tdb: return ENOSYS if the tdb was created with spinlocks.
[Samba/wip.git] / lib / tdb / common / open.c
blobd5c043211115e1b7d2ba3337919a092c8ce3bb99
1 /*
2 Unix SMB/CIFS implementation.
4 trivial database library
6 Copyright (C) Andrew Tridgell 1999-2005
7 Copyright (C) Paul `Rusty' Russell 2000
8 Copyright (C) Jeremy Allison 2000-2003
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
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.
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.
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/>.
28 #include "tdb_private.h"
30 /* all contexts, to ensure no double-opens (fcntl locks don't nest!) */
31 static struct tdb_context *tdbs = NULL;
33 /* We use two hashes to double-check they're using the right hash function. */
34 void tdb_header_hash(struct tdb_context *tdb,
35 uint32_t *magic1_hash, uint32_t *magic2_hash)
37 TDB_DATA hash_key;
38 uint32_t tdb_magic = TDB_MAGIC;
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);
44 hash_key.dptr = (unsigned char *)CONVERT(tdb_magic);
45 hash_key.dsize = sizeof(tdb_magic);
46 *magic2_hash = tdb->hash_fn(&hash_key);
48 /* Make sure at least one hash is non-zero! */
49 if (*magic1_hash == 0 && *magic2_hash == 0)
50 *magic1_hash = 1;
53 /* initialise a new database with a specified hash size */
54 static int tdb_new_database(struct tdb_context *tdb, struct tdb_header *header,
55 int hash_size)
57 struct tdb_header *newdb;
58 size_t size;
59 int ret = -1;
61 /* We make it up in memory, then write it out if not internal */
62 size = sizeof(struct tdb_header) + (hash_size+1)*sizeof(tdb_off_t);
63 if (!(newdb = (struct tdb_header *)calloc(size, 1))) {
64 tdb->ecode = TDB_ERR_OOM;
65 return -1;
68 /* Fill in the header */
69 newdb->version = TDB_VERSION;
70 newdb->hash_size = hash_size;
72 tdb_header_hash(tdb, &newdb->magic1_hash, &newdb->magic2_hash);
74 /* Make sure older tdbs (which don't check the magic hash fields)
75 * will refuse to open this TDB. */
76 if (tdb->flags & TDB_INCOMPATIBLE_HASH)
77 newdb->rwlocks = TDB_HASH_RWLOCK_MAGIC;
79 if (tdb->flags & TDB_INTERNAL) {
80 tdb->map_size = size;
81 tdb->map_ptr = (char *)newdb;
82 memcpy(header, newdb, sizeof(*header));
83 /* Convert the `ondisk' version if asked. */
84 CONVERT(*newdb);
85 return 0;
87 if (lseek(tdb->fd, 0, SEEK_SET) == -1)
88 goto fail;
90 if (ftruncate(tdb->fd, 0) == -1)
91 goto fail;
93 /* This creates an endian-converted header, as if read from disk */
94 CONVERT(*newdb);
95 memcpy(header, newdb, sizeof(*header));
96 /* Don't endian-convert the magic food! */
97 memcpy(newdb->magic_food, TDB_MAGIC_FOOD, strlen(TDB_MAGIC_FOOD)+1);
99 if (!tdb_write_all(tdb->fd, newdb, size))
100 goto fail;
102 ret = 0;
103 fail:
104 SAFE_FREE(newdb);
105 return ret;
110 static int tdb_already_open(dev_t device,
111 ino_t ino)
113 struct tdb_context *i;
115 for (i = tdbs; i; i = i->next) {
116 if (i->device == device && i->inode == ino) {
117 return 1;
121 return 0;
124 /* open the database, creating it if necessary
126 The open_flags and mode are passed straight to the open call on the
127 database file. A flags value of O_WRONLY is invalid. The hash size
128 is advisory, use zero for a default value.
130 Return is NULL on error, in which case errno is also set. Don't
131 try to call tdb_error or tdb_errname, just do strerror(errno).
133 @param name may be NULL for internal databases. */
134 _PUBLIC_ struct tdb_context *tdb_open(const char *name, int hash_size, int tdb_flags,
135 int open_flags, mode_t mode)
137 return tdb_open_ex(name, hash_size, tdb_flags, open_flags, mode, NULL, NULL);
140 /* a default logging function */
141 static void null_log_fn(struct tdb_context *tdb, enum tdb_debug_level level, const char *fmt, ...) PRINTF_ATTRIBUTE(3, 4);
142 static void null_log_fn(struct tdb_context *tdb, enum tdb_debug_level level, const char *fmt, ...)
