Commit | Line | Data |
---|---|---|
6714d8e8 KH |
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 | ||
43 | ||
44 | #include "cluster/heartbeat.h" | |
45 | #include "cluster/nodemanager.h" | |
46 | #include "cluster/tcp.h" | |
47 | ||
48 | #include "dlmapi.h" | |
49 | #include "dlmcommon.h" | |
50 | #include "dlmdomain.h" | |
51 | ||
52 | #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_THREAD) | |
53 | #include "cluster/masklog.h" | |
54 | ||
6714d8e8 KH |
55 | static int dlm_thread(void *data); |
56 | ||
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 | current->state = TASK_RUNNING; | |
80 | } | |
81 | ||
82 | ||
83 | static int __dlm_lockres_unused(struct dlm_lock_resource *res) | |
84 | { | |
85 | if (list_empty(&res->granted) && | |
86 | list_empty(&res->converting) && | |
87 | list_empty(&res->blocked) && | |
88 | list_empty(&res->dirty)) | |
89 | return 1; | |
90 | return 0; | |
91 | } | |
92 | ||
93 | ||
94 | /* Call whenever you may have added or deleted something from one of | |
95 | * the lockres queue's. This will figure out whether it belongs on the | |
96 | * unused list or not and does the appropriate thing. */ | |
97 | void __dlm_lockres_calc_usage(struct dlm_ctxt *dlm, | |
98 | struct dlm_lock_resource *res) | |
99 | { | |
100 | mlog_entry("%.*s\n", res->lockname.len, res->lockname.name); | |
101 | ||
102 | assert_spin_locked(&dlm->spinlock); | |
103 | assert_spin_locked(&res->spinlock); | |
104 | ||
105 | if (__dlm_lockres_unused(res)){ | |
106 | if (list_empty(&res->purge)) { | |
107 | mlog(0, "putting lockres %.*s from purge list\n", | |
108 | res->lockname.len, res->lockname.name); | |
109 | ||
110 | res->last_used = jiffies; | |
111 | list_add_tail(&res->purge, &dlm->purge_list); | |
112 | dlm->purge_count++; | |
113 | } | |
114 | } else if (!list_empty(&res->purge)) { | |
115 | mlog(0, "removing lockres %.*s from purge list\n", | |
116 | res->lockname.len, res->lockname.name); | |
117 | ||
118 | list_del_init(&res->purge); | |
119 | dlm->purge_count--; | |
120 | } | |
121 | } | |
122 | ||
123 | void dlm_lockres_calc_usage(struct dlm_ctxt *dlm, | |
124 | struct dlm_lock_resource *res) | |
125 | { | |
126 | mlog_entry("%.*s\n", res->lockname.len, res->lockname.name); | |
127 | spin_lock(&dlm->spinlock); | |
128 | spin_lock(&res->spinlock); | |
129 | ||
130 | __dlm_lockres_calc_usage(dlm, res); | |
131 | ||
132 | spin_unlock(&res->spinlock); | |
133 | spin_unlock(&dlm->spinlock); | |
134 | } | |
135 | ||
136 | /* TODO: Eventual API: Called with the dlm spinlock held, may drop it | |
137 | * to do migration, but will re-acquire before exit. */ | |
138 | void dlm_purge_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *lockres) | |
139 | { | |
140 | int master; | |
141 | int ret; | |
142 | ||
143 | spin_lock(&lockres->spinlock); | |
144 | master = lockres->owner == dlm->node_num; | |
145 | spin_unlock(&lockres->spinlock); | |
146 | ||
147 | mlog(0, "purging lockres %.*s, master = %d\n", lockres->lockname.len, | |
148 | lockres->lockname.name, master); | |
149 | ||
150 | /* Non master is the easy case -- no migration required, just | |
151 | * quit. */ | |
