4 * A dentry (directory entry) contains the metadata for a file. In the WIM file
5 * format, the dentries are stored in the "metadata resource" section right
6 * after the security data. Each image in the WIM file has its own metadata
7 * resource with its own security data and dentry tree. Dentries in different
8 * images may share file resources by referring to the same lookup table
13 * Copyright (C) 2012 Eric Biggers
15 * This file is part of wimlib, a library for working with WIM files.
17 * wimlib is free software; you can redistribute it and/or modify it under the
18 * terms of the GNU General Public License as published by the Free Software
19 * Foundation; either version 3 of the License, or (at your option) any later
22 * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
23 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
24 * A PARTICULAR PURPOSE. See the GNU General Public License for more details.
26 * You should have received a copy of the GNU General Public License along with
27 * wimlib; if not, see http://www.gnu.org/licenses/.
37 #include "lookup_table.h"
39 #include "timestamp.h"
40 #include "wimlib_internal.h"
43 * Returns true if @dentry has the UTF-8 file name @name that has length
46 static bool dentry_has_name(const struct dentry *dentry, const char *name,
49 if (dentry->file_name_utf8_len != name_len)
51 return memcmp(dentry->file_name_utf8, name, name_len) == 0;
54 static u64 __dentry_correct_length_unaligned(u16 file_name_len,
57 u64 length = WIM_DENTRY_DISK_SIZE;
59 length += file_name_len + 2;
61 length += short_name_len + 2;
65 static u64 dentry_correct_length_unaligned(const struct dentry *dentry)
67 return __dentry_correct_length_unaligned(dentry->file_name_len,
68 dentry->short_name_len);
71 /* Return the "correct" value to write in the length field of the dentry, based
72 * on the file name length and short name length */
73 static u64 dentry_correct_length(const struct dentry *dentry)
75 return (dentry_correct_length_unaligned(dentry) + 7) & ~7;
78 static u64 __dentry_total_length(const struct dentry *dentry, u64 length)
80 const struct inode *inode = dentry->inode;
81 for (u16 i = 0; i < inode->num_ads; i++)
82 length += ads_entry_total_length(inode->ads_entries[i]);
83 return (length + 7) & ~7;
86 u64 dentry_correct_total_length(const struct dentry *dentry)
88 return __dentry_total_length(dentry,
89 dentry_correct_length_unaligned(dentry));
92 /* Real length of a dentry, including the alternate data stream entries, which
93 * are not included in the dentry->length field... */
94 u64 dentry_total_length(const struct dentry *dentry)
96 return __dentry_total_length(dentry, dentry->length);
99 /* Transfers file attributes from a `stat' buffer to an inode. */
100 void stbuf_to_inode(const struct stat *stbuf, struct inode *inode)
102 if (S_ISLNK(stbuf->st_mode)) {
103 inode->attributes = FILE_ATTRIBUTE_REPARSE_POINT;
104 inode->reparse_tag = WIM_IO_REPARSE_TAG_SYMLINK;
105 } else if (S_ISDIR(stbuf->st_mode)) {
106 inode->attributes = FILE_ATTRIBUTE_DIRECTORY;
108 inode->attributes = FILE_ATTRIBUTE_NORMAL;
110 if (sizeof(ino_t) >= 8)
111 inode->ino = (u64)stbuf->st_ino;
113 inode->ino = (u64)stbuf->st_ino |
114 ((u64)stbuf->st_dev << (sizeof(ino_t) * 8));
116 inode->creation_time = timespec_to_wim_timestamp(&stbuf->st_mtim);
117 inode->last_write_time = timespec_to_wim_timestamp(&stbuf->st_mtim);
118 inode->last_access_time = timespec_to_wim_timestamp(&stbuf->st_atim);
122 /* Sets all the timestamp fields of the dentry to the current time. */
123 void inode_update_all_timestamps(struct inode *inode)
125 u64 now = get_wim_timestamp();
126 inode->creation_time = now;
127 inode->last_access_time = now;
128 inode->last_write_time = now;
131 /* Returns the alternate data stream entry belonging to @inode that has the
132 * stream name @stream_name. */
133 struct ads_entry *inode_get_ads_entry(struct inode *inode,
134 const char *stream_name,
137 size_t stream_name_len;
140 if (inode->num_ads) {
142 stream_name_len = strlen(stream_name);
144 if (ads_entry_has_name(inode->ads_entries[i],
145 stream_name, stream_name_len))
149 return inode->ads_entries[i];
151 } while (++i != inode->num_ads);
157 static struct ads_entry *new_ads_entry(const char *name)
159 struct ads_entry *ads_entry = CALLOC(1, sizeof(struct ads_entry));
163 if (change_ads_name(ads_entry, name)) {
172 * Add an alternate stream entry to an inode and return a pointer to it, or NULL
173 * if memory could not be allocated.
175 struct ads_entry *inode_add_ads(struct inode *inode, const char *stream_name)
178 struct ads_entry **ads_entries;
179 struct ads_entry *new_entry;
181 if (inode->num_ads >= 0xfffe) {
182 ERROR("Too many alternate data streams in one inode!");
185 num_ads = inode->num_ads + 1;
186 ads_entries = REALLOC(inode->ads_entries,
187 num_ads * sizeof(inode->ads_entries[0]));
189 ERROR("Failed to allocate memory for new alternate data stream");
192 inode->ads_entries = ads_entries;
194 new_entry = new_ads_entry(stream_name);
197 inode->num_ads = num_ads;
198 ads_entries[num_ads - 1] = new_entry;
200 new_entry->stream_id = inode->next_stream_id++;
207 * Calls a function on all directory entries in a directory tree. It is called
208 * on a parent before its children.
210 int for_dentry_in_tree(struct dentry *root,
211 int (*visitor)(struct dentry*, void*), void *arg)
214 struct dentry *child;
216 ret = visitor(root, arg);
221 child = root->inode->children;
227 ret = for_dentry_in_tree(child, visitor, arg);
231 } while (child != root->inode->children);
236 * Like for_dentry_in_tree(), but the visitor function is always called on a
237 * dentry's children before on itself.
239 int for_dentry_in_tree_depth(struct dentry *root,
240 int (*visitor)(struct dentry*, void*), void *arg)
243 struct dentry *child;
246 child = root->inode->children;
250 ret = for_dentry_in_tree_depth(child, visitor, arg);
254 } while (child != root->inode->children);
256 return visitor(root, arg);
260 * Calculate the full path of @dentry, based on its parent's full path and on
261 * its UTF-8 file name.
