Re: [PATCH] bcachefs: return early for negative values when parsing BCH_OPT_UINT

[Kent Overstreet]

On Sun, Apr 06, 2025 at 09:59:30PM +0800, Integral wrote:
> Currently, when a negative integer is passed as an argument, the error
> message incorrectly states "too big" due to the value being cast to an
> unsigned integer:
> 
>     > bcachefs format --block_size=-1 bcachefs.img
>     invalid option: block_size: too big (max 65536)
> 
> To resolve this issue, return early for negative values before calling
> bch2_opt_validate().
> 
> Signed-off-by: Integral <integral@xxxxxxxxxxxxxxx>

No new -EINVAL in kernel code :)

> ---
>  fs/bcachefs/opts.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/bcachefs/opts.c b/fs/bcachefs/opts.c
> index e64777ecf44f..31f90c177c6c 100644
> --- a/fs/bcachefs/opts.c
> +++ b/fs/bcachefs/opts.c
> @@ -360,9 +360,15 @@ int bch2_opt_parse(struct bch_fs *c,
>  			return -EINVAL;
>  		}
>  
> -		ret = opt->flags & OPT_HUMAN_READABLE
> -			? bch2_strtou64_h(val, res)
> -			: kstrtou64(val, 10, res);
> +		if (*val != '-') {
> +			ret = opt->flags & OPT_HUMAN_READABLE
> +			    ? bch2_strtou64_h(val, res)
> +			    : kstrtou64(val, 10, res);
> +		} else {
> +			prt_printf(err, "%s: must be a non-negative number", opt->attr.name);
> +			return -EINVAL;
> +		}
> +
>  		if (ret < 0) {
>  			if (err)
>  				prt_printf(err, "%s: must be a number",
> -- 
> 2.49.0
>