keep getting kernel panic

[Roberto Lima]

Hi all, I have problems with FreeBSD 6.0-RELEASE in my web server.
This crashs in all time.. The kgdb shows it:

(kgdb) bt
#0  doadump () at pcpu.h:165
#1  0xc04cf900 in boot (howto=260) at ../../../kern/kern_shutdown.c:399
#2  0xc04cfbe2 in panic (fmt=0xc0618b65 "BUF_UNLOCK %p while B_REMFREE
is still set.") at ../../../kern/kern_shutdown.c:555
#3  0xc05147a5 in vfs_bio_clcheck (vp=0xc519239c, size=0, lblkno=7,
blkno=Unhandled dwarf expression opcode 0x93
) at buf.h:312
#4  0xc0514912 in vfs_bio_awrite (bp=0xd8dc8fcc) at ../../../kern/vfs_bio.c:1583
#5  0xc058fd89 in ffs_syncvnode (vp=0xc519239c, waitfor=2) at
../../../ufs/ffs/ffs_vnops.c:277
#6  0xc058eafd in ffs_sync (mp=0xc4e3a400, waitfor=2, td=0xc5a4a300)
at ../../../ufs/ffs/ffs_vfsops.c:1114
#7  0xc0525706 in sync (td=0xc5a4a300, uap=0x0) at
../../../kern/vfs_syscalls.c:136
#8  0xc04cf546 in boot (howto=256) at pcpu.h:162
#9  0xc04cfbe2 in panic (fmt=0xc0607b72 "%s") at
../../../kern/kern_shutdown.c:555
#10 0xc05e5af0 in trap_fatal (frame=0xf31006ec, eva=152) at
../../../i386/i386/trap.c:831
#11 0xc05e5833 in trap_pfault (frame=0xf31006ec, usermode=0, eva=152)
at ../../../i386/i386/trap.c:742
#12 0xc05e54e5 in trap (frame=
      {tf_fs = 8, tf_es = 40, tf_ds = 40, tf_edi = -1067340392, tf_esi
= 799, tf_ebp = -217053384, tf_isp = -217053416, tf_ebx = 152, tf_edx
= -979066112, tf_ecx = 0, tf_eax = -979066112, tf_trapno = 12, tf_err
= 0, tf_eip = -1068729592, tf_cs = 32, tf_eflags = 66182, tf_esp =
4098, tf_ss = 0}) at ../../../i386/i386/trap.c:432
#13 0xc05d3dda in calltrap () at ../../../i386/i386/exception.s:139
#14 0xc04c7b08 in _mtx_lock_flags (m=0x98, opts=0, file=0xc061ad98
"../../../kern/vfs_vnops.c", line=799)
    at ../../../kern/kern_mutex.c:268
#15 0xc052e4cf in debug_vn_lock (vp=0x0, flags=4098, td=0xc5a4a300,
filename=0xc060aaec "../../../fs/procfs/procfs.c",
    line=73) at ../../../kern/vfs_vnops.c:799
#16 0xc0494530 in procfs_doprocfile (td=0xc5a4a300, p=0xc5496624,
pn=0xc4c66d00, sb=0xf31007d8, uio=0x0)
    at ../../../fs/procfs/procfs.c:73
#17 0xc0497d0c in pfs_readlink (va=0xc5a4a300) at pcpu.h:162
#18 0xc05f6403 in VOP_READLINK_APV (vop=0xc063ca20, a=0xf3100c30) at
vnode_if.c:1481
#19 0xc05291ff in kern_readlink (td=0xc5a4a300, path=0xc5a4a300
"<jÞÅ`\f\225Å", pathseg=3315901184,
    buf=0xc5a4a300 "<jÞÅ`\f\225Å", bufseg=3315901184, count=1024) at
vnode_if.h:772
#20 0xc052911e in readlink (td=0xc5a4a300, uap=0xc5a4a300) at
../../../kern/vfs_syscalls.c:2261
#21 0xc05e5dd3 in syscall (frame=
      {tf_fs = 59, tf_es = 59, tf_ds = 59, tf_edi = 135507064, tf_esi
= 135655436, tf_ebp = -1077940936, tf_isp = -217051804, tf_ebx =
674293876, tf_edx = -1077941960, tf_ecx = 0, tf_eax = 58, tf_trapno =
22, tf_err = 2, tf_eip = 672584499, tf_cs = 51, tf_eflags = 647,
tf_esp = -1077942020, tf_ss = 59}) at ../../../i386/i386/trap.c:976
#22 0xc05d3e2f in Xint0x80_syscall () at ../../../i386/i386/exception.s:200
#23 0x00000033 in ?? ()
Previous frame inner to this frame (corrupt stack?)
(kgdb)


How can i fix this? Any patch or only updating to 6.1?

Thanks in advance.
Roberto Lima