source: trunk/server/lib/tdb/common/open.c@ 866

Last change on this file since 866 was 866, checked in by Silvan Scherrer, 12 years ago

SambaServer: better version for creating AL files
File size: 18.8 KB
Line 
1 /*
2 Unix SMB/CIFS implementation.
3
4 trivial database library
5
6 Copyright (C) Andrew Tridgell 1999-2005
7 Copyright (C) Paul `Rusty' Russell 2000
8 Copyright (C) Jeremy Allison 2000-2003
9
10 ** NOTE! The following LGPL license applies to the tdb
11 ** library. This does NOT imply that all of Samba is released
12 ** under the LGPL
13
14 This library is free software; you can redistribute it and/or
15 modify it under the terms of the GNU Lesser General Public
16 License as published by the Free Software Foundation; either
17 version 3 of the License, or (at your option) any later version.
18
19 This library is distributed in the hope that it will be useful,
20 but WITHOUT ANY WARRANTY; without even the implied warranty of
21 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 Lesser General Public License for more details.
23
24 You should have received a copy of the GNU Lesser General Public
25 License along with this library; if not, see <http://www.gnu.org/licenses/>.
26*/
27
28#include "tdb_private.h"
29
30/* all contexts, to ensure no double-opens (fcntl locks don't nest!) */
31static struct tdb_context *tdbs = NULL;
32
33/* We use two hashes to double-check they're using the right hash function. */
34void tdb_header_hash(struct tdb_context *tdb,
35 uint32_t *magic1_hash, uint32_t *magic2_hash)
36{
37 TDB_DATA hash_key;
38 uint32_t tdb_magic = TDB_MAGIC;
39
40 hash_key.dptr = discard_const_p(unsigned char, TDB_MAGIC_FOOD);
41 hash_key.dsize = sizeof(TDB_MAGIC_FOOD);
42 *magic1_hash = tdb->hash_fn(&hash_key);
43
44 hash_key.dptr = (unsigned char *)CONVERT(tdb_magic);
45 hash_key.dsize = sizeof(tdb_magic);
46 *magic2_hash = tdb->hash_fn(&hash_key);
47
48 /* Make sure at least one hash is non-zero! */
49 if (*magic1_hash == 0 && *magic2_hash == 0)
50 *magic1_hash = 1;
51}
52
53/* initialise a new database with a specified hash size */
54static int tdb_new_database(struct tdb_context *tdb, int hash_size)
55{
56 struct tdb_header *newdb;
57 size_t size;
58 int ret = -1;
59
60 /* We make it up in memory, then write it out if not internal */
61 size = sizeof(struct tdb_header) + (hash_size+1)*sizeof(tdb_off_t);
62 if (!(newdb = (struct tdb_header *)calloc(size, 1))) {
63 tdb->ecode = TDB_ERR_OOM;
64 return -1;
65 }
66
67 /* Fill in the header */
68 newdb->version = TDB_VERSION;
69 newdb->hash_size = hash_size;
70
71 tdb_header_hash(tdb, &newdb->magic1_hash, &newdb->magic2_hash);
72
73 /* Make sure older tdbs (which don't check the magic hash fields)
74 * will refuse to open this TDB. */
75 if (tdb->flags & TDB_INCOMPATIBLE_HASH)
76 newdb->rwlocks = TDB_HASH_RWLOCK_MAGIC;
77
78 if (tdb->flags & TDB_INTERNAL) {
79 tdb->map_size = size;
80 tdb->map_ptr = (char *)newdb;
81 memcpy(&tdb->header, newdb, sizeof(tdb->header));
82 /* Convert the `ondisk' version if asked. */
83 CONVERT(*newdb);
84 return 0;
85 }
86 if (lseek(tdb->fd, 0, SEEK_SET) == -1)
87 goto fail;
88
89 if (ftruncate(tdb->fd, 0) == -1)
90 goto fail;
91
92 /* This creates an endian-converted header, as if read from disk */
93 CONVERT(*newdb);
94 memcpy(&tdb->header, newdb, sizeof(tdb->header));
95 /* Don't endian-convert the magic food! */
96 memcpy(newdb->magic_food, TDB_MAGIC_FOOD, strlen(TDB_MAGIC_FOOD)+1);
97 /* we still have "ret == -1" here */
98 if (tdb_write_all(tdb->fd, newdb, size))
99 ret = 0;
100
101 fail:
102 SAFE_FREE(newdb);
103 return ret;
104}
105
106
107
108static int tdb_already_open(dev_t device,
109 ino_t ino)
110{
111 struct tdb_context *i;
112
113 for (i = tdbs; i; i = i->next) {
114 if (i->device == device && i->inode == ino) {
115 return 1;
116 }
117 }
118
119 return 0;
120}
121
122/* open the database, creating it if necessary
123
124 The open_flags and mode are passed straight to the open call on the
125 database file. A flags value of O_WRONLY is invalid. The hash size
126 is advisory, use zero for a default value.
