[PATCH 18/20] lpfc: Skip issuing ADISC when node is in NPR state

[James Smart <jsmart2021@gmail.com>]

When a node moves to NPR state due to a device recovery event, the
nlp_fc4_types in the node are cleared. An ADISC received for a node in
the NPR state triggers an ADISC. Without fc4 types being known, the
calls to register with the transport are no-op'd, thus no additional
references are placed on the node by transport re-registrations. A
subsequent RSCN could trigger another unregister request, which will
decrement the reference counts, leading to the ref count hitting zero
and the node being freed while futher discovery on the node is being
attempted by the RSCN event handling.

Fix by skipping the trigger of an ADISC when in NPR state. The normal
ADISC process will kick off in the regular discovery path after receiving
a response from name server.

Co-developed-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
---
 drivers/scsi/lpfc/lpfc_nportdisc.c | 34 +++++++++++++++++-------------
 1 file changed, 19 insertions(+), 15 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_nportdisc.c b/drivers/scsi/lpfc/lpfc_nportdisc.c
index 46c1905f6f39..27263f02ab9f 100644
--- a/drivers/scsi/lpfc/lpfc_nportdisc.c
+++ b/drivers/scsi/lpfc/lpfc_nportdisc.c
@@ -736,9 +736,13 @@ lpfc_rcv_padisc(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
 		 * is already in MAPPED or UNMAPPED state.  Catch this
 		 * condition and don't set the nlp_state again because
 		 * it causes an unnecessary transport unregister/register.
+		 *
+		 * Nodes marked for ADISC will move MAPPED or UNMAPPED state
+		 * after issuing ADISC
 		 */
 		if (ndlp->nlp_type & (NLP_FCP_TARGET | NLP_NVME_TARGET)) {
-			if (ndlp->nlp_state != NLP_STE_MAPPED_NODE)
+			if ((ndlp->nlp_state != NLP_STE_MAPPED_NODE) &&
+			    !(ndlp->nlp_flag & NLP_NPR_ADISC))
 				lpfc_nlp_set_state(vport, ndlp,
 						   NLP_STE_MAPPED_NODE);
 		}
@@ -2646,14 +2650,13 @@ lpfc_rcv_prli_npr_node(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
 	lpfc_els_rsp_reject(vport, stat.un.lsRjtError, cmdiocb, ndlp, NULL);
 
 	if (!(ndlp->nlp_flag & NLP_DELAY_TMO)) {
-		if (ndlp->nlp_flag & NLP_NPR_ADISC) {
-			spin_lock_irq(&ndlp->lock);
-			ndlp->nlp_flag &= ~NLP_NPR_ADISC;
-			ndlp->nlp_prev_state = NLP_STE_NPR_NODE;
-			spin_unlock_irq(&ndlp->lock);
-			lpfc_nlp_set_state(vport, ndlp, NLP_STE_ADISC_ISSUE);
-			lpfc_issue_els_adisc(vport, ndlp, 0);
-		} else {
+		/*
+		 * ADISC nodes will be handled in regular discovery path after
+		 * receiving response from NS.
+		 *
+		 * For other nodes, Send PLOGI to trigger an implicit LOGO.
+		 */
+		if (!(ndlp->nlp_flag & NLP_NPR_ADISC)) {
 			ndlp->nlp_prev_state = NLP_STE_NPR_NODE;
 			lpfc_nlp_set_state(vport, ndlp, NLP_STE_PLOGI_ISSUE);
 			lpfc_issue_els_plogi(vport, ndlp->nlp_DID, 0);
@@ -2686,12 +2689,13 @@ lpfc_rcv_padisc_npr_node(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
 	 */
 	if (!(ndlp->nlp_flag & NLP_DELAY_TMO) &&
 	    !(ndlp->nlp_flag & NLP_NPR_2B_DISC)) {
-		if (ndlp->nlp_flag & NLP_NPR_ADISC) {
-			ndlp->nlp_flag &= ~NLP_NPR_ADISC;
-			ndlp->nlp_prev_state = NLP_STE_NPR_NODE;
-			lpfc_nlp_set_state(vport, ndlp, NLP_STE_ADISC_ISSUE);
-			lpfc_issue_els_adisc(vport, ndlp, 0);
-		} else {
+		/*
+		 * ADISC nodes will be handled in regular discovery path after
+		 * receiving response from NS.
+		 *
+		 * For other nodes, Send PLOGI to trigger an implicit LOGO.
+		 */
+		if (!(ndlp->nlp_flag & NLP_NPR_ADISC)) {
 			ndlp->nlp_prev_state = NLP_STE_NPR_NODE;
 			lpfc_nlp_set_state(vport, ndlp, NLP_STE_PLOGI_ISSUE);
 			lpfc_issue_els_plogi(vport, ndlp->nlp_DID, 0);
-- 
2.26.2