146 static bool check_header_hash(struct tdb_context *tdb,
147 struct tdb_header *header,
148 bool default_hash, uint32_t *m1, uint32_t *m2)
150 tdb_header_hash(tdb, m1, m2);
151 if (header->magic1_hash == *m1 &&
152 header->magic2_hash == *m2) {
153 return true;
156 /* If they explicitly set a hash, always respect it. */
157 if (!default_hash)
158 return false;
160 /* Otherwise, try the other inbuilt hash. */
161 if (tdb->hash_fn == tdb_old_hash)
162 tdb->hash_fn = tdb_jenkins_hash;
163 else
164 tdb->hash_fn = tdb_old_hash;
165 return check_header_hash(tdb, header, false, m1, m2);
168 _PUBLIC_ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
169 int open_flags, mode_t mode,
170 const struct tdb_logging_context *log_ctx,
171 tdb_hash_func hash_fn)
173 int orig_errno = errno;
174 struct tdb_header header;
175 struct tdb_context *tdb;
176 struct stat st;
177 int rev = 0, locked = 0;
178 unsigned char *vp;
179 uint32_t vertest;
180 unsigned v;
181 const char *hash_alg;
182 uint32_t magic1, magic2;
184 ZERO_STRUCT(header);
186 if (!(tdb = (struct tdb_context *)calloc(1, sizeof *tdb))) {
187 /* Can't log this */
188 errno = ENOMEM;
189 goto fail;
191 tdb_io_init(tdb);
193 if (tdb_flags & TDB_INTERNAL) {
194 tdb_flags |= TDB_INCOMPATIBLE_HASH;
197 tdb->fd = -1;
198 #ifdef TDB_TRACE
199 tdb->tracefd = -1;
200 #endif
201 tdb->name = NULL;
202 tdb->map_ptr = NULL;
203 tdb->flags = tdb_flags;
204 tdb->open_flags = open_flags;
205 if (log_ctx) {
206 tdb->log = *log_ctx;
207 } else {
208 tdb->log.log_fn = null_log_fn;
209 tdb->log.log_private = NULL;
212 if (name == NULL && (tdb_flags & TDB_INTERNAL)) {
213 name = "__TDB_INTERNAL__";
216 if (name == NULL) {
217 tdb->name = discard_const_p(char, "__NULL__");
218 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: called with name == NULL\n"));
219 tdb->name = NULL;
220 errno = EINVAL;
221 goto fail;
224 /* now make a copy of the name, as the caller memory might go away */
225 if (!(tdb->name = (char *)strdup(name))) {
227 * set the name as the given string, so that tdb_name() will
228 * work in case of an error.
230 tdb->name = discard_const_p(char, name);
231 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: can't strdup(%s)\n",
232 name));
233 tdb->name = NULL;
234 errno = ENOMEM;
235 goto fail;
238 if (hash_fn) {
239 tdb->hash_fn = hash_fn;
240 hash_alg = "the user defined";
241 } else {
242 /* This controls what we use when creating a tdb. */
243 if (tdb->flags & TDB_INCOMPATIBLE_HASH) {
244 tdb->hash_fn = tdb_jenkins_hash;
245 } else {
246 tdb->hash_fn = tdb_old_hash;
248 hash_alg = "either default";
251 /* cache the page size */
252 tdb->page_size = getpagesize();
253 if (tdb->page_size <= 0) {
254 tdb->page_size = 0x2000;
257 tdb->max_dead_records = (tdb_flags & TDB_VOLATILE) ? 5 : 0;
259 if ((open_flags & O_ACCMODE) == O_WRONLY) {
260 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: can't open tdb %s write-only\n",
261 name));
262 errno = EINVAL;
263 goto fail;
266 if (hash_size == 0)
267 hash_size = DEFAULT_HASH_SIZE;
268 if ((open_flags & O_ACCMODE) == O_RDONLY) {
269 tdb->read_only = 1;
270 /* read only databases don't do locking or clear if first */
271 tdb->flags |= TDB_NOLOCK;
272 tdb->flags &= ~TDB_CLEAR_IF_FIRST;
275 if ((tdb->flags & TDB_ALLOW_NESTING) &&
276 (tdb->flags & TDB_DISALLOW_NESTING)) {
277 tdb->ecode = TDB_ERR_NESTING;
278 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
279 "allow_nesting and disallow_nesting are not allowed together!"));
280 errno = EINVAL;
281 goto fail;
284 if (getenv("TDB_NO_FSYNC")) {
285 tdb->flags |= TDB_NOSYNC;
289 * TDB_ALLOW_NESTING is the default behavior.
