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

   1 #include "private.h"
   2 #include <ccan/tdb2/tdb2.h>
   3 #include <assert.h>
   4 #include <stdarg.h>
   5
   6 /* The null return. */
   7 struct tdb_data tdb_null = { .dptr = NULL, .dsize = 0 };
   8
   9 /* all contexts, to ensure no double-opens (fcntl locks don't nest!) */
  10 static struct tdb_context *tdbs = NULL;
  11
  12 static bool tdb_already_open(dev_t device, ino_t ino)
  13 {
  14         struct tdb_context *i;
  15
  16         for (i = tdbs; i; i = i->next) {
  17                 if (i->device == device && i->inode == ino) {
  18                         return true;
  19                 }
  20         }
  21
  22         return false;
  23 }
  24
  25 static bool read_all(int fd, void *buf, size_t len)
  26 {
  27         while (len) {
  28                 ssize_t ret;
  29                 ret = read(fd, buf, len);
  30                 if (ret < 0)
  31                         return false;
  32                 if (ret == 0) {
  33                         /* ETOOSHORT? */
  34                         errno = EWOULDBLOCK;
  35                         return false;
  36                 }
  37                 buf = (char *)buf + ret;
  38                 len -= ret;
  39         }
  40         return true;
  41 }
  42
  43 static uint64_t random_number(struct tdb_context *tdb)
  44 {
  45         int fd;
  46         uint64_t ret = 0;
  47         struct timeval now;
  48
  49         fd = open("/dev/urandom", O_RDONLY);
  50         if (fd >= 0) {
  51                 if (read_all(fd, &ret, sizeof(ret))) {
  52                         close(fd);
  53                         return ret;
  54                 }
  55                 close(fd);
  56         }
  57         /* FIXME: Untested!  Based on Wikipedia protocol description! */
  58         fd = open("/dev/egd-pool", O_RDWR);
  59         if (fd >= 0) {
  60                 /* Command is 1, next byte is size we want to read. */
  61                 char cmd[2] = { 1, sizeof(uint64_t) };
  62                 if (write(fd, cmd, sizeof(cmd)) == sizeof(cmd)) {
  63                         char reply[1 + sizeof(uint64_t)];
  64                         int r = read(fd, reply, sizeof(reply));
  65                         if (r > 1) {
  66                                 /* Copy at least some bytes. */
  67                                 memcpy(&ret, reply+1, r - 1);
  68                                 if (reply[0] == sizeof(uint64_t)
  69                                     && r == sizeof(reply)) {
  70                                         close(fd);
  71                                         return ret;
  72                                 }
  73                         }
  74                 }
  75                 close(fd);
  76         }
  77
  78         /* Fallback: pid and time. */
  79         gettimeofday(&now, NULL);
  80         ret = getpid() * 100132289ULL + now.tv_sec * 1000000ULL + now.tv_usec;
  81         tdb_logerr(tdb, TDB_SUCCESS, TDB_LOG_WARNING,
  82                    "tdb_open: random from getpid and time");
  83         return ret;
  84 }
  85
  86 struct new_database {
  87         struct tdb_header hdr;
  88         struct tdb_freetable ftable;
  89 };
  90
  91 /* initialise a new database */
  92 static int tdb_new_database(struct tdb_context *tdb,
  93                             struct tdb_attribute_seed *seed,
  94                             struct tdb_header *hdr)
  95 {
  96         /* We make it up in memory, then write it out if not internal */
  97         struct new_database newdb;
  98         unsigned int magic_len;
  99         ssize_t rlen;
 100
 101         /* Fill in the header */
 102         newdb.hdr.version = TDB_VERSION;
 103         if (seed)
 104                 newdb.hdr.hash_seed = seed->seed;
 105         else
 106                 newdb.hdr.hash_seed = random_number(tdb);
 107         newdb.hdr.hash_test = TDB_HASH_MAGIC;
 108         newdb.hdr.hash_test = tdb->khash(&newdb.hdr.hash_test,
 109                                          sizeof(newdb.hdr.hash_test),
 110                                          newdb.hdr.hash_seed,
 111                                          tdb->hash_priv);
 112         newdb.hdr.recovery = 0;
 113         memset(newdb.hdr.reserved, 0, sizeof(newdb.hdr.reserved));
 114         /* Initial hashes are empty. */
 115         memset(newdb.hdr.hashtable, 0, sizeof(newdb.hdr.hashtable));
 116
 117         /* Free is empty. */
 118         newdb.hdr.free_table = offsetof(struct new_database, ftable);
