tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Copyright (c) 2000,2005 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_ALLOC_BTREE_H__
19#define __XFS_ALLOC_BTREE_H__
20
21/*
22 * Freespace on-disk structures
23 */
24
25struct xfs_buf;
26struct xfs_btree_cur;
27struct xfs_mount;
28
29/*
30 * There are two on-disk btrees, one sorted by blockno and one sorted
31 * by blockcount and blockno. All blocks look the same to make the code
32 * simpler; if we have time later, we'll make the optimizations.
33 */
34#define XFS_ABTB_MAGIC 0x41425442 /* 'ABTB' for bno tree */
35#define XFS_ABTC_MAGIC 0x41425443 /* 'ABTC' for cnt tree */
36
37/*
38 * Data record/key structure
39 */
40typedef struct xfs_alloc_rec {
41 __be32 ar_startblock; /* starting block number */
42 __be32 ar_blockcount; /* count of free blocks */
43} xfs_alloc_rec_t, xfs_alloc_key_t;
44
45typedef struct xfs_alloc_rec_incore {
46 xfs_agblock_t ar_startblock; /* starting block number */
47 xfs_extlen_t ar_blockcount; /* count of free blocks */
48} xfs_alloc_rec_incore_t;
49
50/* btree pointer type */
51typedef __be32 xfs_alloc_ptr_t;
52
53/*
54 * Block numbers in the AG:
55 * SB is sector 0, AGF is sector 1, AGI is sector 2, AGFL is sector 3.
56 */
57#define XFS_BNO_BLOCK(mp) ((xfs_agblock_t)(XFS_AGFL_BLOCK(mp) + 1))
58#define XFS_CNT_BLOCK(mp) ((xfs_agblock_t)(XFS_BNO_BLOCK(mp) + 1))
59
60/*
61 * Btree block header size depends on a superblock flag.
62 *
63 * (not quite yet, but soon)
64 */
65#define XFS_ALLOC_BLOCK_LEN(mp) XFS_BTREE_SBLOCK_LEN
66
67/*
68 * Record, key, and pointer address macros for btree blocks.
69 *
70 * (note that some of these may appear unused, but they are used in userspace)
71 */
72#define XFS_ALLOC_REC_ADDR(mp, block, index) \
73 ((xfs_alloc_rec_t *) \
74 ((char *)(block) + \
75 XFS_ALLOC_BLOCK_LEN(mp) + \
76 (((index) - 1) * sizeof(xfs_alloc_rec_t))))
77
78#define XFS_ALLOC_KEY_ADDR(mp, block, index) \
79 ((xfs_alloc_key_t *) \
80 ((char *)(block) + \
81 XFS_ALLOC_BLOCK_LEN(mp) + \
82 ((index) - 1) * sizeof(xfs_alloc_key_t)))
83
84#define XFS_ALLOC_PTR_ADDR(mp, block, index, maxrecs) \
85 ((xfs_alloc_ptr_t *) \
86 ((char *)(block) + \
87 XFS_ALLOC_BLOCK_LEN(mp) + \
88 (maxrecs) * sizeof(xfs_alloc_key_t) + \
89 ((index) - 1) * sizeof(xfs_alloc_ptr_t)))
90
91extern struct xfs_btree_cur *xfs_allocbt_init_cursor(struct xfs_mount *,
92 struct xfs_trans *, struct xfs_buf *,
93 xfs_agnumber_t, xfs_btnum_t);
94extern int xfs_allocbt_maxrecs(struct xfs_mount *, int, int);
95
96extern const struct xfs_buf_ops xfs_allocbt_buf_ops;
97
98#endif /* __XFS_ALLOC_BTREE_H__ */