app: added --json-ignore-init-errors

If set, SPDK will continue loading the JSON config even if
some commands caused an error. This can be useful when loading
RPC config from spdk_tgt into e.g. bdevperf, which supports
only a subset of RPC commands and would usually fail with
"Method not found" message.

Resolves #840

Change-Id: I070fea862fd99e5882d870e11e6a28dc9d0c8ba6
Signed-off-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/620
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>

CHANGELOG.md

@@ -6,6 +6,11 @@
 A new function, `spdk_vmd_fini`, has been added. It releases all resources acquired by the VMD
 library through the `spdk_vmd_init` call.
 
+### Miscellaneous
+
+`--json-ignore-init-errors` command line param has been added to ignore initialization errors
+on JSON config load.
+
 ## v20.01
 
 ### bdev

examples/bdev/fio_plugin/fio_plugin.c

@@ -204,7 +204,7 @@ spdk_fio_bdev_init_start(void *arg)
 
 	if (g_json_config_file != NULL) {
 		spdk_app_json_config_load(g_json_config_file, SPDK_DEFAULT_RPC_ADDR,
-					  spdk_fio_bdev_init_done, done);
+					  spdk_fio_bdev_init_done, done, true);
 	} else {
 		spdk_subsystem_init(spdk_fio_bdev_init_done, done);
 	}

include/spdk/event.h

@@ -91,6 +91,7 @@ struct spdk_app_opts {
 	const char *name;
 	const char *config_file;
 	const char *json_config_file;
+	bool json_config_ignore_errors;
 	const char *rpc_addr; /* Can be UNIX domain socket path or IP address + TCP port */
 	const char *reactor_mask;
 	const char *tpoint_group_mask;

include/spdk_internal/event.h

@@ -144,7 +144,8 @@ void spdk_subsystem_init_next(int rc);
 void spdk_subsystem_fini_next(void);
 void spdk_subsystem_config(FILE *fp);
 void spdk_app_json_config_load(const char *json_config_file, const char *rpc_addr,
-			       spdk_subsystem_init_fn cb_fn, void *cb_arg);
+			       spdk_subsystem_init_fn cb_fn, void *cb_arg,
+			       bool stop_on_error);
 
 /**
  * Save pointed \c subsystem configuration to the JSON write context \c w. In case of

lib/event/app.c

@@ -59,6 +59,7 @@
 struct spdk_app {
 	struct spdk_conf		*config;
 	const char			*json_config_file;
+	bool				json_config_ignore_errors;
 	const char			*rpc_addr;
 	int				shm_id;
 	spdk_app_shutdown_cb		shutdown_cb;
@@ -128,6 +129,8 @@ static const struct option g_cmdline_options[] = {
 	{"max-delay",			required_argument,	NULL, MAX_REACTOR_DELAY_OPT_IDX},
 #define JSON_CONFIG_OPT_IDX		262
 	{"json",			required_argument,	NULL, JSON_CONFIG_OPT_IDX},
+#define JSON_CONFIG_IGNORE_INIT_ERRORS_IDX	263
+	{"json-ignore-init-errors",	no_argument,		NULL, JSON_CONFIG_IGNORE_INIT_ERRORS_IDX},
 };
 