263 int calculate_dentry_full_path(struct dentry *dentry, void *ignore)
267 if (dentry_is_root(dentry)) {
268 full_path = MALLOC(2);
275 char *parent_full_path;
276 u32 parent_full_path_len;
277 const struct dentry *parent = dentry->parent;
279 if (dentry_is_root(parent)) {
280 parent_full_path = "";
281 parent_full_path_len = 0;
283 parent_full_path = parent->full_path_utf8;
284 parent_full_path_len = parent->full_path_utf8_len;
287 full_path_len = parent_full_path_len + 1 +
288 dentry->file_name_utf8_len;
289 full_path = MALLOC(full_path_len + 1);
293 memcpy(full_path, parent_full_path, parent_full_path_len);
294 full_path[parent_full_path_len] = '/';
295 memcpy(full_path + parent_full_path_len + 1,
296 dentry->file_name_utf8,
297 dentry->file_name_utf8_len);
298 full_path[full_path_len] = '\0';
300 FREE(dentry->full_path_utf8);
301 dentry->full_path_utf8 = full_path;
302 dentry->full_path_utf8_len = full_path_len;
305 ERROR("Out of memory while calculating dentry full path");
306 return WIMLIB_ERR_NOMEM;
310 * Recursively calculates the subdir offsets for a directory tree.
312 * @dentry: The root of the directory tree.
313 * @subdir_offset_p: The current subdirectory offset; i.e., the subdirectory
314 * offset for @dentry.
316 void calculate_subdir_offsets(struct dentry *dentry, u64 *subdir_offset_p)
318 struct dentry *child;
320 child = dentry->inode->children;
321 dentry->subdir_offset = *subdir_offset_p;
324 /* Advance the subdir offset by the amount of space the children
325 * of this dentry take up. */
327 *subdir_offset_p += dentry_correct_total_length(child);
329 } while (child != dentry->inode->children);
331 /* End-of-directory dentry on disk. */
332 *subdir_offset_p += 8;
334 /* Recursively call calculate_subdir_offsets() on all the
337 calculate_subdir_offsets(child, subdir_offset_p);
339 } while (child != dentry->inode->children);
341 /* On disk, childless directories have a valid subdir_offset
342 * that points to an 8-byte end-of-directory dentry. Regular
343 * files or reparse points have a subdir_offset of 0. */
344 if (dentry_is_directory(dentry))
345 *subdir_offset_p += 8;
347 dentry->subdir_offset = 0;
352 /* Returns the child of @dentry that has the file name @name.
353 * Returns NULL if no child has the name. */
354 struct dentry *get_dentry_child_with_name(const struct dentry *dentry,
357 struct dentry *child;
360 child = dentry->inode->children;
362 name_len = strlen(name);
364 if (dentry_has_name(child, name, name_len))
367 } while (child != dentry->inode->children);
372 /* Retrieves the dentry that has the UTF-8 @path relative to the dentry
373 * @cur_dir. Returns NULL if no dentry having the path is found. */
374 static struct dentry *get_dentry_relative_path(struct dentry *cur_dir,
377 struct dentry *child;
379 const char *new_path;
384 child = cur_dir->inode->children;
386 new_path = path_next_part(path, &base_len);
388 if (dentry_has_name(child, path, base_len))
389 return get_dentry_relative_path(child, new_path);
391 } while (child != cur_dir->inode->children);
396 /* Returns the dentry corresponding to the UTF-8 @path, or NULL if there is no
398 struct dentry *get_dentry(WIMStruct *w, const char *path)
400 struct dentry *root = wim_root_dentry(w);
403 return get_dentry_relative_path(root, path);
406 struct inode *wim_pathname_to_inode(WIMStruct *w, const char *path)
408 struct dentry *dentry;
409 dentry = get_dentry(w, path);
413 return dentry->inode;
416 /* Returns the dentry that corresponds to the parent directory of @path, or NULL
417 * if the dentry is not found. */
418 struct dentry *get_parent_dentry(WIMStruct *w, const char *path)
420 size_t path_len = strlen(path);
421 char buf[path_len + 1];
423 memcpy(buf, path, path_len + 1);
425 to_parent_name(buf, path_len);
427 return get_dentry(w, buf);
430 /* Prints the full path of a dentry. */
431 int print_dentry_full_path(struct dentry *dentry, void *ignore)
433 if (dentry->full_path_utf8)
434 puts(dentry->full_path_utf8);
438 /* We want to be able to show the names of the file attribute flags that are
440 struct file_attr_flag {
444 struct file_attr_flag file_attr_flags[] = {
445 {FILE_ATTRIBUTE_READONLY, "READONLY"},
446 {FILE_ATTRIBUTE_HIDDEN, "HIDDEN"},
447 {FILE_ATTRIBUTE_SYSTEM, "SYSTEM"},
448 {FILE_ATTRIBUTE_DIRECTORY, "DIRECTORY"},
449 {FILE_ATTRIBUTE_ARCHIVE, "ARCHIVE"},
450 {FILE_ATTRIBUTE_DEVICE, "DEVICE"},
451 {FILE_ATTRIBUTE_NORMAL, "NORMAL"},
452 {FILE_ATTRIBUTE_TEMPORARY, "TEMPORARY"},
453 {FILE_ATTRIBUTE_SPARSE_FILE, "SPARSE_FILE"},
454 {FILE_ATTRIBUTE_REPARSE_POINT, "REPARSE_POINT"},
455 {FILE_ATTRIBUTE_COMPRESSED, "COMPRESSED"},
456 {FILE_ATTRIBUTE_OFFLINE, "OFFLINE"},
457 {FILE_ATTRIBUTE_NOT_CONTENT_INDEXED,"NOT_CONTENT_INDEXED"},
458 {FILE_ATTRIBUTE_ENCRYPTED, "ENCRYPTED"},
459 {FILE_ATTRIBUTE_VIRTUAL, "VIRTUAL"},
462 /* Prints a directory entry. @lookup_table is a pointer to the lookup table, if
463 * available. If the dentry is unresolved and the lookup table is NULL, the
464 * lookup table entries will not be printed. Otherwise, they will be. */
465 int print_dentry(struct dentry *dentry, void *lookup_table)
468 struct lookup_table_entry *lte;
469 const struct inode *inode = dentry->inode;
473 printf("[DENTRY]\n");
474 printf("Length = %"PRIu64"\n", dentry->length);
475 printf("Attributes = 0x%x\n", inode->attributes);
476 for (unsigned i = 0; i < ARRAY_LEN(file_attr_flags); i++)
477 if (file_attr_flags[i].flag & inode->attributes)
478 printf(" FILE_ATTRIBUTE_%s is set\n",
479 file_attr_flags[i].name);
480 printf("Security ID = %d\n", inode->security_id);
