Line data Source code
1 : /*
2 : Unix SMB/CIFS implementation.
3 : global locks based on dbwrap and messaging
4 : Copyright (C) 2009 by Volker Lendecke
5 :
6 : This program is free software; you can redistribute it and/or modify
7 : it under the terms of the GNU General Public License as published by
8 : the Free Software Foundation; either version 3 of the License, or
9 : (at your option) any later version.
10 :
11 : This program is distributed in the hope that it will be useful,
12 : but WITHOUT ANY WARRANTY; without even the implied warranty of
13 : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 : GNU General Public License for more details.
15 :
16 : You should have received a copy of the GNU General Public License
17 : along with this program. If not, see <http://www.gnu.org/licenses/>.
18 : */
19 :
20 : #include "replace.h"
21 : #include "system/filesys.h"
22 : #include "lib/util/server_id.h"
23 : #include "lib/util/debug.h"
24 : #include "lib/util/talloc_stack.h"
25 : #include "lib/util/samba_util.h"
26 : #include "lib/util_path.h"
27 : #include "dbwrap/dbwrap.h"
28 : #include "dbwrap/dbwrap_open.h"
29 : #include "dbwrap/dbwrap_watch.h"
30 : #include "g_lock.h"
31 : #include "util_tdb.h"
32 : #include "../lib/util/tevent_ntstatus.h"
33 : #include "messages.h"
34 : #include "serverid.h"
35 :
36 : struct g_lock_ctx {
37 : struct db_context *db;
38 : struct messaging_context *msg;
39 : enum dbwrap_lock_order lock_order;
40 : bool busy;
41 : };
42 :
43 : struct g_lock {
44 : struct server_id exclusive;
45 : size_t num_shared;
46 : uint8_t *shared;
47 : uint64_t unique_lock_epoch;
48 : uint64_t unique_data_epoch;
49 : size_t datalen;
50 : uint8_t *data;
51 : };
52 :
53 1879844 : static bool g_lock_parse(uint8_t *buf, size_t buflen, struct g_lock *lck)
54 : {
55 4909 : struct server_id exclusive;
56 4909 : size_t num_shared, shared_len;
57 4909 : uint64_t unique_lock_epoch;
58 4909 : uint64_t unique_data_epoch;
59 :
60 1879844 : if (buflen < (SERVER_ID_BUF_LENGTH + /* exclusive */
61 : sizeof(uint64_t) + /* seqnum */
62 : sizeof(uint32_t))) { /* num_shared */
63 1246482 : struct g_lock ret = {
64 : .exclusive.pid = 0,
65 415494 : .unique_lock_epoch = generate_unique_u64(0),
66 415494 : .unique_data_epoch = generate_unique_u64(0),
67 : };
68 415494 : *lck = ret;
69 415494 : return true;
70 : }
71 :
72 1464350 : server_id_get(&exclusive, buf);
73 1464350 : buf += SERVER_ID_BUF_LENGTH;
74 1464350 : buflen -= SERVER_ID_BUF_LENGTH;
75 :
76 1464350 : unique_lock_epoch = BVAL(buf, 0);
77 1464350 : buf += sizeof(uint64_t);
78 1464350 : buflen -= sizeof(uint64_t);
79 :
80 1464350 : unique_data_epoch = BVAL(buf, 0);
81 1464350 : buf += sizeof(uint64_t);
82 1464350 : buflen -= sizeof(uint64_t);
83 :
84 1464350 : num_shared = IVAL(buf, 0);
85 1464350 : buf += sizeof(uint32_t);
86 1464350 : buflen -= sizeof(uint32_t);
87 :
88 1464350 : if (num_shared > buflen/SERVER_ID_BUF_LENGTH) {
89 0 : DBG_DEBUG("num_shared=%zu, buflen=%zu\n",
90 : num_shared,
91 : buflen);
92 0 : return false;
93 : }
94 :
95 1464350 : shared_len = num_shared * SERVER_ID_BUF_LENGTH;
96 :
97 1464350 : *lck = (struct g_lock) {
98 : .exclusive = exclusive,
99 : .num_shared = num_shared,
100 : .shared = buf,
101 : .unique_lock_epoch = unique_lock_epoch,
102 : .unique_data_epoch = unique_data_epoch,
103 1464350 : .datalen = buflen-shared_len,
104 1464350 : .data = buf+shared_len,
105 : };
106 :
107 1464350 : return true;
108 : }
109 :
110 76 : static void g_lock_get_shared(const struct g_lock *lck,
111 : size_t i,
112 : struct server_id *shared)
113 : {
114 69 : if (i >= lck->num_shared) {
115 0 : abort();
116 : }
117 74 : server_id_get(shared, lck->shared + i*SERVER_ID_BUF_LENGTH);
118 69 : }
119 :
120 17 : static void g_lock_del_shared(struct g_lock *lck, size_t i)
121 : {
122 17 : if (i >= lck->num_shared) {
123 0 : abort();
124 : }
125 17 : lck->num_shared -= 1;
126 17 : if (i < lck->num_shared) {
127 21 : memcpy(lck->shared + i*SERVER_ID_BUF_LENGTH,
128 4 : lck->shared + lck->num_shared*SERVER_ID_BUF_LENGTH,
129 : SERVER_ID_BUF_LENGTH);
130 : }
131 17 : }
132 :
133 1187434 : static NTSTATUS g_lock_store(
134 : struct db_record *rec,
135 : struct g_lock *lck,
136 : struct server_id *new_shared,
137 : const TDB_DATA *new_dbufs,
138 : size_t num_new_dbufs)
139 1187434 : {
140 2509 : uint8_t exclusive[SERVER_ID_BUF_LENGTH];
141 2509 : uint8_t seqnum_buf[sizeof(uint64_t)*2];
142 2509 : uint8_t sizebuf[sizeof(uint32_t)];
143 2509 : uint8_t new_shared_buf[SERVER_ID_BUF_LENGTH];
144 :
145 1187434 : struct TDB_DATA dbufs[6 + num_new_dbufs];
146 :
147 1187434 : dbufs[0] = (TDB_DATA) {
148 : .dptr = exclusive, .dsize = sizeof(exclusive),
149 : };
150 1187434 : dbufs[1] = (TDB_DATA) {
151 : .dptr = seqnum_buf, .dsize = sizeof(seqnum_buf),
152 : };
153 1187434 : dbufs[2] = (TDB_DATA) {
154 : .dptr = sizebuf, .dsize = sizeof(sizebuf),
155 : };
156 1187434 : dbufs[3] = (TDB_DATA) {
157 1187434 : .dptr = lck->shared,
158 1187434 : .dsize = lck->num_shared * SERVER_ID_BUF_LENGTH,
159 : };
160 1187434 : dbufs[4] = (TDB_DATA) { 0 };
161 1187434 : dbufs[5] = (TDB_DATA) {
162 1187434 : .dptr = lck->data, .dsize = lck->datalen,
163 : };
164 :
165 1187434 : if (num_new_dbufs != 0) {
166 1937 : memcpy(&dbufs[6],
167 : new_dbufs,
168 : num_new_dbufs * sizeof(TDB_DATA));
169 : }
170 :
171 1187434 : server_id_put(exclusive, lck->exclusive);
172 1187434 : SBVAL(seqnum_buf, 0, lck->unique_lock_epoch);
173 1187434 : SBVAL(seqnum_buf, 8, lck->unique_data_epoch);
174 :
175 1187434 : if (new_shared != NULL) {
176 18 : if (lck->num_shared >= UINT32_MAX) {
177 0 : return NT_STATUS_BUFFER_OVERFLOW;
178 : }
179 :
180 18 : server_id_put(new_shared_buf, *new_shared);
181 :
182 18 : dbufs[4] = (TDB_DATA) {
183 : .dptr = new_shared_buf,
184 : .dsize = sizeof(new_shared_buf),
185 : };
186 :
187 18 : lck->num_shared += 1;
188 : }
189 :
190 1187434 : SIVAL(sizebuf, 0, lck->num_shared);
191 :
192 1187434 : return dbwrap_record_storev(rec, dbufs, ARRAY_SIZE(dbufs), 0);
193 : }
194 :
195 354 : struct g_lock_ctx *g_lock_ctx_init_backend(
196 : TALLOC_CTX *mem_ctx,
197 : struct messaging_context *msg,
198 : struct db_context **backend)
199 : {
200 21 : struct g_lock_ctx *result;
201 :
202 354 : result = talloc_zero(mem_ctx, struct g_lock_ctx);
203 354 : if (result == NULL) {
204 0 : return NULL;
205 : }
206 354 : result->msg = msg;
207 354 : result->lock_order = DBWRAP_LOCK_ORDER_NONE;
208 :
209 354 : result->db = db_open_watched(result, backend, msg);
210 354 : if (result->db == NULL) {
211 0 : DBG_WARNING("db_open_watched failed\n");
212 0 : TALLOC_FREE(result);
213 0 : return NULL;
214 : }
215 333 : return result;
216 : }
217 :
218 195 : void g_lock_set_lock_order(struct g_lock_ctx *ctx,
219 : enum dbwrap_lock_order lock_order)
220 : {
221 195 : ctx->lock_order = lock_order;
222 195 : }
223 :
224 159 : struct g_lock_ctx *g_lock_ctx_init(TALLOC_CTX *mem_ctx,
225 : struct messaging_context *msg)
226 : {
227 159 : char *db_path = NULL;
228 159 : struct db_context *backend = NULL;
229 159 : struct g_lock_ctx *ctx = NULL;
230 :
231 159 : db_path = lock_path(mem_ctx, "g_lock.tdb");
232 159 : if (db_path == NULL) {
233 0 : return NULL;
234 : }
235 :
236 159 : backend = db_open(
237 : mem_ctx,
238 : db_path,
239 : 0,
240 : TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH|TDB_VOLATILE,
241 : O_RDWR|O_CREAT,
242 : 0600,
243 : DBWRAP_LOCK_ORDER_3,
244 : DBWRAP_FLAG_NONE);
245 159 : TALLOC_FREE(db_path);
246 159 : if (backend == NULL) {
247 0 : DBG_WARNING("Could not open g_lock.tdb\n");
248 0 : return NULL;
249 : }
250 :
251 159 : ctx = g_lock_ctx_init_backend(mem_ctx, msg, &backend);
252 159 : return ctx;
253 : }
254 :
255 318 : static void g_lock_cleanup_dead(
256 : struct g_lock *lck,
257 : struct server_id *dead_blocker)
258 : {
259 14 : bool exclusive_died;
260 14 : struct server_id_buf tmp;
261 :
262 318 : if (dead_blocker == NULL) {
263 315 : return;
264 : }
265 :
266 3 : exclusive_died = server_id_equal(dead_blocker, &lck->exclusive);
267 :
268 3 : if (exclusive_died) {
269 1 : DBG_DEBUG("Exclusive holder %s died\n",
270 : server_id_str_buf(lck->exclusive, &tmp));
271 1 : lck->exclusive.pid = 0;
272 : }
273 :
274 3 : if (lck->num_shared != 0) {
275 2 : bool shared_died;
276 2 : struct server_id shared;
277 :
278 2 : g_lock_get_shared(lck, 0, &shared);
279 2 : shared_died = server_id_equal(dead_blocker, &shared);
280 :
281 2 : if (shared_died) {
282 2 : DBG_DEBUG("Shared holder %s died\n",
283 : server_id_str_buf(shared, &tmp));
284 2 : g_lock_del_shared(lck, 0);
285 : }
286 : }
287 : }
288 :
289 301 : static ssize_t g_lock_find_shared(
290 : struct g_lock *lck,
291 : const struct server_id *self)
292 : {
293 11 : size_t i;
294 :
295 310 : for (i=0; i<lck->num_shared; i++) {
296 13 : struct server_id shared;
297 13 : bool same;
298 :
299 13 : g_lock_get_shared(lck, i, &shared);
300 :
301 13 : same = server_id_equal(self, &shared);
302 13 : if (same) {
303 4 : return i;
304 : }
305 : }
306 :
307 290 : return -1;
308 : }
309 :
310 317 : static void g_lock_cleanup_shared(struct g_lock *lck)
311 : {
312 27 : size_t i;
313 27 : struct server_id check;
314 27 : bool exists;
315 :
316 317 : if (lck->num_shared == 0) {
317 299 : return;
318 : }
319 :
320 : /*
321 : * Read locks can stay around forever if the process dies. Do
322 : * a heuristic check for process existence: Check one random
323 : * process for existence. Hopefully this will keep runaway
324 : * read locks under control.
