Merge branch 'intx' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/misc-2.6
[pandora-kernel.git] / fs / dlm / recover.c
1 /******************************************************************************
2 *******************************************************************************
3 **
4 **  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
5 **  Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
6 **
7 **  This copyrighted material is made available to anyone wishing to use,
8 **  modify, copy, or redistribute it subject to the terms and conditions
9 **  of the GNU General Public License v.2.
10 **
11 *******************************************************************************
12 ******************************************************************************/
13
14 #include "dlm_internal.h"
15 #include "lockspace.h"
16 #include "dir.h"
17 #include "config.h"
18 #include "ast.h"
19 #include "memory.h"
20 #include "rcom.h"
21 #include "lock.h"
22 #include "lowcomms.h"
23 #include "member.h"
24 #include "recover.h"
25
26
27 /*
28  * Recovery waiting routines: these functions wait for a particular reply from
29  * a remote node, or for the remote node to report a certain status.  They need
30  * to abort if the lockspace is stopped indicating a node has failed (perhaps
31  * the one being waited for).
32  */
33
34 /*
35  * Wait until given function returns non-zero or lockspace is stopped
36  * (LS_RECOVERY_STOP set due to failure of a node in ls_nodes).  When another
37  * function thinks it could have completed the waited-on task, they should wake
38  * up ls_wait_general to get an immediate response rather than waiting for the
39  * timer to detect the result.  A timer wakes us up periodically while waiting
40  * to see if we should abort due to a node failure.  This should only be called
41  * by the dlm_recoverd thread.
42  */
43
44 static void dlm_wait_timer_fn(unsigned long data)
45 {
46         struct dlm_ls *ls = (struct dlm_ls *) data;
47         mod_timer(&ls->ls_timer, jiffies + (dlm_config.recover_timer * HZ));
48         wake_up(&ls->ls_wait_general);
49 }
50
51 int dlm_wait_function(struct dlm_ls *ls, int (*testfn) (struct dlm_ls *ls))
52 {
53         int error = 0;
54
55         init_timer(&ls->ls_timer);
56         ls->ls_timer.function = dlm_wait_timer_fn;
57         ls->ls_timer.data = (long) ls;
58         ls->ls_timer.expires = jiffies + (dlm_config.recover_timer * HZ);
59         add_timer(&ls->ls_timer);
60
61         wait_event(ls->ls_wait_general, testfn(ls) || dlm_recovery_stopped(ls));
62         del_timer_sync(&ls->ls_timer);
63
64         if (dlm_recovery_stopped(ls)) {
65                 log_debug(ls, "dlm_wait_function aborted");
66                 error = -EINTR;
67         }
68         return error;
69 }
70
71 /*
72  * An efficient way for all nodes to wait for all others to have a certain
73  * status.  The node with the lowest nodeid polls all the others for their
74  * status (wait_status_all) and all the others poll the node with the low id
75  * for its accumulated result (wait_status_low).  When all nodes have set
76  * status flag X, then status flag X_ALL will be set on the low nodeid.
77  */
78
79 uint32_t dlm_recover_status(struct dlm_ls *ls)
80 {
81         uint32_t status;
82         spin_lock(&ls->ls_recover_lock);
83         status = ls->ls_recover_status;
84         spin_unlock(&ls->ls_recover_lock);
85         return status;
86 }
87
88 void dlm_set_recover_status(struct dlm_ls *ls, uint32_t status)
89 {
90         spin_lock(&ls->ls_recover_lock);
91         ls->ls_recover_status |= status;
92         spin_unlock(&ls->ls_recover_lock);
93 }
94
95 static int wait_status_all(struct dlm_ls *ls, uint32_t wait_status)
96 {
97         struct dlm_rcom *rc = (struct dlm_rcom *) ls->ls_recover_buf;
98         struct dlm_member *memb;
99         int error = 0, delay;
100
101         list_for_each_entry(memb, &ls->ls_nodes, list) {
102                 delay = 0;
103                 for (;;) {
104                         if (dlm_recovery_stopped(ls)) {
105                                 error = -EINTR;
106                                 goto out;
107                         }
108
109                         error = dlm_rcom_status(ls, memb->nodeid);
110                         if (error)
111                                 goto out;
112
113                         if (rc->rc_result & wait_status)
114                                 break;
115                         if (delay < 1000)
116                                 delay += 20;
117                         msleep(delay);
118                 }
119         }
120  out:
121         return error;
122 }
123
