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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * dlmlock.c
4 *
5 * underlying calls for lock creation
6 *
7 * Copyright (C) 2004 Oracle. All rights reserved.
8 */
9
10
11#include <linux/module.h>
12#include <linux/fs.h>
13#include <linux/types.h>
14#include <linux/slab.h>
15#include <linux/highmem.h>
16#include <linux/init.h>
17#include <linux/sysctl.h>
18#include <linux/random.h>
19#include <linux/blkdev.h>
20#include <linux/socket.h>
21#include <linux/inet.h>
22#include <linux/spinlock.h>
23#include <linux/delay.h>
24
25
26#include "../cluster/heartbeat.h"
27#include "../cluster/nodemanager.h"
28#include "../cluster/tcp.h"
29
30#include "dlmapi.h"
31#include "dlmcommon.h"
32
33#include "dlmconvert.h"
34
35#define MLOG_MASK_PREFIX ML_DLM
36#include "../cluster/masklog.h"
37
38static struct kmem_cache *dlm_lock_cache;
39
40static DEFINE_SPINLOCK(dlm_cookie_lock);
41static u64 dlm_next_cookie = 1;
42
43static enum dlm_status dlm_send_remote_lock_request(struct dlm_ctxt *dlm,
44 struct dlm_lock_resource *res,
45 struct dlm_lock *lock, int flags);
46static void dlm_init_lock(struct dlm_lock *newlock, int type,
47 u8 node, u64 cookie);
48static void dlm_lock_release(struct kref *kref);
49static void dlm_lock_detach_lockres(struct dlm_lock *lock);
50
51int dlm_init_lock_cache(void)
52{
53 dlm_lock_cache = kmem_cache_create("o2dlm_lock",
54 sizeof(struct dlm_lock),
55 0, SLAB_HWCACHE_ALIGN, NULL);
56 if (dlm_lock_cache == NULL)
57 return -ENOMEM;
58 return 0;
59}
60
61void dlm_destroy_lock_cache(void)
62{
63 kmem_cache_destroy(dlm_lock_cache);
64}
65
66/* Tell us whether we can grant a new lock request.
67 * locking:
68 * caller needs: res->spinlock
69 * taken: none
70 * held on exit: none
71 * returns: 1 if the lock can be granted, 0 otherwise.
72 */
73static int dlm_can_grant_new_lock(struct dlm_lock_resource *res,
74 struct dlm_lock *lock)
75{
76 struct dlm_lock *tmplock;
77
78 list_for_each_entry(tmplock, &res->granted, list) {
79 if (!dlm_lock_compatible(tmplock->ml.type, lock->ml.type))
80 return 0;
81 }
82
83 list_for_each_entry(tmplock, &res->converting, list) {
84 if (!dlm_lock_compatible(tmplock->ml.type, lock->ml.type))
85 return 0;
86 if (!dlm_lock_compatible(tmplock->ml.convert_type,
87 lock->ml.type))
88 return 0;
89 }
90
91 return 1;
92}
93
94/* performs lock creation at the lockres master site
95 * locking:
96 * caller needs: none
97 * taken: takes and drops res->spinlock
98 * held on exit: none
99 * returns: DLM_NORMAL, DLM_NOTQUEUED
100 */
101static enum dlm_status dlmlock_master(struct dlm_ctxt *dlm,
102 struct dlm_lock_resource *res,
103 struct dlm_lock *lock, int flags)
104{
105 int call_ast = 0, kick_thread = 0;
106 enum dlm_status status = DLM_NORMAL;
107
108 mlog(0, "type=%d\n", lock->ml.type);
109
110 spin_lock(&res->spinlock);
111 /* if called from dlm_create_lock_handler, need to
112 * ensure it will not sleep in dlm_wait_on_lockres */
113 status = __dlm_lockres_state_to_status(res);
114 if (status != DLM_NORMAL &&
115 lock->ml.node != dlm->node_num) {
116 /* erf. state changed after lock was dropped. */
117 spin_unlock(&res->spinlock);
118 dlm_error(status);
119 return status;
120 }
121 __dlm_wait_on_lockres(res);
122 __dlm_lockres_reserve_ast(res);
123
124 if (dlm_can_grant_new_lock(res, lock)) {
125 mlog(0, "I can grant this lock right away\n");
126 /* got it right away */
127 lock->lksb->status = DLM_NORMAL;
128 status = DLM_NORMAL;
129 dlm_lock_get(lock);
130 list_add_tail(&lock->list, &res->granted);
131
132 /* for the recovery lock, we can't allow the ast
133 * to be queued since the dlmthread is already
134 * frozen. but the recovery lock is always locked
135 * with LKM_NOQUEUE so we do not need the ast in
136 * this special case */
137 if (!dlm_is_recovery_lock(res->lockname.name,
138 res->lockname.len)) {
139 kick_thread = 1;
140 call_ast = 1;
141 } else {
142 mlog(0, "%s: returning DLM_NORMAL to "
143 "node %u for reco lock\n", dlm->name,
144 lock->ml.node);
145 }
146 } else {
147 /* for NOQUEUE request, unless we get the
148 * lock right away, return DLM_NOTQUEUED */
149 if (flags & LKM_NOQUEUE) {
150 status = DLM_NOTQUEUED;
151 if (dlm_is_recovery_lock(res->lockname.name,
152 res->lockname.len)) {
153 mlog(0, "%s: returning NOTQUEUED to "
154 "node %u for reco lock\n", dlm->name,
155 lock->ml.node);
156 }
157 } else {
158 status = DLM_NORMAL;
159 dlm_lock_get(lock);
160 list_add_tail(&lock->list, &res->blocked);
161 kick_thread = 1;
162 }
163 }
164
165 spin_unlock(&res->spinlock);
166 wake_up(&res->wq);
167
168 /* either queue the ast or release it */
169 if (call_ast)
170 dlm_queue_ast(dlm, lock);
171 else
172 dlm_lockres_release_ast(dlm, res);
173
174 dlm_lockres_calc_usage(dlm, res);
175 if (kick_thread)
176 dlm_kick_thread(dlm, res);
177
178 return status;
179}
180
181void dlm_revert_pending_lock(struct dlm_lock_resource *res,
182 struct dlm_lock *lock)
183{
184 /* remove from local queue if it failed */
185 list_del_init(&lock->list);
186 lock->lksb->flags &= ~DLM_LKSB_GET_LVB;
187}
188
189
190/*
191 * locking:
192 * caller needs: none
193 * taken: takes and drops res->spinlock
194 * held on exit: none
195 * returns: DLM_DENIED, DLM_RECOVERING, or net status
196 */
197static enum dlm_status dlmlock_remote(struct dlm_ctxt *dlm,
198 struct dlm_lock_resource *res,
199 struct dlm_lock *lock, int flags)
200{
201 enum dlm_status status = DLM_DENIED;
202 int lockres_changed = 1;
203
204 mlog(0, "type=%d, lockres %.*s, flags = 0x%x\n",
205 lock->ml.type, res->lockname.len,
206 res->lockname.name, flags);
207
208 /*
209 * Wait if resource is getting recovered, remastered, etc.
