CIFS kernel module bug

[Steve French]

On Fri, Sep 30, 2011 at 1:04 PM, Jeff Layton <jlayton at samba.org> wrote:
> On Fri, 30 Sep 2011 14:58:58 +0100
> Anton Altaparmakov <aia21 at cam.ac.uk> wrote:
>
>> Hi,
>>
>> Looking at the current kernel (in Linus' repository on github) there is a silly logic bug in the cifs module in fs/cifs/cifsfs.c::cifs_llseek() there is this bit of code:
>>
>>       /*
>>        * origin == SEEK_END || SEEK_DATA || SEEK_HOLE => we must revalidate
>>        * the cached file length
>>        */
>>       if (origin != SEEK_SET || origin != SEEK_CUR) {
>>
>> The logical or should be a logical and, i.e. this should be:
>>
>>       if (origin != SEEK_SET && origin != SEEK_CUR) {
>>
>> As the code is at present that line is ALWAYS true because origin is ALWAYS either != SEEK_SET or != SEEK_CUR as if it equals one it cannot equal the other and vice versa…
>>
>> So at the moment it always does the revalidation instead of only for SEEK_END, SEEK_DATA, and SEEK_HOLE.
>>
>> Best regards,
>>
>>       Anton
>
>
> Haha, good catch. Care to roll up a patch to fix that?
>
> --
> Jeff Layton <jlayton at samba.org>
>


Yes - obviously that code was wrong, fortunately not a disaster.
Thanks for pointing this out.  If you don't want to write up
the patch let us know and we will make the trivial fix.



-- 
Thanks,

Steve