481 printf("Subdir offset = %"PRIu64"\n", dentry->subdir_offset);
483 /* Translate the timestamps into something readable */
484 time = wim_timestamp_to_unix(inode->creation_time);
485 p = asctime(gmtime(&time));
486 *(strrchr(p, '\n')) = '\0';
487 printf("Creation Time = %s UTC\n", p);
489 time = wim_timestamp_to_unix(inode->last_access_time);
490 p = asctime(gmtime(&time));
491 *(strrchr(p, '\n')) = '\0';
492 printf("Last Access Time = %s UTC\n", p);
494 time = wim_timestamp_to_unix(inode->last_write_time);
495 p = asctime(gmtime(&time));
496 *(strrchr(p, '\n')) = '\0';
497 printf("Last Write Time = %s UTC\n", p);
499 printf("Reparse Tag = 0x%"PRIx32"\n", inode->reparse_tag);
500 printf("Hard Link Group = 0x%"PRIx64"\n", inode->ino);
501 printf("Hard Link Group Size = %"PRIu32"\n", inode->link_count);
502 printf("Number of Alternate Data Streams = %hu\n", inode->num_ads);
503 printf("Filename = \"");
504 print_string(dentry->file_name, dentry->file_name_len);
506 printf("Filename Length = %hu\n", dentry->file_name_len);
507 printf("Filename (UTF-8) = \"%s\"\n", dentry->file_name_utf8);
508 printf("Filename (UTF-8) Length = %hu\n", dentry->file_name_utf8_len);
509 printf("Short Name = \"");
510 print_string(dentry->short_name, dentry->short_name_len);
512 printf("Short Name Length = %hu\n", dentry->short_name_len);
513 printf("Full Path (UTF-8) = \"%s\"\n", dentry->full_path_utf8);
514 lte = inode_stream_lte(dentry->inode, 0, lookup_table);
516 print_lookup_table_entry(lte);
518 hash = inode_stream_hash(inode, 0);
526 for (u16 i = 0; i < inode->num_ads; i++) {
527 printf("[Alternate Stream Entry %u]\n", i);
528 printf("Name = \"%s\"\n", inode->ads_entries[i]->stream_name_utf8);
529 printf("Name Length (UTF-16) = %u\n",
530 inode->ads_entries[i]->stream_name_len);
531 hash = inode_stream_hash(inode, i + 1);
537 print_lookup_table_entry(inode_stream_lte(inode, i + 1,
543 /* Initializations done on every `struct dentry'. */
544 static void dentry_common_init(struct dentry *dentry)
546 memset(dentry, 0, sizeof(struct dentry));
550 struct inode *new_timeless_inode()
552 struct inode *inode = CALLOC(1, sizeof(struct inode));
555 inode->security_id = -1;
556 inode->link_count = 1;
557 INIT_LIST_HEAD(&inode->dentry_list);
561 struct inode *new_inode()
563 struct inode *inode = new_timeless_inode();
566 u64 now = get_wim_timestamp();
567 inode->creation_time = now;
568 inode->last_access_time = now;
569 inode->last_write_time = now;
574 * Creates an unlinked directory entry.
576 * @name: The UTF-8 filename of the new dentry.
578 * Returns a pointer to the new dentry, or NULL if out of memory.
580 struct dentry *new_dentry(const char *name)
582 struct dentry *dentry;
584 dentry = MALLOC(sizeof(struct dentry));
588 dentry_common_init(dentry);
589 if (change_dentry_name(dentry, name) != 0)
592 dentry->next = dentry;
593 dentry->prev = dentry;
594 dentry->parent = dentry;
599 ERROR("Failed to allocate new dentry");
603 struct dentry *new_dentry_with_inode(const char *name)
605 struct dentry *dentry;
606 dentry = new_dentry(name);
608 dentry->inode = new_inode();
610 inode_add_dentry(dentry, dentry->inode);
619 void free_ads_entry(struct ads_entry *entry)
622 FREE(entry->stream_name);
623 FREE(entry->stream_name_utf8);
628 void inode_free_ads_entries(struct inode *inode)
630 if (inode->ads_entries) {
631 for (u16 i = 0; i < inode->num_ads; i++)
632 free_ads_entry(inode->ads_entries[i]);
633 FREE(inode->ads_entries);
637 /* Frees an inode. */
638 void free_inode(struct inode *inode)
641 inode_free_ads_entries(inode);
643 wimlib_assert(inode->num_opened_fds == 0);
650 /* Decrements link count on an inode and frees it if the link count reaches 0.
652 struct inode *put_inode(struct inode *inode)
655 wimlib_assert(inode->link_count);
656 if (--inode->link_count == 0) {
658 if (inode->num_opened_fds == 0)
669 /* Frees a WIM dentry.
671 * The inode is freed only if its link count is decremented to 0.
673 struct inode *free_dentry(struct dentry *dentry)
675 wimlib_assert(dentry);
678 FREE(dentry->file_name);
679 FREE(dentry->file_name_utf8);
680 FREE(dentry->short_name);
681 FREE(dentry->full_path_utf8);
682 inode = put_inode(dentry->inode);
687 void put_dentry(struct dentry *dentry)
689 wimlib_assert(dentry);
690 wimlib_assert(dentry->refcnt);
692 if (--dentry->refcnt == 0)
697 /* Partically clones a dentry.
700 * - memory for file names is not cloned (the pointers are all set to NULL
701 * and the lengths are set to zero)
702 * - next, prev, and children pointers and not touched
704 struct dentry *clone_dentry(struct dentry *old)
706 struct dentry *new = MALLOC(sizeof(struct dentry));
709 memcpy(new, old, sizeof(struct dentry));
710 new->file_name = NULL;
711 new->file_name_len = 0;
712 new->file_name_utf8 = NULL;
713 new->file_name_utf8_len = 0;
714 new->short_name = NULL;
715 new->short_name_len = 0;
721 * This function is passed as an argument to for_dentry_in_tree_depth() in order
722 * to free a directory tree. __args is a pointer to a `struct free_dentry_args'.
724 static int do_free_dentry(struct dentry *dentry, void *__lookup_table)
726 struct lookup_table *lookup_table = __lookup_table;
727 struct lookup_table_entry *lte;
728 struct inode *inode = dentry->inode;
732 wimlib_assert(inode->link_count);
733 for (i = 0; i <= inode->num_ads; i++) {
734 lte = inode_stream_lte(inode, i, lookup_table);
735 lte_decrement_refcnt(lte, lookup_table);
739 wimlib_assert(dentry->refcnt != 0);
740 if (--dentry->refcnt == 0)
746 * Unlinks and frees a dentry tree.
748 * @root: The root of the tree.
749 * @lookup_table: The lookup table for dentries. If non-NULL, the
750 * reference counts in the lookup table for the lookup
751 * table entries corresponding to the dentries will be
754 void free_dentry_tree(struct dentry *root, struct lookup_table *lookup_table)
756 if (!root || !root->parent)
758 for_dentry_in_tree_depth(root, do_free_dentry, lookup_table);
761 int increment_dentry_refcnt(struct dentry *dentry, void *ignore)
768 * Links a dentry into the directory tree.
770 * @dentry: The dentry to link.
771 * @parent: The dentry that will be the parent of @dentry.
773 void link_dentry(struct dentry *dentry, struct dentry *parent)
775 wimlib_assert(dentry_is_directory(parent));
776 dentry->parent = parent;
777 if (parent->inode->children) {
778 /* Not an only child; link to siblings. */
779 dentry->next = parent->inode->children;
780 dentry->prev = parent->inode->children->prev;
781 dentry->next->prev = dentry;
782 dentry->prev->next = dentry;
784 /* Only child; link to parent. */
785 parent->inode->children = dentry;
786 dentry->next = dentry;
787 dentry->prev = dentry;
793 * Unlink a dentry from the directory tree.
795 * Note: This merely removes it from the in-memory tree structure.
797 void unlink_dentry(struct dentry *dentry)
799 if (dentry_is_root(dentry))
801 if (dentry_is_only_child(dentry)) {
802 dentry->parent->inode->children = NULL;
804 if (dentry_is_first_sibling(dentry))
805 dentry->parent->inode->children = dentry->next;
806 dentry->next->prev = dentry->prev;
807 dentry->prev->next = dentry->next;
811 /* Duplicates a UTF-8 name into UTF-8 and UTF-16 strings and returns the strings
812 * and their lengths in the pointer arguments */
813 int get_names(char **name_utf16_ret, char **name_utf8_ret,
814 u16 *name_utf16_len_ret, u16 *name_utf8_len_ret,
819 char *name_utf16, *name_utf8;
821 utf8_len = strlen(name);
823 name_utf16 = utf8_to_utf16(name, utf8_len, &utf16_len);
826 return WIMLIB_ERR_NOMEM;
828 name_utf8 = MALLOC(utf8_len + 1);
831 return WIMLIB_ERR_NOMEM;
833 memcpy(name_utf8, name, utf8_len + 1);
834 FREE(*name_utf8_ret);
835 FREE(*name_utf16_ret);
836 *name_utf8_ret = name_utf8;
837 *name_utf16_ret = name_utf16;
838 *name_utf8_len_ret = utf8_len;
839 *name_utf16_len_ret = utf16_len;
843 /* Changes the name of a dentry to @new_name. Only changes the file_name and
844 * file_name_utf8 fields; does not change the short_name, short_name_utf8, or
845 * full_path_utf8 fields. Also recalculates its length. */
846 int change_dentry_name(struct dentry *dentry, const char *new_name)
850 ret = get_names(&dentry->file_name, &dentry->file_name_utf8,
851 &dentry->file_name_len, &dentry->file_name_utf8_len,
853 FREE(dentry->short_name);
854 dentry->short_name_len = 0;
856 dentry->length = dentry_correct_length(dentry);
861 * Changes the name of an alternate data stream */
862 int change_ads_name(struct ads_entry *entry, const char *new_name)
864 return get_names(&entry->stream_name, &entry->stream_name_utf8,
865 &entry->stream_name_len,
866 &entry->stream_name_utf8_len,
870 /* Parameters for calculate_dentry_statistics(). */
871 struct image_statistics {
872 struct lookup_table *lookup_table;
876 u64 *hard_link_bytes;
879 static int calculate_dentry_statistics(struct dentry *dentry, void *arg)
881 struct image_statistics *stats;
882 struct lookup_table_entry *lte;
886 if (dentry_is_directory(dentry) && !dentry_is_root(dentry))
889 ++*stats->file_count;
891 for (unsigned i = 0; i <= dentry->inode->num_ads; i++) {
892 lte = inode_stream_lte(dentry->inode, i, stats->lookup_table);
894 *stats->total_bytes += wim_resource_size(lte);
895 if (++lte->out_refcnt == 1)
896 *stats->hard_link_bytes += wim_resource_size(lte);
902 /* Calculates some statistics about a dentry tree. */
903 void calculate_dir_tree_statistics(struct dentry *root, struct lookup_table *table,
904 u64 *dir_count_ret, u64 *file_count_ret,
905 u64 *total_bytes_ret,
906 u64 *hard_link_bytes_ret)
908 struct image_statistics stats;
911 *total_bytes_ret = 0;
912 *hard_link_bytes_ret = 0;
913 stats.lookup_table = table;
914 stats.dir_count = dir_count_ret;
915 stats.file_count = file_count_ret;
916 stats.total_bytes = total_bytes_ret;
917 stats.hard_link_bytes = hard_link_bytes_ret;
918 for_lookup_table_entry(table, lte_zero_out_refcnt, NULL);
919 for_dentry_in_tree(root, calculate_dentry_statistics, &stats);
924 * Reads the alternate data stream entries for a dentry.
926 * @p: Pointer to buffer that starts with the first alternate stream entry.
928 * @inode: Inode to load the alternate data streams into.
929 * @inode->num_ads must have been set to the number of
930 * alternate data streams that are expected.
932 * @remaining_size: Number of bytes of data remaining in the buffer pointed
935 * The format of the on-disk alternate stream entries is as follows:
937 * struct ads_entry_on_disk {
938 * u64 length; // Length of the entry, in bytes. This includes
939 * all fields (including the stream name and
940 * null terminator if present, AND the padding!).
941 * u64 reserved; // Seems to be unused
942 * u8 hash[20]; // SHA1 message digest of the uncompressed stream
943 * u16 stream_name_len; // Length of the stream name, in bytes
944 * char stream_name[]; // Stream name in UTF-16LE, @stream_name_len bytes long,
945 * not including null terminator
946 * u16 zero; // UTF-16 null terminator for the stream name, NOT
947 * included in @stream_name_len. Based on what
948 * I've observed from filenames in dentries,
949 * this field should not exist when
950 * (@stream_name_len == 0), but you can't
951 * actually tell because of the padding anyway
952 * (provided that the padding is zeroed, which
953 * it always seems to be).
