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1 | /* -*- mode: c; c-basic-offset: 8; -*- |
2 | * vim: noexpandtab sw=8 ts=8 sts=0: |
3 | * |
4 | * dlmunlock.c |
5 | * |
6 | * underlying calls for unlocking locks |
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/highmem.h> |
32 | #include <linux/init.h> |
33 | #include <linux/sysctl.h> |
34 | #include <linux/random.h> |
35 | #include <linux/blkdev.h> |
36 | #include <linux/socket.h> |
37 | #include <linux/inet.h> |
38 | #include <linux/spinlock.h> |
39 | #include <linux/delay.h> |
40 | |
41 | #include "cluster/heartbeat.h" |
42 | #include "cluster/nodemanager.h" |
43 | #include "cluster/tcp.h" |
44 | |
45 | #include "dlmapi.h" |
46 | #include "dlmcommon.h" |
47 | |
48 | #define MLOG_MASK_PREFIX ML_DLM |
49 | #include "cluster/masklog.h" |
50 | |
51 | #define DLM_UNLOCK_FREE_LOCK 0x00000001 |
52 | #define DLM_UNLOCK_CALL_AST 0x00000002 |
53 | #define DLM_UNLOCK_REMOVE_LOCK 0x00000004 |
54 | #define DLM_UNLOCK_REGRANT_LOCK 0x00000008 |
55 | #define DLM_UNLOCK_CLEAR_CONVERT_TYPE 0x00000010 |
56 | |
57 | |
58 | static enum dlm_status dlm_get_cancel_actions(struct dlm_ctxt *dlm, |
59 | struct dlm_lock_resource *res, |
60 | struct dlm_lock *lock, |
61 | struct dlm_lockstatus *lksb, |
62 | int *actions); |
63 | static enum dlm_status dlm_get_unlock_actions(struct dlm_ctxt *dlm, |
64 | struct dlm_lock_resource *res, |
65 | struct dlm_lock *lock, |
66 | struct dlm_lockstatus *lksb, |
67 | int *actions); |
68 | |
69 | static enum dlm_status dlm_send_remote_unlock_request(struct dlm_ctxt *dlm, |
70 | struct dlm_lock_resource *res, |
71 | struct dlm_lock *lock, |
72 | struct dlm_lockstatus *lksb, |
73 | int flags, |
74 | u8 owner); |
75 | |
76 | |
77 | /* |
78 | * according to the spec: |
79 | * http://opendlm.sourceforge.net/cvsmirror/opendlm/docs/dlmbook_final.pdf |
80 | * |
81 | * flags & LKM_CANCEL != 0: must be converting or blocked |
82 | * flags & LKM_CANCEL == 0: must be granted |
83 | * |
84 | * So to unlock a converting lock, you must first cancel the |
85 | * convert (passing LKM_CANCEL in flags), then call the unlock |
86 | * again (with no LKM_CANCEL in flags). |
87 | */ |
88 | |
89 | |
90 | /* |
91 | * locking: |
92 | * caller needs: none |
93 | * taken: res->spinlock and lock->spinlock taken and dropped |
94 | * held on exit: none |
95 | * returns: DLM_NORMAL, DLM_NOLOCKMGR, status from network |
96 | * all callers should have taken an extra ref on lock coming in |
97 | */ |
98 | static enum dlm_status dlmunlock_common(struct dlm_ctxt *dlm, |
99 | struct dlm_lock_resource *res, |
100 | struct dlm_lock *lock, |
101 | struct dlm_lockstatus *lksb, |
102 | int flags, int *call_ast, |
103 | int master_node) |
104 | { |
105 | enum dlm_status status; |
106 | int actions = 0; |
107 | int in_use; |
108 | u8 owner; |
109 | |
110 | mlog(0, "master_node = %d, valblk = %d\n", master_node, |
111 | flags & LKM_VALBLK); |
112 | |
113 | if (master_node) |
114 | BUG_ON(res->owner != dlm->node_num); |
115 | else |
116 | BUG_ON(res->owner == dlm->node_num); |
117 | |
118 | spin_lock(&dlm->ast_lock); |
119 | /* We want to be sure that we're not freeing a lock |
120 | * that still has AST's pending... */ |
