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_used_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->stats = NULL;
 181         tdb_hash_init(tdb);
 182         tdb_io_init(tdb);
 183         tdb_lock_init(tdb);
 184
 185         while (attr) {
 186                 switch (attr->base.attr) {
 187                 case TDB_ATTRIBUTE_LOG:
 188                         tdb->log = attr->log.log_fn;
 189                         tdb->log_priv = attr->log.log_private;
 190                         break;
 191                 case TDB_ATTRIBUTE_HASH:
 192                         tdb->khash = attr->hash.hash_fn;
 193                         tdb->hash_priv = attr->hash.hash_private;
 194                         break;
 195                 case TDB_ATTRIBUTE_SEED:
 196                         seed = &attr->seed;
 197                         break;
 198                 case TDB_ATTRIBUTE_STATS:
 199                         tdb->stats = &attr->stats;
 200                         /* They have stats we don't know about?  Tell them. */
 201                         if (tdb->stats->size > sizeof(attr->stats))
 202                                 tdb->stats->size = sizeof(attr->stats);
 203                         break;
 204                 default:
 205                         tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
 206                                  "tdb_open: unknown attribute type %u\n",
 207                                  attr->base.attr);
 208                         errno = EINVAL;
 209                         goto fail;
 210                 }
 211                 attr = attr->base.next;
 212         }
 213
 214         if ((open_flags & O_ACCMODE) == O_WRONLY) {
 215                 tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
 216                          "tdb_open: can't open tdb %s write-only\n", name);
 217                 errno = EINVAL;
 218                 goto fail;
 219         }
 220
 221         if ((open_flags & O_ACCMODE) == O_RDONLY) {
 222                 tdb->read_only = true;
 223                 /* read only databases don't do locking */
 224                 tdb->flags |= TDB_NOLOCK;
 225                 tdb->mmap_flags = PROT_READ;
 226         } else {
 227                 tdb->read_only = false;
 228                 tdb->mmap_flags = PROT_READ | PROT_WRITE;
 229         }
 230
 231         /* internal databases don't need any of the rest. */
 232         if (tdb->flags & TDB_INTERNAL) {
 233                 tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);
 234                 if (tdb_new_database(tdb, seed, &hdr) != 0) {
 235                         tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
 236                                  "tdb_open: tdb_new_database failed!");
 237                         goto fail;
 238                 }
 239                 tdb_convert(tdb, &hdr.hash_seed, sizeof(hdr.hash_seed));
 240                 tdb->hash_seed = hdr.hash_seed;
 241                 tdb_flist_init(tdb);
 242                 return tdb;
 243         }
 244
 245         if ((tdb->fd = open(name, open_flags, mode)) == -1) {
 246                 tdb->log(tdb, TDB_DEBUG_WARNING, tdb->log_priv,
 247                          "tdb_open: could not open file %s: %s\n",
 248                          name, strerror(errno));
 249                 goto fail;      /* errno set by open(2) */
 250         }
 251
 252         /* on exec, don't inherit the fd */
 253         v = fcntl(tdb->fd, F_GETFD, 0);
 254         fcntl(tdb->fd, F_SETFD, v | FD_CLOEXEC);
 255
 256         /* ensure there is only one process initialising at once */
 257         if (tdb_lock_open(tdb, TDB_LOCK_WAIT|TDB_LOCK_NOCHECK) == -1) {
 258                 tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
 259                          "tdb_open: failed to get open lock on %s: %s\n",
 260                          name, strerror(errno));
 261                 goto fail;      /* errno set by tdb_brlock */
 262         }
 263
 264         if (!tdb_pread_all(tdb->fd, &hdr, sizeof(hdr), 0)
 265             || strcmp(hdr.magic_food, TDB_MAGIC_FOOD) != 0) {
 266                 if (!(open_flags & O_CREAT)
 267                     || tdb_new_database(tdb, seed, &hdr) == -1) {
 268                         if (errno == 0) {
 269                                 errno = EIO; /* ie bad format or something */
 270                         }
 271                         goto fail;
 272                 }
 273         } else if (hdr.version != TDB_VERSION) {
 274                 if (hdr.version == bswap_64(TDB_VERSION))
 275                         tdb->flags |= TDB_CONVERT;
 276                 else {
 277                         /* wrong version */
 278                         tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
 279                                  "tdb_open: %s is unknown version 0x%llx\n",
 280                                  name, (long long)hdr.version);
 281                         errno = EIO;
