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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> | |
8d79d088 | 42 | #include <linux/delay.h> |
6714d8e8 KH |
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 | ||
6714d8e8 | 56 | static int dlm_thread(void *data); |
8b219809 KH |
57 | static void dlm_purge_lockres_now(struct dlm_ctxt *dlm, |
58 | struct dlm_lock_resource *lockres); | |
6714d8e8 KH |
59 | |
60 | static void dlm_flush_asts(struct dlm_ctxt *dlm); | |
61 | ||
62 | #define dlm_lock_is_remote(dlm, lock) ((lock)->ml.node != (dlm)->node_num) | |
63 | ||
64 | /* will exit holding res->spinlock, but may drop in function */ | |
65 | /* waits until flags are cleared on res->state */ | |
66 | void __dlm_wait_on_lockres_flags(struct dlm_lock_resource *res, int flags) | |
67 | { | |
68 | DECLARE_WAITQUEUE(wait, current); | |
69 | ||
70 | assert_spin_locked(&res->spinlock); | |
71 | ||
72 | add_wait_queue(&res->wq, &wait); | |
73 | repeat: | |
74 | set_current_state(TASK_UNINTERRUPTIBLE); | |
75 | if (res->state & flags) { | |
76 | spin_unlock(&res->spinlock); | |
77 | schedule(); | |
78 | spin_lock(&res->spinlock); | |
79 | goto repeat; | |
80 | } | |
81 | remove_wait_queue(&res->wq, &wait); | |
82 | current->state = TASK_RUNNING; | |
83 | } | |
84 | ||
85 | ||
69d72b06 | 86 | int __dlm_lockres_unused(struct dlm_lock_resource *res) |
6714d8e8 KH |
87 | { |
88 | if (list_empty(&res->granted) && | |
89 | list_empty(&res->converting) && | |
90 | list_empty(&res->blocked) && | |
91 | list_empty(&res->dirty)) | |
92 | return 1; | |
93 | return 0; | |
94 | } | |
95 | ||
96 | ||
97 | /* Call whenever you may have added or deleted something from one of | |
98 | * the lockres queue's. This will figure out whether it belongs on the | |
99 | * unused list or not and does the appropriate thing. */ | |
100 | void __dlm_lockres_calc_usage(struct dlm_ctxt *dlm, | |
101 | struct dlm_lock_resource *res) | |
102 | { | |
103 | mlog_entry("%.*s\n", res->lockname.len, res->lockname.name); | |
104 | ||
105 | assert_spin_locked(&dlm->spinlock); | |
106 | assert_spin_locked(&res->spinlock); | |
107 | ||
108 | if (__dlm_lockres_unused(res)){ | |
c87a9ae7 KH |
109 | /* For now, just keep any resource we master */ |
110 | if (res->owner == dlm->node_num) | |
111 | { | |
112 | if (!list_empty(&res->purge)) { | |
113 | mlog(0, "we master %s:%.*s, but it is on " | |
114 | "the purge list. Removing\n", | |
115 | dlm->name, res->lockname.len, | |
116 | res->lockname.name); | |
117 | list_del_init(&res->purge); | |
118 | dlm->purge_count--; | |
119 | } | |
120 | return; | |
121 | } | |
122 | ||
6714d8e8 KH |
123 | if (list_empty(&res->purge)) { |
124 | mlog(0, "putting lockres %.*s from purge list\n", | |
125 | res->lockname.len, res->lockname.name); | |
126 | ||
127 | res->last_used = jiffies; | |
128 | list_add_tail(&res->purge, &dlm->purge_list); | |
129 | dlm->purge_count++; | |
8b219809 KH |
130 | |
131 | /* if this node is not the owner, there is | |
132 | * no way to keep track of who the owner could be. | |
133 | * unhash it to avoid serious problems. */ | |
