wimlib.net Git - wimlib/blob - src/lookup_table.c

   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 *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 #ifdef __WIN32__
  88         case RESOURCE_WIN32:
  89                 {
  90                         size_t nbytes = utf16le_strlen(old->win32_file_on_disk);
  91                         new->win32_file_on_disk = MALLOC(nbytes + 2);
  92                         if (!new->win32_file_on_disk)
  93                                 goto out_free;
  94                         memcpy(new->win32_file_on_disk, old->win32_file_on_disk,
  95                                nbytes + 2);
  96                 }
  97                 break;
  98 #endif
  99         case RESOURCE_IN_STAGING_FILE:
 100         case RESOURCE_IN_FILE_ON_DISK:
 101                 BUILD_BUG_ON((void*)&old->file_on_disk !=
 102                              (void*)&old->staging_file_name);
 103                 new->staging_file_name = STRDUP(old->staging_file_name);
 104                 if (!new->staging_file_name)
 105                         goto out_free;
 106                 break;
 107         case RESOURCE_IN_ATTACHED_BUFFER:
 108                 new->attached_buffer = MALLOC(wim_resource_size(old));
 109                 if (!new->attached_buffer)
 110                         goto out_free;
 111                 memcpy(new->attached_buffer, old->attached_buffer,
 112                        wim_resource_size(old));
 113                 break;
 114 #ifdef WITH_NTFS_3G
 115         case RESOURCE_IN_NTFS_VOLUME:
 116                 if (old->ntfs_loc) {
 117                         struct ntfs_location *loc;
 118                         loc = MALLOC(sizeof(*loc));
 119                         if (!loc)
 120                                 goto out_free;
 121                         memcpy(loc, old->ntfs_loc, sizeof(*loc));
 122                         loc->path = NULL;
 123                         loc->stream_name = NULL;
 124                         new->ntfs_loc = loc;
 125                         loc->path = STRDUP(old->ntfs_loc->path);
 126                         if (!loc->path)
 127                                 goto out_free;
 128                         loc->stream_name = MALLOC((loc->stream_name_nchars + 1) * 2);
 129                         if (!loc->stream_name)
 130                                 goto out_free;
 131                         memcpy(loc->stream_name,
 132                                old->ntfs_loc->stream_name,
 133                                (loc->stream_name_nchars + 1) * 2);
 134                 }
 135                 break;
 136 #endif
 137         default:
 138                 break;
 139         }
 140         return new;
 141 out_free:
 142         free_lookup_table_entry(new);
 143         return NULL;
 144 }
 145
 146 void free_lookup_table_entry(struct wim_lookup_table_entry *lte)
 147 {
 148         if (lte) {
 149                 switch (lte->resource_location) {
 150                 case RESOURCE_IN_STAGING_FILE:
 151                 case RESOURCE_IN_ATTACHED_BUFFER:
 152                 case RESOURCE_IN_FILE_ON_DISK:
 153 #ifdef __WIN32__
 154                 case RESOURCE_WIN32:
 155 #endif
 156                         BUILD_BUG_ON((void*)&lte->file_on_disk !=
 157                                      (void*)&lte->staging_file_name);
 158                         BUILD_BUG_ON((void*)&lte->file_on_disk !=
 159                                      (void*)&lte->attached_buffer);
 160                         FREE(lte->file_on_disk);
 161                         break;
 162 #ifdef WITH_NTFS_3G
 163                 case RESOURCE_IN_NTFS_VOLUME:
 164                         if (lte->ntfs_loc) {
 165                                 FREE(lte->ntfs_loc->path);
 166                                 FREE(lte->ntfs_loc->stream_name);
 167                                 FREE(lte->ntfs_loc);
 168                         }
 169                         break;
 170 #endif
 171                 default:
 172                         break;
 173                 }
 174                 FREE(lte);
 175         }
 176 }
 177
 178 static int do_free_lookup_table_entry(struct wim_lookup_table_entry *entry,
 179                                       void *ignore)
 180 {
 181         free_lookup_table_entry(entry);
 182         return 0;
 183 }
 184
 185
 186 void free_lookup_table(struct wim_lookup_table *table)
 187 {
 188         DEBUG2("Freeing lookup table");
 189         if (table) {
 190                 if (table->array) {
 191                         for_lookup_table_entry(table,
 192                                                do_free_lookup_table_entry,
 193                                                NULL);
 194                         FREE(table->array);
 195                 }
 196                 FREE(table);
 197         }
 198 }
 199
 200 /*
 201  * Inserts an entry into the lookup table.
