blob: f784177b62417bea10e474d568f45e07ddbb5781 [file] [log] [blame]
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001/* -*- 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"
Adrian Bunk82353b52005-12-19 11:16:07 -080050#include "dlmdomain.h"
Kurt Hackel6714d8e2005-12-15 14:31:23 -080051
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;
Kurt Hackela2bf0472006-04-27 18:51:26 -070076 int inuse;
Kurt Hackel6714d8e2005-12-15 14:31:23 -080077 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);
102static int dlm_do_assert_master(struct dlm_ctxt *dlm, const char *lockname,
103 unsigned int namelen, void *nodemap,
104 u32 flags);
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
Kurt Hackel95883712006-04-27 18:47:41 -0700130#define dlm_print_nodemap(m) _dlm_print_nodemap(m,#m)
Mark Fasheh8a9343f2006-05-01 14:55:10 -0700131static void _dlm_print_nodemap(unsigned long *map, const char *mapname)
Kurt Hackel95883712006-04-27 18:47:41 -0700132{
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
Mark Fasheh8a9343f2006-05-01 14:55:10 -0700141static void dlm_print_one_mle(struct dlm_master_list_entry *mle)
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800142{
Kurt Hackel95883712006-04-27 18:47:41 -0700143 int refs;
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800144 char *type;
145 char attached;
146 u8 master;
147 unsigned int namelen;
148 const char *name;
149 struct kref *k;
Kurt Hackel95883712006-04-27 18:47:41 -0700150 unsigned long *maybe = mle->maybe_map,
151 *vote = mle->vote_map,
152 *resp = mle->response_map,
153 *node = mle->node_map;
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800154
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
Kurt Hackel95883712006-04-27 18:47:41 -0700174 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");
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800186}
187
Mark Fasheh8a9343f2006-05-01 14:55:10 -0700188#if 0
189/* Code here is included but defined out as it aids debugging */
190
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800191static 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);
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800197 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
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800205int 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
224static kmem_cache_t *dlm_mle_cache = NULL;
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
240static int dlm_do_master_request(struct dlm_master_list_entry *mle, int to);
241
242
243static int dlm_wait_for_lock_mastery(struct dlm_ctxt *dlm,
244 struct dlm_lock_resource *res,
245 struct dlm_master_list_entry *mle,
246 int *blocked);
247static int dlm_restart_lock_mastery(struct dlm_ctxt *dlm,
248 struct dlm_lock_resource *res,
249 struct dlm_master_list_entry *mle,
250 int blocked);
251static int dlm_add_migration_mle(struct dlm_ctxt *dlm,
252 struct dlm_lock_resource *res,
253 struct dlm_master_list_entry *mle,
254 struct dlm_master_list_entry **oldmle,
255 const char *name, unsigned int namelen,
256 u8 new_master, u8 master);
257
258static u8 dlm_pick_migration_target(struct dlm_ctxt *dlm,
259 struct dlm_lock_resource *res);
260static void dlm_remove_nonlocal_locks(struct dlm_ctxt *dlm,
261 struct dlm_lock_resource *res);
262static int dlm_mark_lockres_migrating(struct dlm_ctxt *dlm,
263 struct dlm_lock_resource *res,
264 u8 target);
Kurt Hackelc03872f2006-03-06 14:08:49 -0800265static int dlm_pre_master_reco_lockres(struct dlm_ctxt *dlm,
266 struct dlm_lock_resource *res);
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800267
268
269int dlm_is_host_down(int errno)
270{
271 switch (errno) {
272 case -EBADF:
273 case -ECONNREFUSED:
274 case -ENOTCONN:
275 case -ECONNRESET:
276 case -EPIPE:
277 case -EHOSTDOWN:
278 case -EHOSTUNREACH:
279 case -ETIMEDOUT:
280 case -ECONNABORTED:
281 case -ENETDOWN:
282 case -ENETUNREACH:
283 case -ENETRESET:
284 case -ESHUTDOWN:
285 case -ENOPROTOOPT:
286 case -EINVAL: /* if returned from our tcp code,
287 this means there is no socket */
288 return 1;
289 }
290 return 0;
291}
292
293
294/*
295 * MASTER LIST FUNCTIONS
296 */
297
298
299/*
300 * regarding master list entries and heartbeat callbacks:
301 *
302 * in order to avoid sleeping and allocation that occurs in
303 * heartbeat, master list entries are simply attached to the
304 * dlm's established heartbeat callbacks. the mle is attached
305 * when it is created, and since the dlm->spinlock is held at
306 * that time, any heartbeat event will be properly discovered
307 * by the mle. the mle needs to be detached from the
308 * dlm->mle_hb_events list as soon as heartbeat events are no
309 * longer useful to the mle, and before the mle is freed.
310 *
311 * as a general rule, heartbeat events are no longer needed by
312 * the mle once an "answer" regarding the lock master has been
313 * received.
314 */
315static inline void __dlm_mle_attach_hb_events(struct dlm_ctxt *dlm,
316 struct dlm_master_list_entry *mle)
317{
318 assert_spin_locked(&dlm->spinlock);
319
320 list_add_tail(&mle->hb_events, &dlm->mle_hb_events);
321}
322
323
324static inline void __dlm_mle_detach_hb_events(struct dlm_ctxt *dlm,
325 struct dlm_master_list_entry *mle)
326{
327 if (!list_empty(&mle->hb_events))
328 list_del_init(&mle->hb_events);
329}
330
331
332static inline void dlm_mle_detach_hb_events(struct dlm_ctxt *dlm,
333 struct dlm_master_list_entry *mle)
334{
335 spin_lock(&dlm->spinlock);
336 __dlm_mle_detach_hb_events(dlm, mle);
337 spin_unlock(&dlm->spinlock);
338}
339
Kurt Hackela2bf0472006-04-27 18:51:26 -0700340static void dlm_get_mle_inuse(struct dlm_master_list_entry *mle)
341{
342 struct dlm_ctxt *dlm;
343 dlm = mle->dlm;
344
345 assert_spin_locked(&dlm->spinlock);
346 assert_spin_locked(&dlm->master_lock);
347 mle->inuse++;
348 kref_get(&mle->mle_refs);
349}
350
351static void dlm_put_mle_inuse(struct dlm_master_list_entry *mle)
352{
353 struct dlm_ctxt *dlm;
354 dlm = mle->dlm;
355
356 spin_lock(&dlm->spinlock);
357 spin_lock(&dlm->master_lock);
358 mle->inuse--;
359 __dlm_put_mle(mle);
360 spin_unlock(&dlm->master_lock);
361 spin_unlock(&dlm->spinlock);
362
363}
364
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800365/* remove from list and free */
366static void __dlm_put_mle(struct dlm_master_list_entry *mle)
367{
368 struct dlm_ctxt *dlm;
369 dlm = mle->dlm;
370
371 assert_spin_locked(&dlm->spinlock);
372 assert_spin_locked(&dlm->master_lock);
Kurt Hackelaa852352006-04-27 19:04:49 -0700373 if (!atomic_read(&mle->mle_refs.refcount)) {
374 /* this may or may not crash, but who cares.
375 * it's a BUG. */
376 mlog(ML_ERROR, "bad mle: %p\n", mle);
377 dlm_print_one_mle(mle);
378 BUG();
379 } else
380 kref_put(&mle->mle_refs, dlm_mle_release);
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800381}
382
383
384/* must not have any spinlocks coming in */
385static void dlm_put_mle(struct dlm_master_list_entry *mle)
386{
387 struct dlm_ctxt *dlm;
388 dlm = mle->dlm;
389
390 spin_lock(&dlm->spinlock);
391 spin_lock(&dlm->master_lock);
392 __dlm_put_mle(mle);
393 spin_unlock(&dlm->master_lock);
394 spin_unlock(&dlm->spinlock);
395}
396
397static inline void dlm_get_mle(struct dlm_master_list_entry *mle)
398{
399 kref_get(&mle->mle_refs);
400}
401
402static void dlm_init_mle(struct dlm_master_list_entry *mle,
403 enum dlm_mle_type type,
404 struct dlm_ctxt *dlm,
405 struct dlm_lock_resource *res,
406 const char *name,
407 unsigned int namelen)
408{
409 assert_spin_locked(&dlm->spinlock);
410
411 mle->dlm = dlm;
412 mle->type = type;
413 INIT_LIST_HEAD(&mle->list);
414 INIT_LIST_HEAD(&mle->hb_events);
415 memset(mle->maybe_map, 0, sizeof(mle->maybe_map));
416 spin_lock_init(&mle->spinlock);
417 init_waitqueue_head(&mle->wq);
418 atomic_set(&mle->woken, 0);
419 kref_init(&mle->mle_refs);
420 memset(mle->response_map, 0, sizeof(mle->response_map));
421 mle->master = O2NM_MAX_NODES;
422 mle->new_master = O2NM_MAX_NODES;
Kurt Hackela2bf0472006-04-27 18:51:26 -0700423 mle->inuse = 0;
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800424
425 if (mle->type == DLM_MLE_MASTER) {
426 BUG_ON(!res);
427 mle->u.res = res;
428 } else if (mle->type == DLM_MLE_BLOCK) {
429 BUG_ON(!name);
430 memcpy(mle->u.name.name, name, namelen);
431 mle->u.name.len = namelen;
432 } else /* DLM_MLE_MIGRATION */ {
433 BUG_ON(!name);
434 memcpy(mle->u.name.name, name, namelen);
435 mle->u.name.len = namelen;
436 }
437
438 /* copy off the node_map and register hb callbacks on our copy */
439 memcpy(mle->node_map, dlm->domain_map, sizeof(mle->node_map));
440 memcpy(mle->vote_map, dlm->domain_map, sizeof(mle->vote_map));
441 clear_bit(dlm->node_num, mle->vote_map);
442 clear_bit(dlm->node_num, mle->node_map);
443
444 /* attach the mle to the domain node up/down events */
445 __dlm_mle_attach_hb_events(dlm, mle);
446}
447
448
449/* returns 1 if found, 0 if not */
450static int dlm_find_mle(struct dlm_ctxt *dlm,
451 struct dlm_master_list_entry **mle,
452 char *name, unsigned int namelen)
453{
454 struct dlm_master_list_entry *tmpmle;
455 struct list_head *iter;
456
457 assert_spin_locked(&dlm->master_lock);
458
459 list_for_each(iter, &dlm->master_list) {
460 tmpmle = list_entry(iter, struct dlm_master_list_entry, list);
461 if (!dlm_mle_equal(dlm, tmpmle, name, namelen))
462 continue;
463 dlm_get_mle(tmpmle);
464 *mle = tmpmle;
465 return 1;
466 }
467 return 0;
468}
469
470void dlm_hb_event_notify_attached(struct dlm_ctxt *dlm, int idx, int node_up)
471{
472 struct dlm_master_list_entry *mle;
473 struct list_head *iter;
474
475 assert_spin_locked(&dlm->spinlock);
476
477 list_for_each(iter, &dlm->mle_hb_events) {
478 mle = list_entry(iter, struct dlm_master_list_entry,
479 hb_events);
480 if (node_up)
481 dlm_mle_node_up(dlm, mle, NULL, idx);
482 else
483 dlm_mle_node_down(dlm, mle, NULL, idx);
484 }
485}
486
487static void dlm_mle_node_down(struct dlm_ctxt *dlm,
488 struct dlm_master_list_entry *mle,
489 struct o2nm_node *node, int idx)
490{
491 spin_lock(&mle->spinlock);
492
493 if (!test_bit(idx, mle->node_map))
494 mlog(0, "node %u already removed from nodemap!\n", idx);
495 else
496 clear_bit(idx, mle->node_map);
497
498 spin_unlock(&mle->spinlock);
499}
500
501static void dlm_mle_node_up(struct dlm_ctxt *dlm,
502 struct dlm_master_list_entry *mle,
503 struct o2nm_node *node, int idx)
504{
505 spin_lock(&mle->spinlock);
506
507 if (test_bit(idx, mle->node_map))
508 mlog(0, "node %u already in node map!\n", idx);
509 else
510 set_bit(idx, mle->node_map);
511
512 spin_unlock(&mle->spinlock);
513}
514
515
516int dlm_init_mle_cache(void)
517{
518 dlm_mle_cache = kmem_cache_create("dlm_mle_cache",
519 sizeof(struct dlm_master_list_entry),
520 0, SLAB_HWCACHE_ALIGN,
521 NULL, NULL);
522 if (dlm_mle_cache == NULL)
523 return -ENOMEM;
524 return 0;
525}
526
527void dlm_destroy_mle_cache(void)
528{
529 if (dlm_mle_cache)
530 kmem_cache_destroy(dlm_mle_cache);
531}
532
533static void dlm_mle_release(struct kref *kref)
534{
535 struct dlm_master_list_entry *mle;
536 struct dlm_ctxt *dlm;
537
538 mlog_entry_void();
539
540 mle = container_of(kref, struct dlm_master_list_entry, mle_refs);
541 dlm = mle->dlm;
542
543 if (mle->type != DLM_MLE_MASTER) {
544 mlog(0, "calling mle_release for %.*s, type %d\n",
545 mle->u.name.len, mle->u.name.name, mle->type);
546 } else {
547 mlog(0, "calling mle_release for %.*s, type %d\n",
548 mle->u.res->lockname.len,
549 mle->u.res->lockname.name, mle->type);
550 }
551 assert_spin_locked(&dlm->spinlock);
552 assert_spin_locked(&dlm->master_lock);
553
554 /* remove from list if not already */
555 if (!list_empty(&mle->list))
556 list_del_init(&mle->list);
557
558 /* detach the mle from the domain node up/down events */
559 __dlm_mle_detach_hb_events(dlm, mle);
560
561 /* NOTE: kfree under spinlock here.
