My friend pinged me and told that there is a .tmp file in the APPLPTMP which is rapidly growing and filling up the mount point. Below is the query we used to find the culprit.
SELECT a.request_id FROM apps.fnd_concurrent_requests a, apps.fnd_concurrent_processes b WHERE a.controlling_manager = b.concurrent_process_id and b.plsql_out='o0155932.tmp';
