From: Wanpeng Li <wanpeng.li@hotmail.com>
Date: Fri, 14 Aug 2015 22:34:56 +0000 (-0700)
Subject: mm/hwpoison: fix page refcount of unknown non LRU page
X-Git-Tag: microblaze-4.7-rc1~1602^2~10
X-Git-Url: http://git.monstr.eu/?a=commitdiff_plain;h=4f32be677b124a49459e2603321c7a5605ceb9f8;p=linux-2.6-microblaze.git

mm/hwpoison: fix page refcount of unknown non LRU page

After trying to drain pages from pagevec/pageset, we try to get reference
count of the page again, however, the reference count of the page is not
reduced if the page is still not on LRU list.

Fix it by adding the put_page() to drop the page reference which is from
__get_any_page().

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>
---

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index ea5a93659488..81c20a7c9fa7 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1538,6 +1538,8 @@ static int get_any_page(struct page *page, unsigned long pfn, int flags)
 		 */
 		ret = __get_any_page(page, pfn, 0);
 		if (!PageLRU(page)) {
+			/* Drop page reference which is from __get_any_page() */
+			put_page(page);
 			pr_info("soft_offline: %#lx: unknown non LRU page type %lx\n",
 				pfn, page->flags);
 			return -EIO;