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

   1  /*
   2    Trivial Database 2: free list/block handling
   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/likely/likely.h>
  20 #include <ccan/asearch/asearch.h>
  21
  22 /* We keep an ordered array of offsets. */
  23 static bool append(tdb_off_t **arr, size_t *num, tdb_off_t off)
  24 {
  25         tdb_off_t *new = realloc(*arr, (*num + 1) * sizeof(tdb_off_t));
  26         if (!new)
  27                 return false;
  28         new[(*num)++] = off;
  29         *arr = new;
  30         return true;
  31 }
  32
  33 static bool check_header(struct tdb_context *tdb, tdb_off_t *recovery)
  34 {
  35         uint64_t hash_test;
  36         struct tdb_header hdr;
  37         enum TDB_ERROR ecode;
  38
  39         ecode = tdb_read_convert(tdb, 0, &hdr, sizeof(hdr));
  40         if (ecode != TDB_SUCCESS) {
  41                 tdb->ecode = ecode;
  42                 return false;
  43         }
  44         /* magic food should not be converted, so convert back. */
  45         tdb_convert(tdb, hdr.magic_food, sizeof(hdr.magic_food));
  46
  47         hash_test = TDB_HASH_MAGIC;
  48         hash_test = tdb_hash(tdb, &hash_test, sizeof(hash_test));
  49         if (hdr.hash_test != hash_test) {
  50                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
  51                            "check: hash test %llu should be %llu",
  52                            (long long)hdr.hash_test,
  53                            (long long)hash_test);
  54                 return false;
  55         }
  56
  57         if (strcmp(hdr.magic_food, TDB_MAGIC_FOOD) != 0) {
  58                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
  59                            "check: bad magic '%.*s'",
  60                            (unsigned)sizeof(hdr.magic_food), hdr.magic_food);
  61                 return false;
  62         }
  63
  64         *recovery = hdr.recovery;
  65         if (*recovery) {
  66                 if (*recovery < sizeof(hdr) || *recovery > tdb->map_size) {
  67                         tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
  68                                  "tdb_check: invalid recovery offset %zu",
  69                                  (size_t)*recovery);
  70                         return false;
  71                 }
  72         }
  73
  74         /* Don't check reserved: they *can* be used later. */
  75         return true;
  76 }
  77
  78 static bool check_hash_tree(struct tdb_context *tdb,
  79                             tdb_off_t off, unsigned int group_bits,
  80                             uint64_t hprefix,
  81                             unsigned hprefix_bits,
  82                             tdb_off_t used[],
  83                             size_t num_used,
  84                             size_t *num_found,
  85                             int (*check)(TDB_DATA, TDB_DATA, void *),
  86                             void *private_data);
  87
  88 static bool check_hash_chain(struct tdb_context *tdb,
  89                              tdb_off_t off,
  90                              uint64_t hash,
  91                              tdb_off_t used[],
  92                              size_t num_used,
  93                              size_t *num_found,
  94                              int (*check)(TDB_DATA, TDB_DATA, void *),
  95                              void *private_data)
  96 {
  97         struct tdb_used_record rec;
  98         enum TDB_ERROR ecode;
  99
 100         ecode = tdb_read_convert(tdb, off, &rec, sizeof(rec));
 101         if (ecode != TDB_SUCCESS) {
 102                 tdb->ecode = ecode;
 103                 return false;
 104         }
 105
 106         if (rec_magic(&rec) != TDB_CHAIN_MAGIC) {
 107                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 108                            "tdb_check: Bad hash chain magic %llu",
 109                            (long long)rec_magic(&rec));
 110                 return false;
 111         }
 112
 113         if (rec_data_length(&rec) != sizeof(struct tdb_chain)) {
 114                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 115                            "tdb_check: Bad hash chain length %llu vs %zu",
 116                            (long long)rec_data_length(&rec),
 117                            sizeof(struct tdb_chain));
 118                 return false;
 119         }
 120         if (rec_key_length(&rec) != 0) {
 121                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 122                          "tdb_check: Bad hash chain key length %llu",
 123                          (long long)rec_key_length(&rec));
 124                 return false;
 125         }
 126         if (rec_hash(&rec) != 0) {
 127                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 128                          "tdb_check: Bad hash chain hash value %llu",
 129                          (long long)rec_hash(&rec));
 130                 return false;
 131         }
 132
 133         off += sizeof(rec);
 134         if (!check_hash_tree(tdb, off, 0, hash, 64,
 135                              used, num_used, num_found, check, private_data))
