1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* -*- mode: c; c-basic-offset: 8; -*-
3 * vim: noexpandtab sw=8 ts=8 sts=0:
4 *
5 * dlmunlock.c
6 *
7 * underlying calls for unlocking locks
8 *
9 * Copyright (C) 2004 Oracle. All rights reserved.
10 */
11
12
13 #include <linux/module.h>
14 #include <linux/fs.h>
15 #include <linux/types.h>
16 #include <linux/highmem.h>
17 #include <linux/init.h>
18 #include <linux/sysctl.h>
19 #include <linux/random.h>
20 #include <linux/blkdev.h>
21 #include <linux/socket.h>
22 #include <linux/inet.h>
23 #include <linux/spinlock.h>
24 #include <linux/delay.h>
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 #define MLOG_MASK_PREFIX ML_DLM
34 #include "../cluster/masklog.h"
35
36 #define DLM_UNLOCK_FREE_LOCK 0x00000001
37 #define DLM_UNLOCK_CALL_AST 0x00000002
38 #define DLM_UNLOCK_REMOVE_LOCK 0x00000004
39 #define DLM_UNLOCK_REGRANT_LOCK 0x00000008
40 #define DLM_UNLOCK_CLEAR_CONVERT_TYPE 0x00000010
41
42
43 static enum dlm_status dlm_get_cancel_actions(struct dlm_ctxt *dlm,
44 struct dlm_lock_resource *res,
45 struct dlm_lock *lock,
46 struct dlm_lockstatus *lksb,
47 int *actions);
48 static enum dlm_status dlm_get_unlock_actions(struct dlm_ctxt *dlm,
49 struct dlm_lock_resource *res,
50 struct dlm_lock *lock,
51 struct dlm_lockstatus *lksb,
52 int *actions);
53
54 static enum dlm_status dlm_send_remote_unlock_request(struct dlm_ctxt *dlm,
55 struct dlm_lock_resource *res,
56 struct dlm_lock *lock,
57 struct dlm_lockstatus *lksb,
58 int flags,
59 u8 owner);
60
61
62 /*
63 * according to the spec:
64 * http://opendlm.sourceforge.net/cvsmirror/opendlm/docs/dlmbook_final.pdf
65 *
66 * flags & LKM_CANCEL != 0: must be converting or blocked
67 * flags & LKM_CANCEL == 0: must be granted
68 *
69 * So to unlock a converting lock, you must first cancel the
70 * convert (passing LKM_CANCEL in flags), then call the unlock
71 * again (with no LKM_CANCEL in flags).
72 */
73
74
75 /*
76 * locking:
77 * caller needs: none
78 * taken: res->spinlock and lock->spinlock taken and dropped
79 * held on exit: none
80 * returns: DLM_NORMAL, DLM_NOLOCKMGR, status from network
81 * all callers should have taken an extra ref on lock coming in
82 */
dlmunlock_common(struct dlm_ctxt * dlm,struct dlm_lock_resource * res,struct dlm_lock * lock,struct dlm_lockstatus * lksb,int flags,int * call_ast,int master_node)83 static enum dlm_status dlmunlock_common(struct dlm_ctxt *dlm,
84 struct dlm_lock_resource *res,
85 struct dlm_lock *lock,
86 struct dlm_lockstatus *lksb,
87 int flags, int *call_ast,
88 int master_node)
89 {
90 enum dlm_status status;
91 int actions = 0;
92 int in_use;
93 u8 owner;
94 int recovery_wait = 0;
95
96 mlog(0, "master_node = %d, valblk = %d\n", master_node,
97 flags & LKM_VALBLK);
98
99 if (master_node)
100 BUG_ON(res->owner != dlm->node_num);
101 else
102 BUG_ON(res->owner == dlm->node_num);
103
104 spin_lock(&dlm->ast_lock);
