vfs_mountedon
int vfs_mountedon (struct vnode *); /* is a vfs mounted on vp */
if (vfs_mountedon(vp)) {
if ((error = vfs_mountedon(devvp)) != 0)
error = vfs_mountedon(volume->devvp);
error = vfs_mountedon(devvp);
error = vfs_mountedon(devvp);
if ((error = vfs_mountedon(devvp)))
error = vfs_mountedon(devvp);
error = vfs_mountedon(devvp);
if ((error = vfs_mountedon(devvp)))
error = vfs_mountedon(devvp);
error = vfs_mountedon(devvp);