[PATCH v5 05/10] lpfc: Add handling for when PLOGI or PRLI is dropped during link failure

[Nigel Kirkland <nkirkland2304@gmail.com>]

PLOGI and PRLI typically complete via the lpfc_cmpl_els_plogi and
lpfc_cmpl_els_prli handler respectively, but when the link drops they
complete via the lpfc_cmpl_els_link_down handler.  When this occurs, normal
cleanup completion actions are missed and we may fail to recover the login
session due to ndlp logistical mixups.  Fix by clearing the NLP_PLOGI_SND
or NLP_PRLI_SND flag and decrement the outstanding prli_sent counters in
the lpfc_cmpl_els_link_down handler.

Signed-off-by: Nigel Kirkland <nkirkland2304@gmail.com>
---
 drivers/scsi/lpfc/lpfc_els.c | 35 ++++++++++++++++++++++++++++++-----
 1 file changed, 30 insertions(+), 5 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_els.c b/drivers/scsi/lpfc/lpfc_els.c
index 45aad4cd2dc8..cd431c7bd9f0 100644
--- a/drivers/scsi/lpfc/lpfc_els.c
+++ b/drivers/scsi/lpfc/lpfc_els.c
@@ -1230,6 +1230,8 @@ lpfc_cmpl_els_link_down(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb,
 	uint32_t *pcmd;
 	uint32_t cmd;
 	u32 ulp_status, ulp_word4;
+	struct lpfc_vport *vport = cmdiocb->vport;
+	struct lpfc_nodelist *ndlp = cmdiocb->ndlp;
 
 	pcmd = (uint32_t *)cmdiocb->cmd_dmabuf->virt;
 	cmd = *pcmd;
@@ -1237,17 +1239,40 @@ lpfc_cmpl_els_link_down(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb,
 	ulp_status = get_job_ulpstatus(phba, rspiocb);
 	ulp_word4 = get_job_word4(phba, rspiocb);
 
-	lpfc_printf_log(phba, KERN_INFO, LOG_ELS,
-			"6445 ELS completes after LINK_DOWN: "
-			" Status %x/%x cmd x%x flg x%x iotag x%x\n",
-			ulp_status, ulp_word4, cmd,
-			cmdiocb->cmd_flag, cmdiocb->iotag);
+	lpfc_printf_vlog(vport, KERN_INFO, LOG_ELS,
+			 "6445 ELS completes after LINK_DOWN: "
+			 "Status %x/%x cmd x%x data: x%x x%x x%x x%px x%px\n",
+			 ulp_status, ulp_word4, cmd,
+			 cmdiocb->cmd_flag, cmdiocb->iotag,
+			 ndlp->nlp_state, vport, ndlp);
+
+	if (cmd == ELS_CMD_PLOGI) {
+		/* A PLOGI ELS IO needs to clear the PLOGI_SND flag to
+		 * acknowledge the ELS completion and allow recovery. Otherwise
+		 * a subsequent PLOGI gets rejected as a duplicate.
+		 */
+		clear_bit(NLP_PLOGI_SND, &ndlp->nlp_flag);
+	} else if (cmd == ELS_CMD_PRLI || cmd == ELS_CMD_NVMEPRLI) {
+		/* A PRLI ELS IO needs to decrement the fc4_prli_sent count
+		 * added by the lpfc_issue_els_prli function.  A nonzero count
+		 * stops transport registrations.
+		 */
+		clear_bit(NLP_PRLI_SND, &ndlp->nlp_flag);
+		spin_lock_irq(&ndlp->lock);
+		vport->fc_prli_sent--;
+		ndlp->fc4_prli_sent--;
+		spin_unlock_irq(&ndlp->lock);
+	}
 
 	if (cmdiocb->cmd_flag & LPFC_IO_FABRIC) {
 		cmdiocb->cmd_flag &= ~LPFC_IO_FABRIC;
 		atomic_dec(&phba->fabric_iocb_count);
 	}
+
 	lpfc_els_free_iocb(phba, cmdiocb);
+
+	/* lpfc took a reference in the issue.  Release it now. */
+	lpfc_nlp_put(ndlp);
 }
 
 /**
-- 
2.38.0