105 /* We want to be sure that we're not freeing a lock
106 * that still has AST's pending... */
107 in_use = !list_empty(&lock->ast_list);
108 spin_unlock(&dlm->ast_lock);
109 if (in_use && !(flags & LKM_CANCEL)) {
110 mlog(ML_ERROR, "lockres %.*s: Someone is calling dlmunlock "
111 "while waiting for an ast!", res->lockname.len,
112 res->lockname.name);
113 return DLM_BADPARAM;
114 }
115
116 spin_lock(&res->spinlock);
117 if (res->state & DLM_LOCK_RES_IN_PROGRESS) {
118 if (master_node && !(flags & LKM_CANCEL)) {
119 mlog(ML_ERROR, "lockres in progress!\n");
120 spin_unlock(&res->spinlock);
121 return DLM_FORWARD;
122 }
123 /* ok for this to sleep if not in a network handler */
124 __dlm_wait_on_lockres(res);
125 res->state |= DLM_LOCK_RES_IN_PROGRESS;
126 }
127 spin_lock(&lock->spinlock);
128
129 if (res->state & DLM_LOCK_RES_RECOVERING) {
130 status = DLM_RECOVERING;
131 goto leave;
132 }
133
134 if (res->state & DLM_LOCK_RES_MIGRATING) {
135 status = DLM_MIGRATING;
136 goto leave;
137 }
138
139 /* see above for what the spec says about
140 * LKM_CANCEL and the lock queue state */
141 if (flags & LKM_CANCEL)
142 status = dlm_get_cancel_actions(dlm, res, lock, lksb, &actions);
143 else
144 status = dlm_get_unlock_actions(dlm, res, lock, lksb, &actions);
145
146 if (status != DLM_NORMAL && (status != DLM_CANCELGRANT || !master_node))
147 goto leave;
148
149 /* By now this has been masked out of cancel requests. */
150 if (flags & LKM_VALBLK) {
151 /* make the final update to the lvb */
152 if (master_node)
153 memcpy(res->lvb, lksb->lvb, DLM_LVB_LEN);
154 else
155 flags |= LKM_PUT_LVB; /* let the send function
156 * handle it. */
157 }
158
159 if (!master_node) {
160 owner = res->owner;
161 /* drop locks and send message */
162 if (flags & LKM_CANCEL)
163 lock->cancel_pending = 1;
164 else
165 lock->unlock_pending = 1;
166 spin_unlock(&lock->spinlock);
167 spin_unlock(&res->spinlock);
168 status = dlm_send_remote_unlock_request(dlm, res, lock, lksb,
169 flags, owner);
170 spin_lock(&res->spinlock);
171 spin_lock(&lock->spinlock);
172 /* if the master told us the lock was already granted,
173 * let the ast handle all of these actions */
174 if (status == DLM_CANCELGRANT) {
175 actions &= ~(DLM_UNLOCK_REMOVE_LOCK|
176 DLM_UNLOCK_REGRANT_LOCK|
177 DLM_UNLOCK_CLEAR_CONVERT_TYPE);
178 } else if (status == DLM_RECOVERING ||
179 status == DLM_MIGRATING ||
180 status == DLM_FORWARD ||
181 status == DLM_NOLOCKMGR
182 ) {
183 /* must clear the actions because this unlock
184 * is about to be retried. cannot free or do
185 * any list manipulation. */
186 mlog(0, "%s:%.*s: clearing actions, %s\n",
187 dlm->name, res->lockname.len,
188 res->lockname.name,
189 status==DLM_RECOVERING?"recovering":
190 (status==DLM_MIGRATING?"migrating":
191 (status == DLM_FORWARD ? "forward" :
192 "nolockmanager")));
193 actions = 0;
194 }
195 if (flags & LKM_CANCEL)
196 lock->cancel_pending = 0;
