Support swap partitions and logical volumes in DiskCustomization (COMPOSER-2400)

pkg/blueprint/disk_customizations.go

@@ -75,6 +75,9 @@ type PartitionCustomization struct {
 //   - Does not define a size. The size is defined by its container: a
 //     partition ([PartitionCustomization]) or LVM logical volume
 //     ([LVCustomization]).
+//
+// Setting the FSType to "swap" creates a swap area (and the Mountpoint must be
+// empty).
 type FilesystemTypedCustomization struct {
 	Mountpoint string `json:"mountpoint" toml:"mountpoint"`
 	Label      string `json:"label,omitempty" toml:"label,omitempty"`
@@ -332,6 +335,7 @@ func (v *PartitionCustomization) UnmarshalTOML(data any) error {
 //   - Plain filesystem types are valid for the partition type
 //   - All non-empty properties are valid for the partition type (e.g.
 //     LogicalVolumes is empty when the type is "plain" or "btrfs")
+//   - Filesystems with FSType set to "swap" do not specify a mountpoint.
 //
 // Note that in *addition* consumers should also call
 // ValidateLayoutConstraints() to validate that the policy for disk
@@ -450,6 +454,14 @@ var validPlainFSTypes = []string{
 }
 
 func (p *PartitionCustomization) validatePlain(mountpoints map[string]bool) error {
+	if p.FSType == "swap" {
+		// make sure the mountpoint is empty and return
+		if p.Mountpoint != "" {
+			return fmt.Errorf("mountpoint for swap partition must be empty (got %q)", p.Mountpoint)
+		}
+		return nil
+	}
+
 	if err := validateMountpoint(p.Mountpoint); err != nil {
 		return err
 	}
@@ -490,6 +502,13 @@ func (p *PartitionCustomization) validateLVM(mountpoints, vgnames map[string]boo
 		}
 		lvnames[lv.Name] = true
 
+		if lv.FSType == "swap" {
+			// make sure the mountpoint is empty and return
+			if lv.Mountpoint != "" {
+				return fmt.Errorf("mountpoint for swap logical volume with name %q in volume group %q must be empty", lv.Name, p.Name)
+			}
+			return nil
+		}
 		if err := validateMountpoint(lv.Mountpoint); err != nil {
 			return fmt.Errorf("invalid logical volume customization: %w", err)
 		}
@@ -560,7 +579,9 @@ func CheckDiskMountpointsPolicy(partitioning *DiskCustomization, mountpointAllow
 			mountpoints = append(mountpoints, part.Mountpoint)
 		}
 		for _, lv := range part.LogicalVolumes {
-			mountpoints = append(mountpoints, lv.Mountpoint)
+			if lv.Mountpoint != "" {
+				mountpoints = append(mountpoints, lv.Mountpoint)
+			}
 		}
 		for _, subvol := range part.Subvolumes {
 			mountpoints = append(mountpoints, subvol.Mountpoint)

pkg/blueprint/disk_customizations_test.go

@@ -37,7 +37,7 @@ func TestPartitioningValidation(t *testing.T) {
 			},
 			expectedMsg: "",
 		},
-		"happy-plain+btrfs": {
+		"happy-plain+btrfs+swap": {
 			partitioning: &blueprint.DiskCustomization{
 				Partitions: []blueprint.PartitionCustomization{
 					{
@@ -46,6 +46,11 @@ func TestPartitioningValidation(t *testing.T) {
 							Mountpoint: "/data",
 						},
 					},
+					{
+						FilesystemTypedCustomization: blueprint.FilesystemTypedCustomization{
+							FSType: "swap",
+						},
+					},
 					{
 						Type: "btrfs",
 						BtrfsVolumeCustomization: blueprint.BtrfsVolumeCustomization{
@@ -89,6 +94,39 @@ func TestPartitioningValidation(t *testing.T) {
 			},
 			expectedMsg: "",
 		},
+		"happy-plain+lvm-with-swap": {
+			partitioning: &blueprint.DiskCustomization{
+				Partitions: []blueprint.PartitionCustomization{
+					{
+						Type: "plain",
+						FilesystemTypedCustomization: blueprint.FilesystemTypedCustomization{
+							FSType:     "xfs",
+							Mountpoint: "/data",
+						},
+					},
+					{
+						Type: "lvm",
+						VGCustomization: blueprint.VGCustomization{
+							Name: "root",
+							LogicalVolumes: []blueprint.LVCustomization{
+								{
+									FilesystemTypedCustomization: blueprint.FilesystemTypedCustomization{
+										FSType:     "ext4",
+										Mountpoint: "/",
+									},
+								},
+								{
+									FilesystemTypedCustomization: blueprint.FilesystemTypedCustomization{
+										FSType: "swap",
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+			expectedMsg: "",
+		},
 		"happy-plain-with-boot-and-efi": {
 			partitioning: &blueprint.DiskCustomization{
 				Partitions: []blueprint.PartitionCustomization{
@@ -825,6 +863,47 @@ func TestPartitioningValidation(t *testing.T) {
 			},
 			expectedMsg: "invalid partitioning customizations:\nunknown partition type: what",
 		},
+		"unhappy-swap-with-mountpoint": {
+			partitioning: &blueprint.DiskCustomization{
+				Partitions: []blueprint.PartitionCustomization{
+					{
+						FilesystemTypedCustomization: blueprint.FilesystemTypedCustomization{
+							FSType:     "ext4",
+							Mountpoint: "/home",
+						},
+					},
+					{
+						FilesystemTypedCustomization: blueprint.FilesystemTypedCustomization{
+							FSType:     "swap",
+							Mountpoint: "/swap",
+						},
+					},
+				},
+			},
+			expectedMsg: "invalid partitioning customizations:\nmountpoint for swap partition must be empty (got \"/swap\")",
+		},
+		"unhappy-swaplv-with-mountpoint": {
+			partitioning: &blueprint.DiskCustomization{
+				Partitions: []blueprint.PartitionCustomization{
+					{
+						Type: "lvm",
+						VGCustomization: blueprint.VGCustomization{
+							Name: "badvg",
+							LogicalVolumes: []blueprint.LVCustomization{
+								{
+									Name: "swappylv",
+									FilesystemTypedCustomization: blueprint.FilesystemTypedCustomization{
+										FSType:     "swap",
+										Mountpoint: "/var/swap",
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+			expectedMsg: "invalid partitioning customizations:\nmountpoint for swap logical volume with name \"swappylv\" in volume group \"badvg\" must be empty",
+		},
 	}
 
