Comment 1 for bug 1850000

Current trunk still displays the problem.

A git bisection between 4.0.0 and 4.1.0 revealed:

b6c246942b14d3e0dec46a6c5868ed84e7dbea19 is the first bad commit
commit b6c246942b14d3e0dec46a6c5868ed84e7dbea19
Author: Alberto Garcia <email address hidden>
Date: Fri May 10 19:22:54 2019 +0300

    qcow2: Define and use QCOW2_COMPRESSED_SECTOR_SIZE

    When an L2 table entry points to a compressed cluster the space used
    by the data is specified in 512-byte sectors. This size is independent
    from BDRV_SECTOR_SIZE and is specific to the qcow2 file format.

    The QCOW2_COMPRESSED_SECTOR_SIZE constant defined in this patch makes
    this explicit.

    Signed-off-by: Alberto Garcia <email address hidden>
    Signed-off-by: Kevin Wolf <email address hidden>

 block/qcow2-cluster.c | 5 +++--
 block/qcow2-refcount.c | 25 ++++++++++++++-----------
 block/qcow2.c | 3 ++-
 block/qcow2.h | 4 ++++
 4 files changed, 23 insertions(+), 14 deletions(-)