Re: [patch] IDE driver model update

Pavel Machek
2002-10-09T09:26:24Z

Hi!

> > > > _ALL_ buses that have driverfs support (IDE, SCSI, USB, PCI) have their
> > > > own rules for lifetimes of their structures. And that's not likely to
> > > > change - these objects belong to drivers and in some cases (IDE) are
> > > > not even allocated dynamically - they are reused if nothing is holding
> > > > them.
> > >
> > > IDE objects can also outlast the hardware - consider an active mount on
> > > an ejected pcmcia card. Right now we don't do the right stuff to
> > > reconnect that on re-insert but one day we may need to. As it is we keep
> > > the instance around to avoid crashes
> >
> > Ouch. That (reconnects) may require interesting things from queue-related
> > code. What behaviour do you want while card is disconnected? All requests
> > getting errors / all requests getting blocked / reads failing, writes blocking?
>
> This raises the interesting possibility of being able to refer to
> things like removable media directly, instead of the device the media
> is inserted in.
>
> The Amiga was doing this years ago. You could access floppy drives
> as, E.G. df0:, df1:, etc, but if you formatted a volume and called it
> foobar, you could access foobar: no matter which floppy drive you put
> it in to.
>
> Also, Plan 9 does similar interesting things - you can do the equivilent of:
>
> ls /internet/websites/kernel.org/
>
> and treat the website as a filesystem.

uservfs.sf.net, and you can do similar stuff on linux.
Pavel
--
I'm pavel@ucw.cz. "In my country we have almost anarchy and I don't care."
Panos Katsaloulis describing me w.r.t. patents at discuss@linmodems.org