A snapshot of a directory with quota set on it, via the xattr "ceph.quota.max_bytes", does not have the same xattr exposed on the snapshot directory. This prevents a clone of a subvolume snapshot, to read and set the same quota on the cloned subvolume.
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 (Red Hat Ceph Storage 4.1 Bug Fix update), 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-2020:4144