954 * char padding[]; // Padding to make the size a multiple of 8 bytes.
957 * In addition, the entries are 8-byte aligned.
959 * Return 0 on success or nonzero on failure. On success, inode->ads_entries
960 * is set to an array of `struct ads_entry's of length inode->num_ads. On
961 * failure, @inode is not modified.
963 static int read_ads_entries(const u8 *p, struct inode *inode,
967 struct ads_entry **ads_entries;
970 num_ads = inode->num_ads;
971 ads_entries = CALLOC(num_ads, sizeof(inode->ads_entries[0]));
973 ERROR("Could not allocate memory for %"PRIu16" "
974 "alternate data stream entries", num_ads);
975 return WIMLIB_ERR_NOMEM;
978 for (u16 i = 0; i < num_ads; i++) {
979 struct ads_entry *cur_entry;
981 u64 length_no_padding;
984 const u8 *p_save = p;
986 cur_entry = new_ads_entry(NULL);
988 ret = WIMLIB_ERR_NOMEM;
989 goto out_free_ads_entries;
992 ads_entries[i] = cur_entry;
995 ads_entries[i]->stream_id = i + 1;
998 /* Read the base stream entry, excluding the stream name. */
999 if (remaining_size < WIM_ADS_ENTRY_DISK_SIZE) {
1000 ERROR("Stream entries go past end of metadata resource");
1001 ERROR("(remaining_size = %"PRIu64")", remaining_size);
1002 ret = WIMLIB_ERR_INVALID_DENTRY;
1003 goto out_free_ads_entries;
1006 p = get_u64(p, &length);
1007 p += 8; /* Skip the reserved field */
1008 p = get_bytes(p, SHA1_HASH_SIZE, (u8*)cur_entry->hash);
1009 p = get_u16(p, &cur_entry->stream_name_len);
1011 cur_entry->stream_name = NULL;
1012 cur_entry->stream_name_utf8 = NULL;
1014 /* Length including neither the null terminator nor the padding
1016 length_no_padding = WIM_ADS_ENTRY_DISK_SIZE +
1017 cur_entry->stream_name_len;
1019 /* Length including the null terminator and the padding */
1020 total_length = ((length_no_padding + 2) + 7) & ~7;
1022 wimlib_assert(total_length == ads_entry_total_length(cur_entry));
1024 if (remaining_size < length_no_padding) {
1025 ERROR("Stream entries go past end of metadata resource");
1026 ERROR("(remaining_size = %"PRIu64" bytes, "
1027 "length_no_padding = %"PRIu64" bytes)",
1028 remaining_size, length_no_padding);
1029 ret = WIMLIB_ERR_INVALID_DENTRY;
1030 goto out_free_ads_entries;
1033 /* The @length field in the on-disk ADS entry is expected to be
1034 * equal to @total_length, which includes all of the entry and
1035 * the padding that follows it to align the next ADS entry to an
1036 * 8-byte boundary. However, to be safe, we'll accept the
1037 * length field as long as it's not less than the un-padded
1038 * total length and not more than the padded total length. */
1039 if (length < length_no_padding || length > total_length) {
1040 ERROR("Stream entry has unexpected length "
1041 "field (length field = %"PRIu64", "
1042 "unpadded total length = %"PRIu64", "
1043 "padded total length = %"PRIu64")",
1044 length, length_no_padding, total_length);
1045 ret = WIMLIB_ERR_INVALID_DENTRY;
1046 goto out_free_ads_entries;
1049 if (cur_entry->stream_name_len) {
1050 cur_entry->stream_name = MALLOC(cur_entry->stream_name_len);
1051 if (!cur_entry->stream_name) {
1052 ret = WIMLIB_ERR_NOMEM;
1053 goto out_free_ads_entries;
1055 get_bytes(p, cur_entry->stream_name_len,
1056 (u8*)cur_entry->stream_name);
1057 cur_entry->stream_name_utf8 = utf16_to_utf8(cur_entry->stream_name,
1058 cur_entry->stream_name_len,
1060 cur_entry->stream_name_utf8_len = utf8_len;
1062 if (!cur_entry->stream_name_utf8) {
1063 ret = WIMLIB_ERR_NOMEM;
1064 goto out_free_ads_entries;
1067 /* It's expected that the size of every ADS entry is a multiple
1068 * of 8. However, to be safe, I'm allowing the possibility of
1069 * an ADS entry at the very end of the metadata resource ending
1070 * un-aligned. So although we still need to increment the input
1071 * pointer by @total_length to reach the next ADS entry, it's
1072 * possible that less than @total_length is actually remaining
1073 * in the metadata resource. We should set the remaining size to
1074 * 0 bytes if this happens. */
1075 p = p_save + total_length;
1076 if (remaining_size < total_length)
1079 remaining_size -= total_length;
1081 inode->ads_entries = ads_entries;
1083 inode->next_stream_id = inode->num_ads + 1;
1086 out_free_ads_entries:
1087 for (u16 i = 0; i < num_ads; i++)
1088 free_ads_entry(ads_entries[i]);
1094 * Reads a directory entry, including all alternate data stream entries that
1095 * follow it, from the WIM image's metadata resource.
1097 * @metadata_resource: Buffer containing the uncompressed metadata resource.
1098 * @metadata_resource_len: Length of the metadata resource.
1099 * @offset: Offset of this directory entry in the metadata resource.
1100 * @dentry: A `struct dentry' that will be filled in by this function.
1102 * Return 0 on success or nonzero on failure. On failure, @dentry have been
1103 * modified, bu it will be left with no pointers to any allocated buffers.
1104 * On success, the dentry->length field must be examined. If zero, this was a
1105 * special "end of directory" dentry and not a real dentry. If nonzero, this
1106 * was a real dentry.
1108 int read_dentry(const u8 metadata_resource[], u64 metadata_resource_len,
1109 u64 offset, struct dentry *dentry)
1112 u64 calculated_size;
1113 char *file_name = NULL;
1114 char *file_name_utf8 = NULL;
1115 char *short_name = NULL;
1118 size_t file_name_utf8_len = 0;
1120 struct inode *inode = NULL;
1122 dentry_common_init(dentry);
1124 /*Make sure the dentry really fits into the metadata resource.*/
1125 if (offset + 8 > metadata_resource_len || offset + 8 < offset) {
1126 ERROR("Directory entry starting at %"PRIu64" ends past the "
1127 "end of the metadata resource (size %"PRIu64")",
1128 offset, metadata_resource_len);
1129 return WIMLIB_ERR_INVALID_DENTRY;
1132 /* Before reading the whole dentry, we need to read just the length.
