if ((rpc = server->client) != NULL)
if (!IS_ERR(rpc))
nfs_umount_begin(struct super_block *sb){	struct nfs_server *server = NFS_SB(sb);	struct rpc_clnt	*rpc;	/* -EIO all pending I/O */	if ((rpc = server->client) != NULL)		rpc_killall_tasks(rpc);}