Function vn_fullpath

freebsd/kern/vfs_cache.c:2957–2984

* Retrieve the full filesystem path that correspond to a vnode from the name * cache (if available) */

 * cache (if available)
 */
int
vn_fullpath(struct vnode *vp, char **retbuf, char **freebuf)
{
	struct pwd *pwd;
	char *buf;
	size_t buflen;
	int error;

	if (__predict_false(vp == NULL))
		return (EINVAL);

	buflen = MAXPATHLEN;
	buf = malloc(buflen, M_TEMP, M_WAITOK);
	vfs_smr_enter();
	pwd = pwd_get_smr();
	error = vn_fullpath_any_smr(vp, pwd->pwd_rdir, buf, retbuf, &buflen, 0);
	VFS_SMR_ASSERT_NOT_ENTERED();
	if (error < 0) {
		pwd = pwd_hold(curthread);
		error = vn_fullpath_any(vp, pwd->pwd_rdir, buf, retbuf, &buflen);
		pwd_drop(pwd);
	}
	if (error == 0)
		*freebuf = buf;
	else
		free(buf, M_TEMP);
	return (error);
}

/*
 * This function is similar to vn_fullpath, but it attempts to lookup the