io_uring: use call_rcu_hurry if signaling an eventfd

io_uring uses call_rcu in the case it needs to signal an eventfd as a
result of an eventfd signal, since recursing eventfd signals are not
allowed. This should be calling the new call_rcu_hurry API to not delay
the signal.

Signed-off-by: Dylan Yudaken <dylany@meta.com>

Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Link: https://lore.kernel.org/r/20221215184138.795576-1-dylany@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: Dylan Yudaken

io_uring/io_uring.c

@@ -538,7 +538,7 @@ static void io_eventfd_signal(struct io_ring_ctx *ctx)
 	} else {
 		atomic_inc(&ev_fd->refs);
 		if (!atomic_fetch_or(BIT(IO_EVENTFD_OP_SIGNAL_BIT), &ev_fd->ops))
-			call_rcu(&ev_fd->rcu, io_eventfd_ops);
+			call_rcu_hurry(&ev_fd->rcu, io_eventfd_ops);
 		else
 			atomic_dec(&ev_fd->refs);
 	}