cmd_pfs_snapshot
int cmd_pfs_snapshot(const char *sel_path, const char *name, const char *label,
ecode = cmd_pfs_snapshot(sel_path, NULL, NULL, flags);
ecode = cmd_pfs_snapshot(sel_path, av[1], NULL, flags);
ecode = cmd_pfs_snapshot(sel_path, av[1], av[2], flags);