121 | in_use = !list_empty(&lock->ast_list); |
122 | spin_unlock(&dlm->ast_lock); |
123 | if (in_use && !(flags & LKM_CANCEL)) { |
124 | mlog(ML_ERROR, "lockres %.*s: Someone is calling dlmunlock " |
125 | "while waiting for an ast!", res->lockname.len, |
126 | res->lockname.name); |
127 | return DLM_BADPARAM; |
128 | } |
129 | |
130 | spin_lock(&res->spinlock); |
131 | if (res->state & DLM_LOCK_RES_IN_PROGRESS) { |
132 | if (master_node && !(flags & LKM_CANCEL)) { |
133 | mlog(ML_ERROR, "lockres in progress!\n"); |
134 | spin_unlock(&res->spinlock); |
135 | return DLM_FORWARD; |
136 | } |
137 | /* ok for this to sleep if not in a network handler */ |
138 | __dlm_wait_on_lockres(res); |
139 | res->state |= DLM_LOCK_RES_IN_PROGRESS; |
140 | } |
141 | spin_lock(&lock->spinlock); |
142 | |
143 | if (res->state & DLM_LOCK_RES_RECOVERING) { |
144 | status = DLM_RECOVERING; |
145 | goto leave; |
146 | } |
147 | |
148 | if (res->state & DLM_LOCK_RES_MIGRATING) { |
149 | status = DLM_MIGRATING; |
150 | goto leave; |
151 | } |
152 | |
153 | /* see above for what the spec says about |
154 | * LKM_CANCEL and the lock queue state */ |
155 | if (flags & LKM_CANCEL) |
156 | status = dlm_get_cancel_actions(dlm, res, lock, lksb, &actions); |
157 | else |
158 | status = dlm_get_unlock_actions(dlm, res, lock, lksb, &actions); |
159 | |
160 | if (status != DLM_NORMAL && (status != DLM_CANCELGRANT || !master_node)) |
161 | goto leave; |
162 | |
163 | /* By now this has been masked out of cancel requests. */ |
164 | if (flags & LKM_VALBLK) { |
165 | /* make the final update to the lvb */ |
166 | if (master_node) |
167 | memcpy(res->lvb, lksb->lvb, DLM_LVB_LEN); |
168 | else |
169 | flags |= LKM_PUT_LVB; /* let the send function |
170 | * handle it. */ |
171 | } |
172 | |
173 | if (!master_node) { |
174 | owner = res->owner; |
175 | /* drop locks and send message */ |
176 | if (flags & LKM_CANCEL) |
177 | lock->cancel_pending = 1; |
178 | else |
179 | lock->unlock_pending = 1; |
180 | spin_unlock(&lock->spinlock); |
181 | spin_unlock(&res->spinlock); |
182 | status = dlm_send_remote_unlock_request(dlm, res, lock, lksb, |
183 | flags, owner); |
184 | spin_lock(&res->spinlock); |
185 | spin_lock(&lock->spinlock); |
186 | /* if the master told us the lock was already granted, |
187 | * let the ast handle all of these actions */ |
188 | if (status == DLM_CANCELGRANT) { |
189 | actions &= ~(DLM_UNLOCK_REMOVE_LOCK| |
190 | DLM_UNLOCK_REGRANT_LOCK| |
191 | DLM_UNLOCK_CLEAR_CONVERT_TYPE); |
192 | } else if (status == DLM_RECOVERING || |
193 | status == DLM_MIGRATING || |
194 | status == DLM_FORWARD) { |
195 | /* must clear the actions because this unlock |
196 | * is about to be retried. cannot free or do |
197 | * any list manipulation. */ |
198 | mlog(0, "%s:%.*s: clearing actions, %s\n", |
199 | dlm->name, res->lockname.len, |
200 | res->lockname.name, |
201 | status==DLM_RECOVERING?"recovering": |
202 | (status==DLM_MIGRATING?"migrating": |
203 | "forward")); |
204 | actions = 0; |
205 | } |
206 | if (flags & LKM_CANCEL) |
207 | lock->cancel_pending = 0; |
208 | else |
209 | lock->unlock_pending = 0; |
210 | |
211 | } |
212 | |
