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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; plus code to read and write the corresponding on-disk data.
   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 #ifdef HAVE_CONFIG_H
  28 #  include "config.h"
  29 #endif
  30
  31 #include "wimlib/endianness.h"
  32 #include "wimlib/error.h"
  33 #include "wimlib/file_io.h"
  34 #include "wimlib/lookup_table.h"
  35 #include "wimlib/metadata.h"
  36 #include "wimlib/paths.h"
  37 #include "wimlib/resource.h"
  38 #include "wimlib/util.h"
  39 #include "wimlib/write.h"
  40
  41 #include <errno.h>
  42 #include <stdlib.h>
  43 #ifdef WITH_FUSE
  44 #  include <unistd.h> /* for unlink() */
  45 #endif
  46
  47 struct wim_lookup_table *
  48 new_lookup_table(size_t capacity)
  49 {
  50         struct wim_lookup_table *table;
  51         struct hlist_head *array;
  52
  53         table = CALLOC(1, sizeof(struct wim_lookup_table));
  54         if (table) {
  55                 array = CALLOC(capacity, sizeof(array[0]));
  56                 if (array) {
  57                         table->num_entries = 0;
  58                         table->capacity = capacity;
  59                         table->array = array;
  60                 } else {
  61                         FREE(table);
  62                         table = NULL;
  63                         ERROR("Failed to allocate memory for lookup table "
  64                               "with capacity %zu", capacity);
  65                 }
  66         }
  67         return table;
  68 }
  69
  70 struct wim_lookup_table_entry *
  71 new_lookup_table_entry(void)
  72 {
  73         struct wim_lookup_table_entry *lte;
  74
  75         lte = CALLOC(1, sizeof(struct wim_lookup_table_entry));
  76         if (lte) {
  77                 lte->part_number  = 1;
  78                 lte->refcnt       = 1;
  79         } else {
  80                 ERROR("Out of memory (tried to allocate %zu bytes for "
  81                       "lookup table entry)",
  82                       sizeof(struct wim_lookup_table_entry));
  83         }
  84         return lte;
  85 }
  86
  87 struct wim_lookup_table_entry *
  88 clone_lookup_table_entry(const struct wim_lookup_table_entry *old)
  89 {
  90         struct wim_lookup_table_entry *new;
  91
  92         new = memdup(old, sizeof(struct wim_lookup_table_entry));
  93         if (!new)
  94                 return NULL;
  95
  96         new->extracted_file = NULL;
  97         switch (new->resource_location) {
  98         case RESOURCE_IN_FILE_ON_DISK:
  99 #ifdef __WIN32__
 100         case RESOURCE_WIN32_ENCRYPTED:
 101 #endif
 102 #ifdef WITH_FUSE
 103         case RESOURCE_IN_STAGING_FILE:
 104                 BUILD_BUG_ON((void*)&old->file_on_disk !=
 105                              (void*)&old->staging_file_name);
 106 #endif
 107                 new->file_on_disk = TSTRDUP(old->file_on_disk);
 108                 if (!new->file_on_disk)
 109                         goto out_free;
 110                 break;
 111         case RESOURCE_IN_ATTACHED_BUFFER:
 112                 new->attached_buffer = memdup(old->attached_buffer,
 113                                               wim_resource_size(old));
 114                 if (!new->attached_buffer)
 115                         goto out_free;
 116                 break;
 117 #ifdef WITH_NTFS_3G
 118         case RESOURCE_IN_NTFS_VOLUME:
 119                 if (old->ntfs_loc) {
 120                         struct ntfs_location *loc;
 121                         loc = memdup(old->ntfs_loc, sizeof(struct ntfs_location));
 122                         if (!loc)
 123                                 goto out_free;
 124                         loc->path = NULL;
 125                         loc->stream_name = NULL;
 126                         new->ntfs_loc = loc;
 127                         loc->path = STRDUP(old->ntfs_loc->path);
 128                         if (!loc->path)
 129                                 goto out_free;
 130                         if (loc->stream_name_nchars) {
 131                                 loc->stream_name = memdup(old->ntfs_loc->stream_name,
 132                                                           loc->stream_name_nchars * 2);
 133                                 if (!loc->stream_name)
 134                                         goto out_free;
 135                         }
 136                 }
 137                 break;
 138 #endif
 139         default:
 140                 break;
 141         }
 142         return new;
 143 out_free:
 144         free_lookup_table_entry(new);
 145         return NULL;
 146 }
 147
 148 void
 149 free_lookup_table_entry(struct wim_lookup_table_entry *lte)
 150 {
 151         if (lte) {
 152                 switch (lte->resource_location) {
 153                 case RESOURCE_IN_FILE_ON_DISK:
 154         #ifdef __WIN32__
 155                 case RESOURCE_WIN32_ENCRYPTED:
 156         #endif
 157         #ifdef WITH_FUSE
 158                 case RESOURCE_IN_STAGING_FILE:
 159                         BUILD_BUG_ON((void*)&lte->file_on_disk !=
 160                                      (void*)&lte->staging_file_name);
 161         #endif
 162                 case RESOURCE_IN_ATTACHED_BUFFER:
 163                         BUILD_BUG_ON((void*)&lte->file_on_disk !=
 164                                      (void*)&lte->attached_buffer);
 165                         FREE(lte->file_on_disk);
 166                         break;
 167 #ifdef WITH_NTFS_3G
 168                 case RESOURCE_IN_NTFS_VOLUME:
 169                         if (lte->ntfs_loc) {
 170                                 FREE(lte->ntfs_loc->path);
 171                                 FREE(lte->ntfs_loc->stream_name);
 172                                 FREE(lte->ntfs_loc);
 173                         }
 174                         break;
 175 #endif
 176                 default:
 177                         break;
 178                 }
 179                 FREE(lte);
 180         }
 181 }
 182
 183 static int
 184 do_free_lookup_table_entry(struct wim_lookup_table_entry *entry, void *ignore)
 185 {
 186         free_lookup_table_entry(entry);
 187         return 0;
 188 }
 189
 190
 191 void
 192 free_lookup_table(struct wim_lookup_table *table)
 193 {
 194         DEBUG2("Freeing lookup table");
 195         if (table) {
 196                 if (table->array) {
 197                         for_lookup_table_entry(table,
 198                                                do_free_lookup_table_entry,
 199                                                NULL);
 200                         FREE(table->array);
 201                 }
 202                 FREE(table);
 203         }
 204 }
 205
 206 /*
 207  * Inserts an entry into the lookup table.
