6 * Copyright (C) 2012, 2013, 2014 Eric Biggers
8 * This file is free software; you can redistribute it and/or modify it under
9 * the terms of the GNU Lesser General Public License as published by the Free
10 * Software Foundation; either version 3 of the License, or (at your option) any
13 * This file is distributed in the hope that it will be useful, but WITHOUT
14 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
15 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
18 * You should have received a copy of the GNU Lesser General Public License
19 * along with this file; if not, see http://www.gnu.org/licenses/.
26 #include "wimlib/dentry.h"
27 #include "wimlib/error.h"
28 #include "wimlib/inode.h"
29 #include "wimlib/inode_table.h"
31 struct inode_fixup_params {
32 struct wim_inode_table inode_table;
33 unsigned long num_dir_hard_links;
34 unsigned long num_inconsistent_inodes;
37 #define MAX_DIR_HARD_LINK_WARNINGS 8
40 inodes_consistent(const struct wim_inode *inode_1,
41 const struct wim_inode *inode_2)
43 /* This certainly isn't the only thing we need to check to make sure the
44 * inodes are consistent. However, this seems to be the only thing that
45 * the MS implementation checks when working around its own bug.
47 * (Tested: If two dentries share the same hard link group ID, Windows
48 * 8.1 DISM will link them if they have the same unnamed stream hash,
49 * even if the dentries provide different timestamps, attributes,
50 * alternate data streams, and security IDs! And the one that gets used
51 * will change if you merely swap the filenames. But if you use
52 * different unnamed stream hashes with everything else the same, it
53 * doesn't link the dentries.)
55 * For non-buggy WIMs this function will always return true. */
56 return hashes_equal(inode_get_hash_of_unnamed_data_stream(inode_1),
57 inode_get_hash_of_unnamed_data_stream(inode_2));
61 inode_table_insert(struct wim_dentry *dentry, void *_params)
63 struct inode_fixup_params *params = _params;
64 struct wim_inode_table *table = ¶ms->inode_table;
65 struct wim_inode *d_inode = dentry->d_inode;
67 struct wim_inode *inode;
69 if (d_inode->i_ino == 0) {
70 hlist_add_head(&d_inode->i_hlist_node, &table->extra_inodes);
74 /* Try adding this dentry to an existing inode. */
75 pos = d_inode->i_ino % table->capacity;
76 hlist_for_each_entry(inode, &table->array[pos], i_hlist_node) {
77 if (inode->i_ino != d_inode->i_ino) {
80 if (unlikely(!inodes_consistent(inode, d_inode))) {
81 params->num_inconsistent_inodes++;
84 if (unlikely((d_inode->i_attributes & FILE_ATTRIBUTE_DIRECTORY) ||
85 (inode->i_attributes & FILE_ATTRIBUTE_DIRECTORY)))
87 params->num_dir_hard_links++;
88 if (params->num_dir_hard_links <=
89 MAX_DIR_HARD_LINK_WARNINGS)
91 WARNING("Unsupported directory hard link "
92 "\"%"TS"\" <=> \"%"TS"\"",
93 dentry_full_path(dentry),
94 inode_first_full_path(inode));
95 } else if (params->num_dir_hard_links ==
96 MAX_DIR_HARD_LINK_WARNINGS + 1)
98 WARNING("Suppressing additional warnings about "
99 "directory hard links...");
103 /* Transfer this dentry to the existing inode. */
104 d_disassociate(dentry);
105 d_associate(dentry, inode);
109 /* Keep this dentry's inode. */
110 hlist_add_head(&d_inode->i_hlist_node, &table->array[pos]);
115 hlist_move_all(struct hlist_head *src, struct hlist_head *dest)
117 struct hlist_node *node;
119 while ((node = src->first) != NULL) {
121 hlist_add_head(node, dest);
125 /* Move the inodes from the 'struct wim_inode_table' to the 'inode_list'. */
127 build_inode_list(struct wim_inode_table *inode_table,
128 struct hlist_head *inode_list)
130 hlist_move_all(&inode_table->extra_inodes, inode_list);
131 for (size_t i = 0; i < inode_table->capacity; i++)
132 hlist_move_all(&inode_table->array[i], inode_list);
135 /* Re-assign inode numbers to the inodes in the list. */
137 reassign_inode_numbers(struct hlist_head *inode_list)
139 struct wim_inode *inode;
142 hlist_for_each_entry(inode, inode_list, i_hlist_node)
143 inode->i_ino = cur_ino++;
147 * Given a WIM image's tree of dentries such that each dentry initially
148 * has a unique inode associated with it, determine the actual
149 * dentry/inode information. Following this, a single inode may be named
150 * by more than one dentry (usually called a hard link).
152 * The 'hard_link_group_id' field of the on-disk WIM dentry, which we
153 * have read into 'i_ino' of each dentry's initial inode, determines
154 * which dentries share the same inode. Ideally, dentries share the same
155 * inode if and only if they have the same value in this field. However,
158 * - If 'hard_link_group_id' is 0, the corresponding dentry is the sole
159 * name for its inode.
160 * - Due to bugs in the Microsoft implementation, dentries with different
161 * 'hard_link_group_id' fields may, in fact, need to be interpreted as
162 * naming different inodes. This seems to mostly affect images in
163 * install.wim for Windows 7. I try to work around this in the same way
164 * the Microsoft implementation works around this.
166 * Returns 0 or WIMLIB_ERR_NOMEM. On success, the resulting inodes will be
167 * appended to the @inode_list, and they will have consistent numbers in their
171 dentry_tree_fix_inodes(struct wim_dentry *root, struct hlist_head *inode_list)
173 struct inode_fixup_params params;
176 /* We use a hash table to map inode numbers to inodes. */
178 ret = init_inode_table(¶ms.inode_table, 9001);
182 params.num_dir_hard_links = 0;
183 params.num_inconsistent_inodes = 0;
185 for_dentry_in_tree(root, inode_table_insert, ¶ms);
187 /* Generate the resulting list of inodes, and if needed reassign
188 * the inode numbers. */
189 build_inode_list(¶ms.inode_table, inode_list);
190 destroy_inode_table(¶ms.inode_table);
192 if (unlikely(params.num_inconsistent_inodes))
193 WARNING("Fixed %lu invalid hard links in WIM image",
194 params.num_inconsistent_inodes);
196 if (unlikely(params.num_dir_hard_links))
197 WARNING("Ignoring %lu directory hard links",
198 params.num_dir_hard_links);
200 if (unlikely(params.num_inconsistent_inodes ||
201 params.num_dir_hard_links))
202 reassign_inode_numbers(inode_list);