 119         memset(&newdb.ftable, 0, sizeof(newdb.ftable));
 120         tdb->ecode = set_header(NULL, &newdb.ftable.hdr, TDB_FTABLE_MAGIC, 0,
 121                                 sizeof(newdb.ftable) - sizeof(newdb.ftable.hdr),
 122                                 sizeof(newdb.ftable) - sizeof(newdb.ftable.hdr),
 123                                 0);
 124         if (tdb->ecode != TDB_SUCCESS) {
 125                 return -1;
 126         }
 127
 128         /* Magic food */
 129         memset(newdb.hdr.magic_food, 0, sizeof(newdb.hdr.magic_food));
 130         strcpy(newdb.hdr.magic_food, TDB_MAGIC_FOOD);
 131
 132         /* This creates an endian-converted database, as if read from disk */
 133         magic_len = sizeof(newdb.hdr.magic_food);
 134         tdb_convert(tdb,
 135                     (char *)&newdb.hdr + magic_len, sizeof(newdb) - magic_len);
 136
 137         *hdr = newdb.hdr;
 138
 139         if (tdb->flags & TDB_INTERNAL) {
 140                 tdb->map_size = sizeof(newdb);
 141                 tdb->map_ptr = malloc(tdb->map_size);
 142                 if (!tdb->map_ptr) {
 143                         tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
 144                                    "tdb_new_database: failed to allocate");
 145                         return -1;
 146                 }
 147                 memcpy(tdb->map_ptr, &newdb, tdb->map_size);
 148                 return 0;
 149         }
 150         if (lseek(tdb->fd, 0, SEEK_SET) == -1)
 151                 return -1;
 152
 153         if (ftruncate(tdb->fd, 0) == -1)
 154                 return -1;
 155
 156         rlen = write(tdb->fd, &newdb, sizeof(newdb));
 157         if (rlen != sizeof(newdb)) {
 158                 if (rlen >= 0)
 159                         errno = ENOSPC;
 160                 tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
 161                            "tdb_new_database: %zi writing header: %s",
 162                            rlen, strerror(errno));
 163                 return -1;
 164         }
 165         return 0;
 166 }
 167
 168 struct tdb_context *tdb_open(const char *name, int tdb_flags,
 169                              int open_flags, mode_t mode,
 170                              union tdb_attribute *attr)
 171 {
 172         struct tdb_context *tdb;
 173         struct stat st;
 174         int saved_errno = 0;
 175         uint64_t hash_test;
 176         unsigned v;
 177         ssize_t rlen;
 178         struct tdb_header hdr;
 179         struct tdb_attribute_seed *seed = NULL;
 180         enum TDB_ERROR ecode;
 181
 182         tdb = malloc(sizeof(*tdb));
 183         if (!tdb) {
 184                 /* Can't log this */
 185                 errno = ENOMEM;
 186                 return NULL;
 187         }
 188         tdb->name = NULL;
 189         tdb->map_ptr = NULL;
 190         tdb->direct_access = 0;
 191         tdb->fd = -1;
 192         tdb->map_size = sizeof(struct tdb_header);
 193         tdb->ecode = TDB_SUCCESS;
 194         tdb->flags = tdb_flags;
 195         tdb->logfn = NULL;
 196         tdb->transaction = NULL;
 197         tdb->stats = NULL;
 198         tdb->access = NULL;
 199         tdb_hash_init(tdb);
 200         tdb_io_init(tdb);
 201         tdb_lock_init(tdb);
 202
 203         while (attr) {
 204                 switch (attr->base.attr) {
 205                 case TDB_ATTRIBUTE_LOG:
 206                         tdb->logfn = attr->log.log_fn;
 207                         tdb->log_private = attr->log.log_private;
 208                         break;
 209                 case TDB_ATTRIBUTE_HASH:
 210                         tdb->khash = attr->hash.hash_fn;
 211                         tdb->hash_priv = attr->hash.hash_private;
 212                         break;
 213                 case TDB_ATTRIBUTE_SEED:
 214                         seed = &attr->seed;
 215                         break;
 216                 case TDB_ATTRIBUTE_STATS:
 217                         tdb->stats = &attr->stats;
 218                         /* They have stats we don't know about?  Tell them. */
 219                         if (tdb->stats->size > sizeof(attr->stats))
 220                                 tdb->stats->size = sizeof(attr->stats);
 221                         break;
 222                 default:
 223                         tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
 224                                    "tdb_open: unknown attribute type %u",
 225                                    attr->base.attr);