 208  *
 209  * @table:      A pointer to the lookup table.
 210  * @lte:        A pointer to the entry to insert.
 211  */
 212 void
 213 lookup_table_insert(struct wim_lookup_table *table,
 214                     struct wim_lookup_table_entry *lte)
 215 {
 216         size_t i = lte->hash_short % table->capacity;
 217         hlist_add_head(&lte->hash_list, &table->array[i]);
 218
 219         /* XXX Make the table grow when too many entries have been inserted. */
 220         table->num_entries++;
 221 }
 222
 223 static void
 224 finalize_lte(struct wim_lookup_table_entry *lte)
 225 {
 226         #ifdef WITH_FUSE
 227         if (lte->resource_location == RESOURCE_IN_STAGING_FILE) {
 228                 unlink(lte->staging_file_name);
 229                 list_del(&lte->unhashed_list);
 230         }
 231         #endif
 232         free_lookup_table_entry(lte);
 233 }
 234
 235 /* Decrements the reference count for the lookup table entry @lte.  If its
 236  * reference count reaches 0, it is unlinked from the lookup table.  If,
 237  * furthermore, the entry has no opened file descriptors associated with it, the
 238  * entry is freed.  */
 239 void
 240 lte_decrement_refcnt(struct wim_lookup_table_entry *lte,
 241                      struct wim_lookup_table *table)
 242 {
 243         wimlib_assert(lte != NULL);
 244         wimlib_assert(lte->refcnt != 0);
 245         if (--lte->refcnt == 0) {
 246                 if (lte->unhashed)
 247                         list_del(&lte->unhashed_list);
 248                 else
 249                         lookup_table_unlink(table, lte);
 250         #ifdef WITH_FUSE
 251                 if (lte->num_opened_fds == 0)
 252         #endif
 253                         finalize_lte(lte);
 254         }
 255 }
 256
 257 #ifdef WITH_FUSE
 258 void
 259 lte_decrement_num_opened_fds(struct wim_lookup_table_entry *lte)
 260 {
 261         if (lte->num_opened_fds != 0)
 262                 if (--lte->num_opened_fds == 0 && lte->refcnt == 0)
 263                         finalize_lte(lte);
 264 }
 265 #endif
 266
 267 /* Calls a function on all the entries in the WIM lookup table.  Stop early and
 268  * return nonzero if any call to the function returns nonzero. */
 269 int
 270 for_lookup_table_entry(struct wim_lookup_table *table,
 271                        int (*visitor)(struct wim_lookup_table_entry *, void *),
 272                        void *arg)
 273 {
 274         struct wim_lookup_table_entry *lte;
 275         struct hlist_node *pos, *tmp;
 276         int ret;
 277
 278         for (size_t i = 0; i < table->capacity; i++) {
 279                 hlist_for_each_entry_safe(lte, pos, tmp, &table->array[i],
 280                                           hash_list)
 281                 {
 282                         wimlib_assert2(!(lte->resource_entry.flags & WIM_RESHDR_FLAG_METADATA));
 283                         ret = visitor(lte, arg);
 284                         if (ret)
 285                                 return ret;
 286                 }
 287         }
 288         return 0;
 289 }
 290
 291 /* qsort() callback that sorts streams (represented by `struct
 292  * wim_lookup_table_entry's) into an order optimized for reading and writing.
 293  *
 294  * Sorting is done primarily by resource location, then secondarily by a
 295  * per-resource location order.  For example, resources in WIM files are sorted
 296  * primarily by part number, then secondarily by offset, as to implement optimal
 297  * reading of either a standalone or split WIM.  */
 298 static int
 299 cmp_streams_by_sequential_order(const void *p1, const void *p2)
 300 {
 301         const struct wim_lookup_table_entry *lte1, *lte2;
 302         int v;
 303
 304         lte1 = *(const struct wim_lookup_table_entry**)p1;
 305         lte2 = *(const struct wim_lookup_table_entry**)p2;
 306
 307         v = (int)lte1->resource_location - (int)lte2->resource_location;
 308
 309         /* Different resource locations?  */
 310         if (v)
 311                 return v;
 312
 313         switch (lte1->resource_location) {
 314         case RESOURCE_IN_WIM:
 315
 316                 /* Different (possibly split) WIMs?  */
 317                 if (lte1->wim != lte2->wim) {
 318                         v = memcmp(lte1->wim->hdr.guid, lte2->wim->hdr.guid,
 319                                    WIM_GID_LEN);
 320                         if (v)
 321                                 return v;
 322                 }
 323
 324                 /* Different part numbers in the same WIM?  */
 325                 v = (int)lte1->wim->hdr.part_number - (int)lte2->wim->hdr.part_number;
 326                 if (v)
 327                         return v;
 328
 329                 /* Compare by offset.  */
 330                 if (lte1->resource_entry.offset < lte2->resource_entry.offset)
 331                         return -1;
 332                 else if (lte1->resource_entry.offset > lte2->resource_entry.offset)
 333                         return 1;
 334                 return 0;
 335         case RESOURCE_IN_FILE_ON_DISK:
 336 #ifdef __WIN32__
 337         case RESOURCE_WIN32_ENCRYPTED:
 338 #endif
 339                 /* Compare files by path: just a heuristic that will place files
 340                  * in the same directory next to each other.  */
 341                 return tstrcmp(lte1->file_on_disk, lte2->file_on_disk);
 342 #ifdef WITH_NTFS_3G
 343         case RESOURCE_IN_NTFS_VOLUME:
 344                 return tstrcmp(lte1->ntfs_loc->path, lte2->ntfs_loc->path);
 345 #endif
 346         default:
 347                 /* No additional sorting order defined for this resource
 348                  * location (e.g. RESOURCE_IN_ATTACHED_BUFFER); simply compare
 349                  * everything equal to each other.  */
 350                 return 0;
 351         }
 352 }
 353
 354 int
 355 sort_stream_list_by_sequential_order(struct list_head *stream_list,
 356                                      size_t list_head_offset)
 357 {
 358         struct list_head *cur;
 359         struct wim_lookup_table_entry **array;
 360         size_t i;
 361         size_t array_size;
 362         size_t num_streams = 0;
 363
 364         list_for_each(cur, stream_list)
 365                 num_streams++;
 366
 367         array_size = num_streams * sizeof(array[0]);
 368         array = MALLOC(array_size);
 369         if (!array)
 370                 return WIMLIB_ERR_NOMEM;
 371         cur = stream_list->next;
 372         for (i = 0; i < num_streams; i++) {
