From bb5b8589767a300014ba21c5984e6a4d15f0702d Mon Sep 17 00:00:00 2001
From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Date: Thu, 14 Jan 2016 15:21:43 -0800
Subject: mm: make sure isolate_lru_page() is never called for tail page

The VM_BUG_ON_PAGE() would catch such cases if any still exists.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/vmscan.c b/mm/vmscan.c
index bb0cbd4..108bd11 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1426,6 +1426,7 @@ int isolate_lru_page(struct page *page)
 	int ret = -EBUSY;
 
 	VM_BUG_ON_PAGE(!page_count(page), page);
+	VM_BUG_ON_PAGE(PageTail(page), page);
 
 	if (PageLRU(page)) {
 		struct zone *zone = page_zone(page);
-- 
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