iscsi-target: remove usage of ->shutdown_session

->shutdown session only decideѕ if the target core calls ->close_session
directly, or if the fabrics drivers calls it manually later through
target_put_session, which at this point will always close the session as
it has been removed from the lookup list and thus no new references will
be acquired from the core.

So instead remove ->shutdown and have the core call ->close_session
directly, and replace all calls to target_put_session in the iSCSI target
with direct calls to iscsit_close_session.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/iscsi/iscsi_target.c

@@ -4270,7 +4270,7 @@ int iscsit_close_connection(
 	if (!atomic_read(&sess->session_reinstatement) &&
 	     atomic_read(&sess->session_fall_back_to_erl0)) {
 		spin_unlock_bh(&sess->conn_lock);
-		target_put_session(sess->se_sess);
+		iscsit_close_session(sess);
 
 		return 0;
 	} else if (atomic_read(&sess->session_logout)) {
@@ -4299,6 +4299,10 @@ int iscsit_close_connection(
 	}
 }
 
+/*
+ * If the iSCSI Session for the iSCSI Initiator Node exists,
+ * forcefully shutdown the iSCSI NEXUS.
+ */
 int iscsit_close_session(struct iscsi_session *sess)
 {
 	struct iscsi_portal_group *tpg = sess->tpg;
@@ -4398,7 +4402,7 @@ static void iscsit_logout_post_handler_closesession(
 	iscsit_dec_conn_usage_count(conn);
 	iscsit_stop_session(sess, sleep, sleep);
 	iscsit_dec_session_usage_count(sess);
-	target_put_session(sess->se_sess);
+	iscsit_close_session(sess);
 }
 
 static void iscsit_logout_post_handler_samecid(
@@ -4570,7 +4574,7 @@ int iscsit_free_session(struct iscsi_session *sess)
 	} else
 		spin_unlock_bh(&sess->conn_lock);
 
-	target_put_session(sess->se_sess);
+	iscsit_close_session(sess);
 	return 0;
 }
 

drivers/target/iscsi/iscsi_target_configfs.c

@@ -1630,7 +1630,7 @@ static int lio_tpg_check_prot_fabric_only(
  * This function calls iscsit_inc_session_usage_count() on the
  * struct iscsi_session in question.
  */
-static int lio_tpg_shutdown_session(struct se_session *se_sess)
+static void lio_tpg_close_session(struct se_session *se_sess)
 {
 	struct iscsi_session *sess = se_sess->fabric_sess_ptr;
 	struct se_portal_group *se_tpg = &sess->tpg->tpg_se_tpg;
@@ -1642,7 +1642,7 @@ static int lio_tpg_shutdown_session(struct se_session *se_sess)
 	    (sess->time2retain_timer_flags & ISCSI_TF_EXPIRED)) {
 		spin_unlock(&sess->conn_lock);
 		spin_unlock_bh(&se_tpg->session_lock);
-		return 0;
+		return;
 	}
 	atomic_set(&sess->session_reinstatement, 1);
 	spin_unlock(&sess->conn_lock);
@@ -1651,20 +1651,6 @@ static int lio_tpg_shutdown_session(struct se_session *se_sess)
 	spin_unlock_bh(&se_tpg->session_lock);
 
 	iscsit_stop_session(sess, 1, 1);
-	return 1;
-}
-
-/*
- * Calls iscsit_dec_session_usage_count() as inverse of
- * lio_tpg_shutdown_session()
- */
-static void lio_tpg_close_session(struct se_session *se_sess)
-{
-	struct iscsi_session *sess = se_sess->fabric_sess_ptr;
-	/*
-	 * If the iSCSI Session for the iSCSI Initiator Node exists,
-	 * forcefully shutdown the iSCSI NEXUS.
-	 */
 	iscsit_close_session(sess);
 }
 
@@ -1716,7 +1702,6 @@ const struct target_core_fabric_ops iscsi_ops = {
 	.tpg_get_inst_index		= lio_tpg_get_inst_index,
 	.check_stop_free		= lio_check_stop_free,
 	.release_cmd			= lio_release_cmd,
-	.shutdown_session		= lio_tpg_shutdown_session,
 	.close_session			= lio_tpg_close_session,
 	.sess_get_index			= lio_sess_get_index,
 	.sess_get_initiator_sid		= lio_sess_get_initiator_sid,

drivers/target/iscsi/iscsi_target_erl0.c

@@ -786,7 +786,7 @@ static void iscsit_handle_time2retain_timeout(unsigned long data)
 	}
 
 	spin_unlock_bh(&se_tpg->session_lock);
-	target_put_session(sess->se_sess);
+	iscsit_close_session(sess);
 }
 
 void iscsit_start_time2retain_handler(struct iscsi_session *sess)

drivers/target/iscsi/iscsi_target_login.c

@@ -228,7 +228,7 @@ int iscsi_check_for_session_reinstatement(struct iscsi_conn *conn)
 	if (sess->session_state == TARG_SESS_STATE_FAILED) {
 		spin_unlock_bh(&sess->conn_lock);
 		iscsit_dec_session_usage_count(sess);
-		target_put_session(sess->se_sess);
+		iscsit_close_session(sess);
 		return 0;
 	}
 	spin_unlock_bh(&sess->conn_lock);
@@ -236,7 +236,7 @@ int iscsi_check_for_session_reinstatement(struct iscsi_conn *conn)
 	iscsit_stop_session(sess, 1, 1);
 	iscsit_dec_session_usage_count(sess);
 
-	target_put_session(sess->se_sess);
+	iscsit_close_session(sess);
 	return 0;
 }