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, 13 insertions, 61 deletions

diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
index 61653a03a8f5..f8a1bd741b5d 100644
--- a/drivers/xen/xen-scsiback.c
+++ b/drivers/xen/xen-scsiback.c
@@ -205,8 +205,7 @@ static LIST_HEAD(scsiback_free_pages);
 static DEFINE_MUTEX(scsiback_mutex);
 static LIST_HEAD(scsiback_list);
 
-/* Local pointer to allocated TCM configfs fabric module */
-static struct target_fabric_configfs *scsiback_fabric_configfs;
+static const struct target_core_fabric_ops scsiback_ops;
 
 static void scsiback_get(struct vscsibk_info *info)
 {
@@ -1901,7 +1900,7 @@ scsiback_make_tpg(struct se_wwn *wwn,
         tpg->tport = tport;
         tpg->tport_tpgt = tpgt;
 
-        ret = core_tpg_register(&scsiback_fabric_configfs->tf_ops, wwn,
+        ret = core_tpg_register(&scsiback_ops, wwn,
                                 &tpg->se_tpg, tpg, TRANSPORT_TPG_TYPE_NORMAL);
         if (ret < 0) {
                 kfree(tpg);
@@ -1943,7 +1942,9 @@ static int scsiback_check_false(struct se_portal_group *se_tpg)
         return 0;
 }
 
-static struct target_core_fabric_ops scsiback_ops = {
+static const struct target_core_fabric_ops scsiback_ops = {
+        .module                         = THIS_MODULE,
+        .name                           = "xen-pvscsi",
         .get_fabric_name                = scsiback_get_fabric_name,
         .get_fabric_proto_ident         = scsiback_get_fabric_proto_ident,
         .tpg_get_wwn                    = scsiback_get_fabric_wwn,
@@ -1990,62 +1991,10 @@ static struct target_core_fabric_ops scsiback_ops = {
         .fabric_make_nodeacl            = scsiback_make_nodeacl,
         .fabric_drop_nodeacl            = scsiback_drop_nodeacl,
 #endif
-};
-
-static int scsiback_register_configfs(void)
-{
-        struct target_fabric_configfs *fabric;
-        int ret;
 
-        pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n",
-                 VSCSI_VERSION, utsname()->sysname, utsname()->machine);
-        /*
-         * Register the top level struct config_item_type with TCM core
-         */
-        fabric = target_fabric_configfs_init(THIS_MODULE, "xen-pvscsi");
-        if (IS_ERR(fabric))
-                return PTR_ERR(fabric);
-
-        /*
-         * Setup fabric->tf_ops from our local scsiback_ops
-         */
-        fabric->tf_ops = scsiback_ops;
-        /*
-         * Setup default attribute lists for various fabric->tf_cit_tmpl
-         */
-        fabric->tf_cit_tmpl.tfc_wwn_cit.ct_attrs = scsiback_wwn_attrs;
-        fabric->tf_cit_tmpl.tfc_tpg_base_cit.ct_attrs = scsiback_tpg_attrs;
-        fabric->tf_cit_tmpl.tfc_tpg_attrib_cit.ct_attrs = NULL;
-        fabric->tf_cit_tmpl.tfc_tpg_param_cit.ct_attrs = scsiback_param_attrs;
-        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;
-        /*
-         * Register the fabric for use within TCM
-         */
-        ret = target_fabric_configfs_register(fabric);
-        if (ret < 0) {
-                target_fabric_configfs_free(fabric);
-                return ret;
-        }
-        /*
-         * Setup our local pointer to *fabric
-         */
-        scsiback_fabric_configfs = fabric;
-        pr_debug("xen-pvscsi: Set fabric -> scsiback_fabric_configfs\n");
-        return 0;
-};
-
-static void scsiback_deregister_configfs(void)
-{
-        if (!scsiback_fabric_configfs)
-                return;
-
-        target_fabric_configfs_deregister(scsiback_fabric_configfs);
-        scsiback_fabric_configfs = NULL;
-        pr_debug("xen-pvscsi: Cleared scsiback_fabric_configfs\n");
+        .tfc_wwn_attrs                  = scsiback_wwn_attrs,
+        .tfc_tpg_base_attrs             = scsiback_tpg_attrs,
+        .tfc_tpg_param_attrs            = scsiback_param_attrs,
 };
 
 static const struct xenbus_device_id scsiback_ids[] = {
@@ -2077,6 +2026,9 @@ static int __init scsiback_init(void)
         if (!xen_domain())
                 return -ENODEV;
 
+        pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n",
+                 VSCSI_VERSION, utsname()->sysname, utsname()->machine);
+
         scsiback_cachep = kmem_cache_create("vscsiif_cache",
                 sizeof(struct vscsibk_pend), 0, 0, scsiback_init_pend);
         if (!scsiback_cachep)
@@ -2086,7 +2038,7 @@ static int __init scsiback_init(void)
         if (ret)
                 goto out_cache_destroy;
 
-        ret = scsiback_register_configfs();
+        ret = target_register_template(&scsiback_ops);
         if (ret)
                 goto out_unregister_xenbus;
 
@@ -2109,7 +2061,7 @@ static void __exit scsiback_exit(void)
                         BUG();
                 gnttab_free_pages(1, &page);
         }
-        scsiback_deregister_configfs();
+        target_unregister_template(&scsiback_ops);
         xenbus_unregister_driver(&scsiback_driver);
         kmem_cache_destroy(scsiback_cachep);
 }