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ocfs2/dlm: Create slabcaches for lock and lockres
[linux-2.6-block.git] / fs / ocfs2 / dlm / dlmmaster.c
CommitLineData
6714d8e8
KH		 1/* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * dlmmod.c
5 *
6 * standalone DLM module
7 *
8 * Copyright (C) 2004 Oracle. All rights reserved.
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public
12 * License as published by the Free Software Foundation; either
13 * version 2 of the License, or (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public
21 * License along with this program; if not, write to the
22 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 * Boston, MA 021110-1307, USA.
24 *
25 */
26
27
28#include <linux/module.h>
29#include <linux/fs.h>
30#include <linux/types.h>
31#include <linux/slab.h>
32#include <linux/highmem.h>
33#include <linux/utsname.h>
34#include <linux/init.h>
35#include <linux/sysctl.h>
36#include <linux/random.h>
37#include <linux/blkdev.h>
38#include <linux/socket.h>
39#include <linux/inet.h>
40#include <linux/spinlock.h>
41#include <linux/delay.h>
42
43
44#include "cluster/heartbeat.h"
45#include "cluster/nodemanager.h"
46#include "cluster/tcp.h"
47
48#include "dlmapi.h"
49#include "dlmcommon.h"
82353b59 50#include "dlmdomain.h"
6714d8e8
KH		 51
52#define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_MASTER)
53#include "cluster/masklog.h"
54
55enum dlm_mle_type {
56 DLM_MLE_BLOCK,
57 DLM_MLE_MASTER,
58 DLM_MLE_MIGRATION
59};
60
61struct dlm_lock_name
62{
63 u8 len;
64 u8 name[DLM_LOCKID_NAME_MAX];
65};
66
67struct dlm_master_list_entry
68{
69 struct list_head list;
70 struct list_head hb_events;
71 struct dlm_ctxt *dlm;
72 spinlock_t spinlock;
73 wait_queue_head_t wq;
74 atomic_t woken;
75 struct kref mle_refs;
a2bf0477 76 int inuse;
6714d8e8
KH		 77 unsigned long maybe_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
78 unsigned long vote_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
79 unsigned long response_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
80 unsigned long node_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
81 u8 master;
82 u8 new_master;
83 enum dlm_mle_type type;
84 struct o2hb_callback_func mle_hb_up;
85 struct o2hb_callback_func mle_hb_down;
86 union {
87 struct dlm_lock_resource *res;
88 struct dlm_lock_name name;
89 } u;
90};
91
92static void dlm_mle_node_down(struct dlm_ctxt *dlm,
93 struct dlm_master_list_entry *mle,
94 struct o2nm_node *node,
95 int idx);
96static void dlm_mle_node_up(struct dlm_ctxt *dlm,
97 struct dlm_master_list_entry *mle,
98 struct o2nm_node *node,
99 int idx);
100
101static void dlm_assert_master_worker(struct dlm_work_item *item, void *data);
ba2bf218
KH		 102static int dlm_do_assert_master(struct dlm_ctxt *dlm,
103 struct dlm_lock_resource *res,
104 void *nodemap, u32 flags);
f3f85464 105static void dlm_deref_lockres_worker(struct dlm_work_item *item, void *data);
6714d8e8
KH		 106
107static inline int dlm_mle_equal(struct dlm_ctxt *dlm,
108 struct dlm_master_list_entry *mle,
109 const char *name,
110 unsigned int namelen)
111{
112 struct dlm_lock_resource *res;
113
114 if (dlm != mle->dlm)
115 return 0;
116
117 if (mle->type == DLM_MLE_BLOCK ||
118 mle->type == DLM_MLE_MIGRATION) {
119 if (namelen != mle->u.name.len ||
120 memcmp(name, mle->u.name.name, namelen)!=0)
121 return 0;
122 } else {
123 res = mle->u.res;
124 if (namelen != res->lockname.len ||
125 memcmp(res->lockname.name, name, namelen) != 0)
126 return 0;
127 }
128 return 1;
129}
130
95883719 131#define dlm_print_nodemap(m) _dlm_print_nodemap(m,#m)
8a9343fa 132static void _dlm_print_nodemap(unsigned long *map, const char *mapname)
95883719
KH		 133{
134 int i;
135 printk("%s=[ ", mapname);
136 for (i=0; i<O2NM_MAX_NODES; i++)
137 if (test_bit(i, map))
138 printk("%d ", i);
139 printk("]");
140}
141
8a9343fa 142static void dlm_print_one_mle(struct dlm_master_list_entry *mle)
6714d8e8 143{
95883719 144 int refs;
6714d8e8
KH		 145 char *type;
146 char attached;
147 u8 master;
148 unsigned int namelen;
149 const char *name;
150 struct kref *k;
95883719
KH		 151 unsigned long *maybe = mle->maybe_map,
152 *vote = mle->vote_map,
153 *resp = mle->response_map,
154 *node = mle->node_map;
6714d8e8
KH		 155
156 k = &mle->mle_refs;
157 if (mle->type == DLM_MLE_BLOCK)
158 type = "BLK";
159 else if (mle->type == DLM_MLE_MASTER)
160 type = "MAS";
161 else
162 type = "MIG";
163 refs = atomic_read(&k->refcount);
164 master = mle->master;
165 attached = (list_empty(&mle->hb_events) ? 'N' : 'Y');
166
167 if (mle->type != DLM_MLE_MASTER) {
168 namelen = mle->u.name.len;
169 name = mle->u.name.name;
170 } else {
171 namelen = mle->u.res->lockname.len;
172 name = mle->u.res->lockname.name;
173 }
174
95883719
KH		 175 mlog(ML_NOTICE, "%.*s: %3s refs=%3d mas=%3u new=%3u evt=%c inuse=%d ",
176 namelen, name, type, refs, master, mle->new_master, attached,
177 mle->inuse);
178 dlm_print_nodemap(maybe);
179 printk(", ");
180 dlm_print_nodemap(vote);
181 printk(", ");
182 dlm_print_nodemap(resp);
183 printk(", ");
184 dlm_print_nodemap(node);
185 printk(", ");
186 printk("\n");
6714d8e8
KH		 187}
188
8a9343fa
MF		 189#if 0
190/* Code here is included but defined out as it aids debugging */
191
6714d8e8
KH		 192static void dlm_dump_mles(struct dlm_ctxt *dlm)
193{
194 struct dlm_master_list_entry *mle;
6714d8e8
KH		 195
196 mlog(ML_NOTICE, "dumping all mles for domain %s:\n", dlm->name);
6714d8e8 197 spin_lock(&dlm->master_lock);
800deef3 198 list_for_each_entry(mle, &dlm->master_list, list)
6714d8e8 199 dlm_print_one_mle(mle);
6714d8e8
KH		 200 spin_unlock(&dlm->master_lock);
201}
202
6714d8e8
KH		 203int dlm_dump_all_mles(const char __user *data, unsigned int len)
204{
6714d8e8
KH		 205 struct dlm_ctxt *dlm;
206
207 spin_lock(&dlm_domain_lock);
800deef3 208 list_for_each_entry(dlm, &dlm_domains, list) {
6714d8e8
KH		 209 mlog(ML_NOTICE, "found dlm: %p, name=%s\n", dlm, dlm->name);
210 dlm_dump_mles(dlm);
211 }
212 spin_unlock(&dlm_domain_lock);
213 return len;
214}
215EXPORT_SYMBOL_GPL(dlm_dump_all_mles);
216
217#endif /* 0 */
218
724bdca9
SM		 219static struct kmem_cache *dlm_lockres_cache = NULL;
220static struct kmem_cache *dlm_lockname_cache = NULL;
e18b890b 221static struct kmem_cache *dlm_mle_cache = NULL;
6714d8e8 222
6714d8e8
KH		 223static void dlm_mle_release(struct kref *kref);
224static void dlm_init_mle(struct dlm_master_list_entry *mle,
225 enum dlm_mle_type type,
226 struct dlm_ctxt *dlm,
227 struct dlm_lock_resource *res,
228 const char *name,
229 unsigned int namelen);
230static void dlm_put_mle(struct dlm_master_list_entry *mle);
231static void __dlm_put_mle(struct dlm_master_list_entry *mle);
232static int dlm_find_mle(struct dlm_ctxt *dlm,
233 struct dlm_master_list_entry **mle,
234 char *name, unsigned int namelen);
235
ba2bf218
KH		 236static int dlm_do_master_request(struct dlm_lock_resource *res,
237 struct dlm_master_list_entry *mle, int to);
6714d8e8
KH		 238
239
240static int dlm_wait_for_lock_mastery(struct dlm_ctxt *dlm,
241 struct dlm_lock_resource *res,
242 struct dlm_master_list_entry *mle,
243 int *blocked);
244static int dlm_restart_lock_mastery(struct dlm_ctxt *dlm,
245 struct dlm_lock_resource *res,
246 struct dlm_master_list_entry *mle,
247 int blocked);
248static int dlm_add_migration_mle(struct dlm_ctxt *dlm,
249 struct dlm_lock_resource *res,
250 struct dlm_master_list_entry *mle,
251 struct dlm_master_list_entry **oldmle,
252 const char *name, unsigned int namelen,
253 u8 new_master, u8 master);
254
255static u8 dlm_pick_migration_target(struct dlm_ctxt *dlm,
256 struct dlm_lock_resource *res);
257static void dlm_remove_nonlocal_locks(struct dlm_ctxt *dlm,
258 struct dlm_lock_resource *res);
259static int dlm_mark_lockres_migrating(struct dlm_ctxt *dlm,
260 struct dlm_lock_resource *res,
261 u8 target);
c03872f5
KH		 262static int dlm_pre_master_reco_lockres(struct dlm_ctxt *dlm,
263 struct dlm_lock_resource *res);
6714d8e8
KH		 264
265
266int dlm_is_host_down(int errno)
267{
268 switch (errno) {
269 case -EBADF:
270 case -ECONNREFUSED:
271 case -ENOTCONN:
272 case -ECONNRESET:
273 case -EPIPE:
274 case -EHOSTDOWN:
275 case -EHOSTUNREACH:
276 case -ETIMEDOUT:
277 case -ECONNABORTED:
278 case -ENETDOWN:
279 case -ENETUNREACH:
280 case -ENETRESET:
281 case -ESHUTDOWN:
282 case -ENOPROTOOPT:
283 case -EINVAL: /* if returned from our tcp code,
284 this means there is no socket */
285 return 1;
286 }
287 return 0;
288}
289
290
291/*
292 * MASTER LIST FUNCTIONS
293 */
294
295
296/*
297 * regarding master list entries and heartbeat callbacks:
298 *
299 * in order to avoid sleeping and allocation that occurs in
300 * heartbeat, master list entries are simply attached to the
301 * dlm's established heartbeat callbacks. the mle is attached
302 * when it is created, and since the dlm->spinlock is held at
303 * that time, any heartbeat event will be properly discovered
304 * by the mle. the mle needs to be detached from the
305 * dlm->mle_hb_events list as soon as heartbeat events are no
306 * longer useful to the mle, and before the mle is freed.
307 *
308 * as a general rule, heartbeat events are no longer needed by
309 * the mle once an "answer" regarding the lock master has been
310 * received.
311 */
312static inline void __dlm_mle_attach_hb_events(struct dlm_ctxt *dlm,
313 struct dlm_master_list_entry *mle)
314{
315 assert_spin_locked(&dlm->spinlock);
316
317 list_add_tail(&mle->hb_events, &dlm->mle_hb_events);
318}
319
320
321static inline void __dlm_mle_detach_hb_events(struct dlm_ctxt *dlm,
322 struct dlm_master_list_entry *mle)
323{
324 if (!list_empty(&mle->hb_events))
325 list_del_init(&mle->hb_events);
326}
327
328
329static inline void dlm_mle_detach_hb_events(struct dlm_ctxt *dlm,
330 struct dlm_master_list_entry *mle)
331{
332 spin_lock(&dlm->spinlock);
333 __dlm_mle_detach_hb_events(dlm, mle);
334 spin_unlock(&dlm->spinlock);
335}
336
a2bf0477
KH		 337static void dlm_get_mle_inuse(struct dlm_master_list_entry *mle)
338{
339 struct dlm_ctxt *dlm;
340 dlm = mle->dlm;
341
342 assert_spin_locked(&dlm->spinlock);
343 assert_spin_locked(&dlm->master_lock);
344 mle->inuse++;
345 kref_get(&mle->mle_refs);
346}
347
348static void dlm_put_mle_inuse(struct dlm_master_list_entry *mle)
349{
350 struct dlm_ctxt *dlm;
351 dlm = mle->dlm;
352
353 spin_lock(&dlm->spinlock);
354 spin_lock(&dlm->master_lock);
355 mle->inuse--;
356 __dlm_put_mle(mle);
357 spin_unlock(&dlm->master_lock);
358 spin_unlock(&dlm->spinlock);
359
360}
361
6714d8e8
KH		 362/* remove from list and free */
363static void __dlm_put_mle(struct dlm_master_list_entry *mle)
364{
365 struct dlm_ctxt *dlm;
366 dlm = mle->dlm;
367
368 assert_spin_locked(&dlm->spinlock);
369 assert_spin_locked(&dlm->master_lock);
aa852354
KH		 370 if (!atomic_read(&mle->mle_refs.refcount)) {
371 /* this may or may not crash, but who cares.
372 * it's a BUG. */
373 mlog(ML_ERROR, "bad mle: %p\n", mle);
374 dlm_print_one_mle(mle);
375 BUG();
376 } else
377 kref_put(&mle->mle_refs, dlm_mle_release);
6714d8e8
KH		 378}
379
380
381/* must not have any spinlocks coming in */
382static void dlm_put_mle(struct dlm_master_list_entry *mle)
383{
384 struct dlm_ctxt *dlm;
385 dlm = mle->dlm;
386
387 spin_lock(&dlm->spinlock);
388 spin_lock(&dlm->master_lock);
389 __dlm_put_mle(mle);
390 spin_unlock(&dlm->master_lock);
391 spin_unlock(&dlm->spinlock);
392}
393
394static inline void dlm_get_mle(struct dlm_master_list_entry *mle)
395{
396 kref_get(&mle->mle_refs);
397}
398
399static void dlm_init_mle(struct dlm_master_list_entry *mle,
400 enum dlm_mle_type type,
401 struct dlm_ctxt *dlm,
402 struct dlm_lock_resource *res,
403 const char *name,
404 unsigned int namelen)
405{
406 assert_spin_locked(&dlm->spinlock);
407
408 mle->dlm = dlm;
409 mle->type = type;
410 INIT_LIST_HEAD(&mle->list);
411 INIT_LIST_HEAD(&mle->hb_events);
412 memset(mle->maybe_map, 0, sizeof(mle->maybe_map));
413 spin_lock_init(&mle->spinlock);
414 init_waitqueue_head(&mle->wq);
415 atomic_set(&mle->woken, 0);
416 kref_init(&mle->mle_refs);
417 memset(mle->response_map, 0, sizeof(mle->response_map));
418 mle->master = O2NM_MAX_NODES;
419 mle->new_master = O2NM_MAX_NODES;
a2bf0477 420 mle->inuse = 0;
6714d8e8
KH		 421
422 if (mle->type == DLM_MLE_MASTER) {
423 BUG_ON(!res);
424 mle->u.res = res;
425 } else if (mle->type == DLM_MLE_BLOCK) {
426 BUG_ON(!name);
427 memcpy(mle->u.name.name, name, namelen);
428 mle->u.name.len = namelen;
429 } else /* DLM_MLE_MIGRATION */ {
430 BUG_ON(!name);
431 memcpy(mle->u.name.name, name, namelen);
432 mle->u.name.len = namelen;
433 }
434
435 /* copy off the node_map and register hb callbacks on our copy */
436 memcpy(mle->node_map, dlm->domain_map, sizeof(mle->node_map));
437 memcpy(mle->vote_map, dlm->domain_map, sizeof(mle->vote_map));
438 clear_bit(dlm->node_num, mle->vote_map);
439 clear_bit(dlm->node_num, mle->node_map);
440
441 /* attach the mle to the domain node up/down events */
442 __dlm_mle_attach_hb_events(dlm, mle);
443}
444
445
446/* returns 1 if found, 0 if not */
447static int dlm_find_mle(struct dlm_ctxt *dlm,
448 struct dlm_master_list_entry **mle,
449 char *name, unsigned int namelen)
450{
451 struct dlm_master_list_entry *tmpmle;
6714d8e8
KH		 452
453 assert_spin_locked(&dlm->master_lock);
454
800deef3 455 list_for_each_entry(tmpmle, &dlm->master_list, list) {
6714d8e8
KH		 456 if (!dlm_mle_equal(dlm, tmpmle, name, namelen))
457 continue;
458 dlm_get_mle(tmpmle);
459 *mle = tmpmle;
460 return 1;
461 }
462 return 0;
463}
464
465void dlm_hb_event_notify_attached(struct dlm_ctxt *dlm, int idx, int node_up)
466{
467 struct dlm_master_list_entry *mle;
6714d8e8
KH		 468
469 assert_spin_locked(&dlm->spinlock);
470
800deef3 471 list_for_each_entry(mle, &dlm->mle_hb_events, hb_events) {
6714d8e8
KH		 472 if (node_up)
473 dlm_mle_node_up(dlm, mle, NULL, idx);
474 else
475 dlm_mle_node_down(dlm, mle, NULL, idx);
476 }
477}
478
479static void dlm_mle_node_down(struct dlm_ctxt *dlm,
480 struct dlm_master_list_entry *mle,
481 struct o2nm_node *node, int idx)
482{
483 spin_lock(&mle->spinlock);
484
485 if (!test_bit(idx, mle->node_map))
486 mlog(0, "node %u already removed from nodemap!\n", idx);
487 else
488 clear_bit(idx, mle->node_map);
489
490 spin_unlock(&mle->spinlock);
491}
492
493static void dlm_mle_node_up(struct dlm_ctxt *dlm,
494 struct dlm_master_list_entry *mle,
495 struct o2nm_node *node, int idx)
496{
497 spin_lock(&mle->spinlock);
498
499 if (test_bit(idx, mle->node_map))
500 mlog(0, "node %u already in node map!\n", idx);
501 else
502 set_bit(idx, mle->node_map);
503
504 spin_unlock(&mle->spinlock);
505}
506
507
508int dlm_init_mle_cache(void)
509{
12eb0035 510 dlm_mle_cache = kmem_cache_create("o2dlm_mle",
6714d8e8
KH		 511 sizeof(struct dlm_master_list_entry),
512 0, SLAB_HWCACHE_ALIGN,
20c2df83 513 NULL);
6714d8e8
KH		 514 if (dlm_mle_cache == NULL)
515 return -ENOMEM;
516 return 0;
517}
518
519void dlm_destroy_mle_cache(void)
520{
521 if (dlm_mle_cache)
522 kmem_cache_destroy(dlm_mle_cache);
523}
524
525static void dlm_mle_release(struct kref *kref)
526{
527 struct dlm_master_list_entry *mle;
528 struct dlm_ctxt *dlm;
529
530 mlog_entry_void();
531
532 mle = container_of(kref, struct dlm_master_list_entry, mle_refs);
533 dlm = mle->dlm;
534
535 if (mle->type != DLM_MLE_MASTER) {
536 mlog(0, "calling mle_release for %.*s, type %d\n",
537 mle->u.name.len, mle->u.name.name, mle->type);
538 } else {
539 mlog(0, "calling mle_release for %.*s, type %d\n",
540 mle->u.res->lockname.len,
541 mle->u.res->lockname.name, mle->type);
542 }
543 assert_spin_locked(&dlm->spinlock);
544 assert_spin_locked(&dlm->master_lock);
545
546 /* remove from list if not already */
547 if (!list_empty(&mle->list))
548 list_del_init(&mle->list);
549
550 /* detach the mle from the domain node up/down events */
551 __dlm_mle_detach_hb_events(dlm, mle);
552
553 /* NOTE: kfree under spinlock here.