213 | /* get an extra ref on lock. if we are just switching |
214 | * lists here, we dont want the lock to go away. */ |
215 | dlm_lock_get(lock); |
216 | |
217 | if (actions & DLM_UNLOCK_REMOVE_LOCK) { |
218 | list_del_init(&lock->list); |
219 | dlm_lock_put(lock); |
220 | } |
221 | if (actions & DLM_UNLOCK_REGRANT_LOCK) { |
222 | dlm_lock_get(lock); |
223 | list_add_tail(&lock->list, &res->granted); |
224 | } |
225 | if (actions & DLM_UNLOCK_CLEAR_CONVERT_TYPE) { |
226 | mlog(0, "clearing convert_type at %smaster node\n", |
227 | master_node ? "" : "non-"); |
228 | lock->ml.convert_type = LKM_IVMODE; |
229 | } |
230 | |
231 | /* remove the extra ref on lock */ |
232 | dlm_lock_put(lock); |
233 | |
234 | leave: |
235 | res->state &= ~DLM_LOCK_RES_IN_PROGRESS; |
236 | if (!dlm_lock_on_list(&res->converting, lock)) |
237 | BUG_ON(lock->ml.convert_type != LKM_IVMODE); |
238 | else |
239 | BUG_ON(lock->ml.convert_type == LKM_IVMODE); |
240 | spin_unlock(&lock->spinlock); |
241 | spin_unlock(&res->spinlock); |
242 | wake_up(&res->wq); |
243 | |
244 | /* let the caller's final dlm_lock_put handle the actual kfree */ |
245 | if (actions & DLM_UNLOCK_FREE_LOCK) { |
246 | /* this should always be coupled with list removal */ |
247 | BUG_ON(!(actions & DLM_UNLOCK_REMOVE_LOCK)); |
248 | mlog(0, "lock %u:%llu should be gone now! refs=%d\n", |
249 | dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)), |
250 | dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)), |
251 | atomic_read(&lock->lock_refs.refcount)-1); |
252 | dlm_lock_put(lock); |
253 | } |
254 | if (actions & DLM_UNLOCK_CALL_AST) |
255 | *call_ast = 1; |
256 | |
257 | /* if cancel or unlock succeeded, lvb work is done */ |
258 | if (status == DLM_NORMAL) |
259 | lksb->flags &= ~(DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB); |
260 | |
261 | return status; |
262 | } |
263 | |
264 | void dlm_commit_pending_unlock(struct dlm_lock_resource *res, |
265 | struct dlm_lock *lock) |
266 | { |
267 | /* leave DLM_LKSB_PUT_LVB on the lksb so any final |
268 | * update of the lvb will be sent to the new master */ |
269 | list_del_init(&lock->list); |
270 | } |
271 | |
272 | void dlm_commit_pending_cancel(struct dlm_lock_resource *res, |
273 | struct dlm_lock *lock) |
274 | { |
275 | list_move_tail(&lock->list, &res->granted); |
276 | lock->ml.convert_type = LKM_IVMODE; |
277 | } |
278 | |
279 | |
280 | static inline enum dlm_status dlmunlock_master(struct dlm_ctxt *dlm, |
281 | struct dlm_lock_resource *res, |
282 | struct dlm_lock *lock, |
283 | struct dlm_lockstatus *lksb, |
284 | int flags, |
285 | int *call_ast) |
286 | { |
287 | return dlmunlock_common(dlm, res, lock, lksb, flags, call_ast, 1); |
288 | } |
289 | |
290 | static inline enum dlm_status dlmunlock_remote(struct dlm_ctxt *dlm, |
291 | struct dlm_lock_resource *res, |
292 | struct dlm_lock *lock, |
293 | struct dlm_lockstatus *lksb, |
294 | int flags, int *call_ast) |
295 | { |
296 | return dlmunlock_common(dlm, res, lock, lksb, flags, call_ast, 0); |
297 | } |
298 | |
299 | /* |
300 | * locking: |
301 | * caller needs: none |
302 | * taken: none |
303 | * held on exit: none |
304 | * returns: DLM_NORMAL, DLM_NOLOCKMGR, status from network |
