git.ozlabs.org Git - ccan/blob - ccan/tdb2/tdb.c

   1 #include "private.h"
   2 #include <ccan/tdb2/tdb2.h>
   3 #include <ccan/build_assert/build_assert.h>
   4 #include <ccan/likely/likely.h>
   5 #include <assert.h>
   6
   7 /* The null return. */
   8 struct tdb_data tdb_null = { .dptr = NULL, .dsize = 0 };
   9
  10 /* all contexts, to ensure no double-opens (fcntl locks don't nest!) */
  11 static struct tdb_context *tdbs = NULL;
  12
  13 PRINTF_FMT(4, 5) static void
  14 null_log_fn(struct tdb_context *tdb,
  15             enum tdb_debug_level level, void *priv,
  16             const char *fmt, ...)
  17 {
  18 }
  19
  20 static bool tdb_already_open(dev_t device, ino_t ino)
  21 {
  22         struct tdb_context *i;
  23
  24         for (i = tdbs; i; i = i->next) {
  25                 if (i->device == device && i->inode == ino) {
  26                         return true;
  27                 }
  28         }
  29
  30         return false;
  31 }
  32
  33 static uint64_t random_number(struct tdb_context *tdb)
  34 {
  35         int fd;
  36         uint64_t ret = 0;
  37         struct timeval now;
  38
  39         fd = open("/dev/urandom", O_RDONLY);
  40         if (fd >= 0) {
  41                 if (tdb_read_all(fd, &ret, sizeof(ret))) {
  42                         tdb->log(tdb, TDB_DEBUG_TRACE, tdb->log_priv,
  43                                  "tdb_open: random from /dev/urandom\n");
  44                         close(fd);
  45                         return ret;
  46                 }
  47                 close(fd);
  48         }
  49         /* FIXME: Untested!  Based on Wikipedia protocol description! */
  50         fd = open("/dev/egd-pool", O_RDWR);
  51         if (fd >= 0) {
  52                 /* Command is 1, next byte is size we want to read. */
  53                 char cmd[2] = { 1, sizeof(uint64_t) };
  54                 if (write(fd, cmd, sizeof(cmd)) == sizeof(cmd)) {
  55                         char reply[1 + sizeof(uint64_t)];
  56                         int r = read(fd, reply, sizeof(reply));
  57                         if (r > 1) {
  58                                 tdb->log(tdb, TDB_DEBUG_TRACE, tdb->log_priv,
  59                                          "tdb_open: %u random bytes from"
  60                                          " /dev/egd-pool\n", r-1);
  61                                 /* Copy at least some bytes. */
  62                                 memcpy(&ret, reply+1, r - 1);
  63                                 if (reply[0] == sizeof(uint64_t)
  64                                     && r == sizeof(reply)) {
  65                                         close(fd);
  66                                         return ret;
  67                                 }
  68                         }
  69                 }
  70                 close(fd);
  71         }
  72
  73         /* Fallback: pid and time. */
  74         gettimeofday(&now, NULL);
  75         ret = getpid() * 100132289ULL + now.tv_sec * 1000000ULL + now.tv_usec;
  76         tdb->log(tdb, TDB_DEBUG_TRACE, tdb->log_priv,
  77                  "tdb_open: random from getpid and time\n");
  78         return ret;
  79 }
  80
  81 struct new_database {
  82         struct tdb_header hdr;
  83         struct tdb_freelist flist;
  84 };
  85
  86 /* initialise a new database */
  87 static int tdb_new_database(struct tdb_context *tdb,
  88                             struct tdb_attribute_seed *seed,
  89                             struct tdb_header *hdr)
  90 {
  91         /* We make it up in memory, then write it out if not internal */
  92         struct new_database newdb;
  93         unsigned int magic_len;
  94
  95         /* Fill in the header */
  96         newdb.hdr.version = TDB_VERSION;
  97         if (seed)
  98                 newdb.hdr.hash_seed = seed->seed;
  99         else
 100                 newdb.hdr.hash_seed = random_number(tdb);
 101         newdb.hdr.hash_test = TDB_HASH_MAGIC;
 102         newdb.hdr.hash_test = tdb->khash(&newdb.hdr.hash_test,
 103                                          sizeof(newdb.hdr.hash_test),
 104                                          newdb.hdr.hash_seed,
 105                                          tdb->hash_priv);
 106         newdb.hdr.recovery = 0;
 107         memset(newdb.hdr.reserved, 0, sizeof(newdb.hdr.reserved));
 108         /* Initial hashes are empty. */
