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Message-ID: <2ed84b0f-5d60-919f-06a4-a5ede2f98ce5@redhat.com>
Date:   Wed, 7 Sep 2022 21:35:52 +0200
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Reply-To: eric.auger@redhat.com
Subject: Re: [PATCH v2 14/15] vfio: Rename vfio_device_put() and
 vfio_device_try_get()
Content-Language: en-US
To:     Kevin Tian <kevin.tian@intel.com>,
        Zhenyu Wang <zhenyuw@linux.intel.com>,
        Zhi Wang <zhi.a.wang@intel.com>,
        Jani Nikula <jani.nikula@linux.intel.com>,
        Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@intel.com>,
        Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Eric Farman <farman@linux.ibm.com>,
        Matthew Rosato <mjrosato@linux.ibm.com>,
        Halil Pasic <pasic@linux.ibm.com>,
        Vineeth Vijayan <vneethv@linux.ibm.com>,
        Peter Oberparleiter <oberpar@linux.ibm.com>,
        Heiko Carstens <hca@linux.ibm.com>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Alexander Gordeev <agordeev@linux.ibm.com>,
        Christian Borntraeger <borntraeger@linux.ibm.com>,
        Sven Schnelle <svens@linux.ibm.com>,
        Tony Krowiak <akrowiak@linux.ibm.com>,
        Jason Herne <jjherne@linux.ibm.com>,
        Harald Freudenberger <freude@linux.ibm.com>,
        Diana Craciun <diana.craciun@oss.nxp.com>,
        Alex Williamson <alex.williamson@redhat.com>,
        Cornelia Huck <cohuck@redhat.com>,
        Longfang Liu <liulongfang@huawei.com>,
        Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>,
        Jason Gunthorpe <jgg@ziepe.ca>,
        Yishai Hadas <yishaih@nvidia.com>,
        Kirti Wankhede <kwankhede@nvidia.com>,
        Leon Romanovsky <leon@kernel.org>,
        Abhishek Sahu <abhsahu@nvidia.com>,
        intel-gvt-dev@lists.freedesktop.org,
        intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org,
        kvm@vger.kernel.org
Cc:     Yi Liu <yi.l.liu@intel.com>
References: <20220901143747.32858-1-kevin.tian@intel.com>
 <20220901143747.32858-15-kevin.tian@intel.com>
From:   Eric Auger <eric.auger@redhat.com>
In-Reply-To: <20220901143747.32858-15-kevin.tian@intel.com>
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On 9/1/22 16:37, Kevin Tian wrote:
> With the addition of vfio_put_device() now the names become confusing.
>
> vfio_put_device() is clear from object life cycle p.o.v given kref.
>
> vfio_device_put()/vfio_device_try_get() are helpers for tracking
> users on a registered device.
>
> Now rename them:
>
>  - vfio_device_put() -> vfio_device_put_registration()
>  - vfio_device_try_get() -> vfio_device_try_get_registration()
>
> Signed-off-by: Kevin Tian <kevin.tian@intel.com>
> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>

Eric
> ---
>  drivers/vfio/vfio_main.c | 17 +++++++++--------
>  1 file changed, 9 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
> index 957d9f286550..bfa675d314ab 100644
> --- a/drivers/vfio/vfio_main.c
> +++ b/drivers/vfio/vfio_main.c
> @@ -451,13 +451,13 @@ static void vfio_group_get(struct vfio_group *group)
>   * Device objects - create, release, get, put, search
>   */
>  /* Device reference always implies a group reference */
> -static void vfio_device_put(struct vfio_device *device)
> +static void vfio_device_put_registration(struct vfio_device *device)
>  {
>  	if (refcount_dec_and_test(&device->refcount))
>  		complete(&device->comp);
>  }
>  
> -static bool vfio_device_try_get(struct vfio_device *device)
> +static bool vfio_device_try_get_registration(struct vfio_device *device)
>  {
>  	return refcount_inc_not_zero(&device->refcount);
>  }
> @@ -469,7 +469,8 @@ static struct vfio_device *vfio_group_get_device(struct vfio_group *group,
>  
>  	mutex_lock(&group->device_lock);
>  	list_for_each_entry(device, &group->device_list, group_next) {
> -		if (device->dev == dev && vfio_device_try_get(device)) {
> +		if (device->dev == dev &&
> +		    vfio_device_try_get_registration(device)) {
>  			mutex_unlock(&group->device_lock);
>  			return device;
>  		}
> @@ -671,7 +672,7 @@ static int __vfio_register_dev(struct vfio_device *device,
>  	if (existing_device) {
>  		dev_WARN(device->dev, "Device already exists on group %d\n",
>  			 iommu_group_id(group->iommu_group));
> -		vfio_device_put(existing_device);
> +		vfio_device_put_registration(existing_device);
>  		if (group->type == VFIO_NO_IOMMU ||
>  		    group->type == VFIO_EMULATED_IOMMU)
>  			iommu_group_remove_device(device->dev);
> @@ -730,7 +731,7 @@ static struct vfio_device *vfio_device_get_from_name(struct vfio_group *group,
>  			ret = !strcmp(dev_name(it->dev), buf);
>  		}
>  
> -		if (ret && vfio_device_try_get(it)) {
> +		if (ret && vfio_device_try_get_registration(it)) {
>  			device = it;
>  			break;
>  		}
> @@ -750,7 +751,7 @@ void vfio_unregister_group_dev(struct vfio_device *device)
>  	bool interrupted = false;
>  	long rc;
>  
> -	vfio_device_put(device);
> +	vfio_device_put_registration(device);
>  	rc = try_wait_for_completion(&device->comp);
>  	while (rc <= 0) {
>  		if (device->ops->request)
> @@ -1286,7 +1287,7 @@ static int vfio_group_get_device_fd(struct vfio_group *group, char *buf)
>  err_put_fdno:
>  	put_unused_fd(fdno);
>  err_put_device:
> -	vfio_device_put(device);
> +	vfio_device_put_registration(device);
>  	return ret;
>  }
>  
> @@ -1461,7 +1462,7 @@ static int vfio_device_fops_release(struct inode *inode, struct file *filep)
>  
>  	vfio_device_unassign_container(device);
>  
> -	vfio_device_put(device);
> +	vfio_device_put_registration(device);
>  
>  	return 0;
>  }