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, 63 deletions

diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 27ed9642cc21..e8c88b453f79 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -216,9 +216,7 @@ struct vhost_scsi {
         int vs_events_nr; /* num of pending events, protected by vq->mutex */
 };
 
-/* Local pointer to allocated TCM configfs fabric module */
-static struct target_fabric_configfs *vhost_scsi_fabric_configfs;
-
+static struct target_core_fabric_ops vhost_scsi_ops;
 static struct workqueue_struct *vhost_scsi_workqueue;
 
 /* Global spinlock to protect vhost_scsi TPG list for vhost IOCTL access */
@@ -2205,7 +2203,7 @@ vhost_scsi_make_tpg(struct se_wwn *wwn,
         tpg->tport = tport;
         tpg->tport_tpgt = tpgt;
 
-        ret = core_tpg_register(&vhost_scsi_fabric_configfs->tf_ops, wwn,
+        ret = core_tpg_register(&vhost_scsi_ops, wwn,
                                 &tpg->se_tpg, tpg, TRANSPORT_TPG_TYPE_NORMAL);
         if (ret < 0) {
                 kfree(tpg);
@@ -2327,6 +2325,8 @@ static struct configfs_attribute *vhost_scsi_wwn_attrs[] = {
 };
 
 static struct target_core_fabric_ops vhost_scsi_ops = {
+        .module                         = THIS_MODULE,
+        .name                           = "vhost",
         .get_fabric_name                = vhost_scsi_get_fabric_name,
         .get_fabric_proto_ident         = vhost_scsi_get_fabric_proto_ident,
         .tpg_get_wwn                    = vhost_scsi_get_fabric_wwn,
@@ -2371,70 +2371,20 @@ static struct target_core_fabric_ops vhost_scsi_ops = {
         .fabric_drop_np                 = NULL,
         .fabric_make_nodeacl            = vhost_scsi_make_nodeacl,
         .fabric_drop_nodeacl            = vhost_scsi_drop_nodeacl,
+
+        .tfc_wwn_attrs                  = vhost_scsi_wwn_attrs,
+        .tfc_tpg_base_attrs             = vhost_scsi_tpg_attrs,
+        .tfc_tpg_attrib_attrs           = vhost_scsi_tpg_attrib_attrs,
 };
 
-static int vhost_scsi_register_configfs(void)
+static int __init vhost_scsi_init(void)
 {
-        struct target_fabric_configfs *fabric;
-        int ret;
+        int ret = -ENOMEM;
 
-        pr_debug("vhost-scsi fabric module %s on %s/%s"
+        pr_debug("TCM_VHOST fabric module %s on %s/%s"
                 " on "UTS_RELEASE"\n", VHOST_SCSI_VERSION, utsname()->sysname,
                 utsname()->machine);
-        /*
-         * Register the top level struct config_item_type with TCM core
-         */
-        fabric = target_fabric_configfs_init(THIS_MODULE, "vhost");
-        if (IS_ERR(fabric)) {
-                pr_err("target_fabric_configfs_init() failed\n");
-                return PTR_ERR(fabric);
-        }
-        /*
-         * Setup fabric->tf_ops from our local vhost_scsi_ops
-         */
-        fabric->tf_ops = vhost_scsi_ops;
-        /*
-         * Setup default attribute lists for various fabric->tf_cit_tmpl
-         */
-        fabric->tf_cit_tmpl.tfc_wwn_cit.ct_attrs = vhost_scsi_wwn_attrs;
-        fabric->tf_cit_tmpl.tfc_tpg_base_cit.ct_attrs = vhost_scsi_tpg_attrs;
-        fabric->tf_cit_tmpl.tfc_tpg_attrib_cit.ct_attrs = vhost_scsi_tpg_attrib_attrs;
-        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;
-        /*
-         * Register the fabric for use within TCM
-         */
-        ret = target_fabric_configfs_register(fabric);
-        if (ret < 0) {
-                pr_err("target_fabric_configfs_register() failed"
-                                " for TCM_VHOST\n");
-                return ret;
-        }
-        /*
-         * Setup our local pointer to *fabric
-         */
-        vhost_scsi_fabric_configfs = fabric;
-        pr_debug("TCM_VHOST[0] - Set fabric -> vhost_scsi_fabric_configfs\n");
-        return 0;
-};
-
-static void vhost_scsi_deregister_configfs(void)
-{
-        if (!vhost_scsi_fabric_configfs)
-                return;
-
-        target_fabric_configfs_deregister(vhost_scsi_fabric_configfs);
-        vhost_scsi_fabric_configfs = NULL;
-        pr_debug("TCM_VHOST[0] - Cleared vhost_scsi_fabric_configfs\n");
-};
 
-static int __init vhost_scsi_init(void)
-{
-        int ret = -ENOMEM;
         /*
          * Use our own dedicated workqueue for submitting I/O into
          * target core to avoid contention within system_wq.
@@ -2447,7 +2397,7 @@ static int __init vhost_scsi_init(void)
         if (ret < 0)
                 goto out_destroy_workqueue;
 
-        ret = vhost_scsi_register_configfs();
+        ret = target_register_template(&vhost_scsi_ops);
         if (ret < 0)
                 goto out_vhost_scsi_deregister;
 
@@ -2463,7 +2413,7 @@ out:
 
 static void vhost_scsi_exit(void)
 {
-        vhost_scsi_deregister_configfs();
+        target_unregister_template(&vhost_scsi_ops);
         vhost_scsi_deregister();
         destroy_workqueue(vhost_scsi_workqueue);
 };