scsi: qla2xxx: move IO flush to the front of NVME rport unregistration

On session deletion, current qla code would unregister an NVMe session
before flushing IOs. This patch would move the unregistration of NVMe
session after IO flush. This way FC-NVMe layer would not have to wait for
stuck IOs. In addition, qla2xxx would stop accepting new IOs during session
deletion.
Signed-off-by: Quinn Tran <qutran@marvell.com>
Signed-off-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/qla2xxx/qla_def.h

@@ -2339,7 +2339,6 @@ typedef struct fc_port {
 	unsigned int id_changed:1;
 	unsigned int scan_needed:1;
 
-	struct work_struct nvme_del_work;
 	struct completion nvme_del_done;
 	uint32_t nvme_prli_service_param;
 #define NVME_PRLI_SP_CONF       BIT_7

drivers/scsi/qla2xxx/qla_gbl.h

@@ -908,4 +908,6 @@ void qlt_clr_qp_table(struct scsi_qla_host *vha);
 void qlt_set_mode(struct scsi_qla_host *);
 int qla2x00_set_data_rate(scsi_qla_host_t *vha, uint16_t mode);
 
+/* nvme.c */
+void qla_nvme_unregister_remote_port(struct fc_port *fcport);
 #endif /* _QLA_GBL_H */

drivers/scsi/qla2xxx/qla_nvme.c

@@ -12,8 +12,6 @@
 
 static struct nvme_fc_port_template qla_nvme_fc_transport;
 
-static void qla_nvme_unregister_remote_port(struct work_struct *);
-
 int qla_nvme_register_remote(struct scsi_qla_host *vha, struct fc_port *fcport)
 {
 	struct qla_nvme_rport *rport;
@@ -38,7 +36,6 @@ int qla_nvme_register_remote(struct scsi_qla_host *vha, struct fc_port *fcport)
 		(fcport->nvme_flag & NVME_FLAG_REGISTERED))
 		return 0;
 
-	INIT_WORK(&fcport->nvme_del_work, qla_nvme_unregister_remote_port);
 	fcport->nvme_flag &= ~NVME_FLAG_RESETTING;
 
 	memset(&req, 0, sizeof(struct nvme_fc_port_info));
@@ -619,16 +616,11 @@ static void qla_nvme_remoteport_delete(struct nvme_fc_remote_port *rport)
 	fcport = qla_rport->fcport;
 	fcport->nvme_remote_port = NULL;
 	fcport->nvme_flag &= ~NVME_FLAG_REGISTERED;
-
-	complete(&fcport->nvme_del_done);
-
-	INIT_WORK(&fcport->free_work, qlt_free_session_done);
-	schedule_work(&fcport->free_work);
-
 	fcport->nvme_flag &= ~NVME_FLAG_DELETING;
 	ql_log(ql_log_info, fcport->vha, 0x2110,
 	    "remoteport_delete of %p %8phN completed.\n",
 	    fcport, fcport->port_name);
+	complete(&fcport->nvme_del_done);
 }
 
 static struct nvme_fc_port_template qla_nvme_fc_transport = {
@@ -650,10 +642,8 @@ static struct nvme_fc_port_template qla_nvme_fc_transport = {
 	.fcprqst_priv_sz = sizeof(struct nvme_private),
 };
 
-static void qla_nvme_unregister_remote_port(struct work_struct *work)
+void qla_nvme_unregister_remote_port(struct fc_port *fcport)
 {
-	struct fc_port *fcport = container_of(work, struct fc_port,
-	    nvme_del_work);
 	int ret;
 
 	if (!IS_ENABLED(CONFIG_NVME_FC))

drivers/scsi/qla2xxx/qla_target.c

@@ -1013,6 +1013,12 @@ void qlt_free_session_done(struct work_struct *work)
 				else
 					logout_started = true;
 			}
+		} /* if sess->logout_on_delete */
+
+		if (sess->nvme_flag & NVME_FLAG_REGISTERED &&
+		    !(sess->nvme_flag & NVME_FLAG_DELETING)) {
+			sess->nvme_flag |= NVME_FLAG_DELETING;
+			qla_nvme_unregister_remote_port(sess);
 		}
 	}
 
@@ -1164,14 +1170,8 @@ void qlt_unreg_sess(struct fc_port *sess)
 	sess->last_rscn_gen = sess->rscn_gen;
 	sess->last_login_gen = sess->login_gen;
 
-	if (sess->nvme_flag & NVME_FLAG_REGISTERED &&
-	    !(sess->nvme_flag & NVME_FLAG_DELETING)) {
-		sess->nvme_flag |= NVME_FLAG_DELETING;
-		schedule_work(&sess->nvme_del_work);
-	} else {
-		INIT_WORK(&sess->free_work, qlt_free_session_done);
-		schedule_work(&sess->free_work);
-	}
+	INIT_WORK(&sess->free_work, qlt_free_session_done);
+	schedule_work(&sess->free_work);
 }
 EXPORT_SYMBOL(qlt_unreg_sess);