 /* Global section */
@@ -561,7 +564,7 @@ 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, spdk_app_start_rpc,
-					  NULL);
+					  NULL, !g_spdk_app.json_config_ignore_errors);
 	} else {
 		if (!g_delay_subsystem_init) {
 			spdk_subsystem_init(spdk_app_start_rpc, NULL);
@@ -626,6 +629,7 @@ spdk_app_start(struct spdk_app_opts *opts, spdk_msg_fn start_fn,
 	memset(&g_spdk_app, 0, sizeof(g_spdk_app));
 	g_spdk_app.config = config;
 	g_spdk_app.json_config_file = opts->json_config_file;
+	g_spdk_app.json_config_ignore_errors = opts->json_config_ignore_errors;
 	g_spdk_app.rpc_addr = opts->rpc_addr;
 	g_spdk_app.shm_id = opts->shm_id;
 	g_spdk_app.shutdown_cb = opts->shutdown_cb;
@@ -728,6 +732,8 @@ usage(void (*app_usage)(void))
 	       g_default_opts.config_file != NULL ? g_default_opts.config_file : "none");
 	printf("     --json <config>       JSON config file (default %s)\n",
 	       g_default_opts.json_config_file != NULL ? g_default_opts.json_config_file : "none");
+	printf("     --json-ignore-init-errors\n");
+	printf("                           don't exit on invalid config entry\n");
 	printf(" -d, --limit-coredump      do not set max coredump size to RLIM_INFINITY\n");
 	printf(" -g, --single-file-segments\n");
 	printf("                           force creating just one hugetlbfs file\n");
@@ -837,6 +843,9 @@ spdk_app_parse_args(int argc, char **argv, struct spdk_app_opts *opts,
 		case JSON_CONFIG_OPT_IDX:
 			opts->json_config_file = optarg;
 			break;
+		case JSON_CONFIG_IGNORE_INIT_ERRORS_IDX:
+			opts->json_config_ignore_errors = true;
+			break;
 		case LIMIT_COREDUMP_OPT_IDX:
 			opts->enable_coredump = false;
 			break;

lib/event/json_config.c

@@ -88,6 +88,7 @@ struct load_json_config_ctx {
 	struct spdk_thread *thread;
 	spdk_subsystem_init_fn cb_fn;
 	void *cb_arg;
+	bool stop_on_error;
 
 	/* Current subsystem */
 	struct spdk_json_val *subsystems; /* "subsystems" array */
@@ -189,6 +190,9 @@ rpc_client_poller(void *arg)
 
 	if (resp->error) {
 		SPDK_ERRLOG("error response: %*s", (int)resp->error->len, (char *)resp->error->start);
+	}
+
+	if (resp->error && ctx->stop_on_error) {
 		spdk_jsonrpc_client_free_response(resp);
 		spdk_app_json_config_load_done(ctx, -EINVAL);
 	} else {
@@ -302,8 +306,7 @@ static void
 spdk_app_json_config_load_subsystem_config_entry_next(struct load_json_config_ctx *ctx,
 		struct spdk_jsonrpc_client_response *resp)
 {
-	/* Don't care about the response as long it is not
+	/* Don't care about the response */
-	 * an error (which is validated by poller) */
 	spdk_jsonrpc_client_free_response(resp);
 
 	ctx->config_it = spdk_json_next(ctx->config_it);
@@ -530,7 +533,8 @@ err:
 
 void
 spdk_app_json_config_load(const char *json_config_file, const char *rpc_addr,
-			  spdk_subsystem_init_fn cb_fn, void *cb_arg)
+			  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;
@@ -543,6 +547,7 @@ spdk_app_json_config_load(const char *json_config_file, const char *rpc_addr,
 
 	ctx->cb_fn = cb_fn;
 	ctx->cb_arg = cb_arg;
+	ctx->stop_on_error = stop_on_error;
 	ctx->thread = spdk_get_thread();
 
 	rc = spdk_app_json_config_read(json_config_file, ctx);

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

@@ -49,7 +49,7 @@ DEFINE_STUB_V(spdk_rpc_register_alias_deprecated, (const char *method, const cha
 DEFINE_STUB_V(spdk_rpc_set_state, (uint32_t state));
 DEFINE_STUB(spdk_rpc_get_state, uint32_t, (void), SPDK_RPC_RUNTIME);
 DEFINE_STUB_V(spdk_app_json_config_load, (const char *json_config_file, const char *rpc_addr,
-		spdk_subsystem_init_fn cb_fn, void *cb_arg));
+		spdk_subsystem_init_fn cb_fn, void *cb_arg, bool stop_on_error));
 
 static void
 unittest_usage(void)