/* Size of the struct dentry up to and including the file_name_len. */
#define WIM_DENTRY_DISK_SIZE 102
+/* Size of on-disk WIM alternate data stream entry, in bytes, up to and
+ * including the stream length field (see below). */
#define WIM_ADS_ENTRY_DISK_SIZE 38
+
/*
* Reparse tags documented at
* http://msdn.microsoft.com/en-us/library/dd541667(v=prot.10).aspx
struct lookup_table_entry;
-/* Alternate data stream entry */
+/* Alternate data stream entry.
+ *
+ * We read this from disk in the read_ads_entries() function; see that function
+ * for more explanation. */
struct ads_entry {
union {
/* SHA-1 message digest of stream contents */
struct stream_list_head lte_group_list;
};
-static inline u64 ads_entry_length(const struct ads_entry *entry)
+/* 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 inline u64 ads_entry_total_length(const struct ads_entry *entry)
{
u64 len = WIM_ADS_ENTRY_DISK_SIZE + entry->stream_name_len + 2;
return (len + 7) & ~7;
}
-/* In-memory structure for a WIM directory entry. There is a directory tree for
- * each image in the WIM. */
+/*
+ * In-memory structure for a WIM directory entry (dentry). There is a directory
+ * tree for each image in the WIM.
+ *
+ * Please note that this is a directory entry and not an inode. Since NTFS
+ * allows hard links, it's possible for a NTFS inode to correspond to multiple
+ * WIM dentries. The @hard_link field tells you the number of the NTFS inode
+ * that the dentry corresponds to.
+ *
+ * Unfortunately, WIM files do not have an analogue to an inode; instead certain
+ * information, such as file attributes, the security descriptor, and file
+ * streams is replicated in each hard-linked dentry, even though this
+ * information really is associated with an inode.
+ *
+ * Confusingly, it's also possible for stream information to be missing from a
+ * dentry in a hard link set, in which case the stream information needs to be
+ * gotten from one of the other dentries in the hard link set. In addition, it
+ * is possible for dentries to have inconsistent security IDs, file attributes,
+ * or file streams when they share the same hard link ID (don't even ask. I
+ * hope that Microsoft may have fixed this problem, since I've only noticed it
+ * in the 'install.wim' for Windows 7). For those dentries, we have to use the
+ * conflicting fields to split up the hard link groups.
+ */
struct dentry {
/* The parent of this directory entry. */
struct dentry *parent;
/* Linked list of sibling directory entries. */
struct dentry *next;
-
struct dentry *prev;
/* Pointer to a child of this directory entry. */
struct dentry *children;
- /* Size of directory entry on disk, in bytes. Typical size is around
+ /*
+ * Size of directory entry on disk, in bytes. Typical size is around
* 104 to 120 bytes.
*
* It is possible for the length field to be 0. This situation, which
*/
u64 length;
- /* The file attributes associated with this file. */
+ /* The file attributes associated with this file. This is a bitwise OR
+ * of the FILE_ATTRIBUTE_* flags. */
u32 attributes;
/* The index of the security descriptor in the WIM image's table of
* If -1, no security information exists for this file. */
int32_t security_id;
- /* The offset, from the start of the WIM metadata resource for this
- * image, of this directory entry's child files. 0 if the directory
- * entry has no children (as in the case of regular files or reparse
- * points). */
+ /* The offset, from the start of the uncompressed WIM metadata resource
+ * for this image, of this dentry's child dentries. 0 if the directory
+ * entry has no children, which is the case for regular files or reparse
+ * points. */
u64 subdir_offset;
/* Timestamps for the dentry. The timestamps are the number of
* 100-nanosecond intervals that have elapsed since 12:00 A.M., January
- * 1st, 1601, UTC. */
+ * 1st, 1601, UTC. This is the same format used in NTFS inodes. */
u64 creation_time;
u64 last_access_time;
u64 last_write_time;
- /* true if the dentry's lookup table entry has been resolved (i.e. the
- * @lte field is valid, but the @hash field is not valid) */
+ /* %true iff the dentry's lookup table entry has been resolved (i.e. the
+ * @lte field is valid, but the @hash field is not valid)
+ *
+ * (This is not an on-disk field.) */
bool resolved;
/* A hash of the file's contents, or a pointer to the lookup table entry
* read_dentry() function. */
//u32 reparse_reserved;
+ /* If the file is part of a hard link set, all the directory entries in
+ * the set will share the same value for this field.
+ *
+ * Unfortunately, in some WIMs it is NOT the case that all dentries that
+ * share this field are actually in the same hard link set, although the
+ * WIMs that wimlib writes maintain this restriction. */
+ u64 hard_link;
+
/* Number of alternate data streams associated with this file. */
u16 num_ads;
* the terminating zero byte. */
u16 file_name_utf8_len;
- /* Pointer to the short filename */
+ /* Pointer to the short filename (malloc()ed buffer) */
char *short_name;
- /* Pointer to the filename. */
+ /* Pointer to the filename (malloc()ed buffer). */
char *file_name;
- /* Pointer to the filename converted to UTF-8. */
+ /* Pointer to the filename converted to UTF-8 (malloc()ed buffer). */
char *file_name_utf8;
- /* Full path to this dentry. */
+ /* Full path to this dentry (malloc()ed buffer). */
char *full_path_utf8;
u32 full_path_utf8_len;
- /* Alternate stream entries for this dentry. */
+ /* Alternate stream entries for this dentry (malloc()ed buffer). */
struct ads_entry *ads_entries;
union {
u32 num_times_opened;
};
- /* If the file is part of a hard link set, all the directory entries in
- * the set will share the same value for this field.
- *
- * Unfortunately, in some WIMs it is NOT the case that all dentries that
- * share this field are actually in the same hard link set, although the
- * WIMs that wimlib writes maintain this restriction. */
- u64 hard_link;
-
enum {
/* This dentry is the owner of its ads_entries, although it may
* be in a hard link set */
/* List of dentries sharing the same lookup table entry */
struct stream_list_head lte_group_list;
- /* Path to extracted file on disk (used during extraction only) */
+ /* Path to extracted file on disk (used during extraction only)
+ * (malloc()ed buffer) */
char *extracted_file;
};
-/* Return the number of dentries in the hard link group */
-static inline size_t dentry_link_group_size(const struct dentry *dentry)
-{
- const struct list_head *cur = &dentry->link_group_list;
- size_t size = 0;
- wimlib_assert(cur != NULL);
- do {
- size++;
- cur = cur->next;
- } while (cur != &dentry->link_group_list);
- return size;
-}
-
extern struct ads_entry *dentry_get_ads_entry(struct dentry *dentry,
const char *stream_name);
extern u8 *write_dentry_tree(const struct dentry *tree, u8 *p);
-/* Inline utility functions for dentries */
+/* Return the number of dentries in the hard link group */
+static inline size_t dentry_link_group_size(const struct dentry *dentry)
+{
+ const struct list_head *cur = &dentry->link_group_list;
+ size_t size = 0;
+ wimlib_assert(cur != NULL);
+ do {
+ size++;
+ cur = cur->next;
+ } while (cur != &dentry->link_group_list);
+ return size;
+}
static inline bool dentry_is_root(const struct dentry *dentry)
{
git://wimlib.net / wimlib / blobdiff