If a client is unresponsive and refuses to release caps, the MDS should allow for a configurable timeout (default unlimited) where it automatically evicts that client to forcibly release its caps.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2019:0020