134 | if (res->owner != dlm->node_num) { | |
135 | mlog(0, "%s:%.*s: doing immediate " | |
136 | "purge of lockres owned by %u\n", | |
137 | dlm->name, res->lockname.len, | |
138 | res->lockname.name, res->owner); | |
139 | ||
140 | dlm_purge_lockres_now(dlm, res); | |
141 | } | |
6714d8e8 KH |
142 | } |
143 | } else if (!list_empty(&res->purge)) { | |
8b219809 KH |
144 | mlog(0, "removing lockres %.*s from purge list, " |
145 | "owner=%u\n", res->lockname.len, res->lockname.name, | |
146 | res->owner); | |
6714d8e8 KH |
147 | |
148 | list_del_init(&res->purge); | |
149 | dlm->purge_count--; | |
150 | } | |
151 | } | |
152 | ||
153 | void dlm_lockres_calc_usage(struct dlm_ctxt *dlm, | |
154 | struct dlm_lock_resource *res) | |
155 | { | |
156 | mlog_entry("%.*s\n", res->lockname.len, res->lockname.name); | |
157 | spin_lock(&dlm->spinlock); | |
158 | spin_lock(&res->spinlock); | |
159 | ||
160 | __dlm_lockres_calc_usage(dlm, res); | |
161 | ||
162 | spin_unlock(&res->spinlock); | |
163 | spin_unlock(&dlm->spinlock); | |
164 | } | |
165 | ||
166 | /* TODO: Eventual API: Called with the dlm spinlock held, may drop it | |
167 | * to do migration, but will re-acquire before exit. */ | |
168 | void dlm_purge_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *lockres) | |
169 | { | |
170 | int master; | |
171 | int ret; | |
172 | ||
173 | spin_lock(&lockres->spinlock); | |
174 | master = lockres->owner == dlm->node_num; | |
175 | spin_unlock(&lockres->spinlock); | |
176 | ||
177 | mlog(0, "purging lockres %.*s, master = %d\n", lockres->lockname.len, | |
178 | lockres->lockname.name, master); | |
179 | ||
180 | /* Non master is the easy case -- no migration required, just | |
181 | * quit. */ | |
182 | if (!master) | |
183 | goto finish; | |
184 | ||
185 | /* Wheee! Migrate lockres here! */ | |
186 | spin_unlock(&dlm->spinlock); | |
187 | again: | |
188 | ||
189 | ret = dlm_migrate_lockres(dlm, lockres, O2NM_MAX_NODES); | |
190 | if (ret == -ENOTEMPTY) { | |
191 | mlog(ML_ERROR, "lockres %.*s still has local locks!\n", | |
192 | lockres->lockname.len, lockres->lockname.name); | |
193 | ||
194 | BUG(); | |
195 | } else if (ret < 0) { | |
196 | mlog(ML_NOTICE, "lockres %.*s: migrate failed, retrying\n", | |
197 | lockres->lockname.len, lockres->lockname.name); | |
8d79d088 | 198 | msleep(100); |
6714d8e8 KH |
199 | goto again; |
200 | } | |
201 | ||
202 | spin_lock(&dlm->spinlock); | |
203 | ||
204 | finish: | |
205 | if (!list_empty(&lockres->purge)) { | |
206 | list_del_init(&lockres->purge); | |
207 | dlm->purge_count--; | |
208 | } | |
209 | __dlm_unhash_lockres(lockres); | |
210 | } | |
211 | ||
8b219809 KH |
212 | /* make an unused lockres go away immediately. |
213 | * as soon as the dlm spinlock is dropped, this lockres | |
214 | * will not be found. kfree still happens on last put. */ | |
215 | static void dlm_purge_lockres_now(struct dlm_ctxt *dlm, | |
216 | struct dlm_lock_resource *lockres) | |
217 | { | |
218 | assert_spin_locked(&dlm->spinlock); | |
219 | assert_spin_locked(&lockres->spinlock); | |
220 | ||
221 | BUG_ON(!__dlm_lockres_unused(lockres)); | |