210 * If the resource was remastered and new owner is self, then exit.
211 */
212 spin_lock(&res->spinlock);
213 __dlm_wait_on_lockres(res);
214 if (res->owner == dlm->node_num) {
215 spin_unlock(&res->spinlock);
216 return DLM_RECOVERING;
217 }
218 res->state |= DLM_LOCK_RES_IN_PROGRESS;
219
220 /* add lock to local (secondary) queue */
221 dlm_lock_get(lock);
222 list_add_tail(&lock->list, &res->blocked);
223 lock->lock_pending = 1;
224 spin_unlock(&res->spinlock);
225
226 /* spec seems to say that you will get DLM_NORMAL when the lock
227 * has been queued, meaning we need to wait for a reply here. */
228 status = dlm_send_remote_lock_request(dlm, res, lock, flags);
229
230 spin_lock(&res->spinlock);
231 res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
232 lock->lock_pending = 0;
233 if (status != DLM_NORMAL) {
234 if (status == DLM_RECOVERING &&
235 dlm_is_recovery_lock(res->lockname.name,
236 res->lockname.len)) {
237 /* recovery lock was mastered by dead node.
238 * we need to have calc_usage shoot down this
239 * lockres and completely remaster it. */
240 mlog(0, "%s: recovery lock was owned by "
241 "dead node %u, remaster it now.\n",
242 dlm->name, res->owner);
243 } else if (status != DLM_NOTQUEUED) {
244 /*
245 * DO NOT call calc_usage, as this would unhash
246 * the remote lockres before we ever get to use
247 * it. treat as if we never made any change to
248 * the lockres.
249 */
250 lockres_changed = 0;
251 dlm_error(status);
252 }
253 dlm_revert_pending_lock(res, lock);
254 dlm_lock_put(lock);
255 } else if (dlm_is_recovery_lock(res->lockname.name,
256 res->lockname.len)) {
257 /* special case for the $RECOVERY lock.
258 * there will never be an AST delivered to put
259 * this lock on the proper secondary queue
260 * (granted), so do it manually. */
261 mlog(0, "%s: $RECOVERY lock for this node (%u) is "
262 "mastered by %u; got lock, manually granting (no ast)\n",
263 dlm->name, dlm->node_num, res->owner);
264 list_move_tail(&lock->list, &res->granted);
265 }
266 spin_unlock(&res->spinlock);
267
268 if (lockres_changed)
269 dlm_lockres_calc_usage(dlm, res);
270
271 wake_up(&res->wq);
272 return status;
273}
274
275
276/* for remote lock creation.
277 * locking:
278 * caller needs: none, but need res->state & DLM_LOCK_RES_IN_PROGRESS
279 * taken: none
280 * held on exit: none
281 * returns: DLM_NOLOCKMGR, or net status
282 */
283static enum dlm_status dlm_send_remote_lock_request(struct dlm_ctxt *dlm,
284 struct dlm_lock_resource *res,
285 struct dlm_lock *lock, int flags)
286{
287 struct dlm_create_lock create;
288 int tmpret, status = 0;
289 enum dlm_status ret;
290
291 memset(&create, 0, sizeof(create));
292 create.node_idx = dlm->node_num;
293 create.requested_type = lock->ml.type;
294 create.cookie = lock->ml.cookie;
295 create.namelen = res->lockname.len;
296 create.flags = cpu_to_be32(flags);
297 memcpy(create.name, res->lockname.name, create.namelen);
298
299 tmpret = o2net_send_message(DLM_CREATE_LOCK_MSG, dlm->key, &create,
300 sizeof(create), res->owner, &status);
301 if (tmpret >= 0) {
302 ret = status;
303 if (ret == DLM_REJECTED) {
304 mlog(ML_ERROR, "%s: res %.*s, Stale lockres no longer "
305 "owned by node %u. That node is coming back up "
306 "currently.\n", dlm->name, create.namelen,
307 create.name, res->owner);
308 dlm_print_one_lock_resource(res);
309 BUG();
310 }
311 } else {
312 mlog(ML_ERROR, "%s: res %.*s, Error %d send CREATE LOCK to "
313 "node %u\n", dlm->name, create.namelen, create.name,
314 tmpret, res->owner);
315 if (dlm_is_host_down(tmpret))
316 ret = DLM_RECOVERING;
317 else
318 ret = dlm_err_to_dlm_status(tmpret);
319 }
320
321 return ret;
322}
323
324void dlm_lock_get(struct dlm_lock *lock)
325{
326 kref_get(&lock->lock_refs);
327}
328
329void dlm_lock_put(struct dlm_lock *lock)
330{
331 kref_put(&lock->lock_refs, dlm_lock_release);
332}
333
334static void dlm_lock_release(struct kref *kref)
335{
336 struct dlm_lock *lock;
337
338 lock = container_of(kref, struct dlm_lock, lock_refs);
339
340 BUG_ON(!list_empty(&lock->list));
341 BUG_ON(!list_empty(&lock->ast_list));
342 BUG_ON(!list_empty(&lock->bast_list));
343 BUG_ON(lock->ast_pending);
344 BUG_ON(lock->bast_pending);
345
346 dlm_lock_detach_lockres(lock);
347
348 if (lock->lksb_kernel_allocated) {
349 mlog(0, "freeing kernel-allocated lksb\n");
350 kfree(lock->lksb);
351 }
352 kmem_cache_free(dlm_lock_cache, lock);
353}
354
355/* associate a lock with it's lockres, getting a ref on the lockres */
356void dlm_lock_attach_lockres(struct dlm_lock *lock,
357 struct dlm_lock_resource *res)
358{
359 dlm_lockres_get(res);
360 lock->lockres = res;
361}
362
363/* drop ref on lockres, if there is still one associated with lock */
364static void dlm_lock_detach_lockres(struct dlm_lock *lock)
365{
366 struct dlm_lock_resource *res;
367