290 * Note: this may change in future versions!
292 if (!(tdb->flags & TDB_DISALLOW_NESTING)) {
293 tdb->flags |= TDB_ALLOW_NESTING;
296 /* internal databases don't mmap or lock, and start off cleared */
297 if (tdb->flags & TDB_INTERNAL) {
298 tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);
299 tdb->flags &= ~TDB_CLEAR_IF_FIRST;
300 if (tdb_new_database(tdb, &header, hash_size) != 0) {
301 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: tdb_new_database failed!"));
302 goto fail;
304 tdb->hash_size = hash_size;
305 goto internal;
308 if ((tdb->fd = open(name, open_flags, mode)) == -1) {
309 TDB_LOG((tdb, TDB_DEBUG_WARNING, "tdb_open_ex: could not open file %s: %s\n",
310 name, strerror(errno)));
311 goto fail; /* errno set by open(2) */
314 /* on exec, don't inherit the fd */
315 v = fcntl(tdb->fd, F_GETFD, 0);
316 fcntl(tdb->fd, F_SETFD, v | FD_CLOEXEC);
318 /* ensure there is only one process initialising at once */
319 if (tdb_nest_lock(tdb, OPEN_LOCK, F_WRLCK, TDB_LOCK_WAIT) == -1) {
320 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to get open lock on %s: %s\n",
321 name, strerror(errno)));
322 goto fail; /* errno set by tdb_brlock */
325 /* we need to zero database if we are the only one with it open */
326 if ((tdb_flags & TDB_CLEAR_IF_FIRST) &&
327 (!tdb->read_only) &&
328 (locked = (tdb_nest_lock(tdb, ACTIVE_LOCK, F_WRLCK, TDB_LOCK_NOWAIT|TDB_LOCK_PROBE) == 0))) {
329 int ret;
330 ret = tdb_brlock(tdb, F_WRLCK, FREELIST_TOP, 0,
331 TDB_LOCK_WAIT);
332 if (ret == -1) {
333 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
334 "tdb_brlock failed for %s: %s\n",
335 name, strerror(errno)));
336 goto fail;
338 ret = tdb_new_database(tdb, &header, hash_size);
339 if (ret == -1) {
340 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
341 "tdb_new_database failed for %s: %s\n",
342 name, strerror(errno)));
343 tdb_unlockall(tdb);
344 goto fail;
346 ret = tdb_brunlock(tdb, F_WRLCK, FREELIST_TOP, 0);
347 if (ret == -1) {
348 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
349 "tdb_unlockall failed for %s: %s\n",
350 name, strerror(errno)));
351 goto fail;
353 ret = lseek(tdb->fd, 0, SEEK_SET);
354 if (ret == -1) {
355 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
356 "lseek failed for %s: %s\n",
357 name, strerror(errno)));
358 goto fail;
362 errno = 0;
363 if (read(tdb->fd, &header, sizeof(header)) != sizeof(header)
364 || strcmp(header.magic_food, TDB_MAGIC_FOOD) != 0) {
365 if (!(open_flags & O_CREAT) ||
366 tdb_new_database(tdb, &header, hash_size) == -1) {
367 if (errno == 0) {
368 errno = EIO; /* ie bad format or something */
370 goto fail;
372 rev = (tdb->flags & TDB_CONVERT);
373 } else if (header.version != TDB_VERSION
374 && !(rev = (header.version==TDB_BYTEREV(TDB_VERSION)))) {
375 /* wrong version */
376 errno = EIO;
377 goto fail;
379 vp = (unsigned char *)&header.version;
380 vertest = (((uint32_t)vp[0]) << 24) | (((uint32_t)vp[1]) << 16) |
381 (((uint32_t)vp[2]) << 8) | (uint32_t)vp[3];
382 tdb->flags |= (vertest==TDB_VERSION) ? TDB_BIGENDIAN : 0;
383 if (!rev)
384 tdb->flags &= ~TDB_CONVERT;
385 else {
386 tdb->flags |= TDB_CONVERT;
387 tdb_convert(&header, sizeof(header));
389 if (fstat(tdb->fd, &st) == -1)
390 goto fail;
392 if (header.rwlocks != 0 &&
393 header.rwlocks != TDB_HASH_RWLOCK_MAGIC) {
394 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: spinlocks no longer supported\n"));
395 errno = ENOSYS;
396 goto fail;
398 tdb->hash_size = header.hash_size;
400 if ((header.magic1_hash == 0) && (header.magic2_hash == 0)) {
