Commit f6da4fee authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring/eventfd: open code io_eventfd_grab() 



io_eventfd_grab() doesn't help wit understanding the path, it'll be
simpler to keep the helper open coded.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/5cb53ce3876c2819db9e8055cf41dca4398521db.1745493845.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent da01f60f

io_uring/eventfd.c

+10 −30
Original line number Diff line number Diff line
@@ -65,38 +65,11 @@ static bool __io_eventfd_signal(struct io_ev_fd *ev_fd) 


/*

 * Trigger if eventfd_async isn't set, or if it's set and the caller is

 * an async worker. If ev_fd isn't valid, obviously return false.

 * an async worker.

 */

static bool io_eventfd_trigger(struct io_ev_fd *ev_fd)

{

	if (ev_fd)

	return !ev_fd->eventfd_async || io_wq_current_is_worker();

	return false;

}



/*

 * On success, returns with an ev_fd reference grabbed and the RCU read

 * lock held.

 */

static struct io_ev_fd *io_eventfd_grab(struct io_ring_ctx *ctx)

{

	struct io_ev_fd *ev_fd;



	/*

	 * rcu_dereference ctx->io_ev_fd once and use it for both for checking

	 * and eventfd_signal

	 */

	ev_fd = rcu_dereference(ctx->io_ev_fd);



	/*

	 * Check again if ev_fd exists in case an io_eventfd_unregister call

	 * completed between the NULL check of ctx->io_ev_fd at the start of

	 * the function and rcu_read_lock.

	 */

	if (io_eventfd_trigger(ev_fd) && refcount_inc_not_zero(&ev_fd->refs))

		return ev_fd;



	return NULL;

}



void io_eventfd_signal(struct io_ring_ctx *ctx, bool cqe_event)
@@ -108,9 +81,16 @@ void io_eventfd_signal(struct io_ring_ctx *ctx, bool cqe_event) 
		return;



	guard(rcu)();

	ev_fd = io_eventfd_grab(ctx);

	ev_fd = rcu_dereference(ctx->io_ev_fd);

	/*

	 * Check again if ev_fd exists in case an io_eventfd_unregister call

	 * completed between the NULL check of ctx->io_ev_fd at the start of

	 * the function and rcu_read_lock.

	 */

	if (!ev_fd)

		return;

	if (!io_eventfd_trigger(ev_fd) || !refcount_inc_not_zero(&ev_fd->refs))

		return;



	if (cqe_event) {

		/*