 136                 return false;
 137
 138         off = tdb_read_off(tdb, off + offsetof(struct tdb_chain, next));
 139         if (off == TDB_OFF_ERR)
 140                 return false;
 141         if (off == 0)
 142                 return true;
 143         (*num_found)++;
 144         return check_hash_chain(tdb, off, hash, used, num_used, num_found,
 145                                 check, private_data);
 146 }
 147
 148 static bool check_hash_record(struct tdb_context *tdb,
 149                               tdb_off_t off,
 150                               uint64_t hprefix,
 151                               unsigned hprefix_bits,
 152                               tdb_off_t used[],
 153                               size_t num_used,
 154                               size_t *num_found,
 155                               int (*check)(TDB_DATA, TDB_DATA, void *),
 156                               void *private_data)
 157 {
 158         struct tdb_used_record rec;
 159         enum TDB_ERROR ecode;
 160
 161         if (hprefix_bits >= 64)
 162                 return check_hash_chain(tdb, off, hprefix, used, num_used,
 163                                         num_found, check, private_data);
 164
 165         ecode = tdb_read_convert(tdb, off, &rec, sizeof(rec));
 166         if (ecode != TDB_SUCCESS) {
 167                 tdb->ecode = ecode;
 168                 return false;
 169         }
 170
 171         if (rec_magic(&rec) != TDB_HTABLE_MAGIC) {
 172                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 173                            "tdb_check: Bad hash table magic %llu",
 174                            (long long)rec_magic(&rec));
 175                 return false;
 176         }
 177         if (rec_data_length(&rec)
 178             != sizeof(tdb_off_t) << TDB_SUBLEVEL_HASH_BITS) {
 179                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 180                            "tdb_check: Bad hash table length %llu vs %llu",
 181                            (long long)rec_data_length(&rec),
 182                            (long long)sizeof(tdb_off_t)
 183                            << TDB_SUBLEVEL_HASH_BITS);
 184                 return false;
 185         }
 186         if (rec_key_length(&rec) != 0) {
 187                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 188                          "tdb_check: Bad hash table key length %llu",
 189                          (long long)rec_key_length(&rec));
 190                 return false;
 191         }
 192         if (rec_hash(&rec) != 0) {
 193                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 194                          "tdb_check: Bad hash table hash value %llu",
 195                          (long long)rec_hash(&rec));
 196                 return false;
 197         }
 198
 199         off += sizeof(rec);
 200         return check_hash_tree(tdb, off,
 201                                TDB_SUBLEVEL_HASH_BITS-TDB_HASH_GROUP_BITS,
 202                                hprefix, hprefix_bits,
 203                                used, num_used, num_found, check, private_data);
 204 }
 205
 206 static int off_cmp(const tdb_off_t *a, const tdb_off_t *b)
 207 {
 208         /* Can overflow an int. */
 209         return *a > *b ? 1
 210                 : *a < *b ? -1
 211                 : 0;
 212 }
 213
 214 static uint64_t get_bits(uint64_t h, unsigned num, unsigned *used)
 215 {
 216         *used += num;
 217
 218         return (h >> (64 - *used)) & ((1U << num) - 1);
 219 }
 220
 221 static bool check_hash_tree(struct tdb_context *tdb,
 222                             tdb_off_t off, unsigned int group_bits,
 223                             uint64_t hprefix,
 224                             unsigned hprefix_bits,
 225                             tdb_off_t used[],
 226                             size_t num_used,
 227                             size_t *num_found,
 228                             int (*check)(TDB_DATA, TDB_DATA, void *),
 229                             void *private_data)
 230 {
 231         unsigned int g, b;
 232         const tdb_off_t *hash;
 233         struct tdb_used_record rec;
 234         enum TDB_ERROR ecode;
 235
 236         hash = tdb_access_read(tdb, off,
 237                                sizeof(tdb_off_t)
 238                                << (group_bits + TDB_HASH_GROUP_BITS),
 239                                true);
 240         if (TDB_PTR_IS_ERR(hash)) {
 241                 tdb->ecode = TDB_PTR_ERR(hash);
 242                 return false;
 243         }
 244
 245         for (g = 0; g < (1 << group_bits); g++) {
 246                 const tdb_off_t *group = hash + (g << TDB_HASH_GROUP_BITS);
 247                 for (b = 0; b < (1 << TDB_HASH_GROUP_BITS); b++) {
 248                         unsigned int bucket, i, used_bits;
 249                         uint64_t h;
 250                         tdb_off_t *p;
 251                         if (group[b] == 0)
 252                                 continue;
 253
 254                         off = group[b] & TDB_OFF_MASK;
 255                         p = asearch(&off, used, num_used, off_cmp);
 256                         if (!p) {
