diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 87a6e721..50d3474c 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -40,7 +40,7 @@ jobs:
           username: fluxcdbot
           password: ${{ secrets.DOCKER_FLUXCD_PASSWORD }}
       - name: Publish amd64 image
-        uses: docker/build-push-action@v2-build-push
+        uses: docker/build-push-action@v2
         with:
           push: ${{ github.event_name != 'pull_request' }}
           builder: ${{ steps.buildx.outputs.name }}
@@ -51,7 +51,7 @@ jobs:
             ghcr.io/fluxcd/source-controller:${{ steps.get_version.outputs.VERSION }}
             docker.io/fluxcd/source-controller:${{ steps.get_version.outputs.VERSION }}
       - name: Publish arm64 image
-        uses: docker/build-push-action@v2-build-push
+        uses: docker/build-push-action@v2
         with:
           push: ${{ github.event_name != 'pull_request' }}
           builder: ${{ steps.buildx.outputs.name }}
diff --git a/api/v1alpha1/gitrepository_types.go b/api/v1alpha1/gitrepository_types.go
index 2be87e6b..c795765e 100644
--- a/api/v1alpha1/gitrepository_types.go
+++ b/api/v1alpha1/gitrepository_types.go
@@ -99,6 +99,11 @@ type GitRepositoryVerification struct {
 
 // GitRepositoryStatus defines the observed state of a Git repository.
 type GitRepositoryStatus struct {
+	// ObservedGeneration is the last observed generation.
+	// +optional
+	ObservedGeneration int64 `json:"observedGeneration,omitempty"`
+
+	// Conditions holds the conditions for the GitRepository.
 	// +optional
 	Conditions []SourceCondition `json:"conditions,omitempty"`
 
@@ -122,62 +127,46 @@ const (
 	GitOperationFailedReason string = "GitOperationFailed"
 )
 
-// GitRepositoryReady sets the given artifact and url on the
-// GitRepository and resets the conditions to SourceCondition of
-// type Ready with status true and the given reason and message.
-// It returns the modified GitRepository.
-func GitRepositoryReady(repository GitRepository, artifact Artifact, url, reason, message string) GitRepository {
-	repository.Status.Conditions = []SourceCondition{
-		{
-			Type:               ReadyCondition,
-			Status:             corev1.ConditionTrue,
-			LastTransitionTime: metav1.Now(),
-			Reason:             reason,
-			Message:            message,
-		},
-	}
-	repository.Status.URL = url
-
-	if repository.Status.Artifact != nil {
-		if repository.Status.Artifact.Path != artifact.Path {
-			repository.Status.Artifact = &artifact
-		}
-	} else {
-		repository.Status.Artifact = &artifact
-	}
-
-	return repository
-}
-
 // GitRepositoryProgressing resets the conditions of the GitRepository
 // to SourceCondition of type Ready with status unknown and
 // progressing reason and message. It returns the modified GitRepository.
 func GitRepositoryProgressing(repository GitRepository) GitRepository {
-	repository.Status.Conditions = []SourceCondition{
-		{
-			Type:               ReadyCondition,
-			Status:             corev1.ConditionUnknown,
-			LastTransitionTime: metav1.Now(),
-			Reason:             ProgressingReason,
-			Message:            "reconciliation in progress",
-		},
-	}
+	repository.Status.ObservedGeneration = repository.Generation
+	repository.Status.URL = ""
+	repository.Status.Artifact = nil
+	repository.Status.Conditions = []SourceCondition{}
+	SetGitRepositoryCondition(&repository, ReadyCondition, corev1.ConditionUnknown, ProgressingReason, "reconciliation in progress")
 	return repository
 }
 
-// GitRepositoryNotReady resets the conditions of the GitRepository
-// to SourceCondition of type Ready with status false and the given
-// reason and message. It returns the modified GitRepository.
+// SetGitRepositoryCondition sets the given condition with the given status, reason and message
+// on the GitRepository.
+func SetGitRepositoryCondition(repository *GitRepository, condition string, status corev1.ConditionStatus, reason, message string) {
+	repository.Status.Conditions = filterOutSourceCondition(repository.Status.Conditions, condition)
+	repository.Status.Conditions = append(repository.Status.Conditions, SourceCondition{
+		Type:               condition,
+		Status:             status,
+		LastTransitionTime: metav1.Now(),
+		Reason:             reason,
+		Message:            message,
+	})
+}
+
+// GitRepositoryReady sets the given artifact and url on the GitRepository
+// and sets the ReadyCondition to True, with the given reason and
+// message. It returns the modified GitRepository.
+func GitRepositoryReady(repository GitRepository, artifact Artifact, url, reason, message string) GitRepository {
+	repository.Status.Artifact = &artifact
+	repository.Status.URL = url
+	SetGitRepositoryCondition(&repository, ReadyCondition, corev1.ConditionTrue, reason, message)
+	return repository
+}
+
+// GitRepositoryNotReady sets the ReadyCondition on the given GitRepository
+// to False, with the given reason and message. It returns the modified
+// GitRepository.
 func GitRepositoryNotReady(repository GitRepository, reason, message string) GitRepository {
-	repository.Status.Conditions = []SourceCondition{
-		{
-			Type:               ReadyCondition,
-			Status:             corev1.ConditionFalse,
-			LastTransitionTime: metav1.Now(),
-			Reason:             reason,
-			Message:            message,
-		},
-	}
+	SetGitRepositoryCondition(&repository, ReadyCondition, corev1.ConditionFalse, reason, message)
 	return repository
 }
 
diff --git a/api/v1alpha1/helmchart_types.go b/api/v1alpha1/helmchart_types.go
index f58f9be3..b398fbfd 100644
--- a/api/v1alpha1/helmchart_types.go
+++ b/api/v1alpha1/helmchart_types.go
@@ -62,6 +62,11 @@ type LocalHelmChartSourceReference struct {
 
 // HelmChartStatus defines the observed state of the HelmChart.
 type HelmChartStatus struct {
+	// ObservedGeneration is the last observed generation.
+	// +optional
+	ObservedGeneration int64 `json:"observedGeneration,omitempty"`
+
+	// Conditions holds the conditions for the HelmChart.
 	// +optional
 	Conditions []SourceCondition `json:"conditions,omitempty"`
 
@@ -92,9 +97,10 @@ const (
 	ChartPackageSucceededReason string = "ChartPackageSucceeded"
 )
 
-// HelmReleaseProgressing resets any failures and registers progress toward reconciling the given HelmRelease
+// HelmChartProgressing resets any failures and registers progress toward reconciling the given HelmChart
 // by setting the ReadyCondition to ConditionUnknown for ProgressingReason.
 func HelmChartProgressing(chart HelmChart) HelmChart {
+	chart.Status.ObservedGeneration = chart.Generation
 	chart.Status.URL = ""
 	chart.Status.Artifact = nil
 	chart.Status.Conditions = []SourceCondition{}
diff --git a/api/v1alpha1/helmrepository_types.go b/api/v1alpha1/helmrepository_types.go
index b34f6b63..1870ff32 100644
--- a/api/v1alpha1/helmrepository_types.go
+++ b/api/v1alpha1/helmrepository_types.go
@@ -54,6 +54,11 @@ type HelmRepositorySpec struct {
 
 // HelmRepositoryStatus defines the observed state of the HelmRepository.
 type HelmRepositoryStatus struct {
+	// ObservedGeneration is the last observed generation.
+	// +optional
+	ObservedGeneration int64 `json:"observedGeneration,omitempty"`
+
+	// Conditions holds the conditions for the HelmRepository.
 	// +optional
 	Conditions []SourceCondition `json:"conditions,omitempty"`
 
@@ -76,62 +81,46 @@ const (
 	IndexationSucceededReason string = "IndexationSucceed"
 )
 
-// HelmRepositoryReady sets the given artifact and url on the
-// HelmRepository and resets the conditions to SourceCondition of
-// type Ready with status true and the given reason and message.
-// It returns the modified HelmRepository.
-func HelmRepositoryReady(repository HelmRepository, artifact Artifact, url, reason, message string) HelmRepository {
-	repository.Status.Conditions = []SourceCondition{
-		{
-			Type:               ReadyCondition,
-			Status:             corev1.ConditionTrue,
-			LastTransitionTime: metav1.Now(),
-			Reason:             reason,
-			Message:            message,
-		},
-	}
-	repository.Status.URL = url
-
-	if repository.Status.Artifact != nil {
-		if repository.Status.Artifact.Path != artifact.Path {
-			repository.Status.Artifact = &artifact
-		}
-	} else {
-		repository.Status.Artifact = &artifact
-	}
-
-	return repository
-}
-
 // HelmRepositoryProgressing resets the conditions of the HelmRepository
 // to SourceCondition of type Ready with status unknown and
 // progressing reason and message. It returns the modified HelmRepository.
 func HelmRepositoryProgressing(repository HelmRepository) HelmRepository {
-	repository.Status.Conditions = []SourceCondition{
-		{
-			Type:               ReadyCondition,
-			Status:             corev1.ConditionUnknown,
-			LastTransitionTime: metav1.Now(),
-			Reason:             ProgressingReason,
-			Message:            "reconciliation in progress",
-		},
-	}
+	repository.Status.ObservedGeneration = repository.Generation
+	repository.Status.URL = ""
+	repository.Status.Artifact = nil
+	repository.Status.Conditions = []SourceCondition{}
+	SetHelmRepositoryCondition(&repository, ReadyCondition, corev1.ConditionUnknown, ProgressingReason, "reconciliation in progress")
 	return repository
 }
 
