Re: [PATCH v2 3/6] iommu: Same critical region for device release and removal

[Jason Gunthorpe]

On Fri, Feb 17, 2023 at 05:47:33PM +0800, Lu Baolu wrote:
> In a non-driver context, it is crucial to ensure the consistency of a
> device's iommu ops. Otherwise, it may result in a situation where a
> device is released but it's iommu ops are still used.
> 
> Put the ops->release_device and __iommu_group_remove_device() in a some
> group->mutext critical region, so that, as long as group->mutex is held
> and the device is in its group's device list, its iommu ops are always
> consistent.
> 
> Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> ---
>  drivers/iommu/iommu.c | 15 +++++++++++++--
>  1 file changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index 6247883991e2..093692308b80 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -101,6 +101,10 @@ static int iommu_create_device_direct_mappings(struct iommu_group *group,
>  static struct iommu_group *iommu_group_get_for_dev(struct device *dev);
>  static ssize_t iommu_group_store_type(struct iommu_group *group,
>  				      const char *buf, size_t count);
> +static struct group_device *
> +__iommu_group_remove_device(struct iommu_group *group, struct device *dev);
> +static void __iommu_group_release_device(struct iommu_group *group,
> +					 struct group_device *grp_dev);

Seems like a hunk is missing from this patch?

Jason