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  * Written by Koji Sato.
  17  */
  18
  19 #ifndef _NILFS_BTREE_H
  20 #define _NILFS_BTREE_H
  21
  22 #include <linux/types.h>
  23 #include <linux/buffer_head.h>
  24 #include <linux/list.h>
  25 #include <linux/nilfs2_ondisk.h>        /* nilfs_btree_node */
  26 #include "btnode.h"
  27 #include "bmap.h"
  28
  29 /**
  30  * struct nilfs_btree_path - A path on which B-tree operations are executed
  31  * @bp_bh: buffer head of node block
  32  * @bp_sib_bh: buffer head of sibling node block
  33  * @bp_index: index of child node
  34  * @bp_oldreq: ptr end request for old ptr
  35  * @bp_newreq: ptr alloc request for new ptr
  36  * @bp_op: rebalance operation
  37  */
  38 struct nilfs_btree_path {
  39         struct buffer_head *bp_bh;
  40         struct buffer_head *bp_sib_bh;
  41         int bp_index;
  42         union nilfs_bmap_ptr_req bp_oldreq;
  43         union nilfs_bmap_ptr_req bp_newreq;
  44         struct nilfs_btnode_chkey_ctxt bp_ctxt;
  45         void (*bp_op)(struct nilfs_bmap *, struct nilfs_btree_path *,
  46                       int, __u64 *, __u64 *);
  47 };
  48
  49 #define NILFS_BTREE_ROOT_SIZE           NILFS_BMAP_SIZE
  50 #define NILFS_BTREE_ROOT_NCHILDREN_MAX                                  \
  51         ((NILFS_BTREE_ROOT_SIZE - sizeof(struct nilfs_btree_node)) /    \
  52          (sizeof(__le64 /* dkey */) + sizeof(__le64 /* dptr */)))
  53 #define NILFS_BTREE_ROOT_NCHILDREN_MIN  0
  54 #define NILFS_BTREE_NODE_EXTRA_PAD_SIZE (sizeof(__le64))
  55 #define NILFS_BTREE_NODE_NCHILDREN_MAX(nodesize)                        \
  56         (((nodesize) - sizeof(struct nilfs_btree_node) -                \
  57                 NILFS_BTREE_NODE_EXTRA_PAD_SIZE) /                      \
  58          (sizeof(__le64 /* dkey */) + sizeof(__le64 /* dptr */)))
  59 #define NILFS_BTREE_NODE_NCHILDREN_MIN(nodesize)                        \
  60         ((NILFS_BTREE_NODE_NCHILDREN_MAX(nodesize) - 1) / 2 + 1)
  61 #define NILFS_BTREE_KEY_MIN     ((__u64)0)
  62 #define NILFS_BTREE_KEY_MAX     (~(__u64)0)
  63
  64 extern struct kmem_cache *nilfs_btree_path_cache;
  65
  66 int nilfs_btree_init(struct nilfs_bmap *);
  67 int nilfs_btree_convert_and_insert(struct nilfs_bmap *, __u64, __u64,
  68                                    const __u64 *, const __u64 *, int);
  69 void nilfs_btree_init_gc(struct nilfs_bmap *);
  70
  71 int nilfs_btree_broken_node_block(struct buffer_head *bh);
  72
  73 #endif  /* _NILFS_BTREE_H */