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   1 /*
   2  * lookup_table.c
   3  *
   4  * Lookup table, implemented as a hash table, that maps dentries to file
   5  * resources.
   6  */
   7
   8 /*
   9  * Copyright (C) 2012 Eric Biggers
  10  *
  11  * This file is part of wimlib, a library for working with WIM files.
  12  *
  13  * wimlib is free software; you can redistribute it and/or modify it under the
  14  * terms of the GNU General Public License as published by the Free
  15  * Software Foundation; either version 3 of the License, or (at your option)
  16  * any later version.
  17  *
  18  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
  19  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  20  * A PARTICULAR PURPOSE. See the GNU General Public License for more
  21  * details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with wimlib; if not, see http://www.gnu.org/licenses/.
  25  */
  26
  27 #include "wimlib_internal.h"
  28 #include "lookup_table.h"
  29 #include "buffer_io.h"
  30 #include <errno.h>
  31
  32 #ifdef WITH_FUSE
  33 #include <unistd.h>
  34 #endif
  35
  36 struct lookup_table *new_lookup_table(size_t capacity)
  37 {
  38         struct lookup_table *table;
  39         struct hlist_head *array;
  40
  41         table = MALLOC(sizeof(struct lookup_table));
  42         if (table) {
  43                 array = CALLOC(capacity, sizeof(array[0]));
  44                 if (array) {
  45                         table->num_entries = 0;
  46                         table->capacity = capacity;
  47                         table->array = array;
  48                 } else {
  49                         FREE(table);
  50                         table = NULL;
  51                         ERROR("Failed to allocate memory for lookup table with capacity %zu",
  52                               capacity);
  53                 }
  54         }
  55         return table;
  56 }
  57
  58 struct lookup_table_entry *new_lookup_table_entry()
  59 {
  60         struct lookup_table_entry *lte;
  61
  62         lte = CALLOC(1, sizeof(struct lookup_table_entry));
  63         if (lte) {
  64                 lte->part_number  = 1;
  65                 lte->refcnt       = 1;
  66         } else {
  67                 ERROR("Out of memory (tried to allocate %zu bytes for "
  68                       "lookup table entry)",
  69                       sizeof(struct lookup_table_entry));
  70         }
  71         return lte;
  72 }
  73
  74 struct lookup_table_entry *
  75 clone_lookup_table_entry(const struct lookup_table_entry *old)
  76 {
  77         struct lookup_table_entry *new;
  78
  79         new = MALLOC(sizeof(*new));
  80         if (!new)
  81                 return NULL;
  82
  83         memcpy(new, old, sizeof(*old));
  84         new->extracted_file = NULL;
  85         switch (new->resource_location) {
  86         case RESOURCE_IN_STAGING_FILE:
  87         case RESOURCE_IN_FILE_ON_DISK:
  88                 wimlib_assert((void*)&old->file_on_disk ==
  89                               (void*)&old->staging_file_name);
  90                 new->staging_file_name = STRDUP(old->staging_file_name);
  91                 if (!new->staging_file_name)
  92                         goto out_free;
  93                 break;
  94         case RESOURCE_IN_ATTACHED_BUFFER:
  95                 new->attached_buffer = MALLOC(wim_resource_size(old));
  96                 if (!new->attached_buffer)
  97                         goto out_free;
  98                 memcpy(new->attached_buffer, old->attached_buffer,
  99                        wim_resource_size(old));
 100                 break;
 101 #ifdef WITH_NTFS_3G
 102         case RESOURCE_IN_NTFS_VOLUME:
 103                 if (old->ntfs_loc) {
 104                         struct ntfs_location *loc;
 105                         loc = MALLOC(sizeof(*loc));
 106                         if (!loc)
 107                                 goto out_free;
 108                         memcpy(loc, old->ntfs_loc, sizeof(*loc));
 109                         loc->path_utf8 = NULL;
 110                         loc->stream_name_utf16 = NULL;
 111                         new->ntfs_loc = loc;
 112                         loc->path_utf8 = STRDUP(old->ntfs_loc->path_utf8);
 113                         if (!loc->path_utf8)
 114                                 goto out_free;
 115                         loc->stream_name_utf16 = MALLOC(loc->stream_name_utf16_num_chars * 2);
 116                         if (!loc->stream_name_utf16)
 117                                 goto out_free;
 118                         memcpy(loc->stream_name_utf16,
