Re: [Qemu-devel] [RFC PATCH v2 20/23] qcow2: Cancel COW when overwritten

[Stefan Hajnoczi]

On Wed, Feb 13, 2013 at 02:22:10PM +0100, Kevin Wolf wrote:
> @@ -707,6 +710,16 @@ int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, 
> QCowL2Meta *m)
>      }
>  
>      /* Update L2 table. */
> +    qemu_co_mutex_unlock(&s->lock);
> +    qemu_co_rwlock_wrlock(&m->l2_writeback_lock);
> +    has_wr_lock = true;
> +    qemu_co_mutex_lock(&s->lock);
> +
> +    if (m->no_l2_update) {

QcowL2Meta now has a no_l2_update field.  A sign that we're abusing the
QcowL2Meta struct and really need a different abstraction?