305 | */ |
306 | static enum dlm_status dlm_send_remote_unlock_request(struct dlm_ctxt *dlm, |
307 | struct dlm_lock_resource *res, |
308 | struct dlm_lock *lock, |
309 | struct dlm_lockstatus *lksb, |
310 | int flags, |
311 | u8 owner) |
312 | { |
313 | struct dlm_unlock_lock unlock; |
314 | int tmpret; |
315 | enum dlm_status ret; |
316 | int status = 0; |
317 | struct kvec vec[2]; |
318 | size_t veclen = 1; |
319 | |
320 | mlog_entry("%.*s\n", res->lockname.len, res->lockname.name); |
321 | |
322 | if (owner == dlm->node_num) { |
323 | /* ended up trying to contact ourself. this means |
324 | * that the lockres had been remote but became local |
325 | * via a migration. just retry it, now as local */ |
326 | mlog(0, "%s:%.*s: this node became the master due to a " |
327 | "migration, re-evaluate now\n", dlm->name, |
328 | res->lockname.len, res->lockname.name); |
329 | return DLM_FORWARD; |
330 | } |
331 | |
332 | memset(&unlock, 0, sizeof(unlock)); |
333 | unlock.node_idx = dlm->node_num; |
334 | unlock.flags = cpu_to_be32(flags); |
335 | unlock.cookie = lock->ml.cookie; |
336 | unlock.namelen = res->lockname.len; |
337 | memcpy(unlock.name, res->lockname.name, unlock.namelen); |
338 | |
339 | vec[0].iov_len = sizeof(struct dlm_unlock_lock); |
340 | vec[0].iov_base = &unlock; |
341 | |
342 | if (flags & LKM_PUT_LVB) { |
343 | /* extra data to send if we are updating lvb */ |
344 | vec[1].iov_len = DLM_LVB_LEN; |
345 | vec[1].iov_base = lock->lksb->lvb; |
346 | veclen++; |
347 | } |
348 | |
349 | tmpret = o2net_send_message_vec(DLM_UNLOCK_LOCK_MSG, dlm->key, |
350 | vec, veclen, owner, &status); |
351 | if (tmpret >= 0) { |
352 | // successfully sent and received |
353 | if (status == DLM_FORWARD) |
354 | mlog(0, "master was in-progress. retry\n"); |
355 | ret = status; |
356 | } else { |
357 | mlog_errno(tmpret); |
358 | if (dlm_is_host_down(tmpret)) { |
359 | /* NOTE: this seems strange, but it is what we want. |
360 | * when the master goes down during a cancel or |
361 | * unlock, the recovery code completes the operation |
362 | * as if the master had not died, then passes the |
363 | * updated state to the recovery master. this thread |
364 | * just needs to finish out the operation and call |
365 | * the unlockast. */ |
366 | ret = DLM_NORMAL; |
367 | } else { |
368 | /* something bad. this will BUG in ocfs2 */ |
369 | ret = dlm_err_to_dlm_status(tmpret); |
370 | } |
371 | } |
372 | |
373 | return ret; |
374 | } |
375 | |
376 | /* |
377 | * locking: |
378 | * caller needs: none |
379 | * taken: takes and drops res->spinlock |
380 | * held on exit: none |
381 | * returns: DLM_NORMAL, DLM_BADARGS, DLM_IVLOCKID, |
382 | * return value from dlmunlock_master |
383 | */ |
384 | int dlm_unlock_lock_handler(struct o2net_msg *msg, u32 len, void *data, |
385 | void **ret_data) |
386 | { |
387 | struct dlm_ctxt *dlm = data; |
388 | struct dlm_unlock_lock *unlock = (struct dlm_unlock_lock *)msg->buf; |
389 | struct dlm_lock_resource *res = NULL; |
390 | struct list_head *iter; |
391 | struct dlm_lock *lock = NULL; |
392 | enum dlm_status status = DLM_NORMAL; |
393 | int found = 0, i; |
394 | struct dlm_lockstatus *lksb = NULL; |
