From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161479AbWAMHXX (ORCPT ); Fri, 13 Jan 2006 02:23:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161486AbWAMHXX (ORCPT ); Fri, 13 Jan 2006 02:23:23 -0500 Received: from embla.aitel.hist.no ([158.38.50.22]:15252 "HELO embla.aitel.hist.no") by vger.kernel.org with SMTP id S1161479AbWAMHXW (ORCPT ); Fri, 13 Jan 2006 02:23:22 -0500 Message-ID: <43C7567C.1090801@aitel.hist.no> Date: Fri, 13 Jan 2006 08:27:56 +0100 From: Helge Hafting User-Agent: Debian Thunderbird 1.0.7 (X11/20051017) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Chuck Ebbert <76306.1226@compuserve.com> CC: Helge Hafting , Greg KH , linux-kernel , Bartlomiej Zolnierkiewicz Subject: Re: 2.6.15 OOPS while trying to mount cdrom References: <200601121818_MC3-1-B5C5-46C7@compuserve.com> In-Reply-To: <200601121818_MC3-1-B5C5-46C7@compuserve.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Chuck Ebbert wrote: >In-Reply-To: <20060110184624.GA6721@aitel.hist.no> > >On Tue, 10 Jan 2006 Helge Hafting wrote: > > > >>Kernel 2.6.15 amd64, gcc 4.1.0 from debian. >> >>The cdrom (/dev/hda) is usually fine. I tried booting with >>hda=ide-scsi in order to read a scratched audio cd with cdparanoia. >>That way, I at least get error messages when the scratches are >>too bad. >> >>I forgot about hda=ide-scsi, and tried to mount /dev/hda as >>usual in order to read an ordinary iso9660 cd. This is >>probably not supposed to work when ide-scsi is using the device, >>but then I expect something like EBUSY rather than this oops: >> >>ide-scsi: unsup command: dev hda: flags = REQ_SORTED REQ_CMD REQ_STARTED >>REQ_ELVPRIV >>sector 64, nr/cnr 2/2 >>bio ffff8100044a9b40, biotail ffff8100044a9b40, buffer ffff81000cb4d000, data >>0000000000000000, len 0 >>end_request: I/O error, dev hda, sector 64 >>isofs_fill_super: bread failed, dev=hda, iso_blknum=16, block=32 >>Unable to handle kernel NULL pointer dereference at 0000000000000000 RIP: >>{strlen+2} >> >> > > >The IDE driver probably shouldn't have allowed the bdev to be opened in >the first place. > >After that happened, mount attempted to fill the superblock and the I/O >failed. Upon failure, get_sb_bdev() called deactivate_super() >(fs/super.c line 718) and all hell broke loose. > > - deactivate_super() called fs->kill_sb() (super.c line 176) which > pointed to kill_block_super() (fs/isofs/inode.c line 1411) > > - kill_block_super() called kobject_uevent() with action KOBJ_UMOUNT > (Question: why is it sending UMOUNT for a mount that never happened?) > > - kobject_uevent() called kobject_get_path() and one of the objects > had a null kobject.name, which caused strlen() to oops. > >There seem to be several bugs here: > >(1) IDE shouldn't have allowed the bdev to be opened. > >(2) (maybe) kobject_uevent shouldn't have been called for an unmount event > when the mount never succeeded. > >(3) kobject_get_path() shouldn't oops when a path component has a NULL name, > or else kobject should fail registration of any such object. > > > > >>The pc didn't seem to malfunction after this. >> >> > >If you attempt to mount the CD a second time, mount will hang in D state; ps(1) >reports it's at text.lock.super. System cannot be cleanly shut down after that -- >shutdown(8) hangs and so does sync(1). > > Correct - much later I discovered that. "sync" and another "mount" hung in D-state, so I rebooted. I am now running without ide-scsi and have no problem using cd's. :-) Helge Hafting