Migrate AuthFsHostTest to use MicrodroidBuilder

The biggest benefit is that microdroid is now a `TestDevice`. This
allows more symmetry in the test code.

Bug: 218751146
Test: atest AuthFsHostTest
Change-Id: Ib6063820ef8c2076669441952682647cff117a7e
diff --git a/authfs/tests/java/src/com/android/fs/AuthFsHostTest.java b/authfs/tests/java/src/com/android/fs/AuthFsHostTest.java
index 5d36f16..87af683 100644
--- a/authfs/tests/java/src/com/android/fs/AuthFsHostTest.java
+++ b/authfs/tests/java/src/com/android/fs/AuthFsHostTest.java
@@ -16,21 +16,28 @@
 
 package com.android.virt.fs;
 
+import static com.android.tradefed.device.TestDevice.MicrodroidBuilder;
 import static com.android.tradefed.testtype.DeviceJUnit4ClassRunner.TestLogData;
 
+import static com.google.common.truth.Truth.assertThat;
+
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 import static org.junit.Assume.assumeFalse;
 
 import android.platform.test.annotations.RootPermissionTest;
 import android.virt.test.CommandRunner;
 import android.virt.test.VirtualizationTestCaseBase;
 
+import com.android.compatibility.common.tradefed.build.CompatibilityBuildHelper;
 import com.android.compatibility.common.util.PollingCheck;
+import com.android.tradefed.build.IBuildInfo;
 import com.android.tradefed.device.DeviceNotAvailableException;
 import com.android.tradefed.device.ITestDevice;
+import com.android.tradefed.device.TestDevice;
 import com.android.tradefed.invoker.TestInformation;
 import com.android.tradefed.log.LogUtil.CLog;
 import com.android.tradefed.testtype.DeviceJUnit4ClassRunner;
@@ -47,7 +54,8 @@
 import org.junit.rules.TestName;
 import org.junit.runner.RunWith;
 
-import java.util.Optional;
+import java.io.File;
+import java.io.FileNotFoundException;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -62,6 +70,12 @@
     /** Output directory where the test can generate output on Android */
     private static final String TEST_OUTPUT_DIR = "/data/local/tmp/authfs/output_dir";
 
+    /** File name of the test APK */
+    private static final String TEST_APK_NAME = "MicrodroidTestApp.apk";
+
+    /** VM config entry path in the test APK */
+    private static final String VM_CONFIG_PATH_IN_APK = "assets/vm_config_extra_apk.json";
+
     /** Path to open_then_run on Android */
     private static final String OPEN_THEN_RUN_BIN = "/data/local/tmp/open_then_run";
 
@@ -75,9 +89,7 @@
     private static final String AUTHFS_BIN = "/system/bin/authfs";
 
     /** Idsig paths to be created for each APK in the "extra_apks" of vm_config_extra_apk.json. */
-    private static final String[] EXTRA_IDSIG_PATHS = new String[] {
-        TEST_DIR + "BuildManifest.apk.idsig",
-    };
+    private static final String EXTRA_IDSIG_PATH = TEST_DIR + "BuildManifest.apk.idsig";
 
     /** Build manifest path in the VM. 0 is the index of extra_apks in vm_config_extra_apk.json. */
     private static final String BUILD_MANIFEST_PATH = "/mnt/extra-apk/0/assets/build_manifest.pb";
@@ -99,7 +111,7 @@
     private static final int VMADDR_CID_HOST = 2;
 
     private static CommandRunner sAndroid;
-    private static String sCid;
+    private static CommandRunner sMicrodroid;
     private static boolean sAssumptionFailed;
 
     private ExecutorService mThreadPool = Executors.newCachedThreadPool();
@@ -127,30 +139,20 @@
             return;
         }
 
-        prepareVirtualizationTestSetup(androidDevice);
-
         // For each test case, boot and adb connect to a new Microdroid
         CLog.i("Starting the shared VM");
-        final String apkName = "MicrodroidTestApp.apk";
-        final String packageName = "com.android.microdroid.test";
-        final String configPath = "assets/vm_config_extra_apk.json"; // path inside the APK
-        sCid =
-                startMicrodroid(
-                        androidDevice,
-                        testInfo.getBuildInfo(),
-                        apkName,
-                        packageName,
-                        EXTRA_IDSIG_PATHS,
-                        configPath,
-                        /* debug */ true,
-                        /* use default memoryMib */ 0,
-                        Optional.empty(),
-                        Optional.empty());
-        adbConnectToMicrodroid(androidDevice, sCid);
+        ITestDevice microdroidDevice =
+                MicrodroidBuilder
+                        .fromFile(findTestApk(testInfo.getBuildInfo()), VM_CONFIG_PATH_IN_APK)
+                        .debugLevel("full")
+                        .addExtraIdsigPath(EXTRA_IDSIG_PATH)
+                        .build((TestDevice) androidDevice);
 
