Re: [PATCH] mm/hugetlb: Fix build failure with HUGETLB_PAGE but not HUGEBTLBFS

On Tue, 17 Mar 2020 08:04:14 +0000 (UTC) Christophe Leroy [off-list ref] wrote:

When CONFIG_HUGETLB_PAGE is set but not CONFIG_HUGETLBFS, the
following build failure is encoutered:

In file included from arch/powerpc/mm/fault.c:33:0:
./include/linux/hugetlb.h: In function 'hstate_inode':
./include/linux/hugetlb.h:477:9: error: implicit declaration of function 'HUGETLBFS_SB' [-Werror=implicit-function-declaration]
  return HUGETLBFS_SB(i->i_sb)->hstate;
         ^
./include/linux/hugetlb.h:477:30: error: invalid type argument of '->' (have 'int')
  return HUGETLBFS_SB(i->i_sb)->hstate;
                              ^

Gate hstate_inode() with CONFIG_HUGETLBFS instead of CONFIG_HUGETLB_PAGE.

Reported-by: kbuild test robot <redacted>
Link: https://patchwork.ozlabs.org/patch/1255548/#2386036
Fixes: a137e1cc6d6e ("hugetlbfs: per mount huge page sizes")

A 12 year old build error?  If accurate, that has to be a world record.

Cc: stable@vger.kernel.org

I think I'll remove this.  Obviously nobody is suffering from this problem!