Re: [PATCH] xfs: Print XFS UUID on mount and umount events.

[Dave Chinner <david@fromorbit.com>]

On Thu, Nov 03, 2022 at 02:32:52PM +0100, Lukas Czerner wrote:
> On Tue, Nov 01, 2022 at 12:19:06PM -0500, Eric Sandeen wrote:
> > From: Lukas Herbolt <lukas@herbolt.com>
> > 
> > As of now only device names are printed out over __xfs_printk().
> > The device names are not persistent across reboots which in case
> > of searching for origin of corruption brings another task to properly
> > identify the devices. This patch add XFS UUID upon every mount/umount
> > event which will make the identification much easier.
> > 
> > Signed-off-by: Lukas Herbolt <lukas@herbolt.com>
> > [sandeen: rebase onto current upstream kernel]
> > Signed-off-by: Eric Sandeen <sandeen@redhat.com>
> 
> Hi,
> 
> it is a simple enough, nonintrusive change so it may not really matter as
> much, but I was wondering if there is a way to map the device name to
> the fs UUID already and I think there may be.
> 
> I know that udev daemon is constantly scanning devices then they are
> closed in order to be able to read the signatures. It should know
> exactly what is on the device and I know it is able to track the history
> of changes. What I am not sure about is whether it is already logged
> somewhere?
> 
> If it's not already, maybe it can be done and then we can cross
> reference kernel log with udev log when tracking down problems to see
> exactly what is going on without needing to sprinkle UUIDs in kernel log ?
> 
> Any thoughts?

Don't like it. Emitting the UUID on the fs mount/unmount log message
is a trivial change that has zero impact on anything as well as
being really easy for log scrapers to deal with.

Screwing around with udev to manage and/or find this correlationi
is ... unnecssarily awful.

-Dave.
-- 
Dave Chinner
david@fromorbit.com