325 : */
326 18 : i = generate_random() % lck->num_shared;
327 18 : g_lock_get_shared(lck, i, &check);
328 :
329 18 : exists = serverid_exists(&check);
330 18 : if (!exists) {
331 6 : struct server_id_buf tmp;
332 6 : DBG_DEBUG("Shared locker %s died -- removing\n",
333 : server_id_str_buf(check, &tmp));
334 6 : g_lock_del_shared(lck, i);
335 : }
336 : }
337 :
338 : struct g_lock_lock_cb_state {
339 : struct g_lock_ctx *ctx;
340 : struct db_record *rec;
341 : struct g_lock *lck;
342 : struct server_id *new_shared;
343 : g_lock_lock_cb_fn_t cb_fn;
344 : void *cb_private;
345 : TALLOC_CTX *update_mem_ctx;
346 : TDB_DATA updated_data;
347 : bool existed;
348 : bool modified;
349 : bool unlock;
350 : };
351 :
352 3255474 : NTSTATUS g_lock_lock_cb_dump(struct g_lock_lock_cb_state *cb_state,
353 : void (*fn)(struct server_id exclusive,
354 : size_t num_shared,
355 : const struct server_id *shared,
356 : const uint8_t *data,
357 : size_t datalen,
358 : void *private_data),
359 : void *private_data)
360 : {
361 3255474 : struct g_lock *lck = cb_state->lck;
362 :
363 : /* We allow a cn_fn only for G_LOCK_WRITE for now... */
364 3255474 : SMB_ASSERT(lck->num_shared == 0);
365 :
366 3255474 : fn(lck->exclusive,
367 : 0, /* num_shared */
368 : NULL, /* shared */
369 3255474 : lck->data,
370 : lck->datalen,
371 : private_data);
372 :
373 3255474 : return NT_STATUS_OK;
374 : }
375 :
376 756218 : NTSTATUS g_lock_lock_cb_writev(struct g_lock_lock_cb_state *cb_state,
377 : const TDB_DATA *dbufs,
378 : size_t num_dbufs)
379 : {
380 1915 : NTSTATUS status;
381 :
382 756218 : status = dbwrap_merge_dbufs(&cb_state->updated_data,
383 : cb_state->update_mem_ctx,
384 : dbufs, num_dbufs);
385 756218 : if (!NT_STATUS_IS_OK(status)) {
386 0 : return status;
387 : }
388 :
389 756218 : cb_state->modified = true;
390 756218 : cb_state->lck->data = cb_state->updated_data.dptr;
391 756218 : cb_state->lck->datalen = cb_state->updated_data.dsize;
392 :
393 756218 : return NT_STATUS_OK;
394 : }
395 :
396 457726 : void g_lock_lock_cb_unlock(struct g_lock_lock_cb_state *cb_state)
397 : {
398 457726 : cb_state->unlock = true;
399 457726 : }
400 :
401 : struct g_lock_lock_cb_watch_data_state {
402 : struct tevent_context *ev;
403 : struct g_lock_ctx *ctx;
404 : TDB_DATA key;
405 : struct server_id blocker;
406 : bool blockerdead;
407 : uint64_t unique_lock_epoch;
408 : uint64_t unique_data_epoch;
409 : uint64_t watch_instance;
410 : NTSTATUS status;
411 : };
412 :
413 : static void g_lock_lock_cb_watch_data_done(struct tevent_req *subreq);
414 :
415 499 : struct tevent_req *g_lock_lock_cb_watch_data_send(
416 : TALLOC_CTX *mem_ctx,
417 : struct tevent_context *ev,
418 : struct g_lock_lock_cb_state *cb_state,
419 : struct server_id blocker)
420 : {
421 499 : struct tevent_req *req = NULL;
422 499 : struct g_lock_lock_cb_watch_data_state *state = NULL;
423 499 : struct tevent_req *subreq = NULL;
424 499 : TDB_DATA key = dbwrap_record_get_key(cb_state->rec);
425 :
426 499 : req = tevent_req_create(
427 : mem_ctx, &state, struct g_lock_lock_cb_watch_data_state);
428 499 : if (req == NULL) {
429 0 : return NULL;
430 : }
431 499 : state->ev = ev;
432 499 : state->ctx = cb_state->ctx;
433 499 : state->blocker = blocker;
434 :
435 499 : state->key = tdb_data_talloc_copy(state, key);
436 499 : if (tevent_req_nomem(state->key.dptr, req)) {
437 0 : return tevent_req_post(req, ev);
438 : }
439 :
440 499 : state->unique_lock_epoch = cb_state->lck->unique_lock_epoch;
441 499 : state->unique_data_epoch = cb_state->lck->unique_data_epoch;
442 :
443 499 : DBG_DEBUG("state->unique_data_epoch=%"PRIu64"\n", state->unique_data_epoch);
444 :
445 499 : subreq = dbwrap_watched_watch_send(
446 499 : state, state->ev, cb_state->rec, 0, state->blocker);
447 499 : if (tevent_req_nomem(subreq, req)) {
448 0 : return tevent_req_post(req, ev);
449 : }
450 499 : tevent_req_set_callback(subreq, g_lock_lock_cb_watch_data_done, req);
451 :
452 499 : return req;
453 : }
454 :
455 713 : static void g_lock_lock_cb_watch_data_done_fn(
456 : struct db_record *rec,
457 : TDB_DATA value,
458 : void *private_data)
459 : {
460 713 : struct tevent_req *req = talloc_get_type_abort(
461 : private_data, struct tevent_req);
462 713 : struct g_lock_lock_cb_watch_data_state *state = tevent_req_data(
463 : req, struct g_lock_lock_cb_watch_data_state);
464 713 : struct tevent_req *subreq = NULL;
465 0 : struct g_lock lck;
466 0 : bool ok;
467 :
468 713 : ok = g_lock_parse(value.dptr, value.dsize, &lck);
469 713 : if (!ok) {
470 0 : dbwrap_watched_watch_remove_instance(rec, state->watch_instance);
471 0 : state->status = NT_STATUS_INTERNAL_DB_CORRUPTION;
472 0 : return;
473 : }
474 :
475 713 : if (lck.unique_data_epoch != state->unique_data_epoch) {
476 447 : dbwrap_watched_watch_remove_instance(rec, state->watch_instance);
477 447 : DBG_DEBUG("lck.unique_data_epoch=%"PRIu64", "
478 : "state->unique_data_epoch=%"PRIu64"\n",
479 : lck.unique_data_epoch,
480 : state->unique_data_epoch);
481 447 : state->status = NT_STATUS_OK;
482 447 : return;
483 : }
484 :
485 : /*
486 : * The lock epoch changed, so we better
487 : * remove ourself from the waiter list
488 : * (most likely the first position)
489 : * and re-add us at the end of the list.
490 : *
491 : * This gives other lock waiters a change
492 : * to make progress.
493 : *
494 : * Otherwise we'll keep our waiter instance alive,
495 : * keep waiting (most likely at first position).