 282                         goto fail;
 283                 }
 284         }
 285
 286         tdb_convert(tdb, &hdr, sizeof(hdr));
 287         tdb->hash_seed = hdr.hash_seed;
 288         hash_test = TDB_HASH_MAGIC;
 289         hash_test = tdb_hash(tdb, &hash_test, sizeof(hash_test));
 290         if (hdr.hash_test != hash_test) {
 291                 /* wrong hash variant */
 292                 tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
 293                          "tdb_open: %s uses a different hash function\n",
 294                          name);
 295                 errno = EIO;
 296                 goto fail;
 297         }
 298
 299         if (fstat(tdb->fd, &st) == -1)
 300                 goto fail;
 301
 302         /* Is it already in the open list?  If so, fail. */
 303         if (tdb_already_open(st.st_dev, st.st_ino)) {
 304                 /* FIXME */
 305                 tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
 306                          "tdb_open: %s (%d,%d) is already open in this process\n",
 307                          name, (int)st.st_dev, (int)st.st_ino);
 308                 errno = EBUSY;
 309                 goto fail;
 310         }
 311
 312         tdb->name = strdup(name);
 313         if (!tdb->name) {
 314                 errno = ENOMEM;
 315                 goto fail;
 316         }
 317
 318         tdb->device = st.st_dev;
 319         tdb->inode = st.st_ino;
 320         tdb_unlock_open(tdb);
 321
 322         /* This make sure we have current map_size and mmap. */
 323         tdb->methods->oob(tdb, tdb->map_size + 1, true);
 324
 325         /* Now it's fully formed, recover if necessary. */
 326         if (tdb_needs_recovery(tdb) && tdb_lock_and_recover(tdb) == -1) {
 327                 errno = EIO;
 328                 goto fail;
 329         }
 330
 331         if (tdb_flist_init(tdb) == -1)
 332                 goto fail;
 333
 334         tdb->next = tdbs;
 335         tdbs = tdb;
 336         return tdb;
 337
 338  fail:
 339         save_errno = errno;
 340
 341         if (!tdb)
 342                 return NULL;
 343
 344 #ifdef TDB_TRACE
 345         close(tdb->tracefd);
 346 #endif
 347         if (tdb->map_ptr) {
 348                 if (tdb->flags & TDB_INTERNAL) {
 349                         free(tdb->map_ptr);
 350                 } else
 351                         tdb_munmap(tdb);
 352         }
 353         free((char *)tdb->name);
 354         if (tdb->fd != -1)
 355                 if (close(tdb->fd) != 0)
 356                         tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
 357                                  "tdb_open: failed to close tdb->fd"
 358                                  " on error!\n");
 359         free(tdb);
 360         errno = save_errno;
 361         return NULL;
 362 }
 363
 364 /* FIXME: modify, don't rewrite! */
 365 static int update_rec_hdr(struct tdb_context *tdb,
 366                           tdb_off_t off,
 367                           tdb_len_t keylen,
 368                           tdb_len_t datalen,
 369                           struct tdb_used_record *rec,
 370                           uint64_t h)
 371 {
 372         uint64_t dataroom = rec_data_length(rec) + rec_extra_padding(rec);
 373
 374         if (set_used_header(tdb, rec, keylen, datalen, keylen + dataroom, h))
 375                 return -1;
 376
 377         return tdb_write_convert(tdb, off, rec, sizeof(*rec));
 378 }
 379
 380 /* Returns -1 on error, 0 on OK */
 381 static int replace_data(struct tdb_context *tdb,
 382                         struct hash_info *h,
 383                         struct tdb_data key, struct tdb_data dbuf,
 384                         tdb_off_t old_off, tdb_len_t old_room,
 385                         bool growing)
 386 {
 387         tdb_off_t new_off;
 388
 389         /* Allocate a new record. */
 390         new_off = alloc(tdb, key.dsize, dbuf.dsize, h->h, growing);
 391         if (unlikely(new_off == TDB_OFF_ERR))
 392                 return -1;
 393
 394         /* We didn't like the existing one: remove it. */
 395         if (old_off) {
 396                 add_stat(tdb, frees, 1);
 397                 add_free_record(tdb, old_off,
 398                                 sizeof(struct tdb_used_record)
 399                                 + key.dsize + old_room);
 400                 if (replace_in_hash(tdb, h, new_off) == -1)
 401                         return -1;
 402         } else {
 403                 if (add_to_hash(tdb, h, new_off) == -1)
 404                         return -1;
 405         }
 406
 407         new_off += sizeof(struct tdb_used_record);
 408         if (tdb->methods->write(tdb, new_off, key.dptr, key.dsize) == -1)
 409                 return -1;
 410
 411         new_off += key.dsize;
 412         if (tdb->methods->write(tdb, new_off, dbuf.dptr, dbuf.dsize) == -1)
 413                 return -1;
 414
 415         /* FIXME: tdb_increment_seqnum(tdb); */
