@@ -1400,6 +1400,14 @@ static int bdrv_open_backing_reference_file(BlockDriverState *bs,
}
backing_hd = blk_bs(backing_blk);
+ /* Don't allow a disk use backing reference target */
+ ret = blk_attach_dev(backing_hd->blk, bs);
+ if (ret < 0) {
+ error_setg(errp, "backing_hd %s is used by the other device model",
+ backing_name);
+ goto free_exit;
+ }
+
/* Backing reference itself? */
if (backing_hd == bs || bdrv_find_overlay(backing_hd, bs)) {
error_setg(errp, "Backing reference itself");
@@ -2083,6 +2091,7 @@ void bdrv_close(BlockDriverState *bs)
if (backing_hd->backing_hd->job) {
block_job_cancel(backing_hd->backing_hd->job);
}
+ blk_detach_dev(backing_hd->backing_hd->blk, bs);
bdrv_set_backing_hd(backing_hd, NULL);
bdrv_unref(backing_hd->backing_hd);
}