Pull thermal into release branch
[linux-2.6] / fs / ocfs2 / dlm / dlmthread.c
1 /* -*- mode: c; c-basic-offset: 8; -*-
2  * vim: noexpandtab sw=8 ts=8 sts=0:
3  *
4  * dlmthread.c
5  *
6  * standalone DLM module
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/timer.h>
41 #include <linux/kthread.h>
42 #include <linux/delay.h>
43
44
45 #include "cluster/heartbeat.h"
46 #include "cluster/nodemanager.h"
47 #include "cluster/tcp.h"
48
49 #include "dlmapi.h"
50 #include "dlmcommon.h"
51 #include "dlmdomain.h"
52
53 #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_THREAD)
54 #include "cluster/masklog.h"
55
56 static int dlm_thread(void *data);
57 static void dlm_flush_asts(struct dlm_ctxt *dlm);
58
59 #define dlm_lock_is_remote(dlm, lock)     ((lock)->ml.node != (dlm)->node_num)
60
61 /* will exit holding res->spinlock, but may drop in function */
62 /* waits until flags are cleared on res->state */
63 void __dlm_wait_on_lockres_flags(struct dlm_lock_resource *res, int flags)
64 {
65         DECLARE_WAITQUEUE(wait, current);
66
67         assert_spin_locked(&res->spinlock);
68
69         add_wait_queue(&res->wq, &wait);
70 repeat:
71         set_current_state(TASK_UNINTERRUPTIBLE);
72         if (res->state & flags) {
73                 spin_unlock(&res->spinlock);
74                 schedule();
75                 spin_lock(&res->spinlock);
76                 goto repeat;
77         }
78         remove_wait_queue(&res->wq, &wait);
79         __set_current_state(TASK_RUNNING);
80 }
81
82 int __dlm_lockres_has_locks(struct dlm_lock_resource *res)
83 {
84         if (list_empty(&res->granted) &&
85             list_empty(&res->converting) &&
86             list_empty(&res->blocked))
87                 return 0;
88         return 1;
89 }
90
91 /* "unused": the lockres has no locks, is not on the dirty list,
92  * has no inflight locks (in the gap between mastery and acquiring
93  * the first lock), and has no bits in its refmap.
94  * truly ready to be freed. */
95 int __dlm_lockres_unused(struct dlm_lock_resource *res)
96 {
97         if (!__dlm_lockres_has_locks(res) &&
98             (list_empty(&res->dirty) && !(res->state & DLM_LOCK_RES_DIRTY))) {
99                 /* try not to scan the bitmap unless the first two
100                  * conditions are already true */
101                 int bit = find_next_bit(res->refmap, O2NM_MAX_NODES, 0);
102                 if (bit >= O2NM_MAX_NODES) {
103                         /* since the bit for dlm->node_num is not
104                          * set, inflight_locks better be zero */
105                         BUG_ON(res->inflight_locks != 0);
106                         return 1;
107                 }
108         }
109         return 0;
110 }
111
112
113 /* Call whenever you may have added or deleted something from one of
114  * the lockres queue's. This will figure out whether it belongs on the
115  * unused list or not and does the appropriate thing. */
116 void __dlm_lockres_calc_usage(struct dlm_ctxt *dlm,
117                               struct dlm_lock_resource *res)
118 {
119         mlog_entry("%.*s\n", res->lockname.len, res->lockname.name);
120
121         assert_spin_locked(&dlm->spinlock);
122         assert_spin_locked(&res->spinlock);
123
124         if (__dlm_lockres_unused(res)){
125                 if (list_empty(&res->purge)) {
126                         mlog(0, "putting lockres %.*s:%p onto purge list\n",
127                              res->lockname.len, res->lockname.name, res);
128
129                         res->last_used = jiffies;
130                         dlm_lockres_get(res);
131                         list_add_tail(&res->purge, &dlm->purge_list);
132                         dlm->purge_count++;
133                 }
134         } else if (!list_empty(&res->purge)) {
135                 mlog(0, "removing lockres %.*s:%p from purge list, owner=%u\n",
136                      res->lockname.len, res->lockname.name, res, res->owner);
137
138                 list_del_init(&res->purge);
139                 dlm_lockres_put(res);
140                 dlm->purge_count--;
141         }
142 }
143
144 void dlm_lockres_calc_usage(struct dlm_ctxt *dlm,
