Weird problem mounting a cdrom, ktrace "fixed" it?

[Andy Ruhl <acruhl%gmail.com@localhost>]

This machine is a Seagate Dockstar, which is a version of a Sheevaplug.

I have a USB cdrom drive and I had tried a few times to mount a cd and
I kept getting a "read-only" error, which is weird since we know that
a cdrom is read-only already. Sometimes I got "invalid argument" as
well, but not always. I don't know why I got one error or the other.

Anyway, I wanted to start looking into it a bit harder, and using
ktrace "fixed" the problem:

root@dockstar:~ # mount -t cd9660 /dev/cd0a /mnt
mount_cd9660: /dev/cd0a on /mnt: Read-only file system
root@dockstar:~ # ktrace mount -t cd9660 /dev/cd0a /mnt
root@dockstar:~ # mount
/dev/sd0a on / type ffs (log, local)
tmpfs on /dev type tmpfs (union, local)
/dev/sd0f on /usr type ffs (log, local)
/dev/sd0g on /home type ffs (log, local)
procfs on /proc type procfs (local)
kernfs on /kern type kernfs (local)
/dev/cd0a on /mnt type cd9660 (read-only, local)

From here on, I can mount the CD without using ktrace anymore
(probably until I reboot?).

What can I do to try to figure this out? I've got the ktrace file if that helps.

root@dockstar:~ # uname -a
NetBSD dockstar 5.99.54 NetBSD 5.99.54 (DOCKSTAR.JUL9_2011) #2: Sat
Jul  9 08:21:58 MST 2011
root@foghorn:/usr/obj-evbarm/sys/arch/evbarm/compile/DOCKSTAR.JUL9_2011
evbarm

Andy