source: branches/samba-3.3.x/source/lib/tdb/common/open.c

Last change on this file was 273, checked in by Silvan Scherrer, 16 years ago

mutex lock fix
File size: 17.9 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#ifdef __OS2__
31// nmbd.c sets it to 1
32int global_Sem32Add = 0;
33#endif
34
35/* all contexts, to ensure no double-opens (fcntl locks don't nest!) */
36static struct tdb_context *tdbs = NULL;
37
38
39/* This is based on the hash algorithm from gdbm */
40static unsigned int default_tdb_hash(TDB_DATA *key)
41{
42 uint32_t value; /* Used to compute the hash value. */
43 uint32_t i; /* Used to cycle through random values. */
44
45 /* Set the initial value from the key size. */
46 for (value = 0x238F13AF * key->dsize, i=0; i < key->dsize; i++)
47 value = (value + (key->dptr[i] << (i*5 % 24)));
48
49 return (1103515243 * value + 12345);
50}
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 ssize_t written;
60
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 return TDB_ERRCODE(TDB_ERR_OOM, -1);
65
66 /* Fill in the header */
67 newdb->version = TDB_VERSION;
68 newdb->hash_size = hash_size;
69 if (tdb->flags & TDB_INTERNAL) {
70 tdb->map_size = size;
71 tdb->map_ptr = (char *)newdb;
72 memcpy(&tdb->header, newdb, sizeof(tdb->header));
73 /* Convert the `ondisk' version if asked. */
74 CONVERT(*newdb);
75 return 0;
76 }
77 if (lseek(tdb->fd, 0, SEEK_SET) == -1)
78 goto fail;
79
80 if (ftruncate(tdb->fd, 0) == -1)
81 goto fail;
82
83 /* This creates an endian-converted header, as if read from disk */
84 CONVERT(*newdb);
85 memcpy(&tdb->header, newdb, sizeof(tdb->header));
86 /* Don't endian-convert the magic food! */
87 memcpy(newdb->magic_food, TDB_MAGIC_FOOD, strlen(TDB_MAGIC_FOOD)+1);
88 /* we still have "ret == -1" here */
89 written = write(tdb->fd, newdb, size);
90 if (written == size) {
91 ret = 0;
92 } else if (written != -1) {
93 /* call write once again, this usually should return -1 and
94 * set errno appropriately */
95 size -= written;
96 written = write(tdb->fd, newdb+written, size);
97 if (written == size) {
98 ret = 0;
99 } else if (written >= 0) {
100 /* a second incomplete write - we give up.
101 * guessing the errno... */
102 errno = ENOSPC;
103 }
104 }
105
106 fail:
107 SAFE_FREE(newdb);
108 return ret;
109}
110
111
112
113static int tdb_already_open(dev_t device,
114 ino_t ino)
115{
116 struct tdb_context *i;
117
118 for (i = tdbs; i; i = i->next) {
119 if (i->device == device && i->inode == ino) {
120 return 1;
121 }
122 }
123
124 return 0;
125}
126
127/* open the database, creating it if necessary
128
129 The open_flags and mode are passed straight to the open call on the
130 database file. A flags value of O_WRONLY is invalid. The hash size
131 is advisory, use zero for a default value.
132
133 Return is NULL on error, in which case errno is also set. Don't
134 try to call tdb_error or tdb_errname, just do strerror(errno).
135
136 @param name may be NULL for internal databases. */
137struct tdb_context *tdb_open(const char *name, int hash_size, int tdb_flags,
138 int open_flags, mode_t mode)
139{
140 return tdb_open_ex(name, hash_size, tdb_flags, open_flags, mode, NULL, NULL);
141}
142
143/* a default logging function */
144static void null_log_fn(struct tdb_context *tdb, enum tdb_debug_level level, const char *fmt, ...) PRINTF_ATTRIBUTE(3, 4);
145static void null_log_fn(struct tdb_context *tdb, enum tdb_debug_level level, const char *fmt, ...)
