You are wrong: Luzhin in Dostoevsky comes from luzha,
"puddle."
Btw., Volgin is also the hero in Chernyshevsky's
Prologue (see Nabokov's The Gift).
Also, I forgot to mention that d'Onsky, the name of
a character in ADA, Demon Veen's rival, comes from Don, the
river flowing from the Tula province in central Russia to the sea
of Azov. Cf. Onegin's donskoy zherebets, a Don stallion, in
Pushkin's Eugene Onegin (Chapter Two, V, 4).