make sure result refs returned in errors are clone

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

solver/llbsolver/ops/exec.go

@@ -235,7 +235,7 @@ func (e *execOp) Exec(ctx context.Context, g session.Group, inputs []solver.Resu
 				if m.Input == -1 {
 					continue
 				}
-				execInputs[i] = inputs[m.Input]
+				execInputs[i] = inputs[m.Input].Clone()
 			}
 			execMounts := make([]solver.Result, len(e.op.Mounts))
 			copy(execMounts, execInputs)

solver/llbsolver/ops/file.go

@@ -421,7 +421,6 @@ func (s *FileOpSolver) getInput(ctx context.Context, idx int, inputs []fileoptyp
 					if cerr == nil {
 						outputRes[idx-len(inputs)] = worker.NewWorkerRefResult(ref.(cache.ImmutableRef), s.w)
 					}
-					inpMount.Release(context.TODO())
 				}
 
 				// If the action has a secondary input, commit it and set the ref on

solver/result.go

@@ -47,7 +47,7 @@ type splitResult struct {
 
 func (r *splitResult) Release(ctx context.Context) error {
 	if atomic.AddInt64(&r.released, 1) > 1 {
-		err := errors.Errorf("releasing already released reference")
+		err := errors.Errorf("releasing already released reference %+v", r.Result.ID())
 		logrus.Error(err)
 		return err
 	}
@@ -78,10 +78,14 @@ func NewSharedCachedResult(res CachedResult) *SharedCachedResult {
 	}
 }
 
-func (r *SharedCachedResult) Clone() CachedResult {
+func (r *SharedCachedResult) CloneCachedResult() CachedResult {
 	return &clonedCachedResult{Result: r.SharedResult.Clone(), cr: r.CachedResult}
 }
 
+func (r *SharedCachedResult) Clone() Result {
+	return r.CloneCachedResult()
+}
+
 func (r *SharedCachedResult) Release(ctx context.Context) error {
 	return r.SharedResult.Release(ctx)
 }

solver/scheduler.go

@@ -244,7 +244,7 @@ func (s *scheduler) build(ctx context.Context, edge Edge) (CachedResult, error)
 	if err := p.Receiver.Status().Err; err != nil {
 		return nil, err
 	}
-	return p.Receiver.Status().Value.(*edgeState).result.Clone(), nil
+	return p.Receiver.Status().Value.(*edgeState).result.CloneCachedResult(), nil
 }
 
 // newPipe creates a new request pipe between two edges

solver/scheduler_test.go

@@ -3640,6 +3640,7 @@ type dummyResult struct {
 func (r *dummyResult) ID() string                    { return r.id }
 func (r *dummyResult) Release(context.Context) error { return nil }
 func (r *dummyResult) Sys() interface{}              { return r }
+func (r *dummyResult) Clone() Result                 { return r }
 
 func testOpResolver(v Vertex, b Builder) (Op, error) {
 	if op, ok := v.Sys().(Op); ok {

solver/types.go

@@ -61,6 +61,7 @@ type Result interface {
 	ID() string
 	Release(context.Context) error
 	Sys() interface{}
+	Clone() Result
 }
 
 // CachedResult is a result connected with its cache key

worker/result.go

@@ -52,3 +52,11 @@ func (r *workerRefResult) Release(ctx context.Context) error {
 func (r *workerRefResult) Sys() interface{} {
 	return r.WorkerRef
 }
+
+func (r *workerRefResult) Clone() solver.Result {
+	r2 := *r
+	if r.ImmutableRef != nil {
+		r.ImmutableRef = r.ImmutableRef.Clone()
+	}
+	return &r2
+}