222 | ||
223 | if (!list_empty(&lockres->purge)) { | |
224 | list_del_init(&lockres->purge); | |
225 | dlm->purge_count--; | |
226 | } | |
227 | __dlm_unhash_lockres(lockres); | |
228 | } | |
229 | ||
6714d8e8 KH |
230 | static void dlm_run_purge_list(struct dlm_ctxt *dlm, |
231 | int purge_now) | |
232 | { | |
233 | unsigned int run_max, unused; | |
234 | unsigned long purge_jiffies; | |
235 | struct dlm_lock_resource *lockres; | |
236 | ||
237 | spin_lock(&dlm->spinlock); | |
238 | run_max = dlm->purge_count; | |
239 | ||
240 | while(run_max && !list_empty(&dlm->purge_list)) { | |
241 | run_max--; | |
242 | ||
243 | lockres = list_entry(dlm->purge_list.next, | |
244 | struct dlm_lock_resource, purge); | |
245 | ||
246 | /* Status of the lockres *might* change so double | |
247 | * check. If the lockres is unused, holding the dlm | |
248 | * spinlock will prevent people from getting and more | |
249 | * refs on it -- there's no need to keep the lockres | |
250 | * spinlock. */ | |
251 | spin_lock(&lockres->spinlock); | |
252 | unused = __dlm_lockres_unused(lockres); | |
253 | spin_unlock(&lockres->spinlock); | |
254 | ||
255 | if (!unused) | |
256 | continue; | |
257 | ||
258 | purge_jiffies = lockres->last_used + | |
259 | msecs_to_jiffies(DLM_PURGE_INTERVAL_MS); | |
260 | ||
261 | /* Make sure that we want to be processing this guy at | |
262 | * this time. */ | |
263 | if (!purge_now && time_after(purge_jiffies, jiffies)) { | |
264 | /* Since resources are added to the purge list | |
265 | * in tail order, we can stop at the first | |
266 | * unpurgable resource -- anyone added after | |
267 | * him will have a greater last_used value */ | |
268 | break; | |
269 | } | |
270 | ||
271 | list_del_init(&lockres->purge); | |
272 | dlm->purge_count--; | |
273 | ||
274 | /* This may drop and reacquire the dlm spinlock if it | |
275 | * has to do migration. */ | |
276 | mlog(0, "calling dlm_purge_lockres!\n"); | |
277 | dlm_purge_lockres(dlm, lockres); | |
278 | mlog(0, "DONE calling dlm_purge_lockres!\n"); | |
279 | ||
280 | /* Avoid adding any scheduling latencies */ | |
281 | cond_resched_lock(&dlm->spinlock); | |
282 | } | |
283 | ||
284 | spin_unlock(&dlm->spinlock); | |
285 | } | |
286 | ||
287 | static void dlm_shuffle_lists(struct dlm_ctxt *dlm, | |
288 | struct dlm_lock_resource *res) | |
289 | { | |
290 | struct dlm_lock *lock, *target; | |
291 | struct list_head *iter; | |
292 | struct list_head *head; | |
293 | int can_grant = 1; | |
294 | ||
295 | //mlog(0, "res->lockname.len=%d\n", res->lockname.len); | |
296 | //mlog(0, "res->lockname.name=%p\n", res->lockname.name); | |
297 | //mlog(0, "shuffle res %.*s\n", res->lockname.len, | |
298 | // res->lockname.name); | |
299 | ||
300 | /* because this function is called with the lockres | |
301 | * spinlock, and because we know that it is not migrating/ | |
302 | * recovering/in-progress, it is fine to reserve asts and | |
303 | * basts right before queueing them all throughout */ | |
304 | assert_spin_locked(&res->spinlock); | |
305 | BUG_ON((res->state & (DLM_LOCK_RES_MIGRATING| | |
