target: Fix se_tpg_tfo->tf_subsys regression + remove tf_subsystem

There is just one configfs subsystem in the target code, so we might as
well add two helpers to reference / unreference it from the core code
instead of passing pointers to it around.

This fixes a regression introduced for v4.1-rc1 with commit 9ac8928e6,
where configfs_depend_item() callers using se_tpg_tfo->tf_subsys would
fail, because the assignment from the original target_core_subsystem[]
is no longer happening at target_register_template() time.

(Fix target_core_exit_configfs pointer dereference - Sagi)

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

1 files changed, 7 insertions, 25 deletions

diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c
index c1aa9655e96e..b7c81acf08d0 100644
--- a/drivers/target/target_core_pr.c
+++ b/drivers/target/target_core_pr.c
@@ -1367,41 +1367,26 @@ void core_scsi3_free_all_registrations(
 
 static int core_scsi3_tpg_depend_item(struct se_portal_group *tpg)
 {
-        return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
-                        &tpg->tpg_group.cg_item);
+        return target_depend_item(&tpg->tpg_group.cg_item);
 }
 
 static void core_scsi3_tpg_undepend_item(struct se_portal_group *tpg)
 {
-        configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
-                        &tpg->tpg_group.cg_item);
-
+        target_undepend_item(&tpg->tpg_group.cg_item);
         atomic_dec_mb(&tpg->tpg_pr_ref_count);
 }
 
 static int core_scsi3_nodeacl_depend_item(struct se_node_acl *nacl)
 {
-        struct se_portal_group *tpg = nacl->se_tpg;
-
         if (nacl->dynamic_node_acl)
                 return 0;
-
-        return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
-                        &nacl->acl_group.cg_item);
+        return target_depend_item(&nacl->acl_group.cg_item);
 }
 
 static void core_scsi3_nodeacl_undepend_item(struct se_node_acl *nacl)
 {
-        struct se_portal_group *tpg = nacl->se_tpg;
-
-        if (nacl->dynamic_node_acl) {
-                atomic_dec_mb(&nacl->acl_pr_ref_count);
-                return;
-        }
-
-        configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
-                        &nacl->acl_group.cg_item);
-
+        if (!nacl->dynamic_node_acl)
+                target_undepend_item(&nacl->acl_group.cg_item);
         atomic_dec_mb(&nacl->acl_pr_ref_count);
 }
 
@@ -1419,8 +1404,7 @@ static int core_scsi3_lunacl_depend_item(struct se_dev_entry *se_deve)
         nacl = lun_acl->se_lun_nacl;
         tpg = nacl->se_tpg;
 
-        return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
-                        &lun_acl->se_lun_group.cg_item);
+        return target_depend_item(&lun_acl->se_lun_group.cg_item);
 }
 
 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *se_deve)
@@ -1438,9 +1422,7 @@ static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *se_deve)
         nacl = lun_acl->se_lun_nacl;
         tpg = nacl->se_tpg;
 
-        configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
-                        &lun_acl->se_lun_group.cg_item);
-
+        target_undepend_item(&lun_acl->se_lun_group.cg_item);
         atomic_dec_mb(&se_deve->pr_ref_count);
 }