Re: [PATCH 0/3] Check and repair duplicated clusters in parallels images

[Denis V. Lunev]

On 04.08.2022 17:01, Denis V. Lunev wrote:
> On 04.08.2022 16:51, alexander.ivanov@virtuozzo.com wrote:
> > From: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
> >
> > Parallels image file can be corrupted this way: two guest memory areas
> > refer to the same host memory area (duplicated offsets in BAT).
> > qemu-img check copies data from duplicated cluster to the new cluster 
> > and
> > writes new corresponding offset to BAT instead of duplicated one.
> >
> > Test 314 uses sample corrupted image parallels-2-duplicated-cluster.bz2.
> > Reading from duplicated offset and from original offset returns the same
> > data. After repairing changing either of these blocks of data
> > does not affect another one.
> >
> > Alexander Ivanov (3):
> >    parallels: Add checking and repairing duplicate offsets in BAT
> >    parallels: Let duplicates repairing pass without unwanted messages
> >    iotests, parallels: Add a test for duplicated clusters
> >
> >   block/parallels.c                             | 112 ++++++++++++++++--
> >   tests/qemu-iotests/314                        |  88 ++++++++++++++
> >   tests/qemu-iotests/314.out                    |  36 ++++++
> >   .../parallels-2-duplicated-cluster.bz2        | Bin 0 -> 148 bytes
> >   4 files changed, 227 insertions(+), 9 deletions(-)
> >   create mode 100755 tests/qemu-iotests/314
> >   create mode 100644 tests/qemu-iotests/314.out
> >   create mode 100644 
> > tests/qemu-iotests/sample_images/parallels-2-duplicated-cluster.bz2
> the series itself should be marked as v2 indicating that this is based on
> the original work of Natalia. Natalia should be in CC list.
>
> Also list of CC persons is too small, pls run
>
> iris ~/src/qemu $ ./scripts/get_maintainer.pl 
> 0001-parallels-Add-checking-and-repairing-duplicate-offse.patch
> Stefan Hajnoczi <stefanha@redhat.com> (supporter:parallels)
> "Denis V. Lunev" <den@openvz.org> (supporter:parallels)
> Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> 
> (supporter:parallels)
> Kevin Wolf <kwolf@redhat.com> (supporter:Block layer core)
> Hanna Reitz <hreitz@redhat.com> (supporter:Block layer core)
> qemu-block@nongnu.org (open list:parallels)
> qemu-devel@nongnu.org (open list:All patches CC here)
> iris ~/src/qemu $
>
> Additionally, you should list of changes from previous version
> at least in the main message.
and generic note, to think.

We will add more and more checks. Should we start thinking on a better
code structure in parallels_co_check, f.e. we could performs each
check in a separate loop in separate helper and calculate statisctics
once all checks were done.

This is just a quick note, but I think it worth to keep this in mind.

Den