[TUHS] Re: SCO's "evidence" (was: RIP Darl McBride former CEO of SCO)

[Larry McVoy <lm@mcvoy.com>]

The bmap implementations I saw were bit for bit identical, same code, same
variables, same style, same indentation.  I'm 100% sure they were not 
independent.  100% sure.

I've traced that code through all the Bell Labs stuff to BSD.  The idea
that BSD redid this code the same way, in my mind, is a bridge too far.
bmap() knows about how stuff is laid out on disk, knows about how stuff
works in the inode (think indirect blocks and double indirect blocks),
there is _no_ _way_ BSD wrote the same code independently.  No f-ing
way.  They just took it.

I know we all want to think all the Bell Labs code is free or has been
reimplemented and it's all good, we're clean.  We're not.

It doesn't matter at this point but it matters to me that we are honest
about how we got here.

On Mon, Nov 04, 2024 at 05:32:19PM -0800, ron minnich wrote:
> I had people relate to me, at least once, cases of utterly independent
> implementations of a function that were byte for byte the same, as found in
> one court case a friend of mine (now deceased) got pulled into. He had to
> prove he'd written his code from scratch. But these were pretty simple
> functions. I don't know if bmap qualifies ...
> 
> How could this happen? I don't know, but the court case that long predated
> SCO. The only conclusion I can reach
> is that when enough techniques, ideas, mailling lists, discussions, and
> documents become part of a shared culture, the code which
> people create might be the same. A weird parallel evolution of code.
> 
> 
> 
> On Mon, Nov 4, 2024 at 5:09???PM Larry McVoy <lm@mcvoy.com> wrote:
> 
> > The thing I never got a reasonable answer to was I found code in BSD that
> > was identical to code going back to at least V7.  Find bmap() in the UFS
> > code and then find the same in V7.  I might be wrong about V7, might be
> > 32V, might be V6.  I don't think it matters, it's the same in all of them.
> >
> > bmap() is the code that maps a logical block to a phsyical block,
> > I'm quite familiar with it because I rewrote it to bmap_write() and
> > bmap_read() as part of making UFS do extents:
> >
> > http://mcvoy.com/lm/papers/SunOS.ufs_clustering.pdf
> >
> > When all the lawsuits were going on, since I knew that code really well,
> > I went off and looked and the BSD code at that time had bit for bit
> > identical bmap() implementations.
> >
> > I never understood why BSD could claim they rewrote everything when they
> > clearly had not rewritten that.
> >
> > I've raised this question before and I just went and looked, bmap() has
> > changed.  I'm pretty sure I have Kirk's BSD source releases, if I do,
> > I'm 100% sure I can back up what I'm saying.  Not sure I care enough to
> > do so, it's all water under the bridge at this point.
> > --
> > ---
> > Larry McVoy           Retired to fishing
> > http://www.mcvoy.com/lm/boat
> >

-- 
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Larry McVoy           Retired to fishing          http://www.mcvoy.com/lm/boat