RELENG_5 panic - NFS

db> tr
Tracing pid 56 tid 100064 td 0xc273b640
turnstile_wait(c2988400,c3011230,c6697960,c2988400,0) at
turnstile_wait+0x269
_mtx_lock_sleep(c3011230,c273b640,0,0,0) at _mtx_lock_sleep+0x81
fork1(c06f2e00,60034,0,e5204ac4,c2b0c870) at fork1+0x69c
kthread_create(c05aa030,c06fdff4,0,40000,0) at kthread_create+0x41
nfs_nfsiodnew(c00,0,c167b460,13f000,0) at nfs_nfsiodnew+0x8d
nfs_asyncio(d68fb3cc,0,0,0,d68fb3cc) at nfs_asyncio+0x69
nfs_strategy(e5204b6c,1,c273b640,e5204b9c,c04ef9e7) at
nfs_strategy+0x52
nfs_writebp(d68fb3cc,1,c273b640,e5204c74,c05b1bc0) at
nfs_writebp+0x138
nfs_bwrite(d68fb3cc,80012,0,c273b640,c273b640) at nfs_bwrite+0x23
nfs_flush(3,c273b640,1) at nfs_flush+0x463
nfs_fsync(e5204cd4,30002,c273b640,0,0) at nfs_fsync+0x2a
sched_sync(0,e5204d48,e5204d48,c0e85d67,31f) at sched_sync+0x52a
fork_exit(c055f74b,0,e5204d48) at fork_exit+0x64
fork_trampoline() at fork_trampoline+0x8
--- trap 0x1, eip = 0, esp = 0xe5204d7c, ebp = 0 ---
db>
db> show lockedvnods
Locked vnodes
0xc66ad000: tag nfs, type VREG, usecount 1, writecount 1, refcount 32, flags (VV
_OBJBUF), lock type nfs: EXCL (count 1) by thread 0xc273b640 (pid 56)
        fileid 189710 fsid 0x200ff09
db>
db> show pcpu
cpuid        = 0
curthread    = 0xc273b640: pid 56 "syncer"
curpcb       = 0xe5204da0
fpcurthread  = none
idlethread   = 0xc26644b0: pid 11 "idle"
APIC ID      = 0
currentldt   = 0x28
db>
Dumping 1024 MB
 16 32 48 64 80 96 112 128 144 160 176 192 208 224 240 256 272 288 304 320 336 3
52 368 384 400 416 432 448 464 480 496 512 528 544 560 576 592 608 624 640 656 6
72 688 704 720 736 752 768 784 800 816 832 848 864 880 896 912 928 944 960 976 9
92 1008
Dump complete
0xf
db>

I have a kernel.debug and vmcore if anyone wants more info.

 -aW