Subject: Re: Disklabel oddity
To: Wolfgang Solfrank <firstname.lastname@example.org>
From: Ken Hornstein <email@example.com>
Date: 04/19/1996 14:14:45
>> Hmmm, the more I think about it, the more I realize that using disklabel
>> perhaps isn't the right thing to do. The block numbers in the ISO filesystem
>> are probably absolute, and shouldn't be offset-corrected by the disklabel
>That's correct. (At least it should. I can imagine people writing something
>different on their CDs. In fact, thinking about it again, I'd not be surprised
>if those "multi-volume" CDs do have relative addresses instead of absolute
So, I don't suppose there is a way to differentiate betweeen a multisession
and a faux-multivolume CD-ROM, is there?
>> It almost sounds like it makes more sense to add functionality to
>> mount_cd9660 so you could specifiy a session number. You could then have
>> it read the disklabel, figure out the start of the ISO filesystem, and pass
>> that to the mount system call. What do people think of that idea?
>What disklabel are you referring to?
Sorry, I was EDRUNK last night, and I'm not quite all there today :-) I'm
talking about the TOC on the disk.
>It should request the start of the requested session from the driver, read
>the volume labels (block 16 and following) from there, and use the block
>numbers given as absolute addresses on the CD. By default, it should use
>the last session (requested by another ioctl).
Okay, here's where I get a bit confused. The TOC on the disk shows a bunch
of data tracks. Are the data tracks different from the sessions, or are
they one-in-the-same? Are sessions a layer above data tracks? Will a
3-session CD-ROM show 3 data tracks?
If you have any place where this is all explained, please point me to it!
I've been digging around lately, but I haven't found much info about