On Wed, Jul 26, 2017 at 03:32:23PM +0100, Stefan Hajnoczi wrote:
> The message printed on disk resize is incorrect.  The following is
> printed when resizing to 2 GiB:
> 
>   $ truncate -s 1G test.img
>   $ qemu -device virtio-blk-pci,logical_block_size=4096,...
>   (qemu) block_resize drive1 2G
> 
>   virtio_blk virtio0: new size: 4194304 4096-byte logical blocks (17.2 
> GB/16.0 GiB)
> 
> The virtio_blk capacity config field is in 512-byte sector units
> regardless of logical_block_size as per the VIRTIO specification.
> Therefore the message should read:
> 
>   virtio_blk virtio0: new size: 524288 4096-byte logical blocks (2.15 GB/2.0 
> GiB)
> 
> Note that this only affects the printed message.  Thankfully the actual
> block device has the correct size because the block layer expects
> capacity in sectors.
> 
> Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
> ---
>  drivers/block/virtio_blk.c | 16 ++++++++++------
>  1 file changed, 10 insertions(+), 6 deletions(-)

Ping?

> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> index 4e02aa5fdac0..69a2d1748743 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
> @@ -381,6 +381,7 @@ static void virtblk_config_changed_work(struct 
> work_struct *work)
>       struct request_queue *q = vblk->disk->queue;
>       char cap_str_2[10], cap_str_10[10];
>       char *envp[] = { "RESIZE=1", NULL };
> +     unsigned long long nblocks;
>       u64 capacity;
>  
>       /* Host must always specify the capacity. */
> @@ -393,16 +394,19 @@ static void virtblk_config_changed_work(struct 
> work_struct *work)
>               capacity = (sector_t)-1;
>       }
>  
> -     string_get_size(capacity, queue_logical_block_size(q),
> +     nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9);
> +
> +     string_get_size(nblocks, queue_logical_block_size(q),
>                       STRING_UNITS_2, cap_str_2, sizeof(cap_str_2));
> -     string_get_size(capacity, queue_logical_block_size(q),
> +     string_get_size(nblocks, queue_logical_block_size(q),
>                       STRING_UNITS_10, cap_str_10, sizeof(cap_str_10));
>  
>       dev_notice(&vdev->dev,
> -               "new size: %llu %d-byte logical blocks (%s/%s)\n",
> -               (unsigned long long)capacity,
> -               queue_logical_block_size(q),
> -               cap_str_10, cap_str_2);
> +                "new size: %llu %d-byte logical blocks (%s/%s)\n",
> +                nblocks,
> +                queue_logical_block_size(q),
> +                cap_str_10,
> +                cap_str_2);
>  
>       set_capacity(vblk->disk, capacity);
>       revalidate_disk(vblk->disk);
> -- 
> 2.13.3
> 

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