127
128 Return is NULL on error, in which case errno is also set. Don't
129 try to call tdb_error or tdb_errname, just do strerror(errno).
130
131 @param name may be NULL for internal databases. */
132_PUBLIC_ struct tdb_context *tdb_open(const char *name, int hash_size, int tdb_flags,
133 int open_flags, mode_t mode)
134{
135 return tdb_open_ex(name, hash_size, tdb_flags, open_flags, mode, NULL, NULL);
136}
137
138/* a default logging function */
139static void null_log_fn(struct tdb_context *tdb, enum tdb_debug_level level, const char *fmt, ...) PRINTF_ATTRIBUTE(3, 4);
140static void null_log_fn(struct tdb_context *tdb, enum tdb_debug_level level, const char *fmt, ...)
141{
142}
143
144static bool check_header_hash(struct tdb_context *tdb,
145 bool default_hash, uint32_t *m1, uint32_t *m2)
146{
147 tdb_header_hash(tdb, m1, m2);
148 if (tdb->header.magic1_hash == *m1 &&
149 tdb->header.magic2_hash == *m2) {
150 return true;
151 }
152
153 /* If they explicitly set a hash, always respect it. */
154 if (!default_hash)
155 return false;
156
157 /* Otherwise, try the other inbuilt hash. */
158 if (tdb->hash_fn == tdb_old_hash)
159 tdb->hash_fn = tdb_jenkins_hash;
160 else
161 tdb->hash_fn = tdb_old_hash;
162 return check_header_hash(tdb, false, m1, m2);
163}
164
165_PUBLIC_ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
166 int open_flags, mode_t mode,
167 const struct tdb_logging_context *log_ctx,
168 tdb_hash_func hash_fn)
169{
170 struct tdb_context *tdb;
171 struct stat st;
172 int rev = 0, locked = 0;
173 unsigned char *vp;
174 uint32_t vertest;
175 unsigned v;
176 const char *hash_alg;
177 uint32_t magic1, magic2;
178
179 if (!(tdb = (struct tdb_context *)calloc(1, sizeof *tdb))) {
180 /* Can't log this */
181 errno = ENOMEM;
182 goto fail;
183 }
184 tdb_io_init(tdb);
185 tdb->fd = -1;
186#ifdef TDB_TRACE
187 tdb->tracefd = -1;
188#endif
189 tdb->name = NULL;
190 tdb->map_ptr = NULL;
191 tdb->flags = tdb_flags;
192 tdb->open_flags = open_flags;
193 if (log_ctx) {
194 tdb->log = *log_ctx;
195 } else {
196 tdb->log.log_fn = null_log_fn;
197 tdb->log.log_private = NULL;
198 }
199
200 if (name == NULL && (tdb_flags & TDB_INTERNAL)) {
201 name = "__TDB_INTERNAL__";
202 }
203
204 if (name == NULL) {
205 tdb->name = discard_const_p(char, "__NULL__");
206 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: called with name == NULL\n"));
207 tdb->name = NULL;
208 errno = EINVAL;
209 goto fail;
210 }
211
212 /* now make a copy of the name, as the caller memory might went away */
213 if (!(tdb->name = (char *)strdup(name))) {
214 /*
215 * set the name as the given string, so that tdb_name() will
216 * work in case of an error.
