diff --git a/pkg/fs/file.go b/pkg/fs/file.go
index 907c4ac..1048208 100644
--- a/pkg/fs/file.go
+++ b/pkg/fs/file.go
@@ -85,12 +85,18 @@ func (f *File) readWithoutCache(p []byte) (n int, err error) {
 	if f.offline {
 		return 0, io.EOF
 	}
+	log := f.log
 	n, err = f.f.Read(p)
+	if n > 0 {
+		if n, err := f.md.WriteAt(p[:n], f.offset); err != nil {
+			log.Error(err, "error writing cache file")
+			return n, err
+		}
+	}
 	if err != nil {
-		f.log.Error(err, "error reading source file")
+		log.Error(err, "error reading source file")
 		return
 	}
-	f.md.WriteAt(p, f.offset)
 	f.md.AddChunk(f.offset, n)
 	f.offset += int64(n)
 	return