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 struct nilfs_btree; 34 struct nilfs_btree_path; 35 36 /** 37 * struct nilfs_btree_operations - B-tree operation table 38 */ 39 struct nilfs_btree_operations { 40 __u64 (*btop_find_target)(const struct nilfs_btree *, 41 const struct nilfs_btree_path *, __u64); 42 void (*btop_set_target)(struct nilfs_btree *, __u64, __u64); 43 44 struct the_nilfs *(*btop_get_nilfs)(struct nilfs_btree *); 45 46 int (*btop_propagate)(struct nilfs_btree *, 47 struct nilfs_btree_path *, 48 int, 49 struct buffer_head *); 50 int (*btop_assign)(struct nilfs_btree *, 51 struct nilfs_btree_path *, 52 int, 53 struct buffer_head **, 54 sector_t, 55 union nilfs_binfo *); 56 }; 57 58 /** 59 * struct nilfs_btree_node - B-tree node 60 * @bn_flags: flags 61 * @bn_level: level 62 * @bn_nchildren: number of children 63 * @bn_pad: padding 64 */ 65 struct nilfs_btree_node { 66 __u8 bn_flags; 67 __u8 bn_level; 68 __le16 bn_nchildren; 69 __le32 bn_pad; 70 }; 71 72 /* flags */ 73 #define NILFS_BTREE_NODE_ROOT 0x01 74 75 /* level */ 76 #define NILFS_BTREE_LEVEL_DATA 0 77 #define NILFS_BTREE_LEVEL_NODE_MIN (NILFS_BTREE_LEVEL_DATA + 1) 78 #define NILFS_BTREE_LEVEL_MAX 14 79 80 /** 81 * struct nilfs_btree - B-tree structure 82 * @bt_bmap: bmap base structure 83 * @bt_ops: B-tree operation table 84 */ 85 struct nilfs_btree { 86 struct nilfs_bmap bt_bmap; 87 88 /* B-tree-specific members */ 89 const struct nilfs_btree_operations *bt_ops; 90 }; 91 92 93 #define NILFS_BTREE_ROOT_SIZE NILFS_BMAP_SIZE 94 #define NILFS_BTREE_ROOT_NCHILDREN_MAX \ 95 ((NILFS_BTREE_ROOT_SIZE - sizeof(struct nilfs_btree_node)) / \ 96 (sizeof(__le64 /* dkey */) + sizeof(__le64 /* dptr */))) 97 #define NILFS_BTREE_ROOT_NCHILDREN_MIN 0 98 #define NILFS_BTREE_NODE_EXTRA_PAD_SIZE (sizeof(__le64)) 99 #define NILFS_BTREE_NODE_NCHILDREN_MAX(nodesize) \ 100 (((nodesize) - sizeof(struct nilfs_btree_node) - \ 101 NILFS_BTREE_NODE_EXTRA_PAD_SIZE) / \ 102 (sizeof(__le64 /* dkey */) + sizeof(__le64 /* dptr */))) 103 #define NILFS_BTREE_NODE_NCHILDREN_MIN(nodesize) \ 104 ((NILFS_BTREE_NODE_NCHILDREN_MAX(nodesize) - 1) / 2 + 1) 105 #define NILFS_BTREE_KEY_MIN ((__u64)0) 106 #define NILFS_BTREE_KEY_MAX (~(__u64)0) 107 108 109 int nilfs_btree_path_cache_init(void); 110 void nilfs_btree_path_cache_destroy(void); 111 int nilfs_btree_init(struct nilfs_bmap *, __u64, __u64); 112 int nilfs_btree_convert_and_insert(struct nilfs_bmap *, __u64, __u64, 113 const __u64 *, const __u64 *, 114 int, __u64, __u64); 115 void nilfs_btree_init_gc(struct nilfs_bmap *); 116 117 #endif /* _NILFS_BTREE_H */ 118