/* copy from fs while checksumming, otherwise like csum_partial  */
__wsum csum_partial_copy_from_user(const void __user *src, void *dst, int len, __wsum sum, int *csum_err)
/* copy from fs while checksumming, otherwise like csum_partial  */
__wsum csum_partial_copy_from_user(const void __user *src, void *dst, int len, __wsum sum, int *csum_err)
{
	int missing;
	missing = __copy_from_user(dst, src, len);
	if (missing) {
		memset(dst + len - missing, 0, missing);
		*csum_err = -EFAULT;
	} else
		*csum_err = 0;
	return csum_partial(dst, len, sum);
}