 373                 array[i] = (struct wim_lookup_table_entry*)((u8*)cur -
 374                                                             list_head_offset);
 375                 cur = cur->next;
 376         }
 377
 378         qsort(array, num_streams, sizeof(array[0]),
 379               cmp_streams_by_sequential_order);
 380
 381         INIT_LIST_HEAD(stream_list);
 382         for (i = 0; i < num_streams; i++) {
 383                 list_add_tail((struct list_head*)
 384                                ((u8*)array[i] + list_head_offset),
 385                               stream_list);
 386         }
 387         FREE(array);
 388         return 0;
 389 }
 390
 391
 392 static int
 393 add_lte_to_array(struct wim_lookup_table_entry *lte,
 394                  void *_pp)
 395 {
 396         struct wim_lookup_table_entry ***pp = _pp;
 397         *(*pp)++ = lte;
 398         return 0;
 399 }
 400
 401 /* Iterate through the lookup table entries, but first sort them by stream
 402  * offset in the WIM.  Caution: this is intended to be used when the stream
 403  * offset field has actually been set. */
 404 int
 405 for_lookup_table_entry_pos_sorted(struct wim_lookup_table *table,
 406                                   int (*visitor)(struct wim_lookup_table_entry *,
 407                                                  void *),
 408                                   void *arg)
 409 {
 410         struct wim_lookup_table_entry **lte_array, **p;
 411         size_t num_streams = table->num_entries;
 412         int ret;
 413
 414         lte_array = MALLOC(num_streams * sizeof(lte_array[0]));
 415         if (!lte_array)
 416                 return WIMLIB_ERR_NOMEM;
 417         p = lte_array;
 418         for_lookup_table_entry(table, add_lte_to_array, &p);
 419
 420         wimlib_assert(p == lte_array + num_streams);
 421
 422         qsort(lte_array, num_streams, sizeof(lte_array[0]),
 423               cmp_streams_by_sequential_order);
 424         ret = 0;
 425         for (size_t i = 0; i < num_streams; i++) {
 426                 ret = visitor(lte_array[i], arg);
 427                 if (ret)
 428                         break;
 429         }
 430         FREE(lte_array);
 431         return ret;
 432 }
 433
 434 /* On-disk format of a WIM lookup table entry (stream entry). */
 435 struct wim_lookup_table_entry_disk {
 436         /* Location, offset, compression status, and metadata status of the
 437          * stream. */
 438         struct resource_entry_disk resource_entry;
 439
 440         /* Which part of the split WIM this stream is in; indexed from 1. */
 441         le16 part_number;
 442
 443         /* Reference count of this stream over all WIM images. */
 444         le32 refcnt;
 445
 446         /* SHA1 message digest of the uncompressed data of this stream, or
 447          * optionally all zeroes if this stream is of zero length. */
 448         u8 hash[SHA1_HASH_SIZE];
 449 } _packed_attribute;
 450
 451 #define WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE 50
 452
 453 void
 454 lte_init_wim(struct wim_lookup_table_entry *lte, WIMStruct *wim)
 455 {
 456         lte->resource_location = RESOURCE_IN_WIM;
 457         lte->wim = wim;
 458         if (lte->resource_entry.flags & WIM_RESHDR_FLAG_COMPRESSED)
 459                 lte->compression_type = wim->compression_type;
 460         else
 461                 lte->compression_type = WIMLIB_COMPRESSION_TYPE_NONE;
 462
 463         if (wim_is_pipable(wim))
 464                 lte->is_pipable = 1;
 465 }
 466
 467 /*
 468  * Reads the lookup table from a WIM file.
 469  *
 470  * Saves lookup table entries for non-metadata streams in a hash table, and
 471  * saves the metadata entry for each image in a special per-image location (the
 472  * image_metadata array).
 473  *
 474  * Return values:
 475  *      WIMLIB_ERR_SUCCESS (0)
 476  *      WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY
 477  *      WIMLIB_ERR_RESOURCE_NOT_FOUND
 478  */
 479 int
 480 read_wim_lookup_table(WIMStruct *wim)
 481 {
 482         int ret;
 483         size_t i;
 484         size_t num_entries;
 485         struct wim_lookup_table *table;
 486         struct wim_lookup_table_entry *cur_entry, *duplicate_entry;
 487         struct wim_lookup_table_entry_disk *buf;
 488
 489         BUILD_BUG_ON(sizeof(struct wim_lookup_table_entry_disk) !=
 490                      WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE);
 491
 492         DEBUG("Reading lookup table: offset %"PRIu64", size %"PRIu64"",
 493               wim->hdr.lookup_table_res_entry.offset,
 494               wim->hdr.lookup_table_res_entry.size);
 495
 496         /* Calculate number of entries in the lookup table.  */
 497         num_entries = wim->hdr.lookup_table_res_entry.size /
 498                       sizeof(struct wim_lookup_table_entry_disk);
 499
 500
 501         /* Read the lookup table into a buffer.  */
 502         ret = res_entry_to_data(&wim->hdr.lookup_table_res_entry, wim,
 503                                 (void**)&buf);
 504         if (ret)
 505                 goto out;
 506
 507         /* Allocate hash table.  */
 508         table = new_lookup_table(num_entries * 2 + 1);
 509         if (!table) {
 510                 ERROR("Not enough memory to read lookup table.");
 511                 ret = WIMLIB_ERR_NOMEM;
 512                 goto out_free_buf;
 513         }
 514
 515         /* Allocate and initalize `struct wim_lookup_table_entry's from the
 516          * on-disk lookup table.  */
 517         wim->current_image = 0;
 518         for (i = 0; i < num_entries; i++) {
 519                 const struct wim_lookup_table_entry_disk *disk_entry = &buf[i];
 520
 521                 cur_entry = new_lookup_table_entry();
 522                 if (!cur_entry) {
 523                         ERROR("Not enough memory to read lookup table.");
 524                         ret = WIMLIB_ERR_NOMEM;
 525                         goto out_free_lookup_table;
 526                 }
 527
 528                 cur_entry->wim = wim;
 529                 cur_entry->resource_location = RESOURCE_IN_WIM;
 530                 get_resource_entry(&disk_entry->resource_entry, &cur_entry->resource_entry);
 531                 cur_entry->part_number = le16_to_cpu(disk_entry->part_number);
 532                 cur_entry->refcnt = le32_to_cpu(disk_entry->refcnt);
 533                 copy_hash(cur_entry->hash, disk_entry->hash);
 534                 lte_init_wim(cur_entry, wim);
 535
 536                 if (cur_entry->part_number != wim->hdr.part_number) {