 257                                 tdb_logerr(tdb, TDB_ERR_CORRUPT,
 258                                            TDB_LOG_ERROR,
 259                                            "tdb_check: Invalid offset %llu "
 260                                            "in hash", (long long)off);
 261                                 goto fail;
 262                         }
 263                         /* Mark it invalid. */
 264                         *p ^= 1;
 265                         (*num_found)++;
 266
 267                         if (hprefix_bits == 64) {
 268                                 /* Chained entries are unordered. */
 269                                 if (is_subhash(group[b])) {
 270                                         tdb_logerr(tdb, TDB_ERR_CORRUPT,
 271                                                    TDB_LOG_ERROR,
 272                                                    "tdb_check: Invalid chain"
 273                                                    " entry subhash");
 274                                         goto fail;
 275                                 }
 276                                 h = hash_record(tdb, off);
 277                                 if (h != hprefix) {
 278                                         tdb_logerr(tdb, TDB_ERR_CORRUPT,
 279                                                    TDB_LOG_ERROR,
 280                                                    "check: bad hash chain"
 281                                                    " placement"
 282                                                    " 0x%llx vs 0x%llx",
 283                                                    (long long)h,
 284                                                    (long long)hprefix);
 285                                         goto fail;
 286                                 }
 287                                 ecode = tdb_read_convert(tdb, off, &rec,
 288                                                          sizeof(rec));
 289                                 if (ecode != TDB_SUCCESS) {
 290                                         tdb->ecode = ecode;
 291                                         goto fail;
 292                                 }
 293                                 goto check;
 294                         }
 295
 296                         if (is_subhash(group[b])) {
 297                                 uint64_t subprefix;
 298                                 subprefix = (hprefix
 299                                      << (group_bits + TDB_HASH_GROUP_BITS))
 300                                         + g * (1 << TDB_HASH_GROUP_BITS) + b;
 301
 302                                 if (!check_hash_record(tdb,
 303                                                group[b] & TDB_OFF_MASK,
 304                                                subprefix,
 305                                                hprefix_bits
 306                                                        + group_bits
 307                                                        + TDB_HASH_GROUP_BITS,
 308                                                used, num_used, num_found,
 309                                                check, private_data))
 310                                         goto fail;
 311                                 continue;
 312                         }
 313                         /* A normal entry */
 314
 315                         /* Does it belong here at all? */
 316                         h = hash_record(tdb, off);
 317                         used_bits = 0;
 318                         if (get_bits(h, hprefix_bits, &used_bits) != hprefix
 319                             && hprefix_bits) {
 320                                 tdb_logerr(tdb, TDB_ERR_CORRUPT,
 321                                            TDB_LOG_ERROR,
 322                                            "check: bad hash placement"
 323                                            " 0x%llx vs 0x%llx",
 324                                          (long long)h, (long long)hprefix);
 325                                 goto fail;
 326                         }
 327
 328                         /* Does it belong in this group? */
 329                         if (get_bits(h, group_bits, &used_bits) != g) {
 330                                 tdb_logerr(tdb, TDB_ERR_CORRUPT,
 331                                            TDB_LOG_ERROR,
 332                                            "check: bad group %llu vs %u",
 333                                            (long long)h, g);
 334                                 goto fail;
 335                         }
 336
 337                         /* Are bucket bits correct? */
 338                         bucket = group[b] & TDB_OFF_HASH_GROUP_MASK;
 339                         if (get_bits(h, TDB_HASH_GROUP_BITS, &used_bits)
 340                             != bucket) {
 341                                 used_bits -= TDB_HASH_GROUP_BITS;
 342                                 tdb_logerr(tdb, TDB_ERR_CORRUPT,
 343                                            TDB_LOG_ERROR,
 344                                          "check: bad bucket %u vs %u",