 416         return 0;
 417 }
 418
 419 int tdb_store(struct tdb_context *tdb,
 420               struct tdb_data key, struct tdb_data dbuf, int flag)
 421 {
 422         struct hash_info h;
 423         tdb_off_t off;
 424         tdb_len_t old_room = 0;
 425         struct tdb_used_record rec;
 426         int ret;
 427
 428         off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
 429         if (unlikely(off == TDB_OFF_ERR))
 430                 return -1;
 431
 432         /* Now we have lock on this hash bucket. */
 433         if (flag == TDB_INSERT) {
 434                 if (off) {
 435                         tdb->ecode = TDB_ERR_EXISTS;
 436                         goto fail;
 437                 }
 438         } else {
 439                 if (off) {
 440                         old_room = rec_data_length(&rec)
 441                                 + rec_extra_padding(&rec);
 442                         if (old_room >= dbuf.dsize) {
 443                                 /* Can modify in-place.  Easy! */
 444                                 if (update_rec_hdr(tdb, off,
 445                                                    key.dsize, dbuf.dsize,
 446                                                    &rec, h.h))
 447                                         goto fail;
 448                                 if (tdb->methods->write(tdb, off + sizeof(rec)
 449                                                         + key.dsize,
 450                                                         dbuf.dptr, dbuf.dsize))
 451                                         goto fail;
 452                                 tdb_unlock_hashes(tdb, h.hlock_start,
 453                                                   h.hlock_range, F_WRLCK);
 454                                 return 0;
 455                         }
 456                         /* FIXME: See if right record is free? */
 457                 } else {
 458                         if (flag == TDB_MODIFY) {
 459                                 /* if the record doesn't exist and we
 460                                    are in TDB_MODIFY mode then we should fail
 461                                    the store */
 462                                 tdb->ecode = TDB_ERR_NOEXIST;
 463                                 goto fail;
 464                         }
 465                 }
 466         }
 467
 468         /* If we didn't use the old record, this implies we're growing. */
 469         ret = replace_data(tdb, &h, key, dbuf, off, old_room, off != 0);
 470         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
 471         return ret;
 472
 473 fail:
 474         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
 475         return -1;
 476 }
 477
 478 int tdb_append(struct tdb_context *tdb,
 479                struct tdb_data key, struct tdb_data dbuf)
 480 {
 481         struct hash_info h;
 482         tdb_off_t off;
 483         struct tdb_used_record rec;
 484         tdb_len_t old_room = 0, old_dlen;
 485         unsigned char *newdata;
 486         struct tdb_data new_dbuf;
 487         int ret;
 488
 489         off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
 490         if (unlikely(off == TDB_OFF_ERR))
 491                 return -1;
 492
 493         if (off) {
 494                 old_dlen = rec_data_length(&rec);
 495                 old_room = old_dlen + rec_extra_padding(&rec);
 496
 497                 /* Fast path: can append in place. */
 498                 if (rec_extra_padding(&rec) >= dbuf.dsize) {
 499                         if (update_rec_hdr(tdb, off, key.dsize,
 500                                            old_dlen + dbuf.dsize, &rec, h.h))
 501                                 goto fail;
 502
 503                         off += sizeof(rec) + key.dsize + old_dlen;
 504                         if (tdb->methods->write(tdb, off, dbuf.dptr,
 505                                                 dbuf.dsize) == -1)
 506                                 goto fail;
 507
 508                         /* FIXME: tdb_increment_seqnum(tdb); */
 509                         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range,
 510                                           F_WRLCK);
 511                         return 0;
 512                 }
 513                 /* FIXME: Check right record free? */
 514
 515                 /* Slow path. */
 516                 newdata = malloc(key.dsize + old_dlen + dbuf.dsize);
 517                 if (!newdata) {
 518                         tdb->ecode = TDB_ERR_OOM;
 519                         tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
 520                                  "tdb_append: cannot allocate %llu bytes!\n",
 521                                  (long long)key.dsize + old_dlen + dbuf.dsize);
 522                         goto fail;
 523                 }
 524                 if (tdb->methods->read(tdb, off + sizeof(rec) + key.dsize,
