Migrate data from reserved table to host_storages

https://bugzilla.redhat.com/show_bug.cgi?id=1337552

db/migrate/20160713141244_upgrade_host_storage_from_reserved.rb

@@ -0,0 +1,23 @@
+class UpgradeHostStorageFromReserved < ActiveRecord::Migration[5.0]
+  class HostStorage < ActiveRecord::Base
+    include ReservedMixin
+    include MigrationStubHelper
+  end
+
+  def up
+    say_with_time("Migrate data from reserved table to host_storages") do
+      HostStorage.includes(:reserved_rec).each do |hs|
+        hs.reserved_hash_migrate(:ems_ref)
+      end
+    end
+  end
+
+  def down
+    say_with_time("Migrate data from host_storages to reserved table") do
+      HostStorage.includes(:reserved_rec).each do |hs|
+        hs.reserved_hash_set(:ems_ref, hs.ems_ref)
+        hs.save!
+      end
+    end
+  end
+end