 226                         goto fail;
 227                 }
 228                 attr = attr->base.next;
 229         }
 230
 231         if ((open_flags & O_ACCMODE) == O_WRONLY) {
 232                 tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
 233                            "tdb_open: can't open tdb %s write-only", name);
 234                 goto fail;
 235         }
 236
 237         if ((open_flags & O_ACCMODE) == O_RDONLY) {
 238                 tdb->read_only = true;
 239                 /* read only databases don't do locking */
 240                 tdb->flags |= TDB_NOLOCK;
 241                 tdb->mmap_flags = PROT_READ;
 242         } else {
 243                 tdb->read_only = false;
 244                 tdb->mmap_flags = PROT_READ | PROT_WRITE;
 245         }
 246
 247         /* internal databases don't need any of the rest. */
 248         if (tdb->flags & TDB_INTERNAL) {
 249                 tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);
 250                 if (tdb_new_database(tdb, seed, &hdr) != 0) {
 251                         goto fail;
 252                 }
 253                 tdb_convert(tdb, &hdr.hash_seed, sizeof(hdr.hash_seed));
 254                 tdb->hash_seed = hdr.hash_seed;
 255                 tdb_ftable_init(tdb);
 256                 return tdb;
 257         }
 258
 259         if ((tdb->fd = open(name, open_flags, mode)) == -1) {
 260                 /* errno set by open(2) */
 261                 saved_errno = errno;
 262                 tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
 263                            "tdb_open: could not open file %s: %s",
 264                            name, strerror(errno));
 265                 goto fail;
 266         }
 267
 268         /* on exec, don't inherit the fd */
 269         v = fcntl(tdb->fd, F_GETFD, 0);
 270         fcntl(tdb->fd, F_SETFD, v | FD_CLOEXEC);
 271
 272         /* ensure there is only one process initialising at once */
 273         tdb->ecode = tdb_lock_open(tdb, TDB_LOCK_WAIT|TDB_LOCK_NOCHECK);
 274         if (tdb->ecode != TDB_SUCCESS) {
 275                 goto fail;
 276         }
 277
 278         /* If they used O_TRUNC, read will return 0. */
 279         rlen = read(tdb->fd, &hdr, sizeof(hdr));
 280         if (rlen == 0 && (open_flags & O_CREAT)) {
 281                 if (tdb_new_database(tdb, seed, &hdr) == -1) {
 282                         goto fail;
 283                 }
 284         } else if (rlen < 0) {
 285                 tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
 286                            "tdb_open: error %s reading %s",
 287                            strerror(errno), name);
 288                 goto fail;
 289         } else if (rlen < sizeof(hdr)
 290                    || strcmp(hdr.magic_food, TDB_MAGIC_FOOD) != 0) {
 291                 tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
 292                            "tdb_open: %s is not a tdb file", name);
 293                 goto fail;
 294         }
 295
 296         if (hdr.version != TDB_VERSION) {
 297                 if (hdr.version == bswap_64(TDB_VERSION))
 298                         tdb->flags |= TDB_CONVERT;
 299                 else {
 300                         /* wrong version */
 301                         tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
 302                                    "tdb_open: %s is unknown version 0x%llx",
 303                                    name, (long long)hdr.version);
 304                         goto fail;
 305                 }
 306         }
 307
 308         tdb_convert(tdb, &hdr, sizeof(hdr));
 309         tdb->hash_seed = hdr.hash_seed;
 310         hash_test = TDB_HASH_MAGIC;
 311         hash_test = tdb_hash(tdb, &hash_test, sizeof(hash_test));
 312         if (hdr.hash_test != hash_test) {
 313                 /* wrong hash variant */
 314                 tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
 315                            "tdb_open: %s uses a different hash function",
 316                            name);
 317                 goto fail;
 318         }
 319
 320         if (fstat(tdb->fd, &st) == -1) {
 321                 saved_errno = errno;
 322                 tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
 323                            "tdb_open: could not stat open %s: %s",
 324                            name, strerror(errno));
 325                 goto fail;
 326         }
 327
 328         /* Is it already in the open list?  If so, fail. */