 345                                          (unsigned)get_bits(h,
 346                                                         TDB_HASH_GROUP_BITS,
 347                                                         &used_bits),
 348                                          bucket);
 349                                 goto fail;
 350                         }
 351
 352                         /* There must not be any zero entries between
 353                          * the bucket it belongs in and this one! */
 354                         for (i = bucket;
 355                              i != b;
 356                              i = (i + 1) % (1 << TDB_HASH_GROUP_BITS)) {
 357                                 if (group[i] == 0) {
 358                                         tdb_logerr(tdb, TDB_ERR_CORRUPT,
 359                                                    TDB_LOG_ERROR,
 360                                                    "check: bad group placement"
 361                                                    " %u vs %u",
 362                                                    b, bucket);
 363                                         goto fail;
 364                                 }
 365                         }
 366
 367                         ecode = tdb_read_convert(tdb, off, &rec, sizeof(rec));
 368                         if (ecode != TDB_SUCCESS) {
 369                                 tdb->ecode = ecode;
 370                                 goto fail;
 371                         }
 372
 373                         /* Bottom bits must match header. */
 374                         if ((h & ((1 << 11)-1)) != rec_hash(&rec)) {
 375                                 tdb_logerr(tdb, TDB_ERR_CORRUPT,
 376                                            TDB_LOG_ERROR,
 377                                            "tdb_check: Bad hash magic at"
 378                                            " offset %llu (0x%llx vs 0x%llx)",
 379                                            (long long)off,
 380                                            (long long)h,
 381                                            (long long)rec_hash(&rec));
 382                                 goto fail;
 383                         }
 384
 385                 check:
 386                         if (check) {
 387                                 TDB_DATA key, data;
 388                                 key.dsize = rec_key_length(&rec);
 389                                 data.dsize = rec_data_length(&rec);
 390                                 key.dptr = (void *)tdb_access_read(tdb,
 391                                                    off + sizeof(rec),
 392                                                    key.dsize + data.dsize,
 393                                                    false);
 394                                 if (TDB_PTR_IS_ERR(key.dptr)) {
 395                                         tdb->ecode = TDB_PTR_ERR(key.dptr);
 396                                         goto fail;
 397                                 }
 398                                 data.dptr = key.dptr + key.dsize;
 399                                 if (check(key, data, private_data) != 0)
 400                                         goto fail;
 401                                 tdb_access_release(tdb, key.dptr);
 402                         }
 403                 }
 404         }
 405         tdb_access_release(tdb, hash);
 406         return true;
 407
 408 fail:
 409         tdb_access_release(tdb, hash);
 410         return false;
 411 }
 412
 413 static bool check_hash(struct tdb_context *tdb,
 414                        tdb_off_t used[],
 415                        size_t num_used, size_t num_ftables,
 416                        int (*check)(TDB_DATA, TDB_DATA, void *),
 417                        void *private_data)
 418 {
 419         /* Free tables also show up as used. */
 420         size_t num_found = num_ftables;
 421
 422         if (!check_hash_tree(tdb, offsetof(struct tdb_header, hashtable),
 423                              TDB_TOPLEVEL_HASH_BITS-TDB_HASH_GROUP_BITS,
 424                              0, 0, used, num_used, &num_found,
 425                              check, private_data))
 426                 return false;
 427
 428         if (num_found != num_used) {
 429                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 430                            "tdb_check: Not all entries are in hash");
 431                 return false;
 432         }
 433         return true;
 434 }
 435
 436 static bool check_free(struct tdb_context *tdb,
 437                        tdb_off_t off,
 438                        const struct tdb_free_record *frec,
 439                        tdb_off_t prev, unsigned int ftable,
 440                        unsigned int bucket)
 441 {
 442         enum TDB_ERROR ecode;
 443
 444         if (frec_magic(frec) != TDB_FREE_MAGIC) {
 445                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 446                            "tdb_check: offset %llu bad magic 0x%llx",
 447                            (long long)off, (long long)frec->magic_and_prev);
 448                 return false;
 449         }
 450         if (frec_ftable(frec) != ftable) {
