On Sun, Oct 02, 2022 at 06:44:17PM +0300, Max Gurtovoy
wrote:> Divide the extremely long probe function to small meaningful functions.
> This makes the code more readably and easy to maintain.
>
> Signed-off-by: Max Gurtovoy <mgurtovoy at nvidia.com>
This is subjective ... pls CC some reviewers. If Stefan or Paolo
ack this I will merge.
> ---
> drivers/block/virtio_blk.c | 227 +++++++++++++++++++++----------------
> 1 file changed, 131 insertions(+), 96 deletions(-)
>
> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> index 30255fcaf181..bdd44069bf6f 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
> @@ -882,28 +882,13 @@ static const struct blk_mq_ops virtio_mq_ops = {
> static unsigned int virtblk_queue_depth;
> module_param_named(queue_depth, virtblk_queue_depth, uint, 0444);
>
> -static int virtblk_probe(struct virtio_device *vdev)
> +static int virtblk_q_limits_set(struct virtio_device *vdev,
> + struct request_queue *q)
> {
> - struct virtio_blk *vblk;
> - struct request_queue *q;
> - int err, index;
> -
> - u32 v, blk_size, max_size, sg_elems, opt_io_size;
> - u16 min_io_size;
> u8 physical_block_exp, alignment_offset;
> - unsigned int queue_depth;
> -
> - if (!vdev->config->get) {
> - dev_err(&vdev->dev, "%s failure: config access
disabled\n",
> - __func__);
> - return -EINVAL;
> - }
> -
> - err = ida_simple_get(&vd_index_ida, 0, minor_to_index(1 <<
MINORBITS),
> - GFP_KERNEL);
> - if (err < 0)
> - goto out;
> - index = err;
> + u16 min_io_size;
> + u32 v, blk_size, max_size, sg_elems, opt_io_size;
> + int err;
>
> /* We need to know how many segments before we allocate. */
> err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX,
> @@ -917,73 +902,6 @@ static int virtblk_probe(struct virtio_device *vdev)
> /* Prevent integer overflows and honor max vq size */
> sg_elems = min_t(u32, sg_elems, VIRTIO_BLK_MAX_SG_ELEMS - 2);
>
> - vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
> - if (!vblk) {
> - err = -ENOMEM;
> - goto out_free_index;
> - }
> -
> - mutex_init(&vblk->vdev_mutex);
> -
> - vblk->vdev = vdev;
> -
> - INIT_WORK(&vblk->config_work, virtblk_config_changed_work);
> -
> - err = init_vq(vblk);
> - if (err)
> - goto out_free_vblk;
> -
> - /* Default queue sizing is to fill the ring. */
> - if (!virtblk_queue_depth) {
> - queue_depth = vblk->vqs[0].vq->num_free;
> - /* ... but without indirect descs, we use 2 descs per req */
> - if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC))
> - queue_depth /= 2;
> - } else {
> - queue_depth = virtblk_queue_depth;
> - }
> -
> - memset(&vblk->tag_set, 0, sizeof(vblk->tag_set));
> - vblk->tag_set.ops = &virtio_mq_ops;
> - vblk->tag_set.queue_depth = queue_depth;
> - vblk->tag_set.numa_node = NUMA_NO_NODE;
> - vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
> - vblk->tag_set.cmd_size > - sizeof(struct virtblk_req) +
> - sizeof(struct scatterlist) * VIRTIO_BLK_INLINE_SG_CNT;
> - vblk->tag_set.driver_data = vblk;
> - vblk->tag_set.nr_hw_queues = vblk->num_vqs;
> - vblk->tag_set.nr_maps = 1;
> - if (vblk->io_queues[HCTX_TYPE_POLL])
> - vblk->tag_set.nr_maps = 3;
> -
> - err = blk_mq_alloc_tag_set(&vblk->tag_set);
> - if (err)
> - goto out_free_vq;
> -
> - vblk->disk = blk_mq_alloc_disk(&vblk->tag_set, vblk);
> - if (IS_ERR(vblk->disk)) {
> - err = PTR_ERR(vblk->disk);
> - goto out_free_tags;
> - }
> - q = vblk->disk->queue;
> -
> - virtblk_name_format("vd", index, vblk->disk->disk_name,
DISK_NAME_LEN);
> -
> - vblk->disk->major = major;
> - vblk->disk->first_minor = index_to_minor(index);
> - vblk->disk->minors = 1 << PART_BITS;
> - vblk->disk->private_data = vblk;
> - vblk->disk->fops = &virtblk_fops;
> - vblk->index = index;
> -
> - /* configure queue flush support */
> - virtblk_update_cache_mode(vdev);
> -
> - /* If disk is read-only in the host, the guest should obey */
> - if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
> - set_disk_ro(vblk->disk, 1);
> -
> /* We can handle whatever the host told us to handle. */
> blk_queue_max_segments(q, sg_elems);
>
> @@ -1011,12 +929,13 @@ static int virtblk_probe(struct virtio_device *vdev)
> dev_err(&vdev->dev,
> "virtio_blk: invalid block size: 0x%x\n",
> blk_size);
> - goto out_cleanup_disk;
> + return err;
> }
>
> blk_queue_logical_block_size(q, blk_size);