         // Root because authfs (started from shell in this test) currently require root to open
         // /dev/fuse and mount the FUSE.
-        rootMicrodroid();
+        assertThat(microdroidDevice.enableAdbRoot()).isTrue();
+
+        sMicrodroid = new CommandRunner(microdroidDevice);
     }
 
     @AfterClassWithInfo
@@ -158,13 +160,12 @@
             throws DeviceNotAvailableException {
         assertNotNull(sAndroid);
 
-        if (sCid != null) {
+        if (sMicrodroid != null) {
             CLog.i("Shutting down shared VM");
-            shutdownMicrodroid(sAndroid.getDevice(), sCid);
-            sCid = null;
+            ((TestDevice) testInfo.getDevice()).shutdownMicrodroid(sMicrodroid.getDevice());
+            sMicrodroid = null;
         }
 
-        cleanUpVirtualizationTestSetup(sAndroid.getDevice());
         sAndroid = null;
     }
 
@@ -177,8 +178,8 @@
     @After
     public void tearDown() throws Exception {
         sAndroid.tryRun("killall fd_server");
-        tryRunOnMicrodroid("killall authfs");
-        tryRunOnMicrodroid("umount " + MOUNT_DIR);
+        sMicrodroid.tryRun("killall authfs");
+        sMicrodroid.tryRun("umount " + MOUNT_DIR);
 
         // Even though we only run one VM for the whole class, and could have collect the VM log
         // after all tests are done, TestLogData doesn't seem to work at class level. Hence,
@@ -319,7 +320,7 @@
 
         // Verify
         // Force dropping the page cache, so that the next read can be validated.
-        runOnMicrodroid("echo 1 > /proc/sys/vm/drop_caches");
+        sMicrodroid.run("echo 1 > /proc/sys/vm/drop_caches");
         // A read will fail if the backing data has been tampered.
         assertFalse(checkReadAtFileOffsetOnMicrodroid(
                 destPath, /* offset */ 0, /* number */ 4096));
@@ -419,8 +420,8 @@
 
         // Action
         // Can create nested directories and can create a file in one.
-        runOnMicrodroid("mkdir " + authfsOutputDir + "/new_dir");
-        runOnMicrodroid("mkdir -p " + authfsOutputDir + "/we/need/to/go/deeper");
+        sMicrodroid.run("mkdir " + authfsOutputDir + "/new_dir");
+        sMicrodroid.run("mkdir -p " + authfsOutputDir + "/we/need/to/go/deeper");
         createFileWithOnesOnMicrodroid(authfsOutputDir + "/new_dir/file1", 10000);
         createFileWithOnesOnMicrodroid(authfsOutputDir + "/we/need/file2", 10000);
 
@@ -452,7 +453,7 @@
         runAuthFsOnMicrodroid("--remote-new-rw-dir 3 --cid " + VMADDR_CID_HOST);
 
         // Action & Verify
-        runOnMicrodroid("echo -n foo > " + authfsOutputDir + "/file");
+        sMicrodroid.run("echo -n foo > " + authfsOutputDir + "/file");
         assertEquals(getFileSizeInBytesOnMicrodroid(authfsOutputDir + "/file"), 3);
         // Can override a file and write normally.
         createFileWithOnesOnMicrodroid(authfsOutputDir + "/file", 10000);
@@ -472,13 +473,13 @@
         runFdServerOnAndroid("--open-dir 3:" + androidOutputDir, "--rw-dirs 3");
         runAuthFsOnMicrodroid("--remote-new-rw-dir 3 --cid " + VMADDR_CID_HOST);
 
-        runOnMicrodroid("echo -n foo > " + authfsOutputDir + "/file");
-        runOnMicrodroid("test -f " + authfsOutputDir + "/file");
+        sMicrodroid.run("echo -n foo > " + authfsOutputDir + "/file");
+        sMicrodroid.run("test -f " + authfsOutputDir + "/file");
         sAndroid.run("test -f " + androidOutputDir + "/file");
 
