Re: [PATCH v3] mm/damon/sysfs: return 'err' value when call kstrtoul() failed

[haoxin]

Hi SJ,


在 2022/9/21 上午12:35, SeongJae Park 写道:
> From: Xin Hao <xhao@xxxxxxxxxxxxxxxxx>
>
> We had better return the 'err' value when calling kstrtoul() failed, so
> the user will know why it really fails, there do little change, let it
> return the 'err' value when failed.
>
> Suggested-by: SeongJae Park <sj@xxxxxxxxxx>
> Signed-off-by: Xin Hao <xhao@xxxxxxxxxxxxxxxxx>
> Reviewed-by: SeongJae Park <sj@xxxxxxxxxx>
> Signed-off-by: SeongJae Park <sj@xxxxxxxxxx>
>
> ---
> Changes from v2
> (https://lore.kernel.org/damon/20220920025158.70293-1-xhao@xxxxxxxxxxxxxxxxx/)
> - Move patch changelog outside of the commit message area

Thanks for fix this stupid bug，i will nerver make it happen once again.

Reviewed-by: Xin Hao <xhao@xxxxxxxxxxxxxxxxx>

> Changes from v1
> (https://lore.kernel.org/linux-mm/20220919170305.61335-1-sj@xxxxxxxxxx/T/)
> - keep the 'err' variable, and return the 'err' value when failed.
>
>   mm/damon/sysfs.c | 46 ++++++++++++++--------------------------------
>   1 file changed, 14 insertions(+), 32 deletions(-)
>
> diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c
> index 0cca1909bf67..455215a5c059 100644
> --- a/mm/damon/sysfs.c
> +++ b/mm/damon/sysfs.c
> @@ -58,7 +58,7 @@ static ssize_t min_store(struct kobject *kobj, struct kobj_attribute *attr,
>
>   	err = kstrtoul(buf, 0, &min);
>   	if (err)
> -		return -EINVAL;
> +		return err;
>
>   	range->min = min;
>   	return count;
> @@ -83,7 +83,7 @@ static ssize_t max_store(struct kobject *kobj, struct kobj_attribute *attr,
>
>   	err = kstrtoul(buf, 0, &max);
>   	if (err)
> -		return -EINVAL;
> +		return err;
>
>   	range->max = max;
>   	return count;
> @@ -291,9 +291,7 @@ static ssize_t interval_us_store(struct kobject *kobj,
>   			struct damon_sysfs_watermarks, kobj);
>   	int err = kstrtoul(buf, 0, &watermarks->interval_us);
>
> -	if (err)
> -		return -EINVAL;
> -	return count;
> +	return err ? err : count;
>   }
>
>   static ssize_t high_show(struct kobject *kobj,
> @@ -312,9 +310,7 @@ static ssize_t high_store(struct kobject *kobj,
>   			struct damon_sysfs_watermarks, kobj);
>   	int err = kstrtoul(buf, 0, &watermarks->high);
>
> -	if (err)
> -		return -EINVAL;
> -	return count;
> +	return err ? err : count;
>   }
>
>   static ssize_t mid_show(struct kobject *kobj,
> @@ -333,9 +329,7 @@ static ssize_t mid_store(struct kobject *kobj,
>   			struct damon_sysfs_watermarks, kobj);
>   	int err = kstrtoul(buf, 0, &watermarks->mid);
>
> -	if (err)
> -		return -EINVAL;
> -	return count;
> +	return err ? err : count;
>   }
>
>   static ssize_t low_show(struct kobject *kobj,
> @@ -354,9 +348,7 @@ static ssize_t low_store(struct kobject *kobj,
>   			struct damon_sysfs_watermarks, kobj);
>   	int err = kstrtoul(buf, 0, &watermarks->low);
>
> -	if (err)
> -		return -EINVAL;
> -	return count;
> +	return err ? err : count;
>   }
>
>   static void damon_sysfs_watermarks_release(struct kobject *kobj)
> @@ -437,9 +429,7 @@ static ssize_t sz_permil_store(struct kobject *kobj,
>   			struct damon_sysfs_weights, kobj);
>   	int err = kstrtouint(buf, 0, &weights->sz);
>
> -	if (err)
> -		return -EINVAL;
> -	return count;
> +	return err ? err : count;
>   }
>
>   static ssize_t nr_accesses_permil_show(struct kobject *kobj,
> @@ -458,9 +448,7 @@ static ssize_t nr_accesses_permil_store(struct kobject *kobj,
>   			struct damon_sysfs_weights, kobj);
>   	int err = kstrtouint(buf, 0, &weights->nr_accesses);
>
> -	if (err)
> -		return -EINVAL;
> -	return count;
> +	return err ? err : count;
>   }
>
>   static ssize_t age_permil_show(struct kobject *kobj,
> @@ -479,9 +467,7 @@ static ssize_t age_permil_store(struct kobject *kobj,
>   			struct damon_sysfs_weights, kobj);
>   	int err = kstrtouint(buf, 0, &weights->age);
>
> -	if (err)
> -		return -EINVAL;
> -	return count;
> +	return err ? err : count;
>   }
>
>   static void damon_sysfs_weights_release(struct kobject *kobj)
> @@ -1111,9 +1097,7 @@ static ssize_t start_store(struct kobject *kobj, struct kobj_attribute *attr,
>   			struct damon_sysfs_region, kobj);
>   	int err = kstrtoul(buf, 0, &region->start);
>
> -	if (err)
> -		return -EINVAL;
> -	return count;
> +	return err ? err : count;
>   }
>
>   static ssize_t end_show(struct kobject *kobj, struct kobj_attribute *attr,
> @@ -1132,9 +1116,7 @@ static ssize_t end_store(struct kobject *kobj, struct kobj_attribute *attr,
>   			struct damon_sysfs_region, kobj);
>   	int err = kstrtoul(buf, 0, &region->end);
>
> -	if (err)
> -		return -EINVAL;
> -	return count;
> +	return err ? err : count;
>   }
>
>   static void damon_sysfs_region_release(struct kobject *kobj)
> @@ -1528,7 +1510,7 @@ static ssize_t sample_us_store(struct kobject *kobj,
>   	int err = kstrtoul(buf, 0, &us);
>
>   	if (err)
> -		return -EINVAL;
> +		return err;
>
>   	intervals->sample_us = us;
>   	return count;
> @@ -1552,7 +1534,7 @@ static ssize_t aggr_us_store(struct kobject *kobj, struct kobj_attribute *attr,
>   	int err = kstrtoul(buf, 0, &us);
>
>   	if (err)
> -		return -EINVAL;
> +		return err;
>
>   	intervals->aggr_us = us;
>   	return count;
> @@ -1576,7 +1558,7 @@ static ssize_t update_us_store(struct kobject *kobj,
>   	int err = kstrtoul(buf, 0, &us);
>
>   	if (err)
> -		return -EINVAL;
> +		return err;
>
>   	intervals->update_us = us;
>   	return count;
> --
> 2.31.0