From 2388edd10d9aab9c0f3817e73addd3dc0bc870bf Mon Sep 17 00:00:00 2001

From: Lukas Nykryn <lnykryn@redhat.com>

Date: Thu, 27 Feb 2014 11:06:37 +0100

Subject: [PATCH] cdrom_id: use the old MMC fallback

https://bugzilla.redhat.com/show_bug.cgi?id=1038015

The problem seems to be that the your virtual DVD is emulating a really

old DVD device, and doing it kind of strangely.

> dracut:# /lib/udev/cdrom_id --debug /dev/sr0

> probing: '/dev/sr0'

> INQUIRY: [IMM     ][Virtual CD/DVD   ][0316]

> GET CONFIGURATION failed with SK=5h/ASC=24h/ACQ=00h

So your virtual drive rejects the GET CONFIGURATION command as illegal.

Other pre-MMC2 drives that don't accept this command usually return the

error

SK=5h,ASC=20h (invalid/unsupported command code), in which case cdrom_id

tries an older method, and then ID_CDROM_MEDIA_TRACK_COUNT_DATA gets set

and all the /dev/disk/by-label (etc) links get set up.

The virtual drive returns the error SK=5h,ASC=24h (invalid field in

Command Descriptor Block), which cdrom_id doesn't handle, so it gives up

and the links never get made.

The ideal solution would be to make the IMM to emulate a device that's

less than 15 years old, but I'm not going to hold my breath waiting for

that.

So probably cdrom_id should also use the old MMC fallback when the error

is SK=5h,ASC=24h, and then all of this would work as expected.

Suggested-by:Luca Miccini <lmiccini@redhat.com>

(cherry picked from commit a14f14976094650e17d39f3a7d15a1c68c93c333)

---

 src/udev/cdrom_id/cdrom_id.c | 2 +-

 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/udev/cdrom_id/cdrom_id.c b/src/udev/cdrom_id/cdrom_id.c

index 93467c2..33b2bc3 100644

--- a/src/udev/cdrom_id/cdrom_id.c

+++ b/src/udev/cdrom_id/cdrom_id.c

@@ -556,7 +556,7 @@ static int cd_profiles(struct udev *udev, int fd)

         if ((err != 0)) {

                 info_scsi_cmd_err(udev, "GET CONFIGURATION", err);

                 /* handle pre-MMC2 drives which do not support GET CONFIGURATION */

-                if (SK(err) == 0x5 && ASC(err) == 0x20) {

+                if (SK(err) == 0x5 && (ASC(err) == 0x20 || ASC(err) == 0x24)) {

                         log_debug("drive is pre-MMC2 and does not support 46h get configuration command");

                         log_debug("trying to work around the problem");

                         ret = cd_profiles_old_mmc(udev, fd);