Prototype temporary directory

Signed-off-by: Jan Rodák <[email protected]>

Author: Honny1

drivers/overlay/overlay.go

@@ -34,6 +34,7 @@ import (
 	"github.com/containers/storage/pkg/mount"
 	"github.com/containers/storage/pkg/parsers"
 	"github.com/containers/storage/pkg/system"
+	"github.com/containers/storage/pkg/tempdir"
 	"github.com/containers/storage/pkg/unshare"
 	units "github.com/docker/go-units"
 	digest "github.com/opencontainers/go-digest"
@@ -136,6 +137,9 @@ type Driver struct {
 	stagingDirsLocks map[string]*lockfile.LockFile
 
 	supportsIDMappedMounts *bool
+
+	// This fled is read-only. Should be save to access without any locking.
+	tempDirectory *tempdir.TempDir
 }
 
 type additionalLayerStore struct {
@@ -458,6 +462,12 @@ func Init(home string, options graphdriver.Options) (graphdriver.Driver, error)
 		return nil, fmt.Errorf("storage option overlay.size and overlay.inodes only supported for backingFS XFS. Found %v", backingFs)
 	}
 
+	t, err := tempdir.NewTempDir(filepath.Join(d.homeDirForImageStore(), stagingDir))
+	if err != nil {
+		return nil, err
+	}
+	d.tempDirectory = t
+
 	logrus.Debugf("backingFs=%s, projectQuotaSupported=%v, useNativeDiff=%v, usingMetacopy=%v", backingFs, projectQuotaSupported, !d.useNaiveDiff(), d.usingMetacopy)
 
 	return d, nil
@@ -862,6 +872,9 @@ func (d *Driver) Metadata(id string) (map[string]string, error) {
 // the storage is being shutdown.  The only state created by the driver
 // is the bind mount on the home directory.
 func (d *Driver) Cleanup() error {
+	if err := d.tempDirectory.Cleanup(); err != nil {
+		return err
+	}
 	anyPresent := d.pruneStagingDirectories()
 	if anyPresent {
 		return nil
@@ -1313,16 +1326,17 @@ func (d *Driver) Remove(id string) error {
 	dir := d.dir(id)
 	lid, err := os.ReadFile(path.Join(dir, "link"))
 	if err == nil {
-		if err := os.RemoveAll(path.Join(d.home, linkDir, string(lid))); err != nil {
-			logrus.Debugf("Failed to remove link: %v", err)
+		if err := d.tempDirectory.Add(path.Join(d.home, linkDir, string(lid))); err != nil {
+			logrus.Debugf("Failed to Add to stage Directory link: %v", err)
 		}
 	}
 
 	d.releaseAdditionalLayerByID(id)
 
-	if err := system.EnsureRemoveAll(dir); err != nil && !os.IsNotExist(err) {
-		return err
+	if err := d.tempDirectory.Add(dir); err != nil {
+		return fmt.Errorf("failed to add to stage directory: %w", err)
 	}
+
 	if d.quotaCtl != nil {
 		d.quotaCtl.ClearQuota(dir)
 		if d.imageStore != "" {
@@ -1358,8 +1372,8 @@ func (d *Driver) recreateSymlinks() error {
 		// Check that for each layer, there's a link in "l" with the name in
 		// the layer's "link" file that points to the layer's "diff" directory.
 		for _, dir := range dirs {
-			// Skip over the linkDir and anything that is not a directory
-			if dir.Name() == linkDir || !dir.IsDir() {
+			// Skip over the linkDir and anything that is not a directory or tempDir
+			if dir.Name() == linkDir || !dir.IsDir() || dir.Name() == stagingDir { // Note for review: Not sure if skipping stagingDir is correct
 				continue
 			}
 			// Read the "link" file under each layer to get the name of the symlink

drivers/vfs/driver.go

@@ -17,6 +17,7 @@ import (
 	"github.com/containers/storage/pkg/idtools"
 	"github.com/containers/storage/pkg/parsers"
 	"github.com/containers/storage/pkg/system"
+	"github.com/containers/storage/pkg/tempdir"
 	"github.com/opencontainers/selinux/go-selinux/label"
 	"github.com/sirupsen/logrus"
 	"github.com/vbatts/tar-split/tar/storage"
@@ -67,6 +68,12 @@ func Init(home string, options graphdriver.Options) (graphdriver.Driver, error)
 	d.updater = graphdriver.NewNaiveLayerIDMapUpdater(d)
 	d.naiveDiff = graphdriver.NewNaiveDiffDriver(d, d.updater)
 
+	t, err := tempdir.NewTempDir(d.home)
+	if err != nil {
+		return nil, err
+	}
+	d.tempDirectory = t
+
 	return d, nil
 }
 
@@ -82,6 +89,9 @@ type Driver struct {
 	naiveDiff         graphdriver.DiffDriver
 	updater           graphdriver.LayerIDMapUpdater
 	imageStore        string
+
+	// This fled is read-only. Should be save to access without any locking.
+	tempDirectory *tempdir.TempDir
 }
 
 func (d *Driver) String() string {
@@ -100,7 +110,8 @@ func (d *Driver) Metadata(id string) (map[string]string, error) {
 
