Re: [PATCH] common: remove USE_EXTERNAL

[Dave Chinner <david@fromorbit.com>]

On Mon, Apr 14, 2025 at 05:44:52PM -0700, Darrick J. Wong wrote:
> On Mon, Apr 14, 2025 at 07:42:05AM +0200, Christoph Hellwig wrote:
> > The USE_EXTERNAL variable indicates that dedicated log or RT devices are
> > in use for the scratch and possibly test device.  It gets automatically
> > set when needed and generally does not provide any benefit over simply
> > testing the SCRATCH_LOGDEV and SCRATCH_RTDEV variables.
> > 
> > Remove it and replace that test with test for SCRATCH_LOGDEV and
> > SCRATCH_RTDEV, using the more readable if-based syntaxt for all tests
> > touched by this change.
> > 
> > Signed-off-by: Christoph Hellwig <hch@lst.de>
> 
> I like this change, but it leaves me wondering why USE_EXTERNAL even
> exists in the first place?  Is that so that you could add
> TEST/SCRATCH_RTDEV to the top of a config file and set
> USE_EXTERNAL={yes,no} as a per-section variable?  e.g.
> 
> [default]
> TEST_RTDEV=/dev/sde
> SCRATCH_RTDEV=/dev/sdf
> 
> [rtstuff]
> USE_EXTERNAL=yes
> 
> [simple]
> USE_EXTERNAL=no

Right, that's the way I've been using for a few years, and it is
explicitly the way check-parallel expects external device
enablement in config sections to work....

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