145                             struct dlm_lock_resource *res)
146 {
147         mlog_entry("%.*s\n", res->lockname.len, res->lockname.name);
148         spin_lock(&dlm->spinlock);
149         spin_lock(&res->spinlock);
150
151         __dlm_lockres_calc_usage(dlm, res);
152
153         spin_unlock(&res->spinlock);
154         spin_unlock(&dlm->spinlock);
155 }
156
157 static int dlm_purge_lockres(struct dlm_ctxt *dlm,
158                              struct dlm_lock_resource *res)
159 {
160         int master;
161         int ret = 0;
162
163         spin_lock(&res->spinlock);
164         if (!__dlm_lockres_unused(res)) {
165                 spin_unlock(&res->spinlock);
166                 mlog(0, "%s:%.*s: tried to purge but not unused\n",
167                      dlm->name, res->lockname.len, res->lockname.name);
168                 return -ENOTEMPTY;
169         }
170         master = (res->owner == dlm->node_num);
171         if (!master)
172                 res->state |= DLM_LOCK_RES_DROPPING_REF;
173         spin_unlock(&res->spinlock);
174
175         mlog(0, "purging lockres %.*s, master = %d\n", res->lockname.len,
176              res->lockname.name, master);
177
178         if (!master) {
179                 spin_lock(&res->spinlock);
180                 /* This ensures that clear refmap is sent after the set */
181                 __dlm_wait_on_lockres_flags(res, DLM_LOCK_RES_SETREF_INPROG);
182                 spin_unlock(&res->spinlock);
183                 /* drop spinlock to do messaging, retake below */
184                 spin_unlock(&dlm->spinlock);
185                 /* clear our bit from the master's refmap, ignore errors */
186                 ret = dlm_drop_lockres_ref(dlm, res);
187                 if (ret < 0) {
188                         mlog_errno(ret);
189                         if (!dlm_is_host_down(ret))
190                                 BUG();
191                 }
192                 mlog(0, "%s:%.*s: dlm_deref_lockres returned %d\n",
193                      dlm->name, res->lockname.len, res->lockname.name, ret);
194                 spin_lock(&dlm->spinlock);
195         }
196
197         if (!list_empty(&res->purge)) {
198                 mlog(0, "removing lockres %.*s:%p from purgelist, "
199                      "master = %d\n", res->lockname.len, res->lockname.name,
200                      res, master);
201                 list_del_init(&res->purge);
202                 dlm_lockres_put(res);
203                 dlm->purge_count--;
204         }
205         __dlm_unhash_lockres(res);
206
207         /* lockres is not in the hash now.  drop the flag and wake up
208          * any processes waiting in dlm_get_lock_resource. */
209         if (!master) {
210                 spin_lock(&res->spinlock);
211                 res->state &= ~DLM_LOCK_RES_DROPPING_REF;
212                 spin_unlock(&res->spinlock);
213                 wake_up(&res->wq);
214         }
215         return 0;
216 }
217
218 static void dlm_run_purge_list(struct dlm_ctxt *dlm,
219                                int purge_now)
220 {
221         unsigned int run_max, unused;
222         unsigned long purge_jiffies;
223         struct dlm_lock_resource *lockres;
224
225         spin_lock(&dlm->spinlock);
226         run_max = dlm->purge_count;
227
228         while(run_max && !list_empty(&dlm->purge_list)) {
229                 run_max--;
230
231                 lockres = list_entry(dlm->purge_list.next,
232                                      struct dlm_lock_resource, purge);
233
234                 /* Status of the lockres *might* change so double
235                  * check. If the lockres is unused, holding the dlm
236                  * spinlock will prevent people from getting and more
237                  * refs on it -- there's no need to keep the lockres
238                  * spinlock. */
239                 spin_lock(&lockres->spinlock);
240                 unused = __dlm_lockres_unused(lockres);
241                 spin_unlock(&lockres->spinlock);
242
243                 if (!unused)
244                         continue;
245
246                 purge_jiffies = lockres->last_used +
