![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to ffs_dir.h CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [Isaki's NoNo m68k/m88k emulator] / nono / host|
Return to ffs_dir.h CVS log | Up to [Isaki's NoNo m68k/m88k emulator] / nono / host |
1.1 root 1: /* $NetBSD: dir.h,v 1.27 2019/05/05 15:07:12 christos Exp $ */
2:
3: /*
4: * Copyright (c) 1982, 1986, 1989, 1993
5: * The Regents of the University of California. All rights reserved.
6: * (c) UNIX System Laboratories, Inc.
7: * All or some portions of this file are derived from material licensed
8: * to the University of California by American Telephone and Telegraph
9: * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10: * the permission of UNIX System Laboratories, Inc.
11: *
12: * Redistribution and use in source and binary forms, with or without
13: * modification, are permitted provided that the following conditions
14: * are met:
15: * 1. Redistributions of source code must retain the above copyright
16: * notice, this list of conditions and the following disclaimer.
17: * 2. Redistributions in binary form must reproduce the above copyright
18: * notice, this list of conditions and the following disclaimer in the
19: * documentation and/or other materials provided with the distribution.
20: * 3. Neither the name of the University nor the names of its contributors
21: * may be used to endorse or promote products derived from this software
22: * without specific prior written permission.
23: *
24: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34: * SUCH DAMAGE.
35: *
36: * @(#)dir.h 8.5 (Berkeley) 4/27/95
37: */
38:
39: #ifndef _UFS_UFS_DIR_H_
40: #define _UFS_UFS_DIR_H_
41:
42: /*
43: * Theoretically, directories can be more than 2Gb in length; however, in
44: * practice this seems unlikely. So, we define the type doff_t as a 32-bit
45: * quantity to keep down the cost of doing lookup on a 32-bit machine.
46: */
47: #define doff_t int32_t
48: #define UFS_MAXDIRSIZE (0x7fffffff)
49:
50: /*
51: * A directory consists of some number of blocks of UFS_DIRBLKSIZ
52: * bytes, where UFS_DIRBLKSIZ is chosen such that it can be transferred
53: * to disk in a single atomic operation (e.g. 512 bytes on most machines).
54: *
55: * Each UFS_DIRBLKSIZ byte block contains some number of directory entry
56: * structures, which are of variable length. Each directory entry has
57: * a struct direct at the front of it, containing its inode number,
58: * the length of the entry, and the length of the name contained in
59: * the entry. These are followed by the name padded to a 4 byte boundary.
60: * All names are guaranteed null terminated.
61: * The maximum length of a name in a directory is FFS_MAXNAMLEN.
62: *
63: * The macro UFS_DIRSIZ(fmt, dp) gives the amount of space required to represent
64: * a directory entry. Free space in a directory is represented by
65: * entries which have dp->d_reclen > DIRSIZ(fmt, dp). All UFS_DIRBLKSIZ bytes
66: * in a directory block are claimed by the directory entries. This
67: * usually results in the last entry in a directory having a large
68: * dp->d_reclen. When entries are deleted from a directory, the
69: * space is returned to the previous entry in the same directory
70: * block by increasing its dp->d_reclen. If the first entry of
71: * a directory block is free, then its dp->d_ino is set to 0.
72: * Entries other than the first in a directory do not normally have
73: * dp->d_ino set to 0.
74: */
75: #undef UFS_DIRBLKSIZ
76: #define UFS_DIRBLKSIZ DEV_BSIZE
77: #define FFS_MAXNAMLEN 255
78: #define APPLEUFS_DIRBLKSIZ 1024
79:
80: #define d_ino d_fileno
81: struct direct {
82: u_int32_t d_fileno; /* 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[FFS_MAXNAMLEN + 1];/* name with length <= FFS_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 UFS_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: * NUL byte (dp->d_namlen+1), rounded up to a 4 byte boundary.
113: * The UFS_NAMEPAD macro gives the number bytes of padding needed including
114: * the NUL terminating byte.
115: */
116: #define DIR_ROUNDUP 4
117: #define UFS_NAMEROUNDUP(namlen) (((namlen) + DIR_ROUNDUP) & ~(DIR_ROUNDUP - 1))
118: #define UFS_NAMEPAD(namlen) (DIR_ROUNDUP - ((namlen) & (DIR_ROUNDUP - 1)))
119: #define UFS_DIRECTSIZ(namlen) \
120: ((sizeof(struct direct) - (FFS_MAXNAMLEN+1)) + UFS_NAMEROUNDUP(namlen))
121:
122: #if (BYTE_ORDER == LITTLE_ENDIAN)
123: #define UFS_DIRSIZ(oldfmt, dp, needswap) \
124: (((oldfmt) && !(needswap)) ? \
125: UFS_DIRECTSIZ((dp)->d_type) : UFS_DIRECTSIZ((dp)->d_namlen))
126: #else
127: #define UFS_DIRSIZ(oldfmt, dp, needswap) \
128: (((oldfmt) && (needswap)) ? \
129: UFS_DIRECTSIZ((dp)->d_type) : UFS_DIRECTSIZ((dp)->d_namlen))
130: #endif
131:
132: /*
133: * UFS_OLDDIRFMT and UFS_NEWDIRFMT are code numbers for a directory
134: * format change that happened in ffs a long time ago. (Back in the
135: * 80s, if I'm not mistaken.)
136: *
137: * These code numbers do not appear on disk. They're generated from
138: * runtime logic that is cued by other things, which is why
139: * UFS_OLDDIRFMT is confusingly 1 and UFS_NEWDIRFMT is confusingly 0.
140: *
141: * Relatedly, the FFS_EI byte swapping logic for directories is a
142: * horrible mess. For example, to access the namlen field, one
143: * currently does the following:
144: *
145: * #if (BYTE_ORDER == LITTLE_ENDIAN)
146: * swap = (UFS_IPNEEDSWAP(VTOI(vp)) == 0);
147: * #else
148: * swap = (UFS_IPNEEDSWAP(VTOI(vp)) != 0);
149: * #endif
150: * return ((FSFMT(vp) && swap) ? dp->d_type : dp->d_namlen);
151: *
152: * UFS_IPNEEDSWAP() returns true if the volume is opposite-endian. This
153: * horrible "swap" logic is cutpasted all over everywhere but amounts
154: * to the following:
155: *
156: * running code volume lfs_dobyteswap "swap"
157: * ----------------------------------------------------------
158: * LITTLE_ENDIAN LITTLE_ENDIAN false true
159: * LITTLE_ENDIAN BIG_ENDIAN true false
160: * BIG_ENDIAN LITTLE_ENDIAN true true
161: * BIG_ENDIAN BIG_ENDIAN false false
162: *
163: * which you'll note boils down to "volume is little-endian".
164: *
165: * Meanwhile, FSFMT(vp) yields UFS_OLDDIRFMT or UFS_NEWDIRFMT via
166: * perverted logic of its own. Since UFS_OLDDIRFMT is 1 (contrary to
167: * what one might expect approaching this cold) what this mess means
168: * is: on OLDDIRFMT volumes that are little-endian, we read the
169: * namlen value out of the type field. This is because on OLDDIRFMT
170: * volumes there is no d_type field, just a 16-bit d_namlen; so if
171: * the 16-bit d_namlen is little-endian, the useful part of it is
172: * in the first byte, which in the NEWDIRFMT structure is the d_type
173: * field.
174: */
175:
176: #define UFS_OLDDIRFMT 1
177: #define UFS_NEWDIRFMT 0
178:
179: /*
180: * Template for manipulating directories. Should use struct direct's,
181: * but the name field is FFS_MAXNAMLEN - 1, and this just won't do.
182: */
183: struct dirtemplate {
184: u_int32_t dot_ino;
185: int16_t dot_reclen;
186: u_int8_t dot_type;
187: u_int8_t dot_namlen;
188: char dot_name[4]; /* must be multiple of 4 */
189: u_int32_t dotdot_ino;
190: int16_t dotdot_reclen;
191: u_int8_t dotdot_type;
192: u_int8_t dotdot_namlen;
193: char dotdot_name[4]; /* ditto */
194: };
195:
196: /*
197: * This is the old format of directories, sans type element.
198: */
199: struct odirtemplate {
200: u_int32_t dot_ino;
201: int16_t dot_reclen;
202: u_int16_t dot_namlen;
203: char dot_name[4]; /* must be multiple of 4 */
204: u_int32_t dotdot_ino;
205: int16_t dotdot_reclen;
206: u_int16_t dotdot_namlen;
207: char dotdot_name[4]; /* ditto */
208: };
209: #endif /* !_UFS_UFS_DIR_H_ */
This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.