event: Move json config loading to init

Loading subsystems and restoring state from a JSON config file is useful
outside of the SPDK application framework, so move it to lib/init.

Change-Id: I7dd3ceace2e7b1b28eef83c91ce6a4eedc85740e
Signed-off-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/6645
Reviewed-by: Tom Nabarro <tom.nabarro@outlook.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Aleksey Marchuk <alexeymar@mellanox.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Community-CI: Mellanox Build Bot

examples/bdev/fio_plugin/fio_plugin.c

@@ -219,8 +219,8 @@ spdk_fio_bdev_init_start(void *arg)
 {
 	bool *done = arg;
 
-	spdk_app_json_config_load(g_json_config_file, SPDK_DEFAULT_RPC_ADDR,
-				  spdk_fio_bdev_init_done, done, true);
+	spdk_subsystem_init_from_json_config(g_json_config_file, SPDK_DEFAULT_RPC_ADDR,
+					     spdk_fio_bdev_init_done, done, true);
 }
 
 static void

include/spdk/init.h

@@ -76,6 +76,20 @@ typedef void (*spdk_subsystem_init_fn)(int rc, void *ctx);
  */
 void spdk_subsystem_init(spdk_subsystem_init_fn cb_fn, void *cb_arg);
 
+/**
+ * Like spdk_subsystem_init, but additionally configure each subsystem using the provided JSON config
+ * file. This will automatically start a JSON RPC server and then stop it.
+ *
+ * \param json_config_file Path to a JSON config file.
+ * \param rpc_addr Path to a unix domain socket to send configuration RPCs to.
+ * \param cb_fn Function called when the process is complete.
+ * \param cb_arg User context passed to cb_fn.
+ * \param stop_on_error Whether to stop initialization if one of the JSON RPCs fails.
+ */
+void spdk_subsystem_init_from_json_config(const char *json_config_file, const char *rpc_addr,
+		spdk_subsystem_init_fn cb_fn, void *cb_arg,
+		bool stop_on_error);
+
 typedef void (*spdk_subsystem_fini_fn)(void *ctx);
 
 /**

include/spdk_internal/event.h

@@ -164,12 +164,6 @@ int spdk_reactor_set_interrupt_mode(uint32_t lcore, bool new_in_interrupt,
  */
 struct spdk_thread *_spdk_get_app_thread(void);
 
-typedef void (*spdk_app_init_fn)(int rc, void *ctx);
-
-void spdk_app_json_config_load(const char *json_config_file, const char *rpc_addr,
-			       spdk_app_init_fn cb_fn, void *cb_arg,
-			       bool stop_on_error);
-
 struct spdk_governor_capabilities {
 	bool freq_change;
 	bool freq_getset;

lib/event/Makefile

@@ -40,7 +40,7 @@ SO_MINOR := 0
 CFLAGS += $(ENV_CFLAGS)
 
 LIBNAME = event
-C_SRCS = app.c reactor.c json_config.c log_rpc.c \
+C_SRCS = app.c reactor.c log_rpc.c \
 	 app_rpc.c scheduler_static.c
 
 # Do not compile schedulers and governors based on DPDK env

lib/event/app.c

@@ -403,8 +403,9 @@ bootstrap_fn(void *arg1)
 
 	if (g_spdk_app.json_config_file) {
 		g_delay_subsystem_init = false;
-		spdk_app_json_config_load(g_spdk_app.json_config_file, g_spdk_app.rpc_addr, app_start_rpc,
-					  NULL, !g_spdk_app.json_config_ignore_errors);
+		spdk_subsystem_init_from_json_config(g_spdk_app.json_config_file, g_spdk_app.rpc_addr,
+						     app_start_rpc,
+						     NULL, !g_spdk_app.json_config_ignore_errors);
 	} else {
 		if (!g_delay_subsystem_init) {
 			spdk_subsystem_init(app_start_rpc, NULL);

lib/event/spdk_event.map

@@ -25,7 +25,6 @@
 	spdk_reactor_get;
 	spdk_for_each_reactor;
 	spdk_reactor_set_interrupt_mode;
-	spdk_app_json_config_load;
 
 	local: *;
 };

lib/init/Makefile

@@ -37,7 +37,7 @@ include $(SPDK_ROOT_DIR)/mk/spdk.common.mk
 SO_VER := 1
 SO_MINOR := 0
 
-C_SRCS = subsystem.c subsystem_rpc.c rpc.c
+C_SRCS = json_config.c subsystem.c subsystem_rpc.c rpc.c
 LIBNAME = init
 
 SPDK_MAP_FILE = $(abspath $(CURDIR)/spdk_init.map)

lib/init/json_config.c

@@ -86,7 +86,7 @@ typedef void (*client_resp_handler)(struct load_json_config_ctx *,
 struct load_json_config_ctx {
 	/* Thread used during configuration. */
 	struct spdk_thread *thread;
-	spdk_app_init_fn cb_fn;
+	spdk_subsystem_init_fn cb_fn;
 	void *cb_arg;
 	bool stop_on_error;
 
@@ -567,9 +567,9 @@ err:
 }
 
 void
-spdk_app_json_config_load(const char *json_config_file, const char *rpc_addr,
-			  spdk_app_init_fn cb_fn, void *cb_arg,
-			  bool stop_on_error)
+spdk_subsystem_init_from_json_config(const char *json_config_file, const char *rpc_addr,
+				     spdk_subsystem_init_fn cb_fn, void *cb_arg,
+				     bool stop_on_error)
 {
 	struct load_json_config_ctx *ctx = calloc(1, sizeof(*ctx));
 	int rc;

lib/init/spdk_init.map

@@ -8,6 +8,7 @@
 	spdk_subsystem_fini;
 	spdk_subsystem_init_next;
 	spdk_subsystem_fini_next;
+	spdk_subsystem_init_from_json_config;
 
 	spdk_rpc_initialize;
 	spdk_rpc_finish;

mk/spdk.lib_deps.mk

@@ -84,7 +84,7 @@ DEPDIRS-trace := log util $(JSON_LIBS)
 DEPDIRS-bdev := log util thread $(JSON_LIBS) notify trace
 DEPDIRS-blobfs := log thread blob trace
 DEPDIRS-event := log util thread $(JSON_LIBS) trace init
-DEPDIRS-init := jsonrpc json log rpc thread
+DEPDIRS-init := jsonrpc json log rpc thread util
 
 DEPDIRS-ftl := log util thread trace bdev
 DEPDIRS-nbd := log util thread $(JSON_LIBS) bdev

test/unit/lib/event/app.c/app_ut.c

@@ -51,7 +51,8 @@ DEFINE_STUB_V(spdk_rpc_set_state, (uint32_t state));
 DEFINE_STUB(spdk_rpc_get_state, uint32_t, (void), SPDK_RPC_RUNTIME);
 DEFINE_STUB(spdk_rpc_initialize, int, (const char *listen_addr), 0);
 DEFINE_STUB_V(spdk_rpc_finish, (void));
-DEFINE_STUB_V(spdk_app_json_config_load, (const char *json_config_file, const char *rpc_addr,
+DEFINE_STUB_V(spdk_subsystem_init_from_json_config, (const char *json_config_file,
+		const char *rpc_addr,
 		spdk_subsystem_init_fn cb_fn, void *cb_arg, bool stop_on_error));
 DEFINE_STUB_V(spdk_reactors_start, (void));
 DEFINE_STUB_V(spdk_reactors_stop, (void *arg1));