sys/ufs/ext2fs/ext2fs_dir.h

   1 /*      $NetBSD: ext2fs_dir.h,v 1.19 2012/05/09 00:21:18 riastradh Exp $        */
   2
   3 /*
   4  * Copyright (c) 1982, 1986, 1989, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  * (c) UNIX System Laboratories, Inc.
   7  * All or some portions of this file are derived from material licensed
   8  * to the University of California by American Telephone and Telegraph
   9  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
  10  * the permission of UNIX System Laboratories, Inc.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  * 3. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  *
  36  *      @(#)dir.h       8.4 (Berkeley) 8/10/94
  37  * Modified for ext2fs by Manuel Bouyer.
  38  */
  39
  40 /*
  41  * Copyright (c) 1997 Manuel Bouyer.
  42  *
  43  * Redistribution and use in source and binary forms, with or without
  44  * modification, are permitted provided that the following conditions
  45  * are met:
  46  * 1. Redistributions of source code must retain the above copyright
  47  *    notice, this list of conditions and the following disclaimer.
  48  * 2. Redistributions in binary form must reproduce the above copyright
  49  *    notice, this list of conditions and the following disclaimer in the
  50  *    documentation and/or other materials provided with the distribution.
  51  *
  52  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  53  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  54  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  55  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  56  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  57  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  58  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  59  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  60  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  61  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  62  *
  63  *      @(#)dir.h       8.4 (Berkeley) 8/10/94
  64  * Modified for ext2fs by Manuel Bouyer.
  65  */
  66
  67 #ifndef _UFS_EXT2FS_EXT2FS_DIR_H_
  68 #define _UFS_EXT2FS_EXT2FS_DIR_H_
  69
  70 #include <ufs/ext2fs/ext2fs_dinode.h>
  71
  72 /*
  73  * Theoretically, directories can be more than 2Gb in length, however, in
  74  * practice this seems unlikely. So, we define the type doff_t as a 32-bit
  75  * quantity to keep down the cost of doing lookup on a 32-bit machine.
  76  */
  77 #define doff_t                  int32_t
  78 #define EXT2FS_MAXDIRSIZE       INT32_MAX
  79
  80 /*
  81  * A directory consists of some number of blocks of e2fs_bsize bytes.
  82  *
  83  * Each block contains some number of directory entry
  84  * structures, which are of variable length.  Each directory entry has
  85  * a struct direct at the front of it, containing its inode number,
  86  * the length of the entry, and the length of the name contained in
  87  * the entry.  These are followed by the name padded to a 4 byte boundary
  88  * with null bytes.  All names are guaranteed null terminated.
  89  * The maximum length of a name in a directory is EXT2FS_MAXNAMLEN.
  90  *
  91  * The macro EXT2FS_DIRSIZ(fmt, dp) gives the amount of space required to
  92  * represent a directory entry.  Free space in a directory is represented by
  93  * entries which have dp->e2d_reclen > DIRSIZ(fmt, dp).  All d2fs_bsize bytes
  94  * in a directory block are claimed by the directory entries.  This
  95  * usually results in the last entry in a directory having a large
  96  * dp->e2d_reclen.  When entries are deleted from a directory, the
  97  * space is returned to the previous entry in the same directory
  98  * block by increasing its dp->e2d_reclen.  If the first entry of
  99  * a directory block is free, then its dp->e2d_ino is set to 0.
 100  * Entries other than the first in a directory do not normally have
 101  * dp->e2d_ino set to 0.
 102  * Ext2 rev 0 has a 16 bits e2d_namlen. For Ext2 vev 1 this has been split
 103  * into a 8 bits e2d_namlen and 8 bits e2d_type (looks like ffs, isnt't it ? :)
 104  * It's safe to use this for rev 0 as well because all ext2 are little-endian.
 105  */
 106
 107 #define EXT2FS_MAXNAMLEN        255
 108
 109 struct  ext2fs_direct {
 110         uint32_t e2d_ino;               /* inode number of entry */
 111         uint16_t e2d_reclen;            /* length of this record */
 112         uint8_t e2d_namlen;             /* length of string in d_name */
 113         uint8_t e2d_type;               /* file type */
 114         char e2d_name[EXT2FS_MAXNAMLEN];/* name with length<=EXT2FS_MAXNAMLEN */
 115 };
 116
 117 /* Ext2 directory file types (not the same as FFS. Sigh.) */
 118 #define EXT2_FT_UNKNOWN         0
 119 #define EXT2_FT_REG_FILE        1
 120 #define EXT2_FT_DIR             2
 121 #define EXT2_FT_CHRDEV          3
 122 #define EXT2_FT_BLKDEV          4
 123 #define EXT2_FT_FIFO            5
 124 #define EXT2_FT_SOCK            6
 125 #define EXT2_FT_SYMLINK         7
 126
 127 #define EXT2_FT_MAX             8
 128
 129 #define E2IFTODT(mode)    (((mode) & 0170000) >> 12)
 130
 131 static __inline uint8_t inot2ext2dt(uint16_t) __unused;
 132 static __inline uint8_t
 133 inot2ext2dt(uint16_t type)
 134 {
 135
 136         switch (type) {
 137         case E2IFTODT(EXT2_IFIFO):
 138                 return EXT2_FT_FIFO;
 139         case E2IFTODT(EXT2_IFCHR):
 140                 return EXT2_FT_CHRDEV;
 141         case E2IFTODT(EXT2_IFDIR):
 142                 return EXT2_FT_DIR;
 143         case E2IFTODT(EXT2_IFBLK):
 144                 return EXT2_FT_BLKDEV;
 145         case E2IFTODT(EXT2_IFREG):
 146                 return EXT2_FT_REG_FILE;
 147         case E2IFTODT(EXT2_IFLNK):
 148                 return EXT2_FT_SYMLINK;
 149         case E2IFTODT(EXT2_IFSOCK):
 150                 return EXT2_FT_SOCK;
 151         default:
 152                 return 0;
 153         }
 154 }
 155
 156 /*
 157  * The EXT2FS_DIRSIZ macro gives the minimum record length which will hold
 158  * the directory entryfor a name len "len" (without the terminating null byte).
 159  * This requires the amount of space in struct direct
 160  * without the d_name field, plus enough space for the name without a
 161  * terminating null byte, rounded up to a 4 byte boundary.
 162  */
 163 #define EXT2FS_DIRSIZ(len)      roundup2(8 + len, 4)
 164
 165 /*
 166  * Template for manipulating directories.  Should use struct direct's,
 167  * but the name field is EXT2FS_MAXNAMLEN - 1, and this just won't do.
 168  */
 169 struct ext2fs_dirtemplate {
 170         uint32_t        dot_ino;
 171         int16_t         dot_reclen;
 172         uint8_t         dot_namlen;
 173         uint8_t         dot_type;
 174         char            dot_name[4];    /* must be multiple of 4 */
 175         uint32_t        dotdot_ino;
 176         int16_t         dotdot_reclen;
 177         uint8_t         dotdot_namlen;
 178         uint8_t         dotdot_type;
 179         char            dotdot_name[4]; /* ditto */
 180 };
 181
 182 #endif /* !_UFS_EXT2FS_EXT2FS_DIR_H_ */