[PATCH] OCFS2: The Second Oracle Cluster Filesystem
[linux-2.6.git] / fs / ocfs2 / dlm / dlmunlock.c
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/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 #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 #define MLOG_MASK_PREFIX ML_DLM
51 #include "cluster/masklog.h"
52
53 #define DLM_UNLOCK_FREE_LOCK           0x00000001
54 #define DLM_UNLOCK_CALL_AST            0x00000002
55 #define DLM_UNLOCK_REMOVE_LOCK         0x00000004
56 #define DLM_UNLOCK_REGRANT_LOCK        0x00000008
57 #define DLM_UNLOCK_CLEAR_CONVERT_TYPE  0x00000010
58
59
60 static enum dlm_status dlm_get_cancel_actions(struct dlm_ctxt *dlm,
61                                               struct dlm_lock_resource *res,
62                                               struct dlm_lock *lock,
63                                               struct dlm_lockstatus *lksb,
64                                               int *actions);
65 static enum dlm_status dlm_get_unlock_actions(struct dlm_ctxt *dlm,
66                                               struct dlm_lock_resource *res,
67                                               struct dlm_lock *lock,
68                                               struct dlm_lockstatus *lksb,
69                                               int *actions);
70
71 static enum dlm_status dlm_send_remote_unlock_request(struct dlm_ctxt *dlm,
72                                                  struct dlm_lock_resource *res,
73                                                  struct dlm_lock *lock,
74                                                  struct dlm_lockstatus *lksb,
75                                                  int flags,
76                                                  u8 owner);
77
78
79 /*
80  * according to the spec:
81  * http://opendlm.sourceforge.net/cvsmirror/opendlm/docs/dlmbook_final.pdf
82  *
83  *  flags & LKM_CANCEL != 0: must be converting or blocked
84  *  flags & LKM_CANCEL == 0: must be granted
85  *
86  * So to unlock a converting lock, you must first cancel the
87  * convert (passing LKM_CANCEL in flags), then call the unlock
88  * again (with no LKM_CANCEL in flags).
89  */
90
91
92 /*
93  * locking:
94  *   caller needs:  none
95  *   taken:         res->spinlock and lock->spinlock taken and dropped
96  *   held on exit:  none
97  * returns: DLM_NORMAL, DLM_NOLOCKMGR, status from network
98  * all callers should have taken an extra ref on lock coming in
99  */
100 static enum dlm_status dlmunlock_common(struct dlm_ctxt *dlm,
101                                         struct dlm_lock_resource *res,
102                                         struct dlm_lock *lock,
103                                         struct dlm_lockstatus *lksb,
104                                         int flags, int *call_ast,
105                                         int master_node)
106 {
107         enum dlm_status status;
108         int actions = 0;
109         int in_use;
110         u8 owner;
111
112         mlog(0, "master_node = %d, valblk = %d\n", master_node,
113              flags & LKM_VALBLK);
114
115         if (master_node)
116                 BUG_ON(res->owner != dlm->node_num);
117         else
118                 BUG_ON(res->owner == dlm->node_num);
119
120         spin_lock(&dlm->spinlock);
121         /* We want to be sure that we're not freeing a lock
122          * that still has AST's pending... */
123         in_use = !list_empty(&lock->ast_list);
124         spin_unlock(&dlm->spinlock);
125         if (in_use) {
126                mlog(ML_ERROR, "lockres %.*s: Someone is calling dlmunlock "
127                     "while waiting for an ast!", res->lockname.len,
128                     res->lockname.name);
129                 return DLM_BADPARAM;
130         }
131
132         spin_lock(&res->spinlock);
133         if (res->state & DLM_LOCK_RES_IN_PROGRESS) {
134                 if (master_node) {
135                         mlog(ML_ERROR, "lockres in progress!\n");
136                         spin_unlock(&res->spinlock);
137                         return DLM_FORWARD;
138                 }
139                 /* ok for this to sleep if not in a network handler */
