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

Last change on this file was 916, checked in by Silvan Scherrer, 9 years ago

Samba Server: update trunk to version 3.6.25, fix some more crlf issues
File size: 17.6 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#ifdef __OS2__
193 open_flags |= O_BINARY;
194#endif
195 tdb->open_flags = open_flags;
196 if (log_ctx) {
197 tdb->log = *log_ctx;
198 } else {
199 tdb->log.log_fn = null_log_fn;
200 tdb->log.log_private = NULL;
201 }
202
203 if (name == NULL && (tdb_flags & TDB_INTERNAL)) {
204 name = "__TDB_INTERNAL__";
205 }
206
207 if (name == NULL) {
208 tdb->name = discard_const_p(char, "__NULL__");
209 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: called with name == NULL\n"));
210 tdb->name = NULL;
211 errno = EINVAL;
212 goto fail;
213 }
214
215 /* now make a copy of the name, as the caller memory might went away */
216 if (!(tdb->name = (char *)strdup(name))) {
217 /*
218 * set the name as the given string, so that tdb_name() will
219 * work in case of an error.
220 */
221 tdb->name = discard_const_p(char, name);
222 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: can't strdup(%s)\n",
223 name));
224 tdb->name = NULL;
225 errno = ENOMEM;
226 goto fail;
227 }
228
229 if (hash_fn) {
230 tdb->hash_fn = hash_fn;
231 hash_alg = "the user defined";
232 } else {
233 /* This controls what we use when creating a tdb. */
234 if (tdb->flags & TDB_INCOMPATIBLE_HASH) {
235 tdb->hash_fn = tdb_jenkins_hash;
236 } else {
237 tdb->hash_fn = tdb_old_hash;
238 }
239 hash_alg = "either default";
240 }
241
242 /* cache the page size */
243 tdb->page_size = getpagesize();
244 if (tdb->page_size <= 0) {
245 tdb->page_size = 0x2000;
246 }
247
248 tdb->max_dead_records = (tdb_flags & TDB_VOLATILE) ? 5 : 0;
249
250 if ((open_flags & O_ACCMODE) == O_WRONLY) {
251 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: can't open tdb %s write-only\n",
252 name));
253 errno = EINVAL;
254 goto fail;
255 }
256
257 if (hash_size == 0)
258 hash_size = DEFAULT_HASH_SIZE;
259 if ((open_flags & O_ACCMODE) == O_RDONLY) {
260 tdb->read_only = 1;
261 /* read only databases don't do locking or clear if first */
262 tdb->flags |= TDB_NOLOCK;
263 tdb->flags &= ~TDB_CLEAR_IF_FIRST;
264 }
265
266 if ((tdb->flags & TDB_ALLOW_NESTING) &&
267 (tdb->flags & TDB_DISALLOW_NESTING)) {
268 tdb->ecode = TDB_ERR_NESTING;
269 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
270 "allow_nesting and disallow_nesting are not allowed together!"));
271 errno = EINVAL;
272 goto fail;
273 }
274
275 if (getenv("TDB_NO_FSYNC")) {
276 tdb->flags |= TDB_NOSYNC;
277 }
278
279 /*
280 * TDB_ALLOW_NESTING is the default behavior.
281 * Note: this may change in future versions!
