subsystem: make subsystem declaration macro just register subsystem

Don't do anything under the scene as adding/removing fields in struct
spdk_subsystem will require both macro change and C file changes.

Change-Id: I11bc0d5758edd7e0e0bd3f93e251d868cd9b1d2b
Signed-off-by: Pawel Wodkowski <pawelx.wodkowski@intel.com>
Reviewed-on: https://review.gerrithub.io/401850
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>

include/spdk_internal/event.h

@@ -66,7 +66,6 @@ extern struct spdk_subsystem_list g_subsystems;
 struct spdk_subsystem_depend {
 	const char *name;
 	const char *depends_on;
-	struct spdk_subsystem *depends_on_subsystem;
 	TAILQ_ENTRY(spdk_subsystem_depend) tailq;
 };
 
@@ -88,27 +87,19 @@ void spdk_rpc_finish(void);
 /**
  * \brief Register a new subsystem
  */
-#define SPDK_SUBSYSTEM_REGISTER(_name, _init, _fini, _config)			\
+#define SPDK_SUBSYSTEM_REGISTER(_name) \
-	struct spdk_subsystem __spdk_subsystem_ ## _name = {			\
-	.name = #_name,								\
-	.init = _init,								\
-	.fini = _fini,								\
-	.config = _config,							\
-	};									\
 	__attribute__((constructor)) static void _name ## _register(void)	\
 	{									\
-		spdk_add_subsystem(&__spdk_subsystem_ ## _name);		\
+		spdk_add_subsystem(&_name);					\
 	}
 
 /**
  * \brief Declare that a subsystem depends on another subsystem.
  */
 #define SPDK_SUBSYSTEM_DEPEND(_name, _depends_on)						\
-	extern struct spdk_subsystem __spdk_subsystem_ ## _depends_on;				\
 	static struct spdk_subsystem_depend __subsystem_ ## _name ## _depend_on ## _depends_on = { \
 	.name = #_name,										\
 	.depends_on = #_depends_on,								\
-	.depends_on_subsystem = &__spdk_subsystem_ ## _depends_on,				\
 	};											\
 	__attribute__((constructor)) static void _name ## _depend_on ## _depends_on(void)	\
 	{											\

lib/event/subsystems/bdev/bdev.c

@@ -64,6 +64,12 @@ spdk_bdev_subsystem_finish(void)
 	spdk_bdev_finish(spdk_bdev_subsystem_finish_done, NULL);
 }
 
-SPDK_SUBSYSTEM_REGISTER(bdev, spdk_bdev_subsystem_initialize,
+static struct spdk_subsystem g_spdk_subsystem_bdev = {
-			spdk_bdev_subsystem_finish, spdk_bdev_config_text)
+	.name = "bdev",
+	.init = spdk_bdev_subsystem_initialize,
+	.fini = spdk_bdev_subsystem_finish,
+	.config = spdk_bdev_config_text,
+};
+
+SPDK_SUBSYSTEM_REGISTER(g_spdk_subsystem_bdev);
 SPDK_SUBSYSTEM_DEPEND(bdev, copy)

lib/event/subsystems/copy/copy.c

@@ -60,5 +60,11 @@ spdk_copy_engine_subsystem_finish(void)
 	spdk_copy_engine_finish(spdk_copy_engine_subsystem_finish_done, NULL);
 }
 
-SPDK_SUBSYSTEM_REGISTER(copy, spdk_copy_engine_subsystem_initialize,
+static struct spdk_subsystem g_spdk_subsystem_copy = {
-			spdk_copy_engine_subsystem_finish, NULL)
+	.name = "copy",
+	.init = spdk_copy_engine_subsystem_initialize,
+	.fini = spdk_copy_engine_subsystem_finish,
+	.config = NULL,
+};
+
+SPDK_SUBSYSTEM_REGISTER(g_spdk_subsystem_copy);

lib/event/subsystems/iscsi/iscsi.c

@@ -61,6 +61,12 @@ spdk_iscsi_subsystem_fini(void)
 	spdk_iscsi_fini(spdk_iscsi_subsystem_fini_done, NULL);
 }
 
-SPDK_SUBSYSTEM_REGISTER(iscsi, spdk_iscsi_subsystem_init, spdk_iscsi_subsystem_fini,
+static struct spdk_subsystem g_spdk_subsystem_iscsi = {
-			spdk_iscsi_config_text)
+	.name = "iscsi",
+	.init = spdk_iscsi_subsystem_init,
+	.fini = spdk_iscsi_subsystem_fini,
+	.config = spdk_iscsi_config_text,
+};
+
+SPDK_SUBSYSTEM_REGISTER(g_spdk_subsystem_iscsi);
 SPDK_SUBSYSTEM_DEPEND(iscsi, scsi)

lib/event/subsystems/nbd/nbd.c

@@ -54,5 +54,12 @@ spdk_nbd_subsystem_fini(void)
 	spdk_subsystem_fini_next();
 }
 
