1 /* $NetBSD: ext2fs_dir.h,v 1.1 1997/06/11 09:33:50 bouyer Exp $ */ 2 3 /* 4 * Copyright (c) 1997 Manuel Bouyer. 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. All advertising materials mentioning features or use of this software 22 * must display the following acknowledgement: 23 * This product includes software developed by the University of 24 * California, Berkeley and its contributors. 25 * 4. Neither the name of the University nor the names of its contributors 26 * may be used to endorse or promote products derived from this software 27 * without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 39 * SUCH DAMAGE. 40 * 41 * @(#)dir.h 8.4 (Berkeley) 8/10/94 42 * Modified for ext2fs by Manuel Bouyer. 43 */ 44 45 #ifndef _EXT2FS_DIR_H_ 46 #define _EXT2FS_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_t 54 #define EXT2FS_MAXDIRSIZE (0x7fffffff) 55 56 /* 57 * A directory consists of some number of blocks of e2fs_bsize bytes. 58 * 59 * Each block contains some number of directory entry 60 * structures, which are of variable length. Each directory entry has 61 * a struct direct at the front of it, containing its inode number, 62 * the length of the entry, and the length of the name contained in 63 * the entry. These are followed by the name padded to a 4 byte boundary 64 * with null bytes. All names are guaranteed null terminated. 65 * The maximum length of a name in a directory is EXT2FS_MAXNAMLEN. 66 * 67 * The macro EXT2FS_DIRSIZ(fmt, dp) gives the amount of space required to 68 * represent a directory entry. Free space in a directory is represented by 69 * entries which have dp->e2d_reclen > DIRSIZ(fmt, dp). All d2fs_bsize bytes 70 * in a directory block are claimed by the directory entries. This 71 * usually results in the last entry in a directory having a large 72 * dp->e2d_reclen. When entries are deleted from a directory, the 73 * space is returned to the previous entry in the same directory 74 * block by increasing its dp->e2d_reclen. If the first entry of 75 * a directory block is free, then its dp->e2d_ino is set to 0. 76 * Entries other than the first in a directory do not normally have 77 * dp->e2d_ino set to 0. 78 */ 79 80 #define EXT2FS_MAXNAMLEN 255 81 82 struct ext2fs_direct { 83 u_int32_t e2d_ino; /* inode number of entry */ 84 u_int16_t e2d_reclen; /* length of this record */ 85 u_int16_t e2d_namlen; /* length of string in d_name */ 86 char e2d_name[EXT2FS_MAXNAMLEN];/* name with length <= EXT2FS_MAXNAMLEN */ 87 }; 88 89 /* 90 * The EXT2FS_DIRSIZ macro gives the minimum record length which will hold 91 * the directory entryfor a name len "len" (without the terminating null byte). 92 * This requires the amount of space in struct direct 93 * without the d_name field, plus enough space for the name without a 94 * terminating null byte, rounded up to a 4 byte boundary. 95 */ 96 #define EXT2FS_DIRSIZ(len) \ 97 (( 8 + len + 3) &~ 3) 98 99 /* 100 * Template for manipulating directories. Should use struct direct's, 101 * but the name field is EXT2FS_MAXNAMLEN - 1, and this just won't do. 102 */ 103 struct ext2fs_dirtemplate { 104 u_int32_t dot_ino; 105 int16_t dot_reclen; 106 u_int16_t dot_namlen; 107 char dot_name[4]; /* must be multiple of 4 */ 108 u_int32_t dotdot_ino; 109 int16_t dotdot_reclen; 110 u_int16_t dotdot_namlen; 111 char dotdot_name[4]; /* ditto */ 112 }; 113 114 #endif /* !_EXT2FS_DIR_H_ */ 115