag,
2508 * ensure that all assert_master work is flushed. */
2509 flush_workqueue(dlm->dlm_worker);
6714d8e8
KH		 2510
2511 /* get an extra reference on the mle.
2512 * otherwise the assert_master from the new
2513 * master will destroy this.
2514 * also, make sure that all callers of dlm_get_mle
2515 * take both dlm->spinlock and dlm->master_lock */
2516 spin_lock(&dlm->spinlock);
2517 spin_lock(&dlm->master_lock);
a2bf0477 2518 dlm_get_mle_inuse(mle);
6714d8e8
KH		 2519 spin_unlock(&dlm->master_lock);
2520 spin_unlock(&dlm->spinlock);
2521
2522 /* notify new node and send all lock state */
2523 /* call send_one_lockres with migration flag.
2524 * this serves as notice to the target node that a
2525 * migration is starting. */
2526 ret = dlm_send_one_lockres(dlm, res, mres, target,
2527 DLM_MRES_MIGRATION);
2528
2529 if (ret < 0) {
2530 mlog(0, "migration to node %u failed with %d\n",
2531 target, ret);
2532 /* migration failed, detach and clean up mle */
2533 dlm_mle_detach_hb_events(dlm, mle);
2534 dlm_put_mle(mle);
a2bf0477
KH		 2535 dlm_put_mle_inuse(mle);
2536 spin_lock(&res->spinlock);
2537 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 2538 wake = 1;
a2bf0477 2539 spin_unlock(&res->spinlock);
df016c66
SM		 2540 if (dlm_is_host_down(ret))
2541 dlm_wait_for_node_death(dlm, target,
2542 DLM_NODE_DEATH_WAIT_MAX);
6714d8e8
KH		 2543 goto leave;
2544 }
2545
2546 /* at this point, the target sends a message to all nodes,
2547 * (using dlm_do_migrate_request). this node is skipped since
2548 * we had to put an mle in the list to begin the process. this
2549 * node now waits for target to do an assert master. this node
2550 * will be the last one notified, ensuring that the migration
2551 * is complete everywhere. if the target dies while this is
2552 * going on, some nodes could potentially see the target as the
2553 * master, so it is important that my recovery finds the migration
af901ca1 2554 * mle and sets the master to UNKNOWN. */
6714d8e8
KH		 2555
2556
2557 /* wait for new node to assert master */
2558 while (1) {
2559 ret = wait_event_interruptible_timeout(mle->wq,
2560 (atomic_read(&mle->woken) == 1),
2561 msecs_to_jiffies(5000));
2562
2563 if (ret >= 0) {
2564 if (atomic_read(&mle->woken) == 1 ||
2565 res->owner == target)
2566 break;
2567
1cd04dbe
KH		 2568 mlog(0, "%s:%.*s: timed out during migration\n",
2569 dlm->name, res->lockname.len, res->lockname.name);
2bd63216 2570 /* avoid hang during shutdown when migrating lockres
e2faea4c
KH		 2571 * to a node which also goes down */
2572 if (dlm_is_node_dead(dlm, target)) {
aa852354
KH		 2573 mlog(0, "%s:%.*s: expected migration "
2574 "target %u is no longer up, restarting\n",
e2faea4c
KH		 2575 dlm->name, res->lockname.len,
2576 res->lockname.name, target);
1cd04dbe
KH		 2577 ret = -EINVAL;
2578 /* migration failed, detach and clean up mle */
2579 dlm_mle_detach_hb_events(dlm, mle);
2580 dlm_put_mle(mle);
2581 dlm_put_mle_inuse(mle);
2582 spin_lock(&res->spinlock);
2583 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 2584 wake = 1;
1cd04dbe
KH		 2585 spin_unlock(&res->spinlock);
2586 goto leave;
e2faea4c 2587 }
1cd04dbe
KH		 2588 } else
2589 mlog(0, "%s:%.*s: caught signal during migration\n",
2590 dlm->name, res->lockname.len, res->lockname.name);
6714d8e8
KH		 2591 }
2592
2593 /* all done, set the owner, clear the flag */
2594 spin_lock(&res->spinlock);
2595 dlm_set_lockres_owner(dlm, res, target);
2596 res->state &= ~DLM_LOCK_RES_MIGRATING;
2597 dlm_remove_nonlocal_locks(dlm, res);
2598 spin_unlock(&res->spinlock);
2599 wake_up(&res->wq);
2600
2601 /* master is known, detach if not already detached */
2602 dlm_mle_detach_hb_events(dlm, mle);
a2bf0477 2603 dlm_put_mle_inuse(mle);
6714d8e8
KH		 2604 ret = 0;
2605
2606 dlm_lockres_calc_usage(dlm, res);
2607
2608leave:
2609 /* re-dirty the lockres if we failed */
2610 if (ret < 0)
2611 dlm_kick_thread(dlm, res);
2612
a6fa3640
KH		 2613 /* wake up waiters if the MIGRATING flag got set
2614 * but migration failed */
2615 if (wake)
2616 wake_up(&res->wq);
2617
6714d8e8
KH		 2618 if (mres)
2619 free_page((unsigned long)mres);
2620
2621 dlm_put(dlm);
2622
9f62e960
SM		 2623 mlog(0, "%s: Migrating %.*s to %u, returns %d\n", dlm->name, namelen,
2624 name, target, ret);
6714d8e8
KH		 2625 return ret;
2626}
6714d8e8 2627
ba2bf218
KH		 2628#define DLM_MIGRATION_RETRY_MS 100
2629
9f62e960
SM		 2630/*
2631 * Should be called only after beginning the domain leave process.
ba2bf218
KH		 2632 * There should not be any remaining locks on nonlocal lock resources,
2633 * and there should be no local locks left on locally mastered resources.
