fix unmount

Author: pyquick

oclp_r/sys_patch/mount/mount.py

@@ -67,11 +67,15 @@ def _mount_root_volume(self) -> str:
         if self.xnu_major >= os_data.os_data.big_sur.value:
             if Path("/System/Volumes/Update/mnt1/System/Library/CoreServices/SystemVersion.plist").exists():
                 return "/System/Volumes/Update/mnt1"
-            result_unmount = subprocess_wrapper.run_as_root(["/usr/sbin/diskutil", "unmount", f"/dev/{self.root_volume_identifier}"], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)            
-            if result_unmount.returncode != 0:
-                logging.error("Failed to unmount root volume")
+            try:
+                result_unmount = subprocess_wrapper.run_as_root(["/usr/sbin/diskutil", "unmount", f"/dev/{self.root_volume_identifier}"], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)            
+                if result_unmount.returncode != 0:
+                    logging.error("Failed to unmount root volume")
+                    subprocess_wrapper.log(result_unmount)
+                    return None
+            except subprocess.CalledProcessError:
+                logging.error("Disk has already been unmounted.")
                 subprocess_wrapper.log(result_unmount)
-                return None
             result = subprocess_wrapper.run_as_root(["/sbin/mount", "-o", "nobrowse", "-t", "apfs", f"/dev/{self.root_volume_identifier}", "/System/Volumes/Update/mnt1"], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
             if result.returncode != 0:
                 logging.error("Failed to mount root volume")