554 * if this is bad, we can move this to a freelist. */
555 kmem_cache_free(dlm_mle_cache, mle);
556}
557
558
559/*
560 * LOCK RESOURCE FUNCTIONS
561 */
562
724bdca9
SM		 563int dlm_init_master_caches(void)
564{
565 dlm_lockres_cache = kmem_cache_create("o2dlm_lockres",
566 sizeof(struct dlm_lock_resource),
567 0, SLAB_HWCACHE_ALIGN, NULL);
568 if (!dlm_lockres_cache)
569 goto bail;
570
571 dlm_lockname_cache = kmem_cache_create("o2dlm_lockname",
572 DLM_LOCKID_NAME_MAX, 0,
573 SLAB_HWCACHE_ALIGN, NULL);
574 if (!dlm_lockname_cache)
575 goto bail;
576
577 return 0;
578bail:
579 dlm_destroy_master_caches();
580 return -ENOMEM;
581}
582
583void dlm_destroy_master_caches(void)
584{
585 if (dlm_lockname_cache)
586 kmem_cache_destroy(dlm_lockname_cache);
587
588 if (dlm_lockres_cache)
589 kmem_cache_destroy(dlm_lockres_cache);
590}
591
6714d8e8
KH		 592static void dlm_set_lockres_owner(struct dlm_ctxt *dlm,
593 struct dlm_lock_resource *res,
594 u8 owner)
595{
596 assert_spin_locked(&res->spinlock);
597
598 mlog_entry("%.*s, %u\n", res->lockname.len, res->lockname.name, owner);
599
600 if (owner == dlm->node_num)
601 atomic_inc(&dlm->local_resources);
602 else if (owner == DLM_LOCK_RES_OWNER_UNKNOWN)
603 atomic_inc(&dlm->unknown_resources);
604 else
605 atomic_inc(&dlm->remote_resources);
606
607 res->owner = owner;
608}
609
610void dlm_change_lockres_owner(struct dlm_ctxt *dlm,
611 struct dlm_lock_resource *res, u8 owner)
612{
613 assert_spin_locked(&res->spinlock);
614
615 if (owner == res->owner)
616 return;
617
618 if (res->owner == dlm->node_num)
619 atomic_dec(&dlm->local_resources);
620 else if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN)
621 atomic_dec(&dlm->unknown_resources);
622 else
623 atomic_dec(&dlm->remote_resources);
624
625 dlm_set_lockres_owner(dlm, res, owner);
626}
627
628
629static void dlm_lockres_release(struct kref *kref)
630{
631 struct dlm_lock_resource *res;
632
633 res = container_of(kref, struct dlm_lock_resource, refs);
634
635 /* This should not happen -- all lockres' have a name
636 * associated with them at init time. */
637 BUG_ON(!res->lockname.name);
638
639 mlog(0, "destroying lockres %.*s\n", res->lockname.len,
640 res->lockname.name);
641
a7f90d83
KH		 642 if (!hlist_unhashed(&res->hash_node) ||
643 !list_empty(&res->granted) ||
644 !list_empty(&res->converting) ||
645 !list_empty(&res->blocked) ||
646 !list_empty(&res->dirty) ||
647 !list_empty(&res->recovering) ||
648 !list_empty(&res->purge)) {
649 mlog(ML_ERROR,
650 "Going to BUG for resource %.*s."
651 " We're on a list! [%c%c%c%c%c%c%c]\n",
652 res->lockname.len, res->lockname.name,
653 !hlist_unhashed(&res->hash_node) ? 'H' : ' ',
654 !list_empty(&res->granted) ? 'G' : ' ',
655 !list_empty(&res->converting) ? 'C' : ' ',
656 !list_empty(&res->blocked) ? 'B' : ' ',
657 !list_empty(&res->dirty) ? 'D' : ' ',
658 !list_empty(&res->recovering) ? 'R' : ' ',
659 !list_empty(&res->purge) ? 'P' : ' ');
660
661 dlm_print_one_lock_resource(res);
662 }
663
6714d8e8
KH		 664 /* By the time we're ready to blow this guy away, we shouldn't
665 * be on any lists. */
81f2094a 666 BUG_ON(!hlist_unhashed(&res->hash_node));
6714d8e8
KH		 667 BUG_ON(!list_empty(&res->granted));
668 BUG_ON(!list_empty(&res->converting));
669 BUG_ON(!list_empty(&res->blocked));
670 BUG_ON(!list_empty(&res->dirty));
671 BUG_ON(!list_empty(&res->recovering));
672 BUG_ON(!list_empty(&res->purge));
673
724bdca9 674 kmem_cache_free(dlm_lockname_cache, (void *)res->lockname.name);
6714d8e8 675
724bdca9 676 kmem_cache_free(dlm_lockres_cache, res);
6714d8e8
KH		 677}
678
6714d8e8
KH		 679void dlm_lockres_put(struct dlm_lock_resource *res)
680{
681 kref_put(&res->refs, dlm_lockres_release);
682}
683
684static void dlm_init_lockres(struct dlm_ctxt *dlm,
685 struct dlm_lock_resource *res,
686 const char *name, unsigned int namelen)
687{
688 char *qname;
689
690 /* If we memset here, we lose our reference to the kmalloc'd
691 * res->lockname.name, so be sure to init every field
692 * correctly! */
693
694 qname = (char *) res->lockname.name;
695 memcpy(qname, name, namelen);
696
697 res->lockname.len = namelen;
a3d33291 698 res->lockname.hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 699
700 init_waitqueue_head(&res->wq);
701 spin_lock_init(&res->spinlock);
81f2094a 702 INIT_HLIST_NODE(&res->hash_node);
6714d8e8
KH		 703 INIT_LIST_HEAD(&res->granted);
704 INIT_LIST_HEAD(&res->converting);
705 INIT_LIST_HEAD(&res->blocked);
706 INIT_LIST_HEAD(&res->dirty);
707 INIT_LIST_HEAD(&res->recovering);
708 INIT_LIST_HEAD(&res->purge);
709 atomic_set(&res->asts_reserved, 0);
710 res->migration_pending = 0;
ba2bf218 711 res->inflight_locks = 0;
6714d8e8
KH		 712
713 kref_init(&res->refs);
714
715 /* just for consistency */
716 spin_lock(&res->spinlock);
717 dlm_set_lockres_owner(dlm, res, DLM_LOCK_RES_OWNER_UNKNOWN);
718 spin_unlock(&res->spinlock);
719
720 res->state = DLM_LOCK_RES_IN_PROGRESS;
721
722 res->last_used = 0;
723
724 memset(res->lvb, 0, DLM_LVB_LEN);
ba2bf218 725 memset(res->refmap, 0, sizeof(res->refmap));
6714d8e8
KH		 726}
727
728struct dlm_lock_resource *dlm_new_lockres(struct dlm_ctxt *dlm,
729 const char *name,
730 unsigned int namelen)
731{
724bdca9 732 struct dlm_lock_resource *res = NULL;
6714d8e8 733
724bdca9
SM		 734 res = (struct dlm_lock_resource *)
735 kmem_cache_zalloc(dlm_lockres_cache, GFP_NOFS);
6714d8e8 736 if (!res)
724bdca9 737 goto error;
6714d8e8 738
724bdca9
SM		 739 res->lockname.name = (char *)
740 kmem_cache_zalloc(dlm_lockname_cache, GFP_NOFS);
741 if (!res->lockname.name)
742 goto error;
6714d8e8
KH		 743
744 dlm_init_lockres(dlm, res, name, namelen);
745 return res;
724bdca9
SM		 746
747error:
748 if (res && res->lockname.name)
749 kmem_cache_free(dlm_lockname_cache, (void *)res->lockname.name);
750
751 if (res)
752 kmem_cache_free(dlm_lockres_cache, res);
753 return NULL;
6714d8e8
KH		 754}
755
ba2bf218
KH		 756void __dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm,
757 struct dlm_lock_resource *res,
758 int new_lockres,
759 const char *file,
760 int line)
761{
762 if (!new_lockres)
763 assert_spin_locked(&res->spinlock);
764
765 if (!test_bit(dlm->node_num, res->refmap)) {
766 BUG_ON(res->inflight_locks != 0);
767 dlm_lockres_set_refmap_bit(dlm->node_num, res);
768 }
769 res->inflight_locks++;
770 mlog(0, "%s:%.*s: inflight++: now %u\n",
771 dlm->name, res->lockname.len, res->lockname.name,
772 res->inflight_locks);
773}
774
775void __dlm_lockres_drop_inflight_ref(struct dlm_ctxt *dlm,
776 struct dlm_lock_resource *res,
777 const char *file,
778 int line)
779{
780 assert_spin_locked(&res->spinlock);
781
782 BUG_ON(res->inflight_locks == 0);
783 res->inflight_locks--;
784 mlog(0, "%s:%.*s: inflight--: now %u\n",
785 dlm->name, res->lockname.len, res->lockname.name,
786 res->inflight_locks);
787 if (res->inflight_locks == 0)
788 dlm_lockres_clear_refmap_bit(dlm->node_num, res);
789 wake_up(&res->wq);
790}
791
6714d8e8
KH		 792/*
793 * lookup a lock resource by name.
794 * may already exist in the hashtable.
795 * lockid is null terminated
796 *
797 * if not, allocate enough for the lockres and for
798 * the temporary structure used in doing the mastering.
799 *
800 * also, do a lookup in the dlm->master_list to see
801 * if another node has begun mastering the same lock.
802 * if so, there should be a block entry in there
803 * for this name, and we should *not* attempt to master
804 * the lock here. need to wait around for that node
805 * to assert_master (or die).
806 *
807 */
808struct dlm_lock_resource * dlm_get_lock_resource(struct dlm_ctxt *dlm,
809 const char *lockid,
3384f3df 810 int namelen,
6714d8e8
KH		 811 int flags)
812{
813 struct dlm_lock_resource *tmpres=NULL, *res=NULL;
814 struct dlm_master_list_entry *mle = NULL;
815 struct dlm_master_list_entry *alloc_mle = NULL;
816 int blocked = 0;
817 int ret, nodenum;
818 struct dlm_node_iter iter;
3384f3df 819 unsigned int hash;
6714d8e8 820 int tries = 0;
c03872f5 821 int bit, wait_on_recovery = 0;
ba2bf218 822 int drop_inflight_if_nonlocal = 0;
6714d8e8
KH		 823
824 BUG_ON(!lockid);
825
a3d33291 826 hash = dlm_lockid_hash(lockid, namelen);
6714d8e8
KH		 827
828 mlog(0, "get lockres %s (len %d)\n", lockid, namelen);
829
830lookup:
831 spin_lock(&dlm->spinlock);
ba2bf218 832 tmpres = __dlm_lookup_lockres_full(dlm, lockid, namelen, hash);
6714d8e8 833 if (tmpres) {
ba2bf218
KH		 834 int dropping_ref = 0;
835
836 spin_lock(&tmpres->spinlock);
837 if (tmpres->owner == dlm->node_num) {
838 BUG_ON(tmpres->state & DLM_LOCK_RES_DROPPING_REF);
839 dlm_lockres_grab_inflight_ref(dlm, tmpres);
840 } else if (tmpres->state & DLM_LOCK_RES_DROPPING_REF)
841 dropping_ref = 1;
842 spin_unlock(&tmpres->spinlock);
6714d8e8 843 spin_unlock(&dlm->spinlock);
ba2bf218
KH		 844
845 /* wait until done messaging the master, drop our ref to allow
846 * the lockres to be purged, start over. */
847 if (dropping_ref) {
848 spin_lock(&tmpres->spinlock);
849 __dlm_wait_on_lockres_flags(tmpres, DLM_LOCK_RES_DROPPING_REF);
850 spin_unlock(&tmpres->spinlock);
851 dlm_lockres_put(tmpres);
852 tmpres = NULL;
853 goto lookup;
854 }
855
6714d8e8
KH		 856 mlog(0, "found in hash!\n");
857 if (res)
858 dlm_lockres_put(res);
859 res = tmpres;
860 goto leave;
861 }
862
863 if (!res) {
864 spin_unlock(&dlm->spinlock);
865 mlog(0, "allocating a new resource\n");
866 /* nothing found and we need to allocate one. */
867 alloc_mle = (struct dlm_master_list_entry *)
ad8100e0 868 kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
6714d8e8
KH		 869 if (!alloc_mle)
870 goto leave;
871 res = dlm_new_lockres(dlm, lockid, namelen);
872 if (!res)
873 goto leave;
874 goto lookup;
875 }
876
877 mlog(0, "no lockres found, allocated our own: %p\n", res);
878
879 if (flags & LKM_LOCAL) {
880 /* caller knows it's safe to assume it's not mastered elsewhere
881 * DONE! return right away */
882 spin_lock(&res->spinlock);
883 dlm_change_lockres_owner(dlm, res, dlm->node_num);
884 __dlm_insert_lockres(dlm, res);
ba2bf218 885 dlm_lockres_grab_inflight_ref(dlm, res);
6714d8e8
KH		 886 spin_unlock(&res->spinlock);
887 spin_unlock(&dlm->spinlock);
888 /* lockres still marked IN_PROGRESS */
889 goto wake_waiters;
890 }
891
892 /* check master list to see if another node has started mastering it */
893 spin_lock(&dlm->master_lock);
894
895 /* if we found a block, wait for lock to be mastered by another node */
896 blocked = dlm_find_mle(dlm, &mle, (char *)lockid, namelen);
897 if (blocked) {
ba2bf218 898 int mig;
6714d8e8
KH		 899 if (mle->type == DLM_MLE_MASTER) {
900 mlog(ML_ERROR, "master entry for nonexistent lock!\n");
901 BUG();
ba2bf218
KH		 902 }
903 mig = (mle->type == DLM_MLE_MIGRATION);
904 /* if there is a migration in progress, let the migration
905 * finish before continuing. we can wait for the absence
906 * of the MIGRATION mle: either the migrate finished or
907 * one of the nodes died and the mle was cleaned up.
908 * if there is a BLOCK here, but it already has a master
909 * set, we are too late. the master does not have a ref
910 * for us in the refmap. detach the mle and drop it.
