du uses `st_blocks`, not `st_size`, so it should be fine for most applications. It is similar to how sparse files behave: $ ls $ truncate -s 1M foo

du uses `st_blocks`, not `st_size`, so it should be fine for most applications. It is similar to how sparse files behave: $ ls $ truncate -s 1M foo $ ls -lhp total 0 -rw-r--r-- 1 catwell wheel 1.0M Apr 26 18:39 foo $ du 0 .