Commit 03613808 authored Aug 14, 2015 by Wanpeng Li Committed by Linus Torvalds Aug 14, 2015

mm/hwpoison: fix fail isolate hugetlbfs page w/ refcount held



Hugetlbfs pages will get a refcount in get_any_page() or
madvise_hwpoison() if soft offlining through madvise.  The refcount which
is held by the soft offline path should be released if we fail to isolate
hugetlbfs pages.

Fix it by reducing the refcount for both isolation success and failure.

Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: <stable@vger.kernel.org>	[3.9+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 4f32be67

mm/memory-failure.c

+6 −7

Original line number	Diff line number	Diff line
		@@ -1569,13 +1569,12 @@ static int soft_offline_huge_page(struct page *page, int flags)
		unlock_page(hpage);

		ret = isolate_huge_page(hpage, &pagelist);
		if (ret) {
		/*
		* get_any_page() and isolate_huge_page() takes a refcount each,
		* so need to drop one here.
		*/
		put_page(hpage);
		} else {
		if (!ret) {
		pr_info("soft offline: %#lx hugepage failed to isolate\n", pfn);
		return -EBUSY;
		}