 451                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 452                            "tdb_check: offset %llu bad freetable %u",
 453                            (long long)off, frec_ftable(frec));
 454                 return false;
 455         }
 456
 457         ecode = tdb->methods->oob(tdb, off
 458                                   + frec_len(frec)
 459                                   + sizeof(struct tdb_used_record),
 460                                   false);
 461         if (ecode != TDB_SUCCESS) {
 462                 tdb->ecode = ecode;
 463                 return false;
 464         }
 465         if (size_to_bucket(frec_len(frec)) != bucket) {
 466                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 467                            "tdb_check: offset %llu in wrong bucket %u vs %u",
 468                            (long long)off,
 469                            bucket, size_to_bucket(frec_len(frec)));
 470                 return false;
 471         }
 472         if (prev != frec_prev(frec)) {
 473                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 474                            "tdb_check: offset %llu bad prev %llu vs %llu",
 475                            (long long)off,
 476                            (long long)prev, (long long)frec_len(frec));
 477                 return false;
 478         }
 479         return true;
 480 }
 481
 482 static bool check_free_table(struct tdb_context *tdb,
 483                              tdb_off_t ftable_off,
 484                              unsigned ftable_num,
 485                              tdb_off_t fr[],
 486                              size_t num_free,
 487                              size_t *num_found)
 488 {
 489         struct tdb_freetable ft;
 490         tdb_off_t h;
 491         unsigned int i;
 492         enum TDB_ERROR ecode;
 493
 494         ecode = tdb_read_convert(tdb, ftable_off, &ft, sizeof(ft));
 495         if (ecode != TDB_SUCCESS) {
 496                 tdb->ecode = ecode;
 497                 return false;
 498         }
 499
 500         if (rec_magic(&ft.hdr) != TDB_FTABLE_MAGIC
 501             || rec_key_length(&ft.hdr) != 0
 502             || rec_data_length(&ft.hdr) != sizeof(ft) - sizeof(ft.hdr)
 503             || rec_hash(&ft.hdr) != 0) {
 504                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 505                            "tdb_check: Invalid header on free table");
 506                 return false;
 507         }
 508
 509         for (i = 0; i < TDB_FREE_BUCKETS; i++) {
 510                 tdb_off_t off, prev = 0, *p;
 511                 struct tdb_free_record f;
 512
 513                 h = bucket_off(ftable_off, i);
 514                 for (off = tdb_read_off(tdb, h); off; off = f.next) {
 515                         if (off == TDB_OFF_ERR)
 516                                 return false;
 517                         ecode = tdb_read_convert(tdb, off, &f, sizeof(f));
 518                         if (ecode != TDB_SUCCESS) {
 519                                 tdb->ecode = ecode;
 520                                 return false;
 521                         }
 522                         if (!check_free(tdb, off, &f, prev, ftable_num, i))
 523                                 return false;
 524
 525                         /* FIXME: Check hash bits */
 526                         p = asearch(&off, fr, num_free, off_cmp);
 527                         if (!p) {
 528                                 tdb_logerr(tdb, TDB_ERR_CORRUPT,
 529                                            TDB_LOG_ERROR,
 530                                            "tdb_check: Invalid offset"
 531                                            " %llu in free table",
 532                                            (long long)off);
 533                                 return false;
 534                         }
 535                         /* Mark it invalid. */
 536                         *p ^= 1;
 537                         (*num_found)++;
 538                         prev = off;
 539                 }
 540         }
 541         return true;
 542 }
 543
 544 /* Slow, but should be very rare. */
 545 size_t dead_space(struct tdb_context *tdb, tdb_off_t off)
 546 {
 547         size_t len;
 548         enum TDB_ERROR ecode;
 549
 550         for (len = 0; off + len < tdb->map_size; len++) {
 551                 char c;
 552                 ecode = tdb->methods->tread(tdb, off, &c, 1);
 553                 if (ecode != TDB_SUCCESS) {
 554                         tdb->ecode = ecode;
 555                         return 0;
 556                 }
 557                 if (c != 0 && c != 0x43)
 558                         break;
 559         }
 560         return len;
 561 }
 562
 563 static bool check_linear(struct tdb_context *tdb,
 564                          tdb_off_t **used, size_t *num_used,
 565                          tdb_off_t **fr, size_t *num_free,
 566                          tdb_off_t recovery)
 567 {
 568         tdb_off_t off;
 569         tdb_len_t len;
 570         enum TDB_ERROR ecode;
 571         bool found_recovery = false;
 572
 573         for (off = sizeof(struct tdb_header); off < tdb->map_size; off += len) {
