port-amd64/40727: kernel trap on intensive filesystem operations (ffs_valloc: dup alloc)

[msorc%bigmir.net@localhost]

>Number:         40727
>Category:       port-amd64
>Synopsis:       kernel trap on intensive filesystem operations (ffs_valloc: 
>dup alloc)
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    port-amd64-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Feb 23 11:20:00 +0000 2009
>Originator:     Mykhaylo Sorochan
>Release:        5.0_RC2
>Organization:
>Environment:
NetBSD machine 5.0_RC2 NetBSD 5.0_RC2 (machine) #0: Mon Feb 23 11:47:13 EET 
2009 root@machine:/usr/src/sys/arch/amd64/compile/machine amd64
>Description:
System hangs on intensive file operations (e.g. package building, cvsup, etc.)
Effect was available on GENERIC kernel and custom build one.

Debug output:

dmode 9490 mode 9490 dgen 456ac4ca gen 456ac4ca
size 3fd3c536f5972c5 blocks a4fd96f85d48aeea
ino 2705088 ipref 2704133
panic: ffs_valloc: dup alloc
fatal breakpoint trap in supervisor mode
trap type 1 code 0 rip ffffffff80491aa5 cs 8 rflags 246 cr2 7f7ffd916144 cpl 0 
rsp ffff80004c78e790
Stopped in pid 343.1 (sh) at   netbsd:breakpoint+0x5:  leave
>How-To-Repeat:
cd /usr/pkgsrc/x11/qt4-libs
make install clean
Hangs after ~10 minutes
>Fix: