Commit 585fc0d2 authored by Muchun Song's avatar Muchun Song Committed by Linus Torvalds

mm: hugetlbfs: fix cannot migrate the fallocated HugeTLB page

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: 70c3547e (hugetlbfs: add hugetlbfs_fallocate())
Signed-off-by: default avatarMuchun Song <songmuchun@bytedance.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Reviewed-by: default avatarMike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: default avatarOscar Salvador <osalvador@suse.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 5c279c4c
......@@ -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);
......
......@@ -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 {};
......
......@@ -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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