When refering to a backing file of an image via node name
bdrv_open_backing_file would add the 'driver' option to the option list
filling it with the backing format driver. This breaks construction of
the backing chain via -blockdev, as bdrv_open_inherit reports an error
if both 'reference' and 'options' are provided.
Signed-off-by: Peter Krempa <pkre...@redhat.com>
---
block.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/block.c b/block.c
index 46eb1728da..684cb018da 100644
--- a/block.c
+++ b/block.c
@@ -2245,7 +2245,8 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict
*parent_options,
goto free_exit;
}
- if (bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) {
+ if (!reference &&
+ bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) {
qdict_put_str(options, "driver", bs->backing_format);
}
--
2.14.1