124 static int wait_status_low(struct dlm_ls *ls, uint32_t wait_status)
125 {
126         struct dlm_rcom *rc = (struct dlm_rcom *) ls->ls_recover_buf;
127         int error = 0, delay = 0, nodeid = ls->ls_low_nodeid;
128
129         for (;;) {
130                 if (dlm_recovery_stopped(ls)) {
131                         error = -EINTR;
132                         goto out;
133                 }
134
135                 error = dlm_rcom_status(ls, nodeid);
136                 if (error)
137                         break;
138
139                 if (rc->rc_result & wait_status)
140                         break;
141                 if (delay < 1000)
142                         delay += 20;
143                 msleep(delay);
144         }
145  out:
146         return error;
147 }
148
149 static int wait_status(struct dlm_ls *ls, uint32_t status)
150 {
151         uint32_t status_all = status << 1;
152         int error;
153
154         if (ls->ls_low_nodeid == dlm_our_nodeid()) {
155                 error = wait_status_all(ls, status);
156                 if (!error)
157                         dlm_set_recover_status(ls, status_all);
158         } else
159                 error = wait_status_low(ls, status_all);
160
161         return error;
162 }
163
164 int dlm_recover_members_wait(struct dlm_ls *ls)
165 {
166         return wait_status(ls, DLM_RS_NODES);
167 }
168
169 int dlm_recover_directory_wait(struct dlm_ls *ls)
170 {
171         return wait_status(ls, DLM_RS_DIR);
172 }
173
174 int dlm_recover_locks_wait(struct dlm_ls *ls)
175 {
176         return wait_status(ls, DLM_RS_LOCKS);
177 }
178
179 int dlm_recover_done_wait(struct dlm_ls *ls)
180 {
181         return wait_status(ls, DLM_RS_DONE);
182 }
183
184 /*
185  * The recover_list contains all the rsb's for which we've requested the new
186  * master nodeid.  As replies are returned from the resource directories the
187  * rsb's are removed from the list.  When the list is empty we're done.
188  *
189  * The recover_list is later similarly used for all rsb's for which we've sent
190  * new lkb's and need to receive new corresponding lkid's.
191  *
192  * We use the address of the rsb struct as a simple local identifier for the
193  * rsb so we can match an rcom reply with the rsb it was sent for.
194  */
195
196 static int recover_list_empty(struct dlm_ls *ls)
197 {
198         int empty;
199
200         spin_lock(&ls->ls_recover_list_lock);
201         empty = list_empty(&ls->ls_recover_list);
202         spin_unlock(&ls->ls_recover_list_lock);
203
204         return empty;
205 }
206
207 static void recover_list_add(struct dlm_rsb *r)
208 {
209         struct dlm_ls *ls = r->res_ls;
210
211         spin_lock(&ls->ls_recover_list_lock);
212         if (list_empty(&r->res_recover_list)) {
213                 list_add_tail(&r->res_recover_list, &ls->ls_recover_list);
214                 ls->ls_recover_list_count++;
215                 dlm_hold_rsb(r);
216         }
217         spin_unlock(&ls->ls_recover_list_lock);
218 }
219
220 static void recover_list_del(struct dlm_rsb *r)
221 {
222         struct dlm_ls *ls = r->res_ls;
223
224         spin_lock(&ls->ls_recover_list_lock);
225         list_del_init(&r->res_recover_list);
226         ls->ls_recover_list_count--;
227         spin_unlock(&ls->ls_recover_list_lock);
228
229         dlm_put_rsb(r);
230 }
231
232 static struct dlm_rsb *recover_list_find(struct dlm_ls *ls, uint64_t id)
233 {
234         struct dlm_rsb *r = NULL;
235
236         spin_lock(&ls->ls_recover_list_lock);
237
238         list_for_each_entry(r, &ls->ls_recover_list, res_recover_list) {
239                 if (id == (unsigned long) r)
240                         goto out;
241         }
242         r = NULL;
243  out:
244         spin_unlock(&ls->ls_recover_list_lock);
245         return r;
246 }
247
248 static void recover_list_clear(struct dlm_ls *ls)
249 {
250         struct dlm_rsb *r, *s;
251
252         spin_lock(&ls->ls_recover_list_lock);
253         list_for_each_entry_safe(r, s, &ls->ls_recover_list, res_recover_list) {
254                 list_del_init(&r->res_recover_list);
255                 r->res_recover_locks_count = 0;
256                 dlm_put_rsb(r);
257                 ls->ls_recover_list_count--;
258         }
259
260         if (ls->ls_recover_list_count != 0) {
261                 log_error(ls, "warning: recover_list_count %d",
262                           ls->ls_recover_list_count);
263                 ls->ls_recover_list_count = 0;
264         }
265         spin_unlock(&ls->ls_recover_list_lock);
266 }
267
268
269 /* Master recovery: find new master node for rsb's that were
270    mastered on nodes that have been removed.
