Use persistent discovery controller by default

fabrics.c

@@ -58,6 +58,14 @@
 
 #define NVMF_DEF_DISC_TMO	30
 
+#if DEFAULT_EPCSD_ENABLED
+#define EPCSD_DISABLED_DEFAULT_STR
+#define EPCSD_ENABLED_DEFAULT_STR " (default)"
+#else
+#define EPCSD_ENABLED_DEFAULT_STR
+#define EPCSD_DISABLED_DEFAULT_STR " (default)"
+#endif
+
 /* Name of file to output log pages in their raw format */
 static char *raw;
 static bool persistent;
@@ -197,6 +205,7 @@ static int setup_common_context(struct libnvmf_context *fctx,
 
 struct hook_fabrics_data {
 	struct nvmf_args *fa;
+	struct libnvme_global_ctx *ctx;
 	nvme_print_flags_t flags;
 	bool quiet;
 	char *raw;
@@ -322,13 +331,17 @@ static int set_fabrics_options(struct libnvmf_context *fctx,
 static int hook_parser_next_line(struct libnvmf_context *fctx, void *user_data)
 {
 	struct hook_fabrics_data *hfd = user_data;
+	bool epcsd_enabled = false, epcsd_disabled = false;
+	struct libnvme_host *h = NULL;
 	struct nvmf_args fa;
 	char *ptr, *p;
 	static char line[4096];
 	int argc, ret = 0;
 	bool force = false;
 
 	NVMF_ARGS(opts, fa,
+		  OPT_FLAG("epcsd",          0, &epcsd_enabled,       "Enable persistent discovery for controllers that support it"),
+		  OPT_FLAG("no-epcsd",       0, &epcsd_disabled,      "Disable persistent discovery for controllers that support it"),
 		  OPT_FLAG("persistent",   'p', &persistent, "persistent discovery connection"),
 		  OPT_FLAG("force",          0, &force,      "Force persistent discovery controller creation"));
 
@@ -349,6 +362,11 @@ static int hook_parser_next_line(struct libnvmf_context *fctx, void *user_data)
 		fa.subsysnqn = NVME_DISC_SUBSYS_NAME;
 		if (argconfig_parse(argc, hfd->argv, "config", opts))
 			continue;
+
+		if (epcsd_enabled && epcsd_disabled) {
+			fprintf(stderr, "--epcsd and --no-epcsd are mutually exclusive\n");
+			continue;
+		}
 	} while (!fa.transport && !fa.traddr);
 
 	if (!fa.trsvcid)
@@ -361,6 +379,13 @@ static int hook_parser_next_line(struct libnvmf_context *fctx, void *user_data)
 	libnvmf_context_set_discovery_hooks(fctx, hook_discovery_log,
 		hook_parser_init, hook_parser_cleanup, hook_parser_next_line);
 
+	libnvme_get_host(hfd->ctx, fa.hostnqn, fa.hostid, &h);
+	if (epcsd_enabled)
+		libnvme_host_set_epcsd_enabled(h, true);
+
+	if (epcsd_disabled)
+		libnvme_host_set_epcsd_enabled(h, false);
+
 	return 0;
 }
 
@@ -557,13 +582,17 @@ int fabrics_discovery(const char *desc, int argc, char **argv, bool connect)
 	char *device = NULL;
 	bool force = false;
 	bool json_config = false;
+	bool epcsd_enabled = false, epcsd_disabled = false;
 	bool nbft = false, nonbft = false;
 	char *nbft_path = NBFT_SYSFS_PATH;
 	char *owner = NULL;
+	struct libnvme_host *h = NULL;
 
 	NVMF_ARGS(opts, fa,
 		  OPT_STRING("device",     'd', "DEV", &device,       "use existing discovery controller device"),
 		  OPT_FILE("raw",          'r', &raw,                 "save raw output to file"),
+		  OPT_FLAG("epcsd",          0, &epcsd_enabled,       "Enable persistent discovery for controllers that support it." EPCSD_ENABLED_DEFAULT_STR),
+		  OPT_FLAG("no-epcsd",       0, &epcsd_disabled,      "Disable persistent discovery for controllers that support it." EPCSD_DISABLED_DEFAULT_STR),
 		  OPT_FLAG("persistent",   'p', &persistent,          "persistent discovery connection"),
 		  OPT_FLAG("quiet",          0, &quiet,               "suppress already connected errors"),
 		  OPT_STRING("config",     'J', "FILE", &config_file, nvmf_config_file),
@@ -588,6 +617,11 @@ int fabrics_discovery(const char *desc, int argc, char **argv, bool connect)
 		return ret;
 	}
 
+	if (epcsd_enabled && epcsd_disabled) {
+		fprintf(stderr, "--epcsd and --no-epcsd options are mutually exclusive\n");
+		return -EINVAL;
+	}
+
 	if (!strcmp(config_file, "none"))
 		config_file = NULL;
 
@@ -637,6 +671,7 @@ int fabrics_discovery(const char *desc, int argc, char **argv, bool connect)
 
 	struct hook_fabrics_data dld = {
 		.fa = &fa,
+		.ctx = ctx,
 		.flags = flags,
 		.raw = raw,
 	};
@@ -662,6 +697,12 @@ int fabrics_discovery(const char *desc, int argc, char **argv, bool connect)
 		goto out_free;
 	}
 
+	libnvme_get_host(ctx, fa.hostnqn, fa.hostid, &h);
+	if (epcsd_enabled)
+		libnvme_host_set_epcsd_enabled(h, true);
+
+	if (epcsd_disabled)
+		libnvme_host_set_epcsd_enabled(h, false);
 	ret = libnvmf_discovery(ctx, fctx, connect, force);
 
 out_free:

libnvme/doc/config-schema.json

@@ -41,6 +41,10 @@
 			"description": "Enable/disable Persistent Discovery Controller",
 			"type": "boolean"
 		},
+		"supported_persistent_discovery_ctrl": {
+			"description": "Enable/disable persistent discovery for controllers that support it.",
+			"type": "boolean"
+		},
 		"subsystems": {
 		    "description": "Array of NVMe subsystem properties",
 		    "type": "array",

libnvme/doc/config-schema.json.in

@@ -41,6 +41,10 @@
 			"description": "Enable/disable Persistent Discovery Controller",
 			"type": "boolean"
 		},
+		"supported_persistent_discovery_ctrl": {
+			"description": "Enable/disable persistent discovery for controllers that support it.",
+			"type": "boolean"
+		},
 		"subsystems": {
 		    "description": "Array of NVMe subsystem properties",
 		    "type": "array",

libnvme/libnvme/accessors.i

@@ -189,8 +189,10 @@ Subsystem.__setattr__ = _nvme_guarded_setattr
 /* struct libnvme_host */
 %rename(Host) libnvme_host;
 %rename(libnvme_host_pdc_enabled_set) libnvme_host_set_pdc_enabled;
+%rename(libnvme_host_epcsd_enabled_set) libnvme_host_set_epcsd_enabled;
 %{
 	#define libnvme_host_pdc_enabled_set libnvme_host_set_pdc_enabled
+	#define libnvme_host_epcsd_enabled_set libnvme_host_set_epcsd_enabled
 %}
 struct libnvme_host {
 	%immutable hostnqn;

libnvme/src/libnvme.ld

@@ -64,8 +64,10 @@ LIBNVME_3 {
 		libnvme_get_uuid_list;
 		libnvme_get_version;
 		libnvme_host_get_global_ctx;
+		libnvme_host_is_epcsd_enabled;
 		libnvme_host_is_pdc_enabled;
 		libnvme_host_release_fds;
+		libnvme_host_set_epcsd_enabled;
 		libnvme_host_set_pdc_enabled;
 		libnvme_init_ctrl;
 		libnvme_namespace_first_path;

libnvme/src/nvme/fabrics.c

@@ -2351,6 +2351,20 @@ static int _nvmf_discovery(struct libnvme_global_ctx *ctx,
 	}
 
 	numrec = le64_to_cpu(log->numrec);
+
+	for (int i = 0; i < numrec; i++) {
+		struct nvmf_disc_log_entry *e = &log->entries[i];
+		uint16_t eflags = le16_to_cpu(e->eflags);
+
+		if ((e->subtype == NVME_NQN_DISC ||
+		    e->subtype == NVME_NQN_CURR) &&
+		    (eflags & NVMF_DISC_EFLAGS_EPCSD) &&
+		    libnvme_host_is_epcsd_enabled(h, DEFAULT_EPCSD_ENABLED)) {
+			libnvmf_context_set_persistent(fctx, true);
+			break;
+		}
+	}
+
 	if (fctx->hooks.discovery_log)
 		fctx->hooks.discovery_log(fctx, connect, log, numrec,
 			fctx->hooks.user_data);

