On Mon, Feb 3, 2014 at 2:47 PM, Geert Uytterhoeven [off-list ref] wrote:

On Wed, Jan 15, 2014 at 12:06 PM, Joe Perches [off-list ref] wrote:

quoted

On Wed, 2014-01-15 at 10:06 +0100, Geert Uytterhoeven wrote:

quoted

drivers/md/bcache/btree.c: In function ‘insert_u64s_remaining’:
drivers/md/bcache/btree.c:1816: warning: comparison of distinct pointer types lacks a cast

[]

quoted

diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c

[]

quoted

@@ -1813,7 +1813,7 @@ static size_t insert_u64s_remaining(struct btree *b)
      if (b->keys.ops->is_extents)
              ret -= KEY_MAX_U64S;

-     return max(ret, 0L);
+     return max_t(ssize_t, ret, 0L);

why not
        return max(ret, 0);

Indeed, that also works, on both 32-bit and 64-bit.
Will resend, now all the issues moved from -next to Linus' tree.

However, sparse doesn't like it, so we'll have to go for v1?

From kbuild test robot fengguang.wu@intel.com:

quoted

drivers/md/bcache/btree.c:1816:16: sparse: incompatible types in comparison expression (different type sizes)

   In file included from arch/x86/include/asm/percpu.h:44:0,
                    from arch/x86/include/asm/preempt.h:5,
                    from include/linux/preempt.h:18,
                    from include/linux/spinlock.h:50,
                    from include/linux/wait.h:8,
                    from include/linux/fs.h:6,
                    from include/linux/highmem.h:4,
                    from include/linux/bio.h:23,
                    from drivers/md/bcache/bcache.h:181,
                    from drivers/md/bcache/btree.c:23:
   drivers/md/bcache/btree.c: In function 'insert_u64s_remaining':
   include/linux/kernel.h:718:17: warning: comparison of distinct
pointer types lacks a cast [enabled by default]
     (void) (&_max1 == &_max2);  \
                    ^
   drivers/md/bcache/btree.c:1816:9: note: in expansion of macro 'max'
     return max(ret, 0);
            ^

vim +1816 drivers/md/bcache/btree.c

  1800                                                status);
  1801                  return true;
  1802          } else
  1803                  return false;
  1804  }
  1805
  1806  static size_t insert_u64s_remaining(struct btree *b)
  1807  {
  1808          ssize_t ret = bch_btree_keys_u64s_remaining(&b->keys);
  1809
  1810          /*
  1811           * Might land in the middle of an existing extent and
have to split it
  1812           */
  1813          if (b->keys.ops->is_extents)
  1814                  ret -= KEY_MAX_U64S;
  1815

1816          return max(ret, 0);

  1817  }
  1818
  1819  static bool bch_btree_insert_keys(struct btree *b, struct btree_op *op,
  1820                                    struct keylist *insert_keys,
  1821                                    struct bkey *replace_key)
  1822  {
  1823          bool ret = false;
  1824          int oldsize = bch_count_data(&b->keys);

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