[PATCH 3/3] nvme-core: use macro defination to define dev attr

[Sagi Grimberg]

> Insated of duplicating the code for dhchap_secret & dhchap_ctrl_secret,
> define a macro to register device attribute to create device attribute
> that will also define store and show helpers.
> 
> Signed-off-by: Chaitanya Kulkarni <kch at nvidia.com>
> ---
>   drivers/nvme/host/sysfs.c | 66 +++++++++++++++------------------------
>   1 file changed, 25 insertions(+), 41 deletions(-)
> 
> diff --git a/drivers/nvme/host/sysfs.c b/drivers/nvme/host/sysfs.c
> index 515baf8d6402..e0a2a041e595 100644
> --- a/drivers/nvme/host/sysfs.c
> +++ b/drivers/nvme/host/sysfs.c
> @@ -407,17 +407,6 @@ static ssize_t dctype_show(struct device *dev,
>   static DEVICE_ATTR_RO(dctype);
>   
>   #ifdef CONFIG_NVME_AUTH
> -static ssize_t nvme_ctrl_dhchap_secret_show(struct device *dev,
> -		struct device_attribute *attr, char *buf)
> -{
> -	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
> -	struct nvmf_ctrl_options *opts = ctrl->opts;
> -
> -	if (!opts->dhchap_secret)
> -		return sysfs_emit(buf, "none\n");
> -	return sysfs_emit(buf, "%s\n", opts->dhchap_secret);
> -}
> -
>   static ssize_t nvme_dhchap_secret_store_common(struct nvme_ctrl *ctrl,
>   		const char *buf, size_t count, bool ctrl_secret)
>   {
> @@ -472,37 +461,32 @@ static ssize_t nvme_dhchap_secret_store_common(struct nvme_ctrl *ctrl,
>   	return count;
>   }
>   
> +#define NVME_AUTH_DEVICE_ATTR(NAME, cs)					\
> +static ssize_t nvme_ctrl_##NAME##_show(struct device *dev,		\
> +		struct device_attribute *attr, char *buf)		\
> +{									\
> +	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);			\
> +	struct nvmf_ctrl_options *opts = ctrl->opts;			\
> +									\
> +	if (!opts->NAME)						\

This is where these macros can really take things out of context...
The code just lost readability at this point.

> +		return sysfs_emit(buf, "none\n");			\
> +	return sysfs_emit(buf, "%s\n", opts->NAME);			\
> +}									\
> +									\
> +static ssize_t nvme_ctrl_##NAME##_store(struct device *dev,		\
> +		struct device_attribute *attr, const char *buf,		\
> +		size_t count)						\
> +{									\
> +	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);			\
> +									\
> +	return nvme_dhchap_secret_store_common(ctrl, buf, count, cs);	\
> +}									\
> +									\
> +static DEVICE_ATTR(NAME, S_IRUGO | S_IWUSR,				\
> +	nvme_ctrl_##NAME##_show, nvme_ctrl_##NAME##_store);		\
>   
> -static ssize_t nvme_ctrl_dhchap_secret_store(struct device *dev,
> -		struct device_attribute *attr, const char *buf, size_t count)
> -{
> -	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
> -
> -	return nvme_dhchap_secret_store_common(ctrl, buf, count, false);
> -}
> -
> -static DEVICE_ATTR(dhchap_secret, S_IRUGO | S_IWUSR,
> -	nvme_ctrl_dhchap_secret_show, nvme_ctrl_dhchap_secret_store);
> -
> -static ssize_t nvme_ctrl_dhchap_ctrl_secret_show(struct device *dev,
> -		struct device_attribute *attr, char *buf)
> -{
> -	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
> -	struct nvmf_ctrl_options *opts = ctrl->opts;
> -
> -	if (!opts->dhchap_ctrl_secret)
> -		return sysfs_emit(buf, "none\n");
> -	return sysfs_emit(buf, "%s\n", opts->dhchap_ctrl_secret);
> -}
> -
> -static ssize_t nvme_ctrl_dhchap_ctrl_secret_store(struct device *dev,
> -		struct device_attribute *attr, const char *buf, size_t count)
> -{
> -	return nvme_dhchap_secret_store_common(ctrl, buf, count, false);
> -}
> -
> -static DEVICE_ATTR(dhchap_ctrl_secret, S_IRUGO | S_IWUSR,
> -	nvme_ctrl_dhchap_ctrl_secret_show, nvme_ctrl_dhchap_ctrl_secret_store);
> +NVME_AUTH_DEVICE_ATTR(dhchap_secret, false);
> +NVME_AUTH_DEVICE_ATTR(dhchap_ctrl_secret, true);
>   #endif
>   
>   static struct attribute *nvme_dev_attrs[] = {