/* * dentry.c * * A dentry (directory entry) contains the metadata for a file. In the WIM file * format, the dentries are stored in the "metadata resource" section right * after the security data. Each image in the WIM file has its own metadata * resource with its own security data and dentry tree. Dentries in different * images may share file resources by referring to the same lookup table * entries. */ /* * Copyright (C) 2012 Eric Biggers * * This file is part of wimlib, a library for working with WIM files. * * wimlib is free software; you can redistribute it and/or modify it under the * terms of the GNU General Public License as published by the Free Software * Foundation; either version 3 of the License, or (at your option) any later * version. * * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR * A PARTICULAR PURPOSE. See the GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along with * wimlib; if not, see http://www.gnu.org/licenses/. */ #include "buffer_io.h" #include "dentry.h" #include "lookup_table.h" #include "timestamp.h" #include "wimlib_internal.h" /* Calculates the unaligned length, in bytes, of an on-disk WIM dentry that has * a file name and short name that take the specified numbers of bytes. This * excludes any alternate data stream entries that may follow the dentry. */ static u64 __dentry_correct_length_unaligned(u16 file_name_len, u16 short_name_len) { u64 length = WIM_DENTRY_DISK_SIZE; if (file_name_len) length += file_name_len + 2; if (short_name_len) length += short_name_len + 2; return length; } /* Calculates the unaligned length, in bytes, of an on-disk WIM dentry, based on * the file name length and short name length. Note that dentry->length is * ignored; also, this excludes any alternate data stream entries that may * follow the dentry. */ static u64 dentry_correct_length_unaligned(const struct dentry *dentry) { return __dentry_correct_length_unaligned(dentry->file_name_len, dentry->short_name_len); } /* Return the "correct" value to write in the length field of a WIM dentry, * based on the file name length and short name length. */ static u64 dentry_correct_length(const struct dentry *dentry) { return (dentry_correct_length_unaligned(dentry) + 7) & ~7; } /* Return %true iff the alternate data stream entry @entry has the UTF-8 stream * name @name that has length @name_len bytes. */ static inline bool ads_entry_has_name(const struct ads_entry *entry, const char *name, size_t name_len) { if (entry->stream_name_utf8_len != name_len) return false; return memcmp(entry->stream_name_utf8, name, name_len) == 0; } /* Duplicates a UTF-8 name into UTF-8 and UTF-16 strings and returns the strings * and their lengths in the pointer arguments */ int get_names(char **name_utf16_ret, char **name_utf8_ret, u16 *name_utf16_len_ret, u16 *name_utf8_len_ret, const char *name) { size_t utf8_len; size_t utf16_len; char *name_utf16, *name_utf8; int ret; utf8_len = strlen(name); ret = utf8_to_utf16(name, utf8_len, &name_utf16, &utf16_len); if (ret != 0) return ret; name_utf8 = MALLOC(utf8_len + 1); if (!name_utf8) { FREE(name_utf8); return WIMLIB_ERR_NOMEM; } memcpy(name_utf8, name, utf8_len + 1); FREE(*name_utf8_ret); FREE(*name_utf16_ret); *name_utf8_ret = name_utf8; *name_utf16_ret = name_utf16; *name_utf8_len_ret = utf8_len; *name_utf16_len_ret = utf16_len; return 0; } /* Changes the name of a dentry to @new_name. Only changes the file_name and * file_name_utf8 fields; does not change the short_name, short_name_utf8, or * full_path_utf8 fields. Also recalculates its length. */ static int change_dentry_name(struct dentry *dentry, const char *new_name) { int ret; ret = get_names(&dentry->file_name, &dentry->file_name_utf8, &dentry->file_name_len, &dentry->file_name_utf8_len, new_name); if (ret == 0) { if (dentry->short_name_len) { FREE(dentry->short_name); dentry->short_name_len = 0; } dentry->length = dentry_correct_length(dentry); } return ret; } /* * Changes the name of an alternate data stream */ static int change_ads_name(struct ads_entry *entry, const char *new_name) { return get_names(&entry->stream_name, &entry->stream_name_utf8, &entry->stream_name_len, &entry->stream_name_utf8_len, new_name); } /* Returns the total length of a WIM alternate data stream entry on-disk, * including the stream name, the null terminator, AND the padding after the * entry to align the next one (or the next dentry) on an 8-byte boundary. */ static u64 ads_entry_total_length(const struct ads_entry *entry) { u64 len = WIM_ADS_ENTRY_DISK_SIZE; if (entry->stream_name_len) len += entry->stream_name_len + 2; return (len + 7) & ~7; } static u64 __dentry_total_length(const struct dentry *dentry, u64 length) { const struct inode *inode = dentry->d_inode; for (u16 i = 0; i < inode->num_ads; i++) length += ads_entry_total_length(&inode->ads_entries[i]); return (length + 7) & ~7; } /* Calculate the aligned *total* length of an on-disk WIM dentry. This includes * all alternate data streams. */ u64 dentry_correct_total_length(const struct dentry *dentry) { return __dentry_total_length(dentry, dentry_correct_length_unaligned(dentry)); } /* Like dentry_correct_total_length(), but use the existing dentry->length field * instead of calculating its "correct" value. */ static u64 dentry_total_length(const struct dentry *dentry) { return __dentry_total_length(dentry, dentry->length); } int for_dentry_in_rbtree(struct rb_node *root, int (*visitor)(struct dentry *, void *), void *arg) { int ret; struct rb_node *node = root; LIST_HEAD(stack); while (true) { if (node) { list_add(&rbnode_dentry(node)->tmp_list, &stack); node = node->rb_left; } else { struct list_head *next; struct dentry *dentry; next = stack.next; if (next == &stack) return 0; dentry = container_of(next, struct dentry, tmp_list); list_del(next); ret = visitor(dentry, arg); if (ret != 0) return ret; node = dentry->rb_node.rb_right; } } } static int for_dentry_tree_in_rbtree_depth(struct rb_node *node, int (*visitor)(struct dentry*, void*), void *arg) { int ret; if (node) { ret = for_dentry_tree_in_rbtree_depth(node->rb_left, visitor, arg); if (ret != 0) return ret; ret = for_dentry_tree_in_rbtree_depth(node->rb_right, visitor, arg); if (ret != 0) return ret; ret = for_dentry_in_tree_depth(rbnode_dentry(node), visitor, arg); if (ret != 0) return ret; } return 0; } /*#define RECURSIVE_FOR_DENTRY_IN_TREE*/ #ifdef RECURSIVE_FOR_DENTRY_IN_TREE static int for_dentry_tree_in_rbtree(struct rb_node *node, int (*visitor)(struct dentry*, void*), void *arg) { int ret; if (node) { ret = for_dentry_tree_in_rbtree(node->rb_left, visitor, arg); if (ret != 0) return ret; ret = for_dentry_in_tree(rbnode_dentry(node), visitor, arg); if (ret != 0) return ret; ret = for_dentry_tree_in_rbtree(node->rb_right, visitor, arg); if (ret != 0) return ret; } return 0; } #endif /* * Calls a function on all directory entries in a WIM dentry tree. Logically, * this is a pre-order traversal (the function is called on a parent dentry * before its children), but sibling dentries will be visited in order as well. * * In reality, the data structures are more complicated than the above might * suggest because there is a separate red-black tree for each dentry that * contains its direct children. */ int for_dentry_in_tree(struct dentry *root, int (*visitor)(struct dentry*, void*), void *arg) { #ifdef RECURSIVE_FOR_DENTRY_IN_TREE int ret = visitor(root, arg); if (ret != 0) return ret; return for_dentry_tree_in_rbtree(root->d_inode->children.rb_node, visitor, arg); #else int ret; struct list_head main_stack; struct list_head sibling_stack; struct list_head *sibling_stack_bottom; struct dentry *main_dentry; struct rb_node *node; struct list_head *next_sibling; struct dentry *dentry; ret = visitor(root, arg); if (ret != 0) return ret; main_dentry = root; sibling_stack_bottom = &sibling_stack; INIT_LIST_HEAD(&main_stack); INIT_LIST_HEAD(&sibling_stack); list_add(&root->tmp_list, &main_stack); node = root->d_inode->children.rb_node; while (1) { // Prepare for non-recursive in-order traversal of the red-black // tree of this dentry's children while (node) { // Push this node to the sibling stack and examine the // left neighbor, if any list_add(&rbnode_dentry(node)->tmp_list, &sibling_stack); node = node->rb_left; } next_sibling = sibling_stack.next; if (next_sibling == sibling_stack_bottom) { // Done with all siblings. Pop the main dentry to move // back up one level. main_dentry = container_of(main_stack.next, struct dentry, tmp_list); list_del(&main_dentry->tmp_list); if (main_dentry == root) goto out; // Restore sibling stack bottom from the previous level sibling_stack_bottom = (void*)main_dentry->parent; // Restore the just-popped main dentry's parent main_dentry->parent = container_of(main_stack.next, struct dentry, tmp_list); // The next sibling to traverse in the previous level, // in the in-order traversal of the red-black tree, is // the one to the right. node = main_dentry->rb_node.rb_right; } else { // The sibling stack is not empty, so there are more to // go! // Pop a sibling from the stack. list_del(next_sibling); dentry = container_of(next_sibling, struct dentry, tmp_list); // Visit the sibling. ret = visitor(dentry, arg); if (ret != 0) { // Failed. Restore parent pointers for the // dentries in the main stack list_for_each_entry(dentry, &main_stack, tmp_list) { dentry->parent = container_of(dentry->tmp_list.next, struct dentry, tmp_list); } goto out; } // We'd like to recursively visit the dentry tree rooted // at this sibling. To do this, add it to the main // stack, save the bottom of this level's sibling stack // in the dentry->parent field, re-set the bottom of the // sibling stack to be its current height, and set // main_dentry to the sibling so it becomes the parent // dentry in the next iteration through the outer loop. if (inode_has_children(dentry->d_inode)) { list_add(&dentry->tmp_list, &main_stack); dentry->parent = (void*)sibling_stack_bottom; sibling_stack_bottom = sibling_stack.next; main_dentry = dentry; node = main_dentry->d_inode->children.rb_node; } else { node = dentry->rb_node.rb_right; } } } out: root->parent = root; return ret; #endif } /* * Like for_dentry_in_tree(), but the visitor function is always called on a * dentry's children before on itself. */ int for_dentry_in_tree_depth(struct dentry *root, int (*visitor)(struct dentry*, void*), void *arg) { #if 1 int ret; ret = for_dentry_tree_in_rbtree_depth(root->d_inode->children.rb_node, visitor, arg); if (ret != 0) return ret; return visitor(root, arg); #else int ret; struct list_head main_stack; struct list_head sibling_stack; struct list_head *sibling_stack_bottom; struct dentry *main_dentry; struct rb_node *node; struct list_head *next_sibling; struct dentry *dentry; main_dentry = root; sibling_stack_bottom = &sibling_stack; INIT_LIST_HEAD(&main_stack); INIT_LIST_HEAD(&sibling_stack); list_add(&main_dentry->tmp_list, &main_stack); while (1) { node = main_dentry->d_inode->children.rb_node; while (1) { if (node->rb_left) { list_add(&rbnode_dentry(node)->tmp_list, &sibling_stack); node = node->rb_left; continue; } if (node->rb_right) { list_add(&rbnode_dentry(node)->tmp_list, &sibling_stack); node = node->rb_right; continue; } list_add(&rbnode_dentry(node)->tmp_list, &sibling_stack); } pop_sibling: next_sibling = sibling_stack.next; if (next_sibling == sibling_stack_bottom) { main_dentry = container_of(main_stack.next, struct dentry, tmp_list); list_del(&main_dentry->tmp_list); sibling_stack_bottom = (void*)main_dentry->parent; if (main_dentry == root) { main_dentry->parent = main_dentry; ret = visitor(dentry, arg); return ret; } else { main_dentry->parent = container_of(main_stack.next, struct dentry, tmp_list); } ret = visitor(main_dentry, arg); if (ret != 0) { list_del(&root->tmp_list); list_for_each_entry(dentry, &main_stack, tmp_list) { dentry->parent = container_of(dentry->tmp_list.next, struct dentry, tmp_list); } root->parent = root; return ret; } goto pop_sibling; } else { list_del(next_sibling); dentry = container_of(next_sibling, struct dentry, tmp_list); list_add(&dentry->tmp_list, &main_stack); dentry->parent = (void*)sibling_stack_bottom; sibling_stack_bottom = sibling_stack.next; main_dentry = dentry; } } #endif } /* * Calculate the full path of @dentry, based