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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Nathan Scott7b718762005-11-02 14:58:39 +11002 * Copyright (c) 2000,2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 *
Nathan Scott7b718762005-11-02 14:58:39 +11005 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 * published by the Free Software Foundation.
8 *
Nathan Scott7b718762005-11-02 14:58:39 +11009 * 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.
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 *
Nathan Scott7b718762005-11-02 14:58:39 +110014 * 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070017 */
18#ifndef __XFS_DIR2_DATA_H__
19#define __XFS_DIR2_DATA_H__
20
21/*
22 * Directory format 2, data block structures.
23 */
24
25struct xfs_dabuf;
26struct xfs_da_args;
27struct xfs_inode;
28struct xfs_trans;
29
30/*
31 * Constants.
32 */
33#define XFS_DIR2_DATA_MAGIC 0x58443244 /* XD2D: for multiblock dirs */
34#define XFS_DIR2_DATA_ALIGN_LOG 3 /* i.e., 8 bytes */
35#define XFS_DIR2_DATA_ALIGN (1 << XFS_DIR2_DATA_ALIGN_LOG)
36#define XFS_DIR2_DATA_FREE_TAG 0xffff
37#define XFS_DIR2_DATA_FD_COUNT 3
38
39/*
40 * Directory address space divided into sections,
41 * spaces separated by 32gb.
42 */
43#define XFS_DIR2_SPACE_SIZE (1ULL << (32 + XFS_DIR2_DATA_ALIGN_LOG))
44#define XFS_DIR2_DATA_SPACE 0
45#define XFS_DIR2_DATA_OFFSET (XFS_DIR2_DATA_SPACE * XFS_DIR2_SPACE_SIZE)
46#define XFS_DIR2_DATA_FIRSTDB(mp) \
47 XFS_DIR2_BYTE_TO_DB(mp, XFS_DIR2_DATA_OFFSET)
48
49/*
50 * Offsets of . and .. in data space (always block 0)
51 */
52#define XFS_DIR2_DATA_DOT_OFFSET \
53 ((xfs_dir2_data_aoff_t)sizeof(xfs_dir2_data_hdr_t))
54#define XFS_DIR2_DATA_DOTDOT_OFFSET \
55 (XFS_DIR2_DATA_DOT_OFFSET + XFS_DIR2_DATA_ENTSIZE(1))
56#define XFS_DIR2_DATA_FIRST_OFFSET \
57 (XFS_DIR2_DATA_DOTDOT_OFFSET + XFS_DIR2_DATA_ENTSIZE(2))
58
59/*
60 * Structures.
61 */
62
63/*
64 * Describe a free area in the data block.
65 * The freespace will be formatted as a xfs_dir2_data_unused_t.
66 */
67typedef struct xfs_dir2_data_free {
Nathan Scott70e73f52006-03-17 17:26:52 +110068 __be16 offset; /* start of freespace */
69 __be16 length; /* length of freespace */
Linus Torvalds1da177e2005-04-16 15:20:36 -070070} xfs_dir2_data_free_t;
71
72/*
73 * Header for the data blocks.
74 * Always at the beginning of a directory-sized block.
75 * The code knows that XFS_DIR2_DATA_FD_COUNT is 3.
76 */
77typedef struct xfs_dir2_data_hdr {
Nathan Scott70e73f52006-03-17 17:26:52 +110078 __be32 magic; /* XFS_DIR2_DATA_MAGIC */
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 /* or XFS_DIR2_BLOCK_MAGIC */
80 xfs_dir2_data_free_t bestfree[XFS_DIR2_DATA_FD_COUNT];
81} xfs_dir2_data_hdr_t;
82
83/*
84 * Active entry in a data block. Aligned to 8 bytes.
85 * Tag appears as the last 2 bytes.
86 */
87typedef struct xfs_dir2_data_entry {
Christoph Hellwigff9901c2006-06-09 14:48:37 +100088 __be64 inumber; /* inode number */
89 __u8 namelen; /* name length */
90 __u8 name[1]; /* name bytes, no null */
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 /* variable offset */
Christoph Hellwigff9901c2006-06-09 14:48:37 +100092 __be16 tag; /* starting offset of us */
Linus Torvalds1da177e2005-04-16 15:20:36 -070093} xfs_dir2_data_entry_t;
94
95/*
96 * Unused entry in a data block. Aligned to 8 bytes.
97 * Tag appears as the last 2 bytes.
98 */
99typedef struct xfs_dir2_data_unused {
Nathan Scottad354eb2006-03-17 17:27:37 +1100100 __be16 freetag; /* XFS_DIR2_DATA_FREE_TAG */
101 __be16 length; /* total free length */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 /* variable offset */
Nathan Scottad354eb2006-03-17 17:27:37 +1100103 __be16 tag; /* starting offset of us */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104} xfs_dir2_data_unused_t;
105
106typedef union {
107 xfs_dir2_data_entry_t entry;
108 xfs_dir2_data_unused_t unused;
109} xfs_dir2_data_union_t;
110
111/*
112 * Generic data block structure, for xfs_db.
113 */
114typedef struct xfs_dir2_data {
115 xfs_dir2_data_hdr_t hdr; /* magic XFS_DIR2_DATA_MAGIC */
116 xfs_dir2_data_union_t u[1];
117} xfs_dir2_data_t;
118
119/*
120 * Macros.
121 */
122
123/*
124 * Size of a data entry.
125 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126#define XFS_DIR2_DATA_ENTSIZE(n) xfs_dir2_data_entsize(n)
Nathan Scotta844f452005-11-02 14:38:42 +1100127static inline int xfs_dir2_data_entsize(int n)
128{
129 return (int)roundup(offsetof(xfs_dir2_data_entry_t, name[0]) + (n) + \
130 (uint)sizeof(xfs_dir2_data_off_t), XFS_DIR2_DATA_ALIGN);
131}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132
133/*
134 * Pointer to an entry's tag word.
135 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136#define XFS_DIR2_DATA_ENTRY_TAG_P(dep) xfs_dir2_data_entry_tag_p(dep)
Nathan Scott3d693c62006-03-17 17:28:27 +1100137static inline __be16 *
Nathan Scotta844f452005-11-02 14:38:42 +1100138xfs_dir2_data_entry_tag_p(xfs_dir2_data_entry_t *dep)
139{
Nathan Scott3d693c62006-03-17 17:28:27 +1100140 return (__be16 *)((char *)dep +
141 XFS_DIR2_DATA_ENTSIZE(dep->namelen) - sizeof(__be16));
Nathan Scotta844f452005-11-02 14:38:42 +1100142}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143
144/*
145 * Pointer to a freespace's tag word.
146 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147#define XFS_DIR2_DATA_UNUSED_TAG_P(dup) \
148 xfs_dir2_data_unused_tag_p(dup)
Nathan Scott1fba9f72006-03-17 17:27:47 +1100149static inline __be16 *
Nathan Scotta844f452005-11-02 14:38:42 +1100150xfs_dir2_data_unused_tag_p(xfs_dir2_data_unused_t *dup)
151{
Nathan Scott1fba9f72006-03-17 17:27:47 +1100152 return (__be16 *)((char *)dup +
153 be16_to_cpu(dup->length) - sizeof(__be16));
Nathan Scotta844f452005-11-02 14:38:42 +1100154}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155
156/*
157 * Function declarations.
158 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159#ifdef DEBUG
Nathan Scotta844f452005-11-02 14:38:42 +1100160extern void xfs_dir2_data_check(struct xfs_inode *dp, struct xfs_dabuf *bp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161#else
162#define xfs_dir2_data_check(dp,bp)
163#endif
Nathan Scotta844f452005-11-02 14:38:42 +1100164extern xfs_dir2_data_free_t *xfs_dir2_data_freefind(xfs_dir2_data_t *d,
165 xfs_dir2_data_unused_t *dup);
166extern xfs_dir2_data_free_t *xfs_dir2_data_freeinsert(xfs_dir2_data_t *d,
167 xfs_dir2_data_unused_t *dup, int *loghead);
168extern void xfs_dir2_data_freescan(struct xfs_mount *mp, xfs_dir2_data_t *d,
169 int *loghead, char *aendp);
170extern int xfs_dir2_data_init(struct xfs_da_args *args, xfs_dir2_db_t blkno,
171 struct xfs_dabuf **bpp);
172extern void xfs_dir2_data_log_entry(struct xfs_trans *tp, struct xfs_dabuf *bp,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 xfs_dir2_data_entry_t *dep);
Nathan Scotta844f452005-11-02 14:38:42 +1100174extern void xfs_dir2_data_log_header(struct xfs_trans *tp,
175 struct xfs_dabuf *bp);
176extern void xfs_dir2_data_log_unused(struct xfs_trans *tp, struct xfs_dabuf *bp,
177 xfs_dir2_data_unused_t *dup);
178extern void xfs_dir2_data_make_free(struct xfs_trans *tp, struct xfs_dabuf *bp,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 xfs_dir2_data_aoff_t offset,
180 xfs_dir2_data_aoff_t len, int *needlogp,
181 int *needscanp);
Nathan Scotta844f452005-11-02 14:38:42 +1100182extern void xfs_dir2_data_use_free(struct xfs_trans *tp, struct xfs_dabuf *bp,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 xfs_dir2_data_unused_t *dup,
184 xfs_dir2_data_aoff_t offset,
185 xfs_dir2_data_aoff_t len, int *needlogp,
186 int *needscanp);
187
188#endif /* __XFS_DIR2_DATA_H__ */