extent_ad
struct extent_ad volAbstract;
struct extent_ad volCopyright;
struct extent_ad mainVolDescSeqExt;
struct extent_ad reserveVolDescSeqExt;
struct extent_ad nextVolDescSeqExt;
struct extent_ad integritySeqExt;
struct extent_ad allocDescs[];
struct extent_ad nextIntegrityExt;
static inline struct kernel_extent_ad leea_to_cpu(struct extent_ad in)