From 2285b528de460e2100f6852522963e6ac8ca18b4 Mon Sep 17 00:00:00 2001
From: David Anderson <dvander@google.com>
Date: Tue, 9 Nov 2021 18:26:39 -0800
Subject: [PATCH] init: Add a way to class_restart only enabled services.

class_restart accidentally restarts disabled services. Changing this
behavior is risky as it could break compatibility. Instead, add an
"--only-enabled" argument to class_restart to opt-in to the new
functionality. This syntax is backward compatible, as previously only a
1-argument form was accepted.

Bug: 190065372
Bug: 198105685
Test: add a class_restart action and a disabled service, make sure
      service is not restarted.
Change-Id: Idb08779de7ac7a21e23f8b8a3276bd5a66a43299
---
 init/README.md    |  5 +++--
 init/builtins.cpp | 28 ++++++++++++++++++++++++++--
 2 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/init/README.md b/init/README.md
index b10ca9e2b..ebab07359 100644
--- a/init/README.md
+++ b/init/README.md
@@ -496,8 +496,9 @@ Commands
   currently running, without disabling them. They can be restarted
   later using `class_start`.
 
-`class_restart <serviceclass>`
-> Restarts all services of the specified class.
+`class_restart [--only-enabled] <serviceclass>`
+> Restarts all services of the specified class. If `--only-enabled` is
+  specified, then disabled services are skipped.
 
 `copy <src> <dst>`
 > Copies a file. Similar to write, but useful for binary/large
diff --git a/init/builtins.cpp b/init/builtins.cpp
index 50a0cb2ca..98831e10d 100644
--- a/init/builtins.cpp
+++ b/init/builtins.cpp
@@ -190,7 +190,31 @@ static Result<void> do_class_restart(const BuiltinArguments& args) {
     // Do not restart a class if it has a property persist.dont_start_class.CLASS set to 1.
     if (android::base::GetBoolProperty("persist.init.dont_start_class." + args[1], false))
         return {};
-    ForEachServiceInClass(args[1], &Service::Restart);
+
+    std::string classname;
+
+    CHECK(args.size() == 2 || args.size() == 3);
+
+    bool only_enabled = false;
+    if (args.size() == 3) {
+        if (args[1] != "--only-enabled") {
+            return Error() << "Unexpected argument: " << args[1];
+        }
+        only_enabled = true;
+        classname = args[2];
+    } else if (args.size() == 2) {
+        classname = args[1];
+    }
+
+    for (const auto& service : ServiceList::GetInstance()) {
+        if (!service->classnames().count(classname)) {
+            continue;
+        }
+        if (only_enabled && !service->IsEnabled()) {
+            continue;
+        }
+        service->Restart();
+    }
     return {};
 }
 
@@ -1392,7 +1416,7 @@ const BuiltinFunctionMap& GetBuiltinFunctionMap() {
         {"chmod",                   {2,     2,    {true,   do_chmod}}},
         {"chown",                   {2,     3,    {true,   do_chown}}},
         {"class_reset",             {1,     1,    {false,  do_class_reset}}},
-        {"class_restart",           {1,     1,    {false,  do_class_restart}}},
+        {"class_restart",           {1,     2,    {false,  do_class_restart}}},
         {"class_start",             {1,     1,    {false,  do_class_start}}},
         {"class_stop",              {1,     1,    {false,  do_class_stop}}},
         {"copy",                    {2,     2,    {true,   do_copy}}},