1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
|
/*
* Copyright (c) 2000,2005 Silicon Graphics, Inc.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef __XFS_DIR2_DATA_H__
#define __XFS_DIR2_DATA_H__
/*
* Directory format 2, data block structures.
*/
struct xfs_dabuf;
struct xfs_da_args;
struct xfs_inode;
struct xfs_trans;
/*
* Constants.
*/
#define XFS_DIR2_DATA_MAGIC 0x58443244 /* XD2D: for multiblock dirs */
#define XFS_DIR2_DATA_ALIGN_LOG 3 /* i.e., 8 bytes */
#define XFS_DIR2_DATA_ALIGN (1 << XFS_DIR2_DATA_ALIGN_LOG)
#define XFS_DIR2_DATA_FREE_TAG 0xffff
#define XFS_DIR2_DATA_FD_COUNT 3
/*
* Directory address space divided into sections,
* spaces separated by 32gb.
*/
#define XFS_DIR2_SPACE_SIZE (1ULL << (32 + XFS_DIR2_DATA_ALIGN_LOG))
#define XFS_DIR2_DATA_SPACE 0
#define XFS_DIR2_DATA_OFFSET (XFS_DIR2_DATA_SPACE * XFS_DIR2_SPACE_SIZE)
#define XFS_DIR2_DATA_FIRSTDB(mp) \
xfs_dir2_byte_to_db(mp, XFS_DIR2_DATA_OFFSET)
/*
* Offsets of . and .. in data space (always block 0)
*/
#define XFS_DIR2_DATA_DOT_OFFSET \
((xfs_dir2_data_aoff_t)sizeof(xfs_dir2_data_hdr_t))
#define XFS_DIR2_DATA_DOTDOT_OFFSET \
(XFS_DIR2_DATA_DOT_OFFSET + xfs_dir2_data_entsize(1))
#define XFS_DIR2_DATA_FIRST_OFFSET \
(XFS_DIR2_DATA_DOTDOT_OFFSET + xfs_dir2_data_entsize(2))
/*
* Structures.
*/
/*
* Describe a free area in the data block.
* The freespace will be formatted as a xfs_dir2_data_unused_t.
*/
typedef struct xfs_dir2_data_free {
__be16 offset; /* start of freespace */
__be16 length; /* length of freespace */
} xfs_dir2_data_free_t;
/*
* Header for the data blocks.
* Always at the beginning of a directory-sized block.
* The code knows that XFS_DIR2_DATA_FD_COUNT is 3.
*/
typedef struct xfs_dir2_data_hdr {
__be32 magic; /* XFS_DIR2_DATA_MAGIC */
/* or XFS_DIR2_BLOCK_MAGIC */
xfs_dir2_data_free_t bestfree[XFS_DIR2_DATA_FD_COUNT];
} xfs_dir2_data_hdr_t;
/*
* Active entry in a data block. Aligned to 8 bytes.
* Tag appears as the last 2 bytes.
*/
typedef struct xfs_dir2_data_entry {
__be64 inumber; /* inode number */
__u8 namelen; /* name length */
__u8 name[1]; /* name bytes, no null */
/* variable offset */
__be16 tag; /* starting offset of us */
} xfs_dir2_data_entry_t;
/*
* Unused entry in a data block. Aligned to 8 bytes.
* Tag appears as the last 2 bytes.
*/
typedef struct xfs_dir2_data_unused {
__be16 freetag; /* XFS_DIR2_DATA_FREE_TAG */
__be16 length; /* total free length */
/* variable offset */
__be16 tag; /* starting offset of us */
} xfs_dir2_data_unused_t;
typedef union {
xfs_dir2_data_entry_t entry;
xfs_dir2_data_unused_t unused;
} xfs_dir2_data_union_t;
/*
* Generic data block structure, for xfs_db.
*/
typedef struct xfs_dir2_data {
xfs_dir2_data_hdr_t hdr; /* magic XFS_DIR2_DATA_MAGIC */
xfs_dir2_data_union_t u[1];
} xfs_dir2_data_t;
/*
* Macros.
*/
/*
* Size of a data entry.
*/
static inline int xfs_dir2_data_entsize(int n)
{
return (int)roundup(offsetof(xfs_dir2_data_entry_t, name[0]) + (n) + \
(uint)sizeof(xfs_dir2_data_off_t), XFS_DIR2_DATA_ALIGN);
}
/*
* Pointer to an entry's tag word.
*/
static inline __be16 *
xfs_dir2_data_entry_tag_p(xfs_dir2_data_entry_t *dep)
{
return (__be16 *)((char *)dep +
xfs_dir2_data_entsize(dep->namelen) - sizeof(__be16));
}
/*
* Pointer to a freespace's tag word.
*/
static inline __be16 *
xfs_dir2_data_unused_tag_p(xfs_dir2_data_unused_t *dup)
{
return (__be16 *)((char *)dup +
be16_to_cpu(dup->length) - sizeof(__be16));
}
/*
* Function declarations.
*/
#ifdef DEBUG
extern void xfs_dir2_data_check(struct xfs_inode *dp, struct xfs_dabuf *bp);
#else
#define xfs_dir2_data_check(dp,bp)
#endif
extern xfs_dir2_data_free_t *xfs_dir2_data_freefind(xfs_dir2_data_t *d,
xfs_dir2_data_unused_t *dup);
extern xfs_dir2_data_free_t *xfs_dir2_data_freeinsert(xfs_dir2_data_t *d,
xfs_dir2_data_unused_t *dup, int *loghead);
extern void xfs_dir2_data_freescan(struct xfs_mount *mp, xfs_dir2_data_t *d,
int *loghead);
extern int xfs_dir2_data_init(struct xfs_da_args *args, xfs_dir2_db_t blkno,
struct xfs_dabuf **bpp);
extern void xfs_dir2_data_log_entry(struct xfs_trans *tp, struct xfs_dabuf *bp,
xfs_dir2_data_entry_t *dep);
extern void xfs_dir2_data_log_header(struct xfs_trans *tp,
struct xfs_dabuf *bp);
extern void xfs_dir2_data_log_unused(struct xfs_trans *tp, struct xfs_dabuf *bp,
xfs_dir2_data_unused_t *dup);
extern void xfs_dir2_data_make_free(struct xfs_trans *tp, struct xfs_dabuf *bp,
xfs_dir2_data_aoff_t offset,
xfs_dir2_data_aoff_t len, int *needlogp,
int *needscanp);
extern void xfs_dir2_data_use_free(struct xfs_trans *tp, struct xfs_dabuf *bp,
xfs_dir2_data_unused_t *dup,
xfs_dir2_data_aoff_t offset,
xfs_dir2_data_aoff_t len, int *needlogp,
int *needscanp);
#endif /* __XFS_DIR2_DATA_H__ */
|
