Re: [PATCH v13 11/42] virtio_ring: split: extract the logic of alloc state and extra

[Jason Wang <jasowang@xxxxxxxxxx>]

在 2022/7/26 15:21, Xuan Zhuo 写道:
> Separate the logic of creating desc_state, desc_extra, and subsequent
> patches will call it independently.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>


Acked-by: Jason Wang <jasowang@xxxxxxxxxx>


> ---
>   drivers/virtio/virtio_ring.c | 51 +++++++++++++++++++++++++-----------
>   1 file changed, 35 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> index 3817520371ee..6c24b33ea186 100644
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@ -212,6 +212,7 @@ static struct virtqueue *__vring_new_virtqueue(unsigned int index,
>   					       bool (*notify)(struct virtqueue *),
>   					       void (*callback)(struct virtqueue *),
>   					       const char *name);
> +static struct vring_desc_extra *vring_alloc_desc_extra(unsigned int num);
>   
>   /*
>    * Helpers.
> @@ -947,6 +948,32 @@ static void *virtqueue_detach_unused_buf_split(struct virtqueue *_vq)
>   	return NULL;
>   }
>   
> +static int vring_alloc_state_extra_split(struct vring_virtqueue_split *vring_split)
> +{
> +	struct vring_desc_state_split *state;
> +	struct vring_desc_extra *extra;
> +	u32 num = vring_split->vring.num;
> +
> +	state = kmalloc_array(num, sizeof(struct vring_desc_state_split), GFP_KERNEL);
> +	if (!state)
> +		goto err_state;
> +
> +	extra = vring_alloc_desc_extra(num);
> +	if (!extra)
> +		goto err_extra;
> +
> +	memset(state, 0, num * sizeof(struct vring_desc_state_split));
> +
> +	vring_split->desc_state = state;
> +	vring_split->desc_extra = extra;
> +	return 0;
> +
> +err_extra:
> +	kfree(state);
> +err_state:
> +	return -ENOMEM;
> +}
> +
>   static void vring_free_split(struct vring_virtqueue_split *vring_split,
>   			     struct virtio_device *vdev)
>   {
> @@ -2242,6 +2269,7 @@ static struct virtqueue *__vring_new_virtqueue(unsigned int index,
>   					       const char *name)
>   {
>   	struct vring_virtqueue *vq;
> +	int err;
>   
>   	if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED))
>   		return NULL;
> @@ -2282,17 +2310,14 @@ static struct virtqueue *__vring_new_virtqueue(unsigned int index,
>   					vq->split.avail_flags_shadow);
>   	}
>   
> -	vq->split.desc_state = kmalloc_array(vring_split->vring.num,
> -			sizeof(struct vring_desc_state_split), GFP_KERNEL);
> -	if (!vq->split.desc_state)
> -		goto err_state;
> -
> -	vq->split.desc_extra = vring_alloc_desc_extra(vring_split->vring.num);
> -	if (!vq->split.desc_extra)
> -		goto err_extra;
> +	err = vring_alloc_state_extra_split(vring_split);
> +	if (err) {
> +		kfree(vq);
> +		return NULL;
> +	}
>   
> -	memset(vq->split.desc_state, 0, vring_split->vring.num *
> -			sizeof(struct vring_desc_state_split));
> +	vq->split.desc_state = vring_split->desc_state;
> +	vq->split.desc_extra = vring_split->desc_extra;
>   
>   	virtqueue_init(vq, vring_split->vring.num);
>   
> @@ -2300,12 +2325,6 @@ static struct virtqueue *__vring_new_virtqueue(unsigned int index,
>   	list_add_tail(&vq->vq.list, &vdev->vqs);
>   	spin_unlock(&vdev->vqs_list_lock);
>   	return &vq->vq;
> -
> -err_extra:
> -	kfree(vq->split.desc_state);
> -err_state:
> -	kfree(vq);
> -	return NULL;
>   }
>   
>   struct virtqueue *vring_create_virtqueue(