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