sheepdog: do not blindly memset all read buffers Only buffers that map to unallocated blocks need to be zeroed. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp> Signed-off-by: Kevin Wolf <kwolf@redhat.com>