Patch "mm/hwpoison: fix fail isolate hugetlbfs page w/ refcount held" has been added to the 4.1-stable tree

This is a note to let you know that I've just added the patch titled

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

to the 4.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
mm-hwpoison-fix-fail-isolate-hugetlbfs-page-w-refcount-held.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Wanpeng Li <[email protected]>
Date: Fri, 14 Aug 2015 15:34:59 -0700
Subject: mm/hwpoison: fix fail isolate hugetlbfs page w/ refcount held

From: Wanpeng Li <[email protected]>

commit 036138080a4376e5f3e5d0cca8ac99084c5cf06e upstream.

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.

---
 mm/memory-failure.c |   13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

@@ -1589,13 +1589,12 @@ static int soft_offline_huge_page(struct
 	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 {
+	/*
+	 * get_any_page() and isolate_huge_page() takes a refcount each,
+	 * so need to drop one here.
+	 */
+	put_page(hpage);
+	if (!ret) {
 		pr_info("soft offline: %#lx hugepage failed to isolate\n", pfn);
 		return -EBUSY;
 	}

Patches currently in stable-queue which might be from [email protected] are

queue-4.1/mm-hwpoison-fix-fail-isolate-hugetlbfs-page-w-refcount-held.patch queue-4.1/mm-hwpoison-fix-page-refcount-of-unknown-non-lru-page.patch