1133 * This is because a dentry of length 8 (that is, just the length field)
1134 * terminates the list of sibling directory entries. */
1136 p = get_u64(&metadata_resource[offset], &dentry->length);
1138 /* A zero length field (really a length of 8, since that's how big the
1139 * directory entry is...) indicates that this is the end of directory
1140 * dentry. We do not read it into memory as an actual dentry, so just
1141 * return successfully in that case. */
1142 if (dentry->length == 0)
1145 /* If the dentry does not overflow the metadata resource buffer and is
1146 * not too short, read the rest of it (excluding the alternate data
1147 * streams, but including the file name and short name variable-length
1148 * fields) into memory. */
1149 if (offset + dentry->length >= metadata_resource_len
1150 || offset + dentry->length < offset)
1152 ERROR("Directory entry at offset %"PRIu64" and with size "
1153 "%"PRIu64" ends past the end of the metadata resource "
1155 offset, dentry->length, metadata_resource_len);
1156 return WIMLIB_ERR_INVALID_DENTRY;
1159 if (dentry->length < WIM_DENTRY_DISK_SIZE) {
1160 ERROR("Directory entry has invalid length of %"PRIu64" bytes",
1162 return WIMLIB_ERR_INVALID_DENTRY;
1165 inode = new_timeless_inode();
1167 return WIMLIB_ERR_NOMEM;
1169 p = get_u32(p, &inode->attributes);
1170 p = get_u32(p, (u32*)&inode->security_id);
1171 p = get_u64(p, &dentry->subdir_offset);
1173 /* 2 unused fields */
1174 p += 2 * sizeof(u64);
1175 /*p = get_u64(p, &dentry->unused1);*/
1176 /*p = get_u64(p, &dentry->unused2);*/
1178 p = get_u64(p, &inode->creation_time);
1179 p = get_u64(p, &inode->last_access_time);
1180 p = get_u64(p, &inode->last_write_time);
1182 p = get_bytes(p, SHA1_HASH_SIZE, inode->hash);
1185 * I don't know what's going on here. It seems like M$ screwed up the
1186 * reparse points, then put the fields in the same place and didn't
1187 * document it. The WIM_HDR_FLAG_RP_FIX flag in the WIM header might
1188 * have something to do with this, but it's not documented.
1190 if (inode->attributes & FILE_ATTRIBUTE_REPARSE_POINT) {
1193 p = get_u32(p, &inode->reparse_tag);
1196 p = get_u32(p, &inode->reparse_tag);
1197 p = get_u64(p, &inode->ino);
1200 /* By the way, the reparse_reserved field does not actually exist (at
1201 * least when the file is not a reparse point) */
1203 p = get_u16(p, &inode->num_ads);
1205 p = get_u16(p, &short_name_len);
1206 p = get_u16(p, &file_name_len);
1208 /* We now know the length of the file name and short name. Make sure
1209 * the length of the dentry is large enough to actually hold them.
1211 * The calculated length here is unaligned to allow for the possibility
1212 * that the dentry->length names an unaligned length, although this
1213 * would be unexpected. */
1214 calculated_size = __dentry_correct_length_unaligned(file_name_len,
1217 if (dentry->length < calculated_size) {
1218 ERROR("Unexpected end of directory entry! (Expected "
1219 "at least %"PRIu64" bytes, got %"PRIu64" bytes. "
1220 "short_name_len = %hu, file_name_len = %hu)",
1221 calculated_size, dentry->length,
1222 short_name_len, file_name_len);
1223 return WIMLIB_ERR_INVALID_DENTRY;
1226 /* Read the filename if present. Note: if the filename is empty, there
1227 * is no null terminator following it. */
1228 if (file_name_len) {
1229 file_name = MALLOC(file_name_len);
1231 ERROR("Failed to allocate %hu bytes for dentry file name",
1233 return WIMLIB_ERR_NOMEM;
1235 p = get_bytes(p, file_name_len, file_name);
1237 /* Convert filename to UTF-8. */
1238 file_name_utf8 = utf16_to_utf8(file_name, file_name_len,
1239 &file_name_utf8_len);
1241 if (!file_name_utf8) {
1242 ERROR("Failed to allocate memory to convert UTF-16 "
1243 "filename (%hu bytes) to UTF-8", file_name_len);
1244 ret = WIMLIB_ERR_NOMEM;
1245 goto out_free_file_name;
1248 WARNING("Expected two zero bytes following the file name "
1249 "`%s', but found non-zero bytes", file_name_utf8);
1253 /* Align the calculated size */
1254 calculated_size = (calculated_size + 7) & ~7;
1256 if (dentry->length > calculated_size) {
1257 /* Weird; the dentry says it's longer than it should be. Note
1258 * that the length field does NOT include the size of the
1259 * alternate stream entries. */
1261 /* Strangely, some directory entries inexplicably have a little
1262 * over 70 bytes of extra data. The exact amount of data seems
1263 * to be 72 bytes, but it is aligned on the next 8-byte
1264 * boundary. It does NOT seem to be alternate data stream
1265 * entries. Here's an example of the aligned data:
1267 * 01000000 40000000 6c786bba c58ede11 b0bb0026 1870892a b6adb76f
1268 * e63a3e46 8fca8653 0d2effa1 6c786bba c58ede11 b0bb0026 1870892a
1269 * 00000000 00000000 00000000 00000000
1271 * Here's one interpretation of how the data is laid out.
1274 * u32 field1; (always 0x00000001)
1275 * u32 field2; (always 0x40000000)
1276 * u8 data[48]; (???)
1277 * u64 reserved1; (always 0)
1278 * u64 reserved2; (always 0)
1280 DEBUG("Dentry for file or directory `%s' has %zu extra "
1282 file_name_utf8, dentry->length - calculated_size);
1285 /* Read the short filename if present. Note: if there is no short
1286 * filename, there is no null terminator following it. */
1287 if (short_name_len) {
1288 short_name = MALLOC(short_name_len);
1290 ERROR("Failed to allocate %hu bytes for short filename",
1292 ret = WIMLIB_ERR_NOMEM;
1293 goto out_free_file_name_utf8;
1296 p = get_bytes(p, short_name_len, short_name);
1298 WARNING("Expected two zero bytes following the file name "
1299 "`%s', but found non-zero bytes", file_name_utf8);
1304 * Read the alternate data streams, if present. dentry->num_ads tells
1305 * us how many they are, and they will directly follow the dentry
1308 * Note that each alternate data stream entry begins on an 8-byte
1309 * aligned boundary, and the alternate data stream entries are NOT
1310 * included in the dentry->length field for some reason.