247                         msecs_to_jiffies(DLM_PURGE_INTERVAL_MS);
248
249                 /* Make sure that we want to be processing this guy at
250                  * this time. */
251                 if (!purge_now && time_after(purge_jiffies, jiffies)) {
252                         /* Since resources are added to the purge list
253                          * in tail order, we can stop at the first
254                          * unpurgable resource -- anyone added after
255                          * him will have a greater last_used value */
256                         break;
257                 }
258
259                 dlm_lockres_get(lockres);
260
261                 /* This may drop and reacquire the dlm spinlock if it
262                  * has to do migration. */
263                 if (dlm_purge_lockres(dlm, lockres))
264                         BUG();
265
266                 dlm_lockres_put(lockres);
267
268                 /* Avoid adding any scheduling latencies */
269                 cond_resched_lock(&dlm->spinlock);
270         }
271
272         spin_unlock(&dlm->spinlock);
273 }
274
275 static void dlm_shuffle_lists(struct dlm_ctxt *dlm,
276                               struct dlm_lock_resource *res)
277 {
278         struct dlm_lock *lock, *target;
279         struct list_head *iter;
280         struct list_head *head;
281         int can_grant = 1;
282
283         //mlog(0, "res->lockname.len=%d\n", res->lockname.len);
284         //mlog(0, "res->lockname.name=%p\n", res->lockname.name);
285         //mlog(0, "shuffle res %.*s\n", res->lockname.len,
286         //        res->lockname.name);
287
288         /* because this function is called with the lockres
289          * spinlock, and because we know that it is not migrating/
290          * recovering/in-progress, it is fine to reserve asts and
291          * basts right before queueing them all throughout */
292         assert_spin_locked(&res->spinlock);
293         BUG_ON((res->state & (DLM_LOCK_RES_MIGRATING|
294                               DLM_LOCK_RES_RECOVERING|
295                               DLM_LOCK_RES_IN_PROGRESS)));
296
297 converting:
298         if (list_empty(&res->converting))
299                 goto blocked;
300         mlog(0, "res %.*s has locks on a convert queue\n", res->lockname.len,
301              res->lockname.name);
302
303         target = list_entry(res->converting.next, struct dlm_lock, list);
304         if (target->ml.convert_type == LKM_IVMODE) {
305                 mlog(ML_ERROR, "%.*s: converting a lock with no "
306                      "convert_type!\n", res->lockname.len, res->lockname.name);
307                 BUG();
308         }
309         head = &res->granted;
310         list_for_each(iter, head) {
311                 lock = list_entry(iter, struct dlm_lock, list);
312                 if (lock==target)
313                         continue;
314                 if (!dlm_lock_compatible(lock->ml.type,
315                                          target->ml.convert_type)) {
316                         can_grant = 0;
317                         /* queue the BAST if not already */
318                         if (lock->ml.highest_blocked == LKM_IVMODE) {
319                                 __dlm_lockres_reserve_ast(res);
320                                 dlm_queue_bast(dlm, lock);
321                         }
322                         /* update the highest_blocked if needed */
323                         if (lock->ml.highest_blocked < target->ml.convert_type)
324                                 lock->ml.highest_blocked =
325                                         target->ml.convert_type;
326                 }
327         }
328         head = &res->converting;
329         list_for_each(iter, head) {
330                 lock = list_entry(iter, struct dlm_lock, list);
331                 if (lock==target)
332                         continue;
333                 if (!dlm_lock_compatible(lock->ml.type,
334                                          target->ml.convert_type)) {
335                         can_grant = 0;
336                         if (lock->ml.highest_blocked == LKM_IVMODE) {
