recursed on non-recursive lock (sleep mutex) vm page queue mutex

I don't think I've seen this one before (i386, kernel built Sep 17).
Is it already fixed?

Kris

recursed on non-recursive lock (sleep mutex) vm page queue mutex _at_ /a/asami/portbuild/i386/src-client/sys/kern/vfs_bio.c:3630
first acquired _at_ /a/asami/portbuild/i386/src-client/sys/vm/vm_pageout.c:403
panic: recurse
Debugger("panic")
Stopped at      Debugger+0x54:  xchgl   %ebx,in_Debugger.0
db> trace
Debugger(c043582e,c04a70e0,c0438952,d7077940,100) at Debugger+0x54
panic(c0438952,c044c2d9,193,c043b873,e2e) at panic+0xd5
witness_lock(c04d5900,8,c043b873,e2e,1) at witness_lock+0x3b3
_mtx_lock_flags(c04d5900,0,c043b873,e2e,0) at _mtx_lock_flags+0xba
vm_hold_free_pages(ce50cbc0,d0807000,d0808000,a75,c4ccfb68) at vm_hold_free_pages+0x142
allocbuf(ce50cbc0,0,c043b873,74c,c449f5b4) at allocbuf+0x1b8
getnewbuf(0,0,8000,8000,200) at getnewbuf+0x3fc
getblk(c449f5b4,2878c80,0,8000,0) at getblk+0x38e
breadn(c449f5b4,2878c80,0,8000,0) at breadn+0x52
bread(c449f5b4,2878c80,0,8000,0) at bread+0x4c
ffs_update(c4631db0,0,1,54,c0af9b88) at ffs_update+0x206
ufs_inactive(d7077c30,d7077c4c,c02c1333,d7077c30,0) at ufs_inactive+0x1f5
ufs_vnoperate(d7077c30,0,c043d141,8e3,c048efa0) at ufs_vnoperate+0x18
vput(c4631db0,0,c044c2d9,3b2,c4631db0) at vput+0x143
vm_pageout_scan(0,0,c044c2d9,5d5,1f4) at vm_pageout_scan+0x67d
vm_pageout(0,d7077d48,c043313d,314,1a537318) at vm_pageout+0x2db
fork_exit(c03a5fe0,0,d7077d48) at fork_exit+0xcf
fork_trampoline() at fork_trampoline+0x8
--- trap 0x1, eip = 0, esp = 0xd7077d7c, ebp = 0 ---
db>