 537                         WARNING("A lookup table entry in part %hu of the WIM "
 538                                 "points to part %hu (ignoring it)",
 539                                 wim->hdr.part_number, cur_entry->part_number);
 540                         free_lookup_table_entry(cur_entry);
 541                         continue;
 542                 }
 543
 544                 if (is_zero_hash(cur_entry->hash)) {
 545                         WARNING("The WIM lookup table contains an entry with a "
 546                                 "SHA1 message digest of all 0's (ignoring it)");
 547                         free_lookup_table_entry(cur_entry);
 548                         continue;
 549                 }
 550
 551                 if (!(cur_entry->resource_entry.flags & WIM_RESHDR_FLAG_COMPRESSED)
 552                     && (cur_entry->resource_entry.size !=
 553                         cur_entry->resource_entry.original_size))
 554                 {
 555                         if (wimlib_print_errors) {
 556                                 WARNING("Found uncompressed resource with "
 557                                         "original size (%"PRIu64") not the same "
 558                                         "as compressed size (%"PRIu64")",
 559                                         cur_entry->resource_entry.original_size,
 560                                         cur_entry->resource_entry.size);
 561                                 if (cur_entry->resource_entry.original_size) {
 562                                         WARNING("Overriding compressed size with original size.");
 563                                         cur_entry->resource_entry.size =
 564                                                 cur_entry->resource_entry.original_size;
 565                                 } else {
 566                                         WARNING("Overriding original size with compressed size");
 567                                         cur_entry->resource_entry.original_size =
 568                                                 cur_entry->resource_entry.size;
 569                                 }
 570                         }
 571                 }
 572
 573                 if (cur_entry->resource_entry.flags & WIM_RESHDR_FLAG_METADATA) {
 574                         /* Lookup table entry for a metadata resource */
 575                         if (cur_entry->refcnt != 1) {
 576                                 if (wimlib_print_errors) {
 577                                         ERROR("Found metadata resource with refcnt != 1:");
 578                                         print_lookup_table_entry(cur_entry, stderr);
 579                                 }
 580                                 ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
 581                                 goto out_free_cur_entry;
 582                         }
 583
 584                         if (wim->hdr.part_number != 1) {
 585                                 WARNING("Ignoring metadata resource found in a "
 586                                         "non-first part of the split WIM");
 587                                 free_lookup_table_entry(cur_entry);
 588                                 continue;
 589                         }
 590                         if (wim->current_image == wim->hdr.image_count) {
 591                                 WARNING("The WIM header says there are %u images "
 592                                         "in the WIM, but we found more metadata "
 593                                         "resources than this (ignoring the extra)",
 594                                         wim->hdr.image_count);
 595                                 free_lookup_table_entry(cur_entry);
 596                                 continue;
 597                         }
 598
 599                         /* Notice very carefully:  We are assigning the metadata
 600                          * resources in the exact order mirrored by their lookup
 601                          * table entries on disk, which is the behavior of
 602                          * Microsoft's software.  In particular, this overrides
 603                          * the actual locations of the metadata resources
 604                          * themselves in the WIM file as well as any information
 605                          * written in the XML data. */
 606                         DEBUG("Found metadata resource for image %u at "
 607                               "offset %"PRIu64".",
 608                               wim->current_image + 1,
 609                               cur_entry->resource_entry.offset);
 610                         wim->image_metadata[
 611                                 wim->current_image++]->metadata_lte = cur_entry;
 612                 } else {
 613                         /* Lookup table entry for a stream that is not a
 614                          * metadata resource */
 615                         duplicate_entry = __lookup_resource(table, cur_entry->hash);
 616                         if (duplicate_entry) {
 617                                 if (wimlib_print_errors) {
 618                                         WARNING("The WIM lookup table contains two entries with the "
 619                                               "same SHA1 message digest!");
 620                                         WARNING("The first entry is:");
 621                                         print_lookup_table_entry(duplicate_entry, stderr);
 622                                         WARNING("The second entry is:");
 623                                         print_lookup_table_entry(cur_entry, stderr);
 624                                 }
 625                                 free_lookup_table_entry(cur_entry);
 626                                 continue;
 627                         } else {
 628                                 lookup_table_insert(table, cur_entry);
 629                         }
 630                 }
 631         }
 632
 633         if (wim->hdr.part_number == 1 && wim->current_image != wim->hdr.image_count) {
 634                 WARNING("The header of \"%"TS"\" says there are %u images in\n"
 635                         "          the WIM, but we only found %d metadata resources!  Acting as if\n"
 636                         "          the header specified only %d images instead.",
 637                         wim->filename, wim->hdr.image_count,
 638                         wim->current_image, wim->current_image);
