bsd/ufs/ufs/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 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  23 /*
  24  * Copyright (c) 1982, 1986, 1989, 1993
  25  *      The Regents of the University of California.  All rights reserved.
  26  * (c) UNIX System Laboratories, Inc.
  27  * All or some portions of this file are derived from material licensed
  28  * to the University of California by American Telephone and Telegraph
  29  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
  30  * the permission of UNIX System Laboratories, Inc.
  31  *
  32  * Redistribution and use in source and binary forms, with or without
  33  * modification, are permitted provided that the following conditions
  34  * are met:
  35  * 1. Redistributions of source code must retain the above copyright
  36  *    notice, this list of conditions and the following disclaimer.
  37  * 2. Redistributions in binary form must reproduce the above copyright
  38  *    notice, this list of conditions and the following disclaimer in the
  39  *    documentation and/or other materials provided with the distribution.
  40  * 3. All advertising materials mentioning features or use of this software
  41  *    must display the following acknowledgement:
  42  *      This product includes software developed by the University of
  43  *      California, Berkeley and its contributors.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  *      @(#)dir.h       8.5 (Berkeley) 4/27/95
  61  */
  62
  63 #ifndef _DIR_H_
  64 #define _DIR_H_
  65
  66 /*
  67  * Theoretically, directories can be more than 2Gb in length, however, in
  68  * practice this seems unlikely. So, we define the type doff_t as a 32-bit
  69  * quantity to keep down the cost of doing lookup on a 32-bit machine.
  70  */
  71 #define doff_t          int32_t
  72 #define MAXDIRSIZE      (0x7fffffff)
  73
  74 /*
  75  * A directory consists of some number of blocks of DIRBLKSIZ
  76  * bytes, where DIRBLKSIZ is chosen such that it can be transferred
  77  * to disk in a single atomic operation (e.g. 512 bytes on most machines).
  78  *
  79  * Each DIRBLKSIZ byte block contains some number of directory entry
  80  * structures, which are of variable length.  Each directory entry has
  81  * a struct direct at the front of it, containing its inode number,
  82  * the length of the entry, and the length of the name contained in
  83  * the entry.  These are followed by the name padded to a 4 byte boundary
  84  * with null bytes.  All names are guaranteed null terminated.
  85  * The maximum length of a name in a directory is MAXNAMLEN.
  86  *
  87  * The macro DIRSIZ(fmt, dp) gives the amount of space required to represent
  88  * a directory entry.  Free space in a directory is represented by
  89  * entries which have dp->d_reclen > DIRSIZ(fmt, dp).  All DIRBLKSIZ bytes
  90  * in a directory block are claimed by the directory entries.  This
  91  * usually results in the last entry in a directory having a large
  92  * dp->d_reclen.  When entries are deleted from a directory, the
  93  * space is returned to the previous entry in the same directory
  94  * block by increasing its dp->d_reclen.  If the first entry of
  95  * a directory block is free, then its dp->d_ino is set to 0.
  96  * Entries other than the first in a directory do not normally have
  97  * dp->d_ino set to 0.
  98  */
  99 #ifdef __APPLE__
 100 #define DIRBLKSIZ       1024
 101 #else
 102 #define DIRBLKSIZ       DEV_BSIZE
 103 #endif
 104 #define MAXNAMLEN       255
 105
 106 struct  direct {
 107         u_int32_t d_ino;                /* inode number of entry */
 108         u_int16_t d_reclen;             /* length of this record */
 109         u_int8_t  d_type;               /* file type, see below */
 110         u_int8_t  d_namlen;             /* length of string in d_name */
 111         char      d_name[MAXNAMLEN + 1];/* name with length <= MAXNAMLEN */
 112 };
 113
 114 /*
 115  * File types
 116  */
 117 #define DT_UNKNOWN       0
 118 #define DT_FIFO          1
 119 #define DT_CHR           2
 120 #define DT_DIR           4
 121 #define DT_BLK           6
 122 #define DT_REG           8
 123 #define DT_LNK          10
 124 #define DT_SOCK         12
 125 #define DT_WHT          14
 126
 127 /*
 128  * Convert between stat structure types and directory types.
 129  */
 130 #define IFTODT(mode)    (((mode) & 0170000) >> 12)
 131 #define DTTOIF(dirtype) ((dirtype) << 12)
 132
 133 /*
 134  * The DIRSIZ macro gives the minimum record length which will hold
 135  * the directory entry.  This requires the amount of space in struct direct
 136  * without the d_name field, plus enough space for the name with a terminating
 137  * null byte (dp->d_namlen+1), rounded up to a 4 byte boundary.
 138  */
 139 #if (BYTE_ORDER == LITTLE_ENDIAN)
 140 #define DIRSIZ(oldfmt, dp) \
 141     ((oldfmt) ? \
 142     ((sizeof(struct direct) - (MAXNAMLEN+1)) + (((dp)->d_type+1 + 3) &~ 3)) : \
 143     ((sizeof(struct direct) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3)))
 144 #else
 145 #define DIRSIZ(oldfmt, dp) \
 146     ((sizeof(struct direct) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3))
 147 #endif
 148 #define OLDDIRFMT       1
 149 #define NEWDIRFMT       0
 150
 151 /*
 152  * Template for manipulating directories.  Should use struct direct's,
 153  * but the name field is MAXNAMLEN - 1, and this just won't do.
 154  */
 155 struct dirtemplate {
 156         u_int32_t       dot_ino;
 157         int16_t         dot_reclen;
 158         u_int8_t        dot_type;
 159         u_int8_t        dot_namlen;
 160         char            dot_name[4];    /* must be multiple of 4 */
 161         u_int32_t       dotdot_ino;
 162         int16_t         dotdot_reclen;
 163         u_int8_t        dotdot_type;
 164         u_int8_t        dotdot_namlen;
 165         char            dotdot_name[4]; /* ditto */
 166 };
 167
 168 /*
 169  * This is the old format of directories, sanz type element.
 170  */
 171 struct odirtemplate {
 172         u_int32_t       dot_ino;
 173         int16_t         dot_reclen;
 174         u_int16_t       dot_namlen;
 175         char            dot_name[4];    /* must be multiple of 4 */
 176         u_int32_t       dotdot_ino;
 177         int16_t         dotdot_reclen;
 178         u_int16_t       dotdot_namlen;
 179         char            dotdot_name[4]; /* ditto */
 180 };
 181 #endif /* !_DIR_H_ */