 109         memset(newdb.hdr.hashtable, 0, sizeof(newdb.hdr.hashtable));
 110
 111         /* Free is empty. */
 112         newdb.hdr.free_list = offsetof(struct new_database, flist);
 113         memset(&newdb.flist, 0, sizeof(newdb.flist));
 114         set_header(NULL, &newdb.flist.hdr, 0,
 115                    sizeof(newdb.flist) - sizeof(newdb.flist.hdr),
 116                    sizeof(newdb.flist) - sizeof(newdb.flist.hdr), 1);
 117
 118         /* Magic food */
 119         memset(newdb.hdr.magic_food, 0, sizeof(newdb.hdr.magic_food));
 120         strcpy(newdb.hdr.magic_food, TDB_MAGIC_FOOD);
 121
 122         /* This creates an endian-converted database, as if read from disk */
 123         magic_len = sizeof(newdb.hdr.magic_food);
 124         tdb_convert(tdb,
 125                     (char *)&newdb.hdr + magic_len, sizeof(newdb) - magic_len);
 126
 127         *hdr = newdb.hdr;
 128
 129         if (tdb->flags & TDB_INTERNAL) {
 130                 tdb->map_size = sizeof(newdb);
 131                 tdb->map_ptr = malloc(tdb->map_size);
 132                 if (!tdb->map_ptr) {
 133                         tdb->ecode = TDB_ERR_OOM;
 134                         return -1;
 135                 }
 136                 memcpy(tdb->map_ptr, &newdb, tdb->map_size);
 137                 return 0;
 138         }
 139         if (lseek(tdb->fd, 0, SEEK_SET) == -1)
 140                 return -1;
 141
 142         if (ftruncate(tdb->fd, 0) == -1)
 143                 return -1;
 144
 145         if (!tdb_pwrite_all(tdb->fd, &newdb, sizeof(newdb), 0)) {
 146                 tdb->ecode = TDB_ERR_IO;
 147                 return -1;
 148         }
 149         return 0;
 150 }
 151
 152 struct tdb_context *tdb_open(const char *name, int tdb_flags,
 153                              int open_flags, mode_t mode,
 154                              union tdb_attribute *attr)
 155 {
 156         struct tdb_context *tdb;
 157         struct stat st;
 158         int save_errno;
 159         uint64_t hash_test;
 160         unsigned v;
 161         struct tdb_header hdr;
 162         struct tdb_attribute_seed *seed = NULL;
 163
 164         tdb = malloc(sizeof(*tdb));
 165         if (!tdb) {
 166                 /* Can't log this */
 167                 errno = ENOMEM;
 168                 goto fail;
 169         }
 170         tdb->name = NULL;
 171         tdb->map_ptr = NULL;
 172         tdb->direct_access = 0;
 173         tdb->fd = -1;
 174         tdb->map_size = sizeof(struct tdb_header);
 175         tdb->ecode = TDB_SUCCESS;
 176         tdb->flags = tdb_flags;
 177         tdb->log = null_log_fn;
 178         tdb->log_priv = NULL;
 179         tdb->transaction = NULL;
 180         tdb_hash_init(tdb);
 181         tdb_io_init(tdb);
 182         tdb_lock_init(tdb);
 183
 184         while (attr) {
 185                 switch (attr->base.attr) {
 186                 case TDB_ATTRIBUTE_LOG:
 187                         tdb->log = attr->log.log_fn;
 188                         tdb->log_priv = attr->log.log_private;
 189                         break;
 190                 case TDB_ATTRIBUTE_HASH:
 191                         tdb->khash = attr->hash.hash_fn;
 192                         tdb->hash_priv = attr->hash.hash_private;
 193                         break;
 194                 case TDB_ATTRIBUTE_SEED:
 195                         seed = &attr->seed;
 196                         break;
 197                 default:
 198                         tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
 199                                  "tdb_open: unknown attribute type %u\n",
 200                                  attr->base.attr);
 201                         errno = EINVAL;
 202                         goto fail;
 203                 }
 204                 attr = attr->base.next;
 205         }
 206
 207         if ((open_flags & O_ACCMODE) == O_WRONLY) {
 208                 tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
 209                          "tdb_open: can't open tdb %s write-only\n", name);
 210                 errno = EINVAL;
 211                 goto fail;
 212         }
 213
 214         if ((open_flags & O_ACCMODE) == O_RDONLY) {
 215                 tdb->read_only = true;
 216                 /* read only databases don't do locking */
 217                 tdb->flags |= TDB_NOLOCK;
 218                 tdb->mmap_flags = PROT_READ;
