__align_up
#define NL_ITEM_ALIGN(_len) __align_up(_len, NL_ITEM_ALIGN_SIZE)
#define _ALIGN(p) __align_up((p), _ALIGNBYTES + 1)
#define roundup2(x, y) __align_up(x, y) /* if y is powers of two */
((namelen) == 0 ? 0 : __align_up((namelen) + 1, _IN_ALIGN))