152 | if (!master) | |
153 | goto finish; | |
154 | ||
155 | /* Wheee! Migrate lockres here! */ | |
156 | spin_unlock(&dlm->spinlock); | |
157 | again: | |
158 | ||
159 | ret = dlm_migrate_lockres(dlm, lockres, O2NM_MAX_NODES); | |
160 | if (ret == -ENOTEMPTY) { | |
161 | mlog(ML_ERROR, "lockres %.*s still has local locks!\n", | |
162 | lockres->lockname.len, lockres->lockname.name); | |
163 | ||
164 | BUG(); | |
165 | } else if (ret < 0) { | |
166 | mlog(ML_NOTICE, "lockres %.*s: migrate failed, retrying\n", | |
167 | lockres->lockname.len, lockres->lockname.name); | |
168 | goto again; | |
169 | } | |
170 | ||
171 | spin_lock(&dlm->spinlock); | |
172 | ||
173 | finish: | |
174 | if (!list_empty(&lockres->purge)) { | |
175 | list_del_init(&lockres->purge); | |
176 | dlm->purge_count--; | |
177 | } | |
178 | __dlm_unhash_lockres(lockres); | |
179 | } | |
180 | ||
181 | static void dlm_run_purge_list(struct dlm_ctxt *dlm, | |
182 | int purge_now) | |
183 | { | |
184 | unsigned int run_max, unused; | |
185 | unsigned long purge_jiffies; | |
186 | struct dlm_lock_resource *lockres; | |
187 | ||
188 | spin_lock(&dlm->spinlock); | |
189 | run_max = dlm->purge_count; | |
190 | ||
191 | while(run_max && !list_empty(&dlm->purge_list)) { | |
192 | run_max--; | |
193 | ||
194 | lockres = list_entry(dlm->purge_list.next, | |
195 | struct dlm_lock_resource, purge); | |
196 | ||
197 | /* Status of the lockres *might* change so double | |
198 | * check. If the lockres is unused, holding the dlm | |
199 | * spinlock will prevent people from getting and more | |
200 | * refs on it -- there's no need to keep the lockres | |
201 | * spinlock. */ | |
202 | spin_lock(&lockres->spinlock); | |
203 | unused = __dlm_lockres_unused(lockres); | |
204 | spin_unlock(&lockres->spinlock); | |
205 | ||
206 | if (!unused) | |
207 | continue; | |
208 | ||
209 | purge_jiffies = lockres->last_used + | |
210 | msecs_to_jiffies(DLM_PURGE_INTERVAL_MS); | |
211 | ||
212 | /* Make sure that we want to be processing this guy at | |
213 | * this time. */ | |
214 | if (!purge_now && time_after(purge_jiffies, jiffies)) { | |
215 | /* Since resources are added to the purge list | |
216 | * in tail order, we can stop at the first | |
217 | * unpurgable resource -- anyone added after | |
218 | * him will have a greater last_used value */ | |
219 | break; | |
220 | } | |
221 | ||
222 | list_del_init(&lockres->purge); | |
223 | dlm->purge_count--; | |
224 | ||
225 | /* This may drop and reacquire the dlm spinlock if it | |
226 | * has to do migration. */ | |
227 | mlog(0, "calling dlm_purge_lockres!\n"); | |
228 | dlm_purge_lockres(dlm, lockres); | |
229 | mlog(0, "DONE calling dlm_purge_lockres!\n"); | |
230 | ||
231 | /* Avoid adding any scheduling latencies */ | |
232 | cond_resched_lock(&dlm->spinlock); | |
233 | } | |
234 | ||
235 | spin_unlock(&dlm->spinlock); | |
236 | } | |
237 | ||
238 | static void dlm_shuffle_lists(struct dlm_ctxt *dlm, | |
239 | struct dlm_lock_resource *res) | |
240 | { | |
241 | struct dlm_lock *lock, *target; | |
242 | struct list_head *iter; | |
243 | struct list_head *head; | |
244 | int can_grant = 1; | |
