Re: [Qemu-devel] [PATCH v13 07/14] block/mirror: Improve progress report

[Kevin Wolf]

Am 22.10.2014 um 14:51 hat Max Reitz geschrieben:
> Instead of taking the total length of the block device as the block
> job's length, use the number of dirty sectors. The progress is now the
> number of sectors mirrored to the target block device. Note that this
> may result in the job's length increasing during operation, which is
> however in fact desirable.

More importantly, because it might surprise management tools, is that
the progress (as in offset/len) can actually decrease now.

I can't say whether that creates any problem, I'll rely on Eric's
Reviewed-by for that.

> Signed-off-by: Max Reitz <address@hidden>
> Reviewed-by: Eric Blake <address@hidden>
> ---
>  block/mirror.c | 34 ++++++++++++++++++++++------------
>  1 file changed, 22 insertions(+), 12 deletions(-)

> @@ -409,6 +416,12 @@ static void coroutine_fn mirror_run(void *opaque)
>          }
>  
>          cnt = bdrv_get_dirty_count(bs, s->dirty_bitmap);
> +        /* s->common.offset contains the number of bytes already processed so
> +         * far, cnt is the number of dirty sectors remaining and
> +         * s->sectors_in_flight is the number of sectors currently being
> +         * processed; together those are the current total operation length 
> */
> +        s->common.len = s->common.offset +
> +                        (cnt + s->sectors_in_flight) * BDRV_SECTOR_SIZE;

Isn't s->sectors_in_flight still contained in cnt? If I understand
correctly, sectors are only marked as clean at the same time as
s->sectors_in_flight is decremented again.

Kevin