Mike Fleetwood authored Nov 30, 2015 and Curtis Gedak committed Jan 29, 2016

Only load the LUKS_Info cache of active dm-crypt mappings when the first
LUKS partition is encountered.  Not needed from a performance point of
view as the longest that I have ever seen "dmsetup table --target crypt"
take to run is 0.05 seconds.  Just means that the dmsetup command is
only run when there are LUKS partitions and the information is needed.

Bug 760080 - Implement read-only LUKS support