bdrv_get_device_name() will be an empty string with modern management tools that don't use -drive. Use bdrv_get_device_or_node_name() instead so that the node name is used if the BlockBackend is anonymous.
While at it, start with upper case to make the message consistent with the rest of the function. Signed-off-by: Kevin Wolf <kw...@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> Reviewed-by: Alberto Garcia <be...@igalia.com> --- block/backup.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/block/backup.c b/block/backup.c index a7a7dcaf4c..c4c3b8cd46 100644 --- a/block/backup.c +++ b/block/backup.c @@ -400,8 +400,8 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs, len = bdrv_getlength(bs); if (len < 0) { - error_setg_errno(errp, -len, "unable to get length for '%s'", - bdrv_get_device_name(bs)); + error_setg_errno(errp, -len, "Unable to get length for '%s'", + bdrv_get_device_or_node_name(bs)); goto error; } -- 2.25.3