306 | DLM_LOCK_RES_RECOVERING| | |
307 | DLM_LOCK_RES_IN_PROGRESS))); | |
308 | ||
309 | converting: | |
310 | if (list_empty(&res->converting)) | |
311 | goto blocked; | |
312 | mlog(0, "res %.*s has locks on a convert queue\n", res->lockname.len, | |
313 | res->lockname.name); | |
314 | ||
315 | target = list_entry(res->converting.next, struct dlm_lock, list); | |
316 | if (target->ml.convert_type == LKM_IVMODE) { | |
317 | mlog(ML_ERROR, "%.*s: converting a lock with no " | |
318 | "convert_type!\n", res->lockname.len, res->lockname.name); | |
319 | BUG(); | |
320 | } | |
321 | head = &res->granted; | |
322 | list_for_each(iter, head) { | |
323 | lock = list_entry(iter, struct dlm_lock, list); | |
324 | if (lock==target) | |
325 | continue; | |
326 | if (!dlm_lock_compatible(lock->ml.type, | |
327 | target->ml.convert_type)) { | |
328 | can_grant = 0; | |
329 | /* queue the BAST if not already */ | |
330 | if (lock->ml.highest_blocked == LKM_IVMODE) { | |
331 | __dlm_lockres_reserve_ast(res); | |
332 | dlm_queue_bast(dlm, lock); | |
333 | } | |
334 | /* update the highest_blocked if needed */ | |
335 | if (lock->ml.highest_blocked < target->ml.convert_type) | |
336 | lock->ml.highest_blocked = | |
337 | target->ml.convert_type; | |
338 | } | |
339 | } | |
340 | head = &res->converting; | |
341 | list_for_each(iter, head) { | |
342 | lock = list_entry(iter, struct dlm_lock, list); | |
343 | if (lock==target) | |
344 | continue; | |
345 | if (!dlm_lock_compatible(lock->ml.type, | |
346 | target->ml.convert_type)) { | |
347 | can_grant = 0; | |
348 | if (lock->ml.highest_blocked == LKM_IVMODE) { | |
349 | __dlm_lockres_reserve_ast(res); | |
350 | dlm_queue_bast(dlm, lock); | |
351 | } | |
352 | if (lock->ml.highest_blocked < target->ml.convert_type) | |
353 | lock->ml.highest_blocked = | |
354 | target->ml.convert_type; | |
355 | } | |
356 | } | |
357 | ||
358 | /* we can convert the lock */ | |
359 | if (can_grant) { | |
360 | spin_lock(&target->spinlock); | |
361 | BUG_ON(target->ml.highest_blocked != LKM_IVMODE); | |
362 | ||
363 | mlog(0, "calling ast for converting lock: %.*s, have: %d, " | |
364 | "granting: %d, node: %u\n", res->lockname.len, | |
365 | res->lockname.name, target->ml.type, | |
366 | target->ml.convert_type, target->ml.node); | |
367 | ||
368 | target->ml.type = target->ml.convert_type; | |
369 | target->ml.convert_type = LKM_IVMODE; | |
f116629d | 370 | list_move_tail(&target->list, &res->granted); |
6714d8e8 KH |
371 | |
372 | BUG_ON(!target->lksb); | |
373 | target->lksb->status = DLM_NORMAL; | |
374 | ||
375 | spin_unlock(&target->spinlock); | |
376 | ||
377 | __dlm_lockres_reserve_ast(res); | |
378 | dlm_queue_ast(dlm, target); | |
379 | /* go back and check for more */ | |
380 | goto converting; | |
381 | } | |
382 | ||
383 | blocked: | |
384 | if (list_empty(&res->blocked)) | |
385 | goto leave; | |
386 | target = list_entry(res->blocked.next, struct dlm_lock, list); | |
387 | ||
388 | head = &res->granted; | |
389 | list_for_each(iter, head) { | |
390 | lock = list_entry(iter, struct dlm_lock, list); | |
