+/* Return true if the NULL-terminated @list contains @str */
+static bool is_str_in_list(const char *str, const char *const *list)
+{
+ if (str && list) {
+ int i;
+ for (i = 0; list[i] != NULL; i++) {
+ if (!strcmp(str, list[i])) {
+ return true;
+ }
+ }
+ }
+ return false;
+}
+
+/*
+ * Check that every option set in @bs->options is also set in
+ * @new_opts.
+ *
+ * Options listed in the common_options list and in
+ * @bs->drv->mutable_opts are skipped.
+ *
+ * Return 0 on success, otherwise return -EINVAL and set @errp.
+ */
+static int bdrv_reset_options_allowed(BlockDriverState *bs,
+ const QDict *new_opts, Error **errp)
+{
+ const QDictEntry *e;
+ /* These options are common to all block drivers and are handled
+ * in bdrv_reopen_prepare() so they can be left out of @new_opts */
+ const char *const common_options[] = {
+ "node-name", "discard", "cache.direct", "cache.no-flush",
+ "read-only", "auto-read-only", "detect-zeroes", NULL
+ };
+
+ for (e = qdict_first(bs->options); e; e = qdict_next(bs->options, e)) {
+ if (!qdict_haskey(new_opts, e->key) &&
+ !is_str_in_list(e->key, common_options) &&
+ !is_str_in_list(e->key, bs->drv->mutable_opts)) {
+ error_setg(errp, "Option '%s' cannot be reset "
+ "to its default value", e->key);
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+