Re: Widespread test setup template problems (was Re: [PATCH] generic: fix cleanup function for test 490)

[Eryu Guan <guaneryu@gmail.com>]

On Fri, May 25, 2018 at 11:23:36AM +1000, Dave Chinner wrote:
> On Fri, May 25, 2018 at 10:59:40AM +1000, Dave Chinner wrote:
> > On Fri, May 25, 2018 at 10:29:14AM +1000, Dave Chinner wrote:
> > > On Mon, May 21, 2018 at 10:54:00AM +0800, Eryu Guan wrote:
> > > > On Mon, May 21, 2018 at 12:41:44PM +1000, Dave Chinner wrote:
> > > > > On Sun, May 20, 2018 at 02:45:17PM -0400, Theodore Ts'o wrote:
> > > > > > generic/490 fails because cleanup tries to delete . and .. since $tmp
> > > > > > is left unset, and so "rm -f $tmp.*" does nothing useful.  Instead
> > > > > > delete temp files created by seek_sanity_test.
> > > > > > 
> > > > > > Signed-off-by: Theodore Ts'o <tytso@mit.edu>
> > > > > > ---
> > > > > >  tests/generic/490 | 2 +-
> > > > > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > > > > 
> > > > > > diff --git a/tests/generic/490 b/tests/generic/490
> > > > > > index b5042c2e..c0335ca0 100755
> > > > > > --- a/tests/generic/490
> > > > > > +++ b/tests/generic/490
> > > > > > @@ -49,7 +49,7 @@ _require_test_program "seek_sanity_test"
> > > > > >  _cleanup()
> > > > > >  {
> > > > > >  	cd /
> > > > > > -	rm -f $tmp.*
> > > > > > +	rm -f $base_test_file*
> > > > > >  }
> > > > > >  
> > > > > >  $here/src/seek_sanity_test -s 19 -e 20 $base_test_file > $seqres.full 2>&1 ||
> > > > > 
> > > > > This is wrong. $tmp must always be set in a test, as the
> > > > > infrastructure uses it. Failing to set $tmp will result in stray
> > > > > files being spewed around the place by the test and not cleaned up.
> > > > > Hence the "rm -f $tmp.*" line must stay, the normal tmp=/tmp/$$ line
> > > > > added to the test preamble, and then you can remove the base test
> > > > > file...
> > > > 
> > > > Yeah, I wanted to point that out too. So always using the './new' script
> > > > is the recommended way to write new test, it already puts all the common
> > > > setups (including the 'tmp=/tmp/$$' definition and 'rm -f $tmp.*'
> > > > cleanup) in the test template.
> > > 
> > > Is there a fix committed for this yet? This bug causes the test to
> > > run rm -f .* in the root directory of the machine....
> > 
> > BTW, in looking at what was missing from the test setup template in
> > this test, I noticed that it was also missing the setup of $here,
> > removal of $seqres.full, etc
> > 
> > SO I checked on how many tests fail to set $here, which is used in
> > the common/rc test infrastructure:
> > 
> > $ git grep -l 'here=`pwd`' tests/ > t.t
> > $ ls -1 tests/*/*[0-9] |grep -v out > tt.t
> > $ diff -u t.t tt.t |grep ^+ |wc -l
> > 137
> > $
> > 
> > And, well, this is potentially very dangerous:
> > 
> > $ git grep -l 'tmp=/tmp/\$\$' tests/ > t.t
> > $ ls -1 tests/*/*[0-9] |grep -v out > tt.t
> > $ diff -u t.t tt.t |grep ^+ |wc -l
> > 49
> > $
> > 
> > A bunch of test use different tmp setups (e.g. mktemp -d, some put
> > them in $TEST_DIR) but many omit it completely. They really all
> > should use the same base location.
> > 
> > IOWs there's 137 tests that have $here incorrectly/not set up, and
> > 49 tests that don't initialise $tmp like they are supposed to. A
> > large number of these are relatively new tests, and the setup of
> > this variable is done by the "new" test script.
> > 
> > So why are so many new tests missing stuff that the 'new' template
> > sets up? Do we have a copy-n-paste process problem?  Should we
> > abstract out this test setup preamble so people don't keep screwing
> > it up?

That's my bad, sorry. I didn't spend much review bandwidth on test setup
preamble but focused more on test correctness.

