Re: [PATCH] bcachefs: Fix format specifier in validate_bset_keys()

[Kent Overstreet]

On Mon, Apr 22, 2024 at 02:47:32PM +0200, Geert Uytterhoeven wrote:
> Hi Kent,
> 
> On Wed, Apr 17, 2024 at 12:09 AM Kent Overstreet
> <kent.overstreet@xxxxxxxxx> wrote:
> > On Tue, Apr 16, 2024 at 08:16:02AM -0700, Nathan Chancellor wrote:
> > > When building for 32-bit platforms, for which size_t is 'unsigned int',
> > > there is a warning from a format string in validate_bset_keys():
> > >
> > >   fs/bcachefs/btree_io.c: In function 'validate_bset_keys':
> > >   fs/bcachefs/btree_io.c:891:34: error: format '%lu' expects argument of type 'long unsigned int', but argument 12 has type 'unsigned int' [-Werror=format=]
> > >     891 |                                  "bad k->u64s %u (min %u max %lu)", k->u64s,
> > >         |                                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > >   fs/bcachefs/btree_io.c:603:32: note: in definition of macro 'btree_err'
> > >     603 |                                msg, ##__VA_ARGS__);                     \
> > >         |                                ^~~
> > >   fs/bcachefs/btree_io.c:887:21: note: in expansion of macro 'btree_err_on'
> > >     887 |                 if (btree_err_on(!bkeyp_u64s_valid(&b->format, k),
> > >         |                     ^~~~~~~~~~~~
> > >   fs/bcachefs/btree_io.c:891:64: note: format string is defined here
> > >     891 |                                  "bad k->u64s %u (min %u max %lu)", k->u64s,
> > >         |                                                              ~~^
> > >         |                                                                |
> > >         |                                                                long unsigned int
> > >         |                                                              %u
> > >   cc1: all warnings being treated as errors
> > >
> > > BKEY_U64s is size_t so the entire expression is promoted to size_t. Use
> > > the '%zu' specifier so that there is no warning regardless of the width
> > > of size_t.
> > >
> > > Fixes: 031ad9e7dbd1 ("bcachefs: Check for packed bkeys that are too big")
> > > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > > Closes: https://lore.kernel.org/oe-kbuild-all/202404130747.wH6Dd23p-lkp@xxxxxxxxx/
> > > Closes: https://lore.kernel.org/oe-kbuild-all/202404131536.HdAMBOVc-lkp@xxxxxxxxx/
> > > Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
> >
> > Thanks, applied
> 
> This is still not fixed in today's linux-next, while the issue is now
> causing breakage on several 32-bit defconfs in v6.9-rc5.

Apologies, I just neglected to update my for-next branch, it's in now.