[PATCH 1/3] ibmvfc: Handle move login failure

[Brian King <brking@linux.vnet.ibm.com>]

When service is being performed on an SVC with NPIV enabled, the WWPN of
the canister / node being serviced fails over to the another canister /
node. This looks to the ibmvfc driver as a WWPN moving from one SCSI ID
to another. The driver will first attempt to do an implicit logout of
the old SCSI ID. If this works, we simply delete the rport at the old
location and add an rport at the new location and the FC transport class
handles everything. However, if there is I/O outstanding, this implicit
logout will fail, in which case we will send a "move login" request to
the VIOS. This will cancel any outstanding I/O to that port, logout the
port, and PLOGI the new port. Recently we've encountered a scenario
where the move login fails. This was resulting in an attempted plogi
to the new scsi id, without the old scsi id getting logged out, which
is a VIOS protocol violation. To solve this, we want to keep tracking
the old scsi id as the current scsi id. That way, once
terminate_rport_io cancels the outstanding i/o, it will send us back
through to do an implicit logout of the old scsi id, rather than the
new scsi id, and then we can plogi the new scsi id.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
---
 drivers/scsi/ibmvscsi/ibmvfc.c | 16 ++++++++--------
 drivers/scsi/ibmvscsi/ibmvfc.h |  2 +-
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
index 6540d48..4ac5bff 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.c
+++ b/drivers/scsi/ibmvscsi/ibmvfc.c
@@ -4299,9 +4299,10 @@ static void ibmvfc_tgt_move_login_done(struct ibmvfc_event *evt)
 	ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_NONE);
 	switch (status) {
 	case IBMVFC_MAD_SUCCESS:
-		tgt_dbg(tgt, "Move Login succeeded for old scsi_id: %llX\n", tgt->old_scsi_id);
+		tgt_dbg(tgt, "Move Login succeeded for new scsi_id: %llX\n", tgt->new_scsi_id);
 		tgt->ids.node_name = wwn_to_u64(rsp->service_parms.node_name);
 		tgt->ids.port_name = wwn_to_u64(rsp->service_parms.port_name);
+		tgt->scsi_id = tgt->new_scsi_id;
 		tgt->ids.port_id = tgt->scsi_id;
 		memcpy(&tgt->service_parms, &rsp->service_parms,
 		       sizeof(tgt->service_parms));
@@ -4319,8 +4320,8 @@ static void ibmvfc_tgt_move_login_done(struct ibmvfc_event *evt)
 		level += ibmvfc_retry_tgt_init(tgt, ibmvfc_tgt_move_login);
 
 		tgt_log(tgt, level,
-			"Move Login failed: old scsi_id: %llX, flags:%x, vios_flags:%x, rc=0x%02X\n",
-			tgt->old_scsi_id, be32_to_cpu(rsp->flags), be16_to_cpu(rsp->vios_flags),
+			"Move Login failed: new scsi_id: %llX, flags:%x, vios_flags:%x, rc=0x%02X\n",
+			tgt->new_scsi_id, be32_to_cpu(rsp->flags), be16_to_cpu(rsp->vios_flags),
 			status);
 		break;
 	}
@@ -4357,8 +4358,8 @@ static void ibmvfc_tgt_move_login(struct ibmvfc_target *tgt)
 	move->common.opcode = cpu_to_be32(IBMVFC_MOVE_LOGIN);
 	move->common.length = cpu_to_be16(sizeof(*move));
 
-	move->old_scsi_id = cpu_to_be64(tgt->old_scsi_id);
-	move->new_scsi_id = cpu_to_be64(tgt->scsi_id);
+	move->old_scsi_id = cpu_to_be64(tgt->scsi_id);
+	move->new_scsi_id = cpu_to_be64(tgt->new_scsi_id);
 	move->wwpn = cpu_to_be64(tgt->wwpn);
 	move->node_name = cpu_to_be64(tgt->ids.node_name);
 
@@ -4367,7 +4368,7 @@ static void ibmvfc_tgt_move_login(struct ibmvfc_target *tgt)
 		ibmvfc_set_tgt_action(tgt, IBMVFC_TGT_ACTION_DEL_RPORT);
 		kref_put(&tgt->kref, ibmvfc_release_tgt);
 	} else
-		tgt_dbg(tgt, "Sent Move Login for old scsi_id: %llX\n", tgt->old_scsi_id);
+		tgt_dbg(tgt, "Sent Move Login for new scsi_id: %llX\n", tgt->new_scsi_id);
 }
 
 /**
@@ -4737,8 +4738,7 @@ static int ibmvfc_alloc_target(struct ibmvfc_host *vhost,
 			 * normal ibmvfc_set_tgt_action to set this, as we
 			 * don't normally want to allow this state change.
 			 */
-			wtgt->old_scsi_id = wtgt->scsi_id;
-			wtgt->scsi_id = scsi_id;
+			wtgt->new_scsi_id = scsi_id;
 			wtgt->action = IBMVFC_TGT_ACTION_INIT;
 			ibmvfc_init_tgt(wtgt, ibmvfc_tgt_move_login);
 			goto unlock_out;
diff --git a/drivers/scsi/ibmvscsi/ibmvfc.h b/drivers/scsi/ibmvscsi/ibmvfc.h
index 19dcec3..4601bd2 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.h
+++ b/drivers/scsi/ibmvscsi/ibmvfc.h
@@ -718,7 +718,7 @@ struct ibmvfc_target {
 	struct ibmvfc_host *vhost;
 	u64 scsi_id;
 	u64 wwpn;
-	u64 old_scsi_id;
+	u64 new_scsi_id;
 	struct fc_rport *rport;
 	int target_id;
 	enum ibmvfc_target_action action;
-- 
1.8.3.1