[Android] remount file system as writeable when failing to push files to external storage

build/android/provision_devices.py

 #!/usr/bin/env python
 #
 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Provisions Android devices with settings required for bots.
 
 Usage:
   ./provision_devices.py [-d <device serial number>]
 """
 
 import argparse
 import datetime
 import json
 import logging
 import os
 import posixpath
 import re
 import subprocess
 import sys
 import time
 
 from devil.android import battery_utils
 from devil.android import device_blacklist
 from devil.android import device_errors
+from devil.android import device_temp_file
 from devil.android import device_utils
 from devil.android.sdk import version_codes
 from devil.utils import run_tests_helper
 from devil.utils import timeout_retry
 from pylib import constants
 from pylib import device_settings
 
 _SYSTEM_WEBVIEW_PATHS = ['/system/app/webview', '/system/app/WebViewGoogle']
 _CHROME_PACKAGE_REGEX = re.compile('.*chrom.*')
 _TOMBSTONE_REGEX = re.compile('tombstone.*')
@@ skipping 55 matching lines @@
       device.WaitUntilFullyBooted(timeout=reboot_timeout, retries=0)
     except device_errors.CommandTimeoutError:
       logging.error('Device did not finish booting. Will try to reboot.')
       device.Reboot(timeout=reboot_timeout)
     phase_func(device, options)
     if reboot:
       device.Reboot(False, retries=0)
       device.adb.WaitForDevice()
 
   try:
+    CheckExternalStorage(device)
     if should_run_phase(_PHASES.WIPE):
       if options.chrome_specific_wipe:
         run_phase(WipeChromeData)
       else:
         run_phase(WipeDevice)
 
     if should_run_phase(_PHASES.PROPERTIES):
       run_phase(SetProperties)
 
     if should_run_phase(_PHASES.FINISH):
       run_phase(FinishProvisioning, reboot=False)
 
     if options.chrome_specific_wipe:
       package = "com.google.android.gms"
       version_name = device.GetApplicationVersion(package)
       logging.info("Version name for %s is %s", package, version_name)
 
   except device_errors.CommandTimeoutError:
     logging.exception('Timed out waiting for device %s. Adding to blacklist.',
                       str(device))
     blacklist.Extend([str(device)])
 
   except device_errors.CommandFailedError:
     logging.exception('Failed to provision device %s. Adding to blacklist.',
                       str(device))
     blacklist.Extend([str(device)])
 
+def CheckExternalStorage(device):
+  """Checks that storage is writable and if not makes it writable.
+
+  Arguments:
+    device: The device to check.
+  """
+  try:
+    with device_temp_file.DeviceTempFile(
+        device.adb, suffix='.sh', dir=device.GetExternalStoragePath()):
+      pass
+  except device_errors.CommandFailedError:
+    logging.info('External storage not writable. Remounting / as RW')
+    device.RunShellCommand(['mount', '-o', 'remount,rw', '/'],
+                           check_return=True, as_root=True)
+    with device_temp_file.DeviceTempFile(
+        device.adb, suffix='.sh', dir=device.GetExternalStoragePath()):
+      pass
 
 def WipeChromeData(device, options):
   """Wipes chrome specific data from device
 
   (1) uninstall any app whose name matches *chrom*, except
       com.android.chrome, which is the chrome stable package. Doing so also
       removes the corresponding dirs under /data/data/ and /data/app/
   (2) remove any dir under /data/app-lib/ whose name matches *chrom*
   (3) remove any files under /data/tombstones/ whose name matches "tombstone*"
   (4) remove /data/local.prop if there is any
@@ skipping 246 matching lines @@
 
 
 def _LaunchHostHeartbeat():
   # Kill if existing host_heartbeat
   KillHostHeartbeat()
   # Launch a new host_heartbeat
   logging.info('Spawning host heartbeat...')
   subprocess.Popen([os.path.join(constants.DIR_SOURCE_ROOT,
                                  'build/android/host_heartbeat.py')])
 
-
 def KillHostHeartbeat():
   ps = subprocess.Popen(['ps', 'aux'], stdout=subprocess.PIPE)
   stdout, _ = ps.communicate()
   matches = re.findall('\\n.*host_heartbeat.*', stdout)
   for match in matches:
     logging.info('An instance of host heart beart running... will kill')
     pid = re.findall(r'(\S+)', match)[1]
     subprocess.call(['kill', str(pid)])
 
-
 def main():
   # Recommended options on perf bots:
   # --disable-network
   #     TODO(tonyg): We eventually want network on. However, currently radios
   #     can cause perfbots to drain faster than they charge.
   # --min-battery-level 95
   #     Some perf bots run benchmarks with USB charging disabled which leads
   #     to gradual draining of the battery. We must wait for a full charge
   #     before starting a run in order to keep the devices online.
 
@@ skipping 47 matching lines @@
   args = parser.parse_args()
   constants.SetBuildType(args.target)
 
   run_tests_helper.SetLogLevel(args.verbose)
 
   return ProvisionDevices(args)
 
 
 if __name__ == '__main__':
   sys.exit(main())