NFS: Cache rpc_ops in struct nfs_pageio_descriptor

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h
index 9ac2dd1..db3194f 100644
--- a/include/linux/nfs_page.h
+++ b/include/linux/nfs_page.h
@@ -74,6 +74,7 @@
 	const struct nfs_pageio_ops *pg_ops;
 	int 			pg_ioflags;
 	int			pg_error;
+	const struct rpc_call_ops *pg_rpc_callops;
 	struct pnfs_layout_segment *pg_lseg;
 };