|Summary:||system hangs when mounting IDE CD writer|
|Product:||[Retired] Red Hat Linux||Reporter:||Mikel Ward <mikel>|
|Component:||kernel||Assignee:||Arjan van de Ven <arjanv>|
|Status:||CLOSED RAWHIDE||QA Contact:||Brian Brock <bbrock>|
|Fixed In Version:||Doc Type:||Bug Fix|
|Doc Text:||Story Points:||---|
|Last Closed:||2001-08-19 13:12:11 UTC||Type:||---|
|oVirt Team:||---||RHEL 7.3 requirements from Atomic Host:|
Description Mikel Ward 2001-08-19 00:32:12 UTC
Description of Problem: I have two IDE CD drives in my system, the first (secondary master - hdc) is a Mitsumi FX-240 CD reader, and the second (secondary slave - hdd/sr0) is a Ricoh MP-7083A CD writer. Mounting, unmounting, and reading using the Mitsumi reader works fine, but trying to mount a disk on the Ricoh writer causes the system to hang. I first noticed this when inserting a CD in KDE 2, where the system attempted to automount the CD, but issuing "mount /mnt/cdrom1" also hangs (as does "mount /dev/sr0 /mnt/cdram"). The CD writer is an IDE drive using SCSI emulation, as configured by Red Hat (kudzu?). Note that in trying to diagnose this problem, I renamed /dev/cdrom1 to /dev/cdram (which makes more sense to me), and removed the "kudzu" parameter to the CD-ROM drives from /etc/fstab. The hang occurred before (and after) making these changes. /etc/fstab contains: ----- LABEL=/ / ext2 defaults 1 1 LABEL=/boot /boot ext2 defaults 1 2 /dev/fd0 /mnt/floppy auto noauto,owner 0 0 LABEL=/var /var ext2 defaults 1 2 LABEL=/home /home ext2 defaults 1 2 none /proc proc defaults 0 0 none /dev/pts devpts gid=5,mode=620 0 0 /dev/hda7 swap swap defaults 0 0 /dev/cdrom /mnt/cdrom auto noauto,owner,ro 0 0 /dev/cdram /mnt/cdram auto noauto,owner,ro 0 0 ----- /etc/sysconfig/hwconf previously contained something like: ----- class: IDE desc: Mitsumi FX-240 device: hdc - class: SCSI desc: Ricoh MP-7083A CD-R/CD-RW device:sr0 bus:0 lun:0 ----- However I deleted hwconf, and kudzu has not recreated entries for either CD drive. /etc/lilo.conf contains the line: "append="hdd=ide-scsi"" lsmod shows: ----- ppp_async 6768 0 (autoclean) ppp_generic 18032 0 (autoclean) [ppp_async] sb 7824 1 (autoclean) sb_lib 35760 0 (autoclean) [sb] uart401 6608 0 (autoclean) [sb_lib] sound 62112 1 (autoclean) [sb_lib uart401] soundcore 4432 5 (autoclean) [sb_lib sound] tdfx 57840 1 autofs 11136 1 (autoclean) ne2k-pci 4864 1 (autoclean) 8390 6752 0 (autoclean) [ne2k-pci] ipchains 38944 0 (unused) ide-scsi 8352 0 scsi_mod 94336 1 [ide-scsi] ide-cd 27104 1 cdrom 27392 0 [ide-cd] usb-uhci 20848 0 (unused) usbcore 49632 1 [usb-uhci] ----- Version-Release number of selected component (if applicable): How Reproducible: Always. Steps to Reproduce: 1. issue "mount /mnt/cdrom1" 2. 3. Actual Results: the system hangs (does not respond to local mouse or keyboard events) Expected Results: the filesystem is mounted Additional Information: this bug may lie in * kudzu * ide-scsi * mount * other running "cdrecord -scanbus" shows: ----- Cdrecord 1.9 (i686-pc-linux-gnu) Copyright (C) 1995-2000 Jvrg Schilling Linux sg driver version: 3.1.17 Using libscg version 'schily-0.1' scsibus0: 0,0,0 0) 'RICOH ' 'CD-R/RW MP7083A ' '1.20' Removable CD-ROM 0,1,0 1) * 0,2,0 2) * 0,3,0 3) * 0,4,0 4) * 0,5,0 5) * 0,6,0 6) * 0,7,0 7) * ----- i would like to try using the CD writer as an IDE drive, but am not sure how to (kudzu seems to always set the drive as a SCSI-IDE drive). i will try to add more information as i find it, but it's annoying since reproducing the bug hangs the system :-)
Comment 1 Mikel Ward 2001-08-19 00:35:49 UTC
I just tried to issue mount with no CD in the drive (trying to avoid crashing the system), and noticed this in the syslog: Aug 19 10:37:16 air kernel: Attached scsi CD-ROM sr0 at scsi0, channel 0, id 0, lun 0 Aug 19 10:37:16 air kernel: sr0: scsi3-mmc drive: 32x/32x writer cd/rw xa/form2 cdda tray Aug 19 10:37:19 air kernel: cdrom: open failed.
Comment 2 Mikel Ward 2001-08-19 00:50:18 UTC
"mount -t iso9660 /dev/hdd /mnt/cdram" gives: ----- mount: wrong fs type, bad option, bad superblock on /dev/hdd, or too many mounted file systems (could this be the IDE device where you in fact use ide-scsi so that sr0 or sda or so is needed?) ----- /dev/cdram (previously /dev/cdrom1) is a symlink to /dev/scd0 SCSI devices: none IDE devices: primary master - Quantum UDMA 33 hard disk secondary master - Mitsumi FX240 CD reader secondary slave - Ricoh MP7083A CD reader/writer
Comment 3 Bernhard Rosenkraenzer 2001-08-19 08:28:27 UTC
mount itself can't lock up the system - this must be happening in the mount system call, assigning to kernel
Comment 4 Arjan van de Ven 2001-08-19 08:32:13 UTC
As a test, could you boot the system with "ide=nodma" and see if it still hangs?
Comment 5 Mikel Ward 2001-08-19 13:12:08 UTC
I added "ide=nodma" to the kernel parameters, and rebooted. After the reboot, I logged in as root and did "mount /mnt/cdrom1", and the filesystem was successfully mounted, so it looks very much like this worked. Thanks! Is this known to only affect certain drives or configurations, so that this condition might be automatically detected and worked-around (by kudzu)?
Comment 6 Arjan van de Ven 2001-08-19 13:19:43 UTC
The 2.4 kernel will automatically enable (U)DMA on devices that claim to support it. Several CDROM drives seem to advertise to support this but don't actually do so. The kernel has a list of "known bad" devices and, surprise surprise, the RICOH MP7083A was added to that list only a few weeks ago due to someone else also seeing this. This means that the next kernel Red Hat will release will just work without this parameter. Also, "ide=nodma" will also disable DMA for your harddisks, this will cost significant performance. You can achieve the same effect by adding a "hdparm -d0 /dev/hdd" in one of the startupscripts which is specific to your cdrw device, without also affecting the harddisks. I'll close this bug as "fixed in rawhide" as the kernel in the rawhide (eg experimental) version has this device already blacklisted. If you object to that, or that kernel somehow doesn't fix it, please reopen this bug.