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/*
* 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.
*
* Written by Koji Sato.
*/
#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_path - A path on which B-tree operations are executed
* @bp_bh: buffer head of node block
* @bp_sib_bh: buffer head of sibling node block
* @bp_index: index of child node
* @bp_oldreq: ptr end request for old ptr
* @bp_newreq: ptr alloc request for new ptr
* @bp_op: rebalance operation
*/
struct nilfs_btree_path {
struct buffer_head *bp_bh;
struct buffer_head *bp_sib_bh;
int bp_index;
union nilfs_bmap_ptr_req bp_oldreq;
union nilfs_bmap_ptr_req bp_newreq;
struct nilfs_btnode_chkey_ctxt bp_ctxt;
void (*bp_op)(struct nilfs_bmap *, struct nilfs_btree_path *,
int, __u64 *, __u64 *);
};
#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)
extern struct kmem_cache *nilfs_btree_path_cache;
int nilfs_btree_init(struct nilfs_bmap *);
int nilfs_btree_convert_and_insert(struct nilfs_bmap *, __u64, __u64,
const __u64 *, const __u64 *, int);
void nilfs_btree_init_gc(struct nilfs_bmap *);
int nilfs_btree_broken_node_block(struct buffer_head *bh);
#endif /* _NILFS_BTREE_H */