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Message-Id: <7e8c3a3c9a587b9cd8a2f146df32a421b961f3a2.1584432148.git.christophe.leroy@c-s.fr>
From:   Christophe Leroy <christophe.leroy@c-s.fr>
Subject: [PATCH] mm/hugetlb: Fix build failure with HUGETLB_PAGE but not
 HUGEBTLBFS
To:     Mike Kravetz <mike.kravetz@oracle.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Nishanth Aravamudan <nacc@us.ibm.com>,
        Nick Piggin <npiggin@suse.de>, Adam Litke <agl@us.ibm.com>,
        Andi Kleen <ak@suse.de>
Cc:     linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
        linux-mm@kvack.org
Date:   Tue, 17 Mar 2020 08:04:14 +0000 (UTC)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 include/linux/hugetlb.h | 19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 1e897e4168ac..dafb3d70ff81 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -390,7 +390,10 @@ static inline bool is_file_hugepages(struct file *file)
 	return is_file_shm_hugepages(file);
 }
 
-
+static inline struct hstate *hstate_inode(struct inode *i)
+{
+	return HUGETLBFS_SB(i->i_sb)->hstate;
+}
 #else /* !CONFIG_HUGETLBFS */
 
 #define is_file_hugepages(file)			false
@@ -402,6 +405,10 @@ hugetlb_file_setup(const char *name, size_t size, vm_flags_t acctflag,
 	return ERR_PTR(-ENOSYS);
 }
 
+static inline struct hstate *hstate_inode(struct inode *i)
+{
+	return NULL;
+}
 #endif /* !CONFIG_HUGETLBFS */
 
 #ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
@@ -472,11 +479,6 @@ extern unsigned int default_hstate_idx;
 
 #define default_hstate (hstates[default_hstate_idx])
 
-static inline struct hstate *hstate_inode(struct inode *i)
-{
-	return HUGETLBFS_SB(i->i_sb)->hstate;
-}
-
 static inline struct hstate *hstate_file(struct file *f)
 {
 	return hstate_inode(file_inode(f));
@@ -729,11 +731,6 @@ static inline struct hstate *hstate_vma(struct vm_area_struct *vma)
 	return NULL;
 }
 
-static inline struct hstate *hstate_inode(struct inode *i)
-{
-	return NULL;
-}
-
 static inline struct hstate *page_hstate(struct page *page)
 {
 	return NULL;
-- 
2.25.0