562 * if this is bad, we can move this to a freelist. */
563 kmem_cache_free(dlm_mle_cache, mle);
564}
565
566
567/*
568 * LOCK RESOURCE FUNCTIONS
569 */
570
571static void dlm_set_lockres_owner(struct dlm_ctxt *dlm,
572 struct dlm_lock_resource *res,
573 u8 owner)
574{
575 assert_spin_locked(&res->spinlock);
576
577 mlog_entry("%.*s, %u\n", res->lockname.len, res->lockname.name, owner);
578
579 if (owner == dlm->node_num)
580 atomic_inc(&dlm->local_resources);
581 else if (owner == DLM_LOCK_RES_OWNER_UNKNOWN)
582 atomic_inc(&dlm->unknown_resources);
583 else
584 atomic_inc(&dlm->remote_resources);
585
586 res->owner = owner;
587}
588
589void dlm_change_lockres_owner(struct dlm_ctxt *dlm,
590 struct dlm_lock_resource *res, u8 owner)
591{
592 assert_spin_locked(&res->spinlock);
593
594 if (owner == res->owner)
595 return;
596
597 if (res->owner == dlm->node_num)
598 atomic_dec(&dlm->local_resources);
599 else if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN)
600 atomic_dec(&dlm->unknown_resources);
601 else
602 atomic_dec(&dlm->remote_resources);
603
604 dlm_set_lockres_owner(dlm, res, owner);
605}
606
607
608static void dlm_lockres_release(struct kref *kref)
609{
610 struct dlm_lock_resource *res;
611
612 res = container_of(kref, struct dlm_lock_resource, refs);
613
614 /* This should not happen -- all lockres' have a name
615 * associated with them at init time. */
616 BUG_ON(!res->lockname.name);
617
618 mlog(0, "destroying lockres %.*s\n", res->lockname.len,
619 res->lockname.name);
620
Kurt Hackela7f90d82006-04-27 19:24:21 -0700621 if (!hlist_unhashed(&res->hash_node) ||
622 !list_empty(&res->granted) ||
623 !list_empty(&res->converting) ||
624 !list_empty(&res->blocked) ||
625 !list_empty(&res->dirty) ||
626 !list_empty(&res->recovering) ||
627 !list_empty(&res->purge)) {
628 mlog(ML_ERROR,
629 "Going to BUG for resource %.*s."
630 " We're on a list! [%c%c%c%c%c%c%c]\n",
631 res->lockname.len, res->lockname.name,
632 !hlist_unhashed(&res->hash_node) ? 'H' : ' ',
633 !list_empty(&res->granted) ? 'G' : ' ',
634 !list_empty(&res->converting) ? 'C' : ' ',
635 !list_empty(&res->blocked) ? 'B' : ' ',
636 !list_empty(&res->dirty) ? 'D' : ' ',
637 !list_empty(&res->recovering) ? 'R' : ' ',
638 !list_empty(&res->purge) ? 'P' : ' ');
639
640 dlm_print_one_lock_resource(res);
641 }
642
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800643 /* By the time we're ready to blow this guy away, we shouldn't
644 * be on any lists. */
Mark Fasheh81f20942006-02-28 17:31:22 -0800645 BUG_ON(!hlist_unhashed(&res->hash_node));
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800646 BUG_ON(!list_empty(&res->granted));
647 BUG_ON(!list_empty(&res->converting));
648 BUG_ON(!list_empty(&res->blocked));
649 BUG_ON(!list_empty(&res->dirty));
650 BUG_ON(!list_empty(&res->recovering));
651 BUG_ON(!list_empty(&res->purge));
652
653 kfree(res->lockname.name);
654
655 kfree(res);
656}
657
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800658void dlm_lockres_put(struct dlm_lock_resource *res)
659{
660 kref_put(&res->refs, dlm_lockres_release);
661}
662
663static void dlm_init_lockres(struct dlm_ctxt *dlm,
664 struct dlm_lock_resource *res,
665 const char *name, unsigned int namelen)
666{
667 char *qname;
668
669 /* If we memset here, we lose our reference to the kmalloc'd
670 * res->lockname.name, so be sure to init every field
671 * correctly! */
672
673 qname = (char *) res->lockname.name;
674 memcpy(qname, name, namelen);
675
676 res->lockname.len = namelen;
Mark Fasheha3d33292006-03-09 17:55:56 -0800677 res->lockname.hash = dlm_lockid_hash(name, namelen);
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800678
679 init_waitqueue_head(&res->wq);
680 spin_lock_init(&res->spinlock);
Mark Fasheh81f20942006-02-28 17:31:22 -0800681 INIT_HLIST_NODE(&res->hash_node);
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800682 INIT_LIST_HEAD(&res->granted);
683 INIT_LIST_HEAD(&res->converting);
684 INIT_LIST_HEAD(&res->blocked);
685 INIT_LIST_HEAD(&res->dirty);
686 INIT_LIST_HEAD(&res->recovering);
687 INIT_LIST_HEAD(&res->purge);
688 atomic_set(&res->asts_reserved, 0);
689 res->migration_pending = 0;
690
691 kref_init(&res->refs);
692
693 /* just for consistency */
694 spin_lock(&res->spinlock);
695 dlm_set_lockres_owner(dlm, res, DLM_LOCK_RES_OWNER_UNKNOWN);
696 spin_unlock(&res->spinlock);
697
698 res->state = DLM_LOCK_RES_IN_PROGRESS;
699
700 res->last_used = 0;
701
702 memset(res->lvb, 0, DLM_LVB_LEN);
703}
704
705struct dlm_lock_resource *dlm_new_lockres(struct dlm_ctxt *dlm,
706 const char *name,
707 unsigned int namelen)
708{
709 struct dlm_lock_resource *res;
710
Kurt Hackelad8100e2006-05-01 14:25:21 -0700711 res = kmalloc(sizeof(struct dlm_lock_resource), GFP_NOFS);
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800712 if (!res)
713 return NULL;
714
Kurt Hackelad8100e2006-05-01 14:25:21 -0700715 res->lockname.name = kmalloc(namelen, GFP_NOFS);
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800716 if (!res->lockname.name) {
717 kfree(res);
718 return NULL;
719 }
720
721 dlm_init_lockres(dlm, res, name, namelen);
722 return res;
723}
724
725/*
726 * lookup a lock resource by name.
727 * may already exist in the hashtable.
728 * lockid is null terminated
729 *
730 * if not, allocate enough for the lockres and for
731 * the temporary structure used in doing the mastering.
732 *
733 * also, do a lookup in the dlm->master_list to see
734 * if another node has begun mastering the same lock.
735 * if so, there should be a block entry in there
736 * for this name, and we should *not* attempt to master
737 * the lock here. need to wait around for that node
738 * to assert_master (or die).
739 *
740 */
741struct dlm_lock_resource * dlm_get_lock_resource(struct dlm_ctxt *dlm,
742 const char *lockid,
Mark Fasheh3384f3d2006-09-08 11:38:29 -0700743 int namelen,
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800744 int flags)
745{
746 struct dlm_lock_resource *tmpres=NULL, *res=NULL;
747 struct dlm_master_list_entry *mle = NULL;
748 struct dlm_master_list_entry *alloc_mle = NULL;
749 int blocked = 0;
750 int ret, nodenum;
751 struct dlm_node_iter iter;
Mark Fasheh3384f3d2006-09-08 11:38:29 -0700752 unsigned int hash;
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800753 int tries = 0;
Kurt Hackelc03872f2006-03-06 14:08:49 -0800754 int bit, wait_on_recovery = 0;
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800755
756 BUG_ON(!lockid);
757
Mark Fasheha3d33292006-03-09 17:55:56 -0800758 hash = dlm_lockid_hash(lockid, namelen);
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800759
760 mlog(0, "get lockres %s (len %d)\n", lockid, namelen);
761
762lookup:
763 spin_lock(&dlm->spinlock);
Mark Fasheha3d33292006-03-09 17:55:56 -0800764 tmpres = __dlm_lookup_lockres(dlm, lockid, namelen, hash);
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800765 if (tmpres) {
766 spin_unlock(&dlm->spinlock);
767 mlog(0, "found in hash!\n");
768 if (res)
769 dlm_lockres_put(res);
770 res = tmpres;
771 goto leave;
772 }
773
774 if (!res) {
775 spin_unlock(&dlm->spinlock);
776 mlog(0, "allocating a new resource\n");
777 /* nothing found and we need to allocate one. */
778 alloc_mle = (struct dlm_master_list_entry *)
Kurt Hackelad8100e2006-05-01 14:25:21 -0700779 kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800780 if (!alloc_mle)
781 goto leave;
782 res = dlm_new_lockres(dlm, lockid, namelen);
783 if (!res)
784 goto leave;
785 goto lookup;
786 }
787
788 mlog(0, "no lockres found, allocated our own: %p\n", res);
789
790 if (flags & LKM_LOCAL) {
791 /* caller knows it's safe to assume it's not mastered elsewhere
792 * DONE! return right away */
793 spin_lock(&res->spinlock);
794 dlm_change_lockres_owner(dlm, res, dlm->node_num);
795 __dlm_insert_lockres(dlm, res);
796 spin_unlock(&res->spinlock);
797 spin_unlock(&dlm->spinlock);
798 /* lockres still marked IN_PROGRESS */
799 goto wake_waiters;
800 }
801
802 /* check master list to see if another node has started mastering it */
803 spin_lock(&dlm->master_lock);
804
805 /* if we found a block, wait for lock to be mastered by another node */
806 blocked = dlm_find_mle(dlm, &mle, (char *)lockid, namelen);
807 if (blocked) {
808 if (mle->type == DLM_MLE_MASTER) {
809 mlog(ML_ERROR, "master entry for nonexistent lock!\n");
810 BUG();
811 } else if (mle->type == DLM_MLE_MIGRATION) {
812 /* migration is in progress! */
813 /* the good news is that we now know the
814 * "current" master (mle->master). */
815
816 spin_unlock(&dlm->master_lock);
817 assert_spin_locked(&dlm->spinlock);
818
819 /* set the lockres owner and hash it */
820 spin_lock(&res->spinlock);
821 dlm_set_lockres_owner(dlm, res, mle->master);
822 __dlm_insert_lockres(dlm, res);
823 spin_unlock(&res->spinlock);
824 spin_unlock(&dlm->spinlock);
825
826 /* master is known, detach */
827 dlm_mle_detach_hb_events(dlm, mle);
828 dlm_put_mle(mle);
829 mle = NULL;
830 goto wake_waiters;
831 }
832 } else {
833 /* go ahead and try to master lock on this node */
834 mle = alloc_mle;
835 /* make sure this does not get freed below */
836 alloc_mle = NULL;
837 dlm_init_mle(mle, DLM_MLE_MASTER, dlm, res, NULL, 0);
838 set_bit(dlm->node_num, mle->maybe_map);
839 list_add(&mle->list, &dlm->master_list);
Kurt Hackelc03872f2006-03-06 14:08:49 -0800840
841 /* still holding the dlm spinlock, check the recovery map
842 * to see if there are any nodes that still need to be
843 * considered. these will not appear in the mle nodemap
844 * but they might own this lockres. wait on them. */
845 bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0);
846 if (bit < O2NM_MAX_NODES) {
847 mlog(ML_NOTICE, "%s:%.*s: at least one node (%d) to"
848 "recover before lock mastery can begin\n",
849 dlm->name, namelen, (char *)lockid, bit);
850 wait_on_recovery = 1;
851 }
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800852 }
853
854 /* at this point there is either a DLM_MLE_BLOCK or a
855 * DLM_MLE_MASTER on the master list, so it's safe to add the
856 * lockres to the hashtable. anyone who finds the lock will
857 * still have to wait on the IN_PROGRESS. */
858
859 /* finally add the lockres to its hash bucket */
860 __dlm_insert_lockres(dlm, res);
861 /* get an extra ref on the mle in case this is a BLOCK
862 * if so, the creator of the BLOCK may try to put the last
863 * ref at this time in the assert master handler, so we
864 * need an extra one to keep from a bad ptr deref. */
Kurt Hackela2bf0472006-04-27 18:51:26 -0700865 dlm_get_mle_inuse(mle);
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800866 spin_unlock(&dlm->master_lock);
867 spin_unlock(&dlm->spinlock);
868
Kurt Hackele7e69eb2006-05-01 11:49:52 -0700869redo_request:
Kurt Hackelc03872f2006-03-06 14:08:49 -0800870 while (wait_on_recovery) {
871 /* any cluster changes that occurred after dropping the
872 * dlm spinlock would be detectable be a change on the mle,
873 * so we only need to clear out the recovery map once. */
874 if (dlm_is_recovery_lock(lockid, namelen)) {
875 mlog(ML_NOTICE, "%s: recovery map is not empty, but "
876 "must master $RECOVERY lock now\n", dlm->name);
877 if (!dlm_pre_master_reco_lockres(dlm, res))
878 wait_on_recovery = 0;
879 else {
880 mlog(0, "%s: waiting 500ms for heartbeat state "
881 "change\n", dlm->name);
882 msleep(500);
883 }
884 continue;
885 }
886
887 dlm_kick_recovery_thread(dlm);
