Re: [PATCH blktests] bcache: add bcache/001

On Tue, Jan 20, 2026 at 11:56:33PM -0800, Christoph Hellwig wrote:
> On Tue, Jan 20, 2026 at 02:28:18PM +0100, Daniel Wagner wrote:
> > So far we are missing tests for bcache. Besides a relative simple
> > setup/teardown tests add also the corresponding infrastructure. More
> > tests are to be expected to depend on this.
> > 
> > _create_bcache/_remove_bcache are tracking the resources and if anything
> > is missing it will complain.
> 
> Not really an expert on bcache, and not that much in blktests either,
> but having some testing for bcache readabily available is fantastic!

I think so too. Anyway, I'll hope, I figure out to make it more
stable/consistent. 
 
> > Note: to run this tests blktests TEST_CASE_DEV_ARRAY needs to be set:
> > 
> >   # cat config
> >   TEST_CASE_DEV_ARRAY[bcache/*]="/dev/nvme0n1 /dev/vdb /dev/vdc"
> 
> Can you add a blurb to Documentation/running-tests.md about this?
> 
> I also wonder if we could have a generic TEST_CASE_DEV_ARRAY that
> would just work for all tests needing multiple devices?

Sure, I'll update the documentation.

On this note, It took me a while to understand that using
TEST_DEVS="/dev/nvme0n1 /dev/vdb /dev/vdc" is not populating the
TEST_DEV_ARRAY array.

Commit 653ace845911 ("check, new: introduce test_device_array()")
explains why:

    As to the test target devices defined in TEST_DEVS variable, blktests
    assumes that each test case with test_device() function is run for each
    single device defined in TEST_DEVS. On the other hand, it is suggested
    to support a test case for not a single device but multiple devices.

Maybe we could add a default config with all options listed and
documented but commented out.