> 
> Abstracting it out would look like the patch below. That, and moving
> to SPDX tags for the licensing text, will greatly clean up the test
> setup preamble. It will also draw a line in the sand for new tests -
> if they don't match the new setup preamble, they don't pass
> review...

I did post a patch, maybe a year ago, that went through all tests and
setup $tmp correctly (but not $here), and IIRC Amir suggested a similar
solution to your RFC patch. But that discussion only resulted in commit
81aa85deac1f ("fstests: remove tmp files properly") in the end.

> 
> Thoughts?

I have no problem with going to that direction, the common setup
preamble also makes review easier, I don't have to search for "tmp" and
"here" etc but just common/setup_test.

Thanks a lot for doing it!

Eryu

> 
> -Dave.
> -- 
> Dave Chinner
> david@fromorbit.com
> 
> 
> fstests: generic test setup preamble
> 
> From: Dave Chinner <dchinner@redhat.com>
> 
> So many tests chop random bits out of the mandaotry test setup
> preamble which leads to subtle problems and stray files being dumped
> all over the place. Create a common test preamble with hooks for
> local cleanup functions so we can prevent this in future.
> 
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> 
> ---
>  common/setup_test | 22 ++++++++++++++++++++++
>  new               | 24 ++++--------------------
>  tests/generic/001 | 19 +++++++------------
>  3 files changed, 33 insertions(+), 32 deletions(-)
> 
> diff --git a/common/setup_test b/common/setup_test
> new file mode 100644
> index 000000000000..6359ab53a8d9
> --- /dev/null
> +++ b/common/setup_test
> @@ -0,0 +1,22 @@
> +# common test setup preamble
> +# test specific cleanup is done via the local_cleanup() function now.
> +#
> +seq=`basename $0`
> +seqres=$RESULT_DIR/$seq
> +echo "QA output created by $seq"
> +
> +here=`pwd`
> +tmp=/tmp/$$
> +status=1	# failure is the default!
> +trap "_cleanup; exit \$status" 0 1 2 3 15
> +
> +_cleanup()
> +{
> +    local_cleanup
> +    cd /
> +    rm -f $tmp.*
> +}
> +
> +# get standard environment, filters and checks
> +. ./common/rc
> +. ./common/filter
> diff --git a/new b/new
> index 4eacccd3bf8b..5e7f6a3c4198 100755
> --- a/new
> +++ b/new
> @@ -181,31 +181,15 @@ cat <<End-of-File >$tdir/$id
>  #-----------------------------------------------------------------------
>  #
>  
> -seq=\`basename \$0\`
> -seqres=\$RESULT_DIR/\$seq
> -echo "QA output created by \$seq"
> +. common/setup_test
>  
> -here=\`pwd\`
> -tmp=/tmp/\$\$
> -status=1	# failure is the default!
> -trap "_cleanup; exit \\\$status" 0 1 2 3 15
> -
> -_cleanup()
> -{
> -	cd /
> -	rm -f \$tmp.*
> -}
> -
> -# get standard environment, filters and checks
> -. ./common/rc
> -. ./common/filter
> +# test exit cleanup goes here
> +local_cleanup() { true }
>  
>  # remove previous \$seqres.full before test
>  rm -f \$seqres.full
>  
> -# real QA test starts here
> -
> -# Modify as appropriate.
> +# include test specific environments here
>  _supported_fs generic
>  _supported_os Linux
>  _require_test
> diff --git a/tests/generic/001 b/tests/generic/001
> index 0edd41f1e2cc..e1dd2e3202e3 100755
> --- a/tests/generic/001
> +++ b/tests/generic/001
> @@ -31,25 +31,20 @@
>  #-----------------------------------------------------------------------
>  #
>  
> -seq=`basename $0`
> -seqres=$RESULT_DIR/$seq
> -echo "QA output created by $seq"
> +. common/setup_test
>  
> -# get standard environment, filters and checks
> -. ./common/rc
> -. ./common/filter
> +# test exit cleanup goes here
> +local_cleanup() { true }
>  
> -tmp=/tmp/$$
> -here=`pwd`
> -status=1
> -done_cleanup=false
> -trap "_cleanup; rm -f $tmp.*; exit \$status" 0 1 2 3 15
> +# remove previous $seqres.full before test
> +rm -f $seqres.full
>  
> -# real QA test starts here
> +# include test specific environments here
>  _supported_fs generic
>  _supported_os Linux
>  _require_test
>  
> +done_cleanup=false
>  verbose=true
>  verify=$here/verify_fill
>