Re: [Qemu-devel] [PATCH v2 5/5] iotests: Add test 197 for covering copy-on-read

[Stefan Hajnoczi <stefanha@redhat.com>]

On Tue, Oct 03, 2017 at 08:43:47PM -0500, Eric Blake wrote:
> Add a test for qcow2 copy-on-read behavior, including exposure
> for the just-fixed bugs.
> 
> The copy-on-read behavior is always to a qcow2 image, but the
> test is careful to allow running with most image protocol/format
> combos as the backing file being copied from (luks being the
> exception, as it is harder to pass the right secret to all the
> right places).  In fact, for './check nbd', this appears to be
> the first time we've had a qcow2 image wrapping NBD, requiring
> an additional line in _filter_img_create to match the similar
> line in _filter_img_info.
> 
> Invoking blkdebug to prove we don't write too much took some
> effort to get working; and it requires that $TEST_WRAP (based
> on $TEST_DIR) not be subject to word splitting.  We may decide
> later to have the entire iotests suite use relative rather than
> absolute names, to avoid problems inherited by the absolute
> name of $PWD or $TEST_DIR, at which point the sanity check in
> this commit could be simplified.
> 
> Signed-off-by: Eric Blake <eblake@redhat.com>
> 
> ---
> v2: test 0-length query [Kevin], sanity check TEST_DIR [Jeff]
> 
> I only tested with -raw, -qcow2, -qed, and -nbd. I won't be
> surprised if the test fails in some other setup...
> ---
>  tests/qemu-iotests/common.filter |   1 +
>  tests/qemu-iotests/197           | 102 +++++++++++++++++++++++++++++++++++++++
>  tests/qemu-iotests/197.out       |  26 ++++++++++
>  tests/qemu-iotests/group         |   1 +
>  4 files changed, 130 insertions(+)
>  create mode 100755 tests/qemu-iotests/197
>  create mode 100644 tests/qemu-iotests/197.out

Aside from the 2GB request issue:

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>