On 29.09.2020 15:38, Andrey Shinkevich wrote:
This patch completes the series with the COR-filter insertion for block-stream operations. Adding the filter makes it possible for copied regions to be discarded in backing files during the block-stream job, what will reduce the disk overuse. The COR-filter insertion incurs changes in the iotests case 245:test_block_stream_4 that reopens the backing chain during a block-stream job. There are changes in the iotests #030 as well. The iotests case 030:test_stream_parallel was deleted due to multiple conflicts between the concurrent job operations over the same backing chain. The base backing node for one job is the top node for another job. It may change due to the filter node inserted into the backing chain while both jobs are running. Another issue is that the parts of the backing chain are being frozen by the running job and may not be changed by the concurrent job when needed. The concept of the parallel jobs with common nodes is considered vital no more. Signed-off-by: Andrey Shinkevich <andrey.shinkev...@virtuozzo.com> --- block/stream.c | 93 ++++++++++++++++++++++++++++++---------------- tests/qemu-iotests/030 | 51 +++---------------------- tests/qemu-iotests/030.out | 4 +- tests/qemu-iotests/141.out | 2 +- tests/qemu-iotests/245 | 19 +++++++--- 5 files changed, 83 insertions(+), 86 deletions(-) diff --git a/block/stream.c b/block/stream.c index fe2663f..240b3dc 100644 --- a/block/stream.c +++ b/block/stream.c @@ -17,8 +17,10 @@
One more change missed, as we use the COR-filter: @@ -47,8 +47,7 @@ static int coroutine_fn stream_populate(BlockBackend *blk, { assert(bytes < SIZE_MAX); - return blk_co_preadv(blk, offset, bytes, NULL, - BDRV_REQ_COPY_ON_READ | BDRV_REQ_PREFETCH); + return blk_co_preadv(blk, offset, bytes, NULL, 0); } Andrey