DevLabel / JFS FileSystem...

Gary_Lerhaupt@Dell.com Gary_Lerhaupt at Dell.com
Mon Apr 12 12:04:00 CDT 2004


Very interesting.  The portion of the partition_uuid code you tweaked
came directly from mount, so it sounds like there is a shared bug here.
Interestingly, the comment right there suggests that version 1.0 jffs
partitions (OS/2 compatible) have no UUIDs.  Apparently, even though
your partition is returning that it is jffs version 1, it obviously is
not since it does return a uuid with your hack.  Just to be sure, I ran
mkfs.jfs on a RHEL3 box here and devlabel also returned all 0s for the
UUID.

I'm including Andries Brouwer, the util-linux maintainer, to get his
insight.  Andries, thoughts?

Gary  

> -----Original Message-----
> From: Brad Viviano [mailto:viviano at geomagic.com]
> Sent: Monday, April 12, 2004 11:19 AM
> To: Lerhaupt, Gary
> Cc: linux-poweredge at Dell.com
> Subject: Re: DevLabel / JFS FileSystem...
> 
> 
> Gary,
> 	Thanks for writting back.  When I run:
> 
> 	mount -U "93de61d5-7f85-481e-bd5b-57748e5ef3c7" /raid2e
> 
> it comes back with: "mount: no such partition found".  This 
> was with the
> RedHat compiled versions of util-linux-2.11y, I also 
> downloaded, compiled and
> tried mount from util-linux-2.11z, and util-linux-2.12pre 
> from kernel.org with
> the same results.
> 
> I looked at partition_uuid.c inside the get_label_uuid 
> function, the code
> dealing with reading the JFS SuperBlock.  Although this is in 
> no uncertain
> terms a complete hack, I modifed line 172 (From devlabel-0.46.01):
> 
> 	if (assemble4le(jfssb.s_version) == 1) {
> 
> to be:
> 
> 	if (assemble4le(jfssb.s_version) == 2) {
> 
> Which forces the "else" condition, and I now get this from 
> the newly rebuilt
> partition_uuid:
> 
> # ./partition_uuid /dev/sde9
> 93de61d5-7f85-481e-bd5b-57748e5ef3c7
> 
> Which is the correct UUID for that volume.  I also modified 
> get_label_uuid.c
> in both util-linux-2.11z and util-linux-2.12pre in the same 
> way and mount now
> mounts jfs file systems via UUID.  So it seems that either the JFS
> "version number" should of been reved from version 1, or the 
> SuperBlock of
> the JFS file system is more complicated then get_volume_label 
> allows for, and
> needs to be updated (So is this a general Linux problem, or 
> an IBM problem :).
> I am not sure what the correct step is in getting this problem fixed.
> 
> The hack works for me, and I can now use devlabel on my JFS 
> filesystem, and
> it isn't a real concern for me since I don't have any older 
> OS/2 based file
> systems on this 2650.  But I would like to report this, or 
> get this fixed in
> general since I don't think this is actually a devlabel 
> problem, but a problem
> inside of either get_label_uuid from the util-linux package, 
> or whoever is
> responsible for maintaining the JFS code.
> 
> Does anyone know which group I should report this problem to, 
> or where I can
> look to see if its a know issue with JFS file systems.
> 
> 	Thanks,
> 		-Brad Viviano
> 
> On 04/12/2004, Gary_Lerhaupt at Dell.com said something along 
> the lines of:
> > Well, certainly something is messed up.  However, the bulk 
> of the code
> > taken to create partition_uuid was taken verbatim from mount.  This
> > should include jfs uuid support.  In fact, can you attempt 
> to use mount
> > to mount by UUID and see if that is successful?
> > 
> > Gary
> > 
> > > -----Original Message-----
> > > From: linux-poweredge-admin at dell.com
> > > [mailto:linux-poweredge-admin at dell.com]On Behalf Of Brad Viviano
> > > Sent: Monday, April 12, 2004 9:13 AM
> > > To: linux-poweredge at dell.com
> > > Subject: DevLabel / JFS FileSystem...
> > > 
> > > 
> > > This might be alittle off topic, but since devlabel is hosted 
> > > by Dell, I
> > > thought someone monitoring this list might know the answer to 
> > > my question.  I
> > > have a PE2650 running RHEL 3 Update 1.  I am trying to use 
> > > DevLabel with a JFS
> > > based file system which is located on a RAID5 drive set 
> inside my 2650
> > > connected to the Perc3/DI controller.  When I run devlabel on 
> > > one of the
> > > partitions it tells me:
> > > 
> > > Uniqueness check failed.  The following devices have the 
> same UUID:
> > > /dev/sde7
> > > /dev/sde8
> > > /dev/sde9
> > > 
> > > Failure.
> > > The device UUID for /dev/sde7 is identical to other devices 
> > > on your system.
> > > Because of this, you cannot use devlabel with this device.
> > > 
> > > sde7, sde8, and sde9 are all JFS file systems.  I have traced 
> > > the problem to
> > > /usr/bin/partition_uuid.  When I run that on any of the 
> > > filesystems that are
> > > JFS based it always returns 
> > > "00000000-0000-0000-0000-000000000000".  But
> > > partition_uuid works fine for EXT3/SWAP type file systems.  I 
> > > have loaded the
> > > latest RPM from linux.dell.com/devlabel with no affect.  
> > > blkid /dev/sde7
> > > returns the correct information:
> > > 
> > > /dev/sde7: LABEL="raid2c" 
> > > UUID="e73ea11d-3019-4510-9f67-2160be89279a" TYPE="jfs"
> > > 
> > > So I know it is getting a LABEL/UUID.  Is there some patch to 
> > > devlabel, or do
> > > I need to do something else (Some tune paramiter) on JFS file 
> > > systems to get
> > > devlabel to read the UUID on a JFS filesytem.
> > > 
> > > In case anyone is wondering why I don't just use "LABEL=" in 
> > > /etc/fstab, I was
> > > using that, but as it turns out my PE2650 crashed last night 
> > > and left the JFS
> > > file systems in an unclean state, at reboot I was getting 
> > > errors saying it was
> > > unable to locate drive with LABEL=raid2c, but my EXT3 
> > > FileSystems using
> > > devlabel mounted without issue.  Turns out the system can not 
> > > read the LABEL=
> > > value off a dirty JFS file system, once I manually ran 
> > > jfs_fsck /dev/sde7 I
> > > was able to mount without issue.  So I would like to switch 
> > > to devlabel for
> > > my JFS file systems.  Any ideas?
> > > 
> > > 	Thanks,
> > > 		-Brad
> > > 
> > > -- 
> > > +-------------------------------------------------------------
> > > -------------+
> > > | viviano at geomagic.com          Systems Support          
> > > Raindrop Geomagic |
> > > +-------------------------------------------------------------
> > > -------------+
> > > 
> > > _______________________________________________
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> > > 
> 
> -- 
> +-------------------------------------------------------------
> -------------+
> | viviano at geomagic.com          Systems Support          
> Raindrop Geomagic |
> +-------------------------------------------------------------
> -------------+
> 




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