NFSv4.1 fix page number calculation bug for filelayout decode buffers

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index b5d4515..38512bc 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -587,7 +587,7 @@
 
 	/* allocate pages for xdr post processing */
 	max_resp_sz = server->nfs_client->cl_session->fc_attrs.max_resp_sz;
-	max_pages = max_resp_sz >> PAGE_SHIFT;
+	max_pages = nfs_page_array_len(0, max_resp_sz);
 
 	pages = kcalloc(max_pages, sizeof(struct page *), gfp_flags);
 	if (!pages)