401 /* older TDB without magic hash references */
402 tdb->hash_fn = tdb_old_hash;
403 } else if (!check_header_hash(tdb, &header, !hash_fn,
404 &magic1, &magic2)) {
405 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
406 "%s was not created with %s hash function we are using\n"
407 "magic1_hash[0x%08X %s 0x%08X] "
408 "magic2_hash[0x%08X %s 0x%08X]\n",
409 name, hash_alg,
410 header.magic1_hash,
411 (header.magic1_hash == magic1) ? "==" : "!=",
412 magic1,
413 header.magic2_hash,
414 (header.magic2_hash == magic2) ? "==" : "!=",
415 magic2));
416 errno = EINVAL;
417 goto fail;
420 /* Is it already in the open list? If so, fail. */
421 if (tdb_already_open(st.st_dev, st.st_ino)) {
422 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: "
423 "%s (%d,%d) is already open in this process\n",
424 name, (int)st.st_dev, (int)st.st_ino));
425 errno = EBUSY;
426 goto fail;
429 /* Beware truncation! */
430 tdb->map_size = st.st_size;
431 if (tdb->map_size != st.st_size) {
432 /* Ensure ecode is set for log fn. */
433 tdb->ecode = TDB_ERR_IO;
434 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
435 "len %llu too large!\n", (long long)st.st_size));
436 errno = EIO;
437 goto fail;
440 tdb->device = st.st_dev;
441 tdb->inode = st.st_ino;
442 tdb_mmap(tdb);
443 if (locked) {
444 if (tdb_nest_unlock(tdb, ACTIVE_LOCK, F_WRLCK, false) == -1) {
445 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: "
446 "failed to release ACTIVE_LOCK on %s: %s\n",
447 name, strerror(errno)));
448 goto fail;
453 /* We always need to do this if the CLEAR_IF_FIRST flag is set, even if
454 we didn't get the initial exclusive lock as we need to let all other
455 users know we're using it. */
457 if (tdb_flags & TDB_CLEAR_IF_FIRST) {
458 /* leave this lock in place to indicate it's in use */
459 if (tdb_nest_lock(tdb, ACTIVE_LOCK, F_RDLCK, TDB_LOCK_WAIT) == -1) {
460 goto fail;
464 /* if needed, run recovery */
465 if (tdb_transaction_recover(tdb) == -1) {
466 goto fail;
469 #ifdef TDB_TRACE
471 char tracefile[strlen(name) + 32];
473 snprintf(tracefile, sizeof(tracefile),
474 "%s.trace.%li", name, (long)getpid());
475 tdb->tracefd = open(tracefile, O_WRONLY|O_CREAT|O_EXCL, 0600);
476 if (tdb->tracefd >= 0) {
477 tdb_enable_seqnum(tdb);
478 tdb_trace_open(tdb, "tdb_open", hash_size, tdb_flags,
479 open_flags);
480 } else
481 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to open trace file %s!\n", tracefile));
483 #endif
485 internal:
486 /* Internal (memory-only) databases skip all the code above to
487 * do with disk files, and resume here by releasing their
488 * open lock and hooking into the active list. */
489 if (tdb_nest_unlock(tdb, OPEN_LOCK, F_WRLCK, false) == -1) {
490 goto fail;
492 tdb->next = tdbs;
493 tdbs = tdb;
494 errno = orig_errno;
495 return tdb;
497 fail:
498 { int save_errno = errno;
500 if (!tdb)
501 return NULL;
503 #ifdef TDB_TRACE
504 close(tdb->tracefd);
505 #endif
506 if (tdb->map_ptr) {
507 if (tdb->flags & TDB_INTERNAL)
508 SAFE_FREE(tdb->map_ptr);
509 else
510 tdb_munmap(tdb);
512 if (tdb->fd != -1)
513 if (close(tdb->fd) != 0)
514 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to close tdb->fd on error!\n"));
515 SAFE_FREE(tdb->lockrecs);
516 SAFE_FREE(tdb->name);
517 SAFE_FREE(tdb);
518 errno = save_errno;
519 return NULL;
524 * Set the maximum number of dead records per hash chain
527 _PUBLIC_ void tdb_set_max_dead(struct tdb_context *tdb, int max_dead)
529 tdb->max_dead_records = max_dead;
533 * Close a database.
535 * @returns -1 for error; 0 for success.
