diff options
Diffstat (limited to 'include/btrfs.h')
| -rw-r--r-- | include/btrfs.h | 417 |
1 files changed, 417 insertions, 0 deletions
diff --git a/include/btrfs.h b/include/btrfs.h new file mode 100644 index 0000000000..62466702ae --- /dev/null +++ b/include/btrfs.h @@ -0,0 +1,417 @@ +#ifndef _BTRFS_H_ +#define _BTRFS_H_ + +#include <asm/byteorder.h> +/* type that store on disk, but it is same as cpu type for i386 arch */ + +#define BTRFS_CURRENTDIR_MAX 15 +#define BTRFS_MAX_OPEN 5 +#define BTRFS_FILENAME_MAX 20 +#define BTRFS_MAX_SYMLINK_CNT 20 +#define BTRFS_MAX_SYMLINK_BUF 4096 +#define BTRFS_SECTOR_SHIFT(fs) ((fs)->sector_shift) +#define BTRFS_IFTODT(mode) (((mode) & 0170000) >> 12) +#define BTRFS_SECTOR_SIZE 0x200 +#define BTRFS_SECTOR_BITS 9 +#define BTRFS_EXTENT_ZERO ((uint32_t)-1) /* All-zero extent */ +#define BTRFS_EXTENT_VOID ((uint32_t)-2) /* Invalid information */ +#define BTRFS_DT_LNK 10 +#define BTRFS_DT_REG 8 +#define BTRFS_DT_DIR 4 +#define EXTENT_SPECIAL(x) ((x) >= BTRFS_EXTENT_VOID) +#define BTRFS_MAX_SUBVOL_NAME 50 + +#define BTRFS_FILE 1 +#define BTRFS_DIR 2 +#define BTRFS_SYMLNK 7 +#define BTRFS_SS BTRFS_SECTOR_SIZE + +extern char subvolname[BTRFS_MAX_SUBVOL_NAME]; +struct _DIR_; + +struct com32_filedata { + size_t size; /* File size */ + int blocklg2; /* log2(block size) */ + uint16_t handle; /* File handle */ +}; + +struct btrfs_info { + const struct fs_ops *fs_ops; + struct device *fs_dev; + void *btrfs_info; /* The fs-specific information */ + int sector_shift, sector_size; + int block_shift, block_size; + struct inode *root, *cwd; /* Root and current directories */ + char cwd_name[BTRFS_CURRENTDIR_MAX]; /* Current directory by name */ +}; +/* + * Extent structure: contains the mapping of some chunk of a file + * that is contiguous on disk. + */ +struct extent { + uint64_t pstart; + uint32_t lstart; /* Logical start sector */ + uint32_t len; /* Number of contiguous sectors */ +} __packed; + + +struct inode { + struct btrfs_info *fs; /* The filesystem inode is associated with */ + struct inode *parent; /* Parent directory, if any */ + const u8 *name; /* Name, valid for generic path search only */ + uint32_t refcnt; + uint32_t mode; /* FILE , DIR or SYMLINK */ + uint32_t size; + uint32_t blocks; /* How many blocks the file take */ + uint32_t ino; /* Inode number */ + uint32_t atime; /* Access time */ + uint32_t mtime; /* Modify time */ + uint32_t ctime; /* Create time */ + uint32_t dtime; /* Delete time */ + uint32_t flags; + uint32_t file_acl; + struct extent this_extent, next_extent; + u8 pvt[0]; /* Private filesystem data */ +} __packed; +struct file { + struct btrfs_info *fs; + uint64_t offset; /* for next read */ + struct inode *inode; /* The file-specific information */ +} __packed; + +#define NAME_MAX 20 +struct btrfs_dirent { + uint32_t d_ino; + uint32_t d_off; + uint16_t d_reclen; + uint16_t d_type; + char d_name[NAME_MAX + 1]; +}; + +#define btrfs_crc32c crc32c_le + +#define BTRFS_SUPER_INFO_OFFSET (64 * 1024) +#define BTRFS_SUPER_INFO_SIZE 4096 +#define BTRFS_MAX_LEAF_SIZE 4096 +#define BTRFS_BLOCK_SHIFT 12 + +#define BTRFS_SUPER_MIRROR_MAX 3 +#define BTRFS_SUPER_MIRROR_SHIFT 12 +#define BTRFS_CSUM_SIZE 32 +#define BTRFS_FSID_SIZE 16 +#define BTRFS_LABEL_SIZE 256 +#define BTRFS_SYSTEM_CHUNK_ARRAY_SIZE 2048 +#define BTRFS_UUID_SIZE 16 + +#define BTRFS_MAGIC "_BHRfS_M" + +#define BTRFS_SUPER_FLAG_METADUMP (1ULL << 33) + +#define BTRFS_DEV_ITEM_KEY 216 +#define BTRFS_CHUNK_ITEM_KEY 228 +#define BTRFS_ROOT_REF_KEY 156 +#define BTRFS_ROOT_ITEM_KEY 132 +#define BTRFS_EXTENT_DATA_KEY 108 +#define BTRFS_DIR_ITEM_KEY 84 +#define BTRFS_INODE_ITEM_KEY 1 + +#define BTRFS_EXTENT_TREE_OBJECTID 2ULL +#define BTRFS_FS_TREE_OBJECTID 5ULL + +#define BTRFS_FIRST_CHUNK_TREE_OBJECTID 256ULL + +#define BTRFS_FILE_EXTENT_INLINE 0 +#define BTRFS_FILE_EXTENT_REG 1 +#define BTRFS_FILE_EXTENT_PREALLOC 2 + +#define BTRFS_MAX_LEVEL 8 +#define BTRFS_MAX_CHUNK_ENTRIES 256 + +#define BTRFS_FT_REG_FILE 1 +#define BTRFS_FT_DIR 2 +#define BTRFS_FT_SYMLINK 7 + +#define ROOT_DIR_WORD 0x002f + +struct btrfs_dev_item { + uint64_t devid; + uint64_t total_bytes; + uint64_t bytes_used; + uint32_t io_align; + uint32_t io_width; + uint32_t sector_size; + uint64_t type; + uint64_t generation; + uint64_t start_offset; + uint32_t dev_group; + u8 seek_speed; + u8 bandwidth; + u8 uuid[BTRFS_UUID_SIZE]; + u8 fsid[BTRFS_UUID_SIZE]; +} __packed; + +struct btrfs_super_block { + u8 csum[BTRFS_CSUM_SIZE]; + /* the first 4 fields must match struct btrfs_header */ + u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */ + uint64_t bytenr; /* this block number */ + uint64_t flags; + + /* allowed to be different from the btrfs_header from here own down */ + uint64_t magic; + uint64_t generation; + uint64_t root; + uint64_t chunk_root; + uint64_t log_root; + + /* this will help find the new super based on the log root */ + uint64_t log_root_transid; + uint64_t total_bytes; + uint64_t bytes_used; + uint64_t root_dir_objectid; + uint64_t num_devices; + uint32_t sectorsize; + uint32_t nodesize; + uint32_t leafsize; + uint32_t stripesize; + uint32_t sys_chunk_array_size; + uint64_t chunk_root_generation; + uint64_t compat_flags; + uint64_t compat_ro_flags; + uint64_t incompat_flags; + __le16 csum_type; + u8 root_level; + u8 chunk_root_level; + u8 log_root_level; + struct btrfs_dev_item dev_item; + + char label[BTRFS_LABEL_SIZE]; + + uint64_t cache_generation; + + /* future expansion */ + uint64_t reserved[31]; + u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE]; +} __packed; + +struct btrfs_disk_key { + uint64_t objectid; + u8 type; + uint64_t offset; +} __packed; + +struct btrfs_stripe { + uint64_t devid; + uint64_t offset; + u8 dev_uuid[BTRFS_UUID_SIZE]; +} __packed; + +struct btrfs_chunk { + uint64_t length; + uint64_t owner; + uint64_t stripe_len; + uint64_t type; + uint32_t io_align; + uint32_t io_width; + uint32_t sector_size; + __le16 num_stripes; + __le16 sub_stripes; + struct btrfs_stripe stripe; +} __packed; + +struct btrfs_header { + /* these first four must match the super block */ + u8 csum[BTRFS_CSUM_SIZE]; + u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */ + uint64_t bytenr; /* which block this node is supposed to live in */ + uint64_t flags; + + /* allowed to be different from the super from here on down */ + u8 chunk_tree_uuid[BTRFS_UUID_SIZE]; + uint64_t generation; + uint64_t owner; + uint32_t nritems; + u8 level; +} __packed; + +struct btrfs_item { + struct btrfs_disk_key key; + uint32_t offset; + uint32_t size; +} __packed; + +struct btrfs_leaf { + struct btrfs_header header; + struct btrfs_item items[]; +} __packed; + +struct btrfs_key_ptr { + struct btrfs_disk_key key; + uint64_t blockptr; + uint64_t generation; +} __packed; + +struct btrfs_node { + struct btrfs_header header; + struct btrfs_key_ptr ptrs[]; +} __packed; + +/* remember how we get to a node/leaf */ +struct btrfs_path { + uint64_t offsets[BTRFS_MAX_LEVEL]; + uint32_t itemsnr[BTRFS_MAX_LEVEL]; + uint32_t slots[BTRFS_MAX_LEVEL]; + /* remember last slot's item and data */ + struct btrfs_item item; + u32 data[BTRFS_MAX_LEAF_SIZE]; +}; + +/* store logical offset to physical offset mapping */ +struct btrfs_chunk_map_item { + uint64_t logical; + uint64_t length; + uint64_t devid; + uint64_t physical; +}; + +struct btrfs_chunk_map { + struct btrfs_chunk_map_item *map; + uint32_t map_length; + uint32_t cur_length; +}; + +struct btrfs_timespec { + uint64_t sec; + uint32_t nsec; +} __packed; + +struct btrfs_inode_item { + /* nfs style generation number */ + uint64_t generation; + /* transid that last touched this inode */ + uint64_t transid; + uint64_t size; + uint64_t nbytes; + uint64_t block_group; + uint32_t nlink; + uint32_t uid; + uint32_t gid; + uint32_t mode; + uint64_t rdev; + uint64_t flags; + + /* modification sequence number for NFS */ + uint64_t sequence; + + /* + * a little future expansion, for more than this we can + * just grow the inode item and version it + */ + uint64_t reserved[4]; + struct btrfs_timespec atime; + struct btrfs_timespec ctime; + struct btrfs_timespec mtime; + struct btrfs_timespec otime; +} __packed; + +struct btrfs_root_item { + struct btrfs_inode_item inode; + uint64_t generation; + uint64_t root_dirid; + uint64_t bytenr; + uint64_t byte_limit; + uint64_t bytes_used; + uint64_t last_snapshot; + uint64_t flags; + uint32_t refs; + struct btrfs_disk_key drop_progress; + u8 drop_level; + u8 level; +} __packed; + +struct btrfs_dir_item { + struct btrfs_disk_key location; + uint64_t transid; + __le16 data_len; + __le16 name_len; + u8 type; +} __packed; + +struct btrfs_file_extent_item { + uint64_t generation; + uint64_t ram_bytes; + u8 compression; + u8 encryption; + __le16 other_encoding; /* spare for later use */ + u8 type; + uint64_t disk_bytenr; + uint64_t disk_num_bytes; + uint64_t offset; + uint64_t num_bytes; +} __packed; + +struct btrfs_root_ref { + uint64_t dirid; + uint64_t sequence; + __le16 name_len; +} __packed; + +/* + * btrfs private inode information + */ +struct btrfs_pvt_inode { + uint64_t offset; +}; + + +int btrfs_probe(block_dev_desc_t *rbdd , disk_partition_t *info); + +/* + *search through disk and mount file-system + */ +int btrfs_fs_init(struct btrfs_info *fs); + +/* + *save inode in list + */ +void put_inode(struct inode *inode); + +/* + *memory allocation for new inode + */ +struct inode *alloc_inode(struct btrfs_info *fs, uint32_t ino, size_t data); + +/* + * open btrfs file + */ +int btrfs_open_file(const char *name, struct com32_filedata *filedata); +/* + * reading data from file + */ +int getfssec(struct com32_filedata *filedata, char *buf); +uint32_t generic_getfssec(struct file *file, char *buf, + int sectors, char *have_more); + +/* + * mount btrfs file-system + */ +int btrfs_probe(block_dev_desc_t *rbdd , disk_partition_t *info); + +/* + * listing file/directory on btrfs partition/disk + */ +int btrfs_ls(const char *); + +/* + * read file data + */ +int btrfs_read_file(const char *filename, void *buf, int offset, int len); + +/* + * umount btrfs file-system + */ +void btrfs_close(void); + +#define PVT(i) ((struct btrfs_pvt_inode *)((i)->pvt)) + +#endif |