From 1c755e22c8fac626aec289bff181191e6e87a237 Mon Sep 17 00:00:00 2001
From: Marco Ballesio <balejs@google.com>
Date: Tue, 2 Jun 2020 15:35:30 -0700
Subject: [PATCH] libprocessgroup: switch freezer to cgroup v2

remove cgroup v1 freezer entries from init.rc, add a new cgroup v2
controller and modify plists to properly interact with it.

Bug: 154548692
Test: manually verified the the cgroup v1 freezer controller isn't
created and a new controller for cgroup v2 is created under the correct
sysfs directory.

Change-Id: I1b811300ade486f88fdbd157255a7f37750cc54d
---
 libprocessgroup/profiles/cgroups.json       | 24 +++++++++++----------
 libprocessgroup/profiles/task_profiles.json | 14 ++++++------
 rootdir/init.rc                             | 10 ---------
 3 files changed, 20 insertions(+), 28 deletions(-)

diff --git a/libprocessgroup/profiles/cgroups.json b/libprocessgroup/profiles/cgroups.json
index 03419020c..451848711 100644
--- a/libprocessgroup/profiles/cgroups.json
+++ b/libprocessgroup/profiles/cgroups.json
@@ -39,19 +39,21 @@
       "Mode": "0755",
       "UID": "system",
       "GID": "system"
-    },
-    {
-      "Controller": "freezer",
-      "Path": "/dev/freezer",
-      "Mode": "0755",
-      "UID": "system",
-      "GID": "system"
     }
   ],
   "Cgroups2": {
-    "Path": "/dev/cg2_bpf",
-    "Mode": "0600",
-    "UID": "root",
-    "GID": "root"
+    "Path": "/sys/fs/cgroup",
+    "Mode": "0755",
+    "UID": "system",
+    "GID": "system",
+    "Controllers": [
+      {
+        "Controller": "freezer",
+        "Path": "freezer",
+        "Mode": "0755",
+        "UID": "system",
+        "GID": "system"
+      }
+    ]
   }
 }
diff --git a/libprocessgroup/profiles/task_profiles.json b/libprocessgroup/profiles/task_profiles.json
index bc6bc7c25..c4dbf8e55 100644
--- a/libprocessgroup/profiles/task_profiles.json
+++ b/libprocessgroup/profiles/task_profiles.json
@@ -53,7 +53,7 @@
     {
       "Name": "FreezerState",
       "Controller": "freezer",
-      "File": "frozen/freezer.state"
+      "File": "cgroup.freeze"
     }
   ],
 
@@ -79,7 +79,7 @@
           "Params":
           {
             "Controller": "freezer",
-            "Path": "frozen"
+            "Path": ""
           }
         }
       ]
@@ -92,7 +92,7 @@
           "Params":
           {
             "Controller": "freezer",
-            "Path": ""
+            "Path": "../"
           }
         }
       ]
@@ -538,27 +538,27 @@
       ]
     },
     {
-      "Name": "FreezerThawed",
+      "Name": "FreezerDisabled",
       "Actions": [
         {
           "Name": "SetAttribute",
           "Params":
           {
             "Name": "FreezerState",
-            "Value": "THAWED"
+            "Value": "0"
           }
         }
       ]
     },
     {
-      "Name": "FreezerFrozen",
+      "Name": "FreezerEnabled",
       "Actions": [
         {
           "Name": "SetAttribute",
           "Params":
           {
             "Name": "FreezerState",
-            "Value": "FROZEN"
+            "Value": "1"
           }
         }
       ]
diff --git a/rootdir/init.rc b/rootdir/init.rc
index 6fab57250..9079fa4b7 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -324,16 +324,6 @@ on init
     chmod 0664 /dev/cpuset/restricted/tasks
     chmod 0664 /dev/cpuset/tasks
 
-    # freezer cgroup entries
-    mkdir /dev/freezer/frozen
-    write /dev/freezer/frozen/freezer.state FROZEN
-    chown system system /dev/freezer/cgroup.procs
-    chown system system /dev/freezer/frozen
-    chown system system /dev/freezer/frozen/freezer.state
-    chown system system /dev/freezer/frozen/cgroup.procs
-
-    chmod 0664 /dev/freezer/frozen/freezer.state
-
     # make the PSI monitor accessible to others
     chown system system /proc/pressure/memory
     chmod 0664 /proc/pressure/memory