2634 *
2635 * Called with the dlm spinlock held, may drop it to do migration, but
2636 * will re-acquire before exit.
2637 *
9f62e960
SM		 2638 * Returns: 1 if dlm->spinlock was dropped/retaken, 0 if never dropped
2639 */
ba2bf218
KH		 2640int dlm_empty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
2641{
66effd3c 2642 int ret;
ba2bf218 2643 int lock_dropped = 0;
66effd3c 2644 u8 target = O2NM_MAX_NODES;
ba2bf218 2645
9f62e960 2646 assert_spin_locked(&dlm->spinlock);
2f5bf1f2 2647
9f62e960 2648 spin_lock(&res->spinlock);
66effd3c
SM		 2649 if (dlm_is_lockres_migrateable(dlm, res))
2650 target = dlm_pick_migration_target(dlm, res);
b36c3f84 2651 spin_unlock(&res->spinlock);
66effd3c
SM		 2652
2653 if (target == O2NM_MAX_NODES)
9f62e960 2654 goto leave;
ba2bf218
KH		 2655
2656 /* Wheee! Migrate lockres here! Will sleep so drop spinlock. */
2657 spin_unlock(&dlm->spinlock);
2658 lock_dropped = 1;
66effd3c
SM		 2659 ret = dlm_migrate_lockres(dlm, res, target);
2660 if (ret)
2661 mlog(0, "%s: res %.*s, Migrate to node %u failed with %d\n",
2662 dlm->name, res->lockname.len, res->lockname.name,
2663 target, ret);
ba2bf218
KH		 2664 spin_lock(&dlm->spinlock);
2665leave:
2666 return lock_dropped;
2667}
2668
6714d8e8
KH		 2669int dlm_lock_basts_flushed(struct dlm_ctxt *dlm, struct dlm_lock *lock)
2670{
2671 int ret;
2672 spin_lock(&dlm->ast_lock);
2673 spin_lock(&lock->spinlock);
2674 ret = (list_empty(&lock->bast_list) && !lock->bast_pending);
2675 spin_unlock(&lock->spinlock);
2676 spin_unlock(&dlm->ast_lock);
2677 return ret;
2678}
2679
2680static int dlm_migration_can_proceed(struct dlm_ctxt *dlm,
2681 struct dlm_lock_resource *res,
2682 u8 mig_target)
2683{
2684 int can_proceed;
2685 spin_lock(&res->spinlock);
2686 can_proceed = !!(res->state & DLM_LOCK_RES_MIGRATING);
2687 spin_unlock(&res->spinlock);
2688
2bd63216 2689 /* target has died, so make the caller break out of the
6714d8e8
KH		 2690 * wait_event, but caller must recheck the domain_map */
2691 spin_lock(&dlm->spinlock);
2692 if (!test_bit(mig_target, dlm->domain_map))
2693 can_proceed = 1;
2694 spin_unlock(&dlm->spinlock);
2695 return can_proceed;
2696}
2697
faf0ec9f
AB		 2698static int dlm_lockres_is_dirty(struct dlm_ctxt *dlm,
2699 struct dlm_lock_resource *res)
6714d8e8
KH		 2700{
2701 int ret;
2702 spin_lock(&res->spinlock);
2703 ret = !!(res->state & DLM_LOCK_RES_DIRTY);
2704 spin_unlock(&res->spinlock);
2705 return ret;
2706}
2707
2708
2709static int dlm_mark_lockres_migrating(struct dlm_ctxt *dlm,
2710 struct dlm_lock_resource *res,
2711 u8 target)
2712{
2713 int ret = 0;
2714
2715 mlog(0, "dlm_mark_lockres_migrating: %.*s, from %u to %u\n",
2716 res->lockname.len, res->lockname.name, dlm->node_num,
2717 target);
2718 /* need to set MIGRATING flag on lockres. this is done by
2719 * ensuring that all asts have been flushed for this lockres. */
2720 spin_lock(&res->spinlock);
2721 BUG_ON(res->migration_pending);
2722 res->migration_pending = 1;
2723 /* strategy is to reserve an extra ast then release
2724 * it below, letting the release do all of the work */
2725 __dlm_lockres_reserve_ast(res);
2726 spin_unlock(&res->spinlock);
2727
ddc09c8d 2728 /* now flush all the pending asts */
6714d8e8 2729 dlm_kick_thread(dlm, res);
ddc09c8d
KH		 2730 /* before waiting on DIRTY, block processes which may
2731 * try to dirty the lockres before MIGRATING is set */
2732 spin_lock(&res->spinlock);
2733 BUG_ON(res->state & DLM_LOCK_RES_BLOCK_DIRTY);
2734 res->state |= DLM_LOCK_RES_BLOCK_DIRTY;
2735 spin_unlock(&res->spinlock);
2736 /* now wait on any pending asts and the DIRTY state */
6714d8e8
KH		 2737 wait_event(dlm->ast_wq, !dlm_lockres_is_dirty(dlm, res));
2738 dlm_lockres_release_ast(dlm, res);
2739
2740 mlog(0, "about to wait on migration_wq, dirty=%s\n",
2741 res->state & DLM_LOCK_RES_DIRTY ? "yes" : "no");
2742 /* if the extra ref we just put was the final one, this
2743 * will pass thru immediately. otherwise, we need to wait
2744 * for the last ast to finish. */
2745again:
2746 ret = wait_event_interruptible_timeout(dlm->migration_wq,
2747 dlm_migration_can_proceed(dlm, res, target),
2748 msecs_to_jiffies(1000));
2749 if (ret < 0) {
2750 mlog(0, "woken again: migrating? %s, dead? %s\n",
2751 res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no",
2752 test_bit(target, dlm->domain_map) ? "no":"yes");
2753 } else {
2754 mlog(0, "all is well: migrating? %s, dead? %s\n",
2755 res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no",
2756 test_bit(target, dlm->domain_map) ? "no":"yes");
2757 }
2758 if (!dlm_migration_can_proceed(dlm, res, target)) {
2759 mlog(0, "trying again...\n");
2760 goto again;
2761 }
2762
a39953dd 2763 ret = 0;
6714d8e8
KH		 2764 /* did the target go down or die? */
2765 spin_lock(&dlm->spinlock);
2766 if (!test_bit(target, dlm->domain_map)) {
2767 mlog(ML_ERROR, "aha. migration target %u just went down\n",
2768 target);
2769 ret = -EHOSTDOWN;
2770 }
2771 spin_unlock(&dlm->spinlock);
2772
a39953dd
WW		 2773 /*
2774 * if target is down, we need to clear DLM_LOCK_RES_BLOCK_DIRTY for
2775 * another try; otherwise, we are sure the MIGRATING state is there,
2776 * drop the unneded state which blocked threads trying to DIRTY
2777 */
2778 spin_lock(&res->spinlock);
2779 BUG_ON(!(res->state & DLM_LOCK_RES_BLOCK_DIRTY));
2780 res->state &= ~DLM_LOCK_RES_BLOCK_DIRTY;
2781 if (!ret)
2782 BUG_ON(!(res->state & DLM_LOCK_RES_MIGRATING));
2783 spin_unlock(&res->spinlock);
2784
6714d8e8
KH		 2785 /*
2786 * at this point:
2787 *
a39953dd 2788 * o the DLM_LOCK_RES_MIGRATING flag is set if target not down
6714d8e8
KH		 2789 * o there are no pending asts on this lockres
2790 * o all processes trying to reserve an ast on this
2791 * lockres must wait for the MIGRATING flag to clear
2792 */
2793 return ret;
2794}
2795
2796/* last step in the migration process.
2797 * original master calls this to free all of the dlm_lock
2798 * structures that used to be for other nodes. */
2799static void dlm_remove_nonlocal_locks(struct dlm_ctxt *dlm,
2800 struct dlm_lock_resource *res)
2801{
6714d8e8 2802 struct list_head *queue = &res->granted;
ba2bf218 2803 int i, bit;
800deef3 2804 struct dlm_lock *lock, *next;
6714d8e8
KH		 2805
2806 assert_spin_locked(&res->spinlock);
2807
2808 BUG_ON(res->owner == dlm->node_num);
2809
2810 for (i=0; i<3; i++) {
800deef3 2811 list_for_each_entry_safe(lock, next, queue, list) {
6714d8e8
KH		 2812 if (lock->ml.node != dlm->node_num) {
2813 mlog(0, "putting lock for node %u\n",
2814 lock->ml.node);
2815 /* be extra careful */
2816 BUG_ON(!list_empty(&lock->ast_list));
2817 BUG_ON(!list_empty(&lock->bast_list));
2818 BUG_ON(lock->ast_pending);
2819 BUG_ON(lock->bast_pending);
8d400b81
SM		 2820 dlm_lockres_clear_refmap_bit(dlm, res,
2821 lock->ml.node);
6714d8e8
KH		 2822 list_del_init(&lock->list);
2823 dlm_lock_put(lock);
2c5c54ac
SM		 2824 /* In a normal unlock, we would have added a
2825 * DLM_UNLOCK_FREE_LOCK action. Force it. */
2826 dlm_lock_put(lock);
6714d8e8
KH		 2827 }
2828 }
2829 queue++;
2830 }
ba2bf218
KH		 2831 bit = 0;
2832 while (1) {
2833 bit = find_next_bit(res->refmap, O2NM_MAX_NODES, bit);
2834 if (bit >= O2NM_MAX_NODES)
2835 break;
2836 /* do not clear the local node reference, if there is a
2837 * process holding this, let it drop the ref itself */
2838 if (bit != dlm->node_num) {
2839 mlog(0, "%s:%.*s: node %u had a ref to this "
2840 "migrating lockres, clearing\n", dlm->name,
2841 res->lockname.len, res->lockname.name, bit);
8d400b81 2842 dlm_lockres_clear_refmap_bit(dlm, res, bit);
ba2bf218
KH		 2843 }
2844 bit++;
2845 }
6714d8e8
KH		 2846}
2847
66effd3c
SM		 2848/*
2849 * Pick a node to migrate the lock resource to. This function selects a
2850 * potential target based first on the locks and then on refmap. It skips
2851 * nodes that are in the process of exiting the domain.
