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
NILFS_MDT(const struct inode * inode)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
nilfs_mdt_mark_dirty(struct inode * inode)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
nilfs_mdt_clear_dirty(struct inode * inode)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
nilfs_mdt_cno(struct inode * inode)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