[CRIU] [PATCH v3] zdtm: cleanup zdtmtst and zdtmtst.defaultroot cgroups after finishing test

[Pavel Tikhomirov]

After running criu test, docker on the node becomes unusable, as it is
confused by our leftover cgroups. Surely docker should be fixed to
ignore custom cgroups (https://github.com/moby/moby/issues/37601), but
we should not leave them after test also.

v2: rmdir the holder only if it exists, remove racy wait and remove
wrongly added cleanup method in class criu
v3: bring back missed semicolon

Signed-off-by: Pavel Tikhomirov <ptikhomirov at virtuozzo.com>
---
 test/zdtm.py             | 11 +++++++++++
 test/zdtm_umount_cgroups | 16 ++++++++++++++++
 2 files changed, 27 insertions(+)
 create mode 100755 test/zdtm_umount_cgroups

diff --git a/test/zdtm.py b/test/zdtm.py
index c0ea65b2e..dc7c6ebe4 100755
--- a/test/zdtm.py
+++ b/test/zdtm.py
@@ -569,6 +569,10 @@ flavors_codes = dict(zip(range(len(flavors)), sorted(flavors.keys())))
 			subprocess.check_call(["make", "-C", "zdtm/"])
 		subprocess.check_call(["flock", "zdtm_mount_cgroups.lock", "./zdtm_mount_cgroups"])
 
+	@staticmethod
+	def cleanup():
+		subprocess.check_call(["flock", "zdtm_mount_cgroups.lock", "./zdtm_umount_cgroups"])
+
 
 class inhfd_test:
 	def __init__(self, name, desc, flavor, freezer):
@@ -674,6 +678,10 @@ flavors_codes = dict(zip(range(len(flavors)), sorted(flavors.keys())))
 	def available():
 		pass
 
+	@staticmethod
+	def cleanup():
+		pass
+
 
 class groups_test(zdtm_test):
 	def __init__(self, name, desc, flavor, freezer):
@@ -2226,3 +2234,6 @@ criu.available()
 	tst.available()
 
 opts['action'](opts)
+
+for tst in test_classes.values():
+	tst.cleanup()
diff --git a/test/zdtm_umount_cgroups b/test/zdtm_umount_cgroups
new file mode 100755
index 000000000..75a8ea28f
--- /dev/null
+++ b/test/zdtm_umount_cgroups
@@ -0,0 +1,16 @@
+#!/bin/sh
+
+# Lets delete all test controllers after executing tests.
+
+cat /proc/self/cgroup | grep -q zdtmtst.defaultroot || exit 0
+
+tdir=`mktemp -d zdtm.XXXXXX`
+for i in "zdtmtst" "zdtmtst.defaultroot"; do
+	mount -t cgroup -o none,name=$i zdtm $tdir || { rmdir $tdir; exit 1; }
+	# remove a fake group if exists
+	if [ -d "$tdir/holder" ]; then
+		rmdir $tdir/holder || { umount -l $tdir && rmdir $tdir; exit 1; }
+	fi
+	umount -l $tdir || exit 1;
+done
+rmdir $tdir
-- 
2.17.1