-// HelmRepositoryNotReady resets the conditions of the HelmRepository
-// to SourceCondition of type Ready with status false and the given
-// reason and message. It returns the modified HelmRepository.
+// SetHelmRepositoryCondition sets the given condition with the given status,
+// reason and message on the HelmRepository.
+func SetHelmRepositoryCondition(repository *HelmRepository, condition string, status corev1.ConditionStatus, reason, message string) {
+	repository.Status.Conditions = filterOutSourceCondition(repository.Status.Conditions, condition)
+	repository.Status.Conditions = append(repository.Status.Conditions, SourceCondition{
+		Type:               condition,
+		Status:             status,
+		LastTransitionTime: metav1.Now(),
+		Reason:             reason,
+		Message:            message,
+	})
+}
+
+// HelmRepositoryReady sets the given artifact and url on the HelmRepository
+// and sets the ReadyCondition to True, with the given reason and
+// message. It returns the modified HelmRepository.
+func HelmRepositoryReady(repository HelmRepository, artifact Artifact, url, reason, message string) HelmRepository {
+	repository.Status.Artifact = &artifact
+	repository.Status.URL = url
+	SetHelmRepositoryCondition(&repository, ReadyCondition, corev1.ConditionTrue, reason, message)
+	return repository
+}
+
+// HelmRepositoryNotReady sets the ReadyCondition on the given HelmRepository
+// to False, with the given reason and message. It returns the modified
+// HelmRepository.
 func HelmRepositoryNotReady(repository HelmRepository, reason, message string) HelmRepository {
-	repository.Status.Conditions = []SourceCondition{
-		{
-			Type:               ReadyCondition,
-			Status:             corev1.ConditionFalse,
-			LastTransitionTime: metav1.Now(),
-			Reason:             reason,
-			Message:            message,
-		},
-	}
+	SetHelmRepositoryCondition(&repository, ReadyCondition, corev1.ConditionFalse, reason, message)
 	return repository
 }
 
diff --git a/config/crd/bases/source.toolkit.fluxcd.io_gitrepositories.yaml b/config/crd/bases/source.toolkit.fluxcd.io_gitrepositories.yaml
index e60d5852..81a2249b 100644
--- a/config/crd/bases/source.toolkit.fluxcd.io_gitrepositories.yaml
+++ b/config/crd/bases/source.toolkit.fluxcd.io_gitrepositories.yaml
@@ -153,6 +153,7 @@ spec:
                 - url
                 type: object
               conditions:
+                description: Conditions holds the conditions for the GitRepository.
                 items:
                   description: SourceCondition contains condition information for
                     a source.
@@ -182,6 +183,10 @@ spec:
                   - type
                   type: object
                 type: array
+              observedGeneration:
+                description: ObservedGeneration is the last observed generation.
+                format: int64
+                type: integer
               url:
                 description: URL is the download link for the artifact output of the
                   last repository sync.
diff --git a/config/crd/bases/source.toolkit.fluxcd.io_helmcharts.yaml b/config/crd/bases/source.toolkit.fluxcd.io_helmcharts.yaml
index d1125575..b0a22796 100644
--- a/config/crd/bases/source.toolkit.fluxcd.io_helmcharts.yaml
+++ b/config/crd/bases/source.toolkit.fluxcd.io_helmcharts.yaml
@@ -125,6 +125,7 @@ spec:
                 - url
                 type: object
               conditions:
+                description: Conditions holds the conditions for the HelmChart.
                 items:
                   description: SourceCondition contains condition information for
                     a source.
@@ -154,6 +155,10 @@ spec:
                   - type
                   type: object
                 type: array
+              observedGeneration:
+                description: ObservedGeneration is the last observed generation.
+                format: int64
+                type: integer
               url:
                 description: URL is the download link for the last chart pulled.
                 type: string
diff --git a/config/crd/bases/source.toolkit.fluxcd.io_helmrepositories.yaml b/config/crd/bases/source.toolkit.fluxcd.io_helmrepositories.yaml
index 8f7f675e..25016356 100644
--- a/config/crd/bases/source.toolkit.fluxcd.io_helmrepositories.yaml
+++ b/config/crd/bases/source.toolkit.fluxcd.io_helmrepositories.yaml
@@ -105,6 +105,7 @@ spec:
                 - url
                 type: object
               conditions:
+                description: Conditions holds the conditions for the HelmRepository.
                 items:
                   description: SourceCondition contains condition information for
                     a source.
@@ -134,6 +135,10 @@ spec:
                   - type
                   type: object
                 type: array
+              observedGeneration:
+                description: ObservedGeneration is the last observed generation.
+                format: int64
+                type: integer
               url:
                 description: URL is the download link for the last index fetched.
                 type: string
diff --git a/controllers/gitrepository_controller.go b/controllers/gitrepository_controller.go
index d88f02b1..d62603bf 100644
--- a/controllers/gitrepository_controller.go
+++ b/controllers/gitrepository_controller.go
@@ -28,7 +28,6 @@ import (
 	"github.com/go-git/go-git/v5/plumbing/transport"
 	"github.com/go-logr/logr"
 	corev1 "k8s.io/api/core/v1"
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/types"
 	kuberecorder "k8s.io/client-go/tools/record"
@@ -100,13 +99,8 @@ func (r *GitRepositoryReconciler) Reconcile(req ctrl.Request) (ctrl.Result, erro
 	}
 
 	// set initial status
-	if reset, status := r.shouldResetStatus(repository); reset {
-		repository.Status = status
-		if err := r.Status().Update(ctx, &repository); err != nil {
-			log.Error(err, "unable to update status")
-			return ctrl.Result{Requeue: true}, err
-		}
-	} else {
+	if repository.Generation != repository.Status.ObservedGeneration ||
+		repository.GetArtifact() != nil && !r.Storage.ArtifactExist(*repository.GetArtifact()) {
 		repository = sourcev1.GitRepositoryProgressing(repository)
 		if err := r.Status().Update(ctx, &repository); err != nil {
 			log.Error(err, "unable to update status")
@@ -202,6 +196,16 @@ func (r *GitRepositoryReconciler) reconcile(ctx context.Context, repository sour
 		return sourcev1.GitRepositoryNotReady(repository, sourcev1.GitOperationFailedReason, err.Error()), err
 	}
 
+	// return early on unchanged revision
+	artifact := r.Storage.NewArtifactFor(repository.Kind, repository.GetObjectMeta(), revision, fmt.Sprintf("%s.tar.gz", commit.Hash.String()))
+	if repository.GetArtifact() != nil && repository.GetArtifact().Revision == revision {
+		if artifact.URL != repository.GetArtifact().URL {
+			r.Storage.SetArtifactURL(repository.GetArtifact())
+			repository.Status.URL = r.Storage.SetHostname(repository.Status.URL)
+		}
+		return repository, nil
+	}
+
 	// verify PGP signature
 	if repository.Spec.Verification != nil {
 		err := r.verify(ctx, types.NamespacedName{
@@ -213,11 +217,6 @@ func (r *GitRepositoryReconciler) reconcile(ctx context.Context, repository sour
 		}
 	}
 
-	// TODO(hidde): implement checksum when https://github.com/fluxcd/source-controller/pull/133
-	//   has been merged.
-	artifact := r.Storage.ArtifactFor(repository.Kind, repository.ObjectMeta.GetObjectMeta(),
-		fmt.Sprintf("%s.tar.gz", commit.Hash.String()), revision, "")
-
 	// create artifact dir
 	err = r.Storage.MkdirAll(artifact)
 	if err != nil {
@@ -234,7 +233,7 @@ func (r *GitRepositoryReconciler) reconcile(ctx context.Context, repository sour
 	defer unlock()
 
 	// archive artifact and check integrity
-	if err := r.Storage.Archive(artifact, tmpGit, repository.Spec); err != nil {
+	if err := r.Storage.Archive(&artifact, tmpGit, repository.Spec); err != nil {
 		err = fmt.Errorf("storage archive error: %w", err)
 		return sourcev1.GitRepositoryNotReady(repository, sourcev1.StorageOperationFailedReason, err.Error()), err
 	}
@@ -250,32 +249,6 @@ func (r *GitRepositoryReconciler) reconcile(ctx context.Context, repository sour
 	return sourcev1.GitRepositoryReady(repository, artifact, url, sourcev1.GitOperationSucceedReason, message), nil
 }
 
-// shouldResetStatus returns a boolean indicating if the status of the
-// given repository should be reset.
-func (r *GitRepositoryReconciler) shouldResetStatus(repository sourcev1.GitRepository) (bool, sourcev1.GitRepositoryStatus) {
-	resetStatus := false
-	if repository.Status.Artifact != nil {
-		if !r.Storage.ArtifactExist(*repository.Status.Artifact) {
-			resetStatus = true
-		}
-	}
-
-	if len(repository.Status.Conditions) == 0 || resetStatus {
-		resetStatus = true
-	}
-
-	return resetStatus, sourcev1.GitRepositoryStatus{
-		Conditions: []sourcev1.SourceCondition{
-			{
-				Type:               sourcev1.ReadyCondition,
-				Status:             corev1.ConditionUnknown,
-				Reason:             sourcev1.InitializingReason,
-				LastTransitionTime: metav1.Now(),
-			},
-		},
-	}
-}
-
 // verify returns an error if the PGP signature can't be verified
 func (r *GitRepositoryReconciler) verify(ctx context.Context, publicKeySecret types.NamespacedName, commit *object.Commit) error {
 	if commit.PGPSignature == "" {
@@ -304,10 +277,10 @@ func (r *GitRepositoryReconciler) verify(ctx context.Context, publicKeySecret ty
 // the given repository.
 func (r *GitRepositoryReconciler) gc(repository sourcev1.GitRepository, all bool) error {
 	if all {
-		return r.Storage.RemoveAll(r.Storage.ArtifactFor(repository.Kind, repository.GetObjectMeta(), "", "", ""))
+		return r.Storage.RemoveAll(r.Storage.NewArtifactFor(repository.Kind, repository.GetObjectMeta(), "", ""))
 	}
-	if repository.Status.Artifact != nil {
-		return r.Storage.RemoveAllButCurrent(*repository.Status.Artifact)
+	if repository.GetArtifact() != nil {
+		return r.Storage.RemoveAllButCurrent(*repository.GetArtifact())
 	}
 	return nil
 }
diff --git a/controllers/helmchart_controller.go b/controllers/helmchart_controller.go
index c6e7b720..9ebe88d7 100644
--- a/controllers/helmchart_controller.go
+++ b/controllers/helmchart_controller.go
@@ -23,7 +23,6 @@ import (
 	"net/url"
 	"os"
 	"path"
-	"path/filepath"
 	"strings"
 	"time"
 
@@ -105,7 +104,8 @@ func (r *HelmChartReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
 	}
 
 	// set initial status
-	if chart.Generation == 0 || chart.GetArtifact() != nil && !r.Storage.ArtifactExist(*chart.GetArtifact()) {
+	if chart.Generation != chart.Status.ObservedGeneration ||
+		chart.GetArtifact() != nil && !r.Storage.ArtifactExist(*chart.GetArtifact()) {
 		chart = sourcev1.HelmChartProgressing(chart)
 		if err := r.Status().Update(ctx, &chart); err != nil {
 			log.Error(err, "unable to update status")
@@ -195,6 +195,16 @@ func (r *HelmChartReconciler) reconcileFromHelmRepository(ctx context.Context,
 		return sourcev1.HelmChartNotReady(chart, sourcev1.ChartPullFailedReason, err.Error()), err
 	}
 
+	// return early on unchanged chart version
+	artifact := r.Storage.NewArtifactFor(chart.Kind, chart.GetObjectMeta(), cv.Version, fmt.Sprintf("%s-%s.tgz", cv.Name, cv.Version))
+	if repository.GetArtifact() != nil && repository.GetArtifact().Revision == cv.Version {
+		if artifact.URL != repository.GetArtifact().URL {
+			r.Storage.SetArtifactURL(repository.GetArtifact())
+			repository.Status.URL = r.Storage.SetHostname(repository.Status.URL)
+		}
+		return chart, nil
+	}
+
 	// TODO(hidde): according to the Helm source the first item is not
 	//  always the correct one to pick, check for updates once in awhile.
 	//  Ref: https://github.com/helm/helm/blob/v3.3.0/pkg/downloader/chart_downloader.go#L241
@@ -255,15 +265,6 @@ func (r *HelmChartReconciler) reconcileFromHelmRepository(ctx context.Context,
 		return sourcev1.HelmChartNotReady(chart, sourcev1.ChartPullFailedReason, err.Error()), err
 	}
 
