zdev: make site specific udev-rule for ccw

The udev-rules must be modified to make it site-specific. The site
specific part of the rule should be executed only on the sites where the
devices belong. Change the generic udev rule to support the site-specific
udev-rule.

During boot, the current site-id is read from the LOADPARM which is
located at /sys/firmware/ipl. The zdev_id command reads this LOADPARM
and prints the SITE_ID based on the value. This SITE_ID is the
current site where the udev-rule is executing. Based on this assumption,
the rule is divided in to multiple blocks where each site block is executed
only for the corresponding sites.

The rule executes based on the value read from the LOADPARM.
1. When the LOADPARM specifies a site-id and if the current device has
   an associated configuration settings, it will be used.
2. When the LOADPARM specifies a site, and the current device does not
   have any associated configuration set, the udev rule uses the
   fallback configuration settings.
3. If the device does not have a fallback-configuration settings or any
   site-specific settings, no configurations will be used.

Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>

zdev/src/ccw.c

@@ -1593,7 +1593,7 @@ static exit_code_t ccw_st_deconfigure_active(struct subtype *st,
 static exit_code_t ccw_st_deconfigure_persistent(struct subtype *st,
 						 struct device *dev)
 {
-	return udev_remove_rule(st->name, dev->id, false);
+	return ccw_st_configure_persistent(st, dev);
 }
 
 /**

zdev/src/path.c

@@ -404,3 +404,13 @@ char *path_get_bus_attr(const char *bus, const char *attr)
 {
 	return path_get("/sys/bus/%s/%s", bus, attr);
 }
+
+ /* Return path will be with ZDEV_PREFIX oon PATH_UDEV_RULES */
+char *path_get_zdev_rule(const char *name)
+{
+	const char *path = PATH_UDEV_RULES;
+
+	/* Create file. */
+	return path_get("%s/%s-%s%s", path,
+			ZDEV_PREFIX, name, UDEV_SUFFIX);
+}

zdev/src/udev.c

@@ -23,6 +23,7 @@
 #include "path.h"
 #include "setting.h"
 #include "udev.h"
+#include "zdev_id.h"
 
 int udev_need_settle = 0;
 int udev_no_settle;
@@ -137,3 +138,61 @@ void udev_add_internal_from_entry(struct setting_list *list,
 out:
 	free(copy);
 }
+
+/*
+ * Write the UDEV rule that determines the active SITE_ID
+ */
+exit_code_t udev_write_site_rule(void)
+{
+	char *path, *name = "zdev-id";
+	exit_code_t rc = EXIT_OK;
+	FILE *fd;
+
+	/* Create file. */
+	path = path_get_zdev_rule(name);
+
+	if (!util_path_exists(path)) {
+		rc = path_create(path);
+		if (rc)
+			goto out;
+	}
+
+	fd = misc_fopen(path, "w");
+	if (!fd) {
+		error("Could not write to file %s: %s\n", path,
+		      strerror(errno));
+		rc = EXIT_RUNTIME_ERROR;
+		goto out;
+	}
+	fprintf(fd, "# Generated by chzdev\n");
+	fprintf(fd, "\n");
+	/* We have to make sure that we are not trying to determine the SITE_ID
+	 * for all the corresponding uevent. Check if the SITE_ID is already
+	 * determined by reading the file  /run/zdev_site_id; and if it is not
+	 * available, execute the zdev_id program and determine the SITE_ID and
+	 * create the new zdev_site_id file for next run.
+	 */
+	fprintf(fd, "TEST!=\"%s\", IMPORT{program}="
+			"\"%s/zdev_id\",GOTO=\"end\"\n", ZDEV_SITE_ID_FILE,
+			TOOLS_LIBDIR);
+	fprintf(fd, "IMPORT{file}=\"%s\"\n", ZDEV_SITE_ID_FILE);
+	fprintf(fd, "LABEL=\"end\"\n");
+
+	if (misc_fclose(fd))
+		warn("Could not close file %s: %s\n", path, strerror(errno));
+
+out:
+	free(path);
+	return rc;
+}
+
+bool is_legacy_rule(struct util_udev_file *file)
+{
+	struct util_udev_line_node *line;
+
+	util_list_iterate(&file->lines, line)
+		if (starts_with(line->line, SITE_BLOCK_START))
+			return false;
+
+	return true;
+}

zdev/src/udev_ccw.c

@@ -26,6 +26,8 @@
 #include "udev.h"
 #include "udev_ccw.h"
 
+#define SITE_FALLBACK_SUFFIX	"fb"
+
 /* Check if a udev rule for the specified ccw device exists. */
 bool udev_ccw_exists(const char *type, const char *id, bool autoconf)
 {
@@ -79,10 +81,68 @@ out:
 	free(copy);
 }
 