1312 if (inode->num_ads != 0) {
1313 if (calculated_size > metadata_resource_len - offset) {
1314 ERROR("Not enough space in metadata resource for "
1315 "alternate stream entries");
1316 ret = WIMLIB_ERR_INVALID_DENTRY;
1317 goto out_free_short_name;
1319 ret = read_ads_entries(&metadata_resource[offset + calculated_size],
1321 metadata_resource_len - offset - calculated_size);
1323 goto out_free_short_name;
1326 /* We've read all the data for this dentry. Set the names and their
1327 * lengths, and we've done. */
1328 dentry->inode = inode;
1329 dentry->file_name = file_name;
1330 dentry->file_name_utf8 = file_name_utf8;
1331 dentry->short_name = short_name;
1332 dentry->file_name_len = file_name_len;
1333 dentry->file_name_utf8_len = file_name_utf8_len;
1334 dentry->short_name_len = short_name_len;
1336 out_free_short_name:
1338 out_free_file_name_utf8:
1339 FREE(file_name_utf8);
1347 int verify_inode(struct inode *inode, const WIMStruct *w)
1349 const struct lookup_table *table = w->lookup_table;
1350 const struct wim_security_data *sd = wim_const_security_data(w);
1351 const struct dentry *first_dentry = inode_first_dentry(inode);
1352 int ret = WIMLIB_ERR_INVALID_DENTRY;
1354 /* Check the security ID */
1355 if (inode->security_id < -1) {
1356 ERROR("Dentry `%s' has an invalid security ID (%d)",
1357 first_dentry->full_path_utf8, inode->security_id);
1360 if (inode->security_id >= sd->num_entries) {
1361 ERROR("Dentry `%s' has an invalid security ID (%d) "
1362 "(there are only %u entries in the security table)",
1363 first_dentry->full_path_utf8, inode->security_id,
1368 /* Check that lookup table entries for all the resources exist, except
1369 * if the SHA1 message digest is all 0's, which indicates there is
1370 * intentionally no resource there. */
1371 if (w->hdr.total_parts == 1) {
1372 for (unsigned i = 0; i <= inode->num_ads; i++) {
1373 struct lookup_table_entry *lte;
1375 hash = inode_stream_hash_unresolved(inode, i);
1376 lte = __lookup_resource(table, hash);
1377 if (!lte && !is_zero_hash(hash)) {
1378 ERROR("Could not find lookup table entry for stream "
1379 "%u of dentry `%s'", i, first_dentry->full_path_utf8);
1382 if (lte && (lte->real_refcnt += inode->link_count) > lte->refcnt)
1384 #ifdef ENABLE_ERROR_MESSAGES
1385 WARNING("The following lookup table entry "
1386 "has a reference count of %u, but",
1388 WARNING("We found %zu references to it",
1390 WARNING("(One dentry referencing it is at `%s')",
1391 first_dentry->full_path_utf8);
1393 print_lookup_table_entry(lte);
1395 /* Guess what! install.wim for Windows 8
1396 * contains a stream with 2 dentries referencing
1397 * it, but the lookup table entry has reference
1398 * count of 1. So we will need to handle this
1399 * case and not just make it be an error... I'm
1400 * just setting the reference count to the
1401 * number of references we found.
1402 * (Unfortunately, even after doing this, the
1403 * reference count could be too low if it's also
1404 * referenced in other WIM images) */
1407 lte->refcnt = lte->real_refcnt;
1408 WARNING("Fixing reference count");
1416 /* Make sure there is only one un-named stream. */
1417 unsigned num_unnamed_streams = 0;
1418 for (unsigned i = 0; i <= inode->num_ads; i++) {
1420 hash = inode_stream_hash_unresolved(inode, i);
1421 if (!inode_stream_name_len(inode, i) && !is_zero_hash(hash))
1422 num_unnamed_streams++;
1424 if (num_unnamed_streams > 1) {
1425 ERROR("Dentry `%s' has multiple (%u) un-named streams",
1426 first_dentry->full_path_utf8, num_unnamed_streams);
1429 inode->verified = true;
1436 /* Run some miscellaneous verifications on a WIM dentry */
1437 int verify_dentry(struct dentry *dentry, void *wim)
1439 const WIMStruct *w = wim;
1440 const struct inode *inode = dentry->inode;
1441 int ret = WIMLIB_ERR_INVALID_DENTRY;
1443 if (!dentry->inode->verified) {
1444 ret = verify_inode(dentry->inode, w);
1449 /* Cannot have a short name but no long name */
1450 if (dentry->short_name_len && !dentry->file_name_len) {
1451 ERROR("Dentry `%s' has a short name but no long name",
1452 dentry->full_path_utf8);
1456 /* Make sure root dentry is unnamed */
1457 if (dentry_is_root(dentry)) {
1458 if (dentry->file_name_len) {
1459 ERROR("The root dentry is named `%s', but it must "
1460 "be unnamed", dentry->file_name_utf8);
1466 /* Check timestamps */
1467 if (inode->last_access_time < inode->creation_time ||
1468 inode->last_write_time < inode->creation_time) {
1469 WARNING("Dentry `%s' was created after it was last accessed or "
1470 "written to", dentry->full_path_utf8);
1480 * Writes a WIM dentry to an output buffer.
1482 * @dentry: The dentry structure.
1483 * @p: The memory location to write the data to.
