panic: ufs_dirbad: bad dir

[Rumko <rumcic@xxxxxxxxx>]

After a previous panic I got this panic while building world. After cleaning
out /usr/obj I have been unable to repeat this panic again, so it's not
reproducable (for now).

Dump at leaf:~rumko/crash/bad_dir/ and the backtrace is:
#0  dumpsys () at ./machine/thread.h:83
#1  0xc01e6d95 in boot (howto=260) at /usr/src/sys/kern/kern_shutdown.c:375
#2  0xc01e705a in panic (fmt=0xc0447c39 "ufs_dirbad: bad dir")
at /usr/src/sys/kern/kern_shutdown.c:802
#3  0xc0323b53 in ufs_dirbad (ip=0xf57c9e00, offset=0, how=0xc0447c90 "mangled
entry") at /usr/src/sys/vfs/ufs/ufs_lookup.c:610
#4  0xc0324463 in ufs_lookup (ap=0xf5dccabc)
at /usr/src/sys/vfs/ufs/ufs_lookup.c:275
#5  0xc0325faa in ufs_vnoperate (ap=0xf5dccabc)
at /usr/src/sys/vfs/ufs/ufs_vnops.c:2303
#6  0xc0240948 in vop_old_lookup (ops=0xd554ca50, dvp=0xf5815ee8,
vpp=0xf5dccb24, cnp=0xf5dccb04) at /usr/src/sys/kern/vfs_vopops.c:172
#7  0xc022f252 in vop_compat_nresolve (ap=0xf5dccb58)
at /usr/src/sys/kern/vfs_default.c:225
#8  0xc022ec59 in vop_defaultop (ap=0xf5dccb58)
at /usr/src/sys/kern/vfs_default.c:153
#9  0xc0325faa in ufs_vnoperate (ap=0xf5dccb58)
at /usr/src/sys/vfs/ufs/ufs_vnops.c:2303
#10 0xc0241092 in vop_nresolve (ops=0xd554ca50, nch=0xf5dccb98, dvp=0xf5815ee8,
cred=0xc5be6b98) at /usr/src/sys/kern/vfs_vopops.c:951
#11 0xc022b87f in cache_resolve (nch=0xf5dccbd4, cred=0xc5be6b98)
at /usr/src/sys/kern/vfs_cache.c:2135
#12 0xc0233f4d in nlookup (nd=0xf5dccc80)
at /usr/src/sys/kern/vfs_nlookup.c:499
#13 0xc023c576 in kern_stat (nd=0xf5dccc80, st=0xf5dccc18)
at /usr/src/sys/kern/vfs_syscalls.c:2444
#14 0xc023c714 in sys_stat (uap=0xf5dcccf0)
at /usr/src/sys/kern/vfs_syscalls.c:2485
#15 0xc03fa8e9 in syscall2 (frame=0xf5dccd40)
at /usr/src/sys/platform/pc32/i386/trap.c:1339
#16 0xc03e7be6 in Xint0x80_syscall ()
at /usr/src/sys/platform/pc32/i386/exception.s:876
#17 0x08063527 in ?? ()
Backtrace stopped: previous frame inner to this frame (corrupt stack?)
-- 
Regards,
Rumko