>src/sys/miscfs/union/union_vnops.c
>    (marc - Tue Mar 17 00:36:58 PST 1998)
>    mounting a union causes VOP_WHITEOUT to be called on the upper root
>    vn, with a 0 component.  If the upper fs was a unionfs,
>    union_whiteout() would deref compnent to get a struct proc, and panic.
>    struct proc was only being passed to FIXUP, which never used it.  It
>    turns out this happened a lot.  I ripped most of the unneeded code
>    out, and left in the few places that really did need the proc handle.


Wrt. the recent unionfs changes, a kernel built from today's sup says


Mar 19 01:12:38 q700 shutdown: halt by hauke:
Mar 19 01:12:41 q700 syslogd: exiting on signal 15
syncing disks... 3 3 done
unmounting /usr/src (<above>:/var/obj)...
panic: lockmgr: using decommissioned lock
Stopped at      _Debugger+0x6:  unlk    a6
db> t
_Debugger(0,541134,809d04,220d0,21f32) + 6
_panic(21f32,10002,5cac00,543380,2) + 50
_lockmgr(541134,10002,54325c,809d38,45772) + 42
_ufs_lock(809d2c) + 1c
_vn_lock(543200,10002) + 40
_vrele(543200) + 72
_union_freevp(543080,809dbc,40762,809d9c,5cac00) + 4c
_union_reclaim(809d9c) + c
_vclean(543080,8,5cac00) + 11c
_vgonel(543080,5cac00) + 3a
_vflush(5b1000,593f80,2) + 72
_union_unmount(5b1000,80000,5cac00) + 38
_dounmount(5b1000,80000,5cac00) + a8
_vfs_unmountall(0,11f,d0,0,b) + 52
_vfs_shutdown(809f44,28ff0,8,0,5cac00) + cc
_cpu_reboot(8,0,5cac00,8,809f88) + 4c
_sys_reboot(5cac00,809f88,809f80) + 56
_syscall(d0) + 13e
_trap0() + e
db> ps
 PID             PPID       PGRP        UID S   FLAGS          COMMAND    WAIT
>518                1        517        100 2  0x4006             halt
 2                  0          0          0 3   0x204       pagedaemon   paged
 1                  0          1          0 3  0x4084             init    wait
 0                 -1          0          0 2   0x204          swapper
db>


??? Never saw that one before. Not quite fixed...

	hauke


--
"It's never straight up and down"     (DEVO)