Some bash help needed

[Gene Czarcinski]

I have located and submitted a patch to correct a problem with grub2's 
handling of a three-device (actually, anything more than two) btrfs 
volume.  Here is the bugzilla report: 
https://bugzilla.redhat.com/show_bug.cgi?id=890955

And here is the patch:
-------------------------------------------------------------------------------------------------------------------
 From 4770be177085a17837687d2d858acfc9696092e1 Mon Sep 17 00:00:00 2001
From: Fedora Ninjas <grub2-owner at fedoraproject.org>
Date: Fri, 11 Jan 2013 10:52:01 -0500
Subject: [PATCH] support for multi-device btrfs volume

The current code produces error messages if passed a device
list with multiple devices for a btrfs volume.  It worked OK
for single device btrfs volume.

This has been regression tested with root/boot on a regular
partition, single device VG logical volume,
and single device btrfs volume.
---
  util/grub-mkconfig_lib.in | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/util/grub-mkconfig_lib.in b/util/grub-mkconfig_lib.in
index 76133b4..8e2ff66 100644
--- a/util/grub-mkconfig_lib.in
+++ b/util/grub-mkconfig_lib.in
@@ -279,7 +279,7 @@ gettext_printf () {
  uses_abstraction () {
    device="$1"

-  abstraction="`"${grub_probe}" --device "${device}" --target=abstraction`"
+  abstraction="`"${grub_probe}" --device ${device} --target=abstraction`"
    for module in ${abstraction}; do
      if test "x${module}" = "x$2"; then
        return 0
-- 
1.8.1
-------------------------------------------------------------------------------------------------------------------
with
device="/dev/vda2
/dev/vdb2
/dev/vdc3"

Can someone more knowledgeable explain?

Gene