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   1 /*
   2  * lookup_table.c
   3  *
   4  * Lookup table, implemented as a hash table, that maps SHA1 message digests to
   5  * data streams.
   6  */
   7
   8 /*
   9  * Copyright (C) 2012, 2013 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 wim_lookup_table *
  37 new_lookup_table(size_t capacity)
  38 {
  39         struct wim_lookup_table *table;
  40         struct hlist_head *array;
  41
  42         table = MALLOC(sizeof(struct wim_lookup_table));
  43         if (table) {
  44                 array = CALLOC(capacity, sizeof(array[0]));
  45                 if (array) {
  46                         table->num_entries = 0;
  47                         table->capacity = capacity;
  48                         table->array = array;
  49                 } else {
  50                         FREE(table);
  51                         table = NULL;
  52                         ERROR("Failed to allocate memory for lookup table with capacity %zu",
  53                               capacity);
  54                 }
  55         }
  56         return table;
  57 }
  58
  59 struct wim_lookup_table_entry *
  60 new_lookup_table_entry()
  61 {
  62         struct wim_lookup_table_entry *lte;
  63
  64         lte = CALLOC(1, sizeof(struct wim_lookup_table_entry));
  65         if (lte) {
  66                 lte->part_number  = 1;
  67                 lte->refcnt       = 1;
  68         } else {
  69                 ERROR("Out of memory (tried to allocate %zu bytes for "
  70                       "lookup table entry)",
  71                       sizeof(struct wim_lookup_table_entry));
  72         }
  73         return lte;
  74 }
  75
  76 struct wim_lookup_table_entry *
  77 clone_lookup_table_entry(const struct wim_lookup_table_entry *old)
  78 {
  79         struct wim_lookup_table_entry *new;
  80
  81         new = MALLOC(sizeof(*new));
  82         if (!new)
  83                 return NULL;
  84
  85         memcpy(new, old, sizeof(*old));
  86         new->extracted_file = NULL;
  87         switch (new->resource_location) {
  88 #ifdef __WIN32__
  89         case RESOURCE_WIN32:
  90 #endif
  91         case RESOURCE_IN_STAGING_FILE:
  92         case RESOURCE_IN_FILE_ON_DISK:
  93                 BUILD_BUG_ON((void*)&old->file_on_disk !=
  94                              (void*)&old->staging_file_name);
  95                 new->staging_file_name = TSTRDUP(old->staging_file_name);
  96                 if (!new->staging_file_name)
  97                         goto out_free;
  98                 break;
  99         case RESOURCE_IN_ATTACHED_BUFFER:
 100                 new->attached_buffer = MALLOC(wim_resource_size(old));
 101                 if (!new->attached_buffer)
 102                         goto out_free;
 103                 memcpy(new->attached_buffer, old->attached_buffer,
 104                        wim_resource_size(old));
 105                 break;
 106 #ifdef WITH_NTFS_3G
 107         case RESOURCE_IN_NTFS_VOLUME:
 108                 if (old->ntfs_loc) {
 109                         struct ntfs_location *loc;
 110                         loc = MALLOC(sizeof(*loc));
 111                         if (!loc)
 112                                 goto out_free;
 113                         memcpy(loc, old->ntfs_loc, sizeof(*loc));
 114                         loc->path = NULL;
 115                         loc->stream_name = NULL;
 116                         new->ntfs_loc = loc;
 117                         loc->path = STRDUP(old->ntfs_loc->path);
 118                         if (!loc->path)
 119                                 goto out_free;
 120                         loc->stream_name = MALLOC((loc->stream_name_nchars + 1) * 2);
 121                         if (!loc->stream_name)
 122                                 goto out_free;
 123                         memcpy(loc->stream_name,
 124                                old->ntfs_loc->stream_name,
 125                                (loc->stream_name_nchars + 1) * 2);
 126                 }
 127                 break;
 128 #endif
 129         default:
 130                 break;
 131         }
 132         return new;
 133 out_free:
 134         free_lookup_table_entry(new);
 135         return NULL;
 136 }
 137
 138 void
 139 free_lookup_table_entry(struct wim_lookup_table_entry *lte)
 140 {
 141         if (lte) {
 142                 switch (lte->resource_location) {
 143                 case RESOURCE_IN_STAGING_FILE:
 144                 case RESOURCE_IN_ATTACHED_BUFFER:
 145                 case RESOURCE_IN_FILE_ON_DISK:
 146 #ifdef __WIN32__
