1. 根目录:
2. fs
3. btrfs
4. export.h

#ifndef BTRFS_EXPORT_H
#define BTRFS_EXPORT_H

#include <linux/exportfs.h>

extern const struct export_operations btrfs_export_ops;

struct btrfs_fid {
	u64 objectid;
	u64 root_objectid;
	u32 gen;

	u64 parent_objectid;
	u32 parent_gen;

	u64 parent_root_objectid;
} __attribute__ ((packed));

#endif