2) curtin will now echo the dname value into /sys/class/block/bcacheX/bcache/label which will
then enable /dev/bcache/by-label/<dname> -> ../../bcacheX
This work needs to be tested on Trusty -> Bionic; I'll work on updating the vmtests for bcache devices to exercise this path.
For the curtin side, the plan is to do two things.
1) update the dname for bcache to use the backing device's dev.uuid value and emit a symlink pointing to a /dev/bcache/by-uuid path. This gives us
/dev/disk/ by-dname/ <name> -> \ ./bcache/ by-uuid/ <dev.uuid> -> \
../../ bcacheX
../.
2) curtin will now echo the dname value into /sys/class/ block/bcacheX/ bcache/ label which will by-label/ <dname> -> ../../bcacheX
then enable /dev/bcache/
This work needs to be tested on Trusty -> Bionic; I'll work on updating the vmtests for bcache devices to exercise this path.