fs/nilfs2/mdt.h

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