Messages in this thread | | | Subject | Re: 2.6.3 BUG - can't write DVD-RAM - reported as write-protected | From | Olaf Frączyk <> | Date | Tue, 23 Mar 2004 16:32:42 +0100 |
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On Tue, 2004-03-23 at 15:50, Olaf Frączyk wrote: > On Sun, 2004-03-14 at 12:22, Jens Axboe wrote: > > On Sun, Mar 14 2004, Olaf Fr?czyk wrote: > > > On Tue, 2004-03-09 at 10:12, Jens Axboe wrote: > > > > On Tue, Mar 09 2004, Olaf Fr?czyk wrote: > > > > > 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 > > > > > > > > Can you try to instrument drivers/cdrom/cdrom.c:cdrom_get_disc_info() > > > > and find out where it fails? Change the cgc.quiet = 1 to a = 0 in there > > > > as well (that alone might be enough to pin point the problem). > > > Sorry for the delay. I couldn't take tha machine down. > > > After setting cgc.quiet=0 I get no additional messages from kernel. > > > cdrom_get_disc_info returns after FIRST: > > > cdo->generic_packet(cdi, &cgc). > > > > Ok, at least that's a little clue... Maybe your drive is buggy (I think > > we already established that, question is what the bug is) and doesn't > > like to return just two bytes, please try with attached patch. > > > > > BTW, I suppose return codes are interpreted not well: > > > In cdrom_get_disc_info we return after first (cdo->generic_packet) if it > > > returns not 0. (Success?) And we return with not 0 value. > > > And in cdrom_media_erasable we assume that not 0 is error, not success. > > > So probably in cdrom_get_disc_info we should have: > > > if (!(ret = cdo->generic_packet(cdi, &cgc))) > > > return ret; > > > > No, you are not reading the code correctly. ->generic_packet() returns 0 > > on success, or the error (standard kernel practice). > > cdrom_media_erasable() returns a bool, and if cdrom_get_disc_info() > > fails then we return it's not erasable. > > > > > I tried it, but it changed nothing regarding to the problem. > > > It returns then after second cdo->generic_packet, but I still get: > > > read di failed. > > > > You broke it, the first check simply returns the header so .erasable > > must be 0 because we cleared the buffer first. > > > > ===== drivers/cdrom/cdrom.c 1.49 vs edited ===== > > --- 1.49/drivers/cdrom/cdrom.c Thu Mar 11 13:31:15 2004 > > +++ edited/drivers/cdrom/cdrom.c Sun Mar 14 12:21:44 2004 > > @@ -2658,11 +2658,13 @@ > > /* set up command and get the disc info */ > > init_cdrom_command(&cgc, di, sizeof(*di), CGC_DATA_READ); > > cgc.cmd[0] = GPCMD_READ_DISC_INFO; > > - cgc.cmd[8] = cgc.buflen = 2; > > - cgc.quiet = 1; > > + cgc.cmd[8] = cgc.buflen = 8; > > + cgc.quiet = 0; > > > > - if ((ret = cdo->generic_packet(cdi, &cgc))) > > + if ((ret = cdo->generic_packet(cdi, &cgc))) { > > + printk("cdrom: read_di failed, %d\n", ret); > > return ret; > > + } > > > > /* not all drives have the same disc_info length, so requeue > > * packet with the length the drive tells us it can supply > > @@ -2673,6 +2675,7 @@ > > if (cgc.buflen > sizeof(disc_information)) > > cgc.buflen = sizeof(disc_information); > > > > + printk("cdrom: re-reading di, len=%d\n", cgc.buflen); > > cgc.cmd[8] = cgc.buflen; > > return cdo->generic_packet(cdi, &cgc); > > } > On 2.6.4 with your patch I get: > Mar 23 15:46:03 venus kernel: cdrom: read_di failed, -95 I have found, that I can't mount CD in my Yamaha 6416S now. It worked with 2.6.3. So we have two problems now. Should I start separate thread or continue here?
When I try to mount CD I get in command line: [root@venus scsi]# mount /dev/scd0 /mnt/cdrom /dev/scd0: Invalid argument mount: block device /dev/scd0 is write-protected, mounting read-only /dev/scd0: Invalid argument mount: /dev/scd0: can't read superblock
And in /var/log/messages: Mar 23 16:23:08 venus kernel: end_request: I/O error, dev sr0, sector 0 Mar 23 16:23:08 venus kernel: FAT: unable to read boot sector
Regards,
Olaf
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