146{
147}
148
149
150struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
151 int open_flags, mode_t mode,
152 const struct tdb_logging_context *log_ctx,
153 tdb_hash_func hash_fn)
154{
155 struct tdb_context *tdb;
156 struct stat st;
157 int rev = 0, locked = 0;
158 unsigned char *vp;
159 uint32_t vertest;
160 unsigned v;
161
162 if (!(tdb = (struct tdb_context *)calloc(1, sizeof *tdb))) {
163 /* Can't log this */
164 errno = ENOMEM;
165 goto fail;
166 }
167 tdb_io_init(tdb);
168 tdb->fd = -1;
169 tdb->name = NULL;
170 tdb->map_ptr = NULL;
171 tdb->flags = tdb_flags;
172 tdb->open_flags = open_flags;
173 if (log_ctx) {
174 tdb->log = *log_ctx;
175 } else {
176 tdb->log.log_fn = null_log_fn;
177 tdb->log.log_private = NULL;
178 }
179 tdb->hash_fn = hash_fn ? hash_fn : default_tdb_hash;
180
181#ifdef __OS2__
182 if (!(tdb->flags & TDB_INTERNAL))
183 {
184 char szSem[_MAX_PATH];
185 char drive[_MAX_DRIVE], dir[_MAX_DIR];
186 char fname[_MAX_FNAME], ext[_MAX_EXT];
187 APIRET rc;
188 // extract path info
189 _splitpath( name, drive, dir, fname, ext);
190 sprintf( szSem, "\\SEM32\\TDB_GL_%s%s%s%i", dir, fname, ext, global_Sem32Add);
191 rc = DosCreateMutexSem( szSem, &tdb->hGlobalLock, 0, FALSE);
192 if (rc == ERROR_DUPLICATE_NAME)
193 rc = DosOpenMutexSem( szSem, &tdb->hGlobalLock);
194 if (rc != NO_ERROR) {
195 printf( "cannot open %s %d\n", szSem, rc);
196 errno = EINVAL;
197 goto fail;
198 }
199 TDB_LOG((tdb, TDB_DEBUG_TRACE,"tdb_open_ex pid %d global handle %d\n", getpid(), tdb->hGlobalLock));
200 sprintf( szSem, "\\SEM32\\TDB_AL_%s%s%s%i", dir, fname, ext, global_Sem32Add);
201 rc = DosCreateMutexSem( szSem, &tdb->hActiveLock, 0, FALSE);
202 if (rc == ERROR_DUPLICATE_NAME)
203 rc = DosOpenMutexSem( szSem, &tdb->hActiveLock);
204 if (rc != NO_ERROR) {
205 printf( "cannot open %s %d\n", szSem, rc);
206 errno = EINVAL;
207 goto fail;
208 }
209 TDB_LOG((tdb, TDB_DEBUG_TRACE,"tdb_open_ex pid %d active handle %d\n", getpid(), tdb->hActiveLock));
210 sprintf( szSem, "\\SEM32\\TDB_TL_%s%s%s%i", dir, fname, ext, global_Sem32Add);
211 rc = DosCreateMutexSem( szSem, &tdb->hTransactionLock, 0, FALSE);
212 if (rc == ERROR_DUPLICATE_NAME)
213 rc = DosOpenMutexSem( szSem, &tdb->hTransactionLock);
214 if (rc != NO_ERROR) {
215 printf( "cannot open %s %d\n", szSem, rc);
216 errno = EINVAL;
217 goto fail;
218 }
219 TDB_LOG((tdb, TDB_DEBUG_TRACE,"tdb_open_ex pid %d transaction handle %d\n", getpid(), tdb->hTransactionLock));
220 }
221#endif
222
223 /* cache the page size */
224 tdb->page_size = getpagesize();
225 if (tdb->page_size <= 0) {
226 tdb->page_size = 0x2000;
227 }
228
229 tdb->max_dead_records = (tdb_flags & TDB_VOLATILE) ? 5 : 0;
230
231 if ((open_flags & O_ACCMODE) == O_WRONLY) {
232 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: can't open tdb %s write-only\n",
233 name));
234 errno = EINVAL;
235 goto fail;
236 }
237
238 if (hash_size == 0)
239 hash_size = DEFAULT_HASH_SIZE;
240 if ((open_flags & O_ACCMODE) == O_RDONLY) {
241 tdb->read_only = 1;
242 /* read only databases don't do locking or clear if first */
243 tdb->flags |= TDB_NOLOCK;
244 tdb->flags &= ~TDB_CLEAR_IF_FIRST;
245 }
246
247 /* internal databases don't mmap or lock, and start off cleared */
248 if (tdb->flags & TDB_INTERNAL) {
249 tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);
250 tdb->flags &= ~TDB_CLEAR_IF_FIRST;
251 if (tdb_new_database(tdb, hash_size) != 0) {
252 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: tdb_new_database failed!"));
253 goto fail;
254 }
255 goto internal;
256 }
257
258 if ((tdb->fd = open(name, open_flags, mode)) == -1) {
