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_node - B-tree node 38 * @bn_flags: flags 39 * @bn_level: level 40 * @bn_nchildren: number of children 41 * @bn_pad: padding 42 */ 43 struct nilfs_btree_node { 44 __u8 bn_flags; 45 __u8 bn_level; 46 __le16 bn_nchildren; 47 __le32 bn_pad; 48 }; 49 50 /* flags */ 51 #define NILFS_BTREE_NODE_ROOT 0x01 52 53 /* level */ 54 #define NILFS_BTREE_LEVEL_DATA 0 55 #define NILFS_BTREE_LEVEL_NODE_MIN (NILFS_BTREE_LEVEL_DATA + 1) 56 #define NILFS_BTREE_LEVEL_MAX 14 57 58 /** 59 * struct nilfs_btree - B-tree structure 60 * @bt_bmap: bmap base structure 61 */ 62 struct nilfs_btree { 63 struct nilfs_bmap bt_bmap; 64 }; 65 66 67 #define NILFS_BTREE_ROOT_SIZE NILFS_BMAP_SIZE 68 #define NILFS_BTREE_ROOT_NCHILDREN_MAX \ 69 ((NILFS_BTREE_ROOT_SIZE - sizeof(struct nilfs_btree_node)) / \ 70 (sizeof(__le64 /* dkey */) + sizeof(__le64 /* dptr */))) 71 #define NILFS_BTREE_ROOT_NCHILDREN_MIN 0 72 #define NILFS_BTREE_NODE_EXTRA_PAD_SIZE (sizeof(__le64)) 73 #define NILFS_BTREE_NODE_NCHILDREN_MAX(nodesize) \ 74 (((nodesize) - sizeof(struct nilfs_btree_node) - \ 75 NILFS_BTREE_NODE_EXTRA_PAD_SIZE) / \ 76 (sizeof(__le64 /* dkey */) + sizeof(__le64 /* dptr */))) 77 #define NILFS_BTREE_NODE_NCHILDREN_MIN(nodesize) \ 78 ((NILFS_BTREE_NODE_NCHILDREN_MAX(nodesize) - 1) / 2 + 1) 79 #define NILFS_BTREE_KEY_MIN ((__u64)0) 80 #define NILFS_BTREE_KEY_MAX (~(__u64)0) 81 82 83 int nilfs_btree_path_cache_init(void); 84 void nilfs_btree_path_cache_destroy(void); 85 int nilfs_btree_init(struct nilfs_bmap *); 86 int nilfs_btree_convert_and_insert(struct nilfs_bmap *, __u64, __u64, 87 const __u64 *, const __u64 *, int); 88 void nilfs_btree_init_gc(struct nilfs_bmap *); 89 90 #endif /* _NILFS_BTREE_H */ 91