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.

Fixes: 70c3547e36f5 (hugetlbfs: add hugetlbfs_fallocate()) Signed-off-by: Muchun Song songmuchun@bytedance.com Acked-by: Michal Hocko mhocko@suse.com Reviewed-by: Mike Kravetz mike.kravetz@oracle.com Reviewed-by: Oscar Salvador osalvador@suse.de Cc: stable@vger.kernel.org --- fs/hugetlbfs/inode.c | 3 ++- include/linux/hugetlb.h | 2 ++ mm/hugetlb.c | 2 +- 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index b5c109703daa..21c20fd5f9ee 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -735,9 +735,10 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,

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); diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index ebca2ef02212..b5807f23caf8 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -770,6 +770,8 @@ static inline void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, } #endif

+void set_page_huge_active(struct page *page); + #else /* CONFIG_HUGETLB_PAGE */ struct hstate {};

diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 1f3bf1710b66..4741d60f8955 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1348,7 +1348,7 @@ 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]);