[PANIC] ffs_alloccg: map corrupted

Thoughts?

FreeBSD 9.0-CURRENT #654 r215604M: Sat Nov 20 19:51:27 PST 2010
    rootk_at_dragon:/sys/i386/compile/DRAGON i386
[..]
start = 0, len = 3359, fs = /files
panic: ffs_alloccg: map corrupted
cpuid = 1
KDB: stack backtrace:
db_trace_self_wrapper(c0839222,a0d7365,0,c08affe0,7,...) at 0xc04e9ab6 = db_trace_self_wrapper+0x26
kdb_backtrace(c0857e2a,1,c084c0c3,e99dd70c,1,...) at 0xc05fa2fa = kdb_backtrace+0x2a
panic(c084c0c3,0,d1f,c6bfc8d4,e1230000,...) at 0xc05cd297 = panic+0x117
ffs_mapsearch(3f03fe0,0,8,0,0,...) at 0xc0751793 = ffs_mapsearch+0x153
ffs_alloccgblk(3f03fe0,0,4000,5a5,0,...) at 0xc075198c = ffs_alloccgblk+0xec
ffs_alloccg(c98706cc,2be,3f03fe0,0,4000,...) at 0xc07522b3 = ffs_alloccg+0x1b3
ffs_hashalloc(3f03fe0,0,4000,4000,c0752100,...) at 0xc074ebb1 = ffs_hashalloc+0x41
ffs_alloc(c98706cc,e,0,3f03fe0,0,...) at 0xc075332f = ffs_alloc+0x19f
ffs_balloc_ufs2(ce55e660,38000,0,4000,ce77b300,...) at 0xc0755629 = ffs_balloc_ufs2+0x1949
ffs_write(e99ddb90,e99ddb4c,e99ddb10,c0778dc2,ce55e6b8,...) at 0xc0777f66 = ffs_write+0x276
VOP_WRITE_APV(c08b0500,e99ddb90,ce55e660,264,0,...) at 0xc07fb574 = VOP_WRITE_APV+0xe4
vn_write(cf7a9cb0,e99ddc24,ce77b300,0,cb5a2870,...) at 0xc065ec93 = vn_write+0x1c3
dofilewrite(e99ddc24,ffffffff,ffffffff,0,cf7a9cb0,...) at 0xc060a9f5 = dofilewrite+0x95
kern_writev(cb5a2870,1,e99ddc24,e99ddc44,1,...) at 0xc060ac88 = kern_writev+0x58
write(cb5a2870,e99ddcec,4,c08ecbc0,b,...) at 0xc060ad0f = write+0x4f
syscallenter(cb5a2870,e99ddce4,c05bde7d,c709d0d0,3110a33f,...) at 0xc0605d43 = syscallenter+0x2c3
syscall(e99ddd28) at 0xc07dcf94 = syscall+0x34
Xint0x80_syscall() at 0xc07c8e91 = Xint0x80_syscall+0x21
--- syscall (4, FreeBSD ELF32, write), eip = 0x281e260b, esp = 0xbfbfc19c, ebp = 0xbfbfc1b8 ---
panic: bufwrite: buffer is not busy???
cpuid = 1

-- 
-- David  (obrien_at_FreeBSD.org)