diff --git a/common/dynamic_partition_control_interface.h b/common/dynamic_partition_control_interface.h
index 58ebfe4..7289dee 100644
--- a/common/dynamic_partition_control_interface.h
+++ b/common/dynamic_partition_control_interface.h
@@ -21,6 +21,7 @@
 
 #include <memory>
 #include <string>
+#include <vector>
 
 #include "update_engine/common/action.h"
 #include "update_engine/common/cleanup_previous_update_action_delegate.h"
@@ -118,6 +119,17 @@
   // progress, while ResetUpdate() forcefully free previously
   // allocated space for snapshot updates.
   virtual bool ResetUpdate(PrefsInterface* prefs) = 0;
+
+  // Reads the dynamic partitions metadata from the current slot, and puts the
+  // name of the dynamic partitions with the current suffix to |partitions|.
+  // Returns true on success.
+  virtual bool ListDynamicPartitionsForSlot(
+      uint32_t current_slot, std::vector<std::string>* partitions) = 0;
+
+  // Finds a possible location that list all block devices by name; and puts
+  // the result in |path|. Returns true on success.
+  // Sample result: /dev/block/by-name/
+  virtual bool GetDeviceDir(std::string* path) = 0;
 };
 
 }  // namespace chromeos_update_engine
diff --git a/common/dynamic_partition_control_stub.cc b/common/dynamic_partition_control_stub.cc
index 903b7ee..cde36af 100644
--- a/common/dynamic_partition_control_stub.cc
+++ b/common/dynamic_partition_control_stub.cc
@@ -67,4 +67,13 @@
   return false;
 }
 
+bool DynamicPartitionControlStub::ListDynamicPartitionsForSlot(
+    uint32_t current_slot, std::vector<std::string>* partitions) {
+  return true;
+}
+
+bool DynamicPartitionControlStub::GetDeviceDir(std::string* path) {
+  return true;
+}
+
 }  // namespace chromeos_update_engine
diff --git a/common/dynamic_partition_control_stub.h b/common/dynamic_partition_control_stub.h
index d8e254e..28e3e6a 100644
--- a/common/dynamic_partition_control_stub.h
+++ b/common/dynamic_partition_control_stub.h
@@ -21,6 +21,7 @@
 
 #include <memory>
 #include <string>
+#include <vector>
 
 #include "update_engine/common/dynamic_partition_control_interface.h"
 
@@ -46,6 +47,10 @@
       PrefsInterface* prefs,
       CleanupPreviousUpdateActionDelegateInterface* delegate) override;
   bool ResetUpdate(PrefsInterface* prefs) override;
+
+  bool ListDynamicPartitionsForSlot(
+      uint32_t current_slot, std::vector<std::string>* partitions) override;
+  bool GetDeviceDir(std::string* path) override;
 };
 
 }  // namespace chromeos_update_engine