Common removable media interface?

Common removable media interface?

[Joe Krahn]

I think Linux could use a common removable
media interface, sort of like cdrom.c adds
a common interface to all CD/DVD. But, cdrom.c
does such a good job, it almost seems like the
thing to do is to just add acces to other
devices to cdrom.c, and maybe rename it to
media.c. Other media includes IDE floppies,
regular floppies (if they live much longer),
solid state media. Maybe even include some
access to all media (not to replace the real
drivers) like tapes, non-removable disks, etc.

Is anyone working on or thinking about
such a thing?
Do other people think this would be useful?
Would it be 'bad' to just add IDE floppy
access (not well developed) to cdrom.c,
(which is already mislabelled now that it
handles DVD)?

Joe Krahn

Re: Common removable media interface?

[Jens Axboe]

On Tue, Dec 18 2001, Joe Krahn wrote:
> I think Linux could use a common removable
> media interface, sort of like cdrom.c adds
> a common interface to all CD/DVD. But, cdrom.c
> does such a good job, it almost seems like the
> thing to do is to just add acces to other
> devices to cdrom.c, and maybe rename it to
> media.c. Other media includes IDE floppies,
> regular floppies (if they live much longer),
> solid state media. Maybe even include some
> access to all media (not to replace the real
> drivers) like tapes, non-removable disks, etc.
> 
> Is anyone working on or thinking about
> such a thing?
> Do other people think this would be useful?
> Would it be 'bad' to just add IDE floppy
> access (not well developed) to cdrom.c,
> (which is already mislabelled now that it
> handles DVD)?

Stuff like this belongs in user space, no need to bloat the kernel with
it.

-- 
Jens Axboe

Re: Common removable media interface?

[Joe Krahn]

Jens Axboe wrote:
> 
> On Tue, Dec 18 2001, Joe Krahn wrote:
> > I think Linux could use a common removable
> > media interface, sort of like cdrom.c adds
...
> 
> Stuff like this belongs in user space, no need to bloat the kernel with
> it.
> 
> --
> Jens Axboe
OK, you are right. Bloat is bad. So,
would you say that new drivers should keep ioctls
to a bare minimum, much less than cdrom.c, and just
provide generic access, like SG_IO/HDIO_DRIVE_CMD,
as a general rule from now on?
(Sounds OK to me...)

Joe Krahn

Re: Common removable media interface?

[Alan Cox]

> OK, you are right. Bloat is bad. So,
> would you say that new drivers should keep ioctls
> to a bare minimum, much less than cdrom.c, and just
> provide generic access, like SG_IO/HDIO_DRIVE_CMD,
> as a general rule from now on?
> (Sounds OK to me...)

Even better would be to move the from the existing drivers into a kernel
compat module you can load for older apps/tools. Our module tools and kernel
code already allow that module to be loaded on demand

Alan

Re: Common removable media interface?

[Jens Axboe]

On Tue, Dec 18 2001, Joe Krahn wrote:
> Jens Axboe wrote:
> > 
> > On Tue, Dec 18 2001, Joe Krahn wrote:
> > > I think Linux could use a common removable
> > > media interface, sort of like cdrom.c adds
> ...
> > 
> > Stuff like this belongs in user space, no need to bloat the kernel with
> > it.
> > 
> > --
> > Jens Axboe
> OK, you are right. Bloat is bad. So,
> would you say that new drivers should keep ioctls
> to a bare minimum, much less than cdrom.c, and just
> provide generic access, like SG_IO/HDIO_DRIVE_CMD,
> as a general rule from now on?
> (Sounds OK to me...)

That's exactly what I'm saying, in fact that's the direction that 2.5 is
heading currently (rq->cmd[]). _One_ packet ioctl for your atapi or scsi
removables, done.

-- 
Jens Axboe