From: Alexaner Zarochentsev <zam@namesys.com>

re-add to reiser4_releasepage mistakenly removed page_count check.  reiser4
uses extra page reference to protect page from detaching from the jnode.

Signed-off-by: Alexander Zarochentsev <zam@namesys.com>
Cc: Hans Reiser <reiser@namesys.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 fs/reiser4/as_ops.c |    5 +++++
 1 files changed, 5 insertions(+)

diff -puN fs/reiser4/as_ops.c~reiser4-re-add-page_count-check-to-reiser4_releasepage fs/reiser4/as_ops.c
--- a/fs/reiser4/as_ops.c~reiser4-re-add-page_count-check-to-reiser4_releasepage
+++ a/fs/reiser4/as_ops.c
@@ -292,6 +292,11 @@ int reiser4_releasepage(struct page *pag
 	if (PageDirty(page))
 		return 0;
 
+	/* extra page reference is used by reiser4 to protect
+	 * jnode<->page link from this ->releasepage(). */
+	if (page_count(page) > 3)
+		return 0;
+
 	/* releasable() needs jnode lock, because it looks at the jnode fields
 	 * and we need jload_lock here to avoid races with jload(). */
 	spin_lock_jnode(node);
_