 119                                old->ntfs_loc->stream_name_utf16,
 120                                loc->stream_name_utf16_num_chars * 2);
 121                 }
 122                 break;
 123 #endif
 124         default:
 125                 break;
 126         }
 127         return new;
 128 out_free:
 129         free_lookup_table_entry(new);
 130         return NULL;
 131 }
 132
 133 void free_lookup_table_entry(struct lookup_table_entry *lte)
 134 {
 135         if (lte) {
 136                 switch (lte->resource_location) {
 137                 case RESOURCE_IN_STAGING_FILE:
 138                 case RESOURCE_IN_ATTACHED_BUFFER:
 139                 case RESOURCE_IN_FILE_ON_DISK:
 140                         wimlib_assert(((void*)&lte->file_on_disk ==
 141                                       (void*)&lte->staging_file_name)
 142                                       && ((void*)&lte->file_on_disk ==
 143                                       (void*)&lte->attached_buffer));
 144                         FREE(lte->file_on_disk);
 145                         break;
 146 #ifdef WITH_NTFS_3G
 147                 case RESOURCE_IN_NTFS_VOLUME:
 148                         if (lte->ntfs_loc) {
 149                                 FREE(lte->ntfs_loc->path_utf8);
 150                                 FREE(lte->ntfs_loc->stream_name_utf16);
 151                                 FREE(lte->ntfs_loc);
 152                         }
 153                         break;
 154 #endif
 155                 default:
 156                         break;
 157                 }
 158                 FREE(lte);
 159         }
 160 }
 161
 162 static int do_free_lookup_table_entry(struct lookup_table_entry *entry,
 163                                       void *ignore)
 164 {
 165         free_lookup_table_entry(entry);
 166         return 0;
 167 }
 168
 169
 170 void free_lookup_table(struct lookup_table *table)
 171 {
 172         DEBUG2("Freeing lookup table");
 173         if (table) {
 174                 if (table->array) {
 175                         for_lookup_table_entry(table,
 176                                                do_free_lookup_table_entry,
 177                                                NULL);
 178                         FREE(table->array);
 179                 }
 180                 FREE(table);
 181         }
 182 }
 183
 184 /*
 185  * Inserts an entry into the lookup table.
 186  *
 187  * @table:      A pointer to the lookup table.
 188  * @entry:      A pointer to the entry to insert.
 189  */
 190 void lookup_table_insert(struct lookup_table *table,
 191                          struct lookup_table_entry *lte)
 192 {
 193         size_t i = lte->hash_short % table->capacity;
 194         hlist_add_head(&lte->hash_list, &table->array[i]);
 195
 196         /* XXX Make the table grow when too many entries have been inserted. */
 197         table->num_entries++;
 198 }
 199
 200 static void finalize_lte(struct lookup_table_entry *lte)
 201 {
 202         #ifdef WITH_FUSE
 203         if (lte->resource_location == RESOURCE_IN_STAGING_FILE) {
 204                 unlink(lte->staging_file_name);
 205                 wimlib_assert(lte->staging_list.next);
 206                 wimlib_assert(lte->staging_list.prev);
 207                 list_del(&lte->staging_list);
 208         }
 209         #endif
 210         free_lookup_table_entry(lte);
 211 }
 212
 213 /* Decrements the reference count for the lookup table entry @lte.  If its
 214  * reference count reaches 0, it is unlinked from the lookup table.  If,
 215  * furthermore, the entry has no opened file descriptors associated with it, the
 216  * entry is freed.  */
 217 void lte_decrement_refcnt(struct lookup_table_entry *lte,
 218                           struct lookup_table *table)
 219 {
 220         wimlib_assert(lte != NULL);
 221         wimlib_assert(lte->refcnt != 0);
 222         if (--lte->refcnt == 0) {
 223                 lookup_table_unlink(table, lte);
 224         #ifdef WITH_FUSE
 225                 if (lte->num_opened_fds == 0)
 226         #endif
 227                         finalize_lte(lte);
 228         }
 229 }
 230
 231 #ifdef WITH_FUSE
 232 void lte_decrement_num_opened_fds(struct lookup_table_entry *lte)
 233 {
 234         wimlib_assert(lte != NULL);
 235         if (lte->num_opened_fds != 0) {
 236                 if (--lte->num_opened_fds == 0 && lte->refcnt == 0)
 237                         finalize_lte(lte);
 238         }
 239 }
 240 #endif
 241
 242 /*
 243  * Calls a function on all the entries in the lookup table.  Stop early and
 244  * return nonzero if any call to the function returns nonzero.