911 * either way, go back to the top and start over. */
912 if (mig || mle->master != O2NM_MAX_NODES) {
913 BUG_ON(mig && mle->master == dlm->node_num);
914 /* we arrived too late. the master does not
915 * have a ref for us. retry. */
916 mlog(0, "%s:%.*s: late on %s\n",
917 dlm->name, namelen, lockid,
918 mig ? "MIGRATION" : "BLOCK");
6714d8e8 919 spin_unlock(&dlm->master_lock);
6714d8e8
KH		 920 spin_unlock(&dlm->spinlock);
921
922 /* master is known, detach */
ba2bf218
KH		 923 if (!mig)
924 dlm_mle_detach_hb_events(dlm, mle);
6714d8e8
KH		 925 dlm_put_mle(mle);
926 mle = NULL;
ba2bf218
KH		 927 /* this is lame, but we cant wait on either
928 * the mle or lockres waitqueue here */
929 if (mig)
930 msleep(100);
931 goto lookup;
6714d8e8
KH		 932 }
933 } else {
934 /* go ahead and try to master lock on this node */
935 mle = alloc_mle;
936 /* make sure this does not get freed below */
937 alloc_mle = NULL;
938 dlm_init_mle(mle, DLM_MLE_MASTER, dlm, res, NULL, 0);
939 set_bit(dlm->node_num, mle->maybe_map);
940 list_add(&mle->list, &dlm->master_list);
c03872f5
KH		 941
942 /* still holding the dlm spinlock, check the recovery map
943 * to see if there are any nodes that still need to be
944 * considered. these will not appear in the mle nodemap
945 * but they might own this lockres. wait on them. */
946 bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0);
947 if (bit < O2NM_MAX_NODES) {
2759236f 948 mlog(ML_NOTICE, "%s:%.*s: at least one node (%d) to "
c03872f5
KH		 949 "recover before lock mastery can begin\n",
950 dlm->name, namelen, (char *)lockid, bit);
951 wait_on_recovery = 1;
952 }
6714d8e8
KH		 953 }
954
955 /* at this point there is either a DLM_MLE_BLOCK or a
956 * DLM_MLE_MASTER on the master list, so it's safe to add the
957 * lockres to the hashtable. anyone who finds the lock will
958 * still have to wait on the IN_PROGRESS. */
959
960 /* finally add the lockres to its hash bucket */
961 __dlm_insert_lockres(dlm, res);
ba2bf218
KH		 962 /* since this lockres is new it doesnt not require the spinlock */
963 dlm_lockres_grab_inflight_ref_new(dlm, res);
964
965 /* if this node does not become the master make sure to drop
966 * this inflight reference below */
967 drop_inflight_if_nonlocal = 1;
968
6714d8e8
KH		 969 /* get an extra ref on the mle in case this is a BLOCK
970 * if so, the creator of the BLOCK may try to put the last
971 * ref at this time in the assert master handler, so we
972 * need an extra one to keep from a bad ptr deref. */
a2bf0477 973 dlm_get_mle_inuse(mle);
6714d8e8
KH		 974 spin_unlock(&dlm->master_lock);
975 spin_unlock(&dlm->spinlock);
976
e7e69eb3 977redo_request:
c03872f5
KH		 978 while (wait_on_recovery) {
979 /* any cluster changes that occurred after dropping the
980 * dlm spinlock would be detectable be a change on the mle,
981 * so we only need to clear out the recovery map once. */
982 if (dlm_is_recovery_lock(lockid, namelen)) {
983 mlog(ML_NOTICE, "%s: recovery map is not empty, but "
984 "must master $RECOVERY lock now\n", dlm->name);
985 if (!dlm_pre_master_reco_lockres(dlm, res))
986 wait_on_recovery = 0;
987 else {
988 mlog(0, "%s: waiting 500ms for heartbeat state "
989 "change\n", dlm->name);
990 msleep(500);
991 }
992 continue;
993 }
994
995 dlm_kick_recovery_thread(dlm);
aa087b84 996 msleep(1000);
c03872f5
KH		 997 dlm_wait_for_recovery(dlm);
998
999 spin_lock(&dlm->spinlock);
1000 bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0);
1001 if (bit < O2NM_MAX_NODES) {
2759236f 1002 mlog(ML_NOTICE, "%s:%.*s: at least one node (%d) to "
c03872f5
KH		 1003 "recover before lock mastery can begin\n",
1004 dlm->name, namelen, (char *)lockid, bit);
1005 wait_on_recovery = 1;
1006 } else
1007 wait_on_recovery = 0;
1008 spin_unlock(&dlm->spinlock);
b7084ab5
KH		 1009
1010 if (wait_on_recovery)
1011 dlm_wait_for_node_recovery(dlm, bit, 10000);
c03872f5
KH		 1012 }
1013
6714d8e8
KH		 1014 /* must wait for lock to be mastered elsewhere */
1015 if (blocked)
1016 goto wait;
1017
6714d8e8
KH		 1018 ret = -EINVAL;
1019 dlm_node_iter_init(mle->vote_map, &iter);
1020 while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
ba2bf218 1021 ret = dlm_do_master_request(res, mle, nodenum);
6714d8e8
KH		 1022 if (ret < 0)
1023 mlog_errno(ret);
1024 if (mle->master != O2NM_MAX_NODES) {
1025 /* found a master ! */
9c6510a5
KH		 1026 if (mle->master <= nodenum)
1027 break;
1028 /* if our master request has not reached the master
1029 * yet, keep going until it does. this is how the
1030 * master will know that asserts are needed back to
1031 * the lower nodes. */
1032 mlog(0, "%s:%.*s: requests only up to %u but master "
1033 "is %u, keep going\n", dlm->name, namelen,
1034 lockid, nodenum, mle->master);
6714d8e8
KH		 1035 }
1036 }
1037
1038wait:
1039 /* keep going until the response map includes all nodes */
1040 ret = dlm_wait_for_lock_mastery(dlm, res, mle, &blocked);
1041 if (ret < 0) {
e7e69eb3 1042 wait_on_recovery = 1;
6714d8e8
KH		 1043 mlog(0, "%s:%.*s: node map changed, redo the "
1044 "master request now, blocked=%d\n",
1045 dlm->name, res->lockname.len,
1046 res->lockname.name, blocked);
1047 if (++tries > 20) {
1048 mlog(ML_ERROR, "%s:%.*s: spinning on "
1049 "dlm_wait_for_lock_mastery, blocked=%d\n",
1050 dlm->name, res->lockname.len,
1051 res->lockname.name, blocked);
1052 dlm_print_one_lock_resource(res);
8a9343fa 1053 dlm_print_one_mle(mle);
6714d8e8
KH		 1054 tries = 0;
1055 }
1056 goto redo_request;
1057 }
1058
1059 mlog(0, "lockres mastered by %u\n", res->owner);
1060 /* make sure we never continue without this */
1061 BUG_ON(res->owner == O2NM_MAX_NODES);
1062
1063 /* master is known, detach if not already detached */
1064 dlm_mle_detach_hb_events(dlm, mle);
1065 dlm_put_mle(mle);
1066 /* put the extra ref */
a2bf0477 1067 dlm_put_mle_inuse(mle);
6714d8e8
KH		 1068
1069wake_waiters:
1070 spin_lock(&res->spinlock);
ba2bf218
KH		 1071 if (res->owner != dlm->node_num && drop_inflight_if_nonlocal)
1072 dlm_lockres_drop_inflight_ref(dlm, res);
6714d8e8
KH		 1073 res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
1074 spin_unlock(&res->spinlock);
1075 wake_up(&res->wq);
1076
1077leave:
1078 /* need to free the unused mle */
1079 if (alloc_mle)
1080 kmem_cache_free(dlm_mle_cache, alloc_mle);
1081
1082 return res;
1083}
1084
1085
1086#define DLM_MASTERY_TIMEOUT_MS 5000
1087
1088static int dlm_wait_for_lock_mastery(struct dlm_ctxt *dlm,
1089 struct dlm_lock_resource *res,
1090 struct dlm_master_list_entry *mle,
1091 int *blocked)
1092{
1093 u8 m;
1094 int ret, bit;
1095 int map_changed, voting_done;
1096 int assert, sleep;
1097
1098recheck:
1099 ret = 0;
1100 assert = 0;
1101
1102 /* check if another node has already become the owner */
1103 spin_lock(&res->spinlock);
1104 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
9c6510a5
KH		 1105 mlog(0, "%s:%.*s: owner is suddenly %u\n", dlm->name,
1106 res->lockname.len, res->lockname.name, res->owner);
6714d8e8 1107 spin_unlock(&res->spinlock);
9c6510a5
KH		 1108 /* this will cause the master to re-assert across
1109 * the whole cluster, freeing up mles */
588e0090 1110 if (res->owner != dlm->node_num) {
ba2bf218 1111 ret = dlm_do_master_request(res, mle, res->owner);
588e0090
KH		 1112 if (ret < 0) {
1113 /* give recovery a chance to run */
1114 mlog(ML_ERROR, "link to %u went down?: %d\n", res->owner, ret);
1115 msleep(500);
1116 goto recheck;
1117 }
9c6510a5
KH		 1118 }
1119 ret = 0;
6714d8e8
KH		 1120 goto leave;
1121 }
1122 spin_unlock(&res->spinlock);
1123
1124 spin_lock(&mle->spinlock);
1125 m = mle->master;
1126 map_changed = (memcmp(mle->vote_map, mle->node_map,
1127 sizeof(mle->vote_map)) != 0);
1128 voting_done = (memcmp(mle->vote_map, mle->response_map,
1129 sizeof(mle->vote_map)) == 0);
1130
1131 /* restart if we hit any errors */
1132 if (map_changed) {
1133 int b;
1134 mlog(0, "%s: %.*s: node map changed, restarting\n",
1135 dlm->name, res->lockname.len, res->lockname.name);
1136 ret = dlm_restart_lock_mastery(dlm, res, mle, *blocked);
1137 b = (mle->type == DLM_MLE_BLOCK);
1138 if ((*blocked && !b) || (!*blocked && b)) {
1139 mlog(0, "%s:%.*s: status change: old=%d new=%d\n",
1140 dlm->name, res->lockname.len, res->lockname.name,
1141 *blocked, b);
1142 *blocked = b;
1143 }
1144 spin_unlock(&mle->spinlock);
1145 if (ret < 0) {
1146 mlog_errno(ret);
1147 goto leave;
1148 }
1149 mlog(0, "%s:%.*s: restart lock mastery succeeded, "
1150 "rechecking now\n", dlm->name, res->lockname.len,
1151 res->lockname.name);
1152 goto recheck;
aa852354
KH		 1153 } else {
1154 if (!voting_done) {
1155 mlog(0, "map not changed and voting not done "
1156 "for %s:%.*s\n", dlm->name, res->lockname.len,
1157 res->lockname.name);
1158 }
6714d8e8
KH		 1159 }
1160
1161 if (m != O2NM_MAX_NODES) {
1162 /* another node has done an assert!
1163 * all done! */
1164 sleep = 0;
1165 } else {
1166 sleep = 1;
1167 /* have all nodes responded? */
1168 if (voting_done && !*blocked) {
1169 bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0);
1170 if (dlm->node_num <= bit) {
1171 /* my node number is lowest.
1172 * now tell other nodes that I am
1173 * mastering this. */
1174 mle->master = dlm->node_num;
ba2bf218
KH		 1175 /* ref was grabbed in get_lock_resource
1176 * will be dropped in dlmlock_master */
6714d8e8
KH		 1177 assert = 1;
1178 sleep = 0;
1179 }
1180 /* if voting is done, but we have not received
1181 * an assert master yet, we must sleep */
1182 }
1183 }
1184
1185 spin_unlock(&mle->spinlock);
1186
1187 /* sleep if we haven't finished voting yet */
1188 if (sleep) {
1189 unsigned long timeo = msecs_to_jiffies(DLM_MASTERY_TIMEOUT_MS);
1190
1191 /*
1192 if (atomic_read(&mle->mle_refs.refcount) < 2)
1193 mlog(ML_ERROR, "mle (%p) refs=%d, name=%.*s\n", mle,
1194 atomic_read(&mle->mle_refs.refcount),
1195 res->lockname.len, res->lockname.name);
1196 */
1197 atomic_set(&mle->woken, 0);
1198 (void)wait_event_timeout(mle->wq,
1199 (atomic_read(&mle->woken) == 1),
1200 timeo);
1201 if (res->owner == O2NM_MAX_NODES) {
ba2bf218
KH		 1202 mlog(0, "%s:%.*s: waiting again\n", dlm->name,
1203 res->lockname.len, res->lockname.name);
6714d8e8
KH		 1204 goto recheck;
1205 }
1206 mlog(0, "done waiting, master is %u\n", res->owner);
1207 ret = 0;
1208 goto leave;
1209 }
1210
1211 ret = 0; /* done */
1212 if (assert) {
1213 m = dlm->node_num;
1214 mlog(0, "about to master %.*s here, this=%u\n",
1215 res->lockname.len, res->lockname.name, m);
ba2bf218 1216 ret = dlm_do_assert_master(dlm, res, mle->vote_map, 0);
6714d8e8
KH		 1217 if (ret) {
1218 /* This is a failure in the network path,
1219 * not in the response to the assert_master
1220 * (any nonzero response is a BUG on this node).
1221 * Most likely a socket just got disconnected
1222 * due to node death. */
1223 mlog_errno(ret);
1224 }
1225 /* no longer need to restart lock mastery.
1226 * all living nodes have been contacted. */
1227 ret = 0;
1228 }
1229
1230 /* set the lockres owner */
1231 spin_lock(&res->spinlock);
ba2bf218
KH		 1232 /* mastery reference obtained either during
1233 * assert_master_handler or in get_lock_resource */
6714d8e8
KH		 1234 dlm_change_lockres_owner(dlm, res, m);
1235 spin_unlock(&res->spinlock);
1236
1237leave:
1238 return ret;
1239}
1240
1241struct dlm_bitmap_diff_iter
1242{
1243 int curnode;
1244 unsigned long *orig_bm;
1245 unsigned long *cur_bm;
1246 unsigned long diff_bm[BITS_TO_LONGS(O2NM_MAX_NODES)];
1247};
1248
1249enum dlm_node_state_change
1250{
1251 NODE_DOWN = -1,
1252 NODE_NO_CHANGE = 0,
1253 NODE_UP
1254};
1255
1256static void dlm_bitmap_diff_iter_init(struct dlm_bitmap_diff_iter *iter,
1257 unsigned long *orig_bm,
1258 unsigned long *cur_bm)
1259{
1260 unsigned long p1, p2;
1261 int i;
1262
1263 iter->curnode = -1;
1264 iter->orig_bm = orig_bm;
1265 iter->cur_bm = cur_bm;
1266
1267 for (i = 0; i < BITS_TO_LONGS(O2NM_MAX_NODES); i++) {
1268 p1 = *(iter->orig_bm + i);
1269 p2 = *(iter->cur_bm + i);
1270 iter->diff_bm[i] = (p1 & ~p2) | (p2 & ~p1);
1271 }
1272}
1273
1274static int dlm_bitmap_diff_iter_next(struct dlm_bitmap_diff_iter *iter,
1275 enum dlm_node_state_change *state)
1276{
1277 int bit;
1278
1279 if (iter->curnode >= O2NM_MAX_NODES)
1280 return -ENOENT;
1281
1282 bit = find_next_bit(iter->diff_bm, O2NM_MAX_NODES,
1283 iter->curnode+1);
1284 if (bit >= O2NM_MAX_NODES) {
1285 iter->curnode = O2NM_MAX_NODES;
1286 return -ENOENT;
1287 }
1288
1289 /* if it was there in the original then this node died */
1290 if (test_bit(bit, iter->orig_bm))
1291 *state = NODE_DOWN;
1292 else
1293 *state = NODE_UP;
1294
1295 iter->curnode = bit;
1296 return bit;
1297}
1298
1299
1300static int dlm_restart_lock_mastery(struct dlm_ctxt *dlm,
1301 struct dlm_lock_resource *res,
1302 struct dlm_master_list_entry *mle,
1303 int blocked)
1304{
1305 struct dlm_bitmap_diff_iter bdi;
1306 enum dlm_node_state_change sc;
1307 int node;
1308 int ret = 0;
1309
1310 mlog(0, "something happened such that the "
1311 "master process may need to be restarted!\n");
1312
1313 assert_spin_locked(&mle->spinlock);
1314
1315 dlm_bitmap_diff_iter_init(&bdi, mle->vote_map, mle->node_map);
1316 node = dlm_bitmap_diff_iter_next(&bdi, &sc);
1317 while (node >= 0) {
1318 if (sc == NODE_UP) {
e2faea4c
KH		 1319 /* a node came up. clear any old vote from
1320 * the response map and set it in the vote map
1321 * then restart the mastery. */
1322 mlog(ML_NOTICE, "node %d up while restarting\n", node);
6714d8e8
KH		 1323
1324 /* redo the master request, but only for the new node */
1325 mlog(0, "sending request to new node\n");
1326 clear_bit(node, mle->response_map);
1327 set_bit(node, mle->vote_map);
1328 } else {
1329 mlog(ML_ERROR, "node down! %d\n", node);
6714d8e8
KH		 1330 if (blocked) {
1331 int lowest = find_next_bit(mle->maybe_map,
1332 O2NM_MAX_NODES, 0);
1333
1334 /* act like it was never there */
1335 clear_bit(node, mle->maybe_map);
1336
e7e69eb3
KH		 1337 if (node == lowest) {
1338 mlog(0, "expected master %u died"
1339 " while this node was blocked "
1340 "waiting on it!\n", node);
1341 lowest = find_next_bit(mle->maybe_map,
1342 O2NM_MAX_NODES,
1343 lowest+1);
1344 if (lowest < O2NM_MAX_NODES) {
1345 mlog(0, "%s:%.*s:still "
1346 "blocked. waiting on %u "
1347 "now\n", dlm->name,
1348 res->lockname.len,
1349 res->lockname.name,
1350 lowest);
1351 } else {
1352 /* mle is an MLE_BLOCK, but
1353 * there is now nothing left to
1354 * block on. we need to return
1355 * all the way back out and try
1356 * again with an MLE_MASTER.
