kern/52056: mount -u / causes a kernel assertion

[martin%NetBSD.org@localhost]

>Number:         52056
>Category:       kern
>Synopsis:       mount -u / causes a kernel assertion
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Mar 09 19:00:01 +0000 2017
>Originator:     Martin Husemann
>Release:        NetBSD 7.99.65
>Organization:
The NetBSD Foundation, Inc.
>Environment:
System: NetBSD drowsy.duskware.de 7.99.65 NetBSD 7.99.65 (DROWSY) #3: Tue Mar 7 09:35:27 CET 2017 martin%martins.aprisoft.de@localhost:/ssd/src/sys/arch/shark/compile/DROWSY shark
Architecture: earmv4
Machine: shark
>Description:

After a fsck in single user mode I rebooted with boot -s,
then at the single user prompt:

mount -u /

and edited /etc/rc.conf. After exiting the single user shell (w/o another
reboot):

Starting syslogd.
Setting date via ntp.
Starting rpcbind.
Mounting all file systems...
Clearing temporary files.
panic: kernel diagnostic assertion "!(bp->b_oflags & BO_DELWRI)" failed: file "../../../../kern/vfs_wapbl.c", line 1142 
Stopped in pid 0.38 (system) at netbsd:cpu_Debugger+0x4:        mov     pc, r14

db> bt
0xf60a4e2c: netbsd:vpanic+0xc
0xf60a4e44: netbsd:kern_assert+0x40
0xf60a4e7c: netbsd:wapbl_add_buf+0x108
0xf60a4e9c: netbsd:bdwrite+0xc0
0xf60a4f04: netbsd:ffs_update.part.3+0x284
0xf60a4f5c: netbsd:ffs_sync+0x128
0xf60a4fac: netbsd:sched_sync+0x278


>How-To-Repeat:
s/a

>Fix:
n/a