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/*
* 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>
/**
* nilfs_palloc_entries_per_group - get the number of entries per group
* @inode: inode of metadata file using this allocator
*
* The number of entries per group is defined by the number of bits
* that a bitmap block can maintain.
*/
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 allocator 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 find_next_zero_bit_le
/**
* struct nilfs_bh_assoc - block offset and buffer head association
* @blkoff: block offset
* @bh: buffer head
*/
struct nilfs_bh_assoc {
unsigned long blkoff;
struct buffer_head *bh;
};
/**
* struct nilfs_palloc_cache - persistent object allocator cache
* @lock: cache protecting lock
* @prev_desc: blockgroup descriptors cache
* @prev_bitmap: blockgroup bitmap cache
* @prev_entry: translation entries cache
*/
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 */
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