Extend storage D-Bus API (#1071)

## Problem

The current result of the storage proposal is presented as a list of
actions, which could make a bit complex to understand the overall
picture of the resulting devices.

That list of actions is going to be replaced by a more visual
representation of the devices. To make this possible, more information
about the devices has to be exported on D-Bus.

* Part of https://trello.com/c/7TTVVquM.

## Solution

Add the following information to D-Bus:

* The list of actions includes the SID of the affected device.
* The partition table exports the unused slots.
* The LVM devices (volume groups, physical volumes and logical volumes)
are exported.
* The block devices includes their start block and also indicates
whether the device is encrypted.
* The staging devices are exported. 

NOTE: This PR goes to a feature branch instead of master.

## Testing

* Added unit tests
* Tested manually

service/.rubocop.yml

@@ -8,7 +8,7 @@ AllCops:
   Exclude:
     - vendor/**/*
     - lib/agama/dbus/y2dir/**/*
-    - agama.gemspec
+    - agama-yast.gemspec
     - package/*.spec
 
 # a D-Bus method definition may take up more line lenght than usual

service/lib/agama/dbus/base_tree.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-# Copyright (c) [2023] SUSE LLC
+# Copyright (c) [2023-2024] SUSE LLC
 #
 # All Rights Reserved.
 #
@@ -47,11 +47,16 @@ def initialize(service, root_path, logger: nil)
       #
       # @param objects [Array]
       def objects=(objects)
-        try_add_objects(objects)
         try_update_objects(objects)
+        try_add_objects(objects)
         try_delete_objects(objects)
       end
 
+      # Unexports the current D-Bus objects of this tree.
+      def clean
+        dbus_objects.each { |o| service.unexport(o) }
+      end
+
     private
 
       # @return [::DBus::ObjectServer]

service/lib/agama/dbus/storage/device.rb

@@ -30,8 +30,15 @@ module Storage
       #
       # The D-Bus object includes the required interfaces for the storage object that it represents.
       class Device < BaseObject
-        # @return [Y2Storage::Device]
-        attr_reader :storage_device
+        # sid of the Y2Storage device.
+        #
+        # @note A Y2Storage device is a wrapper over a libstorage-ng object. If the source
+        #   devicegraph does not exist anymore (e.g., after reprobing), then the Y2Storage device
+        #   object cannot be used (memory error). The device sid is stored to avoid accessing to
+        #   the old Y2Storage device when updating the represented device, see {#storage_device=}.
+        #
+        # @return [Integer]
+        attr_reader :sid
 
         # Constructor
         #
@@ -43,6 +50,7 @@ def initialize(storage_device, path, tree, logger: nil)
           super(path, logger: logger)
 
           @storage_device = storage_device
+          @sid = storage_device.sid
           @tree = tree
           add_interfaces
         end
@@ -54,12 +62,13 @@ def initialize(storage_device, path, tree, logger: nil)
         #
         # @param value [Y2Storage::Device]
         def storage_device=(value)
-          if value.sid != storage_device.sid
+          if value.sid != sid
             raise "Cannot update the D-Bus object because the given device has a different sid: " \
-                  "#{value} instead of #{storage_device.sid}"
+                  "#{value} instead of #{sid}"
           end
 
           @storage_device = value
+          @sid = value.sid
 
           interfaces_and_properties.each do |interface, properties|
             dbus_properties_changed(interface, properties, [])
@@ -71,6 +80,9 @@ def storage_device=(value)
         # @return [DevicesTree]
         attr_reader :tree
 
+        # @return [Y2Storage::Device]
+        attr_reader :storage_device
+
         # Adds the required interfaces according to the storage object.
         def add_interfaces
           interfaces = Interfaces::Device.constants

service/lib/agama/dbus/storage/devices_tree.rb

@@ -36,10 +36,19 @@ def path_for(device)
           ::DBus::ObjectPath.new(File.join(root_path, device.sid.to_s))
         end
 
-        # Updates the D-Bus tree according to the given devicegraph
+        # Updates the D-Bus tree according to the given devicegraph.
+        #
+        # @note In the devices tree it is important to avoid updating D-Bus nodes. Note that an
+        #   already exported D-Bus object could require to add or remove interfaces (e.g., an
+        #   existing partition needs to add the Filesystem interface after formatting the
+        #   partition). Dynamically adding or removing interfaces is not possible with ruby-dbus
+        #   once the object is exported on D-Bus.
+        #
+        #   Updating the currently exported D-Bus objects is avoided by calling to {#clean} first.
         #
         # @param devicegraph [Y2Storage::Devicegraph]
         def update(devicegraph)
+          clean
           self.objects = devices(devicegraph)
         end
 
