systemd/0048-core-report-root-cgrou...

67 lines
2.4 KiB
Diff

From 98bac6058c919071ba6b7860b925decacafdc822 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Tue, 25 Aug 2015 20:42:50 +0200
Subject: [PATCH] core: report root cgroup as "/" over the bus
Internally, the root cgroup is stored as the empty string in
Unit.cgroup_path, and "no cgroup" as NULL. Unfortunately, D-Bus does not
know a NULL concept, hence when reporting the cgroup to clients we
should turn the root cgroup into "/", and leave the empty string for the
"no cgroup" case.
This should make sure that "systemctl status -- -.slice" works correctly
and shows the entire cgroup tree.
---
src/core/dbus-unit.c | 32 +++++++++++++++++++++++++++++++-
1 file changed, 31 insertions(+), 1 deletion(-)
diff --git a/src/core/dbus-unit.c b/src/core/dbus-unit.c
index 1892725..0a9effd 100644
--- a/src/core/dbus-unit.c
+++ b/src/core/dbus-unit.c
@@ -697,10 +697,40 @@ static int property_get_cpu_usage(
return sd_bus_message_append(reply, "t", ns);
}
+static int property_get_cgroup(
+ sd_bus *bus,
+ const char *path,
+ const char *interface,
+ const char *property,
+ sd_bus_message *reply,
+ void *userdata,
+ sd_bus_error *error) {
+
+ Unit *u = userdata;
+ const char *t;
+
+ assert(bus);
+ assert(reply);
+ assert(u);
+
+ /* Three cases: a) u->cgroup_path is NULL, in which case the
+ * unit has no control group, which we report as the empty
+ * string. b) u->cgroup_path is the empty string, which
+ * indicates the root cgroup, which we report as "/". c) all
+ * other cases we report as-is. */
+
+ if (u->cgroup_path)
+ t = isempty(u->cgroup_path) ? "/" : u->cgroup_path;
+ else
+ t = "";
+
+ return sd_bus_message_append(reply, "s", t);
+}
+
const sd_bus_vtable bus_unit_cgroup_vtable[] = {
SD_BUS_VTABLE_START(0),
SD_BUS_PROPERTY("Slice", "s", property_get_slice, 0, 0),
- SD_BUS_PROPERTY("ControlGroup", "s", NULL, offsetof(Unit, cgroup_path), 0),
+ SD_BUS_PROPERTY("ControlGroup", "s", property_get_cgroup, 0, 0),
SD_BUS_PROPERTY("MemoryCurrent", "t", property_get_current_memory, 0, 0),
SD_BUS_PROPERTY("CPUUsageNSec", "t", property_get_cpu_usage, 0, 0),
SD_BUS_VTABLE_END
--
2.4.3