We should not set overlap_bytes:
1. Don't worry: it is calculated by bdrv_mark_request_serialising() and
will be equal to or greater than bytes anyway.
2. If the request was already aligned up to some greater alignment,
than we may break things: we reduce overlap_bytes, and further
bdrv_mark_request_serialising() may not help, as it will not restore
old bigger alignment.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20201203222713.13507-2-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>