Re: [PATCH v2] ocfs2: heartbeat: replace simple_strtoul with kstrtoul

[Joseph Qi <joseph.qi@linux.alibaba.com>]

On 11/15/24 3:51 PM, Daniel Yang wrote:
> The function simple_strtoul is deprecated due to ignoring overflows and
> also requires clunkier error checking. Replacing with kstrtoul() leads
> to safer code and cleaner error checking.
> 
> Signed-off-by: Daniel Yang <danielyangkang@gmail.com>
> ---
> v1->v2: moved ret definition and removed blank lines
> 
>  fs/ocfs2/cluster/heartbeat.c | 15 +++++++--------
>  1 file changed, 7 insertions(+), 8 deletions(-)
> 
> diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c
> index dff18efbc..84ee5e340 100644
> --- a/fs/ocfs2/cluster/heartbeat.c
> +++ b/fs/ocfs2/cluster/heartbeat.c
> @@ -1536,9 +1536,8 @@ static int o2hb_read_block_input(struct o2hb_region *reg,
>  {
>  	unsigned long bytes;
>  	char *p = (char *)page;
> -
> -	bytes = simple_strtoul(p, &p, 0);
> -	if (!p || (*p && (*p != '\n')))
> +	int ret = kstrtoul(p, 0, &bytes);
> +	if (ret)

The preferred code style is:

...
int ret;

ret = kstrtoul(p, 0, &bytes);
if (ret < 0)
	return ret;

>  		return -EINVAL;
>  
>  	/* Heartbeat and fs min / max block sizes are the same. */
> @@ -1623,12 +1622,13 @@ static ssize_t o2hb_region_blocks_store(struct config_item *item,
>  	struct o2hb_region *reg = to_o2hb_region(item);
>  	unsigned long tmp;
>  	char *p = (char *)page;
> +	int ret;
>  
>  	if (reg->hr_bdev_file)
>  		return -EINVAL;
>  
> -	tmp = simple_strtoul(p, &p, 0);
> -	if (!p || (*p && (*p != '\n')))
> +	ret = kstrtoul(p, 0, &tmp);
> +	if (ret)
>  		return -EINVAL;

Better to return 'ret' directly since it may be -ERANGE.

>  
>  	if (tmp > O2NM_MAX_NODES || tmp == 0)
> @@ -2141,9 +2141,8 @@ static ssize_t o2hb_heartbeat_group_dead_threshold_store(struct config_item *ite
>  {
>  	unsigned long tmp;
>  	char *p = (char *)page;
> -
> -	tmp = simple_strtoul(p, &p, 10);
> -	if (!p || (*p && (*p != '\n')))
> +	int ret = kstrtoul(p, 10, &tmp);
> +	if (ret)
>                  return -EINVAL;

Prefer to:

...
int ret;

ret = kstrtoul(p, 10, &tmp);
if (ret < 0)
	return ret;

Thanks,
Joseph
>  
>  	/* this will validate ranges for us. */