On 7/1/21 6:26 AM, Pavel Begunkov wrote: > If one entered io_req_task_work_add() not seeing PF_EXITING, it will set > a ->task_state bit and try task_work_add(), which may fail by that > moment. If that happens the function would try to cancel the request. > > However, in a meanwhile there might come other io_req_task_work_add() > callers, which will see the bit set and leave their requests in the > list, which will never be executed. > > Don't propagate an error, but clear the bit first and then fallback > all requests that we can splice from the list. The callback functions > have to be able to deal with PF_EXITING, so poll and apoll was modified > via changing io_poll_rewait(). > > Reported-by: Jens Axboe <axboe@xxxxxxxxx> > Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx> > --- > > Jens, can you try if it helps with the leak you meantioned? I can't > see it. As with previous, would need to remove the PF_EXITING check, > and should be in theory safe to do. Probably misunderstanding you here, but you already killed the one that patch 3 remove. In any case, I tested this on top of 1+2, and I don't see any leaks at that point. -- Jens Axboe
