Re: CIFS kernel module bug

From: Jeff Layton
Date: Fri Sep 30 2011 - 14:04:18 EST


On Fri, 30 Sep 2011 14:58:58 +0100
Anton Altaparmakov <aia21@xxxxxxxxx> 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 versaâ
>
> 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@xxxxxxxxx>
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