Re: [Qemu-devel] [PATCH v3 04/10] qcow2: Reuse refcount table in calculate_refcounts()

[Benoît Canet]

On Fri, Aug 22, 2014 at 06:31:38PM +0200, Max Reitz wrote:
> We will later call calculate_refcounts multiple times, so reuse the
> refcount table if possible.
> 
> Signed-off-by: Max Reitz <address@hidden>
> ---
>  block/qcow2-refcount.c | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
> index 2b728ef..babe6cb 100644
> --- a/block/qcow2-refcount.c
> +++ b/block/qcow2-refcount.c
> @@ -1584,10 +1584,12 @@ static int calculate_refcounts(BlockDriverState *bs, 
> BdrvCheckResult *res,
>      QCowSnapshot *sn;
>      int ret;
>  
> -    *refcount_table = g_try_new0(uint16_t, *nb_clusters);
> -    if (*nb_clusters && *refcount_table == NULL) {
> -        res->check_errors++;
> -        return -ENOMEM;
> +    if (!*refcount_table) {
> +        *refcount_table = g_try_new0(uint16_t, *nb_clusters);
> +        if (*nb_clusters && *refcount_table == NULL) {
> +            res->check_errors++;
> +            return -ENOMEM;
> +        }
>      }
>  
>      /* header */
> @@ -1694,7 +1696,7 @@ int qcow2_check_refcounts(BlockDriverState *bs, 
> BdrvCheckResult *res,
>  {
>      BDRVQcowState *s = bs->opaque;
>      int64_t size, highest_cluster, nb_clusters;
> -    uint16_t *refcount_table;
> +    uint16_t *refcount_table = NULL;
>      int ret;
>  
>      size = bdrv_getlength(bs->file);
> -- 
> 2.0.4
> 

Reviewed-by: Benoît Canet <address@hidden>