197 else {
198 if (!lock->unlock_pending)
199 recovery_wait = 1;
200 else
201 lock->unlock_pending = 0;
202 }
203 }
204
205 /* get an extra ref on lock. if we are just switching
206 * lists here, we dont want the lock to go away. */
207 dlm_lock_get(lock);
208
209 if (actions & DLM_UNLOCK_REMOVE_LOCK) {
210 list_del_init(&lock->list);
211 dlm_lock_put(lock);
212 }
213 if (actions & DLM_UNLOCK_REGRANT_LOCK) {
214 dlm_lock_get(lock);
215 list_add_tail(&lock->list, &res->granted);
216 }
217 if (actions & DLM_UNLOCK_CLEAR_CONVERT_TYPE) {
218 mlog(0, "clearing convert_type at %smaster node\n",
219 master_node ? "" : "non-");
220 lock->ml.convert_type = LKM_IVMODE;
221 }
222
223 /* remove the extra ref on lock */
224 dlm_lock_put(lock);
225
226 leave:
227 res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
228 if (!dlm_lock_on_list(&res->converting, lock))
229 BUG_ON(lock->ml.convert_type != LKM_IVMODE);
230 else
231 BUG_ON(lock->ml.convert_type == LKM_IVMODE);
232 spin_unlock(&lock->spinlock);
233 spin_unlock(&res->spinlock);
234 wake_up(&res->wq);
235
236 if (recovery_wait) {
237 spin_lock(&res->spinlock);
238 /* Unlock request will directly succeed after owner dies,
239 * and the lock is already removed from grant list. We have to
240 * wait for RECOVERING done or we miss the chance to purge it
241 * since the removement is much faster than RECOVERING proc.
242 */
243 __dlm_wait_on_lockres_flags(res, DLM_LOCK_RES_RECOVERING);
244 spin_unlock(&res->spinlock);
245 }
246
247 /* let the caller's final dlm_lock_put handle the actual kfree */
248 if (actions & DLM_UNLOCK_FREE_LOCK) {
249 /* this should always be coupled with list removal */
250 BUG_ON(!(actions & DLM_UNLOCK_REMOVE_LOCK));
251 mlog(0, "lock %u:%llu should be gone now! refs=%d\n",
252 dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
253 dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
254 kref_read(&lock->lock_refs)-1);
255 dlm_lock_put(lock);
256 }
257 if (actions & DLM_UNLOCK_CALL_AST)
258 *call_ast = 1;
259
260 /* if cancel or unlock succeeded, lvb work is done */
261 if (status == DLM_NORMAL)
262 lksb->flags &= ~(DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB);
263
264 return status;
265 }
266
dlm_commit_pending_unlock(struct dlm_lock_resource * res,struct dlm_lock * lock)267 void dlm_commit_pending_unlock(struct dlm_lock_resource *res,
268 struct dlm_lock *lock)
269 {
270 /* leave DLM_LKSB_PUT_LVB on the lksb so any final
271 * update of the lvb will be sent to the new master */
272 list_del_init(&lock->list);
273 }
274
dlm_commit_pending_cancel(struct dlm_lock_resource * res,struct dlm_lock * lock)275 void dlm_commit_pending_cancel(struct dlm_lock_resource *res,
276 struct dlm_lock *lock)
277 {
278 list_move_tail(&lock->list, &res->granted);
279 lock->ml.convert_type = LKM_IVMODE;
280 }
281
282
