LXR linux/fs/nilfs2/btree.h

   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