Re: [PATCH] zram: use DEVICE_ATTR_[RW|RO|WO] to define zram sys device attribute

[Jerome Marchand]

On 12/03/2014 01:38 PM, Ganesh Mahendran wrote:
> In current zram, we use DEVICE_ATTR() to define sys device attributes.
> SO, we need to set (S_IRUGO | S_IWUSR) permission and other
> arguments manually.
> Linux kernel has already provided macro DEVICE_ATTR_[RW|RO|WO] to define
> sys device attribute. It is simple and readable.

It does look cleaner.

> 
> This patch uses kernel defined macro DEVICE_ATTR_[RW|RO|WO] to define
> zram device attribute.
> 
> Signed-off-by: Ganesh Mahendran <opensource.ganesh@xxxxxxxxx>

Acked-by: Jerome Marchand <jmarchan@xxxxxxxxxx>

Thanks,
Jerome
> ---
>  drivers/block/zram/zram_drv.c |   28 +++++++++++-----------------
>  1 file changed, 11 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
> index 8eb0d85..53fbd61 100644
> --- a/drivers/block/zram/zram_drv.c
> +++ b/drivers/block/zram/zram_drv.c
> @@ -44,15 +44,14 @@ static const char *default_compressor = "lzo";
>  static unsigned int num_devices = 1;
>  
>  #define ZRAM_ATTR_RO(name)						\
> -static ssize_t zram_attr_##name##_show(struct device *d,		\
> +static ssize_t name##_show(struct device *d,		\
>  				struct device_attribute *attr, char *b)	\
>  {									\
>  	struct zram *zram = dev_to_zram(d);				\
>  	return scnprintf(b, PAGE_SIZE, "%llu\n",			\
>  		(u64)atomic64_read(&zram->stats.name));			\
>  }									\
> -static struct device_attribute dev_attr_##name =			\
> -	__ATTR(name, S_IRUGO, zram_attr_##name##_show, NULL);
> +static DEVICE_ATTR_RO(name);
>  
>  static inline int init_done(struct zram *zram)
>  {
> @@ -994,20 +993,15 @@ static const struct block_device_operations zram_devops = {
>  	.owner = THIS_MODULE
>  };
>  
> -static DEVICE_ATTR(disksize, S_IRUGO | S_IWUSR,
> -		disksize_show, disksize_store);
> -static DEVICE_ATTR(initstate, S_IRUGO, initstate_show, NULL);
> -static DEVICE_ATTR(reset, S_IWUSR, NULL, reset_store);
> -static DEVICE_ATTR(orig_data_size, S_IRUGO, orig_data_size_show, NULL);
> -static DEVICE_ATTR(mem_used_total, S_IRUGO, mem_used_total_show, NULL);
> -static DEVICE_ATTR(mem_limit, S_IRUGO | S_IWUSR, mem_limit_show,
> -		mem_limit_store);
> -static DEVICE_ATTR(mem_used_max, S_IRUGO | S_IWUSR, mem_used_max_show,
> -		mem_used_max_store);
> -static DEVICE_ATTR(max_comp_streams, S_IRUGO | S_IWUSR,
> -		max_comp_streams_show, max_comp_streams_store);
> -static DEVICE_ATTR(comp_algorithm, S_IRUGO | S_IWUSR,
> -		comp_algorithm_show, comp_algorithm_store);
> +static DEVICE_ATTR_RW(disksize);
> +static DEVICE_ATTR_RO(initstate);
> +static DEVICE_ATTR_WO(reset);
> +static DEVICE_ATTR_RO(orig_data_size);
> +static DEVICE_ATTR_RO(mem_used_total);
> +static DEVICE_ATTR_RW(mem_limit);
> +static DEVICE_ATTR_RW(mem_used_max);
> +static DEVICE_ATTR_RW(max_comp_streams);
> +static DEVICE_ATTR_RW(comp_algorithm);
>  
>  ZRAM_ATTR_RO(num_reads);
>  ZRAM_ATTR_RO(num_writes);
>

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