From 352ae2d225cd78248cdb0c5cbf829a49ed227e75 Mon Sep 17 00:00:00 2001
From: Nikita Ioffe <ioffe@google.com>
Date: Fri, 28 Feb 2020 11:37:22 +0000
Subject: [PATCH] Stop & Resume property service when switching to bootstrap
 namespace

Test: atest CtsUserspaceRebootHostSideTestCases
Bug: 148236233
Bug: 149745936
Merged-In: I9d30b75f4b4177175ce086c3b6a7c0bba9a17396
Change-Id: I9d30b75f4b4177175ce086c3b6a7c0bba9a17396
(cherry picked from commit 6963f81a2b9d07d266b768aa03cfd212bf64b107)
---
 init/mount_namespace.cpp | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/init/mount_namespace.cpp b/init/mount_namespace.cpp
index aa368492d..21750754e 100644
--- a/init/mount_namespace.cpp
+++ b/init/mount_namespace.cpp
@@ -323,10 +323,20 @@ bool SwitchToBootstrapMountNamespaceIfNeeded() {
     }
     if (bootstrap_ns_id != GetMountNamespaceId() && bootstrap_ns_fd.get() != -1 &&
         IsApexUpdatable()) {
+        // The property service thread and its descendent threads must be in the correct mount
+        // namespace to call Service::Start(), however setns() only operates on a single thread and
+        // fails when secondary threads attempt to join the same mount namespace.  Therefore, we
+        // must join the property service thread and its descendents before the setns() call.  Those
+        // threads are then started again after the setns() call, and they'll be in the proper
+        // namespace.
+        PausePropertyService();
+
         if (setns(bootstrap_ns_fd.get(), CLONE_NEWNS) == -1) {
             PLOG(ERROR) << "Failed to switch to bootstrap mount namespace.";
             return false;
         }
+
+        ResumePropertyService();
     }
     return true;
 }