xref: /linux/fs/xfs/libxfs/xfs_alloc_btree.h (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
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  * Btree block header size depends on a superblock flag.
31  */
32 #define XFS_ALLOC_BLOCK_LEN(mp) \
33 	(xfs_sb_version_hascrc(&((mp)->m_sb)) ? \
34 		XFS_BTREE_SBLOCK_CRC_LEN : XFS_BTREE_SBLOCK_LEN)
35 
36 /*
37  * Record, key, and pointer address macros for btree blocks.
38  *
39  * (note that some of these may appear unused, but they are used in userspace)
40  */
41 #define XFS_ALLOC_REC_ADDR(mp, block, index) \
42 	((xfs_alloc_rec_t *) \
43 		((char *)(block) + \
44 		 XFS_ALLOC_BLOCK_LEN(mp) + \
45 		 (((index) - 1) * sizeof(xfs_alloc_rec_t))))
46 
47 #define XFS_ALLOC_KEY_ADDR(mp, block, index) \
48 	((xfs_alloc_key_t *) \
49 		((char *)(block) + \
50 		 XFS_ALLOC_BLOCK_LEN(mp) + \
51 		 ((index) - 1) * sizeof(xfs_alloc_key_t)))
52 
53 #define XFS_ALLOC_PTR_ADDR(mp, block, index, maxrecs) \
54 	((xfs_alloc_ptr_t *) \
55 		((char *)(block) + \
56 		 XFS_ALLOC_BLOCK_LEN(mp) + \
57 		 (maxrecs) * sizeof(xfs_alloc_key_t) + \
58 		 ((index) - 1) * sizeof(xfs_alloc_ptr_t)))
59 
60 extern struct xfs_btree_cur *xfs_allocbt_init_cursor(struct xfs_mount *,
61 		struct xfs_trans *, struct xfs_buf *,
62 		xfs_agnumber_t, xfs_btnum_t);
63 extern int xfs_allocbt_maxrecs(struct xfs_mount *, int, int);
64 
65 #endif	/* __XFS_ALLOC_BTREE_H__ */
66