5 Nov
2024
5 Nov
'24
7:35 a.m.
On Mon, Nov 4, 2024 at 6:09 PM Larry McVoy <lm(a)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.
The short answer is that ffs_bmap.c was one of the 70 files that had
a AT&T copyright notice added to it as part of the AT&T vs Regents suit.
By the time 4.4BSD had been released, the file had been substantially
rewritten, but some traces of original AT&T code remained. CSRG took
the position it was enough that AT&T no longer had enough original code
for them to assert copyright. AT&T too a contrary position. In the end, the
copyright notice was added (where it remains to this day) to acknowledge
this, but permission to use was granted with a covenant to not sue.
So it's complicated: It was rewritten, but not clean-room from scratch
rewritten.
It's one of those complicated situations where there was a real question
over
whether or not there was infringement, in part because there was also a
preliminary ruling that 32V likely didn't have copyright protection for
various
technical reasons, and since Berkeley started from that, there was no case.
AT&T was eager for that preliminary ruling to not be finalized so they
settled
with the Regents and the 7 files were removed completely and copyright
notices added to 70 files but otherwise licensed under what what would
become known as the 4-clause Berkeley License in 4.4BSD-Lite, which
was officially unencumbered by AT&T licensing requirements beyond
the BSDL.
Not a satisfying answer, but most negotiated settlements aren't.
Warner