/*
* btree.h - NILFS B-tree.
*
* Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Written by Koji Sato <koji@osrg.net>.
*/
#ifndef _NILFS_BTREE_H
#define _NILFS_BTREE_H
#include <linux/types.h>
#include <linux/buffer_head.h>
#include <linux/list.h>
#include <linux/nilfs2_fs.h>
#include "btnode.h"
#include "bmap.h"
struct nilfs_btree;
struct nilfs_btree_path;
/**
* struct nilfs_btree_operations - B-tree operation table
*/
struct nilfs_btree_operations {
__u64 (*btop_find_target)(const struct nilfs_btree *,
const struct nilfs_btree_path *, __u64);
void (*btop_set_target)(struct nilfs_btree *, __u64, __u64);
struct the_nilfs *(*btop_get_nilfs)(struct nilfs_btree *);
int (*btop_propagate)(struct nilfs_btree *,
struct nilfs_btree_path *,
int,
struct buffer_head *);
int (*btop_assign)(struct nilfs_btree *,
struct nilfs_btree_path *,
int,
struct buffer_head **,
sector_t,
union nilfs_binfo *);
};
/**
* struct nilfs_btree_node - B-tree node
* @bn_flags: flags
* @bn_level: level
* @bn_nchildren: number of children
* @bn_pad: padding
*/
struct nilfs_btree_node {
__u8 bn_flags;
__u8 bn_level;
__le16 bn_nchildren;
__le32 bn_pad;
};
/* flags */
#define NILFS_BTREE_NODE_ROOT 0x01
/* level */
#define NILFS_BTREE_LEVEL_DATA 0
#define NILFS_BTREE_LEVEL_NODE_MIN (NILFS_BTREE_LEVEL_DATA + 1)
#define NILFS_BTREE_LEVEL_MAX 14
/**
* struct nilfs_btree - B-tree structure
* @bt_bmap: bmap base structure
* @bt_ops: B-tree operation table
*/
struct nilfs_btree {
struct nilfs_bmap bt_bmap;
/* B-tree-specific members */
const struct nilfs_btree_operations *bt_ops;
};
#define NILFS_BTREE_ROOT_SIZE NILFS_BMAP_SIZE
#define NILFS_BTREE_ROOT_NCHILDREN_MAX \
((NILFS_BTREE_ROOT_SIZE - sizeof(struct nilfs_btree_node)) / \
(sizeof(__le64 /* dkey */) + sizeof(__le64 /* dptr */)))
#define NILFS_BTREE_ROOT_NCHILDREN_MIN 0
#define NILFS_BTREE_NODE_EXTRA_PAD_SIZE (sizeof(__le64))
#define NILFS_BTREE_NODE_NCHILDREN_MAX(nodesize) \
(((nodesize) - sizeof(struct nilfs_btree_node) - \
NILFS_BTREE_NODE_EXTRA_PAD_SIZE) / \
(sizeof(__le64 /* dkey */) + sizeof(__le64 /* dptr */)))
#define NILFS_BTREE_NODE_NCHILDREN_MIN(nodesize) \
((NILFS_BTREE_NODE_NCHILDREN_MAX(nodesize) - 1) / 2 + 1)
#define NILFS_BTREE_KEY_MIN ((__u64)0)
#define NILFS_BTREE_KEY_MAX (~(__u64)0)
int nilfs_btree_path_cache_init(void);
void nilfs_btree_path_cache_destroy(void);
int nilfs_btree_init(struct nilfs_bmap *, __u64, __u64);
int nilfs_btree_convert_and_insert(struct nilfs_bmap *, __u64, __u64,
const __u64 *, const __u64 *,
int, __u64, __u64);
void nilfs_btree_init_gc(struct nilfs_bmap *);
#endif /* _NILFS_BTREE_H */
