On Thu, May 12, 2022 at 06:05:37PM -0700, Andrew Morton wrote:
> On Wed, 27 Apr 2022 18:17:29 +0300 Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
>
> > On Tue, Apr 26, 2022 at 10:30:40PM +0530, Jagdish Gediya wrote:
> > > Sysfs input conversion to corrosponding bool value e.g. "false" or "0"
> > > to false, "true" or "1" to true are currently handled through strncmp
> > > at multiple places. Use kstrtobool() to convert sysfs input to bool
> > > value.
> >
> > ...
> >
> > > + if (kstrtobool(buf, &numa_demotion_enabled))
> > > return -EINVAL;
> >
> > Hmm... The commit message doesn't explain what's wrong with the error codes
> > returned by kstrtobool(). Can't it be
> >
> > ret = kstrtobool();
> > if (ret)
> > return ret;
> >
> > ?
>
> Jagdish fell asleep.
Sorry, I was away from work for few days.
> Yes, I agree. It has no practical difference at present because
> kstrtobool() can only return 0 or -EINVAL. I did this:
>
> --- a/mm/migrate.c~mm-convert-sysfs-input-to-bool-using-kstrtobool-fix
> +++ a/mm/migrate.c
> @@ -2523,8 +2523,10 @@ static ssize_t numa_demotion_enabled_sto
> struct kobj_attribute *attr,
> const char *buf, size_t count)
> {
> - if (kstrtobool(buf, &numa_demotion_enabled))
> - return -EINVAL;
> + ssize_t ret;
> +
> + ret = kstrtobool(buf, &numa_demotion_enabled);
> + return ret;
>
> return count;
> }
> --- a/mm/swap_state.c~mm-convert-sysfs-input-to-bool-using-kstrtobool-fix
> +++ a/mm/swap_state.c
> @@ -874,8 +874,11 @@ static ssize_t vma_ra_enabled_store(stru
> struct kobj_attribute *attr,
> const char *buf, size_t count)
> {
> - if (kstrtobool(buf, &enable_vma_readahead))
> - return -EINVAL;
> + ssize_t ret;
> +
> + ret = kstrtobool(buf, &enable_vma_readahead);
> + if (ret)
> + return ret;
>
> return count;
> }
> _
>
