lpfc: nvmet: Add support for NVME LS request hosthandle

As the nvmet layer does not have the concept of a remoteport object, which
can be used to identify the entity on the other end of the fabric that is
to receive an LS, the hosthandle was introduced. The driver passes the
hosthandle, a value representative of the remote port, with a ls request
receive. The LS request will create the association. The transport will
remember the hosthandle for the association, and if there is a need to
initiate a LS request to the remote port for the association, the
hosthandle will be used. When the driver loses connectivity with the
remote port, it needs to notify the transport that the hosthandle is no
longer valid, allowing the transport to terminate associations related to
the hosthandle.

This patch adds support to the driver for the hosthandle. The driver will
use the ndlp pointer of the remote port for the hosthandle in calls to
nvmet_fc_rcv_ls_req(). The discovery engine is updated to invalidate the
hosthandle whenever connectivity with the remote port is lost.

Signed-off-by: Paul Ely <[e-mail]>
Signed-off-by: James Smart <[e-mail]>
Reviewed-by: Hannes Reinecke <[e-mail]>
Signed-off-by: Christoph Hellwig <[e-mail]>
Signed-off-by: Jens Axboe <[e-mail]>

drivers/scsi/lpfc/lpfc_crtn.h

···
 				struct rqb_dmabuf *nvmebuf, uint64_t isr_ts,
 				uint8_t cqflag);
 void lpfc_nvme_mod_param_dep(struct lpfc_hba *phba);
+void lpfc_nvmet_invalidate_host(struct lpfc_hba *phba,
+			struct lpfc_nodelist *ndlp);
 void lpfc_nvme_abort_fcreq_cmpl(struct lpfc_hba *phba,
 				struct lpfc_iocbq *cmdiocb,
 				struct lpfc_wcqe_complete *abts_cmpl);

drivers/scsi/lpfc/lpfc_hbadisc.c

···
 		if ((phba->sli_rev < LPFC_SLI_REV4) &&
 		    (!remove && ndlp->nlp_type & NLP_FABRIC))
 			continue;
+
+		/* Notify transport of connectivity loss to trigger cleanup. */
+		if (phba->nvmet_support &&
+		    ndlp->nlp_state == NLP_STE_UNMAPPED_NODE)
+			lpfc_nvmet_invalidate_host(phba, ndlp);
+
 		lpfc_disc_state_machine(vport, ndlp, NULL,
 					remove
 					? NLP_EVT_DEVICE_RM

drivers/scsi/lpfc/lpfc_nportdisc.c

···
 					 (unsigned long long)
 					 wwn_to_u64(sp->portName.u.wwn));
 
+		/* Notify transport of connectivity loss to trigger cleanup. */
+		if (phba->nvmet_support &&
+		    ndlp->nlp_state == NLP_STE_UNMAPPED_NODE)
+			lpfc_nvmet_invalidate_host(phba, ndlp);
+
 		ndlp->nlp_prev_state = ndlp->nlp_state;
 		/* rport needs to be unregistered first */
 		lpfc_nlp_set_state(vport, ndlp, NLP_STE_NPR_NODE);
···
 		lpfc_els_rsp_acc(vport, ELS_CMD_PRLO, cmdiocb, ndlp, NULL);
 	else
 		lpfc_els_rsp_acc(vport, ELS_CMD_ACC, cmdiocb, ndlp, NULL);
+
+	/* Notify transport of connectivity loss to trigger cleanup. */
+	if (phba->nvmet_support &&
+	    ndlp->nlp_state == NLP_STE_UNMAPPED_NODE)
+		lpfc_nvmet_invalidate_host(phba, ndlp);
+
 	if (ndlp->nlp_DID == Fabric_DID) {
 		if (vport->port_state <= LPFC_FDISC)
 			goto out;

drivers/scsi/lpfc/lpfc_nvme.h

···
 #define LPFC_NVMET_WAIT_TMO		(5 * MSEC_PER_SEC)
 
