Re: [GIT PULL] bcachefs fixes for 6.11-rc6

[Nathan Chancellor]

On Tue, Sep 03, 2024 at 03:53:56PM +0200, Geert Uytterhoeven wrote:
> Hi Kent,
> 
> Replying here, as there is (again) no patch email to reply to to report issues.
> 
> noreply@xxxxxxxxxxxxxx is reporting several build failures[1] in linux-next:
> 
>     fs/bcachefs/sb-members.c: In function ‘bch2_sb_member_alloc’:
>     fs/bcachefs/sb-members.c:503:2: error: a label can only be part of
> a statement and a declaration is not a statement
>       503 |  unsigned nr_devices = max_t(unsigned, dev_idx + 1,
> c->sb.nr_devices);
>           |  ^~~~~~~~
>     fs/bcachefs/sb-members.c:505:2: error: expected expression before ‘struct’
>       505 |  struct bch_sb_field_members_v2 *mi =
> bch2_sb_field_get(c->disk_sb.sb, members_v2);
>           |  ^~~~~~
> 
> Apparently this fails with gcc-10 and older, but builds with gcc-11
> and gcc-12.

Just noting this also happens with clang. Depending on the version, it
is either a hard error like this or a warning (that gets upgraded to an
error with CONFIG_WERROR).

Clang 15:

  fs/bcachefs/sb-members.c:503:2: error: expected expression
          unsigned nr_devices = max_t(unsigned, dev_idx + 1, c->sb.nr_devices);
          ^
  fs/bcachefs/sb-members.c:507:42: error: use of undeclared identifier 'nr_devices'
                                       le16_to_cpu(mi->member_bytes) * nr_devices, sizeof(u64));
                                                                       ^
  include/linux/math.h:37:22: note: expanded from macro 'DIV_ROUND_UP'
  #define DIV_ROUND_UP __KERNEL_DIV_ROUND_UP
                       ^
  fs/bcachefs/sb-members.c:513:30: error: use of undeclared identifier 'nr_devices'
          c->disk_sb.sb->nr_devices = nr_devices;
                                      ^

Clang 19:

  fs/bcachefs/sb-members.c:503:2: error: label followed by a declaration is a C23 extension [-Werror,-Wc23-extensions]
    503 |         unsigned nr_devices = max_t(unsigned, dev_idx + 1, c->sb.nr_devices);
        |         ^

Cheers,
Nathan