diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index d53857b..d6e076c 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -85,6 +85,10 @@
 	atomic_set(&req->wb_complete, 0);
 	req->wb_index	= page->index;
 	page_cache_get(page);
+	BUG_ON(PagePrivate(page));
+	BUG_ON(!PageLocked(page));
+	BUG_ON(page->mapping->host != inode);
+	SetPagePrivate(page);
 	req->wb_offset  = offset;
 	req->wb_pgbase	= offset;
 	req->wb_bytes   = count;
@@ -147,8 +151,10 @@
  */
 void nfs_clear_request(struct nfs_page *req)
 {
-	if (req->wb_page) {
-		page_cache_release(req->wb_page);
+	struct page *page = req->wb_page;
+	if (page != NULL) {
+		ClearPagePrivate(page);
+		page_cache_release(page);
 		req->wb_page = NULL;
 	}
 }