tdb2: remove double-open detection for TDB1 databases.
[ccan] / ccan / tdb2 / open.c
1  /*
2    Trivial Database 2: opening and closing TDBs
3    Copyright (C) Rusty Russell 2010
4
5    This library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Lesser General Public
7    License as published by the Free Software Foundation; either
8    version 3 of the License, or (at your option) any later version.
9
10    This library is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    Lesser General Public License for more details.
14
15    You should have received a copy of the GNU Lesser General Public
16    License along with this library; if not, see <http://www.gnu.org/licenses/>.
17 */
18 #include "private.h"
19 #include <ccan/hash/hash.h>
20 #include <assert.h>
21
22 /* all tdbs, to detect double-opens (fcntl file don't nest!) */
23 static struct tdb_context *tdbs = NULL;
24
25 static struct tdb_file *find_file(dev_t device, ino_t ino)
26 {
27         struct tdb_context *i;
28
29         for (i = tdbs; i; i = i->next) {
30                 if (i->file->device == device && i->file->inode == ino) {
31                         i->file->refcnt++;
32                         return i->file;
33                 }
34         }
35         return NULL;
36 }
37
38 static bool read_all(int fd, void *buf, size_t len)
39 {
40         while (len) {
41                 ssize_t ret;
42                 ret = read(fd, buf, len);
43                 if (ret < 0)
44                         return false;
45                 if (ret == 0) {
46                         /* ETOOSHORT? */
47                         errno = EWOULDBLOCK;
48                         return false;
49                 }
50                 buf = (char *)buf + ret;
51                 len -= ret;
52         }
53         return true;
54 }
55
56 static uint64_t random_number(struct tdb_context *tdb)
57 {
58         int fd;
59         uint64_t ret = 0;
60         struct timeval now;
61
62         fd = open("/dev/urandom", O_RDONLY);
63         if (fd >= 0) {
64                 if (read_all(fd, &ret, sizeof(ret))) {
65                         close(fd);
66                         return ret;
67                 }
68                 close(fd);
69         }
70         /* FIXME: Untested!  Based on Wikipedia protocol description! */
71         fd = open("/dev/egd-pool", O_RDWR);
72         if (fd >= 0) {
73                 /* Command is 1, next byte is size we want to read. */
74                 char cmd[2] = { 1, sizeof(uint64_t) };
75                 if (write(fd, cmd, sizeof(cmd)) == sizeof(cmd)) {
76                         char reply[1 + sizeof(uint64_t)];
77                         int r = read(fd, reply, sizeof(reply));
78                         if (r > 1) {
79                                 /* Copy at least some bytes. */
80                                 memcpy(&ret, reply+1, r - 1);
81                                 if (reply[0] == sizeof(uint64_t)
82                                     && r == sizeof(reply)) {
83                                         close(fd);
84                                         return ret;
85                                 }
86                         }
87                 }
88                 close(fd);
89         }
90
91         /* Fallback: pid and time. */
92         gettimeofday(&now, NULL);
93         ret = getpid() * 100132289ULL + now.tv_sec * 1000000ULL + now.tv_usec;
94         tdb_logerr(tdb, TDB_SUCCESS, TDB_LOG_WARNING,
95                    "tdb_open: random from getpid and time");
96         return ret;
97 }
98
99 struct new_database {
100         struct tdb_header hdr;
101         struct tdb_freetable ftable;
102 };
103
104 /* initialise a new database */
105 static enum TDB_ERROR tdb_new_database(struct tdb_context *tdb,
106                                        struct tdb_attribute_seed *seed,
107                                        struct tdb_header *hdr)
108 {
109         /* We make it up in memory, then write it out if not internal */
110         struct new_database newdb;
111         unsigned int magic_len;
112         ssize_t rlen;
113         enum TDB_ERROR ecode;
114
115         /* Fill in the header */
116         newdb.hdr.version = TDB_VERSION;
117         if (seed)
118                 newdb.hdr.hash_seed = seed->seed;
119         else
120                 newdb.hdr.hash_seed = random_number(tdb);
121         newdb.hdr.hash_test = TDB_HASH_MAGIC;
122         newdb.hdr.hash_test = tdb->hash_fn(&newdb.hdr.hash_test,
123                                            sizeof(newdb.hdr.hash_test),
124                                            newdb.hdr.hash_seed,
125                                            tdb->hash_data);
126         newdb.hdr.recovery = 0;
127         newdb.hdr.features_used = newdb.hdr.features_offered = TDB_FEATURE_MASK;