368 res = lock->lockres;
369 if (res) {
370 lock->lockres = NULL;
371 mlog(0, "removing lock's lockres reference\n");
372 dlm_lockres_put(res);
373 }
374}
375
376static void dlm_init_lock(struct dlm_lock *newlock, int type,
377 u8 node, u64 cookie)
378{
379 INIT_LIST_HEAD(&newlock->list);
380 INIT_LIST_HEAD(&newlock->ast_list);
381 INIT_LIST_HEAD(&newlock->bast_list);
382 spin_lock_init(&newlock->spinlock);
383 newlock->ml.type = type;
384 newlock->ml.convert_type = LKM_IVMODE;
385 newlock->ml.highest_blocked = LKM_IVMODE;
386 newlock->ml.node = node;
387 newlock->ml.pad1 = 0;
388 newlock->ml.list = 0;
389 newlock->ml.flags = 0;
390 newlock->ast = NULL;
391 newlock->bast = NULL;
392 newlock->astdata = NULL;
393 newlock->ml.cookie = cpu_to_be64(cookie);
394 newlock->ast_pending = 0;
395 newlock->bast_pending = 0;
396 newlock->convert_pending = 0;
397 newlock->lock_pending = 0;
398 newlock->unlock_pending = 0;
399 newlock->cancel_pending = 0;
400 newlock->lksb_kernel_allocated = 0;
401
402 kref_init(&newlock->lock_refs);
403}
404
405struct dlm_lock * dlm_new_lock(int type, u8 node, u64 cookie,
406 struct dlm_lockstatus *lksb)
407{
408 struct dlm_lock *lock;
409 int kernel_allocated = 0;
410
411 lock = kmem_cache_zalloc(dlm_lock_cache, GFP_NOFS);
412 if (!lock)
413 return NULL;
414
415 if (!lksb) {
416 /* zero memory only if kernel-allocated */
417 lksb = kzalloc(sizeof(*lksb), GFP_NOFS);
418 if (!lksb) {
419 kmem_cache_free(dlm_lock_cache, lock);
420 return NULL;
421 }
422 kernel_allocated = 1;
423 }
424
425 dlm_init_lock(lock, type, node, cookie);
426 if (kernel_allocated)
427 lock->lksb_kernel_allocated = 1;
428 lock->lksb = lksb;
429 lksb->lockid = lock;
430 return lock;
431}
432
433/* handler for lock creation net message
434 * locking:
435 * caller needs: none
436 * taken: takes and drops res->spinlock
437 * held on exit: none
438 * returns: DLM_NORMAL, DLM_SYSERR, DLM_IVLOCKID, DLM_NOTQUEUED
439 */
440int dlm_create_lock_handler(struct o2net_msg *msg, u32 len, void *data,
441 void **ret_data)
442{
443 struct dlm_ctxt *dlm = data;
444 struct dlm_create_lock *create = (struct dlm_create_lock *)msg->buf;
445 struct dlm_lock_resource *res = NULL;
446 struct dlm_lock *newlock = NULL;
447 struct dlm_lockstatus *lksb = NULL;
448 enum dlm_status status = DLM_NORMAL;
449 char *name;
450 unsigned int namelen;
451
452 BUG_ON(!dlm);
453
454 if (!dlm_grab(dlm))
455 return DLM_REJECTED;
456
457 name = create->name;
458 namelen = create->namelen;
459 status = DLM_REJECTED;
460 if (!dlm_domain_fully_joined(dlm)) {
461 mlog(ML_ERROR, "Domain %s not fully joined, but node %u is "
462 "sending a create_lock message for lock %.*s!\n",
463 dlm->name, create->node_idx, namelen, name);
464 dlm_error(status);
465 goto leave;
466 }
467
468 status = DLM_IVBUFLEN;
469 if (namelen > DLM_LOCKID_NAME_MAX) {
470 dlm_error(status);
471 goto leave;
472 }
473
474 status = DLM_SYSERR;
475 newlock = dlm_new_lock(create->requested_type,
476 create->node_idx,
477 be64_to_cpu(create->cookie), NULL);
478 if (!newlock) {
479 dlm_error(status);
480 goto leave;
481 }
482
483 lksb = newlock->lksb;
484
485 if (be32_to_cpu(create->flags) & LKM_GET_LVB) {
486 lksb->flags |= DLM_LKSB_GET_LVB;
487 mlog(0, "set DLM_LKSB_GET_LVB flag\n");
488 }
489
490 status = DLM_IVLOCKID;
491 res = dlm_lookup_lockres(dlm, name, namelen);
492 if (!res) {
493 dlm_error(status);
494 goto leave;
495 }
496
497 spin_lock(&res->spinlock);
498 status = __dlm_lockres_state_to_status(res);
499 spin_unlock(&res->spinlock);
500
501 if (status != DLM_NORMAL) {
502 mlog(0, "lockres recovering/migrating/in-progress\n");
503 goto leave;
504 }
505
506 dlm_lock_attach_lockres(newlock, res);
507
508 status = dlmlock_master(dlm, res, newlock, be32_to_cpu(create->flags));
509leave:
510 if (status != DLM_NORMAL)
511 if (newlock)
512 dlm_lock_put(newlock);
513
514 if (res)
515 dlm_lockres_put(res);
516
517 dlm_put(dlm);
518
519 return status;
520}
521
522
523/* fetch next node-local (u8 nodenum + u56 cookie) into u64 */
524static inline void dlm_get_next_cookie(u8 node_num, u64 *cookie)
525{
526 u64 tmpnode = node_num;
527
528 /* shift single byte of node num into top 8 bits */
529 tmpnode <<= 56;
530
531 spin_lock(&dlm_cookie_lock);
532 *cookie = (dlm_next_cookie | tmpnode);
533 if (++dlm_next_cookie & 0xff00000000000000ull) {
534 mlog(0, "This node's cookie will now wrap!\n");
535 dlm_next_cookie = 1;
536 }
537 spin_unlock(&dlm_cookie_lock);
538}
539
540enum dlm_status dlmlock(struct dlm_ctxt *dlm, int mode,
541 struct dlm_lockstatus *lksb, int flags,
542 const char *name, int namelen, dlm_astlockfunc_t *ast,
543 void *data, dlm_bastlockfunc_t *bast)
544{
545 enum dlm_status status;
546 struct dlm_lock_resource *res = NULL;
547 struct dlm_lock *lock = NULL;
548 int convert = 0, recovery = 0;
549
550 /* yes this function is a mess.