2852 */
6714d8e8
KH		 2853static u8 dlm_pick_migration_target(struct dlm_ctxt *dlm,
2854 struct dlm_lock_resource *res)
2855{
66effd3c 2856 enum dlm_lockres_list idx;
6714d8e8 2857 struct list_head *queue = &res->granted;
6714d8e8 2858 struct dlm_lock *lock;
66effd3c
SM		 2859 int noderef;
2860 u8 nodenum = O2NM_MAX_NODES;
6714d8e8
KH		 2861
2862 assert_spin_locked(&dlm->spinlock);
66effd3c 2863 assert_spin_locked(&res->spinlock);
6714d8e8 2864
66effd3c
SM		 2865 /* Go through all the locks */
2866 for (idx = DLM_GRANTED_LIST; idx <= DLM_BLOCKED_LIST; idx++) {
2867 queue = dlm_list_idx_to_ptr(res, idx);
800deef3 2868 list_for_each_entry(lock, queue, list) {
66effd3c
SM		 2869 if (lock->ml.node == dlm->node_num)
2870 continue;
2871 if (test_bit(lock->ml.node, dlm->exit_domain_map))
2872 continue;
2873 nodenum = lock->ml.node;
2874 goto bail;
6714d8e8 2875 }
6714d8e8 2876 }
388c4bcb 2877
66effd3c
SM		 2878 /* Go thru the refmap */
2879 noderef = -1;
6714d8e8 2880 while (1) {
66effd3c
SM		 2881 noderef = find_next_bit(res->refmap, O2NM_MAX_NODES,
2882 noderef + 1);
2883 if (noderef >= O2NM_MAX_NODES)
6714d8e8 2884 break;
66effd3c
SM		 2885 if (noderef == dlm->node_num)
2886 continue;
2887 if (test_bit(noderef, dlm->exit_domain_map))
2888 continue;
2889 nodenum = noderef;
2890 goto bail;
6714d8e8
KH		 2891 }
2892
66effd3c
SM		 2893bail:
2894 return nodenum;
6714d8e8
KH		 2895}
2896
6714d8e8
KH		 2897/* this is called by the new master once all lockres
2898 * data has been received */
2899static int dlm_do_migrate_request(struct dlm_ctxt *dlm,
2900 struct dlm_lock_resource *res,
2901 u8 master, u8 new_master,
2902 struct dlm_node_iter *iter)
2903{
2904 struct dlm_migrate_request migrate;
2b832564 2905 int ret, skip, status = 0;
6714d8e8
KH		 2906 int nodenum;
2907
2908 memset(&migrate, 0, sizeof(migrate));
2909 migrate.namelen = res->lockname.len;
2910 memcpy(migrate.name, res->lockname.name, migrate.namelen);
2911 migrate.new_master = new_master;
2912 migrate.master = master;
2913
2914 ret = 0;
2915
2916 /* send message to all nodes, except the master and myself */
2917 while ((nodenum = dlm_node_iter_next(iter)) >= 0) {
2918 if (nodenum == master ||
2919 nodenum == new_master)
2920 continue;
2921
2b832564
SM		 2922 /* We could race exit domain. If exited, skip. */
2923 spin_lock(&dlm->spinlock);
2924 skip = (!test_bit(nodenum, dlm->domain_map));
2925 spin_unlock(&dlm->spinlock);
2926 if (skip) {
2927 clear_bit(nodenum, iter->node_map);
2928 continue;
2929 }
2930
6714d8e8
KH		 2931 ret = o2net_send_message(DLM_MIGRATE_REQUEST_MSG, dlm->key,
2932 &migrate, sizeof(migrate), nodenum,
2933 &status);
2b832564 2934 if (ret < 0) {
8decab3c
SM		 2935 mlog(ML_ERROR, "%s: res %.*s, Error %d send "
2936 "MIGRATE_REQUEST to node %u\n", dlm->name,
2937 migrate.namelen, migrate.name, ret, nodenum);
2b832564
SM		 2938 if (!dlm_is_host_down(ret)) {
2939 mlog(ML_ERROR, "unhandled error=%d!\n", ret);
2940 BUG();
2941 }
2942 clear_bit(nodenum, iter->node_map);
2943 ret = 0;
2944 } else if (status < 0) {
6714d8e8
KH		 2945 mlog(0, "migrate request (node %u) returned %d!\n",
2946 nodenum, status);
2947 ret = status;
ba2bf218
KH		 2948 } else if (status == DLM_MIGRATE_RESPONSE_MASTERY_REF) {
2949 /* during the migration request we short-circuited
2950 * the mastery of the lockres. make sure we have
2951 * a mastery ref for nodenum */
2952 mlog(0, "%s:%.*s: need ref for node %u\n",
2953 dlm->name, res->lockname.len, res->lockname.name,
2954 nodenum);
2955 spin_lock(&res->spinlock);
8d400b81 2956 dlm_lockres_set_refmap_bit(dlm, res, nodenum);
ba2bf218 2957 spin_unlock(&res->spinlock);
6714d8e8
KH		 2958 }
2959 }
2960
2961 if (ret < 0)
2962 mlog_errno(ret);
2963
2964 mlog(0, "returning ret=%d\n", ret);
2965 return ret;
2966}
2967
2968
2969/* if there is an existing mle for this lockres, we now know who the master is.
