providers/virtualbox: don't do transient by default

CHANGELOG.md

@@ -2,9 +2,6 @@
 
 BACKWARDS INCOMPATIBILITIES:
 
-  - providers/virtualbox: Shared folders backed by VirtualBox are now
-      "transient". They will be removed if you reboot outside of Vagrant.
-      Always use `vagrant reload`.
   - Deprecated: `halt_timeout` and `halt_check_interval` settings for
       SmartOS, Solaris, and Solaris11 guests. These will be fully
       removed in 1.7. A warning will be shown if they're in use in

plugins/providers/docker/action/host_machine_sync_folders.rb

@@ -117,6 +117,11 @@ module VagrantPlugins
               # Add this synced folder onto the new config if we haven't
               # already shared it before.
               if !existing_ids.has_key?(id)
+                # A bit of a hack for VirtualBox to mount our
+                # folder as transient. This can be removed once
+                # the VirtualBox synced folder mechanism is smarter.
+                data[:virtualbox__transient] = true
+
                 new_config.synced_folder(
                   data[:hostpath],
                   data[:guestpath],

plugins/providers/virtualbox/synced_folder.rb

@@ -9,23 +9,12 @@ module VagrantPlugins
           machine.provider_config.functional_vboxsf
       end
 
+      def prepare(machine, folders, _opts)
+        share_folders(machine, folders, false)
+      end
+
       def enable(machine, folders, _opts)
-        # Export the shared folders to the VM
+        share_folders(machine, folders, true)
-        defs = []
-        folders.each do |id, data|
-          hostpath = data[:hostpath]
-          if !data[:hostpath_exact]
-            hostpath = Vagrant::Util::Platform.cygwin_windows_path(hostpath)
-          end
-
-          defs << {
-            name: os_friendly_id(id),
-            hostpath: hostpath.to_s,
-            transient: true,
-          }
-        end
-
-        driver(machine).share_folders(defs)
 
         # short guestpaths first, so we don't step on ourselves
         folders = folders.sort_by do |id, data|
@@ -94,6 +83,34 @@ module VagrantPlugins
       def os_friendly_id(id)
         id.gsub(/[\/]/,'_').sub(/^_/, '')
       end
+
+      # share_folders sets up the shared folder definitions on the
+      # VirtualBox VM.
+      #
+      # The transient parameter determines if we're FORCING transient
+      # or not. If this is false, then any shared folders will be
+      # shared as non-transient unless they've specifically asked for
+      # transient.
+      def share_folders(machine, folders, transient)
+        defs = []
+        folders.each do |id, data|
+          hostpath = data[:hostpath]
+          if !data[:hostpath_exact]
+            hostpath = Vagrant::Util::Platform.cygwin_windows_path(hostpath)
+          end
+
+          # Only setup the shared folders that match our transient level
+          if (!!data[:transient]) == transient
+            defs << {
+              name: os_friendly_id(id),
+              hostpath: hostpath.to_s,
+              transient: transient,
+            }
+          end
+        end
+
+        driver(machine).share_folders(defs)
+      end
     end
   end
 end