1 /* 2 * mdt.h - NILFS meta data file prototype and definitions 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 Ryusuke Konishi <ryusuke@osrg.net> 21 */ 22 23 #ifndef _NILFS_MDT_H 24 #define _NILFS_MDT_H 25 26 #include <linux/buffer_head.h> 27 #include <linux/blockgroup_lock.h> 28 #include "nilfs.h" 29 #include "page.h" 30 31 /** 32 * struct nilfs_shadow_map - shadow mapping of meta data file 33 * @bmap_store: shadow copy of bmap state 34 * @frozen_data: shadowed dirty data pages 35 * @frozen_btnodes: shadowed dirty b-tree nodes' pages 36 * @frozen_buffers: list of frozen buffers 37 */ 38 struct nilfs_shadow_map { 39 struct nilfs_bmap_store bmap_store; 40 struct address_space frozen_data; 41 struct address_space frozen_btnodes; 42 struct list_head frozen_buffers; 43 }; 44 45 /** 46 * struct nilfs_mdt_info - on-memory private data of meta data files 47 * @mi_sem: reader/writer semaphore for meta data operations 48 * @mi_bgl: per-blockgroup locking 49 * @mi_entry_size: size of an entry 50 * @mi_first_entry_offset: offset to the first entry 51 * @mi_entries_per_block: number of entries in a block 52 * @mi_palloc_cache: persistent object allocator cache 53 * @mi_shadow: shadow of bmap and page caches 54 * @mi_blocks_per_group: number of blocks in a group 55 * @mi_blocks_per_desc_block: number of blocks per descriptor block 56 */ 57 struct nilfs_mdt_info { 58 struct rw_semaphore mi_sem; 59 struct blockgroup_lock *mi_bgl; 60 unsigned mi_entry_size; 61 unsigned mi_first_entry_offset; 62 unsigned long mi_entries_per_block; 63 struct nilfs_palloc_cache *mi_palloc_cache; 64 struct nilfs_shadow_map *mi_shadow; 65 unsigned long mi_blocks_per_group; 66 unsigned long mi_blocks_per_desc_block; 67 }; 68 69 static inline struct nilfs_mdt_info *NILFS_MDT(const struct inode *inode) 70 { 71 return inode->i_private; 72 } 73 74 /* Default GFP flags using highmem */ 75 #define NILFS_MDT_GFP (__GFP_WAIT | __GFP_IO | __GFP_HIGHMEM) 76 77 int nilfs_mdt_get_block(struct inode *, unsigned long, int, 78 void (*init_block)(struct inode *, 79 struct buffer_head *, void *), 80 struct buffer_head **); 81 int nilfs_mdt_delete_block(struct inode *, unsigned long); 82 int nilfs_mdt_forget_block(struct inode *, unsigned long); 83 int nilfs_mdt_mark_block_dirty(struct inode *, unsigned long); 84 int nilfs_mdt_fetch_dirty(struct inode *); 85 86 int nilfs_mdt_init(struct inode *inode, gfp_t gfp_mask, size_t objsz); 87 void nilfs_mdt_set_entry_size(struct inode *, unsigned, unsigned); 88 89 int nilfs_mdt_setup_shadow_map(struct inode *inode, 90 struct nilfs_shadow_map *shadow); 91 int nilfs_mdt_save_to_shadow_map(struct inode *inode); 92 void nilfs_mdt_restore_from_shadow_map(struct inode *inode); 93 void nilfs_mdt_clear_shadow_map(struct inode *inode); 94 int nilfs_mdt_freeze_buffer(struct inode *inode, struct buffer_head *bh); 95 struct buffer_head *nilfs_mdt_get_frozen_buffer(struct inode *inode, 96 struct buffer_head *bh); 97 98 static inline void nilfs_mdt_mark_dirty(struct inode *inode) 99 { 100 if (!test_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state)) 101 set_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state); 102 } 103 104 static inline void nilfs_mdt_clear_dirty(struct inode *inode) 105 { 106 clear_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state); 107 } 108 109 static inline __u64 nilfs_mdt_cno(struct inode *inode) 110 { 111 return ((struct the_nilfs *)inode->i_sb->s_fs_info)->ns_cno; 112 } 113 114 #define nilfs_mdt_bgl_lock(inode, bg) \ 115 (&NILFS_MDT(inode)->mi_bgl->locks[(bg) & (NR_BG_LOCKS-1)].lock) 116 117 #endif /* _NILFS_MDT_H */ 118