* util/grub-install.in (find_device): New function - find block

device for given file or directory.  Resolve symlinks to fix
problem on Linux with devfs and old device names in /etc/fstab.
Use find_device() for root_device, bootdir_device and
grubdir_device.

util/grub-install.in

@@ -175,6 +175,35 @@ convert () {
     fi
 }
 
+# Usage: find_device file
+# Find block device on which the file resides.
+find_device () {
+    # For now, this uses the program `df' to get the device name, but is
+    # this really portable?
+    tmp_fname=`df $1/ | sed -n 's%.*\(/dev/[^ 	]*\).*%\1%p'`
+
+    if test -z "$tmp_fname"; then
+	echo "Could not find device for $1" 2>&1
+	exit 1
+    fi
+
+    # Resolve symlinks
+    while test -L $tmp_fname; do
+	tmp_new_fname=`ls -al /dev/hda1 | sed -n 's%.*-> %\1%p'`
+	if test -z "$tmp_new_fname"; then
+	    echo "Unrecognized ls output" 2>&1
+	    exit 1
+	fi
+
+	# Convert relative symlinks
+	case $tmp_new_fname in
+	    /*) tmp_fname="$tmp_new_fname" ;;
+	    *) tmp_fname="`echo $tmp_fname | sed 's%/[^/]*$%%'`/$tmp_new_fname" ;;
+	esac
+    done
+    echo "$tmp_fname"
+}
+
 # Check the arguments.
 for option in "$@"; do
     case "$option" in
@@ -308,12 +337,8 @@ case "$install_device" in
 esac
 
 # Get the root drive.
-# For now, this uses the program `df' to get the device name, but is
-# this really portable?
-root_device=`df ${rootdir}/ | grep /dev/ \
-    | sed 's%.*\(/dev/[^ 	]*\).*%\1%'`
-bootdir_device=`df ${bootdir} | grep /dev/ \
-    | sed 's%.*\(/dev/[^ 	]*\).*%\1%'`
+root_device=`find_device ${rootdir}`
+bootdir_device=`find_device ${bootdir}`
 
 # Check if the boot directory is in the same device as the root directory.
 if test "x$root_device" != "x$bootdir_device"; then
@@ -330,8 +355,8 @@ fi
 
 # Check if the root directory exists in the same device as the grub
 # directory.
-grubdir_device=`df ${grubdir} | grep /dev/ \
-    | sed 's%.*\(/dev/[^ 	]*\).*%\1%'`
+grubdir_device=`find_device ${grubdir}`
+
 if test "x$grubdir_device" != "x$root_device"; then
     # For now, cannot deal with this situation.
     cat <<EOF 1>&2