259 TDB_LOG((tdb, TDB_DEBUG_WARNING, "tdb_open_ex: could not open file %s: %s\n",
260 name, strerror(errno)));
261 goto fail; /* errno set by open(2) */
262 }
263
264 /* on exec, don't inherit the fd */
265 v = fcntl(tdb->fd, F_GETFD, 0);
266 fcntl(tdb->fd, F_SETFD, v | FD_CLOEXEC);
267
268 /* ensure there is only one process initialising at once */
269 if (tdb->methods->tdb_brlock(tdb, GLOBAL_LOCK, F_WRLCK, F_SETLKW, 0, 1) == -1) {
270 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to get global lock on %s: %s\n",
271 name, strerror(errno)));
272 goto fail; /* errno set by tdb_brlock */
273 }
274
275 /* we need to zero database if we are the only one with it open */
276 if ((tdb_flags & TDB_CLEAR_IF_FIRST) &&
277 (!tdb->read_only)
278#ifndef __OS2__
279 && (locked = (tdb->methods->tdb_brlock(tdb, ACTIVE_LOCK, F_WRLCK, F_SETLK, 0, 1) == 0))
280#endif
281 ) {
282 open_flags |= O_CREAT;
283 if (ftruncate(tdb->fd, 0) == -1) {
284 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
285 "failed to truncate %s: %s\n",
286 name, strerror(errno)));
287 goto fail; /* errno set by ftruncate */
288 }
289 }
290
291 errno = 0;
292 if (read(tdb->fd, &tdb->header, sizeof(tdb->header)) != sizeof(tdb->header)
293 || strcmp(tdb->header.magic_food, TDB_MAGIC_FOOD) != 0
294 || (tdb->header.version != TDB_VERSION
295 && !(rev = (tdb->header.version==TDB_BYTEREV(TDB_VERSION))))) {
296 /* its not a valid database - possibly initialise it */
297 if (!(open_flags & O_CREAT) || tdb_new_database(tdb, hash_size) == -1) {
298 if (errno == 0) {
299 errno = EIO; /* ie bad format or something */
300 }
301 goto fail;
302 }
303 rev = (tdb->flags & TDB_CONVERT);
304 }
305 vp = (unsigned char *)&tdb->header.version;
306 vertest = (((uint32_t)vp[0]) << 24) | (((uint32_t)vp[1]) << 16) |
307 (((uint32_t)vp[2]) << 8) | (uint32_t)vp[3];
308 tdb->flags |= (vertest==TDB_VERSION) ? TDB_BIGENDIAN : 0;
309 if (!rev)
310 tdb->flags &= ~TDB_CONVERT;
311 else {
312 tdb->flags |= TDB_CONVERT;
313 tdb_convert(&tdb->header, sizeof(tdb->header));
314 }
315 if (fstat(tdb->fd, &st) == -1)
316 goto fail;
317
318 if (tdb->header.rwlocks != 0) {
319 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: spinlocks no longer supported\n"));
320 goto fail;
321 }
322
323 /* Is it already in the open list? If so, fail. */
324 if (tdb_already_open(st.st_dev, st.st_ino)) {
325 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: "
326 "%s (%d,%d) is already open in this process\n",
327 name, (int)st.st_dev, (int)st.st_ino));
328 errno = EBUSY;
329 goto fail;
330 }
331
332 if (!(tdb->name = (char *)strdup(name))) {
333 errno = ENOMEM;
334 goto fail;
335 }
336
337 tdb->map_size = st.st_size;
338 tdb->device = st.st_dev;
339 tdb->inode = st.st_ino;
340 tdb_mmap(tdb);
341 if (locked) {
342#ifndef __OS2__
343 if (tdb->methods->tdb_brlock(tdb, ACTIVE_LOCK, F_UNLCK, F_SETLK, 0, 1) == -1) {
344 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: "
345 "failed to take ACTIVE_LOCK on %s: %s\n",
346 name, strerror(errno)));
347 goto fail;
348 }
349#endif
350 }
351
352 /* We always need to do this if the CLEAR_IF_FIRST flag is set, even if
353 we didn't get the initial exclusive lock as we need to let all other
354 users know we're using it. */
355
356#ifndef __OS2__
357 if (tdb_flags & TDB_CLEAR_IF_FIRST) {
358 /* leave this lock in place to indicate it's in use */
359 if (tdb->methods->tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0, 1) == -1)
360 goto fail;
361 }
362#endif
363
364 /* if needed, run recovery */
365 if (tdb_transaction_recover(tdb) == -1) {
366 goto fail;
367 }
368
369 // YD internal databases do not get global lock!