551 * TODO: clean this up. lots of common code in the
552 * lock and convert paths, especially in the retry blocks */
553 if (!lksb) {
554 dlm_error(DLM_BADARGS);
555 return DLM_BADARGS;
556 }
557
558 status = DLM_BADPARAM;
559 if (mode != LKM_EXMODE && mode != LKM_PRMODE && mode != LKM_NLMODE) {
560 dlm_error(status);
561 goto error;
562 }
563
564 if (flags & ~LKM_VALID_FLAGS) {
565 dlm_error(status);
566 goto error;
567 }
568
569 convert = (flags & LKM_CONVERT);
570 recovery = (flags & LKM_RECOVERY);
571
572 if (recovery &&
573 (!dlm_is_recovery_lock(name, namelen) || convert) ) {
574 dlm_error(status);
575 goto error;
576 }
577 if (convert && (flags & LKM_LOCAL)) {
578 mlog(ML_ERROR, "strange LOCAL convert request!\n");
579 goto error;
580 }
581
582 if (convert) {
583 /* CONVERT request */
584
585 /* if converting, must pass in a valid dlm_lock */
586 lock = lksb->lockid;
587 if (!lock) {
588 mlog(ML_ERROR, "NULL lock pointer in convert "
589 "request\n");
590 goto error;
591 }
592
593 res = lock->lockres;
594 if (!res) {
595 mlog(ML_ERROR, "NULL lockres pointer in convert "
596 "request\n");
597 goto error;
598 }
599 dlm_lockres_get(res);
600
601 /* XXX: for ocfs2 purposes, the ast/bast/astdata/lksb are
602 * static after the original lock call. convert requests will
603 * ensure that everything is the same, or return DLM_BADARGS.
604 * this means that DLM_DENIED_NOASTS will never be returned.
605 */
606 if (lock->lksb != lksb || lock->ast != ast ||
607 lock->bast != bast || lock->astdata != data) {
608 status = DLM_BADARGS;
609 mlog(ML_ERROR, "new args: lksb=%p, ast=%p, bast=%p, "
610 "astdata=%p\n", lksb, ast, bast, data);
611 mlog(ML_ERROR, "orig args: lksb=%p, ast=%p, bast=%p, "
612 "astdata=%p\n", lock->lksb, lock->ast,
613 lock->bast, lock->astdata);
614 goto error;
615 }
616retry_convert:
617 dlm_wait_for_recovery(dlm);
618
619 if (res->owner == dlm->node_num)
620 status = dlmconvert_master(dlm, res, lock, flags, mode);
621 else
622 status = dlmconvert_remote(dlm, res, lock, flags, mode);
623 if (status == DLM_RECOVERING || status == DLM_MIGRATING ||
624 status == DLM_FORWARD) {
625 /* for now, see how this works without sleeping
626 * and just retry right away. I suspect the reco
627 * or migration will complete fast enough that
628 * no waiting will be necessary */
629 mlog(0, "retrying convert with migration/recovery/"
630 "in-progress\n");
631 msleep(100);
632 goto retry_convert;
633 }
634 } else {
635 u64 tmpcookie;
636
637 /* LOCK request */
638 status = DLM_BADARGS;
639 if (!name) {
640 dlm_error(status);
641 goto error;
642 }
643
644 status = DLM_IVBUFLEN;
645 if (namelen > DLM_LOCKID_NAME_MAX || namelen < 1) {
646 dlm_error(status);
647 goto error;
648 }
649
650 dlm_get_next_cookie(dlm->node_num, &tmpcookie);
651 lock = dlm_new_lock(mode, dlm->node_num, tmpcookie, lksb);
652 if (!lock) {
653 dlm_error(status);
654 goto error;
655 }
656
657 if (!recovery)
658 dlm_wait_for_recovery(dlm);
659
660 /* find or create the lock resource */
661 res = dlm_get_lock_resource(dlm, name, namelen, flags);
662 if (!res) {
663 status = DLM_IVLOCKID;
664 dlm_error(status);
665 goto error;
666 }
667
668 mlog(0, "type=%d, flags = 0x%x\n", mode, flags);
669 mlog(0, "creating lock: lock=%p res=%p\n", lock, res);
670
671 dlm_lock_attach_lockres(lock, res);
672 lock->ast = ast;
673 lock->bast = bast;
674 lock->astdata = data;
675
676retry_lock:
677 if (flags & LKM_VALBLK) {
678 mlog(0, "LKM_VALBLK passed by caller\n");
679
680 /* LVB requests for non PR, PW or EX locks are
681 * ignored. */
682 if (mode < LKM_PRMODE)
683 flags &= ~LKM_VALBLK;
684 else {
685 flags |= LKM_GET_LVB;
686 lock->lksb->flags |= DLM_LKSB_GET_LVB;
687 }
688 }
689
690 if (res->owner == dlm->node_num)
691 status = dlmlock_master(dlm, res, lock, flags);
692 else
693 status = dlmlock_remote(dlm, res, lock, flags);
694
695 if (status == DLM_RECOVERING || status == DLM_MIGRATING ||
696 status == DLM_FORWARD) {
697 msleep(100);
698 if (recovery) {
699 if (status != DLM_RECOVERING)
700 goto retry_lock;
701 /* wait to see the node go down, then
702 * drop down and allow the lockres to
703 * get cleaned up. need to remaster. */
704 dlm_wait_for_node_death(dlm, res->owner,
705 DLM_NODE_DEATH_WAIT_MAX);
706 } else {
707 dlm_wait_for_recovery(dlm);
708 goto retry_lock;
709 }
710 }
711
712 /* Inflight taken in dlm_get_lock_resource() is dropped here */
713 spin_lock(&res->spinlock);
714 dlm_lockres_drop_inflight_ref(dlm, res);
715 spin_unlock(&res->spinlock);
716
717 dlm_lockres_calc_usage(dlm, res);
718 dlm_kick_thread(dlm, res);
719
720 if (status != DLM_NORMAL) {
721 lock->lksb->flags &= ~DLM_LKSB_GET_LVB;
722 if (status != DLM_NOTQUEUED)
723 dlm_error(status);
724 goto error;
725 }
726 }
727
728error:
729 if (status != DLM_NORMAL) {
730 if (lock && !convert)
731 dlm_lock_put(lock);
732 // this is kind of unnecessary
733 lksb->status = status;
734 }
735
736 /* put lockres ref from the convert path
737 * or from dlm_get_lock_resource */
738 if (res)
739 dlm_lockres_put(res);
740
741 return status;
742}
743EXPORT_SYMBOL_GPL(dlmlock);
1/* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * dlmlock.c
5 *
6 * underlying calls for lock creation
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/init.h>
34#include <linux/sysctl.h>
35#include <linux/random.h>
36#include <linux/blkdev.h>
37#include <linux/socket.h>
38#include <linux/inet.h>
39#include <linux/spinlock.h>
40#include <linux/delay.h>
41
42
43#include "cluster/heartbeat.h"
44#include "cluster/nodemanager.h"
45#include "cluster/tcp.h"
46
47#include "dlmapi.h"
48#include "dlmcommon.h"
49
50#include "dlmconvert.h"
51
52#define MLOG_MASK_PREFIX ML_DLM
53#include "cluster/masklog.h"
54
55static struct kmem_cache *dlm_lock_cache = NULL;
56
57static DEFINE_SPINLOCK(dlm_cookie_lock);
58static u64 dlm_next_cookie = 1;
59
60static enum dlm_status dlm_send_remote_lock_request(struct dlm_ctxt *dlm,
61 struct dlm_lock_resource *res,
62 struct dlm_lock *lock, int flags);
63static void dlm_init_lock(struct dlm_lock *newlock, int type,
64 u8 node, u64 cookie);
65static void dlm_lock_release(struct kref *kref);
66static void dlm_lock_detach_lockres(struct dlm_lock *lock);
67
68int dlm_init_lock_cache(void)
69{
70 dlm_lock_cache = kmem_cache_create("o2dlm_lock",
71 sizeof(struct dlm_lock),
72 0, SLAB_HWCACHE_ALIGN, NULL);
73 if (dlm_lock_cache == NULL)
74 return -ENOMEM;
75 return 0;
76}
77
78void dlm_destroy_lock_cache(void)
79{
80 if (dlm_lock_cache)
81 kmem_cache_destroy(dlm_lock_cache);
82}
83
84/* Tell us whether we can grant a new lock request.
