LOR on umount on -BETA1

LOR on -CURRENT and -BETA1.

plug pen-drive:

Jul  7 01:45:42 gargoyle root: Unknown USB device: vendor 0x08ec product
0x0008 bus uhub3
Jul  7 01:45:42 gargoyle kernel: ugen6.2: <Kingston> at usbus6
Jul  7 01:45:42 gargoyle kernel: umass0: <Kingston DataTraveler 2.0, class
0/0, rev 2.00/1.00, addr 2> on usbus6
Jul  7 01:45:42 gargoyle kernel: umass0:  SCSI over Bulk-Only; quirks =
0x0000
Jul  7 01:45:43 gargoyle kernel: umass0:1:0:-1: Attached to scbus1
Jul  7 01:45:43 gargoyle kernel: (probe0:umass-sim0:0:0:0): Down reving
Protocol Version from 2 to 0?
Jul  7 01:45:45 gargoyle kernel: (probe0:umass-sim0:0:0:0): TEST UNIT READY.
CDB: 0 0 0 0 0 0
Jul  7 01:45:45 gargoyle kernel: (probe0:umass-sim0:0:0:0): CAM Status: SCSI
Status Error
Jul  7 01:45:45 gargoyle kernel: (probe0:umass-sim0:0:0:0): SCSI Status:
Check Condition
Jul  7 01:45:45 gargoyle kernel: (probe0:umass-sim0:0:0:0): UNIT ATTENTION
asc:28,0
Jul  7 01:45:45 gargoyle kernel: (probe0:umass-sim0:0:0:0): Not ready to
ready change, medium may have changed
Jul  7 01:45:45 gargoyle kernel: (probe0:umass-sim0:0:0:0):
(probe0:umass-sim0:0:0:0): TEST UNIT READY. CDB: 0 0 0 0 0 0
Jul  7 01:45:45 gargoyle kernel: (probe0:umass-sim0:0:0:0): UNIT ATTENTION
asc:28,0
Jul  7 01:45:45 gargoyle kernel: (probe0:umass-sim0:0:0:0): Not ready to
ready change, medium may have changed
Jul  7 01:45:45 gargoyle kernel: Retrying Command (per Sense Data)
Jul  7 01:45:45 gargoyle kernel: (probe0:umass-sim0:0:0:0): Retrying Command
Jul  7 01:45:45 gargoyle kernel: pass0 at umass-sim0 bus 0 target 0 lun 0
Jul  7 01:45:45 gargoyle kernel: pass0: <Kingston DataTraveler 2.0 1.04>
Removable Direct Access SCSI-0 device
Jul  7 01:45:45 gargoyle kernel: pass0: 40.000MB/s transfers
Jul  7 01:45:45 gargoyle kernel: da0 at umass-sim0 bus 0 target 0 lun 0
Jul  7 01:45:45 gargoyle kernel: da0: <Kingston DataTraveler 2.0 1.04>
Removable Direct Access SCSI-0 device
Jul  7 01:45:45 gargoyle kernel: da0: 40.000MB/s transfers
Jul  7 01:45:45 gargoyle kernel: da0: 490MB (1003520 512 byte sectors: 64H
32S/T 490C)
Jul  7 01:45:45 gargoyle kernel: GEOM: new disk da0
Jul  7 01:45:46 gargoyle kernel: GEOM: da0: partition 1 does not start on a
track boundary.
Jul  7 01:45:46 gargoyle kernel: GEOM: da0: partition 1 does not end on a
track boundary.

# mount_msdosfs /dev/da0s1 pen/, write and then # umount pen/:


Jul  7 01:56:45 gargoyle kernel: lock order reversal:
Jul  7 01:56:45 gargoyle kernel: 1st 0xc4e63bdc ufs (ufs) _at_
/usr/src/sys/kern/vfs_mount.c:1199
Jul  7 01:56:45 gargoyle kernel: 2nd 0xc4e63ce8 devfs (devfs) _at_
/usr/src/sys/fs/msdosfs/msdosfs_vfsops.c:944
Jul  7 01:56:45 gargoyle kernel: KDB: stack backtrace:
Jul  7 01:56:45 gargoyle kernel:
db_trace_self_wrapper(c0c5b564,e6da0a48,c08b5b35,c08a68db,c0c5e3f9,...) at
db_trace_self_wrapper+0x26
Jul  7 01:56:45 gargoyle kernel:
kdb_backtrace(c08a68db,c0c5e3f9,c4530430,c4530360,e6da0aa4,...) at
kdb_backtrace+0x29
Jul  7 01:56:45 gargoyle kernel:
_witness_debugger(c0c5e3f9,c4e63ce8,c0c4d3c5,c4530360,c0c4dba9,...) at
_witness_debugger+0x25
Jul  7 01:56:45 gargoyle kernel:
witness_checkorder(c4e63ce8,9,c0c4dba9,3b0,c4e63d04,...) at
witness_checkorder+0x839
Jul  7 01:56:45 gargoyle kernel:
__lockmgr_args(c4e63ce8,80400,c4e63d04,0,0,...) at __lockmgr_args+0x7a7
Jul  7 01:56:45 gargoyle kernel:
vop_stdlock(e6da0bac,c0ee9a48,c4afc9a4,80400,c4e63c90,...) at
vop_stdlock+0x62
Jul  7 01:56:45 gargoyle kernel:
VOP_LOCK1_APV(c0d38d00,e6da0bac,e6da0bcc,c0d75c00,c4e63c90,...) at
VOP_LOCK1_APV+0xb5
Jul  7 01:56:45 gargoyle kernel:
_vn_lock(c4e63c90,80400,c0c4dba9,3b0,c4add284,...) at _vn_lock+0x5e
Jul  7 01:56:45 gargoyle kernel:
msdosfs_sync(c4add284,1,c0c64e9d,4f4,80,...) at msdosfs_sync+0x29c
Jul  7 01:56:45 gargoyle kernel:
dounmount(c4add284,8000000,c4afc900,479,2,...) at dounmount+0x44e
Jul  7 01:56:45 gargoyle kernel:
unmount(c4afc900,e6da0cf8,8,c4afc900,c0d3c288,...) at unmount+0x30f
Jul  7 01:56:45 gargoyle kernel: syscall(e6da0d38) at syscall+0x2a3
Jul  7 01:56:45 gargoyle kernel: Xint0x80_syscall() at Xint0x80_syscall+0x20
Jul  7 01:56:45 gargoyle kernel: --- syscall (22, FreeBSD ELF32, unmount),
eip = 0x280d91ff, esp = 0xbfbfe52c, ebp = 0xbfbfe5f8 ---


bervose boot: http://pastebin.com/f604c1399

some more info can be found at
http://forums.freebsd.org/showthread.php?t=5025

Willing to try patches or solutions at your request.

Best Regards.
Gonzalo