Replaced _is_mounted(DATABASE_PATH) by is_controller() when relevant.

Also some explanations on new LINSTOR_AUTO_BACKUP_DELAY in constants.py

Signed-off-by: Arnaud Garcia-Fernandez <arnaud.garcia-fernandez@vates.tech>

Author: Ythogtha

drivers/constants.py

@@ -12,4 +12,5 @@
 # on the master.
 NS_PREFIX_LVM: Final = "lvm-"
 
+# Delay in seconds between two LINSTOR DB backups when launched by the check_sr helper.
 LINSTOR_AUTO_BACKUP_DELAY = 3600

drivers/linstorvolumemanager.py

@@ -3049,15 +3049,15 @@ def force_exec(fn):
                 except Exception:
                     pass
 
-            if mount == cls._is_mounted(DATABASE_PATH):
+            if mount == cls.is_controller():
                 force_exec(lambda: cls._move_files(
                     DATABASE_PATH, backup_path
                 ))
                 force_exec(lambda: cls._mount_volume(
                     volume_path, DATABASE_PATH, not mount
                 ))
 
-            if mount != cls._is_mounted(DATABASE_PATH):
+            if mount != cls.is_controller():
                 force_exec(lambda: cls._move_files(
                     backup_path, DATABASE_PATH
                 ))