 147                 case RESOURCE_WIN32:
 148 #endif
 149                         BUILD_BUG_ON((void*)&lte->file_on_disk !=
 150                                      (void*)&lte->staging_file_name);
 151                         BUILD_BUG_ON((void*)&lte->file_on_disk !=
 152                                      (void*)&lte->attached_buffer);
 153                         FREE(lte->file_on_disk);
 154                         break;
 155 #ifdef WITH_NTFS_3G
 156                 case RESOURCE_IN_NTFS_VOLUME:
 157                         if (lte->ntfs_loc) {
 158                                 FREE(lte->ntfs_loc->path);
 159                                 FREE(lte->ntfs_loc->stream_name);
 160                                 FREE(lte->ntfs_loc);
 161                         }
 162                         break;
 163 #endif
 164                 default:
 165                         break;
 166                 }
 167                 FREE(lte);
 168         }
 169 }
 170
 171 static int
 172 do_free_lookup_table_entry(struct wim_lookup_table_entry *entry, void *ignore)
 173 {
 174         free_lookup_table_entry(entry);
 175         return 0;
 176 }
 177
 178
 179 void
 180 free_lookup_table(struct wim_lookup_table *table)
 181 {
 182         DEBUG2("Freeing lookup table");
 183         if (table) {
 184                 if (table->array) {
 185                         for_lookup_table_entry(table,
 186                                                do_free_lookup_table_entry,
 187                                                NULL);
 188                         FREE(table->array);
 189                 }
 190                 FREE(table);
 191         }
 192 }
 193
 194 /*
 195  * Inserts an entry into the lookup table.
 196  *
 197  * @table:      A pointer to the lookup table.
 198  * @lte:        A pointer to the entry to insert.
 199  */
 200 void
 201 lookup_table_insert(struct wim_lookup_table *table,
 202                     struct wim_lookup_table_entry *lte)
 203 {
 204         size_t i = lte->hash_short % table->capacity;
 205         hlist_add_head(&lte->hash_list, &table->array[i]);
 206
 207         /* XXX Make the table grow when too many entries have been inserted. */
 208         table->num_entries++;
 209 }
 210
 211 static void
 212 finalize_lte(struct wim_lookup_table_entry *lte)
 213 {
 214         #ifdef WITH_FUSE
 215         if (lte->resource_location == RESOURCE_IN_STAGING_FILE) {
 216                 unlink(lte->staging_file_name);
 217                 list_del(&lte->staging_list);
 218         }
 219         #endif
 220         free_lookup_table_entry(lte);
 221 }
 222
 223 /* Decrements the reference count for the lookup table entry @lte.  If its
 224  * reference count reaches 0, it is unlinked from the lookup table.  If,
 225  * furthermore, the entry has no opened file descriptors associated with it, the
 226  * entry is freed.  */
 227 void
 228 lte_decrement_refcnt(struct wim_lookup_table_entry *lte,
 229                      struct wim_lookup_table *table)
 230 {
 231         wimlib_assert(lte != NULL);
 232         wimlib_assert(lte->refcnt != 0);
 233         if (--lte->refcnt == 0) {
 234                 lookup_table_unlink(table, lte);
 235         #ifdef WITH_FUSE
 236                 if (lte->num_opened_fds == 0)
 237         #endif
 238                         finalize_lte(lte);
 239         }
 240 }
 241
 242 #ifdef WITH_FUSE
 243 void
 244 lte_decrement_num_opened_fds(struct wim_lookup_table_entry *lte)
 245 {
 246         if (lte->num_opened_fds != 0)
 247                 if (--lte->num_opened_fds == 0 && lte->refcnt == 0)
 248                         finalize_lte(lte);
 249 }
 250 #endif
 251
 252 /* Calls a function on all the entries in the WIM lookup table.  Stop early and
 253  * return nonzero if any call to the function returns nonzero. */
 254 int
 255 for_lookup_table_entry(struct wim_lookup_table *table,
 256                        int (*visitor)(struct wim_lookup_table_entry *, void *),
 257                        void *arg)
 258 {
 259         struct wim_lookup_table_entry *lte;
 260         struct hlist_node *pos, *tmp;
 261         int ret;
 262
 263         for (size_t i = 0; i < table->capacity; i++) {
 264                 hlist_for_each_entry_safe(lte, pos, tmp, &table->array[i],
 265                                           hash_list)
 266                 {
 267                         ret = visitor(lte, arg);
 268                         if (ret != 0)
 269                                 return ret;
 270                 }
 271         }
 272         return 0;
 273 }
 274
 275
 276 /*
 277  * Reads the lookup table from a WIM file.
