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
NILFS_MDT(const struct inode * inode)65 static inline struct nilfs_mdt_info *NILFS_MDT(const struct inode *inode)
66 {
67 return inode->i_private;
68 }
69
nilfs_is_metadata_file_inode(const struct inode * inode)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
nilfs_mdt_mark_dirty(struct inode * inode)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
nilfs_mdt_clear_dirty(struct inode * inode)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
nilfs_mdt_cno(struct inode * inode)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 *
nilfs_mdt_bgl_lock(struct inode * inode,unsigned int block_group)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