 219         } else {
 220                 tdb->read_only = false;
 221                 tdb->mmap_flags = PROT_READ | PROT_WRITE;
 222         }
 223
 224         /* internal databases don't need any of the rest. */
 225         if (tdb->flags & TDB_INTERNAL) {
 226                 tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);
 227                 if (tdb_new_database(tdb, seed, &hdr) != 0) {
 228                         tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
 229                                  "tdb_open: tdb_new_database failed!");
 230                         goto fail;
 231                 }
 232                 tdb_convert(tdb, &hdr.hash_seed, sizeof(hdr.hash_seed));
 233                 tdb->hash_seed = hdr.hash_seed;
 234                 tdb_flist_init(tdb);
 235                 return tdb;
 236         }
 237
 238         if ((tdb->fd = open(name, open_flags, mode)) == -1) {
 239                 tdb->log(tdb, TDB_DEBUG_WARNING, tdb->log_priv,
 240                          "tdb_open: could not open file %s: %s\n",
 241                          name, strerror(errno));
 242                 goto fail;      /* errno set by open(2) */
 243         }
 244
 245         /* on exec, don't inherit the fd */
 246         v = fcntl(tdb->fd, F_GETFD, 0);
 247         fcntl(tdb->fd, F_SETFD, v | FD_CLOEXEC);
 248
 249         /* ensure there is only one process initialising at once */
 250         if (tdb_lock_open(tdb, TDB_LOCK_WAIT|TDB_LOCK_NOCHECK) == -1) {
 251                 tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
 252                          "tdb_open: failed to get open lock on %s: %s\n",
 253                          name, strerror(errno));
 254                 goto fail;      /* errno set by tdb_brlock */
 255         }
 256
 257         if (!tdb_pread_all(tdb->fd, &hdr, sizeof(hdr), 0)
 258             || strcmp(hdr.magic_food, TDB_MAGIC_FOOD) != 0) {
 259                 if (!(open_flags & O_CREAT)
 260                     || tdb_new_database(tdb, seed, &hdr) == -1) {
 261                         if (errno == 0) {
 262                                 errno = EIO; /* ie bad format or something */
 263                         }
 264                         goto fail;
 265                 }
 266         } else if (hdr.version != TDB_VERSION) {
 267                 if (hdr.version == bswap_64(TDB_VERSION))
 268                         tdb->flags |= TDB_CONVERT;
 269                 else {
 270                         /* wrong version */
 271                         tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
 272                                  "tdb_open: %s is unknown version 0x%llx\n",
 273                                  name, (long long)hdr.version);
 274                         errno = EIO;
 275                         goto fail;
 276                 }
 277         }
 278
 279         tdb_convert(tdb, &hdr, sizeof(hdr));
 280         tdb->hash_seed = hdr.hash_seed;
 281         hash_test = TDB_HASH_MAGIC;
 282         hash_test = tdb_hash(tdb, &hash_test, sizeof(hash_test));
 283         if (hdr.hash_test != hash_test) {
 284                 /* wrong hash variant */
 285                 tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
 286                          "tdb_open: %s uses a different hash function\n",
 287                          name);
 288                 errno = EIO;
 289                 goto fail;
 290         }
 291
 292         if (fstat(tdb->fd, &st) == -1)
 293                 goto fail;
 294
 295         /* Is it already in the open list?  If so, fail. */
 296         if (tdb_already_open(st.st_dev, st.st_ino)) {
 297                 /* FIXME */
 298                 tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
 299                          "tdb_open: %s (%d,%d) is already open in this process\n",
 300                          name, (int)st.st_dev, (int)st.st_ino);
 301                 errno = EBUSY;
 302                 goto fail;
 303         }
 304
 305         tdb->name = strdup(name);
 306         if (!tdb->name) {
 307                 errno = ENOMEM;
 308                 goto fail;
 309         }
 310
 311         tdb->device = st.st_dev;
 312         tdb->inode = st.st_ino;
 313         tdb_unlock_open(tdb);
 314
 315         /* This make sure we have current map_size and mmap. */
 316         tdb->methods->oob(tdb, tdb->map_size + 1, true);
