This series allows libvirt to fix a regression that its switch from drive-mirror to blockdev-mirror caused: It currently requires that the backing chain of the target image is already available when the mirror operation is started.
In reality, the backing chain may only be copied while the operation is in progress, so the backing file of the target image needs to stay disabled until the operation completes and should be attached only at that point. Without this series, we don't have a supported API to attach the backing file at that later point. Kevin Wolf (4): block: Make bdrv_get_cumulative_perm() public block: Relax restrictions for blockdev-snapshot iotests: Fix run_job() with use_log=False iotests: Test mirror with temporarily disabled target backing file include/block/block_int.h | 3 ++ block.c | 6 ++-- blockdev.c | 14 +++++---- tests/qemu-iotests/iotests.py | 5 +++- tests/qemu-iotests/155 | 54 +++++++++++++++++++++++++++++++---- tests/qemu-iotests/155.out | 4 +-- 6 files changed, 68 insertions(+), 18 deletions(-) -- 2.20.1
