[PATCH 05/14] lpfc: Fix rediscovery of tape device after issue lip

From: James Smart <jsmart2021@gmail.com>
To: linux-scsi@vger.kernel.org
Cc: James Smart <jsmart2021@gmail.com>, Justin Tee <justin.tee@broadcom.com>
Subject: [PATCH 05/14] lpfc: Fix rediscovery of tape device after issue lip
Date: Fri, 10 Sep 2021 16:31:50 -0700	[thread overview]
Message-ID: <20210910233159.115896-6-jsmart2021@gmail.com> (raw)
In-Reply-To: <20210910233159.115896-1-jsmart2021@gmail.com>

On link up and node discovery, a remote port is registered with the
scsi transport and the driver sets fc4_xpt_flags to track transport
registration.

A link down event causes the driver to deregister with the scsi
transport, starting the devloss timer, and calls a local unreg
routine to clear the login state. Part of the login state is the
fc4_xpt_flags.  However, with TAPE devices that support sequence level
error recovery, which wants to preserve the login, the local unreg
routine is skipped, thus the flags aren't cleared.

A subsequent link up, ADISC is performed and the lpfc_nlp_reg_node()
routine is called. As the fc4_xpt_flags is not clear, it's believed
the node is already registered with the transport. Unfortunately, the
registration was already terminated. Eventually the devloss tmo timer
expires and tears down the device.

Fix by ensuring the tape device, known by the ADISC flag, is always
unregistered if the link drops.

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_hbadisc.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_hbadisc.c b/drivers/scsi/lpfc/lpfc_hbadisc.c
index 4ff93aef3295..12abfc027a67 100644
--- a/drivers/scsi/lpfc/lpfc_hbadisc.c
+++ b/drivers/scsi/lpfc/lpfc_hbadisc.c
@@ -4693,8 +4693,11 @@ lpfc_nlp_state_cleanup(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
 	/* Reg/Unreg for FCP and NVME Transport interface */
 	if ((old_state == NLP_STE_MAPPED_NODE ||
 	     old_state == NLP_STE_UNMAPPED_NODE)) {
-		/* For nodes marked for ADISC, Handle unreg in ADISC cmpl */
-		if (!(ndlp->nlp_flag & NLP_NPR_ADISC))
+		/* For nodes marked for ADISC, Handle unreg in ADISC cmpl
+		 * if linkup. In linkdown do unreg_node
+		 */
+		if (!(ndlp->nlp_flag & NLP_NPR_ADISC) ||
+		    !lpfc_is_link_up(vport->phba))
 			lpfc_nlp_unreg_node(vport, ndlp);
 	}
 
-- 
2.26.2

