/*
 * @DEC_COPYRIGHT@
 */
/*
 * HISTORY
 * $Log:	dir.h,v $
 * Revision 4.2  91/09/19  23:05:10  devbld
 * Adding ODE Headers
 * 
 * $EndLog$
 */
/*	
 *	@(#)$RCSfile: dir.h,v $ $Revision: 4.2 $ (DEC) $Date: 91/09/19 23:05:10 $
 */ 
/*
 */
/*
 * (c) Copyright 1990, OPEN SOFTWARE FOUNDATION, INC.
 * ALL RIGHTS RESERVED
 */
/* 
 * Mach Operating System
 * Copyright (c) 1989 Carnegie-Mellon University
 * Copyright (c) 1988 Carnegie-Mellon University
 * Copyright (c) 1987 Carnegie-Mellon University
 * All rights reserved.  The CMU software License Agreement specifies
 * the terms and conditions for use and redistribution.
 */
/*
 * OSF/1 Release 1.0
 */
/*
 * Copyright (c) 1982, 1986, 1989 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *

 */

#ifndef	_UFS_DIR_H_
#define _UFS_DIR_H_

#include <sys/types.h>
#include <sys/param.h>		/* for DEV_BSIZE */

/*
 * A directory consists of some number of blocks of DIRBLKSIZ
 * bytes, where DIRBLKSIZ is chosen such that it can be transferred
 * to disk in a single atomic operation (e.g. 512 bytes on most machines).
 *
 * Each DIRBLKSIZ byte block contains some number of directory entry
 * structures, which are of variable length.  Each directory entry has
 * a struct direct at the front of it, containing its inode number,
 * the length of the entry, and the length of the name contained in
 * the entry.  These are followed by the name padded to a 4 byte boundary
 * with null bytes.  All names are guaranteed null terminated.
 * The maximum length of a name in a directory is MAXNAMLEN.
 *
 * The macro DIRSIZ(dp) gives the amount of space required to represent
 * a directory entry.  Free space in a directory is represented by
 * entries which have dp->d_reclen > DIRSIZ(dp).  All DIRBLKSIZ bytes
 * in a directory block are claimed by the directory entries.  This
 * usually results in the last entry in a directory having a large
 * dp->d_reclen.  When entries are deleted from a directory, the
 * space is returned to the previous entry in the same directory
 * block by increasing its dp->d_reclen.  If the first entry of
 * a directory block is free, then its dp->d_ino is set to 0.
 * Entries other than the first in a directory do not normally have
 * dp->d_ino set to 0.
 */
#define DIRBLKSIZ	DEV_BSIZE

#ifdef _KERNEL
/*
 * Template for manipulating directories.
 * Should use struct direct's, but the name field
 * is MAXNAMLEN - 1, and this just won't do.
 */
struct dirtemplate {
	u_long	dot_ino;
	short	dot_reclen;
	short	dot_namlen;
	char	dot_name[4];		/* must be multiple of 4 */
	u_long	dotdot_ino;
	short	dotdot_reclen;
	short	dotdot_namlen;
	char	dotdot_name[4];		/* ditto */
};
#endif /* _KERNEL */

#include <dirent.h>
#endif	/* _UFS_DIR_H_ */
