zdev: Add support for handling auto-configuration data

Auto-configuration is the name of a new configuration target that is
supported by chzdev and lszdev besides the existing active and
persistent configuration targets. Directives created in this new
configuration are stored as udev rules in the /run/udev/rules.d
directory.

Auto-configuration directives are only in effect if there are no
directives for the same device in the user-provided persistent
configuration. This allows users to override auto-configuration
directives if necessary.

Due to the volatile nature of the /run directory, auto-configuration
directives are cleared on reboot. Therefore mechanisms that generate
auto-configuration directives must recreate them on every boot.

The lszdev tool displays auto-configuration data both in list view
as well as in detail view. Users can specify the new option --auto-conf
to only show data from this configuration target.

Mechanisms that generate automated configuration directives can use
chzdev together with the --auto-conf option to create the corresponding
udev rules.

Note: This change does not include a mechanism that generates
      auto-configuration directives.

Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>

zdev/src/chzdev.c

@@ -86,6 +86,7 @@ struct options {
 	config_t config;
 	unsigned int active:1;
 	unsigned int persistent:1;
+	unsigned int auto_conf:1;
 	struct util_list *remove;	/* List of struct strlist_node */
 	unsigned int remove_all:1;
 	unsigned int force:1;
@@ -138,6 +139,7 @@ enum {
 	OPT_VERBOSE		= 'V',
 	OPT_QUIET		= 'q',
 	OPT_NO_SETTLE		= (OPT_ANONYMOUS_BASE+__COUNTER__),
+	OPT_AUTO_CONF		= (OPT_ANONYMOUS_BASE+__COUNTER__),
 };
 
 static struct opts_conflict conflict_list[] = {
@@ -172,11 +174,13 @@ static struct opts_conflict conflict_list[] = {
 	OPTS_CONFLICT(OPT_APPLY,
 		      OPT_DECONFIGURE, OPT_LIST_ATTRIBS, OPT_HELP_ATTRIBS,
 		      OPT_LIST_TYPES, OPT_EXPORT, OPT_IMPORT, OPT_REMOVE,
-		      OPT_REMOVE_ALL, OPT_ACTIVE, OPT_PERSISTENT, 0),
+		      OPT_REMOVE_ALL, OPT_ACTIVE, 0),
 	OPTS_CONFLICT(OPT_ONLINE,
 		      OPT_OFFLINE),
 	OPTS_CONFLICT(OPT_QUIET,
 		      OPT_VERBOSE),
+	OPTS_CONFLICT(OPT_AUTO_CONF,
+		      OPT_TYPE, OPT_LIST_ATTRIBS, OPT_LIST_TYPES),
 	OPTS_CONFLICT(0, 0),
 };
 
@@ -210,6 +214,7 @@ static const struct option opt_list[] = {
 	/* Options. */
 	{ "active",		no_argument,	NULL, OPT_ACTIVE },
 	{ "persistent",		no_argument,	NULL, OPT_PERSISTENT },
+	{ "auto-conf",		no_argument,	NULL, OPT_AUTO_CONF },
 	{ "remove",		required_argument, NULL, OPT_REMOVE },
 	{ "remove-all",		no_argument,	NULL, OPT_REMOVE_ALL },
 	{ "force",		no_argument,	NULL, OPT_FORCE },
@@ -883,6 +888,11 @@ static exit_code_t parse_options(struct options *opts, int argc, char *argv[])
 			opts->persistent = 1;
 			break;
 
+		case OPT_AUTO_CONF:
+			/* --auto-conf */
+			opts->auto_conf = 1;
+			break;
+
 		case OPT_REMOVE:
 			/* --remove ATTRIB */
 			strlist_add(opts->remove, "%s", optarg);
@@ -977,7 +987,13 @@ static exit_code_t parse_options(struct options *opts, int argc, char *argv[])
 		goto out;
 
 	/* Determine configuration set. */
-	opts->config = get_config(opts->active, opts->persistent);
+	if (!opts->active && !opts->persistent && !opts->auto_conf) {
+		/* Default configuration targets are active + persistent */
+		opts->config = config_active | config_persistent;
+	} else {
+		opts->config = get_config(opts->active, opts->persistent,
+					  opts->auto_conf);
+	}
 
 	/* Handle positional parameters. */
 	rc = parse_positional(opts, argc, argv, optind);
@@ -1049,13 +1065,15 @@ static void remove_all_settings(struct setting_list *settings, int active)
 /* Perform --remove-all operation for specified config on device. */
 static exit_code_t device_remove_all(struct device *dev, config_t config)
 {
-	int active, persistent;
+	int active, persistent, autoconf;
 
 	active = SCOPE_ACTIVE(config) ?
 			count_removable(dev->active.settings, 1) : 0;
 	persistent = SCOPE_PERSISTENT(config) ?
 			count_removable(dev->persistent.settings, 0) : 0;
-	if (active == 0 && persistent == 0) {
+	autoconf = SCOPE_AUTOCONF(config) ?
+			count_removable(dev->autoconf.settings, 0) : 0;
+	if (active == 0 && persistent == 0 && autoconf == 0) {
 		delayed_err("No removable settings found\n");
 		return EXIT_SETTING_NOT_FOUND;
 	}
@@ -1063,6 +1081,8 @@ static exit_code_t device_remove_all(struct device *dev, config_t config)
 		remove_all_settings(dev->active.settings, 1);
 	if (persistent)
 		remove_all_settings(dev->persistent.settings, 0);
+	if (autoconf)
+		remove_all_settings(dev->autoconf.settings, 0);
 
 	return EXIT_OK;
 }
@@ -1132,6 +1152,13 @@ static exit_code_t device_remove_settings(struct device *dev,
 			goto out;
 	}
 
+	if (SCOPE_AUTOCONF(config)) {
+		rc = remove_settings(dev->autoconf.settings, names, found,
+				     notfound, 0);
+		if (rc)
+			goto out;
+	}
+
 	if (!util_list_is_empty(notfound)) {
 		flat = strlist_flatten(notfound, " ");
 		delayed_err("Setting not found: %s\n", flat);
@@ -1199,7 +1226,8 @@ static void print_dev_config_info(struct device *dev, config_t config)
 
 	changes = setting_get_changes(
 		  SCOPE_ACTIVE(config) ? dev->active.settings : NULL,
-		  SCOPE_PERSISTENT(config) ? dev->persistent.settings : NULL);
+		  SCOPE_PERSISTENT(config) ? dev->persistent.settings : NULL,
+		  SCOPE_AUTOCONF(config) ? dev->autoconf.settings : NULL);
 	if (changes)
 		info("    Changes: %s\n", changes);
 	free(changes);
@@ -1257,6 +1285,12 @@ static exit_code_t cfg_mod_existence(struct device *dev, config_t config)
 		dev->persistent.modified = 1;
 	}
 
+	/* Create autoconf config if necessary. */
+	if (SCOPE_AUTOCONF(config) && !dev->autoconf.exists) {
+		dev->autoconf.exists = 1;
+		dev->autoconf.modified = 1;
+	}
+
 	return EXIT_OK;
 }
 
@@ -1296,11 +1330,14 @@ online:
 	/* Make sure there's an online attribute. */
 	ensure_online(dev, config_active);
 	ensure_online(dev, config_persistent);
+	ensure_online(dev, config_autoconf);
 
 mand:
 	/* Ensure default values for mandatory attributes. */
 	setting_list_apply_defaults(dev->persistent.settings,
 				    dev->subtype->dev_attribs, true);
+	setting_list_apply_defaults(dev->autoconf.settings,
+				    dev->subtype->dev_attribs, true);
 
 	return EXIT_OK;
 }
@@ -1336,7 +1373,8 @@ static exit_code_t cfg_write(struct device *dev, int prereq, config_t config,
 	if (!device_needs_writing(dev, config) && !force)
 		goto out;
 
