A few days ago I did the first reboot after an upgrade from snapshots a
couple of weeks ago. The machine panicked with the below message which
I've never seen before (transcription from image on my mobile camera)
and I had to do a warm reboot:
----8<----
login: syncing disks... panic: kernel diagnostics assertion "vp->v_uvcount ==
0" failed: file "/usr/src/sys/kern/kern_unveil.c", line 746
Stopped at db_enter+0x12: popq %r11
TID PID UID PRFLAGS PFLAGS CPU COMMAND
*489797 51004 0 0x3 0 0K reboot
db_enter() at db_enter+0x12
panic() at panic+0x120
__assert(ffffffff81256574,ffff80002374eed0,0,ffffff02cdeb50e8) at __assert+0x24
unveil_removevnode(983a7d3933c3f079) at unveil_removevnode+0xf2
dounmount_leaf(1252bfd8bac9e733,ffff800000302c40,0) at dounmount_leaf+0x69
dounmount(602b6b5dc61da66e,ffff800000203c40,ffff800000203c00) at dounmount+0xfa
vfs_unmountall() at vfs_unmountall+0xad
vfs_shutdown(0) at vfs_shutdown+0x39
boot(7f7fffff5d78) at boot+0x59
reboot(ffff80002374f0a0) at reboot+0x5a
sys_reboot(9595068f44d5290e,ffff800024b85850,ffffffff817f7323) at sys_reboot+0x
73
syscall(b0161255ac32403c) at syscall+0x32a
Xsyscall(6,37,2,37,2,16fdcac30cf6) at Xsyscall+0x128
end of kernel
end trace frame: 0x7f7fffff5df0, count: 2
https://www.openbsd.org/ddb.html describes the minimum info required in bug
--db_more--
---->8----
Now, the following is embarrasing: It turns out that I for six months
have been running with the following in my /etc/fstab without noticing:
bffb6e701554bf34.d /mnt (usually assigned to /tmp, right!)
It is simply a typo from when I manually disklabeled a fresh install of
-current on my main workstation. I didn't notice until today when / suddenly
got filled up after I tried editing a large video file.
I changed /etc/fstab and did a new reboot, upon which the above panic
happened again. Another reboot after that (with /tmp finally properly
mounted) went well however.
I'm aware this is not a proper bug report. I just thought the transcript might
be useful to some developers since it seems to involve unveil(2). Before the
introduction of unveil(2) I had no problems rebooting the system with a missing
mount of /tmp.
Regards,
Erling
