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 */
__dlm_wait_on_lockres_flags(struct dlm_lock_resource * res,int flags)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
__dlm_lockres_has_locks(struct dlm_lock_resource * res)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. */
__dlm_lockres_unused(struct dlm_lock_resource * res)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. */
__dlm_lockres_calc_usage(struct dlm_ctxt * dlm,struct dlm_lock_resource * res)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
dlm_lockres_calc_usage(struct dlm_ctxt * dlm,struct dlm_lock_resource * res)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
dlm_purge_lockres(struct dlm_ctxt * dlm,struct dlm_lock_resource * res)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 /* drop spinlock... retake below */
180 spin_unlock(&dlm->spinlock);
181
182 spin_lock(&res->spinlock);
183 /* This ensures that clear refmap is sent after the set */
184 __dlm_wait_on_lockres_flags(res, DLM_LOCK_RES_SETREF_INPROG);
185 spin_unlock(&res->spinlock);
186
187 /* clear our bit from the master's refmap, ignore errors */
188 ret = dlm_drop_lockres_ref(dlm, res);
189 if (ret < 0) {
190 mlog_errno(ret);
191 if (!dlm_is_host_down(ret))
192 BUG();
193 }
194 mlog(0, "%s:%.*s: dlm_deref_lockres returned %d\n",
195 dlm->name, res->lockname.len, res->lockname.name, ret);
196 spin_lock(&dlm->spinlock);
197 }
198
199 if (!list_empty(&res->purge)) {
200 mlog(0, "removing lockres %.*s:%p from purgelist, "
201 "master = %d\n", res->lockname.len, res->lockname.name,
202 res, master);
203 list_del_init(&res->purge);
204 dlm_lockres_put(res);
205 dlm->purge_count--;
206 }
207 __dlm_unhash_lockres(res);
208
209 /* lockres is not in the hash now. drop the flag and wake up
210 * any processes waiting in dlm_get_lock_resource. */
211 if (!master) {
212 spin_lock(&res->spinlock);
213 res->state &= ~DLM_LOCK_RES_DROPPING_REF;
214 spin_unlock(&res->spinlock);
215 wake_up(&res->wq);
216 }
217 return 0;
218 }
219
dlm_run_purge_list(struct dlm_ctxt * dlm,int purge_now)220 static void dlm_run_purge_list(struct dlm_ctxt *dlm,
221 int purge_now)
222 {
223 unsigned int run_max, unused;
224 unsigned long purge_jiffies;
225 struct dlm_lock_resource *lockres;
226
227 spin_lock(&dlm->spinlock);
228 run_max = dlm->purge_count;
229
230 while(run_max && !list_empty(&dlm->purge_list)) {
231 run_max--;
232
233 lockres = list_entry(dlm->purge_list.next,
234 struct dlm_lock_resource, purge);
235
236 /* Status of the lockres *might* change so double
237 * check. If the lockres is unused, holding the dlm
238 * spinlock will prevent people from getting and more
239 * refs on it -- there's no need to keep the lockres
240 * spinlock. */
241 spin_lock(&lockres->spinlock);
242 unused = __dlm_lockres_unused(lockres);
243 spin_unlock(&lockres->spinlock);
244
245 if (!unused)
246 continue;
247
248 purge_jiffies = lockres->last_used +
249 msecs_to_jiffies(DLM_PURGE_INTERVAL_MS);
250
251 /* Make sure that we want to be processing this guy at
252 * this time. */
253 if (!purge_now && time_after(purge_jiffies, jiffies)) {
254 /* Since resources are added to the purge list
255 * in tail order, we can stop at the first
256 * unpurgable resource -- anyone added after
257 * him will have a greater last_used value */
258 break;
259 }
260
261 dlm_lockres_get(lockres);
