New bcache compiler warning (was: Re: bcache: Minor fixes from kbuild robot)

[Geert Uytterhoeven <geert@linux-m68k.org>]

On Fri, Feb 14, 2014 at 8:04 PM, Linux Kernel Mailing List
<linux-kernel@vger.kernel.org> wrote:
>    bcache: Minor fixes from kbuild robot

> diff --git a/drivers/md/bcache/bset.c b/drivers/md/bcache/bset.c
> index 4f6b594..3f74b4b 100644
> --- a/drivers/md/bcache/bset.c
> +++ b/drivers/md/bcache/bset.c
> @@ -23,7 +23,7 @@ void bch_dump_bset(struct btree_keys *b, struct bset *i, unsigned set)
>         for (k = i->start; k < bset_bkey_last(i); k = next) {
>                 next = bkey_next(k);
>
> -               printk(KERN_ERR "block %u key %zi/%u: ", set,
> +               printk(KERN_ERR "block %u key %li/%u: ", set,
>                        (uint64_t *) k - i->d, i->keys);
>
>                 if (b->ops->key_dump)

On 32-bit (m68k):
drivers/md/bcache/bset.c: In function ‘bch_dump_bset’:
drivers/md/bcache/bset.c:27: warning: format ‘%li’ expects type ‘long
int’, but argument 3 has type ‘int’

What are you trying to print here? It looks a bit strange to me.
Technically, the difference between two pointers is of type ptrdiff_.
The kernel had

typedef __kernel_ptrdiff_t      ptrdiff_t;

and

#if __BITS_PER_LONG != 64
typedef unsigned int    __kernel_size_t;
typedef int             __kernel_ssize_t;
typedef int             __kernel_ptrdiff_t;
#else
typedef __kernel_ulong_t __kernel_size_t;
typedef __kernel_long_t __kernel_ssize_t;
typedef __kernel_long_t __kernel_ptrdiff_t;
#endif

So I'd expect "%zi" to be the right way, and a quick test compile on
32-bit (m68k)
and 64-bit (amd64) comfirms that. What was wrong with it?

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@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