1 files changed, 35 insertions, 1 deletions

diff --git a/block.c b/block.c
index f377158c42..c5b887cec1 100644
--- a/block.c
+++ b/block.c
@@ -670,14 +670,48 @@ out:
 
 int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp)
 {
+    QemuOpts *protocol_opts;
     BlockDriver *drv;
+    QDict *qdict;
+    int ret;
 
     drv = bdrv_find_protocol(filename, true, errp);
     if (drv == NULL) {
         return -ENOENT;
     }
 
-    return bdrv_create(drv, filename, opts, errp);
+    if (!drv->create_opts) {
+        error_setg(errp, "Driver '%s' does not support image creation",
+                   drv->format_name);
+        return -ENOTSUP;
+    }
+
+    /*
+     * 'opts' contains a QemuOptsList with a combination of format and protocol
+     * default values.
+     *
+     * The format properly removes its options, but the default values remain
+     * in 'opts->list'.  So if the protocol has options with the same name
+     * (e.g. rbd has 'cluster_size' as qcow2), it will see the default values
+     * of the format, since for overlapping options, the format wins.
+     *
+     * To avoid this issue, lets convert QemuOpts to QDict, in this way we take
+     * only the set options, and then convert it back to QemuOpts, using the
+     * create_opts of the protocol. So the new QemuOpts, will contain only the
+     * protocol defaults.
+     */
+    qdict = qemu_opts_to_qdict(opts, NULL);
+    protocol_opts = qemu_opts_from_qdict(drv->create_opts, qdict, errp);
+    if (protocol_opts == NULL) {
+        ret = -EINVAL;
+        goto out;
+    }
+
+    ret = bdrv_create(drv, filename, protocol_opts, errp);
+out:
+    qemu_opts_del(protocol_opts);
+    qobject_unref(qdict);
+    return ret;
 }
 
 int coroutine_fn bdrv_co_delete_file(BlockDriverState *bs, Error **errp)