Commit 2860b2b2 authored by Markus Armbruster's avatar Markus Armbruster Committed by Kevin Wolf
Browse files

block: Fix -blockdev / blockdev-add for empty objects and arrays 



-blockdev and blockdev-add silently ignore empty objects and arrays in
their argument.  That's because qmp_blockdev_add() converts the
argument to a flat QDict, and qdict_flatten() eats empty QDict and
QList members.  For instance, we ignore an empty BlockdevOptions
member @cache.  No real harm, as absent means the same as empty there.

Thus, the flaw puts an artificial restriction on the QAPI schema: we
can't have potentially empty objects and arrays within
BlockdevOptions, except when they're optional and "empty" has the same
meaning as "absent".

Our QAPI schema satisfies this restriction (I checked), but it's a
trap for the unwary, and a temptation to employ awkward workarounds
for the wary.  Let's get rid of it.

Change qdict_flatten() and qdict_crumple() to treat empty dictionaries
and lists exactly like scalars.

Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
Reviewed-by: default avatarKevin Wolf <kwolf@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent bef96b15

qobject/block-qdict.c

+33 −21
Original line number Diff line number Diff line
@@ -56,6 +56,8 @@ static void qdict_flatten_qlist(QList *qlist, QDict *target, const char *prefix) 
{

    QObject *value;

    const QListEntry *entry;

    QDict *dict_val;

    QList *list_val;

    char *new_key;

    int i;
@@ -69,16 +71,18 @@ static void qdict_flatten_qlist(QList *qlist, QDict *target, const char *prefix) 


    for (i = 0; entry; entry = qlist_next(entry), i++) {

        value = qlist_entry_obj(entry);

        dict_val = qobject_to(QDict, value);

        list_val = qobject_to(QList, value);

        new_key = g_strdup_printf("%s.%i", prefix, i);



        /*

         * Flatten non-empty QDict and QList recursively into @target,

         * copy other objects to @target

         */

        if (qobject_type(value) == QTYPE_QDICT) {

            qdict_flatten_qdict(qobject_to(QDict, value), target, new_key);

        } else if (qobject_type(value) == QTYPE_QLIST) {

            qdict_flatten_qlist(qobject_to(QList, value), target, new_key);

        if (dict_val && qdict_size(dict_val)) {

            qdict_flatten_qdict(dict_val, target, new_key);

        } else if (list_val && !qlist_empty(list_val)) {

            qdict_flatten_qlist(list_val, target, new_key);

        } else {

            qdict_put_obj(target, new_key, qobject_ref(value));

        }
@@ -91,6 +95,8 @@ static void qdict_flatten_qdict(QDict *qdict, QDict *target, const char *prefix) 
{

    QObject *value;

    const QDictEntry *entry, *next;

    QDict *dict_val;

    QList *list_val;

    char *new_key;



    entry = qdict_first(qdict);
@@ -98,6 +104,8 @@ static void qdict_flatten_qdict(QDict *qdict, QDict *target, const char *prefix) 
    while (entry != NULL) {

        next = qdict_next(qdict, entry);

        value = qdict_entry_value(entry);

        dict_val = qobject_to(QDict, value);

        list_val = qobject_to(QList, value);

        new_key = NULL;



        if (prefix) {
@@ -108,12 +116,12 @@ static void qdict_flatten_qdict(QDict *qdict, QDict *target, const char *prefix) 
         * Flatten non-empty QDict and QList recursively into @target,

         * copy other objects to @target

         */

        if (qobject_type(value) == QTYPE_QDICT) {

            qdict_flatten_qdict(qobject_to(QDict, value), target,

        if (dict_val && qdict_size(dict_val)) {

            qdict_flatten_qdict(dict_val, target,

                                new_key ? new_key : entry->key);

            qdict_del(qdict, entry->key);

        } else if (qobject_type(value) == QTYPE_QLIST) {

            qdict_flatten_qlist(qobject_to(QList, value), target,

        } else if (list_val && !qlist_empty(list_val)) {

            qdict_flatten_qlist(list_val, target,

                                new_key ? new_key : entry->key);

            qdict_del(qdict, entry->key);

        } else if (target != qdict) {
@@ -127,10 +135,11 @@ static void qdict_flatten_qdict(QDict *qdict, QDict *target, const char *prefix) 
}



/**

 * qdict_flatten(): For each nested QDict with key x, all fields with key y

 * are moved to this QDict and their key is renamed to "x.y". For each nested

 * QList with key x, the field at index y is moved to this QDict with the key

 * "x.y" (i.e., the reverse of what qdict_array_split() does).

 * qdict_flatten(): For each nested non-empty QDict with key x, all

 * fields with key y are moved to this QDict and their key is renamed

 * to "x.y". For each nested non-empty QList with key x, the field at

 * index y is moved to this QDict with the key "x.y" (i.e., the

 * reverse of what qdict_array_split() does).

 * This operation is applied recursively for nested QDicts and QLists.

 */

void qdict_flatten(QDict *qdict)
@@ -361,8 +370,8 @@ static int qdict_is_list(QDict *maybe_list, Error **errp) 
 * @src: the original flat dictionary (only scalar values) to crumple

 *

 * Takes a flat dictionary whose keys use '.' separator to indicate

 * nesting, and values are scalars, and crumples it into a nested

 * structure.

 * nesting, and values are scalars, empty dictionaries or empty lists,

 * and crumples it into a nested structure.

 *

 * To include a literal '.' in a key name, it must be escaped as '..'

