xbitmap32_clear
return xbitmap32_clear(&bitmap->agbitmap, start, len);
return xbitmap32_clear(&bitmap->aginobitmap, agino, len);
error = xbitmap32_clear(bitmap, start, len);
error = xbitmap32_clear(bitmap, bn->bn_start,
int xbitmap32_clear(struct xbitmap32 *bitmap, uint32_t start, uint32_t len);