1357 * dlm_do_local_recovery_cleanup
1358 * has already run, so the mle
1359 * refcount is ok */
1360 mlog(0, "%s:%.*s: no "
1361 "longer blocking. try to "
1362 "master this here\n",
1363 dlm->name,
1364 res->lockname.len,
1365 res->lockname.name);
1366 mle->type = DLM_MLE_MASTER;
1367 mle->u.res = res;
1368 }
6714d8e8 1369 }
6714d8e8
KH		 1370 }
1371
e7e69eb3
KH		 1372 /* now blank out everything, as if we had never
1373 * contacted anyone */
1374 memset(mle->maybe_map, 0, sizeof(mle->maybe_map));
1375 memset(mle->response_map, 0, sizeof(mle->response_map));
1376 /* reset the vote_map to the current node_map */
1377 memcpy(mle->vote_map, mle->node_map,
1378 sizeof(mle->node_map));
1379 /* put myself into the maybe map */
1380 if (mle->type != DLM_MLE_BLOCK)
1381 set_bit(dlm->node_num, mle->maybe_map);
6714d8e8
KH		 1382 }
1383 ret = -EAGAIN;
6714d8e8
KH		 1384 node = dlm_bitmap_diff_iter_next(&bdi, &sc);
1385 }
1386 return ret;
1387}
1388
1389
1390/*
1391 * DLM_MASTER_REQUEST_MSG
1392 *
1393 * returns: 0 on success,
1394 * -errno on a network error
1395 *
1396 * on error, the caller should assume the target node is "dead"
1397 *
1398 */
1399
ba2bf218
KH		 1400static int dlm_do_master_request(struct dlm_lock_resource *res,
1401 struct dlm_master_list_entry *mle, int to)
6714d8e8
KH		 1402{
1403 struct dlm_ctxt *dlm = mle->dlm;
1404 struct dlm_master_request request;
1405 int ret, response=0, resend;
1406
1407 memset(&request, 0, sizeof(request));
1408 request.node_idx = dlm->node_num;
1409
1410 BUG_ON(mle->type == DLM_MLE_MIGRATION);
1411
1412 if (mle->type != DLM_MLE_MASTER) {
1413 request.namelen = mle->u.name.len;
1414 memcpy(request.name, mle->u.name.name, request.namelen);
1415 } else {
1416 request.namelen = mle->u.res->lockname.len;
1417 memcpy(request.name, mle->u.res->lockname.name,
1418 request.namelen);
1419 }
1420
1421again:
1422 ret = o2net_send_message(DLM_MASTER_REQUEST_MSG, dlm->key, &request,
1423 sizeof(request), to, &response);
1424 if (ret < 0) {
1425 if (ret == -ESRCH) {
1426 /* should never happen */
1427 mlog(ML_ERROR, "TCP stack not ready!\n");
1428 BUG();
1429 } else if (ret == -EINVAL) {
1430 mlog(ML_ERROR, "bad args passed to o2net!\n");
1431 BUG();
1432 } else if (ret == -ENOMEM) {
1433 mlog(ML_ERROR, "out of memory while trying to send "
1434 "network message! retrying\n");
1435 /* this is totally crude */
1436 msleep(50);
1437 goto again;
1438 } else if (!dlm_is_host_down(ret)) {
1439 /* not a network error. bad. */
1440 mlog_errno(ret);
1441 mlog(ML_ERROR, "unhandled error!");
1442 BUG();
1443 }
1444 /* all other errors should be network errors,
1445 * and likely indicate node death */
1446 mlog(ML_ERROR, "link to %d went down!\n", to);
1447 goto out;
1448 }
1449
1450 ret = 0;
1451 resend = 0;
1452 spin_lock(&mle->spinlock);
1453 switch (response) {
1454 case DLM_MASTER_RESP_YES:
1455 set_bit(to, mle->response_map);
1456 mlog(0, "node %u is the master, response=YES\n", to);
ba2bf218
KH		 1457 mlog(0, "%s:%.*s: master node %u now knows I have a "
1458 "reference\n", dlm->name, res->lockname.len,
1459 res->lockname.name, to);
6714d8e8
KH		 1460 mle->master = to;
1461 break;
1462 case DLM_MASTER_RESP_NO:
1463 mlog(0, "node %u not master, response=NO\n", to);
1464 set_bit(to, mle->response_map);
1465 break;
1466 case DLM_MASTER_RESP_MAYBE:
1467 mlog(0, "node %u not master, response=MAYBE\n", to);
1468 set_bit(to, mle->response_map);
1469 set_bit(to, mle->maybe_map);
1470 break;
1471 case DLM_MASTER_RESP_ERROR:
1472 mlog(0, "node %u hit an error, resending\n", to);
1473 resend = 1;
1474 response = 0;
1475 break;
1476 default:
1477 mlog(ML_ERROR, "bad response! %u\n", response);
1478 BUG();
1479 }
1480 spin_unlock(&mle->spinlock);
1481 if (resend) {
1482 /* this is also totally crude */
1483 msleep(50);
1484 goto again;
1485 }
1486
1487out:
1488 return ret;
1489}
1490
1491/*
1492 * locks that can be taken here:
1493 * dlm->spinlock
1494 * res->spinlock
1495 * mle->spinlock
1496 * dlm->master_list
1497 *
1498 * if possible, TRIM THIS DOWN!!!
1499 */
d74c9803
KH		 1500int dlm_master_request_handler(struct o2net_msg *msg, u32 len, void *data,
1501 void **ret_data)
6714d8e8
KH		 1502{
1503 u8 response = DLM_MASTER_RESP_MAYBE;
1504 struct dlm_ctxt *dlm = data;
9c6510a5 1505 struct dlm_lock_resource *res = NULL;
6714d8e8
KH		 1506 struct dlm_master_request *request = (struct dlm_master_request *) msg->buf;
1507 struct dlm_master_list_entry *mle = NULL, *tmpmle = NULL;
1508 char *name;
a3d33291 1509 unsigned int namelen, hash;
6714d8e8
KH		 1510 int found, ret;
1511 int set_maybe;
9c6510a5 1512 int dispatch_assert = 0;
6714d8e8
KH		 1513
1514 if (!dlm_grab(dlm))
1515 return DLM_MASTER_RESP_NO;
1516
1517 if (!dlm_domain_fully_joined(dlm)) {
1518 response = DLM_MASTER_RESP_NO;
1519 goto send_response;
1520 }
1521
1522 name = request->name;
1523 namelen = request->namelen;
a3d33291 1524 hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 1525
1526 if (namelen > DLM_LOCKID_NAME_MAX) {
1527 response = DLM_IVBUFLEN;
1528 goto send_response;
1529 }
1530
1531way_up_top:
1532 spin_lock(&dlm->spinlock);
a3d33291 1533 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
6714d8e8
KH		 1534 if (res) {
1535 spin_unlock(&dlm->spinlock);
1536
1537 /* take care of the easy cases up front */
1538 spin_lock(&res->spinlock);
1cd04dbe
KH		 1539 if (res->state & (DLM_LOCK_RES_RECOVERING|
1540 DLM_LOCK_RES_MIGRATING)) {
6714d8e8
KH		 1541 spin_unlock(&res->spinlock);
1542 mlog(0, "returning DLM_MASTER_RESP_ERROR since res is "
1cd04dbe 1543 "being recovered/migrated\n");
6714d8e8
KH		 1544 response = DLM_MASTER_RESP_ERROR;
1545 if (mle)
1546 kmem_cache_free(dlm_mle_cache, mle);
1547 goto send_response;
1548 }
1549
1550 if (res->owner == dlm->node_num) {
ba2bf218
KH		 1551 mlog(0, "%s:%.*s: setting bit %u in refmap\n",
1552 dlm->name, namelen, name, request->node_idx);
1553 dlm_lockres_set_refmap_bit(request->node_idx, res);
6714d8e8 1554 spin_unlock(&res->spinlock);
6714d8e8
KH		 1555 response = DLM_MASTER_RESP_YES;
1556 if (mle)
1557 kmem_cache_free(dlm_mle_cache, mle);
1558
1559 /* this node is the owner.
1560 * there is some extra work that needs to
1561 * happen now. the requesting node has
1562 * caused all nodes up to this one to
1563 * create mles. this node now needs to
1564 * go back and clean those up. */
9c6510a5 1565 dispatch_assert = 1;
6714d8e8
KH		 1566 goto send_response;
1567 } else if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
1568 spin_unlock(&res->spinlock);
1569 // mlog(0, "node %u is the master\n", res->owner);
1570 response = DLM_MASTER_RESP_NO;
1571 if (mle)
1572 kmem_cache_free(dlm_mle_cache, mle);
1573 goto send_response;
1574 }
1575
1576 /* ok, there is no owner. either this node is
1577 * being blocked, or it is actively trying to
1578 * master this lock. */
1579 if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) {
1580 mlog(ML_ERROR, "lock with no owner should be "
1581 "in-progress!\n");
1582 BUG();
1583 }
1584
1585 // mlog(0, "lockres is in progress...\n");
1586 spin_lock(&dlm->master_lock);
1587 found = dlm_find_mle(dlm, &tmpmle, name, namelen);
1588 if (!found) {
1589 mlog(ML_ERROR, "no mle found for this lock!\n");
1590 BUG();
1591 }
1592 set_maybe = 1;
1593 spin_lock(&tmpmle->spinlock);
1594 if (tmpmle->type == DLM_MLE_BLOCK) {
1595 // mlog(0, "this node is waiting for "
1596 // "lockres to be mastered\n");
1597 response = DLM_MASTER_RESP_NO;
1598 } else if (tmpmle->type == DLM_MLE_MIGRATION) {
1599 mlog(0, "node %u is master, but trying to migrate to "
1600 "node %u.\n", tmpmle->master, tmpmle->new_master);
1601 if (tmpmle->master == dlm->node_num) {
6714d8e8
KH		 1602 mlog(ML_ERROR, "no owner on lockres, but this "
1603 "node is trying to migrate it to %u?!\n",
1604 tmpmle->new_master);
1605 BUG();
1606 } else {
1607 /* the real master can respond on its own */
1608 response = DLM_MASTER_RESP_NO;
1609 }
1610 } else if (tmpmle->master != DLM_LOCK_RES_OWNER_UNKNOWN) {
1611 set_maybe = 0;
9c6510a5 1612 if (tmpmle->master == dlm->node_num) {
6714d8e8 1613 response = DLM_MASTER_RESP_YES;
9c6510a5
KH		 1614 /* this node will be the owner.
1615 * go back and clean the mles on any
1616 * other nodes */
1617 dispatch_assert = 1;
ba2bf218
KH		 1618 dlm_lockres_set_refmap_bit(request->node_idx, res);
1619 mlog(0, "%s:%.*s: setting bit %u in refmap\n",
1620 dlm->name, namelen, name,
1621 request->node_idx);
9c6510a5 1622 } else
6714d8e8
KH		 1623 response = DLM_MASTER_RESP_NO;
1624 } else {
1625 // mlog(0, "this node is attempting to "
1626 // "master lockres\n");
1627 response = DLM_MASTER_RESP_MAYBE;
1628 }
1629 if (set_maybe)
1630 set_bit(request->node_idx, tmpmle->maybe_map);
1631 spin_unlock(&tmpmle->spinlock);
1632
1633 spin_unlock(&dlm->master_lock);
1634 spin_unlock(&res->spinlock);
1635
1636 /* keep the mle attached to heartbeat events */
1637 dlm_put_mle(tmpmle);
1638 if (mle)
1639 kmem_cache_free(dlm_mle_cache, mle);
1640 goto send_response;
1641 }
1642
1643 /*
1644 * lockres doesn't exist on this node
1645 * if there is an MLE_BLOCK, return NO
1646 * if there is an MLE_MASTER, return MAYBE
1647 * otherwise, add an MLE_BLOCK, return NO
1648 */
1649 spin_lock(&dlm->master_lock);
1650 found = dlm_find_mle(dlm, &tmpmle, name, namelen);
1651 if (!found) {
1652 /* this lockid has never been seen on this node yet */
1653 // mlog(0, "no mle found\n");
1654 if (!mle) {
1655 spin_unlock(&dlm->master_lock);
1656 spin_unlock(&dlm->spinlock);
1657
1658 mle = (struct dlm_master_list_entry *)
ad8100e0 1659 kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
6714d8e8 1660 if (!mle) {
6714d8e8 1661 response = DLM_MASTER_RESP_ERROR;
9c6510a5 1662 mlog_errno(-ENOMEM);
6714d8e8
KH		 1663 goto send_response;
1664 }
6714d8e8
KH		 1665 goto way_up_top;
1666 }
1667
1668 // mlog(0, "this is second time thru, already allocated, "
1669 // "add the block.\n");
41b8c8a1 1670 dlm_init_mle(mle, DLM_MLE_BLOCK, dlm, NULL, name, namelen);
6714d8e8
KH		 1671 set_bit(request->node_idx, mle->maybe_map);
1672 list_add(&mle->list, &dlm->master_list);
1673 response = DLM_MASTER_RESP_NO;
1674 } else {
1675 // mlog(0, "mle was found\n");
1676 set_maybe = 1;
1677 spin_lock(&tmpmle->spinlock);
9c6510a5
KH		 1678 if (tmpmle->master == dlm->node_num) {
1679 mlog(ML_ERROR, "no lockres, but an mle with this node as master!\n");
1680 BUG();
1681 }
6714d8e8
KH		 1682 if (tmpmle->type == DLM_MLE_BLOCK)
1683 response = DLM_MASTER_RESP_NO;
1684 else if (tmpmle->type == DLM_MLE_MIGRATION) {
1685 mlog(0, "migration mle was found (%u->%u)\n",
1686 tmpmle->master, tmpmle->new_master);
6714d8e8
KH		 1687 /* real master can respond on its own */
1688 response = DLM_MASTER_RESP_NO;
9c6510a5
KH		 1689 } else
1690 response = DLM_MASTER_RESP_MAYBE;
6714d8e8
KH		 1691 if (set_maybe)
1692 set_bit(request->node_idx, tmpmle->maybe_map);
1693 spin_unlock(&tmpmle->spinlock);
1694 }
1695 spin_unlock(&dlm->master_lock);
1696 spin_unlock(&dlm->spinlock);
1697
1698 if (found) {
1699 /* keep the mle attached to heartbeat events */
1700 dlm_put_mle(tmpmle);
1701 }
1702send_response:
b31cfc02
SM		 1703 /*
1704 * __dlm_lookup_lockres() grabbed a reference to this lockres.
1705 * The reference is released by dlm_assert_master_worker() under
1706 * the call to dlm_dispatch_assert_master(). If
1707 * dlm_assert_master_worker() isn't called, we drop it here.
1708 */
9c6510a5
KH		 1709 if (dispatch_assert) {
1710 if (response != DLM_MASTER_RESP_YES)
1711 mlog(ML_ERROR, "invalid response %d\n", response);
1712 if (!res) {
1713 mlog(ML_ERROR, "bad lockres while trying to assert!\n");
1714 BUG();
1715 }
1716 mlog(0, "%u is the owner of %.*s, cleaning everyone else\n",
1717 dlm->node_num, res->lockname.len, res->lockname.name);
1718 ret = dlm_dispatch_assert_master(dlm, res, 0, request->node_idx,
1719 DLM_ASSERT_MASTER_MLE_CLEANUP);
1720 if (ret < 0) {
1721 mlog(ML_ERROR, "failed to dispatch assert master work\n");
1722 response = DLM_MASTER_RESP_ERROR;
b31cfc02 1723 dlm_lockres_put(res);
9c6510a5 1724 }
b31cfc02
SM		 1725 } else {
1726 if (res)
1727 dlm_lockres_put(res);
9c6510a5
KH		 1728 }
1729
6714d8e8
KH		 1730 dlm_put(dlm);
1731 return response;
1732}
1733
1734/*
1735 * DLM_ASSERT_MASTER_MSG
1736 */
1737
1738
1739/*
1740 * NOTE: this can be used for debugging
1741 * can periodically run all locks owned by this node
1742 * and re-assert across the cluster...
