mdu_array_info_t   40 include/uapi/linux/raid/md_u.h #define GET_ARRAY_INFO		_IOR (MD_MAJOR, 0x11, mdu_array_info_t)
mdu_array_info_t   49 include/uapi/linux/raid/md_u.h #define SET_ARRAY_INFO		_IOW (MD_MAJOR, 0x23, mdu_array_info_t)