+++ /dev/null
-/*
- * hardlink.c
- *
- * Code to deal with hard links in WIMs.
- */
-
-/*
- * Copyright (C) 2012, 2013 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/.
- */
-
-#ifdef HAVE_CONFIG_H
-# include "config.h"
-#endif
-
-#include "wimlib/capture.h"
-#include "wimlib/dentry.h"
-#include "wimlib/error.h"
-#include "wimlib/lookup_table.h"
-
-/* NULL NULL
- * ^ ^
- * dentry | |
- * / \ ----------- -----------
- * | dentry<---| struct | | struct |---> dentry
- * \ / | wim_inode| | wim_inode|
- * dentry ------------ ------------
- * ^ ^
- * | |
- * | | dentry
- * ----------- ----------- / \
- * dentry<---| struct | | struct |---> dentry dentry
- * / | wim_inode| | wim_inode| \ /
- * dentry ------------ ------------ dentry
- * ^ ^
- * | |
- * -----------------
- * wim_inode_table->array | idx 0 | idx 1 |
- * -----------------
- */
-
-
-int
-init_inode_table(struct wim_inode_table *table, size_t capacity)
-{
- table->array = CALLOC(capacity, sizeof(table->array[0]));
- if (!table->array) {
- ERROR("Cannot initalize inode table: out of memory");
- return WIMLIB_ERR_NOMEM;
- }
- table->num_entries = 0;
- table->capacity = capacity;
- INIT_LIST_HEAD(&table->extra_inodes);
- return 0;
-}
-
-static inline size_t
-inode_link_count(const struct wim_inode *inode)
-{
- const struct list_head *cur;
- size_t size = 0;
- list_for_each(cur, &inode->i_dentry)
- size++;
- return size;
-}
-
-/* Insert a dentry into the inode table based on the inode number of the
- * attached inode (which came from the hard link group ID field of the on-disk
- * WIM dentry) */
-static int
-inode_table_insert(struct wim_dentry *dentry, void *_table)
-{
- struct wim_inode_table *table = _table;
- struct wim_inode *d_inode = dentry->d_inode;
-
- if (d_inode->i_ino == 0) {
- /* A dentry with a hard link group ID of 0 indicates that it's
- * in a hard link group by itself. Add it to the list of extra
- * inodes rather than inserting it into the hash lists. */
- list_add_tail(&d_inode->i_list, &table->extra_inodes);
- } else {
- size_t pos;
- struct wim_inode *inode;
- struct hlist_node *cur;
-
- /* Try adding this dentry to an existing inode */
- pos = d_inode->i_ino % table->capacity;
- hlist_for_each_entry(inode, cur, &table->array[pos], i_hlist) {
- if (inode->i_ino == d_inode->i_ino) {
- if (unlikely((inode->i_attributes & FILE_ATTRIBUTE_DIRECTORY) ||
- (d_inode->i_attributes & FILE_ATTRIBUTE_DIRECTORY)))
- {
- ERROR("Unsupported directory hard link "
- "\"%"TS"\" <=> \"%"TS"\"",
- dentry_full_path(dentry),
- dentry_full_path(inode_first_dentry(inode)));
- return WIMLIB_ERR_INVALID_METADATA_RESOURCE;
- }
- inode_add_dentry(dentry, inode);
- return 0;
- }
- }
-
- /* No inode in the table has the same number as this one, so add
- * it to the table. */
- hlist_add_head(&d_inode->i_hlist, &table->array[pos]);
-
- /* XXX Make the table grow when too many entries have been
- * inserted. */
- table->num_entries++;
- }
- return 0;
-}
-
-static struct wim_inode *
-inode_table_get_inode(struct wim_inode_table *table, u64 ino, u64 devno)
-{
- u64 hash = hash_u64(hash_u64(ino) + hash_u64(devno));
- size_t pos = hash % table->capacity;
- struct wim_inode *inode;
- struct hlist_node *cur;
-
- hlist_for_each_entry(inode, cur, &table->array[pos], i_hlist) {
- if (inode->i_ino == ino && inode->i_devno == devno) {
- DEBUG("Using existing inode {devno=%"PRIu64", ino=%"PRIu64"}",
- devno, ino);
- inode->i_nlink++;
- return inode;
- }
- }
- inode = new_timeless_inode();
- if (inode) {
- inode->i_ino = ino;
- inode->i_devno = devno;
- hlist_add_head(&inode->i_hlist, &table->array[pos]);
- table->num_entries++;
- }
- return inode;
-}
-
-void
-inode_ref_streams(struct wim_inode *inode)
-{
- for (unsigned i = 0; i <= inode->i_num_ads; i++) {
- struct wim_lookup_table_entry *lte;
- lte = inode_stream_lte_resolved(inode, i);
- if (lte)
- lte->refcnt++;
- }
-}
-
-/* Given a directory entry with the name @name for the file with the inode
- * number @ino and device number @devno, create a new WIM dentry with an
- * associated inode, where the inode is shared if an inode with the same @ino
- * and @devno has already been created. On success, the new WIM dentry is
- * written to *dentry_ret, and its inode has i_nlink > 1 if a previously
- * existing inode was used.
