ocfs2_dlm: Calling post handler function in assert master handler
[deliverable/linux.git] / fs / ocfs2 / dlm / dlmmaster.c
CommitLineData
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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>
33#include <linux/utsname.h>
34#include <linux/init.h>
35#include <linux/sysctl.h>
36#include <linux/random.h>
37#include <linux/blkdev.h>
38#include <linux/socket.h>
39#include <linux/inet.h>
40#include <linux/spinlock.h>
41#include <linux/delay.h>
42
43
44#include "cluster/heartbeat.h"
45#include "cluster/nodemanager.h"
46#include "cluster/tcp.h"
47
48#include "dlmapi.h"
49#include "dlmcommon.h"
82353b59 50#include "dlmdomain.h"
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51
52#define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_MASTER)
53#include "cluster/masklog.h"
54
55enum dlm_mle_type {
56 DLM_MLE_BLOCK,
57 DLM_MLE_MASTER,
58 DLM_MLE_MIGRATION
59};
60
61struct dlm_lock_name
62{
63 u8 len;
64 u8 name[DLM_LOCKID_NAME_MAX];
65};
66
67struct dlm_master_list_entry
68{
69 struct list_head list;
70 struct list_head hb_events;
71 struct dlm_ctxt *dlm;
72 spinlock_t spinlock;
73 wait_queue_head_t wq;
74 atomic_t woken;
75 struct kref mle_refs;
a2bf0477 76 int inuse;
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77 unsigned long maybe_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
78 unsigned long vote_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
79 unsigned long response_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
80 unsigned long node_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
81 u8 master;
82 u8 new_master;
83 enum dlm_mle_type type;
84 struct o2hb_callback_func mle_hb_up;
85 struct o2hb_callback_func mle_hb_down;
86 union {
87 struct dlm_lock_resource *res;
88 struct dlm_lock_name name;
89 } u;
90};
91
92static void dlm_mle_node_down(struct dlm_ctxt *dlm,
93 struct dlm_master_list_entry *mle,
94 struct o2nm_node *node,
95 int idx);
96static void dlm_mle_node_up(struct dlm_ctxt *dlm,
97 struct dlm_master_list_entry *mle,
98 struct o2nm_node *node,
99 int idx);
100
101static void dlm_assert_master_worker(struct dlm_work_item *item, void *data);
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102static int dlm_do_assert_master(struct dlm_ctxt *dlm,
103 struct dlm_lock_resource *res,
104 void *nodemap, u32 flags);
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105
106static inline int dlm_mle_equal(struct dlm_ctxt *dlm,
107 struct dlm_master_list_entry *mle,
108 const char *name,
109 unsigned int namelen)
110{
111 struct dlm_lock_resource *res;
112
113 if (dlm != mle->dlm)
114 return 0;
115
116 if (mle->type == DLM_MLE_BLOCK ||
117 mle->type == DLM_MLE_MIGRATION) {
118 if (namelen != mle->u.name.len ||
119 memcmp(name, mle->u.name.name, namelen)!=0)
120 return 0;
121 } else {
122 res = mle->u.res;
123 if (namelen != res->lockname.len ||
124 memcmp(res->lockname.name, name, namelen) != 0)
125 return 0;
126 }
127 return 1;
128}
129
95883719 130#define dlm_print_nodemap(m) _dlm_print_nodemap(m,#m)
8a9343fa 131static void _dlm_print_nodemap(unsigned long *map, const char *mapname)
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132{
133 int i;
134 printk("%s=[ ", mapname);
135 for (i=0; i<O2NM_MAX_NODES; i++)
136 if (test_bit(i, map))
137 printk("%d ", i);
138 printk("]");
139}
140
8a9343fa 141static void dlm_print_one_mle(struct dlm_master_list_entry *mle)
6714d8e8 142{
95883719 143 int refs;
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144 char *type;
145 char attached;
146 u8 master;
147 unsigned int namelen;
148 const char *name;
149 struct kref *k;
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150 unsigned long *maybe = mle->maybe_map,
151 *vote = mle->vote_map,
152 *resp = mle->response_map,
153 *node = mle->node_map;
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154
155 k = &mle->mle_refs;
156 if (mle->type == DLM_MLE_BLOCK)
157 type = "BLK";
158 else if (mle->type == DLM_MLE_MASTER)
159 type = "MAS";
160 else
161 type = "MIG";
162 refs = atomic_read(&k->refcount);
163 master = mle->master;
164 attached = (list_empty(&mle->hb_events) ? 'N' : 'Y');
165
166 if (mle->type != DLM_MLE_MASTER) {
167 namelen = mle->u.name.len;
168 name = mle->u.name.name;
169 } else {
170 namelen = mle->u.res->lockname.len;
171 name = mle->u.res->lockname.name;
172 }
173
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174 mlog(ML_NOTICE, "%.*s: %3s refs=%3d mas=%3u new=%3u evt=%c inuse=%d ",
175 namelen, name, type, refs, master, mle->new_master, attached,
176 mle->inuse);
177 dlm_print_nodemap(maybe);
178 printk(", ");
179 dlm_print_nodemap(vote);
180 printk(", ");
181 dlm_print_nodemap(resp);
182 printk(", ");
183 dlm_print_nodemap(node);
184 printk(", ");
185 printk("\n");
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186}
187
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188#if 0
189/* Code here is included but defined out as it aids debugging */
190
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191static void dlm_dump_mles(struct dlm_ctxt *dlm)
192{
193 struct dlm_master_list_entry *mle;
194 struct list_head *iter;
195
196 mlog(ML_NOTICE, "dumping all mles for domain %s:\n", dlm->name);
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197 spin_lock(&dlm->master_lock);
198 list_for_each(iter, &dlm->master_list) {
199 mle = list_entry(iter, struct dlm_master_list_entry, list);
200 dlm_print_one_mle(mle);
201 }
202 spin_unlock(&dlm->master_lock);
203}
204
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205int dlm_dump_all_mles(const char __user *data, unsigned int len)
206{
207 struct list_head *iter;
208 struct dlm_ctxt *dlm;
209
210 spin_lock(&dlm_domain_lock);
211 list_for_each(iter, &dlm_domains) {
212 dlm = list_entry (iter, struct dlm_ctxt, list);
213 mlog(ML_NOTICE, "found dlm: %p, name=%s\n", dlm, dlm->name);
214 dlm_dump_mles(dlm);
215 }
216 spin_unlock(&dlm_domain_lock);
217 return len;
218}
219EXPORT_SYMBOL_GPL(dlm_dump_all_mles);
220
221#endif /* 0 */
222
223
e18b890b 224static struct kmem_cache *dlm_mle_cache = NULL;
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225
226
227static void dlm_mle_release(struct kref *kref);
228static void dlm_init_mle(struct dlm_master_list_entry *mle,
229 enum dlm_mle_type type,
230 struct dlm_ctxt *dlm,
231 struct dlm_lock_resource *res,
232 const char *name,
233 unsigned int namelen);
234static void dlm_put_mle(struct dlm_master_list_entry *mle);
235static void __dlm_put_mle(struct dlm_master_list_entry *mle);
236static int dlm_find_mle(struct dlm_ctxt *dlm,
237 struct dlm_master_list_entry **mle,
238 char *name, unsigned int namelen);
239
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240static int dlm_do_master_request(struct dlm_lock_resource *res,
241 struct dlm_master_list_entry *mle, int to);
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242
243
244static int dlm_wait_for_lock_mastery(struct dlm_ctxt *dlm,
245 struct dlm_lock_resource *res,
246 struct dlm_master_list_entry *mle,
247 int *blocked);
248static int dlm_restart_lock_mastery(struct dlm_ctxt *dlm,
249 struct dlm_lock_resource *res,
250 struct dlm_master_list_entry *mle,
251 int blocked);
252static int dlm_add_migration_mle(struct dlm_ctxt *dlm,
253 struct dlm_lock_resource *res,
254 struct dlm_master_list_entry *mle,
255 struct dlm_master_list_entry **oldmle,
256 const char *name, unsigned int namelen,
257 u8 new_master, u8 master);
258
259static u8 dlm_pick_migration_target(struct dlm_ctxt *dlm,
260 struct dlm_lock_resource *res);
261static void dlm_remove_nonlocal_locks(struct dlm_ctxt *dlm,
262 struct dlm_lock_resource *res);
263static int dlm_mark_lockres_migrating(struct dlm_ctxt *dlm,
264 struct dlm_lock_resource *res,
265 u8 target);
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266static int dlm_pre_master_reco_lockres(struct dlm_ctxt *dlm,
267 struct dlm_lock_resource *res);
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268
269
270int dlm_is_host_down(int errno)
271{
272 switch (errno) {
273 case -EBADF:
274 case -ECONNREFUSED:
275 case -ENOTCONN:
276 case -ECONNRESET:
277 case -EPIPE:
278 case -EHOSTDOWN:
279 case -EHOSTUNREACH:
280 case -ETIMEDOUT:
281 case -ECONNABORTED:
282 case -ENETDOWN:
283 case -ENETUNREACH:
284 case -ENETRESET:
285 case -ESHUTDOWN:
286 case -ENOPROTOOPT:
287 case -EINVAL: /* if returned from our tcp code,
288 this means there is no socket */
289 return 1;
290 }
291 return 0;
292}
293
294
295/*
296 * MASTER LIST FUNCTIONS
297 */
298
299
300/*
301 * regarding master list entries and heartbeat callbacks:
302 *
303 * in order to avoid sleeping and allocation that occurs in
304 * heartbeat, master list entries are simply attached to the
305 * dlm's established heartbeat callbacks. the mle is attached
306 * when it is created, and since the dlm->spinlock is held at
307 * that time, any heartbeat event will be properly discovered
308 * by the mle. the mle needs to be detached from the
309 * dlm->mle_hb_events list as soon as heartbeat events are no
310 * longer useful to the mle, and before the mle is freed.
311 *
312 * as a general rule, heartbeat events are no longer needed by
313 * the mle once an "answer" regarding the lock master has been
314 * received.
315 */
316static inline void __dlm_mle_attach_hb_events(struct dlm_ctxt *dlm,
317 struct dlm_master_list_entry *mle)
318{
319 assert_spin_locked(&dlm->spinlock);
320
321 list_add_tail(&mle->hb_events, &dlm->mle_hb_events);
322}
323
324
325static inline void __dlm_mle_detach_hb_events(struct dlm_ctxt *dlm,
326 struct dlm_master_list_entry *mle)
327{
328 if (!list_empty(&mle->hb_events))
329 list_del_init(&mle->hb_events);
330}
331
332
333static inline void dlm_mle_detach_hb_events(struct dlm_ctxt *dlm,
334 struct dlm_master_list_entry *mle)
335{
336 spin_lock(&dlm->spinlock);
337 __dlm_mle_detach_hb_events(dlm, mle);
338 spin_unlock(&dlm->spinlock);
339}
340
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341static void dlm_get_mle_inuse(struct dlm_master_list_entry *mle)
342{
343 struct dlm_ctxt *dlm;
344 dlm = mle->dlm;
345
346 assert_spin_locked(&dlm->spinlock);
347 assert_spin_locked(&dlm->master_lock);
348 mle->inuse++;
349 kref_get(&mle->mle_refs);
350}
351
352static void dlm_put_mle_inuse(struct dlm_master_list_entry *mle)
353{
354 struct dlm_ctxt *dlm;
355 dlm = mle->dlm;
356
357 spin_lock(&dlm->spinlock);
358 spin_lock(&dlm->master_lock);
359 mle->inuse--;
360 __dlm_put_mle(mle);
361 spin_unlock(&dlm->master_lock);
362 spin_unlock(&dlm->spinlock);
363
364}
365
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366/* remove from list and free */
367static void __dlm_put_mle(struct dlm_master_list_entry *mle)
368{
369 struct dlm_ctxt *dlm;
370 dlm = mle->dlm;
371
372 assert_spin_locked(&dlm->spinlock);
373 assert_spin_locked(&dlm->master_lock);
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374 if (!atomic_read(&mle->mle_refs.refcount)) {
375 /* this may or may not crash, but who cares.
376 * it's a BUG. */
377 mlog(ML_ERROR, "bad mle: %p\n", mle);
378 dlm_print_one_mle(mle);
379 BUG();
380 } else
381 kref_put(&mle->mle_refs, dlm_mle_release);
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382}
383
384
385/* must not have any spinlocks coming in */
386static void dlm_put_mle(struct dlm_master_list_entry *mle)
387{
388 struct dlm_ctxt *dlm;
389 dlm = mle->dlm;
390
391 spin_lock(&dlm->spinlock);
392 spin_lock(&dlm->master_lock);
393 __dlm_put_mle(mle);
394 spin_unlock(&dlm->master_lock);
395 spin_unlock(&dlm->spinlock);
396}
397
398static inline void dlm_get_mle(struct dlm_master_list_entry *mle)
399{
400 kref_get(&mle->mle_refs);
401}
402
403static void dlm_init_mle(struct dlm_master_list_entry *mle,
404 enum dlm_mle_type type,
405 struct dlm_ctxt *dlm,
406 struct dlm_lock_resource *res,
407 const char *name,
408 unsigned int namelen)
409{
410 assert_spin_locked(&dlm->spinlock);
411
412 mle->dlm = dlm;
413 mle->type = type;
414 INIT_LIST_HEAD(&mle->list);
415 INIT_LIST_HEAD(&mle->hb_events);
416 memset(mle->maybe_map, 0, sizeof(mle->maybe_map));
417 spin_lock_init(&mle->spinlock);
418 init_waitqueue_head(&mle->wq);
419 atomic_set(&mle->woken, 0);
420 kref_init(&mle->mle_refs);
421 memset(mle->response_map, 0, sizeof(mle->response_map));
422 mle->master = O2NM_MAX_NODES;
423 mle->new_master = O2NM_MAX_NODES;
a2bf0477 424 mle->inuse = 0;
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425
426 if (mle->type == DLM_MLE_MASTER) {
427 BUG_ON(!res);
428 mle->u.res = res;
429 } else if (mle->type == DLM_MLE_BLOCK) {
430 BUG_ON(!name);
431 memcpy(mle->u.name.name, name, namelen);
432 mle->u.name.len = namelen;
433 } else /* DLM_MLE_MIGRATION */ {
434 BUG_ON(!name);
435 memcpy(mle->u.name.name, name, namelen);
436 mle->u.name.len = namelen;
437 }
438
439 /* copy off the node_map and register hb callbacks on our copy */
440 memcpy(mle->node_map, dlm->domain_map, sizeof(mle->node_map));
441 memcpy(mle->vote_map, dlm->domain_map, sizeof(mle->vote_map));
442 clear_bit(dlm->node_num, mle->vote_map);
443 clear_bit(dlm->node_num, mle->node_map);
444
445 /* attach the mle to the domain node up/down events */
446 __dlm_mle_attach_hb_events(dlm, mle);
447}
448
449
450/* returns 1 if found, 0 if not */
451static int dlm_find_mle(struct dlm_ctxt *dlm,
452 struct dlm_master_list_entry **mle,
453 char *name, unsigned int namelen)
454{
455 struct dlm_master_list_entry *tmpmle;
456 struct list_head *iter;
457
458 assert_spin_locked(&dlm->master_lock);
459
460 list_for_each(iter, &dlm->master_list) {
461 tmpmle = list_entry(iter, struct dlm_master_list_entry, list);
462 if (!dlm_mle_equal(dlm, tmpmle, name, namelen))
463 continue;
464 dlm_get_mle(tmpmle);
465 *mle = tmpmle;
466 return 1;
467 }
468 return 0;
469}
470
471void dlm_hb_event_notify_attached(struct dlm_ctxt *dlm, int idx, int node_up)
472{
473 struct dlm_master_list_entry *mle;
474 struct list_head *iter;
475
476 assert_spin_locked(&dlm->spinlock);
477
478 list_for_each(iter, &dlm->mle_hb_events) {
479 mle = list_entry(iter, struct dlm_master_list_entry,
480 hb_events);
481 if (node_up)
482 dlm_mle_node_up(dlm, mle, NULL, idx);
483 else
484 dlm_mle_node_down(dlm, mle, NULL, idx);
485 }
486}
487
488static void dlm_mle_node_down(struct dlm_ctxt *dlm,
489 struct dlm_master_list_entry *mle,
490 struct o2nm_node *node, int idx)
491{
492 spin_lock(&mle->spinlock);
493
494 if (!test_bit(idx, mle->node_map))
495 mlog(0, "node %u already removed from nodemap!\n", idx);
496 else
497 clear_bit(idx, mle->node_map);
498
499 spin_unlock(&mle->spinlock);
500}
501
502static void dlm_mle_node_up(struct dlm_ctxt *dlm,
503 struct dlm_master_list_entry *mle,
504 struct o2nm_node *node, int idx)
505{
506 spin_lock(&mle->spinlock);
507
508 if (test_bit(idx, mle->node_map))
509 mlog(0, "node %u already in node map!\n", idx);
510 else
511 set_bit(idx, mle->node_map);
512
513 spin_unlock(&mle->spinlock);
514}
515
516
517int dlm_init_mle_cache(void)
518{
519 dlm_mle_cache = kmem_cache_create("dlm_mle_cache",
520 sizeof(struct dlm_master_list_entry),
521 0, SLAB_HWCACHE_ALIGN,
522 NULL, NULL);
523 if (dlm_mle_cache == NULL)
524 return -ENOMEM;
525 return 0;
526}
527
528void dlm_destroy_mle_cache(void)
529{
530 if (dlm_mle_cache)
531 kmem_cache_destroy(dlm_mle_cache);
532}
533
534static void dlm_mle_release(struct kref *kref)
535{
536 struct dlm_master_list_entry *mle;
537 struct dlm_ctxt *dlm;
538
539 mlog_entry_void();
540
541 mle = container_of(kref, struct dlm_master_list_entry, mle_refs);
542 dlm = mle->dlm;
543
544 if (mle->type != DLM_MLE_MASTER) {
545 mlog(0, "calling mle_release for %.*s, type %d\n",
546 mle->u.name.len, mle->u.name.name, mle->type);
547 } else {
548 mlog(0, "calling mle_release for %.*s, type %d\n",
549 mle->u.res->lockname.len,
550 mle->u.res->lockname.name, mle->type);
551 }
552 assert_spin_locked(&dlm->spinlock);
553 assert_spin_locked(&dlm->master_lock);
554
555 /* remove from list if not already */
556 if (!list_empty(&mle->list))
557 list_del_init(&mle->list);
558
559 /* detach the mle from the domain node up/down events */
560 __dlm_mle_detach_hb_events(dlm, mle);
561
562 /* NOTE: kfree under spinlock here.
