Added failed umount force retry

main.py

@@ -38,6 +38,7 @@ class AppState:
     diskEventQueue: Queue[DiskEvent] = Queue()
     diskState: DiskState = "disconnected"
     config = Config()
+    failedUmount: bool = False
 
 
 def saveConfig(config: Config, path: Path) -> None:
@@ -174,19 +175,31 @@ def mountDisk(state: AppState) -> None:
 
 
 def unmountDisk(state: AppState) -> None:
-    try:
+    if not state.failedUmount:
+        try:
+            subprocess.run(
+                [
+                    "umount",
+                    f"/mnt/{state.config.diskSerial}",
+                ],
+                check=True,
+            )
+            print("unmounting disk")
+        except subprocess.CalledProcessError:
+            state.failedUmount = True
+        else:
+            state.diskState = "disconnected"
+    else:
         subprocess.run(
             [
                 "umount",
+                "-f",
                 f"/mnt/{state.config.diskSerial}",
             ],
-            check=True,
+            check=False,
         )
-        print("unmounting disk")
-    except subprocess.CalledProcessError:
-        pass
-    else:
         state.diskState = "disconnected"
+        state.failedUmount = False
 
 
 def main() -> None: