On Tue 2022-04-26 12:10:01, Jagdish Gediya wrote:
> At many places in kernel, It is necessary to convert sysfs input
> to corrosponding bool value e.g. "false" or "0" need to be converted
> to bool false, "true" or "1" need to be converted to bool true,
> places where such conversion is needed currently check the input
> string manually, kstrtobool can be utilized at such places but
> currently kstrtobool doesn't have support to "false"/"true".
>
> Add "false"/"true" support to kstrtobool while string conversion
> to bool. Modify existing manual sysfs conversions to use kstrtobool().
It looks reasonable. I would just do it slightly other way, see
below.
> This patch doesn't have any functionality change.
This is not true. All kstrtobool() callers will react differently
on the "true"/"false" input.
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> Cc: Richard Fitzgerald <rf@xxxxxxxxxxxxxxxxxxxxx>
> Cc: Petr Mladek <pmladek@xxxxxxxx>
> Signed-off-by: Jagdish Gediya <jvgediya@xxxxxxxxxxxxx>
> ---
> change in v2:
> Modified kstrtobool to handle "false"/"true". Removed
> new function sysfs_strbool introduced in v1.
>
> lib/kstrtox.c | 7 +++++++
> mm/migrate.c | 6 +-----
> mm/swap_state.c | 6 +-----
> 3 files changed, 9 insertions(+), 10 deletions(-)
>
> diff --git a/lib/kstrtox.c b/lib/kstrtox.c
> index 886510d248e5..3a5e29557838 100644
> --- a/lib/kstrtox.c
> +++ b/lib/kstrtox.c
> @@ -377,6 +377,13 @@ int kstrtobool(const char *s, bool *res)
> }
> break;
> default:
> + if (!strncmp(s, "true", 4)) {
> + *res = true;
> + return 0;
> + } else if (!strncmp(s, "false", 5)) {
> + *res = false;
> + return 0;
It should be enough to check the first letter like we do in
the other cases. I mean to set true when s[0] is 'T' or 't'
and false when s[0] is 'F' or 'f'.
Also please update comment above the function definition.
> + }
> break;
> }
>
Best Regards,
Petr
