scsi: lpfc: Ignore ndlp rport mismatch in dev_loss_tmo callbk

With repeated port swaps between separate fabrics, there can be multiple
registrations for fabric well known address 0xfffffe.  This can cause ndlp
reference confusion due to the usage of a single ndlp ptr that stores the
rport object in fc_rport struct private storage during transport
registration.  Subsequent registrations update the ndlp->rport field with
the newer rport, so when transport layer triggers dev_loss_tmo for the
earlier registered rport the ndlp->rport private storage is referencing the
newer rport instead of the older rport in dev_loss_tmo callbk.

Because the older ndlp->rport object is already cleaned up elsewhere in
driver code during the time of fabric swap, check that the rport provided
in dev_loss_tmo callbk actually matches the rport stored in the LLDD's
ndlp->rport field.  Otherwise, skip dev_loss_tmo work on a stale rport.

Signed-off-by: Justin Tee <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Martin K. Petersen <[email protected]>
(cherry picked from commit 23ed62897746f49f195d819ce6edeb1db27d1b72)

Orabug: 37603756

Signed-off-by: Harshit Mogalapalli <[email protected]>
Reviewed-by: Jack Vogel <[email protected]>

Author: Justin Tee

drivers/scsi/lpfc/lpfc_hbadisc.c

@@ -228,10 +228,16 @@ lpfc_dev_loss_tmo_callbk(struct fc_rport *rport)
 	if (ndlp->nlp_state == NLP_STE_MAPPED_NODE)
 		return;
 
-	/* check for recovered fabric node */
-	if (ndlp->nlp_state == NLP_STE_UNMAPPED_NODE &&
-	    ndlp->nlp_DID == Fabric_DID)
+	/* Ignore callback for a mismatched (stale) rport */
+	if (ndlp->rport != rport) {
+		lpfc_vlog_msg(vport, KERN_WARNING, LOG_NODE,
+			      "6788 fc rport mismatch: d_id x%06x ndlp x%px "
+			      "fc rport x%px node rport x%px state x%x "
+			      "refcnt %u\n",
+			      ndlp->nlp_DID, ndlp, rport, ndlp->rport,
+			      ndlp->nlp_state, kref_read(&ndlp->kref));
 		return;
+	}
 
 	if (rport->port_name != wwn_to_u64(ndlp->nlp_portname.u.wwn))
 		lpfc_printf_vlog(vport, KERN_ERR, LOG_TRACE_EVENT,