-	chartBytes, err := ioutil.ReadAll(res)
-	if err != nil {
-		return sourcev1.HelmChartNotReady(chart, sourcev1.ChartPullFailedReason, err.Error()), err
-	}
-
-	sum := r.Storage.Checksum(chartBytes)
-	artifact := r.Storage.ArtifactFor(chart.Kind, chart.GetObjectMeta(),
-		fmt.Sprintf("%s-%s-%s.tgz", cv.Name, cv.Version, sum), cv.Version, sum)
-
 	// create artifact dir
 	err = r.Storage.MkdirAll(artifact)
 	if err != nil {
@@ -280,8 +281,7 @@ func (r *HelmChartReconciler) reconcileFromHelmRepository(ctx context.Context,
 	defer unlock()
 
 	// save artifact to storage
-	err = r.Storage.WriteFile(artifact, chartBytes)
-	if err != nil {
+	if err := r.Storage.AtomicWriteFile(&artifact, res, 0644); err != nil {
 		err = fmt.Errorf("unable to write chart file: %w", err)
 		return sourcev1.HelmChartNotReady(chart, sourcev1.StorageOperationFailedReason, err.Error()), err
 	}
@@ -317,7 +317,7 @@ func (r *HelmChartReconciler) getChartRepositoryWithArtifact(ctx context.Context
 		return repository, err
 	}
 
-	if repository.Status.Artifact == nil {
+	if repository.GetArtifact() == nil {
 		err = fmt.Errorf("no repository index artifact found in HelmRepository '%s'", repository.Name)
 	}
 
@@ -362,15 +362,15 @@ func (r *HelmChartReconciler) reconcileFromGitRepository(ctx context.Context,
 	}
 
 	// return early on unchanged chart version
-	if chart.Status.Artifact != nil && chartMetadata.Version == chart.Status.Artifact.Revision {
+	artifact := r.Storage.NewArtifactFor(chart.Kind, chart.ObjectMeta.GetObjectMeta(), chartMetadata.Version, fmt.Sprintf("%s-%s.tgz", chartMetadata.Name, chartMetadata.Version))
+	if chart.GetArtifact() != nil && chart.GetArtifact().Revision == chartMetadata.Version {
+		if artifact.URL != repository.GetArtifact().URL {
+			r.Storage.SetArtifactURL(repository.GetArtifact())
+			repository.Status.URL = r.Storage.SetHostname(repository.Status.URL)
+		}
 		return chart, nil
 	}
 
-	// TODO(hidde): implement checksum when https://github.com/fluxcd/source-controller/pull/133
-	//   has been merged.
-	artifact := r.Storage.ArtifactFor(chart.Kind, chart.ObjectMeta.GetObjectMeta(),
-		fmt.Sprintf("%s-%s.tgz", chartMetadata.Name, chartMetadata.Version), chartMetadata.Version, "")
-
 	// create artifact dir
 	err = r.Storage.MkdirAll(artifact)
 	if err != nil {
@@ -388,22 +388,35 @@ func (r *HelmChartReconciler) reconcileFromGitRepository(ctx context.Context,
 
 	// package chart
 	pkg := action.NewPackage()
-	pkg.Destination = filepath.Dir(r.Storage.LocalPath(artifact))
-	_, err = pkg.Run(chartPath, nil)
+	pkg.Destination = tmpDir
+	src, err := pkg.Run(chartPath, nil)
 	if err != nil {
 		err = fmt.Errorf("chart package error: %w", err)
 		return sourcev1.HelmChartNotReady(chart, sourcev1.ChartPackageFailedReason, err.Error()), err
 	}
 
+	// copy chart package
+	cf, err := os.Open(src)
+	if err != nil {
+		err = fmt.Errorf("failed to open chart package: %w", err)
+		return sourcev1.HelmChartNotReady(chart, sourcev1.StorageOperationFailedReason, err.Error()), err
+	}
+	if err := r.Storage.Copy(&artifact, cf); err != nil {
+		cf.Close()
+		err = fmt.Errorf("failed to copy chart package to storage: %w", err)
+		return sourcev1.HelmChartNotReady(chart, sourcev1.StorageOperationFailedReason, err.Error()), err
+	}
+	cf.Close()
+
 	// update symlink
-	chartUrl, err := r.Storage.Symlink(artifact, fmt.Sprintf("%s-latest.tgz", chartMetadata.Name))
+	cUrl, err := r.Storage.Symlink(artifact, fmt.Sprintf("%s-latest.tgz", chartMetadata.Name))
 	if err != nil {
 		err = fmt.Errorf("storage error: %w", err)
 		return sourcev1.HelmChartNotReady(chart, sourcev1.StorageOperationFailedReason, err.Error()), err
 	}
 
 	message := fmt.Sprintf("Fetched and packaged revision: %s", artifact.Revision)
-	return sourcev1.HelmChartReady(chart, artifact, chartUrl, sourcev1.ChartPackageSucceededReason, message), nil
+	return sourcev1.HelmChartReady(chart, artifact, cUrl, sourcev1.ChartPackageSucceededReason, message), nil
 }
 
 // getGitRepositoryWithArtifact attempts to get the GitRepository for the given
@@ -426,7 +439,7 @@ func (r *HelmChartReconciler) getGitRepositoryWithArtifact(ctx context.Context,
 		return repository, err
 	}
 
-	if repository.Status.Artifact == nil {
+	if repository.GetArtifact() == nil {
 		err = fmt.Errorf("no artifact found for GitRepository '%s'", repository.Name)
 	}
 
@@ -437,10 +450,10 @@ func (r *HelmChartReconciler) getGitRepositoryWithArtifact(ctx context.Context,
 // the given chart.
 func (r *HelmChartReconciler) gc(chart sourcev1.HelmChart, all bool) error {
 	if all {
-		return r.Storage.RemoveAll(r.Storage.ArtifactFor(chart.Kind, chart.GetObjectMeta(), "", "", ""))
+		return r.Storage.RemoveAll(r.Storage.NewArtifactFor(chart.Kind, chart.GetObjectMeta(), "", ""))
 	}
-	if chart.Status.Artifact != nil {
-		return r.Storage.RemoveAllButCurrent(*chart.Status.Artifact)
+	if chart.GetArtifact() != nil {
+		return r.Storage.RemoveAllButCurrent(*chart.GetArtifact())
 	}
 	return nil
 }
diff --git a/controllers/helmrepository_controller.go b/controllers/helmrepository_controller.go
index 5e082381..a368ac40 100644
--- a/controllers/helmrepository_controller.go
+++ b/controllers/helmrepository_controller.go
@@ -17,6 +17,7 @@ limitations under the License.
 package controllers
 
 import (
+	"bytes"
 	"context"
 	"fmt"
 	"io/ioutil"
@@ -29,7 +30,6 @@ import (
 	"helm.sh/helm/v3/pkg/getter"
 	"helm.sh/helm/v3/pkg/repo"
 	corev1 "k8s.io/api/core/v1"
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/types"
 	kuberecorder "k8s.io/client-go/tools/record"
@@ -41,6 +41,7 @@ import (
 
 	"github.com/fluxcd/pkg/recorder"
 	"github.com/fluxcd/pkg/runtime/predicates"
+
 	sourcev1 "github.com/fluxcd/source-controller/api/v1alpha1"
 	"github.com/fluxcd/source-controller/internal/helm"
 )
@@ -103,13 +104,8 @@ func (r *HelmRepositoryReconciler) Reconcile(req ctrl.Request) (ctrl.Result, err
 	}
 
 	// set initial status
-	if reset, status := r.shouldResetStatus(repository); reset {
-		repository.Status = status
-		if err := r.Status().Update(ctx, &repository); err != nil {
-			log.Error(err, "unable to update status")
-			return ctrl.Result{Requeue: true}, err
-		}
-	} else {
+	if repository.Generation != repository.Status.ObservedGeneration ||
+		repository.GetArtifact() != nil && !r.Storage.ArtifactExist(*repository.GetArtifact()) {
 		repository = sourcev1.HelmRepositoryProgressing(repository)
 		if err := r.Status().Update(ctx, &repository); err != nil {
 			log.Error(err, "unable to update status")
@@ -206,32 +202,37 @@ func (r *HelmRepositoryReconciler) reconcile(ctx context.Context, repository sou
 	}
 
 	clientOpts = append(clientOpts, getter.WithTimeout(repository.GetTimeout()))
-
 	res, err := c.Get(u.String(), clientOpts...)
 	if err != nil {
 		return sourcev1.HelmRepositoryNotReady(repository, sourcev1.IndexationFailedReason, err.Error()), err
 	}
 
-	data, err := ioutil.ReadAll(res)
+	b, err := ioutil.ReadAll(res)
 	if err != nil {
 		return sourcev1.HelmRepositoryNotReady(repository, sourcev1.IndexationFailedReason, err.Error()), err
 	}
-
-	i := &repo.IndexFile{}
-	if err := yaml.Unmarshal(data, i); err != nil {
+	i := repo.IndexFile{}
+	if err := yaml.Unmarshal(b, &i); err != nil {
 		return sourcev1.HelmRepositoryNotReady(repository, sourcev1.IndexationFailedReason, err.Error()), err
 	}
+
+	// return early on unchanged generation
+	artifact := r.Storage.NewArtifactFor(repository.Kind, repository.ObjectMeta.GetObjectMeta(), i.Generated.Format(time.RFC3339Nano),
+		fmt.Sprintf("index-%s.yaml", url.PathEscape(i.Generated.Format(time.RFC3339Nano))))
+	if repository.GetArtifact() != nil && repository.GetArtifact().Revision == i.Generated.Format(time.RFC3339Nano) {
+		if artifact.URL != repository.GetArtifact().URL {
+			r.Storage.SetArtifactURL(repository.GetArtifact())
+			repository.Status.URL = r.Storage.SetHostname(repository.Status.URL)
+		}
+		return repository, nil
+	}
+
 	i.SortEntries()
-
-	index, err := yaml.Marshal(i)
+	b, err = yaml.Marshal(&i)
 	if err != nil {
 		return sourcev1.HelmRepositoryNotReady(repository, sourcev1.IndexationFailedReason, err.Error()), err
 	}
 
-	sum := r.Storage.Checksum(index)
-	artifact := r.Storage.ArtifactFor(repository.Kind, repository.ObjectMeta.GetObjectMeta(),
-		fmt.Sprintf("index-%s.yaml", sum), i.Generated.Format(time.RFC3339Nano), sum)
-
 	// create artifact dir
 	err = r.Storage.MkdirAll(artifact)
 	if err != nil {
@@ -248,8 +249,7 @@ func (r *HelmRepositoryReconciler) reconcile(ctx context.Context, repository sou
 	defer unlock()
 
