
static int io_sq_offload_create(struct io_ring_ctx *ctx,
				struct io_uring_params *p)
{
	int ret;

	/* Retain compatibility with failing for an invalid attach attempt */
	if ((ctx->flags & (IORING_SETUP_ATTACH_WQ | IORING_SETUP_SQPOLL)) ==
				IORING_SETUP_ATTACH_WQ) {
		struct fd f;

		f = fdget(p->wq_fd);
		if (!f.file)
			return -ENXIO;
		fdput(f);
		if (f.file->f_op != &io_uring_fops)
			return -EINVAL;
	}
	if (ctx->flags & IORING_SETUP_SQPOLL) {
		struct task_struct *tsk;
		struct io_sq_data *sqd;
		bool attached;

		sqd = io_get_sq_data(p, &attached);
		if (IS_ERR(sqd)) {
			ret = PTR_ERR(sqd);
			goto err;
		}

		ctx->sq_creds = get_current_cred();
		ctx->sq_data = sqd;
		ctx->sq_thread_idle = msecs_to_jiffies(p->sq_thread_idle);
		if (!ctx->sq_thread_idle)
			ctx->sq_thread_idle = HZ;

		io_sq_thread_park(sqd);
		list_add(&ctx->sqd_list, &sqd->ctx_list);
		io_sqd_update_thread_idle(sqd);
		/* don't attach to a dying SQPOLL thread, would be racy */
		ret = (attached && !sqd->thread) ? -ENXIO : 0;
		io_sq_thread_unpark(sqd);

		if (ret < 0)
			goto err;
		if (attached)
			return 0;

		if (p->flags & IORING_SETUP_SQ_AFF) {
			int cpu = p->sq_thread_cpu;

			ret = -EINVAL;
			if (cpu >= nr_cpu_ids || !cpu_online(cpu))
				goto err_sqpoll;
			sqd->sq_cpu = cpu;
		} else {
			sqd->sq_cpu = -1;
		}

		sqd->task_pid = current->pid;
		sqd->task_tgid = current->tgid;
		tsk = create_io_thread(io_sq_thread, sqd, NUMA_NO_NODE);
		if (IS_ERR(tsk)) {
			ret = PTR_ERR(tsk);
			goto err_sqpoll;
		}

		sqd->thread = tsk;
		ret = io_uring_alloc_task_context(tsk, ctx);
		wake_up_new_task(tsk);
		if (ret)
			goto err;
	} else if (p->flags & IORING_SETUP_SQ_AFF) {
		/* Can't have SQ_AFF without SQPOLL */
		ret = -EINVAL;
		goto err;
	}

	return 0;
err_sqpoll:
	complete(&ctx->sq_data->exited);
err:
	io_sq_thread_finish(ctx);
	return ret;

static int io_sq_offload_create(struct io_ring_ctx *ctx,
				struct io_uring_params *p)
{
	int ret;

	 
	if ((ctx->flags & (IORING_SETUP_ATTACH_WQ | IORING_SETUP_SQPOLL)) ==
				IORING_SETUP_ATTACH_WQ) {
		struct fd f;

		f = fdget(p->wq_fd);
		if (!f.file)
			return -ENXIO;
		fdput(f);
		if (f.file->f_op != &io_uring_fops)
			return -EINVAL;
	}
	if (ctx->flags & IORING_SETUP_SQPOLL) {
		struct task_struct *tsk;
		struct io_sq_data *sqd;
		bool attached;

		sqd = io_get_sq_data(p, &attached);
		if (IS_ERR(sqd)) {
			ret = PTR_ERR(sqd);
			goto err;
		}

		ctx->sq_creds = get_current_cred();
		ctx->sq_data = sqd;
		ctx->sq_thread_idle = msecs_to_jiffies(p->sq_thread_idle);
		if (!ctx->sq_thread_idle)
			ctx->sq_thread_idle = HZ;

		io_sq_thread_park(sqd);
		list_add(&ctx->sqd_list, &sqd->ctx_list);
		io_sqd_update_thread_idle(sqd);
		 
		ret = (attached && !sqd->thread) ? -ENXIO : 0;
		io_sq_thread_unpark(sqd);

		if (ret < 0)
			goto err;
		if (attached)
			return 0;

		if (p->flags & IORING_SETUP_SQ_AFF) {
			int cpu = p->sq_thread_cpu;

			ret = -EINVAL;
			if (cpu >= nr_cpu_ids || !cpu_online(cpu))
				goto err_sqpoll;
			sqd->sq_cpu = cpu;
		} else {
			sqd->sq_cpu = -1;
		}

		sqd->task_pid = current->pid;
		sqd->task_tgid = current->tgid;
		tsk = create_io_thread(io_sq_thread, sqd, NUMA_NO_NODE);
		if (IS_ERR(tsk)) {
			ret = PTR_ERR(tsk);
			goto err_sqpoll;
		}

		sqd->thread = tsk;
		ret = io_uring_alloc_task_context(tsk, ctx);
		wake_up_new_task(tsk);
		if (ret)
			goto err;
	} else if (p->flags & IORING_SETUP_SQ_AFF) {
		 
		ret = -EINVAL;
		goto err;
	}

	return 0;
err_sqpoll:
	complete(&ctx->sq_data->exited);
err:
	io_sq_thread_finish(ctx);
	return ret;