 329         if (tdb_already_open(st.st_dev, st.st_ino)) {
 330                 /* FIXME */
 331                 tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_USE_ERROR,
 332                            "tdb_open: %s (%d,%d) is already open in this"
 333                            " process",
 334                            name, (int)st.st_dev, (int)st.st_ino);
 335                 goto fail;
 336         }
 337
 338         tdb->name = strdup(name);
 339         if (!tdb->name) {
 340                 tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
 341                            "tdb_open: failed to allocate name");
 342                 goto fail;
 343         }
 344
 345         tdb->device = st.st_dev;
 346         tdb->inode = st.st_ino;
 347         tdb_unlock_open(tdb);
 348
 349         /* This make sure we have current map_size and mmap. */
 350         tdb->methods->oob(tdb, tdb->map_size + 1, true);
 351
 352         /* Now it's fully formed, recover if necessary. */
 353         if (tdb_needs_recovery(tdb)) {
 354                 ecode = tdb_lock_and_recover(tdb);
 355                 if (ecode != TDB_SUCCESS) {
 356                         tdb->ecode = ecode;
 357                         goto fail;
 358                 }
 359         }
 360
 361         tdb->ecode = tdb_ftable_init(tdb);
 362         if (tdb->ecode != TDB_SUCCESS) {
 363                 goto fail;
 364         }
 365
 366         tdb->next = tdbs;
 367         tdbs = tdb;
 368         return tdb;
 369
 370  fail:
 371         /* Map ecode to some logical errno. */
 372         if (!saved_errno) {
 373                 switch (tdb->ecode) {
 374                 case TDB_ERR_CORRUPT:
 375                 case TDB_ERR_IO:
 376                         saved_errno = EIO;
 377                         break;
 378                 case TDB_ERR_LOCK:
 379                         saved_errno = EWOULDBLOCK;
 380                         break;
 381                 case TDB_ERR_OOM:
 382                         saved_errno = ENOMEM;
 383                         break;
 384                 case TDB_ERR_EINVAL:
 385                         saved_errno = EINVAL;
 386                         break;
 387                 default:
 388                         saved_errno = EINVAL;
 389                         break;
 390                 }
 391         }
 392
 393 #ifdef TDB_TRACE
 394         close(tdb->tracefd);
 395 #endif
 396         if (tdb->map_ptr) {
 397                 if (tdb->flags & TDB_INTERNAL) {
 398                         free(tdb->map_ptr);
 399                 } else
 400                         tdb_munmap(tdb);
 401         }
 402         free(tdb->lockrecs);
 403         free((char *)tdb->name);
 404         if (tdb->fd != -1)
 405                 if (close(tdb->fd) != 0)
 406                         tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
 407                                    "tdb_open: failed to close tdb->fd"
 408                                    " on error: %s", strerror(errno));
 409         free(tdb);
 410         errno = saved_errno;
 411         return NULL;
 412 }
 413
 414 static int update_rec_hdr(struct tdb_context *tdb,
 415                           tdb_off_t off,
 416                           tdb_len_t keylen,
 417                           tdb_len_t datalen,
 418                           struct tdb_used_record *rec,
 419                           uint64_t h)
 420 {
 421         uint64_t dataroom = rec_data_length(rec) + rec_extra_padding(rec);
 422         enum TDB_ERROR ecode;
 423
 424         ecode = set_header(tdb, rec, TDB_USED_MAGIC, keylen, datalen,
 425                            keylen + dataroom, h);
 426         if (ecode != TDB_SUCCESS) {
 427                 tdb->ecode = ecode;
 428                 return -1;
 429         }
 430
 431         ecode = tdb_write_convert(tdb, off, rec, sizeof(*rec));
 432         if (ecode != TDB_SUCCESS) {
 433                 tdb->ecode = ecode;
 434                 return -1;
 435         }
 436         return 0;
 437 }
 438
 439 /* Returns -1 on error, 0 on OK */
 440 static int replace_data(struct tdb_context *tdb,
 441                         struct hash_info *h,
 442                         struct tdb_data key, struct tdb_data dbuf,
 443                         tdb_off_t old_off, tdb_len_t old_room,
 444                         bool growing)
 445 {
 446         tdb_off_t new_off;
 447         enum TDB_ERROR ecode;
 448
 449         /* Allocate a new record. */
 450         new_off = alloc(tdb, key.dsize, dbuf.dsize, h->h, TDB_USED_MAGIC,
