17c76b0104
This adds declarations and functions of NILFS2 B-tree. Two variants are integrated in the NILFS2 B-tree. The B-tree for the most files points to the child nodes or data blocks with virtual block addresses, whereas the B-tree of the DAT uses actual block addresses. Signed-off-by: Koji Sato <sato.koji@lab.ntt.co.jp> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
117 lines
3.4 KiB
C
117 lines
3.4 KiB
C
/*
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* btree.h - NILFS B-tree.
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*
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* Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*
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* Written by Koji Sato <koji@osrg.net>.
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*/
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#ifndef _NILFS_BTREE_H
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#define _NILFS_BTREE_H
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#include <linux/types.h>
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#include <linux/buffer_head.h>
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#include <linux/list.h>
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#include <linux/nilfs2_fs.h>
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#include "btnode.h"
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#include "bmap.h"
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struct nilfs_btree;
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struct nilfs_btree_path;
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/**
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* struct nilfs_btree_operations - B-tree operation table
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*/
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struct nilfs_btree_operations {
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__u64 (*btop_find_target)(const struct nilfs_btree *,
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const struct nilfs_btree_path *, __u64);
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void (*btop_set_target)(struct nilfs_btree *, __u64, __u64);
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struct the_nilfs *(*btop_get_nilfs)(struct nilfs_btree *);
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int (*btop_propagate)(struct nilfs_btree *,
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struct nilfs_btree_path *,
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int,
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struct buffer_head *);
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int (*btop_assign)(struct nilfs_btree *,
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struct nilfs_btree_path *,
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int,
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struct buffer_head **,
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sector_t,
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union nilfs_binfo *);
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};
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/**
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* struct nilfs_btree_node - B-tree node
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* @bn_flags: flags
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* @bn_level: level
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* @bn_nchildren: number of children
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* @bn_pad: padding
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*/
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struct nilfs_btree_node {
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__u8 bn_flags;
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__u8 bn_level;
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__le16 bn_nchildren;
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__le32 bn_pad;
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};
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/* flags */
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#define NILFS_BTREE_NODE_ROOT 0x01
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/* level */
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#define NILFS_BTREE_LEVEL_DATA 0
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#define NILFS_BTREE_LEVEL_NODE_MIN (NILFS_BTREE_LEVEL_DATA + 1)
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#define NILFS_BTREE_LEVEL_MAX 14
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/**
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* struct nilfs_btree - B-tree structure
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* @bt_bmap: bmap base structure
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* @bt_ops: B-tree operation table
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*/
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struct nilfs_btree {
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struct nilfs_bmap bt_bmap;
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/* B-tree-specific members */
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const struct nilfs_btree_operations *bt_ops;
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};
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#define NILFS_BTREE_ROOT_SIZE NILFS_BMAP_SIZE
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#define NILFS_BTREE_ROOT_NCHILDREN_MAX \
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((NILFS_BTREE_ROOT_SIZE - sizeof(struct nilfs_btree_node)) / \
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(sizeof(__le64 /* dkey */) + sizeof(__le64 /* dptr */)))
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#define NILFS_BTREE_ROOT_NCHILDREN_MIN 0
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#define NILFS_BTREE_NODE_EXTRA_PAD_SIZE (sizeof(__le64))
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#define NILFS_BTREE_NODE_NCHILDREN_MAX(nodesize) \
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(((nodesize) - sizeof(struct nilfs_btree_node) - \
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NILFS_BTREE_NODE_EXTRA_PAD_SIZE) / \
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(sizeof(__le64 /* dkey */) + sizeof(__le64 /* dptr */)))
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#define NILFS_BTREE_NODE_NCHILDREN_MIN(nodesize) \
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((NILFS_BTREE_NODE_NCHILDREN_MAX(nodesize) - 1) / 2 + 1)
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#define NILFS_BTREE_KEY_MIN ((__u64)0)
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#define NILFS_BTREE_KEY_MAX (~(__u64)0)
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int nilfs_btree_path_cache_init(void);
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void nilfs_btree_path_cache_destroy(void);
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int nilfs_btree_init(struct nilfs_bmap *, __u64, __u64);
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int nilfs_btree_convert_and_insert(struct nilfs_bmap *, __u64, __u64,
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const __u64 *, const __u64 *,
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int, __u64, __u64);
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void nilfs_btree_init_gc(struct nilfs_bmap *);
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#endif /* _NILFS_BTREE_H */
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