 202  *
 203  * @table:      A pointer to the lookup table.
 204  * @lte:        A pointer to the entry to insert.
 205  */
 206 void lookup_table_insert(struct wim_lookup_table *table,
 207                          struct wim_lookup_table_entry *lte)
 208 {
 209         size_t i = lte->hash_short % table->capacity;
 210         hlist_add_head(&lte->hash_list, &table->array[i]);
 211
 212         /* XXX Make the table grow when too many entries have been inserted. */
 213         table->num_entries++;
 214 }
 215
 216 static void finalize_lte(struct wim_lookup_table_entry *lte)
 217 {
 218         #ifdef WITH_FUSE
 219         if (lte->resource_location == RESOURCE_IN_STAGING_FILE) {
 220                 unlink(lte->staging_file_name);
 221                 list_del(&lte->staging_list);
 222         }
 223         #endif
 224         free_lookup_table_entry(lte);
 225 }
 226
 227 /* Decrements the reference count for the lookup table entry @lte.  If its
 228  * reference count reaches 0, it is unlinked from the lookup table.  If,
 229  * furthermore, the entry has no opened file descriptors associated with it, the
 230  * entry is freed.  */
 231 void lte_decrement_refcnt(struct wim_lookup_table_entry *lte,
 232                           struct wim_lookup_table *table)
 233 {
 234         wimlib_assert(lte != NULL);
 235         wimlib_assert(lte->refcnt != 0);
 236         if (--lte->refcnt == 0) {
 237                 lookup_table_unlink(table, lte);
 238         #ifdef WITH_FUSE
 239                 if (lte->num_opened_fds == 0)
 240         #endif
 241                         finalize_lte(lte);
 242         }
 243 }
 244
 245 #ifdef WITH_FUSE
 246 void lte_decrement_num_opened_fds(struct wim_lookup_table_entry *lte)
 247 {
 248         if (lte->num_opened_fds != 0)
 249                 if (--lte->num_opened_fds == 0 && lte->refcnt == 0)
 250                         finalize_lte(lte);
 251 }
 252 #endif
 253
 254 /* Calls a function on all the entries in the WIM lookup table.  Stop early and
 255  * return nonzero if any call to the function returns nonzero. */
 256 int for_lookup_table_entry(struct wim_lookup_table *table,
 257                            int (*visitor)(struct wim_lookup_table_entry *, void *),
 258                            void *arg)
 259 {
 260         struct wim_lookup_table_entry *lte;
 261         struct hlist_node *pos, *tmp;
 262         int ret;
 263
 264         for (size_t i = 0; i < table->capacity; i++) {
 265                 hlist_for_each_entry_safe(lte, pos, tmp, &table->array[i],
 266                                           hash_list)
 267                 {
 268                         ret = visitor(lte, arg);
 269                         if (ret != 0)
 270                                 return ret;
 271                 }
 272         }
 273         return 0;
 274 }
 275
 276
 277 /*
 278  * Reads the lookup table from a WIM file.
