Bug #21353
Updated by Jason Dillaman over 6 years ago
Three mailing list users have reported apparent filesystem corrupt post-upgrade to Luminous when using QEMU. Mapping the images via krbd and checking the filesystems showed no corruption and exporting/re-importing the images allowed QEMU to work again.
http://lists.ceph.com/pipermail/ceph-users-ceph.com/2017-September/020648.html