arc: Abort booting ARC if the device is critically low on disk space.

chromeos/dbus/cryptohome_client.cc

 // Copyright (c) 2012 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 "chromeos/dbus/cryptohome_client.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include "base/bind.h"
@@ skipping 150 matching lines @@
     FillIdentificationProtobuf(account_id, &id);
 
     dbus::MessageWriter writer(&method_call);
     writer.AppendProtoAsArrayOfBytes(id);
     proxy_->CallMethod(&method_call, kTpmDBusTimeoutMs,
                        base::Bind(&CryptohomeClientImpl::OnBaseReplyMethod,
                                   weak_ptr_factory_.GetWeakPtr(), callback));
   }
 
   // CryptohomeClient override.
+  void GetFreeDiskSpace(const GetFreeDiskSpaceCallback& callback) override {
+    dbus::MethodCall method_call(cryptohome::kCryptohomeInterface,
+                                 cryptohome::kCryptohomeGetFreeDiskSpace);
+    proxy_->CallMethod(&method_call, kTpmDBusTimeoutMs,
+                       base::Bind(&CryptohomeClientImpl::OnGetFreeDiskSpace,
+                                  weak_ptr_factory_.GetWeakPtr(), callback));
+  }
+
+  // CryptohomeClient override.
   void GetSystemSalt(const GetSystemSaltCallback& callback) override {
     dbus::MethodCall method_call(cryptohome::kCryptohomeInterface,
                                  cryptohome::kCryptohomeGetSystemSalt);
     proxy_->CallMethod(&method_call, kTpmDBusTimeoutMs ,
                        base::Bind(&CryptohomeClientImpl::OnGetSystemSalt,
                                   weak_ptr_factory_.GetWeakPtr(),
                                   callback));
   }
 
   // CryptohomeClient override,
@@ skipping 785 matching lines @@
     }
     dbus::MessageReader reader(response);
     int async_id = 0;
     if (!reader.PopInt32(&async_id)) {
       LOG(ERROR) << "Invalid response: " << response->ToString();
       return;
     }
     callback.Run(async_id);
   }
 
+  // Handles the result of GetFreeDiskSpace().
+  void OnGetFreeDiskSpace(const GetFreeDiskSpaceCallback& callback,
+                          dbus::Response* response) {
+    if (!response) {
+      callback.Run(DBUS_METHOD_CALL_FAILURE, 0);
+      return;
+    }
+    dbus::MessageReader reader(response);
+    uint64_t disk_free_bytes = 0;
+    if (!reader.PopUint64(&disk_free_bytes)) {
+      LOG(ERROR) << "Invalid response: " << response->ToString();
+      return;

[hidehiko, 2016/07/14 07:39:40]

isn't it necessary to invoke callback.Run(FAILURE, ...); ?
Some methods around here do, and some other don't.
I cannot figure out the difference of them, though...

[Shuhei Takahashi, 2016/07/14 08:44:27]

Yup, I think that's good to call failure callback. Done.

+    }
+    callback.Run(DBUS_METHOD_CALL_SUCCESS, disk_free_bytes);
+  }
+
   // Handles the result of GetSystemSalt().
   void OnGetSystemSalt(const GetSystemSaltCallback& callback,
                        dbus::Response* response) {
     if (!response) {
       callback.Run(DBUS_METHOD_CALL_FAILURE, std::vector<uint8_t>());
       return;
     }
     dbus::MessageReader reader(response);
     const uint8_t* bytes = NULL;
     size_t length = 0;
@@ skipping 236 matching lines @@
   return new CryptohomeClientImpl();
 }
 
 // static
 std::string CryptohomeClient::GetStubSanitizedUsername(
     const cryptohome::Identification& cryptohome_id) {
   return cryptohome_id.id() + kUserIdStubHashSuffix;
 }
 
 }  // namespace chromeos