This patch series adds the functionality to change the backing file of existing images. This includes simple renaming of a backing file without converting the COW image as well as safe rebasing onto a different backing file that has some changes compared to the current backing file.
Kevin Wolf (3): block: Introduce BDRV_O_NO_BACKING block: Add bdrv_change_backing_file qemu-img rebase block.c | 24 ++++++- block.h | 3 + block/qcow2.c | 82 +++++++++++++++++++++++ block_int.h | 3 + qemu-img-cmds.hx | 6 ++ qemu-img.c | 192 +++++++++++++++++++++++++++++++++++++++++++++++++++++- 6 files changed, 307 insertions(+), 3 deletions(-)