[RFC PATCH 2/2] nvme: add simple copy support

[Keith Busch]

On Tue, Dec 01, 2020 at 11:09:49AM +0530, SelvaKumar S wrote:
> +static void nvme_config_copy(struct gendisk *disk, struct nvme_ns *ns,
> +				       struct nvme_id_ns *id)
> +{
> +	struct nvme_ctrl *ctrl = ns->ctrl;
> +	struct request_queue *queue = disk->queue;
> +
> +	if (!(ctrl->oncs & NVME_CTRL_ONCS_COPY)) {
> +		queue->limits.max_copy_sectors = 0;
> +		blk_queue_flag_clear(QUEUE_FLAG_COPY, queue);
> +		return;
> +	}
> +
> +	/* setting copy limits */
> +	ns->mcl = le64_to_cpu(id->mcl);
> +	ns->mssrl = le32_to_cpu(id->mssrl);
> +	ns->msrc = id->msrc;

These are not used anywhere outside this function, so there's no need to
add members to the struct.

> +	if (blk_queue_flag_test_and_set(QUEUE_FLAG_COPY, queue))
> +		return;

The queue limits are not necessarily the same each time we're called to
update the disk info, so this return shouldn't be here.

> +
> +	queue->limits.max_copy_sectors = ns->mcl * (1 << (ns->lba_shift - 9));
> +	queue->limits.max_copy_range_sectors = ns->mssrl *
> +		(1 << (ns->lba_shift - 9));
> +	queue->limits.max_copy_nr_ranges = ns->msrc + 1;
> +}

<>

> @@ -2045,6 +2133,7 @@ static void nvme_update_disk_info(struct gendisk *disk,
>  	set_capacity_and_notify(disk, capacity);
>  
>  	nvme_config_discard(disk, ns);
> +	nvme_config_copy(disk, ns, id);
>  	nvme_config_write_zeroes(disk, ns);
>  
>  	if (id->nsattr & NVME_NS_ATTR_RO)
> @@ -3014,6 +3103,7 @@ int nvme_init_identify(struct nvme_ctrl *ctrl)
>  	ctrl->oaes = le32_to_cpu(id->oaes);
>  	ctrl->wctemp = le16_to_cpu(id->wctemp);
>  	ctrl->cctemp = le16_to_cpu(id->cctemp);
> +	ctrl->ocfs = le32_to_cpu(id->ocfs);

ocfs is not used anywhere.