 245  */
 246 int for_lookup_table_entry(struct lookup_table *table,
 247                            int (*visitor)(struct lookup_table_entry *, void *),
 248                            void *arg)
 249 {
 250         struct lookup_table_entry *lte;
 251         struct hlist_node *pos, *tmp;
 252         int ret;
 253
 254         for (size_t i = 0; i < table->capacity; i++) {
 255                 hlist_for_each_entry_safe(lte, pos, tmp, &table->array[i],
 256                                           hash_list)
 257                 {
 258                         ret = visitor(lte, arg);
 259                         if (ret != 0)
 260                                 return ret;
 261                 }
 262         }
 263         return 0;
 264 }
 265
 266
 267 /*
 268  * Reads the lookup table from a WIM file.
 269  */
 270 int read_lookup_table(WIMStruct *w)
 271 {
 272         u64 num_entries;
 273         u8 buf[WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE];
 274         int ret;
 275         struct lookup_table *table;
 276         struct lookup_table_entry *cur_entry = NULL, *duplicate_entry;
 277
 278         if (resource_is_compressed(&w->hdr.lookup_table_res_entry)) {
 279                 ERROR("Didn't expect a compressed lookup table!");
 280                 ERROR("Ask the author to implement support for this.");
 281                 return WIMLIB_ERR_COMPRESSED_LOOKUP_TABLE;
 282         }
 283
 284         DEBUG("Reading lookup table: offset %"PRIu64", size %"PRIu64"",
 285               w->hdr.lookup_table_res_entry.offset,
 286               w->hdr.lookup_table_res_entry.original_size);
 287
 288         if (fseeko(w->fp, w->hdr.lookup_table_res_entry.offset, SEEK_SET) != 0)
 289         {
 290                 ERROR_WITH_ERRNO("Failed to seek to byte %"PRIu64" to read "
 291                                  "lookup table",
 292                                  w->hdr.lookup_table_res_entry.offset);
 293                 return WIMLIB_ERR_READ;
 294         }
 295
 296         num_entries = w->hdr.lookup_table_res_entry.original_size /
 297                       WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE;
 298         table = new_lookup_table(num_entries * 2 + 1);
 299         if (!table)
 300                 return WIMLIB_ERR_NOMEM;
 301
 302         while (num_entries--) {
 303                 const u8 *p;
 304
 305                 if (fread(buf, 1, sizeof(buf), w->fp) != sizeof(buf)) {
 306                         if (feof(w->fp)) {
 307                                 ERROR("Unexpected EOF in WIM lookup table!");
 308                         } else {
 309                                 ERROR_WITH_ERRNO("Error reading WIM lookup "
 310                                                  "table");
 311                         }
 312                         ret = WIMLIB_ERR_READ;
 313                         goto out;
 314                 }
 315                 cur_entry = new_lookup_table_entry();
 316                 if (!cur_entry) {
 317                         ret = WIMLIB_ERR_NOMEM;
 318                         goto out;
 319                 }
 320                 cur_entry->wim = w;
 321                 cur_entry->resource_location = RESOURCE_IN_WIM;
 322
 323                 p = get_resource_entry(buf, &cur_entry->resource_entry);
 324                 p = get_u16(p, &cur_entry->part_number);
 325                 p = get_u32(p, &cur_entry->refcnt);
 326                 p = get_bytes(p, SHA1_HASH_SIZE, cur_entry->hash);
 327
 328                 if (cur_entry->part_number != w->hdr.part_number) {