391 | if (lock==target) | |
392 | continue; | |
393 | if (!dlm_lock_compatible(lock->ml.type, target->ml.type)) { | |
394 | can_grant = 0; | |
395 | if (lock->ml.highest_blocked == LKM_IVMODE) { | |
396 | __dlm_lockres_reserve_ast(res); | |
397 | dlm_queue_bast(dlm, lock); | |
398 | } | |
399 | if (lock->ml.highest_blocked < target->ml.type) | |
400 | lock->ml.highest_blocked = target->ml.type; | |
401 | } | |
402 | } | |
403 | ||
404 | head = &res->converting; | |
405 | list_for_each(iter, head) { | |
406 | lock = list_entry(iter, struct dlm_lock, list); | |
407 | if (lock==target) | |
408 | continue; | |
409 | if (!dlm_lock_compatible(lock->ml.type, target->ml.type)) { | |
410 | can_grant = 0; | |
411 | if (lock->ml.highest_blocked == LKM_IVMODE) { | |
412 | __dlm_lockres_reserve_ast(res); | |
413 | dlm_queue_bast(dlm, lock); | |
414 | } | |
415 | if (lock->ml.highest_blocked < target->ml.type) | |
416 | lock->ml.highest_blocked = target->ml.type; | |
417 | } | |
418 | } | |
419 | ||
420 | /* we can grant the blocked lock (only | |
421 | * possible if converting list empty) */ | |
422 | if (can_grant) { | |
423 | spin_lock(&target->spinlock); | |
424 | BUG_ON(target->ml.highest_blocked != LKM_IVMODE); | |
425 | ||
426 | mlog(0, "calling ast for blocked lock: %.*s, granting: %d, " | |
427 | "node: %u\n", res->lockname.len, res->lockname.name, | |
428 | target->ml.type, target->ml.node); | |
429 | ||
430 | // target->ml.type is already correct | |
f116629d | 431 | list_move_tail(&target->list, &res->granted); |
6714d8e8 KH |
432 | |
433 | BUG_ON(!target->lksb); | |
434 | target->lksb->status = DLM_NORMAL; | |
435 | ||
436 | spin_unlock(&target->spinlock); | |
437 | ||
438 | __dlm_lockres_reserve_ast(res); | |
439 | dlm_queue_ast(dlm, target); | |
440 | /* go back and check for more */ | |
441 | goto converting; | |
442 | } | |
443 | ||
444 | leave: | |
445 | return; | |
446 | } | |
447 | ||
448 | /* must have NO locks when calling this with res !=NULL * */ | |
449 | void dlm_kick_thread(struct dlm_ctxt *dlm, struct dlm_lock_resource *res) | |
450 | { | |
451 | mlog_entry("dlm=%p, res=%p\n", dlm, res); | |
452 | if (res) { | |
453 | spin_lock(&dlm->spinlock); | |
454 | spin_lock(&res->spinlock); | |
455 | __dlm_dirty_lockres(dlm, res); | |
456 | spin_unlock(&res->spinlock); | |
457 | spin_unlock(&dlm->spinlock); | |
458 | } | |
459 | wake_up(&dlm->dlm_thread_wq); | |
460 | } | |
461 | ||
462 | void __dlm_dirty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res) | |
463 | { | |
464 | mlog_entry("dlm=%p, res=%p\n", dlm, res); | |
465 | ||
466 | assert_spin_locked(&dlm->spinlock); | |
467 | assert_spin_locked(&res->spinlock); | |
468 | ||
469 | /* don't shuffle secondary queues */ | |
470 | if ((res->owner == dlm->node_num) && | |
471 | !(res->state & DLM_LOCK_RES_DIRTY)) { | |
6ff06a93 KH |
472 | /* ref for dirty_list */ |
473 | dlm_lockres_get(res); | |
6714d8e8 KH |
474 | list_add_tail(&res->dirty, &dlm->dirty_list); |
475 | res->state |= DLM_LOCK_RES_DIRTY; | |
476 | } | |
477 | } | |
478 | ||
479 | ||
480 | /* Launch the NM thread for the mounted volume */ | |
481 | int dlm_launch_thread(struct dlm_ctxt *dlm) | |
482 | { | |
483 | mlog(0, "starting dlm thread...\n"); | |
484 | ||
485 | dlm->dlm_thread_task = kthread_run(dlm_thread, dlm, "dlm_thread"); | |
486 | if (IS_ERR(dlm->dlm_thread_task)) { | |
487 | mlog_errno(PTR_ERR(dlm->dlm_thread_task)); | |
488 | dlm->dlm_thread_task = NULL; | |
489 | return -EINVAL; | |
490 | } | |
491 | ||
492 | return 0; | |
493 | } | |
494 | ||
495 | void dlm_complete_thread(struct dlm_ctxt *dlm) | |
496 | { | |
497 | if (dlm->dlm_thread_task) { | |
498 | mlog(ML_KTHREAD, "waiting for dlm thread to exit\n"); | |
499 | kthread_stop(dlm->dlm_thread_task); | |
500 | dlm->dlm_thread_task = NULL; | |
501 | } | |
502 | } | |
503 | ||
504 | static int dlm_dirty_list_empty(struct dlm_ctxt *dlm) | |
505 | { | |
506 | int empty; | |
507 | ||
508 | spin_lock(&dlm->spinlock); | |
509 | empty = list_empty(&dlm->dirty_list); | |
510 | spin_unlock(&dlm->spinlock); | |
511 | ||
512 | return empty; | |
513 | } | |
514 | ||
515 | static void dlm_flush_asts(struct dlm_ctxt *dlm) | |
516 | { | |
517 | int ret; | |
518 | struct dlm_lock *lock; | |
519 | struct dlm_lock_resource *res; | |
520 | u8 hi; | |
521 | ||
522 | spin_lock(&dlm->ast_lock); | |
523 | while (!list_empty(&dlm->pending_asts)) { | |
524 | lock = list_entry(dlm->pending_asts.next, | |
525 | struct dlm_lock, ast_list); | |
526 | /* get an extra ref on lock */ | |
527 | dlm_lock_get(lock); | |
528 | res = lock->lockres; | |
529 | mlog(0, "delivering an ast for this lockres\n"); | |
530 | ||
531 | BUG_ON(!lock->ast_pending); | |
532 | ||
533 | /* remove from list (including ref) */ | |
534 | list_del_init(&lock->ast_list); | |
535 | dlm_lock_put(lock); | |
536 | spin_unlock(&dlm->ast_lock); | |
537 | ||
538 | if (lock->ml.node != dlm->node_num) { | |
539 | ret = dlm_do_remote_ast(dlm, res, lock); | |
540 | if (ret < 0) | |
541 | mlog_errno(ret); | |
542 | } else | |
543 | dlm_do_local_ast(dlm, res, lock); | |
544 | ||
545 | spin_lock(&dlm->ast_lock); | |
546 | ||
547 | /* possible that another ast was queued while | |
548 | * we were delivering the last one */ | |
549 | if (!list_empty(&lock->ast_list)) { | |
550 | mlog(0, "aha another ast got queued while " | |
551 | "we were finishing the last one. will " | |
552 | "keep the ast_pending flag set.\n"); | |
553 | } else | |
554 | lock->ast_pending = 0; | |
555 | ||
556 | /* drop the extra ref. | |
557 | * this may drop it completely. */ | |
558 | dlm_lock_put(lock); | |
559 | dlm_lockres_release_ast(dlm, res); | |
560 | } | |
561 | ||
562 | while (!list_empty(&dlm->pending_basts)) { | |
563 | lock = list_entry(dlm->pending_basts.next, | |
564 | struct dlm_lock, bast_list); | |
565 | /* get an extra ref on lock */ | |
566 | dlm_lock_get(lock); | |
567 | res = lock->lockres; | |
568 | ||
569 | BUG_ON(!lock->bast_pending); | |
570 | ||
571 | /* get the highest blocked lock, and reset */ | |
572 | spin_lock(&lock->spinlock); | |
573 | BUG_ON(lock->ml.highest_blocked <= LKM_IVMODE); | |
574 | hi = lock->ml.highest_blocked; | |
575 | lock->ml.highest_blocked = LKM_IVMODE; | |
