diff --git a/block.c b/block.c index c6786cd35b..a5e69ad81e 100644 --- a/block.c +++ b/block.c @@ -2983,6 +2983,53 @@ BlockDriverState *bdrv_open(const char *filename, const char *reference, NULL, errp); } +/* 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; +} + /* * Returns true if @child can be reached recursively from @bs */ @@ -3546,6 +3593,17 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue, } if (drv->bdrv_reopen_prepare) { + /* + * If a driver-specific option is missing, it means that we + * should reset it to its default value. + * But not all options allow that, so we need to check it first. + */ + ret = bdrv_reset_options_allowed(reopen_state->bs, + reopen_state->options, errp); + if (ret) { + goto error; + } + ret = drv->bdrv_reopen_prepare(reopen_state, queue, &local_err); if (ret) { if (local_err != NULL) {