simplify disksort, please review.

[Poul-Henning Kamp]

In message <20050609193008.GB837 at darkness.comp.waw.pl>, Pawel Jakub Dawidek writes:

>The one example of how the order can be broken (write(offset, size)):
>
>	write(1024, 512)
>	write(0, 2048)

If you issue these two requests just like that, you get no guarantee
which order they get written in.

It's not just disksort which might surprise you, tagged queuing and
write caches may mess up your day as well.

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Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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