dlmunlock_master(struct dlm_ctxt * dlm,struct dlm_lock_resource * res,struct dlm_lock * lock,struct dlm_lockstatus * lksb,int flags,int * call_ast)283 static inline enum dlm_status dlmunlock_master(struct dlm_ctxt *dlm,
284 struct dlm_lock_resource *res,
285 struct dlm_lock *lock,
286 struct dlm_lockstatus *lksb,
287 int flags,
288 int *call_ast)
289 {
290 return dlmunlock_common(dlm, res, lock, lksb, flags, call_ast, 1);
291 }
292
dlmunlock_remote(struct dlm_ctxt * dlm,struct dlm_lock_resource * res,struct dlm_lock * lock,struct dlm_lockstatus * lksb,int flags,int * call_ast)293 static inline enum dlm_status dlmunlock_remote(struct dlm_ctxt *dlm,
294 struct dlm_lock_resource *res,
295 struct dlm_lock *lock,
296 struct dlm_lockstatus *lksb,
297 int flags, int *call_ast)
298 {
299 return dlmunlock_common(dlm, res, lock, lksb, flags, call_ast, 0);
300 }
301
302 /*
303 * locking:
304 * caller needs: none
305 * taken: none
306 * held on exit: none
307 * returns: DLM_NORMAL, DLM_NOLOCKMGR, status from network
308 */
dlm_send_remote_unlock_request(struct dlm_ctxt * dlm,struct dlm_lock_resource * res,struct dlm_lock * lock,struct dlm_lockstatus * lksb,int flags,u8 owner)309 static enum dlm_status dlm_send_remote_unlock_request(struct dlm_ctxt *dlm,
310 struct dlm_lock_resource *res,
311 struct dlm_lock *lock,
312 struct dlm_lockstatus *lksb,
313 int flags,
314 u8 owner)
315 {
316 struct dlm_unlock_lock unlock;
317 int tmpret;
318 enum dlm_status ret;
319 int status = 0;
320 struct kvec vec[2];
321 size_t veclen = 1;
322
323 mlog(0, "%.*s\n", res->lockname.len, res->lockname.name);
324
325 if (owner == dlm->node_num) {
326 /* ended up trying to contact ourself. this means
327 * that the lockres had been remote but became local
328 * via a migration. just retry it, now as local */
329 mlog(0, "%s:%.*s: this node became the master due to a "
330 "migration, re-evaluate now\n", dlm->name,
331 res->lockname.len, res->lockname.name);
332 return DLM_FORWARD;
333 }
334
335 memset(&unlock, 0, sizeof(unlock));
336 unlock.node_idx = dlm->node_num;
337 unlock.flags = cpu_to_be32(flags);
338 unlock.cookie = lock->ml.cookie;
339 unlock.namelen = res->lockname.len;
340 memcpy(unlock.name, res->lockname.name, unlock.namelen);
341
342 vec[0].iov_len = sizeof(struct dlm_unlock_lock);
343 vec[0].iov_base = &unlock;
344
345 if (flags & LKM_PUT_LVB) {
346 /* extra data to send if we are updating lvb */
347 vec[1].iov_len = DLM_LVB_LEN;
348 vec[1].iov_base = lock->lksb->lvb;
349 veclen++;
350 }
351
352 tmpret = o2net_send_message_vec(DLM_UNLOCK_LOCK_MSG, dlm->key,
353 vec, veclen, owner, &status);
354 if (tmpret >= 0) {
355 // successfully sent and received
356 if (status == DLM_FORWARD)
357 mlog(0, "master was in-progress. retry\n");
358 ret = status;
359 } else {
360 mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to "
361 "node %u\n", tmpret, DLM_UNLOCK_LOCK_MSG, dlm->key, owner);
362 if (dlm_is_host_down(tmpret)) {
363 /* NOTE: this seems strange, but it is what we want.
