Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Tue, 17 Mar 2020 22:02:38 -0700
From:   Andrew Morton <akpm@linux-foundation.org>
To:     Christophe Leroy <christophe.leroy@c-s.fr>
Cc:     Mike Kravetz <mike.kravetz@oracle.com>,
        Nishanth Aravamudan <nacc@us.ibm.com>,
        Nick Piggin <npiggin@suse.de>, Adam Litke <agl@us.ibm.com>,
        Andi Kleen <ak@suse.de>, linux-kernel@vger.kernel.org,
        linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org
Subject: Re: [PATCH] mm/hugetlb: Fix build failure with HUGETLB_PAGE but not
 HUGEBTLBFS
Message-Id: <20200317220238.8344f8423327c8ae178fc63a@linux-foundation.org>
In-Reply-To: <7e8c3a3c9a587b9cd8a2f146df32a421b961f3a2.1584432148.git.christophe.leroy@c-s.fr>
References: <7e8c3a3c9a587b9cd8a2f146df32a421b961f3a2.1584432148.git.christophe.leroy@c-s.fr>
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Tue, 17 Mar 2020 08:04:14 +0000 (UTC) Christophe Leroy <christophe.leroy@c-s.fr> 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 <lkp@intel.com>
> 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!