370 if (tdb->methods->tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0, 1) == -1)
371 goto fail;
372
373 internal:
374 /* Internal (memory-only) databases skip all the code above to
375 * do with disk files, and resume here by releasing their
376 * global lock and hooking into the active list. */
377#ifndef __OS2__
378 if (tdb->methods->tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0, 1) == -1)
379 goto fail;
380#endif
381 tdb->next = tdbs;
382 tdbs = tdb;
383 return tdb;
384
385 fail:
386 { int save_errno = errno;
387
388 if (!tdb)
389 return NULL;
390
391 if (tdb->map_ptr) {
392 if (tdb->flags & TDB_INTERNAL)
393 SAFE_FREE(tdb->map_ptr);
394 else
395 tdb_munmap(tdb);
396 }
397 SAFE_FREE(tdb->name);
398#ifdef __OS2__
399 DosCloseMutexSem( tdb->hGlobalLock);
400 tdb->hGlobalLock = 0;
401 DosCloseMutexSem( tdb->hActiveLock);
402 tdb->hActiveLock = 0;
403 DosCloseMutexSem( tdb->hTransactionLock);
404 tdb->hTransactionLock = 0;
405#endif
406 if (tdb->fd != -1)
407 if (close(tdb->fd) != 0)
408 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to close tdb->fd on error!\n"));
409 SAFE_FREE(tdb);
410 errno = save_errno;
411 return NULL;
412 }
413}
414
415/*
416 * Set the maximum number of dead records per hash chain
417 */
418
419void tdb_set_max_dead(struct tdb_context *tdb, int max_dead)
420{
421 tdb->max_dead_records = max_dead;
422}
423
424/**
425 * Close a database.
426 *
427 * @returns -1 for error; 0 for success.
428 **/
429int tdb_close(struct tdb_context *tdb)
430{
431 struct tdb_context **i;
432 int ret = 0;
433
434 if (tdb->transaction) {
435 tdb_transaction_cancel(tdb);
436 }
437
438 if (tdb->map_ptr) {
439 if (tdb->flags & TDB_INTERNAL)
440 SAFE_FREE(tdb->map_ptr);
441 else
442 tdb_munmap(tdb);
443 }
444 SAFE_FREE(tdb->name);
445 // YD internal databases do not have a global lock
446 if (!(tdb->flags & TDB_INTERNAL))
447 tdb->methods->tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLK, 0, 1);
448 if (tdb->fd != -1)
449 ret = close(tdb->fd);
450 SAFE_FREE(tdb->lockrecs);
451#ifdef __OS2__
452 DosCloseMutexSem( tdb->hGlobalLock);
453 tdb->hGlobalLock = 0;
454 DosCloseMutexSem( tdb->hActiveLock);
455 tdb->hActiveLock = 0;
456 DosCloseMutexSem( tdb->hTransactionLock);
457 tdb->hTransactionLock = 0;
458#endif
459
460 /* Remove from contexts list */
461 for (i = &tdbs; *i; i = &(*i)->next) {
462 if (*i == tdb) {
463 *i = tdb->next;
464 break;
465 }
466 }
467
468 memset(tdb, 0, sizeof(*tdb));
469 SAFE_FREE(tdb);
470
471 return ret;
472}
473
474/* register a loging function */
475void tdb_set_logging_function(struct tdb_context *tdb,
476 const struct tdb_logging_context *log_ctx)
477{
478 tdb->log = *log_ctx;
479}
480
481void *tdb_get_logging_private(struct tdb_context *tdb)
482{
483 return tdb->log.log_private;
484}
485
486/* reopen a tdb - this can be used after a fork to ensure that we have an independent
487 seek pointer from our parent and to re-establish locks */
488int tdb_reopen(struct tdb_context *tdb)
489{
490 struct stat st;
491
492 TDB_LOG((tdb, TDB_DEBUG_TRACE, "tdb_reopen pid %d\n", getpid()));
493
494 if (tdb->flags & TDB_INTERNAL) {
495 return 0; /* Nothing to do. */
496 }
497
498#ifdef __OS2__
499
500 DosCloseMutexSem( tdb->hGlobalLock);
501 tdb->hGlobalLock = 0;
502 DosCloseMutexSem( tdb->hActiveLock);
503 tdb->hActiveLock = 0;
504 DosCloseMutexSem( tdb->hTransactionLock);
505 tdb->hTransactionLock = 0;
506
507 if (!(tdb->flags & TDB_INTERNAL))
508 {
509 char szSem[_MAX_PATH];
510 char drive[_MAX_DRIVE], dir[_MAX_DIR];
511 char fname[_MAX_FNAME], ext[_MAX_EXT];
512 APIRET rc;
513 // extract path info
514 _splitpath( tdb->name, drive, dir, fname, ext);
