Commit e83acd7d authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: avoid taking ctx refs for task-cancel 



Don't bother to take a ctx->refs for io_req_task_cancel() because it
take uring_lock before putting a request, and the context is promised to
stay alive until unlock happens.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent d434405a

fs/io_uring.c

+1 −3
Original line number Diff line number Diff line
@@ -1985,10 +1985,10 @@ static void io_req_task_cancel(struct callback_head *cb) 
	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 */

	mutex_lock(&ctx->uring_lock);

	__io_req_task_cancel(req, req->result);

	mutex_unlock(&ctx->uring_lock);

	percpu_ref_put(&ctx->refs);

}



static void __io_req_task_submit(struct io_kiocb *req)
@@ -2019,14 +2019,12 @@ static void io_req_task_queue(struct io_kiocb *req) 
	ret = io_req_task_work_add(req);

	if (unlikely(ret)) {

		req->result = -ECANCELED;

		percpu_ref_get(&req->ctx->refs);

		io_req_task_work_add_fallback(req, io_req_task_cancel);

	}

}



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

{

	percpu_ref_get(&req->ctx->refs);

	req->result = ret;

	req->task_work.func = io_req_task_cancel;