alistair23-linux/fs/nilfs2/mdt.h
Ryusuke Konishi db38d5ad32 nilfs2: add cache framework for persistent object allocator
This adds setup and cleanup routines of the persistent object
allocator cache.

According to ftrace analyses, accessing buffers of the DAT file
suffers indispensable overhead many times.  To mitigate the overhead,
This introduce cache framework for the persistent object allocator
(palloc) which the DAT file and ifile are using.

struct nilfs_palloc_cache represents the cache object per metadata
file using palloc.

The cache is initialized through nilfs_palloc_setup_cache() and
destroyed by nilfs_palloc_destroy_cache(); callers of the former
function will be added to individual allocators of DAT and ifile on
successive patches.

nilfs_palloc_destroy_cache() will be called from nilfs_mdt_destroy()
if the cache is attached to a metadata file.  A companion function
nilfs_palloc_clear_cache() is provided to allow releasing buffer head
references independently with the cleanup task.  This adjunctive
function will be used before invalidating pages of metadata file with
the cache.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-11-20 10:05:50 +09:00

110 lines
3.6 KiB
C

/*
* 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_mdt_info - on-memory private data of meta data files
* @mi_nilfs: back pointer to the_nilfs struct
* @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_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 the_nilfs *mi_nilfs;
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;
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;
}
static inline struct the_nilfs *NILFS_I_NILFS(struct inode *inode)
{
struct super_block *sb = inode->i_sb;
return sb ? NILFS_SB(sb)->s_nilfs : NILFS_MDT(inode)->mi_nilfs;
}
/* 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 *);
struct inode *nilfs_mdt_new(struct the_nilfs *, struct super_block *, ino_t,
size_t);
struct inode *nilfs_mdt_new_common(struct the_nilfs *, struct super_block *,
ino_t, gfp_t, size_t);
void nilfs_mdt_destroy(struct inode *);
void nilfs_mdt_set_entry_size(struct inode *, unsigned, unsigned);
void nilfs_mdt_set_shadow(struct inode *, struct inode *);
#define nilfs_mdt_mark_buffer_dirty(bh) nilfs_mark_buffer_dirty(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 NILFS_MDT(inode)->mi_nilfs->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 */