target: simplify the target template registration API

Instead of calling target_fabric_configfs_init() +
target_fabric_configfs_register() / target_fabric_configfs_deregister()
target_fabric_configfs_free() from every target driver, rewrite the API
so that we have simple register/unregister functions that operate on
a const operations vector.

This patch also fixes a memory leak in several target drivers. Several
target drivers namely called target_fabric_configfs_deregister()
without calling target_fabric_configfs_free().

A large part of this patch is based on earlier changes from
Bart Van Assche <bart.vanassche@sandisk.com>.

(v2: Add a new TF_CIT_SETUP_DRV macro so that the core configfs code
can declare attributes as either core only or for drivers)

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

1 files changed, 9 insertions, 48 deletions

diff --git a/drivers/usb/gadget/legacy/tcm_usb_gadget.c b/drivers/usb/gadget/legacy/tcm_usb_gadget.c
index 3a494168661e..7ea2a44cb228 100644
--- a/drivers/usb/gadget/legacy/tcm_usb_gadget.c
+++ b/drivers/usb/gadget/legacy/tcm_usb_gadget.c
@@ -29,7 +29,7 @@
 
 USB_GADGET_COMPOSITE_OPTIONS();
 
-static struct target_fabric_configfs *usbg_fabric_configfs;
+static const struct target_core_fabric_ops usbg_ops;
 
 static inline struct f_uas *to_f_uas(struct usb_function *f)
 {
@@ -1572,8 +1572,7 @@ static struct se_portal_group *usbg_make_tpg(
         tpg->tport = tport;
         tpg->tport_tpgt = tpgt;
 
-        ret = core_tpg_register(&usbg_fabric_configfs->tf_ops, wwn,
-                                &tpg->se_tpg, tpg,
+        ret = core_tpg_register(&usbg_ops, wwn, &tpg->se_tpg, tpg,
                                 TRANSPORT_TPG_TYPE_NORMAL);
         if (ret < 0) {
                 destroy_workqueue(tpg->workqueue);
@@ -1865,7 +1864,9 @@ static int usbg_check_stop_free(struct se_cmd *se_cmd)
         return 1;
 }
 
-static struct target_core_fabric_ops usbg_ops = {
+static const struct target_core_fabric_ops usbg_ops = {
+        .module                         = THIS_MODULE,
+        .name                           = "usb_gadget",
         .get_fabric_name                = usbg_get_fabric_name,
         .get_fabric_proto_ident         = usbg_get_fabric_proto_ident,
         .tpg_get_wwn                    = usbg_get_fabric_wwn,
@@ -1907,46 +1908,9 @@ static struct target_core_fabric_ops usbg_ops = {
         .fabric_drop_np                 = NULL,
         .fabric_make_nodeacl            = usbg_make_nodeacl,
         .fabric_drop_nodeacl            = usbg_drop_nodeacl,
-};
-
-static int usbg_register_configfs(void)
-{
-        struct target_fabric_configfs *fabric;
-        int ret;
-
-        fabric = target_fabric_configfs_init(THIS_MODULE, "usb_gadget");
-        if (IS_ERR(fabric)) {
-                printk(KERN_ERR "target_fabric_configfs_init() failed\n");
-                return PTR_ERR(fabric);
-        }
-
-        fabric->tf_ops = usbg_ops;
-        fabric->tf_cit_tmpl.tfc_wwn_cit.ct_attrs = usbg_wwn_attrs;
-        fabric->tf_cit_tmpl.tfc_tpg_base_cit.ct_attrs = usbg_base_attrs;
-        fabric->tf_cit_tmpl.tfc_tpg_attrib_cit.ct_attrs = NULL;
-        fabric->tf_cit_tmpl.tfc_tpg_param_cit.ct_attrs = NULL;
-        fabric->tf_cit_tmpl.tfc_tpg_np_base_cit.ct_attrs = NULL;
-        fabric->tf_cit_tmpl.tfc_tpg_nacl_base_cit.ct_attrs = NULL;
-        fabric->tf_cit_tmpl.tfc_tpg_nacl_attrib_cit.ct_attrs = NULL;
-        fabric->tf_cit_tmpl.tfc_tpg_nacl_auth_cit.ct_attrs = NULL;
-        fabric->tf_cit_tmpl.tfc_tpg_nacl_param_cit.ct_attrs = NULL;
-        ret = target_fabric_configfs_register(fabric);
-        if (ret < 0) {
-                printk(KERN_ERR "target_fabric_configfs_register() failed"
-                                " for usb-gadget\n");
-                return ret;
-        }
-        usbg_fabric_configfs = fabric;
-        return 0;
-};
 
-static void usbg_deregister_configfs(void)
-{
-        if (!(usbg_fabric_configfs))
-                return;
-
-        target_fabric_configfs_deregister(usbg_fabric_configfs);
-        usbg_fabric_configfs = NULL;
+        .tfc_wwn_attrs                  = usbg_wwn_attrs,
+        .tfc_tpg_base_attrs             = usbg_base_attrs,
 };
 
 /* Start gadget.c code */
@@ -2455,16 +2419,13 @@ static void usbg_detach(struct usbg_tpg *tpg)
 
 static int __init usb_target_gadget_init(void)
 {
-        int ret;
-
-        ret = usbg_register_configfs();
-        return ret;
+        return target_register_template(&usbg_ops);
 }
 module_init(usb_target_gadget_init);
 
 static void __exit usb_target_gadget_exit(void)
 {
-        usbg_deregister_configfs();
+        target_unregister_template(&usbg_ops);
 }
 module_exit(usb_target_gadget_exit);