Re: [PATCH v5] ext4/056: add a check to make sure ext4 uuid ioctls get/set during fsstress.

[Zorro Lang <zlang@redhat.com>]

On Wed, Jul 20, 2022 at 07:42:25AM -0400, Theodore Ts'o wrote:
> On Wed, Jul 20, 2022 at 06:09:49PM +0800, Zorro Lang wrote:
> > On Tue, Jul 19, 2022 at 05:02:56PM -0700, Jeremy Bongio wrote:
> > > +# Override the default cleanup function.
> > > +_cleanup()
> > > +{
> > > +        cd /
> > > +        rm -r -f $tmp.*
> > > +        kill -9 $fsstress_pid 2>/dev/null;
> > > +        wait $fsstress_pid > /dev/null 2>&1
> > 
> > I think "wait" is enough. With this change, it's good to me.
> 
> The kill -9 is needed, because otherwise the test will run for a
> **very** long time.  The reason for it is because of the -n 999999 in

Sure, I mean:

  kill -9 $fsstress_pid 2>/dev/null
  wait

Not remove the "kill" line :)

> fstress_args:
> 
> > > +# Begin fsstress while modifying UUID
> > > +fsstress_args=$(_scale_fsstress_args -d $SCRATCH_MNT -p 15 -n 999999)
> > > +$FSSTRESS_PROG $fsstress_args > /dev/null 2>&1 &
> > > +fsstress_pid=$!
> 
> We could adjust the number of loops to a more reasonable number, but
> then test becomes less reliable, since depending on the storage device
> (e.g., cheap USB thumb drive found in the checkout counter at a
> convenience store, vs. a high-end NVMe SSD) and the overall speed of
> the system, a different number of loops will be needed.
> 
> Given that we're *only* using the fsstress as an antogonist while we
> are changing the UUID of the file system 20 times, killing the
> fsstress once we're done with the UUID runs is sufficient, I would
> argue.
> 
> Also, Jeremy, it looks like you haven't updated your xfstests-dev
> repository in a few weeks.  Since you started this project, ext4/056
> has been assigned, and there has been some new helper programs added
> which caused patch conflicts in src/Makefile and in .gitignore.  They
> were pretty trivial to fix up the patch conflicts (which I've done in
> my xfstests-dev tree), but it's best practice to rebase on top of
> origin/for-next and re-test just to make sure there haven't been some
> major change in the fstests common scripts that might catch your test
> out.

Thanks for pointing out that, yes, better to rebase to latest fstests
for-next branch.

> 
> Also, feel free to add my:
> 
> Reviewed-by: Theodore Ts'o <tytso@mit.edu>

Sure,

Thanks,
Zorro

> 
> Cheers,
> 
> 						- Ted
>