2 * Copyright (c) 2000,2005 Silicon Graphics, Inc.
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.
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.
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
18 #ifndef __XFS_ALLOC_BTREE_H__
19 #define __XFS_ALLOC_BTREE_H__
22 * Freespace on-disk structures
27 struct xfs_btree_sblock;
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.
35 #define XFS_ABTB_MAGIC 0x41425442 /* 'ABTB' for bno tree */
36 #define XFS_ABTC_MAGIC 0x41425443 /* 'ABTC' for cnt tree */
39 * Data record/key structure
41 typedef 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;
46 typedef 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;
51 /* btree pointer type */
52 typedef __be32 xfs_alloc_ptr_t;
53 /* btree block header type */
54 typedef struct xfs_btree_sblock xfs_alloc_block_t;
56 #define XFS_BUF_TO_ALLOC_BLOCK(bp) ((xfs_alloc_block_t *)XFS_BUF_PTR(bp))
59 * Minimum and maximum blocksize and sectorsize.
60 * The blocksize upper limit is pretty much arbitrary.
61 * The sectorsize upper limit is due to sizeof(sb_sectsize).
63 #define XFS_MIN_BLOCKSIZE_LOG 9 /* i.e. 512 bytes */
64 #define XFS_MAX_BLOCKSIZE_LOG 16 /* i.e. 65536 bytes */
65 #define XFS_MIN_BLOCKSIZE (1 << XFS_MIN_BLOCKSIZE_LOG)
66 #define XFS_MAX_BLOCKSIZE (1 << XFS_MAX_BLOCKSIZE_LOG)
67 #define XFS_MIN_SECTORSIZE_LOG 9 /* i.e. 512 bytes */
68 #define XFS_MAX_SECTORSIZE_LOG 15 /* i.e. 32768 bytes */
69 #define XFS_MIN_SECTORSIZE (1 << XFS_MIN_SECTORSIZE_LOG)
70 #define XFS_MAX_SECTORSIZE (1 << XFS_MAX_SECTORSIZE_LOG)
73 * Block numbers in the AG:
74 * SB is sector 0, AGF is sector 1, AGI is sector 2, AGFL is sector 3.
76 #define XFS_BNO_BLOCK(mp) ((xfs_agblock_t)(XFS_AGFL_BLOCK(mp) + 1))
77 #define XFS_CNT_BLOCK(mp) ((xfs_agblock_t)(XFS_BNO_BLOCK(mp) + 1))
80 * Record, key, and pointer address macros for btree blocks.
82 * (note that some of these may appear unused, but they are used in userspace)
84 #define XFS_ALLOC_REC_ADDR(mp, block, index) \
85 ((xfs_alloc_rec_t *) \
87 sizeof(struct xfs_btree_sblock) + \
88 (((index) - 1) * sizeof(xfs_alloc_rec_t))))
90 #define XFS_ALLOC_KEY_ADDR(mp, block, index) \
91 ((xfs_alloc_key_t *) \
93 sizeof(struct xfs_btree_sblock) + \
94 ((index) - 1) * sizeof(xfs_alloc_key_t)))
96 #define XFS_ALLOC_PTR_ADDR(mp, block, index, maxrecs) \
97 ((xfs_alloc_ptr_t *) \
99 sizeof(struct xfs_btree_sblock) + \
100 (maxrecs) * sizeof(xfs_alloc_key_t) + \
101 ((index) - 1) * sizeof(xfs_alloc_ptr_t)))
103 extern struct xfs_btree_cur *xfs_allocbt_init_cursor(struct xfs_mount *,
104 struct xfs_trans *, struct xfs_buf *,
105 xfs_agnumber_t, xfs_btnum_t);
106 extern int xfs_allocbt_maxrecs(struct xfs_mount *, int, int);
108 #endif /* __XFS_ALLOC_BTREE_H__ */