bitmap_copy_clear_tail
bitmap_copy_clear_tail((unsigned long *) (bitmap), \
bitmap_copy_clear_tail((unsigned long *) (buf), \
bitmap_copy_clear_tail((unsigned long *)(bitmap), (const unsigned long *)(buf), (nbits))
bitmap_copy_clear_tail((unsigned long *)(buf), (const unsigned long *)(bitmap), (nbits))
bitmap_copy_clear_tail(NULL, NULL, 0);