tcm_qla2xxx: Convert to TFO->put_session() usage

This patch converts tcm_qla2xxx code to use an internal kref_put() for
se_session->sess_kref in order to ensure that qla_hw_data->hardware_lock
can be held while calling qlt_unreg_sess() for the final put.
Signed-off-by: Joern Engel <joern@logfs.org>
Cc: Roland Dreier <roland@purestorage.com>
Cc: Arun Easi <arun.easi@qlogic.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/scsi/qla2xxx/tcm_qla2xxx.c

@@ -844,9 +844,28 @@ static void tcm_qla2xxx_clear_nacl_from_fcport_map(struct qla_tgt_sess *sess)
 	    se_nacl, nacl->nport_wwnn, nacl->nport_id);
 }
 
+static void tcm_qla2xxx_release_session(struct kref *kref)
+{
+	struct se_session *se_sess = container_of(kref,
+			struct se_session, sess_kref);
+
+	qlt_unreg_sess(se_sess->fabric_sess_ptr);
+}
+
+static void tcm_qla2xxx_put_session(struct se_session *se_sess)
+{
+	struct qla_tgt_sess *sess = se_sess->fabric_sess_ptr;
+	struct qla_hw_data *ha = sess->vha->hw;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ha->hardware_lock, flags);
+	kref_put(&se_sess->sess_kref, tcm_qla2xxx_release_session);
+	spin_unlock_irqrestore(&ha->hardware_lock, flags);
+}
+
 static void tcm_qla2xxx_put_sess(struct qla_tgt_sess *sess)
 {
-	target_put_session(sess->se_sess);
+	tcm_qla2xxx_put_session(sess->se_sess);
 }
 
 static void tcm_qla2xxx_shutdown_sess(struct qla_tgt_sess *sess)
@@ -1731,6 +1750,7 @@ static struct target_core_fabric_ops tcm_qla2xxx_ops = {
 	.new_cmd_map			= NULL,
 	.check_stop_free		= tcm_qla2xxx_check_stop_free,
 	.release_cmd			= tcm_qla2xxx_release_cmd,
+	.put_session			= tcm_qla2xxx_put_session,
 	.shutdown_session		= tcm_qla2xxx_shutdown_session,
 	.close_session			= tcm_qla2xxx_close_session,
 	.sess_get_index			= tcm_qla2xxx_sess_get_index,
@@ -1779,6 +1799,7 @@ static struct target_core_fabric_ops tcm_qla2xxx_npiv_ops = {
 	.tpg_release_fabric_acl		= tcm_qla2xxx_release_fabric_acl,
 	.tpg_get_inst_index		= tcm_qla2xxx_tpg_get_inst_index,
 	.release_cmd			= tcm_qla2xxx_release_cmd,
+	.put_session			= tcm_qla2xxx_put_session,
 	.shutdown_session		= tcm_qla2xxx_shutdown_session,
 	.close_session			= tcm_qla2xxx_close_session,
 	.sess_get_index			= tcm_qla2xxx_sess_get_index,