Merge pull request #1257 from tonistiigi/1903-fix-parent-release

[19.03] cache: fix possible concurrent maps write on parent release
moby · Nov 13, 2019 · 928f3b4 · 928f3b4
2 parents ff93519 + a393a76
commit 928f3b4
Showing 1 changed file with 4 additions and 6 deletions.
diff --git a/cache/refs.go b/cache/refs.go
@@ -185,7 +185,10 @@ func (cr *cacheRecord) Mount(ctx context.Context, readonly bool) (snapshot.Mount
 func (cr *cacheRecord) remove(ctx context.Context, removeSnapshot bool) error {
 	delete(cr.cm.records, cr.ID())
 	if cr.parent != nil {
-		if err := cr.parent.release(ctx); err != nil {
+		cr.parent.mu.Lock()
+		err := cr.parent.release(ctx)
+		cr.parent.mu.Unlock()
+		if err != nil {
 			return err
 		}
 	}
@@ -401,11 +404,6 @@ func (sr *mutableRef) release(ctx context.Context) error {
 				return err
 			}
 		}
-		if sr.parent != nil {
-			if err := sr.parent.release(ctx); err != nil {
-				return err
-			}
-		}
 		return sr.remove(ctx, true)
 	} else {
 		if sr.updateLastUsed() {