 	// save artifact to storage
-	err = r.Storage.WriteFile(artifact, index)
-	if err != nil {
+	if err := r.Storage.AtomicWriteFile(&artifact, bytes.NewReader(b), 0644); err != nil {
 		err = fmt.Errorf("unable to write repository index file: %w", err)
 		return sourcev1.HelmRepositoryNotReady(repository, sourcev1.StorageOperationFailedReason, err.Error()), err
 	}
@@ -265,41 +265,14 @@ func (r *HelmRepositoryReconciler) reconcile(ctx context.Context, repository sou
 	return sourcev1.HelmRepositoryReady(repository, artifact, indexURL, sourcev1.IndexationSucceededReason, message), nil
 }
 
-// shouldResetStatus returns a boolean indicating if the status of the
-// given repository should be reset.
-func (r *HelmRepositoryReconciler) shouldResetStatus(repository sourcev1.HelmRepository) (bool, sourcev1.HelmRepositoryStatus) {
-	resetStatus := false
-	if repository.Status.Artifact != nil {
-		if !r.Storage.ArtifactExist(*repository.Status.Artifact) {
-			resetStatus = true
-		}
-	}
-
-	// set initial status
-	if len(repository.Status.Conditions) == 0 {
-		resetStatus = true
-	}
-
-	return resetStatus, sourcev1.HelmRepositoryStatus{
-		Conditions: []sourcev1.SourceCondition{
-			{
-				Type:               sourcev1.ReadyCondition,
-				Status:             corev1.ConditionUnknown,
-				Reason:             sourcev1.InitializingReason,
-				LastTransitionTime: metav1.Now(),
-			},
-		},
-	}
-}
-
 // gc performs a garbage collection on all but current artifacts of
 // the given repository.
 func (r *HelmRepositoryReconciler) gc(repository sourcev1.HelmRepository, all bool) error {
 	if all {
-		return r.Storage.RemoveAll(r.Storage.ArtifactFor(repository.Kind, repository.GetObjectMeta(), "", "", ""))
+		return r.Storage.RemoveAll(r.Storage.NewArtifactFor(repository.Kind, repository.GetObjectMeta(), "", ""))
 	}
-	if repository.Status.Artifact != nil {
-		return r.Storage.RemoveAllButCurrent(*repository.Status.Artifact)
+	if repository.GetArtifact() != nil {
+		return r.Storage.RemoveAllButCurrent(*repository.GetArtifact())
 	}
 	return nil
 }
diff --git a/controllers/helmrepository_controller_test.go b/controllers/helmrepository_controller_test.go
index 90b20cab..c596ca73 100644
--- a/controllers/helmrepository_controller_test.go
+++ b/controllers/helmrepository_controller_test.go
@@ -140,7 +140,7 @@ var _ = Describe("HelmRepositoryReconciler", func() {
 			Eventually(func() error {
 				r := &sourcev1.HelmRepository{}
 				return k8sClient.Get(context.Background(), key, r)
-			}).ShouldNot(Succeed())
+			}, timeout, interval).ShouldNot(Succeed())
 
 			exists := func(path string) bool {
 				// wait for tmp sync on macOS
diff --git a/controllers/storage.go b/controllers/storage.go
index a137a39e..41883cc9 100644
--- a/controllers/storage.go
+++ b/controllers/storage.go
@@ -23,8 +23,10 @@ import (
 	"compress/gzip"
 	"crypto/sha1"
 	"fmt"
+	"hash"
 	"io"
 	"io/ioutil"
+	"net/url"
 	"os"
 	"path/filepath"
 	"strings"
@@ -36,6 +38,7 @@ import (
 	"github.com/fluxcd/pkg/lockedfile"
 
 	sourcev1 "github.com/fluxcd/source-controller/api/v1alpha1"
+	"github.com/fluxcd/source-controller/internal/fs"
 )
 
 const (
@@ -61,7 +64,6 @@ func NewStorage(basePath string, hostname string, timeout time.Duration) (*Stora
 	if f, err := os.Stat(basePath); os.IsNotExist(err) || !f.IsDir() {
 		return nil, fmt.Errorf("invalid dir path: %s", basePath)
 	}
-
 	return &Storage{
 		BasePath: basePath,
 		Hostname: hostname,
@@ -69,18 +71,34 @@ func NewStorage(basePath string, hostname string, timeout time.Duration) (*Stora
 	}, nil
 }
 
-// ArtifactFor returns an artifact for the v1alpha1.Source.
-func (s *Storage) ArtifactFor(kind string, metadata metav1.Object, fileName, revision, checksum string) sourcev1.Artifact {
+// NewArtifactFor returns a new v1alpha1.Artifact.
+func (s *Storage) NewArtifactFor(kind string, metadata metav1.Object, revision, fileName string) sourcev1.Artifact {
 	path := sourcev1.ArtifactPath(kind, metadata.GetNamespace(), metadata.GetName(), fileName)
-	url := fmt.Sprintf("http://%s/%s", s.Hostname, path)
-
-	return sourcev1.Artifact{
-		Path:           path,
-		URL:            url,
-		Revision:       revision,
-		Checksum:       checksum,
-		LastUpdateTime: metav1.Now(),
+	artifact := sourcev1.Artifact{
+		Path:     path,
+		Revision: revision,
 	}
+	s.SetArtifactURL(&artifact)
+	return artifact
+}
+
+// SetArtifactURL sets the URL on the given v1alpha1.Artifact.
+func (s Storage) SetArtifactURL(artifact *sourcev1.Artifact) {
+	if artifact.Path == "" {
+		return
+	}
+	artifact.URL = fmt.Sprintf("http://%s/%s", s.Hostname, artifact.Path)
+}
+
+// SetHostname sets the hostname of the given URL string to the current Storage.Hostname
+// and returns the result.
+func (s Storage) SetHostname(URL string) string {
+	u, err := url.Parse(URL)
+	if err != nil {
+		return ""
+	}
+	u.Host = s.Hostname
+	return u.String()
 }
 
 // MkdirAll calls os.MkdirAll for the given v1alpha1.Artifact base dir.
@@ -95,7 +113,8 @@ func (s *Storage) RemoveAll(artifact sourcev1.Artifact) error {
 	return os.RemoveAll(dir)
 }
 
-// RemoveAllButCurrent removes all files for the given artifact base dir excluding the current one
+// RemoveAllButCurrent removes all files for the given v1alpha1.Artifact base dir,
+// excluding the current one.
 func (s *Storage) RemoveAllButCurrent(artifact sourcev1.Artifact) error {
 	localPath := s.LocalPath(artifact)
 	dir := filepath.Dir(localPath)
@@ -120,8 +139,8 @@ func (s *Storage) RemoveAllButCurrent(artifact sourcev1.Artifact) error {
 	return nil
 }
 
-// ArtifactExist returns a boolean indicating whether the artifact exists in storage and is a
-// regular file.
+// ArtifactExist returns a boolean indicating whether the v1alpha1.Artifact exists in storage
+// and is a regular file.
 func (s *Storage) ArtifactExist(artifact sourcev1.Artifact) bool {
 	fi, err := os.Lstat(s.LocalPath(artifact))
 	if err != nil {
@@ -130,33 +149,74 @@ func (s *Storage) ArtifactExist(artifact sourcev1.Artifact) bool {
 	return fi.Mode().IsRegular()
 }
 
-// Archive creates a tar.gz to the artifact path from the given dir excluding any VCS specific
-// files and directories, or any of the excludes defined in the excludeFiles.
-func (s *Storage) Archive(artifact sourcev1.Artifact, dir string, spec sourcev1.GitRepositorySpec) error {
-	if _, err := os.Stat(dir); err != nil {
-		return err
+// Archive atomically archives the given directory as a tarball to the given v1alpha1.Artifact
+// path, excluding any VCS specific files and directories, or any of the excludes defined in
+// the excludeFiles. If successful, it sets the checksum and last update time on the artifact.
+func (s *Storage) Archive(artifact *sourcev1.Artifact, dir string, spec sourcev1.GitRepositorySpec) (err error) {
+	if f, err := os.Stat(dir); os.IsNotExist(err) || !f.IsDir() {
+		return fmt.Errorf("invalid dir path: %s", dir)
 	}
 
 	ps, err := loadExcludePatterns(dir, spec)
 	if err != nil {
 		return err
 	}
-
 	matcher := gitignore.NewMatcher(ps)
 
-	gzFile, err := os.Create(s.LocalPath(artifact))
+	localPath := s.LocalPath(*artifact)
+	tf, err := ioutil.TempFile(filepath.Split(localPath))
 	if err != nil {
 		return err
 	}
-	defer gzFile.Close()
+	tmpName := tf.Name()
+	defer func() {
+		if err != nil {
+			os.Remove(tmpName)
+		}
+	}()
 
-	gw := gzip.NewWriter(gzFile)
-	defer gw.Close()
+	h := newHash()
+	mw := io.MultiWriter(h, tf)
 
+	gw := gzip.NewWriter(mw)
 	tw := tar.NewWriter(gw)
-	defer tw.Close()
+	if err := writeToArchiveExcludeMatches(dir, matcher, tw); err != nil {
+		tw.Close()
+		gw.Close()
+		tf.Close()
+		return err
+	}
 
-	return filepath.Walk(dir, func(p string, fi os.FileInfo, err error) error {
+	if err := tw.Close(); err != nil {
+		gw.Close()
+		tf.Close()
+		return err
+	}
+	if err := gw.Close(); err != nil {
+		tf.Close()
+		return err
+	}
+	if err := tf.Close(); err != nil {
+		return err
+	}
+
+	if err := os.Chmod(tmpName, 0644); err != nil {
+		return err
+	}
+
+	if err := fs.RenameWithFallback(tmpName, localPath); err != nil {
+		return err
+	}
+
+	artifact.Checksum = fmt.Sprintf("%x", h.Sum(nil))
+	artifact.LastUpdateTime = metav1.Now()
+	return nil
+}
+
+// writeToArchiveExcludeMatches walks over the given dir and writes any regular file that does
+// not match the given gitignore.Matcher.
+func writeToArchiveExcludeMatches(dir string, matcher gitignore.Matcher, writer *tar.Writer) error {
+	fn := func(p string, fi os.FileInfo, err error) error {
 		if err != nil {
 			return err
 		}
@@ -187,36 +247,99 @@ func (s *Storage) Archive(artifact sourcev1.Artifact, dir string, spec sourcev1.
 		}
 		header.Name = relFilePath
 
-		if err := tw.WriteHeader(header); err != nil {
+		if err := writer.WriteHeader(header); err != nil {
 			return err
 		}
 
 		f, err := os.Open(p)
 		if err != nil {
+			f.Close()
 			return err
 		}
-		if _, err := io.Copy(tw, f); err != nil {
+		if _, err := io.Copy(writer, f); err != nil {
 			f.Close()
 			return err
 		}
 		return f.Close()
-	})
+	}
+	return filepath.Walk(dir, fn)
 }
 