85 * locking:
86 * caller needs: res->spinlock
87 * taken: none
88 * held on exit: none
89 * returns: 1 if the lock can be granted, 0 otherwise.
90 */
91static int dlm_can_grant_new_lock(struct dlm_lock_resource *res,
92 struct dlm_lock *lock)
93{
94 struct list_head *iter;
95 struct dlm_lock *tmplock;
96
97 list_for_each(iter, &res->granted) {
98 tmplock = list_entry(iter, struct dlm_lock, list);
99
100 if (!dlm_lock_compatible(tmplock->ml.type, lock->ml.type))
101 return 0;
102 }
103
104 list_for_each(iter, &res->converting) {
105 tmplock = list_entry(iter, struct dlm_lock, list);
106
107 if (!dlm_lock_compatible(tmplock->ml.type, lock->ml.type))
108 return 0;
109 if (!dlm_lock_compatible(tmplock->ml.convert_type,
110 lock->ml.type))
111 return 0;
112 }
113
114 return 1;
115}
116
117/* performs lock creation at the lockres master site
118 * locking:
119 * caller needs: none
120 * taken: takes and drops res->spinlock
121 * held on exit: none
122 * returns: DLM_NORMAL, DLM_NOTQUEUED
123 */
124static enum dlm_status dlmlock_master(struct dlm_ctxt *dlm,
125 struct dlm_lock_resource *res,
126 struct dlm_lock *lock, int flags)
127{
128 int call_ast = 0, kick_thread = 0;
129 enum dlm_status status = DLM_NORMAL;
130
131 mlog(0, "type=%d\n", lock->ml.type);
132
133 spin_lock(&res->spinlock);
134 /* if called from dlm_create_lock_handler, need to
135 * ensure it will not sleep in dlm_wait_on_lockres */
136 status = __dlm_lockres_state_to_status(res);
137 if (status != DLM_NORMAL &&
138 lock->ml.node != dlm->node_num) {
139 /* erf. state changed after lock was dropped. */
140 spin_unlock(&res->spinlock);
141 dlm_error(status);
142 return status;
143 }
144 __dlm_wait_on_lockres(res);
145 __dlm_lockres_reserve_ast(res);
146
147 if (dlm_can_grant_new_lock(res, lock)) {
148 mlog(0, "I can grant this lock right away\n");
149 /* got it right away */
150 lock->lksb->status = DLM_NORMAL;
151 status = DLM_NORMAL;
152 dlm_lock_get(lock);
153 list_add_tail(&lock->list, &res->granted);
154
155 /* for the recovery lock, we can't allow the ast
156 * to be queued since the dlmthread is already
157 * frozen. but the recovery lock is always locked
158 * with LKM_NOQUEUE so we do not need the ast in
159 * this special case */
160 if (!dlm_is_recovery_lock(res->lockname.name,
161 res->lockname.len)) {
162 kick_thread = 1;
163 call_ast = 1;
164 } else {
165 mlog(0, "%s: returning DLM_NORMAL to "
166 "node %u for reco lock\n", dlm->name,
167 lock->ml.node);
168 }
169 } else {
170 /* for NOQUEUE request, unless we get the
171 * lock right away, return DLM_NOTQUEUED */
172 if (flags & LKM_NOQUEUE) {
173 status = DLM_NOTQUEUED;
174 if (dlm_is_recovery_lock(res->lockname.name,
175 res->lockname.len)) {
176 mlog(0, "%s: returning NOTQUEUED to "
177 "node %u for reco lock\n", dlm->name,
178 lock->ml.node);
179 }
180 } else {
181 dlm_lock_get(lock);
182 list_add_tail(&lock->list, &res->blocked);
183 kick_thread = 1;
184 }
185 }
186 /* reduce the inflight count, this may result in the lockres
187 * being purged below during calc_usage */
188 if (lock->ml.node == dlm->node_num)
189 dlm_lockres_drop_inflight_ref(dlm, res);
190
191 spin_unlock(&res->spinlock);
192 wake_up(&res->wq);
193
194 /* either queue the ast or release it */
195 if (call_ast)
196 dlm_queue_ast(dlm, lock);
197 else
198 dlm_lockres_release_ast(dlm, res);
199
200 dlm_lockres_calc_usage(dlm, res);
201 if (kick_thread)
202 dlm_kick_thread(dlm, res);
203
204 return status;
205}
206
207void dlm_revert_pending_lock(struct dlm_lock_resource *res,
208 struct dlm_lock *lock)
209{
210 /* remove from local queue if it failed */
211 list_del_init(&lock->list);
212 lock->lksb->flags &= ~DLM_LKSB_GET_LVB;
213}
214
215
216/*
217 * locking:
218 * caller needs: none
219 * taken: takes and drops res->spinlock
220 * held on exit: none
221 * returns: DLM_DENIED, DLM_RECOVERING, or net status
222 */
223static enum dlm_status dlmlock_remote(struct dlm_ctxt *dlm,
224 struct dlm_lock_resource *res,
225 struct dlm_lock *lock, int flags)
226{
227 enum dlm_status status = DLM_DENIED;
228 int lockres_changed = 1;
229
230 mlog(0, "type=%d, lockres %.*s, flags = 0x%x\n",
231 lock->ml.type, res->lockname.len,
232 res->lockname.name, flags);
233
234 spin_lock(&res->spinlock);
235
236 /* will exit this call with spinlock held */
237 __dlm_wait_on_lockres(res);
238 res->state |= DLM_LOCK_RES_IN_PROGRESS;
239
240 /* add lock to local (secondary) queue */
241 dlm_lock_get(lock);
242 list_add_tail(&lock->list, &res->blocked);
243 lock->lock_pending = 1;
244 spin_unlock(&res->spinlock);
245
246 /* spec seems to say that you will get DLM_NORMAL when the lock
247 * has been queued, meaning we need to wait for a reply here. */
248 status = dlm_send_remote_lock_request(dlm, res, lock, flags);
249
250 spin_lock(&res->spinlock);
251 res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
252 lock->lock_pending = 0;
253 if (status != DLM_NORMAL) {
254 if (status == DLM_RECOVERING &&
255 dlm_is_recovery_lock(res->lockname.name,
256 res->lockname.len)) {
257 /* recovery lock was mastered by dead node.