537 _PUBLIC_ int tdb_close(struct tdb_context *tdb)
539 struct tdb_context **i;
540 int ret = 0;
542 if (tdb->transaction) {
543 tdb_transaction_cancel(tdb);
545 tdb_trace(tdb, "tdb_close");
547 if (tdb->map_ptr) {
548 if (tdb->flags & TDB_INTERNAL)
549 SAFE_FREE(tdb->map_ptr);
550 else
551 tdb_munmap(tdb);
553 SAFE_FREE(tdb->name);
554 if (tdb->fd != -1) {
555 ret = close(tdb->fd);
556 tdb->fd = -1;
558 SAFE_FREE(tdb->lockrecs);
560 /* Remove from contexts list */
561 for (i = &tdbs; *i; i = &(*i)->next) {
562 if (*i == tdb) {
563 *i = tdb->next;
564 break;
568 #ifdef TDB_TRACE
569 close(tdb->tracefd);
570 #endif
571 memset(tdb, 0, sizeof(*tdb));
572 SAFE_FREE(tdb);
574 return ret;
577 /* register a loging function */
578 _PUBLIC_ void tdb_set_logging_function(struct tdb_context *tdb,
579 const struct tdb_logging_context *log_ctx)
581 tdb->log = *log_ctx;
584 _PUBLIC_ void *tdb_get_logging_private(struct tdb_context *tdb)
586 return tdb->log.log_private;
589 static int tdb_reopen_internal(struct tdb_context *tdb, bool active_lock)
591 #if !defined(LIBREPLACE_PREAD_NOT_REPLACED) || \
592 !defined(LIBREPLACE_PWRITE_NOT_REPLACED)
593 struct stat st;
594 #endif
596 if (tdb->flags & TDB_INTERNAL) {
597 return 0; /* Nothing to do. */
600 if (tdb_have_extra_locks(tdb)) {
601 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_reopen: reopen not allowed with locks held\n"));
602 goto fail;
605 if (tdb->transaction != 0) {
606 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_reopen: reopen not allowed inside a transaction\n"));
607 goto fail;
610 /* If we have real pread & pwrite, we can skip reopen. */
611 #if !defined(LIBREPLACE_PREAD_NOT_REPLACED) || \
612 !defined(LIBREPLACE_PWRITE_NOT_REPLACED)
613 if (tdb_munmap(tdb) != 0) {
614 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: munmap failed (%s)\n", strerror(errno)));
615 goto fail;
617 if (close(tdb->fd) != 0)
618 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: WARNING closing tdb->fd failed!\n"));
619 tdb->fd = open(tdb->name, tdb->open_flags & ~(O_CREAT|O_TRUNC), 0);
620 if (tdb->fd == -1) {
621 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: open failed (%s)\n", strerror(errno)));
622 goto fail;
624 if (fstat(tdb->fd, &st) != 0) {
625 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: fstat failed (%s)\n", strerror(errno)));
626 goto fail;
628 if (st.st_ino != tdb->inode || st.st_dev != tdb->device) {
629 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: file dev/inode has changed!\n"));
630 goto fail;
632 if (tdb_mmap(tdb) != 0) {
633 goto fail;
635 #endif /* fake pread or pwrite */
637 /* We may still think we hold the active lock. */
638 tdb->num_lockrecs = 0;
639 SAFE_FREE(tdb->lockrecs);
640 tdb->lockrecs_array_length = 0;
642 if (active_lock && tdb_nest_lock(tdb, ACTIVE_LOCK, F_RDLCK, TDB_LOCK_WAIT) == -1) {
643 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: failed to obtain active lock\n"));
644 goto fail;
647 return 0;
649 fail:
650 tdb_close(tdb);
651 return -1;
654 /* reopen a tdb - this can be used after a fork to ensure that we have an independent
655 seek pointer from our parent and to re-establish locks */
656 _PUBLIC_ int tdb_reopen(struct tdb_context *tdb)
658 return tdb_reopen_internal(tdb, tdb->flags & TDB_CLEAR_IF_FIRST);
661 /* reopen all tdb's */
662 _PUBLIC_ int tdb_reopen_all(int parent_longlived)
664 struct tdb_context *tdb;
666 for (tdb=tdbs; tdb; tdb = tdb->next) {
667 bool active_lock = (tdb->flags & TDB_CLEAR_IF_FIRST);
670 * If the parent is longlived (ie. a
671 * parent daemon architecture), we know
672 * it will keep it's active lock on a
673 * tdb opened with CLEAR_IF_FIRST. Thus
674 * for child processes we don't have to
675 * add an active lock. This is essential
676 * to improve performance on systems that
677 * keep POSIX locks as a non-scalable data
678 * structure in the kernel.
680 if (parent_longlived) {
681 /* Ensure no clear-if-first. */
682 active_lock = false;
685 if (tdb_reopen_internal(tdb, active_lock) != 0)
686 return -1;
689 return 0;