scsi: lpfc: Fix driver not recovering NVME rports during target link faults

During target-side port faults, the driver would not recover all target
port logins. This resulted in a loss of nvme device discovery.

The driver is coded to wait for all GID_FT requests to complete before
restarting discovery. A fault is seen where the outstanding GIT_FT
counts are not properly decremented, thus discovery would never
start. Another fault was found in the clearing of the gidft_inp counter
that would be skipped in this condition. And a third fault found with
lpfc_nvme_register_port that would remove a reverence on the ndlp which
then allows a node swap on a port address change to prematurely remove
the reference and release the ndlp.

The following changes are made:

 - Correct the decrementing of the outstanding GID_FT counters.

 - In RSCN handling, no longer zero the counter before calling to issue
   another GID_FT.

 - No longer remove the reference on the dlp when the ndlp->nrport value
   is not yet null.
Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/lpfc/lpfc_ct.c

@@ -691,6 +691,11 @@ lpfc_cmpl_ct_cmd_gid_ft(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb,
 		vport->fc_flag &= ~FC_RSCN_DEFERRED;
 		spin_unlock_irq(shost->host_lock);
 
+		/* This is a GID_FT completing so the gidft_inp counter was
+		 * incremented before the GID_FT was issued to the wire.
+		 */
+		vport->gidft_inp--;
+
 		/*
 		 * Skip processing the NS response
 		 * Re-issue the NS cmd

drivers/scsi/lpfc/lpfc_els.c

@@ -6268,7 +6268,6 @@ lpfc_els_handle_rscn(struct lpfc_vport *vport)
 		 * flush the RSCN.  Otherwise, the outstanding requests
 		 * need to complete.
 		 */
-		vport->gidft_inp = 0;
 		if (lpfc_issue_gidft(vport) > 0)
 			return 1;
 	} else {

drivers/scsi/lpfc/lpfc_nvme.c

@@ -2721,8 +2721,16 @@ lpfc_nvme_register_port(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp)
 			spin_unlock_irq(&vport->phba->hbalock);
 			rport->ndlp = NULL;
 			rport->remoteport = NULL;
-			if (prev_ndlp)
-				lpfc_nlp_put(ndlp);
+
+			/* Reference only removed if previous NDLP is no longer
+			 * active. It might be just a swap and removing the
+			 * reference would cause a premature cleanup.
+			 */
+			if (prev_ndlp && prev_ndlp != ndlp) {
+				if ((!NLP_CHK_NODE_ACT(prev_ndlp)) ||
+				    (!prev_ndlp->nrport))
+					lpfc_nlp_put(prev_ndlp);
+			}
 		}
 
 		/* Clean bind the rport to the ndlp. */