 639                 for (int i = wim->current_image; i < wim->hdr.image_count; i++)
 640                         put_image_metadata(wim->image_metadata[i], NULL);
 641                 wim->hdr.image_count = wim->current_image;
 642         }
 643         DEBUG("Done reading lookup table.");
 644         wim->lookup_table = table;
 645         ret = 0;
 646         goto out_free_buf;
 647 out_free_cur_entry:
 648         FREE(cur_entry);
 649 out_free_lookup_table:
 650         free_lookup_table(table);
 651 out_free_buf:
 652         FREE(buf);
 653 out:
 654         wim->current_image = 0;
 655         return ret;
 656 }
 657
 658
 659 static void
 660 write_wim_lookup_table_entry(const struct wim_lookup_table_entry *lte,
 661                              struct wim_lookup_table_entry_disk *disk_entry)
 662 {
 663         put_resource_entry(&lte->output_resource_entry, &disk_entry->resource_entry);
 664         disk_entry->part_number = cpu_to_le16(lte->part_number);
 665         disk_entry->refcnt = cpu_to_le32(lte->out_refcnt);
 666         copy_hash(disk_entry->hash, lte->hash);
 667 }
 668
 669 static int
 670 write_wim_lookup_table_from_stream_list(struct list_head *stream_list,
 671                                         struct filedes *out_fd,
 672                                         struct resource_entry *out_res_entry,
 673                                         int write_resource_flags)
 674 {
 675         size_t table_size;
 676         struct wim_lookup_table_entry *lte;
 677         struct wim_lookup_table_entry_disk *table_buf;
 678         struct wim_lookup_table_entry_disk *table_buf_ptr;
 679         int ret;
 680
 681         table_size = 0;
 682         list_for_each_entry(lte, stream_list, lookup_table_list)
 683                 table_size += sizeof(struct wim_lookup_table_entry_disk);
 684
 685         DEBUG("Writing WIM lookup table (size=%zu, offset=%"PRIu64")",
 686               table_size, out_fd->offset);
 687
 688         table_buf = MALLOC(table_size);
 689         if (!table_buf) {
 690                 ERROR("Failed to allocate %zu bytes for temporary lookup table",
 691                       table_size);
 692                 return WIMLIB_ERR_NOMEM;
 693         }
 694         table_buf_ptr = table_buf;
 695         list_for_each_entry(lte, stream_list, lookup_table_list)
 696                 write_wim_lookup_table_entry(lte, table_buf_ptr++);
 697
 698         /* Write the lookup table uncompressed.  Although wimlib can handle a
 699          * compressed lookup table, MS software cannot.  */
 700         ret = write_wim_resource_from_buffer(table_buf,
 701                                              table_size,
 702                                              WIM_RESHDR_FLAG_METADATA,
 703                                              out_fd,
 704                                              WIMLIB_COMPRESSION_TYPE_NONE,
 705                                              out_res_entry,
 706                                              NULL,
 707                                              write_resource_flags);
 708         FREE(table_buf);
 709         return ret;
 710 }
 711
 712 static int
 713 append_lookup_table_entry(struct wim_lookup_table_entry *lte, void *_list)
 714 {
 715         if (lte->out_refcnt != 0)
 716                 list_add_tail(&lte->lookup_table_list, (struct list_head*)_list);
 717         return 0;
 718 }
 719
 720 int
 721 write_wim_lookup_table(WIMStruct *wim, int image, int write_flags,
 722                        struct resource_entry *out_res_entry,
 723                        struct list_head *stream_list_override)
 724 {
 725         int write_resource_flags;
 726         struct list_head _stream_list;
 727         struct list_head *stream_list;
 728
 729         if (stream_list_override) {
 730                 stream_list = stream_list_override;
 731         } else {
 732                 stream_list = &_stream_list;
 733                 INIT_LIST_HEAD(stream_list);
 734         }
 735
 736         if (!(write_flags & WIMLIB_WRITE_FLAG_NO_METADATA)) {
 737                 int start_image;
 738                 int end_image;
 739
 740                 if (image == WIMLIB_ALL_IMAGES) {
 741                         start_image = 1;
 742                         end_image = wim->hdr.image_count;
 743                 } else {
 744                         start_image = image;
 745                         end_image = image;
 746                 }
 747
 748                 /* Push metadata resource lookup table entries onto the front of
 749                  * the list in reverse order, so that they're written in order.
 750                  */
 751                 for (int i = end_image; i >= start_image; i--) {
 752                         struct wim_lookup_table_entry *metadata_lte;
 753
 754                         metadata_lte = wim->image_metadata[i - 1]->metadata_lte;
 755                         metadata_lte->out_refcnt = 1;
 756                         metadata_lte->part_number = wim->hdr.part_number;
 757                         metadata_lte->output_resource_entry.flags |= WIM_RESHDR_FLAG_METADATA;
 758
 759                         list_add(&metadata_lte->lookup_table_list, stream_list);
 760                 }
 761         }
 762
 763         /* Append additional lookup table entries that have out_refcnt != 0.  */
 764         if (!stream_list_override) {
 765                 for_lookup_table_entry(wim->lookup_table,
 766                                        append_lookup_table_entry, stream_list);
 767         }
 768
 769         write_resource_flags = 0;
 770         if (write_flags & WIMLIB_WRITE_FLAG_PIPABLE)
 771                 write_resource_flags |= WIMLIB_WRITE_RESOURCE_FLAG_PIPABLE;
 772         return write_wim_lookup_table_from_stream_list(stream_list,
 773                                                        &wim->out_fd,
 774                                                        out_res_entry,
 775                                                        write_resource_flags);
 776 }
 777
 778
 779 int
 780 lte_zero_real_refcnt(struct wim_lookup_table_entry *lte, void *_ignore)
 781 {
 782         lte->real_refcnt = 0;
 783         return 0;
 784 }
 785
 786 int
 787 lte_zero_out_refcnt(struct wim_lookup_table_entry *lte, void *_ignore)
 788 {
 789         lte->out_refcnt = 0;
 790         return 0;
 791 }
 792
 793 int
 794 lte_free_extracted_file(struct wim_lookup_table_entry *lte, void *_ignore)
 795 {
 796         if (lte->extracted_file != NULL) {
 797                 FREE(lte->extracted_file);
