On Tue, Nov 28, 2023 at 09:05:21AM +1100, NeilBrown wrote: > A simple way to fix this is to treat nfsd threads like normal processes > for task_work. Thus the pending files are queued for the thread, and > the same thread finishes the work. > > Currently KTHREADs are assumed never to call task_work_run(). With this > patch that it still the default but it is implemented by storing the > magic value TASK_WORKS_DISABLED in ->task_works. If a kthread, such as > nfsd, will call task_work_run() periodically, it sets ->task_works > to NULL to indicate this. > svc_recv(rqstp); > validate_process_creds(); > + if (task_work_pending(current)) > + task_work_run(); What locking environment and call chain do you have here? And what happens if you get something stuck in ->release()? > > p->pdeath_signal = 0; > - p->task_works = NULL; > + p->task_works = args->kthread ? TASK_WORKS_DISABLED : NULL; Umm... why not have them set (by helper in kernel/task_work.c) to &work_exited? Then the task_work_run parts wouldn't be needed at all...
