[TUHS] inodes, inumbers, and versions

[Clem Cole via TUHS]

below

On Fri, Feb 6, 2026 at 1:14 PM Ronald Natalie via TUHS <tuhs at tuhs.org>
wrote:

> ...
> It wasn’t until later (Berkeley, I think) that someone overhauled the
> filesystem code to assure that things were ordered in a way that never
> left the filesystem in a degenerate state on crashing.
>
It was George Goble at Purdue who did the work to "harden" the file system
in the original 4.1BSD code in approx 1980 [which was pushed back to UCB
and was first included in BSD4.1A].  Besides the Dual Vax, George spliced a
PDP-11 into the memory bus of one of his Vaxes and wrote a really neat
memory analyzer/kernel debugger [which, sadly, was before USENIX had formal
papers and may be lost to time].

Using it, he found several races and at least one zero-day issue in 4.1,
all of which led up to his dual-CPU "Purdue Vax," a paper all its own.  I
remember the USENIX meeting (after he found ther zero-day), he had an
invite-only/closed-door meeting with about 10-15 of the major UNIX systems
people, and he explained it and the fix [Unix had a reputation of being
secure, and this was the time of the UNIX *vs.* VMS fights in many places
and George was worried that if the zero-day got out, it would hurt the
reputation of not being "production quality."]   IIRC, the changes for both
file system hardening and this fix were in a Purdue directory on one of the
USENIX tapes [although I may have had them at Tektronix directly from
George].