on its parent's full path and on * its UTF-8 file name. */ int calculate_dentry_full_path(struct dentry *dentry, void *ignore) { char *full_path; u32 full_path_len; if (dentry_is_root(dentry)) { full_path = MALLOC(2); if (!full_path) goto oom; full_path[0] = '/'; full_path[1] = '\0'; full_path_len = 1; } else { char *parent_full_path; u32 parent_full_path_len; const struct dentry *parent = dentry->parent; if (dentry_is_root(parent)) { parent_full_path = ""; parent_full_path_len = 0; } else { parent_full_path = parent->full_path_utf8; parent_full_path_len = parent->full_path_utf8_len; } full_path_len = parent_full_path_len + 1 + dentry->file_name_utf8_len; full_path = MALLOC(full_path_len + 1); if (!full_path) goto oom; memcpy(full_path, parent_full_path, parent_full_path_len); full_path[parent_full_path_len] = '/'; memcpy(full_path + parent_full_path_len + 1, dentry->file_name_utf8, dentry->file_name_utf8_len); full_path[full_path_len] = '\0'; } FREE(dentry->full_path_utf8); dentry->full_path_utf8 = full_path; dentry->full_path_utf8_len = full_path_len; return 0; oom: ERROR("Out of memory while calculating dentry full path"); return WIMLIB_ERR_NOMEM; } static int increment_subdir_offset(struct dentry *dentry, void *subdir_offset_p) { *(u64*)subdir_offset_p += dentry_correct_total_length(dentry); return 0; } static int call_calculate_subdir_offsets(struct dentry *dentry, void *subdir_offset_p) { calculate_subdir_offsets(dentry, subdir_offset_p); return 0; } /* * Recursively calculates the subdir offsets for a directory tree. * * @dentry: The root of the directory tree. * @subdir_offset_p: The current subdirectory offset; i.e., the subdirectory * offset for @dentry. */ void calculate_subdir_offsets(struct dentry *dentry, u64 *subdir_offset_p) { struct rb_node *node; dentry->subdir_offset = *subdir_offset_p; node = dentry->d_inode->children.rb_node; if (node) { /* Advance the subdir offset by the amount of space the children * of this dentry take up. */ for_dentry_in_rbtree(node, increment_subdir_offset, subdir_offset_p); /* End-of-directory dentry on disk. */ *subdir_offset_p += 8; /* Recursively call calculate_subdir_offsets() on all the * children. */ for_dentry_in_rbtree(node, call_calculate_subdir_offsets, subdir_offset_p); } else { /* On disk, childless directories have a valid subdir_offset * that points to an 8-byte end-of-directory dentry. Regular * files or reparse points have a subdir_offset of 0. */ if (dentry_is_directory(dentry)) *subdir_offset_p += 8; else dentry->subdir_offset = 0; } } static int compare_names(const char *name_1, u16 len_1, const char *name_2, u16 len_2) { int result = strncasecmp(name_1, name_2, min(len_1, len_2)); if (result) { return result; } else { return (int)len_1 - (int)len_2; } } static int dentry_compare_names(const struct dentry *d1, const struct dentry *d2) { return compare_names(d1->file_name_utf8, d1->file_name_utf8_len, d2->file_name_utf8, d2->file_name_utf8_len); } static struct dentry * get_rbtree_child_with_name(const struct rb_node *node, const char *name, size_t name_len) { do { struct dentry *child = rbnode_dentry(node); int result = compare_names(name, name_len, child->file_name_utf8, child->file_name_utf8_len); if (result < 0) node = node->rb_left; else if (result > 0) node = node->rb_right; else return child; } while (node); return NULL; } /* Returns the child of @dentry that has the file name @name. * Returns NULL if no child has the name. */ struct dentry *get_dentry_child_with_name(const struct dentry *dentry, const char *name) { struct rb_node *node = dentry->d_inode->children.rb_node; if (node) return get_rbtree_child_with_name(node, name, strlen(name)); else return NULL; } /* Retrieves the dentry that has the UTF-8 @path relative to the dentry * @cur_dentry. Returns NULL if no dentry having the path is found. */ static struct dentry *get_dentry_relative_path(struct dentry *cur_dentry, const char *path) { if (*path == '\0') return cur_dentry; struct rb_node *node = cur_dentry->d_inode->children.rb_node; if (node) { struct dentry *child; size_t base_len; const char *new_path; new_path = path_next_part(path, &base_len); child = get_rbtree_child_with_name(node, path, base_len); if (child) return get_dentry_relative_path(child, new_path); } return NULL; } /* Returns the dentry corresponding to the UTF-8 @path, or NULL if there is no * such dentry. */ struct dentry *get_dentry(WIMStruct *w, const char *path) { struct dentry *root = wim_root_dentry(w); while (*path == '/') path++; return get_dentry_relative_path(root, path); } struct inode *wim_pathname_to_inode(WIMStruct *w, const char *path) { struct dentry *dentry; dentry = get_dentry(w, path); if (dentry) return dentry->d_inode; else return NULL; } /* Returns the dentry that corresponds to the parent directory of @path, or NULL * if the dentry is not found. */ struct dentry *get_parent_dentry(WIMStruct *w, const char *path) { size_t path_len = strlen(path); char buf[path_len + 1]; memcpy(buf, path, path_len + 1); to_parent_name(buf, path_len); return get_dentry(w, buf); } /* Prints the full path of a dentry. */ int print_dentry_full_path(struct dentry *dentry, void *ignore) { if (dentry->full_path_utf8) puts(dentry->full_path_utf8); return 0; } /* We want to be able to show the names of the file attribute flags that are * set. */ struct file_attr_flag { u32 flag; const char *name; }; struct file_attr_flag file_attr_flags[] = { {FILE_ATTRIBUTE_READONLY, "READONLY"}, {FILE_ATTRIBUTE_HIDDEN, "HIDDEN"}, {FILE_ATTRIBUTE_SYSTEM, "SYSTEM"}, {FILE_ATTRIBUTE_DIRECTORY, "DIRECTORY"}, {FILE_ATTRIBUTE_ARCHIVE, "ARCHIVE"}, {FILE_ATTRIBUTE_DEVICE, "DEVICE"}, {FILE_ATTRIBUTE_NORMAL, "NORMAL"}, {FILE_ATTRIBUTE_TEMPORARY, "TEMPORARY"}, {FILE_ATTRIBUTE_SPARSE_FILE, "SPARSE_FILE"}, {FILE_ATTRIBUTE_REPARSE_POINT, "REPARSE_POINT"}, {FILE_ATTRIBUTE_COMPRESSED, "COMPRESSED"}, {FILE_ATTRIBUTE_OFFLINE, "OFFLINE"}, {FILE_ATTRIBUTE_NOT_CONTENT_INDEXED,"NOT_CONTENT_INDEXED"}, {FILE_ATTRIBUTE_ENCRYPTED, "ENCRYPTED"}, {FILE_ATTRIBUTE_VIRTUAL, "VIRTUAL"}, }; /* Prints a directory entry. @lookup_table is a pointer to the lookup table, if * available. If the