vm_page_set_valid_range
vm_page_set_valid_range(m, 0, size - toff);
vm_page_set_valid_range(m, 0, size - toff);
vm_page_set_valid_range(m, off & PAGE_MASK, eoff - off);
vm_page_set_valid_range(m, base & PAGE_MASK, n);
vm_page_set_valid_range(bp->b_pages[i], j * DEV_BSIZE,
void vm_page_set_valid_range(vm_page_t m, int base, int size);
vm_page_set_valid_range(mt, 0,
vm_page_set_valid_range(m, base, size);