 /* Used for NVME Target */
+#define LPFC_NVMET_INV_HOST_ACTIVE      1
+
 struct lpfc_nvmet_tgtport {
 	struct lpfc_hba *phba;
 	struct completion *tport_unreg_cmp;
+	atomic_t state;		/* tracks nvmet hosthandle invalidation */
 
 	/* Stats counters - lpfc_nvmet_unsol_ls_buffer */
 	atomic_t rcv_ls_req_in;

drivers/scsi/lpfc/lpfc_nvmet.c

···
 }
 
 static void
+lpfc_nvmet_host_release(void *hosthandle)
+{
+	struct lpfc_nodelist *ndlp = hosthandle;
+	struct lpfc_hba *phba = NULL;
+	struct lpfc_nvmet_tgtport *tgtp;
+
+	phba = ndlp->phba;
+	if (!phba->targetport || !phba->targetport->private)
+		return;
+
+	lpfc_printf_log(phba, KERN_ERR, LOG_NVME,
+			"6202 NVMET XPT releasing hosthandle x%px\n",
+			hosthandle);
+	tgtp = (struct lpfc_nvmet_tgtport *)phba->targetport->private;
+	atomic_set(&tgtp->state, 0);
+}
+
+static void
 lpfc_nvmet_discovery_event(struct nvmet_fc_target_port *tgtport)
 {
 	struct lpfc_nvmet_tgtport *tgtp;
···
 	.fcp_req_release = lpfc_nvmet_xmt_fcp_release,
 	.defer_rcv	= lpfc_nvmet_defer_rcv,
 	.discovery_event = lpfc_nvmet_discovery_event,
+	.host_release   = lpfc_nvmet_host_release,
 
 	.max_hw_queues  = 1,
 	.max_sgl_segments = LPFC_NVMET_DEFAULT_SEGS,
···
 
 	atomic_inc(&tgtp->rcv_ls_req_in);
 
-	rc = nvmet_fc_rcv_ls_req(phba->targetport, NULL, &axchg->ls_rsp,
+	/*
+	 * Driver passes the ndlp as the hosthandle argument allowing
+	 * the transport to generate LS requests for any associateions
+	 * that are created.
+	 */
+	rc = nvmet_fc_rcv_ls_req(phba->targetport, axchg->ndlp, &axchg->ls_rsp,
 				 axchg->payload, axchg->size);
 
 	lpfc_printf_log(phba, KERN_INFO, LOG_NVME_DISC,
···
 	lpfc_printf_log(phba, KERN_ERR, LOG_NVME_ABTS,
 			"6056 Failed to Issue ABTS. Status x%x\n", rc);
 	return 0;
+}
+
+/**
+ * lpfc_nvmet_invalidate_host
+ *
+ * @phba - pointer to the driver instance bound to an adapter port.
+ * @ndlp - pointer to an lpfc_nodelist type
+ *
+ * This routine upcalls the nvmet transport to invalidate an NVME
+ * host to which this target instance had active connections.
+ */
+void
+lpfc_nvmet_invalidate_host(struct lpfc_hba *phba, struct lpfc_nodelist *ndlp)
+{
+	struct lpfc_nvmet_tgtport *tgtp;
+
+	lpfc_printf_log(phba, KERN_INFO, LOG_NVME | LOG_NVME_ABTS,
+			"6203 Invalidating hosthandle x%px\n",
+			ndlp);
+
+	tgtp = (struct lpfc_nvmet_tgtport *)phba->targetport->private;
+	atomic_set(&tgtp->state, LPFC_NVMET_INV_HOST_ACTIVE);
+
+#if (IS_ENABLED(CONFIG_NVME_TARGET_FC))
+	/* Need to get the nvmet_fc_target_port pointer here.*/
+	nvmet_fc_invalidate_host(phba->targetport, ndlp);
+#endif
 }