Hi, On 2020-07-21 12:44:09 -0700, Andy Lutomirski wrote: > Can you enlighten me? I don't see any iov_iter_get_pages() calls or > equivalents. If an IO is punted, how does the data end up in the > io_uring_enter() caller's mm? For operations needing that io_op_def.needs_mm is true. Which is checked by io_prep_async_work(), adding the current mm to req. On the wq side io_wq_switch_mm() uses that mm when executing the queue entry. Greetings, Andres Freund