xref: /openbmc/linux/fs/nilfs2/btree.h (revision b6dcefde)
1 /*
2  * btree.h - NILFS B-tree.
3  *
4  * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
19  *
20  * Written by Koji Sato <koji@osrg.net>.
21  */
22 
23 #ifndef _NILFS_BTREE_H
24 #define _NILFS_BTREE_H
25 
26 #include <linux/types.h>
27 #include <linux/buffer_head.h>
28 #include <linux/list.h>
29 #include <linux/nilfs2_fs.h>
30 #include "btnode.h"
31 #include "bmap.h"
32 
33 struct nilfs_btree;
34 struct nilfs_btree_path;
35 
36 /**
37  * struct nilfs_btree - B-tree structure
38  * @bt_bmap: bmap base structure
39  */
40 struct nilfs_btree {
41 	struct nilfs_bmap bt_bmap;
42 };
43 
44 
45 #define NILFS_BTREE_ROOT_SIZE		NILFS_BMAP_SIZE
46 #define NILFS_BTREE_ROOT_NCHILDREN_MAX					\
47 	((NILFS_BTREE_ROOT_SIZE - sizeof(struct nilfs_btree_node)) /	\
48 	 (sizeof(__le64 /* dkey */) + sizeof(__le64 /* dptr */)))
49 #define NILFS_BTREE_ROOT_NCHILDREN_MIN	0
50 #define NILFS_BTREE_NODE_EXTRA_PAD_SIZE	(sizeof(__le64))
51 #define NILFS_BTREE_NODE_NCHILDREN_MAX(nodesize)			\
52 	(((nodesize) - sizeof(struct nilfs_btree_node) -		\
53 		NILFS_BTREE_NODE_EXTRA_PAD_SIZE) /			\
54 	 (sizeof(__le64 /* dkey */) + sizeof(__le64 /* dptr */)))
55 #define NILFS_BTREE_NODE_NCHILDREN_MIN(nodesize)			\
56 	((NILFS_BTREE_NODE_NCHILDREN_MAX(nodesize) - 1) / 2 + 1)
57 #define NILFS_BTREE_KEY_MIN	((__u64)0)
58 #define NILFS_BTREE_KEY_MAX	(~(__u64)0)
59 
60 
61 int nilfs_btree_path_cache_init(void);
62 void nilfs_btree_path_cache_destroy(void);
63 int nilfs_btree_init(struct nilfs_bmap *);
64 int nilfs_btree_convert_and_insert(struct nilfs_bmap *, __u64, __u64,
65 				   const __u64 *, const __u64 *, int);
66 void nilfs_btree_init_gc(struct nilfs_bmap *);
67 
68 #endif	/* _NILFS_BTREE_H */
69