panic: mutex nfsd_mtx not owned at nfs_srvsock.c:148

While stress testing GENERIC HEAD from Aug 12 12:55 UTC I got this
panic:

panic: mutex nfsd_mtx not owned at
../../../nfsserver/nfs_srvsock.c:148
cpuid = 2
KDB: enter: panic
[thread pid 761 tid 100096 ]
Stopped at      kdb_enter+0x2b: nop
db> where
Tracing pid 761 tid 100096 td 0xc4041a20
kdb_enter(c091cda8) at kdb_enter+0x2b
panic(c091c0b7,c09210c9,c093241d,94,0,...) at panic+0x14b
_mtx_assert(c0a64ec0,1,c093241d,94,c07ec53c,...) at _mtx_assert+0x66
nfs_rephead(0,c52a0600,48,e662e964,e662e968,...) at nfs_rephead+0x25
nfsrv_symlink(c52a0600,c4071e00,c4041a20,e662ec40) at
nfsrv_symlink+0x3b7
nfssvc_nfsd(c4041a20) at nfssvc_nfsd+0x409
nfssvc(c4041a20,e662ed04) at nfssvc+0x18c
syscall(3b,3b,3b,1,0,...) at syscall+0x256

More details _at_ http://people.freebsd.org/~pho/stress/log/cons204.html
-- 
Peter Holm