discover: Add 'sync' user event

Add a user event named 'sync' that causes the discover server to merge
the devicemapper snapshots of mounted devices. This is particularly
useful as a debug aid (for example, when copying logs to a USB device),
as the server will otherwise only sync changes to mounted devices in
response to parser actions.

The command can be called as

	pb-event sync@device

to sync a particular device, or as

	pb-event sync@all

to sync all devices with snapshots.

Signed-off-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/discover/user-event.c b/discover/user-event.c
index 15d9c87..7350b6c 100644
--- a/discover/user-event.c
+++ b/discover/user-event.c
@@ -60,6 +60,8 @@ static const char *event_action_name(enum event_action action)
 		return "dhcp";
 	case EVENT_ACTION_BOOT:
 		return "boot";
+	case EVENT_ACTION_SYNC:
+		return "sync";
 	default:
 		break;
 	}
@@ -464,6 +466,18 @@ static int user_event_boot(struct user_event *uev, struct event *event)
 	return 0;
 }
 
+static int user_event_sync(struct user_event *uev, struct event *event)
+{
+	struct device_handler *handler = uev->handler;
+
+	if (strncasecmp(event->device, "all", strlen("all")) != 0)
+		device_sync_snapshots(handler, event->device);
+	else
+		device_sync_snapshots(handler, NULL);
+
+	return 0;
+}
+
 static void user_event_handle_message(struct user_event *uev, char *buf,
 	int len)
 {
@@ -499,6 +513,9 @@ static void user_event_handle_message(struct user_event *uev, char *buf,
 	case EVENT_ACTION_BOOT:
 		result = user_event_boot(uev, event);
 		break;
+	case EVENT_ACTION_SYNC:
+		result = user_event_sync(uev, event);
+		break;
 	default:
 		break;
 	}