         // Action & Verify
-        runOnMicrodroid("rm " + authfsOutputDir + "/file");
-        runOnMicrodroid("test ! -f " + authfsOutputDir + "/file");
+        sMicrodroid.run("rm " + authfsOutputDir + "/file");
+        sMicrodroid.run("test ! -f " + authfsOutputDir + "/file");
         sAndroid.run("test ! -f " + androidOutputDir + "/file");
     }
 
@@ -491,20 +492,20 @@
         runFdServerOnAndroid("--open-dir 3:" + androidOutputDir, "--rw-dirs 3");
         runAuthFsOnMicrodroid("--remote-new-rw-dir 3 --cid " + VMADDR_CID_HOST);
 
-        runOnMicrodroid("mkdir -p " + authfsOutputDir + "/dir/dir2");
-        runOnMicrodroid("echo -n foo > " + authfsOutputDir + "/dir/file");
+        sMicrodroid.run("mkdir -p " + authfsOutputDir + "/dir/dir2");
+        sMicrodroid.run("echo -n foo > " + authfsOutputDir + "/dir/file");
         sAndroid.run("test -d " + androidOutputDir + "/dir/dir2");
 
         // Action & Verify
-        runOnMicrodroid("rmdir " + authfsOutputDir + "/dir/dir2");
-        runOnMicrodroid("test ! -d " + authfsOutputDir + "/dir/dir2");
+        sMicrodroid.run("rmdir " + authfsOutputDir + "/dir/dir2");
+        sMicrodroid.run("test ! -d " + authfsOutputDir + "/dir/dir2");
         sAndroid.run("test ! -d " + androidOutputDir + "/dir/dir2");
         // Can only delete a directory if empty
         assertFailedOnMicrodroid("rmdir " + authfsOutputDir + "/dir");
-        runOnMicrodroid("test -d " + authfsOutputDir + "/dir");  // still there
-        runOnMicrodroid("rm " + authfsOutputDir + "/dir/file");
-        runOnMicrodroid("rmdir " + authfsOutputDir + "/dir");
-        runOnMicrodroid("test ! -d " + authfsOutputDir + "/dir");
+        sMicrodroid.run("test -d " + authfsOutputDir + "/dir");  // still there
+        sMicrodroid.run("rm " + authfsOutputDir + "/dir/file");
+        sMicrodroid.run("rmdir " + authfsOutputDir + "/dir");
+        sMicrodroid.run("test ! -d " + authfsOutputDir + "/dir");
         sAndroid.run("test ! -d " + androidOutputDir + "/dir");
     }
 
@@ -517,10 +518,10 @@
         runFdServerOnAndroid("--open-dir 3:" + androidOutputDir, "--rw-dirs 3");
         runAuthFsOnMicrodroid("--remote-new-rw-dir 3 --cid " + VMADDR_CID_HOST);
 
-        runOnMicrodroid("touch " + authfsOutputDir + "/some_file");
-        runOnMicrodroid("mkdir " + authfsOutputDir + "/some_dir");
-        runOnMicrodroid("touch " + authfsOutputDir + "/some_dir/file");
-        runOnMicrodroid("mkdir " + authfsOutputDir + "/some_dir/dir");
+        sMicrodroid.run("touch " + authfsOutputDir + "/some_file");
+        sMicrodroid.run("mkdir " + authfsOutputDir + "/some_dir");
+        sMicrodroid.run("touch " + authfsOutputDir + "/some_dir/file");
+        sMicrodroid.run("mkdir " + authfsOutputDir + "/some_dir/dir");
 
         // Action & Verify
         // Cannot create directory if an entry with the same name already exists.
@@ -542,12 +543,12 @@
         // Create a file with some data. Test the existence.
         String outputPath = authfsOutputDir + "/out";
         String androidOutputPath = androidOutputDir + "/out";
-        runOnMicrodroid("echo -n 123 > " + outputPath);
-        runOnMicrodroid("test -f " + outputPath);
+        sMicrodroid.run("echo -n 123 > " + outputPath);
+        sMicrodroid.run("test -f " + outputPath);
         sAndroid.run("test -f " + androidOutputPath);
 
         // Action
-        String output = runOnMicrodroid(
+        String output = sMicrodroid.run(
                 // Open the file for append and read
                 "exec 4>>" + outputPath + " 5<" + outputPath + "; "
                 // Delete the file from the directory
@@ -560,7 +561,7 @@
         // Verify
         // Output contains all written data, while the files are deleted.
         assertEquals("123456", output);
-        runOnMicrodroid("test ! -f " + outputPath);
+        sMicrodroid.run("test ! -f " + outputPath);
         sAndroid.run("test ! -f " + androidOutputDir + "/out");
     }
 
@@ -590,7 +591,7 @@
                 + VMADDR_CID_HOST);
 
         // Verify
-        runOnMicrodroid("test -f " + authfsInputDir + "/system/framework/services.jar");
+        sMicrodroid.run("test -f " + authfsInputDir + "/system/framework/services.jar");
         assertFailedOnMicrodroid("test -f " + authfsInputDir + "/system/bin/sh");
     }
 
@@ -602,14 +603,14 @@
 
         // Action
         String authfsOutputDir = MOUNT_DIR + "/3";
-        runOnMicrodroid("mkdir -p " + authfsOutputDir + "/dir/dir2/dir3");
-        runOnMicrodroid("touch " + authfsOutputDir + "/dir/dir2/dir3/file1");
-        runOnMicrodroid("touch " + authfsOutputDir + "/dir/dir2/dir3/file2");
-        runOnMicrodroid("touch " + authfsOutputDir + "/dir/dir2/dir3/file3");
-        runOnMicrodroid("touch " + authfsOutputDir + "/file");
+        sMicrodroid.run("mkdir -p " + authfsOutputDir + "/dir/dir2/dir3");
+        sMicrodroid.run("touch " + authfsOutputDir + "/dir/dir2/dir3/file1");
+        sMicrodroid.run("touch " + authfsOutputDir + "/dir/dir2/dir3/file2");
+        sMicrodroid.run("touch " + authfsOutputDir + "/dir/dir2/dir3/file3");
+        sMicrodroid.run("touch " + authfsOutputDir + "/file");
 
         // Verify
-        String[] actual = runOnMicrodroid("cd " + authfsOutputDir + "; find |sort").split("\n");
+        String[] actual = sMicrodroid.run("cd " + authfsOutputDir + "; find |sort").split("\n");
         String[] expected = new String[] {
                 ".",
                 "./dir",
@@ -622,14 +623,14 @@
         assertEquals(expected, actual);
 
         // Add more entries.
-        runOnMicrodroid("mkdir -p " + authfsOutputDir + "/dir2");
-        runOnMicrodroid("touch " + authfsOutputDir + "/file2");
+        sMicrodroid.run("mkdir -p " + authfsOutputDir + "/dir2");
+        sMicrodroid.run("touch " + authfsOutputDir + "/file2");
         // Check new entries. Also check that the types are correct.
-        actual = runOnMicrodroid(
+        actual = sMicrodroid.run(
                 "cd " + authfsOutputDir + "; find -maxdepth 1 -type f |sort").split("\n");
         expected = new String[] {"./file", "./file2"};
         assertEquals(expected, actual);
-        actual = runOnMicrodroid(
+        actual = sMicrodroid.run(
                 "cd " + authfsOutputDir + "; find -maxdepth 1 -type d |sort").split("\n");
         expected = new String[] {".", "./dir", "./dir2"};
         assertEquals(expected, actual);
@@ -643,7 +644,7 @@
 
         // Action & Verify
         // Change mode
-        runOnMicrodroid("chmod 321 " + MOUNT_DIR + "/3");
+        sMicrodroid.run("chmod 321 " + MOUNT_DIR + "/3");
         expectFileMode("--wx-w---x", MOUNT_DIR + "/3", TEST_OUTPUT_DIR + "/file");
         // Can't set the disallowed bits
         assertFailedOnMicrodroid("chmod +s " + MOUNT_DIR + "/3");
@@ -659,14 +660,14 @@
         // Action & Verify
         String authfsOutputDir = MOUNT_DIR + "/3";
         // Create with umask
-        runOnMicrodroid("umask 000; mkdir " + authfsOutputDir + "/dir");
-        runOnMicrodroid("umask 022; mkdir " + authfsOutputDir + "/dir/dir2");
+        sMicrodroid.run("umask 000; mkdir " + authfsOutputDir + "/dir");
+        sMicrodroid.run("umask 022; mkdir " + authfsOutputDir + "/dir/dir2");
         expectFileMode("drwxrwxrwx", authfsOutputDir + "/dir", TEST_OUTPUT_DIR + "/dir");
         expectFileMode("drwxr-xr-x", authfsOutputDir + "/dir/dir2", TEST_OUTPUT_DIR + "/dir/dir2");
         // Change mode
-        runOnMicrodroid("chmod -w " + authfsOutputDir + "/dir/dir2");
+        sMicrodroid.run("chmod -w " + authfsOutputDir + "/dir/dir2");
         expectFileMode("dr-xr-xr-x", authfsOutputDir + "/dir/dir2", TEST_OUTPUT_DIR + "/dir/dir2");
-        runOnMicrodroid("chmod 321 " + authfsOutputDir + "/dir");
+        sMicrodroid.run("chmod 321 " + authfsOutputDir + "/dir");
         expectFileMode("d-wx-w---x", authfsOutputDir + "/dir", TEST_OUTPUT_DIR + "/dir");
         // Can't set the disallowed bits
         assertFailedOnMicrodroid("chmod +s " + authfsOutputDir + "/dir/dir2");
@@ -682,14 +683,14 @@
         // Action & Verify
         String authfsOutputDir = MOUNT_DIR + "/3";
         // Create with umask
-        runOnMicrodroid("umask 000; echo -n foo > " + authfsOutputDir + "/file");
-        runOnMicrodroid("umask 022; echo -n foo > " + authfsOutputDir + "/file2");
+        sMicrodroid.run("umask 000; echo -n foo > " + authfsOutputDir + "/file");
+        sMicrodroid.run("umask 022; echo -n foo > " + authfsOutputDir + "/file2");
         expectFileMode("-rw-rw-rw-", authfsOutputDir + "/file", TEST_OUTPUT_DIR + "/file");
         expectFileMode("-rw-r--r--", authfsOutputDir + "/file2", TEST_OUTPUT_DIR + "/file2");
         // Change mode
-        runOnMicrodroid("chmod -w " + authfsOutputDir + "/file");
+        sMicrodroid.run("chmod -w " + authfsOutputDir + "/file");
         expectFileMode("-r--r--r--", authfsOutputDir + "/file", TEST_OUTPUT_DIR + "/file");
-        runOnMicrodroid("chmod 321 " + authfsOutputDir + "/file2");
+        sMicrodroid.run("chmod 321 " + authfsOutputDir + "/file2");
         expectFileMode("--wx-w---x", authfsOutputDir + "/file2", TEST_OUTPUT_DIR + "/file2");
         // Can't set the disallowed bits
         assertFailedOnMicrodroid("chmod +s " + authfsOutputDir + "/file");
@@ -705,7 +706,16 @@
         // Verify
         // Magic matches. Has only 2 inodes (root and "/3").
         assertEquals(
-                FUSE_SUPER_MAGIC_HEX + " 2", runOnMicrodroid("stat -f -c '%t %c' " + MOUNT_DIR));
+                FUSE_SUPER_MAGIC_HEX + " 2", sMicrodroid.run("stat -f -c '%t %c' " + MOUNT_DIR));
+    }
+
+    private static File findTestApk(IBuildInfo buildInfo) {
+        try {
+            return (new CompatibilityBuildHelper(buildInfo)).getTestFile(TEST_APK_NAME);
+        } catch (FileNotFoundException e) {
+            fail("Missing test file: " + TEST_APK_NAME);
+            return null;
+        }
     }
 
     private void expectBackingFileConsistency(
@@ -719,8 +729,8 @@
                 "Inconsistent file hash on the backend storage", hashOnAuthFs, hashOfBackingFile);
     }
 
-    private String computeFileHashOnMicrodroid(String path) {
-        String result = runOnMicrodroid("sha256sum " + path);
+    private String computeFileHashOnMicrodroid(String path) throws DeviceNotAvailableException {
+        String result = sMicrodroid.run("sha256sum " + path);
         String[] tokens = result.split("\\s");
         if (tokens.length > 0) {
             return tokens[0];
@@ -735,7 +745,7 @@
         // TODO(b/182576497): cp returns error because close(2) returns ENOSYS in the current authfs
         // implementation. We should probably fix that since programs can expect close(2) return 0.
         String cmd = "cat " + src + " > " + dest;
-        return tryRunOnMicrodroid(cmd) != null;
+        return sMicrodroid.tryRun(cmd) != null;
     }
 
     private String computeFileHashOnAndroid(String path) throws DeviceNotAvailableException {
@@ -751,38 +761,42 @@
 
     private void expectFileMode(String expected, String microdroidPath, String androidPath)
             throws DeviceNotAvailableException {
-        String actual = runOnMicrodroid("stat -c '%A' " + microdroidPath);
+        String actual = sMicrodroid.run("stat -c '%A' " + microdroidPath);
         assertEquals("Inconsistent mode for " + microdroidPath, expected, actual);
 
         actual = sAndroid.run("stat -c '%A' " + androidPath);
         assertEquals("Inconsistent mode for " + androidPath + " (android)", expected, actual);
     }
 