 798                 lte->extracted_file = NULL;
 799         }
 800         return 0;
 801 }
 802
 803 void
 804 print_lookup_table_entry(const struct wim_lookup_table_entry *lte, FILE *out)
 805 {
 806         if (!lte) {
 807                 tputc(T('\n'), out);
 808                 return;
 809         }
 810         tfprintf(out, T("Offset            = %"PRIu64" bytes\n"),
 811                  lte->resource_entry.offset);
 812
 813         tfprintf(out, T("Size              = %"PRIu64" bytes\n"),
 814                  (u64)lte->resource_entry.size);
 815
 816         tfprintf(out, T("Original size     = %"PRIu64" bytes\n"),
 817                  lte->resource_entry.original_size);
 818
 819         tfprintf(out, T("Part Number       = %hu\n"), lte->part_number);
 820         tfprintf(out, T("Reference Count   = %u\n"), lte->refcnt);
 821
 822         if (lte->unhashed) {
 823                 tfprintf(out, T("(Unhashed: inode %p, stream_id = %u)\n"),
 824                          lte->back_inode, lte->back_stream_id);
 825         } else {
 826                 tfprintf(out, T("Hash              = 0x"));
 827                 print_hash(lte->hash, out);
 828                 tputc(T('\n'), out);
 829         }
 830
 831         tfprintf(out, T("Flags             = "));
 832         u8 flags = lte->resource_entry.flags;
 833         if (flags & WIM_RESHDR_FLAG_COMPRESSED)
 834                 tfputs(T("WIM_RESHDR_FLAG_COMPRESSED, "), out);
 835         if (flags & WIM_RESHDR_FLAG_FREE)
 836                 tfputs(T("WIM_RESHDR_FLAG_FREE, "), out);
 837         if (flags & WIM_RESHDR_FLAG_METADATA)
 838                 tfputs(T("WIM_RESHDR_FLAG_METADATA, "), out);
 839         if (flags & WIM_RESHDR_FLAG_SPANNED)
 840                 tfputs(T("WIM_RESHDR_FLAG_SPANNED, "), out);
 841         tputc(T('\n'), out);
 842         switch (lte->resource_location) {
 843         case RESOURCE_IN_WIM:
 844                 if (lte->wim->filename) {
 845                         tfprintf(out, T("WIM file          = `%"TS"'\n"),
 846                                  lte->wim->filename);
 847                 }
 848                 break;
 849 #ifdef __WIN32__
 850         case RESOURCE_WIN32_ENCRYPTED:
 851 #endif
 852         case RESOURCE_IN_FILE_ON_DISK:
 853                 tfprintf(out, T("File on Disk      = `%"TS"'\n"),
 854                          lte->file_on_disk);
 855                 break;
 856 #ifdef WITH_FUSE
 857         case RESOURCE_IN_STAGING_FILE:
 858                 tfprintf(out, T("Staging File      = `%"TS"'\n"),
 859                                 lte->staging_file_name);
 860                 break;
 861 #endif
 862         default:
 863                 break;
 864         }
 865         tputc(T('\n'), out);
 866 }
 867
 868 void
 869 lte_to_wimlib_resource_entry(const struct wim_lookup_table_entry *lte,
 870                              struct wimlib_resource_entry *wentry)
 871 {
 872         wentry->uncompressed_size = lte->resource_entry.original_size;
 873         wentry->compressed_size = lte->resource_entry.size;
 874         wentry->offset = lte->resource_entry.offset;
 875         copy_hash(wentry->sha1_hash, lte->hash);
 876         wentry->part_number = lte->part_number;
 877         wentry->reference_count = lte->refcnt;
 878         wentry->is_compressed = (lte->resource_entry.flags & WIM_RESHDR_FLAG_COMPRESSED) != 0;
 879         wentry->is_metadata = (lte->resource_entry.flags & WIM_RESHDR_FLAG_METADATA) != 0;
 880         wentry->is_free = (lte->resource_entry.flags & WIM_RESHDR_FLAG_FREE) != 0;
 881         wentry->is_spanned = (lte->resource_entry.flags & WIM_RESHDR_FLAG_SPANNED) != 0;
 882 }
 883
 884 struct iterate_lte_context {
 885         wimlib_iterate_lookup_table_callback_t cb;
 886         void *user_ctx;
 887 };
 888
 889 static int
 890 do_iterate_lte(struct wim_lookup_table_entry *lte, void *_ctx)
 891 {
 892         struct iterate_lte_context *ctx = _ctx;
 893         struct wimlib_resource_entry entry;
 894
 895         lte_to_wimlib_resource_entry(lte, &entry);
 896         return (*ctx->cb)(&entry, ctx->user_ctx);
 897 }
 898
 899 /* API function documented in wimlib.h  */
 900 WIMLIBAPI int
 901 wimlib_iterate_lookup_table(WIMStruct *wim, int flags,
 902                             wimlib_iterate_lookup_table_callback_t cb,
 903                             void *user_ctx)
 904 {
 905         struct iterate_lte_context ctx = {
 906                 .cb = cb,
 907                 .user_ctx = user_ctx,
 908         };
 909         if (wim->hdr.part_number == 1) {
 910                 int ret;
 911                 for (int i = 0; i < wim->hdr.image_count; i++) {
 912                         ret = do_iterate_lte(wim->image_metadata[i]->metadata_lte,
 913                                              &ctx);
 914                         if (ret)
 915                                 return ret;
 916                 }
 917         }
 918         return for_lookup_table_entry(wim->lookup_table, do_iterate_lte, &ctx);
 919 }
 920
 921 static int
 922 do_print_lookup_table_entry(struct wim_lookup_table_entry *lte, void *fp)
 923 {
 924         print_lookup_table_entry(lte, (FILE*)fp);
 925         return 0;
 926 }
 927
 928 /* API function documented in wimlib.h  */
 929 WIMLIBAPI void
 930 wimlib_print_lookup_table(WIMStruct *wim)
 931 {
 932         for (int i = 0; i < wim->hdr.image_count; i++)
 933                 print_lookup_table_entry(wim->image_metadata[i]->metadata_lte, stdout);
 934         for_lookup_table_entry(wim->lookup_table,
 935                                do_print_lookup_table_entry,
 936                                stdout);
 937 }
 938
 939 /* Given a SHA1 message digest, return the corresponding entry in the WIM's
 940  * lookup table, or NULL if there is none.  */
 941 struct wim_lookup_table_entry *
 942 __lookup_resource(const struct wim_lookup_table *table, const u8 hash[])
 943 {
 944         size_t i;
 945         struct wim_lookup_table_entry *lte;
 946         struct hlist_node *pos;
 947
 948         wimlib_assert(table != NULL);
 949         wimlib_assert(hash != NULL);
 950
 951         i = *(size_t*)hash % table->capacity;
 952         hlist_for_each_entry(lte, pos, &table->array[i], hash_list)
 953                 if (hashes_equal(hash, lte->hash))
 954                         return lte;
 955         return NULL;
 956 }
 957
 958 #ifdef WITH_FUSE
 959 /*
 960  * Finds the dentry, lookup table entry, and stream index for a WIM file stream,
 961  * given a path name.
 962  *
 963  * This is only for pre-resolved inodes.
