Merge "Fix Deadlock Issue On AppFuseBridge" (276ae017) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/storage/AppFuseBridge.java

+12 −0

Original line number	Diff line number	Diff line
		@@ -56,6 +56,15 @@ public class AppFuseBridge implements Runnable {

		public ParcelFileDescriptor addBridge(MountScope mountScope)
		throws FuseUnavailableMountException, NativeDaemonConnectorException {
		/*
		** Dead Lock between Java lock (AppFuseBridge.java) and Native lock (FuseBridgeLoop.cc)
		**
		** (Thread A) Got Java lock (addBrdige) -> Try to get Native lock (native_add_brdige)
		** (Thread B) Got Native lock (FuseBrdigeLoop.start) -> Try to get Java lock (onClosed)
		**
		** Guarantee the lock order (native lock -> java lock) when adding Bridge.
		*/
		native_lock();
		try {
		synchronized (this) {
		Preconditions.checkArgument(mScopes.indexOfKey(mountScope.mountId) < 0);
		@@ -73,6 +82,7 @@ public class AppFuseBridge implements Runnable {
		return result;
		}
		} finally {
		native_unlock();
		IoUtils.closeQuietly(mountScope);
		}
		}
		@@ -159,4 +169,6 @@ public class AppFuseBridge implements Runnable {
		private native void native_delete(long loop);
		private native void native_start_loop(long loop);
		private native int native_add_bridge(long loop, int mountId, int deviceId);
		private native void native_lock();
		private native void native_unlock();
		}

+18 −0

Original line number	Diff line number	Diff line
		@@ -123,6 +123,14 @@ jint com_android_server_storage_AppFuseBridge_add_bridge(
		return proxyFd[1].release();
		}

		void com_android_server_storage_AppFuseBridge_lock(JNIEnv* env, jobject self) {
		fuse::FuseBridgeLoop::Lock();
		}

		void com_android_server_storage_AppFuseBridge_unlock(JNIEnv* env, jobject self) {
		fuse::FuseBridgeLoop::Unlock();
		}

		const JNINativeMethod methods[] = {
		{
		"native_new",
		@@ -143,6 +151,16 @@ const JNINativeMethod methods[] = {
		"native_add_bridge",
		"(JII)I",
		reinterpret_cast<void*>(com_android_server_storage_AppFuseBridge_add_bridge)
		},
		{
		"native_lock",
		"()V",
		reinterpret_cast<void*>(com_android_server_storage_AppFuseBridge_lock)
		},
		{
		"native_unlock",
		"()V",
		reinterpret_cast<void*>(com_android_server_storage_AppFuseBridge_unlock)
		}
		};