Re: [PATCH 2/2] selftests: ublk: don't take same backing file for more than one ublk devices

[Ming Lei <ming.lei@redhat.com>]

On Mon, Jun 23, 2025 at 10:54:58AM -0700, Caleb Sander Mateos wrote:
> On Sun, Jun 22, 2025 at 6:19 PM Ming Lei <ming.lei@redhat.com> wrote:
> >
> > Don't use same backing file for more than one ublk devices, and avoid
> > concurrent write on same file from more ublk disks.
> >
> > Fixes: 8ccebc19ee3d ("selftests: ublk: support UBLK_F_AUTO_BUF_REG")
> > Signed-off-by: Ming Lei <ming.lei@redhat.com>
> > ---
> >  tools/testing/selftests/ublk/test_stress_03.sh | 5 +++--
> >  1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/tools/testing/selftests/ublk/test_stress_03.sh b/tools/testing/selftests/ublk/test_stress_03.sh
> > index 6eef282d569f..3ed4c9b2d8c0 100755
> > --- a/tools/testing/selftests/ublk/test_stress_03.sh
> > +++ b/tools/testing/selftests/ublk/test_stress_03.sh
> > @@ -32,22 +32,23 @@ _create_backfile 2 128M
> >  ublk_io_and_remove 8G -t null -q 4 -z &
> >  ublk_io_and_remove 256M -t loop -q 4 -z "${UBLK_BACKFILES[0]}" &
> >  ublk_io_and_remove 256M -t stripe -q 4 -z "${UBLK_BACKFILES[1]}" "${UBLK_BACKFILES[2]}" &
> > +wait
> 
> Why is wait necessary here? It looks like __run_io_and_remove, which
> is called from run_io_and_remove, already ends with a wait. Am I
> missing something?

All tests share the three backing files, this way just avoids concurrent
write to the same file from each test/ublk device.



Thanks,
Ming