New kernel argument syntax for LUKS-keydev is introduced:
rd.luks.key=<key_path>[:<key_dev>[:<luks_dev>]]
Unfolding <key_dev> in BNF:
<key_dev> ::= "UUID=" <uuid> | "LABEL=" <label> | <kname>
Where <kname> matches following regular expression:
^/dev/.*
<kname> need to be a character device and not a symlink for now.
For every rd.luks.key argument udev rule is created. That rule runs
test to check whether matching device contains <key_path>. If it does
it's applied to matching <luks_dev>.
Amadeusz Żołnowski