Kernel panic when accessing ZFS-Filesystem via NFS

Hi,

I'm getting the following crash on the NFS server with -CURRENT (r193229)
as soon as I try to access a file on a ZFS filesystem via NFS:

#0  doadump () at pcpu.h:246
246     pcpu.h: No such file or directory.
        in pcpu.h
(kgdb) #0  doadump () at pcpu.h:246
#1  0x80562773 in boot (howto=260) at
/usr/src/sys/kern/kern_shutdown.c:420
#2  0x8056297e in panic (fmt=Variable "fmt" is not available.
) at /usr/src/sys/kern/kern_shutdown.c:576
#3  0x807b488c in trap_fatal (frame=0xfcc95718, eva=1660)
    at /usr/src/sys/i386/i386/trap.c:933
#4  0x807b4af0 in trap_pfault (frame=0xfcc95718, usermode=0, eva=1660)
    at /usr/src/sys/i386/i386/trap.c:846
#5  0x807b5492 in trap (frame=0xfcc95718) at
/usr/src/sys/i386/i386/trap.c:528
#6  0x8079ceeb in calltrap () at /usr/src/sys/i386/i386/exception.s:165
#7  0x8053d1bd in prison_priv_check (cred=0x85fe7000, priv=334)
    at /usr/src/sys/kern/kern_jail.c:3315
#8  0x8055631e in priv_check_cred (cred=0x85fe7000, priv=334, flags=0)
    at /usr/src/sys/kern/kern_priv.c:93
#9  0x8514412c in secpolicy_fs_owner () from /boot/kernel/zfs.ko
#10 0x85144657 in secpolicy_vnode_access () from /boot/kernel/zfs.ko
#11 0x851bfc5b in zfs_zaccess () from /boot/kernel/zfs.ko
#12 0x851bfeeb in zfs_zaccess_rwx () from /boot/kernel/zfs.ko
#13 0x851d55a4 in zfs_freebsd_access () from /boot/kernel/zfs.ko
#14 0x807bf282 in VOP_ACCESS_APV (vop=0x85238640, a=0xfcc958cc)
    at vnode_if.c:571
#15 0x806e8057 in nfsrv_access (vp=0x80, accmode=-2062450688, 
    cred=0x85fe7000, rdonly=0, override=0) at vnode_if.h:254
#16 0x806e87f1 in nfsrv3_access (nfsd=0xfcc95a9c, slp=0x0,
mrq=0xfcc95a94)
    at /usr/src/sys/nfsserver/nfs_serv.c:238
#17 0x806f65a5 in nfssvc_program (rqst=0x86080800, xprt=0x85fe9e00)
    at /usr/src/sys/nfsserver/nfs_srvkrpc.c:410
#18 0x8071658f in svc_run_internal (pool=0x84d9e500, ismaster=1)
    at /usr/src/sys/rpc/svc.c:883
#19 0x807173fd in svc_run (pool=0x84d9e500) at
/usr/src/sys/rpc/svc.c:1223
#20 0x806f5f6d in nfssvc_nfsd (td=Variable "td" is not available.
)
    at /usr/src/sys/nfsservc.c:199
#22 0x806f8158 in nfssvc (td=0x8549fb40, uap=0xfcc95cf8)
    at /usr/src/sys/nfs/nfs_nfssvc.c:90
#23 0x807b4e35 in syscall (frame=0xfcc95d38)
    at /usr/src/sys/i386/i386/trap.c:1073
#24 0x8079cf50 in Xint0x80_syscall ()
    at /usr/src/sys/i386/i386/exception.s:261
#25 0x00000033 in ?? ()
Previous frame inner to this frame (corrupt stack?)

Any ideas on this one?
-- 
Michael Moll