include/sys/fs/ufs_fsdir.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 1998 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 /*
  31  * University Copyright- Copyright (c) 1982, 1986, 1988
  32  * The Regents of the University of California
  33  * All Rights Reserved
  34  *
  35  * University Acknowledgment- Portions of this document are derived from
  36  * software developed by the University of California, Berkeley, and its
  37  * contributors.
  38  */
  39
  40 #ifndef _SYS_FS_UFS_FSDIR_H
  41 #define _SYS_FS_UFS_FSDIR_H
  42
  43 #pragma ident   "%Z%%M% %I%     %E% SMI"
  44
  45 #ifdef  __cplusplus
  46 extern "C" {
  47 #endif
  48
  49 /*
  50  * A directory consists of some number of blocks of DIRBLKSIZ
  51  * bytes, where DIRBLKSIZ is chosen such that it can be transferred
  52  * to disk in a single atomic operation (e.g. 512 bytes on most machines).
  53  *
  54  * Each DIRBLKSIZ byte block contains some number of directory entry
  55  * structures, which are of variable length.  Each directory entry has
  56  * a struct direct at the front of it, containing its inode number,
  57  * the length of the entry, and the length of the name contained in
  58  * the entry.  These are followed by the name padded to a 4 byte boundary
  59  * with null bytes.  All names are guaranteed null terminated.
  60  * The maximum length of a name in a directory is MAXNAMLEN.
  61  *
  62  * The macro DIRSIZ(dp) gives the amount of space required to represent
  63  * a directory entry.  Free space in a directory is represented by
  64  * entries which have dp->d_reclen > DIRSIZ(dp).  All DIRBLKSIZ bytes
  65  * in a directory block are claimed by the directory entries.  This
  66  * usually results in the last entry in a directory having a large
  67  * dp->d_reclen.  When entries are deleted from a directory, the
  68  * space is returned to the previous entry in the same directory
  69  * block by increasing its dp->d_reclen.  If the first entry of
  70  * a directory block is free, then its dp->d_ino is set to 0.
  71  * Entries other than the first in a directory do not normally have
  72  * dp->d_ino set to 0.
  73  */
  74 #define DIRBLKSIZ       DEV_BSIZE
  75 #define MAXNAMLEN       255
  76
  77 struct  direct {
  78         uint32_t        d_ino;          /* inode number of entry */
  79         ushort_t        d_reclen;       /* length of this record */
  80         ushort_t        d_namlen;       /* length of string in d_name */
  81         char    d_name[MAXNAMLEN + 1];  /* name must be no longer than this */
  82 };
  83
  84 /*
  85  * The DIRSIZ macro gives the minimum record length which will hold
  86  * the directory entry.  This requires the amount of space in struct direct
  87  * without the d_name field, plus enough space for the name with a terminating
  88  * null byte (dp->d_namlen+1), rounded up to a 4 byte boundary.
  89  */
  90 #undef DIRSIZ
  91 #define DIRSIZ(dp) \
  92         ((sizeof (struct direct) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1+3) &~ 3))
  93
  94 #ifdef _KERNEL
  95 /*
  96  * Template for manipulating directories.
  97  * Should use struct direct's, but the name field
  98  * is MAXNAMLEN - 1, and this just won't do.
  99  */
 100 struct dirtemplate {
 101         uint32_t        dot_ino;
 102         short           dot_reclen;
 103         short           dot_namlen;
 104         char            dot_name[4];            /* must be multiple of 4 */
 105         uint32_t        dotdot_ino;
 106         short           dotdot_reclen;
 107         short           dotdot_namlen;
 108         char            dotdot_name[4];         /* ditto */
 109 };
 110 #endif
 111
 112 #ifdef  __cplusplus
 113 }
 114 #endif
 115
 116 #endif  /* _SYS_FS_UFS_FSDIR_H */