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 * Written by Ryusuke Konishi. 17 */ 18 19 #ifndef _NILFS_MDT_H 20 #define _NILFS_MDT_H 21 22 #include <linux/buffer_head.h> 23 #include <linux/blockgroup_lock.h> 24 #include "nilfs.h" 25 #include "page.h" 26 27 /** 28 * struct nilfs_shadow_map - shadow mapping of meta data file 29 * @bmap_store: shadow copy of bmap state 30 * @frozen_data: shadowed dirty data pages 31 * @frozen_btnodes: shadowed dirty b-tree nodes' pages 32 * @frozen_buffers: list of frozen buffers 33 */ 34 struct nilfs_shadow_map { 35 struct nilfs_bmap_store bmap_store; 36 struct address_space frozen_data; 37 struct address_space frozen_btnodes; 38 struct list_head frozen_buffers; 39 }; 40 41 /** 42 * struct nilfs_mdt_info - on-memory private data of meta data files 43 * @mi_sem: reader/writer semaphore for meta data operations 44 * @mi_bgl: per-blockgroup locking 45 * @mi_entry_size: size of an entry 46 * @mi_first_entry_offset: offset to the first entry 47 * @mi_entries_per_block: number of entries in a block 48 * @mi_palloc_cache: persistent object allocator cache 49 * @mi_shadow: shadow of bmap and page caches 50 * @mi_blocks_per_group: number of blocks in a group 51 * @mi_blocks_per_desc_block: number of blocks per descriptor block 52 */ 53 struct nilfs_mdt_info { 54 struct rw_semaphore mi_sem; 55 struct blockgroup_lock *mi_bgl; 56 unsigned int mi_entry_size; 57 unsigned int mi_first_entry_offset; 58 unsigned long mi_entries_per_block; 59 struct nilfs_palloc_cache *mi_palloc_cache; 60 struct nilfs_shadow_map *mi_shadow; 61 unsigned long mi_blocks_per_group; 62 unsigned long mi_blocks_per_desc_block; 63 }; 64 65 static inline struct nilfs_mdt_info *NILFS_MDT(const struct inode *inode) 66 { 67 return inode->i_private; 68 } 69 70 static inline int nilfs_is_metadata_file_inode(const struct inode *inode) 71 { 72 return inode->i_private != NULL; 73 } 74 75 /* Default GFP flags using highmem */ 76 #define NILFS_MDT_GFP (__GFP_RECLAIM | __GFP_IO | __GFP_HIGHMEM) 77 78 int nilfs_mdt_get_block(struct inode *, unsigned long, int, 79 void (*init_block)(struct inode *, 80 struct buffer_head *, void *), 81 struct buffer_head **); 82 int nilfs_mdt_find_block(struct inode *inode, unsigned long start, 83 unsigned long end, unsigned long *blkoff, 84 struct buffer_head **out_bh); 85 int nilfs_mdt_delete_block(struct inode *, unsigned long); 86 int nilfs_mdt_forget_block(struct inode *, unsigned long); 87 int nilfs_mdt_fetch_dirty(struct inode *); 88 89 int nilfs_mdt_init(struct inode *inode, gfp_t gfp_mask, size_t objsz); 90 void nilfs_mdt_clear(struct inode *inode); 91 void nilfs_mdt_destroy(struct inode *inode); 92 93 void nilfs_mdt_set_entry_size(struct inode *, unsigned int, unsigned int); 94 95 int nilfs_mdt_setup_shadow_map(struct inode *inode, 96 struct nilfs_shadow_map *shadow); 97 int nilfs_mdt_save_to_shadow_map(struct inode *inode); 98 void nilfs_mdt_restore_from_shadow_map(struct inode *inode); 99 void nilfs_mdt_clear_shadow_map(struct inode *inode); 100 int nilfs_mdt_freeze_buffer(struct inode *inode, struct buffer_head *bh); 101 struct buffer_head *nilfs_mdt_get_frozen_buffer(struct inode *inode, 102 struct buffer_head *bh); 103 104 static inline void nilfs_mdt_mark_dirty(struct inode *inode) 105 { 106 if (!test_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state)) 107 set_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state); 108 } 109 110 static inline void nilfs_mdt_clear_dirty(struct inode *inode) 111 { 112 clear_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state); 113 } 114 115 static inline __u64 nilfs_mdt_cno(struct inode *inode) 116 { 117 return ((struct the_nilfs *)inode->i_sb->s_fs_info)->ns_cno; 118 } 119 120 static inline spinlock_t * 121 nilfs_mdt_bgl_lock(struct inode *inode, unsigned int block_group) 122 { 123 return bgl_lock_ptr(NILFS_MDT(inode)->mi_bgl, block_group); 124 } 125 126 #endif /* _NILFS_MDT_H */ 127