Re: [Qemu-devel] [PATCH v2 4/6] qemu-img: Enable progress output for commit

[Kevin Wolf <kwolf@redhat.com>]

Am 08.04.2014 um 14:50 hat Max Reitz geschrieben:
> Implement progress output for the commit command by querying the
> progress of the block job.
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> Reviewed-by: Eric Blake <eblake@redhat.com>
> ---
>  qemu-img-cmds.hx |  4 ++--
>  qemu-img.c       | 33 +++++++++++++++++++++++++++++++--
>  qemu-img.texi    |  2 +-
>  3 files changed, 34 insertions(+), 5 deletions(-)
> 
> diff --git a/qemu-img-cmds.hx b/qemu-img-cmds.hx
> index d029609..8bc55cd 100644
> --- a/qemu-img-cmds.hx
> +++ b/qemu-img-cmds.hx
> @@ -22,9 +22,9 @@ STEXI
>  ETEXI
>  
>  DEF("commit", img_commit,
> -    "commit [-q] [-f fmt] [-t cache] filename")
> +    "commit [-q] [-f fmt] [-t cache] [-p] filename")
>  STEXI
> -@item commit [-q] [-f @var{fmt}] [-t @var{cache}] @var{filename}
> +@item commit [-q] [-f @var{fmt}] [-t @var{cache}] [-p] @var{filename}
>  ETEXI
>  
>  DEF("compare", img_compare,
> diff --git a/qemu-img.c b/qemu-img.c
> index e86911f..0a9eff7 100644
> --- a/qemu-img.c
> +++ b/qemu-img.c
> @@ -690,12 +690,27 @@ static void dummy_block_job_cb(void *opaque, int ret)
>  static void run_block_job(BlockJob *job, Error **errp)
>  {
>      BlockJobInfo *info;
> +    uint64_t mod_offset = 0;
>  
>      do {
>          aio_poll(qemu_get_aio_context(), true);
>  
>          info = block_job_query(job);
>  
> +        if (info->offset) {
> +            if (!mod_offset) {

On a fully populated image this doesn't look entirely right. I think the
first 2 MB (or whatever the buffer size is) will be disregarded in the
calculation, even though they are real work that is done.

> +                /* Some block jobs (at least "commit") will only work on a
> +                 * subset of the image file and therefore basically skip many
> +                 * sectors at the start (processing them apparently
> +                 * instantaneously). These sectors should be ignored when
> +                 * calculating the progress. */
> +                mod_offset = info->offset;
> +            }
> +
> +            qemu_progress_print((float)(info->offset - mod_offset) /
> +                                (info->len - mod_offset) * 100.f, 0);
> +        }
> +
>          if (!info->busy && info->offset < info->len) {
>              block_job_resume(job);
>          }

Kevin