-// WriteFile writes the given bytes to the artifact path if the checksum differs
-func (s *Storage) WriteFile(artifact sourcev1.Artifact, data []byte) error {
-	localPath := s.LocalPath(artifact)
-	sum := s.Checksum(data)
-	if file, err := os.Stat(localPath); !os.IsNotExist(err) && !file.IsDir() {
-		if fb, err := ioutil.ReadFile(localPath); err == nil && sum == s.Checksum(fb) {
-			return nil
+// AtomicWriteFile atomically writes the io.Reader contents to the v1alpha1.Artifact path.
+// If successful, it sets the checksum and last update time on the artifact.
+func (s *Storage) AtomicWriteFile(artifact *sourcev1.Artifact, reader io.Reader, mode os.FileMode) (err error) {
+	localPath := s.LocalPath(*artifact)
+	tf, err := ioutil.TempFile(filepath.Split(localPath))
+	if err != nil {
+		return err
+	}
+	tfName := tf.Name()
+	defer func() {
+		if err != nil {
+			os.Remove(tfName)
 		}
+	}()
+
+	h := newHash()
+	mw := io.MultiWriter(h, tf)
+
+	if _, err := io.Copy(mw, reader); err != nil {
+		tf.Close()
+		return err
+	}
+	if err := tf.Close(); err != nil {
+		return err
 	}
 
-	return ioutil.WriteFile(localPath, data, 0644)
+	if err := os.Chmod(tfName, mode); err != nil {
+		return err
+	}
+
+	if err := fs.RenameWithFallback(tfName, localPath); err != nil {
+		return err
+	}
+
+	artifact.Checksum = fmt.Sprintf("%x", h.Sum(nil))
+	artifact.LastUpdateTime = metav1.Now()
+	return nil
 }
 
-// Symlink creates or updates a symbolic link for the given artifact
+// Copy atomically copies the io.Reader contents to the v1alpha1.Artifact path.
+// If successful, it sets the checksum and last update time on the artifact.
+func (s *Storage) Copy(artifact *sourcev1.Artifact, reader io.Reader) (err error) {
+	localPath := s.LocalPath(*artifact)
+	tf, err := ioutil.TempFile(filepath.Split(localPath))
+	if err != nil {
+		return err
+	}
+	tfName := tf.Name()
+	defer func() {
+		if err != nil {
+			os.Remove(tfName)
+		}
+	}()
+
+	h := newHash()
+	mw := io.MultiWriter(h, tf)
+
+	if _, err := io.Copy(mw, reader); err != nil {
+		tf.Close()
+		return err
+	}
+	if err := tf.Close(); err != nil {
+		return err
+	}
+
+	if err := fs.RenameWithFallback(tfName, localPath); err != nil {
+		return err
+	}
+
+	artifact.Checksum = fmt.Sprintf("%x", h.Sum(nil))
+	artifact.LastUpdateTime = metav1.Now()
+	return nil
+}
+
+// Symlink creates or updates a symbolic link for the given v1alpha1.Artifact
 // and returns the URL for the symlink.
 func (s *Storage) Symlink(artifact sourcev1.Artifact, linkName string) (string, error) {
 	localPath := s.LocalPath(artifact)
@@ -236,17 +359,18 @@ func (s *Storage) Symlink(artifact sourcev1.Artifact, linkName string) (string,
 		return "", err
 	}
 
-	parts := strings.Split(artifact.URL, "/")
-	url := strings.Replace(artifact.URL, parts[len(parts)-1], linkName, 1)
+	url := fmt.Sprintf("http://%s/%s", s.Hostname, filepath.Join(filepath.Dir(artifact.Path), linkName))
 	return url, nil
 }
 
-// Checksum returns the SHA1 checksum for the given bytes as a string
-func (s *Storage) Checksum(b []byte) string {
-	return fmt.Sprintf("%x", sha1.Sum(b))
+// Checksum returns the SHA1 checksum for the data of the given io.Reader as a string.
+func (s *Storage) Checksum(reader io.Reader) string {
+	h := newHash()
+	_, _ = io.Copy(h, reader)
+	return fmt.Sprintf("%x", h.Sum(nil))
 }
 
-// Lock creates a file lock for the given artifact
+// Lock creates a file lock for the given v1alpha1.Artifact.
 func (s *Storage) Lock(artifact sourcev1.Artifact) (unlock func(), err error) {
 	lockFile := s.LocalPath(artifact) + ".lock"
 	mutex := lockedfile.MutexAt(lockFile)
@@ -262,6 +386,8 @@ func (s *Storage) LocalPath(artifact sourcev1.Artifact) string {
 	return filepath.Join(s.BasePath, artifact.Path)
 }
 
+// getPatterns collects ignore patterns from the given reader and returns them
+// as a gitignore.Pattern slice.
 func getPatterns(reader io.Reader, path []string) []gitignore.Pattern {
 	var ps []gitignore.Pattern
 	scanner := bufio.NewScanner(reader)
@@ -303,3 +429,8 @@ func loadExcludePatterns(dir string, spec sourcev1.GitRepositorySpec) ([]gitigno
 
 	return ps, nil
 }
+
+// newHash returns a new SHA1 hash.
+func newHash() hash.Hash {
+	return sha1.New()
+}
diff --git a/controllers/storage_test.go b/controllers/storage_test.go
index 307f8676..a90a7229 100644
--- a/controllers/storage_test.go
+++ b/controllers/storage_test.go
@@ -159,7 +159,7 @@ func createArchive(t *testing.T, storage *Storage, filenames []string, sourceIgn
 		t.Fatalf("artifact directory creation failed: %v", err)
 	}
 
-	if err := storage.Archive(artifact, gitDir, spec); err != nil {
+	if err := storage.Archive(&artifact, gitDir, spec); err != nil {
 		t.Fatalf("archiving failed: %v", err)
 	}
 
