panic: userret: Returning with 1 locks held.

[Danny Braniss]

> On Wed, Mar 30, 2005 at 11:06:11AM +0200, Danny Braniss wrote:
> > >=20
> > > --OXfL5xGRrasGEqWY
> > > Content-Type: text/plain; charset=3Dus-ascii
> > > Content-Disposition: inline
> > > Content-Transfer-Encoding: quoted-printable
> > >=20
> > > On Tue, Mar 29, 2005 at 01:09:16PM +0200, Danny Braniss wrote:
> > > > this happens at boot, current as of this morning, but can't remember
> > > > when current worked on this box, so the problem is not new,
> > > > btw, 5.4 works ok.
> > > >=3D20
> > > > the console is at
> > > > 	ftp://ftp.cs.huji.ac.il/users/danny/freebsd/console-opteron.log
> > >=20
> > > What does 'show alllocks' say?  You may need to compile in WITNESS
> > > support first.
> > >=20
> > > Kris
> >=20
> > db> show alllocks
> > db>
> 
> Ah, OK, this is a panic about lockmgr locks.  'show lockedvnods'
> instead, then for each process listed do 'tr <pid>'.  CC Jeff Roberson
> <jroberson at chesapeake.net> in the reply.  'show lockedbufs' might also
> be useful if your kernel is new enough.
> 
it seems to be the unionfs:

db> show lockedvnods
Locked vnodes

0xffffff0061bfea28: tag union, type VDIR
    usecount 3, writecount 0, refcount 3 mountedhere 0
    flags (VV_ROOT)
     lock type union: EXCL (count 1) by thread 0xffffff006209a250 (pid 104)
        vp=0xffffff0061bfea28, uppervp=0xffffff006199f410, lowervp=0xffffff003baa3a28
union: upper
0xffffff006199f410: tag ufs, type VDIR
    usecount 3, writecount 0, refcount 5 mountedhere 0
    flags (VV_ROOT)
    v_object 0xffffff007c3a52a0 ref 0 pages 0
    
        ino 2, on dev md0
union: lower
0xffffff003baa3a28: tag nfs, type VDIR
    usecount 3, writecount 0, refcount 5 mountedhere 0xffffff0031be1400
    flags ()
    v_object 0xffffff006243ce00 ref 0 pages 1
    
        fileid 47104 fsid 0x500ff01
db> tr 104
Tracing pid 104 tid 100099 td 0xffffff006209a250
kdb_enter() at kdb_enter+0x2f
panic() at panic+0x249
userret() at userret+0x131
syscall() at syscall+0x286
Xfast_syscall() at Xfast_syscall+0xa8
--- syscall (0, FreeBSD ELF64, nosys), rip = 0x8008e5218, rsp = 0x7fffffffe648, rbp = 0x7fffffffe650 ---
db> show lockedbufs
db>