virt-make-fs: Provide a clearer error message when mkfs fails (RHBZ#823883).

(cherry picked from commit 975a41db20eff2b5edf510f8a65005c915b21f27)

1 files changed, 13 insertions, 1 deletions

diff --git a/tools/virt-make-fs b/tools/virt-make-fs
index 6efa3cd0..072a517c 100755
--- a/tools/virt-make-fs
+++ b/tools/virt-make-fs
@@ -456,7 +456,19 @@ eval {
 
     # Create the filesystem.
     if ($type ne "btrfs") {
-        $g->mkfs ($type, $dev);
+        eval {
+            $g->mkfs ($type, $dev);
+        };
+        if ($@) {
+            # Provide more guidance in the error message (RHBZ#823883).
+            print STDERR "'mkfs' (create filesystem) operation failed.\n";
+            if ($type eq "fat") {
+                print STDERR "Instead of 'fat', try 'vfat' (long filenames) or 'msdos' (short filenames).\n";
+            } else {
+                print STDERR "Is '$type' a correct filesystem type?\n";
+            }
+            die
+        }
     } else {
         $g->mkfs_btrfs ([$dev], datatype => "single", metadata => "single");
     }