337                                 __dlm_lockres_reserve_ast(res);
338                                 dlm_queue_bast(dlm, lock);
339                         }
340                         if (lock->ml.highest_blocked < target->ml.convert_type)
341                                 lock->ml.highest_blocked =
342                                         target->ml.convert_type;
343                 }
344         }
345
346         /* we can convert the lock */
347         if (can_grant) {
348                 spin_lock(&target->spinlock);
349                 BUG_ON(target->ml.highest_blocked != LKM_IVMODE);
350
351                 mlog(0, "calling ast for converting lock: %.*s, have: %d, "
352                      "granting: %d, node: %u\n", res->lockname.len,
353                      res->lockname.name, target->ml.type,
354                      target->ml.convert_type, target->ml.node);
355
356                 target->ml.type = target->ml.convert_type;
357                 target->ml.convert_type = LKM_IVMODE;
358                 list_move_tail(&target->list, &res->granted);
359
360                 BUG_ON(!target->lksb);
361                 target->lksb->status = DLM_NORMAL;
362
363                 spin_unlock(&target->spinlock);
364
365                 __dlm_lockres_reserve_ast(res);
366                 dlm_queue_ast(dlm, target);
367                 /* go back and check for more */
368                 goto converting;
369         }
370
371 blocked:
372         if (list_empty(&res->blocked))
373                 goto leave;
374         target = list_entry(res->blocked.next, struct dlm_lock, list);
375
376         head = &res->granted;
377         list_for_each(iter, head) {
378                 lock = list_entry(iter, struct dlm_lock, list);
379                 if (lock==target)
380                         continue;
381                 if (!dlm_lock_compatible(lock->ml.type, target->ml.type)) {
382                         can_grant = 0;
383                         if (lock->ml.highest_blocked == LKM_IVMODE) {
384                                 __dlm_lockres_reserve_ast(res);
385                                 dlm_queue_bast(dlm, lock);
386                         }
387                         if (lock->ml.highest_blocked < target->ml.type)
388                                 lock->ml.highest_blocked = target->ml.type;
389                 }
390         }
391
392         head = &res->converting;
393         list_for_each(iter, head) {
394                 lock = list_entry(iter, struct dlm_lock, list);
395                 if (lock==target)
396                         continue;
397                 if (!dlm_lock_compatible(lock->ml.type, target->ml.type)) {
398                         can_grant = 0;
399                         if (lock->ml.highest_blocked == LKM_IVMODE) {
400                                 __dlm_lockres_reserve_ast(res);
401                                 dlm_queue_bast(dlm, lock);
402                         }
403                         if (lock->ml.highest_blocked < target->ml.type)
404                                 lock->ml.highest_blocked = target->ml.type;
405                 }
406         }
407
408         /* we can grant the blocked lock (only
409          * possible if converting list empty) */
410         if (can_grant) {
411                 spin_lock(&target->spinlock);
412                 BUG_ON(target->ml.highest_blocked != LKM_IVMODE);
413
414                 mlog(0, "calling ast for blocked lock: %.*s, granting: %d, "
415                      "node: %u\n", res->lockname.len, res->lockname.name,
416                      target->ml.type, target->ml.node);
417
418                 // target->ml.type is already correct
419                 list_move_tail(&target->list, &res->granted);
420
421                 BUG_ON(!target->lksb);
422                 target->lksb->status = DLM_NORMAL;
423
424                 spin_unlock(&target->spinlock);
425
426                 __dlm_lockres_reserve_ast(res);
427                 dlm_queue_ast(dlm, target);
428                 /* go back and check for more */
429                 goto converting;
430         }
431
432 leave:
433         return;
