kern/38956: rb tree corruption?

[martin%duskware.de@localhost]

>Number:         38956
>Category:       kern
>Synopsis:       rb tree corruption?
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Jun 15 12:40:00 +0000 2008
>Originator:     Martin Husemann
>Release:        NetBSD 4.99.64
>Organization:
The NetBSD Foundation, Inc.
>Environment:
System: NetBSD night-porter.duskware.de 4.99.64 NetBSD 4.99.64 (PORTER) #51: 
Sat Jun 14 21:13:47 CEST 2008 
martin%night-porter.duskware.de@localhost:/usr/src/sys/arch/i386/compile/PORTER 
i386
Architecture: i386
Machine: i386
>Description:

Suddenly happened after ~1 day uptime on a SMP machine. It is used as a NFS
server and a client just had done a "make cleandir" on a part of the source
tree.

(manually transcribed)

panic: kernel diagnostic assertion "!RB_SENTINEL_P(brother)" failed: file 
"../../../../../../lib/libkern/rb.c", line 809

trace:
rb_tree_iterate()
uvm_pagefree()
genfs_do_putpages()
genfs_putpages()
VOP_PUTPAGES()
uvm_vnp_setsize()
ffs_truncate()
ufs_inactive()
VOP_INACTIVE()
vrelel()
vrele()
handle_workitem_remove()
softdep_process_worklist()
sched_sync()


>How-To-Repeat:
no idea, just happened once

>Fix:
n/a