X-Git-Url: http://git.ozlabs.org/?p=petitboot;a=blobdiff_plain;f=discover%2Fdevice-handler.c;h=a0c21b71b906e5eea8c3d986a6bb9c4d3f9fc921;hp=4e25e079ca18185e21ec187e57a5cd09f9315e0f;hb=417265c68731537deeed22a3a3530cd6dd986513;hpb=6c1a9dda927ec7404a55d4e11c3c9c47b4b52dce

diff --git a/discover/device-handler.c b/discover/device-handler.c
index 4e25e07..a0c21b7 100644
--- a/discover/device-handler.c
+++ b/discover/device-handler.c
@@ -19,6 +19,7 @@
 #include <url/url.h>
 #include <i18n/i18n.h>
 
+#include <sys/sysmacros.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netdb.h>
@@ -46,6 +47,14 @@ enum default_priority {
 	DEFAULT_PRIORITY_DISABLED	= 0xff,
 };
 
+struct progress_info {
+	unsigned int			percentage;
+	unsigned long			size;		/* size in bytes */
+
+	const struct process_info	*procinfo;
+	struct list_item	list;
+};
+
 struct device_handler {
 	struct discover_server	*server;
 	int			dry_run;
@@ -72,6 +81,9 @@ struct device_handler {
 
 	struct boot_task	*pending_boot;
 	bool			pending_boot_is_default;
+
+	struct list		progress;
+	unsigned int		n_progress;
 };
 
 static int mount_device(struct discover_device *dev);
@@ -114,6 +126,12 @@ const struct discover_device *device_handler_get_device(
 	return handler->devices[index];
 }
 
+struct network *device_handler_get_network(
+		const struct device_handler *handler)
+{
+	return handler->network;
+}
+
 struct discover_boot_option *discover_boot_option_create(
 		struct discover_context *ctx,
 		struct discover_device *device)
@@ -221,17 +239,22 @@ static int destroy_device(void *arg)
 }
 
 struct discover_device *discover_device_create(struct device_handler *handler,
-		const char *id)
+		const char *uuid, const char *id)
 {
 	struct discover_device *dev;
 
-	dev = device_lookup_by_id(handler, id);
+	if (uuid)
+		dev = device_lookup_by_uuid(handler, uuid);
+	else
+		dev = device_lookup_by_id(handler, id);
+
 	if (dev)
 		return dev;
 
 	dev = talloc_zero(handler, struct discover_device);
 	dev->device = talloc_zero(dev, struct device);
 	dev->device->id = talloc_strdup(dev->device, id);
+	dev->uuid = talloc_strdup(dev, uuid);
 	list_init(&dev->params);
 	list_init(&dev->boot_options);
 
@@ -299,10 +322,12 @@ struct device_handler *device_handler_init(struct discover_server *server,
 	handler->server = server;
 	handler->waitset = waitset;
 	handler->dry_run = dry_run;
-	handler->autoboot_enabled = config_get()->autoboot_enabled;
+	handler->autoboot_enabled = config_autoboot_active(config_get());
 
 	list_init(&handler->unresolved_boot_options);
 
+	list_init(&handler->progress);
+
 	/* set up our mount point base */
 	pb_mkdir_recursive(mount_base());
 
@@ -327,6 +352,15 @@ void device_handler_reinit(struct device_handler *handler)
 	unsigned int i;
 
 	device_handler_cancel_default(handler);
+	/* Cancel any pending non-default boot */
+	if (handler->pending_boot) {
+		boot_cancel(handler->pending_boot);
+		handler->pending_boot = NULL;
+		handler->pending_boot_is_default = false;
+	}
+
+	/* Cancel any remaining async jobs */
+	process_stop_async_all();
 
 	/* free unresolved boot options */
 	list_for_each_entry_safe(&handler->unresolved_boot_options,
@@ -359,6 +393,15 @@ void device_handler_remove(struct device_handler *handler,
 	struct discover_boot_option *opt, *tmp;
 	unsigned int i;
 
+	list_for_each_entry_safe(&device->boot_options, opt, tmp, list) {
+		if (opt == handler->default_boot_option) {
+			pb_log("Default option %s cancelled since device removed",
+					opt->option->name);
+			device_handler_cancel_default(handler);
+			break;
+		}
+	}
+
 	for (i = 0; i < handler->n_devices; i++)
 		if (handler->devices[i] == device)
 			break;
@@ -396,25 +439,198 @@ void device_handler_remove(struct device_handler *handler,
 	talloc_free(device);
 }
 