+static void get_site_from_line(char *line, int *site, bool *in_site)
+{
+	char site_str[2];
+
+	if (starts_with(line, SITE_BLOCK_START)) {
+		memcpy(site_str, line + sizeof(SITE_BLOCK_START), 2);
+		if (strcmp(site_str, "fb") != 0)
+			*site = atoi(site_str);
+		else
+			*site = SITE_FALLBACK;
+		*in_site = true;
+	} else if (starts_with(line, SITE_BLOCK_END)) {
+		memcpy(site_str, line + sizeof(SITE_BLOCK_END), 2);
+		if (strcmp(site_str, "fb") != 0)
+			*site = atoi(site_str);
+		else
+			*site = SITE_FALLBACK;
+		*in_site = false;
+	}
+}
+
+static void dev_state_copy(struct device_state *dst, struct device_state *src)
+{
+	setting_list_free(dst->settings);
+	dst->settings = setting_list_copy(src->settings);
+	dst->exists = src->exists;
+	dst->modified = src->modified;
+	dst->deconfigured = src->deconfigured;
+	dst->blacklisted = src->blacklisted;
+	dst->definable = src->definable;
+}
+
+/* Extract per-site CCW device settings from a CCW device udev rule file. */
+static void _udev_file_get_settings_new(struct util_udev_file *file,
+					struct attrib **attribs,
+					struct device *dev)
+{
+	struct util_udev_line_node *line;
+	struct util_udev_entry_node *entry;
+	int site_id = SITE_FALLBACK;
+	struct setting_list *list;
+	bool in_site = false;
+
+	util_list_iterate(&file->lines, line) {
+		get_site_from_line(line->line, &site_id, &in_site);
+		if (!in_site || site_id >= NUM_SITES || site_id < 0)
+			continue;
+		entry = util_list_start(&line->entries);
+		if (!entry)
+			continue;
+		list = dev->site_specific[site_id].settings;
+		add_setting_from_entry(list, entry, attribs);
+		dev->site_specific[site_id].exists = 1;
+		if (site_id == global_site_id)
+			dev_state_copy(&dev->persistent, &dev->site_specific[site_id]);
+	}
+}
+
 /* Extract CCW device settings from a CCW device udev rule file. */
-static void udev_file_get_settings(struct util_udev_file *file,
-				   struct attrib **attribs,
-				   struct setting_list *list)
+static void _udev_file_get_settings_legacy(struct util_udev_file *file,
+					   struct attrib **attribs,
+					   struct setting_list *list)
 {
 	struct util_udev_line_node *line;
 	struct util_udev_entry_node *entry;
@@ -95,6 +155,22 @@ static void udev_file_get_settings(struct util_udev_file *file,
 	}
 }
 
+static void udev_file_get_settings(struct util_udev_file *file,
+				   struct attrib **attribs,
+				   struct device *dev,
+				   bool autoconf)
+{
+	struct device_state *state = autoconf ? &dev->autoconf :
+		&dev->persistent;
+
+	if (is_legacy_rule(file) || autoconf) {
+		_udev_file_get_settings_legacy(file, attribs, state->settings);
+		state->exists = 1;
+	} else {
+		_udev_file_get_settings_new(file, attribs, dev);
+	}
+}
+
 /* Read the persistent configuration of a CCW device from a udev rule. */
 exit_code_t udev_ccw_read_device(struct device *dev, bool autoconf)
 {
@@ -113,8 +189,7 @@ exit_code_t udev_ccw_read_device(struct device *dev, bool autoconf)
 		warn_once("Warning: Invalid udev rule: %s\n", path);
 		state->exists = 0;
 	} else {
-		udev_file_get_settings(file, st->dev_attribs, state->settings);
-		state->exists = 1;
+		udev_file_get_settings(file, st->dev_attribs, dev, autoconf);
 	}
 	util_udev_free_file(file);
 
@@ -141,8 +216,32 @@ static char *get_label_id(const char *prefix, const char *type,
 	return id;
 }
 