434 }
435
436 /* must have NO locks when calling this with res !=NULL * */
437 void dlm_kick_thread(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
438 {
439         mlog_entry("dlm=%p, res=%p\n", dlm, res);
440         if (res) {
441                 spin_lock(&dlm->spinlock);
442                 spin_lock(&res->spinlock);
443                 __dlm_dirty_lockres(dlm, res);
444                 spin_unlock(&res->spinlock);
445                 spin_unlock(&dlm->spinlock);
446         }
447         wake_up(&dlm->dlm_thread_wq);
448 }
449
450 void __dlm_dirty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
451 {
452         mlog_entry("dlm=%p, res=%p\n", dlm, res);
453
454         assert_spin_locked(&dlm->spinlock);
455         assert_spin_locked(&res->spinlock);
456
457         /* don't shuffle secondary queues */
458         if ((res->owner == dlm->node_num)) {
459                 if (res->state & (DLM_LOCK_RES_MIGRATING |
460                                   DLM_LOCK_RES_BLOCK_DIRTY))
461                     return;
462
463                 if (list_empty(&res->dirty)) {
464                         /* ref for dirty_list */
465                         dlm_lockres_get(res);
466                         list_add_tail(&res->dirty, &dlm->dirty_list);
467                         res->state |= DLM_LOCK_RES_DIRTY;
468                 }
469         }
470 }
471
472
473 /* Launch the NM thread for the mounted volume */
474 int dlm_launch_thread(struct dlm_ctxt *dlm)
475 {
476         mlog(0, "starting dlm thread...\n");
477
478         dlm->dlm_thread_task = kthread_run(dlm_thread, dlm, "dlm_thread");
479         if (IS_ERR(dlm->dlm_thread_task)) {
480                 mlog_errno(PTR_ERR(dlm->dlm_thread_task));
481                 dlm->dlm_thread_task = NULL;
482                 return -EINVAL;
483         }
484
485         return 0;
486 }
487
488 void dlm_complete_thread(struct dlm_ctxt *dlm)
489 {
490         if (dlm->dlm_thread_task) {
491                 mlog(ML_KTHREAD, "waiting for dlm thread to exit\n");
492                 kthread_stop(dlm->dlm_thread_task);
493                 dlm->dlm_thread_task = NULL;
494         }
495 }
496
497 static int dlm_dirty_list_empty(struct dlm_ctxt *dlm)
498 {
499         int empty;
500
501         spin_lock(&dlm->spinlock);
502         empty = list_empty(&dlm->dirty_list);
503         spin_unlock(&dlm->spinlock);
504
505         return empty;
506 }
507
508 static void dlm_flush_asts(struct dlm_ctxt *dlm)
509 {
510         int ret;
511         struct dlm_lock *lock;
512         struct dlm_lock_resource *res;
513         u8 hi;
514
515         spin_lock(&dlm->ast_lock);
516         while (!list_empty(&dlm->pending_asts)) {
517                 lock = list_entry(dlm->pending_asts.next,
518                                   struct dlm_lock, ast_list);
519                 /* get an extra ref on lock */
520                 dlm_lock_get(lock);
521                 res = lock->lockres;
522                 mlog(0, "delivering an ast for this lockres\n");
523
524                 BUG_ON(!lock->ast_pending);
525
526                 /* remove from list (including ref) */
527                 list_del_init(&lock->ast_list);
528                 dlm_lock_put(lock);
529                 spin_unlock(&dlm->ast_lock);
530
531                 if (lock->ml.node != dlm->node_num) {
532                         ret = dlm_do_remote_ast(dlm, res, lock);
533                         if (ret < 0)
534                                 mlog_errno(ret);
535                 } else
536                         dlm_do_local_ast(dlm, res, lock);
537
538                 spin_lock(&dlm->ast_lock);
539
540                 /* possible that another ast was queued while
541                  * we were delivering the last one */
542                 if (!list_empty(&lock->ast_list)) {
543                         mlog(0, "aha another ast got queued while "
544                              "we were finishing the last one.  will "
545                              "keep the ast_pending flag set.\n");
546                 } else
547                         lock->ast_pending = 0;
548
549                 /* drop the extra ref.