563 * if this is bad, we can move this to a freelist. */
564 kmem_cache_free(dlm_mle_cache, mle);
565}
566
567
568/*
569 * LOCK RESOURCE FUNCTIONS
570 */
571
572static void dlm_set_lockres_owner(struct dlm_ctxt *dlm,
573 struct dlm_lock_resource *res,
574 u8 owner)
575{
576 assert_spin_locked(&res->spinlock);
577
578 mlog_entry("%.*s, %u\n", res->lockname.len, res->lockname.name, owner);
579
580 if (owner == dlm->node_num)
581 atomic_inc(&dlm->local_resources);
582 else if (owner == DLM_LOCK_RES_OWNER_UNKNOWN)
583 atomic_inc(&dlm->unknown_resources);
584 else
585 atomic_inc(&dlm->remote_resources);
586
587 res->owner = owner;
588}
589
590void dlm_change_lockres_owner(struct dlm_ctxt *dlm,
591 struct dlm_lock_resource *res, u8 owner)
592{
593 assert_spin_locked(&res->spinlock);
594
595 if (owner == res->owner)
596 return;
597
598 if (res->owner == dlm->node_num)
599 atomic_dec(&dlm->local_resources);
600 else if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN)
601 atomic_dec(&dlm->unknown_resources);
602 else
603 atomic_dec(&dlm->remote_resources);
604
605 dlm_set_lockres_owner(dlm, res, owner);
606}
607
608
609static void dlm_lockres_release(struct kref *kref)
610{
611 struct dlm_lock_resource *res;
612
613 res = container_of(kref, struct dlm_lock_resource, refs);
614
615 /* This should not happen -- all lockres' have a name
616 * associated with them at init time. */
617 BUG_ON(!res->lockname.name);
618
619 mlog(0, "destroying lockres %.*s\n", res->lockname.len,
620 res->lockname.name);
621
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622 if (!hlist_unhashed(&res->hash_node) ||
623 !list_empty(&res->granted) ||
624 !list_empty(&res->converting) ||
625 !list_empty(&res->blocked) ||
626 !list_empty(&res->dirty) ||
627 !list_empty(&res->recovering) ||
628 !list_empty(&res->purge)) {
629 mlog(ML_ERROR,
630 "Going to BUG for resource %.*s."
631 " We're on a list! [%c%c%c%c%c%c%c]\n",
632 res->lockname.len, res->lockname.name,
633 !hlist_unhashed(&res->hash_node) ? 'H' : ' ',
634 !list_empty(&res->granted) ? 'G' : ' ',
635 !list_empty(&res->converting) ? 'C' : ' ',
636 !list_empty(&res->blocked) ? 'B' : ' ',
637 !list_empty(&res->dirty) ? 'D' : ' ',
638 !list_empty(&res->recovering) ? 'R' : ' ',
639 !list_empty(&res->purge) ? 'P' : ' ');
640
641 dlm_print_one_lock_resource(res);
642 }
643
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644 /* By the time we're ready to blow this guy away, we shouldn't
645 * be on any lists. */
81f2094a 646 BUG_ON(!hlist_unhashed(&res->hash_node));
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647 BUG_ON(!list_empty(&res->granted));
648 BUG_ON(!list_empty(&res->converting));
649 BUG_ON(!list_empty(&res->blocked));
650 BUG_ON(!list_empty(&res->dirty));
651 BUG_ON(!list_empty(&res->recovering));
652 BUG_ON(!list_empty(&res->purge));
653
654 kfree(res->lockname.name);
655
656 kfree(res);
657}
658
6714d8e8
KH
659void dlm_lockres_put(struct dlm_lock_resource *res)
660{
661 kref_put(&res->refs, dlm_lockres_release);
662}
663
664static void dlm_init_lockres(struct dlm_ctxt *dlm,
665 struct dlm_lock_resource *res,
666 const char *name, unsigned int namelen)
667{
668 char *qname;
669
670 /* If we memset here, we lose our reference to the kmalloc'd
671 * res->lockname.name, so be sure to init every field
672 * correctly! */
673
674 qname = (char *) res->lockname.name;
675 memcpy(qname, name, namelen);
676
677 res->lockname.len = namelen;
a3d33291 678 res->lockname.hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH
679
680 init_waitqueue_head(&res->wq);
681 spin_lock_init(&res->spinlock);
81f2094a 682 INIT_HLIST_NODE(&res->hash_node);
6714d8e8
KH
683 INIT_LIST_HEAD(&res->granted);
684 INIT_LIST_HEAD(&res->converting);
685 INIT_LIST_HEAD(&res->blocked);
686 INIT_LIST_HEAD(&res->dirty);
687 INIT_LIST_HEAD(&res->recovering);
688 INIT_LIST_HEAD(&res->purge);
689 atomic_set(&res->asts_reserved, 0);
690 res->migration_pending = 0;
ba2bf218 691 res->inflight_locks = 0;
6714d8e8
KH
692
693 kref_init(&res->refs);
694
695 /* just for consistency */
696 spin_lock(&res->spinlock);
697 dlm_set_lockres_owner(dlm, res, DLM_LOCK_RES_OWNER_UNKNOWN);
698 spin_unlock(&res->spinlock);
699
700 res->state = DLM_LOCK_RES_IN_PROGRESS;
701
702 res->last_used = 0;
703
704 memset(res->lvb, 0, DLM_LVB_LEN);
ba2bf218 705 memset(res->refmap, 0, sizeof(res->refmap));
6714d8e8
KH
706}
707
708struct dlm_lock_resource *dlm_new_lockres(struct dlm_ctxt *dlm,
709 const char *name,
710 unsigned int namelen)
711{
712 struct dlm_lock_resource *res;
713
ad8100e0 714 res = kmalloc(sizeof(struct dlm_lock_resource), GFP_NOFS);
6714d8e8
KH
715 if (!res)
716 return NULL;
717
ad8100e0 718 res->lockname.name = kmalloc(namelen, GFP_NOFS);
6714d8e8
KH
719 if (!res->lockname.name) {
720 kfree(res);
721 return NULL;
722 }
723
724 dlm_init_lockres(dlm, res, name, namelen);
725 return res;
726}
727
ba2bf218
KH
728void __dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm,
729 struct dlm_lock_resource *res,
730 int new_lockres,
731 const char *file,
732 int line)
733{
734 if (!new_lockres)
735 assert_spin_locked(&res->spinlock);
736
737 if (!test_bit(dlm->node_num, res->refmap)) {
738 BUG_ON(res->inflight_locks != 0);
739 dlm_lockres_set_refmap_bit(dlm->node_num, res);
740 }
741 res->inflight_locks++;
742 mlog(0, "%s:%.*s: inflight++: now %u\n",
743 dlm->name, res->lockname.len, res->lockname.name,
744 res->inflight_locks);
745}
746
747void __dlm_lockres_drop_inflight_ref(struct dlm_ctxt *dlm,
748 struct dlm_lock_resource *res,
749 const char *file,
750 int line)
751{
752 assert_spin_locked(&res->spinlock);
753
754 BUG_ON(res->inflight_locks == 0);
755 res->inflight_locks--;
756 mlog(0, "%s:%.*s: inflight--: now %u\n",
757 dlm->name, res->lockname.len, res->lockname.name,
758 res->inflight_locks);
759 if (res->inflight_locks == 0)
760 dlm_lockres_clear_refmap_bit(dlm->node_num, res);
761 wake_up(&res->wq);
762}
763
6714d8e8
KH
764/*
765 * lookup a lock resource by name.
766 * may already exist in the hashtable.
767 * lockid is null terminated
768 *
769 * if not, allocate enough for the lockres and for
770 * the temporary structure used in doing the mastering.
771 *
772 * also, do a lookup in the dlm->master_list to see
773 * if another node has begun mastering the same lock.
774 * if so, there should be a block entry in there
775 * for this name, and we should *not* attempt to master
776 * the lock here. need to wait around for that node
777 * to assert_master (or die).
778 *
779 */
780struct dlm_lock_resource * dlm_get_lock_resource(struct dlm_ctxt *dlm,
781 const char *lockid,
3384f3df 782 int namelen,
6714d8e8
KH
783 int flags)
784{
785 struct dlm_lock_resource *tmpres=NULL, *res=NULL;
786 struct dlm_master_list_entry *mle = NULL;
787 struct dlm_master_list_entry *alloc_mle = NULL;
788 int blocked = 0;
789 int ret, nodenum;
790 struct dlm_node_iter iter;
3384f3df 791 unsigned int hash;
6714d8e8 792 int tries = 0;
c03872f5 793 int bit, wait_on_recovery = 0;
ba2bf218 794 int drop_inflight_if_nonlocal = 0;
6714d8e8
KH
795
796 BUG_ON(!lockid);
797
a3d33291 798 hash = dlm_lockid_hash(lockid, namelen);
6714d8e8
KH
799
800 mlog(0, "get lockres %s (len %d)\n", lockid, namelen);
801
802lookup:
803 spin_lock(&dlm->spinlock);
ba2bf218 804 tmpres = __dlm_lookup_lockres_full(dlm, lockid, namelen, hash);
6714d8e8 805 if (tmpres) {
ba2bf218
KH
806 int dropping_ref = 0;
807
808 spin_lock(&tmpres->spinlock);
809 if (tmpres->owner == dlm->node_num) {
810 BUG_ON(tmpres->state & DLM_LOCK_RES_DROPPING_REF);
811 dlm_lockres_grab_inflight_ref(dlm, tmpres);
812 } else if (tmpres->state & DLM_LOCK_RES_DROPPING_REF)
813 dropping_ref = 1;
814 spin_unlock(&tmpres->spinlock);
6714d8e8 815 spin_unlock(&dlm->spinlock);
ba2bf218
KH
816
817 /* wait until done messaging the master, drop our ref to allow
818 * the lockres to be purged, start over. */
819 if (dropping_ref) {
820 spin_lock(&tmpres->spinlock);
821 __dlm_wait_on_lockres_flags(tmpres, DLM_LOCK_RES_DROPPING_REF);
822 spin_unlock(&tmpres->spinlock);
823 dlm_lockres_put(tmpres);
824 tmpres = NULL;
825 goto lookup;
826 }
827
6714d8e8
KH
828 mlog(0, "found in hash!\n");
829 if (res)
830 dlm_lockres_put(res);
831 res = tmpres;
832 goto leave;
833 }
834
835 if (!res) {
836 spin_unlock(&dlm->spinlock);
837 mlog(0, "allocating a new resource\n");
838 /* nothing found and we need to allocate one. */
839 alloc_mle = (struct dlm_master_list_entry *)
ad8100e0 840 kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
6714d8e8
KH
841 if (!alloc_mle)
842 goto leave;
843 res = dlm_new_lockres(dlm, lockid, namelen);
844 if (!res)
845 goto leave;
846 goto lookup;
847 }
848
849 mlog(0, "no lockres found, allocated our own: %p\n", res);
850
851 if (flags & LKM_LOCAL) {
852 /* caller knows it's safe to assume it's not mastered elsewhere
853 * DONE! return right away */
854 spin_lock(&res->spinlock);
855 dlm_change_lockres_owner(dlm, res, dlm->node_num);
856 __dlm_insert_lockres(dlm, res);
ba2bf218 857 dlm_lockres_grab_inflight_ref(dlm, res);
6714d8e8
KH
858 spin_unlock(&res->spinlock);
859 spin_unlock(&dlm->spinlock);
860 /* lockres still marked IN_PROGRESS */
861 goto wake_waiters;
862 }
863
864 /* check master list to see if another node has started mastering it */
865 spin_lock(&dlm->master_lock);
866
867 /* if we found a block, wait for lock to be mastered by another node */
868 blocked = dlm_find_mle(dlm, &mle, (char *)lockid, namelen);
869 if (blocked) {
ba2bf218 870 int mig;
6714d8e8
KH
871 if (mle->type == DLM_MLE_MASTER) {
872 mlog(ML_ERROR, "master entry for nonexistent lock!\n");
873 BUG();
ba2bf218
KH
874 }
875 mig = (mle->type == DLM_MLE_MIGRATION);
876 /* if there is a migration in progress, let the migration
877 * finish before continuing. we can wait for the absence
878 * of the MIGRATION mle: either the migrate finished or
879 * one of the nodes died and the mle was cleaned up.
880 * if there is a BLOCK here, but it already has a master
881 * set, we are too late. the master does not have a ref
882 * for us in the refmap. detach the mle and drop it.
