Re: [PATCH 05/23] libnvdimm/labels: Add blk isetcookie set / validation helpers

[Jonathan Cameron <Jonathan.Cameron@Huawei.com>]

On Mon, 9 Aug 2021 15:28:14 -0700
Dan Williams <dan.j.williams@intel.com> wrote:

> In preparation for LIBNVDIMM to manage labels on CXL devices deploy
> helpers that abstract the label type from the implementation. The CXL
> label format is mostly similar to the EFI label format with concepts /
> fields added, like dynamic region creation and label type guids, and
> other concepts removed like BLK-mode and interleave-set-cookie ids.
> 
> Given BLK-mode is not even supported on CXL push hide the BLK-mode
> specific details inside the helpers.
> 
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
>  drivers/nvdimm/label.c          |   30 ++++++++++++++++++++++++++++--
>  drivers/nvdimm/namespace_devs.c |    9 ++-------
>  drivers/nvdimm/nd.h             |    4 ++++
>  3 files changed, 34 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/nvdimm/label.c b/drivers/nvdimm/label.c
> index 3f73412dd438..d1a7f399cfe4 100644
> --- a/drivers/nvdimm/label.c
> +++ b/drivers/nvdimm/label.c
> @@ -898,6 +898,33 @@ static struct resource *to_resource(struct nvdimm_drvdata *ndd,
>  	return NULL;
>  }
>  
> +static void nsl_set_blk_isetcookie(struct nvdimm_drvdata *ndd,
> +				   struct nd_namespace_label *nd_label,
> +				   u64 isetcookie)
> +{
> +	if (namespace_label_has(ndd, type_guid)) {
> +		nsl_set_isetcookie(ndd, nd_label, isetcookie);
> +		return;
> +	}
> +	nsl_set_isetcookie(ndd, nd_label, 0); /* N/A */
> +}
> +
> +bool nsl_validate_blk_isetcookie(struct nvdimm_drvdata *ndd,
> +				 struct nd_namespace_label *nd_label,
> +				 u64 isetcookie)
> +{
> +	if (!namespace_label_has(ndd, type_guid))
> +		return true;
> +
> +	if (nsl_get_isetcookie(ndd, nd_label) != isetcookie) {
> +		dev_dbg(ndd->dev, "expect cookie %#llx got %#llx\n", isetcookie,
> +			nsl_get_isetcookie(ndd, nd_label));
> +		return false;
> +	}
> +
> +	return true;
> +}
> +
>  /*
>   * 1/ Account all the labels that can be freed after this update
>   * 2/ Allocate and write the label to the staging (next) index
> @@ -1042,12 +1069,11 @@ static int __blk_label_update(struct nd_region *nd_region,
>  				nsl_set_nlabel(ndd, nd_label, 0xffff);
>  				nsl_set_position(ndd, nd_label, 0xffff);
>  			}
> -			nsl_set_isetcookie(ndd, nd_label, nd_set->cookie2);
>  		} else {
>  			nsl_set_nlabel(ndd, nd_label, 0); /* N/A */
>  			nsl_set_position(ndd, nd_label, 0); /* N/A */
> -			nsl_set_isetcookie(ndd, nd_label, 0); /* N/A */
>  		}
> +		nsl_set_blk_isetcookie(ndd, nd_label, nd_set->cookie2);
>  
>  		nsl_set_dpa(ndd, nd_label, res->start);
>  		nsl_set_rawsize(ndd, nd_label, resource_size(res));
> diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
> index fb9e080ce654..fbd0c2fcea4a 100644
> --- a/drivers/nvdimm/namespace_devs.c
> +++ b/drivers/nvdimm/namespace_devs.c
> @@ -2272,14 +2272,9 @@ static struct device *create_namespace_blk(struct nd_region *nd_region,
>  					&nd_label->type_guid);
>  			return ERR_PTR(-EAGAIN);
>  		}
> -
> -		if (nd_label->isetcookie != __cpu_to_le64(nd_set->cookie2)) {
> -			dev_dbg(ndd->dev, "expect cookie %#llx got %#llx\n",
> -					nd_set->cookie2,
> -					nsl_get_isetcookie(ndd, nd_label));
> -			return ERR_PTR(-EAGAIN);
> -		}
>  	}
> +	if (!nsl_validate_blk_isetcookie(ndd, nd_label, nd_set->cookie2))
> +		return ERR_PTR(-EAGAIN);
>  
>  	nsblk = kzalloc(sizeof(*nsblk), GFP_KERNEL);
>  	if (!nsblk)
> diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
> index 416846fe7818..2a9a608b7f17 100644
> --- a/drivers/nvdimm/nd.h
> +++ b/drivers/nvdimm/nd.h
> @@ -176,6 +176,10 @@ static inline void nsl_set_lbasize(struct nvdimm_drvdata *ndd,
>  	nd_label->lbasize = __cpu_to_le64(lbasize);
>  }
>  
> +bool nsl_validate_blk_isetcookie(struct nvdimm_drvdata *ndd,
> +				 struct nd_namespace_label *nd_label,
> +				 u64 isetcookie);
> +
>  struct nd_region_data {
>  	int ns_count;
>  	int ns_active;
>