return err;
 }
 
+void __nfs4_read_done_cb(struct nfs_read_data *data)
+{
+       nfs_invalidate_atime(data->inode);
+}
+
 static int nfs4_read_done_cb(struct rpc_task *task, struct nfs_read_data *data)
 {
        struct nfs_server *server = NFS_SERVER(data->inode);
                return -EAGAIN;
        }
 
-       nfs_invalidate_atime(data->inode);
+       __nfs4_read_done_cb(data);
        if (task->tk_status > 0)
                renew_lease(server, data->timestamp);
        return 0;
        if (!nfs4_sequence_done(task, &data->res.seq_res))
                return -EAGAIN;
 
-       return data->read_done_cb(task, data);
+       return data->read_done_cb ? data->read_done_cb(task, data) :
+                                   nfs4_read_done_cb(task, data);
 }
 
 static void nfs4_proc_read_setup(struct nfs_read_data *data, struct rpc_message *msg)
 {
        if (!nfs4_sequence_done(task, &data->res.seq_res))
                return -EAGAIN;
-       return data->write_done_cb(task, data);
+       return data->write_done_cb ? data->write_done_cb(task, data) :
+               nfs4_write_done_cb(task, data);
 }
 
 /* Reset the the nfs_write_data to send the write to the MDS. */
 
 {
        struct inode *inode = lseg->pls_layout->plh_inode;
 
-       BUG_ON(test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
+       WARN_ON(test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
        list_del_init(&lseg->pls_list);
        if (list_empty(&lseg->pls_layout->plh_segs)) {
                set_bit(NFS_LAYOUT_DESTROYED, &lseg->pls_layout->plh_flags);
        pgio->pg_test = (ld && ld->pg_test) ? pnfs_write_pg_test : NULL;
 }
 
+/*
+ * Called by non rpc-based layout drivers
+ */
+int
+pnfs_ld_write_done(struct nfs_write_data *data)
+{
+       int status;
+
+       if (!data->pnfs_error) {
+               pnfs_set_layoutcommit(data);
+               data->mds_ops->rpc_call_done(&data->task, data);
+               data->mds_ops->rpc_release(data);
+               return 0;
+       }
+
+       dprintk("%s: pnfs_error=%d, retry via MDS\n", __func__,
+               data->pnfs_error);
+       status = nfs_initiate_write(data, NFS_CLIENT(data->inode),
+                                   data->mds_ops, NFS_FILE_SYNC);
+       return status ? : -EAGAIN;
+}
+EXPORT_SYMBOL_GPL(pnfs_ld_write_done);
+
 enum pnfs_try_status
 pnfs_try_to_write_data(struct nfs_write_data *wdata,
                        const struct rpc_call_ops *call_ops, int how)
        return trypnfs;
 }
 
+/*
+ * Called by non rpc-based layout drivers
+ */
+int
+pnfs_ld_read_done(struct nfs_read_data *data)
+{
+       int status;
+
+       if (!data->pnfs_error) {
+               __nfs4_read_done_cb(data);
+               data->mds_ops->rpc_call_done(&data->task, data);
+               data->mds_ops->rpc_release(data);
+               return 0;
+       }
+
+       dprintk("%s: pnfs_error=%d, retry via MDS\n", __func__,
+               data->pnfs_error);
+       status = nfs_initiate_read(data, NFS_CLIENT(data->inode),
+                                  data->mds_ops);
+       return status ? : -EAGAIN;
+}
+EXPORT_SYMBOL_GPL(pnfs_ld_read_done);
+
 /*
  * Call the appropriate parallel I/O subsystem read function.
  */
 
 bool pnfs_roc_drain(struct inode *ino, u32 *barrier);
 void pnfs_set_layoutcommit(struct nfs_write_data *wdata);
 int pnfs_layoutcommit_inode(struct inode *inode, bool sync);
+int pnfs_ld_write_done(struct nfs_write_data *);
+int pnfs_ld_read_done(struct nfs_read_data *);
 
 /* pnfs_dev.c */
 struct nfs4_deviceid_node {