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. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)dir.h 8.2 (Berkeley) 1/21/94 35 * $FreeBSD: src/sys/ufs/ufs/dir.h,v 1.9 1999/08/28 00:52:27 peter Exp $ 36 * $DragonFly: src/sys/vfs/ufs/dir.h,v 1.4 2006/04/03 02:02:37 dillon Exp $ 37 */ 38 39 #ifndef _VFS_UFS_DIR_H_ 40 #define _VFS_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 MAXDIRSIZE (0x7fffffff) 49 50 /* 51 * A directory consists of some number of blocks of DIRBLKSIZ 52 * bytes, where 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 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 * with null bytes. All names are guaranteed null terminated. 61 * The maximum length of a name in a directory is MAXNAMLEN. 62 * 63 * The macro 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 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 #define DIRBLKSIZ DEV_BSIZE 76 #define MAXNAMLEN 255 77 78 struct direct { 79 uint32_t d_ino; /* inode number of entry */ 80 uint16_t d_reclen; /* length of this record */ 81 uint8_t d_type; /* file type, see below */ 82 uint8_t d_namlen; /* length of string in d_name */ 83 char d_name[MAXNAMLEN + 1];/* name with length <= MAXNAMLEN */ 84 }; 85 86 /* 87 * File types 88 */ 89 #define DT_UNKNOWN 0 90 #define DT_FIFO 1 91 #define DT_CHR 2 92 #define DT_DIR 4 93 #define DT_BLK 6 94 #define DT_REG 8 95 #define DT_LNK 10 96 #define DT_SOCK 12 97 #define DT_WHT 14 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 * 112 */ 113 #define DIRECTSIZ(namlen) \ 114 ((__offsetof(struct direct, d_name) + \ 115 ((namlen)+1)*sizeof(((struct direct *)0)->d_name[0]) + 3) & ~3) 116 #if (BYTE_ORDER == LITTLE_ENDIAN) 117 #define DIRSIZ(oldfmt, dp) \ 118 ((oldfmt) ? DIRECTSIZ((dp)->d_type) : DIRECTSIZ((dp)->d_namlen)) 119 #else 120 #define DIRSIZ(oldfmt, dp) \ 121 DIRECTSIZ((dp)->d_namlen) 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 uint32_t dot_ino; 132 int16_t dot_reclen; 133 uint8_t dot_type; 134 uint8_t dot_namlen; 135 char dot_name[4]; /* must be multiple of 4 */ 136 uint32_t dotdot_ino; 137 int16_t dotdot_reclen; 138 uint8_t dotdot_type; 139 uint8_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 uint32_t dot_ino; 148 int16_t dot_reclen; 149 uint16_t dot_namlen; 150 char dot_name[4]; /* must be multiple of 4 */ 151 uint32_t dotdot_ino; 152 int16_t dotdot_reclen; 153 uint16_t dotdot_namlen; 154 char dotdot_name[4]; /* ditto */ 155 }; 156 #endif /* !_VFS_UFS_DIR_H_ */ 157