 525                                        newdata, old_dlen) != 0) {
 526                         free(newdata);
 527                         goto fail;
 528                 }
 529                 memcpy(newdata + old_dlen, dbuf.dptr, dbuf.dsize);
 530                 new_dbuf.dptr = newdata;
 531                 new_dbuf.dsize = old_dlen + dbuf.dsize;
 532         } else {
 533                 newdata = NULL;
 534                 new_dbuf = dbuf;
 535         }
 536
 537         /* If they're using tdb_append(), it implies they're growing record. */
 538         ret = replace_data(tdb, &h, key, new_dbuf, off, old_room, true);
 539         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
 540         free(newdata);
 541
 542         return ret;
 543
 544 fail:
 545         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
 546         return -1;
 547 }
 548
 549 struct tdb_data tdb_fetch(struct tdb_context *tdb, struct tdb_data key)
 550 {
 551         tdb_off_t off;
 552         struct tdb_used_record rec;
 553         struct hash_info h;
 554         struct tdb_data ret;
 555
 556         off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
 557         if (unlikely(off == TDB_OFF_ERR))
 558                 return tdb_null;
 559
 560         if (!off) {
 561                 tdb->ecode = TDB_ERR_NOEXIST;
 562                 ret = tdb_null;
 563         } else {
 564                 ret.dsize = rec_data_length(&rec);
 565                 ret.dptr = tdb_alloc_read(tdb, off + sizeof(rec) + key.dsize,
 566                                           ret.dsize);
 567         }
 568
 569         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
 570         return ret;
 571 }
 572
 573 int tdb_delete(struct tdb_context *tdb, struct tdb_data key)
 574 {
 575         tdb_off_t off;
 576         struct tdb_used_record rec;
 577         struct hash_info h;
 578
 579         off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
 580         if (unlikely(off == TDB_OFF_ERR))
 581                 return -1;
 582
 583         if (!off) {
 584                 tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
 585                 tdb->ecode = TDB_ERR_NOEXIST;
 586                 return -1;
 587         }
 588
 589         if (delete_from_hash(tdb, &h) == -1)
 590                 goto unlock_err;
 591
 592         /* Free the deleted entry. */
 593         add_stat(tdb, frees, 1);
 594         if (add_free_record(tdb, off,
 595                             sizeof(struct tdb_used_record)
 596                             + rec_key_length(&rec)
 597                             + rec_data_length(&rec)
 598                             + rec_extra_padding(&rec)) != 0)
 599                 goto unlock_err;
 600
 601         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
 602         return 0;
 603
 604 unlock_err:
 605         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
 606         return -1;
 607 }
 608
 609 int tdb_close(struct tdb_context *tdb)
 610 {
 611         struct tdb_context **i;
 612         int ret = 0;
 613
 614         tdb_trace(tdb, "tdb_close");
 615
 616         if (tdb->transaction) {
 617                 tdb_transaction_cancel(tdb);
 618         }
 619
 620         if (tdb->map_ptr) {
 621                 if (tdb->flags & TDB_INTERNAL)
 622                         free(tdb->map_ptr);
 623                 else
 624                         tdb_munmap(tdb);
 625         }
 626         free((char *)tdb->name);
 627         if (tdb->fd != -1) {
 628                 ret = close(tdb->fd);
 629                 tdb->fd = -1;
 630         }
 631         free(tdb->lockrecs);
 632
 633         /* Remove from contexts list */
 634         for (i = &tdbs; *i; i = &(*i)->next) {
 635                 if (*i == tdb) {
 636                         *i = tdb->next;
 637                         break;
 638                 }
 639         }
 640
 641 #ifdef TDB_TRACE
 642         close(tdb->tracefd);
 643 #endif
 644         free(tdb);
 645
 646         return ret;
 647 }
 648
 649 enum TDB_ERROR tdb_error(struct tdb_context *tdb)
 650 {
 651         return tdb->ecode;
 652 }
 653
 654 const char *tdb_errorstr(struct tdb_context *tdb)
 655 {
 656         /* Gcc warns if you miss a case in the switch, so use that. */
 657         switch (tdb->ecode) {
 658         case TDB_SUCCESS: return "Success";
 659         case TDB_ERR_CORRUPT: return "Corrupt database";
 660         case TDB_ERR_IO: return "IO Error";
 661         case TDB_ERR_LOCK: return "Locking error";
 662         case TDB_ERR_OOM: return "Out of memory";
 663         case TDB_ERR_EXISTS: return "Record exists";
 664         case TDB_ERR_NESTING: return "Transaction already started";
 665         case TDB_ERR_EINVAL: return "Invalid parameter";
 666         case TDB_ERR_NOEXIST: return "Record does not exist";
 667         case TDB_ERR_RDONLY: return "write not permitted";
 668         }
 669         return "Invalid error code";
 670 }