Re: [PATCH 6/6] virtio-blk: modernize sysfs attribute creation

Michael S. Tsirkin
2018-07-31T15:11:59Z

On Mon, Jul 30, 2018 at 09:12:27AM +0200, Hannes Reinecke wrote:
> Use new-style DEVICE_ATTR_RO/DEVICE_ATTR_RW to create the sysfs attributes
> and register the disk with default sysfs attribute groups.
>
> Signed-off-by: Hannes Reinecke <hare@suse.com>
> Cc: Michael Tsirkin <mst@redhat.com>
> Cc: Jason Wang <jasowang@redhat.com>

Acked-by: Michael S. Tsirkin <mst@redhat.com>

what's the right tree to merge this?

> ---
> drivers/block/virtio_blk.c | 68 ++++++++++++++++++++++++++--------------------
> 1 file changed, 39 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> index fe80560000a1..086c6bb12baa 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
> @@ -351,8 +351,8 @@ static int minor_to_index(int minor)
> return minor >> PART_BITS;
> }
>
> -static ssize_t virtblk_serial_show(struct device *dev,
> - struct device_attribute *attr, char *buf)
> +static ssize_t serial_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> {
> struct gendisk *disk = dev_to_disk(dev);
> int err;
> @@ -371,7 +371,7 @@ static ssize_t virtblk_serial_show(struct device *dev,
> return err;
> }
>
> -static DEVICE_ATTR(serial, 0444, virtblk_serial_show, NULL);
> +static DEVICE_ATTR_RO(serial);
>
> /* The queue's logical block size must be set before calling this */
> static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize)
> @@ -545,8 +545,8 @@ static const char *const virtblk_cache_types[] = {
> };
>
> static ssize_t
> -virtblk_cache_type_store(struct device *dev, struct device_attribute *attr,
> - const char *buf, size_t count)
> +cache_type_store(struct device *dev, struct device_attribute *attr,
> + const char *buf, size_t count)
> {
> struct gendisk *disk = dev_to_disk(dev);
> struct virtio_blk *vblk = disk->private_data;
> @@ -564,8 +564,7 @@ virtblk_cache_type_store(struct device *dev, struct device_attribute *attr,
> }
>
> static ssize_t
> -virtblk_cache_type_show(struct device *dev, struct device_attribute *attr,
> - char *buf)
> +cache_type_show(struct device *dev, struct device_attribute *attr, char *buf)
> {
> struct gendisk *disk = dev_to_disk(dev);
> struct virtio_blk *vblk = disk->private_data;
> @@ -575,12 +574,38 @@ virtblk_cache_type_show(struct device *dev, struct device_attribute *attr,
> return snprintf(buf, 40, "%s\n", virtblk_cache_types[writeback]);
> }
>
> -static const struct device_attribute dev_attr_cache_type_ro =
> - __ATTR(cache_type, 0444,
> - virtblk_cache_type_show, NULL);
> -static const struct device_attribute dev_attr_cache_type_rw =
> - __ATTR(cache_type, 0644,
> - virtblk_cache_type_show, virtblk_cache_type_store);
> +static DEVICE_ATTR_RW(cache_type);
> +
> +static struct attribute *virtblk_attrs[] = {
> + &dev_attr_serial.attr,
> + &dev_attr_cache_type.attr,
> + NULL,
> +};
> +
> +static umode_t virtblk_attrs_are_visible(struct kobject *kobj,
> + struct attribute *a, int n)
> +{
> + struct device *dev = container_of(kobj, struct device, kobj);
> + struct gendisk *disk = dev_to_disk(dev);
> + struct virtio_blk *vblk = disk->private_data;
> + struct virtio_device *vdev = vblk->vdev;
> +
> + if (a == &dev_attr_cache_type.attr &&
> + !virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE))
> + return S_IRUGO;
> +
> + return a->mode;
> +}
> +
> +static const struct attribute_group virtblk_attr_group = {
> + .attrs = virtblk_attrs,
> + .is_visible = virtblk_attrs_are_visible,
> +};
> +
> +static const struct attribute_group *virtblk_attr_groups[] = {
> + &virtblk_attr_group,
> + NULL,
> +};
>
> static int virtblk_init_request(struct blk_mq_tag_set *set, struct request *rq,
> unsigned int hctx_idx, unsigned int numa_node)
> @@ -780,24 +805,9 @@ static int virtblk_probe(struct virtio_device *vdev)
> virtblk_update_capacity(vblk, false);
> virtio_device_ready(vdev);
>
> - device_add_disk(&vdev->dev, vblk->disk, NULL);
> - err = device_create_file(disk_to_dev(vblk->disk), &dev_attr_serial);
> - if (err)
> - goto out_del_disk;
> -
> - if (virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE))
> - err = device_create_file(disk_to_dev(vblk->disk),
> - &dev_attr_cache_type_rw);
> - else
> - err = device_create_file(disk_to_dev(vblk->disk),
> - &dev_attr_cache_type_ro);
> - if (err)
> - goto out_del_disk;
> + device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups);
> return 0;
>
> -out_del_disk:
> - del_gendisk(vblk->disk);
> - blk_cleanup_queue(vblk->disk->queue);
> out_free_tags:
> blk_mq_free_tag_set(&vblk->tag_set);
> out_put_disk:
> --
> 2.12.3