mount_ext2fs returning ENODEV on 6.1

[Perry Hutchison]

What am I doing wrong?

# ll /dev/ad0s7
crw-r-----  1 root  operator    0,  93 Sep  4 02:30 /dev/ad0s7
# file -s /dev/ad0s7
/dev/ad0s7: Linux rev 1.0 ext2 filesystem data
# grep -w ad0s7 /etc/fstab
/dev/ad0s7      /linux          ext2fs  ro              0       0
# ll -d /linux
drwxr-xr-x  2 root  wheel  512 Aug 24 12:09 /linux
# mount /linux
mount_ext2fs: /dev/ad0s7: Operation not supported by device
# uname -a
FreeBSD fbsd61 6.1-RELEASE FreeBSD 6.1-RELEASE #0: Sun May  7 04:32:43 UTC 2006     root at opus.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC  i386