883 * either way, go back to the top and start over. */
884 if (mig || mle->master != O2NM_MAX_NODES) {
885 BUG_ON(mig && mle->master == dlm->node_num);
886 /* we arrived too late. the master does not
887 * have a ref for us. retry. */
888 mlog(0, "%s:%.*s: late on %s\n",
889 dlm->name, namelen, lockid,
890 mig ? "MIGRATION" : "BLOCK");
6714d8e8 891 spin_unlock(&dlm->master_lock);
6714d8e8
KH
892 spin_unlock(&dlm->spinlock);
893
894 /* master is known, detach */
ba2bf218
KH
895 if (!mig)
896 dlm_mle_detach_hb_events(dlm, mle);
6714d8e8
KH
897 dlm_put_mle(mle);
898 mle = NULL;
ba2bf218
KH
899 /* this is lame, but we cant wait on either
900 * the mle or lockres waitqueue here */
901 if (mig)
902 msleep(100);
903 goto lookup;
6714d8e8
KH
904 }
905 } else {
906 /* go ahead and try to master lock on this node */
907 mle = alloc_mle;
908 /* make sure this does not get freed below */
909 alloc_mle = NULL;
910 dlm_init_mle(mle, DLM_MLE_MASTER, dlm, res, NULL, 0);
911 set_bit(dlm->node_num, mle->maybe_map);
912 list_add(&mle->list, &dlm->master_list);
c03872f5
KH
913
914 /* still holding the dlm spinlock, check the recovery map
915 * to see if there are any nodes that still need to be
916 * considered. these will not appear in the mle nodemap
917 * but they might own this lockres. wait on them. */
918 bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0);
919 if (bit < O2NM_MAX_NODES) {
920 mlog(ML_NOTICE, "%s:%.*s: at least one node (%d) to"
921 "recover before lock mastery can begin\n",
922 dlm->name, namelen, (char *)lockid, bit);
923 wait_on_recovery = 1;
924 }
6714d8e8
KH
925 }
926
927 /* at this point there is either a DLM_MLE_BLOCK or a
928 * DLM_MLE_MASTER on the master list, so it's safe to add the
929 * lockres to the hashtable. anyone who finds the lock will
930 * still have to wait on the IN_PROGRESS. */
931
932 /* finally add the lockres to its hash bucket */
933 __dlm_insert_lockres(dlm, res);
ba2bf218
KH
934 /* since this lockres is new it doesnt not require the spinlock */
935 dlm_lockres_grab_inflight_ref_new(dlm, res);
936
937 /* if this node does not become the master make sure to drop
938 * this inflight reference below */
939 drop_inflight_if_nonlocal = 1;
940
6714d8e8
KH
941 /* get an extra ref on the mle in case this is a BLOCK
942 * if so, the creator of the BLOCK may try to put the last
943 * ref at this time in the assert master handler, so we
944 * need an extra one to keep from a bad ptr deref. */
a2bf0477 945 dlm_get_mle_inuse(mle);
6714d8e8
KH
946 spin_unlock(&dlm->master_lock);
947 spin_unlock(&dlm->spinlock);
948
e7e69eb3 949redo_request:
c03872f5
KH
950 while (wait_on_recovery) {
951 /* any cluster changes that occurred after dropping the
952 * dlm spinlock would be detectable be a change on the mle,
953 * so we only need to clear out the recovery map once. */
954 if (dlm_is_recovery_lock(lockid, namelen)) {
955 mlog(ML_NOTICE, "%s: recovery map is not empty, but "
956 "must master $RECOVERY lock now\n", dlm->name);
957 if (!dlm_pre_master_reco_lockres(dlm, res))
958 wait_on_recovery = 0;
959 else {
960 mlog(0, "%s: waiting 500ms for heartbeat state "
961 "change\n", dlm->name);
962 msleep(500);
963 }
964 continue;
965 }
966
967 dlm_kick_recovery_thread(dlm);
aa087b84 968 msleep(1000);
c03872f5
KH
969 dlm_wait_for_recovery(dlm);
970
971 spin_lock(&dlm->spinlock);
972 bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0);
973 if (bit < O2NM_MAX_NODES) {
974 mlog(ML_NOTICE, "%s:%.*s: at least one node (%d) to"
975 "recover before lock mastery can begin\n",
976 dlm->name, namelen, (char *)lockid, bit);
977 wait_on_recovery = 1;
978 } else
979 wait_on_recovery = 0;
980 spin_unlock(&dlm->spinlock);
b7084ab5
KH
981
982 if (wait_on_recovery)
983 dlm_wait_for_node_recovery(dlm, bit, 10000);
c03872f5
KH
984 }
985
6714d8e8
KH
986 /* must wait for lock to be mastered elsewhere */
987 if (blocked)
988 goto wait;
989
6714d8e8
KH
990 ret = -EINVAL;
991 dlm_node_iter_init(mle->vote_map, &iter);
992 while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
ba2bf218 993 ret = dlm_do_master_request(res, mle, nodenum);
6714d8e8
KH
994 if (ret < 0)
995 mlog_errno(ret);
996 if (mle->master != O2NM_MAX_NODES) {
997 /* found a master ! */
9c6510a5
KH
998 if (mle->master <= nodenum)
999 break;
1000 /* if our master request has not reached the master
1001 * yet, keep going until it does. this is how the
1002 * master will know that asserts are needed back to
1003 * the lower nodes. */
1004 mlog(0, "%s:%.*s: requests only up to %u but master "
1005 "is %u, keep going\n", dlm->name, namelen,
1006 lockid, nodenum, mle->master);
6714d8e8
KH
1007 }
1008 }
1009
1010wait:
1011 /* keep going until the response map includes all nodes */
1012 ret = dlm_wait_for_lock_mastery(dlm, res, mle, &blocked);
1013 if (ret < 0) {
e7e69eb3 1014 wait_on_recovery = 1;
6714d8e8
KH
1015 mlog(0, "%s:%.*s: node map changed, redo the "
1016 "master request now, blocked=%d\n",
1017 dlm->name, res->lockname.len,
1018 res->lockname.name, blocked);
1019 if (++tries > 20) {
1020 mlog(ML_ERROR, "%s:%.*s: spinning on "
1021 "dlm_wait_for_lock_mastery, blocked=%d\n",
1022 dlm->name, res->lockname.len,
1023 res->lockname.name, blocked);
1024 dlm_print_one_lock_resource(res);
8a9343fa 1025 dlm_print_one_mle(mle);
6714d8e8
KH
1026 tries = 0;
1027 }
1028 goto redo_request;
1029 }
1030
1031 mlog(0, "lockres mastered by %u\n", res->owner);
1032 /* make sure we never continue without this */
1033 BUG_ON(res->owner == O2NM_MAX_NODES);
1034
1035 /* master is known, detach if not already detached */
1036 dlm_mle_detach_hb_events(dlm, mle);
1037 dlm_put_mle(mle);
1038 /* put the extra ref */
a2bf0477 1039 dlm_put_mle_inuse(mle);
6714d8e8
KH
1040
1041wake_waiters:
1042 spin_lock(&res->spinlock);
ba2bf218
KH
1043 if (res->owner != dlm->node_num && drop_inflight_if_nonlocal)
1044 dlm_lockres_drop_inflight_ref(dlm, res);
6714d8e8
KH
1045 res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
1046 spin_unlock(&res->spinlock);
1047 wake_up(&res->wq);
1048
1049leave:
1050 /* need to free the unused mle */
1051 if (alloc_mle)
1052 kmem_cache_free(dlm_mle_cache, alloc_mle);
1053
1054 return res;
1055}
1056
1057
1058#define DLM_MASTERY_TIMEOUT_MS 5000
1059
1060static int dlm_wait_for_lock_mastery(struct dlm_ctxt *dlm,
1061 struct dlm_lock_resource *res,
1062 struct dlm_master_list_entry *mle,
1063 int *blocked)
1064{
1065 u8 m;
1066 int ret, bit;
1067 int map_changed, voting_done;
1068 int assert, sleep;
1069
1070recheck:
1071 ret = 0;
1072 assert = 0;
1073
1074 /* check if another node has already become the owner */
1075 spin_lock(&res->spinlock);
1076 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
9c6510a5
KH
1077 mlog(0, "%s:%.*s: owner is suddenly %u\n", dlm->name,
1078 res->lockname.len, res->lockname.name, res->owner);
6714d8e8 1079 spin_unlock(&res->spinlock);
9c6510a5
KH
1080 /* this will cause the master to re-assert across
1081 * the whole cluster, freeing up mles */
588e0090 1082 if (res->owner != dlm->node_num) {
ba2bf218 1083 ret = dlm_do_master_request(res, mle, res->owner);
588e0090
KH
1084 if (ret < 0) {
1085 /* give recovery a chance to run */
1086 mlog(ML_ERROR, "link to %u went down?: %d\n", res->owner, ret);
1087 msleep(500);
1088 goto recheck;
1089 }
9c6510a5
KH
1090 }
1091 ret = 0;
6714d8e8
KH
1092 goto leave;
1093 }
1094 spin_unlock(&res->spinlock);
1095
1096 spin_lock(&mle->spinlock);
1097 m = mle->master;
1098 map_changed = (memcmp(mle->vote_map, mle->node_map,
1099 sizeof(mle->vote_map)) != 0);
1100 voting_done = (memcmp(mle->vote_map, mle->response_map,
1101 sizeof(mle->vote_map)) == 0);
1102
1103 /* restart if we hit any errors */
1104 if (map_changed) {
1105 int b;
1106 mlog(0, "%s: %.*s: node map changed, restarting\n",
1107 dlm->name, res->lockname.len, res->lockname.name);
1108 ret = dlm_restart_lock_mastery(dlm, res, mle, *blocked);
1109 b = (mle->type == DLM_MLE_BLOCK);
1110 if ((*blocked && !b) || (!*blocked && b)) {
1111 mlog(0, "%s:%.*s: status change: old=%d new=%d\n",
1112 dlm->name, res->lockname.len, res->lockname.name,
1113 *blocked, b);
1114 *blocked = b;
1115 }
1116 spin_unlock(&mle->spinlock);
1117 if (ret < 0) {
1118 mlog_errno(ret);
1119 goto leave;
1120 }
1121 mlog(0, "%s:%.*s: restart lock mastery succeeded, "
1122 "rechecking now\n", dlm->name, res->lockname.len,
1123 res->lockname.name);
1124 goto recheck;
aa852354
KH
1125 } else {
1126 if (!voting_done) {
1127 mlog(0, "map not changed and voting not done "
1128 "for %s:%.*s\n", dlm->name, res->lockname.len,
1129 res->lockname.name);
1130 }
6714d8e8
KH
1131 }
1132
1133 if (m != O2NM_MAX_NODES) {
1134 /* another node has done an assert!
1135 * all done! */
1136 sleep = 0;
1137 } else {
1138 sleep = 1;
1139 /* have all nodes responded? */
1140 if (voting_done && !*blocked) {
1141 bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0);
1142 if (dlm->node_num <= bit) {
1143 /* my node number is lowest.
1144 * now tell other nodes that I am
1145 * mastering this. */
1146 mle->master = dlm->node_num;
ba2bf218
KH
1147 /* ref was grabbed in get_lock_resource
1148 * will be dropped in dlmlock_master */
6714d8e8
KH
1149 assert = 1;
1150 sleep = 0;
1151 }
1152 /* if voting is done, but we have not received
1153 * an assert master yet, we must sleep */
1154 }
1155 }
1156
1157 spin_unlock(&mle->spinlock);
1158
1159 /* sleep if we haven't finished voting yet */
1160 if (sleep) {
1161 unsigned long timeo = msecs_to_jiffies(DLM_MASTERY_TIMEOUT_MS);
1162
1163 /*
1164 if (atomic_read(&mle->mle_refs.refcount) < 2)
1165 mlog(ML_ERROR, "mle (%p) refs=%d, name=%.*s\n", mle,
1166 atomic_read(&mle->mle_refs.refcount),
1167 res->lockname.len, res->lockname.name);
1168 */
1169 atomic_set(&mle->woken, 0);
1170 (void)wait_event_timeout(mle->wq,
1171 (atomic_read(&mle->woken) == 1),
1172 timeo);
1173 if (res->owner == O2NM_MAX_NODES) {
ba2bf218
KH
1174 mlog(0, "%s:%.*s: waiting again\n", dlm->name,
1175 res->lockname.len, res->lockname.name);
6714d8e8
KH
1176 goto recheck;
1177 }
1178 mlog(0, "done waiting, master is %u\n", res->owner);
1179 ret = 0;
1180 goto leave;
1181 }
1182
1183 ret = 0; /* done */
1184 if (assert) {
1185 m = dlm->node_num;
1186 mlog(0, "about to master %.*s here, this=%u\n",
1187 res->lockname.len, res->lockname.name, m);
ba2bf218 1188 ret = dlm_do_assert_master(dlm, res, mle->vote_map, 0);
6714d8e8
KH
1189 if (ret) {
1190 /* This is a failure in the network path,
1191 * not in the response to the assert_master
1192 * (any nonzero response is a BUG on this node).
1193 * Most likely a socket just got disconnected
1194 * due to node death. */
1195 mlog_errno(ret);
1196 }
1197 /* no longer need to restart lock mastery.
1198 * all living nodes have been contacted. */
1199 ret = 0;
1200 }
1201
1202 /* set the lockres owner */
1203 spin_lock(&res->spinlock);
ba2bf218
KH
1204 /* mastery reference obtained either during
1205 * assert_master_handler or in get_lock_resource */
6714d8e8
KH
1206 dlm_change_lockres_owner(dlm, res, m);
1207 spin_unlock(&res->spinlock);
1208
1209leave:
1210 return ret;
1211}
1212
1213struct dlm_bitmap_diff_iter
1214{
1215 int curnode;
1216 unsigned long *orig_bm;
1217 unsigned long *cur_bm;
1218 unsigned long diff_bm[BITS_TO_LONGS(O2NM_MAX_NODES)];
1219};
1220
1221enum dlm_node_state_change
1222{
1223 NODE_DOWN = -1,
1224 NODE_NO_CHANGE = 0,
1225 NODE_UP
1226};
1227
1228static void dlm_bitmap_diff_iter_init(struct dlm_bitmap_diff_iter *iter,
1229 unsigned long *orig_bm,
1230 unsigned long *cur_bm)
1231{
1232 unsigned long p1, p2;
1233 int i;
1234
1235 iter->curnode = -1;
1236 iter->orig_bm = orig_bm;
1237 iter->cur_bm = cur_bm;
1238
1239 for (i = 0; i < BITS_TO_LONGS(O2NM_MAX_NODES); i++) {
1240 p1 = *(iter->orig_bm + i);
1241 p2 = *(iter->cur_bm + i);
1242 iter->diff_bm[i] = (p1 & ~p2) | (p2 & ~p1);
1243 }
1244}
1245
1246static int dlm_bitmap_diff_iter_next(struct dlm_bitmap_diff_iter *iter,
1247 enum dlm_node_state_change *state)
1248{
1249 int bit;
1250
1251 if (iter->curnode >= O2NM_MAX_NODES)
1252 return -ENOENT;
1253
1254 bit = find_next_bit(iter->diff_bm, O2NM_MAX_NODES,
1255 iter->curnode+1);
1256 if (bit >= O2NM_MAX_NODES) {
1257 iter->curnode = O2NM_MAX_NODES;
1258 return -ENOENT;
1259 }
1260
1261 /* if it was there in the original then this node died */
1262 if (test_bit(bit, iter->orig_bm))
1263 *state = NODE_DOWN;
1264 else
1265 *state = NODE_UP;
1266
1267 iter->curnode = bit;
1268 return bit;
1269}
1270
1271
1272static int dlm_restart_lock_mastery(struct dlm_ctxt *dlm,
1273 struct dlm_lock_resource *res,
1274 struct dlm_master_list_entry *mle,
1275 int blocked)
1276{
1277 struct dlm_bitmap_diff_iter bdi;
1278 enum dlm_node_state_change sc;
1279 int node;
1280 int ret = 0;
1281
1282 mlog(0, "something happened such that the "
1283 "master process may need to be restarted!\n");
1284
1285 assert_spin_locked(&mle->spinlock);
1286
1287 dlm_bitmap_diff_iter_init(&bdi, mle->vote_map, mle->node_map);
1288 node = dlm_bitmap_diff_iter_next(&bdi, &sc);
1289 while (node >= 0) {
1290 if (sc == NODE_UP) {
e2faea4c
KH
1291 /* a node came up. clear any old vote from
1292 * the response map and set it in the vote map
1293 * then restart the mastery. */
1294 mlog(ML_NOTICE, "node %d up while restarting\n", node);
6714d8e8
KH
1295
1296 /* redo the master request, but only for the new node */
1297 mlog(0, "sending request to new node\n");
1298 clear_bit(node, mle->response_map);
1299 set_bit(node, mle->vote_map);
1300 } else {
1301 mlog(ML_ERROR, "node down! %d\n", node);
6714d8e8
KH
1302 if (blocked) {
1303 int lowest = find_next_bit(mle->maybe_map,
1304 O2NM_MAX_NODES, 0);
1305
1306 /* act like it was never there */
1307 clear_bit(node, mle->maybe_map);
1308
e7e69eb3
KH
1309 if (node == lowest) {
1310 mlog(0, "expected master %u died"
1311 " while this node was blocked "
1312 "waiting on it!\n", node);
1313 lowest = find_next_bit(mle->maybe_map,
1314 O2NM_MAX_NODES,
1315 lowest+1);
1316 if (lowest < O2NM_MAX_NODES) {
1317 mlog(0, "%s:%.*s:still "
1318 "blocked. waiting on %u "
1319 "now\n", dlm->name,
1320 res->lockname.len,
1321 res->lockname.name,
1322 lowest);
1323 } else {
1324 /* mle is an MLE_BLOCK, but
1325 * there is now nothing left to
1326 * block on. we need to return
1327 * all the way back out and try
1328 * again with an MLE_MASTER.