2970 * (the one who sent us *this* message) we can clear it up right away.
2971 * since the process that put the mle on the list still has a reference to it,
2972 * we can unhash it now, set the master and wake the process. as a result,
2973 * we will have no mle in the list to start with. now we can add an mle for
2974 * the migration and this should be the only one found for those scanning the
2975 * list. */
d74c9803
KH		 2976int dlm_migrate_request_handler(struct o2net_msg *msg, u32 len, void *data,
2977 void **ret_data)
6714d8e8
KH		 2978{
2979 struct dlm_ctxt *dlm = data;
2980 struct dlm_lock_resource *res = NULL;
2981 struct dlm_migrate_request *migrate = (struct dlm_migrate_request *) msg->buf;
2982 struct dlm_master_list_entry *mle = NULL, *oldmle = NULL;
2983 const char *name;
a3d33291 2984 unsigned int namelen, hash;
6714d8e8
KH		 2985 int ret = 0;
2986
2987 if (!dlm_grab(dlm))
2988 return -EINVAL;
2989
2990 name = migrate->name;
2991 namelen = migrate->namelen;
a3d33291 2992 hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 2993
2994 /* preallocate.. if this fails, abort */
3914ed0c 2995 mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
6714d8e8
KH		 2996
2997 if (!mle) {
2998 ret = -ENOMEM;
2999 goto leave;
3000 }
3001
3002 /* check for pre-existing lock */
3003 spin_lock(&dlm->spinlock);
a3d33291 3004 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
6714d8e8
KH		 3005 if (res) {
3006 spin_lock(&res->spinlock);
3007 if (res->state & DLM_LOCK_RES_RECOVERING) {
3008 /* if all is working ok, this can only mean that we got
3009 * a migrate request from a node that we now see as
3010 * dead. what can we do here? drop it to the floor? */
3011 spin_unlock(&res->spinlock);
3012 mlog(ML_ERROR, "Got a migrate request, but the "
3013 "lockres is marked as recovering!");
3014 kmem_cache_free(dlm_mle_cache, mle);
3015 ret = -EINVAL; /* need a better solution */
3016 goto unlock;
3017 }
3018 res->state |= DLM_LOCK_RES_MIGRATING;
3019 spin_unlock(&res->spinlock);
3020 }
3021
6d98c3cc 3022 spin_lock(&dlm->master_lock);
6714d8e8
KH		 3023 /* ignore status. only nonzero status would BUG. */
3024 ret = dlm_add_migration_mle(dlm, res, mle, &oldmle,
3025 name, namelen,
3026 migrate->new_master,
3027 migrate->master);
3028
6714d8e8 3029 spin_unlock(&dlm->master_lock);
6d98c3cc 3030unlock:
6714d8e8
KH		 3031 spin_unlock(&dlm->spinlock);
3032
3033 if (oldmle) {
3034 /* master is known, detach if not already detached */
3035 dlm_mle_detach_hb_events(dlm, oldmle);
3036 dlm_put_mle(oldmle);
3037 }
3038
3039 if (res)
3040 dlm_lockres_put(res);
3041leave:
3042 dlm_put(dlm);
3043 return ret;
3044}
3045
3046/* must be holding dlm->spinlock and dlm->master_lock
3047 * when adding a migration mle, we can clear any other mles
3048 * in the master list because we know with certainty that
3049 * the master is "master". so we remove any old mle from
3050 * the list after setting it's master field, and then add
3051 * the new migration mle. this way we can hold with the rule
3052 * of having only one mle for a given lock name at all times. */
3053static int dlm_add_migration_mle(struct dlm_ctxt *dlm,
3054 struct dlm_lock_resource *res,
3055 struct dlm_master_list_entry *mle,
3056 struct dlm_master_list_entry **oldmle,
3057 const char *name, unsigned int namelen,
3058 u8 new_master, u8 master)
3059{
3060 int found;
3061 int ret = 0;
3062
3063 *oldmle = NULL;
3064
6714d8e8
KH		 3065 assert_spin_locked(&dlm->spinlock);
3066 assert_spin_locked(&dlm->master_lock);
3067
3068 /* caller is responsible for any ref taken here on oldmle */
3069 found = dlm_find_mle(dlm, oldmle, (char *)name, namelen);
3070 if (found) {
3071 struct dlm_master_list_entry *tmp = *oldmle;
3072 spin_lock(&tmp->spinlock);
3073 if (tmp->type == DLM_MLE_MIGRATION) {
3074 if (master == dlm->node_num) {
3075 /* ah another process raced me to it */
3076 mlog(0, "tried to migrate %.*s, but some "
3077 "process beat me to it\n",
3078 namelen, name);
3079 ret = -EEXIST;
3080 } else {
3081 /* bad. 2 NODES are trying to migrate! */
3082 mlog(ML_ERROR, "migration error mle: "
3083 "master=%u new_master=%u // request: "
3084 "master=%u new_master=%u // "
3085 "lockres=%.*s\n",
3086 tmp->master, tmp->new_master,
3087 master, new_master,
3088 namelen, name);
3089 BUG();
3090 }
3091 } else {
3092 /* this is essentially what assert_master does */
3093 tmp->master = master;