395 | int ignore; |
396 | u32 flags; |
397 | struct list_head *queue; |
398 | |
399 | flags = be32_to_cpu(unlock->flags); |
400 | |
401 | if (flags & LKM_GET_LVB) { |
402 | mlog(ML_ERROR, "bad args! GET_LVB specified on unlock!\n"); |
403 | return DLM_BADARGS; |
404 | } |
405 | |
406 | if ((flags & (LKM_PUT_LVB|LKM_CANCEL)) == (LKM_PUT_LVB|LKM_CANCEL)) { |
407 | mlog(ML_ERROR, "bad args! cannot modify lvb on a CANCEL " |
408 | "request!\n"); |
409 | return DLM_BADARGS; |
410 | } |
411 | |
412 | if (unlock->namelen > DLM_LOCKID_NAME_MAX) { |
413 | mlog(ML_ERROR, "Invalid name length in unlock handler!\n"); |
414 | return DLM_IVBUFLEN; |
415 | } |
416 | |
417 | if (!dlm_grab(dlm)) |
418 | return DLM_REJECTED; |
419 | |
420 | mlog_bug_on_msg(!dlm_domain_fully_joined(dlm), |
421 | "Domain %s not fully joined!\n", dlm->name); |
422 | |
423 | mlog(0, "lvb: %s\n", flags & LKM_PUT_LVB ? "put lvb" : "none"); |
424 | |
425 | res = dlm_lookup_lockres(dlm, unlock->name, unlock->namelen); |
426 | if (!res) { |
427 | /* We assume here that a no lock resource simply means |
428 | * it was migrated away and destroyed before the other |
429 | * node could detect it. */ |
430 | mlog(0, "returning DLM_FORWARD -- res no longer exists\n"); |
431 | status = DLM_FORWARD; |
432 | goto not_found; |
433 | } |
434 | |
435 | queue=&res->granted; |
436 | found = 0; |
437 | spin_lock(&res->spinlock); |
438 | if (res->state & DLM_LOCK_RES_RECOVERING) { |
439 | spin_unlock(&res->spinlock); |
440 | mlog(0, "returning DLM_RECOVERING\n"); |
441 | status = DLM_RECOVERING; |
442 | goto leave; |
443 | } |
444 | |
445 | if (res->state & DLM_LOCK_RES_MIGRATING) { |
446 | spin_unlock(&res->spinlock); |
447 | mlog(0, "returning DLM_MIGRATING\n"); |
448 | status = DLM_MIGRATING; |
449 | goto leave; |
450 | } |
451 | |
452 | if (res->owner != dlm->node_num) { |
453 | spin_unlock(&res->spinlock); |
454 | mlog(0, "returning DLM_FORWARD -- not master\n"); |
455 | status = DLM_FORWARD; |
456 | goto leave; |
457 | } |
458 | |
459 | for (i=0; i<3; i++) { |
460 | list_for_each(iter, queue) { |
461 | lock = list_entry(iter, struct dlm_lock, list); |
462 | if (lock->ml.cookie == unlock->cookie && |
463 | lock->ml.node == unlock->node_idx) { |
464 | dlm_lock_get(lock); |
465 | found = 1; |
466 | break; |
467 | } |
468 | } |
469 | if (found) |
470 | break; |
471 | /* scan granted -> converting -> blocked queues */ |
472 | queue++; |
473 | } |
474 | spin_unlock(&res->spinlock); |
475 | if (!found) { |
476 | status = DLM_IVLOCKID; |
477 | goto not_found; |
478 | } |
479 | |
480 | /* lock was found on queue */ |
481 | lksb = lock->lksb; |
482 | if (flags & (LKM_VALBLK|LKM_PUT_LVB) && |
483 | lock->ml.type != LKM_EXMODE) |
484 | flags &= ~(LKM_VALBLK|LKM_PUT_LVB); |
485 | |
486 | /* unlockast only called on originating node */ |
487 | if (flags & LKM_PUT_LVB) { |
488 | lksb->flags |= DLM_LKSB_PUT_LVB; |
489 | memcpy(&lksb->lvb[0], &unlock->lvb[0], DLM_LVB_LEN); |
490 | } |
491 | |
492 | /* if this is in-progress, propagate the DLM_FORWARD |
493 | * all the way back out */ |
494 | status = dlmunlock_master(dlm, res, lock, lksb, flags, &ignore); |
495 | if (status == DLM_FORWARD) |
