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