[PATCH v2] UBIFS: replace simple_strtoul() with kstrtoint()

[Geert Uytterhoeven]

On Tue, May 20, 2014 at 2:21 PM, Adrian Hunter <adrian.hunter at intel.com> wrote:
> On 05/20/2014 11:48 AM, Zhang Zhen wrote:
>> --- a/fs/ubifs/super.c
>> +++ b/fs/ubifs/super.c
>> @@ -1903,7 +1903,7 @@ const struct super_operations ubifs_super_operations = {
>>  static struct ubi_volume_desc *open_ubi(const char *name, int mode)
>>  {
>>       struct ubi_volume_desc *ubi;
>> -     int dev, vol;
>> +     int dev, vol, ret;
>>       char *endptr;
>>
>>       /* First, try to open using the device node path method */
>> @@ -1922,10 +1922,11 @@ static struct ubi_volume_desc *open_ubi(const char *name, int mode)
>>       if (!isdigit(name[3]))
>>               return ERR_PTR(-EINVAL);
>>
>> -     dev = simple_strtoul(name + 3, &endptr, 0);
>> +     endptr = (char *)name + 3;

Please make endptr const char *, so the cast can be killed.
Always think twice before adding a cast!

Ah, there's still another simple_strtoul() left below, that needs to be
converted first.

>> +     ret = kstrtoint(endptr, 0, &dev);
>
> But endptr is used in the code later, so this is wrong.

That was my first thought, too. But upon closer look, I think it's correct.

>>
>>       /* ubiY method */
>> -     if (*endptr == '\0')

endptr would point to the trailing nul on success...

>> +     if (!ret)

... which is now replaced by a test for ret not being an errorcoe.

>>               return ubi_open_volume(0, dev, mode);
>>
>>       /* ubiX_Y method */

If ret is an errorcode, the flow continues.

As parsing the number failed, the code checks if the first character
(name + 3) is an underscore or colon:

       if (*endptr == '_' && isdigit(endptr[1])) {


                vol = simple_strtoul(endptr + 1, &endptr, 0);
                if (*endptr != '\0')
                        return ERR_PTR(-EINVAL);
                return ubi_open_volume(dev, vol, mode);
        }

        /* ubiX:NAME method */
        if ((*endptr == ':' || *endptr == '!') && endptr[1] != '\0')
                return ubi_open_volume_nm(dev, ++endptr, mode);

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds