Right now we seem to have 3 locks.
- devinfo.lock
This is a per device lock
- metaData.devicesLock
This is supposedely protecting map of devices.
- Global DeviceSet lock
This is protecting map of devices as well as serializing calls to libdevmapper.
Semantics of per devices lock and global deviceset lock seem to be very clear.
Even ordering between these two locks has been defined properly.
What is not clear is the need and ordering of metaData.devicesLock. Looks like
this lock is not necessary and global DeviceSet lock should be used to
protect map of devices as it is part of DeviceSet.
This patchset gets rid of metaData.devicesLock and instead uses DeviceSet
lock to protect map of devices.
Also at couple of places during initialization takes devices.Lock(). That
is not strictly necessary as there is supposed to be one thread of execution
during initializaiton. Still it makes the code clearer.
I think this makes code more clear and easier to understand and easier to
make further changes.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Upstream-commit: 289145ecc6c016b8bb6797cc50905e34da911e84
Component: engine
42e7721be4