217 */
218 tdb->name = discard_const_p(char, name);
219 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: can't strdup(%s)\n",
220 name));
221 tdb->name = NULL;
222 errno = ENOMEM;
223 goto fail;
224 }
225
226 if (hash_fn) {
227 tdb->hash_fn = hash_fn;
228 hash_alg = "the user defined";
229 } else {
230 /* This controls what we use when creating a tdb. */
231 if (tdb->flags & TDB_INCOMPATIBLE_HASH) {
232 tdb->hash_fn = tdb_jenkins_hash;
233 } else {
234 tdb->hash_fn = tdb_old_hash;
235 }
236 hash_alg = "either default";
237 }
238
239 /* cache the page size */
240 tdb->page_size = getpagesize();
241 if (tdb->page_size <= 0) {
242 tdb->page_size = 0x2000;
243 }
244
245 tdb->max_dead_records = (tdb_flags & TDB_VOLATILE) ? 5 : 0;
246
247 if ((open_flags & O_ACCMODE) == O_WRONLY) {
248 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: can't open tdb %s write-only\n",
249 name));
250 errno = EINVAL;
251 goto fail;
252 }
253
254 if (hash_size == 0)
255 hash_size = DEFAULT_HASH_SIZE;
256 if ((open_flags & O_ACCMODE) == O_RDONLY) {
257 tdb->read_only = 1;
258 /* read only databases don't do locking or clear if first */
259 tdb->flags |= TDB_NOLOCK;
260 tdb->flags &= ~TDB_CLEAR_IF_FIRST;
261 }
262
263 if ((tdb->flags & TDB_ALLOW_NESTING) &&
264 (tdb->flags & TDB_DISALLOW_NESTING)) {
265 tdb->ecode = TDB_ERR_NESTING;
266 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
267 "allow_nesting and disallow_nesting are not allowed together!"));
268 errno = EINVAL;
269 goto fail;
270 }
271
272 if (getenv("TDB_NO_FSYNC")) {
273 tdb->flags |= TDB_NOSYNC;
274 }
275
276 /*
277 * TDB_ALLOW_NESTING is the default behavior.
278 * Note: this may change in future versions!
279 */
280 if (!(tdb->flags & TDB_DISALLOW_NESTING)) {
281 tdb->flags |= TDB_ALLOW_NESTING;
282 }
283
284 /* internal databases don't mmap or lock, and start off cleared */
285 if (tdb->flags & TDB_INTERNAL) {
286 tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);
287 tdb->flags &= ~TDB_CLEAR_IF_FIRST;
288 if (tdb_new_database(tdb, hash_size) != 0) {
289 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: tdb_new_database failed!"));
290 goto fail;
291 }
292 goto internal;
293 }
294
295 if ((tdb->fd = open(name, open_flags, mode)) == -1) {
296 TDB_LOG((tdb, TDB_DEBUG_WARNING, "tdb_open_ex: could not open file %s: %s\n",
297 name, strerror(errno)));
298 goto fail; /* errno set by open(2) */
299 }
300
301 /* on exec, don't inherit the fd */
302 v = fcntl(tdb->fd, F_GETFD, 0);
303 fcntl(tdb->fd, F_SETFD, v | FD_CLOEXEC);
304
305#ifdef __OS2__
306 if (os2_crtActiveLock(tdb, name, "tdb_open_ex") != 0)
307 goto fail;
308#endif
309
310 /* ensure there is only one process initialising at once */
311 if (tdb_nest_lock(tdb, OPEN_LOCK, F_WRLCK, TDB_LOCK_WAIT) == -1) {
312 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to get open lock on %s: %s\n",
313 name, strerror(errno)));
314 goto fail; /* errno set by tdb_brlock */
315 }
316
317 /* we need to zero database if we are the only one with it open */
318 if ((tdb_flags & TDB_CLEAR_IF_FIRST) &&
319 (!tdb->read_only) &&
320 (locked = (tdb_nest_lock(tdb, ACTIVE_LOCK, F_WRLCK, TDB_LOCK_NOWAIT|TDB_LOCK_PROBE) == 0))) {
321 int ret;
322 ret = tdb_brlock(tdb, F_WRLCK, FREELIST_TOP, 0,
323 TDB_LOCK_WAIT);
324 if (ret == -1) {
325 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
326 "tdb_brlock failed for %s: %s\n",
327 name, strerror(errno)));
328 goto fail;
329 }
330 ret = tdb_new_database(tdb, hash_size);
331 if (ret == -1) {
332 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
333 "tdb_new_database failed for %s: %s\n",
334 name, strerror(errno)));
335 tdb_unlockall(tdb);
336 goto fail;
337 }
338 ret = tdb_brunlock(tdb, F_WRLCK, FREELIST_TOP, 0);
339 if (ret == -1) {
340 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
341 "tdb_unlockall failed for %s: %s\n",
342 name, strerror(errno)));
343 goto fail;
344 }
345 ret = lseek(tdb->fd, 0, SEEK_SET);
346 if (ret == -1) {
347 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
348 "lseek failed for %s: %s\n",
349 name, strerror(errno)));
350 goto fail;
351 }
352 }
353
354 errno = 0;
355 if (read(tdb->fd, &tdb->header, sizeof(tdb->header)) != sizeof(tdb->header)
356 || strcmp(tdb->header.magic_food, TDB_MAGIC_FOOD) != 0) {
357 if (!(open_flags & O_CREAT) || tdb_new_database(tdb, hash_size) == -1) {
358 if (errno == 0) {
359 errno = EIO; /* ie bad format or something */
360 }
361 goto fail;
362 }
363 rev = (tdb->flags & TDB_CONVERT);
364 } else if (tdb->header.version != TDB_VERSION
365 && !(rev = (tdb->header.version==TDB_BYTEREV(TDB_VERSION)))) {
366 /* wrong version */
367 errno = EIO;
368 goto fail;
369 }
370 vp = (unsigned char *)&tdb->header.version;
371 vertest = (((uint32_t)vp[0]) << 24) | (((uint32_t)vp[1]) << 16) |
372 (((uint32_t)vp[2]) << 8) | (uint32_t)vp[3];
373 tdb->flags |= (vertest==TDB_VERSION) ? TDB_BIGENDIAN : 0;
374 if (!rev)
375 tdb->flags &= ~TDB_CONVERT;
376 else {
377 tdb->flags |= TDB_CONVERT;
378 tdb_convert(&tdb->header, sizeof(tdb->header));
379 }
380 if (fstat(tdb->fd, &st) == -1)
381 goto fail;
382
383 if (tdb->header.rwlocks != 0 &&
384 tdb->header.rwlocks != TDB_HASH_RWLOCK_MAGIC) {
385 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: spinlocks no longer supported\n"));
386 goto fail;
387 }
388
389 if ((tdb->header.magic1_hash == 0) && (tdb->header.magic2_hash == 0)) {
390 /* older TDB without magic hash references */
391 tdb->hash_fn = tdb_old_hash;
392 } else if (!check_header_hash(tdb, !hash_fn, &magic1, &magic2)) {
393 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
394 "%s was not created with %s hash function we are using\n"
395 "magic1_hash[0x%08X %s 0x%08X] "
396 "magic2_hash[0x%08X %s 0x%08X]\n",
397 name, hash_alg,
398 tdb->header.magic1_hash,
399 (tdb->header.magic1_hash == magic1) ? "==" : "!=",
400 magic1,
401 tdb->header.magic2_hash,
402 (tdb->header.magic2_hash == magic2) ? "==" : "!=",
403 magic2));
404 errno = EINVAL;
405 goto fail;
406 }
407
408 /* Is it already in the open list? If so, fail. */
409 if (tdb_already_open(st.st_dev, st.st_ino)) {
410 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: "
411 "%s (%d,%d) is already open in this process\n",
412 name, (int)st.st_dev, (int)st.st_ino));
413 errno = EBUSY;
414 goto fail;
415 }
416
417 tdb->map_size = st.st_size;
418 tdb->device = st.st_dev;
419 tdb->inode = st.st_ino;
420 tdb_mmap(tdb);
421 if (locked) {
422 if (tdb_nest_unlock(tdb, ACTIVE_LOCK, F_WRLCK, false) == -1) {
423 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: "
424 "failed to release ACTIVE_LOCK on %s: %s\n",
425 name, strerror(errno)));
426 goto fail;
427 }
428
429 }
430
431 /* We always need to do this if the CLEAR_IF_FIRST flag is set, even if
432 we didn't get the initial exclusive lock as we need to let all other
433 users know we're using it. */
434
435 if (tdb_flags & TDB_CLEAR_IF_FIRST) {
436 /* leave this lock in place to indicate it's in use */
437 if (tdb_nest_lock(tdb, ACTIVE_LOCK, F_RDLCK, TDB_LOCK_WAIT) == -1) {
438 goto fail;
439 }
440 }
441
442 /* if needed, run recovery */
443 if (tdb_transaction_recover(tdb) == -1) {
444 goto fail;
445 }
446
447#ifdef TDB_TRACE
448 {
449 char tracefile[strlen(name) + 32];
