Bug#798465: grub-installer: Please show size as well as the device id when selecting target

[Chris Lamb <lamby@debian.org>]

Package: grub-installer
Version: 1.126
Severity: wishlist
Tags: patch

Hi,

On a recent install, I had to switch to the console during the as the
/dev/sdX names and device IDs were not sufficient for me to be 100% sure
I was installing grub to the right device.

Showing the device sizes would have been enough for me to avoid this (as
the sizes were widely different), and would provide a reassurance in
other cases where I was merely slightly uncertain.

Patch attached. I've retained the double-space between the device path
and the start of the metadata. Example screenshot here:
http://i.imgur.com/JSXrJ48.png  


Regards,

-- 
      ,''`.
     : :'  :     Chris Lamb
     `. `'`      lamby@debian.org / chris-lamb.co.uk
       `-

diff --git a/grub-installer b/grub-installer
index c407cd1..e340e1b 100755
--- a/grub-installer
+++ b/grub-installer
@@ -222,6 +222,11 @@ devices_to_ids()
 	echo "$ids"
 }
 
+convert_to_megabytes() {
+	local size="$1"
+	expr 0000000"$size" : '0*\(..*\)......$'
+}
+
 rootfs=$(findfs /)
 bootfs=$(findfs /boot)
 [ -n "$bootfs" ] || bootfs="$rootfs"
@@ -634,7 +639,7 @@ db_progress INFO grub-installer/progress/step_bootdev
 select_bootdev() {
 	debug "select_bootdev: arg='$1'"
 
-	local dev_list dev_descr grubdev devices disk_id dev descr
+	local dev_list dev_descr grubdev devices disk_id dev descr devinfo devsize
 	local default_choice chosen result
 
 	result=""
@@ -652,13 +657,14 @@ select_bootdev() {
 		disk_id="$(device_to_id $grubdev)"
 		dev="$(readlink -f "$disk_id")"
 		dev_list="${dev_list:+$dev_list, }$dev"
+		devinfo=""
 		descr="$(echo $disk_id |sed -e 's+^.*/++' |sed -e 's+,+\\,+g')"
-		if [ "$dev" = "$disk_id" ]; then
-			dev_descr="${dev_descr:+$dev_descr, }$dev"
-		else
-			#/dev/sdX (id)
-			dev_descr="${dev_descr:+$dev_descr, }$dev  ($descr)"
+		if [ "$dev" != "$disk_id" ]; then
+			devinfo="${devinfo:+$devinfo\, }$descr"
 		fi
+		devsize="$(blockdev --getsize64 "$dev")"
+		devinfo="${devinfo:+$devinfo\, }$(convert_to_megabytes "$devsize")MB"
+		dev_descr="${dev_descr:+$dev_descr, }$dev${devinfo:+  ($devinfo)}"
 	done
 
 	debug "Bootdev Choices: '$dev_list'"