target: remove the transport_lun_active field in struct se_cmd

There is no reason to have a flag telling if a command is on the per-lun list,
we can simply do a list_empty check before removing it as long as we're careful
to always use list_del_init.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/target_core_device.c

@@ -159,13 +159,8 @@ int transport_lookup_cmd_lun(struct se_cmd *se_cmd, u32 unpacked_lun)
 		dev->read_bytes += se_cmd->data_length;
 	spin_unlock_irqrestore(&dev->stats_lock, flags);
 
-	/*
-	 * Add the iscsi_cmd_t to the struct se_lun's cmd list.  This list is used
-	 * for tracking state of struct se_cmds during LUN shutdown events.
-	 */
 	spin_lock_irqsave(&se_lun->lun_cmd_lock, flags);
 	list_add_tail(&se_cmd->se_lun_node, &se_lun->lun_cmd_list);
-	atomic_set(&se_cmd->transport_lun_active, 1);
 	spin_unlock_irqrestore(&se_lun->lun_cmd_lock, flags);
 
 	return 0;

drivers/target/target_core_transport.c

@@ -546,14 +546,8 @@ static void transport_lun_remove_cmd(struct se_cmd *cmd)
 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 
 	spin_lock_irqsave(&lun->lun_cmd_lock, flags);
-	if (atomic_read(&cmd->transport_lun_active)) {
-		list_del(&cmd->se_lun_node);
-		atomic_set(&cmd->transport_lun_active, 0);
-#if 0
-		pr_debug("Removed ITT: 0x%08x from LUN LIST[%d]\n"
-			cmd->se_tfo->get_task_tag(cmd), lun->unpacked_lun);
-#endif
-	}
+	if (!list_empty(&cmd->se_lun_node))
+		list_del_init(&cmd->se_lun_node);
 	spin_unlock_irqrestore(&lun->lun_cmd_lock, flags);
 }
 
@@ -4163,9 +4157,8 @@ static void __transport_clear_lun_from_sessions(struct se_lun *lun)
 	while (!list_empty(&lun->lun_cmd_list)) {
 		cmd = list_first_entry(&lun->lun_cmd_list,
 		       struct se_cmd, se_lun_node);
-		list_del(&cmd->se_lun_node);
+		list_del_init(&cmd->se_lun_node);
 
-		atomic_set(&cmd->transport_lun_active, 0);
 		/*
 		 * This will notify iscsi_target_transport.c:
 		 * transport_cmd_check_stop() that a LUN shutdown is in

include/target/target_core_base.h

@@ -572,7 +572,6 @@ struct se_cmd {
 #define CMD_T_LUN_STOP		(1 << 7)
 #define CMD_T_LUN_FE_STOP	(1 << 8)
 #define CMD_T_DEV_ACTIVE	(1 << 9)
-	atomic_t		transport_lun_active;
 	spinlock_t		t_state_lock;
 	struct completion	t_transport_stop_comp;
 	struct completion	transport_lun_fe_stop_comp;