pyinotify backend: guarantees initial scanning of log-file by start (retarded via pending event if filter not yet active)

ChangeLog

@@ -34,6 +34,7 @@ ver. 0.10.6-dev (20??/??/??) - development edition
 ### Fixes
 * [stability] prevent race condition - no ban if filter (backend) is continuously busy if
   too many messages will be found in log, e. g. initial scan of large log-file or journal (gh-2660)
+* pyinotify-backend sporadically avoided initial scanning of log-file by start
 * python 3.9 compatibility (and Travis CI support)
 * restoring a large number (500+ depending on files ulimit) of current bans when using PyPy fixed
 * manual ban is written to database, so can be restored by restart (gh-2647)

fail2ban/server/filterpyinotify.py

@@ -271,7 +271,13 @@ class FilterPyinotify(FileFilter):
 
 	def _addLogPath(self, path):
 		self._addFileWatcher(path)
+		# initial scan:
+		if self.active:
+			# we can execute it right now:
 			self._process_file(path)
+		else:
+			# retard until filter gets started:
+			self._addPending(path, ('INITIAL', path))
 
     ##
 	# Delete a log path