1329 * dlm_do_local_recovery_cleanup
1330 * has already run, so the mle
1331 * refcount is ok */
1332 mlog(0, "%s:%.*s: no "
1333 "longer blocking. try to "
1334 "master this here\n",
1335 dlm->name,
1336 res->lockname.len,
1337 res->lockname.name);
1338 mle->type = DLM_MLE_MASTER;
1339 mle->u.res = res;
1340 }
6714d8e8 1341 }
6714d8e8
KH
1342 }
1343
e7e69eb3
KH
1344 /* now blank out everything, as if we had never
1345 * contacted anyone */
1346 memset(mle->maybe_map, 0, sizeof(mle->maybe_map));
1347 memset(mle->response_map, 0, sizeof(mle->response_map));
1348 /* reset the vote_map to the current node_map */
1349 memcpy(mle->vote_map, mle->node_map,
1350 sizeof(mle->node_map));
1351 /* put myself into the maybe map */
1352 if (mle->type != DLM_MLE_BLOCK)
1353 set_bit(dlm->node_num, mle->maybe_map);
6714d8e8
KH
1354 }
1355 ret = -EAGAIN;
6714d8e8
KH
1356 node = dlm_bitmap_diff_iter_next(&bdi, &sc);
1357 }
1358 return ret;
1359}
1360
1361
1362/*
1363 * DLM_MASTER_REQUEST_MSG
1364 *
1365 * returns: 0 on success,
1366 * -errno on a network error
1367 *
1368 * on error, the caller should assume the target node is "dead"
1369 *
1370 */
1371
ba2bf218
KH
1372static int dlm_do_master_request(struct dlm_lock_resource *res,
1373 struct dlm_master_list_entry *mle, int to)
6714d8e8
KH
1374{
1375 struct dlm_ctxt *dlm = mle->dlm;
1376 struct dlm_master_request request;
1377 int ret, response=0, resend;
1378
1379 memset(&request, 0, sizeof(request));
1380 request.node_idx = dlm->node_num;
1381
1382 BUG_ON(mle->type == DLM_MLE_MIGRATION);
1383
1384 if (mle->type != DLM_MLE_MASTER) {
1385 request.namelen = mle->u.name.len;
1386 memcpy(request.name, mle->u.name.name, request.namelen);
1387 } else {
1388 request.namelen = mle->u.res->lockname.len;
1389 memcpy(request.name, mle->u.res->lockname.name,
1390 request.namelen);
1391 }
1392
1393again:
1394 ret = o2net_send_message(DLM_MASTER_REQUEST_MSG, dlm->key, &request,
1395 sizeof(request), to, &response);
1396 if (ret < 0) {
1397 if (ret == -ESRCH) {
1398 /* should never happen */
1399 mlog(ML_ERROR, "TCP stack not ready!\n");
1400 BUG();
1401 } else if (ret == -EINVAL) {
1402 mlog(ML_ERROR, "bad args passed to o2net!\n");
1403 BUG();
1404 } else if (ret == -ENOMEM) {
1405 mlog(ML_ERROR, "out of memory while trying to send "
1406 "network message! retrying\n");
1407 /* this is totally crude */
1408 msleep(50);
1409 goto again;
1410 } else if (!dlm_is_host_down(ret)) {
1411 /* not a network error. bad. */
1412 mlog_errno(ret);
1413 mlog(ML_ERROR, "unhandled error!");
1414 BUG();
1415 }
1416 /* all other errors should be network errors,
1417 * and likely indicate node death */
1418 mlog(ML_ERROR, "link to %d went down!\n", to);
1419 goto out;
1420 }
1421
1422 ret = 0;
1423 resend = 0;
1424 spin_lock(&mle->spinlock);
1425 switch (response) {
1426 case DLM_MASTER_RESP_YES:
1427 set_bit(to, mle->response_map);
1428 mlog(0, "node %u is the master, response=YES\n", to);
ba2bf218
KH
1429 mlog(0, "%s:%.*s: master node %u now knows I have a "
1430 "reference\n", dlm->name, res->lockname.len,
1431 res->lockname.name, to);
6714d8e8
KH
1432 mle->master = to;
1433 break;
1434 case DLM_MASTER_RESP_NO:
1435 mlog(0, "node %u not master, response=NO\n", to);
1436 set_bit(to, mle->response_map);
1437 break;
1438 case DLM_MASTER_RESP_MAYBE:
1439 mlog(0, "node %u not master, response=MAYBE\n", to);
1440 set_bit(to, mle->response_map);
1441 set_bit(to, mle->maybe_map);
1442 break;
1443 case DLM_MASTER_RESP_ERROR:
1444 mlog(0, "node %u hit an error, resending\n", to);
1445 resend = 1;
1446 response = 0;
1447 break;
1448 default:
1449 mlog(ML_ERROR, "bad response! %u\n", response);
1450 BUG();
1451 }
1452 spin_unlock(&mle->spinlock);
1453 if (resend) {
1454 /* this is also totally crude */
1455 msleep(50);
1456 goto again;
1457 }
1458
1459out:
1460 return ret;
1461}
1462
1463/*
1464 * locks that can be taken here:
1465 * dlm->spinlock
1466 * res->spinlock
1467 * mle->spinlock
1468 * dlm->master_list
1469 *
1470 * if possible, TRIM THIS DOWN!!!
1471 */
d74c9803
KH
1472int dlm_master_request_handler(struct o2net_msg *msg, u32 len, void *data,
1473 void **ret_data)
6714d8e8
KH
1474{
1475 u8 response = DLM_MASTER_RESP_MAYBE;
1476 struct dlm_ctxt *dlm = data;
9c6510a5 1477 struct dlm_lock_resource *res = NULL;
6714d8e8
KH
1478 struct dlm_master_request *request = (struct dlm_master_request *) msg->buf;
1479 struct dlm_master_list_entry *mle = NULL, *tmpmle = NULL;
1480 char *name;
a3d33291 1481 unsigned int namelen, hash;
6714d8e8
KH
1482 int found, ret;
1483 int set_maybe;
9c6510a5 1484 int dispatch_assert = 0;
6714d8e8
KH
1485
1486 if (!dlm_grab(dlm))
1487 return DLM_MASTER_RESP_NO;
1488
1489 if (!dlm_domain_fully_joined(dlm)) {
1490 response = DLM_MASTER_RESP_NO;
1491 goto send_response;
1492 }
1493
1494 name = request->name;
1495 namelen = request->namelen;
a3d33291 1496 hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH
1497
1498 if (namelen > DLM_LOCKID_NAME_MAX) {
1499 response = DLM_IVBUFLEN;
1500 goto send_response;
1501 }
1502
1503way_up_top:
1504 spin_lock(&dlm->spinlock);
a3d33291 1505 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
6714d8e8
KH
1506 if (res) {
1507 spin_unlock(&dlm->spinlock);
1508
1509 /* take care of the easy cases up front */
1510 spin_lock(&res->spinlock);
1cd04dbe
KH
1511 if (res->state & (DLM_LOCK_RES_RECOVERING|
1512 DLM_LOCK_RES_MIGRATING)) {
6714d8e8
KH
1513 spin_unlock(&res->spinlock);
1514 mlog(0, "returning DLM_MASTER_RESP_ERROR since res is "
1cd04dbe 1515 "being recovered/migrated\n");
6714d8e8
KH
1516 response = DLM_MASTER_RESP_ERROR;
1517 if (mle)
1518 kmem_cache_free(dlm_mle_cache, mle);
1519 goto send_response;
1520 }
1521
1522 if (res->owner == dlm->node_num) {
ba2bf218
KH
1523 mlog(0, "%s:%.*s: setting bit %u in refmap\n",
1524 dlm->name, namelen, name, request->node_idx);
1525 dlm_lockres_set_refmap_bit(request->node_idx, res);
6714d8e8 1526 spin_unlock(&res->spinlock);
6714d8e8
KH
1527 response = DLM_MASTER_RESP_YES;
1528 if (mle)
1529 kmem_cache_free(dlm_mle_cache, mle);
1530
1531 /* this node is the owner.
1532 * there is some extra work that needs to
1533 * happen now. the requesting node has
1534 * caused all nodes up to this one to
1535 * create mles. this node now needs to
1536 * go back and clean those up. */
9c6510a5 1537 dispatch_assert = 1;
6714d8e8
KH
1538 goto send_response;
1539 } else if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
1540 spin_unlock(&res->spinlock);
1541 // mlog(0, "node %u is the master\n", res->owner);
1542 response = DLM_MASTER_RESP_NO;
1543 if (mle)
1544 kmem_cache_free(dlm_mle_cache, mle);
1545 goto send_response;
1546 }
1547
1548 /* ok, there is no owner. either this node is
1549 * being blocked, or it is actively trying to
1550 * master this lock. */
1551 if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) {
1552 mlog(ML_ERROR, "lock with no owner should be "
1553 "in-progress!\n");
1554 BUG();
1555 }
1556
1557 // mlog(0, "lockres is in progress...\n");
1558 spin_lock(&dlm->master_lock);
1559 found = dlm_find_mle(dlm, &tmpmle, name, namelen);
1560 if (!found) {
1561 mlog(ML_ERROR, "no mle found for this lock!\n");
1562 BUG();
1563 }
1564 set_maybe = 1;
1565 spin_lock(&tmpmle->spinlock);
1566 if (tmpmle->type == DLM_MLE_BLOCK) {
1567 // mlog(0, "this node is waiting for "
1568 // "lockres to be mastered\n");
1569 response = DLM_MASTER_RESP_NO;
1570 } else if (tmpmle->type == DLM_MLE_MIGRATION) {
1571 mlog(0, "node %u is master, but trying to migrate to "
1572 "node %u.\n", tmpmle->master, tmpmle->new_master);
1573 if (tmpmle->master == dlm->node_num) {
6714d8e8
KH
1574 mlog(ML_ERROR, "no owner on lockres, but this "
1575 "node is trying to migrate it to %u?!\n",
1576 tmpmle->new_master);
1577 BUG();
1578 } else {
1579 /* the real master can respond on its own */
1580 response = DLM_MASTER_RESP_NO;
1581 }
1582 } else if (tmpmle->master != DLM_LOCK_RES_OWNER_UNKNOWN) {
1583 set_maybe = 0;
9c6510a5 1584 if (tmpmle->master == dlm->node_num) {
6714d8e8 1585 response = DLM_MASTER_RESP_YES;
9c6510a5
KH
1586 /* this node will be the owner.
1587 * go back and clean the mles on any
1588 * other nodes */
1589 dispatch_assert = 1;
ba2bf218
KH
1590 dlm_lockres_set_refmap_bit(request->node_idx, res);
1591 mlog(0, "%s:%.*s: setting bit %u in refmap\n",
1592 dlm->name, namelen, name,
1593 request->node_idx);
9c6510a5 1594 } else
6714d8e8
KH
1595 response = DLM_MASTER_RESP_NO;
1596 } else {
1597 // mlog(0, "this node is attempting to "
1598 // "master lockres\n");
1599 response = DLM_MASTER_RESP_MAYBE;
1600 }
1601 if (set_maybe)
1602 set_bit(request->node_idx, tmpmle->maybe_map);
1603 spin_unlock(&tmpmle->spinlock);
1604
1605 spin_unlock(&dlm->master_lock);
1606 spin_unlock(&res->spinlock);
1607
1608 /* keep the mle attached to heartbeat events */
1609 dlm_put_mle(tmpmle);
1610 if (mle)
1611 kmem_cache_free(dlm_mle_cache, mle);
1612 goto send_response;
1613 }
1614
1615 /*
1616 * lockres doesn't exist on this node
1617 * if there is an MLE_BLOCK, return NO
1618 * if there is an MLE_MASTER, return MAYBE
1619 * otherwise, add an MLE_BLOCK, return NO
1620 */
1621 spin_lock(&dlm->master_lock);
1622 found = dlm_find_mle(dlm, &tmpmle, name, namelen);
1623 if (!found) {
1624 /* this lockid has never been seen on this node yet */
1625 // mlog(0, "no mle found\n");
1626 if (!mle) {
1627 spin_unlock(&dlm->master_lock);
1628 spin_unlock(&dlm->spinlock);
1629
1630 mle = (struct dlm_master_list_entry *)
ad8100e0 1631 kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
6714d8e8 1632 if (!mle) {
6714d8e8 1633 response = DLM_MASTER_RESP_ERROR;
9c6510a5 1634 mlog_errno(-ENOMEM);
6714d8e8
KH
1635 goto send_response;
1636 }
6714d8e8
KH
1637 goto way_up_top;
1638 }
1639
1640 // mlog(0, "this is second time thru, already allocated, "
1641 // "add the block.\n");
41b8c8a1 1642 dlm_init_mle(mle, DLM_MLE_BLOCK, dlm, NULL, name, namelen);
6714d8e8
KH
1643 set_bit(request->node_idx, mle->maybe_map);
1644 list_add(&mle->list, &dlm->master_list);
1645 response = DLM_MASTER_RESP_NO;
1646 } else {
1647 // mlog(0, "mle was found\n");
1648 set_maybe = 1;
1649 spin_lock(&tmpmle->spinlock);
9c6510a5
KH
1650 if (tmpmle->master == dlm->node_num) {
1651 mlog(ML_ERROR, "no lockres, but an mle with this node as master!\n");
1652 BUG();
1653 }
6714d8e8
KH
1654 if (tmpmle->type == DLM_MLE_BLOCK)
1655 response = DLM_MASTER_RESP_NO;
1656 else if (tmpmle->type == DLM_MLE_MIGRATION) {
1657 mlog(0, "migration mle was found (%u->%u)\n",
1658 tmpmle->master, tmpmle->new_master);
6714d8e8
KH
1659 /* real master can respond on its own */
1660 response = DLM_MASTER_RESP_NO;
9c6510a5
KH
1661 } else
1662 response = DLM_MASTER_RESP_MAYBE;
6714d8e8
KH
1663 if (set_maybe)
1664 set_bit(request->node_idx, tmpmle->maybe_map);
1665 spin_unlock(&tmpmle->spinlock);
1666 }
1667 spin_unlock(&dlm->master_lock);
1668 spin_unlock(&dlm->spinlock);
1669
1670 if (found) {
1671 /* keep the mle attached to heartbeat events */
1672 dlm_put_mle(tmpmle);
1673 }
1674send_response:
9c6510a5
KH
1675
1676 if (dispatch_assert) {
1677 if (response != DLM_MASTER_RESP_YES)
1678 mlog(ML_ERROR, "invalid response %d\n", response);
1679 if (!res) {
1680 mlog(ML_ERROR, "bad lockres while trying to assert!\n");
1681 BUG();
1682 }
1683 mlog(0, "%u is the owner of %.*s, cleaning everyone else\n",
1684 dlm->node_num, res->lockname.len, res->lockname.name);
1685 ret = dlm_dispatch_assert_master(dlm, res, 0, request->node_idx,
1686 DLM_ASSERT_MASTER_MLE_CLEANUP);
1687 if (ret < 0) {
1688 mlog(ML_ERROR, "failed to dispatch assert master work\n");
1689 response = DLM_MASTER_RESP_ERROR;
1690 }
1691 }
1692
6714d8e8
KH
1693 dlm_put(dlm);
1694 return response;
1695}
1696
1697/*
1698 * DLM_ASSERT_MASTER_MSG
1699 */
1700
1701
1702/*
1703 * NOTE: this can be used for debugging
1704 * can periodically run all locks owned by this node
1705 * and re-assert across the cluster...
