On Thu, Feb 02, 2017 at 05:25:15PM +0300, Denis V. Lunev wrote:
> From: Anton Nefedov <anton.nefe...@virtuozzo.com>
>
> If explicit zeroing out before mirroring is required for the target image,
> it moves the block job offset counter to EOF, then offset and len counters
> count the image size twice. There is no harm but stats are confusing,
> specifically the progress of the operation is always reported as 99% by
> management tools.
>
> The patch skips offset increase for the first "technical" pass over the
> image. This should not cause any further harm.
>
> Signed-off-by: Anton Nefedov <anton.nefe...@virtuozzo.com>
> Signed-off-by: Denis V. Lunev <d...@openvz.org>
> CC: Jeff Cody <jc...@redhat.com>
> CC: Kevin Wolf <kw...@redhat.com>
> CC: Max Reitz <mre...@redhat.com>
> CC: Eric Blake <ebl...@redhat.com>
> ---
> Changes from v1:
> - changed the approach - we do not allow to increase the offset rather then
> to move it back
> - description rewritten
> - kludges to tests are removed as not actually needed with this approach
>
> block/mirror.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/block/mirror.c b/block/mirror.c
> index 301ba92..f100f5d 100644
> --- a/block/mirror.c
> +++ b/block/mirror.c
> @@ -69,6 +69,7 @@ typedef struct MirrorBlockJob {
> bool waiting_for_io;
> int target_cluster_sectors;
> int max_iov;
> + bool initial_zeroing_ongoing;
> } MirrorBlockJob;
>
> typedef struct MirrorOp {
> @@ -117,9 +118,10 @@ static void mirror_iteration_done(MirrorOp *op, int ret)
> if (s->cow_bitmap) {
> bitmap_set(s->cow_bitmap, chunk_num, nb_chunks);
> }
> - s->common.offset += (uint64_t)op->nb_sectors * BDRV_SECTOR_SIZE;
> + if (!s->initial_zeroing_ongoing) {
> + s->common.offset += (uint64_t)op->nb_sectors * BDRV_SECTOR_SIZE;
> + }
> }
> -
> qemu_iovec_destroy(&op->qiov);
> g_free(op);
>
> @@ -566,6 +568,7 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob
> *s)
> return 0;
> }
>
> + s->initial_zeroing_ongoing = true;
> for (sector_num = 0; sector_num < end; ) {
> int nb_sectors = MIN(end - sector_num,
> QEMU_ALIGN_DOWN(INT_MAX, s->granularity) >>
> BDRV_SECTOR_BITS);
> @@ -573,6 +576,7 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob
> *s)
> mirror_throttle(s);
>
> if (block_job_is_cancelled(&s->common)) {
> + s->initial_zeroing_ongoing = false;
> return 0;
> }
>
> @@ -587,6 +591,7 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob
> *s)
> }
>
> mirror_wait_for_all_io(s);
> + s->initial_zeroing_ongoing = false;
> }
>
> /* First part, loop on the sectors and initialize the dirty bitmap. */
> --
> 2.7.4
>
Thanks,
Applied to my block branch:
git://github.com/codyprime/qemu-kvm-jtc.git block
-Jeff
