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Subject: Re: [PATCH 1/2] erofs: add sysfs interface
To:     Joe Perches <joe@perches.com>, linux-erofs@lists.ozlabs.org
Cc:     guoweichao@oppo.com, guanyuwei@oppo.com, yh@oppo.com,
        zhangshiming@oppo.com, linux-kernel@vger.kernel.org
References: <20211109025445.12427-1-huangjianan@oppo.com>
 <cc9807eb594b042ec2cd958f0c70c2f3dd12d58b.camel@perches.com>
From:   Huang Jianan <huangjianan@oppo.com>
Message-ID: <a96677ff-dad0-9baa-00ba-ccc89ac3fb49@oppo.com>
Date:   Tue, 9 Nov 2021 15:31:54 +0800
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?? 2021/11/9 11:14, Joe Perches д??:
> On Tue, 2021-11-09 at 10:54 +0800, Huang Jianan wrote:
>> Add sysfs interface to configure erofs related parameters in the
>> future.
> []
>> diff --git a/fs/erofs/sysfs.c b/fs/erofs/sysfs.c
> []
>> +static ssize_t erofs_attr_show(struct kobject *kobj,
>> +				struct attribute *attr, char *buf)
>> +{
>> +	struct erofs_sb_info *sbi = container_of(kobj, struct erofs_sb_info,
>> +						s_kobj);
>> +	struct erofs_attr *a = container_of(attr, struct erofs_attr, attr);
>> +	unsigned char *ptr = __struct_ptr(sbi, a->struct_type, a->offset);
>> +
>> +	switch (a->attr_id) {
>> +	case attr_feature:
>> +		return snprintf(buf, PAGE_SIZE, "supported\n");
>> +	case attr_pointer_ui:
>> +		if (!ptr)
>> +			return 0;
>> +		return snprintf(buf, PAGE_SIZE, "%u\n",
>> +				*((unsigned int *) ptr));
> Prefer sysfs_emit over snprintf
>
> 	case attr_feature:
> 		return sysfs_emit(buf, "supported\n");
> 	case attr_pointer_ui:
> 		...
> 		return sysfs_emit(buf, "%u\n", *(unsigned int *)ptr);
>
> etc...
>
Thanks for reminding this, I will fix it in the next version.

Thanks,
Jianan