[deliverable/linux.git] / fs / xfs / xfs_alloc_btree.h

/*
 * Copyright (c) 2000,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#ifndef __XFS_ALLOC_BTREE_H__
#define	__XFS_ALLOC_BTREE_H__

/*
 * Freespace on-disk structures
 */

struct xfs_buf;
struct xfs_btree_cur;
struct xfs_btree_sblock;
struct xfs_mount;

/*
 * There are two on-disk btrees, one sorted by blockno and one sorted
 * by blockcount and blockno.  All blocks look the same to make the code
 * simpler; if we have time later, we'll make the optimizations.
 */
#define	XFS_ABTB_MAGIC	0x41425442	/* 'ABTB' for bno tree */
#define	XFS_ABTC_MAGIC	0x41425443	/* 'ABTC' for cnt tree */

/*
 * Data record/key structure
 */
typedef struct xfs_alloc_rec {
	__be32		ar_startblock;	/* starting block number */
	__be32		ar_blockcount;	/* count of free blocks */
} xfs_alloc_rec_t, xfs_alloc_key_t;

typedef struct xfs_alloc_rec_incore {
	xfs_agblock_t	ar_startblock;	/* starting block number */
	xfs_extlen_t	ar_blockcount;	/* count of free blocks */
} xfs_alloc_rec_incore_t;

/* btree pointer type */
typedef __be32 xfs_alloc_ptr_t;
/* btree block header type */
typedef	struct xfs_btree_sblock xfs_alloc_block_t;

#define	XFS_BUF_TO_ALLOC_BLOCK(bp)	((xfs_alloc_block_t *)XFS_BUF_PTR(bp))

/*
 * Minimum and maximum blocksize and sectorsize.
 * The blocksize upper limit is pretty much arbitrary.
 * The sectorsize upper limit is due to sizeof(sb_sectsize).
 */
#define XFS_MIN_BLOCKSIZE_LOG	9	/* i.e. 512 bytes */
#define XFS_MAX_BLOCKSIZE_LOG	16	/* i.e. 65536 bytes */
#define XFS_MIN_BLOCKSIZE	(1 << XFS_MIN_BLOCKSIZE_LOG)
#define XFS_MAX_BLOCKSIZE	(1 << XFS_MAX_BLOCKSIZE_LOG)
#define XFS_MIN_SECTORSIZE_LOG	9	/* i.e. 512 bytes */
#define XFS_MAX_SECTORSIZE_LOG	15	/* i.e. 32768 bytes */
#define XFS_MIN_SECTORSIZE	(1 << XFS_MIN_SECTORSIZE_LOG)
#define XFS_MAX_SECTORSIZE	(1 << XFS_MAX_SECTORSIZE_LOG)

/*
 * Block numbers in the AG:
 * SB is sector 0, AGF is sector 1, AGI is sector 2, AGFL is sector 3.
 */
#define	XFS_BNO_BLOCK(mp)	((xfs_agblock_t)(XFS_AGFL_BLOCK(mp) + 1))
#define	XFS_CNT_BLOCK(mp)	((xfs_agblock_t)(XFS_BNO_BLOCK(mp) + 1))

/*
 * Record, key, and pointer address macros for btree blocks.
 *
 * (note that some of these may appear unused, but they are used in userspace)
 */
#define XFS_ALLOC_REC_ADDR(mp, block, index) \
	((xfs_alloc_rec_t *) \
		((char *)(block) + \
		 sizeof(struct xfs_btree_sblock) + \
		 (((index) - 1) * sizeof(xfs_alloc_rec_t))))

#define XFS_ALLOC_KEY_ADDR(mp, block, index) \
	((xfs_alloc_key_t *) \
		((char *)(block) + \
		 sizeof(struct xfs_btree_sblock) + \
		 ((index) - 1) * sizeof(xfs_alloc_key_t)))