140                 __dlm_wait_on_lockres(res);
141                 res->state |= DLM_LOCK_RES_IN_PROGRESS;
142         }
143         spin_lock(&lock->spinlock);
144
145         if (res->state & DLM_LOCK_RES_RECOVERING) {
146                 status = DLM_RECOVERING;
147                 goto leave;
148         }
149
150
151         /* see above for what the spec says about
152          * LKM_CANCEL and the lock queue state */
153         if (flags & LKM_CANCEL)
154                 status = dlm_get_cancel_actions(dlm, res, lock, lksb, &actions);
155         else
156                 status = dlm_get_unlock_actions(dlm, res, lock, lksb, &actions);
157
158         if (status != DLM_NORMAL)
159                 goto leave;
160
161         /* By now this has been masked out of cancel requests. */
162         if (flags & LKM_VALBLK) {
163                 /* make the final update to the lvb */
164                 if (master_node)
165                         memcpy(res->lvb, lksb->lvb, DLM_LVB_LEN);
166                 else
167                         flags |= LKM_PUT_LVB; /* let the send function
168                                                * handle it. */
169         }
170
171         if (!master_node) {
172                 owner = res->owner;
173                 /* drop locks and send message */
174                 if (flags & LKM_CANCEL)
175                         lock->cancel_pending = 1;
176                 else
177                         lock->unlock_pending = 1;
178                 spin_unlock(&lock->spinlock);
179                 spin_unlock(&res->spinlock);
180                 status = dlm_send_remote_unlock_request(dlm, res, lock, lksb,
181                                                         flags, owner);
182                 spin_lock(&res->spinlock);
183                 spin_lock(&lock->spinlock);
184                 /* if the master told us the lock was already granted,
185                  * let the ast handle all of these actions */
186                 if (status == DLM_NORMAL &&
187                     lksb->status == DLM_CANCELGRANT) {
188                         actions &= ~(DLM_UNLOCK_REMOVE_LOCK|
189                                      DLM_UNLOCK_REGRANT_LOCK|
190                                      DLM_UNLOCK_CLEAR_CONVERT_TYPE);
191                 }
192                 if (flags & LKM_CANCEL)
193                         lock->cancel_pending = 0;
194                 else
195                         lock->unlock_pending = 0;
196
197         }
198
199         /* get an extra ref on lock.  if we are just switching
200          * lists here, we dont want the lock to go away. */
201         dlm_lock_get(lock);
202
203         if (actions & DLM_UNLOCK_REMOVE_LOCK) {
204                 list_del_init(&lock->list);
205                 dlm_lock_put(lock);
206         }
207         if (actions & DLM_UNLOCK_REGRANT_LOCK) {
208                 dlm_lock_get(lock);
209                 list_add_tail(&lock->list, &res->granted);
210         }
211         if (actions & DLM_UNLOCK_CLEAR_CONVERT_TYPE) {
212                 mlog(0, "clearing convert_type at %smaster node\n",
213                      master_node ? "" : "non-");
214                 lock->ml.convert_type = LKM_IVMODE;
215         }
216
217         /* remove the extra ref on lock */
218         dlm_lock_put(lock);
219
220 leave:
221         res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
222         if (!dlm_lock_on_list(&res->converting, lock))
223                 BUG_ON(lock->ml.convert_type != LKM_IVMODE);
224         else
225                 BUG_ON(lock->ml.convert_type == LKM_IVMODE);
226         spin_unlock(&lock->spinlock);
227         spin_unlock(&res->spinlock);
228         wake_up(&res->wq);
229
230         /* let the caller's final dlm_lock_put handle the actual kfree */
231         if (actions & DLM_UNLOCK_FREE_LOCK) {
232                 /* this should always be coupled with list removal */
233                 BUG_ON(!(actions & DLM_UNLOCK_REMOVE_LOCK));
234                 mlog(0, "lock %"MLFu64" should be gone now! refs=%d\n",
235                      lock->ml.cookie, atomic_read(&lock->lock_refs.refcount)-1);
236                 dlm_lock_put(lock);
237         }
238         if (actions & DLM_UNLOCK_CALL_AST)
