Re: [PATCH 3/7] block/rbd: use stored image_size in qemu_rbd_getlength

[Jason Dillaman]

On Sun, Dec 27, 2020 at 11:42 AM Peter Lieven <pl@kamp.de> wrote:
>
> Signed-off-by: Peter Lieven <pl@kamp.de>
> ---
>  block/rbd.c | 10 +---------
>  1 file changed, 1 insertion(+), 9 deletions(-)
>
> diff --git a/block/rbd.c b/block/rbd.c
> index bc8cf8af9b..a2da70e37f 100644
> --- a/block/rbd.c
> +++ b/block/rbd.c
> @@ -956,15 +956,7 @@ static int qemu_rbd_getinfo(BlockDriverState *bs, 
> BlockDriverInfo *bdi)
>  static int64_t qemu_rbd_getlength(BlockDriverState *bs)
>  {
>      BDRVRBDState *s = bs->opaque;
> -    rbd_image_info_t info;
> -    int r;
> -
> -    r = rbd_stat(s->image, &info, sizeof(info));
> -    if (r < 0) {
> -        return r;
> -    }
> -
> -    return info.size;
> +    return s->image_size;
>  }
>
>  static int coroutine_fn qemu_rbd_co_truncate(BlockDriverState *bs,
> --
> 2.17.1

An RBD image can technically change size dynamically while in-use. The
original code would provide the most up-to-date length but this
version will always return the size of the image when it was opened.


--
Jason