-static void boot_status(void *arg, struct boot_status *status)
+void device_handler_status(struct device_handler *handler,
+		struct status *status)
 {
-	struct device_handler *handler = arg;
-
 	discover_server_notify_boot_status(handler->server, status);
 }
 
+static void _device_handler_vstatus(struct device_handler *handler,
+		enum status_type type, const char *fmt, va_list ap)
+{
+	struct status status;
+
+	status.type = type;
+	status.message = talloc_vasprintf(handler, fmt, ap);
+	status.backlog = false;
+
+	device_handler_status(handler, &status);
+
+	talloc_free(status.message);
+}
+
+static void _device_handler_vdevstatus(struct device_handler *handler,
+		struct discover_device *device, enum status_type type,
+		const char *fmt, va_list ap)
+{
+	char *msg;
+
+	msg = talloc_asprintf(handler, "[%s] %s",
+			device ? device->device->id : "unknown", fmt);
+	_device_handler_vstatus(handler, type, msg, ap);
+	talloc_free(msg);
+}
+
+void device_handler_status_dev_info(struct device_handler *handler,
+		struct discover_device *dev, const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	_device_handler_vdevstatus(handler, dev, STATUS_INFO, fmt, ap);
+	va_end(ap);
+}
+
+void device_handler_status_dev_err(struct device_handler *handler,
+		struct discover_device *dev, const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	_device_handler_vdevstatus(handler, dev, STATUS_ERROR, fmt, ap);
+	va_end(ap);
+}
+
+void device_handler_status_info(struct device_handler *handler,
+		const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	_device_handler_vstatus(handler, STATUS_INFO, fmt, ap);
+	va_end(ap);
+}
+
+void device_handler_status_err(struct device_handler *handler,
+		const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	_device_handler_vstatus(handler, STATUS_ERROR, fmt, ap);
+	va_end(ap);
+}
+
+void device_handler_status_download(struct device_handler *handler,
+		const struct process_info *procinfo,
+		unsigned int percentage, unsigned int size, char suffix)
+{
+	struct progress_info *p, *progress = NULL;
+	uint64_t current_converted, current = 0;
+	const char *units = " kMGTP";
+	unsigned long size_bytes;
+	char *update = NULL;
+	double total = 0;
+	unsigned int i;
+	int unit = 0;
+
+	list_for_each_entry(&handler->progress, p, list)
+		if (p->procinfo == procinfo)
+			progress = p;
+
+	if (!progress) {
+		pb_log("Registering new progress struct\n");
+		progress = talloc_zero(handler, struct progress_info);
+		if (!progress) {
+			pb_log("Failed to allocate room for progress struct\n");
+			return;
+		}
+		progress->procinfo = procinfo;
+		list_add(&handler->progress, &progress->list);
+		handler->n_progress++;
+	}
+
+	size_bytes = size;
+	for (i = 0; i < strlen(units); i++) {
+		if (units[i] == suffix)
+			break;
+	}
+
+	if (i >= strlen(units)) {
+	    pb_log("Couldn't recognise suffix '%c'\n", suffix);
+	    size_bytes = 0;
+	} else {
+		while (i--)
+			size_bytes <<= 10;
+	}
+
+	progress->percentage = percentage;
+	progress->size = size_bytes;
+
+	/*
+	 * Aggregate the info we have and update status. If a progress struct
+	 * has zero for both percentage and size we assume progress information
+	 * is unavailable and fall back to a generic progress message.
+	 */
+	list_for_each_entry(&handler->progress, p, list) {
+		uint64_t c;
+		double t;
+		if (!p->percentage || !p->size) {
+			update = talloc_asprintf(handler,
+					_("%u downloads in progress..."),
+					handler->n_progress);
+			current = total = 0;
+			break;
+		}
+
+		c = p->size;
+		t = (100 * c) / p->percentage;
+
+		current += c;
+		total += t;
+	}
+
+	if (total) {
+		current_converted = current;
+		while (current_converted >= 1000) {
+			current_converted >>= 10;
+			unit++;
+		}
+		update = talloc_asprintf(handler,
+				_("%u %s downloading: %.0f%% - %lu%cB"),
+				handler->n_progress,
+				ngettext("item", "items", handler->n_progress),
+				(current / total) * 100, current_converted,
+				units[unit]);
+	}
+
+	if (!update) {
+		pb_log("%s: failed to allocate new status\n", __func__);
+	} else {
+		device_handler_status_info(handler, "%s\n", update);
+		talloc_free(update);
+	}
+}
+
+void device_handler_status_download_remove(struct device_handler *handler,
+		struct process_info *procinfo)
+{
+	struct progress_info *p, *tmp;
+
+	list_for_each_entry_safe(&handler->progress, p, tmp, list)
+		if (p->procinfo == procinfo) {
+			list_remove(&p->list);
+			talloc_free(p);
+			handler->n_progress--;
+		}
+}
+
+static void device_handler_boot_status_cb(void *arg, struct status *status)
+{
+	device_handler_status(arg, status);
+}
+
 static void countdown_status(struct device_handler *handler,
 		struct discover_boot_option *opt, unsigned int sec)
 {
-	struct boot_status status;
+	struct status status;
 