245 | ||
246 | //mlog(0, "res->lockname.len=%d\n", res->lockname.len); | |
247 | //mlog(0, "res->lockname.name=%p\n", res->lockname.name); | |
248 | //mlog(0, "shuffle res %.*s\n", res->lockname.len, | |
249 | // res->lockname.name); | |
250 | ||
251 | /* because this function is called with the lockres | |
252 | * spinlock, and because we know that it is not migrating/ | |
253 | * recovering/in-progress, it is fine to reserve asts and | |
254 | * basts right before queueing them all throughout */ | |
255 | assert_spin_locked(&res->spinlock); | |
256 | BUG_ON((res->state & (DLM_LOCK_RES_MIGRATING| | |
257 | DLM_LOCK_RES_RECOVERING| | |
258 | DLM_LOCK_RES_IN_PROGRESS))); | |
259 | ||
260 | converting: | |
261 | if (list_empty(&res->converting)) | |
262 | goto blocked; | |
263 | mlog(0, "res %.*s has locks on a convert queue\n", res->lockname.len, | |
264 | res->lockname.name); | |
265 | ||
266 | target = list_entry(res->converting.next, struct dlm_lock, list); | |
267 | if (target->ml.convert_type == LKM_IVMODE) { | |
268 | mlog(ML_ERROR, "%.*s: converting a lock with no " | |
269 | "convert_type!\n", res->lockname.len, res->lockname.name); | |
270 | BUG(); | |
271 | } | |
272 | head = &res->granted; | |
273 | list_for_each(iter, head) { | |
274 | lock = list_entry(iter, struct dlm_lock, list); | |
275 | if (lock==target) | |
276 | continue; | |
277 | if (!dlm_lock_compatible(lock->ml.type, | |
278 | target->ml.convert_type)) { | |
279 | can_grant = 0; | |
280 | /* queue the BAST if not already */ | |
281 | if (lock->ml.highest_blocked == LKM_IVMODE) { | |
282 | __dlm_lockres_reserve_ast(res); | |
283 | dlm_queue_bast(dlm, lock); | |
284 | } | |
285 | /* update the highest_blocked if needed */ | |
286 | if (lock->ml.highest_blocked < target->ml.convert_type) | |
287 | lock->ml.highest_blocked = | |
288 | target->ml.convert_type; | |
289 | } | |
290 | } | |
291 | head = &res->converting; | |
292 | list_for_each(iter, head) { | |
293 | lock = list_entry(iter, struct dlm_lock, list); | |
294 | if (lock==target) | |
295 | continue; | |
296 | if (!dlm_lock_compatible(lock->ml.type, | |
297 | target->ml.convert_type)) { | |
298 | can_grant = 0; | |
299 | if (lock->ml.highest_blocked == LKM_IVMODE) { | |
300 | __dlm_lockres_reserve_ast(res); | |
301 | dlm_queue_bast(dlm, lock); | |
302 | } | |
303 | if (lock->ml.highest_blocked < target->ml.convert_type) | |
304 | lock->ml.highest_blocked = | |
305 | target->ml.convert_type; | |
306 | } | |
307 | } | |
308 | ||
309 | /* we can convert the lock */ | |
310 | if (can_grant) { | |
311 | spin_lock(&target->spinlock); | |
312 | BUG_ON(target->ml.highest_blocked != LKM_IVMODE); | |
313 | ||
314 | mlog(0, "calling ast for converting lock: %.*s, have: %d, " | |
315 | "granting: %d, node: %u\n", res->lockname.len, | |
316 | res->lockname.name, target->ml.type, | |
317 | target->ml.convert_type, target->ml.node); | |
318 | ||
319 | target->ml.type = target->ml.convert_type; | |
320 | target->ml.convert_type = LKM_IVMODE; | |
f116629d | 321 | list_move_tail(&target->list, &res->granted); |
6714d8e8 KH |
322 | |
323 | BUG_ON(!target->lksb); | |
