Re: [PATCH 8/9] check: run tests in a systemd scope for mandatory test cleanup

Darrick J. Wong
2020-11-02T21:40:02Z

On Tue, Oct 27, 2020 at 12:02:21PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
>
> If systemd is available, run each test in its own temporary systemd
> scope. This enables the test harness to forcibly clean up all of the
> test's child processes (if it does not do so itself) so that we can move
> into the post-test unmount and check cleanly.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
> check | 21 ++++++++++++++++++++-
> 1 file changed, 20 insertions(+), 1 deletion(-)
>
>
> diff --git a/check b/check
> index 5072dd82..47c72fa2 100755
> --- a/check
> +++ b/check
> @@ -521,6 +521,11 @@ _expunge_test()
> return 0
> }
>
> +# Can we run systemd scopes?
> +HAVE_SYSTEMD_SCOPES=
> +systemd-run --quiet --unit "fstests-check" --scope bash -c "exit 77" &> /dev/null
> +test $? -eq 77 && HAVE_SYSTEMD_SCOPES=yes
> +
> # Make the check script unattractive to the OOM killer...
> OOM_SCORE_ADJ="/proc/self/oom_score_adj"
> test -w ${OOM_SCORE_ADJ} && echo -1000 > ${OOM_SCORE_ADJ}
> @@ -528,8 +533,22 @@ test -w ${OOM_SCORE_ADJ} && echo -1000 > ${OOM_SCORE_ADJ}
> # ...and make the tests themselves somewhat more attractive to it, so that if
> # the system runs out of memory it'll be the test that gets killed and not the
> # test framework.
> +#
> +# If systemd is available, run the entire test script in a scope so that we can
> +# kill all subprocesses of the test if it fails to clean up after itself. This
> +# is essential for ensuring that the post-test unmount succeeds.
> _run_seq() {
> - bash -c "test -w ${OOM_SCORE_ADJ} && echo 250 > ${OOM_SCORE_ADJ}; exec ./$seq"
> + local cmd=(bash -c "test -w ${OOM_SCORE_ADJ} && echo 250 > ${OOM_SCORE_ADJ}; exec ./$seq")
> +
> + if [ -n "${HAVE_SYSTEMD_SCOPES}" ]; then
> + local unit="$(systemd-escape "fs$seq").scope"
> + systemd-run --quiet --unit "${unit}" --scope "${cmd[@]}"

/me discovers that systemd preserves failed transient scopes (where
"failed" means the processes get killed, not that they return nonzero),
so this patch has to reset-failed the scope in case the user calls
fstests before rebooting.

Hence, self NAK.

--D

> + res=$?
> + systemctl stop "${unit}" &> /dev/null
> + return "${res}"
> + else
> + "${cmd[@]}"
> + fi
> }
>
> _detect_kmemleak
>