dentry is unresolved and the lookup table is NULL, the * lookup table entries will not be printed. Otherwise, they will be. */ int print_dentry(struct dentry *dentry, void *lookup_table) { const u8 *hash; struct lookup_table_entry *lte; const struct inode *inode = dentry->d_inode; char buf[50]; printf("[DENTRY]\n"); printf("Length = %"PRIu64"\n", dentry->length); printf("Attributes = 0x%x\n", inode->attributes); for (size_t i = 0; i < ARRAY_LEN(file_attr_flags); i++) if (file_attr_flags[i].flag & inode->attributes) printf(" FILE_ATTRIBUTE_%s is set\n", file_attr_flags[i].name); printf("Security ID = %d\n", inode->security_id); printf("Subdir offset = %"PRIu64"\n", dentry->subdir_offset); wim_timestamp_to_str(inode->creation_time, buf, sizeof(buf)); printf("Creation Time = %s\n", buf); wim_timestamp_to_str(inode->last_access_time, buf, sizeof(buf)); printf("Last Access Time = %s\n", buf); wim_timestamp_to_str(inode->last_write_time, buf, sizeof(buf)); printf("Last Write Time = %s\n", buf); printf("Reparse Tag = 0x%"PRIx32"\n", inode->reparse_tag); printf("Hard Link Group = 0x%"PRIx64"\n", inode->ino); printf("Hard Link Group Size = %"PRIu32"\n", inode->link_count); printf("Number of Alternate Data Streams = %hu\n", inode->num_ads); printf("Filename (UTF-8) = \"%s\"\n", dentry->file_name_utf8); /*printf("Filename (UTF-8) Length = %hu\n", dentry->file_name_utf8_len);*/ printf("Short Name (UTF-16LE) = \""); print_string(dentry->short_name, dentry->short_name_len); puts("\""); /*printf("Short Name Length = %hu\n", dentry->short_name_len);*/ printf("Full Path (UTF-8) = \"%s\"\n", dentry->full_path_utf8); lte = inode_stream_lte(dentry->d_inode, 0, lookup_table); if (lte) { print_lookup_table_entry(lte); } else { hash = inode_stream_hash(inode, 0); if (hash) { printf("Hash = 0x"); print_hash(hash); putchar('\n'); putchar('\n'); } } for (u16 i = 0; i < inode->num_ads; i++) { printf("[Alternate Stream Entry %u]\n", i); printf("Name = \"%s\"\n", inode->ads_entries[i].stream_name_utf8); printf("Name Length (UTF-16) = %u\n", inode->ads_entries[i].stream_name_len); hash = inode_stream_hash(inode, i + 1); if (hash) { printf("Hash = 0x"); print_hash(hash); putchar('\n'); } print_lookup_table_entry(inode_stream_lte(inode, i + 1, lookup_table)); } return 0; } /* Initializations done on every `struct dentry'. */ static void dentry_common_init(struct dentry *dentry) { memset(dentry, 0, sizeof(struct dentry)); dentry->refcnt = 1; } static struct inode *new_timeless_inode() { struct inode *inode = CALLOC(1, sizeof(struct inode)); if (inode) { inode->security_id = -1; inode->link_count = 1; #ifdef WITH_FUSE inode->next_stream_id = 1; if (pthread_mutex_init(&inode->i_mutex, NULL) != 0) { ERROR_WITH_ERRNO("Error initializing mutex"); FREE(inode); return NULL; } #endif INIT_LIST_HEAD(&inode->dentry_list); } return inode; } static struct inode *new_inode() { struct inode *inode = new_timeless_inode(); if (inode) { u64 now = get_wim_timestamp(); inode->creation_time = now; inode->last_access_time = now; inode->last_write_time = now; } return inode; } /* * Creates an unlinked directory entry. * * @name: The UTF-8 filename of the new dentry. * * Returns a pointer to the new dentry, or NULL if out of memory. */ #ifndef WITH_FUSE static #endif struct dentry *new_dentry(const char *name) { struct dentry *dentry; dentry = MALLOC(sizeof(struct dentry)); if (!dentry) goto err; dentry_common_init(dentry); if (change_dentry_name(dentry, name) != 0) goto err; dentry->parent = dentry; return dentry; err: FREE(dentry); ERROR_WITH_ERRNO("Failed to create new dentry with name \"%s\"", name); return NULL; } static struct dentry *__new_dentry_with_inode(const char *name, bool timeless) { struct dentry *dentry; dentry = new_dentry(name); if (dentry) { if (timeless) dentry->d_inode = new_timeless_inode(); else dentry->d_inode = new_inode(); if (dentry->d_inode) { inode_add_dentry(dentry, dentry->d_inode); } else { free_dentry(dentry); dentry = NULL; } } return dentry; } struct dentry *new_dentry_with_timeless_inode(const char *name) { return __new_dentry_with_inode(name, true); } struct dentry *new_dentry_with_inode(const char *name) { return __new_dentry_with_inode(name, false); } static int init_ads_entry(struct ads_entry *ads_entry, const char *name) { int ret = 0; memset(ads_entry, 0, sizeof(*ads_entry)); if (name && *name) ret = change_ads_name(ads_entry, name); return ret; } static void destroy_ads_entry(struct ads_entry *ads_entry) { FREE(ads_entry->stream_name); FREE(ads_entry->stream_name_utf8); } /* Frees an inode. */ void free_inode(struct inode *inode) { if (inode) { if (inode->ads_entries) { for (u16 i = 0; i < inode->num_ads; i++) destroy_ads_entry(&inode->ads_entries[i]); FREE(inode->ads_entries); } #ifdef WITH_FUSE wimlib_assert(inode->num_opened_fds == 0); FREE(inode->fds); pthread_mutex_destroy(&inode->i_mutex); if (inode->hlist.pprev) hlist_safe_del(&inode->hlist); #endif FREE(inode->extracted_file); FREE(inode); } } /* Decrements link count on an inode and frees it if the link count reaches 0. * */ static void put_inode(struct inode *inode) { wimlib_assert(inode->link_count != 0); if (--inode->link_count == 0) { #ifdef WITH_FUSE if (inode->num_opened_fds == 0) #endif { free_inode(inode); } } } /* Frees a WIM dentry. * * The inode is freed only if its link count is decremented to 0. */ void free_dentry(struct dentry *dentry) { FREE(dentry->file_name); FREE(dentry->file_name_utf8); FREE(dentry->short_name); FREE(dentry->full_path_utf8); if (dentry->d_inode) put_inode(dentry->d_inode); FREE(dentry); } void put_dentry(struct dentry *dentry) { wimlib_assert(dentry->refcnt != 0); if (--dentry->refcnt == 0) free_dentry(dentry); } /* * This function is passed as an argument to for_dentry_in_tree_depth() in order * to free a directory tree. __args is a pointer to a `struct free_dentry_args'. */ static int do_free_dentry(struct dentry *dentry, void *__lookup_table) { struct lookup_table *lookup_table = __lookup_table; unsigned i; if (lookup_table) { struct lookup_table_entry *lte; struct inode *inode = dentry->d_inode; wimlib_assert(inode->link_count != 0); for (i = 0; i <= inode->num_ads; i++) { lte = inode_stream_lte(inode, i, lookup_table); if (lte) lte_decrement_refcnt(lte, lookup_table); } } put_dentry(dentry); return 0; } /* * Unlinks and frees a dentry tree. * * @root: The root of the tree. * @lookup_table: The lookup table for dentries. If non-NULL, the * reference counts in the lookup table for the lookup * table entries corresponding to the dentries will be * decremented. */ void free_dentry_tree(struct dentry *root, struct lookup_table *lookup_table) { if (root) for_dentry_in_tree_depth(root, do_free_dentry, lookup_table); } int increment_dentry_refcnt(struct dentry *dentry, void *ignore) { dentry->refcnt++; return 0; } /* * Links a dentry into the directory tree. * * @dentry: The dentry to link. * @parent: The dentry that will be the parent of @dentry. */ bool dentry_add_child(struct dentry * restrict parent, struct dentry * restrict child) { wimlib_assert(dentry_is_directory(parent)); struct rb_root *root = &parent->d_inode->children; struct rb_node **new = &(root->rb_node); struct rb_node *rb_parent = NULL; while (*new) { struct dentry *this = rbnode_dentry(*new); int result = dentry_compare_names(child, this); rb_parent = *new; if (result < 0) new = &((*new)->rb_left); else if (result > 0) new = &((*new)->rb_right); else return false; } child->parent = parent; rb_link_node(&child->rb_node, rb_parent, new); rb_insert_color(&child->rb_node, root); return true; } #ifdef WITH_FUSE /* * Unlink a dentry from the directory tree. * * Note: This merely removes it from the in-memory tree structure. */ void unlink_dentry(struct dentry *dentry) { struct dentry *parent = dentry->parent; if (parent == dentry) return; rb_erase(&dentry->rb_node, &parent->d_inode->children); } #endif #ifdef WITH_FUSE /* Returns the alternate data stream entry belonging to @inode that has the * stream name @stream_name. */ struct ads_entry *inode_get_ads_entry(struct inode *inode, const char *stream_name, u16 *idx_ret) { size_t stream_name_len; if (!stream_name) return NULL; if (inode->num_ads) { u16 i = 0; stream_name_len = strlen(stream_name); do { if (ads_entry_has_name(&inode->ads_entries[i], stream_name, stream_name_len)) { if (idx_ret) *idx_ret = i; return &inode->ads_entries[i]; } } while (++i != inode->num_ads); } return NULL; } #endif #if defined(WITH_FUSE) || defined(WITH_NTFS_3G) /* * Add an alternate stream entry to an inode and return a pointer to it, or NULL * if memory could not be allocated. */ struct ads_entry *inode_add_ads(struct inode *inode, const char *stream_name) { u16 num_ads; struct ads_entry *ads_entries; struct ads_entry *new_entry; DEBUG("Add alternate data stream \"%s\"", stream_name); if (inode->num_ads >= 0xfffe) { ERROR("Too many alternate data streams in one inode!"); return NULL; } num_ads = inode->num_ads + 1; ads_entries = REALLOC(inode->ads_entries, num_ads * sizeof(inode->ads_entries[0])); if (!ads_entries) { ERROR("Failed to allocate memory for new alternate data stream"); return NULL; } inode->ads_entries = ads_entries; new_entry = &inode->ads_entries[num_ads - 1]; if (init_ads_entry(new_entry, stream_name) != 0) return NULL; #ifdef WITH_FUSE new_entry->stream_id = inode->next_stream_id++; #endif inode->num_ads = num_ads; return new_entry; } #endif #ifdef WITH_FUSE /* Remove an alternate data stream from the inode */ void inode_remove_ads(struct inode *inode, u16 idx, struct lookup_table *lookup_table) { struct ads_entry *ads_entry; struct lookup_table_entry *lte; wimlib_assert(idx < inode->num_ads); wimlib_assert(inode->resolved); ads_entry = &inode->ads_entries[idx]; DEBUG("Remove alternate data stream \"%s\"", ads_entry->stream_name_utf8); lte = ads_entry->lte; if (lte) lte_decrement_refcnt(lte, lookup_table); destroy_ads_entry(ads_entry); memcpy(&inode->ads_entries[idx], &inode->ads_entries[idx + 1], (inode->num_ads - idx - 1) * sizeof(inode->ads_entries[0])); inode->num_ads--; } #endif /* * Reads the alternate data stream entries for a dentry. * * @p: Pointer to buffer that starts with the first alternate stream entry. * * @inode: Inode to load the alternate data streams into. * @inode->num_ads must have been set to the number of * alternate data streams that are expected. * * @remaining_size: Number of bytes of data remaining in the buffer pointed * to by @p. * * The format of the on-disk alternate stream entries is as follows: * * struct ads_entry_on_disk { * u64 length; // Length of the entry, in bytes. This includes * all fields (including the stream name and * null terminator if present, AND the padding!). * u64 reserved; // Seems to be unused * u8 hash[20]; // SHA1 message digest of the uncompressed stream * u16 stream_name_len; // Length of the stream name, in bytes * char stream_name[]; // Stream name in UTF-16LE, @stream_name_len bytes long, * not including null terminator * u16 zero; // UTF-16 null terminator for the stream name, NOT * included in @stream_name_len. Based on what * I've observed from filenames in dentries, * this field should not exist when * (@stream_name_len == 0), but you can't * actually tell because of the padding anyway * (provided that the padding is zeroed, which * it always seems to be). * char padding[]; // Padding to make the size a multiple of 8 bytes. * }; * * In addition, the entries are 8-byte aligned. * * Return 0 on success or nonzero on failure. On success, inode->ads_entries * is set to an array of `struct ads_entry's of length inode->num_ads. On * failure, @inode is not modified. */ static int read_ads_entries(const u8 *p, struct inode *inode, u64 remaining_size) { u16 num_ads; struct ads_entry *ads_entries; int ret; num_ads = inode->num_ads; ads_entries = CALLOC(num_ads, sizeof(inode->ads_entries[0])); if (!ads_entries) { ERROR("Could not allocate memory for %"PRIu16" " "alternate data stream entries", num_ads); return WIMLIB_ERR_NOMEM; } for (u16 i = 0; i < num_ads; i++) { struct ads_entry *cur_entry; u64 length; u64 length_no_padding; u64 total_length; size_t utf8_len; const u8 *p_save = p; cur_entry = &ads_entries[i]; #ifdef WITH_FUSE ads_entries[i].stream_id = i + 1; #endif /* Read the base stream entry, excluding the stream name. */ if (remaining_size < WIM_ADS_ENTRY_DISK_SIZE) { ERROR("Stream entries go past end of metadata resource"); ERROR("(remaining_size = %"PRIu64")", remaining_size); ret = WIMLIB_ERR_INVALID_DENTRY; goto out_free_ads_entries; } p = get_u64(p, &length); p += 8; /* Skip the reserved field */ p = get_bytes(p, SHA1_HASH_SIZE, (u8*)cur_entry->hash); p = get_u16(p, &cur_entry->stream_name_len); cur_entry->stream_name = NULL; cur_entry->stream_name_utf8 = NULL; /* Length including neither the null terminator nor the padding * */ length_no_padding = WIM_ADS_ENTRY_DISK_SIZE + cur_entry->stream_name_len; /* Length including the null terminator and the padding */ total_length = ((length_no_padding + 2) + 7) & ~7; wimlib_assert(total_length == ads_entry_total_length(cur_entry)); if (remaining_size < length_no_padding) { ERROR("Stream entries go past end of metadata resource"); ERROR("(remaining_size = %"PRIu64" bytes, " "length_no_padding = %"PRIu64" bytes)", remaining_size, length_no_padding); ret = WIMLIB_ERR_INVALID_DENTRY; goto out_free_ads_entries; } /* The @length field in the on-disk ADS entry is expected to be * equal to @total_length, which includes all of the entry and * the padding that follows it to align the next ADS entry to an * 8-byte boundary. However, to be safe, we'll accept the * length field as long as it's not less than the un-padded * total length and not more than the padded total length. */ if (length < length_no_padding || length > total_length) { ERROR("Stream entry has unexpected length " "field (length field = %"PRIu64", " "unpadded total length = %"PRIu64", " "padded total length = %"PRIu64")", length, length_no_padding, total_length); ret = WIMLIB_ERR_INVALID_DENTRY; goto out_free_ads_entries; } if (cur_entry->stream_name_len) { cur_entry->stream_name = MALLOC(cur_entry->stream_name_len); if (!cur_entry->stream_name) { ret = WIMLIB_ERR_NOMEM; goto out_free_ads_entries; } get_bytes(p, cur_entry->stream_name_len, (u8*)cur_entry->stream_name); ret = utf16_to_utf8(cur_entry->stream_name, cur_entry->stream_name_len, &cur_entry->stream_name_utf8, &utf8_len); if (ret != 0) goto out_free_ads_entries; cur_entry->stream_name_utf8_len = utf8_len; } /* It's expected that the size of every ADS entry is a multiple * of 8. However, to be safe, I'm allowing the possibility of * an ADS entry at the very end of the metadata resource ending * un-aligned. So although we still need to increment the input * pointer by @total_length to reach the next ADS entry, it's * possible that less than @total_length is actually remaining * in the metadata resource. We should set the remaining size to * 0 bytes if this happens. */ p = p_save + total_length; if (remaining_size < total_length) remaining_size = 0; else remaining_size -= total_length; } inode->ads_entries = ads_entries; #ifdef WITH_FUSE inode->next_stream_id = inode->num_ads + 1; #endif return 0; out_free_ads_entries: for (u16 i = 0; i < num_ads; i++) destroy_ads_entry(&ads_entries[i]); FREE(ads_entries); return ret; } /* * Reads a directory entry, including all alternate data stream entries that * follow it, from the WIM image's metadata resource. * * @metadata_resource: Buffer containing the uncompressed metadata resource. * @metadata_resource_len: Length of the metadata resource. * @offset: Offset of this directory entry in the metadata resource. * @dentry: A `struct dentry' that will be filled in by this function. * * Return 0 on success or nonzero on failure. On failure, @dentry will have * been modified, but it will not be left with pointers to any allocated * buffers. On success, the dentry->length field must be examined. If zero, * this was a special "end of directory" dentry and not a real dentry. If * nonzero, this was a real dentry. */ int read_dentry(const u8 metadata_resource[], u64 metadata_resource_len, u64 offset, struct dentry *dentry) { const u8 *p; u64 calculated_size; char *file_name = NULL; char *file_name_utf8 = NULL; char *short_name = NULL; u16 short_name_len; u16 file_name_len; size_t file_name_utf8_len = 0; int ret; struct inode *inode = NULL; dentry_common_init(dentry); /*Make sure the dentry really fits into the metadata resource.*/ if (offset + 8 > metadata_resource_len || offset + 8 < offset) { ERROR("Directory entry starting at %"PRIu64" ends past the " "end of the metadata resource (size %"PRIu64")", offset, metadata_resource_len); return WIMLIB_ERR_INVALID_DENTRY; } /* Before reading the whole dentry, we need to read just the length. * This is because a dentry of length 8 (that is, just the length field) * terminates the list of sibling directory entries. */ p = get_u64(&metadata_resource[offset], &dentry->length); /* A zero length field (really a length of 8, since that's how big the * directory entry is...) indicates that this is the end of directory * dentry. We do not read it into memory as an actual dentry, so just * return successfully in that case. */ if (dentry->length == 0) return 0; /* If the dentry does not overflow the metadata resource buffer and is * not too short, read the rest of it (excluding the alternate data * streams, but including the file name and short name variable-length * fields) into memory. */ if (offset + dentry->length >= metadata_resource_len || offset + dentry->length < offset) { ERROR("Directory entry at offset %"PRIu64" and with size " "%"PRIu64" ends past the end of the metadata resource " "(size %"PRIu64")", offset, dentry->length, metadata_resource_len); return WIMLIB_ERR_INVALID_DENTRY; } if (dentry->length < WIM_DENTRY_DISK_SIZE) { ERROR("Directory entry has invalid length of %"PRIu64" bytes", dentry->length); return WIMLIB_ERR_INVALID_DENTRY; } inode = new_timeless_inode(); if (!inode) return WIMLIB_ERR_NOMEM; p = get_u32(p, &inode->attributes); p = get_u32(p, (u32*)&inode->security_id); p = get_u64(p, &dentry->subdir_offset); /* 2 unused fields */ p += 2 * sizeof(u64); /*p = get_u64(p, &dentry->unused1);*/ /*p = get_u64(p, &dentry->unused2);*/ p = get_u64(p, &inode->creation_time); p = get_u64(p, &inode->last_access_time); p = get_u64(p, &inode->last_write_time); p = get_bytes(p, SHA1_HASH_SIZE, inode->hash); /* * I