262
263 /* This may drop and reacquire the dlm spinlock if it
264 * has to do migration. */
265 if (dlm_purge_lockres(dlm, lockres))
266 BUG();
267
268 dlm_lockres_put(lockres);
269
270 /* Avoid adding any scheduling latencies */
271 cond_resched_lock(&dlm->spinlock);
272 }
273
274 spin_unlock(&dlm->spinlock);
275 }
276
dlm_shuffle_lists(struct dlm_ctxt * dlm,struct dlm_lock_resource * res)277 static void dlm_shuffle_lists(struct dlm_ctxt *dlm,
278 struct dlm_lock_resource *res)
279 {
280 struct dlm_lock *lock, *target;
281 struct list_head *iter;
282 struct list_head *head;
283 int can_grant = 1;
284
285 //mlog(0, "res->lockname.len=%d\n", res->lockname.len);
286 //mlog(0, "res->lockname.name=%p\n", res->lockname.name);
287 //mlog(0, "shuffle res %.*s\n", res->lockname.len,
288 // res->lockname.name);
289
290 /* because this function is called with the lockres
291 * spinlock, and because we know that it is not migrating/
292 * recovering/in-progress, it is fine to reserve asts and
293 * basts right before queueing them all throughout */
294 assert_spin_locked(&res->spinlock);
295 BUG_ON((res->state & (DLM_LOCK_RES_MIGRATING|
296 DLM_LOCK_RES_RECOVERING|
297 DLM_LOCK_RES_IN_PROGRESS)));
298
299 converting:
300 if (list_empty(&res->converting))
301 goto blocked;
302 mlog(0, "res %.*s has locks on a convert queue\n", res->lockname.len,
303 res->lockname.name);
304
305 target = list_entry(res->converting.next, struct dlm_lock, list);
306 if (target->ml.convert_type == LKM_IVMODE) {
307 mlog(ML_ERROR, "%.*s: converting a lock with no "
308 "convert_type!\n", res->lockname.len, res->lockname.name);
309 BUG();
310 }
311 head = &res->granted;
312 list_for_each(iter, head) {
313 lock = list_entry(iter, struct dlm_lock, list);
314 if (lock==target)
315 continue;
316 if (!dlm_lock_compatible(lock->ml.type,
317 target->ml.convert_type)) {
318 can_grant = 0;
319 /* queue the BAST if not already */
320 if (lock->ml.highest_blocked == LKM_IVMODE) {
321 __dlm_lockres_reserve_ast(res);
322 dlm_queue_bast(dlm, lock);
323 }
324 /* update the highest_blocked if needed */
325 if (lock->ml.highest_blocked < target->ml.convert_type)
326 lock->ml.highest_blocked =
327 target->ml.convert_type;
328 }
329 }
330 head = &res->converting;
331 list_for_each(iter, head) {
332 lock = list_entry(iter, struct dlm_lock, list);
333 if (lock==target)
334 continue;
335 if (!dlm_lock_compatible(lock->ml.type,
336 target->ml.convert_type)) {
337 can_grant = 0;
338 if (lock->ml.highest_blocked == LKM_IVMODE) {
339 __dlm_lockres_reserve_ast(res);
340 dlm_queue_bast(dlm, lock);
341 }
342 if (lock->ml.highest_blocked < target->ml.convert_type)
343 lock->ml.highest_blocked =
344 target->ml.convert_type;
345 }
346 }
347
348 /* we can convert the lock */
349 if (can_grant) {
350 spin_lock(&target->spinlock);
351 BUG_ON(target->ml.highest_blocked != LKM_IVMODE);
352
353 mlog(0, "calling ast for converting lock: %.*s, have: %d, "
354 "granting: %d, node: %u\n", res->lockname.len,
355 res->lockname.name, target->ml.type,
356 target->ml.convert_type, target->ml.node);
357
358 target->ml.type = target->ml.convert_type;
359 target->ml.convert_type = LKM_IVMODE;
360 list_move_tail(&target->list, &res->granted);
361
362 BUG_ON(!target->lksb);
363 target->lksb->status = DLM_NORMAL;
364
365 spin_unlock(&target->spinlock);
366
