fs/btrfs/disk-io.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (C) 2007 Oracle.  All rights reserved.
 */

#ifndef BTRFS_DISK_IO_H
#define BTRFS_DISK_IO_H

#include <linux/sizes.h>
#include <linux/compiler_types.h>
#include "ctree.h"
#include "fs.h"

struct block_device;
struct super_block;
struct extent_buffer;
struct btrfs_device;
struct btrfs_fs_devices;
struct btrfs_fs_info;
struct btrfs_super_block;
struct btrfs_trans_handle;
struct btrfs_tree_parent_check;
struct btrfs_transaction;

#define BTRFS_SUPER_MIRROR_MAX	 3
#define BTRFS_SUPER_MIRROR_SHIFT 12

/*
 * Fixed blocksize for all devices, applies to specific ways of reading
 * metadata like superblock. Must meet the set_blocksize requirements.
 *
 * Do not change.
 */
#define BTRFS_BDEV_BLOCKSIZE	(4096)

static inline u64 btrfs_sb_offset(int mirror)
{
	u64 start = SZ_16K;
	if (mirror)
		return start << (BTRFS_SUPER_MIRROR_SHIFT * mirror);
	return BTRFS_SUPER_INFO_OFFSET;
}

void btrfs_check_leaked_roots(const struct btrfs_fs_info *fs_info);
void btrfs_init_fs_info(struct btrfs_fs_info *fs_info);
struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
				      struct btrfs_tree_parent_check *check);
struct extent_buffer *btrfs_find_create_tree_block(
						struct btrfs_fs_info *fs_info,
						u64 bytenr, u64 owner_root,
						int level);
int btrfs_start_pre_rw_mount(struct btrfs_fs_info *fs_info);
int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
			   const struct btrfs_super_block *disk_sb);
int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_devices,
		      const char *options);
void __cold close_ctree(struct btrfs_fs_info *fs_info);
int btrfs_validate_super(const struct btrfs_fs_info *fs_info,
			 const struct btrfs_super_block *sb, int mirror_num);
int btrfs_check_features(struct btrfs_fs_info *fs_info, bool is_rw_mount);
int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors);
struct btrfs_super_block *btrfs_read_dev_super(struct block_device *bdev);
struct btrfs_super_block *btrfs_read_dev_one_super(struct block_device *bdev,
						   int copy_num, bool drop_cache);
int btrfs_commit_super(struct btrfs_fs_info *fs_info);
struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
					const struct btrfs_key *key);
int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
			 struct btrfs_root *root);
void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info);

struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
				     u64 objectid, bool check_ref);
struct btrfs_root *btrfs_get_new_fs_root(struct btrfs_fs_info *fs_info,
					 u64 objectid, dev_t *anon_dev);
struct btrfs_root *btrfs_get_fs_root_commit_root(struct btrfs_fs_info *fs_info,
						 struct btrfs_path *path,
						 u64 objectid);
int btrfs_global_root_insert(struct btrfs_root *root);
void btrfs_global_root_delete(struct btrfs_root *root);
struct btrfs_root *btrfs_global_root(struct btrfs_fs_info *fs_info,
				     struct btrfs_key *key);
struct btrfs_root *btrfs_csum_root(struct btrfs_fs_info *fs_info, u64 bytenr);
struct btrfs_root *btrfs_extent_root(struct btrfs_fs_info *fs_info, u64 bytenr);

void btrfs_free_fs_info(struct btrfs_fs_info *fs_info);
void btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info);
void btrfs_btree_balance_dirty_nodelay(struct btrfs_fs_info *fs_info);
void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
				 struct btrfs_root *root);
int btrfs_validate_extent_buffer(struct extent_buffer *eb,
				 const struct btrfs_tree_parent_check *check);
#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info);
#endif

/*
 * This function is used to grab the root, and avoid it is freed when we
 * access it. But it doesn't ensure that the tree is not dropped.
 *
 * If you want to ensure the whole tree is safe, you should use
 * 	fs_info->subvol_srcu
 */
static inline struct btrfs_root *btrfs_grab_root(struct btrfs_root *root)
{
	if (!root)
		return NULL;
	if (refcount_inc_not_zero(&root->refs))
		return root;
	return NULL;
}

void btrfs_put_root(struct btrfs_root *root);
void btrfs_mark_buffer_dirty(struct btrfs_trans_handle *trans,
			     struct extent_buffer *buf);
int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
			  int atomic);
int btrfs_read_extent_buffer(struct extent_buffer *buf,
			     const struct btrfs_tree_parent_check *check);

blk_status_t btree_csum_one_bio(struct btrfs_bio *bbio);
int btrfs_alloc_log_tree_node(struct btrfs_trans_handle *trans,
			      struct btrfs_root *root);
int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
			     struct btrfs_fs_info *fs_info);
int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
		       struct btrfs_root *root);
void btrfs_cleanup_dirty_bgs(struct btrfs_transaction *trans,
			     struct btrfs_fs_info *fs_info);
void btrfs_cleanup_one_transaction(struct btrfs_transaction *trans,
				  struct btrfs_fs_info *fs_info);
struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
				     u64 objectid);
int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags);
int btrfs_get_free_objectid(struct btrfs_root *root, u64 *objectid);
int btrfs_init_root_free_objectid(struct btrfs_root *root);

#endif