1706 */
ba2bf218
KH
1707int dlm_do_assert_master(struct dlm_ctxt *dlm,
1708 struct dlm_lock_resource *res,
1709 void *nodemap, u32 flags)
6714d8e8
KH
1710{
1711 struct dlm_assert_master assert;
1712 int to, tmpret;
1713 struct dlm_node_iter iter;
1714 int ret = 0;
9c6510a5 1715 int reassert;
ba2bf218
KH
1716 const char *lockname = res->lockname.name;
1717 unsigned int namelen = res->lockname.len;
6714d8e8
KH
1718
1719 BUG_ON(namelen > O2NM_MAX_NAME_LEN);
9c6510a5
KH
1720again:
1721 reassert = 0;
6714d8e8
KH
1722
1723 /* note that if this nodemap is empty, it returns 0 */
1724 dlm_node_iter_init(nodemap, &iter);
1725 while ((to = dlm_node_iter_next(&iter)) >= 0) {
1726 int r = 0;
a9ee4c8a
KH
1727 struct dlm_master_list_entry *mle = NULL;
1728
6714d8e8
KH
1729 mlog(0, "sending assert master to %d (%.*s)\n", to,
1730 namelen, lockname);
1731 memset(&assert, 0, sizeof(assert));
1732 assert.node_idx = dlm->node_num;
1733 assert.namelen = namelen;
1734 memcpy(assert.name, lockname, namelen);
1735 assert.flags = cpu_to_be32(flags);
1736
1737 tmpret = o2net_send_message(DLM_ASSERT_MASTER_MSG, dlm->key,
1738 &assert, sizeof(assert), to, &r);
1739 if (tmpret < 0) {
3b3b84a8 1740 mlog(0, "assert_master returned %d!\n", tmpret);
6714d8e8 1741 if (!dlm_is_host_down(tmpret)) {
3b3b84a8 1742 mlog(ML_ERROR, "unhandled error=%d!\n", tmpret);
6714d8e8
KH
1743 BUG();
1744 }
1745 /* a node died. finish out the rest of the nodes. */
3b3b84a8 1746 mlog(0, "link to %d went down!\n", to);
6714d8e8
KH
1747 /* any nonzero status return will do */
1748 ret = tmpret;
ba2bf218 1749 r = 0;
6714d8e8
KH
1750 } else if (r < 0) {
1751 /* ok, something horribly messed. kill thyself. */
1752 mlog(ML_ERROR,"during assert master of %.*s to %u, "
1753 "got %d.\n", namelen, lockname, to, r);
a9ee4c8a
KH
1754 spin_lock(&dlm->spinlock);
1755 spin_lock(&dlm->master_lock);
1756 if (dlm_find_mle(dlm, &mle, (char *)lockname,
1757 namelen)) {
1758 dlm_print_one_mle(mle);
1759 __dlm_put_mle(mle);
1760 }
1761 spin_unlock(&dlm->master_lock);
1762 spin_unlock(&dlm->spinlock);
6714d8e8 1763 BUG();
ba2bf218
KH
1764 }
1765
1766 if (r & DLM_ASSERT_RESPONSE_REASSERT &&
1767 !(r & DLM_ASSERT_RESPONSE_MASTERY_REF)) {
1768 mlog(ML_ERROR, "%.*s: very strange, "
1769 "master MLE but no lockres on %u\n",
1770 namelen, lockname, to);
1771 }
1772
1773 if (r & DLM_ASSERT_RESPONSE_REASSERT) {
9c6510a5
KH
1774 mlog(0, "%.*s: node %u create mles on other "
1775 "nodes and requests a re-assert\n",
1776 namelen, lockname, to);
1777 reassert = 1;
6714d8e8 1778 }
ba2bf218
KH
1779 if (r & DLM_ASSERT_RESPONSE_MASTERY_REF) {
1780 mlog(0, "%.*s: node %u has a reference to this "
1781 "lockres, set the bit in the refmap\n",
1782 namelen, lockname, to);
1783 spin_lock(&res->spinlock);
1784 dlm_lockres_set_refmap_bit(to, res);
1785 spin_unlock(&res->spinlock);
1786 }
6714d8e8
KH
1787 }
1788
9c6510a5
KH
1789 if (reassert)
1790 goto again;
1791
6714d8e8
KH
1792 return ret;
1793}
1794
1795/*
1796 * locks that can be taken here:
1797 * dlm->spinlock
1798 * res->spinlock
1799 * mle->spinlock
1800 * dlm->master_list
1801 *
1802 * if possible, TRIM THIS DOWN!!!
1803 */
d74c9803
KH
1804int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data,
1805 void **ret_data)
6714d8e8
KH
1806{
1807 struct dlm_ctxt *dlm = data;
1808 struct dlm_master_list_entry *mle = NULL;
1809 struct dlm_assert_master *assert = (struct dlm_assert_master *)msg->buf;
1810 struct dlm_lock_resource *res = NULL;
1811 char *name;
a3d33291 1812 unsigned int namelen, hash;
6714d8e8 1813 u32 flags;
ba2bf218 1814 int master_request = 0, have_lockres_ref = 0;
9c6510a5 1815 int ret = 0;
6714d8e8
KH
1816
1817 if (!dlm_grab(dlm))
1818 return 0;
1819
1820 name = assert->name;
1821 namelen = assert->namelen;
a3d33291 1822 hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH
1823 flags = be32_to_cpu(assert->flags);
1824
1825 if (namelen > DLM_LOCKID_NAME_MAX) {
1826 mlog(ML_ERROR, "Invalid name length!");
1827 goto done;
1828 }
1829
1830 spin_lock(&dlm->spinlock);
1831
1832 if (flags)
1833 mlog(0, "assert_master with flags: %u\n", flags);
1834
1835 /* find the MLE */
1836 spin_lock(&dlm->master_lock);
1837 if (!dlm_find_mle(dlm, &mle, name, namelen)) {
1838 /* not an error, could be master just re-asserting */
1839 mlog(0, "just got an assert_master from %u, but no "
1840 "MLE for it! (%.*s)\n", assert->node_idx,
1841 namelen, name);
1842 } else {
1843 int bit = find_next_bit (mle->maybe_map, O2NM_MAX_NODES, 0);
1844 if (bit >= O2NM_MAX_NODES) {
1845 /* not necessarily an error, though less likely.
1846 * could be master just re-asserting. */
aa852354 1847 mlog(0, "no bits set in the maybe_map, but %u "
6714d8e8
KH
1848 "is asserting! (%.*s)\n", assert->node_idx,
1849 namelen, name);
1850 } else if (bit != assert->node_idx) {
1851 if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) {
1852 mlog(0, "master %u was found, %u should "
1853 "back off\n", assert->node_idx, bit);
1854 } else {
1855 /* with the fix for bug 569, a higher node
1856 * number winning the mastery will respond
1857 * YES to mastery requests, but this node
1858 * had no way of knowing. let it pass. */
aa852354 1859 mlog(0, "%u is the lowest node, "
6714d8e8
KH
1860 "%u is asserting. (%.*s) %u must "
1861 "have begun after %u won.\n", bit,
1862 assert->node_idx, namelen, name, bit,
1863 assert->node_idx);
1864 }
1865 }
2d1a868c
KH
1866 if (mle->type == DLM_MLE_MIGRATION) {
1867 if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) {
1868 mlog(0, "%s:%.*s: got cleanup assert"
1869 " from %u for migration\n",
1870 dlm->name, namelen, name,
1871 assert->node_idx);
1872 } else if (!(flags & DLM_ASSERT_MASTER_FINISH_MIGRATION)) {
1873 mlog(0, "%s:%.*s: got unrelated assert"
1874 " from %u for migration, ignoring\n",
1875 dlm->name, namelen, name,
1876 assert->node_idx);
1877 __dlm_put_mle(mle);
1878 spin_unlock(&dlm->master_lock);
1879 spin_unlock(&dlm->spinlock);
1880 goto done;
1881 }
1882 }
6714d8e8
KH
1883 }
1884 spin_unlock(&dlm->master_lock);
1885
1886 /* ok everything checks out with the MLE
1887 * now check to see if there is a lockres */
a3d33291 1888 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
6714d8e8
KH
1889 if (res) {
1890 spin_lock(&res->spinlock);
1891 if (res->state & DLM_LOCK_RES_RECOVERING) {
1892 mlog(ML_ERROR, "%u asserting but %.*s is "
1893 "RECOVERING!\n", assert->node_idx, namelen, name);
1894 goto kill;
1895 }
1896 if (!mle) {
dc2ed195
KH
1897 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN &&
1898 res->owner != assert->node_idx) {
6714d8e8
KH
1899 mlog(ML_ERROR, "assert_master from "
1900 "%u, but current owner is "
1901 "%u! (%.*s)\n",
1902 assert->node_idx, res->owner,
1903 namelen, name);
1904 goto kill;
1905 }
1906 } else if (mle->type != DLM_MLE_MIGRATION) {
1907 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
1908 /* owner is just re-asserting */
1909 if (res->owner == assert->node_idx) {
1910 mlog(0, "owner %u re-asserting on "
1911 "lock %.*s\n", assert->node_idx,
1912 namelen, name);
1913 goto ok;
1914 }
1915 mlog(ML_ERROR, "got assert_master from "
1916 "node %u, but %u is the owner! "
1917 "(%.*s)\n", assert->node_idx,
1918 res->owner, namelen, name);
1919 goto kill;
1920 }
1921 if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) {
1922 mlog(ML_ERROR, "got assert from %u, but lock "
1923 "with no owner should be "
1924 "in-progress! (%.*s)\n",
1925 assert->node_idx,
1926 namelen, name);
1927 goto kill;
1928 }
1929 } else /* mle->type == DLM_MLE_MIGRATION */ {
1930 /* should only be getting an assert from new master */
1931 if (assert->node_idx != mle->new_master) {
1932 mlog(ML_ERROR, "got assert from %u, but "
1933 "new master is %u, and old master "
1934 "was %u (%.*s)\n",
1935 assert->node_idx, mle->new_master,
1936 mle->master, namelen, name);
1937 goto kill;
1938 }
1939
1940 }
1941ok:
1942 spin_unlock(&res->spinlock);
1943 }
1944 spin_unlock(&dlm->spinlock);
1945
1946 // mlog(0, "woo! got an assert_master from node %u!\n",
1947 // assert->node_idx);
1948 if (mle) {
9c6510a5
KH
1949 int extra_ref = 0;
1950 int nn = -1;
a2bf0477 1951 int rr, err = 0;
6714d8e8
KH
1952
1953 spin_lock(&mle->spinlock);
9c6510a5
KH
1954 if (mle->type == DLM_MLE_BLOCK || mle->type == DLM_MLE_MIGRATION)
1955 extra_ref = 1;
1956 else {
1957 /* MASTER mle: if any bits set in the response map
1958 * then the calling node needs to re-assert to clear
1959 * up nodes that this node contacted */
1960 while ((nn = find_next_bit (mle->response_map, O2NM_MAX_NODES,
1961 nn+1)) < O2NM_MAX_NODES) {
1962 if (nn != dlm->node_num && nn != assert->node_idx)
1963 master_request = 1;
1964 }
1965 }
6714d8e8
KH
1966 mle->master = assert->node_idx;
1967 atomic_set(&mle->woken, 1);
1968 wake_up(&mle->wq);
1969 spin_unlock(&mle->spinlock);
1970
a2bf0477 1971 if (res) {
a6fa3640 1972 int wake = 0;
6714d8e8 1973 spin_lock(&res->spinlock);
a2bf0477
KH
1974 if (mle->type == DLM_MLE_MIGRATION) {
1975 mlog(0, "finishing off migration of lockres %.*s, "
1976 "from %u to %u\n",
1977 res->lockname.len, res->lockname.name,
1978 dlm->node_num, mle->new_master);
1979 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 1980 wake = 1;
a2bf0477
KH
1981 dlm_change_lockres_owner(dlm, res, mle->new_master);
1982 BUG_ON(res->state & DLM_LOCK_RES_DIRTY);
1983 } else {
1984 dlm_change_lockres_owner(dlm, res, mle->master);
1985 }
6714d8e8 1986 spin_unlock(&res->spinlock);
ba2bf218 1987 have_lockres_ref = 1;
a6fa3640
KH
1988 if (wake)
1989 wake_up(&res->wq);
6714d8e8 1990 }
a2bf0477
KH
1991
1992 /* master is known, detach if not already detached.
1993 * ensures that only one assert_master call will happen
1994 * on this mle. */
1995 spin_lock(&dlm->spinlock);
1996 spin_lock(&dlm->master_lock);
1997
1998 rr = atomic_read(&mle->mle_refs.refcount);
1999 if (mle->inuse > 0) {
2000 if (extra_ref && rr < 3)
2001 err = 1;
2002 else if (!extra_ref && rr < 2)
2003 err = 1;
2004 } else {
2005 if (extra_ref && rr < 2)
2006 err = 1;
2007 else if (!extra_ref && rr < 1)
2008 err = 1;
2009 }
2010 if (err) {
2011 mlog(ML_ERROR, "%s:%.*s: got assert master from %u "
2012 "that will mess up this node, refs=%d, extra=%d, "
2013 "inuse=%d\n", dlm->name, namelen, name,
2014 assert->node_idx, rr, extra_ref, mle->inuse);
2015 dlm_print_one_mle(mle);
2016 }
2017 list_del_init(&mle->list);
2018 __dlm_mle_detach_hb_events(dlm, mle);
2019 __dlm_put_mle(mle);
6714d8e8
KH
2020 if (extra_ref) {
2021 /* the assert master message now balances the extra
2022 * ref given by the master / migration request message.
2023 * if this is the last put, it will be removed
2024 * from the list. */
a2bf0477
KH
2025 __dlm_put_mle(mle);
2026 }
2027 spin_unlock(&dlm->master_lock);
2028 spin_unlock(&dlm->spinlock);
2029 } else if (res) {
2030 if (res->owner != assert->node_idx) {
2031 mlog(0, "assert_master from %u, but current "
2032 "owner is %u (%.*s), no mle\n", assert->node_idx,
2033 res->owner, namelen, name);
6714d8e8
KH
2034 }
2035 }
2036
2037done:
9c6510a5 2038 ret = 0;
3b8118cf
KH
2039 if (res) {
2040 spin_lock(&res->spinlock);
2041 res->state |= DLM_LOCK_RES_SETREF_INPROG;
2042 spin_unlock(&res->spinlock);
2043 *ret_data = (void *)res;
2044 }
6714d8e8 2045 dlm_put(dlm);
9c6510a5
KH
2046 if (master_request) {
2047 mlog(0, "need to tell master to reassert\n");
ba2bf218
KH
2048 /* positive. negative would shoot down the node. */
2049 ret |= DLM_ASSERT_RESPONSE_REASSERT;
2050 if (!have_lockres_ref) {
2051 mlog(ML_ERROR, "strange, got assert from %u, MASTER "
2052 "mle present here for %s:%.*s, but no lockres!\n",
2053 assert->node_idx, dlm->name, namelen, name);
2054 }
2055 }
2056 if (have_lockres_ref) {
2057 /* let the master know we have a reference to the lockres */
2058 ret |= DLM_ASSERT_RESPONSE_MASTERY_REF;
2059 mlog(0, "%s:%.*s: got assert from %u, need a ref\n",
2060 dlm->name, namelen, name, assert->node_idx);
9c6510a5
KH
2061 }
2062 return ret;
6714d8e8
KH
2063
2064kill:
2065 /* kill the caller! */
a9ee4c8a
KH
2066 mlog(ML_ERROR, "Bad message received from another node. Dumping state "
2067 "and killing the other node now! This node is OK and can continue.\n");
2068 __dlm_print_one_lock_resource(res);
6714d8e8
KH
2069 spin_unlock(&res->spinlock);
2070 spin_unlock(&dlm->spinlock);
3b8118cf 2071 *ret_data = (void *)res;
6714d8e8
KH
2072 dlm_put(dlm);
2073 return -EINVAL;
2074}
2075
3b8118cf
KH
2076void dlm_assert_master_post_handler(int status, void *data, void *ret_data)
2077{
2078 struct dlm_lock_resource *res = (struct dlm_lock_resource *)ret_data;
2079
2080 if (ret_data) {
2081 spin_lock(&res->spinlock);
2082 res->state &= ~DLM_LOCK_RES_SETREF_INPROG;
2083 spin_unlock(&res->spinlock);
2084 wake_up(&res->wq);
2085 dlm_lockres_put(res);
2086 }
2087 return;
2088}
2089
6714d8e8
KH
2090int dlm_dispatch_assert_master(struct dlm_ctxt *dlm,
2091 struct dlm_lock_resource *res,
2092 int ignore_higher, u8 request_from, u32 flags)
2093{
2094 struct dlm_work_item *item;
cd861280 2095 item = kzalloc(sizeof(*item), GFP_NOFS);
6714d8e8
KH
2096 if (!item)
2097 return -ENOMEM;
2098
2099
2100 /* queue up work for dlm_assert_master_worker */
2101 dlm_grab(dlm); /* get an extra ref for the work item */
2102 dlm_init_work_item(dlm, item, dlm_assert_master_worker, NULL);
2103 item->u.am.lockres = res; /* already have a ref */
2104 /* can optionally ignore node numbers higher than this node */
2105 item->u.am.ignore_higher = ignore_higher;
2106 item->u.am.request_from = request_from;
2107 item->u.am.flags = flags;
2108
9c6510a5
KH
2109 if (ignore_higher)
2110 mlog(0, "IGNORE HIGHER: %.*s\n", res->lockname.len,
2111 res->lockname.name);
2112
6714d8e8
KH
2113 spin_lock(&dlm->work_lock);
2114 list_add_tail(&item->list, &dlm->work_list);
2115 spin_unlock(&dlm->work_lock);
2116
3156d267 2117 queue_work(dlm->dlm_worker, &dlm->dispatched_work);
6714d8e8
KH
2118 return 0;
2119}
2120
2121static void dlm_assert_master_worker(struct dlm_work_item *item, void *data)
2122{
2123 struct dlm_ctxt *dlm = data;
2124 int ret = 0;
2125 struct dlm_lock_resource *res;
2126 unsigned long nodemap[BITS_TO_LONGS(O2NM_MAX_NODES)];
2127 int ignore_higher;
2128 int bit;
2129 u8 request_from;
2130 u32 flags;
2131
2132 dlm = item->dlm;
2133 res = item->u.am.lockres;
2134 ignore_higher = item->u.am.ignore_higher;
2135 request_from = item->u.am.request_from;
2136 flags = item->u.am.flags;
2137
2138 spin_lock(&dlm->spinlock);
2139 memcpy(nodemap, dlm->domain_map, sizeof(nodemap));
2140 spin_unlock(&dlm->spinlock);
2141
2142 clear_bit(dlm->node_num, nodemap);
2143 if (ignore_higher) {
2144 /* if is this just to clear up mles for nodes below
2145 * this node, do not send the message to the original
2146 * caller or any node number higher than this */
2147 clear_bit(request_from, nodemap);
2148 bit = dlm->node_num;
2149 while (1) {
2150 bit = find_next_bit(nodemap, O2NM_MAX_NODES,
2151 bit+1);
2152 if (bit >= O2NM_MAX_NODES)
2153 break;
2154 clear_bit(bit, nodemap);
2155 }
2156 }
2157
36407488
KH
2158 /*
2159 * If we're migrating this lock to someone else, we are no
2160 * longer allowed to assert out own mastery. OTOH, we need to
2161 * prevent migration from starting while we're still asserting
2162 * our dominance. The reserved ast delays migration.