 317
 318         /* Now it's fully formed, recover if necessary. */
 319         if (tdb_needs_recovery(tdb) && tdb_lock_and_recover(tdb) == -1) {
 320                 errno = EIO;
 321                 goto fail;
 322         }
 323
 324         if (tdb_flist_init(tdb) == -1)
 325                 goto fail;
 326
 327         tdb->next = tdbs;
 328         tdbs = tdb;
 329         return tdb;
 330
 331  fail:
 332         save_errno = errno;
 333
 334         if (!tdb)
 335                 return NULL;
 336
 337 #ifdef TDB_TRACE
 338         close(tdb->tracefd);
 339 #endif
 340         if (tdb->map_ptr) {
 341                 if (tdb->flags & TDB_INTERNAL) {
 342                         free(tdb->map_ptr);
 343                 } else
 344                         tdb_munmap(tdb);
 345         }
 346         free((char *)tdb->name);
 347         if (tdb->fd != -1)
 348                 if (close(tdb->fd) != 0)
 349                         tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
 350                                  "tdb_open: failed to close tdb->fd"
 351                                  " on error!\n");
 352         free(tdb);
 353         errno = save_errno;
 354         return NULL;
 355 }
 356
 357 /* FIXME: modify, don't rewrite! */
 358 static int update_rec_hdr(struct tdb_context *tdb,
 359                           tdb_off_t off,
 360                           tdb_len_t keylen,
 361                           tdb_len_t datalen,
 362                           struct tdb_used_record *rec,
 363                           uint64_t h)
 364 {
 365         uint64_t dataroom = rec_data_length(rec) + rec_extra_padding(rec);
 366
 367         if (set_header(tdb, rec, keylen, datalen, keylen + dataroom, h))
 368                 return -1;
 369
 370         return tdb_write_convert(tdb, off, rec, sizeof(*rec));
 371 }
 372
 373 /* Returns -1 on error, 0 on OK */
 374 static int replace_data(struct tdb_context *tdb,
 375                         struct hash_info *h,
 376                         struct tdb_data key, struct tdb_data dbuf,
 377                         tdb_off_t old_off, tdb_len_t old_room,
 378                         bool growing)
 379 {
 380         tdb_off_t new_off;
 381
 382         /* Allocate a new record. */
 383         new_off = alloc(tdb, key.dsize, dbuf.dsize, h->h, growing);
 384         if (unlikely(new_off == TDB_OFF_ERR))
 385                 return -1;
 386
 387         /* We didn't like the existing one: remove it. */
 388         if (old_off) {
 389                 add_free_record(tdb, old_off,
 390                                 sizeof(struct tdb_used_record)
 391                                 + key.dsize + old_room);
 392                 if (replace_in_hash(tdb, h, new_off) == -1)
 393                         return -1;
 394         } else {
 395                 if (add_to_hash(tdb, h, new_off) == -1)
 396                         return -1;
 397         }
 398
 399         new_off += sizeof(struct tdb_used_record);
 400         if (tdb->methods->write(tdb, new_off, key.dptr, key.dsize) == -1)
 401                 return -1;
 402
 403         new_off += key.dsize;
 404         if (tdb->methods->write(tdb, new_off, dbuf.dptr, dbuf.dsize) == -1)
 405                 return -1;
 406
 407         /* FIXME: tdb_increment_seqnum(tdb); */
 408         return 0;
 409 }
 410
 411 int tdb_store(struct tdb_context *tdb,
 412               struct tdb_data key, struct tdb_data dbuf, int flag)
 413 {
 414         struct hash_info h;
 415         tdb_off_t off;
 416         tdb_len_t old_room = 0;
 417         struct tdb_used_record rec;
 418         int ret;
 419
 420         off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
 421         if (unlikely(off == TDB_OFF_ERR))
 422                 return -1;
 423
 424         /* Now we have lock on this hash bucket. */
 425         if (flag == TDB_INSERT) {
 426                 if (off) {
 427                         tdb->ecode = TDB_ERR_EXISTS;
 428                         goto fail;
 429                 }
 430         } else {
 431                 if (off) {
 432                         old_room = rec_data_length(&rec)
 433                                 + rec_extra_padding(&rec);
 434                         if (old_room >= dbuf.dsize) {
 435                                 /* Can modify in-place.  Easy! */
 436                                 if (update_rec_hdr(tdb, off,