282 */
283 if (!(tdb->flags & TDB_DISALLOW_NESTING)) {
284 tdb->flags |= TDB_ALLOW_NESTING;
285 }
286
287 /* internal databases don't mmap or lock, and start off cleared */
288 if (tdb->flags & TDB_INTERNAL) {
289 tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);
290 tdb->flags &= ~TDB_CLEAR_IF_FIRST;
291 if (tdb_new_database(tdb, hash_size) != 0) {
292 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: tdb_new_database failed!"));
293 goto fail;
294 }
295 goto internal;
296 }
297
298 if ((tdb->fd = open(name, open_flags, mode)) == -1) {
299 TDB_LOG((tdb, TDB_DEBUG_WARNING, "tdb_open_ex: could not open file %s: %s\n",
300 name, strerror(errno)));
301 goto fail; /* errno set by open(2) */
302 }
303
304 /* on exec, don't inherit the fd */
305 v = fcntl(tdb->fd, F_GETFD, 0);
306 fcntl(tdb->fd, F_SETFD, v | FD_CLOEXEC);
307
308 /* ensure there is only one process initialising at once */
309 if (tdb_nest_lock(tdb, OPEN_LOCK, F_WRLCK, TDB_LOCK_WAIT) == -1) {
310 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to get open lock on %s: %s\n",
311 name, strerror(errno)));
312 goto fail; /* errno set by tdb_brlock */
313 }
314
315 /* we need to zero database if we are the only one with it open */
316 if ((tdb_flags & TDB_CLEAR_IF_FIRST) &&
317 (!tdb->read_only) &&
318 (locked = (tdb_nest_lock(tdb, ACTIVE_LOCK, F_WRLCK, TDB_LOCK_NOWAIT|TDB_LOCK_PROBE) == 0))) {
319 int ret;
320 ret = tdb_brlock(tdb, F_WRLCK, FREELIST_TOP, 0,
321 TDB_LOCK_WAIT);
322 if (ret == -1) {
323 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
324 "tdb_brlock failed for %s: %s\n",
325 name, strerror(errno)));
326 goto fail;
327 }
328 ret = tdb_new_database(tdb, hash_size);
329 if (ret == -1) {
330 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
331 "tdb_new_database failed for %s: %s\n",
332 name, strerror(errno)));
333 tdb_unlockall(tdb);
334 goto fail;
335 }
336 ret = tdb_brunlock(tdb, F_WRLCK, FREELIST_TOP, 0);
337 if (ret == -1) {
338 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
339 "tdb_unlockall failed for %s: %s\n",
340 name, strerror(errno)));
341 goto fail;
342 }
343 ret = lseek(tdb->fd, 0, SEEK_SET);
344 if (ret == -1) {
345 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
346 "lseek failed for %s: %s\n",
347 name, strerror(errno)));
348 goto fail;
349 }
350 }
351
352 errno = 0;
353 if (read(tdb->fd, &tdb->header, sizeof(tdb->header)) != sizeof(tdb->header)
354 || strcmp(tdb->header.magic_food, TDB_MAGIC_FOOD) != 0) {
355 if (!(open_flags & O_CREAT) || tdb_new_database(tdb, hash_size) == -1) {
356 if (errno == 0) {
357 errno = EIO; /* ie bad format or something */
358 }
359 goto fail;
360 }
361 rev = (tdb->flags & TDB_CONVERT);
362 } else if (tdb->header.version != TDB_VERSION
363 && !(rev = (tdb->header.version==TDB_BYTEREV(TDB_VERSION)))) {
364 /* wrong version */
365 errno = EIO;
366 goto fail;
367 }
368 vp = (unsigned char *)&tdb->header.version;
369 vertest = (((uint32_t)vp[0]) << 24) | (((uint32_t)vp[1]) << 16) |
370 (((uint32_t)vp[2]) << 8) | (uint32_t)vp[3];
371 tdb->flags |= (vertest==TDB_VERSION) ? TDB_BIGENDIAN : 0;
372 if (!rev)
373 tdb->flags &= ~TDB_CONVERT;
374 else {
375 tdb->flags |= TDB_CONVERT;
376 tdb_convert(&tdb->header, sizeof(tdb->header));
377 }
378 if (fstat(tdb->fd, &st) == -1)
379 goto fail;
380
381 if (tdb->header.rwlocks != 0 &&
382 tdb->header.rwlocks != TDB_HASH_RWLOCK_MAGIC) {
383 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: spinlocks no longer supported\n"));
384 goto fail;
385 }
