From 2dd160c9886d564d6c6321ca468ecec85744de8e Mon Sep 17 00:00:00 2001 From: Muchun Song Date: Thu, 4 Feb 2021 18:32:03 -0800 Subject: [PATCH] mm: hugetlbfs: fix cannot migrate the fallocated HugeTLB page 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/20210115124942.46403-3-songmuchun@bytedance.com Fixes: 70c3547e36f5 (hugetlbfs: add hugetlbfs_fallocate()) Signed-off-by: Muchun Song Acked-by: Michal Hocko Reviewed-by: Mike Kravetz Reviewed-by: Oscar Salvador Cc: David Hildenbrand Cc: Yang Shi Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- fs/hugetlbfs/inode.c | 3 ++- include/linux/hugetlb.h | 3 +++ mm/hugetlb.c | 2 +- 3 files changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index 253b03451b72..ba1909b887ef 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -665,8 +665,9 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset, mutex_unlock(&hugetlb_fault_mutex_table[hash]); + set_page_huge_active(page); /* - * page_put due to reference from alloc_huge_page() + * put_page() due to reference from alloc_huge_page() * unlock_page because locked by add_to_page_cache() */ put_page(page); diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 6b8a7b654771..4e4c35a6bfc5 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -502,6 +502,9 @@ static inline void hugetlb_count_sub(long l, struct mm_struct *mm) { atomic_long_sub(l, &mm->hugetlb_usage); } + +void set_page_huge_active(struct page *page); + #else /* CONFIG_HUGETLB_PAGE */ struct hstate {}; #define alloc_huge_page(v, a, r) NULL diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 52b5e0e026d6..3cab92a4057d 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1215,7 +1215,7 @@ 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]);