1743 */
05488bbe
AB		 1744static int dlm_do_assert_master(struct dlm_ctxt *dlm,
1745 struct dlm_lock_resource *res,
1746 void *nodemap, u32 flags)
6714d8e8
KH		 1747{
1748 struct dlm_assert_master assert;
1749 int to, tmpret;
1750 struct dlm_node_iter iter;
1751 int ret = 0;
9c6510a5 1752 int reassert;
ba2bf218
KH		 1753 const char *lockname = res->lockname.name;
1754 unsigned int namelen = res->lockname.len;
6714d8e8
KH		 1755
1756 BUG_ON(namelen > O2NM_MAX_NAME_LEN);
f3f85464
SM		 1757
1758 spin_lock(&res->spinlock);
1759 res->state |= DLM_LOCK_RES_SETREF_INPROG;
1760 spin_unlock(&res->spinlock);
1761
9c6510a5
KH		 1762again:
1763 reassert = 0;
6714d8e8
KH		 1764
1765 /* note that if this nodemap is empty, it returns 0 */
1766 dlm_node_iter_init(nodemap, &iter);
1767 while ((to = dlm_node_iter_next(&iter)) >= 0) {
1768 int r = 0;
a9ee4c8a
KH		 1769 struct dlm_master_list_entry *mle = NULL;
1770
6714d8e8
KH		 1771 mlog(0, "sending assert master to %d (%.*s)\n", to,
1772 namelen, lockname);
1773 memset(&assert, 0, sizeof(assert));
1774 assert.node_idx = dlm->node_num;
1775 assert.namelen = namelen;
1776 memcpy(assert.name, lockname, namelen);
1777 assert.flags = cpu_to_be32(flags);
1778
1779 tmpret = o2net_send_message(DLM_ASSERT_MASTER_MSG, dlm->key,
1780 &assert, sizeof(assert), to, &r);
1781 if (tmpret < 0) {
3b3b84a8 1782 mlog(0, "assert_master returned %d!\n", tmpret);
6714d8e8 1783 if (!dlm_is_host_down(tmpret)) {
3b3b84a8 1784 mlog(ML_ERROR, "unhandled error=%d!\n", tmpret);
6714d8e8
KH		 1785 BUG();
1786 }
1787 /* a node died. finish out the rest of the nodes. */
3b3b84a8 1788 mlog(0, "link to %d went down!\n", to);
6714d8e8
KH		 1789 /* any nonzero status return will do */
1790 ret = tmpret;
ba2bf218 1791 r = 0;
6714d8e8
KH		 1792 } else if (r < 0) {
1793 /* ok, something horribly messed. kill thyself. */
1794 mlog(ML_ERROR,"during assert master of %.*s to %u, "
1795 "got %d.\n", namelen, lockname, to, r);
a9ee4c8a
KH		 1796 spin_lock(&dlm->spinlock);
1797 spin_lock(&dlm->master_lock);
1798 if (dlm_find_mle(dlm, &mle, (char *)lockname,
1799 namelen)) {
1800 dlm_print_one_mle(mle);
1801 __dlm_put_mle(mle);
1802 }
1803 spin_unlock(&dlm->master_lock);
1804 spin_unlock(&dlm->spinlock);
6714d8e8 1805 BUG();
ba2bf218
KH		 1806 }
1807
1808 if (r & DLM_ASSERT_RESPONSE_REASSERT &&
1809 !(r & DLM_ASSERT_RESPONSE_MASTERY_REF)) {
1810 mlog(ML_ERROR, "%.*s: very strange, "
1811 "master MLE but no lockres on %u\n",
1812 namelen, lockname, to);
1813 }
1814
1815 if (r & DLM_ASSERT_RESPONSE_REASSERT) {
9c6510a5
KH		 1816 mlog(0, "%.*s: node %u create mles on other "
1817 "nodes and requests a re-assert\n",
1818 namelen, lockname, to);
1819 reassert = 1;
6714d8e8 1820 }
ba2bf218
KH		 1821 if (r & DLM_ASSERT_RESPONSE_MASTERY_REF) {
1822 mlog(0, "%.*s: node %u has a reference to this "
1823 "lockres, set the bit in the refmap\n",
1824 namelen, lockname, to);
1825 spin_lock(&res->spinlock);
1826 dlm_lockres_set_refmap_bit(to, res);
1827 spin_unlock(&res->spinlock);
1828 }
6714d8e8
KH		 1829 }
1830
9c6510a5
KH		 1831 if (reassert)
1832 goto again;
1833
f3f85464
SM		 1834 spin_lock(&res->spinlock);
1835 res->state &= ~DLM_LOCK_RES_SETREF_INPROG;
1836 spin_unlock(&res->spinlock);
1837 wake_up(&res->wq);
1838
6714d8e8
KH		 1839 return ret;
1840}
1841
1842/*
1843 * locks that can be taken here:
1844 * dlm->spinlock
1845 * res->spinlock
1846 * mle->spinlock
1847 * dlm->master_list
1848 *
1849 * if possible, TRIM THIS DOWN!!!
1850 */
d74c9803
KH		 1851int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data,
1852 void **ret_data)
6714d8e8
KH		 1853{
1854 struct dlm_ctxt *dlm = data;
1855 struct dlm_master_list_entry *mle = NULL;
1856 struct dlm_assert_master *assert = (struct dlm_assert_master *)msg->buf;
1857 struct dlm_lock_resource *res = NULL;
1858 char *name;
a3d33291 1859 unsigned int namelen, hash;
6714d8e8 1860 u32 flags;
ba2bf218 1861 int master_request = 0, have_lockres_ref = 0;
9c6510a5 1862 int ret = 0;
6714d8e8
KH		 1863
1864 if (!dlm_grab(dlm))
1865 return 0;
1866
1867 name = assert->name;
1868 namelen = assert->namelen;
a3d33291 1869 hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 1870 flags = be32_to_cpu(assert->flags);
1871
1872 if (namelen > DLM_LOCKID_NAME_MAX) {
1873 mlog(ML_ERROR, "Invalid name length!");
1874 goto done;
1875 }
1876
1877 spin_lock(&dlm->spinlock);
1878
1879 if (flags)
1880 mlog(0, "assert_master with flags: %u\n", flags);
1881
1882 /* find the MLE */
1883 spin_lock(&dlm->master_lock);
1884 if (!dlm_find_mle(dlm, &mle, name, namelen)) {
1885 /* not an error, could be master just re-asserting */
1886 mlog(0, "just got an assert_master from %u, but no "
1887 "MLE for it! (%.*s)\n", assert->node_idx,
1888 namelen, name);
1889 } else {
1890 int bit = find_next_bit (mle->maybe_map, O2NM_MAX_NODES, 0);
1891 if (bit >= O2NM_MAX_NODES) {
1892 /* not necessarily an error, though less likely.
1893 * could be master just re-asserting. */
aa852354 1894 mlog(0, "no bits set in the maybe_map, but %u "
6714d8e8
KH		 1895 "is asserting! (%.*s)\n", assert->node_idx,
1896 namelen, name);
1897 } else if (bit != assert->node_idx) {
1898 if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) {
1899 mlog(0, "master %u was found, %u should "
1900 "back off\n", assert->node_idx, bit);
1901 } else {
1902 /* with the fix for bug 569, a higher node
1903 * number winning the mastery will respond
1904 * YES to mastery requests, but this node
1905 * had no way of knowing. let it pass. */
aa852354 1906 mlog(0, "%u is the lowest node, "
6714d8e8
KH		 1907 "%u is asserting. (%.*s) %u must "
1908 "have begun after %u won.\n", bit,
1909 assert->node_idx, namelen, name, bit,
1910 assert->node_idx);
1911 }
1912 }
2d1a868c
KH		 1913 if (mle->type == DLM_MLE_MIGRATION) {
1914 if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) {
1915 mlog(0, "%s:%.*s: got cleanup assert"
1916 " from %u for migration\n",
1917 dlm->name, namelen, name,
1918 assert->node_idx);
1919 } else if (!(flags & DLM_ASSERT_MASTER_FINISH_MIGRATION)) {
1920 mlog(0, "%s:%.*s: got unrelated assert"
1921 " from %u for migration, ignoring\n",
1922 dlm->name, namelen, name,
1923 assert->node_idx);
1924 __dlm_put_mle(mle);
1925 spin_unlock(&dlm->master_lock);
1926 spin_unlock(&dlm->spinlock);
1927 goto done;
1928 }
1929 }
6714d8e8
KH		 1930 }
1931 spin_unlock(&dlm->master_lock);
1932
1933 /* ok everything checks out with the MLE
1934 * now check to see if there is a lockres */
a3d33291 1935 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
6714d8e8
KH		 1936 if (res) {
1937 spin_lock(&res->spinlock);
1938 if (res->state & DLM_LOCK_RES_RECOVERING) {
1939 mlog(ML_ERROR, "%u asserting but %.*s is "
1940 "RECOVERING!\n", assert->node_idx, namelen, name);
1941 goto kill;
1942 }
1943 if (!mle) {
dc2ed195
KH		 1944 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN &&
1945 res->owner != assert->node_idx) {
6714d8e8
KH		 1946 mlog(ML_ERROR, "assert_master from "
1947 "%u, but current owner is "
1948 "%u! (%.*s)\n",
1949 assert->node_idx, res->owner,
1950 namelen, name);
1951 goto kill;
1952 }
1953 } else if (mle->type != DLM_MLE_MIGRATION) {
1954 if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
1955 /* owner is just re-asserting */
1956 if (res->owner == assert->node_idx) {
1957 mlog(0, "owner %u re-asserting on "
1958 "lock %.*s\n", assert->node_idx,
1959 namelen, name);
1960 goto ok;
1961 }
1962 mlog(ML_ERROR, "got assert_master from "
1963 "node %u, but %u is the owner! "
1964 "(%.*s)\n", assert->node_idx,
1965 res->owner, namelen, name);
1966 goto kill;
1967 }
1968 if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) {
1969 mlog(ML_ERROR, "got assert from %u, but lock "
1970 "with no owner should be "
1971 "in-progress! (%.*s)\n",
1972 assert->node_idx,
1973 namelen, name);
1974 goto kill;
1975 }
1976 } else /* mle->type == DLM_MLE_MIGRATION */ {
1977 /* should only be getting an assert from new master */
1978 if (assert->node_idx != mle->new_master) {
1979 mlog(ML_ERROR, "got assert from %u, but "
1980 "new master is %u, and old master "
1981 "was %u (%.*s)\n",
1982 assert->node_idx, mle->new_master,
1983 mle->master, namelen, name);
1984 goto kill;
1985 }
1986
1987 }
1988ok:
1989 spin_unlock(&res->spinlock);
1990 }
1991 spin_unlock(&dlm->spinlock);
1992
1993 // mlog(0, "woo! got an assert_master from node %u!\n",
1994 // assert->node_idx);
1995 if (mle) {
9c6510a5
KH		 1996 int extra_ref = 0;
1997 int nn = -1;
a2bf0477 1998 int rr, err = 0;
6714d8e8
KH		 1999
2000 spin_lock(&mle->spinlock);
9c6510a5
KH		 2001 if (mle->type == DLM_MLE_BLOCK || mle->type == DLM_MLE_MIGRATION)
2002 extra_ref = 1;
2003 else {
2004 /* MASTER mle: if any bits set in the response map
2005 * then the calling node needs to re-assert to clear
2006 * up nodes that this node contacted */
2007 while ((nn = find_next_bit (mle->response_map, O2NM_MAX_NODES,
2008 nn+1)) < O2NM_MAX_NODES) {
2009 if (nn != dlm->node_num && nn != assert->node_idx)
2010 master_request = 1;
2011 }
2012 }
6714d8e8
KH		 2013 mle->master = assert->node_idx;
2014 atomic_set(&mle->woken, 1);
2015 wake_up(&mle->wq);
2016 spin_unlock(&mle->spinlock);
2017
a2bf0477 2018 if (res) {
a6fa3640 2019 int wake = 0;
6714d8e8 2020 spin_lock(&res->spinlock);
a2bf0477
KH		 2021 if (mle->type == DLM_MLE_MIGRATION) {
2022 mlog(0, "finishing off migration of lockres %.*s, "
2023 "from %u to %u\n",
2024 res->lockname.len, res->lockname.name,
2025 dlm->node_num, mle->new_master);
2026 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 2027 wake = 1;
a2bf0477
KH		 2028 dlm_change_lockres_owner(dlm, res, mle->new_master);
2029 BUG_ON(res->state & DLM_LOCK_RES_DIRTY);
2030 } else {
2031 dlm_change_lockres_owner(dlm, res, mle->master);
2032 }
6714d8e8 2033 spin_unlock(&res->spinlock);
ba2bf218 2034 have_lockres_ref = 1;
a6fa3640
KH		 2035 if (wake)
2036 wake_up(&res->wq);
6714d8e8 2037 }
a2bf0477
KH		 2038
2039 /* master is known, detach if not already detached.
2040 * ensures that only one assert_master call will happen
2041 * on this mle. */
2042 spin_lock(&dlm->spinlock);
2043 spin_lock(&dlm->master_lock);
2044
2045 rr = atomic_read(&mle->mle_refs.refcount);
2046 if (mle->inuse > 0) {
2047 if (extra_ref && rr < 3)
2048 err = 1;
2049 else if (!extra_ref && rr < 2)
2050 err = 1;
2051 } else {
2052 if (extra_ref && rr < 2)
2053 err = 1;
2054 else if (!extra_ref && rr < 1)
2055 err = 1;
2056 }
2057 if (err) {
2058 mlog(ML_ERROR, "%s:%.*s: got assert master from %u "
2059 "that will mess up this node, refs=%d, extra=%d, "
2060 "inuse=%d\n", dlm->name, namelen, name,
2061 assert->node_idx, rr, extra_ref, mle->inuse);
2062 dlm_print_one_mle(mle);
2063 }
2064 list_del_init(&mle->list);
2065 __dlm_mle_detach_hb_events(dlm, mle);
2066 __dlm_put_mle(mle);
6714d8e8
KH		 2067 if (extra_ref) {
2068 /* the assert master message now balances the extra
2069 * ref given by the master / migration request message.
2070 * if this is the last put, it will be removed
2071 * from the list. */
a2bf0477
KH		 2072 __dlm_put_mle(mle);
2073 }
2074 spin_unlock(&dlm->master_lock);
2075 spin_unlock(&dlm->spinlock);
2076 } else if (res) {
2077 if (res->owner != assert->node_idx) {
2078 mlog(0, "assert_master from %u, but current "
2079 "owner is %u (%.*s), no mle\n", assert->node_idx,
2080 res->owner, namelen, name);
6714d8e8
KH		 2081 }
2082 }
2083
2084done:
9c6510a5 2085 ret = 0;
3b8118cf
KH		 2086 if (res) {
2087 spin_lock(&res->spinlock);
2088 res->state |= DLM_LOCK_RES_SETREF_INPROG;
2089 spin_unlock(&res->spinlock);
2090 *ret_data = (void *)res;
2091 }
6714d8e8 2092 dlm_put(dlm);
9c6510a5
KH		 2093 if (master_request) {
2094 mlog(0, "need to tell master to reassert\n");
ba2bf218
KH		 2095 /* positive. negative would shoot down the node. */
2096 ret |= DLM_ASSERT_RESPONSE_REASSERT;
2097 if (!have_lockres_ref) {
2098 mlog(ML_ERROR, "strange, got assert from %u, MASTER "
2099 "mle present here for %s:%.*s, but no lockres!\n",
2100 assert->node_idx, dlm->name, namelen, name);
2101 }
2102 }
2103 if (have_lockres_ref) {
2104 /* let the master know we have a reference to the lockres */
2105 ret |= DLM_ASSERT_RESPONSE_MASTERY_REF;
2106 mlog(0, "%s:%.*s: got assert from %u, need a ref\n",
2107 dlm->name, namelen, name, assert->node_idx);
9c6510a5
KH		 2108 }
2109 return ret;
6714d8e8
KH		 2110
2111kill:
2112 /* kill the caller! */
a9ee4c8a
KH		 2113 mlog(ML_ERROR, "Bad message received from another node. Dumping state "
2114 "and killing the other node now! This node is OK and can continue.\n");
2115 __dlm_print_one_lock_resource(res);
6714d8e8
KH		 2116 spin_unlock(&res->spinlock);
2117 spin_unlock(&dlm->spinlock);
3b8118cf 2118 *ret_data = (void *)res;
6714d8e8
KH		 2119 dlm_put(dlm);
2120 return -EINVAL;
2121}
2122
3b8118cf
KH		 2123void dlm_assert_master_post_handler(int status, void *data, void *ret_data)
2124{
2125 struct dlm_lock_resource *res = (struct dlm_lock_resource *)ret_data;
2126
2127 if (ret_data) {
2128 spin_lock(&res->spinlock);
2129 res->state &= ~DLM_LOCK_RES_SETREF_INPROG;
2130 spin_unlock(&res->spinlock);
2131 wake_up(&res->wq);
2132 dlm_lockres_put(res);
2133 }
2134 return;
2135}
2136
6714d8e8
KH		 2137int dlm_dispatch_assert_master(struct dlm_ctxt *dlm,
2138 struct dlm_lock_resource *res,
2139 int ignore_higher, u8 request_from, u32 flags)
2140{
2141 struct dlm_work_item *item;
cd861280 2142 item = kzalloc(sizeof(*item), GFP_NOFS);
6714d8e8
KH		 2143 if (!item)
2144 return -ENOMEM;
2145
2146
2147 /* queue up work for dlm_assert_master_worker */
2148 dlm_grab(dlm); /* get an extra ref for the work item */
2149 dlm_init_work_item(dlm, item, dlm_assert_master_worker, NULL);
2150 item->u.am.lockres = res; /* already have a ref */
2151 /* can optionally ignore node numbers higher than this node */
2152 item->u.am.ignore_higher = ignore_higher;
2153 item->u.am.request_from = request_from;
2154 item->u.am.flags = flags;
2155
9c6510a5
KH		 2156 if (ignore_higher)
2157 mlog(0, "IGNORE HIGHER: %.*s\n", res->lockname.len,
2158 res->lockname.name);
2159
6714d8e8
KH		 2160 spin_lock(&dlm->work_lock);
2161 list_add_tail(&item->list, &dlm->work_list);
2162 spin_unlock(&dlm->work_lock);
2163
3156d267 2164 queue_work(dlm->dlm_worker, &dlm->dispatched_work);
6714d8e8
KH		 2165 return 0;
2166}
2167
2168static void dlm_assert_master_worker(struct dlm_work_item *item, void *data)
2169{
2170 struct dlm_ctxt *dlm = data;
2171 int ret = 0;
2172 struct dlm_lock_resource *res;
2173 unsigned long nodemap[BITS_TO_LONGS(O2NM_MAX_NODES)];
2174 int ignore_higher;
2175 int bit;
2176 u8 request_from;
2177 u32 flags;
2178
2179 dlm = item->dlm;
2180 res = item->u.am.lockres;
2181 ignore_higher = item->u.am.ignore_higher;
2182 request_from = item->u.am.request_from;
2183 flags = item->u.am.flags;
2184
2185 spin_lock(&dlm->spinlock);
2186 memcpy(nodemap, dlm->domain_map, sizeof(nodemap));
2187 spin_unlock(&dlm->spinlock);
2188
2189 clear_bit(dlm->node_num, nodemap);
2190 if (ignore_higher) {
2191 /* if is this just to clear up mles for nodes below
2192 * this node, do not send the message to the original
2193 * caller or any node number higher than this */
2194 clear_bit(request_from, nodemap);
2195 bit = dlm->node_num;
2196 while (1) {
2197 bit = find_next_bit(nodemap, O2NM_MAX_NODES,
2198 bit+1);
2199 if (bit >= O2NM_MAX_NODES)
2200 break;
2201 clear_bit(bit, nodemap);
2202 }
2203 }
2204
36407488
KH		 2205 /*
2206 * If we're migrating this lock to someone else, we are no
2207 * longer allowed to assert out own mastery. OTOH, we need to
2208 * prevent migration from starting while we're still asserting
2209 * our dominance. The reserved ast delays migration.
