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, 2 insertions, 4 deletions

diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 5e19bb53b3a9..ea32b386797f 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -1409,8 +1409,7 @@ vhost_scsi_set_endpoint(struct vhost_scsi *vs,
                          * dependency now.
                          */
                         se_tpg = &tpg->se_tpg;
-                        ret = configfs_depend_item(se_tpg->se_tpg_tfo->tf_subsys,
-                                                   &se_tpg->tpg_group.cg_item);
+                        ret = target_depend_item(&se_tpg->tpg_group.cg_item);
                         if (ret) {
                                 pr_warn("configfs_depend_item() failed: %d\n", ret);
                                 kfree(vs_tpg);
@@ -1513,8 +1512,7 @@ vhost_scsi_clear_endpoint(struct vhost_scsi *vs,
                  * to allow vhost-scsi WWPN se_tpg->tpg_group shutdown to occur.
                  */
                 se_tpg = &tpg->se_tpg;
-                configfs_undepend_item(se_tpg->se_tpg_tfo->tf_subsys,
-                                       &se_tpg->tpg_group.cg_item);
+                target_undepend_item(&se_tpg->tpg_group.cg_item);
         }
         if (match) {
                 for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {