> From: Nicolin Chen <nicolinc@xxxxxxxxxx>
> Sent: Wednesday, February 8, 2023 5:18 AM
>
> +int iommu_group_replace_domain(struct iommu_group *group,
> + struct iommu_domain *new_domain)
> +{
> + int ret;
> +
> + if (!new_domain)
> + return -EINVAL;
> +
> + mutex_lock(&group->mutex);
> + ret = __iommu_group_set_domain(group, new_domain);
> + if (ret)
> + __iommu_group_set_domain(group, group->domain);
Just realize the error unwind is a nop given below:
__iommu_group_set_domain()
{
if (group->domain == new_domain)
return 0;
...
There was an attempt [1] to fix error unwind in iommu_attach_group(), by
temporarily set group->domain to NULL before calling set_domain().
Jason, I wonder why this recovering cannot be done in
__iommu_group_set_domain() directly, e.g.:
ret = __iommu_group_for_each_dev(group, new_domain,
iommu_group_do_attach_device);
if (ret) {
__iommu_group_for_each_dev(group, group->domain,
iommu_group_do_attach_device);
return ret;
}
group->domain = new_domain;
Thanks,
Kevin
[1] https://lore.kernel.org/linux-iommu/20230215052642.6016-1-vasant.hegde@xxxxxxx/
