Re: [Qemu-block] [PATCH 6/6] qcow2: Resize the cache upon image resizing

[Alberto Garcia]

On Sun 29 Jul 2018 11:27:44 PM CEST, Leonid Bloch wrote:
> The caches are now recalculated upon image resizing. This is done
> because the new default behavior of assigning a sufficient L2 cache to
> cover the entire image implies that the cache will still be sufficient
> after image resizing. To put a limit on the cache, the options
> cache-size and l2-cache-size can be used.
>
> Signed-off-by: Leonid Bloch <address@hidden>
> ---
>  block/qcow2.c | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/block/qcow2.c b/block/qcow2.c
> index 74f2cb10a4..06fac1bb8c 100644
> --- a/block/qcow2.c
> +++ b/block/qcow2.c
> @@ -3656,6 +3656,12 @@ static int coroutine_fn 
> qcow2_co_truncate(BlockDriverState *bs, int64_t offset,
>      }
>  
>      s->l1_vm_state_index = new_l1_size;
> +    /* Update cache sizes */
> +    QDict *options = qdict_clone_shallow(bs->options);
> +    ret = qcow2_update_options(bs, options, s->flags, errp);
> +    if (ret < 0) {
> +        goto fail;
> +    }

Perhaps this could be merged with the "Update total_sectors when
resizing" patch. When you put both changes together it is quite clear
why you need to update bs->total_sectors, and doing it is only necessary
if you want to do this afterwards.

Berto