Mount shared_data within a lock
Mount shared_data within a lock

This is intended as a temporary fix and should be removed once BPM (or
some other thing) allows us to mount shared_data into multiple BPM BPM
containers in a safe way.

Some ideas:
- BPM mounts atomically
- BOSH fixes pre-start

[#160322138]

Co-authored-by: Giuseppe Capizzi <1968455d84ef56ceb93e8ec69a3034a6fe0ab9cc@pivotal.io>

cloudfoundry-incubator/guardian-release,cloudfoundry-incubator/guardian-release,cloudfoundry-incubator/guardian-release