 964  */
 965 int
 966 lookup_resource(WIMStruct *wim,
 967                 const tchar *path,
 968                 int lookup_flags,
 969                 struct wim_dentry **dentry_ret,
 970                 struct wim_lookup_table_entry **lte_ret,
 971                 u16 *stream_idx_ret)
 972 {
 973         struct wim_dentry *dentry;
 974         struct wim_lookup_table_entry *lte;
 975         u16 stream_idx;
 976         const tchar *stream_name = NULL;
 977         struct wim_inode *inode;
 978         tchar *p = NULL;
 979
 980         if (lookup_flags & LOOKUP_FLAG_ADS_OK) {
 981                 stream_name = path_stream_name(path);
 982                 if (stream_name) {
 983                         p = (tchar*)stream_name - 1;
 984                         *p = T('\0');
 985                 }
 986         }
 987
 988         dentry = get_dentry(wim, path);
 989         if (p)
 990                 *p = T(':');
 991         if (!dentry)
 992                 return -errno;
 993
 994         inode = dentry->d_inode;
 995
 996         if (!inode->i_resolved)
 997                 if (inode_resolve_ltes(inode, wim->lookup_table, false))
 998                         return -EIO;
 999
1000         if (!(lookup_flags & LOOKUP_FLAG_DIRECTORY_OK)
1001               && inode_is_directory(inode))
1002                 return -EISDIR;
1003
1004         if (stream_name) {
1005                 struct wim_ads_entry *ads_entry;
1006                 u16 ads_idx;
1007                 ads_entry = inode_get_ads_entry(inode, stream_name,
1008                                                 &ads_idx);
1009                 if (ads_entry) {
1010                         stream_idx = ads_idx + 1;
1011                         lte = ads_entry->lte;
1012                         goto out;
1013                 } else {
1014                         return -ENOENT;
1015                 }
1016         } else {
1017                 lte = inode->i_lte;
1018                 stream_idx = 0;
1019         }
1020 out:
1021         if (dentry_ret)
1022                 *dentry_ret = dentry;
1023         if (lte_ret)
1024                 *lte_ret = lte;
1025         if (stream_idx_ret)
1026                 *stream_idx_ret = stream_idx;
1027         return 0;
1028 }
1029 #endif
1030
1031 /*
1032  * Resolve an inode's lookup table entries.
1033  *
1034  * This replaces the SHA1 hash fields (which are used to lookup an entry in the
1035  * lookup table) with pointers directly to the lookup table entries.
1036  *
1037  * If @force is %false:
1038  *      If any needed SHA1 message digests are not found in the lookup table,
1039  *      WIMLIB_ERR_RESOURCE_NOT_FOUND is returned and the inode is left
1040  *      unmodified.
1041  * If @force is %true:
1042  *      If any needed SHA1 message digests are not found in the lookup table,
1043  *      new entries are allocated and inserted into the lookup table.
1044  */
1045 int
1046 inode_resolve_ltes(struct wim_inode *inode, struct wim_lookup_table *table,
1047                    bool force)
1048 {
1049         const u8 *hash;
1050
1051         if (!inode->i_resolved) {
1052                 struct wim_lookup_table_entry *lte, *ads_lte;
1053
1054                 /* Resolve the default file stream */
1055                 lte = NULL;
1056                 hash = inode->i_hash;
1057                 if (!is_zero_hash(hash)) {
1058                         lte = __lookup_resource(table, hash);
1059                         if (!lte) {
1060                                 if (force) {
1061                                         lte = new_lookup_table_entry();
1062                                         if (!lte)
1063                                                 return WIMLIB_ERR_NOMEM;
1064                                         copy_hash(lte->hash, hash);
1065                                         lookup_table_insert(table, lte);
1066                                 } else {
1067                                         goto resource_not_found;
1068                                 }
1069                         }
1070                 }
1071
1072                 /* Resolve the alternate data streams */
1073                 struct wim_lookup_table_entry *ads_ltes[inode->i_num_ads];
1074                 for (u16 i = 0; i < inode->i_num_ads; i++) {
1075                         struct wim_ads_entry *cur_entry;
1076
1077                         ads_lte = NULL;
1078                         cur_entry = &inode->i_ads_entries[i];
1079                         hash = cur_entry->hash;
1080                         if (!is_zero_hash(hash)) {
1081                                 ads_lte = __lookup_resource(table, hash);
1082                                 if (!ads_lte) {
1083                                         if (force) {
1084                                                 ads_lte = new_lookup_table_entry();
1085                                                 if (!ads_lte)
1086                                                         return WIMLIB_ERR_NOMEM;
1087                                                 copy_hash(ads_lte->hash, hash);
1088                                                 lookup_table_insert(table, ads_lte);
1089                                         } else {
1090                                                 goto resource_not_found;
1091                                         }
1092                                 }
1093                         }
1094                         ads_ltes[i] = ads_lte;
1095                 }
1096                 inode->i_lte = lte;
1097                 for (u16 i = 0; i < inode->i_num_ads; i++)
1098                         inode->i_ads_entries[i].lte = ads_ltes[i];
1099                 inode->i_resolved = 1;
1100         }
1101         return 0;
1102 resource_not_found:
1103         if (wimlib_print_errors) {
1104                 ERROR("\"%"TS"\": resource not found", inode_first_full_path(inode));
1105                 tfprintf(stderr, T("        SHA-1 message digest of missing resource:\n        "));
1106                 print_hash(hash, stderr);
1107                 tputc(T('\n'), stderr);
1108         }
1109         return WIMLIB_ERR_RESOURCE_NOT_FOUND;
1110 }
1111
1112 void
1113 inode_unresolve_ltes(struct wim_inode *inode)
1114 {
1115         if (inode->i_resolved) {
1116                 if (inode->i_lte)
1117                         copy_hash(inode->i_hash, inode->i_lte->hash);
1118                 else
1119                         zero_out_hash(inode->i_hash);
1120
1121                 for (u16 i = 0; i < inode->i_num_ads; i++) {
1122                         if (inode->i_ads_entries[i].lte)
1123                                 copy_hash(inode->i_ads_entries[i].hash,
1124                                           inode->i_ads_entries[i].lte->hash);
1125                         else
1126                                 zero_out_hash(inode->i_ads_entries[i].hash);
1127                 }
1128                 inode->i_resolved = 0;
1129         }
1130 }
1131
1132 /*
1133  * Returns the lookup table entry for stream @stream_idx of the inode, where
1134  * stream_idx = 0 means the default un-named file stream, and stream_idx >= 1
1135  * corresponds to an alternate data stream.
1136  *
1137  * This works for both resolved and un-resolved inodes.
1138  */
1139 struct wim_lookup_table_entry *
1140 inode_stream_lte(const struct wim_inode *inode, unsigned stream_idx,
1141                  const struct wim_lookup_table *table)
1142 {
1143         if (inode->i_resolved)
1144                 return inode_stream_lte_resolved(inode, stream_idx);
1145         else
1146                 return inode_stream_lte_unresolved(inode, stream_idx, table);
1147 }
1148
1149 struct wim_lookup_table_entry *
1150 inode_unnamed_lte_resolved(const struct wim_inode *inode)
1151 {
1152         wimlib_assert(inode->i_resolved);
1153         for (unsigned i = 0; i <= inode->i_num_ads; i++) {
1154                 if (inode_stream_name_nbytes(inode, i) == 0 &&
1155                     !is_zero_hash(inode_stream_hash_resolved(inode, i)))
1156                 {
1157                         return inode_stream_lte_resolved(inode, i);
1158                 }
1159         }
1160         return NULL;
1161 }
1162
1163 struct wim_lookup_table_entry *
1164 inode_unnamed_lte_unresolved(const struct wim_inode *inode,
1165                              const struct wim_lookup_table *table)
1166 {
1167         wimlib_assert(!inode->i_resolved);
1168         for (unsigned i = 0; i <= inode->i_num_ads; i++) {
1169                 if (inode_stream_name_nbytes(inode, i) == 0 &&
1170                     !is_zero_hash(inode_stream_hash_unresolved(inode, i)))
1171                 {
1172                         return inode_stream_lte_unresolved(inode, i, table);
1173                 }
1174         }
1175         return NULL;
1176 }
1177
1178 /* Return the lookup table entry for the unnamed data stream of an inode, or
1179  * NULL if there is none.
1180  *
1181  * You'd think this would be easier than it actually is, since the unnamed data
1182  * stream should be the one referenced from the inode itself.  Alas, if there
1183  * are named data streams, Microsoft's "imagex.exe" program will put the unnamed
1184  * data stream in one of the alternate data streams instead of inside the WIM
1185  * dentry itself.  So we need to check the alternate data streams too.
1186  *
1187  * Also, note that a dentry may appear to have more than one unnamed stream, but
1188  * if the SHA1 message digest is all 0's then the corresponding stream does not
1189  * really "count" (this is the case for the inode's own file stream when the
1190  * file stream that should be there is actually in one of the alternate stream
1191  * entries.).  This is despite the fact that we may need to extract such a
1192  * missing entry as an empty file or empty named data stream.
1193  */
1194 struct wim_lookup_table_entry *
1195 inode_unnamed_lte(const struct wim_inode *inode,
1196                   const struct wim_lookup_table *table)
1197 {
1198         if (inode->i_resolved)
1199                 return inode_unnamed_lte_resolved(inode);
1200         else
1201                 return inode_unnamed_lte_unresolved(inode, table);
1202 }
1203
1204 static int
1205 lte_add_stream_size(struct wim_lookup_table_entry *lte, void *total_bytes_p)
1206 {
1207         *(u64*)total_bytes_p += lte->resource_entry.size;
1208         return 0;
1209 }
1210
1211 u64
1212 lookup_table_total_stream_size(struct wim_lookup_table *table)
1213 {
1214         u64 total_size = 0;
1215         for_lookup_table_entry(table, lte_add_stream_size, &total_size);
1216         return total_size;
1217 }
1218
1219 struct wim_lookup_table_entry **
1220 retrieve_lte_pointer(struct wim_lookup_table_entry *lte)
1221 {
1222         wimlib_assert(lte->unhashed);
1223         struct wim_inode *inode = lte->back_inode;
1224         u32 stream_id = lte->back_stream_id;
1225         if (stream_id == 0)
1226                 return &inode->i_lte;
1227         else
1228                 for (u16 i = 0; i < inode->i_num_ads; i++)
1229                         if (inode->i_ads_entries[i].stream_id == stream_id)
1230                                 return &inode->i_ads_entries[i].lte;
1231         wimlib_assert(0);
1232         return NULL;
1233 }
1234
1235 /* Calculate the SHA1 message digest of a stream and move it from the list of
1236  * unhashed streams to the stream lookup table, possibly joining it with an
1237  * existing lookup table entry for an identical stream.
1238  *
1239  * @lte:  An unhashed lookup table entry.
1240  * @lookup_table:  Lookup table for the WIM.
1241  * @lte_ret:  On success, write a pointer to the resulting lookup table
1242  *            entry to this location.  This will be the same as @lte
1243  *            if it was inserted into the lookup table, or different if
1244  *            a duplicate stream was found.
1245  *
1246  * Returns 0 on success; nonzero if there is an error reading the stream.
1247  */
1248 int
1249 hash_unhashed_stream(struct wim_lookup_table_entry *lte,
1250                      struct wim_lookup_table *lookup_table,
1251                      struct wim_lookup_table_entry **lte_ret)
1252 {
1253         int ret;
1254         struct wim_lookup_table_entry *duplicate_lte;
1255         struct wim_lookup_table_entry **back_ptr;
1256
1257         wimlib_assert(lte->unhashed);
1258
1259         /* back_ptr must be saved because @back_inode and @back_stream_id are in
1260          * union with the SHA1 message digest and will no longer be valid once
1261          * the SHA1 has been calculated. */
1262         back_ptr = retrieve_lte_pointer(lte);
1263
1264         ret = sha1_resource(lte);
1265         if (ret)
1266                 return ret;
1267
1268         /* Look for a duplicate stream */
1269         duplicate_lte = __lookup_resource(lookup_table, lte->hash);
1270         list_del(&lte->unhashed_list);
1271         if (duplicate_lte) {
1272                 /* We have a duplicate stream.  Transfer the reference counts
1273                  * from this stream to the duplicate, update the reference to
1274                  * this stream (in an inode or ads_entry) to point to the
1275                  * duplicate, then free this stream. */
1276                 wimlib_assert(!(duplicate_lte->unhashed));
1277                 duplicate_lte->refcnt += lte->refcnt;
1278                 duplicate_lte->out_refcnt += lte->refcnt;
1279                 *back_ptr = duplicate_lte;
1280                 free_lookup_table_entry(lte);
1281                 lte = duplicate_lte;
1282         } else {
1283                 /* No duplicate stream, so we need to insert
1284                  * this stream into the lookup table and treat
1285                  * it as a hashed stream. */
1286                 lookup_table_insert(lookup_table, lte);
1287                 lte->unhashed = 0;
1288         }
1289         if (lte_ret)
1290                 *lte_ret = lte;
1291         return 0;
1292 }