450
451 snprintf(tracefile, sizeof(tracefile),
452 "%s.trace.%li", name, (long)getpid());
453 tdb->tracefd = open(tracefile, O_WRONLY|O_CREAT|O_EXCL, 0600);
454 if (tdb->tracefd >= 0) {
455 tdb_enable_seqnum(tdb);
456 tdb_trace_open(tdb, "tdb_open", hash_size, tdb_flags,
457 open_flags);
458 } else
459 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to open trace file %s!\n", tracefile));
460 }
461#endif
462
463 internal:
464 /* Internal (memory-only) databases skip all the code above to
465 * do with disk files, and resume here by releasing their
466 * open lock and hooking into the active list. */
467 if (tdb_nest_unlock(tdb, OPEN_LOCK, F_WRLCK, false) == -1) {
468 goto fail;
469 }
470 tdb->next = tdbs;
471 tdbs = tdb;
472 return tdb;
473
474 fail:
475 { int save_errno = errno;
476
477#ifdef __OS2__
478 close(tdb->hActiveLock);
479 tdb->hActiveLock = -1;
480#endif
481 if (!tdb)
482 return NULL;
483
484#ifdef TDB_TRACE
485 close(tdb->tracefd);
486#endif
487 if (tdb->map_ptr) {
488 if (tdb->flags & TDB_INTERNAL)
489 SAFE_FREE(tdb->map_ptr);
490 else
491 tdb_munmap(tdb);
492 }
493 if (tdb->fd != -1)
494 if (close(tdb->fd) != 0)
495 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to close tdb->fd on error!\n"));
496 SAFE_FREE(tdb->lockrecs);
497 SAFE_FREE(tdb->name);
498 SAFE_FREE(tdb);
499 errno = save_errno;
500 return NULL;
501 }
502}
503
504/*
505 * Set the maximum number of dead records per hash chain
506 */
507
508_PUBLIC_ void tdb_set_max_dead(struct tdb_context *tdb, int max_dead)
509{
510 tdb->max_dead_records = max_dead;
511}
512
513/**
514 * Close a database.
515 *
516 * @returns -1 for error; 0 for success.
517 **/
518_PUBLIC_ int tdb_close(struct tdb_context *tdb)
519{
520 struct tdb_context **i;
521 int ret = 0;
522
523 if (tdb->transaction) {
524 tdb_transaction_cancel(tdb);
525 }
526 tdb_trace(tdb, "tdb_close");
527
528 if (tdb->map_ptr) {
529 if (tdb->flags & TDB_INTERNAL)
530 SAFE_FREE(tdb->map_ptr);
531 else
532 tdb_munmap(tdb);
533 }
534 SAFE_FREE(tdb->name);
535 if (tdb->fd != -1) {
536 ret = close(tdb->fd);
537 tdb->fd = -1;
538 }
539 SAFE_FREE(tdb->lockrecs);
540
541 /* Remove from contexts list */
542 for (i = &tdbs; *i; i = &(*i)->next) {
543 if (*i == tdb) {
544 *i = tdb->next;
545 break;
546 }
547 }
548
549#ifdef __OS2__
550 close(tdb->hActiveLock);
551 tdb->hActiveLock = -1;
552#endif
553
554#ifdef TDB_TRACE
555 close(tdb->tracefd);
556#endif
557 memset(tdb, 0, sizeof(*tdb));
558 SAFE_FREE(tdb);
559
560 return ret;
561}
562
563/* register a loging function */
564_PUBLIC_ void tdb_set_logging_function(struct tdb_context *tdb,
565 const struct tdb_logging_context *log_ctx)
566{
567 tdb->log = *log_ctx;
568}
569
570_PUBLIC_ void *tdb_get_logging_private(struct tdb_context *tdb)
571{
572 return tdb->log.log_private;
573}
574
575static int tdb_reopen_internal(struct tdb_context *tdb, bool active_lock)
576{
577#if !defined(LIBREPLACE_PREAD_NOT_REPLACED) || \
578 !defined(LIBREPLACE_PWRITE_NOT_REPLACED)
579 struct stat st;
580#endif
581
582 if (tdb->flags & TDB_INTERNAL) {
583 return 0; /* Nothing to do. */
584 }
585
586 if (tdb_have_extra_locks(tdb)) {
587 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_reopen: reopen not allowed with locks held\n"));
588 goto fail;
589 }
590
591 if (tdb->transaction != 0) {
592 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_reopen: reopen not allowed inside a transaction\n"));
593 goto fail;
594 }
595
596/* If we have real pread & pwrite, we can skip reopen. */
597#if !defined(LIBREPLACE_PREAD_NOT_REPLACED) || \
598 !defined(LIBREPLACE_PWRITE_NOT_REPLACED)