 574                 union {
 575                         struct tdb_used_record u;
 576                         struct tdb_free_record f;
 577                         struct tdb_recovery_record r;
 578                 } rec;
 579                 /* r is larger: only get that if we need to. */
 580                 ecode = tdb_read_convert(tdb, off, &rec, sizeof(rec.f));
 581                 if (ecode != TDB_SUCCESS) {
 582                         tdb->ecode = ecode;
 583                         return false;
 584                 }
 585
 586                 /* If we crash after ftruncate, we can get zeroes or fill. */
 587                 if (rec.r.magic == TDB_RECOVERY_INVALID_MAGIC
 588                     || rec.r.magic ==  0x4343434343434343ULL) {
 589                         ecode = tdb_read_convert(tdb, off, &rec, sizeof(rec.r));
 590                         if (ecode != TDB_SUCCESS) {
 591                                 tdb->ecode = ecode;
 592                                 return false;
 593                         }
 594                         if (recovery == off) {
 595                                 found_recovery = true;
 596                                 len = sizeof(rec.r) + rec.r.max_len;
 597                         } else {
 598                                 len = dead_space(tdb, off);
 599                                 if (len < sizeof(rec.r)) {
 600                                         tdb_logerr(tdb, TDB_ERR_CORRUPT,
 601                                                    TDB_LOG_ERROR,
 602                                                    "tdb_check: invalid dead"
 603                                                    " space at %zu",
 604                                                    (size_t)off);
 605                                         return false;
 606                                 }
 607
 608                                 tdb_logerr(tdb, TDB_SUCCESS, TDB_LOG_WARNING,
 609                                            "Dead space at %zu-%zu (of %zu)",
 610                                            (size_t)off, (size_t)(off + len),
 611                                            (size_t)tdb->map_size);
 612                         }
 613                 } else if (rec.r.magic == TDB_RECOVERY_MAGIC) {
 614                         ecode = tdb_read_convert(tdb, off, &rec, sizeof(rec.r));
 615                         if (ecode != TDB_SUCCESS) {
 616                                 tdb->ecode = ecode;
 617                                 return false;
 618                         }
 619                         if (recovery != off) {
 620                                 tdb_logerr(tdb, TDB_ERR_CORRUPT,
 621                                            TDB_LOG_ERROR,
 622                                            "tdb_check: unexpected recovery"
 623                                            " record at offset %zu",
 624                                            (size_t)off);
 625                                 return false;
 626                         }
 627                         if (rec.r.len > rec.r.max_len) {
 628                                 tdb_logerr(tdb, TDB_ERR_CORRUPT,
 629                                            TDB_LOG_ERROR,
 630                                            "tdb_check: invalid recovery length"
 631                                            " %zu", (size_t)rec.r.len);
 632                                 return false;
 633                         }
 634                         if (rec.r.eof > tdb->map_size) {
 635                                 tdb_logerr(tdb, TDB_ERR_CORRUPT,
 636                                            TDB_LOG_ERROR,
 637                                            "tdb_check: invalid old EOF"
 638                                            " %zu", (size_t)rec.r.eof);
 639                                 return false;
 640                         }
 641                         found_recovery = true;
 642                         len = sizeof(rec.r) + rec.r.max_len;
 643                 } else if (frec_magic(&rec.f) == TDB_FREE_MAGIC) {
 644                         len = sizeof(rec.u) + frec_len(&rec.f);
 645                         if (off + len > tdb->map_size) {
 646                                 tdb_logerr(tdb, TDB_ERR_CORRUPT,
 647                                            TDB_LOG_ERROR,
 648                                            "tdb_check: free overlength %llu"
 649                                            " at offset %llu",
 650                                            (long long)len, (long long)off);
 651                                 return false;
 652                         }
 653                         /* This record should be in free lists. */
 654                         if (frec_ftable(&rec.f) != TDB_FTABLE_NONE
 655                             && !append(fr, num_free, off)) {
 656                                 tdb_logerr(tdb, TDB_ERR_OOM,
 657                                            TDB_LOG_ERROR,
 658                                            "tdb_check: tracking %zu'th"
 659                                            " free record.", *num_free);
