Commit 62ca1710 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Zheng Zengkai
Browse files

io_uring: deduplicate failing task_work_add 

mainline inclusion
from mainline-5.12-rc1
commit eab30c4d
category: bugfix
bugzilla: 182869 https://gitee.com/openeuler/kernel/issues/I4DDEL

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=eab30c4d20dc761d463445e5130421863ff81505



---------------------------

When io_req_task_work_add() fails, the request will be cancelled by
enqueueing via task_works of io-wq. Extract a function for that.

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

Conflicts:
	fs/io_uring.c
	[ 355fb9e2("io_uring: remove 'twa_signal_ok' deadlock
	  work-around") is not applied. ]

Signed-off-by: default avatarZhihao Cheng <chengzhihao1@huawei.com>
Reviewed-by: default avatarZhang Yi <yi.zhang@huawei.com>

Signed-off-by: default avatarChen Jun <chenjun102@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent 98d3ad1d

fs/io_uring.c

+17 −29
Original line number Diff line number Diff line
@@ -2056,6 +2056,16 @@ static int io_req_task_work_add(struct io_kiocb *req, bool twa_signal_ok) 
	return ret;

}



static void io_req_task_work_add_fallback(struct io_kiocb *req,

					  void (*cb)(struct callback_head *))

{

	struct task_struct *tsk = io_wq_get_task(req->ctx->io_wq);



	init_task_work(&req->task_work, cb);

	task_work_add(tsk, &req->task_work, TWA_NONE);

	wake_up_process(tsk);

}



static void __io_req_task_cancel(struct io_kiocb *req, int error)

{

	struct io_ring_ctx *ctx = req->ctx;
@@ -2111,14 +2121,8 @@ static void io_req_task_queue(struct io_kiocb *req) 
	percpu_ref_get(&req->ctx->refs);



	ret = io_req_task_work_add(req, true);

	if (unlikely(ret)) {

		struct task_struct *tsk;



		init_task_work(&req->task_work, io_req_task_cancel);

		tsk = io_wq_get_task(req->ctx->io_wq);

		task_work_add(tsk, &req->task_work, TWA_NONE);

		wake_up_process(tsk);

	}

	if (unlikely(ret))

		io_req_task_work_add_fallback(req, io_req_task_cancel);

}



static void io_queue_next(struct io_kiocb *req)
@@ -2237,13 +2241,8 @@ static void io_free_req_deferred(struct io_kiocb *req) 


	init_task_work(&req->task_work, io_put_req_deferred_cb);

	ret = io_req_task_work_add(req, true);

	if (unlikely(ret)) {

		struct task_struct *tsk;



		tsk = io_wq_get_task(req->ctx->io_wq);

		task_work_add(tsk, &req->task_work, TWA_NONE);

		wake_up_process(tsk);

	}

	if (unlikely(ret))

		io_req_task_work_add_fallback(req, io_put_req_deferred_cb);

}



static inline void io_put_req_deferred(struct io_kiocb *req, int refs)
@@ -3343,15 +3342,8 @@ static int io_async_buf_func(struct wait_queue_entry *wait, unsigned mode, 
	/* submit ref gets dropped, acquire a new one */

	refcount_inc(&req->refs);

	ret = io_req_task_work_add(req, true);

	if (unlikely(ret)) {

		struct task_struct *tsk;



		/* queue just for cancelation */

		init_task_work(&req->task_work, io_req_task_cancel);

		tsk = io_wq_get_task(req->ctx->io_wq);

		task_work_add(tsk, &req->task_work, TWA_NONE);

		wake_up_process(tsk);

	}

	if (unlikely(ret))

		io_req_task_work_add_fallback(req, io_req_task_cancel);

	return 1;

}
@@ -4961,12 +4953,8 @@ static int __io_async_wake(struct io_kiocb *req, struct io_poll_iocb *poll, 
	 */

	ret = io_req_task_work_add(req, twa_signal_ok);

	if (unlikely(ret)) {

		struct task_struct *tsk;



		WRITE_ONCE(poll->canceled, true);

		tsk = io_wq_get_task(req->ctx->io_wq);

		task_work_add(tsk, &req->task_work, TWA_NONE);

		wake_up_process(tsk);

		io_req_task_work_add_fallback(req, func);

	}

	return 1;

}