496 : */
497 266 : if (lck.unique_lock_epoch != state->unique_lock_epoch) {
498 242 : dbwrap_watched_watch_remove_instance(rec, state->watch_instance);
499 242 : state->watch_instance = dbwrap_watched_watch_add_instance(rec);
500 242 : state->unique_lock_epoch = lck.unique_lock_epoch;
501 : }
502 :
503 266 : subreq = dbwrap_watched_watch_send(
504 : state, state->ev, rec, state->watch_instance, state->blocker);
505 266 : if (subreq == NULL) {
506 0 : dbwrap_watched_watch_remove_instance(rec, state->watch_instance);
507 0 : state->status = NT_STATUS_NO_MEMORY;
508 0 : return;
509 : }
510 266 : tevent_req_set_callback(subreq, g_lock_lock_cb_watch_data_done, req);
511 :
512 266 : state->status = NT_STATUS_EVENT_PENDING;
513 : }
514 :
515 713 : static void g_lock_lock_cb_watch_data_done(struct tevent_req *subreq)
516 : {
517 713 : struct tevent_req *req = tevent_req_callback_data(
518 : subreq, struct tevent_req);
519 713 : struct g_lock_lock_cb_watch_data_state *state = tevent_req_data(
520 : req, struct g_lock_lock_cb_watch_data_state);
521 0 : NTSTATUS status;
522 713 : uint64_t instance = 0;
523 :
524 713 : status = dbwrap_watched_watch_recv(
525 : subreq, &instance, &state->blockerdead, &state->blocker);
526 713 : TALLOC_FREE(subreq);
527 713 : if (tevent_req_nterror(req, status)) {
528 0 : DBG_DEBUG("dbwrap_watched_watch_recv returned %s\n",
529 : nt_errstr(status));
530 266 : return;
531 : }
532 :
533 713 : state->watch_instance = instance;
534 :
535 713 : status = dbwrap_do_locked(
536 713 : state->ctx->db, state->key, g_lock_lock_cb_watch_data_done_fn, req);
537 713 : if (tevent_req_nterror(req, status)) {
538 0 : DBG_DEBUG("dbwrap_do_locked returned %s\n", nt_errstr(status));
539 0 : return;
540 : }
541 713 : if (NT_STATUS_EQUAL(state->status, NT_STATUS_EVENT_PENDING)) {
542 266 : return;
543 : }
544 447 : if (tevent_req_nterror(req, state->status)) {
545 0 : return;
546 : }
547 447 : tevent_req_done(req);
548 : }
549 :
550 447 : NTSTATUS g_lock_lock_cb_watch_data_recv(
551 : struct tevent_req *req,
552 : bool *blockerdead,
553 : struct server_id *blocker)
554 : {
555 447 : struct g_lock_lock_cb_watch_data_state *state = tevent_req_data(
556 : req, struct g_lock_lock_cb_watch_data_state);
557 0 : NTSTATUS status;
558 :
559 447 : if (tevent_req_is_nterror(req, &status)) {
560 0 : return status;
561 : }
562 447 : if (blockerdead != NULL) {
563 447 : *blockerdead = state->blockerdead;
564 : }
565 447 : if (blocker != NULL) {
566 447 : *blocker = state->blocker;
567 : }
568 :
569 447 : return NT_STATUS_OK;
570 : }
571 :
572 2542 : void g_lock_lock_cb_wake_watchers(struct g_lock_lock_cb_state *cb_state)
573 : {
574 2542 : struct g_lock *lck = cb_state->lck;
575 :
576 2542 : lck->unique_data_epoch = generate_unique_u64(lck->unique_data_epoch);
577 2542 : cb_state->modified = true;
578 2542 : }
579 :
580 948869 : static NTSTATUS g_lock_lock_cb_run_and_store(struct g_lock_lock_cb_state *cb_state)
581 : {
582 948869 : struct g_lock *lck = cb_state->lck;
583 948869 : NTSTATUS success_status = NT_STATUS_OK;
584 2314 : NTSTATUS status;
585 :
586 948869 : if (cb_state->cb_fn != NULL) {
587 :
588 937014 : SMB_ASSERT(lck->num_shared == 0);
589 937014 : SMB_ASSERT(cb_state->new_shared == NULL);
590 :
591 937014 : if (cb_state->ctx->lock_order != DBWRAP_LOCK_ORDER_NONE) {
592 937014 : const char *name = dbwrap_name(cb_state->ctx->db);
593 937014 : dbwrap_lock_order_lock(name, cb_state->ctx->lock_order);
594 : }
595 :
596 937014 : cb_state->ctx->busy = true;
597 937014 : cb_state->cb_fn(cb_state, cb_state->cb_private);
598 937014 : cb_state->ctx->busy = false;
599 :
600 937014 : if (cb_state->ctx->lock_order != DBWRAP_LOCK_ORDER_NONE) {
601 937014 : const char *name = dbwrap_name(cb_state->ctx->db);
602 937014 : dbwrap_lock_order_unlock(name, cb_state->ctx->lock_order);
603 : }
604 : }
605 :
606 948869 : if (cb_state->unlock) {
607 : /*
608 : * Unlocked should wake up watchers.
609 : *
610 : * We no longer need the lock, so
611 : * force a wakeup of the next watchers,
612 : * even if we don't do any update.
613 : */
614 457726 : dbwrap_watched_watch_reset_alerting(cb_state->rec);
615 457726 : dbwrap_watched_watch_force_alerting(cb_state->rec);
616 457726 : if (!cb_state->modified) {
617 : /*
618 : * The record was not changed at
619 : * all, so we can also avoid
620 : * storing the lck.unique_lock_epoch
621 : * change
622 : */
623 13003 : return NT_STATUS_WAS_UNLOCKED;
624 : }
625 444723 : lck->exclusive = (struct server_id) { .pid = 0 };
626 444723 : cb_state->new_shared = NULL;
627 :
628 444723 : if (lck->datalen == 0) {
629 243491 : if (!cb_state->existed) {
630 0 : return NT_STATUS_WAS_UNLOCKED;
631 : }
632 :
633 243491 : status = dbwrap_record_delete(cb_state->rec);
634 243491 : if (!NT_STATUS_IS_OK(status)) {
635 0 : DBG_WARNING("dbwrap_record_delete() failed: %s\n",
636 : nt_errstr(status));
637 0 : return status;
638 : }
639 243491 : return NT_STATUS_WAS_UNLOCKED;
640 : }
641 :
642 200428 : success_status = NT_STATUS_WAS_UNLOCKED;
643 : }
644 :
645 692375 : status = g_lock_store(cb_state->rec,
646 : cb_state->lck,
647 : cb_state->new_shared,
648 : NULL, 0);
649 692375 : if (!NT_STATUS_IS_OK(status)) {
650 0 : DBG_WARNING("g_lock_store() failed: %s\n",
651 : nt_errstr(status));
652 0 : return status;
653 : }
654 :
655 692375 : return success_status;
656 : }
657 :
658 : struct g_lock_lock_state {
659 : struct tevent_context *ev;
660 : struct g_lock_ctx *ctx;
661 : TDB_DATA key;
662 : enum g_lock_type type;
663 : bool retry;
664 : g_lock_lock_cb_fn_t cb_fn;
665 : void *cb_private;
666 : };
667 :
668 : struct g_lock_lock_fn_state {
669 : struct g_lock_lock_state *req_state;
670 : struct server_id *dead_blocker;
671 :
672 : struct tevent_req *watch_req;
673 : uint64_t watch_instance;
674 : NTSTATUS status;
675 : };
676 :
677 : static int g_lock_lock_state_destructor(struct g_lock_lock_state *s);
678 :
679 318 : static NTSTATUS g_lock_trylock(
680 : struct db_record *rec,
681 : struct g_lock_lock_fn_state *state,
682 : TDB_DATA data,
683 : struct server_id *blocker)
684 : {
685 318 : struct g_lock_lock_state *req_state = state->req_state;
686 318 : struct server_id self = messaging_server_id(req_state->ctx->msg);
687 318 : enum g_lock_type type = req_state->type;
688 318 : bool retry = req_state->retry;
689 318 : struct g_lock lck = { .exclusive.pid = 0 };
690 636 : struct g_lock_lock_cb_state cb_state = {
691 318 : .ctx = req_state->ctx,
692 : .rec = rec,
693 : .lck = &lck,
694 318 : .cb_fn = req_state->cb_fn,
695 318 : .cb_private = req_state->cb_private,
696 318 : .existed = data.dsize != 0,
697 318 : .update_mem_ctx = talloc_tos(),
698 : };
699 14 : struct server_id_buf tmp;
700 14 : NTSTATUS status;
701 14 : bool ok;
702 :
703 318 : ok = g_lock_parse(data.dptr, data.dsize, &lck);
704 318 : if (!ok) {
705 0 : dbwrap_watched_watch_remove_instance(rec, state->watch_instance);
706 0 : DBG_DEBUG("g_lock_parse failed\n");
707 0 : return NT_STATUS_INTERNAL_DB_CORRUPTION;
708 : }
709 :
710 318 : g_lock_cleanup_dead(&lck, state->dead_blocker);
711 :
712 318 : lck.unique_lock_epoch = generate_unique_u64(lck.unique_lock_epoch);
713 :
714 318 : if (lck.exclusive.pid != 0) {
715 21 : bool self_exclusive = server_id_equal(&self, &lck.exclusive);
716 :
717 21 : if (!self_exclusive) {
718 18 : bool exists = serverid_exists(&lck.exclusive);
719 18 : if (!exists) {
720 0 : lck.exclusive = (struct server_id) { .pid=0 };
721 0 : goto noexclusive;
722 : }
723 :
724 18 : DBG_DEBUG("%s has an exclusive lock\n",
725 : server_id_str_buf(lck.exclusive, &tmp));
726 :
727 18 : if (type == G_LOCK_DOWNGRADE) {
728 0 : struct server_id_buf tmp2;
729 :
730 0 : dbwrap_watched_watch_remove_instance(rec,
731 : state->watch_instance);
732 :
733 0 : DBG_DEBUG("%s: Trying to downgrade %s\n",
734 : server_id_str_buf(self, &tmp),
735 : server_id_str_buf(
736 : lck.exclusive, &tmp2));
737 0 : return NT_STATUS_NOT_LOCKED;
738 : }
739 :
740 18 : if (type == G_LOCK_UPGRADE) {
741 1 : ssize_t shared_idx;
742 :
743 1 : dbwrap_watched_watch_remove_instance(rec,
744 : state->watch_instance);
745 :
746 1 : shared_idx = g_lock_find_shared(&lck, &self);
747 :
748 1 : if (shared_idx == -1) {
749 0 : DBG_DEBUG("Trying to upgrade %s "
750 : "without "
751 : "existing shared lock\n",
752 : server_id_str_buf(
753 : self, &tmp));
754 0 : return NT_STATUS_NOT_LOCKED;
755 : }
756 :
757 : /*
758 : * We're trying to upgrade, and the
759 : * exclusive lock is taken by someone
760 : * else. This means that someone else
761 : * is waiting for us to give up our
762 : * shared lock. If we now also wait
763 : * for someone to give their shared
764 : * lock, we will deadlock.
