+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;
+
+ if (strncmp(fstype, "btrfs", strlen("btrfs")))
+ return dev->mount_path;
+
+ /* 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;
+ }
+
+ talloc_free(path);
+ return dev->mount_path;
+}
+