3094 atomic_set(&tmp->woken, 1);
3095 wake_up(&tmp->wq);
1c084577
SM		 3096 /* remove it so that only one mle will be found */
3097 __dlm_unlink_mle(dlm, tmp);
ba2bf218
KH		 3098 __dlm_mle_detach_hb_events(dlm, tmp);
3099 ret = DLM_MIGRATE_RESPONSE_MASTERY_REF;
3100 mlog(0, "%s:%.*s: master=%u, newmaster=%u, "
3101 "telling master to get ref for cleared out mle "
3102 "during migration\n", dlm->name, namelen, name,
3103 master, new_master);
6714d8e8
KH		 3104 }
3105 spin_unlock(&tmp->spinlock);
3106 }
3107
3108 /* now add a migration mle to the tail of the list */
3109 dlm_init_mle(mle, DLM_MLE_MIGRATION, dlm, res, name, namelen);
3110 mle->new_master = new_master;
ba2bf218
KH		 3111 /* the new master will be sending an assert master for this.
3112 * at that point we will get the refmap reference */
6714d8e8
KH		 3113 mle->master = master;
3114 /* do this for consistency with other mle types */
3115 set_bit(new_master, mle->maybe_map);
1c084577 3116 __dlm_insert_mle(dlm, mle);
6714d8e8
KH		 3117
3118 return ret;
3119}
3120
c2cd4a44
SM		 3121/*
3122 * Sets the owner of the lockres, associated to the mle, to UNKNOWN
3123 */
3124static struct dlm_lock_resource *dlm_reset_mleres_owner(struct dlm_ctxt *dlm,
3125 struct dlm_master_list_entry *mle)
3126{
3127 struct dlm_lock_resource *res;
c2cd4a44
SM		 3128
3129 /* Find the lockres associated to the mle and set its owner to UNK */
7141514b
SM		 3130 res = __dlm_lookup_lockres(dlm, mle->mname, mle->mnamelen,
3131 mle->mnamehash);
c2cd4a44
SM		 3132 if (res) {
3133 spin_unlock(&dlm->master_lock);
3134
3135 /* move lockres onto recovery list */
3136 spin_lock(&res->spinlock);
3137 dlm_set_lockres_owner(dlm, res, DLM_LOCK_RES_OWNER_UNKNOWN);
3138 dlm_move_lockres_to_recovery_list(dlm, res);
3139 spin_unlock(&res->spinlock);
3140 dlm_lockres_put(res);
3141
3142 /* about to get rid of mle, detach from heartbeat */
3143 __dlm_mle_detach_hb_events(dlm, mle);
3144
3145 /* dump the mle */
3146 spin_lock(&dlm->master_lock);
3147 __dlm_put_mle(mle);
3148 spin_unlock(&dlm->master_lock);
3149 }
3150
3151 return res;
3152}
3153
3154static void dlm_clean_migration_mle(struct dlm_ctxt *dlm,
3155 struct dlm_master_list_entry *mle)
3156{
3157 __dlm_mle_detach_hb_events(dlm, mle);
3158
3159 spin_lock(&mle->spinlock);
3160 __dlm_unlink_mle(dlm, mle);
3161 atomic_set(&mle->woken, 1);
3162 spin_unlock(&mle->spinlock);
3163
3164 wake_up(&mle->wq);
3165}
3166
3167static void dlm_clean_block_mle(struct dlm_ctxt *dlm,
3168 struct dlm_master_list_entry *mle, u8 dead_node)
3169{
3170 int bit;
3171
3172 BUG_ON(mle->type != DLM_MLE_BLOCK);
3173
3174 spin_lock(&mle->spinlock);
3175 bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0);
3176 if (bit != dead_node) {
3177 mlog(0, "mle found, but dead node %u would not have been "
3178 "master\n", dead_node);
3179 spin_unlock(&mle->spinlock);
3180 } else {
3181 /* Must drop the refcount by one since the assert_master will
3182 * never arrive. This may result in the mle being unlinked and
3183 * freed, but there may still be a process waiting in the
3184 * dlmlock path which is fine. */
3185 mlog(0, "node %u was expected master\n", dead_node);
3186 atomic_set(&mle->woken, 1);
3187 spin_unlock(&mle->spinlock);
3188 wake_up(&mle->wq);
3189
3190 /* Do not need events any longer, so detach from heartbeat */
3191 __dlm_mle_detach_hb_events(dlm, mle);
3192 __dlm_put_mle(mle);
3193 }
3194}
6714d8e8
KH		 3195
3196void dlm_clean_master_list(struct dlm_ctxt *dlm, u8 dead_node)
3197{
2ed6c750 3198 struct dlm_master_list_entry *mle;
6714d8e8 3199 struct dlm_lock_resource *res;
2ed6c750
SM		 3200 struct hlist_head *bucket;
3201 struct hlist_node *list;
3202 unsigned int i;
6714d8e8 3203
ef6b689b 3204 mlog(0, "dlm=%s, dead node=%u\n", dlm->name, dead_node);
6714d8e8
KH		 3205top:
3206 assert_spin_locked(&dlm->spinlock);
3207
3208 /* clean the master list */
3209 spin_lock(&dlm->master_lock);
2ed6c750
SM		 3210 for (i = 0; i < DLM_HASH_BUCKETS; i++) {
3211 bucket = dlm_master_hash(dlm, i);
3212 hlist_for_each(list, bucket) {
3213 mle = hlist_entry(list, struct dlm_master_list_entry,
3214 master_hash_node);
3215
67ae1f06
SM		 3216 BUG_ON(mle->type != DLM_MLE_BLOCK &&
3217 mle->type != DLM_MLE_MASTER &&
3218 mle->type != DLM_MLE_MIGRATION);
3219
3220 /* MASTER mles are initiated locally. The waiting
3221 * process will notice the node map change shortly.