don't know what's going on here. It seems like M$ screwed up the * reparse points, then put the fields in the same place and didn't * document it. The WIM_HDR_FLAG_RP_FIX flag in the WIM header might * have something to do with this, but it's not documented. */ if (inode->attributes & FILE_ATTRIBUTE_REPARSE_POINT) { /* ??? */ p += 4; p = get_u32(p, &inode->reparse_tag); p += 4; } else { p = get_u32(p, &inode->reparse_tag); p = get_u64(p, &inode->ino); } /* By the way, the reparse_reserved field does not actually exist (at * least when the file is not a reparse point) */ p = get_u16(p, &inode->num_ads); p = get_u16(p, &short_name_len); p = get_u16(p, &file_name_len); /* We now know the length of the file name and short name. Make sure * the length of the dentry is large enough to actually hold them. * * The calculated length here is unaligned to allow for the possibility * that the dentry->length names an unaligned length, although this * would be unexpected. */ calculated_size = __dentry_correct_length_unaligned(file_name_len, short_name_len); if (dentry->length < calculated_size) { ERROR("Unexpected end of directory entry! (Expected " "at least %"PRIu64" bytes, got %"PRIu64" bytes. " "short_name_len = %hu, file_name_len = %hu)", calculated_size, dentry->length, short_name_len, file_name_len); ret = WIMLIB_ERR_INVALID_DENTRY; goto out_free_inode; } /* Read the filename if present. Note: if the filename is empty, there * is no null terminator following it. */ if (file_name_len) { file_name = MALLOC(file_name_len); if (!file_name) { ERROR("Failed to allocate %hu bytes for dentry file name", file_name_len); ret = WIMLIB_ERR_NOMEM; goto out_free_inode; } p = get_bytes(p, file_name_len, file_name); /* Convert filename to UTF-8. */ ret = utf16_to_utf8(file_name, file_name_len, &file_name_utf8, &file_name_utf8_len); if (ret != 0) goto out_free_file_name; if (*(u16*)p) WARNING("Expected two zero bytes following the file name " "`%s', but found non-zero bytes", file_name_utf8); p += 2; } /* Align the calculated size */ calculated_size = (calculated_size + 7) & ~7; if (dentry->length > calculated_size) { /* Weird; the dentry says it's longer than it should be. Note * that the length field does NOT include the size of the * alternate stream entries. */ /* Strangely, some directory entries inexplicably have a little * over 70 bytes of extra data. The exact amount of data seems * to be 72 bytes, but it is aligned on the next 8-byte * boundary. It does NOT seem to be alternate data stream * entries. Here's an example of the aligned data: * * 01000000 40000000 6c786bba c58ede11 b0bb0026 1870892a b6adb76f * e63a3e46 8fca8653 0d2effa1 6c786bba c58ede11 b0bb0026 1870892a * 00000000 00000000 00000000 00000000 * * Here's one interpretation of how the data is laid out. * * struct unknown { * u32 field1; (always 0x00000001) * u32 field2; (always 0x40000000) * u8 data[48]; (???) * u64 reserved1; (always 0) * u64 reserved2; (always 0) * };*/ DEBUG("Dentry for file or directory `%s' has %zu extra " "bytes of data", file_name_utf8, dentry->length - calculated_size); } /* Read the short filename if present. Note: if there is no short * filename, there is no null terminator following it. */ if (short_name_len) { short_name = MALLOC(short_name_len); if (!short_name) { ERROR("Failed to allocate %hu bytes for short filename", short_name_len); ret = WIMLIB_ERR_NOMEM; goto out_free_file_name_utf8; } p = get_bytes(p, short_name_len, short_name); if (*(u16*)p) WARNING("Expected two zero bytes following the short name of " "`%s', but found non-zero bytes", file_name_utf8); p += 2; } /* * Read the alternate data streams, if present. dentry->num_ads tells * us how many they are, and they will directly follow the dentry * on-disk. * * Note that each alternate data stream entry begins on an 8-byte * aligned boundary, and the alternate data stream entries are NOT * included in the dentry->length field for some reason. */ if (inode->num_ads != 0) { /* Trying different lengths is just a hack to make sure we have * a chance of reading the ADS entries correctly despite the * poor documentation. */ if (calculated_size != dentry->length) { WARNING("Trying calculated dentry length (%"PRIu64") " "instead of dentry->length field (%"PRIu64") " "to read ADS entries", calculated_size, dentry->length); } u64 lengths_to_try[3] = {calculated_size, (dentry->length + 7) & ~7, dentry->length}; ret = WIMLIB_ERR_INVALID_DENTRY; for (size_t i = 0; i < ARRAY_LEN(lengths_to_try); i++) { if (lengths_to_try[i] > metadata_resource_len - offset) continue; ret = read_ads_entries(&metadata_resource[offset + lengths_to_try[i]], inode, metadata_resource_len - offset - lengths_to_try[i]); if (ret == 0) goto out; } ERROR("Failed to read alternate data stream " "entries of `%s'", dentry->file_name_utf8); goto out_free_short_name; } out: /* We've read all the data for this dentry. Set the names and their * lengths, and we've done. */ dentry->d_inode = inode; dentry->file_name = file_name; dentry->file_name_utf8 = file_name_utf8; dentry->short_name = short_name; dentry->file_name_len = file_name_len; dentry->file_name_utf8_len = file_name_utf8_len; dentry->short_name_len = short_name_len; return 0; out_free_short_name: FREE(short_name); out_free_file_name_utf8: FREE(file_name_utf8); out_free_file_name: FREE(file_name); out_free_inode: free_inode(inode); return ret; } /* Reads the children of a dentry, and all their children, ..., etc. from the * metadata resource and into the dentry tree. * * @metadata_resource: An array that contains the uncompressed metadata * resource for the WIM file. * * @metadata_resource_len: The length of the uncompressed metadata resource, in * bytes. * * @dentry: A pointer to a `struct dentry' that is the root of the directory * tree and has already been read from the metadata resource. It * does not need to be the real root because this procedure is * called recursively. * * @return: Zero on success, nonzero on failure. */ int read_dentry_tree(const u8 metadata_resource[], u64 metadata_resource_len, struct dentry *dentry) { u64 cur_offset = dentry->subdir_offset; struct dentry *child; struct dentry cur_child; int ret; /* * If @dentry has no child dentries, nothing more needs to be done for * this branch. This is the case for regular files, symbolic links, and * *possibly* empty directories (although an empty directory may also * have one child dentry that is the special end-of-directory dentry) */ if (cur_offset == 0) return 0; /* Find and read all the children of @dentry. */ while (1) { /* Read next child of @dentry into @cur_child. */ ret = read_dentry(metadata_resource, metadata_resource_len, cur_offset, &cur_child); if (ret != 0) break; /* Check for end of directory. */ if (cur_child.length == 0) break; /* Not end of directory. Allocate this child permanently and * link it to the parent and previous child. */ child = MALLOC(sizeof(struct dentry)); if (!child) { ERROR("Failed to allocate %zu bytes for new dentry", sizeof(struct dentry)); ret = WIMLIB_ERR_NOMEM; break; } memcpy(child, &cur_child, sizeof(struct dentry)); dentry_add_child(dentry, child); inode_add_dentry(child, child->d_inode); /* If there are children of this child, call this procedure * recursively. */ if (child->subdir_offset != 0) { ret = read_dentry_tree(metadata_resource, metadata_resource_len, child); if (ret != 0) break; } /* Advance to the offset of the next child. Note: We need to * advance by the TOTAL length of the dentry, not by the length * child->length, which although it does take into account the * padding, it DOES NOT take into account alternate stream * entries. */ cur_offset += dentry_total_length(child); } return ret; } /* * Writes a WIM dentry to an output buffer. * * @dentry: The dentry structure. * @p: The memory location to write the data to. * @return: Pointer to the byte after the last byte we wrote as part of the * dentry. */ static u8 *write_dentry(const struct dentry *dentry, u8 *p) { u8 *orig_p = p; const u8 *hash; const struct inode *inode = dentry->d_inode; /* We calculate the correct length of the dentry ourselves because the * dentry->length field may been set to an unexpected value from when we * read the dentry in (for example, there may have been unknown data * appended to the end of the dentry...) */ u64 length = dentry_correct_length(dentry); p = put_u64(p, length); p = put_u32(p, inode->attributes); p = put_u32(p, inode->security_id); p = put_u64(p, dentry->subdir_offset); p = put_u64(p, 0); /* unused1 */ p = put_u64(p, 0); /* unused2 */ p = put_u64(p, inode->creation_time); p = put_u64(p, inode->last_access_time); p = put_u64(p, inode->last_write_time); hash = inode_stream_hash(inode, 0); p = put_bytes(p, SHA1_HASH_SIZE, hash); if (inode->attributes & FILE_ATTRIBUTE_REPARSE_POINT) { p = put_zeroes(p, 4); p = put_u32(p, inode->reparse_tag); p = put_zeroes(p, 4); } else { u64 link_group_id; p = put_u32(p, 0); if (inode->link_count == 1) link_group_id = 0; else link_group_id = inode->ino; p = put_u64(p, link_group_id); } p = put_u16(p, inode->num_ads); p = put_u16(p, dentry->short_name_len); p = put_u16(p, dentry->file_name_len); if (dentry->file_name_len) { p = put_bytes(p, dentry->file_name_len, (u8*)dentry->file_name); p = put_u16(p, 0); /* filename padding, 2 bytes. */ } if (dentry->short_name) { p = put_bytes(p, dentry->short_name_len, (u8*)dentry->short_name); p = put_u16(p, 0); /* short name padding, 2 bytes */ } /* Align to 8-byte boundary */ wimlib_assert(length >= (p - orig_p) && length - (p - orig_p) <= 7); p = put_zeroes(p, length - (p - orig_p)); /* Write the alternate data streams, if there are any. Please see * read_ads_entries() for comments about the format of the on-disk * alternate data stream entries. */ for (u16 i = 0; i < inode->num_ads; i++) { p = put_u64(p, ads_entry_total_length(&inode->ads_entries[i])); p = put_u64(p, 0); /* Unused */ hash = inode_stream_hash(inode, i + 1); p = put_bytes(p, SHA1_HASH_SIZE, hash); p = put_u16(p, inode->ads_entries[i].stream_name_len); if (inode->ads_entries[i].stream_name_len) { p = put_bytes(p, inode->ads_entries[i].stream_name_len, (u8*)inode->ads_entries[i].stream_name); p = put_u16(p, 0); } p = put_zeroes(p, (8 - (p - orig_p) % 8) % 8); } wimlib_assert(p - orig_p == __dentry_total_length(dentry, length)); return p; } static int write_dentry_cb(struct dentry *dentry, void *_p) { u8 **p = _p; *p = write_dentry(dentry, *p); return 0; } static u8 *write_dentry_tree_recursive(const struct dentry *parent, u8 *p); static int write_dentry_tree_recursive_cb(struct dentry *dentry, void *_p) { u8 **p = _p; *p = write_dentry_tree_recursive(dentry, *p); return 0; } /* Recursive function that writes a dentry tree rooted at @parent, not including * @parent itself, which has already been written. */ static u8 *write_dentry_tree_recursive(const struct dentry *parent, u8 *p) { /* Nothing to do if this dentry has no children. */ if (parent->subdir_offset == 0) return p; /* Write child dentries and end-of-directory entry. * * Note: we need to write all of this dentry's children before * recursively writing the directory trees rooted at each of the child * dentries, since the on-disk dentries for a dentry's children are * always located at consecutive positions in the metadata resource! */ for_dentry_in_rbtree(parent->d_inode->children.rb_node, write_dentry_cb, &p); /* write end of directory entry */ p = put_u64(p, 0); /* Recurse on children. */ for_dentry_in_rbtree(parent->d_inode->children.rb_node, write_dentry_tree_recursive_cb, &p); return p; } /* Writes a directory tree to the metadata resource. * * @root: Root of the dentry tree. * @p: Pointer to a buffer with enough space for the dentry tree. * * Returns pointer to the byte after the last byte we wrote. */ u8 *write_dentry_tree(const struct dentry *root, u8 *p) { DEBUG("Writing dentry tree."); wimlib_assert(dentry_is_root(root)); /* If we're the root dentry, we have no parent that already * wrote us, so we need to write ourselves. */ p = write_dentry(root, p); /* Write end of directory entry after the root dentry just to be safe; * however the root dentry obviously cannot have any siblings. */ p = put_u64(p, 0); /* Recursively write the rest of the dentry tree. */ return write_dentry_tree_recursive(root, p); }