Even at QD=1, dd may take less than 10 seconds to work its way to the end of a 10M image, producing "No space left on device" error instead of the expected "Operation not permitted" error which is supposed to arise from the device getting marked read-only while opened. Fixes: https://tracker.ceph.com/issues/74513 Signed-off-by: Ilya Dryomov <idryomov@gmail.com>