 329                         ERROR("A lookup table entry in part %hu of the WIM "
 330                               "points to part %hu",
 331                               w->hdr.part_number, cur_entry->part_number);
 332                         ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
 333                         goto out_free_cur_entry;
 334                 }
 335
 336                 if (is_zero_hash(cur_entry->hash)) {
 337                         ERROR("The WIM lookup table contains an entry with a "
 338                               "SHA1 message digest of all 0's");
 339                         ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
 340                         goto out_free_cur_entry;
 341                 }
 342
 343                 /* Ordinarily, no two streams should share the same SHA1 message
 344                  * digest.  However, this constraint can be broken for metadata
 345                  * resources--- two identical images will have the same metadata
 346                  * resource, but their lookup table entries are not shared. */
 347                 duplicate_entry = __lookup_resource(table, cur_entry->hash);
 348                 if (duplicate_entry
 349                     && !((duplicate_entry->resource_entry.flags & WIM_RESHDR_FLAG_METADATA)
 350                           && cur_entry->resource_entry.flags & WIM_RESHDR_FLAG_METADATA))
 351                 {
 352                         ERROR("The WIM lookup table contains two entries with the "
 353                               "same SHA1 message digest!");
 354                         ERROR("The first entry is:");
 355                         print_lookup_table_entry(duplicate_entry);
 356                         ERROR("The second entry is:");
 357                         print_lookup_table_entry(cur_entry);
 358                         ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
 359                         goto out_free_cur_entry;
 360                 }
 361
 362                 if (!(cur_entry->resource_entry.flags & WIM_RESHDR_FLAG_COMPRESSED)
 363                     && (cur_entry->resource_entry.size !=
 364                         cur_entry->resource_entry.original_size))
 365                 {
 366                         ERROR("Found uncompressed resource with original size "
 367                               "not the same as compressed size");
 368                         ERROR("The lookup table entry for the resource is as follows:");
 369                         print_lookup_table_entry(cur_entry);
 370                         ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
 371                         goto out_free_cur_entry;
 372                 }
 373                 if ((cur_entry->resource_entry.flags & WIM_RESHDR_FLAG_METADATA)
 374                     && cur_entry->refcnt != 1)
 375                 {
 376                         ERROR("Found metadata resource with refcnt != 1:");
 377                         print_lookup_table_entry(cur_entry);
 378                         ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
 379                         goto out_free_cur_entry;
 380                 }
 381                 lookup_table_insert(table, cur_entry);
 382
 383         }
 384         DEBUG("Done reading lookup table.");
 385         w->lookup_table = table;
 386         return 0;
 387 out_free_cur_entry:
 388         FREE(cur_entry);
 389 out:
 390         free_lookup_table(table);
 391         return ret;
 392 }
 393
 394
 395 /*
 396  * Writes a lookup table entry to the output file.
 397  */
 398 int write_lookup_table_entry(struct lookup_table_entry *lte, void *__out)
 399 {
 400         FILE *out;
 401         u8 buf[WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE];
 402         u8 *p;
 403
 404         out = __out;
 405
 406         /* Don't write entries that have not had file resources or metadata
 407          * resources written for them. */
 408         if (lte->out_refcnt == 0)
 409                 return 0;
 410
 411         if (lte->output_resource_entry.flags & WIM_RESHDR_FLAG_METADATA)
 412                 DEBUG("Writing metadata entry at %lu (orig size = %zu)",
 413                       ftello(out), lte->output_resource_entry.original_size);
 414
 415         p = put_resource_entry(buf, &lte->output_resource_entry);
 416         p = put_u16(p, lte->part_number);
 417         p = put_u32(p, lte->out_refcnt);
 418         p = put_bytes(p, SHA1_HASH_SIZE, lte->hash);
 419         if (fwrite(buf, 1, sizeof(buf), out) != sizeof(buf)) {
 420                 ERROR_WITH_ERRNO("Failed to write lookup table entry");
 421                 return WIMLIB_ERR_WRITE;
 422         }
 423         return 0;
 424 }
 425
 426 /* Writes the lookup table to the output file. */
 427 int write_lookup_table(struct lookup_table *table, FILE *out,
 428                        struct resource_entry *out_res_entry)
 429 {
 430         off_t start_offset, end_offset;
 431         int ret;
 432
 433         start_offset = ftello(out);
 434         if (start_offset == -1)
 435                 return WIMLIB_ERR_WRITE;
 436
 437         ret = for_lookup_table_entry(table, write_lookup_table_entry, out);
 438         if (ret != 0)
 439                 return ret;
 440
 441         end_offset = ftello(out);
 442         if (end_offset == -1)
 443                 return WIMLIB_ERR_WRITE;
 444
 445         out_res_entry->offset        = start_offset;
 446         out_res_entry->size          = end_offset - start_offset;
 447         out_res_entry->original_size = end_offset - start_offset;
 448         out_res_entry->flags         = WIM_RESHDR_FLAG_METADATA;
 449
 450         return 0;
 451 }
 452
 453
 454 int lte_zero_real_refcnt(struct lookup_table_entry *lte, void *ignore)
 455 {
 456         lte->real_refcnt = 0;
 457         return 0;
 458 }
 459
 460 int lte_zero_out_refcnt(struct lookup_table_entry *lte, void *ignore)
 461 {
 462         lte->out_refcnt = 0;
 463         return 0;
 464 }
 465
 466 int lte_zero_extracted_file(struct lookup_table_entry *lte, void *ignore)
 467 {
 468         lte->extracted_file = NULL;
 469         return 0;
 470 }
 471
 472 int lte_free_extracted_file(struct lookup_table_entry *lte, void *ignore)
 473 {
 474         if (lte->extracted_file != NULL) {
 475                 FREE(lte->extracted_file);
 476                 lte->extracted_file = NULL;
 477         }
 478         return 0;
 479 }
 480
 481 void print_lookup_table_entry(const struct lookup_table_entry *lte)
 482 {
 483         if (!lte) {
 484                 putchar('\n');
 485                 return;
 486         }
 487         printf("Offset            = %"PRIu64" bytes\n",
 488                lte->resource_entry.offset);
 489         printf("Size              = %"PRIu64" bytes\n",
 490                (u64)lte->resource_entry.size);
 491         printf("Original size     = %"PRIu64" bytes\n",
 492                lte->resource_entry.original_size);
 493         printf("Part Number       = %hu\n", lte->part_number);
 494         printf("Reference Count   = %u\n", lte->refcnt);
 495         printf("Hash              = 0x");
 496         print_hash(lte->hash);
 497         putchar('\n');
 498         printf("Flags             = ");
 499         u8 flags = lte->resource_entry.flags;
 500         if (flags & WIM_RESHDR_FLAG_COMPRESSED)
 501                 fputs("WIM_RESHDR_FLAG_COMPRESSED, ", stdout);
 502         if (flags & WIM_RESHDR_FLAG_FREE)
 503                 fputs("WIM_RESHDR_FLAG_FREE, ", stdout);
 504         if (flags & WIM_RESHDR_FLAG_METADATA)
 505                 fputs("WIM_RESHDR_FLAG_METADATA, ", stdout);
 506         if (flags & WIM_RESHDR_FLAG_SPANNED)
 507                 fputs("WIM_RESHDR_FLAG_SPANNED, ", stdout);
 508         putchar('\n');
 509         switch (lte->resource_location) {
 510         case RESOURCE_IN_WIM:
 511                 if (lte->wim->filename) {
 512                         printf("WIM file          = `%s'\n",
 513                                lte->wim->filename);
 514                 }
 515                 break;
 516         case RESOURCE_IN_FILE_ON_DISK:
 517                 printf("File on Disk      = `%s'\n", lte->file_on_disk);
 518                 break;
 519         case RESOURCE_IN_STAGING_FILE:
 520                 printf("Staging File      = `%s'\n", lte->staging_file_name);
 521                 break;
 522         default:
 523                 break;
 524         }
 525         putchar('\n');
 526 }
 527
 528 static int do_print_lookup_table_entry(struct lookup_table_entry *lte,
 529                                        void *ignore)
 530 {
 531         print_lookup_table_entry(lte);
 532         return 0;
 533 }
 534
 535 /*
 536  * Prints the lookup table of a WIM file.
