Re: [PATCH v2 1/3] lsblk: factor out function to read sysfs param as bytes

[Damien Le Moal <Damien.LeMoal@wdc.com>]

On 2021/08/27 16:35, Naohiro Aota wrote:
> Factor out a new function device_read_bytes() to read a sysfs path as bytes
> for a preparation for the next commit and to reduce the code duplication.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> ---
>  misc-utils/lsblk.c | 45 ++++++++++++++++++++-------------------------
>  1 file changed, 20 insertions(+), 25 deletions(-)
> 
> diff --git a/misc-utils/lsblk.c b/misc-utils/lsblk.c
> index 100eba0779f8..775a6d832076 100644
> --- a/misc-utils/lsblk.c
> +++ b/misc-utils/lsblk.c
> @@ -708,6 +708,24 @@ static uint64_t device_get_discard_granularity(struct lsblk_device *dev)
>  	return dev->discard_granularity;
>  }
>  
> +static void device_read_bytes(struct lsblk_device *dev, char *path, char **str,
> +			      uint64_t *sortdata)
> +{
> +	if (lsblk->bytes) {
> +		ul_path_read_string(dev->sysfs, str, path);
> +		if (sortdata)
> +			str2u64(*str, sortdata);

You could return early here to avoid the else...

> +	} else {
> +		uint64_t x;
> +
> +		if (ul_path_read_u64(dev->sysfs, &x, path) == 0) {
> +			*str = size_to_human_string(SIZE_SUFFIX_1LETTER, x);
> +			if (sortdata)
> +				*sortdata = x;
> +		}
> +	}
> +}
> +
>  /*
>   * Generates data (string) for column specified by column ID for specified device. If sortdata
>   * is not NULL then returns number usable to sort the column if the data are available for the
> @@ -1033,18 +1051,7 @@ static char *device_get_data(
>  		}
>  		break;
>  	case COL_DMAX:
> -		if (lsblk->bytes) {
> -			ul_path_read_string(dev->sysfs, &str, "queue/discard_max_bytes");
> -			if (sortdata)
> -				str2u64(str, sortdata);
> -		} else {
> -			uint64_t x;
> -			if (ul_path_read_u64(dev->sysfs, &x, "queue/discard_max_bytes") == 0) {
> -				str = size_to_human_string(SIZE_SUFFIX_1LETTER, x);
> -				if (sortdata)
> -					*sortdata = x;
> -			}
> -		}
> +		device_read_bytes(dev, "queue/discard_max_bytes", &str, sortdata);
>  		break;
>  	case COL_DZERO:
>  		if (device_get_discard_granularity(dev) > 0)
> @@ -1053,19 +1060,7 @@ static char *device_get_data(
>  			str = xstrdup("0");
>  		break;
>  	case COL_WSAME:
> -		if (lsblk->bytes) {
> -			ul_path_read_string(dev->sysfs, &str, "queue/write_same_max_bytes");
> -			if (sortdata)
> -				str2u64(str, sortdata);
> -		} else {
> -			uint64_t x;
> -
> -			if (ul_path_read_u64(dev->sysfs, &x, "queue/write_same_max_bytes") == 0) {
> -				str = size_to_human_string(SIZE_SUFFIX_1LETTER, x);
> -				if (sortdata)
> -					*sortdata = x;
> -			}
> -		}
> +		device_read_bytes(dev, "queue/write_same_max_bytes", &str, sortdata);
>  		if (!str)
>  			str = xstrdup("0");
>  		break;
> 

Apart from the optional nit above, looks good to me.

Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>


-- 
Damien Le Moal
Western Digital Research