queue/mm-hugetlb-fix-build-failure-with-HUGETLB_PAGE-but-n.patch

From dc54142d8c9bbed186e20a782d07fb90f37767f8 Mon Sep 17 00:00:00 2001
From: Christophe Leroy <christophe.leroy@c-s.fr>
Date: Wed, 1 Apr 2020 21:11:54 -0700
Subject: [PATCH] mm/hugetlb: fix build failure with HUGETLB_PAGE but not
 HUGEBTLBFS

commit bb297bb2de517e41199185021f043bbc5d75b377 upstream.

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.

Fixes: a137e1cc6d6e ("hugetlbfs: per mount huge page sizes")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Nishanth Aravamudan <nacc@us.ibm.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Adam Litke <agl@us.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Link: http://lkml.kernel.org/r/7e8c3a3c9a587b9cd8a2f146df32a421b961f3a2.1584432148.git.christophe.leroy@c-s.fr
Link: https://patchwork.ozlabs.org/patch/1255548/#2386036
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[PG: no-op is a macro and not a stub fcn back in v5.2.x code base.]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index edf476c8cfb9..aa0553357534 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -316,10 +316,15 @@ 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
+#define hstate_inode(i)				NULL
 static inline struct file *
 hugetlb_file_setup(const char *name, size_t size, vm_flags_t acctflag,
 		struct user_struct **user, int creat_flags,
@@ -397,11 +402,6 @@ 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));
@@ -616,7 +616,6 @@ struct hstate {};
 #define hstate_file(f) NULL
 #define hstate_sizelog(s) NULL
 #define hstate_vma(v) NULL
-#define hstate_inode(i) NULL
 #define page_hstate(page) NULL
 #define huge_page_size(h) PAGE_SIZE
 #define huge_page_mask(h) PAGE_MASK
-- 
2.7.4