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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); |
6714d8e8 KH |
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); | |
5c2c9d38 | 79 | __set_current_state(TASK_RUNNING); |
6714d8e8 KH |
80 | } |
81 | ||
ba2bf218 | 82 | int __dlm_lockres_has_locks(struct dlm_lock_resource *res) |
6714d8e8 KH |
83 | { |
84 | if (list_empty(&res->granted) && | |
85 | list_empty(&res->converting) && | |
ba2bf218 KH |
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) && | |
ddc09c8d | 98 | (list_empty(&res->dirty) && !(res->state & DLM_LOCK_RES_DIRTY))) { |
ba2bf218 KH |
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 | } | |
6714d8e8 KH |
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)) { | |
ba2bf218 KH |
126 | mlog(0, "putting lockres %.*s:%p onto purge list\n", |
127 | res->lockname.len, res->lockname.name, res); | |
6714d8e8 KH |
128 | |
129 | res->last_used = jiffies; | |
ba2bf218 | 130 | dlm_lockres_get(res); |
6714d8e8 KH |
131 | list_add_tail(&res->purge, &dlm->purge_list); |
132 | dlm->purge_count++; | |
133 | } | |
134 | } else if (!list_empty(&res->purge)) { | |
ba2bf218 KH |
135 | mlog(0, "removing lockres %.*s:%p from purge list, owner=%u\n", |
136 | res->lockname.len, res->lockname.name, res, res->owner); | |
6714d8e8 KH |
137 | |
138 | list_del_init(&res->purge); | |
ba2bf218 | 139 | dlm_lockres_put(res); |
6714d8e8 KH |
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 | ||
faf0ec9f AB |
157 | static int dlm_purge_lockres(struct dlm_ctxt *dlm, |
158 | struct dlm_lock_resource *res) | |
6714d8e8 KH |
159 | { |
160 | int master; | |
ba2bf218 | 161 | int ret = 0; |
6714d8e8 | 162 | |
ba2bf218 KH |
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); | |
6714d8e8 | 171 | if (!master) |
ba2bf218 KH |
172 | res->state |= DLM_LOCK_RES_DROPPING_REF; |
173 | spin_unlock(&res->spinlock); | |
6714d8e8 | 174 | |
ba2bf218 KH |
175 | mlog(0, "purging lockres %.*s, master = %d\n", res->lockname.len, |
176 | res->lockname.name, master); | |
177 | ||
178 | if (!master) { | |
c824c3c7 SM |
179 | /* drop spinlock... retake below */ |
180 | spin_unlock(&dlm->spinlock); | |
181 | ||
3b8118cf KH |
182 | spin_lock(&res->spinlock); |
183 | /* This ensures that clear refmap is sent after the set */ | |
7dc102b7 | 184 | __dlm_wait_on_lockres_flags(res, DLM_LOCK_RES_SETREF_INPROG); |
3b8118cf | 185 | spin_unlock(&res->spinlock); |
c824c3c7 | 186 | |
ba2bf218 KH |
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); | |
6714d8e8 KH |
197 | } |
198 | ||
ba2bf218 KH |
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); | |
6714d8e8 KH |
205 | dlm->purge_count--; |
206 | } | |
ba2bf218 | 207 | __dlm_unhash_lockres(res); |
6714d8e8 | 208 | |
ba2bf218 KH |
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); | |
8b219809 | 216 | } |
ba2bf218 | 217 | return 0; |
8b219809 KH |
218 | } |
219 | ||
6714d8e8 KH |
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 | ||
78062cb2 | 261 | dlm_lockres_get(lockres); |
6714d8e8 KH |
262 | |
263 | /* This may drop and reacquire the dlm spinlock if it | |
264 | * has to do migration. */ | |
ba2bf218 KH |
265 | if (dlm_purge_lockres(dlm, lockres)) |
266 | BUG(); | |
78062cb2 | 267 | |
3fca0894 | 268 | dlm_lockres_put(lockres); |
6714d8e8 KH |
269 | |
270 | /* Avoid adding any scheduling latencies */ | |
271 | cond_resched_lock(&dlm->spinlock); | |
272 | } | |
273 | ||
274 | spin_unlock(&dlm->spinlock); | |
275 | } | |
276 | ||
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; | |
f116629d | 360 | list_move_tail(&target->list, &res->granted); |
6714d8e8 KH |
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 | |
f116629d | 421 | list_move_tail(&target->list, &res->granted); |
6714d8e8 KH |
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 * */ | |
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 | ||
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 */ | |
ddc09c8d KH |
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 | } | |
6714d8e8 KH |
471 | } |
472 | } | |
473 | ||
474 | ||
475 | /* Launch the NM thread for the mounted volume */ | |
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 | ||
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 | ||
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 | ||
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 | ||
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); | |
ddc09c8d | 649 | /* We clear the DLM_LOCK_RES_DIRTY state once we shuffle lists below */ |
6714d8e8 KH |
650 | list_del_init(&res->dirty); |
651 | spin_unlock(&res->spinlock); | |
652 | spin_unlock(&dlm->spinlock); | |
6ff06a93 KH |
653 | /* Drop dirty_list ref */ |
654 | dlm_lockres_put(res); | |
6714d8e8 KH |
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. */ | |
ddc09c8d | 673 | BUG_ON(res->state & DLM_LOCK_RES_MIGRATING); |
6714d8e8 | 674 | if (res->state & (DLM_LOCK_RES_IN_PROGRESS | |
6714d8e8 KH |
675 | DLM_LOCK_RES_RECOVERING)) { |
676 | /* move it to the tail and keep going */ | |
ddc09c8d | 677 | res->state &= ~DLM_LOCK_RES_DIRTY; |
6714d8e8 KH |
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 | ||
8d79d088 KH |
692 | mlog(0, "calling dlm_shuffle_lists with dlm=%s, " |
693 | "res=%.*s\n", dlm->name, | |
694 | res->lockname.len, res->lockname.name); | |
6714d8e8 KH |
695 | |
696 | /* called while holding lockres lock */ | |
697 | dlm_shuffle_lists(dlm, res); | |
ddc09c8d | 698 | res->state &= ~DLM_LOCK_RES_DIRTY; |
6714d8e8 KH |
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); | |
ddc09c8d | 710 | __dlm_dirty_lockres(dlm, res); |
6714d8e8 KH |
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) { | |
f85cd47a | 728 | cond_resched(); |
6714d8e8 KH |
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 | } |