-	status.type = BOOT_STATUS_INFO;
-	status.progress = -1;
-	status.detail = NULL;
+	status.type = STATUS_INFO;
 	status.message = talloc_asprintf(handler,
 			_("Booting in %d sec: %s"), sec, opt->option->name);
+	status.backlog = false;
 
-	discover_server_notify_boot_status(handler->server, &status);
+	device_handler_status(handler, &status);
 
 	talloc_free(status.message);
 }
@@ -445,8 +661,11 @@ static int default_timeout(void *arg)
 
 	pb_log("Timeout expired, booting default option %s\n", opt->option->id);
 
+	platform_pre_boot();
+
 	handler->pending_boot = boot(handler, handler->default_boot_option,
-			NULL, handler->dry_run, boot_status, handler);
+			NULL, handler->dry_run, device_handler_boot_status_cb,
+			handler);
 	handler->pending_boot_is_default = true;
 	return 0;
 }
@@ -601,6 +820,7 @@ static bool __attribute__((used)) boot_option_is_resolved(
 	return resource_is_resolved(opt->boot_image) &&
 		resource_is_resolved(opt->initrd) &&
 		resource_is_resolved(opt->dtb) &&
+		resource_is_resolved(opt->args_sig_file) &&
 		resource_is_resolved(opt->icon);
 }
 
@@ -626,6 +846,8 @@ static bool boot_option_resolve(struct discover_boot_option *opt,
 	return resource_resolve(opt->boot_image, "boot_image", opt, handler) &&
 		resource_resolve(opt->initrd, "initrd", opt, handler) &&
 		resource_resolve(opt->dtb, "dtb", opt, handler) &&
+		resource_resolve(opt->args_sig_file, "args_sig_file", opt,
+			handler) &&
 		resource_resolve(opt->icon, "icon", opt, handler);
 }
 
@@ -640,6 +862,7 @@ static void boot_option_finalise(struct device_handler *handler,
 	assert(!opt->option->dtb_file);
 	assert(!opt->option->icon_file);
 	assert(!opt->option->device_id);
+	assert(!opt->option->args_sig_file);
 
 	if (opt->boot_image)
 		opt->option->boot_image_file = opt->boot_image->url->full;
@@ -649,6 +872,8 @@ static void boot_option_finalise(struct device_handler *handler,
 		opt->option->dtb_file = opt->dtb->url->full;
 	if (opt->icon)
 		opt->option->icon_file = opt->icon->url->full;
+	if (opt->args_sig_file)
+		opt->option->args_sig_file = opt->args_sig_file->url->full;
 
 	opt->option->device_id = opt->device->device->id;
 
@@ -698,57 +923,13 @@ struct discover_context *device_handler_discover_context_create(
 	struct discover_context *ctx;
 
 	ctx = talloc_zero(handler, struct discover_context);
+	ctx->handler = handler;
 	ctx->device = device;
-	ctx->network = handler->network;
 	list_init(&ctx->boot_options);
 
