USB detach trouble?

[Thomas Klausner <wiz%NetBSD.org@localhost>]

Does anyone else see trouble when unplugging USB devices in -current?

I had two meetings with ddb directly after unplugging USB mass media
with an amd64 kernel from May 23. I'll upgrade now.

One I saw was:
Mutex error: mutex_vector_enter: locking against myself
lock address : 0xffff80005f56a950
current cpu: 7
current lwp : 0xffff800061f89800
owner field : 0xffff800061f89800 wait/spin: 0/0
panic: lock error

Backtrace from the one where I had access to console was
breakpoint
panic
lockdebug_abort
mutex_vector_enter
mountd_set_exports_list
nfs_export_update_30
vfs_hooks_reexport
do_sys_mount
sys___mount50
syscall

 Thomas