From db296e9f3e78b9694464dbde956d04f6621125ed Mon Sep 17 00:00:00 2001

From: Lennart Poettering <lennart@poettering.net>

Date: Tue, 5 Nov 2013 22:17:03 +0100

Subject: [PATCH] shutdown: trim the cgroup tree on loop iteration

This way we leave the cgroup empty before exiting in a container which

makes sure the container manager will get cgroup notification event

https://bugs.freedesktop.org/show_bug.cgi?id=68370

https://bugzilla.redhat.com/show_bug.cgi?id=988883

---

 src/core/shutdown.c | 16 +++++++++++++---

 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/core/shutdown.c b/src/core/shutdown.c

index 4709746..ea02b60 100644

--- a/src/core/shutdown.c

+++ b/src/core/shutdown.c

@@ -46,6 +46,7 @@

 #include "virt.h"

 #include "watchdog.h"

 #include "killall.h"

+#include "cgroup-util.h"

 #define FINALIZE_ATTEMPTS 50

@@ -131,12 +132,12 @@ static int pivot_to_new_root(void) {

 }

 int main(int argc, char *argv[]) {

-        _cleanup_free_ char *line = NULL;

-        int cmd, r;

-        unsigned retries;

         bool need_umount = true, need_swapoff = true, need_loop_detach = true, need_dm_detach = true;

         bool in_container, use_watchdog = false;

+        _cleanup_free_ char *line = NULL, *cgroup = NULL;

         char *arguments[3];

+        unsigned retries;

+        int cmd, r;

         /* suppress shutdown status output if 'quiet' is used  */

         r = read_one_line_file("/proc/cmdline", &line);

@@ -186,6 +187,8 @@ int main(int argc, char *argv[]) {

                 goto error;

         }

+        cg_get_root_path(&cgroup);

+

         use_watchdog = !!getenv("WATCHDOG_USEC");

         /* lock us into memory */

@@ -210,6 +213,13 @@ int main(int argc, char *argv[]) {

                 if (use_watchdog)

                         watchdog_ping();

+                /* Let's trim the cgroup tree on each iteration so

+                   that we leave an empty cgroup tree around, so that

+                   container managers get a nice notify event when we

+                   are down */

+                if (cgroup)

+                        cg_trim(SYSTEMD_CGROUP_CONTROLLER, cgroup, false);

+

                 if (need_umount) {

                         log_info("Unmounting file systems.");

                         r = umount_all(&changed);