239                 *call_ast = 1;
240
241         /* if cancel or unlock succeeded, lvb work is done */
242         if (status == DLM_NORMAL)
243                 lksb->flags &= ~(DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB);
244
245         return status;
246 }
247
248 void dlm_commit_pending_unlock(struct dlm_lock_resource *res,
249                                struct dlm_lock *lock)
250 {
251         /* leave DLM_LKSB_PUT_LVB on the lksb so any final
252          * update of the lvb will be sent to the new master */
253         list_del_init(&lock->list);
254 }
255
256 void dlm_commit_pending_cancel(struct dlm_lock_resource *res,
257                                struct dlm_lock *lock)
258 {
259         list_del_init(&lock->list);
260         list_add_tail(&lock->list, &res->granted);
261         lock->ml.convert_type = LKM_IVMODE;
262 }
263
264
265 static inline enum dlm_status dlmunlock_master(struct dlm_ctxt *dlm,
266                                           struct dlm_lock_resource *res,
267                                           struct dlm_lock *lock,
268                                           struct dlm_lockstatus *lksb,
269                                           int flags,
270                                           int *call_ast)
271 {
272         return dlmunlock_common(dlm, res, lock, lksb, flags, call_ast, 1);
273 }
274
275 static inline enum dlm_status dlmunlock_remote(struct dlm_ctxt *dlm,
276                                           struct dlm_lock_resource *res,
277                                           struct dlm_lock *lock,
278                                           struct dlm_lockstatus *lksb,
279                                           int flags, int *call_ast)
280 {
281         return dlmunlock_common(dlm, res, lock, lksb, flags, call_ast, 0);
282 }
283
284 /*
285  * locking:
286  *   caller needs:  none
287  *   taken:         none
288  *   held on exit:  none
289  * returns: DLM_NORMAL, DLM_NOLOCKMGR, status from network
290  */
291 static enum dlm_status dlm_send_remote_unlock_request(struct dlm_ctxt *dlm,
292                                                  struct dlm_lock_resource *res,
293                                                  struct dlm_lock *lock,
294                                                  struct dlm_lockstatus *lksb,
295                                                  int flags,
296                                                  u8 owner)
297 {
298         struct dlm_unlock_lock unlock;
299         int tmpret;
300         enum dlm_status ret;
301         int status = 0;
302         struct kvec vec[2];
303         size_t veclen = 1;
304
305         mlog_entry("%.*s\n", res->lockname.len, res->lockname.name);
306
307         memset(&unlock, 0, sizeof(unlock));
308         unlock.node_idx = dlm->node_num;
309         unlock.flags = cpu_to_be32(flags);
310         unlock.cookie = lock->ml.cookie;
311         unlock.namelen = res->lockname.len;
312         memcpy(unlock.name, res->lockname.name, unlock.namelen);
313
314         vec[0].iov_len = sizeof(struct dlm_unlock_lock);
315         vec[0].iov_base = &unlock;
316
317         if (flags & LKM_PUT_LVB) {
318                 /* extra data to send if we are updating lvb */
319                 vec[1].iov_len = DLM_LVB_LEN;
320                 vec[1].iov_base = lock->lksb->lvb;
321                 veclen++;
322         }
323
324         tmpret = o2net_send_message_vec(DLM_UNLOCK_LOCK_MSG, dlm->key,
325                                         vec, veclen, owner, &status);
326         if (tmpret >= 0) {
327                 // successfully sent and received
328                 if (status == DLM_CANCELGRANT)
329                         ret = DLM_NORMAL;
330                 else if (status == DLM_FORWARD) {
331                         mlog(0, "master was in-progress.  retry\n");
332                         ret = DLM_FORWARD;
333                 } else
334                         ret = status;
335                 lksb->status = status;
336         } else {
337                 mlog_errno(tmpret);
338                 if (dlm_is_host_down(tmpret)) {
339                         /* NOTE: this seems strange, but it is what we want.