258 * we need to have calc_usage shoot down this
259 * lockres and completely remaster it. */
260 mlog(0, "%s: recovery lock was owned by "
261 "dead node %u, remaster it now.\n",
262 dlm->name, res->owner);
263 } else if (status != DLM_NOTQUEUED) {
264 /*
265 * DO NOT call calc_usage, as this would unhash
266 * the remote lockres before we ever get to use
267 * it. treat as if we never made any change to
268 * the lockres.
269 */
270 lockres_changed = 0;
271 dlm_error(status);
272 }
273 dlm_revert_pending_lock(res, lock);
274 dlm_lock_put(lock);
275 } else if (dlm_is_recovery_lock(res->lockname.name,
276 res->lockname.len)) {
277 /* special case for the $RECOVERY lock.
278 * there will never be an AST delivered to put
279 * this lock on the proper secondary queue
280 * (granted), so do it manually. */
281 mlog(0, "%s: $RECOVERY lock for this node (%u) is "
282 "mastered by %u; got lock, manually granting (no ast)\n",
283 dlm->name, dlm->node_num, res->owner);
284 list_move_tail(&lock->list, &res->granted);
285 }
286 spin_unlock(&res->spinlock);
287
288 if (lockres_changed)
289 dlm_lockres_calc_usage(dlm, res);
290
291 wake_up(&res->wq);
292 return status;
293}
294
295
296/* for remote lock creation.
297 * locking:
298 * caller needs: none, but need res->state & DLM_LOCK_RES_IN_PROGRESS
299 * taken: none
300 * held on exit: none
301 * returns: DLM_NOLOCKMGR, or net status
302 */
303static enum dlm_status dlm_send_remote_lock_request(struct dlm_ctxt *dlm,
304 struct dlm_lock_resource *res,
305 struct dlm_lock *lock, int flags)
306{
307 struct dlm_create_lock create;
308 int tmpret, status = 0;
309 enum dlm_status ret;
310
311 memset(&create, 0, sizeof(create));
312 create.node_idx = dlm->node_num;
313 create.requested_type = lock->ml.type;
314 create.cookie = lock->ml.cookie;
315 create.namelen = res->lockname.len;
316 create.flags = cpu_to_be32(flags);
317 memcpy(create.name, res->lockname.name, create.namelen);
318
319 tmpret = o2net_send_message(DLM_CREATE_LOCK_MSG, dlm->key, &create,
320 sizeof(create), res->owner, &status);
321 if (tmpret >= 0) {
322 // successfully sent and received
323 ret = status; // this is already a dlm_status
324 if (ret == DLM_REJECTED) {
325 mlog(ML_ERROR, "%s:%.*s: BUG. this is a stale lockres "
326 "no longer owned by %u. that node is coming back "
327 "up currently.\n", dlm->name, create.namelen,
328 create.name, res->owner);
329 dlm_print_one_lock_resource(res);
330 BUG();
331 }
332 } else {
333 mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
334 "node %u\n", tmpret, DLM_CREATE_LOCK_MSG, dlm->key,
335 res->owner);
336 if (dlm_is_host_down(tmpret)) {
337 ret = DLM_RECOVERING;
338 mlog(0, "node %u died so returning DLM_RECOVERING "
339 "from lock message!\n", res->owner);
340 } else {
341 ret = dlm_err_to_dlm_status(tmpret);
342 }
343 }
344
345 return ret;
346}
347
348void dlm_lock_get(struct dlm_lock *lock)
349{
350 kref_get(&lock->lock_refs);
351}
352
353void dlm_lock_put(struct dlm_lock *lock)
354{
355 kref_put(&lock->lock_refs, dlm_lock_release);
356}
357
358static void dlm_lock_release(struct kref *kref)
359{
360 struct dlm_lock *lock;
361
362 lock = container_of(kref, struct dlm_lock, lock_refs);
363
364 BUG_ON(!list_empty(&lock->list));
365 BUG_ON(!list_empty(&lock->ast_list));
366 BUG_ON(!list_empty(&lock->bast_list));
367 BUG_ON(lock->ast_pending);
368 BUG_ON(lock->bast_pending);
369
370 dlm_lock_detach_lockres(lock);
371
372 if (lock->lksb_kernel_allocated) {
373 mlog(0, "freeing kernel-allocated lksb\n");
374 kfree(lock->lksb);
375 }
376 kmem_cache_free(dlm_lock_cache, lock);
377}
378
379/* associate a lock with it's lockres, getting a ref on the lockres */
380void dlm_lock_attach_lockres(struct dlm_lock *lock,
381 struct dlm_lock_resource *res)
382{
383 dlm_lockres_get(res);
384 lock->lockres = res;
385}
386
387/* drop ref on lockres, if there is still one associated with lock */
388static void dlm_lock_detach_lockres(struct dlm_lock *lock)
389{
390 struct dlm_lock_resource *res;
391
392 res = lock->lockres;
393 if (res) {
394 lock->lockres = NULL;
395 mlog(0, "removing lock's lockres reference\n");
396 dlm_lockres_put(res);
397 }
398}
399
400static void dlm_init_lock(struct dlm_lock *newlock, int type,
401 u8 node, u64 cookie)
402{
403 INIT_LIST_HEAD(&newlock->list);
404 INIT_LIST_HEAD(&newlock->ast_list);
405 INIT_LIST_HEAD(&newlock->bast_list);
406 spin_lock_init(&newlock->spinlock);
