I'm curious why you think file systems written in C would somehow be better than any other type of program written in C. We have plenty of data suggesting C programs have more bugs and vulnerabilities than programs written in safer languages.
And for specific examples of options with better safety records, then sure Rust would be one possibility, as would Ada, or Frama-C if you need to stick with C.
> I'm simply disputing your general claim that moving away from C would not help
I never said such a thing, I said we don't know. As always, in theory, there is no difference between theory and practice; in practice, there is.