why are there kexts in file system user space extensions?
in OSX multiple driver types can exist entirely in user space, with no kext. [ former Apple engineer here ]
Are you saying you can write a 100% user-space "driver" that allows for `mount`ing into the regular file system? How does that work? Can a non-root user supply the code running to serve /some/path that is visible for any process on the system, even root?