there are too many different between g-s-d and u-s-d, and also there is not such file named "*device-mapper.c" in u-s-d, so not sure how to try these patch in comment #3.
there are too many different between g-s-d and u-s-d, and also there is not such file named "*device-mapper.c" in u-s-d, so not sure how to try these patch in comment #3.