fix: Resource Cleanup

Signed-off-by: Shubhranshu Mahapatra <[email protected]>

Author: Shubhranshu153

fs/fs.go

@@ -1230,6 +1230,7 @@ func (fs *filesystem) Unmount(ctx context.Context, mountpoint string) error {
 	// underlying layer, so we cannot call done on it.
 	if !isIDMappedDir(mountpoint) {
 		l.Done()
+		fs.resolver.Evict(l.GetCacheRefKey())
 	}
 	fs.layerMu.Unlock()
 	fs.metricsController.Remove(mountpoint)

fs/layer/layer.go

@@ -104,6 +104,8 @@ type Layer interface {
 	// Done releases the reference to this layer. The resources related to this layer will be
 	// discarded sooner or later. Queries after calling this function won't be serviced.
 	Done()
+
+	GetCacheRefKey() string
 }
 
 // Info is the current status of a layer.
@@ -226,6 +228,12 @@ func newCache(root string, cacheType string, cfg config.FSConfig) (cache.BlobCac
 	)
 }
 
+func (r *Resolver) Evict(name string) {
+	r.layerCacheMu.Lock()
+	r.layerCache.Remove(name)
+	r.layerCacheMu.Unlock()
+}
+
 // Resolve resolves a layer based on the passed layer blob information.
 func (r *Resolver) Resolve(ctx context.Context, hosts []docker.RegistryHost, refspec reference.Spec, desc, sociDesc ocispec.Descriptor, opCounter *FuseOperationCounter, disableVerification bool, metadataOpts ...metadata.Option) (_ Layer, retErr error) {
 	name := refspec.String() + "/" + desc.Digest.String()
@@ -339,7 +347,7 @@ func (r *Resolver) Resolve(ctx context.Context, hosts []docker.RegistryHost, ref
 	}
 	disableXAttrs := getDisableXAttrAnnotation(sociDesc)
 	// Combine layer information together and cache it.
-	l := newLayer(r, desc, blobR, vr, bgLayerResolver, opCounter, disableXAttrs)
+	l := newLayer(r, desc, name, blobR, vr, bgLayerResolver, opCounter, disableXAttrs)
 	r.layerCacheMu.Lock()
 	cachedL, done2, added := r.layerCache.Add(name, l)
 	r.layerCacheMu.Unlock()
@@ -387,6 +395,7 @@ func (r *Resolver) resolveBlob(ctx context.Context, hosts []docker.RegistryHost,
 func newLayer(
 	resolver *Resolver,
 	desc ocispec.Descriptor,
+	cacheRefKey string,
 	blob *blobRef,
 	r reader.Reader,
 	bgResolver backgroundfetcher.Resolver,
@@ -396,6 +405,7 @@ func newLayer(
 	return &layer{
 		resolver:             resolver,
 		desc:                 desc,
+		cacheRefKey:          cacheRefKey,
 		blob:                 blob,
 		r:                    r,
 		bgResolver:           bgResolver,
@@ -405,9 +415,10 @@ func newLayer(
 }
 
 type layer struct {
-	resolver *Resolver
-	desc     ocispec.Descriptor
-	blob     *blobRef
+	resolver    *Resolver
+	desc        ocispec.Descriptor
+	cacheRefKey string
+	blob        *blobRef
 
 	bgResolver backgroundfetcher.Resolver
 
@@ -420,6 +431,10 @@ type layer struct {
 	closedMu sync.Mutex
 }
 
+func (l *layer) GetCacheRefKey() string {
+	return l.cacheRefKey
+}
+
 func (l *layer) Info() Info {
 	return Info{
 		Digest:      l.desc.Digest,

fs/reader/reader.go

@@ -84,6 +84,7 @@ type reader struct {
 
 	closed   bool
 	closedMu sync.Mutex
+	spanMu   sync.Mutex
 
 	disableVerification bool
 }

fs/span-manager/span_manager.go

@@ -430,6 +430,7 @@ func (m *SpanManager) verifySpanContents(compressedData []byte, spanID compressi
 
 // Close closes both the underlying zinfo data and blob cache.
 func (m *SpanManager) Close() {
+	log.L.Debug("Spancache finalizer called. Cleaning up spancache")
 	m.zinfo.Close()
 	m.cache.Close()
 }

snapshot/snapshot.go

@@ -707,7 +707,6 @@ func (o *snapshotter) getCleanupDirectories(ctx context.Context, t storage.Trans
 	if err != nil {
 		return nil, err
 	}
-
 	cleanup := []string{}
 	for _, d := range dirs {
 		if !cleanupCommitted {
@@ -752,8 +751,10 @@ func (o *snapshotter) unmountSnapshotDirectory(ctx context.Context, dir string)
 	if err != nil {
 		if errors.Is(err, os.ErrNotExist) {
 			// nothing to unmount as directory does not exist
+			log.L.Infof("not mounted err ")
 			return nil
 		}
+		log.L.Infof(" mounted err %v", err)
 		return err
 	}
 	if mounted {

util/lrucache/lrucache.go

@@ -76,7 +76,7 @@ func (c *Cache) Get(key string) (value interface{}, done func(), ok bool) {
 	}
 	rc := o.(*refCounter)
 	rc.inc()
-	return rc.v, c.decreaseOnceFunc(rc), true
+	return rc.v, c.releaseReference(rc), true
 }
 
 // Add adds object to the cache and returns the cached contents with incrementing the reference count.
@@ -89,7 +89,7 @@ func (c *Cache) Add(key string, value interface{}) (cachedValue interface{}, don
 	if o, ok := c.cache.Get(key); ok {
 		rc := o.(*refCounter)
 		rc.inc()
-		return rc.v, c.decreaseOnceFunc(rc), false
+		return rc.v, c.releaseReference(rc), false
 	}
 	rc := &refCounter{
 		key:       key,
@@ -99,7 +99,7 @@ func (c *Cache) Add(key string, value interface{}) (cachedValue interface{}, don
 	rc.initialize() // Keep this object having at least 1 ref count (will be decreased in OnEviction)
 	rc.inc()        // The client references this object (will be decreased on "done")
 	c.cache.Add(key, rc)
-	return rc.v, c.decreaseOnceFunc(rc), true
+	return rc.v, c.releaseReference(rc), true
 }
 
 // Remove removes the specified contents from the cache. OnEvicted callback will be called when
@@ -110,12 +110,11 @@ func (c *Cache) Remove(key string) {
 	c.cache.Remove(key)
 }
 
-func (c *Cache) decreaseOnceFunc(rc *refCounter) func() {
-	var once sync.Once
+func (c *Cache) releaseReference(rc *refCounter) func() {
 	return func() {
 		c.mu.Lock()
 		defer c.mu.Unlock()
-		once.Do(func() { rc.dec() })
+		rc.dec()
 	}
 }
 

util/lrucache/lrucache_test.go

@@ -149,8 +149,6 @@ func TestEviction(t *testing.T) {
 	}
 
 	done2() // effective
-	done2() // ignored
-	done2() // ignored
 	if len(evicted) != 1 {
 		t.Errorf("only 1 content must be evicted")
 		return