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_IALLOC_BTREE_H__
 19#define	__XFS_IALLOC_BTREE_H__
 20
 21/*
 22 * Inode map on-disk structures
 23 */
 24
 25struct xfs_buf;
 26struct xfs_btree_cur;
 27struct xfs_mount;
 28
 29/*
 30 * There is a btree for the inode map per allocation group.
 31 */
 32#define	XFS_IBT_MAGIC	0x49414254	/* 'IABT' */
 33
 34typedef	__uint64_t	xfs_inofree_t;
 35#define	XFS_INODES_PER_CHUNK		(NBBY * sizeof(xfs_inofree_t))
 36#define	XFS_INODES_PER_CHUNK_LOG	(XFS_NBBYLOG + 3)
 37#define	XFS_INOBT_ALL_FREE		((xfs_inofree_t)-1)
 38#define	XFS_INOBT_MASK(i)		((xfs_inofree_t)1 << (i))
 39
 40static inline xfs_inofree_t xfs_inobt_maskn(int i, int n)
 41{
 42	return ((n >= XFS_INODES_PER_CHUNK ? 0 : XFS_INOBT_MASK(n)) - 1) << i;
 43}
 44
 45/*
 46 * Data record structure
 47 */
 48typedef struct xfs_inobt_rec {
 49	__be32		ir_startino;	/* starting inode number */
 50	__be32		ir_freecount;	/* count of free inodes (set bits) */
 51	__be64		ir_free;	/* free inode mask */
 52} xfs_inobt_rec_t;
 53
 54typedef struct xfs_inobt_rec_incore {
 55	xfs_agino_t	ir_startino;	/* starting inode number */
 56	__int32_t	ir_freecount;	/* count of free inodes (set bits) */
 57	xfs_inofree_t	ir_free;	/* free inode mask */
 58} xfs_inobt_rec_incore_t;
 59
 60
 61/*
 62 * Key structure
 63 */
 64typedef struct xfs_inobt_key {
 65	__be32		ir_startino;	/* starting inode number */
 66} xfs_inobt_key_t;
 67
 68/* btree pointer type */
 69typedef __be32 xfs_inobt_ptr_t;
 70
 71/*
 72 * block numbers in the AG.
 73 */
 74#define	XFS_IBT_BLOCK(mp)		((xfs_agblock_t)(XFS_CNT_BLOCK(mp) + 1))
 75#define	XFS_PREALLOC_BLOCKS(mp)		((xfs_agblock_t)(XFS_IBT_BLOCK(mp) + 1))
 76
 77/*
 78 * Btree block header size depends on a superblock flag.
 79 *
 80 * (not quite yet, but soon)
 81 */
 82#define XFS_INOBT_BLOCK_LEN(mp)	XFS_BTREE_SBLOCK_LEN
 83
 84/*
 85 * Record, key, and pointer address macros for btree blocks.
 86 *
 87 * (note that some of these may appear unused, but they are used in userspace)
 88 */
 89#define XFS_INOBT_REC_ADDR(mp, block, index) \
 90	((xfs_inobt_rec_t *) \
 91		((char *)(block) + \
 92		 XFS_INOBT_BLOCK_LEN(mp) + \
 93		 (((index) - 1) * sizeof(xfs_inobt_rec_t))))
 94
 95#define XFS_INOBT_KEY_ADDR(mp, block, index) \
 96	((xfs_inobt_key_t *) \
 97		((char *)(block) + \
 98		 XFS_INOBT_BLOCK_LEN(mp) + \
 99		 ((index) - 1) * sizeof(xfs_inobt_key_t)))
100
101#define XFS_INOBT_PTR_ADDR(mp, block, index, maxrecs) \
102	((xfs_inobt_ptr_t *) \
103		((char *)(block) + \
104		 XFS_INOBT_BLOCK_LEN(mp) + \
105		 (maxrecs) * sizeof(xfs_inobt_key_t) + \
106		 ((index) - 1) * sizeof(xfs_inobt_ptr_t)))
107
108extern struct xfs_btree_cur *xfs_inobt_init_cursor(struct xfs_mount *,
109		struct xfs_trans *, struct xfs_buf *, xfs_agnumber_t);
110extern int xfs_inobt_maxrecs(struct xfs_mount *, int, int);
111
112#endif	/* __XFS_IALLOC_BTREE_H__ */