5 Nov
2024
5 Nov
'24
7:54 a.m.
On Mon, Nov 04, 2024 at 06:35:30PM -0700, Warner Losh wrote:
On Mon, Nov 4, 2024 at 6:09???PM Larry McVoy
<lm(a)mcvoy.com> wrote:
Yeah, this is completely a false claim. It was identical. At least
in 4.3 BSD, I can imagine that 4.4 changed it because I was pointing
this out around then.
For the record, I'm a BSD guy, my OS was SunOS 4.x, it was a bug fixed
BSD. If there ever was a guy that wanted this to be true, it's me.
It's not true, BSD ripped off Bell Labs code, that's a fact.
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.