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 
25 struct xfs_buf;
26 struct xfs_btree_cur;
27 struct 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 
34 typedef	__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 
xfs_inobt_maskn(int i,int n)40 static 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  */
48 typedef 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 
54 typedef 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  */
64 typedef struct xfs_inobt_key {
65 	__be32		ir_startino;	/* starting inode number */
66 } xfs_inobt_key_t;
67 
68 /* btree pointer type */
69 typedef __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 
108 extern struct xfs_btree_cur *xfs_inobt_init_cursor(struct xfs_mount *,
109 		struct xfs_trans *, struct xfs_buf *, xfs_agnumber_t);
110 extern int xfs_inobt_maxrecs(struct xfs_mount *, int, int);
111 
112 #endif	/* __XFS_IALLOC_BTREE_H__ */
113