Musannaf Ibn Abi Shayba 1:2063

Waki’ narrated to us, from Isma’il, from al-Sha’bi, who said: If one forgets rinsing the mouth and sniffing water into the nose during major ritual impurity (janabah), he must repeat [the ghusl]. And if he forgets them during ablution (wudu’), it is sufficient for him.