#define XFS_ALLOC_PTR_ADDR(mp, block, index, maxrecs) \
	((xfs_alloc_ptr_t *) \
		((char *)(block) + \
		 sizeof(struct xfs_btree_sblock) + \
		 (maxrecs) * sizeof(xfs_alloc_key_t) + \
		 ((index) - 1) * sizeof(xfs_alloc_ptr_t)))

extern struct xfs_btree_cur *xfs_allocbt_init_cursor(struct xfs_mount *,
		struct xfs_trans *, struct xfs_buf *,
		xfs_agnumber_t, xfs_btnum_t);
extern int xfs_allocbt_maxrecs(struct xfs_mount *, int, int);

#endif	/* __XFS_ALLOC_BTREE_H__ */
Commit	Line	Data
1da177e4	1	/*
7b718769 NS	2	* Copyright (c) 2000,2005 Silicon Graphics, Inc.
7b718769 NS	3	* All Rights Reserved.
1da177e4	4	*
7b718769 NS	5	* This program is free software; you can redistribute it and/or
7b718769 NS	6	* modify it under the terms of the GNU General Public License as
1da177e4 LT	7	* published by the Free Software Foundation.
1da177e4 LT	8	*
7b718769 NS	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.
1da177e4	13	*
7b718769 NS	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
1da177e4 LT	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_btree_sblock;
	28	struct 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	*/
16259e7d CH	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;
	45
	46	typedef struct xfs_alloc_rec_incore {
1da177e4 LT	47	xfs_agblock_t ar_startblock; /* starting block number */
1da177e4 LT	48	xfs_extlen_t ar_blockcount; /* count of free blocks */
16259e7d	49	} xfs_alloc_rec_incore_t;
1da177e4	50
16259e7d CH	51	/* btree pointer type */
	52	typedef __be32 xfs_alloc_ptr_t;
	53	/* btree block header type */
1da177e4 LT	54	typedef struct xfs_btree_sblock xfs_alloc_block_t;
1da177e4 LT	55
a844f451	56	#define XFS_BUF_TO_ALLOC_BLOCK(bp) ((xfs_alloc_block_t *)XFS_BUF_PTR(bp))
1da177e4	57
1da177e4 LT	58	/*
	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).
	62	*/
	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)
	71
	72	/*
	73	* Block numbers in the AG:
	74	* SB is sector 0, AGF is sector 1, AGI is sector 2, AGFL is sector 3.
	75	*/
1da177e4	76	#define XFS_BNO_BLOCK(mp) ((xfs_agblock_t)(XFS_AGFL_BLOCK(mp) + 1))
1da177e4	77	#define XFS_CNT_BLOCK(mp) ((xfs_agblock_t)(XFS_BNO_BLOCK(mp) + 1))
1da177e4 LT	78
	79	/*
	80	* Record, key, and pointer address macros for btree blocks.
136341b4 CH	81	*
136341b4 CH	82	* (note that some of these may appear unused, but they are used in userspace)
1da177e4	83	*/
136341b4 CH	84	#define XFS_ALLOC_REC_ADDR(mp, block, index) \
	85	((xfs_alloc_rec_t *) \
	86	((char *)(block) + \
	87	sizeof(struct xfs_btree_sblock) + \
	88	(((index) - 1) * sizeof(xfs_alloc_rec_t))))
1da177e4	89
136341b4 CH	90	#define XFS_ALLOC_KEY_ADDR(mp, block, index) \
	91	((xfs_alloc_key_t *) \
	92	((char *)(block) + \
	93	sizeof(struct xfs_btree_sblock) + \
	94	((index) - 1) * sizeof(xfs_alloc_key_t)))
1da177e4	95
136341b4 CH	96	#define XFS_ALLOC_PTR_ADDR(mp, block, index, maxrecs) \
	97	((xfs_alloc_ptr_t *) \
	98	((char *)(block) + \
	99	sizeof(struct xfs_btree_sblock) + \
	100	(maxrecs) * sizeof(xfs_alloc_key_t) + \
	101	((index) - 1) * sizeof(xfs_alloc_ptr_t)))
561f7d17 CH	102
	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);
60197e8d	106	extern int xfs_allocbt_maxrecs(struct xfs_mount *, int, int);
561f7d17	107
1da177e4	108	#endif /* __XFS_ALLOC_BTREE_H__ */