- */
-int
-inode_table_new_dentry(struct wim_inode_table *table, const tchar *name,
- u64 ino, u64 devno, bool noshare,
- struct wim_dentry **dentry_ret)
-{
- struct wim_dentry *dentry;
- struct wim_inode *inode;
- int ret;
-
- if (noshare) {
- /* File that cannot be hardlinked--- Return a new inode with its
- * inode and device numbers left at 0. */
- ret = new_dentry_with_timeless_inode(name, &dentry);
- if (ret)
- return ret;
- list_add_tail(&dentry->d_inode->i_list, &table->extra_inodes);
- } else {
- /* File that can be hardlinked--- search the table for an
- * existing inode matching the inode number and device;
- * otherwise create a new inode. */
- ret = new_dentry(name, &dentry);
- if (ret)
- return ret;
- inode = inode_table_get_inode(table, ino, devno);
- if (!inode) {
- free_dentry(dentry);
- return WIMLIB_ERR_NOMEM;
- }
- /* If using an existing inode, we need to gain a reference to
- * each of its streams. */
- if (inode->i_nlink > 1)
- inode_ref_streams(inode);
- dentry->d_inode = inode;
- inode_add_dentry(dentry, inode);
- }
- *dentry_ret = dentry;
- return 0;
-}
-
-static inline void
-print_inode_dentries(const struct wim_inode *inode)
-{
- struct wim_dentry *dentry;
- inode_for_each_dentry(dentry, inode)
- tfprintf(stderr, T("%"TS"\n"), dentry_full_path(dentry));
-}
-
-static void
-inconsistent_inode(const struct wim_inode *inode)
-{
- if (wimlib_print_errors) {
- ERROR("An inconsistent hard link group that cannot be corrected has "
- "been detected");
- ERROR("The dentries are located at the following paths:");
- print_inode_dentries(inode);
- }
-}
-
-static bool
-ref_inodes_consistent(const struct wim_inode * restrict ref_inode_1,
- const struct wim_inode * restrict ref_inode_2)
-{
- wimlib_assert(ref_inode_1 != ref_inode_2);
-
- if (ref_inode_1->i_num_ads != ref_inode_2->i_num_ads)
- return false;
- if (ref_inode_1->i_security_id != ref_inode_2->i_security_id
- || ref_inode_1->i_attributes != ref_inode_2->i_attributes)
- return false;
- for (unsigned i = 0; i <= ref_inode_1->i_num_ads; i++) {
- const u8 *ref_1_hash, *ref_2_hash;
- ref_1_hash = inode_stream_hash(ref_inode_1, i);
- ref_2_hash = inode_stream_hash(ref_inode_2, i);
- if (!hashes_equal(ref_1_hash, ref_2_hash))
- return false;
- if (i && !ads_entries_have_same_name(&ref_inode_1->i_ads_entries[i - 1],
- &ref_inode_2->i_ads_entries[i - 1]))
- return false;
-
- }
- return true;
-}
-
-static bool
-inodes_consistent(const struct wim_inode * restrict ref_inode,
- const struct wim_inode * restrict inode)
-{
- wimlib_assert(ref_inode != inode);
-
- if (ref_inode->i_num_ads != inode->i_num_ads &&
- inode->i_num_ads != 0)
- return false;
- if (ref_inode->i_security_id != inode->i_security_id
- || ref_inode->i_attributes != inode->i_attributes)
- return false;
- for (unsigned i = 0; i <= min(ref_inode->i_num_ads, inode->i_num_ads); i++) {
- const u8 *ref_hash, *hash;
- ref_hash = inode_stream_hash(ref_inode, i);
- hash = inode_stream_hash(inode, i);
- if (!hashes_equal(ref_hash, hash) && !is_zero_hash(hash))
- return false;
- if (i && !ads_entries_have_same_name(&ref_inode->i_ads_entries[i - 1],
- &inode->i_ads_entries[i - 1]))
- return false;
- }
- return true;
-}
-
-/* Fix up a "true" inode and check for inconsistencies */
-static int
-fix_true_inode(struct wim_inode *inode, struct list_head *inode_list)
-{
- struct wim_dentry *dentry;
- struct wim_dentry *ref_dentry = NULL;
- struct wim_inode *ref_inode;
- u64 last_ctime = 0;
- u64 last_mtime = 0;
- u64 last_atime = 0;
-
- inode_for_each_dentry(dentry, inode) {
- if (!ref_dentry || dentry->d_inode->i_num_ads > ref_dentry->d_inode->i_num_ads)
- ref_dentry = dentry;
- if (dentry->d_inode->i_creation_time > last_ctime)
- last_ctime = dentry->d_inode->i_creation_time;
- if (dentry->d_inode->i_last_write_time > last_mtime)
- last_mtime = dentry->d_inode->i_last_write_time;
- if (dentry->d_inode->i_last_access_time > last_atime)
- last_atime = dentry->d_inode->i_last_access_time;
- }
-
- ref_inode = ref_dentry->d_inode;
- wimlib_assert(ref_inode->i_nlink == 1);
- list_add_tail(&ref_inode->i_list, inode_list);
-
- list_del(&inode->i_dentry);
- list_add(&ref_inode->i_dentry, &ref_dentry->d_alias);
-
- inode_for_each_dentry(dentry, ref_inode) {
- if (dentry != ref_dentry) {
- if (!inodes_consistent(ref_inode, dentry->d_inode)) {
- inconsistent_inode(ref_inode);
- return WIMLIB_ERR_INVALID_METADATA_RESOURCE;
- }
- /* Free the unneeded `struct wim_inode'. */
- wimlib_assert(dentry->d_inode->i_nlink == 1);
- free_inode(dentry->d_inode);
- dentry->d_inode = ref_inode;
- ref_inode->i_nlink++;
- }
- }
- ref_inode->i_creation_time = last_ctime;
- ref_inode->i_last_write_time = last_mtime;
- ref_inode->i_last_access_time = last_atime;
- wimlib_assert(inode_link_count(ref_inode) == ref_inode->i_nlink);
- return 0;
-}
-
-/*
- * Fixes up a nominal inode.
- *
- * By a nominal inode we mean a group of two or more dentries that share the
- * same hard link group ID.
- *
- * If dentries in the inode are found to be inconsistent, we may split the inode
- * into several "true" inodes.
- *
- * After splitting up each nominal inode into the "true" inodes we will
- * canonicalize the link group by getting rid of all the unnecessary `struct
- * wim_inode's. There will be just one `struct wim_inode' for each hard link
- * group remaining.
- */
-static int
-fix_nominal_inode(struct wim_inode *inode, struct list_head *inode_list,
- bool *ino_changes_needed)
-{
- struct wim_dentry *dentry;
- struct hlist_node *cur, *tmp;
- int ret;
- size_t num_true_inodes;
-
- LIST_HEAD(dentries_with_data_streams);
- LIST_HEAD(dentries_with_no_data_streams);
- HLIST_HEAD(true_inodes);
-
- /* Create a list of dentries in the nominal inode that have at
- * least one data stream with a non-zero hash, and another list that
- * contains the dentries that have a zero hash for all data streams. */
- inode_for_each_dentry(dentry, inode) {
- for (unsigned i = 0; i <= dentry->d_inode->i_num_ads; i++) {
- const u8 *hash;
- hash = inode_stream_hash(dentry->d_inode, i);
- if (!is_zero_hash(hash)) {
- list_add(&dentry->tmp_list,
- &dentries_with_data_streams);
- goto next_dentry;
- }
- }
- list_add(&dentry->tmp_list,
- &dentries_with_no_data_streams);
- next_dentry:
- ;
- }
-
- /* If there are no dentries with data streams, we require the nominal
- * inode to be a true inode */
- if (list_empty(&dentries_with_data_streams)) {
- #ifdef ENABLE_DEBUG
- unsigned nominal_group_size = inode_link_count(inode);
- if (nominal_group_size > 1) {
- DEBUG("Found link group of size %u without "
- "any data streams:", nominal_group_size);
- print_inode_dentries(inode);
- DEBUG("We are going to interpret it as true "
- "link group, provided that the dentries "
- "are consistent.");
- }
- #endif
- return fix_true_inode(inode, inode_list);
- }
-
- /* One or more dentries had data streams specified. We check each of
- * these dentries for consistency with the others to form a set of true
- * inodes. */
- num_true_inodes = 0;
- list_for_each_entry(dentry, &dentries_with_data_streams, tmp_list) {
- /* Look for a true inode that is consistent with this dentry and
