Who is Mr. and Mrs. Chinaski from Factotum and what is their importance?

Henry's parents, the unnamed Chinaskis, still live in Los Angeles. He is brown-haired and taller than Henry, a proud veteran of World War I, and intolerant of Henry's 4-F draft status. Mother is easily upset. Both are still working, with Mother having just taken a new job. Father insists that Henry find a job immediately and pay room, board, and laundry. When Henry shows up drunk on the doorstep, parents and son assault one another viciously. When he bails Henry out of jail, he adds legal costs. Henry moves out as soon as he is paid up. Jan later declares that his hatred for his parents warps Henry.