bootx.tproj/fs.subproj/ext2fs_dir.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*      $NetBSD: ext2fs_dir.h,v 1.4 2000/01/28 16:00:23 bouyer Exp $    */
  26 /*
  27  * Copyright (c) 1997 Manuel Bouyer.
  28  * Copyright (c) 1982, 1986, 1989, 1993
  29  *      The Regents of the University of California.  All rights reserved.
  30  * (c) UNIX System Laboratories, Inc.
  31  * All or some portions of this file are derived from material licensed
  32  * to the University of California by American Telephone and Telegraph
  33  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
  34  * the permission of UNIX System Laboratories, Inc.
  35  *
  36  * Redistribution and use in source and binary forms, with or without
  37  * modification, are permitted provided that the following conditions
  38  * are met:
  39  * 1. Redistributions of source code must retain the above copyright
  40  *    notice, this list of conditions and the following disclaimer.
  41  * 2. Redistributions in binary form must reproduce the above copyright
  42  *    notice, this list of conditions and the following disclaimer in the
  43  *    documentation and/or other materials provided with the distribution.
  44  * 3. All advertising materials mentioning features or use of this software
  45  *    must display the following acknowledgement:
  46  *      This product includes software developed by the University of
  47  *      California, Berkeley and its contributors.
  48  * 4. Neither the name of the University nor the names of its contributors
  49  *    may be used to endorse or promote products derived from this software
  50  *    without specific prior written permission.
  51  *
  52  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  53  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  54  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  55  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  56  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  57  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  58  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  59  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  60  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  61  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  62  * SUCH DAMAGE.
  63  *
  64  *      @(#)dir.h       8.4 (Berkeley) 8/10/94
  65  * Modified for ext2fs by Manuel Bouyer.
  66  */
  67 /*
  68  *  ext2fs_dir.h - Headers for Ext2 disk directory structures.
  69  *
  70  *  Copyright (c) 2000 Apple Computer, Inc.
  71  *
  72  *  DRI: Josh de Cesare
  73  */
  74
  75 #ifndef _EXT2FS_DIR_H_
  76 #define _EXT2FS_DIR_H_
  77
  78 /*
  79  * Theoretically, directories can be more than 2Gb in length, however, in
  80  * practice this seems unlikely. So, we define the type doff_t as a 32-bit
  81  * quantity to keep down the cost of doing lookup on a 32-bit machine.
  82  */
  83 #define doff_t          int32_t
  84 #define EXT2FS_MAXDIRSIZE       (0x7fffffff)
  85
  86 /*
  87  * A directory consists of some number of blocks of e2fs_bsize bytes.
  88  *
  89  * Each block contains some number of directory entry
  90  * structures, which are of variable length.  Each directory entry has
  91  * a struct direct at the front of it, containing its inode number,
  92  * the length of the entry, and the length of the name contained in
  93  * the entry.  These are followed by the name padded to a 4 byte boundary
  94  * with null bytes.  All names are guaranteed null terminated.
  95  * The maximum length of a name in a directory is EXT2FS_MAXNAMLEN.
  96  *
  97  * The macro EXT2FS_DIRSIZ(fmt, dp) gives the amount of space required to
  98  * represent a directory entry.  Free space in a directory is represented by
  99  * entries which have dp->e2d_reclen > DIRSIZ(fmt, dp).  All d2fs_bsize bytes
 100  * in a directory block are claimed by the directory entries.  This
 101  * usually results in the last entry in a directory having a large
 102  * dp->e2d_reclen.  When entries are deleted from a directory, the
 103  * space is returned to the previous entry in the same directory
 104  * block by increasing its dp->e2d_reclen.  If the first entry of
 105  * a directory block is free, then its dp->e2d_ino is set to 0.
 106  * Entries other than the first in a directory do not normally have
 107  * dp->e2d_ino set to 0.
 108  * Ext2 rev 0 has a 16 bits e2d_namlen. For Ext2 vev 1 this has been split
 109  * into a 8 bits e2d_namlen and 8 bits e2d_type (looks like ffs, isnt't it ? :)
 110  * It's safe to use this for rev 0 as well because all ext2 are little-endian.
 111  */
 112
 113 #define EXT2FS_MAXNAMLEN        255
 114
 115 struct  ext2fs_direct {
 116         u_int32_t e2d_ino;              /* inode number of entry */
 117         u_int16_t e2d_reclen;           /* length of this record */
 118         u_int8_t e2d_namlen;            /* length of string in d_name */
 119         u_int8_t e2d_type;              /* file type */
 120         char      e2d_name[EXT2FS_MAXNAMLEN];/* name with length <= EXT2FS_MAXNAMLEN */
 121 };
 122
 123 /* Ext2 directory file types (not the same as FFS. Sigh. */
 124 #define EXT2_FT_UNKNOWN         0
 125 #define EXT2_FT_REG_FILE        1
 126 #define EXT2_FT_DIR             2
 127 #define EXT2_FT_CHRDEV          3
 128 #define EXT2_FT_BLKDEV          4
 129 #define EXT2_FT_FIFO            5
 130 #define EXT2_FT_SOCK            6
 131 #define EXT2_FT_SYMLINK         7
 132
 133 #define EXT2_FT_MAX             8
 134
 135 #define E2IFTODT(mode)    (((mode) & 0170000) >> 12)
 136
 137 static __inline__ u_int8_t inot2ext2dt __P((u_int16_t))
 138     __attribute__((__unused__));
 139 static __inline__ u_int8_t
 140 inot2ext2dt(type)
 141         u_int16_t type;
 142 {
 143         switch(type) {
 144         case E2IFTODT(EXT2_IFIFO):
 145                 return EXT2_FT_FIFO;
 146         case E2IFTODT(EXT2_IFCHR):
 147                 return EXT2_FT_CHRDEV;
 148         case E2IFTODT(EXT2_IFDIR):
 149                 return EXT2_FT_DIR;
 150         case E2IFTODT(EXT2_IFBLK):
 151                 return EXT2_FT_BLKDEV;
 152         case E2IFTODT(EXT2_IFREG):
 153                 return EXT2_FT_REG_FILE;
 154         case E2IFTODT(EXT2_IFLNK):
 155                 return EXT2_FT_SYMLINK;
 156         case E2IFTODT(EXT2_IFSOCK):
 157                 return EXT2_FT_SOCK;
 158         default:
 159                 return 0;
 160         }
 161 }
 162
 163 /*
 164  * The EXT2FS_DIRSIZ macro gives the minimum record length which will hold
 165  * the directory entryfor a name len "len" (without the terminating null byte).
 166  * This requires the amount of space in struct direct
 167  * without the d_name field, plus enough space for the name without a
 168  * terminating null byte, rounded up to a 4 byte boundary.
 169  */
 170 #define EXT2FS_DIRSIZ(len) \
 171    (( 8 + len + 3) &~ 3)
 172
 173 /*
 174  * Template for manipulating directories.  Should use struct direct's,
 175  * but the name field is EXT2FS_MAXNAMLEN - 1, and this just won't do.
 176  */
 177 struct ext2fs_dirtemplate {
 178         u_int32_t       dot_ino;
 179         int16_t         dot_reclen;
 180         u_int8_t        dot_namlen;
 181         u_int8_t        dot_type;
 182         char            dot_name[4];    /* must be multiple of 4 */
 183         u_int32_t       dotdot_ino;
 184         int16_t         dotdot_reclen;
 185         u_int8_t        dotdot_namlen;
 186         u_int8_t        dotdot_type;
 187         char            dotdot_name[4]; /* ditto */
 188 };
 189
 190 #endif /* !_EXT2FS_DIR_H_ */