340                          * when the master goes down during a cancel or
341                          * unlock, the recovery code completes the operation
342                          * as if the master had not died, then passes the
343                          * updated state to the recovery master.  this thread
344                          * just needs to finish out the operation and call
345                          * the unlockast. */
346                         ret = DLM_NORMAL;
347                 } else {
348                         /* something bad.  this will BUG in ocfs2 */
349                         ret = dlm_err_to_dlm_status(tmpret);
350                 }
351                 lksb->status = ret;
352         }
353
354         return ret;
355 }
356
357 /*
358  * locking:
359  *   caller needs:  none
360  *   taken:         takes and drops res->spinlock
361  *   held on exit:  none
362  * returns: DLM_NORMAL, DLM_BADARGS, DLM_IVLOCKID,
363  *          return value from dlmunlock_master
364  */
365 int dlm_unlock_lock_handler(struct o2net_msg *msg, u32 len, void *data)
366 {
367         struct dlm_ctxt *dlm = data;
368         struct dlm_unlock_lock *unlock = (struct dlm_unlock_lock *)msg->buf;
369         struct dlm_lock_resource *res = NULL;
370         struct list_head *iter;
371         struct dlm_lock *lock = NULL;
372         enum dlm_status status = DLM_NORMAL;
373         int found = 0, i;
374         struct dlm_lockstatus *lksb = NULL;
375         int ignore;
376         u32 flags;
377         struct list_head *queue;
378
379         flags = be32_to_cpu(unlock->flags);
380
381         if (flags & LKM_GET_LVB) {
382                 mlog(ML_ERROR, "bad args!  GET_LVB specified on unlock!\n");
383                 return DLM_BADARGS;
384         }
385
386         if ((flags & (LKM_PUT_LVB|LKM_CANCEL)) == (LKM_PUT_LVB|LKM_CANCEL)) {
387                 mlog(ML_ERROR, "bad args!  cannot modify lvb on a CANCEL "
388                      "request!\n");
389                 return DLM_BADARGS;
390         }
391
392         if (unlock->namelen > DLM_LOCKID_NAME_MAX) {
393                 mlog(ML_ERROR, "Invalid name length in unlock handler!\n");
394                 return DLM_IVBUFLEN;
395         }
396
397         if (!dlm_grab(dlm))
398                 return DLM_REJECTED;
399
400         mlog_bug_on_msg(!dlm_domain_fully_joined(dlm),
401                         "Domain %s not fully joined!\n", dlm->name);
402
403         mlog(0, "lvb: %s\n", flags & LKM_PUT_LVB ? "put lvb" : "none");
404
405         res = dlm_lookup_lockres(dlm, unlock->name, unlock->namelen);
406         if (!res) {
407                 /* We assume here that a no lock resource simply means
408                  * it was migrated away and destroyed before the other
409                  * node could detect it. */
410                 mlog(0, "returning DLM_FORWARD -- res no longer exists\n");
411                 status = DLM_FORWARD;
412                 goto not_found;
413         }
414
415         queue=&res->granted;
416         found = 0;
417         spin_lock(&res->spinlock);
418         if (res->state & DLM_LOCK_RES_RECOVERING) {
419                 spin_unlock(&res->spinlock);
420                 mlog(0, "returning DLM_RECOVERING\n");
421                 status = DLM_RECOVERING;
422                 goto leave;
423         }
424
425         if (res->state & DLM_LOCK_RES_MIGRATING) {
426                 spin_unlock(&res->spinlock);
427                 mlog(0, "returning DLM_MIGRATING\n");
428                 status = DLM_MIGRATING;
429                 goto leave;
430         }
431
432         if (res->owner != dlm->node_num) {
433                 spin_unlock(&res->spinlock);
434                 mlog(0, "returning DLM_FORWARD -- not master\n");
435                 status = DLM_FORWARD;
436                 goto leave;
437         }
438
439         for (i=0; i<3; i++) {
440                 list_for_each(iter, queue) {
441                         lock = list_entry(iter, struct dlm_lock, list);
442                         if (lock->ml.cookie == unlock->cookie &&
443                             lock->ml.node == unlock->node_idx) {
444                                 dlm_lock_get(lock);
445                                 found = 1;
446                                 break;
447                         }
448                 }
449                 if (found)
