I'd like to request that we add (or backport) the "Backup Locks", such as "LOCK TABLES FOR BACKUP", "LOCK BINLOG FOR BACKUP", and "UNLOCK BINLOG" as described here:

https://www.percona.com/doc/percona-server/5.6/management/backup_locks.html#backup-locks

"LOCK TABLES FOR BACKUP uses a new MDL lock type to block updates to non-transactional tables and DDL statements for all tables. More specifically, if there’s an active LOCK TABLES FOR BACKUP lock, all DDL statements and all updates to MyISAM, CSV, MEMORY and ARCHIVE tables will be blocked in the Waiting for backup lock status as visible in PERFORMANCE_SCHEMA or PROCESSLIST.
...
Unlike FLUSH TABLES WITH READ LOCK, LOCK TABLES FOR BACKUP does not flush tables, i.e. storage engines are not forced to close tables and tables are not expelled from the table cache. As a result, LOCK TABLES FOR BACKUP only waits for conflicting statements to complete (i.e. DDL and updates to non-transactional tables). It never waits for SELECTs, or UPDATEs to InnoDB tables to complete, for example.
..."

Thank you for your consideration.