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37 #ifndef _UFS_UFS_DIR_H_
38 #define _UFS_UFS_DIR_H_
41 * Theoretically, directories can be more than 2Gb in length, however, in
42 * practice this seems unlikely. So, we define the type doff_t as a 32-bit
43 * quantity to keep down the cost of doing lookup on a 32-bit machine.
45 #define doff_t int32_t
46 #define MAXDIRSIZE (0x7fffffff)
49 * A directory consists of some number of blocks of DIRBLKSIZ
50 * bytes, where DIRBLKSIZ is chosen such that it can be transferred
51 * to disk in a single atomic operation (e.g. 512 bytes on most machines).
53 * Each DIRBLKSIZ byte block contains some number of directory entry
54 * structures, which are of variable length. Each directory entry has
55 * a struct direct at the front of it, containing its inode number,
56 * the length of the entry, and the length of the name contained in
57 * the entry. These are followed by the name padded to a 4 byte boundary
58 * with null bytes. All names are guaranteed null terminated.
59 * The maximum length of a name in a directory is UFS_MAXNAMLEN.
61 * The macro DIRSIZ(fmt, dp) gives the amount of space required to represent
62 * a directory entry. Free space in a directory is represented by
63 * entries which have dp->d_reclen > DIRSIZ(fmt, dp). All DIRBLKSIZ bytes
64 * in a directory block are claimed by the directory entries. This
65 * usually results in the last entry in a directory having a large
66 * dp->d_reclen. When entries are deleted from a directory, the
67 * space is returned to the previous entry in the same directory
68 * block by increasing its dp->d_reclen. If the first entry of
69 * a directory block is free, then its dp->d_ino is set to 0.
70 * Entries other than the first in a directory do not normally have
73 #define DIRBLKSIZ DEV_BSIZE
74 #define UFS_MAXNAMLEN 255
77 uint32_t d_ino; /* inode number of entry */
78 uint16_t d_reclen; /* length of this record */
79 uint8_t d_type; /* file type, see below */
80 uint8_t d_namlen; /* length of string in d_name */
81 char d_name[UFS_MAXNAMLEN + 1];
82 /* name with length <= UFS_MAXNAMLEN */
99 * Convert between stat structure types and directory types.
101 #define IFTODT(mode) (((mode) & 0170000) >> 12)
102 #define DTTOIF(dirtype) ((dirtype) << 12)
105 * The DIRSIZ macro gives the minimum record length which will hold
106 * the directory entry. This requires the amount of space in struct direct
107 * without the d_name field, plus enough space for the name with a terminating
108 * null byte (dp->d_namlen + 1), rounded up to a 4 byte boundary.
110 #define DIR_ROUNDUP 4 /* Directory name roundup size */
111 #define DIRECTSIZ(namlen) \
112 (roundup2(__offsetof(struct direct, d_name) + (namlen) + 1, DIR_ROUNDUP))
113 #if (BYTE_ORDER == LITTLE_ENDIAN)
114 #define DIRSIZ(oldfmt, dp) \
115 ((oldfmt) ? DIRECTSIZ((dp)->d_type) : DIRECTSIZ((dp)->d_namlen))
117 #define DIRSIZ(oldfmt, dp) \
118 DIRECTSIZ((dp)->d_namlen)
124 * Template for manipulating directories. Should use struct direct's,
125 * but the name field is UFS_MAXNAMLEN - 1, and this just won't do.
132 char dot_name[4]; /* must be multiple of 4 */
134 int16_t dotdot_reclen;
136 uint8_t dotdot_namlen;
137 char dotdot_name[4]; /* ditto */
141 * This is the old format of directories, sanz type element.
143 struct odirtemplate {
147 char dot_name[4]; /* must be multiple of 4 */
149 int16_t dotdot_reclen;
150 uint16_t dotdot_namlen;
151 char dotdot_name[4]; /* ditto */
153 #endif /* !_DIR_H_ */