 537  */
 538 WIMLIBAPI void wimlib_print_lookup_table(WIMStruct *w)
 539 {
 540         for_lookup_table_entry(w->lookup_table,
 541                                do_print_lookup_table_entry,
 542                                NULL);
 543 }
 544
 545 /*
 546  * Looks up an entry in the lookup table.
 547  */
 548 struct lookup_table_entry *
 549 __lookup_resource(const struct lookup_table *table, const u8 hash[])
 550 {
 551         size_t i;
 552         struct lookup_table_entry *lte;
 553         struct hlist_node *pos;
 554
 555         wimlib_assert(table != NULL);
 556         wimlib_assert(hash != NULL);
 557
 558         i = *(size_t*)hash % table->capacity;
 559         hlist_for_each_entry(lte, pos, &table->array[i], hash_list)
 560                 if (hashes_equal(hash, lte->hash))
 561                         return lte;
 562         return NULL;
 563 }
 564
 565 #ifdef WITH_FUSE
 566 /*
 567  * Finds the dentry, lookup table entry, and stream index for a WIM file stream,
 568  * given a path name.
 569  *
 570  * This is only for pre-resolved inodes.
 571  */
 572 int lookup_resource(WIMStruct *w, const char *path,
 573                     int lookup_flags,
 574                     struct dentry **dentry_ret,
 575                     struct lookup_table_entry **lte_ret,
 576                     u16 *stream_idx_ret)
 577 {
 578         struct dentry *dentry;
 579         struct lookup_table_entry *lte;
 580         u16 stream_idx;
 581         const char *stream_name = NULL;
 582         struct inode *inode;
 583         char *p = NULL;
 584
 585         if (lookup_flags & LOOKUP_FLAG_ADS_OK) {
 586                 stream_name = path_stream_name(path);
 587                 if (stream_name) {
 588                         p = (char*)stream_name - 1;
 589                         *p = '\0';
 590                 }
 591         }
 592
 593         dentry = get_dentry(w, path);
 594         if (p)
 595                 *p = ':';
 596         if (!dentry)
 597                 return -ENOENT;
 598
 599         inode = dentry->d_inode;
 600
 601         wimlib_assert(inode->resolved);
 602
 603         if (!(lookup_flags & LOOKUP_FLAG_DIRECTORY_OK)
 604               && inode_is_directory(inode))
 605                 return -EISDIR;
 606
 607         if (stream_name) {
 608                 struct ads_entry *ads_entry;
 609                 u16 ads_idx;
 610                 ads_entry = inode_get_ads_entry(inode, stream_name,
 611                                                 &ads_idx);
 612                 if (ads_entry) {
 613                         stream_idx = ads_idx + 1;
 614                         lte = ads_entry->lte;
 615                         goto out;
 616                 } else {
 617                         return -ENOENT;
 618                 }
 619         } else {
 620                 lte = inode->lte;
 621                 stream_idx = 0;
 622         }
 623 out:
 624         if (dentry_ret)
 625                 *dentry_ret = dentry;
 626         if (lte_ret)
 627                 *lte_ret = lte;
 628         if (stream_idx_ret)
 629                 *stream_idx_ret = stream_idx;
 630         return 0;
 631 }
 632 #endif
 633
 634 void inode_resolve_ltes(struct inode *inode, struct lookup_table *table)
 635 {
 636         struct lookup_table_entry *lte;
 637
 638         wimlib_assert(!inode->resolved);
 639
 640         /* Resolve the default file stream */
 641         lte = __lookup_resource(table, inode->hash);
 642         inode->lte = lte;
 643         inode->resolved = true;
 644
 645         /* Resolve the alternate data streams */
 646         for (u16 i = 0; i < inode->num_ads; i++) {
 647                 struct ads_entry *cur_entry = &inode->ads_entries[i];
 648                 lte = __lookup_resource(table, cur_entry->hash);
 649                 cur_entry->lte = lte;
 650         }
 651 }
 652
 653 static void inode_unresolve_ltes(struct inode *inode)
 654 {
 655         wimlib_assert(inode->resolved);
 656         if (inode->lte)
 657                 copy_hash(inode->hash, inode->lte->hash);
 658         else
 659                 zero_out_hash(inode->hash);
 660
 661         for (u16 i = 0; i < inode->num_ads; i++) {
 662                 if (inode->ads_entries[i].lte)
 663                         copy_hash(inode->ads_entries[i].hash,
 664                                   inode->ads_entries[i].lte->hash);
 665                 else
 666                         zero_out_hash(inode->ads_entries[i].hash);
 667         }
 668         inode->resolved = false;
 669 }
 670
 671 /* Resolve a dentry's lookup table entries
 672  *
 673  * This replaces the SHA1 hash fields (which are used to lookup an entry in the
 674  * lookup table) with pointers directly to the lookup table entries.  A circular
 675  * linked list of streams sharing the same lookup table entry is created.