 437                                                    key.dsize, dbuf.dsize,
 438                                                    &rec, h.h))
 439                                         goto fail;
 440                                 if (tdb->methods->write(tdb, off + sizeof(rec)
 441                                                         + key.dsize,
 442                                                         dbuf.dptr, dbuf.dsize))
 443                                         goto fail;
 444                                 tdb_unlock_hashes(tdb, h.hlock_start,
 445                                                   h.hlock_range, F_WRLCK);
 446                                 return 0;
 447                         }
 448                         /* FIXME: See if right record is free? */
 449                 } else {
 450                         if (flag == TDB_MODIFY) {
 451                                 /* if the record doesn't exist and we
 452                                    are in TDB_MODIFY mode then we should fail
 453                                    the store */
 454                                 tdb->ecode = TDB_ERR_NOEXIST;
 455                                 goto fail;
 456                         }
 457                 }
 458         }
 459
 460         /* If we didn't use the old record, this implies we're growing. */
 461         ret = replace_data(tdb, &h, key, dbuf, off, old_room, off != 0);
 462         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
 463         return ret;
 464
 465 fail:
 466         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
 467         return -1;
 468 }
 469
 470 int tdb_append(struct tdb_context *tdb,
 471                struct tdb_data key, struct tdb_data dbuf)
 472 {
 473         struct hash_info h;
 474         tdb_off_t off;
 475         struct tdb_used_record rec;
 476         tdb_len_t old_room = 0, old_dlen;
 477         unsigned char *newdata;
 478         struct tdb_data new_dbuf;
 479         int ret;
 480
 481         off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
 482         if (unlikely(off == TDB_OFF_ERR))
 483                 return -1;
 484
 485         if (off) {
 486                 old_dlen = rec_data_length(&rec);
 487                 old_room = old_dlen + rec_extra_padding(&rec);
 488
 489                 /* Fast path: can append in place. */
 490                 if (rec_extra_padding(&rec) >= dbuf.dsize) {
 491                         if (update_rec_hdr(tdb, off, key.dsize,
 492                                            old_dlen + dbuf.dsize, &rec, h.h))
 493                                 goto fail;
 494
 495                         off += sizeof(rec) + key.dsize + old_dlen;
 496                         if (tdb->methods->write(tdb, off, dbuf.dptr,
 497                                                 dbuf.dsize) == -1)
 498                                 goto fail;
 499
 500                         /* FIXME: tdb_increment_seqnum(tdb); */
 501                         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range,
 502                                           F_WRLCK);
 503                         return 0;
 504                 }
 505                 /* FIXME: Check right record free? */
 506
 507                 /* Slow path. */
 508                 newdata = malloc(key.dsize + old_dlen + dbuf.dsize);
 509                 if (!newdata) {
 510                         tdb->ecode = TDB_ERR_OOM;
 511                         tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
 512                                  "tdb_append: cannot allocate %llu bytes!\n",
 513                                  (long long)key.dsize + old_dlen + dbuf.dsize);
 514                         goto fail;
 515                 }
 516                 if (tdb->methods->read(tdb, off + sizeof(rec) + key.dsize,
 517                                        newdata, old_dlen) != 0) {
 518                         free(newdata);
 519                         goto fail;
 520                 }
 521                 memcpy(newdata + old_dlen, dbuf.dptr, dbuf.dsize);
 522                 new_dbuf.dptr = newdata;
 523                 new_dbuf.dsize = old_dlen + dbuf.dsize;
 524         } else {
 525                 newdata = NULL;
 526                 new_dbuf = dbuf;
 527         }
 528
 529         /* If they're using tdb_append(), it implies they're growing record. */