-/* Write the persistent configuration of a CCW device to a udev rule. */
-exit_code_t udev_ccw_write_device(struct device *dev, bool autoconf)
+static void write_attr_to_file(FILE *fd, struct device_state *state, const char *id)
+{
+	struct ptrlist_node *p;
+	struct setting *s;
+	struct util_list *list = NULL;
+
+	/* Apply attributes in correct order. */
+	list = setting_list_get_sorted(state->settings);
+
+	util_list_iterate(list, p) {
+		s = p->ptr;
+		if (s->removed)
+			continue;
+		if ((s->attrib && s->attrib->internal) ||
+		    internal_by_name(s->name)) {
+			fprintf(fd, "ENV{zdev_%s}=\"%s\"\n",
+				internal_get_name(s->name), s->value);
+		} else {
+			fprintf(fd, "ATTR{[ccw/%s]%s}=\"%s\"\n", id, s->name,
+				s->value);
+		}
+	}
+	ptrlist_free(list, 0);
+}
+
+static exit_code_t udev_ccw_write_device_legacy(struct device *dev, bool autoconf)
 {
 	struct subtype *st = dev->subtype;
 	struct ccw_subtype_data *data = st->data;
@@ -150,22 +249,16 @@ exit_code_t udev_ccw_write_device(struct device *dev, bool autoconf)
 	struct device_state *state = autoconf ? &dev->autoconf :
 						&dev->persistent;
 	char *path, *cfg_label = NULL, *end_label = NULL;
-	struct util_list *list;
-	struct ptrlist_node *p;
-	struct setting *s;
 	exit_code_t rc = EXIT_OK;
 	FILE *fd;
 
 	if (!state->exists)
-		return udev_remove_rule(type, id, autoconf);
+		return udev_remove_rule(type, id, true);
 
 	cfg_label = get_label_id("cfg", type, id);
 	end_label = get_label_id("end", type, id);
 
-	/* Apply attributes in correct order. */
-	list = setting_list_get_sorted(state->settings);
-
-	path = path_get_udev_rule(type, id, autoconf);
+	path = path_get_udev_rule(type, id, true);
 	debug("Writing %s udev rule file %s\n", type, path);
 	if (!util_path_exists(path)) {
 		rc = path_create(path);
@@ -196,22 +289,8 @@ exit_code_t udev_ccw_write_device(struct device *dev, bool autoconf)
 	}
 	fprintf(fd, "GOTO=\"%s\"\n", end_label);
 	fprintf(fd, "\n");
-	fprintf(fd, "LABEL=\"%s\"\n", cfg_label);
 
-	/* Write settings. */
-	util_list_iterate(list, p) {
-		s = p->ptr;
-		if (s->removed)
-			continue;
-		if ((s->attrib && s->attrib->internal) ||
-		    internal_by_name(s->name)) {
-			fprintf(fd, "ENV{zdev_%s}=\"%s\"\n",
-				internal_get_name(s->name), s->value);
-		} else {
-			fprintf(fd, "ATTR{[ccw/%s]%s}=\"%s\"\n", id, s->name,
-				s->value);
-		}
-	}
+	write_attr_to_file(fd, state, id);
 
 	/* Write udev rule epilog. */
 	fprintf(fd, "\n");
@@ -221,7 +300,6 @@ exit_code_t udev_ccw_write_device(struct device *dev, bool autoconf)
 		warn("Could not close file %s: %s\n", path, strerror(errno));
 
 out:
-	ptrlist_free(list, 0);
 	free(end_label);
 	free(cfg_label);
 	free(path);
@@ -229,6 +307,150 @@ out:
 	return rc;
 }
 
