[net-next-2.6.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_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;

/*
 * 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))

/*
 * Btree block header size depends on a superblock flag.
 *
 * (not quite yet, but soon)
 */
#define XFS_ALLOC_BLOCK_LEN(mp)	XFS_BTREE_SBLOCK_LEN

/*
 * 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) + \
		 XFS_ALLOC_BLOCK_LEN(mp) + \
		 (((index) - 1) * sizeof(xfs_alloc_rec_t))))

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

#define XFS_ALLOC_PTR_ADDR(mp, block, index, maxrecs) \
	((xfs_alloc_ptr_t *) \
		((char *)(block) + \
		 XFS_ALLOC_BLOCK_LEN(mp) + \
		 (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;
1da177e4 LT	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	*/
16259e7d CH	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 {
1da177e4 LT	46	xfs_agblock_t ar_startblock; /* starting block number */
1da177e4 LT	47	xfs_extlen_t ar_blockcount; /* count of free blocks */
16259e7d	48	} xfs_alloc_rec_incore_t;
1da177e4	49
16259e7d CH	50	/* btree pointer type */
16259e7d CH	51	typedef __be32 xfs_alloc_ptr_t;
1da177e4	52
1da177e4 LT	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	*/
1da177e4	71	#define XFS_BNO_BLOCK(mp) ((xfs_agblock_t)(XFS_AGFL_BLOCK(mp) + 1))
1da177e4	72	#define XFS_CNT_BLOCK(mp) ((xfs_agblock_t)(XFS_BNO_BLOCK(mp) + 1))
1da177e4	73
7cc95a82 CH	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
1da177e4 LT	81	/*
1da177e4 LT	82	* Record, key, and pointer address macros for btree blocks.
136341b4 CH	83	*
136341b4 CH	84	* (note that some of these may appear unused, but they are used in userspace)
1da177e4	85	*/
136341b4 CH	86	#define XFS_ALLOC_REC_ADDR(mp, block, index) \
	87	((xfs_alloc_rec_t *) \
	88	((char *)(block) + \
7cc95a82	89	XFS_ALLOC_BLOCK_LEN(mp) + \
136341b4	90	(((index) - 1) * sizeof(xfs_alloc_rec_t))))
1da177e4	91
136341b4 CH	92	#define XFS_ALLOC_KEY_ADDR(mp, block, index) \
	93	((xfs_alloc_key_t *) \
	94	((char *)(block) + \
7cc95a82	95	XFS_ALLOC_BLOCK_LEN(mp) + \
136341b4	96	((index) - 1) * sizeof(xfs_alloc_key_t)))
1da177e4	97
136341b4 CH	98	#define XFS_ALLOC_PTR_ADDR(mp, block, index, maxrecs) \
	99	((xfs_alloc_ptr_t *) \
	100	((char *)(block) + \
7cc95a82	101	XFS_ALLOC_BLOCK_LEN(mp) + \
136341b4 CH	102	(maxrecs) * sizeof(xfs_alloc_key_t) + \
136341b4 CH	103	((index) - 1) * sizeof(xfs_alloc_ptr_t)))
561f7d17 CH	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);
60197e8d	108	extern int xfs_allocbt_maxrecs(struct xfs_mount *, int, int);
561f7d17	109
1da177e4	110	#endif /* __XFS_ALLOC_BTREE_H__ */