 // Cleanup is used to implement graphdriver.ProtoDriver. There is no cleanup required for this driver.
 func (d *Driver) Cleanup() error {
-	return nil
+	// TODO: UPDATE comment
+	return d.tempDirectory.Cleanup()
 }
 
 type fileGetNilCloser struct {
@@ -241,7 +252,7 @@ func (d *Driver) dir(id string) string {
 
 // Remove deletes the content from the directory for a given id.
 func (d *Driver) Remove(id string) error {
-	return system.EnsureRemoveAll(d.dir(id))
+	return d.tempDirectory.Add(d.dir(id))
 }
 
 // Get returns the directory for the given id.

layers.go

@@ -26,6 +26,7 @@ import (
 	"github.com/containers/storage/pkg/stringid"
 	"github.com/containers/storage/pkg/system"
 	"github.com/containers/storage/pkg/tarlog"
+	"github.com/containers/storage/pkg/tempdir"
 	"github.com/containers/storage/pkg/truncindex"
 	"github.com/klauspost/pgzip"
 	digest "github.com/opencontainers/go-digest"
@@ -345,6 +346,8 @@ type rwLayerStore interface {
 
 	// Dedup deduplicates layers in the store.
 	dedup(drivers.DedupArgs) (drivers.DedupResult, error)
+
+	CleanupTemporaryDirectories() error
 }
 
 type multipleLockFile struct {
@@ -435,6 +438,9 @@ type layerStore struct {
 	// FIXME: This field is only set when constructing layerStore, but locking rules of the driver
 	// interface itself are not documented here.
 	driver drivers.Driver
+
+	// This fled is read-only. Should be save to access without any locking.
+	tempDirectory *tempdir.TempDir
 }
 
 func copyLayer(l *Layer) *Layer {
@@ -794,6 +800,12 @@ func (r *layerStore) load(lockedForWriting bool) (bool, error) {
 	layers := []*Layer{}
 	ids := make(map[string]*Layer)
 
+	if r.lockfile.IsReadWrite() {
+		if err := tempdir.RecoverStaleDirs(r.tempDirectory.RootDir); err != nil {
+			return false, err
+		}
+	}
+
 	for locationIndex := range numLayerLocationIndex {
 		location := layerLocationFromIndex(locationIndex)
 		rpath := r.jsonPath[locationIndex]
@@ -936,6 +948,11 @@ func (r *layerStore) load(lockedForWriting bool) (bool, error) {
 		for _, layer := range layersToDelete {
 			logrus.Warnf("Found incomplete layer %q, deleting it", layer.ID)
 			err := r.deleteInternal(layer.ID)
+			defer func() {
+				if err := r.CleanupTemporaryDirectories(); err != nil {
+					logrus.Errorf("Error cleaning up temporary directories: %v", err)
+				}
+			}()
 			if err != nil {
 				// Don't return the error immediately, because deleteInternal does not saveLayers();
 				// Even if deleting one incomplete layer fails, call saveLayers() so that other possible successfully
@@ -1164,7 +1181,8 @@ func (s *store) newLayerStore(rundir, layerdir, imagedir string, driver drivers.
 		byname:  make(map[string]*Layer),
 		bymount: make(map[string]*Layer),
 
-		driver: driver,
+		driver:        driver,
+		tempDirectory: s.tempDirectory,
 	}
 	if err := rlstore.startWritingWithReload(false); err != nil {
 		return nil, err
@@ -1919,7 +1937,17 @@ func layerHasIncompleteFlag(layer *Layer) bool {
 	return false
 }
 
+func (r *layerStore) CleanupTemporaryDirectories() error {
+	err := r.tempDirectory.Cleanup()
+	if errDriver := r.driver.Cleanup(); errDriver != nil {
+		return errors.Join(err, errDriver)
+	}
+	return err
+}
+
 // Requires startWriting.
+// Caller MUST run CleanupTemporaryDirectories() after this. Ideally outside of
+// the startWriting.
 func (r *layerStore) deleteInternal(id string) error {
 	if !r.lockfile.IsReadWrite() {
 		return fmt.Errorf("not allowed to delete layers at %q: %w", r.layerdir, ErrStoreIsReadOnly)
@@ -1943,8 +1971,10 @@ func (r *layerStore) deleteInternal(id string) error {
 	if err := r.driver.Remove(id); err != nil && !errors.Is(err, os.ErrNotExist) {
 		return err
 	}
-	os.Remove(r.tspath(id))
-	os.RemoveAll(r.datadir(id))
+	_ = r.tempDirectory.Add(r.tspath(id))
+	// os.Remove(r.tspath(id))
+	_ = r.tempDirectory.Add(r.datadir(id))
+	// os.RemoveAll(r.datadir(id))
 	delete(r.byid, id)
 	for _, name := range layer.Names {
 		delete(r.byname, name)
@@ -1988,6 +2018,8 @@ func (r *layerStore) deleteInDigestMap(id string) {
 }
 
 // Requires startWriting.
+// Caller MUST run CleanupTemporaryDirectories() after this. Ideally outside of
+// the startWriting.
 func (r *layerStore) Delete(id string) error {
 	layer, ok := r.lookup(id)
 	if !ok {