550                  * this may drop it completely. */
551                 dlm_lock_put(lock);
552                 dlm_lockres_release_ast(dlm, res);
553         }
554
555         while (!list_empty(&dlm->pending_basts)) {
556                 lock = list_entry(dlm->pending_basts.next,
557                                   struct dlm_lock, bast_list);
558                 /* get an extra ref on lock */
559                 dlm_lock_get(lock);
560                 res = lock->lockres;
561
562                 BUG_ON(!lock->bast_pending);
563
564                 /* get the highest blocked lock, and reset */
565                 spin_lock(&lock->spinlock);
566                 BUG_ON(lock->ml.highest_blocked <= LKM_IVMODE);
567                 hi = lock->ml.highest_blocked;
568                 lock->ml.highest_blocked = LKM_IVMODE;
569                 spin_unlock(&lock->spinlock);
570
571                 /* remove from list (including ref) */
572                 list_del_init(&lock->bast_list);
573                 dlm_lock_put(lock);
574                 spin_unlock(&dlm->ast_lock);
575
576                 mlog(0, "delivering a bast for this lockres "
577                      "(blocked = %d\n", hi);
578
579                 if (lock->ml.node != dlm->node_num) {
580                         ret = dlm_send_proxy_bast(dlm, res, lock, hi);
581                         if (ret < 0)
582                                 mlog_errno(ret);
583                 } else
584                         dlm_do_local_bast(dlm, res, lock, hi);
585
586                 spin_lock(&dlm->ast_lock);
587
588                 /* possible that another bast was queued while
589                  * we were delivering the last one */
590                 if (!list_empty(&lock->bast_list)) {
591                         mlog(0, "aha another bast got queued while "
592                              "we were finishing the last one.  will "
593                              "keep the bast_pending flag set.\n");
594                 } else
595                         lock->bast_pending = 0;
596
597                 /* drop the extra ref.
598                  * this may drop it completely. */
599                 dlm_lock_put(lock);
600                 dlm_lockres_release_ast(dlm, res);
601         }
602         wake_up(&dlm->ast_wq);
603         spin_unlock(&dlm->ast_lock);
604 }
605
606
607 #define DLM_THREAD_TIMEOUT_MS (4 * 1000)
608 #define DLM_THREAD_MAX_DIRTY  100
609 #define DLM_THREAD_MAX_ASTS   10
610
611 static int dlm_thread(void *data)
612 {
613         struct dlm_lock_resource *res;
614         struct dlm_ctxt *dlm = data;
615         unsigned long timeout = msecs_to_jiffies(DLM_THREAD_TIMEOUT_MS);
616
617         mlog(0, "dlm thread running for %s...\n", dlm->name);
618
619         while (!kthread_should_stop()) {
620                 int n = DLM_THREAD_MAX_DIRTY;
621
622                 /* dlm_shutting_down is very point-in-time, but that
623                  * doesn't matter as we'll just loop back around if we
624                  * get false on the leading edge of a state
625                  * transition. */
626                 dlm_run_purge_list(dlm, dlm_shutting_down(dlm));
627
628                 /* We really don't want to hold dlm->spinlock while
629                  * calling dlm_shuffle_lists on each lockres that
630                  * needs to have its queues adjusted and AST/BASTs
631                  * run.  So let's pull each entry off the dirty_list
632                  * and drop dlm->spinlock ASAP.  Once off the list,
633                  * res->spinlock needs to be taken again to protect
634                  * the queues while calling dlm_shuffle_lists.  */
635                 spin_lock(&dlm->spinlock);
636                 while (!list_empty(&dlm->dirty_list)) {
637                         int delay = 0;
638                         res = list_entry(dlm->dirty_list.next,
639                                          struct dlm_lock_resource, dirty);
640
641                         /* peel a lockres off, remove it from the list,
642                          * unset the dirty flag and drop the dlm lock */
643                         BUG_ON(!res);
644                         dlm_lockres_get(res);
645
646                         spin_lock(&res->spinlock);
647                         /* We clear the DLM_LOCK_RES_DIRTY state once we shuffle lists below */
648                         list_del_init(&res->dirty);
649                         spin_unlock(&res->spinlock);
