Subject: Re: File > 2G on a dvd
To: Wolfgang Solfrank <>
From: Rhialto <>
List: current-users
Date: 11/29/2004 18:37:09
On Mon 29 Nov 2004 at 14:56:54 +0100, Wolfgang Solfrank wrote:
> Well, I once was thinking about support for this in NetBSD's cd9660,

as was I, when I read about this "level 3" thing,

> but discovered that the there is no easy support for this, as the
> "file sections" can be of arbitrary lengths, e.g. the first 3 sections
> could be 3 bytes each.
> Which means that you cannot easily convert a file offset to a block
> number and vice versa.  However, the fs independent code in NetBSD
> assumes in various places that it _can_ do this conversion without the
> help of fs dependent code.

Not knowing the ins and outs of the filesystem code, I can't think why
any fs independent code would need a byte offset <-> relative block
number conversion. Any place where that is seriously used would be
inside the specific filesystem code itself? Perhaps it won't much matter
if the naively calculated relative block numbers are only imaginary.
And perhaps the issues are even smaller because cd9660 is a read-only
filesystem (although it would be nice if it could be implemented r/w,
but I'm not sure the specification allows that easily).

> Wolfgang
                           -- Ceterum censeo "authored[1]" delendum esse.
___ Olaf 'Rhialto' Seibert -- [1] Ugly English neologism[2].
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