diff -Nru initramfs-tools-devices-0.3/debian/changelog initramfs-tools-devices-0.4/debian/changelog
--- initramfs-tools-devices-0.3/debian/changelog	2018-12-05 14:47:23.000000000 +0100
+++ initramfs-tools-devices-0.4/debian/changelog	2019-03-11 12:30:29.000000000 +0100
@@ -1,3 +1,10 @@
+initramfs-tools-devices (0.4) disco; urgency=medium
+
+  * Change resize script so it expands the filesystem also when
+    the partition is bigger than it already.
+
+ -- Alfonso Sanchez-Beato (email Canonical) <alfonso.sanchez-beato@canonical.com>  Mon, 11 Mar 2019 12:30:29 +0100
+
 initramfs-tools-devices (0.3) disco; urgency=medium
 
   * Add some missing binaries to the initramfs
diff -Nru initramfs-tools-devices-0.3/hooks/resize initramfs-tools-devices-0.4/hooks/resize
--- initramfs-tools-devices-0.3/hooks/resize	2018-12-05 14:36:56.000000000 +0100
+++ initramfs-tools-devices-0.4/hooks/resize	2019-03-11 12:28:59.000000000 +0100
@@ -23,6 +23,7 @@
 copy_exec /sbin/findfs /sbin
 copy_exec /sbin/parted /sbin
 copy_exec /sbin/sgdisk /sbin
+copy_exec /sbin/dumpe2fs /sbin
 copy_exec /sbin/resize2fs /sbin
 copy_exec /sbin/blockdev /sbin
 copy_exec /usr/bin/realpath
diff -Nru initramfs-tools-devices-0.3/scripts/local-premount/resize initramfs-tools-devices-0.4/scripts/local-premount/resize
--- initramfs-tools-devices-0.3/scripts/local-premount/resize	2018-08-23 10:22:35.000000000 +0200
+++ initramfs-tools-devices-0.4/scripts/local-premount/resize	2019-03-11 12:30:02.000000000 +0100
@@ -21,6 +21,7 @@
 
 wait-for-root "LABEL=writable" "${ROOTDELAY:-180}" >/dev/null || true
 
+# shellcheck disable=SC2013
 for opt in $(cat /proc/cmdline); do
     case $opt in
         debug)
@@ -31,12 +32,13 @@
 
 writable_part="$(findfs LABEL=writable)"
 
-syspath="$(dirname $(realpath /sys/class/block/$(basename $writable_part)))"
-device="$(realpath /dev/block/$(cat $syspath/dev))"
-partition=$(cat $syspath/$(basename $writable_part)/partition)
-
-device_size="$(($(cat $syspath/size)/2))"
-sum_size="$(($(grep $(basename $device)[a-z0-9] /proc/partitions|\
+syspath="$(dirname "$(realpath /sys/class/block/"$(basename "$writable_part")")")"
+device="$(realpath /dev/block/"$(cat "$syspath"/dev)")"
+partition=$(cat "$syspath"/"$(basename "$writable_part")"/partition)
+
+# We use 1024 bytes blocks for the operations
+device_size="$(($(cat "$syspath"/size)/2))"
+sum_size="$(($(grep "$(basename "$device")[a-z0-9]" /proc/partitions|\
     tr -s ' '|cut -d' ' -f4|tr '\n' '+'|sed 's/+$//')))"
 
 get_end()
@@ -44,11 +46,11 @@
     NUM=$1
     lastpart="$(grep -cE ^'[0-9]{1,}': $TMPFILE)"
     if [ "$lastpart" = "$NUM" ]; then
-        endsize="$(parted -ms $DEV print| grep ^/ | cut -d: -f2)"
+        endsize="$(parted -ms "$DEV" print| grep ^/ | cut -d: -f2)"
     else
         # we are not at the end ! get the start of the next partition
         # (minus 1 byte) instead of using the absolute end of the disk
-        endsize=$(($(parted -ms $DEV unit B print|grep ^$(($num+1)):|\
+        endsize=$(($(parted -ms "$DEV" unit B print|grep ^$((NUM+1)):|\
             cut -d: -f2|sed 's/B$//')-1))
     fi
     echo "$endsize"
@@ -58,66 +60,89 @@
 {
     DISK=$1
 
-    PARTNUM="$(sgdisk -p $DISK|grep writable|sed -r 's/^([^ ]*[ ]*){1}([^ ]*).*/\2/')"
-    GUID="$(sgdisk -i $PARTNUM $DISK|grep unique| sed 's/^.*: //g')"
-    FIRST="$(sgdisk -i $PARTNUM $DISK|grep ^First| sed 's/^.*: //g;s/ .*$//')"
-
-    echo "fixing backup GPT" >>$LOGFILE 2>&1
-    sgdisk --move-second-header $DISK >>$LOGFILE 2>&1
-
-    echo "Deleting partition $PARTNUM" >>$LOGFILE 2>&1
-    sgdisk -d $PARTNUM $DISK >>$LOGFILE 2>&1
-
-    echo "Creating partition $PARTNUM at $FIRST" >>$LOGFILE 2>&1
-    sgdisk -n $PARTNUM:$FIRST:0 $DISK >>$LOGFILE 2>&1
-
-    echo "Setting GUID of partition $PARTNUM to $GUID" >>$LOGFILE 2>&1
-    sgdisk -u $PARTNUM:$GUID $DISK >>$LOGFILE 2>&1
-
-    echo "Setting name of $PARTNUM to writable" >>$LOGFILE 2>&1
-    sgdisk -c $PARTNUM:writable $DISK >>$LOGFILE 2>&1
-
-    sgdisk -p $DISK >/run/initramfs/new-gpt-table.txt 2>/dev/null
+    PARTNUM="$(sgdisk -p "$DISK"|grep writable|sed -r 's/^([^ ]*[ ]*){1}([^ ]*).*/\2/')"
+    GUID="$(sgdisk -i "$PARTNUM" "$DISK"|grep unique| sed 's/^.*: //g')"
+    FIRST="$(sgdisk -i "$PARTNUM" "$DISK"|grep ^First| sed 's/^.*: //g;s/ .*$//')"
+
+    {
+        echo "fixing backup GPT"
+        sgdisk --move-second-header "$DISK"
+        
+        echo "Deleting partition $PARTNUM"
+        sgdisk -d "$PARTNUM" "$DISK"
+        
+        echo "Creating partition $PARTNUM at $FIRST"
+        sgdisk -n "$PARTNUM":"$FIRST":0 "$DISK"
+        
+        echo "Setting GUID of partition $PARTNUM to $GUID"
+        sgdisk -u "$PARTNUM":"$GUID" "$DISK"
+        
+        echo "Setting name of $PARTNUM to writable"
+        sgdisk -c "$PARTNUM":writable "$DISK"
+        
+        sgdisk -p "$DISK" >/run/initramfs/new-gpt-table.txt 2>/dev/null
+    } >>$LOGFILE 2>&1
 }
 
 do_mbr()
 {
     DEV=$1
     PART=$2
-    endsize=$(get_end $PART)
-    parted -s $DEV resizepart $PART $endsize
+    endsize=$(get_end "$PART")
+    parted -s "$DEV" resizepart "$PART" "$endsize"
 }
 
+resize_filesystem()
+{
+    # make sure the partitions are ready for further use
+    udevadm settle
+    # check the filesystem before attempting re-size
+    e2fsck -fy "$writable_part"
+    # resize the filesystem to full size of the partition
+    resize2fs "$resizeopts" "$writable_part"
+}
 
-free_space=$(($device_size-$sum_size))
-min_free_space=$(($device_size/10))
+free_space=$((device_size-sum_size))
+min_free_space=$((device_size/10))
+filesystem_size=$(dumpe2fs -h "$writable_part" |
+                      awk -F: '/Block count/{count=$2} /Block size/{size=$2} END{print count*size/1024}')
+partition_size=$(grep "$(basename "$writable_part")" < /proc/partitions |
+                     tr -s ' ' | cut -d' ' -f4)
+free_partition_space=$((partition_size - filesystem_size))
+min_free_partition_size=$((partition_size/10))
+
+# this should never be empty, else argument checking of resize2fs 
+# will recognize it as empty string (due to the quoting of the arg below) and fail
+resizeopts="-p"
 
 if [ "$min_free_space" -lt "$free_space" ]; then
-    echo "initrd: found more than 10% free space on disk, resizing ${writable_part}" >/dev/kmsg || true
+    echo "initrd: found more than 10% free space on disk, resizing ${writable_part}"\
+         >/dev/kmsg || true
     echo "initrd: partition to full disk size, see ${LOGFILE} for details" >/dev/kmsg || true
     # back up the original partition table for later use or debugging
-    parted -ms $device unit B print >$TMPFILE 2>/dev/null
+    parted -ms "$device" unit B print >$TMPFILE 2>/dev/null
     # grow our selected partition to max space available
-    table="$(parted -ms $device print| grep ^/| cut -d: -f6)"
+    table="$(parted -ms "$device" print| grep ^/| cut -d: -f6)"
     case $table in
         gpt)
             # do_gpt needs the device name
-            do_gpt $device >>$LOGFILE 2>&1
+            do_gpt "$device" >>$LOGFILE 2>&1       
             ;;
         mbr|msdos)
             # do_mbr needs the device node and partition number
-            do_mbr $device $partition >>$LOGFILE 2>&1
-            resizeopts="-f"
+            do_mbr "$device" "$partition" >>$LOGFILE 2>&1
+            resizeopts="-fp"
             ;;
         *)
             echo "unknown partition table type, not resizing" >>$LOGFILE
             exit 0
             ;;
     esac
-    # make sure the partitions are ready for further use
-    udevadm settle >>$LOGFILE 2>&1
-    # check the filesystem before attempting re-size
-    e2fsck -fy $writable_part >>$LOGFILE 2>&1
-    # resize the filesystem to full size of the partition
-    resize2fs $resizeopts $writable_part >>$LOGFILE 2>&1
+    resize_filesystem >>$LOGFILE 2>&1
+
+elif [ "$min_free_partition_size" -lt "$free_partition_space" ]; then
+
+    echo "initrd: found more than 10% free space on ${writable_part}, resizing filesystem"\
+         >/dev/kmsg || true
+    resize_filesystem >>$LOGFILE 2>&1
 fi