128         newdb.hdr.seqnum = 0;
129         memset(newdb.hdr.reserved, 0, sizeof(newdb.hdr.reserved));
130         /* Initial hashes are empty. */
131         memset(newdb.hdr.hashtable, 0, sizeof(newdb.hdr.hashtable));
132
133         /* Free is empty. */
134         newdb.hdr.free_table = offsetof(struct new_database, ftable);
135         memset(&newdb.ftable, 0, sizeof(newdb.ftable));
136         ecode = set_header(NULL, &newdb.ftable.hdr, TDB_FTABLE_MAGIC, 0,
137                            sizeof(newdb.ftable) - sizeof(newdb.ftable.hdr),
138                            sizeof(newdb.ftable) - sizeof(newdb.ftable.hdr),
139                            0);
140         if (ecode != TDB_SUCCESS) {
141                 return ecode;
142         }
143
144         /* Magic food */
145         memset(newdb.hdr.magic_food, 0, sizeof(newdb.hdr.magic_food));
146         strcpy(newdb.hdr.magic_food, TDB_MAGIC_FOOD);
147
148         /* This creates an endian-converted database, as if read from disk */
149         magic_len = sizeof(newdb.hdr.magic_food);
150         tdb_convert(tdb,
151                     (char *)&newdb.hdr + magic_len, sizeof(newdb) - magic_len);
152
153         *hdr = newdb.hdr;
154
155         if (tdb->flags & TDB_INTERNAL) {
156                 tdb->file->map_size = sizeof(newdb);
157                 tdb->file->map_ptr = malloc(tdb->file->map_size);
158                 if (!tdb->file->map_ptr) {
159                         return tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
160                                           "tdb_new_database:"
161                                           " failed to allocate");
162                 }
163                 memcpy(tdb->file->map_ptr, &newdb, tdb->file->map_size);
164                 return TDB_SUCCESS;
165         }
166         if (lseek(tdb->file->fd, 0, SEEK_SET) == -1) {
167                 return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
168                                   "tdb_new_database:"
169                                   " failed to seek: %s", strerror(errno));
170         }
171
172         if (ftruncate(tdb->file->fd, 0) == -1) {
173                 return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
174                                   "tdb_new_database:"
175                                   " failed to truncate: %s", strerror(errno));
176         }
177
178         rlen = write(tdb->file->fd, &newdb, sizeof(newdb));
179         if (rlen != sizeof(newdb)) {
180                 if (rlen >= 0)
181                         errno = ENOSPC;
182                 return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
183                                   "tdb_new_database: %zi writing header: %s",
184                                   rlen, strerror(errno));
185         }
186         return TDB_SUCCESS;
187 }
188
189 static enum TDB_ERROR tdb_new_file(struct tdb_context *tdb)
190 {
191         tdb->file = malloc(sizeof(*tdb->file));
192         if (!tdb->file)
193                 return tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
194                                   "tdb_open: cannot alloc tdb_file structure");
195         tdb->file->num_lockrecs = 0;
196         tdb->file->lockrecs = NULL;
197         tdb->file->allrecord_lock.count = 0;
198         tdb->file->refcnt = 1;
199         return TDB_SUCCESS;
200 }
201
202 enum TDB_ERROR tdb_set_attribute(struct tdb_context *tdb,
203                                  const union tdb_attribute *attr)
204 {
205         switch (attr->base.attr) {
206         case TDB_ATTRIBUTE_LOG:
207                 tdb->log_fn = attr->log.fn;
208                 tdb->log_data = attr->log.data;
209                 break;
210         case TDB_ATTRIBUTE_HASH:
211         case TDB_ATTRIBUTE_SEED:
212         case TDB_ATTRIBUTE_OPENHOOK:
213                 return tdb->last_error
214                         = tdb_logerr(tdb, TDB_ERR_EINVAL,
215                                      TDB_LOG_USE_ERROR,
216                                      "tdb_set_attribute:"
217                                      " cannot set %s after opening",
218                                      attr->base.attr == TDB_ATTRIBUTE_HASH
219                                      ? "TDB_ATTRIBUTE_HASH"
220                                      : attr->base.attr == TDB_ATTRIBUTE_SEED
221                                      ? "TDB_ATTRIBUTE_SEED"
222                                      : "TDB_ATTRIBUTE_OPENHOOK");
223         case TDB_ATTRIBUTE_STATS:
224                 return tdb->last_error
225                         = tdb_logerr(tdb, TDB_ERR_EINVAL,
226                                      TDB_LOG_USE_ERROR,
227                                      "tdb_set_attribute:"
