dir.h (5906B)
1 /* $Id: //depot/blt/srv/vfs/drivers/ffs/dir.h#1 $ */ 2 /* OpenBSD: dir.h,v 1.6 1997/05/30 08:34:56 downsj Exp */ 3 /* NetBSD: dir.h,v 1.8 1996/03/09 19:42:41 scottr Exp */ 4 5 /* 6 * Copyright (c) 1982, 1986, 1989, 1993 7 * The Regents of the University of California. All rights reserved. 8 * (c) UNIX System Laboratories, Inc. 9 * All or some portions of this file are derived from material licensed 10 * to the University of California by American Telephone and Telegraph 11 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 12 * the permission of UNIX System Laboratories, Inc. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 3. All advertising materials mentioning features or use of this software 23 * must display the following acknowledgement: 24 * This product includes software developed by the University of 25 * California, Berkeley and its contributors. 26 * 4. Neither the name of the University nor the names of its contributors 27 * may be used to endorse or promote products derived from this software 28 * without specific prior written permission. 29 * 30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 33 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 40 * SUCH DAMAGE. 41 * 42 * @(#)dir.h 8.4 (Berkeley) 8/10/94 43 */ 44 45 #ifndef DIR_H 46 #define DIR_H 47 48 /* 49 * Theoretically, directories can be more than 2Gb in length, however, in 50 * practice this seems unlikely. So, we define the type doff_t as a 32-bit 51 * quantity to keep down the cost of doing lookup on a 32-bit machine. 52 */ 53 #define doff_t int32 54 #define MAXDIRSIZE (0x7fffffff) 55 56 /* 57 * A directory consists of some number of blocks of DIRBLKSIZE 58 * bytes, where DIRBLKSIZE is chosen such that it can be transferred 59 * to disk in a single atomic operation (e.g. 512 bytes on most machines). 60 * 61 * Each DIRBLKSIZE byte block contains some number of directory entry 62 * structures, which are of variable length. Each directory entry has 63 * a struct direct at the front of it, containing its inode number, 64 * the length of the entry, and the length of the name contained in 65 * the entry. These are followed by the name padded to a 4 byte boundary 66 * with null bytes. All names are guaranteed null terminated. 67 * The maximum length of a name in a directory is MAXNAMLEN. 68 * 69 * The macro DIRSIZ(fmt, dp) gives the amount of space required to represent 70 * a directory entry. Free space in a directory is represented by 71 * entries which have dp->d_reclen > DIRSIZ(fmt, dp). All DIRBLKSIZE bytes 72 * in a directory block are claimed by the directory entries. This 73 * usually results in the last entry in a directory having a large 74 * dp->d_reclen. When entries are deleted from a directory, the 75 * space is returned to the previous entry in the same directory 76 * block by increasing its dp->d_reclen. If the first entry of 77 * a directory block is free, then its dp->d_ino is set to 0. 78 * Entries other than the first in a directory do not normally have 79 * dp->d_ino set to 0. 80 */ 81 #ifndef DIRBLKSIZE 82 #define DIRBLKSIZE DEV_BSIZE 83 #endif 84 #define MAXNAMLEN 255 85 86 struct ffs_direct { 87 uint32 d_ino; /* inode number of entry */ 88 uint16 d_reclen; /* length of this record */ 89 uint8 d_type; /* file type, see below */ 90 uint8 d_namlen; /* length of string in d_name */ 91 char d_name[MAXNAMLEN + 1];/* name with length <= MAXNAMLEN */ 92 }; 93 94 /* 95 * File types 96 */ 97 #define DT_UNKNOWN 0 98 #define DT_FIFO 1 99 #define DT_CHR 2 100 #define DT_DIR 4 101 #define DT_BLK 6 102 #define DT_REG 8 103 #define DT_LNK 10 104 #define DT_SOCK 12 105 #define DT_WHT 14 106 107 /* 108 * Convert between stat structure types and directory types. 109 */ 110 #define IFTODT(mode) (((mode) & 0170000) >> 12) 111 #define DTTOIF(dirtype) ((dirtype) << 12) 112 113 /* 114 * The DIRSIZ macro gives the minimum record length which will hold 115 * the directory entry. This requires the amount of space in struct direct 116 * without the d_name field, plus enough space for the name with a terminating 117 * null byte (dp->d_namlen+1), rounded up to a 4 byte boundary. 118 */ 119 #if (BYTE_ORDER == LITTLE_ENDIAN) 120 #define DIRSIZ(oldfmt, dp) \ 121 ((oldfmt) ? \ 122 ((sizeof(struct direct) - (MAXNAMLEN+1)) + (((dp)->d_type+1 + 3) &~ 3)) : \ 123 ((sizeof(struct direct) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3))) 124 #else 125 #define DIRSIZ(oldfmt, dp) \ 126 ((sizeof(struct direct) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3)) 127 #endif 128 #define OLDDIRFMT 1 129 #define NEWDIRFMT 0 130 131 /* 132 * Template for manipulating directories. Should use struct direct's, 133 * but the name field is MAXNAMLEN - 1, and this just won't do. 134 */ 135 struct dirtemplate { 136 uint32 dot_ino; 137 int16 dot_reclen; 138 uint8 dot_type; 139 uint8 dot_namlen; 140 char dot_name[4]; /* must be multiple of 4 */ 141 uint32 dotdot_ino; 142 int16 dotdot_reclen; 143 uint8 dotdot_type; 144 uint8 dotdot_namlen; 145 char dotdot_name[4]; /* ditto */ 146 }; 147 148 #endif 149