The actual on-disk size of a file does not only depend on factors qemu
can control. Thus, we should not depend on this to determine whether a
file has indeed been fully allocated. Instead, use qemu-img map and hope
that if an area is referenced, it is indeed allocated, too.
Also, limit the supported image formats to raw and qcow2 because the
actual qemu-img map output may depend on the image format.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Tested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Passing -S 0 to qemu-img convert should result in all source data being
copied to the output, even if that source data is known to be 0. The
output image should therefore have exactly the same size on disk as an
image which we explicitly filled with data.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>