271
272    dlm_recover_masters
273    recover_master
274    dlm_send_rcom_lookup            ->  receive_rcom_lookup
275                                        dlm_dir_lookup
276    receive_rcom_lookup_reply       <-
277    dlm_recover_master_reply
278    set_new_master
279    set_master_lkbs
280    set_lock_master
281 */
282
283 /*
284  * Set the lock master for all LKBs in a lock queue
285  * If we are the new master of the rsb, we may have received new
286  * MSTCPY locks from other nodes already which we need to ignore
287  * when setting the new nodeid.
288  */
289
290 static void set_lock_master(struct list_head *queue, int nodeid)
291 {
292         struct dlm_lkb *lkb;
293
294         list_for_each_entry(lkb, queue, lkb_statequeue)
295                 if (!(lkb->lkb_flags & DLM_IFL_MSTCPY))
296                         lkb->lkb_nodeid = nodeid;
297 }
298
299 static void set_master_lkbs(struct dlm_rsb *r)
300 {
301         set_lock_master(&r->res_grantqueue, r->res_nodeid);
302         set_lock_master(&r->res_convertqueue, r->res_nodeid);
303         set_lock_master(&r->res_waitqueue, r->res_nodeid);
304 }
305
306 /*
307  * Propogate the new master nodeid to locks
308  * The NEW_MASTER flag tells dlm_recover_locks() which rsb's to consider.
309  * The NEW_MASTER2 flag tells recover_lvb() and set_locks_purged() which
310  * rsb's to consider.
311  */
312
313 static void set_new_master(struct dlm_rsb *r, int nodeid)
314 {
315         lock_rsb(r);
316         r->res_nodeid = nodeid;
317         set_master_lkbs(r);
318         rsb_set_flag(r, RSB_NEW_MASTER);
319         rsb_set_flag(r, RSB_NEW_MASTER2);
320         unlock_rsb(r);
321 }
322
323 /*
324  * We do async lookups on rsb's that need new masters.  The rsb's
325  * waiting for a lookup reply are kept on the recover_list.
326  */
327
328 static int recover_master(struct dlm_rsb *r)
329 {
330         struct dlm_ls *ls = r->res_ls;
331         int error, dir_nodeid, ret_nodeid, our_nodeid = dlm_our_nodeid();
332
333         dir_nodeid = dlm_dir_nodeid(r);
334
335         if (dir_nodeid == our_nodeid) {
336                 error = dlm_dir_lookup(ls, our_nodeid, r->res_name,
337                                        r->res_length, &ret_nodeid);
338                 if (error)
339                         log_error(ls, "recover dir lookup error %d", error);
340
341                 if (ret_nodeid == our_nodeid)
342                         ret_nodeid = 0;
343                 set_new_master(r, ret_nodeid);
344         } else {
345                 recover_list_add(r);
346                 error = dlm_send_rcom_lookup(r, dir_nodeid);
347         }
348
349         return error;
350 }
351
352 /*
353  * When not using a directory, most resource names will hash to a new static
354  * master nodeid and the resource will need to be remastered.
355  */
356
357 static int recover_master_static(struct dlm_rsb *r)
358 {
359         int master = dlm_dir_nodeid(r);
360
361         if (master == dlm_our_nodeid())
362                 master = 0;
363
364         if (r->res_nodeid != master) {
365                 if (is_master(r))
366                         dlm_purge_mstcpy_locks(r);
367                 set_new_master(r, master);
368                 return 1;
369         }
370         return 0;
371 }
372
373 /*
374  * Go through local root resources and for each rsb which has a master which
375  * has departed, get the new master nodeid from the directory.  The dir will
376  * assign mastery to the first node to look up the new master.  That means
377  * we'll discover in this lookup if we're the new master of any rsb's.
