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>
diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index cd611e7..5d75bb4 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -33,7 +33,6 @@
 #include <target/iscsi/iscsi_target_core.h>
 #include "iscsi_target_parameters.h"
 #include "iscsi_target_seq_pdu_list.h"
-#include "iscsi_target_configfs.h"
 #include "iscsi_target_datain_values.h"
 #include "iscsi_target_erl0.h"
 #include "iscsi_target_erl1.h"
@@ -551,8 +550,8 @@
 	idr_init(&tiqn_idr);
 	idr_init(&sess_idr);
 
-	ret = iscsi_target_register_configfs();
-	if (ret < 0)
+	ret = target_register_template(&iscsi_ops);
+	if (ret)
 		goto out;
 
 	size = BITS_TO_LONGS(ISCSIT_BITMAP_BITS) * sizeof(long);
@@ -616,7 +615,10 @@
 bitmap_out:
 	vfree(iscsit_global->ts_bitmap);
 configfs_out:
-	iscsi_target_deregister_configfs();
+	/* XXX: this probably wants it to be it's own unwind step.. */
+	if (iscsit_global->discovery_tpg)
+		iscsit_tpg_disable_portal_group(iscsit_global->discovery_tpg, 1);
+	target_unregister_template(&iscsi_ops);
 out:
 	kfree(iscsit_global);
 	return -ENOMEM;
@@ -631,7 +633,13 @@
 	kmem_cache_destroy(lio_ooo_cache);
 	kmem_cache_destroy(lio_r2t_cache);
 
-	iscsi_target_deregister_configfs();
+	/*
+	 * Shutdown discovery sessions and disable discovery TPG
+	 */
+	if (iscsit_global->discovery_tpg)
+		iscsit_tpg_disable_portal_group(iscsit_global->discovery_tpg, 1);
+
+	target_unregister_template(&iscsi_ops);
 
 	vfree(iscsit_global->ts_bitmap);
 	kfree(iscsit_global);
@@ -983,7 +991,7 @@
 	/*
 	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
 	 */
-	transport_init_se_cmd(&cmd->se_cmd, &lio_target_fabric_configfs->tf_ops,
+	transport_init_se_cmd(&cmd->se_cmd, &iscsi_ops,
 			conn->sess->se_sess, be32_to_cpu(hdr->data_length),
 			cmd->data_direction, sam_task_attr,
 			cmd->sense_buffer + 2);
@@ -1798,8 +1806,7 @@
 		u8 tcm_function;
 		int ret;
 
-		transport_init_se_cmd(&cmd->se_cmd,
-				      &lio_target_fabric_configfs->tf_ops,
+		transport_init_se_cmd(&cmd->se_cmd, &iscsi_ops,
 				      conn->sess->se_sess, 0, DMA_NONE,
 				      TCM_SIMPLE_TAG, cmd->sense_buffer + 2);