PAGE_ALIGN
#define PAGE_ALIGN(x) (((x) + (B_PAGE_SIZE - 1)) & ~(B_PAGE_SIZE - 1))
#define PAGE_ALIGN(size) (((size) + B_PAGE_SIZE - 1) & ~(B_PAGE_SIZE - 1))
#define PAGE_ALIGN(x) (((x) + (FSSH_B_PAGE_SIZE - 1)) & ~(FSSH_B_PAGE_SIZE - 1))