From: Konstantin Khlebnikov <khlebnikov@openvz.org>
Date: Fri, 3 Feb 2012 23:37:13 +0000 (-0800)
Subject: mm: postpone migrated page mapping reset
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=35512ecaef03250fe50ad81430dd467f01d9a96b;p=linux-beck.git

mm: postpone migrated page mapping reset

Postpone resetting page->mapping until the final remove_migration_ptes().
Otherwise the expression PageAnon(migration_entry_to_page(entry)) does not
work.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/migrate.c b/mm/migrate.c
index 9871a56d82c3..df141f60289e 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -445,7 +445,6 @@ void migrate_page_copy(struct page *newpage, struct page *page)
 	ClearPageSwapCache(page);
 	ClearPagePrivate(page);
 	set_page_private(page, 0);
-	page->mapping = NULL;
 
 	/*
 	 * If any waiters have accumulated on the new page then
@@ -667,6 +666,7 @@ static int move_to_new_page(struct page *newpage, struct page *page,
 	} else {
 		if (remap_swapcache)
 			remove_migration_ptes(page, newpage);
+		page->mapping = NULL;
 	}
 
 	unlock_page(newpage);