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/device.c

@@ -40,6 +40,7 @@ struct device *device_new(struct subtype *st, const char *id)
 
 	dev->active.settings = setting_list_new();
 	dev->persistent.settings = setting_list_new();
+	dev->autoconf.settings = setting_list_new();
 
 	return dev;
 }
@@ -53,6 +54,7 @@ void device_free(struct device *dev)
 	free(dev->devid);
 	setting_list_free(dev->active.settings);
 	setting_list_free(dev->persistent.settings);
+	setting_list_free(dev->autoconf.settings);
 	free(dev);
 }
 
@@ -83,6 +85,15 @@ void device_print(struct device *dev, int level)
 		setting_list_print(dev->persistent.settings, level + 8);
 	else
 		printf("%*s<none>\n", level + 8, "");
+
+	printf("%*sautoconf:\n", level + 4, "");
+	printf("%*sexists=%d mod=%d deconf=%d\n",
+	       level + 8, "", dev->autoconf.exists, dev->autoconf.modified,
+	       dev->autoconf.deconfigured);
+	if (dev->autoconf.settings)
+		setting_list_print(dev->autoconf.settings, level + 8);
+	else
+		printf("%*s<none>\n", level + 8, "");
 }
 
 static const void *device_hash_get_id(void *dev_ptr)
@@ -182,6 +193,10 @@ bool device_needs_writing(struct device *dev, config_t config)
 	    (dev->persistent.modified || dev->persistent.deconfigured ||
 	     setting_list_modified(dev->persistent.settings)))
 		return true;
+	if (SCOPE_AUTOCONF(config) &&
+	    (dev->autoconf.modified || dev->autoconf.deconfigured ||
+	     setting_list_modified(dev->autoconf.settings)))
+		return true;
 
 	return false;
 }
@@ -204,6 +219,8 @@ static exit_code_t apply_setting(struct device *dev, config_t config,
 		/* Check for activeonly. */
 		if (!force && SCOPE_PERSISTENT(config) && a->activeonly)
 			goto err_activeonly_forceable;
+		if (!force && SCOPE_AUTOCONF(config) && a->activeonly)
+			goto err_activeonly_forceable;
 		/* Check for multiple values. */
 		if (!force && !a->multi && strlist_find(processed, key))
 			goto err_multi_forceable;
@@ -231,8 +248,15 @@ static exit_code_t apply_setting(struct device *dev, config_t config,
 					     a, key, value);
 	}
 
+	/* Apply to autoconf config. */
+	if (SCOPE_AUTOCONF(config)) {
+		setting_list_apply_specified(dev->autoconf.settings,
+					     a, key, value);
+	}
+
 	/* Additional warning when trying to persist read-only setting. */
-	if (config == config_persistent) {
+	if (!SCOPE_ACTIVE(config) && (SCOPE_PERSISTENT(config) ||
+				      SCOPE_AUTOCONF(config))) {
 		s = setting_list_find(dev->active.settings, key);
 		if (s && s->readonly)
 			warn_readonly = true;
@@ -341,6 +365,8 @@ void device_reset(struct device *dev, config_t config)
 		reset_device_state(&dev->active);
 	if (SCOPE_PERSISTENT(config))
 		reset_device_state(&dev->persistent);
+	if (SCOPE_AUTOCONF(config))
+		reset_device_state(&dev->autoconf);
 	dev->processed = 0;
 }
 
@@ -567,6 +593,12 @@ exit_code_t device_check_settings(struct device *dev, config_t config,
 						 err))
 			return EXIT_INVALID_CONFIG;
 	}
+	if (SCOPE_AUTOCONF(config)) {
+		if (!setting_list_check_conflict(dev->autoconf.settings,
+						 config_autoconf,
+						 err))
+			return EXIT_INVALID_CONFIG;
+	}
 
 	return EXIT_OK;
 }
@@ -578,8 +610,27 @@ struct setting_list *device_get_setting_list(struct device *dev,
 
 	if (config == config_active)
 		settings = dev->active.settings;
-	else
+	else if (config == config_persistent)
 		settings = dev->persistent.settings;
+	else if (config == config_autoconf)
+		settings = dev->autoconf.settings;
 
 	return settings;
 }
+
+/* Return configuration set in which device exists. */
+config_t device_get_config(struct device *dev)
+{
+	config_t config = 0;
+
+	if (dev->active.exists || dev->active.definable)
+		config |= config_active;
+
+	if (dev->persistent.exists)
+		config |= config_persistent;
+
+	if (dev->autoconf.exists)
+		config |= config_autoconf;
+
+	return config;
+}