 279  */
 280 int 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 write_lookup_table_entry(struct wim_lookup_table_entry *lte, void *__out)
 415 {
 416         FILE *out;
 417         u8 buf[WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE];
 418         u8 *p;
 419
 420         out = __out;
 421
 422         /* Don't write entries that have not had file resources or metadata
 423          * resources written for them. */
 424         if (lte->out_refcnt == 0)
 425                 return 0;
 426
 427         if (lte->output_resource_entry.flags & WIM_RESHDR_FLAG_METADATA) {
 428                 DEBUG("Writing metadata entry at %"PRIu64" "
 429                       "(orig size = %"PRIu64")",
 430                       ftello(out), lte->output_resource_entry.original_size);
 431         }
 432
 433         p = put_resource_entry(buf, &lte->output_resource_entry);
 434         p = put_u16(p, lte->part_number);
 435         p = put_u32(p, lte->out_refcnt);
 436         p = put_bytes(p, SHA1_HASH_SIZE, lte->hash);
 437         if (fwrite(buf, 1, sizeof(buf), out) != sizeof(buf)) {
 438                 ERROR_WITH_ERRNO("Failed to write lookup table entry");
 439                 return WIMLIB_ERR_WRITE;
 440         }
 441         return 0;
 442 }
 443
 444 /* Writes the lookup table to the output file. */
 445 int write_lookup_table(struct wim_lookup_table *table, FILE *out,
 446                        struct resource_entry *out_res_entry)
 447 {
 448         off_t start_offset, end_offset;
 449         int ret;
 450
 451         start_offset = ftello(out);
 452         if (start_offset == -1)
 453                 return WIMLIB_ERR_WRITE;
 454
 455         ret = for_lookup_table_entry(table, write_lookup_table_entry, out);
 456         if (ret != 0)
 457                 return ret;
 458
 459         end_offset = ftello(out);
 460         if (end_offset == -1)
 461                 return WIMLIB_ERR_WRITE;
 462
 463         out_res_entry->offset        = start_offset;
 464         out_res_entry->size          = end_offset - start_offset;
 465         out_res_entry->original_size = end_offset - start_offset;
 466         out_res_entry->flags         = WIM_RESHDR_FLAG_METADATA;
 467
 468         return 0;
 469 }
 470
 471
 472 int lte_zero_real_refcnt(struct wim_lookup_table_entry *lte, void *ignore)
 473 {
 474         lte->real_refcnt = 0;
 475         return 0;
 476 }
 477
 478 int lte_zero_out_refcnt(struct wim_lookup_table_entry *lte, void *ignore)
 479 {
 480         lte->out_refcnt = 0;
 481         return 0;
 482 }
 483
 484 int lte_free_extracted_file(struct wim_lookup_table_entry *lte, void *ignore)
 485 {
 486         if (lte->extracted_file != NULL) {
 487                 FREE(lte->extracted_file);
 488                 lte->extracted_file = NULL;
 489         }
 490         return 0;
 491 }
 492
 493 void print_lookup_table_entry(const struct wim_lookup_table_entry *lte,
 494                               FILE *out)
 495 {
 496         if (!lte) {
 497                 putc('\n', out);
 498                 return;
 499         }
 500         fprintf(out, "Offset            = %"PRIu64" bytes\n",
 501                lte->resource_entry.offset);
 502         fprintf(out, "Size              = %"PRIu64" bytes\n",
 503                (u64)lte->resource_entry.size);
 504         fprintf(out, "Original size     = %"PRIu64" bytes\n",
 505                lte->resource_entry.original_size);
 506         fprintf(out, "Part Number       = %hu\n", lte->part_number);
 507         fprintf(out, "Reference Count   = %u\n", lte->refcnt);
 508         fprintf(out, "Hash              = 0x");
 509         print_hash(lte->hash);
 510         putc('\n', out);
 511         fprintf(out, "Flags             = ");
 512         u8 flags = lte->resource_entry.flags;
 513         if (flags & WIM_RESHDR_FLAG_COMPRESSED)
 514                 fputs("WIM_RESHDR_FLAG_COMPRESSED, ", out);
 515         if (flags & WIM_RESHDR_FLAG_FREE)
 516                 fputs("WIM_RESHDR_FLAG_FREE, ", out);
 517         if (flags & WIM_RESHDR_FLAG_METADATA)
 518                 fputs("WIM_RESHDR_FLAG_METADATA, ", out);
 519         if (flags & WIM_RESHDR_FLAG_SPANNED)
 520                 fputs("WIM_RESHDR_FLAG_SPANNED, ", out);
 521         putc('\n', out);
 522         switch (lte->resource_location) {
 523         case RESOURCE_IN_WIM:
 524                 if (lte->wim->filename) {
 525                         fprintf(out, "WIM file          = `%s'\n",
 526                                lte->wim->filename);
 527                 }
 528                 break;
 529         case RESOURCE_IN_FILE_ON_DISK:
 530                 fprintf(out, "File on Disk      = `%s'\n", lte->file_on_disk);
 531                 break;
 532         case RESOURCE_IN_STAGING_FILE:
 533                 fprintf(out, "Staging File      = `%s'\n", lte->staging_file_name);
 534                 break;
 535         default:
 536                 break;
 537         }
 538         putc('\n', out);
 539 }
 540
 541 static int do_print_lookup_table_entry(struct wim_lookup_table_entry *lte,
 542                                        void *fp)
 543 {
 544         print_lookup_table_entry(lte, (FILE*)fp);
 545         return 0;
 546 }
 547
 548 /*
 549  * Prints the lookup table of a WIM file.