 278  */
 279 int
 280 read_lookup_table(WIMStruct *w)
 281 {
 282         u64 num_entries;
 283         u8 buf[WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE];
 284         int ret;
 285         struct wim_lookup_table *table;
 286         struct wim_lookup_table_entry *cur_entry = NULL, *duplicate_entry;
 287
 288         if (resource_is_compressed(&w->hdr.lookup_table_res_entry)) {
 289                 ERROR("Didn't expect a compressed lookup table!");
 290                 ERROR("Ask the author to implement support for this.");
 291                 return WIMLIB_ERR_COMPRESSED_LOOKUP_TABLE;
 292         }
 293
 294         DEBUG("Reading lookup table: offset %"PRIu64", size %"PRIu64"",
 295               w->hdr.lookup_table_res_entry.offset,
 296               w->hdr.lookup_table_res_entry.original_size);
 297
 298         if (fseeko(w->fp, w->hdr.lookup_table_res_entry.offset, SEEK_SET) != 0)
 299         {
 300                 ERROR_WITH_ERRNO("Failed to seek to byte %"PRIu64" to read "
 301                                  "lookup table",
 302                                  w->hdr.lookup_table_res_entry.offset);
 303                 return WIMLIB_ERR_READ;
 304         }
 305
 306         num_entries = w->hdr.lookup_table_res_entry.original_size /
 307                       WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE;
 308         table = new_lookup_table(num_entries * 2 + 1);
 309         if (!table)
 310                 return WIMLIB_ERR_NOMEM;
 311
 312         while (num_entries--) {
 313                 const u8 *p;
 314
 315                 if (fread(buf, 1, sizeof(buf), w->fp) != sizeof(buf)) {
 316                         if (feof(w->fp)) {
 317                                 ERROR("Unexpected EOF in WIM lookup table!");
 318                         } else {
 319                                 ERROR_WITH_ERRNO("Error reading WIM lookup "
 320                                                  "table");
 321                         }
 322                         ret = WIMLIB_ERR_READ;
 323                         goto out;
 324                 }
 325                 cur_entry = new_lookup_table_entry();
 326                 if (!cur_entry) {
 327                         ret = WIMLIB_ERR_NOMEM;
 328                         goto out;
 329                 }
 330                 cur_entry->wim = w;
 331                 cur_entry->resource_location = RESOURCE_IN_WIM;
 332
 333                 p = get_resource_entry(buf, &cur_entry->resource_entry);
 334                 p = get_u16(p, &cur_entry->part_number);
 335                 p = get_u32(p, &cur_entry->refcnt);
 336                 p = get_bytes(p, SHA1_HASH_SIZE, cur_entry->hash);
 337
 338                 if (cur_entry->part_number != w->hdr.part_number) {
 339                         ERROR("A lookup table entry in part %hu of the WIM "
 340                               "points to part %hu",
 341                               w->hdr.part_number, cur_entry->part_number);
 342                         ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
 343                         goto out_free_cur_entry;
 344                 }
 345
 346                 if (is_zero_hash(cur_entry->hash)) {
 347                         ERROR("The WIM lookup table contains an entry with a "
 348                               "SHA1 message digest of all 0's");
 349                         ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
 350                         goto out_free_cur_entry;
 351                 }
 352
 353                 /* Ordinarily, no two streams should share the same SHA1 message
 354                  * digest.  However, this constraint can be broken for metadata
 355                  * resources--- two identical images will have the same metadata
 356                  * resource, but their lookup table entries are not shared. */
 357                 duplicate_entry = __lookup_resource(table, cur_entry->hash);
 358                 if (duplicate_entry
