Hi all,
when you open an image [A] with a few more images on the backing chain
you get something like this:
[E] <- [D] <- [C] <- [B] <- [A]
Here you can go from [A] to [E] by following the bs->backing
pointer. At the same time each one of the backing files has an
'inherits_from' attribute pointing to their parent, so you can go from
[E] to [A] following the inherits_from pointer.
'inherits_from' is used on bdrv_reopen_queue_child() to decide if a
node's children must be reopened together with the parent and inherit
its options.
If some the intermediate nodes are removed (either by block-stream or
by block-commit) you end up with something like this:
[E] <- [A]
In this case we would expect [E] to inherit from [A], however its
inherits_from pointer is NULL and trying to change its options by
reopening [A] with backing.option=value fails.
This patch series fixes this. See each individual patch for more
details.
Regards,
Berto
Alberto Garcia (2):
block: Update BlockDriverState.inherits_from on bdrv_set_backing_hd()
block: Update BlockDriverState.inherits_from on
bdrv_drop_intermediate()
block.c | 37 ++++++++++++
tests/qemu-iotests/161 | 137 +++++++++++++++++++++++++++++++++++++++++++++
tests/qemu-iotests/161.out | 39 +++++++++++++
tests/qemu-iotests/group | 1 +
4 files changed, 214 insertions(+)
create mode 100755 tests/qemu-iotests/161
create mode 100644 tests/qemu-iotests/161.out
--
2.11.0
