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 * Minimum and maximum blocksize and sectorsize.
55 * The blocksize upper limit is pretty much arbitrary.
56 * The sectorsize upper limit is due to sizeof(sb_sectsize).
57 */
58#define XFS_MIN_BLOCKSIZE_LOG	9	/* i.e. 512 bytes */
59#define XFS_MAX_BLOCKSIZE_LOG	16	/* i.e. 65536 bytes */
60#define XFS_MIN_BLOCKSIZE	(1 << XFS_MIN_BLOCKSIZE_LOG)
61#define XFS_MAX_BLOCKSIZE	(1 << XFS_MAX_BLOCKSIZE_LOG)
62#define XFS_MIN_SECTORSIZE_LOG	9	/* i.e. 512 bytes */
63#define XFS_MAX_SECTORSIZE_LOG	15	/* i.e. 32768 bytes */
64#define XFS_MIN_SECTORSIZE	(1 << XFS_MIN_SECTORSIZE_LOG)
65#define XFS_MAX_SECTORSIZE	(1 << XFS_MAX_SECTORSIZE_LOG)
66
67/*
68 * Block numbers in the AG:
69 * SB is sector 0, AGF is sector 1, AGI is sector 2, AGFL is sector 3.
70 */
71#define	XFS_BNO_BLOCK(mp)	((xfs_agblock_t)(XFS_AGFL_BLOCK(mp) + 1))
72#define	XFS_CNT_BLOCK(mp)	((xfs_agblock_t)(XFS_BNO_BLOCK(mp) + 1))
73
74/*
75 * Btree block header size depends on a superblock flag.
76 *
77 * (not quite yet, but soon)
78 */
79#define XFS_ALLOC_BLOCK_LEN(mp)	XFS_BTREE_SBLOCK_LEN
80
81/*
82 * Record, key, and pointer address macros for btree blocks.
83 *
84 * (note that some of these may appear unused, but they are used in userspace)
85 */
86#define XFS_ALLOC_REC_ADDR(mp, block, index) \
87	((xfs_alloc_rec_t *) \
88		((char *)(block) + \
89		 XFS_ALLOC_BLOCK_LEN(mp) + \
90		 (((index) - 1) * sizeof(xfs_alloc_rec_t))))
91
92#define XFS_ALLOC_KEY_ADDR(mp, block, index) \
93	((xfs_alloc_key_t *) \
94		((char *)(block) + \
95		 XFS_ALLOC_BLOCK_LEN(mp) + \
96		 ((index) - 1) * sizeof(xfs_alloc_key_t)))
97
98#define XFS_ALLOC_PTR_ADDR(mp, block, index, maxrecs) \
99	((xfs_alloc_ptr_t *) \
100		((char *)(block) + \
101		 XFS_ALLOC_BLOCK_LEN(mp) + \
102		 (maxrecs) * sizeof(xfs_alloc_key_t) + \
103		 ((index) - 1) * sizeof(xfs_alloc_ptr_t)))
104
105extern struct xfs_btree_cur *xfs_allocbt_init_cursor(struct xfs_mount *,
106		struct xfs_trans *, struct xfs_buf *,
107		xfs_agnumber_t, xfs_btnum_t);
108extern int xfs_allocbt_maxrecs(struct xfs_mount *, int, int);
109
110#endif	/* __XFS_ALLOC_BTREE_H__ */
111