From: Muchun Song <[email protected]>

commit 585fc0d2871c9318c949fbf45b1f081edd489e96 upstream.

If a new hugetlb page is allocated during fallocate it will not be
marked as active (set_page_huge_active) which will result in a later
isolate_huge_page failure when the page migration code would like to
move that page.  Such a failure would be unexpected and wrong.

Only export set_page_huge_active, just leave clear_page_huge_active as
static.  Because there are no external users.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 70c3547e36f5 (hugetlbfs: add hugetlbfs_fallocate())
Signed-off-by: Muchun Song <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Reviewed-by: Mike Kravetz <[email protected]>
Reviewed-by: Oscar Salvador <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Yang Shi <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 fs/hugetlbfs/inode.c    |    3 ++-
 include/linux/hugetlb.h |    2 ++
 mm/hugetlb.c            |    2 +-
 3 files changed, 5 insertions(+), 2 deletions(-)

--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -735,9 +735,10 @@ static long hugetlbfs_fallocate(struct f
 
                mutex_unlock(&hugetlb_fault_mutex_table[hash]);
 
+               set_page_huge_active(page);
                /*
                 * unlock_page because locked by add_to_page_cache()
-                * page_put due to reference from alloc_huge_page()
+                * put_page() due to reference from alloc_huge_page()
                 */
                unlock_page(page);
                put_page(page);
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -770,6 +770,8 @@ static inline void huge_ptep_modify_prot
 }
 #endif
 
+void set_page_huge_active(struct page *page);
+
 #else  /* CONFIG_HUGETLB_PAGE */
 struct hstate {};
 
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1349,7 +1349,7 @@ bool page_huge_active(struct page *page)
 }
 
 /* never called for tail page */
-static void set_page_huge_active(struct page *page)
+void set_page_huge_active(struct page *page)
 {
        VM_BUG_ON_PAGE(!PageHeadHuge(page), page);
        SetPagePrivate(&page[1]);


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