zdtm: Add test to check global properties of cgroup-v2 are preserved

Check that CRIU can checkpoint/restore global properties in cgroup-v2 properly.

Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com>

test/zdtm/static/Makefile

@@ -386,6 +386,7 @@ TST_DIR		=				\
 		cgroup02			\
 		cgroup03			\
 		cgroup04			\
+		cgroupv2_00			\
 		cgroup_ifpriomap		\
 		cgroup_ignore			\
 		cgroup_stray			\

test/zdtm/static/cgroupv2_00.c

@@ -0,0 +1,86 @@
+#include <sys/mount.h>
+#include <sys/stat.h>
+
+#include "zdtmtst.h"
+
+const char *test_doc = "Check that some cgroup-v2 properties in kernel controllers are preserved";
+const char *test_author = "Bui Quang Minh <minhquangbui99@gmail.com>";
+
+char *dirname;
+TEST_OPTION(dirname, string, "cgroup-v2 directory name", 1);
+const char *cgname = "subcg00";
+
+int main(int argc, char **argv)
+{
+	char path[1024], aux[1024];
+	int ret = -1;
+
+	test_init(argc, argv);
+
+	if (mkdir(dirname, 0700) < 0 && errno != EEXIST) {
+		pr_perror("Can't make dir");
+		return -1;
+	}
+
+	if (mount("cgroup2", dirname, "cgroup2", 0, NULL)) {
+		pr_perror("Can't mount cgroup-v2");
+		return -1;
+	}
+
+	sprintf(path, "%s/%s", dirname, cgname);
+	if (mkdir(path, 0700) < 0 && errno != EEXIST) {
+		pr_perror("Can't make dir");
+		goto out;
+	}
+
+	/* Make cpuset controllers available in children directory */
+	sprintf(path, "%s/%s", dirname, "cgroup.subtree_control");
+	sprintf(aux, "%s", "+cpuset");
+	if (write_value(path, aux))
+		goto out;
+
+	sprintf(path, "%s/%s/%s", dirname, cgname, "cgroup.subtree_control");
+	sprintf(aux, "%s", "+cpuset");
+	if (write_value(path, aux))
+		goto out;
+
+	sprintf(path, "%s/%s/%s", dirname, cgname, "cgroup.type");
+	sprintf(aux, "%s", "threaded");
+	if (write_value(path, aux))
+		goto out;
+
+	sprintf(path, "%s/%s/%s", dirname, cgname, "cgroup.procs");
+	sprintf(aux, "%d", getpid());
+	if (write_value(path, aux))
+		goto out;
+
+	test_daemon();
+	test_waitsig();
+
+	sprintf(path, "%s/%s/%s", dirname, cgname, "cgroup.subtree_control");
+	if (read_value(path, aux, sizeof(aux)))
+		goto out;
+
+	if (strcmp(aux, "cpuset\n")) {
+		fail("cgroup.subtree_control mismatches");
+		goto out;
+	}
+
+	sprintf(path, "%s/%s/%s", dirname, cgname, "cgroup.type");
+	if (read_value(path, aux, sizeof(aux)))
+		goto out;
+
+	if (strcmp(aux, "threaded\n")) {
+		fail("cgroup.type mismatches");
+		goto out;
+	}
+
+	pass();
+
+	ret = 0;
+
+out:
+	sprintf(path, "%s", dirname);
+	umount(path);
+	return ret;
+}

test/zdtm/static/cgroupv2_00.checkskip

@@ -0,0 +1,11 @@
+#!/bin/bash
+
+if [ -f /sys/fs/cgroup/cgroup.controllers ]; then
+	grep -q "cpuset" /sys/fs/cgroup/cgroup.controllers && exit 0
+fi
+
+if [ -d /sys/fs/cgroup/unified ]; then
+	grep -q "cpuset" /sys/fs/cgroup/unified/cgroup.controllers && exit 0
+fi
+
+exit 1

test/zdtm/static/cgroupv2_00.desc

@@ -0,0 +1 @@
+{'flavor': 'h ns', 'flags': 'suid', 'opts': '--manage-cgroups=full'}

test/zdtm/static/cgroupv2_00.hook

@@ -0,0 +1,16 @@
+#!/bin/bash
+
+[ "$1" == "--clean" -o "$1" == "--pre-restore" ] || exit 0
+
+set -e
+cgname="subcg00"
+tname=$(mktemp -d cgclean.XXXXXX)
+mount -t cgroup2 cgroup2 $tname
+
+echo "Cleaning $tname"
+echo "-cpuset" > "$tname/$cgname/cgroup.subtree_control"
+
+set +e
+rmdir "$tname/$cgname"
+umount "$tname"
+rmdir "$tname"