2163 */
2164 spin_lock(&res->spinlock);
2165 if (res->state & DLM_LOCK_RES_MIGRATING) {
2166 mlog(0, "Someone asked us to assert mastery, but we're "
2167 "in the middle of migration. Skipping assert, "
2168 "the new master will handle that.\n");
2169 spin_unlock(&res->spinlock);
2170 goto put;
2171 } else
2172 __dlm_lockres_reserve_ast(res);
2173 spin_unlock(&res->spinlock);
2174
6714d8e8
KH
2175 /* this call now finishes out the nodemap
2176 * even if one or more nodes die */
2177 mlog(0, "worker about to master %.*s here, this=%u\n",
2178 res->lockname.len, res->lockname.name, dlm->node_num);
ba2bf218 2179 ret = dlm_do_assert_master(dlm, res, nodemap, flags);
6714d8e8
KH
2180 if (ret < 0) {
2181 /* no need to restart, we are done */
3b3b84a8
KH
2182 if (!dlm_is_host_down(ret))
2183 mlog_errno(ret);
6714d8e8
KH
2184 }
2185
36407488
KH
2186 /* Ok, we've asserted ourselves. Let's let migration start. */
2187 dlm_lockres_release_ast(dlm, res);
2188
2189put:
6714d8e8
KH
2190 dlm_lockres_put(res);
2191
2192 mlog(0, "finished with dlm_assert_master_worker\n");
2193}
2194
c03872f5
KH
2195/* SPECIAL CASE for the $RECOVERY lock used by the recovery thread.
2196 * We cannot wait for node recovery to complete to begin mastering this
2197 * lockres because this lockres is used to kick off recovery! ;-)
2198 * So, do a pre-check on all living nodes to see if any of those nodes
2199 * think that $RECOVERY is currently mastered by a dead node. If so,
2200 * we wait a short time to allow that node to get notified by its own
2201 * heartbeat stack, then check again. All $RECOVERY lock resources
2202 * mastered by dead nodes are purged when the hearbeat callback is
2203 * fired, so we can know for sure that it is safe to continue once
2204 * the node returns a live node or no node. */
2205static int dlm_pre_master_reco_lockres(struct dlm_ctxt *dlm,
2206 struct dlm_lock_resource *res)
2207{
2208 struct dlm_node_iter iter;
2209 int nodenum;
2210 int ret = 0;
2211 u8 master = DLM_LOCK_RES_OWNER_UNKNOWN;
2212
2213 spin_lock(&dlm->spinlock);
2214 dlm_node_iter_init(dlm->domain_map, &iter);
2215 spin_unlock(&dlm->spinlock);
2216
2217 while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2218 /* do not send to self */
2219 if (nodenum == dlm->node_num)
2220 continue;
2221 ret = dlm_do_master_requery(dlm, res, nodenum, &master);
2222 if (ret < 0) {
2223 mlog_errno(ret);
2224 if (!dlm_is_host_down(ret))
2225 BUG();
2226 /* host is down, so answer for that node would be
2227 * DLM_LOCK_RES_OWNER_UNKNOWN. continue. */
f42a100b 2228 ret = 0;
c03872f5
KH
2229 }
2230
2231 if (master != DLM_LOCK_RES_OWNER_UNKNOWN) {
2232 /* check to see if this master is in the recovery map */
2233 spin_lock(&dlm->spinlock);
2234 if (test_bit(master, dlm->recovery_map)) {
2235 mlog(ML_NOTICE, "%s: node %u has not seen "
2236 "node %u go down yet, and thinks the "
2237 "dead node is mastering the recovery "
2238 "lock. must wait.\n", dlm->name,
2239 nodenum, master);
2240 ret = -EAGAIN;
2241 }
2242 spin_unlock(&dlm->spinlock);
2243 mlog(0, "%s: reco lock master is %u\n", dlm->name,
2244 master);
2245 break;
2246 }
2247 }
2248 return ret;
2249}
2250
ba2bf218
KH
2251/*
2252 * DLM_DEREF_LOCKRES_MSG
2253 */
2254
2255int dlm_drop_lockres_ref(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
2256{
2257 struct dlm_deref_lockres deref;
2258 int ret = 0, r;
2259 const char *lockname;
2260 unsigned int namelen;
2261
2262 lockname = res->lockname.name;
2263 namelen = res->lockname.len;
2264 BUG_ON(namelen > O2NM_MAX_NAME_LEN);
2265
2266 mlog(0, "%s:%.*s: sending deref to %d\n",
2267 dlm->name, namelen, lockname, res->owner);
2268 memset(&deref, 0, sizeof(deref));
2269 deref.node_idx = dlm->node_num;
2270 deref.namelen = namelen;
2271 memcpy(deref.name, lockname, namelen);
2272
2273 ret = o2net_send_message(DLM_DEREF_LOCKRES_MSG, dlm->key,
2274 &deref, sizeof(deref), res->owner, &r);
2275 if (ret < 0)
2276 mlog_errno(ret);
2277 else if (r < 0) {
2278 /* BAD. other node says I did not have a ref. */
2279 mlog(ML_ERROR,"while dropping ref on %s:%.*s "
2280 "(master=%u) got %d.\n", dlm->name, namelen,
2281 lockname, res->owner, r);
2282 dlm_print_one_lock_resource(res);
2283 BUG();
2284 }
2285 return ret;
2286}
2287
d74c9803
KH
2288int dlm_deref_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
2289 void **ret_data)
ba2bf218
KH
2290{
2291 struct dlm_ctxt *dlm = data;
2292 struct dlm_deref_lockres *deref = (struct dlm_deref_lockres *)msg->buf;
2293 struct dlm_lock_resource *res = NULL;
2294 char *name;
2295 unsigned int namelen;
2296 int ret = -EINVAL;
2297 u8 node;
2298 unsigned int hash;
2299
2300 if (!dlm_grab(dlm))
2301 return 0;
2302
2303 name = deref->name;
2304 namelen = deref->namelen;
2305 node = deref->node_idx;
2306
2307 if (namelen > DLM_LOCKID_NAME_MAX) {
2308 mlog(ML_ERROR, "Invalid name length!");
2309 goto done;
2310 }
2311 if (deref->node_idx >= O2NM_MAX_NODES) {
2312 mlog(ML_ERROR, "Invalid node number: %u\n", node);
2313 goto done;
2314 }
2315
2316 hash = dlm_lockid_hash(name, namelen);
2317
2318 spin_lock(&dlm->spinlock);
2319 res = __dlm_lookup_lockres_full(dlm, name, namelen, hash);
2320 if (!res) {
2321 spin_unlock(&dlm->spinlock);
2322 mlog(ML_ERROR, "%s:%.*s: bad lockres name\n",
2323 dlm->name, namelen, name);
2324 goto done;
2325 }
2326 spin_unlock(&dlm->spinlock);
2327
2328 spin_lock(&res->spinlock);
2329 BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF);
2330 if (test_bit(node, res->refmap)) {
2331 ret = 0;
2332 dlm_lockres_clear_refmap_bit(node, res);
2333 } else {
2334 mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref "
2335 "but it is already dropped!\n", dlm->name, namelen,
2336 name, node);
2337 __dlm_print_one_lock_resource(res);
2338 }
2339 spin_unlock(&res->spinlock);
2340
2341 if (!ret)
2342 dlm_lockres_calc_usage(dlm, res);
2343done:
2344 if (res)
2345 dlm_lockres_put(res);
2346 dlm_put(dlm);
2347 return ret;
2348}
2349
6714d8e8
KH
2350
2351/*
2352 * DLM_MIGRATE_LOCKRES
2353 */
2354
2355
faf0ec9f
AB
2356static int dlm_migrate_lockres(struct dlm_ctxt *dlm,
2357 struct dlm_lock_resource *res,
2358 u8 target)
6714d8e8
KH
2359{
2360 struct dlm_master_list_entry *mle = NULL;
2361 struct dlm_master_list_entry *oldmle = NULL;
2362 struct dlm_migratable_lockres *mres = NULL;
2363 int ret = -EINVAL;
2364 const char *name;
2365 unsigned int namelen;
2366 int mle_added = 0;
2367 struct list_head *queue, *iter;
2368 int i;
2369 struct dlm_lock *lock;
a6fa3640 2370 int empty = 1, wake = 0;
6714d8e8
KH
2371
2372 if (!dlm_grab(dlm))
2373 return -EINVAL;
2374
2375 name = res->lockname.name;
2376 namelen = res->lockname.len;
2377
2378 mlog(0, "migrating %.*s to %u\n", namelen, name, target);
2379
2380 /*
2381 * ensure this lockres is a proper candidate for migration
2382 */
2383 spin_lock(&res->spinlock);
2384 if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
2385 mlog(0, "cannot migrate lockres with unknown owner!\n");
2386 spin_unlock(&res->spinlock);
2387 goto leave;
2388 }
2389 if (res->owner != dlm->node_num) {
2390 mlog(0, "cannot migrate lockres this node doesn't own!\n");
2391 spin_unlock(&res->spinlock);
2392 goto leave;
2393 }
2394 mlog(0, "checking queues...\n");
2395 queue = &res->granted;
2396 for (i=0; i<3; i++) {
2397 list_for_each(iter, queue) {
2398 lock = list_entry (iter, struct dlm_lock, list);
2399 empty = 0;
2400 if (lock->ml.node == dlm->node_num) {
2401 mlog(0, "found a lock owned by this node "
2402 "still on the %s queue! will not "
2403 "migrate this lockres\n",
2404 i==0 ? "granted" :
2405 (i==1 ? "converting" : "blocked"));
2406 spin_unlock(&res->spinlock);
2407 ret = -ENOTEMPTY;
2408 goto leave;
2409 }
2410 }
2411 queue++;
2412 }
2413 mlog(0, "all locks on this lockres are nonlocal. continuing\n");
2414 spin_unlock(&res->spinlock);
2415
2416 /* no work to do */
2417 if (empty) {
2418 mlog(0, "no locks were found on this lockres! done!\n");
2419 ret = 0;
2420 goto leave;
2421 }
2422
2423 /*
2424 * preallocate up front
2425 * if this fails, abort
2426 */
2427
2428 ret = -ENOMEM;
ad8100e0 2429 mres = (struct dlm_migratable_lockres *) __get_free_page(GFP_NOFS);
6714d8e8
KH
2430 if (!mres) {
2431 mlog_errno(ret);
2432 goto leave;
2433 }
2434
2435 mle = (struct dlm_master_list_entry *) kmem_cache_alloc(dlm_mle_cache,
ad8100e0 2436 GFP_NOFS);
6714d8e8
KH
2437 if (!mle) {
2438 mlog_errno(ret);
2439 goto leave;
2440 }
2441 ret = 0;
2442
2443 /*
2444 * find a node to migrate the lockres to
2445 */
2446
2447 mlog(0, "picking a migration node\n");
2448 spin_lock(&dlm->spinlock);
2449 /* pick a new node */
2450 if (!test_bit(target, dlm->domain_map) ||
2451 target >= O2NM_MAX_NODES) {
2452 target = dlm_pick_migration_target(dlm, res);
2453 }
2454 mlog(0, "node %u chosen for migration\n", target);
2455
2456 if (target >= O2NM_MAX_NODES ||
2457 !test_bit(target, dlm->domain_map)) {
2458 /* target chosen is not alive */
2459 ret = -EINVAL;
2460 }
2461
2462 if (ret) {
2463 spin_unlock(&dlm->spinlock);
2464 goto fail;
2465 }
2466
2467 mlog(0, "continuing with target = %u\n", target);
2468
2469 /*
2470 * clear any existing master requests and
2471 * add the migration mle to the list
2472 */
2473 spin_lock(&dlm->master_lock);
2474 ret = dlm_add_migration_mle(dlm, res, mle, &oldmle, name,
2475 namelen, target, dlm->node_num);
2476 spin_unlock(&dlm->master_lock);
2477 spin_unlock(&dlm->spinlock);
2478
2479 if (ret == -EEXIST) {
2480 mlog(0, "another process is already migrating it\n");
2481 goto fail;
2482 }
2483 mle_added = 1;
2484
2485 /*
2486 * set the MIGRATING flag and flush asts
2487 * if we fail after this we need to re-dirty the lockres
2488 */
2489 if (dlm_mark_lockres_migrating(dlm, res, target) < 0) {
2490 mlog(ML_ERROR, "tried to migrate %.*s to %u, but "
2491 "the target went down.\n", res->lockname.len,
2492 res->lockname.name, target);
2493 spin_lock(&res->spinlock);
2494 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 2495 wake = 1;
6714d8e8
KH
2496 spin_unlock(&res->spinlock);
2497 ret = -EINVAL;
2498 }
2499
2500fail:
2501 if (oldmle) {
2502 /* master is known, detach if not already detached */
2503 dlm_mle_detach_hb_events(dlm, oldmle);
2504 dlm_put_mle(oldmle);
2505 }
2506
2507 if (ret < 0) {
2508 if (mle_added) {
2509 dlm_mle_detach_hb_events(dlm, mle);
2510 dlm_put_mle(mle);
2511 } else if (mle) {
2512 kmem_cache_free(dlm_mle_cache, mle);
2513 }
2514 goto leave;
2515 }
2516
2517 /*
2518 * at this point, we have a migration target, an mle
2519 * in the master list, and the MIGRATING flag set on
2520 * the lockres
2521 */
2522
1cd04dbe
KH
2523 /* now that remote nodes are spinning on the MIGRATING flag,
2524 * ensure that all assert_master work is flushed. */
2525 flush_workqueue(dlm->dlm_worker);
6714d8e8
KH
2526
2527 /* get an extra reference on the mle.
2528 * otherwise the assert_master from the new
2529 * master will destroy this.
2530 * also, make sure that all callers of dlm_get_mle
2531 * take both dlm->spinlock and dlm->master_lock */
2532 spin_lock(&dlm->spinlock);
2533 spin_lock(&dlm->master_lock);
a2bf0477 2534 dlm_get_mle_inuse(mle);
6714d8e8
KH
2535 spin_unlock(&dlm->master_lock);
2536 spin_unlock(&dlm->spinlock);
2537
2538 /* notify new node and send all lock state */
2539 /* call send_one_lockres with migration flag.