450                         break;
451                 /* scan granted -> converting -> blocked queues */
452                 queue++;
453         }
454         spin_unlock(&res->spinlock);
455         if (!found) {
456                 status = DLM_IVLOCKID;
457                 goto not_found;
458         }
459
460         /* lock was found on queue */
461         lksb = lock->lksb;
462         /* unlockast only called on originating node */
463         if (flags & LKM_PUT_LVB) {
464                 lksb->flags |= DLM_LKSB_PUT_LVB;
465                 memcpy(&lksb->lvb[0], &unlock->lvb[0], DLM_LVB_LEN);
466         }
467
468         /* if this is in-progress, propagate the DLM_FORWARD
469          * all the way back out */
470         status = dlmunlock_master(dlm, res, lock, lksb, flags, &ignore);
471         if (status == DLM_FORWARD)
472                 mlog(0, "lockres is in progress\n");
473
474         if (flags & LKM_PUT_LVB)
475                 lksb->flags &= ~DLM_LKSB_PUT_LVB;
476
477         dlm_lockres_calc_usage(dlm, res);
478         dlm_kick_thread(dlm, res);
479
480 not_found:
481         if (!found)
482                 mlog(ML_ERROR, "failed to find lock to unlock! "
483                                "cookie=%"MLFu64"\n",
484                      unlock->cookie);
485         else {
486                 /* send the lksb->status back to the other node */
487                 status = lksb->status;
488                 dlm_lock_put(lock);
489         }
490
491 leave:
492         if (res)
493                 dlm_lockres_put(res);
494
495         dlm_put(dlm);
496
497         return status;
498 }
499
500
501 static enum dlm_status dlm_get_cancel_actions(struct dlm_ctxt *dlm,
502                                               struct dlm_lock_resource *res,
503                                               struct dlm_lock *lock,
504                                               struct dlm_lockstatus *lksb,
505                                               int *actions)
506 {
507         enum dlm_status status;
508
509         if (dlm_lock_on_list(&res->blocked, lock)) {
510                 /* cancel this outright */
511                 lksb->status = DLM_NORMAL;
512                 status = DLM_NORMAL;
513                 *actions = (DLM_UNLOCK_CALL_AST |
514                             DLM_UNLOCK_REMOVE_LOCK);
515         } else if (dlm_lock_on_list(&res->converting, lock)) {
516                 /* cancel the request, put back on granted */
517                 lksb->status = DLM_NORMAL;
518                 status = DLM_NORMAL;
519                 *actions = (DLM_UNLOCK_CALL_AST |
520                             DLM_UNLOCK_REMOVE_LOCK |
521                             DLM_UNLOCK_REGRANT_LOCK |
522                             DLM_UNLOCK_CLEAR_CONVERT_TYPE);
523         } else if (dlm_lock_on_list(&res->granted, lock)) {
524                 /* too late, already granted.  DLM_CANCELGRANT */
525                 lksb->status = DLM_CANCELGRANT;
526                 status = DLM_NORMAL;
527                 *actions = DLM_UNLOCK_CALL_AST;
528         } else {
529                 mlog(ML_ERROR, "lock to cancel is not on any list!\n");
530                 lksb->status = DLM_IVLOCKID;
531                 status = DLM_IVLOCKID;
532                 *actions = 0;
533         }
534         return status;
535 }
536
537 static enum dlm_status dlm_get_unlock_actions(struct dlm_ctxt *dlm,
538                                               struct dlm_lock_resource *res,
539                                               struct dlm_lock *lock,
540                                               struct dlm_lockstatus *lksb,
541                                               int *actions)
542 {
543         enum dlm_status status;
544
545         /* unlock request */
546         if (!dlm_lock_on_list(&res->granted, lock)) {
547                 lksb->status = DLM_DENIED;
548                 status = DLM_DENIED;
549                 dlm_error(status);
550                 *actions = 0;
551         } else {
552                 /* unlock granted lock */
553                 lksb->status = DLM_NORMAL;
554                 status = DLM_NORMAL;
555                 *actions = (DLM_UNLOCK_FREE_LOCK |
556                             DLM_UNLOCK_CALL_AST |
557                             DLM_UNLOCK_REMOVE_LOCK);
558         }
559         return status;
560 }
561
