src/update_handler: filter out character devices as casync seeds

If extracting casync block-indexed images ("*.caibx") to a slot it could be of
advantage to use the slot's active counterpart as a casync seeding device. In
the case of UBI volume based slots those are char devices which can not be
handed out to casync. Instead one needs to derive related UBIBLOCK devices for
that purpose which have to be cleaned up afterwards. For the moment to simplify
things just discard the usage of seeding devices in that case.

Signed-off-by: Ulrich Ölmann <[email protected]>

src/update_handler.c

@@ -267,6 +267,14 @@ static gboolean casync_extract_image(RaucImage *image, gchar *dest, int out_fd,
 		g_debug("Adding as casync directory tree seed: %s", seedslot->mount_point);
 		seed = g_strdup(seedslot->mount_point);
 	} else {
+		GStatBuf seedstat;
+
+		/* For the moment do not utilize UBI volumes as seed because they are
+		 * character devices - additional logic is needed to (temporarily) map
+		 * them to UBIBLOCK devices which are suitable for that purpose */
+		if (g_stat(seedslot->device, &seedstat) < 0 || S_ISCHR(seedstat.st_mode))
+			goto extract;
+
 		g_debug("Adding as casync blob seed: %s", seedslot->device);
 		seed = g_strdup(seedslot->device);
 	}