| Koji Sato | 17c76b0 | 2009-04-06 19:01:24 -0700 | [diff] [blame] | 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 */ |