378  *
379  * We fire off all the dir lookup requests individually and asynchronously to
380  * the correct dir node.
381  */
382
383 int dlm_recover_masters(struct dlm_ls *ls)
384 {
385         struct dlm_rsb *r;
386         int error = 0, count = 0;
387
388         log_debug(ls, "dlm_recover_masters");
389
390         down_read(&ls->ls_root_sem);
391         list_for_each_entry(r, &ls->ls_root_list, res_root_list) {
392                 if (dlm_recovery_stopped(ls)) {
393                         up_read(&ls->ls_root_sem);
394                         error = -EINTR;
395                         goto out;
396                 }
397
398                 if (dlm_no_directory(ls))
399                         count += recover_master_static(r);
400                 else if (!is_master(r) && dlm_is_removed(ls, r->res_nodeid)) {
401                         recover_master(r);
402                         count++;
403                 }
404
405                 schedule();
406         }
407         up_read(&ls->ls_root_sem);
408
409         log_debug(ls, "dlm_recover_masters %d resources", count);
410
411         error = dlm_wait_function(ls, &recover_list_empty);
412  out:
413         if (error)
414                 recover_list_clear(ls);
415         return error;
416 }
417
418 int dlm_recover_master_reply(struct dlm_ls *ls, struct dlm_rcom *rc)
419 {
420         struct dlm_rsb *r;
421         int nodeid;
422
423         r = recover_list_find(ls, rc->rc_id);
424         if (!r) {
425                 log_error(ls, "dlm_recover_master_reply no id %llx",
426                           (unsigned long long)rc->rc_id);
427                 goto out;
428         }
429
430         nodeid = rc->rc_result;
431         if (nodeid == dlm_our_nodeid())
432                 nodeid = 0;
433
434         set_new_master(r, nodeid);
435         recover_list_del(r);
436
437         if (recover_list_empty(ls))
438                 wake_up(&ls->ls_wait_general);
439  out:
440         return 0;
441 }
442
443
444 /* Lock recovery: rebuild the process-copy locks we hold on a
445    remastered rsb on the new rsb master.
446
447    dlm_recover_locks
448    recover_locks
449    recover_locks_queue
450    dlm_send_rcom_lock              ->  receive_rcom_lock
451                                        dlm_recover_master_copy
452    receive_rcom_lock_reply         <-
453    dlm_recover_process_copy
454 */
455
456
457 /*
458  * keep a count of the number of lkb's we send to the new master; when we get
459  * an equal number of replies then recovery for the rsb is done
460  */
461
462 static int recover_locks_queue(struct dlm_rsb *r, struct list_head *head)
463 {
464         struct dlm_lkb *lkb;
465         int error = 0;
466
467         list_for_each_entry(lkb, head, lkb_statequeue) {
468                 error = dlm_send_rcom_lock(r, lkb);
469                 if (error)
470                         break;
471                 r->res_recover_locks_count++;
472         }
473
474         return error;
475 }
476
477 static int recover_locks(struct dlm_rsb *r)
478 {
479         int error = 0;
480
481         lock_rsb(r);
482
483         DLM_ASSERT(!r->res_recover_locks_count, dlm_dump_rsb(r););
484
485         error = recover_locks_queue(r, &r->res_grantqueue);
486         if (error)
487                 goto out;
488         error = recover_locks_queue(r, &r->res_convertqueue);
489         if (error)
490                 goto out;
491         error = recover_locks_queue(r, &r->res_waitqueue);
492         if (error)
493                 goto out;
494
495         if (r->res_recover_locks_count)
496                 recover_list_add(r);
497         else
498                 rsb_clear_flag(r, RSB_NEW_MASTER);
499  out:
500         unlock_rsb(r);
501         return error;
502 }
503
504 int dlm_recover_locks(struct dlm_ls *ls)
505 {
506         struct dlm_rsb *r;
507         int error, count = 0;
508
509         log_debug(ls, "dlm_recover_locks");
510
511         down_read(&ls->ls_root_sem);
512         list_for_each_entry(r, &ls->ls_root_list, res_root_list) {
513                 if (is_master(r)) {
514                         rsb_clear_flag(r, RSB_NEW_MASTER);
515                         continue;
516                 }
517
518                 if (!rsb_flag(r, RSB_NEW_MASTER))
519                         continue;
520
521                 if (dlm_recovery_stopped(ls)) {