386
387 if ((tdb->header.magic1_hash == 0) && (tdb->header.magic2_hash == 0)) {
388 /* older TDB without magic hash references */
389 tdb->hash_fn = tdb_old_hash;
390 } else if (!check_header_hash(tdb, !hash_fn, &magic1, &magic2)) {
391 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
392 "%s was not created with %s hash function we are using\n"
393 "magic1_hash[0x%08X %s 0x%08X] "
394 "magic2_hash[0x%08X %s 0x%08X]\n",
395 name, hash_alg,
396 tdb->header.magic1_hash,
397 (tdb->header.magic1_hash == magic1) ? "==" : "!=",
398 magic1,
399 tdb->header.magic2_hash,
400 (tdb->header.magic2_hash == magic2) ? "==" : "!=",
401 magic2));
402 errno = EINVAL;
403 goto fail;
404 }
405
406 /* Is it already in the open list? If so, fail. */
407 if (tdb_already_open(st.st_dev, st.st_ino)) {
408 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: "
409 "%s (%d,%d) is already open in this process\n",
410 name, (int)st.st_dev, (int)st.st_ino));
411 errno = EBUSY;
412 goto fail;
413 }
414
415 tdb->map_size = st.st_size;
416 tdb->device = st.st_dev;
417 tdb->inode = st.st_ino;
418 tdb_mmap(tdb);
419 if (locked) {
420 if (tdb_nest_unlock(tdb, ACTIVE_LOCK, F_WRLCK, false) == -1) {
421 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: "
422 "failed to release ACTIVE_LOCK on %s: %s\n",
423 name, strerror(errno)));
424 goto fail;
425 }
426
427 }
428
429 /* We always need to do this if the CLEAR_IF_FIRST flag is set, even if
430 we didn't get the initial exclusive lock as we need to let all other
431 users know we're using it. */
432
433 if (tdb_flags & TDB_CLEAR_IF_FIRST) {
434 /* leave this lock in place to indicate it's in use */
435 if (tdb_nest_lock(tdb, ACTIVE_LOCK, F_RDLCK, TDB_LOCK_WAIT) == -1) {
436 goto fail;
437 }
438 }
439
440 /* if needed, run recovery */
441 if (tdb_transaction_recover(tdb) == -1) {
442 goto fail;
443 }
444
445#ifdef TDB_TRACE
446 {
447 char tracefile[strlen(name) + 32];
448
449 snprintf(tracefile, sizeof(tracefile),
450 "%s.trace.%li", name, (long)getpid());
451 tdb->tracefd = open(tracefile, O_WRONLY|O_CREAT|O_EXCL, 0600);
452 if (tdb->tracefd >= 0) {
453 tdb_enable_seqnum(tdb);
454 tdb_trace_open(tdb, "tdb_open", hash_size, tdb_flags,
455 open_flags);
456 } else
457 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to open trace file %s!\n", tracefile));
458 }
459#endif
460
461 internal:
462 /* Internal (memory-only) databases skip all the code above to
463 * do with disk files, and resume here by releasing their
464 * open lock and hooking into the active list. */
465 if (tdb_nest_unlock(tdb, OPEN_LOCK, F_WRLCK, false) == -1) {
466 goto fail;
467 }
468 tdb->next = tdbs;
469 tdbs = tdb;
470 return tdb;
471
472 fail:
473 { int save_errno = errno;
474
475 if (!tdb)
476 return NULL;
477
478#ifdef TDB_TRACE
479 close(tdb->tracefd);
480#endif
481 if (tdb->map_ptr) {
482 if (tdb->flags & TDB_INTERNAL)
483 SAFE_FREE(tdb->map_ptr);
484 else
485 tdb_munmap(tdb);
486 }
487 if (tdb->fd != -1)
488 if (close(tdb->fd) != 0)
489 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to close tdb->fd on error!\n"));
490 SAFE_FREE(tdb->lockrecs);
491 SAFE_FREE(tdb->name);
492 SAFE_FREE(tdb);
493 errno = save_errno;
494 return NULL;
495 }
496}
497
498/*
499 * Set the maximum number of dead records per hash chain
500 */
501
502_PUBLIC_ void tdb_set_max_dead(struct tdb_context *tdb, int max_dead)
503{
504 tdb->max_dead_records = max_dead;
505}
506
507/**
508 * Close a database.
509 *
510 * @returns -1 for error; 0 for success.
