core: general cgroup rework

Replace the very generic cgroup hookup with a much simpler one. With
this change only the high-level cgroup settings remain, the ability to
set arbitrary cgroup attributes is removed, so is support for adding
units to arbitrary cgroup controllers or setting arbitrary paths for
them (especially paths that are different for the various controllers).

This also introduces a new -.slice root slice, that is the parent of
system.slice and friends. This enables easy admin configuration of
root-level cgrouo properties.

This replaces DeviceDeny= by DevicePolicy=, and implicitly adds in
/dev/null, /dev/zero and friends if DeviceAllow= is used (unless this is
turned off by DevicePolicy=).

1 files changed, 2 insertions, 0 deletions

diff --git a/src/core/slice.h b/src/core/slice.h
index 4320a6354..ad0c63902 100644
--- a/src/core/slice.h
+++ b/src/core/slice.h
@@ -36,6 +36,8 @@ struct Slice {
         Unit meta;
 
         SliceState state, deserialized_state;
+
+        CGroupContext cgroup_context;
 };
 
 extern const UnitVTable slice_vtable;