FreeBSD/Linux Kernel Cross Reference
sys/ufs/ufs/dir.h
1 /*
2 * Copyright (c) 1982, 1986, 1989, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 * @(#)dir.h 8.2 (Berkeley) 1/21/94
39 * $FreeBSD$
40 */
41
42 #ifndef _UFS_UFS_DIR_H_
43 #define _UFS_UFS_DIR_H_
44
45 /*
46 * Theoretically, directories can be more than 2Gb in length, however, in
47 * practice this seems unlikely. So, we define the type doff_t as a 32-bit
48 * quantity to keep down the cost of doing lookup on a 32-bit machine.
49 */
50 #define doff_t int32_t
51 #define MAXDIRSIZE (0x7fffffff)
52
53 /*
54 * A directory consists of some number of blocks of DIRBLKSIZ
55 * bytes, where DIRBLKSIZ is chosen such that it can be transferred
56 * to disk in a single atomic operation (e.g. 512 bytes on most machines).
57 *
58 * Each DIRBLKSIZ byte block contains some number of directory entry
59 * structures, which are of variable length. Each directory entry has
60 * a struct direct at the front of it, containing its inode number,
61 * the length of the entry, and the length of the name contained in
62 * the entry. These are followed by the name padded to a 4 byte boundary
63 * with null bytes. All names are guaranteed null terminated.
64 * The maximum length of a name in a directory is MAXNAMLEN.
65 *
66 * The macro DIRSIZ(fmt, dp) gives the amount of space required to represent
67 * a directory entry. Free space in a directory is represented by
68 * entries which have dp->d_reclen > DIRSIZ(fmt, dp). All DIRBLKSIZ bytes
69 * in a directory block are claimed by the directory entries. This
70 * usually results in the last entry in a directory having a large
71 * dp->d_reclen. When entries are deleted from a directory, the
72 * space is returned to the previous entry in the same directory
73 * block by increasing its dp->d_reclen. If the first entry of
74 * a directory block is free, then its dp->d_ino is set to 0.
75 * Entries other than the first in a directory do not normally have
76 * dp->d_ino set to 0.
77 */
78 #define DIRBLKSIZ DEV_BSIZE
79 #define MAXNAMLEN 255
80
81 struct direct {
82 u_int32_t d_ino; /* inode number of entry */
83 u_int16_t d_reclen; /* length of this record */
84 u_int8_t d_type; /* file type, see below */
85 u_int8_t d_namlen; /* length of string in d_name */
86 char d_name[MAXNAMLEN + 1];/* name with length <= MAXNAMLEN */
87 };
88
89 /*
90 * File types
91 */
92 #define DT_UNKNOWN 0
93 #define DT_FIFO 1
94 #define DT_CHR 2
95 #define DT_DIR 4
96 #define DT_BLK 6
97 #define DT_REG 8
98 #define DT_LNK 10
99 #define DT_SOCK 12
100 #define DT_WHT 14
101
102 /*
103 * Convert between stat structure types and directory types.
104 */
105 #define IFTODT(mode) (((mode) & 0170000) >> 12)
106 #define DTTOIF(dirtype) ((dirtype) << 12)
107
108 /*
109 * The DIRSIZ macro gives the minimum record length which will hold
110 * the directory entry. This requires the amount of space in struct direct
111 * without the d_name field, plus enough space for the name with a terminating
112 * null byte (dp->d_namlen+1), rounded up to a 4 byte boundary.
113 *
114 *
115 */
116 #define DIRECTSIZ(namlen) \
117 (((int)&((struct direct *)0)->d_name + \
118 ((namlen)+1)*sizeof(((struct direct *)0)->d_name[0]) + 3) & ~3)
119 #if (BYTE_ORDER == LITTLE_ENDIAN)
120 #define DIRSIZ(oldfmt, dp) \
121 ((oldfmt) ? DIRECTSIZ((dp)->d_type) : DIRECTSIZ((dp)->d_namlen))
122 #else
123 #define DIRSIZ(oldfmt, dp) \
124 DIRECTSIZ((dp)->d_namlen)
125 #endif
126 #define OLDDIRFMT 1
127 #define NEWDIRFMT 0
128
129 /*
130 * Template for manipulating directories. Should use struct direct's,
131 * but the name field is MAXNAMLEN - 1, and this just won't do.
132 */
133 struct dirtemplate {
134 u_int32_t dot_ino;
135 int16_t dot_reclen;
136 u_int8_t dot_type;
137 u_int8_t dot_namlen;
138 char dot_name[4]; /* must be multiple of 4 */
139 u_int32_t dotdot_ino;
140 int16_t dotdot_reclen;
141 u_int8_t dotdot_type;
142 u_int8_t dotdot_namlen;
143 char dotdot_name[4]; /* ditto */
144 };
145
146 /*
147 * This is the old format of directories, sanz type element.
148 */
149 struct odirtemplate {
150 u_int32_t dot_ino;
151 int16_t dot_reclen;
152 u_int16_t dot_namlen;
153 char dot_name[4]; /* must be multiple of 4 */
154 u_int32_t dotdot_ino;
155 int16_t dotdot_reclen;
156 u_int16_t dotdot_namlen;
157 char dotdot_name[4]; /* ditto */
158 };
159 #endif /* !_DIR_H_ */
Cache object: 792725685db3fb37fb4d7221342d940e
|