Kurt Hackelaa087b82006-05-01 12:02:07 -0700888 msleep(1000);
Kurt Hackelc03872f2006-03-06 14:08:49 -0800889 dlm_wait_for_recovery(dlm);
890
891 spin_lock(&dlm->spinlock);
892 bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0);
893 if (bit < O2NM_MAX_NODES) {
894 mlog(ML_NOTICE, "%s:%.*s: at least one node (%d) to"
895 "recover before lock mastery can begin\n",
896 dlm->name, namelen, (char *)lockid, bit);
897 wait_on_recovery = 1;
898 } else
899 wait_on_recovery = 0;
900 spin_unlock(&dlm->spinlock);
Kurt Hackelb7084ab2006-05-01 13:54:07 -0700901
902 if (wait_on_recovery)
903 dlm_wait_for_node_recovery(dlm, bit, 10000);
Kurt Hackelc03872f2006-03-06 14:08:49 -0800904 }
905
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800906 /* must wait for lock to be mastered elsewhere */
907 if (blocked)
908 goto wait;
909
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800910 ret = -EINVAL;
911 dlm_node_iter_init(mle->vote_map, &iter);
912 while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
913 ret = dlm_do_master_request(mle, nodenum);
914 if (ret < 0)
915 mlog_errno(ret);
916 if (mle->master != O2NM_MAX_NODES) {
917 /* found a master ! */
Kurt Hackel9c6510a2006-03-02 18:09:26 -0800918 if (mle->master <= nodenum)
919 break;
920 /* if our master request has not reached the master
921 * yet, keep going until it does. this is how the
922 * master will know that asserts are needed back to
923 * the lower nodes. */
924 mlog(0, "%s:%.*s: requests only up to %u but master "
925 "is %u, keep going\n", dlm->name, namelen,
926 lockid, nodenum, mle->master);
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800927 }
928 }
929
930wait:
931 /* keep going until the response map includes all nodes */
932 ret = dlm_wait_for_lock_mastery(dlm, res, mle, &blocked);
933 if (ret < 0) {
Kurt Hackele7e69eb2006-05-01 11:49:52 -0700934 wait_on_recovery = 1;
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800935 mlog(0, "%s:%.*s: node map changed, redo the "
936 "master request now, blocked=%d\n",
937 dlm->name, res->lockname.len,
938 res->lockname.name, blocked);
939 if (++tries > 20) {
940 mlog(ML_ERROR, "%s:%.*s: spinning on "
941 "dlm_wait_for_lock_mastery, blocked=%d\n",
942 dlm->name, res->lockname.len,
943 res->lockname.name, blocked);
944 dlm_print_one_lock_resource(res);
Mark Fasheh8a9343f2006-05-01 14:55:10 -0700945 dlm_print_one_mle(mle);
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800946 tries = 0;
947 }
948 goto redo_request;
949 }
950
951 mlog(0, "lockres mastered by %u\n", res->owner);
952 /* make sure we never continue without this */
953 BUG_ON(res->owner == O2NM_MAX_NODES);
954
955 /* master is known, detach if not already detached */
956 dlm_mle_detach_hb_events(dlm, mle);
957 dlm_put_mle(mle);
958 /* put the extra ref */
Kurt Hackela2bf0472006-04-27 18:51:26 -0700959 dlm_put_mle_inuse(mle);
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800960
961wake_waiters:
962 spin_lock(&res->spinlock);
963 res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
964 spin_unlock(&res->spinlock);
965 wake_up(&res->wq);
966
967leave:
968 /* need to free the unused mle */
969 if (alloc_mle)
970 kmem_cache_free(dlm_mle_cache, alloc_mle);
971
972 return res;
973}
974
975
976#define DLM_MASTERY_TIMEOUT_MS 5000
977
978static int dlm_wait_for_lock_mastery(struct dlm_ctxt *dlm,
979 struct dlm_lock_resource *res,
980 struct dlm_master_list_entry *mle,
981 int *blocked)
982{
983 u8 m;
984 int ret, bit;
985 int map_changed, voting_done;
986 int assert, sleep;
987
988recheck:
989 ret = 0;
990 assert = 0;
991
992 /* check if another node has already become the owner */
993 spin_lock(&res->spinlock);
994 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
Kurt Hackel9c6510a2006-03-02 18:09:26 -0800995 mlog(0, "%s:%.*s: owner is suddenly %u\n", dlm->name,
996 res->lockname.len, res->lockname.name, res->owner);
Kurt Hackel6714d8e2005-12-15 14:31:23 -0800997 spin_unlock(&res->spinlock);
Kurt Hackel9c6510a2006-03-02 18:09:26 -0800998 /* this will cause the master to re-assert across
999 * the whole cluster, freeing up mles */
Kurt Hackel588e0092006-05-01 11:22:06 -07001000 if (res->owner != dlm->node_num) {
1001 ret = dlm_do_master_request(mle, res->owner);
1002 if (ret < 0) {
1003 /* give recovery a chance to run */
1004 mlog(ML_ERROR, "link to %u went down?: %d\n", res->owner, ret);
1005 msleep(500);
1006 goto recheck;
1007 }
Kurt Hackel9c6510a2006-03-02 18:09:26 -08001008 }
1009 ret = 0;
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001010 goto leave;
1011 }
1012 spin_unlock(&res->spinlock);
1013
1014 spin_lock(&mle->spinlock);
1015 m = mle->master;
1016 map_changed = (memcmp(mle->vote_map, mle->node_map,
1017 sizeof(mle->vote_map)) != 0);
1018 voting_done = (memcmp(mle->vote_map, mle->response_map,
1019 sizeof(mle->vote_map)) == 0);
1020
1021 /* restart if we hit any errors */
1022 if (map_changed) {
1023 int b;
1024 mlog(0, "%s: %.*s: node map changed, restarting\n",
1025 dlm->name, res->lockname.len, res->lockname.name);
1026 ret = dlm_restart_lock_mastery(dlm, res, mle, *blocked);
1027 b = (mle->type == DLM_MLE_BLOCK);
1028 if ((*blocked && !b) || (!*blocked && b)) {
1029 mlog(0, "%s:%.*s: status change: old=%d new=%d\n",
1030 dlm->name, res->lockname.len, res->lockname.name,
1031 *blocked, b);
1032 *blocked = b;
1033 }
1034 spin_unlock(&mle->spinlock);
1035 if (ret < 0) {
1036 mlog_errno(ret);
1037 goto leave;
1038 }
1039 mlog(0, "%s:%.*s: restart lock mastery succeeded, "
1040 "rechecking now\n", dlm->name, res->lockname.len,
1041 res->lockname.name);
1042 goto recheck;
Kurt Hackelaa852352006-04-27 19:04:49 -07001043 } else {
1044 if (!voting_done) {
1045 mlog(0, "map not changed and voting not done "
1046 "for %s:%.*s\n", dlm->name, res->lockname.len,
1047 res->lockname.name);
1048 }
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001049 }
1050
1051 if (m != O2NM_MAX_NODES) {
1052 /* another node has done an assert!
1053 * all done! */
1054 sleep = 0;
1055 } else {
1056 sleep = 1;
1057 /* have all nodes responded? */
1058 if (voting_done && !*blocked) {
1059 bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0);
1060 if (dlm->node_num <= bit) {
1061 /* my node number is lowest.
1062 * now tell other nodes that I am
1063 * mastering this. */
1064 mle->master = dlm->node_num;
1065 assert = 1;
1066 sleep = 0;
1067 }
1068 /* if voting is done, but we have not received
1069 * an assert master yet, we must sleep */
1070 }
1071 }
1072
1073 spin_unlock(&mle->spinlock);
1074
1075 /* sleep if we haven't finished voting yet */
1076 if (sleep) {
1077 unsigned long timeo = msecs_to_jiffies(DLM_MASTERY_TIMEOUT_MS);
1078
1079 /*
1080 if (atomic_read(&mle->mle_refs.refcount) < 2)
1081 mlog(ML_ERROR, "mle (%p) refs=%d, name=%.*s\n", mle,
1082 atomic_read(&mle->mle_refs.refcount),
1083 res->lockname.len, res->lockname.name);
1084 */
1085 atomic_set(&mle->woken, 0);
1086 (void)wait_event_timeout(mle->wq,
1087 (atomic_read(&mle->woken) == 1),
1088 timeo);
1089 if (res->owner == O2NM_MAX_NODES) {
1090 mlog(0, "waiting again\n");
1091 goto recheck;
1092 }
1093 mlog(0, "done waiting, master is %u\n", res->owner);
1094 ret = 0;
1095 goto leave;
1096 }
1097
1098 ret = 0; /* done */
1099 if (assert) {
1100 m = dlm->node_num;
1101 mlog(0, "about to master %.*s here, this=%u\n",
1102 res->lockname.len, res->lockname.name, m);
1103 ret = dlm_do_assert_master(dlm, res->lockname.name,
1104 res->lockname.len, mle->vote_map, 0);
1105 if (ret) {
1106 /* This is a failure in the network path,
1107 * not in the response to the assert_master
1108 * (any nonzero response is a BUG on this node).
1109 * Most likely a socket just got disconnected
1110 * due to node death. */
1111 mlog_errno(ret);
1112 }
1113 /* no longer need to restart lock mastery.
1114 * all living nodes have been contacted. */
1115 ret = 0;
1116 }
1117
1118 /* set the lockres owner */
1119 spin_lock(&res->spinlock);
1120 dlm_change_lockres_owner(dlm, res, m);
1121 spin_unlock(&res->spinlock);
1122
1123leave:
1124 return ret;
1125}
1126
1127struct dlm_bitmap_diff_iter
1128{
1129 int curnode;
1130 unsigned long *orig_bm;
1131 unsigned long *cur_bm;
1132 unsigned long diff_bm[BITS_TO_LONGS(O2NM_MAX_NODES)];
1133};
1134
1135enum dlm_node_state_change
1136{
1137 NODE_DOWN = -1,
1138 NODE_NO_CHANGE = 0,
1139 NODE_UP
1140};
1141
1142static void dlm_bitmap_diff_iter_init(struct dlm_bitmap_diff_iter *iter,
1143 unsigned long *orig_bm,
1144 unsigned long *cur_bm)
1145{
1146 unsigned long p1, p2;
1147 int i;
1148
1149 iter->curnode = -1;
1150 iter->orig_bm = orig_bm;
1151 iter->cur_bm = cur_bm;
1152
1153 for (i = 0; i < BITS_TO_LONGS(O2NM_MAX_NODES); i++) {
1154 p1 = *(iter->orig_bm + i);
1155 p2 = *(iter->cur_bm + i);
1156 iter->diff_bm[i] = (p1 & ~p2) | (p2 & ~p1);
1157 }
1158}
1159
1160static int dlm_bitmap_diff_iter_next(struct dlm_bitmap_diff_iter *iter,
1161 enum dlm_node_state_change *state)
1162{
1163 int bit;
1164
1165 if (iter->curnode >= O2NM_MAX_NODES)
1166 return -ENOENT;
1167
1168 bit = find_next_bit(iter->diff_bm, O2NM_MAX_NODES,
1169 iter->curnode+1);
1170 if (bit >= O2NM_MAX_NODES) {
1171 iter->curnode = O2NM_MAX_NODES;
1172 return -ENOENT;
1173 }
1174
1175 /* if it was there in the original then this node died */
1176 if (test_bit(bit, iter->orig_bm))
1177 *state = NODE_DOWN;
1178 else
1179 *state = NODE_UP;
1180
1181 iter->curnode = bit;
1182 return bit;
1183}
1184
1185
1186static int dlm_restart_lock_mastery(struct dlm_ctxt *dlm,
1187 struct dlm_lock_resource *res,
1188 struct dlm_master_list_entry *mle,
1189 int blocked)
1190{
1191 struct dlm_bitmap_diff_iter bdi;
1192 enum dlm_node_state_change sc;
1193 int node;
1194 int ret = 0;
1195
1196 mlog(0, "something happened such that the "
1197 "master process may need to be restarted!\n");
1198
1199 assert_spin_locked(&mle->spinlock);
1200
1201 dlm_bitmap_diff_iter_init(&bdi, mle->vote_map, mle->node_map);
1202 node = dlm_bitmap_diff_iter_next(&bdi, &sc);
1203 while (node >= 0) {
1204 if (sc == NODE_UP) {
Kurt Hackele2faea42006-01-12 14:24:55 -08001205 /* a node came up. clear any old vote from
1206 * the response map and set it in the vote map
1207 * then restart the mastery. */
1208 mlog(ML_NOTICE, "node %d up while restarting\n", node);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001209
1210 /* redo the master request, but only for the new node */
1211 mlog(0, "sending request to new node\n");
1212 clear_bit(node, mle->response_map);
1213 set_bit(node, mle->vote_map);
1214 } else {
1215 mlog(ML_ERROR, "node down! %d\n", node);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001216 if (blocked) {
1217 int lowest = find_next_bit(mle->maybe_map,
1218 O2NM_MAX_NODES, 0);
1219
1220 /* act like it was never there */
1221 clear_bit(node, mle->maybe_map);
1222
Kurt Hackele7e69eb2006-05-01 11:49:52 -07001223 if (node == lowest) {
1224 mlog(0, "expected master %u died"
1225 " while this node was blocked "
1226 "waiting on it!\n", node);
1227 lowest = find_next_bit(mle->maybe_map,
1228 O2NM_MAX_NODES,
1229 lowest+1);
1230 if (lowest < O2NM_MAX_NODES) {
1231 mlog(0, "%s:%.*s:still "
1232 "blocked. waiting on %u "
1233 "now\n", dlm->name,
1234 res->lockname.len,
1235 res->lockname.name,
1236 lowest);
1237 } else {
1238 /* mle is an MLE_BLOCK, but
1239 * there is now nothing left to
1240 * block on. we need to return
1241 * all the way back out and try
1242 * again with an MLE_MASTER.
