From: Lennart Poettering <lennart@poettering.net>
Date: Thu, 7 Sep 2017 12:32:33 +0000 (+0200)
Subject: core: when coming back from reload/reexec, reapply all cgroup properties
X-Git-Tag: v235~60^2~16
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=58d83430e1276fe8d1224c2b5f76e756d143a375;p=thirdparty%2Fsystemd.git

core: when coming back from reload/reexec, reapply all cgroup properties

With this change we'll invalidate all cgroup settings after coming back
from a daemon reload/reexec, so that the new settings are instantly
applied.

This is useful for the BPF case, because we don't serialize/deserialize
the BPF program fd, and hence have to install a new, updated BPF program
when coming back from the reload/reexec. However, this is also useful
for the rest of the cgroup settings, as it ensures that user
configuration really takes effect wherever we can.
---

diff --git a/src/core/cgroup.c b/src/core/cgroup.c
index c6667b39c78..e9cb0d35c91 100644
--- a/src/core/cgroup.c
+++ b/src/core/cgroup.c
@@ -1533,6 +1533,7 @@ static int unit_realize_cgroup_now(Unit *u, ManagerState state) {
 }
 
 static void unit_add_to_cgroup_queue(Unit *u) {
+        assert(u);
 
         if (u->in_cgroup_queue)
                 return;
diff --git a/src/core/unit.c b/src/core/unit.c
index 5ed57644551..68295d64455 100644
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -3205,6 +3205,11 @@ int unit_deserialize(Unit *u, FILE *f, FDSet *fds) {
         if (!dual_timestamp_is_set(&u->state_change_timestamp))
                 dual_timestamp_get(&u->state_change_timestamp);
 
+        /* Let's make sure that everything that is deserialized also gets any potential new cgroup settings applied
+         * after we are done. For that we invalidate anything already realized, so that we can realize it again. */
+        unit_invalidate_cgroup(u, _CGROUP_MASK_ALL);
+        unit_invalidate_cgroup_bpf(u);
+
         return 0;
 }