1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3 * NILFS meta data file prototype and definitions
4 *
5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
6 *
7 * Written by Ryusuke Konishi.
8 */
9
10 #ifndef _NILFS_MDT_H
11 #define _NILFS_MDT_H
12
13 #include <linux/buffer_head.h>
14 #include <linux/blockgroup_lock.h>
15 #include "nilfs.h"
16 #include "page.h"
17
18 /**
19 * struct nilfs_shadow_map - shadow mapping of meta data file
20 * @bmap_store: shadow copy of bmap state
21 * @inode: holder of page caches used in shadow mapping
22 * @frozen_buffers: list of frozen buffers
23 */
24 struct nilfs_shadow_map {
25 struct nilfs_bmap_store bmap_store;
26 struct inode *inode;
27 struct list_head frozen_buffers;
28 };
29
30 /**
31 * struct nilfs_mdt_info - on-memory private data of meta data files
32 * @mi_sem: reader/writer semaphore for meta data operations
33 * @mi_bgl: per-blockgroup locking
34 * @mi_entry_size: size of an entry
35 * @mi_first_entry_offset: offset to the first entry
36 * @mi_entries_per_block: number of entries in a block
37 * @mi_palloc_cache: persistent object allocator cache
38 * @mi_shadow: shadow of bmap and page caches
39 * @mi_blocks_per_group: number of blocks in a group
40 * @mi_blocks_per_desc_block: number of blocks per descriptor block
41 */
42 struct nilfs_mdt_info {
43 struct rw_semaphore mi_sem;
44 struct blockgroup_lock *mi_bgl;
45 unsigned int mi_entry_size;
46 unsigned int mi_first_entry_offset;
47 unsigned long mi_entries_per_block;
48 struct nilfs_palloc_cache *mi_palloc_cache;
49 struct nilfs_shadow_map *mi_shadow;
50 unsigned long mi_blocks_per_group;
51 unsigned long mi_blocks_per_desc_block;
52 };
53
54 static inline struct nilfs_mdt_info *NILFS_MDT(const struct inode *inode)
55 {
56 return inode->i_private;
57 }
58
59 static inline int nilfs_is_metadata_file_inode(const struct inode *inode)
60 {
61 return inode->i_private != NULL;
62 }
63
64 /* Default GFP flags using highmem */
65 #define NILFS_MDT_GFP (__GFP_RECLAIM | __GFP_IO | __GFP_HIGHMEM)
66
67 int nilfs_mdt_get_block(struct inode *, unsigned long, int,
68 void (*init_block)(struct inode *,
69 struct buffer_head *, void *),
70 struct buffer_head **);
71 int nilfs_mdt_find_block(struct inode *inode, unsigned long start,
72 unsigned long end, unsigned long *blkoff,
73 struct buffer_head **out_bh);
74 int nilfs_mdt_delete_block(struct inode *, unsigned long);
75 int nilfs_mdt_forget_block(struct inode *, unsigned long);
76 int nilfs_mdt_fetch_dirty(struct inode *);
77
78 int nilfs_mdt_init(struct inode *inode, gfp_t gfp_mask, size_t objsz);
79 void nilfs_mdt_clear(struct inode *inode);
80 void nilfs_mdt_destroy(struct inode *inode);
81
82 void nilfs_mdt_set_entry_size(struct inode *, unsigned int, unsigned int);
83
84 int nilfs_mdt_setup_shadow_map(struct inode *inode,
85 struct nilfs_shadow_map *shadow);
86 int nilfs_mdt_save_to_shadow_map(struct inode *inode);
87 void nilfs_mdt_restore_from_shadow_map(struct inode *inode);
88 void nilfs_mdt_clear_shadow_map(struct inode *inode);
89 int nilfs_mdt_freeze_buffer(struct inode *inode, struct buffer_head *bh);
90 struct buffer_head *nilfs_mdt_get_frozen_buffer(struct inode *inode,
91 struct buffer_head *bh);
92
93 static inline void nilfs_mdt_mark_dirty(struct inode *inode)
94 {
95 if (!test_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state))
96 set_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state);
97 }
98
99 static inline void nilfs_mdt_clear_dirty(struct inode *inode)
100 {
101 clear_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state);
102 }
103
104 static inline __u64 nilfs_mdt_cno(struct inode *inode)
105 {
106 return ((struct the_nilfs *)inode->i_sb->s_fs_info)->ns_cno;
107 }
108
109 static inline spinlock_t *
110 nilfs_mdt_bgl_lock(struct inode *inode, unsigned int block_group)
111 {
112 return bgl_lock_ptr(NILFS_MDT(inode)->mi_bgl, block_group);
113 }
114
115 #endif /* _NILFS_MDT_H */
116
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