scsi: lpfc: Don't release final kref on Fport node while ABTS outstanding

In a rarely executed path, FLOGI failure, there is a refcounting error.  If
FLOGI completed with an error, typically a timeout, the initial completion
handler would remove the job reference. However, the job completion isn't
the actual end of the job/exchange as the timeout usually initiates an
ABTS, and upon that ABTS completion, a final completion is sent. The driver
removes the reference again in the final completion. Thus the imbalance.

In the buggy cases, if there was a link bounce while the delayed response
is outstanding, the fport node may be referenced again but there was no
additional reference as it is already present. The delayed completion then
occurs and removes the last reference freeing the node and causing issues
in the link up processed that is using the node.

Fix this scenario by removing the snippet that removed the reference in the
initial FLOGI completion. The bad snippet was poorly trying to identify the
FLOGI as OK to do so by realizing the node was not registered with either
SCSI or NVMe transport.

Link: https://lore.kernel.org/r/20210910233159.115896-3-jsmart2021@gmail.com
Fixes: 618e2ee146d4 ("scsi: lpfc: Fix FLOGI failure due to accessing a freed node")
Cc: <stable@vger.kernel.org> # v5.13+
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>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

3 files changed, 14 insertions, 12 deletions

diff --git a/drivers/scsi/lpfc/lpfc_els.c b/drivers/scsi/lpfc/lpfc_els.c
index 1254a575fd47..df5fc223ddb2 100644
--- a/drivers/scsi/lpfc/lpfc_els.c
+++ b/drivers/scsi/lpfc/lpfc_els.c
@@ -1059,9 +1059,10 @@ stop_rr_fcf_flogi:
 
 		lpfc_printf_vlog(vport, KERN_WARNING, LOG_TRACE_EVENT,
 				 "0150 FLOGI failure Status:x%x/x%x "
-				 "xri x%x TMO:x%x\n",
+				 "xri x%x TMO:x%x refcnt %d\n",
 				 irsp->ulpStatus, irsp->un.ulpWord[4],
-				 cmdiocb->sli4_xritag, irsp->ulpTimeout);
+				 cmdiocb->sli4_xritag, irsp->ulpTimeout,
+				 kref_read(&ndlp->kref));
 
 		/* If this is not a loop open failure, bail out */
 		if (!(irsp->ulpStatus == IOSTAT_LOCAL_REJECT &&
@@ -1122,12 +1123,12 @@ stop_rr_fcf_flogi:
 	/* FLOGI completes successfully */
 	lpfc_printf_vlog(vport, KERN_INFO, LOG_ELS,
 			 "0101 FLOGI completes successfully, I/O tag:x%x, "
-			 "xri x%x Data: x%x x%x x%x x%x x%x x%x x%x\n",
+			 "xri x%x Data: x%x x%x x%x x%x x%x x%x x%x %d\n",
 			 cmdiocb->iotag, cmdiocb->sli4_xritag,
 			 irsp->un.ulpWord[4], sp->cmn.e_d_tov,
 			 sp->cmn.w2.r_a_tov, sp->cmn.edtovResolution,
 			 vport->port_state, vport->fc_flag,
-			 sp->cmn.priority_tagging);
+			 sp->cmn.priority_tagging, kref_read(&ndlp->kref));
 
 	if (sp->cmn.priority_tagging)
 		vport->vmid_flag |= LPFC_VMID_ISSUE_QFPA;
@@ -1205,8 +1206,6 @@ flogifail:
 	phba->fcf.fcf_flag &= ~FCF_DISCOVERY;
 	spin_unlock_irq(&phba->hbalock);
 
-	if (!(ndlp->fc4_xpt_flags & (SCSI_XPT_REGD | NVME_XPT_REGD)))
-		lpfc_nlp_put(ndlp);
 	if (!lpfc_error_lost_link(irsp)) {
 		/* FLOGI failed, so just use loop map to make discovery list */
 		lpfc_disc_list_loopmap(vport);
diff --git a/drivers/scsi/lpfc/lpfc_hbadisc.c b/drivers/scsi/lpfc/lpfc_hbadisc.c
index 7195ca0275f9..6f2e07c30f98 100644
--- a/drivers/scsi/lpfc/lpfc_hbadisc.c
+++ b/drivers/scsi/lpfc/lpfc_hbadisc.c
@@ -4449,8 +4449,9 @@ lpfc_register_remote_port(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp)
 		fc_remote_port_rolechg(rport, rport_ids.roles);
 
 	lpfc_printf_vlog(ndlp->vport, KERN_INFO, LOG_NODE,
-			 "3183 %s rport x%px DID x%x, role x%x\n",
-			 __func__, rport, rport->port_id, rport->roles);
+			 "3183 %s rport x%px DID x%x, role x%x refcnt %d\n",
+			 __func__, rport, rport->port_id, rport->roles,
+			 kref_read(&ndlp->kref));
 
 	if ((rport->scsi_target_id != -1) &&
 	    (rport->scsi_target_id < LPFC_MAX_TARGET)) {
@@ -4475,8 +4476,9 @@ lpfc_unregister_remote_port(struct lpfc_nodelist *ndlp)
 
 	lpfc_printf_vlog(vport, KERN_INFO, LOG_NODE,
 			 "3184 rport unregister x%06x, rport x%px "
-			 "xptflg x%x\n",
-			 ndlp->nlp_DID, rport, ndlp->fc4_xpt_flags);
+			 "xptflg x%x refcnt %d\n",
+			 ndlp->nlp_DID, rport, ndlp->fc4_xpt_flags,
+			 kref_read(&ndlp->kref));
 
 	fc_remote_port_delete(rport);
 	lpfc_nlp_put(ndlp);
diff --git a/drivers/scsi/lpfc/lpfc_nvme.c b/drivers/scsi/lpfc/lpfc_nvme.c
index 73a3568ff17e..bd88477f9b82 100644
--- a/drivers/scsi/lpfc/lpfc_nvme.c
+++ b/drivers/scsi/lpfc/lpfc_nvme.c
@@ -209,8 +209,9 @@ lpfc_nvme_remoteport_delete(struct nvme_fc_remote_port *remoteport)
 	 * calling state machine to remove the node.
 	 */
 	lpfc_printf_vlog(vport, KERN_INFO, LOG_NVME_DISC,
-			"6146 remoteport delete of remoteport x%px\n",
-			remoteport);
+			 "6146 remoteport delete of remoteport x%px, ndlp x%px "
+			 "DID x%x xflags x%x\n",
+			 remoteport, ndlp, ndlp->nlp_DID, ndlp->fc4_xpt_flags);
 	spin_lock_irq(&ndlp->lock);
 
 	/* The register rebind might have occurred before the delete