scsi: lpfc: Update PRLO handling in direct attached topology

A kref imbalance occurs when handling an unsolicited PRLO in direct
attached topology.

Rework PRLO rcv handling when in MAPPED state.  Save the state that we were
handling a PRLO by setting nlp_last_elscmd to ELS_CMD_PRLO.  Then in the
lpfc_cmpl_els_logo_acc() completion routine, manually restart discovery.
By issuing the PLOGI, which nlp_gets, before nlp_put at the end of the
lpfc_cmpl_els_logo_acc() routine, we are saving us from a final nlp_put.
And, we are still allowing the unreg_rpi to happen.

Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Link: https://lore.kernel.org/r/20240726231512.92867-7-justintee8345@gmail.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

2 files changed, 36 insertions, 13 deletions

diff --git a/drivers/scsi/lpfc/lpfc_els.c b/drivers/scsi/lpfc/lpfc_els.c
index b5a8d050419a..de0ec945d2f1 100644
--- a/drivers/scsi/lpfc/lpfc_els.c
+++ b/drivers/scsi/lpfc/lpfc_els.c
@@ -5246,9 +5246,10 @@ lpfc_cmpl_els_logo_acc(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb,
 	/* ACC to LOGO completes to NPort <nlp_DID> */
 	lpfc_printf_vlog(vport, KERN_INFO, LOG_ELS,
 			 "0109 ACC to LOGO completes to NPort x%x refcnt %d "
-			 "Data: x%x x%x x%x\n",
-			 ndlp->nlp_DID, kref_read(&ndlp->kref), ndlp->nlp_flag,
-			 ndlp->nlp_state, ndlp->nlp_rpi);
+			 "last els x%x Data: x%x x%x x%x\n",
+			 ndlp->nlp_DID, kref_read(&ndlp->kref),
+			 ndlp->nlp_last_elscmd, ndlp->nlp_flag, ndlp->nlp_state,
+			 ndlp->nlp_rpi);
 
 	/* This clause allows the LOGO ACC to complete and free resources
 	 * for the Fabric Domain Controller.  It does deliberately skip
@@ -5260,18 +5261,22 @@ lpfc_cmpl_els_logo_acc(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb,
 		goto out;
 
 	if (ndlp->nlp_state == NLP_STE_NPR_NODE) {
-		/* If PLOGI is being retried, PLOGI completion will cleanup the
-		 * node. The NLP_NPR_2B_DISC flag needs to be retained to make
-		 * progress on nodes discovered from last RSCN.
-		 */
-		if ((ndlp->nlp_flag & NLP_DELAY_TMO) &&
-		    (ndlp->nlp_last_elscmd == ELS_CMD_PLOGI))
-			goto out;
-
 		if (ndlp->nlp_flag & NLP_RPI_REGISTERED)
 			lpfc_unreg_rpi(vport, ndlp);
 
+		/* If came from PRLO, then PRLO_ACC is done.
+		 * Start rediscovery now.
+		 */
+		if (ndlp->nlp_last_elscmd == ELS_CMD_PRLO) {
+			spin_lock_irq(&ndlp->lock);
+			ndlp->nlp_flag |= NLP_NPR_2B_DISC;
+			spin_unlock_irq(&ndlp->lock);
+			ndlp->nlp_prev_state = ndlp->nlp_state;
+			lpfc_nlp_set_state(vport, ndlp, NLP_STE_PLOGI_ISSUE);
+			lpfc_issue_els_plogi(vport, ndlp->nlp_DID, 0);
+		}
 	}
+
  out:
 	/*
 	 * The driver received a LOGO from the rport and has ACK'd it.
diff --git a/drivers/scsi/lpfc/lpfc_nportdisc.c b/drivers/scsi/lpfc/lpfc_nportdisc.c
index f6a53446e57f..4574716c8764 100644
--- a/drivers/scsi/lpfc/lpfc_nportdisc.c
+++ b/drivers/scsi/lpfc/lpfc_nportdisc.c
@@ -2652,8 +2652,26 @@ lpfc_rcv_prlo_mapped_node(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
 	/* flush the target */
 	lpfc_sli_abort_iocb(vport, ndlp->nlp_sid, 0, LPFC_CTX_TGT);
 
-	/* Treat like rcv logo */
-	lpfc_rcv_logo(vport, ndlp, cmdiocb, ELS_CMD_PRLO);
+	/* Send PRLO_ACC */
+	spin_lock_irq(&ndlp->lock);
+	ndlp->nlp_flag |= NLP_LOGO_ACC;
+	spin_unlock_irq(&ndlp->lock);
+	lpfc_els_rsp_acc(vport, ELS_CMD_PRLO, cmdiocb, ndlp, NULL);
+
+	/* Save ELS_CMD_PRLO as the last elscmd and then set to NPR.
+	 * lpfc_cmpl_els_logo_acc is expected to restart discovery.
+	 */
+	ndlp->nlp_last_elscmd = ELS_CMD_PRLO;
+	ndlp->nlp_prev_state = ndlp->nlp_state;
+
+	lpfc_printf_vlog(vport, KERN_INFO, LOG_NODE | LOG_ELS | LOG_DISCOVERY,
+			 "3422 DID x%06x nflag x%x lastels x%x ref cnt %u\n",
+			 ndlp->nlp_DID, ndlp->nlp_flag,
+			 ndlp->nlp_last_elscmd,
+			 kref_read(&ndlp->kref));
+
+	lpfc_nlp_set_state(vport, ndlp, NLP_STE_NPR_NODE);
+
 	return ndlp->nlp_state;
 }