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_ABTB_CRC_MAGIC 0x41423342 /* 'AB3B' */ 36 #define XFS_ABTC_MAGIC 0x41425443 /* 'ABTC' for cnt tree */ 37 #define XFS_ABTC_CRC_MAGIC 0x41423343 /* 'AB3C' */ 38 39 /* 40 * Data record/key structure 41 */ 42 typedef struct xfs_alloc_rec { 43 __be32 ar_startblock; /* starting block number */ 44 __be32 ar_blockcount; /* count of free blocks */ 45 } xfs_alloc_rec_t, xfs_alloc_key_t; 46 47 typedef struct xfs_alloc_rec_incore { 48 xfs_agblock_t ar_startblock; /* starting block number */ 49 xfs_extlen_t ar_blockcount; /* count of free blocks */ 50 } xfs_alloc_rec_incore_t; 51 52 /* btree pointer type */ 53 typedef __be32 xfs_alloc_ptr_t; 54 55 /* 56 * Block numbers in the AG: 57 * SB is sector 0, AGF is sector 1, AGI is sector 2, AGFL is sector 3. 58 */ 59 #define XFS_BNO_BLOCK(mp) ((xfs_agblock_t)(XFS_AGFL_BLOCK(mp) + 1)) 60 #define XFS_CNT_BLOCK(mp) ((xfs_agblock_t)(XFS_BNO_BLOCK(mp) + 1)) 61 62 /* 63 * Btree block header size depends on a superblock flag. 64 */ 65 #define XFS_ALLOC_BLOCK_LEN(mp) \ 66 (xfs_sb_version_hascrc(&((mp)->m_sb)) ? \ 67 XFS_BTREE_SBLOCK_CRC_LEN : XFS_BTREE_SBLOCK_LEN) 68 69 /* 70 * Record, key, and pointer address macros for btree blocks. 71 * 72 * (note that some of these may appear unused, but they are used in userspace) 73 */ 74 #define XFS_ALLOC_REC_ADDR(mp, block, index) \ 75 ((xfs_alloc_rec_t *) \ 76 ((char *)(block) + \ 77 XFS_ALLOC_BLOCK_LEN(mp) + \ 78 (((index) - 1) * sizeof(xfs_alloc_rec_t)))) 79 80 #define XFS_ALLOC_KEY_ADDR(mp, block, index) \ 81 ((xfs_alloc_key_t *) \ 82 ((char *)(block) + \ 83 XFS_ALLOC_BLOCK_LEN(mp) + \ 84 ((index) - 1) * sizeof(xfs_alloc_key_t))) 85 86 #define XFS_ALLOC_PTR_ADDR(mp, block, index, maxrecs) \ 87 ((xfs_alloc_ptr_t *) \ 88 ((char *)(block) + \ 89 XFS_ALLOC_BLOCK_LEN(mp) + \ 90 (maxrecs) * sizeof(xfs_alloc_key_t) + \ 91 ((index) - 1) * sizeof(xfs_alloc_ptr_t))) 92 93 extern struct xfs_btree_cur *xfs_allocbt_init_cursor(struct xfs_mount *, 94 struct xfs_trans *, struct xfs_buf *, 95 xfs_agnumber_t, xfs_btnum_t); 96 extern int xfs_allocbt_maxrecs(struct xfs_mount *, int, int); 97 98 extern const struct xfs_buf_ops xfs_allocbt_buf_ops; 99 100 #endif /* __XFS_ALLOC_BTREE_H__ */ 101