650                         spin_unlock(&dlm->spinlock);
651                         /* Drop dirty_list ref */
652                         dlm_lockres_put(res);
653
654                         /* lockres can be re-dirtied/re-added to the
655                          * dirty_list in this gap, but that is ok */
656
657                         spin_lock(&res->spinlock);
658                         if (res->owner != dlm->node_num) {
659                                 __dlm_print_one_lock_resource(res);
660                                 mlog(ML_ERROR, "inprog:%s, mig:%s, reco:%s, dirty:%s\n",
661                                      res->state & DLM_LOCK_RES_IN_PROGRESS ? "yes" : "no",
662                                      res->state & DLM_LOCK_RES_MIGRATING ? "yes" : "no",
663                                      res->state & DLM_LOCK_RES_RECOVERING ? "yes" : "no",
664                                      res->state & DLM_LOCK_RES_DIRTY ? "yes" : "no");
665                         }
666                         BUG_ON(res->owner != dlm->node_num);
667
668                         /* it is now ok to move lockreses in these states
669                          * to the dirty list, assuming that they will only be
670                          * dirty for a short while. */
671                         BUG_ON(res->state & DLM_LOCK_RES_MIGRATING);
672                         if (res->state & (DLM_LOCK_RES_IN_PROGRESS |
673                                           DLM_LOCK_RES_RECOVERING)) {
674                                 /* move it to the tail and keep going */
675                                 res->state &= ~DLM_LOCK_RES_DIRTY;
676                                 spin_unlock(&res->spinlock);
677                                 mlog(0, "delaying list shuffling for in-"
678                                      "progress lockres %.*s, state=%d\n",
679                                      res->lockname.len, res->lockname.name,
680                                      res->state);
681                                 delay = 1;
682                                 goto in_progress;
683                         }
684
685                         /* at this point the lockres is not migrating/
686                          * recovering/in-progress.  we have the lockres
687                          * spinlock and do NOT have the dlm lock.
688                          * safe to reserve/queue asts and run the lists. */
689
690                         mlog(0, "calling dlm_shuffle_lists with dlm=%s, "
691                              "res=%.*s\n", dlm->name,
692                              res->lockname.len, res->lockname.name);
693
694                         /* called while holding lockres lock */
695                         dlm_shuffle_lists(dlm, res);
696                         res->state &= ~DLM_LOCK_RES_DIRTY;
697                         spin_unlock(&res->spinlock);
698
699                         dlm_lockres_calc_usage(dlm, res);
700
701 in_progress:
702
703                         spin_lock(&dlm->spinlock);
704                         /* if the lock was in-progress, stick
705                          * it on the back of the list */
706                         if (delay) {
707                                 spin_lock(&res->spinlock);
708                                 __dlm_dirty_lockres(dlm, res);
709                                 spin_unlock(&res->spinlock);
710                         }
711                         dlm_lockres_put(res);
712
713                         /* unlikely, but we may need to give time to
714                          * other tasks */
715                         if (!--n) {
716                                 mlog(0, "throttling dlm_thread\n");
717                                 break;
718                         }
719                 }
720
721                 spin_unlock(&dlm->spinlock);
722                 dlm_flush_asts(dlm);
723
724                 /* yield and continue right away if there is more work to do */
725                 if (!n) {
726                         cond_resched();
727                         continue;
728                 }
729
730                 wait_event_interruptible_timeout(dlm->dlm_thread_wq,
731                                                  !dlm_dirty_list_empty(dlm) ||
732                                                  kthread_should_stop(),
733                                                  timeout);
734         }
735
736         mlog(0, "quitting DLM thread\n");
737         return 0;
738 }