From a14f14976094650e17d39f3a7d15a1c68c93c333 Mon Sep 17 00:00:00 2001 From: Lukas Nykryn 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 --- src/udev/cdrom_id/cdrom_id.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git src/udev/cdrom_id/cdrom_id.c src/udev/cdrom_id/cdrom_id.c index 93467c2..33b2bc3 100644 --- src/udev/cdrom_id/cdrom_id.c +++ 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); -- 1.7.9.2