 359                     && !((duplicate_entry->resource_entry.flags & WIM_RESHDR_FLAG_METADATA)
 360                           && cur_entry->resource_entry.flags & WIM_RESHDR_FLAG_METADATA))
 361                 {
 362                 #ifdef ENABLE_ERROR_MESSAGES
 363                         ERROR("The WIM lookup table contains two entries with the "
 364                               "same SHA1 message digest!");
 365                         ERROR("The first entry is:");
 366                         print_lookup_table_entry(duplicate_entry, stderr);
 367                         ERROR("The second entry is:");
 368                         print_lookup_table_entry(cur_entry, stderr);
 369                 #endif
 370                         ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
 371                         goto out_free_cur_entry;
 372                 }
 373
 374                 if (!(cur_entry->resource_entry.flags & WIM_RESHDR_FLAG_COMPRESSED)
 375                     && (cur_entry->resource_entry.size !=
 376                         cur_entry->resource_entry.original_size))
 377                 {
 378                 #ifdef ENABLE_ERROR_MESSAGES
 379                         ERROR("Found uncompressed resource with original size "
 380                               "not the same as compressed size");
 381                         ERROR("The lookup table entry for the resource is as follows:");
 382                         print_lookup_table_entry(cur_entry, stderr);
 383                 #endif
 384                         ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
 385                         goto out_free_cur_entry;
 386                 }
 387                 if ((cur_entry->resource_entry.flags & WIM_RESHDR_FLAG_METADATA)
 388                     && cur_entry->refcnt != 1)
 389                 {
 390                 #ifdef ENABLE_ERROR_MESSAGES
 391                         ERROR("Found metadata resource with refcnt != 1:");
 392                         print_lookup_table_entry(cur_entry, stderr);
 393                 #endif
 394                         ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
 395                         goto out_free_cur_entry;
 396                 }
 397                 lookup_table_insert(table, cur_entry);
 398
 399         }
 400         DEBUG("Done reading lookup table.");
 401         w->lookup_table = table;
 402         return 0;
 403 out_free_cur_entry:
 404         FREE(cur_entry);
 405 out:
 406         free_lookup_table(table);
 407         return ret;
 408 }
 409
 410
 411 /*
 412  * Writes a lookup table entry to the output file.
 413  */
 414 int
 415 write_lookup_table_entry(struct wim_lookup_table_entry *lte, void *__out)
 416 {
 417         FILE *out;
 418         u8 buf[WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE];
 419         u8 *p;
 420
 421         out = __out;
 422
 423         /* Don't write entries that have not had file resources or metadata
 424          * resources written for them. */
 425         if (lte->out_refcnt == 0)
 426                 return 0;
 427
 428         if (lte->output_resource_entry.flags & WIM_RESHDR_FLAG_METADATA) {
 429                 DEBUG("Writing metadata entry at %"PRIu64" "
 430                       "(orig size = %"PRIu64")",
 431                       ftello(out), lte->output_resource_entry.original_size);
 432         }
 433
 434         p = put_resource_entry(buf, &lte->output_resource_entry);
 435         p = put_u16(p, lte->part_number);
 436         p = put_u32(p, lte->out_refcnt);
 437         p = put_bytes(p, SHA1_HASH_SIZE, lte->hash);
 438         if (fwrite(buf, 1, sizeof(buf), out) != sizeof(buf)) {
 439                 ERROR_WITH_ERRNO("Failed to write lookup table entry");
 440                 return WIMLIB_ERR_WRITE;
 441         }
 442         return 0;
 443 }
 444
 445 /* Writes the lookup table to the output file. */
 446 int
 447 write_lookup_table(struct wim_lookup_table *table, FILE *out,
 448                    struct resource_entry *out_res_entry)
 449 {
 450         off_t start_offset, end_offset;
 451         int ret;
 452
 453         start_offset = ftello(out);
 454         if (start_offset == -1)
 455                 return WIMLIB_ERR_WRITE;
 456
 457         ret = for_lookup_table_entry(table, write_lookup_table_entry, out);
 458         if (ret != 0)
 459                 return ret;
 460
 461         end_offset = ftello(out);
 462         if (end_offset == -1)
 463                 return WIMLIB_ERR_WRITE;
 464
 465         out_res_entry->offset        = start_offset;
 466         out_res_entry->size          = end_offset - start_offset;
 467         out_res_entry->original_size = end_offset - start_offset;
 468         out_res_entry->flags         = WIM_RESHDR_FLAG_METADATA;
 469
 470         return 0;
 471 }
 472
 473
 474 int
 475 lte_zero_real_refcnt(struct wim_lookup_table_entry *lte, void *ignore)
 476 {
 477         lte->real_refcnt = 0;
 478         return 0;
 479 }
 480
 481 int
 482 lte_zero_out_refcnt(struct wim_lookup_table_entry *lte, void *ignore)
 483 {
 484         lte->out_refcnt = 0;
 485         return 0;
 486 }
 487
 488 int
 489 lte_free_extracted_file(struct wim_lookup_table_entry *lte, void *ignore)
 490 {
 491         if (lte->extracted_file != NULL) {
 492                 FREE(lte->extracted_file);
 493                 lte->extracted_file = NULL;
 494         }
 495         return 0;
 496 }
 497
 498 void
 499 print_lookup_table_entry(const struct wim_lookup_table_entry *lte, FILE *out)
 500 {
 501         if (!lte) {
 502                 tputc(T('\n'), out);
 503                 return;
 504         }
 505         tfprintf(out, T("Offset            = %"PRIu64" bytes\n"),
 506                  lte->resource_entry.offset);
 507
 508         tfprintf(out, T("Size              = %"PRIu64" bytes\n"),
 509                  (u64)lte->resource_entry.size);
 510
 511         tfprintf(out, T("Original size     = %"PRIu64" bytes\n"),
 512                  lte->resource_entry.original_size);
 513
 514         tfprintf(out, T("Part Number       = %hu\n"), lte->part_number);
 515         tfprintf(out, T("Reference Count   = %u\n"), lte->refcnt);
 516
 517         tfprintf(out, T("Hash              = 0x"));
 518         print_hash(lte->hash);
 519         tputc(T('\n'), out);
 520
 521         tfprintf(out, T("Flags             = "));
 522         u8 flags = lte->resource_entry.flags;
 523         if (flags & WIM_RESHDR_FLAG_COMPRESSED)
 524                 tfputs(T("WIM_RESHDR_FLAG_COMPRESSED, "), out);
 525         if (flags & WIM_RESHDR_FLAG_FREE)
 526                 tfputs(T("WIM_RESHDR_FLAG_FREE, "), out);
 527         if (flags & WIM_RESHDR_FLAG_METADATA)
 528                 tfputs(T("WIM_RESHDR_FLAG_METADATA, "), out);
 529         if (flags & WIM_RESHDR_FLAG_SPANNED)
 530                 tfputs(T("WIM_RESHDR_FLAG_SPANNED, "), out);
 531         tputc(T('\n'), out);
 532         switch (lte->resource_location) {
 533         case RESOURCE_IN_WIM:
 534                 if (lte->wim->filename) {
 535                         tfprintf(out, T("WIM file          = `%"TS"'\n"),
 536                                  lte->wim->filename);
 537                 }
 538                 break;
 539 #ifdef __WIN32__
 540         case RESOURCE_WIN32:
 541 #endif
 542         case RESOURCE_IN_FILE_ON_DISK:
 543                 tfprintf(out, T("File on Disk      = `%"TS"'\n"),
 544                          lte->file_on_disk);
 545                 break;
 546         case RESOURCE_IN_STAGING_FILE:
 547                 tfprintf(out, T("Staging File      = `%"TS"'\n"),
 548                                 lte->staging_file_name);
 549                 break;
 550         default:
 551                 break;
 552         }
 553         tputc(T('\n'), out);
 554 }
 555
 556 static int
 557 do_print_lookup_table_entry(struct wim_lookup_table_entry *lte, void *fp)
 558 {
 559         print_lookup_table_entry(lte, (FILE*)fp);
 560         return 0;
 561 }
 562
 563 /*
 564  * Prints the lookup table of a WIM file.