1243 * dlm_do_local_recovery_cleanup
1244 * has already run, so the mle
1245 * refcount is ok */
1246 mlog(0, "%s:%.*s: no "
1247 "longer blocking. try to "
1248 "master this here\n",
1249 dlm->name,
1250 res->lockname.len,
1251 res->lockname.name);
1252 mle->type = DLM_MLE_MASTER;
1253 mle->u.res = res;
1254 }
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001255 }
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001256 }
1257
Kurt Hackele7e69eb2006-05-01 11:49:52 -07001258 /* now blank out everything, as if we had never
1259 * contacted anyone */
1260 memset(mle->maybe_map, 0, sizeof(mle->maybe_map));
1261 memset(mle->response_map, 0, sizeof(mle->response_map));
1262 /* reset the vote_map to the current node_map */
1263 memcpy(mle->vote_map, mle->node_map,
1264 sizeof(mle->node_map));
1265 /* put myself into the maybe map */
1266 if (mle->type != DLM_MLE_BLOCK)
1267 set_bit(dlm->node_num, mle->maybe_map);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001268 }
1269 ret = -EAGAIN;
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001270 node = dlm_bitmap_diff_iter_next(&bdi, &sc);
1271 }
1272 return ret;
1273}
1274
1275
1276/*
1277 * DLM_MASTER_REQUEST_MSG
1278 *
1279 * returns: 0 on success,
1280 * -errno on a network error
1281 *
1282 * on error, the caller should assume the target node is "dead"
1283 *
1284 */
1285
1286static int dlm_do_master_request(struct dlm_master_list_entry *mle, int to)
1287{
1288 struct dlm_ctxt *dlm = mle->dlm;
1289 struct dlm_master_request request;
1290 int ret, response=0, resend;
1291
1292 memset(&request, 0, sizeof(request));
1293 request.node_idx = dlm->node_num;
1294
1295 BUG_ON(mle->type == DLM_MLE_MIGRATION);
1296
1297 if (mle->type != DLM_MLE_MASTER) {
1298 request.namelen = mle->u.name.len;
1299 memcpy(request.name, mle->u.name.name, request.namelen);
1300 } else {
1301 request.namelen = mle->u.res->lockname.len;
1302 memcpy(request.name, mle->u.res->lockname.name,
1303 request.namelen);
1304 }
1305
1306again:
1307 ret = o2net_send_message(DLM_MASTER_REQUEST_MSG, dlm->key, &request,
1308 sizeof(request), to, &response);
1309 if (ret < 0) {
1310 if (ret == -ESRCH) {
1311 /* should never happen */
1312 mlog(ML_ERROR, "TCP stack not ready!\n");
1313 BUG();
1314 } else if (ret == -EINVAL) {
1315 mlog(ML_ERROR, "bad args passed to o2net!\n");
1316 BUG();
1317 } else if (ret == -ENOMEM) {
1318 mlog(ML_ERROR, "out of memory while trying to send "
1319 "network message! retrying\n");
1320 /* this is totally crude */
1321 msleep(50);
1322 goto again;
1323 } else if (!dlm_is_host_down(ret)) {
1324 /* not a network error. bad. */
1325 mlog_errno(ret);
1326 mlog(ML_ERROR, "unhandled error!");
1327 BUG();
1328 }
1329 /* all other errors should be network errors,
1330 * and likely indicate node death */
1331 mlog(ML_ERROR, "link to %d went down!\n", to);
1332 goto out;
1333 }
1334
1335 ret = 0;
1336 resend = 0;
1337 spin_lock(&mle->spinlock);
1338 switch (response) {
1339 case DLM_MASTER_RESP_YES:
1340 set_bit(to, mle->response_map);
1341 mlog(0, "node %u is the master, response=YES\n", to);
1342 mle->master = to;
1343 break;
1344 case DLM_MASTER_RESP_NO:
1345 mlog(0, "node %u not master, response=NO\n", to);
1346 set_bit(to, mle->response_map);
1347 break;
1348 case DLM_MASTER_RESP_MAYBE:
1349 mlog(0, "node %u not master, response=MAYBE\n", to);
1350 set_bit(to, mle->response_map);
1351 set_bit(to, mle->maybe_map);
1352 break;
1353 case DLM_MASTER_RESP_ERROR:
1354 mlog(0, "node %u hit an error, resending\n", to);
1355 resend = 1;
1356 response = 0;
1357 break;
1358 default:
1359 mlog(ML_ERROR, "bad response! %u\n", response);
1360 BUG();
1361 }
1362 spin_unlock(&mle->spinlock);
1363 if (resend) {
1364 /* this is also totally crude */
1365 msleep(50);
1366 goto again;
1367 }
1368
1369out:
1370 return ret;
1371}
1372
1373/*
1374 * locks that can be taken here:
1375 * dlm->spinlock
1376 * res->spinlock
1377 * mle->spinlock
1378 * dlm->master_list
1379 *
1380 * if possible, TRIM THIS DOWN!!!
1381 */
1382int dlm_master_request_handler(struct o2net_msg *msg, u32 len, void *data)
1383{
1384 u8 response = DLM_MASTER_RESP_MAYBE;
1385 struct dlm_ctxt *dlm = data;
Kurt Hackel9c6510a2006-03-02 18:09:26 -08001386 struct dlm_lock_resource *res = NULL;
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001387 struct dlm_master_request *request = (struct dlm_master_request *) msg->buf;
1388 struct dlm_master_list_entry *mle = NULL, *tmpmle = NULL;
1389 char *name;
Mark Fasheha3d33292006-03-09 17:55:56 -08001390 unsigned int namelen, hash;
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001391 int found, ret;
1392 int set_maybe;
Kurt Hackel9c6510a2006-03-02 18:09:26 -08001393 int dispatch_assert = 0;
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001394
1395 if (!dlm_grab(dlm))
1396 return DLM_MASTER_RESP_NO;
1397
1398 if (!dlm_domain_fully_joined(dlm)) {
1399 response = DLM_MASTER_RESP_NO;
1400 goto send_response;
1401 }
1402
1403 name = request->name;
1404 namelen = request->namelen;
Mark Fasheha3d33292006-03-09 17:55:56 -08001405 hash = dlm_lockid_hash(name, namelen);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001406
1407 if (namelen > DLM_LOCKID_NAME_MAX) {
1408 response = DLM_IVBUFLEN;
1409 goto send_response;
1410 }
1411
1412way_up_top:
1413 spin_lock(&dlm->spinlock);
Mark Fasheha3d33292006-03-09 17:55:56 -08001414 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001415 if (res) {
1416 spin_unlock(&dlm->spinlock);
1417
1418 /* take care of the easy cases up front */
1419 spin_lock(&res->spinlock);
1420 if (res->state & DLM_LOCK_RES_RECOVERING) {
1421 spin_unlock(&res->spinlock);
1422 mlog(0, "returning DLM_MASTER_RESP_ERROR since res is "
1423 "being recovered\n");
1424 response = DLM_MASTER_RESP_ERROR;
1425 if (mle)
1426 kmem_cache_free(dlm_mle_cache, mle);
1427 goto send_response;
1428 }
1429
1430 if (res->owner == dlm->node_num) {
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001431 spin_unlock(&res->spinlock);
1432 // mlog(0, "this node is the master\n");
1433 response = DLM_MASTER_RESP_YES;
1434 if (mle)
1435 kmem_cache_free(dlm_mle_cache, mle);
1436
1437 /* this node is the owner.
1438 * there is some extra work that needs to
1439 * happen now. the requesting node has
1440 * caused all nodes up to this one to
1441 * create mles. this node now needs to
1442 * go back and clean those up. */
Kurt Hackel9c6510a2006-03-02 18:09:26 -08001443 dispatch_assert = 1;
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001444 goto send_response;
1445 } else if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
1446 spin_unlock(&res->spinlock);
1447 // mlog(0, "node %u is the master\n", res->owner);
1448 response = DLM_MASTER_RESP_NO;
1449 if (mle)
1450 kmem_cache_free(dlm_mle_cache, mle);
1451 goto send_response;
1452 }
1453
1454 /* ok, there is no owner. either this node is
1455 * being blocked, or it is actively trying to
1456 * master this lock. */
1457 if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) {
1458 mlog(ML_ERROR, "lock with no owner should be "
1459 "in-progress!\n");
1460 BUG();
1461 }
1462
1463 // mlog(0, "lockres is in progress...\n");
1464 spin_lock(&dlm->master_lock);
1465 found = dlm_find_mle(dlm, &tmpmle, name, namelen);
1466 if (!found) {
1467 mlog(ML_ERROR, "no mle found for this lock!\n");
1468 BUG();
1469 }
1470 set_maybe = 1;
1471 spin_lock(&tmpmle->spinlock);
1472 if (tmpmle->type == DLM_MLE_BLOCK) {
1473 // mlog(0, "this node is waiting for "
1474 // "lockres to be mastered\n");
1475 response = DLM_MASTER_RESP_NO;
1476 } else if (tmpmle->type == DLM_MLE_MIGRATION) {
1477 mlog(0, "node %u is master, but trying to migrate to "
1478 "node %u.\n", tmpmle->master, tmpmle->new_master);
1479 if (tmpmle->master == dlm->node_num) {
1480 response = DLM_MASTER_RESP_YES;
1481 mlog(ML_ERROR, "no owner on lockres, but this "
1482 "node is trying to migrate it to %u?!\n",
1483 tmpmle->new_master);
1484 BUG();
1485 } else {
1486 /* the real master can respond on its own */
1487 response = DLM_MASTER_RESP_NO;
1488 }
1489 } else if (tmpmle->master != DLM_LOCK_RES_OWNER_UNKNOWN) {
1490 set_maybe = 0;
Kurt Hackel9c6510a2006-03-02 18:09:26 -08001491 if (tmpmle->master == dlm->node_num) {
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001492 response = DLM_MASTER_RESP_YES;
Kurt Hackel9c6510a2006-03-02 18:09:26 -08001493 /* this node will be the owner.
1494 * go back and clean the mles on any
1495 * other nodes */
1496 dispatch_assert = 1;
1497 } else
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001498 response = DLM_MASTER_RESP_NO;
1499 } else {
1500 // mlog(0, "this node is attempting to "
1501 // "master lockres\n");
1502 response = DLM_MASTER_RESP_MAYBE;
1503 }
1504 if (set_maybe)
1505 set_bit(request->node_idx, tmpmle->maybe_map);
1506 spin_unlock(&tmpmle->spinlock);
1507
1508 spin_unlock(&dlm->master_lock);
1509 spin_unlock(&res->spinlock);
1510
1511 /* keep the mle attached to heartbeat events */
1512 dlm_put_mle(tmpmle);
1513 if (mle)
1514 kmem_cache_free(dlm_mle_cache, mle);
1515 goto send_response;
1516 }
1517
1518 /*
1519 * lockres doesn't exist on this node
1520 * if there is an MLE_BLOCK, return NO
1521 * if there is an MLE_MASTER, return MAYBE
1522 * otherwise, add an MLE_BLOCK, return NO
1523 */
1524 spin_lock(&dlm->master_lock);
1525 found = dlm_find_mle(dlm, &tmpmle, name, namelen);
1526 if (!found) {
1527 /* this lockid has never been seen on this node yet */
1528 // mlog(0, "no mle found\n");
1529 if (!mle) {
1530 spin_unlock(&dlm->master_lock);
1531 spin_unlock(&dlm->spinlock);
1532
1533 mle = (struct dlm_master_list_entry *)
Kurt Hackelad8100e2006-05-01 14:25:21 -07001534 kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001535 if (!mle) {
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001536 response = DLM_MASTER_RESP_ERROR;
Kurt Hackel9c6510a2006-03-02 18:09:26 -08001537 mlog_errno(-ENOMEM);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001538 goto send_response;
1539 }
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001540 goto way_up_top;
1541 }
1542
1543 // mlog(0, "this is second time thru, already allocated, "
1544 // "add the block.\n");
Kurt Hackel41b8c8a2006-04-27 19:00:26 -07001545 dlm_init_mle(mle, DLM_MLE_BLOCK, dlm, NULL, name, namelen);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001546 set_bit(request->node_idx, mle->maybe_map);
1547 list_add(&mle->list, &dlm->master_list);
1548 response = DLM_MASTER_RESP_NO;
1549 } else {
1550 // mlog(0, "mle was found\n");
1551 set_maybe = 1;
1552 spin_lock(&tmpmle->spinlock);
Kurt Hackel9c6510a2006-03-02 18:09:26 -08001553 if (tmpmle->master == dlm->node_num) {
1554 mlog(ML_ERROR, "no lockres, but an mle with this node as master!\n");
1555 BUG();
1556 }
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001557 if (tmpmle->type == DLM_MLE_BLOCK)
1558 response = DLM_MASTER_RESP_NO;
1559 else if (tmpmle->type == DLM_MLE_MIGRATION) {
1560 mlog(0, "migration mle was found (%u->%u)\n",
1561 tmpmle->master, tmpmle->new_master);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001562 /* real master can respond on its own */
1563 response = DLM_MASTER_RESP_NO;
Kurt Hackel9c6510a2006-03-02 18:09:26 -08001564 } else
1565 response = DLM_MASTER_RESP_MAYBE;
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001566 if (set_maybe)
1567 set_bit(request->node_idx, tmpmle->maybe_map);
1568 spin_unlock(&tmpmle->spinlock);
1569 }
1570 spin_unlock(&dlm->master_lock);
1571 spin_unlock(&dlm->spinlock);
1572
1573 if (found) {
1574 /* keep the mle attached to heartbeat events */
1575 dlm_put_mle(tmpmle);
1576 }
1577send_response:
Kurt Hackel9c6510a2006-03-02 18:09:26 -08001578
1579 if (dispatch_assert) {
1580 if (response != DLM_MASTER_RESP_YES)
1581 mlog(ML_ERROR, "invalid response %d\n", response);
1582 if (!res) {
1583 mlog(ML_ERROR, "bad lockres while trying to assert!\n");
1584 BUG();
1585 }
1586 mlog(0, "%u is the owner of %.*s, cleaning everyone else\n",
1587 dlm->node_num, res->lockname.len, res->lockname.name);
1588 ret = dlm_dispatch_assert_master(dlm, res, 0, request->node_idx,
1589 DLM_ASSERT_MASTER_MLE_CLEANUP);
1590 if (ret < 0) {
1591 mlog(ML_ERROR, "failed to dispatch assert master work\n");
1592 response = DLM_MASTER_RESP_ERROR;
1593 }
1594 }
1595
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001596 dlm_put(dlm);
1597 return response;
1598}
1599
1600/*
1601 * DLM_ASSERT_MASTER_MSG
1602 */
1603
1604
1605/*
1606 * NOTE: this can be used for debugging
1607 * can periodically run all locks owned by this node
1608 * and re-assert across the cluster...
