scsi: lpfc: Fix discovery failures during port failovers with lots of vports

The driver is getting hit with 100s of RSCNs during remote port address
changes. Each of those RSCN's ends up generating UNREG_RPI and REG_PRI
mailbox commands.  The discovery engine within the driver doesn't wait for
the mailbox command completions. Instead it sets state flags and moves
forward. At some point, there's a massive backlog of mailbox commands which
take time for the adapter to process. Additionally, it appears there were
duplicate events from the switch so the driver generated duplicate mailbox
commands for the same remote port.  During this window, failures on PLOGI
and PRLI ELS's are see as the adapter is rejecting them as they are for
remote ports that still have pending mailbox commands.

Streamline the discovery engine so that PLOGI log checks for outstanding
UNREG_RPIs and defer the processing until the commands complete. This
better synchronizes the ELS transmission vs the RPI registrations.

Filter out multiple UNREG_RPIs being queued up for the same remote port.

Beef up log messages in this area.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 35 insertions, 9 deletions

diff --git a/drivers/scsi/lpfc/lpfc_nportdisc.c b/drivers/scsi/lpfc/lpfc_nportdisc.c
index 9cb93b50dd43..96bc3789a166 100644
--- a/drivers/scsi/lpfc/lpfc_nportdisc.c
+++ b/drivers/scsi/lpfc/lpfc_nportdisc.c
@@ -871,13 +871,26 @@ lpfc_disc_set_adisc(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp)
  * to release a rpi.
  **/
 void
-lpfc_release_rpi(struct lpfc_hba *phba,
-		struct lpfc_vport *vport,
-		uint16_t rpi)
+lpfc_release_rpi(struct lpfc_hba *phba, struct lpfc_vport *vport,
+		 struct lpfc_nodelist *ndlp, uint16_t rpi)
 {
 	LPFC_MBOXQ_t *pmb;
 	int rc;
 
+	/* If there is already an UNREG in progress for this ndlp,
+	 * no need to queue up another one.
+	 */
+	if (ndlp->nlp_flag & NLP_UNREG_INP) {
+		lpfc_printf_vlog(vport, KERN_INFO, LOG_DISCOVERY,
+				 "1435 release_rpi SKIP UNREG x%x on "
+				 "NPort x%x deferred x%x  flg x%x "
+				 "Data: %p\n",
+				 ndlp->nlp_rpi, ndlp->nlp_DID,
+				 ndlp->nlp_defer_did,
+				 ndlp->nlp_flag, ndlp);
+		return;
+	}
+
 	pmb = (LPFC_MBOXQ_t *) mempool_alloc(phba->mbox_mem_pool,
 			GFP_KERNEL);
 	if (!pmb)
@@ -886,6 +899,18 @@ lpfc_release_rpi(struct lpfc_hba *phba,
 	else {
 		lpfc_unreg_login(phba, vport->vpi, rpi, pmb);
 		pmb->mbox_cmpl = lpfc_sli_def_mbox_cmpl;
+		pmb->vport = vport;
+		pmb->ctx_ndlp = ndlp;
+
+		if (((ndlp->nlp_DID & Fabric_DID_MASK) != Fabric_DID_MASK) &&
+		    (!(vport->fc_flag & FC_OFFLINE_MODE)))
+			ndlp->nlp_flag |= NLP_UNREG_INP;
+
+		lpfc_printf_vlog(vport, KERN_INFO, LOG_DISCOVERY,
+				 "1437 release_rpi UNREG x%x "
+				 "on NPort x%x flg x%x\n",
+				 ndlp->nlp_rpi, ndlp->nlp_DID, ndlp->nlp_flag);
+
 		rc = lpfc_sli_issue_mbox(phba, pmb, MBX_NOWAIT);
 		if (rc == MBX_NOT_FINISHED)
 			mempool_free(pmb, phba->mbox_mem_pool);
@@ -906,7 +931,7 @@ lpfc_disc_illegal(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
 		(evt == NLP_EVT_CMPL_REG_LOGIN) &&
 		(!pmb->u.mb.mbxStatus)) {
 		rpi = pmb->u.mb.un.varWords[0];
-		lpfc_release_rpi(phba, vport, rpi);
+		lpfc_release_rpi(phba, vport, ndlp, rpi);
 	}
 	lpfc_printf_vlog(vport, KERN_ERR, LOG_DISCOVERY,
 			 "0271 Illegal State Transition: node x%x "
@@ -1334,7 +1359,7 @@ lpfc_cmpl_reglogin_plogi_issue(struct lpfc_vport *vport,
 	if (!(phba->pport->load_flag & FC_UNLOADING) &&
 		!mb->mbxStatus) {
 		rpi = pmb->u.mb.un.varWords[0];
-		lpfc_release_rpi(phba, vport, rpi);
+		lpfc_release_rpi(phba, vport, ndlp, rpi);
 	}
 	return ndlp->nlp_state;
 }
@@ -2875,8 +2900,8 @@ lpfc_disc_state_machine(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
 	/* DSM in event <evt> on NPort <nlp_DID> in state <cur_state> */
 	lpfc_printf_vlog(vport, KERN_INFO, LOG_DISCOVERY,
 			 "0211 DSM in event x%x on NPort x%x in "
-			 "state %d Data: x%x x%x\n",
-			 evt, ndlp->nlp_DID, cur_state,
+			 "state %d rpi x%x Data: x%x x%x\n",
+			 evt, ndlp->nlp_DID, cur_state, ndlp->nlp_rpi,
 			 ndlp->nlp_flag, ndlp->nlp_fc4_type);
 
 	lpfc_debugfs_disc_trc(vport, LPFC_DISC_TRC_DSM,
@@ -2889,8 +2914,9 @@ lpfc_disc_state_machine(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
 	/* DSM out state <rc> on NPort <nlp_DID> */
 	if (got_ndlp) {
 		lpfc_printf_vlog(vport, KERN_INFO, LOG_DISCOVERY,
-			 "0212 DSM out state %d on NPort x%x Data: x%x\n",
-			 rc, ndlp->nlp_DID, ndlp->nlp_flag);
+			 "0212 DSM out state %d on NPort x%x "
+			 "rpi x%x Data: x%x\n",
+			 rc, ndlp->nlp_DID, ndlp->nlp_rpi, ndlp->nlp_flag);
 
 		lpfc_debugfs_disc_trc(vport, LPFC_DISC_TRC_DSM,
 			"DSM out:         ste:%d did:x%x flg:x%x",