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  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*      $NetBSD: ext2fs_dir.h,v 1.4 2000/01/28 16:00:23 bouyer Exp $    */
  23 /*
  24  * Copyright (c) 1997 Manuel Bouyer.
  25  * Copyright (c) 1982, 1986, 1989, 1993
  26  *      The Regents of the University of California.  All rights reserved.
  27  * (c) UNIX System Laboratories, Inc.
  28  * All or some portions of this file are derived from material licensed
  29  * to the University of California by American Telephone and Telegraph
  30  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
  31  * the permission of UNIX System Laboratories, Inc.
  32  *
  33  * Redistribution and use in source and binary forms, with or without
  34  * modification, are permitted provided that the following conditions
  35  * are met:
  36  * 1. Redistributions of source code must retain the above copyright
  37  *    notice, this list of conditions and the following disclaimer.
  38  * 2. Redistributions in binary form must reproduce the above copyright
  39  *    notice, this list of conditions and the following disclaimer in the
  40  *    documentation and/or other materials provided with the distribution.
  41  * 3. All advertising materials mentioning features or use of this software
  42  *    must display the following acknowledgement:
  43  *      This product includes software developed by the University of
  44  *      California, Berkeley and its contributors.
  45  * 4. Neither the name of the University nor the names of its contributors
  46  *    may be used to endorse or promote products derived from this software
  47  *    without specific prior written permission.
  48  *
  49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  59  * SUCH DAMAGE.
  60  *
  61  *      @(#)dir.h       8.4 (Berkeley) 8/10/94
  62  * Modified for ext2fs by Manuel Bouyer.
  63  */
  64 /*
  65  *  ext2fs_dir.h - Headers for Ext2 disk directory structures.
  66  *
  67  *  Copyright (c) 2000 Apple Computer, Inc.
  68  *
  69  *  DRI: Josh de Cesare
  70  */
  71
  72 #ifndef _EXT2FS_DIR_H_
  73 #define _EXT2FS_DIR_H_
  74
  75 /*
  76  * Theoretically, directories can be more than 2Gb in length, however, in
  77  * practice this seems unlikely. So, we define the type doff_t as a 32-bit
  78  * quantity to keep down the cost of doing lookup on a 32-bit machine.
  79  */
  80 #define doff_t          int32_t
  81 #define EXT2FS_MAXDIRSIZE       (0x7fffffff)
  82
  83 /*
  84  * A directory consists of some number of blocks of e2fs_bsize bytes.
  85  *
  86  * Each block contains some number of directory entry
  87  * structures, which are of variable length.  Each directory entry has
  88  * a struct direct at the front of it, containing its inode number,
  89  * the length of the entry, and the length of the name contained in
  90  * the entry.  These are followed by the name padded to a 4 byte boundary
  91  * with null bytes.  All names are guaranteed null terminated.
  92  * The maximum length of a name in a directory is EXT2FS_MAXNAMLEN.
  93  *
  94  * The macro EXT2FS_DIRSIZ(fmt, dp) gives the amount of space required to
  95  * represent a directory entry.  Free space in a directory is represented by
  96  * entries which have dp->e2d_reclen > DIRSIZ(fmt, dp).  All d2fs_bsize bytes
  97  * in a directory block are claimed by the directory entries.  This
  98  * usually results in the last entry in a directory having a large
  99  * dp->e2d_reclen.  When entries are deleted from a directory, the
 100  * space is returned to the previous entry in the same directory
 101  * block by increasing its dp->e2d_reclen.  If the first entry of
 102  * a directory block is free, then its dp->e2d_ino is set to 0.
 103  * Entries other than the first in a directory do not normally have
 104  * dp->e2d_ino set to 0.
 105  * Ext2 rev 0 has a 16 bits e2d_namlen. For Ext2 vev 1 this has been split
 106  * into a 8 bits e2d_namlen and 8 bits e2d_type (looks like ffs, isnt't it ? :)
 107  * It's safe to use this for rev 0 as well because all ext2 are little-endian.
 108  */
 109
 110 #define EXT2FS_MAXNAMLEN        255
 111
 112 struct  ext2fs_direct {
 113         u_int32_t e2d_ino;              /* inode number of entry */
 114         u_int16_t e2d_reclen;           /* length of this record */
 115         u_int8_t e2d_namlen;            /* length of string in d_name */
 116         u_int8_t e2d_type;              /* file type */
 117         char      e2d_name[EXT2FS_MAXNAMLEN];/* name with length <= EXT2FS_MAXNAMLEN */
 118 };
 119
 120 /* Ext2 directory file types (not the same as FFS. Sigh. */
 121 #define EXT2_FT_UNKNOWN         0
 122 #define EXT2_FT_REG_FILE        1
 123 #define EXT2_FT_DIR             2
 124 #define EXT2_FT_CHRDEV          3
 125 #define EXT2_FT_BLKDEV          4
 126 #define EXT2_FT_FIFO            5
 127 #define EXT2_FT_SOCK            6
 128 #define EXT2_FT_SYMLINK         7
 129
 130 #define EXT2_FT_MAX             8
 131
 132 #define E2IFTODT(mode)    (((mode) & 0170000) >> 12)
 133
 134 static __inline__ u_int8_t inot2ext2dt __P((u_int16_t))
 135     __attribute__((__unused__));
 136 static __inline__ u_int8_t
 137 inot2ext2dt(type)
 138         u_int16_t type;
 139 {
 140         switch(type) {
 141         case E2IFTODT(EXT2_IFIFO):
 142                 return EXT2_FT_FIFO;
 143         case E2IFTODT(EXT2_IFCHR):
 144                 return EXT2_FT_CHRDEV;
 145         case E2IFTODT(EXT2_IFDIR):
 146                 return EXT2_FT_DIR;
 147         case E2IFTODT(EXT2_IFBLK):
 148                 return EXT2_FT_BLKDEV;
 149         case E2IFTODT(EXT2_IFREG):
 150                 return EXT2_FT_REG_FILE;
 151         case E2IFTODT(EXT2_IFLNK):
 152                 return EXT2_FT_SYMLINK;
 153         case E2IFTODT(EXT2_IFSOCK):
 154                 return EXT2_FT_SOCK;
 155         default:
 156                 return 0;
 157         }
 158 }
 159
 160 /*
 161  * The EXT2FS_DIRSIZ macro gives the minimum record length which will hold
 162  * the directory entryfor a name len "len" (without the terminating null byte).
 163  * This requires the amount of space in struct direct
 164  * without the d_name field, plus enough space for the name without a
 165  * terminating null byte, rounded up to a 4 byte boundary.
 166  */
 167 #define EXT2FS_DIRSIZ(len) \
 168    (( 8 + len + 3) &~ 3)
 169
 170 /*
 171  * Template for manipulating directories.  Should use struct direct's,
 172  * but the name field is EXT2FS_MAXNAMLEN - 1, and this just won't do.
 173  */
 174 struct ext2fs_dirtemplate {
 175         u_int32_t       dot_ino;
 176         int16_t         dot_reclen;
 177         u_int8_t        dot_namlen;
 178         u_int8_t        dot_type;
 179         char            dot_name[4];    /* must be multiple of 4 */
 180         u_int32_t       dotdot_ino;
 181         int16_t         dotdot_reclen;
 182         u_int8_t        dotdot_namlen;
 183         u_int8_t        dotdot_type;
 184         char            dotdot_name[4]; /* ditto */
 185 };
 186
 187 #endif /* !_EXT2FS_DIR_H_ */