Re: Raw-device-war (was Re: Sharing SCSI disks)

Hugo Van den Berg (
Tue, 1 Apr 1997 16:18:07 +0100 ()

On Wed, 26 Mar 1997, Mikko Ala-Fossi wrote:

> On Tue, 25 Mar 1997, David S. Miller wrote:
> > Date: Tue, 25 Mar 1997 14:25:38 -0800 (PST)
> > From: Michael Neuffer <neuffer@nomis.i-Connect.Net>
> > On Tue, 25 Mar 1997, Illuminati Primus wrote:
> > > However, unlike an MS OS, you are always free to join in the development
> > > effort. If RAW IO in linux is important to you, you could always help
> > > implement it instead of continue to whine about its absence.
> > We did, it got stopped cold it its tracks by Linus.
> > Since when does pinhead Torvalds completely control what features
> > Linux provides for "everyone" on the planet? He never has and he
> > never will.
> Since this raw-device-war is going personal and is going to last
> till someone is dead, I have a proposal.
> Raw-device support could be done as a kernel module and only
> necessary hooks should be made to the kernel itself. Since
> there is a danger that people who don't _really_ need those
> raw devices will try to use them to speed up their applications,
> it should be made difficult to use raw-device and it should
> not be default or automatic behaviour of the kernel.
> We don't want MS-DOS syndrome where every application has
> access to raw-devices and do their own hardware drivers.
> Whole idea of Linux is that hardware and raw devices are
> centralized under kernel control to provide certain common
> services to these devices that are buffered and optimized
> to the last byte. (however GGI follows idea presented but
> it is not added to the kernel, that's why we have too diverce
> support for graphics)
> There are few ways to do support for raw devices without adding
> it to the official kernel itself:
> 1. Maintain your own patches to linux kernel to do support for raw devices.
> 2. Try to convince kernel maintainers to add hooks and do your own module
> (distributed as a separate source file).
> Hooks for the raw-device support should however be under kernel option
> and should default to not to support raw-devices. I think it is not
> wise to add straight raw-device support to kernel, because it is a
> message to application programmers to start using their own buffer-
> routines to optimize their application performance.

It may just be my limited understanding of the subject, but as far as I
can see it's already possible to have raw access to a disk, how else could
mke2fs do it's work ? The discussion seems to be about
buffered/unbuffered, and why shouldn't you supply unbuffered devices if
someone wants them ?

Hugo Van den Berg -
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