 451                         growing);
 452         if (TDB_OFF_IS_ERR(new_off)) {
 453                 tdb->ecode = new_off;
 454                 return -1;
 455         }
 456
 457         /* We didn't like the existing one: remove it. */
 458         if (old_off) {
 459                 add_stat(tdb, frees, 1);
 460                 ecode = add_free_record(tdb, old_off,
 461                                         sizeof(struct tdb_used_record)
 462                                         + key.dsize + old_room);
 463                 if (ecode == TDB_SUCCESS)
 464                         ecode = replace_in_hash(tdb, h, new_off);
 465         } else {
 466                 ecode = add_to_hash(tdb, h, new_off);
 467         }
 468         if (ecode != TDB_SUCCESS) {
 469                 tdb->ecode = ecode;
 470                 return -1;
 471         }
 472
 473         new_off += sizeof(struct tdb_used_record);
 474         ecode = tdb->methods->twrite(tdb, new_off, key.dptr, key.dsize);
 475         if (ecode != TDB_SUCCESS) {
 476                 tdb->ecode = ecode;
 477                 return -1;
 478         }
 479
 480         new_off += key.dsize;
 481         ecode = tdb->methods->twrite(tdb, new_off, dbuf.dptr, dbuf.dsize);
 482         if (ecode != TDB_SUCCESS) {
 483                 tdb->ecode = ecode;
 484                 return -1;
 485         }
 486
 487         /* FIXME: tdb_increment_seqnum(tdb); */
 488         return 0;
 489 }
 490
 491 int tdb_store(struct tdb_context *tdb,
 492               struct tdb_data key, struct tdb_data dbuf, int flag)
 493 {
 494         struct hash_info h;
 495         tdb_off_t off;
 496         tdb_len_t old_room = 0;
 497         struct tdb_used_record rec;
 498         int ret;
 499         enum TDB_ERROR ecode;
 500
 501         off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
 502         if (TDB_OFF_IS_ERR(off)) {
 503                 tdb->ecode = off;
 504                 return -1;
 505         }
 506
 507         /* Now we have lock on this hash bucket. */
 508         if (flag == TDB_INSERT) {
 509                 if (off) {
 510                         tdb->ecode = TDB_ERR_EXISTS;
 511                         goto fail;
 512                 }
 513         } else {
 514                 if (off) {
 515                         old_room = rec_data_length(&rec)
 516                                 + rec_extra_padding(&rec);
 517                         if (old_room >= dbuf.dsize) {
 518                                 /* Can modify in-place.  Easy! */
 519                                 if (update_rec_hdr(tdb, off,
 520                                                    key.dsize, dbuf.dsize,
 521                                                    &rec, h.h))
 522                                         goto fail;
 523                                 ecode = tdb->methods->twrite(tdb,
 524                                                              off + sizeof(rec)
 525                                                              + key.dsize,
 526                                                              dbuf.dptr,
 527                                                              dbuf.dsize);
 528                                 if (ecode != TDB_SUCCESS) {
 529                                         tdb->ecode = ecode;
 530                                         goto fail;
 531                                 }
 532                                 tdb_unlock_hashes(tdb, h.hlock_start,
 533                                                   h.hlock_range, F_WRLCK);
 534                                 return 0;
 535                         }
 536                 } else {
 537                         if (flag == TDB_MODIFY) {
 538                                 /* if the record doesn't exist and we
 539                                    are in TDB_MODIFY mode then we should fail
 540                                    the store */
 541                                 tdb->ecode = TDB_ERR_NOEXIST;
 542                                 goto fail;
 543                         }
 544                 }
 545         }
 546
 547         /* If we didn't use the old record, this implies we're growing. */
 548         ret = replace_data(tdb, &h, key, dbuf, off, old_room, off != 0);
 549         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
 550         return ret;
 551
 552 fail:
 553         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
 554         return -1;
 555 }
 556
 557 int tdb_append(struct tdb_context *tdb,
