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Commit b6e04c19 authored by Muchun Song's avatar Muchun Song Committed by Greg Kroah-Hartman
Browse files

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: 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>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent e06c6b69

fs/hugetlbfs/inode.c

+2 −1
Original line number Diff line number Diff line
@@ -654,9 +654,10 @@ 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);

include/linux/hugetlb.h

+3 −0
Original line number Diff line number Diff line
@@ -541,6 +541,9 @@ static inline void set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr 
	set_huge_pte_at(mm, addr, ptep, pte);

}

#endif



void set_page_huge_active(struct page *page);



#else	/* CONFIG_HUGETLB_PAGE */

struct hstate {};

#define alloc_huge_page(v, a, r) NULL

mm/hugetlb.c

+1 −1
Original line number Diff line number Diff line
@@ -1201,7 +1201,7 @@ 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]);