kernel-ark/fs/nilfs2/alloc.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

94 lines
3.3 KiB
C

/*
* alloc.h - persistent object (dat entry/disk inode) allocator/deallocator
*
* Copyright (C) 2006-2008 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
*
* Original code was written by Koji Sato <koji@osrg.net>.
* Two allocators were unified by Ryusuke Konishi <ryusuke@osrg.net>,
* Amagai Yoshiji <amagai@osrg.net>.
*/
#ifndef _NILFS_ALLOC_H
#define _NILFS_ALLOC_H
#include <linux/types.h>
#include <linux/buffer_head.h>
#include <linux/fs.h>
static inline unsigned long
nilfs_palloc_entries_per_group(const struct inode *inode)
{
return 1UL << (inode->i_blkbits + 3 /* log2(8 = CHAR_BITS) */);
}
int nilfs_palloc_init_blockgroup(struct inode *, unsigned);
int nilfs_palloc_get_entry_block(struct inode *, __u64, int,
struct buffer_head **);
void *nilfs_palloc_block_get_entry(const struct inode *, __u64,
const struct buffer_head *, void *);
/**
* nilfs_palloc_req - persistent alloctor request and reply
* @pr_entry_nr: entry number (vblocknr or inode number)
* @pr_desc_bh: buffer head of the buffer containing block group descriptors
* @pr_bitmap_bh: buffer head of the buffer containing a block group bitmap
* @pr_entry_bh: buffer head of the buffer containing translation entries
*/
struct nilfs_palloc_req {
__u64 pr_entry_nr;
struct buffer_head *pr_desc_bh;
struct buffer_head *pr_bitmap_bh;
struct buffer_head *pr_entry_bh;
};
int nilfs_palloc_prepare_alloc_entry(struct inode *,
struct nilfs_palloc_req *);
void nilfs_palloc_commit_alloc_entry(struct inode *,
struct nilfs_palloc_req *);
void nilfs_palloc_abort_alloc_entry(struct inode *, struct nilfs_palloc_req *);
void nilfs_palloc_commit_free_entry(struct inode *, struct nilfs_palloc_req *);
int nilfs_palloc_prepare_free_entry(struct inode *, struct nilfs_palloc_req *);
void nilfs_palloc_abort_free_entry(struct inode *, struct nilfs_palloc_req *);
int nilfs_palloc_freev(struct inode *, __u64 *, size_t);
#define nilfs_set_bit_atomic ext2_set_bit_atomic
#define nilfs_clear_bit_atomic ext2_clear_bit_atomic
#define nilfs_find_next_zero_bit ext2_find_next_zero_bit
/*
* persistent object allocator cache
*/
struct nilfs_bh_assoc {
unsigned long blkoff;
struct buffer_head *bh;
};
struct nilfs_palloc_cache {
spinlock_t lock;
struct nilfs_bh_assoc prev_desc;
struct nilfs_bh_assoc prev_bitmap;
struct nilfs_bh_assoc prev_entry;
};
void nilfs_palloc_setup_cache(struct inode *inode,
struct nilfs_palloc_cache *cache);
void nilfs_palloc_clear_cache(struct inode *inode);
void nilfs_palloc_destroy_cache(struct inode *inode);
#endif /* _NILFS_ALLOC_H */