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/*
* mdt.h - NILFS meta data file prototype and definitions
*
* Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Written by Ryusuke Konishi <ryusuke@osrg.net>
*/
#ifndef _NILFS_MDT_H
#define _NILFS_MDT_H
#include <linux/buffer_head.h>
#include <linux/blockgroup_lock.h>
#include "nilfs.h"
#include "page.h"
/**
* struct nilfs_shadow_map - shadow mapping of meta data file
* @bmap_store: shadow copy of bmap state
* @frozen_data: shadowed dirty data pages
* @frozen_btnodes: shadowed dirty b-tree nodes' pages
* @frozen_buffers: list of frozen buffers
*/
struct nilfs_shadow_map {
struct nilfs_bmap_store bmap_store;
struct address_space frozen_data;
struct address_space frozen_btnodes;
struct list_head frozen_buffers;
};
/**
* struct nilfs_mdt_info - on-memory private data of meta data files
* @mi_sem: reader/writer semaphore for meta data operations
* @mi_bgl: per-blockgroup locking
* @mi_entry_size: size of an entry
* @mi_first_entry_offset: offset to the first entry
* @mi_entries_per_block: number of entries in a block
* @mi_palloc_cache: persistent object allocator cache
* @mi_shadow: shadow of bmap and page caches
* @mi_blocks_per_group: number of blocks in a group
* @mi_blocks_per_desc_block: number of blocks per descriptor block
*/
struct nilfs_mdt_info {
struct rw_semaphore mi_sem;
struct blockgroup_lock *mi_bgl;
unsigned mi_entry_size;
unsigned mi_first_entry_offset;
unsigned long mi_entries_per_block;
struct nilfs_palloc_cache *mi_palloc_cache;
struct nilfs_shadow_map *mi_shadow;
unsigned long mi_blocks_per_group;
unsigned long mi_blocks_per_desc_block;
};
static inline struct nilfs_mdt_info *NILFS_MDT(const struct inode *inode)
{
return inode->i_private;
}
/* Default GFP flags using highmem */
#define NILFS_MDT_GFP (__GFP_WAIT | __GFP_IO | __GFP_HIGHMEM)
int nilfs_mdt_get_block(struct inode *, unsigned long, int,
void (*init_block)(struct inode *,
struct buffer_head *, void *),
struct buffer_head **);
int nilfs_mdt_delete_block(struct inode *, unsigned long);
int nilfs_mdt_forget_block(struct inode *, unsigned long);
int nilfs_mdt_mark_block_dirty(struct inode *, unsigned long);
int nilfs_mdt_fetch_dirty(struct inode *);
int nilfs_mdt_init(struct inode *inode, gfp_t gfp_mask, size_t objsz);
void nilfs_mdt_set_entry_size(struct inode *, unsigned, unsigned);
int nilfs_mdt_setup_shadow_map(struct inode *inode,
struct nilfs_shadow_map *shadow);
int nilfs_mdt_save_to_shadow_map(struct inode *inode);
void nilfs_mdt_restore_from_shadow_map(struct inode *inode);
void nilfs_mdt_clear_shadow_map(struct inode *inode);
int nilfs_mdt_freeze_buffer(struct inode *inode, struct buffer_head *bh);
struct buffer_head *nilfs_mdt_get_frozen_buffer(struct inode *inode,
struct buffer_head *bh);
static inline void nilfs_mdt_mark_dirty(struct inode *inode)
{
if (!test_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state))
set_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state);
}
static inline void nilfs_mdt_clear_dirty(struct inode *inode)
{
clear_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state);
}
static inline __u64 nilfs_mdt_cno(struct inode *inode)
{
return ((struct the_nilfs *)inode->i_sb->s_fs_info)->ns_cno;
}
#define nilfs_mdt_bgl_lock(inode, bg) \
(&NILFS_MDT(inode)->mi_bgl->locks[(bg) & (NR_BG_LOCKS-1)].lock)
#endif /* _NILFS_MDT_H */
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