765 : */
766 :
767 1 : DBG_DEBUG("Trying to upgrade %s while "
768 : "someone else is also "
769 : "trying to upgrade\n",
770 : server_id_str_buf(self, &tmp));
771 1 : return NT_STATUS_POSSIBLE_DEADLOCK;
772 : }
773 :
774 17 : DBG_DEBUG("Waiting for lck.exclusive=%s\n",
775 : server_id_str_buf(lck.exclusive, &tmp));
776 :
777 : /*
778 : * We will return NT_STATUS_LOCK_NOT_GRANTED
779 : * and need to monitor the record.
780 : *
781 : * If we don't have a watcher instance yet,
782 : * we should add one.
783 : */
784 17 : if (state->watch_instance == 0) {
785 15 : state->watch_instance =
786 15 : dbwrap_watched_watch_add_instance(rec);
787 : }
788 :
789 17 : *blocker = lck.exclusive;
790 17 : return NT_STATUS_LOCK_NOT_GRANTED;
791 : }
792 :
793 3 : if (type == G_LOCK_DOWNGRADE) {
794 0 : DBG_DEBUG("Downgrading %s from WRITE to READ\n",
795 : server_id_str_buf(self, &tmp));
796 :
797 0 : lck.exclusive = (struct server_id) { .pid = 0 };
798 0 : goto do_shared;
799 : }
800 :
801 3 : if (!retry) {
802 1 : dbwrap_watched_watch_remove_instance(rec,
803 : state->watch_instance);
804 :
805 1 : DBG_DEBUG("%s already locked by self\n",
806 : server_id_str_buf(self, &tmp));
807 1 : return NT_STATUS_WAS_LOCKED;
808 : }
809 :
810 2 : g_lock_cleanup_shared(&lck);
811 :
812 2 : if (lck.num_shared != 0) {
813 0 : g_lock_get_shared(&lck, 0, blocker);
814 :
815 0 : DBG_DEBUG("Continue waiting for shared lock %s\n",
816 : server_id_str_buf(*blocker, &tmp));
817 :
818 : /*
819 : * We will return NT_STATUS_LOCK_NOT_GRANTED
820 : * and need to monitor the record.
821 : *
822 : * If we don't have a watcher instance yet,
823 : * we should add one.
824 : */
825 0 : if (state->watch_instance == 0) {
826 0 : state->watch_instance =
827 0 : dbwrap_watched_watch_add_instance(rec);
828 : }
829 :
830 0 : return NT_STATUS_LOCK_NOT_GRANTED;
831 : }
832 :
833 : /*
834 : * Retry after a conflicting lock was released..
835 : * All pending readers are gone so we got the lock...
836 : */
837 2 : goto got_lock;
838 : }
839 :
840 297 : noexclusive:
841 :
842 297 : if (type == G_LOCK_UPGRADE) {
843 3 : ssize_t shared_idx = g_lock_find_shared(&lck, &self);
844 :
845 3 : if (shared_idx == -1) {
846 0 : dbwrap_watched_watch_remove_instance(rec,
847 : state->watch_instance);
848 :
849 0 : DBG_DEBUG("Trying to upgrade %s without "
850 : "existing shared lock\n",
851 : server_id_str_buf(self, &tmp));
852 0 : return NT_STATUS_NOT_LOCKED;
853 : }
854 :
855 3 : g_lock_del_shared(&lck, shared_idx);
856 3 : type = G_LOCK_WRITE;
857 : }
858 :
859 297 : if (type == G_LOCK_WRITE) {
860 297 : ssize_t shared_idx = g_lock_find_shared(&lck, &self);
861 :
862 297 : if (shared_idx != -1) {
863 0 : dbwrap_watched_watch_remove_instance(rec,
864 : state->watch_instance);
865 0 : DBG_DEBUG("Trying to writelock existing shared %s\n",
866 : server_id_str_buf(self, &tmp));
867 0 : return NT_STATUS_WAS_LOCKED;
868 : }
869 :
870 297 : lck.exclusive = self;
871 :
872 297 : g_lock_cleanup_shared(&lck);
873 :
874 297 : if (lck.num_shared == 0) {
875 : /*
876 : * If we store ourself as exclusive writer,
877 : * without any pending readers ...
878 : */
879 292 : goto got_lock;
880 : }
881 :
882 5 : if (state->watch_instance == 0) {
883 : /*
884 : * Here we have lck.num_shared != 0.
885 : *
886 : * We will return NT_STATUS_LOCK_NOT_GRANTED
887 : * below.
888 : *
889 : * And don't have a watcher instance yet!
890 : *
891 : * We add it here before g_lock_store()
892 : * in order to trigger just one
893 : * low level dbwrap_do_locked() call.
894 : */
895 5 : state->watch_instance =
896 5 : dbwrap_watched_watch_add_instance(rec);
897 : }
898 :
899 5 : status = g_lock_store(rec, &lck, NULL, NULL, 0);
900 5 : if (!NT_STATUS_IS_OK(status)) {
901 0 : DBG_DEBUG("g_lock_store() failed: %s\n",
902 : nt_errstr(status));
903 0 : return status;
904 : }
905 :
906 5 : talloc_set_destructor(
907 : req_state, g_lock_lock_state_destructor);
908 :
909 5 : g_lock_get_shared(&lck, 0, blocker);
910 :
911 5 : DBG_DEBUG("Waiting for %zu shared locks, "
912 : "picking blocker %s\n",
913 : lck.num_shared,
914 : server_id_str_buf(*blocker, &tmp));
915 :
916 5 : return NT_STATUS_LOCK_NOT_GRANTED;
917 : }
918 :
919 0 : do_shared:
920 :
921 0 : g_lock_cleanup_shared(&lck);
922 0 : cb_state.new_shared = &self;
923 0 : goto got_lock;
924 :
925 294 : got_lock:
926 : /*
927 : * We got the lock we asked for, so we no
928 : * longer need to monitor the record.
929 : */
930 294 : dbwrap_watched_watch_remove_instance(rec, state->watch_instance);
931 :
932 294 : status = g_lock_lock_cb_run_and_store(&cb_state);
933 294 : if (!NT_STATUS_IS_OK(status) &&
934 7 : !NT_STATUS_EQUAL(status, NT_STATUS_WAS_UNLOCKED))
935 : {
936 0 : DBG_WARNING("g_lock_lock_cb_run_and_store() failed: %s\n",
937 : nt_errstr(status));
938 0 : return status;
939 : }
940 :
941 294 : talloc_set_destructor(req_state, NULL);
942 294 : return status;
943 : }
944 :
945 318 : static void g_lock_lock_fn(
946 : struct db_record *rec,
947 : TDB_DATA value,
948 : void *private_data)
949 : {
950 318 : struct g_lock_lock_fn_state *state = private_data;
951 318 : struct server_id blocker = {0};
952 :
953 : /*
954 : * We're trying to get a lock and if we are
955 : * successful in doing that, we should not
956 : * wakeup any other waiters, all they would
957 : * find is that we're holding a lock they
958 : * are conflicting with.
959 : */
960 318 : dbwrap_watched_watch_skip_alerting(rec);
961 :
962 318 : state->status = g_lock_trylock(rec, state, value, &blocker);
963 318 : if (!NT_STATUS_IS_OK(state->status)) {
964 31 : DBG_DEBUG("g_lock_trylock returned %s\n",
965 : nt_errstr(state->status));
966 : }
967 318 : if (!NT_STATUS_EQUAL(state->status, NT_STATUS_LOCK_NOT_GRANTED)) {
968 296 : return;
969 : }
970 :
971 44 : state->watch_req = dbwrap_watched_watch_send(
972 22 : state->req_state, state->req_state->ev, rec, state->watch_instance, blocker);
973 22 : if (state->watch_req == NULL) {
974 0 : state->status = NT_STATUS_NO_MEMORY;
975 : }
976 : }
977 :
978 2 : static int g_lock_lock_state_destructor(struct g_lock_lock_state *s)
979 : {
980 2 : NTSTATUS status = g_lock_unlock(s->ctx, s->key);
981 2 : if (!NT_STATUS_IS_OK(status)) {
982 0 : DBG_DEBUG("g_lock_unlock failed: %s\n", nt_errstr(status));
983 : }
984 2 : return 0;
985 : }
986 :
987 : static void g_lock_lock_retry(struct tevent_req *subreq);
988 :
989 301 : struct tevent_req *g_lock_lock_send(TALLOC_CTX *mem_ctx,
990 : struct tevent_context *ev,
991 : struct g_lock_ctx *ctx,
992 : TDB_DATA key,
993 : enum g_lock_type type,
994 : g_lock_lock_cb_fn_t cb_fn,
995 : void *cb_private)
996 : {
997 11 : struct tevent_req *req;
998 11 : struct g_lock_lock_state *state;
999 11 : struct g_lock_lock_fn_state fn_state;
1000 11 : NTSTATUS status;
1001 11 : bool ok;
1002 :
1003 301 : SMB_ASSERT(!ctx->busy);
1004 :
1005 301 : req = tevent_req_create(mem_ctx, &state, struct g_lock_lock_state);
1006 301 : if (req == NULL) {
1007 0 : return NULL;
1008 : }
1009 301 : state->ev = ev;
1010 301 : state->ctx = ctx;
1011 301 : state->key = key;
1012 301 : state->type = type;
1013 301 : state->cb_fn = cb_fn;
1014 301 : state->cb_private = cb_private;
1015 :
1016 301 : fn_state = (struct g_lock_lock_fn_state) {
1017 : .req_state = state,
1018 : };
1019 :
1020 : /*
1021 : * We allow a cn_fn only for G_LOCK_WRITE for now.
1022 : *
1023 : * It's all we currently need and it makes a few things
1024 : * easier to implement.
1025 : */
1026 301 : if (unlikely(cb_fn != NULL && type != G_LOCK_WRITE)) {
1027 0 : tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER_6);
1028 0 : return tevent_req_post(req, ev);
1029 : }
1030 :
1031 301 : status = dbwrap_do_locked(ctx->db, key, g_lock_lock_fn, &fn_state);
1032 301 : if (tevent_req_nterror(req, status)) {
1033 0 : DBG_DEBUG("dbwrap_do_locked failed: %s\n",
1034 : nt_errstr(status));
1035 0 : return tevent_req_post(req, ev);
1036 : }
1037 :
1038 301 : if (NT_STATUS_IS_OK(fn_state.status)) {
1039 279 : tevent_req_done(req);
1040 279 : return tevent_req_post(req, ev);
1041 : }
1042 22 : if (!NT_STATUS_EQUAL(fn_state.status, NT_STATUS_LOCK_NOT_GRANTED)) {
1043 2 : tevent_req_nterror(req, fn_state.status);
1044 2 : return tevent_req_post(req, ev);
1045 : }
1046 :
1047 20 : if (tevent_req_nomem(fn_state.watch_req, req)) {
1048 0 : return tevent_req_post(req, ev);
1049 : }
1050 :
1051 56 : ok = tevent_req_set_endtime(
1052 : fn_state.watch_req,
1053 20 : state->ev,
1054 20 : timeval_current_ofs(5 + generate_random() % 5, 0));
1055 20 : if (!ok) {
1056 0 : tevent_req_oom(req);
1057 0 : return tevent_req_post(req, ev);
1058 : }
1059 20 : tevent_req_set_callback(fn_state.watch_req, g_lock_lock_retry, req);
1060 :
1061 20 : return req;
1062 : }
1063 :
1064 17 : static void g_lock_lock_retry(struct tevent_req *subreq)
1065 : {
1066 17 : struct tevent_req *req = tevent_req_callback_data(
1067 : subreq, struct tevent_req);
1068 17 : struct g_lock_lock_state *state = tevent_req_data(
1069 : req, struct g_lock_lock_state);
1070 3 : struct g_lock_lock_fn_state fn_state;
1071 17 : struct server_id blocker = { .pid = 0 };
1072 17 : bool blockerdead = false;
1073 3 : NTSTATUS status;
1074 17 : uint64_t instance = 0;
1075 :
1076 17 : status = dbwrap_watched_watch_recv(subreq, &instance, &blockerdead, &blocker);
1077 17 : DBG_DEBUG("watch_recv returned %s\n", nt_errstr(status));
1078 17 : TALLOC_FREE(subreq);
1079 :
1080 17 : if (!NT_STATUS_IS_OK(status) &&
1081 0 : !NT_STATUS_EQUAL(status, NT_STATUS_IO_TIMEOUT)) {
1082 0 : tevent_req_nterror(req, status);
1083 0 : return;
1084 : }
1085 :
1086 17 : state->retry = true;
1087 :
1088 20 : fn_state = (struct g_lock_lock_fn_state) {
1089 : .req_state = state,
1090 17 : .dead_blocker = blockerdead ? &blocker : NULL,
1091 : .watch_instance = instance,
1092 : };
1093 :
1094 17 : status = dbwrap_do_locked(state->ctx->db, state->key,
1095 : g_lock_lock_fn, &fn_state);
1096 17 : if (tevent_req_nterror(req, status)) {
1097 0 : DBG_DEBUG("dbwrap_do_locked failed: %s\n",
1098 : nt_errstr(status));
1099 0 : return;
1100 : }
1101 :
1102 17 : if (NT_STATUS_IS_OK(fn_state.status)) {
1103 8 : tevent_req_done(req);
1104 8 : return;
1105 : }
1106 9 : if (!NT_STATUS_EQUAL(fn_state.status, NT_STATUS_LOCK_NOT_GRANTED)) {
1107 7 : tevent_req_nterror(req, fn_state.status);
1108 7 : return;
1109 : }
1110 :
1111 2 : if (tevent_req_nomem(fn_state.watch_req, req)) {
1112 0 : return;
1113 : }
1114 :
1115 2 : if (!tevent_req_set_endtime(
1116 : fn_state.watch_req, state->ev,
1117 2 : timeval_current_ofs(5 + generate_random() % 5, 0))) {
1118 0 : return;
1119 : }
1120 2 : tevent_req_set_callback(fn_state.watch_req, g_lock_lock_retry, req);
1121 : }
1122 :
1123 300 : NTSTATUS g_lock_lock_recv(struct tevent_req *req)
1124 : {
1125 300 : struct g_lock_lock_state *state = tevent_req_data(
1126 : req, struct g_lock_lock_state);
1127 300 : struct g_lock_ctx *ctx = state->ctx;
1128 10 : NTSTATUS status;
1129 :
1130 300 : if (tevent_req_is_nterror(req, &status)) {
1131 13 : if (NT_STATUS_EQUAL(status, NT_STATUS_WAS_UNLOCKED)) {
1132 7 : return NT_STATUS_OK;
1133 : }
1134 6 : return status;
1135 : }
1136 :
1137 287 : if ((ctx->lock_order != DBWRAP_LOCK_ORDER_NONE) &&
1138 6 : ((state->type == G_LOCK_READ) ||
1139 6 : (state->type == G_LOCK_WRITE))) {
1140 6 : const char *name = dbwrap_name(ctx->db);
1141 6 : dbwrap_lock_order_lock(name, ctx->lock_order);
1142 : }
1143 :
1144 287 : return NT_STATUS_OK;
1145 : }
1146 :
1147 : struct g_lock_lock_simple_state {
1148 : struct g_lock_ctx *ctx;
1149 : struct server_id me;
1150 : enum g_lock_type type;
1151 : NTSTATUS status;
1152 : g_lock_lock_cb_fn_t cb_fn;
1153 : void *cb_private;
1154 : };
1155 :
1156 948593 : static void g_lock_lock_simple_fn(
1157 : struct db_record *rec,
1158 : TDB_DATA value,
1159 : void *private_data)
1160 : {
1161 948593 : struct g_lock_lock_simple_state *state = private_data;
1162 2315 : struct server_id_buf buf;
1163 948593 : struct g_lock lck = { .exclusive.pid = 0 };
1164 1897186 : struct g_lock_lock_cb_state cb_state = {
1165 948593 : .ctx = state->ctx,
1166 : .rec = rec,
1167 : .lck = &lck,
1168 948593 : .cb_fn = state->cb_fn,
1169 948593 : .cb_private = state->cb_private,
1170 948593 : .existed = value.dsize != 0,
1171 948593 : .update_mem_ctx = talloc_tos(),
1172 : };
1173 2315 : bool ok;
1174 :
1175 948593 : ok = g_lock_parse(value.dptr, value.dsize, &lck);
1176 948593 : if (!ok) {
1177 0 : DBG_DEBUG("g_lock_parse failed\n");
1178 0 : state->status = NT_STATUS_INTERNAL_DB_CORRUPTION;
1179 0 : return;
1180 : }
1181 :
1182 948593 : if (lck.exclusive.pid != 0) {
1183 16 : DBG_DEBUG("locked by %s\n",
1184 : server_id_str_buf(lck.exclusive, &buf));
1185 16 : goto not_granted;
1186 : }
1187 :
1188 948577 : if (state->type == G_LOCK_WRITE) {
1189 948559 : if (lck.num_shared != 0) {
1190 2 : DBG_DEBUG("num_shared=%zu\n", lck.num_shared);
1191 2 : goto not_granted;
1192 : }
1193 948557 : lck.exclusive = state->me;
1194 18 : } else if (state->type == G_LOCK_READ) {
1195 18 : g_lock_cleanup_shared(&lck);
1196 18 : cb_state.new_shared = &state->me;
1197 : } else {
1198 0 : smb_panic(__location__);
1199 : }
1200 :
1201 948575 : lck.unique_lock_epoch = generate_unique_u64(lck.unique_lock_epoch);
1202 :
1203 : /*
1204 : * We are going to store us as owner,
1205 : * so we got what we were waiting for.
1206 : *
1207 : * So we no longer need to monitor the
1208 : * record.
1209 : */
1210 948575 : dbwrap_watched_watch_skip_alerting(rec);
1211 :
1212 948575 : state->status = g_lock_lock_cb_run_and_store(&cb_state);
1213 948575 : if (!NT_STATUS_IS_OK(state->status) &&
1214 456250 : !NT_STATUS_EQUAL(state->status, NT_STATUS_WAS_UNLOCKED))
1215 : {
1216 0 : DBG_WARNING("g_lock_lock_cb_run_and_store() failed: %s\n",
1217 : nt_errstr(state->status));
1218 0 : return;
1219 : }
1220 :
1221 946265 : return;
1222 :
1223 18 : not_granted:
1224 18 : state->status = NT_STATUS_LOCK_NOT_GRANTED;
1225 : }
1226 :
1227 948596 : NTSTATUS g_lock_lock(struct g_lock_ctx *ctx, TDB_DATA key,
1228 : enum g_lock_type type, struct timeval timeout,
1229 : g_lock_lock_cb_fn_t cb_fn,
1230 : void *cb_private)
1231 : {
1232 2318 : TALLOC_CTX *frame;
1233 2318 : struct tevent_context *ev;
1234 2318 : struct tevent_req *req;
1235 2318 : struct timeval end;
1236 2318 : NTSTATUS status;
1237 :
1238 948596 : SMB_ASSERT(!ctx->busy);
1239 :
1240 : /*
1241 : * We allow a cn_fn only for G_LOCK_WRITE for now.
1242 : *
1243 : * It's all we currently need and it makes a few things
1244 : * easier to implement.
1245 : */
1246 948596 : if (unlikely(cb_fn != NULL && type != G_LOCK_WRITE)) {
1247 0 : return NT_STATUS_INVALID_PARAMETER_5;
1248 : }
1249 :
1250 948596 : if ((type == G_LOCK_READ) || (type == G_LOCK_WRITE)) {
1251 : /*
1252 : * This is an abstraction violation: Normally we do
1253 : * the sync wrappers around async functions with full
1254 : * nested event contexts. However, this is used in
1255 : * very hot code paths, so avoid the event context
1256 : * creation for the good path where there's no lock
1257 : * contention. My benchmark gave a factor of 2
1258 : * improvement for lock/unlock.
