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_btree_sblock;
28struct xfs_mount;
29
30/*
31 * There are two on-disk btrees, one sorted by blockno and one sorted
32 * by blockcount and blockno.  All blocks look the same to make the code
33 * simpler; if we have time later, we'll make the optimizations.
34 */
35#define	XFS_ABTB_MAGIC	0x41425442	/* 'ABTB' for bno tree */
36#define	XFS_ABTC_MAGIC	0x41425443	/* 'ABTC' for cnt tree */
37
38/*
39 * Data record/key structure
40 */
41typedef struct xfs_alloc_rec {
42	__be32		ar_startblock;	/* starting block number */
43	__be32		ar_blockcount;	/* count of free blocks */
44} xfs_alloc_rec_t, xfs_alloc_key_t;
45
46typedef struct xfs_alloc_rec_incore {
47	xfs_agblock_t	ar_startblock;	/* starting block number */
48	xfs_extlen_t	ar_blockcount;	/* count of free blocks */
49} xfs_alloc_rec_incore_t;
50
51/* btree pointer type */
52typedef __be32 xfs_alloc_ptr_t;
53/* btree block header type */
54typedef	struct xfs_btree_sblock xfs_alloc_block_t;
55
56#define	XFS_BUF_TO_ALLOC_BLOCK(bp)	((xfs_alloc_block_t *)XFS_BUF_PTR(bp))
57
58/*
59 * Real block structures have a size equal to the disk block size.
60 */
61#define	XFS_ALLOC_BLOCK_MAXRECS(lev,cur) ((cur)->bc_mp->m_alloc_mxr[lev != 0])
62#define	XFS_ALLOC_BLOCK_MINRECS(lev,cur) ((cur)->bc_mp->m_alloc_mnr[lev != 0])
63
64/*
65 * Minimum and maximum blocksize and sectorsize.
66 * The blocksize upper limit is pretty much arbitrary.
67 * The sectorsize upper limit is due to sizeof(sb_sectsize).
68 */
69#define XFS_MIN_BLOCKSIZE_LOG	9	/* i.e. 512 bytes */
70#define XFS_MAX_BLOCKSIZE_LOG	16	/* i.e. 65536 bytes */
71#define XFS_MIN_BLOCKSIZE	(1 << XFS_MIN_BLOCKSIZE_LOG)
72#define XFS_MAX_BLOCKSIZE	(1 << XFS_MAX_BLOCKSIZE_LOG)
73#define XFS_MIN_SECTORSIZE_LOG	9	/* i.e. 512 bytes */
74#define XFS_MAX_SECTORSIZE_LOG	15	/* i.e. 32768 bytes */
75#define XFS_MIN_SECTORSIZE	(1 << XFS_MIN_SECTORSIZE_LOG)
76#define XFS_MAX_SECTORSIZE	(1 << XFS_MAX_SECTORSIZE_LOG)
77
78/*
79 * Block numbers in the AG:
80 * SB is sector 0, AGF is sector 1, AGI is sector 2, AGFL is sector 3.
81 */
82#define	XFS_BNO_BLOCK(mp)	((xfs_agblock_t)(XFS_AGFL_BLOCK(mp) + 1))
83#define	XFS_CNT_BLOCK(mp)	((xfs_agblock_t)(XFS_BNO_BLOCK(mp) + 1))
84
85/*
86 * Record, key, and pointer address macros for btree blocks.
87 */
88#define	XFS_ALLOC_REC_ADDR(bb,i,cur)	\
89	XFS_BTREE_REC_ADDR(xfs_alloc, bb, i)
90
91#define	XFS_ALLOC_KEY_ADDR(bb,i,cur)	\
92	XFS_BTREE_KEY_ADDR(xfs_alloc, bb, i)
93
94#define	XFS_ALLOC_PTR_ADDR(bb,i,cur)	\
95	XFS_BTREE_PTR_ADDR(xfs_alloc, bb, i, XFS_ALLOC_BLOCK_MAXRECS(1, cur))
96
97/*
98 * Decrement cursor by one record at the level.
99 * For nonzero levels the leaf-ward information is untouched.
100 */
101extern int xfs_alloc_decrement(struct xfs_btree_cur *cur, int level, int *stat);
102
103/*
104 * Delete the record pointed to by cur.
105 * The cursor refers to the place where the record was (could be inserted)
106 * when the operation returns.
107 */
108extern int xfs_alloc_delete(struct xfs_btree_cur *cur, int *stat);
109
110/*
111 * Get the data from the pointed-to record.
112 */
113extern int xfs_alloc_get_rec(struct xfs_btree_cur *cur,	xfs_agblock_t *bno,
114				xfs_extlen_t *len, int *stat);
115
116/*
117 * Increment cursor by one record at the level.
118 * For nonzero levels the leaf-ward information is untouched.
119 */
120extern int xfs_alloc_increment(struct xfs_btree_cur *cur, int level, int *stat);
121
122/*
123 * Insert the current record at the point referenced by cur.
124 * The cursor may be inconsistent on return if splits have been done.
125 */
126extern int xfs_alloc_insert(struct xfs_btree_cur *cur, int *stat);
127
128/*
129 * Lookup the record equal to [bno, len] in the btree given by cur.
130 */
131extern int xfs_alloc_lookup_eq(struct xfs_btree_cur *cur, xfs_agblock_t bno,
132				xfs_extlen_t len, int *stat);
133
134/*
135 * Lookup the first record greater than or equal to [bno, len]
136 * in the btree given by cur.
137 */
138extern int xfs_alloc_lookup_ge(struct xfs_btree_cur *cur, xfs_agblock_t bno,
139				xfs_extlen_t len, int *stat);
140
141/*
142 * Lookup the first record less than or equal to [bno, len]
143 * in the btree given by cur.
144 */
145extern int xfs_alloc_lookup_le(struct xfs_btree_cur *cur, xfs_agblock_t bno,
146				xfs_extlen_t len, int *stat);
147
148/*
149 * Update the record referred to by cur, to the value given by [bno, len].
150 * This either works (return 0) or gets an EFSCORRUPTED error.
151 */
152extern int xfs_alloc_update(struct xfs_btree_cur *cur, xfs_agblock_t bno,
153				xfs_extlen_t len);
154
155#endif	/* __XFS_ALLOC_BTREE_H__ */
156