407 newlock->ml.type = type;
408 newlock->ml.convert_type = LKM_IVMODE;
409 newlock->ml.highest_blocked = LKM_IVMODE;
410 newlock->ml.node = node;
411 newlock->ml.pad1 = 0;
412 newlock->ml.list = 0;
413 newlock->ml.flags = 0;
414 newlock->ast = NULL;
415 newlock->bast = NULL;
416 newlock->astdata = NULL;
417 newlock->ml.cookie = cpu_to_be64(cookie);
418 newlock->ast_pending = 0;
419 newlock->bast_pending = 0;
420 newlock->convert_pending = 0;
421 newlock->lock_pending = 0;
422 newlock->unlock_pending = 0;
423 newlock->cancel_pending = 0;
424 newlock->lksb_kernel_allocated = 0;
425
426 kref_init(&newlock->lock_refs);
427}
428
429struct dlm_lock * dlm_new_lock(int type, u8 node, u64 cookie,
430 struct dlm_lockstatus *lksb)
431{
432 struct dlm_lock *lock;
433 int kernel_allocated = 0;
434
435 lock = kmem_cache_zalloc(dlm_lock_cache, GFP_NOFS);
436 if (!lock)
437 return NULL;
438
439 if (!lksb) {
440 /* zero memory only if kernel-allocated */
441 lksb = kzalloc(sizeof(*lksb), GFP_NOFS);
442 if (!lksb) {
443 kfree(lock);
444 return NULL;
445 }
446 kernel_allocated = 1;
447 }
448
449 dlm_init_lock(lock, type, node, cookie);
450 if (kernel_allocated)
451 lock->lksb_kernel_allocated = 1;
452 lock->lksb = lksb;
453 lksb->lockid = lock;
454 return lock;
455}
456
457/* handler for lock creation net message
458 * locking:
459 * caller needs: none
460 * taken: takes and drops res->spinlock
461 * held on exit: none
462 * returns: DLM_NORMAL, DLM_SYSERR, DLM_IVLOCKID, DLM_NOTQUEUED
463 */
464int dlm_create_lock_handler(struct o2net_msg *msg, u32 len, void *data,
465 void **ret_data)
466{
467 struct dlm_ctxt *dlm = data;
468 struct dlm_create_lock *create = (struct dlm_create_lock *)msg->buf;
469 struct dlm_lock_resource *res = NULL;
470 struct dlm_lock *newlock = NULL;
471 struct dlm_lockstatus *lksb = NULL;
472 enum dlm_status status = DLM_NORMAL;
473 char *name;
474 unsigned int namelen;
475
476 BUG_ON(!dlm);
477
478 if (!dlm_grab(dlm))
479 return DLM_REJECTED;
480
481 name = create->name;
482 namelen = create->namelen;
483 status = DLM_REJECTED;
484 if (!dlm_domain_fully_joined(dlm)) {
485 mlog(ML_ERROR, "Domain %s not fully joined, but node %u is "
486 "sending a create_lock message for lock %.*s!\n",
487 dlm->name, create->node_idx, namelen, name);
488 dlm_error(status);
489 goto leave;
490 }
491
492 status = DLM_IVBUFLEN;
493 if (namelen > DLM_LOCKID_NAME_MAX) {
494 dlm_error(status);
495 goto leave;
496 }
497
498 status = DLM_SYSERR;
499 newlock = dlm_new_lock(create->requested_type,
500 create->node_idx,
501 be64_to_cpu(create->cookie), NULL);
502 if (!newlock) {
503 dlm_error(status);
504 goto leave;
505 }
506
507 lksb = newlock->lksb;
508
509 if (be32_to_cpu(create->flags) & LKM_GET_LVB) {
510 lksb->flags |= DLM_LKSB_GET_LVB;
511 mlog(0, "set DLM_LKSB_GET_LVB flag\n");
512 }
513
514 status = DLM_IVLOCKID;
515 res = dlm_lookup_lockres(dlm, name, namelen);
516 if (!res) {
517 dlm_error(status);
518 goto leave;
519 }
520
521 spin_lock(&res->spinlock);
522 status = __dlm_lockres_state_to_status(res);
523 spin_unlock(&res->spinlock);
524
525 if (status != DLM_NORMAL) {
526 mlog(0, "lockres recovering/migrating/in-progress\n");
527 goto leave;
528 }
529
530 dlm_lock_attach_lockres(newlock, res);
531
532 status = dlmlock_master(dlm, res, newlock, be32_to_cpu(create->flags));
533leave:
534 if (status != DLM_NORMAL)
535 if (newlock)
536 dlm_lock_put(newlock);
537
538 if (res)
539 dlm_lockres_put(res);
540
541 dlm_put(dlm);
542
543 return status;
544}
545
546
547/* fetch next node-local (u8 nodenum + u56 cookie) into u64 */
548static inline void dlm_get_next_cookie(u8 node_num, u64 *cookie)
549{
550 u64 tmpnode = node_num;
551
552 /* shift single byte of node num into top 8 bits */
553 tmpnode <<= 56;
554
555 spin_lock(&dlm_cookie_lock);
556 *cookie = (dlm_next_cookie | tmpnode);
557 if (++dlm_next_cookie & 0xff00000000000000ull) {
558 mlog(0, "This node's cookie will now wrap!\n");
559 dlm_next_cookie = 1;
560 }
561 spin_unlock(&dlm_cookie_lock);
562}
563
564enum dlm_status dlmlock(struct dlm_ctxt *dlm, int mode,
565 struct dlm_lockstatus *lksb, int flags,
566 const char *name, int namelen, dlm_astlockfunc_t *ast,
567 void *data, dlm_bastlockfunc_t *bast)
568{
569 enum dlm_status status;
570 struct dlm_lock_resource *res = NULL;
571 struct dlm_lock *lock = NULL;
572 int convert = 0, recovery = 0;
573
574 /* yes this function is a mess.
