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