BLOCK_GROUP_ITEM=192 BlockGroup
CHUNK_ITEM=228 Chunk
DEV_EXTENT=204 DevExtent
DEV_ITEM=216 Dev
DIR_INDEX=96 DirList
DIR_ITEM=84 DirList
EXTENT_DATA=108 FileExtent
EXTENT_DATA_REF=178 ExtentDataRef
EXTENT_ITEM=168 Extent
FREE_SPACE_BITMAP=200 FreeSpaceBitmap
FREE_SPACE_EXTENT=199 Empty
FREE_SPACE_INFO=198 FreeSpaceInfo
INODE_ITEM=1 Inode
INODE_REF=12 InodeRefList
METADATA_ITEM=169 Metadata
ORPHAN_ITEM=48 Empty
PERSISTENT_ITEM=249 DevStats
QGROUP_RELATION=246 Empty
ROOT_ITEM=132 Root
SHARED_BLOCK_REF=182 Empty
SHARED_DATA_REF=184 SharedDataRef
TREE_BLOCK_REF=176 Empty
UNTYPED=0:FREE_SPACE_OBJECTID FreeSpaceHeader
UUID_RECEIVED_SUBVOL=252 UUIDMap
UUID_SUBVOL=251 UUIDMap
XATTR_ITEM=24 DirList