diff --git a/docs/api/source.md b/docs/api/source.md
index b7294757..49c6bfd0 100644
--- a/docs/api/source.md
+++ b/docs/api/source.md
@@ -744,6 +744,18 @@ are.</p>
 <tbody>
 <tr>
 <td>
+<code>observedGeneration</code><br>
+<em>
+int64
+</em>
+</td>
+<td>
+<em>(Optional)</em>
+<p>ObservedGeneration is the last observed generation.</p>
+</td>
+</tr>
+<tr>
+<td>
 <code>conditions</code><br>
 <em>
 <a href="#source.toolkit.fluxcd.io/v1alpha1.SourceCondition">
@@ -753,6 +765,7 @@ are.</p>
 </td>
 <td>
 <em>(Optional)</em>
+<p>Conditions holds the conditions for the GitRepository.</p>
 </td>
 </tr>
 <tr>
@@ -921,6 +934,18 @@ Kubernetes meta/v1.Duration
 <tbody>
 <tr>
 <td>
+<code>observedGeneration</code><br>
+<em>
+int64
+</em>
+</td>
+<td>
+<em>(Optional)</em>
+<p>ObservedGeneration is the last observed generation.</p>
+</td>
+</tr>
+<tr>
+<td>
 <code>conditions</code><br>
 <em>
 <a href="#source.toolkit.fluxcd.io/v1alpha1.SourceCondition">
@@ -930,6 +955,7 @@ Kubernetes meta/v1.Duration
 </td>
 <td>
 <em>(Optional)</em>
+<p>Conditions holds the conditions for the HelmChart.</p>
 </td>
 </tr>
 <tr>
@@ -1059,6 +1085,18 @@ Kubernetes meta/v1.Duration
 <tbody>
 <tr>
 <td>
+<code>observedGeneration</code><br>
+<em>
+int64
+</em>
+</td>
+<td>
+<em>(Optional)</em>
+<p>ObservedGeneration is the last observed generation.</p>
+</td>
+</tr>
+<tr>
+<td>
 <code>conditions</code><br>
 <em>
 <a href="#source.toolkit.fluxcd.io/v1alpha1.SourceCondition">
@@ -1068,6 +1106,7 @@ Kubernetes meta/v1.Duration
 </td>
 <td>
 <em>(Optional)</em>
+<p>Conditions holds the conditions for the HelmRepository.</p>
 </td>
 </tr>
 <tr>
diff --git a/go.mod b/go.mod
index 171657c2..18c7f7a8 100644
--- a/go.mod
+++ b/go.mod
@@ -10,7 +10,7 @@ require (
 	github.com/fluxcd/pkg/helmtestserver v0.0.1
 	github.com/fluxcd/pkg/lockedfile v0.0.5
 	github.com/fluxcd/pkg/recorder v0.0.6
-	github.com/fluxcd/pkg/runtime v0.0.0-20200909163337-e7e634246495
+	github.com/fluxcd/pkg/runtime v0.0.1
 	github.com/fluxcd/pkg/ssh v0.0.5
 	github.com/fluxcd/pkg/untar v0.0.5
 	github.com/fluxcd/source-controller/api v0.0.14
diff --git a/go.sum b/go.sum
index 87881d05..9ef50f4a 100644
--- a/go.sum
+++ b/go.sum
@@ -210,8 +210,8 @@ github.com/fluxcd/pkg/lockedfile v0.0.5 h1:C3T8wfdff1UY1bvplmCkGOLrdMWJHO8Q8+tdl
 github.com/fluxcd/pkg/lockedfile v0.0.5/go.mod h1:uAtPUBId6a2RqO84MTH5HKGX0SbM1kNW3Wr/FhYyDVA=
 github.com/fluxcd/pkg/recorder v0.0.6 h1:me/n8syeeGXz50OXoPX3jgIj9AtinvhHdKT9Dy+MbHs=
 github.com/fluxcd/pkg/recorder v0.0.6/go.mod h1:IfQxfVRSNsWs3B0Yp5B6ObEWwKHILlAx8N7XkoDdhFg=
-github.com/fluxcd/pkg/runtime v0.0.0-20200909163337-e7e634246495 h1:zhtLz8iRtJWK+jKq9vi9Si4QbcAC2KvQZpQ55DRzLsU=
-github.com/fluxcd/pkg/runtime v0.0.0-20200909163337-e7e634246495/go.mod h1:cU1t0+Ld39pZjMyrrHukw1E++OZFNHxG2qAExfDWQ34=
+github.com/fluxcd/pkg/runtime v0.0.1 h1:h8jztHVF9UMGD7XBQSfXDdw80bpT6BOkd0xe4kknPL0=
+github.com/fluxcd/pkg/runtime v0.0.1/go.mod h1:cU1t0+Ld39pZjMyrrHukw1E++OZFNHxG2qAExfDWQ34=
 github.com/fluxcd/pkg/ssh v0.0.5 h1:rnbFZ7voy2JBlUfMbfyqArX2FYaLNpDhccGFC3qW83A=
 github.com/fluxcd/pkg/ssh v0.0.5/go.mod h1:7jXPdXZpc0ttMNz2kD9QuMi3RNn/e0DOFbj0Tij/+Hs=
 github.com/fluxcd/pkg/testserver v0.0.2 h1:SoaMtO9cE5p/wl2zkGudzflnEHd9mk68CGjZOo7w0Uk=
diff --git a/internal/fs/LICENSE b/internal/fs/LICENSE
new file mode 100644
index 00000000..a2dd15fa
--- /dev/null
+++ b/internal/fs/LICENSE
@@ -0,0 +1,27 @@
+Copyright (c) 2014 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/internal/fs/fs.go b/internal/fs/fs.go
new file mode 100644
index 00000000..c8ece049
--- /dev/null
+++ b/internal/fs/fs.go
@@ -0,0 +1,346 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fs
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"runtime"
+	"syscall"
+)
+
+// RenameWithFallback attempts to rename a file or directory, but falls back to
+// copying in the event of a cross-device link error. If the fallback copy
+// succeeds, src is still removed, emulating normal rename behavior.
+func RenameWithFallback(src, dst string) error {
+	_, err := os.Stat(src)
+	if err != nil {
+		return fmt.Errorf("cannot stat %s: %w", src, err)
+	}
+
+	err = os.Rename(src, dst)
+	if err == nil {
+		return nil
+	}
+
+	return renameFallback(err, src, dst)
+}
+
+// renameByCopy attempts to rename a file or directory by copying it to the
+// destination and then removing the src thus emulating the rename behavior.
+func renameByCopy(src, dst string) error {
+	var cerr error
+	if dir, _ := IsDir(src); dir {
+		cerr = CopyDir(src, dst)
+		if cerr != nil {
+			cerr = fmt.Errorf("copying directory failed: %w", cerr)
+		}
+	} else {
+		cerr = copyFile(src, dst)
+		if cerr != nil {
+			cerr = fmt.Errorf("copying file failed: %w", cerr)
+		}
+	}
+
+	if cerr != nil {
+		return fmt.Errorf("rename fallback failed: cannot rename %s to %s: %w", src, dst, cerr)
+	}
+
+	if err := os.RemoveAll(src); err != nil {
+		return fmt.Errorf("cannot delete %s: %w", src, err)
+	}
+
+	return nil
+}
+
+var (
+	errSrcNotDir = errors.New("source is not a directory")
+	errDstExist  = errors.New("destination already exists")
+)
+
+// CopyDir recursively copies a directory tree, attempting to preserve permissions.
+// Source directory must exist, destination directory must *not* exist.
+func CopyDir(src, dst string) error {
+	src = filepath.Clean(src)
+	dst = filepath.Clean(dst)
+
+	// We use os.Lstat() here to ensure we don't fall in a loop where a symlink
+	// actually links to a one of its parent directories.
+	fi, err := os.Lstat(src)
+	if err != nil {
+		return err
+	}
+	if !fi.IsDir() {
+		return errSrcNotDir
+	}
+
+	_, err = os.Stat(dst)
+	if err != nil && !os.IsNotExist(err) {
+		return err
+	}
+	if err == nil {
+		return errDstExist
+	}
+
+	if err = os.MkdirAll(dst, fi.Mode()); err != nil {
+		return fmt.Errorf("cannot mkdir %s: %w", dst, err)
+	}
+
+	entries, err := ioutil.ReadDir(src)
+	if err != nil {
+		return fmt.Errorf("cannot read directory %s: %w", dst, err)
+	}
+
+	for _, entry := range entries {
+		srcPath := filepath.Join(src, entry.Name())
+		dstPath := filepath.Join(dst, entry.Name())
+
+		if entry.IsDir() {
+			if err = CopyDir(srcPath, dstPath); err != nil {
+				return fmt.Errorf("copying directory failed: %w", err)
+			}
+		} else {
+			// This will include symlinks, which is what we want when
+			// copying things.
+			if err = copyFile(srcPath, dstPath); err != nil {
+				return fmt.Errorf("copying file failed: %w", err)
+			}
+		}
+	}
+
+	return nil
+}
+
+// copyFile copies the contents of the file named src to the file named
+// by dst. The file will be created if it does not already exist. If the
+// destination file exists, all its contents will be replaced by the contents
+// of the source file. The file mode will be copied from the source.
+func copyFile(src, dst string) (err error) {
+	if sym, err := IsSymlink(src); err != nil {
+		return fmt.Errorf("symlink check failed: %w", err)
+	} else if sym {
+		if err := cloneSymlink(src, dst); err != nil {
+			if runtime.GOOS == "windows" {
+				// If cloning the symlink fails on Windows because the user
+				// does not have the required privileges, ignore the error and
+				// fall back to copying the file contents.
+				//
+				// ERROR_PRIVILEGE_NOT_HELD is 1314 (0x522):
+				// https://msdn.microsoft.com/en-us/library/windows/desktop/ms681385(v=vs.85).aspx
+				if lerr, ok := err.(*os.LinkError); ok && lerr.Err != syscall.Errno(1314) {
+					return err
+				}
+			} else {
+				return err
+			}
+		} else {
+			return nil
+		}
+	}
+
+	in, err := os.Open(src)
+	if err != nil {
+		return
+	}
+	defer in.Close()
+
+	out, err := os.Create(dst)
+	if err != nil {
+		return
+	}
+
+	if _, err = io.Copy(out, in); err != nil {
+		out.Close()
+		return
+	}
+
+	// Check for write errors on Close
+	if err = out.Close(); err != nil {
+		return
+	}
+
+	si, err := os.Stat(src)
+	if err != nil {
+		return
+	}
+
+	// Temporary fix for Go < 1.9
+	//
+	// See: https://github.com/golang/dep/issues/774
+	// and https://github.com/golang/go/issues/20829
+	if runtime.GOOS == "windows" {
+		dst = fixLongPath(dst)
+	}
+	err = os.Chmod(dst, si.Mode())
+
+	return
+}
+
+// cloneSymlink will create a new symlink that points to the resolved path of sl.
+// If sl is a relative symlink, dst will also be a relative symlink.
+func cloneSymlink(sl, dst string) error {
+	resolved, err := os.Readlink(sl)
+	if err != nil {
+		return err
+	}
+
+	return os.Symlink(resolved, dst)
+}
+
+// IsDir determines is the path given is a directory or not.
+func IsDir(name string) (bool, error) {
+	fi, err := os.Stat(name)
+	if err != nil {
+		return false, err
+	}
+	if !fi.IsDir() {
+		return false, fmt.Errorf("%q is not a directory", name)
+	}
+	return true, nil
+}
+
+// IsSymlink determines if the given path is a symbolic link.
+func IsSymlink(path string) (bool, error) {
+	l, err := os.Lstat(path)
+	if err != nil {
+		return false, err
+	}
+
+	return l.Mode()&os.ModeSymlink == os.ModeSymlink, nil
+}
+
+// fixLongPath returns the extended-length (\\?\-prefixed) form of
+// path when needed, in order to avoid the default 260 character file
+// path limit imposed by Windows. If path is not easily converted to
+// the extended-length form (for example, if path is a relative path
+// or contains .. elements), or is short enough, fixLongPath returns
+// path unmodified.
+//
+// See https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx#maxpath
+func fixLongPath(path string) string {
+	// Do nothing (and don't allocate) if the path is "short".
+	// Empirically (at least on the Windows Server 2013 builder),
+	// the kernel is arbitrarily okay with < 248 bytes. That
+	// matches what the docs above say:
+	// "When using an API to create a directory, the specified
+	// path cannot be so long that you cannot append an 8.3 file
+	// name (that is, the directory name cannot exceed MAX_PATH
+	// minus 12)." Since MAX_PATH is 260, 260 - 12 = 248.
+	//
+	// The MSDN docs appear to say that a normal path that is 248 bytes long
+	// will work; empirically the path must be less then 248 bytes long.
+	if len(path) < 248 {
+		// Don't fix. (This is how Go 1.7 and earlier worked,
+		// not automatically generating the \\?\ form)
+		return path
+	}
+
+	// The extended form begins with \\?\, as in
+	// \\?\c:\windows\foo.txt or \\?\UNC\server\share\foo.txt.
+	// The extended form disables evaluation of . and .. path
+	// elements and disables the interpretation of / as equivalent
+	// to \. The conversion here rewrites / to \ and elides
+	// . elements as well as trailing or duplicate separators. For
+	// simplicity it avoids the conversion entirely for relative
+	// paths or paths containing .. elements. For now,
+	// \\server\share paths are not converted to
+	// \\?\UNC\server\share paths because the rules for doing so
+	// are less well-specified.
+	if len(path) >= 2 && path[:2] == `\\` {
+		// Don't canonicalize UNC paths.
+		return path
+	}
+	if !isAbs(path) {
+		// Relative path
+		return path
+	}
+
+	const prefix = `\\?`
+
+	pathbuf := make([]byte, len(prefix)+len(path)+len(`\`))
+	copy(pathbuf, prefix)
+	n := len(path)
+	r, w := 0, len(prefix)
+	for r < n {
+		switch {
+		case os.IsPathSeparator(path[r]):
+			// empty block
+			r++
+		case path[r] == '.' && (r+1 == n || os.IsPathSeparator(path[r+1])):
+			// /./
+			r++
+		case r+1 < n && path[r] == '.' && path[r+1] == '.' && (r+2 == n || os.IsPathSeparator(path[r+2])):
+			// /../ is currently unhandled
+			return path
+		default:
+			pathbuf[w] = '\\'
+			w++
+			for ; r < n && !os.IsPathSeparator(path[r]); r++ {
+				pathbuf[w] = path[r]
+				w++
+			}
+		}
+	}
+	// A drive's root directory needs a trailing \
+	if w == len(`\\?\c:`) {
+		pathbuf[w] = '\\'
+		w++
+	}
+	return string(pathbuf[:w])
+}
+
+func isAbs(path string) (b bool) {
+	v := volumeName(path)
+	if v == "" {
+		return false
+	}
+	path = path[len(v):]
+	if path == "" {
+		return false
+	}
+	return os.IsPathSeparator(path[0])
+}
+
+func volumeName(path string) (v string) {
+	if len(path) < 2 {
+		return ""
+	}
+	// with drive letter
+	c := path[0]
+	if path[1] == ':' &&
+		('0' <= c && c <= '9' || 'a' <= c && c <= 'z' ||
+			'A' <= c && c <= 'Z') {
+		return path[:2]
+	}
+	// is it UNC
+	if l := len(path); l >= 5 && os.IsPathSeparator(path[0]) && os.IsPathSeparator(path[1]) &&
+		!os.IsPathSeparator(path[2]) && path[2] != '.' {
+		// first, leading `\\` and next shouldn't be `\`. its server name.
+		for n := 3; n < l-1; n++ {
+			// second, next '\' shouldn't be repeated.
+			if os.IsPathSeparator(path[n]) {
+				n++
+				// third, following something characters. its share name.
+				if !os.IsPathSeparator(path[n]) {
+					if path[n] == '.' {
+						break
+					}
+					for ; n < l; n++ {
+						if os.IsPathSeparator(path[n]) {
+							break
+						}
+					}
+					return path[:n]
+				}
+				break
+			}
+		}
+	}
+	return ""
+}
diff --git a/internal/fs/fs_test.go b/internal/fs/fs_test.go
new file mode 100644
index 00000000..eba87eba
--- /dev/null
+++ b/internal/fs/fs_test.go
@@ -0,0 +1,657 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fs
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"sync"
+	"testing"
+)
+
+var (
+	mu sync.Mutex
+)
+
+func TestRenameWithFallback(t *testing.T) {
+	dir, err := ioutil.TempDir("", "dep")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(dir)
+
+	if err = RenameWithFallback(filepath.Join(dir, "does_not_exists"), filepath.Join(dir, "dst")); err == nil {
+		t.Fatal("expected an error for non existing file, but got nil")
+	}
+
+	srcpath := filepath.Join(dir, "src")
+
+	if srcf, err := os.Create(srcpath); err != nil {
+		t.Fatal(err)
+	} else {
+		srcf.Close()
+	}
+
+	if err = RenameWithFallback(srcpath, filepath.Join(dir, "dst")); err != nil {
+		t.Fatal(err)
+	}
+
+	srcpath = filepath.Join(dir, "a")
+	if err = os.MkdirAll(srcpath, 0777); err != nil {
+		t.Fatal(err)
+	}
+
+	dstpath := filepath.Join(dir, "b")
+	if err = os.MkdirAll(dstpath, 0777); err != nil {
+		t.Fatal(err)
+	}
+
+	if err = RenameWithFallback(srcpath, dstpath); err == nil {
+		t.Fatal("expected an error if dst is an existing directory, but got nil")
+	}
+}
+
+func TestCopyDir(t *testing.T) {
+	dir, err := ioutil.TempDir("", "dep")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(dir)
+
+	srcdir := filepath.Join(dir, "src")
+	if err := os.MkdirAll(srcdir, 0755); err != nil {
+		t.Fatal(err)
+	}
+
+	files := []struct {
+		path     string
+		contents string
+		fi       os.FileInfo
+	}{
+		{path: "myfile", contents: "hello world"},
+		{path: filepath.Join("subdir", "file"), contents: "subdir file"},
+	}
+
+	// Create structure indicated in 'files'
+	for i, file := range files {
+		fn := filepath.Join(srcdir, file.path)
+		dn := filepath.Dir(fn)
+		if err = os.MkdirAll(dn, 0755); err != nil {
+			t.Fatal(err)
+		}
+
+		fh, err := os.Create(fn)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if _, err = fh.Write([]byte(file.contents)); err != nil {
+			t.Fatal(err)
+		}
+		fh.Close()
+
+		files[i].fi, err = os.Stat(fn)
+		if err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	destdir := filepath.Join(dir, "dest")
+	if err := CopyDir(srcdir, destdir); err != nil {
+		t.Fatal(err)
+	}
+
+	// Compare copy against structure indicated in 'files'
+	for _, file := range files {
+		fn := filepath.Join(srcdir, file.path)
+		dn := filepath.Dir(fn)
+		dirOK, err := IsDir(dn)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if !dirOK {
+			t.Fatalf("expected %s to be a directory", dn)
+		}
+
+		got, err := ioutil.ReadFile(fn)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if file.contents != string(got) {
+			t.Fatalf("expected: %s, got: %s", file.contents, string(got))
+		}
+
+		gotinfo, err := os.Stat(fn)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if file.fi.Mode() != gotinfo.Mode() {
+			t.Fatalf("expected %s: %#v\n to be the same mode as %s: %#v",
+				file.path, file.fi.Mode(), fn, gotinfo.Mode())
+		}
+	}
+}
+
+func TestCopyDirFail_SrcInaccessible(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		// XXX: setting permissions works differently in
+		// Microsoft Windows. Skipping this this until a
+		// compatible implementation is provided.
+		t.Skip("skipping on windows")
+	}
+
+	var srcdir, dstdir string
+
+	cleanup := setupInaccessibleDir(t, func(dir string) error {
+		srcdir = filepath.Join(dir, "src")
+		return os.MkdirAll(srcdir, 0755)
+	})
+	defer cleanup()
+
+	dir, err := ioutil.TempDir("", "dep")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(dir)
+
+	dstdir = filepath.Join(dir, "dst")
+	if err = CopyDir(srcdir, dstdir); err == nil {
+		t.Fatalf("expected error for CopyDir(%s, %s), got none", srcdir, dstdir)
+	}
+}
+
+func TestCopyDirFail_DstInaccessible(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		// XXX: setting permissions works differently in
+		// Microsoft Windows. Skipping this this until a
+		// compatible implementation is provided.
+		t.Skip("skipping on windows")
+	}
+
+	var srcdir, dstdir string
+
+	dir, err := ioutil.TempDir("", "dep")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(dir)
+
+	srcdir = filepath.Join(dir, "src")
+	if err = os.MkdirAll(srcdir, 0755); err != nil {
+		t.Fatal(err)
+	}
+
+	cleanup := setupInaccessibleDir(t, func(dir string) error {
+		dstdir = filepath.Join(dir, "dst")
+		return nil
+	})
+	defer cleanup()
+
+	if err := CopyDir(srcdir, dstdir); err == nil {
+		t.Fatalf("expected error for CopyDir(%s, %s), got none", srcdir, dstdir)
+	}
+}
+
+func TestCopyDirFail_SrcIsNotDir(t *testing.T) {
+	var srcdir, dstdir string
+
+	dir, err := ioutil.TempDir("", "dep")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(dir)
+
+	srcdir = filepath.Join(dir, "src")
+	if _, err = os.Create(srcdir); err != nil {
+		t.Fatal(err)
+	}
+
+	dstdir = filepath.Join(dir, "dst")
+
+	if err = CopyDir(srcdir, dstdir); err == nil {
+		t.Fatalf("expected error for CopyDir(%s, %s), got none", srcdir, dstdir)
+	}
+
+	if err != errSrcNotDir {
+		t.Fatalf("expected %v error for CopyDir(%s, %s), got %s", errSrcNotDir, srcdir, dstdir, err)
+	}
+
+}
+
+func TestCopyDirFail_DstExists(t *testing.T) {
+	var srcdir, dstdir string
+
+	dir, err := ioutil.TempDir("", "dep")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(dir)
+
+	srcdir = filepath.Join(dir, "src")
+	if err = os.MkdirAll(srcdir, 0755); err != nil {
+		t.Fatal(err)
+	}
+
+	dstdir = filepath.Join(dir, "dst")
+	if err = os.MkdirAll(dstdir, 0755); err != nil {
+		t.Fatal(err)
+	}
+
+	if err = CopyDir(srcdir, dstdir); err == nil {
+		t.Fatalf("expected error for CopyDir(%s, %s), got none", srcdir, dstdir)
+	}
+
+	if err != errDstExist {
+		t.Fatalf("expected %v error for CopyDir(%s, %s), got %s", errDstExist, srcdir, dstdir, err)
+	}
+}
+
+func TestCopyDirFailOpen(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		// XXX: setting permissions works differently in
+		// Microsoft Windows. os.Chmod(..., 0222) below is not
+		// enough for the file to be readonly, and os.Chmod(...,
+		// 0000) returns an invalid argument error. Skipping
+		// this this until a compatible implementation is
+		// provided.
+		t.Skip("skipping on windows")
+	}
+
+	var srcdir, dstdir string
+
+	dir, err := ioutil.TempDir("", "dep")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(dir)
+
+	srcdir = filepath.Join(dir, "src")
+	if err = os.MkdirAll(srcdir, 0755); err != nil {
+		t.Fatal(err)
+	}
+
+	srcfn := filepath.Join(srcdir, "file")
+	srcf, err := os.Create(srcfn)
+	if err != nil {
+		t.Fatal(err)
+	}
+	srcf.Close()
+
+	// setup source file so that it cannot be read
+	if err = os.Chmod(srcfn, 0222); err != nil {
+		t.Fatal(err)
+	}
+
+	dstdir = filepath.Join(dir, "dst")
+
+	if err = CopyDir(srcdir, dstdir); err == nil {
+		t.Fatalf("expected error for CopyDir(%s, %s), got none", srcdir, dstdir)
+	}
+}
+
+func TestCopyFile(t *testing.T) {
+	dir, err := ioutil.TempDir("", "dep")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(dir)
+
+	srcf, err := os.Create(filepath.Join(dir, "srcfile"))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	want := "hello world"
+	if _, err := srcf.Write([]byte(want)); err != nil {
+		t.Fatal(err)
+	}
+	srcf.Close()
+
+	destf := filepath.Join(dir, "destf")
+	if err := copyFile(srcf.Name(), destf); err != nil {
+		t.Fatal(err)
+	}
+
+	got, err := ioutil.ReadFile(destf)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if want != string(got) {
+		t.Fatalf("expected: %s, got: %s", want, string(got))
+	}
+
+	wantinfo, err := os.Stat(srcf.Name())
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	gotinfo, err := os.Stat(destf)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if wantinfo.Mode() != gotinfo.Mode() {
+		t.Fatalf("expected %s: %#v\n to be the same mode as %s: %#v", srcf.Name(), wantinfo.Mode(), destf, gotinfo.Mode())
+	}
+}
+
+func TestCopyFileSymlink(t *testing.T) {
+	dir, err := ioutil.TempDir("", "dep")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer cleanUpDir(dir)
+
+	testcases := map[string]string{
+		filepath.Join("./testdata/symlinks/file-symlink"):         filepath.Join(dir, "dst-file"),
+		filepath.Join("./testdata/symlinks/windows-file-symlink"): filepath.Join(dir, "windows-dst-file"),
+		filepath.Join("./testdata/symlinks/invalid-symlink"):      filepath.Join(dir, "invalid-symlink"),
+	}
+
+	for symlink, dst := range testcases {
+		t.Run(symlink, func(t *testing.T) {
+			var err error
+			if err = copyFile(symlink, dst); err != nil {
+				t.Fatalf("failed to copy symlink: %s", err)
+			}
+
+			var want, got string
+
+			if runtime.GOOS == "windows" {
+				// Creating symlinks on Windows require an additional permission
+				// regular users aren't granted usually. So we copy the file
+				// content as a fall back instead of creating a real symlink.
