StegFS existed back in the kernel 2.4 days as a variant of ext2. https://en.wikipedia.org/wiki/StegFS https://en.wikipedia.org/wiki/StegFS It is old and defunc

StegFS existed back in the kernel 2.4 days as a variant of ext2. https://en.wikipedia.org/wiki/StegFS https://en.wikipedia.org/wiki/StegFS It is old and defunct, but this is a filesystem version of runlevel containers in an encrypted ext2 volume. Runlevel X can read all data at runlevel 0-X but not deeper. Typing in a "bad password" only lead to data corruption of existing data as there was no password check. This provided plausible deniability in that I could have many runlevels, and "juicy" fake docs to lead people off the trail.