 660                                 return false;
 661                         }
 662                 } else if (rec_magic(&rec.u) == TDB_USED_MAGIC
 663                            || rec_magic(&rec.u) == TDB_CHAIN_MAGIC
 664                            || rec_magic(&rec.u) == TDB_HTABLE_MAGIC
 665                            || rec_magic(&rec.u) == TDB_FTABLE_MAGIC) {
 666                         uint64_t klen, dlen, extra;
 667
 668                         /* This record is used! */
 669                         if (!append(used, num_used, off)) {
 670                                 tdb_logerr(tdb, TDB_ERR_OOM,
 671                                            TDB_LOG_ERROR,
 672                                            "tdb_check: tracking %zu'th"
 673                                            " used record.", *num_used);
 674                                 return false;
 675                         }
 676
 677                         klen = rec_key_length(&rec.u);
 678                         dlen = rec_data_length(&rec.u);
 679                         extra = rec_extra_padding(&rec.u);
 680
 681                         len = sizeof(rec.u) + klen + dlen + extra;
 682                         if (off + len > tdb->map_size) {
 683                                 tdb_logerr(tdb, TDB_ERR_CORRUPT,
 684                                            TDB_LOG_ERROR,
 685                                            "tdb_check: used overlength %llu"
 686                                            " at offset %llu",
 687                                            (long long)len, (long long)off);
 688                                 return false;
 689                         }
 690
 691                         if (len < sizeof(rec.f)) {
 692                                 tdb_logerr(tdb, TDB_ERR_CORRUPT,
 693                                            TDB_LOG_ERROR,
 694                                            "tdb_check: too short record %llu"
 695                                            " at %llu",
 696                                            (long long)len, (long long)off);
 697                                 return false;
 698                         }
 699                 } else {
 700                         tdb_logerr(tdb, TDB_ERR_CORRUPT,
 701                                    TDB_LOG_ERROR,
 702                                    "tdb_check: Bad magic 0x%llx at offset %zu",
 703                                    (long long)rec_magic(&rec.u), (size_t)off);
 704                         return false;
 705                 }
 706         }
 707
 708         /* We must have found recovery area if there was one. */
 709         if (recovery != 0 && !found_recovery) {
 710                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 711                            "tdb_check: expected a recovery area at %zu",
 712                            (size_t)recovery);
 713                 return false;
 714         }
 715
 716         return true;
 717 }
 718
 719 int tdb_check(struct tdb_context *tdb,
 720               int (*check)(TDB_DATA key, TDB_DATA data, void *private_data),
 721               void *private_data)
 722 {
 723         tdb_off_t *fr = NULL, *used = NULL, ft, recovery;
 724         size_t num_free = 0, num_used = 0, num_found = 0, num_ftables = 0;
 725         enum TDB_ERROR ecode;
 726
 727         ecode = tdb_allrecord_lock(tdb, F_RDLCK, TDB_LOCK_WAIT, false);
 728         if (ecpde != TDB_SUCCESS) {
 729                 tdb->ecode = ecode;
 730                 return -1;
 731         }
 732
 733         ecode = tdb_lock_expand(tdb, F_RDLCK);
 734         if (ecode != TDB_SUCCESS) {
 735                 tdb->ecode = ecode;
 736                 tdb_allrecord_unlock(tdb, F_RDLCK);
 737                 return -1;
 738         }
 739
 740         if (!check_header(tdb, &recovery))
 741                 goto fail;
 742
 743         /* First we do a linear scan, checking all records. */
 744         if (!check_linear(tdb, &used, &num_used, &fr, &num_free, recovery))
 745                 goto fail;
 746
 747         for (ft = first_ftable(tdb); ft; ft = next_ftable(tdb, ft)) {
 748                 if (ft == TDB_OFF_ERR)
 749                         goto fail;
 750                 if (!check_free_table(tdb, ft, num_ftables, fr, num_free,
 751                                       &num_found))
 752                         goto fail;
 753                 num_ftables++;
 754         }
 755
 756         /* FIXME: Check key uniqueness? */
 757         if (!check_hash(tdb, used, num_used, num_ftables, check, private_data))
 758                 goto fail;
 759
 760         if (num_found != num_free) {
 761                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 762                            "tdb_check: Not all entries are in free table");
 763                 return -1;
 764         }
 765
 766         tdb_allrecord_unlock(tdb, F_RDLCK);
 767         tdb_unlock_expand(tdb, F_RDLCK);
 768         free(fr);
 769         free(used);
 770         return 0;
 771
 772 fail:
 773         free(fr);
 774         free(used);
 775         tdb_allrecord_unlock(tdb, F_RDLCK);
 776         tdb_unlock_expand(tdb, F_RDLCK);
 777         return -1;
 778 }