2540 * this serves as notice to the target node that a
2541 * migration is starting. */
2542 ret = dlm_send_one_lockres(dlm, res, mres, target,
2543 DLM_MRES_MIGRATION);
2544
2545 if (ret < 0) {
2546 mlog(0, "migration to node %u failed with %d\n",
2547 target, ret);
2548 /* migration failed, detach and clean up mle */
2549 dlm_mle_detach_hb_events(dlm, mle);
2550 dlm_put_mle(mle);
a2bf0477
KH
2551 dlm_put_mle_inuse(mle);
2552 spin_lock(&res->spinlock);
2553 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 2554 wake = 1;
a2bf0477 2555 spin_unlock(&res->spinlock);
6714d8e8
KH
2556 goto leave;
2557 }
2558
2559 /* at this point, the target sends a message to all nodes,
2560 * (using dlm_do_migrate_request). this node is skipped since
2561 * we had to put an mle in the list to begin the process. this
2562 * node now waits for target to do an assert master. this node
2563 * will be the last one notified, ensuring that the migration
2564 * is complete everywhere. if the target dies while this is
2565 * going on, some nodes could potentially see the target as the
2566 * master, so it is important that my recovery finds the migration
2567 * mle and sets the master to UNKNONWN. */
2568
2569
2570 /* wait for new node to assert master */
2571 while (1) {
2572 ret = wait_event_interruptible_timeout(mle->wq,
2573 (atomic_read(&mle->woken) == 1),
2574 msecs_to_jiffies(5000));
2575
2576 if (ret >= 0) {
2577 if (atomic_read(&mle->woken) == 1 ||
2578 res->owner == target)
2579 break;
2580
1cd04dbe
KH
2581 mlog(0, "%s:%.*s: timed out during migration\n",
2582 dlm->name, res->lockname.len, res->lockname.name);
e2faea4c
KH
2583 /* avoid hang during shutdown when migrating lockres
2584 * to a node which also goes down */
2585 if (dlm_is_node_dead(dlm, target)) {
aa852354
KH
2586 mlog(0, "%s:%.*s: expected migration "
2587 "target %u is no longer up, restarting\n",
e2faea4c
KH
2588 dlm->name, res->lockname.len,
2589 res->lockname.name, target);
1cd04dbe
KH
2590 ret = -EINVAL;
2591 /* migration failed, detach and clean up mle */
2592 dlm_mle_detach_hb_events(dlm, mle);
2593 dlm_put_mle(mle);
2594 dlm_put_mle_inuse(mle);
2595 spin_lock(&res->spinlock);
2596 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 2597 wake = 1;
1cd04dbe
KH
2598 spin_unlock(&res->spinlock);
2599 goto leave;
e2faea4c 2600 }
1cd04dbe
KH
2601 } else
2602 mlog(0, "%s:%.*s: caught signal during migration\n",
2603 dlm->name, res->lockname.len, res->lockname.name);
6714d8e8
KH
2604 }
2605
2606 /* all done, set the owner, clear the flag */
2607 spin_lock(&res->spinlock);
2608 dlm_set_lockres_owner(dlm, res, target);
2609 res->state &= ~DLM_LOCK_RES_MIGRATING;
2610 dlm_remove_nonlocal_locks(dlm, res);
2611 spin_unlock(&res->spinlock);
2612 wake_up(&res->wq);
2613
2614 /* master is known, detach if not already detached */
2615 dlm_mle_detach_hb_events(dlm, mle);
a2bf0477 2616 dlm_put_mle_inuse(mle);
6714d8e8
KH
2617 ret = 0;
2618
2619 dlm_lockres_calc_usage(dlm, res);
2620
2621leave:
2622 /* re-dirty the lockres if we failed */
2623 if (ret < 0)
2624 dlm_kick_thread(dlm, res);
2625
a6fa3640
KH
2626 /* wake up waiters if the MIGRATING flag got set
2627 * but migration failed */
2628 if (wake)
2629 wake_up(&res->wq);
2630
6714d8e8
KH
2631 /* TODO: cleanup */
2632 if (mres)
2633 free_page((unsigned long)mres);
2634
2635 dlm_put(dlm);
2636
2637 mlog(0, "returning %d\n", ret);
2638 return ret;
2639}
6714d8e8 2640
ba2bf218
KH
2641#define DLM_MIGRATION_RETRY_MS 100
2642
2643/* Should be called only after beginning the domain leave process.
2644 * There should not be any remaining locks on nonlocal lock resources,
2645 * and there should be no local locks left on locally mastered resources.
2646 *
2647 * Called with the dlm spinlock held, may drop it to do migration, but
2648 * will re-acquire before exit.
2649 *
2650 * Returns: 1 if dlm->spinlock was dropped/retaken, 0 if never dropped */
2651int dlm_empty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
2652{
2653 int ret;
2654 int lock_dropped = 0;
2655
2656 if (res->owner != dlm->node_num) {
2657 if (!__dlm_lockres_unused(res)) {
2658 mlog(ML_ERROR, "%s:%.*s: this node is not master, "
2659 "trying to free this but locks remain\n",
2660 dlm->name, res->lockname.len, res->lockname.name);
2661 }
2662 goto leave;
2663 }
2664
2665 /* Wheee! Migrate lockres here! Will sleep so drop spinlock. */
2666 spin_unlock(&dlm->spinlock);
2667 lock_dropped = 1;
2668 while (1) {
2669 ret = dlm_migrate_lockres(dlm, res, O2NM_MAX_NODES);
2670 if (ret >= 0)
2671 break;
2672 if (ret == -ENOTEMPTY) {
2673 mlog(ML_ERROR, "lockres %.*s still has local locks!\n",
2674 res->lockname.len, res->lockname.name);
2675 BUG();
2676 }
2677
2678 mlog(0, "lockres %.*s: migrate failed, "
2679 "retrying\n", res->lockname.len,
2680 res->lockname.name);
2681 msleep(DLM_MIGRATION_RETRY_MS);
2682 }
2683 spin_lock(&dlm->spinlock);
2684leave:
2685 return lock_dropped;
2686}
2687
6714d8e8
KH
2688int dlm_lock_basts_flushed(struct dlm_ctxt *dlm, struct dlm_lock *lock)
2689{
2690 int ret;
2691 spin_lock(&dlm->ast_lock);
2692 spin_lock(&lock->spinlock);
2693 ret = (list_empty(&lock->bast_list) && !lock->bast_pending);
2694 spin_unlock(&lock->spinlock);
2695 spin_unlock(&dlm->ast_lock);
2696 return ret;
2697}
2698
2699static int dlm_migration_can_proceed(struct dlm_ctxt *dlm,
2700 struct dlm_lock_resource *res,
2701 u8 mig_target)
2702{
2703 int can_proceed;
2704 spin_lock(&res->spinlock);
2705 can_proceed = !!(res->state & DLM_LOCK_RES_MIGRATING);
2706 spin_unlock(&res->spinlock);
2707
2708 /* target has died, so make the caller break out of the
2709 * wait_event, but caller must recheck the domain_map */
2710 spin_lock(&dlm->spinlock);
2711 if (!test_bit(mig_target, dlm->domain_map))
2712 can_proceed = 1;
2713 spin_unlock(&dlm->spinlock);
2714 return can_proceed;
2715}
2716
faf0ec9f
AB
2717static int dlm_lockres_is_dirty(struct dlm_ctxt *dlm,
2718 struct dlm_lock_resource *res)
6714d8e8
KH
2719{
2720 int ret;
2721 spin_lock(&res->spinlock);
2722 ret = !!(res->state & DLM_LOCK_RES_DIRTY);
2723 spin_unlock(&res->spinlock);
2724 return ret;
2725}
2726
2727
2728static int dlm_mark_lockres_migrating(struct dlm_ctxt *dlm,
2729 struct dlm_lock_resource *res,
2730 u8 target)
2731{
2732 int ret = 0;
2733
2734 mlog(0, "dlm_mark_lockres_migrating: %.*s, from %u to %u\n",
2735 res->lockname.len, res->lockname.name, dlm->node_num,
2736 target);
2737 /* need to set MIGRATING flag on lockres. this is done by
2738 * ensuring that all asts have been flushed for this lockres. */
2739 spin_lock(&res->spinlock);
2740 BUG_ON(res->migration_pending);
2741 res->migration_pending = 1;
2742 /* strategy is to reserve an extra ast then release
2743 * it below, letting the release do all of the work */
2744 __dlm_lockres_reserve_ast(res);
2745 spin_unlock(&res->spinlock);
2746
ddc09c8d 2747 /* now flush all the pending asts */
6714d8e8 2748 dlm_kick_thread(dlm, res);
ddc09c8d
KH
2749 /* before waiting on DIRTY, block processes which may
2750 * try to dirty the lockres before MIGRATING is set */
2751 spin_lock(&res->spinlock);
2752 BUG_ON(res->state & DLM_LOCK_RES_BLOCK_DIRTY);
2753 res->state |= DLM_LOCK_RES_BLOCK_DIRTY;
2754 spin_unlock(&res->spinlock);
2755 /* now wait on any pending asts and the DIRTY state */
6714d8e8
KH
2756 wait_event(dlm->ast_wq, !dlm_lockres_is_dirty(dlm, res));
2757 dlm_lockres_release_ast(dlm, res);
2758
2759 mlog(0, "about to wait on migration_wq, dirty=%s\n",
2760 res->state & DLM_LOCK_RES_DIRTY ? "yes" : "no");
2761 /* if the extra ref we just put was the final one, this
2762 * will pass thru immediately. otherwise, we need to wait
2763 * for the last ast to finish. */
2764again:
2765 ret = wait_event_interruptible_timeout(dlm->migration_wq,
2766 dlm_migration_can_proceed(dlm, res, target),
2767 msecs_to_jiffies(1000));
2768 if (ret < 0) {
2769 mlog(0, "woken again: migrating? %s, dead? %s\n",
2770 res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no",
2771 test_bit(target, dlm->domain_map) ? "no":"yes");
2772 } else {
2773 mlog(0, "all is well: migrating? %s, dead? %s\n",
2774 res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no",
2775 test_bit(target, dlm->domain_map) ? "no":"yes");
2776 }
2777 if (!dlm_migration_can_proceed(dlm, res, target)) {
2778 mlog(0, "trying again...\n");
2779 goto again;
2780 }
ddc09c8d
KH
2781 /* now that we are sure the MIGRATING state is there, drop
2782 * the unneded state which blocked threads trying to DIRTY */
2783 spin_lock(&res->spinlock);
2784 BUG_ON(!(res->state & DLM_LOCK_RES_BLOCK_DIRTY));
2785 BUG_ON(!(res->state & DLM_LOCK_RES_MIGRATING));
2786 res->state &= ~DLM_LOCK_RES_BLOCK_DIRTY;
2787 spin_unlock(&res->spinlock);
6714d8e8
KH
2788
2789 /* did the target go down or die? */
2790 spin_lock(&dlm->spinlock);
2791 if (!test_bit(target, dlm->domain_map)) {
2792 mlog(ML_ERROR, "aha. migration target %u just went down\n",
2793 target);
2794 ret = -EHOSTDOWN;
2795 }
2796 spin_unlock(&dlm->spinlock);
2797
2798 /*
2799 * at this point:
2800 *
2801 * o the DLM_LOCK_RES_MIGRATING flag is set
2802 * o there are no pending asts on this lockres
2803 * o all processes trying to reserve an ast on this
2804 * lockres must wait for the MIGRATING flag to clear
2805 */
2806 return ret;
2807}
2808
2809/* last step in the migration process.
2810 * original master calls this to free all of the dlm_lock
2811 * structures that used to be for other nodes. */
2812static void dlm_remove_nonlocal_locks(struct dlm_ctxt *dlm,
2813 struct dlm_lock_resource *res)
2814{
2815 struct list_head *iter, *iter2;
2816 struct list_head *queue = &res->granted;
ba2bf218 2817 int i, bit;
6714d8e8
KH
2818 struct dlm_lock *lock;
2819
2820 assert_spin_locked(&res->spinlock);
2821
2822 BUG_ON(res->owner == dlm->node_num);
2823
2824 for (i=0; i<3; i++) {
2825 list_for_each_safe(iter, iter2, queue) {
2826 lock = list_entry (iter, struct dlm_lock, list);
2827 if (lock->ml.node != dlm->node_num) {
2828 mlog(0, "putting lock for node %u\n",
2829 lock->ml.node);
2830 /* be extra careful */
2831 BUG_ON(!list_empty(&lock->ast_list));
2832 BUG_ON(!list_empty(&lock->bast_list));
2833 BUG_ON(lock->ast_pending);
2834 BUG_ON(lock->bast_pending);
ba2bf218 2835 dlm_lockres_clear_refmap_bit(lock->ml.node, res);
6714d8e8
KH
2836 list_del_init(&lock->list);
2837 dlm_lock_put(lock);
2838 }
2839 }
2840 queue++;
2841 }
ba2bf218
KH
2842 bit = 0;
2843 while (1) {
2844 bit = find_next_bit(res->refmap, O2NM_MAX_NODES, bit);
2845 if (bit >= O2NM_MAX_NODES)
2846 break;
2847 /* do not clear the local node reference, if there is a
2848 * process holding this, let it drop the ref itself */
2849 if (bit != dlm->node_num) {
2850 mlog(0, "%s:%.*s: node %u had a ref to this "
2851 "migrating lockres, clearing\n", dlm->name,
2852 res->lockname.len, res->lockname.name, bit);
2853 dlm_lockres_clear_refmap_bit(bit, res);
2854 }
2855 bit++;
2856 }
6714d8e8
KH
2857}
2858
2859/* for now this is not too intelligent. we will
2860 * need stats to make this do the right thing.
2861 * this just finds the first lock on one of the
2862 * queues and uses that node as the target. */
2863static u8 dlm_pick_migration_target(struct dlm_ctxt *dlm,
2864 struct dlm_lock_resource *res)
2865{
2866 int i;
2867 struct list_head *queue = &res->granted;
2868 struct list_head *iter;
2869 struct dlm_lock *lock;
2870 int nodenum;
2871
2872 assert_spin_locked(&dlm->spinlock);
2873
2874 spin_lock(&res->spinlock);
2875 for (i=0; i<3; i++) {
2876 list_for_each(iter, queue) {
2877 /* up to the caller to make sure this node
2878 * is alive */
2879 lock = list_entry (iter, struct dlm_lock, list);
2880 if (lock->ml.node != dlm->node_num) {
2881 spin_unlock(&res->spinlock);
2882 return lock->ml.node;
2883 }
2884 }
2885 queue++;
2886 }
2887 spin_unlock(&res->spinlock);
2888 mlog(0, "have not found a suitable target yet! checking domain map\n");
2889
2890 /* ok now we're getting desperate. pick anyone alive. */
2891 nodenum = -1;
2892 while (1) {
2893 nodenum = find_next_bit(dlm->domain_map,
2894 O2NM_MAX_NODES, nodenum+1);
2895 mlog(0, "found %d in domain map\n", nodenum);
2896 if (nodenum >= O2NM_MAX_NODES)
2897 break;
2898 if (nodenum != dlm->node_num) {
2899 mlog(0, "picking %d\n", nodenum);
2900 return nodenum;
2901 }
2902 }
2903
2904 mlog(0, "giving up. no master to migrate to\n");
2905 return DLM_LOCK_RES_OWNER_UNKNOWN;
2906}
2907
2908
2909
2910/* this is called by the new master once all lockres
2911 * data has been received */
2912static int dlm_do_migrate_request(struct dlm_ctxt *dlm,
2913 struct dlm_lock_resource *res,
2914 u8 master, u8 new_master,
2915 struct dlm_node_iter *iter)
2916{
2917 struct dlm_migrate_request migrate;
2918 int ret, status = 0;
2919 int nodenum;
2920
2921 memset(&migrate, 0, sizeof(migrate));
2922 migrate.namelen = res->lockname.len;
2923 memcpy(migrate.name, res->lockname.name, migrate.namelen);
2924 migrate.new_master = new_master;
2925 migrate.master = master;
2926
2927 ret = 0;
2928
2929 /* send message to all nodes, except the master and myself */
2930 while ((nodenum = dlm_node_iter_next(iter)) >= 0) {
2931 if (nodenum == master ||
2932 nodenum == new_master)
2933 continue;
2934
2935 ret = o2net_send_message(DLM_MIGRATE_REQUEST_MSG, dlm->key,
2936 &migrate, sizeof(migrate), nodenum,
2937 &status);
2938 if (ret < 0)
2939 mlog_errno(ret);
2940 else if (status < 0) {
2941 mlog(0, "migrate request (node %u) returned %d!\n",
2942 nodenum, status);
2943 ret = status;
ba2bf218
KH
2944 } else if (status == DLM_MIGRATE_RESPONSE_MASTERY_REF) {
2945 /* during the migration request we short-circuited
2946 * the mastery of the lockres. make sure we have
2947 * a mastery ref for nodenum */
2948 mlog(0, "%s:%.*s: need ref for node %u\n",
2949 dlm->name, res->lockname.len, res->lockname.name,
2950 nodenum);
2951 spin_lock(&res->spinlock);
2952 dlm_lockres_set_refmap_bit(nodenum, res);
2953 spin_unlock(&res->spinlock);
6714d8e8
KH
2954 }
2955 }
2956
2957 if (ret < 0)
2958 mlog_errno(ret);
2959
2960 mlog(0, "returning ret=%d\n", ret);
2961 return ret;
2962}
2963
2964
2965/* if there is an existing mle for this lockres, we now know who the master is.