367 __dlm_lockres_reserve_ast(res);
368 dlm_queue_ast(dlm, target);
369 /* go back and check for more */
370 goto converting;
371 }
372
373 blocked:
374 if (list_empty(&res->blocked))
375 goto leave;
376 target = list_entry(res->blocked.next, struct dlm_lock, list);
377
378 head = &res->granted;
379 list_for_each(iter, head) {
380 lock = list_entry(iter, struct dlm_lock, list);
381 if (lock==target)
382 continue;
383 if (!dlm_lock_compatible(lock->ml.type, target->ml.type)) {
384 can_grant = 0;
385 if (lock->ml.highest_blocked == LKM_IVMODE) {
386 __dlm_lockres_reserve_ast(res);
387 dlm_queue_bast(dlm, lock);
388 }
389 if (lock->ml.highest_blocked < target->ml.type)
390 lock->ml.highest_blocked = target->ml.type;
391 }
392 }
393
394 head = &res->converting;
395 list_for_each(iter, head) {
396 lock = list_entry(iter, struct dlm_lock, list);
397 if (lock==target)
398 continue;
399 if (!dlm_lock_compatible(lock->ml.type, target->ml.type)) {
400 can_grant = 0;
401 if (lock->ml.highest_blocked == LKM_IVMODE) {
402 __dlm_lockres_reserve_ast(res);
403 dlm_queue_bast(dlm, lock);
404 }
405 if (lock->ml.highest_blocked < target->ml.type)
406 lock->ml.highest_blocked = target->ml.type;
407 }
408 }
409
410 /* we can grant the blocked lock (only
411 * possible if converting list empty) */
412 if (can_grant) {
413 spin_lock(&target->spinlock);
414 BUG_ON(target->ml.highest_blocked != LKM_IVMODE);
415
416 mlog(0, "calling ast for blocked lock: %.*s, granting: %d, "
417 "node: %u\n", res->lockname.len, res->lockname.name,
418 target->ml.type, target->ml.node);
419
420 // target->ml.type is already correct
421 list_move_tail(&target->list, &res->granted);
422
423 BUG_ON(!target->lksb);
424 target->lksb->status = DLM_NORMAL;
425
426 spin_unlock(&target->spinlock);
427
428 __dlm_lockres_reserve_ast(res);
429 dlm_queue_ast(dlm, target);
430 /* go back and check for more */
431 goto converting;
432 }
433
434 leave:
435 return;
436 }
437
438 /* must have NO locks when calling this with res !=NULL * */
dlm_kick_thread(struct dlm_ctxt * dlm,struct dlm_lock_resource * res)439 void dlm_kick_thread(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
440 {
441 mlog_entry("dlm=%p, res=%p\n", dlm, res);
442 if (res) {
443 spin_lock(&dlm->spinlock);
444 spin_lock(&res->spinlock);
445 __dlm_dirty_lockres(dlm, res);
446 spin_unlock(&res->spinlock);
447 spin_unlock(&dlm->spinlock);
448 }
449 wake_up(&dlm->dlm_thread_wq);
450 }
451
__dlm_dirty_lockres(struct dlm_ctxt * dlm,struct dlm_lock_resource * res)452 void __dlm_dirty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
453 {
454 mlog_entry("dlm=%p, res=%p\n", dlm, res);
455
456 assert_spin_locked(&dlm->spinlock);
457 assert_spin_locked(&res->spinlock);
458
459 /* don't shuffle secondary queues */
460 if ((res->owner == dlm->node_num)) {
461 if (res->state & (DLM_LOCK_RES_MIGRATING |
462 DLM_LOCK_RES_BLOCK_DIRTY))
463 return;
464
465 if (list_empty(&res->dirty)) {
466 /* ref for dirty_list */
467 dlm_lockres_get(res);
468 list_add_tail(&res->dirty, &dlm->dirty_list);
469 res->state |= DLM_LOCK_RES_DIRTY;
470 }
471 }
472 }
473
474
475 /* Launch the NM thread for the mounted volume */
dlm_launch_thread(struct dlm_ctxt * dlm)476 int dlm_launch_thread(struct dlm_ctxt *dlm)
477 {
478 mlog(0, "starting dlm thread...\n");
479
480 dlm->dlm_thread_task = kthread_run(dlm_thread, dlm, "dlm_thread");
481 if (IS_ERR(dlm->dlm_thread_task)) {
482 mlog_errno(PTR_ERR(dlm->dlm_thread_task));
483 dlm->dlm_thread_task = NULL;
484 return -EINVAL;
485 }
486
487 return 0;
488 }
489
dlm_complete_thread(struct dlm_ctxt * dlm)490 void dlm_complete_thread(struct dlm_ctxt *dlm)
491 {
492 if (dlm->dlm_thread_task) {
493 mlog(ML_KTHREAD, "waiting for dlm thread to exit\n");
494 kthread_stop(dlm->dlm_thread_task);
495 dlm->dlm_thread_task = NULL;
496 }
497 }
498
dlm_dirty_list_empty(struct dlm_ctxt * dlm)499 static int dlm_dirty_list_empty(struct dlm_ctxt *dlm)
500 {
501 int empty;
502
503 spin_lock(&dlm->spinlock);
504 empty = list_empty(&dlm->dirty_list);
505 spin_unlock(&dlm->spinlock);
506
507 return empty;
508 }
509
dlm_flush_asts(struct dlm_ctxt * dlm)510 static void dlm_flush_asts(struct dlm_ctxt *dlm)
511 {
512 int ret;
513 struct dlm_lock *lock;
514 struct dlm_lock_resource *res;
515 u8 hi;
516
517 spin_lock(&dlm->ast_lock);
518 while (!list_empty(&dlm->pending_asts)) {
519 lock = list_entry(dlm->pending_asts.next,
520 struct dlm_lock, ast_list);
521 /* get an extra ref on lock */
522 dlm_lock_get(lock);
523 res = lock->lockres;
524 mlog(0, "delivering an ast for this lockres\n");
525
526 BUG_ON(!lock->ast_pending);
527
528 /* remove from list (including ref) */
529 list_del_init(&lock->ast_list);
530 dlm_lock_put(lock);
531 spin_unlock(&dlm->ast_lock);
532
533 if (lock->ml.node != dlm->node_num) {
534 ret = dlm_do_remote_ast(dlm, res, lock);
535 if (ret < 0)
536 mlog_errno(ret);
537 } else
538 dlm_do_local_ast(dlm, res, lock);
539
540 spin_lock(&dlm->ast_lock);
541
542 /* possible that another ast was queued while
543 * we were delivering the last one */
544 if (!list_empty(&lock->ast_list)) {
545 mlog(0, "aha another ast got queued while "
546 "we were finishing the last one. will "
547 "keep the ast_pending flag set.\n");
548 } else
549 lock->ast_pending = 0;
550
551 /* drop the extra ref.
552 * this may drop it completely. */
553 dlm_lock_put(lock);
554 dlm_lockres_release_ast(dlm, res);
555 }
556
557 while (!list_empty(&dlm->pending_basts)) {
558 lock = list_entry(dlm->pending_basts.next,
559 struct dlm_lock, bast_list);
560 /* get an extra ref on lock */
561 dlm_lock_get(lock);
562 res = lock->lockres;
563
564 BUG_ON(!lock->bast_pending);
565
566 /* get the highest blocked lock, and reset */
567 spin_lock(&lock->spinlock);
568 BUG_ON(lock->ml.highest_blocked <= LKM_IVMODE);
569 hi = lock->ml.highest_blocked;
570 lock->ml.highest_blocked = LKM_IVMODE;
571 spin_unlock(&lock->spinlock);
572
573 /* remove from list (including ref) */
574 list_del_init(&lock->bast_list);
575 dlm_lock_put(lock);
576 spin_unlock(&dlm->ast_lock);
577
578 mlog(0, "delivering a bast for this lockres "
579 "(blocked = %d\n", hi);
580
581 if (lock->ml.node != dlm->node_num) {
582 ret = dlm_send_proxy_bast(dlm, res, lock, hi);
583 if (ret < 0)
584 mlog_errno(ret);
585 } else
586 dlm_do_local_bast(dlm, res, lock, hi);
587
588 spin_lock(&dlm->ast_lock);
589
590 /* possible that another bast was queued while
591 * we were delivering the last one */
592 if (!list_empty(&lock->bast_list)) {
593 mlog(0, "aha another bast got queued while "
594 "we were finishing the last one. will "
595 "keep the bast_pending flag set.\n");
596 } else
597 lock->bast_pending = 0;
598
599 /* drop the extra ref.
600 * this may drop it completely. */
601 dlm_lock_put(lock);
602 dlm_lockres_release_ast(dlm, res);
603 }
604 wake_up(&dlm->ast_wq);
605 spin_unlock(&dlm->ast_lock);
606 }
607
608
609 #define DLM_THREAD_TIMEOUT_MS (4 * 1000)
610 #define DLM_THREAD_MAX_DIRTY 100
611 #define DLM_THREAD_MAX_ASTS 10
612
dlm_thread(void * data)613 static int dlm_thread(void *data)
614 {
615 struct dlm_lock_resource *res;
616 struct dlm_ctxt *dlm = data;
617 unsigned long timeout = msecs_to_jiffies(DLM_THREAD_TIMEOUT_MS);
618
619 mlog(0, "dlm thread running for %s...\n", dlm->name);
620
621 while (!kthread_should_stop()) {
622 int n = DLM_THREAD_MAX_DIRTY;
623
624 /* dlm_shutting_down is very point-in-time, but that
625 * doesn't matter as we'll just loop back around if we
626 * get false on the leading edge of a state
627 * transition. */
628 dlm_run_purge_list(dlm, dlm_shutting_down(dlm));
629
630 /* We really don't want to hold dlm->spinlock while
631 * calling dlm_shuffle_lists on each lockres that
632 * needs to have its queues adjusted and AST/BASTs
633 * run. So let's pull each entry off the dirty_list
634 * and drop dlm->spinlock ASAP. Once off the list,
635 * res->spinlock needs to be taken again to protect
636 * the queues while calling dlm_shuffle_lists. */
637 spin_lock(&dlm->spinlock);
638 while (!list_empty(&dlm->dirty_list)) {
639 int delay = 0;
640 res = list_entry(dlm->dirty_list.next,
641 struct dlm_lock_resource, dirty);
642
643 /* peel a lockres off, remove it from the list,
644 * unset the dirty flag and drop the dlm lock */
645 BUG_ON(!res);
646 dlm_lockres_get(res);
647
648 spin_lock(&res->spinlock);
649 /* We clear the DLM_LOCK_RES_DIRTY state once we shuffle lists below */
650 list_del_init(&res->dirty);
651 spin_unlock(&res->spinlock);
652 spin_unlock(&dlm->spinlock);
653 /* Drop dirty_list ref */
654 dlm_lockres_put(res);
655
656 /* lockres can be re-dirtied/re-added to the
657 * dirty_list in this gap, but that is ok */
658
659 spin_lock(&res->spinlock);
660 if (res->owner != dlm->node_num) {
661 __dlm_print_one_lock_resource(res);
662 mlog(ML_ERROR, "inprog:%s, mig:%s, reco:%s, dirty:%s\n",
663 res->state & DLM_LOCK_RES_IN_PROGRESS ? "yes" : "no",
664 res->state & DLM_LOCK_RES_MIGRATING ? "yes" : "no",
665 res->state & DLM_LOCK_RES_RECOVERING ? "yes" : "no",
666 res->state & DLM_LOCK_RES_DIRTY ? "yes" : "no");
667 }
668 BUG_ON(res->owner != dlm->node_num);
669
670 /* it is now ok to move lockreses in these states
671 * to the dirty list, assuming that they will only be
672 * dirty for a short while. */
673 BUG_ON(res->state & DLM_LOCK_RES_MIGRATING);
674 if (res->state & (DLM_LOCK_RES_IN_PROGRESS |
675 DLM_LOCK_RES_RECOVERING)) {
676 /* move it to the tail and keep going */
677 res->state &= ~DLM_LOCK_RES_DIRTY;
678 spin_unlock(&res->spinlock);
679 mlog(0, "delaying list shuffling for in-"
680 "progress lockres %.*s, state=%d\n",
681 res->lockname.len, res->lockname.name,
682 res->state);
683 delay = 1;
684 goto in_progress;
685 }
686
687 /* at this point the lockres is not migrating/
688 * recovering/in-progress. we have the lockres
689 * spinlock and do NOT have the dlm lock.
690 * safe to reserve/queue asts and run the lists. */
691
692 mlog(0, "calling dlm_shuffle_lists with dlm=%s, "
693 "res=%.*s\n", dlm->name,
694 res->lockname.len, res->lockname.name);
695
696 /* called while holding lockres lock */
697 dlm_shuffle_lists(dlm, res);
698 res->state &= ~DLM_LOCK_RES_DIRTY;
699 spin_unlock(&res->spinlock);
700
701 dlm_lockres_calc_usage(dlm, res);
702
703 in_progress:
704
705 spin_lock(&dlm->spinlock);
706 /* if the lock was in-progress, stick
707 * it on the back of the list */
708 if (delay) {
709 spin_lock(&res->spinlock);
710 __dlm_dirty_lockres(dlm, res);
711 spin_unlock(&res->spinlock);
712 }
713 dlm_lockres_put(res);
714
715 /* unlikely, but we may need to give time to
716 * other tasks */
717 if (!--n) {
718 mlog(0, "throttling dlm_thread\n");
719 break;
720 }
721 }
722
723 spin_unlock(&dlm->spinlock);
724 dlm_flush_asts(dlm);
725
726 /* yield and continue right away if there is more work to do */
727 if (!n) {
728 cond_resched();
729 continue;
730 }
731
732 wait_event_interruptible_timeout(dlm->dlm_thread_wq,
733 !dlm_dirty_list_empty(dlm) ||
734 kthread_should_stop(),
735 timeout);
736 }
737
738 mlog(0, "quitting DLM thread\n");
739 return 0;
740 }
741