@@ -52,31 +61,34 @@ def create_dbus_object(device)
         end
 
         # @see BaseTree
-        # @param dbus_object [Device]
-        # @param device [Y2Storage::Device]
-        def update_dbus_object(dbus_object, device)
-          dbus_object.storage_device = device
+        #
+        # @note D-Bus objects representing devices cannot be safely updated, see {#update}.
+        def update_dbus_object(_dbus_object, _device)
+          nil
         end
 
         # @see BaseTree
         # @param dbus_object [Device]
         # @param device [Y2Storage::Device]
         def dbus_object?(dbus_object, device)
-          dbus_object.storage_device.sid == device.sid
+          dbus_object.sid == device.sid
         end
 
         # Devices to be exported.
         #
         # Right now, only the required information for calculating a proposal is exported, that is:
         # * Potential candidate devices (i.e., disk devices, MDs).
         # * Partitions of the candidate devices in order to indicate how to find free space.
-        #
-        # TODO: export LVM VGs and file systems of directly formatted devices.
+        # * LVM volume groups and logical volumes.
         #
         # @param devicegraph [Y2Storage::Devicegraph]
         # @return [Array<Y2Storage::Device>]
         def devices(devicegraph)
-          devices = devicegraph.disk_devices + devicegraph.software_raids
+          devices = devicegraph.disk_devices +
+            devicegraph.software_raids +
+            devicegraph.lvm_vgs +
+            devicegraph.lvm_lvs
+
           devices + partitions_from(devices)
         end
 

service/lib/agama/dbus/storage/interfaces/device.rb

@@ -35,6 +35,7 @@ module Device
 require "agama/dbus/storage/interfaces/device/component"
 require "agama/dbus/storage/interfaces/device/drive"
 require "agama/dbus/storage/interfaces/device/filesystem"
+require "agama/dbus/storage/interfaces/device/lvm_vg"
 require "agama/dbus/storage/interfaces/device/md"
 require "agama/dbus/storage/interfaces/device/multipath"
 require "agama/dbus/storage/interfaces/device/partition_table"

service/lib/agama/dbus/storage/interfaces/device/block.rb

@@ -51,13 +51,27 @@ def block_name
               storage_device.name
             end
 
+            # Position of the first block of the region.
+            #
+            # @return [Integer]
+            def block_start
+              storage_device.start
+            end
+
             # Whether the block device is currently active
             #
             # @return [Boolean]
             def block_active
               storage_device.active?
             end
 
+            # Whether the block device is encrypted.
+            #
+            # @return [Boolean]
+            def block_encrypted
+              storage_device.encrypted?
+            end
+
             # Name of the udev by-id links
             #
             # @return [Array<String>]
@@ -100,7 +114,9 @@ def self.included(base)
               base.class_eval do
                 dbus_interface BLOCK_INTERFACE  do
                   dbus_reader :block_name, "s", dbus_name: "Name"
+                  dbus_reader :block_start, "t", dbus_name: "Start"
                   dbus_reader :block_active, "b", dbus_name: "Active"
+                  dbus_reader :block_encrypted, "b", dbus_name: "Encrypted"
                   dbus_reader :block_udev_ids, "as", dbus_name: "UdevIds"
                   dbus_reader :block_udev_paths, "as", dbus_name: "UdevPaths"
                   dbus_reader :block_size, "t", dbus_name: "Size"

service/lib/agama/dbus/storage/interfaces/device/component.rb

@@ -84,6 +84,8 @@ def self.included(base)
               base.class_eval do
                 dbus_interface COMPONENT_INTERFACE do
                   dbus_reader :component_type, "s", dbus_name: "Type"
+                  # The names are provided just in case the device is component of a device that
+                  # is not exported yet (e.g., Bcache devices).
                   dbus_reader :component_device_names, "as", dbus_name: "DeviceNames"
                   dbus_reader :component_devices, "ao", dbus_name: "Devices"
                 end

