Add an option to limit copy-on-read operations to specified sub-chain
of backing-chain, to make copy-on-read filter useful for block-stream
job.
Suggested-by: Max Reitz <mreitz@redhat.com>
Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
[vsementsov: change subject, modified to freeze the chain,
do some fixes]
Message-Id: <20201216061703.70908-6-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
e4c8fddde7