599 if (tdb_munmap(tdb) != 0) {
600 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: munmap failed (%s)\n", strerror(errno)));
601 goto fail;
602 }
603 if (close(tdb->fd) != 0)
604 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: WARNING closing tdb->fd failed!\n"));
605 tdb->fd = open(tdb->name, tdb->open_flags & ~(O_CREAT|O_TRUNC), 0);
606 if (tdb->fd == -1) {
607 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: open failed (%s)\n", strerror(errno)));
608 goto fail;
609 }
610 if (fstat(tdb->fd, &st) != 0) {
611 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: fstat failed (%s)\n", strerror(errno)));
612 goto fail;
613 }
614 if (st.st_ino != tdb->inode || st.st_dev != tdb->device) {
615 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: file dev/inode has changed!\n"));
616 goto fail;
617 }
618 tdb_mmap(tdb);
619#endif /* fake pread or pwrite */
620
621#ifdef __OS2__
622 close(tdb->hActiveLock);
623 tdb->hActiveLock = -1;
624
625 if (os2_crtActiveLock(tdb, tdb->name, "tdb_reopen") != 0)
626 goto fail;
627#endif
628 /* We may still think we hold the active lock. */
629 tdb->num_lockrecs = 0;
630 SAFE_FREE(tdb->lockrecs);
631
632 if (active_lock && tdb_nest_lock(tdb, ACTIVE_LOCK, F_RDLCK, TDB_LOCK_WAIT) == -1) {
633 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: failed to obtain active lock\n"));
634 goto fail;
635 }
636
637 return 0;
638
639fail:
640 tdb_close(tdb);
641 return -1;
642}
643
644/* reopen a tdb - this can be used after a fork to ensure that we have an independent
645 seek pointer from our parent and to re-establish locks */
646_PUBLIC_ int tdb_reopen(struct tdb_context *tdb)
647{
648 return tdb_reopen_internal(tdb, tdb->flags & TDB_CLEAR_IF_FIRST);
649}
650
651/* reopen all tdb's */
652_PUBLIC_ int tdb_reopen_all(int parent_longlived)
653{
654 struct tdb_context *tdb;
655
656 for (tdb=tdbs; tdb; tdb = tdb->next) {
657 bool active_lock = (tdb->flags & TDB_CLEAR_IF_FIRST);
658
659 /*
660 * If the parent is longlived (ie. a
661 * parent daemon architecture), we know
662 * it will keep it's active lock on a
663 * tdb opened with CLEAR_IF_FIRST. Thus
664 * for child processes we don't have to
665 * add an active lock. This is essential
666 * to improve performance on systems that
667 * keep POSIX locks as a non-scalable data
668 * structure in the kernel.
669 */
670 if (parent_longlived) {
671 /* Ensure no clear-if-first. */
672 active_lock = false;
673 }
674
675 if (tdb_reopen_internal(tdb, active_lock) != 0)
676 return -1;
677 }
678
679 return 0;
680}
681#ifdef __OS2__
682int os2_crtActiveLock(struct tdb_context *tdb, const char *name, const char *origin)
683{
684 // name could be null, so handle it
685 if (name == NULL)
686 return 0;
687
688 struct stat st;
689 bool emptytdb = false;
690 char activeLockName[_MAX_PATH];
691 char *emptyString = "used for active lock\n\0";
692 sprintf(activeLockName, "%s_AL", name);
693
694 if ((stat(activeLockName, &st) == -1) || (st.st_size < strlen(emptyString)))
695 emptytdb = true;
696
697 tdb->hActiveLock = open(activeLockName, tdb->open_flags | O_CREAT, 0777);
698 if (tdb->hActiveLock == -1) {
699 TDB_LOG((tdb, TDB_DEBUG_ERROR, "os2_crtActiveLock: cannot create activeLock %s called from %s %s\n",
700 activeLockName, origin, strerror(errno)));
701 errno = EINVAL;
702 return -1;
703 }
704
705 // we try to truncate the db when called from tdb_open_ex
706 // but if it's not working it's ok as well
707 if (emptytdb)
708 tdb_write_all(tdb->hActiveLock, emptyString, strlen(emptyString));
709
710 return 0;
711}
712#endif
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