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/**
34 * struct nilfs_btree_path - A path on which B-tree operations are executed
35 * @bp_bh: buffer head of node block
36 * @bp_sib_bh: buffer head of sibling node block
37 * @bp_index: index of child node
38 * @bp_oldreq: ptr end request for old ptr
39 * @bp_newreq: ptr alloc request for new ptr
40 * @bp_op: rebalance operation
41 */
42struct nilfs_btree_path {
43	struct buffer_head *bp_bh;
44	struct buffer_head *bp_sib_bh;
45	int bp_index;
46	union nilfs_bmap_ptr_req bp_oldreq;
47	union nilfs_bmap_ptr_req bp_newreq;
48	struct nilfs_btnode_chkey_ctxt bp_ctxt;
49	void (*bp_op)(struct nilfs_bmap *, struct nilfs_btree_path *,
50		      int, __u64 *, __u64 *);
51};
52
53#define NILFS_BTREE_ROOT_SIZE		NILFS_BMAP_SIZE
54#define NILFS_BTREE_ROOT_NCHILDREN_MAX					\
55	((NILFS_BTREE_ROOT_SIZE - sizeof(struct nilfs_btree_node)) /	\
56	 (sizeof(__le64 /* dkey */) + sizeof(__le64 /* dptr */)))
57#define NILFS_BTREE_ROOT_NCHILDREN_MIN	0
58#define NILFS_BTREE_NODE_EXTRA_PAD_SIZE	(sizeof(__le64))
59#define NILFS_BTREE_NODE_NCHILDREN_MAX(nodesize)			\
60	(((nodesize) - sizeof(struct nilfs_btree_node) -		\
61		NILFS_BTREE_NODE_EXTRA_PAD_SIZE) /			\
62	 (sizeof(__le64 /* dkey */) + sizeof(__le64 /* dptr */)))
63#define NILFS_BTREE_NODE_NCHILDREN_MIN(nodesize)			\
64	((NILFS_BTREE_NODE_NCHILDREN_MAX(nodesize) - 1) / 2 + 1)
65#define NILFS_BTREE_KEY_MIN	((__u64)0)
66#define NILFS_BTREE_KEY_MAX	(~(__u64)0)
67
68extern struct kmem_cache *nilfs_btree_path_cache;
69
70int nilfs_btree_init(struct nilfs_bmap *);
71int nilfs_btree_convert_and_insert(struct nilfs_bmap *, __u64, __u64,
72				   const __u64 *, const __u64 *, int);
73void nilfs_btree_init_gc(struct nilfs_bmap *);
74
75int nilfs_btree_broken_node_block(struct buffer_head *bh);
76
77#endif	/* _NILFS_BTREE_H */
78