3222 * Let that happen as normal. */
3223 if (mle->type == DLM_MLE_MASTER)
3224 continue;
3225
3226 /* BLOCK mles are initiated by other nodes. Need to
3227 * clean up if the dead node would have been the
3228 * master. */
3229 if (mle->type == DLM_MLE_BLOCK) {
3230 dlm_clean_block_mle(dlm, mle, dead_node);
3231 continue;
3232 }
6714d8e8 3233
67ae1f06
SM		 3234 /* Everything else is a MIGRATION mle */
3235
3236 /* The rule for MIGRATION mles is that the master
3237 * becomes UNKNOWN if *either* the original or the new
3238 * master dies. All UNKNOWN lockres' are sent to
3239 * whichever node becomes the recovery master. The new
3240 * master is responsible for determining if there is
3241 * still a master for this lockres, or if he needs to
3242 * take over mastery. Either way, this node should
3243 * expect another message to resolve this. */
3244
3245 if (mle->master != dead_node &&
3246 mle->new_master != dead_node)
3247 continue;
3248
3249 /* If we have reached this point, this mle needs to be
3250 * removed from the list and freed. */
3251 dlm_clean_migration_mle(dlm, mle);
3252
3253 mlog(0, "%s: node %u died during migration from "
3254 "%u to %u!\n", dlm->name, dead_node, mle->master,
3255 mle->new_master);
3256
3257 /* If we find a lockres associated with the mle, we've
3258 * hit this rare case that messes up our lock ordering.
3259 * If so, we need to drop the master lock so that we can
3260 * take the lockres lock, meaning that we will have to
3261 * restart from the head of list. */
3262 res = dlm_reset_mleres_owner(dlm, mle);
3263 if (res)
3264 /* restart */
3265 goto top;
3266
3267 /* This may be the last reference */
3268 __dlm_put_mle(mle);
6714d8e8 3269 }
2ed6c750 3270 }
6714d8e8
KH		 3271 spin_unlock(&dlm->master_lock);
3272}
3273
6714d8e8
KH		 3274int dlm_finish_migration(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
3275 u8 old_master)
3276{
3277 struct dlm_node_iter iter;
3278 int ret = 0;
3279
3280 spin_lock(&dlm->spinlock);
3281 dlm_node_iter_init(dlm->domain_map, &iter);
3282 clear_bit(old_master, iter.node_map);
3283 clear_bit(dlm->node_num, iter.node_map);
3284 spin_unlock(&dlm->spinlock);
3285
ba2bf218
KH		 3286 /* ownership of the lockres is changing. account for the
3287 * mastery reference here since old_master will briefly have
3288 * a reference after the migration completes */
3289 spin_lock(&res->spinlock);
8d400b81 3290 dlm_lockres_set_refmap_bit(dlm, res, old_master);
ba2bf218
KH		 3291 spin_unlock(&res->spinlock);
3292
6714d8e8
KH		 3293 mlog(0, "now time to do a migrate request to other nodes\n");
3294 ret = dlm_do_migrate_request(dlm, res, old_master,
3295 dlm->node_num, &iter);
3296 if (ret < 0) {
3297 mlog_errno(ret);
3298 goto leave;
3299 }
3300
3301 mlog(0, "doing assert master of %.*s to all except the original node\n",
3302 res->lockname.len, res->lockname.name);
3303 /* this call now finishes out the nodemap
3304 * even if one or more nodes die */
ba2bf218 3305 ret = dlm_do_assert_master(dlm, res, iter.node_map,
6714d8e8
KH		 3306 DLM_ASSERT_MASTER_FINISH_MIGRATION);
3307 if (ret < 0) {
3308 /* no longer need to retry. all living nodes contacted. */
3309 mlog_errno(ret);
3310 ret = 0;
3311 }
3312
3313 memset(iter.node_map, 0, sizeof(iter.node_map));
3314 set_bit(old_master, iter.node_map);
3315 mlog(0, "doing assert master of %.*s back to %u\n",
3316 res->lockname.len, res->lockname.name, old_master);
ba2bf218 3317 ret = dlm_do_assert_master(dlm, res, iter.node_map,
6714d8e8
KH		 3318 DLM_ASSERT_MASTER_FINISH_MIGRATION);
3319 if (ret < 0) {
3320 mlog(0, "assert master to original master failed "
3321 "with %d.\n", ret);
3322 /* the only nonzero status here would be because of
3323 * a dead original node. we're done. */
3324 ret = 0;
3325 }
3326
3327 /* all done, set the owner, clear the flag */
3328 spin_lock(&res->spinlock);
3329 dlm_set_lockres_owner(dlm, res, dlm->node_num);
3330 res->state &= ~DLM_LOCK_RES_MIGRATING;
3331 spin_unlock(&res->spinlock);
3332 /* re-dirty it on the new master */
3333 dlm_kick_thread(dlm, res);
3334 wake_up(&res->wq);
3335leave:
3336 return ret;
3337}
3338
3339/*
3340 * LOCKRES AST REFCOUNT
3341 * this is integral to migration
3342 */
3343
3344/* for future intent to call an ast, reserve one ahead of time.
