10-STABLE crash in unionfs/zfs

[Slawa Olhovchenkov]

Unread portion of the kernel message buffer:
panic: __lockmgr_args: downgrade a recursed lockmgr zfs @ /usr/src/sys/modules/unionfs/../../fs/unionfs/union_vnops.c:1906

cpuid = 0
KDB: stack backtrace:
#0 0xffffffff8042a350 at kdb_backtrace+0x60
#1 0xffffffff803f05d5 at panic+0x155
#2 0xffffffff803d5a91 at __lockmgr_args+0xe71
#3 0xffffffff8047879c at vop_stdlock+0x3c
#4 0xffffffff8065575b at VOP_LOCK1_APV+0xab
#5 0xffffffff8101dc33 at unionfs_lock+0x2e3
#6 0xffffffff8065575b at VOP_LOCK1_APV+0xab
#7 0xffffffff80496cd3 at _vn_lock+0x43
#8 0xffffffff8101c0a4 at unionfs_close+0x1b4
#9 0xffffffff80653d81 at VOP_CLOSE_APV+0xa1
#10 0xffffffff803b959f at kern_execve+0x83f
#11 0xffffffff803b8b37 at sys_execve+0x37
#12 0xffffffff805f1151 at amd64_syscall+0x351
#13 0xffffffff805d707b at Xfast_syscall+0xfb
Uptime: 2d2h18m36s
Dumping 3283 out of 16327 MB:..1%..11%..21%..31%..41%..51%..61%..71%..81%..91%

(kgdb) bt
#0  doadump (textdump=<value optimized out>) at pcpu.h:219
#1  0xffffffff803f0252 in kern_reboot (howto=260) at /usr/src/sys/kern/kern_shutdown.c:452
#2  0xffffffff803f0614 in panic (fmt=<value optimized out>) at /usr/src/sys/kern/kern_shutdown.c:759
#3  0xffffffff803d5a91 in __lockmgr_args (lk=<value optimized out>, flags=<value optimized out>, ilk=0x0, wmesg=<value optimized out>,
    pri=<value optimized out>, timo=<value optimized out>, file=<value optimized out>, line=<value optimized out>) at /usr/src/sys/kern/kern_lock.c:763
#4  0xffffffff8047879c in vop_stdlock (ap=<value optimized out>) at lockmgr.h:97
#5  0xffffffff8065575b in VOP_LOCK1_APV (vop=<value optimized out>, a=<value optimized out>) at vnode_if.c:2084
#6  0xffffffff8101dc33 in unionfs_lock (ap=0xfffffe04696b84d0) at vnode_if.h:859
#7  0xffffffff8065575b in VOP_LOCK1_APV (vop=<value optimized out>, a=<value optimized out>) at vnode_if.c:2084
#8  0xffffffff80496cd3 in _vn_lock (vp=0xfffff802311aace8, flags=<value optimized out>,
    file=0xffffffff8101f098 "/usr/src/sys/modules/unionfs/../../fs/unionfs/union_vnops.c", line=610) at vnode_if.h:859
#9  0xffffffff8101c0a4 in unionfs_close (ap=<value optimized out>) at /usr/src/sys/modules/unionfs/../../fs/unionfs/union_vnops.c:610
#10 0xffffffff80653d81 in VOP_CLOSE_APV (vop=<value optimized out>, a=<value optimized out>) at vnode_if.c:535
#11 0xffffffff803b959f in kern_execve (td=0xfffff801137bb490, args=0xfffffe04696b8958, mac_p=<value optimized out>) at vnode_if.h:225
#12 0xffffffff803b8b37 in sys_execve (td=<value optimized out>, uap=<value optimized out>) at /usr/src/sys/kern/kern_exec.c:213
#13 0xffffffff805f1151 in amd64_syscall (td=0xfffff801137bb490, traced=0) at subr_syscall.c:134
#14 0xffffffff805d707b in Xfast_syscall () at /usr/src/sys/amd64/amd64/exception.S:391
#15 0x0000000800623080 in ?? ()
Previous frame inner to this frame (corrupt stack?)
Current language:  auto; currently minimal

uname -a
FreeBSD inter.trade.spb.ru 10.0-STABLE FreeBSD 10.0-STABLE #0 r266808: Wed May 28 19:13:24 MSK 2014     root at inter.trade.spb.ru:/usr/obj/usr/src/sys/TRADE  amd64