576 | spin_unlock(&lock->spinlock); | |
577 | ||
578 | /* remove from list (including ref) */ | |
579 | list_del_init(&lock->bast_list); | |
580 | dlm_lock_put(lock); | |
581 | spin_unlock(&dlm->ast_lock); | |
582 | ||
583 | mlog(0, "delivering a bast for this lockres " | |
584 | "(blocked = %d\n", hi); | |
585 | ||
586 | if (lock->ml.node != dlm->node_num) { | |
587 | ret = dlm_send_proxy_bast(dlm, res, lock, hi); | |
588 | if (ret < 0) | |
589 | mlog_errno(ret); | |
590 | } else | |
591 | dlm_do_local_bast(dlm, res, lock, hi); | |
592 | ||
593 | spin_lock(&dlm->ast_lock); | |
594 | ||
595 | /* possible that another bast was queued while | |
596 | * we were delivering the last one */ | |
597 | if (!list_empty(&lock->bast_list)) { | |
598 | mlog(0, "aha another bast got queued while " | |
599 | "we were finishing the last one. will " | |
600 | "keep the bast_pending flag set.\n"); | |
601 | } else | |
602 | lock->bast_pending = 0; | |
603 | ||
604 | /* drop the extra ref. | |
605 | * this may drop it completely. */ | |
606 | dlm_lock_put(lock); | |
607 | dlm_lockres_release_ast(dlm, res); | |
608 | } | |
609 | wake_up(&dlm->ast_wq); | |
610 | spin_unlock(&dlm->ast_lock); | |
611 | } | |
612 | ||
613 | ||
614 | #define DLM_THREAD_TIMEOUT_MS (4 * 1000) | |
615 | #define DLM_THREAD_MAX_DIRTY 100 | |
616 | #define DLM_THREAD_MAX_ASTS 10 | |
617 | ||
618 | static int dlm_thread(void *data) | |
619 | { | |
620 | struct dlm_lock_resource *res; | |
621 | struct dlm_ctxt *dlm = data; | |
622 | unsigned long timeout = msecs_to_jiffies(DLM_THREAD_TIMEOUT_MS); | |
623 | ||
624 | mlog(0, "dlm thread running for %s...\n", dlm->name); | |
625 | ||
626 | while (!kthread_should_stop()) { | |
627 | int n = DLM_THREAD_MAX_DIRTY; | |
628 | ||
629 | /* dlm_shutting_down is very point-in-time, but that | |
630 | * doesn't matter as we'll just loop back around if we | |
631 | * get false on the leading edge of a state | |
632 | * transition. */ | |
633 | dlm_run_purge_list(dlm, dlm_shutting_down(dlm)); | |
634 | ||
635 | /* We really don't want to hold dlm->spinlock while | |
636 | * calling dlm_shuffle_lists on each lockres that | |
637 | * needs to have its queues adjusted and AST/BASTs | |
638 | * run. So let's pull each entry off the dirty_list | |
639 | * and drop dlm->spinlock ASAP. Once off the list, | |
640 | * res->spinlock needs to be taken again to protect | |
641 | * the queues while calling dlm_shuffle_lists. */ | |
642 | spin_lock(&dlm->spinlock); | |
643 | while (!list_empty(&dlm->dirty_list)) { | |
644 | int delay = 0; | |
645 | res = list_entry(dlm->dirty_list.next, | |
646 | struct dlm_lock_resource, dirty); | |
647 | ||
648 | /* peel a lockres off, remove it from the list, | |
649 | * unset the dirty flag and drop the dlm lock */ | |
650 | BUG_ON(!res); | |
651 | dlm_lockres_get(res); | |
652 | ||
653 | spin_lock(&res->spinlock); | |
654 | res->state &= ~DLM_LOCK_RES_DIRTY; | |
655 | list_del_init(&res->dirty); | |
656 | spin_unlock(&res->spinlock); | |
657 | spin_unlock(&dlm->spinlock); | |
6ff06a93 KH |
658 | /* Drop dirty_list ref */ |