496 | mlog(0, "lockres is in progress\n"); |
497 | |
498 | if (flags & LKM_PUT_LVB) |
499 | lksb->flags &= ~DLM_LKSB_PUT_LVB; |
500 | |
501 | dlm_lockres_calc_usage(dlm, res); |
502 | dlm_kick_thread(dlm, res); |
503 | |
504 | not_found: |
505 | if (!found) |
506 | mlog(ML_ERROR, "failed to find lock to unlock! " |
507 | "cookie=%u:%llu\n", |
508 | dlm_get_lock_cookie_node(be64_to_cpu(unlock->cookie)), |
509 | dlm_get_lock_cookie_seq(be64_to_cpu(unlock->cookie))); |
510 | else |
511 | dlm_lock_put(lock); |
512 | |
513 | leave: |
514 | if (res) |
515 | dlm_lockres_put(res); |
516 | |
517 | dlm_put(dlm); |
518 | |
519 | return status; |
520 | } |
521 | |
522 | |
523 | static enum dlm_status dlm_get_cancel_actions(struct dlm_ctxt *dlm, |
524 | struct dlm_lock_resource *res, |
525 | struct dlm_lock *lock, |
526 | struct dlm_lockstatus *lksb, |
527 | int *actions) |
528 | { |
529 | enum dlm_status status; |
530 | |
531 | if (dlm_lock_on_list(&res->blocked, lock)) { |
532 | /* cancel this outright */ |
533 | status = DLM_NORMAL; |
534 | *actions = (DLM_UNLOCK_CALL_AST | |
535 | DLM_UNLOCK_REMOVE_LOCK); |
536 | } else if (dlm_lock_on_list(&res->converting, lock)) { |
537 | /* cancel the request, put back on granted */ |
538 | status = DLM_NORMAL; |
539 | *actions = (DLM_UNLOCK_CALL_AST | |
540 | DLM_UNLOCK_REMOVE_LOCK | |
541 | DLM_UNLOCK_REGRANT_LOCK | |
542 | DLM_UNLOCK_CLEAR_CONVERT_TYPE); |
543 | } else if (dlm_lock_on_list(&res->granted, lock)) { |
544 | /* too late, already granted. */ |
545 | status = DLM_CANCELGRANT; |
546 | *actions = DLM_UNLOCK_CALL_AST; |
547 | } else { |
548 | mlog(ML_ERROR, "lock to cancel is not on any list!\n"); |
549 | status = DLM_IVLOCKID; |
550 | *actions = 0; |
551 | } |
552 | return status; |
553 | } |
554 | |
555 | static enum dlm_status dlm_get_unlock_actions(struct dlm_ctxt *dlm, |
556 | struct dlm_lock_resource *res, |
557 | struct dlm_lock *lock, |
558 | struct dlm_lockstatus *lksb, |
559 | int *actions) |
560 | { |
561 | enum dlm_status status; |
562 | |
563 | /* unlock request */ |
564 | if (!dlm_lock_on_list(&res->granted, lock)) { |
565 | status = DLM_DENIED; |
566 | dlm_error(status); |
567 | *actions = 0; |
568 | } else { |
569 | /* unlock granted lock */ |
570 | status = DLM_NORMAL; |
571 | *actions = (DLM_UNLOCK_FREE_LOCK | |
572 | DLM_UNLOCK_CALL_AST | |
573 | DLM_UNLOCK_REMOVE_LOCK); |
574 | } |
575 | return status; |
576 | } |
577 | |
578 | /* there seems to be no point in doing this async |
579 | * since (even for the remote case) there is really |
580 | * no work to queue up... so just do it and fire the |
581 | * unlockast by hand when done... */ |
582 | enum dlm_status dlmunlock(struct dlm_ctxt *dlm, struct dlm_lockstatus *lksb, |
583 | int flags, dlm_astunlockfunc_t *unlockast, void *data) |
584 | { |
585 | enum dlm_status status; |
586 | struct dlm_lock_resource *res; |
587 | struct dlm_lock *lock = NULL; |
588 | int call_ast, is_master; |
589 | |
590 | mlog_entry_void(); |
591 | |
592 | if (!lksb) { |
593 | dlm_error(DLM_BADARGS); |
594 | return DLM_BADARGS; |
595 | } |
596 | |
597 | if (flags & ~(LKM_CANCEL | LKM_VALBLK | LKM_INVVALBLK)) { |
598 | dlm_error(DLM_BADPARAM); |
