| From 997135017716c33f3405e86cca5da9567b40a08e Mon Sep 17 00:00:00 2001 |
| From: Olivier Langlois <olivier@trillion01.com> |
| Date: Wed, 23 Jun 2021 11:50:11 -0700 |
| Subject: io_uring: Fix race condition when sqp thread goes to sleep |
| |
| From: Olivier Langlois <olivier@trillion01.com> |
| |
| commit 997135017716c33f3405e86cca5da9567b40a08e upstream. |
| |
| If an asynchronous completion happens before the task is preparing |
| itself to wait and set its state to TASK_INTERRUPTIBLE, the completion |
| will not wake up the sqp thread. |
| |
| Cc: stable@vger.kernel.org |
| Signed-off-by: Olivier Langlois <olivier@trillion01.com> |
| Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> |
| Link: https://lore.kernel.org/r/d1419dc32ec6a97b453bee34dc03fa6a02797142.1624473200.git.olivier@trillion01.com |
| Signed-off-by: Jens Axboe <axboe@kernel.dk> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| fs/io_uring.c | 3 ++- |
| 1 file changed, 2 insertions(+), 1 deletion(-) |
| |
| --- a/fs/io_uring.c |
| +++ b/fs/io_uring.c |
| @@ -6876,7 +6876,8 @@ static int io_sq_thread(void *data) |
| } |
| |
| prepare_to_wait(&sqd->wait, &wait, TASK_INTERRUPTIBLE); |
| - if (!test_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state)) { |
| + if (!test_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state) && |
| + !io_run_task_work()) { |
| list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) |
| io_ring_set_wakeup_flag(ctx); |
| |
