/*
   * Copyright (c) 2000-2001 Christoph Hellwig.
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions, and the following disclaimer,
   *    without modification.
   * 2. The name of the author may not be used to endorse or promote products
   *    derived from this software without specific prior written permission.
   *
   * Alternatively, this software may be distributed under the terms of the
   * GNU General Public License ("GPL").
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
   * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   *
   */
  #ifndef _VXFS_DIR_H_
  #define _VXFS_DIR_H_
  
  /*
   * Veritas filesystem driver - directory structure.
   *
   * This file contains the definition of the vxfs directory format.
   */
  
  
  /*
   * VxFS directory block header.
   *
   * This entry is the head of every filesystem block in a directory.
   * It is used for free space management and additionally includes
   * a hash for speeding up directory search (lookup).
   *
   * The hash may be empty and in fact we do not use it all in the
   * Linux driver for now.
   */
  struct vxfs_dirblk {
  	u_int16_t	d_free;		/* free space in dirblock */
  	u_int16_t	d_nhash;	/* no of hash chains */
  	u_int16_t	d_hash[1];	/* hash chain */
  };
  
  /*
   * VXFS_NAMELEN is the maximum length of the d_name field
   *	of an VxFS directory entry.
   */
  #define VXFS_NAMELEN	256
  
  /*
   * VxFS directory entry.
   */
  struct vxfs_direct {
  	vx_ino_t	d_ino;			/* inode number */
  	u_int16_t	d_reclen;		/* record length */
  	u_int16_t	d_namelen;		/* d_name length */
  	u_int16_t	d_hashnext;		/* next hash entry */
  	char		d_name[VXFS_NAMELEN];	/* name */
  };
  
  /*
   * VXFS_DIRPAD defines the directory entry boundaries, is _must_ be
   *	a multiple of four.
   * VXFS_NAMEMIN is the length of a directory entry with a NULL d_name.
   * VXFS_DIRROUND is an internal macros that rounds a length to a value
   *	usable for directory sizes.
   * VXFS_DIRLEN calculates the directory entry size for an entry with
   *	a d_name with size len.
   */
  #define VXFS_DIRPAD		4
  #define VXFS_NAMEMIN		offsetof(struct vxfs_direct, d_name)
  #define VXFS_DIRROUND(len)	((VXFS_DIRPAD + (len) - 1) & ~(VXFS_DIRPAD -1))
  #define VXFS_DIRLEN(len)	(VXFS_DIRROUND(VXFS_NAMEMIN + (len)))
  
  /*
   * VXFS_DIRBLKOV is the overhead of a specific dirblock.
   */
  #define VXFS_DIRBLKOV(dbp)	((sizeof(short) * dbp->d_nhash) + 4)
  
  #endif /* _VXFS_DIR_H_ */