 550  */
 551 WIMLIBAPI void wimlib_print_lookup_table(WIMStruct *w)
 552 {
 553         for_lookup_table_entry(w->lookup_table,
 554                                do_print_lookup_table_entry,
 555                                stdout);
 556 }
 557
 558 /* Given a SHA1 message digest, return the corresponding entry in the WIM's
 559  * lookup table, or NULL if there is none.  */
 560 struct wim_lookup_table_entry *
 561 __lookup_resource(const struct wim_lookup_table *table, const u8 hash[])
 562 {
 563         size_t i;
 564         struct wim_lookup_table_entry *lte;
 565         struct hlist_node *pos;
 566
 567         wimlib_assert(table != NULL);
 568         wimlib_assert(hash != NULL);
 569
 570         i = *(size_t*)hash % table->capacity;
 571         hlist_for_each_entry(lte, pos, &table->array[i], hash_list)
 572                 if (hashes_equal(hash, lte->hash))
 573                         return lte;
 574         return NULL;
 575 }
 576
 577 #ifdef WITH_FUSE
 578 /*
 579  * Finds the dentry, lookup table entry, and stream index for a WIM file stream,
 580  * given a path name.
 581  *
 582  * This is only for pre-resolved inodes.
 583  */
 584 int
 585 lookup_resource(WIMStruct *w,
 586                 const mbchar *path,
 587                 int lookup_flags,
 588                 struct wim_dentry **dentry_ret,
 589                 struct wim_lookup_table_entry **lte_ret,
 590                 u16 *stream_idx_ret)
 591 {
 592         struct wim_dentry *dentry;
 593         struct wim_lookup_table_entry *lte;
 594         u16 stream_idx;
 595         const mbchar *stream_name = NULL;
 596         struct wim_inode *inode;
 597         mbchar *p = NULL;
 598
 599         if (lookup_flags & LOOKUP_FLAG_ADS_OK) {
 600                 stream_name = path_stream_name(path);
 601                 if (stream_name) {
 602                         p = (mbchar*)stream_name - 1;
 603                         *p = '\0';
 604                 }
 605         }
 606
 607         dentry = get_dentry(w, path);
 608         if (p)
 609                 *p = ':';
 610         if (!dentry)
 611                 return -errno;
 612
 613         inode = dentry->d_inode;
 614
 615         wimlib_assert(inode->i_resolved);
 616
 617         if (!(lookup_flags & LOOKUP_FLAG_DIRECTORY_OK)
 618               && inode_is_directory(inode))
 619                 return -EISDIR;
 620
 621         if (stream_name) {
 622                 struct wim_ads_entry *ads_entry;
 623                 u16 ads_idx;
 624                 ads_entry = inode_get_ads_entry(inode, stream_name,
 625                                                 &ads_idx);
 626                 if (ads_entry) {
 627                         stream_idx = ads_idx + 1;
 628                         lte = ads_entry->lte;
 629                         goto out;
 630                 } else {
 631                         return -ENOENT;
 632                 }
 633         } else {
 634                 lte = inode->i_lte;
 635                 stream_idx = 0;
 636         }
 637 out:
 638         if (dentry_ret)
 639                 *dentry_ret = dentry;
 640         if (lte_ret)
 641                 *lte_ret = lte;
 642         if (stream_idx_ret)
 643                 *stream_idx_ret = stream_idx;
 644         return 0;
 645 }
 646 #endif
 647
 648 /* Resolve an inode's lookup table entries
 649  *
 650  * This replaces the SHA1 hash fields (which are used to lookup an entry in the
 651  * lookup table) with pointers directly to the lookup table entries.  A circular
 652  * linked list of streams sharing the same lookup table entry is created.