 	return ctx;
 }
 
-/**
- * context_commit - Commit a temporary discovery context to the handler,
- * and notify the clients about any new options / devices
- */
-void device_handler_discover_context_commit(struct device_handler *handler,
-		struct discover_context *ctx)
-{
-	struct discover_device *dev = ctx->device;
-	struct discover_boot_option *opt, *tmp;
-
-	if (!device_lookup_by_id(handler, dev->device->id))
-		device_handler_add_device(handler, dev);
-
-	/* move boot options from the context to the device */
-	list_for_each_entry_safe(&ctx->boot_options, opt, tmp, list) {
-		list_remove(&opt->list);
-
-		if (boot_option_resolve(opt, handler)) {
-			pb_log("boot option %s is resolved, "
-					"sending to clients\n",
-					opt->option->id);
-			list_add_tail(&dev->boot_options, &opt->list);
-			talloc_steal(dev, opt);
-			boot_option_finalise(handler, opt);
-			notify_boot_option(handler, opt);
-		} else {
-			if (!opt->source->resolve_resource) {
-				pb_log("parser %s gave us an unresolved "
-					"resource (%s), but no way to "
-					"resolve it\n",
-					opt->source->name, opt->option->id);
-				talloc_free(opt);
-			} else {
-				pb_log("boot option %s is unresolved, "
-						"adding to queue\n",
-						opt->option->id);
-				list_add(&handler->unresolved_boot_options,
-						&opt->list);
-				talloc_steal(handler, opt);
-			}
-		}
-	}
-}
-
 void device_handler_add_device(struct device_handler *handler,
 		struct discover_device *device)
 {
@@ -857,17 +1038,16 @@ int device_handler_discover(struct device_handler *handler,
 		struct discover_device *dev)
 {
 	struct discover_context *ctx;
-	struct boot_status *status;
 	int rc;
 
-	status = talloc_zero(handler, struct boot_status);
-	status->type = BOOT_STATUS_INFO;
-	status->message = talloc_asprintf(status, "Processing %s device %s",
-				device_type_display_name(dev->device->type),
-				dev->device->id);
-	boot_status(handler, status);
-
-	process_boot_option_queue(handler);
+	device_handler_status_dev_info(handler, dev,
+		/*
+		 * TRANSLATORS: this string will be passed the type of the
+		 * device (eg "disk" or "network"), which will be translated
+		 * accordingly.
+		 */
+		_("Processing new %s device"),
+		device_type_display_name(dev->device->type));
 
 	/* create our context */
 	ctx = device_handler_discover_context_create(handler, dev);
@@ -886,13 +1066,9 @@ int device_handler_discover(struct device_handler *handler,
 	/* add discovered stuff to the handler */
 	device_handler_discover_context_commit(handler, ctx);
 
+	process_boot_option_queue(handler);
 out:
-	status->message = talloc_asprintf(status,"Processing %s complete\n",
-				dev->device->id);
-	boot_status(handler, status);
-
-	talloc_free(status);
-	talloc_free(ctx);
+	talloc_unlink(handler, ctx);
 
 	return 0;
 }
@@ -902,58 +1078,21 @@ int device_handler_dhcp(struct device_handler *handler,
 		struct discover_device *dev, struct event *event)
 {
 	struct discover_context *ctx;
-	struct boot_status *status;
 
-	status = talloc_zero(handler, struct boot_status);
-	status->type = BOOT_STATUS_INFO;
-	status->message = talloc_asprintf(status, "Processing dhcp event on %s",
-				dev->device->id);
-	boot_status(handler, status);
+	device_handler_status_dev_info(handler, dev,
+			_("Processing DHCP lease response (ip: %s)"),
+			event_get_param(event, "ip"));
 
 	/* create our context */
 	ctx = device_handler_discover_context_create(handler, dev);
+	talloc_steal(ctx, event);
 	ctx->event = event;
 
 	iterate_parsers(ctx);
 
 	device_handler_discover_context_commit(handler, ctx);
 
-	status->message = talloc_asprintf(status,"Processing %s complete\n",
-				dev->device->id);
-	boot_status(handler, status);
-
-	talloc_free(status);
-	talloc_free(ctx);
-
-	return 0;
-}
-
-/* incoming conf event */
-int device_handler_conf(struct device_handler *handler,
-		struct discover_device *dev, struct pb_url *url)
-{
-	struct discover_context *ctx;
-	struct boot_status *status;
-
-	status = talloc_zero(handler, struct boot_status);
-	status->type = BOOT_STATUS_INFO;
-	status->message = talloc_asprintf(status, "Processing user config");
-	boot_status(handler, status);
-
-	/* create our context */
-	ctx = device_handler_discover_context_create(handler, dev);
-	ctx->conf_url = url;
-
-	iterate_parsers(ctx);
-
-	device_handler_discover_context_commit(handler, ctx);
-
-	status->message = talloc_asprintf(status,
-				"Processing user config complete");
-	boot_status(handler, status);
-
-	talloc_free(status);
-	talloc_free(ctx);
+	talloc_unlink(handler, ctx);
 
 	return 0;
 }
@@ -989,14 +1128,12 @@ void device_handler_boot(struct device_handler *handler,
 	platform_pre_boot();
 
 	handler->pending_boot = boot(handler, opt, cmd, handler->dry_run,
-			boot_status, handler);
+			device_handler_boot_status_cb, handler);
 	handler->pending_boot_is_default = false;
 }
 
 void device_handler_cancel_default(struct device_handler *handler)
 {
-	struct boot_status status;
-
 	if (handler->timeout_waiter)
 		waiter_remove(handler->timeout_waiter);
 
@@ -1017,12 +1154,7 @@ void device_handler_cancel_default(struct device_handler *handler)
 
 	handler->default_boot_option = NULL;
 
-	status.type = BOOT_STATUS_INFO;
-	status.progress = -1;
-	status.detail = NULL;
-	status.message = _("Default boot cancelled");
-
-	discover_server_notify_boot_status(handler->server, &status);
+	device_handler_status_info(handler, _("Default boot cancelled"));
 }
 
 void device_handler_update_config(struct device_handler *handler,
@@ -1081,10 +1213,12 @@ static char *device_from_addr(void *ctx, struct pb_url *url)
 
 	rc = process_run_sync(p);
 
-	if (rc) {
+	if (rc || p->exit_status) {
 		/* ip has complained for some reason; most likely
 		 * there is no route to the host - bail out */
-		pb_debug("%s: No route to %s\n",__func__,url->host);
+		pb_debug("%s: `ip` returns non-zero exit status\n", __func__);
+		pb_debug("ip buf: %s\n", p->stdout_buf);
+		process_release(p);
 		return NULL;
 	}
 
@@ -1107,75 +1241,130 @@ static char *device_from_addr(void *ctx, struct pb_url *url)
 	return dev;
 }
 
-
 void device_handler_process_url(struct device_handler *handler,
-		const char *url)
+		const char *url, const char *mac, const char *ip)
 {
 	struct discover_context *ctx;
 	struct discover_device *dev;
-	struct boot_status *status;
 	struct pb_url *pb_url;
 	struct event *event;
 	struct param *param;
 
-	status = talloc(handler, struct boot_status);
-
-	status->type = BOOT_STATUS_ERROR;
-	status->progress = 0;
-	status->detail = talloc_asprintf(status,
-			_("Received config URL %s"), url);
-
 	if (!handler->network) {
-		status->message = talloc_asprintf(handler,
-					_("No network configured"));
-		goto msg;
+		device_handler_status_err(handler, _("No network configured"));
+		return;
 	}
 
 	event = talloc(handler, struct event);
 	event->type = EVENT_TYPE_USER;
-	event->action = EVENT_ACTION_CONF;
-
-	event->params = talloc_array(event, struct param, 1);
-	param = &event->params[0];
-	param->name = talloc_strdup(event, "pxeconffile");
-	param->value = talloc_strdup(event, url);
-	event->n_params = 1;
+	event->action = EVENT_ACTION_URL;
+
+	if (url[strlen(url) - 1] == '/') {
+		event->params = talloc_array(event, struct param, 3);
+		param = &event->params[0];
+		param->name = talloc_strdup(event, "pxepathprefix");
+		param->value = talloc_strdup(event, url);
+		param = &event->params[1];
+		param->name = talloc_strdup(event, "mac");
+		param->value = talloc_strdup(event, mac);
+		param = &event->params[2];
+		param->name = talloc_strdup(event, "ip");
+		param->value = talloc_strdup(event, ip);
+		event->n_params = 3;
+	} else {
+		event->params = talloc_array(event, struct param, 1);
+		param = &event->params[0];
+		param->name = talloc_strdup(event, "pxeconffile");
+		param->value = talloc_strdup(event, url);
+		event->n_params = 1;
+	}
 
 	pb_url = pb_url_parse(event, event->params->value);
-	if (!pb_url || !pb_url->host) {
-		status->message = talloc_asprintf(handler,
-					_("Invalid config URL!"));
-		goto msg;
+	if (!pb_url || (pb_url->scheme != pb_url_file && !pb_url->host)) {
+		device_handler_status_err(handler, _("Invalid config URL!"));
+		return;
 	}
 