228                                      " cannot set TDB_ATTRIBUTE_STATS");
229         case TDB_ATTRIBUTE_FLOCK:
230                 tdb->lock_fn = attr->flock.lock;
231                 tdb->unlock_fn = attr->flock.unlock;
232                 tdb->lock_data = attr->flock.data;
233                 break;
234         default:
235                 return tdb->last_error
236                         = tdb_logerr(tdb, TDB_ERR_EINVAL,
237                                      TDB_LOG_USE_ERROR,
238                                      "tdb_set_attribute:"
239                                      " unknown attribute type %u",
240                                      attr->base.attr);
241         }
242         return TDB_SUCCESS;
243 }
244
245 static uint64_t jenkins_hash(const void *key, size_t length, uint64_t seed,
246                              void *unused)
247 {
248         uint64_t ret;
249         /* hash64_stable assumes lower bits are more important; they are a
250          * slightly better hash.  We use the upper bits first, so swap them. */
251         ret = hash64_stable((const unsigned char *)key, length, seed);
252         return (ret >> 32) | (ret << 32);
253 }
254
255 enum TDB_ERROR tdb_get_attribute(struct tdb_context *tdb,
256                                  union tdb_attribute *attr)
257 {
258         switch (attr->base.attr) {
259         case TDB_ATTRIBUTE_LOG:
260                 if (!tdb->log_fn)
261                         return tdb->last_error = TDB_ERR_NOEXIST;
262                 attr->log.fn = tdb->log_fn;
263                 attr->log.data = tdb->log_data;
264                 break;
265         case TDB_ATTRIBUTE_HASH:
266                 attr->hash.fn = tdb->hash_fn;
267                 attr->hash.data = tdb->hash_data;
268                 break;
269         case TDB_ATTRIBUTE_SEED:
270                 attr->seed.seed = tdb->hash_seed;
271                 break;
272         case TDB_ATTRIBUTE_OPENHOOK:
273                 if (!tdb->openhook)
274                         return tdb->last_error = TDB_ERR_NOEXIST;
275                 attr->openhook.fn = tdb->openhook;
276                 attr->openhook.data = tdb->openhook_data;
277                 break;
278         case TDB_ATTRIBUTE_STATS: {
279                 size_t size = attr->stats.size;
280                 if (size > tdb->stats.size)
281                         size = tdb->stats.size;
282                 memcpy(&attr->stats, &tdb->stats, size);
283                 break;
284         }
285         case TDB_ATTRIBUTE_FLOCK:
286                 attr->flock.lock = tdb->lock_fn;
287                 attr->flock.unlock = tdb->unlock_fn;
288                 attr->flock.data = tdb->lock_data;
289                 break;
290         default:
291                 return tdb->last_error
292                         = tdb_logerr(tdb, TDB_ERR_EINVAL,
293                                      TDB_LOG_USE_ERROR,
294                                      "tdb_get_attribute:"
295                                      " unknown attribute type %u",
296                                      attr->base.attr);
297         }
298         attr->base.next = NULL;
299         return TDB_SUCCESS;
300 }
301
302 void tdb_unset_attribute(struct tdb_context *tdb,
303                          enum tdb_attribute_type type)
304 {
305         switch (type) {
306         case TDB_ATTRIBUTE_LOG:
307                 tdb->log_fn = NULL;
308                 break;
309         case TDB_ATTRIBUTE_OPENHOOK:
310                 tdb->openhook = NULL;
311                 break;
312         case TDB_ATTRIBUTE_HASH:
313         case TDB_ATTRIBUTE_SEED:
314                 tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
315                            "tdb_unset_attribute: cannot unset %s after opening",
316                            type == TDB_ATTRIBUTE_HASH
317                            ? "TDB_ATTRIBUTE_HASH"
318                            : "TDB_ATTRIBUTE_SEED");
319                 break;
320         case TDB_ATTRIBUTE_STATS:
321                 tdb_logerr(tdb, TDB_ERR_EINVAL,
322                            TDB_LOG_USE_ERROR,
323                            "tdb_unset_attribute:"
324                            "cannot unset TDB_ATTRIBUTE_STATS");
325                 break;
326         case TDB_ATTRIBUTE_FLOCK:
327                 tdb->lock_fn = tdb_fcntl_lock;
328                 tdb->unlock_fn = tdb_fcntl_unlock;
329                 break;
330         default:
331                 tdb_logerr(tdb, TDB_ERR_EINVAL,
332                            TDB_LOG_USE_ERROR,
333                            "tdb_unset_attribute: unknown attribute type %u",
334                            type);
335         }
336 }
337
338 struct tdb_context *tdb_open(const char *name, int tdb_flags,
339                              int open_flags, mode_t mode,