 558                struct tdb_data key, struct tdb_data dbuf)
 559 {
 560         struct hash_info h;
 561         tdb_off_t off;
 562         struct tdb_used_record rec;
 563         tdb_len_t old_room = 0, old_dlen;
 564         unsigned char *newdata;
 565         struct tdb_data new_dbuf;
 566         enum TDB_ERROR ecode;
 567         int ret;
 568
 569         off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
 570         if (TDB_OFF_IS_ERR(off)) {
 571                 tdb->ecode = off;
 572                 return -1;
 573         }
 574
 575         if (off) {
 576                 old_dlen = rec_data_length(&rec);
 577                 old_room = old_dlen + rec_extra_padding(&rec);
 578
 579                 /* Fast path: can append in place. */
 580                 if (rec_extra_padding(&rec) >= dbuf.dsize) {
 581                         if (update_rec_hdr(tdb, off, key.dsize,
 582                                            old_dlen + dbuf.dsize, &rec, h.h))
 583                                 goto fail;
 584
 585                         off += sizeof(rec) + key.dsize + old_dlen;
 586                         ecode = tdb->methods->twrite(tdb, off, dbuf.dptr,
 587                                                      dbuf.dsize);
 588                         if (ecode != TDB_SUCCESS) {
 589                                 tdb->ecode = ecode;
 590                                 goto fail;
 591                         }
 592
 593                         /* FIXME: tdb_increment_seqnum(tdb); */
 594                         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range,
 595                                           F_WRLCK);
 596                         return 0;
 597                 }
 598
 599                 /* Slow path. */
 600                 newdata = malloc(key.dsize + old_dlen + dbuf.dsize);
 601                 if (!newdata) {
 602                         tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
 603                                    "tdb_append: failed to allocate %zu bytes",
 604                                    (size_t)(key.dsize+old_dlen+dbuf.dsize));
 605                         goto fail;
 606                 }
 607                 ecode = tdb->methods->tread(tdb, off + sizeof(rec) + key.dsize,
 608                                             newdata, old_dlen);
 609                 if (ecode != TDB_SUCCESS) {
 610                         tdb->ecode = ecode;
 611                         free(newdata);
 612                         goto fail;
 613                 }
 614                 memcpy(newdata + old_dlen, dbuf.dptr, dbuf.dsize);
 615                 new_dbuf.dptr = newdata;
 616                 new_dbuf.dsize = old_dlen + dbuf.dsize;
 617         } else {
 618                 newdata = NULL;
 619                 new_dbuf = dbuf;
 620         }
 621
 622         /* If they're using tdb_append(), it implies they're growing record. */
 623         ret = replace_data(tdb, &h, key, new_dbuf, off, old_room, true);
 624         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
 625         free(newdata);
 626
 627         return ret;
 628
 629 fail:
 630         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
 631         return -1;
 632 }
 633
 634 struct tdb_data tdb_fetch(struct tdb_context *tdb, struct tdb_data key)
 635 {
 636         tdb_off_t off;
 637         struct tdb_used_record rec;
 638         struct hash_info h;
 639         struct tdb_data ret;
 640
 641         off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
 642         if (TDB_OFF_IS_ERR(off)) {
 643                 tdb->ecode = off;
 644                 return tdb_null;
 645         }
 646
 647         if (!off) {
 648                 tdb->ecode = TDB_ERR_NOEXIST;
 649                 ret = tdb_null;
 650         } else {
 651                 ret.dsize = rec_data_length(&rec);
 652                 ret.dptr = tdb_alloc_read(tdb, off + sizeof(rec) + key.dsize,
 653                                           ret.dsize);
 654                 if (TDB_PTR_IS_ERR(ret.dptr)) {
 655                         tdb->ecode = TDB_PTR_ERR(ret.dptr);
 656                         ret = tdb_null;
 657                 }
 658         }
 659
 660         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
 661         return ret;
 662 }
 663
 664 int tdb_delete(struct tdb_context *tdb, struct tdb_data key)
 665 {
 666         tdb_off_t off;
 667         struct tdb_used_record rec;
 668         struct hash_info h;
 669         enum TDB_ERROR ecode;
 670
