xdr_buf_to_sg
int xdr_buf_to_sg(const struct xdr_buf *buf, unsigned int offset,
body_nsg = xdr_buf_to_sg(body, 0, body->len,
EXPORT_SYMBOL_GPL(xdr_buf_to_sg);
ret = xdr_buf_to_sg(buf, offset, len, sg_head, nsg);