Remounting a drive as read/write crashes the system and no dmesg.boot

[Mel Flynn]

On Saturday 22 August 2009 02:40:53 Scott Schappell wrote:
> On Aug 21, 2009, at 17:32:13, Mel Flynn wrote:
> > On Friday 21 August 2009 07:34:11 Scott Schappell wrote:
> >> Looking at info.0 I see:
> >>
> >>
> >> Dump header from device /dev/ad0s1b
> >>   Architecture: i386
> >>   Architecture Version: 2
> >>   Dump Length: 155131904B (147 MB)
> >>   Blocksize: 512
> >>   Dumptime: Fri Aug 21 08:27:45 2009
> >>   Hostname: arthur.silvertree.org
> >>   Magic: FreeBSD Kernel Dump
> >>   Version String: FreeBSD 7.2-RELEASE-p3 #1: Fri Aug 14 13:27:47 PDT
> >> 2009
> >>     root at arthur.silvertree.org:/usr/obj/usr/src/sys/ARTHUR
> >>   Panic String: ffs_sync: rofs mod
> >>   Dump Parity: 2778312054
> >>   Bounds: 0
> >>   Dump Status: good
> >>
> >> This is interesting:
> >>
> >> "Panic String: ffs_sync: rofs mod"
> >>
> >> It looks I'm guessing this is saying "read only file system
> >> modified".  So it looks like the problem is with mount?
> >>
> >> If there's anything you want me to pull from the vmcore.0 let me
> >> know.
> >>
> >> Again, this happens with the drive mounted RO from fstab. Unmounted
> >> then mount -o rw /backup.
> >>
> >> Something is amiss, and first blush doesn't seem to be hardware
> >> related.
> >
> > There should be a backtrace in info.0 already. That part contains more
> > relevant information.
> 
> Nope, that's all info.0 contains.

Follow up. Temp fix available here:
http://www.freebsd.org/cgi/getmsg.cgi?fetch=193338+0+current/freebsd-current
-- 
Mel