2210 */
2211 spin_lock(&res->spinlock);
2212 if (res->state & DLM_LOCK_RES_MIGRATING) {
2213 mlog(0, "Someone asked us to assert mastery, but we're "
2214 "in the middle of migration. Skipping assert, "
2215 "the new master will handle that.\n");
2216 spin_unlock(&res->spinlock);
2217 goto put;
2218 } else
2219 __dlm_lockres_reserve_ast(res);
2220 spin_unlock(&res->spinlock);
2221
6714d8e8
KH		 2222 /* this call now finishes out the nodemap
2223 * even if one or more nodes die */
2224 mlog(0, "worker about to master %.*s here, this=%u\n",
2225 res->lockname.len, res->lockname.name, dlm->node_num);
ba2bf218 2226 ret = dlm_do_assert_master(dlm, res, nodemap, flags);
6714d8e8
KH		 2227 if (ret < 0) {
2228 /* no need to restart, we are done */
3b3b84a8
KH		 2229 if (!dlm_is_host_down(ret))
2230 mlog_errno(ret);
6714d8e8
KH		 2231 }
2232
36407488
KH		 2233 /* Ok, we've asserted ourselves. Let's let migration start. */
2234 dlm_lockres_release_ast(dlm, res);
2235
2236put:
6714d8e8
KH		 2237 dlm_lockres_put(res);
2238
2239 mlog(0, "finished with dlm_assert_master_worker\n");
2240}
2241
c03872f5
KH		 2242/* SPECIAL CASE for the $RECOVERY lock used by the recovery thread.
2243 * We cannot wait for node recovery to complete to begin mastering this
2244 * lockres because this lockres is used to kick off recovery! ;-)
2245 * So, do a pre-check on all living nodes to see if any of those nodes
2246 * think that $RECOVERY is currently mastered by a dead node. If so,
2247 * we wait a short time to allow that node to get notified by its own
2248 * heartbeat stack, then check again. All $RECOVERY lock resources
2249 * mastered by dead nodes are purged when the hearbeat callback is
2250 * fired, so we can know for sure that it is safe to continue once
2251 * the node returns a live node or no node. */
2252static int dlm_pre_master_reco_lockres(struct dlm_ctxt *dlm,
2253 struct dlm_lock_resource *res)
2254{
2255 struct dlm_node_iter iter;
2256 int nodenum;
2257 int ret = 0;
2258 u8 master = DLM_LOCK_RES_OWNER_UNKNOWN;
2259
2260 spin_lock(&dlm->spinlock);
2261 dlm_node_iter_init(dlm->domain_map, &iter);
2262 spin_unlock(&dlm->spinlock);
2263
2264 while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2265 /* do not send to self */
2266 if (nodenum == dlm->node_num)
2267 continue;
2268 ret = dlm_do_master_requery(dlm, res, nodenum, &master);
2269 if (ret < 0) {
2270 mlog_errno(ret);
2271 if (!dlm_is_host_down(ret))
2272 BUG();
2273 /* host is down, so answer for that node would be
2274 * DLM_LOCK_RES_OWNER_UNKNOWN. continue. */
f42a100b 2275 ret = 0;
c03872f5
KH		 2276 }
2277
2278 if (master != DLM_LOCK_RES_OWNER_UNKNOWN) {
2279 /* check to see if this master is in the recovery map */
2280 spin_lock(&dlm->spinlock);
2281 if (test_bit(master, dlm->recovery_map)) {
2282 mlog(ML_NOTICE, "%s: node %u has not seen "
2283 "node %u go down yet, and thinks the "
2284 "dead node is mastering the recovery "
2285 "lock. must wait.\n", dlm->name,
2286 nodenum, master);
2287 ret = -EAGAIN;
2288 }
2289 spin_unlock(&dlm->spinlock);
2290 mlog(0, "%s: reco lock master is %u\n", dlm->name,
2291 master);
2292 break;
2293 }
2294 }
2295 return ret;
2296}
2297
ba2bf218
KH		 2298/*
2299 * DLM_DEREF_LOCKRES_MSG
2300 */
2301
2302int dlm_drop_lockres_ref(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
2303{
2304 struct dlm_deref_lockres deref;
2305 int ret = 0, r;
2306 const char *lockname;
2307 unsigned int namelen;
2308
2309 lockname = res->lockname.name;
2310 namelen = res->lockname.len;
2311 BUG_ON(namelen > O2NM_MAX_NAME_LEN);
2312
2313 mlog(0, "%s:%.*s: sending deref to %d\n",
2314 dlm->name, namelen, lockname, res->owner);
2315 memset(&deref, 0, sizeof(deref));
2316 deref.node_idx = dlm->node_num;
2317 deref.namelen = namelen;
2318 memcpy(deref.name, lockname, namelen);
2319
2320 ret = o2net_send_message(DLM_DEREF_LOCKRES_MSG, dlm->key,
2321 &deref, sizeof(deref), res->owner, &r);
2322 if (ret < 0)
2323 mlog_errno(ret);
2324 else if (r < 0) {
2325 /* BAD. other node says I did not have a ref. */
2326 mlog(ML_ERROR,"while dropping ref on %s:%.*s "
2327 "(master=%u) got %d.\n", dlm->name, namelen,
2328 lockname, res->owner, r);
2329 dlm_print_one_lock_resource(res);
2330 BUG();
2331 }
2332 return ret;
2333}
2334
d74c9803
KH		 2335int dlm_deref_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
2336 void **ret_data)
ba2bf218
KH		 2337{
2338 struct dlm_ctxt *dlm = data;
2339 struct dlm_deref_lockres *deref = (struct dlm_deref_lockres *)msg->buf;
2340 struct dlm_lock_resource *res = NULL;
2341 char *name;
2342 unsigned int namelen;
2343 int ret = -EINVAL;
2344 u8 node;
2345 unsigned int hash;
f3f85464
SM		 2346 struct dlm_work_item *item;
2347 int cleared = 0;
2348 int dispatch = 0;
ba2bf218
KH		 2349
2350 if (!dlm_grab(dlm))
2351 return 0;
2352
2353 name = deref->name;
2354 namelen = deref->namelen;
2355 node = deref->node_idx;
2356
2357 if (namelen > DLM_LOCKID_NAME_MAX) {
2358 mlog(ML_ERROR, "Invalid name length!");
2359 goto done;
2360 }
2361 if (deref->node_idx >= O2NM_MAX_NODES) {
2362 mlog(ML_ERROR, "Invalid node number: %u\n", node);
2363 goto done;
2364 }
2365
2366 hash = dlm_lockid_hash(name, namelen);
2367
2368 spin_lock(&dlm->spinlock);
2369 res = __dlm_lookup_lockres_full(dlm, name, namelen, hash);
2370 if (!res) {
2371 spin_unlock(&dlm->spinlock);
2372 mlog(ML_ERROR, "%s:%.*s: bad lockres name\n",
2373 dlm->name, namelen, name);
2374 goto done;
2375 }
2376 spin_unlock(&dlm->spinlock);
2377
2378 spin_lock(&res->spinlock);
f3f85464
SM		 2379 if (res->state & DLM_LOCK_RES_SETREF_INPROG)
2380 dispatch = 1;
2381 else {
2382 BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF);
2383 if (test_bit(node, res->refmap)) {
2384 dlm_lockres_clear_refmap_bit(node, res);
2385 cleared = 1;
2386 }
ba2bf218
KH		 2387 }
2388 spin_unlock(&res->spinlock);
2389
f3f85464
SM		 2390 if (!dispatch) {
2391 if (cleared)
2392 dlm_lockres_calc_usage(dlm, res);
2393 else {
2394 mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref "
2395 "but it is already dropped!\n", dlm->name,
2396 res->lockname.len, res->lockname.name, node);
2af37ce8 2397 dlm_print_one_lock_resource(res);
f3f85464
SM		 2398 }
2399 ret = 0;
2400 goto done;
2401 }
2402
2403 item = kzalloc(sizeof(*item), GFP_NOFS);
2404 if (!item) {
2405 ret = -ENOMEM;
2406 mlog_errno(ret);
2407 goto done;
2408 }
2409
2410 dlm_init_work_item(dlm, item, dlm_deref_lockres_worker, NULL);
2411 item->u.dl.deref_res = res;
2412 item->u.dl.deref_node = node;
2413
2414 spin_lock(&dlm->work_lock);
2415 list_add_tail(&item->list, &dlm->work_list);
2416 spin_unlock(&dlm->work_lock);
2417
2418 queue_work(dlm->dlm_worker, &dlm->dispatched_work);
2419 return 0;
2420
ba2bf218
KH		 2421done:
2422 if (res)
2423 dlm_lockres_put(res);
2424 dlm_put(dlm);
f3f85464 2425
ba2bf218
KH		 2426 return ret;
2427}
2428
f3f85464
SM		 2429static void dlm_deref_lockres_worker(struct dlm_work_item *item, void *data)
2430{
2431 struct dlm_ctxt *dlm;
2432 struct dlm_lock_resource *res;
2433 u8 node;
2434 u8 cleared = 0;
2435
2436 dlm = item->dlm;
2437 res = item->u.dl.deref_res;
2438 node = item->u.dl.deref_node;
2439
2440 spin_lock(&res->spinlock);
2441 BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF);
2442 if (test_bit(node, res->refmap)) {
2443 __dlm_wait_on_lockres_flags(res, DLM_LOCK_RES_SETREF_INPROG);
2444 dlm_lockres_clear_refmap_bit(node, res);
2445 cleared = 1;
2446 }
2447 spin_unlock(&res->spinlock);
2448
2449 if (cleared) {
2450 mlog(0, "%s:%.*s node %u ref dropped in dispatch\n",
2451 dlm->name, res->lockname.len, res->lockname.name, node);
2452 dlm_lockres_calc_usage(dlm, res);
2453 } else {
2454 mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref "
2455 "but it is already dropped!\n", dlm->name,
2456 res->lockname.len, res->lockname.name, node);
2af37ce8 2457 dlm_print_one_lock_resource(res);
f3f85464
SM		 2458 }
2459
2460 dlm_lockres_put(res);
2461}
2462
2f5bf1f2
SM		 2463/* Checks whether the lockres can be migrated. Returns 0 if yes, < 0
2464 * if not. If 0, numlocks is set to the number of locks in the lockres.
2465 */
2466static int dlm_is_lockres_migrateable(struct dlm_ctxt *dlm,
2467 struct dlm_lock_resource *res,
2468 int *numlocks)
2469{
2470 int ret;
2471 int i;
2472 int count = 0;
800deef3 2473 struct list_head *queue;
2f5bf1f2
SM		 2474 struct dlm_lock *lock;
2475
2476 assert_spin_locked(&res->spinlock);
2477
2478 ret = -EINVAL;
2479 if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
2480 mlog(0, "cannot migrate lockres with unknown owner!\n");
2481 goto leave;
2482 }
2483
2484 if (res->owner != dlm->node_num) {
2485 mlog(0, "cannot migrate lockres this node doesn't own!\n");
2486 goto leave;
2487 }
2488
2489 ret = 0;
2490 queue = &res->granted;
2491 for (i = 0; i < 3; i++) {
800deef3 2492 list_for_each_entry(lock, queue, list) {
2f5bf1f2
SM		 2493 ++count;
2494 if (lock->ml.node == dlm->node_num) {
2495 mlog(0, "found a lock owned by this node still "
2496 "on the %s queue! will not migrate this "
2497 "lockres\n", (i == 0 ? "granted" :
2498 (i == 1 ? "converting" :
2499 "blocked")));
2500 ret = -ENOTEMPTY;
2501 goto leave;
2502 }
2503 }
2504 queue++;
2505 }
2506
2507 *numlocks = count;
2508 mlog(0, "migrateable lockres having %d locks\n", *numlocks);
2509
2510leave:
2511 return ret;
2512}
6714d8e8
KH		 2513
2514/*
2515 * DLM_MIGRATE_LOCKRES
2516 */
2517
2518
faf0ec9f
AB		 2519static int dlm_migrate_lockres(struct dlm_ctxt *dlm,
2520 struct dlm_lock_resource *res,
2521 u8 target)
6714d8e8
KH		 2522{
2523 struct dlm_master_list_entry *mle = NULL;
2524 struct dlm_master_list_entry *oldmle = NULL;
2525 struct dlm_migratable_lockres *mres = NULL;
2f5bf1f2 2526 int ret = 0;
6714d8e8
KH		 2527 const char *name;
2528 unsigned int namelen;
2529 int mle_added = 0;
2f5bf1f2
SM		 2530 int numlocks;
2531 int wake = 0;
6714d8e8
KH		 2532
2533 if (!dlm_grab(dlm))
2534 return -EINVAL;
2535
2536 name = res->lockname.name;
2537 namelen = res->lockname.len;
2538
2539 mlog(0, "migrating %.*s to %u\n", namelen, name, target);
2540
2541 /*
2542 * ensure this lockres is a proper candidate for migration
2543 */
2544 spin_lock(&res->spinlock);
2f5bf1f2
SM		 2545 ret = dlm_is_lockres_migrateable(dlm, res, &numlocks);
2546 if (ret < 0) {
6714d8e8
KH		 2547 spin_unlock(&res->spinlock);
2548 goto leave;
2549 }
6714d8e8
KH		 2550 spin_unlock(&res->spinlock);
2551
2552 /* no work to do */
2f5bf1f2 2553 if (numlocks == 0) {
6714d8e8 2554 mlog(0, "no locks were found on this lockres! done!\n");
6714d8e8
KH		 2555 goto leave;
2556 }
2557
2558 /*
2559 * preallocate up front
2560 * if this fails, abort
2561 */
2562
2563 ret = -ENOMEM;
ad8100e0 2564 mres = (struct dlm_migratable_lockres *) __get_free_page(GFP_NOFS);
6714d8e8
KH		 2565 if (!mres) {
2566 mlog_errno(ret);
2567 goto leave;
2568 }
2569
2570 mle = (struct dlm_master_list_entry *) kmem_cache_alloc(dlm_mle_cache,
ad8100e0 2571 GFP_NOFS);
6714d8e8
KH		 2572 if (!mle) {
2573 mlog_errno(ret);
2574 goto leave;
2575 }
2576 ret = 0;
2577
2578 /*
2579 * find a node to migrate the lockres to
2580 */
2581
2582 mlog(0, "picking a migration node\n");
2583 spin_lock(&dlm->spinlock);
2584 /* pick a new node */
2585 if (!test_bit(target, dlm->domain_map) ||
2586 target >= O2NM_MAX_NODES) {
2587 target = dlm_pick_migration_target(dlm, res);
2588 }
2589 mlog(0, "node %u chosen for migration\n", target);
2590
2591 if (target >= O2NM_MAX_NODES ||
2592 !test_bit(target, dlm->domain_map)) {
2593 /* target chosen is not alive */
2594 ret = -EINVAL;
2595 }
2596
2597 if (ret) {
2598 spin_unlock(&dlm->spinlock);
2599 goto fail;
2600 }
2601
2602 mlog(0, "continuing with target = %u\n", target);
2603
2604 /*
2605 * clear any existing master requests and
2606 * add the migration mle to the list
2607 */
2608 spin_lock(&dlm->master_lock);
2609 ret = dlm_add_migration_mle(dlm, res, mle, &oldmle, name,
2610 namelen, target, dlm->node_num);
2611 spin_unlock(&dlm->master_lock);
2612 spin_unlock(&dlm->spinlock);
2613
2614 if (ret == -EEXIST) {
2615 mlog(0, "another process is already migrating it\n");
2616 goto fail;
2617 }
2618 mle_added = 1;
2619
2620 /*
2621 * set the MIGRATING flag and flush asts
2622 * if we fail after this we need to re-dirty the lockres
2623 */
2624 if (dlm_mark_lockres_migrating(dlm, res, target) < 0) {
2625 mlog(ML_ERROR, "tried to migrate %.*s to %u, but "
2626 "the target went down.\n", res->lockname.len,
2627 res->lockname.name, target);
2628 spin_lock(&res->spinlock);
2629 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 2630 wake = 1;
6714d8e8
KH		 2631 spin_unlock(&res->spinlock);
2632 ret = -EINVAL;
2633 }
2634
2635fail:
2636 if (oldmle) {
2637 /* master is known, detach if not already detached */
2638 dlm_mle_detach_hb_events(dlm, oldmle);
2639 dlm_put_mle(oldmle);
2640 }
2641
2642 if (ret < 0) {
2643 if (mle_added) {
2644 dlm_mle_detach_hb_events(dlm, mle);
2645 dlm_put_mle(mle);
2646 } else if (mle) {
2647 kmem_cache_free(dlm_mle_cache, mle);
2648 }
2649 goto leave;
2650 }
2651
2652 /*
2653 * at this point, we have a migration target, an mle
2654 * in the master list, and the MIGRATING flag set on
2655 * the lockres
2656 */
2657
1cd04dbe
KH		 2658 /* now that remote nodes are spinning on the MIGRATING flag,
2659 * ensure that all assert_master work is flushed. */
2660 flush_workqueue(dlm->dlm_worker);
6714d8e8
KH		 2661
2662 /* get an extra reference on the mle.
2663 * otherwise the assert_master from the new
2664 * master will destroy this.
2665 * also, make sure that all callers of dlm_get_mle
2666 * take both dlm->spinlock and dlm->master_lock */
2667 spin_lock(&dlm->spinlock);
2668 spin_lock(&dlm->master_lock);
a2bf0477 2669 dlm_get_mle_inuse(mle);
6714d8e8
KH		 2670 spin_unlock(&dlm->master_lock);
2671 spin_unlock(&dlm->spinlock);
2672
2673 /* notify new node and send all lock state */
2674 /* call send_one_lockres with migration flag.
2675 * this serves as notice to the target node that a
2676 * migration is starting. */
2677 ret = dlm_send_one_lockres(dlm, res, mres, target,
2678 DLM_MRES_MIGRATION);
2679
2680 if (ret < 0) {
2681 mlog(0, "migration to node %u failed with %d\n",
2682 target, ret);
2683 /* migration failed, detach and clean up mle */
2684 dlm_mle_detach_hb_events(dlm, mle);
2685 dlm_put_mle(mle);
a2bf0477
KH		 2686 dlm_put_mle_inuse(mle);
2687 spin_lock(&res->spinlock);
2688 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 2689 wake = 1;
a2bf0477 2690 spin_unlock(&res->spinlock);
6714d8e8
KH		 2691 goto leave;
2692 }
2693
2694 /* at this point, the target sends a message to all nodes,
2695 * (using dlm_do_migrate_request). this node is skipped since
2696 * we had to put an mle in the list to begin the process. this
2697 * node now waits for target to do an assert master. this node
2698 * will be the last one notified, ensuring that the migration
2699 * is complete everywhere. if the target dies while this is
2700 * going on, some nodes could potentially see the target as the
2701 * master, so it is important that my recovery finds the migration
2702 * mle and sets the master to UNKNONWN. */
2703
2704
2705 /* wait for new node to assert master */
2706 while (1) {
2707 ret = wait_event_interruptible_timeout(mle->wq,
2708 (atomic_read(&mle->woken) == 1),
2709 msecs_to_jiffies(5000));
2710
2711 if (ret >= 0) {
2712 if (atomic_read(&mle->woken) == 1 ||
2713 res->owner == target)
2714 break;
2715
1cd04dbe
KH		 2716 mlog(0, "%s:%.*s: timed out during migration\n",
2717 dlm->name, res->lockname.len, res->lockname.name);
e2faea4c
KH		 2718 /* avoid hang during shutdown when migrating lockres
2719 * to a node which also goes down */
2720 if (dlm_is_node_dead(dlm, target)) {
aa852354
KH		 2721 mlog(0, "%s:%.*s: expected migration "
2722 "target %u is no longer up, restarting\n",
e2faea4c
KH		 2723 dlm->name, res->lockname.len,
2724 res->lockname.name, target);
1cd04dbe
KH		 2725 ret = -EINVAL;
2726 /* migration failed, detach and clean up mle */
2727 dlm_mle_detach_hb_events(dlm, mle);
2728 dlm_put_mle(mle);
2729 dlm_put_mle_inuse(mle);
2730 spin_lock(&res->spinlock);
2731 res->state &= ~DLM_LOCK_RES_MIGRATING;
a6fa3640 2732 wake = 1;
1cd04dbe
KH		 2733 spin_unlock(&res->spinlock);
2734 goto leave;
e2faea4c 2735 }
1cd04dbe
KH		 2736 } else
2737 mlog(0, "%s:%.*s: caught signal during migration\n",
2738 dlm->name, res->lockname.len, res->lockname.name);
6714d8e8
KH		 2739 }
2740
2741 /* all done, set the owner, clear the flag */
2742 spin_lock(&res->spinlock);
2743 dlm_set_lockres_owner(dlm, res, target);
2744 res->state &= ~DLM_LOCK_RES_MIGRATING;
2745 dlm_remove_nonlocal_locks(dlm, res);
2746 spin_unlock(&res->spinlock);
2747 wake_up(&res->wq);
2748
2749 /* master is known, detach if not already detached */
2750 dlm_mle_detach_hb_events(dlm, mle);
a2bf0477 2751 dlm_put_mle_inuse(mle);
6714d8e8
KH		 2752 ret = 0;
2753
2754 dlm_lockres_calc_usage(dlm, res);
2755
2756leave:
2757 /* re-dirty the lockres if we failed */
2758 if (ret < 0)
2759 dlm_kick_thread(dlm, res);
2760
a6fa3640
KH		 2761 /* wake up waiters if the MIGRATING flag got set
2762 * but migration failed */
2763 if (wake)
2764 wake_up(&res->wq);
2765
6714d8e8
KH		 2766 /* TODO: cleanup */
2767 if (mres)
2768 free_page((unsigned long)mres);
2769
2770 dlm_put(dlm);
2771
2772 mlog(0, "returning %d\n", ret);
2773 return ret;
2774}
6714d8e8 2775
ba2bf218
KH		 2776#define DLM_MIGRATION_RETRY_MS 100
2777
2778/* Should be called only after beginning the domain leave process.
2779 * There should not be any remaining locks on nonlocal lock resources,
2780 * and there should be no local locks left on locally mastered resources.
2781 *
2782 * Called with the dlm spinlock held, may drop it to do migration, but
2783 * will re-acquire before exit.
2784 *
2785 * Returns: 1 if dlm->spinlock was dropped/retaken, 0 if never dropped */
2786int dlm_empty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
2787{
2788 int ret;
2789 int lock_dropped = 0;
2f5bf1f2 2790 int numlocks;
ba2bf218 2791
b36c3f84 2792 spin_lock(&res->spinlock);
ba2bf218
KH		 2793 if (res->owner != dlm->node_num) {
2794 if (!__dlm_lockres_unused(res)) {
2795 mlog(ML_ERROR, "%s:%.*s: this node is not master, "
2796 "trying to free this but locks remain\n",
2797 dlm->name, res->lockname.len, res->lockname.name);
2798 }
b36c3f84 2799 spin_unlock(&res->spinlock);
ba2bf218
KH		 2800 goto leave;
2801 }
2f5bf1f2
SM		 2802
2803 /* No need to migrate a lockres having no locks */
2804 ret = dlm_is_lockres_migrateable(dlm, res, &numlocks);
2805 if (ret >= 0 && numlocks == 0) {
2806 spin_unlock(&res->spinlock);
2807 goto leave;
2808 }
b36c3f84 2809 spin_unlock(&res->spinlock);
ba2bf218
KH		 2810
2811 /* Wheee! Migrate lockres here! Will sleep so drop spinlock. */
2812 spin_unlock(&dlm->spinlock);
2813 lock_dropped = 1;
2814 while (1) {
2815 ret = dlm_migrate_lockres(dlm, res, O2NM_MAX_NODES);
2816 if (ret >= 0)
2817 break;
2818 if (ret == -ENOTEMPTY) {
2819 mlog(ML_ERROR, "lockres %.*s still has local locks!\n",
2820 res->lockname.len, res->lockname.name);
2821 BUG();
2822 }
2823
2824 mlog(0, "lockres %.*s: migrate failed, "
2825 "retrying\n", res->lockname.len,
2826 res->lockname.name);
2827 msleep(DLM_MIGRATION_RETRY_MS);
2828 }
2829 spin_lock(&dlm->spinlock);
2830leave:
2831 return lock_dropped;
2832}
2833
6714d8e8
KH		 2834int dlm_lock_basts_flushed(struct dlm_ctxt *dlm, struct dlm_lock *lock)
2835{
2836 int ret;
2837 spin_lock(&dlm->ast_lock);
2838 spin_lock(&lock->spinlock);
2839 ret = (list_empty(&lock->bast_list) && !lock->bast_pending);
2840 spin_unlock(&lock->spinlock);
2841 spin_unlock(&dlm->ast_lock);
2842 return ret;
2843}
2844
2845static int dlm_migration_can_proceed(struct dlm_ctxt *dlm,
2846 struct dlm_lock_resource *res,
2847 u8 mig_target)
2848{
2849 int can_proceed;
2850 spin_lock(&res->spinlock);
2851 can_proceed = !!(res->state & DLM_LOCK_RES_MIGRATING);
2852 spin_unlock(&res->spinlock);
2853
2854 /* target has died, so make the caller break out of the
2855 * wait_event, but caller must recheck the domain_map */
2856 spin_lock(&dlm->spinlock);
2857 if (!test_bit(mig_target, dlm->domain_map))
2858 can_proceed = 1;
2859 spin_unlock(&dlm->spinlock);
2860 return can_proceed;
2861}
2862
faf0ec9f
AB		 2863static int dlm_lockres_is_dirty(struct dlm_ctxt *dlm,
2864 struct dlm_lock_resource *res)
6714d8e8
KH		 2865{
2866 int ret;
2867 spin_lock(&res->spinlock);
2868 ret = !!(res->state & DLM_LOCK_RES_DIRTY);
2869 spin_unlock(&res->spinlock);
2870 return ret;
2871}
2872
2873
2874static int dlm_mark_lockres_migrating(struct dlm_ctxt *dlm,
2875 struct dlm_lock_resource *res,
2876 u8 target)
2877{
2878 int ret = 0;
2879
2880 mlog(0, "dlm_mark_lockres_migrating: %.*s, from %u to %u\n",
2881 res->lockname.len, res->lockname.name, dlm->node_num,
2882 target);
2883 /* need to set MIGRATING flag on lockres. this is done by
2884 * ensuring that all asts have been flushed for this lockres. */
2885 spin_lock(&res->spinlock);
2886 BUG_ON(res->migration_pending);
2887 res->migration_pending = 1;
2888 /* strategy is to reserve an extra ast then release
2889 * it below, letting the release do all of the work */
2890 __dlm_lockres_reserve_ast(res);
2891 spin_unlock(&res->spinlock);
2892
ddc09c8d 2893 /* now flush all the pending asts */
6714d8e8 2894 dlm_kick_thread(dlm, res);
ddc09c8d
KH		 2895 /* before waiting on DIRTY, block processes which may
2896 * try to dirty the lockres before MIGRATING is set */
2897 spin_lock(&res->spinlock);
2898 BUG_ON(res->state & DLM_LOCK_RES_BLOCK_DIRTY);
2899 res->state |= DLM_LOCK_RES_BLOCK_DIRTY;
2900 spin_unlock(&res->spinlock);
2901 /* now wait on any pending asts and the DIRTY state */
6714d8e8
KH		 2902 wait_event(dlm->ast_wq, !dlm_lockres_is_dirty(dlm, res));
2903 dlm_lockres_release_ast(dlm, res);
2904
2905 mlog(0, "about to wait on migration_wq, dirty=%s\n",
2906 res->state & DLM_LOCK_RES_DIRTY ? "yes" : "no");
2907 /* if the extra ref we just put was the final one, this
2908 * will pass thru immediately. otherwise, we need to wait
2909 * for the last ast to finish. */
2910again:
2911 ret = wait_event_interruptible_timeout(dlm->migration_wq,
2912 dlm_migration_can_proceed(dlm, res, target),
2913 msecs_to_jiffies(1000));
2914 if (ret < 0) {
2915 mlog(0, "woken again: migrating? %s, dead? %s\n",
2916 res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no",
2917 test_bit(target, dlm->domain_map) ? "no":"yes");
2918 } else {
2919 mlog(0, "all is well: migrating? %s, dead? %s\n",
2920 res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no",
2921 test_bit(target, dlm->domain_map) ? "no":"yes");
2922 }
2923 if (!dlm_migration_can_proceed(dlm, res, target)) {
2924 mlog(0, "trying again...\n");
2925 goto again;
2926 }
ddc09c8d
KH		 2927 /* now that we are sure the MIGRATING state is there, drop
2928 * the unneded state which blocked threads trying to DIRTY */
2929 spin_lock(&res->spinlock);
2930 BUG_ON(!(res->state & DLM_LOCK_RES_BLOCK_DIRTY));
2931 BUG_ON(!(res->state & DLM_LOCK_RES_MIGRATING));
2932 res->state &= ~DLM_LOCK_RES_BLOCK_DIRTY;
2933 spin_unlock(&res->spinlock);
6714d8e8
KH		 2934
2935 /* did the target go down or die? */
2936 spin_lock(&dlm->spinlock);
2937 if (!test_bit(target, dlm->domain_map)) {
2938 mlog(ML_ERROR, "aha. migration target %u just went down\n",
2939 target);
2940 ret = -EHOSTDOWN;
2941 }
2942 spin_unlock(&dlm->spinlock);
2943
2944 /*
2945 * at this point:
2946 *
2947 * o the DLM_LOCK_RES_MIGRATING flag is set
2948 * o there are no pending asts on this lockres
2949 * o all processes trying to reserve an ast on this
2950 * lockres must wait for the MIGRATING flag to clear
2951 */
2952 return ret;
2953}
2954
2955/* last step in the migration process.
2956 * original master calls this to free all of the dlm_lock
2957 * structures that used to be for other nodes. */
2958static void dlm_remove_nonlocal_locks(struct dlm_ctxt *dlm,
2959 struct dlm_lock_resource *res)
2960{
6714d8e8 2961 struct list_head *queue = &res->granted;
ba2bf218 2962 int i, bit;
800deef3 2963 struct dlm_lock *lock, *next;
6714d8e8
KH		 2964
2965 assert_spin_locked(&res->spinlock);
2966
2967 BUG_ON(res->owner == dlm->node_num);
2968
2969 for (i=0; i<3; i++) {
800deef3 2970 list_for_each_entry_safe(lock, next, queue, list) {
6714d8e8
KH		 2971 if (lock->ml.node != dlm->node_num) {
2972 mlog(0, "putting lock for node %u\n",
2973 lock->ml.node);
2974 /* be extra careful */
2975 BUG_ON(!list_empty(&lock->ast_list));
2976 BUG_ON(!list_empty(&lock->bast_list));
2977 BUG_ON(lock->ast_pending);
2978 BUG_ON(lock->bast_pending);
ba2bf218 2979 dlm_lockres_clear_refmap_bit(lock->ml.node, res);
6714d8e8
KH		 2980 list_del_init(&lock->list);
2981 dlm_lock_put(lock);
2c5c54ac
SM		 2982 /* In a normal unlock, we would have added a
2983 * DLM_UNLOCK_FREE_LOCK action. Force it. */
2984 dlm_lock_put(lock);
6714d8e8
KH		 2985 }
2986 }
2987 queue++;
2988 }
ba2bf218
KH		 2989 bit = 0;
2990 while (1) {
2991 bit = find_next_bit(res->refmap, O2NM_MAX_NODES, bit);
2992 if (bit >= O2NM_MAX_NODES)
2993 break;
2994 /* do not clear the local node reference, if there is a
2995 * process holding this, let it drop the ref itself */
2996 if (bit != dlm->node_num) {
2997 mlog(0, "%s:%.*s: node %u had a ref to this "
2998 "migrating lockres, clearing\n", dlm->name,
2999 res->lockname.len, res->lockname.name, bit);
3000 dlm_lockres_clear_refmap_bit(bit, res);
3001 }
3002 bit++;
3003 }
6714d8e8
KH		 3004}
3005
3006/* for now this is not too intelligent. we will
3007 * need stats to make this do the right thing.
3008 * this just finds the first lock on one of the
3009 * queues and uses that node as the target. */
3010static u8 dlm_pick_migration_target(struct dlm_ctxt *dlm,
3011 struct dlm_lock_resource *res)
3012{
3013 int i;
3014 struct list_head *queue = &res->granted;
6714d8e8
KH		 3015 struct dlm_lock *lock;
3016 int nodenum;
3017
3018 assert_spin_locked(&dlm->spinlock);
3019
3020 spin_lock(&res->spinlock);
3021 for (i=0; i<3; i++) {
800deef3 3022 list_for_each_entry(lock, queue, list) {
6714d8e8
KH		 3023 /* up to the caller to make sure this node
3024 * is alive */
6714d8e8
KH		 3025 if (lock->ml.node != dlm->node_num) {
3026 spin_unlock(&res->spinlock);
3027 return lock->ml.node;
3028 }
3029 }
3030 queue++;
3031 }
3032 spin_unlock(&res->spinlock);
3033 mlog(0, "have not found a suitable target yet! checking domain map\n");
3034
3035 /* ok now we're getting desperate. pick anyone alive. */
3036 nodenum = -1;
3037 while (1) {
3038 nodenum = find_next_bit(dlm->domain_map,
3039 O2NM_MAX_NODES, nodenum+1);
3040 mlog(0, "found %d in domain map\n", nodenum);
3041 if (nodenum >= O2NM_MAX_NODES)
3042 break;
3043 if (nodenum != dlm->node_num) {
3044 mlog(0, "picking %d\n", nodenum);
3045 return nodenum;
3046 }
3047 }
3048
3049 mlog(0, "giving up. no master to migrate to\n");
3050 return DLM_LOCK_RES_OWNER_UNKNOWN;
3051}
3052
3053
3054
3055/* this is called by the new master once all lockres
3056 * data has been received */
3057static int dlm_do_migrate_request(struct dlm_ctxt *dlm,
3058 struct dlm_lock_resource *res,
3059 u8 master, u8 new_master,
3060 struct dlm_node_iter *iter)
3061{
3062 struct dlm_migrate_request migrate;
3063 int ret, status = 0;
3064 int nodenum;
3065
3066 memset(&migrate, 0, sizeof(migrate));
3067 migrate.namelen = res->lockname.len;
3068 memcpy(migrate.name, res->lockname.name, migrate.namelen);
3069 migrate.new_master = new_master;
3070 migrate.master = master;
3071
3072 ret = 0;
3073
3074 /* send message to all nodes, except the master and myself */
3075 while ((nodenum = dlm_node_iter_next(iter)) >= 0) {
3076 if (nodenum == master ||
3077 nodenum == new_master)
3078 continue;
3079
3080 ret = o2net_send_message(DLM_MIGRATE_REQUEST_MSG, dlm->key,
3081 &migrate, sizeof(migrate), nodenum,
3082 &status);
3083 if (ret < 0)
3084 mlog_errno(ret);
3085 else if (status < 0) {
3086 mlog(0, "migrate request (node %u) returned %d!\n",
3087 nodenum, status);
3088 ret = status;
ba2bf218
KH		 3089 } else if (status == DLM_MIGRATE_RESPONSE_MASTERY_REF) {
3090 /* during the migration request we short-circuited
3091 * the mastery of the lockres. make sure we have
3092 * a mastery ref for nodenum */
3093 mlog(0, "%s:%.*s: need ref for node %u\n",
3094 dlm->name, res->lockname.len, res->lockname.name,
3095 nodenum);
3096 spin_lock(&res->spinlock);
3097 dlm_lockres_set_refmap_bit(nodenum, res);
3098 spin_unlock(&res->spinlock);
6714d8e8
KH		 3099 }
3100 }
3101
3102 if (ret < 0)
3103 mlog_errno(ret);
3104
3105 mlog(0, "returning ret=%d\n", ret);
3106 return ret;
3107}
3108
3109
3110/* if there is an existing mle for this lockres, we now know who the master is.
