io_uring: fail links of cancelled timeouts

When we cancel a timeout we should mark it with REQ_F_FAIL, so
linked requests are cancelled as well, but not queued for further
execution.

Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/fff625b44eeced3a5cae79f60e6acf3fbdf8f990.1631192135.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -1482,6 +1482,8 @@ static void io_kill_timeout(struct io_kiocb *req, int status)
 	struct io_timeout_data *io = req->async_data;
 
 	if (hrtimer_try_to_cancel(&io->timer) != -1) {
+		if (status)
+			req_set_fail(req);
 		atomic_set(&req->ctx->cq_timeouts,
 			atomic_read(&req->ctx->cq_timeouts) + 1);
 		list_del_init(&req->timeout.list);