Re: [PATCH 1/2] erofs: using macro instead of definition of log functions

[Gao Xiang <hsiangkao@linux.alibaba.com>]

Hi Hao,

On 2024/10/16 23:24, Gou Hao wrote:
> No functional change intended.
> 
> Signed-off-by: Gou Hao <gouhao@uniontech.com>
> ---
>   fs/erofs/super.c | 51 ++++++++++++++++++------------------------------
>   1 file changed, 19 insertions(+), 32 deletions(-)
> 
> diff --git a/fs/erofs/super.c b/fs/erofs/super.c
> index 666873f745da..b04f888c8123 100644
> --- a/fs/erofs/super.c
> +++ b/fs/erofs/super.c
> @@ -18,39 +18,26 @@
>   
>   static struct kmem_cache *erofs_inode_cachep __read_mostly;
>   
> -void _erofs_err(struct super_block *sb, const char *func, const char *fmt, ...)
> -{
> -	struct va_format vaf;
> -	va_list args;
> -
> -	va_start(args, fmt);
> -
> -	vaf.fmt = fmt;
> -	vaf.va = &args;
> -
> -	if (sb)
> -		pr_err("(device %s): %s: %pV", sb->s_id, func, &vaf);
> -	else
> -		pr_err("%s: %pV", func, &vaf);
> -	va_end(args);
> -}
> -
> -void _erofs_info(struct super_block *sb, const char *func, const char *fmt, ...)
> -{
> -	struct va_format vaf;
> -	va_list args;
> -
> -	va_start(args, fmt);
> -
> -	vaf.fmt = fmt;
> -	vaf.va = &args;
> +#define _erofs_log_def(name) \
> +	void _erofs_##name(struct super_block *sb, const char *func, const char *fmt, ...) \
> +	{ \
> +		struct va_format vaf; \
> +		va_list args; \
> +		\
> +		va_start(args, (fmt)); \
> +		\
> +		vaf.fmt = (fmt); \
> +		vaf.va = &args; \
> +		\
> +		if ((sb)) \
> +			pr_##name("(device %s): %s: %pV", (sb)->s_id, (func), &vaf); \
> +		else \
> +			pr_##name("%s: %pV", (func), &vaf); \
> +		va_end(args); \
> +	}

Thanks for the patch!

Although code simplicity is quite important for EROFS, but
I'm not sure introducing unnecessary macro definitions (which
can be avoided) is better for code readability.

I wonder if we can put this into another way, like the current
_btrfs_printk() and _f2fs_printk() if we really need to work
on this.

Thanks,
Gao Xiang