Re: removable media revalidation - udev vs. devfs or static /dev

Jens Axboe
2004-01-07T10:00:36Z

On Wed, Jan 07 2004, Olaf Hering wrote:
> On Wed, Jan 07, Jens Axboe wrote:
>
> > No need to put it in the kernel, user space fits the bil nicely. I don't
> > see how this would lead to IO errors?
>
> Ok, how should it be done on my SCSI and parallel port ZIP? An ATAPI ZIP
> with 2.4 behaves like that:
>
>
> nectarine:~ # blockdev --rereadpt /dev/hdd
> /dev/hdd: Eingabe-/Ausgabefehler
> nectarine:~ # dmesg | tail
> nfs: server Hilbert2 OK
> nfs: server Hilbert3 not responding, still trying
> nfs: server Hilbert3 OK
> nfs: server Hilbert3 not responding, still trying
> nfs: server Hilbert3 OK
> nfs: server Hilbert2 not responding, still trying
> nfs: server Hilbert2 OK
> ide-floppy: hdd: I/O error, pc = 0, key = 2, asc = 3a, ascq = 0
> ide-floppy: hdd: I/O error, pc = 1b, key = 2, asc = 3a, ascq = 0
> hdd: No disk in drive
> nectarine:~ # cat /proc/ide/hdd/model
> IOMEGA ZIP 100 ATAPI

Two problems here. First, ide-floppy should not verbosely fail these
commands (2/3a/00 is 'medium not present'). Second, you are not using
the proper mechanism to detect media events.

> I have not checked 2.6, but I doubt it is smarter.

I doubt ide-floppy behaves any differently. But at least you can send
packet commands generically to any atapi/scsi device in 2.6, so the code
has a chance to work a bit more generically (without tons of ugly and
different ioctls for each device type).

--
Jens Axboe