[PATCH 4/6] lpfc: Handle duplicate D_IDs in ndlp search-by D_ID routine

[Justin Tee <justintee8345@gmail.com>]

After a port swap between separate fabrics, there may be multiple nodes in
the vport's fc_nodes list with the same fabric well known address.
Duplication is temporary and eventually resolves itself after dev_loss_tmo
expires, but nameserver queries may still occur before dev_loss_tmo.  This
possibly results in returning stale fabric ndlp objects.  Fix by adding an
nlp_state check to ensure the ndlp search routine returns the correct newer
allocated ndlp fabric object.

Signed-off-by: Justin Tee <justin.tee@broadcom.com>
---
 drivers/scsi/lpfc/lpfc_hbadisc.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_hbadisc.c b/drivers/scsi/lpfc/lpfc_hbadisc.c
index 2dfcf1db5395..07cd611f34bd 100644
--- a/drivers/scsi/lpfc/lpfc_hbadisc.c
+++ b/drivers/scsi/lpfc/lpfc_hbadisc.c
@@ -5570,6 +5570,7 @@ static struct lpfc_nodelist *
 __lpfc_findnode_did(struct lpfc_vport *vport, uint32_t did)
 {
 	struct lpfc_nodelist *ndlp;
+	struct lpfc_nodelist *np = NULL;
 	uint32_t data1;
 
 	list_for_each_entry(ndlp, &vport->fc_nodes, nlp_listp) {
@@ -5584,14 +5585,20 @@ __lpfc_findnode_did(struct lpfc_vport *vport, uint32_t did)
 					 ndlp, ndlp->nlp_DID,
 					 ndlp->nlp_flag, data1, ndlp->nlp_rpi,
 					 ndlp->active_rrqs_xri_bitmap);
-			return ndlp;
+
+			/* Check for new or potentially stale node */
+			if (ndlp->nlp_state != NLP_STE_UNUSED_NODE)
+				return ndlp;
+			np = ndlp;
 		}
 	}
 
-	/* FIND node did <did> NOT FOUND */
-	lpfc_printf_vlog(vport, KERN_INFO, LOG_NODE,
-			 "0932 FIND node did x%x NOT FOUND.\n", did);
-	return NULL;
+	if (!np)
+		/* FIND node did <did> NOT FOUND */
+		lpfc_printf_vlog(vport, KERN_INFO, LOG_NODE,
+				 "0932 FIND node did x%x NOT FOUND.\n", did);
+
+	return np;
 }
 
 struct lpfc_nodelist *
-- 
2.38.0