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