vxfs_dir.h
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/*
* 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_ */