Re: [PATCH] btrfs: Fix PAGE_SIZE format specifier in open_ctree()

[David Sterba <dsterba@suse.cz>]

On Thu, Sep 25, 2025 at 07:03:04PM -0400, Nathan Chancellor wrote:
> There is an instance of -Wformat when targeting 32-bit architectures due
> to using a 'size_t' specifier (which is 'unsigned int' for 32-bit
> platforms) to print PAGE_SIZE:
> 
>   In file included from fs/btrfs/compression.h:17,
>                    from fs/btrfs/extent_io.h:15,
>                    from fs/btrfs/locking.h:13,
>                    from fs/btrfs/ctree.h:19,
>                    from fs/btrfs/disk-io.c:22:
>   fs/btrfs/disk-io.c: In function 'open_ctree':
>   include/linux/kern_levels.h:5:25: error: format '%zu' expects argument of type 'size_t', but argument 4 has type 'long unsigned int' [-Werror=format=]
>   ...
>   fs/btrfs/disk-io.c:3398:17: note: in expansion of macro 'btrfs_warn'
>    3398 |                 btrfs_warn(fs_info,
>         |                 ^~~~~~~~~~
> 
> PAGE_SIZE is consistently defined as an 'unsigned long' in
> include/vsdo/page.h so use '%lu' to clear up the warning.
> 
> Fixes: 98077f7f2180 ("btrfs: enable experimental bs > ps support")
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Thanks, I'm planning to send it as fixup once the main pull request is
merged, until then it'll be in linux-next.