Using read-only NULLFS leads to panic. gdb output included, easy to reproduce.

[Tim Robbins]

On Tue, Mar 02, 2004 at 10:39:36PM +0100, Pawe Maachowski wrote:
>
> I know NULLFS is documented as broken and incoming PRs are usually put
> in suspended state, awaiting a patch.
> However, there are people claiming that using NULLFS in read-only mode
> is safe. It seems, they are wrong.  [...]
> Environmnet:
> (A) FreeBSD 4.9-RELEASE, null.ko.
> (B) FreeBSD 4.9-STABLE, NULLFS, almost GENERIC (+IPFIREWALL, IPFILTER...)
> (C) FreeBSD 4.8-RELEASE, GENERIC, nullfs.ko (+ipfw.ko)  [...]

There are known bugs in nullfs in all 4.x releases to date, and in 5.0.
If I have time, I may MFC the fixes some time before 4.10 is released.
Can you reproduce these problems on 5.1 or 5.2?


Tim