Commit 5b0a6acc authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: simplify task_work func 



Since we don't really use req->task_work anymore, get rid of it together
with the nasty ->func aliasing between ->io_task_work and ->task_work,
and hide ->fallback_node inside of io_task_work.

Also, as task_work is gone now, replace the callback type from
task_work_func_t to a function taking io_kiocb to avoid casting and
simplify code.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 9011bf9a

fs/io_uring.c

+28 −44
Original line number Diff line number Diff line
@@ -785,9 +785,14 @@ struct async_poll { 
	struct io_poll_iocb	*double_poll;

};



typedef void (*io_req_tw_func_t)(struct io_kiocb *req);



struct io_task_work {

	union {

		struct io_wq_work_node	node;

	task_work_func_t	func;

		struct llist_node	fallback_node;

	};

	io_req_tw_func_t		func;

};



enum {
@@ -850,18 +855,13 @@ struct io_kiocb { 


	/* used with ctx->iopoll_list with reads/writes */

	struct list_head		inflight_entry;

	union {

	struct io_task_work		io_task_work;

		struct callback_head	task_work;

	};

	/* for polled requests, i.e. IORING_OP_POLL_ADD and async armed poll */

	struct hlist_node		hash_node;

	struct async_poll		*apoll;

	struct io_wq_work		work;

	const struct cred		*creds;



	struct llist_node		fallback_node;



	/* store used ubuf, so we can prevent reloading */

	struct io_mapped_ubuf		*imu;

};
@@ -1935,7 +1935,7 @@ static void tctx_task_work(struct callback_head *cb) 
				ctx = req->ctx;

				percpu_ref_get(&ctx->refs);

			}

			req->task_work.func(&req->task_work);

			req->io_task_work.func(req);

			node = next;

		}

		if (wq_list_empty(&tctx->task_list)) {
@@ -2006,16 +2006,16 @@ static int io_req_task_work_add(struct io_kiocb *req) 
}



static void io_req_task_work_add_fallback(struct io_kiocb *req,

					  task_work_func_t cb)

					  io_req_tw_func_t cb)

{

	init_task_work(&req->task_work, cb);

	if (llist_add(&req->fallback_node, &req->ctx->fallback_llist))

	req->io_task_work.func = cb;

	if (llist_add(&req->io_task_work.fallback_node,

		      &req->ctx->fallback_llist))

		schedule_delayed_work(&req->ctx->fallback_work, 1);

}



static void io_req_task_cancel(struct callback_head *cb)

static void io_req_task_cancel(struct io_kiocb *req)

{

	struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);

	struct io_ring_ctx *ctx = req->ctx;



	/* ctx is guaranteed to stay alive while we hold uring_lock */
@@ -2024,7 +2024,7 @@ static void io_req_task_cancel(struct callback_head *cb) 
	mutex_unlock(&ctx->uring_lock);

}



static void __io_req_task_submit(struct io_kiocb *req)

static void io_req_task_submit(struct io_kiocb *req)

{

	struct io_ring_ctx *ctx = req->ctx;
@@ -2037,17 +2037,10 @@ static void __io_req_task_submit(struct io_kiocb *req) 
	mutex_unlock(&ctx->uring_lock);

}



static void io_req_task_submit(struct callback_head *cb)

{

	struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);



	__io_req_task_submit(req);

}



static void io_req_task_queue_fail(struct io_kiocb *req, int ret)

{

	req->result = ret;

	req->task_work.func = io_req_task_cancel;

	req->io_task_work.func = io_req_task_cancel;



	if (unlikely(io_req_task_work_add(req)))

		io_req_task_work_add_fallback(req, io_req_task_cancel);
@@ -2055,7 +2048,7 @@ static void io_req_task_queue_fail(struct io_kiocb *req, int ret) 


static void io_req_task_queue(struct io_kiocb *req)

