Currently, locks are not held while time-series queries and updates are parsed to replace the metaField with "meta" in write_commands.cpp and while retrieving the metaField in write_ops_exec.cpp. This may lead to concurrency issues where the collection may be dropped or replaced with another collection before the update executes. To solve this, all the metaField related logic should be moved to performSingleUpdateOp() in write_ops_exec.cpp.