3111 * (the one who sent us *this* message) we can clear it up right away.
3112 * since the process that put the mle on the list still has a reference to it,
3113 * we can unhash it now, set the master and wake the process. as a result,
3114 * we will have no mle in the list to start with. now we can add an mle for
3115 * the migration and this should be the only one found for those scanning the
3116 * list. */
d74c9803
KH		 3117int dlm_migrate_request_handler(struct o2net_msg *msg, u32 len, void *data,
3118 void **ret_data)
6714d8e8
KH		 3119{
3120 struct dlm_ctxt *dlm = data;
3121 struct dlm_lock_resource *res = NULL;
3122 struct dlm_migrate_request *migrate = (struct dlm_migrate_request *) msg->buf;
3123 struct dlm_master_list_entry *mle = NULL, *oldmle = NULL;
3124 const char *name;
a3d33291 3125 unsigned int namelen, hash;
6714d8e8
KH		 3126 int ret = 0;
3127
3128 if (!dlm_grab(dlm))
3129 return -EINVAL;
3130
3131 name = migrate->name;
3132 namelen = migrate->namelen;
a3d33291 3133 hash = dlm_lockid_hash(name, namelen);
6714d8e8
KH		 3134
3135 /* preallocate.. if this fails, abort */
3136 mle = (struct dlm_master_list_entry *) kmem_cache_alloc(dlm_mle_cache,
ad8100e0 3137 GFP_NOFS);
6714d8e8
KH		 3138
3139 if (!mle) {
3140 ret = -ENOMEM;
3141 goto leave;
3142 }
3143
3144 /* check for pre-existing lock */
3145 spin_lock(&dlm->spinlock);
a3d33291 3146 res = __dlm_lookup_lockres(dlm, name, namelen, hash);
6714d8e8
KH		 3147 spin_lock(&dlm->master_lock);
3148
3149 if (res) {
3150 spin_lock(&res->spinlock);
3151 if (res->state & DLM_LOCK_RES_RECOVERING) {
3152 /* if all is working ok, this can only mean that we got
3153 * a migrate request from a node that we now see as
3154 * dead. what can we do here? drop it to the floor? */
3155 spin_unlock(&res->spinlock);
3156 mlog(ML_ERROR, "Got a migrate request, but the "
3157 "lockres is marked as recovering!");
3158 kmem_cache_free(dlm_mle_cache, mle);
3159 ret = -EINVAL; /* need a better solution */
3160 goto unlock;
3161 }
3162 res->state |= DLM_LOCK_RES_MIGRATING;
3163 spin_unlock(&res->spinlock);
3164 }
3165
3166 /* ignore status. only nonzero status would BUG. */
3167 ret = dlm_add_migration_mle(dlm, res, mle, &oldmle,
3168 name, namelen,
3169 migrate->new_master,
3170 migrate->master);
3171
3172unlock:
3173 spin_unlock(&dlm->master_lock);
3174 spin_unlock(&dlm->spinlock);
3175
3176 if (oldmle) {
3177 /* master is known, detach if not already detached */
3178 dlm_mle_detach_hb_events(dlm, oldmle);
3179 dlm_put_mle(oldmle);
3180 }
3181
3182 if (res)
3183 dlm_lockres_put(res);
3184leave:
3185 dlm_put(dlm);
3186 return ret;
3187}
3188
3189/* must be holding dlm->spinlock and dlm->master_lock
3190 * when adding a migration mle, we can clear any other mles
3191 * in the master list because we know with certainty that
3192 * the master is "master". so we remove any old mle from
3193 * the list after setting it's master field, and then add
3194 * the new migration mle. this way we can hold with the rule
3195 * of having only one mle for a given lock name at all times. */
3196static int dlm_add_migration_mle(struct dlm_ctxt *dlm,
3197 struct dlm_lock_resource *res,
3198 struct dlm_master_list_entry *mle,
3199 struct dlm_master_list_entry **oldmle,
3200 const char *name, unsigned int namelen,
3201 u8 new_master, u8 master)
3202{
3203 int found;
3204 int ret = 0;
3205
3206 *oldmle = NULL;
3207
3208 mlog_entry_void();
3209
3210 assert_spin_locked(&dlm->spinlock);
3211 assert_spin_locked(&dlm->master_lock);
3212
3213 /* caller is responsible for any ref taken here on oldmle */
3214 found = dlm_find_mle(dlm, oldmle, (char *)name, namelen);
3215 if (found) {
3216 struct dlm_master_list_entry *tmp = *oldmle;
3217 spin_lock(&tmp->spinlock);
3218 if (tmp->type == DLM_MLE_MIGRATION) {
3219 if (master == dlm->node_num) {
3220 /* ah another process raced me to it */
3221 mlog(0, "tried to migrate %.*s, but some "
3222 "process beat me to it\n",
3223 namelen, name);
3224 ret = -EEXIST;
3225 } else {
3226 /* bad. 2 NODES are trying to migrate! */
3227 mlog(ML_ERROR, "migration error mle: "
3228 "master=%u new_master=%u // request: "
3229 "master=%u new_master=%u // "
3230 "lockres=%.*s\n",
3231 tmp->master, tmp->new_master,
3232 master, new_master,
3233 namelen, name);
3234 BUG();
3235 }
3236 } else {
3237 /* this is essentially what assert_master does */
3238 tmp->master = master;
3239 atomic_set(&tmp->woken, 1);
3240 wake_up(&tmp->wq);
3241 /* remove it from the list so that only one
3242 * mle will be found */
3243 list_del_init(&tmp->list);
ba2bf218
KH		 3244 /* this was obviously WRONG. mle is uninited here. should be tmp. */
3245 __dlm_mle_detach_hb_events(dlm, tmp);
3246 ret = DLM_MIGRATE_RESPONSE_MASTERY_REF;
3247 mlog(0, "%s:%.*s: master=%u, newmaster=%u, "
3248 "telling master to get ref for cleared out mle "
3249 "during migration\n", dlm->name, namelen, name,
3250 master, new_master);
6714d8e8
KH		 3251 }
3252 spin_unlock(&tmp->spinlock);
3253 }
3254
3255 /* now add a migration mle to the tail of the list */
3256 dlm_init_mle(mle, DLM_MLE_MIGRATION, dlm, res, name, namelen);
3257 mle->new_master = new_master;
ba2bf218
KH		 3258 /* the new master will be sending an assert master for this.
3259 * at that point we will get the refmap reference */
6714d8e8
KH		 3260 mle->master = master;
3261 /* do this for consistency with other mle types */
3262 set_bit(new_master, mle->maybe_map);
3263 list_add(&mle->list, &dlm->master_list);
3264
3265 return ret;
3266}
3267
3268
3269void dlm_clean_master_list(struct dlm_ctxt *dlm, u8 dead_node)
3270{
800deef3 3271 struct dlm_master_list_entry *mle, *next;
6714d8e8 3272 struct dlm_lock_resource *res;
a3d33291 3273 unsigned int hash;
6714d8e8
KH		 3274
3275 mlog_entry("dlm=%s, dead node=%u\n", dlm->name, dead_node);
3276top:
3277 assert_spin_locked(&dlm->spinlock);
3278
3279 /* clean the master list */
3280 spin_lock(&dlm->master_lock);
800deef3 3281 list_for_each_entry_safe(mle, next, &dlm->master_list, list) {
6714d8e8
KH		 3282 BUG_ON(mle->type != DLM_MLE_BLOCK &&
3283 mle->type != DLM_MLE_MASTER &&
3284 mle->type != DLM_MLE_MIGRATION);
3285
3286 /* MASTER mles are initiated locally. the waiting
3287 * process will notice the node map change
3288 * shortly. let that happen as normal. */
3289 if (mle->type == DLM_MLE_MASTER)
3290 continue;
3291
3292
3293 /* BLOCK mles are initiated by other nodes.
3294 * need to clean up if the dead node would have
3295 * been the master. */
3296 if (mle->type == DLM_MLE_BLOCK) {
3297 int bit;
3298
3299 spin_lock(&mle->spinlock);
3300 bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0);
3301 if (bit != dead_node) {
3302 mlog(0, "mle found, but dead node %u would "
3303 "not have been master\n", dead_node);
3304 spin_unlock(&mle->spinlock);
3305 } else {
3306 /* must drop the refcount by one since the
3307 * assert_master will never arrive. this
3308 * may result in the mle being unlinked and
3309 * freed, but there may still be a process
3310 * waiting in the dlmlock path which is fine. */
3b3b84a8 3311 mlog(0, "node %u was expected master\n",
6714d8e8
KH		 3312 dead_node);
3313 atomic_set(&mle->woken, 1);
3314 spin_unlock(&mle->spinlock);
3315 wake_up(&mle->wq);
f671c09b
KH		 3316 /* do not need events any longer, so detach
3317 * from heartbeat */
3318 __dlm_mle_detach_hb_events(dlm, mle);
6714d8e8
KH		 3319 __dlm_put_mle(mle);
3320 }
3321 continue;
3322 }
3323
3324 /* everything else is a MIGRATION mle */
3325
3326 /* the rule for MIGRATION mles is that the master
3327 * becomes UNKNOWN if *either* the original or
3328 * the new master dies. all UNKNOWN lockreses
3329 * are sent to whichever node becomes the recovery
3330 * master. the new master is responsible for
3331 * determining if there is still a master for
3332 * this lockres, or if he needs to take over
3333 * mastery. either way, this node should expect
3334 * another message to resolve this. */
3335 if (mle->master != dead_node &&
3336 mle->new_master != dead_node)
3337 continue;
3338
3339 /* if we have reached this point, this mle needs to
3340 * be removed from the list and freed. */
3341
3342 /* remove from the list early. NOTE: unlinking
3343 * list_head while in list_for_each_safe */
da01ad05 3344 __dlm_mle_detach_hb_events(dlm, mle);
6714d8e8
KH		 3345 spin_lock(&mle->spinlock);
3346 list_del_init(&mle->list);
3347 atomic_set(&mle->woken, 1);
3348 spin_unlock(&mle->spinlock);
3349 wake_up(&mle->wq);
3350
aa852354
KH		 3351 mlog(0, "%s: node %u died during migration from "
3352 "%u to %u!\n", dlm->name, dead_node,
6714d8e8
KH		 3353 mle->master, mle->new_master);
3354 /* if there is a lockres associated with this
3355 * mle, find it and set its owner to UNKNOWN */
a3d33291 3356 hash = dlm_lockid_hash(mle->u.name.name, mle->u.name.len);
6714d8e8 3357 res = __dlm_lookup_lockres(dlm, mle->u.name.name,
a3d33291 3358 mle->u.name.len, hash);
6714d8e8
KH		 3359 if (res) {
3360 /* unfortunately if we hit this rare case, our
3361 * lock ordering is messed. we need to drop
3362 * the master lock so that we can take the
3363 * lockres lock, meaning that we will have to
3364 * restart from the head of list. */
3365 spin_unlock(&dlm->master_lock);
3366
3367 /* move lockres onto recovery list */
3368 spin_lock(&res->spinlock);
3369 dlm_set_lockres_owner(dlm, res,
3370 DLM_LOCK_RES_OWNER_UNKNOWN);
3371 dlm_move_lockres_to_recovery_list(dlm, res);
3372 spin_unlock(&res->spinlock);
3373 dlm_lockres_put(res);
3374
f671c09b
KH		 3375 /* about to get rid of mle, detach from heartbeat */
3376 __dlm_mle_detach_hb_events(dlm, mle);
3377
6714d8e8
KH		 3378 /* dump the mle */
3379 spin_lock(&dlm->master_lock);
3380 __dlm_put_mle(mle);
3381 spin_unlock(&dlm->master_lock);
3382
3383 /* restart */
3384 goto top;
3385 }
3386
3387 /* this may be the last reference */
3388 __dlm_put_mle(mle);
3389 }
3390 spin_unlock(&dlm->master_lock);
3391}
3392
3393
3394int dlm_finish_migration(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
3395 u8 old_master)
3396{
3397 struct dlm_node_iter iter;
3398 int ret = 0;
3399
3400 spin_lock(&dlm->spinlock);
3401 dlm_node_iter_init(dlm->domain_map, &iter);
3402 clear_bit(old_master, iter.node_map);
3403 clear_bit(dlm->node_num, iter.node_map);
3404 spin_unlock(&dlm->spinlock);
3405
ba2bf218
KH		 3406 /* ownership of the lockres is changing. account for the
3407 * mastery reference here since old_master will briefly have
3408 * a reference after the migration completes */
3409 spin_lock(&res->spinlock);
3410 dlm_lockres_set_refmap_bit(old_master, res);
3411 spin_unlock(&res->spinlock);
3412
6714d8e8
KH		 3413 mlog(0, "now time to do a migrate request to other nodes\n");
3414 ret = dlm_do_migrate_request(dlm, res, old_master,
3415 dlm->node_num, &iter);
3416 if (ret < 0) {
3417 mlog_errno(ret);
3418 goto leave;
3419 }
3420
3421 mlog(0, "doing assert master of %.*s to all except the original node\n",
3422 res->lockname.len, res->lockname.name);
3423 /* this call now finishes out the nodemap
3424 * even if one or more nodes die */
ba2bf218 3425 ret = dlm_do_assert_master(dlm, res, iter.node_map,
6714d8e8
KH		 3426 DLM_ASSERT_MASTER_FINISH_MIGRATION);
3427 if (ret < 0) {
3428 /* no longer need to retry. all living nodes contacted. */
3429 mlog_errno(ret);
3430 ret = 0;
3431 }
3432
3433 memset(iter.node_map, 0, sizeof(iter.node_map));
3434 set_bit(old_master, iter.node_map);
3435 mlog(0, "doing assert master of %.*s back to %u\n",
3436 res->lockname.len, res->lockname.name, old_master);
ba2bf218 3437 ret = dlm_do_assert_master(dlm, res, iter.node_map,
6714d8e8
KH		 3438 DLM_ASSERT_MASTER_FINISH_MIGRATION);
3439 if (ret < 0) {
3440 mlog(0, "assert master to original master failed "
3441 "with %d.\n", ret);
3442 /* the only nonzero status here would be because of
3443 * a dead original node. we're done. */
3444 ret = 0;
3445 }
3446
3447 /* all done, set the owner, clear the flag */
3448 spin_lock(&res->spinlock);
3449 dlm_set_lockres_owner(dlm, res, dlm->node_num);
3450 res->state &= ~DLM_LOCK_RES_MIGRATING;
3451 spin_unlock(&res->spinlock);
3452 /* re-dirty it on the new master */
3453 dlm_kick_thread(dlm, res);
3454 wake_up(&res->wq);
3455leave:
3456 return ret;
3457}
3458
3459/*
3460 * LOCKRES AST REFCOUNT
3461 * this is integral to migration
3462 */
3463
3464/* for future intent to call an ast, reserve one ahead of time.
3465 * this should be called only after waiting on the lockres
3466 * with dlm_wait_on_lockres, and while still holding the
3467 * spinlock after the call. */
3468void __dlm_lockres_reserve_ast(struct dlm_lock_resource *res)
3469{
3470 assert_spin_locked(&res->spinlock);
3471 if (res->state & DLM_LOCK_RES_MIGRATING) {
3472 __dlm_print_one_lock_resource(res);
3473 }
3474 BUG_ON(res->state & DLM_LOCK_RES_MIGRATING);
3475
3476 atomic_inc(&res->asts_reserved);
3477}
3478
3479/*
3480 * used to drop the reserved ast, either because it went unused,
3481 * or because the ast/bast was actually called.
3482 *
3483 * also, if there is a pending migration on this lockres,
3484 * and this was the last pending ast on the lockres,
3485 * atomically set the MIGRATING flag before we drop the lock.
3486 * this is how we ensure that migration can proceed with no
3487 * asts in progress. note that it is ok if the state of the
3488 * queues is such that a lock should be granted in the future
3489 * or that a bast should be fired, because the new master will
3490 * shuffle the lists on this lockres as soon as it is migrated.
3491 */
3492void dlm_lockres_release_ast(struct dlm_ctxt *dlm,
3493 struct dlm_lock_resource *res)
3494{
3495 if (!atomic_dec_and_lock(&res->asts_reserved, &res->spinlock))
3496 return;
3497
3498 if (!res->migration_pending) {
3499 spin_unlock(&res->spinlock);
3500 return;
3501 }
3502
3503 BUG_ON(res->state & DLM_LOCK_RES_MIGRATING);
3504 res->migration_pending = 0;
3505 res->state |= DLM_LOCK_RES_MIGRATING;
3506 spin_unlock(&res->spinlock);
3507 wake_up(&res->wq);
3508 wake_up(&dlm->migration_wq);
3509}
Linux 6.x block layer and io_uring tree(s)