CHUNK_ITEM=228 Chunk
DEV_ITEM=216 Dev
DEV_EXTENT=204 DevExtent
UNTYPED=0, Empty
QGROUP_RELATION=246 Empty
INODE_ITEM=1 Inode
INODE_REF=12 InodeRef
ORPHAN_ITEM=48 Orphan
PERSISTENT_ITEM=249 DevStats
ROOT_ITEM=132 Root
UUID_SUBVOL=251 UUIDMap
UUID_RECEIVED_SUBVOL=252 UUIDMap