340                              union tdb_attribute *attr)
341 {
342         struct tdb_context *tdb;
343         struct stat st;
344         int saved_errno = 0;
345         uint64_t hash_test;
346         unsigned v;
347         ssize_t rlen;
348         struct tdb_header hdr;
349         struct tdb_attribute_seed *seed = NULL;
350         tdb_bool_err berr;
351         enum TDB_ERROR ecode;
352         int openlock;
353
354         tdb = malloc(sizeof(*tdb) + (name ? strlen(name) + 1 : 0));
355         if (!tdb) {
356                 /* Can't log this */
357                 errno = ENOMEM;
358                 return NULL;
359         }
360         /* Set name immediately for logging functions. */
361         if (name) {
362                 tdb->name = strcpy((char *)(tdb + 1), name);
363         } else {
364                 tdb->name = NULL;
365         }
366         tdb->flags = tdb_flags;
367         tdb->log_fn = NULL;
368         tdb->open_flags = open_flags;
369         tdb->last_error = TDB_SUCCESS;
370         tdb->file = NULL;
371         tdb->openhook = NULL;
372         tdb->lock_fn = tdb_fcntl_lock;
373         tdb->unlock_fn = tdb_fcntl_unlock;
374         tdb->hash_fn = jenkins_hash;
375         memset(&tdb->stats, 0, sizeof(tdb->stats));
376         tdb->stats.base.attr = TDB_ATTRIBUTE_STATS;
377         tdb->stats.size = sizeof(tdb->stats);
378         tdb_io_init(tdb);
379         tdb->tdb2.direct_access = 0;
380         tdb->tdb2.transaction = NULL;
381         tdb->tdb2.access = NULL;
382
383         while (attr) {
384                 switch (attr->base.attr) {
385                 case TDB_ATTRIBUTE_HASH:
386                         tdb->hash_fn = attr->hash.fn;
387                         tdb->hash_data = attr->hash.data;
388                         break;
389                 case TDB_ATTRIBUTE_SEED:
390                         seed = &attr->seed;
391                         break;
392                 case TDB_ATTRIBUTE_OPENHOOK:
393                         tdb->openhook = attr->openhook.fn;
394                         tdb->openhook_data = attr->openhook.data;
395                         break;
396                 default:
397                         /* These are set as normal. */
398                         ecode = tdb_set_attribute(tdb, attr);
399                         if (ecode != TDB_SUCCESS)
400                                 goto fail;
401                 }
402                 attr = attr->base.next;
403         }
404
405         if (tdb_flags & ~(TDB_INTERNAL | TDB_NOLOCK | TDB_NOMMAP | TDB_CONVERT
406                           | TDB_NOSYNC | TDB_SEQNUM | TDB_ALLOW_NESTING
407                           | TDB_RDONLY)) {
408                 ecode = tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
409                                    "tdb_open: unknown flags %u", tdb_flags);
410                 goto fail;
411         }
412
413         if ((open_flags & O_ACCMODE) == O_WRONLY) {
414                 ecode = tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
415                                    "tdb_open: can't open tdb %s write-only",
416                                    name);
417                 goto fail;
418         }
419
420         if ((open_flags & O_ACCMODE) == O_RDONLY) {
421                 openlock = F_RDLCK;
422                 tdb->flags |= TDB_RDONLY;
423         } else {
424                 if (tdb_flags & TDB_RDONLY) {
425                         ecode = tdb_logerr(tdb, TDB_ERR_EINVAL,
426                                            TDB_LOG_USE_ERROR,
427                                            "tdb_open: can't use TDB_RDONLY"
428                                            " without O_RDONLY");
429                         goto fail;
430                 }
431                 openlock = F_WRLCK;
432         }
433
434         /* internal databases don't need any of the rest. */
435         if (tdb->flags & TDB_INTERNAL) {
436                 tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);
437                 ecode = tdb_new_file(tdb);
438                 if (ecode != TDB_SUCCESS) {
439                         goto fail;
440                 }
441                 tdb->file->fd = -1;
442                 ecode = tdb_new_database(tdb, seed, &hdr);
443                 if (ecode != TDB_SUCCESS) {
444                         goto fail;
445                 }
446                 tdb_convert(tdb, &hdr.hash_seed, sizeof(hdr.hash_seed));
447                 tdb->hash_seed = hdr.hash_seed;
448                 tdb_ftable_init(tdb);
449                 return tdb;
450         }
451
452         if (stat(name, &st) != -1)
453                 tdb->file = find_file(st.st_dev, st.st_ino);
454
455         if (!tdb->file) {
456                 int fd;