service/lib/agama/dbus/storage/interfaces/device/lvm_vg.rb

@@ -0,0 +1,90 @@
+# frozen_string_literal: true
+
+# Copyright (c) [2024] SUSE LLC
+#
+# All Rights Reserved.
+#
+# This program is free software; you can redistribute it and/or modify it
+# under the terms of version 2 of the GNU General Public License as published
+# by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+# more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, contact SUSE LLC.
+#
+# To contact SUSE LLC about this file by physical or electronic mail, you may
+# find current contact information at www.suse.com.
+
+require "dbus"
+
+module Agama
+  module DBus
+    module Storage
+      module Interfaces
+        module Device
+          # Interface for a LVM Volume Group.
+          #
+          # @note This interface is intended to be included by {Agama::DBus::Storage::Device} if
+          #   needed.
+          module LvmVg
+            # Whether this interface should be implemented for the given device.
+            #
+            # @note LVM Volume Groups implement this interface.
+            #
+            # @param storage_device [Y2Storage::Device]
+            # @return [Boolean]
+            def self.apply?(storage_device)
+              storage_device.is?(:lvm_vg)
+            end
+
+            VOLUME_GROUP_INTERFACE = "org.opensuse.Agama.Storage1.LVM.VolumeGroup"
+            private_constant :VOLUME_GROUP_INTERFACE
+
+            # Name of the volume group
+            #
+            # @return [String] e.g., "/dev/mapper/vg0"
+            def lvm_vg_name
+              storage_device.name
+            end
+
+            # Size of the volume group in bytes
+            #
+            # @return [Integer]
+            def lvm_vg_size
+              storage_device.size.to_i
+            end
+
+            # D-Bus paths of the objects representing the physical volumes.
+            #
+            # @return [Array<String>]
+            def lvm_vg_pvs
+              storage_device.lvm_pvs.map { |p| tree.path_for(p.plain_blk_device) }
+            end
+
+            # D-Bus paths of the objects representing the logical volumes.
+            #
+            # @return [Array<String>]
+            def lvm_vg_lvs
+              storage_device.lvm_lvs.map { |l| tree.path_for(l) }
+            end
+
+            def self.included(base)
+              base.class_eval do
+                dbus_interface VOLUME_GROUP_INTERFACE do
+                  dbus_reader :lvm_vg_name, "s", dbus_name: "Name"
+                  dbus_reader :lvm_vg_size, "t", dbus_name: "Size"
+                  dbus_reader :lvm_vg_pvs, "ao", dbus_name: "PhysicalVolumes"
+                  dbus_reader :lvm_vg_lvs, "ao", dbus_name: "LogicalVolumes"
+                end
+              end
+            end
+          end
+        end
+      end
+    end
+  end
+end

service/lib/agama/dbus/storage/interfaces/device/partition_table.rb

@@ -60,11 +60,22 @@ def partition_table_partitions
               storage_device.partition_table.partitions.map { |p| tree.path_for(p) }
             end
 
+            # Available slots within a partition table, that is, the spaces that can be used to
+            # create a new partition.
+            #
+            # @return [Array<Array(Integer, Integer)>] The first block and the size of each slot.
+            def partition_table_unused_slots
+              storage_device.partition_table.unused_partition_slots.map do |slot|
+                [slot.region.start, slot.region.size.to_i]
+              end
+            end
+
             def self.included(base)
               base.class_eval do
                 dbus_interface PARTITION_TABLE_INTERFACE do
                   dbus_reader :partition_table_type, "s", dbus_name: "Type"
                   dbus_reader :partition_table_partitions, "ao", dbus_name: "Partitions"
+                  dbus_reader :partition_table_unused_slots, "a(tt)", dbus_name: "UnusedSlots"
                 end
               end
             end

service/lib/agama/dbus/storage/manager.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-# Copyright (c) [2022-2023] SUSE LLC
+# Copyright (c) [2022-2024] SUSE LLC
 #
 # All Rights Reserved.
 #
@@ -289,6 +289,7 @@ def register_proposal_callbacks
           proposal.on_calculate do
             export_proposal
             proposal_properties_changed
+            refresh_staging_devices
           end
         end
 
@@ -332,6 +333,11 @@ def refresh_system_devices
           system_devices_tree.update(devicegraph)
         end
 
+        def refresh_staging_devices
+          devicegraph = Y2Storage::StorageManager.instance.staging
+          staging_devices_tree.update(devicegraph)
+        end
+
         def refresh_iscsi_nodes
           nodes = backend.iscsi.nodes
           iscsi_nodes_tree.update(nodes)
@@ -348,6 +354,10 @@ def system_devices_tree
           @system_devices_tree ||= DevicesTree.new(@service, tree_path("system"), logger: logger)
         end
 
+        def staging_devices_tree
+          @staging_devices_tree ||= DevicesTree.new(@service, tree_path("staging"), logger: logger)
+        end
+
         def tree_path(tree_root)
           File.join(PATH, tree_root)
         end

service/lib/agama/dbus/storage/proposal.rb

@@ -155,6 +155,7 @@ def dbus_settings
         # @return [Hash]
         def to_dbus_action(action)
           {
+            "Device" => action.target_device.sid,
             "Text"   => action.sentence,
             "Subvol" => action.device_is?(:btrfs_subvolume),
             "Delete" => action.delete?