vfs_unmountall1
while (vfs_unmountall1(curlwp, false, false) ||
while (vfs_unmountall1(curlwp, false, false) ||
while (vfs_unmountall1(curlwp, false, false) ||
while (vfs_unmountall1(l, false, false) ||
return vfs_unmountall1(l, true, true);
bool vfs_unmountall1(struct lwp *, bool, bool);