Btrfs: Add O_DIRECT read and write (writes == buffered + cache flush)

[linux-block.git] / fs / btrfs / disk-io.h

/*
 * Copyright (C) 2007 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 __DISKIO__
#define __DISKIO__

#define BTRFS_SUPER_INFO_OFFSET (16 * 1024)
struct btrfs_device;
struct btrfs_fs_devices;

struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
				      u32 blocksize);
int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize);
struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
						   u64 bytenr, u32 blocksize);
int clean_tree_block(struct btrfs_trans_handle *trans,
		     struct btrfs_root *root, struct extent_buffer *buf);
struct btrfs_root *open_ctree(struct super_block *sb,
			      struct btrfs_fs_devices *fs_devices);
int close_ctree(struct btrfs_root *root);
int write_ctree_super(struct btrfs_trans_handle *trans,
		      struct btrfs_root *root);
struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
					    u64 bytenr, u32 blocksize);
struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
					u64 root_objectid);
struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
				      struct btrfs_key *location,
				      const char *name, int namelen);
struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_fs_info *fs_info,
					       struct btrfs_key *location);
struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
					      struct btrfs_key *location);
int btrfs_insert_dev_radix(struct btrfs_root *root,
			   struct block_device *bdev,
			   u64 device_id,
			   u64 block_start,
			   u64 num_blocks);
void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr);
int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root);
void btrfs_mark_buffer_dirty(struct extent_buffer *buf);
int btrfs_buffer_uptodate(struct extent_buffer *buf);
int btrfs_set_buffer_uptodate(struct extent_buffer *buf);
int wait_on_tree_block_writeback(struct btrfs_root *root,
				 struct extent_buffer *buf);
void btrfs_set_buffer_defrag(struct extent_buffer *buf);
void btrfs_set_buffer_defrag_done(struct extent_buffer *buf);
int btrfs_buffer_defrag(struct extent_buffer *buf);
int btrfs_buffer_defrag_done(struct extent_buffer *buf);
int btrfs_clear_buffer_defrag(struct extent_buffer *buf);
int btrfs_clear_buffer_defrag_done(struct extent_buffer *buf);
int btrfs_read_buffer(struct extent_buffer *buf);
u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len);
void btrfs_csum_final(u32 crc, char *result);
void btrfs_throttle(struct btrfs_root *root);
int btrfs_open_device(struct btrfs_device *dev);
int btrfs_verify_block_csum(struct btrfs_root *root,
			    struct extent_buffer *buf);
int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
			int metadata);
#endif