1259 : */
1260 1897186 : struct g_lock_lock_simple_state state = {
1261 : .ctx = ctx,
1262 948593 : .me = messaging_server_id(ctx->msg),
1263 : .type = type,
1264 : .cb_fn = cb_fn,
1265 : .cb_private = cb_private,
1266 : };
1267 948593 : status = dbwrap_do_locked(
1268 : ctx->db, key, g_lock_lock_simple_fn, &state);
1269 948593 : if (!NT_STATUS_IS_OK(status)) {
1270 0 : DBG_DEBUG("dbwrap_do_locked() failed: %s\n",
1271 : nt_errstr(status));
1272 948575 : return status;
1273 : }
1274 :
1275 948593 : DBG_DEBUG("status=%s, state.status=%s\n",
1276 : nt_errstr(status),
1277 : nt_errstr(state.status));
1278 :
1279 948593 : if (NT_STATUS_IS_OK(state.status)) {
1280 490856 : if (ctx->lock_order != DBWRAP_LOCK_ORDER_NONE) {
1281 490827 : const char *name = dbwrap_name(ctx->db);
1282 490827 : dbwrap_lock_order_lock(name, ctx->lock_order);
1283 : }
1284 490856 : return NT_STATUS_OK;
1285 : }
1286 457737 : if (NT_STATUS_EQUAL(state.status, NT_STATUS_WAS_UNLOCKED)) {
1287 : /* without dbwrap_lock_order_lock() */
1288 457719 : return NT_STATUS_OK;
1289 : }
1290 18 : if (!NT_STATUS_EQUAL(
1291 : state.status, NT_STATUS_LOCK_NOT_GRANTED)) {
1292 0 : return state.status;
1293 : }
1294 :
1295 18 : if (timeval_is_zero(&timeout)) {
1296 0 : return NT_STATUS_LOCK_NOT_GRANTED;
1297 : }
1298 :
1299 : /*
1300 : * Fall back to the full g_lock_trylock logic,
1301 : * g_lock_lock_simple_fn() called above only covers
1302 : * the uncontended path.
1303 : */
1304 : }
1305 :
1306 21 : frame = talloc_stackframe();
1307 21 : status = NT_STATUS_NO_MEMORY;
1308 :
1309 21 : ev = samba_tevent_context_init(frame);
1310 21 : if (ev == NULL) {
1311 0 : goto fail;
1312 : }
1313 21 : req = g_lock_lock_send(frame, ev, ctx, key, type, cb_fn, cb_private);
1314 21 : if (req == NULL) {
1315 0 : goto fail;
1316 : }
1317 21 : end = timeval_current_ofs(timeout.tv_sec, timeout.tv_usec);
1318 21 : if (!tevent_req_set_endtime(req, ev, end)) {
1319 0 : goto fail;
1320 : }
1321 21 : if (!tevent_req_poll_ntstatus(req, ev, &status)) {
1322 0 : goto fail;
1323 : }
1324 21 : status = g_lock_lock_recv(req);
1325 21 : fail:
1326 21 : TALLOC_FREE(frame);
1327 21 : return status;
1328 : }
1329 :
1330 : struct g_lock_unlock_state {
1331 : struct server_id self;
1332 : NTSTATUS status;
1333 : };
1334 :
1335 491129 : static void g_lock_unlock_fn(
1336 : struct db_record *rec,
1337 : TDB_DATA value,
1338 : void *private_data)
1339 : {
1340 491129 : struct g_lock_unlock_state *state = private_data;
1341 831 : struct server_id_buf tmp1, tmp2;
1342 831 : struct g_lock lck;
1343 831 : size_t i;
1344 831 : bool ok, exclusive;
1345 :
1346 491129 : ok = g_lock_parse(value.dptr, value.dsize, &lck);
1347 491129 : if (!ok) {
1348 0 : DBG_DEBUG("g_lock_parse() failed\n");
1349 0 : state->status = NT_STATUS_INTERNAL_DB_CORRUPTION;
1350 0 : return;
1351 : }
1352 :
1353 491129 : exclusive = server_id_equal(&state->self, &lck.exclusive);
1354 :
1355 491974 : for (i=0; i<lck.num_shared; i++) {
1356 20 : struct server_id shared;
1357 20 : g_lock_get_shared(&lck, i, &shared);
1358 20 : if (server_id_equal(&state->self, &shared)) {
1359 0 : break;
1360 : }
1361 : }
1362 :
1363 491129 : if (i < lck.num_shared) {
1364 6 : if (exclusive) {
1365 0 : DBG_DEBUG("%s both exclusive and shared (%zu)\n",
1366 : server_id_str_buf(state->self, &tmp1),
1367 : i);
1368 0 : state->status = NT_STATUS_INTERNAL_DB_CORRUPTION;
1369 0 : return;
1370 : }
1371 6 : g_lock_del_shared(&lck, i);
1372 : } else {
1373 491123 : if (!exclusive) {
1374 1 : DBG_DEBUG("Lock not found, self=%s, lck.exclusive=%s, "
1375 : "num_shared=%zu\n",
1376 : server_id_str_buf(state->self, &tmp1),
1377 : server_id_str_buf(lck.exclusive, &tmp2),
1378 : lck.num_shared);
1379 1 : state->status = NT_STATUS_NOT_FOUND;
1380 1 : return;
1381 : }
1382 491122 : lck.exclusive = (struct server_id) { .pid = 0 };
1383 : }
1384 :
1385 491128 : if ((lck.exclusive.pid == 0) &&
1386 491128 : (lck.num_shared == 0) &&
1387 491121 : (lck.datalen == 0)) {
1388 170682 : state->status = dbwrap_record_delete(rec);
1389 170682 : return;
1390 : }
1391 :
1392 320446 : if (!exclusive && lck.exclusive.pid != 0) {
1393 : /*
1394 : * We only had a read lock and there's
1395 : * someone waiting for an exclusive lock.
1396 : *
1397 : * Don't alert the exclusive lock waiter
1398 : * if there are still other read lock holders.
1399 : */
1400 0 : g_lock_cleanup_shared(&lck);
1401 0 : if (lck.num_shared != 0) {
1402 0 : dbwrap_watched_watch_skip_alerting(rec);
1403 : }
1404 : }
1405 :
1406 320446 : lck.unique_lock_epoch = generate_unique_u64(lck.unique_lock_epoch);
1407 :
1408 320446 : state->status = g_lock_store(rec, &lck, NULL, NULL, 0);
1409 : }
1410 :
1411 491129 : NTSTATUS g_lock_unlock(struct g_lock_ctx *ctx, TDB_DATA key)
1412 : {
1413 491129 : struct g_lock_unlock_state state = {
1414 491129 : .self = messaging_server_id(ctx->msg),
1415 : };
1416 831 : NTSTATUS status;
1417 :
1418 491129 : SMB_ASSERT(!ctx->busy);
1419 :
1420 491129 : status = dbwrap_do_locked(ctx->db, key, g_lock_unlock_fn, &state);
1421 491129 : if (!NT_STATUS_IS_OK(status)) {
1422 0 : DBG_WARNING("dbwrap_do_locked failed: %s\n",
1423 : nt_errstr(status));
1424 0 : return status;
1425 : }
1426 491129 : if (!NT_STATUS_IS_OK(state.status)) {
1427 1 : DBG_WARNING("g_lock_unlock_fn failed: %s\n",
1428 : nt_errstr(state.status));
1429 1 : return state.status;
1430 : }
1431 :
1432 491128 : if (ctx->lock_order != DBWRAP_LOCK_ORDER_NONE) {
1433 490833 : const char *name = dbwrap_name(ctx->db);
1434 490833 : dbwrap_lock_order_unlock(name, ctx->lock_order);
1435 : }
1436 :
1437 491128 : return NT_STATUS_OK;
1438 : }
1439 :
1440 : struct g_lock_writev_data_state {
1441 : TDB_DATA key;
1442 : struct server_id self;
1443 : const TDB_DATA *dbufs;
1444 : size_t num_dbufs;
1445 : NTSTATUS status;
1446 : };
1447 :
1448 172281 : static void g_lock_writev_data_fn(
1449 : struct db_record *rec,
1450 : TDB_DATA value,
1451 : void *private_data)
1452 : {
1453 172281 : struct g_lock_writev_data_state *state = private_data;
1454 356 : struct g_lock lck;
1455 356 : bool exclusive;
1456 356 : bool ok;
1457 :
1458 : /*
1459 : * We're holding an exclusive write lock.
1460 : *
1461 : * Now we're updating the content of the record.
1462 : *
1463 : * We should not wakeup any other waiters, all they
1464 : * would find is that we're still holding a lock they
1465 : * are conflicting with.
1466 : */
1467 172281 : dbwrap_watched_watch_skip_alerting(rec);
1468 :
1469 172281 : ok = g_lock_parse(value.dptr, value.dsize, &lck);
1470 172281 : if (!ok) {
1471 0 : DBG_DEBUG("g_lock_parse for %s failed\n",
1472 : tdb_data_dbg(state->key));
1473 0 : state->status = NT_STATUS_INTERNAL_DB_CORRUPTION;
1474 0 : return;
1475 : }
1476 :
1477 172281 : exclusive = server_id_equal(&state->self, &lck.exclusive);
1478 :
1479 : /*
1480 : * Make sure we're really exclusive. We are marked as
1481 : * exclusive when we are waiting for an exclusive lock
1482 : */
1483 172281 : exclusive &= (lck.num_shared == 0);
1484 :
1485 172281 : if (!exclusive) {
1486 1 : struct server_id_buf buf1, buf2;
1487 1 : DBG_DEBUG("Not locked by us: self=%s, lck.exclusive=%s, "
1488 : "lck.num_shared=%zu\n",
1489 : server_id_str_buf(state->self, &buf1),
1490 : server_id_str_buf(lck.exclusive, &buf2),
1491 : lck.num_shared);
1492 1 : state->status = NT_STATUS_NOT_LOCKED;
1493 1 : return;
1494 : }
1495 :
1496 172280 : lck.unique_data_epoch = generate_unique_u64(lck.unique_data_epoch);
1497 172280 : lck.data = NULL;
1498 172280 : lck.datalen = 0;
1499 172280 : state->status = g_lock_store(
1500 : rec, &lck, NULL, state->dbufs, state->num_dbufs);
1501 : }
1502 :
1503 172281 : NTSTATUS g_lock_writev_data(
1504 : struct g_lock_ctx *ctx,
1505 : TDB_DATA key,
1506 : const TDB_DATA *dbufs,
1507 : size_t num_dbufs)
1508 : {
1509 344562 : struct g_lock_writev_data_state state = {
1510 : .key = key,
1511 172281 : .self = messaging_server_id(ctx->msg),
1512 : .dbufs = dbufs,
1513 : .num_dbufs = num_dbufs,
1514 : };
1515 356 : NTSTATUS status;
1516 :
1517 172281 : SMB_ASSERT(!ctx->busy);
1518 :
1519 172281 : status = dbwrap_do_locked(
1520 : ctx->db, key, g_lock_writev_data_fn, &state);
1521 172281 : if (!NT_STATUS_IS_OK(status)) {
1522 0 : DBG_WARNING("dbwrap_do_locked failed: %s\n",
1523 : nt_errstr(status));
1524 0 : return status;
1525 : }
1526 172281 : if (!NT_STATUS_IS_OK(state.status)) {
1527 1 : DBG_WARNING("g_lock_writev_data_fn failed: %s\n",
1528 : nt_errstr(state.status));
1529 1 : return state.status;
1530 : }
1531 :
1532 172280 : return NT_STATUS_OK;
1533 : }
1534 :
1535 4 : NTSTATUS g_lock_write_data(struct g_lock_ctx *ctx, TDB_DATA key,
1536 : const uint8_t *buf, size_t buflen)
1537 : {
1538 4 : TDB_DATA dbuf = {
1539 : .dptr = discard_const_p(uint8_t, buf),
1540 : .dsize = buflen,
1541 : };
1542 4 : return g_lock_writev_data(ctx, key, &dbuf, 1);
1543 : }
1544 :
1545 : struct g_lock_locks_state {
1546 : int (*fn)(TDB_DATA key, void *private_data);
1547 : void *private_data;
1548 : };
1549 :
1550 18777 : static int g_lock_locks_fn(struct db_record *rec, void *priv)
1551 : {
1552 0 : TDB_DATA key;
1553 18777 : struct g_lock_locks_state *state = (struct g_lock_locks_state *)priv;
1554 :
1555 18777 : key = dbwrap_record_get_key(rec);
1556 18777 : return state->fn(key, state->private_data);
1557 : }
1558 :
1559 6333 : int g_lock_locks(struct g_lock_ctx *ctx,
1560 : int (*fn)(TDB_DATA key, void *private_data),
1561 : void *private_data)
1562 : {
1563 0 : struct g_lock_locks_state state;
1564 0 : NTSTATUS status;
1565 0 : int count;
1566 :
1567 6333 : SMB_ASSERT(!ctx->busy);
1568 :
1569 6333 : state.fn = fn;
1570 6333 : state.private_data = private_data;
1571 :
1572 6333 : status = dbwrap_traverse_read(ctx->db, g_lock_locks_fn, &state, &count);
1573 6333 : if (!NT_STATUS_IS_OK(status)) {
1574 0 : return -1;
1575 : }
1576 6333 : return count;
1577 : }
1578 :
1579 : struct g_lock_dump_state {
1580 : TALLOC_CTX *mem_ctx;
1581 : TDB_DATA key;
1582 : void (*fn)(struct server_id exclusive,
1583 : size_t num_shared,
1584 : const struct server_id *shared,
1585 : const uint8_t *data,
1586 : size_t datalen,
1587 : void *private_data);
1588 : void *private_data;
1589 : NTSTATUS status;
1590 : enum dbwrap_req_state req_state;
1591 : };
1592 :
1593 262826 : static void g_lock_dump_fn(TDB_DATA key, TDB_DATA data,
1594 : void *private_data)
1595 : {
1596 262826 : struct g_lock_dump_state *state = private_data;
1597 262826 : struct g_lock lck = (struct g_lock) { .exclusive.pid = 0 };
1598 262826 : struct server_id *shared = NULL;
1599 1377 : size_t i;
1600 1377 : bool ok;
1601 :
1602 262826 : ok = g_lock_parse(data.dptr, data.dsize, &lck);
1603 262826 : if (!ok) {
1604 0 : DBG_DEBUG("g_lock_parse failed for %s\n",
1605 : tdb_data_dbg(state->key));
1606 0 : state->status = NT_STATUS_INTERNAL_DB_CORRUPTION;
1607 0 : return;
1608 : }
1609 :
1610 262826 : if (lck.num_shared > 0) {
1611 7 : shared = talloc_array(
1612 : state->mem_ctx, struct server_id, lck.num_shared);
1613 7 : if (shared == NULL) {
1614 0 : DBG_DEBUG("talloc failed\n");
1615 0 : state->status = NT_STATUS_NO_MEMORY;
1616 0 : return;
1617 : }
1618 : }
1619 :
1620 262844 : for (i=0; i<lck.num_shared; i++) {
1621 18 : g_lock_get_shared(&lck, i, &shared[i]);
1622 : }
1623 :
1624 262826 : state->fn(lck.exclusive,
1625 : lck.num_shared,
1626 : shared,
1627 262826 : lck.data,
1628 : lck.datalen,
1629 : state->private_data);
1630 :
1631 262826 : TALLOC_FREE(shared);
1632 :
1633 262826 : state->status = NT_STATUS_OK;
1634 : }
1635 :
1636 1087775 : NTSTATUS g_lock_dump(struct g_lock_ctx *ctx, TDB_DATA key,
1637 : void (*fn)(struct server_id exclusive,
1638 : size_t num_shared,
1639 : const struct server_id *shared,
1640 : const uint8_t *data,
1641 : size_t datalen,
1642 : void *private_data),
1643 : void *private_data)
1644 : {
1645 1087775 : struct g_lock_dump_state state = {
1646 : .mem_ctx = ctx, .key = key,
1647 : .fn = fn, .private_data = private_data
1648 : };
1649 1812 : NTSTATUS status;
1650 :
1651 1087775 : SMB_ASSERT(!ctx->busy);
1652 :
1653 1087775 : status = dbwrap_parse_record(ctx->db, key, g_lock_dump_fn, &state);
1654 1087775 : if (!NT_STATUS_IS_OK(status)) {
1655 824949 : DBG_DEBUG("dbwrap_parse_record returned %s\n",
1656 : nt_errstr(status));
1657 824949 : return status;
1658 : }
1659 262826 : if (!NT_STATUS_IS_OK(state.status)) {
1660 0 : DBG_DEBUG("g_lock_dump_fn returned %s\n",
1661 : nt_errstr(state.status));
1662 0 : return state.status;
1663 : }
1664 262826 : return NT_STATUS_OK;
1665 : }
1666 :
1667 : static void g_lock_dump_done(struct tevent_req *subreq);
1668 :
1669 0 : struct tevent_req *g_lock_dump_send(
1670 : TALLOC_CTX *mem_ctx,
1671 : struct tevent_context *ev,
1672 : struct g_lock_ctx *ctx,
1673 : TDB_DATA key,
1674 : void (*fn)(struct server_id exclusive,
1675 : size_t num_shared,
1676 : const struct server_id *shared,
1677 : const uint8_t *data,
1678 : size_t datalen,
1679 : void *private_data),
1680 : void *private_data)
1681 : {
1682 0 : struct tevent_req *req = NULL, *subreq = NULL;
1683 0 : struct g_lock_dump_state *state = NULL;
1684 :
1685 0 : SMB_ASSERT(!ctx->busy);
1686 :
1687 0 : req = tevent_req_create(mem_ctx, &state, struct g_lock_dump_state);
1688 0 : if (req == NULL) {
1689 0 : return NULL;
1690 : }
1691 0 : state->mem_ctx = state;
1692 0 : state->key = key;
1693 0 : state->fn = fn;
1694 0 : state->private_data = private_data;
1695 :
1696 0 : SMB_ASSERT(!ctx->busy);
1697 :
1698 0 : subreq = dbwrap_parse_record_send(
1699 : state,
1700 : ev,
1701 : ctx->db,
1702 : key,
1703 : g_lock_dump_fn,
1704 : state,
1705 0 : &state->req_state);
1706 0 : if (tevent_req_nomem(subreq, req)) {
1707 0 : return tevent_req_post(req, ev);
1708 : }
1709 0 : tevent_req_set_callback(subreq, g_lock_dump_done, req);
1710 0 : return req;
1711 : }
1712 :
1713 0 : static void g_lock_dump_done(struct tevent_req *subreq)
1714 : {
1715 0 : struct tevent_req *req = tevent_req_callback_data(
1716 : subreq, struct tevent_req);
1717 0 : struct g_lock_dump_state *state = tevent_req_data(
1718 : req, struct g_lock_dump_state);
1719 0 : NTSTATUS status;
1720 :
1721 0 : status = dbwrap_parse_record_recv(subreq);
1722 0 : TALLOC_FREE(subreq);
1723 0 : if (tevent_req_nterror(req, status) ||
1724 0 : tevent_req_nterror(req, state->status)) {
1725 0 : return;
1726 : }
1727 0 : tevent_req_done(req);
1728 : }
1729 :
1730 0 : NTSTATUS g_lock_dump_recv(struct tevent_req *req)
1731 : {
1732 0 : return tevent_req_simple_recv_ntstatus(req);
1733 : }
1734 :
1735 193231 : int g_lock_seqnum(struct g_lock_ctx *ctx)
1736 : {
1737 193231 : return dbwrap_get_seqnum(ctx->db);
