Re: [PATCH] adfs: add hexadecimal filetype suffix option

From: Andrew Morton
Date: Wed Mar 23 2011 - 16:58:46 EST


On Wed, 23 Mar 2011 21:36:48 +0100
Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:

> On Thu, Jan 20, 2011 at 00:49, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> > On Wed, 12 Jan 2011 18:07:23 +0000
> > Stuart Swales <stuart.swales.croftnuisk@xxxxxxxxx> wrote:
> >> From: Stuart Swales<stuart.swales.croftnuisk@xxxxxxxxx>
>
> >> +static inline int append_filetype_suffix(char *buf, __u16 filetype)
> >> +{
> >> + __ __ if ((__u16) -1 == filetype)
> >
> > unneeded cast.
>
> My compiler tends to disagree. On current mainline, it says:
>
> fs/adfs/adfs.h: In function ___append_filetype_suffix___:
> fs/adfs/adfs.h:115: warning: comparison is always false due to limited
> range of data type
>

hm, OK, I'll add a cast.

The code seems a bit fishy - it wants 0xffff but the comment says it's
handling a 12-bit quantity. Obviously the all-ones pattern has some
magical out-of-band meaning here, but it is not explained what that
meaning *is*. Perhaps that is described elsewhere.

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