515 sprintf( szSem, "\\SEM32\\TDB_GL_%s%s%s%i", dir, fname, ext, global_Sem32Add);
516 rc = DosCreateMutexSem( szSem, &tdb->hGlobalLock, 0, FALSE);
517 if (rc == ERROR_DUPLICATE_NAME)
518 rc = DosOpenMutexSem( szSem, &tdb->hGlobalLock);
519 if (rc != NO_ERROR) {
520 printf( "cannot open %s %d\n", szSem, rc);
521 errno = EINVAL;
522 goto fail;
523 }
524 TDB_LOG((tdb, TDB_DEBUG_TRACE,"tdb_reopen pid %d global handle %d\n", getpid(), tdb->hGlobalLock));
525 sprintf( szSem, "\\SEM32\\TDB_AL_%s%s%s%i", dir, fname, ext, global_Sem32Add);
526 rc = DosCreateMutexSem( szSem, &tdb->hActiveLock, 0, FALSE);
527 if (rc == ERROR_DUPLICATE_NAME)
528 rc = DosOpenMutexSem( szSem, &tdb->hActiveLock);
529 if (rc != NO_ERROR) {
530 printf( "cannot open %s %d\n", szSem, rc);
531 errno = EINVAL;
532 goto fail;
533 }
534 TDB_LOG((tdb, TDB_DEBUG_TRACE,"tdb_reopen pid %d active handle %d\n", getpid(), tdb->hActiveLock));
535 sprintf( szSem, "\\SEM32\\TDB_TL_%s%s%s%i", dir, fname, ext, global_Sem32Add);
536 rc = DosCreateMutexSem( szSem, &tdb->hTransactionLock, 0, FALSE);
537 if (rc == ERROR_DUPLICATE_NAME)
538 rc = DosOpenMutexSem( szSem, &tdb->hTransactionLock);
539 if (rc != NO_ERROR) {
540 printf( "cannot open %s %d\n", szSem, rc);
541 errno = EINVAL;
542 goto fail;
543 }
544 TDB_LOG((tdb, TDB_DEBUG_TRACE,"tdb_reopen pid %d transaction handle %d\n", getpid(), tdb->hTransactionLock));
545 }
546#endif
547
548 if (tdb->num_locks != 0 || tdb->global_lock.count) {
549 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_reopen: reopen not allowed with locks held\n"));
550 goto fail;
551 }
552
553 if (tdb->transaction != 0) {
554 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_reopen: reopen not allowed inside a transaction\n"));
555 goto fail;
556 }
557
558 if (tdb_munmap(tdb) != 0) {
559 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: munmap failed (%s)\n", strerror(errno)));
560 goto fail;
561 }
562 if (close(tdb->fd) != 0)
563 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: WARNING closing tdb->fd failed!\n"));
564 tdb->fd = open(tdb->name, tdb->open_flags & ~(O_CREAT|O_TRUNC), 0);
565 if (tdb->fd == -1) {
566 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: open failed (%s)\n", strerror(errno)));
567 goto fail;
568 }
569 if ((tdb->flags & TDB_CLEAR_IF_FIRST) &&
570 (tdb->methods->tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0, 1) == -1)) {
571 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: failed to obtain active lock\n"));
572 goto fail;
573 }
574 if (fstat(tdb->fd, &st) != 0) {
575 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: fstat failed (%s)\n", strerror(errno)));
576 goto fail;
577 }
578 if (st.st_ino != tdb->inode || st.st_dev != tdb->device) {
579 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: file dev/inode has changed!\n"));
580 goto fail;
581 }
582 tdb_mmap(tdb);
583
584 return 0;
585
586fail:
587 tdb_close(tdb);
588 return -1;
589}
590
591/* reopen all tdb's */
592int tdb_reopen_all(int parent_longlived)
593{
594 struct tdb_context *tdb;
595
596 for (tdb=tdbs; tdb; tdb = tdb->next) {
597 /*
598 * If the parent is longlived (ie. a
599 * parent daemon architecture), we know
600 * it will keep it's active lock on a
601 * tdb opened with CLEAR_IF_FIRST. Thus
602 * for child processes we don't have to
603 * add an active lock. This is essential
604 * to improve performance on systems that
605 * keep POSIX locks as a non-scalable data
606 * structure in the kernel.
607 */
608 if (parent_longlived) {
609 /* Ensure no clear-if-first. */
610 tdb->flags &= ~TDB_CLEAR_IF_FIRST;
611 }
612
613 if (tdb_reopen(tdb) != 0)
614 return -1;
615 }
616
617 return 0;
618}
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