-SPDK_SUBSYSTEM_REGISTER(nbd, spdk_nbd_subsystem_init, spdk_nbd_subsystem_fini, NULL)
+static struct spdk_subsystem g_spdk_subsystem_nbd = {
+	.name = "nbd",
+	.init = spdk_nbd_subsystem_init,
+	.fini = spdk_nbd_subsystem_fini,
+	.config = NULL,
+};
+
+SPDK_SUBSYSTEM_REGISTER(g_spdk_subsystem_nbd);
 SPDK_SUBSYSTEM_DEPEND(nbd, bdev)

lib/event/subsystems/net/net.c

@@ -54,8 +54,14 @@ spdk_interface_subsystem_destroy(void)
 	spdk_subsystem_fini_next();
 }
 
-SPDK_SUBSYSTEM_REGISTER(interface, spdk_interface_subsystem_init,
+static struct spdk_subsystem g_spdk_subsystem_interface = {
-			spdk_interface_subsystem_destroy, NULL)
+	.name = "interface",
+	.init = spdk_interface_subsystem_init,
+	.fini = spdk_interface_subsystem_destroy,
+	.config = NULL,
+};
+
+SPDK_SUBSYSTEM_REGISTER(g_spdk_subsystem_interface);
 
 static void
 spdk_net_subsystem_start(void)
@@ -74,6 +80,12 @@ spdk_net_subsystem_fini(void)
 	spdk_subsystem_fini_next();
 }
 
-SPDK_SUBSYSTEM_REGISTER(net_framework, spdk_net_subsystem_start,
+static struct spdk_subsystem g_spdk_subsystem_net_framework = {
-			spdk_net_subsystem_fini, NULL)
+	.name = "net_framework",
+	.init = spdk_net_subsystem_start,
+	.fini = spdk_net_subsystem_fini,
+	.config = NULL,
+};
+
+SPDK_SUBSYSTEM_REGISTER(g_spdk_subsystem_net_framework);
 SPDK_SUBSYSTEM_DEPEND(net_framework, interface)

lib/event/subsystems/scsi/scsi.c

@@ -54,5 +54,12 @@ spdk_scsi_subsystem_fini(void)
 	spdk_subsystem_fini_next();
 }
 
-SPDK_SUBSYSTEM_REGISTER(scsi, spdk_scsi_subsystem_init, spdk_scsi_subsystem_fini, NULL)
+static struct spdk_subsystem g_spdk_subsystem_scsi = {
+	.name = "scsi",
+	.init = spdk_scsi_subsystem_init,
+	.fini = spdk_scsi_subsystem_fini,
+	.config = NULL,
+};
+
+SPDK_SUBSYSTEM_REGISTER(g_spdk_subsystem_scsi);
 SPDK_SUBSYSTEM_DEPEND(scsi, bdev)

lib/event/subsystems/vhost/vhost.c

@@ -59,5 +59,12 @@ spdk_vhost_subsystem_fini(void)
 	spdk_vhost_fini(spdk_vhost_subsystem_fini_done);
 }
 
-SPDK_SUBSYSTEM_REGISTER(vhost, spdk_vhost_subsystem_init, spdk_vhost_subsystem_fini, NULL)
+static struct spdk_subsystem g_spdk_subsystem_vhost = {
+	.name = "vhost",
+	.init = spdk_vhost_subsystem_init,
+	.fini = spdk_vhost_subsystem_fini,
+	.config = NULL,
+};
+
+SPDK_SUBSYSTEM_REGISTER(g_spdk_subsystem_vhost);
 SPDK_SUBSYSTEM_DEPEND(vhost, scsi)

test/unit/lib/event/subsystem.c/subsystem_ut.c

@@ -202,10 +202,26 @@ subsystem_sort_test_depends_on_multiple(void)
 	TAILQ_REMOVE(&g_subsystems, subsystem, tailq);
 }
 
-SPDK_SUBSYSTEM_REGISTER(subsystem1, NULL, NULL, NULL)
+struct spdk_subsystem subsystem1 = {
-SPDK_SUBSYSTEM_REGISTER(subsystem2, NULL, NULL, NULL)
+	.name = "subsystem1",
-SPDK_SUBSYSTEM_REGISTER(subsystem3, NULL, NULL, NULL)
+};
-SPDK_SUBSYSTEM_REGISTER(subsystem4, NULL, NULL, NULL)
+
+struct spdk_subsystem subsystem2 = {
+	.name = "subsystem2",
+};
+struct spdk_subsystem subsystem3 = {
+	.name = "subsystem3",
+};
+
+struct spdk_subsystem subsystem4 = {
+	.name = "subsystem4",
+};
+
+SPDK_SUBSYSTEM_REGISTER(subsystem1);
+SPDK_SUBSYSTEM_REGISTER(subsystem2);
+SPDK_SUBSYSTEM_REGISTER(subsystem3);
+SPDK_SUBSYSTEM_REGISTER(subsystem4);
+
 SPDK_SUBSYSTEM_DEPEND(subsystem1, subsystem2)
 SPDK_SUBSYSTEM_DEPEND(subsystem2, subsystem3)
 SPDK_SUBSYSTEM_DEPEND(subsystem3, subsystem4)