Fix: resize GuestOS disk

cmd/limactl/edit.go

@@ -157,6 +157,12 @@ func editAction(cmd *cobra.Command, args []string) error {
 	if err != nil {
 		return err
 	}
+
+	inst, err = store.Inspect(inst.Name)
+	if err != nil {
+		return err
+	}
+
 	return instance.Start(ctx, inst, "", false)
 }
 

pkg/instance/start.go

@@ -18,9 +18,12 @@ import (
 	"time"
 
 	"github.com/coreos/go-semver/semver"
+	"github.com/docker/go-units"
+	"github.com/lima-vm/go-qcow2reader"
 	"github.com/lima-vm/lima/pkg/driver"
 	"github.com/lima-vm/lima/pkg/driverutil"
 	"github.com/lima-vm/lima/pkg/executil"
+	"github.com/lima-vm/lima/pkg/nativeimgutil"
 	"github.com/lima-vm/lima/pkg/osutil"
 	"github.com/lima-vm/lima/pkg/qemu"
 	"github.com/lima-vm/lima/pkg/qemu/entitlementutil"
@@ -101,6 +104,11 @@ func Prepare(ctx context.Context, inst *store.Instance) (*Prepared, error) {
 	if err := limaDriver.CreateDisk(ctx); err != nil {
 		return nil, err
 	}
+
+	if err := prepareDiffDisk(inst); err != nil {
+		return nil, err
+	}
+
 	nerdctlArchiveCache, err := ensureNerdctlArchiveCache(ctx, inst.Config, created)
 	if err != nil {
 		return nil, err
@@ -386,3 +394,61 @@ func ShowMessage(inst *store.Instance) error {
 	}
 	return scanner.Err()
 }
+
+// prepareDiffDisk checks the disk size difference between inst.Disk and yaml.Disk.
+// It reuses ResizeDataDisk() by mimicking diffDisk as a Lima disk.
+func prepareDiffDisk(inst *store.Instance) error {
+	diffDisk := filepath.Join(inst.Dir, filenames.DiffDisk)
+
+	f, err := os.Open(diffDisk)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	img, err := qcow2reader.Open(f)
+	if err != nil {
+		return err
+	}
+
+	diskSize := img.Size()
+	format := string(img.Type())
+
+	if inst.Disk == diskSize {
+		logrus.Infof("diffDisk size does not changed")
+		return nil
+	}
+
+	logrus.Infof("Resize instance %s's disk from %s to %s", inst.Name, units.BytesSize(float64(diskSize)), units.BytesSize(float64(inst.Disk)))
+
+	if inst.Disk < diskSize {
+		inst.Disk = diskSize
+		return errors.New("diffDisk: Shrinking is currently unavailable")
+	}
+
+	tmpDiskDir := filepath.Join(filenames.DisksDir, inst.Name+"-tmp")
+	if err := os.MkdirAll(tmpDiskDir, 0o755); err != nil {
+		return err
+	}
+
+	// Unsure whether to copy the file back and forth or use a symlink.
+	if err := os.Symlink(diffDisk, filepath.Join(tmpDiskDir, filenames.DataDisk)); err != nil {
+		return err
+	}
+
+	if format == "raw" {
+		err = nativeimgutil.ResizeRawDataDisk(tmpDiskDir, int(inst.Disk))
+	} else {
+		err = qemu.ResizeDataDisk(tmpDiskDir, format, int(inst.Disk))
+	}
+
+	if err != nil {
+		return err
+	}
+
+	if err := os.RemoveAll(tmpDiskDir); err != nil {
+		return fmt.Errorf("failed to remove %q: %w", tmpDiskDir, err)
+	}
+
+	return err
+}