 *
@@ -399,6 +408,8 @@ QObject *qdict_crumple(const QDict *src, Error **errp) 
{

    const QDictEntry *ent;

    QDict *two_level, *multi_level = NULL, *child_dict;

    QDict *dict_val;

    QList *list_val;

    QObject *dst = NULL, *child;

    size_t i;

    char *prefix = NULL;
@@ -409,10 +420,11 @@ QObject *qdict_crumple(const QDict *src, Error **errp) 


    /* Step 1: split our totally flat dict into a two level dict */

    for (ent = qdict_first(src); ent != NULL; ent = qdict_next(src, ent)) {

        if (qobject_type(ent->value) == QTYPE_QDICT ||

            qobject_type(ent->value) == QTYPE_QLIST) {

            error_setg(errp, "Value %s is not a scalar",

                       ent->key);

        dict_val = qobject_to(QDict, ent->value);

        list_val = qobject_to(QList, ent->value);

        if ((dict_val && qdict_size(dict_val))

            || (list_val && !qlist_empty(list_val))) {

            error_setg(errp, "Value %s is not flat", ent->key);

            goto error;

        }
@@ -451,9 +463,9 @@ QObject *qdict_crumple(const QDict *src, Error **errp) 
    multi_level = qdict_new();

    for (ent = qdict_first(two_level); ent != NULL;

         ent = qdict_next(two_level, ent)) {

        QDict *dict = qobject_to(QDict, ent->value);

        if (dict) {

            child = qdict_crumple(dict, errp);

        dict_val = qobject_to(QDict, ent->value);

        if (dict_val && qdict_size(dict_val)) {

            child = qdict_crumple(dict_val, errp);

            if (!child) {

                goto error;

            }

tests/check-block-qdict.c

+30 −8
Original line number Diff line number Diff line
@@ -79,10 +79,10 @@ static void qdict_flatten_test(void) 
     *     "e.1.2.b": 1,

     *     "f.c": 2,

     *     "f.d": 3,

     *     "g": 4

     *     "g": 4,

     *     "y.0": {},

     *     "z.a": []

     * }

     *

     * Note that "y" and "z" get eaten.

     */



    qdict_put_int(e_1_2, "a", 0);
@@ -117,8 +117,10 @@ static void qdict_flatten_test(void) 
    g_assert(qdict_get_int(root, "f.c") == 2);

    g_assert(qdict_get_int(root, "f.d") == 3);

    g_assert(qdict_get_int(root, "g") == 4);

    g_assert(!qdict_size(qdict_get_qdict(root, "y.0")));

    g_assert(qlist_empty(qdict_get_qlist(root, "z.a")));



    g_assert(qdict_size(root) == 8);

    g_assert(qdict_size(root) == 10);



    qobject_unref(root);

}
@@ -387,7 +389,8 @@ static void qdict_join_test(void) 
static void qdict_crumple_test_recursive(void)

{

    QDict *src, *dst, *rule, *vnc, *acl, *listen;

    QList *rules;

    QDict *empty, *empty_dict, *empty_list_0;

    QList *rules, *empty_list, *empty_dict_a;



    src = qdict_new();

    qdict_put_str(src, "vnc.listen.addr", "127.0.0.1");
@@ -399,10 +402,12 @@ static void qdict_crumple_test_recursive(void) 
    qdict_put_str(src, "vnc.acl.default", "deny");

    qdict_put_str(src, "vnc.acl..name", "acl0");

    qdict_put_str(src, "vnc.acl.rule..name", "acl0");

    qdict_put(src, "empty.dict.a", qlist_new());

    qdict_put(src, "empty.list.0", qdict_new());



    dst = qobject_to(QDict, qdict_crumple(src, &error_abort));

    g_assert(dst);

    g_assert_cmpint(qdict_size(dst), ==, 1);

    g_assert_cmpint(qdict_size(dst), ==, 2);



    vnc = qdict_get_qdict(dst, "vnc");

    g_assert(vnc);
@@ -440,6 +445,21 @@ static void qdict_crumple_test_recursive(void) 
    g_assert_cmpstr("acl0", ==, qdict_get_str(vnc, "acl.name"));

    g_assert_cmpstr("acl0", ==, qdict_get_str(acl, "rule.name"));



    empty = qdict_get_qdict(dst, "empty");

    g_assert(empty);

    g_assert_cmpint(qdict_size(empty), ==, 2);

    empty_dict = qdict_get_qdict(empty, "dict");

    g_assert(empty_dict);

    g_assert_cmpint(qdict_size(empty_dict), ==, 1);

    empty_dict_a = qdict_get_qlist(empty_dict, "a");

    g_assert(empty_dict_a && qlist_empty(empty_dict_a));

    empty_list = qdict_get_qlist(empty, "list");

    g_assert(empty_list);

    g_assert_cmpint(qlist_size(empty_list), ==, 1);

    empty_list_0 = qobject_to(QDict, qlist_pop(empty_list));

    g_assert(empty_list_0);

    g_assert_cmpint(qdict_size(empty_list_0), ==, 0);



    qobject_unref(src);

    qobject_unref(dst);

}
@@ -587,7 +607,7 @@ static void qdict_rename_keys_test(void) 


static void qdict_crumple_test_bad_inputs(void)

{

    QDict *src;

    QDict *src, *nested;

    Error *error = NULL;



    src = qdict_new();
@@ -614,7 +634,9 @@ static void qdict_crumple_test_bad_inputs(void) 


    src = qdict_new();

    /* The input should be flat, ie no dicts or lists */

    qdict_put(src, "rule.a", qdict_new());

    nested = qdict_new();

    qdict_put(nested, "x", qdict_new());

    qdict_put(src, "rule.a", nested);

    qdict_put_str(src, "rule.b", "allow");



    g_assert(qdict_crumple(src, &error) == NULL);