-	event->device = device_from_addr(event, pb_url);
+	if (pb_url->scheme == pb_url_file)
+		event->device = talloc_asprintf(event, "local");
+	else
+		event->device = device_from_addr(event, pb_url);
+
 	if (!event->device) {
-		status->message = talloc_asprintf(status,
+		device_handler_status_err(handler,
 					_("Unable to route to host %s"),
 					pb_url->host);
-		goto msg;
+		return;
 	}
 
-	dev = discover_device_create(handler, event->device);
+	dev = discover_device_create(handler, mac, event->device);
+	if (pb_url->scheme == pb_url_file)
+		dev->device->type = DEVICE_TYPE_ANY;
 	ctx = device_handler_discover_context_create(handler, dev);
+	talloc_steal(ctx, event);
 	ctx->event = event;
 
 	iterate_parsers(ctx);
 
 	device_handler_discover_context_commit(handler, ctx);
 
-	talloc_free(ctx);
-
-	status->type = BOOT_STATUS_INFO;
-	status->message = talloc_asprintf(status, _("Config file %s parsed"),
-					pb_url->file);
-msg:
-	boot_status(handler, status);
-	talloc_free(status);
+	talloc_unlink(handler, ctx);
 }
 
 #ifndef PETITBOOT_TEST
 
+/**
+ * context_commit - Commit a temporary discovery context to the handler,
+ * and notify the clients about any new options / devices
+ */
+void device_handler_discover_context_commit(struct device_handler *handler,
+		struct discover_context *ctx)
+{
+	struct discover_device *dev = ctx->device;
+	struct discover_boot_option *opt, *tmp;
+
+	if (!device_lookup_by_uuid(handler, dev->uuid))
+		device_handler_add_device(handler, dev);
+
+	/* move boot options from the context to the device */
+	list_for_each_entry_safe(&ctx->boot_options, opt, tmp, list) {
+		list_remove(&opt->list);
+
+		/* All boot options need at least a kernel image */
+		if (!opt->boot_image || !opt->boot_image->url) {
+			pb_log("boot option %s is missing boot image, ignoring\n",
+				opt->option->id);
+			talloc_free(opt);
+			continue;
+		}
+
+		if (boot_option_resolve(opt, handler)) {
+			pb_log("boot option %s is resolved, "
+					"sending to clients\n",
+					opt->option->id);
+			list_add_tail(&dev->boot_options, &opt->list);
+			talloc_steal(dev, opt);
+			boot_option_finalise(handler, opt);
+			notify_boot_option(handler, opt);
+		} else {
+			if (!opt->source->resolve_resource) {
+				pb_log("parser %s gave us an unresolved "
+					"resource (%s), but no way to "
+					"resolve it\n",
+					opt->source->name, opt->option->id);
+				talloc_free(opt);
+			} else {
+				pb_log("boot option %s is unresolved, "
+						"adding to queue\n",
+						opt->option->id);
+				list_add(&handler->unresolved_boot_options,
+						&opt->list);
+				talloc_steal(handler, opt);
+			}
+		}
+	}
+}
+
 static void device_handler_update_lang(const char *lang)
 {
 	const char *cur_lang;
@@ -1218,6 +1407,8 @@ static void device_handler_reinit_sources(struct device_handler *handler)
 		return;
 	}
 
+	system_info_reinit();
+
 	udev_reinit(handler->udev);
 
 	network_shutdown(handler->network);
@@ -1225,33 +1416,31 @@ static void device_handler_reinit_sources(struct device_handler *handler)
 			handler->dry_run);
 }
 
-static const char *fs_parameters(struct discover_device *dev,
-				 unsigned int rw_flags)
+static inline const char *get_device_path(struct discover_device *dev)
 {
-	const char *fstype = discover_device_get_param(dev, "ID_FS_TYPE");
-
-	/* XFS journals are not cross-endian compatible; don't try recovery
-	 * even if we have a snapshot */
-	if (!strncmp(fstype, "xfs", strlen("xfs")))
-		return "norecovery";
-
-	/* If we have a snapshot available allow touching the filesystem */
-	if (dev->ramdisk)
-		return "";
+	return dev->ramdisk ? dev->ramdisk->snapshot : dev->device_path;
+}
 
-	if ((rw_flags | MS_RDONLY) != MS_RDONLY)
-		return "";
+static char *check_subvols(struct discover_device *dev)
+{
+	const char *fstype = discover_device_get_param(dev, "ID_FS_TYPE");
+	struct stat sb;
+	char *path;
+	int rc;
 
-	/* Avoid writes due to journal replay if we don't have a snapshot */
-	if (!strncmp(fstype, "ext4", strlen("ext4")))
-		return "norecovery";
+	if (strncmp(fstype, "btrfs", strlen("btrfs")))
+		return dev->mount_path;
 
-	return "";
-}
+	/* On btrfs a device's root may be under a subvolume path */
+	path = join_paths(dev, dev->mount_path, "@");
+	rc = stat(path, &sb);
+	if (!rc && S_ISDIR(sb.st_mode)) {
+		pb_debug("Using '%s' for btrfs root path\n", path);
+		return path;
+	}
 
-static inline const char *get_device_path(struct discover_device *dev)
-{
-	return dev->ramdisk ? dev->ramdisk->snapshot : dev->device_path;
+	talloc_free(path);
+	return dev->mount_path;
 }
 
 static bool check_existing_mount(struct discover_device *dev)
@@ -1295,6 +1484,7 @@ static bool check_existing_mount(struct discover_device *dev)
 
 		if (mntstat.st_rdev == devstat.st_rdev) {
 			dev->mount_path = talloc_strdup(dev, mnt->mnt_dir);
+			dev->root_path = check_subvols(dev);
 			dev->mounted_rw = !!hasmntopt(mnt, "rw");
 			dev->mounted = true;
 			dev->unmount = false;
@@ -1312,6 +1502,52 @@ static bool check_existing_mount(struct discover_device *dev)
 	return mnt != NULL;
 }
 
+/*
+ * Attempt to mount a filesystem safely, while handling certain filesytem-
+ * specific options
+ */
+static int try_mount(const char *device_path, const char *mount_path,
+			     const char *fstype, unsigned long flags,
+			     bool have_snapshot)
+{
+	const char *fs, *safe_opts;
+	int rc;
+
+	/* Mount ext3 as ext4 instead so 'norecovery' can be used */
+	if (strncmp(fstype, "ext3", strlen("ext3")) == 0) {
+		pb_debug("Mounting ext3 filesystem as ext4\n");
+		fs = "ext4";
+	} else
+		fs = fstype;
+
+	if (strncmp(fs, "xfs", strlen("xfs")) == 0 ||
+	    strncmp(fs, "ext4", strlen("ext4")) == 0)
+		safe_opts = "norecovery";
+	else
+		safe_opts = NULL;
+
+	errno = 0;
+	/* If no snapshot is available don't attempt recovery */
+	if (!have_snapshot)
+		return mount(device_path, mount_path, fs, flags, safe_opts);
+
+	rc = mount(device_path, mount_path, fs, flags, NULL);
+
+	if (!rc)
+		return rc;
+
+	/* Mounting failed; some filesystems will fail to mount if a recovery
+	 * journal exists (eg. cross-endian XFS), so try again with norecovery
+	 * where that option is available.
+	 * If mounting read-write just return the error as norecovery is not a
+	 * valid option */
+	if ((flags & MS_RDONLY) != MS_RDONLY || !safe_opts)
+		return rc;
+
+	errno = 0;
+	return mount(device_path, mount_path, fs, flags, safe_opts);
+}
+
 static int mount_device(struct discover_device *dev)
 {
 	const char *fstype, *device_path;
@@ -1330,13 +1566,6 @@ static int mount_device(struct discover_device *dev)
 	if (!fstype)
 		return 0;
 
-	/* ext3 treats the norecovery option as an error, so mount the device
-	 * as an ext4 filesystem instead */
-	if (!strncmp(fstype, "ext3", strlen("ext3"))) {
-		pb_debug("Mounting ext3 filesystem as ext4\n");
-		fstype = talloc_asprintf(dev, "ext4");
-	}
-
 	dev->mount_path = join_paths(dev, mount_base(),
 					dev->device_path);
 