{

	req->task_work.func = io_req_task_submit;

	req->io_task_work.func = io_req_task_submit;



	if (unlikely(io_req_task_work_add(req)))

		io_req_task_queue_fail(req, -ECANCELED);
@@ -2169,18 +2162,11 @@ static inline void io_put_req(struct io_kiocb *req) 
		io_free_req(req);

}



static void io_put_req_deferred_cb(struct callback_head *cb)

{

	struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);



	io_free_req(req);

}



static void io_free_req_deferred(struct io_kiocb *req)

{

	req->task_work.func = io_put_req_deferred_cb;

	req->io_task_work.func = io_free_req;

	if (unlikely(io_req_task_work_add(req)))

		io_req_task_work_add_fallback(req, io_put_req_deferred_cb);

		io_req_task_work_add_fallback(req, io_free_req);

}



static inline void io_put_req_deferred(struct io_kiocb *req, int refs)
@@ -2466,8 +2452,8 @@ static void io_fallback_req_func(struct work_struct *work) 
	struct llist_node *node = llist_del_all(&ctx->fallback_llist);

	struct io_kiocb *req, *tmp;



	llist_for_each_entry_safe(req, tmp, node, fallback_node)

		req->task_work.func(&req->task_work);

	llist_for_each_entry_safe(req, tmp, node, io_task_work.fallback_node)

		req->io_task_work.func(req);

}



static void __io_complete_rw(struct io_kiocb *req, long res, long res2,
@@ -4835,7 +4821,7 @@ struct io_poll_table { 
};



static int __io_async_wake(struct io_kiocb *req, struct io_poll_iocb *poll,

			   __poll_t mask, task_work_func_t func)

			   __poll_t mask, io_req_tw_func_t func)

{

	int ret;
@@ -4848,7 +4834,7 @@ static int __io_async_wake(struct io_kiocb *req, struct io_poll_iocb *poll, 
	list_del_init(&poll->wait.entry);



	req->result = mask;

	req->task_work.func = func;

	req->io_task_work.func = func;



	/*

	 * If this fails, then the task is exiting. When a task exits, the
@@ -4945,9 +4931,8 @@ static bool io_poll_complete(struct io_kiocb *req, __poll_t mask) 
	return !(flags & IORING_CQE_F_MORE);

}



static void io_poll_task_func(struct callback_head *cb)

static void io_poll_task_func(struct io_kiocb *req)

{

	struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);

	struct io_ring_ctx *ctx = req->ctx;

	struct io_kiocb *nxt;
@@ -4969,7 +4954,7 @@ static void io_poll_task_func(struct callback_head *cb) 
		if (done) {

			nxt = io_put_req_find_next(req);

			if (nxt)

				__io_req_task_submit(nxt);

				io_req_task_submit(nxt);

		}

	}

}
@@ -5078,9 +5063,8 @@ static void io_async_queue_proc(struct file *file, struct wait_queue_head *head, 
	__io_queue_proc(&apoll->poll, pt, head, &apoll->double_poll);

}



static void io_async_task_func(struct callback_head *cb)

static void io_async_task_func(struct io_kiocb *req)

{

	struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);

	struct async_poll *apoll = req->apoll;

	struct io_ring_ctx *ctx = req->ctx;
@@ -5096,7 +5080,7 @@ static void io_async_task_func(struct callback_head *cb) 
	spin_unlock_irq(&ctx->completion_lock);



	if (!READ_ONCE(apoll->poll.canceled))

		__io_req_task_submit(req);

		io_req_task_submit(req);

	else

		io_req_complete_failed(req, -ECANCELED);

}
@@ -8817,7 +8801,7 @@ static void io_ring_exit_work(struct work_struct *work) 
	/*

	 * Some may use context even when all refs and requests have been put,

	 * and they are free to do so while still holding uring_lock or

	 * completion_lock, see __io_req_task_submit(). Apart from other work,

	 * completion_lock, see io_req_task_submit(). Apart from other work,

	 * this lock/unlock section also waits them to finish.

	 */

	mutex_lock(&ctx->uring_lock);