unmount cgd panic

[Patrick Welche <prlw1%cam.ac.uk@localhost>]

Everytime I shutdown a NetBSD-current/i386 system with a cgd partition,
I get the following panic - anyone recognise a "recent" change (say last
3 weeks) that may cause this?

Cheers,

Patrick

#0  cpu_reboot (howto=260, bootstr=0x0)
    at ../../../../arch/i386/i386/machdep.c:861
861             splx(s);
(gdb) bt
#0  cpu_reboot (howto=260, bootstr=0x0)
    at ../../../../arch/i386/i386/machdep.c:861
#1  0xc0449954 in panic (fmt=0xc0654d90 "trap")
    at ../../../../kern/subr_prf.c:299
#2  0xc047fc3b in trap (frame=0xe026b320)
    at ../../../../arch/i386/i386/trap.c:373
#3  0xc010cb0f in calltrap ()
#4  0xc01bd141 in db_read_bytes (addr=6, size=4, data=0xe026b388 "")
    at ../../../../arch/i386/i386/db_memrw.c:91
#5  0xc01b83f5 in db_get_value (addr=6, size=4, is_signed=false)
    at ../../../../ddb/db_access.c:72
#6  0xc01bf71d in db_stack_trace_print (addr=-534333296, have_addr=true, 
    count=65535, modif=0xc0620d38 "", pr=0xc0448d10 <printf>)
    at ../../../../arch/i386/i386/db_trace.c:501
#7  0xc0449919 in panic (fmt=0xc0654d90 "trap")
    at ../../../../kern/subr_prf.c:287
#8  0xc047fc3b in trap (frame=0xe026b934)
    at ../../../../arch/i386/i386/trap.c:373
#9  0xc010cb0f in calltrap ()
#10 0xc0301b03 in turnstile_block (ts=0x0, q=1, obj=0xcbdadf64, 
    sobj=0xc067b1c8) at ../../../../kern/kern_turnstile.c:298
#11 0xc02e6399 in mutex_vector_enter (mtx=0xcbdadf64)
    at ../../../../kern/kern_mutex.c:687
#12 0xc01cbda7 in dk_close (di=0xc0675114, dksc=0xcbdadf04, dev=5376, flags=3, 
    fmt=24576, l=0xe023d7c0) at ../../../../dev/dksubr.c:159
#13 0xc01a34a1 in cgdclose (dev=5376, flags=3, fmt=24576, l=0xe023d7c0)
    at ../../../../dev/cgd.c:274
#14 0xc043e07b in bdev_close (dev=5376, flag=3, devtype=24576, l=0xe023d7c0)
    at ../../../../kern/subr_devsw.c:724
#15 0xc0431b0f in spec_close (v=0xe026bb48)
    at ../../../../miscfs/specfs/spec_vnops.c:1071
#16 0xc0519b6c in VOP_CLOSE (vp=0xcbe3be64, fflag=3, cred=0xffffffff)
    at ../../../../kern/vnode_if.c:274
#17 0xc022a9b5 in ffs_unmount (mp=0xcc0a4000, mntflags=524288)
    at ../../../../ufs/ffs/ffs_vfsops.c:1421
#18 0xc0502a86 in VFS_UNMOUNT (mp=0xcc0a4000, a=524288)
    at ../../../../kern/vfs_subr.c:3053
#19 0xc050adcc in dounmount (mp=0xcc0a4000, flags=524288, l=0xe023d7c0)
    at ../../../../kern/vfs_syscalls.c:750
#20 0xc0503cb4 in vfs_unmount_forceone (l=0xe023d7c0)
    at ../../../../kern/vfs_subr.c:2329
#21 0xc032768d in cpu_reboot (howto=2056, bootstr=0x0)
    at ../../../../arch/i386/i386/machdep.c:904
#22 0xc0302919 in sys_reboot (l=0xe023d7c0, uap=0xe026bd00, retval=0xe026bd28)
    at ../../../../kern/kern_xxx.c:78
#23 0xc045bb44 in syscall (frame=0xe026bd48) at ../../../../sys/syscallvar.h:61
#24 0xc0100504 in syscall1 ()

In frame 12
(gdb) print *dk
$6 = {dk_link = {tqe_next = 0x0, tqe_prev = 0x0}, dk_name = 0xcbdadf20 "cgd0", 
  dk_info = 0x0, dk_bopenmask = 1, dk_copenmask = 0, dk_openmask = 1, 
  dk_state = 0, dk_blkshift = 0, dk_byteshift = 9, dk_stats = 0xcbd522a0, 
  dk_driver = 0xc067510c, dk_rawlock = {u = {mtxa_owner = 4294967280}}, 
  dk_rawopens = 0, dk_rawvp = 0x0, dk_openlock = {u = {
      mtxa_owner = 4294967282}}, dk_nwedges = 0, dk_wedges = {lh_first = 0x0}, 
  dk_labelsector = 1, dk_label = 0xcbe46a00, dk_cpulabel = 0xcbe46800}

(single processor)