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 25 struct xfs_buf; 26 struct xfs_btree_cur; 27 struct 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 */ 40 typedef 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 45 typedef 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 */ 51 typedef __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))) 104 105 extern 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); 108 extern int xfs_allocbt_maxrecs(struct xfs_mount *, int, int); 109 110 #endif /* __XFS_ALLOC_BTREE_H__ */ 111