457
458                 if ((fd = open(name, open_flags, mode)) == -1) {
459                         /* errno set by open(2) */
460                         saved_errno = errno;
461                         tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
462                                    "tdb_open: could not open file %s: %s",
463                                    name, strerror(errno));
464                         goto fail_errno;
465                 }
466
467                 /* on exec, don't inherit the fd */
468                 v = fcntl(fd, F_GETFD, 0);
469                 fcntl(fd, F_SETFD, v | FD_CLOEXEC);
470
471                 if (fstat(fd, &st) == -1) {
472                         saved_errno = errno;
473                         tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
474                                    "tdb_open: could not stat open %s: %s",
475                                    name, strerror(errno));
476                         close(fd);
477                         goto fail_errno;
478                 }
479
480                 ecode = tdb_new_file(tdb);
481                 if (ecode != TDB_SUCCESS) {
482                         close(fd);
483                         goto fail;
484                 }
485
486                 tdb->file->fd = fd;
487                 tdb->file->device = st.st_dev;
488                 tdb->file->inode = st.st_ino;
489                 tdb->file->map_ptr = NULL;
490                 tdb->file->map_size = sizeof(struct tdb_header);
491         }
492
493         /* ensure there is only one process initialising at once */
494         ecode = tdb_lock_open(tdb, openlock, TDB_LOCK_WAIT|TDB_LOCK_NOCHECK);
495         if (ecode != TDB_SUCCESS) {
496                 saved_errno = errno;
497                 goto fail_errno;
498         }
499
500         /* call their open hook if they gave us one. */
501         if (tdb->openhook) {
502                 ecode = tdb->openhook(tdb->file->fd, tdb->openhook_data);
503                 if (ecode != TDB_SUCCESS) {
504                         tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
505                                    "tdb_open: open hook failed");
506                         goto fail;
507                 }
508                 open_flags |= O_CREAT;
509         }
510
511         /* If they used O_TRUNC, read will return 0. */
512         rlen = pread(tdb->file->fd, &hdr, sizeof(hdr), 0);
513         if (rlen == 0 && (open_flags & O_CREAT)) {
514                 ecode = tdb_new_database(tdb, seed, &hdr);
515                 if (ecode != TDB_SUCCESS) {
516                         goto fail;
517                 }
518         } else if (rlen < 0) {
519                 ecode = tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
520                                    "tdb_open: error %s reading %s",
521                                    strerror(errno), name);
522                 goto fail;
523         } else if (rlen < sizeof(hdr)
524                    || strcmp(hdr.magic_food, TDB_MAGIC_FOOD) != 0) {
525                 ecode = tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
526                                    "tdb_open: %s is not a tdb file", name);
527                 goto fail;
528         }
529
530         if (hdr.version != TDB_VERSION) {
531                 if (hdr.version == bswap_64(TDB_VERSION))
532                         tdb->flags |= TDB_CONVERT;
533                 else {
534                         /* wrong version */
535                         ecode = tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
536                                            "tdb_open:"
537                                            " %s is unknown version 0x%llx",
538                                            name, (long long)hdr.version);
539                         goto fail;
540                 }
541         } else if (tdb->flags & TDB_CONVERT) {
542                 ecode = tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
543                                    "tdb_open:"
544                                    " %s does not need TDB_CONVERT",
545                                    name);
546                 goto fail;
547         }
548
549         tdb_convert(tdb, &hdr, sizeof(hdr));
550         tdb->hash_seed = hdr.hash_seed;
551         hash_test = TDB_HASH_MAGIC;
552         hash_test = tdb_hash(tdb, &hash_test, sizeof(hash_test));
553         if (hdr.hash_test != hash_test) {
554                 /* wrong hash variant */
555                 ecode = tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
556                                    "tdb_open:"
557                                    " %s uses a different hash function",
558                                    name);