+				srcb, err := ioutil.ReadFile(symlink)
+				if err != nil {
+					t.Fatalf("%+v", err)
+				}
+				dstb, err := ioutil.ReadFile(dst)
+				if err != nil {
+					t.Fatalf("%+v", err)
+				}
+
+				want = string(srcb)
+				got = string(dstb)
+			} else {
+				want, err = os.Readlink(symlink)
+				if err != nil {
+					t.Fatalf("%+v", err)
+				}
+
+				got, err = os.Readlink(dst)
+				if err != nil {
+					t.Fatalf("could not resolve symlink: %s", err)
+				}
+			}
+
+			if want != got {
+				t.Fatalf("resolved path is incorrect. expected %s, got %s", want, got)
+			}
+		})
+	}
+}
+
+func TestCopyFileLongFilePath(t *testing.T) {
+	if runtime.GOOS != "windows" {
+		// We want to ensure the temporary fix actually fixes the issue with
+		// os.Chmod and long file paths. This is only applicable on Windows.
+		t.Skip("skipping on non-windows")
+	}
+
+	dir, err := ioutil.TempDir("", "dep")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer cleanUpDir(dir)
+
+	// Create a directory with a long-enough path name to cause the bug in #774.
+	dirName := ""
+	for len(dir+string(os.PathSeparator)+dirName) <= 300 {
+		dirName += "directory"
+	}
+
+	fullPath := filepath.Join(dir, dirName, string(os.PathSeparator))
+	if err := os.MkdirAll(fullPath, 0755); err != nil && !os.IsExist(err) {
+		t.Fatalf("%+v", fmt.Errorf("unable to create temp directory: %s", fullPath))
+	}
+
+	err = ioutil.WriteFile(fullPath+"src", []byte(nil), 0644)
+	if err != nil {
+		t.Fatalf("%+v", err)
+	}
+
+	err = copyFile(fullPath+"src", fullPath+"dst")
+	if err != nil {
+		t.Fatalf("unexpected error while copying file: %v", err)
+	}
+}
+
+// C:\Users\appveyor\AppData\Local\Temp\1\gotest639065787\dir4567890\dir4567890\dir4567890\dir4567890\dir4567890\dir4567890\dir4567890\dir4567890\dir4567890\dir4567890\dir4567890\dir4567890\dir4567890\dir4567890\dir4567890\dir4567890\dir4567890\dir4567890\dir4567890\dir4567890\dir4567890\dir4567890\dir4567890
+
+func TestCopyFileFail(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		// XXX: setting permissions works differently in
+		// Microsoft Windows. Skipping this this until a
+		// compatible implementation is provided.
+		t.Skip("skipping on windows")
+	}
+
+	dir, err := ioutil.TempDir("", "dep")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(dir)
+
+	srcf, err := os.Create(filepath.Join(dir, "srcfile"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	srcf.Close()
+
+	var dstdir string
+
+	cleanup := setupInaccessibleDir(t, func(dir string) error {
+		dstdir = filepath.Join(dir, "dir")
+		return os.Mkdir(dstdir, 0777)
+	})
+	defer cleanup()
+
+	fn := filepath.Join(dstdir, "file")
+	if err := copyFile(srcf.Name(), fn); err == nil {
+		t.Fatalf("expected error for %s, got none", fn)
+	}
+}
+
+// setupInaccessibleDir creates a temporary location with a single
+// directory in it, in such a way that that directory is not accessible
+// after this function returns.
+//
+// op is called with the directory as argument, so that it can create
+// files or other test artifacts.
+//
+// If setupInaccessibleDir fails in its preparation, or op fails, t.Fatal
+// will be invoked.
+//
+// This function returns a cleanup function that removes all the temporary
+// files this function creates. It is the caller's responsibility to call
+// this function before the test is done running, whether there's an error or not.
+func setupInaccessibleDir(t *testing.T, op func(dir string) error) func() {
+	dir, err := ioutil.TempDir("", "dep")
+	if err != nil {
+		t.Fatal(err)
+		return nil // keep compiler happy
+	}
+
+	subdir := filepath.Join(dir, "dir")
+
+	cleanup := func() {
+		if err := os.Chmod(subdir, 0777); err != nil {
+			t.Error(err)
+		}
+		if err := os.RemoveAll(dir); err != nil {
+			t.Error(err)
+		}
+	}
+
+	if err := os.Mkdir(subdir, 0777); err != nil {
+		cleanup()
+		t.Fatal(err)
+		return nil
+	}
+
+	if err := op(subdir); err != nil {
+		cleanup()
+		t.Fatal(err)
+		return nil
+	}
+
+	if err := os.Chmod(subdir, 0666); err != nil {
+		cleanup()
+		t.Fatal(err)
+		return nil
+	}
+
+	return cleanup
+}
+
+func TestIsDir(t *testing.T) {
+	wd, err := os.Getwd()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var dn string
+
+	cleanup := setupInaccessibleDir(t, func(dir string) error {
+		dn = filepath.Join(dir, "dir")
+		return os.Mkdir(dn, 0777)
+	})
+	defer cleanup()
+
+	tests := map[string]struct {
+		exists bool
+		err    bool
+	}{
+		wd:                            {true, false},
+		filepath.Join(wd, "testdata"): {true, false},
+		filepath.Join(wd, "main.go"):  {false, true},
+		filepath.Join(wd, "this_file_does_not_exist.thing"): {false, true},
+		dn: {false, true},
+	}
+
+	if runtime.GOOS == "windows" {
+		// This test doesn't work on Microsoft Windows because
+		// of the differences in how file permissions are
+		// implemented. For this to work, the directory where
+		// the directory exists should be inaccessible.
+		delete(tests, dn)
+	}
+
+	for f, want := range tests {
+		got, err := IsDir(f)
+		if err != nil && !want.err {
+			t.Fatalf("expected no error, got %v", err)
+		}
+
+		if got != want.exists {
+			t.Fatalf("expected %t for %s, got %t", want.exists, f, got)
+		}
+	}
+}
+
+func TestIsSymlink(t *testing.T) {
+	dir, err := ioutil.TempDir("", "dep")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(dir)
+
+	dirPath := filepath.Join(dir, "directory")
+	if err = os.MkdirAll(dirPath, 0777); err != nil {
+		t.Fatal(err)
+	}
+
+	filePath := filepath.Join(dir, "file")
+	f, err := os.Create(filePath)
+	if err != nil {
+		t.Fatal(err)
+	}
+	f.Close()
+
+	dirSymlink := filepath.Join(dir, "dirSymlink")
+	fileSymlink := filepath.Join(dir, "fileSymlink")
+
+	if err = os.Symlink(dirPath, dirSymlink); err != nil {
+		t.Fatal(err)
+	}
+	if err = os.Symlink(filePath, fileSymlink); err != nil {
+		t.Fatal(err)
+	}
+
+	var (
+		inaccessibleFile    string
+		inaccessibleSymlink string
+	)
+
+	cleanup := setupInaccessibleDir(t, func(dir string) error {
+		inaccessibleFile = filepath.Join(dir, "file")
+		if fh, err := os.Create(inaccessibleFile); err != nil {
+			return err
+		} else if err = fh.Close(); err != nil {
+			return err
+		}
+
+		inaccessibleSymlink = filepath.Join(dir, "symlink")
+		return os.Symlink(inaccessibleFile, inaccessibleSymlink)
+	})
+	defer cleanup()
+
+	tests := map[string]struct{ expected, err bool }{
+		dirPath:             {false, false},
+		filePath:            {false, false},
+		dirSymlink:          {true, false},
+		fileSymlink:         {true, false},
+		inaccessibleFile:    {false, true},
+		inaccessibleSymlink: {false, true},
+	}
+
+	if runtime.GOOS == "windows" {
+		// XXX: setting permissions works differently in Windows. Skipping
+		// these cases until a compatible implementation is provided.
+		delete(tests, inaccessibleFile)
+		delete(tests, inaccessibleSymlink)
+	}
+
+	for path, want := range tests {
+		got, err := IsSymlink(path)
+		if err != nil {
+			if !want.err {
+				t.Errorf("expected no error, got %v", err)
+			}
+		}
+
+		if got != want.expected {
+			t.Errorf("expected %t for %s, got %t", want.expected, path, got)
+		}
+	}
+}
+
+func cleanUpDir(dir string) {
+	if runtime.GOOS == "windows" {
+		mu.Lock()
+		exec.Command(`taskkill`, `/F`, `/IM`, `git.exe`).Run()
+		mu.Unlock()
+	}
+	if dir != "" {
+		os.RemoveAll(dir)
+	}
+}
diff --git a/internal/fs/rename.go b/internal/fs/rename.go
new file mode 100644
index 00000000..a1b4a411
--- /dev/null
+++ b/internal/fs/rename.go
@@ -0,0 +1,30 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !windows
+
+package fs
+
+import (
+	"fmt"
+	"os"
+	"syscall"
+)
+
+// renameFallback attempts to determine the appropriate fallback to failed rename
+// operation depending on the resulting error.
+func renameFallback(err error, src, dst string) error {
+	// Rename may fail if src and dst are on different devices; fall back to
+	// copy if we detect that case. syscall.EXDEV is the common name for the
+	// cross device link error which has varying output text across different
+	// operating systems.
+	terr, ok := err.(*os.LinkError)
+	if !ok {
+		return err
+	} else if terr.Err != syscall.EXDEV {
+		return fmt.Errorf("link error: cannot rename %s to %s: %w", src, dst, terr)
+	}
+
+	return renameByCopy(src, dst)
+}
diff --git a/internal/fs/rename_windows.go b/internal/fs/rename_windows.go
new file mode 100644
index 00000000..3b565057
--- /dev/null
+++ b/internal/fs/rename_windows.go
@@ -0,0 +1,41 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build windows
+
+package fs
+
+import (
+	"fmt"
+	"os"
+	"syscall"
+)
+
+// renameFallback attempts to determine the appropriate fallback to failed rename
+// operation depending on the resulting error.
+func renameFallback(err error, src, dst string) error {
+	// Rename may fail if src and dst are on different devices; fall back to
+	// copy if we detect that case. syscall.EXDEV is the common name for the
+	// cross device link error which has varying output text across different
+	// operating systems.
+	terr, ok := err.(*os.LinkError)
+	if !ok {
+		return err
+	}
+
+	if terr.Err != syscall.EXDEV {
+		// In windows it can drop down to an operating system call that
+		// returns an operating system error with a different number and
+		// message. Checking for that as a fall back.
+		noerr, ok := terr.Err.(syscall.Errno)
+
+		// 0x11 (ERROR_NOT_SAME_DEVICE) is the windows error.
+		// See https://msdn.microsoft.com/en-us/library/cc231199.aspx
+		if ok && noerr != 0x11 {
+			return fmt.Errorf("link error: cannot rename %s to %s: %w", src, dst, terr)
+		}
+	}
+
+	return renameByCopy(src, dst)
+}
diff --git a/internal/fs/testdata/symlinks/dir-symlink b/internal/fs/testdata/symlinks/dir-symlink
new file mode 120000
index 00000000..777ebd01
--- /dev/null
+++ b/internal/fs/testdata/symlinks/dir-symlink
@@ -0,0 +1 @@
+../../testdata
\ No newline at end of file
diff --git a/internal/fs/testdata/symlinks/file-symlink b/internal/fs/testdata/symlinks/file-symlink
new file mode 120000
index 00000000..4c52274d
--- /dev/null
+++ b/internal/fs/testdata/symlinks/file-symlink
@@ -0,0 +1 @@
+../test.file
\ No newline at end of file
diff --git a/internal/fs/testdata/symlinks/invalid-symlink b/internal/fs/testdata/symlinks/invalid-symlink
new file mode 120000
index 00000000..0edf4f30
--- /dev/null
+++ b/internal/fs/testdata/symlinks/invalid-symlink
@@ -0,0 +1 @@
+/non/existing/file
\ No newline at end of file
diff --git a/internal/fs/testdata/symlinks/windows-file-symlink b/internal/fs/testdata/symlinks/windows-file-symlink
new file mode 120000
index 00000000..af1d6c8f
--- /dev/null
+++ b/internal/fs/testdata/symlinks/windows-file-symlink
@@ -0,0 +1 @@
+C:/Users/ibrahim/go/src/github.com/golang/dep/internal/fs/testdata/test.file
\ No newline at end of file
diff --git a/internal/fs/testdata/test.file b/internal/fs/testdata/test.file
new file mode 100644
index 00000000..e69de29b