 653  *
 654  * This function always succeeds; unresolved lookup table entries are given a
 655  * NULL pointer.
 656  */
 657 void inode_resolve_ltes(struct wim_inode *inode, struct wim_lookup_table *table)
 658 {
 659
 660         if (!inode->i_resolved) {
 661                 struct wim_lookup_table_entry *lte;
 662                 /* Resolve the default file stream */
 663                 lte = __lookup_resource(table, inode->i_hash);
 664                 inode->i_lte = lte;
 665                 inode->i_resolved = 1;
 666
 667                 /* Resolve the alternate data streams */
 668                 for (u16 i = 0; i < inode->i_num_ads; i++) {
 669                         struct wim_ads_entry *cur_entry = &inode->i_ads_entries[i];
 670                         lte = __lookup_resource(table, cur_entry->hash);
 671                         cur_entry->lte = lte;
 672                 }
 673         }
 674 }
 675
 676 void inode_unresolve_ltes(struct wim_inode *inode)
 677 {
 678         if (inode->i_resolved) {
 679                 if (inode->i_lte)
 680                         copy_hash(inode->i_hash, inode->i_lte->hash);
 681                 else
 682                         zero_out_hash(inode->i_hash);
 683
 684                 for (u16 i = 0; i < inode->i_num_ads; i++) {
 685                         if (inode->i_ads_entries[i].lte)
 686                                 copy_hash(inode->i_ads_entries[i].hash,
 687                                           inode->i_ads_entries[i].lte->hash);
 688                         else
 689                                 zero_out_hash(inode->i_ads_entries[i].hash);
 690                 }
 691                 inode->i_resolved = 0;
 692         }
 693 }
 694
 695 /*
 696  * Returns the lookup table entry for stream @stream_idx of the inode, where
 697  * stream_idx = 0 means the default un-named file stream, and stream_idx >= 1
 698  * corresponds to an alternate data stream.
 699  *
 700  * This works for both resolved and un-resolved dentries.
 701  */
 702 struct wim_lookup_table_entry *
 703 inode_stream_lte(const struct wim_inode *inode, unsigned stream_idx,
 704                  const struct wim_lookup_table *table)
 705 {
 706         if (inode->i_resolved)
 707                 return inode_stream_lte_resolved(inode, stream_idx);
 708         else
 709                 return inode_stream_lte_unresolved(inode, stream_idx, table);
 710 }
 711
 712
 713 /* Return the lookup table entry for the unnamed data stream of an inode, or
 714  * NULL if there is none.
 715  *
 716  * You'd think this would be easier than it actually is, since the unnamed data
 717  * stream should be the one referenced from the inode itself.  Alas, if there
 718  * are named data streams, Microsoft's "imagex.exe" program will put the unnamed
 719  * data stream in one of the alternate data streams instead of inside the WIM
 720  * dentry itself.  So we need to check the alternate data streams too.
 721  *
 722  * Also, note that a dentry may appear to have more than one unnamed stream, but
 723  * if the SHA1 message digest is all 0's then the corresponding stream does not
 724  * really "count" (this is the case for the inode's own file stream when the
 725  * file stream that should be there is actually in one of the alternate stream
 726  * entries.).  This is despite the fact that we may need to extract such a
 727  * missing entry as an empty file or empty named data stream.
 728  */
 729 struct wim_lookup_table_entry *
 730 inode_unnamed_lte(const struct wim_inode *inode,
 731                   const struct wim_lookup_table *table)
 732 {
 733         if (inode->i_resolved)
 734                 return inode_unnamed_lte_resolved(inode);
 735         else
 736                 return inode_unnamed_lte_unresolved(inode, table);
 737 }
 738
 739 static int lte_add_stream_size(struct wim_lookup_table_entry *lte,
 740                                void *total_bytes_p)
 741 {
 742         *(u64*)total_bytes_p += lte->resource_entry.size;
 743         return 0;
 744 }
 745
 746 u64 lookup_table_total_stream_size(struct wim_lookup_table *table)
 747 {
 748         u64 total_size = 0;
 749         for_lookup_table_entry(table, lte_add_stream_size, &total_size);
 750         return total_size;
 751 }