Re: [Qemu-devel] [PATCH v4 11/21] mirror: Switch mirror_cow_align() to byte-based

[Kevin Wolf <kwolf@redhat.com>]

Am 05.07.2017 um 23:08 hat Eric Blake geschrieben:
> We are gradually converting to byte-based interfaces, as they are
> easier to reason about than sector-based.  Convert another internal
> function (no semantic change), and add mirror_clip_bytes() as a
> counterpart to mirror_clip_sectors().  Some of the conversion is
> a bit tricky, requiring temporaries to convert between units; it
> will be cleared up in a following patch.
> 
> Signed-off-by: Eric Blake <eblake@redhat.com>
> Reviewed-by: John Snow <jsnow@redhat.com>
> Reviewed-by: Jeff Cody <jcody@redhat.com>

> -    if (align_nb_sectors > max_sectors) {
> -        align_nb_sectors = max_sectors;
> +    if (align_bytes > max_bytes) {
> +        align_bytes = max_bytes;
>          if (need_cow) {
> -            align_nb_sectors = QEMU_ALIGN_DOWN(align_nb_sectors,
> -                                               s->target_cluster_size >>
> -                                               BDRV_SECTOR_BITS);
> +            align_bytes = QEMU_ALIGN_DOWN(align_bytes,
> +                                          s->target_cluster_size);

This would fit in a single line, if you have to respin for some reason.

Reviewed-by: Kevin Wolf <kwolf@redhat.com>