1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright (c) 2000-2001 Christoph Hellwig.
4 */
5#ifndef _VXFS_DIR_H_
6#define _VXFS_DIR_H_
7
8/*
9 * Veritas filesystem driver - directory structure.
10 *
11 * This file contains the definition of the vxfs directory format.
12 */
13
14
15/*
16 * VxFS directory block header.
17 *
18 * This entry is the head of every filesystem block in a directory.
19 * It is used for free space management and additionally includes
20 * a hash for speeding up directory search (lookup).
21 *
22 * The hash may be empty and in fact we do not use it all in the
23 * Linux driver for now.
24 */
25struct vxfs_dirblk {
26	__fs16		d_free;		/* free space in dirblock */
27	__fs16		d_nhash;	/* no of hash chains */
28	__fs16		d_hash[1];	/* hash chain */
29};
30
31/*
32 * VXFS_NAMELEN is the maximum length of the d_name field
33 *	of an VxFS directory entry.
34 */
35#define VXFS_NAMELEN	256
36
37/*
38 * VxFS directory entry.
39 */
40struct vxfs_direct {
41	__fs32		d_ino;			/* inode number */
42	__fs16		d_reclen;		/* record length */
43	__fs16		d_namelen;		/* d_name length */
44	__fs16		d_hashnext;		/* next hash entry */
45	char		d_name[VXFS_NAMELEN];	/* name */
46};
47
48/*
49 * VXFS_DIRPAD defines the directory entry boundaries, is _must_ be
50 *	a multiple of four.
51 * VXFS_NAMEMIN is the length of a directory entry with a NULL d_name.
52 * VXFS_DIRROUND is an internal macros that rounds a length to a value
53 *	usable for directory sizes.
54 * VXFS_DIRLEN calculates the directory entry size for an entry with
55 *	a d_name with size len.
56 */
57#define VXFS_DIRPAD		4
58#define VXFS_NAMEMIN		offsetof(struct vxfs_direct, d_name)
59#define VXFS_DIRROUND(len)	((VXFS_DIRPAD + (len) - 1) & ~(VXFS_DIRPAD -1))
60#define VXFS_DIRLEN(len)	(VXFS_DIRROUND(VXFS_NAMEMIN + (len)))
61
62/*
63 * VXFS_DIRBLKOV is the overhead of a specific dirblock.
64 */
65#define VXFS_DIRBLKOV(sbi, dbp)	\
66	((sizeof(short) * fs16_to_cpu(sbi, dbp->d_nhash)) + 4)
67
68#endif /* _VXFS_DIR_H_ */
69