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  
NILFS_MDT(const struct inode * inode)54  static inline struct nilfs_mdt_info *NILFS_MDT(const struct inode *inode)
55  {
56  	return inode->i_private;
57  }
58  
nilfs_is_metadata_file_inode(const struct inode * inode)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  
nilfs_mdt_mark_dirty(struct inode * inode)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  
nilfs_mdt_clear_dirty(struct inode * inode)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  
nilfs_mdt_cno(struct inode * inode)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 *
nilfs_mdt_bgl_lock(struct inode * inode,unsigned int block_group)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