562 /* there seems to be no point in doing this async
563  * since (even for the remote case) there is really
564  * no work to queue up... so just do it and fire the
565  * unlockast by hand when done... */
566 enum dlm_status dlmunlock(struct dlm_ctxt *dlm, struct dlm_lockstatus *lksb,
567                           int flags, dlm_astunlockfunc_t *unlockast, void *data)
568 {
569         enum dlm_status status;
570         struct dlm_lock_resource *res;
571         struct dlm_lock *lock = NULL;
572         int call_ast, is_master;
573
574         mlog_entry_void();
575
576         if (!lksb) {
577                 dlm_error(DLM_BADARGS);
578                 return DLM_BADARGS;
579         }
580
581         if (flags & ~(LKM_CANCEL | LKM_VALBLK | LKM_INVVALBLK)) {
582                 dlm_error(DLM_BADPARAM);
583                 return DLM_BADPARAM;
584         }
585
586         if ((flags & (LKM_VALBLK | LKM_CANCEL)) == (LKM_VALBLK | LKM_CANCEL)) {
587                 mlog(0, "VALBLK given with CANCEL: ignoring VALBLK\n");
588                 flags &= ~LKM_VALBLK;
589         }
590
591         if (!lksb->lockid || !lksb->lockid->lockres) {
592                 dlm_error(DLM_BADPARAM);
593                 return DLM_BADPARAM;
594         }
595
596         lock = lksb->lockid;
597         BUG_ON(!lock);
598         dlm_lock_get(lock);
599
600         res = lock->lockres;
601         BUG_ON(!res);
602         dlm_lockres_get(res);
603 retry:
604         call_ast = 0;
605         /* need to retry up here because owner may have changed */
606         mlog(0, "lock=%p res=%p\n", lock, res);
607
608         spin_lock(&res->spinlock);
609         is_master = (res->owner == dlm->node_num);
610         spin_unlock(&res->spinlock);
611
612         if (is_master) {
613                 status = dlmunlock_master(dlm, res, lock, lksb, flags,
614                                           &call_ast);
615                 mlog(0, "done calling dlmunlock_master: returned %d, "
616                      "call_ast is %d\n", status, call_ast);
617         } else {
618                 status = dlmunlock_remote(dlm, res, lock, lksb, flags,
619                                           &call_ast);
620                 mlog(0, "done calling dlmunlock_remote: returned %d, "
621                      "call_ast is %d\n", status, call_ast);
622         }
623
624         if (status == DLM_RECOVERING ||
625             status == DLM_MIGRATING ||
626             status == DLM_FORWARD) {
627                 /* We want to go away for a tiny bit to allow recovery
628                  * / migration to complete on this resource. I don't
629                  * know of any wait queue we could sleep on as this
630                  * may be happening on another node. Perhaps the
631                  * proper solution is to queue up requests on the
632                  * other end? */
633
634                 /* do we want to yield(); ?? */
635                 msleep(50);
636
637                 mlog(0, "retrying unlock due to pending recovery/"
638                      "migration/in-progress\n");
639                 goto retry;
640         }
641
642         if (call_ast) {
643                 mlog(0, "calling unlockast(%p, %d)\n", data, lksb->status);
644                 if (is_master) {
645                         /* it is possible that there is one last bast 
646                          * pending.  make sure it is flushed, then
647                          * call the unlockast.
648                          * not an issue if this is a mastered remotely,
649                          * since this lock has been removed from the
650                          * lockres queues and cannot be found. */
651                         dlm_kick_thread(dlm, NULL);
652                         wait_event(dlm->ast_wq, 
653                                    dlm_lock_basts_flushed(dlm, lock));
654                 }
655                 (*unlockast)(data, lksb->status);
656         }
657
658         if (status == DLM_NORMAL) {
659                 mlog(0, "kicking the thread\n");
660                 dlm_kick_thread(dlm, res);
661         } else
662                 dlm_error(status);
663
664         dlm_lockres_calc_usage(dlm, res);
665         dlm_lockres_put(res);
666         dlm_lock_put(lock);
667
668         mlog(0, "returning status=%d!\n", status);
669         return status;
670 }
671 EXPORT_SYMBOL_GPL(dlmunlock);
672