block: BdrvChildRole.attach/detach() callbacks
Backing files are somewhat special compared to other kinds of children because they are attached and detached using bdrv_set_backing_hd() rather than the normal set of functions, which does a few more things like setting backing blockers, toggling the BDRV_O_NO_BACKING flag, setting parent_bs->backing_file, etc. These special features are a reason why change_parent_backing_link() can't handle backing files yet. With abstracting the additional features into .attach/.detach callbacks, we get a step closer to a function that can actually deal with this. Signed-off-by: NKevin Wolf <kwolf@redhat.com> Reviewed-by: NMax Reitz <mreitz@redhat.com> Acked-by: NFam Zheng <famz@redhat.com>
Showing
想要评论请 注册 或 登录