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