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 (file)
--- 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);