test: add test for cgroup v2 freezer support

test/TEST-38-FREEZER/Makefile

@@ -0,0 +1 @@
+../TEST-01-BASIC/Makefile

test/TEST-38-FREEZER/test.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+set -e
+TEST_DESCRIPTION="test unit freezing and thawing via DBus and systemctl"
+TEST_NO_NSPAWN=1
+. $TEST_BASE_DIR/test-functions
+
+do_test "$@" 38

test/test-functions

@@ -101,6 +101,7 @@ BASICTOOLS=(
     tar
     tee
     test
+    timeout
     touch
     tr
     true

test/units/testsuite-38-sleep.service

@@ -0,0 +1,2 @@
+[Service]
+ExecStart=/bin/sleep 3600

test/units/testsuite-38.service

@@ -0,0 +1,6 @@
+[Unit]
+Description=TEST-38-FREEZER
+
+[Service]
+ExecStart=/usr/lib/systemd/tests/testdata/units/%N.sh
+Type=oneshot

test/units/testsuite-38.sh

@@ -0,0 +1,293 @@
+#!/usr/bin/env bash
+
+set -ex
+set -o pipefail
+
+systemd-analyze log-level debug
+systemd-analyze log-target console
+
+unit=testsuite-38-sleep.service
+
+start_test_service() {
+    systemctl daemon-reload
+    systemctl start "${unit}"
+}
+
+dbus_freeze() {
+    local suffix=
+    suffix="${1##*.}"
+
+    local name="$(echo ${1%.$suffix} | sed s/-/_2d/g)"
+    local object_path="/org/freedesktop/systemd1/unit/${name}_2e${suffix}"
+
+    busctl call \
+           org.freedesktop.systemd1 \
+           "${object_path}" \
+           org.freedesktop.systemd1.Unit \
+           Freeze
+}
+
+dbus_thaw() {
+    local suffix=
+    suffix="${1##*.}"
+
+    local name="$(echo ${1%.$suffix} | sed s/-/_2d/g)"
+    local object_path="/org/freedesktop/systemd1/unit/${name}_2e${suffix}"
+
+    busctl call \
+           org.freedesktop.systemd1 \
+           "${object_path}" \
+           org.freedesktop.systemd1.Unit \
+           Thaw
+}
+
+dbus_freeze_unit() {
+    busctl call \
+           org.freedesktop.systemd1 \
+           /org/freedesktop/systemd1 \
+           org.freedesktop.systemd1.Manager \
+           FreezeUnit \
+           s \
+           "$1"
+}
+
+dbus_thaw_unit() {
+    busctl call \
+           org.freedesktop.systemd1 \
+           /org/freedesktop/systemd1 \
+           org.freedesktop.systemd1.Manager \
+           ThawUnit \
+           s \
+           "$1"
+}
+
+dbus_can_freeze() {
+    local suffix=
+    suffix="${1##*.}"
+
+    local name="$(echo ${1%.$suffix} | sed s/-/_2d/g)"
+    local object_path="/org/freedesktop/systemd1/unit/${name}_2e${suffix}"
+
+    busctl get-property \
+           org.freedesktop.systemd1 \
+           "${object_path}" \
+           org.freedesktop.systemd1.Unit \
+           CanFreeze
+}
+
+check_freezer_state() {
+    local suffix=
+    suffix="${1##*.}"
+
+    local name="$(echo ${1%.$suffix} | sed s/-/_2d/g)"
+    local object_path="/org/freedesktop/systemd1/unit/${name}_2e${suffix}"
+
+    state=$(busctl get-property \
+                   org.freedesktop.systemd1 \
+                   "${object_path}" \
+                   org.freedesktop.systemd1.Unit \
+                   FreezerState | cut -d " " -f2 | tr -d '"')
+
+    [ "$state" = "$2" ] || {
+        echo "error: unexpected freezer state, expected: $2, actual: $state" >&2
+        exit 1
+    }
+}
+
+check_cgroup_state() {
+    grep -q "frozen $2" /sys/fs/cgroup/system.slice/"$1"/cgroup.events
+}
+
+test_dbus_api() {
+    echo "Test that DBus API works:"
+    echo -n "  - Freeze(): "
+    dbus_freeze "${unit}"
+    check_freezer_state "${unit}" "frozen"
+    check_cgroup_state "$unit" 1
+    echo "[ OK ]"
+
+    echo -n "  - Thaw(): "
+    dbus_thaw "${unit}"
+    check_freezer_state "${unit}" "running"
+    check_cgroup_state "$unit" 0
+    echo "[ OK ]"
+
+    echo -n "  - FreezeUnit(): "
+    dbus_freeze_unit "${unit}"
+    check_freezer_state "${unit}" "frozen"
+    check_cgroup_state "$unit" 1
+    echo "[ OK ]"
+
+    echo -n "  - ThawUnit(): "
+    dbus_thaw_unit "${unit}"
+    check_freezer_state "${unit}" "running"
+    check_cgroup_state "$unit" 0
+    echo "[ OK ]"
+
+    echo -n "  - CanFreeze(): "
+    output=$(dbus_can_freeze "${unit}")
+    [ "$output" = "b true" ]
+    echo "[ OK ]"
+
+    echo
+}
+
+test_jobs() {
+    local pid_before=
+    local pid_after=
+    echo "Test that it is possible to apply jobs on frozen units:"
+
+    systemctl start "${unit}"
+    dbus_freeze "${unit}"
+    check_freezer_state "${unit}" "frozen"
+
