linux-kernel - Re: [PATCH v10 04/19] vfio: Common function to increment container

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Date:   Wed, 02 Nov 2016 19:34:22 +0800
From:   Jike Song <jike.song@...el.com>
To:     Kirti Wankhede <kwankhede@...dia.com>
CC:     alex.williamson@...hat.com, pbonzini@...hat.com, kraxel@...hat.com,
        cjia@...dia.com, qemu-devel@...gnu.org, kvm@...r.kernel.org,
        kevin.tian@...el.com, bjsdjshi@...ux.vnet.ibm.com,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v10 04/19] vfio: Common function to increment container_users

On 10/27/2016 05:29 AM, Kirti Wankhede wrote:
> This change rearrange functions to have common function to increment
> container_users
> 
> Signed-off-by: Kirti Wankhede <kwankhede@...dia.com>
> Signed-off-by: Neo Jia <cjia@...dia.com>
> Change-Id: I8bdeb352bc8439b107ffd519480fd4dc238677f2
> ---
>  drivers/vfio/vfio.c | 34 +++++++++++++++++++++-------------
>  1 file changed, 21 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
> index 23bc86c1d05d..2e83bdf007fe 100644
> --- a/drivers/vfio/vfio.c
> +++ b/drivers/vfio/vfio.c
> @@ -1385,6 +1385,23 @@ static bool vfio_group_viable(struct vfio_group *group)
>  					 group, vfio_dev_viable) == 0);
>  }
>  
> +static int vfio_group_add_container_user(struct vfio_group *group)
> +{
> +	if (!atomic_inc_not_zero(&group->container_users))
> +		return -EINVAL;
> +
> +	if (group->noiommu) {
> +		atomic_dec(&group->container_users);
> +		return -EPERM;
> +	}

trivial: a blank line here

> +	if (!group->container->iommu_driver || !vfio_group_viable(group)) {
> +		atomic_dec(&group->container_users);
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
>  static const struct file_operations vfio_device_fops;
>  
>  static int vfio_group_get_device_fd(struct vfio_group *group, char *buf)
> @@ -1694,23 +1711,14 @@ static const struct file_operations vfio_device_fops = {
>  struct vfio_group *vfio_group_get_external_user(struct file *filep)
>  {
>  	struct vfio_group *group = filep->private_data;
> +	int ret;
>  
>  	if (filep->f_op != &vfio_group_fops)
>  		return ERR_PTR(-EINVAL);
>  
> -	if (!atomic_inc_not_zero(&group->container_users))
> -		return ERR_PTR(-EINVAL);
> -
> -	if (group->noiommu) {
> -		atomic_dec(&group->container_users);
> -		return ERR_PTR(-EPERM);
> -	}
> -
> -	if (!group->container->iommu_driver ||
> -			!vfio_group_viable(group)) {
> -		atomic_dec(&group->container_users);
> -		return ERR_PTR(-EINVAL);
> -	}
> +	ret = vfio_group_add_container_user(group);
> +	if (ret)
> +		return ERR_PTR(ret);
>  
>  	vfio_group_get(group);
>  

Reviewed-by: Jike Song <jike.song@...el.com>

--
Thanks,
Jike