1484 * @return: Pointer to the byte after the last byte we wrote as part of the
1487 static u8 *write_dentry(const struct dentry *dentry, u8 *p)
1491 const struct inode *inode = dentry->inode;
1493 /* We calculate the correct length of the dentry ourselves because the
1494 * dentry->length field may been set to an unexpected value from when we
1495 * read the dentry in (for example, there may have been unknown data
1496 * appended to the end of the dentry...) */
1497 u64 length = dentry_correct_length(dentry);
1499 p = put_u64(p, length);
1500 p = put_u32(p, inode->attributes);
1501 p = put_u32(p, inode->security_id);
1502 p = put_u64(p, dentry->subdir_offset);
1503 p = put_u64(p, 0); /* unused1 */
1504 p = put_u64(p, 0); /* unused2 */
1505 p = put_u64(p, inode->creation_time);
1506 p = put_u64(p, inode->last_access_time);
1507 p = put_u64(p, inode->last_write_time);
1508 hash = inode_stream_hash(inode, 0);
1509 p = put_bytes(p, SHA1_HASH_SIZE, hash);
1510 if (inode->attributes & FILE_ATTRIBUTE_REPARSE_POINT) {
1511 p = put_zeroes(p, 4);
1512 p = put_u32(p, inode->reparse_tag);
1513 p = put_zeroes(p, 4);
1517 if (inode->link_count == 1)
1520 link_group_id = inode->ino;
1521 p = put_u64(p, link_group_id);
1523 p = put_u16(p, inode->num_ads);
1524 p = put_u16(p, dentry->short_name_len);
1525 p = put_u16(p, dentry->file_name_len);
1526 if (dentry->file_name_len) {
1527 p = put_bytes(p, dentry->file_name_len, (u8*)dentry->file_name);
1528 p = put_u16(p, 0); /* filename padding, 2 bytes. */
1530 if (dentry->short_name) {
1531 p = put_bytes(p, dentry->short_name_len, (u8*)dentry->short_name);
1532 p = put_u16(p, 0); /* short name padding, 2 bytes */
1535 /* Align to 8-byte boundary */
1536 wimlib_assert(length >= (p - orig_p)
1537 && length - (p - orig_p) <= 7);
1538 p = put_zeroes(p, length - (p - orig_p));
1540 /* Write the alternate data streams, if there are any. Please see
1541 * read_ads_entries() for comments about the format of the on-disk
1542 * alternate data stream entries. */
1543 for (u16 i = 0; i < inode->num_ads; i++) {
1544 p = put_u64(p, ads_entry_total_length(inode->ads_entries[i]));
1545 p = put_u64(p, 0); /* Unused */
1546 hash = inode_stream_hash(inode, i + 1);
1547 p = put_bytes(p, SHA1_HASH_SIZE, hash);
1548 p = put_u16(p, inode->ads_entries[i]->stream_name_len);
1549 if (inode->ads_entries[i]->stream_name_len) {
1550 p = put_bytes(p, inode->ads_entries[i]->stream_name_len,
1551 (u8*)inode->ads_entries[i]->stream_name);
1554 p = put_zeroes(p, (8 - (p - orig_p) % 8) % 8);
1556 #ifdef ENABLE_ASSERTIONS
1557 wimlib_assert(p - orig_p == __dentry_total_length(dentry, length));
1562 /* Recursive function that writes a dentry tree rooted at @parent, not including
1563 * @parent itself, which has already been written. */
1564 static u8 *write_dentry_tree_recursive(const struct dentry *parent, u8 *p)
1566 const struct dentry *child;
1568 /* Nothing to do if this dentry has no children. */
1569 if (parent->subdir_offset == 0)
1572 /* Write child dentries and end-of-directory entry.
1574 * Note: we need to write all of this dentry's children before
1575 * recursively writing the directory trees rooted at each of the child
1576 * dentries, since the on-disk dentries for a dentry's children are
1577 * always located at consecutive positions in the metadata resource! */
1578 child = parent->inode->children;
1581 p = write_dentry(child, p);
1582 child = child->next;
1583 } while (child != parent->inode->children);
1586 /* write end of directory entry */
1589 /* Recurse on children. */
1592 p = write_dentry_tree_recursive(child, p);
1593 child = child->next;
1594 } while (child != parent->inode->children);
1599 /* Writes a directory tree to the metadata resource.
1601 * @root: Root of the dentry tree.
1602 * @p: Pointer to a buffer with enough space for the dentry tree.
1604 * Returns pointer to the byte after the last byte we wrote.
1606 u8 *write_dentry_tree(const struct dentry *root, u8 *p)
1608 wimlib_assert(dentry_is_root(root));
1610 /* If we're the root dentry, we have no parent that already
1611 * wrote us, so we need to write ourselves. */
1612 p = write_dentry(root, p);
1614 /* Write end of directory entry after the root dentry just to be safe;
1615 * however the root dentry obviously cannot have any siblings. */
1618 /* Recursively write the rest of the dentry tree. */
1619 return write_dentry_tree_recursive(root, p);
1622 /* Reads the children of a dentry, and all their children, ..., etc. from the
1623 * metadata resource and into the dentry tree.
1625 * @metadata_resource: An array that contains the uncompressed metadata
1626 * resource for the WIM file.
1628 * @metadata_resource_len: The length of the uncompressed metadata resource, in
1631 * @dentry: A pointer to a `struct dentry' that is the root of the directory
1632 * tree and has already been read from the metadata resource. It
1633 * does not need to be the real root because this procedure is
1634 * called recursively.
1636 * @return: Zero on success, nonzero on failure.
1638 int read_dentry_tree(const u8 metadata_resource[], u64 metadata_resource_len,
1639 struct dentry *dentry)
1641 u64 cur_offset = dentry->subdir_offset;
1642 struct dentry *prev_child = NULL;
1643 struct dentry *first_child = NULL;
1644 struct dentry *child;
1645 struct dentry cur_child;
1649 * If @dentry has no child dentries, nothing more needs to be done for
1650 * this branch. This is the case for regular files, symbolic links, and
1651 * *possibly* empty directories (although an empty directory may also
1652 * have one child dentry that is the special end-of-directory dentry)
1654 if (cur_offset == 0)
1657 /* Find and read all the children of @dentry. */
1660 /* Read next child of @dentry into @cur_child. */
1661 ret = read_dentry(metadata_resource, metadata_resource_len,
1662 cur_offset, &cur_child);
1666 /* Check for end of directory. */
1667 if (cur_child.length == 0)
1670 /* Not end of directory. Allocate this child permanently and
1671 * link it to the parent and previous child. */
1672 child = MALLOC(sizeof(struct dentry));
1674 ERROR("Failed to allocate %zu bytes for new dentry",
1675 sizeof(struct dentry));
1676 ret = WIMLIB_ERR_NOMEM;
1679 memcpy(child, &cur_child, sizeof(struct dentry));
1682 prev_child->next = child;
1683 child->prev = prev_child;
1685 first_child = child;
1688 child->parent = dentry;
1690 list_add(&child->inode_dentry_list, &child->inode->dentry_list);
1692 /* If there are children of this child, call this procedure
1694 if (child->subdir_offset != 0) {
1695 ret = read_dentry_tree(metadata_resource,
1696 metadata_resource_len, child);
1701 /* Advance to the offset of the next child. Note: We need to
1702 * advance by the TOTAL length of the dentry, not by the length
1703 * child->length, which although it does take into account the
1704 * padding, it DOES NOT take into account alternate stream
1706 cur_offset += dentry_total_length(child);
1709 /* Link last child to first one, and set parent's children pointer to
1710 * the first child. */
1712 prev_child->next = first_child;
1713 first_child->prev = prev_child;
1715 dentry->inode->children = first_child;