 530         ret = replace_data(tdb, &h, key, new_dbuf, off, old_room, true);
 531         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
 532         free(newdata);
 533
 534         return ret;
 535
 536 fail:
 537         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
 538         return -1;
 539 }
 540
 541 struct tdb_data tdb_fetch(struct tdb_context *tdb, struct tdb_data key)
 542 {
 543         tdb_off_t off;
 544         struct tdb_used_record rec;
 545         struct hash_info h;
 546         struct tdb_data ret;
 547
 548         off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
 549         if (unlikely(off == TDB_OFF_ERR))
 550                 return tdb_null;
 551
 552         if (!off) {
 553                 tdb->ecode = TDB_ERR_NOEXIST;
 554                 ret = tdb_null;
 555         } else {
 556                 ret.dsize = rec_data_length(&rec);
 557                 ret.dptr = tdb_alloc_read(tdb, off + sizeof(rec) + key.dsize,
 558                                           ret.dsize);
 559         }
 560
 561         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
 562         return ret;
 563 }
 564
 565 int tdb_delete(struct tdb_context *tdb, struct tdb_data key)
 566 {
 567         tdb_off_t off;
 568         struct tdb_used_record rec;
 569         struct hash_info h;
 570
 571         off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
 572         if (unlikely(off == TDB_OFF_ERR))
 573                 return -1;
 574
 575         if (!off) {
 576                 tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
 577                 tdb->ecode = TDB_ERR_NOEXIST;
 578                 return -1;
 579         }
 580
 581         if (delete_from_hash(tdb, &h) == -1)
 582                 goto unlock_err;
 583
 584         /* Free the deleted entry. */
 585         if (add_free_record(tdb, off,
 586                             sizeof(struct tdb_used_record)
 587                             + rec_key_length(&rec)
 588                             + rec_data_length(&rec)
 589                             + rec_extra_padding(&rec)) != 0)
 590                 goto unlock_err;
 591
 592         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
 593         return 0;
 594
 595 unlock_err:
 596         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
 597         return -1;
 598 }
 599
 600 int tdb_close(struct tdb_context *tdb)
 601 {
 602         struct tdb_context **i;
 603         int ret = 0;
 604
 605         tdb_trace(tdb, "tdb_close");
 606
 607         if (tdb->transaction) {
 608                 tdb_transaction_cancel(tdb);
 609         }
 610
 611         if (tdb->map_ptr) {
 612                 if (tdb->flags & TDB_INTERNAL)
 613                         free(tdb->map_ptr);
 614                 else
 615                         tdb_munmap(tdb);
 616         }
 617         free((char *)tdb->name);
 618         if (tdb->fd != -1) {
 619                 ret = close(tdb->fd);
 620                 tdb->fd = -1;
 621         }
 622         free(tdb->lockrecs);
 623
 624         /* Remove from contexts list */
 625         for (i = &tdbs; *i; i = &(*i)->next) {
 626                 if (*i == tdb) {
 627                         *i = tdb->next;
 628                         break;
 629                 }
 630         }
 631
 632 #ifdef TDB_TRACE
 633         close(tdb->tracefd);
 634 #endif
 635         free(tdb);
 636
 637         return ret;
 638 }
 639
 640 enum TDB_ERROR tdb_error(struct tdb_context *tdb)
 641 {
 642         return tdb->ecode;
 643 }
 644
 645 const char *tdb_errorstr(struct tdb_context *tdb)
 646 {
 647         /* Gcc warns if you miss a case in the switch, so use that. */
 648         switch (tdb->ecode) {
 649         case TDB_SUCCESS: return "Success";
 650         case TDB_ERR_CORRUPT: return "Corrupt database";
 651         case TDB_ERR_IO: return "IO Error";
 652         case TDB_ERR_LOCK: return "Locking error";
 653         case TDB_ERR_OOM: return "Out of memory";
 654         case TDB_ERR_EXISTS: return "Record exists";
 655         case TDB_ERR_NESTING: return "Transaction already started";
 656         case TDB_ERR_EINVAL: return "Invalid parameter";
 657         case TDB_ERR_NOEXIST: return "Record does not exist";
 658         case TDB_ERR_RDONLY: return "write not permitted";
 659         }
 660         return "Invalid error code";
 661 }