-	if (check_active && config == config_persistent &&
+	if (check_active && !SCOPE_ACTIVE(config) &&
+	    (SCOPE_PERSISTENT(config) || SCOPE_AUTOCONF(config)) &&
 	    (!dev->active.exists && !dev->active.definable)) {
 		rc = handle_nonexistent(dev);
 		if (rc)
@@ -1377,7 +1415,7 @@ static exit_code_t cfg_configure(struct subtype *st, const char *id,
 	if (proc_ptr)
 		*proc_ptr = 0;
 
-	/* Read current device data. Note that we read data from both
+	/* Read current device data. Note that we read data from all
 	 * configurations to enable QETH autodetection and subtype
 	 * detection (e.g. dasd -> dasd_fba).*/
 	dev = NULL;
@@ -1398,23 +1436,17 @@ static exit_code_t cfg_configure(struct subtype *st, const char *id,
 
 	/* Exit here if we're only trying and device cannot be configured. */
 	if (try && !(dev->active.exists || dev->active.definable ||
-		     dev->persistent.exists)) {
+		     dev->persistent.exists || dev->autoconf.exists)) {
 		return EXIT_DEVICE_NOT_FOUND;
 	}
 
-	if (config == config_persistent) {
-		/* Abort if a modification action is triggered for a
-		 * non-existing persistent device. */
-		if (!dev->persistent.exists &&
-		    (!util_list_is_empty(opts->remove) || opts->remove_all))
-			return EXIT_DEVICE_NOT_FOUND;
+	/* Create device if needed by action. */
+	if (opts->enable || !util_list_is_empty(opts->settings)) {
+		rc = cfg_mod_existence(dev, config);
+		if (rc)
+			return rc;
 	}
 
-	/* Apply changes to device existence. */
-	rc = cfg_mod_existence(dev, config);
-	if (rc)
-		return rc;
-
 	/* Apply changes to device settings. */
 	rc = cfg_mod_settings(dev, opts, prereq);
 	if (rc)
@@ -1426,10 +1458,12 @@ static exit_code_t cfg_configure(struct subtype *st, const char *id,
 
 /* Apply persistent configuration to active configuration. */
 static exit_code_t cfg_apply(struct subtype *st, const char *id, int prereq,
-			     struct device **dev_ptr, int *proc_ptr)
+			     struct device **dev_ptr, int *proc_ptr,
+			     bool autoconf)
 {
 	exit_code_t rc;
 	struct device *dev;
+	struct device_state *state;
 
 	/* Reset processed flag. */
 	if (proc_ptr)
@@ -1452,8 +1486,9 @@ static exit_code_t cfg_apply(struct subtype *st, const char *id, int prereq,
 		*proc_ptr = 1;
 	dev->processed = 1;
 
+	state = autoconf ? &dev->autoconf : &dev->persistent;
 	/* Exit here if there is no persistent configuration. */
-	if (!dev->persistent.exists)
+	if (!state->exists)
 		return EXIT_NO_DATA;
 
 	/* Apply changes to device existence. */
@@ -1462,8 +1497,7 @@ static exit_code_t cfg_apply(struct subtype *st, const char *id, int prereq,
 		return rc;
 
 	/* Copy persistent settings to active configuration. */
-	rc = device_apply_settings(dev, config_active,
-				   &dev->persistent.settings->list);
+	rc = device_apply_settings(dev, config_active, &state->settings->list);
 	if (rc)
 		return rc;
 
@@ -1477,7 +1511,8 @@ static exit_code_t cfg_import(struct subtype *st, const char *id,
 			      struct device **dev_ptr, int *proc_ptr)
 {
 	exit_code_t rc;
-	struct setting_list *active = NULL, *persistent = NULL;
+	struct setting_list *active = NULL, *persistent = NULL,
+			    *autoconf = NULL;
 	struct device *dev;
 
