From 54df6c5edf87df71f8a144ee6e0f04cde180aea2 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Mon, 6 Mar 2023 13:15:06 -0700
Subject: [PATCH] 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 <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
io_uring/io_uring.c | 7 +++++++
1 file changed, 7 insertions(+)
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();
--
2.30.2