1609 */
1610static int dlm_do_assert_master(struct dlm_ctxt *dlm, const char *lockname,
1611 unsigned int namelen, void *nodemap,
1612 u32 flags)
1613{
1614 struct dlm_assert_master assert;
1615 int to, tmpret;
1616 struct dlm_node_iter iter;
1617 int ret = 0;
Kurt Hackel9c6510a2006-03-02 18:09:26 -08001618 int reassert;
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001619
1620 BUG_ON(namelen > O2NM_MAX_NAME_LEN);
Kurt Hackel9c6510a2006-03-02 18:09:26 -08001621again:
1622 reassert = 0;
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001623
1624 /* note that if this nodemap is empty, it returns 0 */
1625 dlm_node_iter_init(nodemap, &iter);
1626 while ((to = dlm_node_iter_next(&iter)) >= 0) {
1627 int r = 0;
Kurt Hackela9ee4c82006-04-27 19:26:15 -07001628 struct dlm_master_list_entry *mle = NULL;
1629
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001630 mlog(0, "sending assert master to %d (%.*s)\n", to,
1631 namelen, lockname);
1632 memset(&assert, 0, sizeof(assert));
1633 assert.node_idx = dlm->node_num;
1634 assert.namelen = namelen;
1635 memcpy(assert.name, lockname, namelen);
1636 assert.flags = cpu_to_be32(flags);
1637
1638 tmpret = o2net_send_message(DLM_ASSERT_MASTER_MSG, dlm->key,
1639 &assert, sizeof(assert), to, &r);
1640 if (tmpret < 0) {
Kurt Hackel3b3b84a2006-05-01 14:31:37 -07001641 mlog(0, "assert_master returned %d!\n", tmpret);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001642 if (!dlm_is_host_down(tmpret)) {
Kurt Hackel3b3b84a2006-05-01 14:31:37 -07001643 mlog(ML_ERROR, "unhandled error=%d!\n", tmpret);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001644 BUG();
1645 }
1646 /* a node died. finish out the rest of the nodes. */
Kurt Hackel3b3b84a2006-05-01 14:31:37 -07001647 mlog(0, "link to %d went down!\n", to);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001648 /* any nonzero status return will do */
1649 ret = tmpret;
1650 } else if (r < 0) {
1651 /* ok, something horribly messed. kill thyself. */
1652 mlog(ML_ERROR,"during assert master of %.*s to %u, "
1653 "got %d.\n", namelen, lockname, to, r);
Kurt Hackela9ee4c82006-04-27 19:26:15 -07001654 spin_lock(&dlm->spinlock);
1655 spin_lock(&dlm->master_lock);
1656 if (dlm_find_mle(dlm, &mle, (char *)lockname,
1657 namelen)) {
1658 dlm_print_one_mle(mle);
1659 __dlm_put_mle(mle);
1660 }
1661 spin_unlock(&dlm->master_lock);
1662 spin_unlock(&dlm->spinlock);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001663 BUG();
Kurt Hackel9c6510a2006-03-02 18:09:26 -08001664 } else if (r == EAGAIN) {
1665 mlog(0, "%.*s: node %u create mles on other "
1666 "nodes and requests a re-assert\n",
1667 namelen, lockname, to);
1668 reassert = 1;
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001669 }
1670 }
1671
Kurt Hackel9c6510a2006-03-02 18:09:26 -08001672 if (reassert)
1673 goto again;
1674
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001675 return ret;
1676}
1677
1678/*
1679 * locks that can be taken here:
1680 * dlm->spinlock
1681 * res->spinlock
1682 * mle->spinlock
1683 * dlm->master_list
1684 *
1685 * if possible, TRIM THIS DOWN!!!
1686 */
1687int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data)
1688{
1689 struct dlm_ctxt *dlm = data;
1690 struct dlm_master_list_entry *mle = NULL;
1691 struct dlm_assert_master *assert = (struct dlm_assert_master *)msg->buf;
1692 struct dlm_lock_resource *res = NULL;
1693 char *name;
Mark Fasheha3d33292006-03-09 17:55:56 -08001694 unsigned int namelen, hash;
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001695 u32 flags;
Kurt Hackel9c6510a2006-03-02 18:09:26 -08001696 int master_request = 0;
1697 int ret = 0;
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001698
1699 if (!dlm_grab(dlm))
1700 return 0;
1701
1702 name = assert->name;
1703 namelen = assert->namelen;
Mark Fasheha3d33292006-03-09 17:55:56 -08001704 hash = dlm_lockid_hash(name, namelen);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001705 flags = be32_to_cpu(assert->flags);
1706
1707 if (namelen > DLM_LOCKID_NAME_MAX) {
1708 mlog(ML_ERROR, "Invalid name length!");
1709 goto done;
1710 }
1711
1712 spin_lock(&dlm->spinlock);
1713
1714 if (flags)
1715 mlog(0, "assert_master with flags: %u\n", flags);
1716
1717 /* find the MLE */
1718 spin_lock(&dlm->master_lock);
1719 if (!dlm_find_mle(dlm, &mle, name, namelen)) {
1720 /* not an error, could be master just re-asserting */
1721 mlog(0, "just got an assert_master from %u, but no "
1722 "MLE for it! (%.*s)\n", assert->node_idx,
1723 namelen, name);
1724 } else {
1725 int bit = find_next_bit (mle->maybe_map, O2NM_MAX_NODES, 0);
1726 if (bit >= O2NM_MAX_NODES) {
1727 /* not necessarily an error, though less likely.
1728 * could be master just re-asserting. */
Kurt Hackelaa852352006-04-27 19:04:49 -07001729 mlog(0, "no bits set in the maybe_map, but %u "
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001730 "is asserting! (%.*s)\n", assert->node_idx,
1731 namelen, name);
1732 } else if (bit != assert->node_idx) {
1733 if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) {
1734 mlog(0, "master %u was found, %u should "
1735 "back off\n", assert->node_idx, bit);
1736 } else {
1737 /* with the fix for bug 569, a higher node
1738 * number winning the mastery will respond
1739 * YES to mastery requests, but this node
1740 * had no way of knowing. let it pass. */
Kurt Hackelaa852352006-04-27 19:04:49 -07001741 mlog(0, "%u is the lowest node, "
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001742 "%u is asserting. (%.*s) %u must "
1743 "have begun after %u won.\n", bit,
1744 assert->node_idx, namelen, name, bit,
1745 assert->node_idx);
1746 }
1747 }
Kurt Hackel2d1a8682006-04-27 19:01:35 -07001748 if (mle->type == DLM_MLE_MIGRATION) {
1749 if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) {
1750 mlog(0, "%s:%.*s: got cleanup assert"
1751 " from %u for migration\n",
1752 dlm->name, namelen, name,
1753 assert->node_idx);
1754 } else if (!(flags & DLM_ASSERT_MASTER_FINISH_MIGRATION)) {
1755 mlog(0, "%s:%.*s: got unrelated assert"
1756 " from %u for migration, ignoring\n",
1757 dlm->name, namelen, name,
1758 assert->node_idx);
1759 __dlm_put_mle(mle);
1760 spin_unlock(&dlm->master_lock);
1761 spin_unlock(&dlm->spinlock);
1762 goto done;
1763 }
1764 }
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001765 }
1766 spin_unlock(&dlm->master_lock);
1767
1768 /* ok everything checks out with the MLE
1769 * now check to see if there is a lockres */
Mark Fasheha3d33292006-03-09 17:55:56 -08001770 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001771 if (res) {
1772 spin_lock(&res->spinlock);
1773 if (res->state & DLM_LOCK_RES_RECOVERING) {
1774 mlog(ML_ERROR, "%u asserting but %.*s is "
1775 "RECOVERING!\n", assert->node_idx, namelen, name);
1776 goto kill;
1777 }
1778 if (!mle) {
Kurt Hackeldc2ed192006-04-27 19:03:18 -07001779 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN &&
1780 res->owner != assert->node_idx) {
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001781 mlog(ML_ERROR, "assert_master from "
1782 "%u, but current owner is "
1783 "%u! (%.*s)\n",
1784 assert->node_idx, res->owner,
1785 namelen, name);
1786 goto kill;
1787 }
1788 } else if (mle->type != DLM_MLE_MIGRATION) {
1789 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
1790 /* owner is just re-asserting */
1791 if (res->owner == assert->node_idx) {
1792 mlog(0, "owner %u re-asserting on "
1793 "lock %.*s\n", assert->node_idx,
1794 namelen, name);
1795 goto ok;
1796 }
1797 mlog(ML_ERROR, "got assert_master from "
1798 "node %u, but %u is the owner! "
1799 "(%.*s)\n", assert->node_idx,
1800 res->owner, namelen, name);
1801 goto kill;
1802 }
1803 if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) {
1804 mlog(ML_ERROR, "got assert from %u, but lock "
1805 "with no owner should be "
1806 "in-progress! (%.*s)\n",
1807 assert->node_idx,
1808 namelen, name);
1809 goto kill;
1810 }
1811 } else /* mle->type == DLM_MLE_MIGRATION */ {
1812 /* should only be getting an assert from new master */
1813 if (assert->node_idx != mle->new_master) {
1814 mlog(ML_ERROR, "got assert from %u, but "
1815 "new master is %u, and old master "
1816 "was %u (%.*s)\n",
1817 assert->node_idx, mle->new_master,
1818 mle->master, namelen, name);
1819 goto kill;
1820 }
1821
1822 }
1823ok:
1824 spin_unlock(&res->spinlock);
1825 }
1826 spin_unlock(&dlm->spinlock);
1827
1828 // mlog(0, "woo! got an assert_master from node %u!\n",
1829 // assert->node_idx);
1830 if (mle) {
Kurt Hackel9c6510a2006-03-02 18:09:26 -08001831 int extra_ref = 0;
1832 int nn = -1;
Kurt Hackela2bf0472006-04-27 18:51:26 -07001833 int rr, err = 0;
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001834
1835 spin_lock(&mle->spinlock);
Kurt Hackel9c6510a2006-03-02 18:09:26 -08001836 if (mle->type == DLM_MLE_BLOCK || mle->type == DLM_MLE_MIGRATION)
1837 extra_ref = 1;
1838 else {
1839 /* MASTER mle: if any bits set in the response map
1840 * then the calling node needs to re-assert to clear
1841 * up nodes that this node contacted */
1842 while ((nn = find_next_bit (mle->response_map, O2NM_MAX_NODES,
1843 nn+1)) < O2NM_MAX_NODES) {
1844 if (nn != dlm->node_num && nn != assert->node_idx)
1845 master_request = 1;
1846 }
1847 }
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001848 mle->master = assert->node_idx;
1849 atomic_set(&mle->woken, 1);
1850 wake_up(&mle->wq);
1851 spin_unlock(&mle->spinlock);
1852
Kurt Hackela2bf0472006-04-27 18:51:26 -07001853 if (res) {
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001854 spin_lock(&res->spinlock);
Kurt Hackela2bf0472006-04-27 18:51:26 -07001855 if (mle->type == DLM_MLE_MIGRATION) {
1856 mlog(0, "finishing off migration of lockres %.*s, "
1857 "from %u to %u\n",
1858 res->lockname.len, res->lockname.name,
1859 dlm->node_num, mle->new_master);
1860 res->state &= ~DLM_LOCK_RES_MIGRATING;
1861 dlm_change_lockres_owner(dlm, res, mle->new_master);
1862 BUG_ON(res->state & DLM_LOCK_RES_DIRTY);
1863 } else {
1864 dlm_change_lockres_owner(dlm, res, mle->master);
1865 }
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001866 spin_unlock(&res->spinlock);
1867 }
Kurt Hackela2bf0472006-04-27 18:51:26 -07001868
1869 /* master is known, detach if not already detached.
1870 * ensures that only one assert_master call will happen
1871 * on this mle. */
1872 spin_lock(&dlm->spinlock);
1873 spin_lock(&dlm->master_lock);
1874
1875 rr = atomic_read(&mle->mle_refs.refcount);
1876 if (mle->inuse > 0) {
1877 if (extra_ref && rr < 3)
1878 err = 1;
1879 else if (!extra_ref && rr < 2)
1880 err = 1;
1881 } else {
1882 if (extra_ref && rr < 2)
1883 err = 1;
1884 else if (!extra_ref && rr < 1)
1885 err = 1;
1886 }
1887 if (err) {
1888 mlog(ML_ERROR, "%s:%.*s: got assert master from %u "
1889 "that will mess up this node, refs=%d, extra=%d, "
1890 "inuse=%d\n", dlm->name, namelen, name,
1891 assert->node_idx, rr, extra_ref, mle->inuse);
1892 dlm_print_one_mle(mle);
1893 }
1894 list_del_init(&mle->list);
1895 __dlm_mle_detach_hb_events(dlm, mle);
1896 __dlm_put_mle(mle);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001897 if (extra_ref) {
1898 /* the assert master message now balances the extra
1899 * ref given by the master / migration request message.
1900 * if this is the last put, it will be removed
1901 * from the list. */
Kurt Hackela2bf0472006-04-27 18:51:26 -07001902 __dlm_put_mle(mle);
1903 }
1904 spin_unlock(&dlm->master_lock);
1905 spin_unlock(&dlm->spinlock);
1906 } else if (res) {
1907 if (res->owner != assert->node_idx) {
1908 mlog(0, "assert_master from %u, but current "
1909 "owner is %u (%.*s), no mle\n", assert->node_idx,
1910 res->owner, namelen, name);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001911 }
1912 }
1913
1914done:
Kurt Hackel9c6510a2006-03-02 18:09:26 -08001915 ret = 0;
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001916 if (res)
1917 dlm_lockres_put(res);
1918 dlm_put(dlm);
Kurt Hackel9c6510a2006-03-02 18:09:26 -08001919 if (master_request) {
1920 mlog(0, "need to tell master to reassert\n");
1921 ret = EAGAIN; // positive. negative would shoot down the node.