> - } else
> + } else {
> blk_size = queue_logical_block_size(q);
> + }
>
> /* Use topology information if available */
> err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
> @@ -1075,19 +994,136 @@ static int virtblk_probe(struct virtio_device
*vdev)
> blk_queue_max_write_zeroes_sectors(q, v ? v : UINT_MAX);
> }
>
> + return 0;
> +}
> +
> +static void virtblk_tagset_put(struct virtio_blk *vblk)
> +{
> + put_disk(vblk->disk);
> + blk_mq_free_tag_set(&vblk->tag_set);
> +}
> +
> +static void virtblk_tagset_free(struct virtio_blk *vblk)
> +{
> + del_gendisk(vblk->disk);
> + blk_mq_free_tag_set(&vblk->tag_set);
> +}
> +
> +static int virtblk_tagset_alloc(struct virtio_blk *vblk,
> + unsigned int queue_depth)
> +{
> + int err;
> +
> + memset(&vblk->tag_set, 0, sizeof(vblk->tag_set));
> + vblk->tag_set.ops = &virtio_mq_ops;
> + vblk->tag_set.queue_depth = queue_depth;
> + vblk->tag_set.numa_node = NUMA_NO_NODE;
> + vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
> + vblk->tag_set.cmd_size > + sizeof(struct virtblk_req) +
> + sizeof(struct scatterlist) * VIRTIO_BLK_INLINE_SG_CNT;
> + vblk->tag_set.driver_data = vblk;
> + vblk->tag_set.nr_hw_queues = vblk->num_vqs;
> + vblk->tag_set.nr_maps = 1;
> + if (vblk->io_queues[HCTX_TYPE_POLL])
> + vblk->tag_set.nr_maps = 3;
> +
> + err = blk_mq_alloc_tag_set(&vblk->tag_set);
> + if (err)
> + return err;
> +
> + vblk->disk = blk_mq_alloc_disk(&vblk->tag_set, vblk);
> + if (IS_ERR(vblk->disk)) {
> + err = PTR_ERR(vblk->disk);
> + goto out_free_tags;
> + }
> +
> + return 0;
> +
> +out_free_tags:
> + blk_mq_free_tag_set(&vblk->tag_set);
> + return err;
> +}
> +
> +static int virtblk_probe(struct virtio_device *vdev)
> +{
> + struct virtio_blk *vblk;
> + int err, index;
> + unsigned int queue_depth;
> +
> + if (!vdev->config->get) {
> + dev_err(&vdev->dev, "%s failure: config access
disabled\n",
> + __func__);
> + return -EINVAL;
> + }
> +
> + err = ida_simple_get(&vd_index_ida, 0, minor_to_index(1 <<
MINORBITS),
> + GFP_KERNEL);
> + if (err < 0)
> + goto out;
> + index = err;
> +
> + vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
> + if (!vblk) {
> + err = -ENOMEM;
> + goto out_free_index;
> + }
> +
> + mutex_init(&vblk->vdev_mutex);
> +
> + vblk->vdev = vdev;
> +
> + INIT_WORK(&vblk->config_work, virtblk_config_changed_work);
> +
> + err = init_vq(vblk);
> + if (err)
> + goto out_free_vblk;
> +
> + /* Default queue sizing is to fill the ring. */
> + if (!virtblk_queue_depth) {
> + queue_depth = vblk->vqs[0].vq->num_free;
> + /* ... but without indirect descs, we use 2 descs per req */
> + if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC))
> + queue_depth /= 2;
> + } else {
> + queue_depth = virtblk_queue_depth;
> + }
> +
> + err = virtblk_tagset_alloc(vblk, queue_depth);
> + if (err)
> + goto out_free_vq;
> +
> + virtblk_name_format("vd", index, vblk->disk->disk_name,
DISK_NAME_LEN);
> +
> + vblk->disk->major = major;
> + vblk->disk->first_minor = index_to_minor(index);
> + vblk->disk->minors = 1 << PART_BITS;
> + vblk->disk->private_data = vblk;
> + vblk->disk->fops = &virtblk_fops;
> + vblk->index = index;
> +
> + /* configure queue flush support */
> + virtblk_update_cache_mode(vdev);
> +
> + /* If disk is read-only in the host, the guest should obey */
> + if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
> + set_disk_ro(vblk->disk, 1);
> +
> + err = virtblk_q_limits_set(vdev, vblk->disk->queue);
> + if (err)
> + goto out_tagset_put;
> +
> virtblk_update_capacity(vblk, false);
> virtio_device_ready(vdev);
>
> err = device_add_disk(&vdev->dev, vblk->disk,
virtblk_attr_groups);
> if (err)
> - goto out_cleanup_disk;
> + goto out_tagset_put;
>
> return 0;
>
> -out_cleanup_disk:
> - put_disk(vblk->disk);
> -out_free_tags:
> - blk_mq_free_tag_set(&vblk->tag_set);
> +out_tagset_put:
> + virtblk_tagset_put(vblk);
> out_free_vq:
> vdev->config->del_vqs(vdev);
> kfree(vblk->vqs);
> @@ -1106,8 +1142,7 @@ static void virtblk_remove(struct virtio_device
*vdev)
> /* Make sure no work handler is accessing the device. */
> flush_work(&vblk->config_work);
>
> - del_gendisk(vblk->disk);
> - blk_mq_free_tag_set(&vblk->tag_set);
> + virtblk_tagset_free(vblk);
>
> mutex_lock(&vblk->vdev_mutex);
>
> --
> 2.18.1