Commit dc6ce4bc authored by Jackie Liu's avatar Jackie Liu Committed by Jens Axboe
Browse files

io_uring: adjust smp_rmb inside io_cqring_events 



Whenever smp_rmb is required to use io_cqring_events,
keep smp_rmb inside the function io_cqring_events.

Signed-off-by: default avatarJackie Liu <liuyun01@kylinos.cn>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 2bbcd6d3

fs/io_uring.c

+2 −4
Original line number Diff line number Diff line
@@ -2167,6 +2167,8 @@ static int io_ring_submit(struct io_ring_ctx *ctx, unsigned int to_submit) 


static unsigned io_cqring_events(struct io_cq_ring *ring)

{

	/* See comment at the top of this file */

	smp_rmb();

	return READ_ONCE(ring->r.tail) - READ_ONCE(ring->r.head);

}
@@ -2182,8 +2184,6 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, 
	DEFINE_WAIT(wait);

	int ret;



	/* See comment at the top of this file */

	smp_rmb();

	if (io_cqring_events(ring) >= min_events)

		return 0;
@@ -2205,8 +2205,6 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, 
		prepare_to_wait(&ctx->wait, &wait, TASK_INTERRUPTIBLE);



		ret = 0;

		/* See comment at the top of this file */

		smp_rmb();

		if (io_cqring_events(ring) >= min_events)

			break;