LXR linux/fs/nilfs2/btree.h

   1/* SPDX-License-Identifier: GPL-2.0+ */
   2/*
   3 * btree.h - NILFS B-tree.
   4 *
   5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
   6 *
   7 * Written by Koji Sato.
   8 */
   9
  10#ifndef _NILFS_BTREE_H
  11#define _NILFS_BTREE_H
  12
  13#include <linux/types.h>
  14#include <linux/buffer_head.h>
  15#include <linux/list.h>
  16#include <linux/nilfs2_ondisk.h>        /* nilfs_btree_node */
  17#include "btnode.h"
  18#include "bmap.h"
  19
  20/**
  21 * struct nilfs_btree_path - A path on which B-tree operations are executed
  22 * @bp_bh: buffer head of node block
  23 * @bp_sib_bh: buffer head of sibling node block
  24 * @bp_index: index of child node
  25 * @bp_oldreq: ptr end request for old ptr
  26 * @bp_newreq: ptr alloc request for new ptr
  27 * @bp_op: rebalance operation
  28 */
  29struct nilfs_btree_path {
  30        struct buffer_head *bp_bh;
  31        struct buffer_head *bp_sib_bh;
  32        int bp_index;
  33        union nilfs_bmap_ptr_req bp_oldreq;
  34        union nilfs_bmap_ptr_req bp_newreq;
  35        struct nilfs_btnode_chkey_ctxt bp_ctxt;
  36        void (*bp_op)(struct nilfs_bmap *, struct nilfs_btree_path *,
  37                      int, __u64 *, __u64 *);
  38};
  39
  40#define NILFS_BTREE_ROOT_SIZE           NILFS_BMAP_SIZE
  41#define NILFS_BTREE_ROOT_NCHILDREN_MAX                                  \
  42        ((NILFS_BTREE_ROOT_SIZE - sizeof(struct nilfs_btree_node)) /    \
  43         (sizeof(__le64 /* dkey */) + sizeof(__le64 /* dptr */)))
  44#define NILFS_BTREE_ROOT_NCHILDREN_MIN  0
  45#define NILFS_BTREE_NODE_EXTRA_PAD_SIZE (sizeof(__le64))
  46#define NILFS_BTREE_NODE_NCHILDREN_MAX(nodesize)                        \
  47        (((nodesize) - sizeof(struct nilfs_btree_node) -                \
  48                NILFS_BTREE_NODE_EXTRA_PAD_SIZE) /                      \
  49         (sizeof(__le64 /* dkey */) + sizeof(__le64 /* dptr */)))
  50#define NILFS_BTREE_NODE_NCHILDREN_MIN(nodesize)                        \
  51        ((NILFS_BTREE_NODE_NCHILDREN_MAX(nodesize) - 1) / 2 + 1)
  52#define NILFS_BTREE_KEY_MIN     ((__u64)0)
  53#define NILFS_BTREE_KEY_MAX     (~(__u64)0)
  54
  55extern struct kmem_cache *nilfs_btree_path_cache;
  56
  57int nilfs_btree_init(struct nilfs_bmap *);
  58int nilfs_btree_convert_and_insert(struct nilfs_bmap *, __u64, __u64,
  59                                   const __u64 *, const __u64 *, int);
  60void nilfs_btree_init_gc(struct nilfs_bmap *);
  61
  62int nilfs_btree_broken_node_block(struct buffer_head *bh);
  63
  64#endif  /* _NILFS_BTREE_H */
  65