target: remove ->put_session method

The only instance of ->put_session is in qla2xxx, and was added by commit
aaf68b ("tcm_qla2xxx: Convert to TFO->put_session() usage") with the following
description:

    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.

But these day we're already holding the hardware lock over qlt_unreg_sess in
the ->close_session callback, so we're fine without this method.

(Re-add missing tcm_qla2xxx_release_session + drop put_session usage - nab)

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Himanshu Madhani <himanshu.madhani@qlogic.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/scsi/qla2xxx/tcm_qla2xxx.c

@@ -700,17 +700,6 @@ static void tcm_qla2xxx_release_session(struct kref *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)
 {
 	if (!sess)
@@ -1843,7 +1832,6 @@ static const struct target_core_fabric_ops tcm_qla2xxx_ops = {
 	.tpg_get_inst_index		= tcm_qla2xxx_tpg_get_inst_index,
 	.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,
@@ -1887,7 +1875,6 @@ static const struct target_core_fabric_ops tcm_qla2xxx_npiv_ops = {
 	.tpg_get_inst_index		= tcm_qla2xxx_tpg_get_inst_index,
 	.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,

drivers/target/target_core_transport.c

@@ -409,12 +409,6 @@ EXPORT_SYMBOL(target_get_session);
 
 void target_put_session(struct se_session *se_sess)
 {
-	struct se_portal_group *tpg = se_sess->se_tpg;
-
-	if (tpg->se_tpg_tfo->put_session != NULL) {
-		tpg->se_tpg_tfo->put_session(se_sess);
-		return;
-	}
 	kref_put(&se_sess->sess_kref, target_release_session);
 }
 EXPORT_SYMBOL(target_put_session);

drivers/xen/xen-scsiback.c

@@ -1817,7 +1817,6 @@ static const struct target_core_fabric_ops scsiback_ops = {
 	.tpg_get_inst_index		= scsiback_tpg_get_inst_index,
 	.check_stop_free		= scsiback_check_stop_free,
 	.release_cmd			= scsiback_release_cmd,
-	.put_session			= NULL,
 	.shutdown_session		= scsiback_shutdown_session,
 	.close_session			= scsiback_close_session,
 	.sess_get_index			= scsiback_sess_get_index,

include/target/target_core_fabric.h

@@ -37,7 +37,6 @@ struct target_core_fabric_ops {
 	 */
 	int (*check_stop_free)(struct se_cmd *);
 	void (*release_cmd)(struct se_cmd *);
-	void (*put_session)(struct se_session *);
 	/*
 	 * Called with spin_lock_bh(struct se_portal_group->session_lock held.
 	 */