ChromeOS: Disable ARC when incompatible filesystem is detected.

chrome/browser/chromeos/arc/arc_util.cc

 // Copyright 2017 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.
 
 #include "chrome/browser/chromeos/arc/arc_util.h"
 
+#include <linux/magic.h>
+#include <sys/statfs.h>
+
+#include "base/files/file_path.h"
+#include "base/files/file_util.h"
 #include "base/logging.h"
+#include "base/strings/string_split.h"
 #include "chrome/browser/chromeos/arc/arc_session_manager.h"
 #include "chrome/browser/chromeos/login/user_flow.h"
 #include "chrome/browser/chromeos/login/users/chrome_user_manager.h"
 #include "chrome/browser/chromeos/profiles/profile_helper.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/pref_names.h"
 #include "components/arc/arc_util.h"
 #include "components/prefs/pref_service.h"
 #include "components/user_manager/user.h"
 #include "components/user_manager/user_manager.h"
@@ skipping 67 matching lines @@
     return false;
   }
 
   // Do not allow for Ephemeral data user. cf) b/26402681
   if (user_manager::UserManager::Get()
           ->IsCurrentUserCryptohomeDataEphemeral()) {
     VLOG(1) << "Users with ephemeral data are not supported in ARC.";
     return false;
   }
 
+  if (!profile->GetPrefs()->GetBoolean(
+          prefs::kArcCompatibleFilesystemChosen)) {
+    VLOG(1) << "Users who postponed to migrate to dircrypto are not supported.";
+    return false;
+  }
+
   return true;
 }
 
 void DisallowArcForTesting() {
   g_disallow_for_testing = true;
 }
 
 bool IsArcPlayStoreEnabledForProfile(const Profile* profile) {
   return IsArcAllowedForProfile(profile) &&
          profile->GetPrefs()->GetBoolean(prefs::kArcEnabled);
@@ skipping 29 matching lines @@
   profile->GetPrefs()->SetBoolean(prefs::kArcEnabled, enabled);
 }
 
 bool AreArcAllOptInPreferencesManagedForProfile(const Profile* profile) {
   return profile->GetPrefs()->IsManagedPreference(
              prefs::kArcBackupRestoreEnabled) &&
          profile->GetPrefs()->IsManagedPreference(
              prefs::kArcLocationServiceEnabled);
 }
 
+bool IsArcCompatibleFilesystem(const base::FilePath& path) {
+  // If it can be verified it is not on ecryptfs, then it is ok.
+  struct statfs statfs_buf;
+  if (statfs(path.value().c_str(), &statfs_buf) < 0)
+    return false;
+  if (statfs_buf.f_type != ECRYPTFS_SUPER_MAGIC)
+    return true;
+
+  // Otherwise, it is ok if and only if we are running Android M.
+  std::string lsb_release;
+  if (!base::ReadFileToString(

[xiyuan, 2017/04/03 16:20:49]

Think lsb release info is loaded and parsed early on browser start up. Can you
replace it with base::SysInfo::GetLsbReleaseValue() ?

[kinaba, 2017/04/04 04:13:56]

Thanks! That's very nice to know.
Replaced the whole check to use GetLsbReleaseValue() and
inlined to IsArcAllowedForProfile() (which resolved one corner case,
see my CL description.)

+          base::FilePath(FILE_PATH_LITERAL("/etc/lsb-release")),
+          &lsb_release)) {
+    return false;
+  }
+  base::StringPairs pairs;
+  base::SplitStringIntoKeyValuePairs(lsb_release, '=', '\n', &pairs);
+  for (const auto& pair : pairs) {
+    if (pair.first == "CHROMEOS_ARC_ANDROID_SDK_VERSION")
+      return pair.second == "23";
+  }
+  return false;
+}
+
 }  // namespace arc