From a8a81d1232b82009f6f87dbe4caf85c9d9d2f589 Mon Sep 17 00:00:00 2001
From: Kroese <kroese@users.noreply.github.com>
Date: Sat, 15 Apr 2023 17:53:14 +0200
Subject: [PATCH] Allow disk resizing

Allow disk resizing
---
 disk.sh | 50 ++++++++++++++++++++++++++++++--------------------
 1 file changed, 30 insertions(+), 20 deletions(-)

diff --git a/disk.sh b/disk.sh
index be1897a..1083a53 100644
--- a/disk.sh
+++ b/disk.sh
@@ -12,9 +12,9 @@ DISK_SIZE=$(echo "${DISK_SIZE}" | sed 's/MB/M/g;s/GB/G/g;s/TB/T/g')
 
 [ -f "$IMG/data$DISK_SIZE.img" ] && mv -f "$IMG/data$DISK_SIZE.img" "${DATA}"
 
-NEW_SIZE=$(numfmt --from=iec "${DISK_SIZE}")
+DATA_SIZE=$(numfmt --from=iec "${DISK_SIZE}")
 
-if (( NEW_SIZE < 6442450944 )); then
+if (( DATA_SIZE < 6442450944 )); then
   echo "ERROR: Please increase DISK_SIZE to at least 6 GB." && exit 83
 fi
 
@@ -22,24 +22,34 @@ if [ -f "${DATA}" ]; then
 
   OLD_SIZE=$(stat -c%s "${DATA}")
 
-  # Resize disk to new size if needed
+  if [ "$DATA_SIZE" -gt "$OLD_SIZE" ]; then
 
-  if [ "$NEW_SIZE" -ne "$OLD_SIZE" ]; then
-
-    if [ "$NEW_SIZE" -gt "$OLD_SIZE" ]; then
-      echo "Resizing data disk from $OLD_SIZE to $NEW_SIZE bytes.."
-      fallocate -l "${NEW_SIZE}" "${DATA}"
+    echo "Resizing data disk from $OLD_SIZE to $DATA_SIZE bytes.."
+           
+    REQ=$((DATA_SIZE-OLD_SIZE))
+      
+    # Check free diskspace    
+    SPACE=$(df --output=avail -B 1 "${IMG}" | tail -n 1)
+      
+    if (( REQ > SPACE )); then
+      echo "ERROR: Not enough free space to resize virtual disk." && exit 84
     fi
 
-    if [ "$NEW_SIZE" -lt "$OLD_SIZE" ]; then
-
-      echo "INFO: Shrinking existing disks is not supported yet!"
-      echo "INFO: Creating backup of old drive in storage folder..."
-
-      mv -f "${DATA}" "${DATA}.bak"
-
+    if ! fallocate -l "${DATA_SIZE}" "${DATA}"; then
+      echo "ERROR: Could not allocate file for virtual disk." && exit 85
     fi
+      
   fi
+
+  if [ "$DATA_SIZE" -lt "$OLD_SIZE" ]; then
+
+    echo "INFO: Shrinking existing disks is not supported yet!"
+    echo "INFO: Creating backup of old drive in storage folder..."
+
+    mv -f "${DATA}" "${DATA}.bak"
+
+  fi
+  
 fi
 
 if [ ! -f "${DATA}" ]; then
@@ -47,19 +57,19 @@ if [ ! -f "${DATA}" ]; then
   # Check free diskspace
   SPACE=$(df --output=avail -B 1 "${IMG}" | tail -n 1)
 
-  if (( NEW_SIZE > SPACE )); then
-    echo "ERROR: Not enough free space to create virtual disk." && exit 84
+  if (( DATA_SIZE > SPACE )); then
+    echo "ERROR: Not enough free space to create virtual disk." && exit 86
   fi
 
   # Create an empty file
-  if ! fallocate -l "${NEW_SIZE}" "${DATA}"; then
+  if ! fallocate -l "${DATA_SIZE}" "${DATA}"; then
     rm -f "${DATA}"
-    echo "ERROR: Could not allocate file for virtual disk." && exit 85
+    echo "ERROR: Could not allocate file for virtual disk." && exit 87
   fi
 
   # Check if file exists
   if [ ! -f "${DATA}" ]; then
-    echo "ERROR: Virtual DSM data disk does not exist ($DATA)" && exit 86
+    echo "ERROR: Virtual DSM data disk does not exist ($DATA)" && exit 88
   fi
 
   # Format as BTRFS filesystem