- Add cache trylock and read trylock functions.
- Introduce new error code -OCF_ERR_NO_LOCK.
- Change trylock functions in env to return this code in case of
lock contention.
[ENV CHANGES REQUIRED]
Following functions should return 0 on success or -OCF_ERR_NO_LOCK
in case of lock contention:
- env_mutex_trylock()
- env_rwsem_up_read_trylock()
- env_rwsem_up_write_trylock()
Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>