324 | target->lksb->status = DLM_NORMAL; | |
325 | ||
326 | spin_unlock(&target->spinlock); | |
327 | ||
328 | __dlm_lockres_reserve_ast(res); | |
329 | dlm_queue_ast(dlm, target); | |
330 | /* go back and check for more */ | |
331 | goto converting; | |
332 | } | |
333 | ||
334 | blocked: | |
335 | if (list_empty(&res->blocked)) | |
336 | goto leave; | |
337 | target = list_entry(res->blocked.next, struct dlm_lock, list); | |
338 | ||
339 | head = &res->granted; | |
340 | list_for_each(iter, head) { | |
341 | lock = list_entry(iter, struct dlm_lock, list); | |
342 | if (lock==target) | |
343 | continue; | |
344 | if (!dlm_lock_compatible(lock->ml.type, target->ml.type)) { | |
345 | can_grant = 0; | |
346 | if (lock->ml.highest_blocked == LKM_IVMODE) { | |
347 | __dlm_lockres_reserve_ast(res); | |
348 | dlm_queue_bast(dlm, lock); | |
349 | } | |
350 | if (lock->ml.highest_blocked < target->ml.type) | |
351 | lock->ml.highest_blocked = target->ml.type; | |
352 | } | |
353 | } | |
354 | ||
355 | head = &res->converting; | |
356 | list_for_each(iter, head) { | |
357 | lock = list_entry(iter, struct dlm_lock, list); | |
358 | if (lock==target) | |
359 | continue; | |
360 | if (!dlm_lock_compatible(lock->ml.type, target->ml.type)) { | |
361 | can_grant = 0; | |
362 | if (lock->ml.highest_blocked == LKM_IVMODE) { | |
363 | __dlm_lockres_reserve_ast(res); | |
364 | dlm_queue_bast(dlm, lock); | |
365 | } | |
366 | if (lock->ml.highest_blocked < target->ml.type) | |
367 | lock->ml.highest_blocked = target->ml.type; | |
368 | } | |
369 | } | |
370 | ||
371 | /* we can grant the blocked lock (only | |
372 | * possible if converting list empty) */ | |
373 | if (can_grant) { | |
374 | spin_lock(&target->spinlock); | |
375 | BUG_ON(target->ml.highest_blocked != LKM_IVMODE); | |
376 | ||
377 | mlog(0, "calling ast for blocked lock: %.*s, granting: %d, " | |
378 | "node: %u\n", res->lockname.len, res->lockname.name, | |
379 | target->ml.type, target->ml.node); | |
380 | ||
381 | // target->ml.type is already correct | |
f116629d | 382 | list_move_tail(&target->list, &res->granted); |
6714d8e8 KH |
383 | |
384 | BUG_ON(!target->lksb); | |
385 | target->lksb->status = DLM_NORMAL; | |
386 | ||
387 | spin_unlock(&target->spinlock); | |
388 | ||
389 | __dlm_lockres_reserve_ast(res); | |
390 | dlm_queue_ast(dlm, target); | |
391 | /* go back and check for more */ | |
392 | goto converting; | |
393 | } | |
394 | ||
395 | leave: | |
396 | return; | |
397 | } | |
398 | ||
399 | /* must have NO locks when calling this with res !=NULL * */ | |
400 | void dlm_kick_thread(struct dlm_ctxt *dlm, struct dlm_lock_resource *res) | |
401 | { | |
402 | mlog_entry("dlm=%p, res=%p\n", dlm, res); | |
403 | if (res) { | |
404 | spin_lock(&dlm->spinlock); | |
405 | spin_lock(&res->spinlock); | |
406 | __dlm_dirty_lockres(dlm, res); | |
407 | spin_unlock(&res->spinlock); | |
408 | spin_unlock(&dlm->spinlock); | |
409 | } | |
410 | wake_up(&dlm->dlm_thread_wq); | |
411 | } | |
412 | ||
413 | void __dlm_dirty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res) | |
414 | { | |
415 | mlog_entry("dlm=%p, res=%p\n", dlm, res); | |
416 | ||
417 | assert_spin_locked(&dlm->spinlock); | |
418 | assert_spin_locked(&res->spinlock); | |
419 | ||
420 | /* don't shuffle secondary queues */ | |
421 | if ((res->owner == dlm->node_num) && | |
422 | !(res->state & DLM_LOCK_RES_DIRTY)) { | |
423 | list_add_tail(&res->dirty, &dlm->dirty_list); | |
424 | res->state |= DLM_LOCK_RES_DIRTY; | |
425 | } | |
426 | } | |
427 | ||
428 | ||
429 | /* Launch the NM thread for the mounted volume */ | |
430 | int dlm_launch_thread(struct dlm_ctxt *dlm) | |
431 | { | |
432 | mlog(0, "starting dlm thread...\n"); | |
433 | ||
434 | dlm->dlm_thread_task = kthread_run(dlm_thread, dlm, "dlm_thread"); | |
435 | if (IS_ERR(dlm->dlm_thread_task)) { | |
436 | mlog_errno(PTR_ERR(dlm->dlm_thread_task)); | |
437 | dlm->dlm_thread_task = NULL; | |
438 | return -EINVAL; | |
439 | } | |
440 | ||
441 | return 0; | |
442 | } | |
443 | ||
444 | void dlm_complete_thread(struct dlm_ctxt *dlm) | |
445 | { | |
446 | if (dlm->dlm_thread_task) { | |
447 | mlog(ML_KTHREAD, "waiting for dlm thread to exit\n"); | |
448 | kthread_stop(dlm->dlm_thread_task); | |
449 | dlm->dlm_thread_task = NULL; | |
450 | } | |
451 | } | |
452 | ||
453 | static int dlm_dirty_list_empty(struct dlm_ctxt *dlm) | |
454 | { | |
455 | int empty; | |
456 | ||
457 | spin_lock(&dlm->spinlock); | |
458 | empty = list_empty(&dlm->dirty_list); | |
459 | spin_unlock(&dlm->spinlock); | |
460 | ||
461 | return empty; | |
462 | } | |
463 | ||
464 | static void dlm_flush_asts(struct dlm_ctxt *dlm) | |
465 | { | |
466 | int ret; | |
467 | struct dlm_lock *lock; | |
468 | struct dlm_lock_resource *res; | |
469 | u8 hi; | |
470 | ||
471 | spin_lock(&dlm->ast_lock); | |
472 | while (!list_empty(&dlm->pending_asts)) { | |
473 | lock = list_entry(dlm->pending_asts.next, | |
474 | struct dlm_lock, ast_list); | |
475 | /* get an extra ref on lock */ | |
476 | dlm_lock_get(lock); | |
477 | res = lock->lockres; | |
478 | mlog(0, "delivering an ast for this lockres\n"); | |
479 | ||
480 | BUG_ON(!lock->ast_pending); | |
481 | ||
482 | /* remove from list (including ref) */ | |
483 | list_del_init(&lock->ast_list); | |
484 | dlm_lock_put(lock); | |
485 | spin_unlock(&dlm->ast_lock); | |
486 | ||
487 | if (lock->ml.node != dlm->node_num) { | |
488 | ret = dlm_do_remote_ast(dlm, res, lock); | |
489 | if (ret < 0) | |
490 | mlog_errno(ret); | |
491 | } else | |
492 | dlm_do_local_ast(dlm, res, lock); | |
493 | ||
494 | spin_lock(&dlm->ast_lock); | |
495 | ||
496 | /* possible that another ast was queued while | |
497 | * we were delivering the last one */ | |
498 | if (!list_empty(&lock->ast_list)) { | |
499 | mlog(0, "aha another ast got queued while " | |
500 | "we were finishing the last one. will " | |
501 | "keep the ast_pending flag set.\n"); | |
502 | } else | |
503 | lock->ast_pending = 0; | |
504 | ||
505 | /* drop the extra ref. | |
506 | * this may drop it completely. */ | |
507 | dlm_lock_put(lock); | |
508 | dlm_lockres_release_ast(dlm, res); | |
509 | } | |
510 | ||
511 | while (!list_empty(&dlm->pending_basts)) { | |
512 | lock = list_entry(dlm->pending_basts.next, | |
513 | struct dlm_lock, bast_list); | |
514 | /* get an extra ref on lock */ | |