575 * TODO: clean this up. lots of common code in the
576 * lock and convert paths, especially in the retry blocks */
577 if (!lksb) {
578 dlm_error(DLM_BADARGS);
579 return DLM_BADARGS;
580 }
581
582 status = DLM_BADPARAM;
583 if (mode != LKM_EXMODE && mode != LKM_PRMODE && mode != LKM_NLMODE) {
584 dlm_error(status);
585 goto error;
586 }
587
588 if (flags & ~LKM_VALID_FLAGS) {
589 dlm_error(status);
590 goto error;
591 }
592
593 convert = (flags & LKM_CONVERT);
594 recovery = (flags & LKM_RECOVERY);
595
596 if (recovery &&
597 (!dlm_is_recovery_lock(name, namelen) || convert) ) {
598 dlm_error(status);
599 goto error;
600 }
601 if (convert && (flags & LKM_LOCAL)) {
602 mlog(ML_ERROR, "strange LOCAL convert request!\n");
603 goto error;
604 }
605
606 if (convert) {
607 /* CONVERT request */
608
609 /* if converting, must pass in a valid dlm_lock */
610 lock = lksb->lockid;
611 if (!lock) {
612 mlog(ML_ERROR, "NULL lock pointer in convert "
613 "request\n");
614 goto error;
615 }
616
617 res = lock->lockres;
618 if (!res) {
619 mlog(ML_ERROR, "NULL lockres pointer in convert "
620 "request\n");
621 goto error;
622 }
623 dlm_lockres_get(res);
624
625 /* XXX: for ocfs2 purposes, the ast/bast/astdata/lksb are
626 * static after the original lock call. convert requests will
627 * ensure that everything is the same, or return DLM_BADARGS.
628 * this means that DLM_DENIED_NOASTS will never be returned.
629 */
630 if (lock->lksb != lksb || lock->ast != ast ||
631 lock->bast != bast || lock->astdata != data) {
632 status = DLM_BADARGS;
633 mlog(ML_ERROR, "new args: lksb=%p, ast=%p, bast=%p, "
634 "astdata=%p\n", lksb, ast, bast, data);
635 mlog(ML_ERROR, "orig args: lksb=%p, ast=%p, bast=%p, "
636 "astdata=%p\n", lock->lksb, lock->ast,
637 lock->bast, lock->astdata);
638 goto error;
639 }
640retry_convert:
641 dlm_wait_for_recovery(dlm);
642
643 if (res->owner == dlm->node_num)
644 status = dlmconvert_master(dlm, res, lock, flags, mode);
645 else
646 status = dlmconvert_remote(dlm, res, lock, flags, mode);
647 if (status == DLM_RECOVERING || status == DLM_MIGRATING ||
648 status == DLM_FORWARD) {
649 /* for now, see how this works without sleeping
650 * and just retry right away. I suspect the reco
651 * or migration will complete fast enough that
652 * no waiting will be necessary */
653 mlog(0, "retrying convert with migration/recovery/"
654 "in-progress\n");
655 msleep(100);
656 goto retry_convert;
657 }
658 } else {
659 u64 tmpcookie;
660
661 /* LOCK request */
662 status = DLM_BADARGS;
663 if (!name) {
664 dlm_error(status);
665 goto error;
666 }
667
668 status = DLM_IVBUFLEN;
669 if (namelen > DLM_LOCKID_NAME_MAX || namelen < 1) {
670 dlm_error(status);
671 goto error;
672 }
673
674 dlm_get_next_cookie(dlm->node_num, &tmpcookie);
675 lock = dlm_new_lock(mode, dlm->node_num, tmpcookie, lksb);
676 if (!lock) {
677 dlm_error(status);
678 goto error;
679 }
680
681 if (!recovery)
682 dlm_wait_for_recovery(dlm);
683
684 /* find or create the lock resource */
685 res = dlm_get_lock_resource(dlm, name, namelen, flags);
686 if (!res) {
687 status = DLM_IVLOCKID;
688 dlm_error(status);
689 goto error;
690 }
691
692 mlog(0, "type=%d, flags = 0x%x\n", mode, flags);
693 mlog(0, "creating lock: lock=%p res=%p\n", lock, res);
694
695 dlm_lock_attach_lockres(lock, res);
696 lock->ast = ast;
697 lock->bast = bast;
698 lock->astdata = data;
699
700retry_lock:
701 if (flags & LKM_VALBLK) {
702 mlog(0, "LKM_VALBLK passed by caller\n");
703
704 /* LVB requests for non PR, PW or EX locks are
705 * ignored. */
706 if (mode < LKM_PRMODE)
707 flags &= ~LKM_VALBLK;
708 else {
709 flags |= LKM_GET_LVB;
710 lock->lksb->flags |= DLM_LKSB_GET_LVB;
711 }
712 }
713
714 if (res->owner == dlm->node_num)
715 status = dlmlock_master(dlm, res, lock, flags);
716 else
717 status = dlmlock_remote(dlm, res, lock, flags);
718
719 if (status == DLM_RECOVERING || status == DLM_MIGRATING ||
720 status == DLM_FORWARD) {
721 mlog(0, "retrying lock with migration/"
722 "recovery/in progress\n");
723 msleep(100);
724 /* no waiting for dlm_reco_thread */
725 if (recovery) {
726 if (status != DLM_RECOVERING)
727 goto retry_lock;
728
729 mlog(0, "%s: got RECOVERING "
730 "for $RECOVERY lock, master "
731 "was %u\n", dlm->name,
732 res->owner);
733 /* wait to see the node go down, then
734 * drop down and allow the lockres to
735 * get cleaned up. need to remaster. */
736 dlm_wait_for_node_death(dlm, res->owner,
737 DLM_NODE_DEATH_WAIT_MAX);
738 } else {
739 dlm_wait_for_recovery(dlm);
740 goto retry_lock;
741 }
742 }
743
744 if (status != DLM_NORMAL) {
745 lock->lksb->flags &= ~DLM_LKSB_GET_LVB;
746 if (status != DLM_NOTQUEUED)
747 dlm_error(status);
748 goto error;
749 }
750 }
751
752error:
753 if (status != DLM_NORMAL) {
754 if (lock && !convert)
755 dlm_lock_put(lock);
756 // this is kind of unnecessary
757 lksb->status = status;
758 }
759
760 /* put lockres ref from the convert path
761 * or from dlm_get_lock_resource */
762 if (res)
763 dlm_lockres_put(res);
764
765 return status;
766}
767EXPORT_SYMBOL_GPL(dlmlock);