scsi: target: Remove tpg_list and se_portal_group.se_tpg_node

Maintaining tpg_list without ever iterating over it is not useful. Hence
remove tpg_list. This patch does not change the behavior of the SCSI target
code.

Cc: Mike Christie <mchristie@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Link: https://lore.kernel.org/r/20190930232224.58980-1-bvanassche@acm.org
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/target/target_core_tpg.c

@@ -32,9 +32,6 @@
 
 extern struct se_device *g_lun0_dev;
 
-static DEFINE_SPINLOCK(tpg_lock);
-static LIST_HEAD(tpg_list);
-
 /*	__core_tpg_get_initiator_node_acl():
  *
  *	mutex_lock(&tpg->acl_node_mutex); must be held when calling
@@ -475,7 +472,6 @@ int core_tpg_register(
 	se_tpg->se_tpg_wwn = se_wwn;
 	atomic_set(&se_tpg->tpg_pr_ref_count, 0);
 	INIT_LIST_HEAD(&se_tpg->acl_node_list);
-	INIT_LIST_HEAD(&se_tpg->se_tpg_node);
 	INIT_LIST_HEAD(&se_tpg->tpg_sess_list);
 	spin_lock_init(&se_tpg->session_lock);
 	mutex_init(&se_tpg->tpg_lun_mutex);
@@ -494,10 +490,6 @@ int core_tpg_register(
 		}
 	}
 
-	spin_lock_bh(&tpg_lock);
-	list_add_tail(&se_tpg->se_tpg_node, &tpg_list);
-	spin_unlock_bh(&tpg_lock);
-
 	pr_debug("TARGET_CORE[%s]: Allocated portal_group for endpoint: %s, "
 		 "Proto: %d, Portal Tag: %u\n", se_tpg->se_tpg_tfo->fabric_name,
 		se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg) ?
@@ -519,10 +511,6 @@ int core_tpg_deregister(struct se_portal_group *se_tpg)
 		tfo->tpg_get_wwn(se_tpg) ? tfo->tpg_get_wwn(se_tpg) : NULL,
 		se_tpg->proto_id, tfo->tpg_get_tag(se_tpg));
 
-	spin_lock_bh(&tpg_lock);
-	list_del(&se_tpg->se_tpg_node);
-	spin_unlock_bh(&tpg_lock);
-
 	while (atomic_read(&se_tpg->tpg_pr_ref_count) != 0)
 		cpu_relax();
 

drivers/target/target_core_xcopy.c

@@ -467,7 +467,6 @@ int target_xcopy_setup_pt(void)
 	}
 
 	memset(&xcopy_pt_tpg, 0, sizeof(struct se_portal_group));
-	INIT_LIST_HEAD(&xcopy_pt_tpg.se_tpg_node);
 	INIT_LIST_HEAD(&xcopy_pt_tpg.acl_node_list);
 	INIT_LIST_HEAD(&xcopy_pt_tpg.tpg_sess_list);
 

include/target/target_core_base.h

@@ -876,7 +876,6 @@ struct se_portal_group {
 	/* Spinlock for adding/removing sessions */
 	spinlock_t		session_lock;
 	struct mutex		tpg_lun_mutex;
-	struct list_head	se_tpg_node;
 	/* linked list for initiator ACL list */
 	struct list_head	acl_node_list;
 	struct hlist_head	tpg_lun_hlist;