1922 }
1923 return ret;
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001924
1925kill:
1926 /* kill the caller! */
Kurt Hackela9ee4c82006-04-27 19:26:15 -07001927 mlog(ML_ERROR, "Bad message received from another node. Dumping state "
1928 "and killing the other node now! This node is OK and can continue.\n");
1929 __dlm_print_one_lock_resource(res);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001930 spin_unlock(&res->spinlock);
1931 spin_unlock(&dlm->spinlock);
1932 dlm_lockres_put(res);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001933 dlm_put(dlm);
1934 return -EINVAL;
1935}
1936
1937int dlm_dispatch_assert_master(struct dlm_ctxt *dlm,
1938 struct dlm_lock_resource *res,
1939 int ignore_higher, u8 request_from, u32 flags)
1940{
1941 struct dlm_work_item *item;
Kurt Hackelad8100e2006-05-01 14:25:21 -07001942 item = kcalloc(1, sizeof(*item), GFP_NOFS);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001943 if (!item)
1944 return -ENOMEM;
1945
1946
1947 /* queue up work for dlm_assert_master_worker */
1948 dlm_grab(dlm); /* get an extra ref for the work item */
1949 dlm_init_work_item(dlm, item, dlm_assert_master_worker, NULL);
1950 item->u.am.lockres = res; /* already have a ref */
1951 /* can optionally ignore node numbers higher than this node */
1952 item->u.am.ignore_higher = ignore_higher;
1953 item->u.am.request_from = request_from;
1954 item->u.am.flags = flags;
1955
Kurt Hackel9c6510a2006-03-02 18:09:26 -08001956 if (ignore_higher)
1957 mlog(0, "IGNORE HIGHER: %.*s\n", res->lockname.len,
1958 res->lockname.name);
1959
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001960 spin_lock(&dlm->work_lock);
1961 list_add_tail(&item->list, &dlm->work_list);
1962 spin_unlock(&dlm->work_lock);
1963
Kurt Hackel3156d262006-05-01 14:39:29 -07001964 queue_work(dlm->dlm_worker, &dlm->dispatched_work);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08001965 return 0;
1966}
1967
1968static void dlm_assert_master_worker(struct dlm_work_item *item, void *data)
1969{
1970 struct dlm_ctxt *dlm = data;
1971 int ret = 0;
1972 struct dlm_lock_resource *res;
1973 unsigned long nodemap[BITS_TO_LONGS(O2NM_MAX_NODES)];
1974 int ignore_higher;
1975 int bit;
1976 u8 request_from;
1977 u32 flags;
1978
1979 dlm = item->dlm;
1980 res = item->u.am.lockres;
1981 ignore_higher = item->u.am.ignore_higher;
1982 request_from = item->u.am.request_from;
1983 flags = item->u.am.flags;
1984
1985 spin_lock(&dlm->spinlock);
1986 memcpy(nodemap, dlm->domain_map, sizeof(nodemap));
1987 spin_unlock(&dlm->spinlock);
1988
1989 clear_bit(dlm->node_num, nodemap);
1990 if (ignore_higher) {
1991 /* if is this just to clear up mles for nodes below
1992 * this node, do not send the message to the original
1993 * caller or any node number higher than this */
1994 clear_bit(request_from, nodemap);
1995 bit = dlm->node_num;
1996 while (1) {
1997 bit = find_next_bit(nodemap, O2NM_MAX_NODES,
1998 bit+1);
1999 if (bit >= O2NM_MAX_NODES)
2000 break;
2001 clear_bit(bit, nodemap);
2002 }
2003 }
2004
Kurt Hackel36407482006-05-01 13:32:27 -07002005 /*
2006 * If we're migrating this lock to someone else, we are no
2007 * longer allowed to assert out own mastery. OTOH, we need to
2008 * prevent migration from starting while we're still asserting
2009 * our dominance. The reserved ast delays migration.
2010 */
2011 spin_lock(&res->spinlock);
2012 if (res->state & DLM_LOCK_RES_MIGRATING) {
2013 mlog(0, "Someone asked us to assert mastery, but we're "
2014 "in the middle of migration. Skipping assert, "
2015 "the new master will handle that.\n");
2016 spin_unlock(&res->spinlock);
2017 goto put;
2018 } else
2019 __dlm_lockres_reserve_ast(res);
2020 spin_unlock(&res->spinlock);
2021
Kurt Hackel6714d8e2005-12-15 14:31:23 -08002022 /* this call now finishes out the nodemap
2023 * even if one or more nodes die */
2024 mlog(0, "worker about to master %.*s here, this=%u\n",
2025 res->lockname.len, res->lockname.name, dlm->node_num);
2026 ret = dlm_do_assert_master(dlm, res->lockname.name,
2027 res->lockname.len,
2028 nodemap, flags);
2029 if (ret < 0) {
2030 /* no need to restart, we are done */
Kurt Hackel3b3b84a2006-05-01 14:31:37 -07002031 if (!dlm_is_host_down(ret))
2032 mlog_errno(ret);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08002033 }
2034
Kurt Hackel36407482006-05-01 13:32:27 -07002035 /* Ok, we've asserted ourselves. Let's let migration start. */
2036 dlm_lockres_release_ast(dlm, res);
2037
2038put:
Kurt Hackel6714d8e2005-12-15 14:31:23 -08002039 dlm_lockres_put(res);
2040
2041 mlog(0, "finished with dlm_assert_master_worker\n");
2042}
2043
Kurt Hackelc03872f2006-03-06 14:08:49 -08002044/* SPECIAL CASE for the $RECOVERY lock used by the recovery thread.
2045 * We cannot wait for node recovery to complete to begin mastering this
2046 * lockres because this lockres is used to kick off recovery! ;-)
2047 * So, do a pre-check on all living nodes to see if any of those nodes
2048 * think that $RECOVERY is currently mastered by a dead node. If so,
2049 * we wait a short time to allow that node to get notified by its own
2050 * heartbeat stack, then check again. All $RECOVERY lock resources
2051 * mastered by dead nodes are purged when the hearbeat callback is
2052 * fired, so we can know for sure that it is safe to continue once
2053 * the node returns a live node or no node. */
2054static int dlm_pre_master_reco_lockres(struct dlm_ctxt *dlm,
2055 struct dlm_lock_resource *res)
2056{
2057 struct dlm_node_iter iter;
2058 int nodenum;
2059 int ret = 0;
2060 u8 master = DLM_LOCK_RES_OWNER_UNKNOWN;
2061
2062 spin_lock(&dlm->spinlock);
2063 dlm_node_iter_init(dlm->domain_map, &iter);
2064 spin_unlock(&dlm->spinlock);
2065
2066 while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2067 /* do not send to self */
2068 if (nodenum == dlm->node_num)
2069 continue;
2070 ret = dlm_do_master_requery(dlm, res, nodenum, &master);
2071 if (ret < 0) {
2072 mlog_errno(ret);
2073 if (!dlm_is_host_down(ret))
2074 BUG();
2075 /* host is down, so answer for that node would be
2076 * DLM_LOCK_RES_OWNER_UNKNOWN. continue. */
Kurt Hackelf42a1002006-05-01 11:53:33 -07002077 ret = 0;
Kurt Hackelc03872f2006-03-06 14:08:49 -08002078 }
2079
2080 if (master != DLM_LOCK_RES_OWNER_UNKNOWN) {
2081 /* check to see if this master is in the recovery map */
2082 spin_lock(&dlm->spinlock);
2083 if (test_bit(master, dlm->recovery_map)) {
2084 mlog(ML_NOTICE, "%s: node %u has not seen "
2085 "node %u go down yet, and thinks the "
2086 "dead node is mastering the recovery "
2087 "lock. must wait.\n", dlm->name,
2088 nodenum, master);
2089 ret = -EAGAIN;
2090 }
2091 spin_unlock(&dlm->spinlock);
2092 mlog(0, "%s: reco lock master is %u\n", dlm->name,
2093 master);
2094 break;
2095 }
2096 }
2097 return ret;
2098}
2099
Kurt Hackel6714d8e2005-12-15 14:31:23 -08002100
2101/*
2102 * DLM_MIGRATE_LOCKRES
2103 */
2104
2105
2106int dlm_migrate_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
2107 u8 target)
2108{
2109 struct dlm_master_list_entry *mle = NULL;
2110 struct dlm_master_list_entry *oldmle = NULL;
2111 struct dlm_migratable_lockres *mres = NULL;
2112 int ret = -EINVAL;
2113 const char *name;
2114 unsigned int namelen;
2115 int mle_added = 0;
2116 struct list_head *queue, *iter;
2117 int i;
2118 struct dlm_lock *lock;
2119 int empty = 1;
2120
2121 if (!dlm_grab(dlm))
2122 return -EINVAL;
2123
2124 name = res->lockname.name;
2125 namelen = res->lockname.len;
2126
2127 mlog(0, "migrating %.*s to %u\n", namelen, name, target);
2128
2129 /*
2130 * ensure this lockres is a proper candidate for migration
2131 */
2132 spin_lock(&res->spinlock);
2133 if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
2134 mlog(0, "cannot migrate lockres with unknown owner!\n");
2135 spin_unlock(&res->spinlock);
2136 goto leave;
2137 }
2138 if (res->owner != dlm->node_num) {
2139 mlog(0, "cannot migrate lockres this node doesn't own!\n");
2140 spin_unlock(&res->spinlock);
2141 goto leave;
2142 }
2143 mlog(0, "checking queues...\n");
2144 queue = &res->granted;
2145 for (i=0; i<3; i++) {
2146 list_for_each(iter, queue) {
2147 lock = list_entry (iter, struct dlm_lock, list);
2148 empty = 0;
2149 if (lock->ml.node == dlm->node_num) {
2150 mlog(0, "found a lock owned by this node "
2151 "still on the %s queue! will not "
2152 "migrate this lockres\n",
2153 i==0 ? "granted" :
2154 (i==1 ? "converting" : "blocked"));
2155 spin_unlock(&res->spinlock);
2156 ret = -ENOTEMPTY;
2157 goto leave;
2158 }
2159 }
2160 queue++;
2161 }
2162 mlog(0, "all locks on this lockres are nonlocal. continuing\n");
2163 spin_unlock(&res->spinlock);
2164
2165 /* no work to do */
2166 if (empty) {
2167 mlog(0, "no locks were found on this lockres! done!\n");
2168 ret = 0;
2169 goto leave;
2170 }
2171
2172 /*
2173 * preallocate up front
2174 * if this fails, abort
2175 */
2176
2177 ret = -ENOMEM;
Kurt Hackelad8100e2006-05-01 14:25:21 -07002178 mres = (struct dlm_migratable_lockres *) __get_free_page(GFP_NOFS);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08002179 if (!mres) {
2180 mlog_errno(ret);
2181 goto leave;
2182 }
2183
2184 mle = (struct dlm_master_list_entry *) kmem_cache_alloc(dlm_mle_cache,
Kurt Hackelad8100e2006-05-01 14:25:21 -07002185 GFP_NOFS);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08002186 if (!mle) {
2187 mlog_errno(ret);
2188 goto leave;
2189 }
2190 ret = 0;
2191
2192 /*
2193 * find a node to migrate the lockres to
2194 */
2195
2196 mlog(0, "picking a migration node\n");
2197 spin_lock(&dlm->spinlock);
2198 /* pick a new node */
2199 if (!test_bit(target, dlm->domain_map) ||
2200 target >= O2NM_MAX_NODES) {
2201 target = dlm_pick_migration_target(dlm, res);
2202 }
2203 mlog(0, "node %u chosen for migration\n", target);
2204
2205 if (target >= O2NM_MAX_NODES ||
2206 !test_bit(target, dlm->domain_map)) {
2207 /* target chosen is not alive */
2208 ret = -EINVAL;
2209 }
2210
2211 if (ret) {
2212 spin_unlock(&dlm->spinlock);
2213 goto fail;
2214 }
2215
2216 mlog(0, "continuing with target = %u\n", target);
2217
2218 /*
2219 * clear any existing master requests and
2220 * add the migration mle to the list
2221 */
2222 spin_lock(&dlm->master_lock);
2223 ret = dlm_add_migration_mle(dlm, res, mle, &oldmle, name,
2224 namelen, target, dlm->node_num);
2225 spin_unlock(&dlm->master_lock);
2226 spin_unlock(&dlm->spinlock);
2227
2228 if (ret == -EEXIST) {
2229 mlog(0, "another process is already migrating it\n");
2230 goto fail;
2231 }
2232 mle_added = 1;
2233
2234 /*
2235 * set the MIGRATING flag and flush asts
2236 * if we fail after this we need to re-dirty the lockres
2237 */
2238 if (dlm_mark_lockres_migrating(dlm, res, target) < 0) {
2239 mlog(ML_ERROR, "tried to migrate %.*s to %u, but "
2240 "the target went down.\n", res->lockname.len,
2241 res->lockname.name, target);
2242 spin_lock(&res->spinlock);
2243 res->state &= ~DLM_LOCK_RES_MIGRATING;
2244 spin_unlock(&res->spinlock);
2245 ret = -EINVAL;
2246 }
2247
2248fail:
2249 if (oldmle) {
2250 /* master is known, detach if not already detached */
2251 dlm_mle_detach_hb_events(dlm, oldmle);
2252 dlm_put_mle(oldmle);
2253 }
2254
2255 if (ret < 0) {
2256 if (mle_added) {
2257 dlm_mle_detach_hb_events(dlm, mle);
2258 dlm_put_mle(mle);
2259 } else if (mle) {
2260 kmem_cache_free(dlm_mle_cache, mle);
2261 }
2262 goto leave;
2263 }
2264
2265 /*
2266 * at this point, we have a migration target, an mle
2267 * in the master list, and the MIGRATING flag set on
2268 * the lockres
2269 */
2270
2271
2272 /* get an extra reference on the mle.
2273 * otherwise the assert_master from the new
2274 * master will destroy this.
2275 * also, make sure that all callers of dlm_get_mle
2276 * take both dlm->spinlock and dlm->master_lock */
2277 spin_lock(&dlm->spinlock);
2278 spin_lock(&dlm->master_lock);
Kurt Hackela2bf0472006-04-27 18:51:26 -07002279 dlm_get_mle_inuse(mle);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08002280 spin_unlock(&dlm->master_lock);
2281 spin_unlock(&dlm->spinlock);
2282
2283 /* notify new node and send all lock state */
2284 /* call send_one_lockres with migration flag.