 676  *
 677  * This function always succeeds; unresolved lookup table entries are given a
 678  * NULL pointer.
 679  */
 680 int dentry_resolve_ltes(struct dentry *dentry, void *table)
 681 {
 682         if (!dentry->d_inode->resolved)
 683                 inode_resolve_ltes(dentry->d_inode, table);
 684         return 0;
 685 }
 686
 687 int dentry_unresolve_ltes(struct dentry *dentry, void *ignore)
 688 {
 689         if (dentry->d_inode->resolved)
 690                 inode_unresolve_ltes(dentry->d_inode);
 691         return 0;
 692 }
 693
 694 /*
 695  * Returns the lookup table entry for stream @stream_idx of the inode, where
 696  * stream_idx = 0 means the default un-named file stream, and stream_idx >= 1
 697  * corresponds to an alternate data stream.
 698  *
 699  * This works for both resolved and un-resolved dentries.
 700  */
 701 struct lookup_table_entry *
 702 inode_stream_lte(const struct inode *inode, unsigned stream_idx,
 703                  const struct lookup_table *table)
 704 {
 705         if (inode->resolved)
 706                 return inode_stream_lte_resolved(inode, stream_idx);
 707         else
 708                 return inode_stream_lte_unresolved(inode, stream_idx, table);
 709 }
 710
 711
 712 /* Return the lookup table entry for the unnamed data stream of an inode, or
 713  * NULL if there is none.
 714  *
 715  * You'd think this would be easier than it actually is, since the unnamed data
 716  * stream should be the one referenced from the inode itself.  Alas, if there
 717  * are named data streams, Microsoft's "imagex.exe" program will put the unnamed
 718  * data stream in one of the alternate data streams instead of inside the WIM
 719  * dentry itself.  So we need to check the alternate data streams too.
 720  *
 721  * Also, note that a dentry may appear to have more than one unnamed stream, but
 722  * if the SHA1 message digest is all 0's then the corresponding stream does not
 723  * really "count" (this is the case for the inode's own file stream when the
 724  * file stream that should be there is actually in one of the alternate stream
 725  * entries.).  This is despite the fact that we may need to extract such a
 726  * missing entry as an empty file or empty named data stream.
 727  */
 728 struct lookup_table_entry *
 729 inode_unnamed_lte(const struct inode *inode,
 730                   const struct lookup_table *table)
 731 {
 732         if (inode->resolved)
 733                 return inode_unnamed_lte_resolved(inode);
 734         else
 735                 return inode_unnamed_lte_unresolved(inode, table);
 736 }
 737
 738 static int lte_add_stream_size(struct lookup_table_entry *lte,
 739                                void *total_bytes_p)
 740 {
 741         *(u64*)total_bytes_p += lte->resource_entry.size;
 742         return 0;
 743 }
 744
 745 u64 lookup_table_total_stream_size(struct lookup_table *table)
 746 {
 747         u64 total_size = 0;
 748         for_lookup_table_entry(table, lte_add_stream_size, &total_size);
 749         return total_size;
 750 }