LXR linux/fs/nilfs2/mdt.h

   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 * Written by Ryusuke Konishi.
  17 */
  18
  19#ifndef _NILFS_MDT_H
  20#define _NILFS_MDT_H
  21
  22#include <linux/buffer_head.h>
  23#include <linux/blockgroup_lock.h>
  24#include "nilfs.h"
  25#include "page.h"
  26
  27/**
  28 * struct nilfs_shadow_map - shadow mapping of meta data file
  29 * @bmap_store: shadow copy of bmap state
  30 * @frozen_data: shadowed dirty data pages
  31 * @frozen_btnodes: shadowed dirty b-tree nodes' pages
  32 * @frozen_buffers: list of frozen buffers
  33 */
  34struct nilfs_shadow_map {
  35        struct nilfs_bmap_store bmap_store;
  36        struct address_space frozen_data;
  37        struct address_space frozen_btnodes;
  38        struct list_head frozen_buffers;
  39};
  40
  41/**
  42 * struct nilfs_mdt_info - on-memory private data of meta data files
  43 * @mi_sem: reader/writer semaphore for meta data operations
  44 * @mi_bgl: per-blockgroup locking
  45 * @mi_entry_size: size of an entry
  46 * @mi_first_entry_offset: offset to the first entry
  47 * @mi_entries_per_block: number of entries in a block
  48 * @mi_palloc_cache: persistent object allocator cache
  49 * @mi_shadow: shadow of bmap and page caches
  50 * @mi_blocks_per_group: number of blocks in a group
  51 * @mi_blocks_per_desc_block: number of blocks per descriptor block
  52 */
  53struct nilfs_mdt_info {
  54        struct rw_semaphore     mi_sem;
  55        struct blockgroup_lock *mi_bgl;
  56        unsigned int            mi_entry_size;
  57        unsigned int            mi_first_entry_offset;
  58        unsigned long           mi_entries_per_block;
  59        struct nilfs_palloc_cache *mi_palloc_cache;
  60        struct nilfs_shadow_map *mi_shadow;
  61        unsigned long           mi_blocks_per_group;
  62        unsigned long           mi_blocks_per_desc_block;
  63};
  64
  65static inline struct nilfs_mdt_info *NILFS_MDT(const struct inode *inode)
  66{
  67        return inode->i_private;
  68}
  69
  70static inline int nilfs_is_metadata_file_inode(const struct inode *inode)
  71{
  72        return inode->i_private != NULL;
  73}
  74
  75/* Default GFP flags using highmem */
  76#define NILFS_MDT_GFP      (__GFP_RECLAIM | __GFP_IO | __GFP_HIGHMEM)
  77
  78int nilfs_mdt_get_block(struct inode *, unsigned long, int,
  79                        void (*init_block)(struct inode *,
  80                                           struct buffer_head *, void *),
  81                        struct buffer_head **);
  82int nilfs_mdt_find_block(struct inode *inode, unsigned long start,
  83                         unsigned long end, unsigned long *blkoff,
  84                         struct buffer_head **out_bh);
  85int nilfs_mdt_delete_block(struct inode *, unsigned long);
  86int nilfs_mdt_forget_block(struct inode *, unsigned long);
  87int nilfs_mdt_fetch_dirty(struct inode *);
  88
  89int nilfs_mdt_init(struct inode *inode, gfp_t gfp_mask, size_t objsz);
  90void nilfs_mdt_clear(struct inode *inode);
  91void nilfs_mdt_destroy(struct inode *inode);
  92
  93void nilfs_mdt_set_entry_size(struct inode *, unsigned int, unsigned int);
  94
  95int nilfs_mdt_setup_shadow_map(struct inode *inode,
  96                               struct nilfs_shadow_map *shadow);
  97int nilfs_mdt_save_to_shadow_map(struct inode *inode);
  98void nilfs_mdt_restore_from_shadow_map(struct inode *inode);
  99void nilfs_mdt_clear_shadow_map(struct inode *inode);
 100int nilfs_mdt_freeze_buffer(struct inode *inode, struct buffer_head *bh);
 101struct buffer_head *nilfs_mdt_get_frozen_buffer(struct inode *inode,
 102                                                struct buffer_head *bh);
 103
 104static inline void nilfs_mdt_mark_dirty(struct inode *inode)
 105{
 106        if (!test_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state))
 107                set_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state);
 108}
 109
 110static inline void nilfs_mdt_clear_dirty(struct inode *inode)
 111{
 112        clear_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state);
 113}
 114
 115static inline __u64 nilfs_mdt_cno(struct inode *inode)
 116{
 117        return ((struct the_nilfs *)inode->i_sb->s_fs_info)->ns_cno;
 118}
 119
 120static inline spinlock_t *
 121nilfs_mdt_bgl_lock(struct inode *inode, unsigned int block_group)
 122{
 123        return bgl_lock_ptr(NILFS_MDT(inode)->mi_bgl, block_group);
 124}
 125
 126#endif /* _NILFS_MDT_H */
 127