1/*
2 * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17 */
18#ifndef __XFS_DIR2_SF_H__
19#define	__XFS_DIR2_SF_H__
20
21/*
22 * Directory layout when stored internal to an inode.
23 *
24 * Small directories are packed as tightly as possible so as to
25 * fit into the literal area of the inode.
26 */
27
28struct uio;
29struct xfs_dabuf;
30struct xfs_da_args;
31struct xfs_dir2_block;
32struct xfs_inode;
33struct xfs_mount;
34struct xfs_trans;
35
36/*
37 * Inode number stored as 8 8-bit values.
38 */
39typedef	struct { __uint8_t i[8]; } xfs_dir2_ino8_t;
40
41/*
42 * Inode number stored as 4 8-bit values.
43 * Works a lot of the time, when all the inode numbers in a directory
44 * fit in 32 bits.
45 */
46typedef struct { __uint8_t i[4]; } xfs_dir2_ino4_t;
47
48typedef union {
49	xfs_dir2_ino8_t	i8;
50	xfs_dir2_ino4_t	i4;
51} xfs_dir2_inou_t;
52#define	XFS_DIR2_MAX_SHORT_INUM	((xfs_ino_t)0xffffffffULL)
53
54/*
55 * Normalized offset (in a data block) of the entry, really xfs_dir2_data_off_t.
56 * Only need 16 bits, this is the byte offset into the single block form.
57 */
58typedef struct { __uint8_t i[2]; } __arch_pack xfs_dir2_sf_off_t;
59
60/*
61 * The parent directory has a dedicated field, and the self-pointer must
62 * be calculated on the fly.
63 *
64 * Entries are packed toward the top as tightly as possible.  The header
65 * and the elements must be memcpy'd out into a work area to get correct
66 * alignment for the inode number fields.
67 */
68typedef struct xfs_dir2_sf_hdr {
69	__uint8_t		count;		/* count of entries */
70	__uint8_t		i8count;	/* count of 8-byte inode #s */
71	xfs_dir2_inou_t		parent;		/* parent dir inode number */
72} __arch_pack xfs_dir2_sf_hdr_t;
73
74typedef struct xfs_dir2_sf_entry {
75	__uint8_t		namelen;	/* actual name length */
76	xfs_dir2_sf_off_t	offset;		/* saved offset */
77	__uint8_t		name[1];	/* name, variable size */
78	xfs_dir2_inou_t		inumber;	/* inode number, var. offset */
79} __arch_pack xfs_dir2_sf_entry_t;
80
81typedef struct xfs_dir2_sf {
82	xfs_dir2_sf_hdr_t	hdr;		/* shortform header */
83	xfs_dir2_sf_entry_t	list[1];	/* shortform entries */
84} xfs_dir2_sf_t;
85
86static inline int xfs_dir2_sf_hdr_size(int i8count)
87{
88	return ((uint)sizeof(xfs_dir2_sf_hdr_t) - \
89		((i8count) == 0) * \
90		((uint)sizeof(xfs_dir2_ino8_t) - (uint)sizeof(xfs_dir2_ino4_t)));
91}
92
93static inline xfs_dir2_inou_t *xfs_dir2_sf_inumberp(xfs_dir2_sf_entry_t *sfep)
94{
95	return (xfs_dir2_inou_t *)&(sfep)->name[(sfep)->namelen];
96}
97
98static inline xfs_intino_t
99xfs_dir2_sf_get_inumber(xfs_dir2_sf_t *sfp, xfs_dir2_inou_t *from)
100{
101	return ((sfp)->hdr.i8count == 0 ? \
102		(xfs_intino_t)XFS_GET_DIR_INO4((from)->i4) : \
103		(xfs_intino_t)XFS_GET_DIR_INO8((from)->i8));
104}
105
106static inline void xfs_dir2_sf_put_inumber(xfs_dir2_sf_t *sfp, xfs_ino_t *from,
107						xfs_dir2_inou_t *to)
108{
109	if ((sfp)->hdr.i8count == 0)
110		XFS_PUT_DIR_INO4(*(from), (to)->i4);
111	else
112		XFS_PUT_DIR_INO8(*(from), (to)->i8);
113}
114
115static inline xfs_dir2_data_aoff_t
116xfs_dir2_sf_get_offset(xfs_dir2_sf_entry_t *sfep)
117{
118	return INT_GET_UNALIGNED_16_BE(&(sfep)->offset.i);
119}
120
121static inline void
122xfs_dir2_sf_put_offset(xfs_dir2_sf_entry_t *sfep, xfs_dir2_data_aoff_t off)
123{
124	INT_SET_UNALIGNED_16_BE(&(sfep)->offset.i, off);
125}
126
127static inline int xfs_dir2_sf_entsize_byname(xfs_dir2_sf_t *sfp, int len)
128{
129	return ((uint)sizeof(xfs_dir2_sf_entry_t) - 1 + (len) - \
130		((sfp)->hdr.i8count == 0) * \
131		((uint)sizeof(xfs_dir2_ino8_t) - (uint)sizeof(xfs_dir2_ino4_t)));
132}
133
134static inline int
135xfs_dir2_sf_entsize_byentry(xfs_dir2_sf_t *sfp, xfs_dir2_sf_entry_t *sfep)
136{
137	return ((uint)sizeof(xfs_dir2_sf_entry_t) - 1 + (sfep)->namelen - \
138		((sfp)->hdr.i8count == 0) * \
139		((uint)sizeof(xfs_dir2_ino8_t) - (uint)sizeof(xfs_dir2_ino4_t)));
140}
141
142static inline xfs_dir2_sf_entry_t *xfs_dir2_sf_firstentry(xfs_dir2_sf_t *sfp)
143{
144	return ((xfs_dir2_sf_entry_t *) \
145		((char *)(sfp) + xfs_dir2_sf_hdr_size(sfp->hdr.i8count)));
146}
147
148static inline xfs_dir2_sf_entry_t *
149xfs_dir2_sf_nextentry(xfs_dir2_sf_t *sfp, xfs_dir2_sf_entry_t *sfep)
150{
151	return ((xfs_dir2_sf_entry_t *) \
152		((char *)(sfep) + xfs_dir2_sf_entsize_byentry(sfp,sfep)));
153}
154
155/*
156 * Functions.
157 */
158extern int xfs_dir2_block_sfsize(struct xfs_inode *dp,
159				 struct xfs_dir2_block *block,
160				 xfs_dir2_sf_hdr_t *sfhp);
161extern int xfs_dir2_block_to_sf(struct xfs_da_args *args, struct xfs_dabuf *bp,
162				int size, xfs_dir2_sf_hdr_t *sfhp);
163extern int xfs_dir2_sf_addname(struct xfs_da_args *args);
164extern int xfs_dir2_sf_create(struct xfs_da_args *args, xfs_ino_t pino);
165extern int xfs_dir2_sf_getdents(struct xfs_inode *dp, void *dirent,
166				xfs_off_t *offset, filldir_t filldir);
167extern int xfs_dir2_sf_lookup(struct xfs_da_args *args);
168extern int xfs_dir2_sf_removename(struct xfs_da_args *args);
169extern int xfs_dir2_sf_replace(struct xfs_da_args *args);
170
171#endif	/* __XFS_DIR2_SF_H__ */
172