[PATCH 3/6] scsi: lpfc: Fix lost NVMe paths during LIF bounce stress test

[Jeff Lane]

From: James Smart <jsmart2021 at gmail.com>

BugLink: https://bugs.launchpad.net/bugs/1988711

During a target link bounce test, the driver sees a mismatch between the
NPortId and the WWPN on the node structures (ndlps) involved.  When this
occurs, the driver "swaps" the ndlp and new_ndlp node parameters to restore
WWPN/DID uniqueness in the fc_nodes list per vport.  However, the driver
neglected to swap the nlp_fc4_type in the ndlp passed to
lpfc_plogi_confirm_nport causing a failure to recover the NVMe PLOGI/PRLI
and ultimately the NVMe paths.

Correct confirm_nport to preserve the fc4 types from the new-ndlp when the
data is moved over ot the ndlp structure.

Link: https://lore.kernel.org/r/20220701211425.2708-8-jsmart2021@gmail.com
Co-developed-by: Justin Tee <justin.tee at broadcom.com>
Signed-off-by: Justin Tee <justin.tee at broadcom.com>
Signed-off-by: James Smart <jsmart2021 at gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen at oracle.com>
(cherry picked from commit ea92e173dc55460f1b9e71df5ceac951c506d214)
Signed-off-by: Jeff Lane <jeffrey.lane at canonical.com>
---
 drivers/scsi/lpfc/lpfc_els.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_els.c b/drivers/scsi/lpfc/lpfc_els.c
index c904e9486b92..9371829e11b2 100644
--- a/drivers/scsi/lpfc/lpfc_els.c
+++ b/drivers/scsi/lpfc/lpfc_els.c
@@ -1790,18 +1790,20 @@ lpfc_plogi_confirm_nport(struct lpfc_hba *phba, uint32_t *prsp,
 
 	/* Move this back to NPR state */
 	if (memcmp(&ndlp->nlp_portname, name, sizeof(struct lpfc_name)) == 0) {
-		/* The new_ndlp is replacing ndlp totally, so we need
-		 * to put ndlp on UNUSED list and try to free it.
+		/* The ndlp doesn't have a portname yet, but does have an
+		 * NPort ID.  The new_ndlp portname matches the Rport's
+		 * portname.  Reinstantiate the new_ndlp and reset the ndlp.
 		 */
 		lpfc_printf_vlog(vport, KERN_INFO, LOG_ELS,
 			 "3179 PLOGI confirm NEW: %x %x\n",
 			 new_ndlp->nlp_DID, keepDID);
 
 		/* Two ndlps cannot have the same did on the nodelist.
-		 * Note: for this case, ndlp has a NULL WWPN so setting
-		 * the nlp_fc4_type isn't required.
+		 * The KeepDID and keep_nlp_fc4_type need to be swapped
+		 * because ndlp is inflight with no WWPN.
 		 */
 		ndlp->nlp_DID = keepDID;
+		ndlp->nlp_fc4_type = keep_nlp_fc4_type;
 		lpfc_nlp_set_state(vport, ndlp, keep_nlp_state);
 		if (phba->sli_rev == LPFC_SLI_REV4 &&
 		    active_rrqs_xri_bitmap)
@@ -1816,9 +1818,8 @@ lpfc_plogi_confirm_nport(struct lpfc_hba *phba, uint32_t *prsp,
 
 		lpfc_unreg_rpi(vport, ndlp);
 
-		/* Two ndlps cannot have the same did and the fc4
-		 * type must be transferred because the ndlp is in
-		 * flight.
+		/* The ndlp and new_ndlp both have WWPNs but are swapping
+		 * NPort Ids and attributes.
 		 */
 		ndlp->nlp_DID = keepDID;
 		ndlp->nlp_fc4_type = keep_nlp_fc4_type;
-- 
2.34.1