Re: 2.6.3 BUG - can't write DVD-RAM - reported as write-protected
From: Olaf Frączyk
Date: Tue Mar 09 2004 - 02:57:15 EST
On Sun, 2004-03-07 at 11:59, Jens Axboe wrote:
> On Fri, Mar 05 2004, Olaf Fr?czyk wrote:
> > On Fri, 2004-03-05 at 09:23, Jens Axboe wrote:
> > > On Thu, Mar 04 2004, Olaf Fr?czyk wrote:
> > > > Hi,
> > > > I switched to 2.6.3 from 2.4.x serie.
> > > > When I mount DVD-RAM it is mounted read-only:
> > > >
> > > > [root@venus olaf]# mount /dev/dvdram /mnt/dvdram
> > > > mount: block device /dev/dvdram is write-protected, mounting read-only
> > > > [root@venus olaf]#
> > > >
> > > > In 2.4 it is mounted correctly as read-write.
> > > >
> > > > Drive: Panasonic LF-201, reported in Linux as:
> > > > MATSHITA DVD-RAM LF-D200 A120
> > > >
> > > > SCSI controller: Adaptec 2940U2W
> > >
> > > What does cat /proc/sys/dev/cdrom/info say? Do you get any kernel
> > > messages in dmesg when the rw mount fails?
> >
> > I get nothing in /var/log/dmesg and in /var/log/messages
> > In /proc/sys/dev/cdrom/info I get:
> > [olaf@venus olaf]$ cat /proc/sys/dev/cdrom/info
> > CD-ROM information, Id: cdrom.c 3.20 2003/12/17
> >
> > drive name: sr1 sr0 hdc
> > drive speed: 0 16 44
> > drive # of slots: 1 1 1
> > Can close tray: 1 1 1
> > Can open tray: 1 1 1
> > Can lock tray: 1 1 1
> > Can change speed: 1 1 1
> > Can select disk: 0 0 0
> > Can read multisession: 1 1 1
> > Can read MCN: 1 1 1
> > Reports media changed: 1 1 1
> > Can play audio: 1 1 1
> > Can write CD-R: 0 1 1
> > Can write CD-RW: 0 1 1
> > Can read DVD: 1 0 0
> > Can write DVD-R: 0 0 0
> > Can write DVD-RAM: 1 0 0
> > Can read MRW: 0 0 1
> > Can write MRW: 0 0 1
> >
> > The one I'm mounting is /dev/scd1.
> > As there is capablity to write-protect DVD-RAM disk (like a 1.44"
> > Floppy), I think that the linux kernel interprets some message from
> > device in wrong way.
>
> Please repeat with this patch applied and send back the results, thanks.
>
> ===== drivers/cdrom/cdrom.c 1.48 vs edited =====
> --- 1.48/drivers/cdrom/cdrom.c Mon Feb 9 21:58:21 2004
> +++ edited/drivers/cdrom/cdrom.c Sun Mar 7 11:58:40 2004
> @@ -645,9 +645,12 @@
> {
> disc_information di;
>
> - if (cdrom_get_disc_info(cdi, &di))
> + if (cdrom_get_disc_info(cdi, &di)) {
> + printk("cdrom: read di failed\n");
> return 0;
> + }
>
> + printk("cdrom: erasable: %d\n", di.erasable);
> return di.erasable;
> }
>
I get:
cdrom: read di failed
Regards,
Olaf
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