subsystem,bdev: rework RPC JSON config dump

Changes:
- change write_config_json to return void as return value is useless.
- int spdk_bdev_config_json() -> void spdk_bdev_subsystem_config_json()
- int spdk_bdev_write_config_json -> void spdk_bdev_config_json()

Change-Id: I46e2e974abada0df67c07ba961543900f8334a8d
Signed-off-by: Pawel Wodkowski <pawelx.wodkowski@intel.com>
Reviewed-on: https://review.gerrithub.io/405052
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>

include/spdk/bdev.h

@@ -151,11 +151,9 @@ void spdk_bdev_config_text(FILE *fp);
 /**
  * Get the full configuration options for the registered block device modules and created bdevs.
  *
- * \param w The pointer to a JSON write context where the configuration will be written.
- * \return result of \c spdk_bdev_dump_bdev_config_json() or negative error code:
- * -EINVAL if w == NULL
+ * \param w pointer to a JSON write context where the configuration will be written.
  */
-int spdk_bdev_config_json(struct spdk_json_write_ctx *w);
+void spdk_bdev_subsystem_config_json(struct spdk_json_write_ctx *w);
 
 /**
  * Get block device by the block device name.
@@ -262,13 +260,10 @@ int spdk_bdev_dump_info_json(struct spdk_bdev *bdev, struct spdk_json_write_ctx
  * If \c bdev does not support writing JSON configuration then object will be written
  * with only one key - the name of this bdev.
  *
- * \param w JSON write context. It will store the driver-specific configuration context.
  * \param bdev block device to query configuration.
- * \return 0 on success, negated errno on failure.
- *  -EINVAL - bdev == NULL or w == NULL
- *  -ENOSYS - this block device doesn't support dumping configuration.
+ * \param w pointer to a JSON write context where \c bdev the configuration will be written.
  */
-int spdk_bdev_write_config_json(struct spdk_bdev *bdev, struct spdk_json_write_ctx *w);
+void spdk_bdev_config_json(struct spdk_bdev *bdev, struct spdk_json_write_ctx *w);
 
 /**
  * Get block device name.

include/spdk_internal/event.h

@@ -58,7 +58,7 @@ struct spdk_subsystem {
 	void (*init)(void);
 	void (*fini)(void);
 	void (*config)(FILE *fp);
-	int (*write_config_json)(struct spdk_json_write_ctx *w);
+	void (*write_config_json)(struct spdk_json_write_ctx *w);
 	TAILQ_ENTRY(spdk_subsystem) tailq;
 };
 

lib/bdev/bdev.c

@@ -426,15 +426,13 @@ spdk_bdev_config_text(FILE *fp)
 	}
 }
 
-int
-spdk_bdev_config_json(struct spdk_json_write_ctx *w)
+void
+spdk_bdev_subsystem_config_json(struct spdk_json_write_ctx *w)
 {
 	struct spdk_bdev_module *bdev_module;
 	struct spdk_bdev *bdev;
 
-	if (!w) {
-		return -EINVAL;
-	}
+	assert(w != NULL);
 
 	spdk_json_write_array_begin(w);
 
@@ -445,11 +443,10 @@ spdk_bdev_config_json(struct spdk_json_write_ctx *w)
 	}
 
 	TAILQ_FOREACH(bdev, &g_bdev_mgr.bdevs, link) {
-		spdk_bdev_write_config_json(bdev, w);
+		spdk_bdev_config_json(bdev, w);
 	}
 
 	spdk_json_write_array_end(w);
-	return 0;
 }
 
 static int
@@ -978,12 +975,11 @@ spdk_bdev_dump_info_json(struct spdk_bdev *bdev, struct spdk_json_write_ctx *w)
 	return 0;
 }
 
-int
-spdk_bdev_write_config_json(struct spdk_bdev *bdev, struct spdk_json_write_ctx *w)
+void
+spdk_bdev_config_json(struct spdk_bdev *bdev, struct spdk_json_write_ctx *w)
 {
-	if (bdev == NULL || w == NULL) {
-		return -EINVAL;
-	}
+	assert(bdev == NULL);
+	assert(w == NULL);
 
 	if (bdev->fn_table->write_config_json) {
 		bdev->fn_table->write_config_json(bdev, w);
@@ -992,8 +988,6 @@ spdk_bdev_write_config_json(struct spdk_bdev *bdev, struct spdk_json_write_ctx *
 		spdk_json_write_named_string(w, "name", bdev->name);
 		spdk_json_write_object_end(w);
 	}
-
-	return 0;
 }
 
 static void

lib/bdev/rpc/bdev_rpc.c

@@ -226,10 +226,10 @@ spdk_rpc_get_bdevs_config(struct spdk_jsonrpc_request *request,
 
 	spdk_json_write_array_begin(w);
 	if (bdev != NULL) {
-		spdk_bdev_write_config_json(bdev, w);
+		spdk_bdev_config_json(bdev, w);
 	} else {
 		for (bdev = spdk_bdev_first(); bdev != NULL; bdev = spdk_bdev_next(bdev)) {
-			spdk_bdev_write_config_json(bdev, w);
+			spdk_bdev_config_json(bdev, w);
 		}
 	}
 

lib/event/subsystems/bdev/bdev.c

@@ -69,7 +69,7 @@ static struct spdk_subsystem g_spdk_subsystem_bdev = {
 	.init = spdk_bdev_subsystem_initialize,
 	.fini = spdk_bdev_subsystem_finish,
 	.config = spdk_bdev_config_text,
-	.write_config_json = spdk_bdev_config_json,
+	.write_config_json = spdk_bdev_subsystem_config_json,
 };
 
 SPDK_SUBSYSTEM_REGISTER(g_spdk_subsystem_bdev);