09e7eb51d9
When "multipath -f" is run on a device that doesn't exist or isn't a multipath device, the command will not remove any device, but it will still return success. Multiple functions rely on _dm_flush_map() returning success when called with name that doesn't match any multipath device. So before calling _dm_flush_map(), call dm_is_mpath(), to check if the device exists and is a multipath device, and return failure if it's not.