559                 goto fail;
560         }
561
562         /* Clear any features we don't understand. */
563         if ((open_flags & O_ACCMODE) != O_RDONLY) {
564                 hdr.features_used &= TDB_FEATURE_MASK;
565                 ecode = tdb_write_convert(tdb, offsetof(struct tdb_header,
566                                                         features_used),
567                                           &hdr.features_used,
568                                           sizeof(hdr.features_used));
569                 if (ecode != TDB_SUCCESS)
570                         goto fail;
571         }
572
573         tdb_unlock_open(tdb, openlock);
574
575         /* This make sure we have current map_size and mmap. */
576         ecode = tdb->tdb2.io->oob(tdb, tdb->file->map_size + 1, true);
577         if (unlikely(ecode != TDB_SUCCESS))
578                 goto fail;
579
580         /* Now it's fully formed, recover if necessary. */
581         berr = tdb_needs_recovery(tdb);
582         if (unlikely(berr != false)) {
583                 if (berr < 0) {
584                         ecode = berr;
585                         goto fail;
586                 }
587                 ecode = tdb_lock_and_recover(tdb);
588                 if (ecode != TDB_SUCCESS) {
589                         goto fail;
590                 }
591         }
592
593         ecode = tdb_ftable_init(tdb);
594         if (ecode != TDB_SUCCESS) {
595                 goto fail;
596         }
597
598         tdb->next = tdbs;
599         tdbs = tdb;
600         return tdb;
601
602  fail:
603         /* Map ecode to some logical errno. */
604         switch (ecode) {
605         case TDB_ERR_CORRUPT:
606         case TDB_ERR_IO:
607                 saved_errno = EIO;
608                 break;
609         case TDB_ERR_LOCK:
610                 saved_errno = EWOULDBLOCK;
611                 break;
612         case TDB_ERR_OOM:
613                 saved_errno = ENOMEM;
614                 break;
615         case TDB_ERR_EINVAL:
616                 saved_errno = EINVAL;
617                 break;
618         default:
619                 saved_errno = EINVAL;
620                 break;
621         }
622
623 fail_errno:
624 #ifdef TDB_TRACE
625         close(tdb->tracefd);
626 #endif
627         if (tdb->file) {
628                 tdb_lock_cleanup(tdb);
629                 if (--tdb->file->refcnt == 0) {
630                         assert(tdb->file->num_lockrecs == 0);
631                         if (tdb->file->map_ptr) {
632                                 if (tdb->flags & TDB_INTERNAL) {
633                                         free(tdb->file->map_ptr);
634                                 } else
635                                         tdb_munmap(tdb->file);
636                         }
637                         if (close(tdb->file->fd) != 0)
638                                 tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
639                                            "tdb_open: failed to close tdb fd"
640                                            " on error: %s", strerror(errno));
641                         free(tdb->file->lockrecs);
642                         free(tdb->file);
643                 }
644         }
645
646         free(tdb);
647         errno = saved_errno;
648         return NULL;
649 }
650
651 int tdb_close(struct tdb_context *tdb)
652 {
653         int ret = 0;
654         struct tdb_context **i;
655
656         tdb_trace(tdb, "tdb_close");
657
658         if (tdb->tdb2.transaction) {
659                 tdb_transaction_cancel(tdb);
660         }
661
662         if (tdb->file->map_ptr) {
663                 if (tdb->flags & TDB_INTERNAL)
664                         free(tdb->file->map_ptr);
665                 else
666                         tdb_munmap(tdb->file);
667         }
668         if (tdb->file) {
669                 tdb_lock_cleanup(tdb);
670                 if (--tdb->file->refcnt == 0) {
671                         ret = close(tdb->file->fd);
672                         free(tdb->file->lockrecs);
673                         free(tdb->file);
674                 }
675         }
676
677         /* Remove from tdbs list */
678         for (i = &tdbs; *i; i = &(*i)->next) {
679                 if (*i == tdb) {
680                         *i = tdb->next;
681                         break;
682                 }
683         }
684
685 #ifdef TDB_TRACE
686         close(tdb->tracefd);
687 #endif
688         free(tdb);
689
690         return ret;
691 }
692
693 void tdb_foreach_(int (*fn)(struct tdb_context *, void *), void *p)
694 {
695         struct tdb_context *i;
696
697         for (i = tdbs; i; i = i->next) {
698                 if (fn(i, p) != 0)
699                         break;
700         }
701 }