 	for name := range testCases {

pkg/disk/btrfs.go

@@ -155,6 +155,10 @@ func (bs *BtrfsSubvolume) GetMountpoint() string {
 	return bs.Mountpoint
 }
 
+func (bs *BtrfsSubvolume) GetFSFile() string {
+	return bs.GetMountpoint()
+}
+
 func (bs *BtrfsSubvolume) GetFSType() string {
 	return "btrfs"
 }

pkg/disk/btrfs_test.go

@@ -34,4 +34,5 @@ func TestImplementsInterfacesCompileTimeCheckBtrfs(t *testing.T) {
 	var _ = UniqueEntity(&Btrfs{})
 	var _ = Mountable(&BtrfsSubvolume{})
 	var _ = Sizeable(&BtrfsSubvolume{})
+	var _ = FSTabEntity(&BtrfsSubvolume{})
 }

pkg/disk/disk.go

@@ -56,6 +56,8 @@ const (
 
 	RootPartitionUUID = "6264D520-3FB9-423F-8AB8-7A0A8E3D3562"
 
+	SwapPartitionGUID = "0657FD6D-A4AB-43C4-84E5-0933C84B4F4F"
+
 	// Extended Boot Loader Partition
 	XBootLDRPartitionGUID = "BC13C2FF-59E6-4262-A352-B275FD6F7172"
 
@@ -70,6 +72,9 @@ const (
 
 	// Partition type ID for ESP on dos
 	DosESPID = "ef00"
+
+	// Partition type ID for swap
+	DosSwapID = "82"
 )
 
 // pt type -> type -> ID mapping for convenience
@@ -80,13 +85,15 @@ var idMap = map[PartitionTableType]map[string]string{
 		"data": DosLinuxTypeID,
 		"esp":  DosESPID,
 		"lvm":  DosLinuxTypeID,
+		"swap": DosSwapID,
 	},
 	PT_GPT: {
 		"bios": BIOSBootPartitionGUID,
 		"boot": XBootLDRPartitionGUID,
 		"data": FilesystemDataGUID,
 		"esp":  EFISystemPartitionGUID,
 		"lvm":  LVMPartitionGUID,
+		"swap": SwapPartitionGUID,
 	},
 }
 
@@ -248,13 +255,21 @@ type Mountable interface {
 	// GetMountPoint returns the path of the mount point.
 	GetMountpoint() string
 
-	// GetFSType returns the file system type, e.g. 'xfs'.
-	GetFSType() string
+	FSTabEntity
+}
 
-	// GetFSSpec returns the file system spec information.
+// FSTabEntity describes any entity that can appear in the fstab file.
+type FSTabEntity interface {
+	// FSSpec for the entity (UUID and Label); the first field of fstab(5).
 	GetFSSpec() FSSpec
 
-	// GetFSTabOptions returns options for mounting the entity.
+	// The mount point (target) for a filesystem or "none" for swap areas; the second field of fstab(5).
+	GetFSFile() string
+
+	// The type of the filesystem or swap for swap areas; the third field of fstab(5).
+	GetFSType() string
+
+	// The mount options, freq, and passno for the entity; the fourth fifth, and sixth fields of fstab(5) respectively.
 	GetFSTabOptions() (FSTabOptions, error)
 }