Commit 2bbb146d authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: refactor poll update 



Clean up io_poll_update() and unify cancellation paths for remove and
update.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/5937138b6265a1285220e2fab1b28132c1d73ce3.1639605189.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent e840b4ba

fs/io_uring.c

+26 −36
Original line number Diff line number Diff line
@@ -5960,41 +5960,30 @@ static int io_poll_update(struct io_kiocb *req, unsigned int issue_flags) 
	struct io_ring_ctx *ctx = req->ctx;

	struct io_kiocb *preq;

	bool completing;

	int ret;

	int ret2, ret = 0;



	spin_lock(&ctx->completion_lock);

	preq = io_poll_find(ctx, req->poll_update.old_user_data, true);

	if (!preq) {

		ret = -ENOENT;

		goto err;

	}



	if (!req->poll_update.update_events && !req->poll_update.update_user_data) {

		completing = true;

		ret = io_poll_remove_one(preq) ? 0 : -EALREADY;

		goto err;

fail:

		spin_unlock(&ctx->completion_lock);

		goto out;

	}



	io_poll_remove_double(preq);

	/*

	 * Don't allow racy completion with singleshot, as we cannot safely

	 * update those. For multishot, if we're racing with completion, just

	 * let completion re-add it.

	 */

	io_poll_remove_double(preq);

	completing = !__io_poll_remove_one(preq, &preq->poll, false);

	if (completing && (preq->poll.events & EPOLLONESHOT)) {

		ret = -EALREADY;

		goto err;

		goto fail;

	}

	/* we now have a detached poll request. reissue. */

	ret = 0;

err:

	if (ret < 0) {

	spin_unlock(&ctx->completion_lock);

		req_set_fail(req);

		io_req_complete(req, ret);

		return 0;

	}



	if (req->poll_update.update_events || req->poll_update.update_user_data) {

		/* only mask one event flags, keep behavior flags */

		if (req->poll_update.update_events) {

			preq->poll.events &= ~0xffff;
@@ -6003,18 +5992,19 @@ static int io_poll_update(struct io_kiocb *req, unsigned int issue_flags) 
		}

		if (req->poll_update.update_user_data)

			preq->user_data = req->poll_update.new_user_data;

	spin_unlock(&ctx->completion_lock);



		ret2 = io_poll_add(preq, issue_flags);

		/* successfully updated, don't complete poll request */

		if (!ret2)

			goto out;

	}

	req_set_fail(preq);

	io_req_complete(preq, -ECANCELED);

out:

	if (ret < 0)

		req_set_fail(req);

	/* complete update request, we're done with it */

	io_req_complete(req, ret);



	if (!completing) {

		ret = io_poll_add(preq, issue_flags);

		if (ret < 0) {

			req_set_fail(preq);

			io_req_complete(preq, ret);

		}

	}

	return 0;

}