511 **/
512_PUBLIC_ int tdb_close(struct tdb_context *tdb)
513{
514 struct tdb_context **i;
515 int ret = 0;
516
517 if (tdb->transaction) {
518 tdb_transaction_cancel(tdb);
519 }
520 tdb_trace(tdb, "tdb_close");
521
522 if (tdb->map_ptr) {
523 if (tdb->flags & TDB_INTERNAL)
524 SAFE_FREE(tdb->map_ptr);
525 else
526 tdb_munmap(tdb);
527 }
528 SAFE_FREE(tdb->name);
529 if (tdb->fd != -1) {
530 ret = close(tdb->fd);
531 tdb->fd = -1;
532 }
533 SAFE_FREE(tdb->lockrecs);
534
535 /* Remove from contexts list */
536 for (i = &tdbs; *i; i = &(*i)->next) {
537 if (*i == tdb) {
538 *i = tdb->next;
539 break;
540 }
541 }
542
543#ifdef TDB_TRACE
544 close(tdb->tracefd);
545#endif
546 memset(tdb, 0, sizeof(*tdb));
547 SAFE_FREE(tdb);
548
549 return ret;
550}
551
552/* register a loging function */
553_PUBLIC_ void tdb_set_logging_function(struct tdb_context *tdb,
554 const struct tdb_logging_context *log_ctx)
555{
556 tdb->log = *log_ctx;
557}
558
559_PUBLIC_ void *tdb_get_logging_private(struct tdb_context *tdb)
560{
561 return tdb->log.log_private;
562}
563
564static int tdb_reopen_internal(struct tdb_context *tdb, bool active_lock)
565{
566#if !defined(LIBREPLACE_PREAD_NOT_REPLACED) || \
567 !defined(LIBREPLACE_PWRITE_NOT_REPLACED)
568 struct stat st;
569#endif
570
571 if (tdb->flags & TDB_INTERNAL) {
572 return 0; /* Nothing to do. */
573 }
574
575 if (tdb_have_extra_locks(tdb)) {
576 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_reopen: reopen not allowed with locks held\n"));
577 goto fail;
578 }
579
580 if (tdb->transaction != 0) {
581 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_reopen: reopen not allowed inside a transaction\n"));
582 goto fail;
583 }
584
585/* If we have real pread & pwrite, we can skip reopen. */
586#if !defined(LIBREPLACE_PREAD_NOT_REPLACED) || \
587 !defined(LIBREPLACE_PWRITE_NOT_REPLACED)
588 if (tdb_munmap(tdb) != 0) {
589 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: munmap failed (%s)\n", strerror(errno)));
590 goto fail;
591 }
592 if (close(tdb->fd) != 0)
593 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: WARNING closing tdb->fd failed!\n"));
594 tdb->fd = open(tdb->name, tdb->open_flags & ~(O_CREAT|O_TRUNC), 0);
595 if (tdb->fd == -1) {
596 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: open failed (%s)\n", strerror(errno)));
597 goto fail;
598 }
599 if (fstat(tdb->fd, &st) != 0) {
600 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: fstat failed (%s)\n", strerror(errno)));
601 goto fail;
602 }
603 if (st.st_ino != tdb->inode || st.st_dev != tdb->device) {
604 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: file dev/inode has changed!\n"));
605 goto fail;
606 }
607 tdb_mmap(tdb);
608#endif /* fake pread or pwrite */
609
610 /* We may still think we hold the active lock. */
611 tdb->num_lockrecs = 0;
612 SAFE_FREE(tdb->lockrecs);
613
614 if (active_lock && tdb_nest_lock(tdb, ACTIVE_LOCK, F_RDLCK, TDB_LOCK_WAIT) == -1) {
615 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: failed to obtain active lock\n"));
616 goto fail;
617 }
618
619 return 0;
620
621fail:
622 tdb_close(tdb);
623 return -1;
624}
625
626/* reopen a tdb - this can be used after a fork to ensure that we have an independent
627 seek pointer from our parent and to re-establish locks */
628_PUBLIC_ int tdb_reopen(struct tdb_context *tdb)
629{
630 return tdb_reopen_internal(tdb, tdb->flags & TDB_CLEAR_IF_FIRST);
631}
632
633/* reopen all tdb's */
634_PUBLIC_ int tdb_reopen_all(int parent_longlived)
635{
636 struct tdb_context *tdb;
637
638 for (tdb=tdbs; tdb; tdb = tdb->next) {
639 bool active_lock = (tdb->flags & TDB_CLEAR_IF_FIRST);
640
641 /*
642 * If the parent is longlived (ie. a
643 * parent daemon architecture), we know
644 * it will keep it's active lock on a
645 * tdb opened with CLEAR_IF_FIRST. Thus
646 * for child processes we don't have to
647 * add an active lock. This is essential
648 * to improve performance on systems that
649 * keep POSIX locks as a non-scalable data
650 * structure in the kernel.
651 */
652 if (parent_longlived) {
653 /* Ensure no clear-if-first. */
654 active_lock = false;
655 }
656
657 if (tdb_reopen_internal(tdb, active_lock) != 0)
658 return -1;
659 }
660
661 return 0;
662}
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