| Message ID | 1603390423-980205-13-git-send-email-andrey.shinkevich@virtuozzo.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Apply COR-filter to the block-stream permanently | expand |
diff --git a/block/copy-on-read.c b/block/copy-on-read.c index a2b180a..081e661 100644 --- a/block/copy-on-read.c +++ b/block/copy-on-read.c @@ -153,10 +153,14 @@ static int coroutine_fn cor_co_preadv_part(BlockDriverState *bs, } } - ret = bdrv_co_preadv_part(bs->file, offset, n, qiov, qiov_offset, - local_flags); - if (ret < 0) { - return ret; + /* Skip if neither read nor write are needed */ + if ((local_flags & (BDRV_REQ_PREFETCH | BDRV_REQ_COPY_ON_READ)) != + BDRV_REQ_PREFETCH) { + ret = bdrv_co_preadv_part(bs->file, offset, n, qiov, qiov_offset, + local_flags); + if (ret < 0) { + return ret; + } } offset += n;
If the flag BDRV_REQ_PREFETCH was set, skip idling read/write operations in COR-driver. It can be taken into account for the COR-algorithms optimization. That check is being made during the block stream job by the moment. Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> --- block/copy-on-read.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)