We currently use a global lock to protect global data (like the
Devices map) as well as device data itself and access to
(non-threadsafe) libdevmapper.
This commit also adds a per-device lock, which will allow per-device
operations to temporarily release the global lock while e.g. waiting.
The per-device lock will make sure that nothing else accesses that
device while we're operating on it.
Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
Upstream-commit: 3e8a02a9399618917194b37435f5eed9ff86fe2f
Component: engine