The current version of the zero cluster expansion uses the guest disk size for determining the size of the expanded_clusters bitmap, however, it is addressed using host offsets. This leads to an assertion failing if the host image size exceeds the guest disk size. This is fixed by using the host image size instead for allocating the bitmap.
This however uncovers another problem: If the host image is growable, it may grow during the zero cluster expansion due to cluster allocations. If this happens, the bitmap has to be resized accordingly. Max Reitz (2): qcow2: Correct bitmap size in zero expansion qemu-iotests: Preallocated zero clusters in 061 block/qcow2-cluster.c | 38 +++++++++++++++++++++++++++----------- tests/qemu-iotests/061 | 9 +++++++++ tests/qemu-iotests/061.out | 11 +++++++++++ 3 files changed, 47 insertions(+), 11 deletions(-) -- 1.8.3.1