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 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, write to the Free Software
  18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19 *
  20 * Written by Ryusuke Konishi <ryusuke@osrg.net>
  21 */
  22
  23#ifndef _NILFS_MDT_H
  24#define _NILFS_MDT_H
  25
  26#include <linux/buffer_head.h>
  27#include <linux/blockgroup_lock.h>
  28#include "nilfs.h"
  29#include "page.h"
  30
  31/**
  32 * struct nilfs_shadow_map - shadow mapping of meta data file
  33 * @bmap_store: shadow copy of bmap state
  34 * @frozen_data: shadowed dirty data pages
  35 * @frozen_btnodes: shadowed dirty b-tree nodes' pages
  36 * @frozen_buffers: list of frozen buffers
  37 */
  38struct nilfs_shadow_map {
  39        struct nilfs_bmap_store bmap_store;
  40        struct address_space frozen_data;
  41        struct address_space frozen_btnodes;
  42        struct list_head frozen_buffers;
  43};
  44
  45/**
  46 * struct nilfs_mdt_info - on-memory private data of meta data files
  47 * @mi_sem: reader/writer semaphore for meta data operations
  48 * @mi_bgl: per-blockgroup locking
  49 * @mi_entry_size: size of an entry
  50 * @mi_first_entry_offset: offset to the first entry
  51 * @mi_entries_per_block: number of entries in a block
  52 * @mi_palloc_cache: persistent object allocator cache
  53 * @mi_shadow: shadow of bmap and page caches
  54 * @mi_blocks_per_group: number of blocks in a group
  55 * @mi_blocks_per_desc_block: number of blocks per descriptor block
  56 */
  57struct nilfs_mdt_info {
  58        struct rw_semaphore     mi_sem;
  59        struct blockgroup_lock *mi_bgl;
  60        unsigned                mi_entry_size;
  61        unsigned                mi_first_entry_offset;
  62        unsigned long           mi_entries_per_block;
  63        struct nilfs_palloc_cache *mi_palloc_cache;
  64        struct nilfs_shadow_map *mi_shadow;
  65        unsigned long           mi_blocks_per_group;
  66        unsigned long           mi_blocks_per_desc_block;
  67};
  68
  69static inline struct nilfs_mdt_info *NILFS_MDT(const struct inode *inode)
  70{
  71        return inode->i_private;
  72}
  73
  74/* Default GFP flags using highmem */
  75#define NILFS_MDT_GFP      (__GFP_WAIT | __GFP_IO | __GFP_HIGHMEM)
  76
  77int nilfs_mdt_get_block(struct inode *, unsigned long, int,
  78                        void (*init_block)(struct inode *,
  79                                           struct buffer_head *, void *),
  80                        struct buffer_head **);
  81int nilfs_mdt_delete_block(struct inode *, unsigned long);
  82int nilfs_mdt_forget_block(struct inode *, unsigned long);
  83int nilfs_mdt_mark_block_dirty(struct inode *, unsigned long);
  84int nilfs_mdt_fetch_dirty(struct inode *);
  85
  86int nilfs_mdt_init(struct inode *inode, gfp_t gfp_mask, size_t objsz);
  87void nilfs_mdt_set_entry_size(struct inode *, unsigned, unsigned);
  88
  89int nilfs_mdt_setup_shadow_map(struct inode *inode,
  90                               struct nilfs_shadow_map *shadow);
  91int nilfs_mdt_save_to_shadow_map(struct inode *inode);
  92void nilfs_mdt_restore_from_shadow_map(struct inode *inode);
  93void nilfs_mdt_clear_shadow_map(struct inode *inode);
  94int nilfs_mdt_freeze_buffer(struct inode *inode, struct buffer_head *bh);
  95struct buffer_head *nilfs_mdt_get_frozen_buffer(struct inode *inode,
  96                                                struct buffer_head *bh);
  97
  98static inline void nilfs_mdt_mark_dirty(struct inode *inode)
  99{
 100        if (!test_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state))
 101                set_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state);
 102}
 103
 104static inline void nilfs_mdt_clear_dirty(struct inode *inode)
 105{
 106        clear_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state);
 107}
 108
 109static inline __u64 nilfs_mdt_cno(struct inode *inode)
 110{
 111        return ((struct the_nilfs *)inode->i_sb->s_fs_info)->ns_cno;
 112}
 113
 114#define nilfs_mdt_bgl_lock(inode, bg) \
 115        (&NILFS_MDT(inode)->mi_bgl->locks[(bg) & (NR_BG_LOCKS-1)].lock)
 116
 117#endif /* _NILFS_MDT_H */
 118