mount: a fix to prevent possible repeated calls

related to https://github.com/bazil/fuse/issues/130

weed/filesys/unimplemented.go

@@ -0,0 +1,20 @@
+package filesys
+
+import (
+	"context"
+
+	"github.com/seaweedfs/fuse"
+	"github.com/seaweedfs/fuse/fs"
+)
+
+// https://github.com/bazil/fuse/issues/130
+
+var _ = fs.NodeAccesser(&Dir{})
+func (dir *Dir) Access(ctx context.Context, req *fuse.AccessRequest) error {
+	return fuse.ENOSYS
+}
+
+var _ = fs.NodeAccesser(&File{})
+func (file *File) Access(ctx context.Context, req *fuse.AccessRequest) error {
+	return fuse.ENOSYS
+}