panic: ufs_dirbad: /: bad dir ino 160292 at offset 512: mangled entry

Just got this on a VM disk image.
I couldn't dump as I needed the crashdump which was waiting for me already (means the system had previously paniced).
A full fsck w/o journal seems to have fixed it on the next round.

Just posting in case this is seen more often so people can find it.

Lots of health (or more than that fs that moment) to all of you,
/bz


2021-11-04T22:59:47.564904+00:00 - init 1 - - /bin/sh on /etc/rc terminated abnormally, going to single user mode
Enter full pathname of shell or RETURN for /bin/sh:
root@:/ # fsck /
** /dev/ada0p4
** SU+J Recovering /dev/ada0p4

USE JOURNAL? [yn] y

** Reading 33554432 byte journal from inode 4.

RECOVER? [yn] y

** Building recovery table.
** Resolving unreferenced inode list.
** Processing journal entries.

WRITE CHANGES? [yn] y


***** FILE SYSTEM IS CLEAN *****
** 13 journal records in 2048 bytes for 20.31% utilization
** Freed 2 inodes (0 dirs) 1 blocks, and 3 frags.

***** FILE SYSTEM MARKED CLEAN *****
root@:/ # ^D
Setting hostuuid: e0738d77-da8d-11eb-8339-000db9559b74.
Setting hostid: 0x789c8996.
Fast boot: skipping disk checks.
panic: ufs_dirbad: /: bad dir ino 160292 at offset 512: mangled entry
cpuid = 0
time = 1636066794
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe0051f1e6a0
vpanic() at vpanic+0x187/frame 0xfffffe0051f1e700
panic() at panic+0x43/frame 0xfffffe0051f1e760
ufs_lookup_ino() at ufs_lookup_ino+0xd9a/frame 0xfffffe0051f1e860
vfs_cache_lookup() at vfs_cache_lookup+0xa6/frame 0xfffffe0051f1e8b0
cache_fplookup_final_modifying() at cache_fplookup_final_modifying+0x2f4/frame 0xfffffe0051f1e930
cache_fplookup_noentry() at cache_fplookup_noentry+0xb2/frame 0xfffffe0051f1e9a0
cache_fplookup() at cache_fplookup+0x5f5/frame 0xfffffe0051f1ea90
namei() at namei+0x1e6/frame 0xfffffe0051f1eb50
vn_open_cred() at vn_open_cred+0x12c/frame 0xfffffe0051f1ecb0
kern_openat() at kern_openat+0x285/frame 0xfffffe0051f1ee00
amd64_syscall() at amd64_syscall+0x12e/frame 0xfffffe0051f1ef30
fast_syscall_common() at fast_syscall_common+0xf8/frame 0xfffffe0051f1ef30
--- syscall (499, FreeBSD ELF64, sys_openat), rip = 0x8011e3c2a, rsp = 0x7fffffffe248, rbp = 0x7fffffffe330 ---
KDB: enter: panic
[ thread pid 89 tid 100099 ]
Stopped at      kdb_enter+0x37: movq    $0,0x127094e(%rip)


-- 
Bjoern A. Zeeb                                                     r15:7