Re: [PATCH 2/3] virtio: use put_device instead of kfree

[Cornelia Huck <cohuck@redhat.com>]

On Mon, 11 Dec 2017 23:55:26 +0800
weiping zhang <zhangweiping@didichuxing.com> wrote:

> don't free vp_vdev until vp_vdev.dev.release be called.

Same comment as for the virtio_pci patch.

> 
> Signed-off-by: weiping zhang <zhangweiping@didichuxing.com>
> ---
>  drivers/misc/mic/vop/vop_main.c | 16 +++++++++-------
>  1 file changed, 9 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/misc/mic/vop/vop_main.c b/drivers/misc/mic/vop/vop_main.c
> index a341938..8c716a0 100644
> --- a/drivers/misc/mic/vop/vop_main.c
> +++ b/drivers/misc/mic/vop/vop_main.c
> @@ -452,10 +452,12 @@ static irqreturn_t vop_virtio_intr_handler(int irq, void *data)
>  
>  static void vop_virtio_release_dev(struct device *_d)
>  {
> -	/*
> -	 * No need for a release method similar to virtio PCI.
> -	 * Provide an empty one to avoid getting a warning from core.
> -	 */
> +	struct virtio_device *vdev =
> +			container_of(_d, struct virtio_device, dev);
> +	struct _vop_vdev *vop_vdev =
> +			container_of(vdev, struct _vop_vdev, vdev);
> +
> +	kfree(vop_vdev);
>  }
>  
>  /*
> @@ -501,7 +503,9 @@ static int _vop_add_device(struct mic_device_desc __iomem *d,
>  		dev_err(_vop_dev(vdev),
>  			"Failed to register vop device %u type %u\n",
>  			offset, type);
> -		goto free_irq;
> +		vpdev->hw_ops->free_irq(vpdev, vdev->virtio_cookie, vdev);
> +		put_device(&vdev->vdev.dev);
> +		return ret;
>  	}
>  	writeq((u64)vdev, &vdev->dc->vdev);
>  	dev_dbg(_vop_dev(vdev), "%s: registered vop device %u type %u vdev %p\n",
> @@ -509,8 +513,6 @@ static int _vop_add_device(struct mic_device_desc __iomem *d,
>  
>  	return 0;
>  
> -free_irq:
> -	vpdev->hw_ops->free_irq(vpdev, vdev->virtio_cookie, vdev);
>  kfree:
>  	kfree(vdev);
>  	return ret;

BTW, the kfree(vdev) in _vop_remove_device() is also wrong (needs to be
a put_device() as well).