3345 * this should be called only after waiting on the lockres
3346 * with dlm_wait_on_lockres, and while still holding the
3347 * spinlock after the call. */
3348void __dlm_lockres_reserve_ast(struct dlm_lock_resource *res)
3349{
3350 assert_spin_locked(&res->spinlock);
3351 if (res->state & DLM_LOCK_RES_MIGRATING) {
3352 __dlm_print_one_lock_resource(res);
3353 }
3354 BUG_ON(res->state & DLM_LOCK_RES_MIGRATING);
3355
3356 atomic_inc(&res->asts_reserved);
3357}
3358
3359/*
3360 * used to drop the reserved ast, either because it went unused,
3361 * or because the ast/bast was actually called.
3362 *
3363 * also, if there is a pending migration on this lockres,
3364 * and this was the last pending ast on the lockres,
3365 * atomically set the MIGRATING flag before we drop the lock.
3366 * this is how we ensure that migration can proceed with no
3367 * asts in progress. note that it is ok if the state of the
3368 * queues is such that a lock should be granted in the future
3369 * or that a bast should be fired, because the new master will
3370 * shuffle the lists on this lockres as soon as it is migrated.
3371 */
3372void dlm_lockres_release_ast(struct dlm_ctxt *dlm,
3373 struct dlm_lock_resource *res)
3374{
3375 if (!atomic_dec_and_lock(&res->asts_reserved, &res->spinlock))
3376 return;
3377
3378 if (!res->migration_pending) {
3379 spin_unlock(&res->spinlock);
3380 return;
3381 }
3382
3383 BUG_ON(res->state & DLM_LOCK_RES_MIGRATING);
3384 res->migration_pending = 0;
3385 res->state |= DLM_LOCK_RES_MIGRATING;
3386 spin_unlock(&res->spinlock);
3387 wake_up(&res->wq);
3388 wake_up(&dlm->migration_wq);
3389}
5dad6c39
SE		 3390
3391void dlm_force_free_mles(struct dlm_ctxt *dlm)
3392{
3393 int i;
3394 struct hlist_head *bucket;
3395 struct dlm_master_list_entry *mle;
3396 struct hlist_node *tmp, *list;
3397
3398 /*
3399 * We notified all other nodes that we are exiting the domain and
3400 * marked the dlm state to DLM_CTXT_LEAVING. If any mles are still
3401 * around we force free them and wake any processes that are waiting
3402 * on the mles
3403 */
3404 spin_lock(&dlm->spinlock);
3405 spin_lock(&dlm->master_lock);
3406
3407 BUG_ON(dlm->dlm_state != DLM_CTXT_LEAVING);
3408 BUG_ON((find_next_bit(dlm->domain_map, O2NM_MAX_NODES, 0) < O2NM_MAX_NODES));
3409
3410 for (i = 0; i < DLM_HASH_BUCKETS; i++) {
3411 bucket = dlm_master_hash(dlm, i);
3412 hlist_for_each_safe(list, tmp, bucket) {
3413 mle = hlist_entry(list, struct dlm_master_list_entry,
3414 master_hash_node);
3415 if (mle->type != DLM_MLE_BLOCK) {
3416 mlog(ML_ERROR, "bad mle: %p\n", mle);
3417 dlm_print_one_mle(mle);
3418 }
3419 atomic_set(&mle->woken, 1);
3420 wake_up(&mle->wq);
3421
3422 __dlm_unlink_mle(dlm, mle);
3423 __dlm_mle_detach_hb_events(dlm, mle);
3424 __dlm_put_mle(mle);
3425 }
3426 }
3427 spin_unlock(&dlm->master_lock);
3428 spin_unlock(&dlm->spinlock);
3429}
kernel source for telekom puls (alcatel/mediatek)