io-wq: don't retry task_work creation failure on fatal conditions

[ Upstream commit a226abcd5d ]

We don't want to be retrying task_work creation failure if there's
an actual signal pending for the parent task. If we do, then we can
enter an infinite loop of perpetually retrying and each retry failing
with -ERESTARTNOINTR because a signal is pending.

Fixes: 3146cba99a ("io-wq: make worker creation resilient against signals")
Reported-by: Florian Fischer <florian.fl.fischer@fau.de>
Link: https://lore.kernel.org/io-uring/20211202165606.mqryio4yzubl7ms5@pasture/
Tested-by: Florian Fischer <florian.fl.fischer@fau.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Jens Axboe 2021-12-02 19:40:15 -07:00 committed by Justin Hammond
parent 04546f9c9d
commit 0dd89bb8f0

View file

@ -711,6 +711,13 @@ static bool io_wq_work_match_all(struct io_wq_work *work, void *data)
static inline bool io_should_retry_thread(long err)
{
/*
* Prevent perpetual task_work retry, if the task (or its group) is
* exiting.
*/
if (fatal_signal_pending(current))
return false;
switch (err) {
case -EAGAIN:
case -ERESTARTSYS: