Annotation of sys/ufs/ufs/dir.h, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: dir.h,v 1.10 2005/06/18 18:09:43 millert Exp $ */
2: /* $NetBSD: dir.h,v 1.8 1996/03/09 19:42:41 scottr Exp $ */
3:
4: /*
5: * Copyright (c) 1982, 1986, 1989, 1993
6: * The Regents of the University of California. All rights reserved.
7: * (c) UNIX System Laboratories, Inc.
8: * All or some portions of this file are derived from material licensed
9: * to the University of California by American Telephone and Telegraph
10: * Co. or Unix System Laboratories, Inc. and are reproduced herein with
11: * the permission of UNIX System Laboratories, Inc.
12: *
13: * Redistribution and use in source and binary forms, with or without
14: * modification, are permitted provided that the following conditions
15: * are met:
16: * 1. Redistributions of source code must retain the above copyright
17: * notice, this list of conditions and the following disclaimer.
18: * 2. Redistributions in binary form must reproduce the above copyright
19: * notice, this list of conditions and the following disclaimer in the
20: * documentation and/or other materials provided with the distribution.
21: * 3. Neither the name of the University nor the names of its contributors
22: * may be used to endorse or promote products derived from this software
23: * without specific prior written permission.
24: *
25: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35: * SUCH DAMAGE.
36: *
37: * @(#)dir.h 8.4 (Berkeley) 8/10/94
38: */
39:
40: #ifndef _DIR_H_
41: #define _DIR_H_
42:
43: /*
44: * Theoretically, directories can be more than 2Gb in length, however, in
45: * practice this seems unlikely. So, we define the type doff_t as a 32-bit
46: * quantity to keep down the cost of doing lookup on a 32-bit machine.
47: */
48: #define doff_t int32_t
49: #define MAXDIRSIZE (0x7fffffff)
50:
51: /*
52: * A directory consists of some number of blocks of DIRBLKSIZ
53: * bytes, where DIRBLKSIZ is chosen such that it can be transferred
54: * to disk in a single atomic operation (e.g. 512 bytes on most machines).
55: *
56: * Each DIRBLKSIZ byte block contains some number of directory entry
57: * structures, which are of variable length. Each directory entry has
58: * a struct direct at the front of it, containing its inode number,
59: * the length of the entry, and the length of the name contained in
60: * the entry. These are followed by the name padded to a 4 byte boundary
61: * with null bytes. All names are guaranteed null terminated.
62: * The maximum length of a name in a directory is MAXNAMLEN.
63: *
64: * The macro DIRSIZ(fmt, dp) gives the amount of space required to represent
65: * a directory entry. Free space in a directory is represented by
66: * entries which have dp->d_reclen > DIRSIZ(fmt, dp). All DIRBLKSIZ bytes
67: * in a directory block are claimed by the directory entries. This
68: * usually results in the last entry in a directory having a large
69: * dp->d_reclen. When entries are deleted from a directory, the
70: * space is returned to the previous entry in the same directory
71: * block by increasing its dp->d_reclen. If the first entry of
72: * a directory block is free, then its dp->d_ino is set to 0.
73: * Entries other than the first in a directory do not normally have
74: * dp->d_ino set to 0.
75: */
76: #define DIRBLKSIZ DEV_BSIZE
77: #define MAXNAMLEN 255
78:
79: struct direct {
80: u_int32_t d_ino; /* inode number of entry */
81: u_int16_t d_reclen; /* length of this record */
82: u_int8_t d_type; /* file type, see below */
83: u_int8_t d_namlen; /* length of string in d_name */
84: char d_name[MAXNAMLEN + 1];/* name with length <= MAXNAMLEN */
85: };
86:
87: /*
88: * File types
89: */
90: #define DT_UNKNOWN 0
91: #define DT_FIFO 1
92: #define DT_CHR 2
93: #define DT_DIR 4
94: #define DT_BLK 6
95: #define DT_REG 8
96: #define DT_LNK 10
97: #define DT_SOCK 12
98:
99: /*
100: * Convert between stat structure types and directory types.
101: */
102: #define IFTODT(mode) (((mode) & 0170000) >> 12)
103: #define DTTOIF(dirtype) ((dirtype) << 12)
104:
105: /*
106: * The DIRSIZ macro gives the minimum record length which will hold
107: * the directory entry. This requires the amount of space in struct direct
108: * without the d_name field, plus enough space for the name with a terminating
109: * null byte (dp->d_namlen+1), rounded up to a 4 byte boundary.
110: */
111: #define DIRECTSIZ(namlen) \
112: (((int)&((struct direct *)0)->d_name + \
113: ((namlen)+1)*sizeof(((struct direct *)0)->d_name[0]) + 3) & ~3)
114: #if (BYTE_ORDER == LITTLE_ENDIAN)
115: #define DIRSIZ(oldfmt, dp) \
116: ((oldfmt) ? \
117: ((sizeof(struct direct) - (MAXNAMLEN+1)) + (((dp)->d_type+1 + 3) &~ 3)) : \
118: ((sizeof(struct direct) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3)))
119: #else
120: #define DIRSIZ(oldfmt, dp) \
121: ((sizeof(struct direct) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3))
122: #endif
123: #define OLDDIRFMT 1
124: #define NEWDIRFMT 0
125:
126: /*
127: * Template for manipulating directories. Should use struct direct's,
128: * but the name field is MAXNAMLEN - 1, and this just won't do.
129: */
130: struct dirtemplate {
131: u_int32_t dot_ino;
132: int16_t dot_reclen;
133: u_int8_t dot_type;
134: u_int8_t dot_namlen;
135: char dot_name[4]; /* must be multiple of 4 */
136: u_int32_t dotdot_ino;
137: int16_t dotdot_reclen;
138: u_int8_t dotdot_type;
139: u_int8_t dotdot_namlen;
140: char dotdot_name[4]; /* ditto */
141: };
142:
143: /*
144: * This is the old format of directories, sanz type element.
145: */
146: struct odirtemplate {
147: u_int32_t dot_ino;
148: int16_t dot_reclen;
149: u_int16_t dot_namlen;
150: char dot_name[4]; /* must be multiple of 4 */
151: u_int32_t dotdot_ino;
152: int16_t dotdot_reclen;
153: u_int16_t dotdot_namlen;
154: char dotdot_name[4]; /* ditto */
155: };
156: #endif /* !_DIR_H_ */
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