These messages based on our prep stage during XL
and prints more informative message regarding
drive information.
This change also does a much needed refactoring.
- Instrumentation for locks.
- Detailed test coverage.
- Adding RPC control handler to fetch lock instrumentation.
- RPC control handlers suite tests with a test RPC server.
This PR contains various fixes for the distributed release:
- Use DRWMutex in namespace-lock only for a single Lock()/RLock() call in conformance to server-side rw-locking as implemented in minio/dsync
- Implement missing cases in lock-rpc-server to catch Unlock() for active read locks and RUnlock() for an active write lock
- Refactor RPCClient to release local mutex while making actual RPC.Call()
