From 4a7d222204572567e6c7d58871911cdc85bf5b3a Mon Sep 17 00:00:00 2001
From: Wolfgang Link <w.link@proxmox.com>
Date: Mon, 27 Jun 2016 12:24:26 +0200
Subject: [PATCH] add check if format is defined to avoid warning

---
 PVE/Storage/Plugin.pm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/PVE/Storage/Plugin.pm b/PVE/Storage/Plugin.pm
index 002b265..8089302 100644
--- a/PVE/Storage/Plugin.pm
+++ b/PVE/Storage/Plugin.pm
@@ -597,7 +597,7 @@ sub free_image {
 
     my $path = $class->filesystem_path($scfg, $volname);
 
-    if ($format eq 'subvol') {
+    if (defined($format) && ($format eq 'subvol')) {
 	File::Path::remove_tree($path);
     } else {