Date: Tue, 24 Feb 1998 03:33:05 +0000 (GMT) From: Terry Lambert <tlambert@primenet.com> To: mike@smith.net.au (Mike Smith) Cc: tlambert@primenet.com, mike@smith.net.au, hasty@rah.star-gate.com, scrappy@hub.org, freebsd-current@FreeBSD.ORG Subject: Re: ATAPI related patch .. Message-ID: <199802240333.UAA17080@usr05.primenet.com> In-Reply-To: <199802240243.SAA13579@dingo.cdrom.com> from "Mike Smith" at Feb 23, 98 06:43:06 pm
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> > Pull the other one. Audio track disk blocks are not evenly divisible
> > into (or by) a page size.
>
> I'm not pulling nothing. Put an audio CD into your Win98 machine (or
> Win95 OSR2 machine for that matter), and 'cd' to the drive in a penalty
> box.
>
> Tell me what you see *there*.
A display on a graphical exporer front-ending for an OS without a
unified VM and buffer cache.
> Sure, this is just a case where you need a SLICE layer that understands
> non-multiple non-factor block size transforms.
No. Julian's soloution was that you would need to aggregate partial
real blocks underneath the page abstraction.
Like many things, it requires a working VOP_{GET|PUT}PAGES.
> Bear in mind that all you're actually doing is providing directory
> entries that someone can open. Nobody says that the files can be
> *mapped*, although they ought to be mappable. 8)
If you are going to read them, then you are going to (effectively)
map them, because the VM objects backed by the file are hung off the
vnode. All a mapping is, is pointing a memory region at a set of
pages backed by a vnode. It doesn't matter how the pages got hung
off the vnode, so long as the contain completely valid or completely
invalid data. 8-).
Terry Lambert
terry@lambert.org
---
Any opinions in this posting are my own and not those of my present
or previous employers.
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