From: Jens Axboe Date: Mon, 6 Mar 2023 20:15:06 +0000 (-0700) Subject: io_uring: handle TIF_NOTIFY_RESUME when checking for task_work X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=54df6c5edf87df71f8a144ee6e0f04cde180aea2;p=linux.git io_uring: handle TIF_NOTIFY_RESUME when checking for task_work commit b5d3ae202fbfe055aa2a8ae8524531ee1dcab717 upstream. If TIF_NOTIFY_RESUME is set, then we need to call resume_user_mode_work() for PF_IO_WORKER threads. They never return to usermode, hence never get a chance to process any items that are marked by this flag. Most notably this includes the final put of files, but also any throttling markers set by block cgroups. Cc: stable@vger.kernel.org # 5.10+ Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 51d6fbe17f7f3..9911b60f9645d 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -2463,6 +2463,13 @@ static inline unsigned int io_put_rw_kbuf(struct io_kiocb *req) static inline bool io_run_task_work(void) { + /* + * PF_IO_WORKER never returns to userspace, so check here if we have + * notify work that needs processing. + */ + if (current->flags & PF_IO_WORKER && + test_thread_flag(TIF_NOTIFY_RESUME)) + tracehook_notify_resume(NULL); if (test_thread_flag(TIF_NOTIFY_SIGNAL) || current->task_works) { __set_current_state(TASK_RUNNING); tracehook_notify_signal();