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 */
24struct 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 */
42struct 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
54static inline struct nilfs_mdt_info *NILFS_MDT(const struct inode *inode)
55{
56	return inode->i_private;
57}
58
59static 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
67int nilfs_mdt_get_block(struct inode *, unsigned long, int,
68			void (*init_block)(struct inode *,
69					   struct buffer_head *, void *),
70			struct buffer_head **);
71int nilfs_mdt_find_block(struct inode *inode, unsigned long start,
72			 unsigned long end, unsigned long *blkoff,
73			 struct buffer_head **out_bh);
74int nilfs_mdt_delete_block(struct inode *, unsigned long);
75int nilfs_mdt_forget_block(struct inode *, unsigned long);
76int nilfs_mdt_fetch_dirty(struct inode *);
77
78int nilfs_mdt_init(struct inode *inode, gfp_t gfp_mask, size_t objsz);
79void nilfs_mdt_clear(struct inode *inode);
80void nilfs_mdt_destroy(struct inode *inode);
81
82void nilfs_mdt_set_entry_size(struct inode *, unsigned int, unsigned int);
83
84int nilfs_mdt_setup_shadow_map(struct inode *inode,
85			       struct nilfs_shadow_map *shadow);
86int nilfs_mdt_save_to_shadow_map(struct inode *inode);
87void nilfs_mdt_restore_from_shadow_map(struct inode *inode);
88void nilfs_mdt_clear_shadow_map(struct inode *inode);
89int nilfs_mdt_freeze_buffer(struct inode *inode, struct buffer_head *bh);
90struct buffer_head *nilfs_mdt_get_frozen_buffer(struct inode *inode,
91						struct buffer_head *bh);
92
93static 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
99static inline void nilfs_mdt_clear_dirty(struct inode *inode)
100{
101	clear_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state);
102}
103
104static inline __u64 nilfs_mdt_cno(struct inode *inode)
105{
106	return ((struct the_nilfs *)inode->i_sb->s_fs_info)->ns_cno;
107}
108
109static inline spinlock_t *
110nilfs_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