364 * when the master goes down during a cancel or
365 * unlock, the recovery code completes the operation
366 * as if the master had not died, then passes the
367 * updated state to the recovery master. this thread
368 * just needs to finish out the operation and call
369 * the unlockast. */
370 if (dlm_is_node_dead(dlm, owner))
371 ret = DLM_NORMAL;
372 else
373 ret = DLM_NOLOCKMGR;
374 } else {
375 /* something bad. this will BUG in ocfs2 */
376 ret = dlm_err_to_dlm_status(tmpret);
377 }
378 }
379
380 return ret;
381 }
382
383 /*
384 * locking:
385 * caller needs: none
386 * taken: takes and drops res->spinlock
387 * held on exit: none
388 * returns: DLM_NORMAL, DLM_BADARGS, DLM_IVLOCKID,
389 * return value from dlmunlock_master
390 */
dlm_unlock_lock_handler(struct o2net_msg * msg,u32 len,void * data,void ** ret_data)391 int dlm_unlock_lock_handler(struct o2net_msg *msg, u32 len, void *data,
392 void **ret_data)
393 {
394 struct dlm_ctxt *dlm = data;
395 struct dlm_unlock_lock *unlock = (struct dlm_unlock_lock *)msg->buf;
396 struct dlm_lock_resource *res = NULL;
397 struct dlm_lock *lock = NULL;
398 enum dlm_status status = DLM_NORMAL;
399 int found = 0, i;
400 struct dlm_lockstatus *lksb = NULL;
401 int ignore;
402 u32 flags;
403 struct list_head *queue;
404
405 flags = be32_to_cpu(unlock->flags);
406
407 if (flags & LKM_GET_LVB) {
408 mlog(ML_ERROR, "bad args! GET_LVB specified on unlock!\n");
409 return DLM_BADARGS;
410 }
411
412 if ((flags & (LKM_PUT_LVB|LKM_CANCEL)) == (LKM_PUT_LVB|LKM_CANCEL)) {
413 mlog(ML_ERROR, "bad args! cannot modify lvb on a CANCEL "
414 "request!\n");
415 return DLM_BADARGS;
416 }
417
418 if (unlock->namelen > DLM_LOCKID_NAME_MAX) {
419 mlog(ML_ERROR, "Invalid name length in unlock handler!\n");
420 return DLM_IVBUFLEN;
421 }
422
423 if (!dlm_grab(dlm))
424 return DLM_FORWARD;
425
426 mlog_bug_on_msg(!dlm_domain_fully_joined(dlm),
427 "Domain %s not fully joined!\n", dlm->name);
428
429 mlog(0, "lvb: %s\n", flags & LKM_PUT_LVB ? "put lvb" : "none");
430
431 res = dlm_lookup_lockres(dlm, unlock->name, unlock->namelen);
432 if (!res) {
433 /* We assume here that a no lock resource simply means
434 * it was migrated away and destroyed before the other
435 * node could detect it. */
436 mlog(0, "returning DLM_FORWARD -- res no longer exists\n");
437 status = DLM_FORWARD;
438 goto not_found;
439 }
440
441 queue=&res->granted;
442 found = 0;
443 spin_lock(&res->spinlock);
444 if (res->state & DLM_LOCK_RES_RECOVERING) {
445 spin_unlock(&res->spinlock);
446 mlog(0, "returning DLM_RECOVERING\n");
447 status = DLM_RECOVERING;
448 goto leave;
449 }
450
451 if (res->state & DLM_LOCK_RES_MIGRATING) {
452 spin_unlock(&res->spinlock);
453 mlog(0, "returning DLM_MIGRATING\n");
454 status = DLM_MIGRATING;
455 goto leave;
456 }
457
458 if (res->owner != dlm->node_num) {
459 spin_unlock(&res->spinlock);
460 mlog(0, "returning DLM_FORWARD -- not master\n");
461 status = DLM_FORWARD;
462 goto leave;
463 }
464
465 for (i=0; i<3; i++) {
466 list_for_each_entry(lock, queue, list) {
467 if (lock->ml.cookie == unlock->cookie &&
468 lock->ml.node == unlock->node_idx) {
469 dlm_lock_get(lock);
470 found = 1;
471 break;
472 }
473 }
474 if (found)
475 break;
476 /* scan granted -> converting -> blocked queues */
