Commit fbf23849 authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring: make IORING_OP_CANCEL_ASYNC deferrable 



If we defer this command as part of a link, we have to make sure that
the SQE data has been read upfront. Integrate the async cancel op into
the prep handling to make it safe for SQE reuse.

Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 0969e783

fs/io_uring.c

+28 −4
Original line number Diff line number Diff line
@@ -321,6 +321,11 @@ struct io_sync { 
	int				flags;

};



struct io_cancel {

	struct file			*file;

	u64				addr;

};



struct io_async_connect {

	struct sockaddr_storage		address;

};
@@ -362,6 +367,7 @@ struct io_kiocb { 
		struct io_poll_iocb	poll;

		struct io_accept	accept;

		struct io_sync		sync;

		struct io_cancel	cancel;

	};



	const struct io_uring_sqe	*sqe;
@@ -3018,18 +3024,33 @@ static void io_async_find_and_cancel(struct io_ring_ctx *ctx, 
	io_put_req_find_next(req, nxt);

}



static int io_async_cancel(struct io_kiocb *req, struct io_kiocb **nxt)

static int io_async_cancel_prep(struct io_kiocb *req)

{

	const struct io_uring_sqe *sqe = req->sqe;

	struct io_ring_ctx *ctx = req->ctx;



	if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))

	if (req->flags & REQ_F_PREPPED)

		return 0;

	if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))

		return -EINVAL;

	if (sqe->flags || sqe->ioprio || sqe->off || sqe->len ||

	    sqe->cancel_flags)

		return -EINVAL;



	io_async_find_and_cancel(ctx, req, READ_ONCE(sqe->addr), nxt, 0);

	req->flags |= REQ_F_PREPPED;

	req->cancel.addr = READ_ONCE(sqe->addr);

	return 0;

}



static int io_async_cancel(struct io_kiocb *req, struct io_kiocb **nxt)

{

	struct io_ring_ctx *ctx = req->ctx;

	int ret;



	ret = io_async_cancel_prep(req);

	if (ret)

		return ret;



	io_async_find_and_cancel(ctx, req, req->cancel.addr, nxt, 0);

	return 0;

}
@@ -3087,6 +3108,9 @@ static int io_req_defer_prep(struct io_kiocb *req) 
	case IORING_OP_TIMEOUT:

		ret = io_timeout_prep(req, io, false);

		break;

	case IORING_OP_ASYNC_CANCEL:

		ret = io_async_cancel_prep(req);

		break;

	case IORING_OP_LINK_TIMEOUT:

		ret = io_timeout_prep(req, io, true);

		break;