522                         error = -EINTR;
523                         up_read(&ls->ls_root_sem);
524                         goto out;
525                 }
526
527                 error = recover_locks(r);
528                 if (error) {
529                         up_read(&ls->ls_root_sem);
530                         goto out;
531                 }
532
533                 count += r->res_recover_locks_count;
534         }
535         up_read(&ls->ls_root_sem);
536
537         log_debug(ls, "dlm_recover_locks %d locks", count);
538
539         error = dlm_wait_function(ls, &recover_list_empty);
540  out:
541         if (error)
542                 recover_list_clear(ls);
543         else
544                 dlm_set_recover_status(ls, DLM_RS_LOCKS);
545         return error;
546 }
547
548 void dlm_recovered_lock(struct dlm_rsb *r)
549 {
550         DLM_ASSERT(rsb_flag(r, RSB_NEW_MASTER), dlm_dump_rsb(r););
551
552         r->res_recover_locks_count--;
553         if (!r->res_recover_locks_count) {
554                 rsb_clear_flag(r, RSB_NEW_MASTER);
555                 recover_list_del(r);
556         }
557
558         if (recover_list_empty(r->res_ls))
559                 wake_up(&r->res_ls->ls_wait_general);
560 }
561
562 /*
563  * The lvb needs to be recovered on all master rsb's.  This includes setting
564  * the VALNOTVALID flag if necessary, and determining the correct lvb contents
565  * based on the lvb's of the locks held on the rsb.
566  *
567  * RSB_VALNOTVALID is set if there are only NL/CR locks on the rsb.  If it
568  * was already set prior to recovery, it's not cleared, regardless of locks.
569  *
570  * The LVB contents are only considered for changing when this is a new master
571  * of the rsb (NEW_MASTER2).  Then, the rsb's lvb is taken from any lkb with
572  * mode > CR.  If no lkb's exist with mode above CR, the lvb contents are taken
573  * from the lkb with the largest lvb sequence number.
574  */
575
576 static void recover_lvb(struct dlm_rsb *r)
577 {
578         struct dlm_lkb *lkb, *high_lkb = NULL;
579         uint32_t high_seq = 0;
580         int lock_lvb_exists = 0;
581         int big_lock_exists = 0;
582         int lvblen = r->res_ls->ls_lvblen;
583
584         list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue) {
585                 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
586                         continue;
587
588                 lock_lvb_exists = 1;
589
590                 if (lkb->lkb_grmode > DLM_LOCK_CR) {
591                         big_lock_exists = 1;
592                         goto setflag;
593                 }
594
595                 if (((int)lkb->lkb_lvbseq - (int)high_seq) >= 0) {
596                         high_lkb = lkb;
597                         high_seq = lkb->lkb_lvbseq;
598                 }
599         }
600
601         list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue) {
602                 if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
603                         continue;
604
605                 lock_lvb_exists = 1;
606
607                 if (lkb->lkb_grmode > DLM_LOCK_CR) {
608                         big_lock_exists = 1;
609                         goto setflag;
610                 }
611
612                 if (((int)lkb->lkb_lvbseq - (int)high_seq) >= 0) {
613                         high_lkb = lkb;
614                         high_seq = lkb->lkb_lvbseq;
615                 }
616         }
617
618  setflag:
619         if (!lock_lvb_exists)
620                 goto out;
621
622         if (!big_lock_exists)
623                 rsb_set_flag(r, RSB_VALNOTVALID);
624
625         /* don't mess with the lvb unless we're the new master */
626         if (!rsb_flag(r, RSB_NEW_MASTER2))
627                 goto out;
628
629         if (!r->res_lvbptr) {
630                 r->res_lvbptr = allocate_lvb(r->res_ls);
631                 if (!r->res_lvbptr)
632                         goto out;
633         }
634
635         if (big_lock_exists) {
636                 r->res_lvbseq = lkb->lkb_lvbseq;
637                 memcpy(r->res_lvbptr, lkb->lkb_lvbptr, lvblen);
638         } else if (high_lkb) {
639                 r->res_lvbseq = high_lkb->lkb_lvbseq;
640                 memcpy(r->res_lvbptr, high_lkb->lkb_lvbptr, lvblen);
641         } else {
642                 r->res_lvbseq = 0;
643                 memset(r->res_lvbptr, 0, lvblen);
644         }
645  out:
646         return;
647 }
648
649 /* All master rsb's flagged RECOVER_CONVERT need to be looked at.  The locks
650    converting PR->CW or CW->PR need to have their lkb_grmode set. */
651
652 static void recover_conversion(struct dlm_rsb *r)
653 {
654         struct dlm_lkb *lkb;
655         int grmode = -1;
656
657         list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue) {
658                 if (lkb->lkb_grmode == DLM_LOCK_PR ||
659                     lkb->lkb_grmode == DLM_LOCK_CW) {
660                         grmode = lkb->lkb_grmode;
661                         break;
662                 }
663         }
664
665         list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue) {
666                 if (lkb->lkb_grmode != DLM_LOCK_IV)
667                         continue;
668                 if (grmode == -1)
669                         lkb->lkb_grmode = lkb->lkb_rqmode;
670                 else
671                         lkb->lkb_grmode = grmode;
672         }
673 }
674
675 /* We've become the new master for this rsb and waiting/converting locks may
676    need to be granted in dlm_grant_after_purge() due to locks that may have
677    existed from a removed node. */
678
679 static void set_locks_purged(struct dlm_rsb *r)
680 {
681         if (!list_empty(&r->res_waitqueue) || !list_empty(&r->res_convertqueue))
682                 rsb_set_flag(r, RSB_LOCKS_PURGED);
683 }
684
685 void dlm_recover_rsbs(struct dlm_ls *ls)
686 {
687         struct dlm_rsb *r;
688         int count = 0;
689
690         log_debug(ls, "dlm_recover_rsbs");
691
692         down_read(&ls->ls_root_sem);
693         list_for_each_entry(r, &ls->ls_root_list, res_root_list) {
694                 lock_rsb(r);
695                 if (is_master(r)) {
696                         if (rsb_flag(r, RSB_RECOVER_CONVERT))
697                                 recover_conversion(r);
698                         if (rsb_flag(r, RSB_NEW_MASTER2))
699                                 set_locks_purged(r);
700                         recover_lvb(r);
701                         count++;
702                 }
703                 rsb_clear_flag(r, RSB_RECOVER_CONVERT);
704                 rsb_clear_flag(r, RSB_NEW_MASTER2);
705                 unlock_rsb(r);
706         }
707         up_read(&ls->ls_root_sem);
708
709         log_debug(ls, "dlm_recover_rsbs %d rsbs", count);
710 }
711
712 /* Create a single list of all root rsb's to be used during recovery */
713
714 int dlm_create_root_list(struct dlm_ls *ls)
715 {
716         struct dlm_rsb *r;
717         int i, error = 0;
718
719         down_write(&ls->ls_root_sem);
720         if (!list_empty(&ls->ls_root_list)) {
721                 log_error(ls, "root list not empty");
722                 error = -EINVAL;
723                 goto out;
724         }
725
726         for (i = 0; i < ls->ls_rsbtbl_size; i++) {
727                 read_lock(&ls->ls_rsbtbl[i].lock);
728                 list_for_each_entry(r, &ls->ls_rsbtbl[i].list, res_hashchain) {
729                         list_add(&r->res_root_list, &ls->ls_root_list);
730                         dlm_hold_rsb(r);
731                 }
732                 read_unlock(&ls->ls_rsbtbl[i].lock);
733         }
734  out:
735         up_write(&ls->ls_root_sem);
736         return error;
737 }
738
739 void dlm_release_root_list(struct dlm_ls *ls)
740 {
741         struct dlm_rsb *r, *safe;
742
743         down_write(&ls->ls_root_sem);
744         list_for_each_entry_safe(r, safe, &ls->ls_root_list, res_root_list) {
745                 list_del_init(&r->res_root_list);
746                 dlm_put_rsb(r);
747         }
748         up_write(&ls->ls_root_sem);
749 }
750
751 void dlm_clear_toss_list(struct dlm_ls *ls)
752 {
753         struct dlm_rsb *r, *safe;
754         int i;
755
756         for (i = 0; i < ls->ls_rsbtbl_size; i++) {
757                 write_lock(&ls->ls_rsbtbl[i].lock);
758                 list_for_each_entry_safe(r, safe, &ls->ls_rsbtbl[i].toss,
759                                          res_hashchain) {
760                         list_del(&r->res_hashchain);
761                         free_rsb(r);
762                 }
763                 write_unlock(&ls->ls_rsbtbl[i].lock);
764         }
765 }
766