477 queue++;
478 }
479 spin_unlock(&res->spinlock);
480 if (!found) {
481 status = DLM_IVLOCKID;
482 goto not_found;
483 }
484
485 /* lock was found on queue */
486 lksb = lock->lksb;
487 if (flags & (LKM_VALBLK|LKM_PUT_LVB) &&
488 lock->ml.type != LKM_EXMODE)
489 flags &= ~(LKM_VALBLK|LKM_PUT_LVB);
490
491 /* unlockast only called on originating node */
492 if (flags & LKM_PUT_LVB) {
493 lksb->flags |= DLM_LKSB_PUT_LVB;
494 memcpy(&lksb->lvb[0], &unlock->lvb[0], DLM_LVB_LEN);
495 }
496
497 /* if this is in-progress, propagate the DLM_FORWARD
498 * all the way back out */
499 status = dlmunlock_master(dlm, res, lock, lksb, flags, &ignore);
500 if (status == DLM_FORWARD)
501 mlog(0, "lockres is in progress\n");
502
503 if (flags & LKM_PUT_LVB)
504 lksb->flags &= ~DLM_LKSB_PUT_LVB;
505
506 dlm_lockres_calc_usage(dlm, res);
507 dlm_kick_thread(dlm, res);
508
509 not_found:
510 if (!found)
511 mlog(ML_ERROR, "failed to find lock to unlock! "
512 "cookie=%u:%llu\n",
513 dlm_get_lock_cookie_node(be64_to_cpu(unlock->cookie)),
514 dlm_get_lock_cookie_seq(be64_to_cpu(unlock->cookie)));
515 else
516 dlm_lock_put(lock);
517
518 leave:
519 if (res)
520 dlm_lockres_put(res);
521
522 dlm_put(dlm);
523
524 return status;
525 }
526
527
dlm_get_cancel_actions(struct dlm_ctxt * dlm,struct dlm_lock_resource * res,struct dlm_lock * lock,struct dlm_lockstatus * lksb,int * actions)528 static enum dlm_status dlm_get_cancel_actions(struct dlm_ctxt *dlm,
529 struct dlm_lock_resource *res,
530 struct dlm_lock *lock,
531 struct dlm_lockstatus *lksb,
532 int *actions)
533 {
534 enum dlm_status status;
535
536 if (dlm_lock_on_list(&res->blocked, lock)) {
537 /* cancel this outright */
538 status = DLM_NORMAL;
539 *actions = (DLM_UNLOCK_CALL_AST |
540 DLM_UNLOCK_REMOVE_LOCK);
541 } else if (dlm_lock_on_list(&res->converting, lock)) {
542 /* cancel the request, put back on granted */
543 status = DLM_NORMAL;
544 *actions = (DLM_UNLOCK_CALL_AST |
545 DLM_UNLOCK_REMOVE_LOCK |
546 DLM_UNLOCK_REGRANT_LOCK |
547 DLM_UNLOCK_CLEAR_CONVERT_TYPE);
548 } else if (dlm_lock_on_list(&res->granted, lock)) {
549 /* too late, already granted. */
550 status = DLM_CANCELGRANT;
551 *actions = DLM_UNLOCK_CALL_AST;
552 } else {
553 mlog(ML_ERROR, "lock to cancel is not on any list!\n");
554 status = DLM_IVLOCKID;
555 *actions = 0;
556 }
557 return status;
558 }
559
dlm_get_unlock_actions(struct dlm_ctxt * dlm,struct dlm_lock_resource * res,struct dlm_lock * lock,struct dlm_lockstatus * lksb,int * actions)560 static enum dlm_status dlm_get_unlock_actions(struct dlm_ctxt *dlm,
561 struct dlm_lock_resource *res,
562 struct dlm_lock *lock,
563 struct dlm_lockstatus *lksb,
564 int *actions)
565 {
566 enum dlm_status status;
567
568 /* unlock request */
569 if (!dlm_lock_on_list(&res->granted, lock)) {
570 status = DLM_DENIED;
571 dlm_error(status);
572 *actions = 0;
573 } else {
574 /* unlock granted lock */
575 status = DLM_NORMAL;
576 *actions = (DLM_UNLOCK_FREE_LOCK |
577 DLM_UNLOCK_CALL_AST |
578 DLM_UNLOCK_REMOVE_LOCK);
579 }
580 return status;
581 }
582
583 /* there seems to be no point in doing this async
584 * since (even for the remote case) there is really
585 * no work to queue up... so just do it and fire the
586 * unlockast by hand when done... */