515 | dlm_lock_get(lock); | |
516 | res = lock->lockres; | |
517 | ||
518 | BUG_ON(!lock->bast_pending); | |
519 | ||
520 | /* get the highest blocked lock, and reset */ | |
521 | spin_lock(&lock->spinlock); | |
522 | BUG_ON(lock->ml.highest_blocked <= LKM_IVMODE); | |
523 | hi = lock->ml.highest_blocked; | |
524 | lock->ml.highest_blocked = LKM_IVMODE; | |
525 | spin_unlock(&lock->spinlock); | |
526 | ||
527 | /* remove from list (including ref) */ | |
528 | list_del_init(&lock->bast_list); | |
529 | dlm_lock_put(lock); | |
530 | spin_unlock(&dlm->ast_lock); | |
531 | ||
532 | mlog(0, "delivering a bast for this lockres " | |
533 | "(blocked = %d\n", hi); | |
534 | ||
535 | if (lock->ml.node != dlm->node_num) { | |
536 | ret = dlm_send_proxy_bast(dlm, res, lock, hi); | |
537 | if (ret < 0) | |
538 | mlog_errno(ret); | |
539 | } else | |
540 | dlm_do_local_bast(dlm, res, lock, hi); | |
541 | ||
542 | spin_lock(&dlm->ast_lock); | |
543 | ||
544 | /* possible that another bast was queued while | |
545 | * we were delivering the last one */ | |
546 | if (!list_empty(&lock->bast_list)) { | |
547 | mlog(0, "aha another bast got queued while " | |
548 | "we were finishing the last one. will " | |
549 | "keep the bast_pending flag set.\n"); | |
550 | } else | |
551 | lock->bast_pending = 0; | |
552 | ||
553 | /* drop the extra ref. | |
554 | * this may drop it completely. */ | |
555 | dlm_lock_put(lock); | |
556 | dlm_lockres_release_ast(dlm, res); | |
557 | } | |
558 | wake_up(&dlm->ast_wq); | |
559 | spin_unlock(&dlm->ast_lock); | |
560 | } | |
561 | ||
562 | ||
563 | #define DLM_THREAD_TIMEOUT_MS (4 * 1000) | |
564 | #define DLM_THREAD_MAX_DIRTY 100 | |
565 | #define DLM_THREAD_MAX_ASTS 10 | |
566 | ||
567 | static int dlm_thread(void *data) | |
568 | { | |
569 | struct dlm_lock_resource *res; | |
570 | struct dlm_ctxt *dlm = data; | |
571 | unsigned long timeout = msecs_to_jiffies(DLM_THREAD_TIMEOUT_MS); | |
572 | ||
573 | mlog(0, "dlm thread running for %s...\n", dlm->name); | |
574 | ||
575 | while (!kthread_should_stop()) { | |
576 | int n = DLM_THREAD_MAX_DIRTY; | |
577 | ||
578 | /* dlm_shutting_down is very point-in-time, but that | |
579 | * doesn't matter as we'll just loop back around if we | |
580 | * get false on the leading edge of a state | |
581 | * transition. */ | |
582 | dlm_run_purge_list(dlm, dlm_shutting_down(dlm)); | |
583 | ||
584 | /* We really don't want to hold dlm->spinlock while | |
585 | * calling dlm_shuffle_lists on each lockres that | |
586 | * needs to have its queues adjusted and AST/BASTs | |
587 | * run. So let's pull each entry off the dirty_list | |
588 | * and drop dlm->spinlock ASAP. Once off the list, | |
589 | * res->spinlock needs to be taken again to protect | |
590 | * the queues while calling dlm_shuffle_lists. */ | |
591 | spin_lock(&dlm->spinlock); | |
592 | while (!list_empty(&dlm->dirty_list)) { | |
593 | int delay = 0; | |
594 | res = list_entry(dlm->dirty_list.next, | |
595 | struct dlm_lock_resource, dirty); | |
596 | ||
597 | /* peel a lockres off, remove it from the list, | |
598 | * unset the dirty flag and drop the dlm lock */ | |