 671         off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
 672         if (TDB_OFF_IS_ERR(off)) {
 673                 tdb->ecode = off;
 674                 return -1;
 675         }
 676
 677         if (!off) {
 678                 tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
 679                 tdb->ecode = TDB_ERR_NOEXIST;
 680                 return -1;
 681         }
 682
 683         ecode = delete_from_hash(tdb, &h);
 684         if (ecode != TDB_SUCCESS) {
 685                 tdb->ecode = ecode;
 686                 goto unlock_err;
 687         }
 688
 689         /* Free the deleted entry. */
 690         add_stat(tdb, frees, 1);
 691         ecode = add_free_record(tdb, off,
 692                                 sizeof(struct tdb_used_record)
 693                                 + rec_key_length(&rec)
 694                                 + rec_data_length(&rec)
 695                                 + rec_extra_padding(&rec));
 696         if (ecode != TDB_SUCCESS) {
 697                 tdb->ecode = ecode;
 698                 goto unlock_err;
 699         }
 700
 701         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
 702         return 0;
 703
 704 unlock_err:
 705         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
 706         return -1;
 707 }
 708
 709 int tdb_close(struct tdb_context *tdb)
 710 {
 711         struct tdb_context **i;
 712         int ret = 0;
 713
 714         tdb_trace(tdb, "tdb_close");
 715
 716         if (tdb->transaction) {
 717                 tdb_transaction_cancel(tdb);
 718         }
 719
 720         if (tdb->map_ptr) {
 721                 if (tdb->flags & TDB_INTERNAL)
 722                         free(tdb->map_ptr);
 723                 else
 724                         tdb_munmap(tdb);
 725         }
 726         free((char *)tdb->name);
 727         if (tdb->fd != -1) {
 728                 ret = close(tdb->fd);
 729                 tdb->fd = -1;
 730         }
 731         free(tdb->lockrecs);
 732
 733         /* Remove from contexts list */
 734         for (i = &tdbs; *i; i = &(*i)->next) {
 735                 if (*i == tdb) {
 736                         *i = tdb->next;
 737                         break;
 738                 }
 739         }
 740
 741 #ifdef TDB_TRACE
 742         close(tdb->tracefd);
 743 #endif
 744         free(tdb);
 745
 746         return ret;
 747 }
 748
 749 enum TDB_ERROR tdb_error(const struct tdb_context *tdb)
 750 {
 751         return tdb->ecode;
 752 }
 753
 754 const char *tdb_errorstr(const struct tdb_context *tdb)
 755 {
 756         /* Gcc warns if you miss a case in the switch, so use that. */
 757         switch (tdb->ecode) {
 758         case TDB_SUCCESS: return "Success";
 759         case TDB_ERR_CORRUPT: return "Corrupt database";
 760         case TDB_ERR_IO: return "IO Error";
 761         case TDB_ERR_LOCK: return "Locking error";
 762         case TDB_ERR_OOM: return "Out of memory";
 763         case TDB_ERR_EXISTS: return "Record exists";
 764         case TDB_ERR_EINVAL: return "Invalid parameter";
 765         case TDB_ERR_NOEXIST: return "Record does not exist";
 766         case TDB_ERR_RDONLY: return "write not permitted";
 767         }
 768         return "Invalid error code";
 769 }
 770
 771 enum TDB_ERROR COLD tdb_logerr(struct tdb_context *tdb,
 772                                enum TDB_ERROR ecode,
 773                                enum tdb_log_level level,
 774                                const char *fmt, ...)
 775 {
 776         char *message;
 777         va_list ap;
 778         size_t len;
 779         /* tdb_open paths care about errno, so save it. */
 780         int saved_errno = errno;
 781
 782         tdb->ecode = ecode;
 783
 784         if (!tdb->logfn)
 785                 return ecode;
 786
 787         /* FIXME: Doesn't assume asprintf. */
 788         va_start(ap, fmt);
 789         len = vsnprintf(NULL, 0, fmt, ap);
 790         va_end(ap);
 791
 792         message = malloc(len + 1);
 793         if (!message) {
 794                 tdb->logfn(tdb, TDB_LOG_ERROR, tdb->log_private,
 795                            "out of memory formatting message:");
 796                 tdb->logfn(tdb, level, tdb->log_private, fmt);
 797                 return ecode;
 798         }
 799         va_start(ap, fmt);
 800         len = vsprintf(message, fmt, ap);
 801         va_end(ap);
 802         tdb->logfn(tdb, level, tdb->log_private, message);
 803         free(message);
 804         errno = saved_errno;
 805         return ecode;
 806 }