kern/38034: kernel lock deadlock

[martin%duskware.de@localhost]

>Number:         38034
>Category:       kern
>Synopsis:       kernel lock deadlock
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Feb 15 06:40:00 +0000 2008
>Originator:     Martin Husemann
>Release:        NetBSD 4.99.54
>Organization:
>Environment:
System: dual i386, SMP kernel with DIAGNOSTIC, DEBUG and LOCKDEBUG
multiple raid-1 filesystems (including /), softdep, ffs

>Description:

Repeatable lockdebug panic on "shutdown -r":

Unmounting .... (/dev/raid0a):
Kernel lock error: _kernel_lock: spinout

Backtrace:
_kernel_lock()
sleepq_block()
iic_smbus_intr_thread() + 0x7a

Other CPU:
softdep_sync_metadata()
ffs_full_fsync()
ffs_fsync()
VOP_FSYNC()
vinvalbuf()
vclean()
vflush()
ffs_flushfiles()
softdep_flushfiles()
ffs_unmount()
VOP_UNMOUNT()
dounmount()

>How-To-Repeat:
Run "shutdown -r now" on my machine ;-}
>Fix:
n/a