linux/fs/freevxfs/vxfs_dir.h

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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (c) 2000-2001 Christoph Hellwig.
*/
#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 {
__fs16 d_free; /* free space in dirblock */
__fs16 d_nhash; /* no of hash chains */
__fs16 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 {
__fs32 d_ino; /* inode number */
__fs16 d_reclen; /* record length */
__fs16 d_namelen; /* d_name length */
__fs16 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(sbi, dbp) \
((sizeof(short) * fs16_to_cpu(sbi, dbp->d_nhash)) + 4)
#endif /* _VXFS_DIR_H_ */