 565  */
 566 WIMLIBAPI void
 567 wimlib_print_lookup_table(WIMStruct *w)
 568 {
 569         for_lookup_table_entry(w->lookup_table,
 570                                do_print_lookup_table_entry,
 571                                stdout);
 572 }
 573
 574 /* Given a SHA1 message digest, return the corresponding entry in the WIM's
 575  * lookup table, or NULL if there is none.  */
 576 struct wim_lookup_table_entry *
 577 __lookup_resource(const struct wim_lookup_table *table, const u8 hash[])
 578 {
 579         size_t i;
 580         struct wim_lookup_table_entry *lte;
 581         struct hlist_node *pos;
 582
 583         wimlib_assert(table != NULL);
 584         wimlib_assert(hash != NULL);
 585
 586         i = *(size_t*)hash % table->capacity;
 587         hlist_for_each_entry(lte, pos, &table->array[i], hash_list)
 588                 if (hashes_equal(hash, lte->hash))
 589                         return lte;
 590         return NULL;
 591 }
 592
 593 #ifdef WITH_FUSE
 594 /*
 595  * Finds the dentry, lookup table entry, and stream index for a WIM file stream,
 596  * given a path name.
 597  *
 598  * This is only for pre-resolved inodes.
 599  */
 600 int
 601 lookup_resource(WIMStruct *w,
 602                 const tchar *path,
 603                 int lookup_flags,
 604                 struct wim_dentry **dentry_ret,
 605                 struct wim_lookup_table_entry **lte_ret,
 606                 u16 *stream_idx_ret)
 607 {
 608         struct wim_dentry *dentry;
 609         struct wim_lookup_table_entry *lte;
 610         u16 stream_idx;
 611         const tchar *stream_name = NULL;
 612         struct wim_inode *inode;
 613         tchar *p = NULL;
 614
 615         if (lookup_flags & LOOKUP_FLAG_ADS_OK) {
 616                 stream_name = path_stream_name(path);
 617                 if (stream_name) {
 618                         p = (tchar*)stream_name - 1;
 619                         *p = T('\0');
 620                 }
 621         }
 622
 623         dentry = get_dentry(w, path);
 624         if (p)
 625                 *p = T(':');
 626         if (!dentry)
 627                 return -errno;
 628
 629         inode = dentry->d_inode;
 630
 631         wimlib_assert(inode->i_resolved);
 632
 633         if (!(lookup_flags & LOOKUP_FLAG_DIRECTORY_OK)
 634               && inode_is_directory(inode))
 635                 return -EISDIR;
 636
 637         if (stream_name) {
 638                 struct wim_ads_entry *ads_entry;
 639                 u16 ads_idx;
 640                 ads_entry = inode_get_ads_entry(inode, stream_name,
 641                                                 &ads_idx);
 642                 if (ads_entry) {
 643                         stream_idx = ads_idx + 1;
 644                         lte = ads_entry->lte;
 645                         goto out;
 646                 } else {
 647                         return -ENOENT;
 648                 }
 649         } else {
 650                 lte = inode->i_lte;
 651                 stream_idx = 0;
 652         }
 653 out:
 654         if (dentry_ret)
 655                 *dentry_ret = dentry;
 656         if (lte_ret)
 657                 *lte_ret = lte;
 658         if (stream_idx_ret)
 659                 *stream_idx_ret = stream_idx;
 660         return 0;
 661 }
 662 #endif
 663
 664 /* Resolve an inode's lookup table entries
 665  *
 666  * This replaces the SHA1 hash fields (which are used to lookup an entry in the
 667  * lookup table) with pointers directly to the lookup table entries.  A circular
 668  * linked list of streams sharing the same lookup table entry is created.
 669  *
 670  * This function always succeeds; unresolved lookup table entries are given a
 671  * NULL pointer.
