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