When called with a "map" parameter, the rbdmap script iterates the list
of images present in RBDMAPFILE (/etc/ceph/rbdmap), and maps each entry.
When called with "unmap", rbdmap currently iterates *all* mapped RBD
images and unmaps each one, regardless of whether it's listed in the
RBDMAPFILE or not.
This commit adds functionality such that only RBD images listed in the
configuration file are unmapped. This behaviour is the new default for
"rbdmap unmap". A new "unmap-all" parameter is added to offer the old
unmap-all-rbd-images behaviour, which is used by the systemd service.
Fixes: http://tracker.ceph.com/issues/18884
Signed-off-by: David Disseldorp <ddiss@suse.de>