 672  */
 673 void
 674 inode_resolve_ltes(struct wim_inode *inode, struct wim_lookup_table *table)
 675 {
 676
 677         if (!inode->i_resolved) {
 678                 struct wim_lookup_table_entry *lte;
 679                 /* Resolve the default file stream */
 680                 lte = __lookup_resource(table, inode->i_hash);
 681                 inode->i_lte = lte;
 682                 inode->i_resolved = 1;
 683
 684                 /* Resolve the alternate data streams */
 685                 for (u16 i = 0; i < inode->i_num_ads; i++) {
 686                         struct wim_ads_entry *cur_entry = &inode->i_ads_entries[i];
 687                         lte = __lookup_resource(table, cur_entry->hash);
 688                         cur_entry->lte = lte;
 689                 }
 690         }
 691 }
 692
 693 void
 694 inode_unresolve_ltes(struct wim_inode *inode)
 695 {
 696         if (inode->i_resolved) {
 697                 if (inode->i_lte)
 698                         copy_hash(inode->i_hash, inode->i_lte->hash);
 699                 else
 700                         zero_out_hash(inode->i_hash);
 701
 702                 for (u16 i = 0; i < inode->i_num_ads; i++) {
 703                         if (inode->i_ads_entries[i].lte)
 704                                 copy_hash(inode->i_ads_entries[i].hash,
 705                                           inode->i_ads_entries[i].lte->hash);
 706                         else
 707                                 zero_out_hash(inode->i_ads_entries[i].hash);
 708                 }
 709                 inode->i_resolved = 0;
 710         }
 711 }
 712
 713 /*
 714  * Returns the lookup table entry for stream @stream_idx of the inode, where
 715  * stream_idx = 0 means the default un-named file stream, and stream_idx >= 1
 716  * corresponds to an alternate data stream.
 717  *
 718  * This works for both resolved and un-resolved inodes.
 719  */
 720 struct wim_lookup_table_entry *
 721 inode_stream_lte(const struct wim_inode *inode, unsigned stream_idx,
 722                  const struct wim_lookup_table *table)
 723 {
 724         if (inode->i_resolved)
 725                 return inode_stream_lte_resolved(inode, stream_idx);
 726         else
 727                 return inode_stream_lte_unresolved(inode, stream_idx, table);
 728 }
 729
 730
 731 /* Return the lookup table entry for the unnamed data stream of an inode, or
 732  * NULL if there is none.
 733  *
 734  * You'd think this would be easier than it actually is, since the unnamed data
 735  * stream should be the one referenced from the inode itself.  Alas, if there
 736  * are named data streams, Microsoft's "imagex.exe" program will put the unnamed
 737  * data stream in one of the alternate data streams instead of inside the WIM
 738  * dentry itself.  So we need to check the alternate data streams too.
 739  *
 740  * Also, note that a dentry may appear to have more than one unnamed stream, but
 741  * if the SHA1 message digest is all 0's then the corresponding stream does not
 742  * really "count" (this is the case for the inode's own file stream when the
 743  * file stream that should be there is actually in one of the alternate stream
 744  * entries.).  This is despite the fact that we may need to extract such a
 745  * missing entry as an empty file or empty named data stream.
 746  */
 747 struct wim_lookup_table_entry *
 748 inode_unnamed_lte(const struct wim_inode *inode,
 749                   const struct wim_lookup_table *table)
 750 {
 751         if (inode->i_resolved)
 752                 return inode_unnamed_lte_resolved(inode);
 753         else
 754                 return inode_unnamed_lte_unresolved(inode, table);
 755 }
 756
 757 static int
 758 lte_add_stream_size(struct wim_lookup_table_entry *lte, void *total_bytes_p)
 759 {
 760         *(u64*)total_bytes_p += lte->resource_entry.size;
 761         return 0;
 762 }
 763
 764 u64
 765 lookup_table_total_stream_size(struct wim_lookup_table *table)
 766 {
 767         u64 total_size = 0;
 768         for_lookup_table_entry(table, lte_add_stream_size, &total_size);
 769         return total_size;
 770 }