Re: [Qemu-devel] [Qemu-block] [PATCH 3/3] block: mirror - zero unallocated target sectors when zero init not present

[Stefan Hajnoczi]

On Sun, Sep 27, 2015 at 11:29:18PM -0400, Jeff Cody wrote:
> +    if (s->zero_cycle) {
> +        ret = bdrv_get_block_status(s->target, sector_num, nb_sectors, 
> &pnum);
> +        if (!(ret & BDRV_BLOCK_ZERO)) {
> +            bdrv_aio_write_zeroes(s->target, sector_num, op->nb_sectors,
> +                                  s->unmap ? BDRV_REQ_MAY_UNMAP : 0,
> +                                  mirror_write_complete, op);

mirror_write_complete will advance s->common.offset.  Won't the progress
be incorrect if we do that for both zeroing and regular mirroring?