 	/* Reset processed flag. */
@@ -1495,6 +1530,7 @@ static exit_code_t cfg_import(struct subtype *st, const char *id,
 			return EXIT_OK;
 		active = setting_list_copy(dev->active.settings);
 		persistent = setting_list_copy(dev->persistent.settings);
+		autoconf = setting_list_copy(dev->autoconf.settings);
 	} else if (!prereq) {
 		/* Should not happen. */
 		return EXIT_OK;
@@ -1524,14 +1560,20 @@ static exit_code_t cfg_import(struct subtype *st, const char *id,
 					   &persistent->list);
 		if (rc)
 			goto out;
+		rc = device_apply_settings(dev, config_autoconf,
+					   &autoconf->list);
+		if (rc)
+			goto out;
 	}
 	ensure_online(dev, config_active);
 	ensure_online(dev, config_persistent);
+	ensure_online(dev, config_autoconf);
 
 	/* Write resulting device data. */
 	rc = cfg_write(dev, prereq, config, 0);
 
 out:
+	setting_list_free(autoconf);
 	setting_list_free(persistent);
 	setting_list_free(active);
 
@@ -1609,11 +1651,13 @@ static exit_code_t print_config_result(struct selected_dev_node *sel,
 	if (opts->deconfigure) {
 		op = "deconfigure";
 		verb = "deconfigured";
-		if (dev)
+		if (dev) {
 			already = !dev->active.modified &&
-				  !dev->persistent.modified;
-		else if (rc == EXIT_DEVICE_NOT_FOUND &&
-			 config == config_persistent) {
+				  !dev->persistent.modified &&
+				  !dev->autoconf.modified;
+		} else if (rc == EXIT_DEVICE_NOT_FOUND &&
+			 (!SCOPE_ACTIVE(config) && (SCOPE_PERSISTENT(config) ||
+			  SCOPE_AUTOCONF(config)))) {
 			rc = EXIT_OK;
 			already = 1;
 		}
@@ -1685,9 +1729,10 @@ static exit_code_t cfg_prereqs(struct subtype *st, const char *id,
 	prereqs = selected_dev_list_new();
 	subtype_add_prereqs(st, id, prereqs);
 	util_list_iterate(prereqs, sel) {
-		if (opts->apply)
-			rc = cfg_apply(sel->st, sel->id, 1, &dev, &proc);
-		else if (opts->import) {
+		if (opts->apply) {
+			rc = cfg_apply(sel->st, sel->id, 1, &dev, &proc,
+				       opts->auto_conf);
+		} else if (opts->import) {
 			rc = cfg_import(sel->st, sel->id, config, 1, &dev,
 					&proc);
 		} else {
@@ -1760,9 +1805,11 @@ static exit_code_t configure_devices(struct options *opts, int specified,
 	struct namespace *ns;
 	const char *param;
 	struct device *dev;
+	config_t config = opts->config;
 
 	/* Determine list of selected devices. */
-	if (opts->config == config_persistent ||
+	if ((!SCOPE_ACTIVE(config) &&
+	    (SCOPE_PERSISTENT(config) || SCOPE_AUTOCONF(config))) ||
 	    (opts->select->subtype && opts->select->subtype->support_definable))
 		existing = 0;
 	else
@@ -1808,9 +1855,10 @@ static exit_code_t configure_devices(struct options *opts, int specified,
 			goto next;
 
 		/* Configure actual target device. */
-		if (opts->apply)
-			rc = cfg_apply(sel->st, sel->id, 0, &dev, &proc);
-		else {
+		if (opts->apply) {
+			rc = cfg_apply(sel->st, sel->id, 0, &dev, &proc,
+				       opts->auto_conf);
+		} else {
 			rc = cfg_configure(sel->st, sel->id, opts, 0,
 					   0, &dev, &proc);
 		}
@@ -1906,7 +1954,7 @@ static exit_code_t deconfigure_one_device(struct subtype *st, const char *id,
 	dev->processed = 1;
 