- * add this dentry to it. Or, if none of the true inodes are
- * consistent with this dentry, add a new one (if that happens,
- * we have split the hard link group). */
- hlist_for_each_entry(inode, cur, &true_inodes, i_hlist) {
- if (ref_inodes_consistent(inode, dentry->d_inode)) {
- inode_add_dentry(dentry, inode);
- goto next_dentry_2;
- }
- }
- num_true_inodes++;
- INIT_LIST_HEAD(&dentry->d_inode->i_dentry);
- inode_add_dentry(dentry, dentry->d_inode);
- hlist_add_head(&dentry->d_inode->i_hlist, &true_inodes);
-next_dentry_2:
- ;
- }
-
- wimlib_assert(num_true_inodes != 0);
-
- /* If there were dentries with no data streams, we require there to only
- * be one true inode so that we know which inode to assign the
- * streamless dentries to. */
- if (!list_empty(&dentries_with_no_data_streams)) {
- if (num_true_inodes != 1) {
- ERROR("Hard link ambiguity detected!");
- ERROR("We split up inode 0x%"PRIx64" due to "
- "inconsistencies,", inode->i_ino);
- ERROR("but dentries with no stream information remained. "
- "We don't know which inode");
- ERROR("to assign them to.");
- ret = WIMLIB_ERR_INVALID_METADATA_RESOURCE;
- goto out_cleanup_true_inode_list;
- }
- inode = container_of(true_inodes.first, struct wim_inode, i_hlist);
- /* Assign the streamless dentries to the one and only true
- * inode. */
- list_for_each_entry(dentry, &dentries_with_no_data_streams, tmp_list)
- inode_add_dentry(dentry, inode);
- }
- if (num_true_inodes != 1) {
- #ifdef ENABLE_DEBUG
- inode = container_of(true_inodes.first, struct wim_inode, i_hlist);
-
- tprintf(T("Split nominal inode 0x%"PRIx64" into %zu "
- "inodes:\n"), inode->i_ino, num_true_inodes);
- tputs(T("----------------------------------------------------"
- "--------------------------"));
- size_t i = 1;
- hlist_for_each_entry(inode, cur, &true_inodes, i_hlist) {
- tprintf(T("[Split inode %zu]\n"), i++);
- print_inode_dentries(inode);
- tputchar(T('\n'));
- }
- tputs(T("----------------------------------------------------"
- "--------------------------"));
- #endif
- *ino_changes_needed = true;
- }
-
- hlist_for_each_entry_safe(inode, cur, tmp, &true_inodes, i_hlist) {
- hlist_del_init(&inode->i_hlist);
- ret = fix_true_inode(inode, inode_list);
- if (ret)
- goto out_cleanup_true_inode_list;
- }
- ret = 0;
- goto out;
-out_cleanup_true_inode_list:
- hlist_for_each_entry_safe(inode, cur, tmp, &true_inodes, i_hlist)
- hlist_del_init(&inode->i_hlist);
-out:
- return ret;
-}
-
-static int
-fix_inodes(struct wim_inode_table *table, struct list_head *inode_list,
- bool *ino_changes_needed)
-{
- struct wim_inode *inode;
- struct hlist_node *cur, *tmp;
- int ret;
- INIT_LIST_HEAD(inode_list);
- for (u64 i = 0; i < table->capacity; i++) {
- hlist_for_each_entry_safe(inode, cur, tmp, &table->array[i], i_hlist) {
- hlist_del_init(&inode->i_hlist);
- ret = fix_nominal_inode(inode, inode_list, ino_changes_needed);
- if (ret)
- return ret;
- }
- }
- list_splice_tail(&table->extra_inodes, inode_list);
- return 0;
-}
-
-/*
- * dentry_tree_fix_inodes():
- *
- * This function takes as input a tree of WIM dentries that initially has a
- * different inode associated with each dentry. Sets of dentries that should
- * share the same inode (a.k.a. hard link groups) are built using the i_ino
- * field of each inode, then the link count and alias list for one inode in each
- * set is set correctly and the unnecessary struct wim_inode's freed. The
- * effect is to correctly associate exactly one struct wim_inode with each
- * original inode, regardless of how many dentries are aliases for that inode.
- *
- * The special inode number of 0 indicates that the dentry is in a hard link
- * group by itself, and therefore has a 'struct wim_inode' with i_nlink=1 to
- * itself.
- *
- * This function also checks the dentries in each hard link group for
- * consistency. In some WIMs, such as install.wim for some versions of Windows
- * 7, dentries can share the same hard link group ID but not actually be hard
- * linked to each other (based on conflicting information, such as file
- * contents). This should be an error, but this case needs be handled. So,
- * each "nominal" inode (the inode based on the inode numbers provided in the
- * WIM) is examined for consistency and may be split into multiple "true" inodes
- * that are maximally sized consistent sets of dentries.
- *
- * On success, the list of "true" inodes, linked by the i_hlist field,
- * is returned in the hlist @inode_list.
- *
- * Return values:
- * WIMLIB_ERR_SUCCESS (0)
- * WIMLIB_ERR_INVALID_METADATA_RESOURCE
- * WIMLIB_ERR_NOMEM
- */
-int
-dentry_tree_fix_inodes(struct wim_dentry *root, struct list_head *inode_list)
-{
- struct wim_inode_table inode_tab;
- int ret;
- bool ino_changes_needed;
- struct wim_inode *inode;
-
- DEBUG("Inserting dentries into inode table");
- ret = init_inode_table(&inode_tab, 9001);
- if (ret)
- goto out;
-
- ret = for_dentry_in_tree(root, inode_table_insert, &inode_tab);
- if (ret)
- goto out_destroy_inode_table;
-
- DEBUG("Cleaning up the hard link groups");
- ino_changes_needed = false;
- ret = fix_inodes(&inode_tab, inode_list, &ino_changes_needed);
- if (ret)
- goto out_destroy_inode_table;
-
- if (ino_changes_needed) {
- u64 cur_ino = 1;
-
- WARNING("Re-assigning inode numbers due to inode inconsistencies");
- list_for_each_entry(inode, inode_list, i_list) {
- if (inode->i_nlink > 1)
- inode->i_ino = cur_ino++;
- else
- inode->i_ino = 0;
- }
- }
- /* On success, all the inodes have been moved to the image inode list,
- * so there's no need to delete from from the hash lists in the inode
- * table before freeing the hash buckets array directly. */
- ret = 0;
- goto out_destroy_inode_table_raw;
-out_destroy_inode_table:
- for (size_t i = 0; i < inode_tab.capacity; i++) {
- struct hlist_node *cur, *tmp;
- hlist_for_each_entry_safe(inode, cur, tmp, &inode_tab.array[i], i_hlist)
- hlist_del_init(&inode->i_hlist);
- }
- {
- struct wim_inode *tmp;
- list_for_each_entry_safe(inode, tmp, &inode_tab.extra_inodes, i_list)
- list_del_init(&inode->i_list);
- }
-out_destroy_inode_table_raw:
- destroy_inode_table(&inode_tab);
-out:
- return ret;
-}
-
-/* Assign consecutive inode numbers to a new set of inodes from the inode table,
- * and append the inodes to a single list @head that contains the inodes already
- * existing in the WIM image. */
-void
-inode_table_prepare_inode_list(struct wim_inode_table *table,
- struct list_head *head)
-{
- struct wim_inode *inode, *tmp_inode;
- struct hlist_node *cur, *tmp;
- u64 cur_ino = 1;
-
- /* Re-assign inode numbers in the existing list to avoid duplicates. */
- list_for_each_entry(inode, head, i_list)
- inode->i_ino = cur_ino++;
-
- /* Assign inode numbers to the new inodes and move them to the image's
- * inode list. */
- for (size_t i = 0; i < table->capacity; i++) {
- hlist_for_each_entry_safe(inode, cur, tmp, &table->array[i], i_hlist)
- {
- inode->i_ino = cur_ino++;
- inode->i_devno = 0;
- list_add_tail(&inode->i_list, head);
- }
- INIT_HLIST_HEAD(&table->array[i]);
- }
- list_for_each_entry_safe(inode, tmp_inode, &table->extra_inodes, i_list)
- {
- inode->i_ino = cur_ino++;
- inode->i_devno = 0;
- list_add_tail(&inode->i_list, head);
- }
- INIT_LIST_HEAD(&table->extra_inodes);
- table->num_entries = 0;
-}
git://wimlib.net / wimlib / blobdiff