+/* Write the persistent configuration of a CCW device to a udev rule. */
+static exit_code_t udev_ccw_write_device_new(struct device *dev)
+{
+	struct subtype *st = dev->subtype;
+	struct ccw_subtype_data *data = st->data;
+	const char *type = st->name, *drv = data->any_driver ? "*" : data->ccwdrv, *id = dev->id;
+	char *path, *cfg_label = NULL, *end_label = NULL;
+	exit_code_t rc = EXIT_OK;
+	FILE *fd;
+	int i, configured = 0;
+
+	/*
+	 * Remove the previous file; The new udev rule will be created based on the
+	 * current configuration settings
+	 */
+	udev_remove_rule(type, id, 0);
+
+	/*
+	 * Copy the dev->persistent to the site_specific array; While writing the new
+	 * udev-rule we consider the site_specific array only
+	 */
+
+	dev_state_copy(&dev->site_specific[global_site_id], &dev->persistent);
+	for (i = 0; i < NUM_SITES; i++) {
+		configured += dev->site_specific[i].exists;
+		configured -= dev->site_specific[i].deconfigured;
+	}
+
+	/*
+	 * If there is no configuration settings available, do not create the new
+	 * udev-rule file; exit here
+	 */
+	if (!configured)
+		return rc;
+
+	cfg_label = get_label_id("cfg", type, id);
+	end_label = get_label_id("end", type, id);
+
+	path = path_get_udev_rule(type, id, false);
+	debug("Writing %s udev rule file %s\n", type, path);
+	if (!util_path_exists(path)) {
+		rc = path_create(path);
+		if (rc)
+			goto out;
+	}
+
+	fd = misc_fopen(path, "w");
+	if (!fd) {
+		error("Could not write to file %s: %s\n", path,
+		      strerror(errno));
+		rc = EXIT_RUNTIME_ERROR;
+		goto out;
+	}
+
+	/* Write udev rule prolog. */
+	fprintf(fd, "# Generated by chzdev\n");
+
+	if (drv) {
+		fprintf(fd, "ACTION==\"add\", SUBSYSTEM==\"ccw\", "
+			"KERNEL==\"%s\", DRIVER==\"%s\", GOTO=\"%s\"\n", id,
+			drv, cfg_label);
+		fprintf(fd, "ACTION==\"add\", SUBSYSTEM==\"drivers\", "
+			"KERNEL==\"%s\", TEST==\"[ccw/%s]\", "
+			"GOTO=\"%s\"\n", drv, id, cfg_label);
+	} else {
+		fprintf(fd, "ACTION==\"add\", SUBSYSTEM==\"ccw\", "
+			"KERNEL==\"%s\", GOTO=\"%s\"\n", id, cfg_label);
+	}
+	fprintf(fd, "GOTO=\"%s\"\n", end_label);
+	fprintf(fd, "\n");
+
+	fprintf(fd, "LABEL=\"%s\"\n", cfg_label);
+	/* site comparison block */
+	for (i = 0; i < NUM_USER_SITES; i++) {
+		if (dev->site_specific[i].exists &&
+		    !dev->site_specific[i].deconfigured) {
+			fprintf(fd, "ENV{ZDEV_SITE_ID}==\"%d\",GOTO=\"%s_site%d\"\n", i,
+				cfg_label, i);
+		}
+	}
+
+	/*
+	 * If we have a generic configuration available, then use that setting as a
+	 * fail-over incase of no site-id information in LOADPARM
+	 */
+	if (dev->site_specific[SITE_FALLBACK].exists &&
+	    !dev->site_specific[SITE_FALLBACK].deconfigured)
+		fprintf(fd, "GOTO=\"%s_site_fb\"\n", cfg_label);
+	else
+		fprintf(fd, "GOTO=\"%s\"\n", end_label);
+	fprintf(fd, "\n");
+
+	/* Write the site blocks for all the available configurations */
+	for (i = 0; i < NUM_USER_SITES; i++) {
+		if (dev->site_specific[i].exists &&
+		    !dev->site_specific[i].deconfigured) {
+			fprintf(fd, "# site_start_%d\n", i);
+			fprintf(fd, "LABEL=\"%s_site%d\"\n", cfg_label, i);
+
+			write_attr_to_file(fd, &dev->site_specific[i], id);
+			/* Write udev rule epilog. */
+			fprintf(fd, "GOTO=\"%s\"\n", end_label);
+			fprintf(fd, "# site_end_%d\n", i);
+			fprintf(fd, "\n");
+		}
+	}
+	if (dev->site_specific[SITE_FALLBACK].exists &&
+	    !dev->site_specific[SITE_FALLBACK].deconfigured) {
+		fprintf(fd, "# site_start_fb\n");
+		fprintf(fd, "LABEL=\"%s_site_fb\"\n", cfg_label);
+
+		write_attr_to_file(fd, &dev->site_specific[i], id);
+		/* Write udev rule epilog. */
+		fprintf(fd, "GOTO=\"%s\"\n", end_label);
+		fprintf(fd, "# site_end_fb\n");
+		fprintf(fd, "\n");
+	}
+
+	/* Write udev rule epilog. */
+	fprintf(fd, "\n");
+	fprintf(fd, "LABEL=\"%s\"\n", end_label);
+
+	if (misc_fclose(fd))
+		warn("Could not close file %s: %s\n", path, strerror(errno));
+
+	rc = udev_write_site_rule();
+	if (rc)
+		goto out;
+out:
+	free(end_label);
+	free(cfg_label);
+	free(path);
+
+	return rc;
+}
+
+exit_code_t udev_ccw_write_device(struct device *dev, bool autoconf)
+{
+	if (autoconf)
+		return udev_ccw_write_device_legacy(dev, autoconf);
+	else
+		return udev_ccw_write_device_new(dev);
+}
+
 #define MARKER	"echo free "
 
 static char *read_cio_ignore(const char *path)
@@ -300,6 +522,7 @@ exit_code_t udev_ccw_write_cio_ignore(const char *id_list, bool autoconf)
 
 	/* Write udev rule. */
 	fprintf(fd, "# Generated by chzdev\n");
+
 	fprintf(fd, "ACTION==\"add\", SUBSYSTEM==\"subsystem\", "
 		"KERNEL==\"ccw\", RUN{program}+=\"/bin/sh -c "
 		"'echo free %s > /proc/cio_ignore'\"\n", id_list);