kernel: Move GPL'd kernel files to sys/gnu to have them all in one place.
[dragonfly.git] / sys / gnu / vfs / ext2fs / dir.h
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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: src/sys/ufs/ufs/dir.h,v 1.9 1999/08/28 00:52:27 peter Exp $
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40 */
41
42#ifndef _VFS_GNU_EXT2FS_DIR_H_
43#define _VFS_GNU_EXT2FS_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
81struct direct {
82 uint32_t d_ino; /* inode number of entry */
83 uint16_t d_reclen; /* length of this record */
84 uint8_t d_type; /* file type, see below */
85 uint8_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 *
b993bb87 114 *
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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 */
133struct dirtemplate {
134 uint32_t dot_ino;
135 int16_t dot_reclen;
136 uint8_t dot_type;
137 uint8_t dot_namlen;
138 char dot_name[4]; /* must be multiple of 4 */
139 uint32_t dotdot_ino;
140 int16_t dotdot_reclen;
141 uint8_t dotdot_type;
142 uint8_t dotdot_namlen;
143 char dotdot_name[4]; /* ditto */
144};
145
146/*
147 * This is the old format of directories, sanz type element.
148 */
149struct odirtemplate {
150 uint32_t dot_ino;
151 int16_t dot_reclen;
152 uint16_t dot_namlen;
153 char dot_name[4]; /* must be multiple of 4 */
154 uint32_t dotdot_ino;
155 int16_t dotdot_reclen;
156 uint16_t dotdot_namlen;
157 char dotdot_name[4]; /* ditto */
158};
159#endif /* _VFS_GNU_EXT2FS_DIR_H_ */