ChromeOS: Disable ARC when incompatible filesystem is detected.

chrome/browser/chromeos/arc/arc_util.cc

Index: chrome/browser/chromeos/arc/arc_util.cc
diff --git a/chrome/browser/chromeos/arc/arc_util.cc b/chrome/browser/chromeos/arc/arc_util.cc
index 3c40a7c2f950b82644f66845c0aada8f88eee9d2..8fdf110879347180b95d34cbf3e60ee5c3901318 100644
--- a/chrome/browser/chromeos/arc/arc_util.cc
+++ b/chrome/browser/chromeos/arc/arc_util.cc
@@ -4,7 +4,13 @@
 
 #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"
@@ -92,6 +98,12 @@ bool IsArcAllowedForProfile(const Profile* profile) {
     return false;
   }
 
+  if (!profile->GetPrefs()->GetBoolean(
+          prefs::kArcCompatibleFilesystemChosen)) {
+    VLOG(1) << "Users who postponed to migrate to dircrypto are not supported.";
+    return false;
+  }
+
   return true;
 }
 
@@ -141,4 +153,28 @@ bool AreArcAllOptInPreferencesManagedForProfile(const Profile* profile) {
              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