[PANIC] VOP_STRATEGY failed

FreeBSD 7.0-CURRENT #196: Wed Oct 26 23:19:58 PDT 2005 amd64

GNU gdb 6.1.1 [FreeBSD]

Unread portion of the kernel message buffer:
panic: VOP_STRATEGY failed bp=0xffffffff9a12f1c8 vp=0xffffff012fa6d5d0
cpuid = 3
KDB: stack backtrace:
panic() at panic+0x253
bufstrategy() at bufstrategy+0x6d
nfs_writebp() at nfs_writebp+0xf0
nfs_write() at nfs_write+0x698
VOP_WRITE_APV() at VOP_WRITE_APV+0xa4
vn_write() at vn_write+0x1c3
dofilewrite() at dofilewrite+0x87
kern_writev() at kern_writev+0x51
write() at write+0x4a
syscall() at syscall+0x4e7
Xfast_syscall() at Xfast_syscall+0xa8
--- syscall (4, FreeBSD ELF64, write), rip = 0x47a43c, rsp = 0x7fffffffe338, rbp = 0x680 ---
Uptime: 1h32m49s

(kgdb) where
#0  doadump () at pcpu.h:172
#1  0xffffffff803c6c6c in boot (howto=260) at ../../../kern/kern_shutdown.c:399
#2  0xffffffff803c670b in panic (
    fmt=0xffffffff80647608 "VOP_STRATEGY failed bp=%p vp=%p")
    at ../../../kern/kern_shutdown.c:555
#3  0xffffffff8041ebad in bufstrategy (bo=0x0, bp=0xffffffff9a12f1c8)
    at ../../../kern/vfs_bio.c:3690
#4  0xffffffff804cd240 in nfs_writebp (bp=0xffffffff9a12f1c8, force=0, td=0x0)
    at buf.h:415
#5  0xffffffff804be458 in nfs_write (ap=0x0) at buf.h:401
#6  0xffffffff805de9e4 in VOP_WRITE_APV (vop=0xffffffff807e58a0, 
    a=0xffffffffb83a49e0) at vnode_if.c:698
#7  0xffffffff804390b3 in vn_write (fp=0xffffff00a9aea5a0, 
    uio=0xffffffffb83a4b20, active_cred=0x0, flags=0, td=0xffffff009fbd3500)
    at vnode_if.h:372
#8  0xffffffff803f1487 in dofilewrite (td=0xffffff009fbd3500, fd=3, 
    fp=0xffffff00a9aea5a0, auio=0xffffffffb83a4b20, offset=0, flags=0)
    at file.h:246
#9  0xffffffff803f1751 in kern_writev (td=0xffffff009fbd3500, fd=3, 
    auio=0xffffffffb83a4b20) at ../../../kern/sys_generic.c:402
#10 0xffffffff803f184a in write (td=0x0, uap=0x0)
    at ../../../kern/sys_generic.c:326
#11 0xffffffff8058d6d7 in syscall (frame=
      {tf_rdi = 3, tf_rsi = 6615040, tf_rdx = 1664, tf_rcx = 7, tf_r8 = 32752, tf_r9 = 140737488347528, tf_rax = 4, tf_rbx = 6039296, tf_rbp = 1664, tf_r10 = -1096800402576, tf_r11 = 6041920, tf_r12 = 6615040, tf_r13 = 0, tf_r14 = 0, tf_r15 = 0, tf_trapno = 12, tf_addr = 6615040, tf_flags = 139, tf_err = 2, tf_rip = 4695100, tf_cs = 43, tf_rflags = 514, tf_rsp = 140737488347960, tf_ss = 35})
    at ../../../amd64/amd64/trap.c:814
#12 0xffffffff8057a518 in Xfast_syscall ()
    at ../../../amd64/amd64/exception.S:270
#13 0x000000000047a43c in ?? ()
Previous frame inner to this frame (corrupt stack?)