@@ -1349,14 +1578,14 @@ static int mount_device(struct discover_device *dev)
 	device_path = get_device_path(dev);
 
 	pb_log("mounting device %s read-only\n", dev->device_path);
-	errno = 0;
-	rc = mount(device_path, dev->mount_path, fstype,
-			MS_RDONLY | MS_SILENT,
-			fs_parameters(dev, MS_RDONLY));
+	rc = try_mount(device_path, dev->mount_path, fstype,
+		       MS_RDONLY | MS_SILENT, dev->ramdisk);
+
 	if (!rc) {
 		dev->mounted = true;
 		dev->mounted_rw = false;
 		dev->unmount = true;
+		dev->root_path = check_subvols(dev);
 		return 0;
 	}
 
@@ -1395,6 +1624,7 @@ static int umount_device(struct discover_device *dev)
 
 	talloc_free(dev->mount_path);
 	dev->mount_path = NULL;
+	dev->root_path = NULL;
 
 	return 0;
 }
@@ -1430,9 +1660,8 @@ int device_request_write(struct discover_device *dev, bool *release)
 		return -1;
 	}
 
-	rc = mount(device_path, dev->mount_path, fstype,
-			MS_SILENT,
-			fs_parameters(dev, MS_REMOUNT));
+	rc = try_mount(device_path, dev->mount_path, fstype,
+		       MS_SILENT, dev->ramdisk);
 	if (rc)
 		goto mount_ro;
 
@@ -1443,9 +1672,9 @@ int device_request_write(struct discover_device *dev, bool *release)
 mount_ro:
 	pb_log("Unable to remount device %s read-write: %s\n",
 	       device_path, strerror(errno));
-	if (mount(device_path, dev->mount_path, fstype,
-			MS_RDONLY | MS_SILENT,
-			fs_parameters(dev, MS_RDONLY)))
+	rc = try_mount(device_path, dev->mount_path, fstype,
+		       MS_RDONLY | MS_SILENT, dev->ramdisk);
+	if (rc)
 		pb_log("Unable to recover mount for %s: %s\n",
 		       device_path, strerror(errno));
 	return -1;
@@ -1454,7 +1683,6 @@ mount_ro:
 void device_release_write(struct discover_device *dev, bool release)
 {
 	const char *fstype, *device_path;
-	int rc = 0;
 
 	if (!release)
 		return;
@@ -1477,18 +1705,58 @@ void device_release_write(struct discover_device *dev, bool release)
 		device_path = get_device_path(dev);
 	}
 
-	mount(device_path, dev->mount_path, fstype,
-			MS_RDONLY | MS_SILENT,
-			fs_parameters(dev, MS_RDONLY));
-	if (rc)
+	if (try_mount(device_path, dev->mount_path, fstype,
+		       MS_RDONLY | MS_SILENT, dev->ramdisk))
 		pb_log("Failed to remount %s read-only: %s\n",
 		       device_path, strerror(errno));
 	else
 		dev->mounted = true;
 }
 
+void device_sync_snapshots(struct device_handler *handler, const char *device)
+{
+	struct discover_device *dev = NULL;
+	unsigned int i;
+
+	if (device) {
+		/* Find matching device and sync */
+		dev = device_lookup_by_name(handler, device);
+		if (!dev) {
+			pb_log("%s: device name '%s' unrecognised\n",
+				__func__, device);
+			return;
+		}
+		if (dev->ramdisk)
+			device_release_write(dev, true);
+		else
+			pb_log("%s has no snapshot to merge, skipping\n",
+				dev->device->id);
+		return;
+	}
+
+	/* Otherwise sync all relevant devices */
+	for (i = 0; i < handler->n_devices; i++) {
+		dev = handler->devices[i];
+		if (dev->device->type != DEVICE_TYPE_DISK &&
+			dev->device->type != DEVICE_TYPE_USB)
+			continue;
+		if (dev->ramdisk)
+			device_release_write(dev, true);
+		else
+			pb_log("%s has no snapshot to merge, skipping\n",
+				dev->device->id);
+	}
+}
+
 #else
 
+void device_handler_discover_context_commit(
+		struct device_handler *handler __attribute__((unused)),
+		struct discover_context *ctx __attribute__((unused)))
+{
+	pb_log("%s stubbed out for test cases\n", __func__);
+}
+
 static void device_handler_update_lang(const char *lang __attribute__((unused)))
 {
 }
@@ -1527,5 +1795,10 @@ void device_release_write(struct discover_device *dev __attribute__((unused)),
 {
 }
 
-#endif
+void device_sync_snapshots(
+		struct device_handler *handler __attribute__((unused)),
+		const char *device __attribute__((unused)))
+{
+}
 
+#endif