599 | return DLM_BADPARAM; |
600 | } |
601 | |
602 | if ((flags & (LKM_VALBLK | LKM_CANCEL)) == (LKM_VALBLK | LKM_CANCEL)) { |
603 | mlog(0, "VALBLK given with CANCEL: ignoring VALBLK\n"); |
604 | flags &= ~LKM_VALBLK; |
605 | } |
606 | |
607 | if (!lksb->lockid || !lksb->lockid->lockres) { |
608 | dlm_error(DLM_BADPARAM); |
609 | return DLM_BADPARAM; |
610 | } |
611 | |
612 | lock = lksb->lockid; |
613 | BUG_ON(!lock); |
614 | dlm_lock_get(lock); |
615 | |
616 | res = lock->lockres; |
617 | BUG_ON(!res); |
618 | dlm_lockres_get(res); |
619 | retry: |
620 | call_ast = 0; |
621 | /* need to retry up here because owner may have changed */ |
622 | mlog(0, "lock=%p res=%p\n", lock, res); |
623 | |
624 | spin_lock(&res->spinlock); |
625 | is_master = (res->owner == dlm->node_num); |
626 | if (flags & LKM_VALBLK && lock->ml.type != LKM_EXMODE) |
627 | flags &= ~LKM_VALBLK; |
628 | spin_unlock(&res->spinlock); |
629 | |
630 | if (is_master) { |
631 | status = dlmunlock_master(dlm, res, lock, lksb, flags, |
632 | &call_ast); |
633 | mlog(0, "done calling dlmunlock_master: returned %d, " |
634 | "call_ast is %d\n", status, call_ast); |
635 | } else { |
636 | status = dlmunlock_remote(dlm, res, lock, lksb, flags, |
637 | &call_ast); |
638 | mlog(0, "done calling dlmunlock_remote: returned %d, " |
639 | "call_ast is %d\n", status, call_ast); |
640 | } |
641 | |
642 | if (status == DLM_RECOVERING || |
643 | status == DLM_MIGRATING || |
644 | status == DLM_FORWARD) { |
645 | /* We want to go away for a tiny bit to allow recovery |
646 | * / migration to complete on this resource. I don't |
647 | * know of any wait queue we could sleep on as this |
648 | * may be happening on another node. Perhaps the |
649 | * proper solution is to queue up requests on the |
650 | * other end? */ |
651 | |
652 | /* do we want to yield(); ?? */ |
653 | msleep(50); |
654 | |
655 | mlog(0, "retrying unlock due to pending recovery/" |
656 | "migration/in-progress\n"); |
657 | goto retry; |
658 | } |
659 | |
660 | if (call_ast) { |
661 | mlog(0, "calling unlockast(%p, %d)\n", data, status); |
662 | if (is_master) { |
663 | /* it is possible that there is one last bast |
664 | * pending. make sure it is flushed, then |
665 | * call the unlockast. |
666 | * not an issue if this is a mastered remotely, |
667 | * since this lock has been removed from the |
668 | * lockres queues and cannot be found. */ |
669 | dlm_kick_thread(dlm, NULL); |
670 | wait_event(dlm->ast_wq, |
671 | dlm_lock_basts_flushed(dlm, lock)); |
672 | } |
673 | (*unlockast)(data, status); |
674 | } |
675 | |
676 | if (status == DLM_CANCELGRANT) |
677 | status = DLM_NORMAL; |
678 | |
679 | if (status == DLM_NORMAL) { |
680 | mlog(0, "kicking the thread\n"); |
681 | dlm_kick_thread(dlm, res); |
682 | } else |
683 | dlm_error(status); |
684 | |
685 | dlm_lockres_calc_usage(dlm, res); |
686 | dlm_lockres_put(res); |
687 | dlm_lock_put(lock); |
688 | |
689 | mlog(0, "returning status=%d!\n", status); |
690 | return status; |
691 | } |
692 | EXPORT_SYMBOL_GPL(dlmunlock); |
693 | |
694 |
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v2.6.34-rc5
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