nvme-fabrics: fix and refine state checks in __nvmf_check_ready

bool __nvmf_check_ready(struct nvme_ctrl *ctrl, struct request *rq,

		bool queue_live)

{

	struct nvme_command *cmd = nvme_req(rq)->cmd;

	struct nvme_request *req = nvme_req(rq);

	switch (ctrl->state) {

	case NVME_CTRL_NEW:

	case NVME_CTRL_CONNECTING:

	case NVME_CTRL_DELETING:

	/*

		 * If queue is live, allow only commands that are internally

		 * generated pass through.  These are commands on the admin

		 * queue to initialize the controller. This will reject any

		 * ioctl admin cmds received while initializing.

	 * If we are in some state of setup or teardown only allow

	 * internally generated commands.

	 */

		if (queue_live && !(nvme_req(rq)->flags & NVME_REQ_USERCMD))

			return true;

	if (!blk_rq_is_passthrough(rq) || (req->flags & NVME_REQ_USERCMD))

		return false;

	/*

		 * If the queue is not live, allow only a connect command.  This

		 * will reject any ioctl admin cmd as well as initialization

		 * commands if the controller reverted the queue to non-live.

	 * Only allow commands on a live queue, except for the connect command,

	 * which is require to set the queue live in the appropinquate states.

	 */

		if (!queue_live && blk_rq_is_passthrough(rq) &&

		     cmd->common.opcode == nvme_fabrics_command &&

		     cmd->fabrics.fctype == nvme_fabrics_type_connect)

	switch (ctrl->state) {

	case NVME_CTRL_NEW:

	case NVME_CTRL_CONNECTING:

		if (req->cmd->common.opcode == nvme_fabrics_command &&

		    req->cmd->fabrics.fctype == nvme_fabrics_type_connect)

			return true;

		return false;

		break;

	default:

		break;

	case NVME_CTRL_DEAD:

		return false;

	}

	return queue_live;

}

EXPORT_SYMBOL_GPL(__nvmf_check_ready);