libnvme/src/nvme/json.c

@@ -175,6 +175,9 @@ static void json_parse_host(struct libnvme_global_ctx *ctx, struct json_object *
 	attr_obj = json_object_object_get(host_obj, "persistent_discovery_ctrl");
 	if (attr_obj)
 		libnvme_host_set_pdc_enabled(h, json_object_get_boolean(attr_obj));
+	attr_obj = json_object_object_get(host_obj, "supported_persistent_discovery_ctrl");
+	if (attr_obj)
+		libnvme_host_set_epcsd_enabled(h, json_object_get_boolean(attr_obj));
 	subsys_array = json_object_object_get(host_obj, "subsystems");
 	if (!subsys_array)
 		return;
@@ -437,6 +440,9 @@ int json_update_config(struct libnvme_global_ctx *ctx, int fd)
 		if (h->pdc_enabled_valid)
 			json_object_object_add(host_obj, "persistent_discovery_ctrl",
 					       json_object_new_boolean(h->pdc_enabled));
+		if (h->epcsd_enabled_valid)
+			json_object_object_add(host_obj, "supported_persistent_discovery_ctrl",
+					       json_object_new_boolean(h->epcsd_enabled));
 		subsys_array = json_object_new_array();
 		libnvme_for_each_subsystem(h, s) {
 			json_update_subsys(subsys_array, s);
@@ -664,6 +670,9 @@ int json_dump_tree(struct libnvme_global_ctx *ctx)
 		if (h->pdc_enabled_valid)
 			json_object_object_add(host_obj, "persistent_discovery_ctrl",
 					       json_object_new_boolean(h->pdc_enabled));
+		if (h->epcsd_enabled_valid)
+			json_object_object_add(host_obj, "supported_persistent_discovery_ctrl",
+					       json_object_new_boolean(h->epcsd_enabled));
 		subsys_array = json_object_new_array();
 		libnvme_for_each_subsystem(h, s) {
 			json_dump_subsys(subsys_array, s);

libnvme/src/nvme/private.h

@@ -395,6 +395,13 @@ struct libnvme_host {  // !generate-accessors:read=generated,write=none !generat
 	 */
 	bool pdc_enabled;		// !access:read=none,write=custom
 	bool pdc_enabled_valid;		// !access:read=none
+
+	/* epcsd_enabled and epcsd_enabled_valid work together. epcsd_enabled_valid,
+	 * when true, indicates that epcsd_enabled has been explicitly defined.
+	 * epcsd_enabled_valid is internal meta-data for epcsd_enabled.
+	 */
+	bool epcsd_enabled;		// !access:read=none,write=custom
+	bool epcsd_enabled_valid;	// !access:read=none
 };
 
 struct libnvme_fabric_options { // !generate-accessors

libnvme/src/nvme/tree.c

@@ -225,6 +225,21 @@ __libnvme_public struct libnvme_global_ctx *libnvme_host_get_global_ctx(
 	return h->ctx;
 }
 
+__libnvme_public void libnvme_host_set_epcsd_enabled(
+		libnvme_host_t h, bool enabled)
+{
+	h->epcsd_enabled_valid = true;
+	h->epcsd_enabled = enabled;
+}
+
+__libnvme_public bool libnvme_host_is_epcsd_enabled(
+		libnvme_host_t h, bool fallback)
+{
+	if (h->epcsd_enabled_valid)
+		return h->epcsd_enabled;
+	return fallback;
+}
+
 __libnvme_public void libnvme_host_set_pdc_enabled(
 		libnvme_host_t h, bool enabled)
 {

libnvme/src/nvme/tree.h

@@ -76,6 +76,28 @@ libnvme_host_t libnvme_next_host(struct libnvme_global_ctx *ctx,
  */
 struct libnvme_global_ctx *libnvme_host_get_global_ctx(libnvme_host_t h);
 
+/**
+ * libnvme_host_set_epcsd_enabled() - Set Explicit Persistent Discovery Controller flag
+ * @h:		Host for which the falg should be set
+ * @enabled:	The bool to set the enabled flag
+ *
+ * When libnvme_host_set_epcsd_enabled() is not used to set the PDC flag,
+ * libnvme_host_is_epcsd_enabled() will return the default value which was
+ * passed into the function and not the undefined flag value.
+ */
+void libnvme_host_set_epcsd_enabled(libnvme_host_t h, bool enabled);
+
+/**
+ * libnvme_host_is_epcsd_enabled() - Is Persistenct Discovery Controller enabled
+ * @h: 		Host which to check if PDC is enabled
+ * @fallback:	The fallback default value of the flag when
+ * 		@libnvme_host_set_epcsd_enabled has not be used
+ * 		to set the flag.
+ *
+ * Return: true if PDC is enabled for @h, else false
+ */
+bool libnvme_host_is_epcsd_enabled(libnvme_host_t h, bool fallback);
+
 /**
  * libnvme_host_set_pdc_enabled() - Set Persistent Discovery Controller flag
  * @h:		Host for which the falg should be set

meson.build

@@ -182,6 +182,8 @@ conf.set('NVME_VERSION', '"@0@"'.format(meson.project_version()))
 conf.set('LIBNVME_VERSION', '"@0@"'.format(meson.project_version()))
 
 conf.set10('DEFAULT_PDC_ENABLED', get_option('pdc-enabled'))
+conf.set10('DEFAULT_EPCSD_ENABLED', get_option('default-epcsd-enabled'))
+
 
 # local (cross-compilable) implementations of ccan configure steps
 conf.set10(

meson_options.txt

@@ -95,6 +95,12 @@ option(
   value : false,
   description : 'set default Persistent Discovery Controllers behavior'
 )
+option(
+  'default-epcsd-enabled',
+  type: 'boolean',
+  value : true,
+  description : 'by default set Supported Persistent Discovery Controllers to be persistent'
+)
 option(
   'rundir',
   type: 'string',