int autosync);
If C<autosync> is true, this enables autosync. Libguestfs will make a
-best effort attempt to run C<guestfs_sync> when the handle is closed
+best effort attempt to run C<guestfs_umount_all> followed by
+C<guestfs_sync> when the handle is closed
(also if the program exits without closing handles).
+This is disabled by default (except in guestfish where it is
+enabled by default).
+
This function returns 0 on success or -1 on error.
=head2 guestfs_set_busy