From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161446AbWLPUCc (ORCPT ); Sat, 16 Dec 2006 15:02:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161449AbWLPUCb (ORCPT ); Sat, 16 Dec 2006 15:02:31 -0500 Received: from alnrmhc12.comcast.net ([206.18.177.52]:55536 "EHLO alnrmhc12.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161446AbWLPUCb (ORCPT ); Sat, 16 Dec 2006 15:02:31 -0500 X-Greylist: delayed 435 seconds by postgrey-1.27 at vger.kernel.org; Sat, 16 Dec 2006 15:02:31 EST Date: Sat, 16 Dec 2006 14:55:16 -0500 From: "A. Kalten" To: linux-kernel@vger.kernel.org Subject: DVD-RAM cannot be mounted RW with 2.6.18/2.6.19 Message-Id: <20061216145516.13bdeb68.akalten@comcast.net> X-Mailer: Sylpheed version 2.2.10 (GTK+ 2.10.6; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hello, DVD-RAM disks previously made with a Linux system can no longer be mounted in RW mode. For some reason, as indicated by the error message from the mount command, the disks are detected as being write-protected (which is not the case). To be able to write to these disks, the mount command must be issued again with the "-o remount" option. The commands given are as follows. Although the file type in this example is ext2, the same behavior is seen also with the udf file type. # modprobe ide-cd # hdparm -d1 -X udma4 -k1 /dev/hde # mount -t ext2 -o rw,noatime /dev/hde /cdrom mount: block device /dev/hde is write-protected, mounting read-only # mount -t ext2 -o remount,rw,noatime /dev/hde /cdrom Now the DVD-RAM disk can be written normally, but there should be no need for the second mount command. The kernel log for this command sequence seems to show nothing abnormal: kernel: hde: ATAPI 39X DVD-ROM DVD-R-RAM CD-R/RW drive, 2048kB Cache, UDMA(66) kernel: Uniform CD-ROM driver Revision: 3.20 kernel: hde: CHECK for good STATUS kernel: cdrom: hde: mrw address space DMA selected kernel: cdrom open: mrw_status 'not mrw' Furthermore, if I attempt to check the unmounted DVD-RAM disk with e2fsck, the drive is still reported as read-only: # e2fsck -p /dev/hde e2fsck: Read-only file system while trying to open /dev/hde Disk write-protected; use the -n option to do a read-only check of the device. However, as I indicated above, the disk is not write-protected. I am reporting this problem on the lkml because of a hint that I discovered at this link: http://lists.opensuse.org/packet-writing/2006-10/msg00000.html Although this problem does not involve packet-writing, it may be related to the cdrom code. Andrew Kalten