The test case repeats creating and deleting a loop device. This generates many udev events and makes following test cases fail. To avoid the unexpected test case failures, drain the udev events. For that purpose, introduce the helper function _drain_udev_events(). When systemd-udevd service is running, restart it to discard the events quickly. When systemd-udevd service is not available, call "udevadm settle", which takes longer time to drain the events. Link: https://github.com/linux-blktests/blktests/issues/181 Reported-by: Yi Zhang <yi.zhang@xxxxxxxxxx> Suggested-by: Bart Van Assche <bvanassche@xxxxxxx> Suggested-by: Daniel Wagner <dwagner@xxxxxxx> Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@xxxxxxx> --- Changes from v1: * Added "udevadm settle" in case systemd-udevd.service is not available * Introduced _drain_udev_events() common/rc | 9 +++++++++ tests/loop/010 | 5 +++++ 2 files changed, 14 insertions(+) diff --git a/common/rc b/common/rc index 72441ab..dfc389f 100644 --- a/common/rc +++ b/common/rc @@ -544,6 +544,15 @@ _systemctl_stop() { done } +_drain_udev_events() { + if command -v systemctl &>/dev/null && + systemctl is-active --quiet systemd-udevd; then + systemctl restart systemd-udevd.service + else + udevadm settle --timeout=900 + fi +} + # Run the given command as NORMAL_USER _run_user() { su "$NORMAL_USER" -c "$1" diff --git a/tests/loop/010 b/tests/loop/010 index 309fd8a..b1a4926 100755 --- a/tests/loop/010 +++ b/tests/loop/010 @@ -78,5 +78,10 @@ test() { if _dmesg_since_test_start | grep --quiet "$grep_str"; then echo "Fail" fi + + # The repeated loop device creations and deletions generated so many + # udev events. Drain the events to not influence following test cases. + _drain_udev_events + echo "Test complete" } -- 2.50.1
