On 10/28/19 4:10 PM, Jason Gunthorpe wrote:
> @@ -445,17 +438,9 @@ static void gntdev_vma_close(struct vm_area_struct *vma)
> struct gntdev_priv *priv = file->private_data;
>
> pr_debug("gntdev_vma_close %p\n", vma);
> - if (use_ptemod) {
> - /* It is possible that an mmu notifier could be running
> - * concurrently, so take priv->lock to ensure that the vma won't
> - * vanishing during the unmap_grant_pages call, since we will
> - * spin here until that completes. Such a concurrent call will
> - * not do any unmapping, since that has been done prior to
> - * closing the vma, but it may still iterate the unmap_ops list.
> - */
> - mutex_lock(&priv->lock);
> + if (use_ptemod && map->vma == vma) {
Is it possible for map->vma not to be equal to vma?
-boris
> + mmu_range_notifier_remove(&map->notifier);
> map->vma = NULL;
> - mutex_unlock(&priv->lock);
> }
> vma->vm_private_data = NULL;
> gntdev_put_map(priv, map);
>
