Re: [zfs] Mounting from (...) failed with error 19

On Wed, Oct 20, 2010 at 1:39 PM, Garrett Cooper <gcooper_at_freebsd.org> wrote:
> On Wed, Oct 20, 2010 at 12:45 PM, Peter Jeremy <peterjeremy_at_acm.org> wrote:
>> On 2010-Oct-20 10:50:38 +0400, KOT MATPOCKuH <matpockuh_at_gmail.com> wrote:
>>>> I fixed it with attached patch.
>>>Omg... Why You are using strcmp, but not strncmp(fs, "zfs", strlen("zfs"))?
>>
>> Can you explain why you think it should be strncmp() please.
>
> I'd say that strcmp is perfectly fine because zfs is a 3 character (4
> if you count NUL) string. The comparison logic is dang near the same:
>
> /*
>  * Compare strings.
>  */
> int
> strcmp(const char *s1, const char *s2)
> {
>        while (*s1 == *s2++)
>                if (*s1++ == '\0')
>                        return (0);
>        return (*(const unsigned char *)s1 - *(const unsigned char *)(s2 - 1));
> }
>
> int
> strncmp(const char *s1, const char *s2, size_t n)
> {
>
>        if (n == 0)
>                return (0);
>        do {
>                if (*s1 != *s2++)
>                        return (*(const unsigned char *)s1 -
>                                *(const unsigned char *)(s2 - 1));
>                if (*s1++ == '\0')
>                        break;
>        } while (--n != 0);
>        return (0);
> }
>
> Weird how n == 0 with strcmp returns 0...

s/strcmp/strncmp/

-Garrett