1738 : }
1739 :
1740 : struct g_lock_watch_data_state {
1741 : struct tevent_context *ev;
1742 : struct g_lock_ctx *ctx;
1743 : TDB_DATA key;
1744 : struct server_id blocker;
1745 : bool blockerdead;
1746 : uint64_t unique_lock_epoch;
1747 : uint64_t unique_data_epoch;
1748 : uint64_t watch_instance;
1749 : NTSTATUS status;
1750 : };
1751 :
1752 : static void g_lock_watch_data_done(struct tevent_req *subreq);
1753 :
1754 653 : static void g_lock_watch_data_send_fn(
1755 : struct db_record *rec,
1756 : TDB_DATA value,
1757 : void *private_data)
1758 : {
1759 653 : struct tevent_req *req = talloc_get_type_abort(
1760 : private_data, struct tevent_req);
1761 653 : struct g_lock_watch_data_state *state = tevent_req_data(
1762 : req, struct g_lock_watch_data_state);
1763 653 : struct tevent_req *subreq = NULL;
1764 3 : struct g_lock lck;
1765 3 : bool ok;
1766 :
1767 653 : ok = g_lock_parse(value.dptr, value.dsize, &lck);
1768 653 : if (!ok) {
1769 0 : state->status = NT_STATUS_INTERNAL_DB_CORRUPTION;
1770 0 : return;
1771 : }
1772 653 : state->unique_lock_epoch = lck.unique_lock_epoch;
1773 653 : state->unique_data_epoch = lck.unique_data_epoch;
1774 :
1775 653 : DBG_DEBUG("state->unique_data_epoch=%"PRIu64"\n", state->unique_data_epoch);
1776 :
1777 653 : subreq = dbwrap_watched_watch_send(
1778 : state, state->ev, rec, 0, state->blocker);
1779 653 : if (subreq == NULL) {
1780 0 : state->status = NT_STATUS_NO_MEMORY;
1781 0 : return;
1782 : }
1783 653 : tevent_req_set_callback(subreq, g_lock_watch_data_done, req);
1784 :
1785 653 : state->status = NT_STATUS_EVENT_PENDING;
1786 : }
1787 :
1788 653 : struct tevent_req *g_lock_watch_data_send(
1789 : TALLOC_CTX *mem_ctx,
1790 : struct tevent_context *ev,
1791 : struct g_lock_ctx *ctx,
1792 : TDB_DATA key,
1793 : struct server_id blocker)
1794 : {
1795 653 : struct tevent_req *req = NULL;
1796 653 : struct g_lock_watch_data_state *state = NULL;
1797 3 : NTSTATUS status;
1798 :
1799 653 : SMB_ASSERT(!ctx->busy);
1800 :
1801 653 : req = tevent_req_create(
1802 : mem_ctx, &state, struct g_lock_watch_data_state);
1803 653 : if (req == NULL) {
1804 0 : return NULL;
1805 : }
1806 653 : state->ev = ev;
1807 653 : state->ctx = ctx;
1808 653 : state->blocker = blocker;
1809 :
1810 653 : state->key = tdb_data_talloc_copy(state, key);
1811 653 : if (tevent_req_nomem(state->key.dptr, req)) {
1812 0 : return tevent_req_post(req, ev);
1813 : }
1814 :
1815 653 : status = dbwrap_do_locked(
1816 : ctx->db, key, g_lock_watch_data_send_fn, req);
1817 653 : if (tevent_req_nterror(req, status)) {
1818 0 : DBG_DEBUG("dbwrap_do_locked returned %s\n", nt_errstr(status));
1819 0 : return tevent_req_post(req, ev);
1820 : }
1821 :
1822 653 : if (NT_STATUS_EQUAL(state->status, NT_STATUS_EVENT_PENDING)) {
1823 650 : return req;
1824 : }
1825 0 : if (tevent_req_nterror(req, state->status)) {
1826 0 : return tevent_req_post(req, ev);
1827 : }
1828 0 : tevent_req_done(req);
1829 0 : return tevent_req_post(req, ev);
1830 : }
1831 :
1832 1003 : static void g_lock_watch_data_done_fn(
1833 : struct db_record *rec,
1834 : TDB_DATA value,
1835 : void *private_data)
1836 : {
1837 1003 : struct tevent_req *req = talloc_get_type_abort(
1838 : private_data, struct tevent_req);
1839 1003 : struct g_lock_watch_data_state *state = tevent_req_data(
1840 : req, struct g_lock_watch_data_state);
1841 1003 : struct tevent_req *subreq = NULL;
1842 3 : struct g_lock lck;
1843 3 : bool ok;
1844 :
1845 1003 : ok = g_lock_parse(value.dptr, value.dsize, &lck);
1846 1003 : if (!ok) {
1847 0 : dbwrap_watched_watch_remove_instance(rec, state->watch_instance);
1848 0 : state->status = NT_STATUS_INTERNAL_DB_CORRUPTION;
1849 0 : return;
1850 : }
1851 :
1852 1003 : if (lck.unique_data_epoch != state->unique_data_epoch) {
1853 87 : dbwrap_watched_watch_remove_instance(rec, state->watch_instance);
1854 87 : DBG_DEBUG("lck.unique_data_epoch=%"PRIu64", "
1855 : "state->unique_data_epoch=%"PRIu64"\n",
1856 : lck.unique_data_epoch,
1857 : state->unique_data_epoch);
1858 87 : state->status = NT_STATUS_OK;
1859 87 : return;
1860 : }
1861 :
1862 : /*
1863 : * The lock epoch changed, so we better
1864 : * remove ourself from the waiter list
1865 : * (most likely the first position)
1866 : * and re-add us at the end of the list.
1867 : *
1868 : * This gives other lock waiters a change
1869 : * to make progress.
1870 : *
1871 : * Otherwise we'll keep our waiter instance alive,
1872 : * keep waiting (most likely at first position).
1873 : */
1874 916 : if (lck.unique_lock_epoch != state->unique_lock_epoch) {
1875 830 : dbwrap_watched_watch_remove_instance(rec, state->watch_instance);
1876 830 : state->watch_instance = dbwrap_watched_watch_add_instance(rec);
1877 830 : state->unique_lock_epoch = lck.unique_lock_epoch;
1878 : }
1879 :
1880 916 : subreq = dbwrap_watched_watch_send(
1881 : state, state->ev, rec, state->watch_instance, state->blocker);
1882 916 : if (subreq == NULL) {
1883 0 : dbwrap_watched_watch_remove_instance(rec, state->watch_instance);
1884 0 : state->status = NT_STATUS_NO_MEMORY;
1885 0 : return;
1886 : }
1887 916 : tevent_req_set_callback(subreq, g_lock_watch_data_done, req);
1888 :
1889 916 : state->status = NT_STATUS_EVENT_PENDING;
1890 : }
1891 :
1892 1003 : static void g_lock_watch_data_done(struct tevent_req *subreq)
1893 : {
1894 1003 : struct tevent_req *req = tevent_req_callback_data(
1895 : subreq, struct tevent_req);
1896 1003 : struct g_lock_watch_data_state *state = tevent_req_data(
1897 : req, struct g_lock_watch_data_state);
1898 3 : NTSTATUS status;
1899 1003 : uint64_t instance = 0;
1900 :
1901 1003 : status = dbwrap_watched_watch_recv(
1902 : subreq, &instance, &state->blockerdead, &state->blocker);
1903 1003 : TALLOC_FREE(subreq);
1904 1003 : if (tevent_req_nterror(req, status)) {
1905 0 : DBG_DEBUG("dbwrap_watched_watch_recv returned %s\n",
1906 : nt_errstr(status));
1907 916 : return;
1908 : }
1909 :
1910 1003 : state->watch_instance = instance;
1911 :
1912 1003 : status = dbwrap_do_locked(
1913 1003 : state->ctx->db, state->key, g_lock_watch_data_done_fn, req);
1914 1003 : if (tevent_req_nterror(req, status)) {
1915 0 : DBG_DEBUG("dbwrap_do_locked returned %s\n", nt_errstr(status));
1916 0 : return;
1917 : }
1918 1003 : if (NT_STATUS_EQUAL(state->status, NT_STATUS_EVENT_PENDING)) {
1919 914 : return;
1920 : }
1921 87 : if (tevent_req_nterror(req, state->status)) {
1922 0 : return;
1923 : }
1924 87 : tevent_req_done(req);
1925 : }
1926 :
1927 86 : NTSTATUS g_lock_watch_data_recv(
1928 : struct tevent_req *req,
1929 : bool *blockerdead,
1930 : struct server_id *blocker)
1931 : {
1932 86 : struct g_lock_watch_data_state *state = tevent_req_data(
1933 : req, struct g_lock_watch_data_state);
1934 0 : NTSTATUS status;
1935 :
1936 86 : if (tevent_req_is_nterror(req, &status)) {
1937 0 : return status;
1938 : }
1939 86 : if (blockerdead != NULL) {
1940 86 : *blockerdead = state->blockerdead;
1941 : }
1942 86 : if (blocker != NULL) {
1943 86 : *blocker = state->blocker;
1944 : }
1945 :
1946 86 : return NT_STATUS_OK;
1947 : }
1948 :
1949 2328 : static void g_lock_wake_watchers_fn(
1950 : struct db_record *rec,
1951 : TDB_DATA value,
1952 : void *private_data)
1953 : {
1954 2328 : struct g_lock lck = { .exclusive.pid = 0 };
1955 10 : NTSTATUS status;
1956 10 : bool ok;
1957 :
1958 2328 : ok = g_lock_parse(value.dptr, value.dsize, &lck);
1959 2328 : if (!ok) {
1960 0 : DBG_WARNING("g_lock_parse failed\n");
1961 0 : return;
1962 : }
1963 :
1964 2328 : lck.unique_data_epoch = generate_unique_u64(lck.unique_data_epoch);
1965 :
1966 2328 : status = g_lock_store(rec, &lck, NULL, NULL, 0);
1967 2328 : if (!NT_STATUS_IS_OK(status)) {
1968 0 : DBG_WARNING("g_lock_store failed: %s\n", nt_errstr(status));
1969 0 : return;
1970 : }
1971 : }
1972 :
1973 2328 : void g_lock_wake_watchers(struct g_lock_ctx *ctx, TDB_DATA key)
1974 : {
1975 10 : NTSTATUS status;
1976 :
1977 2328 : SMB_ASSERT(!ctx->busy);
1978 :
1979 2328 : status = dbwrap_do_locked(ctx->db, key, g_lock_wake_watchers_fn, NULL);
1980 2328 : if (!NT_STATUS_IS_OK(status)) {
1981 0 : DBG_DEBUG("dbwrap_do_locked returned %s\n",
1982 : nt_errstr(status));
1983 : }
1984 2328 : }
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