bool nvme_change_ctrl_state()

in host/core.c [427:521]

• 90 lines of code
• 26 McCabe index (conditional complexity)

bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl,
		enum nvme_ctrl_state new_state)
{
	enum nvme_ctrl_state old_state;
	unsigned long flags;
	bool changed = false;

	spin_lock_irqsave(&ctrl->lock, flags);

	old_state = ctrl->state;
	switch (new_state) {
	case NVME_CTRL_LIVE:
		switch (old_state) {
		case NVME_CTRL_NEW:
		case NVME_CTRL_RESETTING:
		case NVME_CTRL_CONNECTING:
			changed = true;
			fallthrough;
		default:
			break;
		}
		break;
	case NVME_CTRL_RESETTING:
		switch (old_state) {
		case NVME_CTRL_NEW:
		case NVME_CTRL_LIVE:
			changed = true;
			fallthrough;
		default:
			break;
		}
		break;
	case NVME_CTRL_CONNECTING:
		switch (old_state) {
		case NVME_CTRL_NEW:
		case NVME_CTRL_RESETTING:
			changed = true;
			fallthrough;
		default:
			break;
		}
		break;
	case NVME_CTRL_DELETING:
		switch (old_state) {
		case NVME_CTRL_LIVE:
		case NVME_CTRL_RESETTING:
		case NVME_CTRL_CONNECTING:
			changed = true;
			fallthrough;
		default:
			break;
		}
		break;
	case NVME_CTRL_DELETING_NOIO:
		switch (old_state) {
		case NVME_CTRL_DELETING:
		case NVME_CTRL_DEAD:
			changed = true;
			fallthrough;
		default:
			break;
		}
		break;
	case NVME_CTRL_DEAD:
		switch (old_state) {
		case NVME_CTRL_DELETING:
			changed = true;
			fallthrough;
		default:
			break;
		}
		break;
	default:
		break;
	}

	if (changed) {
		ctrl->state = new_state;
		wake_up_all(&ctrl->state_wq);
	}

	spin_unlock_irqrestore(&ctrl->lock, flags);
	if (!changed)
		return false;

	if (ctrl->state == NVME_CTRL_LIVE) {
		if (old_state == NVME_CTRL_CONNECTING)
			nvme_stop_failfast_work(ctrl);
		nvme_kick_requeue_lists(ctrl);
	} else if (ctrl->state == NVME_CTRL_CONNECTING &&
		old_state == NVME_CTRL_RESETTING) {
		nvme_start_failfast_work(ctrl);
	}
	return changed;
}