-    private boolean resizeFileOnMicrodroid(String path, long size) {
-        CommandResult result = runOnMicrodroidForResult("truncate -c -s " + size + " " + path);
+    private boolean resizeFileOnMicrodroid(String path, long size)
+            throws DeviceNotAvailableException {
+        CommandResult result = sMicrodroid.runForResult("truncate -c -s " + size + " " + path);
         return result.getStatus() == CommandStatus.SUCCESS;
     }
 
-    private long getFileSizeInBytesOnMicrodroid(String path) {
-        return Long.parseLong(runOnMicrodroid("stat -c '%s' " + path));
+    private long getFileSizeInBytesOnMicrodroid(String path) throws DeviceNotAvailableException {
+        return Long.parseLong(sMicrodroid.run("stat -c '%s' " + path));
     }
 
-    private void createFileWithOnesOnMicrodroid(String filePath, long numberOfOnes) {
-        runOnMicrodroid(
+    private void createFileWithOnesOnMicrodroid(String filePath, long numberOfOnes)
+            throws DeviceNotAvailableException {
+        sMicrodroid.run(
                 "yes $'\\x01' | tr -d '\\n' | dd bs=1 count=" + numberOfOnes + " of=" + filePath);
     }
 
-    private boolean checkReadAtFileOffsetOnMicrodroid(String filePath, long offset, long size) {
+    private boolean checkReadAtFileOffsetOnMicrodroid(String filePath, long offset, long size)
+            throws DeviceNotAvailableException {
         String cmd = "dd if=" + filePath + " of=/dev/null bs=1 count=" + size;
         if (offset > 0) {
             cmd += " skip=" + offset;
         }
-        CommandResult result = runOnMicrodroidForResult(cmd);
+        CommandResult result = sMicrodroid.runForResult(cmd);
         return result.getStatus() == CommandStatus.SUCCESS;
     }
 
     private boolean writeZerosAtFileOffsetOnMicrodroid(
-            String filePath, long offset, long numberOfZeros, boolean writeThrough) {
+            String filePath, long offset, long numberOfZeros, boolean writeThrough)
+            throws DeviceNotAvailableException {
         String cmd = "dd if=/dev/zero of=" + filePath + " bs=1 count=" + numberOfZeros
                 + " conv=notrunc";
         if (offset > 0) {
@@ -791,7 +805,7 @@
         if (writeThrough) {
             cmd += " direct";
         }
-        CommandResult result = runOnMicrodroidForResult(cmd);
+        CommandResult result = sMicrodroid.runForResult(cmd);
         return result.getStatus() == CommandStatus.SUCCESS;
     }
 
@@ -810,9 +824,14 @@
                     // authfs may fail to start if fd_server is not yet listening on the vsock
                     // ("Error: Invalid raw AIBinder"). Just restart if that happens.
                     while (starting.get()) {
-                        CLog.i("Starting authfs");
-                        CommandResult result = runOnMicrodroidForResult(cmd);
-                        CLog.w("authfs has stopped: " + result);
+                        try {
+                            CLog.i("Starting authfs");
+                            CommandResult result = sMicrodroid.runForResult(cmd);
+                            CLog.w("authfs has stopped: " + result);
+                        } catch (DeviceNotAvailableException e) {
+                            CLog.e("Error running authfs", e);
+                            throw new RuntimeException(e);
+                        }
                     }
                 });
         try {
@@ -855,8 +874,8 @@
                 });
     }
 
-    private boolean isMicrodroidDirectoryOnFuse(String path) {
-        String fs_type = tryRunOnMicrodroid("stat -f -c '%t' " + path);
+    private boolean isMicrodroidDirectoryOnFuse(String path) throws DeviceNotAvailableException {
+        String fs_type = sMicrodroid.tryRun("stat -f -c '%t' " + path);
         return FUSE_SUPER_MAGIC_HEX.equals(fs_type);
     }
 }