dlmunlock(struct dlm_ctxt * dlm,struct dlm_lockstatus * lksb,int flags,dlm_astunlockfunc_t * unlockast,void * data)587 enum dlm_status dlmunlock(struct dlm_ctxt *dlm, struct dlm_lockstatus *lksb,
588 int flags, dlm_astunlockfunc_t *unlockast, void *data)
589 {
590 enum dlm_status status;
591 struct dlm_lock_resource *res;
592 struct dlm_lock *lock = NULL;
593 int call_ast, is_master;
594
595 if (!lksb) {
596 dlm_error(DLM_BADARGS);
597 return DLM_BADARGS;
598 }
599
600 if (flags & ~(LKM_CANCEL | LKM_VALBLK | LKM_INVVALBLK)) {
601 dlm_error(DLM_BADPARAM);
602 return DLM_BADPARAM;
603 }
604
605 if ((flags & (LKM_VALBLK | LKM_CANCEL)) == (LKM_VALBLK | LKM_CANCEL)) {
606 mlog(0, "VALBLK given with CANCEL: ignoring VALBLK\n");
607 flags &= ~LKM_VALBLK;
608 }
609
610 if (!lksb->lockid || !lksb->lockid->lockres) {
611 dlm_error(DLM_BADPARAM);
612 return DLM_BADPARAM;
613 }
614
615 lock = lksb->lockid;
616 BUG_ON(!lock);
617 dlm_lock_get(lock);
618
619 res = lock->lockres;
620 BUG_ON(!res);
621 dlm_lockres_get(res);
622 retry:
623 call_ast = 0;
624 /* need to retry up here because owner may have changed */
625 mlog(0, "lock=%p res=%p\n", lock, res);
626
627 spin_lock(&res->spinlock);
628 is_master = (res->owner == dlm->node_num);
629 if (flags & LKM_VALBLK && lock->ml.type != LKM_EXMODE)
630 flags &= ~LKM_VALBLK;
631 spin_unlock(&res->spinlock);
632
633 if (is_master) {
634 status = dlmunlock_master(dlm, res, lock, lksb, flags,
635 &call_ast);
636 mlog(0, "done calling dlmunlock_master: returned %d, "
637 "call_ast is %d\n", status, call_ast);
638 } else {
639 status = dlmunlock_remote(dlm, res, lock, lksb, flags,
640 &call_ast);
641 mlog(0, "done calling dlmunlock_remote: returned %d, "
642 "call_ast is %d\n", status, call_ast);
643 }
644
645 if (status == DLM_RECOVERING ||
646 status == DLM_MIGRATING ||
647 status == DLM_FORWARD ||
648 status == DLM_NOLOCKMGR) {
649
650 /* We want to go away for a tiny bit to allow recovery
651 * / migration to complete on this resource. I don't
652 * know of any wait queue we could sleep on as this
653 * may be happening on another node. Perhaps the
654 * proper solution is to queue up requests on the
655 * other end? */
656
657 /* do we want to yield(); ?? */
658 msleep(50);
659
660 mlog(0, "retrying unlock due to pending recovery/"
661 "migration/in-progress/reconnect\n");
662 goto retry;
663 }
664
665 if (call_ast) {
666 mlog(0, "calling unlockast(%p, %d)\n", data, status);
667 if (is_master) {
668 /* it is possible that there is one last bast
669 * pending. make sure it is flushed, then
670 * call the unlockast.
671 * not an issue if this is a mastered remotely,
672 * since this lock has been removed from the
673 * lockres queues and cannot be found. */
674 dlm_kick_thread(dlm, NULL);
675 wait_event(dlm->ast_wq,
676 dlm_lock_basts_flushed(dlm, lock));
677 }
678 (*unlockast)(data, status);
679 }
680
681 if (status == DLM_CANCELGRANT)
682 status = DLM_NORMAL;
683
684 if (status == DLM_NORMAL) {
685 mlog(0, "kicking the thread\n");
686 dlm_kick_thread(dlm, res);
687 } else
688 dlm_error(status);
689
690 dlm_lockres_calc_usage(dlm, res);
691 dlm_lockres_put(res);
692 dlm_lock_put(lock);
693
694 mlog(0, "returning status=%d!\n", status);
695 return status;
696 }
697 EXPORT_SYMBOL_GPL(dlmunlock);
698
699