1. 根目录:
2. fs
3. btrfs
4. free-space-cache.h

/*
 * Copyright (C) 2009 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * 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., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#ifndef __BTRFS_FREE_SPACE_CACHE
#define __BTRFS_FREE_SPACE_CACHE

struct btrfs_free_space {
	struct rb_node offset_index;
	u64 offset;
	u64 bytes;
	unsigned long *bitmap;
	struct list_head list;
};

struct inode *lookup_free_space_inode(struct btrfs_root *root,
				      struct btrfs_block_group_cache
				      *block_group, struct btrfs_path *path);
int create_free_space_inode(struct btrfs_root *root,
			    struct btrfs_trans_handle *trans,
			    struct btrfs_block_group_cache *block_group,
			    struct btrfs_path *path);

int btrfs_truncate_free_space_cache(struct btrfs_root *root,
				    struct btrfs_trans_handle *trans,
				    struct btrfs_path *path,
				    struct inode *inode);
int load_free_space_cache(struct btrfs_fs_info *fs_info,
			  struct btrfs_block_group_cache *block_group);
int btrfs_write_out_cache(struct btrfs_root *root,
			  struct btrfs_trans_handle *trans,
			  struct btrfs_block_group_cache *block_group,
			  struct btrfs_path *path);
int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
			 u64 bytenr, u64 size);
int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
			    u64 bytenr, u64 size);
void btrfs_remove_free_space_cache(struct btrfs_block_group_cache
				   *block_group);
u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
			       u64 offset, u64 bytes, u64 empty_size);
void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group,
			   u64 bytes);
u64 btrfs_block_group_free_space(struct btrfs_block_group_cache *block_group);
int btrfs_find_space_cluster(struct btrfs_trans_handle *trans,
			     struct btrfs_root *root,
			     struct btrfs_block_group_cache *block_group,
			     struct btrfs_free_cluster *cluster,
			     u64 offset, u64 bytes, u64 empty_size);
void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster);
u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
			     struct btrfs_free_cluster *cluster, u64 bytes,
			     u64 min_start);
int btrfs_return_cluster_to_free_space(
			       struct btrfs_block_group_cache *block_group,
			       struct btrfs_free_cluster *cluster);
int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
			   u64 *trimmed, u64 start, u64 end, u64 minlen);
#endif