+    echo -n "  - restart: "
+    pid_before=$(systemctl show -p MainPID "${unit}" --value)
+    systemctl restart "${unit}"
+    pid_after=$(systemctl show -p MainPID "${unit}" --value)
+    [ "$pid_before" != "$pid_after" ] && echo "[ OK ]"
+
+    dbus_freeze "${unit}"
+    check_freezer_state "${unit}" "frozen"
+
+    echo -n "  - stop: "
+    timeout 5s systemctl stop "${unit}"
+    echo "[ OK ]"
+
+    echo
+}
+
+test_systemctl() {
+    echo "Test that systemctl freeze/thaw verbs:"
+
+    systemctl start "$unit"
+
+    echo -n "  - freeze: "
+    systemctl freeze "$unit"
+    check_freezer_state "${unit}" "frozen"
+    check_cgroup_state "$unit" 1
+    # Freezing already frozen unit should be NOP and return quickly
+    timeout 3s systemctl freeze "$unit"
+    echo "[ OK ]"
+
+    echo -n "  - thaw: "
+    systemctl thaw "$unit"
+    check_freezer_state "${unit}" "running"
+    check_cgroup_state "$unit" 0
+    # Likewise thawing already running unit shouldn't block
+    timeout 3s systemctl thaw "$unit"
+    echo "[ OK ]"
+
+    systemctl stop "$unit"
+
+    echo
+}
+
+test_systemctl_show() {
+    echo "Test systemctl show integration:"
+
+    systemctl start "$unit"
+
+    echo -n "  - FreezerState property: "
+    state=$(systemctl show -p FreezerState --value "$unit")
+    [ "$state" = "running" ]
+    systemctl freeze "$unit"
+    state=$(systemctl show -p FreezerState --value "$unit")
+    [ "$state" = "frozen" ]
+    systemctl thaw "$unit"
+    echo "[ OK ]"
+
+    echo -n "  - CanFreeze property: "
+    state=$(systemctl show -p CanFreeze --value "$unit")
+    [ "$state" = "yes" ]
+    echo "[ OK ]"
+
+    systemctl stop "$unit"
+    echo
+}
+
+test_recursive() {
+    local slice="bar.slice"
+    local unit="baz.service"
+
+    systemd-run --unit "$unit" --slice "$slice" sleep 3600 >/dev/null 2>&1
+
+    echo "Test recursive freezing:"
+
+    echo -n "  - freeze: "
+    systemctl freeze "$slice"
+    check_freezer_state "${slice}" "frozen"
+    check_freezer_state "${unit}" "frozen"
+    grep -q "frozen 1" /sys/fs/cgroup/"${slice}"/cgroup.events
+    grep -q "frozen 1" /sys/fs/cgroup/"${slice}"/"${unit}"/cgroup.events
+    echo "[ OK ]"
+
+    echo -n "  - thaw: "
+    systemctl thaw "$slice"
+    check_freezer_state "${unit}" "running"
+    check_freezer_state "${slice}" "running"
+    grep -q "frozen 0" /sys/fs/cgroup/"${slice}"/cgroup.events
+    grep -q "frozen 0" /sys/fs/cgroup/"${slice}"/"${unit}"/cgroup.events
+    echo "[ OK ]"
+
+    systemctl stop "$unit"
+    systemctl stop "$slice"
+
+    echo
+}
+
+test_preserve_state() {
+    local slice="bar.slice"
+    local unit="baz.service"
+
+    systemd-run --unit "$unit" --slice "$slice" sleep 3600 >/dev/null 2>&1
+
+    echo "Test that freezer state is preserved when recursive freezing is initiated from outside (e.g. by manager up the tree):"
+
+    echo -n "  - freeze from outside: "
+    echo 1 > /sys/fs/cgroup/"${slice}"/cgroup.freeze
+
+    # Our state should not be affected
+    check_freezer_state "${slice}" "running"
+    check_freezer_state "${unit}" "running"
+
+    # However actual kernel state should be frozen
+    grep -q "frozen 1" /sys/fs/cgroup/"${slice}"/cgroup.events
+    grep -q "frozen 1" /sys/fs/cgroup/"${slice}"/"${unit}"/cgroup.events
+    echo "[ OK ]"
+
+    echo -n "  - thaw from outside: "
+    echo 0 > /sys/fs/cgroup/"${slice}"/cgroup.freeze
+    check_freezer_state "${unit}" "running"
+    check_freezer_state "${slice}" "running"
+    grep -q "frozen 0" /sys/fs/cgroup/"${slice}"/cgroup.events
+    grep -q "frozen 0" /sys/fs/cgroup/"${slice}"/"${unit}"/cgroup.events
+    echo "[ OK ]"
+
+    echo -n "  - thaw from outside while inner service is frozen: "
+    systemctl freeze "$unit"
+    check_freezer_state "${unit}" "frozen"
+    echo 1 > /sys/fs/cgroup/"${slice}"/cgroup.freeze
+    echo 0 > /sys/fs/cgroup/"${slice}"/cgroup.freeze
+    check_freezer_state "${slice}" "running"
+    check_freezer_state "${unit}" "frozen"
+    echo "[ OK ]"
+
+    systemctl stop "$unit"
+    systemctl stop "$slice"
+
+    echo
+}
+
+test -e /sys/fs/cgroup/system.slice/cgroup.freeze && {
+    start_test_service
+    test_dbus_api
+    test_systemctl
+    test_systemctl_show
+    test_jobs
+    test_recursive
+    test_preserve_state
+}
+
+echo OK > /testok
+exit 0