 	if (try && !(dev->active.exists || dev->active.definable ||
-		     dev->persistent.exists)) {
+		     dev->persistent.exists || dev->autoconf.exists)) {
 		/* Attempt to deconfigure this device will fail. */
 		return EXIT_DEVICE_NOT_FOUND;
 	}
@@ -1916,7 +1964,8 @@ static exit_code_t deconfigure_one_device(struct subtype *st, const char *id,
 	 * dev. */
 	if (SCOPE_ACTIVE(config) &&
 	    !(dev->active.exists || dev->active.definable)) {
-		if (!SCOPE_PERSISTENT(config) || !dev->persistent.exists)
+		if (!((SCOPE_PERSISTENT(config) && dev->persistent.exists) ||
+		      (SCOPE_AUTOCONF(config) && dev->autoconf.exists)))
 			return EXIT_DEVICE_NOT_FOUND;
 	}
 
@@ -1940,7 +1989,12 @@ static exit_code_t deconfigure_one_device(struct subtype *st, const char *id,
 		dev->persistent.deconfigured = 1;
 		dev->persistent.modified = 1;
 	}
-	if (!dev->active.modified && !dev->persistent.modified)
+	if (SCOPE_AUTOCONF(config) && dev->autoconf.exists) {
+		dev->autoconf.deconfigured = 1;
+		dev->autoconf.modified = 1;
+	}
+	if (!dev->active.modified && !dev->persistent.modified &&
+	    !dev->autoconf.modified)
 		return EXIT_OK;
 
 	/* Pre-write check. */
@@ -2084,7 +2138,8 @@ static void print_type_config_info(struct devtype *dt, const char *title,
 
 	changes = setting_get_changes(
 		  SCOPE_ACTIVE(config) ? dt->active_settings : NULL,
-		  SCOPE_PERSISTENT(config) ? dt->persistent_settings : NULL);
+		  SCOPE_PERSISTENT(config) ? dt->persistent_settings : NULL,
+		  NULL);
 	if (changes)
 		info("    %s: %s\n", title, changes);
 	free(changes);
@@ -2498,6 +2553,8 @@ static void action_note(const char *msg, config_t config)
 		info("%s the active configuration only\n", msg);
 	else if (config == config_persistent)
 		info("%s the persistent configuration only\n", msg);
+	else if (config == config_autoconf)
+		info("%s the auto-configuration only\n", msg);
 }
 
 /* Export configuration of selected devices and/or device type to file. */
@@ -2619,7 +2676,7 @@ static exit_code_t import_device(struct device *dev, struct options *opts)
 	struct subtype *st = dev->subtype;
 	exit_code_t rc;
 	config_t config;
-	int proc = 0, active, persistent;
+	int proc = 0, active, persistent, autoconf;
 
 	if (SCOPE_ACTIVE(opts->config))
 		active = (dev->active.exists || dev->active.definable);
@@ -2629,7 +2686,16 @@ static exit_code_t import_device(struct device *dev, struct options *opts)
 		persistent = dev->persistent.exists;
 	else
 		persistent = 0;
-	config = get_config(active, persistent);
+	if (SCOPE_AUTOCONF(opts->config))
+		autoconf = dev->autoconf.exists;
+	else
+		autoconf = 0;
+
+	if (!active && !persistent && !autoconf) {
+		/* Nothing to import */
+		return EXIT_OK;
+	}
+	config = get_config(active, persistent, autoconf);
 
 	/* First check for prerequisite devices that need to be configured. */
 	rc = cfg_prereqs(st, dev->id, opts, config, 0);
@@ -2656,17 +2722,9 @@ static bool import_device_selected(struct device *dev, struct options *opts)
 	if (!select_opts_dev_specified(select))
 		return false;
 
-	/* --active */
-	if (opts->config == config_active) {
-		if (!dev->active.exists && !dev->active.definable)
-			return false;
-	}
-
-	/* --persistent */
-	if (opts->config == config_persistent) {
-		if (!dev->persistent.exists)
-			return false;
-	}
+	/* Target configuration */
+	if ((device_get_config(dev) & opts->config) == 0)
+		return false;
 
 	/* Devtype */
 	if (select->devtype && dt != select->devtype)