599 | BUG_ON(!res); | |
600 | dlm_lockres_get(res); | |
601 | ||
602 | spin_lock(&res->spinlock); | |
603 | res->state &= ~DLM_LOCK_RES_DIRTY; | |
604 | list_del_init(&res->dirty); | |
605 | spin_unlock(&res->spinlock); | |
606 | spin_unlock(&dlm->spinlock); | |
607 | ||
608 | /* lockres can be re-dirtied/re-added to the | |
609 | * dirty_list in this gap, but that is ok */ | |
610 | ||
611 | spin_lock(&res->spinlock); | |
612 | if (res->owner != dlm->node_num) { | |
613 | __dlm_print_one_lock_resource(res); | |
614 | mlog(ML_ERROR, "inprog:%s, mig:%s, reco:%s, dirty:%s\n", | |
615 | res->state & DLM_LOCK_RES_IN_PROGRESS ? "yes" : "no", | |
616 | res->state & DLM_LOCK_RES_MIGRATING ? "yes" : "no", | |
617 | res->state & DLM_LOCK_RES_RECOVERING ? "yes" : "no", | |
618 | res->state & DLM_LOCK_RES_DIRTY ? "yes" : "no"); | |
619 | } | |
620 | BUG_ON(res->owner != dlm->node_num); | |
621 | ||
622 | /* it is now ok to move lockreses in these states | |
623 | * to the dirty list, assuming that they will only be | |
624 | * dirty for a short while. */ | |
625 | if (res->state & (DLM_LOCK_RES_IN_PROGRESS | | |
626 | DLM_LOCK_RES_MIGRATING | | |
627 | DLM_LOCK_RES_RECOVERING)) { | |
628 | /* move it to the tail and keep going */ | |
629 | spin_unlock(&res->spinlock); | |
630 | mlog(0, "delaying list shuffling for in-" | |
631 | "progress lockres %.*s, state=%d\n", | |
632 | res->lockname.len, res->lockname.name, | |
633 | res->state); | |
634 | delay = 1; | |
635 | goto in_progress; | |
636 | } | |
637 | ||
638 | /* at this point the lockres is not migrating/ | |
639 | * recovering/in-progress. we have the lockres | |
640 | * spinlock and do NOT have the dlm lock. | |
641 | * safe to reserve/queue asts and run the lists. */ | |
642 | ||
643 | mlog(0, "calling dlm_shuffle_lists with dlm=%p, " | |
644 | "res=%p\n", dlm, res); | |
645 | ||
646 | /* called while holding lockres lock */ | |
647 | dlm_shuffle_lists(dlm, res); | |
648 | spin_unlock(&res->spinlock); | |
649 | ||
650 | dlm_lockres_calc_usage(dlm, res); | |
651 | ||
652 | in_progress: | |
653 | ||
654 | spin_lock(&dlm->spinlock); | |
655 | /* if the lock was in-progress, stick | |
656 | * it on the back of the list */ | |
657 | if (delay) { | |
658 | spin_lock(&res->spinlock); | |
659 | list_add_tail(&res->dirty, &dlm->dirty_list); | |
660 | res->state |= DLM_LOCK_RES_DIRTY; | |
661 | spin_unlock(&res->spinlock); | |
662 | } | |
663 | dlm_lockres_put(res); | |
664 | ||
665 | /* unlikely, but we may need to give time to | |
666 | * other tasks */ | |
667 | if (!--n) { | |
668 | mlog(0, "throttling dlm_thread\n"); | |
669 | break; | |
670 | } | |
671 | } | |
672 | ||
673 | spin_unlock(&dlm->spinlock); | |
674 | dlm_flush_asts(dlm); | |
675 | ||
676 | /* yield and continue right away if there is more work to do */ | |
677 | if (!n) { | |
678 | yield(); | |
679 | continue; | |
680 | } | |
681 | ||
682 | wait_event_interruptible_timeout(dlm->dlm_thread_wq, | |
683 | !dlm_dirty_list_empty(dlm) || | |
684 | kthread_should_stop(), | |
685 | timeout); | |
686 | } | |
687 | ||
688 | mlog(0, "quitting DLM thread\n"); | |
689 | return 0; | |
690 | } |