Changes of root storage space unmounting time on Zygote Process
Zygote process forks every child process for launch the SystemServer and other
applications. When child process is forked, unmount storage inherited
from Zygote process is executed before it gains its own root storage
space.
If Zygote have no storage spaces, unmount operations not needed to
get relevant permission storage space.
Thus unmount is executed only once shortly before the SystemServer is forked.
And the child processes do not unmount its inherited root storage space.
Change-Id: I311ca7ea2c93085f42579f8cf8bdc7ef1d570a04
diff --git a/core/jni/com_android_internal_os_Zygote.cpp b/core/jni/com_android_internal_os_Zygote.cpp
index 612f4df..3f4b2a6 100644
--- a/core/jni/com_android_internal_os_Zygote.cpp
+++ b/core/jni/com_android_internal_os_Zygote.cpp
@@ -302,9 +302,6 @@
return false;
}
- // Unmount storage provided by root namespace and mount requested view
- UnmountTree("/storage");
-
String8 storageSource;
if (mount_mode == MOUNT_EXTERNAL_DEFAULT) {
storageSource = "/mnt/runtime/default";
@@ -667,12 +664,24 @@
return pid;
}
+static void com_android_internal_os_Zygote_nativeUnmountStorageOnInit(JNIEnv* env, jclass) {
+ // Zygote process unmount root storage space initially before every child processes are forked.
+ // Every forked child processes (include SystemServer) only mount their own root storage space
+ // And no need unmount storage operation in MountEmulatedStorage method.
+ // Zygote process does not utilize root storage spaces and unshared its mount namespace from the ART.
+
+ UnmountTree("/storage");
+ return;
+}
+
static const JNINativeMethod gMethods[] = {
{ "nativeForkAndSpecialize",
"(II[II[[IILjava/lang/String;Ljava/lang/String;[ILjava/lang/String;Ljava/lang/String;)I",
(void *) com_android_internal_os_Zygote_nativeForkAndSpecialize },
{ "nativeForkSystemServer", "(II[II[[IJJ)I",
- (void *) com_android_internal_os_Zygote_nativeForkSystemServer }
+ (void *) com_android_internal_os_Zygote_nativeForkSystemServer },
+ { "nativeUnmountStorageOnInit", "()V",
+ (void *) com_android_internal_os_Zygote_nativeUnmountStorageOnInit }
};
int register_com_android_internal_os_Zygote(JNIEnv* env) {