Re: patent on O_ATOMICLOOKUP [Re: [PATCH] loopable tmpfs (2.4.17)]

Larry McVoy
2002-05-26T16:27:29Z

On Sun, May 26, 2002 at 03:30:46AM -0400, Alexander Viro wrote:
> On Sat, 25 May 2002, Larry McVoy wrote:
> You are tripping. bmap() is obviously different in 32V and 4.2BSD -
> filesystems are different and yes, it _is_ a profound part of filesystem.

You're right, I was tripping, I don't know what I was smokng, I know that
code path and they can't be the same. That said...

> The only thing that
> does match is use of function and fact that old and new filesystems
> have similar data structure for indirect, etc. blocks. Notice that
> it's similar, not identical - e.g. use of fragments in FFS changes
> quite a few things.

Oh, come on, read the code side by side, I'm doing it now (kind of fun, too,
it's been a long time since I've been in here). If you have BK installed,
or have tkdiff, run that on the two functions side by side. You're absolutely
right, they aren't identical (what was I thinking? Shame on me, I've worked
on this code, it's impossible for them to be the same by definition), but
one is clearly an extension of the other. This is *not* a rewrite. Or if
it is, I didn't get the memo where they changed the definition of rewrite.
--
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Larry McVoy lm at bitmover.com http://www.bitmover.com/lm