659 | dlm_lockres_put(res); | |
6714d8e8 KH |
660 | |
661 | /* lockres can be re-dirtied/re-added to the | |
662 | * dirty_list in this gap, but that is ok */ | |
663 | ||
664 | spin_lock(&res->spinlock); | |
665 | if (res->owner != dlm->node_num) { | |
666 | __dlm_print_one_lock_resource(res); | |
667 | mlog(ML_ERROR, "inprog:%s, mig:%s, reco:%s, dirty:%s\n", | |
668 | res->state & DLM_LOCK_RES_IN_PROGRESS ? "yes" : "no", | |
669 | res->state & DLM_LOCK_RES_MIGRATING ? "yes" : "no", | |
670 | res->state & DLM_LOCK_RES_RECOVERING ? "yes" : "no", | |
671 | res->state & DLM_LOCK_RES_DIRTY ? "yes" : "no"); | |
672 | } | |
673 | BUG_ON(res->owner != dlm->node_num); | |
674 | ||
675 | /* it is now ok to move lockreses in these states | |
676 | * to the dirty list, assuming that they will only be | |
677 | * dirty for a short while. */ | |
678 | if (res->state & (DLM_LOCK_RES_IN_PROGRESS | | |
679 | DLM_LOCK_RES_MIGRATING | | |
680 | DLM_LOCK_RES_RECOVERING)) { | |
681 | /* move it to the tail and keep going */ | |
682 | spin_unlock(&res->spinlock); | |
683 | mlog(0, "delaying list shuffling for in-" | |
684 | "progress lockres %.*s, state=%d\n", | |
685 | res->lockname.len, res->lockname.name, | |
686 | res->state); | |
687 | delay = 1; | |
688 | goto in_progress; | |
689 | } | |
690 | ||
691 | /* at this point the lockres is not migrating/ | |
692 | * recovering/in-progress. we have the lockres | |
693 | * spinlock and do NOT have the dlm lock. | |
694 | * safe to reserve/queue asts and run the lists. */ | |
695 | ||
8d79d088 KH |
696 | mlog(0, "calling dlm_shuffle_lists with dlm=%s, " |
697 | "res=%.*s\n", dlm->name, | |
698 | res->lockname.len, res->lockname.name); | |
6714d8e8 KH |
699 | |
700 | /* called while holding lockres lock */ | |
701 | dlm_shuffle_lists(dlm, res); | |
702 | spin_unlock(&res->spinlock); | |
703 | ||
704 | dlm_lockres_calc_usage(dlm, res); | |
705 | ||
706 | in_progress: | |
707 | ||
708 | spin_lock(&dlm->spinlock); | |
709 | /* if the lock was in-progress, stick | |
710 | * it on the back of the list */ | |
711 | if (delay) { | |
6ff06a93 KH |
712 | /* ref for dirty_list */ |
713 | dlm_lockres_get(res); | |
6714d8e8 KH |
714 | spin_lock(&res->spinlock); |
715 | list_add_tail(&res->dirty, &dlm->dirty_list); | |
716 | res->state |= DLM_LOCK_RES_DIRTY; | |
717 | spin_unlock(&res->spinlock); | |
718 | } | |
719 | dlm_lockres_put(res); | |
720 | ||
721 | /* unlikely, but we may need to give time to | |
722 | * other tasks */ | |
723 | if (!--n) { | |
724 | mlog(0, "throttling dlm_thread\n"); | |
725 | break; | |
726 | } | |
727 | } | |
728 | ||
729 | spin_unlock(&dlm->spinlock); | |
730 | dlm_flush_asts(dlm); | |
731 | ||
732 | /* yield and continue right away if there is more work to do */ | |
733 | if (!n) { | |
f85cd47a | 734 | cond_resched(); |
6714d8e8 KH |
735 | continue; |
736 | } | |
737 | ||
738 | wait_event_interruptible_timeout(dlm->dlm_thread_wq, | |
739 | !dlm_dirty_list_empty(dlm) || | |
740 | kthread_should_stop(), | |
741 | timeout); | |
742 | } | |
743 | ||
744 | mlog(0, "quitting DLM thread\n"); | |
745 | return 0; | |
746 | } |