fix(linstor): Clarifications, documentations, and more explicit work.

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

Author: Ythogtha

drivers/LinstorSR.py

@@ -1579,16 +1579,18 @@ def database_backup(self, name="", *, delay=0, fail=False, controller=False):
         """Generate a new database backup file.
         This operation should not prevent the underlying action to be successful.
         Hence all Exceptions are caught and re-raised only if asked to.
+        delay: skip backup if the last one was generated less than delay seconds ago.
+        fail: If fail is True, caught Exception are raised after being logged in SMlog.
         controller: operate only if the current host is the Linstor Controller.
+         > This will trigger controller-only operations like retention and validation.
         """
         if not self._linstor:
             self._reconnect()
-        if controller:
-            if self._linstor.is_controller():
-                self._linstor.database_invalidation()
-            else:
-                return
+        if controller and not self._linstor.is_controller():
+            return
         try:
+            if controller:
+                self._linstor.database_invalidation()
             self._linstor.database_backup(name, delay=delay)
         except Exception as e:
             util.SMlog(

drivers/linstorvolumemanager.py

@@ -2669,18 +2669,18 @@ def _get_volume_properties(self, volume_uuid):
 
     def _log_database_backup(self, date, name):
         """Log a database backup operation: "date name"
-        We cannot assume the pool-master is the same as the linstor-master,
-        this file is on the pool-master, and serves for the throttling."""
+        We cannot assume the Pool Master is the same as the Linstor Controller,
+        this file is on the Pool Master, and serves for the throttling."""
         os.makedirs(DATABASE_BACKUP_LOGDIR, mode=0o755, exist_ok=True)
         with open(DATABASE_BACKUP_LOGFILE, "a", encoding="utf8") as f:
-            f.write(f"{date} {name}\n")
+            f.write(f"{date} {name[:15]}\n")
 
     def _get_latest_logged_database_backup_date(self):
         # get last log line if it exists, and return the corresponding date
         try:
             with open(DATABASE_BACKUP_LOGFILE, "rb") as f:
-                # seek from the end, with 256 as a most-probable maximum line length
-                f.seek(-min(os.stat(DATABASE_BACKUP_LOGFILE).st_size, 256), os.SEEK_END)
+                # seek from the end, a line length can't be more than 32
+                f.seek(-min(os.stat(DATABASE_BACKUP_LOGFILE).st_size, 32), os.SEEK_END)
                 return f.read().decode().splitlines()[-1].split()[0]
         except FileNotFoundError:
             return "20000101_000000"