2285 * this serves as notice to the target node that a
2286 * migration is starting. */
2287 ret = dlm_send_one_lockres(dlm, res, mres, target,
2288 DLM_MRES_MIGRATION);
2289
2290 if (ret < 0) {
2291 mlog(0, "migration to node %u failed with %d\n",
2292 target, ret);
2293 /* migration failed, detach and clean up mle */
2294 dlm_mle_detach_hb_events(dlm, mle);
2295 dlm_put_mle(mle);
Kurt Hackela2bf0472006-04-27 18:51:26 -07002296 dlm_put_mle_inuse(mle);
2297 spin_lock(&res->spinlock);
2298 res->state &= ~DLM_LOCK_RES_MIGRATING;
2299 spin_unlock(&res->spinlock);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08002300 goto leave;
2301 }
2302
2303 /* at this point, the target sends a message to all nodes,
2304 * (using dlm_do_migrate_request). this node is skipped since
2305 * we had to put an mle in the list to begin the process. this
2306 * node now waits for target to do an assert master. this node
2307 * will be the last one notified, ensuring that the migration
2308 * is complete everywhere. if the target dies while this is
2309 * going on, some nodes could potentially see the target as the
2310 * master, so it is important that my recovery finds the migration
2311 * mle and sets the master to UNKNONWN. */
2312
2313
2314 /* wait for new node to assert master */
2315 while (1) {
2316 ret = wait_event_interruptible_timeout(mle->wq,
2317 (atomic_read(&mle->woken) == 1),
2318 msecs_to_jiffies(5000));
2319
2320 if (ret >= 0) {
2321 if (atomic_read(&mle->woken) == 1 ||
2322 res->owner == target)
2323 break;
2324
2325 mlog(0, "timed out during migration\n");
Kurt Hackele2faea42006-01-12 14:24:55 -08002326 /* avoid hang during shutdown when migrating lockres
2327 * to a node which also goes down */
2328 if (dlm_is_node_dead(dlm, target)) {
Kurt Hackelaa852352006-04-27 19:04:49 -07002329 mlog(0, "%s:%.*s: expected migration "
2330 "target %u is no longer up, restarting\n",
Kurt Hackele2faea42006-01-12 14:24:55 -08002331 dlm->name, res->lockname.len,
2332 res->lockname.name, target);
2333 ret = -ERESTARTSYS;
2334 }
Kurt Hackel6714d8e2005-12-15 14:31:23 -08002335 }
2336 if (ret == -ERESTARTSYS) {
2337 /* migration failed, detach and clean up mle */
2338 dlm_mle_detach_hb_events(dlm, mle);
2339 dlm_put_mle(mle);
Kurt Hackela2bf0472006-04-27 18:51:26 -07002340 dlm_put_mle_inuse(mle);
2341 spin_lock(&res->spinlock);
2342 res->state &= ~DLM_LOCK_RES_MIGRATING;
2343 spin_unlock(&res->spinlock);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08002344 goto leave;
2345 }
2346 /* TODO: if node died: stop, clean up, return error */
2347 }
2348
2349 /* all done, set the owner, clear the flag */
2350 spin_lock(&res->spinlock);
2351 dlm_set_lockres_owner(dlm, res, target);
2352 res->state &= ~DLM_LOCK_RES_MIGRATING;
2353 dlm_remove_nonlocal_locks(dlm, res);
2354 spin_unlock(&res->spinlock);
2355 wake_up(&res->wq);
2356
2357 /* master is known, detach if not already detached */
2358 dlm_mle_detach_hb_events(dlm, mle);
Kurt Hackela2bf0472006-04-27 18:51:26 -07002359 dlm_put_mle_inuse(mle);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08002360 ret = 0;
2361
2362 dlm_lockres_calc_usage(dlm, res);
2363
2364leave:
2365 /* re-dirty the lockres if we failed */
2366 if (ret < 0)
2367 dlm_kick_thread(dlm, res);
2368
2369 /* TODO: cleanup */
2370 if (mres)
2371 free_page((unsigned long)mres);
2372
2373 dlm_put(dlm);
2374
2375 mlog(0, "returning %d\n", ret);
2376 return ret;
2377}
Kurt Hackel6714d8e2005-12-15 14:31:23 -08002378
2379int dlm_lock_basts_flushed(struct dlm_ctxt *dlm, struct dlm_lock *lock)
2380{
2381 int ret;
2382 spin_lock(&dlm->ast_lock);
2383 spin_lock(&lock->spinlock);
2384 ret = (list_empty(&lock->bast_list) && !lock->bast_pending);
2385 spin_unlock(&lock->spinlock);
2386 spin_unlock(&dlm->ast_lock);
2387 return ret;
2388}
2389
2390static int dlm_migration_can_proceed(struct dlm_ctxt *dlm,
2391 struct dlm_lock_resource *res,
2392 u8 mig_target)
2393{
2394 int can_proceed;
2395 spin_lock(&res->spinlock);
2396 can_proceed = !!(res->state & DLM_LOCK_RES_MIGRATING);
2397 spin_unlock(&res->spinlock);
2398
2399 /* target has died, so make the caller break out of the
2400 * wait_event, but caller must recheck the domain_map */
2401 spin_lock(&dlm->spinlock);
2402 if (!test_bit(mig_target, dlm->domain_map))
2403 can_proceed = 1;
2404 spin_unlock(&dlm->spinlock);
2405 return can_proceed;
2406}
2407
2408int dlm_lockres_is_dirty(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
2409{
2410 int ret;
2411 spin_lock(&res->spinlock);
2412 ret = !!(res->state & DLM_LOCK_RES_DIRTY);
2413 spin_unlock(&res->spinlock);
2414 return ret;
2415}
2416
2417
2418static int dlm_mark_lockres_migrating(struct dlm_ctxt *dlm,
2419 struct dlm_lock_resource *res,
2420 u8 target)
2421{
2422 int ret = 0;
2423
2424 mlog(0, "dlm_mark_lockres_migrating: %.*s, from %u to %u\n",
2425 res->lockname.len, res->lockname.name, dlm->node_num,
2426 target);
2427 /* need to set MIGRATING flag on lockres. this is done by
2428 * ensuring that all asts have been flushed for this lockres. */
2429 spin_lock(&res->spinlock);
2430 BUG_ON(res->migration_pending);
2431 res->migration_pending = 1;
2432 /* strategy is to reserve an extra ast then release
2433 * it below, letting the release do all of the work */
2434 __dlm_lockres_reserve_ast(res);
2435 spin_unlock(&res->spinlock);
2436
2437 /* now flush all the pending asts.. hang out for a bit */
2438 dlm_kick_thread(dlm, res);
2439 wait_event(dlm->ast_wq, !dlm_lockres_is_dirty(dlm, res));
2440 dlm_lockres_release_ast(dlm, res);
2441
2442 mlog(0, "about to wait on migration_wq, dirty=%s\n",
2443 res->state & DLM_LOCK_RES_DIRTY ? "yes" : "no");
2444 /* if the extra ref we just put was the final one, this
2445 * will pass thru immediately. otherwise, we need to wait
2446 * for the last ast to finish. */
2447again:
2448 ret = wait_event_interruptible_timeout(dlm->migration_wq,
2449 dlm_migration_can_proceed(dlm, res, target),
2450 msecs_to_jiffies(1000));
2451 if (ret < 0) {
2452 mlog(0, "woken again: migrating? %s, dead? %s\n",
2453 res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no",
2454 test_bit(target, dlm->domain_map) ? "no":"yes");
2455 } else {
2456 mlog(0, "all is well: migrating? %s, dead? %s\n",
2457 res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no",
2458 test_bit(target, dlm->domain_map) ? "no":"yes");
2459 }
2460 if (!dlm_migration_can_proceed(dlm, res, target)) {
2461 mlog(0, "trying again...\n");
2462 goto again;
2463 }
2464
2465 /* did the target go down or die? */
2466 spin_lock(&dlm->spinlock);
2467 if (!test_bit(target, dlm->domain_map)) {
2468 mlog(ML_ERROR, "aha. migration target %u just went down\n",
2469 target);
2470 ret = -EHOSTDOWN;
2471 }
2472 spin_unlock(&dlm->spinlock);
2473
2474 /*
2475 * at this point:
2476 *
2477 * o the DLM_LOCK_RES_MIGRATING flag is set
2478 * o there are no pending asts on this lockres
2479 * o all processes trying to reserve an ast on this
2480 * lockres must wait for the MIGRATING flag to clear
2481 */
2482 return ret;
2483}
2484
2485/* last step in the migration process.
2486 * original master calls this to free all of the dlm_lock
2487 * structures that used to be for other nodes. */
2488static void dlm_remove_nonlocal_locks(struct dlm_ctxt *dlm,
2489 struct dlm_lock_resource *res)
2490{
2491 struct list_head *iter, *iter2;
2492 struct list_head *queue = &res->granted;
2493 int i;
2494 struct dlm_lock *lock;
2495
2496 assert_spin_locked(&res->spinlock);
2497
2498 BUG_ON(res->owner == dlm->node_num);
2499
2500 for (i=0; i<3; i++) {
2501 list_for_each_safe(iter, iter2, queue) {
2502 lock = list_entry (iter, struct dlm_lock, list);
2503 if (lock->ml.node != dlm->node_num) {
2504 mlog(0, "putting lock for node %u\n",
2505 lock->ml.node);
2506 /* be extra careful */
2507 BUG_ON(!list_empty(&lock->ast_list));
2508 BUG_ON(!list_empty(&lock->bast_list));
2509 BUG_ON(lock->ast_pending);
2510 BUG_ON(lock->bast_pending);
2511 list_del_init(&lock->list);
2512 dlm_lock_put(lock);
2513 }
2514 }
2515 queue++;
2516 }
2517}
2518
2519/* for now this is not too intelligent. we will
2520 * need stats to make this do the right thing.
2521 * this just finds the first lock on one of the
2522 * queues and uses that node as the target. */
2523static u8 dlm_pick_migration_target(struct dlm_ctxt *dlm,
2524 struct dlm_lock_resource *res)
2525{
2526 int i;
2527 struct list_head *queue = &res->granted;
2528 struct list_head *iter;
2529 struct dlm_lock *lock;
2530 int nodenum;
2531
2532 assert_spin_locked(&dlm->spinlock);
2533
2534 spin_lock(&res->spinlock);
2535 for (i=0; i<3; i++) {
2536 list_for_each(iter, queue) {
2537 /* up to the caller to make sure this node
2538 * is alive */
2539 lock = list_entry (iter, struct dlm_lock, list);
2540 if (lock->ml.node != dlm->node_num) {
2541 spin_unlock(&res->spinlock);
2542 return lock->ml.node;
2543 }
2544 }
2545 queue++;
2546 }
2547 spin_unlock(&res->spinlock);
2548 mlog(0, "have not found a suitable target yet! checking domain map\n");
2549
2550 /* ok now we're getting desperate. pick anyone alive. */
2551 nodenum = -1;
2552 while (1) {
2553 nodenum = find_next_bit(dlm->domain_map,
2554 O2NM_MAX_NODES, nodenum+1);
2555 mlog(0, "found %d in domain map\n", nodenum);
2556 if (nodenum >= O2NM_MAX_NODES)
2557 break;
2558 if (nodenum != dlm->node_num) {
2559 mlog(0, "picking %d\n", nodenum);
2560 return nodenum;
2561 }
2562 }
2563
2564 mlog(0, "giving up. no master to migrate to\n");
2565 return DLM_LOCK_RES_OWNER_UNKNOWN;
2566}
2567
2568
2569
2570/* this is called by the new master once all lockres
2571 * data has been received */
2572static int dlm_do_migrate_request(struct dlm_ctxt *dlm,
2573 struct dlm_lock_resource *res,
2574 u8 master, u8 new_master,
2575 struct dlm_node_iter *iter)
2576{
2577 struct dlm_migrate_request migrate;
2578 int ret, status = 0;
2579 int nodenum;
2580
2581 memset(&migrate, 0, sizeof(migrate));
2582 migrate.namelen = res->lockname.len;
2583 memcpy(migrate.name, res->lockname.name, migrate.namelen);
2584 migrate.new_master = new_master;
2585 migrate.master = master;
2586
2587 ret = 0;
2588
2589 /* send message to all nodes, except the master and myself */
2590 while ((nodenum = dlm_node_iter_next(iter)) >= 0) {
2591 if (nodenum == master ||
2592 nodenum == new_master)
2593 continue;
2594
2595 ret = o2net_send_message(DLM_MIGRATE_REQUEST_MSG, dlm->key,
2596 &migrate, sizeof(migrate), nodenum,
2597 &status);
2598 if (ret < 0)
2599 mlog_errno(ret);
2600 else if (status < 0) {
2601 mlog(0, "migrate request (node %u) returned %d!\n",
2602 nodenum, status);
2603 ret = status;
2604 }
2605 }
2606
2607 if (ret < 0)
2608 mlog_errno(ret);
2609
2610 mlog(0, "returning ret=%d\n", ret);
2611 return ret;
2612}
2613
2614
2615/* if there is an existing mle for this lockres, we now know who the master is.
2616 * (the one who sent us *this* message) we can clear it up right away.
2617 * since the process that put the mle on the list still has a reference to it,
2618 * we can unhash it now, set the master and wake the process. as a result,
2619 * we will have no mle in the list to start with. now we can add an mle for
2620 * the migration and this should be the only one found for those scanning the
2621 * list. */
2622int dlm_migrate_request_handler(struct o2net_msg *msg, u32 len, void *data)
2623{
2624 struct dlm_ctxt *dlm = data;
2625 struct dlm_lock_resource *res = NULL;
2626 struct dlm_migrate_request *migrate = (struct dlm_migrate_request *) msg->buf;
2627 struct dlm_master_list_entry *mle = NULL, *oldmle = NULL;
2628 const char *name;
Mark Fasheha3d33292006-03-09 17:55:56 -08002629 unsigned int namelen, hash;
Kurt Hackel6714d8e2005-12-15 14:31:23 -08002630 int ret = 0;
2631
2632 if (!dlm_grab(dlm))
2633 return -EINVAL;
2634
2635 name = migrate->name;
2636 namelen = migrate->namelen;
Mark Fasheha3d33292006-03-09 17:55:56 -08002637 hash = dlm_lockid_hash(name, namelen);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08002638
2639 /* preallocate.. if this fails, abort */
2640 mle = (struct dlm_master_list_entry *) kmem_cache_alloc(dlm_mle_cache,
Kurt Hackelad8100e2006-05-01 14:25:21 -07002641 GFP_NOFS);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08002642
2643 if (!mle) {
2644 ret = -ENOMEM;
2645 goto leave;
2646 }
2647
2648 /* check for pre-existing lock */
2649 spin_lock(&dlm->spinlock);
Mark Fasheha3d33292006-03-09 17:55:56 -08002650 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08002651 spin_lock(&dlm->master_lock);
2652
2653 if (res) {
2654 spin_lock(&res->spinlock);
2655 if (res->state & DLM_LOCK_RES_RECOVERING) {
2656 /* if all is working ok, this can only mean that we got
2657 * a migrate request from a node that we now see as
2658 * dead. what can we do here? drop it to the floor? */
2659 spin_unlock(&res->spinlock);
2660 mlog(ML_ERROR, "Got a migrate request, but the "
2661 "lockres is marked as recovering!");
2662 kmem_cache_free(dlm_mle_cache, mle);
2663 ret = -EINVAL; /* need a better solution */
2664 goto unlock;
2665 }
2666 res->state |= DLM_LOCK_RES_MIGRATING;
2667 spin_unlock(&res->spinlock);
2668 }
2669
2670 /* ignore status. only nonzero status would BUG. */
2671 ret = dlm_add_migration_mle(dlm, res, mle, &oldmle,
2672 name, namelen,
2673 migrate->new_master,
2674 migrate->master);
2675
2676unlock:
2677 spin_unlock(&dlm->master_lock);
2678 spin_unlock(&dlm->spinlock);
2679
2680 if (oldmle) {
2681 /* master is known, detach if not already detached */
2682 dlm_mle_detach_hb_events(dlm, oldmle);
2683 dlm_put_mle(oldmle);
2684 }
2685
2686 if (res)
2687 dlm_lockres_put(res);
2688leave:
2689 dlm_put(dlm);
2690 return ret;
2691}
2692
2693/* must be holding dlm->spinlock and dlm->master_lock
2694 * when adding a migration mle, we can clear any other mles
2695 * in the master list because we know with certainty that
2696 * the master is "master". so we remove any old mle from
2697 * the list after setting it's master field, and then add
2698 * the new migration mle. this way we can hold with the rule
2699 * of having only one mle for a given lock name at all times. */
2700static int dlm_add_migration_mle(struct dlm_ctxt *dlm,
2701 struct dlm_lock_resource *res,
2702 struct dlm_master_list_entry *mle,
2703 struct dlm_master_list_entry **oldmle,
2704 const char *name, unsigned int namelen,
2705 u8 new_master, u8 master)
2706{
2707 int found;
2708 int ret = 0;
2709
2710 *oldmle = NULL;
2711
2712 mlog_entry_void();
2713
2714 assert_spin_locked(&dlm->spinlock);
2715 assert_spin_locked(&dlm->master_lock);
2716
2717 /* caller is responsible for any ref taken here on oldmle */
2718 found = dlm_find_mle(dlm, oldmle, (char *)name, namelen);
2719 if (found) {
2720 struct dlm_master_list_entry *tmp = *oldmle;
2721 spin_lock(&tmp->spinlock);
2722 if (tmp->type == DLM_MLE_MIGRATION) {
2723 if (master == dlm->node_num) {
2724 /* ah another process raced me to it */
2725 mlog(0, "tried to migrate %.*s, but some "
2726 "process beat me to it\n",
2727 namelen, name);
2728 ret = -EEXIST;
2729 } else {
2730 /* bad. 2 NODES are trying to migrate! */
2731 mlog(ML_ERROR, "migration error mle: "
2732 "master=%u new_master=%u // request: "
2733 "master=%u new_master=%u // "
2734 "lockres=%.*s\n",
2735 tmp->master, tmp->new_master,
2736 master, new_master,
2737 namelen, name);
2738 BUG();
2739 }
2740 } else {
2741 /* this is essentially what assert_master does */
2742 tmp->master = master;
2743 atomic_set(&tmp->woken, 1);
2744 wake_up(&tmp->wq);
2745 /* remove it from the list so that only one
2746 * mle will be found */
2747 list_del_init(&tmp->list);
Kurt Hackelda01ad02006-04-27 18:53:04 -07002748 __dlm_mle_detach_hb_events(dlm, mle);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08002749 }
2750 spin_unlock(&tmp->spinlock);
2751 }
2752
2753 /* now add a migration mle to the tail of the list */
2754 dlm_init_mle(mle, DLM_MLE_MIGRATION, dlm, res, name, namelen);
2755 mle->new_master = new_master;
2756 mle->master = master;
2757 /* do this for consistency with other mle types */
2758 set_bit(new_master, mle->maybe_map);
2759 list_add(&mle->list, &dlm->master_list);
2760
2761 return ret;
2762}
2763
2764
2765void dlm_clean_master_list(struct dlm_ctxt *dlm, u8 dead_node)
2766{
2767 struct list_head *iter, *iter2;
2768 struct dlm_master_list_entry *mle;
2769 struct dlm_lock_resource *res;
Mark Fasheha3d33292006-03-09 17:55:56 -08002770 unsigned int hash;
Kurt Hackel6714d8e2005-12-15 14:31:23 -08002771
2772 mlog_entry("dlm=%s, dead node=%u\n", dlm->name, dead_node);
2773top:
2774 assert_spin_locked(&dlm->spinlock);
2775
2776 /* clean the master list */
2777 spin_lock(&dlm->master_lock);
2778 list_for_each_safe(iter, iter2, &dlm->master_list) {
2779 mle = list_entry(iter, struct dlm_master_list_entry, list);
2780
2781 BUG_ON(mle->type != DLM_MLE_BLOCK &&
2782 mle->type != DLM_MLE_MASTER &&
2783 mle->type != DLM_MLE_MIGRATION);
2784
2785 /* MASTER mles are initiated locally. the waiting
2786 * process will notice the node map change
2787 * shortly. let that happen as normal. */
2788 if (mle->type == DLM_MLE_MASTER)
2789 continue;
2790
2791
2792 /* BLOCK mles are initiated by other nodes.
2793 * need to clean up if the dead node would have
2794 * been the master. */
2795 if (mle->type == DLM_MLE_BLOCK) {
2796 int bit;
2797
2798 spin_lock(&mle->spinlock);
2799 bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0);
2800 if (bit != dead_node) {
2801 mlog(0, "mle found, but dead node %u would "
2802 "not have been master\n", dead_node);
2803 spin_unlock(&mle->spinlock);
2804 } else {
2805 /* must drop the refcount by one since the
2806 * assert_master will never arrive. this
2807 * may result in the mle being unlinked and
2808 * freed, but there may still be a process
2809 * waiting in the dlmlock path which is fine. */
Kurt Hackel3b3b84a2006-05-01 14:31:37 -07002810 mlog(0, "node %u was expected master\n",
Kurt Hackel6714d8e2005-12-15 14:31:23 -08002811 dead_node);
2812 atomic_set(&mle->woken, 1);
2813 spin_unlock(&mle->spinlock);
2814 wake_up(&mle->wq);
Kurt Hackelf671c092006-02-14 11:45:21 -08002815 /* do not need events any longer, so detach
2816 * from heartbeat */
2817 __dlm_mle_detach_hb_events(dlm, mle);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08002818 __dlm_put_mle(mle);
2819 }
2820 continue;
2821 }
2822
2823 /* everything else is a MIGRATION mle */
2824
2825 /* the rule for MIGRATION mles is that the master
2826 * becomes UNKNOWN if *either* the original or
2827 * the new master dies. all UNKNOWN lockreses
2828 * are sent to whichever node becomes the recovery
2829 * master. the new master is responsible for
2830 * determining if there is still a master for
2831 * this lockres, or if he needs to take over
2832 * mastery. either way, this node should expect
2833 * another message to resolve this. */
2834 if (mle->master != dead_node &&
2835 mle->new_master != dead_node)
2836 continue;
2837
2838 /* if we have reached this point, this mle needs to
2839 * be removed from the list and freed. */
2840
2841 /* remove from the list early. NOTE: unlinking
2842 * list_head while in list_for_each_safe */
Kurt Hackelda01ad02006-04-27 18:53:04 -07002843 __dlm_mle_detach_hb_events(dlm, mle);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08002844 spin_lock(&mle->spinlock);
2845 list_del_init(&mle->list);
2846 atomic_set(&mle->woken, 1);
2847 spin_unlock(&mle->spinlock);
2848 wake_up(&mle->wq);
2849
Kurt Hackelaa852352006-04-27 19:04:49 -07002850 mlog(0, "%s: node %u died during migration from "
2851 "%u to %u!\n", dlm->name, dead_node,
Kurt Hackel6714d8e2005-12-15 14:31:23 -08002852 mle->master, mle->new_master);
2853 /* if there is a lockres associated with this
2854 * mle, find it and set its owner to UNKNOWN */
Mark Fasheha3d33292006-03-09 17:55:56 -08002855 hash = dlm_lockid_hash(mle->u.name.name, mle->u.name.len);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08002856 res = __dlm_lookup_lockres(dlm, mle->u.name.name,
Mark Fasheha3d33292006-03-09 17:55:56 -08002857 mle->u.name.len, hash);
Kurt Hackel6714d8e2005-12-15 14:31:23 -08002858 if (res) {
2859 /* unfortunately if we hit this rare case, our
2860 * lock ordering is messed. we need to drop
2861 * the master lock so that we can take the
2862 * lockres lock, meaning that we will have to
2863 * restart from the head of list. */
2864 spin_unlock(&dlm->master_lock);
2865
2866 /* move lockres onto recovery list */
2867 spin_lock(&res->spinlock);
2868 dlm_set_lockres_owner(dlm, res,
2869 DLM_LOCK_RES_OWNER_UNKNOWN);
2870 dlm_move_lockres_to_recovery_list(dlm, res);
2871 spin_unlock(&res->spinlock);
2872 dlm_lockres_put(res);
2873
Kurt Hackelf671c092006-02-14 11:45:21 -08002874 /* about to get rid of mle, detach from heartbeat */
2875 __dlm_mle_detach_hb_events(dlm, mle);
2876
Kurt Hackel6714d8e2005-12-15 14:31:23 -08002877 /* dump the mle */
2878 spin_lock(&dlm->master_lock);
2879 __dlm_put_mle(mle);
2880 spin_unlock(&dlm->master_lock);
2881
2882 /* restart */
2883 goto top;
2884 }
2885
2886 /* this may be the last reference */
2887 __dlm_put_mle(mle);
2888 }
2889 spin_unlock(&dlm->master_lock);
2890}
2891
2892
2893int dlm_finish_migration(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
2894 u8 old_master)
2895{
2896 struct dlm_node_iter iter;
2897 int ret = 0;
2898
2899 spin_lock(&dlm->spinlock);
2900 dlm_node_iter_init(dlm->domain_map, &iter);
2901 clear_bit(old_master, iter.node_map);
2902 clear_bit(dlm->node_num, iter.node_map);
2903 spin_unlock(&dlm->spinlock);
2904
2905 mlog(0, "now time to do a migrate request to other nodes\n");
2906 ret = dlm_do_migrate_request(dlm, res, old_master,
2907 dlm->node_num, &iter);
2908 if (ret < 0) {
2909 mlog_errno(ret);
2910 goto leave;
2911 }
2912
2913 mlog(0, "doing assert master of %.*s to all except the original node\n",
2914 res->lockname.len, res->lockname.name);
2915 /* this call now finishes out the nodemap
2916 * even if one or more nodes die */
2917 ret = dlm_do_assert_master(dlm, res->lockname.name,
2918 res->lockname.len, iter.node_map,
2919 DLM_ASSERT_MASTER_FINISH_MIGRATION);
2920 if (ret < 0) {
2921 /* no longer need to retry. all living nodes contacted. */
2922 mlog_errno(ret);
2923 ret = 0;
2924 }
2925
2926 memset(iter.node_map, 0, sizeof(iter.node_map));
2927 set_bit(old_master, iter.node_map);
2928 mlog(0, "doing assert master of %.*s back to %u\n",
2929 res->lockname.len, res->lockname.name, old_master);
2930 ret = dlm_do_assert_master(dlm, res->lockname.name,
2931 res->lockname.len, iter.node_map,
2932 DLM_ASSERT_MASTER_FINISH_MIGRATION);
2933 if (ret < 0) {
2934 mlog(0, "assert master to original master failed "
2935 "with %d.\n", ret);
2936 /* the only nonzero status here would be because of
2937 * a dead original node. we're done. */
2938 ret = 0;
2939 }
2940
2941 /* all done, set the owner, clear the flag */
2942 spin_lock(&res->spinlock);
2943 dlm_set_lockres_owner(dlm, res, dlm->node_num);
2944 res->state &= ~DLM_LOCK_RES_MIGRATING;
2945 spin_unlock(&res->spinlock);
2946 /* re-dirty it on the new master */
2947 dlm_kick_thread(dlm, res);
2948 wake_up(&res->wq);
2949leave:
2950 return ret;
2951}
2952
2953/*
2954 * LOCKRES AST REFCOUNT
2955 * this is integral to migration
2956 */
2957
2958/* for future intent to call an ast, reserve one ahead of time.
2959 * this should be called only after waiting on the lockres
2960 * with dlm_wait_on_lockres, and while still holding the
2961 * spinlock after the call. */
2962void __dlm_lockres_reserve_ast(struct dlm_lock_resource *res)
2963{
2964 assert_spin_locked(&res->spinlock);
2965 if (res->state & DLM_LOCK_RES_MIGRATING) {
2966 __dlm_print_one_lock_resource(res);
2967 }
2968 BUG_ON(res->state & DLM_LOCK_RES_MIGRATING);
2969
2970 atomic_inc(&res->asts_reserved);
2971}
2972
2973/*
2974 * used to drop the reserved ast, either because it went unused,
2975 * or because the ast/bast was actually called.
2976 *
2977 * also, if there is a pending migration on this lockres,
2978 * and this was the last pending ast on the lockres,
2979 * atomically set the MIGRATING flag before we drop the lock.
2980 * this is how we ensure that migration can proceed with no
2981 * asts in progress. note that it is ok if the state of the
2982 * queues is such that a lock should be granted in the future
2983 * or that a bast should be fired, because the new master will
2984 * shuffle the lists on this lockres as soon as it is migrated.
2985 */
2986void dlm_lockres_release_ast(struct dlm_ctxt *dlm,
2987 struct dlm_lock_resource *res)
2988{
2989 if (!atomic_dec_and_lock(&res->asts_reserved, &res->spinlock))
2990 return;
2991
2992 if (!res->migration_pending) {
2993 spin_unlock(&res->spinlock);
2994 return;
2995 }
2996
2997 BUG_ON(res->state & DLM_LOCK_RES_MIGRATING);
2998 res->migration_pending = 0;
2999 res->state |= DLM_LOCK_RES_MIGRATING;
3000 spin_unlock(&res->spinlock);
3001 wake_up(&res->wq);
3002 wake_up(&dlm->migration_wq);
3003}