2966 * (the one who sent us *this* message) we can clear it up right away.
2967 * since the process that put the mle on the list still has a reference to it,
2968 * we can unhash it now, set the master and wake the process. as a result,
2969 * we will have no mle in the list to start with. now we can add an mle for
2970 * the migration and this should be the only one found for those scanning the
2971 * list. */
d74c9803
KH
2972int dlm_migrate_request_handler(struct o2net_msg *msg, u32 len, void *data,
2973 void **ret_data)
6714d8e8
KH
2974{
2975 struct dlm_ctxt *dlm = data;
2976 struct dlm_lock_resource *res = NULL;
2977 struct dlm_migrate_request *migrate = (struct dlm_migrate_request *) msg->buf;
2978 struct dlm_master_list_entry *mle = NULL, *oldmle = NULL;
2979 const char *name;
a3d33291 2980 unsigned int namelen, hash;
6714d8e8
KH
2981 int ret = 0;
2982
2983 if (!dlm_grab(dlm))
2984 return -EINVAL;
2985
2986 name = migrate->name;
2987 namelen = migrate->namelen;
a3d33291 2988 hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH
2989
2990 /* preallocate.. if this fails, abort */
2991 mle = (struct dlm_master_list_entry *) kmem_cache_alloc(dlm_mle_cache,
ad8100e0 2992 GFP_NOFS);
6714d8e8
KH
2993
2994 if (!mle) {
2995 ret = -ENOMEM;
2996 goto leave;
2997 }
2998
2999 /* check for pre-existing lock */
3000 spin_lock(&dlm->spinlock);
a3d33291 3001 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
6714d8e8
KH
3002 spin_lock(&dlm->master_lock);
3003
3004 if (res) {
3005 spin_lock(&res->spinlock);
3006 if (res->state & DLM_LOCK_RES_RECOVERING) {
3007 /* if all is working ok, this can only mean that we got
3008 * a migrate request from a node that we now see as
3009 * dead. what can we do here? drop it to the floor? */
3010 spin_unlock(&res->spinlock);
3011 mlog(ML_ERROR, "Got a migrate request, but the "
3012 "lockres is marked as recovering!");
3013 kmem_cache_free(dlm_mle_cache, mle);
3014 ret = -EINVAL; /* need a better solution */
3015 goto unlock;
3016 }
3017 res->state |= DLM_LOCK_RES_MIGRATING;
3018 spin_unlock(&res->spinlock);
3019 }
3020
3021 /* ignore status. only nonzero status would BUG. */
3022 ret = dlm_add_migration_mle(dlm, res, mle, &oldmle,
3023 name, namelen,
3024 migrate->new_master,
3025 migrate->master);
3026
3027unlock:
3028 spin_unlock(&dlm->master_lock);
3029 spin_unlock(&dlm->spinlock);
3030
3031 if (oldmle) {
3032 /* master is known, detach if not already detached */
3033 dlm_mle_detach_hb_events(dlm, oldmle);
3034 dlm_put_mle(oldmle);
3035 }
3036
3037 if (res)
3038 dlm_lockres_put(res);
3039leave:
3040 dlm_put(dlm);
3041 return ret;
3042}
3043
3044/* must be holding dlm->spinlock and dlm->master_lock
3045 * when adding a migration mle, we can clear any other mles
3046 * in the master list because we know with certainty that
3047 * the master is "master". so we remove any old mle from
3048 * the list after setting it's master field, and then add
3049 * the new migration mle. this way we can hold with the rule
3050 * of having only one mle for a given lock name at all times. */
3051static int dlm_add_migration_mle(struct dlm_ctxt *dlm,
3052 struct dlm_lock_resource *res,
3053 struct dlm_master_list_entry *mle,
3054 struct dlm_master_list_entry **oldmle,
3055 const char *name, unsigned int namelen,
3056 u8 new_master, u8 master)
3057{
3058 int found;
3059 int ret = 0;
3060
3061 *oldmle = NULL;
3062
3063 mlog_entry_void();
3064
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);
3096 /* remove it from the list so that only one
3097 * mle will be found */
3098 list_del_init(&tmp->list);
ba2bf218
KH
3099 /* this was obviously WRONG. mle is uninited here. should be tmp. */
3100 __dlm_mle_detach_hb_events(dlm, tmp);
3101 ret = DLM_MIGRATE_RESPONSE_MASTERY_REF;
3102 mlog(0, "%s:%.*s: master=%u, newmaster=%u, "
3103 "telling master to get ref for cleared out mle "
3104 "during migration\n", dlm->name, namelen, name,
3105 master, new_master);
6714d8e8
KH
3106 }
3107 spin_unlock(&tmp->spinlock);
3108 }
3109
3110 /* now add a migration mle to the tail of the list */
3111 dlm_init_mle(mle, DLM_MLE_MIGRATION, dlm, res, name, namelen);
3112 mle->new_master = new_master;
ba2bf218
KH
3113 /* the new master will be sending an assert master for this.
3114 * at that point we will get the refmap reference */
6714d8e8
KH
3115 mle->master = master;
3116 /* do this for consistency with other mle types */
3117 set_bit(new_master, mle->maybe_map);
3118 list_add(&mle->list, &dlm->master_list);
3119
3120 return ret;
3121}
3122
3123
3124void dlm_clean_master_list(struct dlm_ctxt *dlm, u8 dead_node)
3125{
3126 struct list_head *iter, *iter2;
3127 struct dlm_master_list_entry *mle;
3128 struct dlm_lock_resource *res;
a3d33291 3129 unsigned int hash;
6714d8e8
KH
3130
3131 mlog_entry("dlm=%s, dead node=%u\n", dlm->name, dead_node);
3132top:
3133 assert_spin_locked(&dlm->spinlock);
3134
3135 /* clean the master list */
3136 spin_lock(&dlm->master_lock);
3137 list_for_each_safe(iter, iter2, &dlm->master_list) {
3138 mle = list_entry(iter, struct dlm_master_list_entry, list);
3139
3140 BUG_ON(mle->type != DLM_MLE_BLOCK &&
3141 mle->type != DLM_MLE_MASTER &&
3142 mle->type != DLM_MLE_MIGRATION);
3143
3144 /* MASTER mles are initiated locally. the waiting
3145 * process will notice the node map change
3146 * shortly. let that happen as normal. */
3147 if (mle->type == DLM_MLE_MASTER)
3148 continue;
3149
3150
3151 /* BLOCK mles are initiated by other nodes.
3152 * need to clean up if the dead node would have
3153 * been the master. */
3154 if (mle->type == DLM_MLE_BLOCK) {
3155 int bit;
3156
3157 spin_lock(&mle->spinlock);
3158 bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0);
3159 if (bit != dead_node) {
3160 mlog(0, "mle found, but dead node %u would "
3161 "not have been master\n", dead_node);
3162 spin_unlock(&mle->spinlock);
3163 } else {
3164 /* must drop the refcount by one since the
3165 * assert_master will never arrive. this
3166 * may result in the mle being unlinked and
3167 * freed, but there may still be a process
3168 * waiting in the dlmlock path which is fine. */
3b3b84a8 3169 mlog(0, "node %u was expected master\n",
6714d8e8
KH
3170 dead_node);
3171 atomic_set(&mle->woken, 1);
3172 spin_unlock(&mle->spinlock);
3173 wake_up(&mle->wq);
f671c09b
KH
3174 /* do not need events any longer, so detach
3175 * from heartbeat */
3176 __dlm_mle_detach_hb_events(dlm, mle);
6714d8e8
KH
3177 __dlm_put_mle(mle);
3178 }
3179 continue;
3180 }
3181
3182 /* everything else is a MIGRATION mle */
3183
3184 /* the rule for MIGRATION mles is that the master
3185 * becomes UNKNOWN if *either* the original or
3186 * the new master dies. all UNKNOWN lockreses
3187 * are sent to whichever node becomes the recovery
3188 * master. the new master is responsible for
3189 * determining if there is still a master for
3190 * this lockres, or if he needs to take over
3191 * mastery. either way, this node should expect
3192 * another message to resolve this. */
3193 if (mle->master != dead_node &&
3194 mle->new_master != dead_node)
3195 continue;
3196
3197 /* if we have reached this point, this mle needs to
3198 * be removed from the list and freed. */
3199
3200 /* remove from the list early. NOTE: unlinking
3201 * list_head while in list_for_each_safe */
da01ad05 3202 __dlm_mle_detach_hb_events(dlm, mle);
6714d8e8
KH
3203 spin_lock(&mle->spinlock);
3204 list_del_init(&mle->list);
3205 atomic_set(&mle->woken, 1);
3206 spin_unlock(&mle->spinlock);
3207 wake_up(&mle->wq);
3208
aa852354
KH
3209 mlog(0, "%s: node %u died during migration from "
3210 "%u to %u!\n", dlm->name, dead_node,
6714d8e8
KH
3211 mle->master, mle->new_master);
3212 /* if there is a lockres associated with this
3213 * mle, find it and set its owner to UNKNOWN */
a3d33291 3214 hash = dlm_lockid_hash(mle->u.name.name, mle->u.name.len);
6714d8e8 3215 res = __dlm_lookup_lockres(dlm, mle->u.name.name,
a3d33291 3216 mle->u.name.len, hash);
6714d8e8
KH
3217 if (res) {
3218 /* unfortunately if we hit this rare case, our
3219 * lock ordering is messed. we need to drop
3220 * the master lock so that we can take the
3221 * lockres lock, meaning that we will have to
3222 * restart from the head of list. */
3223 spin_unlock(&dlm->master_lock);
3224
3225 /* move lockres onto recovery list */
3226 spin_lock(&res->spinlock);
3227 dlm_set_lockres_owner(dlm, res,
3228 DLM_LOCK_RES_OWNER_UNKNOWN);
3229 dlm_move_lockres_to_recovery_list(dlm, res);
3230 spin_unlock(&res->spinlock);
3231 dlm_lockres_put(res);
3232
f671c09b
KH
3233 /* about to get rid of mle, detach from heartbeat */
3234 __dlm_mle_detach_hb_events(dlm, mle);
3235
6714d8e8
KH
3236 /* dump the mle */
3237 spin_lock(&dlm->master_lock);
3238 __dlm_put_mle(mle);
3239 spin_unlock(&dlm->master_lock);
3240
3241 /* restart */
3242 goto top;
3243 }
3244
3245 /* this may be the last reference */
3246 __dlm_put_mle(mle);
3247 }
3248 spin_unlock(&dlm->master_lock);
3249}
3250
3251
3252int dlm_finish_migration(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
3253 u8 old_master)
3254{
3255 struct dlm_node_iter iter;
3256 int ret = 0;
3257
3258 spin_lock(&dlm->spinlock);
3259 dlm_node_iter_init(dlm->domain_map, &iter);
3260 clear_bit(old_master, iter.node_map);
3261 clear_bit(dlm->node_num, iter.node_map);
3262 spin_unlock(&dlm->spinlock);
3263
ba2bf218
KH
3264 /* ownership of the lockres is changing. account for the
3265 * mastery reference here since old_master will briefly have
3266 * a reference after the migration completes */
3267 spin_lock(&res->spinlock);
3268 dlm_lockres_set_refmap_bit(old_master, res);
3269 spin_unlock(&res->spinlock);
3270
6714d8e8
KH
3271 mlog(0, "now time to do a migrate request to other nodes\n");
3272 ret = dlm_do_migrate_request(dlm, res, old_master,
3273 dlm->node_num, &iter);
3274 if (ret < 0) {
3275 mlog_errno(ret);
3276 goto leave;
3277 }
3278
3279 mlog(0, "doing assert master of %.*s to all except the original node\n",
3280 res->lockname.len, res->lockname.name);
3281 /* this call now finishes out the nodemap
3282 * even if one or more nodes die */
ba2bf218 3283 ret = dlm_do_assert_master(dlm, res, iter.node_map,
6714d8e8
KH
3284 DLM_ASSERT_MASTER_FINISH_MIGRATION);
3285 if (ret < 0) {
3286 /* no longer need to retry. all living nodes contacted. */
3287 mlog_errno(ret);
3288 ret = 0;
3289 }
3290
3291 memset(iter.node_map, 0, sizeof(iter.node_map));
3292 set_bit(old_master, iter.node_map);
3293 mlog(0, "doing assert master of %.*s back to %u\n",
3294 res->lockname.len, res->lockname.name, old_master);
ba2bf218 3295 ret = dlm_do_assert_master(dlm, res, iter.node_map,
6714d8e8
KH
3296 DLM_ASSERT_MASTER_FINISH_MIGRATION);
3297 if (ret < 0) {
3298 mlog(0, "assert master to original master failed "
3299 "with %d.\n", ret);
3300 /* the only nonzero status here would be because of
3301 * a dead original node. we're done. */
3302 ret = 0;
3303 }
3304
3305 /* all done, set the owner, clear the flag */
3306 spin_lock(&res->spinlock);
3307 dlm_set_lockres_owner(dlm, res, dlm->node_num);
3308 res->state &= ~DLM_LOCK_RES_MIGRATING;
3309 spin_unlock(&res->spinlock);
3310 /* re-dirty it on the new master */
3311 dlm_kick_thread(dlm, res);
3312 wake_up(&res->wq);
3313leave:
3314 return ret;
3315}
3316
3317/*
3318 * LOCKRES AST REFCOUNT
3319 * this is integral to migration
3320 */
3321
3322/* for future intent to call an ast, reserve one ahead of time.
3323 * this should be called only after waiting on the lockres
3324 * with dlm_wait_on_lockres, and while still holding the
3325 * spinlock after the call. */
3326void __dlm_lockres_reserve_ast(struct dlm_lock_resource *res)
3327{
3328 assert_spin_locked(&res->spinlock);
3329 if (res->state & DLM_LOCK_RES_MIGRATING) {
3330 __dlm_print_one_lock_resource(res);
3331 }
3332 BUG_ON(res->state & DLM_LOCK_RES_MIGRATING);
3333
3334 atomic_inc(&res->asts_reserved);
3335}
3336
3337/*
3338 * used to drop the reserved ast, either because it went unused,
3339 * or because the ast/bast was actually called.
3340 *
3341 * also, if there is a pending migration on this lockres,
3342 * and this was the last pending ast on the lockres,
3343 * atomically set the MIGRATING flag before we drop the lock.
3344 * this is how we ensure that migration can proceed with no
3345 * asts in progress. note that it is ok if the state of the
3346 * queues is such that a lock should be granted in the future
3347 * or that a bast should be fired, because the new master will
3348 * shuffle the lists on this lockres as soon as it is migrated.
3349 */
3350void dlm_lockres_release_ast(struct dlm_ctxt *dlm,
3351 struct dlm_lock_resource *res)
3352{
3353 if (!atomic_dec_and_lock(&res->asts_reserved, &res->spinlock))
3354 return;
3355
3356 if (!res->migration_pending) {
3357 spin_unlock(&res->spinlock);
3358 return;
3359 }
3360
3361 BUG_ON(res->state & DLM_LOCK_RES_MIGRATING);
3362 res->migration_pending = 0;
3363 res->state |= DLM_LOCK_RES_MIGRATING;
3364 spin_unlock(&res->spinlock);
3365 wake_up(&res->wq);
3366 wake_up(&dlm->migration_wq);
3367}
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